Field

[001] This application relates to fuel tank valves. More specifically, the application provides a roll-over, liquid vapor discriminator, or other valve with membrane venting for fuel vapors.

Background

[002] A fuel tank can experience high pressure if fuel expands or vaporizes and no venting is provided. It is possible to mechanically vent vapors, but additional measures must be taken to exclude liquid fuel from the vapor line.

SUMMARY

[003] The methods and apparatus disclosed herein overcome the above disadvantages and improves the art by way of a compact assembly for venting fuel vapor. Methods and apparatus comprise use and support for an oleophobic membrane to discriminate between liquid fuel and fuel vapors.

[004] A valve housing comprises an upper surface, a lower surface, an opening for venting between the lower surface and the upper surface, a trench in the lower surface, a vacuum port in fluid communication with the trench, and ribs extending away from the lower surface.

[005] A method for affixing a membrane to the valve housing comprises abutting a membrane against the trench, applying a vacuum to the vacuum port, and sealing the membrane to the valve housing

[006] Another valve housing comprises a top panel comprising an inner surface, an outer surface, a first side, a second side, a third side, and a fourth side. A bottom panel comprises an inner surface, an outer surface, a first side, a second side, a third side, and a fourth side. A first solid rail and a second solid rail extend between the top panel and the bottom panel, wherein the first solid rail and the second solid rail extend between the inner surface of the top panel and the inner surface of the bottom panel, wherein the first solid rail is parallel to and adjacent to the first side of the top panel, and wherein the second solid rail is parallel to and adjacent to the second side of the top panel. A nozzle is connected to the first solid rail. A vapor housing is connected to the first solid rail, the vapor housing comprising a vapor input, the vapor input fluidly communicating with the nozzle. Ribs extend between the top panel and the bottom panel, the ribs comprise a wide set of slotted rails and a narrow set of slotted rails, wherein the ribs are in between and parallel to the first rail and to the second rail, and wherein the wide rails alternate with the narrow rails to form a sinusoidal pattern.

[007] Another method for affixing a membrane to a valve housing is performed on a valve housing comprising a top panel, a bottom panel, a first solid rail and a second solid rail extending between the top panel and the bottom panel. A nozzle is connected to the first solid rail, a vapor housing in fluid communication with the nozzle and connected to the first solid rail. Ribs extend between the top panel and the bottom panel, the ribs being spaced between the first solid rail and the second solid rail. The method comprises abutting a membrane against an inner surface of the top panel and an inner surface of the bottom panel. The membrane is abutted against the first solid rail and the second solid rail. And, the membrane is sealed to the first solid rail and to the second solid rail.

[008] Additional objects and advantages will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. The objects and advantages will also be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

[009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the claimed invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[010] FIGURE 1 is a first perspective view of a first embodiment of a valve housing.

[01 1] FIGURE 2 is a second perspective view of a second embodiment of a valve housing.

[012] FIGURE 3 is a side view of the valve housing.

[013] FIGURE 4 is a bottom view of the valve housing.

[014] FIGURE 5 is a top view of the valve housing.

[015] FIGURE 6 is a third perspective view of the valve housing with a membrane shown in broken lines. [016] FIGURE 7 is a perspective view of a third embodiment of a valve housing with a membrane shown in broken lines.

[017] FIGURE 8 is a side view of the valve housing of Figure 7.

[018] FIGURE 9 is a back view of the valve housing of Figure 7.

[019] FIGURE 10 is a front view of the valve housing of Figure 7.

[020] FIGURE 1 1 is a top view of the valve housing of Figure 7.

[021] FIGURE 12 is a perspective view of the third embodiment of a valve housing.

[022] FIGURE 13 is a cross section view of the valve housing of Figure 7.

[023] FIGURE 14A is a cross section view of a fourth embodiment of a valve housing.

[024] FIGURE 14B is a side view of the fourth embodiment of a valve housing.

[025] FIGURE 15 is a side view of a fifth embodiment of a valve housing.

