JPS63256252A - Device for venting gas in die - Google Patents

Abstract

PURPOSE:To prevent failure of moving of movable part even if mismatching between a fixed die and a movable die occurs and to surely prevent the molten metal from leakage to out of the die by putting all of movably parts in the movable die and sliding them in the movable die. CONSTITUTION:In accordance with press-in of the molten metal 32 into a cavity 9, gas in an injecting sleeve 31 and the cavity 9 is exhausted to out of the dies through a gas vent groove 11, bypass 13, end part space 14, exhaust space 14 and exhaust passage 17. When the molten metal flows in the gas vent groove 11, it is flowed into a pressure receiving space 12 by straightly running, and tip part 18a of a pressure receiving pin 18 is pressurized, to shift toward die opening direction. Together with this, a shut-off pin 19 is driven to the same direction as the pressure receiving pin 18 through an arm 20 and an opening end part 16a of the exhaust passage 17 is shut, to prevent the molten metal reached to the end part space 14 through the bypass 13 from the leakage to the outer part. After the molten metal solidifies, an ejecting pin 26 drives the pressure receiving pin 18 and the shut-off pin 19 by an ejecting plate 23 and the solidified material from the gas vent groove 11 to the exhaust space 14 is integrately ejected with the product in the cavity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for discharging gas from a cavity to the outside when pouring metal into the cavity in a mold used for die casting or injection molding.

(Prior Art) In die casting, molten metal is injected into a mold at high speed and high pressure, but at this time, a reaction gas with a mold release agent and gases such as air are likely to be involved, causing cavities and poor drying. In order to prevent this, it is best to discharge the above gas from the cavity during pouring, and devices for this purpose are disclosed, for example, in Japanese Patent Publication No. 59-37147 and Japanese Patent Application Laid-open No. 60-626.
There is a degassing device described in Publication No. 2.

(Problems to be Solved by the Invention) However, in the gas venting device of the above-mentioned Japanese Patent Publication No. 59-37147, the valve IF! Since there is a dividing surface of the mold within the 71 range, the valve is likely to malfunction due to mold misalignment.Furthermore, since the contact surface between the valve and the valve seat is a tapered surface, the contact between the valve and the valve seat may be caused by biting of the valve and the valve seat. Because gaps are likely to occur,
There is a risk of causing a molten metal spouting accident. Furthermore, since the mold dividing surface near the valve must be uneven (stepped), it is difficult to match the molds, and there is also the problem that the installation position in the mold and the applicable mold are limited. In addition, the above-mentioned Japanese Patent Application Publication No. 60-6
In the degassing device of Publication No. 262, the dividing surface of the mold is within the operating range of the working piston, and the dividing surface of the mold must be made into an uneven shape with large steps.
In addition to having the same problems as mentioned above, the configuration of the return device that returns the opening piston that opens the exhaust passage to the open state is complicated, and the device that returns the opening piston that opens the exhaust passage to the open state is complicated. There is a risk that the gas may not be able to be discharged due to the occurrence of gas leakage.

This invention solves the above-mentioned conventional problems.Since the movable part of the degassing device is housed in the movable mold, malfunctions do not occur, and the dividing surface of the mold is made uneven for assembling the device. It is an object of the present invention to provide a gas handling device for a mold that has a simple structure and has a wide range of applications without the need for a mold gas handling device.

(Means for Solving the Problems) However, the mold gas venting device of the present invention has a gas venting groove that communicates with the cavity in the dividing surface of the mold, and an end portion of the gas venting groove. A pressure receiving chamber, a detour branching from the intermediate portion of the gas vent groove, and an end chamber formed at the terminal end of the detour are provided, and an operating chamber communicating with the pressure receiving chamber and an exhaust gas communicating with the end chamber are provided. A pressure-receiving pin having a movable chamber, a pressure receiving pin whose tip fits into the working chamber, and a shut-off pin whose tip fits into the exhaust chamber and has a valve portion that is fitted into and removed from the open end of the exhaust chamber. The pressure receiving pin and the shutoff pin are connected by an arm that is slidably supported in the movable mold in the opening/closing direction of the movable mold and interlocks the pressure receiving pin and the shutoff pin in the circumferential direction. A push pin that drives the pin and shutoff pin in the extrusion direction and returns the pressure receiving pin and the shutoff pin to their original positions when the extrusion plate returns is attached to the extrusion plate, and an exhaust passage is opened in the exhaust chamber. This is a type of gas handling device.

