WO2004002658A1

WO2004002658A1 - Method and device for vacuum die casting of aluminum alloy, and aluminum alloy product

Info

Publication number: WO2004002658A1
Application number: PCT/JP2003/008072
Authority: WO
Inventors: Hirotaka Kurita; Hiroshi Yamagata; Toshikatsu Koike
Original assignee: Yamaha Hatsudoki Kabushiki Kaisha
Priority date: 2002-06-26
Filing date: 2003-06-26
Publication date: 2004-01-08
Also published as: AU2003244075A1; JP4224024B2; JPWO2004002658A1

Abstract

A method for vacuum die casting of an aluminum alloy, comprising the steps of forming a cavity formed by fitting, to each other, a plurality of metal molds having first and second metal molds movable relative to each other in one direction and slide metal molds held between the first and second metal molds and movable relative to each other in a direction different from the one direction so that the entire or a part of the peripheral edge of the mating faces of the metal molds can be covered by a cover part through a space, depressurizing the inside of the cavity by starting evacuation according to the forward movement of a plunger tip at a low speed, depressurizing the space between the cover part and the metal molds to increase the degree of vacuum, and moving the plunger tip at a high speed when molten metal reaches near the inlet of the cavity to feed the molten metal into the cavity at a high speed while controlling the flow of cooling water into the metal molds.

Description

Description Vacuum die-casting method and apparatus for aluminum alloy and aluminum alloy product

The present invention relates to an aluminum alloy vacuum die casting method and apparatus, and to an aluminum alloy product such as a cylinder opening of a cylinder of an engine. Background art

As the cylinder block structure of the engine, a cylinder bore with a piston on the sliding surface of the piston or a bore surface coated with Ni to enhance wear resistance and strength during high-temperature sliding has been adopted. ing.

On the other hand, a direct-sliding type cylinder block that forms a sliding surface with machined parts without using such a sleeve or Ni plating can simplify the manufacturing process and cool down. It is thought that the capacity will be improved and the cost will be reduced. As such a direct-sliding type cylinder block, a cylinder block made of a single material of a hypereutectic A 1 (aluminum) —Si (silicon) alloy has been put to practical use.

However, the conventional direct-sliding type cylinder block made of a single material of A1-Si alloy is formed by low-pressure fabrication, which requires a long fabrication time, lowers productivity and reduces costs. Disadvantageous.

In addition, since low-pressure sintering requires a long manufacturing time, the A1-Si alloy for low-pressure sintering has a reduced Fe content to avoid formation of a coarse compound phase during cooling. . Fe prevents seizure with the mold and has an effect, but low pressure In the structure, seizure does not occur because the ceramic coating is performed repeatedly. However, when the cylinder block is manufactured by the ordinary high-pressure and high-speed die-casting method using this low-pressure A1-Si alloy, seizure due to insufficient Fe becomes a problem.

On the other hand, ordinary A 1 —Si alloys for high-pressure die casting have a low Si content that enhances wear resistance. In low-pressure production, the cooling rate is slow, so even if the Si content is small, the Si crystals grow sufficiently and the grain size increases, and sufficient wear resistance can be obtained.However, in the high-pressure die-casting method, cooling is performed. Due to the high speed, the Si crystal does not grow sufficiently large, and the required wear resistance cannot be obtained.

Furthermore, in the direct sliding cylinder block, the aluminum alloy itself forms the sliding surface of the bore, so that defects such as voids must be minimized. In order to eliminate defects such as cavities, it is necessary to remove gases (hydrogen, air or mold release materials, carbon-based gas generated from lubricants, etc.) from the cavities during fabrication. To this end, the gas in the mold cavity is evacuated with a vacuum pump with the gap between the mold mating surfaces, etc., when the mold (fixed mold and movable mold) is assembled during production, sealed. A method was used to carry out construction. However, even when manufacturing while performing vacuum evacuation (decompression), if a thin and complicated part such as the air-cooled fin of an air-cooled cylinder is to be formed, a slide die is used for that part. In addition to the mating surface between the fixed mold and the movable mold, a gap is formed on the sliding surface of the slide mold, and the sealing performance is reduced, so that a sufficient degree of vacuum cannot be obtained, and the gas can be reliably removed. Could not

多い If there is a large amount of gas in the manufactured product, pores and blisters called blisters occur during heat treatment and welding, so heat treatment and welding could not be performed with conventional high-pressure die casting.

The present invention has been made in consideration of the above-mentioned conventional technology, It is an object of the present invention to provide a method and apparatus for vacuum die casting of an aluminum alloy which can ensure sufficient wear resistance and seizure resistance at a low cost, and an aluminum alloy product such as an engine cylinder block piston. Disclosure of the invention

In order to achieve the above object, according to the present invention, a first mold and a second mold that can move relative to each other in one direction, and are sandwiched between the first mold and the second mold in a direction different from the one direction. Aluminum comprising: a step of forming a cavity by combining a plurality of movable slide dies; a step of depressurizing the inside of the cavity; and a step of supplying a molten aluminum alloy into the cavity. An alloy vacuum vacuum casting method, wherein the step of forming the cavity additionally includes a step of covering a whole or a part of a periphery of a mating surface of the dies with a cover via a space. Then, following the forward movement of the plunger tip at a low speed, the vacuum evacuation is started to reduce the pressure in the cavity, and the space between the cover part and the mold is reduced. Process To gradually increase the degree of vacuum, and when the molten metal reaches the vicinity of the cavity inlet, move the plunger tip at high speed to rapidly supply the molten metal into the cavity and adjust the flow rate of cooling water to the mold during this time The present invention provides a vacuum die casting method for an aluminum alloy, which is characterized in that:

According to this configuration, since the mating surface of the mold is covered with a part of the cover, the cavity in the mold can be depressurized without applying a sealing material to the mating surface of the mold itself. Even if the mold structure is such that the sealing performance of the mold, the mating surface of the slide mold, etc., the sliding surface is likely to be uncertain, the mold itself is sealed with a cover that covers it without applying a seal. By reducing the pressure, the degree of vacuum in the cavity in the mold can be sufficiently increased, and the gas can be reliably removed to eliminate the occurrence of voids, and welding and heat treatment can be performed. You can get toys.

