JP3175142B2 - Die casting method and die apparatus for die casting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of die-casting a metal material and a die-casting die apparatus.

[0002]

2. Description of the Related Art In die casting, a product is formed by filling a molten metal material into a product-shaped cavity formed in a mold, and cooling and solidifying the material.

FIG. 5 shows a conventional die casting die apparatus. In the figure, 1 is a fixed type, 2 is a movable type,
The fixed mold 1 and the movable mold 2 open and close with each other. A cavity 3, a runner 4 as a runner, a gate 5 from the runner 4 to the cavity 3, an overflow section 6, and an overflow section from the closed mold 1 and the movable mold 2 6 is formed.

[0004] Then, at the time of die casting, after closing the mold,
A molten metal material is supplied to the runner 4 from a material supply device such as an injection cylinder of a die casting machine, flows into the cavity 3 from the runner 4 through the gate 5, and is filled. At this time, gas such as air in the cavity 3 and the like is discharged outside the mold through the vent path 7 and the overflow section 6. Then, as indicated by a chain line in FIG. 5B, the metal material flows into a part of the overflow section 6 from the cavity 3 through the vent path 7.
Then, after the metal material in the mold is cooled and solidified, the mold is opened, and the metal material in the cavity 3, that is, the product is taken out together with the metal material solidified in the runner 4 and the overflow section 6. The metal material solidified in the runner 4 and the overflow section 6 is cut off from the product by post-processing.

As described above, in the conventional die casting method, the metal material of the runner 4 and the overflow section 6 must be processed by post-processing, which is troublesome. Although the vent path 7 for venting the gas has a width that does not allow the metal material to enter therein, there is a mold device without an overflow portion, but the treatment of the metal material of the runner 4 is still necessary.

Since the metal material shrinks with cooling, even after the cavity 3 is filled with the metal material, the supply of the metal material to the cavity 3 is continued for a while due to, for example, pressurization by a material supply device. Minutes of metal material must be supplemented.

In the case where the overflow portion 6 is not provided, in the conventional mold apparatus, since the volume of the cavity 3 is constant, the pressure and the amount of the metal material filled in the cavity 3 are basically controlled by the die casting machine. Will be determined by Therefore, if there is an error in the control of the die casting machine,
As it is, an error occurs in the pressure and amount of the metal material filled in the cavity 3. In order to eliminate this error, it is conceivable to make the control of the injection cylinder and the like precise. However, the cause of the error is various, such as temperature and variations in the properties of the metal material itself. For example, although there is a long runner from the injection cylinder to the cavity 3, if there is an error generated in this runner, even if the injection cylinder is precisely controlled, the pressure of the metal material filled in the cavity 3 or the like can be reduced. There will be errors in the quantities. This error causes defects such as variation in product weight.

On the other hand, if there is an overflow portion 6, excess metal material is discharged into the overflow portion 6, so that the pressure and amount of the metal material filled in the cavity 3 are further stabilized. However, as mentioned above,
Post-processing of the metal material of the overflow section 6 is necessary.

[0009]

As described above, in the conventional die casting mold apparatus, the gate is always open, so that the metal material in the material passage portion such as a runner must be processed by post-processing. There was a problem to be had. In addition, since the volume of the cavity is constant, there is a problem that it is difficult to accurately control the pressure and amount of the metal material filled in the cavity, particularly when no overflow portion is provided. On the other hand, when the overflow portion is provided, there is a problem that the metal material of the overflow portion must be processed by post-processing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its first object to eliminate the need for post-processing of a metal material in a material passage or an overflow portion without causing insufficient filling. And It is a second object of the present invention to enable accurate control of the pressure and amount of the metal material filled in the cavity. A third object is to simplify the configuration for degassing.