(Function) In the gas handling device of the present invention, as the molten metal is press-fitted into the cavity, the gas in the injection sleeve and the cavity first passes through the gas vent groove, the detour, the end chamber, the exhaust chamber, and the exhaust passage. A large amount is released outside the mold. When the m's filling the cavity flows into the gas vent groove, the wJ flow first moves straight due to inertia and flows into the pressure receiving chamber, applying impact pressure to the end face of the tip of the pressure receiving pin and molding the pressure receiving pin. Move in the listening direction. Along with this, the shutoff pin is driven via the arm in the same direction as the pressure receiving pin, and the opening end of the exhaust passage is
f1 and prevents the molten metal that has reached the end chamber via the detour from spouting out from the exhaust passage. After the molten metal solidifies, when the injection molding machine opens the mold and extrudes, the push pin drives the pressure receiving pin and the shutoff pin in the extrusion direction due to the extrusion movement of the extrusion plate, and the solidified material in the gas vent groove or exhaust chamber is removed from the capitol. It is extruded simultaneously with the product inside. After that, as the extrusion plate returns to its original position, the pressure receiving pin is pulled back and returns to its original position. Along with this, the shutoff pin is also driven via the arm and returns to its original position, completing one cycle of degassing. .

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

Figure 1 shows fixing the injection molding machine! 81 and the state of the molds attached to the movable platen 2 when the molds are closed, and a fixed mold insert 5, commonly called a nest, is shown inside the fixed main mold 3 and the movable main mold 4.
A fixed mold 7 and a movable mold 8 are formed by fixing the movable mold insert 6 with bolts or the like. Reference numeral 9 denotes a cavity for forming a product, which is recessed in each insert. A gas handling groove 11 communicating with the cavity 9 and a pressure receiving chamber 12 formed at the terminal end of the groove are provided on the dividing surface 10 of the fixed insert 5, and as shown in FIG. A detour path 13 is provided which branches from this side and joins at an end portion 13a to reach an end chamber 14. On the other hand, the movable mold insert 6 has a hole-shaped working chamber 15 that communicates with the pressure receiving chamber 12 when the mold is closed, a hole-shaped exhaust chamber 16 that communicates with the end chamber 14 when the mold is closed, and an opening in the exhaust chamber 16. An exhaust passage 17 is provided. The tip 18a of the pressure receiving pin 18 fits into the working chamber 15 with a gap between the stones, and the tip 19a of the shutoff pin 19 fits into the exhaust chamber 16 with a small gap. 18 and the shutoff pin 19 are supported by the movable mold insert 6 so as to be slidable in the mold opening/closing direction. An annular groove 190 is provided at the tip end 19a of the shut-off pin 19, leaving a short cylindrical valve part 19b at the leading edge to form a narrow diameter part. The opening end 16a of the exhaust chamber 16 can be opened by fitting into and disengaging from the chamber 16.