[026] FIGURE 16 a flow diagram for a method of applying a membrane to the valve housing to form a valve.

[027] FIGURE 17 is a flow diagram for another method of applying a membrane to the valve housing to form a valve.

DETAILED DESCRIPTION

[028] Reference will now be made in detail to the examples which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Directional references such as "left" and "right" are for ease of reference to the figures and are not meant to limit the orientation of the disclosed valve housings.

[029] The methods disclosed herein overcome disadvantages and improve the art by way of a compact assembly for venting fuel vapor. Methods and apparatus comprise use and support for an oleophobic membrane to discriminate between liquid fuel and fuel vapors. Other membrane compositions can be used in the alternative, though for this example, the membrane is one suitable for discriminating between diesel UREA fluid dopant and fuel vapors.

[030] A roll-over valve prevents liquid fuel from entering a vapor vent line when a vehicle roll-over event occurs, or when fuel sloshing otherwise causes liquid fuel to contact the area near a vapor vent. Vapor venting is important to release pressure in the fuel tank and to comply with environmental regulations for filtering fuel vapors. The valve housing with membrane is substitutable for a mechanical roll-over valve, where a mechanism, such as a float, restricts the vapor opening if a fluid level raises the float. This is beneficial because vapor can vent regardless of fluid level.

[031] A valve housing 1000 can comprise an upper surface 1500, a lower surface 1600, an opening 1630 for venting between the lower surface and the upper surface, a trench 1640 in the lower surface, a vacuum port 1 1 10 in fluid

communication with the trench 1640, and ribs extending away from the lower surface. The valve housing can be integrally formed by, for example, injection molding or extrusion molding, so that the ribs are one-piece with the rest of the valve. In the alternative, the ribs can be welded or affixed to the valve housing. The valve housing is formed of high density polyethylene or like moldable material.

[032] The ribs comprise at least two outer planar structures 1610 with an outer edge 1612. The outer edge is formed with a step 1613, or indentation. The step 1613 on the outer edge forms a stop for an abutting membrane 1620 and the outer edge guides the membrane. The abutting membrane can be sealed to the ribs by, for example, heat staking. The planar structures 1610 in one alternative in Figure 2 is in the form a "W" shape along each respective outer edge, and in another alternative, in Figure 1 , the planar structures 161 1 form a "U" or "V"-like shape along each respective outer edge.

[033] The ribs comprise at least two inner planar structures 1614, 1615 on either side of the opening 1630 for the vent. The inner planar structures are slotted to facilitate vapor communication with the opening. That is, the inner planer structures have spacing between halves of the structure. Additional slotting can be used to increase vapor permeability. The shape of the inner planar structures follows the shape of the outer two planar structures 1610 or 161 1 . The membrane is supported by the inner planar structures, but it is not mandatory to heat stake the membrane to the inner planar structures.

[034] The valve housing has a solid body with an upper surface 1500 and a lower surface 1600. The upper surface can comprise a valve stem 1510 in fluid

communication with the opening 1630. The valve stem 1510 can connect to a vapor treatment system, such as a canister filter, another valve, or an exhaust gas recirculation system. The solid body can alternatively be cylindrical or circular, but the figures depict a rectilinear shape. When implementing a circular or cylindrical valve housing, the illustrated squared edges can become secants of a circle. To facilitate vapor flow, a cap 1520 provides vapor space and a connection to a tubular line 1530. Other valve stems, such as quick snap, O-ring, and gland type are contemplated in addition to the press-on (barbed) valve stem shown. It is also possible to reconfigure the upper surface of the solid body to re-route the vent line connection such that the valve stem extends at other angles, such as perpendicular to the plane of the upper surface 1500, or parallel or perpendicular to the ribs.

[035] The solid body comprises a first side 1 100, a second side, a third side, and a fourth side. A first trench 1640 is parallel to the first side 1 100. A first of the at least two planar structures is adjacent to and parallel to the second side 1200. A second of the at least two planar structures is adjacent to and parallel to the third side 1300. A second, alternative trench 1641 is formed opposite the first side parallel to the fourth side 1400.