[0011]

According to a first aspect of the present invention, there is provided a die casting method, comprising: a plurality of molds which are opened and closed with each other to form a cavity therebetween when the mold is closed; And a volume adjusting means for adjusting the volume of the cavity, wherein a mold device is used in which the gate from the material passage to the cavity is closed as the volume adjusting means reduces the volume of the cavity. Then, first, a filling step of filling the molten metal material supplied from the material supply device to the material passage into the cavity having the increased volume is performed. After the filling step, a weighing step of reducing the volume of the cavity and returning the metal material in the cavity to the material supply device side until the gate closes is performed. After the measurement step, a compression step of reducing the volume of the cavity to a predetermined volume and compressing the metal material in the cavity is performed.

According to a second aspect of the present invention, in the die casting method according to the first aspect of the present invention, in order to also achieve the second object, a material supply device supplies a cavity to the cavity between the filling step and the measuring step. By continuing to supply the metal material and increasing the volume of the cavity appropriately according to this supply,
The pressure adjusting step for adjusting the pressure of the metal material in the cavity is added.

According to a third aspect of the present invention, there is provided a die-casting mold apparatus comprising a plurality of molds which open and close with each other and form a cavity therebetween when the mold is closed, in order to also achieve the third object. The mold has a closing member that abuts against another mold and closes, and a compression member that is slidably penetrated through the closing member to form a cavity, and a gate from the material passage to the cavity is provided with: A gas vent, which is provided at a position closed by the compression member as the compression member moves in the direction to reduce the volume of the cavity and allows gas to escape from the cavity to the outside, is formed by a gap between the closure member and the compression member. Things.

[0014]

In the die casting method according to the first aspect of the present invention, after filling the metal material into the cavity, the volume is reduced by the volume adjusting means to close the gate, and the metal material remaining in the cavity and the material passage in the material passage are closed. The metal material is cut in a mold apparatus. After that, the metal material is not supplied into the cavity from the material supply device, but the volume of the cavity is further reduced by the same volume adjusting means, and the metal material in the cavity is compressed, so that the metal material shrinks due to solidification. Is compensated.

Further, in the die casting method according to the second aspect of the present invention, in the pressure adjustment step following the filling step, the supply of the metal material from the material supply apparatus to the mold apparatus is continued. Is supplied, the volume of the cavity is increased by the volume adjusting means. Thereby, even if there is an error in the amount of the molding material supplied from the material supply device, the error is absorbed, and the pressure of the metal material in the cavity is adjusted to be constant. On the other hand, when the pressure adjustment step is completed, the amount of the metal material in the cavity is not constant, but in the subsequent measurement step, as the volume of the cavity becomes smaller, excess metal material in the cavity becomes material. Returning to the supply device side, when the gate is closed, a certain amount of metal material remains in the cavity. Thus, the pressure adjustment step and the metering step accurately control the pressure and amount of the metal material filled in the cavity.

According to a third aspect of the present invention, there is provided a die casting die apparatus for performing the die casting method of the first and second aspects of the invention, wherein the volume of the cavity is adjusted by a closing member and a compression member. It constitutes volume adjusting means. That is, the volume of the cavity is adjusted by moving the compression member forming the cavity with respect to the closing member in a state where the closing member is abutted against another mold and closed. Further, as the compression member moves in a direction to reduce the volume of the cavity, the gate is closed by the compression member. During the die casting, gas is released from the cavity to the outside by the gas vent formed by the gap between the closing member and the compression member slidably penetrating the closing member in the filling step.

[0017]

Hereinafter, an embodiment of the present invention will be described.
This will be described with reference to FIGS. In the present embodiment, a hot chamber type die casting machine as shown in FIG. 4 is used. In FIG. 4, reference numeral 11 denotes a material supply device,
In the material supply device 11, a pressurizing chamber 13 is provided in a heating and melting tank 12, and a nozzle 14 is provided at a tip of the pressurizing chamber 13. A plunger 16 of an injection cylinder 15 formed of a hydraulic cylinder is slidably fitted in the pressurizing chamber 13.

