JPWO2005110645A1 - Vertical casting apparatus and vertical casting method - Google Patents

Abstract

Efficiently filling the mold cavities with molten metal, effectively pressurizing the molten metal in the closed cavities, and can easily cast castings that do not cause shrinkage and do not involve gas The present invention provides a vertical casting apparatus that is easy to maintain and has low equipment costs, and a vertical casting method using the vertical casting apparatus. Lower fixed mold 1 and upper movable mold 2 capable of forming a mold cavity, closing means 13 for closing the molten metal inflow gate 10 formed in the fixed mold 1, and the inside of the closed mold cavity A vertical casting apparatus comprising a main body having a pressurizing means 20 for pressurizing the molten metal and a casting means for supplying and filling the molten metal into the mold cavity from below. A vertical casting apparatus having a gas pressure pouring pot 6 that can be loaded and unloaded and a casting method using the vertical casting apparatus.

Description

  The present invention is a vertical casting apparatus capable of casting a cast product such as an aluminum alloy from below, and filling the mold cavities with molten metal from below. The present invention relates to a vertical casting apparatus for supplying and filling and a vertical casting method using the same.

  When casting a cast product such as a light alloy product, particularly a part that requires strength, a vertical casting apparatus is used in order to prevent gas entrainment during casting of the molten metal.

  In such vertical casting apparatuses, it is already known to use low-pressure gas as means for supplying molten metal from the molten metal holding furnace to the mold cavities while preventing the mixing of oxides and gas entrainment. (See JP 58-55166 A). However, the low-pressure gas is effective for quantitatively supplying the molten metal to the mold, but simply using the low-pressure gas has a low casting speed and a low pressure. It was not possible to prevent or sufficiently respond to thin-walled products. Further, in the conventional apparatus, a large amount of molten metal is accommodated in a molten metal holding furnace fixed to the apparatus main body, and the apparatus is enlarged. Further, it is not easy to replenish the molten metal in the molten metal holding furnace fixed to the apparatus main body, and it is very difficult to clean and lubricate the inflow gate of the apparatus main body.

In addition, one of the inventors of the present invention invented a method using an immersion type electromagnetic pump as a means for supplying molten metal to a mold cavity (see Japanese Patent Application Laid-Open No. 2003-266168). In order to cope with this problem, the electromagnetic pump becomes larger and the apparatus becomes larger, making it difficult to put it to practical use.
JP 58-55166 A JP 2003-266168 A

  In casting by a vertical casting apparatus, in order to cast a high-quality casting product, particularly a thin-walled and large-sized casting product, it is necessary to fill the mold cavity with molten metal at a high speed. Also, in order to prevent the inclusion of oxides and gas entrainment that cause defective defects in castings, and to prevent shrinkage caused by solidification shrinkage, it is effective to fill the molten metal from below and use a sufficient amount of molten metal. It is necessary to replenish with pressure. At that time, in order to reduce trouble during operation, it is necessary to simplify the structure of the cavity and the structure of the entire casting apparatus. Work efficiency and ease of maintenance are also very important factors.

  An object of the present invention is to fill a mold cavity with molten metal at high speed, and effectively pressurize the molten metal in the closed cavity, thereby easily casting a cast product without generation of sink marks and without entrainment of gas. It is an object of the present invention to provide a vertical casting apparatus that has high working efficiency and is easy to maintain and has a low equipment cost, and a vertical casting method using the vertical casting apparatus.

  The present inventors have intensively studied to solve the above-mentioned problems, and by using a gas pressurized hot pot that can be attached / detached with the apparatus main body, it is possible to obtain a vertical casting apparatus that has high work efficiency and is easy to maintain and has low equipment costs. It is possible to supply the molten metal at a high speed by increasing the gas pressure of the gas pressurized hot water pan, and to find that it is possible to cast a cast product with no oxide film mixing and gas entrainment, The present invention has been completed. Furthermore, after the cast molten metal is filled in the cavity, if the molten metal in such a closed state is effectively pressurized by shortening the pressure transmission distance at a plurality of locations, there is no generation of shrinkage and the inclusion of oxide film and gas. The present inventors have found that it is possible to cast a cast product that does not involve winding, and have completed the present invention.

  That is, the present invention provides (1) a lower fixed mold and an upper movable mold capable of forming a mold cavity, a closing means for closing a molten metal inflow gate formed in the fixed mold, and a closed mold. A vertical casting apparatus comprising an apparatus main body having a pressurizing means for pressurizing molten metal in a mold cavity, and casting means for supplying and filling molten metal into the mold cavity from below, wherein the casting means is A vertical casting apparatus having a gas pressurized pouring pan that can be attached to and detached from the apparatus main body, and (2) a gas pressurized pouring pan is mounted on the apparatus main body to form a sealed structure. The vertical casting apparatus as described in (1) above, and (3) a gas pressurized pouring pan provided with cast stalk, and an upper end portion of the cast stalk is brought into close contact with the apparatus main body to form a sealed structure (1) or (2) characterized in that (4) The above-described (1) or (4), wherein the apparatus main body includes a casting stalk, and the upper end portion of the gas pressurized pouring pan is brought into close contact with the apparatus main body. (1) to (4), wherein the vertical casting apparatus according to (2) and (5) the capacity of the gas pressurized pouring pan is a capacity capable of accommodating the molten metal required for one casting. The vertical casting apparatus according to any one of (1) to (5), wherein the vertical casting apparatus according to any one of (1) and (6) the gas pressurized hot water pouring pan is provided with heating means. (7) The above (1) to (6), wherein (7) the casting means has a vacuum suction mechanism that vacuum-sucks the gas in the mold cavity and vacuum-fills the molten metal in the gas pressurized hot pot. The vertical casting apparatus according to any one of the above and (8) the mold cavity includes a gas discharge passage, and the gas The vertical casting apparatus according to any one of (1) to (7), wherein a molten metal solidification zone gap communicating with the discharge passage is provided in the vicinity of the gas discharge passage, (9) The gas pressurized pouring pan has a molten metal supply pipe communicating with an opening provided in a lower part thereof, and an openable and closable hot water supply lid having a sealing force capable of withstanding gas pressure is provided at a molten metal supply pipe. The die-casting apparatus according to any one of (1) to (8), wherein:

The present invention is also (10) a casting method using the vertical casting apparatus according to any one of (1) to (9), wherein the molten metal is poured into the mold cavities from the gas pressure pouring pot through the casting stalk. After the molten metal is filled into the cavity, the molten metal inflow gate formed in the fixed mold is closed by the closing means, and then the molten metal in the mold cavity is pressurized by the pressing means. (11) After the molten metal inflow gate is closed with the closing means, the gas pressure in the gas pressurized molten metal pan is immediately released to the atmosphere and desorbed from the apparatus main body, and the molten metal required for the next time is gas pressurized molten metal. The vertical casting method according to (10) above, wherein the gas pressure in the gas pressurized hot water pan is 1 kg / It is adjusted to cm ² or more, in a short period of time at high speed The vertical casting method according to (10) or (11), or (13) wherein the cast product is a thin and large cast product of a light metal alloy. It is related with the vertical casting method as described in (12).

It is a schematic longitudinal cross-sectional view (at the time of the start of pouring) of the vertical casting apparatus of this invention. It is a schematic longitudinal cross-sectional view (at the time of hot water supply) of the vertical casting apparatus of this invention. It is sectional drawing of AA of FIG. It is explanatory drawing which shows the filling state of the molten metal in the vertical casting apparatus of this invention. It is explanatory drawing which shows the operation state in the vertical casting apparatus of this invention following FIG. It is a metal mold | die schematic longitudinal cross-sectional view when the vertical casting apparatus of this invention is applied to aluminum wheel production. It is a schematic longitudinal cross-sectional view of the vertical casting apparatus which concerns on the other example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed mold 2 Movable mold 3 Fixed platen 4 Movable platen 6 Pouring pot (gas pressurizing pouring pot)
7, 16 Molten metal 8 Molten metal surface 8a Molten metal surface of hot water supply pipe 9 Mold cavity 10 Circular gate 11 Cavity first hot water reservoir 12 Side gate 13 Blocking pin 14 Pressure stem 15 Jet 17 Pressure gap for molten metal coagulation zone 18 Pressure stem gas discharge gap 19 Cavity second hot water reservoir 20 Pressure pin 21 Pressure pin molten metal solidification zone gap 22 Pressure pin outer periphery gas discharge gap 23 Pressure stem piston 24 Closure pin piston 25 Hydraulic cylinders 26a, 26b , 26c Pressure oil inlet 27 Pressure stem Seal packing 28 Closure pin Seal packing 29 Pressure stem Gas discharge passage 30 Pressure pin Piston 31 Pressure pin hydraulic cylinder 32 Pressure oil inlet 33 Pressure pin Seal packing 34 Pressure pin Gas discharge Passage 35 Mold seal groove 36 Pressure stem cooling water hole 37 Pressure pin Cooling water hole 38 Hot water pot seal packing 39 Stoke seal packing 40 Cast stalk 41 Pressurized gas inlet 42 Hot water ladle 43 Outer peripheral type 44 Molten metal supply pipe 45 Hot water inlet sleeve 46 Hot water inlet 47 Hot water outlet lid 48 Hot water inlet gas section 49 Gas outlet inlet 9a Aluminum wheel hub part 9b Aluminum wheel spoke part 9c Aluminum wheel rim flange part

  The vertical casting apparatus of the present invention includes a lower fixed mold and an upper movable mold capable of forming a mold cavity, a closing means for closing a molten metal inflow gate formed in the fixed mold, and a closed mold. A vertical casting apparatus comprising an apparatus main body having pressurizing means for pressurizing the molten metal in the mold cavity, and casting means for supplying and filling the molten metal into the mold cavity from below, wherein the casting The means is not particularly limited as long as it has a gas pressurized pouring pan that can be attached to and detached from the apparatus main body, and the vertical casting apparatus of the present invention has a high work efficiency and a low maintenance cost. When the vertical casting apparatus of the present invention is used together with the mold casting apparatus, it is possible to suitably cast a cast product that does not generate a shrinkage nest at the time of solidification and that does not involve gas, particularly a thin and large cast product. Can do. And although it does not specifically limit as this casting, A light metal alloy, especially an aluminum alloy with a large solidification shrinkage are preferable. Since aluminum shrinks by about 7% when solidified, the casting apparatus and casting method of the present invention, which can prevent the formation of shrinkage nests, are particularly thin and large-sized from molten metal made of light metal alloy such as aluminum alloy that has large solidification shrinkage. The present invention can be applied particularly advantageously when casting a cast product.

  The gas pressurizing pouring pot in the casting means is not particularly limited as long as it is a pouring pan capable of gas pressurization and can be attached to and detached from the apparatus main body. The gas pressurized hot water pot needs to have a sealed structure, but for example, a gas pressurized hot water pot with an open top can be provided with a lid, but the sealed structure can be formed by attaching it to the device body. It is preferable to do. As a configuration for forming a sealed structure by mounting on the apparatus main body, when the gas pressurized pouring pan has a cast stalk, the upper end of the cast stalk is brought into close contact with the apparatus main body to form a sealed structure. Specifically, for example, the upper surface of the stalk can be pressed against the lower surface of the gate entrance of the mold to form a sealed structure. In addition, when the apparatus main body is equipped with cast stalk, the upper end of the gas pressurized pouring pan can be brought into close contact with the apparatus main body to form a sealed structure. Specifically, for example, the upper surface of the gas pressurized pouring pan Can be pressed against the lower surface of the fixed plate to form a sealed structure, or can be pushed into a seal packing provided at the lower portion of the fixed plate of the fixed mold to form a sealed structure. At this time, it is preferable to make the upper part of the gas pressurized hot water pot smaller than the lower part and make it easy to seal the apparatus body.

  In this way, by using a gas pressurized pouring pan that can be attached to and detached from the apparatus main body, the molten metal can be introduced from, for example, a hot water ladle from above (opened) the gas pressurized pouring pan that has been detached (removed). The molten metal can be replenished very easily. Moreover, since the gas pressurization pouring pan can be removed and the inflow gate of the apparatus main body can be cleaned and sprayed for lubrication, it is very easy to perform maintenance.

  The gas pressurized hot water pouring pan may be provided with a molten metal supply pipe (a molten metal supply passage) communicated with an opening provided at a lower portion thereof. An openable and closable hot water supply lid with a durable sealing force is provided. Here, the lower part of the gas pressurized hot pot provided with an opening means a part below the molten metal surface in the molten metal pot (when full), can cast the molten metal more efficiently, and Since the molten metal can be more efficiently dropped from the stalk, it is preferably a portion below the lower end of the cast stalk. In this case, it is not always necessary to remove and move the gas pressurized molten metal pan during hot water supply, but when removing and supplying hot water, the moving distance can be shortened and the work can be performed more efficiently.

  Such a pressurized gas pouring pan is preferably provided with a heating means, whereby it is possible to suppress the generation of a solidified layer and to suppress the occurrence of defects in the cast product as much as possible due to good hot water circulation.

  Moreover, as a capacity | capacitance of a gas pressurization pouring pot, it is a capacity | capacitance which can accommodate the molten metal required, for example for 1-3 times of casting from the point of prevention of the enlargement of an apparatus and the ease of conveyance of a gas pressurization pouring pot. It is more preferable that the capacity is enough to accommodate the molten metal required for one casting. By making the capacity to accommodate the molten metal required for one casting, the amount of molten metal in the pouring pan at the time of each casting is always constant, so there is no need for pressure correction, and continuous filling is performed more simply. In addition, it is possible to suppress the mixing of oxides and entrainment of gas and to perform stable operation. That is, in the case of the capacity for multiple times, the liquid level at the time of each casting is different, and it is necessary to finely adjust the pressure, but by making the capacity that can accommodate the molten metal required for one casting There is no need to make such subtle adjustments.

  In addition, the downsizing of such gas pressurized pouring pans enables the gas pressure to be increased because the surface of the hot metal is raised and the volume of the gas part is reduced, and the quantitative supply of molten metal to the mold cavity is possible. In addition, the supply speed can be increased and the shot time lag can be shortened, and high-quality casting and casting of a large-sized cast product with a thin wall can be performed. Furthermore, by using such a pouring pan, the production cycle time is shortened, so that the productivity is improved.

  Moreover, it is preferable that the casting means has a vacuum suction mechanism that vacuum-sucks and fills the molten metal in the gas pressurization pouring pan by vacuuming the gas in the mold cavity in addition to the gas pressurization pouring pan. As a result, the mold cavity can be filled with the molten metal at a high speed, and the gas in the mold cavity can be discharged to prevent the gas from being entrained. This vacuum suction can be performed through a gas discharge passage which will be described later.

  As the mold cavities, mold cavities capable of casting a thin and large cast product are preferable. The mold cavities include a cavity product portion and a cavity hot water reservoir, and the cavity hot water reservoir is located above the molten metal inflow gate. It is more preferable to include a cavity first hot water reservoir, and one or more cavity second hot water reservoirs located near the end of the cavity product product portion on the side opposite to the cavity first hot water reservoir. And a cavity product part and a cavity 1st hot water reservoir communicate with each other via a side gate, and the cavity first hot water reservoir preferably has a larger volume than a cavity 2nd hot water reservoir. .

  The lower fixed mold is formed with a communicating portion between a casting stalk for filling and supplying molten metal from a lower pouring pot and a cavity first hot water reservoir portion, and a molten metal inflow gate is provided in the communicating portion. ing. The shape of the molten metal inflow gate is not particularly limited. However, in view of ease of processing or the like, a shape having a circular cross section is usually preferable. In this case, the inner diameter of the circular molten metal inflow gate is configured to be smaller than the inner diameter of the stalk. It is preferable to keep it. By configuring in this way, the molten metal filled and supplied from below can be ejected into the cavity first hot water reservoir, and, as will be described later, the molten metal is poured into the stalk that contributes to the defective casting product. It is possible to prevent the oxide film on the surface of the molten metal or the chill layer (solidified layer) generated by cooling on the inner surface of the stalk from entering the product.

  The closing means for closing the molten metal inflow gate formed in the fixed mold may be any means as long as it has a mechanism capable of closing the molten metal inflow gate. For example, the circular molten metal inflow gate can be opened and closed. In this case, the diameter of the insertion portion of the closing pin into the circular molten metal inflow gate is made slightly smaller than the inner diameter of the circular molten metal inflow gate. It is preferable from the viewpoint of occlusion and sealing. It is preferable to hold the closing pin so that it can move forward and backward in a liquid-tight manner with respect to the movable die. In the case of being held slidably densely, a closing pin can be provided coaxially and slidably in a liquid-tight manner at the center of the pressure stem.

As described above, when the pressurizing stem and the closing pin are disposed in the movable mold above the circular molten metal inflow gate, the circular cavity first hot water reservoir portion formed in a state in which they are retracted (raised). The diameter of the inlet is made larger than 1.4 times the diameter of the circular molten metal inflow gate, and the ceiling height of the hot water reservoir at the upper limit of the pressure stem and the closing pin is ejected from the circular molten metal inflow gate. It is preferable that the cavity first hot water reservoir is configured to be 10 mm or more higher than the height of the molten metal jet. Thus, when the diameter of the inlet of the hot water reservoir is 1.4 times or more the diameter of the circular gate, the height h of the molten metal jet is approximately v for the passage speed of the molten metal in the circular gate and g for the acceleration of gravity. when a, h = v ² / since 2g can be determined by the equation, when a faster rate of v = 2.0 m / sec the casting speed in the general range, ejection height h = 2. 0 ² /2g=0.204 mm

  In other words, if the ceiling height is set to 204 + 10 = 214 mm, the jet flow does not collide with the ceiling, the free surface is formed, the oxide film on the molten metal surface is confined without backflow, and gas entrainment due to the collision is also possible. Can be prevented.

