JPH09267162A - Gas vent valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To close a vent passage even when the pushing force of a pressure receiving member is reduced by interlocking the pressure reception with the closing in the same direction in closing the vent passage by shifting the molten metal flowing into the vent passage by the pressure receiving member. SOLUTION: The molten metal which is rapidly filled in a cavity flows into a vent pipe 208 in a gas vent valve 10. The molten metal having reached an end part 235 for the vent pipe pushes a molten metal receiving piston 201 inserted in a lower through hole 203 and moves the piston. As soon as the molten metal receiving piston 201 is moved, a zoom ring 210 is operated, a valve piston 202 is moved by the prescribed quantity in the same direction as the molten metal receiving piston 201 to close a gap 237 between a piston head 205 and a through hole 204. Even when the force to push the molten metal receiving piston 201 is small, the moving distance of a valve piston 202 is longer than the moving distance of the molten metal receiving piston 201, and the valve piston 202 can surely close the vent passage. Thus, the molten metal reacting an upper end part 206 of a branched duct from the end part 235 of the vent pipe does not flow out of an outlet part 207.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas vent valve formed in a mold, more specifically,
The present invention relates to a gas vent valve that opens and closes a vent passage for exhaust formed in a die casting mold.

[0002]

2. Description of the Related Art When a molten metal is poured into a cavity of a die casting mold, it is necessary to provide a portion where gas in the cavity escapes. Therefore, the die casting mold is provided with a ventilation path from the inside of the cavity to the outside of the mold. Then, in the middle of the air passage, after all the gas in the cavity escapes, that is, after the molten metal fills the cavity, the high-temperature molten metal is passed through the air passage to prevent it from flowing out of the mold. A vent valve is provided. For example, Japanese Unexamined Patent Publication No. 54-99735 discloses a gas vent valve 600 for die casting having the following structure. 6 shows the internal structure of the gas vent valve with the ventilation passage closed, and FIG. 7 shows a sectional view taken along line BB in FIG. A ventilation conduit 608 extends from a cavity final filling portion (not shown) to near the center of the die casting degassing valve 600. The ventilation conduit 608 is divided into two branch ducts 614 before reaching the ventilation conduit end 635. The two branch ducts 614 extend in the same direction as the extending direction of the ventilation conduit 608, and are respectively connected to two upper through holes 604 at the branch duct upper end portion 606 that extend perpendicularly to the extending direction of the ventilation conduit 608. . The two upper through holes 604 are connected to an outlet 607 that communicates with the outside of the mold at the side surface. A valve piston 602 is slidably inserted in the upper through hole 604. The valve piston 602 is provided with a piston head 605 whose outer diameter is equal to or larger than the inner diameter of the upper through hole 604. When the degassing valve 600 is not operating, the piston head 6
There is a gap between 05 and the upper through hole 604. A plurality of hot water receiving pistons 601 are provided in the ventilation conduit terminal portion 635 in parallel with the upper through hole 604. The hot water receiving piston 601 is connected to a transmission piston 634 connected to the companion plate 633. The companion plate 633 is fitted in an annular groove 632 formed in the center of the valve piston 602.

At the time of pouring, the air in the cavity is filled with the ventilation conduit 6
08, the branch duct 614, the piston head 605 and the upper through hole 604, and the outlet portion 607.
It is discharged outside the mold. Following the evacuation of all air in the cavity, the melt flows into vent conduit 608. The molten metal reaches the ventilation conduit end portion 635, and the molten metal receiving piston 6
Press 01. Along with that, the conduction piston 634 connected to the hot water receiving piston 601 moves. Simultaneously with the movement of the conduction piston 634, the companion plate 633 connected to the conduction piston 634 also moves. Then, the valve piston 602 connected to the companion plate 633 via the annular groove 632 moves, and the piston head 6 provided on the valve piston 602 moves.
The gap between the upper through hole 604 and 05 is closed. By the above operation, the gap between the piston head 605 and the upper through hole 604 is blocked, so that the molten metal reaching the upper end 606 of the branch duct does not flow out to the outlet 607.

