PCV system with a check valve device

Claim 1

A positive crankcase ventilation system with a check valve device comprising: a PCV line connecting a cylinder head cover to an intake passage of an internal combustion engine; a PCV valve disposed in the PCV line; a trap chamber disposed in the PCV line downstream of the PCV valve for trapping oil mist, the trap chamber having a bottom wall on which oil trapped in the trap chamber collects; and a check valve device provided at the bottom wall of the trap chamber so as to be substantially vertically oriented, the check valve device including: a valve body having a vertically extending valve stem and a valve head extending radially outward from a lower end portion of the valve stem, the valve head being constructed of elastomer; a seat member including a valve seat surface at a lower surface of the seat member, center hole means containing the valve stem of the valve body, and at least one perforation penetrating the seat member to open in the lower surface of the seat member in a region between the center hole means and the radially outward extent of the valve head, the valve head of the valve body being disposed below the seat member so as to resiliently contact the valve seat surface; and an annular rigid stopper plate loosely disposed opposite the region of the perforations between the lower surface of the seat member and the valve head of the valve body.