JPH0760428A - Suction casting device - Google Patents

Abstract

PURPOSE:To prevent casting defect by reducing the pressure in a mold to suck molten metal into the mold. CONSTITUTION:A supporting member 17b providing a flexible seal member 17a is arranged so as to be divided into halves and possible to rotate to a supporting hole position 16 of the lower surface 12a of a chamber, and the seal means is formed with the flexible sealing member 17a and half divided supporting member 17b. By this method, the development of leakage is prevented and the high quality cast product is obtd. and the manufacturing cost of a pouring tube is reduced and the suction casting can be executed in a high workability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction casting apparatus which sucks molten metal into a mold by depressurizing the inside of the mold to perform casting. The present invention relates to a suction casting device capable of preventing the inflow of air from the inside.

[0002]

2. Description of the Related Art As a conventional suction casting apparatus, Japanese Patent Laid-Open No. 62-
There is one as shown in FIG. 3 of 187557.
This suction casting apparatus, as shown in FIG.
The sand mold 4 having the cavity 7 and the air passage 3 is housed in the chamber 2 connected to the chamber 2, and the pouring pipe 5 is fitted into the support hole 6 of the lower surface 2a of the chamber together with the seal member 10 to form the cavity 7 of the sand mold 4. And the outside of the chamber 2 are communicated with each other.

Then, the melting furnace 8 is filled with a molten metal 9 obtained by melting an iron-based material, for example, a cast iron molten metal or a cast steel molten metal,
The melting furnace 8 is arranged below the chamber 2 so that it can be moved up and down so as to sink into the molten metal 9.

To perform suction casting, the melting furnace 8 filled with the molten metal 9 is raised to immerse the pouring pipe 5 in the molten metal 9, and the vacuum pump 1 is operated to discharge the internal air of the chamber 2. Then, the pressure in the cavity 7 is reduced to less than atmospheric pressure, the molten metal 9 is sucked up by the pressure difference through the pouring pipe 5 and cast into the cavity 7 of the sand mold 4, whereby a suction casting product can be formed. Like

Heretofore, the use of ceramics or the like as the material of the pouring pipe 5 has been examined, but from the viewpoint of cost, the disposable iron pipe is the most common.

[0006]

However, in the above suction casting apparatus, the pouring pipe 5 is provided by the sealing member 10.
And air inflow from the joint between the chamber lower surface 2a (hereinafter,
It is difficult to completely prevent "leak"), and this leak is the largest cause of casting defects in the suction casting method. In addition, since the pouring pipe 5 is immersed in the molten metal 9 for each shot, even if the pouring pipe 5 is made of a high-melting-point iron-based material, melting and welding easily occur, and it is currently disposable. ing. Also,
Since it is essential to form a sealing flange portion on the pouring pipe 5 itself, there has been a complaint that the unit price is as high as 1,000 yen or more per pipe.

Further, when placing the sand mold 4 on the flange of the pouring pipe 5, a sealing material (not shown) is provided between the sand mold 4 and the flange and between the flange and the chamber lower surface 2a. Since it is necessary to intervene, there is a problem in that the number of working steps is increased in mounting the pouring pipe 5 on the lower surface 2a of the chamber and mounting the sand mold 4 on the flange of the pouring pipe 5.

The present invention has been made in view of the above circumstances, and it is possible to obtain a high-quality cast product by preventing the occurrence of leaks, reduce the manufacturing cost of a pouring pipe, and suction with good workability. An object of the present invention is to provide a suction casting device that can perform casting.

[0009]

In the suction casting apparatus of the present invention, a support member having a flexible seal member is provided in a support hole portion on the lower surface of the chamber, and the support member is divided and rotatable. The formation of the sealing means by the flexible sealing member and the above-mentioned divided supporting member is a means for solving the problem.

Here, in order to form the above-mentioned sealing means,
It is preferable that the support member is rotatably provided around a semi-cylindrical ridge formed in a support hole portion on the lower surface of the chamber.

The support member is usually made of steel.

The flexible seal member is not particularly limited as long as it has heat resistance and flexibility.

[0013]

When the sand mold is lowered, the sand mold first comes into contact with the flexible sealing member, and when the sand mold is further lowered, the sand mold is placed on the lower surface of the chamber, and the flexible sealing member is held between the sand mold and the supporting member. At the same time, the support member holds the upper end of the pouring pipe.

When the casting operation is performed in this state, the sand mold, the flexible sealing member, the pouring pipe and the supporting member are integrally attached via the casting, and as the sand mold rises, the casting, the flexible sealing member, The pouring pipe and the supporting member are integrally lifted and separated from the lower surface of the chamber.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The suction casting apparatus of the present invention will be described in more detail below with reference to the drawings. 1 to 4 show an embodiment of the suction casting apparatus of the present invention.

FIG. 1 shows a schematic sectional view of the suction casting apparatus of the present invention. In this suction casting apparatus, a vacuum pump, a chamber, a sand mold and a melting furnace are formed in the same manner as the conventional suction casting apparatus shown in FIG. However, the chamber 12 is formed so as to be able to move up and down, and the melting furnace 19 is fixedly installed without moving up and down.

