Patent ID: 8037865

Claim:
A compression-release brake system for operating at least one exhaust valve of an internal combustion engine during a compression-release engine braking operation, said system comprising: an exhaust rocker arm driven by an exhaust cam member for operating said at least one exhaust valve; a self-contained compression brake control module operatively coupled to said at least one exhaust valve for controlling a lift and a phase angle of said at least one exhaust valve; and said compression brake control module provided to maintain said at least one exhaust valve open during a compression stroke of the engine when said engine performs the compression-release engine braking operation; said compression brake control module including: a casing including a single-piece body defining a piston cavity and an actuator cavity being in fluid communication with each other; a slave piston slidingly mounted within said piston cavity for reciprocating within said piston cavity between an extended position and a collapsed position, said slave piston being provided to engage said at least one exhaust valve in said extended position thereof; a supply conduit formed within said body of said casing adapted to be connected to a source of pressurized hydraulic fluid so as to provide pressurized hydraulic fluid to said piston cavity to extend said slave piston to said extended position thereof when there is a gap between said slave piston and said at least one exhaust valve; a check valve provided between said supply conduit and said piston cavity to hydraulically lock said piston cavity when a pressure of the hydraulic fluid within said piston cavity exceeds the pressure of the hydraulic fluid from said source; and a compression brake actuator disposed in said actuator cavity for controlling said check valve; said compression brake control module is spaced from said exhaust rocker arm so that said exhaust rocker arm is movable relative to said compression brake control module; said single-piece body of said compression brake control module non-movably fixed to one of a cylinder head, a cylinder block of said engine and a dedicated brake rocker arm driven by a dedicated compression-release cam member for operating said at least one exhaust valve during the compression-release engine braking operation.