A hydraulic camshaft adjuster (1), in which the locking system (7, 8) includes a first and a second control element (7, 8). In order to approach the middle position easily, the first control element (7) has a first and a second switching position, wherein in the first switching position a fluidic connection between the hydraulic pump (P) and a first of the two sub-chambers (B) and a fluidic connection between the other, second sub-chamber (A) and the tank (T) can be established, and in the second switching position a fluidic connection between the hydraulic pump (P) and the second of the two sub-chambers (A) and a fluidic connection between the other, first sub-chamber (B) and the tank (T) can be established, and the second control element (8) is free from different switching positions and has no influence on the flow of hydraulic fluid.

A camshaft phaser includes a stator having an inner wall with lobes extending radially inward and a stator flange extending radially outward, the stator flange having a plurality of apertures; a rotor coaxially disposed within the stator, the rotor having vanes interspersed with the lobes defining alternating advance chambers and retard chambers; a plurality of compression limiters extending through the apertures; a front cover which closes one end of the advance and retard chambers; a back cover which closes the other end of the advance and retard chambers; and a plurality of fasteners which extend through the apertures such that the fasteners apply a clamping load which clamps the stator between the front cover and the back cover such that the clamping load is transmitted through the compression limiters.

The present disclosure provides a CVVT system including: an OCV supplying oil received from a cylinder block into a CVVT; an oil supply unit supplying oil from the OCV to a lock pin; and an actuator selectively opening or closing the oil supply unit such that oil is supplied to the lock pin and the lock pin is separated from a lock pin hole when the oil supply unit is opened.

A valve opening/closing timing control apparatus includes: a driving side rotating body rotating synchronously with a crankshaft of an internal combustion engine; a driven side rotating body included in the driving side rotating body and rotating integrally with a camshaft on a same axis as a rotation axis of the driving side rotating body; a hydraulic fluid control mechanism displacing a relative rotation phase between the driving side rotating body and the driven side rotating body by supplying a hydraulic fluid to one of an advance angle chamber and a retardation angle chamber; a lock mechanism; and first and second unlocking flow paths configured to communicate with the first pressure receiving surface. The lock mechanism includes a lock member including an engaging portion, a main body portion, and a first pressure receiving surface a biasing member, and a lock recess.

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 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.

A valve opening/closing timing control device includes: an intermediate lock mechanism switchable between a locked state constraining a relative rotation phase to an intermediate locked phase, and an unlocked state releasing the constraint; a phase control unit controlling fluid supply to a retard chamber and fluid discharge from an advance chamber, or controlling fluid discharge from the retard chamber and fluid supply to the advance chamber, such that the lock member attains the intermediate locked phase; and a determination unit determining whether the lock member will attain the determination phase, when control has been performed to move the lock member toward a determination phase that has been set at a different position than the intermediate locked phase, after execution of control to either supply fluid to the retard chamber and discharge fluid from the advance chamber, or discharge fluid from the retard chamber and supply fluid to the advance chamber.

A camshaft adjusting device including a vane cell adjuster with a stator which can be connected to a crankshaft of an internal combustion engine and with a rotor which is rotatably mounted in the stator and can be connected to a camshaft. The camshaft adjusting device also includes a central locking device for locking the rotor in a central locking position relative to the stator. In one or more of the vanes together: at least two pressure medium lines are provided, each of which fluidically connects two working chambers with different working directions to each other. Non-return valves with different working directions are provided in each pressure medium line, each non-return valve allowing a flow of the pressure medium between the working chambers in one direction and preventing the flow in the respective other direction depending on the rotational direction of the rotor relative to the stator. A first switchable valve device is provided in the respective other vanes which are not provided with non-return valves, the valve device allowing a flow of the pressure medium between the working chambers with different working directions in one switch position.

A valve opening/closing timing control device includes a driving rotating body that rotates in synchronization with a crankshaft, a driven rotating body that rotates integrally with a camshaft, a phase detection mechanism that detects the relative rotation phase of the driving rotating body and the driven rotating body, a retarding chamber and an advancing chamber between the driving rotating body and the driven rotating body, a lock mechanism capable of constraining the relative rotation phase to a lock phase, a supply/discharge mechanism that supplies/discharges working fluid to/from the advancing chamber, the retarding chamber, and the lock mechanism, and a control unit that controls operation of the supply/discharge mechanism. At startup of the engine, if the detected relative rotation phase is not at the lock phase, the control unit controls the supply/discharge mechanism so as to stop successive supply of working fluid to the retarding and advancing chambers.

A valve timing control apparatus has a regulation member to fix a phase. The regulation member has a main regulation member and a sub regulation member. The main regulation member is inserted into a recess part to regulate the phase. The sub regulation member has an engagement part engageable with the main regulation member in an escape direction Y and disengageable from the main regulation member in an insertion direction X. Further, the sub regulation member has a pressure reception part that receives pressure in the escape direction Y from hydraulic fluid in an operation chamber. The main regulation member is urged in the insertion direction X by a main resilient member. Further, the sub regulation member is urged in the insertion direction X by a sub resilient member. The main regulation member moves in the escape direction Y only by hydraulic fluid, and moves in the insertion direction X only by the resilient member.