Mobile inspection device with self-cleaning function

By installing a mobile inspection device in the mine tunnel, using the self-cleaning function box and inspection components, the efficiency and safety issues of equipment inspection in the mine tunnel are solved, and efficient and accurate equipment monitoring is achieved.

CN223164568UActive Publication Date: 2025-07-29SHIJIAZHUANG TIEDAO UNIV
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Patent Information

Application Number
CN202422661066.7
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-11-01
Publication Date
2025-07-29
Estimated Expiration
2034-11-01

AI Technical Summary

Technical Problem

When conducting equipment inspections in mine tunnels, manual inspections are time-consuming and labor-intensive and have safety hazards. Video equipment is susceptible to coal dust accumulation and dust accumulation, resulting in poor monitoring effect.

Method used

A mobile inspection device with self-cleaning function is designed, including tracks, cabinets, walking mechanisms, detection components and cleaning mechanisms. The detection data is transmitted wirelessly to the central control room. A camera, infrared thermal imaging equipment, etc. are provided in the cabinet. The cleaning mechanism is used to automatically clean the lens dust to achieve self-cleaning.

Benefits of technology

It improves the efficiency and accuracy of equipment inspection in mine tunnels, reduces manpower and material costs, ensures the safety of construction personnel, and adapts to complex and harsh environments.

✦ Generated by Eureka AI based on patent content.

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Patent Text Reader

Abstract

The utility model discloses a mobile inspection device with a self-cleaning function, which belongs to the technical field of inspection equipment and comprises a track arranged along the inner wall of a tunnel and a box body with a traveling mechanism, and a battery, a positioning module, a controller and a detection assembly used for detecting environment and equipment in the tunnel are arranged in the box body. The positioning module, the walking mechanism and the detection assembly are all connected with the controller, and the controller can be in wireless connection with a center console of a central control room. The track is installed in the tunnel, the box body with the walking mechanism can carry the positioning module and the detection assembly to move along the track, tunnel environment parameters and equipment states detected by the detection assembly are wirelessly transmitted to a center console of a central control room through the controller, the detection position can be accurately determined, and the detection accuracy is improved. Working conditions in the tunnel can be known in time. Operators can remotely control in a central control room, and enter a tunnel for detection instead of manual work, so that the detection efficiency and accuracy are improved, and meanwhile, the personal health of the workers is also ensured.
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Description

Technical Field

[0001] The utility model belongs to the technical field of inspection equipment, and particularly relates to a mobile inspection device with a self-cleaning function. Background Art

[0002] At present, with the large-scale exploitation of mine tunnels, the operating equipment in the tunnels needs to ensure safe operation. However, due to the relatively harsh environment of most mines, manual inspection is not only time-consuming and laborious, but also poses great safety hazards. Installing video equipment in the tunnels for inspection is also restricted by conditions such as coal dust accumulation, low visibility, and cannot effectively monitor the equipment in the tunnels.

[0003] In view of this, it is necessary to develop a new type of mobile inspection device that can achieve the purpose of inspecting the operating equipment in mine tunnels under harsh conditions by means of a mobile method. Summary of the Utility Model

[0004] In order to solve the above problems, the utility model provides a mobile inspection device with a self-cleaning function.

[0005] To achieve the above purpose, the technical solutions adopted by the utility model are as follows:

[0006] A mobile inspection device with a self-cleaning function includes a track and a box body that can move. The track is arranged along the inner wall of the tunnel. The bottom of the box body is provided with a traveling mechanism that can move along the track. A battery, a positioning module, a controller, and a detection component for detecting the environment and equipment in the tunnel are arranged in the box body. The traveling mechanism, the controller, the positioning module, and the detection component are all connected to the battery. The positioning module, the traveling mechanism, and the detection component are all connected to the controller. The controller can be wirelessly connected to the console in the central control room;

[0007] The box body is a hollow shell. The detection components arranged in the box body include a camera, an infrared thermal imaging device, a temperature sensor, a humidity sensor, an oxygen content sensor, a smoke sensor, a gas sensor, and a distance sensor. The probes of the temperature sensor, the humidity sensor, the oxygen content sensor, the smoke sensor, the gas sensor, and the distance sensor penetrate the side wall of the box body and extend to the outside of the box body. A heat dissipation component is arranged on the side wall of the box body. Two monitoring windows are arranged on one side of the box body facing the construction equipment in the tunnel. The two monitoring windows are a rectangular window and a circular window respectively, and are used to match the lenses of the infrared thermal imaging device and the camera respectively. The lens of the camera extends to the outside of the circular window, and a cleaning mechanism is arranged outside the lens of the camera for cleaning the dust on the surface of the camera.

