| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a chain tensioner for preventing the outer peripheral edge of the end surface of a plunger from being seized in an initial set state of the plunger, while reducing the cost by constituting the plunger from a cylindrical member and a lid body. <P>SOLUTION: The plunger 13 and a return spring 22 are assembled in a cylindrical chamber 12 of a housing 11. The tension of a chain is made constant by hydraulic damper action of oil to be supplied into a pressure chamber 25 at the back of the plunger 13. A screw rod 18 is threadably mounted on a sawtooth-like female screw 17 at the internal periphery of a rear end opening for the plunger 13. The plunger 13 is formed of the tubular member 14 and the cold-forged lid body 15 having a fitting tube section to be fitted integrally with the tubular member 14 at the one end surface. When the diameter of a large diameter end of a tapered surface of an opening end of the fitting tube section is ϕA, and the outer diameter of the end part of the screw rod is ϕB, the tapered surface is brought into contact with the outer peripheral edge of the front end surface of the screw rod 18 in the initial set state where the plunger 13 is pushed while satisfying ϕA<ϕB. <P>COPYRIGHT: (C)2013,JPO&INPIT |
