Double shut-off refueling valve

Abstract

Fuel fill limiting vent valve (102) for closing a first line (110) and a second line (108) in a fuel system (100), wherein the valve (102) comprises: a housing (120); a float (122) arranged in the housing (120), wherein the float (122) has a sealing device arranged on a top side; and a cover (126) attached to the housing (120), the cover (126) having: a first opening (132) corresponding to the first conduit (110), a second opening (136) corresponding to the second conduit (108), the first opening (132) and the second opening (136) being arranged concentrically; a first tube (138) projecting from a surface of the cover (126) and having the first opening (132), and a second tube (134) extending beyond the first tube (138) and having the second opening (136);and a first seal (142) surrounding the first opening (132), and a second seal (144) surrounding the second opening (136); wherein the float (122) is arranged such that the sealing device closes the first and the second opening (132, 136) essentially simultaneously.

Description

[0001] This application claims priority over the preliminary US application with file number 60 / 772772, filed on February 13, 2006, and the preliminary US application with file number 60 / 851159, filed on October 12, 2006, the descriptions of which are expressly incorporated herein by reference. TECHNICAL AREA

[0002] The present invention relates to shut-off valves for vehicle fuel systems and in particular to a valve which is configured to shut off more than one single vapor path in the fuel system. BACKGROUND TO THE INVENTION

[0003] Vehicle fuel systems include a mechanism that detects when the fuel level in the tank reaches full. The mechanism then locks or shuts off the fuel nozzle to prevent further fuel from entering the tank and to maintain the pressure in the tank at or below a desired level. Part of the mechanism includes a recirculation line that is either connected to a vent line between the fuel tank and a vapor storage tank via a T-fitting or connected directly into the fuel tank. When connected to the fuel tank, this recirculation line (also referred to as a "dip tube") is closed by the fluid or a liquid-operated valve when the fuel tank is full.The fuel system typically uses a reservoir to capture fuel vapor and prevent it from escaping into the atmosphere. The vapor flows through a pipe forming a reservoir line, which should also be sealed when the fuel reaches full level. Ideally, the recirculation line and the reservoir line are sealed simultaneously when the fuel tank is full to prevent liquid fuel from flowing between the two lines and to keep any liquid from entering any line. BRIEF DESCRIPTION OF THE INVENTION

[0004] To protect both the recirculation line and the tank line from liquid overflow, the invention is generally directed to a double shut-off refueling valve that responds to a full fuel tank level by simultaneously blocking the recirculation line and the tank line. The valve includes at least one float with one or more sealing surfaces corresponding to the recirculation line and the tank line, respectively. The sealing surface is located on the upper side of a float in the float valve. When the fuel in the tank reaches a full level, the float moves upwards to simultaneously close the recirculation line and the tank line.

[0005] In one embodiment, the valve is a float valve that has a concentric or coaxial seal when the two valve openings belonging to the dip tube and the vapor vent channel are arranged concentrically. In other embodiments, the sealing surfaces can, for example, be two separate sealing surfaces or have any other sealing configuration that corresponds to the orientation or arrangement of the dip tube and the vapor vent channel in the fuel system. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Fig. 1 shows a representative schematic representation of a fuel system that incorporates an inventive Includes double shut-off refueling valve;

[0007] Fig. 2 shows a representative schematic cross-sectional view of a double shut-off refueling valve in the system according to Fig. 1 according to an embodiment of the invention;

[0008] Fig. 3 shows a perspective view of a double shut-off refueling valve according to Fig. 2;

[0009] Fig. 4 shows a cross-sectional view of the valve according to Fig. 3, cut along line 4-4;

[0010] Fig. 5 shows a representative schematic cross-sectional view of a double shut-off refueling valve according to a further embodiment of the invention;

[0011] Fig. 6 shows a representative schematic cross-sectional view of a double shut-off refueling valve according to a further embodiment of the invention and

