Patent ID: 6920853

Claim:
A variable valve timing control device for controlling a valve timing of an intake valve or an exhaust valve of an internal combustion engine comprising: a rotation member for opening or closing a valve; a rotation transmission member engaged with the rotation member to be relatively rotatable; a vane provided on either one of the rotation member or the rotation transmission member; a hydraulic chamber formed between the rotation member and the rotation transmission member and including an advance angle chamber and a retarded angle chamber, the advance angle chamber and the retarded angle chamber being formed by dividing the hydraulic chamber by the vane; a first hydraulic passage for supplying and discharging a fluid to the advance angle chamber; and a second hydraulic passage for supplying and discharging the fluid to the retarded angle chamber; wherein the vane includes a surface hardness determined to be higher than a surface hardness of a sliding surface of the rotation member or the rotation transmission member for sliding the vane; and at least a tip end portion of the vane possesses a surface hardness higher than the surface hardness of the sliding surface of the rotation member or the rotation transmission member on which the tip end portion of the vane slides.