Vent Valve Assembly

Abstract

A vent valve assembly for a fuel tank may include a housing having an outer wall structure and an inner wall structure, with a chamber formed between the outer wall structure and the inner wall structure, and a float disposed inside the chamber and movable along an axis relative to the housing. The float has an orifice extending along the axis. The inner wall structure of the housing is disposed within the orifice of the float. The inner surface of the orifice of the float is positioned to face the inner wall structure of the housing. The vent valve assembly also includes one or more guide mechanisms disposed on an inner surface of the orifice of the float, and one or more mating guide mechanisms disposed on the inner wall structure of the housing and configured to mate with the one or more guide mechanisms. The one or more guide mechanisms and the one or more mating guide mechanisms cooperate to guide relative movement of the float relative to the housing along the axis and to limit rotation of the float about the axis.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This disclosure claims priority to Indian Provisional Patent Application No. 202211054223, entitled "Features to improve sealing capability in CCV," filed on September 22, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates generally to fuel storage systems, and more particularly to a vent valve assembly for a vehicle fuel tank. [Background technology]

[0003] Vehicle fuel tanks often utilize safety systems to provide safe and consistent operation under a range of conditions. Typically, safety systems open communication between the fuel tank and other components of the fuel system to allow pressurized fuel vapor to escape from the fuel tank under normal conditions, and close communication between the fuel tank and other components of the fuel system to prevent liquid fuel from spilling from the fuel tank during liquid fuel overfill, for example, when the vehicle is placed on an incline, or when there is aggressive vehicle and / or fuel movement. Reliable performance of these safety systems is particularly critical in view of the high flammability and energy density of fuels. Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a vent valve assembly having various components that allow for the safe venting of fuel vapors while preventing the unintentional leakage of liquid fuel. Features are also disclosed that allow the system to function properly under a range of operating conditions, such as overfilling, vehicle position on an incline, and / or significant vehicle and fuel movement. Furthermore, in addition to providing vapor venting and liquid leakage prevention, the disclosed vent valve assembly can offer manufacturing benefits such as low production costs, efficient packaging, and a small system footprint. [Means for solving the problem]

[0005] In one embodiment, a vent valve assembly for a fuel tank includes a housing having an outer wall structure and an inner wall structure defining a chamber, and a float disposed inside the chamber and movable along an axis relative to the housing. The float may have an orifice extending along the axis. The inner wall structure of the housing may be disposed within the float's orifice. An inner surface of the float's orifice may be positioned to face the inner wall structure of the housing. The vent valve assembly may also include one or more guide mechanisms disposed on the inner surface of the float's orifice, and one or more mating guide mechanisms disposed on the inner wall structure of the housing and configured to mate with the one or more guide mechanisms. The one or more guide mechanisms and the one or more mating guide mechanisms may cooperate to guide the float's movement along the axis relative to the housing and limit the float's rotation about the axis.

[0006] Also, in one embodiment, the one or more guide mechanisms extend along the axis substantially the entire length of the float.

[0007] Also, in one embodiment, the length of the one or more guide features is substantially the same as the length of the one or more mating guide features.

[0008] In one embodiment, the one or more guide mechanisms are configured as guide channels. In one embodiment, the one or more mating guide mechanisms are configured as guide portions that are inserted into the guide channels.

[0009] Also, in one embodiment, the one or more guide features may be evenly distributed radially on the inner surface of the float.

[0010] Also, in one embodiment, the one or more mating guide features may be evenly distributed radially on the inner wall of the housing.

[0011] Additionally, in one embodiment, the one or more mating guide features include a knob.

[0012] Also, in one embodiment, four guide mechanisms and four mating guide mechanisms are provided.

[0013] In one embodiment, the vent valve assembly further includes one or more additional guide mechanisms disposed on the outer surface of the float, and one or more additional mating guide mechanisms disposed on the outer wall of the housing and configured to mate with the one or more additional guide mechanisms.

[0014] In one embodiment, the vent valve assembly includes a housing having an outer wall structure, an inner wall structure, and a valve orifice, wherein a chamber is formed between the outer wall structure and the inner wall structure. The vent valve assembly further includes a float disposed inside the chamber and movable axially relative to the housing, a flapper disposed on an upper surface of the float and aligned with the valve orifice, and a flapper guide disposed on the upper surface and configured to engage the flapper. The flapper guide allows the flapper to open and close and maintains the flapper aligned with the valve orifice.

[0015] Also, in one embodiment, the flapper guide is a hinge having two ends each connected to the top surface of the float.

[0016] Also, in one embodiment, the flapper guide is a hinge having one end connected to the top surface of the float and the other end not connected to the top surface of the float.

[0017] Also, in one embodiment, the flapper guide includes a channel.In one embodiment, the flapper includes one or more posts rotatably inserted into the channel of the flapper guide.

[0018] Additionally, in one embodiment, the flapper guide includes a stopper configured to limit the opening of the flapper.

[0019] Also, in one embodiment, the flapper guide is a rib.

[0020] In one embodiment, the flapper guide also includes a base having a large cross-sectional area to limit lateral movement of the flapper, hi one embodiment, the cross-sectional area of ​​the base is rectangular.

