JPH0238060B2 - KANAGATAYOGASUNUKISOCHINIOKERUBENBUNOSETSUCHIHOHO - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is used in a casting machine such as a die-casting machine, and is used as a gas vent for a mold to discharge a large amount of gas from a cavity of the mold. The present invention relates to a method for installing a valve part in an apparatus.

[Prior art]

Conventionally, die casting has been widely used as a method for manufacturing precision products in large quantities, but there are cases where die casting is not suitable for products where the integrity of the product without porosity is important.

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 sufficiently released 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 venting device for molds.

This device performs injection with the gas exhaust path leading from the mold cavity to the outside of the mold opened by the action of a valve, and the gas with a small mass in the cavity is exhausted through the gas exhaust path, and when the gas has finished being exhausted. Then, 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.
This device directly blocks the gas exhaust path and prevents the molten material to be injected from flowing out from the gas exhaust path, allowing gas to be removed from the mold reliably and easily during injection. be.

An example of a device adopting such a structure is shown in the first example.
Shown in Figure 2.

In the figure, what is indicated by code 1 is a fixed mold, 2
1 is a movable mold, and 1a and 2a are half-shaped seats fitted into the dividing surfaces of the fixed mold and the movable mold, respectively.
Here, seats 1a and 2a are respectively fixed mold 1 and
It is a part of the movable mold 2. A degassing device 3 is installed at the dividing surface of the fixed mold 1 and the movable mold 2 and at its extended position.
is provided.

On the other hand, the exhaust air reaches the lower part of the gas venting device 3, that is, the front part 11a of the valve chamber 11, which will be described later, from the periphery of the cavity 4 through the gas venting groove 6 from the gas venting path 5 formed on the dividing surface of the mold. A passage has been formed.

As the gas venting device 3, a seat type valve 7 is provided so that the lower surface of the valve head 7a is substantially perpendicular to the gas venting groove 6, and from the middle of the gas venting groove 6 to the lateral direction of the valve head 7a. A gas exhaust passage 8 is provided, which is a bypass that detours to the upper side of the valve head 7a, that is, to the side surface of the valve chamber 11 immediately in front of the valve seat 10, which will be described later. 8a 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 rear portion 11b of the valve chamber 11 in the spool 9 is closed. The valve chamber 11 has a front part 11a formed in a mold, a rear part 11b formed in a part separated from the mold, and a valve seat 10 formed between the front part 11a and the rear part 11b. are doing. And the front part 1 of the valve chamber 11
In 1a, the valve head 7a of the seat type valve 7
, the passage 8 which is a bypass is connected to the rear part 11 of the valve chamber 11.
The valve is slidably provided between the open position where the valve b communicates with the valve and the closed position where communication between the passage 8 and the rear part 11b of the valve chamber 11 is cut off. Before reaching the valve chamber 11, the valve 7 can be moved from the valve open position to the valve closed position by the inertial force of the molten metal advancing through the gas vent groove 6.

A rear part 11b of the valve chamber 11 formed around the valve stem 7b is continuous above the valve head 7a, and a discharge port 12 is formed in the rear part 11b of 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. Valve stem 7b
The spring receiver 13 at the rear end is a piston, and the piston and the chamber 14 form a piston cylinder device. The compression spring 15 is connected to the valve 7
This is a type of second holding device that holds the valve 7 in the valve-closed position after it is moved from the valve-open position to the valve-closed position by the initial inertia of the molten metal.

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 7b 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 is used to stop the valve 7 which is about to be moved upward from the valve open position to the valve closed position by the compression spring 15, which is a second holding device. It is large enough to overcome the force of the attack.

Here, the steel balls 17 and the like provided at the rear of the valve chamber 11 advance through the gas vent groove 6 before the molten metal that advances through the passage 8 reaches the valve chamber 11 during injection. A first holding device is formed to hold the valve 7 in the valve open position in such a manner that the valve 7 can be moved from the valve open position to the valve closed position by the inertial force of the molten metal. And the first holding device is the valve 7
is releasably installed at the valve opening position against the force of a second holding device consisting of a compression spring 15.

