JP3415695B2 - Degassing device for mold - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas vent for a mold for reducing the pressure in a cavity by sucking air or gas in the cavity after closing the mold in die casting. Regarding the device, in detail, the gas vent valve installed in communication with the end of the gas vent groove leading to the mold cavity is configured to be closed by the action of the molten metal rising from the cavity to the gas vent groove. The present invention relates to a mold degassing device. 2. Description of the Related Art Various types of mold degassing devices have been proposed as this type of mold degassing device, and the closest to the present invention is disclosed in Japanese Patent Application Laid-Open No. Hei 6-277818. There is something. In this prior art, as shown in FIG. 6, a gas vent groove 8 is formed in a mold mating surface 6 so as to communicate with the cavities of the dies 4a and 4b. 6 and a pressure receiving piston 3 is installed in the depth direction of the gas release groove 8 in parallel with the gas release valve 2.
A push rod is provided to the urging means 12 for connecting the drive connecting plate 13 provided at the base end of the pressure-receiving piston 3 to the degassing valve 2 and for urging and pressing the drive connecting plate 13 of the pressure receiving piston 3 toward the mold matching surface 6. 19, the other end 19b of the push rod 19 is made to protrude from the mold mating surface 6, and when the mold is closed, the urging means 12 is pushed back by the push rod 19 and the gas release groove 8 is removed from the mold cavity. The depressurizing valve 2 is configured to close the gas release valve 2 via the drive connecting plate 13 by pressing the pressure receiving portion 3a of the pressure receiving piston 3 with the molten metal rising. However, the pressure receiving portion 3a of the pressure receiving piston 3 always has the cylinder portion 14
When the molten metal that has risen from the mold cavity in the gas release groove 8 presses the pressure-receiving portion 3a of the pressure-receiving piston, it forms on the outer periphery of the pressure-receiving portion 3a of the pressure-receiving piston. The resulting burrs are inserted between the pressure-receiving piston 3 and the inner peripheral surface of the cylinder portion 14, and there is a problem that malfunctions are likely to occur. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has been found to cause malfunction due to insertion of a flash between the pressure receiving piston and the inner peripheral surface of the cylinder. Therefore, it is an object of the present invention to provide a mold degassing device that does not cause a problem. According to the present invention, there is provided a degassing apparatus for a mold, wherein a gas vent groove communicating with a cavity of a mold is formed on a mold mating surface. At the end of the gas vent valve is installed in the depth direction from the mating surface, and a pressure receiving piston is installed in parallel with the gas vent valve on the way of the gas vent groove, and is provided at the base end of the pressure receiving piston. The drive connection plate is connected to the degassing valve, and the tip of the push rod is brought into contact with an urging means for urging and pressing the drive connection plate toward the mold matching surface,
The other end of the push rod protrudes from the mold mating surface, and when the mold is closed, the urging means is pushed back by the push rod, and the molten metal that has risen from the mold cavity to the gas vent groove receives the pressure of the pressure receiving piston. In the mold degassing device in which the degassing valve is closed through the drive connection plate by pressing the pressure-generating portion, an air blow passage communicating with the cylinder portion of the pressure-receiving piston is formed, The pressure receiving portion of the piston is made to be freely retractable from the cylinder portion into the gas vent groove, and one end of the push rod is made to penetrate the drive connecting plate to abut on the urging means, and one end of the push rod The drive connecting plate is formed with a contact step that is in contact with the drive connecting plate, and when the drive connecting plate is pressed by the contact step of the push rod when the mold is closed, In which the pressure receiving portion of the pressure piston is characterized in that formed as retracted into the cylinder portion. An embodiment of the present invention will be described below with reference to the drawings. This degassing device A is configured by integrally incorporating a degassing valve 2, a pressure receiving piston 3 and the like in two front and rear splittable housing blocks 1a and 1b, and molds 4a and 4b that can be opened and closed in the left-right direction. On the other hand, for example, fixed type 4
It is set in the concave portion 5 formed in the upper part of FIG. On the front surface of the front housing block 1a, that is, on the mold mating surface 6, a gas vent groove 8 communicating with the cavity 7 of the molds 4a and 4b is formed. As shown in FIG. 2, the gas vent groove 8 has a plurality of pool chambers 8.