[0021] In one embodiment, the flapper also includes one or more connector ends. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a cross-sectional side view that schematically illustrates an exemplary embodiment of a Compact Combo Valve (CVV) assembly. [Figure 2] 1 shows an exploded side perspective view illustrating an exemplary embodiment of a Grade Vent Valve (GVV) including a housing, a flapper, and a float. [Figure 3] A cross-sectional side view of the GVV is shown. [Figure 4]1 shows a plan view and a side cross-sectional view of a GVV with certain components omitted for better viewing. [Figure 5] FIG. 1 shows an enlarged cross-sectional side view of a GVV with the float in the raised position. [Figure 6] FIG. 6 is an enlarged view of the GVV in FIG. 5, showing the flapper. [Figure 7] 1 illustrates an embodiment of a flapper in plan view. [Figure 8] 8 shows the flapper in FIG. 7, a side view. [Figure 9] 8 shows the flapper from FIG. 7 in an open position. [Figure 10] 10A and 10B are exemplary diagrams illustrating a flapper, a flapper guide, and an alignment member according to one embodiment. [Figure 11] 1 illustrates one embodiment of an alignment member according to the present disclosure. [Figure 12] 1 illustrates one embodiment of an alignment member according to the present disclosure. [Figure 13] 10 illustrates another embodiment of an alignment member according to the present disclosure. [Figure 14] 1 illustrates an alignment member on a float and housing according to the present disclosure. [Figure 15] 1 illustrates an alignment member on a float and housing according to the present disclosure. [Figure 16] 11 is a view showing the flapper and the flapper guide in FIG. 10 from another angle. FIG. [Figure 17] 1A and 1B illustrate an embodiment of a flapper and flapper guide according to the present disclosure. [Figure 18] 1A and 1B illustrate an embodiment of a flapper and flapper guide according to the present disclosure. [Figure 19] 10A and 10B are diagrams illustrating another embodiment of a flapper and a flapper guide according to the present disclosure. [Figure 20] 10A and 10B are diagrams illustrating another embodiment of a flapper and a flapper guide according to the present disclosure. [Figure 21] 10A and 10B are diagrams illustrating still another embodiment of a flapper and a flapper guide according to the present disclosure. [Figure 22] 10A and 10B are diagrams illustrating still another embodiment of a flapper and a flapper guide according to the present disclosure. [Figure 23] 23 is a diagram showing the flapper and the flapper guide in FIG. 21 and FIG. 22 from a different angle. [Figure 24] 23 is a diagram showing the flapper and the flapper guide in FIG. 21 and FIG. 22 from a different angle. [Figure 25] 23 is a diagram showing the flapper and the flapper guide in FIG. 21 and FIG. 22 from a different angle. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments according to the present disclosure will be described with reference to the accompanying drawings.

[0024] Herein, wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Directional references such as "top," "bottom," "right," and "left" are intended to facilitate reference to the drawings and are not intended to limit the scope of the present disclosure.

[0025] The embodiments disclosed herein present structures that can enable and improve the performance of safe fuel vapor release and sealing against liquid fuel leaks, for example, from a vehicle's fuel tank. Given the high flammability and high energy density of fuel, reliable performance in safety systems is particularly important. For example, safety systems are needed to ensure the safe release of vapors released by liquid fuel stored in the tank without increasing pressure within the tank. For example, elevated ambient temperatures and / or strong solar radiation can increase the temperature of the fuel tank and its contents, increasing the rate at which fuel vapors form. As another example, when a device or mechanism is provided for the safe release of liquid fuel vapors from a tank, additional safety mechanisms are needed to ensure that the vapor release pathway does not also serve as a pathway for liquid fuel release, i.e., to prevent unintended leakage. For example, if a tank is overfilled during refueling, liquid fuel levels may leak through a pathway intended for the release of fuel vapor, unless this risk is anticipated and mitigated. As a further example, if a fuel vapor release path is sealed against leakage due to an overfill event, the design of the safety mechanism described above must ensure that full functionality of the safety system (e.g., fuel vapor release) is quickly restored when the fuel level subsequently drops below the overfill. As another example, the design must ensure that the safety function maintains performance under external forces or perturbations, such as when the vehicle is positioned on an incline (parked or in motion), and / or under significant vehicle motion, such as rapid acceleration, braking, or cornering.

[0026] FIG. 1 illustrates a cross-sectional side view of an embodiment of a compact combo valve (CCV) assembly 100 in a fully assembled configuration. In one embodiment, the CCV assembly 100 may include a graded vent valve (GVV) 102 and a fill limit valve (FLV) 104. By way of non-limiting example, the GVV 102 and FLV 104 may be arranged in a stacked configuration (not shown) to form the CCV assembly 100 with a small footprint, thereby reducing potential permeation, although other suitable configurations are contemplated according to the present disclosure. In one embodiment, a base 106 of the CCV assembly 100 may connect to a vehicle's fuel tank, e.g., to the top of the fuel tank, thereby allowing the contents of the fuel tank (e.g., fuel) to communicate with the CCV assembly 100. An outlet port 108 located at the top of the CCV assembly 100 may be configured as an outlet conduit for fuel vapors vented from the fuel tank. By being placed at the top of the fuel tank, the CCV assembly 100 can prevent liquid leakage under various conditions, such as when the vehicle is traveling or parked at an angle, or when the vehicle is undergoing vigorous dynamic movement.

