JP2003112232A - Gas vent device for die, and method for using the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To open/close a closing valve with a small force in the maintenance irrespective of any releasing resistance in a valve body. SOLUTION: In a gas vent device for a die in which a passage 8 communicated with a cavity comprises a fixed die 10 and a movable die 11, a closing valve 13 in which the valve body 26 slides within a cylindrical bush 25 is provided on an outlet side of the passage, a bearing pin 12 is slidably provided on an inlet side of the passage, a part in the middle of the length of a lever 14 which is supported in an oscillating manner is pressed by the bearing pin, a tip part of the lever is engaged with a head part of the valve body, and the pressing motion of the bearing pin by the rise of the pressure of the molten metal in the passage is converted into the valve body via the lever to close the closing valve, an opening cylinder 15 to open the closing valve is provided on the fixed die, and the opening cylinder is provided so as to directly press the head part of the valve body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for degassing a cavity in a mold casting and a method of using the apparatus.

[0002]

2. Description of the Related Art As a mold degassing device of this type,
There is one disclosed in Japanese Patent Application No. 2000-337686. As shown in FIG. 8, a passage 102 communicating with the cavity is formed between a fixed die 100 and a movable die 101, a closing valve 103 is arranged on the outlet side of the passage, and a lever 104 for opening and closing the closing valve is provided. A pressure receiving pin 105 that is swingable and that pushes the lever when the molten metal pressure in the passage increases is provided slidably on the inlet side of the passage, and further includes an opening spring 106 that constantly presses the lever.

However, in this case, since the valve body 107 of the closing valve is pushed out by the force of the opening spring when the mold is opened, a large spring load is used as the opening spring. Therefore, due to the load, it was difficult to push the valve body with a finger during maintenance. As a result, the task of confirming the opening / closing condition of the closing valve, that is, the task of pushing the valve body against the opening spring to confirm whether or not the valve normally operates, has been troublesome. In the closing valve described above, the tip surface of the valve body, that is, the molten metal contact surface is formed as a smooth surface so that the mold release resistance is not obtained. I had to push it out.

[0004]

SUMMARY OF THE INVENTION The problem to be solved by the invention of claim 1 developed in consideration of the above situation is to open a closing valve with a light force during maintenance regardless of whether the valve body has a mold release resistance or not. It is to be able to open and close.

Further, a problem to be solved by the invention of claim 2 is to enable the closing valve to be opened with a light force when the mold is opened even when there is no mold release resistance.

By the way, there is a closing valve such as a poppet valve which is in close contact with the valve seat to maintain the closed state.
It is provided so as to be able to project and retract inside, so that the passage is closed and the molten metal is not discharged when the tip part is retracted into the bush. Therefore, the size of the clearance between the bush and the tip of the valve body cannot be designed wider than a certain value. Then, when the heat of the molten metal is received, the valve main body and the bush thermally expand and the clearance disappears. In addition, when the mold is opened, the force of the opening spring is indirectly applied from the lever to the valve body, but because the valve body and the bush are in close contact with each other due to the thermal expansion, the closing valve remains closed. I am maintaining. Then, after a lapse of a fixed time, for example, several seconds, immediately after the mold is opened, heat is released and a clearance is formed again, and the valve body is pushed out by the force of the opening spring to open the closing valve.

However, as described above, the force of the opening spring is not applied to the valve body after the clearance is sufficiently opened, but is applied from the time when there is no clearance, so the clearance when the valve body starts to move in the opening direction. Can be said to be narrower than the ideal interval for smooth sliding. Therefore, since the valve body is forcedly pushed and moved, wear is severe and durability is shortened.

Further, the clearance between the tip portion of the valve body and the cylinder cannot be set to a certain value or more even if the diameter of the valve body is increased, for the reason described above.
As the diameter of the valve body increases, the clearance between the valve body and the cylinder disappears when the valve body thermally expands, rather than pressing firmly.
Therefore, it takes a long time until the clearance is formed, and the force of the opening spring takes a long time, which further adversely affects the durability.

According to the third and fourth aspects of the invention, in addition to the problem of the second aspect of the invention, the timing for opening the closing valve can be set to wait until the clearance is sufficiently formed. is there.

[0010]

The solution of the present invention is to equip a fixed mold with an open cylinder for opening a closing valve, and the open cylinder is provided so that the crown of the valve body can be directly pushed in.

