Leakage diagnosis device, leakage diagnosis method, engine system and vehicle

Abstract

The present application provides a leakage diagnosis device, a leakage diagnosis method, an engine system and a vehicle. The leakage diagnosis device includes a housing, and a gas pumping device, a pressure sensor, a partition plate, a blocking portion and a driving portion located inside the housing. The housing is provided with a first through hole communicating with the atmosphere and a second through hole communicating with the device to be diagnosed; the housing is provided with a receiving cavity, a main channel and a reference channel; the receiving cavity communicates with the main channel and the reference channel respectively, and the exhaust volume of the reference channel is less than the maximum allowable leakage amount of the device to be diagnosed. The gas pumping device includes a first air port communicating with the first through hole and a second air port communicating with the receiving cavity. The pressure sensor is fixedly arranged in the receiving cavity. The partition plate and the housing enclose a chamber communicating with the second through hole, the reference channel and the main channel; the partition plate is provided with an opening communicating with the first through hole. In the first state of the driving portion, the opening is opened and the blocking portion blocks the main channel; in the second state of the driving portion, the blocking portion blocks the opening and the main channel is opened.

Description

Technical Field

[0001] The present application relates to the technical field of leakage diagnosis, and particularly relates to a leakage diagnosis device, a leakage diagnosis method, an engine system, and a vehicle. Background Art

[0002] With the improvement of living standards, automobiles have become common means of transportation. When the fuel tank of an automobile leaks, the gasoline in the fuel tank volatilizes into the air, causing air pollution and being unfavorable to environmental protection. Therefore, it is necessary to detect whether the fuel tank has a leakage beyond the allowable range.

[0003] In one solution, the current change of an air pump that pumps air into the fuel tank is used to calculate the fuel tank leakage amount, and then it is determined whether the leakage amount exceeds the allowable range. However, in this solution, the calculated fuel tank leakage amount is affected by voltage fluctuations and the parking slope of the vehicle, which affects the accuracy of the detected fuel tank leakage amount. Summary of the Invention

[0004] The present application provides a leakage diagnosis device, a leakage diagnosis method, an engine system, and a vehicle.

[0005] According to the first aspect of the embodiments of the present application, a leakage diagnosis device is provided. The leakage diagnosis device includes:

[0006] A housing, the housing is provided with a first through hole communicating with the atmosphere and a second through hole for communicating with a device to be diagnosed; the housing is provided with a receiving cavity, a main channel, and a reference channel; the receiving cavity communicates with the main channel and the reference channel respectively, and the exhaust volume of the reference channel is less than the maximum allowable leakage amount of the device to be diagnosed;

[0007] An air pumping device, located inside the housing, the air pumping device includes a first air port and a second air port that are communicated, the first air port communicates with the first through hole, and the second air port communicates with the receiving cavity;

[0008] A pressure sensor, fixedly arranged inside the receiving cavity;

[0009] A partition, located inside the housing, the partition and the housing enclose a chamber, the reference channel and the main channel communicate with the chamber respectively, and the chamber communicates with the second through hole; an opening is provided on the partition, and the first through hole communicates with the chamber through the opening;

[0010] A plugging portion, located inside the chamber;

[0011] The driving part is located inside the housing, and the blocking part is connected to the driving part; the driving part has a first state and a second state. In the first state, the driving part drives the blocking part to move in a direction away from the opening, the opening is opened, and the blocking part blocks the main channel; in the second state, the driving part drives the blocking part to move towards the opening, the blocking part blocks the opening, and the main channel is opened.

[0012] In one embodiment, the driving part includes an electromagnetic coil, a first magnetic part and a second magnetic part; the electromagnetic coil is fixed inside the housing, and the first magnetic part is fixed inside the electromagnetic coil; the second magnetic part is movably located inside the electromagnetic coil and is connected to the blocking part; the first magnetic part and the second magnetic part are magnetic parts that can be magnetized in a magnetic field;

[0013] When the electromagnetic coil is energized, the first magnetic part generates a magnetic suction force on the second magnetic part, driving the second magnetic part to move, and the second magnetic part drives the blocking part to move towards the opening; when the electromagnetic coil is de-energized, the magnetic suction force of the first magnetic part on the second magnetic part disappears, and the second magnetic part drives the blocking part to move, so that the blocking part moves in a direction away from the opening;

[0014] Alternatively, the driving part includes a motor.

[0015] In one embodiment, the main channel is located on a side of the opening away from the first magnetic part, and an end of the second magnetic part away from the first magnetic part penetrates the opening and enters the chamber; the blocking part includes a first blocking piece and a second blocking piece, and the first blocking piece is located on a side of the second blocking piece away from the opening;

[0016] In the first state, the first blocking piece blocks the main channel and the opening is opened; in the second state, the second blocking piece blocks the opening and the main channel is opened.

[0017] In one embodiment, the leakage diagnosis device further includes a first elastic part located in the chamber; the first elastic part is located on a side of the blocking part away from the opening, one end of the first elastic part away from the blocking part is fixed, and the other end abuts against the blocking part.

[0018] In one embodiment, the aperture range of the reference channel is 0.5 mm to 0.8 mm.

[0019] According to a second aspect of the embodiments of the present application, an engine system is provided. The engine system includes an engine, a fuel tank and the above-mentioned leakage diagnosis device, and the fuel tank is communicated with the second through hole.

[0020] According to a third aspect of the embodiments of the present application, a vehicle is provided, including the above-mentioned engine system.

