Oil tank leakage diagnosis module and self-cleaning method thereof

Abstract

The invention provides an oil tank leakage diagnosis module and a self-cleaning method thereof, and relates to the technical field of oil tank leakage diagnosis equipment, the oil tank leakage diagnosis module comprises a shell, an air inlet pipe, a filtering assembly, an air path switching unit and an opening and closing control unit, the shell is provided with a control cavity, an air pump cavity, a first connector and a second connector, the first connector communicates with the control cavity, and the second connector communicates with the air pump cavity; and the second interface is communicated with the air pump cavity. By arranging the gas path switching unit and the opening and closing control unit, the gas path is changed, so that during cleaning operation, gas in the gas pump cavity flows towards the gas inlet pipe, particle impurities on the filtering assembly are blown away, meanwhile, reciprocating blowing is achieved in cooperation with a gas inlet loop of the gas inlet pipe under the normal condition, and the cleaning efficiency is improved. Therefore, the self-cleaning operation of the filter assembly is realized, and the situation that the oil tank leakage diagnosis module cannot work normally due to the blockage of the filter assembly is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel tank leakage diagnosis equipment, and particularly to a fuel tank leakage diagnosis module and a self-cleaning method thereof. Background Art

[0002] Due to the requirements of the national VI emission standards, many vehicles have added a functional component for identifying leaks in the fuel tank, fuel vapor pipeline to the canister solenoid valve system on the basis of the original fuel vapor recovery system EVAP components in the past: the fuel leakage diagnosis module. The working principle of the module is based on the changes in pressure and temperature. After the engine is turned off, the fuel leakage diagnosis module will control the operation of the diagnosis pump through the engine controller to pump air into the system. If the pressure can reach above the set pressure within the specified time, it is judged as qualified; otherwise, it is judged that there is a leak. In addition, in order to prevent particles in the atmosphere from entering the canister and causing the canister to be blocked, a gray filter needs to be set in the system, which is usually connected to the intake end of the diagnosis pump to filter out particles in the atmosphere.

[0003] In the prior art, the fuel leakage diagnosis module is respectively connected to the gray filter and the canister. The gray filter and the diagnosis module are connected by a pipeline of a certain length. If the vehicle often or travels for a long time in an environment with serious dust pollution, it is very easy to cause the gray filter to be blocked, thus affecting the normal operation of the fuel leakage diagnosis module. Summary of the Invention

[0004] In view of this, the present invention provides a fuel tank leakage diagnosis module and a self-cleaning method thereof. By setting an air path switching unit and an opening and closing control unit, the diversion of the air path is realized. Thus, during the cleaning operation, the gas in the air pump cavity flows towards the intake pipe to blow off the particulate impurities on the filter assembly. At the same time, in cooperation with the intake air circuit of the intake pipe under normal conditions, reciprocating purging is realized, so that the particulate impurities adhering to the filter assembly fall off and leave the filter assembly, thereby realizing the self-cleaning operation of the filter assembly to prevent the fuel tank leakage diagnosis module from failing to work properly due to the blockage of the filter assembly.

[0005] The technical solution of the present invention is realized as follows:

[0006] On the one hand, the present invention provides a fuel tank leakage diagnosis module, including a housing, an intake pipe, a filter assembly, an air path switching unit and an opening and closing control unit, wherein,

[0007] A control cavity, an air pump cavity, a first interface and a second interface are provided on the housing. The first interface communicates with the control cavity, and the second interface communicates with the air pump cavity;

[0008] The intake pipe is fixed on the housing. A third interface is provided on the intake pipe. A connecting pipe extending into the intake pipe is provided on the housing. The air pump cavity is communicated with the intake pipe through the connecting pipe;

[0009] The filtering component is arranged on the intake pipe, and the filtering component is used to filter particulate impurities in the atmosphere;

[0010] The gas path switching unit connects the first interface, the second interface and the third interface, and makes the second interface connect to one of the first interface and the third interface;

[0011] The opening and closing control unit is arranged on the intake pipe and has a blocking end, and the blocking end is used to block the connecting pipe;

[0012] When the second interface is connected to the third interface, the opening and closing control unit blocks the connecting pipe, and the gas in the air pump cavity enters the intake pipe through the gas path switching unit and flows towards the atmosphere to clean the particulate impurities attached to the filtering component.

