Fuel system detection device and detection method thereof

Abstract

The present invention discloses a fuel system detection device and a detection method thereof, comprising a constant pressure sealed chamber, a heat exchanger, an FID tester and a plurality of collecting air bags arranged inside the constant pressure sealed chamber, wherein the constant pressure sealed chamber is used to place the fuel system; the heat exchanger is arranged on the constant pressure sealed chamber; the collecting air bags are arranged inside the constant pressure sealed chamber, and the carbon canister is respectively connected with each of the collecting air bags and the inside of the constant pressure sealed chamber; the FID detector is respectively connected with each of the collecting air bags and the constant pressure sealed chamber; the connecting pipelines of the constant pressure sealed chamber, the collecting air bags, the carbon canister and the FID detector are all provided with on-off valves. The present invention proposes a fuel system detection device and a detection method thereof, which can simultaneously perform a carbon canister test and a fuel system permeation emission test under the same environment, thereby improving the test accuracy and test efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile detection, and in particular to a fuel system detection device and a detection method thereof. Background Art

[0002] The fuel system provides fuel to the engine, including a fuel tank and a carbon canister connected to the fuel tank. As the country's requirements for automobile emissions continue to upgrade, the requirements for testing the permeation emissions of the fuel system are also getting higher and higher. Existing detection devices can only test the carbon canister in the fuel system or the carburization emissions of the fuel system. Usually, a single closed chamber is used to measure the permeation emissions of the fuel system alone, or the carbon canister port emissions are measured alone through the air bag method. Only one of the two tests can be measured at the same time, which has low test efficiency and wastes a lot of time and cost. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a fuel system detection device that can simultaneously perform a carbon canister emission test and a fuel system permeation emission test under the same environment, thereby improving the test accuracy and test efficiency.

[0004] The present invention also provides a detection method for the fuel system detection device.

[0005] According to the first aspect of the present invention, the fuel system collecting device comprises a constant pressure sealed chamber, a heat exchanger, an FID tester and a plurality of collecting air bags arranged inside the constant pressure sealed chamber, wherein the constant pressure sealed chamber is used to place the fuel system; the heat exchanger is arranged on the constant pressure sealed chamber; the collecting air bags are arranged inside the constant pressure sealed chamber, and the carbon canister is respectively connected with each of the collecting air bags and the interior of the constant pressure sealed chamber; the FID detector is respectively connected with each of the collecting air bags and the constant pressure sealed chamber; and the connecting pipelines of the constant pressure sealed chamber, the collecting air bags, the carbon canister and the FID detector are all provided with on-off valves.

[0006] The fuel system collecting device according to the embodiment of the present invention has at least the following beneficial effects: a constant pressure sealed chamber and a heat exchanger are used to simulate the environment, the carbon canister and the fuel tank assembly are placed in the constant pressure sealed chamber, the constant pressure sealed chamber and the carbon canister port are respectively connected through an FID detector, the permeates in the fuel system are discharged in the constant pressure sealed chamber, the FID detector measures the permeate emission parameters of the fuel system by testing the gas in the constant pressure sealed chamber, during the environmental change process, the collecting air bag collects the emissions in the carbon canister port, and after inflation, the emissions are sent to the FID detector for detection, thereby achieving simultaneous emission testing of the carbon canister port and the fuel system under the same simulated environment, ensuring the test accuracy, greatly improving the test efficiency, and making the test very convenient.

[0007] According to some embodiments of the present invention, an atmospheric pipe and a compressed gas delivery pipe are also included. The FID detector is connected to each of the collecting air bags through an air bag detection pipe, and the atmospheric pipe, the air bag detection pipe and the compressed gas delivery pipe are connected in sequence.

[0008] According to some embodiments of the present invention, the air bag detection tube or the compressed gas delivery tube is also connected to a vacuum pump, a valve nine is provided between the vacuum pump and the air bag detection tube or the compressed gas delivery tube, and the outside of the vacuum pump is connected to the atmosphere.

[0009] According to some embodiments of the present invention, the compressed gas delivery pipe is connected to an air inlet pipe and a flow meter.

[0010] According to some embodiments of the present invention, the carbon canister is connected to each of the collecting air bags through an air bag collecting pipe, and the atmospheric pipe, the air bag collecting pipe and the compressed gas delivery pipe are connected in sequence.

