A Study on Oil-Ring Conformability to Cylinder Bore

-Development of Measuring Method of Oil-Film Thickness by Using LIF Method-

Abstract

Cylinder bore shape under engine operating condition has much effect on lubricating oil consumption. This study aims at evaluating the conformability of oil-ring on cylinder bore under engine operating condition and clarifying the mechanism of lubricating oil consumption via the oil ring sliding surface. Laser-Induced-Fluorescence method was adopted to the three-piece-type oil-ring, and oil-film thickness was successfully measured. It was found that oil-film became thicker around the bottom dead center. Findings suggested that the cylinder bore shape, the piston tilting and vaporization of oil on the cylinder affected the oil-film thickness at the oil-ring sliding surface.