A comprehensive performance testing device and method for National VI fuel tank vent valve

Abstract

A comprehensive performance testing device for a national VI fuel tank vent valve comprises a clamping mechanism, a flipping mechanism, a testing air circuit, a control unit and n simulated fuel tanks installed on a frame; the simulated fuel tank is used to install a vent valve to be tested, the clamping mechanism is used to tighten or loosen the vent valve to be tested installed on the simulated fuel tank installation port, the flipping mechanism is used to flip the simulated fuel tank at any angle between 0° and 90°, the testing air circuit is used to deliver a testing air source to the simulated fuel tank, and the control unit is used to control the clamping mechanism, the flipping mechanism and the testing air circuit and process and display the testing data. The vent valve comprehensive performance testing device and simulation testing method meet the GM standard GMW15984 and the technical requirements of the ORVR refueling level vent valve, are close to reality, can 100% continuously test the comprehensive performance of the national VI fuel tank vent valve, have high testing efficiency and accurate testing results.

Description

Technical Field

[0001] The present invention relates to an automobile component detection device and a detection method, and in particular to a detection device and a detection method for detecting the comprehensive performance of a National VI fuel tank vent valve. Background Art

[0002] After my country implemented the National VI emission standards, higher requirements were placed on the ventilation performance of automobile fuel tanks, dynamic gasoline overflow, rollover stop, and the accuracy of rated refueling volume. The influence of automobile fuel tank vent valves on the above performance of fuel tanks is crucial. The main functions of automobile fuel tank vent valves in the fuel tank system are as follows: 1. Ventilation function: Ensure the ventilation performance of the automobile fuel tank in normal state and at a small angle tilt state, and ensure the normal pressure inside the fuel tank;

[0003] Normal state: refers to the car being parked or driven horizontally. To ensure safety and the normal performance of the car's fuel system, the vent valve should remain in a vented state in this state to ensure that the pressure in the fuel tank is equal to that outside.

[0004] Small-angle tilt state: This corresponds to the car being parked or driven on a slope. To ensure safety and the normal performance of the vehicle's fuel system, the vent valve should continue to maintain ventilation in this state to ensure that the pressure in the fuel tank is equal to that outside.

[0005] 2. Sealing performance: In the event of a vehicle rollover or tilt at a large angle (such as a rollover or overturn), to avoid secondary accidents, the vent valve must be able to remain closed and sealed.

[0006] 3. Reopening performance: After the vehicle ends its tilting state and returns to its normal state, the vent valve is required to be able to reopen normally from the closed state to ensure normal pressure inside the fuel tank and normal function of the vehicle's fuel system.

[0007] Therefore, the performance test of the fuel tank vent valve is particularly important. However, there is no special testing device for the performance test of automobile fuel tank vent valves. The main method used is manual testing one by one, which is not only complicated to operate, labor-intensive, and inefficient, but also has poor detection accuracy. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a device and a detection method that are simple in structure, economical and practical, and can quickly detect the comprehensive performance of the National VI fuel tank vent valve, so as to overcome the above-mentioned shortcomings of the existing technology.

[0009] In order to solve the above problems, the technical solution adopted by the present invention is:

[0010] A device for testing the comprehensive performance of a China VI fuel tank vent valve, characterized by comprising a frame, a clamping mechanism, a flipping mechanism, a testing air circuit, a control unit, and n simulated fuel tanks mounted on the frame; the simulated fuel tanks being used to mount the vent valve to be tested; the clamping mechanism being used to tighten or loosen the vent valve to be tested mounted on the mounting opening of the simulated fuel tank; the flipping mechanism being used to flip the simulated fuel tank at any angle between 0° and 90°; the testing air circuit being used to supply a testing air source to the simulated fuel tank; and the control unit being used to control the clamping mechanism, flipping mechanism, and testing air circuit, and to process and display test data.

[0011] The local structure of the simulated oil tank 7 is the same as that of an actual metal oil tank, and is provided with an air supply port, a test port, a safety pressure relief valve, and a mounting port for installing a vent valve to be tested. The clamping mechanism includes n rotating cylinders corresponding to the simulated oil tanks, and the rotating cylinders are respectively mounted on the upper part of the corresponding simulated oil tank mounting ports; the flipping mechanism includes a transmission shaft and a servo motor. The simulated oil tanks are mounted side by side on the test bench of the frame, and their waists are rotatably connected to the servo motor via a transmission shaft. When the servo motor is working, it drives the simulated oil tanks to rotate synchronously.

