JPH0312991B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The industrial application field of the present invention relates to a die casting mold device, and more specifically, to degassing gas in the cavity of a mold having a core. This invention relates to a die casting mold device with an improved structure.

[Conventional technology]

For example, in a die-casting machine that forms die-cast products using aluminum alloy, etc.,
Molten aluminum alloy is injected into a mold cavity formed between a stationary mold and a movable mold that are butted together.

However, air remains in the mold cavity, and if it is not degassed, this air will be drawn into the molten metal, creating cavities.

Therefore, various degassing devices have been proposed to perform degassing.

On the other hand, some die casting machines use a plurality of cores when molding, for example, aluminum wheels.

In such a case, injection molding is performed only after a plurality of cores are put together.

[Problem that the invention seeks to solve]

However, the degassing device must be installed on the butting surface of the mold, and when multiple cores are used, the location of the degassing device becomes an important issue, and the arrangement structure is an extremely difficult problem. Injection molding was carried out without a degassing device.

Even if a degassing device is installed on the butting surface of the mold, the degassing passage connecting the mold cavity and the degassing device is located on the butting surface of the mold and the core, and the butting surface of the cores. Because they are installed along the same line, when the mold is opened after injection and all the cores are moved back, the abutting surfaces of the cores will naturally separate, so the degassing passage provided between the butting surfaces of the cores will naturally separate. A portion of the solidified molten metal that has entered the core separates from the cores on both sides and remains floating in the air.

In this case, it is not so much of a problem that the solidified material in the degassing passage is exposed to the air, but when the core is retracted, if the core is retreated with this solidified material attached to one of the cores. Not only does the solidified material in the degassing passage portion bend, but the deformation may sometimes have an adverse effect such as distortion of the product shape.

[Means for solving problems]

In order to solve the above-mentioned problems in the present invention, a degassing device is provided on the mold dividing surface or the core abutting surface, and a degassing passage is arranged along the core dividing surface and the mold dividing surface, A pin is provided on the abutting surface of the cores facing the degassing passage so as to be slidable in the same direction as the moving direction of the cores, and this pin can be made to protrude into the degassing passage when the cores are open. A structure with a mold release holding device was adopted.

[Effect]

If the structure described above is adopted, the installation of the degassing device becomes extremely easy, and even if a plurality of cores are involved, the degassing can be ensured, and no cavities will be formed in the product.

Furthermore, in the present invention, when opening the mold and retracting the core, the runner portion, which is the solidified molten metal in the degassing passage, is held by the pin of the mold release holding device at the beginning. The solidified matter here does not adhere to the core and is reliably separated from the degassing passage of the core. Then, the solidified material here becomes bent,
There is no deformation or adverse effect on the product.
Note that once this solidified material has been reliably separated from the wall surface of the degassing passage of the core, there is no problem even if the pin of the mold release holding device separates from this solidified material.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on embodiments shown in the drawings.

FIG. 6 illustrates an example of a degassing device applied to the present invention. In the figure, 1a is the insert of the fixed mold 1, 2a is the insert of the movable mold 2, and each of the fixed molds is 1 and the inserts 1a and 1b forming a part of the movable mold 2 are butted against each other at the parting surface 13 thereof.

Here, the insert shown as 1a has a tapered inner circumferential surface that is held in contact with the tapered outer circumferential surface of each core 11 when a plurality of cores 11 are moved forward and butted and when the mold is clamped, which will be described later. It constitutes a retaining ring 1a.

What is indicated by the reference numeral 14 is a cavity.

