CAM CHAIN TENSIONER FOR DRIVE VALVE SYSTEM OF ENGINE

PROBLEM TO BE SOLVED: To provide a cam chain tensioner for a drive valve system capable of suppressing knocking sounds generated by vibrations of a chain. SOLUTION: The cam chain tensioner for a drive valve system of an engine is provided with a cam chain 22 for transmitting driving force of a crankshaft 17 to camshafts 18, 19, and equipped with a cam chain tensioner 25. In the tensioner, one end is rockably supported close to a crank shaft as a supporting point 31. An abutting surface 30 is formed in an arc shape, wherein a virtual diameter is set shorter than the distance 33 between the center of the crank shaft and the center of one cam shaft 18. An abutting surface is set so that only prescribed range of the distance between the center of the crank shaft and the center of one cam shaft including the center position abuts on the cam chain. In a part from a rocking support point of the tensioner to the abutting surface, a relief part 34 is provided to a cam chain side surface of the tensioner so as to separate from a reference line 29 of a cam chain for successively interconnecting connection pins 28 of the cam chain. COPYRIGHT: (C)2005,JPO&NCIPI