JPH06238416A - Method for casting magnesium alloy - Google Patents

Abstract

PURPOSE:To eliminate the need for supplying inert gas to molten magnesium at each shot or at all the time, to avoid the risk of firing due to a parting agent for die and a lubricant for plunger and to eliminate the need to use such an auxiliary tool as a cover. CONSTITUTION:In a casting method in a die casting machine for magnesium alloy in which the molten metal is supplied into an injection sleeve 8 inserted with an injection plunger 22 in freely movable back and forth with an electromagnetic pump 14 through a molten metal feeding hole 10 and injected into a cavity 9 in the die with the plunger 22, the molten metal feeding hole 10 for the injection sleeve 8 is plugged with the injection plunger 22 except the time when the molten metal is supplied at the time of casting during casting process.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for casting a magnesium alloy.

[0002]

2. Description of the Related Art In a conventional die casting machine for magnesium alloy, a vertical die casting machine 40 shown in FIG.
In the case of, after moving the mold, the movable mold 41 is moved to the upper part with respect to the fixed mold 42, and then attached to a take-out device (not shown),
The pipe 47 that discharges the inert gas moves to the opening of the injection sleeve 43 that is fitted in the center of the fixed mold 42. Inert gas from the pipe 47 through the injection sleeve 43,
For example, SF6 is discharged onto the molten magnesium alloy molten metal 46 in the molten metal distribution pipe 45 penetrating the side end of the injection sleeve 43 to prevent the molten molten metal 46 from contacting the air.

In the case of the horizontal die casting machine 50 shown in FIG. 9, a fixed die plate 51 and a cover 56 which covers the injection sleeve 52 fitted therein and which holds the inert gas therein, and the inside of the cover 56 are covered with an inert gas. A pipe 57 for introducing active gas is provided. A hole 53 for passing an inert gas is provided at an upper end portion of the injection sleeve 52, and the inert gas is filled with the pipe 57, the cover 56, and the hole 53.
Through which the molten metal 5 is constantly discharged onto the molten magnesium alloy 55 in the hot water distribution pipe 54 opening to the injection sleeve 52.
5 prevents contact with air.

[0004]

However, replenishment of the inert gas at all times requires a great deal of expense and labor, and there is a risk of ignition when the mold release agent or the plunger lubricant contacts the molten magnesium. For this reason, a great deal of attention must be paid also to this, and in addition, the above-mentioned auxiliary equipment such as the cover is necessary to prevent the diffusion of the inert gas.

According to the present invention, it is not necessary to replenish the molten magnesium with the inert gas every shot and at all times, there is no danger of ignition due to the mold release agent or the plunger lubricant, and auxiliary tools such as a cover are required. It is an object of the present invention to provide a magnesium alloy casting method that does not include

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention uses an electromagnetic pump to supply molten metal into an injection sleeve into which an injection plunger is inserted so that the injection plunger can advance and retreat through a hot water supply port. According to the method of casting a magnesium alloy die casting machine for injecting into a mold cavity, the hot water supply port to the injection sleeve is closed by the injection plunger except during hot water supply during casting during the casting process. The alloy casting method was used.

[0007]

The hot water supply port to the injection sleeve is closed by an injection plunger inserted into the injection sleeve except during hot water supply during casting.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1 by taking a vertical injection die casting machine as an example. Reference numeral 1 denotes a die clamping machine of a die casting machine, which includes a fixed die 2 and a movable die 3 which are laterally clamped. The fixed die 2 is fixed to a fixed die plate 4 and the movable die 3 is Each is attached to the moving die plate 5.

One end of the injection sleeve 8 is fitted and fixed to the split surface between the fixed mold 2 and the movable mold 3, and the other end projects downward. The injection sleeve 8 may be of a one-piece type or of a two-piece type. In the case of the one-piece type, it is attached to the fixed die 2, and in the case of two pieces, one is attached to the fixed die 2 and the other is attached to the movable die 3. In this example, a split sleeve was used. In addition, an injection plunger 22 is provided in the injection sleeve 8 so as to be capable of advancing and retracting so as to inject the molten metal into a cavity 9 formed between the fixed mold 2 and the moving mold 3.

A hot water supply port 10 is opened in the injection sleeve 8 at a position above the upper end of the injection plunger 22 at the lower limit of movement, and a hot water supply pipe 11 connected to the hot water supply port 10 extends downward. The molten metal in the molten metal holding furnace 20 is communicated with the external molten metal holding furnace 20 through a horizontal molten metal supply pipe 13, and the molten metal in the molten metal holding furnace 20 is supplied into the injection sleeve 8 by the electromagnetic pump 14.

The molten metal 21 in the molten metal holding furnace 20 has its liquid level constantly maintained by automatic adjustment, and its height is set at an intermediate position of the vertical hot water supply pipe 12, and the hot water supply pipe 13 or 12 The molten metal 21 of the molten metal holding furnace 20
Is naturally flowing. A heater 23 is installed so as to surround the hot water supply pipes 12 and 13, and the molten metal 21 in the hot water supply pipes 12 and 13 can be heated by the heater 23 and held in a molten state.

