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.

Methods and systems are provided for a boosted engine having a split exhaust system. In one example, a method comprises directing exhaust from a first cylinder group to one or more of a pre-compressor location, a post-compressor location, and an exhaust turbine, and directing exhaust from a second cylinder group to one or more of the pre-compressor location, and the exhaust turbine. Engine efficiency and knock control may be enhanced by directing exhaust gases to different locations based on engine operating conditions.

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.

Systems and methods are provided for operating an internal combustion engine in a two-stroke mode or a four-stroke mode to achieve greater fuel efficiency and minimize emissions. The system comprises a mode-adaptable valve; a valve rocker arm to actuate opening and closing of the mode adaptable valve; a cam follower of a first cam for carrying out a two-stroke mode; a cam follower of a second cam for carrying out a four-stroke mode; and a pin to mechanically couple the valve rocker arm to the cam follower of the first cam or the cam follower of the second cam. Coupling the valve rocker arm to the cam follower of the first cam enables a two-stroke mode and coupling the valve rocker arm to the cam follower of the second cam enables a four-stroke mode.

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.

The present invention provides a variable valve mechanism of an internal combustion engine, which includes a rocker arm that includes a roller arm including a roller that rotatably abuts against a cam and a side arm provided at a side of the roller arm and that drives a valve, and a switching device that includes a switching pin and a hydraulic chamber provided inside the rocker arm and that switches a drive state of the valve by displacing the switching pin between a coupling position at which the switching pin extends between the roller arm and the side arm and a non-coupling position at which the switching pin does not extend between the roller arm and the side arm based on variations in hydraulic pressure in the hydraulic chamber. The switching pin is provided on an axis of the roller, and the hydraulic chamber is provided inside the roller arm.

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.

A castellation device comprises a shaft surrounded by three castellation members. A first castellation member is rotatably mounted on the shaft and comprises a first end and a second end opposite to the first end. A second castellation member is slidably mounted along the shaft adjacent the first end of the first castellation member. A third castellation member is mounted to the shaft adjacent the second end of the first castellation member. A bias spring is disposed between the second castellation member and the third castellation member and is configured to bias the second castellation member away from the third castellation member. Optionally, an annular shroud can enclose the three castellation members. The first castellation member is rotatable relative to the second and third castellation members between a first position and a second position.

A method of providing a rocker arm set for a valvetrain includes providing a first intake rocker arm, a second intake rocker arm and a first exhaust rocker arm. The first intake rocker arm is configured as a switching rocker arm for a first intake valve on a first cylinder. The second intake rocker arm is for a second intake valve on a second cylinder. The second rocker arm is configured to operate in a normal Otto cycle mode. The first exhaust rocker arm is provided for a first exhaust valve on the second cylinder. The first intake rocker arm operates in one of an LIVC or EIVC mode where the first intake rocker arm is configured to open or close at a different time compared to the second intake valve. The first exhaust rocker arm operates in a cylinder deactivation mode.

A method of providing a rocker arm set for a valvetrain includes providing a first intake rocker arm, a second intake rocker arm and a first exhaust rocker arm. The first intake rocker arm is configured as a switching rocker arm for a first intake valve on a first cylinder. The second intake rocker arm is for a second intake valve on a second cylinder. The second rocker arm is configured to operate in a normal Otto cycle mode. The first exhaust rocker arm is provided for a first exhaust valve on the second cylinder. The first intake rocker arm operates in one of an LIVC or EIVC mode where the first intake rocker arm is configured to open or close at a different time compared to the second intake valve. The first exhaust rocker arm operates in a cylinder deactivation mode.