[0013] On the basis of the above technical solutions, preferably, the filtering component includes an end cover, a housing and a filter element, wherein,

[0014] The end cover is fixed at the end of the intake pipe;

[0015] The housing is fixed inside the end cover and forms a gap with the end cover. The intake pipe is inserted into this gap. The housing blocks the end of the intake pipe, and air holes are provided on the housing;

[0016] The filter element is arranged inside the housing, so that the atmosphere can enter the housing through the air holes and the filter element.

[0017] Further preferably, the housing includes a fixed housing, a detachable housing and a sealing ring, wherein,

[0018] The fixed housing is fixed on the end cover and is provided with an opening on the side away from the end cover. The filter element is inserted into the fixed housing;

[0019] The detachable housing is inserted into the fixed housing from the opening side of the fixed housing and is relatively fixed to the fixed housing. The fixed housing and the detachable housing cooperate to form a receiving cavity, and the filter element is arranged in the receiving cavity;

[0020] The sealing ring is arranged at the connection between the fixed housing and the detachable housing.

[0021] On the basis of the above technical solutions, preferably, the gas path switching unit includes a gas path block, a piston rod and a driving member, wherein,

[0022] The gas path block is fixed on the housing. The gas path block is provided with a first gas path, a second gas path and a third gas path. The first gas path connects to the first interface, the second gas path connects to the second interface, and the third gas path connects to the third interface;

[0023] The piston rod is arranged inside the gas path block and extends into the first gas path, the second gas path and the third gas path. The piston rod is used to disconnect one of the first gas path and the third gas path and connect the second gas path to the other;

[0024] The driving member is arranged inside the air circuit block and is in transmission connection with the piston rod. The driving member is used to push the piston rod to move.

[0025] Further preferably, the air circuit block further includes a sealing ring. A plurality of insertion ports are provided on the air circuit block. The sealing rings are respectively arranged in each insertion port. The first interface and the second interface are respectively inserted into an insertion port and are in contact with the sealing rings in the insertion ports.

[0026] Based on the above technical solutions, preferably, the opening and closing control unit includes a base, a movable rod and a blocking ball. Among them,

[0027] The base is fixed inside the intake pipe;

[0028] The movable rod is movably arranged on the base and can move towards the connecting pipe;

[0029] The blocking ball is fixed at the end of the movable rod and can be inserted into the opening side of the connecting pipe. The diameter of the blocking ball is larger than the inner diameter of the connecting pipe.

[0030] Based on the above technical solutions, preferably, it further includes a vibrating member. The vibrating member is arranged on the intake pipe. The vibrating member is used to drive the filter assembly to vibrate

[0031] On the other hand, the present invention provides a self-cleaning method for a fuel tank leakage diagnosis module, which is used for the above fuel tank leakage diagnosis module to clean the particulate impurities attached to the filter assembly. The self-cleaning method for the fuel tank leakage diagnosis module includes the following steps:

[0032] S1 Obtain real-time monitoring data;

[0033] S2 According to the real-time monitoring data, judge whether to perform a self-cleaning operation. If a self-cleaning operation is required, proceed to the next step. If a self-cleaning operation is not required, return to step S1;

[0034] S3 Switch the fuel tank leakage diagnosis module back and forth between the normal mode and the cleaning mode for a certain period of time. In the normal mode, the first interface is communicated with the second interface, and the opening and closing control unit does not block the connecting pipe. In the cleaning mode, the air circuit switching unit makes the second interface communicate with the third interface, and the opening and closing control unit blocks the connecting pipe;

[0035] S4 Record the number of self-cleaning operations within a certain period of time. If it exceeds a certain number, issue a warning. If it does not exceed a certain number, return to step S1.

[0036] Based on the above technical solutions, preferably, the real-time monitoring data includes the real-time current of the diagnostic pump.

[0037] Further preferably, before step S1, a current threshold is set. In step S2, when the real-time current reaches the current threshold, a self-cleaning operation is performed.

