CN115275697A

CN115275697A - Quick low-voltage emergency access device for generator car

Info

Publication number: CN115275697A
Application number: CN202211192973.0A
Authority: CN
Inventors: 何胤; 邝建波; 何道伟; 王传旭
Original assignee: Dongguan Power Supply Bureau of Guangdong Power Grid Co Ltd
Current assignee: Dongguan Power Supply Bureau of Guangdong Power Grid Co Ltd
Priority date: 2022-09-28
Filing date: 2022-09-28
Publication date: 2022-11-01
Anticipated expiration: 2042-09-28
Also published as: CN115275697B

Abstract

The invention belongs to the technical field of power generation cars, and particularly relates to a quick low-voltage emergency access device for a power generation car. The quick low-voltage emergency access device for the generator car, which is designed by the invention, realizes the quickness with the busbar of the existing power distribution cabinet by using the locking plate and the pressing plate, so that the stock public power distribution room has a quick access function of the generator car with extremely low cost.

Description

Quick low-voltage emergency access device for generator car

Technical Field

The invention belongs to the technical field of generator cars, and particularly relates to a quick low-voltage emergency access device for a generator car.

Background

With the continuous development of urban economy, the demands of users and daily production on power consumption are continuously increased, and meanwhile, the requirements of the users on power supply reliability and power quality are also continuously improved. In the operation process of power equipment, especially when bad weather such as power consumption peak and typhoon, thunderstorm, inevitable can take place the accident that can't salvage in short time and accomplish, need to adopt emergency power source to resume the power consumption of important users such as resident fast this moment, both can ensure the power supply reliability, also be the good embodiment that power supply enterprise provided high-quality service, can resume the power supply fast, be significant to people's normal production life.

At present, newly-built public power distribution rooms and residential districts are matched with quick access devices of power generation cars, and the requirements of quick access and user power supply recovery of the power generation cars in emergency can be met. However, a public power distribution room and a rack transformer with a large amount of storage do not have the condition of quick access of the power generation car, and a quick access device is additionally arranged through a planning and project-establishing or technical improvement way, so that the problems of huge improvement capital requirement, difficulty in meeting construction land, long construction period and the like exist, and the requirement of high-quality power consumption of vast resident users is difficult to meet. Although there are some quick connectors dedicated to generator cars, such quick connectors can only be used to install or replace existing utility and residential areas with associated equipment, and are not suitable for unconditional utility and residential areas.

Therefore, it is necessary to invent a quick low-voltage emergency access device for a generator car to solve the above problems.

Disclosure of Invention

Aiming at the problems, the invention provides a quick low-voltage emergency access device of a generator car, which aims to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a quick emergent access device of low pressure of generator car, includes the high-speed connector, the one end of high-speed connector is equipped with the go-between, the top of go-between is run through and has been seted up the breach, be equipped with the wiring stick between go-between and the high-speed connector, the one end and the high-speed connector fixed connection of wiring stick, the other end of wiring stick runs through the side of pegging graft at the go-between, and the wiring stick is located the intra-annular one end fixedly connected with connecting block of connecting, the inboard of go-between is equipped with locking device.

Furthermore, the locking device comprises a cylindrical locking plate, the locking plate is rotatably installed on the inner side of the connecting ring, the outer side of the locking plate is tightly attached to the connecting block, a rectangular locking hole is formed in the circle center of the locking plate in a penetrating mode along the front-back direction, a socket is formed in the corner, far away from the wire connecting rod, of the locking hole in a penetrating mode, the top, far away from one side of the wire connecting rod, of the socket is lower than the top of the other side of the socket in height, a pressing plate is arranged on one side, far away from the wire connecting rod, of the locking plate in a perpendicular rotating mode and connected with a screw rod, free end threads of the screw rod are connected in a penetrating mode on the corresponding side of the locking plate in a penetrating mode, a through hole is formed in the circumferential direction of the connecting ring in the position, opposite to the screw rod, of the connecting ring, through holes are formed in the free end of the screw rod in the circumferential direction of the connecting ring, a plurality of straight rods are fixedly connected to the pressing plate in a perpendicular fixing plate in a penetrating mode and slidably inserted mode on the hole wall, nuts and fixing plates are sleeved on the partial threads, the outer portion, the fixing plate is closer to the connecting ring than the nut, one side, two arc-shaped limiting strips, the fixing plate is symmetrically and the fixing plate is fixedly connected to the connecting ring in the same as the radian of the through holes in the radian of the connecting ring.

Furthermore, one side of the locking hole, which is far away from the pressure plate, is slidably inserted with a plurality of movable rods, and a first spring is fixedly connected between one end of each movable rod, which is positioned in the locking plate, and the locking plate.