  For example, the pouring / filling speed of the molten metal varies depending on the shape of the product, but generally the initial passing speed in the circular gate is preferably 1.0 to 2.4 m / sec. The height is usually about 50 to 300 mm, but when the height of the ceiling of the first cavern is higher than the height of the molten metal jet by 10 mm or more, a free surface was formed and remained on the hot water surface. The oxide film also remains on the surface, and the gas remaining in the upper part of the hot water reservoir is still contained and does not flow downward. There is no gas involved. On the other hand, if the jet velocity is low, it will not collide with the ceiling and there will be no gas entrainment, but the casting time will be longer, the speed at which the molten metal will flow through the cavity product will become slower, and cooling solidification will progress during this time, resistance Increases, the flow velocity further decreases, and the molten product is insufficiently filled in the cavity product part, and even if the pressure is applied, the pressure transmission is poor and the possibility of occurrence of shrinkage increases. Therefore, when the molten metal fills the first hot water reservoir and begins to enter the product section, it is preferable to increase the gas pressure in the pouring pan and adjust the casting speed so that the casting speed is as fast as possible. At this time, the first hot water reservoir is filled with molten metal, and this acts as a resistance so that the flow of the inflow gate does not entrap the oxide film or gas remaining on the ceiling.

  When supplying the molten metal with high-pressure gas, the casting speed is increased and the molten metal is less cooled and solidified in the cavity, and the driving force can fill the molten product into a narrow part of the cavity product part with high resistance. Even if the filling is insufficient, there is no problem because the volume is small and the filling can be performed by sufficient pressurization such as a pressure stem.

  As described above, when the cavity first hot water reservoir is formed in the cavity, the oxide film and the gas entrainment layer present at the uppermost portion of the hot water reservoir when the closing pin and the pressure stem are advanced (lowered). Stays at the upper end of the cavity first hot water reservoir without being extruded, and does not enter the cavity product section. Also, in the case of casting using a pouring pan, the Stoke pouring spout is under the surface of the pouring pan, and the oxide film generated on the pouring surface floats on the surface of the pouring pan, so it is not possible to enter Stoke Absent. The slight oxide film on the surface of the stalk inner bath is at the tip of the jet and completely jumps into the first reservoir of the cavity and does not flow out to the cavity product section through the side gate, but the oxide film is mixed into the cast product. This eliminates defects in cast products and variations in strength.

  Next, by pressurizing the molten metal filled in the closed mold cavity, it is possible to cast a cast product in which no shrinkage occurs during solidification and gas is not entrained by a jet. As a pressurizing means for pressurizing the molten metal in the closed mold cavity, it is slidably provided on the movable mold above the first hot water reservoir of the cavity, and a closing pin is slidable in the center. The pressurizing stem provided and the cavity first hot water reservoir are slidably disposed on the movable mold above the cavity second hot water reservoir located at a position separated from the cavity product portion. A pressure pin can be specifically exemplified. It is preferable to provide a plurality of pressure pins. The diameter is preferably 2/3 to 1 times the depth of the cavity second hot water reservoir. Further, these pressure stems and pressure pins are preferably used in combination. In this way, by pressurizing the molten metal from the pressure stem and the plurality of pressure pins located at separate positions, the pressure transmission distance to the molten metal in the cavity is shortened, so that the pressure is uniformly transmitted to the cavity product part. Therefore, it is possible to cast a cast product in which no shrinkage occurs during solidification with a small pressure. In addition, the pressure transmission distance of the molten metal in the cavity product part is further shortened by arranging the pressure stem and the pressure pin at appropriate positions according to the form of the product, and the pressure transmission is made more uniform and sufficient. In addition, it is possible to prevent the formation of a shrinkage nest with a smaller pressure.

  In conventional casting apparatuses, in general, in order to cast a cast product in which no shrinkage occurs during solidification, the pressurizing means of the molten metal by the pressurizing means is increased and rapidly pressurized. In this case, the pressure transmission is too good, the mold opening force is increased, the burr is blown, and the mold clamping force must be increased. However, if the pressurization rate is slowed down, it will not catch up with the solidification shrinkage of the molten metal, and a sinkhole will be generated. On the other hand, according to the present invention, uniform and sufficient pressure transmission can be performed even with a small mold clamping force that can prevent burrs from being blown. it can. As described above, in the present invention, the pressurization speed is controlled by performing program control so that the advancement speed of the pressurization stem and pressurization pin during pressurization becomes a speed adapted to the solidification contraction speed of the molten metal in the cavity product part. By adjusting it, it is possible to prevent the formation of sink marks while preventing burrs from being blown with a press device with a small clamping force. For example, the pressure and pressurizing speed for the molten metal during solidification shrinkage where Pascal's principle does not work Is controlled in accordance with the solidification rate within the range where burrs are not blown, so that a device with a small clamping force of 1/3 to 1/5 of the conventional high pressure method can be used. It is possible to obtain a cast product having a dense structure without gas entrainment.

  In addition, in the case of vertical casting methods such as squeeze casting, if the pressure applied by the acurad pin (center pin) is accelerated, the casting plunger will be pushed down. Since pressure is applied after the pressure transmission to the plunger is reduced, solidification of the molten metal in the cavity progresses during that time, and a large pressure is required for replenishing the molten metal. However, in the present invention, since the present invention is provided with a means for closing the molten metal inflow gate, it is possible to replenish and fill the molten metal by pressurizing from the stage where solidification is still progressing immediately after the closed gate. In addition, since the pressure is applied by the pressure stem and a plurality of pressure pins arranged at predetermined positions, the pressure transmission distance is short, and the pressure is uniform and charged with a small pressure. It can be performed Do refill packing. As a result of the pressure being reduced in this way, the mold clamping force of the mold can be reduced, and the costs of the mold clamping device and the mold can be kept low. In addition, this casting speed and pressurization start speed are faster than squeeze casting, thin wall casting is also possible, good heat transfer is maintained by maintaining contact with the mold surface of the molten metal, cooling time is short, crystal The quality is improved, the production cycle time is shortened, and the productivity is improved.

  In the vertical casting apparatus of the present invention, a gas discharge passage capable of discharging the gas existing in the cavity when the molten metal is filled in the mold cavity, and a gap for the molten metal solidification zone communicated with the gas discharge passage. Those having the following are preferred. The gas discharge passage is preferably constituted by a gas discharge hole penetrating through the movable mold and a gas discharge gap. The molten metal solidification zone gap is preferably provided in the vicinity of the gas discharge passage, and particularly preferably close to the pressurizing means. As the gap for the molten metal solidification zone, for example, after discharging the gas in the cavity from the gas discharge passage, the molten metal can be solidified in the gap that becomes the molten metal solidification zone. Any air gap can be used as long as it can seal and close the inside of the cavity. Just by providing such a gap for the molten metal solidification zone, an air vent valve, a filter, etc. are provided and a complicated switching valve or The inside of the cavities can be easily sealed and closed without using a valve, and complicated operations such as pressure adjustment are not required when the casting apparatus is operated, and further, there is no occurrence of failure. The device can be said to be very practical. In addition, the area of the docking surface between the upper surface of the stalk and the lower surface of the mold, or the upper surface of the pouring pan and the lower surface of the fixed platen is small, and a pressure seal for preventing pressurized gas from leaking during pouring can be easily achieved.

  Specifically, the molten metal solidification zone gap communicates with the gas discharge passage through a gas discharge gap formed between the outer peripheral surface of the pressure stem and / or the pressure pin and the inner peripheral surface of the movable mold. The molten metal solidification zone melting void can be exemplified, and the molten metal solidification zone void is provided concentrically with the pressure stem / or the pressure pin, and from the diameter of the pressure stem and / or the pressure pin. In addition, a void that becomes a molten metal solidification zone having an inner diameter that is 1 to 5 mm larger and a depth (length) of about 10 to 40 mm can be specifically exemplified. In this way, by setting the outer diameter of each hot water pool portion to be slightly larger than the outer shape of the pressure stem and the pressure pin, the solidified layer formed on the outer peripheral wall of each hot water pool portion can be increased by the pressure stem / While being pushed into the product by the pressure pin, the pressure resistance of the pressure stem and the pressure pin can be reduced. As described above, if the gap for the molten metal solidification zone is designed to have a size that matches the temperature of the molten metal and the casting speed, the hot water is cooled and solidified in the gap when the molten metal is filled, and the gas discharge gap Never invade.

  Further, the gas discharge gap preferably has a structure or size that does not allow the hot water to flow in. For example, the gas discharge gap is provided concentrically with the pressure stem and / or the pressure pin, and the pressure stem and / or A gas discharge gap having an inner diameter that is about 0.4 to 1.0 mm larger than the diameter of the pressure pin can be specifically mentioned. When the mold cavity is evacuated, in order to prevent intrusion of air, the parting surface is not provided with gas discharge holes and gas discharge passages. A gas exhaust groove connected to the gas exhaust port is provided to prevent air from leaking into the mold cavity from outside the mold.

  By the way, if the casting start speed of the molten metal by the combined use of the gas pressurized pouring pan and the vacuum suction mechanism is set to an optimum value of 1.0 to 2.4 m / sec, the molten metal provided close to the outer periphery of the pressure stem and the pressure pin. The air resistance in the two-stage gaps such as the solidification zone gap and the gas discharge gap is increased, but the purpose of installing the molten metal solidification zone gap and the gas discharge gap by appropriately selecting the number and arrangement of the pressure pins. Can be achieved. That is, those skilled in the art can easily design a structure in which the hot water is cooled and solidified in the melt solidification zone gap having a two-stage gap and does not enter the gas discharge gap narrower than the melt solidification zone gap. Also, in order to cool and solidify the hot water in the gap for the molten metal solidification zone, a material with good heat conduction, such as beryllium copper, is used for the pressure stem and pressure pin, and the inside can be cooled with water. You can also.

  As described above, in the vertical casting apparatus of the present invention described above, the structure of the gas discharge system around the pressurization stem and the pressurization pin is simple, and the occurrence of trouble during operation is reduced. In addition, the combined use of gas pressurization and a vacuum suction mechanism in a sealed small-volume pouring pan enables filling of the molten metal into the mold cavity at a high speed, thereby enabling casting of a large thin product and The prior hot water flows into the narrow melt solidification zone gap, so that it solidifies and stops there and does not enter the gas discharge gap passage. Further, by increasing the depth of the cavity 1st hot water reservoir, the stroke of the pressurization stem can be lengthened, and a sufficient volume of molten metal for replenishment filling and solidification shrinkage in the cavity product part can be obtained. In addition, it is possible to obtain a strong casting with a finer structure by adding pressure to reduce the crystal size by increasing the cooling rate. In addition, the circular gate is closed with a closing pin slightly smaller than the inner diameter of the circular gate, the gas pressure in the pouring pan is released to the atmosphere, and the molten metal in the stalk is quickly returned to the pouring pan by lowering it quickly. Prevents troubles caused by solidification.

  In addition, when the mold is opened, the pouring pan is taken out of the machine so that the inflow gate can be cleaned, and the mold surface can be cooled and lubricated easily and safely.

  In addition, in the casting apparatus of the present invention equipped with a pressurized gas pouring pan and a vacuum suction mechanism, when filling molten metal into the mold cavity, the gas in the cavity is almost completely discharged, and at the same time, the circular gate is closed after filling. Therefore, the necessary and sufficient pressure can be applied with a small pressure, so it can be handled with a clamping force of 1/3 to 1/5 that of the conventional high pressure method, and the cost of the casting apparatus is greatly reduced, and the productivity is also high. Since it is good, the cost of the casting can be greatly reduced. In addition, since the molten metal is supplied directly from the bottom of the pouring pan, the oxide film is not mixed in, and the passage is short, so there is little generation of a solidified layer, and the cavity has an appropriate height at the exit of the circular gate. By providing the first hot water reservoir, the jet flow does not collide with the ceiling, gas entrainment can be eliminated, and a slight remaining oxide film or solidified layer can be retained in the cavity first hot water reservoir. As a result, a cast product having a dense structure free of impurities can be obtained. Furthermore, as the hot pot is small and the gas pressure can be increased, a high casting speed can be secured, thin-wall casting becomes possible, and by moving the hot pot, it is easy to replenish the molten metal and the equipment cost is reduced. In addition, the arrangement and operation of the apparatus become easy.

Further, the vertical casting method of the present invention is a casting method using the vertical casting apparatus, in which the molten metal is cast into the mold cavity through the casting stalk from the gas pressure pouring pot, and the molten metal fills the cavity. After that, it is not particularly limited as long as it is a vertical casting method in which the molten metal inflow gate formed in the fixed mold is closed by the closing means, and then the molten metal in the mold cavities is pressed by the pressing means. The top of the gas pressurized pouring pan that has received the molten metal for the amount of pouring once or more is pushed into the seal packing provided at the bottom of the fixed plate and sealed, and a gas pressure of 1 kg / cm ² or more is preferably applied to the pouring pan. Pressurize the hot water surface in the hot pot and cast the molten metal into the mold cavity through casting stalk. At this time, when the gas pressurized pouring pan has a molten metal supply pipe, the same gas pressure may be simultaneously applied from above the molten metal surface of the supply pipe. Subsequently, after filling the cavity with molten metal, the molten metal inflow gate provided in the fixed mold is closed with a closing means, and then the molten metal in the mold cavity is pressurized with a pressure means (pressure pin), A cast product in which no shrinkage occurs at the time of solidification and no gas is entrained, preferably a thin and large cast product of a light metal alloy is cast.

  At the retreat position of the pressure pin, the filling of the molten metal into the mold cavities is started, the flow rate of the hot water is decelerated at the cavity second hot water reservoir, and the gas in the mold cavities is discharged from the gas discharge gap. It is preferable that the molten metal solidification zone gap is cooled and solidified, and after the molten metal is filled in the mold cavity, the molten metal in the hot water reservoir is pressurized by advancing one or more pressure pins. The pressure transfer distance by reducing the gas entrainment by performing vacuum degassing from the gas discharge gaps adjacent to the plurality of molten metal solidification zones and pressurizing the molten metal with a pressure stem and a plurality of pressure pins Is preferably shortened. By this replenishment filling, the contact of the molten metal with the mold surface is maintained, good heat transfer is maintained, the cooling rate is high, the coarsening of the crystal is prevented, and a small crystal structure is formed. When the molten metal is solidified and replenishment filling is completed, the movable mold is raised by the movable platen after a short cooling time, and the product material lifted together with the movable mold is moved by the pressure stem, the pressure pin and the extrusion pin. Then, by extruding with a push pin and then withdrawing from the pressure stem and the pressure pin and taking out the product material, a cast product with a dense structure can be obtained without generation of shrinkage and gas entrainment. In addition, in order to repeat this operation every time, the molten metal in the gap for the molten metal solidification zone is removed every time, and the gas discharge passage is not clogged, and the stalk upper surface and the lower surface of the mold of the mobile gas pressurized hot water pan When sealing by pressing, the contact area is small and sealing is easy.

  Although it is possible to work efficiently by casting using a plurality of gas pressurized pouring pots, the gas pressure in the gas pressurized molten pot is immediately released to the atmosphere after the molten metal inflow gate is closed by the closing means. At the same time, it is preferable to detach from the apparatus main body, supply the necessary molten metal for the next time, and attach it again to the apparatus main body to prepare for the next casting. Thereby, it can cast very efficiently using one gas pressurization pouring pot. In addition, when using a gas pressurized pouring pan equipped with a molten metal supply pipe, the gas in the pouring pan is released to the atmosphere, and the molten metal supply pipe is covered with or without detaching the molten metal pot from the apparatus body. Open and supply the next molten metal. After closing the molten metal inflow gate with the closing means, the gas in the pouring pan is released to the atmosphere and the gas in the hot water supply port of the molten metal supply pipe is sucked up to raise the molten metal surface in the molten metal supply pipe. By designing the surface so as to be pulled down to the lower end of the stalk, the molten metal in the stalk can be dropped more quickly, thereby making it possible to work more efficiently.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, the technical scope of this invention is not limited to these illustrations.

  1 is a schematic longitudinal sectional view of the vertical casting apparatus of the present invention (at the start of pouring), FIG. 2 is a schematic longitudinal sectional view of the vertical casting apparatus of the present invention (at the time of hot water supply), and FIG. A sectional view, FIG. 4 is explanatory drawing which shows the pushing-up state of a molten metal, FIG. 5 is explanatory drawing which shows the operation | movement state following FIG. 1 to 5, 1 is a fixed mold, 2 is a movable mold, 9 is a cavity product section, 10 is a circular gate, 11 is a cavity first reservoir, 13 is a closing pin, and 14 is a pressure stem. , 17 is a molten metal solidification zone gap (pressure stem outer periphery), 19 is a cavity second hot water reservoir, 20 is a pressure pin, 21 is a molten metal solidification zone gap (pressure pin outer periphery), and 29 is a pressurized stem gas discharge. The hole 34 is a pressurized pin gas discharge hole, 40 is a casting stalk, and 41 is a pressurized gas inlet.

  The casting apparatus of the present invention shown in FIGS. 1 to 5 is capable of moving up and down to perform mold closing, and a fixed mold 1 attached to a horizontal fixed platen 3 at the bottom of the casting apparatus, and casting. A movable mold 2 attached to a horizontal movable platen 4 at the upper part of the apparatus and a gas pressurized hot water pan 6 positioned below the fixed platen 3 are provided. By opening and closing the fixed mold 1 and the movable mold 2, the cavity product portion 9, the cavity first hot water reservoir portion 11, the cavity second hot water reservoir portion 19, the cavity product portion 9 and the cavity first hot water reservoir portion 11. A mold cavity having a side gate 12 that communicates with each other is formed. In addition, the mold is mounted by mounting a mold set including the fixed mold 1 and the movable mold 2 to which the cast stalk 40 is attached in a state in which the movable platen 4 of the mold clamping press device (not shown) is pulled up. Then, the movable platen 4 is lowered until it contacts the upper surface of the movable mold 2, and the fixed mold 1 is attached to the fixed platen 3 and the movable mold 2 is attached to the movable platen 4. The gas pressurized hot water pouring pan 6 is hermetically sealed by pushing its upper end into a seal packing 38 provided at the lower part of the fixed platen 3.