[0038] The fuel tank leakage diagnosis module and its self-cleaning method of the present invention have the following beneficial effects compared with the prior art:

[0039] (1) By setting an air path switching unit and an opening and closing control unit, the diversion of the air path is realized. Thus, during the cleaning operation, the gas in the air pump cavity flows towards the intake pipe to blow off the particulate impurities on the filter assembly. At the same time, in cooperation with the intake air circuit of the intake pipe under normal conditions, reciprocating purging is realized, so that the particulate impurities adhered to the filter assembly fall off and leave the filter assembly, thereby realizing the self-cleaning operation of the filter assembly to avoid the abnormal operation of the fuel tank leakage diagnosis module caused by the blockage of the filter assembly.

[0040] (2) Through the setting of the fixed shell and the detachable shell, it is convenient to carry out the assembly operation of the filter element. At the same time, in the later stage, when the filter element cannot be effectively cleaned through the cleaning mode, the detachable shell can be opened to take out the filter element from the fixed shell for replacement. This setting is also more convenient for assembly.

[0041] (3) By setting a vibrating member, the vibrating member is arranged on the intake pipe. The vibrating member is used to drive the filter assembly to vibrate. The vibrating member can be a vibrating motor, which is connected to the intake pipe by a fixed seat. During the self-cleaning operation, a vibration force is generated to cooperate with the reciprocating purging to form a vibration cleaning, thereby improving the cleaning efficiency and cleaning effect of the filter element. Description of the Drawings

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0043] Figure 1 It is a three-dimensional view of the fuel tank leakage diagnosis module of the present invention;

[0044] Figure 2 It is a schematic diagram of the removal of the air path switching unit of the fuel tank leakage diagnosis module of the present invention;

[0045] Figure 3 It is a side view of the fuel tank leakage diagnosis module of the present invention;

[0046] Figure 4 is Figure 3 a cross-sectional view taken along line A-A in

[0047] Figure 5 Schematic diagram of the gas path switching unit of the fuel tank leakage diagnosis module of the present invention;

[0048] Figure 6 Another perspective side view of the fuel tank leakage diagnosis module of the present invention;

[0049] Figure 7 is Figure 6 Cross-sectional view taken along line B-B in

[0050] Figure 8 Schematic diagram of the structure of the filter assembly of the fuel tank leakage diagnosis module of the present invention. Detailed implementation manners

[0051] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0052] As Figure 1-8 shown, the fuel tank leakage diagnosis module of the present invention includes a housing 1, an intake pipe 2, a filter assembly 3, a gas path switching unit 4, and an opening and closing control unit 5.

[0053] A control chamber 101, a gas pump chamber 102, a first interface 103, and a second interface 104 are provided on the housing 1. The first interface 103 communicates with the control chamber 101, and the second interface 104 communicates with the gas pump chamber 102. The housing 1 is a plastic part and is integrally formed by injection molding. The provided control chamber 101 is used to install an electromagnetic valve, and the provided gas pump chamber 102 is used to install a diagnostic pump. The control chamber 101 communicates with the gas pump chamber 102. The first interface 103 is the intake end of the control chamber 101, and the second interface 104 is the outlet end of the control chamber 101. Correspondingly, other interfaces such as an outlet pipe are also provided on the housing 1. Interfaces not described in detail are the same as those in the prior art and will not be described separately here.

[0054] The intake pipe 2 is fixed on the housing 1. A third interface 201 is provided on the intake pipe 2. A connecting pipe 11 extending into the intake pipe 2 is provided on the housing 1. The gas pump chamber 102 communicates with the intake pipe 2 through the connecting pipe 11. A connection port is also opened on the housing 1, which is used to communicate the control chamber 101 with the intake pipe 2, and the electromagnetic valve in the control chamber 101 can control the opening and closing of the connection port.

[0055] The filtering component 3 is arranged on the air inlet pipe 2. The filtering component 3 is used to filter particulate impurities in the atmosphere. Compared with the prior art where a long pipe is used to connect the ash filter, in this embodiment, in order to save installation space and realize its self-cleaning function, the filtering component 3 is integrally integrated onto the air inlet pipe 2.

