JPS62151258A - Venting device for die - Google Patents

Abstract

PURPOSE:To prevent the ejection accident of a molten metal by providing a bypass circuit to a vent groove and disposing a shut off pin to close and open a discharge passage via an upsetting and interlocking device. CONSTITUTION:The vent groove 12 communicating with a cavity 9 and an end chamber 13 are provided to a parting plane 11 of a stationary die liner 5 and the branched bypass circuit 14 is disposed to the intermediate part of the groove 12. The shut off pin 19 of which the top end 19a fits into a discharge chamber 16 at the end of the circuit 14 is further disposed and a pressure receiving pin 18 which fits into the end chamber 13 is provided. The pins 18, 19 are connected by a lever 20 of the upsetting and interlocking device. The molten metal flows into the chamber 13 first and moves the pin 18 when the molten metal 32 is filled into the cavity 9. Then the molten metal flows into the circuit 14. The pin 19 is moved by the lever 20 to close the end of a discharge passage 17. The ejection of the molten metal 32 to the outside is surely prevented by the above-mentioned method.

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, blowholes and roughness defects are likely to occur due to entrainment of gases such as reaction gas and air. In order to prevent this, it is best to discharge gas from the cavity during pouring, and as a device for this purpose, for example,
There are degassing devices described in Japanese Patent Application Laid-open No. 147 and Japanese Patent Application Laid-Open No. 60-6262.

(Problem to be Solved by the Invention) However, in the gas handling device disclosed in Japanese Patent Publication No. 59-37147, there is a dividing surface of the mold within the sliding range of the valve, which may cause malfunction of the valve due to mold misalignment. Moreover, since the contact surface between the valve and the valve seat is tapered, it is easy to create a gap between the valve and the valve seat due to debris getting caught, which may lead to 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. Furthermore, in the degassing device disclosed in JP-A-60-6262 mentioned above, 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 closing piston that opens and closes the exhaust passage to the open state is complicated, and the device that returns the closing piston by spring force causes burrs to catch on the operating piston and the closing piston. There is a risk that the gas will not be able to be discharged and will not be able to recover.

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 gas handling device for a mold according to the present invention includes a gas venting groove that communicates with the cavity in the dividing surface of the mold, and a terminal end of the gas venting groove. An end chamber and a detour branched from an intermediate portion of the gas vent groove are provided, a working chamber communicating with the end chamber and an exhaust chamber communicating with the end of the detour are provided in a movable type, and the working chamber A pressure-receiving pin whose distal end fits and a shutter-off pin whose distal end fits into the exhaust chamber are supported within the movable mold so as to be slidable in the opening/closing direction of the movable mold, and the pressure-receiving pin and the shutter-off pin are moved in opposite directions. A reversal interlocking mechanism is provided, and an exhaust passage whose opening end is WJ'B by the shutter-off pin is opened in the exhaust chamber, and when the push-out plate is operated, the pressure receiving pin is driven in the pushing direction, and when the push-off plate is returned, the above-mentioned pressure receiving pin is driven in the push-out direction. This is a mold degassing device consisting of a push pin attached to an extrusion plate that returns the pressure receiving pin to its return position.

(Function) In the gas venting 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 venting groove, detour, exhaust chamber, and exhaust passage to the outside of the mold. Released to the crowd. When the molten metal filling the cavity flows into the gas vent groove, the molten metal first moves straight due to inertia and flows into the end chamber, applying impact pressure to the end surface of the tip of the pressure receiving pin and moving the pressure receiving pin in the mold opening direction. move it. Accordingly, the shut-off pin is driven in the opposite direction to the pressure receiving pin by the reversal interlocking mechanism to close the exhaust passage and prevent the molten metal that has reached the exhaust chamber via the detour from spouting out from the exhaust passage. After the molten metal solidifies, when the mold of the injection molding machine is opened and extruded, the push pin drives the pressure receiving pin in the extrusion direction due to the extrusion operation of the extrusion plate, and the solidified material in the gas vent groove or exhaust chamber is mixed with the product in the cavity. They are extruded as a single unit at the same time. Thereafter, 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 driven by the reversing interlocking device and returns to its original position where the exhaust passage is opened, and the End the cycle.