Ventilation passages 41, also called venting grooves, are formed on both sides of the dividing surface 13, on the abutting surfaces of the core and on the abutting surfaces of the inserts 1a and 2a, in communication with the cavity 14. A mold gas venting device indicated by reference numeral 42 is located on the same axis as the terminal end of the gas venting groove 41, and is fixed, for example, to the movable mold 2 side. That is, a cylinder 44 is attached to the tip of a bracket 43 fixed to the movable mold 2 side, and an end flange, which is the working end of a piston rod 45 that moves back and forth using the fluid pressure, is equipped with a cylinder 44.
A cylindrical spool 46 has a tip end attached to both inserts 1a and 2.
It is fixed by being removably inserted into the circular hole in the end face of a. When the mold is clamped or opened, the spool 46 is inserted into and removed from the inserts 1a and 2a via the piston rod 45 by the operation of the cylinder 44. At the tip of the spool 46 inserted into the inserts 1a and 2a, there is a valve chamber 47,
A bypass 48 is provided which detours laterally to communicate between the valve chamber 47 and the gas vent groove 41, and
A valve seat 4 facing the valve chamber 47 is provided on the tip surface of the spool 46.
9 is formed. A pair of elongated holes 50 provided in the outer peripheral wall of the spool 46 are provided with both rod portions 5 of the return rod 51.
1a is slidably engaged, and between the return rod 51 and the flange portion of the piston rod 45, there is a tension spring 52 that urges the return rod 51 upward, a cylinder, a solenoid device, a gravity device, etc. The members are stretched. Below the return rod 51, a valve guide 53 integrally formed with a cylindrical portion 53a and a pair of screw hole portions 53b is fixed to the spool 46 through a long hole 50 in the screw hole portion 53b.
A valve rod 56 whose one end threaded portion is screwed into a screw hole of the return rod 51 is slidably supported on the valve 3a.
As the lower end of the valve stem 56 rises, the valve seat 4
A valve body 56a is provided which is seated at the spool 46, and the open valve body 56a is seated due to the inertia of the molten metal advancing from the cavity 14, and is connected to the inner chamber of the spool 46, the gas vent groove 41, and the bypass 48. It is configured to block the gap between Reference numeral 57 denotes a ball that engages with the groove 56b of the valve stem 56 by the bias of the compression coil spring 58, and these balls form a locking mechanism, and the valve body 56a is closed once by the pressure of the molten metal. is constructed so that it will not open again unless an external force is applied. 54 is a bolt, and 55 is a nut. Note that the valve body 56a is opened by pushing down the rod portion 51a of the return rod 51. Reference numeral 59 is a stopper that restricts the retracting limit of the spool 46 that is retracted by the operation of the cylinder 44, and is fixed to the bracket 43 so that the rod portion 51a of the return rod 51 comes into contact with it. Then, the valve body 56a of the spool 46
An exhaust hole 60 is opened on the side, and this exhaust hole 60 is connected to a pneumatic circuit (not shown).

On the other hand, FIGS. 1A and 1B illustrate the main parts of a die-casting machine to which a gas venting device 42 having the above-described structure is attached, and shows the die-casting state.

In the figure, the reference numeral 1 indicates a fixed mold, and the reference numeral 2 indicates a movable mold, which are attached to the fixed platen 3 and movable platen 4 sides, respectively.

In the center of the fixed mold 1 is a plunger 5 for injection.
An injection sleeve 6 into which is fitted is arranged,
Its upper end faces into the mold cavity. A product ejection pin 7 is provided on the movable mold 2 side. The reference numeral 8 indicates an aluminum wheel which is an example of a molded product.

By the way, in this embodiment, the number of cores 11 is 4.
There are two types, each spaced 90 degrees apart. While the movable platen 2 and the insert 2a move vertically, each core 11 moves horizontally. Of course, each core 11 is moved forward and backward by the cylinder 9, respectively. Moreover, as shown in FIG. 1B, both sides of each core 11 are parallel planes, and the cores 11 are arranged at four locations.
a, 1a.

In this embodiment, the gas venting device 42
is provided on the movable mold side, facing the dividing surface of both molds and a pair of inserts 2a, 1a.

Further, the degassing groove (degassing passage) 41 is arranged along the dividing plane of the opposing pair of cores 11, 11 and the dividing plane of the pair of inserts 2a, 1a.

By the way, since the degassing passage 41 of the degassing device 42 mentioned above is naturally a space, the molten metal is also introduced into this part, solidifies, and blocks the degassing passage 41.

A part of the runner 8a, which is a solidified object in this degassing passage 41, is removed when the mold is opened.
As shown in FIG. 4A, both molds 1 and 2 and core 11
be completely separated from.

For this reason, a release holding device which also served as a runner holding device as shown in FIG. 2 was provided on the abutting surfaces of the cores 11.

That is, guide blocks 61 and 62 are fixed at the abutting surfaces of the cores 11 and 11 facing each other and surrounding the degassing passage 41, and two extrusion pins 63 and 64 are attached to each block. Block 61,6
The tip of one pin 63 faces the degassing passage 41, and the tip of the other pin 64 faces the opposing blocks 61, 62.
It was provided so that it could come into contact with the abutting surfaces of. However, the axes of the pins 63 and 64 are made to coincide with the opening direction of the core 11.

Then, connect the rear ends of the respective pins 63 and 64 to the core 1.
1 is supported by a support plate 65 that is slidably fitted into the inside of the support plate 1, and this support plate 65 is pressed by a pressing device such as a spring 66.

Although FIG. 2 shows the support plate 65 and spring 66 attached to only one side of the core 11, the same structure is provided on the other opposing side of the core 11. There is.

If such a structure is adopted, the cores 11, 11 and the block 6 will be removed during molding, that is, during mold clamping.
1 and 62 are abutted against each other, and the tip surfaces of both pins 64 are in contact with the abutting surfaces of the mating blocks 61 and 62, so the pins 63 and 64 are pushed against the blocks 61 and 62 against the force of the spring 66. The pin 63 is pushed back inward, and the tip end surface of the pin 63 is retracted to the wall surface of the degassing passage 41. When the core moves backward, the action of the spring 66 causes the pins 63 and 64 to
is extruded, and the solidified metal in the degassing passage 41 can be reliably released from the mold and can be held at the initial stage of core retraction.

