JPS62259653A - Venting device for die - Google Patents

Abstract

PURPOSE:To surely and adjustably execute the work of a valve body and to improve the reliability and durability of the device by arranging vertical penetrating small holes in a barrel part of the upper and lower pressurizing piston at the tip of supporting rod for the valve body inserting into the venting groove of a die and a horizontal hole connecting to the upper part. CONSTITUTION:The molten metal ascended from the 1 venting groove 10 is bumped against the recess part of the valve body 22 and the valve body 22 is pushed up by this impact, to abut the valve seat 17e on a spool step part and shut a by-pass 12 for the molten metal. The piston 20 at the tip of the valve rod 21 supporting the valve body 22 is fitted as sliding to the upper spool 17b. In case of pressurizing the upper part of the piston 20 through the small hole 20b from a port 27 by working a change valve 31, the valve body 22 is opened and even if any ascending accident is occurred, the open state is stabilized. On the other hand, in case of pressurizing the lower part of the piston from the port 26 by cutting off the change valve 31, the valve body 22 is under open state by equal pressure to the upper part and the lower part through the small hole 20a, but by pushing up the molten metal, the valve body 22 is perfectly shutted as exhausting gas from the small hole 20b to the port 27. Further, the change valve 30 executes surely the push-down and the push-up.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mold gas venting device for extracting gas from a mold cavity during injection molding using an injection molding device such as a die casting machine or an injection molding machine. be.

[Conventional technology]

Conventionally, in injection molding equipment such as a die casting machine, a bath melt is injected and filled into a cavity at high speed and high pressure.
The gas inside the cavity may remain in the product without being vented, resulting in the formation of cavities in the product.

Therefore, the applicant has developed a degassing device for molds that can remove a large amount of gas in a short time. This gas venting device consists of a gas venting groove that communicates with the cavity, a box 3 that slides in the axial direction at the end of the groove, and a bypass as a gas exhaust passage that detours from the middle of the gas venting groove to the side of the gauge section. of,
In preparation for the separation surface of the mold, gas in the cavity during injection molding is drawn out of the mold through the bypass and the valve body opening, and the injected molten material fills the cavity and fills the gas vent groove. When the end is reached, the valve body is pushed up by the action of this large-mass molten material, so that the valve body closes the end of the bypass.

However, in this degassing device, the operation of the valve body is not always satisfactory, especially when the melt becomes discontinuous at the tip of the flow and spreads over the valve body. There were times when it didn't work. In other words, even if the valve closes once due to the action of the molten material, the next time gas comes, it will open due to the action of the compression spring installed at the rear end of the valve, and then the molten material will come again and try to close the valve. Then, since the molten material in front of the valve position that came earlier is about to solidify, the force of the molten material that came later does not act directly on the valve, but acts on the molten material that comes before. At this time, since there is frictional resistance between the molten material that is solidifying first and the surrounding mold surface, the force exerted on the valve by the molten material that comes later becomes weaker, and the valve is not fully formed. It sometimes did not close, and there was a risk that melt entering the bypass could enter the valve chamber through the valve opening.

Therefore, the present applicant proposed a degassing device as disclosed in Japanese Patent Publication No. 59-310. This degassing device includes a member such as a tension spring that biases the valve in the closing direction, and a member such as a compression spring and ball that locks the valve in the open position. The valve is designed to close against the locking force of a member such as,
It is possible to quickly and reliably close the valve body when the first bath melt reaches the valve body.

[Problem that the invention seeks to solve]

However, such conventional degassing devices are not necessarily satisfactory in terms of maintaining the locking force in the open position of the valve for a long period of time. In other words, if the cell is repeatedly opened and closed during each injection cycle, the ball, leaf spring, and their contact parts will wear out, and the locking force will decrease, causing the valve to close before the molten material arrives. , and there was a risk that it would become impossible to vent the gas. On the other hand, if the contact surface of the ball becomes rough or deformed, the locking force at the valve open position will become stronger, and even if bath melt comes, the locking force will exceed the collision force and the valve will not close. As a result, there was a problem in that molten material entered the valve chamber.

[Means for solving problems]

In order to solve such problems, in the present invention, a piston that fits into the spool inner hole is fixed to the end of the valve stem on the side opposite to the valve body, and the piston opens into a chamber on the side of the valve body and a chamber on the side opposite to the valve body, respectively. Two ports are provided, one is blocked by the outer circumferential surface of the piston, and the other is in the center and communicates with the valve body side chamber or the opposite side of the piston, and these ports are switched between each port and the pressure fluid source. Connected by piping with a valve.