In this case, if a seal material is provided on the mating surface between the movable side and the fixed side part of the cover, the seal material is provided at a position separated from the high-temperature mold by a space. The thermal effect of the sealing material is reduced, the deterioration of the sealing material is prevented, and high sealing performance is maintained. In addition, since the step of decompressing the cavity and the step of depressurizing the space between the cover part and the mold are performed, the mold is depressurized by depressurizing the space between the cover part and the mold. In addition to directly reducing the pressure of the cavity, the cavity in the mold can be depressurized through the gap between the peripheral surfaces of the mold mating surface. Gas can be reliably discharged. This makes it possible to improve the flow of hot water into the cavity and to obtain a high-quality die-cast product with no molten metal, even in a cavity for forming a thin wall, in which the molten metal is surely filled in every corner. '

In a preferred configuration example, the step of forming the cavity and the step of covering the whole or a part of the periphery of the mating surface of the molds with a cover via a space are performed simultaneously.

According to this configuration, the mold is covered with a part of the cover at the same time as the mold is formed by combining the molds, thereby increasing the manufacturing cycle time by increasing the step of covering the mold with the part of the cover. I can't.

In a preferred configuration example, after the step of forming the cavity, a step of covering the whole or a part of the periphery of the mating surface of the molds via a space is performed.

According to this configuration, the step of covering with a part of the cover is performed after confirming the mold clamping, so that the reliability of space formation and sealing is improved.

In a preferred configuration example, the step of depressurizing the inside of the cavity and the step of depressurizing the space between the cover part and the mold are performed almost simultaneously. It is characterized by. -According to this configuration, the space between the cover part and the mold is decompressed almost simultaneously with the decompression inside the cavity, so the structure by increasing the process of decompressing the space between the cover and the mold is increased. Cycle time does not increase. In a preferred configuration example, the step of depressurizing the inside of the cavity and the step of depressurizing the space between the cover part and the mold are performed with a time lag.

According to this configuration, the evacuation time of the space and the evacuation time of the cavity are shifted in consideration of the intricate shape of the slide die and the exhaust passage resistance, so that the vacuum evacuation can be efficiently performed in order for the entire die. By doing so, the gas in the cavity can be exhausted reliably.

In a preferred configuration example, before the step of depressurizing the inside of the cavity, a step of depressurizing a space between the cover portion and the mold is performed.

According to this configuration, since the space is evacuated prior to the inside of the cavity, the liquid release agent adhering to the gap between the mating surface of the mold and the sliding surface of the slide mold is removed. It is sucked directly into the space 33 without being sucked inside. For this reason, it is prevented that an excessive release agent flows into the cavity and mixes with the molten metal to cause a defect in a cavity or the like.

In a preferred configuration example, the aluminum alloy contains Fe, and contains 18 to 22 wt% of Si.

According to this configuration, since 18 to 22 wt% of Si is contained in the aluminum alloy, sufficient Si particles can be obtained even when manufactured by the high-pressure die-casting method with a high cooling rate. The abrasion resistance is enhanced. If it is less than 18%, when produced by the high-pressure die-casting method, the Si particles do not become large and sufficient wear resistance cannot be obtained. At 22% or more, it becomes brittle and wear resistant Lower. Further, such moderate Si crystallizes on the surface during the manufacturing process, and prevents seizure with the mold.

In a preferred configuration example, the aluminum alloy contains Fe in a range of 0.4 to 1.5 wt%.

According to this configuration, since 0.4 to 1.5% of Fe is contained in the aluminum alloy, seizure with the mold is prevented when the aluminum alloy is manufactured by the high-pressure die casting method. In this case, the seizure prevention effect is further enhanced in combination with the seizure prevention effect of Si. If 6 is less than 0.4%, seizure cannot be sufficiently prevented. On the other hand, if the content is 1.5% or more, the intermetallic compound generated between Fe and A1 grows large in the metal structure to become coarse needle-like crystals, and becomes brittle, resulting in reduced elongation.

A preferred configuration example is characterized by including a step of rapidly cooling the structure taken out of the mold.

According to this configuration, by temporarily cooling the die-cast structure taken out of the mold, for example, compounds such as Cu and Mg are uniformly dispersed, and a uniform and stable strength can be obtained in place. Here, rapid cooling is represented by water-cooling quenching treatment, but is not limited to water cooling, but includes all cooling methods other than natural cooling, in which the product is actively cooled.

In a preferred configuration example, the aluminum alloy is manufactured by the vacuum die casting method of an aluminum alloy according to the method of the present invention.

As described above, by producing an aluminum alloy product by the method of the present invention, the production of voids is suppressed, and a high-quality product that can be welded and heat-treated is obtained.

In a preferred configuration example, the aluminum alloy product is a cylinder plug or a piston of an engine. According to this application example, it is possible to produce a high-quality cylinder block or biston by using a low-cost high-pressure die-casting method, which can be welded and heat-treated without voids. The cylinder block is a cylinder portion of the engine including the cylinder bore, and includes a case where the crankcase and a part of the cylinder head are integrally formed. The piston is fitted with a piston that slides in the cylinder bore.

In a preferred configuration example, the aluminum alloy product is a cylinder block of an engine, wherein silicon crystals protrude from a surface of a cylinder bore.

According to this configuration, since the Si crystal particles are raised and protruded from the aluminum base material surface of the cylinder bore made of the aluminum alloy, the raised Si crystal particles contact the piston and form a sliding surface. The lubricating oil spreads on the surface of the concave aluminum base material around it, and a stable and highly wear-resistant cylinder block can be obtained.

Further, in the present invention, the first and second molds that can move relative to each other in one direction, and the slide that is sandwiched between the first and second molds and that can move relatively in a direction different from the one direction. A plurality of molds are combined to form a cavity, and the inside of the cavity is depressurized by a vacuum pump to supply a molten aluminum alloy into the cavity. In the first and second molds, a part of the cover is provided integrally with that of the first and second molds, and at the time of forming the cavity, the parts of the cover come into contact with each other via a sealing material to form a mating surface between the molds. And a vacuum pipe connecting the cavity and the space to a vacuum pump is provided. The vacuum evacuation is started in conjunction with the forward movement of the furnace, and the pressure in the cavity and the space is reduced through the vacuum pipe. When the plunger tip is moved near the inlet of the tee, the molten metal is rapidly supplied into the cavity, and the flow rate of cooling water to the mold is adjusted during this time. According to this configuration, since the mating surface of the mold is covered with a part of the cover, the inside of the part of the mold is suctioned and evacuated by the vacuum pump without applying a sealing material to the mating surface of the mold itself. The cavity inside the mold can be decompressed, and even if the mold has a complicated shape, the sealing surface of the sliding mold, etc. By sealing the mold with a part of the cover that covers the mold without applying a seal and reducing the pressure, the vacuum in the mold cavity can be sufficiently increased, and the gas can be reliably removed. Welding and nesting are eliminated Can be processed can be obtained a high-quality die cast 錶造 products.