[0056] The air path switching unit 4 connects the first interface 103, the second interface 104 and the third interface 201, and makes the second interface 104 connect to one of the first interface 103 and the third interface 201. When the air path switching unit 4 is used to change the working mode of the fuel tank leakage diagnosis module, it switches the connection state between the second interface 104 and the first interface 103 and the third interface 201. The working modes of the fuel tank leakage diagnosis module include the normal mode and the cleaning mode. In the normal mode, the fuel tank leakage diagnosis module works normally. At this time, the first interface 103 is connected to the second interface 104. In the cleaning mode, the first interface 103 is closed and the connection with the second interface 104 is disconnected, and the second interface 104 is connected to the third interface 201.

[0057] The opening and closing control unit 5 is arranged on the air inlet pipe 2 and has a blocking end. The blocking end is used to block the connecting pipe 11. In the normal mode, the air inlet pipe 2 is connected to the connecting pipe 11, and then air is sent into the air pump chamber 102. In the cleaning mode, the air inlet pipe 2 and the connecting pipe 11 are disconnected by the opening and closing control unit 5.

[0058] When the second interface 104 is connected to the third interface 201, the opening and closing control unit 5 blocks the connecting pipe 11. The gas in the air pump chamber 102 enters the air inlet pipe 2 through the air path switching unit 4 and flows towards the atmosphere to clean the particulate impurities attached to the filtering component 3.

[0059] In the cleaning mode, the air inlet pipe 2 is disconnected from the control chamber 101 and the air pump chamber 102. The connection and disconnection between the air inlet pipe 2 and the control chamber 101 are controlled by an electromagnetic valve in the control chamber 101, so that the gas in the control chamber 101 and the air pump chamber 102 can only be discharged through the second interface 104. When the diagnostic pump rotates, due to inertia and still being in a rotating state, the gas in the control chamber 101 and the air pump chamber 102 can be sent into the air inlet pipe 2 in a relatively short time, forming a negative pressure in the control chamber 101 and the air pump chamber 102. The gas entering the air inlet pipe 2 will impact the filtering component 3, and the floating particulate impurities on it will enter the external atmosphere.

[0060] The back-and-forth switching between the cleaning mode and the normal mode can make the particulate impurities on the filtering component 3 gradually detach from the filtering component 3 under the continuous one-in-one-out change of air and be blown into the external atmosphere, thus forming self-cleaning.

[0061] In some embodiments, the filtering component 3 includes an end cap 31, a housing 32 and a filter element 33. The end cap 31 is fixed to the end of the intake pipe 2. The housing 32 is fixed within the end cap 31 and forms a gap therebetween. The intake pipe 2 is inserted into this gap. The housing 32 blocks the end of the intake pipe 2. The housing 32 is provided with air holes. The filter element 33 is disposed within the housing 32 such that the atmosphere can enter the outer shell 1 through the air holes and the filter element 33.

[0062] Since the intake end of the outer shell 1 usually uses a circular pipe, correspondingly, in order to maximize the use of materials, the entire end cap 31 is set to be circular, and its thickness can be set between 3 - 7 mm. The entire end cap 31 is made of plastic material, and its radius needs to be greater than the radius of the intake pipe 2 so as to completely block the opening side of the intake pipe 2. The number of air holes can be selected according to different usage scenarios or design conditions. If multiple air holes are provided, they can be arranged in an array. In some other embodiments, the air hole can be set to one or in a mesh setting, etc.

[0063] The filter element 33 is disposed within the housing 32 and fits against the inner wall of the housing 32. The filter element 33 is used to block the dust entering the outer shell 1 through the air holes. In some embodiments, the filter element 33 can be arranged in the form of a filler within the housing 32 or can be made by shaping a porous material. After the filter element 33 is installed in the housing 32, a gap between the filter element 33 and the inner wall of the housing 32 needs to be avoided to prevent air from entering the outer shell through the gap. Additionally, if a porous material is selected to shape and make the filter element 33, the outer diameter of the filter element 33 needs to be greater than the inner diameter of the housing 32, so that the filter element 33 is inserted into the housing 32 through deformation for fixation. Specifically, the filter element 33 can be selected as a sponge column, which is placed in the housing 32 through deformation. The porous structure of the sponge can be used to filter the air and achieve the removal of particles. Compared with the filler form, it is easier to perform later replacement and maintenance.