[0021] According to a fourth aspect of the embodiments of the present application, a leakage diagnosis method is provided, which is applied to a controller of a leakage diagnosis device. The leakage diagnosis device includes a housing, and a gas pumping device, a pressure sensor, a partition, a blocking portion and a driving portion located inside the housing. The housing is provided with a first through hole communicating with the atmosphere and a second through hole communicating with a device to be diagnosed; the housing is provided with a receiving cavity, a main channel and a reference channel; the receiving cavity communicates with the main channel and the reference channel respectively, and the exhaust volume of the reference channel is less than the maximum allowable leakage volume of the leakage diagnosis device; the gas pumping device includes a first air port and a second air port which are communicated, the first air port communicates with the first through hole, and the second air port communicates with the receiving cavity; the pressure sensor is fixedly arranged in the receiving cavity; the partition and the housing enclose a chamber, the reference channel and the main channel respectively communicate with the second through hole through the chamber, an opening is provided on the partition, and the first through hole communicates with the chamber through the opening; the blocking portion is connected with the driving portion; the driving portion has a first state and a second state. In the first state, the driving portion drives the blocking portion to move in a direction away from the opening, the opening is opened, and the blocking portion blocks the main channel; in the second state, the driving portion drives the blocking portion to move towards the opening, the blocking portion blocks the opening, and the main channel is opened;

[0022] The leakage diagnosis method includes:

[0023] Controlling the driving portion to be in the first state, and controlling the gas pumping device to be in a working state, so that the gas pumping device pumps gas into the receiving cavity or extracts gas from the receiving cavity;

[0024] When the pressure value detected by the pressure sensor reaches stability, obtaining a first pressure value detected by the pressure sensor;

[0025] Controlling the driving portion to be in the second state, and controlling the gas pumping device to be in the working state;

[0026] When the pressure value detected by the pressure sensor reaches stability, obtaining a second pressure value detected by the pressure sensor;

[0027] Judging whether the leakage volume of the device to be diagnosed is greater than the maximum allowable leakage volume according to the first pressure value and the second pressure value.

[0028] In one embodiment, the working state of the air pumping device is air pumping. The relative pressure corresponding to the first pressure value is the first relative pressure, and the relative pressure corresponding to the second pressure value is the second relative pressure. Judging whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first pressure value and the second pressure value includes:

[0029] If the first relative pressure is greater than the second relative pressure, and the difference between the first relative pressure and the second relative pressure is greater than a first preset threshold, it is determined that the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount;

[0030] Alternatively, the working state of the air pumping device is air extraction. The vacuum degree corresponding to the first pressure value is the first vacuum degree, and the vacuum degree corresponding to the second pressure value is the second vacuum degree. Judging whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first pressure value and the second pressure value includes:

[0031] If the first vacuum degree is greater than the second vacuum degree, and the difference between the first vacuum degree and the second vacuum degree is greater than a second preset threshold, it is determined that the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount.

[0032] In one embodiment, the aperture range of the reference channel is 0.5 mm to 0.8 mm. For example, the aperture of the reference channel is 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, etc.

[0033] The leakage diagnosis device, leakage diagnosis method, engine system and vehicle provided by the embodiments of the present application can determine whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the stable pressure values detected by the pressure sensor when the detection driving part is in the first state and the second state. Since the pressure values detected by the pressure sensor are hardly affected by external factors, the judgment result determined according to the pressure values detected by the pressure sensor is relatively high. All elements of the leakage diagnosis device are integrated in the housing, which helps to arrange the elements compactly and helps to reduce the volume occupied by the leakage diagnosis device. By cooperating the driving part with the air pumping device, it can be judged whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount. The structure of the leakage diagnosis device is simple, which helps to reduce the cost of the leakage diagnosis device. During the leakage diagnosis process, only two state switches of the driving part are required to detect whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount, and the operation is relatively simple and easy to perform.

[0034] It should be understood that the above general description and subsequent detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0036] Figure 1 Schematic diagram of a partial three-dimensional structure of a leakage diagnosis device provided for an exemplary embodiment of the present application;

[0037] Figure 2 Cross-sectional view of the housing of a leakage diagnosis device provided for an exemplary embodiment of the present application;

[0038] Figure 3 Cross-sectional view of a leakage diagnosis device provided for an exemplary embodiment of the present application in one state;

[0039] Figure 4 Cross-sectional view of a leakage diagnosis device provided for an exemplary embodiment of the present application in another state;

[0040] Figure 5 Schematic diagram of the structure of a housing and a pressure sensor provided for an exemplary embodiment of the present application;

[0041] Figure 6 Schematic diagram of the structure of a gas pumping device provided for an exemplary embodiment of the present application;

[0042] Figure 7 Schematic diagram of the structure of a driving part provided for an exemplary embodiment of the present application;

[0043] Figure 8 Flowchart of a leakage diagnosis method provided for an exemplary embodiment of the present application;

[0044] Figure 9 Schematic diagram of the structure of an engine system provided for an exemplary embodiment of the present application. Detailed implementation manners

[0045] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0046] The terms used in the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "the", and "said" used in the present application and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise.

[0047] It should be understood that the terms "first", "second" and similar terms used in the specification and claims of this application do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a quantity limitation, but mean that there is at least one. Unless otherwise specified, terms such as "front part", "rear part", "lower part" and / or "upper part" are only for convenience of description and are not limited to a position or a spatial orientation. The terms "comprising" or "including" and similar terms mean that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalents, and do not exclude other elements or objects.

[0048] The leak diagnosis device, engine system and vehicle according to the embodiments of the present application will be described in detail below with reference to the accompanying drawings. Without conflict, the features in the following embodiments and implementation manners can be supplemented or combined with each other.

[0049] The embodiments of the present application provide a leak diagnosis device. As Figures 1 to 4 shown, the leak diagnosis device includes a housing 10, a gas pumping device 20, a partition 30, a plugging portion 40, a driving portion 50 and a pressure sensor 60.

[0050] The housing 10 is provided with a first through hole 11 communicating with the atmosphere and a second through hole 12 for communicating with the device to be diagnosed. The housing 10 is provided with a receiving cavity 13, a main channel 14 and a reference channel 15; the receiving cavity 13 communicates with the main channel 14 and the reference channel 15 respectively, and the exhaust volume of the reference channel 15 is less than the maximum allowable leakage volume of the device to be diagnosed.