[0011] According to some embodiments of the present invention, the constant-pressure closed chamber includes a box body and a movable constant-pressure plate, wherein the movable constant-pressure plate is arranged on the top of the box body and can move up and down, and the box body and the movable constant-pressure plate form a closed chamber with variable volume, wherein a pressure sensor is provided in the closed chamber.

[0012] According to some embodiments of the present invention, a closed cavity capacity tester is provided outside the constant pressure closed chamber, and the closed cavity capacity tester includes a measuring ruler fixedly connected to the movable constant pressure plate and a zero position plate arranged on the outer wall of the box body and covering the measuring ruler.

[0013] According to some embodiments of the present invention, a driving motor is provided on the outside of the box body, and the driving motor is connected to the moving constant pressure plate through a screw pair and drives the moving constant pressure plate to move.

[0014] The detection method of the fuel system detection device according to the second embodiment of the present invention includes a fuel system permeation emission detection process and a carbon canister emission detection process.

[0015] The fuel system carburization emission detection process includes the following detection steps: the fuel system is placed in a constant pressure closed chamber, the FID detector is connected to the inside of the constant pressure closed chamber, and the gas collected in the constant pressure closed chamber is passed into the FID detector for detection;

[0016] The carbon canister emission detection process includes the following detection steps: a) the heat exchanger controls the temperature inside the constant pressure closed chamber to decrease or increase; b) when the temperature decreases, the carbon canister port is connected to a collecting air bag, and the collecting air bag collects the gas emitted from the carbon canister port; when the temperature increases, the carbon canister port is connected to the inside of the constant pressure closed chamber, and the gas in the constant pressure closed chamber flows back into the carbon canister; c) after the collecting air bag collects the gas emitted from the carbon canister port, it is connected to the FID detector and the gas is passed into the FID detector for detection.

[0017] The detection method of the fuel system detection device according to the embodiment of the present invention has at least the following beneficial effects: the method integrates the carbon canister emission detection and the fuel system penetration emission detection, and can simultaneously perform the carbon canister emission detection and the fuel system penetration emission detection process, thereby improving the detection accuracy and detection efficiency, and solving the inconvenience problem caused by separate detection; a constant pressure closed chamber and an air bag structure are used to simultaneously detect the carbon canister emission and the fuel system penetration process, thereby ensuring that the carbon canister and the fuel system detection are in the same environment, with higher detection accuracy, more in line with the actual penetration and emission process of the automobile fuel system, and more accurate and effective detection and experimental data.

[0018] According to some embodiments of the present invention, the carbon canister emission detection process further includes the following air bag expansion step: the compressed gas delivery pipe delivers compressed air to the collecting air bag until the air pressure in the collecting air bag reaches a set value.

[0019] According to some embodiments of the present invention, the following air bag cleaning process is also included: after the FID detector detects the gas in the collection air bag, the vacuum pump extracts the gas in the collection air bag, and re-introduces compressed air into the collection air bag through the compressed gas delivery pipe. After the air bag expands, it continues to be extracted through the vacuum pump, and this process is repeated multiple times. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 is a schematic diagram of the external structure of an embodiment of the present invention;

[0022] Figure 2 Schematic diagram of the internal structure of an embodiment of the present invention;

[0023] Figure 3 for Figure 2 A schematic diagram of the internal structure of the pipeline box is shown;

[0024] Figure 4 This is a schematic diagram of the structure of the pipeline box when the first collecting air bag collects gas;

[0025] Figure 5A schematic diagram of the structure of the pipeline box when the second collecting air bag collects gas;

[0026] Figure 6 A schematic diagram of the structure of the pipeline box when the pipeline gas cleaning assembly cleans the air bag collection pipe;

[0027] Figure 7 A schematic diagram of the structure of the pipeline box when the pipeline gas cleaning assembly cleans the air bag detection tube;

[0028] Figure 8 This is a schematic diagram of the structure of the pipeline box when the FID detector is connected to the first collection air bag;

[0029] Fig. 9 This is a schematic diagram of the structure of the pipeline box when the FID detector is connected to the second collection air bag.

