Combined refueling restrictor valve for hybrid vehicles

Abstract

This utility model relates to a combined fuel-limiting exhaust valve (CFLVV) for hybrid electric vehicles. It separates the gas valve (GVV) and fuel filler valve (FLVV) into a staggered, left-right arrangement. The valve body is injection molded in one piece, forming a high-position chamber, a low-position chamber, and a stepped seat between the two chambers, ensuring the GVV exhaust port is higher than the FLVV closing port. The flange and valve body are press-fitted, eliminating the need for an O-ring. The first float in the high-position chamber has a cup-shaped opening facing downwards, housing a first spring, a sealing plate at the top, a sealing head on the side, and a lateral through-hole serving as an exhaust channel. The second float in the low-position chamber also has a cup-shaped opening facing downwards, housing a second spring, with its lower end engaging with a sealing cone surface integrally formed at the bottom of the chamber to form a closing port. A 20-30cc reservoir is located above the FLVV for temporarily storing dynamically leaked fuel, which then flows back to the fuel tank through a return hole. This application features a compact structure, reliable sealing, and a large exhaust height, significantly reducing fuel tank space and increasing fuel filler capacity in hybrid vehicles.

Description

Technical Field

[0001] This utility model relates to the field of exhaust valves, specifically a combined refueling limit exhaust valve for hybrid vehicles. Background Technology

[0002] Currently, commercially available CLVVs generally adopt an "integrated" structure, which integrates all the valve cores, springs, floats, and other components of the GVV (Grade Vent Valve) and FLVV (Fill Limit Vent Valve) into the same housing. While this structure reduces the number of parts, shrinks the overall size, and lowers manufacturing costs, the shared housing between the GVV and FLVV forces compromises on their functional areas, resulting in a lower exhaust port height for the GVV.

[0003] With the increasing popularity of hybrid vehicles, the battery pack volume has increased significantly, and the fuel tank has been squeezed into a flat or irregular shape, further reducing the usable height.

[0004] To "fill up more fuel" in a "small fuel tank", the following must be met simultaneously: FLVV has a higher closing height, ensuring that the fuel level can rise closer to the top of the fuel tank before the refueling nozzle shuts off. The GVV has a higher exhaust height – a high fuel level in the tank provides sufficient exhaust capacity to prevent liquid fuel from entering the carbon canister when the fuel level is too high.

[0005] However, due to structural limitations, the exhaust port of the existing "integrated" CLVV can only be flush with the exhaust port of the FLVV at most, resulting in insufficient exhaust height. This means that the rated volume of the oil must be even lower to ensure that the GVV can maintain its exhaust function.

[0006] In summary, the shortcomings of the existing technology are summarized as follows: 1. Functional conflict: The GVV and FLVV share the same chamber, and the exhaust and refueling cut-off functions are mutually restrictive; 2. Limited height: The highest point of the GVV exhaust port can only be level with the FLVV exhaust port, and the space at the top of the fuel tank cannot be fully utilized; 3. Redundant sealing: O-ring secondary sealing is still required between the flange and the valve body, and the cost of parts and assembly cannot be further reduced; 4. Dynamic leakage risk: The one-piece structure lacks buffer volume, and liquid fuel can easily enter the venting line directly through the FLVV when the vehicle is bumpy. Utility Model Content

[0007] The present invention aims to overcome the defects of the prior art and provide a combined refueling limit exhaust valve for hybrid vehicles, thereby solving the above-mentioned technical problems.

[0008] To solve the above-mentioned technical problems, this utility model is implemented as follows: A combined refueling limiter exhaust valve for hybrid electric vehicles, comprising: a flange, a valve body, a GVV valve core assembly, an FLVV valve core assembly, and a reservoir; characterized in that: The GVV valve core assembly and the FLVV valve core assembly are arranged separately in the valve body and form a step difference along the vertical direction, so that the exhaust port of the GVV is higher than the closing port of the FLVV. The flange and valve body are directly sealed together by an interference fit, omitting the O-ring; The reservoir is located above the FLVV valve core assembly and is integrally formed with the valve body. It has a volume of 20–30 cc and is used to temporarily store dynamically leaking fuel.

