ENGINE SYSTEM AND OPERATION METHOD USING ENGINE BRAKING MECHANISMS FOR EARLY EXHAUST VALVE OPENING

摘要

A valve actuation system for an internal combustion engine is disclosed. The engine has a first set of cylinders having a first set of exhaust valves and a second set of cylinders having a second set of exhaust valves. The valve actuation system for the exhaust valves includes one or more first cams having a compression-release lobe and a main exhaust lobe adapted to transfer valve actuation motion to the first set of exhaust valves, and one or more second cams having an early exhaust valve opening (EEVO) lobe and a main exhaust lobe adapted to transfer valve actuation motion to the second set of exhaust valves. The valve actuation system may provide any combination of (i) main exhaust valve actuation with or without compression release actuation with (ii) main exhaust valve actuation with or without EEVO for the two sets of cylinders.

主权项

1. In an internal combustion engine having at least two cylinders and at least one exhaust valve providing selective communication between each cylinder and an exhaust manifold, a method of operating the engine and actuating the exhaust valves in each cylinder comprising the steps of:
providing one or more first cams having a compression-release lobe and a main exhaust lobe adapted to transfer valve actuation motion to a first exhaust valve associated with a first cylinder; providing one or more second cams having an early exhaust valve opening lobe and a main exhaust lobe adapted to transfer valve actuation motion to a second exhaust valve associated with a second cylinder; and operating the engine in a first positive power mode of operation in which the first exhaust valve in the first cylinder is actuated for a main exhaust event without being actuated for a compression-release event, and the second exhaust valve in the second cylinder is actuated for a main exhaust event without being actuated for an early exhaust valve opening event.