In this embodiment thus constructed, the casting operation is carried out in the following procedure. First, in a standby state, the fixed mold 2 and the movable mold 3 are clamped, and the molten magnesium alloy melt 21 from the molten metal holding furnace 20 is introduced from the hot water supply pipe 13 to a midpoint of the hot water supply pipe 12, and is heated by the heater 23. It is kept molten (Fig. 1).

Next, as a hot water supply step, the injection plunger 2
2 is lowered to the lower limit position, the hot water supply port 10 is released from the injection plunger 22, and then the electromagnetic pump 14 is operated for a preset hot water supply time.
1 is transferred in the forward direction. As a result, the molten metal 21 sequentially replenished from the molten metal holding furnace 20 flows into the molten metal supply pipes 13 to 11 and the injection sleeve 8 (FIG. 2).

Subsequently, as an injection step, the injection plunger 22 is operated for a preset injection time, moved from the lower limit position to the upper limit position, and the molten metal measured in the injection sleeve 8 is injected into the cavity 9 and is injected. The plunger 22 closes the hot water supply port 10. In addition, until the product removal process and the standby state that should be prepared for the next molding operation,
The position of the injection plunger 22 in the injection sleeve 8 is a position where the hot water supply port 10 is closed (FIG. 3).

Next, as a pressure-holding step, the electromagnetic pump 14 is de-excited and the molten metal remaining in the hot water supply pipe 11 is caused to flow backward by its own weight, or the electromagnetic pump 14 is transferred in the opposite direction. As a result, the liquid level of the molten metal 21 is held at the intermediate position of the hot water supply pipe 12 (FIG. 4).

After these operations, as a mold opening process of the fixed mold 2 and the movable mold 3, the injection plunger 22 is slightly lowered to separate from the die cast product 17, but the position of the injection plunger 22 is changed. It remains at the position where the hot water supply port 10 is closed. Next, when the movable mold 3 is moved to the left in the figure, the die-cast product 17 molded in the cavity 9 and one of the injection sleeve 8 are separated from the fixed mold 2 while being fixed to the movable mold 3 together. (FIG. 5) (FIG. 6).

Next, as a product take-out step, the die-cast product 17 is pushed out by a push-out pin and a product take-out device (not shown) and taken out of the die-casting machine 1 (FIG. 7).

When the work from the hot water supply process to the product removal process is completed, the die casting machine 1 returns to the standby state in preparation for the next molding operation (FIG. 1).

As described above, according to this embodiment,
From the injection stroke to the final product removal stroke, and during the standby state to prepare for the next molding operation, the injection plunger 22
By setting the position of the injection sleeve 8 in the injection sleeve 8 so as to close the hot water supply port 10, the molten magnesium alloy and air, the release agent used during the mold opening process of the fixed mold 2 and the moving mold 3,
And there is almost no contact with the plunger lubricant between the injection sleeve 8 and the injection plunger 22 used during the injection stroke.

For this reason, it is not necessary to replenish the inert gas onto the molten magnesium alloy, which reacts strongly with air, and there is no danger of ignition due to contact between the mold release agent or the plunger lubricant and the molten metal. Further, there is no need for auxiliary equipment such as a cover for holding the inert gas.

The present invention is not limited to the above-described embodiment, and in particular, an electromagnetic pump was used for hot water supply, but a hot water supply system using a plunger or vacuum may be used regardless of this.

[0022]

As described above, according to the present invention,
It is not necessary to supply an inert gas to the molten metal every shot and constantly, there is no risk of ignition, and a magnesium alloy casting method that does not require auxiliary tools such as a cover can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the operation of the embodiment.

FIG. 2 is a sectional view showing the operation of the embodiment.

FIG. 3 is a cross-sectional view showing the operation of the embodiment.

FIG. 4 is a sectional view showing the operation of the embodiment.

FIG. 5 is a cross-sectional view showing the operation of the embodiment.

FIG. 6 is a cross-sectional view showing the operation of the embodiment.

FIG. 7 is a cross-sectional view showing the operation of the embodiment.

FIG. 8 is a schematic cross-sectional view showing a conventional example.

FIG. 9 is a schematic cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Die Casting Machine 2 Fixed Die 3 Moving Die 8 Injection Sleeve 9 Cavity 10 Hot Water Supply Port 14 Electromagnetic Pump 17 Die Casting Product 20 Melt Holding Furnace 21 Molten Metal 22 Injection Plunger 23 Heater

Claims (1)

[Claims] 1. A casting of a magnesium alloy die casting machine in which a molten metal is supplied by an electromagnetic pump into an injection sleeve in which an injection plunger is inserted and retracted through a hot water supply port, and is injected into a mold cavity by the injection plunger. In the method, a magnesium alloy casting method is characterized in that a hot water supply port to the injection sleeve is closed by the injection plunger except during hot water supply during casting during a casting process.