Fuel tank cap

Abstract

The utility model relates to an oil tank cover which comprises a top cover and a breather valve located in the top cover and in interference connection with the top cover. A groove is formed in the inner surface of the top cover and extends to the bottom end of the top cover; the breathing valve is provided with a plurality of breathing openings which extend from the same point to the circumferential direction of the breathing valve; when the breather valve is in the first state, the breathing opening is in an open state, and the breathing opening and the groove jointly form a ventilation channel. When the breather valve is in the second state, the breathing opening is in the closed state, and the ventilation channel is closed. The ventilation channel is crucial, so that pressure difference inside and outside the oil tank can be avoided; the breathing opening is in an open state under the gravity state, when a vehicle jolts or the fuel tank inclines laterally and fuel bursts to the fuel opening, the breathing opening is contracted and closed, the fuel tank cover is completely sealed at the moment, and the fuel is prevented from leaking out of the ventilation channel. When the vehicle does not jolt any more or the fuel tank does not roll any more, the breathing opening recovers the opening state in the natural state, and the ventilation channel is opened again.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid container components, in particular to a fuel tank cover. Background Art

[0002] Fuel is a volatile liquid and can be dangerous. The fuel tank cap covers the tank opening and prevents foreign matter (such as dust and water) from entering the tank. Dust entering the tank can contaminate the fuel and potentially clog the fuel filter, affecting the proper fuel supply and, in turn, engine performance. Water entering the tank is even more serious because the mixture of water and gasoline can cause the engine to jitter, become difficult to start, and even damage internal engine components. For example, on rainy days or when driving through flooded roads, if the fuel tank cap is not properly sealed, water can enter the tank.

[0003] Application number: 201510618053.4, filing date: September 25, 2015. The invention is titled "Anti-slip Fuel Tank Cap." This invention discloses an anti-slip fuel tank cap, comprising a fuel pipe joint and a fuel tank cap. The bottom of the fuel pipe joint is connected to a fuel pipe, the fuel pipe joint is provided with an oil inlet channel, the top of the fuel pipe joint is provided with a connecting surface, and the outer wall of the fuel pipe joint is provided with a fixing groove surrounding the fuel pipe joint. The fuel tank cap includes a fixing portion, the top of the fixing portion is provided with a gripping portion, the fixing portion is provided at the bottom of the fuel tank cap, and the fixing portion is provided with a limiting device. The limiting device includes a clamping block and an anti-rotation block. The clamping block is connected to the anti-rotation block. The anti-rotation block is trapezoidal and has an abutting surface connected to the clamping block, the abutting surface being connected to an inclined surface. This invention effectively improves the stability of the fuel tank cap, prevents the fuel tank cap from slipping due to loosening, and prevents the difficulty of opening the fuel tank cap due to excessive rotation of the fuel tank cap.

[0004] While the conventional fuel tank cap provides a seal, as fuel is consumed, a vacuum gradually forms inside the tank. This vacuum creates inward pressure on the tank walls, potentially causing dents and cracks in some plastic tanks. Metal tanks can also be damaged by this uneven pressure over time. Utility Model Content

[0005] In view of the defect of the above-mentioned prior art fuel tank cap that a vacuum is formed inside the fuel tank, resulting in a pressure difference between the inside and outside of the fuel tank, the purpose of the present utility model is to provide a fuel tank cap that can achieve a fuel tank sealing effect and balance the pressure difference between the inside and outside of the fuel tank.

[0006] The technical solution provided by this utility model is:

[0007] A fuel tank cap comprises a top cover and a breathing valve located inside the top cover and interference-connected with the top cover;

[0008] The inner surface of the top cover is provided with a groove, and the groove extends to the bottom end of the top cover;

[0009] The breather valve is provided with a plurality of breathing ports, and the plurality of breathing ports extend from the same point to the circumference of the breather valve;

[0010] The breather valve includes two states.

[0011] When the breather valve is in the first state, the breathing ports are in an open state, and the breathing ports and the groove jointly form a gas permeation channel.

[0012] When the breather valve is in the second state, the breathing ports are in a closed state, and the gas permeation channel is closed.

[0013] Further, the breather valve is made of a flexible material and includes a circular ring part and a breather valve body, and the circular ring part is fixedly connected to the breather valve body through a curved surface.

[0014] The breathing ports are arranged on the breather valve body, and the intersection point of the breathing ports is the central axis of the breather valve body.

