Carbon tank emission control device

Abstract

The carbon tank emission control device provided by the invention comprises an oil tank, a carbon tank and a control unit, the oil tank comprises an oil storage cavity which is internally provided with an oil pump assembly. The carbon tank is connected with the engine through an air inlet pipe and communicated with the oil storage cavity through an oil-gas pipeline, and an isolating valve for controlling opening and closing of the oil-gas pipeline is installed on the oil-gas pipeline. The carbon tank is communicated with the outside through an atmosphere pipeline; a closed valve for controlling the atmosphere pipeline to open and close is mounted on the atmosphere pipeline; the control unit is in communication connection with the isolating valve and the closed valve; after the control unit receives a refueling mode signal of the vehicle, the isolation valve and the closed valve are controlled to be opened; after the control unit receives a normal mode signal of the vehicle, the isolation valve and the closed valve are controlled to be closed; after receiving a desorption mode signal of the vehicle, the control unit controls the isolating valve to be closed and controls the closed valve to be opened, and the engine sucks the carbon tank through the air inlet pipe. According to the invention, almost zero emission of the vehicle in a long-time parking state and a normal driving state is realized.

Description

Technical Field

[0001] This invention belongs to the field of fuel evaporation emission control technology and relates to a carbon canister emission control device. Background Technology

[0002] With increasingly stringent environmental regulations, controlling vehicle fuel evaporation emissions has become increasingly important. The carbon canister is a key component in the evaporative emission control system (EVAP) for adsorbing and storing fuel vapors that evaporate from the fuel tank.

[0003] Existing gasoline engine vehicles mainly meet emission requirements through carbon canister desorption and cleaning. However, in new energy hybrid vehicles, the engine start time is significantly reduced in the master driving mode, and the effectiveness of carbon canister desorption and cleaning needs to be improved in order to achieve near-zero emissions when the vehicle is parked for a long time or under normal driving conditions. Summary of the Invention

[0004] This application provides a carbon canister emission control device to solve the problems existing in the prior art and achieve near-zero emissions for vehicles in both long-term parking and normal driving conditions.

[0005] The carbon canister emission control device provided in this application includes: a fuel tank, a carbon canister, and a control unit; the fuel tank includes a fuel storage chamber, in which a fuel pump assembly is installed; the carbon canister is connected to the engine via an intake pipe, and the carbon canister is connected to the fuel storage chamber via an oil-gas pipeline, on which an isolation valve for controlling the opening and closing of the oil-gas pipeline is installed; the carbon canister is connected to the outside via an atmospheric pipeline, on which a sealing valve for controlling the opening and closing of the atmospheric pipeline is installed; the control unit is communicatively connected to both the isolation valve and the sealing valve; when the vehicle is in refueling mode, the control unit, upon receiving a refueling mode signal from the vehicle, controls both the isolation valve and the sealing valve to open; when the vehicle is in normal mode, the control unit, upon receiving a normal mode signal from the vehicle, controls both the isolation valve and the sealing valve to close; when the vehicle is in desorption mode, the control unit, upon receiving a desorption mode signal from the vehicle, controls the isolation valve to close and the sealing valve to open, and the engine draws air from the carbon canister through the intake pipe.

[0006] Optionally, the oil pump assembly is equipped with a liquid level sensor for detecting the oil level in the oil storage chamber; the control unit is communicatively connected to the liquid level sensor and receives the liquid level signal transmitted by the liquid level sensor; in the refueling mode, when the liquid level signal received by the control unit is higher than a preset height value, the control unit controls the sealing valve to close.

[0007] Optionally, the liquid level sensor includes a float that floats on the oil and a sliding rheostat that is linked to the float, the sliding rheostat being communicatively connected to the control unit.

[0008] Optionally, in the refueling mode, when the liquid level signal received by the control unit is higher than a preset percentage of the preset height value, and the rate of change of the liquid level signal exceeds a preset rate of change, the control unit controls the sealing valve to close.

[0009] Optionally, the carbon canister is equipped with a pressure sensor that is communicatively connected to the control unit. After receiving a refueling mode signal, the control unit first controls the sealing valve to open; after receiving the pressure value transmitted by the pressure sensor and reaching a preset pressure value, or after a first preset time, it controls the isolation valve to open.

[0010] Optionally, the isolation valve and the sealing valve are integrated into a two-position three-way solenoid valve. The two-position three-way solenoid valve has a common port connected to the carbon canister, a normally closed port connected to the oil and gas pipeline, and a normally open port connected to the atmospheric pipeline. The control unit is communicatively connected to the two-position three-way solenoid valve to control the opening and closing switching of the isolation valve and the sealing valve in the refueling mode, the normal mode, and the desorption mode.

