A fuel tank isolation valve with an improved over vacuum relief sealing

Abstract

The present invention relates to a fuel tank isolation valve (1) with improved over vacuum relief sealing, that comprises a seal (9) which is secured onto a seal holder (7) and the seal holder (7) is placed around a seal holder shaft (8) and seals the sealing surface of said seal (9) with a lower surface of a flow limiter (5) and limits a maximum flow from said fuel tank isolation valve (1). The seal holder shaft (8) is assembled into a guiding cavity (10) of said flow limiter (5) configured to control the linear movement of said flow limiter (5). A moving core (11) has a shaft (12) and said shaft (12) is coupled to said seal holder (7) for connecting said seal holder (7) and said moving core (11).

Description

[0001] “A FUEL TANK ISOLATION VALVE WITH AN IMPROVED OVER VACUUM RELIEF SEALING”

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a fuel tank isolation valve. More specifically, the invention relates to a fuel tank isolation valve with an improved over vacuum relief sealing that ensures proper sealing and improves the over vacuum functionality of the fuel tank isolation valve.

[0004] BACKGROUND OF THE INVENTION

[0005] The fuel tank isolation valve is a crucial component in vehicle fuel systems which plays a vital role in managing fuel vapour and maintaining the pressure inside the fuel tank within safe and regulated limits, contributing to both emissions control and vehicle safety. In vehicles, fuel tanks are closed and pressurized systems. As fuel evaporates, it creates pressure inside the tank. Maintaining this pressure is important to minimize emissions and prevent fuel leakage. The fuel tank isolation valve helps to control the pressure inside the tank by managing fuel tank venting.

[0006] The fuel tank isolation valve is installed between the fuel tank and a canister as part of the evaporative emission control system. It automatically opens when the pressure inside the tank exceeds certain limits, allowing excess vapour to flow to the canister for containment until it can be processed by the engine. If there's a negative pressure or vacuum generated inside the tank, such as during falling temperatures overnight, the fuel tank isolation valve opens automatically to maintain the pressure within a protected range. This prevents the tank from collapsing and allows air to flow from the canister into the tank. During refuelling, the fuel tank isolation valve is electrically actuated to allow fuel vapour to flow from the tank to the canister, preventing the escape of fuel vapour into the atmosphere.

[0007] US11913566 discloses a fuel tank isolation valve of a vehicle comprising: a first armature pulled toward an inside of a core by an electromagnetic force generated when a current is supplied to a coil; a second armature connected to the first armature thus operating in a same direction as the first armature, and configured to open and close a flow path, wherein the first armature and the second armature are connected so that there is no clearance in an axial direction; and a guide and a first spring provided between the first armature and the second armature to form an armature assembly; wherein the first spring is compressed by being supported at both ends thereof by the guide and the second armature, and a spring compression amount securing groove is formed on an upper surface of the guide; and wherein the armature assembly is in such a manner that, before assembled inside the fuel tank isolation valve, an under surface of a body of the first armature is in contact with a floor surface of the spring compression amount securing groove, and, when assembled inside the fuel tank isolation valve, the guide further compresses the first spring by moving toward the second armature while being in contact with the core.

[0008] CN1 10848430 discloses an oil tank isolating valve, includes isolating valve shell, solenoid valve, upper cover, lower cover, spring, diaphragm, its characterized in that: the left end and the right end of the isolation valve shell are respectively provided with a connecting pipe, and the upper end of the isolation valve shell is connected with a plurality of umbrella-shaped valves, a diaphragm is arranged above the isolation valve shell, and the upper part of the diaphragm is connected with the upper cover through a spring, the lower part of the isolation valve shell is connected with a lower cover through an overpressure / negative pressure safety valve module; one end of an electromagnetic valve is embedded at one side of the isolation valve shell, and the other end of the electromagnetic valve is connected with an electromagnetic valve cover .