[0008] Further, the cleaning mechanism includes a folding shield and a micro motor. The two side shafts of the folding shield are connected to the side wall of the camera, and the micro motor is fixed on the side wall of the box body around the circular window. The fixed edge of the folding shield is fixedly connected to the upper part of the circular window, and the movable edge of the folding shield is connected to the output shaft of the micro motor. An arc-shaped rubber scraper is provided on the movable edge of the folding shield, and the scraper can be perpendicular to the surface of the camera.

[0009] Further, a dust removal mechanism is provided outside the lens of the infrared thermal imaging device for cleaning the dust on the surface of the lens of the infrared thermal imaging device. The dust removal mechanism includes an electric push rod and a scraper. The scraper is horizontally arranged across the rectangular window. The electric push rod is arranged on the side wall of the rectangular window. The middle part of the scraper is connected to the movable end of the electric push rod, and both ends of the scraper can be slidably matched with the guide grooves on the side surface of the rectangular window. The scraper is perpendicular to and contacts the surface of the lens of the infrared thermal imaging device.

[0010] Further, a strip-shaped rubber scraper is provided at the inner end of the scraper for contacting the surface of the lens of the infrared thermal imaging device.

[0011] Further, spray heads are also provided on the sides of the cleaning mechanism and the dust removal mechanism. The spray heads are arranged outside the box body and are connected to the pumping assembly. The pumping assembly includes a water tank, a water pump and a water pipe. The water pump and the water tank are arranged inside the box body. The water inlet of the water pump is connected to the water tank through a water pipe, and the water outlet of the water pump is connected to the spray heads through a water pipe. The spray heads are respectively used to spray water on the lens of the camera and / or the lens of the infrared thermal imaging device.

[0012] Further, the heat dissipation assembly includes a fan and a heat dissipation window. The fan is arranged inside the box body. The air inlet of the fan is arranged on the side wall of the box body and an air filter is provided at the air inlet. The air outlet of the fan faces the inside of the box body. The heat dissipation window is arranged at the air outlet on the side wall of the box body.

[0013] Further, the heat dissipation window includes a rectangular frame and a plurality of heat dissipation curtains. The plurality of heat dissipation curtains are overlapped in sequence from top to bottom. The upper end of the heat dissipation curtain is rotatably matched with the border of the frame. A convex part facing the inside is provided at the lower end of the heat dissipation curtain. The convex part at the lower end of the upper heat dissipation curtain can overlap on the outer side of the top of the lower heat dissipation curtain between two adjacent heat dissipation curtains.

[0014] Further, the traveling mechanism includes a servo motor and four traveling wheels that can move along the upper surface of the track. The servo motor is arranged inside the box body and can be connected to the rotating shaft of one of the traveling wheels. The four traveling wheels are arranged at the four corners of the bottom of the box body.

[0015] Furthermore, L-shaped eaves are symmetrically provided on both sides of the bottom of the box body. The two eaves can wrap the bottom edges on both sides of the track. A roller is provided on the upper surface of the eaves, and the roller can contact the bottom surface of the track.

[0016] Compared with the prior art, the technological progress achieved by the present utility model is as follows:

[0017] By installing a track in the tunnel, the box body with a traveling mechanism can carry a positioning module and a detection component to move along the track. The tunnel environment parameters and equipment status detected by the detection component are wirelessly transmitted to the console in the central control room through the controller, enabling the detection position to be accurately determined and the working conditions in the tunnel to be understood in a timely manner. The operator can remotely control in the central control room. The box body traveling along the track can replace manual labor to enter the tunnel for detection, improving the detection efficiency and accuracy, and at the same time ensuring the safety of construction workers. The present utility model can adapt to the complex environment of mine tunnels, greatly reducing the manpower, material resources and costs required for inspection under harsh environments, and significantly improving the safety and working efficiency of mine tunnel construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings are used to provide a further understanding of the present utility model and constitute a part of the specification. Together with the embodiments of the present utility model, they are used to explain the present utility model and do not constitute a limitation to the present utility model.

