Method for casting vermicular graphite cast iron cylinder cover of diesel engine

Abstract

The invention belongs to the field of methods for casting a large-size diesel engine vermicular graphite cast iron cylinder cover, and in particular relates to a method for casting a vermicular graphite cast iron cylinder cover of a diesel engine. The method comprises the following steps: (1) manufacturing an air passage core box; (2) manufacturing an air passage sand core; (3) soaking in a coating; (4) inserting a graphite rod into a positioning hole of the air passage sand core; (5) removing rest sand cores and air passage sand cores of the cylinder cover; (6) casting the cylinder cover. The method is simple and high in operability, stable production can be achieved under the condition of molten iron control fluctuation, the rejection rate of the vermicular graphite cast iron cylinder cover of the diesel engine is reduced, the problems that the position of a guide rod hole of the vermicular graphite cast iron cylinder cover is loosened or the hole is shrunk are avoided, the leakage of a guide tube hole is controlled to be within 2%, and the casting quality of other parts is not affected. The economic loss of companies is reduced, and the manufacturing cost is lowered.

Description

technical field [0001] The invention relates to a casting method of vermicular graphite cast iron castings, in particular to a casting method of vermicular graphite cast iron cylinder heads of diesel engines, and belongs to the field of casting methods of vermicular graphite cast iron cylinder heads of large diesel engines. Background technique [0002] Vermicular graphite cast iron has been widely used in diesel engine cylinder heads. It has high strength, good heat resistance, certain shock absorption and plasticity, and is an excellent material for diesel engine cylinder heads. However, the casting shrinkage of vermicular graphite cast iron is only second to that of nodular cast iron, and shrinkage porosity or shrinkage cavities are easily formed at hot joints. For complex and demanding castings such as diesel engine cylinder heads, the pass rate is very low. It is understood that domestic manufacturers of vermicular graphite cast iron cylinder heads have shrinkage caviti...

AI Technical Summary

Problems solved by technology

However, the casting shrinkage of vermicular graphite cast iron is second only to that of nodular cast iron, and shrinkage porosity or shrinkage cavities are easily formed at hot joints. For complex and demanding castings such as diesel engine cylinder heads, the pass rate is very low

It is understood that domestic manufacturers of vermicular graphite cast iron cylinder heads all have shrinkage cavities or shrinkage porosity defects, pressure leakage at hot joint positions such as guide rod holes, and a failure rate of more than 10%, some reaching 30%, or even higher

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