Oil tank isolation leakage diagnosis module

Abstract

The utility model discloses an oil tank isolation leakage diagnosis module, which belongs to the technical field of oil tank isolation leakage diagnosis and comprises a shell provided with an oil tank connector, a carbon tank inlet, a carbon tank outlet, an atmosphere connector, a mounting port and an electric appliance connector. The electromagnetic valve is arranged in the shell so as to control the opening and closing of the carbon tank outlet and the atmosphere interface; the oil tank isolation valve is mounted in the shell so as to control the opening and closing of the oil tank interface and the carbon tank inlet; the air pump is installed at the center position in the shell, the top of the air pump corresponds to the position of the electric appliance connector, and the air pump is communicated with or sealed with an external oil tank through the oil tank isolation valve; the one-way valve is installed in the shell and located at the bottom of the air pump. According to the utility model, oil tank isolation processing and leakage diagnosis processing can be simultaneously realized, the structure integration degree is high, and the arrangement space of the whole vehicle can be effectively saved.

Description

Technical Field

[0001] This utility model belongs to the field of fuel tank isolation leakage diagnosis technology, and in particular relates to a fuel tank isolation leakage diagnosis module. Background Technology

[0002] According to the China VI emission standard (GB18352.6) for light-duty vehicles, OBD leak diagnosis of the vehicle's fuel evaporation system is required. An alarm will illuminate if the leak exceeds the regulatory limit. Therefore, a leak test must be performed during vehicle startup to ensure that fuel vapor does not leak into the atmosphere.

[0003] To meet the diagnostic needs of fuel evaporation systems in various internal combustion engine vehicles (such as pure gasoline vehicles, plug-in hybrid electric vehicles, and range-extended hybrid electric vehicles), the current mainstream technical approach is the active diagnostic approach. This approach uses an air pump to create a vacuum or pressurize the system, uses solenoid valves to seal the system or switch channels, and determines whether there are any leaks in the system by comparing pressure parameters with built-in standard orifices or monitoring pressure decay parameters under sealed conditions.

[0004] Meanwhile, to adapt to the development trend of new energy vehicles, the market share of hybrid vehicles currently exceeds that of pure gasoline vehicles. Due to the characteristic of hybrid vehicles that the engine does not operate under all conditions, a fuel tank isolation valve is typically installed between the fuel tank and the carbon canister to ensure that fuel vapor in the fuel tank does not overload the carbon canister. This seals the fuel vapor within the fuel tank, allowing communication between the fuel tank and the carbon canister only when necessary.

[0005] In the invention patent with publication number CN118769877A, a typical configuration of a fuel evaporation system for a hybrid electric vehicle is disclosed: 01-high-pressure fuel tank; 02-carbon canister; 03-carbon canister control valve; 04-engine intake manifold; 05-leak diagnosis module DMTL; 37-fuel tank isolation valve; 39-fuel tank pressure sensor; where 37-fuel tank isolation valve is used to seal the high-pressure fuel tank, and 05-leak diagnosis module DMTL is used for leak diagnosis of the fuel evaporation system. These are two separate components, typically connected to the carbon canister via hoses. Because the fuel tank isolation valve and leak diagnosis module are two separate components, they require separate installation points, necessitating more space in the vehicle layout and requiring two sets of wiring harnesses for connection and control, thus increasing procurement costs. Utility Model Content

[0006] This invention overcomes the shortcomings of the prior art by providing a fuel tank isolation leak diagnosis module to solve the problems existing in the prior art.

[0007] To achieve the above object, the utility model discloses technical scheme for: a kind of oil tank isolation leakage diagnosis module, including

[0008] Shell, oil tank interface, carbon can inlet, carbon can outlet, atmosphere interface, mounting hole and electrical connection port are equipped on the shell;

[0009] Solenoid valve, the solenoid valve is installed in the shell, to control the carbon can outlet and the atmosphere interface opening and closing;

[0010] Oil tank isolation valve, the oil tank isolation valve is installed in the shell, to control the oil tank interface and the carbon can inlet opening and closing;

[0011] Air pump, the air pump is installed at the central position in the shell, and the air pump top portion corresponds with the electrical connection port position, and the air pump is communicated or closed with external oil tank by the oil tank isolation valve;

[0012] Check valve, the check valve is installed in the shell, and is located at the air pump bottom portion.