[0019] In the drawings:

[0020] Figure 1 is a schematic structural diagram of a mobile inspection device with a self-cleaning function provided by an embodiment of the present utility model;

[0021] Figure 2 is a schematic structural diagram of a cleaning mechanism in an embodiment of the present utility model;

[0022] Figure 3 is Figure 2 a schematic diagram of the folded state of the folding protective cover in

[0023] Figure 4 is a schematic structural diagram of a dust removal mechanism in an embodiment of the present utility model;

[0024] Figure 5 is a schematic structural diagram of a heat dissipation window in an embodiment of the present utility model;

[0025] Figure 6 is a schematic structural diagram of a traveling mechanism in an embodiment of the present utility model.

[0026] In the figure:

[0027] 1 - Orbit; 2 - Box body; 3 - Battery; 4 - Positioning module; 5 - Controller; 6 - Camera; 7 - Infrared thermal imaging device; 8 - Temperature sensor; 9 - Humidity sensor; 10 - Oxygen content sensor; 11 - Smoke sensor; 12 - Gas sensor; 13 - Distance sensor; 14 - Fan; 15 - Rectangular window; 16 - Circular window; 17 - Foldable shield; 18 - Micro motor; 19 - Electric push rod; 20 - Scraper; 21 - Scraping strip; 22 - Sprinkler head; 23 - Water pipe; 24 - Heat dissipation window, 240 - Protrusion, 241 - Rectangular frame, 242 - Heat dissipation curtain; 25 - Traveling wheel; 26 - Eaves; 27 - Roller. Detailed implementation mode

[0028] The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below with reference to the drawings.

[0029] As Figure 1 、 Figure 2 And Figure 3 shown, a mobile inspection device with a self - cleaning function provided by an embodiment of the present invention includes an orbit 1 and a movable box body 2. The orbit 1 is arranged along the inner wall of the tunnel. A traveling mechanism capable of moving along the orbit is provided at the bottom of the box body 2. A battery 3, a positioning module 4, a controller 5, and a detection component for detecting the environment and equipment in the tunnel are arranged in the box body 2. The traveling mechanism, the controller 5, the positioning module 4, and the detection component are all connected to the battery 3. The positioning module 4, the traveling mechanism, and the detection component are all connected to the controller 5. The controller 5 can be wirelessly connected to a console in the central control room (not shown in the figure). The box body carrying the detection component moves along the orbit, and the tunnel environment parameters and equipment status detected by the detection component are wirelessly transmitted to the console through the controller. The staff can accurately determine the detection position in the central control room and timely understand the working conditions in the tunnel. This solution can replace manual inspection in the tunnel, saving a large amount of manpower and material resources, and ensuring the personal health and safety of construction workers.

[0030] In a specific embodiment of the present invention, as Figure 1As shown, the box body 2 is a hollow shell. The detection components arranged inside the box body 2 include a camera 6, an infrared thermal imaging device 7, a temperature sensor 8, a humidity sensor 9, an oxygen content sensor 10, a smoke sensor 11, a gas sensor 12, and a distance sensor 13. The probes of the temperature sensor 8, humidity sensor 9, oxygen content sensor 10, smoke sensor 11, gas sensor 12, and distance sensor 13 penetrate the side wall of the box body 2 and extend to the outside of the box body 2. A heat dissipation component is provided on the side wall of the box body 2. On one side of the box body 2 facing the construction equipment in the tunnel, there are two monitoring windows, namely a rectangular window 15 and a circular window 16, which are respectively used to match the lenses of the infrared thermal imaging device 7 and the camera 6. The lens of the camera 6 extends to the outside of the circular window 16, and a cleaning mechanism is provided outside the lens of the camera 16 to clean the dust on the surface of the camera 16. The temperature sensor 8 and humidity sensor 9 are used to detect the surrounding temperature and humidity. The oxygen content sensor 10 and gas sensor 12 can detect the content of oxygen and harmful gases in the air. The distance sensor 13 can measure the distance traveled by the box body. At the same time, the smoke sensor 11 can be linked with a smoke alarm. When the detected smoke concentration in the air exceeds the upper limit, the smoke alarm can be activated to give an alarm. The camera 6 can be used to monitor the working conditions inside the tunnel. At the same time, in order to avoid missing equipment detection, an infrared thermal imaging device is specially installed. In this way, the problems that are difficult to observe with the camera 6 are obvious, especially problems such as equipment overload and overheating. The infrared thermal imaging device can quickly detect and give an alarm through the alarms at the site and in the central control room.

