Two-stage pressure relief fuel tank isolation valve

Abstract

A valve assembly (130) for a fuel tank is disclosed, featuring a valve housing (132) with an inlet (133), outlet (144), and an internal chamber. A cage (171) is positioned within this chamber, housing a movable sealing element (168) with a disk (148) at its lower end. This disk includes apertures (210) for vapor passage. An outer seal (174) is coupled to the bottom of the cage. Below the disk is an over pressure release (OPR) seal (142), to which an inner seal component (443) with a seal lip 450 is attached. The inner seal component is configured to seal a vapor passage between the disk and the OPR seal when these components are pressed together. Conversely, the seal lip guides vapor flow toward this passage when the disk and OPR seal separate.

Description

Two-Stage Pressure Relief Fuel Tank Isolation ValveTECHNICAL FIELD

[0001] This disclosure generally relates to a valve assembly used in a fuel emission control system to regulate fuel vapor flow and pressure.BACKGROUND

[0002] A vehicle’s fuel system is designed to manage both liquid fuel delivery and fuel vapor containment in accordance with evaporative emissions regulations. The fuel system of certain types of vehicles, such as hybrid vehicles, includes a fuel tank for storing liquid fuel, a valve assembly for controlling the vapor flow path from the tank, a vapor recovery canister for capturing fuel vapors that flow through the valve assembly, and a vehicle engine that consumes the fuel vapors released from the vapor recovery canister.

[0003] The valve assembly, which may be referred to as a fuel tank isolation valve, is designed to reduce vapor emissions from a vehicle’s fuel system and prevent undesirable operational issues. Integrated into the fuel tank assembly, the valve assembly allows fuel vapors to be temporarily stored within the tank itself, rather than routing them immediately to the vapor recovery canister. This internal trapping mechanism delays vapor flow and prevents premature loading of the canister, particularly during extended periods of vehicle inactivity or high-temperature conditions.

[0004] The valve assembly includes mechanisms to open or close to selectively permit fuel vapor to pass through as needed. For example, before a refueling event, the valve assembly may open to allow displaced vapors to be routed to the recovery canister rather than venting directly to the atmosphere. Doing so also depressurizes the fuel tank, which in turn prevents corking due to the rapid rise in pressure caused by incoming fuel. During vehicle operation, the valve assembly works in coordination with purge valves to regulate when and how vapors are purged from the canister and introduced into the engine intake for combustion. When closed, the valve assembly helps prevent unintended vapor loss and maintains pressure within the tank for onboard diagnostics and leak detection.SUMMARY

[0005] Embodiments described herein are directed to a fuel tank isolation valve assembly. Certain features of the valve assembly are summarized by the clauses below.

[0006] Clause 1. A valve assembly for a fuel tank, the valve assembly comprising: a valve housing having an inlet, an outlet, and a chamber between the inlet and outlet; a cage disposed within the chamber of the valve housing, the cage comprising an upper opening and a bottom opening opposite the upper opening; an outer seal coupled to the bottom opening of the cage; a movable sealing element that extends into the cage through the upper opening, the movable sealing element having an upper end and a lower end opposite to the upper end, the upper end of the movable sealing element being configured to be coupled to an actuator, and the lower end of the movable sealing element comprising a disk that is disposed within the cage and above the outer seal coupled to the bottom opening of the cage, the disk having one or more apertures for allowing vapor to pass through the disk; an over pressure release (OPR) seal disposed below the disk of the movable sealing element; and an inner seal component coupled to the OPR seal, the inner seal component comprising a seal lip; wherein the inner seal component is configured to seal a first vapor passage between the disk and the OPR seal when the disk and the OPR seal are pressed against each other, wherein the seal lip is configured to guide vapor flow toward the first vapor passage when the disk and the OPR seal are separated from each other to open the first vapor passage.

[0007] Clause 2. The valve assembly of any one of the preceding Clauses, wherein when the disk and the OPR seal are pressed against each other, the seal lip surrounds the one or more apertures of the disk.

[0008] Clause 3. The valve assembly of any one of the preceding Clauses, wherein the seal lip extends from a top surface of the OPR seal toward the disk.

[0009] Clause 4. The valve assembly of Clause 3, wherein the seal lip is curved upward toward the disk and inward toward an axis of the movable sealing element.

[0010] Clause 5. The valve assembly of any one of the preceding Clauses, wherein the disk comprises (i) a first interface surface configured to interface the outer seal and (ii) a second interface surface configured to interface the seal lip of the inner seal.

[0011] Clause 6. The valve assembly of Clause 5, wherein the second interface surface is substantially flat.

[0012] Clause 7. The valve assembly of Clause 5, wherein the second interface surface includes an annular ridge.

[0013] Clause 8. The valve assembly of Clause 7, wherein the annular ridge includes a surface that slants outward and downward toward the OPR seal.

[0014] Clause 9. The valve assembly of any one of the preceding Clauses, wherein the movable sealing element comprises a stem, and the OPR seal comprises a bore for receiving the stem.

[0015] Clause 10. The valve assembly of Clause 9, wherein the stem and the bore have tapered surfaces.

[0016] Clause 11. The valve assembly of Clause 9 or Clause 10, wherein when the disk and the OPR seal are pressed against each other, a clearance gap exists between a distal end of the stem and an interior surface of the bore.

[0017] Clause 12. A valve assembly for a fuel tank, the valve assembly comprising: a valve housing having an inlet, an outlet, and a chamber between the inlet and outlet; a cage disposed within the chamber of the valve housing, the cage comprising an upper opening and a bottom opening opposite the upper opening; an outer seal coupled to the bottom opening of the cage; a movable sealing element that extends into the cage through the upper opening, the movable sealing element having an upper end and a lower end opposite to the upper end, the upper end of the movable sealing element being configured to be coupled to an actuator, and the lower end of the movable sealing element comprising a disk that is disposed within the cage and above the outer seal coupled to the bottom opening of the cage, the disk having one or more apertures for allowing vapor to pass through the disk; an over pressure release (OPR) seal disposed below the disk of the movable sealing element; and an inner seal component coupled to the disk, the inner seal component comprising a seal lip; wherein the inner seal component is configured to seal a first vapor passage between the disk and the OPR seal when the disk and the OPR seal are pressed against each other, wherein the seal lip is configured to guide vapor flow toward the first vapor passage when the disk and the OPR seal are separated from each other to open the first vapor passage.