Furthermore, the both sides of lockplate have all seted up the spout along vertical direction, the spout is located the bottom position in locking hole, slidable mounting has the slider in the spout, two the equal fixedly connected with fixture block in one side that the slider leaves mutually, the top and the bottom of fixture block are equipped with first magnetic path and second magnetic path respectively, the top fixed connection of first magnetic path and spout, one side fixed connection that second magnetic path and go-between correspond, and the top of second magnetic path is upwards outstanding, the bottom of fixture block seted up with second magnetic path top assorted draw-in groove.

Furthermore, arc-shaped jacks are formed in two sides of the notch, arc-shaped plates are inserted into the jacks close to one side of the wire connecting rod in a sliding mode, connecting holes are formed in the hole walls of the bottoms of the jacks in a penetrating mode, connecting strips are fixedly connected to the bottoms of the arc-shaped plates, and the connecting strips are fixedly connected with the top of the locking plate.

Furthermore, the arc plate is not arranged in the jack, two arc-shaped limiting rods are inserted into the slot in a sliding mode, the part, located on one side, away from the jack opening, of each limiting rod is sleeved with a second spring, and two limiting holes matched with the limiting rods are formed in one side, close to the slot, of the arc plate in a penetrating mode.

Furthermore, the top of the pressing plate is fixedly connected with a guide block, the top of the guide block is arranged in an inclined plane, and the inclined plane at the top of the guide block and one side, far away from the connecting plate, of the notch are located in the same plane.

Furthermore, a plurality of the movable rods are uniformly distributed at positions close to the top of the pressure plate, and the movable rods can completely enter the locking plate.

Furthermore, the length of the arc-shaped plate is larger than the width of the notch, and the arc-shaped plate and the connecting ring are made of insulating materials.

The invention has the technical effects and advantages that:

1. the quick low-voltage emergency access device for the generator car, which is designed by the invention, realizes quick access with the busbar of the existing power distribution cabinet by using the locking plate and the pressing plate, so that a stock public power distribution room can have a quick access function for the generator car with extremely low cost, in addition, the connecting ring is arranged outside the locking plate, so that the purpose of improving the reliability of connection between the busbar and the locking plate is achieved, and the device can be detached when not used, so that the cabinet door can be normally closed when the power supply of the generator car is not needed, and the working efficiency and the safety are both considered;

2. after the cable is connected with the quick connector, the cable can be driven by a worker to deflect downwards along with the connection ring by taking the circle center of the connection ring as an axis under the action of gravity along with the cable laid down by the worker, and the arc-shaped plate can gradually move out of the jack in the initial state and be inserted into another jack along with the deflection of the connection ring, so that a gap is sealed, the connection reliability of the locking plate and the busbar is guaranteed, abnormal discharge at the position of the gap is avoided, and the use safety of the generator car is guaranteed;

3. in the process that the arc-shaped plate is rotated out of the jack, when the arc-shaped plate is contacted with the strip plate, along with the continuous rotation of the connecting ring, the limiting rod can be gradually inserted into the limiting hole in the arc-shaped plate under the driving of the connecting ring, and the strip plate can gradually compress the second spring under the extrusion of the arc-shaped plate, so that the second spring is in a partial compression state, and further when a cable of the power generation vehicle is blown separately or touched, the cable can continuously deflect downwards by taking the circle center of the connecting ring as an axis, so that the second spring is further compressed, and the force applied to the cable is converted into the elastic potential energy of the second spring, thereby avoiding the unstable connection between the cable and a busbar due to the shaking of the cable;

4. because female width of arranging is different, after female arranging is inserted in the locking, make female bottom of arranging and the bottom pore wall of locking hole paste tightly earlier, and female first half of arranging then can overlap with the movable rod place region this moment, when making the screw rod promote clamp plate and female contact of arranging through twisting the nut, along with the extrusion of clamp plate to female arranging, female arranging can press gradually rather than the first spring of relative movable rod compression and to lockplate inside removal, and not can keep off at female top of arranging with female relative movable rod, thereby restrict female headspace, and then guarantee lockplate and female back of arranging the connection together, female arranging can not take place relative slip with the lockplate, thereby guarantee to arrange stable electric connection between female and the lockplate.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is an overall perspective view of the present invention;

figure 2 is a perspective view of the patch panel, attachment ring and locking arrangement of the present invention;

FIG. 3 is a perspective view of a portion of the locking device of the present invention;

FIG. 4 is a main sectional view of the attachment ring in the present invention;

FIG. 5 is an enlarged view of portion A of FIG. 4 according to the present invention;

fig. 6 is a partial cross-sectional view of a locking plate in the present invention.

