JP5881028B1 - Gas vent valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: A general problem of die casting is that molten metal blows out from an exhaust passage of a mold at the time of injection. If the exhaust passage is throttled to prevent the molten metal from being blown out, the exhaust becomes insufficient, and not only bubbles are generated inside the molded product, but also the quality is adversely affected. The present invention is to provide a gas vent valve that is excellent in exhausting a gas body and that reliably blocks molten metal flowing into the exhaust passage. When a molten metal collides with a side surface near the tip of a rectangular-shaped valve body that swings via a pin shaft, the valve body starts to rotate around the pin shaft by the pressure and inertia force of the molten metal. The valve body side opposite to the molten metal pressure receiving surface is in contact with the exhaust hole facing by rotation activation, and the exhaust hole is closed before the molten metal enters the exhaust hole to prevent the molten metal from flowing into the exhaust hole. is there. [Selection] Figure 1

Description

Detailed Description of the Invention

  The present invention relates to a structure for blocking the flow of a molten metal flowing in an exhaust passage of a mold by a degassing valve that prevents the molten metal from blowing out in the exhaust passage of the die casting mold.

JP 2003-126952 JP 2008-296228 A

A universal problem of dies in die casting is that the molten metal flowing into the exhaust passage is blown out of the mold before it solidifies. The molten metal at the time of injection flows turbulently at high speed, high pressure, and high viscosity. In addition, when the chill vent is used to prevent the blowout, the chill vent is installed at the upper end of the mold in order to lower the molten metal temperature. With the widespread use of the vacuum evacuation method, the molten metal shut-off valve that prevents the melt from flowing into the vacuum passage is also large and installed at the upper end of the mold, so the form of the exhaust passage leading to the shut-off valve is also greatly different from that of the chill vent In other words, it is inevitable that the mold will be long.
The present invention has been made in view of the problems of the prior art as described above, and since the valve body is operated by the inertial force of the molten metal and reacts sensitively to the flow speed of the molten metal, The overall shape of the degassing valve is thin, and a degassing valve is provided that can be embedded in the vicinity of the cavity without significantly affecting the thickness and rigidity of the template.

  The degassing valve of the present application has a rectangular parallelepiped shape in which two flat plates are stacked, and is embedded in the dividing surface of the mold without being uneven. A hollow body is formed by hollowing out a substantially central portion of the upper plate of the degassing valve, and a pin shaft is inserted into one end of a rectangular-shaped valve body that swings through the pin shaft, and is attached to the lower plate. The upper surface of the metal plate swings in parallel with the mold dividing surface while maintaining a minute gap with the mold dividing surface, and the gas passage and the molten metal fluid passage are formed along the valve body in the cavity cut out from the upper plate. The gate groove that is formed and communicated with the exhaust passage of the mold is formed on the upper surface of the upper plate toward the side surface near the tip of the valve body, and the exhaust hole is formed in the inner peripheral wall of the portion facing the gate groove with the valve body interposed therebetween. To form a series of fluid passages in the vent valve.

  In the two-layer structure in which two flat plates of the degassing valve of the present application are stacked, the material of the lower plate uses a material having higher thermal conductivity than the material of the upper plate, and promotes cooling and solidification of the residual molten metal in the fluid passage. To do. Further, since the gas vent valve has a thin structure, it can be embedded in a position close to the cavity.

  The valve body of the gas vent valve of the present application is a rectangular body, and one side surface near the tip in the direction opposite to the pin shaft side is used as a pressure receiving surface on which the molten metal collides, and the opposite side surface is used as a blocking surface for sealing the exhaust hole. Both sides of the body function. As a result, the pressure of the molten metal and the blockage of the exhaust hole can be the same, and when the molten metal collides with the pressure receiving surface, the valve body starts rotating around the pin shaft, and the closed surface on the opposite side of the pressure receiving surface has the same rotation path In contact with the exhaust hole of the inner peripheral wall that faces, the closed surface of the valve body is closed.

  The shape of the front end surface of the valve body described above is a range in which the inner peripheral wall surface of the upper plate that faces the front end surface of the valve body also forms a curved surface by a circular arc with a pin shaft as a center, and the valve body swings. Is formed by a curved surface that follows the arc of the distal end surface of the valve body, and maintains a slight gap from the distal end surface of the valve body.

  When the pin shaft is inserted into the valve body and attached to the lower plate, an elastic member is attached to the lower plate and the valve body by being entangled with the pin shaft, and a restoring force is applied to the valve body. When the valve body becomes unloaded, the tip of the valve body automatically returns to the starting point due to the repulsive force of the elastic member. Further, when the gas vent valve is used for evacuation, it is possible to prevent the valve body from being adsorbed to the exhaust hole by vacuum suction by the repulsive force of the elastic member.

  In the degassing valve described above, the molten metal pressure and the exhaust hole are closed by the same behavior of the valve body, so there is no time difference between the molten metal pressure and the exhaust hole.