[0027] Although an example configuration of the present disclosure and details of the present disclosure are described using a CCV to provide a thorough understanding of the embodiments, it will be apparent to one skilled in the art that embodiments of the present disclosure may also be implemented in any other vent valve or fuel tank component where fluid leakage needs to be prevented.

[0028] 2 illustrates an exploded view of an embodiment of a GVV 200, which may generally include a housing 202, a flapper 204, and a float 206. In one embodiment, the housing 202 may house the float 206 to allow the float 206 to move relative to the housing 202 (e.g., along the centerline or y-axis, as shown) in response to the liquid fuel level. For example, under normal operating conditions, the float 206 may typically remain in a lower position within the housing 202. However, if the vehicle is positioned at an extreme angle, for example, and liquid fuel enters the housing 202 (e.g., via an end cap 210 located near the bottom of the housing 202), the buoyancy of the float 206 caused by any liquid fluid within the housing 202 may cause the float 206 to rise to a raised position. In one embodiment, the housing 202 and the float 206 may be made of a suitable material so that the interface between the housing 202 and the float 206 has desired properties, such as low friction, to facilitate movement of the float 206.

[0029] The y-axis of GVV 200 may be substantially perpendicular to a vehicle positioned on a horizontal surface, but the y-axis does not necessarily coincide with a normal vector (e.g., relative to the gravity vector) when the vehicle is positioned on an inclined surface. In the latter situation, float 206 remains constrained within housing 202 and is guided by float guides (the details of which are described below) and can move along the y-axis of GVV 200 based on the y-component of the buoyancy force acting on it.

[0030] In one embodiment, the flapper 204 may be positioned above the float 206, e.g., on the top surface of the float 206. As a non-limiting example, the float 206 may be provided with a retention mechanism to engage the flapper 204. In one embodiment, the flapper 204 may be movable relative to the float 206. For example, the flapper 204 may open and / or close to enable and / or disable a fluid path through the float 206. By doing so, fluid pressure may be equalized across the float 206 (i.e., above and below the float 206). Furthermore, in one embodiment, the flapper 204 may be configured as a seal to close an opening in the housing 202 when the float 206 moves to its raised position (e.g., the highest position available inside the housing 202). This may be useful, for example, in an overfill situation where it is necessary to prevent liquid fuel from leaking through an opening in the housing 202, as described in more detail below.

[0031] In one embodiment, a biasing element 208, such as a coil spring, may be provided, and a biasing element 210 may be coupled to the float 206 and configured to bias the float 206 to the raised position. By way of non-limiting example, one end of the biasing element 208 may be supported by the end cap 210, while the other end of the biasing element 208 may push against the float 206. The biasing force provided by the biasing element 208 may not necessarily be great enough to lift the float 206 alone; the biasing element 208 may cooperate with a buoyant force generated by any liquid entering the housing 202 to move the float 206 to the raised position.

[0032] Although the above-described embodiments are described with reference to GVVs having particular components in particular ways, the present disclosure contemplates configuring GVVs in any suitable manner and with any suitable components, as will be understood by those skilled in the art. As a non-limiting example, in some embodiments, GVV 200 may further include an O-ring 212 that may be disposed around the top of housing 202 for retention and / or leak resistance. Other suitable features may also be provided but will not be described in detail to avoid obscuring the scope of the present disclosure.

[0033] FIG. 3 illustrates a cross-sectional view of a GVV 200 according to the present disclosure. In one embodiment, the housing 202 can include an inner wall 306 and an outer wall 308, which together can form a chamber therebetween. In one embodiment, the float 206 can be housed within the chamber of the housing 202, e.g., movably, with the inner surface 310 facing the inner wall 306 and the outer surface 312 facing the outer wall 308. As a non-limiting example, the float 206 can have an orifice extending along the y-axis. The inner wall 306 of the housing 202 can be positioned within the orifice, with the inner surface 310 of the orifice facing the inner wall 306 of the housing 202. In one embodiment, the float 206 and the housing 202 can form an exemplary approximate path (shown by dashed arrow 314) for releasing fuel vapors, for example, from a fuel tank through the GVV 200. For example, while the position of float 206 along the y-axis is determined by the liquid fuel level in the fuel tank, as described above, a small gap may exist between float 206 and housing 202, particularly at the interface between the outer surface of float 206 and outer wall 308 of housing 202. Fuel vapor from the fuel tank may flow into housing 202, for example, through end cap 210, and flow around float 206 through this small gap, occupying the volume within housing 202 above float 206. In one embodiment, a valve mechanism such as a disk-type head valve (hereinafter, "disk valve 302") may be positioned over orifice 304 near the top of housing 202 and may be designed and calibrated to open at a predetermined pressure level and release fuel vapor accumulation through orifice 304. For example, disk valve 302 may be designed to open at a vapor pressure above 5 kPa or other suitable pressure level, thereby preventing pressure buildup above its designed opening pressure. Although the embodiments are described as having disc valves, it will be understood that other suitable types of valves familiar to those skilled in the art may be employed to perform the desired functions of the present disclosure.

