CN103639366A - Preparation method for U-shaped hole in casting - Google Patents

Abstract

The invention relates to the field of casting, in particular to a method for preparing U-shaped holes in castings. Modeling is carried out according to the designed casting structure; U-shaped hole cores are made of high-temperature resistant fibers and metal skeletons, or U-shaped hole cores are obtained by evenly applying casting coatings on the metal skeletons. The size of the U-shaped hole core is the same as the size of the formed hole. During the casting process, the U-shaped hole core is placed in the mold; after the casting is taken out, the U-shaped hole core is pulled out to obtain a U-shaped hole that meets the design requirements. type hole. The advantage of the invention is that it solves the problem that the conventional casting method cannot cast U-shaped holes.

Description

A kind of preparation method of U-shaped hole in casting

technical field

The invention designs the field of casting, and in particular relates to a method for forming U-shaped holes with different curvatures on castings by using high-temperature-resistant fibers or coatings for casting. the

Background technique

The formation of U-shaped holes is difficult to achieve either by ordinary cutting or traditional sand casting methods. Therefore, the formation of U-shaped holes on parts is generally divided into two categories: one is electron beam processing technology, which uses electron beams in the magnetic field The principle of medium deflection makes it deflect inside the workpiece, and can process fine U-shaped holes. By controlling the speed of the electron beam and the strength of the magnetic field, the radius of curvature can be controlled. However, the processing efficiency of this method is low, and the processing cost will be very expensive if a hole with a larger diameter is processed; the other is to use a metal elbow (the metal elbow is the same material as the casting) as the U-shaped hole core, and then pass Casting U-shaped hole. However, this method must strictly control the pouring temperature of the metal. Once the pouring temperature is designed to be too high or improperly operated, the metal elbow may be melted through, causing the workpiece to be scrapped. If the pouring temperature is designed too low, it may cause poor bonding between the metal elbow and the metal matrix, which is also not conducive to the quality of the workpiece. The present invention proposes to use high-temperature-resistant fibers or casting coatings with poor wettability and reactivity with the metal matrix as the surface material of the U-shaped hole core, and use metal with a higher melting point than the metal matrix as the skeleton material of the hole core. During the casting process, the U-shaped hole core is placed in the position of the pre-formed hole in the mold and fixed; after the casting is taken out, the U-shaped hole core is pulled out to obtain a U-shaped hole with a radius of curvature that meets the design requirements. The advantage of the invention is that it solves the problem that the conventional casting method cannot cast U-shaped holes. the

Contents of the invention

In view of the above-mentioned technical problems, the object of the present invention is to provide a method for forming U-shaped holes on castings using high-temperature-resistant fibers or casting coatings and metal skeletons, which adopts high-temperature-resistant fibers or The casting coating is used as the surface material of the U-shaped hole core, and the metal skeleton with high strength is used as the skeleton material of the U-shaped hole core, which not only ensures that the U-shaped hole core can be pulled out smoothly after the casting is cooled, but also ensures that the chemical composition of the hole wall is consistent Changes are made to form higher quality U-shaped holes. the

The purpose of the present invention is achieved through the following technical solutions:

a. Wind the high temperature resistant fiber evenly on the U-shaped metal skeleton, or evenly spread the casting paint on the U-shaped metal skeleton, and then get the U-shaped hole core, the size of the U-shaped hole core is the same as the size of the formed hole .

b. Put the U-shaped hole core into the pre-formed hole position in the cavity and fix it;

c. Pour the liquid metal obtained by smelting into the mold, and obtain the casting after cooling and solidifying;

d. After taking out the casting, pull out the U-shaped hole core to get the U-shaped hole;

According to the above scheme, high temperature resistant fiber or casting coating is used as the surface material of the U-shaped hole core, and a metal skeleton with higher strength is used as the skeleton material of the U-shaped hole core. The surface material of the hole core has poor wettability and reactivity with the metal. In the casting process, it does not react with the metal matrix, which can ensure that the chemical composition of the inner wall of the casting hole is the same as that of the matrix, and a relatively high-quality casting can be obtained; moreover, the metal skeleton has a certain strength, which can ensure that the U-shaped hole core can be pulled out smoothly after the casting is cooled. the

Description of drawings

Fig. 1 is a schematic cross-sectional view of a U-shaped hole core of the patent of the present invention. the

Detailed ways

In this embodiment, a U-shaped hole with a casting diameter of 5 mm and a developed length of 50 mm is taken as an example for illustration. Carry out molding according to the designed casting structure; according to the shape of the U-shaped hole, evenly wind the carbon fiber on the U-shaped iron frame, or evenly smear the graphite paint on the U-shaped iron frame, and then get the U-shaped hole core, the U-shaped hole The size of the core is the same as the U-shaped hole to be formed, that is, the U-shaped hole core is a U-shaped hole core with a diameter of 5mm and a developed length of 50mm. The U-shaped hole core is placed in the pre-formed hole position in the cavity; The metal aluminum liquid is poured into the casting mold at a pouring temperature of 700°C, and the casting is obtained after cooling and solidification; after the casting is taken out, the U-shaped hole core is drawn out to obtain a U-shaped hole. The limitations and improvements to the present invention under the concept of the invention all belong to the protection scope of the claims of the present invention. the

Claims (5)

1. a method of utilizing high-temperature fibre or the foundry facing U-shaped hole of moulding different curvature on foundry goods, comprises the steps:

Step a. makes and obtains U-shaped Kong Xin with high-temperature fibre or foundry facing and metallic framework, and the size of this U-shaped Kong Xin and institute's forming hole measure-alike inserted U-shaped Kong Xin in die cavity preexisting hole position and fix;

The molten metal that step b. obtains melting pours in casting mold, obtains foundry goods after cooled and solidified;

Step c is taken out after foundry goods, and hole core is extracted out, can in foundry goods, prepare U-shaped hole.

2. a kind of method of utilizing high-temperature fibre or the foundry facing U-shaped hole of moulding different curvature on foundry goods according to claim 1, it is characterized in that: the preparation of this U-shaped Kong Xin, be core crab material size on demand in hole is bent into U-shaped, thereon the resistant to elevated temperatures fibrous material of uniform winding or evenly smear casting use coating.

3. the surfacing of selected U-shaped Kong Xin can be carbon fiber or resistant to elevated temperatures other fibrous materials, and coating can be effective mixing of the foundry facings such as graphite paint or several cast paints, and its cast paint coating layer thickness is between 0.3 ~ 1.5mm.

4. a kind of method of utilizing high-temperature fibre or the foundry facing U-shaped hole of moulding different curvature on foundry goods according to claim 1, it is characterized in that: the framework material of selected U-shaped Kong Xin can be Iron and Iron Alloy, also can be other metals, as long as meet its fusing point, be greater than metallic matrix fusing point.

5. a kind of method of utilizing high-temperature fibre or the foundry facing U-shaped hole of moulding different curvature on foundry goods according to claim 1, is characterized in that: U-shaped hole angle of bend is the class U-shaped hole between 0 ° ~ 180 °.

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