Patent ID: 8776742
Filing Date: 2014-07-15
Classification: F01L

Abstract:
1. A valve timing control apparatus for an internal combustion engine, comprising: a housing to which a turning force is transmitted from a crankshaft via a timing belt and at an inner peripheral side of which a plurality of working oil chambers are disposed; a vane member coupled to one end of a camshaft and relatively rotatably disposed within the housing; a lock piston disposed axially movably in an inner part of the vane member and whose axial tip end is retractably advanced toward a rear side of the camshaft; a biasing member disposed within a back pressure chamber disposed in front of the camshaft and opposite to the camshaft to bias the lock piston to be advanced toward the rear side of the camshaft; a limiting section on which the axial tip end of the lock piston is contacted to limit a relative rotation of the vane member to the housing; a communication hole formed in the vane member, and being structurally configured to introduce a working oil within the back pressure chamber into an oil pan via a drain passage; and a torsion spring whose one end section is fixed into the front side of the housing and whose other end section is fixedly retained into the communication hole, the torsion spring being structurally configured to bias the vane member to rotate in one direction.