  The fixed mold 1 is provided with a cast stalk 40 that extends downward at a lower portion thereof, and a circular gate 10 for ejecting molten metal from the cast stalk 40. When the pressurized gas is fed from the pressurized gas inlet 41 and the inside of the cavity is depressurized, the molten metal 7 in the pouring pan 6 is pushed up in the casting stalk 40, and the cavity product is passed through the circular gate 10 of the fixed mold 1. The portion 9 is filled. The casting speed at this time is controlled by adjusting the gas pressure in the pouring pan 6 and the degree of vacuum in the cavity so that the passing speed of the circular gate 10 of the molten metal becomes a jet and jets upward. Has been.

In addition, as shown in FIG. 4, the inlet diameter d ₁ of the cavity first hot water reservoir 11 is configured to be 1.4 times or more the diameter of the circular gate 10, and the outer diameter ds of the pressurizing stem 14 is the hot water reservoir 11. velocity h = v ² / 2g (wherein h is the jet reaches the height, v is the circular gate passage; a is configured slightly smaller than the inlet diameter d _1, further cavity ceiling height of the first the basin are as defined in formula , G indicates the acceleration of gravity.) And is configured to be higher than the height h at which the molten metal jet 15 passing through the circular gate 10 reaches. Therefore, in the initial stage of filling, the jet does not form the ceiling of the cavity first hot water reservoir 11, and the free surface of the molten metal jet 15 is formed on the upper portion, and the downward flow of this portion disappears, so that the oxidation remaining slightly on the molten metal surface The film remains stationary, and the gas remaining on the upper part of the hot water reservoir 11 is not entrained in the molten metal 16. As a result, a slight oxide film and gas winding at the tip of the molten metal jet 15 passing through the circular gate 10 are obtained. The entrainment layer remains on the ceiling, and after the molten metal is filled in the hot water reservoir 11, the flow does not reach the ceiling even if the casting speed is increased, and only the oxide film and clean molten metal without gas entrainment are on the side. The cavity product portion 9 is filled through the gate 12.

  In addition, a hydraulic cylinder 25 is disposed in a liquid-tight manner on the movable mold 2 above the circular gate 10 via a seal packing 27, and a pressurizing stem 14 is attached to the hydraulic cylinder 25 by a hydraulic pressure. A pressurizing stem piston 23 that can be moved back and forth to the hot water reservoir 11 is housed via a seal packing 27, and the pressurizing stem piston 23 is provided with a closing pin 13 that can close the circular gate 10. A closing piston 24 that can be advanced and retracted is accommodated coaxially with the pressurizing stem piston 23. After filling the mold cavity with the molten metal, the closing pin 13 is advanced by the piston 24, the circular gate 10 is closed, and then the pressure stem 14 is advanced by the piston 23, and the cavity product part 9 is not yet filled. The molten metal for the void volume and the solidification shrinkage volume is pressurized and supplied from the cavity first hot water reservoir 11. At that time, since the stroke of the pressure stem 14 is large, a sufficient amount of molten metal can be replenished and pressure-filled.

  Even during pressurization by the pressurization stem 14, an oxide film slightly generated on the molten metal surface in the stalk, a solidified layer on the molten metal surface formed by cooling at the inlet of the circular gate 10, and gas entrainment generated by a jet flow All the layers gather at the uppermost part of the hot water reservoir 11 by the gate jet 15, remain on the upper part of the cavity first hot water reservoir 11 without being pushed out by the pressure stem 14, and flow into the cavity product portion 9. As a result, there are no casting defects caused by these. Further, on the outside of the pressurization stem 14, a two-stage gap including a gas discharge gap 18 communicating with the gas discharge hole 29 and a molten metal solidification zone gap 17 is provided. As shown in FIG. 5d, the molten metal solidification zone gap 17 and the gas discharge gap 18 are taken out together with the product material since the solidified layer formed by the molten metal solidification zone gap 17 and the gas discharge gap 18 is removed. Secured.

  As shown in FIGS. 1 and 2, one or two or more small cavity second hot water reservoirs 19 are formed above the end of the cavity product portion 9, and above the hot water reservoir 19. A hydraulic cylinder 31 is disposed in the movable mold, and a pressure pin piston 30 capable of advancing and retracting the pressure pin 20 to and from the cavity second hot water reservoir 19 by hydraulic pressure is accommodated in the hydraulic cylinder. ing. The one or more pressure pins 20 have an axial core parallel to the mold opening / closing direction and perpendicular to the mold parting surface, and are liquid-tightly provided on the movable mold 2 via a seal packing 33. Then, after replenishing and filling the cavity product part 9 by the pressurization stem 14, these pressurizing pins 20 are extruded, and the molten metal in the cavity product part 9 is pressurized via the cavity second hot water reservoir 19. ing. Further, the outer diameter of the pressure pin 20 is configured to be slightly smaller than the diameter of the inlet of the cavity second hot water reservoir 19. Since these pressurizing pins 20 also slide each time, the solidified layer formed by the molten metal solidification zone gap 21 is pushed out by an extruding pin (not shown) attached to the product material and does not remain in the gas passage hole, but the gas discharge passage every time. Is to be secured.

  Next, the operation of the vertical casting apparatus described above will be described. After the mold clamping is completed, the molten metal 16 in the pouring pan 6 is pushed up to the cavity first hot water reservoir 11 by the pressure of the pressurized gas fed into the gas pressurized hot pouring pan 6 and the vacuum suction force into the cavity. The molten metal 16 ascends in the casting stalk 40, passes through the circular gate 10 of the fixed mold 1, and is ejected (FIG. 4). In general, since there is a flow resistance in the cavity product portion 9, before the molten metal reaches the cavity second hot water reservoir 19 below the pressurizing pin, the cavity first hot water reservoir 11 in the upper part of the circular gate 10. Is filled with molten metal (FIG. 5a), but when the hot water enters the molten metal solidification zone gap 17 having a two-stage gap, the passage is narrow, the heat capacity of the molten metal is small, and on the contrary, the cooling area is large, so the cooling rate is high. Since the solidification progresses and the fluidity decreases, the tip of the molten metal stops in the middle of the molten metal solidification zone gap 17 and does not solidify and enter the gas discharge gap 18.

  When the flow of the molten metal in the cavity stops, it is detected as a filling completion signal, and the closing pin 13 is immediately advanced and inserted into the circular gate 10 to close it. (Figure 5b). Thus, after the molten metal in the cavity product section 9 and the cavity first hot water reservoir 11 is closed so as not to flow backward to the stock, the pressurization stem 14 is immediately advanced to pressurize the interior of the cavity first hot water reservoir 11. The cavity product part 9 is replenished and filled with the molten metal in a semi-solid state (FIG. 5c). When the filling is completed and the cooling is started, solidification shrinkage of the molten metal 16 occurs. Therefore, a high pressure is applied to the pressurizing stem 14 to advance and replenishment according to the solidification shrinkage volume is performed. At this time, the contact between the molten metal and the mold surface is maintained, the cooling rate is fast, and the crystals become small. Further, when the circular gate 10 is closed by the closing pin 13, even if the contact between the closing pin 13 and the circular gate 10 is not perfect, the molten metal present in the small gap is quickly cooled and solidified, and the cavity first hot water reservoir is added. Even if pressed, the molten metal does not flow backward from the circular gate 10 to the pouring pan 6 through the cast stalk 40. Therefore, as shown in FIG. 2, after closing the circular gate 10 with the closing pin 13, the gas pressure in the pouring pan is immediately released to the atmosphere, and the pouring pan 6 is positioned below the lower end of the stalk in a state where the gas pressure has dropped to no danger. The molten metal remaining in the casting stalk 40 is dropped into the pouring pan 6 by using a vertical movement device (not shown). The lowered pouring pan 6 is moved to a position outside the casting machine by a horizontal movement device (not shown), and the molten metal necessary for the next time is supplied by the hot water supply ladle 42, and is again attached to the apparatus main body to prepare for the next casting.

  In the case of refilling with the pressurizing stem 14, the molten metal temperature in the mold cavity is higher, the pressurizing distance is shorter, the pressure transmission resistance is significantly smaller than the conventional die casting method, and The force of the pressure cylinder is small, and the hydraulic pressure in the hydraulic cylinder can be advanced with low pressure. By the replenishment filling by the advancement of the pressurizing stem 14, the molten metal replenishes and fills the cavity product portion 9 and the cavity second hot water reservoir 19, and then the pressurization pin 20 is advanced. The pressurization by the pressurization pin 20 is started by detecting this because the flow resistance increases and the hydraulic pressure increases with the completion of the filling by the pressurization stem 14. Replenishment according to the solidification shrinkage volume by the advancement of the pressurization stem 14 is difficult to transmit pressure to the opposite end of the cavity product part 9, so that the pressurization pin 20 around the end is actuated to pressurize the entire surface. In particular, a product with a dense structure free from shrinkage due to coagulation contraction can be obtained. After completion of the cooling and solidification of the molten metal in the cavity product section 9, the mold material is opened and the product material lifted by the movable mold 2 can be extruded and taken out by the pressure pins and the extrusion pins (FIG. 5d).

  FIG. 6 shows a case where the vertical casting apparatus of the present invention is applied to the production of aluminum wheels. The molten metal that has passed through the gate 10 enters the hub portion 9a of the product aluminum wheel corresponding to the cavity hot water storage portion 11 in the first embodiment, passes through the spoke portion 9b of the aluminum wheel corresponding to the side gate 12, and has a circumferential shape. The rim flange portion 9c is entered. Cavity second hot water reservoirs 19 are provided at several locations on the circumference of the upper end of the rim flange 9c to perform degassing and pressurization. The other operations are the same as in the first embodiment, and an aluminum wheel of high quality can be cast. Further, according to this method, the cavity first hot water reservoir 11 and the side gate 12 in the first embodiment are the product 9 (aluminum wheel). ), And there is little excess molten metal, and the hole by the blocking pin becomes the shaft hole of the aluminum wheel, and the casting weight of the cavity first hot water reservoir 11, that is, the hub 9a is reduced, and the cooling solidification rate The cycle time is shortened, the casting productivity is increased, and the shaft hole machining time in machining is shortened. And a quick cooling rate can make a crystal small, and can show the beauty of the surface important for the design nature of an aluminum wheel.

  FIG. 7 shows another example of the vertical casting apparatus of the present invention. As shown in FIG. 7, in the vertical casting apparatus of the present invention, the gas pressurized pouring pan 7 is provided with a molten metal supply pipe 44 that communicates with an opening provided in the lower part thereof, and a hot water supply port 46 of the molten metal supply pipe 44 is provided. An openable and closable hot water supply lid 47 having a sealing force capable of withstanding gas pressurization is provided. The hot water supply sleeve 45 provided in the upper part of the molten metal supply pipe 44 in such a vertical casting apparatus is provided with a gas outlet 49, and when the gas is pressurized, the pressurized gas inlet above the gas pressurized hot water pouring pan 7 is provided. While the pressurized gas is supplied from 41 and the same pressurized gas is supplied also from the gas outlet 49, the molten metal can be supplied and filled more efficiently. Then, after the molten metal inflow gate 10 is closed by the closing means, the gas pressure in the gas pressurized molten metal pan 7 is immediately released to the atmosphere and the gas in the hot water supply port gas part 48 of the molten metal supply pipe 44 is vacuumed from the gas outlet 49. Then, the molten metal surface 8a in the molten metal supply pipe 44 is pulled up, the molten metal surface 8 in the molten metal pan 7 is lowered to the lower end of the stalk 40, and the molten metal in the stalk 40 is dropped more quickly.

  According to the present invention, molten metal is filled into a mold cavity at high speed, and the molten metal in the closed cavity is effectively pressurized to easily cast a cast product that is free from shrinkage and does not involve gas. It is possible to provide a vertical casting apparatus that has high working efficiency and is easy to maintain and has a low equipment cost, and a vertical casting method using the vertical casting apparatus.

  The present invention is a vertical casting apparatus capable of casting a cast product such as an aluminum alloy from below, and filling the mold cavities with molten metal from below. The present invention relates to a vertical casting apparatus for supplying and filling and a vertical casting method using the same.

  When casting a cast product such as a light alloy product, particularly a part that requires strength, a vertical casting apparatus is used to prevent gas entrainment during casting of the molten metal.

  In such vertical casting apparatuses, it is already known to use low-pressure gas as means for supplying molten metal from the molten metal holding furnace to the mold cavities while preventing the mixing of oxides and gas entrainment. (See JP 58-55166 A). However, the low-pressure gas is effective for quantitatively supplying the molten metal to the mold, but simply using the low-pressure gas has a low casting speed and a low pressure. It was not possible to prevent or sufficiently respond to thin-walled products. Further, in the conventional apparatus, a large amount of molten metal is accommodated in a molten metal holding furnace fixed to the apparatus main body, and the apparatus is enlarged. Furthermore, it is not easy to replenish the molten metal in the molten metal holding furnace fixed to the apparatus main body, and it is very difficult to perform a spraying operation for cleaning or lubricating the inflow gate of the apparatus main body.

In addition, one of the inventors of the present invention invented a method using an immersion type electromagnetic pump as a means for supplying molten metal to a mold cavity (see Japanese Patent Application Laid-Open No. 2003-266168). In order to cope with this problem, the electromagnetic pump becomes larger and the apparatus becomes larger, making it difficult to put it to practical use.
JP 58-55166 A JP 2003-266168 A

  In casting by a vertical casting apparatus, in order to cast a high-quality casting product, particularly a thin-walled and large-sized casting product, it is necessary to fill the mold cavity with molten metal at a high speed. Also, in order to prevent the inclusion of oxides and gas entrainment that cause defective defects in castings, and to prevent shrinkage caused by solidification shrinkage, it is effective to fill the molten metal from below and use a sufficient amount of molten metal. It is necessary to replenish with pressure. At that time, in order to reduce trouble during operation, it is necessary to simplify the structure of the cavity and the structure of the entire casting apparatus. Work efficiency and ease of maintenance are also very important factors.

  An object of the present invention is to fill a mold cavity with molten metal at high speed, and effectively pressurize the molten metal in the closed cavity, thereby easily casting a cast product without generation of sink marks and without entrainment of gas. It is an object of the present invention to provide a vertical casting apparatus that has high working efficiency and is easy to maintain and has a low equipment cost, and a vertical casting method using the vertical casting apparatus.

  The present inventors have intensively studied to solve the above-mentioned problems, and by using a gas pressurized hot pot that can be attached / detached with the apparatus main body, it is possible to obtain a vertical casting apparatus that has high work efficiency and is easy to maintain and has low equipment costs. It is possible to supply the molten metal at a high speed by increasing the gas pressure of the gas pressurized hot water pan, and to find that it is possible to cast a cast product with no oxide film mixing and gas entrainment, The present invention has been completed. Furthermore, after the cast molten metal is filled in the cavity, if the molten metal in such a closed state is effectively pressurized by shortening the pressure transmission distance at a plurality of locations, there is no generation of shrinkage and the inclusion of oxide film and gas. The present inventors have found that it is possible to cast a cast product that does not involve winding, and have completed the present invention.

That is, the present invention provides (1) a lower fixed mold and an upper movable mold capable of forming a mold cavity, a closing means for closing a molten metal inflow gate formed in the fixed mold, and a closed mold. A vertical casting apparatus comprising an apparatus main body having a pressurizing means for pressurizing molten metal in a mold cavity, and casting means for supplying and filling molten metal into the mold cavity from below, wherein the casting means is A gas pressurized pouring pan that can be attached to and detached from the apparatus main body, and that can be attached to and detached from the apparatus main body , and the capacity of the gas pressurized pouring pot is a capacity that accommodates the molten metal required for one casting. (2) A vertical casting apparatus as described in (1) above, wherein a sealed structure is formed by attaching a gas pressurized pouring pan to the apparatus main body, 3) Gas pressurized hot water pan has cast stalk, The vertical casting apparatus according to the above (1) or (2), wherein the upper end portion of the cast stalk is brought into close contact with the apparatus main body, and (4) the apparatus main body performs the casting stalk. A vertical casting apparatus according to the above (1) or (2), or (5) a gas pressurized hot water pouring pan, wherein an upper end portion of the gas pressurized hot pouring pot is brought into close contact with the apparatus main body to form a sealed structure The vertical casting apparatus according to any one of the above (1) to (4) , characterized in that it comprises a heating means, and (6) the casting means vacuum sucks the gas in the mold cavity. And a vertical casting apparatus according to any one of the above (1) to (5) , characterized in that it has a vacuum suction mechanism that vacuum-fills the molten metal in the gas pressurized pouring pan, and (7) a mold cavity A gas discharge passage is provided, and the molten metal solidification zone gap communicating with the gas discharge passage is And vertical casting apparatus according to any one of to, characterized in that provided in the vicinity of the scan discharge passage (1) to (6), is (8) Gas pressure injection Yunabe, provided thereunder (1) to ( 1), characterized in that a molten metal supply pipe communicating with the opening is provided, and an openable and closable hot water supply lid having a sealing force capable of withstanding gas pressurization is provided at the molten metal supply pipe. 7) The vertical casting apparatus according to any one of the above.

The present invention also includes: (9) a lower fixed mold and an upper movable mold capable of forming a mold cavity; a closing means for closing a molten metal inflow gate formed in the fixed mold; and An apparatus main body having a pressurizing means for pressurizing the molten metal in the mold cavity, and a casting means having a gas pressurizing pouring pot that can be attached to and detached from the apparatus main body to supply and fill the molten metal into the mold cavity from below. Using a vertical casting apparatus equipped with a slag, the molten metal is cast into the mold cavities from the gas pressurized pouring pan through casting stalk, and after the molten metal fills the cavities, the molten metal inflow gate formed in the fixed mold is closed. And then pressurizing the molten metal in the mold cavity with the pressurizing means, and after closing the molten metal inflow gate with the closing means, immediately releases the gas pressure in the gas pressurized molten metal pan to the atmosphere. Dress A vertical casting method characterized in that it is desorbed from the mounting body, the next required molten metal is supplied to the gas pressurization molten metal pan, and is again mounted on the apparatus main body to prepare for the next casting, or (10) gas The vertical casting method according to (9) above, characterized in that the gas pressure in the pressurized pouring pan is adjusted to 1 kg / cm ² or more, and casting is performed at high speed in a short time, (11) The present invention relates to the vertical casting method according to (9) or (10) , wherein the casting is a thin and large casting of a light metal alloy.

