Fuel level valve with separate float structure and method of operation

Abstract

A kind of fuel level valve of separate float structure and its working mode, including shell, float shell, float structure assembly, bottom cover, spring, O-ring;The float structure assembly includes lower float, first opening sealing pad, first buckle, second buckle, upper float, second opening sealing pad.In the process of refueling of hybrid electric vehicle, as the oil in tank rises, oil flows into shell, float structure assembly rises rapidly under the action of buoyancy, until first opening vent, second opening vent are in closed state, refueling is completed;Hybrid electric vehicle gradually reduces in the process of driving, lower float slowly falls due to gravity, first opening sealing pad and first opening vent gradually separate, realize first small flow automatic step-by-step pressure relief;When oil drops to a certain position, second opening sealing pad on upper float is separated from sealing state, so as to realize second large flow rapid pressure relief, so as to refuel tank again.

Description

Technical Field

[0001] The invention relates to the field of automobile fuel management systems, in particular to a fuel level valve with a separated float structure and a working method thereof. Background Art

[0002] The biggest difference between hybrid vehicles and traditional gasoline-powered vehicles, solely in terms of fuel usage, lies in their fuel tank systems. In traditional gasoline-powered vehicles, fuel vapors generated in the fuel tank are continuously released into the carbon canister. To meet the current China VI emissions regulations, the carbon canister must have sufficient capacity to absorb the vapors, resulting in a bulky structure and a high lifespan. When hybrid vehicles are powered by electricity, a fuel tank isolation valve prevents the release of fuel vapors into the carbon canister, achieving "zero" fuel vapor emissions and effectively reducing environmental pollution. However, during use, when fuel vapors cannot escape into the canister, the pressure within the tank continues to rise. This necessitates that the hybrid vehicle's fuel tank withstand pressures far greater than those of traditional fuel tanks. Furthermore, when the vehicle switches from electric power to gasoline-powered operation, the canister shutoff valve opens, rapidly venting the high-pressure fuel tank to the canister. This venting volume is significantly greater than in traditional gasoline-powered vehicles, requiring the various vent valves within the high-pressure tank to remain free of obstruction during this high-pressure, high-volume release. However, the limiting valve in a double-wall high-performance refueling limiting valve and its working method (patent number 202011490701X) currently used, such as Figure 11 As shown, the fuel tank comprises a housing 1, a float housing 2, a bottom cover 4, a spring 5, an O-ring 6, a float 7, and a sealing door 8. By designing two circular vent holes of different sizes, the primary and secondary pressure relief functions are realized according to the changes in the fuel in the fuel tank and the changes in the buoyancy and gravity of the float 7, thereby facilitating refueling. However, in actual use, during the primary pressure relief, due to the excessive pressure inside the fuel tank, the primary opening sealing plunger is difficult to fall off from the primary opening vent hole. As a result, when refueling the vehicle, it will take a long time to wait before refueling. In severe cases, it may even be difficult to refuel, affecting the normal use of the vehicle. Summary of the Invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a fuel level valve with a separate float structure and its working method, which solves the problems existing in the use of the fuel level valve of a hybrid vehicle.

[0004] Technical solution: The present invention provides a fuel level valve with a separate float structure and its working method, including a housing, a float housing, a float structure assembly, a bottom cover, a spring, and an O-ring. The float housing is arranged in the housing, the float structure assembly is arranged in the float housing, the bottom cover is arranged below the housing, the spring is arranged between the float structure assembly and the bottom cover, and the O-ring is arranged above the float housing; wherein, the float structure assembly includes a lower float, a first-level opening sealing gasket, a first clip, a second clip, an upper float, and a second-level opening sealing gasket. The first-level opening sealing gasket is connected to the upper end of the lower float and the lower end of the upper float by the first clip and the second clip, respectively, and the second-level opening sealing gasket is arranged at the upper end of the upper float. During the refueling process of the hybrid vehicle, as the oil in the fuel tank rises, the oil flows into the housing. After the oil enters, the float structure assembly rises rapidly under the action of buoyancy until the first-stage open vent and the second-stage open vent are in the closed state. At this time, refueling is completed. During the driving process of the hybrid vehicle, the oil in the fuel tank gradually decreases with use. At this time, the lower float slowly falls due to the influence of gravity. Since one end of the first-stage open seal is connected to the lower float by the first buckle and the other end is connected to the lower end of the upper float by the second buckle, that is, the first-stage open seal is rotated downward with the second buckle connection point as the axis under the force of the lower float, that is, the process of the first-stage open seal being released from the sealed state is carried out gradually, the exhaust volume of the oil vapor in the fuel tank gradually increases, and the high pressure in the fuel tank gradually decreases. When the oil drops to a certain position, the second-stage open seal on the upper float is released from the sealed state under the action of the lower float, thereby achieving a large flow of exhaust, so that the fuel tank can be refueled. The float structure is designed to consist of a separate lower float and upper float, which are connected by a first-stage opening seal, a first clip, and a second clip. This allows for automatic gradual pressure relief at a first-stage low flow rate and rapid pressure relief at a second-stage high flow rate during use, thereby resolving the problem of the original fuel level valve being unable to quickly relieve pressure under high pressure and improving the safety of the fuel tank and vehicle system.

