Lightning arrester resistive current detection robot operation system

Abstract

The utility model provides a lightning arrester resistive current detection robot operation system, which belongs to the technical field of lightning arrester detection and comprises a current acquisition assembly, a voltage acquisition assembly, a detection robot, a test host and a butt joint assembly. The current acquisition assembly is used for completing acquisition of leakage current of the lightning arrester; the detection robot comprises a movable mechanical arm, a sampling end of the current acquisition assembly is connected with a current test line used for sampling, and the current test line is connected with the leakage ammeter through a butt joint assembly and is in short circuit with the leakage ammeter; the current acquisition assembly and the voltage acquisition assembly are both in communication connection with the test host. The lightning arrester resistive current live-line detection system has the advantages that workers are liberated from tedious and dangerous lightning arrester resistive current live-line detection work, timely and effective evaluation of lightning arrester state detection can be achieved, the time for processing and analyzing a large amount of data and feeding back information in the later period is saved, and the system has good engineering application and popularization value.

Description

Technical Field

[0001] The utility model belongs to the technical field of lightning arrester detection, and in particular relates to a lightning arrester resistive current detection robot operating system. Background Art

[0002] Lightning arresters are one of the important equipment to ensure the safe operation of power systems. Metal oxide arrester live tester is the main technical means for live testing of lightning arresters. Changes in leakage current can reflect defects such as moisture, aging, and poor contact of the arrester. By measuring the leakage current of the arrester under the operating voltage, it is generally possible to accurately determine whether the arrester has defects. Generally, operation and maintenance units need to conduct regular live testing of the arrester resistive current, and increase the frequency of testing when the arrester resistive current increases abnormally.

[0003] In the past, when conducting live testing on lightning arresters, workers were required to climb up. The higher the voltage level, the more advanced tools were needed to conduct the wiring, which could easily cause the testers to be injured by high voltage electricity such as induced electricity. The method of having workers conduct on-site testing near the lightning arrester was somewhat dangerous. Utility Model Content

[0004] The technical problem to be solved by the utility model is that it is dangerous to require workers to conduct on-site inspection near the lightning arrester. In view of the shortcomings of the prior art, a lightning arrester resistive current detection robot operation system is provided, which does not require workers to conduct on-site inspection near the lightning arrester.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0006] A lightning arrester resistive current detection robot operation system,

[0007] It includes a current acquisition component, a voltage acquisition component and a detection robot, and also includes a test host and a docking component; the current acquisition component and the test host are installed in the belly of the detection robot, and the voltage acquisition component is installed in the interior of the PT terminal box; the detection robot includes a movable mechanical arm, the sampling end of the current acquisition component is connected to a current test line for sampling, the current test line is arranged along the mechanical arm, and the mechanical arm is used to short-circuit the current test line with the leakage current meter through the docking component, so that the current acquisition component completes the acquisition of the arrester leakage current; the current acquisition component and the voltage acquisition component are both connected to the test host for communication, and the test host is used to obtain the arrester resistive current according to the arrester leakage current collected by the current acquisition component and the bus voltage data collected by the voltage acquisition component.

[0008] Furthermore, the detection robot also includes a moving component and a visual recognition component for movement, and the moving component includes a track wheel driven by the detection robot and a track installed on the track wheel.

[0009] Furthermore, it also includes a sub-wireless communication component and a main wireless communication component, the main wireless communication component is arranged inside the test host, the voltage acquisition component and the sub-wireless communication component are installed in the PT terminal box, the voltage acquisition component includes a voltage isolator, the voltage isolator is connected to the PT secondary terminal to extract the bus voltage waveform, the voltage acquisition component also includes a power supply, a controller and an A / D converter, the power supply supplies power to the voltage isolator and the sub-wireless communication component, the controller is used to control the power supply to supply power to the voltage isolator and the A / D converter, and the controller controls the A / D converter to convert the analog signal output by the voltage isolator into a digital signal and send it to the sub-wireless communication component.

[0010] Furthermore, two robotic arms are provided, and the docking assembly includes a cable clamp located at one end of the robotic arm.

