JP2011067838A - Method of casting semi-molten metal and apparatus of casting semi-molten metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of casting semi-molten metal by light metal such as aluminum alloy with high quality and at low cost, and also to provide a technique of the casting apparatus. <P>SOLUTION: The method is materialized by a casting stage WO2 (WO4, WO5 or WO6) of semi-molten metal 50 in which a solid phase component and a liquid phase component coexist, including a stage of casting the semi-molten meal 50 into a prescribed shape by "mold clamping" of a die 2. The casting stage WO2 (WO4, WO5 or WO6) is composed of a high-speed molding process W21 in which, after the semi-molten metal 50 is cast in a cavity 2c inside the die 2, the "mold clamping" of the die 2 is performed at high speed with some interference left and a high pressure molding process W22 in which, after the high speed molding process 21 is completed, the remaining interference is clamped by a higher pressure than the high-speed molding process W21. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a casting method and a casting apparatus technology for casting a semi-molten metal made of a light metal such as an aluminum alloy at high quality and at low cost.

Conventionally, a die casting method is known as a casting method for obtaining a product having a desired shape by pressurizing molten metal into a mold.
In the die casting method, there are various methods such as a gravity casting method in which a molten metal is poured into a mold such as a sand mold and a squeeze casting method in which a high pressure is applied to the molten metal injected into a mold cavity to form and solidify. Is used.
In recent years, among these various methods, there are few shrinkage cavities and segregation due to solidification shrinkage, and the mold life is improved due to low temperature casting, so the solid phase component and the liquid phase component coexist. The semi-solid die casting method in which casting is performed using a semi-molten metal material is attracting attention.

As a specific method of the semi-solid die casting method, for example, a semi-solid metal obtained by stirring and solidification using a light metal such as an aluminum alloy as a material is directly cast into a casting sleeve of a die casting machine (a metallic material formed in a cylindrical shape). Die-casting machine for semi-molten metal obtained by dropping a required amount of solid cast rod obtained by dropping and injection molding into the charging part) and injection molding, and reheating. There has been known a thixocasting method in which it is inserted into a cast sleeve and injection molded.
Of these two methods, the rheocast method has many problems such as a long semi-solid metal production cycle and a large equipment as compared to the thixocast method, which increases equipment costs. The method is often used.

By the way, when the thixocasting method is performed, as described above, a metal material made of a semi-molten metal is put into a casting sleeve and extruded (injected) by a pusher to fill the metal cavity into the mold cavity. Will be allowed to.
Here, since the casting sleeve and the cavity communicate with each other through a gate (a hole communicating the mold exterior and the cavity) formed inside the mold, the metal introduced into the casting sleeve The flow distance until the material reaches the cavity is increased.
As a result, the metal material often entrains air and dust as it moves through the casting sleeve, gate, and cavity, causing internal defects.

In addition, since the flow distance of the metal material is increased, the temperature of the metal material is decreased before reaching the cavity, and the solidification partially proceeds.
As a result, the pressure propagation to the metal material by the pusher becomes dull, and an excessive pressure is required accordingly, so that the entire equipment becomes bulky.

Further, depending on various conditions such as the equipment layout, the cavity mainly extends upward at the downstream end portion (the end portion in the direction of pushing out the metal material by the pusher) of the horizontally disposed casting sleeve. Therefore, the injection direction of the metal material in the casting sleeve and the flow direction of the metal material to the cavity through the gate intersect at a substantially right angle.
As a result, the pressure required by the pusher to extrude the metal material becomes excessive, and the entire equipment becomes bulky.

Therefore, as techniques for improving such a point, various techniques shown in the following “Patent Document 1” and “Patent Document 2” have been proposed.
For example, in “Patent Document 1”, a mold into which a molten metal is poured is cooled while applying a primary pressure, and a semi-solid product is cast in a semi-solid state, and the mold is removed without removing the semi-molded product from the mold. A technique is disclosed in which a molded product is manufactured by plastically deforming at least a part of the semi-molded product while applying a secondary pressure greater than the primary pressure to the mold.

  Further, in “Patent Document 2”, a die casting process in which a molten metal is filled at high speed in a cavity and a primary processed product close to the shape of a final product is formed by die casting, and the primary processed product has a solid phase ratio of 30 to 70%. There is disclosed a technique relating to a metal forming method comprising a pressing step of press forming to the size and shape of the final product in a semi-molten state.

JP 2005-74461 A Japanese Patent Laid-Open No. 5-305409

  By using the techniques according to the “Patent Document 1” and “Patent Document 2”, it is possible to obtain a higher-quality cast product at a low cost when the semi-solid die casting method is performed. Seem.

  However, in the technique in the above-mentioned “Patent Document 1”, in a semi-molded product in a semi-solidified state, in the surface layer portion that is always in contact with the mold, solidification proceeds compared to the inside, and a region where the flow stops is generated. Become. Therefore, flow disturbance occurs inside the semi-molded product, causing internal defects such as a hot water boundary and air entrainment, and it is difficult to obtain a high-quality cast product.

  Moreover, in the technique in the above-mentioned “Patent Document 2”, since the die casting process and the pressing process are each performed by separate dies, the entire equipment is bulky and the primary processed product is moved between these processes. At this time, there is a high possibility that the primary processed product is contaminated by oxidation or the like, and internal defects are caused by the entrapment of the surface oxide film, and it is difficult to obtain a high-quality cast product.

  The present invention has been made in view of the above improvements, and a casting method and casting apparatus for casting a semi-molten metal made of a light metal such as an aluminum alloy by a thixocast method at high quality and at low cost. The issue is to provide the technology.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, according to claim 1, a method of casting a semi-molten metal in which a solid phase component and a liquid phase component coexist, and the step of casting the semi-molten metal into a predetermined shape by “clamping” a mold. And the step includes: a mold clamping step for performing “clamping” of the mold while leaving some clamping allowance after the semi-molten metal is charged into the cavity inside the mold; and the mold clamping step After the completion of the above, a high-pressure molding step of clamping the remaining clamping allowance at a higher pressure than the mold clamping step.

  According to a second aspect of the present invention, the mold clamping process “clamps” the mold at a higher speed than the high-pressure molding process.

  According to a third aspect of the present invention, the atmosphere inside the cavity is replaced with an inert gas before the semi-molten metal is put into the cavity, and in the mold clamping step, the inert gas flows into the cavity. The back pressure generated between the inner surface of the cavity and the surface of the semi-molten metal is adjusted by adjusting the amount of entry and exit.

  According to a fourth aspect of the present invention, in the mold clamping step, vibration in the mold clamping / die opening direction is applied to the mold to be “clamped”.

  In claim 5, in the mold clamping step, the mold to be “clamped” is subjected to vibration in a mold clamping / mold opening direction, and the adjustment of the back pressure is performed by clamping the mold. The amount of the inert gas flowing into and out of the cavity is adjusted based on the timing at which the vibration in the direction is applied and the degree of cross-sectional change of the semi-molten metal at a predetermined portion.

  6. A semi-molten metal casting apparatus in which a solid phase component and a liquid phase component coexist, comprising: a mold for casting a semi-molten metal charged into a cavity into a predetermined shape; The mold is composed of a fixed mold and a movable mold, and the mold is “clamped” by moving the movable mold relative to the fixed mold. The mold clamping means for performing “clamping” of the mold with some clamping allowance, and after the “clamping” by the mold clamping means, continuously at a higher pressure than the mold clamping means. And high pressure molding means for “clamping” the remaining clamping allowance while applying pressure to.

  According to a seventh aspect of the present invention, the mold clamping unit performs “clamping” of the mold at a higher speed than the high pressure molding unit.

  In claim 8, the mold is provided with back pressure adjusting means for substituting the atmosphere inside the cavity with an inert gas before the semi-molten metal is put into the cavity. During the execution of “clamping”, the back pressure adjusting means adjusts the inflow / outflow amount of the inert gas into the cavity so that the inner surface of the cavity and the surface layer surface of the semi-molten metal It adjusts the back pressure generated between them.

  According to a ninth aspect of the present invention, the mold is provided with a vibration mechanism, and when the movable mold is relatively moved toward the fixed mold by the mold clamping unit, the movable mechanism is moved by the vibration mechanism. The mold is given vibration in the direction of clamping and opening.

  According to a tenth aspect of the present invention, the mold is provided with a vibration mechanism, and when the movable mold is relatively moved toward the fixed mold by the mold clamping unit, the movable mechanism is moved by the vibration mechanism. Vibration in the mold clamping / die opening direction is applied to the mold, and the adjustment of the back pressure is determined in advance by the timing at which vibration in the mold clamping direction is applied to the mold and the semi-molten metal. The amount of the inert gas flowing into and out of the cavity is adjusted based on the degree of cross-sectional change in the region.