[Effect]

Until the bath melt in the cavity reaches the gas vent hole, the valve is open and the piston head side 1 and the center port are shut off, or the piston head side and the center port are closed. Even if the device is in communication with the valve, the valve is held open due to pipe resistance. When the molten metal reaches the valve body at the end of the gas vent groove, the valve is pushed and moved in the valve closing direction, completely closing. Once the valve is closed, it remains closed due to the fluid pressure acting on the rod side of the piston. In this case, the valve is held closed also by resistance in the pipeline such as a small hole provided in the piston.

〔Example〕

Figures 1 to 4 show the mold gas i'ai according to the present invention.
An example is shown in which it is applied to the mold of an IT-die casting machine. Figure 1 is a longitudinal cross-sectional view of it, Figure 2 is a longitudinal cross-sectional view of the main parts and a pneumatic circuit diagram, and Figure 3 is a degassing device and its implementation. FIG. 4 is a longitudinal sectional view corresponding to FIG. 1 showing the degassing device separated from the mold. In the figure, a cavity 4 is formed in the dividing surface 3, which is the joint surface between the fixed mold 1 and the movable mold 2, which are shown in a closed state. Bath water 1 is injected and filled through the fixed sleeve part 5 and gate 6. 8 is the product obtained by solidifying the bath water 7, after opening the mold, oT! This is a product extrusion device that extrudes a product from a cavity 4 of a 4tl mold 2. A spool hole 11 is opened to the outside at the upper end of the dividing surface 3 of the molds 1 and 2 and communicates with the cavity 4 through a gas venting path 9 and a gas venting groove 10. A bypass 12 that branches off and detours from the middle is communicated with the opening of the gas vent groove 10 to the spool hole 11.

A fluid pressure cylinder 14 is fixed concentrically with the gas vent groove 10 on a bracket 13 fixed to the upper surface of the fixed mold 1, and a flange 15 and a flange 15, which is the active end of a piston rod 15 that moves back and forth with the fluid pressure, are fixed on a bracket 13 fixed to the upper surface of the fixed mold 1. A holder 18 is fixed to the holder 18, which holds the upper end of the spool 1T of the degassing device, which is generally indicated by the reference numeral 16. The spool 17 is formed into a cylindrical shape with a bottom, and a stepped portion 17a is provided at the lower end of the spool 17. As the piston rod 15 advances and retreats, the entire gas venting device 16 moves up and down, and the stepped portion 17a engages with the spool hole 11. The spool holes 11 are arranged so as to be aligned with each other, or to be spaced apart from the spool hole 11 as shown in FIG.

Therefore, the gas venting device 16 will be described below with respect to the usage conditions shown in FIGS. 1 to 3. The spool 17 is divided into upper and lower members 17b and t7c, and the flange of the valve guide 19 fitted in the inner hole 17d is held between the upper and lower members 17b and t7c. are integrated.

A piston 20 is located above the valve guide 19 and is slidably fitted into the inner hole 17d of the spool 17, and has a central threaded hole that allows the piston to move forward and backward into the inner hole 19& of the valve guide 19. A threaded portion of a valve rod 21 that is fitted and passes through the inner hole 17& of the spool 17 is screwed in and comes out as an integral part, and a valve body 22 is integrally formed at the lower end of the valve rod 21. On the other hand, a valve seat 17e is formed at the lower open end of the spool 1T, and the valve body 22 and the valve seat 17e are connected to each other by the pressure of the molten metal 7 rising in the gas vent groove 10 from the open state shown in the figure. When pressed, it is configured to rise and enter the closed state. In addition, in the illustrated valve open state, the valve body 22 engages with the opening step of the gas vent #110 to close it. Reference numeral 17f in FIG. 2 is a discharge hole for discharging to the outside the gas that is guided to the valve chamber 17g of the spool 17 through the bypass 12 when the valve is open.

The gas venting device 16 configured in this manner includes a valve body 22.
Pneumatic retaining mechanisms are provided for respectively retaining the open and closed states.