[0012] The detection air circuit includes an air source, a pressure reducing valve, a solenoid valve and a flow controller connected in sequence. The air source is connected to the air supply ports of n simulated oil tanks respectively through the pressure reducing valve, the solenoid valve and the flow controller. The detection port of the simulated oil tank is connected to a pressure sensor; the clamping mechanism, the flipping mechanism, the pressure reducing valve, the solenoid valve, the flow controller, the pressure sensor of the detection air circuit and the safety pressure relief valve of the simulated oil tank are respectively connected to the control unit circuit; the control unit includes a control module, a display screen and an indicator light; the value of the above n is any integer between 1 and 8.

[0013] A further technical solution is: an O-ring is provided on the installation opening of the simulated oil tank, and an angle sensor is provided on the transmission shaft.

[0014] Another technical solution is: a method for detecting the comprehensive performance of a National VI fuel tank vent valve, the method using a National VI fuel tank vent valve comprehensive performance detection device of the above technical solution to simulate the comprehensive performance of the National VI fuel tank vent valve, comprising the following steps:

[0015] Step 1: Preparation before testing

[0016] S11 parameter setting;

[0017] S111 sets a judgment value P for whether ventilation resistance is normal or not according to enterprise standards: when the simulated fuel tank is filled with air at a flow rate of 70 liters / minute, the pressure of the simulated fuel tank is the ventilation resistance of the vent valve at this pressure. If it exceeds the judgment value P, it means that the vent valve is not ventilating or the ventilation performance is poor, and the vent valve is judged to have poor ventilation. If it is lower than the judgment value P, the vent valve is judged to have good ventilation.

[0018] S112 sets the simulated fuel tank tilted at 30° to 45° as a small tilt angle a, simulating a state where the car is parked or driven on a slope. In this state, the vent valve should continue to maintain a vent state, that is, the pressure in the fuel tank should not exceed the judgment value P;

[0019] S113 sets the simulated fuel tank tilt of 60° to 90° as the large tilt angle b, simulating a special state of the car such as rollover or overturning. To avoid secondary accidents, the vent valve should remain closed and sealed in this state to ensure that the fuel in the tank does not leak;

[0020] S114 sets the judgment value η of whether the leakage rate is normal or not according to the enterprise standard, and if it exceeds the judgment value η, it is unqualified;

[0021] S12 test gas circuit inspection;

[0022] Check the connection between the flow controller of the test gas circuit and the gas inlet of the simulated oil tank, and the connection between the pressure sensor of the test gas circuit and the test port of the simulated oil tank to ensure that their connections are intact;

[0023] S13 installs the vent valve and sets the simulated fuel tank to the initial state;

[0024] Start the rotating cylinder to tighten the vent valve to be tested installed on the installation port of the simulated oil tank to ensure sealing, and keep the simulated oil tank in a horizontal state;

[0025] The second step is detection

[0026] S21 detects whether the ventilation valve is ventilated and the ventilation resistance in the horizontal position:

[0027] The S211 control unit opens the solenoid valve and controls the air source through the flow controller to inflate the simulated fuel tank at a flow rate of 70 liters / minute. The pressure sensor monitors the pressure in the simulated fuel tank. If the pressure displayed on the display exceeds the judgment value P and the indicator light turns red, it is determined that the ventilation valve is malfunctioning.

[0028] If the display shows that the pressure does not exceed the judgment value P and the indicator light is green, it is determined that the ventilation valve is in good condition and the next step of testing is entered;

[0029] S22 detects whether the ventilation valve is ventilated at a small angle:

[0030] The flow controller controls the air source to inflate the simulated oil tank at a flow rate of 2 liters / minute. The control unit controls the servo motor to drive the simulated oil tank to tilt to a small angle a, and monitors the pressure inside the simulated oil tank through the pressure sensor:

[0031] During this process, if the display screen shows that the pressure monitored by the pressure sensor exceeds the judgment value P and the indicator light turns red, it is determined that the ventilation valve is poorly ventilated;

[0032] If the display shows that the pressure monitored by the pressure sensor does not exceed the judgment value P and the indicator light is green, it is determined that the ventilation valve is in good condition and the next step of testing is entered;

[0033] S23 detects the sealing of the ventilation valve;

