PRESSURE SENSING DEVICE

FIELD

[0001] The present disclosure relates generally to fuel tanks on passenger vehicles and more particularly to a fuel tank isolation valve having a transverse connection architecture and an integrated or separable pressure sensing device.

BACKGROUND

[0002] 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 electric hybrid and 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.

[0003] High-pressure fuel tanks may use an isolation valve to open and close a vapor path between the fuel tank and a vapor recovery canister. For high-pressure fuel tank systems an isolation valve may be used to isolate fuel tank emissions and prevent them from overloading the canister and vapor lines. The isolation valve itself may be a normally closed valve that is opened to allow vapor flow for tank depressurization or any other event where vapor release is desired. While existing isolation valves work for their intended purpose, a need exists to further the art.

[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 isolation valve assembly configured to selectively vent fuel vapor from a fuel tank to a vapor recovery canister includes a housing having an inlet and an outlet. The valve assembly is fluidly coupled between the fuel tank and the vapor recovery canister. The inlet is fluidly coupled to a vapor space of the fuel tank. The outlet is fluidly coupled to the vapor recovery canister. The inlet and outlet are arranged on the housing at a transverse relationship.

[0006] According to additional features, the housing generally defines an inlet cavity, a flow restrictor cavity, an over-pressure relief (OPR) cavity and an outlet cavity. The inlet defines the inlet cavity. The outlet defines the outlet cavity. The inlet cavity defines an inlet axis. The OPR cavity defines an OPR axis. The inlet axis and the OPR axis are parallel. The inlet axis and the OPR axis are offset. A passage defined between the flow restrictor cavity and the OPR cavity defines a passage axis that is parallel to the OPR axis.

[0007] According to still other features, the fuel tank isolation valve assembly further comprises a pressure sensor that senses a pressure in the vapor space of the fuel tank. In one configuration, the pressure sensor is integrally formed into the housing of the valve housing. In another configuration, the pressure sensor is coupled to the housing of the valve assembly. The pressure sensor can be coupled to the housing at the OPR cavity.

[0008] A fuel tank isolation valve assembly constructed in accordance to additional features includes a housing, a solenoid assembly and an over-pressure relief (OPR) valve. The fuel tank isolation valve assembly is configured to selectively or passively vent fuel vapor from a fuel tank to a vapor recovery canister or from the vapor recovery canister to the fuel tank. The housing has an inlet and an outlet. The valve assembly is fluidly coupled between the fuel tank and the vapor recovery canister. The inlet is fluidly coupled to a vapor space of the fuel tank. The outlet is fluidly coupled to the vapor recovery canister. The inlet and outlet are arranged on the housing at a transverse relationship. The solenoid assembly is disposed in the housing and is configured to selectively lift a seal in a flow restrictor cavity off a valve seat allowing vapor to pass from the inlet to the outlet. The OPR valve is disposed in an OPR cavity in the housing and is configured to facilitate opening a fuel vapor flow path from the fuel tank to the vapor recovery canister upon translation of an OPR seal along a translation axis. The inlet defines an inlet cavity that defines an inlet axis. The translation axis is parallel to the inlet axis.

[0009] According to additional features, the outlet defines an outlet cavity that defines an outlet axis. The inlet and outlet axes are transverse. A passage defined between the flow restrictor cavity and the OPR cavity defines a passage axis that is parallel to the translation axis. The fuel tank isolation valve assembly can further comprise a pressure sensor. The pressure sensor can be configured to sense pressure in the vapor space of the fuel tank. The pressure sensor is coupled to the housing at the OPR cavity.

[0010] A fuel tank system configured according to one example of the present disclosure includes a fuel tank, a vapor recovery canister and a valve assembly. The fuel tank has a vapor space. The valve assembly has a housing. The valve assembly is fluidly coupled between the fuel tank and the vapor recovery canister and is arranged to selectively control fuel vapor flow between the fuel tank and the vapor recovery canister. The housing of the valve assembly includes an inlet fluidly coupled to the vapor space, a valve disposed therein, and an outlet fluidly coupled to the vapor recovery canister. The inlet and outlet are transverse relative to each other.