The piston cylinder device is provided so as to act as a valve opening device for moving the spring receiver 13, which is a piston, forward against the force of a second holding device made of a compression spring 15, and is also equipped with a steel ball 17, etc. By forcibly moving the piston 13 backwards against the force of the first retaining device, the valve 7 is released from the valve open position and acts as a valve closing position to move it to the valve closed position. It is set up like this. The valve opening device is a spring receiver 13
due to high fluid pressure acting on the rear surface of the
The valve closing position was determined by high fluid pressure acting on the front surface of the spring receiver 13. Then, when the mold is at a low temperature when the molding machine is started, or during low-speed injection, the electromagnetic switching valves 33a, 33b, etc., which will be described later, are switched by a remote device, and the valve closing position is activated.
can now be forcibly closed.

Projections 9c are provided on both sides of the upper end of the spool 9 to form a T-shape, and these projections 9c are slidably fitted into T-grooves 19a formed in the block 19. 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 movable mold 2 side.

A presser metal fitting 25 is attached to the front surface of the block 19 via thumbscrews 24 and is removably attached, and a proximity sensor 36 is attached to this presser metal fitting 25.
is fixed.

Further, the block 19 has a protrusion 1 in a part thereof.
9d, and this protrusion 19d is slidably fitted into a guide rod 28 provided on the side of the support frame 20, and guides the spool 9 when it is raised or lowered, as will be described later.

The block 19 to which the upper end of the spool 9 is connected has a backing plate 29 on the side opposite to the presser metal fitting 25.
is fixed at its upper end with a bolt 30. The lower end of the backing plate 29 extends toward the spool 9 side.

Furthermore, connecting holes 29a and 29b are formed at the lower end and center of the backing plate 29 for connection to an air source, and these connecting holes 29a and 29b are connected to the chamber 14 formed at the upper end of the spool 9. It communicates with through holes 14a and 14b that are continuous at the lower and upper portions. Then, at the edges of the through holes 14a and 14b, the connecting hole 29
O-rings 22 are placed in contact with the edges of a and 29b.
is attached, and the structure is such that the joint between the two can be kept airtight.

The connecting hole 29a has a pipe 31 and an electromagnetic switching valve 33a.
The pressure regulating valve 35 is connected to the connecting hole 29b via the A port of the electromagnetic switching valve 33b via the piping 32.
5 is connected, and this valve 35 is further connected to a compressed air source 36.

A patch plate 29 as described above is provided, and the connection hole 29 is
A, 29b is in contact with the spool 9.
If the structure with the ring 22 is adopted, the spool 9 can be inserted into the T-groove 19a when cleaning the degassing device.
It is possible to easily remove only the spool 9 and valve 7 by pulling it out from the holder. Therefore, the backing plate 29 remains as it is, and the pipes 31 and 32 on the air source 36 side remain as they are on the block 19 side, and there is no need to attach or detach the pipes, making cleaning and maintenance operations extremely easy. Of course, when attaching the spool 9 to the block 19, push the spool 9 into the T-slot 19a,
It can be attached extremely easily by simply pressing it against the backing plate 29 and locking it with the presser fitting 25.

Next, the operation of the gas venting device configured as above will be explained.

When starting up the injection molding apparatus, first, the electromagnetic switching valve 33a is turned on for the degassing device which is raised to a position away from the mold side, and the air pressure from the air source 36 is applied to the lower chamber of the chamber 14. lead to. Then, the pressure on the lower side of the spring receiver 13 increases, and the valve 7 is raised against the pressing force of the steel ball 17, and the valve 7 is closed.

Note that the air pressure above the spring receiver 13 is controlled by the solenoid valve 3.
In order to escape to the exhaust port 3b, the valve 7 is smoothly raised.

In this state, the cylinder 21 is operated to lower the entire spool 9. Of course, after lowering the entire spool 9, turn on the electromagnetic switching valve 33a,
Valve 7 can also be kept closed.

When the fixed mold 1 and the movable mold 2 are clamped in this state, low-speed injection can be performed with the valve 7 closed. Although the inertial force of the molten metal is small during low-speed injection, since the valve 7 is closed in advance, the molten metal does not go around to the valve chamber 11 side.