[0005] Furthermore, the lower float is provided with a first-stage vent opening sealing base post, the end face of which is inclined; a first boss and a second boss are provided on the inclined face of the first-stage vent opening sealing base post; the lower float is also provided with a first fixing seat, located at the higher end of the inclined end face of the first-stage vent opening sealing base post; and a limiting groove is provided at the other end of the lower float, away from the first-stage vent opening sealing base post. During sealing, the first and second bosses reduce the contact surface between the first-stage vent opening sealing base post and the first-stage opening sealing gasket, thereby increasing the pressing force and improving the sealing performance. The first fixing seat is used to secure one end of the first-stage opening sealing gasket with a first clip; the limiting groove is used to install a spring. The inclined arrangement of the first-stage vent opening sealing base post, with the first fixing seat located at the higher end of the inclined end face of the first-stage vent opening sealing base post, quickly reduces the support area of ​​the first-stage vent opening sealing base post on the first-stage opening sealing gasket during first-stage pressure relief, thereby facilitating the smooth removal of the first-stage opening sealing gasket.

[0006] Furthermore, the first-stage opening sealing gasket is made of rubber and is integrally injection-molded. Its two ends are connected to the lower float and the upper float, respectively, via a first buckle and a second buckle. The first-stage opening sealing gasket is connected to the lower float and the upper float, respectively, via the first buckle and the second buckle. When the fuel tank is full, the first-stage opening sealing gasket abuts against the end of the first-stage opening vent sealing bottom column of the lower float and abuts against the first-stage opening vent sealing top column of the upper float, thereby sealing the first-stage opening vent of the upper float. As the oil in the fuel tank continues to decrease, as the lower float descends, the first-stage opening sealing gasket near the first fixed section is forced to rotate downward about the connection point between the second fixed section and the second buckle, gradually separating its upper portion from the end of the first-stage opening vent sealing bottom column of the upper float, thereby gradually opening the first-stage opening vent and automatically performing a first-stage low-flow pressure relief. When the first-stage opening sealing gasket rotates to a certain angle, the upper float connected to the second fixed section is forced to move downward, thereby performing a second-stage exhaust pressure relief. The first-stage opening seal is set in a Z shape. When the oil in the tank gradually decreases with use, the lower float will fall due to the influence of gravity. However, because the connection points at both ends of the first-stage opening seal connecting the upper and lower floats are not on the same vertical line with the center of gravity of the lower float, the first-stage opening seal will be moved by the lower float to the same vertical line, and will be out of the sealing state. The first-stage vent will be opened to achieve flow exhaust, and its operation is simple and convenient.

[0007] Furthermore, the upper float is provided with a first-stage opening vent sealing top post, the end face of which is inclined, and a first-stage opening vent is provided thereon, the first-stage opening vent being a waist-shaped hole. The upper float is also provided with a second fixing seat, located at the higher end of the inclined end face of the first-stage opening vent sealing top post. When the fuel tank is full of oil, the upper portion of the first-stage opening sealing gasket fits against the first-stage opening vent of the upper float, thereby providing a seal. The first-stage opening vent is a waist-shaped hole, so that when the first-stage opening vent is relieved, the first-stage opening sealing gasket gradually releases its seal against it. The end face of the first-stage opening vent sealing top post is arranged parallel to the end face of the first-stage opening vent sealing bottom post, thereby improving the seal fit.

