Split tank isolation valve

Abstract

The application discloses a split type oil tank isolation valve in the field of automobile valves, which comprises a valve shell, a tubular cavity is divided into an upper tubular cavity and a lower tubular cavity by an inner ring table, the upper tubular cavity and the lower tubular cavity are communicated through a first air hole and a second air hole in the middle of the inner ring table, an upper valve head assembly is movably arranged in the upper tubular cavity, a lower valve head assembly is movably arranged in the lower tubular cavity, an electromagnetic coil assembly is used to control the upper valve head assembly to be close to or away from the inner ring table, a bottom cover is installed at the bottom of the valve shell, a carbon tank pipeline joint communicating with the lower tubular cavity is arranged on the bottom cover, a flow limiting structure is formed on the inner wall of the bottom cover, the flow limiting structure comprises an upper air groove and a lower air groove arranged on the inner wall of the bottom cover, the gap between the upper air groove and the lower valve head assembly is larger than the gap between the lower air groove and the lower valve head assembly, and the lower valve head assembly forms a flow limiting air path with the upper air groove and the lower air groove, and the application solves the problem that the valve is closed due to excessive flow in the initial pressure relief process of the existing oil tank isolation valve.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile isolation valves, and particularly relates to an oil tank isolation valve. BACKGROUND

[0002] With the vigorous development of modern automobile industry, the control of automobile exhaust emission, fuel evaporation leakage pollution and the like has become one of the key contents in the automobile research and development process. Based on the requirements of the published GB18352.6-2016 Light-duty Vehicle Emission Control Limits and Measurement Methods (China Phase VI), the amount of volatile emission into the atmosphere of the automobile needs to be more strictly controlled. In the automobile fuel evaporation control system (EVAP), the oil gas from the fuel tank is temporarily stored in the carbon canister connected thereto, and finally enters the engine for combustion through the desorption means.

[0003] The oil tank isolation valve (FTIV valve) is controlled by a special module in the engine control system, and the system will open or close the FTIV valve according to different requirements. Generally, the FTIV valve is normally closed, which isolates the high-pressure fuel tank to form an independent sealed space, so as to ensure that the fuel evaporation oil gas cannot overflow. However, the FTIV valve must be opened under some working conditions to ensure the normal operation of other vehicle functions.

[0004] For example, when refueling, the pressure in the fuel tank needs to be released: because the FTIV valve is closed for a long time, the pressure in the fuel tank is relatively high. Therefore, when the vehicle needs to be refueled, in order to prevent the fuel from being backfired, the FTIV valve needs to be opened before the fuel tank cover is opened, and the fuel tank pressure is released to an acceptable range, and then the fuel tank cover can be opened by the driver. Through such an effective protection mechanism, the harm to personnel caused by the splashing of fuel is avoided, and it is also ensured that the fuel tank can be filled normally. The specific operation and control process is as follows: the driver triggers the refueling button to send a refueling request to the ECU, the ECU sends a control signal according to the fuel tank pressure to control the FTIV valve to open, and after the fuel tank pressure is reduced to a certain value, the fuel tank cover is released to be opened.

[0005] Generally, the time interval from the refueling request to the opening of the fuel tank cover is quite short, and the shortest is only about 1.5s. Even if the pressure of the fuel tank reaches 20 to 35kPa, the pressure of the fuel tank will be reduced to about 3kPa within 10s by opening the FTIV valve, which will not delay the driver too much time. At the same time, the vehicle manual will also specially explain this situation.

[0006] The prior art discloses an oil tank isolation valve control system, the disclosure date is: 2022.01.11, the publication number is: CN113915031A, and the deficiency lies in that: in actual use, when the pressure difference between the inside and outside of the oil tank is too large, a large instantaneous flow is generated when the FTIV valve is opened, the valve in the oil tank is closed, the oil tank cannot be exhausted, and thus oil cannot be added. SUMMARY

[0007] In view of the problems in the prior art, the present application provides a split type oil tank isolation valve, which solves the problem that the existing oil tank isolation valve has too large flow in the initial pressure relief process.