[036] A membrane 1620 is affixed to the lower surface, the membrane extending along the ribs. A stop 1650 is shown adjacent to and parallel to the trench 1640. To form a vapor-permeable liquid shield, a method in Figure 16 of forming a valve can comprise step 1 abutting the membrane 1620 against the stop 1650, step 2 abutting the membrane against the outer edges 1612 of the at least two outer planar structures, step 3 applying a vacuum to the vacuum port 1210 or 1 1 10 and holding the membrane 1620 against the trench 1640 using the vacuum. The method can further comprise step 5 heat staking the membrane to the outer edges 1612, heat staking the membrane to the step 1613, or heat staking the membrane to both. Step 4 comprises heat staking the membrane to a land 1602 adjacent to and parallel to the trench 1640. In step 6, the heat staking is also done to a second land 1604 adjacent the fourth side. The heat staking, or other sealing method such as gluing or clamping, creates a liquid-tight seal between the membrane and the lower surface so that only vapors may pass to the opening 1630 for venting through the valve stem 1510. While the heat staking is shown in serial separate steps 4, 5, 6, the heat staking may be done simultaneously via a heat staking device that conforms to the rib and land shapes of the valve housing.

[037] The lower side 1600 can comprise a second trench 1641 . The second trench is in fluid communication with a second vacuum port 121 1 . The second trench is parallel to the second land 1604 and a second stop 1651 . The second vacuum port 121 1 can be used simultaneously with the first vacuum port 1210 to secure two ends of the membrane in place. When two vacuum trenches and two stops are used, the method of Figure 16 can alternatively include step 7, to abut the membrane against the second stop, and step 8, applying a vacuum to the second vacuum port to hold the membrane against the second trench. A vacuum can be applied serially to the first and then to the second vacuum port, or as illustrated with simultaneous vacuum to each vacuum port.

[038] A method for securing the membrane alternatively includes blocking the valve stem via a stopper or like sealing member to enable a vacuum to hold the membrane 1620 against the ribs.

[039] While the vacuum port 1 1 10 is shown perpendicular to the trench in Figure 2, the vacuum port 1210, 121 1 can alternatively be formed in one or both of the second or third side so that the vacuum port is parallel to the first or second trench, as shown in Figure 1 . The vacuum port can include a frit, step, protrusion, or O-ring to provide a seal with a vacuum supply. Alternatively, the vacuum supply can sealingly engage with the vacuum port through mechanisms attached to the supply.

[040] A method for affixing a membrane to a valve housing can comprise abutting a first end of a membrane against a trench, applying a vacuum to the trench via a vacuum port, and sealing the membrane to the valve housing by heat staking the membrane to a land adjacent to the trench.

[041] The method further comprises extending the membrane around the ribs, abutting the membrane edges against an outer edge 1612 and a step 1613 of the at least two outer planar structures, and heat staking the membrane to the outer ribs and another land.

[042] When the valve housing further comprises a stop adjacent to and parallel to the trench, the method further comprises abutting the first end of the membrane against the stop.

[043] At least two of the ribs comprise an outer edge 1612 and a step 1613 along the perimeter of the at least two ribs. The method then further comprises abutting the membrane in each of the respective outer edges, and sealing the membrane against the respective outer edges, against the steps, or both. [044] When the valve housing further comprises a second trench and a second vacuum port, the method further comprises step 7, abutting the membrane against the second trench, step 8, applying a vacuum to the second vacuum port, and step 6, heat staking the membrane to the second land.