[0034] Keep the detection air line inflating the simulated oil tank at a flow rate of 2 liters / minute. The control module controls the servo motor to drive the simulated oil tank to flip to a large tilt angle b:

[0035] During the flipping process of S231, when the pressure sensor detects that the pressure in the simulated oil tank reaches 6-8 kPa, the solenoid valve is closed to stop inflation, and this pressure is used as the initial pressure P0;

[0036] S232 When the tilt reaches the maximum tilt angle b, it stays for 30 seconds, that is, the test time t is 30 seconds, and the final pressure P1 in the simulated oil tank is measured;

[0037] The S233 control module calculates the leakage rate η and displays it on the display:

[0038] If the display shows that the leakage rate exceeds the judgment value η and the indicator light is red, it is judged that the vent valve is poorly sealed;

[0039] If the display shows that the leakage rate is less than the judgment value η and the indicator light is green, the vent valve is judged to be sealed and the next step of testing is carried out;

[0040] S24 detects the reopening performance of the ventilation valve;

[0041] Keep the solenoid valve closed to maintain the final pressure P1 in the simulated oil tank. The control module controls the servo motor to reverse and return the simulated oil tank to the normal position. When it returns to the small tilt angle a, the pressure sensor detects the pressure in the simulated oil tank:

[0042] If the pressure value detected by the pressure sensor shown on the display screen at S241 is greater than the judgment value P, it means that the vent valve has not reopened normally and the pressure has not been released. If the indicator light is red, the reopening performance of the vent valve is judged to be unqualified. The safety relief valve of the simulated fuel tank is opened to release the pressure.

[0043] If the pressure value detected by the pressure sensor shown on the display screen at S242 is lower than the judgment value P, it means that the vent valve has reopened normally and the pressure has been released, and the indicator light is green, then the reopening performance of the vent valve is judged to be qualified;

[0044] S3 starts the rotary cylinder to open the vent valve, ending the test.

[0045] Due to the adoption of the above technical solution, the comprehensive performance detection device and detection method of the National VI fuel tank vent valve of the present invention have the following beneficial effects:

[0046] 1. This invention provides an online device and method for testing the comprehensive performance of China VI fuel tank vent valves using a simulated equivalence method (from liquid testing to gas testing). This device and method can continuously test the comprehensive performance of China VI fuel tank vent valves.

[0047] The test method complies with General Motors standard GMW15984 Specification for Onboard Refueling Vapor Recovery (ORVR) Shutoff Valve Component (ORVR fuel level vent valve technical requirements);

[0048] 2. This device, a comprehensive performance testing device for fuel tank vent valves compliant with China VI emission standards, uses a control module to control the flip mechanism and test air path. It also simulates the feedback signal from the fuel tank pressure sensor to automatically collect and process data, thereby determining the performance of the vent valve in various states. The results are intuitively communicated to the tester via a display screen. The entire testing process is automated, highly efficient, and accurate.

[0049] 3. An O-ring seal is installed at the simulated fuel tank mounting port to ensure a secure and sealed connection with the vent valve. An angle sensor is installed on the drive shaft 10 to visually display the simulated fuel tank's tilt angle during simulated small and large tilt angles, ensuring that the test results are close to reality.

[0050] 4. The simulated fuel tank's partial structure is identical to that of the metal tank's, effectively detecting deformation of the vent valve's flange surface. (Because the valve is ultimately mounted on the tank, if the simulated fuel tank's partial structure is identical to that of the metal tank's, deformation of the flange surface between the vent valve and the tank can also be detected.)

[0051] 5. The present invention provides a comprehensive performance testing device for fuel tank vent valves meeting China VI emission standards. Its flipping mechanism can drive multiple simulated fuel tanks via a transmission shaft, allowing simultaneous testing of multiple products, thereby significantly improving testing efficiency.