[0009] The combined fuel-limiting exhaust valve for hybrid electric vehicles is characterized in that: the valve body is integrally formed with a stepped seat, which divides the valve body into a high-position chamber and a low-position chamber. The side wall of the high-position chamber is provided with a lateral through hole, the outlet of which is connected to the outside of the fuel tank or the charcoal canister, forming the exhaust channel of the GVV.

[0010] The combined refueling limit exhaust valve for hybrid electric vehicles is characterized in that: the GVV valve core assembly includes: The first float is slidably positioned in the high cavity; The first spring, located in the high-position cavity, has one end abutting the lower end of the first float and the other end abutting the upper surface of the stepped seat, and is used to lift the first float upward; A sealing head, fixed to the side of the first float, is used to open and close the lateral through hole; The top sealing plate is fixed to the upper end of the first float and is used to close the top opening of the high-position cavity when the float rises to the highest position.

[0011] The combined fuel-limiting exhaust valve for hybrid electric vehicles is characterized in that: the FLVV valve core assembly includes: The second float is slidably disposed in the lower cavity. The second float is cup-shaped with the opening facing downwards, and its interior forms an inner cavity. The third float is axially slidably stacked on top of the second float, and the two form a two-stage linkage float group. The third float has a small flow hole in the center, which is used to release pressure first when the pressure in the oil tank rises. A circular sealing plate is installed on the third float and moves synchronously with the third float to open and close the large hole at the top of the valve body; The second spring is built into the inner cavity of the second float, with its upper end abutting against the inner top wall of the second float and its lower end abutting against the bottom wall of the lower cavity; The bottom wall of the low-position cavity is provided with an integrally formed sealing cone surface, which cooperates with the sealing cone surface at the lower end of the second float to form a closing opening.

[0012] The combined refueling limit exhaust valve for hybrid electric vehicles is characterized in that: the top of the reservoir is provided with a return hole, and the bottom is connected to the lower chamber through a return oil channel, so that the temporarily stored fuel can flow back to the fuel tank.

[0013] The combined refueling limit exhaust valve for hybrid electric vehicles is characterized in that: the interference fit between the flange and the valve body is an interference press-fit structure, the length of the fitting section is 5–8 mm, the interference amount is 0.1–0.2 mm, forming a metal-plastic composite sealing interface.

[0014] The combined fuel-limiting exhaust valve for hybrid electric vehicles is characterized in that the vertical height difference between the exhaust port of the GVV and the closing port of the FLVV is 8–15 mm.

[0015] The combined refueling limit exhaust valve for hybrid electric vehicles is characterized in that it further includes a sealing ring and a sealing frame, the sealing frame is fixed to the lower end face of the third float, and the sealing ring is sandwiched between the sealing frame and the upper end face of the second float, for cutting off the communication between the flow passage orifice and the inner cavity when the valve re-seated in the third stage.

[0016] The beneficial effects of this utility model are as follows: As can be seen from the above technical solution, this application provides a combined refueling limited exhaust valve for hybrid electric vehicles. Without increasing the overall size, the GVV exhaust port is raised relative to the FLVV closing height, thereby fully releasing the space at the top of the fuel tank and increasing the effective volume. By replacing the O-ring with an interference fit between the flange and the valve body, the number of seals is reduced, costs are lowered, and reliability is improved. A 25cc reservoir is added above the FLVV to absorb dynamically leaked fuel and prevent liquid fuel from entering the carbon canister, thus meeting China VI and future stricter evaporative emission regulations.

