Fuel level valve

Abstract

This utility model relates to the field of fuel tank valve body manufacturing technology, and discloses a fuel level valve, comprising: a valve body having a cavity inside, an external flow inlet and an external flow outlet on the valve body, the external flow inlet being located at the top side of the cavity, and the external flow outlet communicating with the top of the cavity; an inner cylinder disposed within the cavity, the inner cylinder having a valve chamber, an internal flow inlet on the side wall of the inner cylinder, and a first vent at the upper end of the side wall of the inner cylinder; a leakage fine hole at the bottom of the valve chamber; a float slidably disposed within the valve chamber, the upper end of the float having a sealing plug corresponding to the external flow outlet; and an opening at the upper end of the inner cylinder, with a vent gap between the upper end of the inner cylinder and the top of the cavity. This effectively increases venting efficiency and avoids obstructed venting.

Description

Technical Field

[0001] This utility model relates to the field of fuel tank valve body manufacturing technology, specifically to a fuel level valve. Background Technology

[0002] The fuel level valve (also known as an anti-overfill valve or fuel limit valve) is an important safety device in automotive fuel systems, typically installed inside the fuel tank of passenger vehicles. Its main function is to monitor the fuel level in the tank in real time during refueling. When the tank is nearly full, it automatically triggers the fuel nozzle to shut off, preventing fuel from overflowing and thus avoiding waste and environmental pollution, while also ensuring refueling safety. Furthermore, this valve effectively prevents fuel from escaping through the vent during vehicle operation, while also ensuring pressure balance inside and outside the fuel tank.

[0003] The exhaust performance of the valve chamber is an important technical indicator of fuel level valves, and improving this indicator is also the direction of its iterative development. According to the inventors' analysis, in existing technologies, such as the fuel level valve with a separate float structure disclosed in Chinese invention patent application CN114771239A, the exhaust port of the valve chamber is mostly located at the top of the valve chamber, but the top sidewall of the valve chamber is closed. This causes the sidewall of the valve chamber closest to the exhaust port to act as a flow obstruction, hindering the smoothness of exhaust. Utility Model Content

[0004] To overcome the shortcomings of the prior art, this utility model provides a fuel level valve that can effectively increase exhaust efficiency and avoid poor exhaust flow.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution: A fuel level valve, comprising: The valve body has a cavity inside, and an external flow inlet and an external flow outlet are provided on the valve body. The external flow inlet is located at the top of the side of the cavity, and the external flow outlet is connected to the top of the cavity. The inner cylinder is located within the cavity, and a valve chamber is provided inside the inner cylinder. An inner flow channel inlet is provided on the side wall of the inner cylinder, and a first vent is provided at the upper end of the side wall of the inner cylinder. A leakage hole is provided at the bottom of the valve chamber. The float is slidably disposed in the valve cavity, and the upper end of the float is provided with a sealing plug corresponding to the air outlet passage; The upper end of the inner cylinder is open, and there is a ventilation gap between the upper end of the inner cylinder and the top of the cavity.

[0006] Furthermore, in one fuel level valve of this application, a flange is provided at the top of the cavity. The flange is located between the vent gap and the inlet of the outer flow channel, and is used to isolate the inlet of the outer flow channel and the vent gap in the radial direction. As a preferred embodiment of this application, by providing the flange, it is possible to effectively prevent the fuel from sloshing in the fuel tank and directly overflowing from the inlet of the outer flow channel to the outlet flow channel after entering the outer flow channel.

[0007] Furthermore, in one fuel level valve of this application, the first exhaust port is circumferentially offset from the inlet of the outer flow channel. As a preferred embodiment of this application, because the first exhaust port is circumferentially offset from the inlet of the outer flow channel, it can prevent fuel from directly entering the outlet flow channel from the first exhaust port.

[0008] Furthermore, in this application, a fuel level valve includes a valve body comprising an outer cylinder with a bottom opening, a cavity located inside the outer cylinder, an outer flow channel inlet disposed on the outer cylinder, a bottom cover connected to the open end of the outer cylinder, and an inner cylinder integrally disposed on the bottom cover. The bottom cover is used to limit the bottom range of the cavity and the valve chamber.