[0011] According to other features, the fuel tank system further comprises a pressure sensor that senses a pressure in the vapor space of the fuel tank. A controller receives a signal from the pressure sensor and communicates a signal to the valve assembly to open and allow vapor to pass to the vapor recovery canister. The pressure sensor can be integrally formed into the housing of the valve assembly or coupled to the housing of the valve assembly. The valve assembly can further include a solenoid assembly arranged within the housing. The solenoid assembly comprises an armature, a solenoid spring and a coil. The solenoid spring can be configured to generate a force sufficient to urge the armature out of the solenoid assembly when the solenoid assembly 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. 2 is a first perspective view of the valve assembly of FIG. 1 ;

[0015] FIG. 3 is a second perspective view of the valve assembly of FIG. 2;

[0016] FIG. 4 is a top view of the valve assembly of FIG. 2;

[0017] FIG. 5 is a side view of the valve assembly of FIG. 2;

[0018] FIG. 6 is a rear view of the valve assembly of FIG. 2;

[0019] FIG. 7 is a first cross-sectional view of the valve assembly taken along lines 7-7 of FIG. 2 and shown with portions of the solenoid assembly removed;

[0020] FIG. 8 is another cross-sectional view of the valve assembly of FIG. 2 and shown without the pressure sensor and shown with portions of the solenoid assembly removed;

[0021] FIG. 9 is a valve assembly constructed according to one prior art example; and

[0022] FIG. 10 is a cross-sectional view of the housing of the valve assembly of FIG. 1 .

DETAILED DESCRIPTION

[0023] 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 vapor recovery 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.

[0024] The evaporative emissions control system 20 includes a fuel tank isolation valve assembly 30. As will be described more fully herein, the valve assembly 30 includes a housing valve body 32 having connection architecture (inlet and outlet) oriented at a transverse relationship. As used herein,“transverse” is used to denote an angle between eighty-five and ninety-five degrees and preferably ninety degrees. Furthermore, the valve assembly 30 includes a pressure sensing device 34. The pressure sensing device can be a sensor that is integrated with the housing 32 or separable. Additional description of a valve assembly, without the ninety degree orientation and pressure sensing device 34, may be found in commonly owned U.S. Patent No. 8,944,100 and 9,500,291 , the contents of which are expressly incorporated herein by reference.

[0025] In general, the valve assembly 30 may control fuel vapor flow between the fuel tank 12 and the vapor recovery canister 22. While the valve assembly 30 is shown located between the fuel tank 12 and the vapor recovery canister 22, the valve assembly 30 may be configured elsewhere such as between the vapor recovery 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 some cases based on a signal from the pressure sensor 34), in order to provide over-pressure and vacuum relief for the fuel tank 12. The pressure sensor 34 can communicate a pressure signal to the controller 14. The valve assembly 30 can be configured to control a flow of fuel vapor between the fuel tank 12 and the vapor recovery canister 22. The valve assembly 30 includes the 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 vapor recovery canister 22 via a second connector (not specifically shown). In general, the housing 32 has an inlet 24 that receives fuel vapor from the fuel tank 12 and an outlet 26 that releases fuel vapor to the vapor recovery canister 22. In one configuration a vent line is coupled between the inlet 24 and a vapor space 36 in the fuel tank 12.

[0026] As shown in the FIGS, the inlet port 24 and the outlet port 26 of the housing 32 are oriented at a transverse relationship. In the example shown, the inlet port 24 and the outlet port 26 are oriented at ninety degrees relative to each other. As specifically shown in FIG. 5, an angle 38 is defined between an axis 24A along the inlet 24 and an axis 26A along the outlet 26. The ninety degrees relationship provides improved packaging benefits in the fuel tank 12. Moreover, molding of the housing valve body 32 is simpler and more repeatable as compared to prior art valve assembly designs that have the inlet and outlets arranged at parallel or substantially one hundred eighty degrees relative to each other. Explained further, prior art designs that have 180 degree (or parallel) orientations require cores during manufacturing that intersect to form the internal cavities of the valve housing. As such, the injection molding process can be difficult is such prior art designs. The transverse relationship between the inlet and outlets 24 and 26 of the valve assembly 30 in the present disclosure overcomes prior art challenges and minimizes unfavorable situations such as, but not limited to, die lock that may occur during injection molding.

[0027] In other advantages, the pressure sensor 34 can more easily be coupled to or integrated into the housing valve body 32 without having to further modify the housing 32. The pressure sensor 34 can monitor the pressure in the tank 12 before the vapor exits to the vapor recovery canister 22. In most implementations, the valve assembly 30 can be used in a pressurized fuel system such as a hybrid vehicle fuel system. When the vehicle is operating in an electric mode, the fuel tank 12 becomes a closed (unvented) system. Fuel can be volatile from extreme temperatures and/or sloshing within the fuel tank 12 creating undesirable elevated pressure within the fuel tank 12. Such pressure can act on a compliant seal 44 (FIG. 7). By incorporating the pressure sensor 34, the controller 14 can react (purge/vent) when the pressure sensor 34 sends a signal to the controller 14 indicative of a pressure within the fuel tank 12 that exceeds a predetermined threshold. In other methods, the controller 14 can pulse (series of open and closing events) the valve assembly 30 during vehicle operation to relieve the pressure (over vacuum release, OVR) within the fuel tank 12.