Several shots are performed in this manner until the mold warms up.

On the other hand, after the mold has warmed up, the injection operation is performed by a combination of low-speed injection and high-speed injection, but at this time, the molten metal has a large inertial force, so
There is sufficient force to close the valve 7, and it is necessary to prevent the valve 7 from being closed by the shock when the spool 9 descends.

In this case, the electromagnetic switching valve 33b is turned on.

As a result, the spring receiver 13 having a piston structure
Air pressure is introduced to the upper side, and this air pressure causes valve 7 to
is lowered against the force of the compression spring 15, the valve 7 remains open, and then the cylinder 21 is actuated and the spool 9 is lowered to release the half-split part built into the movable mold 2. Although it is attached to the seat 2a, the valve 7 will not close even if a shock occurs at that time. After the spool 9 has descended, the electromagnetic switching valve 33b is turned off, but the steel ball 17 is pressed against the lower end step of the small diameter portion 7c of the valve stem 7b, and the valve head 7a is separated from the valve seat 10, that is, the valve 7 remains open.

When the fixed mold 1 and the movable mold 2 are clamped in this state, a passage is formed from the cavity 4 to the outside of the spool 9 via the gas vent path 5, the gas vent groove 6, the passage 8, and the valve chamber 11. Further, after clamping the fixed mold 1 and the movable mold 2, actuate the cylinder 21, lower the spool 9 while keeping it in the same manner as described above, and then turn off the electromagnetic switching valve 33b. is also being implemented.

Then, in this state, an injection plunger (not shown) operates to supply molten metal into the cavity 4. At this time, the molten metal filling the cavity 4 advances through the gas vent passage 5 and the gas vent groove 6, but the gas inside the cavity 4 passes through the passage 8 and the valve chamber 11 and flows toward the discharge port 12. Head over. 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 be thrown 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 due to the gas coming in,
Since the valve 7 is given the tendency to move upward by the force of the compression spring 15, the exhaust passage is reliably closed by the valve 7.

Injection is performed in this way, 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, and then 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, air pressure is applied to the spring receiver 13 as described above, and the spring receiver 13 is pulled up from the compression spring 1.
5, push downward to open the valve 7, and clean the valve head 7a, valve seat 10, etc. with compressed air.

If such a degassing device is used, degassing can be reliably performed during casting, and the quality of the product can be significantly improved. Moreover, fixed mold 1
After clamping the movable mold 2, the spool 9 is lowered by the cylinder 21, and the bottom surface of the valve head installation holes 11c, 11d in the lower part of the valve chamber 11 and the valve head 7a of the valve 7 on the inner peripheral surface are removed. If foreign matter such as molten metal scum or baked-on matter is attached to the area where the bottom surface and the lower outer circumferential surface contact, the foreign matter such as molten metal scum or baked-on matter may be attached to the valve head 7a when the spool 9 is lowered. If the compression spring 16 and the steel ball 17, which are in contact with each other and are provided in the through hole 9a, are applied with a force greater than the force that overcomes the elastic force of the compression spring 15 and holds the valve 7 in the open position, The valve 7 is moved upward from the valve open position to the valve closed position, and the valve position detection sensor 36 is activated and sends a signal to the illustrated control device of the injection cylinder.
Casting work can be avoided. Therefore, defects such as poor degassing do not occur.

[Problem that the invention seeks to solve]

Spring receiver 1 serving as a piston in a piston cylinder device in a gas venting device for a mold
3 is fixed to the upper end of the valve stem 7b, and the valve 7 can be forcibly closed by applying high fluid pressure to the front and rear surfaces of the valve stem 7b.
5, the valve can be held in the open position against the force of the second holding device.
In order to apply high fluid pressure to the front or rear surface of the spring receiver 13, which is a piston, the smaller the gap between the spring receiver 13 and the chamber 14, the better. It is necessary to move smoothly from the valve open position to the valve closed position, and therefore it is preferable that the spring receiver 13 and the chamber 14 have a sufficient clearance in consideration of thermal expansion.
Therefore, the valve 7 can be opened and closed by applying the fluid pressure to the front or rear surface of the spring receiver 13, and a gap is provided so that the valve 7 can be smoothly closed by the inertial force of the molten metal. With such a gap, the pressure adjustment valve 35 is adjusted to the minimum pressure that allows the valve 7 to open and close smoothly while the mold gas venting device is moved away from the mold side. If this is done, for example, if dust or the like gets into the gap between the spring receiver 13 and the chamber 14, or if the temperature of the spring receiver 13 rises more than expected during casting, the valve 7 can be opened and closed smoothly at first. When the pressure was adjusted to a certain level, valve 7
Since the opening operation of the valve 7 is no longer possible and the movement of the valve 7 is not smooth, countermeasures can be taken.
Molten metal can be prevented from going around to the valve chamber 11 side.

