A camshaft adjusting device, including a vane cell adjuster having a stator connectable to a crankshaft and a rotor, which is rotatably supported in the stator and connectable to a camshaft. Webs on the stator, divide an annular space between the stator and the rotor into pressure chambers, wherein the rotor has a rotor hub and vanes extending radially outward from the rotor hub, which vanes divide the pressure chambers into two groups of working chambers having a different acting direction, into each of which working chambers pressure medium flowing in or out in a pressure-medium circuit can be admitted, and a central locking device for locking the rotor in relation to the stator. The central locking device has two spring-loaded locking pins in an accommodating space, and lockable in a locking slot secured to the stator and lock in the locking slot when the rotor rotates from the direction of an early or late stop position into the locking position from different directions, wherein the locking pin forms a valve device together with the particular accommodating space, wherein the locking pin is a step pin.

This disclosure reliably causes transition to a locked state at the time of internal combustion engine deactivation and reliably causes transition to the locked state when a locking mechanism is not in the locked state at the time of internal combustion engine activation. A control valve spool is operable to a phase control position in which the supply/discharge of a fluid to/from an advance port and a retard port is controlled while the fluid is supplied to a lock releasing port, and to a lock transition position in which the supply/discharge of the fluid to/from the advance port and the retard port is controlled while the fluid is discharged from the lock releasing port. A communication path through which a portion of the fluid from a pump port is discharged to a drain port when the spool is operated to the lock transition position is formed.

A method for cleaning a continuously variable valve timing (CVVT) system for removing foreign materials includes: switching a target operating value of the CVVT system to a predetermined setting value within a set operating region and performing cleaning of the CVVT system; and determining whether a valve timing control learning request exists for the CVVT system, and, when the valve timing control learning request exists, aborting the cleaning.

A hydraulic camshaft adjuster for changing the control times of gas exchange valves of an internal combustion engine, designed as a vane cell camshaft adjuster. A control device inserted in the vane selectively opens and interrupts a flow connection between the working chambers. A locking device prevents relative motion between the rotor and the stator in that the rotor is fastened to the stator at a vane position. A switching valve, which has three working ports, a P port and a T port, can be moved into different control positions by an adjusting element,wherein in the control position, the P port communicates with the working chambers via the A port, the B port is blocked at the switching valve, and the T port communicates with the control device of the vanes via the C port. In a control position provided as a starting strategy for the switching valve the A port communicates with the P port and the working chambers, the B port communicates with the T port and the working chambers, and the C port communicates with the control device of the vanes and the T port.

A valve opening/closing timing control apparatus includes: a driving side rotational body synchronously rotating with a crankshaft of an internal combustion engine; a driven side rotational body arranged in the driving side rotational body to share a rotational axis therewith and integrally rotating with a camshaft; advanced angle and retarded angle chambers defined between the driving side and driven side rotational bodies; a lock mechanism maintaining a relative rotational phase between the driving side and driven side rotational bodies by separately biasing first and second lock members to be engaged with first and second recesses; and a fluid controller releasing the locked state by supplying a hydraulic fluid to the first and second recesses, and controlling the relative rotational phase by supplying and discharging the hydraulic fluid to the advanced angle and retarded angle chambers.

A variable valve timing control device includes a valve unit including a spool having a plurality of land portions at an outer circumference of the spool, and being formed with a drain flow path inside the spool. The valve unit allows a second pump port and a lock port to communicate with each other in a case where the spool is set at an unlock position where a lock state of a lock mechanism is released, and the valve unit closes the second pump port with the land portion of the spool and allows the lock port to communicate with the drain flow path in a case where the spool is set at a lock position where the lock mechanism is allowed to be shifted in the lock state.

A hydraulically operated camshaft phasing mechanism has two lock pins. One of the lock pins engages at an intermediate position and an end lock pin engages near one of the stops at the end of the phaser range of authority. At least one of the locking pins, preferably the end lock pin, when the vane is at an end stop position, is engaged by oil pressure and spring loaded to release when the oil pressure side of the end lock pin is vented.

A cam shaft phaser, including: a stator including stops; a rotor rotatable with respect to the stator and including a plurality vanes extending radially outward from a body; a plurality of channels, each channel passing through a respective vane included in the plurality of vanes; and a plurality of pairs of advance and retard chambers at least partially formed by the plurality of radially inwardly extending stops and the plurality of vanes. Advance and retard chambers for each pair of advance and retard chambers are separated in a first circumferential direction by a respective vane from the plurality of vanes. Each channel connects the advance and retard chambers for said each pair of advance and retard chambers. The first plurality of channels are arranged to enable fluid flow through the first plurality of channels to displace the rotor from at least one circumferential position to a mid-lock or retard-lock position.

A hydraulic camshaft adjuster (1), in particular a vane-type hydraulic camshaft adjuster, including a rotor (2) and a stator (3) which are mounted to rotate with respect to each other, a cover (10) fixed on the stator (3), including a locking receiver and at least one locking pin (11, 12) accommodated in the rotor (2), the locking pin being slidable in the axial direction and prestressed in the direction of the locking receiver, and a hydraulic channel (27, 28, 29) to apply pressure of the locking pin (11, 12) against the prestress of same, the hydraulic channel being able to be filled and emptied with a hydraulic medium via a central screw, wherein in the rotor (2) at least one additional discharge channel (37, 38, 39, 40) fluidically connected to the hydraulic channel (27, 28, 29) is formed with a discharge valve (33, 34, 35, 36), wherein preferably the discharge valve (33, 34, 35, 36) closes the discharge channel (37, 38, 39, 40) when the locking pin (11, 12) is pressurized and opens the discharge channel when the hydraulic pressure acting on the locking pin (11, 12) falls.

A system for controlling valve opening/closing timing that allows an unlocking operation to be reliably performed is configured. When extracting a lock member from a recess, a second control valve is set to an unlock position, a first control valve is set to a predetermined position, and a relative rotation phase is displaced. As a result, the relative rotation phase is displaced in a direction opposite to the direction of displacement by cam average torque from a camshaft. Afterward, by setting the first control valve to a neutral position, the relative rotation phase is displaced by the cam average torque, and when this displacement occurs, a state in which the lock member is separated from an inner wall of the recess is created, thus facilitating extraction of the lock member from the recess.