Portable electric leakage switch intact intelligent detector

Abstract

The invention discloses a portable electric leakage switch intact intelligent detector, and belongs to the technical field of electric leakage testers. A portable electric leakage switch intact intelligent detector comprises a shell, a detector body used for detection is arranged in the middle of the interior of the shell, a cover plate is arranged at the upper end of the exterior of the shell, and a second fixing block used for connection is arranged in the middle of the other end of the shell. A rotatable front support is arranged in the middle of one end of the second fixing block. According to the intelligent detector, the problems that a rotating rod protruding out of equipment needs to be pressed and the protruding rotating rod affects portability of the equipment in an existing intelligent detector are solved, after a second handle is rotated and a second transmission rod is pulled, a first handle can be exposed, limitation on a cover plate is lost, the cover plate can be warped up after the first handle is pulled, and the detection efficiency is improved. The protruding structure is prevented from influencing the portability of the equipment, and the box opening mode is not complex.

Description

Technical Field

[0001] The present invention relates to the technical field of leakage testers, and specifically to a portable intelligent detector for the integrity of leakage switches. Background Art

[0002] A portable intelligent detector for the integrity of leakage switches is a portable device integrating detection, analysis, and judgment. It is specifically used to quickly and accurately detect whether the working state and performance of the leakage switch are intact. It can intelligently analyze key parameters such as leakage current and operating time to ensure that the leakage switch can cut off the power supply in a timely manner in case of an emergency, protecting personnel and equipment safety. This detector is characterized by being portable, efficient, and accurate, and is an important tool in the fields of power maintenance and safety detection, etc.

[0003] Chinese Patent with Publication No. CN117783935A discloses a leakage switch integrity intelligent detector and a detection method, including a transmission shaft. One end of the transmission shaft is fixedly connected to a small motor. A button box is arranged on one side of the small motor. Both the small motor and the button box are fixedly connected to the box body, and the small motor and the button box are electrically connected. By pressing the button box, the small motor is driven to rotate. The output shaft of the small motor is fixedly connected to the transmission shaft, so that the upper sliding column acts as a rotating shaft, and the lower sliding column can slide along the curved groove of the Y-shaped groove to its top, and then the rotating plate is flipped. The rotating plate is fixedly connected to the box cover, thereby realizing the automatic opening of the box cover. The box cover is convenient to open and fast to open.

[0004] When the intelligent detector of the above patent detects and connects the cable, it is necessary to press the rotating rod protruding outside the device. The protruding rotating rod will affect the portability of the device. On the other hand, during the process of unfolding the box cover, it is necessary to drive the small motor, and the output of the small motor can only realize the rotation and unfolding of the box cover. The way to open the box cover is relatively complex, resulting in a reduced service life. Summary of the Invention

[0005] The purpose of the present invention is to provide a portable intelligent detector for the integrity of leakage switches. After rotating and pulling the second transmission rod through the second handle, the first handle can be exposed and the restriction on the cover plate is also lost. After pulling the first handle, the cover plate can be tilted up, avoiding the influence of the protruding structure on the portability of the device, and the way to open the box is not complex, solving the problems raised in the above background art.

[0006] To achieve the above object, the present invention provides the following technical solutions: a portable intelligent detector for detecting the integrity of a leakage switch, including a housing. In the middle of the interior of the housing, there is a detector for detection. At the upper end of the exterior of the housing, there is a cover plate. At the middle position of the other end of the housing, there is a second fixing block for connection. At the middle position of one end of the second fixing block, there is a rotatable front bracket. On one side of the exterior of the front bracket, there is a second handle. One end of the second handle is rotatably connected to the front bracket through a fourth connecting shaft. On both sides of the other end of the cover plate, there are extension strips. Between both sides of the second handle and the extension strips respectively, there are first fixing blocks, and the first fixing blocks are welded and fixed to the housing.

[0007] Preferably, between the first fixing block and the extension strip, there is a slidable second transmission rod. On one side of each of the two sides of the front bracket facing the second transmission rod, there is a first transmission rod. The first transmission rod is rotatably connected to the front bracket through a third connecting shaft. The first transmission rod is rotatably connected to the second transmission rod through a second connecting shaft.