[0008] The purpose of the present application is achieved by a split type oil tank isolation valve, comprising

[0009] A valve shell is internally provided with a pipe cavity for gas flow, and the pipe cavity is divided into an upper pipe cavity and a lower pipe cavity by an inner ring table, the upper pipe cavity and the lower pipe cavity are communicated through a first air hole in the middle of the inner ring table and a second air hole in the outer periphery of the first air hole, and an oil tank pipeline joint for communicating the upper pipe cavity is arranged on the valve shell.

[0010] An upper valve head assembly is movably arranged in the upper pipe cavity, and is close to or away from the inner ring table to block or open the first and second air holes, and when blocked, the upper valve head assembly forms a first sealing surface and a second sealing surface with the inner ring table, and the second air hole is located between the first sealing surface and the second sealing surface, and a pressure relief gas path for communicating the first air hole is arranged in the upper valve head assembly.

[0011] A lower valve head assembly is movably arranged in the lower pipe cavity, and is close to or away from the upper valve head assembly to block or open the first air hole, and when blocked, a third sealing surface is formed between the inner ring tables of the lower valve head assembly.

[0012] An electromagnetic coil assembly is installed on the top of the valve shell to control the upper valve head assembly to be close to or away from the inner ring table.

[0013] A bottom cover is installed on the bottom of the valve shell, and a carbon tank pipeline joint for communicating the lower pipe cavity is arranged on the bottom cover, a flow limiting structure is processed on the inner wall of the bottom cover, the flow limiting structure comprises an upper air groove and a lower air groove opened on the inner wall of the bottom cover, the gap between the upper valve head assembly and the lower valve head assembly is greater than the gap between the lower valve head assembly and the lower air groove, and a flow limiting gas path is formed between the lower valve head assembly and the upper air groove and the lower air groove.

[0014] The present application solves the problem that the valve in the oil tank is blocked due to large flow by arranging a flow limiting structure in the bottom cover, and the working principle is as follows:

[0015] By designing upper air groove and lower air groove in the bottom cover, and the gap between the lower valve head assembly and the upper air groove is larger than the gap between the lower air groove and the lower valve head assembly, when the exhaust, the flow is calculated according to the smaller air path (the gap between the lower air groove and the lower valve head assembly), when the pressure in the oil tank is reduced, the lower valve head is gradually raised under the action of the lower spring, so that the lower valve head side part is separated from the air path limitation of the lower air groove, the conversion to the air path of the upper air groove is completed, and the large flow exhaust is started, because the pressure in the oil tank is reduced at this time, so it will not cause the valve (FLVV valve) in the oil tank to be blocked.

[0016] In order to make the up-down movement of the lower valve head assembly more stable, the inner wall of the bottom cover and the lower cavity is processed with guide ribs.

[0017] In order to facilitate the air supplement of the carbon tank to the oil tank, the upper valve head assembly comprises an upper valve head connected to the electromagnetic coil assembly, and an upper spring is further arranged between the upper valve head and the electromagnetic coil assembly, the upper spring provides a pushing force to push the upper valve head close to the inner ring table, and the pressure relief air path is arranged in the upper valve head.

[0018] In order to facilitate the assembly of the upper valve head assembly and enhance the sealing performance, the upper valve head comprises an upper sealing pad connected to the bottom of the movable frame, and the bottom of the upper sealing pad is provided with an outer ring protrusion for forming a first sealing surface and an inner ring protrusion for forming a second sealing surface.

[0019] In order to facilitate the assembly of the upper valve head assembly, the top of the movable frame is provided with a connecting part, a connecting hole is arranged on the connecting part, the electromagnetic coil assembly comprises a movable iron core arranged in the electromagnetic coil, the bottom of the movable iron core is provided with a T-shaped head, and the side of the connecting part is processed with a notch for inserting the T-shaped head.

[0020] In order to facilitate the pressure relief of the oil tank to the carbon tank, the lower valve head assembly comprises a lower valve head supported on the bottom cover by a lower spring, the lower spring provides a pushing force to push the lower valve head close to the inner ring table, the top of the lower valve head is provided with a lower sealing pad for contacting the bottom surface of the inner ring table to form a third sealing surface, and the third sealing surface is used to close the first air hole.

[0021] Compared with the prior art, the beneficial effects of the present application are that:

[0022] The present application ensures the reliability of the FLVV valve in the oil tank through the flow limiting structure, greatly improves the safety and reliability of the whole oil tank system, and the flow limiting structure can be realized only by partial improvement of the original structure without adding independent parts, thereby reducing the cost. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only aim at the embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative effort based on the provided drawings.