[0018] Clause 13. The valve assembly of Clause 12, wherein the seal lip surrounds the one or more apertures of the disk.

[0019] Clause 14. The valve assembly of any one of Clauses 12 or 13, wherein the seal lip extends from a bottom surface of the disk toward the OPR seal.

[0020] Clause 15. The valve assembly of Clause 14, wherein the seal lip is curved downward toward the OPR seal and outward.

[0021] Clause 16. The valve assembly of any one of Clauses 12-15, wherein the inner seal component further comprises an interface surface configured to interface with the outer seal.

[0022] Clause 17. The valve assembly of Clause 16, wherein the interface surface is substantially flat.

[0023] Clause 18. The valve assembly of any one of Clauses 12-17, wherein an upper surface of the OPR seal comprises one or more flow guides for guiding vapor flow.

[0024] Clause 19. The valve assembly of any one of Clauses 12-18, wherein the movable sealing element comprises a stem, and the OPR seal comprises a bore for receiving the stem.

[0025] Clause 20. The valve assembly of Clause 19, wherein the stem and the bore have tapered surfaces.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Embodiments in accordance with this disclosure will now be described by reference to the accompanying drawings.

[0027] FIG. 1A illustrates the exterior view of a fuel tank isolation valve assembly with a 180- degree inlet / outlet configuration, in accordance with particular embodiments.

[0028] FIG. IB illustrates a cross-sectional view of the fuel tank isolation valve assembly shown in FIG. 1A, in accordance with particular embodiments.

[0029] FIGS. 2-3 illustrate close-up cross-sectional views of the valve assembly of FIG. IB.

[0030] FIG. 4 illustrates a valve assembly in accordance with another embodiment.

[0031] FIGS. 5-8 illustrate various open states of a valve assembly, where FIG. 5 shows an over pressure release state, FIG. 6 shows the first stage in a two-stage opening mechanism, and FIGS. 7-8 show the second stage in the two-stage opening mechanism.

[0032] FIG. 9 illustrates a valve assembly in accordance with a further embodiment.

[0033] FIG. 10 illustrates the exterior view of a fuel tank isolation valve assembly with a 90- degree inlet / outlet configuration, in accordance with particular embodiments.

[0034] FIG. 11 illustrates a cross-sectional view of the fuel tank isolation valve assembly shown in FIG. 10, in accordance with particular embodiments.

[0035] FIGS. 12A and 12B illustrate exploded and perspective views of certain components of a valve assembly.DESCRIPTION OF EXAMPLE EMBODIMENTS

[0036] In hybrid vehicles, the fuel tank is typically maintained as a sealed or closed system in order to reduce evaporative emissions. A valve assembly may be used to selectively isolate the fuel tank from the rest of the vehicle’s evaporative emission control system, including the engine and vapor recovery canister. The valve assembly controls the venting of fuel vapors from the fuel tank to a canister that temporarily stores the vapors and is periodically purged during engine operation.

[0037] Such a valve assembly plays an important role in managing internal fuel tank pressure by opening or closing vapor flow paths in response to commands from the vehicle’s controller. In certain driving scenarios — such as when the hybrid vehicle is operating in electric-only mode — the fuel tank may remain isolated for extended periods, during which vapor pressure may build up. Even when the vehicle is off, ambient temperature may cause pressure to build up within the fuel tank. To prevent excessive pressure accumulation, the valve assembly may either actively or passively open to release pressure from the fuel tank and allow fuel vapor to escape into the recovery canister.

[0038] The valve assembly may also be activated during refueling to improve the refueling operation. In some vehicle architectures, the driver initiates refueling by pressing a button, which signals the controller to open the valve assembly and vent pressure from the sealed fuel tank to the canister. This pre-venting helps avoid “corking” conditions and allows for smooth fuel flow during refueling. The FTIV may remain open throughout the refueling process to maintain appropriate pressure within the tank.

[0039] In certain embodiments, the valve assembly may support one or more pressure management functions, such as Over Vacuum Release (OVR) and Over Pressure Release (OPR).These functions are implemented to maintain the fuel tank pressure within a desired range and to protect against both excessive vacuum and over-pressurization conditions that may occur due to changes in temperature, fuel volume, or driving mode transitions. In certain embodiments, the OVR function may be implemented using a two-stage opening mechanism, designed to enable a controlled and gradual pressure equalization process during depressurization events. For instance, during a fuel tank depressurization command — such as when the user initiates refueling — the vehicle’s controller may instruct the valve assembly to release built-up pressure in a staged manner. In certain embodiments, the OPR function may be implemented as a passive mechanical relief of excessive fuel tank pressure, ensuring safety and regulatory compliance. The OPR mechanism is designed to automatically vent pressure from the fuel tank to a vapor recovery canister when internal pressure exceeds a predefined threshold. Both of these functions will be described in further detail below

[0040] As vehicle manufacturers face increasing pressure to reduce cost, improve fuel efficiency, and meet stricter packaging and emissions requirements, the size, weight, and complexity of individual components, such as the fuel tank isolation valve assembly, become increasingly important. Conventional designs with separate valve actuation and passive venting functions result in bulkier form factors, increased part counts, and added assembly complexity. These drawbacks contribute to greater material usage, higher manufacturing and integration costs, and challenges in meeting space constraints, particularly in densely packaged hybrid vehicle platforms where available underbody or tank-mounting space is limited.

[0041] In contrast, the embodiments described herein incorporate an inline valve actuation system in which the actuation mechanism and passive venting mechanism are integrated and aligned within the fuel vapor flow path. This configuration offers several key advantages, including reduced component count, elimination of offset mechanical linkages or support structures, and improved packaging efficiency. For example, unlike conventional designs that require a separate OPR core, the present inline design significantly reduces weight and mass by eliminating the OPR core and its associated components (e.g., two O-rings and an OPR cap). While the OPR seal remains necessary, it is now positioned inline with the solenoid and OVR assembly, as described in greater detail below.