[0034] In one embodiment, the orifice 304 communicating with the disk valve 302 may be positioned parallel to but offset from the y-axis of the housing 202. This can be seen more clearly in FIG. 4, which shows different cross-sectional views of the housing 202, one from above and one from the side, with the disk valve 302 omitted for clarity. In the illustrated plan view, the y-axis extends through the center of the housing 202 and points into and / or out of the page, while the orifice 304 is positioned radially outward from the y-axis. As can be seen from the side view at the bottom of FIG. 4, in one embodiment, the orifice 304 (and disk valve 302) may be positioned in precise alignment with the flapper 204, for example, along an axis 402 extending parallel to the y-axis. This can assist in proper sealing of the orifice 304 when the float 20 moves to its raised position, thereby avoiding undesired liquid leakage, as described below.

[0035] Continuing to refer to FIG. 4 and returning to FIGS. 2 and 3, in one embodiment, flapper 204 may be located on an upper surface of float 206. One purpose of flapper 204 is to close the fuel vapor release passage through orifice 304 and subsequently close disc valve 302 when the liquid fuel level rises above a certain level, for example, in an overfill situation when attempting to fill a fuel tank beyond its rated capacity. Closing the release passage helps prevent possible leakage of liquid fuel passing through disc valve 302 via the vapor release passage via orifice 304. At certain high levels of liquid fuel, such as during a fuel overfill, float 206 may rise within housing 202 to a position where the upper surface (hereinafter sometimes referred to as the “ribbon surface”) of flapper 204 is pressed against the lower surface of orifice 304, depending on the liquid fuel level. In this position, the flapper 204 prevents any fuel from escaping through the orifice 304 by closing the orifice 304, for example, in a fluid-tight manner.

[0036] 5-6 show the float 206 and flapper 204 assembly near the top of the float's 206 range of travel, with ribbon surface 602 attempting to engage and thereby seal orifice 304 with each incremental upward movement of float 206. In one embodiment, to provide a better seal, flapper 204, and more particularly, ribbon surface 602 of flapper 204, may be fabricated from a flexible and / or deformable material, such as an elastomer. Configured in this manner, as float 206 rises to its top position, ribbon surface 602 may further compress and form a seal around the entrance to orifice 304, thus enhancing leak protection.

[0037] Additionally or alternatively, flapper 204 may be designed to quickly restore functionality of the vapor release passageway through disc valve 302 if the liquid fuel level drops below its previous maximum level, e.g., by opening flapper 204 to equalize fluid pressure across (i.e., above and below) the upper surface of float 206, as described below.

[0038] 7-8 show the flapper 204 in a closed position. In the closed position, the underside of the flapper 204 can fully abut the top surface of the float 206. In the closed position, the flapper 204 covers a fluid passageway (not visible in the drawings) that extends inside the body of the float 206, thereby preventing fluid communication from the fuel tank through the float 206 to the volume above the float 206 within the housing 202. For example, during normal operation, an approximate vapor path (shown in FIG. 3 ) is available for fuel vapor release through the gap between the float 206 and the housing 202, but when the flapper 204 is open, there is also an additional path through a cavity or passageway (not visible in the drawings) within the body of the float 206 that allows fuel vapor to pass past the flapper 204. This additional path through the body of the float 206 is normally kept closed by the flapper 204 in its closed state at the top surface of the float 206.

[0039] In one embodiment, the flapper 204 may be configured to be openable. As a non-limiting example, the flapper 204 may be openable by lifting and / or tilting it relative to the top surface of the float 206. In one embodiment, the flapper 204 may be connected to the float 206 by a flapper guide 702 disposed on the top surface of the float 206, which allows the flapper 204 to be lifted and / or tilted relative to the float 206. In some embodiments, the flapper guide 702 may further limit the maximum possible degree of lift and / or tilt of the flapper 204 relative to the float 206.

[0040] In one embodiment, the flapper 204 may have a relatively rigid frame 704 that may be connected to the flapper guide 702 and a baffle 706 that extends in an arched manner above the frame 704. By way of non-limiting example, the baffle 706 may include a ribbon surface made of a flexible and / or deformable material, such as an elastomer as described above, thereby allowing the baffle 706 to sustain numerous deformation cycles without substantial material failure or movement. In this manner, when the float 206 moves to its uppermost position and engages the orifice 304 (e.g., due to a rise in the liquid fuel level), the baffle 706 may compress to seal against the entrance of the orifice 304, providing a high degree of leak protection.

[0041] 9 shows the flapper 204 in an open position. It can be seen that the flapper 204 is lifted (i.e., moved upward relative to the top surface of the float 206) and tilted (i.e., rotated relative to the top surface of the float 206, the tilt rotation being clockwise in the exemplary frame of this figure). While shown lifted and tilted to a particular degree of opening, this disclosure is not so limited. Other suitable open positions of the flapper are contemplated in this disclosure to achieve the desired functionality.

[0042] In one embodiment, following an event in which the float 206 and flapper 204 rise to their highest float position to block the vapor release path through the orifice 304 based on a high liquid fuel level, the fuel level may drop, such as due to fuel use to operate the vehicle. In this situation, the float 206 is required to track the current falling liquid fuel level and move downward (i.e., along the y-axis) to expose the vapor release path and restore its ability to release unwanted fuel vapors. However, without this configuration, the float 206 may not easily move downward in response to a drop in fuel level. The difficulty in moving the float 206 downward may arise because the instantaneous fluid pressure in the volume above the float 206 tends to decrease based on the volume expansion, and a decrease in pressure above the float 206 prevents the float 206 from moving downward based on the relative pressure across (i.e., above and below) the float 206. In such a situation, the flapper 204 is designed to open and equalize the pressure above and below the float 206, allowing the float 206 to move downward in conjunction with a drop in the liquid fuel level, thereby exposing the orifice of the orifice 304 and the vapor release passage.