Reference numeral 21 denotes a mold clamping device.
Has a fixed-side platen 22 and a movable-side platen 23. The movable platen 23 is freely movable in the horizontal direction in the figure along a tie bar 24,
Is driven through the toggle mechanism 26 by the The drive of the hydraulic cylinder 25 is controlled by a drive control device 27 including a servo valve and the like, so that the mold clamping force can be adjusted. The fixed mold 32 of the mold apparatus 31 is attached to the fixed platen 22, and the movable mold 33 is attached to the movable platen 23. In addition, the mold clamping device
21 and the material supply device 11 are comprehensively controlled by a control device such as a computer.

Next, the structure of the mold apparatus 31 will be described with reference to FIGS.
It will be described in detail based on. In FIG. 1 and FIG. 2, a metal material which is a product such as a zinc alloy or an aluminum alloy is indicated by a thick line with hatching. The fixed mold 32 and the movable mold 33, which are a pair of molds, are opened and closed by the movement of the movable platen 23, and form a product-shaped cavity 34 therebetween when the mold is closed.
The product P to be molded has a disk shape, and its axial direction coincides with the opening and closing directions of the fixed mold 32 and the movable mold 33.

The fixed die 32 has a fixed mounting plate 36 mounted on the fixed platen 22 and a fixed receiving plate 37 fixed to a surface of the fixed mounting plate 36 on the movable die 33 side. The fixed-side mounting plate 36 and the fixed-side receiving plate 37 constitute a base body 38 as a compression member. A locate ring 39 and a sprue bush 40 are fixed to the fixed-side mounting plate 36. The sprue bush 40 is connected to the nozzle 14 of the material supply device 11, and has a sprue 41 having a material passage therein.
It penetrates through the fixed-side receiving plate 37 and protrudes toward the movable mold 33.

On the movable mold 33 side of the fixed-side receiving plate 37,
A moving plate 46 as a closing member is supported so as to be movable in a predetermined range in the mold opening / closing direction. For this support, a sleeve 50 fixed by bolts 49 together with a stopper 48 on the movable mold 33 side of the fixed-side receiving plate 37 slidably penetrates the movable plate 46. The stopper 48 limits the maximum gap between the movable plate 46 and the base body 38, that is, the maximum opening amount by hitting the movable plate 46 from the movable mold 33 side.
Further, the movable plate is moved by a spring 51 which is an urging means sandwiched between the fixed mounting plate 36 and the movable plate 46 in a compressed state.
46 is urged toward the movable mold 33 with respect to the base 38.
The tip of the sprue bush 40 is slidably fitted in a through hole 52 formed in the movable plate 46.

The base 38 has a fixed mounting plate.
The pin 56 is fixed by being sandwiched between the fixed side receiving plate 37 and the fixed side receiving plate 37.The pin 56 penetrates through the fixed side receiving plate 37 and protrudes toward the movable mold 33. , Moving plate 46
Is slidably fitted in a through hole 57 formed in the hole. The distal end of the pin 56 forms a protrusion 58 that can protrude toward the movable mold 33 from the movable plate 46.

The movable mold 33 is provided with a movable plate 46 of the fixed mold 32.
And has a movable side mold plate 61 which abuts and closes. For mutual guidance of the movable mold plate 61 and the movable plate 46,
A guide pin 62 is fixed to the movable plate 46, and a through hole in which the guide pin 62 is slidably fitted is formed in the movable mold plate 61.
63 are formed.

The movable mold plate 61 includes the fixed mold 32.
A concave portion 64 is formed in which the convex portion 58 is removably fitted. The fitting surface between the convex portion 58 and the concave portion 64 forms a column surface parallel to the mold opening and closing direction. Then, the cavity 34 having the final product shape is formed by the convex portions 58 and the concave portions 64. That is, the tip surface of the convex portion 58 forms one end surface of the product P, the bottom surface of the concave portion 64 forms the other end surface of the product P, and the inner peripheral surface of the concave portion 64 forms the outer peripheral surface of the product P. .
Then, by moving the movable plate 46 and the movable mold plate 61 of the closed fixed mold 32 with respect to the base body 38 of the fixed mold 32, the volume of the cavity 34 is continuously changed. A volume adjusting means for adjusting the volume of the cavity 34 is provided.