  The vertical casting apparatus of the present invention includes a lower fixed mold and an upper movable mold capable of forming a mold cavity, a closing means for closing a molten metal inflow gate formed in the fixed mold, and a closed mold. A vertical casting apparatus comprising an apparatus main body having pressurizing means for pressurizing the molten metal in the mold cavity, and casting means for supplying and filling the molten metal into the mold cavity from below, wherein the casting The means is not particularly limited as long as it has a gas pressurized pouring pan that can be attached to and detached from the apparatus main body, and the vertical casting apparatus of the present invention has a high work efficiency and a low maintenance cost. When the vertical casting apparatus of the present invention is used together with the mold casting apparatus, it is possible to suitably cast a cast product that does not generate a shrinkage nest at the time of solidification and that does not involve gas, particularly a thin and large cast product. Can do. And although it does not specifically limit as this casting, A light metal alloy, especially an aluminum alloy with a large solidification shrinkage are preferable. Since aluminum shrinks by about 7% when solidified, the casting apparatus and casting method of the present invention, which can prevent the formation of shrinkage nests, are particularly thin and large-sized from molten metal made of light metal alloy such as aluminum alloy that has large solidification shrinkage. The present invention can be applied particularly advantageously when casting a cast product.

  The gas pressurizing pouring pot in the casting means is not particularly limited as long as it is a pouring pan capable of gas pressurization and can be attached to and detached from the apparatus main body. The gas pressurized hot water pot needs to have a sealed structure, but for example, a gas pressurized hot water pot with an open top can be provided with a lid, but the sealed structure can be formed by attaching it to the device body. It is preferable to do. As a configuration for forming a sealed structure by mounting on the apparatus main body, when the gas pressurized pouring pan has a cast stalk, the upper end of the cast stalk is brought into close contact with the apparatus main body to form a sealed structure. Specifically, for example, the upper surface of the stalk can be pressed against the lower surface of the gate entrance of the mold to form a sealed structure. In addition, when the apparatus main body is equipped with cast stalk, the upper end of the gas pressurized pouring pan can be brought into close contact with the apparatus main body to form a sealed structure. Specifically, for example, the upper surface of the gas pressurized pouring pan Can be pressed against the lower surface of the fixed plate to form a sealed structure, or can be pushed into a seal packing provided at the lower portion of the fixed plate of the fixed mold to form a sealed structure. At this time, it is preferable to make the upper part of the gas pressurized hot water pot smaller than the lower part and make it easy to seal the apparatus body.

  In this way, by using a gas pressurized pouring pan that can be attached to and detached from the apparatus main body, the molten metal can be introduced from, for example, a hot water ladle from above (opened) the gas pressurized pouring pan that has been detached (removed). The molten metal can be replenished very easily. Moreover, since the gas pressurization pouring pan can be removed and the inflow gate of the apparatus main body can be cleaned and sprayed for lubrication, it is very easy to perform maintenance.

  The gas pressurized hot water pouring pan may be provided with a molten metal supply pipe (a molten metal supply passage) communicated with an opening provided at a lower portion thereof. An openable and closable hot water supply lid with a durable sealing force is provided. Here, the lower part of the gas pressurized hot pot provided with an opening means a part below the molten metal surface in the molten metal pot (when full), can cast the molten metal more efficiently, and Since the molten metal can be more efficiently dropped from the stalk, it is preferably a portion below the lower end of the cast stalk. In this case, it is not always necessary to remove and move the gas pressurized molten metal pan during hot water supply, but when removing and supplying hot water, the moving distance can be shortened and the work can be performed more efficiently.

  Such a pressurized gas pouring pan is preferably provided with a heating means, whereby it is possible to suppress the generation of a solidified layer and to suppress the occurrence of defects in the cast product as much as possible due to good hot water circulation.

  Moreover, as a capacity | capacitance of a gas pressurization pouring pot, it is a capacity | capacitance which can accommodate the molten metal required, for example for 1-3 times of casting from the point of prevention of the enlargement of an apparatus and the ease of conveyance of a gas pressurization pouring pot. It is more preferable that the capacity is enough to accommodate the molten metal required for one casting. By making the capacity to accommodate the molten metal required for one casting, the amount of molten metal in the pouring pan at the time of each casting is always constant, so there is no need for pressure correction, and continuous filling is performed more simply. In addition, it is possible to suppress the mixing of oxides and entrainment of gas and to perform stable operation. That is, in the case of the capacity for multiple times, the liquid level at the time of each casting is different, and it is necessary to finely adjust the pressure, but by making the capacity that can accommodate the molten metal required for one casting There is no need to make such subtle adjustments.

  In addition, the downsizing of such gas pressurized pouring pans enables the gas pressure to be increased because the surface of the hot metal is raised and the volume of the gas part is reduced, and the quantitative supply of molten metal to the mold cavity is possible. In addition, the supply speed can be increased and the shot time lag can be shortened, and high-quality casting and casting of a large-sized cast product with a thin wall can be performed. Furthermore, by using such a pouring pan, the production cycle time is shortened, so that the productivity is improved.

  Moreover, it is preferable that the casting means has a vacuum suction mechanism that vacuum-sucks and fills the molten metal in the gas pressurization pouring pan by vacuuming the gas in the mold cavity in addition to the gas pressurization pouring pan. As a result, the mold cavity can be filled with the molten metal at a high speed, and the gas in the mold cavity can be discharged to prevent the gas from being entrained. This vacuum suction can be performed through a gas discharge passage which will be described later.

  As the mold cavities, mold cavities capable of casting a thin and large cast product are preferable. The mold cavities include a cavity product portion and a cavity hot water reservoir, and the cavity hot water reservoir is located above the molten metal inflow gate. It is more preferable to include a cavity first hot water reservoir, and one or more cavity second hot water reservoirs located near the end of the cavity product product portion on the side opposite to the cavity first hot water reservoir. And a cavity product part and a cavity 1st hot water reservoir communicate with each other via a side gate, and the cavity first hot water reservoir preferably has a larger volume than a cavity 2nd hot water reservoir. .

  The lower fixed mold is formed with a communicating portion between a casting stalk for filling and supplying molten metal from a lower pouring pot and a cavity first hot water reservoir portion, and a molten metal inflow gate is provided in the communicating portion. ing. The shape of the molten metal inflow gate is not particularly limited. However, in view of ease of processing or the like, a shape having a circular cross section is usually preferable. In this case, the inner diameter of the circular molten metal inflow gate is configured to be smaller than the inner diameter of the stalk. It is preferable to keep it. By configuring in this way, the molten metal filled and supplied from below can be ejected into the cavity first hot water reservoir, and, as will be described later, the molten metal is poured into the stalk that contributes to the defective casting product. It is possible to prevent the oxide film on the surface of the molten metal or the chill layer (solidified layer) generated by cooling on the inner surface of the stalk from entering the product.

  The closing means for closing the molten metal inflow gate formed in the fixed mold may be any means as long as it has a mechanism capable of closing the molten metal inflow gate. For example, the circular molten metal inflow gate can be opened and closed. In this case, the diameter of the insertion portion of the closing pin into the circular molten metal inflow gate is made slightly smaller than the inner diameter of the circular molten metal inflow gate. It is preferable from the viewpoint of occlusion and sealing. It is preferable to hold the closing pin so that it can move forward and backward in a liquid-tight manner with respect to the movable mold. In the case of being held slidably densely, a closing pin can be provided coaxially and slidably in a liquid-tight manner at the center of the pressure stem.

As described above, when the pressurizing stem and the closing pin are disposed in the movable mold above the circular molten metal inflow gate, the circular cavity first hot water reservoir portion formed in a state in which they are retracted (raised). The diameter of the inlet is made larger than 1.4 times the diameter of the circular molten metal inflow gate, and the ceiling height of the hot water reservoir at the upper limit of the pressure stem and the closing pin is ejected from the circular molten metal inflow gate. It is preferable that the cavity first hot water reservoir is configured to be 10 mm or more higher than the height of the molten metal jet. Thus, when the diameter of the inlet of the hot water reservoir is 1.4 times or more the diameter of the circular gate, the height h of the molten metal jet is approximately v for the passage speed of the molten metal in the circular gate and g for the acceleration of gravity. when a, h = v ² / since 2g can be determined by the equation, when a faster rate of v = 2.0 m / sec the casting speed in the general range, ejection height h = 2. 0 ² /2g=0.204 mm

  In other words, if the ceiling height is set to 204 + 10 = 214 mm, the jet flow does not collide with the ceiling, the free surface is formed, the oxide film on the molten metal surface is confined without backflow, and gas entrainment due to the collision is also possible. Can be prevented.

  For example, the pouring / filling speed of the molten metal varies depending on the shape of the product, but generally the initial passing speed in the circular gate is preferably 1.0 to 2.4 m / sec. The height is usually about 50 to 300 mm, but when the height of the ceiling of the first cavern is higher than the height of the molten metal jet by 10 mm or more, a free surface was formed and remained on the hot water surface. The oxide film also remains on the surface, and the gas remaining in the upper part of the hot water reservoir is still contained and does not flow downward. There is no gas involved. On the other hand, if the jet velocity is low, it will not collide with the ceiling and there will be no gas entrainment, but the casting time will be longer, the speed at which the molten metal will flow through the cavity product will become slower, and cooling solidification will progress during this time, resistance Increases, the flow velocity further decreases, and the molten product is insufficiently filled in the cavity product part, and even if the pressure is applied, the pressure transmission is poor and the possibility of occurrence of shrinkage increases. Therefore, when the molten metal fills the first hot water reservoir and begins to enter the product section, it is preferable to increase the gas pressure in the pouring pan and adjust the casting speed so that the casting speed is as fast as possible. At this time, the first hot water reservoir is filled with molten metal, and this acts as a resistance so that the flow of the inflow gate does not entrap the oxide film or gas remaining on the ceiling.

  When supplying the molten metal with high-pressure gas, the casting speed is increased and the molten metal is less cooled and solidified in the cavity, and the driving force can fill the molten product into a narrow part of the cavity product part with high resistance. Even if the filling is insufficient, there is no problem because the volume is small and the filling can be performed by sufficient pressurization such as a pressure stem.

  As described above, when the cavity first hot water reservoir is formed in the cavity, the oxide film and the gas entrainment layer present at the uppermost portion of the hot water reservoir when the closing pin and the pressure stem are advanced (lowered). Stays at the upper end of the cavity first hot water reservoir without being extruded, and does not enter the cavity product section. Also, in the case of casting using a pouring pan, the Stoke pouring spout is under the surface of the pouring pan, and the oxide film generated on the pouring surface floats on the surface of the pouring pan, so it is not possible to enter Stoke Absent. The slight oxide film on the surface of the stalk inner bath is at the tip of the jet and completely jumps into the first reservoir of the cavity and does not flow out to the cavity product section through the side gate, but the oxide film is mixed into the cast product. This eliminates defects in cast products and variations in strength.

  Next, by pressurizing the molten metal filled in the closed mold cavity, it is possible to cast a cast product in which no shrinkage occurs during solidification and gas is not entrained by a jet. As a pressurizing means for pressurizing the molten metal in the closed mold cavity, it is slidably provided on the movable mold above the first hot water reservoir of the cavity, and a closing pin is slidable in the center. The pressurizing stem provided and the cavity first hot water reservoir are slidably disposed on the movable mold above the cavity second hot water reservoir located at a position separated from the cavity product portion. A pressure pin can be specifically exemplified. It is preferable to provide a plurality of pressure pins. The diameter is preferably 2/3 to 1 times the depth of the cavity second hot water reservoir. Further, these pressure stems and pressure pins are preferably used in combination. In this way, by pressurizing the molten metal from the pressure stem and the plurality of pressure pins located at separate positions, the pressure transmission distance to the molten metal in the cavity is shortened, so that the pressure is uniformly transmitted to the cavity product part. Therefore, it is possible to cast a cast product in which no shrinkage occurs during solidification with a small pressure. In addition, the pressure transmission distance of the molten metal in the cavity product part is further shortened by arranging the pressure stem and the pressure pin at appropriate positions according to the form of the product, and the pressure transmission is made more uniform and sufficient. In addition, it is possible to prevent the formation of a shrinkage nest with a smaller pressure.

  In conventional casting apparatuses, in general, in order to cast a cast product in which no shrinkage occurs during solidification, the pressurizing means of the molten metal by the pressurizing means is increased and rapidly pressurized. In this case, the pressure transmission is too good, the mold opening force is increased, the burr is blown, and the mold clamping force must be increased. However, if the pressurization rate is slowed down, it will not catch up with the solidification shrinkage of the molten metal, and a sinkhole will be generated. On the other hand, according to the present invention, uniform and sufficient pressure transmission can be performed even with a small mold clamping force that can prevent burrs from being blown. it can. As described above, in the present invention, the pressurization speed is controlled by performing program control so that the advancement speed of the pressurization stem and pressurization pin during pressurization becomes a speed adapted to the solidification contraction speed of the molten metal in the cavity product part. By adjusting it, it is possible to prevent the formation of sink marks while preventing burrs from being blown with a press device with a small clamping force. For example, the pressure and pressurizing speed for the molten metal during solidification shrinkage where Pascal's principle does not work Is controlled in accordance with the solidification rate within the range where burrs are not blown, so that a device with a small clamping force of 1/3 to 1/5 of the conventional high pressure method can be used. It is possible to obtain a cast product having a dense structure without gas entrainment.

  In addition, in the case of vertical casting methods such as squeeze casting, if the pressure applied by the acurad pin (center pin) is accelerated, the casting plunger will be pushed down. Since pressure is applied after the pressure transmission to the plunger is reduced, solidification of the molten metal in the cavity progresses during that time, and a large pressure is required for replenishing the molten metal. However, in the present invention, since the present invention is provided with a means for closing the molten metal inflow gate, it is possible to replenish and fill the molten metal by pressurizing from the stage where solidification is still progressing immediately after the closed gate. In addition, since the pressure is applied by the pressure stem and a plurality of pressure pins arranged at predetermined positions, the pressure transmission distance is short, and the pressure is uniform and charged with a small pressure. It can be performed Do refill packing. As a result of the pressure being reduced in this way, the mold clamping force of the mold can be reduced, and the costs of the mold clamping device and the mold can be kept low. In addition, this casting speed and pressurization start speed are faster than squeeze casting, thin wall casting is also possible, good heat transfer is maintained by maintaining contact with the mold surface of the molten metal, cooling time is short, crystal The quality is improved, the production cycle time is shortened, and the productivity is improved.

  Further, in the vertical casting apparatus of the present invention, a gas discharge passage capable of discharging the gas existing in the cavity when the molten metal is filled in the mold cavity, and a gap for the molten metal solidification zone communicated with the gas discharge passage. Those having the following are preferred. The gas discharge passage is preferably configured by a gas discharge hole penetrating through the movable mold and a gas discharge gap. The molten metal solidification zone gap is preferably provided in the vicinity of the gas discharge passage, and particularly preferably close to the pressurizing means. As the gap for the molten metal solidification zone, for example, after discharging the gas in the cavity from the gas discharge passage, the molten metal can be solidified in the gap that becomes the molten metal solidification zone. Any air gap can be used as long as it can seal and close the inside of the cavity, and simply by providing such a gap for the molten metal solidification zone, an air vent valve, a filter, etc. are provided and a complicated switching valve or The inside of the cavities can be easily sealed and closed without using a valve, and there is no need for complicated operations such as pressure adjustment when the casting apparatus is in operation. The device can be said to be very practical. Further, the area of the docking surface between the upper surface of the stalk and the lower surface of the mold, or the upper surface of the pouring pan and the lower surface of the fixed platen is small, and a pressure seal for preventing pressurized gas from leaking during pouring can be easily achieved.

  Specifically, the molten metal solidification zone gap communicates with the gas discharge passage through a gas discharge gap formed between the outer peripheral surface of the pressure stem and / or the pressure pin and the inner peripheral surface of the movable mold. The molten metal solidification zone melting void can be exemplified, and the molten metal solidification zone void is provided concentrically with the pressure stem / or the pressure pin, and from the diameter of the pressure stem and / or the pressure pin. In addition, a void that becomes a molten metal solidification zone having an inner diameter that is 1 to 5 mm larger and a depth (length) of about 10 to 40 mm can be specifically exemplified. In this way, by setting the outer diameter of each hot water pool portion to be slightly larger than the outer shape of the pressure stem and the pressure pin, the solidified layer formed on the outer peripheral wall of each hot water pool portion can be increased by the pressure stem / While being pushed into the product by the pressure pin, the pressure resistance of the pressure stem and the pressure pin can be reduced. As described above, if the gap for the molten metal solidification zone is designed to have a size that matches the temperature of the molten metal and the casting speed, the hot water is cooled and solidified in the gap when the molten metal is filled, and the gas discharge gap Never invade.

  Further, the gas discharge gap preferably has a structure or size that does not allow the hot water to flow in. For example, the gas discharge gap is provided concentrically with the pressure stem and / or the pressure pin, and the pressure stem and / or A gas discharge gap having an inner diameter that is about 0.4 to 1.0 mm larger than the diameter of the pressure pin can be specifically mentioned. When the mold cavity is evacuated, in order to prevent intrusion of air, the parting surface is not provided with gas discharge holes and gas discharge passages. A gas exhaust groove connected to the gas exhaust port is provided to prevent air from leaking into the mold cavity from outside the mold.

  By the way, if the casting start speed of the molten metal by the combined use of the gas pressurized pouring pan and the vacuum suction mechanism is set to an optimum value of 1.0 to 2.4 m / sec, the molten metal provided close to the outer periphery of the pressure stem and the pressure pin. The air resistance in the two-stage gaps such as the solidification zone gap and the gas discharge gap is increased, but the purpose of installing the molten metal solidification zone gap and the gas discharge gap by appropriately selecting the number and arrangement of the pressure pins. Can be achieved. That is, those skilled in the art can easily design a structure in which the hot water is cooled and solidified in the melt solidification zone gap having a two-stage gap and does not enter the gas discharge gap narrower than the melt solidification zone gap. Also, in order to cool and solidify the hot water in the gap for the molten metal solidification zone, a material with good heat conduction, such as beryllium copper, is used for the pressure stem and pressure pin, and the inside can be cooled with water. You can also.

