To provide a chain tensioner high in the degree of design freedom with a small number of parts.
A plunger 13 and a return spring 14 imparting outward projecting property to the plunger 13 are built in a cylinder chamber 12 of a housing 11. The housing 11 is provided with an oil feed passage 16 communicating with a pressure chamber 15 formed behind the plunger 13. The plunger 13 is provided with a spring holding recess 18 for holding the return spring 14; a valve holding recess 19; and an oil discharge passage 20. A relief valve 21 is built in the valve holding recess 19. The relief valve 21 comprises a valve seat 22 pressed into an opening end of the valve holding recess 19; a valve element 24 opening/closing a valve hole 23 of the valve seat 22; and a spring 25 energizing the valve element 24 toward the valve hole 23.
COPYRIGHT: (C)2008,JPO&INPIT
RYONO YOSHIAKI
Torii Kazuhisa
Takayoshi Tagawa
Higashio Masahiro