A valve mechanism for an engine includes a camshaft, a rocker arm, a synchronization cam that rotates in synchronism with a valve driving cam, and a switch assembly that switches the driving state of an intake valve or an exhaust valve when a cam follower is pressed by the synchronization cam. The synchronization cam presses the cam follower at a time when the intake valve or the exhaust valve is closed. The switch assembly includes a switch unit that switches the driving state when a switch moves, a driver that drives the switch via a transmission, and a positioner including a spring-biased presser that engages with a concave portion of the transmission. The concave portion includes a first concave portion with which the presser engages in a first driving state, and a second concave portion with which the presser engages in a second driving state.

A control shaft of a cam shaft adjustment unit has axially spaced adjustment cams, which are designed in a first axial section of the control shaft for a continuous operation of a cylinder and in a second axial section for a cylinder shut-off. The adjustment cams for the continuous operation of a cylinder have, over the entire circumference of the cam circle, a radial extension which is greater than a zero stroke extension and the adjustment cams for the cylinder shut-off have, around their circumference, a shut-off section of the cam circle with a radial extension which is less than or equal to the zero stroke extension. The control shaft has a stop that reduces the rotation in both circumferential directions and functions as the calibration point for an engine electronics system.

An internal combustion engine includes: a head cover covering a cylinder head; and a variable valve actuation mechanism. The variable valve actuation mechanism includes: a cam placed inside the head cover and rotating with a camshaft extending in a rotation axis direction; and an intermediate arm placed inside the head cover and sandwiched between the cam and a rocker arm. A pair of side through-holes, which are provided for a support rod supporting the intermediate arm to pass through, are formed in side portions of the head cover so as to face each other along the rotation axis direction.

The present disclosure relates to a variable valve drive for a lifting valve, in particular for a charge-exchange valve of an internal combustion engine, which is periodically movable between a closed position and an open position indirectly by way of a cam via a rocker lever. The variable valve drive includes a switchable rocker lever arrangement for the actuation of the lifting valve, having a transmission rocker lever and a valve rocker lever which are mounted pivotably on different rocker lever axles which are each parallel to the camshaft axis.

A valve train may include a camshaft having first and second slide guides, first and second cams mounted axially adjacent in torque-proof manners on the camshaft, and a cam follower adjustable between a first position, in which the cam follower is drivingly connected with the first cam, and a second position, in which the cam follower is drivingly connected with the second cam. The valve train may also include an adjustment arrangement having adjustable mechanical first and second engagement elements for axially adjusting the cam follower between first and second positions. Each engagement element may be adjustable between basic positions, in which no contact exists with a respective one of the slide guides, and switching positions, in which the respective engagement element cooperates with the slide guide. Each engagement element may have a spring that prestresses it into the switching position. The valve train may further include an arresting device and an actuator for each engagement element, wherein the arresting device, when in a locked position, holds the associated engagement element in the basic position, and the actuator releases the arresting device.

A valve train may include a camshaft, a cam follower, and first and second cams mounted axially adjacent in a torque-proof manner on the camshaft. The valve train may also include an adjustment arrangement having adjustable first and second mechanical engagement elements, which may each cooperate with at least one slide guide arranged on the camshaft. The valve train may further include a control shaft or control slide forming a stop for the first and second engagement elements and adjusting the first and second engagement elements into respective switching positions. The cam follower may be drivingly connected with the first and second cams in first and second positions, respectively. The first and second engagement elements may each be adjustable between respective basic positions, in which no contact exists with the associated slide guide, and the respective switching positions, in which the respective engagement element cooperates with the associated slide guide.

A variable valve mechanism of an internal combustion engine includes a cam, a transmission mechanism, a first variable device that controls the transmission mechanism to continuously change at least a maximum lift amount of a lift curve indicating a lift amount of a valve that corresponds to a rotation angle of the internal combustion engine, and a second variable device that controls the transmission mechanism to continuously change at least an operation angle of the lift curve. When the lift curve lies in any condition within a predetermined range that covers all or part of a variable range of the lift curve, an absolute value of a ratio of a maximum lift amount variation to an operation angle variation for a slight change from the condition caused by the first variable device is larger than that for a slight change from the condition caused by the second variable device.

The present disclosure relates to a variable valve train for an internal combustion engine. The variable valve train has a camshaft with a cam and a rocker arm for activating at least one gas exchange valve of the internal combustion engine. The variable valve train has a swivelling lever element, in particular a swivelling lever gate, which has a support surface and a cam follower. The support surface is operatively connected, in particular in contact, with the rocker arm, and the cam follower follows a cam contour of the cam. The variable valve train has a first lever arm, which pivotably mounts the swivelling lever element, and is connected with a driven swivelling shaft for swivelling around a longitudinal axis of the swivelling shaft.

A continuously variable valve lift system includes a driving swing arm, a camshaft, a valve structure, a control shaft and an adjusting swing arm. The valve structure includes a roller rocker arm and a valve connected to the roller rocker arm. The driving swing arm has a driving arc surface. The driving arc surface contacts with the roller rocker arm to drive the valve to perform a reciprocating movement. The driving swing arm is sleeved on the control shaft and is capable of swinging around the control shaft. The control shaft is provided with a mounting part. The adjusting swing arm is connected to the mounting part and is capable of swinging relative to the mounting part. The adjusting swing arm is disposed between the camshaft and the driving swing arm. Two sides of the adjusting swing arm are contacted respectively with the camshaft and the driving swing arm.

A valve actuating device for variable valve control wherein at least one articulation point between a valve lever and a gas exchange valve, or a force transmission element which acts on the gas exchange valve, is adjustable by way of an adjusting device which includes a piston displaceably mounted in the valve lever, a piston rod which is connected to the piston is connected in an articulated manner at a first articulation point to a first end of a push rod whose second end is connected in an articulated manner at a second articulation point to the gas exchange valve, or the force transmission part which acts on the gas exchange valve, the first articulation point being displaced in the longitudinal direction of the piston rod at least between a first position and a second position.