Valve timing control apparatus for internal combustion engine

Abstract

A valve timing control apparatus includes a driving side rotational member synchronously rotated with a crankshaft, a driven side rotational member provided coaxially with the driving side rotational member and synchronously rotated with a camshaft, a fluid pressure chamber being separated into an advanced angle chamber and a retarded angle chamber, a phase control apparatus controlling an operation fluid to be supplied to and discharged from one of, or both of the advanced angle chamber and the retarded angle chamber, for displacing a relative rotational phase between the driving side rotational member and the driven side rotational member within a range from a most advanced angle phase to a most retarded angle phase, a locking mechanism restraining the relative rotational phase at a lock phase between the most advanced angle phase and the most retarded angle phase.

1 . A valve timing control apparatus comprising: 
 a driving side rotational member synchronously rotated with a crankshaft;    a driven side rotational member provided coaxially with the driving side rotational member and synchronously rotated with a camshaft;    a fluid pressure chamber formed on at least one of the driving side rotational member and the driven side rotational member, the fluid pressure chamber being separated into an advanced angle chamber and a retarded angle chamber;    a phase control apparatus controlling an operation fluid to be supplied to and discharged from one of, or both of the advanced angle chamber and the retarded angle chamber, for displacing a relative rotational phase between the driving side rotational member and the driven side rotational member within a range from a most advanced angle phase to a most retarded angle phase; and    a locking mechanism restraining the relative rotational phase between the driving side rotational member and the driven side rotational member at a lock phase between the most advanced angle phase and the most retarded angle phase, wherein    during cranking, the relative rotational phase is displaced relatively in one of an advanced angle direction and a retarded angle direction while oscillating, and wherein    the phase control apparatus performs a starting point control for discharging the operation fluid from the advanced angle chamber and the retarded angle chamber during a predetermined period of time after a starting of cranking, and supplying the operation fluid into one of the advanced angle chamber and the retarded angle chamber for displacing the relative rotational phase to the other of the advanced angle direction and the retarded angle direction after the predetermined period of time is elapsed.    
   
   
       2 . The valve timing control apparatus according to  claim 1 , wherein 
 the predetermined period of time is set, in a condition where cranking is started with the fluid pressure chamber filled with the operation fluid, longer than, or equal to, a time required for a center of an oscillation of the relative rotational phase during cranking to be displaced to the lock phase from one of the most advanced angle phase and the most retarded angle phase positioned in the other of the advanced angle direction and the retarded angle direction.    
   
   
       3 . The valve timing control apparatus according to  claim 1 , wherein 
 the phase control apparatus discontinues the starting point control when the internal combustion engine is started, and starts a control after an engine starting.    
   
   
       4 . The valve timing control apparatus according to  claim 1 , wherein 
 The phase control apparatus includes:    a biasing mechanism set for displacing the relative rotational phase between the driving side rotational member and the driven side rotational member to the advanced angle direction, wherein    by means of the biasing mechanism and a pressure of the operation fluid supplied into one of the advanced angle chamber and the retarded angle chamber, the phase control apparatus displaces the relative rotational phase relatively in one of the advanced angle direction and the retarded angle direction while oscillating during cranking.