[0008] Furthermore, a secondary opening seal installation groove is provided on the upper side wall of the upper float for installing the secondary opening seal. The secondary opening seal and the upper float are designed separately, which not only saves processing costs compared to the original rubber-coated structure, but also facilitates separate replacement, reducing parts loss costs.

[0009] Furthermore, the housing is provided with a first vent and a second vent, which are arranged relative to each other on the sidewalls of the housing. During refueling, as the liquid level gradually rises, upon reaching the first and second vents, the oil rapidly flows into the valve. After the oil enters, the float structure assembly rapidly rises under the action of buoyancy, and the first and second open vents are closed. Depending on the usage requirements of different fuel tanks, only the housing needs to be selected with the first and second vents at appropriate heights; the remaining parts do not need to be changed, making the system widely applicable.

[0010] Furthermore, the float housing is provided with a secondary open vent hole, which is a circular hole; a sealing ring mounting groove is also provided on the side wall of the end of the float housing; the float housing is also provided with a third vent and a fourth vent, which are relatively arranged on the side wall of the float housing; the float housing is also provided with a first oil inlet and a second oil inlet, which are relatively arranged at the bottom position of the side wall of the float housing. The second-level open vent is used for the discharge of large-flow oil vapor during the second-level pressure relief, and its size can be adjusted according to actual use requirements; the third vent and the fourth vent are used for exhausting oil vapor; the first oil inlet and the second oil inlet are arranged at the bottom position of the side wall of the float housing, so that even when the vehicle is running, even if the oil in the fuel tank enters between the housing and the float housing from the first air vent and the second oil inlet due to shaking, it will fall directly to the bottom of the valve due to gravity, and will not enter the third air vent or the fourth vent of the float housing with the oil vapor. At the same time, the oil enters the float housing through the first oil inlet and the second oil inlet, which will generate buoyancy on the float structure assembly, thereby blocking the first-level open vent and the second-level open vent, so that no oil will be discharged into the carbon canister by oil vapor.

[0011] Furthermore, a double-wall structure is formed between the outer shell and the float housing, and the outer shell and the upper end surface of the float housing are welded. The first and second vents on the outer shell are perpendicularly arranged through the center plane of the outer shell axis and the third and fourth vents on the float housing are perpendicularly arranged through the center plane of the float housing axis. This double-wall design ensures zero dynamic liquid leakage. Oil vapor is continuously generated in the fuel tank as the oil is used. It enters the valve through the first and second vents on the outer shell. When the pressure drops, it is discharged into the carbon canister through the third and fourth vents on the float housing through the first or second open vents. The first and second vents on the outer shell are perpendicularly arranged relative to the third and fourth vents on the float housing, maximizing the exhaust path for oil vapor. This also prevents oil leakage from accidents caused by bumps or even tipping of the vehicle.

[0012] Furthermore, a method for operating a fuel level valve with a separate float structure includes the following specific steps:

[0013] 1) When refueling, as the oil in the fuel tank continues to increase, the oil flows in through the first and second air vents on the housing, and enters the float housing through the first and second oil inlets of the float housing. The float structure assembly continues to rise under the buoyancy of the oil until the first and second open vents are closed by the first and second open sealing gaskets respectively. At this time, refueling is completed;

[0014] 2) During the driving process of a hybrid vehicle, the oil in its fuel tank gradually decreases with use, oil vapor is continuously generated, and the pressure in the fuel tank also increases;

[0015] 3) At this time, the lower float in the float structure assembly will slowly fall down under the action of gravity. Since one end of the first-stage opening sealing gasket is connected to the first fixing seat of the lower float through the first buckle, and the other end of the first-stage opening sealing gasket is connected to the second fixing seat of the upper float through the second buckle, that is, as the lower float falls, the first-stage opening sealing gasket is slowly flipped downward from a position close to the first buckle with the second buckle as the axis, and the contact area between the first-stage opening sealing gasket and the end surface of the first-stage opening vent sealing top column of the upper float becomes smaller and smaller, and the first-stage opening vent is gradually opened until the first-stage opening sealing gasket is completely separated from the end surface of the first-stage opening vent sealing top column. In this process, the oil vapor entering the valve through the first vent and the second vent on the outer shell is gradually discharged from the first-stage opening vent into the carbon canister along the third vent and the fourth vent on the float outer shell, and the discharge flow rate gradually increases, thereby realizing automatic and gradual pressure relief of a small first-stage flow rate.

