Method for casting bearing cap on subway locomotive by using sand faced permanent iron molding technology

Abstract

The invention relates to a method for casting a bearing cap on a subway locomotive by using a sand faced permanent iron molding technology. According to the method, a complete cavity which is in the shape of the bearing cap is obtained through the sand faced permanent iron molding technology, a bearing cap part can be directly casted for a next core, so that the appearance and the inner quality of castings are improved effectively, scrappage of the castings is reduced, the weight of the castings is reduced by 20%, heat treatment and hole drilling processing are not required for the casted bearing cap, and shortcomings of inside shrinkage, a shrinkage cavity and cracks of the bearing cap are overcome effectively. In addition, the technology of the method is simple, a large amount of time, labor cost and equipment cost are saved, and the production efficiency of enterprises is improved greatly. By the method, production cost can be reduced by 35%, economic benefit is obvious, a market prospect is wide, and the method can be conveniently popularized and used for most of foundry enterprises.

Description

technical field [0001] The invention belongs to the field of casting, and in particular relates to a method for casting an upper bearing cover of a subway locomotive by adopting an iron mold sand-covering process. Background technique [0002] In existing industrial production, self-hardening sand molding technology is used to produce upper bearing cap castings of subway locomotives. The process has the following defects in the process of preparation: due to the slow cooling of molten iron in the no-hardening sand process, shrinkage porosity, shrinkage cavities, and cracks are generated inside the casting, and the quality is unstable; the cooling speed of the casting is slow, the internal structure is not compact, and the spheroidization level Low (level 3), the material is unstable, the appearance of the produced castings is rough and poor, the machining allowance of the castings is large, and the cast bearing cover castings are then processed by drilling, which not only wa...

AI Technical Summary

Problems solved by technology

The process has the following defects in the process of preparation: due to the slow cooling of molten iron in the no-hardening sand process, shrinkage porosity, shrinkage cavities, and cracks are generated inside the casting, and the quality is unstable; the cooling speed of the casting is slow, the internal structure is not compact, and the spheroidization level Low (level 3), the material is unstable, the appearance of the produced castings is rough and poor, the machining allowance of the castings is large, and the cast bearing cover castings are then processed by drilling, which not only wastes materials, but also has high machining costs and complicated production processes. The labor intensity of workers is high and the production efficiency is low

In addition, the process uses a large amount of self-setting resin and raw sand, resulting in high production costs

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