[0009] Furthermore, in a fuel level valve of this application, the valve body also includes a connecting plate and a connector integrally formed with the outer cylinder. The connecting plate and the connector are disposed above the outer cylinder. The connecting plate is used to connect to the fuel tank, and the outlet flow channel is disposed within the connector. As a preferred embodiment of this application, the integral arrangement of the connecting plate and the outer cylinder reduces the longitudinal space for sealing connection compared to the traditional separate arrangement. This maximizes the height of the outlet flow channel inlet while maintaining a consistent inlet size.

[0010] Furthermore, in one fuel level valve of this application, a second vent is provided on the inner cylinder sidewall, and the second vent is disposed opposite to the inlet of the outer flow channel. As a preferred embodiment of this application, the second vent is used to balance the air pressure inside and outside the valve cavity.

[0011] Furthermore, in one fuel level valve of this application, the number of second vents opposite each external flow channel inlet is at least two. As a preferred embodiment of this application, the area of ​​the second vents can be dispersed, reducing the risk of leakage.

[0012] Furthermore, in one fuel level valve of this application, the second exhaust port extends obliquely on the inner cylinder sidewall, such that the outer end of the second exhaust port is higher than the inner end. As a preferred embodiment of this application, the obliquely arranged second exhaust port forms a certain degree of longitudinal air guide channel, which can improve the efficiency of balancing the air pressure in the valve chamber during the upward movement of the float, while preventing fuel from overflowing directly from the second exhaust port into the outlet air passage due to fuel sloshing during refueling.

[0013] Furthermore, in one of the fuel level valves of this application, the size of the vent gap is between 0.3 mm and 1 mm.

[0014] Furthermore, in one fuel level valve of this application, the inlet of the inner flow channel is located at the bottom of the inner cylinder side wall.

[0015] As can be seen from the above technical solution, this utility model has the following beneficial effects: This invention provides a fuel level valve, installed inside the fuel tank. Its working principle is as follows: During refueling, the fuel level rises. When the level exceeds the inlet of the outer flow channel, fuel enters the container from the outer flow channel inlet and then enters the valve chamber from the inner flow channel inlet, causing the float to rise and move upwards until it blocks the opening of the outlet flow channel near the container, thus cutting off the outlet flow. Upon further refueling, the gas pressure inside the fuel tank rises sharply, triggering the refueling nozzle to shut off. During refueling, the gas in the fuel tank mainly enters the valve chamber through the first vent and is discharged. After the fuel level in the tank drops, the fuel in the valve chamber is discharged through the leakage hole, and the float descends with the liquid level, opening the outlet flow channel, allowing the fuel tank to release pressure through the outlet flow channel. When the car shakes (such as driving on a bumpy road), the fuel in the tank shakes, and the fuel entering the valve chamber causes the float to rise and block the outlet flow channel, thus preventing fuel from overflowing. The ventilation gap forms an exhaust channel surrounding the outlet air passage opening. Because the ventilation gap is located at the top of the inner cylinder and is closest to the outlet air passage, it can effectively increase exhaust efficiency and avoid poor exhaust. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a fuel level valve according to an embodiment of this application; Figure 2 This is a cross-sectional view of the inlet position of the external flow channel of a fuel level valve in an embodiment of this application; Figure 3 for Figure 2 A magnified view of a portion of area A in the center circle; Figure 4 This is a cross-sectional view of the inlet position of the internal flow channel of a fuel level valve in an embodiment of this application; Figure 5 This is a schematic diagram of the integrated inner cylinder and bottom cover in an embodiment of this application.

[0017] In the diagram: 1-valve housing; 11-outer flow channel inlet; 12-outlet flow channel; 13-flange; 14-outer cylinder; 15-connecting plate; 16-connector; 2-inner cylinder; 20-inner flow channel inlet; 21-first exhaust port; 22-second exhaust port; 23-ventilation gap; 3-float; 31-sealing plug; 4-bottom cover; 41-leakage orifice; 5-spring. Detailed Implementation Example

[0018] Combination Figures 1 to 4 A fuel level valve, as shown, includes: The valve housing 1 has a cavity inside. The valve housing 1 has an external flow inlet 11 and an external flow outlet 12. The external flow inlet 11 is located at the top of the side of the cavity, and the external flow outlet 12 is connected to the top of the cavity. The inner cylinder 2 is located inside the cavity. The inner cylinder 2 has a valve chamber. The inner cylinder 2 has an inner flow channel inlet 20 on its side wall. Specifically, the inner flow channel inlet 20 is located at the bottom of the side wall of the inner cylinder 2. The upper end of the side wall of the inner cylinder 2 has a first exhaust port 21. The valve chamber is provided with a small leakage hole 41 at the bottom; The float 3 is slidably disposed in the valve cavity, and the upper end of the float 3 is provided with a sealing plug 31 corresponding to the air outlet passage 12; The inner cylinder 2 has an opening at its upper end, and a ventilation gap 23 is provided between the upper end of the inner cylinder 2 and the top of the cavity. Specifically, the size of the ventilation gap 23 is between 0.3 mm and 1 mm. Preferably, the size of the ventilation gap 23 is 0.6 mm.