That is, the piston 20 has a small hole 20a that communicates between the head side chamber 23 and the rod side chamber 24 on both upper and lower sides thereof, and a hole 2 that communicates the circumferential surface of the piston 20 with the head side chamber 23.
0b is provided. In this case, for example, piston 2
When the diameter of 0 is 30, the small holes 20m are 2 to 3 m in diameter, and there are 1 to several holes, and the holes 20b are 2 to 3 fi in diameter, and there are 3 to 4 holes, and the total cross-sectional area of the holes 20b is was made to be somewhat larger than the total cross-sectional area of the small holes 20&. Also, spool 1
7 has a head side chamber 23 in the valve open state shown in the figure.
A port 25 that communicates between the rod side chamber 24 and the outside, a port 26 that communicates between the rod side chamber 24 and the outside, and a portion without a hole on the outer periphery of the piston 20, that is, the piston 2 where the hole 20b is not open.
A port 27 and an annular shape 428 are provided that communicate a part of the outer peripheral surface of the spool 17 with the outside of the spool 17. When the valve body 22 is closed, the piston 20 rises, so that the hole 20b communicates with the port 27, and the port 27 and the head side chamber 23 communicate with each other. In disgust,
In the piping connecting the port 25 and the air source 29, there is a switching valve 30 equipped with solenoids 5QL-A and 5QL-B.
26.27 and air source 2
A switching valve 31 equipped with a solenoid 5QL-0 is disposed in the pipe connecting the valve 9 and the valve 9. 32 is a reducing valve that applies a reduced constant pressure to the circuit. With this configuration, when 5'P is open, solenoid 5QL-A is activated.

When 5QL-C is de-energized and solenoid 5QL-B is energized, air enters the head side chamber 23 from the port 26, and air in the rod side chamber 24 exits to the atmosphere from the port 25, so the valve stem 21 rises. It also holds the valve in the closed position.
Solenoid 5QL-A, 5QL- when the valve is closed
When C is energized and solenoid 5QL-B is de-energized, air enters the head side chamber 23 from port 25.27,
Since the air in the rod side chamber 24 exits into the atmosphere from the port 2B, the valve shaft 21 is lowered and held at the valve open position.

The operation of the mold degassing device configured as described above will be explained. As shown in FIG. 3, when the molds 1 and 2 are clamped and the molten metal is injected into the inlet of the injection sleeve (not shown) and the plunger of the injection cylinder is moved forward, the bath water 7 flows between the fixed sleeve part 5 and the gate. 6 and then injected into the cavity 4 and filled. At this time, the piston 20 is descending and the valve body 2
2 and the valve seat 176 are open, the gas in the cavity 4 enters the valve chamber 17g from the cavity 4 through the vent/410, the bypass 12 and the valve opening, and enters the valve chamber 17g through the exhaust port 1.
It is ejected from 7F. At this time, solenoids 5QL-A and 5QL-C are energized by the valve open command signal, and solenoid 5QL-B is demagnetized, so the switching valves 30 and 31 are switched and the air is turned off. 25.
Air enters the head side chamber 23 from 27 and exits from the port 26 from the rod side chamber 24, but the discharge resistance of the rod side chamber 24 is much smaller than the small hole 2oaO pipe resistance, and the pressure in the head side chamber 23 is lower than the rod side chamber. 24 is sufficiently high, the piston 20 moves until its lower end surface contacts the valve guide 19, opening the space between the outer circumferential upper surface of the valve body 22 and the bypass 12, causing the valve to open. Since the state is maintained by air pressure, the valve body 22 will not close. In this state, when the solenoid 5QL-C is first demagnetized, air also flows from the port 26 to the rod side 24, and the pressure in the compartments 23 and 24 becomes the same, but the valve open position is maintained due to the difference in the pressure receiving area of the piston 20. do. Next, solenoid 5QL
- When A is demagnetized, air pressure flows from the rod side chamber 24 to the head side chamber 23 through the small hole 20m, passes through the gap between the piston 20 and the inner surface of the spool 17, and the annular groove 28, and is discharged from the port 27. However, at this time, the exhaust resistance is much smaller than the inflow resistance, so the pressure in the compartments 23 and 24 is still maintained at the same level, and the open state of the valve is maintained due to the difference in the pressure receiving area of the piston 20. At this time, the air in the rod side chamber 24 acts on the lower surface of the piston 20 as a force to move the piston 20 in the valve closing direction.

