Valve unit for an internal combustion engine intake duct, comprising non-return flap valves

Claim 1

A valve unit for an intake duct feeding an internal combustion engine cylinder, said valve unit comprising a plurality of longitudinal channels assembled into superposed modules, each channel having a substantially arcuate base wall and an elastically flexible flap for the purpose of opening and closing a respective channel whereby said valve unit consists of non-return valve means in series with an intake valve of the internal combustion engine, each channel having an inlet section and an outlet section, the inlet section comprising a ledge and a support surface which are clamped with a fixing tab when the modules are formed, each fixing tab being provided on one of said flaps, each base wall having an increasing thickness extending towards the outlet section of the respective channel, each base wall having an inner face and an outer face, the inner and outer faces each having a bending radius, the inner face having a different bending radius than the bending radius of the outer face thereby providing a gradual slight reduction of the respective chamber towards the outlet section of the respective chamber, each base wall being provided with a slot, each slot housing a tight sealing gasket material, and each slot extending through a portion of the base wall.