[0024] Figure 1 It is a schematic diagram of the external structure of the present application.

[0025] Figure 2 It is a schematic diagram of the internal structure of the present application.

[0026] Figure 3 It is a sectional view of the valve body and the bottom cover in the present application.

[0027] Figure 4 It is a partial sectional view of the upper valve head assembly and the lower valve head assembly in the present application.

[0028] Figure 5 It is a schematic diagram of the three-dimensional structure of the movable frame in the present application.

[0029] Figure 6 It is a schematic diagram of the connection between the present application and the oil tank and the carbon tank.

[0030] Figure 7 It is a gas path flow direction diagram of the working state one of the present application.

[0031] Figure 8 It is a gas path flow direction diagram of the working state two of the present application.

[0032] Figure 9 It is a gas path flow direction diagram of the working state three of the present application.

[0033] Figure 10 It is a gas path flow direction diagram of the present application when the flow limiting structure is working.

[0034] In the present application, 1 is a valve shell, 1a is an upper tube cavity, 1b is a lower tube cavity, 1c is an inner ring platform, 1d is a first air hole, 1e is a second air hole, 1f is an oil tank pipeline joint, 2 is an electromagnetic coil assembly, 2a is an electromagnetic coil, 2b is a moving iron core, 3 is a bottom cover, 3a is a carbon tank pipeline joint, 3b is an upper air groove, 3c is a lower air groove, 4 is an upper valve head assembly, 4a is a movable frame, 4b is a sealing gasket, 4c is an outer ring protrusion, 4d is an inner ring protrusion, 4e is an upper spring, 4f is a pressure relief gas path, 4g is a connecting part, 4h is a connecting hole, 4i is a notch, 5 is a lower valve head assembly, 5a is a lower valve head, 5b is a lower spring, 5c is a lower sealing gasket, and 6 is a guide rib. DETAILED DESCRIPTION

[0035] Clearly, the described embodiments are merely a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative effort shall fall within the protection scope of the present application.

[0036] As shown in the drawings, the present application is a split type oil tank isolation valve, comprising Figures 1-5

[0037] A valve shell 1 is internally provided with a tube cavity for air flow, the tube cavity is divided into an upper tube cavity 1a and a lower tube cavity 1b by an inner ring table 1c, the upper tube cavity 1a and the lower tube cavity 1b are communicated through a first air hole 1d in the middle of the inner ring table 1c and four second air holes 1e in the outer periphery of the first air hole 1d, and an oil tank pipeline joint 1f for communicating the upper tube cavity 1a is processed on the outer wall of the valve shell 1;

[0038] An electromagnetic coil assembly 2 is installed on the top of the valve shell 1 and seals the valve shell 1 from the top of the valve shell 1, and comprises a moving iron core 2b movably arranged in the electromagnetic coil 2a, the moving iron core 2b is provided with a T-shaped head at the bottom, and the moving iron core 2b moves up and down in the upper tube cavity 1a under the action of the electromagnetic coil 2a;

[0039] An upper valve head assembly 4 comprises an upper valve head connected to the T-shaped head, and an upper spring 4e is further arranged between the upper valve head and the electromagnetic coil assembly 2, the upper spring 4e provides a pushing force to push the upper valve head close to the inner ring table 1c, the upper valve head comprises an upper sealing gasket 4b connected to the bottom of a movable frame 4a, the movable frame 4a is connected to the T-shaped head, the top of the movable frame 4a is provided with a connecting part 4g, a connecting hole 4h is formed on the connecting part 4g, a notch 4i for inserting the T-shaped head is processed on the side of the connecting part 4g, and a pressure relief air path 4f is formed in the center of the movable frame 4a to communicate with the first air hole 1d, the bottom of the upper sealing gasket 4b is provided with an outer ring protrusion 4c for forming a first sealing surface and an inner ring protrusion 4d for forming a second sealing surface, and the second air hole 1e is located between the first sealing surface and the second sealing surface;

