CONTACT FORCE PREDICTION AND EXPERIMENTAL-VERIFICATION ON AN OHC FINGER-FOLLOWER-TYPE CAM-VALVE SYSTEM

Abstract

In this work, contact forces acting on a finger-follower-type cam-valve system are predicted with a lumped mass-spring-damper dynamic model and predicted values verified experimentally. Since it is extremely difficult to measure contact forces directly, an indirect method is suggested and tested. Dynamic strain at a specified point of the finger-follower was calculated when the predicted contact forces act on the finger-follower. Then the actually measured strain at the specified point is compared with the calculated dynamic strain. It was found that the measured and calculated dynamic strain agreed with each other very well for a wide range of cam-valve system operation speeds. That means the indirect method suggested is very effective and reliable to predict contact forces in a cam-valve system.