In the figure: 1. a quick connector; 2. a connecting ring; 3. a wire connecting rod; 4. connecting blocks; 5. a locking device; 51. a locking plate; 52. pressing a plate; 53. a screw; 54. a straight rod; 55. a nut; 56. a fixing plate; 57. a limiting strip; 6. a movable rod; 7. a first spring; 8. a slider; 9. a clamping block; 10. a first magnetic block; 11. a second magnetic block; 12. an arc-shaped plate; 13. a connecting strip; 14. laths; 15. a limiting rod; 16. a second spring; 17. a limiting hole; 18. and a guide block.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a quick low-voltage emergency access device of a generator car as shown in figures 1-6, which comprises a quick connector 1, wherein the model of the quick connector 1 is 630A, one end of the quick connector 1 is provided with a connecting ring 2, the top of the connecting ring 2 is provided with a notch in a penetrating way, a wiring rod 3 is arranged between the connecting ring 2 and the quick connector 1, one end of the wiring rod 3 is fixedly connected with the quick connector 1, the other end of the wiring rod 3 is inserted on the side surface of the connecting ring 2 in a penetrating way, one end of the wiring rod 3 positioned in the connecting ring 2 is fixedly connected with a connecting block 4, the inner side of the connecting ring 2 is provided with a locking device 5, the locking device 5 comprises a cylindrical locking plate 51, the locking plate 51 is rotatably arranged on the inner side of the connecting ring 2, the outer side of the locking plate 51 is tightly attached to the connecting block 4, the center of the locking plate 51 is provided with a rectangular locking hole in a penetrating way along the front-back direction, a socket is arranged at the corner of the top of the locking hole far away from the wire connecting rod 3 in a penetrating manner, the top of one side of the socket far away from the wire connecting rod 3 is lower than the top of the other side of the socket, a pressing plate 52 is arranged at one side of the locking hole far away from the wire connecting rod 3, a screw 53 is vertically and rotatably connected to one side of the pressing plate 52 far away from the wire connecting rod 3, the free end thread of the screw 53 is inserted into one side corresponding to the locking plate 51 in a penetrating manner, a through hole is arranged at the position of the connecting ring 2 opposite to the screw 53 along the circumferential direction of the connecting ring 2, the free end of the screw 53 penetrates through the through hole, a plurality of straight rods 54 are vertically and fixedly connected to one side of the pressing plate 52 far away from the wire connecting rod 3, the straight rods 54 are inserted into the hole wall of the corresponding side of the locking hole in a sliding manner, and a nut 55 and a fixing plate 56 are sleeved on the partial thread of the screw 53 outside the connecting ring 2, the fixing plate 56 is closer to the connecting ring 2 than the nut 55, two arc-shaped limiting strips 57 are symmetrically and fixedly connected to one side of the fixing plate 56 close to the connecting ring 2, the radian of each limiting strip 57 is the same as that of the through hole, the two limiting strips 57 are respectively slidably mounted on the hole walls on the front side and the rear side of the through hole, the top of the pressing plate 52 is fixedly connected with the guide block 18, the top of the guide block 18 is arranged in an inclined plane, and the inclined plane at the top of the guide block 18 and one side of the notch far away from the connecting plate are located in the same plane;

when the quick connector is used, the gap of the connecting ring 2 is kept opposite to the socket of the locking plate 51, the connecting ring 2 is moved to the bottom of a busbar in the power distribution cabinet, the gap of the connecting ring 2 is kept opposite to the busbar while the quick connector 1 is ensured to face the outer side of the cabinet body, and the connecting ring 2, the locking plate 51 and the busbar are clamped together from bottom to top;

then, the nut 55 is screwed by using a wrench, so that the screw 53 compresses the wall of the side, close to the terminal bar 3, of the busbar and the locking hole under the action of the nut 55, thereby completing the electrical connection between the busbar and the locking plate 51, and then the cable of the generator car is spliced with the quick connector 1, and as the quick connector 1 is electrically connected with the locking plate 51 through the terminal bar 3 and the connecting block 4, the electrical connection between the cable and the busbar can be realized after the quick connector 1 is connected with the cable;

as shown in fig. 6, a plurality of movable rods 6 are inserted through the side of the locking hole far from the pressing plate 52 in a sliding manner, a first spring 7 is fixedly connected between one end of each movable rod 6 located in the locking plate 51 and the locking plate 51, the plurality of movable rods 6 are uniformly distributed at positions close to the top of the pressing plate 52, and the movable rods 6 can completely enter the locking plate 51;

because the widths of the busbars are different, when the busbars are inserted into the lock, the bottoms of the busbars are tightly attached to the wall of the bottom hole of the lock hole, the upper half parts of the busbars are overlapped with the area where the movable rods 6 are located, when the screw 53 pushes the pressing plate 52 to be in contact with the busbars by screwing the nut 55, the busbars can gradually press the movable rods 6 opposite to the busbars to compress the first springs 7 and move towards the interior of the lock plate 51 along with the extrusion of the pressing plate 52 on the busbars, the movable rods 6 not opposite to the busbars can be blocked at the tops of the busbars, so that the top space of the busbars is limited, and further, after the busbars 51 are connected with the busbars, the busbars cannot slide relative to the lock plate 51, so that the stable electrical connection between the busbars and the lock plate 51 is ensured;