[0031] As a preferred structure, as Figure 2 , 3 shown, the cleaning mechanism includes a folding shield 17 and a micro motor 18. The two side shafts of the folding shield 17 are connected to the side wall of the camera 6. The micro motor 18 is fixed on the side wall of the box body 2 around the circular window 16. The fixed side of the folding shield 17 is fixedly connected to the upper part of the circular window 16. The movable side of the folding shield 17 is connected to the output shaft of the micro motor 18. An arc-shaped rubber scraping strip is provided on the movable side of the folding shield 17, and the scraping strip can be perpendicular to the surface of the camera 6. When the image obtained by the camera is blurred, the micro motor is started to wipe the spherical lens up and down with the folding shield to ensure a clear image is obtained.

[0032] In a specific embodiment of the present invention, as Figure 1 , 4As shown, a dust removal mechanism is provided outside the lens of the infrared thermal imaging device 7 for cleaning the dust on the surface of the lens of the infrared thermal imaging device 7. The dust removal mechanism includes an electric push rod 19 and a scraper 20. The scraper 20 is horizontally arranged across the rectangular window 15. The electric push rod 19 is arranged on the side wall of the rectangular window 15. The middle of the scraper 20 is connected to the movable end of the electric push rod 19. The two ends of the scraper 20 can be slidably matched with the guide grooves on the side surface of the rectangular window 15. The scraper 20 is perpendicular to and contacts the surface of the lens of the infrared thermal imaging device 7. Among them, a strip-shaped rubber scraping strip 21 is provided at the inner end of the scraper 20 for contacting the surface of the lens of the infrared thermal imaging device 7. When the surface of the lens of the infrared thermal imaging device 7 is covered with dust, it will affect the sensitivity and measurement accuracy of the device. At this time, the electric push rod needs to be started, and the scraper is used to wipe the surface of the lens up and down to ensure that the imaging can be detected in real time and the problem can be solved in time after it is discovered.

[0033] Further optimize the above solution. As Figure 3 shown, a spray head 22 is also provided on the side of the cleaning mechanism and the dust removal mechanism. The spray head 22 is arranged outside the box body 2 and is connected to a pumping component (not shown in the figure). The pumping component includes a water tank, a water pump and a water pipe. The water pump and the water tank are arranged inside the box body. The water inlet of the water pump is connected to the water tank through a water pipe, and the water outlet of the water pump is connected to the spray head 22 through a water pipe 23. The spray head 22 is respectively used to spray water on the lens of the camera 6 and / or the lens of the infrared thermal imaging device 7. When the dust adheres to the surface of the lens and is difficult to scrape off, the water pump can be started to spray water on the surface of the lens, and the cleaning purpose can be achieved by scraping repeatedly.

[0034] In a specific embodiment of the present invention, as Figure 1 shown, the heat dissipation component includes a fan 14 and a heat dissipation window 24. The fan 14 is arranged inside the box body 2. The air inlet of the fan 14 is arranged on the side wall of the box body 2, and an air filter is provided at the air inlet. The air outlet of the fan 14 faces the inside of the box body 2. The heat dissipation window 24 is arranged at the air outlet on the side wall of the box body 2. Among them, the air filter can be selected as a medium and low efficiency filter. By pre-cleaning the air inlet of the fan through the medium and low efficiency filter, excessive dust can be prevented from entering the box body and affecting the service life of other components. After the fan sucks air to cool and dissipate heat from the internal components, it is discharged from the air outlet of the box body.

