A fuel tank vent valve

Abstract

The present invention discloses a fuel tank exhaust valve. A first exhaust port is opened on the valve body, and a spool part is slidably arranged in the valve body; an active sealing part is arranged on the spool part, and a second exhaust port corresponding to the first exhaust port is arranged on the active sealing part. When closed, the spool part rises, driving the active sealing part to rise and fit against the top surface of the spool accommodating cavity, closing the first exhaust port. At this time, the first exhaust port is communicated with the second exhaust port; the spool part continues to rise and fits against the second side surface of the active sealing part, closing the second exhaust port to complete the overall closing. When it needs to be opened, the flow area of the second exhaust port is small, so it is easier to open under higher pressure; the spool sinks, causing the spool part to tear away from the active seal, and the second exhaust port opens; as the pressure further decreases, the spool continues to sink, driving the active sealing part to disengage from the spool accommodating cavity to complete the overall opening. The problem that the existing fuel tank exhaust valve cannot be reopened under high pressure is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of valves, and particularly relates to a fuel tank exhaust valve. Background Art

[0002] The fuel tank exhaust valve is installed on the top of the fuel tank assembly. In the traditional fuel tank exhaust valve technology, when the vehicle is running normally, the exhaust valve is always open to discharge fuel vapor. However, when the vehicle tips over or rolls over, the exhaust valve automatically closes. The exhaust valve in the National VI technology: Under normal circumstances, it allows fuel vapor to flow from the fuel tank to the carbon canister to prevent excessive positive pressure in the fuel tank; during operation and refueling, if the pressure in the fuel tank is high enough, the head valve opens to allow more fuel vapor to flow from the fuel tank to the carbon canister; during carbon canister desorption, it allows fresh air to be supplemented into the fuel tank through the carbon canister to prevent excessive negative pressure in the fuel tank; in special cases, when encountering a rollover or a large-angle tilt, the exhaust valve is closed to prevent fuel leakage.

[0003] At present, the sealing structure of the fuel tank exhaust valve on the market seals through two planes, and the exhaust port is designed to be relatively large, which results in a relatively low opening pressure point of the valve. In addition, the sealing structure seals through two planes, which requires very high flatness, surface finish of the float and the valve body, and parallelism after the installation of the two planes to achieve a better sealing effect. However, in the actual production and manufacturing process, it is impossible to meet the good flatness, surface finish and parallelism after the installation of the two planes. Therefore, the sealing performance of this structure is poor, and the safety factor is low. At the same time, the defective rate of production increases, the scrap rate of the product increases, and the manufacturing cost is relatively high. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a fuel tank exhaust valve to solve the problem that the existing fuel tank exhaust valve has a relatively low opening pressure point and cannot be reopened under high pressure.

[0005] To solve the above problems, the technical solution of the present invention is as follows:

[0006] A fuel tank exhaust valve of the present invention includes a valve body, a valve core part, and a movable sealing part;

[0007] A valve core accommodating cavity is provided inside the valve body; an inflow channel communicating the valve core accommodating cavity with the external space of the valve body is provided on the valve body; a first discharge port communicating with the valve core accommodating cavity is provided at the upper end of the valve body;

[0008] The valve core part is slidably connected inside the valve core accommodating cavity;

[0009] The movable sealing part is movably connected to the valve core part and is located between the valve core part and the first discharge port; the surface of the movable sealing part facing the first discharge port is the first side surface, and the surface of the movable sealing part facing the valve core part is the second side surface;

[0010] The movable sealing portion is provided with a second discharge outlet communicating the first side surface and the second side surface, the second discharge outlet corresponds to the first discharge outlet, and the flow area of the second discharge outlet is smaller than that of the first discharge outlet;

[0011] Wherein, the first side surface is used to cooperate with the top surface of the valve core accommodating cavity to close the first discharge outlet, and when the first discharge outlet is closed, the first discharge outlet communicates with the second discharge outlet; the second side surface is used to cooperate with the upper end of the valve core portion to close the second discharge outlet.

[0012] For the fuel tank exhaust valve of the present invention, the movable sealing portion further includes a first sealing member and a second sealing member;

[0013] The first sealing member is disposed on the first side surface or the top surface of the valve core accommodating cavity, and corresponds to the first discharge outlet, and is used to cooperate with the movable sealing portion to close the first discharge outlet;

[0014] The second sealing member is disposed on the second side surface or the top surface of the valve core portion, and corresponds to the second discharge outlet, and is used to cooperate with the movable sealing portion to close the second discharge outlet.

[0015] For the fuel tank exhaust valve of the present invention, a plurality of convex blocks are provided on the top surface of the valve core portion, the height of the convex blocks is smaller than the height of the second sealing member, and the convex blocks are arranged around the second sealing member.