[0030] Constant pressure sealed chamber 100, box body 110, movable constant pressure plate 120, sealed chamber capacity tester 130, measuring ruler 131, zero plate 132, perspective window 140, drive motor 150, pipeline box 200, branch pipe 1 201, branch pipe 2 202, branch pipe 3 203, branch pipe 4 204, branch pipe 5 205, branch pipe 6 206, branch pipe 7 207, branch pipe 208, upper pipeline 210, valve 1 211, valve 2 212, valve 3 213, valve 4 214, lower pipeline 220, valve 5 221, valve 6 222, valve 7 223, valve 8 224, valve 9 225, two-position three-way valve 1 23 0, two-position three-way valve 240, compressed gas delivery pipe 250, pressure gauge 251, flow meter 252, PLC control box 260, pressure gauge 270, vacuum pump 280, collection air bag 300, first collection air bag 310, second collection air bag 320, FID detector 400, heat exchanger 500, circulation fan 600, anemometer 610, atmospheric pipe 700, temperature sensor 800, intelligent collector 900, outer shell 910, collection pipe 911, rotating inner shell 920, connection port 921, inner tube 922, rotating motor 930, angle sensor 940, connecting bearing 950 DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0034] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0035] Reference Figure 1 and Figure 2 , the fuel system detection device according to an embodiment of the present invention is described below.

[0036] like Figure 1 and Figure 2 As shown, a fuel system detection device includes a constant pressure sealed chamber 100, a heat exchanger 500, a collecting air bag 300 and an FID detector 400. The constant pressure sealed chamber 100 is used to place the fuel system and collect the permeated gas of the fuel system. The constant pressure in the constant pressure sealed chamber 100 is atmospheric pressure. The heat exchanger 500 is used to change the temperature of the constant pressure sealed chamber 100 to simulate the weather changes of a day. Since the temperature of the environment will change continuously during a day, the atmospheric pressure is maintained during the continuous change of the indoor temperature, so that the fuel system is in a simulated environment of the external environment. The permeate in the fuel system penetrates into the constant pressure sealed chamber 100. The collecting air bag 300 is used to collect the gas discharged from the carbon canister port during the change of the ambient temperature. The FID detector 400 is used to detect the gas collected in the air bag and the gas permeated from the constant pressure sealed chamber 100. It should be noted that the fuel system is an important component of a car or other mechanical vehicle. The carbon canister is a part of the fuel system and is installed between the fuel tank and the engine. Since gasoline is a volatile liquid, the fuel tank is often filled with vapor at room temperature. The carbon canister mainly stores the fuel vapor in the fuel tank. The carbon canister is provided with three ports, one connected to the fuel tank, one connected to the engine, and one connected to the atmosphere. The carbon canister port for connecting the air bag mentioned in this specification is the carbon canister port connected to the atmosphere.

[0037] A plurality of collecting air bags 300 are provided, and the number of collecting air bags 300 can be 1, 2 or more than 2. The carbon canister port is respectively connected with each collecting air bag 300 and the interior of the constant pressure sealed chamber 100, that is, the carbon canister port and all collecting air bags 300 have separate connecting pipes. In addition, the carbon canister port is also connected with the interior of the constant pressure sealed chamber 100 through another connecting pipe. The connecting pipes between the carbon canister port and the collecting air bag 300 and the interior of the constant pressure sealed chamber 100 are all provided with on-off valves, and the on-off valves are used to control the connection between the carbon canister port and a certain collecting air bag 300 or the constant pressure sealed chamber 100. When the temperature in the constant-pressure sealed chamber 100 rises, the gas in the fuel system expands, and the carbon canister port is controlled to be connected only to a certain collecting air bag 300, and other connecting pipes are closed. The gas in the fuel system expands and is discharged through the carbon canister port, and the collecting air bag 300 collects the carbon canister gas discharged at this time; when the temperature inside the constant-pressure sealed chamber 100 decreases, the gas in the fuel system contracts. In order to keep the air pressure in the fuel system consistent with the atmospheric pressure, the carbon canister port is controlled to be connected only to the inside of the constant-pressure sealed chamber 100, and the gas in the constant-pressure sealed chamber 100 flows into the carbon canister port.