  As effects of the present invention, the following effects can be obtained.

  That is, according to the semi-molten metal casting method and semi-molten metal casting apparatus of the present invention, it is possible to cast a semi-molten metal made of a light metal such as an aluminum alloy by a thixocast method at high quality and at low cost. it can.

The process figure which showed the whole shaping | molding process which comprises the casting process of the semi-molten metal which concerns on 1st Example of this invention. The graph which showed the relationship between the thickness of the product cast in 1st Example, and the flow length of the metal of a semi-molten state for every different molding speed (clamping speed). The process figure which showed the whole shaping | molding process which comprises the casting process of the semi-molten metal which concerns on 2nd Example of this invention. In 2nd Example, it is the figure which showed an example of the metal mold | die used for the casting process of a semi-molten metal, (a) is sectional drawing which showed the state which the metal mold | die opened, (b) is a metal mold | die closed. Sectional drawing which showed the state. The expanded sectional view which showed the vicinity of the semi-molten metal pressed by the metal mold | die of a closed state in 2nd Example. The process figure which showed the whole shaping | molding process which comprises the casting process of the semi-molten metal which concerns on the 3rd Example of this invention. Sectional drawing which showed an example of the metal mold | die used for the casting process of a semi-molten metal in a 3rd Example. The expanded sectional view which showed the vicinity of the semi-molten metal pressed by the metal mold | die of a closed state in 3rd Example. The process figure which showed the whole forming process which comprises the casting process of the semi-molten metal which concerns on 4th Example of this invention. In 4th Example, it is the figure which showed an example of the metal mold | die used for the casting process of a semi-molten metal, (a) is sectional drawing which showed the state which the metal mold | die opened, (b) is a metal mold | die closed. Sectional drawing which showed the state. Whole sectional drawing which showed an example of the casting apparatus used in 4th Example. It is the figure which showed operation | movement of the casting apparatus used in 4th Example, (a) is the whole sectional drawing which showed the state at the time of high speed shaping | molding, (b) is the whole sectional drawing which showed the state at the time of high pressure forming. The flowchart which showed the control method regarding the back pressure in a metal mold | die used in 4th Example.

  Next, embodiments of the invention will be described.

[Semi-molten metal forming step W100]
First, an outline of the entire semi-molten metal forming step W100 including a casting step W02 (first embodiment) that embodies the semi-molten metal casting method according to the present invention will be described with reference to FIG.

  The semi-molten metal to be cast in the present embodiment is a metal having a solid phase component and a liquid phase component coexisting, and is generally different from other molten metals and solid metals. Has characteristics.

  That is, the deformation resistance of the semi-molten metal (stress necessary for deforming the material) varies slightly depending on the solid phase ratio, but is considerably smaller than that of the solid metal. Therefore, semi-molten metal is cast by mold clamping force (force applied to keep the mold closed against the pressure of the metal material filled in the mold) by a relatively small load compared to solid metal. It can be performed.

  On the other hand, the solidification shrinkage of the semi-molten metal may be considered by focusing only on the inherent liquid phase component. Therefore, although slightly changing depending on the solid phase rate, the solidification shrinkage rate of the semi-molten metal is considerably smaller than that of the molten metal having the same volume. Therefore, cracks and internal defects generated by solidification shrinkage can be easily avoided by replenishing an amount corresponding to a small amount of solidification shrinkage in semi-molten metal as compared with molten metal.

  Based on such characteristics of the semi-molten metal, the casting steps W02, W04, W05, and W06, which will be described in detail as the first to fourth embodiments below, are high-quality and low-cost castings of the semi-molten metal. Is possible.

The semi-molten metal forming step W100 in the present embodiment is mainly composed of a pre-process W01, a casting process W02, and a post-process W03.
The pre-process W01 is a process for supplying a semi-molten metal to a mold for actual casting.
Specifically, in the pre-process W01, mainly the arrival of the semi-molten metal, the heating of the semi-molten metal (heating the semi-molten metal to a predetermined processing temperature), the heating of the semi-molten metal Transport to the mold is performed.

The casting process W02 is a process in which the semi-molten metal transported in the previous process W01 is put into a mold and actually cast by the mold.
The casting process W02 includes a high-speed molding process W21 and a high-pressure molding process W22 as will be described later.

The post-process W03 is a process for finishing the semi-molten metal cast into the intermediate product by the casting process W02 into a final product.
Specifically, in the post-process W03, mainly the removal of the intermediate product from the mold, the cooling of the intermediate product, the excision of extra protrusions fixed to the intermediate product, and the like are performed.

  By performing such a series of steps (pre-process W01, casting process W02, and post-process W03), the semi-molten metal in which the solid phase component and the liquid phase component coexist is finished into a final product.

[Semi-molten metal casting process W02 (first embodiment)]
Next, details of the semi-molten metal casting step W02 (first embodiment) in the present embodiment will be described with reference to FIGS.

As shown in FIG. 1, the casting process W02 is a process of casting a semi-molten metal into a predetermined shape, and includes a high-speed molding process W21 and a high-pressure molding process W22.
The high-speed molding process W21 is a mold clamping process in which the mold is “clamped” while leaving some clamping allowance, and the mold “mold” is controlled by a high molding speed, that is, a high mold clamping speed. It is a process of performing “tightening”.

  That is, for example, when the mold used in the casting process W02 is composed of a fixed mold and a movable mold that can move relative to the fixed mold, a semi-molten metal is placed in the cavity inside the mold. After the loading, when the fixed mold and the movable mold are matched (“clamping”), the speed related to the relative movement of the movable mold is performed at a high speed.

Here, the relationship between the “product thickness” and the “flow length” of the semi-molten metal when the molding speed (clamping speed) is different will be described with reference to FIG.
“Product thickness” means the thickness of the product formed by solidification of the semi-molten metal in the cavity (the space in which the metal material flows, having almost the same shape as the cast product in the mold). It is shown and means a gap in the cavity. The “flow length” indicates the distance from the filling position of the semi-molten metal into the cavity to the flow end of the flow of the semi-molten metal.

  Generally, in the relationship between “product thickness” and “flow length” in semi-molten metal, “flow length” increases as “product thickness” increases. That is, as the gap in the cavity increases, the semi-molten metal becomes easier to flow, and the semi-molten metal reaches the flow end that is further away from the filling position.

Here, if the molding speed (clamping speed) is changed while keeping the “product thickness” constant, the “flow length” increases as the molding speed (clamping speed) increases.
That is, as shown in FIG. 2, for example, when attention is paid to the case where “product thickness” is “A” in the figure, a molding speed (clamping speed, about approx. When the molding speed (clamping speed) is gradually increased as shown in the graph (b) to the graph (f) with respect to the graph (a) indicating 0.03 m / S), the “flow length” It turns out that it becomes long gradually. (Note that the size relationship of the molding speed (clamping speed) shown in FIG. 2 is (a) <(b) <(c) <(d) <(e) <(f)).

  On the other hand, the semi-molten metal immediately after being put into the mold cavity has a small amount of heat released to the outside and a small deformation resistance.

  For this reason, in this embodiment, a high-speed molding process W21 as a mold clamping process is provided in the initial stage of the casting process W02. For example, a high molding speed (clamping speed) of about 1.0 m / S is provided. Therefore, the mold is “clamped”. As a result, in the casting process W02 in the present embodiment, the semi-molten metal that can sufficiently fill the thin wall portion of the product (where the gap between the cavities is narrow) without applying a high-pressure load to the separate mold. To ensure liquidity.

  Therefore, in the high-speed molding process W21, since a high-pressure load is not applied to the separate mold, the equipment can be simplified correspondingly and the entire casting apparatus can be made compact.

If the “clamping” of the mold is completed while leaving some clamping allowance in the high-speed molding process W21, the high-pressure molding process W22 is continuously performed.
The high-pressure forming step W22 is a step of performing “clamping” of the mold with a pressure (for example, about 50 MPa or more) higher than the pressure employed in a conventional hydraulic press machine, and the remaining high-pressure forming step W22. The cost is “clamped” and the “clamping” of the mold is completed.

  As described above, in this embodiment, the high pressure molding process W22 is provided in the latter stage of the casting process W02, and the high speed molding process W21 in the initial stage is continuously switched to the high pressure molding process W22. It prevents the unfilling of the molten metal.