[0064] In a further embodiment, the housing 32 includes a fixed housing 321, a detachable housing 322 and a sealing ring 323. The fixed housing 321 is fixed to the end cap 31 and is open on the side away from the end cap 31. The filter element 33 is inserted into the fixed housing 321. The detachable housing 322 is inserted into the fixed housing 321 from the open side of the fixed housing 321 and is relatively fixed to the fixed housing 321. The fixed housing 321 and the detachable housing 322 cooperate to form a receiving cavity, and the filter element 33 is disposed in the receiving cavity. The sealing ring 323 is disposed at the connection between the fixed housing 321 and the detachable housing 322.

[0065] Through the arrangement of the fixed housing 321 and the detachable housing 322, it is convenient to perform the assembly operation of the filter element 33. At the same time, in the later stage, when the filter element 33 cannot be effectively cleaned through the cleaning mode, the detachable housing 322 can be opened to take out the filter element 33 from the fixed housing 321 for replacement. This kind of arrangement is also more convenient for assembly.

[0066] In order to achieve the relative fixation of the fixed shell 321 and the removable shell 322, a positioning groove is opened on the inner side wall of the fixed shell 321, and a protrusion is set on the removable shell 322, and the protrusion is inserted into the positioning groove to relatively fix the fixed shell 321 and the removable shell 322. Considering the need for assembly and subsequent disassembly and maintenance, the cross-section of the protrusion is set to an arc shape, so that during the movement, the protrusion can drive the removable shell 322 to deform, and then insert into or leave the fixed shell 321, and the positioning groove can be set to be an annular groove, so that the protrusion can fall into the positioning groove when inserted from any place, and the relative rotation of the removable shell 322 and the fixed shell 321 will not affect the normal operation of the overall assembly. If the removable shell 322 and the fixed shell 321 need to be completely fixed, the protrusion and the positioning groove can be set one by one.

[0067] In addition, in addition to the filter element 33, a layer of waterproof and breathable membrane can also be provided in the shell 32. The waterproof and breathable membrane can be made of non-woven fabric. The waterproof and breathable membrane is used to block the moisture carried in the air to achieve moisture isolation.

[0068] In some embodiments, the gas circuit switching unit 4 includes a gas circuit block 41, a piston rod 42 and a driving member 43. The gas circuit block 41 is fixed on the housing 1. The gas circuit block 41 is provided with a first gas circuit 411, a second gas circuit 412 and a third gas circuit 413. The first gas circuit 411 is connected to the first interface 103, the second gas circuit 412 is connected to the second interface 104, and the third gas circuit 413 is connected to the third interface 201. The piston rod 42 is arranged in the gas circuit block 41 and extends to the first gas circuit 411, the second gas circuit 412 and the third gas circuit 413. The piston rod 42 is used to disconnect one of the first gas circuit 411 and the third gas circuit 413, and connect the second gas circuit 412 with the other. The driving member 43 is arranged in the gas circuit block 41 and is transmission-connected to the piston rod 42. The driving member 43 is used to push the piston rod 42 to move.

[0069] A connecting chamber is also provided on the gas circuit block 41, in which a piston rod 42 is provided, and the connecting chamber connects three gas circuits. A plurality of dividing heads are provided on the piston tube 42, and each dividing head is provided in the connecting chamber and tightly cooperates with the inner wall of the connecting chamber, thereby dividing the interior of the connecting chamber into a plurality of chambers. By moving and switching each chamber, the on-off states of the first gas circuit 411, the second gas circuit 412 and the third gas circuit 413 are changed, thereby realizing the switching of the gas circuits.

[0070] The driving member 43 can be a voice coil motor or an electromagnetic component to linearly drive the piston rod 42. If an electromagnetic component is selected, a reset spring connected to the piston rod 42 needs to be built into the connecting cavity to achieve power-off reset of the electromagnetic component.