[0011] Optionally, the carbon canister emission control device further includes a central control unit; when the central control unit detects that the vehicle is in the refueling mode, it transmits the refueling mode signal to the control unit; when the central control unit detects that the vehicle is in the normal mode, it transmits the normal mode signal to the control unit; when the central control unit detects that the vehicle is in the desorption mode, it transmits the desorption mode signal to the control unit.

[0012] Optionally, after the central control unit detects that the fuel tank cap is open and the engine is stopped, it determines the vehicle's refueling mode and transmits the refueling mode signal to the control unit.

[0013] Optionally, after the central control unit detects that the engine has started and the vehicle speed has been continuously higher than a preset speed for more than a second preset time, it determines that the vehicle is in disengagement mode and transmits the disengagement mode signal to the control unit.

[0014] Optionally, after the central control unit detects that the vehicle is not in the refueling mode or the desorption mode, it determines that the vehicle is in the normal mode and transmits the normal mode signal to the control unit.

[0015] The above technical solution has the following beneficial effects: The carbon canister emission control device provided in this application uses a control unit to control the opening and closing of an isolation valve to control the connection and isolation between the fuel reservoir and the carbon canister; and controls the opening and closing of a sealing valve to control the connection and isolation between the carbon canister and the external environment. In refueling mode, both the isolation valve and the sealing valve are open, allowing the fuel vapors generated during refueling that enter the fuel reservoir to be discharged through them. In normal mode, both the isolation valve and the sealing valve are closed, confining the fuel vapors in the carbon canister and achieving zero emissions. In desorption mode, the isolation valve cuts off the connection between the fuel tank and the carbon canister, and the engine draws fuel vapors from the carbon canister through the intake manifold, creating a vacuum environment inside the carbon canister. External air enters the carbon canister through the sealing valve, similarly preventing the escape of fuel vapors. Thus, in normal mode and desorption mode (from vehicle parking to driving), fuel vapors are effectively controlled, achieving near-zero emissions. Attached Figure Description

[0016] The preferred embodiments of this application will now be described in detail with reference to the accompanying drawings to help understand the purpose and advantages of this application, wherein...

[0017] Figure 1 A schematic diagram of the structure of the carbon canister emission control device provided in an optional embodiment of this application.

[0018] Figure 2 A control principle diagram of a carbon canister emission control device provided in an optional embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: Fuel tank-1, fuel reservoir-10, fuel pump assembly-11, carbon canister-2, intake pipe-20, fuel-air pipeline-21, atmospheric pipeline-22, isolation valve-3, shut-off valve-4, two-position three-way solenoid valve-5, refueling pipe-6, engine control module-7, fuel pump control module-8. Detailed Implementation

[0020] The technical solution of the present invention will be further described in detail below with reference to embodiments and accompanying drawings. The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the structures shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0021] The carbon canister emission control device provided in this application includes an oil tank 1, a carbon canister 2, and a control unit.

[0022] The oil tank 1 includes an oil storage chamber 10, within which an oil pump assembly 11 is housed. The oil tank 1 may be made of high-density polyethylene to provide oil storage space. The oil pump assembly 11 is fixed to the top or bottom of the oil storage chamber 10 by a flange and a sealing ring.

[0023] The carbon canister 2 contains activated carbon and is connected to the engine via the intake pipe 20. The carbon canister 2 is also connected to the oil reservoir 10 via an oil-gas pipeline 21, on which an isolation valve 3 is installed to control its opening and closing. The carbon canister 2 is also connected to the outside environment via an atmospheric pipeline 22, on which a sealing valve 4 is installed to control its opening and closing.

[0024] Both isolation valve 3 and sealing valve 4 are solenoid valves. The control unit is a vehicle body control module or a dedicated control module, containing a microprocessor and drive circuitry, and is communicatively connected to both isolation valve 3 and sealing valve 4 via the vehicle wiring harness. When the vehicle is in refueling mode, the control unit, upon receiving the refueling mode signal, controls both isolation valve 3 and sealing valve 4 to open. When the vehicle is in normal mode, the control unit, upon receiving the normal mode signal, controls both isolation valve 3 and sealing valve 4 to close. When the vehicle is in desorption mode, upon receiving the desorption mode signal, the control unit controls isolation valve 3 to close and sealing valve 4 to open, allowing the engine to draw air from the carbon canister 2 through the intake manifold 20.

