JPH0417942A - Metallic mold for casting - Google Patents

Abstract

PURPOSE:To prevent lowering of temp. in a forming block by arranging the forming block having forming face of fins, etc., in a fixed block and forming air heat-insulating layer at between outer face of the forming block and inner face of the fixed block. CONSTITUTION:By pouring molten metal into cavity formed with a lower mold 1, forming block 5 and upper mold 4 through a sprue 7, the formed product having the outer shape corresponding to the cavity. Then, in this case, as outer peripheral face of the forming block 5 is shut off from the air with the air heat-insulating layer caused by gap 6 formed at between outside of the forming block 5 and inner face of the fixed block 2 in side mold, the lowering of temp. in the forming block 5, particularly, the fin forming part, is prevented. Therefore, the molten metal is smoothly poured even in narrow space at between protected parts in each forming block 5 and without developing misrun of molten metal, the development of defect caused by the misrun into the fin parts in formed product is effectively prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a casting mold for casting a molded product having a large number of protrusions such as fins on its surface.

Generally, in a mold for casting a molded product having a large number of fins on the outer surface, a stack of a plurality of molded blocks each having protrusions for forming the fins on the inner surface is used as a lower mold and an upper mold. Interventions are being made in between.

However, such a mold has a problem in that the outer surface of the molded block is easily affected by the outside temperature. In other words, in a mold for casting a molded product having a fin shape, the temperature of the mold decreases due to the influence of outside air, etc., causing failure of hot water to flow back to the fin forming part, and the fin part may not be completely molded. There is a problem with that.

In view of these points, an object of the present invention is to obtain a casting mold that can minimize the temperature drop of a molding block for forming a molded product in the mold.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides for mounting a molded block having a molded surface such as a fin in a fixed block, and fixing the outer surface of the molded block and the fixed block to which the molded block is fixed. The feature is that an air insulation layer is formed between the inner surface and the inner surface.

(Function) Since an air insulation layer is formed on the outside surface of the molded block, the air insulation layer reduces the temperature drop on the outside surface of the molded block, and prevents the molten metal from flowing into narrow spaces for forming fins, etc. This prevents the occurrence of so-called poor water circulation, where the flow of water is inhibited by a drop in temperature. Therefore, the occurrence of defective products due to the above-described poor water circulation can be extremely reduced.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 shows a mold for low pressure casting, in which a side mold fixing block 2 is placed and fixed on a lower mold 1, and on the side mold fixing block 2, the lower surface of an upper mold die head 3 is attached. The upper mold 4 is placed and fixed.

The side type fixed block 2 is divided into a plurality of parts in the circumferential direction, and inside each divided side type fixed block 2,
A plurality of forming blocks 5 each having an inner surface provided with circumferentially extending protrusions 5a for forming the outer peripheral surface of a molded product having a large number of fins are stacked and mounted.

Incidentally, as shown in FIGS. 2 and 3, a gap 6 is provided between the outer circumferential surface of the laminate of the forming block 5 and the inner surface of the side mold fixing block 2. An air insulation layer is formed.

In addition, in FIG. 1, the reference numeral 7 is a sprue.

By injecting 8 metal molten metals into the cavity formed by the lower mold 1, molding block 5, and upper mold 4 through the molten metal lower, it is possible to cast a molded product having an external shape corresponding to the cavity. can.

By the way, in this case, the outer peripheral surface of the molded block 5 is cut off from air by the air insulation layer formed by the gap 6 formed between the outside of the molded block 5 and the inner surface of the side mold fixing block 2. Temperature drop in the molded block 5, especially in the fin molded portion, is prevented.

Therefore, the eight molten metals are smoothly injected into the narrow spaces between the protrusions 5a of each molded block 5, and there is no occurrence of poor molten metal tracing, and no defects are caused in the fin portions of the molded product due to poor molten water circulation. effectively prevented.

In the above embodiments, a case where a large number of fins are formed has been described, but it goes without saying that the present invention can also be applied to cases where small protrusions are formed.

[Effects of the Invention] As explained above, in the present invention, a molded block having a molded surface such as a fin is mounted inside a fixed block, and an air insulation layer is provided between the outer surface of the molded block and the inner surface of the fixed block. After forming, the temperature of the molded block is prevented from decreasing due to the outside air, and the occurrence of poor hot water circulation in the forming portions such as fins is eliminated, and the occurrence of defective molded products due to poor hot water circulation is effectively prevented.

[Brief explanation of the drawing]

1 is a longitudinal cross-sectional view of a casting mold of the present invention, FIG. 22 is a partially enlarged cross-sectional view of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line ■-■ in FIG. 2. 1. Lower mold, 2. Rhinoceros mold fixing block, 4. Upper mold,
5... Molded block, 6... Void, 7... Sprue. Applicant's agent Mr. Sato

Claims (1)

[Claims] Casting, characterized in that a molded block having a molded surface such as a fin is mounted inside a fixed block, and an air insulation layer is formed between the outer surface of the formed block and the inner surface of the fixed block to which the formed block is fixed. Mold for use.