Pay-off device for ground resistance measuring instrument

Abstract

The utility model relates to the technical field of ground resistance measurement, discloses a pay-off device for a ground resistance measuring instrument, and solves the problems that in the existing ground resistance measurement, pay-off is carried out through a winding wheel, friction force of the winding wheel needs to be overcome, the lead pulling-out speed is limited due to the influence of the perimeter of the winding wheel, and the ground resistance measurement is influenced. And the efficiency is not high in the actual paying-off process. A wire harness is wound through the first winding frame and the second winding frame, and when paying-off is needed, two paying-off modes exist, one mode is that the driving mechanism is controlled to rotate reversely to enable the first winding frame and the second winding frame to rotate reversely to pay off a wire for use, and the other mode is that a limiting clamp connected to one side of the second winding frame is disassembled to enable the wire to be used. And after the coil is taken down, the coil can be paid off in a manual paying-off mode so as to cope with different manual using habits, and the coil taking-off device can be used in a matched mode.

Description

Technical Field

[0001] The utility model relates to the technical field of grounding resistance measurement, in particular to a wire releasing device for a grounding resistance measuring instrument. Background Art

[0002] A grounding resistance measuring instrument is a device used to measure the grounding resistance, and it plays an important role in seismic monitoring. This device can evaluate the performance of the grounding system, ensure that the grounding resistance value is within a safe range, so as to guarantee the normal operation of seismic monitoring equipment and the accuracy of data.

[0003] The existing publication number is CN219799605U, which discloses "a grounding resistance measuring instrument", including a wire winding frame, a storage cavity, a winding wheel, and a wire threading hole. Since the wire winding frame is fixed on the outer wall of the measuring instrument body, and the wire harness is wound on the winding wheel inside the storage cavity, when in use, pulling one end of the wire harness makes the winding wheel rotate, and the wire harness can be pulled out. After use, rotating the winding wheel in the reverse direction can wind up the wire harness, thus facilitating the storage of the wire harness. It is not only convenient for storage, but also will not cause the wire harness to break at the bending place;

[0004] However, the lengths of the wire harnesses used for the grounding resistance measuring instrument are generally divided into three types, namely: 5 meters long for connecting the grounding body to be measured, 20 meters long for connecting the potential probe, and 40 meters long for connecting the current probe; for the longer wire harnesses, after the wire harness is wound up by the above-mentioned winding wheel and then pulled out for the second time, the friction of the winding wheel needs to be overcome, and affected by the circumference of the winding wheel, the pulling speed is also limited. These two reasons limit the pulling speed of the wire harness, resulting in lower efficiency in actual wire releasing than manual wire releasing. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a wire releasing device for a grounding resistance measuring instrument, which solves the problems that after the wire used in the grounding resistance is wound up by a winding wheel and then released, the friction of the winding wheel needs to be overcome, and affected by the circumference of the winding wheel, the pulling speed of the wire is limited, resulting in low efficiency in actual wire releasing.

[0006] To achieve the above purpose, the utility model provides the following technical solution: A wire releasing device for a grounding resistance measuring instrument, including the grounding resistance measuring instrument body, a driving mechanism is fixedly installed on one side of the grounding resistance measuring instrument body, and a wire winding component for winding the wire harness is detachably connected to one side of the driving mechanism;

[0007] The wire winding assembly includes a first winding rack detachably connected to the driving mechanism. A second winding rack is detachably connected to one side of the first winding rack, and a limiting clip is detachably connected to one side of the second winding rack. The driving mechanism drives the first winding rack, the second winding rack, and the limiting clip to rotate coaxially. Both the first winding rack and the second winding rack are used for winding wire harnesses, and the wound wire harnesses can be detached on one side of the first winding rack and the second winding rack.

[0008] Preferably, a plurality of second winding racks are provided between the first winding rack and the limiting clip, and adjacent second winding racks are detachably connected. The first winding rack and the limiting clip are respectively connected to the head and tail of the plurality of connected second winding racks.