Next, the operation of this embodiment configured as above will be explained.

During molding, as shown in FIGS. 1A and 1B, the fixed mold 1 and the movable mold 2 including the inserts 1a and 2a are closed, the core 11 is also closed, and the aluminum wheel which is the molded product is closed. 8 is formed in the cavity.

In this state, the plunger 5 is fitted and the injection sleeve 6 containing the molten metal is pressed against the fixed mold 1, and by the action of the plunger 5, the molten metal is supplied into the mold cavity and the injection operation is performed. It will be done.

At this time, the gas venting device 42 is open and the gas in the cavity is discharged. Eventually, when the molten metal advances to the degassing device 42 section, the valve body 56a of the degassing device 42 is closed by the action of the inertia of the molten metal, and the degassing passage 41 is also filled with the molten metal.

Subsequently, the movable mold 2 is moved as shown in FIG. 3A, and the mold is opened.

At this time, the aluminum wheel 8 is attached to the movable mold 2 side, and the degassing device 42 also moves together with the movable mold 2.

Subsequently, the core 11 is retracted by the cylinder 9 as shown in FIGS. 4A and 4B. When the core 11 is retreated, the runner part 8a, which is separated from the degassing passage 41 and exposed in the air, is moved by the pins 63, shown in FIG.
64 in a pressed state from both sides.

In this case, at the beginning when both cores 11 retreat,
Even if the core 11 moves back, the tip of the pin 63 pushes the runner part 8a, which is the solidified molten metal in the degassing passage 41, and holds it in its original position due to the action of the spring 66, so that the solidified material here The runner part 8a is
is surely separated from the degassing passage 41 and exposed to the air. Therefore, the runner portion 8a will not bend or deform, which will not adversely affect the product. Note that after the runner part 8a is securely separated from the wall surface of the degassing passage 41, the tip of the pin is attached to the runner part 8a.
Even if the runner part 8a is separated from the runner part 8a, the runner part 8a will no longer be deformed, so there will be no adverse effect on the product. Subsequently, as shown in FIG. 5A, the product ejection pin 7 is activated, and the aluminum wheel 8 is released from the mold and taken out by the product removal device 12.

After the product is taken out, the mold is clamped again.
The steps described above are repeated.

〔effect〕

As is clear from the above description, according to the present invention, a degassing device is provided on the abutting surfaces of the molds of a die-casting machine having a plurality of cores and on the abutting surfaces of the cores, and the degassing passage is connected to the molds and the abutting surfaces of the cores. Since the structure is installed along the butting surfaces of the cores, even if the mold has a complex structure with multiple cores, it can be degassed reliably and products of excellent quality can be obtained. can.

In addition, a release holding device is installed on the butting surface of the core that faces the degassing passage and pushes out and holds the solidified metal in the degassing passage, so when the core opens, the solidified metal in the degassing passage It is possible to reliably release and hold metal. Therefore, the product will not be twisted due to excessive force applied to the product, nor will it fall or be damaged when the mold is opened, and the product can be obtained safely and reliably at all times.

[Brief explanation of the drawing]

The figure explains one embodiment of the present invention.
Figures A and B are a longitudinal sectional front view and a bottom view on the movable mold side in the casting state, Figure 2 is a cross-sectional view showing the mold release holding device in the degassing passage, and Figures 3 A and B are in the mold open state. Vertical front view and bottom view of the movable mold side, Figures 4A and B
5A and 5B are a longitudinal sectional front view and a plan view of the product when the product is taken out, and 6A is a longitudinal sectional view of the degassing device. , FIG. 6B is a sectional view taken along line A--A in FIG. 6A. 1...Fixed mold, 2...Movable mold, 1a, 2a...Obtain, 3...Fixed plate, 4...Movable plate, 5...Plunger,
6... Injection sleeve, 7... Extrusion pin, 8... Aluminum wheel, 11... Core, 41... Degassing passage (gas venting groove), 42... Gas venting device, 63, 64... Pin,
66...Spring.

Claims (1)

[Claims] 1 The movable mold has a fixed mold on the lower side and a movable mold on the upper side, and a plurality of cores that can be butted together by moving the fixed mold and the movable mold horizontally forward to each other. In the mold device of a die-casting machine for molding a disk wheel-like product, which is slidably attached to a disk wheel, the tapered outer circumferential surfaces of each core come into contact when the plurality of cores move forward and butt and when the mold is clamped. A retaining ring with a tapered inner circumferential surface to be held is placed on the fixed mold side, and a gas venting device is provided on the mold abutting surface of the fixed mold and the movable mold or the core abutting surface, so that the mold and A degassing passage connecting the mold cavity and degassing device is provided along the abutting surfaces of the cores and the abutting surfaces of the cores, and a pin is installed at the abutting surface of the cores facing the degassing passage. A mold device for die casting, which is provided with a release holding device that is slidably provided in the same direction as the moving direction of the core, and allows the pin to protrude into the degassing passage when the core is open.