Exhaust valve assembly

Abstract

A vent valve assembly for use with a fuel tank may include a housing having an outer wall structure and an inner wall structure defining a chamber therebetween; and a float located within the chamber and configured to be translatable relative to the housing along an axis. The float has an aperture extending along an axis. An inner wall structure of the housing is disposed within the orifice of the float and faces an inner surface of the orifice. The vent valve assembly further includes one or more guide features on the inner surface of the float; and one or more mating guide features on the inner wall structure of the housing and configured to mate with the guide features. The guide feature and the mating guide feature cooperate to guide translation of the float relative to the housing along the axis and limit rotation of the float about the axis.

Description

[0001] Citation of Related Applications

[0002] This disclosure is based on and claims priority to Indian Provisional Application No. 202211054223, filed on September 22, 2022, entitled "Feature Structure for Improving Sealing Performance in a CCV", the entire content of which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to fuel storage systems, and more particularly to an exhaust valve assembly for a fuel tank of a vehicle. Background Art

[0004] Fuel tanks of vehicles typically utilize safety systems to ensure safe and consistent operation under a range of conditions. Generally, the safety system can open the fluid communication between the fuel tank and other components of the fuel system under normal conditions to allow pressurized fuel vapor to escape from the fuel tank, and can close the fluid communication between the fuel tank and other components of the fuel system, for example, in the case of overfilling of liquid fuel, when the vehicle is on an inclined surface, or during severe movement of the vehicle and / or fuel, to prevent liquid fuel from flowing out of the fuel tank. Given the high flammability and high energy density of fuel, the reliable performance of these safety systems is particularly important. Summary of the Invention

[0005] This disclosure presents an exhaust valve assembly having multiple components that enables safe discharge of fuel vapor while preventing accidental leakage of liquid fuel. Features are also disclosed that enable the system to operate properly under a range of operating conditions, such as overfilling, the vehicle being on an inclined surface, and / or significant vehicle and fuel movement. Additionally, in addition to providing vapor discharge and liquid leakage protection, the exhaust valve assembly of this disclosure can provide additional benefits in terms of production, such as low production cost, efficient packaging, and small system footprint.

[0006] In one embodiment, an exhaust valve assembly for use with a fuel tank is provided, comprising: a housing having an outer wall structure and an inner wall structure, the outer wall structure and the inner wall structure together defining a chamber therebetween; and a float located within the chamber and configured to translate relative to the housing along an axis. Specifically, 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 exhaust valve assembly further comprises: one or more guiding features located on the inner surface of the orifice of the float; and one or more mating guiding features located on the inner wall structure of the housing and configured to cooperate with the one or more guiding features. Specifically, the one or more guiding features and the one or more mating guiding features cooperate to guide the translation of the float relative to the housing along the axis and to restrict the rotation of the float about the axis.

[0007] In a specific embodiment, one or more guiding feature portions extend substantially along an axis through the entire length of the float.

[0008] In a specific embodiment, the length of one or more guiding feature portions is substantially equal to the length of one or more mating guiding feature portions.

[0009] In a specific embodiment, one or more guiding feature portions are configured as guiding passages. In a specific embodiment, one or more mating guiding feature portions are configured as guiding members inserted into the guiding passages.

[0010] In a specific embodiment, one or more guiding feature portions are uniformly distributed in the radial direction on the inner surface of the float.

[0011] In a specific embodiment, one or more mating guiding feature portions are uniformly distributed in the radial direction on the inner wall of the housing.

[0012] In a specific embodiment, one or more mating guiding feature portions include protrusions.

[0013] In a specific embodiment, four guiding feature portions and four mating guiding feature portions are provided.

[0014] In a specific embodiment, the exhaust valve assembly further includes: one or more additional guiding feature portions located on the outer surface of the float; and one or more additional mating guiding feature portions located on the outer wall of the housing and configured to cooperate with the one or more additional guiding feature portions.

[0015] In one embodiment, an exhaust valve assembly includes a housing having an outer wall structure, an inner wall structure, and a valve orifice. Specifically, the outer wall structure and the inner wall structure define a chamber therebetween. The exhaust valve assembly further includes: a float located within the chamber and configured to translate relative to the housing along an axis; a flap provided at an upper surface of the float and positioned to be aligned with the valve orifice; and a flap guide located at the upper surface and configured to engage with the flap. Specifically, the flap guide enables the flap to open and close and maintains the alignment of the flap with the valve orifice.

[0016] In a specific embodiment, the flap guide is a hinge member, and two end portions of the hinge member are respectively connected to the upper surface of the float.

[0017] In a specific embodiment, the flap guide is a hinge member, one end portion of the hinge member is connected to the upper surface of the float, and the other end portion of the hinge member is not connected to the upper surface of the float.

[0018] In a specific embodiment, the flap guide includes a passage. In a specific embodiment, the flap includes one or more posts that are rotatably inserted into the passage of the flap guide.

[0019] In a specific embodiment, the flap guide includes a stop configured to limit the degree of opening of the flap.

[0020] In a specific embodiment, the flap guide is a rib.

[0021] In a specific embodiment, the flap guide includes a base having a large cross-sectional area to limit lateral movement of the flap. In a specific embodiment, the cross-sectional area of the base is shaped as a quadrilateral.

