CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Patent Application No. 61/984,447 filed on April 25, 2014. The disclosure of the above application is incorporated herein by reference.

FIELD

[0002] The present disclosure relates generally to fuel tanks on passenger vehicles and more particularly to a fuel tank isolation valve having a shut-off feature.

BACKGROUND

[0003] Fuel vapor emission control systems are becoming increasingly more complex, in large part in order to comply with environmental and safety regulations imposed on manufacturers of gasoline powered vehicles. Along with the ensuing overall system complexity, complexity of individual components within the system has also increased. Certain regulations affecting the gasoline-powered vehicle industry require that fuel vapor emission from a fuel tank's ventilation system be stored during periods of an engine's operation, in order for the overall vapor emission control system to continue to function for its intended purpose, periodic purging of stored hydrocarbon vapors is necessary during operation of the vehicle.

[0004] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

SUMMARY

[0005] A fuel tank system constructed in accordance to one example of the present disclosure can include a fuel tank, a purge canister, a valve assembly and a shut-off valve. The valve assembly can be fluidly coupled between the fuel tank and the purge canister. The valve assembly can selectively control fuel vapor flow between the fuel tank and the purge canister. The shut-off valve can be fluidly coupled between the fuel tank and the valve assembly. The shut-off valve can be connected between a first fluid line connected to the fuel tank and a second fluid line connected with the valve assembly. The shut-off valve can selectively inhibit fuel vapor from passing from the first fluid line to the second fluid line.

[0006] According to other features, the shut-off valve is normally open. In the open position, fuel vapor is free to pass between the first fluid line and the second fluid line. The shut-off valve can include a movable member that selectively actuates to move a valve seal against a valve seat. When the valve seal is positioned against the valve seat in a closed position, fuel vapor is precluded from passing between the first fluid line and the second fluid line. The movable member can include a manually actuable movable member. The manually actuable movable member can comprise one of a plunger, a screw and a swing arm.

[0007] In other features, the shut-off valve can comprise a valve housing having a floating main valve that is configured to slidably traverse within the valve housing between a closed position and an open position. The floating main valve can move to the closed position upon a pressure differential exceeding a threshold at the fuel tank. In one configuration the shut-off valve further comprises a solenoid disposed on the valve housing and including a pin that actuates through a passage configured on the valve housing to engage the floating main valve. The floating main valve can further define a notch thereon. The pin can selectively engage the notch to maintain the floating main valve in an open position. In one example, the shut-off valve can further comprise a biasing member that biases the floating main valve toward one of an open position and a closed position. The shut-off valve can move to the closed position when the solenoid is not energized.

[0008] A fuel tank system constructed in accordance to additional features of the present disclosure can include a fuel tank, a purge canister, a valve assembly and a shut- off valve. The valve assembly can be fluidly coupled between the fuel tank and the purge canister. The valve assembly can selectively control fuel vapor flow between the fuel tank and the purge canister. The shut-off vaive can be fluidly coupled between the fuel tank and the valve assembly. The shut-off valve can have a movable member that selectively actuates to move a valve seal against a valve seat. When the vaive seal is positioned against the valve seat in a closed position, fuel vapor is precluded from passing into the valve assembly. The shut-off valve can be connected between a first fluid line connected to the fuel tank and a second fluid line connected with the valve assembly. The shut-off valve can selectively inhibit fuel vapor from passing from the first fluid line to the second fluid line.

[0009] According to additional features, the shut-off valve is normally open. In the open position, fuel vapor is free to pass between the first fluid line and the second fluid line. The movable member can further comprise a manually actuable movable member. The manually actuable movable member can comprise one of a plunger, a swing arm and a screw.

[0010] A fuel tank system constructed in accordance to additional features of the present disclosure can include a fuel tank, a purge canister, a valve assembly and a shut- off valve. The valve assembly can be fluidly coupled between the fuel tank and the purge canister. The valve assembly can selectively control fuel vapor flow between the fuel tank and the purge canister. The shut-off valve can be fluidly coupled between the fuel tank and the valve assembly. The shut-off valve can have a floating main valve that is configured to slidably traverse within the valve housing from an open position to a closed position upon a pressure differential exceeding a threshold at the fuel tank. When the floating main valve is in the closed, fuel vapor is precluded from passing into the valve assembly. The shut-off valve can be connected between a first fluid line connected to the fuel tank and a second fluid line connected with the valve assembly. The shut-off valve can selectively inhibit fuel vapor from passing from the first fluid line to the second fluid line.

