US Patent 7637235 Valve timing controller for engine

A valve timing controller of an engine reduces degradation of drivability such as a feeling of jumping out of a vehicle and achieves a rapid increase in engine output according to a throttle operation amount. An ECU shifts a phase of a cam shaft toward a control target value A at a reference update speed C1 when it is judged that a rider does not desire an output increase, and shifts the phase of the cam shaft toward the control target value A at a transient update speed C2 higher than the reference update speed C1 when it is judged that the rider desires an output increase.