Compression-release engine brake system for lost motion rocker arm assembly and method of operation thereof

摘要

A compression-release brake system for effectuating a compression-release engine braking operation in connection with an internal combustion engine. The system includes a lost motion exhaust rocker assembly including a rocker arm, an actuation piston slidably received by the rocker arm to define part of a piston cavity in the rocker arm and movable between a piston retracted position and a piston extended position, the actuation piston configured to operatively associate with the exhaust valve to permit unseating of the exhaust valve from the seated state, and a reset device received by the rocker arm and operatively associated with the actuation piston to return the exhaust valve to the seated state by the end of the expansion stroke in the brake-on mode.

主权项

1. A compression-release brake system for effectuating a compression-release engine braking operation in connection with an internal combustion engine comprising an engine cylinder that is associated with a four-stroke piston cycle comprising a compression stroke and an expansion stroke and is provided with at least one intake valve, at least one exhaust valve, and at least one exhaust valve return spring exerting a closing force on the exhaust valve to urge the exhaust valve into a seated state, the compression-release brake system comprising:
a lost motion exhaust rocker assembly comprising a rocker arm; an actuation piston slidably received by the rocker arm to define part of a piston cavity in the rocker arm and movable between a piston retracted position and a piston extended position, the actuation piston being configured to be operatively associated with the exhaust valve to permit unseating of the exhaust valve from the seated state; and a reset device received by the rocker arm and comprising
a reset check valve movable between an open position in which a communication port is open to place the piston cavity in fluid communication with a supply conduit through the communication port and a closed position in which the communication port between the piston cavity and the supply conduit is closed;a reset pressure spring operatively associated with the reset check valve to permit application of a biasing force to the reset check valve to urge the reset check valve towards the open position; anda trigger operatively connected to the reset check valve and the reset pressure spring and movable between a trigger retracted position and a trigger extended position.