[0013] In a preferred embodiment of the utility model, the shell is provided with a first cavity, a second cavity and a third cavity to install the solenoid valve, the oil tank isolation valve and the air pump respectively.

[0014] In a preferred embodiment of the utility model, the solenoid valve is installed in the first cavity, and the solenoid valve includes a first valve body, a first moving iron core, a first static iron core, a sealing rod and a first valve seat, and the first moving iron core, the first static iron core, the sealing rod and the first valve seat are all installed in the first valve body.

[0015] In a preferred embodiment of the utility model, a first electromagnetic coil is arranged on the outer ring of the first moving iron core, the first static iron core is fixedly installed in the first valve body, the sealing rod is installed on the first moving iron core, and a first spring is arranged on the first valve seat, and when the first electromagnetic coil is energized, the first moving iron core presses down the first spring through the sealing rod to seal the bottom of the first valve body by the first valve seat.

[0016] In a preferred embodiment of the utility model, the oil tank isolation valve is installed in the second cavity, and the oil tank isolation valve includes a winding drum, an upper static valve core, a lower static valve core, a moving valve core, a sealing member, a second valve seat and a pressure relief block, and the upper static valve core, the lower static valve core and the moving valve core are all located in the winding drum.

[0017] The utility model discloses a preferable embodiment of the utility model, the outer circle of the bobbin is provided with second electromagnetic coil, the upper static valve core, lower static valve core and dynamic valve core are in the bobbin from top to bottom distribution in proper order, the sealing element includes upper sealing element and lower sealing element, the upper sealing element is connected with the dynamic valve core through upper return spring, and the lower sealing element end is provided with lower return spring.

[0018] The utility model discloses a preferable embodiment of the utility model, be provided with guide stick and guide plate in the bobbin to the dynamic valve core orientation.

[0019] The utility model discloses a preferable embodiment of the utility model, the air pump bottom is equipped with the air outlet, and the side is equipped with the air inlet, and the air inlet with electromagnetic valve position corresponds.

[0020] The utility model discloses a preferable embodiment of the utility model, the one-way valve is umbrella-shaped diaphragm valve, and the one-way valve sets up at the air outlet position of air pump.

[0021] The utility model solves the defect in the background art, and the utility model has the following beneficial effects:

[0022] The oil tank isolation leakage diagnosis module can realize oil tank isolation treatment and leakage diagnosis treatment simultaneously, has high structure integration degree, can effectively save vehicle layout space, can effectively reduce preparation cost, and only needs once installation, only needs a set of wire harness to connect control, and operation is more convenient. BRIEF DESCRIPTION OF DRAWINGS

[0023] The utility model will be further explained in connection with the drawings and examples;

[0024] Figure 1 It is the whole structure schematic view of preferred embodiment of the utility model;

[0025] Figure 2 It is the whole sectional view of preferred embodiment of the utility model;

[0026] Figure 3 It is the structure sectional view of electromagnetic valve of preferred embodiment of the utility model;

[0027] Figure 4 It is the structure sectional view of oil tank isolation valve of preferred embodiment of the utility model;

[0028] In the figure: 10, the shell; 11, the oil tank interface; 12, the carbon tank inlet; 13, the carbon tank outlet; 14, the atmosphere interface; 15, the mounting port; 16, the electrical connection port; 20, the electromagnetic valve; 21, the first valve body; 22, the first moving iron core; 23, the first static iron core; 24, the sealing rod; 25, the first valve seat; 30, the oil tank isolation valve; 31, the bobbin; 311, the guide rod; 312, the guide plate; 32, the upper static valve core; 33, the lower static valve core; 34, the moving valve core; 35, the sealing element; 351, the upper sealing element; 352, the lower sealing element; 36, the second valve seat; 37, the pressure relief block; 40, the air pump; 41, the air outlet; 42, the air inlet; 50, the one-way valve; 60, the first electromagnetic coil; 70, the first spring; 80, the second electromagnetic coil; 90, the upper return spring; 100, the lower return spring. DETAILED DESCRIPTION

[0029] The utility model will be further explained below in combination with the drawings and specific embodiments, so that the person skilled in the art can better understand the utility model and can be implemented, but the embodiment is not as the limitation of the utility model.

