CN114502406A - Improved fuel tank isolation valve with integrated stepper motor - Google Patents
Improved fuel tank isolation valve with integrated stepper motor Download PDFInfo
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- CN114502406A CN114502406A CN202080003905.8A CN202080003905A CN114502406A CN 114502406 A CN114502406 A CN 114502406A CN 202080003905 A CN202080003905 A CN 202080003905A CN 114502406 A CN114502406 A CN 114502406A
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- fuel tank
- valve
- isolation valve
- stepper motor
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- 239000002828 fuel tank Substances 0.000 title claims abstract description 65
- 238000002955 isolation Methods 0.000 title claims abstract description 49
- 239000000446 fuel Substances 0.000 claims abstract description 26
- 230000006835 compression Effects 0.000 claims description 34
- 238000007906 compression Methods 0.000 claims description 34
- 238000007789 sealing Methods 0.000 claims description 20
- 239000000126 substance Substances 0.000 claims 1
- YBGRCYCEEDOTDH-JYNQXTMKSA-N evap protocol Chemical compound O=C1C=C[C@]2(C)[C@H]3[C@@H](O)C[C@](C)([C@@](CC4)(O)C(=O)CO)[C@@H]4[C@@H]3CCC2=C1.O([C@H]1C[C@@](O)(CC=2C(O)=C3C(=O)C=4C=CC=C(C=4C(=O)C3=C(O)C=21)OC)C(=O)CO)[C@H]1C[C@H](N)[C@H](O)[C@H](C)O1.COC1=C(O)C(OC)=CC([C@@H]2C3=CC=4OCOC=4C=C3C(O[C@H]3[C@@H]([C@@H](O)[C@@H]4O[C@H](C)OC[C@H]4O3)O)[C@@H]3[C@@H]2C(OC3)=O)=C1.C([C@H](C[C@]1(C(=O)OC)C=2C(=C3C([C@]45[C@H]([C@@]([C@H](OC(C)=O)[C@]6(CC)C=CCN([C@H]56)CC4)(O)C(=O)OC)N3C)=CC=2)OC)C[C@@](C2)(O)CC)N2CCC2=C1NC1=CC=CC=C21 YBGRCYCEEDOTDH-JYNQXTMKSA-N 0.000 abstract description 3
- 239000012530 fluid Substances 0.000 description 7
- 238000004891 communication Methods 0.000 description 5
- 238000013461 design Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 238000013022 venting Methods 0.000 description 1
Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M25/0836—Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K15/00—Arrangement in connection with fuel supply of combustion engines or other fuel consuming energy converters, e.g. fuel cells; Mounting or construction of fuel tanks
- B60K15/03—Fuel tanks
- B60K15/035—Fuel tanks characterised by venting means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K15/00—Arrangement in connection with fuel supply of combustion engines or other fuel consuming energy converters, e.g. fuel cells; Mounting or construction of fuel tanks
- B60K15/03—Fuel tanks
- B60K15/035—Fuel tanks characterised by venting means
- B60K2015/0358—Fuel tanks characterised by venting means the venting is actuated by specific signals or positions of particular parts
- B60K2015/03585—Fuel tanks characterised by venting means the venting is actuated by specific signals or positions of particular parts by gas pressure
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60Y—INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY
- B60Y2200/00—Type of vehicle
- B60Y2200/90—Vehicles comprising electric prime movers
- B60Y2200/92—Hybrid vehicles
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M2025/0845—Electromagnetic valves
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Sustainable Energy (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- General Engineering & Computer Science (AREA)
- Supplying Secondary Fuel Or The Like To Fuel, Air Or Fuel-Air Mixtures (AREA)
- Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)
- Self-Closing Valves And Venting Or Aerating Valves (AREA)
- Electrically Driven Valve-Operating Means (AREA)
Abstract
The present invention relates to an improved Fuel Tank Isolation Valve (FTIV) assembly. The present invention relates to a stepper-motor driven valve having application in an EVAP system and to maintain pressure inside a fuel tank in a protected pressure range, both under overpressure and over-vacuum conditions, along with a controlled flow of fuel vapor from the tank to a canister, when refueling.
Description
Technical Field
The present invention relates to an improved fuel tank isolation valve. More particularly, the present invention relates to an improved fuel tank isolation valve integrated with a stepper motor for plunger movement and embedded functions of over-pressure and over-vacuum relief, which is of compact design with less weight and cost and provides precise controlled flow.