After the cavity 4 is filled with the molten metal 7, the molten metal 7 rises in the gas vent groove 10 and spills into the recessed portion of the lower surface of the valve body 22. At this time, the impact applied to the valve body 22 causes the valve body 22 to bounce upward because the mass of the bath water T is much larger than the mass of the gas and has a large inertia. As a result, the hole 20b of the piston 20 communicates with the port 27 and the head side chamber 23
The air inside is discharged from the port 27, and the air pressure acts auxiliary together with the inertia force of the molten metal 7, and the piston 20 moves upward, so the valve body 22 closes the bypass 12 and opens the gas vent groove 10 and the bypass. 12 and the valve chamber 17g. Therefore, the outflow of the molten metal 1 is stopped at the position of the valve body 22. At this time, since the pipe resistance of the hole 20b is much smaller than the pipe resistance of the small hole 20a, the pressure inside the head side chamber 23 is much smaller than the pressure inside the rod side chamber 24, and the piston 20 moves toward the head side chamber 23. The valve is forced to close not only by the force of the hemorrhoid γ but also by its own force and maintains this valve closed state.

In this case, even if the bath water 7 mixes with gas in the gas vent path 9 or the gas vent groove 10 and hits the valve body 22 discontinuously, the first collision of the molten metal 7 causes the valve to open. The body 22 is thrown up, and then the exhaust passage is reliably closed by the action of air pressure even without the upward pressing force of the molten metal 7.

In this way, the valve body 22 connects to the gas vent groove 10 and the bypass 1.
When Raku$7 is pressurized and cooled for a predetermined period of time with both 2 and 2 closed, the entire gas venting device 16 is raised by the cylinder 14 as shown in FIG.
After separating the valve body 22 from the solidified metal 33 shown in FIG.
A movable mold is opened to extrude the product through the product extrusion device 8. In addition, when the entire degassing device 1t16 is raised in the cylinder 14, the upward movement of the valve body 22 is hindered by the resistance between the valve body 22 and the solidified metal 33, and the rise of the spool 17 is delayed. Thus, the valve open position is maintained by the action of the air pressure. FIG. 4 shows that the valve body 22 is then closed by switching the switching valves 30, 31.

In the embodiment described based on FIG. 2, the valve body 2
2, the fluid pressure of air is applied to the head side chamber 23 of the piston 2o and the central port 27 to communicate the rod side chamber 24 of the piston 20 with the atmosphere, and the valve body 2 is opened.
2, when closing the head side chamber 23 and the port 2 in the center.
7 is opened to the atmosphere, fluid pressure is applied to the lot side chamber 24, and when the valve body 22 is open, the valve is kept open, and the inertia of the bath water is applied to the valve body 22 during injection. Once the valve body 22 has been closed by force, in order to maintain the valve closed state (in the holding state), fluid pressure is applied to the head side chamber 23 and the rod side chamber 24, Although the port 27 is shown to be open to the atmosphere, other patterns with other switching valves, fluid pressure circuits, and other operating conditions may be used.

For example, when opening the valve body 22, fluid pressure is applied to all of the head side chamber 23, rod side chamber 24, and port 21,
The rod side chamber 24 and the port 27 may be closed. In these cases, the force acting on the head side chamber 23 (pressure X surface 8t) is larger than the force acting on the rod side chamber 24, so the valve body 22 opens. When fluid pressure is applied to the head side chamber 23 to close the rod side chamber 24 and the port 27, and when fluid pressure is applied to the head side chamber 23, the fluid in the rod side chamber 24 flows into the small hole 20a provided in the piston 20.
The piston 20 may be moved in the valve opening direction by moving through the head side chamber 23.

In addition, when closing the valve body 22, 9, which is different from the above,
The head side chamber 23 may be opened to the atmosphere, fluid pressure may be applied to the rod side chamber 24, and the port 27 may be closed. That is, by applying fluid pressure to the rod side chamber 24 and opening the head side chamber 23 to the atmosphere, the port 27 may be opened to the atmosphere or closed.

In the case where the valve body 22 is kept in the holding state as described above, in the above embodiment, the head side chamber 23 and the lot side chamber 24 are
When fluid pressure is applied to the head side chamber 23 and the port 27 is opened to the atmosphere and the valve is open, the force acting on the head side chamber 23 is transferred to the rod side chamber 2.
4, and in the valve closed state where the valve body 22 is once closed by the action of the inertial force of the bath water, the fluid in the head side chamber 23 passes through the hole 20b and the port 21 with which the hole 20b communicates. The valve is kept in a closed state by the force of the fluid pressure acting on the rod side chamber, which is constantly released to the outside and combined with the action of pipe resistance due to the small hole 20a. It is also possible to apply fluid pressure to the rod side chamber 24 and open the port 27 to the atmosphere. In this case, when the head side chamber 23 is in the closed state and fluid pressure is applied to the lot gA11 chamber 24 with the valve open, the fluid in the rod side chamber 24 will flow into the head side chamber 23 through the small hole 20a. The pressures in the side chamber 23 and the rod side chamber 24 become the same, and the force acting on the head side chamber 23 becomes greater than the force acting on the rod side chamber 24 based on the difference in area between the head 0III chamber 23 and the rod side chamber, and as a result. As a result, the piston 20 continues to be pushed in the valve opening direction and continues to maintain the valve open state.