[0038] The FID detector 400 is connected to each collecting air bag 300 and the interior of the constant-pressure sealed chamber 100 respectively, that is, the FID detector 400 has separate connecting pipes with all the air bags. In addition, the FID detector 400 is also connected to the interior of the constant-pressure sealed chamber 100 through another connecting pipe. The connecting pipes between the FID detector 400 and all the collecting air bags 300 and the interior of the constant-pressure sealed chamber 100 are provided with on-off valves, and the on-off valves are used to control the connection between the FID detector 400 and a certain collecting air bag 300 or the constant-pressure sealed chamber 100. After a certain collecting air bag 300 has collected the carbon canister gas discharged from the carbon canister port, other connecting pipes connected to the FID detector 400 are closed, and the FID is controlled to be connected only to the collecting air bag 300 through the on-off valve, and the exhaust gas collected by the collecting air bag 300 is passed into the FID detector 400 through the connecting pipe for detection; since the constant pressure closed chamber 100 collects the permeate emissions in the fuel system, when the FID detector 400 is only connected to the constant pressure closed chamber 100, that is, the on-off valve on the FID detector 400 that is only connected to the constant pressure closed chamber 100 is opened, and other on-off valves are closed, the FID detector 400 detects the permeate emissions collected in the constant pressure closed chamber 100 and tests the permeate emissions of the fuel system.

[0039] Specifically, in this embodiment, there are two collecting air bags 300, and the two collecting air bags 300 are used to collect the gas discharged from the carbon canister port respectively. The two collecting air bags 300 can be used to collect the exhaust gas when simulating the temperature rise in two days, and one of the collecting air bags 300 collects the exhaust gas for one day, so as to facilitate the emission test comparison process of the carbon canister port. In addition, when there are more than two collecting air bags 300, each collecting air bag 300 can also be used to collect the carbon canister emissions for one day, and collect and detect them for comparison. The FID detector 400 is a flame ionization detector, which is a high-sensitivity general-purpose detector. It responds to almost all organic matter, but has no response or very small response to inorganic matter, inert gas or substances that do not dissociate in the flame. It is a detection device used in carbon canister emissions and fuel system permeation emissions.

[0040] In some embodiments of the present invention, an atmospheric pipe 700 and a compressed gas delivery pipe 250 are also included. The FID detector 400 is connected to each collection air bag 300 through an air bag detection pipe. The atmospheric pipe 700, the air bag detection pipe, and the compressed gas delivery pipe 250 are connected in sequence. The air bag detection pipe is equivalent to the delivery main pipe when all the collection air bags 300 are connected to the FID detector 400. The main pipe branches out a number of branch pipes corresponding to the collection air bags 300, and each branch pipe is provided with an on-off valve. The atmospheric pipe 700 and the compressed gas delivery pipe 250 are connected to the two ends of the air bag detection pipe respectively. The compressed gas enters the air bag detection pipe from the compressed gas delivery pipe 250, and the residual gas in the air bag detection pipe is discharged to prevent the residual gas during the detection of the collection air bag 300 from affecting the subsequent air bag detection process. The outside of the compressed gas delivery pipe 250 is connected to the air compressor to provide compressed gas to clean the gas in the connecting pipe. In addition, the compressed air in the compressed gas delivery pipe 250 is not only used to clean the gas in the pipeline, but also used to inflate the collecting air bag 300. After the collection is completed, the compressed air is delivered to the collecting air bag 300 through the compressed gas delivery pipe 250, and the collecting air bag 300 expands to an appropriate size to keep the air pressure in the collecting air bag 300 at a constant value. The volume of the air bag under this constant pressure value is constant, and the FID detector 400 detects the gas of the collected gas 300 under this air pressure, and obtains the accurate value of the carbon canister emission by detecting the gas concentration at this time and multiplying it by the volume of the collecting air bag at this time.

[0041] In addition, the carbon canister is connected to each collecting air bag 300 through an air bag collecting pipe, and the atmospheric pipe 700, the air bag collecting pipe, and the compressed gas delivery pipe 250 are connected in sequence. The air bag collecting pipe is equivalent to a collecting main pipe connecting all the collecting air bags 300 with the carbon canister. Several branch pipes corresponding to the collecting air bags 300 are branched out from the main pipe, and each branch pipe is provided with an on-off valve.

[0042] It should be noted that the atmospheric pipe 700 is directly connected to the atmosphere outside the constant pressure sealed chamber 100 , and is not connected to the interior of the constant pressure sealed chamber 100 or the collecting air bag 300 .

[0043] Specifically, the compressed gas delivery pipe 250 is connected to an air intake pipe 251 and a flow meter 252. The air intake pipe 251 is externally connected to an air compressor. The compressed air enters the compressed gas delivery pipe 250 from the air intake pipe 251 and is then delivered to the air bag detection tube. The flow meter 252 is used to calculate the gas flow in the air intake pipe 251 so as to observe the delivery condition of the compressed air in the compressed gas delivery pipe 250.

