Casting process for bolt hole of large-scale ductile iron main bearing cover casting process

Abstract

The invention is mainly applied to the technical field of casting of the diesel engine bearing cover, in particular to a casting process for a bolt hole of a large-scale ductile iron main bearing cover. The casting process is characterized by comprising the steps that 1, a corundum mullite ceramic tube is selected; 2, a ceramic tube fixing core head is arranged, and resin sand is used for molding;3, the casting sand mold is coated with coatings and then is dried; 4, resin sand is filled in the middle of the dried ceramic tube; 5, the outer wall of the filled ceramic tube is coated with an alcohol-based fire-resistant coating and then is aired after being ignited; 6, the coated casting sand mold and the aired ceramic tube are dried again, and the dried ceramic tube is placed in the ceramictube fixing core head; and 7, mold assembling, pouring and cleaning are carried out. According to the casting process, the defects of using a sand core and a cast steel tube process such as penetration, deformation, blowholes, hard spots and the like are overcome; meanwhile, the operation of workers is simple, multiple pieces can be manufactured at the same time, the production efficiency is greatly improved, and the production cost of manufacturing a core box is also saved; and the ceramic tube has the advantages that the strength can be high, sand sticking and penetration can be prevented,and the defects of porosity and shrinkage can be overcome.

Description

technical field [0001] The invention relates to a bolt hole casting process of a large nodular iron main bearing cap, which is mainly used in the technical field of casting of diesel engine bearing caps. Background technique [0002] At present, the bolt holes of large ductile iron main bearing caps are mostly cast with sand cores and steel pipes. The disadvantage of using sand cores is that the quality is not easy to control and iron-clad sand is easy to produce. Moreover, the dimensional accuracy is not high, and the core is deformed, causing the casting to be scrapped without processing, and the labor intensity of the workers is high. The disadvantages of using steel pipes are high cost, difficult processing, and strict requirements on the temperature of molten iron. Otherwise, the fusion will not be good and the castings will be scrapped. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a casting process for ...

AI Technical Summary

Problems solved by technology

[0002] At present, the bolt holes of large ductile iron main bearing caps are mostly cast with sand cores and steel pipes. The disadvantage of using sand cores is that the quality is not easy to control, and iron-clad sand is easy to occur.

Moreover, the dimensional accuracy is not high, and the core is deformed, causing the casting to be scrapped without processing, and the labor intensity of the workers is high.

The disadvantages of using steel pipes are high cost, difficult to process, and strict requirements on the temperature of molten iron. Otherwise, the fusion will not be good and the casting will be scrapped.

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