As a premise of the mold degassing device,
A fixed type and a movable type are provided, and a passage leading to the cavity is formed by the fixed type and the movable type, and a closing valve in which the valve body slides in a tubular bush is provided on the outlet side of the passage. A pressure receiving pin is provided slidably on the inlet side so that the middle part of the length of the lever supported so that it can swing can be pushed in by the pressure receiving pin, and the tip of the lever engages with the head of the valve body to allow passage. The closing valve is closed by changing the pushing motion of the pressure receiving pin due to the rise of the molten metal pressure into the forward movement of the valve body via the lever.

The fixed mold and the movable mold can be attached not only when the fixed mold is fixed to the fixed mold and the movable mold is fixed to the movable mold, but the fixed mold is fixed to the movable mold and the movable mold is fixed to the fixed mold. May be installed. The passage is not limited to a single passage leading to the cavity, and may be a plurality of passages. Therefore, the inlet side of the passage here means the position before the molten metal reaches the closing valve.

As the mold degassing device, a mold body may be used in which the tip end surface of the valve body that comes into contact with the molten metal is provided with unevenness for mold release resistance. In this case, the open cylinder is activated at the beginning of casting. Further, in the mold degassing device, the tip surface of the valve body that comes into contact with the molten metal is formed into a smooth surface, and the degree of smoothness is determined by the force with which the surplus member is taken out when the mold is opened and the bubble body is separated from the closed state. You may use the thing of a maintenance level. In the latter case, the open cylinder will also be activated during mold opening.

Further, the closing valve of the mold degassing device is provided with the tip of the valve body in the bush so that the tip of the valve body can be retracted, and a clearance for retracting is provided between the tip of the valve body and the bush. It is also possible to use a valve in which the passage is opened with the tip of the main body protruding and the passage is blocked with the tip of the valve main body retracted.

The method of using the mold degassing apparatus of the present invention is to attach the mold degassing apparatus to a fixed mold and a movable mold, fill the cavity with molten metal, and let the molten metal overflowing from the cavity die. Flow into the passage of the degassing device, push in the pressure receiving pin, indirectly move the valve body forward through the lever to close the closing valve, and the bush thermally expanded by the heat of the molten metal and the tip of the valve body After closely contacting and solidifying the molten metal, the mold is opened and the surplus member is taken out.
After waiting until the clearance between the bush and the tip of the valve body is formed by cooling by taking out,
It is characterized in that the opening cylinder is operated to directly push the valve body to open the closing valve. Further, the closing valve of the mold degassing device used in this method is provided with a tip portion of the valve body in the bush so that the tip portion of the valve body can be retracted, and a clearance for retracting is provided between the tip portion of the valve body and the bush. It is assumed that the passage is opened when the tip of the valve body is projected, and the passage is cut off when the tip of the valve body is retracted.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 4 shows an outline of a mold,
1 is a fixed mold, 2 is a movable mold, 3 is a cavity fixed mold,
4 is a movable cavity type, 5 is a cavity, and the molten metal injected into the injection sleeve 6 provided in the fixed mold 1 is press-fitted into the cavity 5 by the injection piston 7.
The degassing device 9 is provided with a passage 8 provided continuously to the cavity 5.
A gas suction device 9 is connected to a suction device (not shown).

As shown in FIG. 1, the degassing device 9 comprises a fixed die 10 attached to a fixed die 1 and a movable die 11 attached to a movable die 2, and the fixed die 10 and the movable die 11 form a passage 8. The pressure receiving pin 12 is slidably provided on the inlet side of the passage 8 and the closing valve 13 is provided on the outlet side of the passage 8, and the lever 14 for changing the forward movement of the pressure receiving pin 12 into the closing movement of the closing valve 13 is formed. It has an open cylinder 15 that swingably supports and directly presses the closing valve 13 to open it, and an auxiliary closing cylinder 16 that presses the lever 14 to indirectly close the closing valve 13.