The intermediate portion of the shut-off pin 19 is slidably fitted into the arm 20 fixed to the pressure receiving pin 18, and the flange portion 1
When the arm 9d engages with the side surface of the arm 20, axial forces can be transmitted to each other. 21 is exhaust passage 1
This is the exhaust pipe connected to 7. Reference numeral 22 denotes a stepped shaft-shaped joint, into which the male threaded portion 18b of the pressure receiving pin 18 is screwed, thereby holding the arm 20 while holding the pressure receiving pin 1.
8 and is integrally tightened and fixed. The other end of this joint 22 is a cylindrical push pin 2 whose base is fixed to the extrusion plate 23 of the mold.
4, the stopper bolt 25 screwed into the joint 22 engages with the collar 24a of the push pin 24, and the distal end surface of the push pin 24 engages with the shoulder 22a of the joint 22. Therefore, the maximum relative movement distance between the push pin 24 and the joint 22 is limited to the distance L+ (see FIG. 3). On the other hand, a push pin 24 is provided at the base end 19e of the shutoff pin 19.
Similarly, the push pin 26 whose base is attached to the extrusion plate 23 is slidably fitted, and the distal end surface of the push pin 26 engages with the flange 19d of the shut-off pin 19, and this flange 19d and the arm. 20, the maximum relative movement distance between the push pin 26 and the shutoff pin 19 is a distance 111L2 (third
(see figure). Note that this distance L2 is larger than the distance L1. 27 is shutoff pin 1
A compression spring inserted between the push pin 9 and the push pin 26 urges the shut-off pin 19 to the right in the figure.

Next, the operation of the apparatus having the above configuration will be explained in detail.

First, as shown in FIG.
When the injection plunger 33 is advanced, the molten metal 3
2 flows into the cavity 9 as shown in FIG. , the exhaust chamber 16, the exhaust passage 17, and the exhaust pipe 21, and are discharged to the outside of the mold. At this time, gas pressure is also applied to the end of the pressure receiving pin 18 and the shutoff pin 19, but the biasing force of the compression spring 27 holds them at the original position shown in FIG. Note that if a vacuum device is connected to the exhaust pipe 21, exhausting will be further facilitated.

When the injection plunger 33 moves further forward, the molten metal 32 fills the cavity 9 and flows into the double gas groove 11. A detour 13 is provided in the middle of the gas vent groove 11, but the melt 1132, which has a larger mass than air or reaction gas, moves straight due to inertia and flows into the pressure receiving chamber 12 before flowing into the detour 13. The pressure within the pressure receiving chamber 12 is increased to pressurize the end face of the pressure receiving pin 18, and as shown in FIG.
is moved to the left in the figure, filling the working chamber 15 and also flowing into the detour 13. At this time, the pressure receiving pin 18 resists the spring force of the compression spring 27 together with the joint 22, and
2 and the push pin 24, and then stops. Also, due to this movement, the shutoff pin 19 is moved in the circumferential direction by a distance 111L+ (see FIG. 3) via the arm 20, and the valve portion 1 of the shutoff pin 19 is moved as shown in FIG.
9b opens and closes the open end 16a of the exhaust chamber 16. After filling the working chamber 15, the molten metal 32 reaches the end chamber 14 via the detour 13, so the exhaust chamber 1 is
6 is opened, and the spouting of the molten metal 32 to the outside is reliably prevented. Next, when mm32 reaches the end face of the valve part 19b of the shut-off pin 19, the pressure of the molten metal 32 is applied to the end face as well, and the shut-off pin 19 is moved between the push pin 26 and the collar of the shut-off pin 19 shown in FIG. It moves to the left in the figure by the distance [12-L+] with respect to 19d, and stops in the state shown in FIG. As a result, the force of the molten metal 32 pushing the shutoff pin 19 is not applied to the arm 20 but is directly supported by the push pin 26, so the strength of the arm 20 can be small.

FIG. 6 shows the mold opening and extrusion, and when the extrusion plate 23 moves in the extrusion direction indicated by the arrow X in the figure, the push pins 24 and 26
drive the pressure receiving pin 18 and the shutoff pin 19, which are each integral with the joint 22, in the direction of the pushing force'. The movements of the pressure receiving pin 18 and the shutoff pin 19 are synchronized with the movements of the ejector pins 34, 35 (see Fig. 1) for the cavity 9, etc., so that the gas vent groove 11, the pressure receiving chamber 12, the working chamber 15, the solidified material F in the detour 13, the end chamber 14, a part of the exhaust chamber 16, etc. is the product W solidified in the cavity 9.
It is extruded at the same time and does not cause distortion to the extruded product. When the push-out plate 23 returns to its original position, the joint 22 and the pressure-receiving pin 18 integrated therewith are pulled by the push pin 24 via the stopper bolt 25 and return to the original position shown in FIG. It is pulled back in the circumferential direction by the arm 20 and returns to its original position.