[0051] The gas pumping device 20 is located inside the housing 10. The gas pumping device includes a first air port 21 and a second air port 22 which are communicated. The first air port 21 communicates with the first through hole 11, and the second air port 22 communicates with the receiving cavity 13. The pressure sensor 60 is fixedly arranged in the receiving cavity 13 for detecting the gas pressure in the receiving cavity 13.

[0052] The partition 30 is located inside the housing 10. The partition 30 and the housing 10 enclose a chamber 31. The reference channel 15 and the main channel 14 communicate with the chamber 31 respectively, and the chamber 31 communicates with the second through hole 12. The partition 30 is provided with an opening 32, and the first through hole 11 communicates with the chamber 31 through the opening 32.

[0053] The plugging portion 40 is located within the chamber 31. The driving portion 50 is located within the housing 10, and the plugging portion 40 is connected to the driving portion 50. The driving portion 50 has a first state and a second state. In the first state, the driving portion 50 drives the plugging portion 40 to move in a direction away from the opening 32, the opening 32 is opened, and the plugging portion 40 plugs the main channel 14, as Figure 4 shown. In the second state, the driving portion 50 drives the plugging portion 40 to move toward the opening 32, the plugging portion 40 plugs the opening 32, and the main channel 14 is opened, as Figure 3 shown.

[0054] In the leakage diagnosis device provided by the embodiment of the present application, the second through hole 12 communicates with the device to be diagnosed. When the driving portion 50 is in the first state, the working state of the gas pumping device is gas pumping. The plugging portion 40 plugs the main channel 14, the opening 32 is opened, and the gas pumped into the receiving cavity by the gas pumping device enters the chamber 31 through the reference channel 15 and flows out of the housing 10 through the first through hole 11, or the working state of the gas pumping device is air extraction. The air in the atmosphere enters the chamber 31 through the first through hole 11, then enters the receiving cavity 13 through the reference channel 15, and flows out of the housing through the gas pumping device and the first through hole. When the pressure detected by the pressure sensor reaches stability during this process, it is the first pressure value.

[0055] When the driving portion 50 is in the second state, the working state of the gas pumping device is gas pumping. The plugging portion 40 plugs the opening 32, the main channel 14 is opened, and the gas pumping device pumps gas into the receiving cavity. The gas entering the receiving cavity enters the chamber 31 through the reference channel 15 and the main channel 14, and enters the device to be diagnosed through the second through hole 12, or the working state of the gas pumping device is air extraction. The gas in the device to be diagnosed enters the chamber through the second through hole, then enters the receiving cavity through the reference channel and the main channel, and flows out of the housing through the gas pumping device and the first through hole; when the pressure detected by the pressure sensor reaches stability during this process, it is the second pressure value.

[0056] According to the first pressure value and the second pressure value, it can be determined whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount.

[0057] It can be seen that for the leakage diagnosis device provided in the embodiment of the present application, according to the stable pressure values detected by the pressure sensor when the detection driving part is in the first state and the second state, it can be determined whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount. Since the pressure values detected by the pressure sensor are hardly affected by external factors, the accuracy of the judgment result determined according to the pressure values detected by the pressure sensor is relatively high. All components of the leakage diagnosis device are integrated in the housing, which helps to arrange the components compactly and reduces the volume occupied by the leakage diagnosis device. By cooperating the driving part with the air pumping device, it can be determined whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount. The structure of the leakage diagnosis device is simple, which helps to reduce the cost of the leakage diagnosis device. During the leakage diagnosis process, only by switching the driving part between two states, it can be detected whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount, and the operation is relatively simple and easy to perform.

[0058] It should be noted that when the driving part 50 is in the first state and the second state, the working state of the air pumping device is the same. For example, when the driving part is in the first state and the second state, the air pumping device inflates the receiving cavity; or when the driving part is in the first state and the second state, the air pumping device sucks air from the receiving cavity.

[0059] According to the characteristics of the air pumping device, when the air pumping device pumps air into or extracts air from a cavity, after a period of time, the gas pressure value in the cavity can reach a stable value. If there is no leakage in the cavity, the stable value when the gas pressure value in the cavity reaches stability is a fixed value, and this fixed value is related to the characteristics of the air pumping device. Then, if there is a leakage in the cavity, the stable value when the gas pressure in the cavity reaches stability is different from the stable value when there is no leakage in the cavity. For example, when the air pumping device pumps air into the cavity, the stable value that the gas pressure in the cavity can reach is 7 kPa; if there is a leakage in the cavity, the stable value that the gas pressure in the cavity reaches is less than 7 kPa. For example, when the air pumping device extracts air from the receiving cavity, the stable value that the gas pressure in the cavity can reach is -6 kPa; if there is a leakage in the cavity, the stable value that the gas pressure in the cavity reaches is greater than -6 kPa.

[0060] Taking the working state of the air pumping device as pumping air as an example, the process of using the leakage diagnosis device provided in the embodiment of the present application to determine whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount is as follows:

[0061] When the driving unit 50 is in the first state, the gas pumping device pumps gas into the receiving cavity 13, and the receiving cavity leaks through the reference channel 15. The pressure value when the receiving cavity reaches stability is the first pressure value. When the driving unit 50 is in the second state, the gas pumping device pumps gas into the receiving cavity 13. The gas in the receiving cavity enters the chamber 31 through the reference channel 15 and the main channel 14, and enters the device to be diagnosed through the second through hole 12. The pressure value when the gas pressure in the receiving cavity reaches stability is the second pressure value. At this time, the gas pressure in the receiving cavity is the same as the gas pressure of the device to be diagnosed, and the total leakage amount of the leakage diagnosis device and the device to be diagnosed is the leakage amount of the device to be diagnosed.