FIG. 5 is a longitudinal cross-sectional view of the main parts of another embodiment of the present invention corresponding to FIG. 2, and members having the same configuration as those shown in FIG. The explanation will be omitted. In this embodiment, the piston 20A has the small hole 20 in the previous embodiment.
No field or hole 20b is provided, and the central port 2
At a location corresponding to 7, an annular ring 1117h having the same width as the piston 20A is provided. When the valve shown in the figure is open, the annular groove 17h communicates with the head side chamber 23, and the ports 25 and 27 communicate with each other. When the valve is closed, the annular groove 17h communicates with the rod side chamber 24, and the ports 26 and 27 communicate with each other. It is structured so that it communicates with 27.

Furthermore, a switching valve 34 is provided in the ports 25 and 26 to selectively connect one of these to the air source 29, and also connects the central port 27 and the air source 29. A switch M'35 is provided in the piping.

By doing so, when solenoid 5QL-D is energized while solenoid 5QL-F is de-energized, valve body 22 closes, and when solenoid 5QL-E is energized, valve body 22 opens. After opening the valve, when solenoid 5QL-F is energized and then solenoid 5QL-E is deenergized, port 27 is connected to head side chamber 2.
3, so air flows from port 27 to head side chamber 2.
3. It flows out into the atmosphere through the switching valve 34. At this time, since almost no air flows from the rod side chamber 24 through the switching valve 34, the pressure generated by the pipe resistance of the exhaust path of the head side chamber 23 acts on the upper surface of the piston 20A, and the valve is maintained in the open state. Next, when the inertia force of the bath water 7 acts on the lower end surface of the valve body 22 and the piston 20A moves upward by more than a certain value, the piston 20A closes communication between the bow 27 and the head side chamber 23 on its outer peripheral surface. , since the port 27 is communicated with the rod side chamber 24, the switching valve 3 is connected from the rod side chamber 24.
4, the valve is kept closed due to the resistance in the pipeline.

6 to 9 are longitudinal cross-sectional views of the spool head showing other embodiments of the present invention, and in each figure, the second
Components with the same reference numerals as those in the figures have the same configurations, so their explanations will be omitted. First, in the case shown in Figure 6,
A compression coil spring 40 that is located between the piston 20 and the valve guide 19 and urges the piston 20 toward the head side chamber 23 side.
However, the rod side chamber 24 is interposed so that air, gas, and air are always input through the port 25 and exhausted through the port 27. Therefore, when the rising force due to the inertia of the bath water 7 is not acting on the piston 20,
The air pressure in the head side chamber 23 is lowered against the elastic force of the compression coil spring 40, and the piston 20 closes the central port 27 as shown in the figure, so that the piston 20 maintains the lowered valve open position. As mentioned above, when the bath water γ is filled and a rising force acts on the piston 20, this and the elastic force of the compression coil spring 40 temporarily overcome the air pressure in the head side chamber 23, causing the piston 20 to rise. Since the hole 20b and the port 27 communicate with each other, the air in the head side chamber 23 is then discharged from the port 2T via the hole 20b, and the piston 20 remains raised to maintain the valve closed state.

Next, in the one shown in FIG. 7, a compression coil spring 41 that is located between the piston 20 and the upper plate of the spool 17 and biases the piston 20 toward the rod side chamber 24 is connected to the head side chamber 24.
In addition, the air is switched so that it always enters through port 26 and is exhausted from port 27. The hole 20b opens into the rod side chamber 24. Therefore, when the rising force due to the inertia of the molten metal 7 is not acting on the piston 20, the piston 20 is lowered by the elastic force of the compression coil spring 41, and the hole 20b and the central port 2T are in communication, so that the rod Air in the side chamber 24 passes through the hole 20b and is discharged from the port 27, and the piston 20 remains in the lowered state to maintain the valve open state. When MM7 is filled and a rising force acts on the piston 20, this and the air pressure in the rod side chamber 24 overcome the elastic force of the compression coil spring 41, causing the piston 20 to rise and close the port 27, so that the rod side chamber 240 Strong air pressure causes the piston 20 to rise and move toward X to maintain the valve closed state.