[0052] The technical features of the National VI fuel tank vent valve comprehensive performance detection device and detection method of the present invention are further explained below in conjunction with the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a schematic diagram of the control principle of the detection air circuit of a National VI fuel tank vent valve comprehensive performance detection device of the present invention;

[0054] Figure 2 This is a schematic structural diagram of the flipping mechanism and clamping mechanism of a National VI fuel tank vent valve comprehensive performance testing device of the present invention;

[0055] Figure 3 This is a physical diagram of a comprehensive performance testing device for a fuel tank vent valve complying with China VI standards of the present invention;

[0056] Figure 4 This is a schematic diagram of the simulated fuel tank structure;

[0057] In the picture:

[0058] 100—Control unit, 101—Indicator light, 102—Display screen, 1—Air source, 2—Pressure reducing valve, 3—Solenoid valve, 4—Flow controller, 5—Pressure sensor, 6—Vent valve, 7—Simulated oil tank, 71—Air supply port, 72—Installation port, 73—Detection port, 74—Safety pressure relief valve, 8—Rotary cylinder, 9—Servo motor, 10—Drive shaft, 11—Angle sensor, 12—Frame. DETAILED DESCRIPTION

[0059] Example 1

[0060] A device for testing the comprehensive performance of a China VI fuel tank vent valve comprises a frame 12, a clamping mechanism, a flipping mechanism, a testing air circuit, a control unit, and four simulated fuel tanks mounted thereon; the simulated fuel tanks being used to mount the vent valves to be tested; the clamping mechanism being used to tighten or loosen the vent valves to be tested mounted on the mounting openings of the simulated fuel tanks; the flipping mechanism being used to flip the simulated fuel tanks at any angle between 0° and 90°; the testing air circuit being used to deliver a testing air source to the simulated fuel tanks; and the control unit being used to control the clamping mechanism, flipping mechanism, and testing air circuits and to process and display test data.

[0061] The local structure of the simulated oil tank 7 is the same as that of an actual metal oil tank, and is provided with an air supply port 71, a test port 73, a safety pressure relief valve 74, and a mounting port 72 for mounting the vent valve to be tested. The clamping mechanism includes four rotating cylinders 8 corresponding to the simulated oil tanks, and the rotating cylinders are respectively mounted on the upper part of the corresponding simulated oil tank mounting ports; the flipping mechanism includes a transmission shaft 10 and a servo motor 9. The simulated oil tank 7 is mounted side by side on the test bench of the frame, and its waist is rotatably connected to the servo motor 9 via the transmission shaft 10. When the servo motor is working, it drives the simulated oil tank to rotate synchronously.

[0062] The detection gas circuit includes an air source 1, a pressure reducing valve 2, a solenoid valve 3 and a flow controller 4 connected in sequence. The air source 1 is connected to the air supply ports 71 of the four simulated oil tanks through the pressure reducing valve 2, the solenoid valve 3 and the flow controller 4. The detection ports 73 of the four simulated oil tanks are respectively connected to the pressure sensors 5.

[0063] The clamping mechanism, the flipping mechanism, the pressure reducing valve 2 for detecting the gas path, the solenoid valve 3, the flow controller 4, the pressure sensor 5 and the safety pressure relief valve 74 of the simulated oil tank are respectively connected to the control unit circuit;

[0064] The control unit 100 includes a control module, a display screen 102 and an indicator light 101;

[0065] The mounting openings of the simulated oil tank are all provided with O-rings to ensure sealing when connected to the vent valve; an angle sensor is provided on the transmission shaft to visually display the simulated reversal angle.

[0066] As a variation of the above embodiment, the number of the simulated fuel tanks can be increased or decreased according to actual needs, and is generally any integer between 1 and 8.

[0067] Example 2

[0068] A method for testing the comprehensive performance of a China VI fuel tank vent valve, the method utilizing the China VI fuel tank vent valve comprehensive performance testing device described in Example 1 to simulate testing the comprehensive performance of the China VI fuel tank vent valve, comprising the following steps:

[0069] Step 1: Preparation before testing

[0070] S11 parameter setting;

[0071] S111 sets a judgment value P for whether ventilation resistance is normal or not according to enterprise standards: when the simulated fuel tank is filled with air at a flow rate of 70 liters / minute, the pressure of the simulated fuel tank is the ventilation resistance of the vent valve at this pressure. If it exceeds the judgment value P, it means that the vent valve is not ventilating or the ventilation performance is poor, and the vent valve is judged to have poor ventilation. If it is lower than the judgment value P, the vent valve is judged to have good ventilation.