[0042] The solenoid used in the inline fuel tank isolation valve contributes to a more compact and cost-effective design compared to conventional configurations. In this context, a "crimp can" refers to a metal enclosure — typically steel — that is mechanically deformed to securely contain the internal components of the solenoid assembly. It provides mechanical integrity, environmental sealing, and structural support for the coil, plunger, and related components. In the embodiments described herein, the crimp can has been redesigned as an over-molded component integrated into the solenoid assembly, resulting in a smaller and more streamlined structure. Furthermore, a redesigned magnetic flux circuit enables a reduction in the amount of copper wire used, while maintaining the same electromagnetic force output as traditional solenoid designs.

[0043] Testing has demonstrated that a valve assembly incorporating the inline actuation architecture described herein can deliver substantial performance and manufacturing benefits. Specifically, the design achieves over a 27% reduction in weight — contributing to improved vehicle fuel efficiency and lower emissions; more than a 39% reduction in physical volume — facilitating easier integration into constrained installation spaces or smaller fuel tank modules; and over a 24% reduction in component count — leading to lower manufacturing costs, increased reliability, and streamlined assembly and quality control. Collectively, these improvements enhance both the manufacturability and operational performance of the valve assembly, while also supporting broader vehicle-level objectives such as emissions compliance, system durability, cost efficiency, and packaging flexibility. As such, the integrated inline valve actuation system represents a significant advancement over conventional designs in both technical capability and commercial viability.

[0044] FIGS. 1A, IB, 2, and 3 depict a valve assembly 130 configured to control the flow path between a fuel tank and a recovery canister, in accordance with certain embodiments of this disclosure. In the illustrated embodiment, the valve assembly includes a housing 132 with an inlet 133 configured to be connected to the fuel tank, and an outlet 134 configured to be connected to the recovery canister. The inlet 133 and outlet 134 are arranged generally parallel and opposite to one another, which is why the valve assembly 130 may be referred to as a 180-degree housing. Alternatively, as shown in FIG. 11 (described in greater detail below), the valve assembly may employ a 90-degree housing, in which the inlet 1033 and outlet 1034 are oriented generallyperpendicular to each other. The inline mechanisms that provide OVR and OPR functionality, as described herein, are compatible with both housing configurations.

[0045] In certain embodiments, the valve assembly 130 achieves pressure regulation (e.g., OVR functionality) through a two-stage opening mechanism, with each stage providing a distinct degree of valve opening to optimize the pressure release process. Specifically, the first stage creates a smaller fluid passage, while the second stage opens a larger passage, enabling a pressure relief profile that is both controlled and efficient — gradual at first, yet capable of rapid depressurization when needed. This two-stage mechanism helps reduce peak flow rates from the fuel tank at higher internal pressures and increases flow capacity when the pressure is relatively lower. For instance, the two-stage opening may be triggered during a vehicle refueling event, where the fuel tank — previously sealed in an isolated state — requires controlled depressurization prior to refueling.

[0046] In certain embodiments, the two-stage OVR release process is actuated by a solenoid assembly 160 positioned within the housing 132. The solenoid assembly 160 is configured to receive electrical power and respond to control signals to actuate valve movement. It may include an armature 162, a solenoid spring 164, and a coil 166. The armature 162 is designed to move axially along its longitudinal axis. As shown in FIG. IB, the solenoid spring 164 is positioned between the outer end of the solenoid assembly — through which the armature 162 extends — and a movable sealing element 168 (e.g., a poppet) attached to the distal end of the armature. While this embodiment shows a solenoid being used as the actuation device, this disclosure contemplates other types of actuation devices for extending and retracting the movable sealing element. For example, instead of a solenoid, the actuator may be an electro-mechanical actuator (e.g., a stepper motor and leadscrew), a pneumatic actuator, a hydraulic actuator, or a piezoelectric actuator.

[0047] In the default, unpowered state, the solenoid spring 164 applies a force that pushes the movable sealing element 168 away from the solenoid 160, thereby extending the armature 162 outward mechanically. When the coil 166 is energized, it generates a magnetic field that pulls the armature 162 upward into the solenoid, overcoming the spring force until the armature 162 is fully retracted, as limited by the solenoid’s internal structure. When power is removed, the spring force once again biases the armature 162 outward until it reaches its fully extended position. This spring-biased actuation mechanism enables reliable passive return and supports controlled, staged valve opening under varying pressure conditions.

[0048] As noted above, the armature 162 is coupled to a movable sealing element 168 (e.g., a poppet), which moves in unison with the armature along its longitudinal axis. In general, when the armature 162 is in its fully extended position, the movable sealing element 168 closes an orifice in the housing 132, thereby sealing the flow path between the fuel tank and the vapor recovery canister. Conversely, when the armature 162 is retracted, the movable sealing element 168 moves to an open position, unsealing the orifice and allowing vapor to flow freely between the fuel tank and the recovery canister. Due to other factors such as pressurization, vapor may also be allowed to vent without energizing the solenoid 160. Details of these mechanisms will be described further below.

[0049] In certain embodiments, the valve assembly 130 includes various two-stage opening structures arranged inline within the housing 132. These structures may include, for example, a cage 171 and a cage spring 172. The cage 171 is generally cup-shaped and dimensioned to fit within a chamber defined inside the housing 132. Its upper opening is configured to receive the movable sealing element 168, which is coupled to the solenoid armature 162. In some embodiments, the distal edges of the upper opening are flared or bent outward to form a spring seat for the cage spring 172. The sidewalls of the cage 171 may include one or more side openings large enough to allow vapor to pass freely, ensuring minimal flow restriction. The bottom of the cage 171, opposite the upper opening, may include a bottom opening. The bottom opening may be partially enclosed with inward-bent edges of the cage 171 that form a seat for the movable sealing element 168. As described in more detail below, when the movable sealing element 168 lifts away from this seat — without moving the cage itself — vapor is allowed to flow through the bottom opening of the cage 171, constituting the first stage of the two-stage release process. In the second stage, the entire cage 171 moves upward, permitting additional vapor flow underneath the cage and through the outlet 134, thereby significantly increasing flow capacity

[0050] Movement of the cage 171 is governed by the interaction between the cage spring 172 and the solenoid armature 162, which is mechanically coupled to the upper end of the movable sealing element 168. The cage spring 172 may have a conical shape, as illustrated, though other geometries may also be suitable. During the second stage of the opening process (described infurther detail below), the cage 171 may function as a spring guide to help stabilize the cage spring 172. The upper end of the cage spring 172 engages an outwardly bent flange at the top of the cage171, applying upward force. The lower end of the spring rests on one or more support features formed along the inner sidewall of the housing 132. In the embodiment shown in FIG. 1, these support structures are positioned approximately co-planar with at least a portion of the inlet 133. This arrangement allows the cage spring 172 to exert an upward bias on the cage 171, urging it toward the solenoid 160 and enabling controlled two-stage actuation.