[0025] The carbon canister emission control device provided in this application controls the opening and closing of the isolation valve 3 to control the connection and isolation between the oil reservoir 10 and the carbon canister 2; and controls the opening and closing of the sealing valve 4 to control the connection and isolation between the carbon canister 2 and the external environment. In refueling mode, both the isolation valve 3 and the sealing valve 4 are open, and the oil vapor generated during refueling that enters the oil reservoir 10 can be discharged through the isolation valve 3 and the sealing valve 4. In normal mode, both the isolation valve 3 and the sealing valve 4 are closed, and the oil vapor in the carbon canister 2 is confined within the carbon canister 2, achieving zero emissions of oil vapor. In desorption mode, the isolation valve 3 cuts off the connection between the fuel tank 1 and the carbon canister 2, and the engine draws the oil vapor from the carbon canister 2 through the intake pipe 20, creating a vacuum environment inside the carbon canister 2. The outside atmosphere enters the carbon canister 2 through the sealing valve 4, which also prevents the escape of oil vapor. Thus, in normal mode and desorption mode (from the time the vehicle is parked to the time it is driven), oil vapor is effectively controlled, resulting in near-zero emissions.

[0026] In an optional embodiment, the oil pump assembly 11 is equipped with a level sensor for detecting the oil level in the oil storage chamber 10; the control unit is communicatively connected to the level sensor and receives the level signal transmitted by the level sensor; in the refueling mode, when the level signal received by the control unit is higher than a preset height value, the control unit controls the shut-off valve 4 to close. This embodiment of the application can realize automatic overflow protection during the refueling process. Specifically, the refueling nozzle adds oil to the oil storage chamber 10 through the refueling pipe 6. When the oil level reaches a preset height value, for example, 80% of the total height inside the oil storage chamber 10, the shut-off valve 4 is closed, causing the pressure in the fuel tank 1 and carbon canister 2 to increase. This pressure is transmitted in reverse through the oil-gas pipeline 21 to the sensing port of the refueling nozzle, thereby triggering the automatic shut-off mechanism of the refueling nozzle to prevent overfilling and overflow, thus improving safety.

[0027] Furthermore, this embodiment incorporates the liquid level signal into the control of the nozzle shut-off during refueling. The action is performed through the existing sealed valve 4 in the vehicle, which is controlled by the control unit. This not only simplifies the internal structure of the fuel tank 1 and reduces parts costs and failure rates, but also facilitates precise control of the refueling nozzle shut-off in the vehicle.

[0028] Optionally, the level sensor is integrated on the oil pump assembly 11 bracket, and the electrical signal output terminal of the level sensor is connected to the vehicle wiring harness through the oil pump assembly 11 wiring harness interface, and finally connected to the control unit.

[0029] In one optional embodiment, the liquid level sensor includes a float floating in the oil and a sliding rheostat linked to the float, the sliding rheostat being communicatively connected to the control unit. In this embodiment, the resistance signal output by the sliding rheostat linearly reflects the oil level height, and by transmitting the liquid level height signal to the controller in real time, it assists the control unit in accurate judgment.

[0030] Optionally, the float is linked to the slider of the sliding rheostat via a hinged arm. The resistive element of the sliding rheostat is mounted on the bracket of the oil pump assembly 11. The terminals of the sliding rheostat are connected to the wiring harness interface of the oil pump assembly 11 via wires, saving the need for a dedicated mechanical refueling overflow valve that is complex in structure, takes up space, and may fail in traditional systems.

[0031] In an optional implementation, in the refueling mode, when the liquid level signal received by the control unit is higher than a preset percentage of a preset height value, and the rate of change of the liquid level signal exceeds a preset rate of change, the control unit controls the sealing valve 4 to close. The preset percentage can be any value between 80% and 90%. This application embodiment effectively solves the "false full" problem caused by rapid refueling or fuel foaming due to high temperatures through predictive control logic. By monitoring the rate of liquid level rise, it intelligently predicts the risk of oil spills and takes action in advance, improving refueling efficiency while ensuring safety.

[0032] Optionally, the control unit periodically samples the liquid level signal and calculates its rate of change, comparing it with a preset rate of change. The preset rate of change can be 1.5 to 3 times the normal refueling liquid level change rate. For example, if the normal refueling liquid level change rate is 2-3 mm / s, then the preset rate of change can be set to around 5-8 mm / s.

[0033] In an optional embodiment, a pressure sensor communicatively connected to the control unit is installed inside the carbon canister 2. Upon receiving a refueling mode signal, the control unit first controls the opening of the sealing valve 4; after receiving a pressure value transmitted by the pressure sensor that reaches a preset pressure value, or after a first preset time, it then controls the opening of the isolation valve 3. This embodiment, by controlling the timing of venting the carbon canister 2 before connecting it to the fuel tank 1, avoids the instantaneous impact of high-pressure fuel vapor accumulated in the fuel tank 1 on the carbon canister 2 during the initial refueling process, preventing overload saturation of the carbon canister 2 and the intrusion of liquid fuel, thus improving system durability.