a, 8b and a plurality of branch grooves 8c, 8d branched therefrom. That is, the pool chamber 8b is formed at a position where the molten metal rising from the mold cavity 7 acts intensively, the pressure receiving piston 3 is disposed in the pool chamber 8b, and the pool chamber 8b is formed. The molten metal which has risen from the mold cavity 7 by detouring the plurality of branch grooves 8c and 8d presses the pressure receiving piston 3 by its impact force, and the gas release valve 2 is closed via the drive connecting plate 13. The degassing valve 2 is arranged at the end 8 'where the molten metal later arrives. The gas vent valve 2 is for discharging gas, air, etc., from the mold cavity 7 through the gas vent groove 8 to the outside. The valve block 2 is installed slidably in the axial direction in a valve cylinder portion 9 formed in a horizontal direction over the housing block 1b, and the valve head 2a is made freely retractable from the valve cylinder portion 9 into the gas vent groove 8.
The valve operation is performed by the valve head 2a protruding and retracting into the gas vent groove 8 to open and close the valve port 9a of the valve cylinder portion 9. The valve cylinder section 9 of the gas release valve 2 includes:
The exhaust passage 10 and the air blow passage 11 communicating with the outside are connected to each other, and the exhaust passage 10 is connected to an exhaust hose connected to a vacuum device (not shown) to release gas from the mold cavity 7. The gas or air that has passed through the groove 8 is discharged to the outside, and an air hose (not shown) is connected to the air blow passage 11 so that the valve head 2a of the gas release valve 2 is connected. When the valve port 9a of the valve cylinder portion 9 is opened by protruding into the gas vent groove 8, air is blown from the inner peripheral surface of the valve cylinder portion 9 or the outer periphery of the valve head 2a of the gas vent valve 2. Further, the pressure receiving piston 3 is driven by the action of the urging means 12 for urging and pressing the molten metal m rising from the mold cavity 7 through the gas release groove 8 toward the mold mating surface 6. This is for operating the degassing valve 2 via the connecting plate 13, and is installed in parallel and parallel with the degassing valve 2.
That is, an opening is formed in the cylinder portion 14 in the horizontal direction in parallel with the valve cylinder portion 9 of the degassing valve 2 from the mating surface 6 of the front housing block 1a to the rear housing block 1b. The pressure receiving piston 3 is installed so as to be slidable in the axial direction, and the pressure receiving portion 3a is made to be able to come and go into the gas vent groove 8 from inside the cylinder portion 14. An air blow passage 15 is formed in communication with the cylinder portion 14 of the pressure receiving piston 3, and an air hose is connected to the air blow passage 15 so that the pressure receiving portion 3a of the pressure receiving piston 3 can release gas. When the cylinder part 14 is opened by projecting into the groove 8, air is blown from the inner peripheral surface of the cylinder part 14 or the outer periphery of the pressure receiving part 3 a of the pressure receiving piston 3. A drive connection plate 13 for connecting the pressure receiving piston 3 and the gas release valve 2 is provided at the base end of the pressure receiving piston 3. In the illustrated embodiment, the drive connection plate 13 is formed in the same body as the pressure receiving piston 3, and the gas vent valve 2 and the guide piston 16 are integrally connected to the periphery thereof, and the drive connection plate 13 is formed on the rear side. The urging means 12 for urging and pressing the mating surface 6 is brought into contact. The urging means 12 has a spring 17 for lightly pressing the drive connecting plate 13 toward the mold mating surface 6 in the cylindrical portion 12a, and a driving connecting plate 1 at the tip of the cylindrical portion 12a.