Background
Most of the time, hybrid vehicles are operated by electric power, and the internal combustion engine is idle. Since the fuel tank is a closed system, it leads, in general, to a positive pressure inside the fuel tank due to the evaporation of the stored fuel. Further, it is necessary for the vehicle to maintain an elevated pressure in the fuel tank to suppress the rate of fuel vapor generation and minimize hydrocarbon emissions to the atmosphere. The most obvious solution to overcome the problem is to provide a Fuel Tank Isolation Valve (FTIV) attached to the fuel tank to control fuel tank venting. A Fuel Tank Isolation Valve (FTIV) may be located in a conduit between a fuel tank and a fuel vapor canister in an evaporative emission control system. When the pressure exceeds the protective limit, it opens automatically and the valve is electrically actuated upon refueling.
Fuel Tank Isolation Valves (FTIV) also enable fuel vapor containment in the fuel tank until conditions are not suitable for the engine to handle excess vapor. Typically, the tank isolation valve includes an electrically controlled solenoid valve to open and close the inlet and outlet ports with less precise control or no control over the opening at the intermediate position. Thus, there is no precise control of the flow of fuel vapor from the fuel tank to the canister during refueling.
In US20020112702a1, a method for operating a fuel tank isolation valve and a canister vent valve is disclosed. The fuel tank isolation valve has a first port, a second port, an electrical actuator, and a valve body. The first port is in fluid communication with the fuel vapor collection canister and the second port is in fluid communication with the fuel tank. An electrical actuator moves the valve body to control fluid communication between the first port and the second port. And the canister vent valve controls the flow of ambient fluid about the valve vapor collection canister. The method includes supplying a first electrical signal to the electrical actuator such that the valve body permits substantially unrestricted fuel vapor flow between the first port and the second port, supplying a second electrical signal to the electrical actuator such that the valve body substantially prevents fuel vapor flow between the first port and the second port, supplying a third electrical signal to the electrical actuator such that the valve body provides restricted fuel vapor flow between the first port and the second port, and supplying a fourth electrical signal to the tank vent valve to permit ambient fluid flow into the fuel vapor collection tank. In such systems, the fuel tank isolation valve is controlled by an electrical actuator, such as a solenoid valve, which is a typical assembly and which provides predetermined opening and closing settings and is costly. Controlling the solenoid valve is difficult.
In US20020088441a1, a system and method for controlling evaporative emissions of a volatile fuel is disclosed. The system preferably has a fuel vapor collection canister, a purge valve, an isolation valve, and a fuel tank. The isolation valve includes a housing, a valve body, and a seal. The housing has a first port in fluid communication with the supply port of the fuel vapor collection canister, a second port, and a fuel vapor flow path extending between the first port and the second port. The valve body is movable relative to the housing along an axis between a first configuration and a second configuration. The first configuration permits substantially unrestricted fuel vapor flow between the first port and the second port, and the second configuration substantially prevents fuel vapor flow between the first port and the second port. The fuel tank is in fluid communication with the second port of the isolation valve. In such systems, the fuel tank isolation valve is controlled by an electrical actuator, such as a solenoid valve, which is a typical assembly and which provides predetermined opening and closing settings and is costly. Controlling the solenoid valve is difficult.
Accordingly, the present invention overcomes the disadvantages of the referenced art and provides an improved fuel tank isolation valve that incorporates a stepper motor operating as an actuator. This will result in a compact design, precise functional control, cost efficiency, less weight and a reduced number of components in the overall assembly.
Object of the Invention
It is a primary object of the present invention to provide an improved fuel tank isolation valve assembly which allows for precise control flow and is of a low cost compact design.
It is another principal object of the present invention to provide an assembly including a nozzle, a threaded plunger and a stepper motor to control the opening and closing of a fuel tank isolation valve.
It is a further principal object of the present invention to provide an assembly for controlling the opening and closing of a valve by linear movement of a threaded plunger.
It is a further object of the present invention to provide an assembly that allows automatic opening and closing of the valve by means of a compression spring when the pressure or vacuum inside the fuel tank exceeds a limit.