[0022] In a specific embodiment, the flap includes one or more connecting ends. Description of the Drawings

[0023] Embodiments in accordance with the present disclosure will now be described with reference to the drawings, in which:

[0024] Figure 1 A schematic cross-sectional side view of an exemplary embodiment of a compact combination valve (CCV) assembly is depicted;

[0025] Figure 2 An exploded side view perspective of an exemplary embodiment of a graded vent valve (GVV) is depicted, which generally may include a housing, a flap, and a float;

[0026] Figure 3 A cross-sectional side view of the GVV is depicted;

[0027] Figure 4 A top view and a cross-sectional side view of the GVV are depicted, with some specific components omitted for better viewing;

[0028] Figure 5 An enlarged cross-sectional side view of the GVV is depicted, with the float in the raised position;

[0029] Figure 6 Depicts Figure 5 A close-up view of the float in, particularly showing the flap;

[0030] Figure 7 An embodiment of the flap as viewed from above is depicted;

[0031] Figure 8 Depicts as viewed from the side Figure 7 the flap in;

[0032] Figure 9 Depicts Figure 7 the flap in the open position;

[0033] Figure 10 depicts some exemplary embodiments of specific alignment features and the flap and flap guide;

[0034] Figure 11 and Figure 12 depicts one configuration of the alignment feature according to the present disclosure;

[0035] Figure 13 depicts another configuration of the alignment feature according to the present disclosure;

[0036] Figure 14 and Figure 15 depict the alignment features on the float and the housing according to the present disclosure, respectively;

[0037] Figure 16 depicts the flap and flap guide in Figure 10 as viewed from another angle;

[0038] Figure 17 and Figure 18 depicts one configuration of the flap and flap guide according to the present disclosure;

[0039] Figure 19 and Figure 20 depicts another configuration of the flap and flap guide according to the present disclosure;

[0040] Figure 21 and Figure 22 depicts yet another configuration of the flap and flap guide according to the present disclosure;

[0041] Figures 23 to 25 depict the flap and flap guide in Figure 21 and Figure 22 from different perspectives, respectively. DETAILED DESCRIPTION

[0042] Reference will now be made in detail to the examples illustrated in the drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. Directional references such as "upper", "lower", "right" and "left" are for convenience in referring to the drawings and are not intended to limit the scope of the present disclosure.

[0043] The embodiments disclosed herein present a reinforcement structure that can achieve and improve performance related to the safe emission of fuel vapors and the sealing against leakage of liquid fuel, such as from a fuel tank of a vehicle. Given the high flammability and high energy density of fuel, the reliable performance of the safety system is particularly important. For example, a safety system is required to ensure that the vapors released from the liquid fuel stored in the tank are safely released rather than being allowed to build up pressure within the fuel tank. For example, an increase in ambient temperature and / or strong solar radiation may raise the temperature of the fuel tank and its contents, thereby accelerating the rate of fuel vapor formation. As another example, if there are devices or features for safely allowing the vapor of liquid fuel to be released from the fuel tank, other safety features are needed to ensure that the vapor release path does not act as a liquid fuel release path, i.e., to prevent accidental leakage. For example, if the fuel tank is overfilled during the fuel filling process, the liquid fuel level may leak through the passage designed to release fuel vapors unless this risk is anticipated and mitigated. As yet another example, if the fuel vapor release passage is sealed based on an overfill event to prevent leakage, the design of the above safety features needs to ensure that all functions of the safety system, such as fuel vapor release, are quickly restored when the fuel level subsequently drops below the overfilled level. As a further example, the design aspect needs to ensure that the safety feature performance is maintained under external forces or disturbances, such as when the vehicle is positioned (parked or driving) on an inclined surface and / or under significant vehicle movements, such as hard acceleration, braking, or turning.

[0044] Figure 1 A cross-sectional side view of an embodiment of a Compact Combination Valve (CCV) assembly 100 in a fully assembled configuration is shown. In a specific embodiment, the CCV assembly 100 may include a Graded Vent Valve (GVV) 102 and a Fill Limit Valve (FLV) 104. By way of example and not limitation, the GVV 102 and the FLV 104 may be arranged in a stacked configuration as depicted, thereby forming a CCV assembly 100 with a small footprint, thus reducing potential permeation, but other suitable configurations are also contemplated by the present disclosure. In a specific embodiment, the base 106 of the CCV assembly 100 may be connected to the fuel tank of the vehicle, for example, to the top surface of the fuel tank, and allow the contents of the fuel tank (e.g., fuel) to be in fluid communication 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 the fuel vapors released from the fuel tank. Since the CCV assembly 100 is positioned at the very top of the fuel tank, it can prevent liquid leakage during various situations, such as when the vehicle is driving or parked at an angle, when the vehicle is experiencing aggressive driving dynamics, and so on.

[0045] While specific configurations and details of the present disclosure have been set forth in the context of a CCV to provide a thorough understanding of these embodiments, it will be apparent to those of ordinary skill in the art that embodiments of the present disclosure may be practiced in any other suitable exhaust valve or fuel tank component where fluid leakage prevention is desired.