[0011] Furthermore, the docking assembly includes an installation box installed on the lightning arrester rod body, the installation box is provided with a wire terminal block connected to the lead bolts on the leakage current meter and a ground terminal block connected to the ground wire bolts, one side of the wire terminal block and the ground terminal block are connected with lead wires, the docking assembly also includes a docking box installed on the lightning arrester rod body, one end of the lead wire is inserted into the interior of the docking box and connected to a docking socket, one end of the mechanical arm is equipped with a docking plug connected to the current test line, and the docking plug is plugged into the interior of the docking socket; the bottom of the ground terminal block is fixedly connected to a ground wire mounting frame, the front of the ground terminal block is fixedly installed with a connecting frame, the connecting frame is plugged with the leakage current meter, the ground wire is provided with a curved piece formed by bending at the installation position of the leakage current meter, and the ground wire mounting frame is fixedly installed with the curved piece.

[0012] Furthermore, a closed rack is installed inside the installation box, a closed cover is installed on the front of the installation box, a closed strip is fixedly installed on one side of the closed cover, the closed strip is plugged into the inside of the closed cover, a notch is provided on the front of the closed cover, a sealing ring is provided on the back of the closed cover cocentric with the notch, the front of the leakage current meter passes through the installation box through the notch, a guide rack is fixedly installed inside the docking box, a rain cover is fixedly installed on the front of the docking box, and a shielding panel is rotatably provided on the front of the rain cover.

[0013] Furthermore, a quick-insert barrel is fixedly installed on the front of the wire terminal block, a quick plug is installed on the back of the leakage current meter, the quick plug is plugged into the quick-insert barrel, an anti-detachment spring sheet is installed inside the quick-insert barrel, and the anti-detachment spring sheet is snap-fitted to the surface of the quick plug.

[0014] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0015] The utility model is to solve the problem of heavy workload and high danger of manual live testing of lightning arresters. A robot operation system is configured for the current work of live detection of resistive current of lightning arresters, that is, a robot operation system for live detection of resistive current of lightning arresters. The system can obtain current signals through the detection robot parked beside the lightning arrester by short-circuiting the two ends of the lightning arrester leakage current meter through a mechanical arm, and connect the upgraded busbar secondary measurement terminal through a voltage isolator that can be fixed inside the terminal box, and transmit the secondary voltage signal wirelessly; the test host establishes a communication connection with the voltage isolator, obtains the wireless voltage signal, and performs waveform synchronization calculation with the current measurement signal to obtain the resistive current and save and upload it, so as to complete the live detection of resistive current of lightning arresters. The system frees the staff from the tedious and dangerous work of live detection of resistive current of lightning arresters, and can realize the timely and effective evaluation of the state detection of lightning arresters, saving a large amount of data processing and analysis and information feedback time in the later stage, and has good engineering application and promotion value.

[0016] After the bus data is detected by the voltage acquisition component, it is sent to the test host through the sub-wireless communication component and the main wireless communication component, so that the detection robot is not restricted by wired transmission cables, the detection robot is more convenient to move, and the test host can simultaneously obtain the information sent by the current acquisition component and the voltage acquisition component, so as to calculate the resistive current. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0018] Figure 1 : A schematic diagram of the structure of the detection robot, the lightning arrester and the terminal box in Embodiment 1 of the present utility model;

[0019] Figure 2 : Schematic diagram of electrical connections and flow chart in Example 1 of the present utility model.

[0020] Figure 3 : A schematic diagram of the structure of the arrester body and the arrester rod body in Embodiment 2 of the present utility model;

[0021] Figure 4 : A schematic diagram of the structure of a cross-section of the installation box in Embodiment 2 of the present utility model;

[0022] Figure 5: A schematic cross-sectional view of the structure of the quick-insert barrel and the quick-plug in Embodiment 2 of the present utility model;

[0023] Figure 6 : A schematic diagram of the structure of a cross-sectional view of a docking box and a docking plug in Embodiment 2 of the present invention;

