When an EDU determines that a motor is in a control unstable state where the motor cannot be controlled to a target rotation speed due to a drive voltage output duty value being smaller than a threshold value, the EDU performs a control point shifting operation to shift a control point between a first control point, which is in the control unstable state, and a second control point, which is a control stable state outside the control unstable state. Thus, even when the motor is in a stepping rotation state, it is possible to control the target rotation speed regardless of influence of a cogging torque, and appropriately control the cam phase of the intake camshaft to a target phase when the engine is stopped.

A valve timing controller includes: a driving-side rotation member rotatable around a rotation axis and rotating in synchronization with a crankshaft of an internal combustion engine; a driven-side rotation member rotatable around the rotation axis and rotating integrally with a camshaft of the engine; a phase regulating mechanism setting a relative rotation phase of the driving-side and driven-side rotation members by an electric motor; a detection unit detecting the relative rotation phase; a stop control portion displacing the relative rotation phase by controlling the electric motor to stop the engine after the relative rotation phase reaches a stop phase; and a correction control portion displacing the relative rotation phase in a direction closer to the stop phase by controlling the electric motor, when the relative rotation phase is displaced beyond a set amount from the stop phase, in a state where the engine is stopped by the stop control portion.

Methods and systems are provided for adjusting engine cranking. In one example, a method for an engine cold start may include extending engine cranking at least based on one or more engine cold start conditions, where extending engine cranking may increase an engine oil pressure in a plurality of camshaft phaser cavities of a variable camshaft timing (VCT) phaser. In some examples, the method may further include, after engine cranking, enabling fueling. In this way, fuel efficiency considerations may be balanced with increases to the engine oil pressure such that components of the VCT phaser may be actuated and/or lubricated.

A phaser which has three camshaft start positions at start-up during cranking before the engine can fire. By having three possible start positions of the phaser, there is an increase in flexibility of the cam position at startup during cranking. The three start positions can also be achieved in open loop, reducing the complexity of the control system needed at cranking.

A valve timing controller includes: a driving-side rotation member rotatable around a rotation axis and rotating in synchronization with a crankshaft of an internal combustion engine; a driven-side rotation member rotatable around the rotation axis and rotating integrally with a camshaft of the engine; a phase regulating mechanism setting a relative rotation phase of the driving-side and driven-side rotation members by an electric motor; a detection unit detecting the relative rotation phase; a stop control portion displacing the relative rotation phase by controlling the electric motor to stop the engine after the relative rotation phase reaches a stop phase; and a correction control portion displacing the relative rotation phase in a direction closer to the stop phase by controlling the electric motor, when the relative rotation phase is displaced beyond a set amount from the stop phase, in a state where the engine is stopped by the stop control portion.

A decompression shaft (56) of a decompression device (50) includes an engagement pin (53) that is guided by a guide groove (51a) formed in a decompression weight (51), a decompression cam (54) that is provided on one cam surface of an intake valve cam (25c) and an exhaust valve cam (25b) so as to advance and retreat, and a connection portion (55) that connects the engagement pin (53) and the decompression cam (54). The decompression weight (51) is formed with a rotation restricting groove (51e) that restricts rotation of the decompression shaft (56) when a force acts in a direction in which the decompression cam (54) moves on the decompression shaft (56) from an advanced position to a retracted position when an engine (E) is stopped and that is continuous with the guide groove (51a).

Various embodiments include a method for actuating a camshaft adjuster of an internal combustion engine, in which a current is generated in an electric motor of the camshaft adjuster comprising: measuring an instantaneous strength of the current; calculating a mean value of the measured strength of the current over a predefined elapsed time; measuring a temperature of the camshaft adjuster; comparing the mean value of the measured strength of the current to a threshold value obtained from a characteristic diagram stored in a memory based on the measured temperature and the predefined elapsed time; and reducing the current if the calculated mean value of the strength of the current is higher than the threshold value.

A phaser which has an offset or remote pilot valve added to the hydraulic circuit to manage a hydraulic detent switching function, in order to provide a mid-position lock for cold starts of the engine, either during cranking or prior to complete engine shutdown. The mid-position locking of the phaser positions the cam at an optimum position for cold restarts of the engine.

A valve opening and closing timing control device includes: a drive-side rotary body rotating synchronously with a crankshaft; a driven-side rotary body arranged coaxially with the drive-side rotary body and rotating integrally with a valve opening and closing camshaft; a fluid pressure chamber defined between the drive-side and driven-side rotary bodies; advance and retard chambers defined by partitioning the fluid pressure chamber; an intermediate lock mechanism selectively switches between a lock state and a lock release state; advance and retard flow paths allowing a flow of the working fluid to be supplied to and discharged from the advance and retard chambers; a control valve including a spool; and a phase control unit moving a position of the spool by controlling a power supply amount to the control valve to supply and discharge the working fluid to and from the advance and retard chambers to displace a relative rotation phase.

An apparatus includes a valve and an actuator. The valve has a portion movably disposed within a valve pocket defined by a cylinder head of an engine. The valve is configured to move relative to the cylinder head a distance between a closed position and an opened position. The portion of the valve defines a flow opening that is in fluid communication with a cylinder of an engine when the valve is in the opened position. The actuator is configured to selectively vary the distance between the closed position and the opened position.