However, as mentioned above, at the lowest pressure at which the valve 7 can open and close smoothly, the spool 9 is in contact with the cylinder 2.
It often happens that the valve 7 closes due to the shock caused by the lowering of the chamber 14, and as a means to prevent this, the pressure acting on the upper surface of the chamber 14 is increased by a pressure regulating valve, or the pressing force by the steel ball 17 is increased. I am increasing it. Therefore, dust may get mixed into the gap between the spring receiver 13 and the chamber 14,
Alternatively, even if the valve becomes extremely difficult to move due to a rise in temperature during casting, high fluid pressure is activated, allowing the valve 7 to open and casting to be performed. If this happens, the valve 7 will not move smoothly in the valve closing direction due to the inertial force of the molten metal, and the molten metal may go around to the valve chamber 11 side.

In addition, when attaching the mold gas venting device to the movable mold and inserting it into the gas venting valve unit installation position, the bottom surface of the valve head installation hole 11c at the bottom of the valve chamber 11 and the valve 7 on the inner circumferential surface. If foreign matter such as molten metal scum or baked-on matter is attached to the part where the bottom surface of the valve head 7a and the lower outer circumferential surface contact, the valve head 7a and the valve head installation hole 11c will be exposed to the molten metal when the spool 9 is lowered. The compression spring 16 and the steel ball 17 in the through hole 9a are in contact with each other through foreign matter such as scum or baked-on material, and the compression spring 15
If a force greater than the force that overcomes the elastic force of and holds the valve 7 in the open position is applied, the valve 7 will be moved upward from the valve open position to the valve closed position, but as described above,
If the pressure applied to the upper chamber of the chamber 14 is increased to prevent the valve 7 from closing due to the downward shock of the cylinder 21, or if the pressing force by the steel ball 17 is increased, a small amount of molten metal scum or baked-on matter may be generated. It has also been confirmed that if foreign matter remains, the valve 7 is not moved upward from the valve open position to the valve closed position, and the mold is clamped as it is, and the valve closing operation due to the inertia of the molten metal is not performed smoothly. . Furthermore, even if there is no debris such as molten metal scum or baked-on material attached to the movable side valve head installation hole 11c, if it is attached to that on the fixed side, the valve head 7a is similarly The valve head installation hole 11d comes into contact with the valve head installation hole 11d through these foreign objects, and even if the inertia of the molten metal acts, the valve cannot close smoothly, and the molten metal flows into the valve chamber 11.
It had the disadvantage of going around to the side.

[Means and actions for solving problems]

In the present invention, in order to solve the above-mentioned problems, in the conventional mold gas venting device as described above, after the valve 7 is set in advance to the valve closed position, the movable mold 2 or the fixed mold Insert the gas venting valve unit into the mold 1 installation position, then clamp the mold, and after the mold clamping is completed, remove the valve 7 with the mold gas venting device moved to a position away from the mold side. The valve is moved from the valve close position to the valve open position using the pressure adjusted using the pressure regulating valve 35 so that it can be opened and closed smoothly.If the valve does not open at that pressure, the inertia of the molten metal Since the valve closing operation by force was not performed smoothly, the valve position detection sensor 36 was activated and sent a signal to the control device of the injection cylinder to prevent the casting operation from being performed.

〔Example〕

The method of the present invention will be explained in detail below.

[First Embodiment] In the first embodiment of the present invention, the following method was adopted in order to solve the problem that occurs when setting the degassing valve unit to the installation position with the valve open.