[0024] Among them, 10-current acquisition component, 11-current test line, 20-voltage acquisition component, 21-voltage isolator, 22-power supply, 23-controller, 24-A / D converter, 30- detection robot, 31- mechanical arm, 32- moving component, 33- visual identification component, 34- track wheel, 35- track, 36- cable clamp, 37- environmental temperature and humidity detector, 40- test host, 50- sub wireless communication component, 60- main wireless communication component, 70- docking component, 71- installation box, 72- busbar installation frame, 73- wire terminal block, 74- ground terminal block, 75- lead wire, 76- docking box, 77- docking seat, 78- docking plug, 79- connecting frame, 80- closed rack, 81- closed cover, 82- closed strip, 83- sealing ring, 84- quick plug cylinder, 85- quick plug, 86- anti-drop spring piece, 87- bent piece, 90- guide rack, 91- rain cover, 92- shielding panel, A- leakage current meter. DETAILED DESCRIPTION

[0025] In order to better understand the present invention, the content of the present invention is further clearly described below in conjunction with the embodiments and drawings, but the protection content of the present invention is not limited to the following embodiments. In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details.

[0026] Example 1: See Figure 1 , a lightning arrester resistive current detection robot operation system of this embodiment, which includes a current acquisition component 10, a voltage acquisition component 20 and a detection robot 30, and also includes a sub-wireless communication component 50 and a main wireless communication component 60, and also includes a test host 40 and a docking component 70;

[0027] The current collection component 10 and the test host 40 are installed in the belly of the detection robot 30, and the voltage collection component 20 is installed inside the PT terminal box; the main wireless communication component 60 is set inside the test host 40;

[0028] Whether the zinc oxide lightning arrester is aged or damp is usually determined by observing the change in the resistive current flowing through the zinc oxide lightning arrester under normal operating voltage, that is, whether the resistive leakage current increases.

[0029] However, resistive leakage current usually only accounts for 10% to 20% of the arrester leakage current; therefore, it is difficult to determine the change of resistive leakage current of zinc oxide arrester by only observing the change of leakage current through leakage current meter A on the arrester, and it is also impossible to accurately analyze and judge the performance of the arrester.

[0030] The current acquisition component 10 is used to complete the acquisition of the leakage current of the lightning arrester; the detection robot 30 includes a movable mechanical arm 31, the robot extends two mechanical arms 31, the sampling end of the current acquisition component 10 is connected to a current test line 11 for sampling, the current test line 11 is arranged along the mechanical arm 31, the current test line 11 is connected to the leakage current meter A through the docking component 70 to short-circuit the leakage current meter A, the free ends of the mechanical arms 31 are provided with cable clamps 36 electrically connected to the ends of the current test lines 11, the mechanical arms 31 control the cable clamps 36 to respectively clamp the lead bolts on the leakage current meter A and the bolts on the lower grounding wire to complete the short-circuiting of the leakage current meter A, so that the current test line 11 introduces the lightning arrester leakage current into the sampling end of the current acquisition component 10, and the current acquisition component 10 sends the collected data to the test host 40.

[0031] The current acquisition component 10 and the voltage acquisition component 20 are both connected to the test host 40 for communication. The test host 40 is used to obtain the arrester resistive current according to the arrester leakage current collected by the current acquisition component 10 and the bus voltage data collected by the voltage acquisition component 20. The bus voltage data obtained by the voltage acquisition component 20 is sent to the test host 40 through wireless communication between the sub-wireless communication component 50 and the main wireless communication component 60;

[0032] The test host 40 calculates the resistive current based on the bus voltage data and the arrester leakage current, which can be expressed as Ir=Ix / cosφ, where Ir is the resistive current to be solved, Ix is the fundamental component of the arrester leakage current, and φ is the phase difference between the bus voltage and the fundamental component of the arrester leakage current. Ix and φ are obtained by Fourier transforming the bus voltage and the leakage current.

[0033] The detection robot 30 also includes a moving component 32 for movement and a visual recognition component 33. The robot can identify the operation number of the lightning arrester device, the indication of the leakage current meter A, and whether there is condensation, cracks, etc. on the leakage current meter A through the visual recognition component 33, and can take pictures and automatically enter data; after the two robotic arms complete the short-circuiting of the two ends of the lightning arrester leakage current meter A, the robot's visual recognition component 33 should be able to check and determine whether the indication value of the leakage current meter A has returned to zero; the moving component 32 includes a track wheel 34 driven by the detection robot 30 and a track 35 installed on the track wheel 34. The robot can move close to the lightning arrester equipment under different terrains by moving on the track, thereby improving the robot's passability.

