JP2000094112A - Gas venting device for die casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas venting device for die casting, in which molten metal is not spouted to the outer part of a die with a simple structure, even in the case of developing the pulsation in the stream of molten metal. SOLUTION: In a gas venting passage 8 communicated with a cavity in the die, a pressure receiving pin 14 and a plugging valve 15 are disposed in order from the cavity side of the gas venting passage 8 toward an exhausting hole 21 side, and each of the pressure receiving pin 14 and the plugging valve 15 is slidably arranged in the gas venting passage 8 side and in a pushing-out side in the leaving direction from the gas venting passage 8. Further, a linkage means 25 with the plugging valve 15 is provided at the pushing-out side of the pressure receiving pin 14, and at the time of clamping the die, the means 25 positions the pressure receiving pin 14 and the plugging valve 15 at the gas venting passage 8 side, transmits the working of the pressure receiving pin 14 pushed out with the fluid pressure of molten metal 28 flowing into the gas venting passage 8 so as to be delayed to the plugging valve 15, and pushes out the plugging valve 15 to the pushing-out side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degassing device for degassing a cavity in a mold casting.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 9-267162 is known as a gas venting device for mold casting. As shown in FIG. Piston 101 and piston head 102
The hot water receiving piston 101 is urged toward the inside of the ventilation pipe 100 by a spring 103, and the hot water receiving piston 101 is
And the piston head 102 are connected by a zoom link 104, and the pressure of the molten metal flowing into the ventilation conduit 100 causes the hot-water receiving piston 101 to oppose the spring 103 and the ventilation conduit 10.
When the piston is pushed out from the inside, the piston head 102 is simultaneously pushed out through the zoom link 104. In particular, the distance from the fulcrum of the zoom link 104 to the hot water receiving piston 101 is set longer than the distance from the fulcrum. hand,
Even if the pushing force of the hot water receiving piston 101 is reduced, the piston head 102 is moved by a predetermined amount to surely close the air passage. Hereinafter, in the present invention, the vent pipe will be referred to as an exhaust passage, the hot water receiving piston will be referred to as a pressure receiving pin, and the piston head will be referred to as a closing valve.

[0003]

In the above-mentioned degassing apparatus, when the molten metal is injected into the cavity, gas can be smoothly discharged from the cavity through the exhaust passage.
At the time when the molten metal starts to flow into the exhaust passage, the molten metal in the exhaust passage may cause irregular pulsation, depending on the shape of the cavity and the molten metal charging means, in which case the pressure receiving pin swings, At the same time, the closing valve also swings greatly, repeatedly opening and closing the exhaust passage, and as a result, the molten metal sometimes leaks from the outlet opening to the exhaust passage.

Accordingly, the present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to generate a pulsation in the pressure of the molten metal with respect to the pressure receiving pin, thereby changing the pressing force. Even if the pressure receiving pin swings, the closing valve keeps the open state, and when the pressure of the molten metal in the exhaust passage rises to a predetermined force or more, the mold venting device for surely closing the exhaust passage is provided. It is in.

[0005]

According to a first aspect of the present invention, there is provided a degassing apparatus for mold casting, wherein a pressure receiving pin and a closing valve are provided in an exhaust passage communicating with a cavity of the mold. Are sequentially arranged from the cavity side of the exhaust passage toward the exhaust port side, and each of the pressure receiving pin and the closing valve is slidably provided toward the exhaust passage, and is separated from the exhaust passage side of the pressure receiving pin and the exhaust passage. Slidably provided on the pushing side in the direction, and provided with interlocking means with the closing valve on the pushing side of the pressure receiving pin. The interlocking means positions the pressure receiving pin and the closing valve on the exhaust passage side at the time of mold clamping, and exhausts. The operation of the pressure receiving pin extruded by the fluid pressure of the molten metal flowing into the passage is transmitted to the closing valve with a delay, and the closing valve is pushed to the pushing side.

According to a second aspect of the present invention, in the first aspect, the interlocking means includes a rotating lever, the intermediate portion of which is opposed to the end face of the pressure receiving pin on the pushing side, and the free distal end is engaged with the closing valve. It rotates by pushing the pressure receiving pin,
It is characterized in that the closing valve is pushed out from the exhaust passage to the pushing side with a delay.