[0035] During specific production, as Figure 5As shown, the heat dissipation window 24 includes a rectangular frame 241 and a plurality of heat dissipation curtains 242. The plurality of heat dissipation curtains 242 are overlapped in sequence from top to bottom. The upper end of the heat dissipation curtain 242 is rotationally matched with the border of the frame 241. The lower end of the heat dissipation curtain 242 is provided with a convex portion 240 facing the inside. The convex portion 240 at the lower end of the upper heat dissipation curtain 242 among two adjacent heat dissipation curtains 242 can overlap on the outer side of the top of the lower heat dissipation curtain 242. With the heat dissipation curtain of this structure, it can ensure that the air flow can impact the heat dissipation curtain and be discharged during the operation of the fan; after the fan stops running, the heat dissipation curtain naturally droops under the self-weight of the convex portion, preventing the outside polluted air from entering the box body through the heat dissipation window, and can effectively protect the components inside the box body.

[0036] In a specific embodiment of the present invention, as Figure 1 shown, the traveling mechanism includes a steering gear (not shown in the figure) and four traveling wheels 25 that can move along the upper surface of the track 1. The steering gear is arranged inside the box body 2 and can be connected to the rotating shaft of one of the traveling wheels 25. The four traveling wheels 25 are arranged at the four corners of the bottom of the box body 2. During specific manufacturing, as Figure 6 shown, L-shaped eaves 26 are symmetrically arranged on both sides of the bottom of the box body 2. The two-sided eaves 26 can wrap the bottom edges on both sides of the track 1. The upper surface of the eaves 26 is provided with rollers 27. The rollers 27 can contact the bottom surface of the track 1, which can reduce the resistance of the box body during operation. The traveling wheels are driven by the steering gear to verify the track driving, and at the same time, the box body is guided by the eaves on both sides of the box body to prevent the box body from detaching from the track.

[0037] During specific manufacturing, the battery 3 uses a lithium iron phosphate battery, which can be applicable to a humid dust environment. The battery is used to maintain the normal operation of the box body driving and its internal components. A charging station is set at the starting end of the track 1, and the battery is automatically charged by a sliding contact charging method. In addition, the positioning module can use a GPS module or a Beidou module, which can accurately locate. The steering gear and the micro motor both use servo motors. The forward and reverse rotations are used to realize the forward and backward movement of the box body and the opening and closing of the folding shield. The staff can realize the automatic control of the equipment in the central control room.

[0038] In summary, the utility model has the advantages of simple and compact structure, complete functions and good detection effect. The walking mechanism is used to drive the box body to move along the track in the tunnel. The visible light images and infrared thermal images of the operation state of the equipment in the tunnel are collected by the camera and infrared thermal imaging equipment carried by the box body. The data information of the tunnel environment is detected by temperature sensors, humidity sensors, oxygen content sensors, smoke sensors, gas sensors and distance sensors. The controller wirelessly transmits the parameters and equipment states detected by the detection components to the console. The operator can observe the working conditions in the tunnel and remotely control the start and stop of the box body in the control room. If a fault occurs in the operating equipment, the fault location can be accurately determined through the positioning module. Using the utility model to replace manual entry into the tunnel for circuit inspection and fault diagnosis of operating equipment and tunnel environment reduces the manpower, material resources and costs required for inspection in harsh environments, improves the detection efficiency and accuracy, and at the same time ensures the safety of construction personnel.

[0039] Finally, it should be noted that the above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the scope of protection of the claims of the present utility model.

Claims

1. A mobile inspection device with self-cleaning function, characterized by: It includes a track and a movable box body. The track is arranged along the inner wall of the tunnel. A traveling mechanism capable of moving along the track is provided at the bottom of the box body. A battery, a positioning module, a controller, and a detection component for detecting the tunnel environment and equipment are arranged inside the box body. The traveling mechanism, the controller, the positioning module, and the detection component are all connected to the battery. The positioning module, the traveling mechanism, and the detection component are all connected to the controller. The controller can be wirelessly connected to the console in the central control room; The box body is a hollow shell. The detection components arranged inside the box body include a camera, an infrared thermal imaging device, a temperature sensor, a humidity sensor, an oxygen content sensor, a smoke sensor, a gas sensor, and a distance sensor. The probes of the temperature sensor, the humidity sensor, the oxygen content sensor, the smoke sensor, the gas sensor, and the distance sensor penetrate through the side wall of the box body and extend to the outside of the box body. A heat dissipation component is provided on the side wall of the box body. Two monitoring windows are provided on one side of the box body facing the construction equipment in the tunnel. The two monitoring windows are a rectangular window and a circular window respectively, which are used to match the lenses of the infrared thermal imaging device and the camera respectively. The lens of the camera extends to the outside of the circular window, and a cleaning mechanism is provided outside the lens of the camera for cleaning the dust on the surface of the camera.