[0015] The outer diameter of the breather valve body is not greater than the inner diameter of the oil port.

[0016] Further, the breather valve body is convex to the side away from the top cover, and when the breather valve body is contracted toward the top cover, the breather valve changes from the first state to the second state.

[0017] Further, the breathing ports are in a strip shape, one end of which is closed, the other end of which is open, and the other end is in communication with the adjacent breathing port, and the communication point is located at the center of the breather valve body.

[0018] Further, the top cover includes a cover body and a screwing part fixedly connected to the circumference of the cover body and located below the cover body.

[0019] The screwing part is hollow, and the inner surface thereof is provided with an internal thread, and the internal thread is disconnected at the groove.

[0020] The outer wall of the oil port is provided with an external thread matched with the internal thread of the screwing part.

[0021] Further, the internal thread is convex to the central axis of the screwing part, and the circular ring part is located between the internal thread and the cover body, and the outer diameter of the circular ring part is greater than the inner diameter of the screwing part.

[0022] Further, the inner surface of the cover body is provided with a labyrinth ring, and the labyrinth ring includes a first ring, a second ring, and a third ring from inside to outside.

[0023] The projection of the labyrinth ring on the cover body is a concentric circle, the center of the concentric circle is located on the central axis of the cover body, and the center is point O.

[0024] The first ring is provided with a first opening, and the projection center point of the first opening on the cover body is point A;

[0025] The second ring is provided with a second opening, and the projection center point of the second opening on the cover body is point B;

[0026] The third ring is provided with a third opening, and the projection center point of the third opening on the cover body is point C;

[0027] The angle between the lines OA and OB is 120° to 180°, and the angle between the lines OB and OC is 120° to 180°.

[0028] Furthermore, when the breathing valve body contracts in a direction close to the top cover, the breathing valve body abuts against the labyrinth ring; the labyrinth ring is used to prevent the breathing port from opening in the reverse direction.

[0029] Furthermore, the inner surface of the cover body is also provided with an outer ring located outside the labyrinth ring; the outer ring is provided with a plurality of outer ring openings; the outer ring openings correspond to the positions of the grooves; and the third opening is located between two adjacent outer ring openings.

[0030] Furthermore, the groove includes a radial groove, the starting point of the radial groove is located at the outer ring opening, and the radial groove extends outward to the junction of the cover body and the screwing portion.

[0031] Furthermore, the groove further includes an axial groove, the starting point of the axial groove is the end point of the radial groove, and the axial groove extends downward to the bottom of the screwing portion.

[0032] Furthermore, the tangent line at the center of the outer ring opening is perpendicular to the radial groove, and the width of the outer ring opening is consistent with the slot width of the radial groove.

[0033] Furthermore, the axial groove is parallel to the central axis of the screwing portion, and the groove width and groove depth of the axial groove are consistent with those of the radial groove.

[0034] Furthermore, along the central axis direction of the screwing portion, the height of the curved surface is not less than the height of the labyrinth ring, and the inner diameter of the curved surface is not less than the outer diameter of the outer ring.

[0035] Compared with the prior art, the technical solution provided by this utility model has the following beneficial effects:

[0036] (1) The present invention provides a breathing port on the breathing valve and a corresponding groove on the top cover, so that the breathing port and the groove together form a ventilation channel. The provision of the ventilation channel is crucial to avoid pressure differences between the inside and outside of the fuel tank.

[0037] (2) The vent is open under gravity. When the vehicle is bumpy or the fuel tank tilts, and fuel flows into the fuel port, the vent contracts and closes. At this time, the fuel tank cap is completely sealed to prevent fuel from leaking from the vent channel. When the vehicle is no longer bumpy or the fuel tank no longer tilts, the vent returns to its open state under natural conditions, and the vent channel opens again.

