A hydraulic oil control valve includes an outer sleeve, an inner sleeve and a spool. The outer sleeve includes: a threaded portion, which is fixed to a camshaft; a projection, which is fixed to a phase changer; and ports, which are formed at a peripheral surface of the outer sleeve between the threaded portion and the projection. The inner sleeve includes: ports, which are communicated with the ports of the outer sleeve; an oil port; an axial groove; and an enlarged diameter portion, which is located on one side of the projection where an insertion opening of the outer sleeve is placed. The spool includes: land portions, which are configured to slide along an inner peripheral surface of the inner sleeve and are located at an outer periphery of the spool at a location that is on another side of the projection where the threaded portion is placed.

A phase adjuster is disclosed herein that has improvements for a number of features thereby improving the functionality of the phase adjuster and/or simplifying the manufacturing or assembly process for the phase adjuster. The phase adjuster includes an input gear and an input shaft connected to the input gear such that the input shaft is rotationally connected to the input gear and configured to be axially displaced. A piston plate is integrally formed with the input shaft. An output gear hub is operatively connected to the input shaft via the piston plate, and an output gear ring is connected to the output gear hub.

A hydraulic oil control valve includes a sleeve, a spool and a spring. The spool is received at an inside of the sleeve and is configured to be reciprocated. The spring is configured to be seated against a spring seat of the sleeve and is configured to apply a preload to the spool. The sleeve has a stepped portion, which has a spool contact surface for limiting movement of the spool toward the spring seat, and a protrusion, which is located at a center of the spring seat and protrudes toward an opening of the sleeve. The protrusion has a sloped peripheral surface. The protrusion is configured such that in a state where an end portion of the spring is not seated against the spring seat while the spring is placed adjacent to the spring seat, the end portion of the spring contacts the protrusion.

A hydraulic oil control valve is coaxially disposed with a rotational axis of a valve timing adjustment device. The hydraulic oil control valve includes a sleeve and a spool that is slidably moved in an axial direction within the sleeve in a radial direction. The sleeve includes an inner sleeve disposed radially outside of the spool and an outer sleeve defining an axial hole extending in the axial direction. The inner sleeve is inserted into the axial hole. The outer sleeve is fixed to an end portion of one shaft when an axial force is applied to the outer sleeve in the axial direction. An inner sleeve end portion of the inner sleeve in the axial direction away from the actuator protrudes from the outer sleeve away from the actuator in the axial direction.

A hydraulic oil control valve is coaxially disposed with a rotational axial of a valve timing adjustment device. The hydraulic oil control valve includes a sleeve, a spool slidably moving in an axial direction within the sleeve, and a filter member configured to capture foreign matters contained in the hydraulic oil. The sleeve includes an inner sleeve and an outer sleeve defining therein an axial hole extending in the axial direction. A space between the axial hole and the inner sleeve in a radial direction serves as a hydraulic oil supply passage. The filter member is disposed in the space to overlap with at least one of internal members in the inner sleeve when viewed in the radial direction.

A hydraulic oil control valve is coaxially disposed with a rotational axis of a valve timing adjustment device. The hydraulic oil control valve includes a sleeve and a spool sliding in an axial direction within the sleeve. The spool has an inner space serving as a drain passage through which the hydraulic oil discharged from a phase shifting portion flows. The spool defines a drain inlet that guides the hydraulic oil discharged from the phase shifting portion into the drain passage. At least one of the sleeve or the spool defines an opening through which the hydraulic oil in the drain passage is discharged from the hydraulic oil control valve. A protrusion is formed between the drain inlet and the opening to extend radially inward beyond the drain inlet.

A central valve for a camshaft adjuster, and to an internal combustion engine, which includes a camshaft, a camshaft-adjusting device, and a central valve. The central valve includes a shaped part as a valve housing (3), including a control piston (4) guided coaxially within the valve housing (3) in such a way that the control piston can move axially and including a stop, which limits the mobility of the control piston in an axial direction (piston stop). The piston stop is a piston stop washer (5), wherein the piston stop washer and the valve housing (3) are joined.

A valve timing control device, in effect a cam phaser, for an internal combustion engine. The valve timing control device includes a rotor connected to a camshaft and having a plurality of vanes. A stator is engaged with the rotor, and includes a plurality of webs. Pressure chambers are provided between each of the webs and vanes. The cam phaser is configured to automatically locate to its mid-lock position, without having to rely on electronic control. At least one embodiment of the present invention is configured to use cam torque to recirculate oil from one side of the vanes of the rotor to the other.

An electromagnetic valve has: a coil; a casing encircling the coil and having a cylinder portion and nail portions; a movable core moving axially in the wound coil; a fixed core set at an opening end of the casing; a valve body fixed to the opening end of the casing together with the fixed core by bending inwards the nail portions; and a spool valve body moving axially in the valve body. The nail portion is provided with a wide width portion at a root side, a narrow width portion at a top side and a stepped portion between the wide width portion and the narrow width portion. The stepped portion is positioned at a substantially same position as an outer edge of one end portion of the valve body, or positioned at a cylinder portion side with respect to the one end portion outer edge of the valve body.

When a lock demand of a camshaft phase occurs, a control mode of a hydraulic control valve is switched to a locking mode after the camshaft phase is controlled to a lock phase, and a lock pin is moved to a lock position. The camshaft phase is locked at the lock phase, and timing advance and timing retard chambers communicate with each other through a back space. In this state, a locking time filling control is executed. In the locking time filling control, the control mode of a hydraulic control valve is switched to a filling mode, the hydraulic oil is supplied to a timing advance chamber, both of the timing advance chamber and the timing retard chamber are filled with the hydraulic oil, the back space is filled with the hydraulic oil, and thereafter the control mode of the hydraulic control valve is returned to the locking mode.