In a preferred configuration example, the part of the cover covers the entire periphery of the mating surface of the dies through a space and is separately fixed to the first and second dies.

According to this configuration, since the cover portion is separate, the present invention can be implemented using an existing mold.

In a preferred configuration example, the part of the cover covers the entire periphery of the mating surface of the dies through a space, and is formed integrally with the first and second dies.

According to this configuration, since the part of the cover and the mold are integrated, parts for attaching the part of the cover are not required, and the number of parts is reduced and the configuration is simplified. In a preferred configuration example, the cover portion has a mounting portion for mounting an actuator for driving at least a part of the molds. According to this configuration, the mold can be driven by attaching the actuator to the force bar side, and the configuration of the mold is simplified, and the degree of freedom in layout is increased.

In a preferred configuration example, a fixing portion for fixing the cover portion to the mold is formed on an inner surface of the cover portion.

According to this configuration, the cover part is fixed to the mold on the inner surface side of the force part, so that the outer shape of the cover part is simplified, and the mounting bolts and the like do not protrude to the outside. The structure is simple.

In a preferred configuration example, the other end of the vacuum pipe connected to a common vacuum pump is connected to the space, and the cavity is connected to the vacuum pump via the space.

According to this configuration, it is possible to simplify the configuration by using a common vacuum pump and vacuum piping, and to efficiently evacuate the cavity through a space.o

In a preferred configuration example, the cavity is connected to a common vacuum pump without passing through the space.

According to this configuration, the configuration can be simplified using the common vacuum pump, and the space and the cavity can be evacuated with separate pipes, so that the interior of the cavity can be evacuated efficiently and reliably.

In a preferred configuration example, the cavity and the space are connected to a vacuum pump of another system via a vacuum pipe of another path.

According to this configuration, by evacuating the space and the cavity with another vacuum pipe and another vacuum pump, a separate vacuum system is provided in consideration of the configuration of the space, the exhaust resistance, etc., and the interior of the cavity is evacuated. Evacuation can be performed efficiently and reliably. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is an explanatory diagram of a flow of a manufacturing process according to the present invention.

FIG. 2 is a configuration diagram of the fabrication device according to the present invention.

FIG. 3 is a time chart of a manufacturing process by the manufacturing apparatus of FIG. FIG. 4 is a configuration diagram of a fabrication device according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of the third embodiment of the present invention.

FIG. 6 is a configuration diagram of a fourth embodiment of the present invention.

FIG. 7 is a configuration diagram of a fifth embodiment of the present invention.

FIG. 8 is a configuration diagram of a movable mold according to a sixth embodiment of the present invention.

FIG. 9 is a configuration diagram of a fixed type paired with the movable type of FIG.

FIG. 10 is a configuration diagram of a movable mold according to the seventh embodiment of the present invention.

FIG. 11 is a configuration diagram of a fixed type that is paired with the movable type of FIG.

FIG. 12 is an explanatory view of a honing step in a fabrication process according to the present invention.

FIG. 13 is a top view of a cylinder block according to another embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION ''

Table 1 is a table showing material components of the Al—Si alloy according to the present invention. 【table 1】

Ni Sn Ca Na P Al

0.1 or less 0.1 or less 0.01 or less 0.01 or less 100 PPHfiiiJh Remaining t This aluminum alloy is formed by melting the base metal of a reclaimed aluminum alloy base. However, it can also be formed from new lump-based ingots using new aluminum metal. Using such an aluminum alloy, a cylinder block of the engine is formed by die casting described later. In the table, Si increases the wear resistance of the sliding surface of the cylinder bore, and also improves the seizure resistance in the manufacturing process. Fe is added to prevent seizure with the mold. Cu and Mg increase the base metal strength by heat treatment. Mn, Zn, Ni, Sn, Ca, and Na are impurities originally contained in recycled aluminum. P is added to make the particle size and dispersion of Si particles uniform.

Figure 1 shows the die casting process using the aluminum alloys in Table 1.

Dissolution process S 1:

A metal of aluminum alloy having a predetermined alloy composition is melted in a melting furnace to form a molten metal. In order to prevent undissolved Si from remaining in the melt, the melt is heated to a certain temperature or higher. When the metal is completely melted, the temperature of the molten metal is kept at a predetermined temperature equal to or lower than the above-mentioned superheat temperature. In this melting step, add about 100 pDm of P to the metal or molten metal before melting. Good. As a result, the Si particles in the alloy are uniformly dispersed.

錶 Structural process S 2:

Performed by high pressure die casting. In this case, the mold set in the cover described later is manufactured while reducing the pressure. By using this cover to reduce the pressure, even if the mold has many slide molds, the entire mold is suctioned and evacuated to increase the degree of vacuum inside the mold without setting a seal on the mold itself. The gas can be reliably removed to prevent the occurrence of nests.

Heat treatment step S3:

後 T5, T6 or T7 heat treatment is applied to the cylinder block removed from the mold after fabrication. In the T5 treatment, immediately after the mirror product is removed from the mold, it is quenched by water cooling or the like, and then artificially aged for a predetermined time at a predetermined temperature and then air-cooled to improve mechanical properties and dimensional stability. It is. The T6 treatment is a process of taking out a manufactured product from a mold, performing a solution treatment at a predetermined temperature for a predetermined time, cooling with water, then performing an artificial aging process at a predetermined temperature for a predetermined time, and then air cooling. The T7 treatment is a treatment for overaging as compared with the T6 treatment, and dimensional stabilization is achieved, but hardness is lower than T6 treatment.

Machining process S4:

Processing such as grinding and turning of the mating surface with the cylinder head, the mating surface with the crankcase, and the inner surface of the cylinder bore.

Honing process S5:

Honing the inner surface of the cylinder bore. This honing is performed in three steps: (1) rough honing, (2) semi-finishing honing, and (3) finishing honing, as described later (Fig. 12).

FIG. 2 is a configuration diagram of a fabrication device used in the fabrication process S2.

The mold 1 includes a fixed mold 2 and a movable mold 3, and the movable mold 3 includes a base mold 4 and a slide mold 5. Note that the fixed mold 2 and the base mold 4 Either one of the first mold and the second mold and the other mold described in the paragraph. The slide mold 5 is divided into four at 90-degree intervals, each of which is provided with a cylinder 6 (only the upper and lower parts are shown), and the surface of the base mold 4 (between the base mold 4 and the slide mold 5). Along the mating surface 30), slide as shown by the arrow A, and form the cavity 7 of the cylinder block at the center during mirror fabrication. The cylinder 6 is an actuator for driving a slide mold described in the claims. 7a and 7b are cylinder bore forming parts, and 7c is an air cooling fin forming part. The base mold 4 is provided with an extrusion pin 8 ′, and for each construction shot, the construction is extruded with the slide mold 5 opened to be taken out of the mold. 3 1 is a mating surface between the fixed mold 2 and the movable mold 3.