[0040] A lower valve head 5a assembly 5 comprises a lower valve head 5a supported on the bottom cover 3 by a lower spring 5b, the lower valve head 5a adopts a bottle cap structure, the lower spring 5b provides a pushing force to push the lower valve head 5a close to the inner ring table 1c, and the top of the lower valve head 5a is provided with a lower sealing gasket 5c for contacting the bottom surface of the inner ring table 1c to form a third sealing surface, and the third sealing surface is used to close the first air hole 1d;

[0041] ​The bottom cover 3 is installed at the bottom of the valve shell 1, and a carbon tank pipeline joint 3a communicating with the lower pipe cavity 1b is arranged at the center of the bottom of the bottom cover 3; a flow limiting structure is processed on the inner wall of the bottom cover 3, and the flow limiting structure comprises an upper air groove 3b and a lower air groove 3c formed on the inner wall of the bottom cover 3; the radial gap between the upper air groove 3b and the lower valve head 5a is greater than the radial gap between the lower air groove 3c and the lower valve head 5a; the lower valve head 5a forms a flow limiting air path with the upper air groove 3b and the lower air groove 3c; and guide ribs 6 are processed on the inner walls of the bottom cover 3 and the lower pipe cavity 1b.

[0042] As shown in the schematic diagram of the connection between the oil tank and the carbon tank, the working principle of the application comprises the following three working states: Figure 6

[0043] As shown in the working state one, oil filling and exhaust: Figure 7

[0044] During the oil filling process, if the pressure in the oil tank is too high, air needs to be discharged from the oil tank to the carbon tank; at this time, the electromagnetic coil assembly 2 is controlled to work, the moving iron core 2b is driven to move upward, the upper valve head assembly 4 is driven to rise, the outer ring protrusion 4c is separated from the inner ring table 1c, the first sealing surface is opened, and air is supplemented from the carbon tank to the oil tank.

[0045] During the oil filling process, if the pressure in the oil tank is too low, air needs to be supplemented from the carbon tank to the oil tank; at this time, the electromagnetic coil assembly 2 is controlled to work, the moving iron core 2b is driven to move upward, the upper valve head assembly 4 is driven to rise, the outer ring protrusion 4c is separated from the inner ring table 1c, the first sealing surface is opened, and air is supplemented from the carbon tank to the oil tank.

[0046] As shown in the working state two, normal exhaust: Figure 8

[0047] After the oil filling is completed, the electromagnetic coil assembly 2 drives the moving iron core 2b to move downward, so that the inner ring protrusion 4d of the upper sealing gasket 4b and the outer ring protrusion 4c abut against the inner ring table 1c, the first sealing surface and the second sealing surface are closed, and at the same time, the lower valve head 5a abuts against the bottom surface of the inner ring table 1c under the action of the lower spring 5b, and the third sealing surface is closed; when the pressure in the oil tank rises and the pressure plus the weight of the lower valve head 5a exceeds the elastic force of the lower spring 5b, the air pressure pushes the lower valve head 5a downward from the pressure relief air path 4f, the third sealing surface is opened, the oil tank discharges air to the carbon tank, and after the pressure inside and outside the oil tank is balanced, the second sealing surface is re-closed under the action of the lower spring 5b;

[0048] As shown in the working state three, normal air supplement: Figure 9

[0049] ​​​​When the pressure in the oil tank decreases, the pressure in the carbon tank exceeds the elastic force of the upper valve head and the upper spring 4e, the upper valve head is lifted from the second vent hole 1e to open the first sealing surface, the carbon tank supplies air to the oil tank, and after the pressure balance, the first sealing surface is resealed under the action of the upper spring 4e.

[0050] As Figure 10 The schematic diagram of the flow limiting principle of the present application is shown, the thick arrow at the upper air groove 3b represents large flow, and the thin arrow at the lower air groove 3c represents small flow; during exhaust, the lower end surface of the lower valve head 5a is located in the lower air groove 3c region, and the flow is calculated according to the smaller air passage (the gap between the lower air groove 3c and the lower valve head 5a), when the pressure in the oil tank decreases, the lower valve head 5a gradually rises under the action of the lower spring 5b, so that the lower end surface of the lower valve head 5a exceeds the lower air groove 3c to escape from the small flow air passage restriction, and the lower end surface is located in the upper air groove 3b region, completing the conversion of the air passage from the lower air groove 3c to the upper air groove 3b (small flow to large flow), and starting large flow exhaust, because the pressure in the oil tank is slowly reduced at this time, it will not cause the FLVV valve in the oil tank to be blocked again, and the structure designed in this way only needs to be improved by structure and realizes flow limiting, without the need for independent structure, thereby reducing the cost.