[0051] Despite the upward bias applied by the cage spring 172, the cage 171 may default to a closed position at the bottom of the valve assembly 130. This is due to the downward force exerted by the movable sealing element 168, which is at least partially housed within the cage and moves in tandem with the solenoid armature 162. As previously described, when the solenoid coil 166 is de-energized, the solenoid spring 164 drives the armature 162 — and consequently the movable sealing element 168 — downward toward the base of the cage 171. The sealing element presses against the inwardly bent surface at the cage’s lower opening, thereby transferring its downward force to the cage itself. Because the solenoid spring 164 exerts a greater force than the cage spring172, this interaction holds the cage in its closed position. In the absence of actuation by the solenoid or external forces (e.g., vapor pressure or vacuum), both the movable sealing element 168 and the cage 171 remain in their respective closed positions.

[0052] Starting from the default closed position, energizing the valve assembly 130 initiates a two-stage opening process. In the first stage, the energized solenoid 160 lifts the movable sealing element 168, overcoming the solenoid spring 164’s bias. This upward movement separates the movable sealing element 168 from the bottom of the cage 171, creating a small flow path. As the movable sealing element 168 rises, it may also cause the OPR seal 142, which is spring-biased by the valve spring 150 beneath it, to move upward in tandem. While this smaller flow path is open between the movable sealing element 168 and the cage 171, vapor pressure from the fuel tank acts on the top chamber within the housing 132, where the cage 171 resides. If the vapor pressure remains sufficiently high compared to the cage spring 172 force, it pushes the cage 171 downward, keeping the larger orifice — formed between the cage 171 and the housing’s interior surface — closed. However, as venting through the smaller orifice reduces pressure in the top chamber, the force exerted by the vapor decreases. Once this pressure is no longer sufficient to counteract thepreloaded cage spring 172, the spring expands, pushing the cage 171 upward to open the larger flow path. This second stage permits increased vapor flow from the fuel tank to the recovery canister after the tank pressure has dropped sufficiently

[0053] This two-stage opening process offers several key advantages. By initially opening only a small orifice, it limits peak flow rates and prevents abrupt pressure drops that could lead to noise, valve wear, or system instability. Once the pressure decreases to a safer level, the full orifice opens to accelerate vapor evacuation, thereby enhancing refueling readiness and overall system efficiency. For example, this two-stage OVR sequence may be activated during a refueling event in a hybrid vehicle. When the user presses the refueling button, the controller initiates a controlled depressurization process. Because the fuel tank may have remained sealed and isolated during extended electric-only operation, this gradual pressure release through the FTIV is essential to avoid corking or vapor blowback, ensuring smooth, compliant, and safe refueling.

[0054] Details of the sealing features are illustrated more clearly in FIG. 2. In certain embodiments, the lower end 204 of the cage 171 is coupled with an annular outer seal 174 that matches the geometry of the cage’s lower edge. For example, the cage’s lower end may be open or include one or more through openings, with the outer seal 174 attached around and covering its perimeter near these openings. When the cage 171 is in the closed position, it rests on a supporting structure 206 formed on the inner surface of the housing 132, which surrounds an opening leading to a lower chamber 208 under the cage 171 that’s connected to the outlet 134. In this position, the lower ridge of the outer seal 174 is compressed against the supporting structure 206, effectively sealing the passage between the cage 171 and the housing 132 that leads to the lower chamber 208.

[0055] In certain embodiments, the movable sealing element 168 includes a stem 202 surrounded by a disk 148. The disk 148 may be substantially perpendicular to the axis of the movable sealing element 168. The disk 148 may have any suitable shape and / or size, so long as it is large enough to cover the interior bottom opening of the cage 171 (e.g., the disk may be circular, oval, rectangular, etc.). One or more apertures 210 may be located between the stem 202 and the disk 148, permitting vapor to pass through, as illustrated by arrows 302 in FIG. 3, even when the disk 148 is in contact with the OPR seal 142. These apertures 210 are typically positioned near the center of the disk 148, allowing vapor to flow into the space between the movable sealing element 168 and the OPR seal 142, and potentially escape into the lower chamber if there is a separationbetween the movable sealing element 168 and the OPR seal 142 (e.g., due to excessive pressure). When the movable sealing element 168 contacts the cage 171, its disk 148 rests atop the upper ridge of the cage’s outer seal 174, thereby sealing the vapor passage between the cage 171 and the movable sealing element 168.

[0056] The stem 202 of the movable sealing element 168 may be received within the OPR seal 142. In certain embodiments, the OPR seal 142 has a generally inverted hat shape, with the wider portion facing upward toward the movable sealing element 168 and the narrower, conical portion extending downward. The central part of the OPR seal 142 forms a bore that receives the stem 202, enabling the OPR seal 142 to slide relative to the stem 202. As indicated by the dotted tapered lines, the interior surface of this bore tapers, starting wider at the opening and gradually narrowing through the conical portion of the OPR seal 142. Correspondingly, the stem 202 features a matching taper, beginning wider at the upper end and narrowing toward the distal end. These complementary tapers are dimensioned to allow proper alignment when the OPR seal 142 returns to its closed, sealing position. Additionally, this design accommodates fuel swell over the product’s lifetime, maintaining an effective seal.

[0057] In certain embodiments, the dimensions of the movable sealing element 168 and the bore in the OPR seal 142 are configured so that when the stem 202 is fully inserted into the bore, a clearance gap remains between the distal end of the stem 202 and the interior surface of the bore, as indicated by the dotted circle. This gap prevents interference under varying conditions and manufacturing tolerances.