[0044] In some embodiments of the present invention, the constant pressure closed chamber 100, the FID detector 400 and the air bag detection tube are connected via a two-position three-way valve. The two-position three-way valve can control the FID detector 400 to be connected to the air bag or to the constant pressure closed chamber 100, thereby controlling the detection direction of the FID detector 400.

[0045] In some embodiments of the present invention, a circulating fan 600 is provided in the constant pressure closed chamber 100, and an anemometer 610 is provided on the front side of the circulating fan 600. The anemometer 610 can be installed on the front side of the circulating fan 600 in a detachable manner through a support rod. The circulating fan 600 is arranged on the upper side of the constant pressure closed chamber 100, so that an internal air circulation is formed in the constant pressure closed chamber 100, which facilitates the flow of gas in the circulating mixed environment. The anemometer 610 is used to measure the wind speed in the circulating fan 600.

[0046] In some embodiments of the present invention, the constant pressure closed chamber 100 includes a box body 110 and a movable constant pressure plate 120 arranged on the top of the box body 110. The box body 110 and the movable constant pressure plate 120 form a closed chamber. The collection air bag 300 and the fuel system to be tested are placed in the closed chamber. A pressure sensor is provided in the closed chamber. The pressure sensor is used to measure the air pressure in the constant pressure closed chamber. The movable constant pressure plate 120 can move on the top of the box body 110 to increase or decrease the gas volume in the constant pressure closed chamber 100 by changing the height. Since there will be gas exchange between the carbon canister, the fuel system, the FID detector 400, the collection air bag 300 and the connecting pipeline, and when the temperature changes, the air in the constant pressure sealed chamber 100 will expand or contract. In order to keep the air pressure in the constant pressure sealed chamber 100 constant, the height of the mobile constant pressure plate 120 is adjusted according to the test structure of the pressure sensor to adjust the gas volume in the constant pressure sealed chamber 100, so that the pressure in the constant pressure sealed chamber 100 is maintained at a constant atmospheric pressure value to simulate the atmospheric environment. The mobile constant pressure plate 120 can be moved on the top of the sealed chamber by a slide rail, and the height adjustable function of the mobile constant pressure plate 120 can also be achieved by other sliding mechanisms or connecting mechanisms. In addition, other structures of constant pressure sealed chambers 100 can also be used to keep the pressure in the room constant, which can also achieve the technical effects of the present application.

[0047] Specifically, a closed cavity capacity tester 130 is provided on the outside of the constant pressure closed chamber 100. The closed cavity capacity tester 130 is used to measure the internal space volume of the constant pressure closed chamber 100, that is, the volume in the closed chamber. The closed cavity capacity tester 130 includes a measuring scale 131 and a zero position piece 132. The measuring scale 131 is fixedly connected to the movable constant pressure plate 120. The movable constant pressure plate 120 can be a movable top that is sealed and sleeved on the top of the box body 110 or sealed and embedded in the top of the box body 110. The measuring scale 131 can be fixedly connected to the side wall of the movable constant pressure plate 120 by screw connection. The outer wall of the box body 110 is provided with a zero position piece 132 that matches the measuring scale 131. The zero position piece 132 is fixedly connected to the box body 110. A groove is provided in the middle of the zero position piece 132. A through opening is formed between the groove and the outer wall of the box body 110. The measuring scale 131 passes through the through opening, and the zero position piece 132 is sleeved on the measuring scale 131. A zero line is provided on the zero plate 132 , and a scale line indicating the volume of the sealed chamber is provided on the measuring ruler 131 . The zero line is used to read the reading on the measuring ruler 131 to measure the volume of the sealed chamber at that time.

[0048] More specifically, a drive motor 150 is provided on the outside of the box body 110. The drive motor 150 is connected to the movable constant pressure plate 120 through a screw pair and drives the movable constant pressure plate 120 to move. The screw passes through the movable constant pressure plate 120 and is threadedly connected to the movable constant pressure plate 120. It is one of the preferred structures for driving the movable constant pressure plate 120 to move. The drive motor 150 is a servo motor, which can realize a precise control process.

