JPH0156862B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for spraying a mold release agent onto a mold using a mold gas exhaust device, which is used in a casting molding device such as a die casting machine. It is related to.

[Prior Art] Die casting has been widely used as a method for manufacturing precision products in large quantities, but it has sometimes been unsuitable for products where the integrity of the product is important, with no cavities inside the product.

The reason for this is that since the cavity is filled with molten metal at high speed and high pressure, the gas in the cavity may not be able to escape sufficiently and may mix with the molten metal and remain in the product as cavities.

In order to eliminate such inconveniences, the present inventors have made it possible to reliably and easily remove a large amount of gas without being restricted by the cast product or mold, eliminate gas entrainment, and obtain a sound die-cast product. We have developed a gas exhaust device for molds.

This device performs injection with the discharge path leading from the mold cavity to the outside of the mold opened by the action of a valve, and when the gas with a small mass in the cavity has been exhausted through the gas discharge path, By applying the inertial force of the large mass of the molten material to be injected that has advanced from inside the cavity directly to the valve, the valve is reliably and quickly moved and closed, directly cutting off the gas discharge path and removing this gas. It is possible to prevent the melt to be injected from flowing out from the discharge path, and to ensure that gas in the mold can be vented easily during injection.

This mold gas exhaust device has a valve support member such as a spool that slidably holds a valve inside, and the valve support member is provided with a discharge hole for gas exhausted to the outside through the valve device. When the valve device is open, the gas inside the cavity is discharged to the outside through the valve device.

On the other hand, in order to make it easier for the solidified molten metal cast in the mold cavity and gas exhaust passage to separate from the mold and the valve head of the mold gas exhaust device, and to make it easier to take out the mold, A mold release agent containing a lubricant is sprayed onto the valve head of the gas exhaust device.

In this case, open the mold, remove the valve of the mold gas exhaust device and the valve support member slightly from the mold, and with the valve device open, attach the mold and the valve head of the mold gas exhaust device, etc. A mold release agent was being sprayed.

Therefore, the mold release agent may adhere to the sliding surface of the valve in the mold gas exhaust device or get into the sliding surface between the valve and the valve support member, making it difficult to use this device for a long time. If the mold release agent adhered to the sliding surfaces of the valve or entered between the sliding surfaces, the mold release agent would solidify, making the valve less likely to move or becoming inoperable.

[Problems to be Solved by the Invention] In the mold release agent spraying method for a mold gas exhaust device, when the mold release agent is applied to the mold or the valve head of the mold gas exhaust device by spraying, the mold release agent is If the agent passes around the open valve head and enters the valve device and adheres to the sliding surfaces of the valve or enters between the sliding surfaces,
This hinders the opening and closing operations of the valve, hinders subsequent use of the valve device, and requires time and effort for repairs.

[Means for Solving the Problems] In the present invention, in order to solve the problems in the conventional method as described above, a gas exhaust groove is provided in the gas vent groove communicating with the mold cavity of the casting machine. For molds using a valve device that is equipped with an on-off valve, a valve body that can be opened and closed by sliding inside the on-off valve, and a discharge hole for gas discharged to the outside through the on-off valve on the valve support member. In the gas exhaust device, when spraying a mold release agent to an open on-off valve, simultaneously supplying a fluid such as compressed air for cleaning from the outside to the inside of the on-off valve through a hole provided in the valve support member, Fluid is sprayed onto the sliding surface of the valve inside the on-off valve.

[Function] As described above, in the present invention, when the mold release agent is being sprayed and supplied to the open on-off valve, the release agent is sprayed from the outside of the on-off valve to the inside through the gas exhaust hole provided in the valve support member. At the same time, a cleaning fluid is blown in to blow away the mold release agent that is about to adhere to the sliding part of the valve inside the on-off valve and the mold release agent that has adhered to it. Then, when the valve slides and closes, the mold release agent is prevented from entering between the valve and the support member.