[0012] Fig. 7 shows a representative schematic cross-sectional view of a double shut-off refueling valve according to a further embodiment of the invention. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0013] Fig. 1 shows a representative schematic diagram of a fuel system 100, which is a fuel system according to the invention. The system 100 includes a fuel limit vent valve (FLVV) 102, which acts as a double shut-off refueling valve. The system 100 comprises a fuel tank 103 and a filler neck 104 with a seal 106 designed to seal around a fuel tap (not illustrated). A recirculation or return line 108 connects the tank 103 to the filler neck 104 to return fuel vapor from the tank 103, while a reservoir line 110 connects the tank 103 to a reservoir (not illustrated) that stores excess fuel vapor. The ends of the recirculation line 108 and the tank line 110 open into the tank 103, while the FLVV 102 is arranged to shut off both lines at the same time, preventing liquefied fuel from passing from one line to the other.Closing the FLVV 102 causes a vacuum to build up in the recirculation line 108, which triggers a shut-off of the fuel tap. This leads to an increase in the fuel vapor pressure in the tank 103, which, in the event of a leaking mechanical seal, or when used in conjunction with conventional fuel systems or an architecture with a mechanical seal, enables pressure-controlled shut-off of the fuel supply. The system 100 may also include a vent valve 112 connected to the tank line 110, although this valve 112 is not part of the invention.

[0014] Figures 1 to 5 show a configuration of a system 100 in which the recirculation line 108 and the reservoir line 110 are arranged concentrically to each other. Although the figures show that the reservoir line 110 is arranged outside the recirculation line 108, the recirculation line 108 can be arranged outside the reservoir line 110 and the FLVV 102 can be configured to shut off the lines 108 and 110 without deviating from the scope of the invention. It should be noted that the recirculation line 108 and the reservoir line 110 can also be arranged side by side (e.g., as illustrated in Figure 6) and the FLVV 102 can be configured to shut off these lines without deviating from the scope of the invention.

[0015] Figures 2 to 4 show an FLVV 102 according to an embodiment of the invention. In this embodiment, the FLVV 102 has a coaxial seal configuration. The FLVV 102 includes a cylindrical housing 120 that surrounds a float 122, which is pre-tensioned by an elastic element 124 (e.g., a spring). A cover 126 serves as an upper closure for the housing 120. In one embodiment, the housing 120 has several slots 128 that are connected to several tongues 130 formed around the cover 126. Other methods can also be used to attach the cover to the housing.

[0016] In this embodiment, the cover 126 has one or more first openings 132 surrounding a tube 134, which has a second opening 136, thus forming a coaxial arrangement. The first openings 132 are formed in a first ring 138, which rises from or projects from the upper surface of the cover. The first ring 138 includes a first groove 140, which holds a first seal 142, for example, an O-ring. The tube 134 extends beyond the first ring 138 and has a second seal 144, for example, an O-ring, surrounding the second opening 136. A collar 146 may be formed on the tube 134 to support the second seal 144. The interior of the FLVV 102 in this embodiment can have any known configuration of a float valve.

[0017] As illustrated in Fig. 2, the coaxial configuration of the first seal 142 and the second seal 144 corresponds to the concentric configuration of the recirculation line 108 and the container line 110. In this embodiment, the end of the recirculation line 108 is higher than the end of the container line 110. The pipe 134 on the FLVV 102 extends into the recirculation line 108, so that the first seal 142 seals against the inner wall of the recirculation line 108. The end of the recirculation line 108 can rest against the collar 146 when the FLVV 102 is correctly positioned. The second seal 144 seals against the inner wall of the container line 110, which concentrically surrounds the recirculation line 108. The end of the container pipe 110 can rest against the upper surface of the lid 126 if the FLVV 102 is correctly positioned.

[0018] When the fuel level in the fuel tank 103 is below full, the float 122 remains in the lower part of the housing 120, leaving the recirculation line 108 and the reservoir line 110 open. Fuel vapor is thus allowed to flow freely between the tank 103 and the recirculation line 108 and the reservoir line 110 through side openings 146 in the housing 120. When the fuel level in the tank 103 reaches full, liquid fuel flows into the housing 120 through the side openings 146, causing the float 122 to rise and open the first opening(s). The second opening 132, 136 in the cover 126 is closed, thereby shutting off the recirculation line 108 and the tank line 110 simultaneously. This double shut-off functionality allows for quick, simultaneous shut-off of both lines 108, 110, thus minimizing the pressure increase in the tank and the transfer of liquid fuel between the lines.