[0011] According to additional features, the shut-off valve further comprises a solenoid disposed on the valve housing and including a pin that actuates through a passage configured on the valve housing to engage the floating main valve. The floating main valve can further define a notch thereon. The pin can selectively engage the notch to maintain the floating main valve in an open position. In one example, the shut-off valve can further comprise a biasing member that biases the floating main valve toward one of an open position and a closed position. The shut-off valve can move to the closed position when the solenoid is not energized.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0013] FIG. 1 is a schematic illustration of a fuel tank system having an evaporative emissions control system including a valve assembly constructed in accordance to one example of the present disclosure;

[0014] FIG. 2A is a schematic illustration of a fuel tank configuration having a normally open shut-off valve configured upstream of a fuel tank isolation valve according to one example of the present disclosure and shown with the shut-off valve in an open position;

[0015] FIG. 2B is a schematic illustration of the fuel tank configuration of FIG. 2A and shown with the shut-off valve in a closed position; and

[0016] FIG. 3 is schematic illustration of a fuel tank configuration having shut-off valve configured upstream of the fuel tank isolation valve according to another example of the present disclosure.

DETAILED DESCRIPTION

[0017] With initial reference to FIG. 1 , a fuel tank system constructed in accordance to one example of the present disclosure is shown and generally identified at reference number 10. The fuel tank system 10 can generally include a fuel tank 12 configured as a reservoir for holding fuel to be supplied to an internal combustion engine via a fuel delivery system, which includes a fuel pump (not specifically shown). A controller 14 can be configured to regulate the operation of the engine and its fuel delivery system. The fuel tank 12 is operatively connected to an evaporative emissions control system 20 that includes a purge canister 22 adapted to collect fuel vapor emitted by the fuel tank 12 and to subsequently release the fuel vapor to the engine. The controller 14 can also be configured to regulate the operation of evaporative emissions control system 20 in order to recapture and recycle the emitted fuel vapor. [0018] The evaporative emissions control system 20 includes a valve assembly 30. Additional description of the valve assembly 30 may be found in commonly owned U.S. Patent No. 8,944,100, the contents of which are expressly incorporated herein by reference. In general, the valve assembly 30 may control fuel vapor flow between the fuel tank 12 and the purge canister 22. While the valve assembly 30 is shown located between the fuel tank 12 and the purge canister 22, the valve assembly 30 may be configured elsewhere such as between the purge canister 22 and the engine. The controller 14 can be adapted to regulate the operation of a valve assembly 30 to selectively open and close the valve, in order to provide over-pressure and vacuum relief for the fuel tank 12. The valve assembly 30 can be configured to control a flow of fuel vapor between the fuel tank 12 and the purge canister 22. The valve assembly 30 includes a housing 32, which retains all internal components of the valve assembly 30. The housing 32 can connect to the fuel tank 12 via a first connector (not specifically shown) and to the purge canister 22 via a second connector (not specifically shown).

[0019] The housing 32 accommodates an over-pressure relief (OPR) valve 40. The OPR valve 40 includes a piston 42, which may be formed from a suitable chemically resistant material such as an appropriate plastic or aluminum. The OPR valve 40 can also include a compliant seal 44, which may be formed from a suitable chemically resistant elastomeric material.

[0020] The piston 42 and the seal 44 may be combined into a unitary piston assembly via an appropriate manufacturing process such as overmolding. The piston 42 and the seal 44 are urged to close a passage 48 by a spring 50. The OPR valve 40 is configured to facilitate opening a first fuel vapor flow path being traversed by the fuel vapor flowing in a direction from the fuel tank 12 toward the purge canister 18 when the fuel tank 12 is above a first predetermined pressure value. The first predetermined pressure value is preferably a positive number, representing an extreme or over-pressure condition of the fuel tank 12.

[0021] The valve assembly 30 can include a solenoid assembly 60 arranged inside the housing 32. The solenoid assembly 60 is adapted to receive electrical power from a vehicle alternator or from an energy-storage device (not shown), and be triggered or energized by a control signal from the controller 14. The solenoid assembly 60 can include an armature 62, a solenoid spring 64 and a coil 66. The solenoid spring 64 can be configured to generate a force sufficient to urge armature 62 out of the solenoid assembly 60, when the solenoid assembly 60 is not energized. The coil 66 can be configured to energize solenoid assembly 60, and to withdraw the armature 62 into the solenoid assembly 60 by overcoming the biasing force of the solenoid spring 64 and exposing an orifice to allow vapor to flow therethrough.