[0016] For the fuel tank exhaust valve of the present invention, the movable sealing portion includes a movable connecting member and a flexible sealing member;

[0017] The first end of the movable connecting member is movably connected to the valve core portion, and the second end of the movable connecting portion is connected to the flexible sealing member;

[0018] The second discharge outlet is formed on the flexible sealing member.

[0019] For the fuel tank exhaust valve of the present invention, the movable connecting member and the flexible sealing member are processed by a secondary plastic coating process.

[0020] For the fuel tank exhaust valve of the present invention, a connecting shaft is provided on the valve core portion; a connecting groove sleeving the connecting shaft is provided at the first end of the movable connecting member, and the size of the opening of the connecting groove is smaller than the diameter of the connecting shaft.

[0021] For the fuel tank exhaust valve of the present invention, the inflow channel includes a first channel and a second channel; the first channel is disposed at the bottom of the valve body; the second channel is disposed on the side wall of the valve body.

[0022] For the fuel tank exhaust valve of the present invention, a recessed cavity is formed on the bottom surface of the valve body, and the first channel is opened on the bottom surface of the recessed cavity.

[0023] For the fuel tank exhaust valve of the present invention, the valve core part includes a float and an elastic member; the float is engaged and slidably connected with the rib grooves on the inner side surface of the valve core accommodating cavity; both ends of the elastic member are respectively connected with the float and the valve core accommodating cavity.

[0024] The fuel tank exhaust valve of the present invention further includes a pressure maintaining part, which is arranged at the upper end of the valve body, and the input end of the pressure maintaining part is communicated with the first discharge port.

[0025] For the fuel tank exhaust valve of the present invention, the pressure maintaining part includes a pressure maintaining shell and a pressure maintaining cover; a pressure maintaining cavity is arranged inside the pressure maintaining shell, and an inflow hole and a discharge hole communicated with the pressure maintaining cavity are further arranged on the pressure maintaining shell; the pressure maintaining shell is arranged at the upper end of the valve body, and the inflow hole is communicated with the first discharge port; the pressure maintaining cover is slidably connected to the pressure maintaining cavity for opening and closing the inflow hole.

[0026] The fuel tank exhaust valve of the present invention further includes a shell and a flange;

[0027] The flange covers the shell and cooperates to form a valve body accommodating cavity; the valve body is accommodated in the valve body accommodating cavity and is hermetically connected with the flange and / or the shell, and the top surface of the valve body and the flange cooperate to form a fluid discharge chamber for guiding the fluid discharged from the first discharge port;

[0028] Wherein, a communication channel communicating the valve body accommodating cavity is opened on the shell.

[0029] Due to the adoption of the above technical solutions, the present invention has the following advantages and positive effects compared with the prior art:

[0030] In an embodiment of the present invention, a first row of outlet ports is opened on the valve body, and a valve core part is slidably arranged in the valve body; an active sealing part is arranged on the valve core part, and a second row of outlet ports corresponding to the first row of outlet ports is arranged on the active sealing part. When the vehicle has a large-angle tilt or rolls over, causing the valve to need to be closed, the hydraulic oil enters the valve core accommodation cavity, causing the valve core part to rise, driving the first side surface of the active sealing part to rise and fit against the top surface of the valve core accommodation cavity, realizing the closing of the first row of outlet ports. At this time, the first row of outlet ports is communicated with the second row of outlet ports; at the same time, the top surface of the valve core part also fits against the second side surface of the active sealing part, realizing the closing of the second row of outlet ports, thus completing the closing of the entire valve. And in some cases, there may be a certain pressure buildup in the fuel tank. At this time, it is necessary for the valve to be opened in time to relieve the pressure in the fuel tank. When the valve needs to be reopened, since the flow area of the second row of outlet ports is smaller than that of the first row of outlet ports, it is easier for the second row of outlet ports to open under higher pressure; the valve core sinks under the action of gravity, causing the top surface of the valve core part to tear away from the second side surface of the active seal, and the second row of outlet ports opens to release the pressure in the fuel tank; when the pressure further decreases, the valve core sinks further, driving the first side surface of the active sealing part to tear away from the top surface of the valve core accommodation cavity, thus completing the opening of the entire valve. Therefore, this embodiment solves the problem that the existing fuel tank exhaust valve has a relatively low opening pressure point and cannot be reopened under high pressure.

[0031] 2. In an embodiment of the present invention, a first seal is arranged between the first side surface of the active sealing part and the top surface of the valve core accommodation cavity, and a second seal is arranged between the second side surface of the active sealing part and the top surface of the valve core part. The first seal and the second seal respectively seal the first row of outlet ports and the second row of outlet ports. Compared with the existing sealing between planes, the sealing effect of the two rows of outlet ports can be further improved.