  As described above, in the vertical casting apparatus of the present invention described above, the structure of the gas discharge system around the pressure stem and the pressure pin is simple, and the occurrence of trouble during operation is reduced. In addition, by combining gas pressurization and a vacuum suction mechanism in a sealed small-volume pouring pan, it is possible to cast a large thin product by filling the mold cavity at high speed, The hot water flows into the narrow molten metal solidification zone gap, so that it solidifies and stops there and does not enter the gas discharge gap passage. In addition, by increasing the depth of the cavity 1st hot water reservoir, the stroke of the pressurization stem can be lengthened, and a sufficient volume of molten metal for refilling and coagulation shrinkage in the cavity product part can be obtained. In addition, it is possible to obtain a strong casting with a denser structure by adding pressure to reduce the crystal by increasing the cooling rate. In addition, the circular gate is closed with a closing pin slightly smaller than the inner diameter of the circular gate, the gas pressure in the pouring pan is released to the atmosphere, and the molten metal in the stalk is quickly returned to the pouring pan by lowering it quickly. Prevents troubles caused by solidification.

  In addition, when the mold is opened, the pouring pan is taken out of the machine so that the inflow gate can be cleaned, and the mold surface can be cooled and lubricated easily and safely.

  In addition, in the casting apparatus of the present invention equipped with a pressurized gas pouring pan and a vacuum suction mechanism, when filling molten metal into the mold cavity, the gas in the cavity is almost completely discharged, and at the same time, the circular gate is closed after filling. Therefore, the necessary and sufficient pressure can be applied with a small pressure, so it can be handled with a clamping force of 1/3 to 1/5 that of the conventional high pressure method, and the cost of the casting apparatus is greatly reduced, and the productivity is also high. Since it is good, the cost of the casting can be greatly reduced. In addition, since the molten metal is supplied directly from the bottom of the pouring pan, the oxide film is not mixed in, and the passage is short, so there is little generation of a solidified layer, and the cavity has an appropriate height at the exit of the circular gate. By providing the first hot water reservoir, the jet flow does not collide with the ceiling, gas entrainment can be eliminated, and a slight remaining oxide film or solidified layer can be retained in the cavity first hot water reservoir. As a result, a cast product having a dense structure free of impurities can be obtained. Furthermore, as the hot pot is small and the gas pressure can be increased, a high casting speed can be secured, thin-wall casting becomes possible, and by moving the hot pot, it is easy to replenish the molten metal and the equipment cost is reduced. In addition, the arrangement and operation of the apparatus become easy.

Further, the vertical casting method of the present invention is a casting method using the vertical casting apparatus, in which the molten metal is cast into the mold cavity through the casting stalk from the gas pressure pouring pot, and the molten metal fills the cavity. After that, it is not particularly limited as long as it is a vertical casting method in which the molten metal inflow gate formed in the fixed mold is closed by the closing means, and then the molten metal in the mold cavities is pressed by the pressing means. The top of the gas pressurized pouring pan that has received the molten metal for the amount of pouring once or more is pushed into the seal packing provided at the bottom of the fixed plate and sealed, and a gas pressure of 1 kg / cm ² or more is preferably applied to the pouring pan. Pressurize the hot water surface in the hot pot and cast the molten metal into the mold cavity through casting stalk. At this time, when the gas pressurized pouring pan has a molten metal supply pipe, the same gas pressure may be simultaneously applied from above the molten metal surface of the supply pipe. Subsequently, after filling the cavity with molten metal, the molten metal inflow gate provided in the fixed mold is closed with a closing means, and then the molten metal in the mold cavity is pressurized with a pressure means (pressure pin), A cast product in which no shrinkage occurs at the time of solidification and no gas is entrained, preferably a thin and large cast product of a light metal alloy is cast.

  At the retreat position of the pressure pin, the filling of the molten metal into the mold cavities is started, the flow rate of the hot water is decelerated at the cavity second hot water reservoir, and the gas in the mold cavities is discharged from the gas discharge gap. It is preferable that the molten metal solidification zone gap is cooled and solidified, and after the molten metal is filled in the mold cavity, the molten metal in the hot water reservoir is pressurized by advancing one or more pressure pins. The pressure transfer distance by reducing the gas entrainment by performing vacuum degassing from the gas discharge gaps adjacent to the plurality of molten metal solidification zones and pressurizing the molten metal with a pressure stem and a plurality of pressure pins Is preferably shortened. By this replenishment filling, the contact of the molten metal with the mold surface is maintained, good heat transfer is maintained, the cooling rate is high, the coarsening of the crystal is prevented, and a small crystal structure is formed. When the molten metal is solidified and replenishment filling is completed, the movable mold is raised by the movable platen after a short cooling time, and the product material lifted together with the movable mold is moved by the pressure stem, the pressure pin and the extrusion pin. Then, by extruding with a push pin and then withdrawing from the pressure stem and the pressure pin and taking out the product material, a cast product with a dense structure can be obtained without generation of shrinkage and gas entrainment. In addition, in order to repeat this operation every time, the molten metal in the gap for the molten metal solidification zone is removed every time, and the gas discharge passage is not clogged, and the stalk upper surface and the lower surface of the mold of the mobile gas pressurized hot water pan When sealing by pressing, the contact area is small and sealing is easy.

  Although it is possible to work efficiently by casting using a plurality of gas pressurized pouring pots, the gas pressure in the gas pressurized molten pot is immediately released to the atmosphere after the molten metal inflow gate is closed by the closing means. At the same time, it is preferable to detach from the apparatus main body, supply the necessary molten metal for the next time, and attach it again to the apparatus main body to prepare for the next casting. Thereby, it can cast very efficiently using one gas pressurization pouring pot. In addition, when using a gas pressurized pouring pan equipped with a molten metal supply pipe, the gas in the pouring pan is released to the atmosphere, and the molten metal supply pipe is covered with or without detaching the molten metal pot from the apparatus body. Open and supply the next molten metal. After closing the molten metal inflow gate with the closing means, the gas in the pouring pan is released to the atmosphere and the gas in the hot water supply port of the molten metal supply pipe is sucked up to raise the molten metal surface in the molten metal supply pipe. By designing the surface so as to be pulled down to the lower end of the stalk, the molten metal in the stalk can be dropped more quickly, thereby making it possible to work more efficiently.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, the technical scope of this invention is not limited to these illustrations.

  1 is a schematic longitudinal sectional view of the vertical casting apparatus of the present invention (at the start of pouring), FIG. 2 is a schematic longitudinal sectional view of the vertical casting apparatus of the present invention (at the time of hot water supply), and FIG. A sectional view, FIG. 4 is explanatory drawing which shows the pushing-up state of a molten metal, FIG. 5 is explanatory drawing which shows the operation | movement state following FIG. 1 to 5, 1 is a fixed mold, 2 is a movable mold, 9 is a cavity product section, 10 is a circular gate, 11 is a cavity first reservoir, 13 is a closing pin, and 14 is a pressure stem. , 17 is a molten metal solidification zone gap (pressure stem outer periphery), 19 is a cavity second hot water reservoir, 20 is a pressure pin, 21 is a molten metal solidification zone gap (pressure pin outer periphery), and 29 is a pressurized stem gas discharge. The hole 34 is a pressurized pin gas discharge hole, 40 is a casting stalk, and 41 is a pressurized gas inlet.

  The casting apparatus of the present invention shown in FIGS. 1 to 5 is capable of moving up and down to perform mold closing, and a fixed mold 1 attached to a horizontal fixed platen 3 at the bottom of the casting apparatus, and casting. A movable mold 2 attached to a horizontal movable platen 4 at the upper part of the apparatus and a gas pressurized hot water pan 6 positioned below the fixed platen 3 are provided. By opening and closing the fixed mold 1 and the movable mold 2, the cavity product portion 9, the cavity first hot water reservoir portion 11, the cavity second hot water reservoir portion 19, the cavity product portion 9 and the cavity first hot water reservoir portion 11. A mold cavity having a side gate 12 that communicates with each other is formed. In addition, the mold is mounted by mounting a mold set including the fixed mold 1 and the movable mold 2 to which the cast stalk 40 is attached in a state in which the movable platen 4 of the mold clamping press device (not shown) is pulled up. Then, the movable platen 4 is lowered until it contacts the upper surface of the movable mold 2, and the fixed mold 1 is attached to the fixed platen 3 and the movable mold 2 is attached to the movable platen 4. The gas pressurized hot water pouring pan 6 is hermetically sealed by pushing its upper end into a seal packing 38 provided at the lower part of the fixed platen 3.

  The fixed mold 1 is provided with a cast stalk 40 that extends downward at a lower portion thereof, and a circular gate 10 for ejecting molten metal from the cast stalk 40. When the pressurized gas is fed from the pressurized gas inlet 41 and the inside of the cavity is depressurized, the molten metal 7 in the pouring pan 6 is pushed up in the casting stalk 40, and the cavity product is passed through the circular gate 10 of the fixed mold 1. The portion 9 is filled. The casting speed at this time is controlled by adjusting the gas pressure in the pouring pan 6 and the degree of vacuum in the cavity so that the passing speed of the circular gate 10 of the molten metal becomes a jet and jets upward. Has been.

In addition, as shown in FIG. 4, the inlet diameter d ₁ of the cavity first hot water reservoir 11 is configured to be 1.4 times or more the diameter of the circular gate 10, and the outer diameter ds of the pressurizing stem 14 is the hot water reservoir 11. velocity h = v ² / 2g (wherein h is the jet reaches the height, v is the circular gate passage; a is configured slightly smaller than the inlet diameter d _1, further cavity ceiling height of the first the basin are as defined in formula , G indicates the acceleration of gravity.), And is configured to be higher than the height h at which the molten metal jet 15 passing through the circular gate 10 reaches. Therefore, in the initial stage of filling, the jet does not form the ceiling of the cavity first hot water reservoir 11, and the free surface of the molten metal jet 15 is formed on the upper portion, and the downward flow of this portion disappears, so that the oxidation remaining slightly on the molten metal surface The film remains stationary, and the gas remaining on the upper part of the hot water reservoir 11 is not entrained in the molten metal 16. As a result, a slight oxide film and gas winding at the tip of the molten metal jet 15 passing through the circular gate 10 are obtained. The entrainment layer remains on the ceiling, and after the molten metal is filled in the hot water reservoir 11, the flow does not reach the ceiling even if the casting speed is increased, and only the oxide film and clean molten metal without gas entrainment are on the side. The cavity product portion 9 is filled through the gate 12.

  In addition, a hydraulic cylinder 25 is disposed in a liquid-tight manner on the movable mold 2 above the circular gate 10 via a seal packing 27, and a pressurizing stem 14 is attached to the hydraulic cylinder 25 by a hydraulic pressure. A pressurizing stem piston 23 that can be moved back and forth to the hot water reservoir 11 is housed via a seal packing 27, and the pressurizing stem piston 23 is provided with a closing pin 13 that can close the circular gate 10. A closing piston 24 that can be advanced and retracted is accommodated coaxially with the pressurizing stem piston 23. After filling the mold cavity with the molten metal, the closing pin 13 is advanced by the piston 24, the circular gate 10 is closed, and then the pressure stem 14 is advanced by the piston 23, and the cavity product part 9 is not yet filled. The molten metal for the void volume and the solidification shrinkage volume is pressurized and supplied from the cavity first hot water reservoir 11. At that time, since the stroke of the pressure stem 14 is large, a sufficient amount of molten metal can be replenished and pressure-filled.

  Even during pressurization by the pressurization stem 14, an oxide film slightly generated on the molten metal surface in the stalk, a solidified layer on the molten metal surface formed by cooling at the inlet of the circular gate 10, and gas entrainment generated by a jet flow All the layers gather at the uppermost part of the hot water reservoir 11 by the gate jet 15, remain on the upper part of the cavity first hot water reservoir 11 without being pushed out by the pressure stem 14, and flow into the cavity product portion 9. As a result, there is no casting defect caused by these. Further, on the outside of the pressurization stem 14, a two-stage gap including a gas discharge gap 18 communicating with the gas discharge hole 29 and a molten metal solidification zone gap 17 is provided. As shown in FIG. 5d, the molten metal solidification zone gap 17 and the gas discharge gap 18 are taken out together with the product material since the solidified layer formed by the molten metal solidification zone gap 17 and the gas discharge gap 18 is removed. Secured.

  As shown in FIGS. 1 and 2, one or two or more small cavity second hot water reservoirs 19 are formed above the end of the cavity product portion 9, and above the hot water reservoir 19. A hydraulic cylinder 31 is disposed in the movable mold, and a pressure pin piston 30 capable of advancing and retracting the pressure pin 20 to and from the cavity second hot water reservoir 19 by hydraulic pressure is accommodated in the hydraulic cylinder. ing. The one or more pressure pins 20 have an axial core parallel to the mold opening / closing direction and perpendicular to the mold parting surface, and are liquid-tightly provided on the movable mold 2 via a seal packing 33. Then, after replenishing and filling the cavity product part 9 by the pressurization stem 14, these pressurizing pins 20 are extruded, and the molten metal in the cavity product part 9 is pressurized via the cavity second hot water reservoir 19. ing. Further, the outer diameter of the pressure pin 20 is configured to be slightly smaller than the diameter of the inlet of the cavity second hot water reservoir 19. Since these pressurizing pins 20 also slide each time, the solidified layer formed by the molten metal solidification zone gap 21 is pushed out by an extruding pin (not shown) attached to the product material and does not remain in the gas passage hole, but the gas discharge passage every time. Is to be secured.

  Next, the operation of the vertical casting apparatus described above will be described. After the mold clamping is completed, the molten metal 16 in the pouring pan 6 is pushed up to the cavity first hot water reservoir 11 by the pressure of the pressurized gas fed into the gas pressurized hot pouring pan 6 and the vacuum suction force into the cavity. The molten metal 16 ascends in the casting stalk 40, passes through the circular gate 10 of the fixed mold 1, and is ejected (FIG. 4). In general, since there is a flow resistance in the cavity product portion 9, before the molten metal reaches the cavity second hot water reservoir 19 below the pressurizing pin, the cavity first hot water reservoir 11 in the upper part of the circular gate 10. Is filled with molten metal (FIG. 5a), but when the hot water enters the molten metal solidification zone gap 17 having a two-stage gap, the passage is narrow, the heat capacity of the molten metal is small, and on the contrary, the cooling area is large, so the cooling rate is high. Since the solidification progresses and the fluidity decreases, the tip of the molten metal stops in the middle of the molten metal solidification zone gap 17 and does not solidify and enter the gas discharge gap 18.

  When the flow of the molten metal in the cavity stops, it is detected as a filling completion signal, and the closing pin 13 is immediately advanced and inserted into the circular gate 10 to close it. (Figure 5b). Thus, after the molten metal in the cavity product section 9 and the cavity first hot water reservoir 11 is closed so as not to flow backward to the stock, the pressurization stem 14 is immediately advanced to pressurize the interior of the cavity first hot water reservoir 11. The cavity product part 9 is replenished and filled with the molten metal in a semi-solid state (FIG. 5c). When the filling is completed and the cooling is started, solidification shrinkage of the molten metal 16 occurs. Therefore, a high pressure is applied to the pressurizing stem 14 to advance and replenishment according to the solidification shrinkage volume is performed. At this time, the contact between the molten metal and the mold surface is maintained, the cooling rate is fast, and the crystals become small. Further, when the circular gate 10 is closed by the closing pin 13, even if the contact between the closing pin 13 and the circular gate 10 is not perfect, the molten metal present in the small gap is quickly cooled and solidified, and the cavity first hot water reservoir is added. Even if pressed, the molten metal does not flow backward from the circular gate 10 to the pouring pan 6 through the cast stalk 40. Therefore, as shown in FIG. 2, after closing the circular gate 10 with the closing pin 13, the gas pressure in the pouring pan is immediately released to the atmosphere, and the pouring pan 6 is positioned below the lower end of the stalk in a state where the gas pressure has dropped to no danger. The molten metal remaining in the casting stalk 40 is dropped into the pouring pan 6 by using a vertical movement device (not shown). The lowered pouring pan 6 is moved to a position outside the casting machine by a horizontal movement device (not shown), and the molten metal necessary for the next time is supplied by the hot water supply ladle 42, and is again attached to the apparatus main body to prepare for the next casting.

  In the case of refilling with the pressurizing stem 14, the molten metal temperature in the mold cavity is higher, the pressurizing distance is shorter, the pressure transmission resistance is significantly smaller than the conventional die casting method, and The force of the pressure cylinder is small, and the hydraulic pressure in the hydraulic cylinder can be advanced with low pressure. By the replenishment filling by the advancement of the pressurizing stem 14, the molten metal replenishes and fills the cavity product portion 9 and the cavity second hot water reservoir 19, and then the pressurization pin 20 is advanced. The pressurization by the pressurization pin 20 is started by detecting this because the flow resistance increases and the hydraulic pressure increases with the completion of the filling by the pressurization stem 14. Replenishment according to the solidification shrinkage volume by the advancement of the pressurization stem 14 is difficult to transmit pressure to the opposite end of the cavity product part 9, so that the pressurization pin 20 around the end is actuated to pressurize the entire surface. In particular, a product with a dense structure free from shrinkage due to coagulation contraction can be obtained. After completion of the cooling and solidification of the molten metal in the cavity product section 9, the mold material is opened and the product material lifted by the movable mold 2 can be extruded and taken out by the pressure pins and the extrusion pins (FIG. 5d).