[0019] Based on the above structure, a fuel level valve is installed inside the fuel tank. Its principle is as follows: During refueling, the fuel level in the tank rises. When the level exceeds the outer inlet 11, fuel enters the container from the outer inlet 11 and then enters the valve chamber from the inner inlet 20, causing the float 3 to rise and move upwards until it blocks the opening of the outlet passage 12 near the cavity, thus cutting off the outlet passage 12. Upon further refueling, the gas pressure inside the tank rises sharply, triggering the refueling nozzle to shut off. During refueling, the gas in the tank mainly enters the valve chamber through the first exhaust port 21 and is discharged. After the fuel level in the tank drops, the fuel in the valve chamber is discharged through the leakage hole 41. The float 3 descends with the fuel level, allowing the outlet passage 12 to open, and the fuel tank can release pressure through the outlet passage 12. When the car shakes (such as when driving on a bumpy road), the fuel in the tank will slosh around. The fuel entering the valve chamber will cause the float 3 to rise and block the air outlet passage 12, thus preventing fuel from overflowing from the air outlet passage 12. The vent gap 23 forms an exhaust passage surrounding the opening of the air outlet passage 12. Because the vent gap 23 is located at the top of the inner cylinder 2 and is closest to the opening of the air outlet passage 12, it can effectively increase exhaust efficiency and avoid poor exhaust.

[0020] The specific structure of the float 3 in this embodiment can be referenced from the float assembly with a two-stage opening function disclosed in Chinese invention patent application CN114771239A. A spring 5 is attached to the bottom of the float 3, and the spring 5 is used to offset part of the resistance acting on the float 3 to rise, thereby improving the float 3's buoyancy sensitivity. It should be noted that the opening sizes of the outer flow channel inlet 11 and the inner flow channel inlet 20 are much larger than the leakage orifice 41, so that during the refueling process, the oil mainly enters the valve chamber through the outer flow channel inlet 11 and the inner flow channel inlet 20. Specifically, the diameter of the leakage orifice 41 ranges from 0.8mm to 0.12mm, preferably 1.05mm.

[0021] In this embodiment, a flange 13 is provided at the top of the cavity. The flange 13 is located between the venting gap 23 and the external flow channel inlet 11. The flange 13 is used to isolate the external flow channel inlet 11 and the venting gap 23 in the radial direction. By setting the flange 13, it is possible to effectively prevent the oil from entering the external flow channel inlet 11 and overflowing directly from the external flow channel inlet 11 to the outlet flow channel 12 when the oil in the tank is sloshing.

[0022] In this embodiment, the first exhaust port 21 is circumferentially offset from the outer flow channel inlet 11. Because the first exhaust port 21 is circumferentially offset from the outer flow channel inlet 11, it can prevent oil from directly entering the outlet flow channel 12 from the first exhaust port 21.

[0023] In this embodiment, the valve housing 1 includes an outer cylinder 14 with a bottom opening, a cavity located inside the outer cylinder 14, an outer flow channel inlet 11 disposed on the outer cylinder 14, a bottom cover 4 snapped onto the open end of the outer cylinder 14, and an inner cylinder 2 integrally disposed on the bottom cover 4. The bottom cover 4 is used to limit the bottom range of the cavity and the valve chamber.

[0024] In this embodiment, the valve housing 1 also includes a connecting plate 15 and a connector 16 integral with the outer cylinder 14. The connecting plate 15 and the connector 16 are disposed above the outer cylinder 14. The connecting plate 15 is used to connect to the oil tank, and the air outlet passage 12 is disposed in the connector 16.

[0025] By integrating the connecting plate 15 and the outer cylinder 14, compared to the traditional separate design, the longitudinal space for sealing connection is reduced. This allows for maximizing the height of the outer flow channel inlet 11 while maintaining a consistent opening size. Specifically, the first exhaust port 21 is U-shaped.

