| 摘要 |
PURPOSE:To keep good starting performance of an engine, by energizing a timer piston always in an ignition timing delaying direction by use of an energizing means such as a spring, and thereby enabling to bring the piston back to its original position positively when the engine is stopped even if malfunctioning of a hydraulic system for driving the timer piston is caused. CONSTITUTION:A timer apparatus Z of this invention displaces a piston 9 in a direction A by introducing high-pressure oil in a first oil chamber 21 via a first oil inlet port 25 through operation of an electromagnetic changeover valve 20, for instance, when the engine speed is raised and it becomes necessary to advance the fuel injection timing. Resultantly, a helical spline 14 formed in the outer surface of a sleeve 10 of the piston 9 and a helical spline 16 formed in the inner surface of a sleeve 32 of an input shaft 31 are brought into engagement with each other, and an intermediate shaft member 34, i.e., a cam shaft 1 is turned a predetermined angle to the input shaft 31 in the ignition timing delaying direction. Here, if malfunctioning of a hydraulic system for controlling the piston 9 is caused and the oil pressure is lowered, the piston 9 is brought back to its original position positively by the force of a spring 19. |
