JP2007275957A - Die-casting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die-casting apparatus, wherein the whole apparatus is constituted as compact and the setting space and the manufacturing cost can be reduced. <P>SOLUTION: This die-casting apparatus comprises: a main vessel 2 for melting a metallic material to be injected, in the inner part thereof; a heater 5 for heating the main body 2; an injecting nozzle 4 fitted to the main vessel 2; a pressurized gas supplying hole 9 formed in the main vessel 2 and supplying the pressurized gas into the main vessel 2; a metal supplying hole 6 penetrated in the main vessel 2; and and a feeding roller 7 for feeding into the main vessel 2 by inserting a wiry metallic material MW into the metal supplying hole 6, wherein the molten metal MM is injected through the injecting nozzle 4 with the pressurized gas from the pressurized gas supplying hole 9. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a die casting apparatus. More specifically, the present invention relates to a die casting apparatus used for die casting in which a metal material such as zinc or aluminum is melted and injected into a mold cavity to produce a casting.

  The die casting machine includes a hot chamber mold that melts a metal material in a melting pot (melting pan) and injects it into a mold cavity, and transfers the metal material from a separate incubator and injects it. A cold chamber type is known. Conventional hot chamber type die casting machines are generally disclosed in Patent Document 1 and Patent Document 2.

  That is, as shown in FIG. 2, the hot chamber type die casting machine 51 includes a heating furnace 53 for heating by a burner 52 and a melting pan 54 installed in the heating furnace 53. The metal material MM such as zinc melted in the melt pan 54 is guided into the cylinder 56 of the gooseneck main body 55. The molten metal MM pushed out by the plunger 58 connected to the piston rod 57 </ b> A of the pneumatic or hydraulic drive cylinder 57 is injected into the mold cavity 60 through the nozzle 59. The mold cavity 60 is formed between the fixed mold 61 and the movable mold 62.

  As described above, the conventional hot chamber type die casting machine 51 needs to install a large heating furnace 53 and requires a large-capacity melting pan 54, so that it becomes expensive and requires a large installation space. It takes a long time to melt the metal material by the burner 52, and the melting pan 54 is generally open, so that heat energy is wasted.

  Further, when the amount of molten metal (for example, zinc) decreases with use, it is necessary to newly introduce a metal lump MS as a material into the melting pan 54. The introduction of the metal mass MS relies exclusively on human hands. If this metal lump MS is introduced, the temperature of the molten metal MM in the melting pan 54 will be drastically lowered, and the die casting operation must be interrupted.

Furthermore, since the gooseneck main body 55 and the plunger 58 having a pump function are always immersed in the molten metal, they are easily damaged and have a short life.
Japanese Patent Laid-Open No. 2004-261841 Japanese Utility Model Publication No. 47-16574

  The present invention has been made to solve such a problem, and since the entire structure is very compact, it is possible to reduce the installation space and manufacturing cost, and it is also possible to shorten the tact time of die casting. An object of the present invention is to provide a die casting apparatus.

The die casting apparatus of the present invention is a die casting apparatus for injecting molten metal into a mold cavity,
A main body container that melts the metal material to be injected, a heating device that heats the main body container, an injection nozzle attached to the main body container, and a pressurized gas formed in the main body container. A pressurized gas supply port for supplying,
It is comprised so that molten metal can be injected through the said injection nozzle with the pressurized gas supplied in a main body container.

  In this die casting apparatus, it can be said that the main body container has a function of a function of a conventional gooseneck main body and a function of a melting pan. And the said pressurized gas has an effect | action of the conventional mechanical plunger. Thus, it does not require a large heating furnace and melting pan as in the prior art, and is freed from the problems of dipping the gooseneck into the melting pan. Therefore, the entire apparatus can be configured compactly.

The die casting apparatus can be provided with a metal material supply device for supplying the metal material to be injected into the main body container,
The metal material supply device can include a metal supply hole penetrating through the main body container, and a metal feeder for inserting a wire-like metal material into the metal supply hole and feeding the metal material into the main body container.

  If comprised in this way, it is not necessary to open | release a main body container and throw in a metal lump in it, A wire-shaped metal material can be continuously supplied in a main body container through the said metal supply hole. Therefore, the labor for supplying the metal material is greatly reduced, and the decrease in the container temperature is suppressed. As a result, the operating cost of die casting can be reduced and the tact time can be shortened.