[0062] If the first pressure value is less than or equal to the second pressure value, it can be determined that the leakage amount of the device to be diagnosed is less than or equal to the leakage amount of the reference channel. Since the leakage amount of the reference channel is less than the maximum allowable leakage amount of the device to be diagnosed, the leakage amount of the device to be diagnosed is less than the maximum allowable leakage amount. If the first pressure value is greater than the second pressure value, it means that the leakage amount of the device to be diagnosed is greater than the leakage amount of the reference channel. Then, it is judged whether the difference between the second pressure value and the first pressure value is greater than the first preset threshold. If it is greater than the first preset threshold, it is determined that the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount. The first threshold represents the difference between the pressure value when the pressure in the receiving cavity reaches stability when the driving unit is in the second state and the first pressure value when the leakage amount of the device to be diagnosed is the maximum allowable leakage amount.

[0063] In the embodiment of the present application, by setting the exhaust amount (leakage amount) of the reference channel to be less than the maximum allowable leakage amount of the device to be diagnosed, it is helpful to improve the accuracy of leakage diagnosis. Moreover, the device to be diagnosed can be used for different devices to be diagnosed, which can make the application range of the leakage diagnosis device wider.

[0064] Furthermore, in order to improve the accuracy of judging the leakage of the device to be diagnosed and avoid the influence of different atmospheric pressures of the driving unit in the first state and the second state on the accuracy of judging the leakage of the device to be diagnosed, it can be judged whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first relative pressure corresponding to the first pressure value and the second relative pressure corresponding to the second pressure value. In this way, the judgment structure can be more accurate. The first relative pressure corresponding to the first pressure value refers to the value of the relative pressure converted according to the first pressure value, and the second relative pressure corresponding to the second pressure value refers to the value of the relative pressure converted according to the second pressure value.

[0065] In one embodiment, as Figures 3 to 5 shown, the device to be diagnosed further includes a receiving shell 16 fixed in the housing 10, and the cavity in the receiving shell 16 is the receiving cavity 13. The pressure sensor 60 is fixedly arranged in the receiving shell 16.

[0066] In one embodiment, the housing 16 is provided with a first opening 131 and a second opening 132. The first opening 131 communicates with the second air port 22, and the second air port 22 communicates with the accommodation chamber 13 through the first opening 131. The accommodation chamber 13 communicates with the main channel 14 and the reference channel 15 through the second opening 132.

[0067] In one embodiment, a communication channel 17 is further provided in the housing. One end of the communication channel 17 communicates with the accommodation chamber 13, and the other end communicates with the main channel 14 and the reference channel 15 respectively. Specifically, the accommodation chamber 13 communicates with the communication channel 17 through the second opening 132.

[0068] In one embodiment, the flow area of the reference channel 15 is smaller than that of the main channel 14. With such a setting, it can be ensured that the leakage amount of the reference channel 15 is less than the maximum allowable leakage amount of the device to be diagnosed, and it can also be ensured that the flow area of the main channel 14 is larger. Thus, when the driving part is in the second state, the gas flow rate through the main channel 14 is larger, and the air pressure in the device to be diagnosed and the accommodation chamber can reach equilibrium more quickly.

[0069] In one embodiment, the aperture range of the reference channel is 0.5 mm to 0.8 mm. When the device to be diagnosed is the fuel tank of a vehicle, the maximum allowable leakage amount of the fuel tank is equivalent to the leakage amount of a hole with an aperture of 1.0 mm. Setting the aperture range of the reference channel to 0.5 mm to 0.8 mm can ensure that the exhaust gas volume of the reference channel is less than the maximum allowable leakage amount of the device to be diagnosed. At the same time, it can also avoid the aperture of the reference channel being too small, so that the difference between the exhaust gas volume of the reference channel and the maximum allowable leakage amount of the device to be diagnosed is large, and the leakage amount of the reference channel cannot effectively be used as a reference for judging the leakage amount of the device to be diagnosed.

[0070] In one embodiment, as Figure 6 shown, the air pumping device 20 includes a first electrode 203 and a second electrode 204. When the first electrode 203 is connected to the positive pole of the power supply and the second electrode 204 is connected to the negative pole of the power supply, the air pumping device 20 pumps air to the device to be diagnosed; when the first electrode 203 is connected to the negative pole of the power supply and the second electrode 204 is connected to the positive pole of the power supply, the air pumping device 20 sucks air from the device to be diagnosed.

[0071] In one embodiment, as Figure 7As shown, the driving part 50 includes an electromagnetic coil 51, a first magnetic part 52, and a second magnetic part 53. The electromagnetic coil 51 is fixed within the housing 10, and the first magnetic part 52 is fixed within the electromagnetic coil 51. The second magnetic part 53 is movably located within the electromagnetic coil 51 and is connected to the blocking part 40. The first magnetic part 52 and the second magnetic part 53 are magnetic parts that can be magnetized in a magnetic field. When the electromagnetic coil 51 is energized, the first magnetic part 52 generates a magnetic attraction force on the second magnetic part 53, driving the second magnetic part 53 to move. The second magnetic part 53 drives the blocking part 40 to move towards the opening 32. When the electromagnetic coil 51 is de-energized, the magnetic attraction force of the first magnetic part 52 on the second magnetic part 53 disappears, and the second magnetic part 53 drives the blocking part 40 to move, causing the blocking part to move in a direction away from the opening.

[0072] With such a setting, by controlling the energization and de-energization of the electromagnetic coil 51, the switching between the two states of the driving part 50 can be controlled, which is easy to operate.

[0073] In some embodiments, the materials of the first magnetic part 52 and the second magnetic part 53 can be metallic iron.

[0074] In some embodiments, the driving part 50 further includes a second elastic part 54. One end of the second elastic part 54 is connected to the first magnetic part 52, and the other end is connected to the second magnetic part 53. When the electromagnetic coil 51 is energized, the second magnetic part 53 moves towards the first magnetic part 52, and the second elastic part 54 is compressed. When the electromagnetic coil 51 is de-energized, the magnetic attraction force of the first magnetic part 52 on the second magnetic part 53 disappears, the second elastic part 54 expands, and the electromagnetic coil 51 moves in a direction away from the first magnetic part 52. After the electromagnetic coil 51 is de-energized, the second elastic part 54 provides a force for the second magnetic part 53 to move downward, which can avoid the situation where the second magnetic part 53 is stuck and cannot move downward after the electromagnetic coil 51 is de-energized. In some exemplary embodiments, the second elastic part 54 is a spring.

