Switching tappet or a roller finger follower for compression release braking

A system, comprising:

• an internal combustion engine including a plurality of cylinders that receive a charge flow from an intake system so as to combust a fuel provided to at least a portion of the plurality of cylinders;
• at least one sensor operable to provide one or more signals indicating operating conditions of the system;
• a valve actuation mechanism configured to control an opening and closing timing of exhaust valves associated with the plurality of cylinders, the valve actuation mechanism including a plurality of switching tappets respectively associated with an exhaust valve of each cylinder, each switching tappet including an inner member in contact with a first cam lobe configured to open the exhaust valve during an exhaust stroke of an associated cylinder of the plurality of cylinders, and an outer member in contact with a second cam lobe configured to open the exhaust valve during a compression stroke of the associated cylinder;
• and
• a controller connected to the at least one sensor and operable to interpret the one or more signals,
• wherein, in response to an engine braking request based on the one or more signals, the controller is configured to control the valve actuation mechanism so as to lock the inner member with the outer member.

A method, comprising:

• receiving a charge flow into a plurality of cylinders of an internal combustion engine system from an intake system, the internal combustion engine system including a valve actuation mechanism, wherein the valve actuation mechanism includes a plurality of switching tappets respectively associated with the plurality of cylinders, each switching tappet comprising an outer member and an inner member selectively locked to each other so as to control an opening and closing timing of an exhaust valve of an associated cylinder of the plurality of cylinders;
• receiving at least one signal from at least one sensor operably connected to a controller of the internal combustion engine system, the at least one signal indicating operating conditions of the internal combustion engine system;
• actuating each switching tappet with a compression release profile in response to a compression release condition associated with the internal combustion engine system such that the outer member is locked to the inner member so as to open the exhaust valve during a compression stroke of the associated cylinder when a first cam lobe of a cam shaft acts on the inner member and a second cam lobe of the cam shaft acts on the outer member;
• and
• locking a cam phaser operably connected to the internal combustion engine system so as to provide compression release event.