[0009] The drawbacks related to these conventional fuel tank isolation valve are that these conventional fuel tank isolation valve does not provide proper over vacuum relief sealing and uses excessive number of parts that leads to higher chances of failure, lengthy assembling procedures which increases costs for both production and maintenance. Therefore, there is need for a fuel tank isolation valve with an improved over vacuum relief sealing that ensures proper sealing and improves the over vacuum functionality of the fuel tank isolation valve with the lesser number of parts which decreases the chances of failure, shortened assembling procedures which decreases costs for both production and maintenance.

[0010] OBJECT OF THE INVENTION

[0011] The main object of the present invention is to provide a fuel tank isolation valve with an improved over vacuum relief sealing that ensures proper sealing.

[0012] Another object of the present invention is to provide a fuel tank isolation valve with an improved over vacuum relief sealing that improves the over vacuum functionality of the fuel tank isolation valve with lesser number of parts.

[0013] Yet another object of the present invention is to provide a fuel tank isolation valve with an improved over vacuum relief sealing in which a seal holder has a taper shaft that helps in smoother movement of said flow limiter on the taper shaft reducing the friction and improves the performance of the fuel tank isolation valve in terms of flow and hysteresis.

[0014] Yet another object of the present invention is to provide a fuel tank isolation valve with an improved over vacuum relief sealing in seal which is snap fitted in a seal holder and increases the ease of manufacturability for the seal assembly.

[0015] Still another object of the present invention is to provide a fuel tank isolation valve with an improved over vacuum relief sealing in which the vacuum spring applies a uniform load around the sealing surface thus providing proper sealing and improving the performance of the fuel tank isolation valve.

[0016] SUMMARY OF THE INVENTION

[0017] The invention relates to a fuel tank isolation valve with an improved over vacuum relief sealing that ensure proper sealing and improves the over vacuum functionality of the fuel tank isolation valve with the lesser number of parts which decreases the chances of failure, shortened assembling procedures which decreases costs for both production and maintenance.

[0018] In an embodiment of present invention, a fuel tank isolation valve with an improved over vacuum relief sealing comprises a housing sub-assembly, a main housing, a cover, a pressure spring, a stroke limiter, a flow limiter and a moving core. The fuel tank isolation valve includes a seal that is secured onto a seal holder and the seal holder is placed around a seal holder shaft and seals the sealing surface of said seal with a lower surface of said flow limiter and limits a maximum flow from said fuel tank isolation valve. The seal holder shaft is assembled into a guiding cavity of said flow limiter configured to control the linear movement of said flow limiter. The moving core has a shaft and said shaft is coupled to said seal holder for connecting said seal holder and said moving core. The vacuum spring is placed below said seal holder and fitted around said moving core for an over-vacuum relief function. The noise damper is coupled to said moving core and said noise damper is provided to reduce the operational noise during solenoid actuation.

[0019] BRIEF DESCRIPTION OF THE DRAWING

[0020] An understanding of a fuel tank isolation valve with an improved over vacuum relief sealing of the present invention may be obtained by reference to the following figures:

[0021] Figure 1 is an exploded view of a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention;

[0022] Figure 2 is a cross-sectional view of a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention;

[0023] Figure 3 is a cross-sectional view of a seal and seal holder of a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention; Figure 4 is a perspective view of a seal, a seal holder and a moving core of a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention;

[0024] Figure 5 is a cross-sectional view of a vacuum spring and a moving core of a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention;

[0025] Figure 6 is a cross-sectional view of the stroke limiter in the fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention;

[0026] Figure 7(a) is a cross-sectional view of the fuel tank isolation valve with an improved over vacuum relief sealing in a pressure condition (i.e. over-pressure relief (OPR) function), according to an embodiment of the present invention; and

[0027] Figure 7(b), is a cross-sectional view of the fuel tank isolation valve with an improved over vacuum relief sealing in a vacuum condition (i.e. over-vacuum relief (OVR) function), according to an embodiment of the present invention.