[0016] 4) When the oil in the fuel tank drops to a certain height, the upper float falls together with the lower float. At this time, the secondary opening seal on the upper float falls off from the secondary opening vent of the float housing, that is, the sealing state is broken. At this time, a large flow of oil vapor is discharged from the secondary opening vent to the carbon canister, and the pressure in the fuel tank drops rapidly, achieving a secondary large flow pressure relief;

[0017] 5) At this point, the hybrid vehicle can be refueled again; and the cycle of steps 1) to 4) is repeated.

[0018] It can be seen from the above technical solution that the present invention has the following beneficial effects: 1) the float structure assembly is designed as a separate lower float and upper float, and the two are connected by a first-level opening sealing gasket, a first clip, and a second clip. Therefore, during the driving process of the hybrid vehicle, as the oil in the fuel tank is continuously used, the first-level small flow automatic gradual pressure relief and the second-level large flow rapid pressure relief can be achieved, thereby solving the problem that the original fuel level valve cannot quickly relieve pressure under high pressure; 2) the use of fuel level valves in different fuel tanks only requires replacing the outer shells with different vent heights to achieve different closing heights, which not only meets the diverse needs of customers, but also greatly saves the cost of designing other parts and molds, etc., and has wide applicability; 3) a double-wall structure is adopted, that is, a double shell of the outer shell and the float shell is set, so that under dynamic conditions, dynamic leakage of the liquid is zero, thereby improving the safety of the fuel tank and vehicle system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a cross-sectional view of the present invention;

[0020] Figure 2 It is a three-dimensional diagram of the lower float;

[0021] Figure 3 is a cross-sectional view of the lower float;

[0022] Figure 4 It is a three-dimensional diagram of the upper float;

[0023] Figure 5 This is a bottom view of the upper float;

[0024] Figure 6 is a three-dimensional diagram of the housing;

[0025] Figure 7 is a perspective view of the float housing;

[0026] Figure 8 A partial cross-sectional view of the present invention when the fuel tank is fully filled with fuel;

[0027] Figure 9 It is a partial cross-sectional view of the present invention in the first-level pressure relief state;

[0028] Figure 10 It is a partial cross-sectional view of the present invention in the secondary pressure relief state;

[0029] Figure 11 This is a cross-sectional view of the original product.

[0030] In the figure: housing 1, first air vent 11, second air vent 12, float housing 2, secondary open vent 21, sealing ring mounting groove 22, third air vent 23, fourth air vent 24, first oil inlet 25, second oil inlet 26, float structure assembly 3, lower float 31, primary open vent sealing bottom column 311, first boss 312, second boss 313, first fixing seat 314, limiting groove 315, primary open sealing gasket 32, first buckle 33, second buckle 34, upper float 35, primary open vent sealing top column 351, primary open vent 352, second fixing seat 353, secondary open sealing gasket mounting groove 354, secondary open sealing gasket 36, bottom cover 4, spring 5, O-ring 6, float 7, sealing door 8. DETAILED DESCRIPTION

[0031] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise explicitly specified.

[0034] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0035] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0036] Example 1

[0037] like Figure 1The figure shows a cross-sectional view of the present invention, which includes a housing 1, a float housing 2, a float structure assembly 3, a bottom cover 4, a spring 5, and an O-ring 6. The float housing 2 is disposed within the housing 1, the float structure assembly 3 is disposed within the float housing 2, the bottom cover 4 is disposed below the housing 1, the spring 5 is disposed between the float structure assembly 3 and the bottom cover 4, and the O-ring 6 is disposed above the float housing 2. The float structure assembly 3 includes a lower float 31, a primary opening seal 32, a first snap 33, a second snap 34, an upper float 35, and a secondary opening seal 36. The primary opening seal 32 is connected to the upper end of the lower float 31 and the lower end of the upper float 35 via the first snap 33 and the second snap 34, respectively. The secondary opening seal 36 is disposed at the upper end of the upper float 35.