[0034] The voltage collection component 20 and the sub-wireless communication component 50 are installed in the PT terminal box. The voltage collection component 20 includes a voltage isolator 21, which is connected to the PT secondary terminal to extract the bus voltage data. For the existing PT terminal box, the secondary connector and the neutral line can be led out using an insulated shielded signal line, and then connected to the voltage isolator 21, so that the voltage isolator 21 can obtain the bus voltage data and send the bus voltage data through the sub-wireless communication component 50. The voltage acquisition component 20 also includes a power supply 22, a controller 23 and an A / D converter 24. The power supply 22 supplies power to the voltage isolator 21 and the sub-wireless communication component 50. The controller 23 is used to control the power supply 22 to supply power to the voltage isolator 21 and the A / D converter 24. The controller 23 controls the A / D converter 24 to convert the analog signal output by the voltage isolator 21 into a digital signal and send it to the sub-wireless communication component 50. In order to prevent external rain, snow, wind and sand from damaging the voltage isolator 21, the voltage isolator 21 is fixed inside the PT terminal box; in order not to affect the effective transmission of the wireless signal, the antenna of the sub-wireless communication component 50 is led to the outside of the PT terminal box and a protective cover is installed.

[0035] The voltage isolator 21 measures parameters such as voltage, converts them into standard analog signal output after isolation, and then converts them into digital signals through the A / D converter 24 and sends them to the sub-wireless communication component 50. The sub-wireless communication component 50 converts the digital signal into an analog signal suitable for radio transmission after modulation and sends it out. The main wireless communication component 60 in the test host 40 receives the signal and demodulates it into a digital signal.

[0036] In order to avoid frequent startup of the voltage isolator 21, the voltage isolator 21 is usually in a closed state. When the arrester resistive current detection is required, the test host 40 sends an activation signal to the voltage acquisition component 20 to start the voltage isolator 21. When all the arresters corresponding to the bus where the voltage isolator 21 is located are detected, a shutdown signal is sent to the voltage acquisition component 20 to shut down the voltage isolator 21.

[0037] Since the arrester resistive current live detection cannot be carried out in a high humidity environment, and the resistive current has a certain parameter relationship with the ambient temperature, the detection robot 30 is also equipped with an ambient temperature and humidity monitor 37. During the arrester resistive current test, the ambient temperature and humidity changes are collected in real time, and the ambient temperature and humidity data are input and uploaded. At the same time, the detection robot 30 can complete the inspection of the arrester area while moving, and timely check for safety hazards.

[0038] Beneficial effects:

[0039] 1. The system frees the staff from the tedious and dangerous work of live detection of lightning arrester resistive current, and can realize timely and effective evaluation of lightning arrester status detection, saving a lot of time for later data processing and analysis and information feedback, and has good engineering application and promotion value.

[0040] 2. After the bus voltage data is detected by the voltage acquisition component 20, it is sent to the test host 40 through the sub-wireless communication component 50 and the main wireless communication component 60, so that the detection robot 30 is not restricted by the wired transmission cable, the detection robot 30 is more convenient to move, and the test host 40 can simultaneously obtain the information sent by the current acquisition component 10 and the voltage acquisition component 20, which is convenient for calculating the resistive current.