[0046] Figure 2 A exploded view of an embodiment of the GVV 200 is shown, which generally may include a housing 202, a flap 204, and a float 206. In a particular embodiment, the housing 202 may accommodate the float 206 in a manner that allows the float 206 to translate relative to the housing 202 in response to a liquid fuel level (e.g., along a centerline or y-axis as shown). For example, under normal operating conditions, the float 206 may generally remain at a lower position inside the housing 202. However, if the vehicle is positioned at an extreme angle, such as an angle that causes liquid fuel to enter the housing 202 (e.g., via an end cap 210 disposed 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 a particular embodiment, the housing 202 and the float 206 may be made of a suitable material such that the interface between the housing 202 and the float 206 has a desired low-friction property, e.g., to facilitate translation of the float 206.

[0047] While the y-axis of the GVV 200 may be substantially vertical for a vehicle located on a horizontal surface, when the vehicle is located on an inclined surface, the y-axis does not necessarily coincide with a vertical vector (e.g., relative to the gravity vector). In the case where the y-axis does not coincide with the vertical vector, the float 206 may remain constrained within the housing 202 and be guided by a float guide (the details of which will be more thoroughly explained below) to translate along the y-axis of the GVV 200 based on the y-direction component of the buoyant force acting thereon.

[0048] In a specific embodiment, the flap 204 can be located on top of the float 206, for example, on the upper surface of the float 206. As an example and not a limitation, a retaining mechanism can be provided on the float 206 to engage with the flap 204. In a specific embodiment, the flap 204 can move relative to the float 206. For example, the flap 204 can open and / or close to allow fluid to pass through the float 206 and / or to prevent fluid from passing through the float. In doing so, the hydraulic pressure across the float 206 (i.e., above and below the float 206) can be balanced. Additionally, in a specific embodiment, the flap 204 can be configured as a seal to close an opening at the housing 202 when the float 206 is translated to its raised position (e.g., the uppermost position available inside the housing 202). This can be useful, for example, in overfill situations where it is necessary to prevent liquid fuel from escaping through the opening of the housing 202. This will be explained in more detail below.

[0049] In a specific embodiment, a biasing element 208 (such as a helical spring) can be provided, which can be coupled to the float 206 and configured to bias the float 206 into the raised position. As a non-limiting example, one end of the biasing element 208 can be supported by an end cap 210, while the other end of the biasing element 208 can push against the float 206. Although the biasing force provided by the biasing element 208 may not necessarily be large enough to lift the float 206 alone, the biasing element 208 can cooperate with the buoyancy force generated by any liquid entering the housing 202 to move the float 206 into the raised position.

[0050] Although the above embodiments are described by reference to a GVV having specific components in a specific manner, the present disclosure can also contemplate configuring the GVV with any suitable components in any suitable manner, as will be understood by those skilled in the art. As an example and not a limitation, in some embodiments, the GVV 200 can also include an O-ring 212, which can be positioned around the top of the housing 202 for retention and / or leakage prevention. Other suitable features can also be provided, but will not be described in detail to avoid obscuring the scope of the present disclosure.

[0051] Figure 3A cross-sectional view of the GVV 200 in accordance with the present disclosure is shown. In a particular embodiment, the housing 202 may include an inner wall 306 and an outer wall 308, which together may form a chamber therebetween. In a particular embodiment, the float 206 may be received, for example, movably within the chamber of the housing 202, wherein the inner surface 310 of the float 206 faces the inner wall 306 and the outer surface 312 of the float 206 faces the outer wall 308. By way of example and not limitation, the float 206 may have an orifice extending along the y-axis. The inner wall 306 of the housing 202 may be disposed within the orifice such that the inner surface 310 of the orifice may be positioned to face the inner wall 306 of the housing 202. In a particular embodiment, the float 206 and the housing 202 may form an exemplary general path (indicated by the dashed arrow 314) for releasing fuel vapor, for example, from a fuel tank through the GVV 200. For example, as discussed above, although the position of the float 206 along the y-axis is determined by the liquid fuel level in the fuel tank, there may be a small gap between the float 206 and the housing 202, particularly at the interface between the outer surface of the float 206 and the outer wall 308 of the housing 202. For example, fuel vapor from the fuel tank may flow into the housing 202 through the end cap 210, around the float 206 through this small gap, and occupy the volume above the float 206 within the housing 202. In a particular embodiment, a valve mechanism, such as a disk head valve (disk valve 302 hereinafter), may be located on the orifice 304 near the top of the housing 202 and may be designed and calibrated to open at a predetermined pressure level and release the accumulation of fuel vapor through the orifice 304. For example, the disk valve 302 may be designed to open at a vapor pressure of more than 5 kPa or other suitable pressure level and prevent pressure accumulation beyond the designed opening pressure. It should be understood that although this embodiment is described as having a disk valve, other suitable types of valves familiar to those skilled in the art may also be used to perform the desired functions of the present disclosure.

[0052] In a particular embodiment, the orifice 304 in communication with the disk valve 302 may be positioned parallel to but offset from the y-axis of the housing 202. This can be more clearly observed in Figure 4 which depicts different cross-sectional views of the housing 202, namely, one viewed from above and one viewed from the side, with the disk valve 302 omitted for clarity. In the top view shown, 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 seen from the side view (which is Figure 4 a cross-sectional view), the orifice 304 is offset from the y-axis. Figure 4As seen in the bottom view (not shown), in the specific embodiment, the orifice 304 (and the disc valve 302) can be positioned to be accurately aligned with the flap 204, for example, along an axis 402 extending parallel to the y-axis. When the float 206 is translated to its raised position, this can contribute to the proper sealing of the orifice 304, thus avoiding undesired liquid leakage, as will be discussed below.