[0028] DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention will now be described hereinafter with reference to the accompanying drawings in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough, and will fully convey the scope of the invention to those skilled in the art.

[0030] The present invention now will be described hereinafter with reference to the description, in which some, but not all embodiments of the invention are indicated. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. The present invention is described fully herein with non-limiting embodiments and exemplary experimentation.

[0031] Referring to Figure 1, an exploded view of a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention is depicted. The fuel tank isolation valve (1) with an improved over vacuum relief sealing comprises a housing sub-assembly (20), a main housing (2), a cover (6), a pressure spring (3), a stroke limiter (4), a flow limiter (5); and a moving core (11).

[0032] The main housing (2) includes the pressure spring (3) for the over pressure relief function and the pressure spring (3) is fixed over the flow limiter (5). The main housing (2) is provided with a mounting holes (16, 17) and a nozzle (18) is connected to tank and a nozzle (19) is connected to canister of the vehicle, and said main housing (2) is mounted over a housing sub-assembly (20).

[0033] The flow limiter (5) is placed under said stroke limiter (4). The pressure spring (3), said stroke limiter (4), and said flow limiter (5) is accommodated in said main housing (2).

[0034] The cover (6) is secured above said main housing (2) to close said fuel tank isolation valve (1) and maintains the installation height of said pressure spring (3) for the overpressure relief function.

[0035] The fuel tank isolation valve (1) include a seal (9) that is secured onto a seal holder (7) and the seal holder (7) is placed around a seal holder shaft (8) and seals the sealing surface of said seal (9) with a lower surface of said flow limiter (5) and limits a maximum flow from said fuel tank isolation valve (1). The seal (9) is secured onto said seal holder (7) by a snap-fit mechanism that simplifies the manufacturing process and reduces production complexity.

[0036] The seal holder shaft (8) is assembled into a guiding cavity (10) of said flow limiter (5) configured to control the linear movement of said flow limiter (5). The seal holder shaft (8) is of taper shaper and facilitates smoother movement into said guiding cavity (10) of said flow limiter (5) and reduces friction and improves performance of said fuel tank isolation valve (1).

[0037] The moving core (11) has a shaft (12) and said shaft ( 12) is coupled to said seal holder (7) for connecting said seal holder (7) and said moving core (11). The shaft (12) of said moving core (11) is coupled to said seal holder (7) through a ball and socket joint (13) mechanism.

[0038] The vacuum spring (14) is placed below said seal holder (7) and fitted around said moving core (11) for an over- vacuum relief function. The vacuum spring (14) is placed below said seal holder (7) applies a uniform load around said seal holder (7) for the proper sealing of the sealing surface of said seal (9) with the lower surface of said flow limiter (5) and improves the operational efficiency of said valve (1).

[0039] The noise damper (15) is coupled to said moving core (11) and said noise damper (15) is provided to reduce the operational noise during solenoid actuation.

[0040] Referring to Figure 2, a cross-sectional view of a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention is depicted. A fuel tank isolation valve (1) comprising a main housing (2) which includes a pressure spring (3) for over pressure relief function and the pressure spring (3) is fixed over a flow limiter (5) which perform over-pressure relief function, a flow limiter (5) is placed under said stroke limiter (4). The pressure spring (3), said stroke limiter (4), and said flow limiter (5) is accommodated in said main housing (2) to control the maximum flow by controlling operating strokes of said flow limiter (4) and a cover (6) is secured above said main housing (2) to close the valve and maintains the installation height of the pressure spring (3) for over- pressure relief function.