[Example] Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

1 and 2 illustrate one embodiment of an apparatus for carrying out the method of the present invention, in which the reference numeral 1 denotes a fixed mold, 2 a movable mold, and 1a and 2a a movable mold. These are half-split seats fitted into the dividing surfaces of the fixed mold and movable mold. Here, the seats 1a and 2a are part of a fixed mold 1 and a movable mold 2, respectively. A degassing device 3 is provided at the dividing plane between the fixed mold 1 and the movable mold 2 and at an extended position thereof.

On the other hand, an exhaust passage is formed from the periphery of the cavity 4 to the lower part of the gas venting device 3 via a gas venting groove 6 from a gas venting path 5 formed on the dividing surface of the mold.

And a gas venting device 3 which also blows gas.
In this case, the valve 7 is provided so that the lower surface of the valve head 7a is substantially perpendicular to the gas vent groove 6, and the valve head 7 is detoured from the middle of the gas vent groove 6 in the lateral direction of the valve head 7a.
A gas exhaust passage 8 consisting of a bypass extending to the upper side of a is provided. 8 is a hot water pool part.

The valve 7 slides in the axial direction of the spool 9 within the spool 9, which is a valve support member, and when the valve 7 moves upward in FIG. Valve head 7 on seat 10
a contact, and communication between the passage 8 and the valve chamber 11 in the spool 9 is closed.

A valve chamber 11 formed around the valve stem 7b is continuous above the valve head 7a, and an outlet 12 for discharging gas is formed in the valve chamber 11.

A spring receiver 13 is fixed to the upper end of the valve stem 7b in the middle of the spool 9.
is slidably fitted in a chamber 14 formed at the upper end of the spool 9, similar to the piston, and includes a spring receiver 13 and a guide member for the valve rod 7b provided on the lower surface of the chamber 14, that is, in the middle of the spool 9. A compression spring 15 is elastically mounted between the valve 9b and the upper surface of the valve 9b, and a force is always applied to the valve 7 in the closing direction.

A through hole 9a is formed in the guide member 9b in the middle of the spool 9 in a state perpendicular to the valve stem 7b, and a steel ball 17 is inserted into the through hole 9a while being pressed by a compression spring 16. This steel ball 17 is in contact with a small diameter portion 7c formed in the middle of the valve stem 7b. Further, the pressing force of the compression spring 16 can be adjusted by a push screw 18.

The steel ball 17 stops the valve 7 which is about to be moved upward by the compression spring 15, and the pressing force of the compression spring 16 is large enough to overcome the elastic force of the compression spring 15.

Projections 9c, 9c are provided on both sides of the upper end of the spool 9, forming a T-shape.
9a so as to be slidable in a direction perpendicular to the axis of the valve 7. This block 19 is fixed to the lower end of a piston rod 21a of a cylinder 21 fixed to a support frame 20 fixed to the fixed mold 1 side via a block 19c integrated therewith.

19d is a bolt for connecting blocks 19 and 19c.

On the other hand, as shown in FIG. 1, a groove 19b is formed across the upper end of the block 19, and a lever 22 is fitted into this groove 19b so as to be able to move up and down. The length of the lever 22 may be equal to the width of the block 19 when viewed from the front;
Make the length so that it protrudes beyond the end face of the.

The lever 22 is fixed to the upper end of a pin 23 that is fitted into the center of the block 19 so as to be able to move up and down.
The lower end of the pin 23 faces into the upper chamber of the chamber 14, and faces the spring receiver 13 fixed to the upper end of the valve rod 7b.

A rotary lever 25 is rotatably supported on the front surface of the block 19 via a thumbscrew 24, and when the rotary lever 25 is in the vertical position, its lower end touches the front surface of the upper end on the spool 9 side. ing. As a result, when the rotating lever 25 is in the vertical position, the spool 9 cannot escape from the T-slot 19a, and when the rotating lever 25 is in the horizontal position,
With the spool 9 and the valve 7 moved above the molds 1 and 2, the spool 9 can be pulled out in the horizontal direction.

