System for measuring clearance between cam and contact surface of e.g. inlet valve of internal combustion engine, has determination system determining value of clearance from profile of cam and relative position of cam with contact surface

摘要

The system has an angular encoder for measuring an angular position of a cam (1), and a laser sensor (10) for measuring a distance separating the laser sensor from a contact surface (3) of a valve (4). Another laser sensor (11) measures a distance between itself and an angular portion (12) of the cam. A memory system stores various angular positions and distances measured by the laser sensors, and a determination system determines the value of a clearance between the cam and the contact surface from the profile of the cam and the relative position of the cam with the contact surface. An independent claim is also included for a method for measuring a clearance between a cam of a camshaft and a contact surface carried by a valve of an internal combustion engine.