  That is, when performing “clamping” of the mold, at least a part of the surface layer of the semi-molten metal always comes into contact with the inner surface of the cavity. Therefore, the amount of heat inherent in the semi-molten metal is gradually taken away by the mold through the inner surface of the cavity, so that the solid phase ratio of the semi-molten metal also gradually increases, and in the latter stage of the casting process W02 The deformation resistance of the semi-molten metal is also large.

  By semi-melting such a semi-molten metal with increased deformation resistance by high pressure in the high-pressure forming process W22, the mold is surely semi-melted even in a narrow cavity space. It can be filled with metal.

Moreover, it was generated due to solidification shrinkage of the final solidified portion in the semi-molten metal (the last solidified region in the entire semi-molten metal) by adding to the mold while stably maintaining a high pressure by the high-pressure forming step W22. Metal can be easily supplied to the gap.
Therefore, internal defects such as shrinkage cavities generated in the semi-molten metal during casting can be effectively prevented, and a high-quality cast product can be obtained.

The molding speed (clamping speed) in the high-pressure molding process W22 is not limited to either high speed or low speed, but it is preferable to perform at a low speed in order to apply a stable high pressure to the mold. .
In other words, the high-speed molding step W21 preferably “clamps” the mold at a higher speed than the high-pressure molding step W22.

  Thus, the casting process W02 in the present embodiment is configured by two-stage processes, that is, a high-speed molding process W21 as a mold clamping process and a high-pressure molding process W22 having a higher molding pressure than the high-speed molding process W21. Therefore, even for semi-molten metal, which has a large deformation resistance compared to molten metal, it is possible to secure a sufficient “flow length” for the thin-walled part of the product (where the cavity gap is narrow). Can be easily handled.

[Semi-molten metal casting process W04 (second embodiment)]
Next, details of the semi-molten metal casting step W04 (second embodiment) in the present embodiment will be described with reference to FIGS.
For convenience, the vertical direction in FIGS. 4 and 5 is defined as the vertical direction of the mold 2 and will be described below.

  As shown in FIG. 3, the casting process W04 in the present embodiment is composed of a high-speed molding process W21 as a mold clamping process and a high-pressure molding process W22 as in the casting process W02 in the first embodiment described above. The mold atmosphere control P41 is performed before and during the high-speed molding step W21.

  Also, before and after the casting process W04, a pre-process W01 and a post-process W03 are respectively provided as in the first embodiment, and the pre-process W01, the cast process W04, and the post-process W03 are respectively provided. A semi-molten metal forming step W200 is configured.

  Note that the high-speed molding step W21 and the high-pressure molding step W22, and the pre-step W01 and the post-step W03 have already been described in the above-described first embodiment, and thus the following description is omitted.

The mold atmosphere control P41 mainly includes an inert gas replacement control P42 and a back pressure control P43.
The inert gas replacement control P42 is control for replacing the atmosphere inside the cavity of the mold with an inert gas, and is performed before the execution of the high-speed molding step W21.

  That is, the inert gas replacement control P42 is performed before the semi-molten metal is introduced into the cavity of the mold, and after the atmosphere in the cavity is completely replaced with the inert gas by the inert gas replacement control P42. The semi-molten metal is put into the cavity, and the “clamping” of the mold by the high-speed molding process W21 is started.

  By performing such inert gas replacement control P42 before execution of the high-speed forming step W21, in the casting step W04 in this embodiment, contamination such as oxidation of the semi-molten metal introduced into the cavity during casting is effective. Therefore, high-quality cast products can be obtained.

  That is, with respect to the oxidation region of the semi-molten metal generated at the time of charging into the cavity, the atmosphere in the cavity after the charging has already been replaced by the inert gas, so that the semi-molten metal is not further expanded. The occurrence of defects due to the inclusion of the surface oxide film can be reduced, and a high-quality cast product can be obtained.

  The back pressure control P43 controls the back pressure generated between the inner surface of the mold cavity and the surface layer of the semi-molten metal when performing the "clamping" of the mold. After the high-speed molding process W21 is started, the process is continuously performed until the high-pressure molding process W22 is switched to.

  Specifically, as shown in FIG. 4A, the mold 2 used in the casting process W04 includes a fixed mold 2B fixed to a fixed frame or the like of the casting apparatus, and the fixed mold 2B. The movable mold 2A is provided so as to be capable of relative movement (up-and-down movement). The concave and convex portions 2a and 2b are formed on the planes of the molds 2A and 2B facing each other.

  Then, as shown in FIG. 4 (b), the movable mold 2A moves relative to the fixed mold 2B (moves up and down), and these molds 2A and 2B match ("clamp"). Thus, the cavity 2c is formed by the concavo-convex portions 2a and 2b, and the semi-molten metal 50 previously charged in the concave portion 2b of the fixed mold 2B is cast along the shape of the cavity 2c. .

On the other hand, the fixed mold 2B is formed with a plurality (two in this embodiment) of communication holes 2d and 2e that communicate the inner surface side of the recess 2b and the outer surface side of the fixed mold 2B. For each of 2d and 2e, there are a supply path (not shown) for supplying an inert gas into the cavity 2c and a discharge path (not shown) for discharging the cavity 2c from the mold 2 to the outside of the mold 2. Each communicates.
The supply path and the discharge path are respectively connected to a cylinder for storing the inert gas (or an inert gas supply source installed on the factory line) via a regulating valve for flow rate and pressure. The

  And during the execution of the high-speed forming step W21, the inert gas is blown into the cavity 2c by pumping the inert gas from the cylinder into the communication holes 2d and 2e, and the surface layer surface of the semi-molten metal 50, The back pressure generated between the inner surface of the cavity 2c is increased, or conversely, the back pressure is reduced by discharging the inert gas existing inside the cavity 2c to the outside of the mold 2 and returning it to the cylinder. It is supposed to be.

That is, as shown in FIG. 5, during the execution of the high-speed forming step W21, the semi-molten metal 50 is rapidly pressed on the upper surface by the convex portion 2a of the movable mold 2A and rapidly flows downward.
Therefore, an air layer is generated between the lower surface of the semi-molten metal 50 and the inner surface of the concave portion 2b of the fixed mold 2B, that is, a portion where the air layer is difficult to escape in the cavity 2c, that is, the thin wall of the product described above. In the portion (the portion where the gap between the cavities 2c is narrow), the air layer becomes an air reservoir 30 and stagnates, preventing the semi-molten metal 50 from flowing further downward (bottom of the recess 2b).

On the other hand, in the thick part of the product (where the gap of the cavity 2c is wide), the air layer passes through a slight gap generated between the surface of the semi-molten metal 50 and the inner surface of the recess 2b. Since it is released to the outside of the mold 2 without difficulty, a back pressure as shown in the air reservoir 30 is not established between the semi-molten metal 50 and the inner surface of the recess 2b of the fixed mold 2B.
Therefore, in the semi-molten metal 50, only the liquid phase component having a low flow resistance is extruded downward (the bottom of the recess 2b), and a deviation from the solid phase component occurs partially.

  Therefore, in order to prevent such a phenomenon, back pressure control P43 is performed during execution of the high-speed molding step W21, and through the communication hole 2e that communicates with the thin portion of the product (the portion where the cavity 2c is narrow) in the recess 2b. By sucking the inert gas into the cylinder, the air pool 30 is prevented from being generated, and the semi-molten metal 50 flows sufficiently downward (bottom of the recess 2b).

  At the same time, back pressure control P43 is performed during execution of the high-speed molding step W21, and the inert gas is bombarded through the communication hole 2d communicating with the thick part of the product in the recess 2b (the part where the gap of the cavity 2c is wide). By blowing more, an appropriate back pressure is established between the surface layer surface of the semi-molten metal 50 and the inner surface of the recess 2b, so that a partial divergence between the liquid phase component and the solid phase component does not occur. Yes.

  In other words, in the present embodiment, the back pressure control P43 adjusts the amount of the inert gas that flows into and out of the mold 2 during the high-speed molding step W21, so that the inner surface of the cavity 2c, The back pressure generated between the surface layer of the semi-molten metal 50 is adjusted.

  Thus, by performing the back pressure control P43 in accordance with the execution of the high-speed forming step W21, the “flow length” of the semi-molten metal 50 with respect to the thin portion of the product (the portion where the gap of the cavity 2c is narrow) is sufficiently ensured. At the same time, it is possible to suppress a partial divergence between the liquid phase component and the solid phase component with respect to the thick part of the product (the portion where the gap of the cavity 2c is wide), and a high-quality cast product can be obtained.

