Variable valve timing device and method of assembling same

A valve timing varying device that varies an opening and closing timing of an intake valve or an exhaust valve driven so as to open and close via a camshaft by controlling an oil pressure in an advanced angle chamber and a retarded angle chamber, the valve timing varying device comprising:

• a housing rotor rotated on a rotation axis of the camshaft in synchronism with rotation of the crankshaft;
• a vane rotor rotated integrally with the camshaft and accommodated in an accommodating chamber of the housing rotor so as to relatively rotate within a predetermined angle range to divide the accommodating chamber into the advanced angle chamber and the retarded angle chamber;
• and
• a torsional coiled urging spring for urging the vane rotor toward one rotation direction relative to the housing rotor,
• wherein the housing rotor is composed of a bottomed cylindrical front side housing member having an opening though which a bolt for fastening the vane rotor to the camshaft is inserted from a front side, and a rear side housing member joined with the front side housing member,
• the urging spring has a coil part, a first end provided outside in a radial direction with respect to the coil part, and a second end provided inside in the radial direction with respect to the coil part,
• the front side housing member has a first latching concave part for receiving and latching the first end of the urging spring on an inside wall face facing the vane rotor, and
• the vane rotor has an accommodating concave part for receiving at least a part of the coil part of the urging spring, and a second latching concave part for receiving and latching the second end of the urging spring in an area facing the opening on a front end side facing an inside wall face of the front side housing member.