[0038] (3) The top cover is equipped with a labyrinth ring. When the breathing port is contracted and closed, the labyrinth ring presses against the breathing valve, preventing the breathing valve from bulging in the opposite direction under the action of fuel thrust, causing the breathing port to open in the opposite direction. Even if a small amount of fuel enters the top cover, the labyrinth ring continuously changes the direction of the channel, causing the fuel to continuously change direction and speed during the flow process, so that the energy of the fuel is gradually consumed, thereby greatly reducing the possibility of fuel leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the overall structure of the fuel tank cover in one embodiment of the present application;

[0040] Figure 2 This is a schematic diagram of the overall structure of the inner side of the fuel tank cover in one embodiment of the present application;

[0041] Figure 3 This is a schematic diagram of the breathing port structure in one embodiment of the present application;

[0042] Figure 4 This is a schematic diagram of the external thread structure of the oil port in one embodiment of the present application;

[0043] Figure 5 This is a schematic diagram of the overall structure of a breathing valve in one embodiment of the present application;

[0044] Figure 6 This is a schematic diagram of the specific position of the breathing port on the breathing valve in one embodiment of the present application;

[0045] Figure 7 This is a schematic diagram of the breathing port in an open state in one embodiment of the present application;

[0046] Figure 8 This is a schematic diagram of the breathing port closed state in one embodiment of the present application;

[0047] Figure 9 This is a schematic diagram of the labyrinth ring structure inside the top cover in one embodiment of the present application;

[0048] Figure 10 This is a schematic diagram of the internal thread and groove structure of the top cover in one embodiment of the present application.

[0049] Explanation of the numbers in the schematic diagram:

[0050] Breathing valve 1, breathing port 11, annular portion 12, breathing valve body 13, curved surface 14;

[0051] Top cover 2, cover body 21, screwing portion 22, outer ring 210, first ring 211, second ring 212, third ring 213, radial groove 214, axial groove 215, recessed portion 221, first opening 2111, second opening 2121, third opening 2131, outer ring opening 2101;

[0052] Oil port 3. DETAILED DESCRIPTION

[0053] In order to further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings and embodiments.

[0054] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in this specification for understanding and reading by those familiar with this technology. They are not used to limit the conditions for implementation of the utility model and therefore have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in this utility model without affecting the efficacy and purpose of the utility model. At the same time, terms such as "upper", "lower", "left", "right", and "middle" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation. Changes or adjustments in their relative relationships should also be considered as the scope of implementation of the utility model without substantially changing the technical content.

[0055] Fuel tank caps typically use a rubber sealing ring to achieve a seal. This ring is attached to the edge of the fuel tank cap. When the cap is closed, it fits snugly against the fuel tank opening. The rubber material has excellent elasticity, allowing it to fill the slight gap between the fuel tank opening and the cap. Furthermore, the ring's shape and dimensions are designed to match the structure of the tank opening and the cap to ensure maximum sealing. For example, on some car fuel tank caps, the ring is annular, with high precision in its inner and outer diameters, ensuring a tight fit around the edge of the tank opening.

[0056] Fuel tanks need ventilation because the pressure inside the tank changes with ambient temperature and fuel consumption. When the temperature rises, the fuel expands, causing the pressure inside the tank to increase; as the fuel is consumed, the pressure inside the tank decreases. If the fuel tank is completely sealed and airtight, it could rupture if the pressure increases; and it could collapse under the external atmospheric pressure if the pressure decreases. Ventilation balances the pressure inside and outside the tank, ensuring proper operation.

[0057] Existing technology generally uses a small vent hole to balance the air pressure inside and outside the fuel tank. This hole contains a one-way valve structure. When the pressure inside the fuel tank increases, the valve is pushed open to release the gas; when the pressure returns to normal, the valve closes to prevent external impurities from entering the fuel tank.

[0058] However, when the vent is clogged, outside air cannot enter, and the negative pressure in the fuel tank will increase. This can cause the fuel pump to operate with difficulty, as it must overcome a greater pressure difference to draw fuel. In severe cases, the fuel pump may not be able to pump fuel properly, causing the engine to experience fuel starvation. For example, the car may experience a loss of power, weak acceleration, or even engine jitter or stalling while driving.

[0059] Temperature fluctuations also significantly affect fuel tanks. When ambient temperature rises, the fuel in the tank expands. Normally, the excess gas generated by this expansion is discharged through the vents, keeping the internal pressure within the tank within a safe range.

[0060] However, if the vent is clogged, the pressure inside the tank will rise dramatically as the fuel expands. Without a way to release the pressure, the tank may deform. This deformation may be a localized bulge or the entire tank may swell. Fuel tank deformation not only damages the tank structure itself but can also affect the proper connection and operation of connected components, such as fuel lines and pumps.

[0061] The fuel tank cap of the present application includes a breathing valve 1 and a top cover 2. The breathing valve 1 is tightly attached to the inner surface of the top cover 2, and the two are interference-connected so that the breathing valve 1 will not loosen.