[0009] Preferably, the structures of the first winding rack, the second winding rack, and the limiting clip are respectively composed of corresponding combinations of bent rods, docking rods, outer hoop rings, and inner hoop rings. The diameter of the outer hoop ring is larger than that of the inner hoop ring. Both the first winding rack and the second winding rack include one outer hoop ring and two inner hoop rings. The outer hoop ring and the two inner hoop rings are arranged coaxially and equidistantly in the direction from the driving mechanism to the limiting clip. A plurality of bent rods arranged in a ring are commonly connected to the outer surfaces of the outer hoop ring and the inner hoop rings, and the connection of the bent rods to the two inner hoop rings is arranged horizontally.

[0010] Preferably, a card hole is opened at one end of the bent rod away from the outer hoop ring. Docking rods corresponding to the bent rods one by one are annularly arranged on the inner side of the outer hoop ring of the second winding rack. The bent rod and the docking rod are docked into a U-shaped frame, and the opening of the U-shaped frame is on the side away from the center of the inner hoop ring. A locking pin is arranged at one end of the docking rod close to the bent rod, and the locking pin is inserted and connected with the card hole.

[0011] Preferably, the limiting clip includes one outer hoop ring, and docking rods corresponding to the bent rods on the second winding rack are annularly arranged on the inner side of the outer hoop ring.

[0012] Preferably, a pair of ball cards are movably embedded on the arc surface of the locking pin. The ball cards are symmetrically arranged on the arc surface of the locking pin, and a spring is arranged between the two ball cards. An annular card slot matched with the ball cards is opened on the inner wall of the card hole.

[0013] Preferably, the driving mechanism includes an annular guide rail fixedly installed on one side of the grounding resistance measuring instrument body. A rotating ring is rotatably arranged inside the annular guide rail. A plurality of arc-shaped elastic hooks are annularly arranged inside the rotating ring, and the arc-shaped elastic hooks elastically buckle the outer hoop ring of the first winding rack. The outer surface of the annular guide rail is fixedly connected with a servo motor, the output end of the servo motor is connected with a gearbox, the output gear of the gearbox penetrates through the surface of the annular guide rail and is in transmission connection with the rotating ring, and a toothed groove matched with the output gear is opened on the outer surface of the rotating ring.

[0014] Preferably, a wire arranging mechanism for guiding the wire harness to be wound is arranged on one side of the rotating direction of the wire winding assembly. The wire arranging mechanism includes a fixed seat fixedly installed on the outer surface of the annular guide rail. One side of the fixed seat is fixedly connected with a cross bar parallel to the rotating shaft of the wire winding assembly. A wire guiding wheel is rotatably arranged on the surface of the cross bar. A plurality of wire guiding wheels are provided and correspond to the first winding frame and the second winding frame one by one. A twist groove is also formed on the surface of the cross bar. The inner wall of the wire guiding wheel fitting the surface of the cross bar is provided with a guiding convex ball. The guiding convex ball is a thread groove with opposite directions, cross - arranged and connected end to end. The guiding convex ball moves in the twist groove.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] The present utility model aims to provide a wire paying - out device for a grounding resistance measuring instrument. By assembling the first winding frame, the second winding frame and the limit clip, and then driving the first winding frame and the second winding frame to rotate through a driving mechanism, the first winding frame and the second winding frame can wind the wire harness. When the wire is needed, the driving mechanism can be controlled to reverse, so that the first winding frame and the second winding frame reverse to pay out the wire for use. The limit clip connected to the second winding frame can also be removed on one side of the second winding frame. At this time, the coil wound on the surface of the second winding frame can be taken down completely. Similarly, the second winding frame connected to the first winding frame can be removed on one side of the first winding frame, and the coil wound on the surface of the first winding frame can be taken down completely. After the coil is taken down completely, the operator can pay out the wire manually. In this way, there are two options for the manual wire - paying - out method, which can be adapted to different operator's usage habits. Description of the Drawings

[0017] Figure 1 is the overall structural schematic diagram of the present utility model;

[0018] Figure 2 is the connection structural schematic diagram of the wire winding assembly, the driving mechanism and the wire arranging mechanism of the present utility model;

[0019] Figure 3 is the disassembled structural schematic diagram of the wire winding assembly of the present utility model;

[0020] Figure 4 is the structural schematic diagram of the driving mechanism of the present utility model;

[0021] Figure 5 is the structural schematic diagram of the wire arranging mechanism of the present utility model;

[0022] Figure 6 is the connection structural schematic diagram of the cross - section of the locking pin and the card hole of the present utility model.

