JPH11192541A - Casting device for aluminum alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the production of castings of thin and intricate shapes by automatic pouring by communicating a casting pipe with a casting vessel, connecting a pressure control means with the casting vessel and feeding molten metal into a casting mold by a pressure reduction. SOLUTION: A metal material is inserted into a melting and holding furnace 2 and is then heated to form the molten metal. A molten metal treatment, such as degassing, is executed. The casting mold 13 is installed into a casting mold installation chamber and the casting mold 13 is sealed by a cap 14. The casting pipe immersed into the molten metal in the melting and holding furnace 2 is communicated with the metal feeding section 12 of the casting vessel 1. Suction casting is executed by hermetically sealing the casting vessel 1, opening solenoid valves 4, 5 and simultaneously reducing the pressure in the casting mold installation chamber 11 of the casting vessel 1 and the molten metal feeding chamber 12 by a vacuum pump. The molten metal feeding is stopped by closing the solenoid valve 4 after the completion of the casting and a differential pressure is generated in the casting vessel 1 by activating a pressure control means 7 to allow the casting to solidify in the state of the differential pressure. The differential pressure is controlled to 200 mmHg.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for casting a non-ferrous light metal such as an aluminum alloy, and more particularly to an apparatus for casting a thin complex product such as a lost wax precision casting.

[0002]

2. Description of the Related Art Conventionally, in a foundry for automobile parts and the like, an automatic hot water supply system has been frequently employed for the purpose of labor saving, rationalization and stabilization of quality, and various technical improvements have been made to a pouring apparatus. In the field of aluminum alloys, many automation technologies including hot water supply, such as die casting, die casting, and low pressure casting, have been developed.

[0003] On the other hand, in an aluminum alloy casting plant for small-scale production, manual pouring by ladle and casting by a device with reduced load on a ladle are common.

[0004] In the lost wax precision casting, since the target product is thin and complicated, vacuum suction casting,
Although casting techniques of special means such as pressure casting and rotary casting (rollover) are used, automation means including supply of molten metal is difficult.

[0005]

To automatically pump molten metal from a melting and holding furnace, a molten metal pump, an automated ladle, and a hot water supply using molten metal surface pressure have been put to practical use. Further, a hot water supply device utilizing vacuum suction is disclosed in Japanese Patent Application Laid-Open No. 9-220.
As disclosed in Japanese Patent No. 660, when cast into a mold of a thin complex product as it is, solidification starts under reduced pressure or atmospheric pressure, so that a sound quality product cannot be obtained. Further, even if hot water is supplied by using the pressure of the molten metal surface and casting is performed under atmospheric pressure, the molten metal does not sufficiently fill the thin-walled product portion, resulting in insufficient running of the molten metal. In addition, when the hot water supplied by this pressurization is applied to the inner surface of the mold as in low-pressure casting, casting can be performed. There is a problem that costs are high.

An object of the present invention is to provide a casting apparatus which is obtained as a result of repeated tests in order to solve the above-mentioned problems, and which automatically feeds and casts a thin complex product of an aluminum alloy from a melting and holding furnace. Is what you do.

[0007]

In order to solve such a problem, the present inventor has developed an aluminum alloy casting apparatus with a simple structure by providing a casting vessel with two chambers and providing pressure control means. Specifically, it is a casting apparatus for pouring a molten aluminum alloy into a casting mold, and a casting vessel for setting and casting the mold, and immersed in the molten metal of the melting and holding furnace, and communicated with the casting vessel. Casting pipe, an aluminum alloy casting apparatus characterized by having a pressure control means for supplying molten metal into the mold by decompression connected to the casting vessel, further comprising a casting chamber, After the molten metal is filled in the mold, each of which has the pressure control means, the molten metal is supplied into the mold, and then the molten metal is stopped and the solidification is performed under the pressure difference between the mold installation chamber and the hot water supply chamber. A casting apparatus for an aluminum alloy.