[0019] Fig. 5 illustrates an FLVV 102 according to a further embodiment of the invention. In this embodiment, the float 122 has a band valve 150 mounted on its upper side. The band valve 150 utilizes the elasticity of the band to seal both openings 132, 134 simultaneously without requiring additional parts or devices to create two separate sealing surfaces. Since the band is flexible and the sealing surfaces are rigid, in the preferred embodiment the sealing surface associated with the first (outer) opening 132 is somewhat longer (i.e., closer to the band / float) than the sealing surface associated with the second (central) opening 134. This ensures that the main liquid seal prevents fuel from escaping from the fuel tank into either of the two lines.

[0020] Figures 6 and 7 show embodiments of the invention in which the recirculation line 108 and the reservoir line 110 are arranged side by side instead of concentrically to each other. Figure 6 shows a FLVV 102, which has a tiltable sealing device 152 with two line seals 154 that are aligned with the recirculation line 108 and the reservoir line 110. The slight tilting action of the sealing device 152 compensates for any minor fluctuations in the positions of the lines 108 and 110, so that they can be securely closed simultaneously by the seals 154 when the float 122 rises. Figure 7 shows a configuration with two float valves 160, each containing a float 122 inside a housing 120. The float valves 160 are arranged in the tank 103 such that the floats 122 close their associated lines 108, 110 simultaneously. Although Fig.2. Two separate housings are shown, each of which accommodates a single float; the two floats can also be contained within a single housing.

[0021] By incorporating a valve arrangement that simultaneously blocks a recirculation line and a tank line, the fuel system according to the invention ensures rapid shut-off of the dispensing nozzle when the fuel in the tank reaches a predetermined fill level. The rapid closing process minimizes the increase in tank pressure, and the simultaneous closure of the two lines prevents fluid from flowing back between the lines.

[0022] A double shut-off refueling valve 102 responds to a full fuel tank level by closing the recirculation line 108 and the reservoir line 110. The valve includes at least one float (122) with one or more sealing surfaces 150 corresponding to the recirculation line and the reservoir line, respectively. The sealing surface is located on the top of the float in the float valve. When the fuel in the tank 100 reaches full level, the float moves upward to close the recirculation line and the reservoir line essentially simultaneously. In one embodiment, the valve is a float valve having a coaxial seal, wherein the two valve openings corresponding to the recirculation line and the reservoir line are concentric. are arranged. In other embodiments, the sealing surfaces can be, for example, a band seal, two separate sealing surfaces, or any seal of another configuration corresponding to the arrangement of the recirculation line and the reservoir line in the fuel system. Summary:

[0023] A double shut-off refueling valve (102) responds to a full fuel tank level by closing the recirculation line (108) and the reservoir line (110). The valve includes at least one float (122) with one or more sealing surfaces (150) corresponding to the recirculation line and the reservoir line, respectively. The sealing surface is located on the top of the float in the float valve. When the fuel in the tank (100) reaches full level, the float moves upward to close the recirculation line and the reservoir line essentially simultaneously. In one embodiment, the valve is a float valve having a coaxial seal, with the two valve openings corresponding to the recirculation line and the reservoir line being arranged concentrically.In other embodiments, the sealing surfaces may, for example, be a band seal, two separate sealing surfaces, or any seal of other configuration corresponding to the arrangement of the recirculation line and the reservoir line in the fuel system.