[0043] FIG. 10 illustrates an example arrangement of the housing 202, flapper 1014, and float 206. In one embodiment, it may be desirable to minimize leakage of liquid fuel through the vapor release passageway to the greatest extent possible. For high sealing performance, it may be desirable for the flapper 1014 to be precisely and closely aligned with the orifice of the orifice 304 when the float 206 moves to its uppermost position. Misalignment in terms of relative movement (e.g., lateral or transverse to the y-axis), offset, and / or tilt in position can adversely affect sealing performance. As an example, deviations of the float 206 (and thereby the flapper 1014) can occur according to several factors, such as operating conditions, external forces, or perturbations acting on the float 206. For example, with reference to at least the side views of the assembly as seen in FIGS. 3-6, when a vehicle is positioned on an inclined surface, the buoyancy forces acting to lift the float 206 against the direction of gravity are not parallel to the available path of movement of the float 206 in the y-direction. As a result, a rotational or tilting moment acts on the float 206 along with the translational component of the resultant force, tending to displace the relative position of a sealing mechanism, such as the flapper 1014 on the float 206, with respect to the valve orifice 304 on the housing 202. Similarly, when the vehicle experiences violent maneuvers such as acceleration or sharp turns, significant fluid motions, such as sloshing or swirling, can act on the float 206 as well as other float components, displacing them from their aligned positions with respect to the valve orifice 304.

[0044] Therefore, to assist in aligning or centering the float 206 relative to the housing 202 and prevent undesired shifts in their position, an alignment and / or guide mechanism may be provided that guides the movement of the float 210 as the float 206 moves inside the housing 202. In this manner, precise positioning of the flapper 1014 relative to the valve orifice 304 is achieved. The valve orifice 304 is shown as a structure of the ring 1002, which may reduce the possibility of fluid leakage, particularly due to misalignment.

[0045] Although the embodiments disclosed herein are described using the term "alignment mechanism," other terms suitable for guiding movement or alignment, such as "guide mechanism," may be used interchangeably.

[0046] In some embodiments, one or more float guides 1004, 1006 may be provided within the housing 202. As a non-limiting example, the float guides 1004, 1006 may be disposed on the outer wall 308 of the housing 202 and extend inward toward the float 206. Correspondingly, one or more float guide channels 1008, 1010 may be provided on the outer surface 312 of the float 206 and configured to engage with the float guides 1004, 1006 of the housing 202. However, in such a design, hydrodynamic and / or mechanical effects acting on the float 206, such as swirling fluid motion, may be amplified due to the relatively large cross-sectional area of ​​the channels 1008, 1010 receiving the fluid flow and / or due to the outer radial location of the channels 1008, 1010, which disadvantageously provides a large moment length for the resulting forces on the float 206.

[0047] 11-12 illustrate other embodiments of the float 206 and the housing 202, both of which may include one or more alignment features similar to those described above. In one embodiment, one or more float guides 1102 may be disposed on the inner wall 306 of the housing 202 and face outward toward the float 206. As a non-limiting example, in the illustrated configuration, four float guides 1102 may be evenly spaced radially on the inner wall 306 of the housing 202. Correspondingly, the float 206 may also be provided with one or more (e.g., four shown) float guide channels 1104 on the inner surface 310. The floats 206 may be equally spaced radially from one another and configured to fit into the float guides 1102 of the housing 202. As further illustrated, in one embodiment, the float guides 1102 may optionally be provided with knobs or rounded protrusions 1106, for example, at the tips of the float guides 1102. This can be seen more clearly in Figure 12, where the float guide 1102 and float guide channel 1104 are enlarged to better show the details. When the knob 1106 extends into the float guide channel 1104, it contacts the float guide channel 1104, or at least reduces the clearance between the float guide 1102 and the float guide channel 1104, thereby further restricting the lateral freedom of movement of the float 206 relative to the housing 202. Of course, the knob 1106 may be shaped differently than shown without departing from the scope of this disclosure.

[0048] While described in this particular manner, those skilled in the art will appreciate that other suitable numbers (e.g., 2, 3, 5, 6, etc.) and arrangements of alignment features (e.g., float guides and float guide channels) are possible to perform the desired functions of the present disclosure. For example, in some embodiments, the number of float guides may be increased to allow for tighter alignment due to the more uniform and distributed restraining action of the float guides on the float, limiting undesired displacement and movement during the float's intended longitudinal translation. Furthermore, a greater number of float guide channels may reduce the cross-sectional area required to guide and restrain movement. These smaller cross-sectional areas may reduce the surface area within the float that is available and presented to fluid movement. Additionally, the location of the float guide channels at the inner radius of the float may reduce the moment length available for the action of fluid forces impinging on the float. Such limited relative displacement, force, and movement of the float may further contribute to improved alignment between the flapper and the valve orifice, thereby reducing fuel leakage and improving sealing capabilities.

