JPH0530846Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a suction casting device for suction casting a molten metal by reducing the pressure in a mold cavity.

(Prior art) By reducing the pressure in the mold cavity, a pressure difference is created between the pressure inside the cavity and the external pressure acting on the molten metal, and this pressure difference causes the molten metal to be sucked and filled into the cavity. It is well known that casting is carried out by holding .

In such a suction casting apparatus, it has already been proposed to form a mold by plaster casting in order to form a thin-walled casting (Japanese Patent Laid-Open No. 58-141843).
issue). This will be explained using FIG. 2. In the figure, 1 is a flask, 2 is plaster poured into the flask 1, and the flask 1 and the plaster 2 constitute a mold 3. A chiller 4 is placed on the upper surface of the mold 3, and a decompression chamber 4a is formed in the chiller 4. Reference numeral 5 denotes a clamper for fixing the mold 3 and the chiller 4, and the mold 3 and the chiller 4 are tightened by bolts 6 passing through the clamper 5. 7 is a decompression chamber 4a
8 is an O-ring provided between the chiller 4 and the mold 3, and 9 is a hanging fitting for supporting the clamper 5.

To carry out suction casting using such a structural device, the lower end of the mold 3 is immersed in the molten metal 10 and the pressure in the vacuum chamber 4a is reduced, and the molten metal is sucked and filled into the cavity 11 by this pressure reduction. Ru.

(Problems to be Solved by the Invention) In the conventional example as described above, since the plaster 2 is directly immersed in the molten light alloy, the gypsum reacts with the molten light alloy.

In addition, since the flask 1 into which plaster has been poured is directly immersed in the molten metal, the molten metal adheres to the flask 1. Therefore, when pouring plaster into the flask 1 in the next cycle and plastering, the flask It is necessary to remove the light alloy attached to 1.

The present invention was made to solve the above-mentioned problems, and its purpose is to provide a suction casting device in which plaster and molten metal do not react and do not require light alloy removal work.

(Means for Solving the Problems) In the present invention, a mold is formed by an inner container and an outer container, and a stalk is further extended to the outer container.

(Function) Since the stalk is not filled with gypsum, the gypsum does not come into contact with the molten metal even if the stalk is immersed in the molten metal.

Furthermore, since the inner container for plastering is not immersed in molten metal, molten metal does not adhere to the inner container.

(Effect of the invention) As described above, since the gypsum and the molten metal do not come into contact with each other, there is no reaction between the gypsum and the molten metal.

In addition, since molten metal does not adhere to the inner container, there is no need to remove molten metal when plastering, which improves setup work efficiency.

(Example) Examples of the present invention will be described below with reference to the drawings. In FIG. 1, 20 is a mold;
is formed by an inner container 201 and an outer container 202. The inner container 201 is formed in the shape of a truncated cone with both upper and lower ends open, and is arranged such that the end with the smaller opening area is located below the end with the larger opening area.

The outer container 202 includes a main body 202a having almost the same shape as the inner container 201, a stalk 202b extending from the lower end of the main body 202a, and a stalk 202b.
It is formed from an annular inclined part 202c extending upward and inward from the base of the main body part 202a, and a flange part 202d projecting outward from the upper part of the main body part 202a.

A holder 21 is placed on the top of the outer container 202. This holder 21 consists of a cylindrical part 211 with an open lower end and a storage part 212 protruding from the upper surface of the cylindrical part 211. The lower end of the cylindrical part 211 is placed on the flange part 202d of the outer container 202. There is. A blind hole 213 is formed in the storage section 212,
A pin 214 is slidably inserted into the blind hole 213, and a spring 215 is compressed between the bottom of the blind hole 213 and the pin 214. A fixing plate 217 is fixed to the opening of the blind hole 213 by bolts 216, and the pin 214 passes through the fixing plate 217 in a slidable manner. This fixing plate 217 prevents the pin 214 from coming off. Cylindrical part 2
11 forms a decompression chamber 22, and the cylindrical part 21
A suction hole 218 is formed in the upper wall of the suction hole 2.
A suction pipe 219 is connected to 18.

The mold 20 and the holder 21 as described above are fixed by a clamper 23, and the mold 20 and the holder 21 are fixed together by a clamper 23.
1 is tightened by a bolt 24 that passes through the clamper 23 and can freely come into contact with the upper surface of the storage section 212. Reference numeral 25 denotes a cold metal that covers the upper opening of a cavity 27 formed of plaster 26, which will be described later.

To assemble the above device, first pour plaster 26 into the inner container 201 to form a cavity 27,
The inner container 201 coated with plaster in this way is placed in the outer container 20.
Store in 2. At this time, the lower end surface of the plaster 26 is supported by the upper end surface of the annular inclined portion 202c of the outer container 202, and a gap g is formed between the inner container 201 and the outer container 202, and this gap g is used as the gas vent passage 28. do. This degassing passage 28 has one end connected to the decompression chamber 2.
2, and the other end opens to the lower end opening of the inner container 201. Next, after placing the chiller 25 in the upper opening of the cavity 27, the holder 21
Set up. By installing the holder 21, the chiller 2
5 is pressed by pin 214. Then, the mold 20 and the holder 21 are fixed by a clamper 23.

Next, a case in which the above device is used will be described.
To perform suction casting, move the stalk 202b to the molten metal 2.
9, and the pressure in the vacuum chamber 22 is reduced. Due to this reduced pressure, the molten metal 29 is sucked and filled into the cavity 27. At this time, gas is generated from inside the cavity 27, and this gas flows into the gas venting path 28 from the lower end of the gas venting path 28 and flows out into the decompression chamber 22.

Note that the pressing force by the pin 214 is supported by the annular inclined portion 202c via the chiller 25 and the plaster 26, and does not act on the inner container 201. No gap is generated between the inclined portion 202c and the molten metal does not enter between them.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a suction casting device according to the present invention;
FIG. 2 is a sectional view of a conventional suction casting apparatus. 20...Mold, 201...Inner container, 202...
Outer container, 202b...stoke, 26...gypsum.

Claims (1)

[Claims for Utility Model Registration] (1) A suction casting device characterized in that a mold is formed by an inner container for plastering and an outer container, and a stalk is extended to the outer container. (2) The suction casting device according to claim 1, wherein the holder forming the decompression chamber is provided with a pin that presses with elastic force against the chiller that covers the upper opening of the mold cavity. . (3) The suction casting device according to claim 1 or 2 of the utility model registration claim, wherein a gas vent path is formed by communicating the gap between the inner container and the outer container with the decompression chamber and the gypsum.