CN114502408A - Improved fuel tank isolation valve using integrated stepper motor - Google Patents
Improved fuel tank isolation valve using integrated stepper motor Download PDFInfo
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- CN114502408A CN114502408A CN202080045786.2A CN202080045786A CN114502408A CN 114502408 A CN114502408 A CN 114502408A CN 202080045786 A CN202080045786 A CN 202080045786A CN 114502408 A CN114502408 A CN 114502408A
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- fuel tank
- isolation valve
- function
- seal
- tank isolation
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- 239000002828 fuel tank Substances 0.000 title claims abstract description 102
- 238000002955 isolation Methods 0.000 title claims abstract description 75
- 239000000446 fuel Substances 0.000 claims abstract description 25
- 230000006835 compression Effects 0.000 claims description 44
- 238000007906 compression Methods 0.000 claims description 44
- 238000007789 sealing Methods 0.000 claims description 38
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 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
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Classifications
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- 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
- B60K15/03519—Valve arrangements in the vent line
-
- 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
- B60K2015/03256—Fuel tanks characterised by special valves, the mounting thereof
- B60K2015/03296—Pressure regulating valves
-
- 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
-
- 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
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Transportation (AREA)
- General Engineering & Computer Science (AREA)
- Supplying Secondary Fuel Or The Like To Fuel, Air Or Fuel-Air Mixtures (AREA)
Abstract
The invention relates to the technical field of an improved fuel tank isolation valve. The invention provides an improved two-stage fuel tank isolation valve, which integrates a further motor to maintain the pressure within a pressure protection range, and performs two-stage electric control on fuel vapor through multiple steps, thereby opening the flow of the fuel vapor from a fuel tank to a storage tank during refueling and providing the functions of pressure relief and vacuum pressure relief.
Description
Technical Field
The present invention relates to an improved fuel tank isolation valve; in particular to an improved two-stage fuel tank isolation valve which integrates a stepping motor for driving a plunger to move and has the functions of pressure relief, vacuum pressure relief and two-stage flow resistance control.
Background
Most of the time, hybrid vehicles operate on electric power, while the internal combustion engine is idle. Since the fuel tank is a closed system, a positive pressure is generally generated inside the fuel tank due to evaporation of the stored fuel. Furthermore, it is necessary for the vehicle to maintain an elevated pressure in the fuel tank so that the rate of fuel vapor generation is inhibited and the amount of hydrocarbons vented to the atmosphere is minimized. The easiest solution to overcome this problem is to provide a Fuel Tank Isolation Valve (FTIV) connected to the fuel tank to control the venting of the fuel tank. In a vapor emission control system, the fuel tank isolation valve may be disposed in a conduit between the fuel tank and the fuel vapor canister. The tank isolation valve will automatically open when the pressure exceeds a protective limit and will be electrically actuated when refueled.
The fuel tank isolation valve also enables the fuel tank to contain fuel vapor until the engine is insufficient to handle more vapor. Generally, the tank isolation valve includes electrically controlled solenoid valves for opening and closing the inlet and outlet ports, but either the opening of the intermediate position cannot be precisely controlled or the opening of the intermediate position is not controlled. Therefore, the flow rate of the fuel vapor flowing from the fuel tank into the vapor canister at the time of refueling cannot be accurately controlled.
In the former publication US20020088441a1, a system and method for controlling vapors emitted by a volatile fuel is disclosed. The system preferably includes a fuel vapor collection canister, a purge valve, an isolation valve, and a fuel tank. The isolating valve comprises a shell, a valve body and a sealing element. The housing has a first connection port, a second connection port, and a fuel vapor flow passage, the first connection port communicates with the supply connection port of the fuel vapor collection canister, and the fuel vapor flow passage is located between the first connection port and the second connection port. The valve body is movable relative to the housing along an axis between a first configuration and a second configuration. The first configuration allows unrestricted fuel vapor flow between the first and second ports, and the second configuration substantially prevents fuel vapor flow between the first and second ports. The fuel tank communicates with the second connection port of the isolation valve. The main disadvantage of the prior art is that the tank isolation valves in the system are controlled by an electric drive, such as a solenoid valve, which typically provides a preset opening and closing setting and is expensive. Furthermore, it is also difficult to control the solenoid valve.
