| 摘要 |
PURPOSE:To make a zero point adjustment of valve clearance in a simple manner by allowing the inside of a cam which drives an intake and an exhaust valve, to be hollow, and also by allowing the section of the cam to be concaved and thined in wall thickness so as to swell the surface of the cam outward. CONSTITUTION:The inside of a cam which drives an intake and an exhaust valve, is made to be a hollow chamber 23 so as to enable pressure oil to be fed through a hole 21 made at the center of a cam shaft. And a section, particularly a lift section 24 of the cam 13 is made thin in wall thickness, and furthermore its outer surface for the section is formed into a concave form. Oil in a tank 26 is fed with pressure by a pump 27a where pressure in a feed pipe line 25 is regulated by controlling the opening of a valve 29 attached to a releaf pipe line 28. A control device controls the valve 29 based on the temperature detected by a temperature sensor 31, or based on an engine speed as required so as to control hydraulic pressure in the hollow chamber 23 in such a way that, for example, in case of low temperature or of a high engine speed, high pressure is applied allowing the section which is thined in thickness to be swelled outward to as to make a zero point adjustment of valve clearance. |