[0053] Continuing to refer Figure 4 and returning to refer Figure 2 and Figure 3 In the specific embodiment, the flap 204 can be disposed at the upper surface of the float 206. One purpose of the flap 204 is to close the fuel vapor release passage through the orifice 304 when the liquid fuel level rises above a specific level (e.g., in the case of overfilling when the fuel tank is filled beyond its rated capacity), and thus close the disc valve 302. Closing the release passage can help prevent the possible leakage of liquid fuel through the disc valve 302 via the orifice 304 through the vapor release passage. At a specific high level of liquid fuel, such as during overfilling of the fuel, the float 206 can rise within the housing 202 in response to the liquid fuel level to a position where the upper surface of the flap 204 (sometimes also referred to as the "ribbon surface") can be pressed against the lower surface of the orifice 304. In this position, the flap 204 can close the orifice 304 in a fluid-tight manner, for example, thereby preventing any fuel from escaping through the orifice 304.

[0054] Figures 5 to 6 shows the float 206 and flap 204 assembly at almost the highest position within the travel range of the float 206, at which time the ribbon surface 602 is about to engage the orifice 304 based on further upward translation of the float 206, thereby sealing the orifice 304 closed. In the specific embodiment, to provide a better seal, the flap 204 or more specifically the ribbon surface 602 of the flap 204 can be made of a flexible and / or deformable material such as an elastomer. Configured in this way, when the float 206 rises to its highest position, the ribbon surface 602 can be further compressed and form a seal around the entrance of the orifice 304, thereby enhancing leak protection.

[0055] In addition or alternatively, the flap 204 can be designed to quickly restore the functionality of the vapor release passage through the disc valve 302 when the liquid fuel level drops back below its previous maximum level, for example, by opening the flap 204 to balance the fluid pressure across the upper surface of the float 206 (i.e., above and below), as will be discussed below.

[0056] Figures 7 to 8Shows the flap 204 in the closed position, where the lower surface of the flap 204 can fully abut against the top surface of the float 206. In its closed position, the flap 204 can cover a fluid passage (not visible in the figure) extending inside the body of the float 206, thereby prohibiting fluid communication from the fuel tank through the float 206 to the volume above the float 206 within the housing 202. For example, although the general vapor path ( Figure 3 shown in) can be used to release fuel vapor via the gap between the float 206 and the housing 202, there are also additional passages through cavities or channels (not visible in the figure) within the body of the float 206 that can allow fuel vapor to pass through the flap 204 when the flap 204 is open. This additional passage through the body of the float 206 is generally kept closed on the upper surface of the float 206 by the flap 204 in its closed state.

[0057] In a specific embodiment, the flap 204 can be configured to be openable. By way of example and not limitation, the flap 204 can be opened by lifting and / or tilting relative to the upper surface of the float 206. In a specific embodiment, the flap 204 can be connected to the float 206 by a flap guide 702 located at the upper surface of the float 206, which allows the flap 204 to lift and / or tilt relative to the float 206. In some embodiments, the flap guide 702 can also additionally limit the extent of the maximum possible lift and / or maximum possible tilt of the flap 204 relative to the float 206.

[0058] In a specific embodiment, the flap 204 can have a relatively rigid frame 704 and a baffle 706 that arches over the frame 704, and the frame can be connected to the flap guide 702. By way of example and not limitation, the baffle 706 can include a ribbon-like surface made of a flexible and / or deformable material (such as an elastomer) as described above, such that the baffle 706 can withstand a large number of deformation cycles without substantial failure in terms of material or operational intent. Thus, when the float 206 (e.g., due to the rise of the liquid fuel level) translates to its highest position and engages with the orifice 304, the baffle 706 can be compressed to seal against the inlet of the orifice 304, thereby providing a high degree of leak protection.

[0059] Figure 9 Shows the flap 204 in the open position, in which the flap 204 is seen to have lifted (i.e., moved upward relative to the upper surface of the float 206) and tilted (i.e., rotated relative to the upper surface of the float 206, where the rotation of the tilt is seen to be clockwise in the exemplary reference frame in this figure). Although depicted as being lifted and tilted to a particular degree of opening, it should be understood that the present disclosure is not limited thereto. The present disclosure also contemplates other suitable open positions of the flap to achieve the desired function.

[0060] In a specific embodiment, after the event that the float 206 and the flap 204 have risen to the uppermost float position to seal the vapor release passage through the orifice 304 based on the high liquid fuel level, the fuel level may subsequently drop, such as due to the use of fuel for operating the vehicle. In this case, the float 206 needs to track the now dropping liquid fuel level and translate downward (i.e., along the y-axis), thereby exposing the vapor release passage and restoring the ability to release unwanted fuel vapor. However, in the absence of a specific feature to address this problem, the float 206 may not be easily withdrawn downward based on the drop in the fuel level. The potential downward movement of the float 206 is difficult because the instantaneous fluid pressure in the volume above the float 206 will tend to decrease based on the increasing volume, and the decrease in the pressure above the float 206 will prevent the float 206 from moving downward based on the relative pressure across the float 206 (i.e., above and below). In this case, the flap 204 is designed to open and balance the pressure above and below the float 206, thereby allowing the float 206 to translate downward as the liquid fuel level drops, thus exposing the orifice of the orifice 304 and the vapor release passage.