[0017] First, the GVV exhaust port is raised 8–15 mm higher than the FLVV shut-off port, allowing the fuel level in the tank to rise safely to a higher position while maintaining unobstructed exhaust. This increases the effective fuel loading capacity within the same fuel tank volume, directly alleviating range anxiety caused by the battery encroaching on space in hybrid vehicles. At the same time, the exhaust passage is opened to the side and connected to the charcoal canister, which can maintain a stable air pressure balance during refueling and driving, avoiding "fuel choking" or charcoal canister liquid slugging failure.

[0018] Secondly, the longitudinal insertion depth of the flange and valve body interference fit is 3mm. The metal and plastic parts are assembled with interference fit using a 3mm long interference fit, eliminating the need for the traditional O-ring and its groove. This reduces a leakage path and saves an assembly process and parts cost, resulting in significant economic and reliability advantages in mass production. The interference fit of 0.1–0.2mm has been experimentally verified to maintain a seal under cycling conditions of -40℃ to 85℃, meeting the vehicle life requirements.

[0019] Third, the 20-30cc reservoir, integrally molded on top of the FLVV, can temporarily contain a small amount of fuel that has leaked through the sealing pair during vehicle shaking or rollover. It then quickly returns to the fuel tank after the vehicle's posture is restored via the top return hole and the bottom return channel, thereby reducing the amount of dynamic leakage by an order of magnitude. This ensures that there are no false alarms from the OBD system under China VI and future stricter evaporative emission limits, and extends the service life of the carbon canister.

[0020] Finally, the FLVV adopts a two-stage linkage structure of "third float stacked + circular sealing plate": the small hole depressurizes first, and the large hole closes later, so that the float assembly loses the sealing load in advance under the same back pressure in the tank, which significantly reduces the liquid level drop and internal pressure threshold required to reopen. Therefore, the float body can be made lighter and thinner, which not only improves the response speed to fuel sloshing and realizes "valve closes before fuel flows", but also reduces fatigue wear and noise caused by repeated impacts. Ultimately, the whole vehicle can still maintain precise shut-off under extreme conditions such as aggressive driving and refueling on slopes, avoiding premature shut-off or overflow when the fuel pump is full, and comprehensively improving the safety, comfort and durability of the hybrid vehicle fuel system. Attached Figure Description

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the structure of this application. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application. like Figure 1 As shown: A combined refueling limit exhaust valve for hybrid electric vehicles, comprising: flange 1, valve body 3, GVV valve core assembly, FLVV valve core assembly and reservoir 4; The GVV valve core assembly and the FLVV valve core assembly are arranged separately in the valve body 3, and a step difference is formed in the vertical direction, so that the exhaust port of GVV is higher than the closing port of FLVV. The flange 1 and valve body 3 are directly sealed together by an interference fit, omitting the O-ring; the interference fit between the flange 1 and valve body 3 is an interference press-fit structure with a fitting section length of 5–8 mm and an interference amount of 0.1–0.2 mm, forming a metal-plastic composite sealing interface.

[0023] The reservoir 4 is located above the FLVV valve core assembly and is integrally formed with the valve body 3. It has a volume of 20–30cc and is used to temporarily store dynamically leaked fuel. The top of the reservoir 4 is provided with a return hole, and the bottom is connected to the lower chamber through a return oil channel, so that the temporarily stored fuel can flow back to the fuel tank.

[0024] The valve body 3 is integrally formed with a stepped seat 33, which divides the valve body into a high-position chamber 31 and a low-position chamber 32. The side wall of the high-position chamber 31 is provided with a lateral through hole, and its outlet is connected to the outside of the oil tank or the charcoal canister to form the exhaust passage of the GVV.

[0025] The GVV valve core assembly includes: The first float 13 is slidably disposed in the high cavity 31; The first spring 14 is located in the high cavity 31, with one end abutting the lower end of the first float 13 and the other end abutting the upper surface of the stepped seat 33, and is used to lift the first float 13 upward. The sealing head 11 is fixed to the side of the first float and is used to open and close the lateral through hole; The top sealing plate 12 is fixed to the upper end of the first float 13 and is used to close the top opening of the high-position cavity 31 when the float rises to the highest position.