[0022] The valve assembly 30 can additionally include a flow restrictor 70. The flow restrictor 70 can be arranged inside the housing 32. The flow restrictor 70 includes a piston 72 which may be formed from a suitable chemically resistant material such as an appropriate plastic or aluminum. The flow restrictor 70 also includes a compliant seal 74, which may be formed from a suitable chemically resistant rubber. The flow restrictor 70 is configured to be normally closed.

[0023] With reference now to FIGS. 2A and 2B, a fuel tank configuration constructed in accordance to one example of the present disclosure is shown and identified at reference 100. The fuel tank configuration 100 includes the fuel tank 12, the purge canister 22, the valve assembly 30 and a normally open shut-off valve 110. The normally open shut-off valve 110 is positioned upstream of the valve assembly 30 and downstream of the fuel tank 12. Specifically, the normally open shut-off valve 110 fluidly connects a first fluid line 120 and a second fluid line 122. The first fluid line 120 is fluidly connected between the fuel tank 12 and the normally open shut-off valve 110. The second fluid line 122 is fluidly connected between the normally open shut-off valve 110 and the valve assembly 30. Because the shut-off valve 110 is normally open (FIG. 2A), fluid (vapor) is free to pass from the fuel tank 12, through the first fluid line 120, through the second fluid line 122 and to the valve assembly 30.

[0024] The normally open shut-off valve 110 can include a movable member 130 that can be selectively actuated (FIG. 2B) to move a valve seal 132 against a valve seat 134. When the valve seal 132 is positioned against the valve seat 134, fluid (vapor) is precluded from passing between the first fluid line 120 and the second fluid line 122. The movable member 130 can be a plunger, a swing arm, a threaded screw or any other mechanism that can move the valve seal 132 and valve seat 134 between an unseated position (i.e. normally open) and a seated position (i.e. closed). The normally open shut- off valve 110 of the fuel tank configuration 100 can be manually actuated to the closed position such as during service of the valve assembly 30. in this regard, once the normally open shut-off valve 1 10 is moved to the closed position, the valve assembly 30 can be removed from the second fluid line 122 or otherwise disconnected from the fuel tank configuration 100 to be serviced and/or replaced.

[0025] With reference now to FIG. 3, a fuel tank configuration constructed in accordance to one example of the present disclosure is shown and identified at reference 150. The fuel tank configuration 150 includes the fuel tank 12, the purge canister 22, the valve assembly 30 and a supplemental shut-off valve 160. The supplemental shut-off valve 160 is positioned upstream of the valve assembly 30 and downstream of the fuel tank 12. Specifically, the supplemental shut-off valve 160 fluidly connects a first fluid line 170 and a second fluid line 172. The first fluid line 170 is fluidly connected between the fuel tank 12 and the supplemental shut-off valve 160. The second fluid line 172 is fluidly connected between the supplemental shut-off valve 160 and the valve assembly 30. The supplemental shut-off valve 160 is normally open. In this regard, fluid (vapor) is free to pass from the fuel tank 12, through the first fluid line 170, through the second fluid line 172 and to the valve assembly 30.

[0026] The supplemental shut-off valve 160 can incorporate a valve housing 180 having a floating main valve 182 that is configured to slidably traverse within the valve housing 180 in a direction left and right as viewed in FIG. 3. The geometry of the floating main valve 182 is merely exemplary and other configurations are contemplated. A solenoid 184 can be disposed on the valve housing 180. The solenoid 184 can have a pin 188 that actuates through a passage configured on the valve housing 180 to engage a notch 190 defined on the floating main valve 182 to maintain the floating main valve 182 in an open position. The pin 188 can actuate as a result of energizing coils within the solenoid 184. A biasing member 192 can be disposed in the valve housing 180 and configured to bias the floating main valve 182 in a direction leftward as viewed in FIG. 3.

[0027] The supplemental shut-off valve 160 can be configured to move to a mechanically closed position. When the solenoid 184 is not energized, the supplemental shut-off valve 160 will close when a difference in tank pressure drops beyond a threshold in a short amount of time. For example, should the valve assembly 30 be disconnected from the second fluid line 172, the supplemental shut-off valve 160 will close precluding vapor from passing from the first fluid line 170 to the second fluid line 172. This differential pressure will result in a force acting on the floating valve 182 against the spring force of the spring 192 and urging the floating main valve 182 rightward until the supplemental shut-off valve 160 is closed.

[0028] The foregoing description of the examples has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular example are generally not limited to that particular example, but, where applicable, are interchangeable and can be used in a selected example, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.