In the present embodiment, the supply / discharge paths related to the inert gas are communicated with each other for each of the plurality of communication holes 2d and 2e. However, the present invention is not limited to this.
That is, for example, when it is not necessary to partially distinguish the supply / discharge of the inert gas due to the shape of the cavity 2c, a common supply / discharge path related to the inert gas is provided for the plurality of communication holes 2d, 2e. It is good also as a structure to be made.
That is, in the shape of the cavity 2c, when only a plurality of thin parts of the product are provided, or when only a plurality of thick parts of the product are provided, the plurality of places are provided in accordance with the execution of the high-speed molding process W21. In contrast, the inert gas may be supplied or discharged simultaneously, and a common supply / discharge path related to the inert gas may be provided for the plurality of communication holes 2d and 2e.

  In addition, the inert gas supply means used for the back pressure control P43, that is, the communication holes 2d and 2e and the cylinders (not shown) are the same as the inert gas supply means used for the mold internal atmosphere control P41. It may be common.

[Semi-molten metal casting process W05 (third embodiment)]
Next, details of the semi-molten metal casting step W05 (third embodiment) in the present embodiment will be described with reference to FIGS.
For convenience, the vertical direction in FIGS. 7 and 8 is defined as the vertical direction of the mold 2 and will be described below.

  As shown in FIG. 6, the casting process W05 in the present embodiment is composed of a high-speed molding process W21 as a mold clamping process and a high-pressure molding process W22 as in the casting process W02 in the first embodiment described above. The mold vibration control P51 is performed during the execution of the high-speed molding step W21.

  Also, before and after the casting process W05, a pre-process W01 and a post-process W03 are respectively provided in the same manner as in the first embodiment, and the pre-process W01, the casting process W05, and the post-process W03 are respectively provided. A semi-molten metal forming step W300 is configured.

  Note that the high-speed molding step W21 and the high-pressure molding step W22, and the pre-step W01 and the post-step W03 have already been described in the above-described first embodiment, and thus the following description is omitted.

  The mold vibration control P51 is a control for applying an impact force that oscillates in small steps in the mold clamping direction when the mold is "clamped". After the high-speed molding process W21 is started, It continues until it switches to the high pressure molding process W22.

  Specifically, as shown in FIG. 7, the vibration mechanism 7 that performs the mold vibration control P51 is mainly composed of a cam plate 14, a vibration rod 15, a housing 16, and the like, and the vibration mechanism A movable mold 2A is fixed to the lower portion of the sheet 7, and a fixed mold 2B is disposed immediately below the movable mold 2A.

  Similar to the above-described casting process W04 (second embodiment), the mold 2 used in the casting process W05 in the present embodiment is a fixed mold 2B fixed to a fixed frame or the like of the casting apparatus, The movable mold 2A is configured to be movable relative to the fixed mold 2B (moving up and down).

The cam plate 14 is formed of a disk member, and a through hole 14a is formed in a flat portion of the cam plate 14 at a position eccentric to the center.
The cam plate 14 is disposed above the elevating frame 4 provided in the casting apparatus so that the axial center direction of the through hole 14a is a horizontal direction (a direction perpendicular to the elevating movement direction of the elevating frame 4). In addition, an output shaft of a servo motor (not shown) is provided in the through hole 14a. The cam plate 14 is rotationally driven by the driving force of the servo motor.
That is, the outer peripheral shape of the cam plate 14 is formed in an arc shape in which the distance from the through hole 14a serving as the rotation center to the outer peripheral edge portion continuously changes.

The housing 16 is formed of a cylindrical member, and is fitted in the central portion of the lifting frame 4 so that the axial direction is the vertical direction.
In addition, a plate-like member 19 having a through-hole formed in the central portion in plan view is fixed to the lower end portion of the housing 16, and the through-hole is formed to have the same inner diameter as the housing 16. The member 19 is fixed coaxially with the housing 16.

The vibration rod 15 is formed of a rod-like member, and is inserted into the inner diameter portion of the housing 16 so as to be slidable up and down (in the up-and-down movement direction of the lifting frame 4).
The lower end of the outer edge of the cam plate 14 is in line contact with the upper end surface of the excitation rod 15, while the movable mold 2 </ b> A is formed on one side of the lower end portion of the excitation rod 15. 2a is fixed downward.

  A step portion 15a having a diameter larger than that of other portions is formed at the upper end portion of the vibration rod 15, and a coil spring or the like is formed between the lower surface of the step portion 15a and the upper surface of the housing 16. The urging means 17 is disposed coaxially with the excitation rod 15. The oscillating rod 15 is always urged upward by the urging means 17. Thus, the upper end surface of the excitation rod 15 is always in pressure contact with the lower end surface of the cam plate 14.

  When the servo motor is driven to rotate, the cam plate 14 is rotated about the axis of the through hole 14a, and the position of the lower end portion of the outer edge of the cam plate 14 is continuously displaced in the vertical direction. The Rukoto.

As a result, in synchronization with the displacement operation of the lower edge portion of the outer edge of the cam plate 14, the excitation rod 15 is also slid in the vertical direction.
That is, while the position of the outer edge lower end portion of the cam plate 14 is displaced in the direction away from the through hole 14a, the excitation rod 15 slides downward against the biasing force of the biasing means 17 by the cam plate 14, While the position of the lower end portion of the outer edge of the cam plate 14 is displaced in the direction approaching the through hole 14 a, the excitation rod 15 slides upward by the urging force of the urging means 17.

The downward sliding and upward sliding of the vibration rod 15 are alternately repeated as the cam plate 14 rotates, and the vibration rod 15 vibrates up and down.
The vibration of the vibration rod 15 is transmitted to the movable mold 2A provided at the lower end of the vibration rod 15, and is applied as an impact force.

As will be described later, a plate-like member 19 is affixed to the lower surface of the elevating frame 4, and a biasing means 21 made of a disc spring or the like is interposed between the plate-like member 19 and the movable mold 2A. Has been.
During the execution of the high-speed molding step W21, the urging means 21 always urges the movable mold 2A downward (in the direction in which the movable mold 2A moves away from the elevating frame 4 side). Some clearance is secured between the movable mold 2A.

  By performing the mold vibration control P51 by the vibration mechanism 7 in accordance with the execution of the high-speed forming step W21, the “flow of the semi-molten metal 50 to the thin portion of the product (the portion where the gap of the cavity 2c is narrow) is performed. It is possible to sufficiently secure the “length”, and a high-quality cast product can be obtained.

That is, as shown in FIG. 8, during the execution of the high-speed forming step W21, the surface layer of the upper part of the semi-molten metal 50 is always in contact with the convex portion 2a of the movable mold 2A. The amount of heat taken away (arrow X shown in FIG. 8) is large, and solidification tends to proceed due to the cooling effect.
Therefore, a region where the flow partially stops (flow stop portion) is generated on the surface of the upper surface of the semi-molten metal 50, and the flow disturbance is generated in the vicinity of the upper surface of the semi-molten metal 50 (FIG. 8). The arrow Y) shown in FIG. 2 occurs, and internal defects such as “bath” and “air entrainment” tend to occur.

  Therefore, during the execution of the high-speed molding process W21, the vibration of the vibration rod 15 is transmitted to the movable mold 2A by the mold vibration control P51, and the impact force due to this vibration is transmitted to the mold clamping / die opening direction ( The surface layer on the upper surface of the semi-molten metal 50 is always in dynamic contact with the convex portion 2a of the movable mold 2A. Locations can be reduced as much as possible.

  That is, even in the high-speed molding process W21 in which an additional load is applied to the mold 2 at a low pressure, the impact force generated by the vibration of the vibration rod 15 is applied to the movable mold 2A, which is comparable to the subsequent high-pressure molding process W22. The clamping force to be applied can be applied to the mold 2.

  Therefore, even in the region where solidification has started to progress on the surface of the upper surface of the semi-molten metal 50, the “flow length” can be sufficiently ensured, and the occurrence of internal defects in the semi-molten metal 50 can be prevented. Can be obtained.

  More effectively, the impact force applied to the movable mold 2A is such that the smaller the amplitude and the greater the frequency, the more the movable mold 2A per stroke and the semi-molten metal 50 This is desirable because the contact time can be shortened.

  Further, in addition to the lowering operation (clamping operation) of the movable mold 2A in the high-speed molding step W21 as described above, the impact force is applied to the movable mold 2A by the vibration mechanism 7, thereby lowering the movable mold 2A. The capacity of the lifting mechanism body required for performing the operation (clamping operation) can be reduced, and the entire casting apparatus can be made compact.