[0058] In particular embodiments, the top surface of the OPR seal 142 may be integrated with an inner seal component 143. The inner seal component 143, which may be made of an elastic material (e.g., rubber), may be implemented as a snap-fit component, which can be pressed and / or glued into a corresponding receiving cavity in the OPR seal 142. In particular embodiments, the inner seal component 143, once inserted into the OPR seal 142, may have a flat portion facing upward to interface with the disk 148 of the movable sealing element 168. In particular embodiments, the bottom surface of the disk 148 may include a protruding ridge 212 that surrounds the aperture (s) 210 in the movable sealing element 168. The ridge 212 may be positioned and dimensioned so that it mates with the inner seal component 143 of the OPR seal 142 when the movable sealing element 168 abuts the OPR seal 142, thereby sealing off the vapor flow pathbetween the movable sealing element 168 and the OPR seal 142. For example, the inner seal component 143 and the ridge 212 may both have an annular geometry so that they can mate together to create a seal.

[0059] The OPR seal 142 and the inner seal component 143 may collectively form an OPR seal assembly. For example, as illustrated in FIGs. 1-3, the inner seal component 143 may be overmolded onto or otherwise secured to the upper surface of the OPR seal 142. In an alternative embodiment, the inner seal component may instead be positioned on the lower surface of the disk 148, as further described with reference to FIG. 9, to achieve the same sealing functionality.

[0060] In certain embodiments, the OPR seal 142 may be positioned below the movable sealing element 168, as previously described. The underside of the OPR seal 142 may include a spring-retaining feature 214, such as an annular groove formed around its perimeter. This feature is configured to receive and retain a valve spring 150, which supports and biases the OPR seal 142 upward toward the movable sealing element 168. For example, the upper end of the valve spring 150 may press against the spring-retaining feature 214, applying an upward spring force. In some embodiments, the valve spring 150 may have a conical shape to help deliver appropriate sealing loads within the bore of the housing 132. The lower end 222 of the valve spring 150 may be seated in a retention feature 220 formed in the bottom of the lower chamber 208 of the housing 132. This retention feature facilitates proper assembly of the valve spring 150 and helps maintain alignment throughout the product’s operational life, even under varying environmental conditions. To minimize any impact on vapor flow, the retention feature 220 may be implemented as a step within the internal surface of the housing 132, and the lower end 222 of the valve spring 150 may include dead coils dimensioned to fill and level the space created by the step.

[0061] In certain embodiments, the OPR seal 142 and the movable sealing element 168 are not physically coupled, allowing them to separate under specific conditions — such as during an overpressure relief (OPR) event. Under normal operating conditions, however, the OPR seal 142 generally moves in tandem with the movable sealing element 168. When the movable sealing element 168 is in the closed position, the valve spring 150 biases the OPR seal 142 upward against it. As the movable sealing element 168 moves upward toward the solenoid 160 (e.g., when the solenoid is energized and retracts its armature 162), the valve spring 150 continues to exert upward force on the OPR seal 142, causing it to follow the movement.

[0062] To accommodate this upward motion, the OPR seal 142 may be dimensioned smaller than the opening at the lower end of the cage 171, allowing it to at least partially enter the cage when biased upward by the valve spring 150. Similarly, the upper portion of the valve spring 150 may be sized to pass through the same opening, ensuring continued support and upward bias of the OPR seal 142 as it moves into the cage 171

[0063] FIG. 4 and FIGS. 12A-12B illustrate an embodiment of a movable sealing element 468 (e.g., a poppet) and an OPR seal 442. These components are generally similar to the movable sealing element 168 and OPR seal 142 shown in FIGS. 1-3, with certain differences described below.

[0064] The movable sealing element 468 and OPR seal 442 may be incorporated into the overall valve assembly 130. For clarity and simplicity, certain details of the full assembly are omitted from FIG. 4. For example, the movable sealing element 468 may be connected to the armature 162 of the solenoid 160 and configured to move within and relative to the cage 171, in the same manner as the movable sealing element 168 depicted in FIGS. 1-3. The movable sealing element 468 includes a stem 402 extending downward and surrounded by a disk 448 oriented substantially perpendicular to the axis of the stem 402. One or more apertures 410 may be located between the stem 402 and the disk 448, allowing vapor to pass through — similar to the apertures 210 in the embodiment of FIGS. 1-3. The disk 448 may further include a first interface surface 446 near its distal edge, which is configured to contact an upper ridge of the outer seal 174 coupled to the lower end of the cage 171. When the disk 448 is pressed against the upper ridge of the outer seal 174, the vapor flow path between the cage 171 and the movable sealing element 468 is closed.

[0065] The stem 402 may be slidably received within a bore of the OPR seal 442, similar to how the stem 202 is received within the bore of OPR seal 142. The OPR seal 442 may have a smaller width than the opening at the bottom of the cage 171, creating a gap 480 between the OPR seal 442 and the cage 171 (including the outer seal 174). This allows the OPR seal 442 to pass through the opening and translate along the central axis into the cage 171.

[0066] The OPR seal 442 may generally have an inverted hat-like shape, with its wider end configured to interface with the movable sealing element 468 and receive the stem 402. The narrower end, opposite the wider end, may share the same geometry as the OPR seal 142 shown in FIGS. 1-2. The interior surface of the bore in the OPR seal 442 may be tapered to match thetaper of the stem 402. These taper geometries may be toleranced to improve alignment as the OPR seal 442 resets after movement and to compensate for fuel swell over the product's lifespan.

[0067] Additionally, as shown in the prior embodiment (e.g., FIG. 2), when the movable sealing element 468 and the OPR seal 442 are in the closed position (i.e., pressed against each other) a small gap remains between the distal end of the stem 402 and the corresponding interior surface of the OPR seal’s bore. This gap helps prevent mechanical interference across all operating conditions and manufacturing tolerances.

[0068] The OPR seal 442 may further include a spring-retaining feature 414, similar to springretaining feature 214, implemented as an annular groove around its outer surface to receive and retain the valve spring 150 (not shown in FIG. 4)

[0069] As shown in FIG. 4, the OPR seal 442 may be integrated with an inner seal component 443. The inner seal component 443 may be secured to the upper surface of the OPR seal 442, for example, through over-molding or by embedding a portion of the inner seal material into the body of the OPR seal 442 to ensure secure attachment. The inner seal component 443 may be composed of an elastomer or other elastic material, such as rubber, that is capable of deforming under pressure to facilitate sealing. The inner seal component, like the inner seal component 143 described earlier, may surround the central axis of the OPR seal 442 and sized to surround an the opening of the apertures 410 so that, when the movable sealing element 468 and the OPR seal 442 are pressed together, vapor passing through the apertures 410 would nevertheless be trapped by the seal created between the two pieces. When viewed from above, the inner seal component 143 may be substantially annular.