[0049] FIG. 13 illustrates another embodiment of an alignment mechanism for the float 206 and the housing 202. This configuration may be similar to that described above with reference to FIGS. 11-12 in that four sets of float guides and float guide channels may be provided radially on the inner wall 306 of the housing 202 and the inner surface 310 of the float 206, respectively. In addition, one or more additional float guides 1302 may be configured on the outer wall 308 of the housing 202. The outer surface 312 of the float 206 may be configured with one or more additional float guide channels 1304 for receiving the associated float guides 1302 therein. By way of example and not limitation, the additional float guides 1302 and float guide channels 1304 may have reduced cross-sectional areas to minimize hydraulic forces acting on the float 206. In one embodiment, the outer periphery or surface 312 of the float 206 can further include a slot with one or more vapor relief notches 1306, which can help optimize the flow of fuel vapor through the clearance between the float 206 and the housing 202. Again, while described and shown in this particular manner, those skilled in the art should understand that other suitable configurations of the float and housing may be used. For example, additional float guides, float guide channels, and the number of vapor relief notches may be provided differently than those shown without departing from the scope of the present disclosure.

[0050] FIG. 14 shows an isolated view of the float 206 (with the flapper 204 omitted) from another angle, more clearly showing the alignment features (i.e., float guide channel 1104, additional float guide channel 1304) and vapor relief notch 1306. As can be seen from the drawing, the float guide channel 1104 may have a significant longitudinal length along the y-axis height of the float 206, i.e., into the page. Similarly, although not visible from this angle, the additional float guide channel 1304 may also extend through the entire height of the float 206 in the y-axis. In one embodiment, on the other hand, the vapor relief notch 1306 may have a length much less than the height of the float 206, for example, to facilitate vapor escape while only slightly limiting the hydraulic forces acting on the float 206.

[0051] 15 shows the float guide 1102 of the housing 202 from another angle. In one embodiment, the float guide 1102 may have a length substantially equal to the length of the float guide channel 1104, such that when inserted, the float guide 1102 extends entirely (e.g., along the y-axis) through the float guide channel 1104. This may, for example, provide better guidance and constraints for the movement of the float 206, preventing misalignment of the float 206 and its various components (such as the flapper 204) as it moves up and down inside the housing 202 in response to changes in the liquid fuel level.

[0052] The above dimensions and configurations of the alignment features and / or other features (such as steam relief notches) are provided by way of example only and are not intended to limit the scope of the present disclosure. Other suitable dimensions and configurations for performing the desired functions are also contemplated by this disclosure.

[0053] As discussed above, misalignment of the float relative to the housing, and more particularly, the flapper relative to the valve orifice, can affect sealing performance and cause undesirable fluid leakage. In one embodiment, as discussed above with reference to Figures 7-8, the flapper 204 may be connected to the float 206 by a flapper guide 702 disposed on the upper surface of the float 206. As a non-limiting example, the flapper guide 702 allows the flapper 204 to lift and / or tilt relative to the upper surface of the float 206. In other examples, the flapper guide 702 may further limit the maximum possible lift and / or tilt of the flapper 204 relative to the float 206.

[0054] 16-22 show several embodiments of various flapper and flapper guide combinations. Undesirable deviations in flapper position in the form of relative movement (e.g., in a lateral direction), offset, and / or tilt can occur due to unintended relative movement of the flapper and float. For example, the flapper may lift open due to balancing pressure across the float, but upon return, the flapper may not return to its proper relative position and may not align with the valve orifice, which may be the result of, for example, insufficient engagement between the flapper and flapper guide.

[0055] For example, in an embodiment such as that shown in FIG. 16 (as well as FIG. 10), the cross section of the flapper guide 1012 may narrow or taper toward the side of the flapper guide 1012 that faces the flapper 1014 (as can be seen more clearly in the top view of FIG. 10). Such a tapered shape may subject the flapper 1014 to excessive displacement or movement relative to the flapper guide 1012, such as a tendency to twist or rotate about the flapper guide 1012, e.g., about an axis parallel to the longitudinal direction of the float 206, as viewed in plan view.

[0056] 17-18 illustrate a first exemplary configuration of a flapper guide 1702 and a flapper 1802 according to the present disclosure. In one embodiment, the flapper guide 1702 may be in the form of a hinge. For example, both ends may be permanently connected to the top surface of the float 206, forming a channel 1704. In one embodiment, the flapper 1802 may include a post 1804. As a non-limiting example, one end of the post 1804 may be connected to the base frame 1806 of the flapper 1802 in a cantilevered manner so that the flapper 1802 can rotate about the post 1804 during operation. The other end of the post 1804 may be configured with an enlarged knob 1808. In one embodiment, the post 1804 may be separated along its length. When configured in this manner, for example, the post 1804 may be briefly compressed and inserted into the channel 1704 of the flapper guide 1702 during assembly. Upon release, the post 1804, through its enlarged knob 1808, can hold the flapper 1802 in place relative to the flapper guide 1702, allowing the flapper 1802 to open and / or close and limiting its lateral movement. Additionally, in one embodiment, the flapper guide 1702 can be notched on one or both sides to form a stop 1706 that limits the opening of the flapper 1802 to a desired level, thereby preventing over-rotation of the flapper 1802.