[0061] Figure 10 An exemplary arrangement of the housing 202, the flap 1014, and the float 206 is shown. In a specific embodiment, it may be desirable to minimize any leakage of liquid fuel through the vapor release passage to the greatest extent possible. For high sealing performance, it may be desirable for the flap 1014 to be correctly and tightly aligned with the orifice of the orifice 304 when the float 206 moves to its topmost position. Misalignment in terms of relative translation (e.g., lateral or transverse with respect to the y-axis), offset, and / or positional tilt may adversely affect the sealing performance. As an example, the deviation of the float 206 (and thus the flap 1014) may occur due to multiple aspects of the operating conditions, external forces, or disturbances acting on the float 206. For example, referring to a side view of the components as seen in at least Figures 3 to 6 When the vehicle is on an inclined surface, the buoyant force acting on the float 206 to raise it against the direction of gravity is not parallel to the available translation path of the float 206 in the y-direction. Thus, together with the translational component of the resultant force, a rotational or tilting moment will act on the float 206, tending to displace the relative position of the sealing feature (such as the flap 1014 on the float 206) relative to the valve orifice 304 on the housing 202. Similarly, when the vehicle undergoes intense motion (such as acceleration or rapid turning), significant fluid motion (such as sloshing or swirling) may act on the float 206 and other floating components, causing the float and other floating components to shift from their aligned positions relative to the valve orifice 304.

[0062] Accordingly, to help align or center the float 206 relative to the housing 202 and prevent unwanted displacement in its position, alignment and / or guiding features may be provided that can guide the movement of the float 206 as it translates within the housing 202. In this way, the correct positioning of the flap 1014 relative to the valve orifice 304 (shown by the schematic ring 1002) can be ensured, thus reducing the likelihood of fluid leakage (especially due to misalignment).

[0063] Although the term "alignment feature" may be used to describe the embodiments disclosed herein, other terms suitable for guiding movement or alignment positions may be used interchangeably, such as guiding features.

[0064] In some embodiments, one or more float guides 1004, 1006 may be provided in the housing 202. By way of example and not limitation, the float guides 1004, 1006 may be disposed at the outer wall 308 of the housing 202 and extend inwardly toward the float 206. Correspondingly, one or more float guide passages 1008, 1010 may be constructed in the outer surface 312 of the float 206 and configured to engage the float guides 1004, 1006 of the housing 202. However, in such a design, the hydrodynamic and / or the effect of the forces acting on the float 206 (such as swirling fluid motion) may be amplified because the cross-sectional area of the passages 1008, 1010 for receiving the fluid flow is relatively large and / or because the passages 1008, 1010 are located in an outer radial position, thus unfavorably providing a large moment arm for the resultant force on the float 206.

[0065] Figures 11 to 12 Another embodiment of the float 206 and the housing 202 is shown, both of which may include one or more alignment features similar to those described above. In a particular embodiment, one or more float guides 1102 may be provided at the inner wall 306 of the housing 202 and point outwardly toward the float 206. By way of example and not limitation, in the configuration as depicted, four float guides 1102 may be provided, which may be evenly spaced from each other in the radial direction on the inner wall 306 of the housing 202. Correspondingly, the float 206 may also be configured to have one or more (e.g., four as shown) float guide passages 1104 at the inner surface 310 of the float 206, which may be positioned at equal distances from each other in the radial direction and configured to cooperate with the float guides 1102 of the housing 202. As further depicted, in a particular embodiment, the float guides 1102 may optionally be constructed with a protrusion or rounded projection 1106, for example, at the end portion of the float guides 1102. This may be at Figure 12is more clearly observed that in Figure 12 the float guide 1102 and the float guide passage 1104 are enlarged to better show details. When extending into the float guide passage 1104, the protrusion 1106 can contact the float guide passage 1104 or at least reduce the gap between the float guide 1102 and the float guide passage 1104 to further limit the freedom of lateral movement of the float 206 relative to the housing 202. Of course, without departing from the scope of the present disclosure, the protrusion 1106 can be different from the shown shape.

[0066] Although described in this specific manner, those skilled in the art should understand that other suitable numbers (e.g., two, three, five, six, etc.) and arrangements of these alignment features (e.g., float guides and float guide passages) can also be used to perform the desired functions of the present disclosure. For example, in some embodiments, the number of float guides can be increased to allow for closer alignment due to the more uniform and distributed constraining action of the float guides on the float, thereby limiting unwanted displacement and movement during the expected longitudinal translation of the float. Additionally, a greater number of float guide passages can achieve a smaller cross-sectional area required for movement guidance and constraint. These smaller cross-sectional areas can reduce the surface area inside the float available for the action of fluid movement. Moreover, the position of the float guide passage at the inner radius of the float can reduce the moment arm length for the action of the fluid force impinging on the float. This restricted relative displacement, force, and movement of the float can further contribute to improving the alignment of the flap with the valve orifice, thereby reducing fuel leakage and enhancing the sealing ability.