The movable plate 46 of the fixed mold 32 and the movable mold
A runner 66 and a gate 67, which are material passages for connecting the sprue 41 to the cavity 34, are formed between the movable mold plate 61 and the movable mold plate 61. An annular concave portion 68 surrounding the convex portion 58 is formed on the surface of the movable plate 46 on the movable mold 33 side. The recess 68 communicates with the runner 66 and forms a part of the runner 66 and a gate 67 from the runner 66 to the cavity 34. The gate 67 is closed when the projection 58 of the fixed mold 32 is fitted into the recess 64 of the movable mold 33. The force with which the spring 51 urges the moving plate 46 is set to a force that keeps the moving plate 46 and the movable mold 33 closed against the pressure of the metal material in the runner 66.

Incidentally, in the stationary mold 32, the base 38
The gap C between the outer peripheral surface of the pin 56 and the inner peripheral surface of the through hole 57 of the movable plate 46 is set to about 0.1 mm on the movable die 33 side facing the recess 68. The size of the gap C is set so that a molten metal material cannot enter, but a gas such as air can pass. Thus, the gas vent 71 that allows gas to escape from the inside of the cavity 34 to the outside is formed by the gap C.
Are formed.

Although not shown, the movable mold 33 includes:
A protruding mechanism is provided for protruding and releasing the molded product P and the solidified metal material in the runner 66 with the opening of the mold.

Next, the die casting method will be described. In the heating and melting tank 12 of the material supply device 11, the metal material is always in a molten state by heating.

The mold clamping device 21 first closes the fixed mold 32 and the movable mold 32 with a weak constant mold clamping force F1. At this time, FIG.
As shown in (a), the movable plate 46 of the fixed die 32 and the movable die 33 abut and close. On the other hand, the base body 38 of the fixed mold 32 and the moving plate 46 are opened with the initial opening amount A1, but the stopper 48 does not hit the moving plate 46. That is, mold clamping force
F1 and the force G of the spring 51 are balanced. In addition, the convex portion 58 of the fixed die 32 is not fitted to the concave portion 64 of the movable die 33,
The open gate 67 allows the runner 66 to communicate with the cavity 34 whose volume has been increased to some extent. In this state, the plunger 16 of the injection cylinder 15 is advanced in the material supply device 11 to move the nozzle from the pressurizing chamber 13 to the nozzle.
The molten metal material (molten metal) is injected into the sprue 41 of the mold apparatus 31 via the. This metal material is filled into the cavity 34 from the sprue 41 through the runner 66 and the gate 67 (filling step). At this time, gas is discharged from the inside of the cavity 34 to the outside through a gas vent 71 formed by a gap between the outer peripheral surface of the pin 56 of the base 38 of the fixed mold 32 and the inner peripheral surface of the through hole 57 of the movable plate 46. You. This gas is applied to the open substrate 38
It goes out of the mold device 31 through a gap between the moving plate 46 and the moving plate 46.

Subsequent to the filling step, the mold supply force is maintained at F1 and the material supply device 11 continues until the plunger 16 is detected to advance to a predetermined position, or
The injection process continues until the plunger 16 advances to the advance limit. That is, the supply of the metal material from the material supply device 11 to the mold device 31 is still continued.
As shown in FIG. 1B, the pressure of the metal material in the base 31 causes the base body 38 of the stationary mold 32 to resist the mold clamping force F1 given by the mold clamping device 21 whose hydraulic pressure is not closed. Moving plate 46
And the movable mold 33 is displaced in the opening direction. By increasing the volume of the cavity 34 by an appropriate amount, the generated internal pressure is released. The enlarged opening amount A2 between the base 38 and the moving plate 46 is determined by the balance between the pressure of the metal material in the mold apparatus 31 and the mold clamping force. More specifically, mold clamping force F1
The opening amount A2 is determined by the balance between the force G of the spring 51 and the force H that causes the metal material in the mold apparatus 31 to retreat the movable plate 46 and the movable mold 33. The opening amount A2 increases as more metal material is supplied into the mold apparatus 31. In other words, even if there is an error in the amount of the metal material supplied from the material supply device 11, the error is absorbed by the change in the opening amount, and the pressure of the metal material in the cavity 34 is adjusted to be constant ( Pressure regulation step). Thus, the cavity 34
The pressure of the metallic material inside can be controlled accurately.

