Connecting rod is widely used in all kinds of power machinery. It is an important part of all kinds of diesel or gasoline engines. In recent years, China’s annual automobile output has reached the production level of 1.5 million cars and 500000 trucks. Based on an average of 4.5 connecting rods per vehicle, the demand for connecting rods will reach more than 9 million. It can be said that the consumption of automobile connecting rods is very large. At present, China has more than 140 complete motorcycle manufacturers, agricultural machinery, air compressors, marine and other means of transport. The total demand for connecting rod forgings is expected to be about the same as that of cars. It is estimated that only the annual demand of China’s engine connecting rod forging market was about 10million pieces in 2005, and its market is huge.
Because the connecting rod bears high periodic impact force, inertia force and bending force in the process of mechanical transmission. This requires not only high strength, toughness and fatigue performance, but also high quality and precision. At present, the manufacturing industry of internal combustion engines in various countries attaches great importance to the production of connecting rods. Through the technological transformation of the “Eighth Five Year Plan” and “Ninth Five Year Plan”, China’s relevant enterprises have formed several professional connecting rod manufacturers with large quantities, but they still cannot meet the requirements of the growing automobile and internal combustion engine manufacturing industry for the batch and accuracy of connecting rods. Only when connecting rod parts are produced in batch can the cost be reduced and the quality be stable. Judging from the current situation, the main pressure processing equipment of China’s connecting rod manufacturers can only meet the processing requirements by using imported equipment, and a large amount of money is spent on the purchase and maintenance of equipment; Moreover, in the current connecting rod production line, the thickness of flash produced after forging is 2 ~ 6mm, plus heating and oxidation, the material utilization rate is generally 40 ~ 60%. How to improve the existing production process and mold design and improve the material utilization rate is an arduous task. Most enterprises are afraid of the production and investment of connecting rods, and the problem of large investment in line construction is waiting to be solved.