  It is preferable that a level sensor for detecting the liquid level of the molten metal is provided in the main body container, and the metal feeding device is controlled so as to feed the metal material according to the detection result of the level sensor. . This is because it is possible to automatically generate a stable molten metal, and to shorten the cycle time of die casting.

A pressurized gas supply device for supplying pressurized gas into the main body container, connected to the pressurized gas supply port,
In this pressurized gas supply device,
A pressure cylinder for supplying pressurized gas to the pressurized gas supply port;
A lock device capable of switching between a locked state in which the piston of the pressure cylinder cannot move in the direction in which the gas is compressed and an action state in which the piston can move can be provided.

  If this locking device is provided, the piston of the pressure cylinder is locked and a driving force is applied, and when necessary, the lock is unlocked and activated to obtain a rapid operation of the pressure cylinder. The molten metal can be injected effectively.

A drive cylinder for driving the pressure cylinder is further disposed in the pressurized gas supply device,
The pressure receiving area of the piston of this driving cylinder is larger than the pressure receiving area of the piston of the pressure cylinder,
The piston rod of the drive cylinder and the piston rod of the pressure cylinder can be connected coaxially.

  If comprised in this way, the piston of a pressurization cylinder can apply a pressure higher than the pressure of the drive gas (working gas) supplied to a drive cylinder in a main body container. The above-mentioned “connecting the piston rods coaxially” means not only actually connecting the two piston rods but also sharing one piston rod for the drive cylinder and the pressure cylinder. It is meant to include.

An exhaust valve is disposed between a pressurized cylinder and a pressurized gas supply port in the pressurized gas supply device,
When the exhaust valve is closed, the inside of the main body container communicates with the inside of the pressurizing cylinder, and when the exhaust valve is opened, the inside of the main body container and the inside of the pressurizing cylinder can be opened to the atmosphere.

  Since the entire die casting apparatus of the present invention is configured to be very compact, the installation space and manufacturing cost can be reduced. In addition, the die casting tact time can be shortened.

  Embodiments of a die casting apparatus according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a partial sectional view schematically showing one embodiment of a die casting apparatus of the present invention.

  The illustrated die casting apparatus 1 includes a main body container 2 in which a metal material is melted. An injection hole 3 serving as a passage for the molten metal MM is formed at the bottom of the main body container 2, and an injection nozzle 4 is attached so as to communicate with the injection hole 3. The illustrated main body container 2 is configured as one closed container, but may be configured from an opened container main body and a detachable lid that closes the open portion. The main body container 2 is formed of a metal having corrosion resistance and sufficient pressure strength.

  A heater 5 for heating is mounted so as to cover the outer peripheral surface of the main body container 2 and the outer peripheral surface of the injection nozzle 4. The tip of the injection nozzle 4 where the injection port 4A is formed naturally protrudes from the heater 5 and is exposed to the outside. The heating principle of the heater 5 is not limited, but a heater that uses Joule heat is easily available and has a simple structure. The heater 5 dissolves a metal material such as zinc in the main body container 2.

  A metal supply hole 6 for supplying a metal material into the interior of the ceiling of the main body container 2 is formed. In the present embodiment, a wire-shaped metal (for example, zinc) MW having a uniform diameter is used as the metal material. This metal wire MW is wound around a rotatable storage drum D. The metal wire MW is inserted into the metal supply hole 6 by the feeder 7 and pushed into the main body container 2. The accommodation drum D that accommodates the metal wire MW, the feeding device 7 and the metal supply hole 6 constitute a metal material supply device. In the present embodiment, a plurality of sets of pulley-like rollers (having grooves that engage the wire on the periphery) 7 are used as the feeding device 7 to feed the wire by friction. In this embodiment, the outer diameter of the wire-like metal MW is planned to be about 0 to 0.02 mm larger than the inner diameter of the metal supply hole 6. Since the main body container wall is heated to a high temperature by the heater 5, the surface of the wire-like metal MW is softened when inserted through the metal supply hole 6. Therefore, the wire-like metal MW is fed into the main body container 2 without being caught, although it is in a dense state without generating a gap with the metal supply hole 6. The wire-like metal MW fed into the main body container 2 is continuously melted by the heating of the heater 5. Further, since the metal wire MW is densely inserted as described above and the metal supply hole 6 is formed long as shown in the drawing, even if the internal pressure of the main body container 2 temporarily rises, the metal supply hole 6 is provided. The compressed air does not escape to the outside from between the inner periphery of the hole 6 and the outer periphery of the metal wire MW.