[Semi-molten metal casting process W06 (fourth embodiment)]
Next, details of the semi-molten metal casting step W06 (fourth embodiment) in this embodiment will be described with reference to FIGS.
For convenience, the vertical direction in FIG. 10 is defined as the vertical direction of the mold 2, and the vertical direction in FIGS. 11 and 12 is defined as the vertical direction of the casting apparatus 1.

  As shown in FIG. 9, the casting process W06 in this embodiment is composed of a high-speed molding process W21 as a mold clamping process and a high-pressure molding process W22 in the same manner as the casting process W02 in the first embodiment described above. Before and during the execution of the high-speed molding step W21, the mold atmosphere control P41 in the second embodiment is performed, and during the execution of the high-speed molding step W21, the metal mold in the third embodiment is performed. The mold excitation control P51 is performed.

  Also, before and after the casting process W06, a pre-process W01 and a post-process W03 are respectively provided in the same manner as in the first embodiment, and the pre-process W01, the cast process W06, and the post-process W03 are respectively provided. A semi-molten metal forming step W400 is configured.

  Note that the high-speed molding step W21 and the high-pressure molding step W22, and the pre-step W01 and the post-step W03 have already been described in the above-described first embodiment, and thus the following description is omitted.

  The casting process W06 in the present embodiment is to simultaneously obtain the mold atmosphere control P41 and the mold vibration control P51 in the second and third embodiments described above to obtain a higher quality cast product. It is possible.

  That is, as shown in FIG. 10A, when only the mold vibration control P51 is performed alone during execution of the high-speed molding step W21, it depends on the shape of the cavity 2c formed inside the mold 2. For example, the liquid phase component mixed in the semi-molten metal 50 may be significantly extruded, and the deviation from the solid phase component may partially occur.

That is, as shown in FIG. 10B, in the shape of the cavity 2c, the surface layer surface of the semi-molten metal 50 easily flows in a region having a relatively wide gap, and the cross-sectional change of the semi-molten metal 50 (FIG. 10). In (b), the change in the cross-sectional area regarding the portion of the semi-molten metal 50 indicated by the arrow Z) is also severe. In such a portion of the semi-molten metal 50, the liquid phase component is separated from the solid phase component due to its own weight, and the phenomenon of being squeezed out easily occurs.
Such a phenomenon becomes prominent when an impact force is applied to the movable mold 2A by the mold excitation control P51.

  In this embodiment, in order to prevent such a partial separation between the liquid phase component and the solid phase component in the semi-molten metal 50, the above-described second and A higher quality cast product is obtained as compared with the casting steps W04 and W05 in the third embodiment.

[Semi-molten metal casting equipment 1]
First, an example of the casting apparatus 1 that performs the casting process W06 in the present embodiment will be specifically described with reference to FIG.

The casting apparatus 1 mainly includes a mold 2, a fixed frame 3, a lifting frame 4, a high-speed lifting mechanism 5, 5, a high-pressure lifting mechanism 6, 6..., A vibration mechanism 7, and back pressure control. The apparatus 20 is configured.
The mold 2 has the same structure as that of the casting process W04 (second embodiment), and the vibration mechanism 7 has the same structure as that of the casting process W05 (third embodiment). Detailed description will be omitted below.

First, the fixed frame 3 will be described.
The fixed frame 3 is a part forming the base of the casting apparatus 1 and has a rectangular housing structure.
A fixed mold 2B provided in the mold 2 is fixedly provided at a central portion of the upper surface of the fixed frame 3 in plan view, and the fixed mold 2B is arranged so that a concave portion 2b formed on one side faces upward. Established.

  A plurality of high speed elevating mechanisms 5 and 5 and high pressure elevating mechanisms 6 and 6 to be described later are respectively provided around the fixed mold 2B. The high speed elevating mechanisms 5 and 5 and the high pressure elevating mechanism 6 are provided. Via 6 ..., the raising / lowering frame 4 is connected with this fixed frame 3 so that relative movement (up-and-down movement) is possible with respect to the fixed frame 3.

Next, the lifting frame 4 will be described.
The elevating frame 4 is made of a rectangular member with sufficient rigidity so as not to be bent or twisted by an external force, and is provided vertically above the fixed frame 3.
The above-described vibration mechanism 7 penetrates through the central portion of the lifting frame 4 in a plan view, and a movable mold 2A included in the mold 2 is formed on one side surface at the lower end of the vibration mechanism 7. The protruding portion 2a is disposed so as to protrude downward.

  Between the plate-like member 19 stuck on the lower surface of the elevating frame 4 and the movable mold 2A, a biasing means 21 made up of a disc spring or the like is interposed. When an upward force is applied to the movable mold 2A (a direction in which the movable mold 2A approaches the lifting frame 4 side), a force for biasing the movable mold 2A downward by the biasing means 21 is generated. Yes.

  The lifting frame 4 can be moved up and down by a plurality of high-speed lifting mechanisms 5 and 5 or high-pressure lifting mechanisms 6 and 6 to be described later, and the lifting frame 4 is lowered to move the movable mold 2A. The convex part 2a is matched with the concave part 2b of the fixed mold 2B, and the mold 2 constituted by these two molds 2A and 2B is "clamped".

Next, the high speed elevating mechanism 5 will be described.
As shown in the second embodiment, the high-speed lifting mechanism 5 is a mold clamping unit that performs “clamping” of the mold 2 while leaving some clamping allowance. It is provided as a high speed molding means that performs at a speed. When the mold 2 is “clamped”, the elevating frame 4 is first lowered by the high speed elevating mechanism 5 and then switched to a high pressure elevating mechanism 6 described later at a predetermined position. The elevating frame 4 is lowered by 6.

  The high-speed elevating mechanism 5 is mainly composed of a servo motor 11 and a ball screw 12, and an output shaft 11a of the servo motor 11 and a screw member 12a of the ball screw 12 are coaxially arranged. The output shaft 11a and the ball screw 12 are connected to each other via a connecting member 13 made of a coupling or the like so as to be integrally rotatable.

  Further, in the fixed frame 3, through holes 3b and 3b penetrating the fixed frame 3 in the vertical direction are arranged at two locations (in FIG. 11, only one location) with the fixed mold 2B interposed therebetween. Description.)

  Servo motors 11 and 11 are fixed to the lower end portions of the through holes 3b and 3b so that the output shafts 11a and 11a protrude upward, and through these through holes 3b and 3b, a ball screw is provided. 12 and 12 screw members 12a and 12a are arranged so as to extend vertically upward.

  On the other hand, in the elevating frame 4, through holes 4a and 4a penetrating the elevating frame 4 in the vertical direction are arranged at two positions (in FIG. 11) equivalent to the positions where the screw members 12a and 12a are provided in plan view. Is described in only one place.), And nut members 12b and 12b of the ball screws 12 and 12 are fitted through the through holes 4a and 4a, respectively.

  Then, by inserting the upper ends of the screw members 12a and 12a into the inner diameter portions of the nut members 12b and 12b, the elevating frame 4 is moved relative to the fixed frame 3 via the plurality of elevating mechanisms 5 and 5. It is connected so that it can be moved up and down.

Next, the high pressure lifting mechanism 6 will be described.
As shown in the first embodiment, the high-pressure lifting mechanism 6 is provided as high-pressure forming means for moving the lifting frame 4 up and down, and the lifting frame 4 is moved when the mold 2 is “clamped”. This mechanism is provided as a high pressure molding means for applying a high pressure to the movable mold 2A, and is mainly configured by a hydraulic cylinder 8, a hydraulic tank 9, hydraulic control devices (not shown), and the like.

  The hydraulic cylinder 8 is a known hydraulic cylinder that is a linear motion system, and is fixed to the fixed frame 3 such that the axial center direction of the piston rod 8a of the hydraulic cylinder 8 is the vertical direction.

  That is, in the four corners of the fixed frame 3 (only one place is shown in FIG. 11), through-holes 3a, 3a,... Penetrating in the vertical direction are respectively drilled, and the through-holes 3a, 3a,. Are fitted with cylindrical bushings 10, 10... Each having a through hole 10a having a cross-sectional shape substantially equivalent to that of the piston rod 8a.

  More specifically, these bushings 10, 10... Are provided so as to extend upward from the upper surface of the fixed frame 3 through the through holes 3 a, 3 a, and the bushings 10, 10. The lower ends of the bushings 10, 10... And the back surface of the upper surface of the fixed frame 3 are located on substantially the same plane so that the lower part of the... It is fixed in this way.

  The cylinder tubes 8b, 8b... Of the hydraulic cylinders 8, 8... Are fixed to the lower ends of these bushings 10. The piston rods 8a, 8a ... of the hydraulic cylinders 8, 8 ... are inserted into the through holes 10a, 10a ... of the bushings 10, 10 ... so as to be slidable in the vertical direction. Established.