[0057] 19 and 20 illustrate a second exemplary configuration of a flapper guide 1902 and a flapper 2002 according to the present disclosure. In one embodiment, the flapper guide 1902 may be in the form of a hinge. For example, one end thereof may be permanently connected to the top surface of the float 206, while the other end (free end, 1906) may be positioned adjacent to the top surface of the float 206 without being fixedly connected thereto. In one embodiment, the flapper guide 1702 may form a channel 1904 that engages with the flapper 2002, similar to the channels described above. In one embodiment, the flapper 2002 may include one or more posts, e.g., posts 2004, 2006, that are connected to a base frame 2008 of the flapper 2002. As a non-limiting example, the ends of the posts 2004, 2006 are spaced apart from one another by a small distance. Thus, the posts 2004, 2006 temporarily spread apart under the stress of the components to assemble the flapper 2002 to the flapper guide 1902, and then, when the posts 2004, 2006 enter the channel 1904, they return to their original position to hold the flapper 2002 in place, thereby allowing the flapper 2002 to open and / or close and limiting its lateral movement. Alternatively, although not shown, a single post may be provided, which passes through the gap between the free end 1906 and the top surface of the float 206 and snaps into the channel 1904 during assembly, thereby rotatably securing the flapper 2002 to the flapper guide 1902. Similarly, in one embodiment, the flapper guide 1902 may have a notch on one or both sides to form a stop 1908 that limits the opening of the flapper 2002 to a desired level, thereby preventing the flapper 2002 from opening beyond the stop 1908.

[0058] 21 and 22 illustrate a third exemplary configuration of a flapper guide 2102 and a flapper 2202 according to the present disclosure. In one embodiment, the flapper guide 2102 may be formed as a rib that protrudes outward from the top surface of the float 206. For example, the flapper guide 2102 may have a wide cross-section, for example, at its base. By way of non-limiting example, the cross-section of the flapper guide 2102 may be formed as a generally square, rectangular, rounded rectangular, or the like. The large and widely distributed cross-sectional area of ​​the ribbed flapper guide 2102 can provide the benefit of significantly restraining the flapper 2202 from, for example, lateral displacement and / or rotation relative to the valve orifice of the housing. Furthermore, the limited displacement and precise alignment relative to the valve orifice can reduce fuel leakage and improve sealing and flapper reopening capabilities. In one embodiment, the flapper guide 2102 can be configured with a notch 2104 near its top to allow lifting and / or tilting of the flapper 2202 relative to the top surface of the float 206 while limiting the maximum possible range of movement of the flapper 2202 as it lifts and / or tilts. In one embodiment, the flapper 2202 can include connector ends 2204, 2206 that extend from the frame 2212 and engage with the flapper guide 2102, for example, by mating or snapping onto the base of the flapper guide 2102. As a non-limiting example, the connector ends 2204, 2206 can temporarily spread apart under stress of the components to assemble the flapper 2202 to the flapper guide 2102, and then be released to substantially return to their original position, holding the flapper 2202 in place while allowing the flapper 2202 to open and / or close. Additionally, in one embodiment, the bases of connector ends 2204, 2206 may include relief notches 2208, 2210, respectively.For example, the relief notches 2208, 2210 can reduce stresses imparted to the material when the connector ends 2204, 2206 are temporarily separated for assembly, which can reduce permanent deformation of the flapper 2202 and therefore improve, for example, the alignment performance of the flapper 2202 relative to the valve orifice of the housing, as well as the overall component durability and reliability over its operational life. Furthermore, with limited displacement and precise alignment, the features of the present disclosure can contribute to reducing fuel leakage and improving the sealing and reopening capabilities of the flapper.

[0059] 23 shows the flapper 2202 and flapper guide 2102 in an assembled configuration, with the flapper 2202 shown in its closed position. As previously explained, when closed, the flapper 2202 rests sufficiently on top of the float 206 to cover the flow passage (not visible in the drawing) that extends inside the body of the float 206, thereby preventing flow through the float 206 to the volume above the float 206 within the housing.

[0060] Additionally, for purposes of illustration only, FIGS. 24-25 show some example dimensions of the flapper 2202 and flapper guide 2102. In one embodiment, the frame 2212 of the flapper 2202, which may be made of, for example, a relatively rigid material, generally has a length L1 of about 13.17 mm and a width W1 of about 10.00 mm. In one embodiment, the deformable baffle 2402 arching over the frame 2212 may generally have a length L2 of about 7.39 mm. In one embodiment, the flapper guide 2102 may be angled relative to the upper surface of the float 206. By way of non-limiting example, the front side of the flapper guide 2102 (i.e., the side facing the substantial portion of the flapper 2202) may be angled at an angle θ1 of about 76.7 degrees, and the back side of the flapper guide 2102 (i.e., the side that engages the connector ends 2204, 2206) may be angled at an angle θ2 of about 82.5 degrees. In one embodiment, the notch 2104 may be angled at an angle θ3 of, for example, about 13 degrees relative to the top surface of the float 206. In one embodiment, the base portion of the flapper guide 2102 may have a length L3 of about 1.81 mm.