Disclosure of Invention
The present invention relates to an improved Fuel Tank Isolation Valve (FTIV) assembly. More particularly, the present invention relates to a stepper-motor driven valve having application in an EVAP system and to maintain pressure inside a fuel tank in a protected pressure range during refueling, both under overpressure and over-vacuum conditions, along with a controlled flow of fuel vapor from the tank to a canister.
In a primary embodiment, the present invention provides an assembly of FTIVs. The assembly includes a nozzle having an integrated tank port for connecting the valve to the fuel tank, a tank port for connecting the valve to the tank, and a stepper motor for electrical opening and closing of the valve. The stepper motor includes a motor housing, a rotor with internal threads, a ball bearing and a moving plunger with threads on its outer diameter. The sub-assembly further comprises: a seal sub-assembly for over-pressure relief (OPR), wherein a compression spring is secured thereover and in contact with the sealing surface to perform an over-pressure relief function; a seal sub-assembly for over-vacuum relief (OVR) wherein a compression spring is secured thereunder and in contact with a sealing surface to perform an over-vacuum function. The motor housing has a rotor with internal threads and a ball bearing that reduces friction when rotating. The threaded plunger secured to the cavity is fastened to the threaded rotor of the motor, thus completing the assembly of the FTIV. Linear movement of a threaded plunger in a motor housing causes opening and closing of the valve.
In yet another embodiment, the present invention provides an improved FTIV assembly in an idle condition. The idle condition allows the seal sub-assembly for the OVR and the seal sub-assembly for the OPR to close, thus not connecting the tank opening to the tank opening. The compression spring for the OVR cradles the seal sub-assembly (OVR) and, at the same time, the compression spring for the OPR cradles the seal sub-assembly (OPR) and keeps the valve closed.
In yet another embodiment, the present invention provides an improved FTIV assembly in an open condition or a refueled condition. The fueling condition allows energization of the motor to cause opening of the valve. As the rotor of the motor rotates, the plunger moves up and down depending on the direction of rotation of the motor for opening and closing the valve during refueling.
In yet another embodiment, the present invention provides an improved FTIV assembly in OPR conditions. The OPR condition allows compression of a compression spring for the OPR and lifting of a seal sub-assembly (OPR) upward, which creates a flow of fuel vapor from the tank port to the canister port when the pressure exceeds a predetermined limit.
In yet another embodiment, the present invention provides an improved FTIV assembly in OVR conditions. The OVR condition allows for compression of a compression spring for the OVR and moves a seal sub-assembly (OVR) downward, which creates a flow of fuel vapor from the canister port to the tank port when the vacuum exceeds a predetermined limit.
Brief description of the drawings
FIGS. 1(a) and 1(b) are perspective and exploded views, respectively, of a fuel tank isolation valve according to the present invention.
FIG. 2(a) is a cross-sectional view of a fuel tank isolation valve according to the present invention.
FIG. 2(b) is an enlarged cross-sectional view of a fuel tank isolation valve according to the present invention.
Fig. 3(a) and 3(b) are a cross-sectional view and an enlarged cross-sectional view, respectively, of a fuel tank isolation valve in a rest condition according to the present invention.
FIG. 4(a) is a cross-sectional view of a fuel tank isolation valve during refueling in accordance with the present invention.
Fig. 4(b), 4(c), 4(d) and 4(e) are enlarged cross-sectional views of a fuel tank isolation valve during refueling in accordance with the present invention.
FIG. 5(a) is a cross-sectional view of a fuel tank isolation valve operating in an OPR condition according to the present invention.
Fig. 5(b) and 5(c) are enlarged cross-sectional views of a fuel tank isolation valve operating in OPR conditions in accordance with the present invention.
FIG. 6(a) is a cross-sectional view of a fuel tank isolation valve operating in an OVR condition according to the present invention.
Fig. 6(b) and 6(c) are enlarged cross-sectional views of a fuel tank isolation valve operating in an OVR condition according to the present invention.
Detailed Description
Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed upon clearly illustrating the components of the present invention. Moreover, like reference numerals designate corresponding parts throughout the several views of the drawings. Before explaining at least one embodiment of the invention, it is to be understood that the embodiments of the invention are not limited in their application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. Embodiments of the invention are capable of being practiced and carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
The present invention relates to an improved Fuel Tank Isolation Valve (FTIV) assembly. More particularly, the present invention relates to a stepper-motor driven valve having application in an EVAP system and to maintain pressure inside a fuel tank in a protected pressure range during refueling, both under overpressure and over-vacuum conditions, along with a controlled flow of fuel vapor from the tank to a canister.
