A lift regulator for a variable lift valve gear has a cam contour arranged around an axis of rotation of the lift regulator for deflecting a lift adjustment of the valve gear on rotation of the lift regulator about the axis of rotation. The cam contour has a region deflecting from a resting position, a changeover region, and a region deflecting back to the resting position. A variable lift valve gear and a method for operating the variable lift valve gear are disclosed.

A lift-valve assembly, comprising a lift valve within a housing that includes a pressure segment, a mounting segment, a port segment, and a seat segment. The lift-valve assembly may receive a lift valve, and the housing including a valve seat and a biasing spring in a selectively replaceable configuration suitable for use in a conventional internal combustion engine in place of the conventional individual components, actuated by a cam actuating system, and controlling fluid communication between a combustion chamber and both intake and exhaust systems.

A variable-stroke valve drive includes a double leg spring with a first spring leg and a second spring leg in a cylinder head of an internal combustion engine and a pivot lever. The pivot lever is supported on a guideway track of a guideway by a rolling element having a pivot point and the pivot lever, by way of a control track, is supported so as to be clearance-free on an intermediate element to a charge-cycle valve. The pivot lever is pivotable by a cam of a cam shaft for adjusting a stroke and the pivot point is displaceable parallel to the guideway track by an adjustment installation for adjusting a stroke height. The double leg spring in a central region forms an intermediate leg. A respective end of the first and second spring legs is formed to be largely parallel to a longitudinal axis of the double leg spring.

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 continuously variable valve lift apparatus may include a camshaft, a cam portion on which a cam is formed and to which the camshaft is inserted, a slider housing to which the cam portion is rotatably inserted and is movable with respect to the camshaft, a control portion selectively changing the position of the slider housing, an output portion rotatable around a pivot shaft and to which a valve shoe is formed. The valve shoe drives a valve unit.

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.

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.

A spring arrangement for a variable valve drive of an internal combustion engine includes an intermediate lever, a control shaft, a control shaft roller, a working cam contour, and a spring element. The intermediate lever comprises a contact surface, a camshaft roller which bears against a camshaft, and a slot roller which bears against a slotted guide. The control shaft roller is arranged on the intermediate lever to face away from the slotted guide. The control shaft roller bears against the control shaft. The working cam contour is formed at an end of the intermediate lever opposite the camshaft roller. The spring element comprises a force component on the contact surface in the direction of the camshaft and the slotted guide, and an end leg. The spring element loads the camshaft roller against the camshaft and the slot roller against the slotted guide. The end leg bears against the contact surface.

A variable valve mechanism of an internal combustion engine includes a cam, a transmission mechanism, a first variable device that controls the transmission mechanism to continuously change at least a maximum lift amount of a lift curve indicating a lift amount of a valve that corresponds to a rotation angle of the internal combustion engine, and a second variable device that controls the transmission mechanism to continuously change at least an operation angle of the lift curve. When the lift curve lies in any condition within a predetermined range that covers all or part of a variable range of the lift curve, an absolute value of a ratio of a maximum lift amount variation to an operation angle variation for a slight change from the condition caused by the first variable device is larger than that for a slight change from the condition caused by the second variable device.

Internal combustion engine having cam actuated valves that can be controlled to facilitate the use of different air charge levels in different cylinders or sets of cylinders are described. In one aspect a first set of cylinders is operated in a skip fire manner in which the corresponding cylinders are deactivated during skipped working cycles. Cam actuated intake valves associated with a second set of cylinders are operated differently so that the air charge in the cylinders in the second set is different than the air charge in fired cylinders subject to the skip fire control. According to another aspect, an engine having cam actuated intake valves is operated in a dynamic firing level modulation mode. During the dynamic firing level modulation operation, the cam actuated intake valves are controlled in at least two different manners to such that different cylinder working cycles have different air charges.