[0028] The housing 32 accommodates the over-pressure relief (OPR) valve 40. The OPR valve 40 includes a piston 42 (FIG. 8), which may be formed from a suitable chemically resistant material such as an appropriate plastic or aluminum. The OPR valve 40 can also include the compliant seal 44, which may be formed from a suitable chemically resistant elastomeric material.

[0029] The piston 42 and the seal 44 may be combined into a unitary piston assembly via an appropriate manufacturing process such as over-molding. The piston 42 and the seal 44 are urged to close a passage 48 (FIG. 7) by a spring 50. In some configurations, the spring 50 can be rated to compress upon a threshold pressure being reached allowing the seal 44 to translate (along a translation axis 444A, FIG. 10) and mechanically open to relieve pressure in the fuel tank 12. 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 vapor recovery 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.

[0030] 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. The armature 62 can be coupled to a poppet 68. When the armature 62 translates upwardly, a compliant seal 74 is lifted off a valve seat 76 allowing vapor to pass therethrough. The solenoid assembly 60 is exemplary and may be configured differently within the scope of this disclosure.

[0031] 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 the compliant seal 74, which may be formed from a suitable chemically resistant rubber. The flow restrictor 70 is configured to be normally closed.

[0032] Turning now to FIGS. 9 and 10, additional advantages of the housing valve body 32 of the instant disclosure will be described. FIG. 9 illustrates a fuel tank isolation valve assembly 330 according to one prior art example. The fuel tank isolation valve assembly 330 includes a housing 332 that defines an inlet 324 and an outlet 326 that are generally parallel or arranged at a 180 degree relationship. The housing 332 generally defines an inlet cavity 340, a flow restrictor cavity 342, an OPR cavity 344 and an outlet cavity 346. In some instances it can be difficult to manufacture the housing 332 having such cavities arranged in these relative positions.

[0033] Various hydraulic cores can be located for defining the various cavities during an injection molding process. In this regard, once the various cores are positioned, plastic can be injected between a tool or mold and the cores for ultimately forming the housing 332. For example, in some instances, a single hydraulic core must be positioned at a location generally through the inlet cavity 340, through a location that would become the flow restrictor cavity 342 and ultimately into an area that would become the OPR cavity 344. In this example, such a hydraulic core is necessary to ensure that the flow of plastic could be effectively delivered to the area that would become the OPR cavity 344 of the housing 332. In other words, the OPR cavity 344 is die locked and challenging to effectively deliver flowable plastic during molding. As can be appreciated, advancing (and retracting) a core through a passage 350 between the flow restrictor cavity 342 and the OPR cavity 344 can be difficult. Another challenging intersection is at passage 352 that connects the OPR cavity 344 and the outlet cavity 346. In some examples, the core used to define the outlet cavity 346 can slidably negotiate along another core within the passage 352. Such metal on metal contact is generally undesirable.

[0034] With reference to FIG. 10, the housing valve body 32 generally defines an inlet cavity 440, a flow restrictor cavity 442, an over-pressure relief OPR cavity 444 and an outlet cavity 446. The inlet cavity 440 defines an inlet axis 440A. The flow restrictor cavity 442 defines a flow restrictor cavity 442A. The OPR cavity 444 defines an OPR axis 444A. The outlet cavity 446 defines an outlet axis 446A. The inlet and outlet axes 440A and 446A are transverse. The inlet axis 440A and the OPR axis 444A are parallel.

[0035] In contrast to the prior art housing 332 in FIG. 9, the OPR cavity 444 can be approached during a manufacturing process with a hydraulic core from the right side (as viewed from FIG. 10) without needing to initially pass through the flow restrictor cavity 442. In this regard, the manufacturing of the housing valve body 32 having the transverse inlet and outlets 24, 26 is more robust and repeatable while being less difficult than that of the housing 332 described above with respect to FIG. 9. Explained in further detail, a separate core that is advanced into each of the areas that would become the inlet cavity 440, flow restrictor cavity 442, the OPR cavity 444 and the outlet cavity 446 can each move independently into and out of position without worry of interfering or negotiating any other cavity. In some examples, one or more cores can remain stationary. Moreover, passage 460 can be formed with the core associated with the OPR cavity 444 (instead of the core associated with the flow restrictor cavity 342 and OPR cavity 344 on the housing 332 above). The passage 460 defines a passage axis 460A. The passage axis 460A is parallel to the OPR axis 444A. The inlet axis 440A and the OPR axis 444A are parallel and offset. Additionally, cores do not slide against each other avoiding any metal to metal contact.

[0036] 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.