[0026] Combination Figure 2 and Figure 5 As shown, in this embodiment, a second exhaust port 22 is provided on the side wall of the inner cylinder 2, and the second exhaust port 22 is arranged opposite to the inlet 11 of the outer flow channel. The second exhaust port 22 is used to balance the air pressure inside and outside the valve cavity.

[0027] In this embodiment, the number of second vents 22 opposite to each external flow channel inlet 11 is at least two. This disperses the area of ​​the second vents 22, reducing the risk of leakage. In this embodiment, the number of second vents 22 opposite to each external flow channel inlet 11 is three, and the diameter of each second vent 22 is 3 mm.

[0028] In this embodiment, the second exhaust port 22 extends obliquely on the side wall of the inner cylinder 2, such that the outer end of the second exhaust port 22 is higher than the inner end. The obliquely arranged second exhaust port 22 forms a certain degree of longitudinal air guiding channel, which can improve the efficiency of balancing the air pressure in the valve chamber during the upward movement of the float 3, and at the same time prevent oil from overflowing directly from the second exhaust port 22 into the air outlet channel 12 due to oil sloshing during refueling.

[0029] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on the explanation herein, those skilled in the art can conceive of other specific embodiments of this utility model without creative effort, and these embodiments will all fall within the scope of protection of this utility model.

Claims

1. A fuel level valve, comprising: The valve housing (1) has a cavity inside. The valve housing (1) has an external flow inlet (11) and an outlet flow channel (12). The external flow inlet (11) is located at the top of the side of the cavity, and the outlet flow channel (12) is connected to the top of the cavity. The inner cylinder (2) is located inside the cavity. The inner cylinder (2) has a valve chamber and an inner flow channel inlet (20) on its side wall. The upper end of the side wall of the inner cylinder (2) has a first exhaust port (21). The bottom of the valve chamber has a leakage hole (41). The float (3) is slidably disposed in the valve cavity, and the upper end of the float (3) is provided with a sealing plug (31) corresponding to the air outlet passage (12). Its features are: The upper end of the inner cylinder (2) is open and a ventilation gap (23) is provided between the upper end of the inner cylinder (2) and the top of the cavity.

2. The fuel level valve according to claim 1, characterized in that: The top of the cavity is provided with a flange (13), which is located between the ventilation gap (23) and the external flow channel inlet (11). The flange (13) is used to isolate the external flow channel inlet (11) and the ventilation gap (23) in the radial direction.

3. A fuel level valve according to claim 1, characterized in that: The first exhaust port (21) is circumferentially offset from the outer flow channel inlet (11).

4. A fuel level valve according to claim 1, characterized in that: The valve housing (1) includes an outer cylinder (14) with a bottom opening, a cavity located inside the outer cylinder (14), an outer flow channel inlet (11) on the outer cylinder (14), and a bottom cover (4) connected to the open end of the outer cylinder (14). The inner cylinder (2) is integrally mounted on the bottom cover (4), and the bottom cover (4) is used to limit the bottom range of the cavity and the valve chamber.

5. A fuel level valve according to claim 4, characterized in that: The valve body (1) also includes a connecting plate (15) and a connector (16) integral with the outer cylinder (14). The connecting plate (15) and the connector (16) are disposed above the outer cylinder (14). The connecting plate (15) is used to connect to the oil tank, and the air outlet passage (12) is disposed inside the connector (16).

6. A fuel level valve according to claim 1, characterized in that: The inner cylinder (2) has a second exhaust port (22) on its side wall, and the second exhaust port (22) is positioned opposite to the outer flow channel inlet (11).

7. A fuel level valve according to claim 6, characterized in that: The number of second exhaust ports (22) opposite to each external flow channel inlet (11) is at least 2.

8. A fuel level valve according to claim 6, characterized in that: The second exhaust port (22) extends obliquely on the side wall of the inner cylinder (2) such that the outer end of the second exhaust port (22) is higher than the inner end.

9. A fuel level valve according to claim 1, characterized in that: The size of the ventilation gap (23) is between 0.3 mm and 1 mm.

10. A fuel level valve according to claim 1, characterized in that: The inlet (20) of the inner flow channel is located at the bottom of the side wall of the inner cylinder (2).

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