초록 ▼

An engine valve actuation system is disclosed, which is capable providing compression release engine braking in combination with exhaust gas recirculation while maintaining main exhaust and main intake valve events of constant magnitude during both positive power and engine braking. The system is al

An engine valve actuation system is disclosed, which is capable providing compression release engine braking in combination with exhaust gas recirculation while maintaining main exhaust and main intake valve events of constant magnitude during both positive power and engine braking. The system is also capable of providing a constant level of desired overlap between main exhaust and main intake valve events during both positive power and engine braking. The system may provide the foregoing functions by using first and second valve actuation subsystems to provide the full spectrum of exhaust valve motions. Both the first and second subsystems may receive an input motion from a valve train element. The first subsystem operates only when the engine braking system is enabled. The second subsystem operates both during positive power and during engine braking. When engine braking is enabled, the first and second subsystems work together to provide main exhaust, compression release and exhaust gas recirculation events. When the engine is in positive power mode, the second subsystem works alone, and is limited to providing main exhaust events. Methods of engine valve actuation are also disclosed.

대표청구항 ▼

[ We claim:] [9.] A system for providing main exhaust and compression release valve events to an engine valve element in an internal combustion engine, comprising:means for providing a valve train motion including a main exhaust and a compression release event;first means for (a) providing a compres

[ We claim:] [9.] A system for providing main exhaust and compression release valve events to an engine valve element in an internal combustion engine, comprising:means for providing a valve train motion including a main exhaust and a compression release event;first means for (a) providing a compression release valve event and, (b) providing an initial portion of a main exhaust event, responsive to the valve train motion means, said first means being operatively connected to the means for providing a valve train motion and the engine valve element; andsecond means for (a) providing a latter portion of the main exhaust event and (b), absorbing compression release motion, responsive to the valve train motion means, said second means being operatively connected to the means for providing a valve train motion and the engine valve element,wherein said first means comprises:an outer piston sleeve having an end wall and a side wall, said outer piston sleeve being adapted to be biased into a bore and adapted to be slidable within the bore;a first passage through the end wall of the outer piston sleeve and a second passage through the side wall of the outer piston sleeve, said second passage being adapted to communicate with an opening in the bore as a result of sliding displacement of the outer piston sleeve in a direction opposite to that of the direction in which the outer piston sleeve is adapted to be biased;means for selectively admitting fluid through said first passage into an interior portion of the outer piston sleeve; andan inner piston biased into and slidably disposed in the interior portion of the outer piston sleeve.