A spring 18 having a strong elastic force such as a disc spring is disposed on the back side of the flange portion 12b formed to have a slightly smaller diameter than the outer diameter of the flange portion 3, and the urging means 12 is provided on the front side of the flange portion 12b. The push rod 19 for pushing back is contacted. The spring 17 keeps the gas release valve 2 open until the molten metal rising from the mold cavity 7 through the gas release groove 8 presses the pressure receiving portion 3 a of the pressure receiving piston 3. When the molten metal presses the pressure receiving portion 3a of the pressure receiving piston 3, the spring force is set to be weak enough to be easily pushed back, and the spring 18 is used for the molten metal solidified in the gas vent groove 8, that is, the pressure receiving portion 3a of the pressure receiving piston 3. The spring force is set to be strong enough to allow the molten metal pressed to extrude the solidified solidified in the gas release groove 8. The push rod 19 is for pushing the extruder 12 back to the rear side through the closing force of the dies 4a and 4b, and one end 19a of the push rod 19 is connected to the extruder 12 by a drive connecting plate of the pressure receiving piston 3. 13 and penetrate it,
The other end 19b protrudes from the mold-matching surface 6, and a contact step portion 20 is formed at one end side to be in contact with the drive connecting plate 13 of the pressure receiving piston 3. The contact step 20 does not abut against the drive connecting plate 13 before the mold closing operation of the molds 4a and 4b, but presses the drive connecting plate 13 when the mold is closed to receive the pressure of the pressure receiving piston 3. The portion 3 a is set and formed so as to be immersed in the cylinder portion 14. That is, during the closing operation of the dies 4a and 4b, the pressure receiving portion 3a of the pressure receiving piston 3 projects into the gas vent groove 8 until immediately before the push rod 19 is immersed from the die mating surface 6. The pressure receiving portion 3 a of the pressure receiving piston 3 is set and formed so as to be immersed in the cylinder portion 14 when the drive connecting plate 13 is pressed to the rear side by the portion 20. In FIG. 1, the push rod 19 is arranged at an intermediate position between the gas release valve 2 and the pressure receiving piston 3, but this is for facilitating the understanding of the present invention. As shown in FIG. 2, the pressure receiving piston 3, the drive connecting plate 13, the gas vent valve 2, and the like are located on the left and right sides of the pressure receiving piston 3 so as to be able to be pushed back with good balance. The operation of the thus-configured mold degassing apparatus will be described. FIG. 1 shows the molds 4a and 4b.
Is opened, the gas release valve 2 is in the valve open state, and the pressure receiving portion 3 a of the pressure receiving piston 3 is in the expected state protruding into the gas release groove 8. In this state, compressed air is supplied to the air blow passage 11 of the degassing valve 2 to air blow the inner peripheral surface of the valve cylinder portion 9 of the degassing valve 2 or the outer circumference of the valve head 2a of the degassing valve 2 and receive pressure. The compressed air is supplied to the air blow passage 15 of the piston 3 to blow air from the inner peripheral surface of the cylinder portion 14 of the pressure receiving piston 3 to the outer periphery of the pressure receiving portion 3a of the pressure receiving piston 3. Next, when the mold closing operation of the molds 4a and 4b is started, the mold (movable mold) 4b contacts the other end 19b of the push rod 19 as shown in FIG. Is pressed from the mold-matching surface 6 in the depth direction. Then, as the closing operation of the dies 4a and 4b proceeds,
At one end 19a of the push rod 19, the urging means 12 is pushed back to the rear side against the force of the spring 18, and the contact step 20 of the push rod 19 abuts and engages with the drive connecting plate 13. The drive connecting plate 13 is pushed back to the rear side. When the closing operation of the dies 4a and 4b is completed, the push rod 19 is immersed in the front housing block 1a as shown in FIG. The movement is restricted by the spring 20 and the spring 17, the pressure receiving part 3 a of the pressure receiving piston 3 is immersed in the cylinder part 14, and the valve head 2 a of the vent valve is located near the valve port 9 a of the valve cylinder part 9. And the valve is kept in the open state. In this state, when the molten metal is injected and filled into the mold cavity 7, the gas and air in the mold cavity 7 pass from the gas vent groove 8 through the valve port 9 a of the gas vent valve 2 to the valve cylinder part 9. The exhaust gas is discharged to the outside through the exhaust passage 10 which is in communication. On the other hand, a part of the molten metal m rises in the gas release groove 8 and hits the pressure receiving portion 3a of the pressure receiving piston 3 so that the driving force is applied to the drive connecting plate 13 as shown in FIG.