The stationary mold 2 is provided with an injection sleeve 9. The plunger tip 11 provided at the tip of the port 10 in the injection sleeve 9 reciprocates. A hot water supply port 12 is formed in the injection sleeve 9, and one shot of molten metal is injected with the plunger tip 11 in the original position (position behind the hot water supply port 12 (right side in the figure)). I do. A chip sensor 13 is provided in front of the hot water supply port 12. The tip sensor 13 is for detecting that the plunger tip 11 has passed through the hot water supply port 12.

The whole mold 1 is covered with a part 14 of a hippopotamus. The cover part 14 is composed of a fixed-side cover part 14 a that houses the fixed mold 2 and a movable-side cover part 14 b that houses the movable mold 3. 5 is attached ο

In the gap between each of the cylinder 6, the extrusion pin 8, and the injection sleeve 9, which penetrates the cover 14, and the cover 14, a sealing material 15 such as an O-ring is attached. Keep the airtight inside. A leak valve 16 is provided on the movable side cover 14 b (or a part of the fixed side cover 14 a) of the cover 14. An exhaust passage 17 communicating with the cavity 7 is formed in the fixed mold 2. The exhaust passage 17 may be formed on the movable mold side. The exhaust passage 17 has a bypass passage 17a, and an on / off valve 18 for opening and closing the bypass passage 1a. By-pass passage 1 Ίa is used to bypass the exhaust passage 17 where the on / off valve 18 is installed and vacuum the exhaust passage 17 when vacuuming the inside of the mold during manufacturing (as shown). This is for communication with the outside of the mold. The on / off valve 18 is, for example, a metal switch valve. When the molten metal is filled in the cavity and the remaining molten metal rises through the exhaust passage 17, when the molten metal contacts the on / off valve 18, This is pushed up to close the bypass passage 17a together with the exhaust passage 17 to prevent the molten metal from being blown out of the mold. Instead of such a metal valve, a valve configuration that detects the position of the plunger tip 11 and closes the exhaust passage 17 via the actuator at the position where one shot of molten metal has been pushed in is completed. Is also good. In addition, as a means to prevent such molten metal from escaping, a zigzag long narrow passage communicating with the cavity is formed, and the molten metal overflowing from the cavity is solidified in the middle by passing through this passage. A chill vent structure for preventing outflow to the outside may be used. One or more (two in this example) vacuum pipes 20 communicating with the vacuum tank 19 are connected to the cover part 14 (in this example, the fixed-side cover part 14a). The vacuum tank 19 is maintained at a predetermined vacuum pressure by a vacuum pump 21. The vacuum pump 21 is controlled to be turned on and off by the control device 22 at the start and end timings of the cavity depressurization based on the detection signal of the stroke position of the plunger tip 11 or the evening signal of the stroke time.

In addition, a part of the cover 14 covers the entire mold 1, but locally (for example, the outer periphery of the mold 1 is connected along the peripheral edges 30 a and 3 la of the mating surface 30.3 1). May be covered). Further, a cover part 14 having a shape covering the cylinder 6 for driving the slide die 5 may be provided (see FIGS. 6 and 7). In this way, the cover part 14 covering the mold 1 is provided, and the cover part 14 is evacuated to vacuum and the inside of the cavity 7 is depressurized to produce the slide mold 5 in many cases. Even in the case of vacuum, vacuum is applied to the entire mold without applying a seal to the mold itself, and the cavity is also suctioned through the gap between the mating surfaces 30 and 31 to increase the degree of vacuum. As a result, gas can be reliably removed from the mold. In addition, the sealing material 15 on the mating surface of the fixed cover part 14a of the cover part 14 and the movable cover part 14b is mounted at a position separated from the high-temperature mold 1, so that thermal When the influence is reduced, deterioration of the sealing material is prevented and durability is improved.

In the figure, the cooling water flow rate adjusting unit 60 controls the cooling of the mold 1 in the manufacturing process as shown in the figure. For example, the timing of high-speed injection by the plunger tip 11 (see FIG. 3) At t 2), a valve (not shown) can be opened and a timer can be used to flow cooling water for a certain period of time. This — the fixed time is, for example, the time it takes for the product to be taken out by mold separation. At this time, the cooling effect may be confirmed by monitoring the cooling water temperature or the mold temperature using a temperature sensor. Alternatively, feedback control can be performed by a temperature sensor. If cooling is insufficient, it takes a long time for the whole to solidify, and the unsolidified part is pulled by the solidified part, making it easier for nests to form. Conversely, if the cooling is too high, the solidification rate increases, the Si precipitation decreases, and the wear resistance decreases.

FIG. 3 is a time chart showing the degree of vacuum in the mold when the fabrication step S2 in FIG. 1 is performed using the mold 1 having the cover part 14 in FIG. 2 described above. The horizontal axis indicates time, and the vertical axis indicates the degree of vacuum.

First, slide mold 5 of mold 1 shown in FIG. 2 is placed at a predetermined position. W

1 6 Form the cavity 7, butch the movable mold 3 against the fixed mold 2 and clamp it. At this time, the mating surfaces 3 2 of the fixed side cover part 14 a of the cover part 14 and the movable side part 14 b abut against each other via the sealing material 15, and the inside of the cover part 14 is sealed. Is done. That is, a mold clamping step of forming the cavity 7 by combining the fixed mold 2 and the movable mold 3 and a sealing step of covering and sealing the mold 1 with the cover 14 are simultaneously performed. As a result, the manufacturing cycle time can be reduced. After the fixed mold 2 and the movable mold 3 are clamped to form the cavity, the mold 1 can be covered with a cover part 14 and sealed.

Time t 0: The plunger tip 11 is at the original position (behind the hot water supply port 12), the hot water supply port 12 is open, and the inside of the mold 1 is large through this hot water supply port 12. Atmospheric pressure. In this state, 1 shot of the aluminum alloy melt is injected from the hot water supply port 12. When the molten metal is injected, move the plunger tip 1 1 forward at a low speed and push the molten metal in the injection sleeve 9. Time t 1: Chip sensor 13 (FIG. 2) detects plunger tip 11. In this state, since the plunger tip 11 is located in front of the hot water supply port 12, the inside of the cover part 14 is completely hermetically sealed. At this point, the vacuum pump 21 is driven to evacuate the cover 14.

