An internal combustion engine is provided with a DOHC-type valve train in a cylinder head. The valve train includes an intake side camshaft with an intake side driven gear, and an exhaust side camshaft with an exhaust side driven gear. The cylinder head supports therein a spindle with an idle gear with an idle chain sprocket fixed thereto. The idle gear is in meshing engagement with both the intake and exhaust side driven gears. Rotary power of a crankshaft is transmitted via a cam chain to the idle gear to rotate both the intake and exhaust side camshafts. These camshafts are supported by bearings of a bearing wall and a camshaft holder. These bearings and camshaft holder are located, for compact arrangement, at a position axially coinciding or overlapping with the idle chain sprocket.

An engine variable valve train includes a cam changeover mechanism for axially shifting a cylindrical cam carrier fitted on and around a camshaft for changing over cam lobes on the cam carrier to cause one of the cam lobes to selectively act on an engine valve for engine operation. The cam changeover mechanism includes changeover pins adapted to be advanced and retracted for engagement with or disengagement from a lead groove formed around the cam carrier, and with a changeover driving shaft constituting a linear motion cam mechanism for causing the changeover pins to selectively advance to engage with the lead groove. The cam carrier, while rotating with the cam shaft, is axially shifted by the action of the lead groove having the changeover pins selectively engaged therewith, so that the cam lobes are changed over and one of the cam lobe is made to act on the engine valve.

A valve train for an internal combustion engine may include a camshaft and a cam follower. The valve train may also include two first cams arranged on the camshaft in a torque-proof manner and at an axial distance from one another. Each of the two first cams may include an identical first cam contour. The valve train may also include two second cams arranged on the camshaft in a torque-proof manner and at an axial distance from one another. Each of the two second cams may also include an identical second cam contour. The two first cams and the two second cams may alternate in an axial direction on the camshaft. The cam follower may be axially adjustable between a first and second position, and may be drivingly connected to the two first cams in the first position and drivingly connected to the two second cams in the second position.

A camshaft assembly includes a base shaft including at least one lobe pack axially movably mounted on the base shaft, the lobe pack including a control groove therein. An actuator device includes a pin movably mounted to the actuator between a retracted position and an extended position for engaging with the control groove to cause axial movement of the lobe pack. The control groove includes a pin engagement region, a shifting region and an ejection region. The pin engagement region of the control groove has a first pair of sidewalls. The shifting region extends from the pin engagement region and has a second pair of sidewalls angled relative to the first pair of sidewalls and having a first portion with a varying groove width that varies relative to a groove width of the pin engagement region.

A multiple variable valve lift apparatus includes a camshaft. At least two cam portions are disposed on an exterior circumference of the camshaft and including a high cam and a normal cam. A cylinder deactivation device is configured to perform a lever motion by one of the high cam or the normal cam and to be operated by hydraulic pressure. At least two lift operating portions are disposed on the exterior circumference of the camshaft and moving the cam portions in an axial direction of the camshaft. An operation control portion selectively moves the operating portions in the axial direction of the camshaft. A guide rail is formed in a groove of an exterior circumference of the lift operating portions into which a pin is inserted. The guide rail guides the pin according to rotation of the camshaft and the operating portions.

An engine braking method includes the steps of engaging a cam roller(235) of an internal combustion engine with an engine power cam(230) for an engine power operation; disengaging the cam roller(235) from the engine power cam(230); losing a motion from the engine power cam(230) and a motion of an engine valve(301) associated with the motion from the engine power cam(230); engaging the cam roller(235) with an engine braking cam(2302) for an engine braking operation; transmitting a motion from the engine braking cam(2302) to the engine valve(301); and generating an engine valve motion for the engine braking operation. An engine braking system includes an engine power cam(230) of an internal combustion engine; an engine braking cam(2302) of the internal combustion engine; and a cam roller(235) that is designed to engage with the engine power cam(230) for an engine power operation and to engage with the engine braking cam(2302) for an engine braking operation.

An electromagnetic actuating mechanism comprising an armature unit (10) which can be moved by a certain armature excursion along an axial direction of travel as a result of stationary coil means being energized, plunger means (16) which are associated with the armature unit, are designed such that the end thereof cooperates with an external actuating partner, and can be moved by a certain plunger excursion along the direction of travel from a starting position into an engagement position, and spring means (22) which bias the plunger means in the direction of travel.

A continuous variable valve duration system may include a camshaft, a cam portion having a cam is formed thereto. The camshaft is inserted to the cam portion such that a relative phase angle with respect to the camshaft is variable. The camp portion has a cam cap engaging portion, and an inner bracket transmits rotation of the camshaft to the cam portion. A slider housing has the inner bracket rotatably inserted thereto, of which relative position with respect to the camshaft is variable, and of which a control slot is formed. Cam caps rotatably mount the cam cap engaging portion to a cylinder head, and a control portion comprising an eccentric control shaft inserted into the control slot. A worm wheel is connected to the eccentric control shaft, and a worm gear engaged with the worm wheel and a control motor selectively rotates the worm gear so as to change relative position of the slider housing with respect to the camshaft and a cylinder head cover of which a motor mounting portion where the control motor is mounted thereto.

Disclosed is a control and monitoring method via H bridge of an electromagnet including a solenoid through which a current can be passed in one direction and in the opposite direction. The solenoid delivers a signal corresponding to a mechanical locking movement. Once a current flows in the solenoid, the bridge switches automatically into high impedance with all transistors thereof blocked. A measurement is then taken at the terminals of the solenoid to verify the locked state of the electromechanical system.

An engine that can implement cylinder deactivation (CDA) includes: a plurality of cylinders; a variable valve duration apparatus that is mounted in at least one of the plurality of cylinders and that performs a long duration mode and a short duration mode of an intake valve of a corresponding cylinder; a CDA apparatus that is mounted in at least another one of the plurality of cylinders and that performs a general operation mode and a CDA mode of an intake valve and an exhaust valve of a corresponding cylinder; and a controller that controls operation of the variable valve duration apparatus and the CDA apparatus according to an operation state of an engine, wherein the controller controls the variable valve duration apparatus to operate in a short duration mode, when the CDA apparatus operates in the CDA mode.