초록 ▼

A vehicle on board system for recovering fuel vapors from the fuel tank both during filling of the fuel tank with volatile hydrocarbon liquid fuel and operation of the vehicle engine. A control unit in the fuel tank has a valve assembly actuated by a float to control the flow of fuel vapors from the

A vehicle on board system for recovering fuel vapors from the fuel tank both during filling of the fuel tank with volatile hydrocarbon liquid fuel and operation of the vehicle engine. A control unit in the fuel tank has a valve assembly actuated by a float to control the flow of fuel vapors from the top of the tank into a receiving canister with activated charcoal for absorbing the fuel vapors which can be purged from the canister by operation of the engine. The valve assembly has a valve seat, a flexible elastomeric closure received on a pivotally mounted carrier plate movable to open and closed positions relative to the seat, and a stripper plate encompassing the seat, overlying the closure and pivotally movable by the float to disengage the closure from the seat to open the valve. Preferably, a pad on the stripper plate bears on only a portion of the flexible closure during initial opening of the valve to thereby decrease the force required to initially open the valve and increase the sensitivity and responseness of the valve assembly. Preferably, to substantially prevent any liquid fuel from passing through the valve assembly while it is open, a depending tube encircles the valve assembly and the float is slidably received in the tube with a relatively close fit to prevent fuel sloshing in the tank which enters the tube from being forced past the float and into the open valve assembly. Preferably, the passage for permitting fuel vapors to flow to the open valve assembly communicates with the tank at a position generally vertically below the valve assembly and preferably an intermediate portion of the passage is disposed generally vertically above the valve assembly and preferably above the fuel tank.

대표청구항 ▼

[ What is claimed is:] [19.] A vapor control apparatus for a vehicle fuel tank for containing volatile hydrocarbon liquid fuel which comprises: a housing constructed to be received on a fuel tank adjacent the top of the tank, an outlet passage carried by the housing for communicating with the exteri

[ What is claimed is:] [19.] A vapor control apparatus for a vehicle fuel tank for containing volatile hydrocarbon liquid fuel which comprises: a housing constructed to be received on a fuel tank adjacent the top of the tank, an outlet passage carried by the housing for communicating with the exterior of the tank for supplying fuel vapor from the interior of the tank to the exterior of the tank, a valve assembly carried by the housing adjacent the top of the tank and movable to a closed position and to an open position to communicate with the outlet passage for supplying to the outlet passage fuel vapor from the interior of the tank, a float responsive to the level of liquid fuel in the tank to move the valve assembly to its open position when the level of fuel in the tank is below a first predetermined level and to permit the valve assembly to move to its closed position when the fuel level in the tank is at a second level above the first level, a depending tube carried by the housing and extending around the valve assembly and the float, the float being slidably received in the tube and having a portion in the tube in close proximity with the tube to substantially prevent liquid fuel sloshing in the tank which enters the interior of the tube from passing beyond the float and through the valve assembly when it is in an open position, a check valve disposed adjacent the lower end of the tube to prevent liquid fuel from entering the tube therethrough and to permit fuel to drain from the housing when the fuel level in the tank is lower than the fuel level in the housing even when submerged in liquid fuel, at least one fuel entry opening in the tube spaced above the check valve and through which liquid fuel may enter the tube, and a fuel vapor passage carried by the housing, communicating with the valve assembly to permit the flow of fuel vapor from the interior of the tank to the outlet passage when the valve assembly is open, and having an inlet communicating with the interior of the fuel tank at a position generally vertically above the fuel entry opening and the float, whereby when the housing is received on a vehicle fuel tank in a normal operating position and liquid fuel sloshes in the tank substantially no liquid fuel enters the outlet passage when the valve assembly is open.