JPH05161955A - Casting with double holes and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a casting with double holes and a manufacturing method thereof, by which the double holes can be arranged in the optional shape and necessary range. CONSTITUTION:A hole 13 is formed in the inner part of a casting body 14 by a core 2 covering a pipe 3 with shell 6 and the casting W1 with the double holes, which forms the double holes by removing the shell 6 on the core 2 embedded between wall surface of the hole 13 and the pipe 3 of the core 2 after casting, is formed, and after the core 2 covering the pipe 3 with shell 6 is inserted and arranged in a mold, molten metal is poured into the mold to insert the core 2 as cast-in and successively, the shell 6 of the core is removed to form the double holes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting product with a double hole such as a molding die having a double hole as a cooling water passage and a method for producing the same.

[0002]

2. Description of the Related Art In general, where a molding die is easily heated and needs to be cooled, a cooling water passage is provided to avoid a thin portion, a thin portion, a portion having a pin or a die hole, and the like. Further, when the molding surface of the molding die is curved, the cooling water passage also needs to be curved along the molding surface.

In the conventional molding die, when the installation space of the cooling water passage is narrow, as shown in FIG.
After manufacturing 5 (here, a rough mold) by casting, a hole 26 is drilled in the mold body 25, a pipe 27 is inserted into the hole 26, and the pipe 27 and the hole 26 are A gap 28 is formed between the wall surface and the pipe 27, and a cooling water passage having a double hole is provided in which the inside of the pipe 27 is a passage for cooling water and the gap 28 is a passage for returning cooling water.

[0004]

However, in the above-mentioned conventional molding die, since the cooling water passage is linear by drilling the hole 26, as shown in FIG. For example, if the mold hole 15 is provided, the cooling water passage cannot be provided up to the lower portion and along the molding surface 16 up to the upper portion. No suitable temperature distribution was obtained. Further, in the above-mentioned conventional manufacturing method, not only machining is required after casting, but when the molding surface 16 is curved, a hole is formed along the molding surface 16 and a pipe is inserted into the hole. Since the insertion is difficult, it was impossible to provide the cooling water passage along the molding surface 16.

The present invention has been made to solve the above-mentioned conventional problems, and provides a cast product with a double hole in which a double hole can be provided in an arbitrary shape and in a required range, and a manufacturing method thereof. It is an object.

[0006]

In the cast product according to the present invention, a core is formed by covering a pipe with a shell to form a hole in the main body of the cast product, and a wall between the hole and the pipe of the core is formed. The double shell is formed by removing the shell that fills the inner wall after casting.

Further, in the method for producing a double-hole cast product according to the present invention, a core in which a pipe is covered with a shell is inserted and arranged in a mold, and then a molten metal is cast into the mold to form the core. The casting is performed and then the shell of the core is removed to form a double hole.

[0008]

[Function] If the cast product is, for example, a molding die, a double hole is formed along the molding surface in a required range so that a temperature distribution suitable for cooling the molten metal during casting can be obtained by cooling water. ,
The double hole can be used as a cooling water passage, and the casting product can achieve a predetermined purpose by the double hole provided inside.

After casting by the shell mold method or the like,
Since it only removes the shell of the core with holes formed in the cast product, it is possible to manufacture a cast product with double holes by casting using existing casting equipment, and the required range within the cast product by the core Double holes can be formed in any shape.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A manufacturing method of an embodiment of the present invention will be described below with reference to FIGS.

2 and 3 are sectional views showing the core forming step and the casting step, respectively.

First, as shown in FIG. 2, a core 2 is molded using a core molding die 1.

That is, a pipe 3 made of stainless steel curved into a required shape is inserted and arranged in the core molding die 1, and a bottomed cylindrical bush 4 which is attached and fixed to the pipe 3 and which opens at the tip side is inserted. After holding it, the shell sand is blown into the cavity 5 formed by the core mold 1, the pipe 3 and the bush 4 with high pressure air, and then heated to about 300 ° C.
Forming a hardened shell 6 covering the pipe 3 and then
Remove the mold.

Next, the core 2 in which the pipe 3 is covered with the shell 6 is inserted and arranged in the mold 7 as shown in FIG. 3 and held through the bush 4, and then the mold 7 and the core 2 are used. Molten metal is cast into the formed cavities 8 and the core 2 is cast in to form a cast product 9, and then the mold 9 is demolded.

Next, the sprue 10, riser 11 and the like are cut from the casting 9, and the main body of the casting thus obtained is heated to about 500 ° C. to eliminate the binding force of the resin material binding the shell sand. Then, the cast product body is passed through the pipe 3 with the bush 4 standing upright to supply high-pressure air, water, etc., so that the shell 6 is collapsed and discharged from the connection port 12 provided in the bush 4 To do. Thereby, as shown in FIG. 4, a double hole having the pipe 3 inserted into the hole 13 is formed in the cast product W. Finishing processing is performed on the cast product W as necessary.

Next, a description will be given molding die W ₁ a casting W of one embodiment of the invention with reference to FIG 1.

In this molding die W ₁ , the core 2 in which the pipe 3 is covered with the shell 6 is circulated inside the die body 14 (casting body) from one end to the other end of the die hole 15 and the like. A hole 13 is formed in the core 2, and the shell 6 of the core 2 filling the space between the wall surface of the hole 13 and the pipe 3 of the core 2 is removed after casting to form a double hole.

In such a molding die W ₁ , the die body 1
Bypassing the mold hole 15 etc. from one end to the other end inside 4,
Further, since the double-hole cooling water passage is formed along the forming surface 16, the cooling water flowing in the cooling water passage can obtain a temperature distribution suitable for cooling the molten metal during casting.

Although the hole 13 forming the double hole is a blind hole, it may be a through hole depending on the type of the cast product W.

[0020]

As described above, the casting product with double holes according to the present invention, in the case of a molding die, has a double hole so that a temperature distribution suitable for cooling the molten metal during casting can be obtained by cooling water. By forming holes in the required area with a shape along the molding surface and using this double hole as a cooling water passage, the casting quality can be improved. Can be achieved.

In the method for producing a double-hole cast product according to the present invention, the double hole can be formed by simply removing the shell of the core in which the hole has been formed in the cast product after casting by the shell mold method or the like. , It is possible to easily, reliably, and inexpensively manufacture a cast product with a double hole by casting using existing casting equipment, and to form a double hole without the conventional machining. In addition, the core allows double holes to be formed in a desired area in a cast product in an arbitrary shape, and the range of applicable cast products can be expanded.

[Brief description of drawings]

FIG. 1 is a sectional view showing a cast product (molding die) with a double hole according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a core molding process according to an embodiment of the present invention.

FIG. 3 is a sectional view showing a casting process of the embodiment of FIG.

FIG. 4 is a cross-sectional view showing another cast product with double holes manufactured according to the embodiment of FIGS. 2 and 3.

FIG. 5 is a cross-sectional view showing a molding die manufactured by a conventional example.

[Explanation of symbols]

2 core 3 pipe 6 shell 7 mold 13 hole 14 mold body (cast body) 15 mold hole 16 molding surface W cast product W ₁ cast product (mold)

Claims (2)

[Claims] 1. A double core is formed by forming a hole in a main body of a cast product by a core having a pipe covered with a shell, and removing the shell filling between the wall of the hole and the pipe of the core after the casting. A cast product with a double hole characterized by having a hole formed. 2. A core in which a pipe is covered with a shell is inserted and arranged in a mold, a molten metal is cast in the mold to cast and enclose the core, and then the shell of the core is removed to remove the core. A method of manufacturing a cast product with a double hole, characterized by forming a heavy hole.