Patent ID: 6450137
Filing Date: 2002-09-17
Classification: F01L

Abstract:
A variable valve timing system for an internal combustion engine comprising:a rotation member rotating with one of a crankshaft and a cam shaft; a rotation transmitting member rotatably supported relative to the rotation member within a predetermined range and rotating with the other of the crankshaft and the cam shaft; a vane provided on the rotation member; a fluid pressure chamber formed between the rotation member and the rotation transmitting member and divided into an advanced angle chamber and a retarded angle chamber by the vane; the rotation member and the rotation transmitting member being relatively rotated by fluid pressure applied to the advanced angle chamber and the retarded angle chamber to change opening and closing timing of a valve to be actuated by the cam shaft by changing a rotation phase of the cam shaft relative to the rotation phase of the crankshaft; first relative rotation restricting means for restricting relative rotation between the rotation member and the rotation transmitting member from a most advanced angle position in which a volume of the retarded angle chamber is a minimum to a most retarded angle position in which the volume of the advanced angle chamber is the minimum by the vane at a position corresponding to engine start where the vane is positioned at approximately a middle of the fluid pressure chamber and releasing a first restriction by the fluid pressure applied to the retarded angle chamber; and second relative rotation restricting means for restricting relative rotation between the rotation member and the rotation transmitting member from the most retarded angle position to the most advanced angle position at the position corresponding to engine start and releasing a second restriction by the fluid pressure applied to the advanced angle chamber.