  As described above, in the hydraulic cylinders 8, 8... Provided in the plurality of high-pressure lifting mechanisms 6, 6..., The piston rods 8 a, 8 a. Each is fixed to the fixed frame 3 so as to extend. Further, the upper ends of the piston rods 8a, 8a,... Are connected to the elevating frame 4, and the elevating frame 4 is moved relative to the fixed frame 3 by moving the piston rods 8a, 8a,. It moves (moves up and down).

  These hydraulic cylinders 8, 8... Are respectively provided with hydraulic control devices such as hydraulic pumps and control valves (not shown) via piping members. The hydraulic cylinders 8, 8... Can be moved up and down sufficiently following the lifting operation of the high-speed lifting mechanisms 5 and 5 described above.

The hydraulic tank 9 is for storing hydraulic oil used by the plurality of hydraulic cylinders 8, 8... And is fixed near the center of the fixed frame 3 and a plurality of pipes. .. Are communicated with the hydraulic cylinders 8, 8... Via members 9 a, 9 a... (Only shown for one hydraulic cylinder 8 in FIG. 11).
That is, in the present embodiment, the entire casting apparatus 1 is made compact by disposing the hydraulic tank 9 inside the fixed frame 3 instead of outside the casting apparatus 1.

Next, the vibration mechanism 7 will be described.
As shown in the third embodiment, the vibration mechanism 7 is used to apply an impact force due to vertical vibration of the vibration rod 15 to the movable mold 2A when the mold 2 is “clamped”. Is.

  Note that a servo motor (not shown in FIG. 11) is employed as the drive source of the vibration mechanism 7, so that the vibration rod 15 can be controlled by changing the rotation speed of the output shaft of the servo motor. The vibration frequency in the vertical direction can be freely changed, and it is possible to easily cope with changes in casting conditions such as mold replacement and temperature changes.

  Further, by using a servo motor as the drive source of the vibration mechanism 7, the rotational position of the output shaft, that is, the rotational position of the cam plate 14 fitted to the output shaft can be easily grasped, which will be described later. As described above, the mold atmosphere control P41 can be easily performed in synchronization with the mold vibration control P51.

Next, the back pressure control device 20 will be described.
As shown in the second embodiment, the back pressure control device 20 replaces the atmosphere inside the cavity 2c (see FIG. 5) formed in the mold 2 with an inert gas (inert gas replacement control P42). ) And a device for adjusting the back pressure generated between the surface of the semi-molten metal 50 and the inner surface of the cavity 2c (back pressure control P43).

  The casting apparatus 1 in the present embodiment performs the inert gas replacement control P42 and the back pressure control P43 by the common back pressure control apparatus 20, but both these controls P42 and P43 are performed separately. It is good also as a structure performed by a pressure control apparatus.

The back pressure control device 20 has a main configuration equivalent to that in the above-described casting step W04 (second embodiment).
That is, the back pressure control device 20 includes cylinders 20a and 20a that mainly store inert gas, communication holes 2d and 2e formed in the mold 2 (in this embodiment, the fixed mold 2B), and cylinders 20a. -It is comprised by piping member 20b * 20b etc. which each connect 20a.

  As shown in the second embodiment, before the semi-molten metal 50 is put into the cavity 2c of the mold 2 (in this embodiment, into the recess 2b of the fixed mold 2B), the cylinder 20a. By blowing the inert gas stored in 20a into the communication holes 2d and 2d through the piping members 20b and 20b, the atmosphere inside the cavity 2c of the mold 2 is replaced by the inert gas. Become.

  Further, when casting the semi-molten metal 50, the inert gas stored in the cylinders 20a and 20a is further blown into the communication holes 2d and 2d, so that the surface layer surface of the semi-molten metal 50 and the cavity 2c The back pressure generated between the inner surface and the inner surface is increased, or conversely, the back pressure is reduced by returning the inert gas present in the cavity 2c into the cylinders 20a and 20a. Thus, the back pressure control device 20 is provided as a means for adjusting the back pressure of the back pressure generated in the cavity 2 c of the mold 2.

[Operation of casting apparatus 1]
Next, operation | movement at the time of performing casting process W06 with the casting apparatus 1 which consists of such a structure is demonstrated using FIG.11 and FIG.12.

  First, as shown in FIG. 11, in a state where the mold 2 is opened, that is, the lift frame 4 is stopped at a predetermined upper limit position, and the movable mold 2A is positioned vertically above the fixed mold 2B. Then, the back pressure control device 20 is activated, and the inert gas stored in the cylinders 20a and 20a passes through the piping members 20b and 20b and the communication holes 2d and 2e, and the inert gas stored in the cavities 2c (in this embodiment, The air is blown into the recess 2b of the fixed mold 2B, and the atmosphere inside the cavity 2c is replaced with an inert gas (inert gas replacement control P42).

  Here, a measuring means (not shown) for measuring the oxygen concentration is disposed inside the cavity 2c. If the measured value of the oxygen concentration by the measuring means falls below a predetermined threshold, the back pressure is measured. The operation of the control device 20 is automatically stopped or an alarm is sounded to prompt the user to insert the semi-molten metal 50 into the mold 2.

When the replacement with the inert gas inside the cavity 2c is completed and the semi-molten metal 50 is put into the mold 2, the casting process W06 starts.
In the casting process W06, first, the elevating frame 4 is lowered by the high speed elevating mechanism 5 (high speed forming process W21).

Further, when the high-speed lifting mechanism 5 is activated, the vibration mechanism 7 is activated (mold vibration control P51), and the back pressure control device 20 is also activated again, and the surface layer surface of the semi-molten metal 50, The back pressure generated between the inner surface of the cavity 2c is adjusted (back pressure control P43).
In addition, the detail regarding the control method of metal mold | die vibration control P51 and back pressure control P43 is mentioned later.

  Then, as shown in FIG. 12A, if the elevating frame 4 is lowered to a predetermined position while leaving some tightening allowance for “clamping” of the mold 2, then the high pressure elevating mechanism is continued. 6 (continuous switching to high pressure forming step W22), the vibration mechanism 7 and the back pressure control device 20 are stopped.

In addition, although it can set arbitrarily about the position (switching position) which switches from the high-speed shaping | molding process W21 to the high pressure shaping | molding process W22, in the present Example, the hydraulic cylinder 8 with which the high pressure raising / lowering mechanism 6 is equipped is maximum. The position where the output can be demonstrated.
For example, as shown in FIG. 12 (a), with respect to the switching position, the weight of the hydraulic oil filled in each of the chambers defined by the piston 8c provided at the end of the piston rod 8a in the cylinder tube 8b. It is determined by various circumstances such as balance.

  In this embodiment, the position of the lifting frame 4 is always accurately grasped by the servo motor 11 provided in the high-speed lifting mechanism 5, and the high-speed molding process from the high-speed molding process W21 to the switching position with high accuracy. Switching to W22 is to be performed.

  As the high-pressure forming process W22 proceeds, the deformation resistance (stress necessary for deforming the material) of the semi-molten metal 50 gradually increases. Further, in this case, a downward urging force by the urging means 21 is applied to the movable mold 2A on which an upward force from the semi-molten metal 50 is acting.

  Then, when the elevating frame 4 is lowered to a certain position, a reaction force directed downward by the urging means 21 disposed between the upper surface of the movable mold 2A and the lower surface of the plate-like member 19, The reaction force directed upward due to the deformation resistance is in balance with each other via the movable mold 2A.

  When the high-pressure forming step W22 further proceeds from such a state, the deformation resistance is further increased, and the movable mold 2A is in contact with the lifting frame 4 against the downward urging force by the urging means 21. Therefore, the relative position with respect to the elevating frame 4 moves in a direction approaching.

  12B, finally, the movable mold 2A is in close contact with the plate-like member 19, and the movable mold 2A is pushed downward by the plate-like member 19, so that the mold 2 "Clamping" is completed.

  When the “clamping” of the mold 2 is completed, the “clamping” state of the mold 2 is maintained for a predetermined time, and then the high-speed lifting mechanism 5 (or the high-pressure lifting mechanism 6). The elevating frame 4 is raised.

  And as shown in FIG. 11, the raising / lowering frame 4 stops at a predetermined upper limit position, and the mold 2 is in a fully open state, whereby the casting process W06 is completed and cast into an intermediate product. The semi-molten metal 50 is taken out from the mold 2.