The passage 8 has a cavity 5 as shown in FIG.
There is one flow passage 17 leading to the pressure receiving pin 12 on the inlet side, and then the flow passages 18, 18 branched into two branches.
Is connected to the closing valve 13 on the outlet side, and as shown in FIG. 6, there are a plurality of flow paths 17 communicating to the cavity 5, one of which is connected to the pressure receiving pin 12 and the other is connected to the closing valve 13. is there. And in each case, the melt is closed valve 1
Before the pressure reaches 3, the pressure receiving pin 12 is pushed in by pressurization of the molten metal and the closing valve 13 is closed. In addition, the passage 8 will be described separately before reaching the closing valve 13 and after reaching the closing valve 13. Before reaching the closing valve 13, the passage 8 is formed on the mating surface of the fixed mold 10 and the movable mold 11. It is formed in the fixed mold 10 by being bent into an L shape. The movable die 11 is a block having a flat mating surface.

The fixed mold 10 includes a main block 19 and a cover 20.
Is attached to the opposite side of the mating surface, the main parts such as the closing valve 13 are built in, and the auxiliary block 21 in which the opening cylinder 15 is built in the extension direction of the closing valve 13 is fixed to the cover 20.

The main block 19 is provided with a closing valve 13 from the outlet side of the passage 8 toward the cover 20 side, and extends the pin accommodating chamber 22 at the inlet side of the passage 8 toward the cover 20 side.
The pressure receiving pin 12 is slidably accommodated in the pin accommodating chamber 22. Further, on the cover 20 side of the main block 19, a pin chamber 22 and a lever chamber 23 communicating with the head of the closing valve 13 are formed, and the lever 14 is swingably provided in the lever chamber 23.
The intermediate portion of the lever 14 is provided so as to be able to be pushed in by the pressure receiving pin 12, the tip end portion of the lever 14 is openably and closably engaged with the head portion of the closing valve 13, and the auxiliary closing cylinder 16 is provided between the pressure receiving pin 12 and the closing valve 13. Have

The closing valve 13 has a valve accommodating chamber 24 formed from the outlet side of the passage 8 toward the cover 20 side.
Is used as a part of the valve accommodating chamber 24. A tubular bush 25 is provided in the valve accommodating chamber 24, a valve main body 26 is slidably provided in the bush 25, and a tip end portion of the valve main body 26 is provided so as to be retractable in the bush 25 with a clearance. .

The bush 25 has a hole 2 for passage on the front side.
7 is formed, and a hole 28 through which the lever 14 is inserted is formed on the head side. The valve body 26 has a cylindrical shape and the lever 14 is attached to the head.
A horizontal hole 29 for inserting the hole is formed, the tip portion is formed to be slightly thinner to form a gap for the passage with the bush 25, and the melt outflow is prevented in a state where the thick tip portion is immersed.

The bush 25 and the valve body 26 are thermally expanded by receiving the heat of the molten metal. Both materials having a thermal expansion coefficient of 11.56 × 10 ⁻⁶ / mm ° C. are used. When a diameter of 10 mm to 29 mm was used, the clearance between the tip of the valve body 26 and the bush 25 was set to 15 μm.

When the tip end of the valve body 26 and the bush 25 are brought into contact with the molten metal and thermally expanded, the above-mentioned clearance disappears and they come into close contact with each other. If sliding is made in close contact, durability will be reduced, so sliding will be made to wait until the clearance required for smooth sliding is formed. The required clearance dimension is 2 microns or more.
When the molded product is taken out from the cavity 5, the surplus member 30 in the passage 8 is taken out at the same time, and the tip surfaces of the valve body 26 and the bush 25 come into contact with air to be cooled. By the time
It took 1 second for a diameter of 10 mm. The time until the required clearance is formed increases as the diameter of the valve body 26 increases, and the diameter is 29 m.
It took 5 seconds with m.

Further, in the experiment, when the temperature of the tip portion of the valve body 26 becomes higher than that of the bush 25 by 45 ° C. or more, the tip portion of the valve body 26 cannot enter the bush 25. Therefore, in order for the tip portion of the valve body 26 to smoothly project and retract in the bush 25, the temperature of the tip portion of the valve body 26 should be 0 ° C. or more and 45 ° C. or more than the temperature of the bush 25.
The condition must be less than.

The pressure receiving pin 12 is provided with a collar 31 for supporting on the head side.
And a protrusion 32 that abuts the lever 14. Further, the tip end surface (the molten metal contact surface) is provided with irregularities so that a mold release resistance can be obtained.

In the swinging mechanism of the lever 14, the shaft support lid 33 is fixed to the inner surface of the cover lid 21, and a part of the lever chamber 23 is moved to the lever 1.
4 is formed to be slightly wider than the supporting end portion of No. 4, and the supporting end portion of the lever 14 is inserted into the slightly wider portion.

