MEASUREMENT OF OIL FILM THICKNESS DISTRIBUTION ON PISTON SURFACE USING THE FLUORESCENCE METHOD (DEVELOPMENT OF MEASUREMENT SYSTEM)

A fluorescence image diagnostic method in which a filtered Xe-flash la mp and a video camera are used has been developed to observe the distr ibution and behavior of oil film on a piston surface in detail. A ligh t source with appropriate spectrum characteristics for measurement of the thickness of thin oil films was employed after theoretical conside ration of the absorption spectrum of the fluorescent dye and the oil w ith the fluorescent dye. A simple correction for measurement results o btained for a curved surface and calibration were carried out. The use of this system ensures that the distribution and behavior of oil film on the piston skirt and piston rings can be quantitatively measured, and the system is shown to have practical applications.