Variable valve timing control apparatus of internal combustion engine and method for assembling the same

摘要

A variable valve timing control apparatus has a housing; a vane rotor relatively rotating with respect to the housing; a torsion spring always forcing the vane rotor in one rotation direction with respect to the housing; and a spring guide accommodating therein the torsion spring. At least a part of an outside diameter of the torsion spring, before being installed inside the spring guide, is formed to be greater than an inside diameter of an inner wall of the spring guide. In a free state of the torsion spring, after being installed inside the spring guide, in which an urging force of the torsion spring acting on the vane rotor becomes smallest, the outside diameter of the torsion spring is substantially same as the inside diameter of the inner wall of the spring guide or is smaller than the inside diameter of the inner wall of the spring guide.

主权项

1. A variable valve timing control apparatus of an internal combustion engine, comprising:
a housing to which a turning force is transmitted from an engine crankshaft and which has shoes on an inner circumferential surface of the housing; a vane rotor having:
(a) a rotor secured to a camshaft; and(b) vanes defining an advance working chamber and a retard working chamber between the adjacent two shoes,the vane rotor relatively rotating to an advanced angle side and to a retarded angle side with respect to the housing by selectively supplying/discharging working fluid to/from the advance working chamber and the retard working chamber; a torsion spring always forcing the vane rotor in one rotation direction with respect to the housing by a retaining configuration in which one end of the torsion spring is retained by the vane rotor and the other end of the torsion spring is retained by the housing, the torsion spring being shrunk when the vane rotor relatively rotates with respect to the housing; and a spring guide accommodating therein at least a part, in an axial direction, of the torsion spring, and at least a part of an outside diameter of the torsion spring, before being installed inside the spring guide, being formed to be greater than an inside diameter of an inner wall of the spring guide, and in a free state of the torsion spring, after being installed inside the spring guide, in which an urging force of the torsion spring acting on the vane rotor with respect to the housing becomes smallest, the outside diameter of the torsion spring being substantially same as the inside diameter of the inner wall of the spring guide or being smaller than the inside diameter of the inner wall of the spring guide.