In a primary embodiment, the present invention provides an assembly of FTIVs. The assembly includes a nozzle having an integrated tank port for connecting the valve to the fuel tank, a tank port for connecting the valve to the tank, and a stepper motor for electrical opening and closing of the valve. The stepper motor includes a motor housing, a rotor with internal threads, a ball bearing, and a moving plunger with threads on its outer diameter. The sub-assembly further comprises: a seal sub-assembly for over-pressure relief (OPR), wherein a compression spring is secured thereover and in contact with the sealing surface to perform an over-pressure relief function; a sealer sub-assembly for over-vacuum relief (OVR) wherein a compression spring is secured thereunder and in contact with a sealing surface to perform an over-vacuum function. The motor housing has a rotor with internal threads and ball bearings that reduce friction when rotated. The threaded plunger secured to the cavity is fastened to the threaded rotor of the motor, thus completing the assembly of the FTIV. Linear movement of a threaded plunger in a motor housing causes opening and closing of the valve.
In yet another embodiment, the present invention provides an improved FTIV assembly in an idle condition. The idle condition allows the seal sub-assembly for the OVR and the seal sub-assembly for the OPR to close, thus not connecting the tank opening to the tank opening. The compression spring for the OVR cradles the seal sub-assembly (OVR) and, at the same time, the compression spring for the OPR cradles the seal sub-assembly (OPR) and keeps the valve closed.
In yet another embodiment, the present invention provides an improved FTIV assembly in an open condition or a refueled condition. The fueling condition allows energization of the motor to cause opening of the valve. As the rotor of the motor rotates, the plunger moves up and down depending on the direction of rotation of the motor for opening and closing the valve during refueling.
In yet another embodiment, the present invention provides an improved FTIV assembly in OPR conditions. The OPR condition allows compression of a compression spring for the OPR and lifting of a seal sub-assembly (OPR) upward, which creates a flow of fuel vapor from the tank port to the canister port when the pressure exceeds a predetermined limit.
In yet another embodiment, the present invention provides an improved FTIV assembly in OVR conditions. The OVR condition allows for compression of a compression spring for the OVR and moves a seal sub-assembly (OVR) downward, which creates a flow of fuel vapor from the canister port to the tank port when the vacuum exceeds a predetermined limit.
Referring to FIG. 1(a), a cross-sectional view of a fuel tank isolation valve (10) according to the present invention is shown. The fuel tank isolation valve comprises a valve housing (11) which is mounted on a motor housing (12), wherein the valve housing (11) comprises a tank opening (13) and a tank opening (14), and the motor housing (12) has an electrical connection opening (15).
Referring to FIG. 1(b), an exploded view of a fuel tank isolation valve (10) according to the present invention is shown. The assembly comprises a nozzle having an integrated tank mouth (14) for connecting the valve to the fuel tank, a tank mouth (13) for connecting the valve to the tank, and a stepper motor (17) for electrical opening and closing of the valve. The sub-assembly further comprises: a seal sub-assembly (4) for over-pressure relief (OPR), wherein a compression spring (3) is fixed above and in contact with the sealing surface to perform an over-pressure relief function; a seal sub-assembly (7) for over-vacuum relief (OVR) in which a compression spring (6) is fixed thereunder and in contact with a sealing surface to perform an over-vacuum function. The motor housing (12) has a rotor (20) with internal threads and ball bearings that reduce friction when rotated. A threaded plunger (16) secured to the cavity is fastened to the threaded rotor of the motor, thus completing the assembly of the FTIV (10).
Referring now to fig. 2(a), the present invention provides a cross-sectional view of an FTIV assembly. The assembly (10) comprises a nozzle having an integrated tank mouth (14) for connecting the valve to the fuel tank, a tank mouth (13) for connecting the valve to the tank and a stepper motor (17) for electrical opening and closing of the valve. The stepping motor (17) comprises a motor housing (12), a rotor (20) with an internal thread, a ball bearing (9) and a moving plunger (16) with a thread on its outer diameter. The sub-assembly further comprises: a seal sub-assembly (4) for over-pressure relief (OPR), wherein a compression spring (3) is fixed above it and in contact with a sealing surface (5) to perform an over-pressure relief function; a seal sub-assembly (7) for over-vacuum relief (OVR) in which a compression spring (6) is fixed thereunder and in contact with a sealing surface (8) to perform an over-vacuum function. The motor housing (12) has a rotor (20) with an internal thread and a ball bearing (9) that reduces friction when rotating. A threaded plunger (16) secured to the cavity is fastened to a threaded rotor (20) of the motor, thus completing the assembly of the FTIV. Linear movement of a threaded plunger (16) in the motor housing causes opening and closing of the valve (10).