[0041] Further, the main housing (2) comprises a seal holder (7) with a taper shaft (8). A seal (9) is snap fitted on said seal holder (7) placed around said taper shaft (8) and said taper shaft (8) is inserted into a guiding cavity (10) of said flow limiter (5). The moving core (11) has a shaft (12) and said shaft (12) coupled to said seal holder (7) through a ball and socket joint (13) connecting said seal holder (7) and said moving core (11). A vacuum spring ( 14) is placed below said seal holder (7) and fitted around said moving core (11) for over-vacuum relief (OVR) function. A noise damper (15) is coupled to said moving core (11) provided to reduce the operational noise during solenoid actuation.

[0042] The main housing (2) provided with mounting holes (16, 17) and nozzle (18) is connected to tank and nozzle (19) is connected to canister of the vehicle and said main housing (2) is mounted over housing sub-assembly (20).

[0043] Referring to Figure 3, a cross-sectional view of a seal and seal holder a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention is depicted. The main housing (2) comprises a seal holder (7) with a taper shaft (8). A seal (9) is snap fitted on said seal holder (7) placed around said taper shaft (8). The seal (9) is snap fitted in said seal holder (7) which increases the ease of manufacturability for the seal assembly and decreases manufacturing complexity.

[0044] Referring to Figure 4, a perspective view of a seal, a seal holder and a moving core of a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention is depicted. A seal holder (7) has a taper shaft (8). A seal (9) is snap fitted on said seal holder (7) placed around said taper shaft (8). The moving core (11) has a shaft (12) and said shaft (12) coupled to said seal holder (7) through a ball and socket joint (13) connecting said seal holder (7) and said moving core (11).

[0045] Referring to Figure 5, a cross-sectional view of a vacuum spring and a moving core of a fuel tank isolation valve with an improved over vacuum relief sealing, according to an embodiment of the present invention is depicted. A seal (9) is snap fitted on said seal holder (7) placed around said taper shaft (8) and said taper shaft (8) is inserted into a guiding cavity (10) of said flow limiter (5). The moving core (11) has a shaft (12) and said shaft (12) coupled to said seal holder (7) through a ball and socket joint (13) connecting said seal holder (7) and said moving core (11). The vacuum spring (14) is placed below said seal holder (7) and fitted around said moving core (11) for over- vacuum relief function. The noise damper (15) is coupled to said moving core (11) provided to reduce the operational noise during solenoid actuation. The vacuum spring (14) applies the uniform load around the sealing surface thus providing the proper sealing, improving the performance of the fuel tank isolation valve.

[0046] Therefore, the present invention relates to a fuel tank isolation valve with an improved over vacuum relief sealing that ensure the proper sealing and improves the over vacuum functionality of the fuel tank isolation valve with the lesser number of parts which decreases the chances of failure, shortened assembling procedures which decreases costs for both production and maintenance.

[0047] EXAMPLE 1

[0048] Preferred Implementation of the fuel tank isolation valve with improved over vacuum relief sealing

[0049] The present invention provides a fuel tank isolation valve (1) with improved over vacuum relief sealing in which the arrangement of seal (9), the seal holder shaft (8), the seal holder (7) over the moving core (11). The moving core (11) includes the shaft (12) and a ball and socket joint (13) which is fitted with said seal holder (7). The structure of the moving core (11) easily adjust itself as per load application by the spring for maintaining the sealing, which also increase flexibility, that ultimately helps in better sealing of the product, thereby increasing the performance of the fuel tank isolation valve (1) with improved over vacuum relief sealing.

[0050] Further, in the fuel tank isolation valve (1), during pressure, the force exerted by vapour is from a bottom of the sealing surface for keeping the pressure inside by applying force in a downward direction which improves the performance as depicted in Figure 7(a).

[0051] Also, during vacuum, the force exerted by the vapour is from top of the seal and the sealing surface works against the vacuum force and seal the area by making more compression, as depicted in Figure 7(b). Further, the fuel tank isolation valve (1) with improved over vacuum relief sealing also include a stroke limiter (4) for limiting a maximum flow from the fuel tank isolation valve (1). Also, the stroke limiter (4) avoid caulking of the other inline valves during to high flow. In the maximum flow condition, flow limiter (5) touch the stroke limiter & flow then only pass through one or more holes in the flow limiter (5), as depicted in Figure 6.