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

Figure 1 shows the state of the molds attached to the fixed WA1 and movable platen 2 of the injection molding machine when the molds are closed, and is commonly called a nested mold inside the fixed main mold 3 and the movable main mold 4. Fixed type insert 5
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 vent groove 12 communicating with the cavity 9 and an end chamber 13 formed at the terminal end of the groove are provided in the divided surface 11 of the fixed insert 5, and as shown in FIG. A detour 14 is provided which branches from the middle part of 12 and joins at an end 14a. On the other hand, the movable mold insert 6 has the above-mentioned end chamber 1 when the mold is closed.
3, a hole-shaped exhaust chamber 16 that communicates with the end of the detour 14 when the mold is closed, and an exhaust passage 17 that opens into the exhaust chamber 16. The tip 18a of the pressure receiving pin 18 fits into the end chamber 13 with a slight gap, and the tip 19a of the shirt 1 head off pin 19 fits into the exhaust chamber 16 with a small gap.
As a result, the pressure receiving pin 18 and the shutter-off pin 19
is supported by the movable mold insert 6 so as to be slidable in the mold opening/closing direction. 20 is a lever that is a reversal interlocking mechanism, and a pressure receiving pin 18
The intermediate portion of the lever 20 is pivoted to the movable insert 6 by a pin 21, one end is connected to the pressure receiving pin 18 by a pin 22, and the other end is connected to a pin 23. are rotatably connected to the shaft-off pin 19, respectively.

The diameter of the tip 18a of the pressure receiving pin 18 is made larger than the diameter of the tip 19a of the shutter-off pin 19, so that when the same pressure is applied to the end face of each tip, the pressing force received by the pressure receiving pin 18 is sufficiently large. It's Nishide. Further, the exhaust passage 17 is opened at a position where it can be opened or opened by movement of the tip end 19a of the shutter-off pin 19. By selecting the distance from the pin 21 to each pin 22, 23, the ratio of the amount of movement of the pressure receiving pin 18 and the shuttle pin 19 can be set to a desired value.

The other end of the five-way pressure receiving pin 18 is slidably fitted into a cylindrical push pin 26 whose base is fixed to the extrusion plate 25 of the mold. Reference numeral 27 denotes a stopper bolt that is slidably fitted in the axial direction to the collar 26a (see Fig. 3) of the push pin 26 and whose tip end is screwed into the pressure receiving pin 18, and 18b is a shoulder provided on the pressure receiving pin 18. Due to the engagement between the stopper bolt 27 and the collar portion 26a and the engagement between the tip end surface of the push pin 26 and the shoulder portion 18b, the maximum relative movement distance between the push pin 26 and the pressure receiving pin 18 is equal to the distance 1.
11tS+ (see Figure 3).

28 is a compression spring inserted between the portion 26a and the pressure receiving pin 18, and urges the pressure receiving pin 18 in the direction toward the end chamber 13.

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

First, as shown in FIG. 1, a melt 132 is placed inside the injection sleeve 31.
When the injection plunger 33 moves forward to pressurize and fill the cavity 9 with molten S32, the reaction gas from the injection sleeve 31, the air in the cavity 9, and the mold release agent flows through the gas vent groove 12 and detour 14. , the exhaust chamber 16, and the exhaust passage 17, and are discharged out of the mold. At this time, gas pressure is also applied to the end of the pressure receiving pin 18, but the pressure receiving pin 18 is held at the original position shown in FIG. 3 by the biasing force of the compression spring 28. Note that if a direct air device is connected to the exhaust passage 17, the exhaust will be further promoted.

Next, the molten metal 32 filling the gear A7 bit 9 flows into the gas vent groove 12. A detour 14 branches off from the gas vent groove 12, and the molten metal 32 is in the detour 1 whose axis is bent by 90 degrees or more.
4, it moves straight due to inertia and flows into the end chamber 13, increases the pressure in ms, pressurizes the end surface of the pressure receiving pin 18, and opens the pressure receiving pin 18 as shown in FIG. It fills the working chamber 15 and also flows into the detour 14. At this time, the pressure receiving pin 18 is
6 and then stops. This pressure receiving pin 1
8 moves the shutter-off pin 19 by 82 (see Figure 3) in the opposite direction via the lever 20,
As shown in FIG. 4, the open end of the exhaust passage 17 is closed. Note that, after filling the working chamber 15, the molten metal 32 reaches the exhaust chamber 16 via the detour 14, so the exhaust passage 17 is opened well before reaching this point, and the molten metal 32 is reliably spouted to the outside. Prevented. Furthermore, even if the molten metal 32 reaches the tip end surface of the shut-off pin 19, the pressure-receiving area of the pressure-receiving pin 18 is larger, so the shut-off pin 19 is reliably held in the closed position without retreating.