[045] Alternatively, the valve can be configured as shown in figures 7-13. The valve is comprised of a top panel 1700 with an outer surface 1710 and an inner surface 1720, an opening 1730 between the top panel outer surface and inner surface for accepting a ball valve 1722. A bottom panel 1800 has an outer surface 1810 and an inner surface 1820. A ball valve 1722 is attached to the inner surface of the top panel. A valve stem 1728 is attached to vent vapor from the vapor housing 1723. Ribs extend between the inner surface of the top panel and the inner surface of the bottom panel. The vapor housing can be integrally formed by, for example, injection molding or extrusion molding, so that the ribs are one-piece with the vapor housing 1723 and valve stem 1728. In the alternative, the ribs can be welded or affixed to the valve housing. The valve housing is formed of high density polyethylene or like moldable material. The ball valve 1722 is installed in the opening 1730, and the cap 1721 seats in the opening 1730.

[046] The top panel comprises a first side 1740, a second side 1750, a third side 1760, and a fourth side 1770. The bottom panel comprises a first side 1840, a second side 1850, a third side 1860, and a fourth side 1870. A solid rail 1742 extends between the inner surface of the top panel and the inner surface of the bottom panel parallel and adjacent to the first side of both the top and bottom panels. A second solid rail 1752, extends between the inner surface of the top panel and the inner surface of the bottom panel parallel and adjacent to the second side of both the top and bottom panels.

[047] The ball valve comprises a vapor housing 1723, a ball 1724, a valve cap 1721 , a valve seat 1729, an input 1726 for vapor flow through the valve when the ball 1724 is unseated and in an open position, and an output 1727 through the affixed valve stem. The vapor housing 1723 is attached on the inner surface of the top panel along the first side, with the valve stem extending from the output of the ball valve. The housing can be offset or in another location. And, the surfaces of the vapor housing 1723 can be other shapes to accommodate mounting requirements, such as by having a circular top surface 1710. [048] When pressure inside the valve becomes high enough, the ball is forced away from the valve seat 1729 and against the center post 1725 of the valve cap 1721 , allowing for vapor to flow into the input 1727, through the vapor housing, and be output through the attached valve stem 1728 to an exhaust or vapor collection system. While the valve seat 1729 is shown planar in Figure 12, as suggested in Figure 8, the valve seat 1729 can be conical to guide ball 1724 downward in vapor housing 1723 to reseat. While ball valve 1722 is shown as a gravity type, other spring or diaphragm valves may also be used in vapor housing 1723.

[049] The cap 1721 is two pieces, as shown, or integrally formed of a one piece material. Steps 1731 in the opening align with the ridges 1732 in the valve cap to form a barrier to prevent vapor from escaping through opening 1730. Additional seals can be included to reduce unwanted vapor escape, such as o-ring and glands, or press-fit materials. Heat sealing or UV curing is also possible to mate the cap and housing sealingly together.

[050] The ribs comprise a series of wide slotted rails 1900 with an outer edge 1902 alternating with a series of narrow slotted rails 1910 with an outer edge 1912. The rails extend between the inner surface 1720 of the top panel and the inner surface 1820 of the bottom panel parallel to the first side 1740, 1840 of the top and bottom panels. Some rails interface with the vapor housing 1723 and are thus co- molded. The rails comprise slots 1904, 1914 to facilitate vapor flow through the valve. Additional slots can be formed in the rails, such as through the rails and parallel to the center posts, to further permit vapor flow. The outer edges 1902 of the wide slotted rails extend to a distance near but not equal to the third and fourth sides of the top and bottom panels. The outer edges of the narrow slotted rails 1912 extend to a distance recessed from the outer edges of the wide slotted rails so that the alternating pattern along the outer edges of the set of wide and narrow slotted rails forms a sinusoidal pattern in respect to the top and bottom panels.

[051] A membrane 1950 is affixed to the solid rails 1742 and 1752, the

membrane extending along exterior edges of the ribs 1960. Risers 1960 project from the inner surface of the top panel 1720 and from the inner surface of the bottom panel 1820 and form a sinusoidal step. The risers 1960 include an inner surface 1962 forming a wedge of material. Membrane 1950 abuts the risers along the sinusoidal pattern and is supported against the wide and narrow slotted rails. Vapor can circulate in the slots 1904, 1914 to reach vapor input 1726.

