Lost foam casting process for flywheel cover of heavy truck engine

Abstract

The invention relates to a lost foam casting process for a flywheel cover of a heavy truck engine. The lost foam casting process comprises the following steps of manufacturing a model of which the shape and the size are consistent with those of a casting from expanded plastics prepared by mixing expandable polystyrene and polymethyl methacrylate, coating the model with a refractory and air-permeable material, drying, hardening the model, placing the model in a sand box, filling dry sand, performing vibration ramming, pouring metal liquid, and performing vacuumizing to form negative pressure in the pouring process to realize the replacement of the foam model by the metal liquid and enable the foam model to disappear without traces. According to the process, various problems of a plurality of defects in the casting, surface roughness, high raw material consumption, severe environmental pollution and the like in a conventional sand mold casting process for the flywheel cover of the heavy truck engine are solved, and the lost foam has the advantages of high inner quality, surface brightness and cleanliness, high production efficiency, slight environmental pollution and the like.

Description

technical field [0001] The invention belongs to the field of heavy truck engine manufacturing, and in particular relates to a lost foam casting process for a flywheel housing of a heavy truck engine. Background technique [0002] At present, the traditional sand casting process is widely used in the casting of heavy-duty engine flywheel housings. The basic process is: first use wood or steel to make a part model, and then use this model to mold with the sand that has been added with a binder. The model is taken out from the sand mold to create a casting space cavity, and then the cavity is dried and hardened, and finally the metal liquid is poured into the casting space cavity, and the production process of the finished metal casting is obtained after cooling. Although the model can be reused, the process of taking the model out of the sand mold will lead to a decrease in the accuracy of the sand mold and a decrease in surface quality. At the same time, because the molding s...

AI Technical Summary

Problems solved by technology

Although the model can be reused, the process of taking the model out of the sand mold will reduce the accuracy of the sand mold and the surface quality. At the same time, because the molding sand uses a binder, the molding cost is high

[0003] This traditional sand casting method has backward technology, large investment in process equipment, large space occupation, large consumption of raw materials, large processing allowance, large machining workload, low production efficiency, high labor intensity, high production cost, and environmental pollution. It is very serious, and the dimensional deviation of the finished casting is large and the surface roughness is poor. At the same time, the casting is also prone to defects such as pores, shrinkage, sand inclusion, cracks, and segregation. The qualified rate of the casting is low and the yield rate is low.

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