The auxiliary closing cylinder 16 is operated at the beginning of casting. That is, at the beginning of casting, the molten metal is filled into the cavity 5 at a lower speed than during normal operation, so that the pressure receiving pin 1
Since 2 is hard to move, before the molten metal reaches the closing valve 13, the auxiliary closing cylinder 16 is operated to push the lever 14 and close the closing valve 13. Specifically, a closed cylinder chamber 34 is formed between the pin accommodating chamber 22 and the valve accommodating chamber 24 so as to communicate with the lever chamber 23, and the closed cylinder chamber 34 is reciprocated with the closing piston 35 in contact with the lever 14. It is movably provided, communicates with the outside from the closed cylinder chamber 34 through a communication path 36, and reciprocates the closed piston 35 by an air pressure circuit (not shown) using an air compressor.

The open cylinder 15 is a single-acting air cylinder that can be operated not only when the mold is opened but also at the beginning of casting.
An open cylinder chamber 37 is formed in the extension direction of the valve body 26, and an open piston 38 is provided in the open cylinder chamber 37.
A through hole 4 through which a spring is passed through the piston rod 39 and the tip of the piston rod 39 moves in and out of the bush 25.
0 is opened in the cover lid 20, the top of the valve body 26 can be pushed by the tip of the piston rod 39, and the communication path 41 is provided in the open cylinder chamber 37 so as to communicate with the outside, and is operated by an air pressure circuit by an air compressor. .

The timing at which the open cylinder 15 is operated is controlled by a controller (not shown). Specifically, after the mold is opened, the measurement is started from the time when the molded product is taken out from the cavity, and the process waits until the clearance of 2 microns is opened. Then, the air is supplied into the open cylinder 15 to supply the piston rod 39. Then, the valve body 26 is pushed in to move back, and the closing valve 13 is opened.

The mold degassing device 9 described above is used in the following procedure. First, the mold degassing device 9 is attached to the fixed mold 1 and the movable mold 2, and then the mold is clamped as shown in FIG. 2 to fill the cavity 5 with the molten metal. Cavity 5
The molten metal overflowing from the inside flows into the passage 8 of the mold degassing device 9, pressurizes the pressure of the molten metal before the molten metal reaches the closing valve 13, pushes the pressure receiving pin 12, and indirectly through the lever 14 the valve body 26. 3, the tip of the valve body 26 is retracted into the bush 25 to close the closing valve 13, as shown in FIG. When closed, there is a clearance between the tip of the valve body 26 and the bush 25,
After that, the heat of the molten metal that has reached the closing valve 13 causes the bush 25 and the tip portion of the valve body 26 to thermally expand, and the clearance disappears and they come into close contact with each other. Then, after the molten metal in the passage 8 is solidified and becomes the surplus member 30, the mold is opened and the surplus member 30 is taken out. However, since the tip end surface of the valve body 26 is formed to be a smooth surface, the surplus member 30 is made to surplus. Member 30
The valve body 26 is separated from the valve body 26, and the valve body 26 is stopped at the forward position. Further, since the pressure receiving pin 12 is provided with a mold release resistance concavo-convex, the pressure receiving pin 12 is moved back by the momentum taken out.
After that, since the clearance between the bush 25 and the tip of the valve body 26 is formed by heat radiation, wait until the dimension required for smooth sliding is reached, and then open the cylinder 15 as shown in FIG. Operate the valve body 26
Is directly pushed in to return and the closing valve 13 is opened.

FIG. 7 shows another example of the mold degassing device 9, which is the same as the previous example except that a double-acting cylinder that reciprocates with air is used as the open cylinder 15.

The present invention is not limited to the above embodiment. For example, the tip end surface of the pressure receiving pin 12 may be formed into a smooth surface. In this case, since the pressure receiving pin 12 does not move back even if the surplus member 30 is taken out at the time of mold opening, the opening cylinder 15 needs a force not only for the valve body 26 but also for pressing the pressure receiving pin 12 at the same time. Become. Further, in the fixed mold 10, the cover 20 and the auxiliary block 21 are separately molded products in the drawing, and the auxiliary block 21 is fixed to the cover 20. However, the cover 20 and the auxiliary block 21 may be integrally molded products. .

