A continuous variable valve duration apparatus may include a camshaft, a plurality of wheels mounted to the camshaft, of which a wheel key is formed thereto respectively, a plurality of cam portions of which a cam and a cam key are formed thereto respectively, of which the camshaft is inserted thereto, of which relative phase angle with respect to the camshaft is variable, a plurality of inner brackets connected with the each wheel key and the each cam key, a plurality of slider housings of which the each inner bracket is rotatably inserted thereto, and movable up and down direction of an engine, a control portion selectively moving the slider housings to adjust relative position of a rotation center of the inner brackets and a guider guiding movement of the sliding housings.

A method of manufacturing a cam piece for a continuously variable valve duration and a cam piece manufactured therefrom, and more particularly, to material and heat treatment conditions of a cam piece, may include manufacturing a cam piece by casting; heating the cam piece; maintaining a heating temperature; and salt-bathing the cam piece, in which the cam piece includes 3.2 to 4.2 wt % of carbon (C), 2.2 to 3.4 wt % of silicon (Si), and the balance iron (Fe), and may have a carbon equivalent value of 4.4 to 4.6.

A system according to the present disclosure includes a cylinder deactivation module and a valve lift control module. The cylinder deactivation module selectively deactivates a first cylinder of an engine while a second cylinder of the engine is active. When the first cylinder is deactivated, the valve lift control module selectively adjusts a target lift state of a valve actuator of the engine to a first lift state to lift at least one of an intake valve of the second cylinder and an exhaust valve of the second cylinder by a first amount. The valve lift control module selectively adjusts the target lift state of the valve actuator to a second lift state to lift at least one of the intake valve and the exhaust valve by a second amount. The first and second amounts are greater than zero and the second amount is greater than the first amount.

A rocker arm mechanism capable of selectively adjusting a timing of opening or closing an intake or an exhaust valve of a plurality of exhaust valves by shifting according to a crankshaft angle and by gradually changing a maximum valve opening, or electively, allows for engine braking by decompression by opening the plurality of exhaust valves before a compression stroke in a plurality of internal combustion engines.

A continuous variable valve timing apparatus may include a camshaft, a cam device on which a cam is formed respectively and of which the camshaft is inserted thereto, wherein a relative phase angle with respect to the camshaft is variable, an inside bracket configured to transmit rotation of the camshaft to the cam device, a lifter in which the inside bracket is rotatably inserted therein and on which a cylinder opening and a shaft opening are formed thereon, a control shaft parallel to the camshaft and to which a control rod, inserted into the shaft opening, is eccentrically formed, a control cylinder on which a control rod opening where the control rod is inserted therein is formed and inserted into the cylinder opening, a guide portion guiding movement of the lifter and a controller selectively rotating the control shaft, wherein the lifter may move.

A continuous variable valve duration apparatus includes a camshaft, a first and second cam portion, each including a cam and a cam key, where the camshaft is inserted into the first and second cam portions and where relative phase angles with respect to the camshaft are variable, a first and second inner bracket transmitting a rotation of the camshaft to the first and second cam portions respectively, a first and second slider housing, a cam cap rotatably supporting the first and second cam portions respectively, a slider pin rotatably inserted into the first sliding hole and slidably inserted into the camshaft, a cam pin on which a cam key slot for the cam key to be slidably inserted thereinto is formed, a control shaft disposed parallel to the camshaft and engaged with the first and second slider housings, and a control portion selectively rotating the control shaft.

A continuous variable valve duration apparatus may include a camshaft, a cam device, of which the camshaft is inserted thereto, of which a phase angle with respect to the camshaft is variable, and the cam device on which a cam key is formed, an inside bracket transmitting rotation of the camshaft to the cam device and on which a first slide opening and a second sliding opening are formed respectively, a slider housing in which the inside bracket is rotatably inserted and of which relative position with respect to the camshaft is variable, a controller selectively changing the relative position of the slider housing, a cam pin of which a cam key opening for the cam key to be slidably inserted thereto is formed and slidably inserted into the second sliding opening and a slider pin rotatably inserted into the first sliding opening and slidably inserted into the camshaft.

A switchable rocker arm for valve deactivation is provided for a valve train of an internal combustion engine. The switchable rocker arm includes a valve side lever assembly, a cam side lever assembly, and a hydraulically actuated coupling assembly. The valve side lever assembly includes a first housing with a first rocker shaft bore. The cam side lever assembly includes a second housing with a first arm with a second rocker shaft bore and a second arm with a third rocker shaft bore. The first and second arms extend along opposed longitudinal sides of the cam side lever assembly such that the first, second and third rocker shaft bores are axially aligned. The coupling assembly is arranged at an end furthest away from a pivot axis for minimal loading and provides locking and unlocking of the switchable rocker arm to achieve full valve lift and no valve lift modes, respectively.

Start-up of an internal combustion engine comprises maintaining one or more engine valves in an engine cylinder in a continuously open state for more than one engine cycle during engine cranking. When it is determined that an engine parameter or transmission oil pressure has reached a predetermined value, maintenance of the one or more engine valves in the continuously open state is discontinued and fuel is subsequently provided to the engine cylinder for engine start-up. In various embodiments, the engine parameter may comprise an engine temperature parameter, an engine pressure parameter or an engine electrical parameter.

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.