In a hydraulically-operated vane rotor equipped variable valve timing control device for an internal combustion engine, a fluid-communication control mechanism is configured to switch, after having started the engine, a communication hole from a communicated state to a fluid-communication restricted state prior to switching operation of a lock mechanism from a lock state in which rotary motion of a vane rotor relative to a housing is restricted to an unlock state in which rotary motion of the vane rotor relative to the housing is enabled. As a result of this configuration, it becomes possible to apply, after having started the engine, an appropriately controlled hydraulic pressure to all of vanes, with hydraulic pressure supplied to either all phase-retard chambers or all phase-advance chambers, thereby ensuring a good control responsiveness of the vane rotor.

A valve opening and closing timing control device includes: a drive-side rotary body rotating synchronously with a crankshaft; a driven-side rotary body provided inside the drive-side rotary body coaxially and rotating integrally with a camshaft; advance and retard chambers formed between the drive-side and driven-side rotary bodies; a lock mechanism switchable between a lock state and a lock release state; a valve unit including a fluid supply pipe into which fluid is supplied and a spool movable along a direction of the rotation axis, and controlling supply of the fluid to and from the lock mechanism, and the advance and retard chambers; and a tubular valve case having an internal space inside the driven-side rotary body and housing the valve unit in the internal space. A first opening portion is formed in the fluid supply pipe. A second opening portion is formed in the valve case.

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.

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 valve for a camshaft adjuster having a valve housing (3) and having a control piston (4) which is guided axially movably in a receptacle of the valve housing (3), and having a check valve (2) which is arranged within the piston cavity (22) and consists of a spring band (23) with overlapping ends which is wound to form a cylindrical valve spring, wherein the spring band (23), at the inner end (24) thereof, merges into an axially extending spacer element (28), the axial ends (29, 30) of which may be brought into contact with the inner side of the end surfaces of the control piston (4) is provided. The spacer element (28) has a uniform surface which is interrupted in an axial section of the spacer element (28) by way of an elevation (32).

A hydraulic valve for a cam phaser including a pressure balanced hollow piston that is arranged axially movable, wherein the hollow piston at its end oriented towards the pressure medium connection includes a first piston section with a first small outer diameter, and adjacent to the first piston section a second piston section with a second large outer diameter, and a third piston section with a third medium outer diameter, wherein the hollow piston includes a respective pressure surface for pressure compensation at the first piston section and at the third piston section which are respectively loadable with an axial force that is oriented away from the pressure medium connection when the hollow piston is loaded with pressure, wherein a resultant force of the axial forces impacts the hollow piston, and another pressure surface is provided at the second piston section of the hollow piston.

A valve opening and closing timing control apparatus includes a driving-side rotating body, a driven-side rotating body fixed to a camshaft by a bolt, a fluid pressure chamber, an intermediate lock mechanism, a lock flow passage bringing the working fluid to the intermediate lock mechanism, and an electromagnetic valve including a spool which is arranged at an inner portion of the bolt, the lock flow passage including a first flow passage which is arranged between the spool and a supply flow passage in a radial direction and which is connected to the supply flow passage, the lock flow passage including a second flow passage which is provided at the inner portion of the bolt in a penetrating manner in the radial direction and which brings the working fluid to flow between the spool and the intermediate lock mechanism.

[Object] Object is to provide hydraulic control valve capable of increasing flexibility of layout of ports without requiring high accuracy of dimensions of component.

[Solution] Hydraulic control valve has cylindrical valve body 50 having, at cylindrical shaft portion 50b, retard and advance ports 18a, 19a and reintroduction ports 58; spool valve 51 provided slidably in axial direction in valve body 50 and making switch between supply/discharge of working fluid to/from retard and advance hydraulic chambers 11, 12 through land portions 51a, 51b; cylindrical sleeve 52 formed with synthetic resin material and fixed to outer peripheral surface of cylindrical shaft portion 50b; and actuator 55 moving spool valve 51 in axial direction. Sleeve 52 has, at peripheral wall thereof, retard and advance oil passage holes 64a, 64b communicating with retard and advance ports 18a, 19a, and has, on inner peripheral surface thereof, communication grooves 65 communicating with reintroduction ports 58.

A valve element for a hydraulic control device, in particular valve sleeve (1) or valve housing for a control valve on internal combustion engines or transmissions of motor vehicles, wherein the valve element has a displaceable control piston (2) which is subjected to load on one side by a spring (3) which is supported on a spring support (4) which is fixed to the valve element. The spring support (4) has at least one opening (7) which is connected to a pressure medium line, and the pressure medium line is in the form of a pressure medium inlet line. An axial filter (8) is arranged at the opening (7) of the spring support (4) and/or the opening (7) of the spring support (4) is provided with a check valve (9).

A rotor for a hydraulic camshaft adjuster. The rotor includes a first rotor element and a second rotor element. At least one of the rotor elements has oil channels separated from each other by radially arranged elevations. Each elevation of the first rotor element has a first joining profile and the second rotor element forms a complementary-shaped second joining profile corresponding to the position of each first joining profile, wherein the first and the second joining profile engage with each other in the assembled rotor. The first joining profile of the first rotor element has a notch and an elevation and the second joining profile of the second rotor element has a notch and an elevation formed in such a way that prior to the joining of the two rotor elements, a height of the elevation of the second joining profile, which engages in a notch of the first joining profile, is less than a height of the notch of the first joining profile, and a height of the elevation of the first joining profile, which engages in a notch-of the second joining profile, is less than a height of the notch of the second joining profile.