[Control Method of Mold Excitation Control P51 and Back Pressure Control P43]
Next, control methods of the mold vibration control P51 and the back pressure control P43 will be described with reference to FIG.
First, when the high-speed forming process W21 by the high-speed lifting mechanism 5 starts, the vibration mechanism 7 also starts to operate.
Here, during the operation of the high speed elevating mechanism 5, in the servo motor 11 provided as a drive source of the high speed elevating mechanism 5, the total number of revolutions of the output shaft 11a is always detected by a built-in detector (encoder). It has become so.

That is, by grasping the moving distance of the ball screw 12 directly connected to the output shaft 11 a based on the total number of rotations of the output shaft 11 a, the vertical position of the lifting frame 4 is recognized and lifted and lowered via the vibration mechanism 7. The vertical position of the mold 2 fixed to the frame 4, that is, the movable mold 2A is recognized.
Then, by recognizing the position of the movable mold 2A in the vertical direction, the degree of cross-sectional change at a specific portion of the semi-molten metal 50 determined in advance (hereinafter referred to as “cross-sectional change amount”) is grasped. (S101).

  On the other hand, during the operation of the high-speed lifting mechanism 5, the rotation angle of the output shaft is always detected by the built-in detector (encoder) even in the servo motor provided as the drive source of the vibration mechanism 7. ing.

  That is, by grasping the rotation angle of the cam plate 14 penetrating the output shaft based on the rotation angle of the output shaft, the position of the vibration mechanism 7, that is, the vertical position of the vibration rod 15 (hereinafter simply referred to as “rotation direction”). (Denoted as “amplitude”) is recognized (S102).

  Based on the “cross-sectional change amount” of the semi-molten metal 50 and the “amplitude” of the vibration rod 15 thus grasped, it is determined whether the back pressure control device 20 is operated (ON) / stopped (OFF). (S103).

  That is, when the “cross-sectional change amount” exceeds a predetermined threshold, as described above, the liquid phase component deviates from the solid phase component due to its own weight at a specific portion of the semi-molten metal 50 and is squeezed out. (Hereinafter referred to as “divergence phenomenon”) is determined to be in a state in which it is likely to occur, and the operation (ON) of the back pressure control device 20 is permitted.

At the same time, when the “amplitude” of the vibration rod 15 is maximized (the vertical position of the vibration rod 15 is at the lower limit position), a downward impact force is applied to the semi-molten metal 50 by the vibration mechanism 7. Therefore, it is judged that the “divergence phenomenon” becomes prominent.
As a result, the back pressure control device 20 determines that it is necessary to supply an inert gas between the surface layer of the semi-molten metal 50 and the inner surface of the cavity 2c, and the back pressure control device 20 is activated (ON). ) Is allowed.

  If the operation (ON) of the back pressure control device 20 is permitted according to the respective states related to the “cross-sectional change amount” and the “amplitude”, the back pressure control device 20 is activated and the back pressure is applied. Pressure will be applied.

  On the other hand, even if the operation (ON) of the back pressure control device 20 is permitted from the state of “cross-sectional change amount”, the “amplitude” of the excitation rod 15 becomes minimum (the vertical position of the excitation rod 15 is the upper limit position). In the case of the above, it is determined that the “dissociation phenomenon” is weakened, and in order to promote the flow of the semi-molten metal 50 due to its own weight, the back pressure controller 20 causes the surface layer surface of the semi-molten metal 50, the inner surface of the cavity 2c, The inert gas existing between the two is returned into the cylinder 20a, and the back pressure is reduced (S104).

  When the “cross-sectional change amount” does not exceed a predetermined threshold, it is determined that the “dissociation phenomenon” is unlikely to occur in a specific portion of the semi-molten metal 50, and the operation of the back pressure control device 20 is performed. (ON) is not permitted, and the vehicle is stopped (OFF) (S105).

  Thus, in the casting process W06 in this embodiment, the mold atmosphere control P41 and the mold vibration control P51 in the second and third embodiments described above are simultaneously provided, and a specific portion of the semi-molten metal 50 is combined. By following the “cross-sectional change amount” in FIG. 5 and controlling the back pressure existing between the surface of the semi-molten metal 50 and the inner surface of the cavity 2c, a high-quality casting having a uniform internal structure is achieved. Trying to get a product.

That is, in this embodiment, the “cross-sectional change amount” of the semi-molten metal 50 is grasped and the operation (ON) / stop (OFF) of the back pressure control device 20 is controlled, and the “amplitude” of the vibration rod 15 is controlled. In other words, the back pressure is increased / decreased by the back pressure control device 20 by grasping the timing at which the downward impact force is applied to the movable mold 2A by the vibration mechanism 7.
In other words, based on the timing of the impact force applied to the movable mold 2A of the mold 2 and the “cross-sectional change amount” that is the degree of cross-sectional change at a predetermined portion of the semi-molten metal 50, the back pressure The back pressure generated in the cavity 2c is adjusted by adjusting the amount of the inert gas flowing into and out of the mold 2 by the control device 20.

  By adjusting the back pressure generated in the cavity 2c, in this embodiment, the “dissociation phenomenon” of the semi-molten metal 50 is effectively prevented, and a high-quality casting having a uniform internal structure is achieved. You are trying to get a product.

  As described above, the casting method according to the present embodiment is a semi-molten metal 50 casting process W02 (W04, W05) in which a solid phase component and a liquid phase component coexist as shown in the first to fourth embodiments. , Or W06), and includes the step of casting the semi-molten metal 50 into a predetermined shape by “clamping” the mold 2, and the casting step W02 (W04, W05, or W06) After the semi-molten metal 50 is put into the cavity 2c inside the mold 2, a high-speed molding process W21 as a mold clamping process for performing "clamping" of the mold 2 with some clamping margin, and the high speed After the molding process (clamping process) W21, the high-pressure molding process W22 is configured to clamp the remaining clamping margin at a higher pressure than the high-speed molding process (mold clamping process) W21.

  Further, in order to execute such a casting method, the casting apparatus in the present embodiment is a semi-molten metal 50 in which a solid phase component and a liquid phase component coexist as shown in the first to fourth embodiments. The mold 2 is embodied by the casting apparatus 1 and includes a mold 2 that casts the semi-molten metal 50 put into the cavity 2c into a predetermined shape. The mold 2 includes a fixed mold 2B and a movable mold 2A. At the same time, the movable mold 2A is moved relative to the fixed mold 2B (moving up and down), so that the mold 2 is “clamped”. A high-speed lifting mechanism 5 as a mold clamping means for performing “clamping” of the mold 2 while leaving a margin for clamping, and after the “clamping” by the high-speed lifting mechanism (mold clamping means) 5, the high-speed lifting mechanism 5 Apply pressure continuously at a higher pressure than the mechanism (clamping means) 5 , It is set to be a high-pressure elevating mechanism 6 of the remaining interference as high pressure forming means for "clamping" is provided.

  By using the casting method and casting apparatus having such a configuration, in this embodiment, the casting of a semi-molten metal having high quality and low cost is realized.

  That is, according to the present embodiment, the two-stage processes W21 and W22 of the high-speed molding process W21 in the initial stage of the casting process W02 (W04, W05, or W06) and the high-pressure molding process W22 in the latter stage are continuously performed. Therefore, even if it is a semi-molten metal with a large deformation resistance compared to the molten metal, it is possible to sufficiently secure the “flow length” for the thin part of the product (part where the cavity gap is narrow). As a result, it is possible to easily cope with casting of a thin product.

  Further, in the high-speed molding process W21, since a high-pressure load is not added to the separate mold, the entire facility can be simplified correspondingly, and the cost of the casting apparatus 1 can be reduced. It is.

  In the semi-molten metal casting method in the present embodiment, as shown in the first to fourth embodiments, the high-speed forming step (clamping step) W21 is performed at a higher speed than the high-pressure forming step W22. The mold 2 is “clamped”.

  In order to execute such a casting method, the casting apparatus according to the present embodiment is configured so that the high-speed lifting mechanism (clamping means) 5 is the high-pressure lifting mechanism as shown in the first to fourth embodiments. (High pressure molding means) The mold 2 is "clamped" at a higher speed than the high pressure molding means 6.

By using the casting method and casting apparatus having such a configuration, the high-pressure molding step W22 in the present embodiment is performed at a lower molding speed (clamping speed) than the high-speed molding step W21. The "clamping" will be performed.
Therefore, in the high pressure molding step W22, it is possible to apply a more stable high pressure to the mold 2, and a high quality cast product can be obtained.