[0030] The oil tank isolation leakage diagnosis module provided by the embodiment can simultaneously realize oil tank isolation treatment and leakage diagnosis treatment, has high structural integration degree, can effectively save vehicle layout space, can effectively reduce preparation cost, and only needs to be installed once, only needs to be connected and controlled by one set of wire harness, and operation is more convenient.

[0031] In combination with Figure 1 With Figure 2 As shown in the figure, the oil tank isolation leakage diagnosis module of the embodiment comprises a shell 10, an electromagnetic valve 20, an oil tank isolation valve 30, an air pump 40 and a one-way valve 50, the shell 10 is provided with a first cavity, a second cavity and a third cavity to install the electromagnetic valve 20, the oil tank isolation valve 30 and the air pump 40 respectively, the one-way valve 50 is installed in the shell 10 and located at the bottom of the air pump 40, and the electromagnetic valve 20 of the embodiment is a normally open valve, and the oil tank isolation valve 30 is a normally closed valve.

[0032] In the embodiment, the shell 10 is provided with an oil tank interface 11, a carbon tank inlet 12, a carbon tank outlet 13, an atmosphere interface 14, a mounting port 15 and an electrical connection port 16, the oil tank interface 11 is connected to the automobile oil tank, the carbon tank inlet 12 is connected to the carbon tank, the atmosphere interface 14 is connected to the outside atmosphere through an air cleaner, the mounting port 15 can integrally externally mount the module, and the electrical connection port 16 is connected to the vehicle controller module through a wire harness to realize power supply and control.

[0033] In combination with Figure 2 With Figure 3As shown, the electromagnetic valve 20 of the embodiment is installed in the shell 10 to control the opening and closing of the carbon canister outlet 13 and the atmosphere interface 14. The electromagnetic valve 20 is installed in the first cavity. The electromagnetic valve 20 includes a first valve body 21, a first moving iron core 22, a first static iron core 23, a sealing rod 24, and a first valve seat 25. The first moving iron core 22, the first static iron core 23, the sealing rod 24, and the first valve seat 25 are all installed in the first valve body 21.

[0034] In the embodiment, the first moving iron core 22 is provided with a first electromagnetic coil 60. The first static iron core 23 is fixedly installed in the first valve body 21. The sealing rod 24 is installed on the first moving iron core 22. The first valve seat 25 is provided with a first spring 70. When the first electromagnetic coil 60 is energized, the first moving iron core 22 presses the first spring 70 downward through the sealing rod 24 to seal the bottom of the first valve body 21 by the first valve seat 25. The electromagnetic valve 20 of the embodiment is a normally open valve. When the first electromagnetic coil 60 is not energized, the spring force of the first spring 70 overcomes the gravity of the first moving iron core 22 and the sealing rod 24, so that the sealing rod 24 is away from the first valve seat 25, and the electromagnetic valve 20 is in an open state. When the first electromagnetic coil 60 is energized, an electromagnetic force is generated, so that the first moving iron core 22 and the first static iron core 23 are magnetized to generate an attractive force under the action of the magnetic field. The first moving iron core 22 moves downward to push the sealing rod to compress the first spring 70 until the first valve seat 25 is completely adhered to form a sealing effect.

[0035] In combination Figure 2 With Figure 4 As shown, the oil tank isolation valve 30 of the embodiment is installed in the shell 10 to control the opening and closing of the oil tank interface 11 and the carbon canister inlet 12. The oil tank isolation valve 30 is installed in the second cavity. The oil tank isolation valve 30 includes a bobbin 31, an upper static valve core 32, a lower static valve core 33, a moving valve core 34, a sealing element 35, a second valve seat 36, and a pressure relief block 37. The upper static valve core 32, the lower static valve core 33, and the moving valve core 34 are all located in the bobbin.

[0036] In the embodiment, the second electromagnetic coil 80 is arranged on the outer ring of the bobbin 31, the upper static valve core 32, the lower static valve core 33 and the dynamic valve core 34 are sequentially arranged from top to bottom in the bobbin 31, the sealing member 35 comprises an upper sealing member 351 and a lower sealing member 352, the upper sealing member 351 is connected with the dynamic valve core 34 through the upper return spring 90, the lower end of the lower sealing member 352 is provided with the lower return spring 100, under the condition that the second electromagnetic coil 80 is not powered, the upper return spring 90 is in a compressed state, the spring force of the upper return spring 90 acts on the dynamic valve core 34 and the upper sealing member 351, so that the upper sealing member 351 is tightly attached to the upper surface of the passage of the second valve seat 36, at the same time, the lower return spring 100 is also in a compressed state, the spring force of the lower return spring 100 acts on the pressure relief block 37, so that the pressure relief block 37 is tightly attached to the lower surface of the passage of the second valve seat 36. Therefore, the passage of the second valve seat 36 is closed, and the oil tank isolation valve 30 is in a closed state.