[0038] like Figure 2 He Ru Figure 3 The figures show a stereoscopic view and a cross-sectional view of the lower float 31, respectively, on which a first-level open vent sealing bottom column 311 is provided, and the end face of the first-level open vent sealing bottom column 311 is inclined; a first boss 312 and a second boss 313 are provided on the inclined surface of the first-level open vent sealing bottom column 311; the lower float 31 is also provided with a first fixing seat 314, which is located at the higher end of the inclined end face of the first-level open vent sealing bottom column 311; a limiting groove 315 is provided at the other end of the lower float 31 away from the first-level open vent sealing bottom column 311.

[0039] The first-stage opening seal 32 is made of rubber and is integrally injection-molded. Its two ends are connected to the lower float and the upper float respectively via a first clip 33 and a second clip 34. The first-stage opening seal 32 selected in this embodiment is made of PA66, which has an operating temperature range of -40°C to 70°C.

[0040] like Figure 4 He Ru Figure 5 The figures show a cross-sectional view and a bottom view of the upper float 35, respectively, on which a first-level open vent sealing top column 351 is provided. The end face of the first-level open vent sealing top column 351 is inclined, and a first-level open vent 352 is provided on it. The first-level open vent 352 is a waist-shaped hole. The upper float 35 is also provided with a second fixing seat 353, which is located at the higher end of the inclined end face of the first-level open vent sealing top column 351.

[0041] A secondary opening sealing gasket installation groove 354 is provided on the upper side wall of the upper float 35 .

[0042] like Figure 6 The figure shows a three-dimensional view of the housing 1 , on which a first vent 11 and a second vent 12 are provided. The first vent 11 and the second vent 12 are arranged on the side wall of the housing 1 opposite to each other.

[0043] like Figure 7 The figure shows a three-dimensional view of the float housing 2, which is provided with a secondary open vent 21, which is a circular hole; a sealing ring mounting groove 22 is also provided on the side wall of the end of the float housing 2; the float housing 2 is also provided with a third vent 23 and a fourth vent 24, which are arranged oppositely on the side wall of the float housing 2; the float housing 2 is also provided with a first oil inlet 25 and a second oil inlet 26, which are arranged oppositely at the bottom position of the side wall of the float housing 2.

[0044] A double-wall structure is formed between the shell 1 and the float shell 2, and the shell 1 and the upper end surface of the float shell 2 are welded; the first air vent 11 and the second air vent 12 on the shell 1 pass through the center plane of the axis of the shell 1, and the third air vent 23 and the fourth air vent 24 on the float shell 2 pass through the center plane of the axis of the float shell 2 and are perpendicularly arranged.

[0045] like Figure 8 The figure shows a partial cross-sectional view of the present invention when the fuel tank is fully filled. At this time, the lower float 31 of the float structure assembly 3 moves upward under the action of buoyancy until the secondary opening seal 36 on the upper float 35 is in contact with the float housing 2. That is, the primary opening vent 352 and the secondary opening vent 21 are in a closed state, and no gas is discharged.

[0046] like Figure 9 The figure shows a partial cross-sectional view of the present invention in the first-stage pressure relief state. As the oil in the oil tank decreases with use, the lower float 31 will fall due to the influence of gravity. At this time, because the connection points of the first-stage opening sealing gasket 32 ​​connecting the lower float 31 and the upper float 35 are connected to the lower float 31 and the upper float 35 respectively through the first clip 33 and the second clip 34 are not on the same vertical line with the center of gravity of the lower float 31, the first-stage opening sealing gasket 32 ​​will be carried by the lower float to move toward the same vertical line, that is, the contact point between the first-stage opening sealing gasket 32 ​​and the end face of the first-stage opening vent sealing top column 351 of the upper float 35 begins to separate from the side close to the first clip 33, the first-stage opening vent 352 on the upper float 35 is gradually opened, and the oil vapor begins to be discharged from the first-stage opening vent 352, realizing the automatic and gradual pressure relief of the first-stage small flow until the first-stage opening vent 352 is fully opened.