By this evacuation, the space 33 between the mold 1 and the cover part 14 and the evacuation of the cavity 7 are simultaneously performed. As a result, the depressurization process is performed efficiently, and the cycle time of manufacturing is reduced. The vacuum evacuation path of the cavity 7 and the vacuum evacuation path of the space 33 between the mold 1 and the cover part 14 can be separately evacuated and evacuated at different times. In particular, if the space is evacuated prior to the cavity, the liquid release agent adhering to the gap between the mating surface of the mold and the sliding surface of the slide mold will be sucked into the cavity. Is sucked directly into the space 3 3 without Therefore, it is possible to prevent the excessive release agent from flowing into the cavity and mixing with the molten metal, thereby causing defects in the cavity and the like.

The pressure in the cavity 7 in the mold 1 is reduced by the suction process by the vacuum evacuation, and the degree of vacuum gradually increases. The plunger tip 1 1 continues to move forward at low speed, pushing the molten metal into the cavity. By starting evacuation after the plunger tip 11 has passed over the hot water supply port 12, it is possible to prevent air from being sucked into the mold through the hot water supply port 12. As a result, the formation of cavities is more reliably prevented, and local cooling of the molten metal surface by air is prevented, whereby a product having uniform and stable quality can be obtained. Time t 2: When the molten metal reaches the cavity entrance, the plunger 11 is switched from low speed to high speed, and the molten metal is rapidly supplied into the cavity. Time t 3: The cavity is completely filled with the molten metal and injection is completed. At this time, the molten metal pushes up the on / off valve 18 (FIG. 2) of the exhaust passage 17 to prevent the molten metal from being ejected from the exhaust passage 17.

Time t 4: The vacuum pump 21 is stopped to end the decompression by evacuation. At this point, the inside of the hippo part 14 is still in a decompressed state.

Time t 5: Open the leak valve 16 and open the inside of the cover 14 to the atmosphere. A part of the force bar approaches the atmospheric pressure with time through the leak valve 16. Time t 6: The inside of the hippo part 14 returns completely to atmospheric pressure. At this point, open the mold and remove the product. By opening the cover part 14 together with the mold after returning to atmospheric pressure, the ring attached to the mating surface 32 of the cover is prevented from falling off.

Instead of turning on / off the vacuum pump 21 itself, the vacuum pump may be constantly turned on, and the timing of evacuation may be controlled by turning on / off the electromagnetic valve 61 provided on the vacuum pipe.

For example, when the chip sensor 13 detects the plunger chip 11 ( Open the solenoid valve at t 1). Then, at the end of injection, for example, when the sensor (for example, a mouth sensor for detecting the position of the rod of the plunger tip) detects that the plunger tip has reached the leading end position of the stroke, the electromagnetic valve is closed (t 4). . The opening / closing timing of this electromagnetic valve can be made variable by making the position of the chip sensor 13 ゃ rod sensor adjustable back and forth.

FIG. 4 is a configuration diagram of a fabrication device according to a second embodiment of the present invention. The manufacturing apparatus of this embodiment is different from the embodiment of FIG. 2 in that a lid 23 is provided on a hot water supply port 12. The lid 23 is closed around the hot water supply port 12 via a sealing material (not shown). In this case, since the inside of the cover part 14 is evacuated to a vacuum, the pressure in the injection sleep 9 is reduced. This negative pressure sucks the lid 23 and securely seals the hot water supply port 12. Therefore, the lid 23 is closed immediately after the molten metal is poured from the hot water supply port 12, and the pressure can be started from that point.

Reference numeral 24 denotes a lid sensor which detects that the hot water supply port 12 is closed by the lid 23 and sends a detection signal to the control device 22. When the detection signal of the lid 23 is input, the control device 22 drives the vacuum pump 21 immediately to reduce the pressure in the cover 14.

By providing such a lid 23, evacuation can be started without waiting for the plunger tip 11 to cross the hot water supply port 12, and the decompression time can be reduced even when the injection sleeve 9 is short. Prolong it to obtain a sufficient degree of vacuum. The other configurations, functions, and effects are the same as those in the example of FIG.

This embodiment shows a die casting device for producing a piston in place of the above-mentioned cylinder block. A cavity 34 for biston is formed between the fixed mold 2 and the movable mold 3. Fixed type 2 Empty inside the biston on the side A convex portion 36 for the sinus is formed. The protrusions 35 for the biston pins are formed on the upper and lower slide dies 5. Other features and effects are the same as those of the embodiment of FIG. 2 described above.

In this embodiment, the cover part 14 is integrally formed with the mold 1. A fixed cover part 14 a is molded into the fixed mold 2, and a part 14 b of the movable cover is molded into the base mold 4 of the movable mold 3. A part 14 a of the fixed side cover and a part 14 b of the movable side are hermetically sealed with a mating surface 32 via a sealing material 15, so that a space 33 is formed between the part 1 a and the mold 1. In this example, the cover part 14 is formed so as to cover a cylinder 6 that drives the slide mold 5. The other configuration and operation and effect are the same as those in the above-described example of FIG.

In this embodiment, the cover part 14 is formed separately from the mold 1, the fixed cover part 14 a is attached to the fixed mold 2, and the movable cover part 14 b is attached to the movable mold 3. Each of them is attached to a metal mold 4 via a sealing material 15. The cover part 14 is formed so as to cover the periphery 30 a and 31 a of the mating surface 30 of the base mold 4 and the slide mold 5 and the mating surface 31 of the fixed mold 2 and the movable mold 3. You. The exhaust passage 17 communicating with the cavity 7 is sucked and evacuated from the outside of the cover 14 through a vacuum pipe 37 different from the space 33 in the cover 14. An electromagnetic valve 62 is provided on the vacuum pipe 37 similarly to the vacuum pipe 20. By controlling the opening and closing of the solenoid valve 62 of the vacuum pipe 37 and the solenoid valve 61 of the vacuum pipe 20 while the vacuum pump 21 is driven, the vacuum exhaust timing of the space 33 and the cavity 7 is shifted. Can be done.

This vacuum pipe 37 may be connected to the vacuum pipe 20 of the cover part 14 and decompressed by the same vacuum pump 21 or connected to a vacuum pump of another system. You may. In addition, the exhaust passage 17 may be opened in the space 33 of the cover part 14 and the pressure may be reduced by the same vacuum pipe 20 as in the example of FIG. The other configurations, functions, and effects are the same as those in the above-described example of FIG.