[0071] In some embodiments, the gas path block 41 further includes a sealing ring 44. A plurality of insertion ports 414 are provided on the gas path block 41. The sealing rings 44 are respectively arranged in each of the insertion ports 414. The first interface 103 and the second interface 104 are respectively inserted into an insertion port 414 and contact the sealing ring 44 in the insertion port 414.

[0072] During assembly, the gas path block 41 can be placed outside the housing 1, and the first interface 103 and the second interface 104 are respectively inserted into two insertion ports 414 to form a connection. Then, the third interface 201 is connected to the gas path block 41. After the connection is completed, the gas path block 41 can be directly fixed to the housing 1 by using screws.

[0073] In some embodiments, the opening and closing control unit 5 includes a base 51, a movable rod 52 and a blocking ball 53. The base 51 is fixed in the intake pipe 2. The movable rod 52 is movably arranged on the base 51 and can move towards the connecting pipe 11. The blocking ball 53 is fixed at the end of the movable rod 52 and can be inserted into the opening side of the connecting pipe 11. The diameter of the blocking ball 53 is larger than the inner diameter of the connecting pipe 11.

[0074] Specifically, the opening and closing control unit 5 can select a device with a linear driving function, such as an electromagnetic component or a motor screw rod component, etc. The movable rod 52 is its linear moving rod. The blocking ball 53 is preferably a rubber part, which has a certain elasticity and can provide good sealing for the connecting pipe 11. It should be noted that for the opening and closing control unit 5, it can be powered by leading out a power cord from the pins inside the housing 1.

[0075] In some embodiments, in order to further improve the cleaning efficiency, a vibration member 6 is also provided. The vibration member 6 is arranged on the intake pipe 2. The vibration member 6 is used to drive the filter assembly 3 to vibrate. The vibration member 6 can select a vibration motor, which is connected to the intake pipe 2 by a fixing seat. During the self-cleaning operation, it generates a vibration force, and cooperates with the reciprocating blowing to form a vibration cleaning, thereby improving the cleaning efficiency and cleaning effect on the filter element 33.

[0076] The self-cleaning method of the fuel tank leakage diagnosis module of the present invention is used for the above-mentioned fuel tank leakage diagnosis module to clean the particulate impurities attached to the filter assembly 3. The self-cleaning method of the fuel tank leakage diagnosis module includes steps S1 - S4.

[0077] Step S1: Obtain real-time monitoring data.

[0078] The real-time monitoring data includes the real-time current of the diagnostic pump or the air flow data inside the intake pipe 2, such as air pressure, flow rate, etc. In this embodiment, the real-time current of the diagnostic pump is used as the real-time monitoring data for illustration. In the entire system, the vehicle main computer will collect the operating data of the diagnostic pump, including the motor current data of the diagnostic pump. If it is necessary to detect through the air flow data, sensors such as a pressure sensor and a flow sensor can be set inside the intake pipe 2. However, due to the limited space inside the intake pipe 2 and considering the installation of the entire module, it is preferred to use the data that can be collected by the vehicle itself to obtain the real-time monitoring data.

[0079] It should be noted that the real-time monitoring data does not need to be collected continuously, but can be collected at specific time intervals or determined according to conditions such as driving duration. The specific collection method can be set in the vehicle main computer.

[0080] Step S2: According to the real-time monitoring data, determine whether to perform a self-cleaning operation. If a self-cleaning operation is required, proceed to the next step; if a self-cleaning operation is not required, return to Step S1.

[0081] In this step, there are many ways to determine whether a self-cleaning operation is required through the real-time monitoring data. For example, before Step S1, a current threshold is set. When the real-time current reaches the current threshold, it is determined that a self-cleaning operation is required.

[0082] The principle of this setting is that the motor current of the diagnostic pump is proportional to the load torque. When the filter element 33 is blocked, the system resistance load increases, and the motor needs to output a greater torque to maintain the rotation speed, resulting in an increase in current.

[0083] Step S3: Switch the fuel tank leakage diagnosis module between the normal mode and the cleaning mode for a certain period of time. In the normal mode, the first interface 103 is connected to the second interface 104, and the opening and closing control unit 5 does not block the connecting pipe 11. In the cleaning mode, the gas path switching unit 4 connects the second interface 104 to the third interface 201, and the opening and closing control unit 5 blocks the connecting pipe 11.