[0049] In some embodiments of the present invention, a pressure gauge 270 is also connected to the connecting pipe. The pressure gauge 270 is used to measure the air pressure in the connecting pipe and detect whether the air pressure is in a normal state. In this embodiment, two pressure gauges 270 are provided to test the air pressure in the air bag detection pipe and the air bag collection pipe respectively. When the collection air bag 300 is connected to the air bag detection pipe or the air bag collection pipe, the air pressure detected by the two pressure gauges 270 is the air bag pressure in the collection air bag 300. The pressure gauge 270 cooperates with the compressed gas delivery pipe 250. The compressed gas delivery pipe 250 delivers compressed air to the collection air bag 300 that has collected the carbon canister emissions. The pressure gauge 270 detects the pressure in the collection air bag 300 until the gas pressure in the collection air bag 300 reaches the set value, and then the compressed gas delivery pipe 250 is closed and the collection air bag 300 is no longer inflated. After the inflation is completed, the internal air pressure of the collecting air bag 300 is the same. At this time, the gas in the collecting air bag 300 is transported to the FID detector 400 for detection, and the emission concentration is measured to obtain the test result of the carbon canister emission.

[0050] Specifically, the air bag detection tube or the air bag collection tube is connected to a vacuum pump 280, and the vacuum pump 280 is used to extract the gas in the collection air bag 300, so as to facilitate the cleaning of the collection air bag 300 and the next round of air bag collection process.

[0051] In some embodiments of the present invention, a perspective window 140 is provided on the constant pressure sealed chamber 100 , and the perspective window 140 is used to observe the internal situation of the constant pressure sealed chamber 100 .

[0052] In some embodiments of the present invention, the heat exchanger 500 is arranged on the inner wall of the constant pressure closed chamber 100 to exchange heat with the external environment to adjust the temperature in the constant pressure closed chamber 100. A temperature sensor 800 is provided in the constant pressure closed chamber 100, and the temperature sensor 800 is used to measure the temperature in the constant pressure closed chamber 100.

[0053] In some embodiments of the present invention, the on-off valve can be a single-way solenoid valve or a two-position three-way solenoid valve. The solenoid valve can be controlled by a PLC control box 260 to control the connectivity between the constant pressure closed chamber 100, the FID detector 400, the collection air bag 300, the carbon canister and the pipeline gas cleaning component, so as to achieve accurate control and realize an automated detection process.

[0054] Specifically, refer to Figure 3The constant pressure sealed chamber 100 is connected to each other through a pipe box 200. The pipeline box 200 includes an upper pipeline 210 and a lower pipeline 220. Four branch pipes 1 201, 202, 203 and 204 are arranged side by side between the upper pipeline 210 and the lower pipeline 220, and are independently connected to the upper pipeline 210 and the lower pipeline 220. The middle parts of the branch pipes 1 201, 202, 3 203 and 4 204 are respectively connected to the atmospheric pipe 700, the first collecting air bag 310, the second collecting air bag 320 and the compressed gas delivery pipe 250. The branch pipes 1 201, 202, 3 203 and 4 204 are respectively provided with valves 1 211, 212, 3 213 and 4 214 between the branch pipes 1 201, 202, 3 203 and 4 204 and the upper pipeline 210, and valves 5 221, 6 222, 7 223 and 8 224 are respectively provided between the branch pipes 1 201, 202, 3 203 and 4 204 and the lower pipeline 220. The upper pipeline 210 is provided with a branch pipe 5 205 connected to the carbon canister port, a two-position three-way valve 1 230 is provided between the branch pipe 5 205 and the upper pipeline 210, and another connecting port of the two-position three-way valve 1 230 is connected to the inside of the constant pressure sealed chamber 100, the lower pipeline 220 is provided with a branch pipe 6 206 connected to the FID detector 400, the vacuum pump 280 is provided with a branch pipe 8 208 connected to the branch pipe 6 206, and a valve 9 225 is provided on the branch pipe 8 208, and the FID detector 400 is also provided with a branch pipe 7 207 connected to the constant pressure sealed chamber 100, and a two-position three-way valve 240 is provided between the branch pipe 6 206, the branch pipe 7 207 and the FID detector 400. In the specific implementation, it includes the air bag collection process, the air bag detection process, the gas reflux process, the permeation emission detection process and the pipeline cleaning process.

[0055] When the temperature rises, the air bag collection process:

[0056] Reference Figure 4 , the valve 212 is opened, the two-position three-way valve 1 230 controls the carbon canister port to be connected with the upper pipe 210, so that the carbon canister port is connected with the first collecting air bag 310, and the first collecting air bag 310 collects the gas discharged from the carbon canister port; refer to Figure 5 , valve three 213 is opened, and the two-position three-way valve one 230 controls the carbon canister port to be connected with the upper pipeline 210, so that the carbon canister port is connected with the second collecting air bag 320, and the second collecting air bag 320 collects the gas discharged from the carbon canister port.