The exhaust passage is provided with a main path leading to the cavity and a detour branching off from the main path as in the prior art, but a pressure receiving pin is provided at a branch point between the main path and the detour.
It is characterized in that a closing valve is provided at the end of the detour.

When the push-out of the pressure receiving pin in the direction away from the exhaust passage is transmitted to the closing valve with a delay, the closing valve immediately responds to the operation of the pressure receiving pin without closing the exhaust passage. Refers to the operation that is delayed from the operation of the pressure receiving pin.

The turning lever of the interlocking means rotatably supports one end of the turning lever, and is opposed to the pressure receiving pin.
It is simply in contact with the pressure receiving pin without being joined, and furthermore, the free tip is engaged with the closing valve,
It is in a state of being inserted into a hole provided in the closing valve.

[0010]

When the mold is clamped, the pressure receiving pin and the closing valve are located on the side of the exhaust passage, and the exhaust passage is kept open. As the molten metal is injected into the cavity, the gas in the molten metal is released. Is discharged from the discharge port through the exhaust passage, the pressure receiving pin, and the closing valve, and when the molten metal flows into the exhaust passage with the discharge of the gas, the pressure receiving pin is pushed out of the exhaust passage by the molten metal pressure.

When the pressure receiving pin is pushed out of the exhaust passage, the pressure receiving pin presses the intermediate portion of the rotating lever of the interlocking means. As a result, the free distal end of the pivoting lever pushes the closing valve slightly out of the exhaust passage, but does not close the exhaust passage, so that the gas discharge is continued. Even if there is a pulsation in the flow pressure of the molten metal passing through the exhaust passage, the rotary lever abuts on the pressure receiving pin and only engages with the closing valve, so that the closing valve is completely pushed out of the exhaust passage and closed. Never.

Since the closing valve actuated by the pivoting lever has not yet completely closed the exhaust passage, the gas in the bypass of the exhaust passage continues to be discharged, but when the molten metal reaches the closing valve, the molten metal is closed. The pressure causes the closing valve to be pushed out, thus completely closing the exhaust passage. The molten metal that has flowed into the exhaust passage rises in pressure when branching from the main path to the detour and changing the flow direction, and every time the flow direction is changed in the detour, acts as a pushing force of the pressure receiving pin. The lifting force is transmitted to the closing valve via the turning lever, and the closing valve is operated in the closing direction of the exhaust passage before the molten metal reaches the closing valve.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a degassing apparatus for mold casting according to the present invention will be described below with reference to FIG. 1. 1 is a fixed main mold, 2 is a movable main mold, 3 is a cavity fixed mold, and 4 is a fixed main mold. Cavity movable mold 5 is a cavity, and fixed main mold 1
In addition, an injection sleeve 6 communicating with the cavity 5 is provided, a molten metal 28 is press-fitted into the cavity 5 by an injection piston 7 from the inside of the injection sleeve 6, and an exhaust passage 8 provided continuously to the cavity 5 is extended to a degassing device 9. The degassing device 9 includes a fixed portion 10 provided on the fixed main die 1 and a movable portion 11 provided on the movable main die 2. In the figure, 12 is a pressing plate, and 13 is an extrusion pin.

As shown in FIG. 2, the degassing device 9 is provided with the exhaust passage 8 on the mating surface of the fixed portion 10 and the movable portion 11, and the exhaust passage 8 is moved right and left from the main path 8a as shown in FIG. There is provided a detour 8b that branches and merges again, and the push pin 13 is provided to face the main path 8a and the left and right detours 8b. The fixing portion 10 arranges the pressure receiving pin 14 and the closing valve 15 in the exhaust passage 8 communicating with the cavity 5 in order from the cavity 5 side of the exhaust passage 8 toward the discharge port 21. 15 are slidably provided on the exhaust passage 8 side and on the pushing side in the direction away from the exhaust passage 8,
In addition, an interlocking means 25 for interlocking with the closing valve 15 is provided on the pushing side of the pressure receiving pin 14, and the interlocking means 25 positions the pressure receiving pin 14 and the closing valve 15 on the exhaust passage 8 side when closing the mold,
The operation of the pressure receiving pin 14 extruded by the fluid pressure of the molten metal 28 flowing into the exhaust passage 8 is transmitted to the closing valve 15 with a delay,
The closing valve 15 is pushed out to the pushing side.