When the opening amount increases from A1 to A2, the force G of the spring 51 becomes slightly weaker, and when the toggle mechanism 26 is pushed back together with the movable mold 33, the mold clamping force given by the hydraulic cylinder 25 also slightly changes. However, the changes in the force G of the spring 51 and the mold clamping force are negligibly small. That is, the pressure G of the metal material, which varies in accordance with the displacement G of the movable plate 46 and the movable mold 33 and the pressure of the metal material balanced with the mold clamping force, varies when the cavity having a certain volume is filled with different amounts of the metal material. Is much smaller than the pressure variation that occurs in

In the pressure adjusting step, the pressure of the metal material acting to open the base 38 of the fixed mold 32, the movable plate 46, and the movable mold 33 is parallel to the mold opening and closing direction for the fixed mold 32. Pressure on the substrate 38 in the direction. This is the pressure involved in pressure regulation. On the other hand, in the mold apparatus 31 of the embodiment, since the runner 66 is formed between the movable plate 46 of the fixed mold 32 and the movable mold 33, the base 38, the movable plate 46 and the movable mold 33 are opened. The pressure of the metallic material that acts
Approximately only the cavity 34 rests on the substrate 38 (more precisely, includes the sprue bush 40). Therefore, the pressure is adjusted based on the cavity 34. On the other hand, the pressure of the metal material in the runner 66 is
However, the spring 51 resists the pressure of the metal material in the runner 66, and the movable plate 46 and the movable mold 33 are opened.
And are kept closed. This is the same in the next measuring step.

After the end of the pressure adjusting step, the mold clamping device 21 increases the mold clamping force to F2. Thereby, the base 38 of the fixed mold 32 and the moving plate
46 closes. Accordingly, the excess metal material in the cavity 34 whose volume is reduced returns to the runner 66 from the gate 67 which is still open, and the metal material in the mold device 31 is removed from the pressurizing chamber 13 of the material supply device 11. Return inside. The plunger 16 retreats accordingly. Then, as shown in FIG. 2A, when the convex portion 58 of the fixed mold 32 starts to be fitted into the concave portion 64 of the movable mold 33, the gate 67 closes. Will remain (a weighing step).

After the measuring step, as shown in FIG.
The base 38 of the fixed mold 32 and the moving plate 46 close until they abut each other, and accordingly, the volume of the cavity 34 decreases to a predetermined volume. Thereby, the metal material in the cavity 34 is pressurized and compressed (compression step). The compression amount B is
Opening amount A3 between the base 38 and the moving plate 46 at the end of the measuring process
be equivalent to.

At the end of the pressure regulation step, the volume of the cavity 34, that is, the amount of the metal material in the cavity 34 is not constant. However, in the subsequent weighing process,
As described above, the metal material in the cavity 34 returns to the runner 66, and at the moment when the gate 67 is closed, a certain amount of the metal material remains in the cavity 34. In this way, the pressure and amount of the metal material filled in the cavity 34 are accurately controlled by the pressure adjustment step and the metering step.

Incidentally, in the mold apparatus 31, the runner
By forming 66 between the movable plate 46 and the movable mold 33 instead of the base 38 of the fixed mold 32, the runner
The volume of 66 does not change. Therefore, the metal material smoothly returns from the cavity 34 whose volume decreases to the runner 66, and the pressure of the metal material in the cavity 34 is reliably kept constant. At the same time, the closing operation of the mold can be accelerated.

Further, since the movable plate 46 is formed with a recess 68 for forming a part of the runner 66 and the gate 67 so as to surround the projection 58, the cooling of the metal material near the gate 67 is delayed. During the weighing process, the runner 66
The metal material returns more smoothly. On the contrary,
If there is no recess 68 and the gate is merely a side gate, the cooling of the metal material in the cavity generally proceeds faster at a position closer to the dividing surface between the fixed mold and the movable mold, so that the vicinity of the gate is cooled. Since the cooling and solidification of the metal material proceed relatively quickly, the metal material may not return smoothly from the cavity to the runner. In order to sufficiently obtain the effect of the concave portion 68, the concave portion 68 needs to have a size that is commensurate with the thickness of the product P.