[0023] In the figure: 1. Body of the grounding resistance measuring instrument; 2. Wire winding assembly; 21. First wire reel; 22. Second wire reel; 23. Limit clip; 24. Bent rod; 241. Card hole; 242. Annular card slot; 25. Docking rod; 26. Locking pin; 261. Card ball; 262. Spring; 27. Outer hoop; 28. Inner hoop; 3. Driving mechanism; 31. Servo motor; 32. Annular guide rail; 33. Rotating ring; 34. Arc-shaped elastic catch; 4. Wire arranging mechanism; 41. Fixed seat; 42. Cross bar; 43. Wire guide wheel; 44. Twisted slot; 45. Guide convex ball. Detailed implementation

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0025] To further understand the content of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings.

[0026] Please refer to Figures 1 - 6 , a wire releasing device for a grounding resistance measuring instrument, including the body 1 of the grounding resistance measuring instrument, a driving mechanism 3 is fixedly installed on one side of the body 1 of the grounding resistance measuring instrument, and a wire winding assembly 2 for winding wire harnesses is detachably connected to one side of the driving mechanism 3;

[0027] The wire winding assembly 2 includes a first wire reel 21 detachably connected to the driving mechanism 3, a second wire reel 22 is detachably connected to one side of the first wire reel 21, a limit clip 23 is detachably connected to one side of the second wire reel 22, the driving mechanism 3 drives the first wire reel 21, the second wire reel 22, and the limit clip 23 to rotate coaxially, both the first wire reel 21 and the second wire reel 22 are used for winding wire harnesses, and the wound wire harnesses can be removed from one side of the first wire reel 21 and the second wire reel 22.

[0028] The above working principle and technical effect: By assembling the first wire reel 21, the second wire reel 22 and the limit clip 23, and then driving the first wire reel 21 and the second wire reel 22 to rotate through the driving mechanism 3, the first wire reel 21 and the second wire reel 22 can wind the wire harnesses, so that the two wire harnesses are respectively wound on the surfaces of the first wire reel 21 and the second wire reel 22, thereby completing the winding and storage of the wire harnesses. The limit clip 23 is used to limit the wire harness wound on the surface of the connected second wire reel 22 to prevent the wound wire harness from falling off from the side;

[0029] When the wire is needed, in addition to controlling the reverse rotation of the driving mechanism 3 to reverse the first wire winding frame 21 and the second wire winding frame 22 to release the wire for use, the limiting clip 23 connected to the side of the second wire winding frame 22 can also be removed. At this time, the coil wound on the surface of the second wire winding frame 22 can be completely removed. Similarly, the second wire winding frame 22 connected to the side of the first wire winding frame 21 can be removed, and the coil wound on the surface of the first wire winding frame 21 can be completely removed. After the coil is completely removed, the operator can release the wire manually. In this way, there are two options for manual wire release, which can be adapted to different operator's usage habits.

[0030] Further, a plurality of second wire winding frames 22 are provided between the first wire winding frame 21 and the limiting clip 23. The adjacent two second wire winding frames 22 are detachably connected, and the first wire winding frame 21 and the limiting clip 23 are respectively connected to the head and tail of the plurality of connected second wire winding frames 22.

[0031] Specifically, through the design of a plurality of second wire winding frames 22, multiple bundles of wire harnesses can be wound and stored simultaneously, improving convenience.