Accordingly, the present invention overcomes the disadvantages of the prior art and provides an improved fuel tank isolation valve that incorporates a stepper motor. This allows for a more compact design with precise functional control, cost effectiveness, weight savings and a reduction in the number of components to be assembled as a whole.
Disclosure of Invention
It is therefore an object of the present invention to provide an improved two-stage fuel tank isolation valve that is integrated with a stepper motor for providing plunger movement, and that has pressure relief, vacuum relief, and two-stage flow resistance control.
It is another object of the present invention to provide an improved two-stage fuel tank isolation valve that is integrated with a stepper motor to maintain pressure within a pressure protected range and to electronically control fuel vapor in two stages through multiple steps, precisely control the flow of fuel vapor from the fuel tank to the reservoir during refueling, and provide pressure and vacuum relief functions.
It is a further object of the present invention to provide an improved two-stage fuel tank isolation valve which is of robust and compact design.
It is a further object of the present invention to provide an improved two-stage fuel tank isolation valve in which the movement of the plunger is controlled in multiple steps for flow control purposes.
It is a further object of the present invention to provide a two-piece fuel tank isolation valve that is lightweight and reduced in size.
In view of the foregoing, the present invention provides an improved two-stage fuel tank isolation valve that integrates a stepper motor to maintain pressure within a pressure protected range and electronically controls fuel vapor in multiple steps in two stages to control the flow of fuel vapor from the fuel tank to the reservoir during the refueling process and to provide a pressure relief function and a vacuum relief function.
In one embodiment of the present invention, an improved two-piece fuel tank isolation valve includes a valve body and a motor housing, wherein the valve body has a canister connection port and a fuel tank connection port and is mounted on the motor housing, the valve body including a compression spring for an over-pressure relief (OPR) function, the compression spring being fixed within the valve body to perform the relief function; a first seal assembly for pressure relief; a sealing surface for pressure relief; a second seal assembly for an over-vacuum relief (OVR) function and an oiling function; a sealing member for vacuum pressure release function; a nozzle; a first compression spring for vacuum pressure release; a sealing surface for vacuum relief; a stopper bush; a second compression spring is used for the oiling function; a sealing surface for oiling; a plunger; the motor housing includes a stepper motor; the motor rotor is provided with an axial thread cavity; a cover body; a plurality of ball bearings are disposed between the annular cavity between the motor housing and the stepper motor rotor to reduce friction generated by the stepper motor rotor during operation. The bottom end of the plunger is screwed with the thread cavity of the rotor of the stepping motor.
The improved two-stage fuel tank isolation valve integrated with the stepper motor maintains pressure within a pressure protected range, provides electrical control to control the flow of fuel vapor from the fuel tank to the storage tank during refueling, and provides pressure and vacuum relief functions.
In another embodiment, the present invention provides an improved two-piece fuel tank isolation valve having two components for pressure and vacuum relief functions, respectively, wherein the component for the pressure relief function has a compression spring and a seal component is provided separately from the component for the vacuum relief function and is attached to a sealing surface. The assembly for the vacuum relief function uses a first compression spring, and both the first compression spring and a second compression spring are used for the refueling function.
Accordingly, the present invention provides an improved, reduced size, reduced weight two-piece fuel tank isolation valve that effectively and accurately controls flow through multiple steps.
Drawings
The invention is described with reference to the following figures. The drawings and the related description are provided to illustrate embodiments of the invention and not to limit the scope of the invention:
FIG. 1(a) is a perspective view of a two-piece fuel tank isolation valve of the present invention.
FIG. 1(b) is an exploded view of the two-piece fuel tank isolation valve of the present invention.
FIG. 2(a) is a cross-sectional view of a two-piece fuel tank isolation valve of the present invention.
FIG. 2(b) is an enlarged partial cross-sectional view of the two-piece fuel tank isolation valve of the present invention.
FIGS. 3(a) and 3(b) are enlarged partial cross-sectional views of a two-piece fuel tank isolation valve of the present invention in an idle state.