[0070] In certain embodiments, the inner seal component 443 may include a seal lip 450 that extends upward toward the disk 448. For example, the seal lip 450 may be angled, curved, or slanted upward and inward toward the axis of the OPR seal 442. In the cross section of the embodiment shown in FIG. 4, the seal lip 450 may resemble an arc that starts from the outer edge of the inner seal component 443 and curves upward toward the center. In 3D, the geometry of the seal lip 450 may resemble an annular wall that curves inwardly. This seal lip 450 may be geometrically designed to enable repeatable compression (flexing) and lift-off throughout the product’s lifespan, withstanding millions of operational cycles. Additionally, its geometry may be optimized to accommodate high flow rates while maintaining a low pressure drop.

[0071] As shown in FIG. 4, the seal lip 450 may be configured to interface with a second interface surface 444 located on the underside of the disk 448. The second interface surface 444 may be positioned closer to the axis of the movable sealing element 468 than the first interface surface 446 described above. It may also be located lower — closer to the distal end of the movable sealing element 468 — than the first interface surface 446. This second interface surface 444 is aligned with the opening at the bottom of the cage 171 to allow proper engagement with the OPR seal 442, and more specifically with the OPR seal’s inner seal component 443. In particular embodiments, the first interface surface 446 and the second interface surface 444 may be substantially flat.

[0072] During operation, the seal lip 450 may function similarly to a spring beam. For example, when pressed against the disk 448, the seal lip 450 may collapse to create a tight seal, while its resilient material allows it to flex and return to its original slanted shape once released. Specifically, when the disk 448 separates from the inner seal component 443 — either due to retraction of the armature 162 lifting the movable sealing element 468, or when tank pressure exceeds the biasing force of the valve spring 150 and pushes the OPR seal 442 downward — the angled or curved profile of the seal lip 450 may help redirect vapor flow away from the center axis toward the open passages (e.g., arrows 502 in FIG. 5) surrounding the OPR seal 442. This design facilitates smooth and rapid pressure release while improving fluid flow characteristics. Further details will be described below.

[0073] FIGS. 5, 7, and 8 illustrate the operational processes of the OPR and OVR functionalities of the valve assembly 130. In the embodiment shown, the movable sealing element 168 (as shown in FIGS. 1-3) is combined with the OPR seal 442 featuring the inner seal component 443 (as shown in FIG. 4). In this configuration, when the movable sealing element 168 and the OPR seal 442 are pressed together, the annular ridge 212 engages the inner seal component 443, sealing the flow path between them. While FIGS. 5-8 use this particular combination of components to illustrate the OPR and OVR operational processes, the concepts apply equally to other configurations, such as those shown in FIGS. 1-3 (movable sealing element 168 with OPR seal 142), FIG. 4 (movable sealing element 468 with OPR seal 442), and FIG. 9 (movable sealing element 968 with OPR seal 942).

[0074] FIG. 5 illustrates the mechanical OPR event. Referring back to FIG. 1 , which depicts the valve assembly 130 in its closed state, all flow paths between the inlet 133 and outlet 134 are sealed by respective sealing mechanisms. These include the seal between the outer seal 174 and the supporting structure 206, the seal between the outer seal 174 and the disk 148 of the movable sealing element 168, and the seal between the movable sealing element 168 and the OPR seal 142. In this closed state, the fuel tank forms a sealed environment isolated from the engine, allowing tank pressure to build up. For example, the tank pressure may lie within a predetermined range — above a first threshold but below a second threshold. The cage 171 is pressed downward by this tank pressure, with its bottom surface contacting the supporting structure 206 on the inner sidewall of the housing 132. As a result, the lower ridge of the outer seal 174 seals against the supporting structure 206, closing the flow path around the cage 171. Simultaneously, the movable sealing element 168 is pressed downward by the solenoid spring 164 and / or tank pressure. This causes the upper ridge of the outer seal 174 to seal against the disk 148 of the movable sealing element 168, closing the flow path between them. The OPR seal 142 is held upward by the valve spring 150 — with sufficient force to resist the downward tank pressure — so that the inner seal component 143 is pressed firmly against the disk 148, sealing the flow path between these components. Together, these seals ensure the valve assembly 130 is fully closed, preventing fluid flow through the valve.

[0075] Turning to FIG. 5, as the tank pressure increases beyond a higher threshold value (e.g., above the second threshold), it may overcome the upward biasing force of the valve spring 150, thereby pushing the OPR seal 442 (alternatively, OPR seal 142 or 942) downward. This downward movement opens vapor passages 502, allowing vapor to flow through the disk 148 (alternatively, disk 448 or 948) via apertures 210 (alternatively, apertures 410 or 910), through the gap between the disk and the inner seal component 443 (alternatively, inner seal component 143 or 943), and onward toward the outlet 134.

[0076] As previously discussed, the angled or slanted profile of the seal lip 450 helps direct vapor flow away from the center axis and toward the peripheral open passages 502 formed between the outer edges of the OPR seal 142, 442, 942 and the cage 171. In doing so, the seal lip 450 reduces the amount of vapor impinging directly on the OPR seal and instead channels more vapor efficiently through the designated flow paths. In particular embodiments where the disk includes a ridge 212 on its bottom surface, the ridge 212 may have a surface that is slanted downward andoutward toward the OPR seal 142, 442, 942. The slanted surface of the ridge 212 may work in tandem with the seal lip 450 to direct vapor to the open passage 502. This configuration promotes smoother fluid flow, more effective pressure relief, and reduced turbulence, thereby enhancing overall fluid dynamics. The OPR function serves as a mechanical safety backup to the active (solenoid-controlled) venting functions of the valve assembly 130. It ensures that excess fuel tank pressure is automatically relieved to prevent damage to the tank, seals, or connected components, and to comply with evaporative emissions standards and pressure safety requirements

[0077] FIG. 6 illustrates a configuration of the valve assembly 130 in the first open state of the two-stage opening process, initiated by energizing the solenoid 160. Upon activation, the solenoid 160 retracts the armature 162 upward, thereby lifting the movable sealing element 168, 468, 968 against the force of the solenoid spring 164. In the absence of both chamber pressure and the force of the solenoid spring 164, the valve spring 150 may decompress upward, allowing the OPR seal 142, 442, 942 to shift upward in unison with the movable sealing element 168, 468, 968. This coordinated movement maintains closure of the vapor passages 502. However, as the movable sealing element 168, 468, 968 is lifted, its disk 148, 448, 948 may disengage from the outer seal 174, thereby opening the passages 602 and permitting vapor flow therethrough. As shown, in this state, vapor may flow through the cage 171, through the disk 148, 448, 948 via the aperture 210, 410, 910, through the gap between the movable sealing element 168, 468, 968 and the OPR seal 142, 442, 942, and into the lower chamber and out to the outlet 134.