Further, a compression spring 26 is elastically loaded between both ends of the lever 22 and the block 19.
2 is always pushed upward to prevent the pin 23 from coming into contact with the spring receiver 13 when the lever 22 is raised.

On the other hand, a pair of left and right stoppers 27, 27 are provided in the middle of the support frame 20 so as to project to a position where they can come into contact with the lever 22.

Further, the block 19c has a protrusion 19f in a part thereof, and this protrusion 19f is slidably fitted into a guide rod 28 provided on the support frame 20 side, so that the spool 9 can be inserted into the guide rod 28 as described later. Provide guidance when going up and down.

The block 19 to which the upper end of the spool 9 is connected has a backing plate 2 on the side opposite to the rotating lever 25.
9 is fixed at its upper end with a bolt 30. The lower end of the backing plate 29 extends toward the spool 9, and a proximity sensor 31 is attached to the backing plate 29 at the connecting portion between the block 19 and the spool 9. Proximity sensor 31 detects the position of spring receiver 13 and therefore valve 7 . Then, it is possible to detect whether the valve 7 is in a closed state or an open state, and the detection signal is guided to the control device side via the wiring of the proximity switch 31.

A compressed air source 34 is also provided at the lower end of the backing plate 29.
A connecting hole 29a for connecting to the vacuum generator 35 is formed, and this connecting hole 29a communicates with a through hole 14a that is continuous with the chamber 14 formed at the upper end of the spool 9. And the through hole 14a
An O-ring 32 is attached to the edge of the connecting hole 29a at a position in contact with the edge of the connecting hole 29a, so that the connecting portion between the two can be kept airtight.

Note that the upper chamber of the spring receiver 13 is the spool 9.
It is connected to the outside air through a passage 19e between the block 19 and a passage 25a provided in the rotary lever 25.

A patch plate 29 as described above is provided, and the connection hole 29 is
An O-ring 3 is attached to the contact part of the spool 9 to a.
2, when cleaning the degassing device, the spool 9 can be pulled out from the T-slot 19a and only the spool 9 and the valve 7 can be easily removed. Therefore, the backing plate 29 remains as it is, and the proximity sensor 31 and its wiring and compressed air source 34
The side piping remains as it is on the block 19 side, and there is no need to attach or detach wiring or piping, making cleaning and maintenance operations extremely easy. Of course, when attaching spool 9 to block 19, attach spool 9 to T.
It can be installed extremely easily by simply pushing it into the groove 19a, pressing it against the backing plate 29, and locking it with the rotating lever 25.

One end of a pipe 33 is connected to the through hole 29a, and this pipe 33 is connected to a compressed air source 34 and a vacuum source 35, which is a vacuum generator.

Further, one end of a pipe 36 is connected to a part of the valve chamber 11 through the gas discharge outlet 12 or other hole, and this pipe 36 is also connected to a compressed air source 3.
4 and a vacuum source 35.

An electromagnetic switching valve 37 is connected between the piping 33 and the compressed air source 34, and an electromagnetic switching valve 38 is connected between the piping 33 and the vacuum source 35.

Moreover, between the piping 36 and the compressed air source 34,
The electromagnetic switching valve 39 also connects the piping 36 and the vacuum source 35.
An electromagnetic switching valve 40 is connected between the two.

Between the opened fixed mold 1 and the movable mold,
A conventionally known mold release agent coating device, an air spray device, etc. (not shown) are provided so as to be freely movable.

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

When the molding equipment starts operating, the mold and other parts are cooled down, and if normal injection operation is performed in this cooled state, the molten metal will cool down before it reaches every corner of the mold cavity, causing the metal to melt. Part of the product may remain in the mold.

During injection molding, low-speed injection is performed at the initial stage of injection, followed by high-speed injection, but at the beginning of molding, usually 2 to 5 test shots are performed using only low-speed injection to raise the temperature of the mold. I do.