[0032] 3. In an embodiment of the present invention, a number of bumps with a height less than that of the second seal are arranged on the top surface of the valve core part, which can minimize the impact on the second seal and the active sealing part when closing the second row of outlet ports, and extend the service life of the valve as much as possible.

[0033] 4. In an embodiment of the present invention, the active sealing part is set as an active connecting piece and a flexible seal. The active connecting piece is used to connect with the valve core part, and the flexible seal is used to cooperate with the top surface of the valve core accommodation cavity and the top surface of the valve core part to close the first row of outlet ports and the second row of outlet ports. The setting of the flexible material makes the fit closer after extrusion, and the sealing of the first row of outlet ports and the second row of outlet ports is more reliable.

[0034] 5. In an embodiment of the present invention, the movable connection between the movable connecting piece and the valve core part is set as the connection between the connecting groove and the connecting shaft, and the opening of the connecting groove is set to be smaller so that the connecting shaft cannot be disengaged. At the same time, the dimension of the connecting groove inside the opening is set to be larger so that the movable connecting piece can move up and down relative to the valve core part to facilitate the opening of the second discharge port and the first discharge port.

[0035] 6. In an embodiment of the present invention, a concave cavity is provided on the bottom surface of the valve body, and a first channel for allowing the oil to flow into the valve core accommodating cavity is provided in the concave cavity. The concave cavity can form an air cavity to reduce the impact of the oil. At the same time, the height at which the oil flows into the valve core accommodating cavity can be increased, thereby improving the closing height of the fuel tank exhaust valve in this embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of the fuel tank exhaust valve of the present invention;

[0037] Figure 2 is another schematic diagram of the fuel tank exhaust valve of the present invention;

[0038] Figure 3 is a schematic diagram of the movable sealing part of the fuel tank exhaust valve of the present invention;

[0039] Figure 4 is a schematic diagram of the exhaust function of the fuel tank exhaust valve of the present invention;

[0040] Figure 5 is a schematic diagram of the exhaust and pressure maintaining function of the fuel tank exhaust valve of the present invention;

[0041] Figure 6 is a schematic diagram of the valve body of the fuel tank exhaust valve of the present invention being closed;

[0042] Figure 7 is a schematic diagram of the movable sealing part when the valve body of the fuel tank exhaust valve of the present invention is closed;

[0043] Figure 8 is a schematic diagram of the second discharge port of the fuel tank exhaust valve of the present invention being opened;

[0044] Figure 9 is another schematic diagram of the second discharge port of the fuel tank exhaust valve of the present invention being opened;

[0045] Figure 10 is a schematic diagram of the side of the rotating shaft of the fuel tank exhaust valve of the present invention being opened first when it is reopened;

[0046] Figure 11 is a schematic diagram of the fuel tank exhaust valve of the present invention being fully opened when it is reopened;

[0047] Figure 12This is the opening test pressure curve graph of the fuel tank exhaust valve of the present invention.

[0048] Description of the reference numerals: 1: valve body; 101: recessed cavity; 2: valve core part; 201: float; 202: elastic part; 203: connecting shaft; 204: convex block; 3: movable sealing part; 301: movable connecting part; 302: flexible sealing part; 303: connecting groove; 4: pressure maintaining part; 401: pressure maintaining shell; 402: pressure maintaining cover; 5: housing; 6: flange; 7: first discharge port; 8: second discharge port; 9: first channel; 10: second channel; 11: sealing ring; 12: first sealing part; 13: second sealing part. Detailed implementation manners

[0049] The following further describes in detail a fuel tank exhaust valve proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will be clearer according to the following description and the claims.

[0050] Embodiment 1

[0051] This embodiment is a GVV valve applied to a fuel tank, and the fluid in the fuel tank is the oil and gas in the fuel tank.

[0052] Refer to Figure 1 and Figure 2 The fuel tank exhaust valve of this embodiment includes a valve body 1, a valve core part 2, and a movable sealing part 3.

[0053] A valve core accommodating cavity is provided in the valve body 1, and the valve core part 2 is slidably connected in the valve core accommodating cavity. An inflow channel communicating the valve core accommodating cavity with the external space of the valve body 1 is provided on the valve body 1. A first discharge port 7 communicating with the valve core accommodating cavity is provided at the upper end of the valve body 1.

[0054] The movable sealing part 3 is movably connected to the valve core part 2 and is located between the valve core part 2 and the first discharge port 7. The surface of the movable sealing part 3 facing the first discharge port 7 is the first side surface, and the surface of the movable sealing part 3 facing the valve core part 2 is the second side surface. A second discharge port 8 communicating the first side surface with the second side surface is provided on the movable sealing part 3. The second discharge port 8 corresponds to the first discharge port 7, and the flow area of the second discharge port 8 is smaller than that of the first discharge port 7.