[0057] Airbag testing process:

[0058] Reference Figure 8 If the exhaust gas has been collected in the first collection gas bag 310, the valve 6 222 is opened, and the two-position three-way valve 2 240 controls the branch pipe 6 206 to be connected with the FID detector 400, so that the first collection gas bag 310 is connected with the FID detector 400, and the collected gas in the first collection gas bag 310 enters the FID detector 400 for detection; refer to Fig. 9If the second collection air bag 320 has collected exhaust gas, the valve 7 223 is opened, and the two-position three-way valve 2 240 controls the branch pipe 6 206 to communicate with the FID detector 400, so that the second collection air bag 320 is connected to the FID detector 400, and the collected gas in the second collection air bag 320 enters the FID detector 400 for detection. The above process is the carbon canister emission detection process.

[0059] Before the gas in the first collection air bag 310 is passed into the FID detector 400, an air bag expansion process is required, see Figure 3 Since the FID detector 400 detects gas concentration, valve two 212, valve four 214 or valve six 222, valve eight 224 are opened to connect the compressed gas delivery pipe 240 with the first collecting air bag 310. The compressed gas delivery pipe 250 delivers compressed air to the first collecting air bag 310. The first collecting air bag 310 expands until the air pressure in the first collecting air bag 310 reaches the set value. The valve is closed so that the first collecting air bag 310 expands to an appropriate size. Similarly, before the gas in the second collecting air bag 320 is introduced into the FID detector 400, an air bag expansion process is required. Open valve three 213, valve four 214 or valve seven 223, valve eight 224 to connect the compressed gas delivery pipe 240 with the second collecting air bag 320. The compressed gas delivery pipe 250 delivers compressed air to the second collecting air bag 320. The second collecting air bag 320 expands until the air pressure in the second collecting air bag 320 reaches the set value. Close the valve so that the second collecting air bag 320 expands to an appropriate size.

[0060] After the FID detector 400 detects the emission concentration, the emission volume is obtained by multiplying it with the volume of the collection air bag 300.

[0061] After the emission detection in the air bag 300 is completed, the gas in the air bag 300 needs to be cleaned:

[0062] Reference Figure 3 , open valve six 222 and valve nine 225, the first collection air bag 310 is connected to the vacuum pump 280, the vacuum pump 280 extracts the gas in the first collection air bag 310 to the outside of the constant pressure closed chamber 100, then open valve two 212, valve four 214 or valve six 222, valve eight 224, and pass compressed air into the first collection air bag 310 to expand the air bag, and then the gas in the first collection air bag 310 is extracted by the vacuum pump 280 after expansion, and this process is repeated several times until the first collection air bag 310 is cleaned. Similarly, the gas in the second collection air bag 320 is cleaned in this way.

[0063] When cooling, the gas reflux process:

[0064] Reference Figure 3 The two-position three-way valve 230 connects the constant pressure sealed chamber 100 with the carbon canister port. Due to the cooling process, the gas in the carbon canister shrinks. In order to protect the constant pressure process in the carbon canister and prevent the exhaust gas collected by the collection air bag 300 from flowing back into the carbon canister, the reflux gas flows back from the constant pressure sealed chamber 100 to the carbon canister.

[0065] Permeate emission testing process:

[0066] Reference Figure 3 When the two-position three-way valve blocks the connection between the branch pipe 6 206 and the FID detector 400, and the FID detector 400 is connected to the constant pressure sealed chamber 100, the FID detector 400 detects the air in the constant pressure sealed chamber 100. Since the fuel vapor infiltrated in the fuel system flows into the constant pressure sealed chamber 100, what is detected in the FID detector 400 at this time is the permeate of the fuel system. The above process is the fuel system permeation emission test process.

[0067] Pipe cleaning process:

[0068] Reference Figure 6 , valve 1 211 and valve 4 214 are opened, compressed gas enters the upper pipeline 210 from the compressed gas delivery pipe 250, cleans the residual gas in the upper pipeline 210, and then flows out from the atmospheric pipe 700, completing the cleaning process of the upper pipeline 210; refer to Figure 7 , valve five 221 and valve eight 224 are opened, and the compressed gas enters the lower pipeline 220 from the compressed gas delivery pipe 250, cleans the residual gas in the lower pipeline 220, and then flows out from the atmospheric pipe 700, completing the cleaning process of the lower pipeline 220.