[0047] like Figure 10The partial sectional view of the application in the secondary pressure relief state is shown. When the oil in the tank drops to a certain height, the upper float 35 falls under the gravity of the lower float 31 by the primary opening sealing pad 32, and the secondary opening sealing pad 36 on the upper float 35 is separated from the float shell 2. At this time, the secondary opening vent hole 21 is completely opened, and the primary opening vent hole 352 is recombined with the secondary opening sealing pad 36 as the upper float 35 falls. The oil vapor is discharged through the larger secondary opening vent hole 21, thereby realizing the secondary large flow pressure relief. After the large flow exhaust, the pressure balance of the fuel level valve is destroyed, and the original free state is restored to provide the refueling function again.

[0048] As shown in Figure 11 The sectional view of the original product is shown, including the shell 1, the float shell 2, the bottom cover 4, the spring 5, the O-ring 6, the float 7, and the sealing door 8.

[0049] The pressure drop performance test data of the original product and the application are shown in Table 1.

[0050]

[0051]

[0052] Table 1

[0053] From Table 1, the pressure drop performance of the original product is that when the valve body passes through 60L / min gas flow, the pressure is 0.2kPa; when the valve body passes through 70L / min gas flow, the pressure is 0.26kPa; when the valve body passes through 80L / min gas flow, the pressure is 0.33kPa; when the valve body passes through 90L / min gas flow, the pressure is 0.41kPa; and when the valve body passes through 100L / min gas flow, the pressure is 0.5kPa.

[0054] And the pressure drop performance of the application is that when the valve body passes through 60L / min gas flow, the pressure is 0.07kPa; when the valve body passes through 70L / min gas flow, the pressure is 0.09kPa; when the valve body passes through 80L / min gas flow, the pressure is 0.11kPa; when the valve body passes through 90L / min gas flow, the pressure is 0.13kPa; and when the valve body passes through 100L / min gas flow, the pressure is 0.15kPa.

[0055] In summary, the pressure drop of the application is much lower than that of the original product, thereby ensuring smoother refueling and exhaust of the vehicle tank, wider application, and being applicable to ordinary fuel vehicles and high-pressure hybrid vehicles.

[0056] Table 2 shows the static and dynamic performance test data for the existing product and the present invention under valve re-opening conditions. Static re-opening refers to the situation where, during steady driving, as the fuel tank liquid level drops, the valve core (the float structure assembly 3 of the present invention) must drop accordingly to open the valve. If it fails to open, the pressure in the high-pressure tank cannot be released, and the initial tank pressure cannot be restored, making subsequent refueling impossible. Dynamic re-opening refers to the situation where, during bumps, sudden acceleration, sudden braking, or violent shaking of the vehicle, the fuel in the tank sloshes, causing the valve core (the float structure assembly 3 of the present invention) to float up, and then must be able to drop again to open the valve body.

[0057]

[0058]

[0059]

[0060] Table 2

[0061] As can be seen from Table 2, the static and dynamic reopening performance of the original product cannot return to the initial state when the product is rotated, the valve body cannot open automatically, and the gas flow rate is 0L / min. The static opening performance of the present invention can automatically open the valve body when the product is rotated back to the initial state, and the gas flow rate can reach 64.1L / min; the dynamic reopening performance of the present invention can automatically open the valve body when the product is rotated back to an angle of 36 degrees, and the gas flow rate can reach 30.3L / min. The valve reopening performance of the present invention is far superior to the original product. Therefore, the present invention can meet the use of hybrid vehicles represented by high-pressure fuel tanks under extreme working conditions (such as mountain off-road), and its scope of application is wider.

[0062] Table 3 shows the blocked airflow test data of the original product and the present invention.

[0063] Gas flow Is the valve blocked? The present invention 307L / min Valve blockage Original product 212L / min Valve blockage

[0064] Table 3

[0065] As shown in Table 3, the original product's valve becomes clogged when a gas flow rate greater than 212 L / min passes through the valve body; however, the valve of the present invention only becomes clogged when a gas flow rate greater than 307 L / min passes through the valve body. The present invention's performance in the clogged airflow test is far superior to the original product.

[0066] Table 4 shows the pressure relief time test data of the original product and the present invention.