The valve head 2a of the degassing valve is immersed into the valve cylinder portion 9 to be pressed against the rear side against the force of
The closed state of a is maintained. At this time, the molten metal m in which the pressure receiving piston 3 is retracted reaches the gas vent groove 8 'in which the gas vent valve 2 in the closed state is located. When the molten metal in the mold cavity 7 is cooled for a predetermined time and solidified, the molten metal in the gas vent groove 8 is also solidified. Therefore, when the mold cavities 4a and 4b are subsequently opened, the push rod 19 is opened. Then, the push rod 19 and the drive connecting plate 13 are pushed back toward the mold matching surface 6 again by the force of the spring 18 via the urging means 12. Then, the gas release valve 2 projects into the gas release groove 8 and returns to the valve open state, and the pressure receiving portion 3a of the pressure receiving piston 3 also projects into the gas release groove 8 and returns to the original state, that is, the state of FIG. I do. Hereinafter, the above operation is repeated. As described above, the degassing apparatus for a mold according to the present invention is constructed in such a manner. For each casting cycle, the pressure receiving piston is projected into the gas releasing groove so that the inner peripheral surface of the cylinder portion or the pressure receiving piston can be removed. It becomes possible to air blow the outer periphery of the pressure receiving portion. Therefore, even if burrs occur on the outer periphery of the pressure receiving portion of the pressure receiving piston when the molten metal rising from the mold cavity in the gas release groove presses the pressure receiving piston, the burrs are air blown every casting cycle. As a result, there is no danger that the burrs may be inserted between the pressure receiving piston and the inner peripheral surface of the cylinder and cause malfunction, and the gas releasing operation may be stable for a long period of time. Can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an embodiment of the present invention, showing a desired state in which a mold is opened. FIG. 2 is a front view of FIG. 1; FIG. 3 is a cross-sectional view similar to FIG. 1, showing a mold closing progress state. FIG. 4 is a sectional view similar to FIG. 1, showing a state in which mold closing is completed. FIG. 5 is a cross-sectional view similar to FIG. 1, showing a state in which the molten metal has risen through the gas vent groove. FIG. 6 is a cross-sectional view showing a conventional example, showing an expected state in which the mold is opened. [Explanation of Signs] 2: Gas release valve 2a: Valve head 3: Pressure receiving piston 3a: Pressure receiving portion 4a, 4b: Mold 6: Mold matching surface 7: Cavity 8: Gas release groove 12: Energizing means 13: Drive connection Plate 14: Cylinder part 15: Air blow passage 19: Push rod

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B22D 17/22 B29C 45/34 B22C 9/06

Claims (1)

(57) [Claims 1] A gas vent groove communicating with a cavity of a mold is formed on a mold mating surface, and a gas vent valve is provided at a terminal end of the gas vent groove from the mold mating surface in a depth direction. While installing
On the way to the gas vent groove, a pressure receiving piston is installed in parallel with the gas vent valve, a drive connecting plate provided at the base end of the pressure receiving piston is connected to the gas vent valve, and the drive connecting plate is The tip of the push rod is brought into contact with the urging means for urging and pressing toward the mold mating surface, and the other end of the push rod is projected from the mold mating surface. A mold in which the molten metal that has risen from the mold cavity to the gas vent groove from the mold cavity presses the pressure-receiving portion of the pressure-receiving piston, thereby closing the gas vent valve via the drive connection plate. In the gas venting device, an air blow passage communicating with the cylinder portion of the pressure receiving piston is formed, and the pressure receiving portion of the pressure receiving piston is made to be able to protrude and retract from the cylinder portion into the gas vent groove. One end of the push rod is made to penetrate the drive connecting plate and abut on the urging means, and at one end side of the push rod, a contact step is formed to be in abutting engagement with the drive connecting plate. A degassing device for a mold, wherein the pressure receiving portion of the pressure receiving piston is immersed in the cylinder portion when the drive connecting plate is pressed by the contact step portion of the push rod.