  A level sensor (liquid level sensor) 8 is inserted from the ceiling of the main body container 2 downward to a predetermined planned depth inside the container. According to the level sensor 8, the liquid level is detected by electrical conduction when the tip of the level sensor 8 comes into contact with the molten metal MM. The metal material is supplied according to the detection result of the level sensor 8. For example, the metal supply operation of the feeding device 7 can be activated when the liquid level is not detected, and the operation can be controlled to stop when the liquid level is detected. Alternatively, for example, when a plurality of level sensors 8 having different setting depths are used, the feeding device 7 is activated when the lower sensor no longer detects the liquid level, and the upper sensor detects the liquid level. You may control to stop this operation | movement.

  With this configuration, the amount of the molten metal MM inside the main body container 2 is stabilized even during use of the die casting apparatus 1. As a result, the die casting operation can be interrupted due to the supply of the metal material, and rapid and significant fluctuations in the temperature of the molten metal MM accompanying the addition of the metal material can be suppressed.

  The main body container 2 is formed with a pressurized gas supply port 9 to which a pressurized gas for increasing the internal pressure is supplied. In the present embodiment, compressed air is used as the pressurized gas, but there is no particular limitation. A pressurized gas supply device 10 is connected to the pressurized gas supply port 9.

  The pressurized gas supply device 10 has a first pneumatic cylinder 11 and a second pneumatic cylinder 12 as shown, and the first pneumatic cylinder 11 is connected to the pressurized gas supply port 9 via an exhaust valve 13. It is communicated to. In the present embodiment, a three-way electromagnetic switching valve is employed as the exhaust valve 13, and the main body container 2 and the first pneumatic cylinder 11 are always communicated with each other so that the exhaust port 13A can be opened and closed.

  Both cylinders 11 and 12 have their own pistons 14 and 15, but one piston rod 16 is shared. Of course, different piston rods may be used, and both piston rods may be connected to each other in coaxial series. The first pneumatic cylinder 11 is configured as a so-called single rod single-acting cylinder. Of course, a double rod type may be used. The second pneumatic cylinder 12 is configured as a so-called double acting cylinder. By the operation of the second pneumatic cylinder 12, the piston 14 of the first pneumatic cylinder 11 is driven via the common piston rod 16, so that air can be compressed and sent to the main body container 2. Therefore, the first pneumatic cylinder 11 is called a pressurizing cylinder 11 and the second pneumatic cylinder 12 is called a drive cylinder 12.

  An air supply source such as a compressor (not shown) is connected to each of the first port 17 for supplying air and the second port 18 for exhausting of the double acting drive cylinder 12 through an electromagnetic switching valve 19. A port 20 on the head side of the pressure cylinder 11 (left side of the piston 14 in the figure) communicates with the main body container 2 through the exhaust valve 13. The pressure receiving area of the piston 15 of the drive cylinder 12 is formed to be about ten times the pressure receiving area of the piston 14 of the pressure cylinder 11. Then, when working air of a predetermined pressure is supplied from the first port 17 to the drive cylinder 12, the piston rod 16 moves to the left (indicated by a two-dot chain line in the figure) and is moved approximately toward the head side of the pressure cylinder 11. Ten times the pressure is generated. Of course, it is not limited to about ten times. However, in order to generate high-pressure compressed air in the movable cylinder 11 by the low-pressure air supplied to the drive cylinder 12, it is necessary to considerably increase it.

  The piston rod 16 extends outward through not only the head (left end) but also the bottom (right end) of the drive cylinder 12 as shown. An engaged portion 22 that can be engaged with the lock device 21 is formed in the vicinity of the end portion of the extending portion 16A of the piston rod that extends rightward outward through the bottom. FIG. 1 illustrates a hook member 24 as a main component of the locking device 21. A hook-shaped engagement portion 23 is formed in the vicinity of the distal end of the hook member 24, and the base end portion is pivotally supported to be swingable. The hook member 24 is biased by the spring member 25 toward a locked position where the hook member 24 is engaged with the engaged portion 22 of the extension portion 16A, that is, a position where the piston rod 16 cannot be moved. A drive device 26 is provided for swinging the hook member 24 in the direction in which the engagement with the engaged portion 22 is released, that is, toward the operating position where the piston rod 16 can move. . The drive device 26 may be a fluid pressure cylinder as shown in the figure, or may be another suitable drive device such as a solenoid.

