JPH0749143B2 - Die casting method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die casting method for injecting a molten metal such as an aluminum alloy into a cavity of a mold which is clamped to form a cast product.

[0002]

2. Description of the Related Art Generally, in a cold chamber type die casting machine, as shown in FIG. 4, a movable mold 21 is provided to a fixed mold 20 so that the mold can be clamped and opened in the left and right directions. A plunger sleeve 23 communicating with a cavity 22 formed by clamping the two dies 20 and 21 is provided on the side, and a hot water supply port 24 is formed at an upper outer periphery of an end portion of the plunger sleeve 23. The molten metal supplied from the mouth 24 into the plunger sleeve 23 is pressed into the cavity 22 by the forward movement of the plunger 25.

[0003]

In the cold chamber type die casting machine, since the plunger sleeve 23 is oriented laterally, the molten metal supplied into the plunger sleeve 23 is moved forward by the plunger 25 to move the cavity 22 into the cavity 22. When press-fitting into the molten metal, as shown in FIG. 5, due to the pressing of the plunger 25, the molten metal is often entrained along the tip end surface thereof, and air a is often entrained in the molten metal.

In particular, when the moving speed of the plunger 25 is increased, the entrainment of air appears remarkably, and the entrainment of air causes a blow hole to be formed in the cast product.

The present invention aims to solve the above problems and to obtain a uniform cast product without blowholes.

[0006]

In order to solve the above-mentioned problems, according to the present invention, in the step of press-fitting the molten metal supplied into the plunger sleeve into the cavity by moving the plunger, the plunger is inserted into the plunger sleeve. Since the pair of molds and the plunger sleeve are tilted so that the hot water supply port becomes downward when passing through the provided hot water supply port, the structure is adopted in which the molten metal is pressed into the cavity by the movement of the plunger in the inclined state. is there.

[0007]

As described above, by inclining the pair of molds and the plunger sleeve so that the hot water supply port is downward,
The molten metal in the plunger sleeve flows to the lower inclined portion of the sleeve and is supported by the tip end surface of the plunger. Therefore, when the molten metal is pressed in by the movement of the plunger, the molten metal is not entrained along the tip end surface of the plunger, and the entrainment of air is prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a cold chamber type die casting machine, in which a base 1 is swung around a shaft 3 by the operation of a cylinder 2. A pair of mold mounting plates 4 and 5 are provided on the base 1, and the mold mounting plate 4 on the shaft 3 side is fixed to the base 1. The other mold mounting plate 5 is slidably supported along the guide rod 6 and is moved back and forth by the cylinder 7.

A fixed mold 8 and a movable mold 9 are mounted on the opposing surfaces of the pair of mold mounting plates 4 and 5. Fixed mold 8
2, one end portion of the plunger sleeve 10 is connected, and a hot water supply port 11 is provided on the outer periphery of the other end portion of the plunger sleeve 10.

The molten metal supplied from the hot water supply port 11 into the plunger sleeve 10 is moved between the molds 8 and 9 clamped from the passage 14, the runner 15 and the gate 16 by the plunger 13 which is moved back and forth by the operation of the cylinder 12. Is press-fitted into the cavity 17.

The cold chamber type die casting machine shown in the embodiment has the above-mentioned structure. When molding a cast product using the die casting machine, the base 1 is kept horizontal and the movable die 9 is clamped. After the molten metal is supplied from the hot water supply port 11 into the plunger sleeve 10, the plunger 13 is advanced to press the molten metal toward the cavity 17, and when the tip of the plunger 13 is advanced to a position where the hot water supply port 11 is closed, The cylinder 2 shown in FIG.

As shown in FIG. 3, due to the inclination of the platform 1, the molten metal flows under the inclined portion of the plunger sleeve 10 and is supported by the tip surface of the plunger 13, and an air layer is formed on the molten metal surface. Therefore, the plunger 13 does not come into contact with the air layer, the molten metal moves smoothly by the forward movement of the plunger 13, and the air is not trapped in the molten metal.

As the plunger 13 moves forward, air is first pushed into the cavity 17, and the molten metal enters the cavity 17 by pushing the air out. Therefore, it is possible to form a uniform cast product without blowholes.

After forming the cast product, the base 1 is returned to a horizontal state, the movable mold 9 is opened, and the cast product is taken out.

[0015]

As described above, according to the die casting method of the present invention, the blanker sleeve is in a horizontal state.
In order to supply molten metal from the hot water supply port,
Inside the slanted plunger sleeve with the mouth end at the bottom
Plunger sleeve compared to supplying molten metal to
A large amount of molten metal can be supplied inside, and a hot water supply port
Adopt a gravity drop supply method to supply molten metal to
This eliminates the need for a melt injection device such as a pump.
However, the cost of the molten metal supply device can be reduced.
Further, tilting the mold and the plunger sleeve at the stage of the plunger press fitting the dissolved water closes the hot water inlet, since the molten metal so as to press-fit into the cavity the molten metal in the plunger sleeve in a state supported by the plunger tip surface It is possible to prevent air from being caught in the molten metal due to the pressing of the plunger, and it is possible to form a uniform cast product without blow holes.

[Brief description of drawings]

FIG. 1 is a schematic view of a die casting machine used in the method according to the present invention.

FIG. 2 is a cross-sectional view showing a state where the mold is clamped.

FIG. 3 is a cross-sectional view showing a state in which molten metal is being press-fitted.

FIG. 4 is a sectional view showing a mold part of a conventional die casting machine.

FIG. 5 is a cross-sectional view showing a press-fit state of molten metal.

[Explanation of symbols]

 8 Fixed mold 9 Movable mold 10 Plunger sleeve 11 Hot water inlet 17 Cavity

Claims (1)

[Claims] And 1. A process for clamping a fixed mold and a movable mold, communicating with the molds of the cavity, the internal from the periphery upper delivery sprue flop <br/> run Ja sleeve is in a horizontal position In the die casting method, which comprises the step of supplying molten metal into the cavity and the step of press-fitting the molten metal in the plunger sleeve into the cavity by the forward movement of the plunger, the tip of the plunger into which the molten metal is press-fitted is at a stage where the hot water supply port is closed. A die casting method comprising inclining a die and a plunger sleeve so that an end on a hot water supply port side is downward, and injecting the molten metal into the cavity in the inclined state.