[0008] Preferably, at one end of the interior of the housing, there is a connecting rod. On the side of the connecting rod facing the second handle, there is a first handle. On the side of the connecting rod facing the detector, there is a first transmission piece welded. On both sides of the first transmission piece, there are second transmission pieces welded, and the second transmission pieces are welded and fixed to the first transmission piece.

[0009] Preferably, on the side of the second transmission piece facing the inner wall of the housing, there is a first tooth groove horizontally arranged. On the side of the first tooth groove facing the inner wall, there is a third transmission piece. Horizontally between the third transmission piece and the first tooth groove, there is a second tooth groove, and between the second tooth groove and the first tooth groove, there is a gear in meshing connection.

[0010] Preferably, at one end of the third transmission piece, there is a first inclined surface obliquely arranged. At one end of the first inclined surface, there is an extension piece. On the side of the extension piece facing the first inclined surface, there is a second inclined surface obliquely arranged.

[0011] Preferably, at one end of the detector, there is an installation cavity. At one end of the installation cavity, there is a fixing plate for wrapping. The lower end of the fixing plate is rotatably connected to the housing through a fifth connecting shaft.

[0012] Preferably, at the lower end of the installation cavity, there are three first installation cavities evenly distributed horizontally, and the first installation cavities are recessed inside the installation cavity. At one end of the exterior of the three first installation cavities, there are second installation cavities, and the second installation cavities are recessed inside the fixing plate.

[0013] Preferably, mounting holes penetrating the fixing plate are provided at the lower ends of the three second mounting cavities. Adaptation pieces are longitudinally arranged inside the second mounting cavities and the first mounting cavities, and springs for adaptation are arranged between the adaptation pieces and the interiors of the first mounting cavities and the second mounting cavities respectively.

[0014] Preferably, limiting blocks are provided on both sides of the second handle, and the limiting blocks and the second fixing block are of an integral structure.

[0015] Preferably, first magnets for magnetic connection are provided at both ends of the first transmission piece. A second magnet is provided at one end of one of the first magnets, and a third magnet is provided at one end of the other first magnet. The third magnet and the second magnet are both magnetically connected to the first magnet.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. By pulling the first handle, the first transmission piece can be directly driven to slide horizontally. During the horizontal sliding of the first transmission piece, after being driven by the gear, the third transmission piece can move towards one side of the first connecting shaft. The magnetic connection between the first magnet and the third magnet can continuously squeeze the cover plate, so that the cover plate can rotate and unfold around the first connecting shaft. The way of opening the cover plate is efficient. When there is no need to pull the first handle, the second handle will rotate around the fourth connecting shaft between the two front brackets, and the rotation can directly cover the surface of the first handle to prevent the first handle from being directly pulled. Correspondingly, when the second handle covers the surface of the first handle, the fixation of the first handle will fix the second transmission rods on both sides. The second transmission rods will be supported by the first fixing blocks and pass through the inside of the extension strips. When the second handle is not rotated, the rotation of the cover plate will be restricted by the extension strips. While restricting the direct pulling of the first handle from causing the cover plate to unfold, the connection between the cover plate and the housing can be further fixed by the passing of the second transmission rods. The overall connection structure and transmission structure are simple, and the pulling position is accommodated inside the housing without protruding positions, and the pulling position will not affect the portability of the device.

[0018] 2. After one end of the cable is inserted into the housing and connected to the detector, the other end of the cable extends out from the mounting hole position and is connected to the switch to be detected. For the fixation of the cable, the fixing plate can be directly rotated and moved towards the housing. After the fixing plate rotates around the fifth connecting shaft and is fixed by the threaded rod passing through, the connected cable will be accommodated between the first mounting cavity and the second mounting cavity, actively restricting the cable. While restricting the cable, the resilience of the spring will actively make the adaptation piece fit the two sides of the outer part of the cable. The contraction of the spring can make the adaptation piece adapt to cables of different calibers. With the pressing of the fixing plate, the connected cable can be fixed, improving the stability of the cable connection and preventing the cable from being easily pulled off. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a three-dimensional view of the overall external structure of the present invention;