[0032] In the previous embodiment: the structures of the first wire winding frame 21, the second wire winding frame 22, and the limiting clip 23 are respectively composed of corresponding combinations of the bent rod 24, the docking rod 25, the outer hoop 27, and the inner hoop 28. The diameter of the outer hoop 27 is larger than that of the inner hoop 28. The first wire winding frame 21 and the second wire winding frame 22 both include an outer hoop 27 and two inner hoops 28. The outer hoop 27 and the two inner hoops 28 are arranged coaxially and equidistantly in the direction from the driving mechanism 3 to the limiting clip 23. A plurality of bent rods 24 arranged in a ring are commonly connected to the outer surfaces of the outer hoop 27 and the inner hoop 28. The connection between the bent rod 24 and the two inner hoops 28 is horizontally arranged;

[0033] A card hole 241 is opened at one end of the bent rod 24 away from the outer hoop 27. Docking rods 25 corresponding to the bent rods 24 one by one are annularly arranged inside the outer hoop 27 of the second wire winding frame 22. The bent rod 24 and the docking rod 25 are docked into a U-shaped frame. The opening of the U-shaped frame is on the side away from the center of the inner hoop 28. A locking pin 26 is arranged at one end of the docking rod 25 close to the bent rod 24. The locking pin 26 is inserted and connected with the card hole 241.

[0034] Specifically, the outer hoop 27 and the inner hoop 28 are responsible for supporting the plurality of bent rods 24. After the U-shaped frame formed by the combination of the bent rod 24 and the docking rod 25 is arranged in a ring, the wire harness can be wound and the wound wire harness can be prevented from coming off. After the bent rod 24 and the docking rod 25 are disassembled, the wire harness wound on the surface of the bent rod 24 can be removed for manual wire release.

[0035] Furthermore, the limiting clamp 23 includes an outer hoop 27 , and a connecting rod 25 corresponding to the bending rod 24 on the second winding frame 22 is provided in an annular manner inside the outer hoop 27 .

[0036] Specifically, the limit clamp 23 is connected to one side of a second winding frame 22 away from the driving mechanism 3, and the docking rod 25 on the limit clamp 23 is used to combine with the bending rod 24 on the second winding frame 22 to form a U-shaped frame so that the second winding frame 22 can wind up the wire harness, and the docking rod 25 on the limit clamp 23 is separated from the connected bending rod 24, thereby facilitating the removal of the wire harness wound on the second winding frame 22.

[0037] In the previous embodiment: a pair of snap-in balls 261 are movably embedded in the arc surface of the locking pin 26, and the snap-in balls 261 are symmetrical on the arc surface of the locking pin 26, a spring 262 is arranged between the two snap-in balls 261, and an annular snap-in groove 242 cooperating with the snap-in balls 261 is provided on the inner wall of the snap-in hole 241.

[0038] Specifically, when the locking pin 26 is inserted into the locking hole 241, the locking ball 261 is stuck on the inner side of the annular locking groove 242 by the push of the spring 262, so that the bending rod 24 and the docking rod 25 establish a locking connection. When the docking rod 25 is pulled outward with force on one side of the bending rod 24, the locking ball 261 will retract into the locking pin 26 under the action of pressure, so that the locking pin 26 can be pulled out from the inner side of the locking hole 241.

[0039] In the previous embodiment: the driving mechanism 3 includes an annular guide rail 32 fixedly installed on one side of the ground resistance measuring instrument body 1, a rotating circle 33 is rotatably arranged on the inner side of the annular guide rail 32, and a plurality of arc-shaped elastic hooks 34 are annularly arranged on the inner side of the rotating circle 33, and the arc-shaped elastic hooks 34 elastically buckle the outer hoop 27 of the first winding frame 21, and a servo motor 31 is fixedly connected to the outer surface of the annular guide rail 32, and a gearbox is connected to the output end of the servo motor 31, and the output gear of the gearbox passes through the surface of the annular guide rail 32 and is transmission-connected to the rotating circle 33, and a meshing groove cooperating with the output gear is provided on the outer surface of the rotating circle 33.

[0040] Specifically, the rotating ring 33 is driven to rotate by the servo motor 31, and the outer hoop 27 of the first winding frame 21 is clamped in the arc-shaped elastic hook 34. The first winding frame 21 is driven to rotate by the rotation of the rotating ring 33, so as to drive the first winding frame 21 and the second winding frame 22 to rotate and reel in the wire harness.