FIG. 4(a) is a cross-sectional view of a two-piece fuel tank isolation valve of the present invention during refueling.
FIGS. 4(b) -4 (e) are enlarged partial cross-sectional views of the two-piece fuel tank isolation valve of the present invention during refueling.
FIG. 5(a) is a cross-sectional view of a two-stage fuel tank isolation valve of the present invention in a pressure relief state.
FIGS. 5(b) and 5(c) are enlarged partial cross-sectional views of the two-stage fuel tank isolation valve of the present invention in a pressure-released state.
FIG. 6(a) is a cross-sectional view of a two-stage fuel tank isolation valve of the present invention in a vacuum-released state.
FIGS. 6(b) and 6(c) are enlarged partial cross-sectional views of the two-stage fuel tank isolation valve of the present invention in a vacuum-released state.
Detailed Description
In order to more clearly illustrate the present invention, preferred embodiments are described in detail below with reference to the accompanying drawings. The components in the figures are not necessarily to scale, emphasis instead being 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. The embodiments of the invention may be 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 provides a two-stage fuel tank isolation valve integrated with a stepping motor to maintain the pressure within a pressure protection range and to electrically control the fuel vapor in two stages through a plurality of steps, thereby precisely controlling the flow rate of the fuel vapor flowing from the fuel tank to the storage tank during refueling and providing a pressure release function and a vacuum pressure release function.
In one embodiment of the present invention, an improved two-piece fuel tank isolation valve includes a valve body and a motor housing, wherein the valve body has a canister connection port and a fuel tank connection port and is mounted on the motor housing, the valve body including a compression spring for an over-pressure relief (OPR) function, the compression spring being fixed within the valve body to perform the relief function; a first seal assembly for pressure relief; a sealing surface for pressure relief; the second sealing component is used for the vacuum pressure relief function and the oil filling function; a sealing member for vacuum pressure release function; a nozzle; a first compression spring for vacuum pressure release; a sealing surface for vacuum relief; a stopper bush; a second compression spring is used for the oiling function; a sealing surface for a refueling function; a plunger; the motor housing includes a stepper motor; the motor rotor is provided with an axial thread cavity; a cover body; a plurality of ball bearings are disposed between the annular cavity between the motor housing and the stepper motor rotor to reduce friction generated by the stepper motor rotor during operation. The bottom end of the plunger is screwed with the thread cavity of the rotor of the stepping motor. A tank isolation valve integrated with the stepper motor maintains pressure within a protected pressure range, provides electrical control of fuel vapor flowing from the fuel tank to the reservoir during refueling, provides a pressure relief function, and provides a vacuum relief function.
In another embodiment, the present invention provides an improved two-piece fuel tank isolation valve having two components for pressure and vacuum relief functions, respectively, wherein the component for the pressure relief function has a compression spring and a sealing component is provided separately from the component for the vacuum relief function and is attached to a sealing surface. The assembly for the vacuum relief function uses a first compression spring, and both the first compression spring and a second compression spring are used for the refueling function.
Accordingly, the present invention provides an improved, reduced size, reduced weight two-piece fuel tank isolation valve that is effective to accurately control flow through a multi-step stepper motor.
Referring now to FIG. 1(a), there is shown a perspective view of a two-piece fuel tank isolation valve 10 of the present invention. The two-stage fuel tank isolation valve 10 includes a valve body 11 mounted on a motor housing 12, wherein the valve body 11 includes a canister connection port 13 and a fuel tank connection port 14, and the motor housing 12 has an electrical connection port 15.
Referring now to FIG. 1(b), there is shown an exploded view of a two-piece fuel tank isolation valve 10 of the present invention. The two-piece fuel tank isolation valve 10 includes a tank connection port 13, the tank connection port 13 being mounted on a compression spring 4 for pressure relief, the compression spring 4 being mounted on a first seal assembly 5 for pressure relief. The fuel tank connection port 14 is located below the first seal member 5 and is connected to the fuel tank. A second seal assembly 2 is provided, said second seal assembly 2 being mounted to a seal 3 for vacuum relief functionality. A first compression spring 1 is located below the seal 3 and surrounds the seal 3, a stop bush 18 surrounds the first compression spring 1, and a second compression spring 19 is arranged below the stop bush 18 in a spring seat 29. The stepping motor 26 comprises the motor housing 12 and the stepping motor rotor 21, and a bottom end of a plunger 7 has a thread corresponding to the thread cavity of the stepping motor rotor 21, and the bottom end of the plunger 7 is correspondingly disposed in the thread cavity.