  An inclined surface 22A is formed at the end of the extended portion 16A of the piston rod (the rear end of the engaged portion 22), and the tip of the hook member 24 is complementarily inclined so as to face the inclined surface 22A. An inclined surface 24A is formed. Accordingly, when the piston rod 16 returns from the left position indicated by the two-dot chain line to the right initial position indicated by the solid line, even if the hook member 24 is in the locked position, the inclined surfaces 22A of the both 16 and 24, 24A mutually slides, and finally the to-be-engaged part 22 and the engaging part 23 engage.

  Further, as another locking device, a grip member using a solenoid, a toggle mechanism, or the like that can grip or release the extension 16A of the piston rod may be employed.

  As shown in the figure, the locking device 21 is for stopping the piston rod 16 from moving to the left and stopping the driving (pressurizing operation) of the pressurizing cylinder 11. Therefore, even if the working air is supplied from the first port 17 to the drive cylinder 12 with the piston rod 16 locked, the piston rod 16 does not move to the left. When the engagement of the lock device 21 is released by the drive device 26 when the internal pressure on the bottom side of the drive cylinder 12 reaches a predetermined pressure, the piston rod 16 moves to the left at once (two points in the figure). The pressure cylinder 11 is rapidly driven. As a result, high pressure air is instantaneously supplied from the pressurizing cylinder 11 into the main body container 2 as if it exploded. In this embodiment, the stroke ends of the pistons 14 and 15 in both cylinders 11 and 12 are not restricted by mechanical stoppers. When driven by the drive cylinder 12, the piston is driven by a balance between the force of the working air supplied to the bottom side of the drive cylinder 12 and the force of the compressed air on the head side of the pressure cylinder 11 (same as in the main body container). The left stroke of the rod 16 is stopped.

  Molten metal injection should be performed within a very short time. Even when a compressed gas is used instead of the mechanical pressurization of the conventional plunger, an instantaneous pressurizing force that is not inferior to the conventional technology can be obtained by using the pressurized gas supply device 10 having the above-described configuration. it can. In addition, maintenance becomes easy. The pressurized gas supply device 10 is a pressurizing device suitable for the die casting device 1 including the main body container 2 described above, but various other devices that require instantaneous pressurization, such as sheet metal processing and perforation. It has an independent value that it can be applied to a pressurizing means in a press machine for processing, a pressurizing means of an active damper for buffering, and the like.

  The pressurized gas supply device 10 has a convenient usage as described below. After the injection of the molten metal MM into the mold cavity 60 by the die casting apparatus 1 is finished, the tip of the injection nozzle 4 is separated from the gate 61A of the fixed die 61. At this time, the molten metal is exposed from the injection port 4A at the tip of the nozzle. is doing. Since the injection nozzle 4 is attached to the bottom of the main body container 2 and faces downward, the molten metal is exposed by the action of gravity. When the nozzle tip is brought into contact with the stationary gate 61A in an attempt to continue injection in this state, the molten metal MM at the nozzle tip may be cooled and solidified. If this happens, it cannot be ejected. However, if this pressurized gas supply device 10 is used, as will be described later, the exhaust valve 13 is opened after the injection is completed, and the internal pressures of the main body container 2 and the pressurizing cylinder 11 are returned to the atmospheric pressure. After the valve 13 is closed, the piston 14 of the pressurizing cylinder 11 is returned to the initial position (shown by a solid line in FIG. 1), so that the inside of the main body container 2 becomes negative pressure. As a result, the molten metal MM in the injection nozzle 4 is slightly sucked up to the inside, that is, the outer periphery of the molten metal MM is covered with the heater 5, so that even if the nozzle tip contacts the gate 61A at the next injection, the nozzle The molten metal MM inside does not solidify. That is, solidification of the molten metal at the nozzle tip is prevented by a normal continuous injection operation.