Referring to FIG. 2(b), an enlarged cross-sectional view of a fuel tank isolation valve according to the present invention is shown. A sealing sub-assembly (4) is fitted on the sealing surface (5) for the OPR function to provide a seal against the OPR function. And, a sealing sub-assembly (7) is fitted under the sealing surface (8) for the OVR function to provide a seal for both the OVR function and the refuelling function.
Reference is now made to fig. 3(a) and 3(b) which show a cross-sectional view and an enlarged cross-sectional view of a fuel tank isolation valve in an idle condition in accordance with the present invention. The compression spring (6) for the OVR keeps the seal sub-assembly (7) for the OVR in contact with the sealing surface (8) and, at the same time, the compression spring (3) for the OPR keeps the seal sub-assembly (4) for the OPR in contact with the sealing surface (5), thus not connecting the tank mouth (14) to the tank mouth (13) and keeping the fuel vapours inside the fuel tank. The threaded plunger (16), having an annular flange (22) at the top end, is mounted in a seal sub-assembly (7) and, at the bottom end, is fastened in a threaded cavity (21) in the rotor (20) to provide an inline function.
Referring to fig. 4(a) to 4(e), there are shown cross-sectional and enlarged cross-sectional views of a fuel tank isolation valve during refueling in accordance with the present invention. During refueling, the motor (17) is energized and the rotor (20) begins to rotate with the shaft, which moves the threaded plunger (16) downward, moving the seal sub-assembly (7) for the OVR downward by compressing the compression spring (6) and allowing flow conditions from the tank mouth (14) to the tank mouth (13), as depicted in fig. 4 (a).
In a first condition, a small linear stroke of the plunger (16) occurs with +2 rotations of the leak point of the motor (17), and a small opening path opens and achieves a first condition of flow rate, as depicted in fig. 4 (b). By further rotation of the motor (17), i.e. at +20 rotations of the motor, an additional stroke of the plunger (16) occurs and the open path area increases, which achieves the second condition of flow rate, as depicted in fig. 4 (c). By full rotation of the motor (17), the plunger (16) makes its full stroke and there is full opening of the valve (10) and a flow resistance condition is achieved as depicted in fig. 4 (d). The flow path in the fueled condition is as shown in fig. 4 (e).
Referring to fig. 5(a) to 5(c), there are shown cross-sectional and enlarged cross-sectional views of a fuel tank isolation valve (10) operating in OPR conditions in accordance with the present invention. When the fuel tank isolation valve (10) is in the OPR condition, there is pressure build-up inside the valve (10) in the region (18) between the spring seat (19) and the seal sub-assembly (4) for the OPR function, and the compression spring (3) for the OPR function maintains the seal sub-assembly (4) in contact with the sealing surface (5), thereby maintaining the fuel tank isolation valve (10) in a closed condition, as depicted in fig. 5 (a). When the pressure increases beyond the predetermined protection point limit, the pressure exerts a force to compress the compression spring (3) for the OPR function and lift the seal sub-assembly (4) for the OPR function upward, as depicted in fig. 5 (b). As the sealing subassembly (4) for the OPR function lifts upward, the valve opens and flow begins from the tank port (14) to the tank port (13). Excess fuel vapor enters the canister and the pressure begins to drop, as depicted in fig. 5 (c). As soon as the pressure drops to the protection point limit (i.e. the safety limit), the valve closes again.