Referring to FIG. 2(a), a two-stage fuel tank isolation valve 10 of the present invention is shown in cross-section. The compression spring 4 for the pressure relief function of the two-stage fuel tank isolation valve 10 is mounted on a first seal assembly 5, and the first seal assembly 5 is connected with a sealing surface 9, the two-stage fuel tank isolation valve 10 comprises a nozzle 16, the second seal assembly 2 is mounted on the seal 3, the top of the seal 3 is provided with an annular flange which is mounted on the second seal assembly 2, the seal 3 is provided with a cavity, the bottom end of the cavity is provided with an inward bulge which is connected with the plunger 7 and clamps the plunger 7, the first compression spring 1 for the vacuum pressure relief function is positioned below the seal 3 and surrounds the seal 3, the stop bush 18 surrounds the first compression spring 1 and is assembled with the second seal assembly 2 after the seal 3 is inserted, the second compression spring 19 is installed below the second seal assembly 2 and above the spring seat 29, the top end of the plunger 7 passes through the spring seat 29 and is installed in an inward protrusion of the cavity at the bottom end of the seal 3 for vacuum relief, and the bottom end of the plunger 7 passes through the spring seat 29 and is installed in a threaded cavity of the rotor 21 of the stepping motor. The plunger 7 has a flange portion which is installed in the sealing member 3 for a vacuum relief function, and a bottom end of the plunger 7 has a plurality of threads corresponding to a threaded cavity of the stepping motor rotor 21. An annular chamber is provided between the motor housing 12 and the stepper motor rotor 21 for providing a plurality of ball bearings 22 to reduce friction when the stepper motor rotor 21 is in operation.
Referring now to FIG. 2(b), an enlarged partial cross-sectional view of two-stage fuel tank isolation valve 10 of the present invention is shown. The first seal assembly 5 is connected to the sealing surface 9 to provide a pressure relief function seal. The second seal member 2 for the vacuum relief function is in contact with the seal member 3 for the vacuum relief function to provide a first sealing function at the time of the vacuum relief function and the refueling function. In addition, the second seal assembly 2 for the vacuum relief function is in contact with a sealing surface 24, providing only a second sealing function as a refueling function.
FIGS. 3(a) and 3(b) are enlarged partial cross-sectional views of a two-stage fuel tank isolation valve of the present invention in a rest state. As shown in fig. 3(a), in an idle state, the first compression spring 1 for the vacuum relief function keeps the seal 3 in contact with the second seal assembly 2 for the vacuum relief function to seal a flow passage 23, and the second compression spring 19 for the flow resistance function keeps the second seal assembly 2 for the vacuum relief function in contact with the sealing surface 24 to seal a flow passage 25 and keep the two-stage fuel tank isolation valve in a closed state. The compression spring 4 for the relief function holds the first seal assembly 5 down and connected to the sealing face 9. Therefore, the three openings for the pressure release function and the vacuum pressure release function are all closed, and the tank connection port 13 of the two-stage fuel tank isolation valve 10 is not connected to the fuel tank connection port 14 of the two-stage fuel tank isolation valve 10. As shown in fig. 3(b), in the idle state, fuel vapor remains in the fuel tank until the pressure in the fuel tank reaches the pressure protection range limit.