[0037] Further, the bobbin of the embodiment is provided with a guide rod and a guide plate to guide the dynamic valve core.

[0038] In combination with Figure 1 With Figure 2 As shown in the figure, the air pump 40 of the embodiment is installed at the center position in the shell 10, the top of the air pump 40 corresponds to the position of the electrical appliance connecting port 16, the air pump 40 is communicated or closed with the external oil tank through the oil tank isolation valve 30, the bottom of the air pump 40 is provided with an air outlet 41, and the side is provided with an air inlet 42, the air inlet 42 corresponds to the position of the electromagnetic valve 20, the one-way valve 50 is an umbrella-shaped diaphragm valve, the one-way valve 50 is arranged at the position of the air outlet 41 of the air pump 40, and the gas is guided into the air pump 40 through the one-way valve 50, so as to carry out the leakage diagnosis.

[0039] In actual use, the oil tank isolation leakage diagnosis module is fixed on the body of the chassis through the mounting port 15, the oil tank port 11 is connected with the high-pressure oil tank through the pipeline, the carbon can inlet 12 is connected with the Tank end of the carbon can through the pipeline, the carbon can outlet 13 is connected with the Purge end of the carbon can through the pipeline, the atmosphere port 14 is connected with the air filter and the outside atmosphere, and the electrical appliance connecting port 16 is connected with the vehicle controller module through the wire harness, so as to realize the power supply and control.

[0040] In combination with Figures 1 to 4 As shown in the figure, the oil tank isolation leakage diagnosis module of the embodiment integrates the isolation oil tank function, under the condition that no power is supplied, the oil tank isolation valve 30 is in a closed state, at this time, the connection between the oil tank and the carbon can is closed, the oil tank is in a closed state, and the fuel vapor is closed in the high-pressure oil tank.

[0041] When the vehicle needs to be refueled or to be detached, the oil tank needs to be communicated with the atmosphere through the carbon canister, at this time, the second electromagnetic coil 80 is energized by the vehicle controller, and the oil tank isolation valve 30 is in the open state.

[0042] When the vehicle is stationary for a long time or in the pure electric driving mode, the fuel in the oil tank continuously evaporates to produce fuel vapor, causing the internal pressure of the oil tank to continuously rise. When the internal pressure of the oil tank reaches the threshold of the safety pressure (35kpa in this embodiment), the pressure in the oil tank is applied to the surface of the pressure relief block 37 through the bypass of the second valve seat 36 through the oil tank interface 11, so that the pressure relief block 37 overcomes the spring force of the lower return spring 100 and is compressed. The pressure relief block 37 is separated from the lower surface of the second valve seat 36, and at this time the oil tank isolation valve 30 is passively opened to release the pressure of the oil tank. At this time, the oil tank and the carbon canister are communicated, and then communicated with the atmosphere through the electromagnetic valve 20.

[0043] In combination Figures 1 to 4 As shown in the figure, the oil tank isolation leakage diagnosis module of the embodiment integrates the leakage diagnosis function. When the vehicle meets the preconditions for leakage diagnosis (for example: driving cycle, water temperature, oil level, voltage and carbon canister load) and needs to perform fuel evaporation system leakage diagnosis. First, the second electromagnetic coil 80 is energized by the vehicle controller, so that the oil tank isolation valve 30 is actively opened, and then the first electromagnetic coil 60 is energized, so that the electromagnetic valve 20 is closed, and then the air pump 40 is powered on and runs, and the one-way valve 50 is opened. The air pump 40 is inflated. In this process, the oil tank pressure sensor (not shown in the figure) monitors the pressure in the oil tank, and when the oil tank pressure reaches the threshold P1 (5kpa in this embodiment) within the set time T1 (60s in this embodiment), it means that the fuel evaporation system has no large leakage, and can enter the next pressure maintaining monitoring stage.