[0034] Optionally, the pressure sensor is mounted on the housing of the carbon canister 2, with the probe located inside the carbon canister 2. The pressure sensor is connected to the control unit via its electrical connector and wiring harness. The first preset time can be any value between 10s and 30s.

[0035] In an optional embodiment, the isolation valve 3 and the shut-off valve 4 are integrated into a two-position three-way solenoid valve 5. The two-position three-way solenoid valve 5 has a common port connected to the carbon canister 2, a normally closed port connected to the oil / gas pipeline 21, and a normally open port connected to the atmospheric pipeline 22. The control unit is communicatively connected to the two-position three-way solenoid valve 5 to control the opening and closing switching of the isolation valve 3 and the shut-off valve 4 in the refueling mode, the normal mode, and the desorption mode. This embodiment of the application, through highly integrated design, uses one valve to achieve the functions of two valves, reducing the number of components, weight, and potential leakage points, lowering manufacturing costs and installation complexity, and improving system compactness and reliability.

[0036] Optionally, the body of the dual-position three-way solenoid valve 5 is fixed to the vehicle body by a bracket and located near the carbon canister 2. Its three ports are connected to the carbon canister 2, the fuel / gas line 21, and the atmospheric line 22 respectively via quick-connect fittings. The control unit controls the energization and de-energization of the dual-position three-way solenoid valve 5 via a control line to achieve two-position switching. Further, the dual-position three-way solenoid valve 5 can be a duty cycle control valve (DCV valve), precisely controlled by the engine control module 7 (ECM) via high-frequency pulse signals.

[0037] In alternative implementations, such as Figure 2 As shown, the engine control module 7 can also send an electrical signal to the fuel pump control module 8 (FPCM), and the fuel pump control module 8 controls the two-position three-way solenoid valve 5.

[0038] Furthermore, when the dual-position three-way solenoid valve 5 loses power or communication signal, it automatically resets to a safe state in normal operation due to the force of its internal spring. Simultaneously, when the control unit detects a fault in the drive circuit of the dual-position three-way solenoid valve 5, it sends an alarm to the instrument panel via the CAN bus to enhance safety.

[0039] In an optional implementation, the carbon canister emission control device further includes a central control unit; the central control unit detects that the vehicle is in the refueling mode and transmits the refueling mode signal to the control unit; the central control unit detects that the vehicle is in the normal mode and transmits the normal mode signal to the control unit; the central control unit detects that the vehicle is in the desorption mode and transmits the desorption mode signal to the control unit. This application embodiment achieves modular and hierarchical control of the vehicle. The central control unit is responsible for determining the vehicle's status, and the control unit executes specific valve control actions, reducing system coupling and facilitating development and maintenance.

[0040] Optionally, the central control unit is an engine control unit or a domain controller, which communicates with the control unit via a CAN bus or a LIN bus.

[0041] In an optional implementation, the central control unit detects that the fuel tank cap is open and the engine is stopped, determines the vehicle's refueling mode, and transmits the refueling mode signal to the control unit. This application provides a reliable refueling mode triggering mechanism. Opening the fuel tank cap is a direct physical trigger condition for refueling, and stopping the engine is an important safety interlock condition; the combination of these two effectively prevents misjudgment.

[0042] Optionally, the fuel tank cap position sensor is a microswitch or a Hall effect sensor, integrated within the fuel tank cap locking mechanism. The signal from the fuel tank cap position sensor is transmitted to the central control unit via a hardwired connection or CAN bus. The engine status signal is obtained directly from the engine speed sensor signal by the central control unit.

[0043] In one optional implementation, the central control unit detects that the engine has started and the vehicle speed has been continuously higher than a preset speed for more than a second preset time, determines that the vehicle is in desorption mode, and transmits the desorption mode signal to the control unit. This embodiment ensures that desorption mode is entered after the engine has stabilized and warmed up, which helps improve desorption efficiency, avoids interference with the engine's air-fuel ratio caused by desorption at idle or low speeds, and ensures stable engine operation.

[0044] Optionally, the central control unit acquires the vehicle speed signal via the CAN bus and performs timing judgment in conjunction with the engine operating status. Specifically, when the engine control module 7 detects an RPM > 0, it determines that the engine has started. The vehicle speed sensor is installed on the transmission output shaft or the wheel. For each rotation of the wheel or transmission, the vehicle speed sensor generates a fixed number of pulses. The pulse frequency is proportional to the vehicle speed. The engine control module 7 continuously receives this pulse signal and calculates the current vehicle speed value in real time using an algorithm. The preset speed can be any value between 20 km / h and 35 km / h, and the second preset time can be any value between 1 min and 3 min.

