Evaporative pattern casting method of nodular cast iron flywheel casing

Abstract

The invention discloses an evaporative pattern casting method of a nodular cast iron flywheel casing. The method comprises processes of foaming, pattern making, paint brushing, shaping by box burying, smelting, tundish-cover nodulizing, multiple inoculation and stream inoculation, negative-pressure casting, and cleaning. During the tundish-cover nodulizing process, graphite is effectively thinned; graphite nodule amounts are increased; graphite nodules are round; and graphite nodule distribution is more uniform. With the combined inoculation technology of multiple inoculation and stream inoculation, inoculation effect is effectively enhanced, graphite nodules are thinned, incubation agent consumption is reduced, and a final silicon content of iron liquid is reduced. With the tundish-covernodulizing technology and the multiple stream inoculation technology, tissue and mechanical properties of the material are greatly modified and improved. With the method provided by the invention, the internal tissue of a produced flywheel casing casting is compact and uniform; the casting has less defects, good surface quality, and high dimensional precision. With the method, a plurality of components can be cast by using one mold, such that the process yield is improved.

Description

technical field [0001] The invention belongs to the technical field of casting, and in particular relates to a lost foam casting method for a high-strength and high-toughness ductile iron flywheel casing. Background technique [0002] The engine flywheel housing is one of the important parts of the car. It connects the engine body, clutch and transmission assembly. Generally, the engine rear suspension brackets of commercial vehicles are also installed on the left and right sides of the flywheel housing. In the case of emergency braking, the excessive load may damage the flywheel housing, resulting in the failure of the entire power transmission system. Most of the flywheel housing components used in the domestic diesel engine industry are gray iron castings, but the strength and toughness of gray iron castings can no longer meet the performance requirements of some current engines. The flywheel shell is a standard shell structure, most of which have a wall thickness of 5mm...

AI Technical Summary

Problems solved by technology

In order to save cost in manual core making, people often hollow out the thick non-formed part of the flywheel shell sand core manually, and fill it with dry sand mixed with a small amount of water and clay to support the whole sand core, but the manual hollowing operation Difficult, the sand core is easily damaged during the hollowing process, and the wall thickness is difficult to guarantee, the surface quality of the sand core is poor, the dimensional accuracy is low, and the process yield is also low

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