  FIG. 6 shows a case where the vertical casting apparatus of the present invention is applied to the production of aluminum wheels. The molten metal that has passed through the gate 10 enters the hub portion 9a of the product aluminum wheel corresponding to the cavity hot water storage portion 11 in the first embodiment, passes through the spoke portion 9b of the aluminum wheel corresponding to the side gate 12, and has a circumferential shape. The rim flange portion 9c is entered. Cavity second hot water reservoirs 19 are provided at several locations on the circumference of the upper end of the rim flange 9c to perform degassing and pressurization. The other operations are the same as in the first embodiment, and an aluminum wheel of high quality can be cast. Further, according to this method, the cavity first hot water reservoir 11 and the side gate 12 in the first embodiment are the product 9 (aluminum wheel). ), And there is little excess molten metal, and the hole by the blocking pin becomes the shaft hole of the aluminum wheel, and the casting weight of the cavity first hot water reservoir 11, that is, the hub 9a is reduced, and the cooling solidification rate The cycle time is shortened, the casting productivity is increased, and the shaft hole machining time in machining is shortened. And a quick cooling rate can make a crystal small, and can show the beauty of the surface important for the design nature of an aluminum wheel.

  FIG. 7 shows another example of the vertical casting apparatus of the present invention. As shown in FIG. 7, in the vertical casting apparatus of the present invention, the gas pressurized pouring pan 7 is provided with a molten metal supply pipe 44 that communicates with an opening provided in the lower part thereof, and a hot water supply port 46 of the molten metal supply pipe 44 is provided. An openable and closable hot water supply lid 47 having a sealing force capable of withstanding gas pressurization is provided. The hot water supply sleeve 45 provided in the upper part of the molten metal supply pipe 44 in such a vertical casting apparatus is provided with a gas outlet 49, and when the gas is pressurized, the pressurized gas inlet above the gas pressurized hot water pouring pan 7 is provided. While the pressurized gas is supplied from 41 and the same pressurized gas is supplied also from the gas outlet 49, the molten metal can be supplied and filled more efficiently. Then, after the molten metal inflow gate 10 is closed by the closing means, the gas pressure in the gas pressurized molten metal pan 7 is immediately released to the atmosphere and the gas in the hot water supply port gas part 48 of the molten metal supply pipe 44 is vacuumed from the gas outlet 49. Then, the molten metal surface 8a in the molten metal supply pipe 44 is pulled up, the molten metal surface 8 in the molten metal pan 7 is lowered to the lower end of the stalk 40, and the molten metal in the stalk 40 is dropped more quickly.

  According to the present invention, molten metal is filled into a mold cavity at high speed, and the molten metal in the closed cavity is effectively pressurized to easily cast a cast product that is free from shrinkage and does not involve gas. It is possible to provide a vertical casting apparatus that has high working efficiency and is easy to maintain and has a low equipment cost, and a vertical casting method using the vertical casting apparatus.

It is a schematic longitudinal cross-sectional view (at the time of the start of pouring) of the vertical casting apparatus of this invention. It is a schematic longitudinal cross-sectional view (at the time of hot water supply) of the vertical casting apparatus of this invention. It is sectional drawing of AA of FIG. It is explanatory drawing which shows the filling state of the molten metal in the vertical casting apparatus of this invention. It is explanatory drawing which shows the operation state in the vertical casting apparatus of this invention following FIG. It is a metal mold | die schematic longitudinal cross-sectional view when the vertical casting apparatus of this invention is applied to aluminum wheel production. It is a schematic longitudinal cross-sectional view of the vertical casting apparatus which concerns on the other example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed mold 2 Movable mold 3 Fixed platen 4 Movable platen 6 Pouring pot (gas pressurizing pouring pot)
7, 16 Molten metal 8 Molten metal surface 8a Molten metal surface of hot water supply pipe 9 Mold cavity 10 Circular gate 11 Cavity first hot water reservoir 12 Side gate 13 Blocking pin 14 Pressure stem 15 Jet 17 Pressure gap for molten metal coagulation zone 18 Pressure stem gas discharge gap 19 Cavity second hot water reservoir 20 Pressure pin 21 Pressure pin molten metal solidification zone gap 22 Pressure pin outer periphery gas discharge gap 23 Pressure stem piston 24 Closure pin piston 25 Hydraulic cylinders 26a, 26b , 26c Pressure oil inlet 27 Pressure stem Seal packing 28 Closure pin Seal packing 29 Pressure stem Gas discharge passage 30 Pressure pin Piston 31 Pressure pin hydraulic cylinder 32 Pressure oil inlet 33 Pressure pin Seal packing 34 Pressure pin Gas discharge Passage 35 Mold seal groove 36 Pressure stem cooling water hole 37 Pressure pin Cooling water hole 38 Hot water pot seal packing 39 Stoke seal packing 40 Cast stalk 41 Pressurized gas inlet 42 Hot water ladle 43 Outer peripheral type 44 Molten metal supply pipe 45 Hot water inlet sleeve 46 Hot water inlet 47 Hot water outlet lid 48 Hot water inlet gas section 49 Gas outlet inlet 9a Aluminum wheel hub part 9b Aluminum wheel spoke part 9c Aluminum wheel rim flange part

  The present invention is a vertical casting apparatus capable of casting a cast product such as an aluminum alloy from below, and filling the mold cavities with molten metal from below. The present invention relates to a vertical casting apparatus for supplying and filling and a vertical casting method using the same.

  When casting a cast product such as a light alloy product, particularly a part that requires strength, a vertical casting apparatus is used to prevent gas entrainment during casting of the molten metal.

  In such vertical casting apparatuses, it is already known to use low-pressure gas as means for supplying molten metal from the molten metal holding furnace to the mold cavities while preventing the mixing of oxides and gas entrainment. (See JP 58-55166 A). However, the low-pressure gas is effective for quantitatively supplying the molten metal to the mold, but simply using the low-pressure gas has a low casting speed and a low pressure. It was not possible to prevent or sufficiently respond to thin-walled products. Further, in the conventional apparatus, a large amount of molten metal is accommodated in a molten metal holding furnace fixed to the apparatus main body, and the apparatus is enlarged. Furthermore, it is not easy to replenish the molten metal in the molten metal holding furnace fixed to the apparatus main body, and it is very difficult to perform a spraying operation for cleaning or lubricating the inflow gate of the apparatus main body.

In addition, one of the inventors of the present invention invented a method using an immersion type electromagnetic pump as a means for supplying molten metal to a mold cavity (see Japanese Patent Application Laid-Open No. 2003-266168). In order to cope with this problem, the electromagnetic pump becomes larger and the apparatus becomes larger, making it difficult to put it to practical use.
JP 58-55166 A JP 2003-266168 A

  In casting by a vertical casting apparatus, in order to cast a high-quality casting product, particularly a thin-walled and large-sized casting product, it is necessary to fill the mold cavity with molten metal at a high speed. Also, in order to prevent the inclusion of oxides and gas entrainment that cause defective defects in castings, and to prevent shrinkage caused by solidification shrinkage, it is effective to fill the molten metal from below and use a sufficient amount of molten metal. It is necessary to replenish with pressure. At that time, in order to reduce trouble during operation, it is necessary to simplify the structure of the cavity and the structure of the entire casting apparatus. Work efficiency and ease of maintenance are also very important factors.

  An object of the present invention is to fill a mold cavity with molten metal at high speed, and effectively pressurize the molten metal in the closed cavity, thereby easily casting a cast product without generation of sink marks and without entrainment of gas. It is an object of the present invention to provide a vertical casting apparatus that has high working efficiency and is easy to maintain and has a low equipment cost, and a vertical casting method using the vertical casting apparatus.

  The present inventors have intensively studied to solve the above-mentioned problems, and by using a gas pressurized hot pot that can be attached / detached with the apparatus main body, it is possible to obtain a vertical casting apparatus that has high work efficiency and is easy to maintain and has low equipment costs. It is possible to supply the molten metal at a high speed by increasing the gas pressure of the gas pressurized hot water pan, and to find that it is possible to cast a cast product with no oxide film mixing and gas entrainment, The present invention has been completed. Furthermore, after the cast molten metal is filled in the cavity, if the molten metal in such a closed state is effectively pressurized by shortening the pressure transmission distance at a plurality of locations, there is no generation of shrinkage and the inclusion of oxide film and gas. The present inventors have found that it is possible to cast a cast product that does not involve winding, and have completed the present invention.

  That is, the present invention includes (1) a lower fixed mold and an upper movable mold capable of forming a mold cavity, a closing means for closing a molten metal inflow gate formed in the fixed mold, and a closed mold. A vertical casting apparatus comprising an apparatus main body having a pressurizing means for pressurizing a molten metal in a mold cavity, and casting means for supplying and filling the molten metal into the mold cavity from below, wherein the casting means is A gas pressurized pouring pan that can be attached to and detached from the apparatus main body, and that is attached to and detached from the apparatus main body, and the capacity of the gas pressurized pouring pot is a capacity that accommodates the molten metal required for one casting. (2) A vertical casting apparatus as described in (1) above, wherein a sealed structure is formed by attaching a gas pressurized pouring pan to the apparatus main body, 3) The gas pressurized pouring pan has cast stalk, The vertical casting apparatus according to the above (1) or (2), wherein the upper end portion of the cast stalk is brought into close contact with the apparatus main body, and (4) the apparatus main body performs the casting stalk. A vertical casting apparatus according to the above (1) or (2), or (5) a gas pressurized hot water pouring pan, wherein an upper end portion of the gas pressurized hot pouring pot is brought into close contact with the apparatus main body to form a sealed structure Is provided with a heating means, and relates to the vertical casting apparatus according to any one of (1) to (4).

The present invention also includes ( 6 ) a lower fixed mold and an upper movable mold capable of forming a mold cavity, a closing means for closing a molten metal inflow gate formed in the fixed mold, and An apparatus main body having a pressurizing means for pressurizing the molten metal in the mold cavity, and a casting means having a gas pressurizing pouring pot that can be attached to and detached from the apparatus main body to supply and fill the molten metal into the mold cavity from below. Using a vertical casting apparatus equipped with a slag, the molten metal is cast into the mold cavities from the gas pressurized pouring pan through casting stalk, and after the molten metal fills the cavities, the molten metal inflow gate formed in the fixed mold is closed. And then pressurizing the molten metal in the mold cavity with the pressurizing means, and after closing the molten metal inflow gate with the closing means, immediately releases the gas pressure in the gas pressurized molten metal pan to the atmosphere. To desorb from Okimoto body, supplying molten metal required for the next to the gas press-welding Yunabe, wearing again the apparatus body, it or vertical casting method according to claim comprising the next casting (7) Gas The vertical casting method as described in ( 6 ) above, wherein the gas pressure in the pressurized pouring pan is adjusted to 1 kg / cm ² or more and cast in a short time at a high speed, and ( 8 ) The present invention relates to the vertical casting method according to ( 6 ) or ( 7 ), wherein the casting is a light metal alloy thin-walled and large-sized casting.

  The vertical casting apparatus of the present invention includes a lower fixed mold and an upper movable mold capable of forming a mold cavity, a closing means for closing a molten metal inflow gate formed in the fixed mold, and a closed mold. A vertical casting apparatus comprising an apparatus main body having pressurizing means for pressurizing the molten metal in the mold cavity, and casting means for supplying and filling the molten metal into the mold cavity from below, wherein the casting The means is not particularly limited as long as it has a gas pressurized pouring pan that can be attached to and detached from the apparatus main body, and the vertical casting apparatus of the present invention has a high work efficiency and a low maintenance cost. When the vertical casting apparatus of the present invention is used together with the mold casting apparatus, it is possible to suitably cast a cast product that does not generate a shrinkage nest at the time of solidification and that does not involve gas, particularly a thin and large cast product. Can do. And although it does not specifically limit as this casting, A light metal alloy, especially an aluminum alloy with a large solidification shrinkage are preferable. Since aluminum shrinks by about 7% when solidified, the casting apparatus and casting method of the present invention, which can prevent the formation of shrinkage nests, are particularly thin and large-sized from molten metal made of light metal alloy such as aluminum alloy that has large solidification shrinkage. The present invention can be applied particularly advantageously when casting a cast product.

  The gas pressurizing pouring pot in the casting means is not particularly limited as long as it is a pouring pan capable of gas pressurization and can be attached to and detached from the apparatus main body. The gas pressurized hot water pot needs to have a sealed structure, but for example, a gas pressurized hot water pot with an open top can be provided with a lid, but the sealed structure can be formed by attaching it to the device body. It is preferable to do. As a configuration for forming a sealed structure by mounting on the apparatus main body, when the gas pressurized pouring pan has a cast stalk, the upper end of the cast stalk is brought into close contact with the apparatus main body to form a sealed structure. Specifically, for example, the upper surface of the stalk can be pressed against the lower surface of the gate entrance of the mold to form a sealed structure. In addition, when the apparatus main body is equipped with cast stalk, the upper end of the gas pressurized pouring pan can be brought into close contact with the apparatus main body to form a sealed structure. Specifically, for example, the upper surface of the gas pressurized pouring pan Can be pressed against the lower surface of the fixed plate to form a sealed structure, or can be pushed into a seal packing provided at the lower portion of the fixed plate of the fixed mold to form a sealed structure. At this time, it is preferable to make the upper part of the gas pressurized hot water pot smaller than the lower part and make it easy to seal the apparatus body.

  In this way, by using a gas pressurized pouring pan that can be attached to and detached from the apparatus main body, the molten metal can be introduced from, for example, a hot water ladle from above (opened) the gas pressurized pouring pan that has been detached (removed). The molten metal can be replenished very easily. Moreover, since the gas pressurization pouring pan can be removed and the inflow gate of the apparatus main body can be cleaned and sprayed for lubrication, it is very easy to perform maintenance.

  The gas pressurized hot water pouring pan may be provided with a molten metal supply pipe (a molten metal supply passage) communicated with an opening provided at a lower portion thereof. An openable and closable hot water supply lid with a durable sealing force is provided. Here, the lower part of the gas pressurized hot pot provided with an opening means a part below the molten metal surface in the molten metal pot (when full), can cast the molten metal more efficiently, and Since the molten metal can be more efficiently dropped from the stalk, it is preferably a portion below the lower end of the cast stalk. In this case, it is not always necessary to remove and move the gas pressurized molten metal pan during hot water supply, but when removing and supplying hot water, the moving distance can be shortened and the work can be performed more efficiently.

  Such a pressurized gas pouring pan is preferably provided with a heating means, whereby it is possible to suppress the generation of a solidified layer and to suppress the occurrence of defects in the cast product as much as possible due to good hot water circulation.

  Moreover, as a capacity | capacitance of a gas pressurization pouring pot, it is a capacity | capacitance which can accommodate the molten metal required, for example for 1-3 times of casting from the point of prevention of the enlargement of an apparatus and the ease of conveyance of a gas pressurization pouring pot. It is more preferable that the capacity is enough to accommodate the molten metal required for one casting. By making the capacity to accommodate the molten metal required for one casting, the amount of molten metal in the pouring pan at the time of each casting is always constant, so there is no need for pressure correction, and continuous filling is performed more simply. In addition, it is possible to suppress the mixing of oxides and entrainment of gas and to perform stable operation. That is, in the case of the capacity for multiple times, the liquid level at the time of each casting is different, and it is necessary to finely adjust the pressure, but by making the capacity that can accommodate the molten metal required for one casting There is no need to make such subtle adjustments.

  In addition, the downsizing of such gas pressurized pouring pans enables the gas pressure to be increased because the surface of the hot metal is raised and the volume of the gas part is reduced, and the quantitative supply of molten metal to the mold cavity is possible. In addition, the supply speed can be increased and the shot time lag can be shortened, and high-quality casting and casting of a large-sized cast product with a thin wall can be performed. Furthermore, by using such a pouring pan, the production cycle time is shortened, so that the productivity is improved.

  Moreover, it is preferable that the casting means has a vacuum suction mechanism that vacuum-sucks and fills the molten metal in the gas pressurization pouring pan by vacuuming the gas in the mold cavity in addition to the gas pressurization pouring pan. As a result, the mold cavity can be filled with the molten metal at a high speed, and the gas in the mold cavity can be discharged to prevent the gas from being entrained. This vacuum suction can be performed through a gas discharge passage which will be described later.

  As the mold cavities, mold cavities capable of casting a thin and large cast product are preferable. The mold cavities include a cavity product portion and a cavity hot water reservoir, and the cavity hot water reservoir is located above the molten metal inflow gate. It is more preferable to include a cavity first hot water reservoir, and one or more cavity second hot water reservoirs located near the end of the cavity product product portion on the side opposite to the cavity first hot water reservoir. And a cavity product part and a cavity 1st hot water reservoir communicate with each other via a side gate, and the cavity first hot water reservoir preferably has a larger volume than a cavity 2nd hot water reservoir. .

  The lower fixed mold is formed with a communicating portion between a casting stalk for filling and supplying molten metal from a lower pouring pot and a cavity first hot water reservoir portion, and a molten metal inflow gate is provided in the communicating portion. ing. The shape of the molten metal inflow gate is not particularly limited. However, in view of ease of processing or the like, a shape having a circular cross section is usually preferable. In this case, the inner diameter of the circular molten metal inflow gate is configured to be smaller than the inner diameter of the stalk. It is preferable to keep it. By configuring in this way, the molten metal filled and supplied from below can be ejected into the cavity first hot water reservoir, and, as will be described later, the molten metal is poured into the stalk that contributes to the defective casting product. It is possible to prevent the oxide film on the surface of the molten metal or the chill layer (solidified layer) generated by cooling on the inner surface of the stalk from entering the product.

  The closing means for closing the molten metal inflow gate formed in the fixed mold may be any means as long as it has a mechanism capable of closing the molten metal inflow gate. For example, the circular molten metal inflow gate can be opened and closed. In this case, the diameter of the insertion portion of the closing pin into the circular molten metal inflow gate is made slightly smaller than the inner diameter of the circular molten metal inflow gate. It is preferable from the viewpoint of occlusion and sealing. It is preferable to hold the closing pin so that it can move forward and backward in a liquid-tight manner with respect to the movable mold. In the case of being held slidably densely, a closing pin can be provided coaxially and slidably in a liquid-tight manner at the center of the pressure stem.

