Wet friction materials for continuous slip torque converter clutch — Fuel economy improvement of passenger cars equipped with automatic transmission —

摘要

It was found that activated carbon possessed remarkably higher heat of adsorption for ATF additives (automatic transmission fluid additives) than any other materials contained within the clutch facing. Friction performance tests in low sliding velocity range were conducted for two kinds of clutch facings, containing activated carbon powder or graphite one as key ingredients for adsorption. As the additives mixed to the base oil to form the testing oils, polybutenyl succinimide (SI) was selected as a dispersant, and tricresyl phosphate and dialkyl phosphite were selected as a friction modifier. The results showed that the combination in activated carbon with SI was most effective to improve the initial anti-shudder performance of continuous slip torque converter clutch (CSTCC). It is considered that this effect was due to the strong adsorption of SI to the surface of activated carbon in the clutch facings.