[0045] In an optional implementation, after the central control unit detects that the vehicle is not in either the refueling mode or the desorption mode, it determines that the vehicle is in normal mode and transmits the normal mode signal to the control unit. This embodiment simplifies the control logic; when the vehicle is not in refueling mode or desorption mode, it is set to a sealed and pressurized normal mode, effectively preventing fuel vapor from evaporating and emitting during normal parking.

[0046] Optionally, if the central control unit determines that the vehicle is neither in refueling mode nor in desorption mode, it determines that the vehicle is in normal mode.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A carbon canister vent control device characterized by, The application relates to a fuel tank, a carbon tank and a control unit. The fuel tank comprises a fuel storage cavity, and an oil pump assembly is arranged in the fuel storage cavity. The carbon tank is connected with an engine through an air inlet pipe, is communicated with the fuel storage cavity through an oil gas pipeline, and is provided with an isolation valve for controlling opening and closing of the oil gas pipeline; the carbon tank is communicated with the outside through an atmosphere pipeline, and is provided with a sealing valve for controlling opening and closing of the atmosphere pipeline. The control unit is in communication connection with the isolation valve and the sealing valve. When the vehicle is in a refueling mode, the control unit controls the isolation valve and the sealing valve to be opened after receiving a refueling mode signal of the vehicle. When the vehicle is in a normal mode, the control unit controls the isolation valve and the sealing valve to be closed after receiving a normal mode signal of the vehicle. When the vehicle is in a desorption mode, the control unit controls the isolation valve to be closed and the sealing valve to be opened after receiving a desorption mode signal of the vehicle, and the engine sucks the carbon tank through the air inlet pipe. The oil pump assembly is provided with a liquid level sensor for detecting an oil level height in the fuel storage cavity.

2. The carbon can vent control device of claim 1, wherein The control unit is in communication connection with the liquid level sensor and receives a liquid level height signal transmitted by the liquid level sensor. In the refueling mode, the control unit controls the sealing valve to be closed when the received liquid level height signal is higher than a preset height value. The liquid level sensor comprises a float floating in oil and a sliding rheostat linked with the float, and the sliding rheostat is in communication connection with the control unit.

3. The carbon can vent control device of claim 2, wherein In the refueling mode, the control unit controls the sealing valve to be closed when the received liquid level height signal is higher than a preset percentage of a preset height value and a change rate of the liquid level height signal exceeds a preset change rate.

4. The carbon can vent control device of claim 3, wherein The carbon tank is provided with a pressure sensor in communication connection with the control unit, and the control unit controls the sealing valve to be opened after receiving a refueling mode signal.

5. The carbon can vent control device of claim 1, wherein The control unit controls the isolation valve to be opened after receiving a pressure value reaching a preset pressure value or after a first preset time from the pressure sensor. The isolation valve and the sealing valve are integrated into a double-position three-way electromagnetic valve, the double-position three-way electromagnetic valve has a common port connected to the carbon tank, a normally closed port connected to the oil gas pipeline, and a normally open port connected to the atmosphere pipeline.

6. The carbon can vent control device of claim 1, wherein The control unit is in communication connection with the double-position three-way electromagnetic valve to control opening and closing of the isolation valve and the sealing valve in the refueling mode, the normal mode and the desorption mode. The carbon tank emission control device further comprises a master control unit.

7. The carbon can vent control device according to any one of claims 1 to 6, characterized by The master control unit transmits the refueling mode signal to the control unit when detecting that the vehicle is in the refueling mode. The master control unit transmits the normal mode signal to the control unit when detecting that the vehicle is in the normal mode. The master control unit transmits the desorption mode signal to the control unit when detecting that the vehicle is in the desorption mode. ​ 8. The carbon can vent control device of claim 7, wherein, The total control unit detects the refueling mode of the vehicle after detecting that the fuel tank cover is opened and the engine is stopped, and transmits the refueling mode signal to the control unit.

9. The carbon can vent control device of claim 7, wherein, The total control unit detects that the vehicle is in the desorption mode after detecting that the engine is started and the vehicle speed is continuously higher than the preset speed for more than a second preset time, and transmits the desorption mode signal to the control unit.

10. The carbon can vent control device of claim 7, wherein, The total control unit detects that the vehicle is in the normal mode after detecting that the vehicle is neither in the refueling mode nor in the desorption mode, and transmits the normal mode signal to the control unit.

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