[0041] In the previous embodiment: A wire management mechanism 4 for guiding the wire harness to be wound is provided on one side of the winding component 2 in the rotation direction. The wire management mechanism 4 includes a fixed seat 41 fixedly installed on the outer surface of the annular guide rail 32. One side of the fixed seat 41 is fixedly connected to a cross bar 42 parallel to the rotating shaft of the winding component 2. A wire guiding wheel 43 is rotatably arranged on the surface of the cross bar 42. A plurality of wire guiding wheels 43 are provided and correspond to the first winding frame 21 and the second winding frame 22 one by one. A twist groove 44 is also formed on the surface of the cross bar 42. The wire guiding wheel 43 is provided with a guiding convex ball 45 that fits the inner wall of the surface of the cross bar 42. The guiding convex ball 45 is a thread groove that is arranged in the opposite direction, cross - arranged, and connected end to end. The guiding convex ball 45 moves in the twist groove 44.

[0042] Specifically, when the wire guiding wheel 43 rotates on the surface of the cross bar 42, the guiding convex ball 45 will move in a circular motion along the path formed in the twist groove 44. Further, it will cause the wire guiding wheel 43 to make a reciprocating motion on the surface of the cross bar 42. During use, by placing the wire harness to be wound on the wire guiding wheel 43, the pulled wire harness drives the wire guiding wheel 43 to rotate. When the rotating wire guiding wheel 43 makes a reciprocating motion on the surface of the cross bar 42, it will also cause the wire harness to be evenly wound on the first winding frame 21 or the second winding frame 22, thereby winding the wire harness evenly on the surfaces of the first winding frame 21 and the second winding frame 22.

[0043] Working principle: During winding, first fix one end of the wire harness on the outer surface of the first winding frame 21 or the second winding frame 22. The fixing method can be to tie this end to the bending rod 24. Then place the wire body on the upper side of the wire guiding wheel 43 and then start the servo motor 31. Drive the rotating ring 33 to rotate through the servo motor 31, drive the first winding frame 21 to rotate, and further drive the first winding frame 21 and the second winding frame 22 to rotate to wind the wire harness. The wire guiding wheel 43 drives the wire harness to make a reciprocating motion on the surfaces of the first winding frame 21 and the second winding frame 22, and wind the wire harness evenly on the surfaces of the first winding frame 21 and the second winding frame 22;

[0044] During unwinding, one way is to start the servo motor 31 to rotate in the reverse direction. As the first winding frame 21 and the second winding frame 22 rotate in the reverse direction, the wire harness is pulled out from the surfaces of the first winding frame 21 and the second winding frame 22 to complete unwinding; the other way is to first remove the limit clip 23 on one side of the second winding frame 22. At this time, without the block of the limit clip 23, the coil wound on the second winding frame 22 can be removed, thus facilitating manual unwinding. Similarly, the second winding frame 22 can also be removed on one side of the first winding frame 21 to take out the coil wound on the first winding frame 21;

[0045] As another working mode, the device can also only assemble the first winding rack 21 and the limit clip 23, and remove the second winding rack 22 to reduce the volume of the device and facilitate carrying. When winding the wire harness, after winding one circle of the wire harness, it can be taken off and tied up, and then the second wire harness can be wound. In this way, the device has great flexibility in use and is convenient to use.

[0046] It should be noted that in this article, 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 term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0047] 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 principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wire-laying device for a ground resistance measuring instrument, comprising a ground resistance measuring instrument body (1), characterized in that: A driving mechanism (3) is fixedly mounted on one side of the ground resistance measuring instrument body (1), and a winding assembly (2) for winding a wire harness is detachably connected to one side of the driving mechanism (3); The winding assembly (2) comprises a first winding frame (21) detachably connected to a driving mechanism (3); a second winding frame (22) is detachably connected to one side of the first winding frame (21); a limit clamp (23) is detachably connected to one side of the second winding frame (22); the driving mechanism (3) drives the first winding frame (21), the second winding frame (22) and the limit clamp (23) to rotate coaxially; the first winding frame (21) and the second winding frame (22) are both used for winding a wire harness; and the wound wire harness can be removed from one side of the first winding frame (21) and the second winding frame (22).

2. A wire-laying device for a ground resistance measuring instrument according to claim 1, characterized in that: A plurality of second winding frames (22) are arranged between the first winding frame (21) and the limiting clamp (23), and two adjacent second winding frames (22) are detachably connected, and the first winding frame (21) and the limiting clamp (23) are respectively connected to the head and the tail of the plurality of connected second winding frames (22).