[0067] The internal pressure of the fuel tank is released from 30kPa to 2kPa, the time for the pressure to be released (s) The present invention 11 Original product 20

[0068] Table 4

[0069] As shown in Table 4, the existing product takes approximately 20 seconds to release the internal pressure of the fuel tank from 30kPa to 2kPa, while the present invention takes approximately 11 seconds to release the internal pressure from 30kPa to 2kPa. This superior release time compared to the existing product can reduce refueling wait times for end-users of hybrid vehicles with high-pressure fuel tanks, improving the customer experience.

[0070] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A fuel level valve with a separate float structure, characterized by: The float structure assembly comprises a housing (1), a float housing (2), a float structure assembly (3), a bottom cover (4), a spring (5), and an O-ring (6), wherein the float housing (2) is arranged in the housing (1), the float structure assembly (3) is arranged in the float housing (2), the bottom cover (4) is arranged below the housing (1), the spring (5) is arranged between the float structure assembly (3) and the bottom cover (4), and the O-ring (6) is arranged above the float housing (2); wherein the float structure assembly (3) comprises a lower float (31), a first-stage opening sealing gasket (32), a first buckle (33), a second buckle (34), an upper float (35), and a second-stage opening sealing gasket (36), and the first-stage opening sealing gasket (32) is connected at both ends to the lower float and the upper float via the first buckle (33), the second buckle (34), respectively; The secondary opening sealing gasket (36) is arranged on the upper end of the upper float (35); The housing (1) is provided with a first vent (11); The first-stage opening sealing gasket (32) is connected to the upper end of the lower float (31) and the lower end of the upper float (35) through a first buckle (33) and a second buckle (34), respectively; The upper float (35) is provided with a first-stage opening vent hole (352); The float housing (2) is provided with a secondary opening vent hole (21), a third vent hole (23), and a first oil inlet (25), wherein the first oil inlet (25) is arranged at the bottom of the side wall of the float housing (2); During refueling, as the oil in the fuel tank continues to increase, the oil flows in through the first vent (11) on the housing (1) and enters the float housing (2) through the first oil inlet (25) of the float housing (2). The float structure assembly (3) continues to rise under the buoyancy of the oil until the first-stage opening vent (352) and the second-stage opening vent (21) are in a closed state under the action of the first-stage opening sealing gasket (32) and the second-stage opening sealing gasket (36), respectively. At this time, refueling is completed; The oil in the oil tank gradually decreases with use. At this time, the lower float (31) in the float structure assembly (3) will slowly fall under the action of gravity. Since one end of the first-stage opening seal (32) is connected to the lower float (31), and the other end of the first-stage opening seal (32) is connected to the upper float (35), that is, at this time, as the lower float (31) falls, the first-stage opening vent (352) is gradually opened until the first-stage opening seal (32) is completely separated from the end face of the first-stage opening vent sealing top column (351). In this process, the oil vapor that enters the valve through the first vent (11) and the second vent (12) on the shell (1) is gradually discharged from the first-stage opening vent (352) to the carbon canister along the third vent (23) on the float shell (2). The discharge flow rate gradually increases, realizing the automatic and gradual pressure relief of the first-stage small flow rate. When the oil in the oil tank drops to a certain height, the upper float (35) falls together with the lower float (31). At this time, the secondary opening seal (36) on the upper float (35) falls off from the secondary opening vent (21) of the float housing (2), and the pressure in the oil tank drops rapidly, achieving secondary large flow pressure relief.

2. The fuel level valve with a separate float structure according to claim 1, characterized in that: The lower float (31) is provided with a first-stage open vent hole sealing bottom column (311), and the end surface of the first-stage open vent hole sealing bottom column (311) is inclined; a first boss (312) and a second boss (313) are provided on the inclined surface of the first-stage open vent hole sealing bottom column (311); the lower float (31) is also provided with a first fixing seat (314), which is located at the higher end of the inclined end surface of the first-stage open vent hole sealing bottom column (311); and a limiting groove (315) is provided at the other end of the lower float (311) away from the first-stage open vent hole sealing bottom column (311).

3. The fuel level valve with a separate float structure according to claim 1, characterized in that: The first-level opening sealing gasket (32) is made of rubber and is integrally injection-molded.