[0004]

By the way, the above-mentioned gas vent valve 600 for die casting has the following problems. It takes time for the molten metal to reach the degassing valve 600 through the cavity, and during that time, the molten metal loses heat by the mold, the dynamic pressure drops, and the hot-water receiving piston 601 cannot be pressed reliably. Since the hot water receiving piston 601 and the valve piston 602 are interlocked with each other, the moving distance of each is the same. If the hot water receiving piston 601 is not reliably pushed by the molten metal, the moving distance of the valve piston 602 is short and the piston head 60
5 and the upper through hole 604 are not sufficiently blocked.
Therefore, the high temperature molten metal will flow out of the die from the outlet 607. The present invention has been made in view of the above-mentioned problems, and it is possible to prevent the molten metal from leaking to the outside of the mold by reliably closing the ventilation path even when the molten metal cools and the force pushing the pressure receiving member decreases. Providing a valve is a problem to be solved.

[0005]

A gas vent valve according to the present invention is a gas vent valve that opens and closes an exhaust vent passage formed in a mold, and is a pressure receiving member that is moved by being pushed by the molten metal flowing into the vent passage. A member, a closing member that closes the air passage by a predetermined amount of movement, and the pressure receiving member and the closing member are linked in the same direction until the air passage is closed by the closing member, and And a connecting unit that connects the pressure receiving member such that the moving distance until the air passage is closed is longer than the moving distance of the pressure receiving member.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] Hereinafter, with reference to FIGS.
The degassing valve according to the first embodiment of the present invention will be described. The gas vent valve 10 according to the present embodiment is
The zoom link 210 is a means for connecting the hot water receiving piston 201 and the valve piston 202 in the same direction and connecting them so that the moving distance until the gap 237 of the valve piston 202 is closed is longer than the moving distance of the hot water receiving piston 201. Is used. FIG. 1 shows a usage state of the gas vent valve 10 according to the first embodiment. The vent valve 10 is on the side facing the injection plunger 70, and a vent conduit 208 extends from the final cavity filling portion 30 of the mold 40 into the vent valve 10.
The molten metal is injected into the injection plunger 70 by the pouring ladle 50.
The cavity 20 is poured into the cavity 20 by the plunger tip 80 provided at the tip of the plunger rod 90.
Sent inside. FIG. 2 is a vertical cross-sectional view of the gas vent valve 10 and shows the internal structure of the gas vent valve 10 in a state where the ventilation passage is not closed. The ventilation conduit 208 is connected to a lower through hole 203 extending in a direction perpendicular to the direction in which the ventilation conduit 208 extends at a ventilation conduit end portion 235 located near the center of the vent valve 10. In the lower through hole 203,
A hot water receiving piston 201 is slidably inserted. The hot water receiving piston 201 is connected to a spring 212, one end of which is fixed to the inner wall 211a of the gas vent valve, on the side facing the ventilation conduit 208, and is biased toward the ventilation conduit end portion 235. A projection 236 is provided at the center of the hot water receiving piston 201 so that the hot water receiving piston 201 does not project into the ventilation conduit 208. When the gas vent valve 10 is not operating, the protrusion 236 is in contact with the gas vent valve inner wall 211b. The ventilation conduit 208 is divided into two branch ducts 214 before reaching the hot water receiving piston 201, as shown in FIG. 3, which is a sectional view taken along line AA of FIG. 2. Each branch duct 214 is connected to two upper through holes 204 that extend parallel to the extending direction of the lower through hole 203 at the upper end 206 of the branch duct. The two upper through holes 204 are side surfaces and are connected to an outlet 207 that communicates with the outside of the mold. Upper through hole 2
A valve piston 202 is slidably inserted in 04. The valve piston 202 is provided with a piston head 205 whose outer diameter is equal to or larger than the inner diameter of the upper through hole 204. When the degassing valve 10 is not operating, there is a gap 2 between the piston head 205 and the upper through hole 204.
37 is open. The hot water receiving piston 201 and the two valve pistons 202 are connected by two zoom links 210 described later. The zoom link 210 extends in a direction perpendicular to the direction in which the lower through hole 203 extends, the lower end portion is inside the gas vent valve 10, the central portion is at the hot water receiving piston 201,
The upper ends are rotatably connected to the valve pistons 202, respectively. Since the structure inside the gas vent valve 10 is symmetrical with the hot water receiving piston 201 sandwiched, only one side will be described in the following description.