[0044] At this time, the oil tank isolation valve 30 and the electromagnetic valve 20 are both energized, the air pump 40 is powered off, the P1 pressure in the oil tank passes through the oil tank isolation valve 30 and the carbon canister, and acts on the one-way valve 50, so that the one-way valve 50 is closed. At the same time, the electromagnetic valve 20 is also in the energized closed state. Therefore, the system formed by the entire carbon canister plus the oil tank plus the oil tank isolation valve 30 is closed. The oil tank pressure sensor monitors the pressure decay curve in the oil tank for T2 time (30s in this embodiment), and reads P2. Thus, it is judged whether the fuel evaporation system has a 1.0mm leakage.

[0045] Obviously, the above embodiment is only an example for clear illustration, not a limitation of the implementation. For ordinary skilled persons in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to enumerate all the implementations. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A fuel tank isolation leak diagnosis module, characterized in that, include The housing (10) is provided with an oil tank interface (11), a carbon canister inlet (12), a carbon canister outlet (13), an atmospheric interface (14), an installation port (15), and an electrical connection port (16); Solenoid valve (20), which is installed inside the housing (10), controls the opening and closing of the carbon canister outlet (13) and the atmospheric interface (14); A tank isolation valve (30) is installed inside the housing (10) to control the opening and closing of the tank interface (11) and the carbon canister inlet (12); An air pump (40) is installed in the center of the housing (10). The top of the air pump (40) corresponds to the position of the electrical connection port (16). The air pump (40) is connected to or closed to the external oil tank through the oil tank isolation valve (30). A one-way valve (50) is installed inside the housing (10) and located at the bottom of the air pump (40).

2. The fuel tank isolation leak diagnosis module according to claim 1, characterized in that, The housing (10) is provided with a first cavity, a second cavity and a third cavity, for mounting the solenoid valve (20), the oil tank isolation valve (30) and the air pump (40) respectively.

3. The fuel tank isolation leak diagnosis module according to claim 2, characterized in that, The solenoid valve (20) is installed in the first cavity. The solenoid valve (20) includes a first valve body (21), a first moving iron core (22), a first stationary iron core (23), a sealing rod (24), and a first valve seat (25). The first moving iron core (22), the first stationary iron core (23), the sealing rod (24), and the first valve seat (25) are all installed in the first valve body (21).

4. The fuel tank isolation leak diagnosis module according to claim 3, characterized in that, The first moving iron core (22) is provided with a first electromagnetic coil (60) on its outer ring. The first stationary iron core (23) is fixedly installed inside the first valve body (21). The sealing rod (24) is installed on the first moving iron core (22). The first valve seat (25) is provided with a first spring (70). When the first electromagnetic coil (60) is energized, the first moving iron core (22) presses down the first spring (70) through the sealing rod (24) so ​​that the first valve seat (25) seals the bottom of the first valve body (21).

5. The fuel tank isolation leak diagnosis module according to claim 2, characterized in that, The oil tank isolation valve (30) is installed in the second cavity. The oil tank isolation valve (30) includes a winding drum (31), an upper static valve core (32), a lower static valve core (33), a moving valve core (34), a seal (35), a second valve seat (36), and a pressure relief block (37). The upper static valve core (32), the lower static valve core (33), and the moving valve core (34) are all located inside the winding drum (31).

6. The fuel tank isolation leak diagnosis module according to claim 5, characterized in that, The outer ring of the winding drum (31) is provided with a second electromagnetic coil (80). The upper stationary valve core (32), the lower stationary valve core (33) and the moving valve core (34) are distributed in the winding drum (31) from top to bottom. The sealing element (35) includes an upper sealing element (351) and a lower sealing element (352). The upper sealing element (351) is connected to the moving valve core (34) through an upper return spring (90). The lower sealing element (352) is provided with a lower return spring (100) at its end.

7. A fuel tank isolation leak diagnosis module according to claim 6, characterized in that, The winding drum (31) is provided with a guide rod (311) and a guide plate (312) to guide the moving valve core (34).

8. The fuel tank isolation leak diagnosis module according to claim 1, characterized in that, The air pump (40) has an air outlet (41) at the bottom and an air inlet (42) on the side, and the air inlet (42) corresponds to the position of the solenoid valve (20).

9. A fuel tank isolation leak diagnosis module according to claim 8, characterized in that, The one-way valve (50) is an umbrella-shaped diaphragm valve, and the one-way valve (50) is located at the air outlet (41) of the air pump (40).

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