4. The fuel level valve with a separate float structure according to claim 2, characterized in that: The upper float (35) is provided with a first-level opening vent hole sealing top column (351), the end surface of the first-level opening vent hole sealing top column (351) is inclined, and a first-level opening vent hole (352) is provided thereon, and the first-level opening vent hole (352) is a waist-shaped hole. The upper float (35) is also provided with a second fixing seat (353), which is located at the higher end of the inclined end surface of the first-level opening vent hole sealing top column (351).

5. The fuel level valve with a separate float structure according to claim 4, characterized in that: A secondary opening sealing gasket installation groove (354) is provided on the upper end side wall of the upper float (35).

6. The fuel level valve with a separate float structure according to claim 1, characterized in that: The housing (1) also has a second vent (12), and the first vent (11) and the second vent (12) are arranged relatively on the side wall of the housing (1).

7. The fuel level valve with a separate float structure according to claim 6, characterized in that: The secondary opening vent hole (21) is a circular hole; a sealing ring mounting groove (22) is further provided on the side wall of the end of the float housing (2); a fourth vent hole (24) is further provided on the float housing (2); the third vent hole (23) and the fourth vent hole (24) are relatively arranged on the side wall of the float housing (2); a second oil inlet (26) is further provided on the float housing (2); the first oil inlet (25) and the second oil inlet (26) are relatively arranged at the bottom position of the side wall of the float housing (2).

8. The fuel level valve with a separate float structure according to claim 7, characterized in that: A double-wall structure is formed between the shell (1) and the float shell (2), and the shell (1) and the upper end surface of the float shell (2) are welded; the first vent (11) and the second vent (12) on the shell (1) pass through the center plane of the axis of the shell (1), and the third vent (23) and the fourth vent (24) on the float shell (2) pass through the center plane of the axis of the float shell (2) and are vertically arranged.

9. An operating method of a fuel level valve with a separate float structure as claimed in claim 4, characterized in that: The specific steps are as follows: 1) When refueling, as the oil in the fuel tank continues to increase, the oil flows in through the first vent (11) and the second vent (12) on the housing (1), and enters the float housing (2) through the first oil inlet (25) and the second oil inlet (26) of the float housing (2). The float structure assembly (3) continues to rise under the buoyancy of the oil until the first-stage opening vent (352) and the second-stage opening vent (21) are in a closed state under the action of the first-stage opening sealing gasket (32) and the second-stage opening sealing gasket (36), respectively. At this time, refueling is completed; 2) During the driving process of a hybrid vehicle, the oil in its fuel tank gradually decreases with use, oil vapor is continuously generated, and the pressure in the fuel tank also increases; 3) At this time, the lower float (31) in the float structure assembly (3) will slowly fall under the action of gravity. Since one end of the first-stage opening seal (32) is connected to the first fixing seat (314) of the lower float (31) through the first buckle (33), the other end of the first-stage opening seal (32) is connected to the second fixing seat (353) of the upper float (35) through the second buckle (34), that is, as the lower float (31) falls, the first-stage opening seal (32) is slowly turned downward from the position close to the first buckle with the second buckle as the axis, and the first-stage opening ventilation of the upper float (35) is connected. The contact surface of the end face of the hole sealing top column (351) is also getting smaller and smaller, and the first-stage opening vent hole (352) is gradually opened until the first-stage opening sealing gasket (32) is completely separated from the end face of the first-stage opening vent hole sealing top column (351). During this process, the oil vapor entering the valve through the first vent port (11) and the second vent port (12) on the housing (1) is gradually discharged from the first-stage opening vent hole (352) into the carbon canister along the third vent port (23) and the fourth vent port (24) on the float housing (2). The discharge flow rate is gradually increased, thereby realizing the automatic and gradual pressure relief of the first-stage small flow rate. 4) When the oil in the oil tank drops to a certain height, the upper float (35) falls down together with the lower float (31). At this time, the secondary opening seal (36) on the upper float (35) falls off from the secondary opening vent (21) of the float housing (2), that is, the sealing state is broken. At this time, a large flow of oil vapor is discharged from the secondary opening vent (21) to the carbon canister, and the pressure in the oil tank drops rapidly, thus achieving a secondary large flow pressure relief. 5) At this point, the hybrid vehicle can be refueled again; and the operations 1) to 4) are repeated.

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