The pressure receiving pin 14 has a flange 16 and a projection 17 on the pushing side, and is disposed so as to face a branch portion of the main path 8 a in the exhaust passage 8. And is set so as to be substantially flush with the mating surface of the fixed portion 10 without entering the exhaust passage 8.
Side and the pushing side in the direction away from the exhaust passage 8. Further, a concave portion 18 or a convex portion is provided on the distal end surface of the pressure receiving pin 14 for the purpose of obtaining a release resistance.
When it is formed, it is preferable that the width of the back is larger than the width of the entrance.

The closing valve 15 includes a valve cylinder 19
And a valve rod 20 that is slidably inserted into the valve cylinder 19. The valve rod 19 is disposed to face the confluence of the bypass 8 b, and the valve cylinder 19 is provided with a valve seat 24 on the exhaust passage 8 side. The valve stem 20 has a valve portion 22 on the exhaust passage 8 side to abut the valve portion 22 to close the exhaust passage 8, and further provides a release resistance to the valve portion 22. The projection 23 is provided.

One end of the rotating lever 26 of the interlocking means 25 is rotatably supported, and an intermediate portion thereof is opposed to an end surface on the pushing side of the pressure receiving pin 14, that is, the projection 17, and a free front end is closed. The pressure receiving pin 14 is engaged with a lateral hole 27 provided in the valve 15, and is rotated by the pushing of the pressure receiving pin 14 from the exhaust passage 8, so that the closing valve 15 is pushed out of the exhaust passage 8 in the pushing direction with a delay. As the delayed operation of the closing valve 15, a leaf spring having a spring property can be used for the rotation lever 26, or a coil spring is provided between the rotation lever 26 and the flange 16 of the pressure receiving pin 14, and It is also possible to adjust the delay of the closing valve 15 depending on the strength.

[0018] When the above-described degassing apparatus for mold casting is mounted on a mold for casting, degassing is performed by the following operation. When the injection piston 7 is driven to press the molten metal 28 into the mold shown in FIG. 1, the molten metal 28 flows into the cavity 5, and the gas in the cavity 5 passes through the main passage 8 a of the exhaust passage 8 to the pressure receiving pin 14. Even when the pressure reaches, the pressure receiving pin 14 is not pushed out and reaches the bypass 8b, reaches the closing valve 15, and is discharged from the closing valve 15 through the discharge port 21 to the outside of the mold.

The molten metal 28 press-fitted into the cavity 5 flows from the cavity 5 into the main passage 8a of the exhaust passage 8, and
As described above, at the branching point between the main path 8a and the detour 8b, the flow direction changes and the pressure rises due to stagnation, and when it starts flowing into the detour 8b, the pressure decreases. In addition, the pressure rises stagnate, and then drops when the fluid flows further, and rises to the maximum at the confluence of the left and right detours 8b. Therefore, the pressure receiving pin 14 is pushed out by the pressure rising section. The rotation lever 26 is rotated in accordance with the pushing of the pressure receiving pin 14, but only contacts the pressure receiving pin 14 and is engaged with the valve rod 20 of the closing valve 15. As it is slightly pushed out from the 8 side and does not close the exhaust passage 8,
The gas in the bypass 8b continues to be discharged.

The molten metal 28 flows from the bypass 8b to the closing valve 15
At first, since only the fluid pressure of the molten metal 28 is at first, the flow is blocked by the valve portion 22 and does not flow out from the gap between the valve portion 22 and the valve seat 24. However, as the pressure of the molten metal 28 flowing to the detour 8b increases, the pressure of the molten metal acting on the pressure receiving pin 14 increases as the pressure of the molten metal in the detour 8b increases.
Is largely pushed out, and the turning lever 26 is strongly turned, whereby the free end instantly pushes the valve rod 20 in the pushing direction, and the closing valve 15 is completely closed as shown in FIG. Even if the molten metal 28 reaches the closing valve 15 from the detour 8b before the closing valve 15 is completely closed by the rotating lever 26, the molten metal 28 initially is only the fluid pressure. 24 does not flow out to the discharge port 21 through the gap.