[0075] Furthermore, the blocking part 40 is located within the chamber 31 and below the opening 32. The second magnetic part 53 is located below the first magnetic part 52. The chamber 31 is located below the first magnetic part 52. The lower end of the second magnetic part 53 passes through the opening 32 and enters the chamber 31 and is connected to the blocking part 40. Among them, the flow area of the opening 32 is larger than the cross-section of the part of the second magnetic part 53 passing through the opening 32. There is a gap between the part of the second magnetic part 53 passing through the opening 32 and the wall of the opening 32. When the blocking part 40 does not block the opening 32, gas can pass through the gap between the second magnetic part 53 and the opening 32. The second magnetic part 53 can be rod-shaped.

[0076] In one embodiment, the end of the main channel 14 communicating with the chamber 31 is located on the side of the opening 32 away from the first magnetic member 52, and the end of the second magnetic member 53 away from the first magnetic member 52 penetrates through the opening 32 and enters the chamber 31. The blocking portion 40 includes a first blocking member 41 and a second blocking member 42. Both the first blocking member 41 and the second blocking member 42 are connected to the portion of the second magnetic member 53 located inside the chamber 31. The first blocking member 41 is located on the side of the second blocking member 42 away from the opening 32. In the first state, the first blocking member 41 blocks the main channel 14 and the opening 32 is opened; in the second state, the second blocking member 42 blocks the opening 32 and the main channel 14 is opened.

[0077] In some embodiments, such as Figure 3 and Figure 4 shown, the leakage diagnosis device 100 further includes a first elastic member 70 located inside the chamber 31; the first elastic member 70 is located on the side of the blocking portion 40 away from the opening 32. One end of the first elastic member 70 is fixed, and the other end abuts against the blocking portion 40. One end of the first elastic member 70 can be connected to the inner wall of the housing 10 and thus fixed inside the chamber 31. When the electromagnetic coil 51 is de-energized, the second magnetic member 53 moves in a direction away from the first magnetic member 52. The second magnetic member 53 drives the blocking portion 40 to move downward, and the first elastic member 70 is compressed; when the electromagnetic coil 51 is energized, the second magnetic member 53 moves in a direction close to the first magnetic member 52, and the first elastic member 70 expands, pushing the blocking portion 40 and the second magnetic member 53 to move in a direction close to the first magnetic member 52, which can prevent the situation that the second magnetic member 53 cannot move smoothly in the direction close to the first magnetic member 52, resulting in the blocking portion 40 being unable to block the opening 32. In some exemplary embodiments, the first elastic member 70 is a spring.

[0078] Further, the first elastic member 70 surrounds the opening where the main channel 14 communicates with the chamber 31.

[0079] In another embodiment, the driving portion 50 includes a motor. The motor can drive the blocking portion 40 to move. The motor has two working states. In the first working state, the motor drives the blocking portion 40 to move in a direction away from the opening 32, so that the opening 32 is opened and the blocking portion 40 blocks the main channel 14; in the second state, the motor drives the blocking portion 40 to move in a direction close to the opening 32, so that the blocking portion 40 blocks the opening 32 and the main channel 14 is opened. By controlling the working state of the motor, the opening 32 and the blocking portion can be opened or blocked, which is convenient for operation.

[0080] In one embodiment, the leakage diagnosis device 100 further includes an air filter, and the air filter is disposed at the first through hole. With this arrangement, the air in the atmosphere first passes through the air filter and then enters the air pumping device 20 and the chamber 31. The air filter can filter out impurities in the air, ensuring that there are fewer impurities in the air entering the device to be diagnosed. In some exemplary embodiments, the air filter is a dust filter that can filter out dust in the air.

[0081] In one embodiment, the leakage diagnosis device provided in the present application is provided with a plug-in connector, and both the driving part 50 and the air pumping device 20 are electrically connected to an external power supply through the plug-in connector. In some embodiments, the plug-in connector is provided with a plurality of pins, two of which are electrically connected to the driving part, and the other two pins are electrically connected to the air pumping device.

[0082] In one embodiment, the leakage diagnosis device further includes a controller, and the controller is configured to determine whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first pressure value and the second pressure value.

[0083] An embodiment of the present application further provides a leakage diagnosis method, which is applied to the controller of the leakage diagnosis device, and the leakage diagnosis device is the leakage diagnosis device described in any of the above embodiments. As Figure 8 shown, the leakage diagnosis method includes the following steps 110 to 150.

[0084] In step 110, control the driving part to be in the first state and control the air pumping device to be in the working state, so that the air pumping device pumps air into the receiving chamber or extracts air from the receiving chamber.

[0085] In step 120, when the pressure value detected by the pressure sensor reaches stability, obtain the first pressure value detected by the pressure sensor.

[0086] In step 130, control the driving part to be in the second state and control the air pumping device to be in the working state.

[0087] In step 140, when the pressure value detected by the pressure sensor reaches stability, obtain the second pressure value detected by the pressure sensor.

[0088] In step 150, determine whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first pressure value and the second pressure value.

[0089] It should be noted that in steps 110 and 130, the air pumping device is in the same working state, either in the air pumping working state or in the air extraction working state.

[0090] In some embodiments, step 110 and step 120 may be executed first, step 130 and step 140 may be executed after step 120, and finally step 150 may be executed. In other embodiments, step 130 and step 140 may also be executed first, step 110 and step 120 may be executed after step 140, and finally step 150 may be executed.

[0091] In some embodiments, the working state of the air pumping device is air pumping, the relative pressure corresponding to the first pressure value is the first relative pressure, and the relative pressure corresponding to the second pressure value is the second relative pressure; the step 150 of judging whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first pressure value and the second pressure value includes the following process:

[0092] If the first relative pressure is greater than the second relative pressure, and the difference between the first relative pressure and the second relative pressure is greater than a first preset threshold, it is determined that the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount; if the first relative pressure is greater than the second relative pressure, and the difference between the first relative pressure and the second relative pressure is less than or equal to the first preset threshold, it is determined that the leakage amount of the device to be diagnosed is less than or equal to the maximum allowable leakage amount; if the first relative pressure is less than or equal to the second relative pressure, it is determined that the leakage amount of the device to be diagnosed is less than the maximum allowable leakage amount.