[0034]

According to the first aspect of the present invention, since the open cylinder directly pushes the crown of the valve body, the pushing point is the farthest point from the fulcrum of the lever.
The valve body can be moved with a weak force. In addition, since the force in the opening direction is not applied to the valve body unless the open cylinder is operated, the valve body can be directly pressed with a finger to check the movement when performing maintenance.

Further, according to the invention of claim 2, since the front end surface of the valve body is a smooth surface, the valve body is maintained in the closed state even if the surplus member is taken out. As a result, the opening cylinder is opened when the mold is opened. It can be activated to open the closure valve.

According to the third and fourth aspects of the invention, since the bush has the valve body with the tip end thereof protruding and retracting is used as the closing valve, the opening cylinder is opened when the clearance for retracting disappears due to the heat of the molten metal. If the open cylinder is operated after the heat is dissipated and the clearance is sufficiently formed without the operation, the wear between the bush and the tip of the valve body is suppressed, and the durability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a mold degassing device of the present invention,
It shows a state in which the open cylinder is operated after the mold is opened.

FIG. 2 is a cross-sectional view showing a state of a die degassing device before press-fitting of molten metal.

FIG. 3 is a cross-sectional view showing a state in which a closing valve of a mold degassing device is closed with molten metal.

FIG. 4 is a cross-sectional view showing a state in which a mold degassing device is attached.

FIG. 5 is a view showing a passage of a mold degassing device.

FIG. 6 is a view showing a passage of another mold degassing device.

FIG. 7 is a cross-sectional view showing another example of a mold degassing device.

FIG. 8 is a cross-sectional view showing a conventional mold degassing device.

[Explanation of symbols]

1 Fixed mold 2 movable mold 5 cavities 8 passages 9 Mold degassing device 10 fixed type 11 movable 12 Pressure receiving pin 13 Closure valve 14 lever 15 Open cylinder 25 bush 26 Valve body 30 surplus members

Claims (4)

[Claims] 1. A fixed mold (1) comprising a fixed mold (10) and a movable mold (11), wherein a passage (8) leading to a cavity (5) is provided.
0) and the movable mold (11), and has a closing valve (13) on the outlet side of the passage (8), in which the valve body (26) slides in the tubular bush (25). A pressure receiving pin (12) is slidably provided on the inlet side of the passage (8),
The lever (14), which is swingably supported, has an intermediate length portion that can be pushed in by the pressure receiving pin (12), and the tip of the lever (14) is engaged with the head of the valve body (26) to form a passage. (8) The pressure receiving pin (1
In the mold degassing device for closing the closing valve (13) by changing the pushing movement of 2) to the forward movement of the valve body (26) via the lever (14), the opening cylinder (15) for opening the closing valve (13). ) Is provided in the fixed mold (10), and the open cylinder (15) is provided so that the crown of the valve body (26) can be directly pushed in. 2. The valve body (26) contacting the molten metal is formed with a smooth end surface, and the degree of smoothness is such that the bubble body (26) is separated by the force of taking out the surplus member (30) when the mold is opened. The degassing device for a mold according to claim 1, wherein the closed state is maintained. 3. The closing valve (13) comprises a bush (2).
5) a tip portion of the valve body (26) is provided so as to be retractable, and a clearance for retracting is provided between the tip portion of the valve body (26) and the bush (25).
The passage (8) is opened with the front end of 6) protruding, and the passage (8) is opened with the front end of the valve body (26) retracted.
The mold degassing device according to claim 2, wherein 4. The mold degassing device (9) according to claim 3 is attached to a fixed mold (1) and a movable mold (2),
The cavity (5) is filled with the molten metal, and the molten metal overflowing from the cavity (5) flows into the passage (8) of the mold degassing device (9) to push the pressure receiving pin (12), and the lever (14). The valve body (26) is indirectly moved forward via the valve to close the closing valve (13), and the bush (25) thermally expanded by the heat of the molten metal and the tip of the valve body (26) come into close contact with each other, and the molten metal After solidifying, the mold is opened and the surplus member (30) is taken out, and after that, it is waited until the clearance between the bush (25) and the tip of the valve body (26) is formed by cooling by taking out, and then the open cylinder. A method of using a degassing device for a mold, which comprises actuating (15) to directly push the valve body (26) to open the closing valve (13).