Next, in the case shown in FIG. 8, air is always switched so that it enters through ports 25 and 26 and exits through port 27. Therefore, piston 2QKfa hot water 7
When the rising force due to the inertial force of While 20 is lowered, 9 maintains the valve open state. When the bath water 7 is filled and a rising force acts on the piston 20, the air pressure between this and the rod side chamber 24 overcomes the air pressure in the head side chamber 23, causing the piston 20 to rise and the hole 20b and port 27 to be connected. As a result, the air pressure in the head side chamber 23 decreases, and the piston 20 remains raised to maintain the valve open state.

Furthermore, in the one shown in FIG. 9, an annular groove 42 is formed at the opening of the hole 20b to the port 27, and a plurality of vertical holes are provided in the hole 20b.

By doing this, the resistance to the air flow is small 9, and the piston 20 can be moved up and down and held smoothly. Note that this embodiment can be implemented in common to each of the embodiments described above.

In any case, in the present invention, when the valve body 22 is open, the valve continues to be held in the open state, and after the inertia force of the molten metal acts on the valve body during injection and the valve body closes, the valve body 22 is opened in the head side chamber of the piston. The structure of the piston part is such that the pressure is automatically released and the valve body maintains the valve closed state.

Here, each of the solenoids 5QL-A and 5QL-B
, 5QL-C control device will be explained. FIG. 10 is a schematic configuration diagram of a control device using a limit switch, a mold, and a gas venting device for the mold. In the figure, the structure of the mold and the mold gas venting device is the same as that shown in FIG. 3, so the same reference numerals are used and the explanation thereof will be omitted. The fixed mold 1 has a pouring spout 50 in the fixed spout 5.
The injection sleeve 50 having the diameter m is fitted and the bath water 7 is supplied into the injection sleeve 50 from the spout 50a. Reference numeral 51 denotes an injection cylinder provided concentrically with the injection sleeve 50, and a plunger tip 55, which is the head of a plunger 54, is connected via a coupling 53 to a piston rod 52 that moves forward and backward using hydraulic pressure. , is slidably fitted into the inner hole of the injection sleeve 50. Also 56
is the solenoid 5QL-A of the switching valve 27, 35.39.
, 5QL-B, 5QL-C and the power source 5T are electrically connected to each other, or an electrical command device consisting of a limit switch and a timer or a plurality of limit switches (only one is shown), and is connected to the coupling 52. The solenoids 5QL-A, 5QL-B, 5QL are activated at the predetermined timing by opposing the striker 58 fixed via the bracket 13 and extending in the axial direction of the injection cylinder 51, and by opposing the striker 58 at a predetermined location. −
The structure is arranged so that C is energized and de-energized.

Due to the structure as described above, the spout 50a
When the plunger tip 55 is advanced by the injection cylinder 51 by supplying the bath water 1 from the
5, and is injected and filled into the cavity T as described above. At this time, as the plunger 54 moves forward, the striker 58 also moves forward, and its predetermined location and the plurality of limit switches 56 sequentially face each other, so that the solenoids 5QL-A, 5QL-B, and 5QL-C are activated at the predetermined timing described above. The valve body 24 is energized and de-energized, and the valve body 24 is reliably closed by cooperation with the inertia force of the bath water 7 pushing up the valve body 24.

Then, one of the limit switches 56 is connected to the solenoid 5Q.
If the solenoid 5QL-C is connected to L-C so that the solenoid 5QL-C is energized when the bath water 7 passes through the gas vent groove 10, air flows into the rond side subchamber 32 and the bottom surface of the 7 langes 22 & Since the valve body 24 is pressurized, the valve body 24 can be closed only by air pressure without having to push up the valve body 24 with the inertia force of the bath water 7.

In addition, solenoids 5QL-A, 5QL-B, 5
The QL-C can also be energized or de-energized by another external signal before the start of injection. However, if the valve body 24 is to be closed by the anticipated operation during injection, please close the solenoid 5Q of the replacement tank 39.
Excite L-C during injection.