[0067] Figure 13 shows yet another embodiment of the alignment features of the float 206 and the housing 202. This configuration can be related to that referred to above with reference to Figures 11 to 12The described configurations are similar in that four sets of float guides and float guide passages are provided correspondingly along the radial direction on the inner wall 306 of the housing 202 and the inner surface 310 of the float 206. Additionally, one or more additional float guides 1302 may be provided at the outer wall 308 of the housing 202. The outer surface 312 of the float 206 may also be configured with one or more additional float guide passages 1304 to receive the associated float guides 1302 therein. By way of example and not limitation, the additional float guides 1302 and float guide passages 1304 may have a smaller cross-sectional area to minimize the hydraulic pressure acting on the float 206. In a particular implementation, one or more vapor release cuts 1306 may also be provided on the outer perimeter or outer surface 312 of the float 206, which may help optimize the flow of fuel vapor through the gap between the float 206 and the housing 202. Again, while described and depicted in this particular manner, those skilled in the art will understand that other suitable configurations of the float and housing may be employed. For example, the number of additional float guides, float guide passages, and vapor release cuts may be set differently from those shown without departing from the scope of the present disclosure.

[0068] Figure 14 An isolated view of the float 206 (with the flap 204 omitted) is shown from another perspective, in which the alignment features (i.e., the float guide passages 1104, the additional float guide passages 1304) and the vapor release cuts 1306 can be more clearly observed. As can be seen, the float guide passages 1104 may have a relatively large longitudinal length along the y-axis height of the float 206 (i.e., pointing into the page as shown in the figure). Similarly, although not visible from this angle, the additional float guide passages 1304 may also span the entire height of the float 206 along the y-axis. In a particular implementation, on the other hand, the length of the vapor release cuts 1306 may be much smaller than the height of the float 206, for example to facilitate the escape of vapor while limiting the hydraulic pressure impinging on the float 206 to a lesser extent.

[0069] Similarly, Figure 15 The float guides 1102 of the housing 202 are shown from a different perspective. In a particular implementation, the length of the float guides 1102 may be substantially equal to the length of the float guide passages 1104 such that when inserted, the float guides 1102 may extend throughout the float guide passages 1104 (e.g., along the y-axis). For example, this may provide better guidance and restraint of the movement of the float 206 and prevent misalignment of the float 206 and its various components (such as the flap 204) as they translate up and down within the housing 202 in response to changes in the liquid fuel level.

[0070] The above dimensions and configurations of the alignment features and / or other features (such as the vapor release cutout) are provided only as examples and are not intended to limit the scope of the present disclosure. The present disclosure can also contemplate other suitable dimensions and configurations for performing the desired functions.

[0071] As already explained above, the misalignment of the float relative to the housing, and more specifically the misalignment of the flap relative to the valve orifice, can affect the sealing performance and result in undesired fluid leakage. In the specific embodiments, as previously referenced Figures 7 to 8 and as discussed, the flap 204 can be connected to the float 206 by a flap guide 702 disposed at the top surface of the float 206. By way of example and not limitation, the flap guide 702 can allow the flap 204 to lift and / or tilt relative to the upper surface of the float 206. As another example, the flap guide 702 can additionally limit the extent of the maximum possible lift and / or maximum possible tilt of the flap 204 relative to the float 206.

[0072] Figures 16 to 22 Several embodiments showing different combinations of flaps and flap guides are shown. Due to the unexpected relative movement between the flap and the float, the flap position can exhibit undesired deviations in the form of relative translation, offset, and / or tilt (e.g., in the lateral direction). For example, since the flap is allowed to be lifted open, e.g., to balance the pressure across the float, when the flap falls back into place, the flap may sometimes not return to its proper relative position and alignment with the valve orifice, which can be the result of, for example, a poor engagement between the flap and the flap guide.

[0073] For example, in the embodiment as shown in Figure 16 (and Figure 10 ), the cross-section of the flap guide 1012 can narrow or taper towards the side of the flap guide 1012 facing the flap 1014 (as seen more clearly in the top view of Figure 10 ). In such a tapered configuration, the flap 1014 may experience excessive displacement or movement relative to the flap guide 1012, e.g., a tendency to twist or rotate about the flap guide 1012 (e.g., as seen in the top view, about an axis parallel to the longitudinal direction of the float 206).

[0074] Figure 17 and Figure 18A first configuration of the flap guide 1702 and the flap 1802 in accordance with the present disclosure is shown respectively. In a specific embodiment, the flap guide 1702 may take the form of a hinge member that may be permanently connected to the upper surface of the float 206 at both of its ends, for example, and form a passage 1704. In a specific embodiment, the flap 1802 may include a post 1804. By way of example and not limitation, one end of the post 1804 may be connected to the base frame 1806 of the flap 1802 in a cantilever manner such that, during operation, the flap 1802 may rotate about the post 1804. The other end of the post 1804 may be configured to have an enlarged protrusion 1808. In a specific embodiment, the post 1804 may be split along its length. Configured in this way, for example, the post 1804 may be temporarily compressed for assembly and inserted into the passage 1704 of the flap guide 1702. When released, the post 1804 may hold the flap 1802 in place relative to the flap guide 1702 by its enlarged protrusion 1808 while allowing the flap 1802 to be opened and / or closed and restricting its lateral movement. Further, in a specific embodiment, one or both sides of the flap guide 1702 may be provided with notches to form stops 1706 for limiting the degree of opening of the flap 1802 to a desired level, thereby avoiding over-rotation of the flap 1802.