Claims

[1] Fuel fill limiting vent valve for closing off a first line and a second line in a fuel system, the valve comprising: a housing; a float disposed in the housing, the float having sealing means disposed on a top; anda cover attached to the housing, the cover comprising: a first opening corresponding to the first conduit, and a second opening corresponding to the second line, wherein the float is arranged such that the sealing means closes the first and second openings substantially simultaneously. [2] The valve of claim 1, wherein the first port and the second port are arranged concentrically. [3] The valve of claim 2, wherein the cap further comprises: a first tube protruding from a surface of the lid and having the first opening, and a second tube extending beyond the first tube and having the second opening. [4] The valve of claim 2, further comprising a first seal surrounding the first opening and a second seal surrounding the second opening. [5] The valve of claim 2, wherein the first port includes a plurality of first ports disposed around the second port. [6] The valve of claim 5, further comprising: a first tube protruding from a surface of the lid and having the plurality of first openings, a first seal surrounding the plurality of first openings, a second tube extending beyond the first tube and having the second opening, and a second seal surrounding the second opening. [7] The valve of claim 6, wherein the first ring has a groove that receives the first seal, while the second ring has a collar that supports the second seal. [8] The valve of claim 1, wherein the sealing means comprises a resilient band seal capable of sealing both the first and second ports. [9] The valve of claim 1, wherein the sealing means is a hinged seal having two conduit seals capable of sealing both the first and second ports. The valve of claim 1, wherein the float comprises two separate floats, each float comprising sealing means associated with one of the first conduit and the second conduit. [11] Vehicle fuel system comprising: a fuel tank; a filler neck connected to the fuel tank; a recirculation line connected between the filler neck and the fuel tank, the recirculation line opening into the tank via a first opening; a canister line connected to the fuel tank to conduct vapor to and from a canister; and a fuel fill limit vent valve positioned in the fuel tank, the valve comprising: a housing a float disposed within the housing, the float having sealing means disposed on a top, and a lid attached to the housing, the lid having a first opening corresponding to the recirculation line and a second opening corresponding to the reservoir line, wherein the float is arranged such that the sealing means closes the first and second openings substantially simultaneously when the level in the fuel tank reaches a predetermined level. The system of claim 11, wherein the recirculation line and the reservoir line are concentrically arranged, and wherein the first opening and the second opening in the cover of the valve are concentrically arranged to correspond to the recirculation line and the tank line. The system of claim 12, wherein the cap in the valve further includes a first tube protruding from a surface of the cap and having the first opening, and a second tube extending beyond the first tube and the second opening having. [14] The system of claim 11, wherein the valve further comprises a first seal surrounding the first opening and a second seal surrounding the second opening. [15] The system of claim 11, wherein the first opening includes a plurality of first openings arranged around the second opening. [16] The system of claim 15, wherein the cap in the valve further comprises: a first tube protruding from a surface of the lid and having the plurality of first openings, a first seal surrounding the plurality of first openings, a second tube extending beyond the first tube and having the second opening, and a second seal surrounding the second opening. The system of claim 16, wherein the first ring has a groove that holds the first seal, while the second ring has a collar that supports the second seal. The system of claim 11 wherein the recirculation line and the reservoir line are juxtaposed and the sealing means in the valve is one selected from the group consisting of a band seal and a hinged sealing means having two line seals. The system of claim 11, wherein the float comprises two separate floats, each float having sealing means corresponding to either the first conduit or the second conduit. [20] The system of claim 11, further comprising a mechanical nozzle seal disposed in the filler neck. [21] Vehicle fuel system comprising: a fuel tank; a filler neck connected to the fuel tank; a recirculation line connected between the filler neck and the fuel tank, the recirculation line opening into the tank via a first opening; a canister line positioned adjacent the recirculation line and connected to the fuel tank for conducting vapor to and from a canister; a first fuel fill limit vent valve positioned in the fuel tank to close the recirculation line and a second fuel fill limit vent valve positioned in the fuel tank to close the canister line, the first and second valves each comprising: a case, a float disposed in the interior space of the housing, the float having a surface disposed on a top surface Having sealing means, and a lid attached to the housing, the lid having an opening corresponding to either the recirculation line or the tank line, wherein the floats in the first and second valves are arranged such that the sealing means in the first and second valves close the first and second openings substantially simultaneously when a level in the fuel tank reaches a predetermined level.

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