[0020] Figure 2 is a schematic diagram of the movement trajectory of the first transmission rod of the present invention;

[0021] Figure 3 of the present invention Figure 2 is a partially enlarged view of area A in;

[0022] Figure 4 is a top view of the positional relationship of the connecting rod of the present invention;

[0023] Figure 5 of the present invention Figure 4 is a partially enlarged view of area B in;

[0024] Figure 6 is a schematic diagram of the positional relationship of the third transmission piece of the present invention;

[0025] Figure 7 is a sectional view of the external structure of the installation cavity of the present invention;

[0026] Figure 8 is a sectional view of the internal structure of the installation cavity of the present invention;

[0027] Figure 9 of the present invention Figure 8 is a partially enlarged view of area C in;

[0028] Figure 10 is a sectional view of the installation structure of the threaded rod of the present invention.

[0029] In the figure: 1. Outer shell; 2. Cover plate; 3. Rear bracket; 4. First connecting shaft; 5. Extension strip; 6. First fixing block; 7. First handle; 8. Second fixing block; 9. Limiting block; 10. Second handle; 11. First transmission rod; 12. Second transmission rod; 13. Second connecting shaft; 14. Front bracket; 15. Third connecting shaft; 16. Fourth connecting shaft; 17. Connecting rod; 18. First transmission piece; 19. Second transmission piece; 20. First tooth groove; 21. Gear; 22. Third transmission piece; 23. Second tooth groove; 24. First inclined surface; 25. Detector; 26. Fixed plate; 27. Third handle; 28. Extension piece; 29. First installation cavity; 30. Second installation cavity; 31. Installation hole; 32. Fifth connecting shaft; 33. Adapter piece; 34. Spring; 35. Threaded rod; 36. First magnet; 37. Second magnet; 38. Third magnet; 39. Second inclined surface; 40. Installation cavity. Specific Embodiments

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] In order to solve the problems that when the existing intelligent detector detects and connects a cable, it is necessary to press a rotating rod protruding outside the device, and the protruding rotating rod will affect the portability of the device. On the other hand, when the box cover is unfolded, it is necessary to drive a small motor, and the output of the small motor can realize the rotation and unfolding of the box cover. The way of opening the box cover is relatively complex, resulting in a reduced service life. The following technical solutions are provided in this embodiment:

[0032] A portable intelligent detector for intact leakage switches, including a housing 1. In the middle of the housing 1, there is a detector 25 for detection. The cable needs to provide a connection between the detection device and the detector 25, as Figure 1 and Figure 4 shown. At the upper end of the outside of the housing 1, there is a cover plate 2. On both sides of one end of the housing 1, there are rear brackets 3 for erection, and the rear brackets 3 and the cover plate 2 are rotatably connected through a first connecting shaft 4. After being pushed and restricted, the cover plate 2 can completely wrap the upper end of the outside of the housing 1 to realize the sealing of the internal structure of the housing 1. After the cover plate 2 rotates around the first connecting shaft 4, the detector 25 inside the housing 1 can be exposed, which is convenient for the connection and disassembly of the cable;

[0033] In this embodiment, on both sides of the other end of the cover plate 2, there are extension bars 5, and the extension bars 5 and the cover plate 2 are of an integral structure, as Figure 1 and Figure 2 shown. At the middle position of the other end of the housing 1, there is a second fixing block 8 for connection. At the middle position of one end of the second fixing block 8, there is a rotatable front bracket 14. On one side of the outside of the front bracket 14, there is a second handle 10. One end of the second handle 10 and the front bracket 14 are rotatably connected through a fourth connecting shaft 16. The rotation of the second handle 10 can expose the first handle 7. Similarly, when the second handle 10 rotates around the fourth connecting shaft 16, it can cover the outside of the first handle 7 to restrict the first handle 7 from being directly pulled;

[0034] In this embodiment, on both sides of the second handle 10, there are first fixing blocks 6 between the second handle 10 and the extension bars 5, and the first fixing blocks 6 are welded and fixed to the housing 1, as Figure 1 and Figure 2 shown. Between the first fixing block 6 and the extension bar 5, there is a slidable second transmission rod 12. After the second transmission rod 12 passes through the first fixing block 6 and the extension bar 5, it can restrict the rotation and unfolding of the cover plate 2;