[0041] Embodiment 2: Embodiment 2 is a further improvement made on the basis of Embodiment 1, see Figure 3-6 , a lightning arrester resistive current detection robot operation system of the present embodiment is different from that of embodiment 1 in that the docking assembly 70 does not include the cable clamp 36, and the docking assembly 70 includes an installation box 71 installed on the lightning arrester rod body, and a wire terminal block 73 connected to the lead bolt on the leakage current meter A and a ground terminal block 74 connected to the ground bolt are arranged in the installation box 71, and a lead wire 75 is connected to one side of the wire terminal block 73 and the ground terminal block 74. The docking assembly 70 also includes a docking box 76 installed on the lightning arrester rod body, and the lead wire 75 is led out so that the docking box 76 can be installed at a lower height to avoid the difficulty of docking the mechanical arm 31 due to the high height of the leakage current meter A. One end of the lead wire 75 penetrates into the interior of the docking box 76 and is connected to a docking seat 77. One end of the mechanical arm 31 is installed with a docking plug 78 connected to the current test line 11, and the docking plug The head 78 is plugged into the interior of the docking seat 77, and the docking plug 78 is movably inserted into the docking seat 77 through the mechanical arm 31, so that the current collection component 10 is connected to the wire terminal block 73 and the ground terminal block 74 through the current test line 11, the docking plug 78, the docking seat 77, and the lead-out line 75, thereby short-circuiting the leakage current meter A to complete the collection of leakage current data. The bottom of the ground terminal block 74 is fixedly connected to the ground mounting frame 72, and the front of the ground terminal block 74 is fixedly installed with a connecting frame 79, and the connecting frame 79 is plugged into the leakage current meter A. The ground wire is fixedly connected to a curved piece 87 formed by bending at the installation position of the leakage current meter A. The ground mounting frame 72 is fixedly installed with the curved piece 87, and a threaded hole is set on one side of the ground mounting frame 72 and the curved piece 87. The ground mounting frame 72 and the curved piece 87 are fixedly installed by screwing screws into the threaded holes.

[0042] See also Figure 3-6, a closed bracket 80 is installed inside the installation box 71, the leakage current meter A is installed in the installation box 71, and then the closed bracket 80 is covered on the front of the installation box 71, and a closed cover 81 is installed on the front of the installation box 71. A closed strip 82 is fixedly installed on one side of the closed cover 81, and the closed strip 82 is inserted into the closed cover 81. At this time, the front of the leakage current meter A passes through the notch, and the closed strip 82 is plugged into the inside of the closed cover 81. The closed strip 82 is made of rubber, and a notch is provided on the front of the closed cover 81. A sealing ring 83 is provided on the back of the closed cover 81 coaxial with the notch. The front of the leakage current meter A passes through the installation box 71 through the notch, and a part of the leakage current meter A is in contact with the sealing ring 83. At this time, the wire terminal block 73 and the ground terminal block 74 are It is enclosed inside the installation box 71 to prevent poor contact caused by water ingress, moisture, and aging of components from affecting the reading value of the leakage current meter A or causing damage. A guide rack 90 is fixedly installed inside the docking box 76, and a trapezoidal notch is provided on the front of the guide rack 90 to guide the docking plug 78 to dock. A rain cover 91 is fixedly installed on the front of the docking box 76, and a shielding panel 92 is rotatably provided on the front of the rain cover 91. The docking plug pushes open the shielding panel 92 to enter the interior of the docking box 76. At the same time, the docking plug 78 completes the docking with the docking seat 77 under the guidance of the guide rack 90, thereby reducing the accuracy requirement of the robot arm 31 in moving the docking plug 78 and facilitating docking. At the same time, the rain cover 91 prevents rainwater from entering the docking box 76 and affecting the collection of leakage current.

[0043] See also Figure 3-6 A quick-insertion tube 84 is fixedly installed on the front of the wire terminal block 73, and a quick plug 85 is installed on the back of the leakage current meter A. The quick plug 85 is plugged into the quick-insertion tube 84. An anti-detachment spring piece 86 is installed inside the quick-insertion tube 84. The anti-detachment spring piece 86 is snap-fitted with the surface of the quick plug 85. Pulling the leakage current meter A causes the quick plug 85 to squeeze the anti-detachment spring piece 86 and separate from the quick-insertion tube 84, and at the same time drives the closing cover 81 to separate from the installation box 71, so that the leakage current meter A can be quickly replaced, and maintenance is more convenient.

[0044] Beneficial effect: The lead-out wire 75 enables the docking box 76 to be installed at a lower height, thus preventing the leakage current meter A from being affected by its high height and thus affecting the docking of the mechanical arm 31; the wire terminal block 73 and the ground terminal block 74 are enclosed inside the installation box 71, thus preventing the leakage current meter A from being affected by poor contact or damaged due to water ingress and aging of components; at the same time, by means of plug-in, only one mechanical arm 31 is required to achieve the short-circuit of the current test line 11 and the leakage current meter A.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical solution of the utility model.

