Production Process for Connecting Rod for Internal Combustion Engine

Author:  Z.Iida, M.Takashima, S.Muroga, S.Koike
Source:  US Patent 6,655,026 B1
Doc ID:  2003009
Year of Publication:  2003
Abstract:  
ABSTRACT Material for a connecting rod for an internal combustion engine is carburized and quenched, a carburized layer formed on the bearing portion is ground until the portion which exhibits the maximum compressive residual stress, and a shot-peening processing is performed on the ground surface. The invention produces a bearing portion having surface characteristics in which maximum compressive residual stress is imparted, and therefore, remarkable improvement in the fatigue strength in the bearing portion can be obtained. Furthermore, a large number of concavities formed by the shot-peening processing can be efficiently employed as an oil reservoir, so that sliding properties and lubrication can be improved, and the occurrence of problems such as fretting corrosion, galling, and seize can also be solved, and the galling and problems of the seize can be prevented.