Volumetric control valve unit for crankcase ventilation system

An internal combustion engine having a crankcase and an intake manifold, a filter unit defining a condensation filtration chamber and having an upper outlet opening, inlet conduit means accommodating the flow of vapors from the crankcase to the condensation filtration chamber, and outlet conduit means accommodating the flow of vapors from the outlet opening to the intake manifold:

• a volumetric control valve unit within the condensation filtration chamber for metering the flow of vapors between the condensation filtration chamber and the outlet opening comprising a vertical tubular member mounted at its upper end in the outlet opening, said tubular member being formed with slot means adjacent the upper end thereof to provide first passageway means restricting the flow of vapors through said control valve unit and presenting a metering area corresponding to a predetermined value of pressure desired in the crankcase under normal operating conditions, valve seat means adjacent the lower end of said tubular member, a ball valve within said tubular member and normally seated on said valve seat means, and said ball valve being unseated from said valve seat means when the pressure in the crankcase exceeds said predetermined value of pressure to provide additional passageway means for the flow of vapors through said control valve unit.