【Summary】

The crankshaft is one of the key components in the engine. As the engine tends to be lighter, the structure is simpler, and the performance is better, the engine crankshaft manufacturing process has undergone great changes. High speed, high efficiency, flexibility and compounding are the main directions for the development of crankshaft manufacturing technology. The article firstly describes the selection method and technical requirements of crankshaft materials. On this basis, the key technical problems of crankshaft machining are analyzed and explained.

【Key words】

Crankshaft machining; crankshaft material; process method; strengthening process Crankshaft is one of the most important and most loaded parts of piston engines. The crankshaft is subjected to alternating torque and moment loads under operating conditions, which requires the crankshaft to have sufficient strength and stiffness and high precision. The level of crankshaft machining not only affects the size and weight of the machine, but also greatly affects the reliability and longevity of the engine. Therefore, it is very important to improve the crankshaft machining method and improve the machining accuracy.

Selection and technical requirements for crankshaft materials

Common materials for crankshafts According to the working conditions of the engine, the common materials for crankshafts are: ductile iron, quenched and tempered steel, non-tempered steel. Because the mechanical properties of ductile iron are close to quenched and tempered steel, the cutting performance is good, and the cost is only about l/3 of the cost of quenched and tempered steel. Therefore, the ductile iron crankshaft has been widely used in China and abroad. According to statistics, the proportion of spheroidal graphite cast iron materials for automotive engine crankshafts is 90% in the US, 85% in the UK, and 60% in Japan. Domestic gasoline engine crankshafts are generally made of ductile iron.