An evaporative emissions control system configured to recapture and recycle emitted fuel vapor on a vehicle fuel tank is provided. The control system includes a first and second vent tube disposed in the fuel tank, a first and second vent valve, a vent shut-off assembly, a purge canister and a control module. The vent shut-off assembly selectively opens and closes the first and second valves to provide overpressure and vacuum relief for the fuel tank. The control module regulates operation of the vent shut-off assembly based on operating conditions to vent the first and second vent valves to the purge canister. The vehicle fuel tank comprises a saddle tank having first and second lobes and a raised portion arranged generally at a top portion of the fuel tank. The first vent valve is arranged generally in the first lobe and the second vent valve is arranged in the raised portion.

A valve assembly for a fuel tank system including a fuel tank having a fuel tank outlet and a purge canister includes a main valve and a safety check valve. The main valve can be configured to move from a closed position to an open position. The main valve can have a main valve first port fluidly coupled to the outlet of the fuel tank and a main valve second port fluidly connected to the purge canister. The safety check valve can be configured to move from an open position to a closed position upon a pressure drop at the fuel tank outlet exceeding a predetermined threshold. The safety check valve can have a safety check valve first port fluidly coupled to the outlet of the fuel tank and a safety check valve second port fluidly coupled to the purge canister.

A vent shut-off assembly configured to manage vapor recirculation venting during a refueling event on a fuel tank configured to deliver fuel to an internal combustion engine includes a main housing and an actuator assembly. The main housing selectively vents to a carbon canister. The actuator assembly is at least partially housed in the main housing. The actuator assembly comprises a cam assembly having a cam shaft that includes a first cam and a second cam. The first cam has a profile that actuates a first valve that selectively opens a first port fluidly connected to a first vent in the fuel tank. The second cam has a profile that actuates a second valve that selectively opens a second port fluidly connected to a recirculation line that routes vapor back to a filler neck of the fuel tank.

Methods and systems are provided for refueling a vehicle configured with an onboard refueling vapor recovery (ORVR) system, such that a loading of a fuel vapor canister configured to capture and store fuel vapors, is reduced. In one example, during the refueling, a rate at which fuel vapors are routed to the fuel vapor canister is adjusted responsive to an indication that the vehicle is refueling at a gas station equipped with offboard fuel vapor recovery infrastructure. In this way, loading of the fuel vapor canister may be reduced which may prevent undesired bleedthrough emissions resulting from a canister loaded with fuel vapors, particularly in examples where the vehicle is a hybrid vehicle and where engine runtime is limited, thus limiting potential opportunities for purging of the fuel vapor canister.

Methods and systems are provided for providing improving customer satisfaction during a vehicle fuel tank refueling event. A fuel system is configured with a three-way isolation valve and a four port canister. Fuel tank depressurization is expedited by directing fuel tank vapors to a dedicated depressurization port of the canister.

This disclosure is directed to vehicle fuel systems capable of isolating the energy within a fuel tank from the vehicle user. An exemplary fuel system may include a first valve located within a fuel inlet conduit and a second valve located within a vapor recovery recirculation line of the fuel system. The first and second valves may be controlled based on the pressure inside a fuel tank of the fuel system. Fuel may only be transferred into the fuel tank when the fuel tank is within a predefined threshold pressure range. A depressurization sequence of the fuel tank may be automatically initiated when a fuel door of the fuel system is moved to an open position. The positioning of the fuel door may be monitored by a fuel door position monitoring device.

A fuel tank system constructed in accordance to one example of the present disclosure includes a fuel tank and an evaporative emissions control system. The evaporative emissions control system is configured to recapture and recycle emitted fuel vapor. The evaporative emissions control system includes a liquid trap, a first device, a second device, a control module and a G-sensor. The first device is configured to selectively open and close a first vent. The second device is configured to selectively open and close a second vent. The control module regulates operation of the first and second devices to provide over-pressure and vacuum relief for the fuel tank. The G-sensor provides a signal to the control module based on a measured acceleration.

A tank system of a motor vehicle includes a volume-modifying element, which is provided in the interior of the fuel tank at least substantially above the liquid level and which is designed as a deformable bag, which forms a compensation volume connected to the environment, and includes a valve assembly, which closes under the control of a float during the filling of the fuel tank and thus brings about a maximum fill level in the fuel tank. A measure is provided for eliminating an effect of the volume-modifying element on the maximum fill level height. This measure can be that the volume-modifying element is arranged in the fuel tank such that, when the vehicle is standing on a horizontal surface, the top side of the volume-modifying element is not significantly above the fuel fill level at which the valve assembly closes in the vertical axis direction. Other measures include, for example, a controllable valve, which is provided in the connection between the compensation volume of the volume-modifying element and the environment and which is actuated in the closing direction when the fill level rising during the filling process has reached the maximum fill level height.

A fuel tank includes a tank main body configured to reserve a quantity of fuel therein and an oil feed tube fitted to the tank main body to form a fuel feed port. The fuel feed tube has a tip end configured to protrude inwardly of the tank main body, and the tip end is positioned below the upper limit level of the fuel. At a location of the fuel feed tube above the upper limit level, a vent hole is formed to communicate between the interior of the tank main body and the interior of the oil feed tube.

A first casing has an internal cylindrical region defined as a floating/sinking guiding region for a float valve. The wall that forms the cylindrical region includes ventilation windows. A second casing surrounds the first casing to form, about the periphery of the first casing, a ventilation passage that guides fuel vapor in a fuel tank to the ventilation windows through a region that surrounds the first casing. In addition, the second casing surrounds the first casing from a first connection hole side to form, about the periphery of the first casing, a first ventilation passage that guides the fuel vapor in the fuel tank to the ventilation windows through the region that surrounds the first casing, and a second ventilation passage that has a larger passage cross-sectional area than the first ventilation passage. These ventilation passages stabilize floating/sinking operation of the float.