Patent ID: 7503298

Claim:
A valve timing adjusting device comprising: a first rotor that integrally fixes: a housing having the bearing of a camshaft; a case internally having a plurality of shoes projecting therefrom and having hydraulic chambers formed between the shoes; and a cover covering the hydraulic chambers, and that rotates integrally with a crankshaft; a second rotor that has a plurality of vanes each dividing the hydraulic chamber into an advanced-angle hydraulic chamber and a retarded-angle hydraulic chamber, can relatively rotate through a predetermined angle within the first rotor, and is integrally fixed with an intake or exhaust camshaft; an engaging cavity provided in one of the first rotor and the second rotor; and a lock pin that is housed in a housing hole provided in the other of the first rotor and the second rotor, and that is projected therefrom by the energizing force of an energizing means, thereby abutting on the wall of the engaging cavity from an oblique direction to give a relative rotating force to the first rotor and the second rotor, wherein the housing hole of the lock pin is formed in the inner peripheral surface of the shoe of the first rotor that is opposite to the outer peripheral surface of the second rotor at an angle with the radial direction, and further wherein a work-guide surface intersected by the axis of the housing hole is provided in the surface in which the housing hole is to be machined, in the inner peripheral surface of the shoe of the first rotor opposite to the outer peripheral surface of the second rotor.