JPS60221165A - Casting device - Google Patents

Abstract

PURPOSE:To improve productivity by providing a conducting pipe which connects a chamber enclosing a casting mold and the inside of a melting pen through a die plate. CONSTITUTION:The conducting pipe 10 connecting the melting pan 6 and the chamber 9 enclosing the casting mold is provided through the die plate 5. An inert gas is inserted into the chamber 9 and the pan 6 by opening the valve (a) of the pipe 10 to reduce the pressure down to a prescribed pressure then closing the valve (b) and opening further the valve (c). The chamber 9 and the pan 6 are always maintained under equil. pressure without any differential pressure in the process for restoring the inert gaseous atmosphere from the reduced pressure. The route for the pipe 10 is made shortest and since the substitution of the atmosphere is executed instantaneously, the fluctuation of casting conditions is eliminated and productivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a low-pressure casting apparatus in an inert atmosphere.

[Background of the invention]

Conventionally, in a low-pressure casting apparatus that performs vacuum degassing to further create an inert atmosphere, a conduction pipe 1 is connected to a mold enclosing chamber 3 on the upper side and a melting chamber 3 on the lower side with a die plate 2 in between, as shown in FIG. It is connected to the pot pot 4 through an outside piping.

The above-mentioned piping method using a conductive pipe causes the following problems.

That is, (a) the conduction pipe route is unavoidably long9, making it impossible to instantaneously control the differential pressure when reducing or restoring the pressure in the atmosphere.

Therefore, the replacement time becomes long and the set casting conditions are likely to fluctuate.

(b) Since the conduction pipe route is long, economic efficiency deteriorates as the amount of gas increases when replacing the atmosphere with inert gas.

(C) The mold surrounding chamber mechanically moves up and down with respect to the control plate. For this reason, the conduction pipe on the side of the mold surrounding chamber cannot be fixed, so damage to the pipe and leakage due to loose joints can cause serious problems in preventing the essential pressure difference between the mold surrounding chamber and the melting pot. When reducing or increasing the pressure, a conduction pipe is installed to prevent differential pressure, and the installation mechanism does not need to be attached to the outside of the mold surrounding chamber, and can replace the atmosphere with inert gas in a very short time. It relates to a casting device for the purpose of obtaining.

Figure 2 shows a schematic mechanism of a certain invention 11'' implementation date 11.A die plate 5 is sandwiched between the melting pot 6 for melting metal on the lower side, and atmosphere A is pressurized in the center of the melting pot 6. A stalk 7 is provided for the flow of molten metal into the mold cavity. Also on the upper side there is a chamber 9 surrounding the mold 8 and the birdhouse, and a conductive pipe 10 connecting the pot 6 and the mold surrounding chamber 9. It is composed of a vacuum pump 11.

During the operation of this casting device, a conduction pipe 1 is used to reduce and restore the atmospheric pressure between the mold surrounding chamber 9 and the melting pot.
The function of 0 will be explained below.

The mold enclosing chamber 9 is lowered when the mold 8 is set on the Goui plate. After that, when depressurizing the mold surrounding chamber 9 and the melting pot atmosphere, pulp a attached to the conduction pipe 11 is opened and after reaching a predetermined pressure, pulp b is closed and pulp C is opened to supply inert gas to the mold surrounding chamber. 9
and insert into the pot. Pulp a is closed in a state where both can restore pressure. Thereafter, when the pressure within the pot is increased above the pressure within the mold surrounding chamber, the molten metal passes through the stalk and is cast into the mold cavity. Finally, after the chamber 9 is raised, the mold 8 is taken out.

In the process of restoring the pressure from the reduced pressure to the inert gas atmosphere, the mold surrounding chamber 9 and the molten S ladle 6 are always kept at equilibrium pressure by the pipe 10 penetrated into the die plate, and no pressure difference occurs. Moreover, since there is no external piping of the chamber 9, the channel (a) conduction path is the shortest, and the time required for atmosphere replacement (atmosphere→decompression→inert gas) can be instantaneous.

As a result, fluctuations in casting conditions such as a drop in the molten metal pouring temperature and mold preheating temperature are eliminated. Furthermore, since the pitch of the casting cycle can be shortened, productivity is improved.

(b) Since there is no conductive pipe on the chamber side, problems such as damage to piping due to vertical movement and leakage due to loosening of joints are eliminated.

(C) With this mechanism, the conduction pipe can be installed only on the pot side and can be completely fixed.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional low-pressure casting apparatus, and FIG. 2 is a cross-sectional view of a low-pressure casting apparatus employing the conduction pipe of the present invention. 6... Melting pot, 7... Stokes, 8... Mold,
9... Mold surrounding chamber, 10... Conduction pipe,
11. ...Vacuum bonder.

Claims (1)

[Claims] In low-pressure casting equipment, the internal atmospheric pressure of the chamber surrounding the mold and the melting pot is simultaneously reduced or increased,
A casting device characterized in that a conductive pipe is provided so as not to generate a pressure difference between the two, and the pipe is passed through a die plate.