An actuation apparatus (3) for actuating a latching arrangement (40) of a switchable valve train component (2) of an internal combustion engine is disclosed. The actuation apparatus comprises a lever (33) for contacting an actuation source (100) and for contacting the latching arrangement (40), and a biasing means (31). The biasing means (31) contacts the lever (33). In use, the biasing means (31) becomes biased by the lever (33) when the actuation source moves the lever (33) when the actuation source (100) attempts to actuate the latching arrangement (40), via the lever (33), when the latching arrangement (40) is non-actuatable. The biasing means (31) causes the lever (33) to actuate the latching arrangement (40) when the latching arrangement (40) is actuatable again. Also disclosed is a valve-train assembly.

Systems and methods for managing excessive intake flow path pressure and counter flow are implemented to support enhanced engine braking applications, such as 2-stroke or 1.5-stroke engine braking implementations where the intake flow path may be exposed to excessive transient pressures in the combustion chamber during activation or deactivation of an engine brake. Intake throttle, exhaust gas recirculation (EGR) valve, intake manifold blow-off valve, compressor bypass valve, exhaust throttle, turbocharger geometry or turbocharger waste gate may be controlled to effectuate counter flow management separately or in combination. Excessive transient conditions may also be prevented or managed by sequential valve motion in which brake motion activation occurs first and then exhaust valve main event deactivation occurs second. Delay between brake activation and main event deactivation may be facilitated using mechanical and/or hydraulic implements as well as electronically.

Systems and methods for operating an engine with deactivating and non-deactivating valves is presented. In one example, the engine may include non-deactivating intake valves, deactivating intake valves, and only non-deactivating exhaust valves. The non-deactivating exhaust valves may operate to open and close during an engine cycle while deactivating intake valves remain closed during the engine cycle to prevent air flow through selected engine cylinders.

A tubular roller valve for an internal combustion engine, which includes a hollow tube having at least one hole, the at least one hole being configured to access an air inlet or an exhaust of a cylinder in an engine block, a tubular outer insulator outside of the hollow tube, the outer insulator being fixed to a cylinder head, and a tubular inner insulator inside of the hollow tube. An additional tube between the hollow tube and the outer insulator can serve to operate as a compression release brake.

An apparatus includes a valve and an actuator. The valve has a portion movably disposed within a valve pocket defined by a cylinder head of an engine. The valve is configured to move relative to the cylinder head a distance between a closed position and an opened position. The portion of the valve defines a flow opening that is in fluid communication with a cylinder of an engine when the valve is in the opened position. The actuator is configured to selectively vary the distance between the closed position and the opened position.

Methods and systems are provided for an engine including cams having different lobe profiles. In one example, cams of a first cam group drive a plurality of deactivatable cylinder valves and cams of a second cam group drive a plurality of non-deactivatable cylinder valves. The cams of the first cam group include a different lobe profile relative to cams of the second cam group.

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.

A dual body rocker arm for controlling a valve of a cylinder of an internal combustion engine includes: a first body; a second body; and a latching arrangement moveable to latch and unlatch the first body and the second body. The latching arrangement includes: a latch pin moveable between a first position in which the latch pin latches the first body and the second body together and a second position in which the first body and the second body are un-latched; and a lever mounted for pivotal motion relative to the first body, a first end of the lever contacting the latch pin, and a second end of the lever configured to contact an actuation arrangement. In use, when the actuation arrangement exerts a force on the second end of the lever, the lever pivots such that the first end of the lever exerts a force on the latch pin.

An actuator arrangement for controlling a latching arrangement of a dual body rocker arm of an internal combustion engine, the dual body rocker arm comprising a first body, a second body, and the latching arrangement, the latching arrangement being controllable to latch and unlatch the first body and the second body. The actuator arrangement includes: an actuation source; a shaft including a cam for controlling the latching arrangement; and a gear mechanism for translating a continuous rotation of the actuation source into an intermittent rotation of the shaft in steps of a predefined degree. In use, a continuous rotation of the actuation source causes, via the gear mechanism, the shaft to rotate in steps of a predefined degree, thereby to change an orientation of the cam relative to the latching arrangement by a predefined amount, so as to control the latching arrangement.

An actuator arrangement for controlling a first latching arrangement of a first dual body rocker arm for controlling an intake valve of an internal combustion engine, and for controlling a second latching arrangement of a second dual body rocker arm for controlling an exhaust valve of the internal combustion engine, the first and second dual body rocker arms each including a first body, a second body, and the latching arrangement controllable to latch and unlatch the first body and the second body. The actuator arrangement includes: an actuation source; and an actuation transmission arrangement for transmitting movement of the actuation source to both the first latching arrangement and the second latching arrangement. In use, movement of the actuation source causes, via the actuation transmission arrangement, control of the first latching arrangement and of the second latching arrangement in common.