The molten metal that has been filled into the cavity 20 at a high speed and has reached the cavity final filling portion 30 flows into the ventilation conduit 208. The molten metal that has reached the aeration conduit terminal portion 235 pushes and moves the hot water receiving piston 201 inserted in the lower through hole 203. At the same time as the hot water receiving piston 201 moves,
The zoom link 210 operates, and the valve piston 202 connected through the zoom link 210 moves in the same direction as the hot water receiving piston 201 by a predetermined amount, and the piston head 20
5 and the gap 237 between the upper through hole 204 is closed. Since the movement of the zoom link 210 is a circular motion centered on the coupling portion at the lower end, the moving distance at the upper end portion is longer than that at the central portion. As for the moving distance Sm of the valve piston 202, the distance from the valve piston 202 to the lower end of the zoom link 210 is L, and the hot water receiving piston 201 to the zoom link 21.
0 If the distance to the lower end is 1, and the moving distance of the hot water receiving piston 201 is Sj, it can be expressed as follows. Sm = Sj * (L / l) Since L is longer than l, the valve piston 202 moves longer than the moving distance of the hot water receiving piston 201. Further, by setting the hot water receiving piston 201 by changing the distance from the coupling portion at the lower end of the zoom link 210, the moving distance of the valve piston 202 at the upper end portion of the zoom link 210 can be adjusted. As described above, even when the force for pushing the hot water receiving piston 201 is small, the moving distance of the valve piston 202 is longer than the moving distance of the hot water receiving piston 201, so that the valve piston 202 can reliably close the ventilation path. Therefore, the molten metal that reaches the upper end portion 206 of the branch duct through the branch duct 214 from the end portion 235 of the ventilation conduit does not flow out from the outlet portion 207.

[Second Embodiment] A degassing valve according to a second embodiment of the present invention will be described below with reference to FIG. FIG. 4 is a vertical cross-sectional view of the gas vent valve 400, showing the internal structure in a state where the ventilation passage is not closed. Gas vent valve 400 according to the present embodiment
Is a means for interlocking the hot water receiving piston 401 and the valve piston 402 in the same direction, and for connecting so that the moving distance until the gap 437 of the valve piston 402 is closed is longer than the moving distance of the hot water receiving piston 401, It uses a hydraulic cylinder. The vent conduit 408 is located near the center of the vent valve 400 and is located at the vent conduit end 435.
Then, it is connected to the lower through hole 403 extending in a direction perpendicular to the extending direction of the ventilation conduit 408. Lower through hole 40
3 has a hot water receiving piston 401 slidably inserted therein and is connected to a lower hydraulic cylinder 416 on the side facing the ventilation conduit 408. The ventilation conduit 408 is divided into two branch ducts (not shown) before reaching the hot water receiving piston 401. Each branch duct is connected to an upper through hole 404 that extends parallel to the extending direction of the lower through hole 403 at the upper end 406 of the branch duct. The two upper through-holes 404 are connected to an outlet 407 that communicates with the outside of the mold at the side surface. A valve piston 402 is slidably inserted in the upper through hole 404. The valve piston 402 is provided with a piston head 405 whose outer diameter is equal to or larger than the inner diameter of the upper through hole 404. When the gas vent valve 400 is not operating, a gap 437 is opened between the piston head 405 and the upper through hole 404. The two upper through-holes 404 are provided on the side facing the upper end 406 of the branch duct, respectively.
Is connected to The valve piston side hydraulic chamber 421 of the two upper hydraulic cylinders 420 and the head side hydraulic chamber 417b of the lower hydraulic cylinder 416 communicate with each other through a hydraulic passage 418. Head side hydraulic chamber 417a of the upper hydraulic cylinder 420
Oil is supplied to each of them from a hydraulic source (not shown) via a valve 419. The degassing valve 400
Since the inner structure is symmetrical with the hot water receiving piston 401 interposed therebetween, only one side will be described below.

The molten metal, which has been filled in the cavity at a high speed and reaches the final filling portion of the cavity, flows into the ventilation conduit 408. The molten metal that has reached the aeration conduit terminal portion 435 pushes and moves the hot water receiving piston 401 inserted in the lower through hole 403. As the hot water receiving piston 401 moves, the oil in the head side hydraulic chamber 417b of the lower hydraulic cylinder 416 is pushed, the oil passes through the hydraulic passage 418, and the upper hydraulic cylinder 4 moves.
It is guided to the valve piston side hydraulic chamber 421 of 20. The upper hydraulic cylinder 420 pulls the valve piston 402, moves the valve piston 402 in the same direction as the hot water receiving piston 401 by a predetermined amount, and closes a gap 437 between the piston head 405 and the upper through hole 404. At this time, the valve 419 is opened and the head side hydraulic chamber 417a of the upper hydraulic cylinder 420 is opened.
The oil flowing out of is returned to a hydraulic power source (not shown).
With the above operation, even if the force for pushing the hot water receiving piston 401 is small, the ventilation passage can be surely closed by the valve piston 402. Therefore, the ventilation conduit end portion 4
The molten metal that has reached the upper end portion 406 of the branch duct through the branch duct (not shown) from 35 does not flow out from the outlet portion 407.

