Renault Trucks

Volvo Trucks Ab

Volvo Lastvagnar Ab

Benjamin Girard

Romain Le Forestier

A valve actuation mechanism for an internal combustion engine includes rockers moved by a camshaft, each rocker being adapted to exert a valve opening force on at least a portion of a valve opening actuator of each cylinder, via an activation piston, housed in a bore of the rocker and movable with respect to the rocker under action of a fluid pressure raise in a chamber fluidly connected to the bore, from a first position to a second position with respect to the rocker, in which a cam follower of the rocker is adapted to read at least one auxiliary valve lift sector of a cam of the camshaft so as to perform an engine operating function. Each rocker includes a check valve adapted to control the fluid pressure raise in the chamber. The valve actuation mechanism includes, for each rocker, a stopper fast with a housing of the engine and adapted to exert, on a member of the rocker, a force for opening a valve independent from the check valve, adapted to release fluid from the chamber when the piston has to be moved from its second position to its first position.

Valve actuation mechanism and automotive vehicle comprising such a valve actuation mechanism

A valve actuation mechanism for an internal combustion engine includes rockers moved by a camshaft, each rocker being adapted to exert a valve opening force on at least a portion of a valve actuation mechanism of each cylinder belonging to a housing of the engine, via an engine brake activation piston, housed in a bore of the rocker, and movable with respect to the rocker under action of a fluid pressure raise in a chamber fluidly linked to the bore, from a first position, in which an engine brake function is deactivated, to a second position, in which a roller of the rocker reads at least one engine brake bump of a cam of the camshaft so as to perform the engine brake function. Each rocker includes a discharge valve movable in translation with respect to the rocker, adapted to reduce fluid pressure in the chamber. The engine brake system includes, for each rocker, a stopper fast with the housing and adapted to exert, on a portion of the piston, a force for opening the discharge valve when the activation piston has to be moved from its second position to its first position.

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Saint Laurent de Mure, France

Benjamin Girard