[0093] Wherein, if the first pressure value and the second pressure value detected by the pressure sensor are absolute pressures, before step 150, the leakage diagnosis method further includes: when controlling the driving part to be in the first state, obtaining the first atmospheric pressure of the atmosphere; when controlling the driving part to be in the second state, obtaining the second atmospheric pressure of the atmosphere; determining the first relative pressure corresponding to the first pressure value according to the first pressure value and the first atmospheric pressure, and determining the second relative pressure corresponding to the second pressure value according to the second pressure value and the second atmospheric pressure. The first relative pressure is obtained by subtracting the first atmospheric pressure from the first pressure value, and the second relative pressure is obtained by subtracting the second atmospheric pressure from the second pressure value.

[0094] If the pressure value detected by the pressure sensor is a relative pressure, the first pressure value is the first relative pressure corresponding to it, and the second pressure value is the second relative pressure corresponding to it.

[0095] When the pumping device is in the pumping state, both the first pressure value and the second pressure value are positive. Since the first pressure value and the second pressure value are detected at different time points, the atmospheric pressure at different time points may be different, and the position of the vehicle may change at different time points, and the atmospheric pressure at different positions may also be different. By determining the first relative pressure and the second relative pressure, and judging whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first relative pressure and the second relative pressure, the judgment result is more accurate and the accuracy is higher.

[0096] The first preset threshold characterizes the difference between the relative pressure when the pressure in the receiving cavity reaches stability in the second state of the driving part and the first relative pressure when the leakage amount of the device to be diagnosed is the maximum allowable leakage amount when the pumping device is in the pumping state. It should be noted that the first preset threshold may be equal to this difference or may differ from this difference within a small range.

[0097] When the pumping device is in the pumping state, when the driving part is in the first state, the leakage amount of the leakage diagnosis device is the leakage amount of the reference channel; when the driving part is in the second state, the total leakage amount of the leakage diagnosis device and the device to be diagnosed is the leakage amount of the device to be diagnosed. Whether the driving part is in the first state or the second state, the greater the leakage amount, the smaller the pressure value when the pressure in the receiving cavity reaches stability, and the smaller the relative pressure of the receiving cavity.

[0098] When the first relative pressure is less than or equal to the second relative pressure, it indicates that the leakage amount of the device to be diagnosed is less than or equal to the leakage amount of the reference channel. Since the leakage amount of the reference channel is less than the maximum allowable leakage amount, the leakage amount of the device to be diagnosed is less than the maximum allowable leakage amount. When the first relative pressure is greater than the second relative pressure, it indicates that the leakage amount of the device to be diagnosed is greater than the leakage amount of the reference channel, and it is necessary to continue to judge whether the difference between the first relative pressure and the second relative pressure is greater than the first preset threshold. When the difference between the first relative pressure and the second relative pressure is greater than the first preset threshold, it indicates that the difference between the leakage amount of the device to be diagnosed and the leakage amount of the reference channel is greater than the difference between the maximum allowable leakage amount and the leakage amount of the reference channel, that is, the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount.

[0099] In another embodiment, the working state of the pumping device is air extraction, the vacuum degree corresponding to the first pressure value is the first vacuum degree, and the vacuum degree corresponding to the second pressure value is the second vacuum degree; the step 150 of judging whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first pressure value and the second pressure value includes the following process:

[0100] If the first vacuum degree is less than or equal to the second vacuum degree, it is determined that the leakage amount of the device to be diagnosed is less than the maximum allowable leakage amount; if the first vacuum degree is greater than the second vacuum degree and the difference between the first vacuum degree and the second vacuum degree is greater than the second preset threshold, it is determined that the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount; if the first vacuum degree is less than the second vacuum degree and the difference between the first vacuum degree and the second vacuum degree is less than or equal to the second preset threshold, it is determined that the leakage amount of the device to be diagnosed is less than or equal to the maximum allowable leakage amount.

[0101] Wherein, if the first pressure value and the second pressure value detected by the pressure sensor are absolute pressures, before step 150, the leakage diagnosis method further includes: when controlling the driving part to be in the first state, acquiring the first atmospheric pressure of the atmosphere; when controlling the driving part to be in the second state, acquiring the second atmospheric pressure of the atmosphere; determining the first vacuum degree corresponding to the first pressure value according to the first pressure value and the first atmospheric pressure, and determining the vacuum degree corresponding to the second pressure value according to the second pressure value and the second atmospheric pressure. The first vacuum degree is obtained by subtracting the first pressure value from the first atmospheric pressure, and the second vacuum degree is obtained by subtracting the second pressure value from the second atmospheric pressure.

[0102] If the pressure sensor is a vacuum gauge and the pressure value detected by it is a vacuum degree, the first pressure value is the first vacuum degree corresponding to it, and the second pressure value is the second vacuum degree corresponding to it.

[0103] When the air pumping device is in the air pumping state, both the first pressure value and the second pressure value are negative numbers. Since the first pressure value and the second pressure value are detected at different times, the atmospheric pressure may be different at different time points, and the position of the vehicle may change, and the atmospheric pressure at different positions may also be different. By detecting the first atmospheric pressure and the second atmospheric pressure to determine the first vacuum degree and the second vacuum degree, and judging whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first vacuum degree and the second vacuum degree, the judgment result is more accurate and the accuracy is higher.

[0104] The second preset threshold characterizes the difference between the vacuum degree when the pressure in the accommodation cavity reaches stability in the second state of the driving part and the first vacuum degree when the leakage amount of the device to be diagnosed is the maximum allowable leakage amount in the air pumping state of the air pumping device. It should be noted that the second preset threshold may be equal to this difference or may differ from this difference within a small range.