[0026] The vertical height difference between the exhaust port of the GVV and the closed port of the FLVV is 8–15 mm.

[0027] The FLVV valve core assembly includes: The second float 9 is slidably disposed in the low cavity 32. The second float 9 is cup-shaped with the opening facing downwards, and an inner cavity is formed inside it. The third float 5 is axially slidably stacked on top of the second float 9, and the two form a two-stage linkage float group. The third float 5 has a flow passage hole in the center, which is used to release pressure first when the pressure in the oil tank rises. The sealing ring 8 and the sealing frame 7 are fixed to the lower end face of the third float 5. The sealing ring 8 is sandwiched between the sealing frame 7 and the upper end face of the second float 9 to cut off the communication between the flow hole and the inner cavity when the float reseated in the third stage.

[0028] A circular sealing plate 6 is sandwiched between the second float 9 and the third float 5, and moves synchronously with the third float 5 to open and close the large hole at the upper end of the valve body 3. The second spring 10 is built into the inner cavity of the second float 9, with its upper end abutting against the inner top wall of the second float 9 and its lower end abutting against the bottom wall of the lower cavity 32. The bottom wall of the low cavity 32 is provided with an integrally formed sealing cone surface, which cooperates with the sealing cone surface at the lower end of the second float 9 to form a closing opening.

[0029] The dual-stage linkage float group is configured as follows: In the first stage, when the fuel level rises, the second float 9 first drives the third float 5 to rise synchronously until the circular sealing plate 6 contacts the large hole seat surface. At this time, the flow hole remains open to achieve small flow pressure relief. The second stage – as the liquid level continues to rise, the third float 5 slides further axially relative to the second float 9, causing the sealing ring 8 to press against the upper end face of the second float 9, closing the flow passage small hole, while the circular sealing plate 6 presses against the large hole, achieving complete closure of the large flow. During the liquid level drop, the third float 5 falls back first, the circular sealing plate 6 disengages from the large hole, and the flow passage small hole opens subsequently, thereby quickly balancing the pressure difference inside and outside the valve body 3, reducing the minimum internal pressure required for the float assembly to reopen as a whole, allowing the float assembly to use a lighter mass, thereby improving the FLVV closing sensitivity and cutting off fuel flow in advance.

[0030] By adopting the above technical solution, Resolving "functional conflicts" and "height limitations"—a modular staircase layout The GVV valve core and FLVV valve core were changed from "shared cavity" to "separate cavity": the two valve cores are vertically staggered to form a stepped drop.

[0031] The GVV exhaust port is thus raised higher than the closing height of the FLVV, allowing the fuel level to continue rising without prematurely submerging the GVV, thereby accommodating more fuel in the small fuel tank and directly increasing the effective volume.

[0032] Solving "Seal Redundancy" - Interference Fit of Flange and Valve Body Flange 1 and valve body 3 are fitted with an interference fit (H7 / p6), relying on the elastic deformation of metal and plastic to form a reliable seal, completely eliminating the traditional O-ring.

[0033] This reduces the number of parts, eliminates the time spent on O-ring groove machining and assembly, lowers the unit cost by about 8%, and eliminates the risk of leakage caused by O-ring aging.

[0034] Addressing the "Dynamic Leakage Risk" - 25cc Liquid Storage Box An integrally molded 25cc reservoir is added above the FLVV to form a buffer volume.

[0035] When the vehicle is bumped or the fuel nozzle is suddenly turned off, the fuel that splashes out instantly first enters the reservoir for temporary storage, and then flows back to the fuel tank by gravity, preventing liquid fuel from directly entering the vent pipe, significantly improving dynamic leakage indicators and meeting the China VI evaporative emission limits.

[0036] This invention raises the GVV exhaust port relative to the FLVV closing height without increasing the overall dimensions, thereby fully releasing the space at the top of the fuel tank and increasing the effective volume.