After the molten metal 28 is solidified, the mold is opened as shown in FIGS.
8 is formed with a wide inner portion, and a convex portion 23 is provided at the tip of the closing valve 15, so that the surplus member 29 of the molten metal 28 solidified in the exhaust passage 8 is provided with the concave portion 18 of the pressure receiving pin 14. Since the protrusion 23 of the closing valve 15 is locked, the cast product and the surplus member 29 are
The pressure receiving pin 14 and the closing valve 15 are removed from the mold by the pushing pin 13 and the excess member 29 removed from the mold.
Is returned to the original position and is located on the exhaust passage 8 side.

The degassing apparatus for mold casting shown in FIGS.
In a modification of the closing valve 15, a valve portion 22 provided on a valve stem 20 is formed like a piston of a cylinder, and the valve stem 20 is inserted into a valve cylinder 19 and a discharge port 21 is provided. To prevent the molten metal 28 from flowing out. Other structures and operations are the same as those in the above-described example.

[0023]

As described above, the degassing apparatus for mold casting of the present invention has the following effects. The degassing apparatus for mold casting according to the first aspect of the present invention is provided with a pressure receiving pin operated by the pressure of the molten metal, and the operation of the pressure receiving pin is transmitted to the closing valve with a delay through the interlocking means. Even if the melt pressure pulsates, the melt pressure is not immediately transmitted to the closing valve, and the closing valve is closed when the melt pressure in the exhaust passage rises above a predetermined pressure.
As a result, it is possible to reliably prevent the molten metal from being ejected to the outside of the mold. According to a second aspect of the present invention, in addition to the effects of the first aspect, the interlocking means includes a rotating lever, an intermediate portion of which is opposed to the pressure receiving pin, and a free tip portion is connected to the closing valve. Because of the engagement, the pushing of the pressure receiving pin can be reliably and reliably transmitted to the closing valve.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an outline of a mold provided with a degassing device according to the present invention.

FIG. 2 is a sectional view showing a degassing apparatus for mold casting according to the present invention.

FIG. 3 is a plan view showing an exhaust passage.

FIG. 4 is a cross-sectional view showing a state at the time when molten metal flows into a main path of an exhaust passage.

FIG. 5 is a cross-sectional view showing a state in which the molten metal has reached a closing valve position.

FIG. 6 is a cross-sectional view showing a state at the beginning of mold opening.

FIG. 7 is a cross-sectional view showing a state when a cast product is extruded.

FIG. 8 is a cross-sectional view showing a mold-clamped state of a degassing apparatus for die casting according to the present invention.

FIG. 9 is a sectional view showing the medical state.

FIG. 10 is a sectional view of a conventional degassing device.

[Explanation of symbols]

 5 Cavity 8 Exhaust passage 14 Pressure receiving pin 15 Closing valve 21 Discharge port 25 Interlocking means 26 Rotating lever 28 Molten metal

Claims (2)

[Claims] An exhaust passage (8) communicating with a cavity (5) of a mold has a pressure receiving pin (14) and a closing valve (1).
5) are sequentially arranged from the cavity (5) side of the exhaust passage (8) to the discharge port (21) side, and the pressure receiving pin (1) is arranged.
4) and the closing valve (15) are connected to the exhaust passage (8) side,
And an interlocking means (25) to the closing valve (15) on the extruding side of the pressure receiving pin (14), provided slidably on the extruding side in the direction away from the exhaust passage (8).
In 5), the pressure receiving pin (14) and the closing valve (15) are located on the side of the exhaust passage (8) when the mold is clamped, and are extruded by the fluid pressure of the molten metal (28) flowing into the exhaust passage (8). A degassing device for die casting, characterized in that the operation of the pressure receiving pin (14) is transmitted to the closing valve (15) with a delay, and the closing valve (15) is pushed out to the extrusion side. 2. The interlocking means (25) includes a rotating lever (26).
The rotation lever (26) has an intermediate portion facing the end face on the pushing side of the pressure receiving pin (14), a free front end portion engaged with the closing valve (15), and the rotation of the pressure receiving pin (14). The degassing device according to claim 1, characterized in that the device is rotated by the extrusion and is delayed from the exhaust passage (8) toward the extrusion side by delaying the closing valve (15).