In such a low-speed trial shot immediately after the start of operation, the inertia of the molten metal is weak, so even if the molten metal hits the valve head 7a, the valve 7 will not close, and there is a risk that the molten metal will enter the spool 9 side.

Therefore, at the start of operation, this degassing device is set in the mold, and only the electromagnetic switching valve 37 is switched manually or automatically, the compressed air source 34 and the chamber 14 are communicated, and compressed air is supplied. Then, air pressure is applied to the spring receiver 13 having a piston structure, and the valve 7 is moved against the pressing force of the steel ball 17.
can be forced to close by moving up.

If a structure is adopted in which the operation of closing the valve 7 using air pressure can be performed by remote control, inconvenience and danger to workers can be significantly reduced.

After performing several shots of warm-up operation as described above, the electromagnetic switching valve 37 is turned off, and then an injection operation using a combination of normal low-speed injection and high-speed injection is performed.

In this case, first, only the electromagnetic switching valve 38 is turned on, the vacuum source 35 and the chamber 14 are communicated, and the chamber 1
4. Vacuum the inside. By doing so, a downward force acts on the spring receiver 13 and the valve 7, so that when the spool 9 and the like are lowered by the action of the cylinder 21, the valve 7 will not be closed by the shock.

In this state, the cylinder 21 is operated to lower the spool 9 to a predetermined position and clamp the mold. At this time, the valve 7 is open, so from the cavity 4 to the gas vent path 5, the gas vent groove 6, the passage 8, and the valve chamber 1.
A passageway is formed that passes through the spool 1 and reaches the outside of the spool 9.

In this state, the electromagnetic switching valve 38 is turned off, only the electromagnetic switching valve 40 is turned on, and injection molding is performed while vacuum suctioning the gas in the valve chamber 11 before or during operation of the injection plunger (not shown). I do. In this way, the gas is forced out.

During injection, the molten metal filling the cavity 4 advances through the gas vent path 5 and the gas vent groove 6, but the residual gas in the cavity 4 passes through the passage 8 and the valve chamber 11 and flows toward the discharge port 12. heading to Note that since the gas has a small mass, the valve 7 will not close due to the action of the gas.

On the other hand, following the gas, the molten metal collides with the lower surface of the valve head 7a. At this time, the impact applied to the valve 7 is much larger than the impact applied to the valve 7 by the gas, as the mass of the molten metal is extremely large compared to the gas, and the inertia is large, causing the valve 7 to jump upward. As a result,
The restraining force of the steel ball 17 pressed by the compression spring 16 is released, the valve 7 faces upward, and the upward pulling force of the compression spring 15 is also applied, so that the upper surface of the valve head 7a is seated on the valve seat 10. Aisle 8
and the valve chamber 11 to prevent the outflow of molten metal from the valve 7.
Stop at the position.

At this time, even if the molten metal mixes with the gas in the gas vent path 5 and the gas vent groove 6, becomes a droplet, and hits the valve body discontinuously, the first collision of the molten metal causes the valve body to be blown away. Even if the upward pressure from the molten metal disappears when the gas comes, the valve 7 is given the habit of moving upward by the force of the compression spring 15, so the valve 7 will not block the exhaust passage. It will definitely be done.

Note that when the valve 7 moves upward, the valve head 7a becomes the valve seat 1.
Even when the valve 7 is seated in the position 0, there is a predetermined space between the spring receiver 13 at the upper end of the valve 7 and the lower surface of the pin 23, so the pin 23 contacts the spring receiver 13 and the valve 7 There is no inconvenience caused by pushing downward.

Injection is carried out in this manner, and when the casting operation is completed by pressurized cooling for a predetermined period of time with the valve 7 of the degassing device closed, the mold is opened, the cylinder 21 is operated, and the spool 9 to rise. With this upward movement, the solidified metal filling the cavity 4, gas vent path 5, gas vent groove 6, and passage 8 separates from the valve 7, and the molded product is moved by a product extrusion device (not shown). Remove from mold.