[0037] The above are merely embodiments provided in this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A combined fuel limiter exhaust valve for a hybrid electric vehicle, comprising: Flange (1), valve body (3), GVV valve core assembly, FLVV valve core assembly and liquid storage box (4); characterized in that: The GVV valve core assembly and the FLVV valve core assembly are arranged separately in the valve body (3) and form a step difference in the vertical direction, so that the exhaust port of GVV is higher than the closing port of FLVV. The flange (1) and the valve body (3) are directly sealed together by an interference fit, omitting the O-ring; The reservoir (4) is located above the FLVV valve core assembly and is integrally formed with the valve body (3). It has a volume of 20–30cc and is used to temporarily store dynamically leaked fuel.

2. The combined refueling limit exhaust valve for hybrid vehicles according to claim 1, characterized in that: The valve body (3) is integrally formed with a stepped seat (33), which divides the valve body into a high-position chamber (31) and a low-position chamber (32). The side wall of the high-position chamber (31) is provided with a lateral through hole, and its outlet is connected to the outside of the oil tank or the carbon canister to form the exhaust channel of the GVV.

3. The combined refueling limit exhaust valve for hybrid vehicles according to claim 2, characterized in that: The GVV valve core assembly includes: The first float (13) is slidably disposed in the high cavity (31). The first spring (14) is located in the high cavity (31), with one end abutting the lower end of the first float (13) and the other end abutting the upper surface of the step seat (33), and is used to lift the first float (13) upward. A sealing head (11) is fixed to the side of the first float and is used to open and close the lateral through hole; The top sealing plate (12) is fixed to the upper end of the first float (13) and is used to close the top opening of the high-position cavity (31) when the float rises to the highest position.

4. The combined refueling limit exhaust valve for hybrid vehicles according to claim 1, characterized in that: The FLVV valve core assembly includes: The second float (9) is slidably disposed in the lower cavity (32). The second float (9) is cup-shaped with the opening facing downwards, and an inner cavity is formed inside it. The third float (5) is axially slidably stacked on top of the second float (9), and the two form a two-stage linkage float group. The third float (5) has a flow passage hole in the center, which is used to release pressure first when the pressure in the oil tank rises. A circular sealing plate (6) is installed on the third float (5) and moves synchronously with the third float (5) to open and close the large hole at the top of the valve body (3); The second spring (10) is built into the inner cavity of the second float (9), with its upper end abutting against the inner top wall of the second float (9) and its lower end abutting against the bottom wall of the low cavity (32); The bottom wall of the low cavity (32) is provided with an integrally formed sealing cone surface, which cooperates with the sealing cone surface at the lower end of the second float (9) to form a closing port.

5. The combined refueling limit exhaust valve for hybrid vehicles according to claim 1, characterized in that: The top of the liquid storage box (4) is provided with a return hole, and the bottom is connected to the lower chamber through the return oil channel, so that the temporarily stored fuel can flow back to the fuel tank.

6. The combined refueling limit exhaust valve for hybrid vehicles according to claim 1, characterized in that: The flange (1) and the valve body (3) are press-fitted with an interference fit. The length of the fitting section is 5–8 mm and the interference amount is 0.1–0.2 mm, forming a metal-plastic composite sealing interface.

7. The combined refueling limit exhaust valve for hybrid vehicles according to claim 1, characterized in that: The vertical height difference between the exhaust port of the GVV and the closed port of the FLVV is 8–15 mm.

8. The combined refueling limit exhaust valve for hybrid vehicles according to claim 4, characterized in that: It also includes a sealing ring (8) and a sealing frame (7). The sealing frame (7) is fixed to the lower end face of the third float (5). The sealing ring (8) is sandwiched between the sealing frame (7) and the upper end face of the second float (9) to cut off the communication between the flow hole and the inner cavity when the float is reseated in the third stage.

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