In this embodiment, the hot water receiving piston 4
Although hydraulic pressure was used as the means for moving 01 and the valve piston 402, hydraulic pressure, pneumatic pressure, or the like can also be used.

The diameters of the two upper hydraulic cylinders 420 are preferably the same so that the two valve pistons 402 simultaneously close the gap 437. Further, if the radius of the lower hydraulic cylinder 416 is r and the diameter of the upper hydraulic cylinder 420 is r ', the moving distance of the valve piston 402 becomes longer than the moving distance of the hot water receiving piston 401. The following relationships must be met: √2
r ′ <r Further, the moving distance of the valve piston 402 is √2
If the difference between r'and r is large, it becomes long, and conversely, if the difference is small, it becomes short.

[Third Embodiment] A degassing valve according to a third embodiment of the present invention will be described below with reference to FIG. FIG. 5 is a vertical cross-sectional view of the gas vent valve 500, showing the internal structure in a state where the ventilation passage is not closed. Gas vent valve 500 according to the present embodiment
Is a means for interlocking the hot water receiving piston 501 and the valve piston 502 in the same direction, and connecting them so that the moving distance until the gap 537 of the valve piston 502 is closed is longer than the moving distance of the hot water receiving piston 501. It uses a rack and pinion. The vent conduit 508 is located near the center of the vent valve 500 and is located at the vent conduit end 5
At 35, it is connected to a lower through hole 503 extending in a direction perpendicular to the extending direction of the ventilation conduit 508. The hot water receiving piston 501 is slidably inserted inside the lower through hole 503, and is divided into two branch ducts (not shown) before reaching the hot water receiving piston 501. Each of the branch ducts is connected to two upper through holes 504 that extend parallel to the extending direction of the lower through hole 503 at the upper end portion 506 of the branch duct. Upper through hole 50
4, a valve piston 502 is slidably inserted. The valve piston 502 is provided with a piston head 505 whose outer diameter is equal to or larger than the inner diameter of the upper through hole 504. With the degassing valve 500 not operating,
A gap 537 is opened between the piston head 505 and the upper through hole 504. The two upper through holes 504 are connected to an outlet 507 that communicates with the outside of the mold at the side surface. A space 529 is formed inside the degassing valve 500, and two large-diameter gears 530 coaxially arranged with a small-diameter gear 525 sandwiched between the space 529 and two gears 527 located above the gears 527, respectively. It is located in mesh. Small diameter gear 525, two large diameter gears 530, and two gears 5
27 is a hot water receiving piston 501 and a valve piston 5 respectively.
Shaft 52 positioned at right angles to the axis of 02
6, is fixed to the shaft 528 in a state of being rotatable about the axis. The radius of the small diameter gear 525 is set to D1 and the radius of the large diameter gear 530 is set to D2.
(D2> D1)

The two valve pistons 502 are respectively connected to the upper rods 523 extending in the axial direction of the valve pistons 502 on the side facing the upper end 506 of the branch duct. On the lower side of the upper rod 523, rack-shaped teeth 524a are formed. The rack-shaped teeth 524 a mesh with the gear 527. The hot water receiving piston 501 is connected to the lower rod 522 extending in the axial direction of the hot water receiving piston 501 on the side facing the ventilation conduit 508. The lower rod 522 is
One end is connected to a spring 512 fixed to the inner wall 511a of the gas vent valve and is biased toward the ventilation conduit 508. A protrusion 536 is provided in the center of the lower rod 522 so that the hot water receiving piston 501 does not protrude into the ventilation conduit 508. When the gas vent valve 500 is not operating, the protrusion 536 is in contact with the gas vent valve inner wall 511b. Rack-shaped teeth 524b are formed on the upper side of the lower rod 522. Teeth 524
b is meshed with the small diameter gear 525. Since the structure inside the gas vent valve 500 is symmetrical with the small-diameter gear 525 sandwiched between them, only one side will be described below.