[0105] When the pump gas device is in the air extraction state, when the driving part is in the first state, the leakage amount of the leakage diagnosis device is the leakage amount of the reference channel; when the driving part is in the second state, the total leakage amount of the leakage diagnosis device and the device to be diagnosed is the leakage amount of the device to be diagnosed. Whether the driving part is in the first state or the second state, the greater the leakage amount, the greater the pressure value when the pressure in the accommodation cavity reaches stability, and the smaller the vacuum degree of the accommodation cavity.

[0106] When the first vacuum degree is less than or equal to the second vacuum degree, it indicates that the leakage amount of the device to be diagnosed is less than or equal to the leakage amount of the reference channel. Since the leakage amount of the reference channel is less than the maximum allowable leakage amount, the leakage amount of the device to be diagnosed is less than the maximum allowable leakage amount. When the first vacuum degree is greater than the second vacuum degree, it indicates that the leakage amount of the device to be diagnosed is greater than the leakage amount of the reference channel, and it is necessary to continue to judge whether the difference between the first vacuum degree and the second vacuum degree is greater than the second preset threshold. If the difference between the first vacuum degree and the second vacuum degree is greater than the second preset threshold, it indicates that the difference between the leakage amount of the device to be diagnosed and the leakage amount of the reference channel is greater than the difference between the maximum allowable leakage amount and the leakage amount of the reference channel, that is, the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount.

[0107] In one embodiment, the aperture range of the reference channel is 0.5 mm to 0.8 mm.

[0108] The embodiment of the present application also provides an engine system. Refer to Figure 9 , the engine system includes an engine 84, a fuel tank 81 and the leakage diagnosis device 100 described in any of the above embodiments. The fuel tank 81 is communicated with the second through hole of the housing, and the fuel tank 81 is communicated with the intake manifold of the engine 84.

[0109] When diagnosing whether the leakage amount of the fuel tank is greater than the maximum allowable leakage amount in the engine system provided by the embodiment of the present application, first control the driving part 50 to be in the first state, the pump gas device 20 pumps gas into or sucks gas from the accommodation cavity, and when the pressure value detected by the pressure sensor reaches stability, obtain the first pressure value detected by the pressure sensor; then, control the driving part 50 to be in the second state, the pump gas device 20 pumps gas into or sucks gas from the accommodation cavity, and when the pressure value detected by the pressure sensor reaches stability, obtain the second pressure value detected by the pressure sensor; judge whether the leakage amount of the fuel tank is greater than the maximum allowable leakage amount according to the first pressure value and the second pressure value.

[0110] In one embodiment, the fuel tank 81 is directly communicated with the intake manifold of the engine 84. The engine system further includes a check valve 86 connected between the fuel tank 81 and the engine 84. The inlet of the check valve 86 is communicated with the fuel tank 81, and the outlet of the check valve 86 is communicated with the intake manifold of the engine 84. The fuel vapor in the fuel tank 81 can enter the engine 84 through the check valve 86. The check valve 86 is provided to prevent the fuel vapor from flowing back into the fuel tank 81.

[0111] In one embodiment, the engine system further includes a carbon canister 82, and the carbon canister 82 is connected between the second through hole of the housing and the fuel tank 81. The fuel tank 81 is communicated with the second through hole through the carbon canister 82. By providing the carbon canister 82, when the engine is turned off, the gasoline vapor in the fuel tank 81 enters the carbon canister 82, and the activated carbon in the carbon canister 82 adsorbs the fuel vapor. In this way, the gasoline vapor can be prevented from entering the atmosphere, achieving the purpose of saving fuel and environmental protection. When the engine is started, the fuel vapor stored in the carbon canister 82 enters the intake manifold of the engine.

[0112] In one embodiment, refer to Figure 3 , the engine system further includes a canister purge valve 87, and the canister purge valve 87 is connected between the carbon canister 82 and the intake manifold of the engine 84. When the engine 84 is started, the canister purge valve 87 connects the carbon canister 82 and the engine 84, and the gas in the carbon canister 82 enters the engine 84 through the canister purge valve 87; when performing a leak diagnosis, the canister purge valve 87 is closed, the engine 84 is not communicated with the carbon canister 82, and the leak diagnosis device 100 detects whether the leakage amount of the fuel tank 81 is greater than the maximum allowable leakage amount.

[0113] In one embodiment, the engine system further includes a throttle valve 88. The inlet of the throttle valve 88 is communicated with the atmosphere, and the outlet is communicated with the intake manifold of the engine. The throttle valve 88 can control the amount of air entering the engine 84.

[0114] In one embodiment, the engine system further includes an exhaust system 85. The exhaust system 85 is used to discharge the exhaust gas discharged during the operation of the engine 84, and can reduce the pollution of the discharged exhaust gas and the exhaust noise.

[0115] An embodiment of the present application further provides a vehicle, including the engine system described in the above embodiment.

[0116] The above are only the preferred embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application has been disclosed above with the preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the above-disclosed technical content within the scope of the technical solution of the present application. However, as long as it does not depart from the content of the technical solution of the present application, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application still fall within the scope of the technical solution of the present application.

[0117] The content disclosed in this patent document contains copyrighted material. The copyright belongs to the copyright owner. The copyright owner does not object to anyone copying this patent document or the patent disclosure as it exists in the official records and files of the Patent and Trademark Office.

