| 摘要 |
PURPOSE: To surely detect the timing of ignition of an internal combustion engine without increasing the number of parts and the manhour of assembly. CONSTITUTION: A mark 10 for indicating the position of the optimal ignition timing is provided on the outer circumferential surface of a rotor such as a pulley 7 installed on a crank shaft 2, a projection part 11 is integratedly provided on a casting-made cylinder block or a timing chain cover 5 so as to project toward the outer circumference of th e rotor, a wide width groove 12 which is opened to the top end surface of the projection part 11 and a narrow width groove 13 which is opened on the wide width groove 12 in the center part in width direction in the wide width groove 12 are provided on the projection part 11, and an inner width size in the wide width groove 12 is set within an allowable range of the shift of an ignition timing. |
