JP3145502B2 - Die casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a die casting apparatus in which when a molten metal is injected into a cavity, air in the cavity is simultaneously evacuated.

[0002]

2. Description of the Related Art Conventionally, in a die casting apparatus in which a molten metal is injected into a mold cavity to form a product, in order to improve molding quality by eliminating defects such as air biting, the air in the cavity is injected prior to injection. A device for degassing gas generated at the time of pouring and pouring is known. For example, Japanese Patent Application Laid-Open No. 3-8547 has been proposed as an improvement of such a device. When air in the cavity is sucked, external air is drawn into the cavity from the gap between the mating surfaces of the dies, and the casting is performed. In order to prevent a problem that blowholes or the like are generated in the product, the air that is going to flow into the cavity is released to the outside before reaching the cavity or the like.

[0003]

However, conventional devices including the above-described devices generally use a suction device such as a vacuum pump to suction air in the cavity, and the configuration of the entire device is complicated. And tended to be expensive.

[0004]

According to the present invention, a drive unit connected to an injection cylinder, a plunger sliding in the injection cylinder by the drive unit, and suction of air in a cavity are provided. In a die casting apparatus provided with a deaerator, a hydraulic chamber connected to a drive unit in parallel with an injection cylinder as a deaerator, a first piston operating in the hydraulic chamber in synchronization with the plunger, and a cavity And an air chamber communicating with the first piston and a second piston operating in synchronization with the first piston.

[0005]

When the plunger in the injection cylinder is operated, the first piston of the hydraulic chamber is operated by the same drive unit for driving the plunger, and the second piston is operated in conjunction with the operation of the first piston. If the air in the cavity is sucked by the operation of the second piston, an expensive device such as a vacuum pump is not required, and a simple configuration can be achieved.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the die casting apparatus of the present invention will be described with reference to the attached drawings. FIG. 1 is a structural example of the die casting apparatus of the present invention, FIG. 2 is an enlarged view of a part A in FIG.
FIG. 2 is an enlarged view of a portion B in FIG. 1.

As shown in FIG. 1, a die casting apparatus 1 according to the present invention comprises a movable die 3 capable of opening a mold with respect to a fixed die 2, a pouring port 5 communicating with a cavity 4, and a pouring port 5. And a plunger 7 is slidably provided in the injection cylinder 6.

[0008] A cavity 4 is formed between the fixed mold 2 and the movable mold 3 through a gap 8 as shown in FIG.
A basin 9 communicating with the basin is provided, and an air pocket 10 communicates with the basin 9 next to the basin 9.

An air pipe 11 is connected to the air pocket 10, and the air pipe 11 is connected to a degassing device 2 to be described later through a collecting block 12 as shown in FIG.
0 is connected to the air chamber 22 side.

On the other hand, the driving unit 14 is
Is connected. That is, the drive unit 14 includes a switching valve 17 connected to the hydraulic pump 15 via the relief valve 16, and a hydraulic pipe 18 extending from the switching valve 17.
Are connected to the injection cylinder 6.

The hydraulic pipe 18 is connected to a hydraulic chamber 21 of a deaerator 20.

That is, the deaerator 20 has a hydraulic chamber 21 connected to the hydraulic pipe 18 side and an air chamber 22 connected to the air pipe 11 side integrally formed. As shown in FIG. The first piston 23 in the chamber 21 and the second piston 24 in the air chamber 22 have the same piston rod 25.
Are linked by

The air pipe 11 is connected to a port 22 on one side of the air chamber 22 via a filter 26 (FIG. 1).
The other port 22b is connected to the second piston 24 and is open to the atmosphere. An air opening passage provided with a check valve 27 and a filter 28 as shown in FIG.

Therefore, the second piston 24 in the air chamber 22
2 moves to the right in FIG. 2, air in the chamber on the right side of the second piston 24 is pushed out from the port 22 b toward the atmosphere, and the chamber on the left side is in a vacuum state to suck air in the cavity 4. Become.

On the other hand, when the air moves to the left in FIG.
The air released to the atmosphere via the filter 28 and purified by the filter 28 is released to the atmosphere. Note that some air flows backward through the air pipe 11.

The connection between the hydraulic chamber 21 and the hydraulic pipe 18 is such that the operating direction of the plunger 7 and the moving direction of the first piston 23 are the same. When the first piston 23 moves in the injection direction, the first piston 23 also moves in the direction in which the air in the cavity 4 is sucked.

Next, the operation of the die casting apparatus according to the present invention having such a configuration will be described.

When the molten metal is poured from the pouring port 5 shown in FIG. 1, the hydraulic pump 15 is operated and the switching valve 17 is switched to move the plunger 7 forward to shot the molten metal.

At this time, the hydraulic pressure also acts on the first piston 23 of the hydraulic chamber 21 to move it to the right in the figure, whereby the second piston 24 moves to remove the air in the cavity 4 from the gap 8 and the hot water. Suction is performed through the reservoir 9, the air pocket 10, and the air pipe 11. At this time, the back pressure of the air in the cavity 4 increases due to the action of the molten metal pushed into the cavity 4 by the plunger 7, and the suction effect increases.

At the time of this suction, the gas generated in the cavity 4 due to the pouring of the molten metal is also sucked.
6, the purified air enters the air chamber 22.

Air is not mixed into the molten metal injected into the cavity 4 by the suction of the air.
Problems such as air biting do not occur.

Next, the product is solidified in the cavity 4 and the movable mold 3 is opened, and at the same time, the switching valve 17 is switched so that the plunger 7 moves backward, and at the same time, the first piston 23 also moves backward and the second piston 24 moves. Let it. Then, as described above, the air in the air chamber 22 is further purified through the check valve 27 and the filter 28 and released to the atmosphere. At this time, as described above, a part of the air is supplied to the air pipe 11.
However, at this time, no problem occurs because the mold is open.

Thus, an air suction mechanism having an extremely simple configuration can be configured at low cost.

[0024]

As described above, in the die casting apparatus of the present invention, the cylinder mechanism in which the air in the cavity was suctioned by using the vacuum pump in the past, was connected to the driving unit for driving the plunger. Thus, the air can be sucked, so that the apparatus can be configured at a low cost and can have a simple configuration. Such a simple structure exhibits good durability especially when used in a high temperature state such as in a foundry. In addition, by linking the operation of the second piston to the plunger, reliable operation can be expected, and further, the back pressure caused by the molten metal being pushed into the cavity can be used to enhance the suction effect.

[Brief description of the drawings]

FIG. 1 is a configuration example diagram of a die casting apparatus of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an enlarged view of a portion B in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Die-casting device 4 Cavity 6 Injection cylinder 7 Plunger 14 Drive unit 20 Deaerator 21 Hydraulic chamber 22 Air chamber 23 First piston 24 Second piston

Claims (1)

(57) [Claims] 1. A die casting apparatus comprising: a driving unit connected to an injection cylinder; a plunger sliding in the injection cylinder by the driving unit; and a deaerator for sucking air in a cavity. A pneumatic device, a hydraulic chamber connected to a drive unit in parallel with the injection cylinder, a first piston operating in synchronization with the plunger in the hydraulic chamber, an air chamber communicating with the cavity, A die casting apparatus comprising a second piston that operates in synchronization with the first piston.