[0061] Those skilled in the art will recognize that the above dimensions are provided for illustrative purposes only and are not necessarily required. While the present disclosure describes the flapper and flapper guide as having particular dimensions in a particular manner, the present disclosure contemplates the flapper and flapper guide as having any suitable dimensions in any suitable manner. Furthermore, the present disclosure contemplates not only the combinations of features described above and illustrated in the drawings, but also any other suitable combinations of features. For example, the flapper 1802 described with reference to FIG. 18 can be applied to the flapper guide 1902 described with reference to FIG. 19 . The flapper 2002 described with reference to FIG. 20 can also be applied to the flapper guide 1702 described with reference to FIG. 17 . The presently disclosed embodiments should be considered in all respects as illustrative and not restrictive. An embodiment may include all or none of the components, elements, features, functions, or operations of the above-disclosed embodiments.

[0062] As used herein, "or" is inclusive and not exclusive, unless expressly indicated otherwise or necessitated by context. Thus, as used herein, "A or B" means "A, B, or both," unless expressly indicated otherwise or necessitated by context. Furthermore, "and" is both jointly and severally, unless expressly indicated otherwise or necessitated by context. Thus, as used herein, "A and B" means "A and B together or separately," unless expressly indicated otherwise or necessitated by context.

[0063] The scope of the present disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the exemplary embodiments described or illustrated herein that would be understood by a person skilled in the art. The scope of the present disclosure is not limited to the exemplary embodiments described or illustrated herein. Furthermore, although the present disclosure describes and illustrates each embodiment herein as including particular components, elements, features, functions, operations, or steps, any of these embodiments may include any combination or permutation of any of the components, elements, features, functions, operations, or steps described or illustrated anywhere herein that would be understood by a person skilled in the art. Furthermore, references in the appended claims to an apparatus or system, or a component of an apparatus or system, that is adapted, arranged, capable, configured, enabled, operative, or operates to perform a particular function encompass that apparatus, system, or component, so long as the apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operative, or operates, regardless of whether the apparatus, system, or component, or that particular function, is activated, turned on, or unlocked. Furthermore, while this disclosure describes or illustrates an embodiment as providing certain advantages, an embodiment may provide none, some, or all of these advantages.

Claims

1. 1. A vent valve assembly for a fuel tank, comprising: a housing having an outer wall structure and an inner wall structure, the housing having a chamber formed therebetween; a float disposed inside the chamber and movable relative to the housing along an axis; the float has an orifice extending along the axis; the inner wall structure of the housing is disposed within the orifice of the float; an inner surface of the orifice of the float is positioned to face the inner wall structure of the housing; The vent valve assembly comprises: one or more guide mechanisms disposed on an inner surface of the orifice of the float; one or more mating guide features disposed on the inner wall structure of the housing and configured to mate with the one or more guide features; A vent valve assembly, wherein the one or more guide mechanisms and the one or more mating guide mechanisms cooperate to guide relative movement of the float along the axis relative to the housing and to limit rotation of the float about the axis.

2. 2. The vent valve assembly of claim 1, wherein the one or more guide mechanisms extend along the axis substantially the entire length of the float.

3. The vent valve assembly of claim 1 , wherein a length of the one or more guide features is substantially the same as a length of the one or more mating guide features.

4. The vent valve assembly of claim 1 , wherein the one or more guide features are configured as guide channels.

5. The vent valve assembly of claim 4 , wherein the one or more mating guide features are configured as guides that are inserted into the guide channels.

6. 2. The vent valve assembly of claim 1, wherein the one or more guide features are uniformly distributed radially on the inner surface of the float orifice.

7. The vent valve assembly of claim 1 , wherein the one or more mating guide features are uniformly distributed radially on the inner wall structure of the housing.

8. The vent valve assembly of claim 1 , wherein the one or more mating guide features include a knob.

9. The vent valve assembly of claim 1 , wherein four guide mechanisms and four mating guide mechanisms are provided.

10. one or more additional guide mechanisms disposed on the outer surface of the float; The vent valve assembly of claim 1 , further comprising one or more additional mating guide features disposed on the outer wall structure of the housing and configured to mate with the one or more additional guide features.

11. 1. A vent valve assembly comprising: a housing having an outer wall structure, an inner wall structure, and a valve orifice, the housing defining a chamber between the outer wall structure and the inner wall structure; a float disposed inside the chamber and movable relative to the housing along an axis; a flapper disposed on an upper surface of the float and aligned with the valve orifice; a flapper guide disposed on the upper surface and configured to engage with the flapper; The flapper guide allows the flapper to open and close and keeps the flapper aligned with the valve orifice.

12. 12. The vent valve assembly of claim 11, wherein the flapper guide is a hinge having two ends each connected to an upper surface of the float.

13. 12. The vent valve assembly of claim 11, wherein the flapper guide is a hinge having one end connected to the top surface of the float and another end not connected to the top surface of the float.

14. The vent valve assembly of claim 11 , wherein the flapper guide includes a channel.

15. 15. The vent valve assembly of claim 14, wherein the flapper includes one or more posts rotatably inserted into channels in the flapper guide.

16. The vent valve assembly of claim 11 , wherein the flapper guide includes a stopper configured to limit the opening of the flapper.

17. The vent valve assembly of claim 11 , wherein the flapper guide is a rib.

18. 12. The vent valve assembly of claim 11, wherein the flapper guide includes a base having a large cross-sectional area to limit lateral movement of the flapper.

19. 20. The vent valve assembly of claim 18, wherein the cross-sectional area of ​​the base is rectangular.

20. The vent valve assembly of claim 11 , wherein the flapper includes one or more connector ends.

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