Patent ID: 7316227

Claim:
A positive crankcase ventilation PCV valve for use with a vehicle engine having a throttle valve movable between an idle position and a wide-open position, the PCV valve comprising a wall providing a flow-metering orifice and a first flow-metering surface bordering the orifice, a shell including a valve housing formed to include an interior region containing the wall, the valve housing including an inlet arranged to open into an inlet chamber provided in the interior region and adapted to be coupled to a crankcase of a vehicle and an outlet arranged to open into an outlet chamber provided in the interior region and adapted to be coupled to an intake manifold of the vehicle, the wall being arranged to lie in the interior region of the valve housing to cause the flow-metering orifice formed in the wall to interconnect the inlet and outlet chambers in fluid communication, a flow restrictor extending into the flow-metering orifice to define a variable flow-metering channel therebetween, the flow restrictor being mounted for movement in the flow-metering orifice to vary an effective size of the variable flow-metering channel between a low-vacuum position located to establish a first effective size of the variable flow-metering channel and supported on a platform included in the shell to extend through the flow-metering orifice in response to exposure of the flow restrictor to a low-level vacuum extant in the outlet chamber when the throttle valve has been moved to the wide-open position and a high-vacuum position located away from and unsupported by the platform to extend through the flow-metering orifice to establish a different second effective size of the variable flow-metering channel in response to exposure of the flow restrictor to a high-level vacuum extant in the outlet chamber that is greater than the low-level vacuum when the throttle valve has been moved to the idle position, and flow restrictor locator means for positioning the flow restrictor in a predetermined position in the flow-metering orifice for a selected temperature and pressure in the interior region of the valve housing to move the flow restrictor to the low-vacuum position in response to development of the low-level vacuum in the outlet chamber and to the high-vacuum position in response to development of the high-level vacuum in the outlet chamber so as to establish a predetermined flow rate of metered fumes discharged from the interior region of the valve housing through the outlet in response to development of the selected temperature and pressure in the interior region of the valve housing.