The chamber 12 comprises a chamber body 12b and a chamber lower surface 12a, and the chamber body 12b is connected to a vacuum pump (not shown). In a main part of the lower surface of the chamber shown in FIG. 2, a semi-cylindrical convex strip 12c is provided to face a supporting hole portion 16 of the lower surface 12a of the chamber, and a half-divided support provided with a flexible seal member 17a. Members 17b (see FIGS. 4 (a) and 4 (b)) are arranged so as to face each other, and the half support member 17b is rotatable around the ridge 11 in FIG. A sealing means can be formed with the half support member 17b.

The flexible seal member 17a is made of silicon rubber and has a thickness of 5 mm. After the half support member 17b is arranged at a predetermined position, the half support member 17b is formed.
Placed on top of.

Further, the upper end of a tubular molten metal pouring pipe 15 made of steel and having no flange is inserted into the support hole portion 16 of the lower surface 12a of the chamber, and the lower end of the molten metal pouring pipe 15 is located at the melting furnace 1.
It is immersed in the molten metal 21 filled with 9. At this time,
The melting furnace 19 is fixed and is positioned with respect to the pouring pipe 15 by moving the chamber 12 up and down.

Next, the operation of this suction casting apparatus and the suction casting method using this apparatus will be described.

First, the sand mold 1 is moved by a lifting means (not shown).
When the sand mold 14 is lowered, the sand mold 14 contacts the flexible seal member 17a, and when the sand mold 14 is further lowered, the half support member 17
b rotates around the ridge 12c, and when the sand mold 14 is placed on the lower surface 12a of the chamber as shown in FIG. 3, while sandwiching the flexible seal member 17a with the sand mold 14 and the half support member 17b, The half support member 17b holds the upper end of the pouring pipe 15, and the flexible seal member 17a is in close contact with the sand mold 14, the chamber lower surface 12a, the half support member 17b and the pouring pipe 15, and seals the support hole portion 16. However, the inflow of air from the support hole portion 16 is prevented.

Then, after the chamber body 12b is attached to the chamber lower surface 12a, the chamber 12 is lowered by the cylinder 20 and the lower end of the pouring pipe 15 is immersed in the molten metal 21. After that, when the air in the chamber 12 is exhausted by the operation of the vacuum pump (not shown), the pressure in the cavity 22 of the sand mold 14 is reduced and the pressure is reduced to the atmospheric pressure or lower.
Next, the molten metal 21 filled in the melting furnace 19 is filled with the molten metal 1
5 and the air holes 13 of the sand mold 14 are sucked into the cavity 22 of the sand mold 14. After that, the molten metal in the cavity 22 is solidified, the exhaustion by the vacuum pump (not shown) is stopped, and the decompression in the chamber 12 is released.

Thereafter, the chamber body 12b is removed, and then the sand mold 14 is taken out upward by an elevating means (not shown). The casting 18, the pouring pipe 15, and the flexible sealing member 1 are then removed.
7a and the half support member 17b are integrally lifted and separated from the chamber lower surface 12a. Then, the sand mold 14 is separated and the casting 18 is taken out, and the casting operation is completed.

In this suction casting apparatus, the support member 17b is rotated around the ridge 12c when the sand mold 14 is lowered, and the flexible seal member 17a is moved to the sand mold 14 and the lower surface 1 of the chamber.
By sealing the support hole portion 16 in close contact with the 2a, the half support member 17b, and the pouring pipe 15, the sealing means can be easily formed, and the inflow of air from the support hole portion 16 can be prevented. For this reason, casting defects are less likely to occur, and high-quality cast products can be obtained.

Further, since the pouring pipe 15 is cylindrical and it is not necessary to form a flange, the manufacturing cost can be reduced.

[0026]

According to the suction casting apparatus of the present invention, since it is possible to prevent the inflow of air from the engaging portion between the pouring pipe and the lower surface of the chamber, it is possible to obtain a high-quality cast product with less casting defects. it can.

Further, since a cylindrical pouring pipe can be used, it is not necessary to form a flange as in the conventional case, and the manufacturing cost can be reduced.

Further, by providing the supporting member rotatably around the semi-cylindrical convex line formed in the supporting hole portion on the lower surface of the chamber, the flexible sealing member and the supporting member can easily form the sealing means. Can be formed.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a suction casting apparatus of the present invention.

FIG. 2 is an enlarged sectional view of an essential part showing a suction casting device (before sealing) of the present invention.

FIG. 3 is an enlarged sectional view of an essential part showing a suction casting device (after sealing) of the present invention.

FIG. 4 is a plan view and FIG. 4B is a front view showing a half support member.

FIG. 5 is a sectional view showing a conventional suction casting device.

[Explanation of symbols]

 12 chamber 12a chamber lower surface 12c convex strip 13 vent hole 14 sand mold 15 pouring pipe 16 support hole portion 17a flexible seal member 17b half support member (divided support member) 17c concave groove 18 casting

Claims (2)

[Claims] 1. A sand mold having a ventilation path is housed in a chamber whose inside pressure can be reduced, and a pouring pipe is inserted into a support hole formed in the lower surface of the chamber to connect the pouring pipe and the lower surface of the chamber. In the engaged suction casting apparatus, a support member (17b) having a flexible seal member (17a) is provided in the support hole portion (16) of the lower surface (12a) of the chamber, and the support member (17b) is divided and divided. The flexible seal member (17a) and the split support member (17b) are rotatably formed.
A suction casting device characterized in that a sealing means is formed by and. 2. The supporting member (17b) is rotatably provided around a semi-cylindrical ridge (12b) formed in a supporting hole portion (16) on the lower surface (12a) of the chamber. The suction casting apparatus according to claim 1.