FIG. 11 is a block diagram of a control device using a magnetic scale, and members given the same reference numerals as those in FIG. 10 have the same configurations, so explanations thereof will be omitted. In the figure, a magnetic scale 59 extending in the axial direction of the injection cylinder 51 is fixed to a coupling 53 that connects the piston rod 52 and the plunger 54, and a magnetic sensor 60 is disposed near the magnetic scale 59. There are stones. When the magnetic scale 59 moves together with the plunger 54, a pulse signal is extracted from the magnetic sensor 60, and this pulse signal is sent to and input to a comparator 61. On the other hand, a timer (not shown) determines at which position of the stroke of the plunger 54 the switching valve 27.35
．． A condition setting device 62 is provided for setting whether or not 39 is opened, and a signal from this is also input to a comparator 61. The comparator 61 is the solenoid 5QL-A of each of the switching valves 27, 35, and 39.

It is electrically connected to 5QL-B and 5QL-C, and when both inputs are compared by a comparator 61 and they match, or when the timer finishes counting a predetermined time, a signal is emitted, and each solenoid is configured to be energized and de-energized at the predetermined timing mentioned above. In particular, the solenoid 5 is
When QL-C is energized, the valve body 24 is closed. 63 is a monitor or recording device, and 64 is an operation panel for manually opening and closing the switching valves 27, 35, and 39, respectively.

Due to this configuration, when the plunger 54 moves forward to inject and fill the bath water 7, the magnetic scale 59 integrated therewith moves forward, and pulse signals are extracted from the magnetic sensor 60 and compared. input to the device 61. On the other hand, since the setting signal from the condition setting device 62 is also input to the comparator 61, when these two signals match, a signal is generated, and the solenoid 5QL-C is energized with the above-described predetermined timing.
Since it is de-energized, the valve body 24 due to the inertial force of the pregnancy bath 7
The valve body 24 is reliably closed in cooperation with the push-up of the valve 24 or based only on an electric valve opening command signal.

In this case as well, if the condition setting device 62 is set so that the solenoid 5QL-C is energized when the molten metal T passes through the degassing tank 10, the air flows into the rod side secondary chamber 3.
Since the air flows into the air and pressurizes the lower surface of the flange 22&, the valve body 24tl- can be closed only by air pressure without pushing up the valve body 24 with the inertia force of the bath water 7.

In addition, when closing the valve body 24 using an electric valve open command signal during injection, the gas in the cavity 4 is sufficiently vented by properly typing the fP open command signal, but the molten metal is not vented. It is necessary to prevent it from entering the device 16.

In addition, as mentioned above, the valve body 2 which can be closed by the inertia force of the molten metal
4 is closed by an electrical command during injection when the flow of the bath water 7 is normal, and if the electrical command is not typed properly, the molten metal T will close before the valve body 24 is closed by the command. When the valve body reaches the point where it enters the valve device, the operation of the valve device becomes uncertain, but even in that case, the inertial force of the bath water 7 causes the valve body 24 to close due to a delayed electrical signal during injection. Since the valve body 24 closes, the closing operation of the valve body 24 is always performed reliably, is safe, and can sufficiently respond to long-term continuous operation.

In addition, as a structure for closing the valve body 24 without pushing up the valve body 24 due to the inertial force of the bath water 7, there is a detection method that detects passage of the molten metal 7 to the entrance of the gas vent @ groove 10 serving as the molten metal passage. A means is provided and the solenoid S is activated by the bath water detection signal.
It is also possible to close the valve body 24 by energizing QL-C. In this case, the molten metal detection means includes, for example, a pair of I
! Alternatively, an ultrasonic transmitter and an ultrasonic receiver may be provided to short-circuit the bath 1 by passing the molten metal 7 therethrough.
The passing of the molten metal 7 can be detected by attenuating the transmitted ultrasonic waves by the passage of the molten metal 7, and the valve body 24 can be closed. Groove 1 is made of non-magnetic material as a means of detecting molten metal.
A primary coil and a secondary coil with the 0 side demagnetized are provided to block the magnetic flux when the M hot water 7 passes.By changing the voltage and detecting the passage of the bath water 7, the valve body 24 is closed. Alternatively, a high-power current may be supplied to the senna coil provided in the gas vent groove 10, and the impedance of the senna coil may be changed by the passage of the bath water 7, and passage of the bath water 7 may be detected. may be closed.

