There is provided a variable valve timing system for an engine in which a cylinder head is fixed on a cylinder, and the cylinder head is suspended on a vehicle body frame, the variable valve timing system including: a variable valve device configured to change an opening and closing timing of a valve according to a hydraulic pressure; and an oil control valve. The vehicle body frame includes a main frame configured to laterally cover a rear side of the cylinder head and a down frame configured to laterally cover a front side of the cylinder head. In a side view of a vehicle, the oil control valve is detachably disposed on an outer surface of the engine below an area surrounded by the main frame, the down frame, and a lower surface of the cylinder head.

There is provided a variable valve timing system for an engine in which a cam chain chamber is formed in a cylinder and a cylinder head, the variable valve timing system including: a variable valve device configured to change an opening and closing timing of a valve; and an oil control valve configured to control a hydraulic pressure with respect to the variable valve device. The oil control valve is disposed on an outer surface of the cylinder, which is an outer wall of the cam chain chamber. An oil path for hydraulic pressure control enters the outer wall of the cam chain chamber from the oil control valve, extends from a side of the cylinder to a side of the cylinder head, and crosses the cam chain chamber to the variable valve device through an inner wall of the cam chain chamber.

A method of two-step variable valve lift (VVL) malfunction avoidance learning control may include: in a two-step VVL system which is operated with a main lift and a secondary lift, verifying, by an electronic control unit (ECU), an operation avoidance area based on locking of a lock pin of a cam follower ; performing VVL operation learning, in which a failure of occurrence of the second lift is determined on the basis of a locking failure of the cam follower due to an initially set value of the operation avoidance area; and reflecting the operation avoidance area to the two-step VVL system with a corrected set value which is obtained through the VVL operation learning.

A continuous variable valve duration apparatus includes a cam unit, a cam formed on the cam unit, a camshaft inserted into the cam, a guide bracket, a guide shaft mounted on the guide bracket and disposed perpendicular to the camshaft, wherein a guide screw thread is formed on the guide shaft, a wheel housing disposed within the guide bracket, an inner wheel rotatably inserted into the wheel housing and movable perpendicular to the camshaft, a worm wheel disposed within the wheel housing, wherein an inner screw thread configured to engage with the guide screw thread is formed inside the worm wheel and an outer screw thread is formed on the worm wheel, a control shaft, a control worm formed on the control shaft, and a wheel elastic portion mounted to the wheel housing.

The present invention refers to a charge changing control device for a reciprocating engine, comprising at least one cam follower configured for being pivotably actuated around a pivot axis (P) upon rotational movement of a camshaft, and an adjustment unit configured for setting at least three different charge-changing modes of the device by translationally displacing the pivot axis relative (P) to a rotational axis (R) of the camshaft.

There is provided a variable valve timing system for an engine in which a cam chain chamber is formed in a cylinder and a cylinder head, the variable valve timing system including: a variable valve device configured to change an opening and closing timing of a valve; and an oil control valve configured to control a hydraulic pressure with respect to the variable valve device. The oil control valve is disposed on an outer surface of the cylinder, which is an outer wall of the cam chain chamber. An oil path for hydraulic pressure control enters the outer wall of the cam chain chamber from the oil control valve, extends from a side of the cylinder to a side of the cylinder head, and crosses the cam chain chamber to the variable valve device through an inner wall of the cam chain chamber.

An automobile vehicle overhead camshaft system includes multiple camshafts individually having multiple sliding camshaft barrels. Opposed ends of the camshaft barrels individually have a zero-lift lobe. Multiple intake valves are operated by a first one of the camshafts and multiple exhaust valves are operated by a second one of the camshafts. Multiple actuators operate during a deceleration cylinder cut-off (DCCO) mode to slidably displace the camshaft barrels to position the zero-lift lobe of predetermined ones of the multiple sliding camshaft barrels into contact with at least one of: all of the intake valves; or all of the exhaust valves.

A cam phasing mechanism (1) for a cam assembly (100) of an internal combustion engine, the cam assembly (100) comprising a camshaft (120) and an actuator (130) for opening a valve (505) at a reference position of rotation of the camshaft (120), the cam phasing mechanism (1) comprising: a force transfer member (2a) for interposition between the camshaft (120) and the actuator (130) of the cam assembly (100) for transferring force between the camshaft (120) and the actuator (130); and an adjuster (2b) for selectively moving the force transfer member (2a) to adjust the reference position of rotation of the camshaft (120).

An electro-mechanical variable valve mechanism includes a variable valve mechanism body, a latching pin arranged in front of the variable valve mechanism body, and an inner body arranged inside the variable valve mechanism body. The latching pin reciprocates in a longitudinal direction of the variable valve mechanism body and the inner body to latch the variable valve mechanism body and the inner body.

A valvetrain for an internal combustion engine has a camshaft rotatable about an axis of rotation, a sliding-block element connected in a rotationally fixed manner to the camshaft and displaceable in the axial direction of the camshaft relative thereto, which sliding-block element has an outer circumferential jacket surface with a shift gate via which a rotational movement of the sliding-block element can be converted into a displacement of the sliding-block element in the axial direction of the camshaft relative thereto, and a shift rod at least partially accommodated in the camshaft and displaceable by the sliding-block element in the axial direction of the camshaft relative thereto and via which shift rod an actuation of a gas exchange valve can be influenced.