JPH08229632A - Method for coating copper alloy casting mold - Google Patents

Abstract

PURPOSE: To improve the adhesion of mold coating films to cavity surfaces by applying a mold coat on the cavity surfaces right after removing the oxide of the cavity surfaces. CONSTITUTION: Horizontal molds 30 of a copper alloy casting mold are heated to 200 to 250 deg.C before these molds are combined. The oxidized films generated on the cavity surfaces 50 are thereafter removed by sand blasting, wire brush, etc. The mold coat M is applied at a thickness of 0.05 to 0.3mm on the cavity surfaces 50 right after the removal of the oxidized films. The examples of the mold coat include the mold coat for heat insulation consisting of 50% kaolin, 45% water and 5% sodium silicate and the mold coat for heat insulation consisting of 15% tarc, 84% water, 1% sodium silicate. As a result, the fall of the mold coat is averted and the execution of adequate casting is assured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating a copper alloy mold.

[0002]

2. Description of the Related Art Conventionally, when a mold coating agent is applied to the cavity surface of a copper alloy mold, it is applied immediately after heating the mold.

[0003]

However, in such a conventional method, since an oxide film is formed on the cavity surface by heating, the adhesiveness of the mold coating agent is poor, and as a result, the coating agent is not coated during casting. It had the inconvenience that the mold was easily dropped.

An object of the present invention is to eliminate such inconvenience.

[0005]

In order to achieve the above object, in the method of coating a copper alloy mold according to the present invention,
After heating at least the cavity surface of the copper alloy mold, the oxide generated on the cavity surface is removed, and immediately after that, a mold coating agent is applied to the cavity surface.

[0006]

Since the copper alloy mold coating method according to the present invention is configured as described above, there is no oxide film between the mold coating film and the cavity surface. Adhesion to the surface is good.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view of a low pressure casting mold apparatus for a vehicle wheel, and FIG. 2 is an enlarged view of a portion II in FIG.

In FIG. 1, reference numeral 10 denotes a mold set for forming a vehicle wheel in this casting apparatus D.
The mold set 10 is a combination of molds made of a copper alloy, and is a combination of a lower mold 20, a pair of horizontal molds 30 and 30, and an upper mold 40. 50 is a cavity, which is formed by the mold set 10. The cavity 50 has a vehicle wheel shape and is composed of a disk forming portion 51, a spoke forming portion 52, and a rim forming portion 53. Reference numeral 21 is a nest of the lower mold 20, which is for forming the surface of the disk portion (of the vehicle wheel). Further, 41 is an auxiliary mold of the upper mold 40, and 411 is a nest of this auxiliary mold, which is for forming the back surface of the disk portion (of the vehicle wheel), respectively.

Reference numeral 211 denotes a weir, and the nest 21 (of the lower mold 20) 21
Is formed substantially at the center. 70 is a molten metal supply pipe,
It is connected to the weir 211 and extends downward. The molten metal of a molten metal holding furnace (not shown) is filled in the cavity 50 by low pressure casting through the molten metal supply pipe 70.

Next, the method of applying the mold coating agent in this mold will be described with reference to FIG.

Before assembling the horizontal type 30, 200 to 250 °
Heat to C. Then, the oxide film generated on the cavity surface 50 is removed by sandblasting, a wire brush or the like. After removing the oxide film, a coating agent M is applied to the surface of the cavity 50.
Apply to a thickness of 0.05 to 0.3 mm. In addition, as an example of the coating agent, a heat insulating coating agent made of kaolin 50%, water 45%, sodium silicate 5%, a heat insulating coating agent made of talc 15%, water 84%, sodium silicate 1%. Can be mentioned.

[0012]

EFFECTS OF THE INVENTION The method of coating a copper alloy mold according to the present invention comprises heating at least the cavity surface of the copper alloy mold, removing oxides generated on the cavity surface, and immediately after that, coating the cavity surface. Since a mold agent is applied, there is no oxide film between the mold coating film and the cavity surface,
As a result, the adhesiveness of the mold coating film to the cavity surface is good.

Therefore, by using this copper alloy mold casting method, when casting using a copper alloy mold, even if the mold is heated by the molten metal, there is no mold drop-off and proper casting is performed. be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a low pressure casting mold device for a vehicle wheel.

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

[Explanation of symbols]

 20… Lower mold (copper alloy mold) 21… Nesting (copper alloy mold) 30… Horizontal mold (copper alloy mold) 40… Upper mold (copper alloy mold) 41… Auxiliary mold (copper alloy mold) 411… Nesting (copper) Alloy mold) 50… Cavity

Claims (1)

[Claims] 1. A copper alloy mold characterized by heating at least a cavity surface of the copper alloy mold, removing oxides generated on the cavity surface, and immediately thereafter applying a mold coating agent to the cavity surface. Coating method.