[0035] In this embodiment, on both sides of the front bracket 14, a first transmission rod 11 is disposed on the side facing the second transmission rod 12. As shown in Figure 1 , Figure 2 and Figure 3 , the first transmission rod 11 is rotatably connected to the front bracket 14 through a third connecting shaft 15, and the first transmission rod 11 is rotatably connected to the second transmission rod 12 through a second connecting shaft 13. By the rotation of the second connecting shaft 13 and the third connecting shaft 15 and the restriction of the first fixed block 6 on the second transmission rod 12, the front bracket 14 can directly pull the second transmission rod 12 after rotation, so that the second transmission rod 12 extends out of the extension bar 5, facilitating the subsequent rotation and unfolding of the cover plate 2;

[0036] In this embodiment, at one end inside the housing 1, a connecting rod 17 is provided. On the side of the connecting rod 17 facing the second handle 10, a first handle 7 is provided, and the first handle 7 is fixedly welded to the connecting rod 17. As shown in Figure 4 and Figure 5 , on the side of the connecting rod 17 facing the detector 25, a first transmission piece 18 is welded. At both ends of the first transmission piece 18, first magnets 36 for magnetic connection are provided. At one end of one of the first magnets 36, a second magnet 37 is provided. At one end of the other first magnet 36, a third magnet 38 is provided, and both the third magnet 38 and the second magnet 37 are magnetically connected to the first magnet 36. Through magnetic connection, the first transmission piece 18 can be attached to the sliding position during the lateral movement, avoiding the need to continuously manually pull the first handle 7;

[0037] In this embodiment, second transmission pieces 19 are welded on both sides of the first transmission piece 18, and the second transmission pieces 19 are fixedly welded to the first transmission piece 18. As shown in Figure 4 and Figure 5 , when the first transmission piece 18 moves laterally, it will directly drive the second transmission pieces 19 to slide laterally. On the side of the second transmission piece 19 facing the inner wall of the housing 1, a first tooth groove 20 is horizontally provided. On the side of the first tooth groove 20 facing the inner wall of the housing 1, a third transmission piece 22 is provided. Between the third transmission piece 22 and the first tooth groove 20, a second tooth groove 23 is horizontally provided, and a gear 21 in meshing connection is provided between the second tooth groove 23 and the first tooth groove 20. After the second transmission piece 19 is pulled laterally, the first tooth groove 20 on the surface of the second transmission piece 19 will drive the gear 21 to rotate, and the rotation of the gear 21 will drive the third transmission piece 22 to slide laterally through the second tooth groove 23, causing the third transmission piece 22 to move towards the rear bracket 3;

[0038] In this embodiment, as shown in Figure 6As shown, one end of the third transmission piece 22 is inclined with a first inclined surface 24. One end of the first inclined surface 24 is provided with an extension piece 28. The surface of the extension piece 28 facing the first inclined surface 24 is inclined with a second inclined surface 39. During the lateral sliding of the third transmission piece 22, the first inclined surface 24 will contact the second inclined surface 39 at the position of the extension piece 28. Through extrusion and the restriction of the first connecting shaft 4, the cover plate 2 can be rotated to expose the upper end outside the housing 1, thereby realizing the rotation and unfolding of the cover plate 2 by pulling the connecting rod 17;

[0039] In this embodiment, one end of the detector 25 is provided with an installation cavity 40. The installation cavity 40 penetrates through the housing 1 and extends to the outer wall, as Figure 7 、 Figure 8 、 Figure 9 and Figure 10 shown. One end of the installation cavity 40 is provided with a fixing plate 26 for wrapping. The lower end of the fixing plate 26 is rotatably connected to the housing 1 through a fifth connecting shaft 32. The rotation of the fixing plate 26 can wrap the installation cavity 40, wrap and restrict the cable placed inside the installation cavity 40. Three first installation cavities 29 are evenly distributed horizontally at the lower end of the installation cavity 40, and the first installation cavities 29 are recessed inside the installation cavity 40. One end of the outside of the three first installation cavities 29 is provided with a second installation cavity 30, and the second installation cavity 30 is recessed inside the fixing plate 26. After the fixing plate 26 rotates and covers the outside of the installation cavity 40, the connected cable will be fixed between the first installation cavity 29 and the second installation cavity 30;