[0062] The breathing valve 1 comprises a circular portion 12, a valve body 13, and a curved surface 14. One function of the curved surface 14 is to securely connect the circular portion 12 and the valve body 13. Preferably, the circular portion 12, the valve body 13, and the curved surface 14 are integrally formed and made of a flexible material. This flexible material allows the circular portion 12 to achieve an interference fit with the top cover 2, while also enabling the valve body 13 to function as an open and close mechanism.

[0063] The breathing valve body 13 is provided with a plurality of breathing ports 11, which intersect at a point, preferably the central axis of the breathing valve body 13. The breathing ports 11 are preferably elongated, with one end closed and the other open, and connected to adjacent breathing ports 11. That is, the connection point is open, and the location of the connection point is preferably the center point of the breathing valve body 13.

[0064] Under gravity, the breathing valve body 13 protrudes toward the side away from the top cover 2. Three breathing ports 11 are preferably provided, with the angle between two adjacent breathing ports 11 being 60°. Under gravity, the gap between the breathing ports 11 is 1.5mm to 3mm. More than three breathing ports 11 are permitted; the larger the number, the smaller the gap between each breathing port 11.

[0065] In addition, the outer diameter of the breathing valve body 13 is not larger than the inner diameter of the oil port 3, so that when the fuel tank cap is closed, the breathing valve body 13 is located inside the fuel tank port.

[0066] The inner surface of the top cover 2 is provided with a groove that extends all the way to the bottom of the top cover 2. Specifically, when the breathing port 11 is open under gravity, the breathing port 11 and the groove together form a ventilation channel. During normal vehicle operation, the fuel gradually decreases and the fuel level gradually drops. Thanks to the ventilation channel, air can enter the fuel tank, balancing the pressure inside and outside the tank, preventing the tank from denting or damaging.

[0067] When the fuel in the tank flows to the oil port 3, the breathing valve body 13 contracts toward the top cover 2 under the thrust of the fuel liquid, the breathing port 11 is in a closed state, and the air vent is closed to prevent the fuel from leaking from the air vent, thereby avoiding the fuel tank from tilting when the vehicle passes through bumpy roads or crosses ridges between fields, thereby causing the fuel to flow out of the air vent.

[0068] More specifically, the top cover 2 includes a cover body 21 and a screwing portion 22. The screwing portion 22 is circumferentially fixedly connected to the cover body 21 and is located below the cover body 21. Preferably, the screwing portion 22 and the cover body 21 are integrally formed. The screwing portion 22 is hollow and has an internal thread on its inner surface. The outer wall of the oil port 3 has an external thread. The internal and external threads cooperate to tighten the fuel tank cap to the outside of the oil port 3. It is important to note that the internal thread is interrupted at the groove in the top cover 2 to avoid interference with the ventilation channel and achieve atmospheric balance inside and outside the fuel tank.

[0069] It should be noted that the internal thread protrudes toward the center axis of the screwing portion 22, and the outer diameter of the annular portion 12 is larger than the inner diameter of the screwing portion 22. Therefore, the protruding internal thread clamps the annular portion 12 at the top, further preventing the annular portion 12 from loosening.

[0070] A labyrinth ring is provided in the middle of the inner surface of the cover body 21. The labyrinth ring includes a first ring 211, a second ring 212 and a third ring 213 from the inside to the outside. The projections of these three rings on the cover body 21 are concentric circles, and the center of the circle should be located on the central axis of the cover body 21. The center of the circle is marked as point O.

[0071] The first ring 211 is provided with a first opening 2111, and the center point of the projection of the first opening 2111 on the cover body 21 is marked as point A. Similarly, the second ring 212 is provided with a second opening 2121, and the center point of the projection of the second opening 2121 on the cover body 21 is marked as point B. The third ring 213 is provided with a third opening 2131, and the center point of the projection of the third opening 2131 on the cover body 21 is marked as point C. The angle between the lines OA and OB is 120°-180°, and the angle between the lines OB and OC is 120°-180°.

[0072] That is, the opening position of a certain ring is basically opposite to the opening position of the ring adjacent to the outside of the ring. The advantage of this design is that the fuel flow path is lengthened. In addition, the clear distance between each ring is preferably the same, and the width of the opening is preferably about 2 mm.

[0073] If the size of the fuel tank cap is increased, a fourth ring, a fifth ring, and the like can be continuously provided. If the size of the fuel tank cap is small, at least two rings should be provided.