  In the semi-molten metal casting method according to the present embodiment, as shown in the second embodiment, the atmosphere inside the cavity 2c is more inert than before the semi-molten metal 50 is introduced into the cavity 2c. In the high-speed molding step (clamping step) W21, the amount of the inert gas flowing into and out of the cavity 2c is adjusted to adjust the inner surface of the cavity 2c and the semi-molten metal 50. The back pressure generated between the surface layer and the surface layer is adjusted.

  Further, in order to execute such a casting method, the casting apparatus in the present embodiment, as shown in the second embodiment described above, puts the semi-molten metal 50 into the cavity 2c in the mold 2. Since before, a back pressure adjusting means for replacing the atmosphere inside the cavity 2c with an inert gas, that is, a back pressure control device 20, is provided, and during the execution of “clamping” by the high-speed lifting mechanism (mold clamping means) 5. The back pressure control device (back pressure adjusting means) 20 adjusts the amount of the inert gas flowing into and out of the cavity 2c, whereby the inner surface of the cavity 2c, the surface layer surface of the semi-molten metal 50, The back pressure generated during the period is adjusted.

  As described above, in the casting method and the casting apparatus according to the present embodiment, the inert gas replacement control P42 is performed before the high-speed forming step W21. Therefore, contamination such as oxidation of the semi-molten metal during casting is effectively performed. Suppressing and high quality casting products are obtained.

  Further, in the casting method and the casting apparatus of the present embodiment, the back pressure control P43 is performed in accordance with the execution of the high-speed molding step W21, so that the semi-molten metal 50 with respect to the thin portion of the product (the portion where the gap of the cavity 2c is narrow). It is possible to secure a sufficient “flow length” of the product, and to suppress a partial divergence between the liquid phase component and the solid phase component with respect to the thick part of the product (the part where the gap of the cavity 2c is wide). A simple casting product can be obtained.

  In the semi-molten metal casting method in the present embodiment, as shown in the third embodiment, the mold 2 to be “clamped” in the high-speed molding step (clamping step) W21 includes: Vibration in the direction of mold clamping and mold opening is to be applied.

  Further, in order to execute such a casting method, the casting apparatus in this embodiment is provided with a vibration mechanism 7 in the mold 2 as shown in the third embodiment, and the high-speed lifting mechanism. When the movable mold 2A is relatively moved toward the fixed mold 2B by the (clamping means) 5, the vibration mechanism 7 causes the movable mold 2B to vibrate in the mold clamping and mold opening direction. Is to be granted.

  As described above, in the casting method and the casting apparatus according to the present embodiment, the mold vibration control P51 by the vibration mechanism 7 is performed in accordance with the execution of the high-speed molding step W21. It is possible to sufficiently secure the “flow length” of the semi-molten metal 50 with respect to a portion where the gap is narrow, and a high-quality cast product can be obtained.

  In the semi-molten metal casting method in the present embodiment, as shown in the above-described fourth embodiment, the mold 2 to be “clamped” in the high-speed molding process (clamping process) W21 includes: Vibration in the mold clamping / mold opening direction is applied, and the adjustment of the back pressure is performed by adjusting the timing at which vibration in the mold clamping direction is applied to the mold 2 and a cross section at a predetermined portion of the semi-molten metal 50. The amount of the inert gas flowing into and out of the cavity 2c is adjusted based on the degree of change.

  In order to execute such a casting method, the casting apparatus in this embodiment is provided with a vibration mechanism 7 in the mold 2 as shown in the above-mentioned fourth embodiment, and the high-speed lifting mechanism. When the movable mold 2A is moved relative to the fixed mold 2B (up and down movement) by the (clamping means) 5, the movable mold 2A is clamped and opened by the vibration mechanism 7. While the vibration in the direction is applied, the adjustment of the back pressure is performed by adjusting the timing at which the vibration in the mold clamping direction is applied to the mold 2 and the degree of cross-sectional change at a predetermined portion of the semi-molten metal 50. Based on the above, the amount of the inert gas flowing into and out of the cavity 2c is adjusted.

  Thus, in the casting method in this embodiment, the mold atmosphere control P41 and the mold vibration control P51 in the second and third embodiments described above are simultaneously provided, and a specific portion of the semi-molten metal 50 is provided. In order to control the back pressure existing between the surface of the semi-molten metal 50 and the inner surface of the cavity 2c in accordance with the degree of cross-sectional change, a high-quality cast product having a uniform internal structure is obtained. You can get it.

DESCRIPTION OF SYMBOLS 1 Casting apparatus 2 Mold 2A Movable mold 2B Fixed mold 2a Cavity 5 High-speed raising / lowering mechanism (clamping means)
6 High pressure lifting mechanism (high pressure molding means)
7 Excitation mechanism 20 Back pressure control device (back pressure adjusting means)
50 Semi-molten metal W02 Casting process W04 Casting process W05 Casting process W06 Casting process W21 High-speed molding process (Clamping process)
W22 High pressure molding process

Claims (10)

A semi-molten metal casting method in which a solid phase component and a liquid phase component coexist,
It includes a step of casting a semi-molten metal into a predetermined shape by “clamping” the mold,
The process includes
After the semi-molten metal is introduced into the cavity inside the mold, a mold clamping process for performing “clamping” of the mold leaving some clamping allowance;
After the end of the mold clamping step, a high pressure molding step of clamping the remaining clamping allowance at a higher pressure than the mold clamping step;
Composed of,
A method for casting a semi-molten metal. The semi-molten metal casting method according to claim 1, wherein the mold clamping process performs “mold clamping” of the mold at a higher speed than the high-pressure molding process. The atmosphere inside the cavity is replaced with an inert gas before the semi-molten metal is introduced into the cavity,
In the mold clamping step, the back pressure generated between the inner surface of the cavity and the surface layer of the semi-molten metal is adjusted by adjusting the amount of the inert gas flowing into and out of the cavity. ,
The semi-molten metal casting method according to claim 1, wherein the semi-molten metal is cast. In the mold clamping step,
The mold to be “clamped” is subjected to vibration in the mold clamping and mold opening direction.
The semi-molten metal casting method according to claim 1, wherein the semi-molten metal is cast. In the mold clamping step,
The mold to be “clamped” is subjected to vibration in the mold clamping and mold opening direction,
The adjustment of the back pressure is as follows:
Timing at which vibration in the mold clamping direction is applied to the mold;
The degree of cross-sectional change at a predetermined site of the semi-molten metal;
The amount of the inert gas flowing into and out of the cavity is adjusted,
The semi-molten metal casting method according to claim 3, wherein: A semi-molten metal casting apparatus in which a solid phase component and a liquid phase component coexist,
A mold for casting the semi-molten metal charged into the cavity into a predetermined shape is provided.
The mold is composed of a fixed mold and a movable mold,
The mold is “clamped” by the relative movement of the movable mold toward the fixed mold,
In the movable mold,
Clamping means for performing “clamping” of the mold while leaving some clamping margin;
High pressure molding means for "clamping" the remaining clamping allowance while continuously applying pressure at a higher pressure than the mold clamping means after completion of "mold clamping" by the mold clamping means;
Is provided,
A semi-molten metal casting apparatus. The semi-molten metal casting apparatus according to claim 6, wherein the mold clamping unit performs “clamping” of the mold at a higher speed than the high-pressure molding unit. In the mold,
Before the semi-molten metal is charged into the cavity, back pressure adjusting means for replacing the atmosphere inside the cavity with an inert gas is provided,
During the execution of “clamping” by the mold clamping unit, the back pressure adjusting unit adjusts the amount of the inert gas flowing into and out of the cavity to thereby adjust the inner surface of the cavity and the semi-molten metal. Adjusting the back pressure generated between the surface and the surface,
The semi-molten metal casting apparatus according to claim 6, wherein the apparatus is a semi-molten metal casting apparatus. The mold is provided with a vibration mechanism,
When the movable mold is relatively moved toward the fixed mold by the mold clamping means, vibration is applied to the movable mold by the vibration mechanism in the mold clamping / mold opening direction.
The semi-molten metal casting apparatus according to claim 6, wherein the apparatus is a semi-molten metal casting apparatus. The mold is provided with a vibration mechanism,
When the movable mold is relatively moved toward the fixed mold by the mold clamping means, vibration is applied to the movable mold by the vibration mechanism in the mold clamping / mold opening direction,
The adjustment of the back pressure is as follows:
Timing at which vibration in the mold clamping direction is applied to the mold;
The degree of cross-sectional change at a predetermined site of the semi-molten metal;
The amount of the inert gas flowing into and out of the cavity is adjusted,
The semi-molten metal casting apparatus according to claim 8, wherein:

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