[052] To form a vapor-permeable liquid shield, as shown in Figure 17, a method of forming a valve comprises step 9 extending the membrane across a first series of ribs, step 10 abutting the membrane against the inner surfaces of the top and bottom panels. The method can further comprise step 1 1 heat staking the

membrane to the risers. In steps 12 and 13 the membrane is further heat staked to the first land 1743 of the first solid rail and to the first land 1753 of the second solid rail. The method further comprises step 14 abutting a second sheet of membrane across a second series of ribs, step 15 abutting the membrane against the inner surfaces of the top panel and bottom panel, step 16 heat staking the membrane to the risers, and, in steps 17 and 18, heat staking the membrane to the second land 1744 of the first solid rail and to the second land 1754 of the second solid rail. The heat staking, or other sealing method, creates a liquid-tight seal between the membrane and the ribs so that only vapors may pass to the vapor input 1726 for venting through the ball valve. While it is possible to drape the membrane along the risers 1960 and heat stake the membrane in place, it is also possible to affix the membrane to a heat stake device, and then conform the heat stake device to the outer shape of the valve housing and form a heat seal.

[053] Another embodiment is shown in Figures 14A and 14B. The sinusoidal wide and narrow rail patterns are used again, but in this implementation, the vapor housing 2023 extends through the valve housing to adjust the location of the ball 2024 in ball valve 2722. The valve stem 2028 is located closer to the bottom panel than to the top panel. As before, a vapor input 2026 communicates through the vapor housing 2023, and when vapor pressure suffices, the ball 2024 unseats from the valve seat 2029. A center post 2025 of the cap 2021 restricts the motion of the ball 2024. When the ball 2024 is unseated, fluid flow is permitted between the vapor input 1726 and the valve stem 2028. Valve seat 2029 can be planar, as shown in Figure 14A, or conical, as shown in Figure 14B.

[054] As shown in Figure 14B, a liquid level line 3000 is illustrated. Should liquid enter or condense in the interior of the valve housing, the liquid is released out the valve stem 2028. The liquid level inside the valve housing is thus maintained at a low level. Liquid entering the vapor input 2026 is directed to a liquid trap or other drain mechanism for return to the fuel tank.

[055] Because another system component could already include a ball valve, it is possible to use redundancy and include the ball valve arrangements of Figures 13, 14A and 14B, Or, it is possible to exclude the ball valve from the membrane valve and implement the valve of Figures 1 , 2, or 15 in the fuel system.

[056] Figure 15 includes features of Figures 7-14B, but modifications remove the ball valve, opening, cap and center post. The fifth embodiment includes top panel 4700, bottom panel 4800, barbed valve stem 4028, vapor input 4026, and a vapor housing 4023. A membrane is staked to the solid rails 4742 and 4752 and draped along the sinusoidal wide slotted rails 4900 and narrow slotted rails 4910 and the membrane is staked to the risers 4960. The vapor housing 4023 can be co-molded to the inner surface 4962 of the risers, but the illustration shows a gap between them.

[057] The vapor housing 4023 is a hollow, cylindrical body extending from the barbed nozzle 4028. The vapor housing 4023, if not cylindrical, is well-radiused, and is co-molded with the other structures and can be a tapered structure in some embodiments. Tooling forms at least one vapor input 4026 so that vapors fluidly communicate with the barbed nozzle to exit the valve housing. Should liquid collect in the valve housing, it can be drained out the nozzle and returned to the fuel tank via a fuel trap or other drain mechanism.

[058] The structures disclosed are beneficial when integrated with other fuel system components, such as charcoal canisters, overfill protection, over pressure relief valves, or over vacuum relief valves. Thus it is possible connect valve stem 1510, 1728, 2028, 4028 to the other fuel system components. In the alternative, it is possible to integrate the valve housing with valve assemblies so that the vapor vent opening 1630, 1730, 2730 vents directly into the body of the other fuel system components.

[059] Other implementations will be apparent to those skilled in the art from consideration of the specification and practice of the examples disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.