In the above embodiment, the gas exhaust hole 17f provided in the spool 17 is exposed to the atmosphere. Leave the inside in a vacuum state and remove the valve body 2.
4 can also be closed. In addition, compressed air is generally used as the fluid used to open, close, and hold the valve body, but when hydraulic oil is used as this fluid, a hydraulic pump is used as the fluid supply source, and each switching valve The F-GIST port must be connected to the oil tank by piping. Further, in each embodiment, an example was shown in which the present invention was applied to a mold of a die-casting machine, but the invention can be similarly applied to a mold of an injection molding machine.

〔Effect of the invention〕

As is clear from the above description, in the mold degassing device according to the present invention, a piston that fits into the spool inner hole is fixed to the end of the valve body opposite to the valve body, and the piston is connected to the valve body side chamber of the piston. A counter valve (two ports each opening to the T-side chamber, and a central port that is blocked by the piston's outer peripheral surface or communicates with the piston's valve body side chamber or the counter-valve body's Jllll chamber) are provided. By connecting each of these ports and the pressure fluid source with piping that has a switching valve, when the valve body is open during degassing, the valve is kept open due to the pressure difference between the head side chamber and the rod side chamber. During injection, the inertial force of the bath acts on the valve body and after the valve body closes, the pressure in the head side chamber automatically escapes and the valve body maintains the valve closed state.
Even when the valve is repeatedly opened and closed, there is no risk of the holding part being worn out unlike with conventional holding using balls, etc., and the holding force in both the open and closed positions can be reliably maintained for a long period of time, ensuring durability and reliability. is significantly improved. In addition, the valve operates reliably at all times,
Since gas is reliably discharged during injection, a high-quality, high-strength injection product without voids can be obtained reliably and easily. Furthermore, compared to mechanically holding the valve in the open position, the number of parts is reduced9, maintenance is easier, and the force for holding the valve in the open position can be adjusted only by adjusting the pressure reducing valve. , adjustment becomes easier.

[Brief explanation of drawings]

1 to 9 show an embodiment of the mold degassing device according to the present invention, FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is a longitudinal sectional view of the main parts, a pneumatic circuit diagram, and Fig. 3 is a partially cutaway front view of the degassing device and the mold in which it is installed, Fig. 4 is a longitudinal cross-sectional view showing the degassing device separated from the mold, corresponding to Fig. 1; FIG. 5 is a vertical sectional view of essential parts and a pneumatic circuit diagram showing another embodiment of the present invention corresponding to FIG. 2, and FIGS. 6 to 9 are spool heads showing other embodiments of the present invention, respectively. Fig. 10 is a schematic configuration diagram of a switching valve control device using a cut-out switch, a mold and a gas venting device for the mold, and Fig. 11 is a switching valve control device using a magnetic scale. FIG. 2 is a schematic configuration diagram of a mold and a gas venting device for the mold. 1...Fixed mold, 2...Movable mold, 4...
Cavity, 7...Bath water, 11...Spool hole, 16...Gas venting device, 17...Spool,
1Td...inner hole, 1Te...valve seat, 17f...
・・Discharge port, 19・・・・Valve guide, 20.2OA・
・ ・ ・Piston, 21 ・ ・Valve stem, 22...
...Valve body, 23...Head side chamber, 24...Rod side chamber, 26, 27.28...Port, 29...
・Air source, 30, 31° 34.35...Switching valve, 4
0.41...Compression coil spring, 42...Annular groove. Applicant for permission of condolence Ube Industries Co., Ltd. Agent Seiji Yamakawa (1312 people) Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A spool that is formed into a bottomed cylindrical shape with a gas outlet on the wall and whose open end is joined to the spool hole of the mold, and a valve rod that is supported in the inner hole of the spool through a valve guide so that it can move forward and backward. The gas in the mold cavity is discharged from the discharge port through the inner hole of the spool that engages with the spool hole, and the valve body is disposed on the valve rod by moving the valve rod in the axial direction. In a gas venting device for a mold that closes a valve seat at the opening end of the spool, a piston that slidably fits into the inner hole of the spool is fixed to the end of the valve stem opposite to the valve body. The two ports that open to the valve body side chamber and the anti-valve body side chamber, respectively, and the central port that is blocked by the outer peripheral surface of the piston or communicates with the valve body side chamber or the anti-valve body side chamber of the piston are connected to the spool. A degassing device for a mold, characterized in that it is provided on an outer wall, and each of these ports and a pressure fluid source are connected by piping having a switching valve.