JPS5835789B2 - Structure of gas venting part of casting mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present application mainly relates to the structure of a gas venting part of a casting mold used for die casting.

It has been known to provide a gas vent that communicates with the cavity f for discharging the air inside the mold when molten metal is press-fitted in casting operations. Gas venting is performed by creating a gap approximately 100-degree thick.

The reason why it cannot be made larger is that when the molten metal comes into contact with the mold surface, the contact surface instantly becomes semi-solid and the viscosity increases, resulting in an instant laminar flow and the mold contact surface solidifies into a thin solidified film. In addition, as the center of the tip of the molten metal advances at high speed, the pressure decreases and the contact between the mold and the solidified film layer becomes a single contact state, making it difficult to conduct heat efficiently.
It was not possible to make the gap thicker because the molten metal in the center moved forward while being kept warm and spouted out of the mold.

The present invention solves this problem, and even if the cross-sectional area of the degassing part is made sufficiently large, there is no concern that the molten metal will jump out, and any part can perform structurally stable and safe degassing and solidification. It was invented for the purpose of providing a casting mold that can be used.

Referring to the drawings showing an example of the embodiment, 1 is a movable mold, and 2 is a fixed mold provided opposite to the movable mold.

3 is a cavity provided in the movable mold 1 and the fixed mold 2 in a concave shape.

Reference numeral 4 denotes a gas venting section formed by providing a gap between the mating surfaces of the movable mold 1 and the fixed mold 2, and one end on the internal force side communicates with the cavity 3.

5, 5... are on the inner surface of the movable mold 1, one end of the inner side communicates with the gas venting part 4, and the other end of the outer side is inclined in an oblique direction (approximately 5° to 85'). At the very least, it is a gas venting inclined groove formed in a groove shape.

6, 6... are on the inner surface of the fixed mold 2, one end of the inner side communicates with the gas venting part 4, and the other one end of the outer side faces the gas venting inclined grooves 5, 5, Moreover, it is a gas venting inclined groove formed in a groove shape and inclined (approximately 5° to 85°) in the direction of the opposite force.

7 is a safety cavity bored on the exit side of the gas venting inclined groove 5.

8 is a vacuum pump communication hole communicating with one end of the safety cavity 7.

9 is the entrance side of the cavity 3 (this is the runner drilled here).

Because of this configuration, when the present invention is carried out, the molten metal press-fitted by a cylinder (not shown) enters the cavity 3 through the runner 9, then diagonally intersects and enters the opposing gas venting grooves 5 and 6. However, in this case, while the molten metal that has plunged into the gas vent slope structures 5 and 6 respectively advances toward the exit side, their inner surfaces cross and collide with each other many times, and the collision portion advances. diagonally across each other in the direction of
As the molten metal advances in the torsional direction, the molten metal is stirred at each intersection, preventing laminar flow and mutually suppressing the thrusting forces, thus preventing the molten metal from laminar flow (due to contact with the mold). Eliminating the extreme cooling difference between the surface and the inside, coupled with the effect of mutually suppressing the thrusting force, prevents unexpected situations such as some semi-solidified parts breaking and molten metal spilling out, and a considerably wide cross-sectional area. This invention has the effect of ensuring uniform, safe and reliable solidification of the molten metal over the entire surface of the gas venting part of the cavity, and allowing sufficient gas venting in the cavity with a simple structure.

The present invention has a wide range of applications and can be applied to molds for synthetic resins.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an embodiment of the main part of the present invention. FIG. 2 is a perspective view showing the movable mold side. FIG. 3 is a longitudinal sectional view. FIG. 4 is a partially cutaway perspective view showing the intersecting state of the molten metal after solidification. DESCRIPTION OF SYMBOLS 1... Movable mold, 2... Fixed mold, 3... Cavity, 4... Gas venting part, 5... Gas venting inclined groove,
6... Gas vent inclined groove, 7... Safety cavity, 8...
Vacuum pump communication hole, 9... runner.

Claims (1)

[Claims] 1. On the inner surface of the movable mold, one end side communicates with the cavity side, and the other end side is inclined diagonally and communicates with the outer safety cavity.Many gas vent grooves are bored in the inner surface of the movable mold, and the opposing fixed mold The inner surface (opposed to the gas venting inclined groove, one end side communicating with the cavity side, and the other end side being inclined in the opposite direction so as to intersect the said gas venting inclined groove at multiple points in an oblique direction) A structure of a gas venting part of a casting mold, characterized by having a large number of opposing gas venting inclined grooves communicating with an outer safety cavity.