Claims

1. A lightning arrester resistive current detection robot operation system, characterized in that: It comprises a current collection component (10), a voltage collection component (20) and a detection robot (30), and also comprises a test host (40) and a docking component (70); The current collection component (10) and the test host (40) are installed inside the inspection robot (30), and the voltage collection component (20) is installed inside the PT terminal box; The detection robot (30) comprises a movable mechanical arm (31); a sampling end of the current collection component (10) is connected to a current test line (11) for sampling; the current test line (11) is arranged along the mechanical arm (31); the mechanical arm (31) is used to short-circuit the current test line (11) and the leakage current meter through the docking component (70), so that the current collection component (10) completes the collection of the arrester leakage current; The current acquisition component (10) and the voltage acquisition component (20) are both connected to a test host (40) for communication, and the test host (40) is used to obtain the arrester resistive current based on the arrester leakage current acquired by the current acquisition component (10) and the bus voltage data acquired by the voltage acquisition component (20).

2. The arrester resistive current detection robot operation system according to claim 1, characterized in that: The detection robot (30) further comprises a visual recognition component (33) and a moving component (32) for moving.

3. The arrester resistive current detection robot operation system according to claim 2, characterized in that: The moving component (32) comprises a track wheel (34) driven by the detection robot (30) and a track (35) mounted on the track wheel (34).

4. The arrester resistive current detection robot operation system according to claim 2, characterized in that: The invention also comprises a sub-wireless communication component (50) and a main wireless communication component (60), wherein the main wireless communication component (60) is arranged inside the test host (40), and the sub-wireless communication component (50) is installed in the PT terminal box. The voltage acquisition component (20) comprises a voltage isolator (21), and the voltage isolator (21) is connected to the PT secondary terminal to extract bus voltage data. The voltage acquisition component (20) also comprises a power supply (22), a controller (23) and an A / D converter (24), wherein the power supply (22) supplies power to the voltage isolator (21) and the sub-wireless communication component (50), and the controller (23) is used to control the power supply (22) to supply power to the voltage isolator (21) and the A / D converter (24), and the controller (23) controls the A / D converter (24) to convert the analog signal output by the voltage isolator (21) into a digital signal and send it to the sub-wireless communication component (50).

5. The arrester resistive current detection robot operation system according to any one of claims 1 to 4, characterized in that: Two mechanical arms (31) are provided, and the docking assembly (70) comprises a cable clamp (36) located at a free end of the mechanical arm (31).

6. The arrester resistive current detection robot operation system according to any one of claims 1 to 4, characterized in that: The docking assembly (70) comprises an installation box (71) installed on the arrester rod body, wherein a wire terminal block (73) connected to the lead bolt on the leakage current meter and a ground terminal block (74) connected to the ground bolt are arranged in the installation box (71), and one side of the wire terminal block (73) and the ground terminal block (74) are connected to a lead wire (75). The docking assembly (70) also comprises a docking box (76) installed on the arrester rod body, and one end of the lead wire (75) is inserted into the interior of the docking box (76) and connected to a docking seat (77). A docking plug (78) connected to the current test line (11) is installed at one end of the mechanical arm (31), and the docking plug (78) is plugged into the interior of the docking seat (77); a ground wire mounting frame (72) is fixedly connected to the bottom of the ground wire terminal block (74), a connecting frame (79) is fixedly installed on the front of the ground wire terminal block (74), and the connecting frame (79) is plugged into the leakage current meter; the ground wire is provided with a bent piece (87) formed by bending at the leakage current meter installation position, and the ground wire mounting frame (72) is fixedly installed with the bent piece (87).

7. The arrester resistive current detection robot operation system according to claim 6, characterized in that: A closed plug-in bracket (80) is installed inside the installation box (71), a closed cover (81) is installed on the front of the installation box (71), a closed strip (82) is fixedly installed on one side of the closed cover (81), the closed strip (82) is plugged into the inside of the closed cover (81), a notch is provided on the front of the closed cover (81), a sealing ring (83) is provided on the back of the closed cover (81) cocentrically with the notch, the front of the leakage current meter passes through the installation box (71) through the notch, a guide plug-in bracket (90) is fixedly installed inside the docking box (76), a rain cover (91) is fixedly installed on the front of the docking box (76), and a shielding panel (92) is rotatably provided on the front of the rain cover (91).

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