Methods and systems are described for an engine with a cam torque actuated variable cam timing phaser. Phaser positioning control is improved by reducing inaccuracies resulting from inadvertent spool valve and/or phaser movement when the spool valve is commanded between regions. In addition, improved spool valve mapping is used to render phaser commands more consistent and robust.

A valve opening/closing timing control device is configured to be capable of appropriately setting a valve opening/closing timing within a short period of time from start-up of an internal combustion engine. An advancing chamber and a retarding chamber for relative phase control are formed between a driving rotating body that rotates synchronously with a drive shaft of an internal combustion engine and a driven rotating body that rotates integrally with a valve opening/closing camshaft, and a lock mechanism that locks the relative rotation phase at a locked phase is provided. During start-up of the internal combustion engine, a controller starts fluid-filling control for filling the advancing chamber and the retarding chamber with a fluid, and performs unlock control for releasing a locked state of the lock mechanism before filling of the fluid by the fluid-filling control is completed.

Methods and systems are described for an engine with a cam torque actuated variable cam timing phaser. Phaser positioning control is improved by reducing inaccuracies resulting from inadvertent spool valve and/or phaser movement when the spool valve is commanded between regions. In addition, improved spool valve mapping is used to render phaser commands more consistent and robust.

A control device, which is applied to an in-vehicle internal combustion engine equipped with an intake valve variable timing mechanism that varies the valve timing for an intake valve, and which intermittently operates the in-vehicle internal combustion engine by automatically stopping/restarting the engine, wherein the electronic control unit does not permit the engine operation to be automatically stopped when the intake valve variable timing mechanism malfunctions at an operating position closer to the advanced angle than the operating position for the most retarded angle of the variable range for the valve timing of intake valve, and thus preventing increased engine vibration and misfires when the engine automatically restarts, which are caused by a malfunction of the variable valve mechanism.

A slider control module, based on a mode command: selectively extends pins into one or more slider actuators of a camshaft slider. Contact between the pins and the grooves in the slider actuator(s) during rotation of a camshaft slides the camshaft slider axially along the intake camshaft. An actual mode module: determines a last stored indicator of the mode command; commands the slider control module to extend one of the pins to slide the camshaft slider and achieve the last stored indicator of the mode command; and, based on whether the one of the pins extended in response to the command, indicates that an actual mode is either: (i) the last stored indicator of the mode command; or (ii) another mode. The mode command module updates the mode command to the actual mode.

The present invention provides a variable valve mechanism of an internal combustion engine, which includes a rocker arm that is driven by a cam so as to swing to drive a valve, a switching pin that is attached to the rocker arm so as to be shifted between a first position and a second position, a shift device that shifts the switching pin from the first position to the second position, and a return spring that returns the switching pin. In the variable valve mechanism, a drive state of the valve is switched by shifting the switching pin, the rocker arm is formed to have such a dimension that one end of the switching pin is exposed while projecting outward from the rocker arm, and the return spring is externally fitted to the one end of the switching pin so as to be exposed outside the rocker arm.

Methods and systems are described for an engine with a cam torque actuated variable cam timing phaser. Phaser positioning control is improved by reducing inaccuracies resulting from inadvertent spool valve and/or phaser movement when the spool valve is commanded between regions. In addition, improved spool valve mapping is used to render phaser commands more consistent and robust.

Methods and systems are described for an engine with a cam torque actuated variable cam timing phaser. Phaser positioning control is improved by reducing inaccuracies resulting from inadvertent spool valve and/or phaser movement when the spool valve is commanded between regions. In addition, improved spool valve mapping is used to render phaser commands more consistent and robust.

A rocker arm assembly can comprise a rocker arm. A rocker shaft comprises a channel and an oil path enclosed in the rocker shaft. The oil path is configured to supply hydraulic pressure within the rocker shaft to the channel. Rotation-locking mechanism comprises a locking pin or pressure pin configured to slide in the channel. The oil path is configured to supply oil pressure to the locking pin or pressure pin within the rocker shaft. The locking pin can be configured to slide in the channel between a locked position, where the locking pin abuts a groove, and an unlocked position, where the locking pin is withdrawn into the channel. Or, a locking pin can be configured to slide in the rocker arm between a locked position abutting the locking groove and an unlocked position where the locking pin is withdrawn into the rocker arm.

Various systems and methods are described for controlling fuel injection in a variable displacement engine. One method for a deactivatable cylinder comprises, before deactivating the cylinder responsive to operating conditions, disabling a port injector and fueling the cylinder only via the direct injector. The method further comprises, when reactivating the cylinder from deactivation, enabling both the port injector and the direct injector, and injecting a higher amount of fuel via the direct injector while simultaneously injecting a lower amount of fuel via the port injector.