After the gate 67 is closed with the closing of the mold, a compression process is performed, and the metal material in the cavity 34 is compressed. By being left, the compression is performed smoothly. After the gate 67 is closed, the metal material is not supplied into the cavity 34 from the material supply device 11, but the compression compensates for the shrinkage of the metal material in the cavity 34 due to solidification due to cooling. Of course, compression also has the effect that the cooling time in the mold apparatus 31 can be shortened.

After the metal material in the cavity 34 is sufficiently cooled and solidified, the fixed mold 32 and the movable mold 33 are opened by the mold clamping device 21. Accordingly, the metal material in the cavity 34, that is, the product P, the runner 66 and the sprue 41
The metal material solidified therein first leaves the fixed mold 32. Next, the runner 66 and the sprue
The metal material and the product P solidified in 41 are protruded and leave the movable mold 33. In addition, runner 66 and sprue
After the metal material and product P solidified in 41 are taken out, the mold is closed again, and the above steps are repeated.

As described above, according to the configuration of the above embodiment, the pressure and amount of the metal material filled in the cavity 34 can be easily and accurately determined by the pressure adjusting step and the measuring step performed in the mold apparatus 31. Therefore, it is possible to obtain a high-precision product P with stable quality and no variation in weight.

Further, in the mold apparatus 31, since the runner 66 is formed between the movable plate 46 of the fixed mold 32 and the movable mold 33, the pressure is adjusted based on the cavity 34. The metal material in the cavity 34 is smoothly runner 66
By returning to the above, the pressure and the amount of the metal material filled in the cavity 34 can be controlled more accurately.

Further, the movable plate 46 is formed with a concave portion 68 forming a part of the runner 66 and the gate 67 so as to surround the convex portion 58, so that the metal material in the cavity 34 can be smoothened during the measuring process. Can be returned to runner 66.

Further, since the metal material in the cavity 34 and the metal material in the runner 66 are cut by closing the gate 67, it is not necessary to cut off the metal material of the runner 66 by post-processing. At the same time, since the pressure and the amount of the metal material filled in the cavity 34 can be accurately controlled by the pressure adjustment step and the measurement step as described above, the mold device 31 does not need an overflow section,
There is no need for post-processing the metal material in the overflow portion.

Further, since the gate 67 is both closed and compressed by the volume adjusting means including the base 38 of the fixed mold 31 and the moving plate 46, the structure of the mold apparatus 31 can be simplified. Further, since the gas vent 71 is formed by the gap between the base 38 of the fixed mold 32 and the moving plate 46, the structure for degassing in the mold apparatus 31 can be simplified, and the mold apparatus 31 having a wasteless structure. And can be. The formation of the gas vent 71 by the gap between the base 38 of the fixed mold 32 and the moving plate 46 in this manner makes it difficult for the metal material to flow compared to the resin material and the like, and the outer peripheral surface of the pin 56 of the base 38 and the moving plate Even if the gap between the 46 and the inner peripheral surface of the through hole 57 is about 0.1 mm, this is made possible by preventing the metal material from entering the gap.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the above embodiment, the case where a hot chamber type die casting machine is used has been described as an example, but a cold chamber type die casting machine may be used. That is, various types of material supply devices are used. Also,
The mold clamping device is also a toggle type as in the above embodiment,
Various types such as a direct pressure type in which a piston of a hydraulic cylinder is directly connected to a movable side platen are used. The drive source of the mold clamping device is not limited to the hydraulic cylinder, but may be an electric motor or the like.