FIGS. 4(a) through 4(e) are enlarged partial cross-sectional views of the two-piece fuel tank isolation valve of the present invention during refueling. During refueling, the stepping motor 26 is turned on, and with the stepwise rotation of the stepping motor rotor 21, the plunger 7 is moved downward and screwed into the stepping motor rotor 21, causing the seal 3 for vacuum relief function to compress the first compression spring 1 downward and move to the position shown in fig. 4(a) to open the flow passage 23. As shown in fig. 4(b), in the first case where the leakage point of the stepping motor 26 is positive 2 rotations, the plunger 7 performs a small linear stroke, and opens a small opening path, satisfying a first flow rate condition. As shown in fig. 4(c), as the stepping motor rotor 21 rotates further, that is, the leakage point of the stepping motor 26 rotates plus 20 revolutions, the plunger 7 makes further stroke and the open path area increases, thereby satisfying a second flow rate condition. As the plunger 7 is further moved, the sealing member 3 for the vacuum relief function comes into contact with the second sealing member 2 for the vacuum relief function, the sealing member 3 starts to push the second sealing member 2 to move downward by compressing the second compression spring 19 and opens the flow passage 25, and as the flow passage 23 is opened, the pressure difference established in the valve is reduced, and the second sealing member 2 opens the flow passage 25 under a lower driving force. As shown in fig. 4(d), with the full rotation of the stepping motor 26, i.e., 416 steps of rotation, the plunger 7 reaches the full stroke to fully open the valve, thereby satisfying a flow resistance condition. The flow path in the refueled state is shown in fig. 4 (e).
Referring to fig. 5(a) through 5(c), there are shown cross-sectional and partially enlarged cross-sectional views of the two-stage fuel tank isolation valve 10 operating under pressure relief in accordance with the present invention. When the two-stage fuel tank isolation valve 10 is in a pressure relief state, as shown in FIG. 5(a), pressure is built up in the area 27 between the spring seat 29 in the two-stage fuel tank isolation valve 10 and the first seal assembly 5 for the pressure relief function, and the compression spring 4 for the pressure relief function keeps the first seal assembly 5 in contact with the sealing surface 9, leaving the two-stage fuel tank isolation valve 10 in a closed state. As shown in fig. 5(b), when the pressure is increased beyond a pressure protection range, the compression spring 4 for the pressure release function is compressed by the received pressure and moves the first seal assembly 5 for the pressure release function upward. As shown in fig. 5(c), as the first seal member 5 for the pressure release function is lifted up to open the opening communicating between the fuel tank connection port 14 and the canister connection port 13, and air flows from the fuel tank connection port 14 to the canister connection port 13, so that excess fuel vapor enters the reservoir, the pressure starts to drop. Once the pressure drop reaches the pressure protection range, the opening communicating between the fuel tank connection port 14 and the canister connection port 13 is closed.
Referring to fig. 6(a) through 6(c), there are shown cross-sectional and partially enlarged cross-sectional views of a two-stage fuel tank isolation valve 10 of the present invention operating under vacuum relief. As shown in FIG. 6(a), when the two-stage fuel tank isolation valve 10 is in a vacuum relief condition, a vacuum condition is created inside the two-stage fuel tank isolation valve 10 in the area 27 between the spring seat 29 and the second seal assembly 2 for the vacuum relief function. The first compression spring 1 for the vacuum relief function maintains the seal 3 for the vacuum relief function in contact with the second seal subassembly 2 for the vacuum relief function, and the second compression spring 19 maintains the second seal 2 for the vacuum relief function in contact with the sealing surface 24 to maintain the two-piece fuel tank isolation valve 10 in a closed state. In order to achieve a secure seal, a stroke is provided between the seal 3 and the plunger 7 to seal completely with the spring force without relying on the thread at the bottom end of the plunger 7. Likewise, a stroke is provided between the seal 3 for the vacuum relief function and the stop bushing 18. In addition, the same stroke is used in performing the vacuum relief function because it is controlled according to the flow resistance function. As shown in fig. 6(b), when the degree of vacuum increases to exceed the pressure protection range, a force compressing the first compression spring 1 is generated, and the seal 3 for the vacuum relief function can move downward due to the stroke between the seal 3 and the plunger 7 for the vacuum relief function and the seal 3 and the stopper bush 18 for the vacuum relief function. As shown in fig. 6(c), the plunger 7 is held at its original position, and the maximum amount of movement is limited by the amount of stroke provided between the seal 3 and the stopper bush 18 for the vacuum relief function. When the seal member 3 for a vacuum relief function is moved downward, an opening communicating between the fuel tank connection port 14 and the canister connection port 13 is opened, and the gas flow starts from the canister connection port 13 to the fuel tank connection port 14. The vacuum starts to be released from the fuel tank and once the pressure protection range is reached, the opening communicating between the fuel tank connection port 14 and the canister connection port 13 is closed.