[0055] Among them, the first side surface is used to cooperate with the top surface of the valve core accommodating cavity to close the first discharge port 7, and when the first discharge port 7 is closed, the first discharge port 7 communicates with the second discharge port 8. The second side surface is used to cooperate with the upper end of the valve core part 2 to close the second discharge port 8.

[0056] In this embodiment, a first discharge port 7 is provided on the valve body 1, and a valve core part 2 is slidably arranged in the valve body 1; and an active sealing part 3 is provided on the valve core part 2, and a second discharge port 8 corresponding to the first discharge port 7 is provided on the active sealing part 3. When the vehicle tilts at a large angle or rolls over and the valve needs to be closed, the oil enters the valve core accommodating chamber, causing the valve core part 2 to rise, driving the first side surface of the active sealing part 3 to rise and fit against the top surface of the valve core accommodating chamber, thereby closing the first discharge port 7. At this time, the first discharge port 7 is connected to the second discharge port 8; at the same time, the top surface of the valve core part 2 also fits against the second side surface of the active sealing part 3, thereby closing the second discharge port 8, thereby completing the closing of the entire valve. In some cases, a certain amount of pressure may be accumulated in the fuel tank, and at this time, the valve needs to be opened in time to relieve the pressure in the fuel tank. When the valve needs to be reopened, since the flow area of the second outlet 8 is smaller than that of the first outlet 7, the second outlet 8 is easier to open under high pressure; the valve core sinks under the action of gravity, causing the top surface of the valve core part 2 to tear apart from the second side surface of the movable seal, and the second outlet 8 is opened to release the pressure in the fuel tank; when the pressure is further reduced, the valve core sinks further, driving the first side surface of the movable seal part 3 to tear apart from the top surface of the valve core accommodating cavity, thereby completing the opening of the entire valve. Therefore, this embodiment solves the problem that the existing fuel tank exhaust valve cannot be reopened under high pressure due to the low opening pressure point.

[0057] The specific structure of the fuel tank exhaust valve of this embodiment is further described below:

[0058] In this embodiment, the movable sealing portion 3 further includes a first sealing member 12 and a second sealing member 13 .

[0059] The first sealing member 12 is disposed on the first side surface or the top surface of the valve core accommodating cavity, and corresponds to the first discharge port 7, and is used to cooperate with the movable sealing portion 3 to close the first discharge port 7. The second sealing member 13 is disposed on the second side surface or the top surface of the valve core portion 2, and corresponds to the second discharge port 8, and is used to cooperate with the movable sealing portion 3 to close the second discharge port 8. By disposing the first sealing member 12 between the first side surface of the movable sealing portion 3 and the top surface of the valve core accommodating cavity, and disposing the second sealing member 13 between the second side surface of the movable sealing portion 3 and the top surface of the valve core portion 2, the first discharge port 7 and the second discharge port 8 are sealed by the first sealing member 12 and the second sealing member 13 respectively, and compared with the existing sealing between planes, the sealing effect of the two discharge ports can be further improved.

[0060] Furthermore, a plurality of bumps 204 may be provided on the top surface of the valve core portion 2, wherein the height of the bumps 204 is less than the height of the second sealing member 13, and the bumps 204 are arranged around the second sealing member 13, so as to minimize the impact on the second sealing member 13 and the movable sealing member 3 when closing the second exhaust port 8, thereby extending the life of the valve as much as possible.

[0061] See Figure 3 Figure 3 , in this embodiment, the movable seal part 3 includes a movable connecting part 301 and a flexible seal part 302. Among them, the first end of the movable connecting part 301 is movably connected to the valve core part 2, and the second end of the movable connecting part is connected to the flexible seal part 302. The second row of outlets 8 is provided on the flexible seal part 302, and the flexible seal part 302 is used to cooperate with the top surface of the valve core accommodating cavity and the top surface of the valve core part 2 to close the first row of outlets 7 and the second row of outlets 8. The setting of the flexible material makes the cooperation tighter after extrusion, and the sealing of the first row of outlets 7 and the second row of outlets 8 is more reliable.

[0062] Further, the processing technology of the movable connecting part 301 and the flexible seal part 302 can adopt the secondary overmolding process for processing. The secondary overmolding process ensures the sealing performance between the movable connecting part 301 and the flexible seal part 302. In other embodiments, other processing technologies can also be adopted, as long as the required products can be processed.

