A control method for stability of an intermediate phase Continuously Variable Valve Timing (CVVT) system may include comparing an oil temperature of the intermediate phase CVVT system with a predetermined value, and interrupting an operation of controlling the CVVT system when the oil temperature is lower than the predetermined value, comparing an engine RPM with a predetermined value, and interrupting the operation of controlling the CVVT system when the engine RPM is lower than the predetermined value, and comparing an operating current of the CVVT system with a predetermined management value A when the operation of controlling the CVVT system is not interrupted.

The present disclosure provides systems and methods to compensate for backlash within a cam phasing system. For example, compensating for backlash by commanding a predetermined amount of additional actuator movement to account for backlash within a cam phaser. According to some aspects, a spring is provided within a cam phaser to unidirectionally take up the backlash within the cam phasing system.

Systems and methods to extend a life of a component of a cylinder deactivation system are provided. A method includes initiating, by a controller, a CDA mode for an engine; determining, by the controller, a first cycle count for a first oil control solenoid of the CDA system; determining, by the controller, a second cycle count for a second oil control solenoid of the CDA system; comparing, by the controller, the first cycle count and the second cycle count; and modifying, by the controller, operation of the CDA mode for the engine based on the comparison.

To provide a control device capable of calculating a cam phase equal to an actual cam angle even when a corresponding cam angle signal detection range is exceeded by changing a cam phase by a variable valve mechanism. In addition to the conventional cam angle measuring function, a cam angle measuring means for advancing or retarding beyond a cam angle measurement reference position, and a means for determining that the cam angle signal advances or retards beyond the cam angle measurement reference position are provided. By switching the cam angle measuring function according to a determination result as to whether the cam angle signal exceeds the cam angle measurement reference position, it is possible to improve the time resolution of the angle measurement while maintaining the cam phase change amount at the same wide angle as the conventional one.

The present disclosure relates to internal combustion engines. Various embodiments of the teachings may include a method for adjusting an actuator element for a camshaft of an internal combustion engine, wherein the actuator element is coupled to the camshaft to adjust a camshaft setting. The method may include determining a torque imposed by a component of the engine, based on an operating parameter and controlling an adjuster of the actuator to counteract the determined torque and resist adjustment of the actuator element and the camshaft setting. Without controlling the adjuster, the torque is transmitted from the camshaft to the actuator element and can bring about an adjustment of the actuator element and of the camshaft setting. The magnitude of the adjustment corresponds to the torque imposed by the component.

A valve opening/closing timing control device is configured to implement controlling of a relative rotation phase and controlling of a lock mechanism by means of a small control valve. The valve opening/closing timing control device includes a first valve whose position is switched electromagnetically and a second valve whose position is switched by a fluid pressure controlled by the first valve. The second valve is constituted of at least one of a phase control valve that controls the relative rotation phase by providing an advance chamber or a retard chamber with an operating fluid from a fluid pressure pump and a lock control valve that controls a lock state of the lock mechanism by controlling the operating fluid from the fluid pressure pump.

A system for controlling a variable valve apparatus may include a plurality of oil control valves (OCVs) configured to respectively supply oil from an oil pump to a plurality of variable valve apparatuses or block the supply of the oil, and a single relief valve coupled to the plurality of oil control valves, wherein pressure in a plurality of control galleries for providing an oil supply path from the plurality of oil control valves to the plurality of variable valve apparatuses is maintained constant by only the single relief valve.

A system for controlling a variable valve apparatus may include a plurality of oil control valves (OCVs) configured to respectively supply oil from an oil pump to a plurality of variable valve apparatuses or block the supply of the oil, and a single relief valve coupled to the plurality of oil control valves, wherein pressure in a plurality of control galleries for providing an oil supply path from the plurality of oil control valves to the plurality of variable valve apparatuses is maintained constant by only the single relief valve.

Methods and devices are provided for locking and unlocking a phase control apparatus. In one example, a phase control apparatus is provided with a locking plate including a drive wheel, a pin recess, and a ramped channel opening into the pin recess and a housing coupled to the locking plate. The phase control apparatus also includes a vane rotor including a vane and positioned in a hydraulic chamber of the housing and a locking pin positioned within a bore of the vane and movable into a locked position where the locking pin engages with the pin recess.

Disclosed is a control device for an engine provided with a first intake valve and a second intake valve in an intake port. The control device comprises: a variable valve operating mechanism (72) configured to control a valve opening timing and a valve closing timing of an intake valve (21a); and a variable valve operating mechanism (72) configured to control a valve opening timing and a valve closing timing of an intake valve (21b), independently of the intake valve (21a). The latter variable valve mechanisms (72) is operable, in an intake stroke of the engine, to close the intake valve (21b) after the elapse of a delay time rt since the intake valve (21a) is closed. The delay time rt is a time period during which a pressure wave generated upon closing of the intake valve (21a) reaches the intake valve (21b) through the intake port (16).