The present invention is not limited to the above embodiments; for example, in the above embodiments, the shutoff pin is slidably supported on the arm, but the shutoff pin may also be fixed to the arm; in this case, A compression spring may be provided at the push pin 24 portion, or the push pin 26 may be omitted. Alternatively, the arm may be fixed to the shut-off pin, and the arm may instead be slidably attached to the pressure receiving pin over a short distance. Further, in the above embodiment, the gas passage from the cavity 9 to the detour 13 is provided on the fixed mold side, but it can also be provided on the movable mold side.

In addition to die casting, the present invention can also be applied to molds used for injection molding of plastics and the like.

(Effects of the Invention) As explained above, according to the gas venting device of the present invention,
The following effects can be obtained.

(a) All the movable parts of this device are housed in the movable mold and slide within the movable mold, so even if misalignment occurs between the fixed mold and the movable mold, the movable parts will not malfunction, and the molten metal will Splashing out of the mold can be reliably prevented.

(b) The structure of the device is simple, requiring only a small space for installation, and there is no need to make the mold dividing surface uneven, making it easy to use with existing molds or molds with sliding cores. This device can be incorporated into a wide range of applications.

(C) Since the movement of the extrusion plate can be used to return the device to its original position and extrude it, a new actuator is not required and the operation is reliable. Furthermore, since the coagulated material in the gas vent groove or the exhaust chamber is extruded synchronously with the product in the cavity, there is less distortion in the extruded product, and mold matching using a trimming press or the like is facilitated.

(d) The operation of this device is synchronized with the mold closing, mold opening, and extrusion operations of the injection molding machine, so the cycle time remains unchanged and productivity is high.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a gas exhaust device showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIGS.
The figure is a partially enlarged view of FIG. 1, also showing the operating state. 5... Fixed type insert, 6... Movable type insert, 7... Fixed type, 8... Movable type, 9... Cavity, 10...
・Dividing surface, 11... Gas group groove, 12... Pressure receiving chamber, 1
3...Detour, 14...End chamber, 15...Working chamber, 16...Exhaust chamber, 16a...Open end, 17...
・Exhaust passage, 18...Pressure pin, 18a...Tip part, 19...Shutoff pin, 19a...Tip part,
19b...Valve portion, 20...Arm, 22...Joint, 23...Extrusion plate, 24...Push pin, 25...Stopper bolt, 26...Push pin, 27...・Compression spring.

Claims (1)

[Scope of Claims] 1. A gas vent groove communicating with the cavity, a pressure receiving chamber formed at an end of the gas vent groove, and a detour branched from an intermediate portion of the gas vent groove, in the dividing surface of the mold. and an end chamber formed at the terminal end of the detour, a movable working chamber communicating with the pressure receiving chamber and an exhaust chamber communicating with the end chamber, the tip fitting into the working chamber. A pressure-receiving pin and a shut-off pin having a distal end that fits into the exhaust chamber and a valve portion that is inserted into and removed from the open end of the exhaust chamber are inserted into the movable mold so as to be slidable in the opening/closing direction of the movable mold. The pressure receiving pin and the shutoff pin are connected by an arm that supports the pressure receiving pin and the shutoff pin in a circumferential direction, and when the extrusion plate is operated, the pressure receiving pin and the shutoff pin are driven in the extrusion direction to return the extrusion plate. At the same time, a push pin is attached to the extrusion plate to return the pressure receiving pin and shutoff pin to their original positions.
A mold gas venting device comprising an exhaust passage opened in the exhaust chamber. 2. The mold degassing device according to claim 1, wherein the arm is fixed to the pressure receiving pin, and the shutoff pin is slidably fitted to the arm.