[0078] In the first open state, it is notable that the fuel tank pressure may be sufficiently high to press the cage 171 downward against the supporting structure on the bottom inner sidewall of the housing 132. This pressure maintains a sealed or closed condition between the cage 171 and the housing 132, enforced by the lower ridge of the outer seal 174. As a result, vapor flow is restricted to the relatively smaller passages 602 that are exposed during stage one. Consequently, the flow rate in this first open state is less than the full-flow capacity of the valve assembly 130. For this reason, the first open state may also be characterized as a low-flow, high-pressure condition.

[0079] FIGS. 7-8 illustrate a configuration of the valve assembly 130 in the second open state of the two-stage opening process. As pressure is gradually relieved during the first open state, the tank pressure may drop below a threshold level insufficient to counteract the upward biasing forceof the cage spring 172. When this occurs, the cage spring 172 extends, pushing the cage 171 upward and opening a large passage 802. Through this passage, vapor may flow from the inlet 133 and through the gap defined between the bottom of the cage 171 (as well as the outer seal 174) and the inner wall of the housing 132. This enables vapor to be released at the full capacity of the valve assembly 130. In this second open state, the passages 502 and 602 may remain closed or substantially closed due to the biasing effect of the valve spring 150, directing most — if not all — vapor flow through the large passage 802, thereby achieving a maximum release rate. Accordingly, this second open state may also be referred to as a high-flow, low-pressure condition.

[0080] FIG. 9 illustrates another embodiment of the movable sealing element 968 and OPR seal 942. Similar to the versions shown in previous figures, the movable sealing element 968 may be incorporated into the valve assembly 130 and interface with the cage 171 to provide the desired OVR and OPR functionalities. The sealing element 968 may include a stem that extends along its longitudinal axis and a disk 948 that surrounds the stem, oriented substantially perpendicular to it. One or more apertures 910 may be positioned between the stem and the outer portion of the disk 948, allowing vapor to pass through. The stem may be slidably inserted into a bore of the OPR seal 942. The OPR seal 942 may have a geometry similar to that of previously described seals (e.g., OPR seals 142, 442), but may differ in that it lacks an inner seal component for interfacing with the movable sealing element 968.

[0081] In contrast to the prior embodiments shown in FIGS. 1-8, the movable sealing element 968 — not the OPR seal — is integrated with an inner seal component 943. As illustrated, the inner seal component 943 may be coupled to the disk 948 of the movable sealing element 968, surrounding the aperture 910. When viewed from above or below, the inner seal component 943 may appear substantially annular, according to certain embodiments. The inner seal component 943 may be attached to the bottom surface of the disk 948, such as through an over-molding process. In some embodiments, a portion of the inner seal component 943 may be embedded within the disk 948 to enhance securement. The inner seal component 943 may be composed of an elastomer or another elastic material, such as rubber, that is deformable under pressure.

[0082] In certain embodiments, the inner seal component 943 may include a seal lip 902 that extends downward toward the OPR seal 942. This seal lip 902, which may be annular about the axis of the movable sealing element 968 and surround its apertures 910, may be angled, curved, orslanted downward and outward, away from the axis of the movable sealing element. This configuration allows the seal lip 902 to function similarly to a spring beam during operation. For instance, when pressed against the OPR seal 942, the seal lip 902 may flex upward to form a tight seal, then resiliently return to its original slanted geometry once the force is removed. Specifically, when the OPR seal 942 disengages from the inner seal component 943 — such as when the armature 162 retracts to lift the movable sealing element 168, or when tank pressure becomes high enough to overcome the valve spring 150 and depress the OPR seal 942 — the angled profile of the seal lip 902 may help direct vapor flowing through the aperture 910 outward from the axis of movable sealing element 168 toward the open passages between the seal lip 902 and the OPR seal 942 (e.g., similar to arrows 502 shown in FIG. 5). This flow-guiding geometry facilitates smoother pressure release and may enhance fluid dynamics within the valve assembly.

[0083] The inner seal component 943 may optionally include an interface surface 901 configured to interface with the upper ridge of the outer seal 174. This interface surface 901 may be positioned radially outward relative to the seal lip 902. Additionally, the interface surface 901 may be located higher in the longitudinal direction than the bottom tip of the seal lip 902. In particular embodiments, the interface surface 901 may be substantially flat. These geometries enable the interface surface 901 to interface with the upper ridge of the outer seal 174 while allowing the seal lip 902 to interface with the OPR seal 942.

[0084] Alternatively or additionally, to further improve fluid characteristics, the upper surface of the OPR seal 942 may be provided with one or more flow guides (not shown). For example, the flow guides may be configured similarly to the seal lip 450. E.g., the flow guides may extend upward towards the disk 148. The flow guides may be angled, curved, or slanted inward toward the axis of the movable sealing element so as to guide fluid flow away from the center and towards the open passages (e.g., the arrows 502 shown in FIG. 5). For example, the OPR seal 942 may be made of plastic, and the flow guides may also be made of plastic. For example, the flow guides may be integrally formed with the OPR seal 942 on its upper surface or otherwise attached or coupled to the OPR seal 942.

[0085] Alternatively or in addition, the valve spring 150 may be configured with a reduced spring rate to make it less rigid. This may be accomplished, for example, by decreasing the wire diameter of the spring. A lower spring rate can facilitate pressure release and improve vapor flowcharacteristics. To maintain structural stability and ensure proper support for the OPR seal, the coil count of the valve spring 150 may be increased accordingly.