Further, the mold apparatus is not limited to the one in the above embodiment. For example, as the urging means for urging the moving plate 46, an air cylinder or the like can be used in addition to the spring 51. In the above-described embodiment, the runner 66 and the gate 67 are formed between the fixed mold 32 and the movable mold 33.
It is not limited to this. For example, if the product shape allows, it is also possible to adopt a direct gate that opens toward the movable mold in the mold opening and closing direction in the fixed mold.
In this case, the protrusion provided on the movable mold may be fitted to the direct gate to close it.

The present invention is not limited to a disk-shaped product, but can be applied to the formation of products of various shapes such as a ring-shaped product or a product having a more complicated shape.

[0048]

According to the first aspect of the present invention, in the measuring step after the filling step, the volume of the cavity is reduced by the volume adjusting means and the gate is closed, so that the metal material in the material passage is processed by post-processing. No need. Further, after the measuring step, the volume of the cavity is further reduced by the same volume adjusting means to compress the metal material in the cavity, so that the shrinkage accompanying the solidification of the metal material after the gate is closed can be compensated, and insufficient filling can be achieved. Nothing happens. further,
In the mold apparatus, the gate is closed and the compression is performed by the same volume adjusting means, so that the structure of the mold apparatus can be simplified.

Further, according to the second aspect of the present invention, the pressure adjusting step of adjusting the pressure of the metal material in the cavity by adjusting the volume of the cavity is performed, and then the measuring step is performed. The pressure and amount of the metal material to be filled can be easily and accurately controlled, and therefore, a high quality product with stable quality can be obtained. In addition, since there is no need to provide an overflow section in the mold apparatus, there is no need for a post-processing of the metal material in the overflow section.

According to the third aspect of the present invention, a gas vent for allowing gas to escape from the cavity to the outside is formed by the gap between the closing member and the compression member constituting the volume adjusting means of the cavity. The configuration for punching can be simplified.

[Brief description of the drawings]

FIGS. 1A and 1B are cross-sectional views of a part of a die casting die apparatus showing an embodiment of the present invention, wherein FIG. 1A shows a filling step and FIG.

FIG. 2 is a cross-sectional view of a part of the die casting die apparatus,
(A) shows the time of the measuring step, and (b) shows the time of the compressing step.

FIG. 3 is an enlarged view of the vicinity of the cavity, in which (a) is a cross-sectional view and (b) is a front view of a fixed mold.

FIG. 4 is a side view in which a part of the entire apparatus used for die casting is sectioned.

FIGS. 5A and 5B show an example of a conventional die-casting die apparatus, in which FIG. 5A is a sectional view and FIG. 5B is a front view of a movable die.

[Explanation of symbols]

 31 Mold unit 32 Fixed mold (mold) 33 Movable mold (mold) 34 Cavity 38 Base (compression member) 46 Moving plate (closing member) 66 Runner (material passage) 67 Gate 71 Gas vent

Claims (3)

(57) [Claims] A plurality of molds that open and close to each other and form a cavity therebetween when the mold is closed; and volume adjusting means for adjusting the volume of the cavity, wherein the volume adjusting means reduces the volume of the cavity. A filling step of filling the molten metal material supplied from the material supply device to the material passage into the cavity having a larger volume by using a mold device configured to close the gate from the material passage to the cavity in accordance with After the filling process, the volume of the cavity is reduced and the metal material in the cavity is returned to the material supply device side until the gate closes. After the measuring process, the volume of the cavity is further reduced to a predetermined volume to reduce the volume of the cavity. And a compression step of compressing the metal material in the die. 2. Between the filling step and the measuring step, the supply of the metal material to the cavity from the material supply device is continued, and the volume of the cavity is increased by an appropriate amount in accordance with the supply. 2. The die casting method according to claim 1, further comprising a pressure adjusting step of adjusting a pressure of the material. 3. A mold comprising a plurality of molds which open and close to each other and form a cavity therebetween when the mold is closed, wherein one of the molds abuts against another mold and closes, and slides the closure member. A compression member which is freely penetrated and forms a cavity, wherein the gate from the material passage to the cavity is closed by the compression member as the compression member moves in a direction to reduce the volume of the cavity. And a gas vent for allowing gas to escape from the cavity to the outside is formed by a gap between the closing member and the compression member.