3. The wire-laying device for a ground resistance measuring instrument according to claim 1, characterized in that: The structures of the first winding frame (21), the second winding frame (22) and the limit clamp (23) are respectively composed of a bending rod (24), a docking rod (25), an outer hoop (27) and an inner hoop (28); the diameter of the outer hoop (27) is larger than that of the inner hoop (28); the first winding frame (21) and the second winding frame (22) each comprise an outer hoop (27) and two inner hoop (28); the outer hoop (27) and the two inner hoop (28) are coaxially and equidistantly arranged in a direction from the driving mechanism (3) to the limit clamp (23); the outer surfaces of the outer hoop (27) and the inner hoop (28) are commonly connected to a plurality of annularly arranged bending rods (24); the connection between the bending rod (24) and the two inner hoop (28) is horizontally arranged.

4. A wire-laying device for a ground resistance measuring instrument according to claim 3, characterized in that: A clamping hole (241) is provided at one end of the bending rod (24) away from the outer hoop (27); a docking rod (25) corresponding to the bending rod (24) is provided in an annular manner on the inner side of the outer hoop (27) of the second winding frame (22); the bending rod (24) and the docking rod (25) are docked to form a U-shaped frame; the opening of the U-shaped frame is located on a side away from the center of the inner hoop (28); a locking pin (26) is provided at one end of the docking rod (25) close to the bending rod (24); and the locking pin (26) is plug-connected with the clamping hole (241).

5. A wire-laying device for a ground resistance measuring instrument according to claim 4, characterized in that: The limit clamp (23) comprises an outer hoop (27), and a connecting rod (25) corresponding to the bending rod (24) on the second winding frame (22) is arranged in an annular shape inside the outer hoop (27).

6. A wire-laying device for a ground resistance measuring instrument according to claim 5, characterized in that: A pair of locking balls (261) are movably embedded in the arc surface of the locking pin (26), and the locking balls (261) are symmetrically arranged on the arc surface of the locking pin (26). A spring (262) is arranged between the two locking balls (261), and the inner wall of the locking hole (241) is provided with an annular locking groove (242) that cooperates with the locking balls (261).

7. The wire-laying device for a ground resistance measuring instrument according to claim 1, characterized in that: The driving mechanism (3) comprises an annular guide rail (32) fixedly mounted on one side of the ground resistance measuring instrument body (1); a rotating circle (33) is rotatably arranged on the inner side of the annular guide rail (32); a plurality of arc-shaped elastic hooks (34) are annularly arranged on the inner side of the rotating circle (33); the arc-shaped elastic hooks (34) elastically buckle the outer hoop (27) of the first winding frame (21); a servo motor (31) is fixedly connected to the outer surface of the annular guide rail (32); an output end of the servo motor (31) is connected to a gearbox; an output gear of the gearbox penetrates the surface of the annular guide rail (32) and is transmission-connected to the rotating circle (33); and a meshing groove cooperating with the output gear is provided on the outer surface of the rotating circle (33).

8. The wire-laying device for a ground resistance measuring instrument according to claim 1, characterized in that: A wire management mechanism (4) for guiding the wire harness to be wound is arranged on one side of the rotation direction of the winding assembly (2), and the wire management mechanism (4) comprises a fixed seat (41) fixedly mounted on the outer surface of the annular guide rail (32), and one side of the fixed seat (41) is fixedly connected to a cross bar (42) parallel to the rotating shaft of the winding assembly (2), and a guide wheel (43) is rotatably arranged on the surface of the cross bar (42), and a plurality of guide wheels (43) are arranged and correspond to the first winding frame (21) and the second winding frame (22) one by one, and a twist groove (44) is also opened on the surface of the cross bar (42), and a guide convex ball (45) is arranged on the inner wall of the guide wheel (43) that is in contact with the surface of the cross bar (42), and the guide convex ball (45) is a thread groove that is opposite in direction, cross-arranged, and connected end to end, and the guide convex ball (45) moves in the twist groove (44).

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