[0063] Further, regarding the connection method between the movable connecting part 301 and the valve core part 2, a connecting shaft 203 can be provided on the valve core part 2, and a connecting groove 303 for sleeving connection can be provided at the first end of the movable connecting part 301. The connecting shaft 203 can rotate and move up and down freely in the connecting groove 303, and the size of the opening of the connecting groove 303 is smaller than the diameter of the connecting shaft 203. By setting the movable connection between the movable connecting part 301 and the valve core part 2 as the connection between the connecting groove 303 and the connecting shaft 203, and setting the opening of the connecting groove 303 to be smaller, the connecting shaft 203 cannot be separated. At the same time, the size of the connecting groove 303 inside the opening is set to be larger so that the movable connecting part 301 can move up and down relative to the valve core part 2 to facilitate the opening of the second row of outlets 8 and the first row of outlets 7.

[0064] In this embodiment, the above-mentioned inflow channel includes a first channel 9 and a second channel 10. The first channel 9 is provided at the bottom of the valve body 1. The second channel 10 is provided on the side wall of the valve body 1. The two channels are used to allow the oil and gas to enter the valve core accommodating cavity under different capacities and states of the oil in the fuel tank.

[0065] Further, a recessed cavity 101 can be opened on the bottom surface of the valve body 1, and the first channel 9 is opened on the bottom surface of the recessed cavity 101. That is, a convex block 204 is provided on the bottom surface relative to the inside of the valve core accommodating cavity, and the first channel 9 is opened on the convex block 204. The recessed cavity 101 can form an air cavity to reduce the impact of the oil, and at the same time, the height of the oil flowing into the valve core accommodating cavity can be increased, thereby improving the closing height of the fuel tank exhaust valve in this embodiment.

[0066] In this embodiment, the valve core portion 2 includes a float 201 and an elastic member 202. The float 201 is engaged and slidably connected with the inner side rib grooves of the valve core accommodating cavity. Specifically, a plurality of vertical guiding ribs can be provided on the inner side surface of the valve core accommodating cavity, and corresponding guiding grooves can be provided on the float 201, so that the float 201 can slide up and down in the valve core accommodating cavity. The connecting shaft 203 can be installed on one side of the upper end of the float 201. Specifically, a notch can be provided on one side of the upper end of the float 201, and two columns can be provided in the notch and the connecting shaft 203 can be arranged on these two columns, so that the height of the connecting shaft 203 is not higher than the upper end surface of the float 201.

[0067] Both ends of the elastic member 202 are respectively connected to the float 201 and the valve core accommodating cavity. Among them, the elastic member 202 can specifically be a spring. A groove can be opened on the bottom surface of the float 201. The groove corresponds to the above-mentioned convex block 204 and has a size larger than that of the convex block 204. One end of the spring can be sleeved on the convex block 204 and connected to the bottom surface of the valve core accommodating cavity, and the other end extends into the groove on the bottom surface of the float 201 and is connected to the float 201.

[0068] In this embodiment, the fuel tank exhaust valve may further include a pressure maintaining portion 4. The pressure maintaining portion 4 is provided at the upper end of the valve body 1, and the input end of the pressure maintaining portion 4 is communicated with the first discharge port 7.

[0069] Specifically, the pressure maintaining portion 4 includes a pressure maintaining shell 401 and a pressure maintaining cover 402. A pressure maintaining cavity is provided in the pressure maintaining shell 401. The pressure maintaining shell 401 is also provided with an inflow hole and a discharge hole communicated with the pressure maintaining cavity. The pressure maintaining shell 401 is provided at the upper end of the valve body 1, and the inflow hole is communicated with the first discharge port 7. The pressure maintaining cover 402 is slidably connected to the pressure maintaining cavity and is used to open and close the inflow hole. That is, the pressure maintaining cover 402 presses on the inflow hole of the pressure maintaining cavity by its own gravity to close the inflow hole. After the gas pressure in the valve core accommodating cavity reaches a value that can offset the gravity of the pressure maintaining cover 402, the pressure maintaining cover 402 can be pushed to rise, so that the gas can enter the pressure maintaining cavity through the inflow hole and be discharged through the discharge hole.

[0070] Furthermore, the pressure maintaining shell 401 can be set as an annular protrusion and a cover plate on the top surface of the valve body 1. The annular protrusion is arranged around the first discharge port 7, and the cover plate covers the upper end of the annular protrusion, thereby forming the above-mentioned pressure maintaining cavity. A plurality of through holes are opened on the upper end of the annular protrusion or the cover plate. The through holes are the above-mentioned discharge holes, so that the gas can be discharged.

[0071] In this embodiment, the fuel tank exhaust valve may further include a housing 5 and a flange 6. Among them, the flange 6 covers the housing 5 and cooperates to form a valve body 1 accommodation cavity. The valve body 1 is accommodated in the valve body 1 accommodation cavity and is hermetically connected to the flange 6 and / or the housing 5. The top surface of the valve body 1 cooperates with the flange 6 to form a fluid discharge chamber for guiding the fluid discharged from the pressure maintaining portion 4 to the external pipeline for treatment. A communication channel communicating with the valve body 1 accommodation cavity is provided on the housing 5.