As described above, when the pressurizing stem and the closing pin are disposed in the movable mold above the circular molten metal inflow gate, the circular cavity first hot water reservoir portion formed in a state in which they are retracted (raised). The diameter of the inlet is made larger than 1.4 times the diameter of the circular molten metal inflow gate, and the ceiling height of the hot water reservoir at the upper limit of the pressure stem and the closing pin is ejected from the circular molten metal inflow gate. It is preferable that the cavity first hot water reservoir is configured to be 10 mm or more higher than the height of the molten metal jet. Thus, when the diameter of the inlet of the hot water reservoir is 1.4 times or more the diameter of the circular gate, the height h of the molten metal jet is approximately v for the passage speed of the molten metal in the circular gate and g for the acceleration of gravity. when a, h = v ² / since 2g can be determined by the equation, when a faster rate of v = 2.0 m / sec the casting speed in the general range, ejection height h = 2. 0 ² /2g=0.204 mm

  In other words, if the ceiling height is set to 204 + 10 = 214 mm, the jet flow does not collide with the ceiling, the free surface is formed, the oxide film on the molten metal surface is confined without backflow, and gas entrainment due to the collision is also possible. Can be prevented.

  For example, the pouring / filling speed of the molten metal varies depending on the shape of the product, but generally the initial passing speed in the circular gate is preferably 1.0 to 2.4 m / sec. The height is usually about 50 to 300 mm, but when the height of the ceiling of the first cavern is higher than the height of the molten metal jet by 10 mm or more, a free surface was formed and remained on the hot water surface. The oxide film also remains on the surface, and the gas remaining in the upper part of the hot water reservoir is still contained and does not flow downward. There is no gas involved. On the other hand, if the jet velocity is low, it will not collide with the ceiling and there will be no gas entrainment, but the casting time will be longer, the speed at which the molten metal will flow through the cavity product will become slower, and cooling solidification will progress during this time, resistance Increases, the flow velocity further decreases, and the molten product is insufficiently filled in the cavity product part, and even if the pressure is applied, the pressure transmission is poor and the possibility of occurrence of shrinkage increases. Therefore, when the molten metal fills the first hot water reservoir and begins to enter the product section, it is preferable to increase the gas pressure in the pouring pan and adjust the casting speed so that the casting speed is as fast as possible. At this time, the first hot water reservoir is filled with molten metal, and this acts as a resistance so that the flow of the inflow gate does not entrap the oxide film or gas remaining on the ceiling.

  When supplying the molten metal with high-pressure gas, the casting speed is increased and the molten metal is less cooled and solidified in the cavity, and the driving force can fill the molten product into a narrow part of the cavity product part with high resistance. Even if the filling is insufficient, there is no problem because the volume is small and the filling can be performed by sufficient pressurization such as a pressure stem.

  As described above, when the cavity first hot water reservoir is formed in the cavity, the oxide film and the gas entrainment layer present at the uppermost portion of the hot water reservoir when the closing pin and the pressure stem are advanced (lowered). Stays at the upper end of the cavity first hot water reservoir without being extruded, and does not enter the cavity product section. Also, in the case of casting using a pouring pan, the Stoke pouring spout is under the surface of the pouring pan, and the oxide film generated on the pouring surface floats on the surface of the pouring pan, so it is not possible to enter Stoke Absent. The slight oxide film on the surface of the stalk inner bath is at the tip of the jet and completely jumps into the first reservoir of the cavity and does not flow out to the cavity product section through the side gate, but the oxide film is mixed into the cast product. This eliminates defects in cast products and variations in strength.

  Next, by pressurizing the molten metal filled in the closed mold cavity, it is possible to cast a cast product in which no shrinkage occurs during solidification and gas is not entrained by a jet. As a pressurizing means for pressurizing the molten metal in the closed mold cavity, it is slidably provided on the movable mold above the first hot water reservoir of the cavity, and a closing pin is slidable in the center. The pressurizing stem provided and the cavity first hot water reservoir are slidably disposed on the movable mold above the cavity second hot water reservoir located at a position separated from the cavity product portion. A pressure pin can be specifically exemplified. It is preferable to provide a plurality of pressure pins. The diameter is preferably 2/3 to 1 times the depth of the cavity second hot water reservoir. Further, these pressure stems and pressure pins are preferably used in combination. In this way, by pressurizing the molten metal from the pressure stem and the plurality of pressure pins located at separate positions, the pressure transmission distance to the molten metal in the cavity is shortened, so that the pressure is uniformly transmitted to the cavity product part. Therefore, it is possible to cast a cast product in which no shrinkage occurs during solidification with a small pressure. In addition, the pressure transmission distance of the molten metal in the cavity product part is further shortened by arranging the pressure stem and the pressure pin at appropriate positions according to the form of the product, and the pressure transmission is made more uniform and sufficient. In addition, it is possible to prevent the formation of a shrinkage nest with a smaller pressure.

  In conventional casting apparatuses, in general, in order to cast a cast product in which no shrinkage occurs during solidification, the pressurizing means of the molten metal by the pressurizing means is increased and rapidly pressurized. In this case, the pressure transmission is too good, the mold opening force is increased, the burr is blown, and the mold clamping force must be increased. However, if the pressurization rate is slowed down, it will not catch up with the solidification shrinkage of the molten metal, and a sinkhole will be generated. On the other hand, according to the present invention, uniform and sufficient pressure transmission can be performed even with a small mold clamping force that can prevent burrs from being blown. it can. As described above, in the present invention, the pressurization speed is controlled by performing program control so that the advancement speed of the pressurization stem and pressurization pin during pressurization becomes a speed adapted to the solidification contraction speed of the molten metal in the cavity product part. By adjusting it, it is possible to prevent the formation of sink marks while preventing burrs from being blown with a press device with a small clamping force. For example, the pressure and pressurizing speed for the molten metal during solidification shrinkage where Pascal's principle does not work Is controlled in accordance with the solidification rate within the range where burrs are not blown, so that a device with a small clamping force of 1/3 to 1/5 of the conventional high pressure method can be used. It is possible to obtain a cast product having a dense structure without gas entrainment.

  In addition, in the case of vertical casting methods such as squeeze casting, if the pressure applied by the acurad pin (center pin) is accelerated, the casting plunger will be pushed down. Since pressure is applied after the pressure transmission to the plunger is reduced, solidification of the molten metal in the cavity progresses during that time, and a large pressure is required for replenishing the molten metal. However, in the present invention, since the present invention is provided with a means for closing the molten metal inflow gate, it is possible to replenish and fill the molten metal by pressurizing from the stage where solidification is still progressing immediately after the closed gate. In addition, since the pressure is applied by the pressure stem and a plurality of pressure pins arranged at predetermined positions, the pressure transmission distance is short, and the pressure is uniform and charged with a small pressure. It can be performed Do refill packing. As a result of the pressure being reduced in this way, the mold clamping force of the mold can be reduced, and the costs of the mold clamping device and the mold can be kept low. In addition, this casting speed and pressurization start speed are faster than squeeze casting, thin wall casting is also possible, good heat transfer is maintained by maintaining contact with the mold surface of the molten metal, cooling time is short, crystal The quality is improved, the production cycle time is shortened, and the productivity is improved.

  Further, in the vertical casting apparatus of the present invention, a gas discharge passage capable of discharging the gas existing in the cavity when the molten metal is filled in the mold cavity, and a gap for the molten metal solidification zone communicated with the gas discharge passage. Those having the following are preferred. The gas discharge passage is preferably configured by a gas discharge hole penetrating through the movable mold and a gas discharge gap. The molten metal solidification zone gap is preferably provided in the vicinity of the gas discharge passage, and particularly preferably close to the pressurizing means. As the gap for the molten metal solidification zone, for example, after discharging the gas in the cavity from the gas discharge passage, the molten metal can be solidified in the gap that becomes the molten metal solidification zone. Any air gap can be used as long as it can seal and close the inside of the cavity, and simply by providing such a gap for the molten metal solidification zone, an air vent valve, a filter, etc. are provided and a complicated switching valve or The inside of the cavities can be easily sealed and closed without using a valve, and there is no need for complicated operations such as pressure adjustment when the casting apparatus is in operation. The device can be said to be very practical. Further, the area of the docking surface between the upper surface of the stalk and the lower surface of the mold, or the upper surface of the pouring pan and the lower surface of the fixed platen is small, and a pressure seal for preventing pressurized gas from leaking during pouring can be easily achieved.

Specifically, the molten metal solidification zone gap communicates with the gas discharge passage through a gas discharge gap formed between the outer peripheral surface of the pressure stem and / or the pressure pin and the inner peripheral surface of the movable mold. to have can be exemplified an air gap for molten metal solidification zone, as such molten metal solidification zone void, provided the pressure stem / or pressure pin coaxial with, than the diameter of the pressing stem and / or the pressure pin In addition, a gap that becomes a molten metal solidification zone having an inner diameter larger by 1 to 5 mm and a depth (length) of about 10 to 40 mm can be specifically exemplified. In this way, by setting the outer diameter of each hot water pool portion to be slightly larger than the outer shape of the pressure stem and the pressure pin, the solidified layer formed on the outer peripheral wall of each hot water pool portion can be increased by the pressure stem / While being pushed into the product by the pressure pin, the pressure resistance of the pressure stem and the pressure pin can be reduced. As described above, when the gap for the molten metal solidification zone is designed to have a size that matches the temperature of the molten metal and the casting speed, the hot water is cooled and solidified in the gap when the molten metal is filled. Never invade.

  Further, the gas discharge gap preferably has a structure or size that does not allow the hot water to flow in. For example, the gas discharge gap is provided concentrically with the pressure stem and / or the pressure pin, and the pressure stem and / or A gas discharge gap having an inner diameter that is about 0.4 to 1.0 mm larger than the diameter of the pressure pin can be specifically mentioned. When the mold cavity is evacuated, in order to prevent intrusion of air, the parting surface is not provided with gas discharge holes and gas discharge passages. A gas exhaust groove connected to the gas exhaust port is provided to prevent air from leaking into the mold cavity from outside the mold.

  By the way, if the casting start speed of the molten metal by the combined use of the gas pressurized pouring pan and the vacuum suction mechanism is set to an optimum value of 1.0 to 2.4 m / sec, the molten metal provided close to the outer periphery of the pressure stem and the pressure pin. The air resistance in the two-stage gaps such as the solidification zone gap and the gas discharge gap is increased, but the purpose of installing the molten metal solidification zone gap and the gas discharge gap by appropriately selecting the number and arrangement of the pressure pins. Can be achieved. That is, those skilled in the art can easily design a structure in which the hot water is cooled and solidified in the melt solidification zone gap having a two-stage gap and does not enter the gas discharge gap narrower than the melt solidification zone gap. Also, in order to cool and solidify the hot water in the gap for the molten metal solidification zone, a material with good heat conduction, such as beryllium copper, is used for the pressure stem and pressure pin, and the inside can be cooled with water. You can also.

  As described above, in the vertical casting apparatus of the present invention described above, the structure of the gas discharge system around the pressure stem and the pressure pin is simple, and the occurrence of trouble during operation is reduced. In addition, by combining gas pressurization and a vacuum suction mechanism in a sealed small-volume pouring pan, it is possible to cast a large thin product by filling the mold cavity at high speed, The hot water flows into the narrow molten metal solidification zone gap, so that it solidifies and stops there and does not enter the gas discharge gap passage. In addition, by increasing the depth of the cavity 1st hot water reservoir, the stroke of the pressurization stem can be lengthened, and a sufficient volume of molten metal for refilling and coagulation shrinkage in the cavity product part can be obtained. In addition, it is possible to obtain a strong casting with a denser structure by adding pressure to reduce the crystal by increasing the cooling rate. In addition, the circular gate is closed with a closing pin slightly smaller than the inner diameter of the circular gate, the gas pressure in the pouring pan is released to the atmosphere, and the molten metal in the stalk is quickly returned to the pouring pan by lowering it quickly. Prevents troubles caused by solidification.

  In addition, when the mold is opened, the pouring pan is taken out of the machine so that the inflow gate can be cleaned, and the mold surface can be cooled and lubricated easily and safely.

  In addition, in the casting apparatus of the present invention equipped with a pressurized gas pouring pan and a vacuum suction mechanism, when filling molten metal into the mold cavity, the gas in the cavity is almost completely discharged, and at the same time, the circular gate is closed after filling. Therefore, the necessary and sufficient pressure can be applied with a small pressure, so it can be handled with a clamping force of 1/3 to 1/5 that of the conventional high pressure method, and the cost of the casting apparatus is greatly reduced, and the productivity is also high. Since it is good, the cost of the casting can be greatly reduced. In addition, since the molten metal is supplied directly from the bottom of the pouring pan, the oxide film is not mixed in, and the passage is short, so there is little generation of a solidified layer, and the cavity has an appropriate height at the exit of the circular gate. By providing the first hot water reservoir, the jet flow does not collide with the ceiling, gas entrainment can be eliminated, and a slight remaining oxide film or solidified layer can be retained in the cavity first hot water reservoir. As a result, a cast product having a dense structure free of impurities can be obtained. Furthermore, as the hot pot is small and the gas pressure can be increased, a high casting speed can be secured, thin-wall casting becomes possible, and by moving the hot pot, it is easy to replenish the molten metal and the equipment cost is reduced. In addition, the arrangement and operation of the apparatus become easy.

Further, the vertical casting method of the present invention is a casting method using the vertical casting apparatus, in which the molten metal is cast into the mold cavity through the casting stalk from the gas pressure pouring pot, and the molten metal fills the cavity. After that, it is not particularly limited as long as it is a vertical casting method in which the molten metal inflow gate formed in the fixed mold is closed by the closing means, and then the molten metal in the mold cavities is pressed by the pressing means. The top of the gas pressurized pouring pan that has received the molten metal for the amount of pouring once or more is pushed into the seal packing provided at the bottom of the fixed plate and sealed, and a gas pressure of 1 kg / cm ² or more is preferably applied to the pouring pan. Pressurize the hot water surface in the hot pot and cast the molten metal into the mold cavity through casting stalk. At this time, when the gas pressurized pouring pan has a molten metal supply pipe, the same gas pressure may be simultaneously applied from above the molten metal surface of the supply pipe. Subsequently, after filling the cavity with molten metal, the molten metal inflow gate provided in the fixed mold is closed with a closing means, and then the molten metal in the mold cavity is pressurized with a pressure means (pressure pin), A cast product in which no shrinkage occurs at the time of solidification and no gas is entrained, preferably a thin and large cast product of a light metal alloy is cast.

  At the retreat position of the pressure pin, the filling of the molten metal into the mold cavities is started, the flow rate of the hot water is decelerated at the cavity second hot water reservoir, and the gas in the mold cavities is discharged from the gas discharge gap. It is preferable that the molten metal solidification zone gap is cooled and solidified, and after the molten metal is filled in the mold cavity, the molten metal in the hot water reservoir is pressurized by advancing one or more pressure pins. The pressure transfer distance by reducing the gas entrainment by performing vacuum degassing from the gas discharge gaps adjacent to the plurality of molten metal solidification zones and pressurizing the molten metal with a pressure stem and a plurality of pressure pins Is preferably shortened. By this replenishment filling, the contact of the molten metal with the mold surface is maintained, good heat transfer is maintained, the cooling rate is high, the coarsening of the crystal is prevented, and a small crystal structure is formed. When the molten metal is solidified and replenishment filling is completed, the movable mold is raised by the movable platen after a short cooling time, and the product material lifted together with the movable mold is moved by the pressure stem, the pressure pin and the extrusion pin. Then, by extruding with a push pin and then withdrawing from the pressure stem and the pressure pin and taking out the product material, a cast product with a dense structure can be obtained without generation of shrinkage and gas entrainment. In addition, in order to repeat this operation every time, the molten metal in the gap for the molten metal solidification zone is removed every time, and the gas discharge passage is not clogged, and the stalk upper surface and the lower surface of the mold of the mobile gas pressurized hot water pan When sealing by pressing, the contact area is small and sealing is easy.

  Although it is possible to work efficiently by casting using a plurality of gas pressurized pouring pots, the gas pressure in the gas pressurized molten pot is immediately released to the atmosphere after the molten metal inflow gate is closed by the closing means. At the same time, it is preferable to detach from the apparatus main body, supply the necessary molten metal for the next time, and attach it again to the apparatus main body to prepare for the next casting. Thereby, it can cast very efficiently using one gas pressurization pouring pot. In addition, when using a gas pressurized pouring pan equipped with a molten metal supply pipe, the gas in the pouring pan is released to the atmosphere, and the molten metal supply pipe is covered with or without detaching the molten metal pot from the apparatus body. Open and supply the next molten metal. After closing the molten metal inflow gate with the closing means, the gas in the pouring pan is released to the atmosphere and the gas in the hot water supply port of the molten metal supply pipe is sucked up to raise the molten metal surface in the molten metal supply pipe. By designing the surface so as to be pulled down to the lower end of the stalk, the molten metal in the stalk can be dropped more quickly, thereby making it possible to work more efficiently.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, the technical scope of this invention is not limited to these illustrations.

  1 is a schematic longitudinal sectional view of the vertical casting apparatus of the present invention (at the start of pouring), FIG. 2 is a schematic longitudinal sectional view of the vertical casting apparatus of the present invention (at the time of hot water supply), and FIG. A sectional view, FIG. 4 is explanatory drawing which shows the pushing-up state of a molten metal, FIG. 5 is explanatory drawing which shows the operation | movement state following FIG. 1 to 5, 1 is a fixed mold, 2 is a movable mold, 9 is a cavity product section, 10 is a circular gate, 11 is a cavity first reservoir, 13 is a closing pin, and 14 is a pressure stem. , 17 is a molten metal solidification zone gap (pressure stem outer periphery), 19 is a cavity second hot water reservoir, 20 is a pressure pin, 21 is a molten metal solidification zone gap (pressure pin outer periphery), and 29 is a pressurized stem gas discharge. The hole 34 is a pressurized pin gas discharge hole, 40 is a casting stalk, and 41 is a pressurized gas inlet.