When the cylinder 21 is actuated and the entire spool 9 is pulled up, both ends of the lever 22 attached to the block 19 come into contact with a stopper 27 protruding from the support frame 20 side. The lever 22 moves downward in the groove 19b under the force of the compression spring 26, and as a result, the pin 23 descends and connects to the spring receiver 13 of the valve 7 at the limit of upward movement, which is connected to the compression spring. It overcomes the force of 15 and pushes downward.

As a result, the valve head 7a separates from the valve seat 10 and the valve is completely opened.

As the valve 7 descends, the steel ball 17 again fits into the small diameter portion 7c formed in the middle of the valve stem 7b, keeping the valve 7 open.

In this state, a release agent applicator (not shown) is inserted between the open molds 1 and 2, and applied to the fixed mold 1, valve head 7a, etc., for example, in front of the mold or diagonally above the mold. Spray and apply the mold release agent. At this time, only the electromagnetic switching valve 39 is turned on, and compressed air is supplied to the valve chamber 11.
lead to the side. The supply of compressed air should be completely overlapping with the spraying time of the mold release agent, or almost overlapping with the spraying time of the mold release agent, or should be supplied until a little after the spraying of the mold release agent is finished, and the air should be open above the mold. Clean the area around the valve 7, and prevent mold release agent from adhering to the sliding surface of the valve rod 7b. At this time, since the valve 7 is in an open state, the inside of the valve chamber 11 and the area around the valve head 7a and valve seat 10 are cleaned by the compressed air, and even if there is metal powder, it is sufficiently removed. . Therefore, the valve 7 can be completely closed the next time the valve is closed. Of course, valve stem 7b
The mold release agent that has adhered around the valve rod 7b and the mold release agent that has tried to enter between the valve stem 7b and the guide member 9b is blown away by air compression and becomes clean, so that the mold release agent hardens and is removed from the valve 7. Movement is never disturbed and the valve always operates smoothly.

Next, in the same way as described above, with the electromagnetic switching valve 38 turned on, the cylinder 21 is operated to lower the spool 9 and the valve 7 at the same time, the fixed mold 1 is set, the mold is clamped, and the next step is performed. Perform the casting operation.

Although the embodiment shown in FIG. 1 shows an example in which the gas discharge port 12 and the pipe 36 are provided separately, they can also be combined into one as shown in FIG. 3.

In the example shown in FIG. 3, a tee 41 is attached to the gas discharge port 12, and a lid 43 that opens only outwards around the pin 42 is attached to the other end of the tee 41 in the horizontal direction. Install freely,
A pipe 36 was connected to the upper opening 41a of the tee 41, and the pipe 36 was connected to a compressed air source 34 and a vacuum generator 35 via an electromagnetic switching valve 44. The compressed air source 34 and the vacuum generator 35 communicate with the pipe 33 via an electromagnetic switching valve 45, and also communicate with the through hole 29a. Then, the compressed air source 34 is connected to the piping 3.
When connecting the compressed air source 34 to the piping 33, the solenoid 44a is energized; when the vacuum generator 35 is connected to the piping 36, the solenoid 44b is energized; when the compressed air source 34 is connected to the piping 33, the solenoid 45a is energized; When the vacuum generator 35 is connected to the pipe 33, the solenoid 45b is excited. The electromagnetic switching valves 44 and 45 were four-way switching valves, and piping was connected to the illustrated A, P, and T ports, respectively, but the B port was blocked.

In this embodiment, the valve can be opened/closed or maintained in the open/closed state using a compressed air source for cleaning and a vacuum source for degassing by vacuum suction.