That is, the gas venting device (gas venting valve unit) 3
The pipe 31 is located at a position away from the mold side.
Air is supplied from the air source 37 to the lower side of the spring receiver 13 of the chamber 14 through
is seated on the valve seat 10, and the valve 7 is kept closed.

In this state, the entire degassing device 3 is lowered by the cylinder 21 and is seated on the seat 2a.

After that, the mold clamping operation is performed, and after the mold clamping is completed, the air pressure below the spring receiver 13 is released, and the air pressure is sent to the upper side of the spring receiver 13 to lower the valve 7.
The valve head 7a is separated from the valve seat 10 to open the valve 7.

The air pressure at this time is set to a small enough force to open the valve 7, for example, about 2.5 to 3 kg/cm ² .

If the valve portion of the degassing device is set in this manner, the valve will not close due to the shock during installation.

Furthermore, when the valve does not open with the above operation, it means that the valve is not closed due to the inertial force of the molten metal, and the valve position detection sensor 36 detects this and sends a signal to the control device of the injection cylinder. , prevent casting work from being carried out.

By employing the method described above, the degassing device can be set up reliably and is extremely safe.

[Second Example] In the second example of the present invention, the following method was adopted.

That is, the valve is closed in the same manner as in the first embodiment with the gas venting device 3 being separated from the mold side.

Next, the mold is clamped in this state, and after the mold clamping is completed, the degassing device 3 is inserted to the installation position,
The person is seated on seats 1a and 2a.

Subsequently, air pressure is supplied above the spring receiver 13 of the chamber 14 to lower the valve 7 and open the valve 7.

The air pressure at this time is also a small pressure for opening the valve 7, for example, 2.5 to 3 kg/cm ² .

Even if the method described above is adopted, the same effects as in the embodiment described above can be obtained.

In the case of this embodiment, after the mold clamping is completed, the gas venting device 3 with the valve 7 closed is inserted into the installation position between the molds 1 and 2, and is seated on the seats 1a and 1b, and then,
The valve 7 may be opened.

〔effect〕

As is clear from the above description, according to the present invention, a method is adopted in which the degassing device is charged to the installation position with the valve closed. The valve does not close with a shock.

Further, after the gas venting device is inserted, the valve is opened, but if the valve does not open at this time, the valve position detection sensor detects this and stops the injection operation, so it is extremely safe.

[Brief explanation of drawings]

The drawings show one embodiment of a degassing device for carrying out the conventional method and the method of the present invention.
FIG. 1 is a longitudinal side view, and FIG. 2 is a front view. 1... Fixed mold, 2... Movable mold, 3... Gas venting device, 7... Valve, 9... Spool, 13...
Spring receiver, 14... chamber, 21... cylinder.

Claims (1)

[Scope of Claims] 1. A gas vent for a mold, in which a gas vent valve unit is removably installed at the gas vent valve unit installation position provided at the end of a gas vent groove led from a cavity in a separation surface of a mold. Using the device, the gas venting valve unit includes a valve having a valve head that can be freely inserted into and taken out from a valve head installation hole provided at the end of the gas venting groove, and this valve is slidably supported, Using a degassing valve unit which itself has a spool that can slide in the axial direction, the valve is inserted into the degassing valve unit installation position with the valve previously slid to the valve closing position, and then the mold clamping operation is performed. A method for installing a valve part in a gas venting device for a mold, wherein the valve is slid to an open position after mold clamping is completed. 2 Using a gas venting device for a mold, in which a gas venting valve unit is removably installed at the installation position of the gas venting valve unit provided at the end of the gas venting groove led from the cavity of the separation surface of the mold, the gas is removed. The vent valve unit includes a valve that has a valve head that can be freely inserted into and taken out from a valve head installation hole provided at the end of the gas vent groove, and a valve that supports the valve so that it can slide freely and that itself extends in the axial direction. Using a degassing valve unit with a slidable spool, after mold clamping is completed, the degassing valve unit with the valve previously slid to the valve closing position is inserted into the degassing valve unit installation position, and then the A method for installing a valve part in a mold degassing device in which the valve is slid to an open position.