[0051] The above examples are only used to help understand the method of the present application and its core idea. It should be noted that for ordinary skilled persons in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A split oil tank isolation valve, characterized by, Comprising The valve shell (1) is internally provided with a tube cavity for air passage, the tube cavity is divided into upper tube cavity (1a) and lower tube cavity (1b) by inner ring table (1c), the upper tube cavity (1a) and the lower tube cavity (1b) are communicated through the first air hole (1d) in the middle of the inner ring table (1c) and the second air hole (1e) in the outer periphery of the first air hole (1d), the valve shell (1) is provided with an oil tank pipeline joint (1f) for communicating the upper tube cavity (1a); The upper valve head assembly (4) is movably arranged in the upper tube cavity (1a), and is close to or away from the inner ring table (1c) to block or open the first and second air holes, when blocking, the upper valve head assembly (4) forms a first sealing surface and a second sealing surface with the inner ring table (1c), and the second air hole (1e) is located between the first and second sealing surfaces, the upper valve head assembly (4) is provided with a pressure relief air passage (4f) for communicating the first air hole (1d); The lower valve head (5a) assembly (5) is movably arranged in the lower tube cavity (1b), and is close to or away from the upper valve head assembly (4) to block or open the first air hole, when blocking, the lower valve head (5a) assembly (5) forms a third sealing surface between the inner ring table (1c); The electromagnetic coil assembly (2) is installed at the top of the valve shell (1) to control the upper valve head assembly (4) to be close to or away from the inner ring table (1c); The bottom cover (3) is installed at the bottom of the valve shell (1), the bottom cover (3) is provided with a carbon tank pipeline joint (3a) for communicating the lower tube cavity (1b), the inner wall of the bottom cover (3) is processed with a flow limiting structure, the flow limiting structure includes an upper air groove (3b) and a lower air groove (3c) opened on the inner wall of the bottom cover (3), the gap between the upper air groove (3b) and the lower valve head (5a) assembly (5) is greater than the gap between the lower air groove (3c) and the lower valve head (5a) assembly (5), and the lower valve head (5a) assembly (5) forms a flow limiting air passage with the upper air groove (3b) and the lower air groove (3c).

2. The split oil tank isolation valve of claim 1, wherein, The inner wall of the bottom cover (3) and the lower tube cavity (1b) is processed with a guide rib (6).

3. The split oil tank isolation valve according to claim 1 or 2, characterized in that The upper valve head assembly (4) includes an upper valve head connected to the electromagnetic coil assembly (2), an upper spring (4e) is further arranged between the upper valve head and the electromagnetic coil assembly (2), the upper spring (4e) provides a pushing force to push the upper valve head to be close to the inner ring table (1c), and the pressure relief air passage (4f) is opened in the upper valve head.

4. The split oil tank isolation valve of claim 3, wherein, The upper valve head includes an upper sealing gasket (4b) connected to the bottom of the movable frame (4a), the bottom of the upper sealing gasket (4b) is provided with an outer ring protrusion (4c) for forming a first sealing surface and an inner ring protrusion (4d) for forming a second sealing surface.

5. The split oil tank isolation valve of claim 4, wherein, The top of the movable frame (4a) is provided with a connecting part (4g), a connecting hole (4h) is opened in the connecting part (4g), the electromagnetic coil assembly (2) includes a movable iron core (2b) movably arranged in the electromagnetic coil (2a), the bottom of the movable iron core (2b) is provided with a T-shaped head, and the side of the connecting part (4g) is processed with a notch (4i) for inserting the T-shaped head.

6. The split oil tank isolation valve of claim 1 or 2, wherein, The lower valve head (5a) assembly (5) comprises a lower valve head (5a) supported on the bottom cover (3) by a lower spring (5b), the lower spring (5b) provides a pushing force to push the lower valve head (5a) close to the inner ring platform (1c), the top of the lower valve head (5a) is provided with a lower sealing gasket (5c) used to contact the bottom surface of the inner ring platform (1c) to form a third sealing surface, and the third sealing surface is used to close the first air hole (1d).

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