Example 1 during refueling, the stepper motor is started. The plunger is moved downward by the rotation of the stepping motor, so that the sealing member for the vacuum relief function is moved downward by compressing the first compression spring and opens the first flow passage. In the first case, if the leakage point of the stepper motor rotates by exactly 2 revolutions, the plunger makes a small linear stroke and opens a small opening path up to 16kPa to a flow condition of 11.4L/min. With further rotation of the stepper motor, i.e., 20 positive revolutions at the leakage point of the stepper motor, the plunger is stroked further and the opening area of the path increases to reach a flow condition of 155L/min at 16kPa maximum. As the plunger is moved further, the seal for the vacuum relief function comes into contact with the first seal assembly, and the seal also begins to move downward by compressing the second compression spring and opens another flow path. With the full rotation of the motor (step 416), the plunger reaches the full stroke, and the valve is fully opened, so that the condition that the highest pressure difference is 0.35kPa and the flow resistance is 78L/min is met.
Thus, the present invention provides a lightweight two-stage fuel tank isolation valve because the stepper motor employed in the present invention is lighter in weight and smaller in volume than a solenoid valve. In addition, the improved two-piece fuel tank isolation valve enables efficient and accurate flow control through multi-step control through the use of a stepper motor.
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. The above description is only for the purpose of illustrating preferred embodiments of the present invention, and all equivalent modifications to the embodiments described in the specification and claims should be understood as being included in the scope of the present invention.
Claims (8)
1. A two-piece stepper motor integrated fuel tank isolation valve (10), comprising:
(a) a valve housing (11) including a tank connection port (13) and a fuel tank connection port (14), and including a compression spring (4), a first seal assembly (5) for a pressure release function, a second seal assembly (2) for a vacuum pressure release function and a refueling function, a seal (3) for the vacuum pressure release function, a first compression spring (1), a stopper bush (18), a second compression spring (19) and a plunger (7);
(b) a motor housing (12) including an electrical connection port (15); and
(c) a spring seat (29);
wherein the motor housing (12) comprises a stepper motor rotor (21) having an axial threaded cavity and a plurality of ball bearings (22) between the motor housing (12) and the stepper motor rotor to reduce friction when the stepper motor rotor (21) is in operation;
the plunger (7) top end passes through the spring seat (29) and is mounted in an inward projection in a cavity at the bottom end of the seal (3) for vacuum relief, and the plunger bottom end comprises a plurality of threads corresponding to the threaded cavity of the stepper motor rotor (21);
the first sealing component (5) is in contact with a sealing surface (9) to provide sealing for a pressure relief function, and the second sealing component (2) for a vacuum pressure relief function is in contact with the sealing component (3) for the vacuum pressure relief function to provide a first section of sealing for realizing the vacuum pressure relief function and the oil filling function;
the second seal assembly (2) for performing the vacuum relief function is in contact with a sealing surface (24) to provide a second stage seal for the refueling function only.
2. The two-stage stepper motor integrated fuel tank isolation valve (10) as claimed in claim 1, wherein the stop bushing (18) surrounds the first compression spring (1) and the second compression spring (19) is mounted to the spring seat (29) and below the stop bushing (18).
3. The two-stage stepping motor integrated fuel tank isolation valve (10) according to claim 1, wherein the seal (3) for performing vacuum relief function has an annular flange at the top end, the annular flange being mountable on the second seal assembly (2) for performing vacuum relief function.
4. The two-stage stepping motor integrated fuel tank isolation valve (10) according to claim 1, wherein the first compression spring (1) for performing a vacuum relief function keeps the seal (3) for performing a vacuum relief function in contact with the second seal assembly (2) for performing a vacuum relief function to seal a flow passage (23) in a rest state.
