No abstract

The piston pin contact in a typical automotive engine is an example of a highly loaded. Therefore, for piston pin design several aspects are important. Among them are function, cost, NVH, fuel economy, durability, and impact on other design aspects of the engine. Continuously contacting with piston pin, the face of connecting rod, brings about abnormal wear such as unfairwear or earlywear. because the engine get more powered and one requirement for a good fuel economy is to achieve a low level of mechanical friction. In this study, modern low friction coatings and treatment at the piston pin interface aimed to investigate the potential. The profile of coated specimens were observed by non-contact type optical surface measuring system and the friction-wear behaviors of coated specimens were investigated by using piston pin wear tester. Piston pin wear test was performed to analyze the friction and wear behavior. The results showed that the application of low friction coatings and treatment effectively improved tribological performance of the piston pin

The contact in the valve train system is known to be the part subject to significant load in an automobile engine. For such reason, the wear of the contact accounts for the greatest portion of entire friction loss of an engine, leading to the occurrence of abnormal wear. In order to reduce the wear in the valve train, this study first formed a crn layer to increase the bonding force with the base metal using the pvd coating method and then applied a 2-layer coating that formed the wc/c layer with low friction/wear resistance characteristics. In addition, it examined the friction characteristics occurring between the cam and tappet by using the dedicated wear tester and found that the friction torque value was reduced significantly through comparison testing with the existing part when the crn+wc/c coating was applied.