Gas vent valve top view A figure in which molten metal flows into the gas vent valve, collides with the pressure receiving surface of the valve body, and the closed surface on the opposite side of the valve body blocks the exhaust hole BB sectional drawing of FIG. The figure which mounted | wore the valve body and the pore of a lower board with the wire which has elasticity. Moreover, the figure which piled up the upper board and the lower board is shown. AA cross section of the vent valve A reference drawing in which a plurality of degassing valves are arranged in the vicinity of the mold cavity.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a plan view of a gas vent valve 1 and an upper plate 1a. A substantially central portion of the upper plate 1a is cut out, a pin shaft 3 is inserted into one end of the valve body 2, and the valve body 2 is mounted on the lower plate 1b. A fluid passage 7 for the gas body and the molten metal is formed along the valve body 2. When the molten metal flowing into the mold exhaust passage 10 collides with the pressure receiving surface 2a near the tip of the valve element 2 through the gate groove 4 formed on the upper surface of the upper plate 1a, the valve element is caused by the flow inertia force of the molten metal. 2 starts rotating the pin shaft 3 around the center. Due to this behavior, the blocking surface 2b opposite to the pressure receiving surface 2a is in contact with the inner peripheral wall where the exhaust hole 5 is opened and closes the exhaust hole 5. Since there is no time difference from the pressure of the molten metal to the closing of the exhaust hole 5, the molten metal cannot flow into the exhaust hole. Further, the distal end surface 2c of the valve body 2 forms a curved surface by a circular arc with the pin shaft 3 as a center, and a curved surface of a part of the inner peripheral wall cut out of the upper plate 1a facing the distal end surface 2c Following the curved surface of the tip surface 2c in the swing range of 2c, a minute gap is maintained from the tip surface to prevent the molten metal from entering.

  FIG. 2 shows a state where the molten metal flows into the gas vent valve 1 and collides with the valve body 2, the valve body 2 swings to close the exhaust hole 5, and the molten metal flows into the fluid passage 7.

  FIG. 3 is a cross-sectional view of the degassing valve 1 taken along the line B-B. Further, the elastic member 8 is entangled with the pin shaft 3 and inserted into the pores of the lower plate 1b and the valve body 2, and the molten metal cooled and solidified in the fluid passage 7 is removed when the mold is opened and the valve body is removed. When no load is applied, the valve body 2 returns to the starting point by the repulsive force of the elastic member 8. Further, when the gas body in the mold is evacuated by the vacuum suction force, an event in which the closing surface 2b of the valve body 2 is adsorbed by the exhaust hole 5 by the vacuum suction force can be prevented.

  FIG. 4 is a cross-sectional view of the degassing valve 1 taken along the line AA, showing the configuration of the degassing valve 1 in which the upper plate 1a and the lower plate 1b are overlapped. The molten metal flows into the fluid passage 7 formed between the side surface of the valve body 2 and the upper plate 1a. In order to promote the cooling and solidification of the molten metal, the lower plate 1b is made of a material having a higher thermal conductivity than the upper plate 1a, and a cooling circuit is formed in the lower plate 1b by making a hole through which a cooling medium passes for removing heat. It doesn't matter. The exhaust hole 5 and the exhaust circuit 6 are illustrated, and the form of the gate groove 4 that is an inlet for the gas body and the molten metal is illustrated.

  FIG. 5 shows an example in which a plurality of the gas vent valves 1 are arranged on the mold dividing surface 11. The degassing valve 1 that reliably blocks the flow of turbulent molten metal at high speed and pressure can have a short exhaust passage 10 and can be embedded in a position close to the cavity due to its compact and thin shape. It is. When the vacuum pipe 13 is connected to the exhaust passage 10a, vacuum evacuation can also be performed.

DESCRIPTION OF SYMBOLS 1 Gas vent valve 1a Upper plate 1b Lower plate 2 Valve body 2a Pressure receiving surface 2b Closed surface 2c End surface 3 Pin shaft 4 Gate groove 5 Exhaust hole 7 Fluid passage 8 of gas body and molten metal Elastic member 9 Stop plug 10 Exhaust passage 10a Exhaust Passage 11 Mold dividing surface 12 Cavity 13 Vacuum piping

Claims (3)

  A degassing valve in which the left and right side surfaces of a rectangular shaped valve body that swings in parallel with the mold dividing surface via a pin shaft function, and one of both side surfaces of the valve body tip is used as a pressure receiving surface for the molten metal, When the opposite side surface functions as a blocking surface that closes the exhaust hole, when the molten metal flows into the gas vent valve and collides with the valve body pressure receiving surface, the valve body starts to rotate around the pin shaft with the inertia force of the molten metal, At the same time, the degassing valve is characterized in that the closed surface opposite to the pressure receiving surface is in contact with the wall surface where the exhaust hole opens to close the exhaust hole and prevent the molten metal from flowing into the exhaust hole.   The main structure of the degassing valve for storing and mounting the valve body according to claim 1 is a two-layer structure in which two flat plates are overlapped, and the upper plate has a hollow for storing the valve body in a substantially central portion. The lower plate in contact with the upper plate is made of a material having higher thermal conductivity than the upper plate, and is formed on the upper plate in such a manner that a pin shaft is inserted into one end of the valve body and the valve body is attached to the lower plate. The fluid passage for the gas body and the molten metal is formed in a substantially U shape while maintaining an appropriate space between the inner peripheral wall of the hollow and the valve body mounted on the lower plate, and the exhaust passage of the mold is formed on the upper surface of the upper plate. The gate groove communicating with the valve body is shaped toward the pressure receiving surface of the valve body and is conducted to the fluid passage, and an exhaust hole is formed in the inner peripheral wall of the cavity facing the closing surface of the valve body at the end of the fluid passage A vent valve comprising a series of fluid passages in the vent valve.   The tip surface shape of the valve body according to claim 1 is a curved surface formed by a circular arc with a pin shaft as a center, and a part of the inner peripheral wall of the upper plate that faces the valve body tip surface is also hollowed out. In the swinging range of the valve body, it is formed with a curved surface that follows the arc of the valve body tip surface, keeps a slight gap from the tip surface of the valve body, entangles an elastic member between the lower plate, the valve body, and the pin shaft, When no load is applied, the valve body automatically returns to the starting point by the repulsive force of the elastic member, and the repelling force of the elastic member prevents the closed surface of the valve body from being adsorbed by the exhaust hole when the gas body is evacuated. Degassing valve with function.

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