[0072] Taking a specific connection method as an example, the flange 6 and the housing 5 are snap-fitted to form the valve body 1 accommodation cavity; the valve body 1 is arranged in the valve body 1 accommodation cavity and is snap-fitted with the flange 6. The connection method between the flange 6 and the valve body 1 can be welding or other fixed connection methods. When necessary, a sealing ring 113 needs to be further used for sealing. The communication channels can be communication channels respectively opened on the bottom surface and the side surface of the housing 5. The communication channel on the side surface of the housing 5 can be opened at the connection between the housing 5 and the flange 6.

[0073] The pressure maintaining and exhaust functions of the fuel tank exhaust valve in this embodiment under different conditions will be described below:

[0074] I. When the fuel in the fuel tank is not full (the fuel in the fuel tank does not overly submerge the valve core), at this time, the float 201 of the valve core portion 2 is in a fallen state, and the movable sealing portion 3 cooperating with the float 201 does not form a seal with the first exhaust port 7 on the valve body 1. At the same time, the pressure maintaining cover 402 of the pressure maintaining portion 4 is not blown up. At this time, the gas inside the fuel tank can be discharged through the first exhaust port 7. The air flow direction is as Figure 4 shown.

[0075] II. When the fuel tank is full of fuel or when some vehicles are at a certain inclination angle, after the gravity of the internal float 201 + movable sealing portion 3 - the elastic force of the spring, the overall difference value is relatively large, and there is still a relatively large downward gravity. Therefore, the overall composed of the float 201 and the movable sealing portion 3 does not rise. So the first exhaust port of the valve body 1 is still in an open state. However, since the pressure maintaining portion 4 is provided above the first exhaust port of the valve body 1, the fuel tank exhaust valve as a whole is still in a relatively sealed state at this time. At this time, because the fuel inside the fuel tank will continuously volatilize or be affected by the rising temperature, the pressure inside the fuel tank will also continue to rise. At this time, it is necessary to timely relieve the increased pressure inside the fuel tank. When the pressure inside the fuel tank rises high enough to blow up the pressure maintaining cover 402, the pressure inside the fuel tank will decrease accordingly. The air flow will enter the valve through the small second channel 10 on the side of the base, then pass through the first exhaust port 7 of the valve body 1, pass through the exhaust channel designed in the pressure maintaining portion 4 and the pressure maintaining cavity, and then be discharged through the fluid discharge chamber formed by the flange 6. As Figure 5 shown.

[0076] The closing and sealing function of the fuel tank exhaust valve in this embodiment will be described below:

[0077] When the vehicle is in motion, there may be severe shaking or a certain inclination, and the oil in the fuel tank will also shake violently accordingly. At this time, all the first discharge outlets 7 and the second discharge outlets 8 inside the fuel tank exhaust valve need to be sealed in time to prevent the oil in the fuel tank from leaking out through the first discharge outlets 7 and the second discharge outlets 8 inside the fuel tank exhaust valve. The float 201 inside the valve core and the movable sealing part 3 will rise in time with the shaking to close the first discharge outlet 7 at the top of the valve body 1, and the float 201 will cooperate with the movable sealing part to close the second discharge outlet 8. In this way, the entire valve core will form a sealed state to prevent fuel leakage (dynamic leakage). The closed state of the fuel tank exhaust valve is as shown in Figure 6 and Figure 7 shown.

[0078] The re-opening function of the fuel tank exhaust valve in this embodiment will be described below:

[0079] Referring to Figures 8 to 11 , when the entire valve core part 2 is in the closed state (the entire valve core part 2 is closed due to the buoyancy in the fuel tank or the shaking of the fuel tank, and the valve core part 2, the movable sealing part 3 and the valve body 1 form a seal), the fuel tank may be under a certain pressure in some cases. At this time, the valve core part 2 needs to be opened in time to relieve the pressure in the fuel tank. According to P = F / S, when F is constant, the larger S is, the smaller P is. That is to say, when there is a relatively high pressure in the fuel tank, due to the relatively large cross-sectional area S of the first discharge outlet 7 on the valve body 1, it will open under a relatively low pressure. And the second discharge outlet 8 on the movable sealing part 3 is easy to open. The float 201 sinks under the action of gravity (as shown in Figure 2 ), after the float 201 sinks, it tears away from the movable sealing part 3 (as shown in Figure 3 ), the second discharge outlet 8 opens, and the system pressure gradually decreases. Subsequently, the first discharge outlet 7 sealed by the movable sealing part 3 and the valve body 1 opens. The side of the movable sealing part 3 connected to the float 201 opens first, and then opens completely (as shown in Figure 4 ) to further accelerate the relief of the pressure in the fuel tank. After the valve passage is fully opened, more gas flows out of the fuel tank to the carbon canister, and the pressure in the fuel tank decreases. The opening pressure test pressure curve of the fuel tank exhaust valve is as shown in Figure 12 shown.