FIGS. 8A and 8B show a movable die of a die casting apparatus according to a sixth embodiment of the present invention, wherein FIG. 8A is a longitudinal sectional view at the center, and FIG. Note that parts corresponding to those in the above-described embodiment such as FIG. 2 are given the same numbers.

The movable mold 3 includes a base mold 4 and four slide molds 5 in the cross direction. A splitter 39 is formed in the lower slide die 5. The shunt 3.9 is fitted into the injection sleeve 9 (FIG. 9) on the fixed mold side to form a flow path for flowing the molten metal smoothly. An exhaust passage 17 is provided with an on / off valve 18 of a metal switch type, and an actuator 38 comprising a hydraulic cylinder for returning the on / off pulp 18 is provided.

The movable mold 3 is entirely covered with a part 14 b of the movable cover. A recess 42 is formed on the inner surface side of the base mold 4 of the movable mold 3, and a bolt 43 is inserted from the recess 42 to move the movable cover portion 14 b to the base mold 4. Secure from inside. The bolts 43 are fastened at four locations, for example, corresponding to the positions of four slide dies 5 (only one is shown in the figure). By fixing the movable cover part 14 b from the inside in this way, the bolts 43 do not protrude outward, so that the seal structure on the outer part of the cover is unnecessary or simple, and the movable cover The outer shape of the part 14b is simplified.

In place of the method of screwing the bolts 43 from the inside, a screw bolt is provided on the inner surface of a part of the cover, and a through hole corresponding to this is formed in the base mold 4, and the bolt is fixed to the bolt. It may be fixed by passing it through and fastening with a nut.

Also, instead of the fixing method using the bolts 43 from the inside, as shown by the imaginary line in the figure, the base mold 4 is It is also possible to fix with bolts 4 4.

A continuous seal groove 40 is formed along the entire circumference of the mating surface 32 of the movable cover part 14b with the fixed cover part 14a (Fig. 9), and the sealing material 15 is fitted. .

A recess 41 is also formed in a part 14 b of the movable side facing the flange 6 a of the cylinder (actuator) 6 for driving the slide die 5, and a seal material 15 is formed in the recess. Be attached.

FIG. 9 shows a fixed type corresponding to the movable type shown in FIG. 8, (A) is a front view, and (B) is a central sectional view.

A cylinder bore forming portion 7b is provided at the center of the fixed mold 2, and a through hole 45 for mounting the injection sleeve 9 is formed below the cylinder bore forming portion 7b. The fixed mold 2 is entirely covered with a fixed cover part 14a. The fixed side cover part 14a is fixed to the fixed mold 2 by bolts (not shown) from the inside similarly to the movable side cover part 14b described above.

The mating surface 3 2 of the fixed side cover 1 4 a facing the mating surface 3 2 (Fig. 8) formed on the movable side cover 1 4 b is a flat surface, and the movable side cover 1 4 Receive the sealing material 15 (Fig. 8) of b. By pressing the mating surfaces 3 2 of the movable side part 1 4 b and the fixed side part 1 4 a together, the movable side part 1 4 b and the fixed side via the sealing material 15 The cover portions 14a are hermetically sealed to form a part of a cover integrally formed with the two.

FIGS. 10A and 10B show a movable mold according to a seventh embodiment of the present invention, wherein FIG. 10A is a central sectional view and FIG. 10B is a front view.

The movable mold 46 of this embodiment includes a base mold 47 and one slide mold 48, and for example, a cavity 49 for forming a cylinder of a water-cooled engine is formed. A part 50 b of the movable side cover is locally attached so as to cover the mating surface (sliding surface) 30 of the base die 47 and the slide die 48. Solid A sealing groove (not shown) is formed on the mating surface 32 with the fixed side cover part 50a (FIG. 11) as in the example of FIG. 8, and the sealing material 15 is mounted. The sealing material 15 is provided continuously around the cavity 49 and on the mating surface 31 of the fixed mold 52 (FIG. 11) and the movable mold 46.

A recess (not shown) is also formed in the movable-side cover portion 5 Ob facing the flange 6 a of the cylinder (actuator) 6 for driving the slide die 4 8, and a sealing material 15 is formed therein. Is attached. Similarly, for the mating surface 51 between the movable cover part 50 b and the base mold 47, a recess (not shown) is formed in the movable cover part 5 O b and the inside thereof is formed. Seal material 1 5 is attached ο

FIG. 11 shows a fixed mold 52 corresponding to the movable mold 46 of FIG. 10, wherein (A) is a front view and (B) is a central sectional view.

At the lower part of the fixed mold 52, a through hole 45 for mounting the injection sleeve 9 is formed. The upper part of the fixed mold 2 is locally covered with a fixed cover part 50a corresponding to the movable cover 5Ob (FIG. 10). Similar to the movable cover part 50b, the fixed cover part 50a is provided with a recess (not shown) on the mating surface 51, and the seal material 15 attached to this recess is provided through the seal material 15 Fixed to the fixed mold 52.

The mating surface 32 of the fixed side cover 50a facing the mating surface 3 2 (FIG. 10) formed on the movable side cover 5Ob is a flat surface, and the movable side cover portion is formed by this plane. Receive 50 b of sealing material 15 (Fig. 10). The sealing material 15 is pressed by pressing the mating surface 3 2 of the movable cover part 50 b and the fixed cover part 50 a together, and the mating surface 31 of the movable mold 46 and the fixed mold 52. The movable-side cover portion 50b and the fixed-side cover portion 50a are hermetically sealed through the airtight portion, and a cover portion is formed integrally with the movable-side cover portion 50b, and the cavity 49 is sealed.

FIG. 12 is a sectional view of the cylinder bore honing step S5 in FIG. It is a process explanatory view. Honing is performed in three stages: (1) rough honing, (2) medium finishing honing, and (3) finishing honing. In rough honing (1), the bore diameter and roundness are formed by rough machining. In this rough honing, as shown in (A), the surface of the bore surface is roughened by grinding the surface of the A1 base material and the Si particles dispersed in the base material with a grindstone.

② In semi-finishing honing, the bore surface is mirror-finished as shown in (B).

In the finishing honing of (3), the A1 base material is ground by a predetermined amount, and the surface of the Si particles is raised as shown in (C). Instead of the finishing honing in (3), an alkali etching treatment that is immersed in an aqueous solution of caustic soda may be applied.

