Fillet rolling and reinforcing technology of normalized nodular cast iron crankshaft

Abstract

The invention provides a fillet rolling and reinforcing technology of a normalized nodular cast iron crankshaft, belonging to the processing technology of an engine crankshaft. The technology comprises the following steps: a rolling wheel is utilized to directly roll the fillet of the crankshaft; during rolling, the rolling angle alpha is from 30 degrees to 45 degrees, the rolling pressure P is from 8000N to 15000N, the rolling radius R is from 1.5mm to 2.5mm, and the rolling depth h is from 0.1mm to 0.2mm. The technology can effectively improve the fatigue bending moment of the crankshaft bymore than 73.2 percent and satisfies the use requirements of a supercharged mid-cooling engine with high explosion pressure so that the nodular cast iron crankshaft can also be used in the supercharged mid-cooling engine with the explosion pressure of 12MPa to 14MPa or even higher, and the manufacture cost of the crankshaft is greatly decreased. The invention optimizes and combines various filletrolling parameters and avoids the bearing edge load phenomenon caused by rolling protrusions.

Description

technical field [0001] The invention relates to a processing technology for an engine crankshaft, in particular to a strengthening technology for an automobile engine crankshaft. Background technique [0002] Due to its high strength, high plasticity, high wear resistance, high shock absorption, excellent processing performance and low production cost, ductile iron has been widely used in the manufacture of automobile engine crankshafts. Especially in the crankshaft of naturally aspirated automobile engine whose explosion pressure is 7-9MPa, it has an absolute advantage. However, in recent years, with the improvement of emission requirements for automobile engines, supercharging technology has been more and more used in automobile engines. For supercharged and intercooled engines with an explosion pressure of 12-14MPa or even higher, the fatigue bending moment and other properties of the engine ductile iron crankshaft produced by the existing processing technology can no lo...

AI Technical Summary

Problems solved by technology

For supercharged and intercooled engines with an explosion pressure of 12-14MPa or even higher, the fatigue bending moment and other properties of the engine ductile iron crankshaft produced by the existing processing technology can no longer meet the requirements of service conditions, and other materials must be used to improve the performance of the engine. Cost of production

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