[0040] In this embodiment, as Figure 8 、 Figure 9 and Figure 10 shown, three mounting holes 31 penetrating through the fixing plate 26 are provided at the lower ends of the three second mounting cavities 30. The cable located between the first mounting cavity 29 and the second mounting cavity 30 will pass through the mounting holes 31, so that the cable can pass through the housing 1 while being fixed;

[0041] In this embodiment, fitting pieces 33 are longitudinally arranged inside the second mounting cavity 30 and the first mounting cavity 29. As Figure 8 and Figure 9 shown, the fitting pieces 33 are respectively provided with springs 34 for fitting inside the first mounting cavity 29 and the second mounting cavity 30. The resilience of the springs 34 can actively make the fitting pieces 33 fit the outer wall of the cable, adapting to cables of different shapes and clamping and fixing the cables at the same time;

[0042] In this embodiment, threaded rods 35 are respectively arranged through both sides inside the fixing plate 26. The outer parts of the threaded rods 35 are in threaded cooperation with the inner walls of the housing 1 and the fixing plate 26 respectively. As Figure 10As shown, a third handle 27 is welded to one end of the threaded rod 35. By pinching the third handle 27, the threaded rod 35 can be driven to rotate, facilitating the fixation of the fixing plate 26 and the clamping of the cable.

[0043] In this embodiment, limiting blocks 9 are provided on both sides of the second handle 10, and the limiting blocks 9 and the second fixing block 8 are of an integral structure. As Figure 1 shown, when the second handle 10 does not cover the surface of the first handle 7, the second handle 10 can be restricted by the limiting blocks 9 to prevent the second handle 10 from rotating and avoid loosening of the position of the second transmission rod 12.

[0044] Working principle: When using the device to check the leakage switch and it is necessary to open the cover plate 2 at the upper end of the housing 1, the second handle 10 rotates around the fourth connecting shaft 16 in the front support 14. After rotation, the second handle 10 is twisted. The second handle 10 drives the front support 14 to rotate counterclockwise in the second fixing block 8. The rotation of the front support 14 can pull the first transmission rod 11 through the third connecting shaft 15. The first transmission rod 11 can pull the second transmission rod 12 through the second connecting shaft 13, causing the second transmission rod 12 to slide in the first fixing block 6 and pull out from the extension strip 5. After rotating the second handle 10, the first handle 7 is exposed. Pulling the first handle 7 can drive the first transmission piece 18 to move horizontally by the connecting rod 17. The horizontal movement of the first transmission piece 18 can drive the gear 21 to rotate through the first tooth groove 20. The rotation of the gear 21 can drive the third transmission piece 22 to move horizontally through the second tooth groove 23, causing the third transmission piece 22 to push the extension piece 28 at the position of the first inclined surface 24, so that the cover plate 2 is squeezed and rotates and unfolds around the first connecting shaft 4. The cable connecting the detection device and the leakage switch extends into the interior of the housing 1. The cable will first be connected to the detector 25. The other end of the cable is inserted between one group of the first installation cavity 29 and the second installation cavity 30. After insertion, the internal cable passes through and exits from the corresponding installation hole 31. Rotate the fixing plate 26. The fixing plate 26 rotates around the fifth connecting shaft 32, so that the passing cable is fixed between the first installation cavity 29 and the second installation cavity 30. While the fixing plate 26 rotates, the resilience of the spring 34 will actively make the adapter piece 33 adapt to and fit the outer wall of the cable, and the fixation is achieved through clamping. Drive the threaded rod 35 through the fixing plate 26 by the third handle 27. After the threaded rod 35 generates relative movement with the inner wall of the housing 1, the movement of the threaded rod 35 can restrict the fixing plate 26 to fix the cable passing through the interior, and the connection of the cable enables the detector 25 to detect the leakage switch.

