To improve manufacturing work efficiency; and to reduce cost by simplifying a structure of a hydraulic circuit of a lock mechanism.
The opening-closing timing of an intake valve is varied by converting a relative rotational phase with both 1 and 2 by normally-reversely rotating a vane 3 relatively rotatable with a timing sprocket 1 by supply-discharge of relative hydraulic pressure to an ignition timing advance side hydraulic chamber 32 and an ignition timing delay side hydraulic chamber 33. The lock mechanism 10 is provided for regulating relative rotation of the vane and the timing sprocket until prescribed pressure acts on a pressure receiving surface 38 of a lock pin 34. A seal holding groove 29a formed on the outer periphery of one blade part 28a of the vane is constituted as a communicating hole for communicating mutual micro-clearances C1 and C2 formed between both side surfaces 3a and 3b of the vane and respective inside end surfaces 7a and 8a of a front cover 7 and a rear cover 8. The seal holding groove 29a is communicated with a pressure receiving chamber 36 of the pressure receiving surface front end.
TORII AKIRA
Hiromichi Kobayashi
Tomioka Kiyoshi