[0072] S112 sets the simulated fuel tank tilted at 30° to 45° as a small tilt angle a, simulating a state where the car is parked or driven on a slope. In this state, the vent valve should continue to maintain a vent state, that is, the pressure in the fuel tank should not exceed the judgment value P;

[0073] S113 sets the simulated fuel tank tilt of 60° to 90° as the large tilt angle b, simulating a special state of the car such as rollover or overturning. To avoid secondary accidents, the vent valve should remain closed and sealed in this state to ensure that the fuel in the tank does not leak;

[0074] S114 sets the judgment value η of whether the leakage rate is normal or not according to the enterprise standard, and if it exceeds the judgment value η, it is unqualified;

[0075] S12 test gas circuit inspection;

[0076] Check the connection between the flow controller of the test gas circuit and the gas inlet of the simulated oil tank, and the connection between the pressure sensor of the test gas circuit and the test port of the simulated oil tank to ensure that their connections are intact;

[0077] S13 installs the vent valve and sets the simulated fuel tank to the initial state;

[0078] Start the rotating cylinder to tighten the vent valve to be tested installed on the installation port of the simulated oil tank to ensure sealing, and keep the simulated oil tank in a horizontal state;

[0079] The second step is detection

[0080] S21 detects whether the ventilation valve is ventilated and the ventilation resistance in the horizontal position:

[0081] The S211 control unit opens the solenoid valve and controls the air source to fill the simulated fuel tank at a flow rate of 70 liters / minute through the flow controller. The pressure sensor monitors the pressure in the simulated fuel tank. If the display shows that the pressure exceeds the judgment value P ， If the indicator light is red, it means that the ventilation valve is poorly ventilated;

[0082] If the display shows that the pressure does not exceed the judgment value P and the indicator light is green, it is determined that the ventilation valve is in good condition and the next step of testing is entered;

[0083] S22 detects whether the ventilation valve is ventilated at a small angle:

[0084] The flow controller controls the air source to inflate the simulated oil tank at a flow rate of 2 liters / minute. The control unit controls the servo motor to drive the simulated oil tank to tilt to a small angle a, and monitors the pressure in the simulated oil tank through the pressure sensor:

[0085] During this process, if the display screen shows that the pressure monitored by the pressure sensor exceeds the judgment value P and the indicator light turns red, it is determined that the ventilation valve is poorly ventilated;

[0086] If the display shows that the pressure monitored by the pressure sensor does not exceed the judgment value P and the indicator light is green, it is determined that the ventilation valve is in good condition and the next step of testing is entered;

[0087] S23 detects the sealing of the ventilation valve;

[0088] Keep the detection air line inflating the simulated oil tank at a flow rate of 2 liters / minute. The control module controls the servo motor to drive the simulated oil tank to flip to a large tilt angle b:

[0089] During the flipping process of S231, when the pressure sensor detects that the pressure in the simulated oil tank reaches 6-8 kPa, the solenoid valve is closed to stop inflation, and this pressure is used as the initial pressure P0;

[0090] S232 When the rollover reaches the maximum tilt angle b, it stays for 30 seconds, that is, the test time t is 30 seconds, and the final pressure P1 in the simulated oil tank is measured;

[0091] The S233 control module calculates the leak rate and displays it on the display:

[0092] If the display shows that the leakage rate exceeds the judgment value η and the indicator light is red, it is judged that the vent valve is poorly sealed;

[0093] If the display shows that the leakage rate is less than the judgment value η and the indicator light is green, the vent valve is judged to be sealed and the next step of testing is carried out;

[0094] S24 detects the reopening performance of the ventilation valve;

[0095] Keep the solenoid valve closed to maintain the final pressure P1 in the simulated oil tank. The control module controls the servo motor to reverse and return the simulated oil tank to the normal position. When it returns to the small tilt angle a, the pressure sensor detects the pressure in the simulated oil tank:

[0096] If the pressure value detected by the pressure sensor shown on the display screen at S241 is greater than the judgment value P, it means that the vent valve has not reopened normally and the pressure has not been released. If the indicator light is red, the reopening performance of the vent valve is judged to be unqualified. The safety relief valve of the simulated fuel tank is opened to release the pressure.

[0097] S242 If the display shows that the pressure value detected by the pressure sensor is lower than the judgment value P, it means that the vent valve is reopened normally, the pressure is released, and the indicator light is green, then it is determined that the reopening performance of the vent valve is qualified and the test is completed.