  Next, an example of the operation of the die casting apparatus 1 will be described with reference to FIG. First, the main body container 2 is heated by the heater 5. Then, the feed roller 7 is operated to supply the metal wire MW into the main body container 2. The metal wire MW is melted in the main body container 2 and the molten metal MM is accumulated. When the level sensor 8 detects the liquid level of the molten metal MM, the metal supply operation of the feed roller 7 is stopped. At this time, the pistons 14 and 15 of the pressurized gas supply device 10 are at positions indicated by solid lines in the figure, and the piston rod 16 is stopped at the solid line position by the lock device 21. Meanwhile, working air is supplied from the first port 17 to the bottom side of the drive cylinder 12 from an air supply source (not shown). The exhaust valve 13 closes its exhaust port 13A.

  Next, in order to start die casting, the fixed die 61 and the movable die 62 are integrally moved closer to the main body container 2, and the tip of the injection nozzle 4 comes into contact with the gate 61A. That is, the runner of the fixed mold 61 communicates with the injection port 4A at the tip of the nozzle. At the same time that this contact is detected by a sensor (not shown), the driving device 26 of the locking device 21 is activated to unlock the piston rod 16. Then, the pistons 14 and 15 instantaneously move to the left to drive the pressurizing cylinder 11, and high-pressure compressed air is supplied from the pressurizing cylinder 11 into the main body container 2 via the exhaust valve 13. Due to the force of the high-pressure air, only a part of the molten metal MM in the main body container 2 is injected into the mold cavity 60.

  As soon as the injection is finished, the injected metal is solidified in the mold cavity 60. Next, the left and right movable dies 62 move sideways slightly together to cut the metal in the runner (called gate cutting). At substantially the same time as the gate is turned off, the exhaust port 13A of the exhaust valve 13 opens momentarily, the compressed air in the main body container 2 and the compressed air in the pressurizing cylinder 11 are diffused into the atmosphere, and the internal pressure of the main body container 2 and the pressurizing cylinder 11 is large. Decrease to atmospheric pressure. Immediately, the exhaust port 13A of the exhaust valve 13 closes and the piston rod 16 returns to the right toward the initial position. By this operation, the internal pressure of the main body container 2 and the internal pressure on the head side of the pressurizing cylinder simultaneously become negative pressures. Then, the fixed mold 61 and the movable mold 62 are integrally separated from the injection nozzle 4. Then, due to the negative pressure in the main body container 2, the molten metal at the injection port 4A at the tip of the nozzle is sucked up. Next, both movable molds 62 open to the left and right, and the die-cast product is taken out. The above series of operations is performed quickly.

  The piston rod 16 that has returned to the initial position is locked by engaging the engaging portion 23 of the locking device 21 with the engaged portion 22. Here, one cycle of die casting ends. Working air is supplied to the bottom side of the drive cylinder 12 for the next die casting.

  By repeating the above operations, a large number of die-cast products having the same shape are automatically manufactured in a very short tact time.

  In the present embodiment, the injection nozzle 4 is attached to the bottom of the main body container 2 downward, but is not limited to this configuration. For example, at the bottom of the main body container 2, a pipe that is curved in a U shape, a V shape, or the like and is directed upward, laterally, or diagonally is attached, and the top of the pipe is directed upward, laterally, or diagonally. You may attach an injection nozzle to. By doing so, it is not necessary to consider the operation of sucking molten metal inward from the tip of the injection nozzle.

  In the present embodiment, the above-described excellent pressurized gas supply apparatus 10 is used to instantaneously increase the internal pressure of the main body container 2, but the present invention is not limited to this configuration. Instead of the pressurized gas supply device 10, a known cylinder filled with nitrogen gas or the like at a high pressure for increasing the internal pressure of the main body container 2 may be used.

  The application of the metal wire MW used as the die casting material and the feed roller 7 in this embodiment is not limited to the supply of the metal material to the main body container 2. For example, it will be apparent to those skilled in the art that the present invention is sufficiently applicable as a material supply means to a conventional die casting machine 51 as shown in FIG. Furthermore, the level sensor 8 can be easily applied in combination. By doing so, the conventional die-casting machine 51 can also be advantageous in that it is possible to omit operations such as manual metal lump insertion and monitoring of the amount of molten metal in the melting pan.

  A metal wire as a die casting material is manufactured by applying various known processing methods such as a continuous casting rolling method using a multi-stage rolling roller, an extrusion process using a die having a circular section, and a roller die drawing method. It is possible. Further, the feeding device for the metal wire MW is not limited to the feeding roller 7. For example, a reciprocating chuck member may be employed. That is, the chuck member grips the metal wire MW, feeds it toward the main body container 2 by a small size (for example, 5 to 20 mm), and pushes it in from the metal supply hole 6. Next, the metal wire MW is released from the grip and returned by the same dimension. This operation is repeated as necessary, and the metal wire MW is intermittently supplied into the main body container 2.

