Abstract: A variable valve timing control apparatus has a drive rotary member having therein working chambers; a vane rotor relatively rotatably housed in the drive rotary member and defining the working chambers as retard and advance working chambers; and a spring forcing the vane rotor in one rotation direction with respect to the drive rotary member. The vane rotor has a tubular portion formed with the vane rotor and protruding from a middle position of a side of the vane rotor and a recessed portion formed on an outer peripheral surface of the tubular portion. An engaging end of an outermost circumferential portion of the spring is engaged with the drive rotary member, an engaging end of an innermost circumferential portion of the spiral spring is engaged with the tubular portion, and part of the innermost circumferential portion is inserted in the recessed portion.

Abstract: A variable valve timing control apparatus has drive rotary member having therein working chambers; vane rotor relatively rotatably housed in the drive rotary member and defining the working chambers as retard and advance working chambers; and spiral spring forcing the vane rotor all the time in one rotation direction with respect to the drive rotary member. The vane rotor has tubular portion formed integrally with the vane rotor and protruding from a middle position of one end side of the vane rotor and recessed portion formed on an outer peripheral surface of the tubular portion. Engaging end of outermost circumferential portion of the spiral spring is engaged with the drive rotary member, and engaging end of innermost circumferential portion of the spiral spring is engaged with the tubular portion, and a part of the innermost circumferential portion of the spiral spring is inserted in the recessed portion.

Abstract: In a valve timing control apparatus for an internal combustion engine, a torsion spring whose one end section is fixed into a front side of a housing and whose other end section is fixedly retained into a communication hole to bias a vane member to rotate in one direction, the communication hole being formed in an inner axial direction of the vane member to introduce a working oil within the back pressure into the engine.

Abstract: In a valve timing control apparatus for an internal combustion engine, a torsion spring whose one end section is fixed into a front side of a housing and whose other end section is fixedly retained into a communication hole to bias a vane member to rotate in one direction, the communication hole being formed in an inner axial direction of the vane member to introduce a working oil within the back pressure into the engine.

Abstract: A valve timing control system for an internal combustion engine includes a housing having and a cover member mounted thereto, a phase adjusting mechanism accommodated in the housing to hydraulically change the rotation phase of a crankshaft and a camshaft, a supply/discharge rod arranged through a through hole of the cover member and connected to the phase adjusting mechanism, a seal ring engaged with the supply/discharge rod to hermetically seal a clearance between the supply/discharge rod and the phase adjusting mechanism, a taper surface formed on the periphery of the through hole to increase the diameter of the through hole toward the outside of the housing, and a protrusion formed with the cover member in a radially inside area thereof to protrude in the axial direction of the system, wherein the through hole is formed at the protrusion.

Abstract: A valve timing control system for an internal combustion engine includes a housing having and a cover member mounted thereto, a phase adjusting mechanism accommodated in the housing to hydraulically change the rotation phase of a crankshaft and a camshaft, a supply/discharge rod arranged through a through hole of the cover member and connected to the phase adjusting mechanism, a seal ring engaged with the supply/discharge rod to hermetically seal a clearance between the supply/discharge rod and the phase adjusting mechanism, a taper surface formed on the periphery of the through hole to increase the diameter of the through hole toward the outside of the housing, and a protrusion formed with the cover member in a radially inside area thereof to protrude in the axial direction of the system, wherein the through hole is formed at the protrusion.