2. The mobile inspection device with self-cleaning function according to claim 1, wherein: The cleaning mechanism includes a folding cover and a micro motor. The two side shafts of the folding cover are connected to the side wall of the camera. The micro motor is fixed on the side wall of the box body around the circular window. The fixed side of the folding cover is fixedly connected to the upper part of the circular window. The movable side of the folding cover is connected to the output shaft of the micro motor. An arc-shaped rubber scraping strip is provided on the movable side of the folding cover, and the scraping strip can be perpendicular to the surface of the camera.

3. The mobile inspection device with self-cleaning function according to claim 1, characterized in that: A dust removal mechanism is provided outside the lens of the infrared thermal imaging device for cleaning the dust on the surface of the lens of the infrared thermal imaging device. The dust removal mechanism includes an electric push rod and a scraping plate. The scraping plate is horizontally arranged across the rectangular window. The electric push rod is arranged on the side wall of the rectangular window. The middle part of the scraping plate is connected to the movable end of the electric push rod. The two ends of the scraping plate can be slidably matched with the guide grooves on the side surface of the rectangular window. The scraping plate is perpendicular to and contacts the surface of the lens of the infrared thermal imaging device.

4. The mobile inspection device with self-cleaning function according to claim 3, characterized in that: A long strip-shaped rubber scraping strip is provided at the inner end of the scraping plate for contacting the surface of the lens of the infrared thermal imaging device.

5. The mobile inspection device with self-cleaning function according to claim 3, characterized in that: Spray heads are also provided on the sides of the cleaning mechanism and the dust removal mechanism. The spray heads are arranged outside the box body and are connected to a pumping component. The pumping component includes a water tank, a water pump, and a water pipe. The water pump and the water tank are arranged inside the box body. The water inlet of the water pump is connected to the water tank through a water pipe, and the water outlet of the water pump is connected to the spray heads through a water pipe. The spray heads are respectively used for spraying water on the lens of the camera and / or the lens of the infrared thermal imaging device.

6. The mobile inspection device with self-cleaning function according to claim 1, characterized in that: The heat dissipation component includes a fan and a heat dissipation window. The fan is arranged inside the box body. The air inlet of the fan is arranged on the side wall of the box body, and an air filter is provided at the air inlet. The air outlet of the fan faces the inside of the box body. The heat dissipation window is arranged at the air outlet on the side wall of the box body.

7. The mobile inspection device with self-cleaning function according to claim 6, characterized in that: The heat dissipation window includes a rectangular frame and a plurality of heat dissipation curtains. The plurality of heat dissipation curtains are overlapped in sequence from top to bottom. The upper end of the heat dissipation curtain is rotatably matched with the frame border. The lower end of the heat dissipation curtain is provided with a convex part facing the inside. The lower end convex of the upper heat dissipation curtain can overlap on the outer side of the top of the lower heat dissipation curtain among two adjacent heat dissipation curtains.

8. A mobile inspection device with a self-cleaning function according to any one of claims 1-7, characterized in that: The traveling mechanism includes a servo motor and four traveling wheels capable of moving along the upper surface of the track. The servo motor is arranged inside the box body and can be connected to the rotating shaft of one of the traveling wheels. The four traveling wheels are arranged at the four corner parts of the bottom of the box body.

9. The mobile inspection device with self-cleaning function according to claim 8, characterized in that: L-shaped eaves are symmetrically arranged on both sides of the bottom of the box body. The two side eaves can wrap the bottom edges on both sides of the track. Rollers are arranged on the upper surface of the eaves, and the rollers can contact the bottom surface of the track.