[0008]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described below. FIG. 1 is a schematic longitudinal sectional view of an aluminum alloy casting apparatus showing one embodiment of the present invention. The casting container 1 has a mold installation room 11 and a molten metal hot water supply room 12.
It is divided into chambers, and is provided with a vertical mechanism (not shown) so that it can be separated when the casting mold 13 is installed, and can be connected and sealed when pouring. After setting the mold, the lid 14 is used for sealing. The hot water supply portion 12 of the casting vessel communicates with the casting pipe 3 immersed in the molten metal of the melting and holding furnace 2. The outlet of the molten metal supply chamber of the casting vessel of the casting pipe is located immediately above the pouring port of the mold. In addition, it is desirable to use a heat-resistant ceramic nozzle in order to prevent the molten metal immersion portion corresponding to the hot water supply port from being melted by immersion for a long time. Further, the cast pipe is desirably heated by an electric heater in order to prevent the temperature of the molten metal from lowering.

[0009] The casting chamber 11 and the molten metal supply chamber 12 of the casting vessel are provided with a solenoid valve 4, a solenoid valve 5, a pressure control means 6 and a pressure control means 7 in the middle, respectively.
(Not shown) and connected to a vacuum pump (not shown)
The atmosphere of the mold installation chamber 11 and the molten metal hot water supply chamber 12 can be connected, cut off, and pressure controlled.

A series of steps up to casting will be described below.
First, a metal material is inserted into the melting and holding furnace 2 and then heated to form a molten metal. Normal molten metal processing such as degassing is performed, and casting becomes possible. In the melting and holding furnace, the melting furnace and the holding furnace may be separated to shorten the working time. With the mold container 1 separated, the mold 13 is installed in the mold installation chamber, and the mold 13 is sealed with the lid 14. After that, the casting container 1 is sealed, the electromagnetic valves 4 and 5 are opened, and the vacuum casting pump, which has been operated in advance, simultaneously reduces the pressure in the mold installation chamber 11 and the molten metal supply chamber 12 of the casting container 1 to perform suction casting. carry out.

After the casting is completed, the solenoid valve 4 connected to the molten metal hot water supply chamber 12 of the casting vessel 1 is closed to stop the hot water supply, and the pressure control means 7 is operated to generate a differential pressure in the casting vessel 1. And solidify the casting with the differential pressure. At this time, the differential pressure is controlled to be 200 mmHg.

The above is a series of steps. The amount of casting charged in the mold 13 was controlled by a timer. Other methods such as mounting a weight sensor below the mold 13 in the casting container 1 may be used. The pressure at the time of hot water supply is determined by the temperature of the molten metal, the diameter of the hot water supply pipe, the drop between the molten metal surface and the outlet surface of the hot water supply pipe, and the casting time, which will be described in Examples.

[0013] By combining the reduced pressure and the differential pressure, this apparatus can automatically pouring a thin and complicated product at the time of casting without human power. Further, since the hot water supply pipe feeds the hot water from the lower part of the molten metal in the melting and holding furnace, the quality of the molten metal is improved with less contaminants such as inclusions.

[0014]

EXAMPLE A JIS AC4C aluminum alloy was melted, and a product having a minimum thickness of 0.8 mm was cast by the apparatus of the present invention.
At this time, the temperature of the molten metal was 730 ° C. and the pressure at the time of casting was 2
The casting time was 50 mmHg and the casting time was 3 seconds.

[0015]

The casting apparatus for an aluminum alloy according to the present invention has a very simple structure and can produce a thin and complicated-shaped casting by automatic pouring. In addition, because of its simple structure, high-quality products can be supplied at low prices.

[Brief description of the drawings]

FIG. 1 is a schematic view of a vertical section of an aluminum alloy casting apparatus showing one embodiment of the present invention.

[Explanation of symbols]

1: Casting vessel 2: Melting and holding furnace 3:
Cast pipe 4: Solenoid valve 5: Solenoid valve 6:
Pressure control means 7: Pressure control means 11: Mold installation room 12: Molten hot water supply room 13:
Mold 14: Lid

Claims (2)

[Claims] 1. A casting apparatus for pouring a molten aluminum alloy into a casting mold, wherein the casting vessel is provided with a casting mold, and is immersed in the molten metal of a melting and holding furnace and communicated with the casting vessel. An aluminum alloy casting apparatus, comprising: a casting pipe; and a pressure control means connected to the casting vessel for supplying molten metal into the mold by reducing pressure. 2. The casting apparatus according to claim 1, wherein the casting container has two chambers: a mold installation chamber and a hot water supply chamber.
An aluminum alloy casting apparatus, each having the pressure control means, after filling the molten metal into the mold, stopping the supply of the molten metal and solidifying under a pressure difference between the mold installation chamber and the hot water supply chamber. .