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.

The present disclosure relates to a cam phase adjuster that includes a stator, a rotor, a front cover and at least one locking pin . The cam phase adjuster is provided with a plurality of compartments formed between the rotor and the stator, and each compartment is divided into advance cavities and retard cavities in a circumferential direction; each locking pin is mounted in a corresponding mounting hole of the rotor, an end portion of each locking pin that faces away from the front cover abuts against the bottom of the corresponding mounting hole by means of a corresponding elastic reset member; an end face of the front cover that faces the rotor is provided with at least one locking groove which matches the at least one locking pin; the end portion of each locking pin that faces the front cover can be axially inserted into the corresponding locking groove; and the front cover is provided with an unlocking flow channel which fluidly connects the corresponding locking groove to one advance cavity or retard cavity.

A valve opening and closing timing control device includes: a drive-side rotary body rotating synchronously with a crankshaft; a driven-side rotary body arranged coaxially with the drive-side rotary body and rotating integrally with a valve opening and closing camshaft; a fluid pressure chamber defined between the drive-side and driven-side rotary bodies; advance and retard chambers defined by partitioning the fluid pressure chamber; an intermediate lock mechanism selectively switches between a lock state and a lock release state; advance and retard flow paths allowing a flow of the working fluid to be supplied to and discharged from the advance and retard chambers; a control valve including a spool; and a phase control unit moving a position of the spool by controlling a power supply amount to the control valve to supply and discharge the working fluid to and from the advance and retard chambers to displace a relative rotation phase.

A control device for an internal combustion engine includes an internal combustion engine and a valve opening-closing timing control device. The valve opening-closing timing control device has a phase adjustment mechanism for setting a relative rotation phase of a driving-side rotator and a driven-side rotator. The phase adjustment mechanism overlaps a timing of opening an intake valve with a timing of opening an exhaust valve, by setting, in a predetermined period, the relative rotation phase such that the exhaust valve closes after a top dead center position has been reached, and a bypass passage is provided that connects an exhaust passage of one cylinder that is in an exhaust process to the exhaust passage of another cylinder that is in an intake process at the same time as the exhaust process.

A press-fit member having a cylindrical shape is press-fit into a through hole formed in a vane. An advance-side lock pin and a retard-side lock pin are provided coaxially with each other inside the press-fit member. In the outer circumferential surface of the press-fit member, an advance-side lock pin-release oil passage for applying lock pin-release hydraulic pressure to an advance-side engagement groove and a retard-side lock pin-release oil passage for applying the lock pin-release hydraulic pressure, applied to the advance-side engagement groove, to a retard-side engagement groove are formed.

A valve opening and closing timing control device includes: a drive-side rotary body rotating synchronously with a crankshaft; a driven-side rotary body arranged coaxially with the drive-side rotary body and rotating integrally with a valve opening and closing camshaft; a fluid pressure chamber defined between the drive-side and driven-side rotary bodies; advance and retard chambers defined by partitioning the fluid pressure chamber; an intermediate lock mechanism selectively switches between a lock state and a lock release state; advance and retard flow paths allowing a flow of the working fluid to be supplied to and discharged from the advance and retard chambers; a control valve including a spool; and a phase control unit moving a position of the spool by controlling a power supply amount to the control valve to supply and discharge the working fluid to and from the advance and retard chambers to displace a relative rotation phase.

A control device for an internal combustion engine includes an internal combustion engine and a valve opening-closing timing control device. The valve opening-closing timing control device has a phase adjustment mechanism for setting a relative rotation phase of a driving-side rotator and a driven-side rotator. The phase adjustment mechanism overlaps a timing of opening an intake valve with a timing of opening an exhaust valve, by setting, in a predetermined period, the relative rotation phase such that the exhaust valve closes after a top dead center position has been reached, and a bypass passage is provided that connects an exhaust passage of one cylinder that is in an exhaust process to the exhaust passage of another cylinder that is in an intake process at the same time as the exhaust process.

An ECU (101) causes lock pin-release hydraulic pressure to be applied to an advance-side lock pin-release oil passage (5a) to disengage an advance-side lock pin (6) from an advance-side engagement groove (9), thereby making a rotor (1) rotatable in an advance direction, and forming a clearance communicating with a retard-side lock pin-release oil passage (5c), between the advance-side engagement groove (9) and the advance-side lock pin (6). Next, the ECU (101) causes hydraulic pressure to be applied to advancing hydraulic chambers (16) to rotate the rotor (1), and causes the lock pin-release hydraulic pressure to be applied through the clearance and through the retard-side lock pin-release oil passage (5c) to a retard-side engagement groove (10) to disengage a retard-side lock pin (7).

A press-fit member having a cylindrical shape is press-fit into a through hole formed in a vane. An advance-side lock pin and a retard-side lock pin are provided coaxially with each other inside the press-fit member. In the outer circumferential surface of the press-fit member, an advance-side lock pin-release oil passage for applying lock pin-release hydraulic pressure to an advance-side engagement groove and a retard-side lock pin-release oil passage for applying the lock pin-release hydraulic pressure, applied to the advance-side engagement groove, to a retard-side engagement groove are formed.

The disclosure relates to a hydraulic camshaft adjuster for the variable adjustment of the control times of gas exchange valves of an internal combustion engine, having a stator and a rotor rotatable relative to the stator. Radially inwardly projecting webs are formed on the stator and radially outwardly projecting vanes are formed on the rotor. Between the stator and the rotor are formed several hydraulic working chambers, each of which is divided into a first working chamber and a second working chamber by a vane of the rotor. Two locking elements are inserted into the rotor for the temporary, reversibly detachable fixing of the rotor relative to the stator in a middle position. The first locking element and the second locking element can be locked in a common locking slotted guide. The disclosure also relates to a method for locking of the rotor in such a hydraulic camshaft adjuster.