The molten metal that has been filled into the cavity at a high speed and has reached the final filling portion of the cavity flows into the ventilation conduit 508. The molten metal that has reached the aeration conduit end portion 535 pushes and moves the hot water receiving piston 501 inserted in the lower through hole 503. The lower rod 522 also moves integrally with the movement of the hot water receiving piston 501. The lower rod 522 rotates the small diameter gear 525 clockwise. When the small diameter gear 525 rotates, the large diameter gear 530 fixed to the shaft 526 rotates together with the small diameter gear 525 in the clockwise direction. Since the gear 527 meshing with the large diameter gear 530 rotates counterclockwise, the upper rod 523 and the valve piston 502 are
It moves in the same direction as the hot water receiving piston 501 by a predetermined amount, and a gap 537 between the piston head 505 and the upper through hole 504.
Close up.

Here, it is assumed that the small diameter gear 525 and the large diameter gear 530 rotate clockwise by an angle θ when the hot water receiving piston 501 moves leftward by L1. At this time,
The rotated circumference of the small diameter gear 525 is equal to L1,
= 2πD1 * θ / 360 °. The rotated circumferential length L2 of the large diameter gear 530 is L2 = 2πD2 * θ /
It is represented by 360 °. Further, the rotated peripheral length of the gear 527 meshing with the large diameter gear 530 is equal to L2,
Therefore, the valve piston 502 moves to the left by the circumferential length L2 of the rotation of the gear 527. Therefore, the valve piston 502
Has a movement amount increased by D2 / D1 times that of the hot water receiving piston 501. Further, the moving speed of the valve piston 502 is also increased by D2 / D1 times the moving speed of the hot water receiving piston 501.
It is also possible to adjust the moving distance and moving speed of the valve piston 502 by changing the diameter of the gear. By the above operation, even if the force to push the hot water receiving piston 501 is small, the valve piston 502 can surely close the ventilation passage. Therefore, the ventilation conduit end portion 535
The molten metal reaching the upper end portion 506 of the branch duct through the branch duct (not shown) does not flow out from the outlet portion 507.

In the first, second, and third embodiments described above, the upper through-hole is composed of two, but it is not limited to two and may be one or three or more. For example, one upper through hole may be provided, and two zoom links 210 in the first embodiment and two upper hydraulic cylinders 420 in the second embodiment, which have two holes, may be provided. Further, the large-diameter gear 530 and the gear 527 in the third embodiment may each be configured as one. The fact that the hot water receiving piston and the valve piston of the present invention interlock in the same direction means that the moving direction of the hot water receiving piston and the moving direction of the valve piston are both positive or negative with reference to the mold cross section including the ventilation conduit. It means that.

[0017]

As described in detail above, the present invention is a degassing valve for opening and closing an exhaust air passage formed in a mold with a closing member, and a pressure receiving member for receiving a dynamic pressure of molten metal, By the connecting means for interlocking the closing member that closes the ventilation passage by a predetermined amount of movement in the same direction, the moving distance of the closing member until the closing of the ventilation passage is made longer than the moving distance of the pressure receiving member. Therefore, even if the force for pressing the pressure receiving member becomes low, it is possible to close the ventilation passage by moving the valve piston by a predetermined amount.

[Brief description of drawings]

FIG. 1 is a usage state diagram of a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the first embodiment of the present invention,
It is a figure which shows an internal structure.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a diagram showing an internal structure of a second embodiment of the present invention.

FIG. 5 is a diagram showing an internal structure of a third embodiment of the present invention.

FIG. 6 shows the internal structure of a prior art die casting degassing valve with the valve piston in the closed position.

FIG. 7 is a sectional view taken along line BB in FIG. 6;

[Explanation of symbols]

201 ... Hot water receiving piston 202 ... Valve piston 210 ...
Zoom link 10 ... Gas vent valve

Claims (1)

[Claims] 1. A degassing valve for opening and closing an exhaust ventilation passage formed in a mold, comprising: a pressure receiving member that is moved by being pushed by the molten metal that has flowed into the ventilation passage; A closing member that closes the pressure receiving member and the closing member in the same direction until the ventilation passage is closed by the closing member, and a movement distance of the closing member that closes the ventilation passage is the pressure receiving member. And a connecting means for connecting the member so that the member is longer than the moving distance of the member.