FIG. 5 shows the mold opening and extrusion, and when the extrusion plate 25 moves in the extrusion direction indicated by arrow X, the push pin 26 drives the pressure receiving pin 18 in the extrusion direction. The movement of this pressure receiving pin 18 is synchronized with the movement of the push-out pins 34, 35 (see Fig. 1) for the cavity 9, so that the gas vent groove 12 and the working chamber 1
5. The coagulated material F in the detour 14 and the like is extruded at the same time as the product solidified in the cavity 9, so that no distortion is imparted to the extruded product. When the push-out plate 25 returns to its original position, the pressure receiving pin 18 is pulled by the push pin 26 via the stopper bolt 27 and returns to its original position shown in FIG. Return to the original position where the exhaust passage 17 is opened.

FIG. 7 shows another embodiment of the present invention, in which a pinion 41 rotatably attached to the movable insert 6 by a shaft 40 is used as a reversing interlocking device for interlocking the pressure receiving pin 18 and the shutter-off pin 19 in opposite directions. It meshes with racks 42 and 43 carved into the pin 18 and the shaft-off pin 19. In this case, the movement distance of the pressure receiving pin 18 and the A7 shutoff pin 19 is the same. Note that 44 is an extrusion pin fixed to the extrusion plate 25 (see Fig. 1), and is similar to the shaft-off pin 1.
It is slidably penetrated through the interior of the detour 14 and the exhaust chamber 16 to more completely take out the coagulated material in the detour 14 and the exhaust chamber 16.

The present invention is not limited to the above-mentioned embodiments. For example, the interlocking reversing device for the pressure receiving pin and the shutter-off pin is as follows:
A configuration other than the above may be used as long as both are driven in opposite directions. Further, in the above embodiment, the gas passage from the cavity 9 to the detour 14 is provided on the fixed mold side, but it can also be provided on the movable mold side. A compression spring 28 that roughly biases the pressure receiving pin 18 in the direction toward the end chamber 13
may be provided at the shutter-off pin 19 portion.

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.

(C1 Since the movement of the extrusion plate can be used to return to the original position and extrude operation of this device, a new actuator is not required and the operation is reliable. Also, the solidified matter in the gas rear groove or the exhaust chamber is Since the extrusion with the inner product is performed in synchronization, there is less distortion of the extruded product, and mold matching using a trimming press, etc. is easy.

(d) The operation of this device is the type II of the injection molding machine, mold opening,
Since it is synchronized with the extrusion operation, the cycle time remains unchanged and productivity is high.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a gas venting device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line 8-A in FIG. 1, and FIGS. Partial enlarged view of figure 6
The figure is a sectional view taken along the line B--B in FIG. 3, and FIG. 7 is a longitudinal sectional view of the main part of the gas vented stomach, not showing another embodiment of the present invention. 5... Fixed type insert, 6... Movable type insert, 7... Fixed type, 8... Movable type, 9... Cavity, 11...
・Dividing surface, 12... Gas vent groove, 13... End chamber, 1
4...Detour, 15...Working chamber, 16...Exhaust chamber, 17...Exhaust passage, 18...Pressure receiving pin, 18a.
...Tip, 19...Shut-off pin, 1.9 a
... Tip part, 20 ... Lever, 25 ... Extrusion plate,
26...Push pin, 27...Stopper bolt, 28.
...Compression spring, 41... Binion, 42.43...
rack.

Claims (1)

[Scope of Claims] 1. A gas vent groove communicating with the cavity, an end chamber formed at the terminal 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. A working chamber communicating with the end chamber and an exhaust chamber communicating with the end of the detour are movably provided, a pressure receiving pin whose tip fits into the working chamber, and a pressure receiving pin whose tip fits into the exhaust chamber. A matching shutter-off pin is supported within the movable mold so as to be slidable in the opening/closing direction of the movable mold, and a reversal interlocking mechanism is provided for interlocking the pressure receiving pin and the shutter-off pin in opposite directions, and the opening end is opened and closed by the shutter-off pin. Gas in a mold having an exhaust passage opened into the exhaust chamber, and a push pin attached to the extrusion plate that drives the pressure receiving pin in the extrusion direction when the extrusion plate is activated and returns the pressure receiving pin to its original position when the extrusion plate returns. Extraction device. 2. The mold degassing device according to claim 1, wherein the reversal interlocking mechanism is a lever whose intermediate portion is movably supported and whose both ends are connected to a pressure receiving pin and a shut-off pin, respectively.