Patent ID: 9157345
Filing Date: 2015-10-13
Classification: F01L

Abstract:
1. A valve control apparatus for adjusting valve timing of an internal combustion engine, the engine having an intake valve that is opened and closed by a rotation of an intake cam shaft, and an exhaust valve that is opened and closed by a rotation of an exhaust cam shaft that receives a crank torque from a crank shaft, the valve control apparatus comprising: a forward phase adjustment unit that has a forward intermediate rotor rotatable relative to the exhaust cam shaft, the forward phase adjustment unit adjusting a forward phase that is a rotational phase of the forward intermediate rotor relative to the crank shaft; and a backward phase adjustment unit that has a backward intermediate rotor rotatable relative to the intake cam shaft and rotating in association with the forward intermediate rotor, the backward phase adjustment unit adjusting a backward phase that is a rotational phase of the intake cam shaft relative to the backward intermediate rotor, wherein the forward phase adjustment unit includes a forward stopper mechanism that prevents further advance of the forward phase by engaging the forward intermediate rotor at a forward-most advanced phase, which is a furthest-most advanced phase of the forward phase, a forward locking mechanism that locks the forward phase when reaching the forward-most advanced phase at a start time of the engine, and a forward biasing member that biases the forward intermediate rotor in an advance direction, wherein the backward phase adjustment unit receiving a cam torque from the intake cam shaft that is biased on average in a retard direction, the backward phase adjustment unit includes a backward stopper mechanism that prevents further retard of the backward phase by engaging the intake cam shaft at a backward-most retarded phase, which is a furthest-most retarded phase of the backward phase, and a backward locking mechanism that locks the backward phase when reaching the backward-most retarded phase at the start time of the engine.