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 control method for a continuously variable valve lift mechanism includes: controlling a continuously variable valve lift mechanism to enter a limp mode when the continuously variable valve lift mechanism fails and disables an automatic valve lift changing function; driving and forcing the continuously variable valve lift mechanism to move to a maximum lift position; and triggering a self locking function to self lock the continuously variable valve lift mechanism at the maximum lift position when the continuously variable valve lift mechanism reaches the maximum lift position. A control system for a continuously variable valve lift mechanism, and a vehicle are also provided.

A camshaft assembly for a vehicle valvetrain having first and second engine valves includes a camshaft, and a first camshaft cartridge axially displaceable along the camshaft and including a plurality of first cam lobes configured to selectively impart movement to the first engine valve. A second camshaft cartridge is axially displaceable along the camshaft and includes a plurality of second cam lobes configured to selectively impart movement to the second engine valve. An actuator is configured to axially displace the first camshaft cartridge along the camshaft. A coupling is between the first camshaft cartridge and the second camshaft cartridge. Axial displacement of the first camshaft cartridge selectively imparts movement to the second camshaft cartridge for axial displacement of the second camshaft cartridge.

Methods and systems are provided for a valve lift control device. In one example, a method may include rotating an adjusting camshaft of the valve lift control device in order to adjust a valve lift of one or more cylinders.

An abnormality diagnosis system of an internal combustion engine that is installed on a vehicle and includes an actuator includes an electronic control unit. The electronic control unit receives vehicle outside information concerning a period of time for which the vehicle speed is less than a predetermined value, and determines whether the period for which the vehicle speed is less than the predetermined value is expected to be equal to or longer than a length of time required for an abnormality diagnosis of an abnormality diagnosis target device. The electronic control unit activates the actuator and starts the abnormality diagnosis as the vehicle speed becomes lower than the predetermined value, when it determines that the period for which the vehicle speed is lower than the predetermined value is expected to be equal to or longer than the time required for the abnormality diagnosis of the target device.

A variable valve drive for a lifting valve, such as a charge-exchange valve of an internal combustion engine, that is periodically movable between closed and open positions 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 parallel to the camshaft axis. The valve rocker lever, is in operative contact with the lifting valve at a first end, and has a roller, at a second end. The transmission rocker lever, is in engagement with a cam of the camshaft and, is operatively connected to the roller of the valve rocker lever.

A variable system of an internal combustion engine spaces a closing timing IVC of an intake valve apart from an intake bottom dead center BDC by a variable actuation valve mechanism and also increases a mechanical expansion ratio E by a variable compression ratio mechanism when an engine torque increases to around a maximum engine torque. The variable system sets the closing timing IVC of the intake valve to a closing timing IVCd spaced apart from the intake bottom dead center BDC around the maximum engine torque. Due to this control, the variable system can reduce an effective compression ratio to enhance a knocking resistance capability, and, further, achieve improvement of thermal efficiency and also reduce a temperature of exhaust gas to prevent or reduce thermal damage on an exhaust-system component by increasing the mechanical expansion ratio.

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 continuously variable valve lift system includes a driving swing arm, an adjusting member, an adjusting swing arm and a camshaft. The driving swing arm is provided with a first connecting part, the adjusting member is provided with a second connecting part, and the adjusting swing arm is provided with a third connecting part, wherein two sides of the second connecting part abut against the first connecting part and the third connecting part, respectively, the second connecting part abuts against the third connecting part to form a spiral surface therebetween, and the adjusting member is further capable of sliding along an axial direction of the middle shaft, and the camshaft contacts with the adjusting swing arm.

An internal combustion engine includes a cylinder block that defines a cylinder and a cylinder head mounted to the cylinder block. A reciprocating piston is arranged inside the cylinder for compressing an air and fuel mixture at a geometric compression ratio of at least 10:1. A crankshaft is arranged in the cylinder block and rotated by the piston. An intake valve is operatively connected to the cylinder head and controls delivery of air to the cylinder for combustion therein. A mechanism provides a constant peak lift of the intake valve over an angle of rotation of the crankshaft that is at least 5 degrees, i.e., an extended dwell at peak lift. A multi-stage boosting system having first and second gas compressors is selectively controlled to pressurize air that is received from the ambient for delivery to the cylinder. A vehicle having such an engine is also disclosed.