  The casting apparatus of the present invention shown in FIGS. 1 to 5 is capable of moving up and down to perform mold closing, and a fixed mold 1 attached to a horizontal fixed platen 3 at the bottom of the casting apparatus, and casting. A movable mold 2 attached to a horizontal movable platen 4 at the upper part of the apparatus and a gas pressurized hot water pan 6 positioned below the fixed platen 3 are provided. By opening and closing the fixed mold 1 and the movable mold 2, the cavity product portion 9, the cavity first hot water reservoir portion 11, the cavity second hot water reservoir portion 19, the cavity product portion 9 and the cavity first hot water reservoir portion 11. A mold cavity having a side gate 12 that communicates with each other is formed. In addition, the mold is mounted by mounting a mold set including the fixed mold 1 and the movable mold 2 to which the cast stalk 40 is attached in a state in which the movable platen 4 of the mold clamping press device (not shown) is pulled up. Then, the movable platen 4 is lowered until it contacts the upper surface of the movable mold 2, and the fixed mold 1 is attached to the fixed platen 3 and the movable mold 2 is attached to the movable platen 4. The gas pressurized hot water pouring pan 6 is hermetically sealed by pushing its upper end into a seal packing 38 provided at the lower part of the fixed platen 3.

  The fixed mold 1 is provided with a cast stalk 40 that extends downward at a lower portion thereof, and a circular gate 10 for ejecting molten metal from the cast stalk 40. When the pressurized gas is fed from the pressurized gas inlet 41 and the inside of the cavity is depressurized, the molten metal 7 in the pouring pan 6 is pushed up in the casting stalk 40, and the cavity product is passed through the circular gate 10 of the fixed mold 1. The portion 9 is filled. The casting speed at this time is controlled by adjusting the gas pressure in the pouring pan 6 and the degree of vacuum in the cavity so that the passing speed of the circular gate 10 of the molten metal becomes a jet and jets upward. Has been.

In addition, as shown in FIG. 4, the inlet diameter d ₁ of the cavity first hot water reservoir 11 is configured to be 1.4 times or more the diameter of the circular gate 10, and the outer diameter ds of the pressurizing stem 14 is the hot water reservoir 11. velocity h = v ² / 2g (wherein h is the jet reaches the height, v is the circular gate passage; a is configured slightly smaller than the inlet diameter d _1, further cavity ceiling height of the first the basin are as defined in formula , G indicates the acceleration of gravity.) And is configured to be higher than the height h at which the molten metal jet 15 passing through the circular gate 10 reaches. Accordingly, in the initial stage of filling, the jet does not form the ceiling of the cavity first hot water reservoir 11, and the free surface of the molten metal jet 15 is formed on the upper part, and the downward flow of this part disappears, so that the oxidation remaining slightly on the molten metal surface The film remains stationary, and the gas remaining on the upper part of the hot water reservoir 11 is not entrained in the molten metal 16. As a result, a slight oxide film and gas winding at the tip of the molten metal jet 15 passing through the circular gate 10 are obtained. The entrainment layer remains on the ceiling, and after the molten metal is filled in the hot water reservoir 11, the flow does not reach the ceiling even if the casting speed is increased, and only the oxide film and clean molten metal without gas entrainment are on the side. The cavity product portion 9 is filled through the gate 12.

  In addition, a hydraulic cylinder 25 is disposed in a liquid-tight manner on the movable mold 2 above the circular gate 10 via a seal packing 27, and a pressurizing stem 14 is attached to the hydraulic cylinder 25 by a hydraulic pressure. A pressurizing stem piston 23 that can be moved back and forth to the hot water reservoir 11 is housed via a seal packing 27, and the pressurizing stem piston 23 is provided with a closing pin 13 that can close the circular gate 10. A closing piston 24 that can be advanced and retracted is accommodated coaxially with the pressurizing stem piston 23. After filling the mold cavity with the molten metal, the closing pin 13 is advanced by the piston 24, the circular gate 10 is closed, and then the pressure stem 14 is advanced by the piston 23, and the cavity product part 9 is not yet filled. The molten metal for the void volume and the solidification shrinkage volume is pressurized and supplied from the cavity first hot water reservoir 11. At that time, since the stroke of the pressure stem 14 is large, a sufficient amount of molten metal can be replenished and pressure-filled.

  Even during pressurization by the pressurization stem 14, an oxide film slightly generated on the molten metal surface in the stalk, a solidified layer on the molten metal surface formed by cooling at the inlet of the circular gate 10, and gas entrainment generated by a jet flow All the layers gather at the uppermost part of the hot water reservoir 11 by the gate jet 15, remain on the upper part of the cavity first hot water reservoir 11 without being pushed out by the pressure stem 14, and flow into the cavity product portion 9. As a result, there is no casting defect caused by these. Further, on the outside of the pressurization stem 14, a two-stage gap including a gas discharge gap 18 communicating with the gas discharge hole 29 and a molten metal solidification zone gap 17 is provided. As shown in FIG. 5d, the molten metal solidification zone gap 17 and the gas discharge gap 18 are taken out together with the product material since the solidified layer formed by the molten metal solidification zone gap 17 and the gas discharge gap 18 is removed. Secured.

  As shown in FIGS. 1 and 2, one or two or more small cavity second hot water reservoirs 19 are formed above the end of the cavity product portion 9, and above the hot water reservoir 19. A hydraulic cylinder 31 is disposed in the movable mold, and a pressure pin piston 30 capable of advancing and retracting the pressure pin 20 to and from the cavity second hot water reservoir 19 by hydraulic pressure is accommodated in the hydraulic cylinder. ing. The one or more pressure pins 20 have an axial core parallel to the mold opening / closing direction and perpendicular to the mold parting surface, and are liquid-tightly provided on the movable mold 2 via a seal packing 33. Then, after replenishing and filling the cavity product part 9 by the pressurization stem 14, these pressurizing pins 20 are extruded, and the molten metal in the cavity product part 9 is pressurized via the cavity second hot water reservoir 19. ing. Further, the outer diameter of the pressure pin 20 is configured to be slightly smaller than the diameter of the inlet of the cavity second hot water reservoir 19. Since these pressurizing pins 20 also slide each time, the solidified layer formed by the molten metal solidification zone gap 21 is pushed out by an extruding pin (not shown) attached to the product material and does not remain in the gas passage hole, but the gas discharge passage every time. Is to be secured.

  Next, the operation of the vertical casting apparatus described above will be described. After the mold clamping is completed, the molten metal 16 in the pouring pan 6 is pushed up to the cavity first hot water reservoir 11 by the pressure of the pressurized gas fed into the gas pressurized hot pouring pan 6 and the vacuum suction force into the cavity. The molten metal 16 ascends in the casting stalk 40, passes through the circular gate 10 of the fixed mold 1, and is ejected (FIG. 4). In general, since there is a flow resistance in the cavity product portion 9, before the molten metal reaches the cavity second hot water reservoir 19 below the pressurizing pin, the cavity first hot water reservoir 11 in the upper part of the circular gate 10. Is filled with molten metal (FIG. 5a), but when the hot water enters the molten metal solidification zone gap 17 having a two-stage gap, the passage is narrow, the heat capacity of the molten metal is small, and on the contrary, the cooling area is large, so the cooling rate is high. Since the solidification progresses and the fluidity decreases, the tip of the molten metal stops in the middle of the molten metal solidification zone gap 17 and does not solidify and enter the gas discharge gap 18.

  When the flow of the molten metal in the cavity stops, it is detected as a filling completion signal, and the closing pin 13 is immediately advanced and inserted into the circular gate 10 to close it. (Figure 5b). Thus, after the molten metal in the cavity product section 9 and the cavity first hot water reservoir 11 is closed so as not to flow backward to the stock, the pressurization stem 14 is immediately advanced to pressurize the interior of the cavity first hot water reservoir 11. The cavity product part 9 is replenished and filled with the molten metal in a semi-solid state (FIG. 5c). When the filling is completed and the cooling is started, solidification shrinkage of the molten metal 16 occurs. Therefore, a high pressure is applied to the pressurizing stem 14 to advance and replenishment according to the solidification shrinkage volume is performed. At this time, the contact between the molten metal and the mold surface is maintained, the cooling rate is fast, and the crystals become small. Further, when the circular gate 10 is closed by the closing pin 13, even if the contact between the closing pin 13 and the circular gate 10 is not perfect, the molten metal present in the small gap is quickly cooled and solidified, and the cavity first hot water reservoir is added. Even if pressed, the molten metal does not flow backward from the circular gate 10 to the pouring pan 6 through the cast stalk 40. Therefore, as shown in FIG. 2, after closing the circular gate 10 with the closing pin 13, the gas pressure in the pouring pan is immediately released to the atmosphere, and the pouring pan 6 is positioned below the lower end of the stalk in a state where the gas pressure has dropped to no danger. The molten metal remaining in the casting stalk 40 is dropped into the pouring pan 6 by using a vertical movement device (not shown). The lowered pouring pan 6 is moved to a position outside the casting machine by a horizontal movement device (not shown), and the molten metal necessary for the next time is supplied by the hot water supply ladle 42, and is again attached to the apparatus main body to prepare for the next casting.

  In the case of refilling with the pressurizing stem 14, the molten metal temperature in the mold cavity is higher, the pressurizing distance is shorter, the pressure transmission resistance is significantly smaller than the conventional die casting method, and The force of the pressure cylinder is small, and the hydraulic pressure in the hydraulic cylinder can be advanced with low pressure. By the replenishment filling by the advancement of the pressurizing stem 14, the molten metal replenishes and fills the cavity product portion 9 and the cavity second hot water reservoir 19, and then the pressurization pin 20 is advanced. The pressurization by the pressurization pin 20 is started by detecting this because the flow resistance increases and the hydraulic pressure increases with the completion of the filling by the pressurization stem 14. Replenishment according to the solidification shrinkage volume by the advancement of the pressurization stem 14 is difficult to transmit pressure to the opposite end of the cavity product part 9, so that the pressurization pin 20 around the end is actuated to pressurize the entire surface. In particular, a product with a dense structure free from shrinkage due to coagulation contraction can be obtained. After completion of the cooling and solidification of the molten metal in the cavity product section 9, the mold material is opened and the product material lifted by the movable mold 2 can be extruded and taken out by the pressure pins and the extrusion pins (FIG. 5d).

  FIG. 6 shows a case where the vertical casting apparatus of the present invention is applied to the production of aluminum wheels. The molten metal that has passed through the gate 10 enters the hub portion 9a of the product aluminum wheel corresponding to the cavity hot water storage portion 11 in the first embodiment, passes through the spoke portion 9b of the aluminum wheel corresponding to the side gate 12, and has a circumferential shape. The rim flange portion 9c is entered. Cavity second hot water reservoirs 19 are provided at several locations on the circumference of the upper end of the rim flange 9c to perform degassing and pressurization. The other operations are the same as in the first embodiment, and an aluminum wheel of high quality can be cast. Further, according to this method, the cavity first hot water reservoir 11 and the side gate 12 in the first embodiment are the product 9 (aluminum wheel). ), And there is little excess molten metal, and the hole by the blocking pin becomes the shaft hole of the aluminum wheel, and the casting weight of the cavity first hot water reservoir 11, that is, the hub 9a is reduced, and the cooling solidification rate The cycle time is shortened, the casting productivity is increased, and the shaft hole machining time in machining is shortened. And a quick cooling rate can make a crystal small, and can show the beauty of the surface important for the design nature of an aluminum wheel.

  FIG. 7 shows another example of the vertical casting apparatus of the present invention. As shown in FIG. 7, in the vertical casting apparatus of the present invention, the gas pressurized pouring pan 7 is provided with a molten metal supply pipe 44 that communicates with an opening provided in the lower part thereof, and a hot water supply port 46 of the molten metal supply pipe 44 is provided. An openable and closable hot water supply lid 47 having a sealing force capable of withstanding gas pressurization is provided. The hot water supply sleeve 45 provided in the upper part of the molten metal supply pipe 44 in such a vertical casting apparatus is provided with a gas outlet 49, and when the gas is pressurized, the pressurized gas inlet above the gas pressurized hot water pouring pan 7 is provided. While the pressurized gas is supplied from 41 and the same pressurized gas is supplied also from the gas outlet 49, the molten metal can be supplied and filled more efficiently. Then, after the molten metal inflow gate 10 is closed by the closing means, the gas pressure in the gas pressurized molten metal pan 7 is immediately released to the atmosphere and the gas in the hot water supply port gas part 48 of the molten metal supply pipe 44 is vacuumed from the gas outlet 49. Then, the molten metal surface 8a in the molten metal supply pipe 44 is pulled up, the molten metal surface 8 in the molten metal pan 7 is lowered to the lower end of the stalk 40, and the molten metal in the stalk 40 is dropped more quickly.

  According to the present invention, molten metal is filled into a mold cavity at high speed, and the molten metal in the closed cavity is effectively pressurized to easily cast a cast product that is free from shrinkage and does not involve gas. It is possible to provide a vertical casting apparatus that has high working efficiency and is easy to maintain and has a low equipment cost, and a vertical casting method using the vertical casting apparatus.

It is a schematic longitudinal cross-sectional view (at the time of the start of pouring) of the vertical casting apparatus of this invention. It is a schematic longitudinal cross-sectional view (at the time of hot water supply) of the vertical casting apparatus of this invention. It is sectional drawing of AA of FIG. It is explanatory drawing which shows the filling state of the molten metal in the vertical casting apparatus of this invention. It is explanatory drawing which shows the operation state in the vertical casting apparatus of this invention following FIG. It is a metal mold | die schematic longitudinal cross-sectional view when the vertical casting apparatus of this invention is applied to aluminum wheel production. It is a schematic longitudinal cross-sectional view of the vertical casting apparatus which concerns on the other example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed mold 2 Movable mold 3 Fixed platen 4 Movable platen 6 Pouring pot (gas pressurizing pouring pot)
7, 16 Molten metal 8 Molten metal surface 8a Molten metal surface of hot water supply pipe 9 Mold cavity 10 Circular gate 11 Cavity first hot water reservoir 12 Side gate 13 Blocking pin 14 Pressure stem 15 Jet 17 Pressure gap for molten metal coagulation zone 18 Pressure stem gas discharge gap 19 Cavity second hot water reservoir 20 Pressure pin 21 Pressure pin molten metal coagulation zone gap 22 Pressure pin peripheral gas discharge gap 23 Pressure stem piston 24 Closure pin piston 25 Hydraulic cylinders 26a, 26b , 26c Pressure oil inlet 27 Pressure stem Seal packing 28 Closure pin Seal packing 29 Pressure stem Gas discharge passage 30 Pressure pin Piston 31 Pressure pin hydraulic cylinder 32 Pressure oil inlet 33 Pressure pin Seal packing 34 Pressure pin Gas discharge Passage 35 Mold seal groove 36 Pressure stem cooling water hole 37 Pressure pin Cooling water hole 38 Hot water pot seal packing 39 Stoke seal packing 40 Cast stalk 41 Pressurized gas inlet 42 Hot water ladle 43 Outer peripheral type 44 Molten metal supply pipe 45 Hot water inlet sleeve 46 Hot water inlet 47 Hot water outlet lid 48 Hot water inlet gas section 49 Gas outlet inlet 9a Aluminum wheel hub part 9b Aluminum wheel spoke part 9c Aluminum wheel rim flange part

Claims (13)

Lower fixed mold and upper movable mold capable of forming mold cavities, closing means for closing the molten metal inflow gate formed in the fixed mold, and pressurizing the molten metal in the closed mold cavities An apparatus body having a pressurizing means;
A vertical casting apparatus comprising casting means for supplying and filling molten metal from below into the mold cavity,
The vertical casting apparatus characterized in that the casting means has a gas pressurized pouring pot that can be attached to and detached from the apparatus main body. The vertical casting apparatus according to claim 1, wherein the gas pressurized pouring pan is attached to the apparatus main body to form a sealed structure. The vertical casting apparatus according to claim 1 or 2, wherein the gas pressurized pouring pan has cast stalk, and an upper end portion of the cast stalk is brought into close contact with the apparatus main body to form a sealed structure. 3. The vertical casting apparatus according to claim 1, wherein the apparatus main body is provided with cast stalk, and an upper end portion of the gas pressurized pouring pan is brought into close contact with the apparatus main body to form a sealed structure. The vertical casting apparatus according to any one of claims 1 to 4, wherein the capacity of the pressurized gas pouring pot is a capacity capable of accommodating a molten metal required for one casting. The vertical casting apparatus according to any one of claims 1 to 5, wherein the gas pressurized pouring pan is provided with heating means. The casting mold according to any one of claims 1 to 6, wherein the casting means has a vacuum suction mechanism that vacuum-sucks the gas in the mold cavity and vacuum-fills the molten metal in the gas pressurized hot pot. Casting equipment. The mold cavity includes a gas discharge passage, and a gap for a molten metal solidification zone connected to the gas discharge passage is provided in the vicinity of the gas discharge passage. Vertical casting equipment. The gas pressurized pouring pan has a molten metal supply pipe communicating with an opening provided in a lower part thereof, and an openable and closable hot water supply lid having a sealing force capable of withstanding gas pressure is provided at a molten metal supply pipe. The die-casting apparatus according to any one of claims 1 to 8, wherein A casting method using the vertical casting apparatus according to any one of claims 1 to 9, wherein a molten metal is cast into a mold cavity through a casting stalk from a gas pressure pouring pot, and the molten metal fills the cavity. A vertical casting method characterized in that a molten metal inflow gate formed in a fixed mold is closed by a closing means, and then the molten metal in the mold cavity is pressurized by a pressure means. After closing the molten metal inflow gate with the closing means, immediately release the gas pressure in the gas pressurized molten metal pan to the atmosphere and desorb it from the main body of the equipment, supply the required molten metal to the gas pressurized molten metal hot pot, and again the device The vertical casting method according to claim 10, wherein the vertical casting method is attached to the main body to prepare for the next casting. The vertical casting method according to claim 10 or 11, wherein the gas pressure in the gas pressurizing pouring pan is adjusted to 1 kg / cm ² or more and cast at a high speed in a short time. The vertical casting method according to claim 10, wherein the casting is a light metal alloy thin and large casting.