[0098] Notes:

[0099] (1) The ventilation resistance of the valve is a relatively important performance. When testing whether the vent valve is ventilated and the ventilation resistance in the horizontal position, the test air circuit needs to be filled with air to the simulated oil tank at a flow rate of 70 liters / minute. When testing whether the vent valve is ventilated at a small angle, it is mainly used to detect whether the vent valve is closed. The test air circuit only needs to be filled with air to the simulated oil tank at a flow rate of 2 liters / minute. If it is closed, 2 liters / minute is enough to build up a large pressure for judgment;

[0100] (2) The ventilation resistance judgment value P mentioned in this article refers to the pressure in the simulated fuel tank relative to the external pressure being no greater than 0.25 kPa, that is, the "absolute pressure" in the fuel tank is no greater than 101.325 kPa; the judgment value P for whether the ventilation resistance is normal or not can be set according to the enterprise standard, generally 0.25 kPa;

[0101] (3) The judgment value η of whether the leakage rate is normal or not is set according to the enterprise standard, generally 50 ml / min;

[0102] (4) When conducting a tilted large angle b leakage rate test, the general test time t is 0.5 minutes (30 seconds), which is determined by balancing output efficiency and detection effectiveness. The company can set the time by itself;

[0103] (5) The formula for calculating the leakage rate is:

[0104]

[0105] Where:

[0106] η is the leakage rate in milliliters per minute;

[0107] P0 is the initial pressure in the container, in kilopascals;

[0108] △P is the pressure change value, which is the final pressure P1 minus the initial pressure P0, and the unit is kilopascal;

[0109] V is the simulated fuel tank volume in milliliters;

[0110] t is the test time in minutes.

Claims

1. A comprehensive performance testing device for a fuel tank vent valve of National VI Standard, characterized in that: It comprises a frame (12) and a clamping mechanism, a flipping mechanism, a detection air circuit, a control unit and n simulated oil tanks installed on the frame; the simulated oil tank is used to install a vent valve to be tested, the clamping mechanism is used to tighten or loosen the vent valve to be tested installed on the mounting port of the simulated oil tank, the flipping mechanism is used to flip the simulated oil tank arbitrarily between 0° and 90°, the detection air circuit is used to deliver a detection air source to the simulated oil tank, and the control unit is used to control the clamping mechanism, the flipping mechanism and the detection air circuit and to process and display the detection data; The local structure of the simulated oil tank (7) is the same as the local structure of an actual metal oil tank, and is provided with an air delivery port (71), a detection port (73), a safety pressure relief valve (74), and a mounting port (72) for mounting a vent valve to be detected. The clamping mechanism comprises n rotating cylinders (8) corresponding to the simulated oil tanks, and the rotating cylinders are respectively mounted on the upper part of the corresponding mounting ports of the simulated oil tanks. The flipping mechanism comprises a transmission shaft (10) and a servo motor (9). The simulated oil tank (7) is mounted side by side on a test bench of a frame, and its waist is rotationally connected to the servo motor (9) via the transmission shaft (10). When the servo motor is in operation, it drives the simulated oil tank to rotate synchronously. The detection gas circuit comprises an air source (1), a pressure reducing valve (2), an electromagnetic valve (3) and a flow controller (4) which are connected in sequence; the air source (1) is connected to the air supply port (71) of the simulated oil tank through the pressure reducing valve (2), the electromagnetic valve (3) and the flow controller (4); the detection port (73) of the simulated oil tank is connected to a pressure sensor (5); The clamping mechanism, the flipping mechanism, the pressure reducing valve (2) for detecting the gas path, the solenoid valve (3), the flow controller (4), the pressure sensor (5) and the safety pressure relief valve (74) of the simulated oil tank are respectively connected to the control unit circuit; The control unit (100) comprises a control module, a display screen (102) and an indicator light (101); The value of n is any integer between 1 and 8.

2. A comprehensive performance testing device for a fuel tank vent valve of National VI Standard according to claim 1, characterized in that: The mounting opening (72) of the simulated oil tank is provided with an O-type sealing ring, and the transmission shaft (10) is provided with an angle sensor (11).