[0045] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0046] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. A portable intelligent leakage switch integrity detector, comprising a housing (1), a detector (25) for detection is arranged in the middle of the housing (1), and a cover plate (2) is arranged at the upper end of the housing (1), characterized in that: A second fixing block (8) for connection is arranged at the middle position of the other end of the shell (1), a rotatable front bracket (14) is arranged at the middle position of one end of the second fixing block (8), a second handle (10) is arranged on one side outside the front bracket (14), one end of the second handle (10) is rotatably connected to the front bracket (14) via a fourth connecting shaft (16), extension strips (5) are arranged on both sides of the other end of the cover plate (2), first fixing blocks (6) are arranged between the two sides of the second handle (10) and the extension strips (5), and the first fixing blocks (6) are welded and fixed to the shell (1).

2. The portable intelligent leakage switch integrity detector according to claim 1 is characterized by: A slidable second transmission rod (12) is arranged between the first fixed block (6) and the extension bar (5); first transmission rods (11) are arranged on both sides of the front bracket (14) facing the second transmission rod (12); the first transmission rod (11) and the front bracket (14) are rotationally connected via a third connecting shaft (15); and the first transmission rod (11) and the second transmission rod (12) are rotationally connected via a second connecting shaft (13).

3. The portable intelligent leakage switch integrity detector according to claim 1 is characterized by: A connecting rod (17) is provided at one end inside the housing (1); a first handle (7) is provided on a side of the connecting rod (17) facing the second handle (10); a first transmission plate (18) is welded to a side of the connecting rod (17) facing the detector (25); second transmission plates (19) are welded to both sides of the first transmission plate (18), and the second transmission plate (19) is welded and fixed to the first transmission plate (18).

4. The portable intelligent leakage switch integrity detector according to claim 3 is characterized by: A first tooth groove (20) is transversely arranged on one side of the second transmission plate (19) facing the inner wall of the housing (1), a third transmission plate (22) is disposed on one side of the first tooth groove (20) facing the inner wall of the housing (1), a second tooth groove (23) is transversely arranged between the third transmission plate (22) and the first tooth groove (20), and a gear (21) is disposed between the second tooth groove (23) and the first tooth groove (20) in meshing connection.

5. The portable intelligent leakage switch integrity detector according to claim 4 is characterized in that: A first inclined surface (24) is obliquely provided at one end of the third transmission plate (22), an extension plate (28) is provided at one end of the first inclined surface (24), and a second inclined surface (39) is obliquely provided on a side of the extension plate (28) facing the first inclined surface (24).

6. The portable intelligent leakage switch integrity detector according to claim 1 is characterized by: One end of the detector (25) is provided with a mounting cavity (40), one end of the mounting cavity (40) is provided with a fixing plate (26) for wrapping, and the lower end of the fixing plate (26) is rotatably connected to the housing (1) via a fifth connecting shaft (32).

7. The portable intelligent leakage switch integrity detector according to claim 6 is characterized by: Three first installation cavities (29) are evenly distributed laterally at the lower end of the installation cavity (40), and the first installation cavities (29) are recessed inside the installation cavity (40); a second installation cavity (30) is provided at one end outside the three first installation cavities (29), and the second installation cavity (30) is recessed inside the fixing plate (26).

8. The portable intelligent leakage switch integrity detector according to claim 7 is characterized in that: The lower ends of the three second mounting cavities (30) are each provided with a mounting hole (31) penetrating the fixing plate (26); the interiors of the second mounting cavities (30) and the first mounting cavities (29) are each longitudinally provided with an adapting piece (33); the adapting piece (33) is respectively provided with a spring (34) for adapting to the interiors of the first mounting cavity (29) and the second mounting cavity (30).

9. The portable intelligent leakage switch integrity detector according to claim 1 is characterized by: Limiting blocks (9) are provided on both sides of the second handle (10), and the limiting blocks (9) and the second fixing blocks (8) are an integral structure.

10. The portable intelligent leakage switch integrity detector according to claim 3 is characterized by: Both ends of the first transmission plate (18) are provided with first magnets (36) for magnetic connection, one end of one of the first magnets (36) is provided with a second magnet (37), and one end of another of the first magnets (36) is provided with a third magnet (38), and the third magnet (38) and the second magnet (37) are both magnetically connected to the first magnet (36).

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