Electro-mechanical latching rocker arm engine brake

Abstract

A compression release engine brake assembly adapted for use with an internal combustion engine, and an exhaust valve ( ) operable to open in a normal exhaust lift event (FIG. ) and in a brake lift event (FIG. ). The engine includes an exhaust valve actuating mechanism ( ) for imparting reciprocal movement to said exhaust valve ( ) in response to rotation of a cam shaft ( ) including a cam profile ( ), a normal lift portion ( ) and a brake lift portion ( ). The assembly includes a lost motion device ( ) moveable between a normal lost motion condition (FIG. ) and an actuated condition (FIG. ) in response to movement of an input member ( ). An energy storage spring ( ) is operable, after being compressed to an energy storage condition (FIG. ) to be able to bias the input member ( ) toward a second position, effecting the actuated condition of the lost motion device ( ). A latching mechanism ( ) is operable to first displace the energy storage spring ( ) to a compressed condition, and then release it just before the cam follower ( ) traverses the brake lift portion ( ), in response to the pivotal movement of the rocker arm assembly ( ) which comprises part of the exhaust valve actuating mechanism.