抄録
The soot contamination of engine oil seriously influences the tribo-characteristics for engine components. In the present study, the changes of the friction and wear characteristics for the cam and follower of the valve train are examined by using test oils blended with the dispersant and ZnDTP and/or MoDTC additives and mixed with carbon black substituted for engine soot. The object cam-followers are a slipper follower and a roller tappet. Key results of study are summarized as follows.(1) When lubricated with the oil mixed with carbon black, the friction and wear characteristics of cam and slipper follower are approximately similar to those lubricated with the oil mixed with exhaust gas soot. Also, even if the oil film becomes as thick as the size of co-aggregated carbon black, the friction is kept lower with less fluctuation and the wear rate is kept a little lower than those of thinner oil film.(2) In case of the roller tappet, the friction slightly changes with the carbon black contamination.