[0080] Embodiment 2

[0081] On the basis of the above Embodiment 1, this embodiment further explains the first sealing member 12 and the second sealing member 13 in the above Embodiment 1.

[0082] In this embodiment, there are two ways to arrange the first seal 12. The first way is to arrange it on the top surface of the valve core accommodating cavity, and the second way is to arrange it on the flexible seal 302.

[0083] First, the first case is described: The first seal 12 can be a sealing ring extending on the top surface of the accommodating cavity of the valve body 1, and this sealing ring is sleeved on the first discharge port 7. When the float 201 drives the movable sealing part 3 to rise, the flexible seal 302 of the movable sealing part 3 will rise, and its upper surface will flexibly fit on the sealing ring, so as to realize the closing of the first discharge port 7. Of course, at this time, the closing of the first discharge port 7 is a relative closing. The second discharge port 8 is communicated with the first discharge port 7, and the gas can still be discharged through the second discharge port 8 and the first discharge port 7.

[0084] At the same time, in this case, some materials are removed from the circumferential side of the outer ring of the sealing ring on the top surface of the accommodating cavity of the valve body 1 to form a concave cavity 101, so as to avoid other parts of the movable sealing part 3, and to prevent the top surface of the movable sealing part 3 from directly hitting the top surface of the accommodating cavity of the valve body 1 when closing, resulting in poor durability of the movable sealing part 3.

[0085] The second case is described: The first seal 12 can be a flexible sealing ring extending on the flexible seal 302, and this sealing ring is relatively sleeved on the first discharge port 7. When the float 201 drives the movable sealing part 3 to rise, the flexible seal 302 of the movable sealing part 3 will rise. When it rises to a certain height, the flexible sealing ring will fit on the top surface of the accommodating cavity of the valve body 1, so as to close the first discharge port 7.

[0086] In this embodiment, there are also two ways to arrange the second seal 13. The first way is to arrange it on the lower end surface of the flexible seal 302, and the second way is to arrange it on the float 201.

[0087] First, the first case is described: The second seal 13 can be a flexible sealing ring extending on the lower surface of the flexible seal 302, and this sealing ring is sleeved on the second discharge port 8. When the float 201 drives the movable sealing part 3 to rise, the upper end of the movable seal first fits on the accommodating cavity of the valve body 1 and is limited. The float 201 continues to rise. When it rises to a certain height, the top surface of the float 201 will fit on the lower end of this flexible sealing ring, so as to realize the closing of the second discharge port 8.

[0088] Furthermore, in this case, a sealing groove corresponding to the flexible sealing ring can be opened on the top surface of the float 201. The sealing groove is designed with an inclined side surface. The lower end of the flexible sealing ring extends into the sealing groove on the float 201 and fits with the inclined side surface, so as to cooperate with the flexible sealing ring to realize the closing of the second discharge port 8.

[0089] The description of the second case is as follows: The second seal 13 can be a sealing ring extending on the top surface of the float 201, and the sealing ring is relatively sleeved on the second row of outlets 8. When the float 201 drives the movable sealing part 3 to rise, the upper end of the movable seal first fits against the accommodating cavity of the valve body 1 and is limited. The float 201 continues to rise. When it rises to a certain height, the upper end of the sealing ring on the top surface of the float 201 will fit against the lower surface of the upper flexible seal 302, thereby closing the second row of outlets 8.

[0090] Embodiment III

[0091] Based on the above Embodiment I, this embodiment further explains the flexible seal 302 and the movable connecting member 301 in the above Embodiment I.

[0092] In this embodiment, the movable connecting member 301 may include a movable connecting section, an intermediate section, and a supporting section that are connected in sequence.

[0093] Among them, the above-mentioned connecting groove 303 is formed on the movable connecting section. The cross-sectional shape of the connecting groove 303 can be circular, waist-shaped, or rectangular, as long as it satisfies that the connecting shaft 203 can move relatively up and down in the connecting groove 303, and the opening size of the connecting groove 303 is smaller than the size of the connecting shaft 203 so that the connecting shaft 203 cannot break away. No specific limitation is made here.

[0094] The intermediate section serves as an extension, so that the supporting section can be located between the first row of outlets 7 and the float 201.

[0095] The supporting section can be an annular structure, so that the flexible seal 302 can be formed within the annular structure, and the annular structure can also support the flexible seal 302. Further, a supporting inner ring can be further extended within the inner circle of the annular structure, and the supporting inner ring and the annular structure can be connected by a plurality of connecting members, so as to support the middle part of the flexible seal 302. The setting of the supporting section enables the flexible seal 302 to have a certain strength, and the basic shape of the flexible seal 302 can be supported, so that it will not be difficult to separate from the top surface of the float 201 due to its own gravity.