5. The two-stage stepping motor integrated fuel tank isolation valve (10) as claimed in claim 1, wherein the second compression spring (19) for implementing a flow resistance function keeps the second sealing assembly (2) for implementing a vacuum relief function in contact with the sealing surface (24) to seal a flow passage (25) and keep the two-stage stepping motor integrated fuel tank isolation valve (10) closed in a rest state.
6. The two-stage stepper motor integrated fuel tank isolation valve (10) as defined in claim 1, wherein during refueling, the stepper motor rotor (21) is fully rotated and the plunger (7) reaches full stroke to open the two-stage stepper motor fuel tank isolation valve.
7. The two-stage stepper motor integrated fuel tank isolation valve (10) as claimed in claim 1, wherein the plunger (7) in a vacuum relief state remains in a home position and the maximum amount of plunger movement is limited by the amount of travel between the seal (3) and the stop bushing (18) for the vacuum relief function.
8. The two-stage stepper-motor integrated fuel tank isolation valve (10) as claimed in claim 1, wherein the two-stage stepper-motor integrated fuel tank isolation valve (10) maintains pressure within a pressure protection range and provides electrical control of fuel vapor flow from the fuel tank to the reservoir during refueling to provide pressure relief and vacuum pressure relief.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IN201911035736 | 2019-09-05 | ||
| PCT/IB2020/058489 WO2021044394A1 (en) | 2019-09-05 | 2020-09-12 | Improved fuel tank isolation valve with integrated stepper motor with valve in valve design |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114502408A true CN114502408A (en) | 2022-05-13 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202080045786.2A Pending CN114502408A (en) | 2019-09-05 | 2020-09-12 | Improved fuel tank isolation valve using integrated stepper motor |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN114502408A (en) |
| WO (1) | WO2021044394A1 (en) |
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| ES2200433T3 (en) * | 1998-04-15 | 2004-03-01 | Eaton Corporation | VENTILATION VALVE TO LIMIT FILLING FOR FUEL DEPOSITS. |
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| CN103370525A (en) * | 2011-02-17 | 2013-10-23 | 伊顿公司 | Isolation valve with motor driven sealing mechanism |
| CN105402050A (en) * | 2015-12-24 | 2016-03-16 | 江苏奥力威传感高科股份有限公司 | Fuel tank isolation electromagnetic valve |
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| CN206206018U (en) * | 2016-10-27 | 2017-05-31 | 比亚迪股份有限公司 | A kind of isolating valve for pressure-oil tank |
| CN108626450A (en) * | 2018-07-06 | 2018-10-09 | 苏州恩都法汽车系统有限公司 | A kind of integrated form fuel tank isolation 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 |
-
2020
- 2020-09-12 CN CN202080045786.2A patent/CN114502408A/en active Pending
- 2020-09-12 WO PCT/IB2020/058489 patent/WO2021044394A1/en active Application Filing
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES2200433T3 (en) * | 1998-04-15 | 2004-03-01 | Eaton Corporation | VENTILATION VALVE TO LIMIT FILLING FOR FUEL DEPOSITS. |
| CN102486145A (en) * | 2010-12-02 | 2012-06-06 | 现代自动车株式会社 | Fuel tank control valve for vehicle |
| CN103328805A (en) * | 2011-01-21 | 2013-09-25 | 伊顿公司 | Isolation valve with fast depressurization for high-pressure fuel tank |
| CN103370525A (en) * | 2011-02-17 | 2013-10-23 | 伊顿公司 | Isolation valve with motor driven sealing mechanism |
| WO2016049320A1 (en) * | 2014-09-24 | 2016-03-31 | Eaton Corporation | Electrically controlled fuel system module |
| CN105402050A (en) * | 2015-12-24 | 2016-03-16 | 江苏奥力威传感高科股份有限公司 | Fuel tank isolation electromagnetic valve |
| CN206206018U (en) * | 2016-10-27 | 2017-05-31 | 比亚迪股份有限公司 | A kind of isolating valve for pressure-oil tank |
| CN108626450A (en) * | 2018-07-06 | 2018-10-09 | 苏州恩都法汽车系统有限公司 | A kind of integrated form fuel tank isolation 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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| Publication number | Publication date |
|---|---|
| WO2021044394A1 (en) | 2021-03-11 |
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Application publication date: 20220513 |