Claims

1. A leakage diagnosis device, characterized in that, The leak diagnosis device includes: A housing (10) provided with a first through hole (11) communicating with the atmosphere and a second through hole (12) for communicating with the device to be diagnosed; the housing is provided with a receiving housing (16) having a receiving cavity (13) therein, and the housing further has a main channel (14), a reference channel (15) and a communication channel (17); the receiving cavity communicates with the main channel and the reference channel respectively through the communication channel, and the exhaust volume of the reference channel is less than the maximum allowable leakage volume of the device to be diagnosed; A gas pumping device (20) located within the housing (10), the gas pumping device including a first gas port (21) and a second gas port (22) in communication, the first gas port communicating with the first through hole, and the second gas port communicating with the receiving cavity; A pressure sensor (60) fixedly disposed within the receiving cavity; A partition (30) located within the housing, the partition (30) and the housing enclosing a chamber (31), the reference channel and the main channel communicating with the chamber (31) respectively, and the chamber communicating with the second through hole; an opening (32) is provided on the partition (30), and the first through hole communicates with the chamber through the opening; A blocking portion (40) located within the chamber; A driving portion (50) located within the housing, the blocking portion being connected to the driving portion; the driving portion has a first state and a second state. In the first state, the driving portion drives the blocking portion to move in a direction away from the opening, the opening is opened, and the blocking portion blocks the main channel; in the second state, the driving portion drives the blocking portion to move towards the opening, the blocking portion blocks the opening, and the main channel is opened.

2. The leak diagnosis device according to claim 1, characterized in that, The driving portion (50) includes an electromagnetic coil (51), a first magnetic member (52) and a second magnetic member (53); the electromagnetic coil is fixed within the housing, the first magnetic member is fixed within the electromagnetic coil; the second magnetic member is movably located within the electromagnetic coil and is connected to the blocking portion; the first magnetic member and the second magnetic member are magnetic members that can be magnetized in a magnetic field; When the electromagnetic coil is energized, the first magnetic member generates a magnetic attraction force on the second magnetic member, driving the second magnetic member to move, and the second magnetic member drives the blocking portion to move towards the opening; when the electromagnetic coil is de-energized, the magnetic attraction force of the first magnetic member on the second magnetic member disappears, and the second magnetic member drives the blocking portion to move, causing the blocking portion to move in a direction away from the opening; Alternatively, the driving portion includes a motor.

3. The leak diagnosis device according to claim 2, wherein The main channel is located on a side of the opening away from the first magnetic member, and an end of the second magnetic member (53) away from the first magnetic member passes through the opening (32) and enters the chamber; the blocking portion includes a first blocking member and a second blocking member, and the first blocking member is located on a side of the second blocking member away from the opening; In the first state, the first blocking member blocks the main channel and the opening is opened; In the second state, the second plugging member plugs the opening, and the main channel is opened.

4. The leakage diagnosis device according to claim 2, characterized in that, The leakage diagnosis device further includes a first elastic member (70) located in the chamber (31); the first elastic member is located on a side of the plugging portion away from the opening, one end of the first elastic member away from the plugging portion is fixed, and the other end abuts against the plugging portion.

5. The leakage diagnosis device according to claim 1, characterized in that, The aperture range of the reference channel is 0.5 mm to 0.8 mm.

6. An engine system, characterized in that, The engine system includes an engine, a fuel tank, and the leakage diagnosis device according to any one of claims 1 to 5, and the fuel tank is communicated with the second through hole.

7. A vehicle, characterized in that, An engine system including the engine system according to claim 6.

8. A leakage diagnosis method, applied to a controller of a leakage diagnosis device, characterized in that, The leakage diagnosis device further includes a housing, and a gas pumping device, a pressure sensor, a partition, a plugging portion, and a driving portion located in the housing. The housing is provided with a first through hole communicated with the atmosphere and a second through hole communicated with the device to be diagnosed; the housing is provided with a receiving cavity, a main channel, and a reference channel; the receiving cavity is communicated with the main channel and the reference channel respectively, and the exhaust volume of the reference channel is less than the maximum allowable leakage volume of the leakage diagnosis device; the gas pumping device includes a first gas port and a second gas port communicated with each other, the first gas port is communicated with the first through hole, and the second gas port is communicated with the receiving cavity; the pressure sensor is fixedly arranged in the receiving cavity; the partition and the housing enclose to form a chamber, the reference channel and the main channel are respectively communicated with the second through hole through the chamber, an opening is provided on the partition, and the first through hole is communicated with the chamber through the opening; the plugging portion is connected with the driving portion; the driving portion has a first state and a second state. In the first state, the driving portion drives the plugging portion to move in a direction away from the opening, the opening is opened, and the plugging portion plugs the main channel; In the second state, the driving portion drives the plugging portion to move towards the opening, the plugging portion plugs the opening, and the main channel is opened; The leakage diagnosis method includes: Controlling the driving portion to be in the first state, and controlling the gas pumping device to be in a working state, so that the gas pumping device pumps gas into the receiving cavity or extracts gas from the receiving cavity; When the pressure value detected by the pressure sensor reaches stability, obtaining a first pressure value detected by the pressure sensor; Controlling the driving portion to be in the second state, and controlling the gas pumping device to be in the working state; When the pressure value detected by the pressure sensor reaches stability, obtaining a second pressure value detected by the pressure sensor; Judging whether the leakage volume of the device to be diagnosed is greater than the maximum allowable leakage volume according to the first pressure value and the second pressure value.

9. The leak diagnosis method according to claim 8, wherein The working state of the gas pumping device is pumping gas. The relative pressure corresponding to the first pressure value is the first relative pressure, and the relative pressure corresponding to the second pressure value is the second relative pressure. Judging whether the leakage volume of the device to be diagnosed is greater than the maximum allowable leakage volume according to the first pressure value and the second pressure value includes: If the first relative pressure is greater than the second relative pressure, and the difference between the first relative pressure and the second relative pressure is greater than a first preset threshold, it is determined that the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount; Alternatively, the operating state of the air pumping device is air extraction, the degree of vacuum corresponding to the first pressure value is the first degree of vacuum, and the degree of vacuum corresponding to the second pressure value is the second degree of vacuum; judging whether the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount according to the first pressure value and the second pressure value includes: If the first degree of vacuum is greater than the second degree of vacuum, and the difference between the first degree of vacuum and the second degree of vacuum is greater than a second preset threshold, it is determined that the leakage amount of the device to be diagnosed is greater than the maximum allowable leakage amount.

10. The leakage diagnosis method according to claim 8, wherein, The aperture range of the reference channel is 0.5 mm to 0.8 mm.

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