[0052] Therefore the present invention provides fuel tank isolation valve with an improved over vacuum relief sealing that ensure the proper sealing and improves the over vacuum functionality of the fuel tank isolation valve.

[0053] Many modifications and other embodiments of the invention set forth herein will readily occur to one skilled in the art to which the invention pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0054] The foregoing description of embodiments of the invention has 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 principals 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

CLAIMSWe claim:

1. A fuel tank isolation valve (1) with improved over vacuum relief sealing comprising: a housing sub-assembly (20); a main housing (2); a cover (6); a pressure spring (3); a stroke limiter (4); a flow limiter (5); and a moving core (ii); wherein: said fuel tank isolation valve (1) includes a seal (9) that is secured onto a seal holder (7) and the seal holder (7) is placed around a seal holder shaft (8) and seals the sealing surface of said seal (9) with a lower surface of said flow limiter (5) and limits a maximum flow from said fuel tank isolation valve (1); said seal holder shaft (8) is assembled into a guiding cavity (10) of said flow limiter (5) is configured to control the linear movement of said flow limiter (5); said moving core (11) has a shaft (12) and said shaft (12) is coupled to said seal holder (7) for connecting said seal holder (7) and said moving core (11); a vacuum spring (14) is placed below said seal holder (7) and fitted around said moving core (11) for an over-vacuum relief function; and said noise damper (15) is coupled to said moving core (11) and said noise damper (15) is provided to reduce the operational noise during solenoid actuation.

2. The fuel tank isolation valve (1) with improved over vacuum relief sealing as claimed in claim 1, wherein said main housing (2) includes the pressure spring (3) for the over pressure relief function and the pressure spring (3) is fixed over the flow limiter (5).

3. The fuel tank isolation valve (1) with improved over vacuum relief sealing as claimed in claim 1, wherein said flow limiter (5) is placed under said stroke limiter (4).

4. The fuel tank isolation valve (1) with improved over vacuum relief sealing as claimed in claim 1, wherein said pressure spring (3), said stroke limiter (4), and said flow limiter (5) is accommodated in said main housing (2).

5. The fuel tank isolation valve (1) with improved over vacuum relief sealing as claimed in claim 1 , wherein said cover (6) is secured above said main housing (2) to close said fuel tank isolation valve (1) and maintains the installation height of said pressure spring (3) for the over- pressure relief function.

6. The fuel tank isolation valve (1) with improved over vacuum relief sealing as claimed in claim 1, wherein said main housing (2) is provided with a pair of mounting holes (16, 17) and a nozzle (18) is connected to a tank and a nozzle (19) is connected to a canister of the vehicle, and said main housing (2) is mounted over a housing sub-assembly (20).

7. The fuel tank isolation valve (1) with improved over vacuum relief sealing as claimed in claim 1, wherein said seal (9) is secured onto said seal holder (7) by a snap-fit mechanism that reduces production complexity.

8. The fuel tank isolation valve (1) with improved over vacuum relief sealing as claimed in claim 1 , wherein said shaft ( 12) of said moving core ( 11) is coupled to said seal holder (7) through a ball and socket joint (13).

9. The fuel tank isolation valve (1) with improved over vacuum relief sealing as claimed in claim 1, wherein said seal holder shaft (8) is of taper shape andfacilitates smoother movement into said guiding cavity (10) of said flow limiter (5) and reduces friction and improves performance of said fuel tank isolation valve (1).

10. The fuel tank isolation valve (1) with improved over vacuum relief sealing as claimed in claim 1, wherein said vacuum spring (14) is placed below said seal holder (7) and applies a uniform load around said seal holder (7) for the proper sealing of the sealing surface of said seal (9) with the lower surface of said flow limiter (5) and improves the operational efficiency of said valve (1).

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