Referring to fig. 6(a) to 6(c), there are shown cross-sectional and enlarged cross-sectional views of a fuel tank isolation valve (10) operating in an OVR condition in accordance with the present invention. When the fuel tank isolation valve (10) is in the OVR condition, there is a vacuum built up inside the valve (10) in the region (18) between the spring seat (19) and the seal sub-assembly (7) for the OVR function, and the compression spring (6) for the OVR function holds the seal sub-assembly (7) for the OVR function in contact with the sealing surface (8) to hold the fuel tank isolation valve (10) in the closed condition, as depicted in fig. 6 (a). There is a stroke provided between the seal subassembly (7) for OVR and the plunger (16) to use full spring force for sealing without any reliance on the thread provided at the bottom end of the plunger (16). Furthermore, the same stroke is used for the OVR function, as it is controlled according to the flow resistance function. When the vacuum increases beyond the guard point limit, the vacuum exerts a force to compress the compression spring (6) and the seal sub-assembly (7) for the OVR function moves downward due to the stroke between the seal sub-assembly (7) and the plunger (16) for the OVR function, as depicted in fig. 6 (b). Here, the plunger remains in its position and the movement of the seal sub-assembly (6) for the OVR function is equal to the stroke between the seal sub-assembly (7) for the OVR function and the plunger (16). As the seal subassembly (7) for the OVR moves downward, the valve opens and flow begins from the canister port (13) to the tank port (14), as depicted in fig. 6 (c). The vacuum begins to release from the tank and once the vacuum reaches the guard point limit (i.e., the safety limit), the valve closes again.
Accordingly, the FTIV assembly allows for opening and closing of the valve by linear movement of the plunger.
Example 1
Fueling during key-on conditions
During refueling, the stepper motor becomes on. Due to the rotation of the stepper motor, the plunger with the lead screw moves downward, thereby moving the seal assembly for the OVR function downward by compressing the compression spring for the OVR function. In the first condition, by the leak point of the motor +2 rotations, a small linear stroke of the plunger occurs and the small opening path becomes open, which achieves the condition of maximum 11.4L/min at 16 kPa. By further rotation of the motor, i.e. at +20 rotations of the motor, additional strokes of the plunger occur and the opening path area increases, this achieves a condition of maximum 155L/min at 16 kPa. By full rotation of the motor (step 416), the plunger makes its full stroke and full opening of the valve occurs and a flow resistance condition of 78L/min at a pressure difference of maximum 0.35kPa is achieved.
The foregoing descriptions of embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.
Claims (6)
1. An improved fuel tank isolation valve (10) with an integrated stepper motor (17), comprising:
a valve housing (11) comprising a tank opening (13) and a tank opening (14) and comprising a compression spring (3), a seal sub-assembly (4) for performing an over-pressure relief (OPR) function, a seal sub-assembly (7) for performing an over-vacuum relief (OVR) function and a compression spring (6);
a motor housing (12) having an electrical connection port (15);
a threaded plunger (16); and
a spring seat (19);
wherein the content of the first and second substances,
the stepper motor (17) comprising the motor housing (12), a threaded rotor (20) and a plurality of ball bearings (9) positioned between the motor housing (12) and the threaded rotor (20), the plurality of ball bearings (9) for reducing friction when the threaded rotor (20) is in use;
-said threaded plug (16), having an annular flange (22) at the top end, mounted in said seal subassembly (7), and at the bottom end it is fastened in a threaded cavity (21) in said threaded rotor (20) to provide an inline function; and
the valve (10) allows for opening and closing of the valve by linear movement of a threaded plunger (16).
2. The improved fuel tank isolation valve (10) with integrated stepper motor (17) as claimed in claim 1, wherein said spring seat (19) secures said compression spring (6) and said threaded plunger (16) passes through said spring seat (19).
3. The improved fuel tank isolation valve (10) with integrated stepper motor (17) as claimed in claim 1, wherein said seal sub-assembly (4) has said compression spring (3) fixed above it, said seal sub-assembly (4) being in contact with a sealing surface (5) for Over Pressure Relief (OPR) function.
4. The improved fuel tank isolation valve (10) with integrated stepper motor (17) as claimed in claim 1, wherein a seal sub-assembly (7) has said compression spring (6) fixed thereunder, said seal sub-assembly (7) being in contact with a sealing surface (8) to perform an over-vacuum relief (OVR) function.
5. The improved fuel tank isolation valve (10) with integrated stepper motor (17) as claimed in claim 1, wherein an annular cavity is provided for the ball bearing (9) between the motor housing (12) and the threaded rotor (20).
