抄録
The barrel form at the lower end of the piston skirt greatly affects piston slap noise in the case of gasoline engines. In order to clarify this mechanism, the distribution and thickness of oil film on the piston skirt was visualized and observed with a sapphire cylinder. In addition, the piston secondary motion was calculated by simulation model which can consider the stiffness and profile of the skirt. The results indicated that the barrel form had a large impact on the distribution and thickness of oil film on the skirt, but little impact on the piston motion. It was also found that piston slap noise reduction was caused by the damping effect of oil film distribution.