FIG. 13 is a top view of a cylinder block for a water-cooled engine. This example shows a three-cylinder open-deck cylinder block 25. A bore 27 is formed on the inner surface of each cylinder 26, and a space for each jacket 28 is formed on the outer periphery. A recess for fitting A1 alloy square bar-shaped reinforcement 29 into this water jacket 28 on the mating surface with the cylinder head is formed. After fabrication, a reinforcement piece 2 is inserted into this recess. Insert 9 and weld. In the die casting of the present invention, since the amount of gas contained in the product is extremely small by molding while reducing the pressure at a high vacuum as described above, the reinforcing piece 29 is welded to the product. Post-weld heat treatment (T5, T6 or T7) is performed, followed by machining and honing as before. The shape, number, and arrangement position of the reinforcing pieces 29 are not limited to the example shown in the drawing, and an appropriate number can be welded to an appropriate position. By welding such reinforcing pieces 29, the rigidity of each of the open-deck cylinders that cantilevered at the bottom is W

2 4 can be increased. Industrial applicability

As described above, in the present invention, since the mating surface of the mold is covered with a part of the cover, the mold cavity can be depressurized without applying a sealing material to the mating surface of the mold itself. Even if the mold has a complicated shape, the mating surface of a slide mold, etc., and the sealability of the sliding surface is likely to be uncertain, the mold itself is not sealed. By reducing the pressure by sealing with a part of the cover covering the mold, the degree of vacuum in the mold cavity can be sufficiently increased, and the gas can be reliably removed to eliminate cavities and welding and heat treatment can be performed. Can be obtained.

In this case, if a seal material is provided on the mating surface between the movable side and the fixed side part of the cover, the seal material is provided at a position separated from the high-temperature mold by a space. The influence is reduced, deterioration of the sealing material is prevented, and high sealing performance is maintained. Further, since the step of reducing the pressure of the cavity and the step of reducing the pressure between the cover part and the mold are performed, the pressure between the cover and the mold is reduced to reduce the pressure of the mold. In addition to directly reducing the pressure in the cavity, the cavity in the mold can be depressurized through the gap between the peripheral edges of the mold mating surface.The vapor in the mold release agent is also removed by suction. It can be discharged reliably. This makes it possible to improve the flow of the molten metal into the cavity and to obtain a high-quality die-cast product having no voids, even if it is a thin-walled cavity.

Further, by simultaneously performing the step of forming the cavity and the step of covering the entire or a part of the periphery of the mating surface of the molds with a part of the cover via a space, the molds are combined to form the cavity. At the same time, the mold is covered with the cover Therefore, the number of processes for covering the mold with the cover portion does not increase the cycle time of fabrication.

In addition, by performing a step of covering the whole or a part of the periphery of the mating surfaces of the dies through a space after the step of forming the cavities, the step of covering with a part of the cover after confirming the mold clamping is performed. Because of this, the reliability of space formation and sealing is improved.

Also, by performing the step of depressurizing the inside of the cavity and the step of depressurizing the space between the cover and the mold almost simultaneously, the space between a part of the cover and the mold is almost simultaneously depressurized in the cavity. Since the pressure is reduced, the number of processes for reducing the pressure between the cover part and the mold is not increased, so that the number of manufacturing cycles is not increased.

In addition, the process of depressurizing the inside of the cavity and the process of depressurizing the space between the part of the cover and the mold are carried out at different times, taking into account the interlocking shape of the slide mold and the exhaust passage resistance. By delaying the space exhaust time and the cavity exhaust time, the entire mold can be efficiently evacuated in order and the gas in the cavity can be exhausted reliably.

In addition, since 18 to 22 wt% of Si is contained in the aluminum alloy, sufficient Si particles can be obtained and abrasion resistance can be obtained even when the aluminum alloy is manufactured by the high-pressure die casting method with a high cooling rate. Sex is enhanced. If it is less than 18%, when produced by the high-pressure die-casting method, the Si particles do not become large and sufficient abrasion resistance cannot be obtained. On the other hand, if the content is 22% or more, it becomes brittle and deteriorates wear resistance. Furthermore, such moderate Si crystallizes on the surface during the manufacturing process and prevents seizure with the mold.

Further, since Fe is contained in the aluminum alloy in an amount of 0.4 to 1.5%, seizure with a mold is prevented when the aluminum alloy is manufactured by a high-pressure die casting method. In this case, the seizure prevention effect is combined with the seizure prevention effect of Si. Is further enhanced. ? If 6 is less than 0.4%, seizure cannot be sufficiently prevented. On the other hand, when the content is 1.5% or more, the intermetallic compound generated between Fe and A1 grows largely in the metal structure to form coarse acicular crystals, which become brittle and deteriorate extensibility.

Also, by rapidly cooling the die-cast structure taken out of the mold, compounds such as Cu and Mg are uniformly dispersed, and a uniform and stable strength can be obtained in place. Here, rapid cooling is represented by water-quenching quenching treatment, but is not limited to water cooling, but includes all cooling methods that actively cool mirror products other than natural cooling.

In addition, by producing an aluminum alloy product by the method of the present invention, it is possible to obtain a high-quality product capable of suppressing the generation of cavities and capable of welding and heat-treating.

In addition, when aluminum alloy products are used as engine cylinder blocks or pistons, high-quality cylinder openings or bistons that can be welded and heat-treated without cavities can be manufactured by a low-cost, high-pressure die-casting method. The cylinder block is a cylinder portion of the engine including the cylinder bore, and includes a case where a part of the crankcase / cylinder head is integrally formed. In addition, the piston is a piston that slides in the cylinder bore.Also, the aluminum alloy product is a cylinder block made of an aluminum alloy if it is a cylinder block of an engine and silicon crystals project from the surface of the cylinder bore. The raised Si crystal particles come into contact with the biston to form a sliding surface on the surface of the aluminum base material of the aluminum base material. The lubricating oil spreads all over, and a stable cylinder block with excellent wear resistance can be obtained. Furthermore, in the vacuum die casting apparatus for an aluminum alloy according to the present invention, since the mating surface of the mold is covered with a part of the cover, the cover is provided by a vacuum pump without applying a sealing material to the mating surface of the mold itself. A part of the mold can be sucked and evacuated to reduce the cavity inside the mold, and the mold with complicated shapes, mating surfaces of slide molds, etc. Even in the mold configuration, the degree of vacuum in the mold cavity can be sufficiently increased by sealing the part of the cover that covers the mold itself without applying a seal, and reducing the pressure. It is possible to obtain a high quality die cast product by reliably removing the burrs and eliminating welding and heat treatment.

In addition, if the cover part covers the entire periphery of the mating surfaces of the dies through a space and is fixed separately to the first and second dies, the cover part is separate, so existing The present invention can be carried out using the above-mentioned mold.

In addition, if the cover part is configured to cover the entire periphery of the mating surface of the dies through a space and to be integrally formed with the first and second dies, the cover part and the dies are integrated. This eliminates the need for parts for mounting the cover, reducing the number of parts and simplifying the configuration.