[0074] When the vehicle passes through a bumpy road section or crosses a ridge between fields, fuel rushes to the oil port 3. At this time, the breather port 11 is contracted upward under the thrust of the fuel liquid, thereby being closed. At this time, the breather valve 1 abuts against the labyrinth ring. If the breather valve 1 does not abut against the labyrinth ring, the breather port 11 is easily opened in the reverse direction when the thrust of the fuel liquid is too large, so that fuel leaks from the breather passage.

[0075] The outer side of the labyrinth ring is further provided with an outer ring 210. The outer ring 210 is provided with a plurality of outer ring openings 2101. The outer ring openings 2101 correspond to the groove positions, and the opening of the outermost ring of the labyrinth ring is located between two outer ring openings 2101. Taking the case where the labyrinth ring has three rings as an example, the third opening 2131 of the third ring 213 is located between two outer ring openings 2101, and it is best that the third opening 2131 is centered between the two outer ring openings 2101.

[0076] More specifically, the outer ring openings 2101 are preferably four, and the distance between any adjacent outer ring openings 2101 is equal, that is, the outer ring openings 2101 are uniformly distributed on the outer ring 210.

[0077] The grooves include a radial groove 214 and an axial groove 215. The starting point of the radial groove 214 is located at the outer ring opening 2101 and extends outward to the junction of the cover body 21 and the screwing portion 22. The tangent line of the circle at the center of the outer ring opening 2101 is perpendicular to the radial groove 214, and the width of the outer ring opening 2101 is consistent with the slot width of the radial groove 214.

[0078] The starting point of the axial groove 215 is connected to the end point of the radial groove 214, and the axial groove 215 extends downward to the bottom of the screwing part 22. The extension direction of the axial groove 215 is preferably parallel to the central axis of the screwing part 22, and the groove width and groove depth of the axial groove 215 and the radial groove 214 should be consistent.

[0079] Along the central axis direction of the screwing portion 22, the height of the labyrinth ring should be consistent with the height of the outer ring 210, and the height of the curved surface 14 should not be less than the height of the labyrinth ring. At the same time, the inner diameter of the curved surface 14 should not be less than the outer diameter of the outer ring 210, so that after the fuel tank cap is screwed, the labyrinth ring is located inside the curved surface 14.

[0080] A labyrinth ring is a special sealing structure that prevents liquid or gas leaks through a series of continuous annular channels and barriers. When fuel attempts to overflow the tank due to sloshing, vehicle tilt, or other factors, it must flow through the ring's complex channels. These channels lengthen the fuel's flow path, and because the channels constantly change direction, the fuel constantly changes direction and speed during flow. This complex path and directional changes gradually dissipate the fuel's energy, significantly reducing the likelihood of leaks.

[0081] In addition, since the fuel has a certain volatility, the vaporized fuel contacts the labyrinth ring on the top during the upward evaporation process, can be liquefied again, and then return to the fuel tank downward.

[0082] The outer surface of the screwing portion 22 is provided with a plurality of recessed portions 221, and the recessed portions 221 can be provided with anti-slip grooves as needed. Preferably, the recessed portions 221 are evenly distributed on the outer surface of the screwing portion 22. The purpose of providing the recessed portions 221 is to facilitate the screwing of the fuel tank cap and avoid the situation where the fuel tank cap is difficult to tighten after being stuck with oil.

[0083] The utility model realizes the balance of air pressure inside and outside the fuel tank by setting up the air vent channel through the above technical solution. In case of an accident, the fuel tank cover can be completely sealed by closing the air vent channel to prevent fuel leakage.

[0084] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by this and, without departing from the inventive purpose of the present invention, designs a structure and embodiment similar to the technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A fuel tank cap, characterized in that: It comprises a top cover (2) and a breathing valve (1) located inside the top cover (2) and interference-connected therewith; The inner surface of the top cover (2) is provided with a groove, and the groove extends to the bottom end of the top cover (2); The breathing valve (1) is provided with a plurality of breathing ports (11), and the plurality of breathing ports (11) extend circumferentially from the same point toward the breathing valve (1); Wherein, the breathing valve (1) includes two states; When the breathing valve (1) is in the first state, the breathing port (11) is in an open state, and the breathing port (11) and the groove together form a ventilation channel; When the breathing valve (1) is in the second state, the breathing port (11) is in a closed state, and the air permeability channel is closed.