[0084] In the cleaning mode, the intake pipe 2 is disconnected from the control chamber 101 and the air pump chamber 102. The connection and disconnection between the intake pipe 2 and the control chamber 101 are controlled by an electromagnetic valve in the control chamber 101, so that the gas in the control chamber 101 and the air pump chamber 102 can only be discharged through the second interface 104. When the diagnostic pump rotates, due to inertia and still being in a rotating state, the gas in the control chamber 101 and the air pump chamber 102 can be sent into the intake pipe 2 within a short time, creating a negative pressure in the control chamber 101 and the air pump chamber 102. The gas entering the intake pipe 2 will impact the filter assembly 3, causing the floating particulate impurities on it to enter the external atmosphere.

[0085] The back-and-forth switching between the cleaning mode and the normal mode enables the particulate impurities on the filter component 3 to gradually detach from the filter component 3 under the continuous change of air inlet and outlet, and be blown into the external atmospheric environment, thus forming a single self-cleaning operation.

[0086] Step S4: Record the number of self-cleaning operations within a certain period of time. If it exceeds a certain number, an alarm is issued. If it does not exceed a certain number, return to step S1.

[0087] If the current of the diagnostic pump cannot reach below the current threshold through one self-cleaning operation, return to step S1, re-monitor and cycle, so as to effectively remove the particulate impurities on the filter component 3 through multiple cleaning operations.

[0088] For equipment failures or situations where cleaning is ineffective, it can be achieved through another method. Specifically, a number threshold and a time statistical interval need to be set before step S1. When a cleaning operation starts once, the time statistical interval is started. If there is no subsequent cleaning operation, the data is cleared after the time statistical interval ends. Otherwise, the number of cleaning operations is recorded within the time statistical interval. If the number of cleaning operations reaches the number threshold, an alarm is issued by the vehicle-mounted host. If it does not reach, the data is cleared after the time statistical interval ends.

[0089] Among them, the number threshold can be set to three or more times, and the time statistical interval can be selected from 3h - 12h.

[0090] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A fuel tank leakage diagnosis module, characterized in that, It includes a housing (1), an air inlet pipe (2), a filtration component (3), an air path switching unit (4) and an opening / closing control unit (5). Among them, A control cavity (101), an air pump cavity (102), a first interface (103) and a second interface (104) are provided on the housing (1). The first interface (103) communicates with the control cavity (101), and the second interface (104) communicates with the air pump cavity (102); The air inlet pipe (2) is fixed on the housing (1). A third interface (201) is provided on the air inlet pipe (2). A connecting pipe (11) extending into the air inlet pipe (2) is provided on the housing (1). The air pump cavity (102) is communicated with the air inlet pipe (2) through the connecting pipe (11); The filtration component (3) is provided on the air inlet pipe (2), and the filtration component (3) is used to filter particulate impurities in the atmosphere; The air path switching unit (4) communicates with the first interface (103), the second interface (104) and the third interface (201), and makes the second interface (104) communicate with one of the first interface (103) and the third interface (201); The opening / closing control unit (5) is provided on the air inlet pipe (2) and has a blocking end, and the blocking end is used to block the connecting pipe (11); When the second interface (104) communicates with the third interface (201), the opening / closing control unit (5) blocks the connecting pipe (11), and the gas in the air pump cavity (102) enters the air inlet pipe (2) through the air path switching unit (4) and flows towards the atmosphere to clean the particulate impurities attached to the filtration component (3).

2. The fuel tank leakage diagnosis module according to claim 1, wherein The filtration component (3) includes an end cover (31), a housing (32) and a filter element (33). Among them, The end cover (31) is fixed at the end of the air inlet pipe (2); The housing (32) is fixed inside the end cover (31) and forms a gap with the end cover 31. The air inlet pipe (2) is inserted into this gap. The housing (32) blocks the end of the air inlet pipe (2), and air holes are provided on the housing (32); The filter element (33) is arranged inside the housing (32) so that the atmosphere can enter the housing (1) through the air holes and the filter element (33).