In addition, if you wish to clean or maintain the entire degassing device 3, loosen the thumbscrew 24, rotate the rotating lever 25 approximately 90 degrees, and position it from the vertical position to the horizontal position. The protruding portion 9c formed in the portion can be easily removed from the T-slot 19a, and the entire spool 9 can be removed extremely easily.

In addition, in this embodiment, the valve 7 and the lever 22
It is provided separately from the valve 7, and when the valve is closed, only the valve 7 can be operated.

Therefore, compared to the conventional valve 7 that is integrated with the lever 22, the mass is smaller, the inertia during operation is smaller, and the valve closes at an extremely fast speed when the molten metal collides with the valve body. Be responsive.

Note that when the valve 7 is set as shown in FIG. valve head 7a
The distance between the outer peripheral upper surface of the valve seat 10 and the valve seat 10 is set to be somewhat larger than the distance between the valve seat 10 and the outer peripheral upper surface of the valve seat 10.

On the other hand, if the position of the stopper 27 is selected, it can be set so that the stopper 27 and the lever 22 are in contact and the valve 7 can be lowered by more than the above stroke when the spool 9 is pulled up to the maximum extent.

When such a structure is adopted, a large distance can be provided between the valve head 7a and the valve seat 10, a large space can be secured when cleaning the valve, and metal powder etc. can be reliably removed. .

In the above embodiment, an example was shown in which a valve that automatically closes due to the inertia of the molten metal was used as the valve device for the degassing device, but this is not possible due to the electrical signal during casting. Other on-off valves, such as closing solenoid valves, can also be used.

Further, in the above embodiment, compressed air was used as the fluid for cleaning and blowing off the mold release agent, but gas containing lubricant may also be used, or both compressed air and lubricant may be used. may be sprayed separately.

[Effects of the Invention] In the present invention, as shown in the claims, when spraying a mold release agent onto a mold or the valve head of an open valve, the release agent is sprayed through a hole provided in a valve support member. By simultaneously supplying gas such as compressed air for cleaning to the inside of the valve, it is possible to sufficiently clean the valve and remove metal powder, etc., and also to prevent sliding of the valve, such as around the valve stem. The mold release agent that has adhered to the surface or is about to adhere can be blown away.
This can sufficiently prevent the mold release agent from hardening on the sliding surface of the valve or from entering between the valve and the valve support member that slidably holds the valve. . Therefore, the valve can be operated properly at all times, the gas in the cavity can be sufficiently discharged, and a cast product without cavities can be reliably and easily obtained.

[Brief explanation of drawings]

1 and 2 illustrate an embodiment of an apparatus for carrying out the method of the present invention, in which FIG. 1 is a longitudinal sectional view, FIG. 2 is a partially sectional front view, and FIG. 3 is a partially sectional front view.
The figure is a pneumatic circuit diagram showing another embodiment of the piping section. 1... Fixed mold, 2... Movable mold, 3... Gas venting device, 4... Cavity, 6... Gas venting groove, 7... Valve, 9... Spool, 10... Valve seat,
11... Valve chamber, 12... Gas discharge hole, 13... Spring receiver, 15, 16, 26... Compression spring, 17...
...Steel ball, 19...Block, 19a...
...T groove, 21...Cylinder, 22...Lever, 2
5... Rotating lever, 27... Stopper, 34...
Compressed air source, 35... Vacuum generator, 37-4
0, 44, 45...Solenoid switching valve.

Claims (1)

[Claims] 1. A gas discharge opening/closing valve is provided in the gas venting groove communicating with the mold cavity of the cast molding device, and as the opening/closing valve, a valve is provided inside so that it can be opened and closed by sliding, and gas is discharged to the outside through the opening/closing valve. In a mold gas exhaust device using a valve device in which a gas exhaust hole is provided in a valve support member, when spraying a mold release agent to an open on-off valve, the on-off valve is sprayed through the hole provided in the valve support member. A method of spraying a mold release agent onto a mold using a mold gas exhaust device that simultaneously supplies cleaning fluid from the outside to the inside.