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).

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.

An oil control valve for a cam phaser of an internal combustion engine, the oil control valve including a valve housing, including a first operating connection, a second operating connection, a supply connection, and a tank drain connection configured to drain a hydraulic fluid; a piston assembly, including a piston, a hollow check valve tube, a first check valve and a second check valve configured to provide cam torque recirculation, wherein the piston assembly is arranged in the housing axially displaceable by an actuator, wherein a control chamber is arranged within the piston between the first check valve and the second check valve and wherein a check valve compression spring which closes the first check valve and the second check valve is arranged within the piston between the first check valve and the second check valve.

An oil control valve for a cam phaser of an internal combustion engine, the oil control valve including a valve housing, including a first operating connection, a second operating connection, a supply connection, and a tank drain connection configured to drain a hydraulic fluid; a piston assembly, including a piston, a hollow check valve tube, a first check valve and a second check valve configured to provide cam torque recirculation, wherein the piston assembly is arranged in the housing axially displaceable by an actuator, wherein a control chamber is arranged within the piston between the first check valve and the second check valve and wherein a check valve compression spring which closes the first check valve and the second check valve is arranged within the piston between the first check valve and the second check valve.

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.

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.

An electronic phaser system configured for use in an engine system is provided. The electronic phaser system comprises an intake camshaft, an electronic phaser and an engine control module (ECM). The intake camshaft has a plurality of camshaft lobes. The electronic phaser couples a gearbox to the intake camshaft. The electronic phaser is configured to rotationally advance the intake camshaft an amount of crank degrees to a desired rotational position. The ECM targets a desired cranking compression ratio based on one of an engine stop request and an engine start request. The ECM converts the desired cranking compression ratio into a camshaft lobe centerline position and commands the electronic phaser to rotate the intake camshaft to the desired rotational position that satisfies the camshaft lobe centerline position to achieve the desired cranking compression ratio. The desired cranking compression ratio is between 5:1 and 6:1.