JPH064997Y2 - Mold for casting - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a casting mold, and more particularly to a casting mold in which the coating layer formed on the surface of the mold is prevented from peeling off.

[Conventional technology]

When molding a material with a casting mold, pouring molten metal directly into the mold makes it possible to quench the molten metal and chill the material of the coarse material, or to generate gas from the molten metal and core and before pouring. It is not preferable because the discharge of the air in the mold is obstructed and the molten metal around the mold deteriorates, and the mold is welded to the rough material. Therefore, in order to prevent the above-mentioned problems, so-called coating is performed in which a coating agent is applied to the surface of the mold to form a coating layer.

[Problems to be solved by the invention]

However, even when the above-mentioned coating is performed, the coating layer slightly contracts when it is dried, and since the coating layer and the mold have different thermal expansion coefficients, slight stains on the surface of the mold and coating Even with minute defects in the mold layer, the mold layer is easily peeled off by casting several times. Therefore, there has been a problem that the coating must be performed again every short time, and the productivity is extremely low.

The present invention has been made to solve the above problems,
The purpose is to form a coating layer that is difficult to peel off on the mold surface,
It is an object of the present invention to provide a casting mold that improves the productivity of a coating mold.

[Means for solving problems]

In order to achieve the above-mentioned object, the casting mold of the present invention has a large number of grooves, whose opening width is narrower than the internal width, formed on the mold surface by corrosion processing, and the mold surface is coated with the mold. In addition to applying the agent, the groove is filled with the mold coating agent to form a mold coating layer integrated in the groove and the mold surface.

[Action]

According to the above configuration, the mold coating layer is uniformly formed on the mold surface, and the mold coating layer integrated with the mold coating layer on the mold surface is also formed inside the groove, and the groove opening portion is formed. Is narrower than the inside of the groove, and the mold-coating layer in the groove resists an external peeling force at the narrow opening wall portion, so that the mold-coating layer becomes extremely difficult to peel off. Further, the thickness of the coating layer is increased excessively only in the groove portion, and the thermal conductivity of the coating layer is small, so that the heat retaining property is improved. Furthermore, the gas generated from the molten metal and the core and the air that was in the mold before pouring were discharged to the outside through the inside of the mold layer, and the amount of gas released depended on the cross-sectional area of the mold amount. Therefore, the gas discharge is promoted by the amount corresponding to the coating layer in the groove.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a mold applied with a coating mold, and FIG. 2 is a process diagram showing a process of forming a groove on the surface of the mold. In FIG. 1, many grooves 2 are formed on the surface 1A of the mold 1, and the shape of the groove 2 is such that the width of the opening 2A is narrow and the width of the inside 2B is wide. A mold coating agent is applied on the surface 1A of the mold 1, and the mold coating agent is completely filled in the groove 2 as well, so that the surface 1A of the mold 1 and the inside of the groove 2 are filled with this mold coating agent. The mold coat layer 3 is integrally formed. Reference numeral 4 represents a space for pouring the molten metal.

Next, one aspect of a method of forming the groove 2 on the surface 1A of the mold 1 will be described.

When a leather pattern is formed on the surface of a resin molded product, it is generally performed to form a groove on the surface of the mold in advance. This embodiment is an application of this method. Mold 1
An acid resistant solution 5 is applied to the surface of the above to form an acid resistant film 5. In this case, the acid-resistant liquid is applied to a place other than where the groove 2 is desired to be formed (see FIG. 2 (a)). Next, when the mold 1 is immersed in a corrosive liquid, the part of the mold 1 not covered with the acid resistant film 5 is corroded. The depth of the groove 2 is determined by the corrosion time and the corrosion temperature, and can be freely set by controlling these.
Further, when the depth D of the groove 2 is 200 μ or less, corrosion does not occur in the groove 2.
200 toward the bottom of the (see Figure 2 (b))
When it is more than μ, the corrosion progresses toward the bottom as well as toward the side (see FIG. 2 (c)).
Therefore, by performing excessive corrosion such that the depth D of the groove 2 exceeds 200 μ, the width of the opening 2A of the groove 2 can be made narrower than the width of the groove interior 2B.

When a mold coating agent is applied to the surface 1A of the mold 1 having such grooves 2 formed therein, the mold coating layer 3 is formed on the mold surface, and the mold coating agent also penetrates into the groove 2. The mold coat layer 3 is also formed inside the groove 2, and the mold surface and the mold coat layer 3 in the groove 2 are integrated.

[Effect of device]

As described above, according to the present invention, a part of the mold coating layer is formed in the groove, and the opening of the groove is the narrowest. Since the mold coating layer in a large number of grooves acts as a retainer against the peeling force applied in the same direction as the direction, it becomes difficult for the mold coating layer to peel off, and in a mold having no groove on the surface, every 10 to 20 shots. With the mold according to the present invention, the recoating of the required coating agent can be completed in about 150 shots, and the durability of the coating layer can be remarkably improved.

Further, since the mold coating layer is thickened only in the groove portion, the heat retaining property of the mold is improved. Furthermore, the gas generated during casting is
Since it is discharged to the outside through the inside of the mold coating layer and the discharge is promoted by the increment of the cross-sectional area of the mold coating layer in the groove portion, the molten metal swirling performance is improved and a good quality rough material can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a mold having a coating mold according to the present invention, and FIG.
The drawing is a process drawing showing a process of forming a groove on the surface of a mold. 1 ... Mold, 2 ... Groove, 2A ... Opening portion, 2B ... Inside groove, 3 ... Coating layer.

Claims (1)

[Scope of utility model registration request] 1. A large number of grooves each having an opening whose width is narrower than an internal width are formed on a surface of a mold by corrosion processing, a mold coating agent is applied to the surface of the mold, and the coating is applied in the groove. A mold for casting, characterized in that a mold layer filled with a mold agent is formed in the groove and on the surface of the mold.