3. A method for detecting the comprehensive performance of a National VI fuel tank vent valve, characterized in that: The detection method is a method for simulating the comprehensive performance of the National VI fuel tank vent valve by using the National VI fuel tank vent valve comprehensive performance detection device described in claim 2, comprising the following steps: Step 1: Preparation before testing S11 parameter setting; S111 sets the judgment value P of whether the ventilation resistance is normal or not according to the enterprise standard: when the simulated oil tank is inflated at a flow rate of 70 liters / minute, the pressure of the simulated oil tank is the ventilation resistance of the vent valve at this pressure. If it exceeds the judgment value P, it means that the vent valve is not ventilated or the ventilation performance is poor, and the vent valve is judged to be poorly ventilated. If it is lower than the judgment value P, the vent valve is judged to be well ventilated. S112 sets the simulated fuel tank tilted at 30° to 45° as a small tilt angle a, simulating the state of the car parking or driving on a slope. The vent valve should continue to maintain the venting state in this state, that is, the pressure in the fuel tank is not greater than the judgment value P; S113 sets the simulated fuel tank to tilt 60° to 90° as the large tilt angle b, simulating the vehicle being in a special state of rollover or overturning. To avoid a secondary accident, the vent valve should be kept closed and sealed in this state to ensure that the fuel in the fuel tank does not leak; S114 sets the judgment value η of whether the leakage rate is normal or not according to the enterprise standard, and if it exceeds the judgment value η, it is unqualified; S12 gas circuit inspection; Check the connection between the flow controller of the test gas circuit and the gas delivery port of the simulated oil tank, and the connection between the pressure sensor of the test gas circuit and the test port of the simulated oil tank, and ensure that their connections are intact; S13 installs the vent valve and sets the simulated fuel tank to the initial state; Start the rotating cylinder to tighten the vent valve to be tested installed at the installation port of the simulated oil tank to ensure sealing, and keep the simulated oil tank in a horizontal state; Step 2: Detection S21 detects whether the ventilation valve is ventilated and the ventilation resistance in the horizontal position: The S211 control unit opens the solenoid valve and controls the air source to charge the simulated oil tank at a flow rate of 70 liters / minute through the flow controller. The pressure in the simulated oil tank is monitored by the pressure sensor. If the pressure displayed on the display exceeds the judgment value P and the indicator light turns red, it is determined that the ventilation valve is poorly ventilated; S212 If the display shows that the pressure does not exceed the judgment value P and the indicator light is green, it is determined that the ventilation valve is well ventilated and the next step of testing is entered; S22 detects whether the ventilation valve is ventilated at a small angle: The flow controller controls the air source to inflate the simulated oil tank at a flow rate of 2 liters / minute. The control unit controls the servo motor to drive the simulated oil tank to flip to a small tilt angle a, and monitors the pressure in the simulated oil tank through the pressure sensor: S221 During this process, if the display screen shows that the pressure monitored by the pressure sensor exceeds the judgment value P and the indicator light is red, it is judged that the ventilation valve is poorly ventilated; S222 If the display shows that the pressure monitored by the pressure sensor does not exceed the judgment value P, and the indicator light is green, it is determined that the ventilation valve is well ventilated, and the next step of detection is entered; S23 detects the tightness of the ventilation valve; Keep the detection gas line filling the simulated oil tank at a flow rate of 2 liters / minute. The control module controls the servo motor to drive the simulated oil tank to flip to a large tilt angle b: During the flipping process of S231, when the pressure sensor detects that the pressure in the simulated oil tank reaches 6-8 kPa, the solenoid valve is closed to stop the inflation, and this pressure is used as the initial pressure P0; S232 When the overturn reaches the maximum tilt angle b, it stays for 30 seconds, that is, the test time t is 30 seconds, and the final pressure P1 in the simulated oil tank is measured; The S233 control module calculates the leak rate and displays it on the display: If the display shows that the leakage rate exceeds the judgment value η, and the indicator light turns red, it is judged that the air valve has poor sealing; If the leakage rate displayed on the display screen is less than the judgment value η and the indicator light is green, it is determined that the air valve is sealed and the next step of testing is carried out; S24 detects the reopening performance of the ventilation valve; Keep the solenoid valve closed to keep the final pressure P1 in the simulated oil tank. The control module controls the servo motor to reverse and return the simulated oil tank to the normal position. When the simulated oil tank returns to the normal position at a small tilt angle a, the pressure sensor detects the pressure in the simulated oil tank: S241 If the display shows that the pressure value detected by the pressure sensor is greater than the judgment value P, it means that the vent valve has not been reopened normally and the pressure has not been released. The indicator light is red, and it is determined that the reopening performance of the vent valve is unqualified. Open the safety pressure relief valve of the simulated oil tank to release the pressure. S242 If the display shows that the pressure value detected by the pressure sensor is lower than the judgment value P, it means that the ventilation valve is reopened normally, the pressure is released, and the indicator light is green, then it is judged that the reopening performance of the ventilation valve is qualified; S3 starts the rotary cylinder to open the vent valve, ending the test.

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