[0096] The above has described the embodiments of the present invention in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, provided that these changes fall within the scope of the claims of the present invention and their equivalent technologies, they still fall within the protection scope of the present invention.

Claims

1. A fuel tank exhaust valve, characterized in that, It includes a valve body, a valve core part, and a movable sealing part; A valve core accommodating cavity is provided inside the valve body; an inflow channel communicating the valve core accommodating cavity with the external space of the valve body is provided on the valve body; a first discharge port communicating with the valve core accommodating cavity is provided at the upper end of the valve body; The valve core part is slidably connected inside the valve core accommodating cavity; The movable sealing part is movably connected to the valve core part and is located between the valve core part and the first discharge port; the surface of the movable sealing part facing the first discharge port is the first side surface, and the surface of the movable sealing part facing the valve core part is the second side surface; A second discharge port communicating the first side surface with the second side surface is provided on the movable sealing part, the second discharge port corresponds to the first discharge port, and the flow area of the second discharge port is smaller than that of the first discharge port; Wherein, the first side surface is used to cooperate with the top surface of the valve core accommodating cavity to close the first discharge port, and when the first discharge port is closed, the first discharge port is communicated with the second discharge port; the second side surface is used to cooperate with the upper end of the valve core part to close the second discharge port; The movable sealing part includes a movable connecting piece and a flexible sealing piece; the first end of the movable connecting piece is movably connected to the valve core part, and the second end of the movable connecting piece is connected to the flexible sealing piece; the second discharge port is provided on the flexible sealing piece; A connecting shaft is provided on the valve core part; a connecting groove sleeving the connecting shaft is provided at the first end of the movable connecting piece, the connecting shaft is configured to freely rotate and move up and down in the connecting groove, and the size of the opening of the connecting groove is smaller than the diameter of the connecting shaft.

2. The fuel tank exhaust valve according to claim 1, wherein, The movable sealing part further includes a first sealing piece and a second sealing piece; The first sealing piece is provided on the first side surface or the top surface of the valve core accommodating cavity and corresponds to the first discharge port, and is used to cooperate with the movable sealing part to close the first discharge port; The second sealing piece is provided on the second side surface or the top surface of the valve core part and corresponds to the second discharge port, and is used to cooperate with the movable sealing part to close the second discharge port.

3. The fuel tank exhaust valve according to claim 2, characterized in that, A plurality of convex blocks are provided on the top surface of the valve core part, the height of the convex blocks is smaller than the height of the second sealing piece, and the convex blocks are arranged around the second sealing piece.

4. The fuel tank exhaust valve according to claim 1, characterized in that, The movable connecting piece and the flexible sealing piece are processed by a secondary plastic coating process.

5. The fuel tank exhaust valve according to claim 1, characterized in that, The inflow channel includes a first channel and a second channel; the first channel is provided at the bottom of the valve body; the second channel is provided on the side wall of the valve body.

6. The fuel tank exhaust valve according to claim 5, characterized in that, A concave cavity is opened on the bottom surface of the valve body, and the first channel is opened on the bottom surface of the concave cavity.

7. The fuel tank exhaust valve according to claim 1, characterized in that, The valve core part includes a float and an elastic piece; the float is in rib groove fit and slidably connected with the inner side surface of the valve core accommodating cavity; both ends of the elastic piece are respectively connected with the float and the valve core accommodating cavity.

8. The fuel tank exhaust valve according to claim 1, characterized in that, It further includes a pressure maintaining part, the pressure maintaining part is provided at the upper end of the valve body, and the input end of the pressure maintaining part is communicated with the first discharge port.

9. The fuel tank exhaust valve according to claim 8, wherein, The pressure-holding part includes a pressure-holding shell and a pressure-holding cover; a pressure-holding cavity is provided inside the pressure-holding shell, and an inflow hole and a discharge hole communicating with the pressure-holding cavity are further provided on the pressure-holding shell; the pressure-holding shell is arranged at the upper end of the valve body, and the inflow hole is communicated with the first discharge port; the pressure-holding cover is slidably connected to the pressure-holding cavity and is used for opening and closing the inflow hole.

10. The fuel tank exhaust valve according to claim 1, wherein, It further includes a shell and a flange; The flange covers the shell and cooperates to form a valve body accommodating cavity; the valve body is accommodated in the valve body accommodating cavity and is hermetically connected to the flange and / or the shell, and the top surface of the valve body and the flange cooperate to form a fluid discharge chamber for guiding the fluid discharged from the first discharge port; Wherein, a communication channel communicating with the valve body accommodating cavity is opened on the shell.

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