[0075] Figures 19 to 20A second configuration of the flap guide 1902 and the flap 2002 in accordance with the present disclosure is shown. In a specific embodiment, the flap guide 1902 may take the form of a hinge member, which may be permanently connected to the upper surface of the float 206 at one of its ends, while the other (free) end 1906 is located near the upper surface of the float 206 but is not rigidly connected to the upper surface of the float. In a specific embodiment, the flap guide 1702 may form a passage 1904 therethrough, which may be similar to the passage described above for engaging with the flap 2002. In a specific embodiment, the flap 2002 may include one or more posts, such as posts 2004, 2006, which may be connected to the base frame 2008 of the flap 2002. By way of example and not limitation, the respective ends of the posts 2004, 2006 may be spaced apart from each other by a small distance. In this way, the posts 2004, 2006 may be briefly separated when the component is stressed for assembling the flap 2002 with the flap guide 1902, and then released back to their initial positions when they enter the passage 1904 to hold the flap 2002 in place while allowing the flap 2002 to be opened and / or closed and restricting its lateral movement. Alternatively, although not shown, a single post may be provided, which may be snapped into the passage 1904 through the gap between the free end 1906 and the top surface of the float 206 during assembly to rotatably fix the flap 2002 to the flap guide 1902. Similarly, in a specific embodiment, notches may be provided on one or both sides of the flap guide 1902 to form a stop 1908 to limit the degree of opening of the flap 2002 to a desired level, thereby preventing the flap 2002 from opening further beyond the stop 1908.

[0076] Figures 21 to 22A third configuration of the flap guide 2102 and the flap 2202 in accordance with the present disclosure is shown. In a specific embodiment, the flap guide 2102 can be formed as a rib that protrudes outwardly from the top surface of the float 206. For example, the flap guide 2102 can have a wide cross-section, for example, at its base portion. By way of example and not limitation, the cross-section of the flap guide 2102 can generally be shaped as a quadrilateral, a rectangle, a rounded rectangle, etc. The large and widely distributed cross-sectional area of the ribbed flap guide 2102 can provide the benefit of significantly restricting the lateral displacement and / or rotation of the flap 2202 relative to the valve orifice of the housing, for example. In addition, the restricted displacement and accurate alignment relative to the valve orifice can thus help reduce fuel leakage, improve sealing, and flap re-opening ability. In a specific embodiment, the flap guide 2102 can be configured to have a notch 2104 near its top to allow the flap 2202 to rise and / or tilt relative to the upper surface of the float 206 while restricting the maximum possible range of motion of the flap 2202 when it rises and / or tilts. In a specific embodiment, the flap 2202 can include connecting ends 2204, 2206 that extend from the frame 2212 and engage the flap guide 2102, for example, by fitting or snapping onto the base of the flap guide 2102. As a non-limiting example, the connecting ends 2204, 2206 can be briefly separated when the component is stressed to assemble the flap 2202 with the flap guide 2102 and then released to substantially return to their initial positions and hold the flap 2202 in place while allowing the flap 2202 to be opened and / or closed. In addition, in a specific embodiment, relief cuts 2208, 2210 can be provided at the bases of the connecting ends 2204, 2206, respectively. For example, when the connecting ends 2204, 2206 are temporarily separated for assembly, the relief cuts 2208, 2210 can reduce the stress applied to the material, which can reduce the permanent deformation of the flap 2202 and thus improve the alignment performance of the flap 2202 (e.g., relative to the valve orifice of the housing), as well as the durability and reliability of the entire component over its entire working life. In addition, in the case of restricted displacement and precise alignment, the features of the present invention can also help reduce fuel leakage and improve the sealing and re-opening ability of the flap.

[0077] Figure 23 The flap 2202 and the flap guide 2102 are shown in an assembled configuration, where the flap 2202 is shown in its closed state. As already explained, when closed, the flap 2202 can rest well on top of the upper surface of the float 206 and cover a fluid passage (not visible in the figure) that extends inside the body of the float 206, thereby prohibiting fluid communication through the float 206 in the housing to the volume above the float 206.

[0078] In addition, for illustrative purposes only, Figures 24 to 25 some exemplary dimensions of the flap 2202 and the flap guide 2102 are shown. In a specific embodiment, the dimensions of the frame 2212 of the flap 2202 (which can be made of a relatively rigid material, for example) can generally be designed to have a length L of about 13.17 mm 1 and a width W of about 10.00 mm 1 . In a specific embodiment, the deformable flap 2402 that arches above the frame 2212 can generally have a length L of about 7.39 mm 2 . In a specific embodiment, the flap guide 2102 can be inclined relative to the top surface of the float 206. As an example and not a limitation, the front side of the flap guide 2102 (i.e., the side facing the main part of the flap 2202) can be inclined at an angle θ of about 76.7 degrees 1 , while the rear side of the flap guide 2102 (i.e., the side that engages with the connecting ends 2204, 2206) can be inclined at an angle θ of about 82.5 degrees 2 . In a specific embodiment, the notch 2104 can be inclined relative to the top surface of the float 206 at an angle θ of about 13 degrees, for example 3 . In a specific embodiment, the base portion of the flap guide 2102 can have a length L of about 1.81 mm 3 .

[0079] Those skilled in the art should understand that the above dimensions are provided for illustrative purposes only and are not necessarily required. Although the present disclosure describes the flap and the flap guide as having specific dimensions in a specific manner, the present disclosure contemplates that the flap and the flap guide can have any suitable dimensions in any suitable manner. In addition, the present disclosure not only contemplates the combination of features described above and described in the drawings, but also contemplates any other suitable combination of features. For example, the flap 1802 described with reference to Figure 18 can be applied to the flap guide 1902 described with reference to Figure 19 . As another example, the flap 2002 described with reference to Figure 20 can be applied to the flap guide 1702 described with reference to Figure 17 . In addition, the embodiments disclosed herein are only examples, and the scope of the present disclosure is not limited thereto. The specific embodiments can include all, some, or none of the components, elements, features, functions, and operations of the embodiments disclosed above.

