POSITIONING DEVICE FOR ENGINE VALVE

摘要

PROBLEM TO BE SOLVED: To measure a valve position in firing with high accuracy by placing a variable capacitance electrode of a capacitive sensor detecting the displacement of an engine valve between a cylinder head and the engine valve. SOLUTION: The lower half of a cylindrical and conductive movable capacitance electrode 13 with an outside diameter slightly smaller than the inside diameter of a fixed electrode 12 fitted into the upper half of the cylindrical and conductive fixed electrode 12 and thereby a variable capacitance electrode 11 is constituted. The electrode 11 is built in an annular space A formed between a projection part projecting from a shaft 1a and a cylinder head 2 and a valve spring 7. In this case, the electrode 11 is built in a small gap becomes the dimension in a axial direction of the electrode 11 can be reduced. Therefore, actual displacement of a valve 1 in firing of an engine can be accurately measured easily even in a direct valve mechanism with a tapped 8 hard to measure.