[0069] It should be noted that the upper pipe 210 is an air bag collection pipe, the lower pipe 220 is an air bag detection pipe, and valves 1 211 to 9 225 are all single-way solenoid valves.

[0070] The above detection process is easy to detect. The whole device collects the carbon canister exhaust gas and the fuel system penetration exhaust gas by simulating environmental changes, and performs a simultaneous detection process on the exhaust gas. The carbon canister and the fuel system are detected under the same temperature and air pressure conditions, which improves the detection accuracy and reduces the test impact on the fuel system and the carbon canister caused by the environment. The test is very convenient.

[0071] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A fuel system detection device, characterized in that: include: A constant pressure closed chamber (100) for accommodating a fuel system; A heat exchanger (500) is arranged on the constant pressure closed chamber (100); A plurality of air collection bags (300) are arranged inside the constant pressure sealed chamber (100), and a carbon canister is respectively connected to each of the air collection bags (300) and the interior of the constant pressure sealed chamber (100); An FID detector (400), the FID detector (400) being respectively connected to each of the collection air bags (300) and the constant pressure closed chamber (100); On-off valves are provided on the connecting pipelines of the constant pressure closed chamber (100), the collecting air bag (300), the carbon canister and the FID detector (400); It also includes an atmospheric pipe (700) and a compressed gas delivery pipe (250), wherein the FID detector (400) is connected to each of the collecting gas bags (300) via an air bag detection pipe, and the atmospheric pipe (700), the air bag detection pipe and the compressed gas delivery pipe (250) are connected in sequence; The compressed gas delivery pipe (250) is connected to an air inlet pipe (208) and a flow meter (252); The carbon canister is connected to each of the collecting air bags (300) via an air bag collecting pipe, and the atmospheric pipe (700), the air bag collecting pipe and the compressed gas delivery pipe (250) are connected in sequence.

2. A fuel system detection device according to claim 1, characterized in that: The constant-pressure sealed chamber (100) comprises a box body (110) and a movable constant-pressure plate (120); the movable constant-pressure plate (120) is arranged on the top of the box body (110) and is capable of moving up and down; the box body (110) and the movable constant-pressure plate (120) form a closed chamber with a variable volume; a pressure sensor is arranged in the closed chamber.

3. A fuel system detection device according to claim 2, characterized in that: A closed cavity capacity tester (130) is provided outside the constant pressure closed chamber (100), and the closed cavity capacity tester (130) comprises a measuring ruler (131) fixedly connected to the movable constant pressure plate (120) and a zero position plate (132) arranged on the outer wall of the box body (110) and covering the measuring ruler (131).

4. A method for detecting a fuel system detection device, using the fuel system detection device as claimed in claim 1, characterized in that: Including the fuel system penetration emission detection process and the carbon canister emission detection process, The fuel system carburization emission detection process includes the following detection steps: The fuel system is placed in a constant pressure sealed chamber (100), the FID detector (400) is connected to the interior of the constant pressure sealed chamber (100), and the gas collected inside the constant pressure sealed chamber (100) is passed into the FID detector (400) for detection; The carbon canister emission detection process includes the following detection steps: a) The heat exchanger (500) controls the temperature inside the constant pressure closed chamber (100) to decrease or increase; b) when the temperature decreases, the carbon canister port is connected to a collecting air bag (300), and the collecting air bag (300) collects the gas discharged from the carbon canister port; when the temperature increases, the carbon canister port is connected to the interior of the constant pressure sealed chamber (100), and the gas in the constant pressure sealed chamber (100) flows back into the carbon canister; c) after collecting the gas discharged from the carbon canister port, the collecting air bag (300) is connected to the FID detector (400) and the gas is passed into the FID detector (400) for detection; The carbon canister emission detection process also includes the following air bag expansion step: the compressed gas delivery pipe (250) delivers compressed air to the collection air bag (300) until the air pressure in the collection air bag (300) reaches a set value.

5. A detection method for a fuel system detection device according to claim 4, characterized in that: The method also includes the following air bag cleaning process: after the FID detector (400) detects the gas in the collection air bag (300), the vacuum pump (280) extracts the gas in the collection air bag (300), and re-introduces compressed air into the collection air bag (300) through the compressed gas delivery pipe (250). After the air bag expands, the compressed air is continuously extracted through the vacuum pump (280), and this process is repeated multiple times.

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