3. The fuel tank leakage diagnosis module according to claim 2, characterized in that, The housing (32) includes a fixed housing (321), a detachable housing (322) and a sealing ring (323). Among them, The fixed housing (321) is fixed on the end cover (31) and is provided with an opening on the side away from the end cover (31). The filter element (33) is inserted into the fixed housing (321); The detachable housing (322) is inserted into the fixed housing (321) from the opening side of the fixed housing (321) and is relatively fixed to the fixed housing (321). The fixed housing (321) and the detachable housing (322) cooperate to form an accommodation cavity, and the filter element (33) is arranged in the accommodation cavity; The sealing ring (323) is arranged at the connection between the fixed housing (321) and the detachable housing (322).

4. The fuel tank leakage diagnosis module according to claim 1, wherein The air path switching unit (4) includes an air path block (41), a piston rod (42) and a driving member (43). Among them, The air path block (41) is fixed on the outer shell (1). The air path block (41) is provided with a first air path (411), a second air path (412) and a third air path (413). The first air path (411) communicates with the first interface (103), the second air path (412) communicates with the second interface (104), and the third air path (413) communicates with the third interface (201). The piston rod (42) is arranged in the air path block (41) and extends into the first air path (411), the second air path (412) and the third air path (413). The piston rod (42) is used to disconnect one of the first air path (411) and the third air path (413) and connect the second air path (412) with the other one. The driving part (43) is arranged in the air path block (41) and is in transmission connection with the piston rod (42). The driving part (43) is used to push the piston rod (42) to move.

5. The fuel tank leakage diagnosis module according to claim 4, characterized in that The air path block (41) further includes a sealing ring (44). The air path block (41) is provided with a plurality of insertion ports (414). The sealing rings (44) are respectively arranged in the insertion ports (414). The first interface (103) and the second interface (104) are respectively inserted into an insertion port (414) and contact the sealing rings (44) in the insertion ports (414).

6. The fuel tank leakage diagnosis module according to claim 1, wherein The opening and closing control unit (5) includes a base (51), a movable rod (52) and a blocking ball (53). Among them, The base (51) is fixed in the air inlet pipe (2). The movable rod (52) is movably arranged on the base (51) and can move towards the connecting pipe (11). The blocking ball (53) is fixed at the end of the movable rod (52) and can be inserted into the opening side of the connecting pipe (11). The diameter of the blocking ball (53) is larger than the inner diameter of the connecting pipe (11).

7. The fuel tank leakage diagnosis module according to claim 1, wherein, It further includes a vibrating part (6). The vibrating part (6) is arranged on the air inlet pipe (2). The vibrating part (6) is used to drive the filter assembly (3) to vibrate.

8. A self-cleaning method for a fuel tank leakage diagnosis module, characterized in that, For the fuel tank leakage diagnosis module according to any one of claims 1-7, to clean the particulate impurities attached to the filter assembly (3), the self-cleaning method of the fuel tank leakage diagnosis module includes the following steps: S1 Obtain real-time monitoring data; S2 According to the real-time monitoring data, judge whether to perform self-cleaning operation. If self-cleaning operation is required, enter the next step. If self-cleaning operation is not required, return to step S1; S3 Switch the fuel tank leakage diagnosis module back and forth between the normal mode and the cleaning mode for a certain period of time. In the normal mode, the first interface (103) communicates with the second interface (104), and the opening and closing control unit (5) does not block the connecting pipe (11). In the cleaning mode, the air path switching unit (4) makes the second interface (104) communicate with the third interface (201), and the opening and closing control unit (5) blocks the connecting pipe (11); S4 Record the number of self-cleaning operations within a certain period of time. If it exceeds a certain number, issue a warning. If it does not exceed a certain number, return to step S1.

9. The self-cleaning method of the fuel tank leakage diagnosis module according to claim 8, characterized in that The real-time monitoring data includes the real-time current of the diagnostic pump.

10. The self-cleaning method of the fuel tank leakage diagnosis module according to claim 9, characterized in that, Before step S1, a current threshold is set. In step S2, when the real-time current reaches the current threshold, a self-cleaning operation is performed.

Images