2. The fuel tank cap according to claim 1, characterized in that: The breathing valve (1) is made of a flexible material and comprises a circular ring portion (12) and a breathing valve body (13); the circular ring portion (12) and the breathing valve body (13) are fixedly connected via a curved surface (14); The breathing port (11) is provided on the breathing valve body (13), and the intersection of the breathing port (11) is the central axis of the breathing valve body (13); The outer diameter of the breathing valve body (13) is not larger than the inner diameter of the oil port (3).

3. The fuel tank cap according to claim 2, characterized in that: The breathing valve body (13) protrudes toward a side away from the top cover (2), and when the breathing valve body (13) contracts toward the top cover (2), the breathing valve (1) changes from the first state to the second state.

4. The fuel tank cap according to claim 2, characterized in that: The breathing port (11) is in the shape of an elongated strip, one end of which is closed and the other end is open, and is connected with the adjacent breathing port (11), and the connection point is located at the center of the breathing valve body (13).

5. The fuel tank cap according to claim 2, characterized in that: The top cover (2) comprises a cover body (21) and a screwing portion (22) circumferentially fixedly connected to the cover body (21) and located below the cover body (21); The screwing portion (22) is hollow, and an inner surface thereof is provided with an internal thread, and the internal thread is disconnected at the groove; The outer wall of the oil port (3) is provided with an external thread that matches the internal thread of the screwing portion (22).

6. The fuel tank cap according to claim 5, characterized in that: The internal thread protrudes toward the central axis of the screwing portion (22), and the annular portion (12) is located between the internal thread and the cover body (21); the outer diameter of the annular portion (12) is larger than the inner diameter of the screwing portion (22).

7. The fuel tank cap according to claim 5, characterized in that: The inner surface of the cover body (21) is provided with a labyrinth ring, and the labyrinth ring comprises a first ring (211), a second ring (212) and a third ring (213) from the inside to the outside; The projection of the labyrinth ring on the cover body (21) is a concentric circle, the center of the concentric circle is located on the central axis of the cover body (21), and the center is point O; The first ring (211) is provided with a first opening (2111), and the projection center point of the first opening (2111) on the cover body (21) is point A; The second ring (212) is provided with a second opening (2121), and the projection center point of the second opening (2121) on the cover body (21) is point B; The third ring (213) is provided with a third opening (2131), and the projection center point of the third opening (2131) on the cover body (21) is point C; The angle between the lines OA and OB is 120° to 180°, and the angle between the lines OB and OC is 120° to 180°.

8. The fuel tank cap according to claim 7, characterized in that: When the breathing valve body (13) contracts in a direction close to the top cover (2), the breathing valve body (13) abuts against the labyrinth ring; the labyrinth ring is used to prevent the breathing port (11) from opening in the reverse direction.

9. The fuel tank cap according to claim 7, characterized in that: The inner surface of the cover body (21) is further provided with an outer ring (210) located outside the labyrinth ring; the outer ring (210) is provided with a plurality of outer ring openings (2101); The outer ring opening (2101) corresponds to the position of the groove; The third opening (2131) is located between two adjacent outer ring openings (2101).

10. The fuel tank cap according to claim 9, characterized in that: The groove comprises a radial groove (214), the starting point of the radial groove (214) is located at the outer ring opening (2101), and the radial groove (214) extends outward to the junction of the cover body (21) and the screwing portion (22).

11. The fuel tank cap according to claim 10, characterized in that: The groove further comprises an axial groove (215), the starting point of the axial groove (215) being the end point of the radial groove (214), and the axial groove (215) extending downward to the bottom of the screwing portion (22).

12. The fuel tank cap according to claim 10, characterized in that: The tangent line at the center of the outer ring opening (2101) is perpendicular to the radial groove (214), and the width of the outer ring opening (2101) is consistent with the slot width of the radial groove (214).

13. The fuel tank cap according to claim 11, characterized in that: The axial groove (215) is parallel to the central axis of the screwing portion (22), and the groove width and groove depth of the axial groove (215) and the radial groove (214) are consistent.

14. The fuel tank cap according to claim 8, characterized in that: Along the central axis direction of the screwing portion (22), the height of the curved surface (14) is not less than the height of the labyrinth ring, and the inner diameter of the curved surface (14) is not less than the outer diameter of the outer ring (210).

Images