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.

A continuous variable valve duration apparatus is provided. The apparatus includes a camshaft and a cam unit on which a cam is formed. The camshaft is inserted into the cam unit. An inner wheel transmits rotation of the camshaft to the cam unit. The inner wheel is rotatably inserted in a wheel housing a housing hinge aperture parallel to the camshaft is formed on the wheel housing. A slider hinge aperture and a slider control aperture parallel to the camshaft are formed through a slider. A hinge shaft is inserted into the housing hinge aperture and the slider hinge aperture. An eccentric cam is formed on a control shaft and is inserted into the slider control aperture. A controller selectively rotates the control shaft to move the wheel housing perpendicular to the camshaft via the slider.

A variable valve duration/variable valve lift system may include a camshaft, a first cam portion including a first cam, into which the camshaft is inserted and of which a relative phase angle of the first cam with respect to the camshaft is variable, an inner bracket transmitting rotation of the camshaft to the first cam portion, a slider housing into which the inner bracket is rotatably inserted, a first rocker arm having a first end contacting the first cam, a rocker shaft to which the first rocker arm is rotatably connected, a solenoid valve configured to selectively supply hydraulic pressure, a position controller configured to selectively change a position of the slider housing, a first bridge connected to a second end of the first rocker arm and to which a first valve is connected, and a valve lift disposed within the first bridge.

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 variable valve mechanism includes a first cam and a second cam, a main arm that drives a valve when swinging, a first sub arm that swings when pressed by the first cam, a second sub arm that swings when pressed by the second cam, and a switch device. The switch device includes a first switch pin that moves between a first coupled position between the main arm and the first sub arm and a first uncoupled position, and a second switch pin that moves between a second coupled position between the main arm and the second sub arm and a second uncoupled position. Both switch pins are arranged so as to be displaced from each other in positions where these switch pins do not overlap at least during a base circle phase in which base circles of both cams act.

An internal combustion engine capable of cylinder deactivation or skip fire control in combination with variable valve lift control. One bank of cylinders can be deactivated while the air induction of the other bank of cylinders is regulated using variable valve lift control to increase engine efficiency. An internal combustion engine with two cylinder banks, where control of one cylinder bank using skip fire control can be operating at an appropriate firing fraction in combination with variable valve lift control on the other cylinder bank. A single bank of cylinders can be controlled in a skip fire manner in conjunction with variable valve lift control.

A variable valve duration system may include a camshaft, a first cam portion including a first cam, into which the camshaft is inserted and of which a relative phase angle of the first cam with respect to the camshaft is variable, an inner bracket transmitting rotation of the camshaft to the first cam portion, a slider housing into which the inner bracket is rotatably inserted, a first rocker arm having a first end contacting the first cam and a second end connected to a first valve, a rocker shaft to which the first rocker arm is rotatably connected, a solenoid valve to selectively supply hydraulic pressure, and a position controller to selectively change a position of the slider housing according to the selective supplying of the hydraulic pressure from the solenoid valve.

A variable valve mechanism includes a variable arm including a first arm and a second arm. The second arm is pivotally supported so as to be swingable by a support shaft. A position of the support shaft is a position where, during a base circle phase, in side view, a second segment connecting an axis of a roller to an axis of the support shaft is longer than a first segment connecting the axis of the roller to an axis of a camshaft, and an angle of the second segment formed with respect to a third segment connecting the axis of the roller to a swing axis of a roller arm is 60 to 120 toward the camshaft. The second arm extends from the support shaft such that a distal end portion of the second arm protrudes in between a cam and the roller.

A continuous variable valve duration system may include a camshaft, a first cam portion including a first cam, of which a relative phase angle of the first cam with respect to the camshaft is variable, an inner bracket transmitting rotation of the camshaft to the first cam portion, a slider housing on which a control slot is formed, the slider housing being rotatable around a pivot shaft, a first rocker arm including a first end contacting the first cam and a second end connected to a first valve, a rocker shaft to which the first rocker arm is rotatably connected, and onto which an eccentric shaft inserted into the control slot is formed, a duration controller configured to rotate the rocker shaft for the slider housing to move with respect to the camshaft, and an operation mode controller configured to change a position of the pivot shaft.

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.