[0086] FIG. 10 illustrates an example of the exterior of a 90-degree valve assembly 1030. While the functionality of the 90-degree valve assembly 1030 is the same as that of the 180-degree valve assembly 130 shown in FIGS. 1A-1B, the relative orientation of its inlet 1033 (for connection to the fuel tank) and its outlet 1034 (for connection to the recovery canister) is approximately perpendicular, forming a 90-degree angle.

[0087] FIG. 11 illustrates a cross-sectional view of the valve assembly 1030. As shown, aside from the perpendicular orientation of the inlet 1033 and outlet 1034, the internal structure of valve assembly 1030 is similar to that of previously described configurations and is capable of housing the same key components. In the illustrated example, the assembly incorporates the movable sealing element 468 and OPR seal 442, which are described in further detail in FIG. 4. However, other combinations may also be used, such as: movable sealing element 168 with OPR seal 142 (FIGS. 1-3); movable sealing element 168 with OPR seal 442 (FIGS. 5-8); or movable sealing element 968 with OPR seal 942 (FIG. 9).

[0088] Herein, “or” is inclusive and not exclusive, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A or B” means “A, B, or both,” unless expressly indicated otherwise or indicated otherwise by context. Moreover, “and” is both joint and several, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A and B” means “A and B, jointly or severally,” unless expressly indicated otherwise or indicated otherwise by context.

[0089] The scope of this disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments described or illustrated herein that a person having ordinary skill in the art would comprehend. The scope of this disclosure is not limited to the example embodiments described or illustrated herein. Moreover, although this disclosure describes and illustrates respective embodiments herein as including particular components, elements, feature, 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 a person having ordinary skill in the art would comprehend. Furthermore, reference in the appended claims to an apparatus orsystem or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative. Additionally, although this disclosure describes or illustrates particular embodiments as providing particular advantages, particular embodiments may provide none, some, or all of these advantages.

Claims

CLAIMSWhat is claimed is:

1. A valve assembly for a fuel tank, the valve assembly comprising: a valve housing having an inlet, an outlet, and a chamber between the inlet and outlet; a cage disposed within the chamber of the valve housing, the cage comprising an upper opening and a bottom opening opposite the upper opening; an outer seal coupled to the bottom opening of the cage; a movable sealing element that extends into the cage through the upper opening, the movable sealing element having an upper end and a lower end opposite to the upper end, the upper end of the movable sealing element being configured to be coupled to an actuator, and the lower end of the movable sealing element comprising a disk that is disposed within the cage and above the outer seal coupled to the bottom opening of the cage, the disk having one or more apertures for allowing vapor to pass through the disk; an over pressure release (OPR) seal disposed below the disk of the movable sealing element; and an inner seal component coupled to the OPR seal, the inner seal component comprising a seal lip; wherein the inner seal component is configured to seal a first vapor passage between the disk and the OPR seal when the disk and the OPR seal are pressed against each other, wherein the seal lip is configured to guide vapor flow toward the first vapor passage when the disk and the OPR seal are separated from each other to open the first vapor passage.

2. The valve assembly of Claim 1, wherein when the disk and the OPR seal are pressed against each other, the seal lip surrounds the one or more apertures of the disk.

3. The valve assembly of Claim 1, wherein the seal lip extends from a top surface of the OPR seal toward the disk.

4. The valve assembly of Claim 3, wherein the seal lip is curved upward toward the disk and inward toward an axis of the movable sealing element.

5. The valve assembly of Claim 1, wherein the disk comprises (i) a first interface surface configured to interface the outer seal and (ii) a second interface surface configured to interface the seal lip of the inner seal.

6. The valve assembly of Claim 5, wherein the second interface surface is substantially flat.

7. The valve assembly of Claim 5, wherein the second interface surface includes an annular ridge.

8. The valve assembly of Claim 7, wherein the annular ridge includes a surface that slants outward and downward toward the OPR seal.

9. The valve assembly of Claim 1, wherein the movable sealing element comprises a stem, and the OPR seal comprises a bore for receiving the stem.

10. The valve assembly of Claim 9, wherein the stem and the bore have tapered surfaces.

11. The valve assembly of Claim 9, wherein when the disk and the OPR seal are pressed against each other, a clearance gap exists between a distal end of the stem and an interior surface of the bore.

12. A valve assembly for a fuel tank, the valve assembly comprising: a valve housing having an inlet, an outlet, and a chamber between the inlet and outlet; a cage disposed within the chamber of the valve housing, the cage comprising an upper opening and a bottom opening opposite the upper opening; an outer seal coupled to the bottom opening of the cage; a movable sealing element that extends into the cage through the upper opening, the movable sealing element having an upper end and a lower end opposite to the upper end, the upper end of the movable sealing element being configured to be coupled to an actuator, and the lowerend of the movable sealing element comprising a disk that is disposed within the cage and above the outer seal coupled to the bottom opening of the cage, the disk having one or more apertures for allowing vapor to pass through the disk; an over pressure release (OPR) seal disposed below the disk of the movable sealing element; and an inner seal component coupled to the disk, the inner seal component comprising a seal lip; wherein the inner seal component is configured to seal a first vapor passage between the disk and the OPR seal when the disk and the OPR seal are pressed against each other, wherein the seal lip is configured to guide vapor flow toward the first vapor passage when the disk and the OPR seal are separated from each other to open the first vapor passage.

13. The valve assembly of Claim 12, wherein the seal lip surrounds the one or more apertures of the disk.

14. The valve assembly of Claim 12, wherein the seal lip extends from a bottom surface of the disk toward the OPR seal.

15. The valve assembly of Claim 14, wherein the seal lip is curved downward toward the OPR seal and outward.

16. The valve assembly of Claim 12, wherein the inner seal component further comprises an interface surface configured to interface with the outer seal.

17. The valve assembly of Claim 16, wherein the interface surface is substantially flat.

18. The valve assembly of Claim 12, wherein an upper surface of the OPR seal comprises one or more flow guides for guiding vapor flow.

19. The valve assembly of Claim 12, wherein the movable sealing element comprises a stem, and the OPR seal comprises a bore for receiving the stem.

20. The valve assembly of Claim 19, wherein the stem and the bore have tapered surfaces.

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