  Since the injection method is pressurized by a compressive fluid, it is desirable to reduce the pressure loss from the pressurizing cylinder 11 to the main body container 2 as much as possible. In order to reduce the resistance of the flow path of the compressed air, it is preferable to increase the cross-sectional area of the flow path from the pressure cylinder 11 to the main body container 2. Further, in order to reduce the volume from the pressurizing cylinder 11 to the main body container 2, it is preferable that the pressurization cylinder 11, the exhaust valve 13 and the main body container 2 are close to each other. The pressurizing cylinder 11, the exhaust valve 13, and the main body container 2 are preferably formed integrally in one block.

  On the other hand, it is also preferable to form the pressure cylinder 11 and the drive cylinder 12 integrally. This is because it is easy to share a piston rod, and it is easy to form both cylinders 11 and 12 coaxially.

  The present invention is useful for making the entire die casting apparatus very compact and reducing the installation space and manufacturing cost.

It is a partial sectional view showing roughly one embodiment of the die-casting device of the present invention. It is sectional drawing which shows an example of the conventional die-casting apparatus.

Explanation of symbols

1 ... Die casting equipment
2 ... Main body container
3 .... Injection hole
4 .... Injection nozzle
5. Heater
6 ... Metal supply hole
7. Feed roller
8. Level sensor
9 ... Pressurized gas supply port
10 .... Pressurized gas supply device
11 ... Pressure cylinder (first pneumatic cylinder)
12 .... Drive cylinder (second pneumatic cylinder)
13. Exhaust valve
14 ... Piston (for pressure cylinder)
15 ... Piston (of driving cylinder)
16. Piston rod
17 ··· First port (of drive cylinder)
18 ··· Second port (of drive cylinder)
19 .... Electromagnetic switching valve
20... Head side port (of pressure cylinder)
21... Locking device
22... Engaged portion
23... Engaging portion
24... Hook member
25... Spring member
26... Drive device
60 ··· Mold cavity
D ··· Drum
MM ... Molten metal
MW ... ・ Metal wire

Claims (6)

A die casting apparatus for injecting molten metal into a mold cavity,
A main body container that melts the metal material to be injected therein;
A heating device for heating the main body container;
An injection nozzle attached to the main body container;
A pressurized gas supply port for supplying pressurized gas into the main body container, formed in the main body container;
A die casting apparatus configured to be able to inject molten metal through the injection nozzle by a pressurized gas supplied into a main body container. A metal material supply device for supplying the metal material to be injected into the main body container is disposed,
The metal material supply device includes a metal supply hole penetrating the main body container, and a metal feeding device for inserting a wire-like metal material into the metal supply hole and feeding the metal material into the main body container. The die casting apparatus as described.   The main body container is provided with a level sensor for detecting the liquid level of the molten metal, and the metal feeding device is controlled to perform the feeding operation of the metal material according to the detection result of the level sensor. The die casting apparatus according to claim 2. A pressurized gas supply device for supplying pressurized gas into the main body container, connected to the pressurized gas supply port;
The pressurized gas supply device comprises:
A pressure cylinder for supplying pressurized gas to the pressurized gas supply port;
2. A lock device capable of switching a piston of the pressurizing cylinder between a locked state in which the piston cannot move in a direction in which gas is compressed and an operating state in which the piston can move. The die casting apparatus as described. The pressurized gas supply device further comprises a drive cylinder for driving the pressure cylinder;
The piston rod of the drive cylinder and the piston rod of the pressure cylinder are connected coaxially,
The die casting apparatus according to claim 4, wherein the piston of the drive cylinder is configured to have a larger pressure receiving area than the piston of the pressure cylinder. The pressurized gas supply device further comprises an exhaust valve disposed between the pressurized cylinder and the pressurized gas supply port;
The inside of the main body container and the inside of the pressurizing cylinder communicate with each other when the exhaust valve is closed, and the inside of the main body container and the inside of the pressurizing cylinder are opened to the atmosphere when the valve is opened. 4. The die casting apparatus according to 4.

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