6. The improved fuel tank isolation valve (10) with integrated stepper motor (17) as set forth in claim 1, wherein said stepper motor (16) maintains pressure within a protected pressure range, provides electrical control of fuel vapor flow from tank to canister during refueling, provides Over Pressure Relief (OPR) and Over Vacuum Relief (OVR).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IN201911035587 | 2019-09-04 | ||
| PCT/IB2020/058490 WO2021044395A1 (en) | 2019-09-04 | 2020-09-12 | An improved fuel tank isolation valve with an integrated stepper motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114502406A true CN114502406A (en) | 2022-05-13 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202080003905.8A Pending CN114502406A (en) | 2019-09-04 | 2020-09-12 | Improved fuel tank isolation valve with integrated stepper motor |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP7476300B2 (en) |
| CN (1) | CN114502406A (en) |
| WO (1) | WO2021044395A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113915031B (en) * | 2021-10-18 | 2022-06-17 | 苏州恩都法汽车系统有限公司 | Oil tank isolation valve control system |
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| US20020088441A1 (en) * | 2000-08-08 | 2002-07-11 | Craig Weldon | Evaporative emission control system including a fuel tank isolation valve |
| WO2016049320A1 (en) * | 2014-09-24 | 2016-03-31 | Eaton Corporation | Electrically controlled fuel system module |
| CN106132751A (en) * | 2014-01-30 | 2016-11-16 | 拉瓦尔A.C.S.公司 | Pressure relief valve |
| CN110486483A (en) * | 2019-09-02 | 2019-11-22 | 苏州恩都法汽车系统有限公司 | A kind of motor-driven pressure-oil tank isolating valve |
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| GB9705409D0 (en) | 1997-03-15 | 1997-04-30 | Britax Wingard Ltd | Pressure relief valve |
| JP4168884B2 (en) | 2003-09-04 | 2008-10-22 | 豊田合成株式会社 | Fuel cap |
| DE102010044336A1 (en) | 2010-09-03 | 2012-03-08 | A. Kayser Automotive Systems Gmbh | Ventilation arrangement for a fuel tank |
| JP5583552B2 (en) | 2010-11-05 | 2014-09-03 | 愛三工業株式会社 | Solenoid valve and evaporative fuel processing apparatus equipped with the solenoid valve |
| DE102011114120A1 (en) | 2011-09-24 | 2013-03-28 | A. Kayser Automotive Systems Gmbh | Ventilation arrangement for fuel tank of hybrid car, has drive generating movement for switchable valve, where complete opened connection is established between connectors using switching movement for releasing input port of connector |
| JP6231404B2 (en) | 2014-02-28 | 2017-11-15 | 愛三工業株式会社 | Fresh air introduction device |
| JP6320910B2 (en) | 2014-12-25 | 2018-05-09 | 愛三工業株式会社 | Evaporative fuel processing equipment |
| JP6275633B2 (en) | 2014-12-25 | 2018-02-07 | 愛三工業株式会社 | Flow control valve and evaporated fuel processing device |
| CN107084267B (en) | 2017-04-13 | 2019-04-09 | 海拉（厦门）汽车电子有限公司 | A kind of highly integrated fuel tank isolation valve |
| US10717354B2 (en) | 2017-09-20 | 2020-07-21 | Padmini Vna Mechatronics Pvt. Ltd. | Fuel tank isolation valve with single seal, improved axis alignment and robust leak proof solenoid |
-
2020
- 2020-09-12 WO PCT/IB2020/058490 patent/WO2021044395A1/en active Application Filing
- 2020-09-12 JP JP2022514809A patent/JP7476300B2/en active Active
- 2020-09-12 CN CN202080003905.8A patent/CN114502406A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020088441A1 (en) * | 2000-08-08 | 2002-07-11 | Craig Weldon | Evaporative emission control system including a fuel tank isolation valve |
| CN106132751A (en) * | 2014-01-30 | 2016-11-16 | 拉瓦尔A.C.S.公司 | Pressure relief valve |
| WO2016049320A1 (en) * | 2014-09-24 | 2016-03-31 | Eaton Corporation | Electrically controlled fuel system module |
| CN110486483A (en) * | 2019-09-02 | 2019-11-22 | 苏州恩都法汽车系统有限公司 | A kind of motor-driven pressure-oil tank isolating valve |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2022546737A (en) | 2022-11-07 |
| WO2021044395A1 (en) | 2021-03-11 |
| JP7476300B2 (en) | 2024-04-30 |
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