In addition, since the cover has a mounting part for mounting at least a part of the mold that drives the mold, the mold can be driven by attaching the part to the power bar. The structure of the mold is simplified, and the layout flexibility is increased.

In addition, if a fixing portion for fixing a part of the cover to the mold is formed on the inner surface of the cover, the part of the cover is fixed to the mold on the inner surface side of the cover. And the sealing structure is simplified because the mounting bolts do not protrude outward. '

Further, if the other end of the vacuum pipe connected to the common vacuum pump is connected to the space, and the cavity is connected to the vacuum pump through the space, The structure can be simplified by using a common vacuum pump and vacuum pipe, and the inside of the cavity can be efficiently evacuated through space.

If the cavity is connected to a common vacuum pump without passing through a space, the structure can be simplified using a common vacuum pump, and the space and the cavity can be evacuated with separate piping. This makes it possible to evacuate the cavity efficiently and reliably.

In addition, if the cavity and the space are connected to a vacuum pump of another system via a vacuum pipe of another path, the space and the cavity are evacuated by another vacuum pipe and another vacuum pump, so that the space is exhausted. A separate vacuum system is provided in consideration of the configuration of the unit and exhaust resistance, etc., so that the cavity can be evacuated efficiently and reliably.

Claims

The scope of the claims

1. A first mold and a second mold that can move relative to each other in one direction, and a slide mold that is sandwiched between the first mold and the second mold and that can move relatively in a direction different from the one direction. Forming a cavity by combining a plurality of molds with each other; depressurizing the inside of the cavity; and supplying a molten metal of the aluminum alloy into the cavity. The step of forming the cavity is accompanied by a step of covering the whole or a part of the periphery of the mating surface of the molds with a cover portion via a space, and subsequently, the step of forming the plunger tip The step of depressurizing the inside of the cavity by starting vacuum evacuation along with the forward movement at a low speed, and the step of depressurizing the space between the cover part and the mold are performed. Gradually increase the molten metal The vacuum die casting of aluminum alloy is characterized in that the plunger tip is moved at a high speed when the steel reaches the vicinity of the cavity inlet to rapidly supply the molten metal into the cavity and to adjust the flow rate of cooling water to the mold during this time. Method.

2. The aluminum according to claim 1, wherein the step of forming the cavity and the step of covering the whole or a part of the periphery of the mating surfaces of the molds with a cover portion via a space are simultaneously performed. Vacuum die casting method for alloys.

3. The step of covering the whole or a part of the periphery of the mating surface of the molds via a space after the step of forming the cavity, wherein the step of covering the entire or a part of the periphery of the mating surface between the molds is performed. Vacuum die casting method.

4. The step of depressurizing the inside of the cavity and the step of depressurizing the space between the cover part and the mold are performed almost simultaneously.

4. The method for vacuum-die-casting an aluminum alloy according to 2 or 3.

5. The aluminum alloy according to claim 2, wherein the step of depressurizing the inside of the cavity and the step of depressurizing the space between the cover and the mold are performed with a time lag. Vacuum die force manufacturing method.

6. The vacuum die-casting of the aluminum alloy according to claim 5, wherein, before the step of depressurizing the inside of the cavity, a step of depressurizing a space between the cover part and the mold is performed. Construction method.

7. The vacuum die-casting method for aluminum alloy according to claim 1, wherein the aluminum alloy contains Fe and contains 18 to 22 wt% of Si.

8. The method according to claim 7, wherein the aluminum alloy contains Fe in a range of 0.4 to 0.5 wt%.

9. The method for vacuum-die-casting an aluminum alloy according to claim 7 or 8, further comprising a step of rapidly cooling the structure taken out of the mold. '

10. An aluminum alloy manufactured using the vacuum die casting method for an aluminum alloy according to any one of claims 7 to 9.

ΠΡο

11. The aluminum alloy product according to claim 10, wherein the aluminum alloy product is a cylinder block or a piston of an engine.

12. The aluminum alloy product according to claim 10, wherein the aluminum alloy product is an engine cylinder block, and a silicon crystal protrudes from a surface of the cylinder bore.

13. A first and a second mold that can move relative to each other in one direction, and a stamp that is interposed between the first and second molds and that can move relatively in a direction different from the one direction. A vacuum die-casting and manufacturing apparatus of an aluminum alloy for forming a cavity by combining a plurality of molds composed of ride dies, depressurizing the inside of the cavity with a vacuum pump, and supplying a molten aluminum alloy into the cavity. In this case, a part of the cover is provided integrally with that of the first and second molds, and when the cavity is formed, the parts of the cover are in contact with each other via a sealing material, whereby The whole or a part of the periphery of the mating surface is configured to be covered with a part of a cover via a space, and a vacuum pipe for connecting the cavity and the space to a vacuum pump is provided, and the plunger tip is moved at a low speed. Along with the forward movement, evacuation is started, the pressure in the cavity and the space is reduced through the vacuum pipe, and when the molten metal reaches the vicinity of the cavity entrance, the pump is pumped. Njachidzupu was fast moving supplies rapidly molten metal into Kiyabiti, the vacuum die casting 鎵造 device § Ruminiumu alloy and performing cooling water flow rate adjustment to the Makin type.

14. The part of the cover covers the entire periphery of the mating surface of the molds via a space and is separately fixed to the first and second molds. 2. A vacuum die casting apparatus for an aluminum alloy according to claim 1.

15. The claim 13 in which the cover part covers the entire periphery of the mating surface of the dies through a space and is integrally formed with the first and second dies. A vacuum die-casting apparatus for the aluminum alloy as described above.

16. The aluminum alloy according to any one of claims 13 to 15, wherein the cover part has a mounting part for mounting an actuator for driving at least a part of a mold. Vacuum die casting machine.

17. The aluminum die vacuum die forming apparatus according to claim 14, wherein a fixing portion for fixing the part of the cover to the mold is formed on an inner surface of the part of the cover.

1 8. Connect the other end of the vacuum pipe connected to the common vacuum pump to the space. The vacuum die casting apparatus for an aluminum alloy according to any one of claims 13 to 17, wherein the cavity is connected to the vacuum pump via the space.

19. The vacuum die-casting apparatus for aluminum alloy according to claim 13, wherein the cavity is connected to a common vacuum pump without passing through the space.

20. The aluminum alloy vacuum die casting according to any one of claims 13 to 17, wherein the cavity and the space are connected to a vacuum pump of another system via a vacuum pipe of another path. apparatus.