[0080] As used herein, "or" is inclusive and not exclusive, unless explicitly indicated otherwise or indicated by context. Thus, as used herein, "A or B" means "A, B, or both", unless explicitly indicated otherwise or indicated by context. Further, "and" means both conjointly and separately, unless explicitly indicated otherwise or indicated by context. Thus, as used herein, "A and B" means "A and B, conjointly or separately", unless explicitly indicated otherwise or indicated by context.

[0081] The scope of the present disclosure includes all changes, substitutions, variations, alterations, and modifications to the exemplary embodiments described or shown herein that would be understood by a person of ordinary skill in the art. The scope of the present disclosure is not limited to the exemplary embodiments described or shown herein. Further, although the present disclosure describes and shows various embodiments herein as including particular components, elements, features, functions, operations, or steps, it should be understood by a person of ordinary skill in the art that any one of these embodiments may include any combination or arrangement of any of the components, elements, features, functions, operations, or steps described or shown anywhere herein. Additionally, the recitation in the appended claims of a device or system or a component of a device or system that is adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function covers that device, system, or component, whether or not that particular function is activated, turned on, or unlocked, so long as that device, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative. Further, although the present disclosure describes or shows particular embodiments as providing particular advantages, the particular embodiments may not provide those advantages, may not provide some of those advantages, or may not provide all of those advantages.

Claims

1. An exhaust valve assembly for use with a fuel tank, the exhaust valve assembly comprises: a housing having an outer wall structure and an inner wall structure, defining a chamber therebetween; a float located within the chamber and configured to translate relative to the housing along an axis, the float having an aperture extending along the axis, wherein the inner wall structure of the housing is disposed within the aperture of the float, and wherein an inner surface of the aperture of the float is positioned to face the inner wall structure of the housing; one or more guiding features located on the inner surface of the aperture of the float; and one or more mating guiding features located on the inner wall structure of the housing and configured to cooperate with the one or more guiding features; wherein the one or more guiding features and the one or more mating guiding features cooperate to guide translation of the float relative to the housing along the axis and to restrict rotation of the float about the axis.

2. The exhaust valve assembly according to claim 1, wherein the one or more guiding features extend substantially along the axis throughout the entire length of the float.

3. The exhaust valve assembly according to claim 1, wherein the length of the one or more guiding features is substantially equal to the length of the one or more mating guiding features.

4. The exhaust valve assembly according to claim 1, wherein the one or more guiding features are configured to guide a passageway.

5. The exhaust valve assembly according to claim 4, wherein the one or more mating guiding features are configured as guides insertable into the guiding passageway.

6. The exhaust valve assembly according to claim 1, wherein the one or more guiding features are uniformly distributed in a radial direction on the inner surface of the aperture of the float.

7. The exhaust valve assembly according to claim 1, wherein the one or more mating guiding features are uniformly distributed in a radial direction on the inner wall structure of the housing.

8. The exhaust valve assembly according to claim 1, wherein the one or more mating guiding features include protrusions.

9. The exhaust valve assembly according to claim 1, wherein four of the guiding features and four of the mating guiding features are provided.

10. The exhaust valve assembly according to claim 1, further comprises: one or more additional guiding features located on an outer surface of the float; and one or more additional mating guiding features located on the outer wall structure of the housing and configured to cooperate with the one or more additional guiding features.

11. An exhaust valve assembly, comprises: a housing having an outer wall structure, an inner wall structure, and a valve aperture, defining a chamber therebetween; a float located inside the chamber and configured to translate relative to the housing along an axis; a flap disposed at an upper surface of the float and positioned to be aligned with the valve aperture; and a flap guide located at the upper surface and configured to engage the flap; Wherein, the flap guide enables the flap to open and close and keeps the flap aligned with the valve orifice.

12. The exhaust valve assembly according to claim 11, wherein, the flap guide is a hinge member, and two end portions of the hinge member are respectively connected to the upper surface of the float.

13. The exhaust valve assembly according to claim 11, wherein, the flap guide is a hinge member, one end portion of the hinge member is connected to the upper surface of the float and the other end portion of the hinge member is not connected to the upper surface of the float.

14. The exhaust valve assembly according to claim 11, wherein, the flap guide includes a passage.

15. The exhaust valve assembly according to claim 14, wherein, the flap includes one or more posts, and the one or more posts are rotatably inserted into the passage of the flap guide.

16. The exhaust valve assembly according to claim 11, wherein, the flap guide includes a stop portion configured to limit the opening degree of the flap.

17. The exhaust valve assembly according to claim 11, wherein, the flap guide is a rib.

18. The exhaust valve assembly according to claim 11, wherein, the flap guide includes a base portion having a large cross-sectional area to limit the lateral movement of the flap.

19. The exhaust valve assembly according to claim 18, wherein, the cross-sectional area of the base portion is shaped as a quadrilateral.

20. The exhaust valve assembly according to claim 11, wherein, the flap includes one or more connecting end portions.

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