after the cable of the generator car is connected with the quick connector 1, the cable is laid down, the cable can drive the connecting ring 2 to deflect downwards by taking the circle center of the connecting ring 2 as an axis under the action of gravity, and along with the deflection of the connecting ring 2, a gap in the connecting ring 2 can be staggered with a socket in the locking plate 51, so that the busbar is stably limited in a locking hole of the locking plate 51, and the reliability of connection between the busbar and the locking plate 51 is improved.

As shown in fig. 1, 2 and 6, sliding grooves are formed in two sides of the locking plate 51 along the vertical direction, the sliding grooves are located at the bottom of the locking hole, sliding blocks 8 are slidably mounted in the sliding grooves, a clamping block 9 is fixedly connected to each of two sides, away from each other, of each of the two sliding blocks 8, a first magnetic block 10 and a second magnetic block 11 are respectively arranged at the top and the bottom of each clamping block 9, the first magnetic block 10 is fixedly connected with the top of the sliding groove, the second magnetic block 11 is fixedly connected with one side, corresponding to the connecting ring 2, of the connecting ring 2, the top of the second magnetic block 11 protrudes upwards, and a clamping groove matched with the top of the second magnetic block 11 is formed in the bottom of each clamping block 9;

in an initial state, the fixture block 9 and the second magnetic block 11 can be adsorbed together, so that the connecting ring 2 and the locking plate 51 are locked, the gap of the connecting ring 2 can be kept opposite to the socket of the locking plate 51, and the busbar can be conveniently and smoothly inserted into the locking hole in the locking plate 51;

after female arranging and lockplate 51 are connected, upwards promote fixture block 9, make it along spout upward movement and adsorb together with first magnetic path 10, because lockplate 51 and go-between 2 no longer are locked by fixture block 9 this moment, after the cable of generating car is connected with quick connector 1 completion, along with the cable is put down, the cable can use the centre of a circle of go-between 2 to drive go-between 2 and deflect downwards together as the axle under the effect of gravity, and along with the deflection of go-between 2, breach on the go-between 2 can stagger with the socket on the lockplate 51, thereby arrange stable restriction at lockplate 51's locking hole with female, improve female reliability of being connected with lockplate 51.

As shown in fig. 4 and 5, arc-shaped insertion holes are formed in both sides of the notch, wherein an arc-shaped plate 12 is inserted in the insertion hole close to one side of the wire connecting rod 3 in a sliding manner, connection holes are formed through the hole walls of the bottoms of the two insertion holes, a connection strip 13 is fixedly connected to the bottom of the arc-shaped plate 12, the connection strip 13 is fixedly connected to the top of the locking plate 51, a slat 14 is arranged in the insertion hole without the arc-shaped plate 12, two arc-shaped limiting rods 15 are inserted in the slat 14 in a sliding manner, a second spring 16 is sleeved on the part, located on one side of the slat 14 far away from the opening of the insertion hole, of each limiting rod 15, two limiting holes 17 matched with the limiting rods 15 are formed through one side of the arc-shaped plate 12 close to the slat 14 in a sliding manner, the length of the arc-shaped plate 12 is greater than the width of the notch, and the arc-shaped plate 12 and the connection ring 2 are both made of insulating materials;

after a busbar in a power distribution room is clamped under the matching action of the pressing plate 52 and the locking plate 51, the clamping block 9 slides upwards along the sliding groove, the clamping block 9 and the first magnetic block 10 are adsorbed together, then a worker holds the quick connector 1 with one hand and inserts a cable of the generator car into the quick connector 1 with the other hand, after connection is finished, the cable can be put down along with the worker, the cable can drive the connecting ring 2 to deflect downwards along with the center of circle of the connecting ring 2 as an axis under the action of gravity, and the arc-shaped plate 12 can gradually move out of the jack in the initial state and be inserted into the other jack along with deflection of the connecting ring 2, so that a gap is sealed, the reliability of connection between the locking plate 51 and the busbar is ensured, abnormal discharge at the gap position is avoided, and the use safety of the generator car is ensured;

in-process at arc 12 roll-out jack, when arc 12 and slat 14 contact, along with the continuation rotation of go-between 2, gag lever post 15 can insert gradually in the spacing hole 17 on the arc 12 under the drive of go-between 2, and slat 14 then can compress second spring 16 gradually under the extrusion of arc 12, thereby make second spring 16 be in partial compression state, and then when the cable of power-generating cars is blown or is touch by dividing, the cable can use the centre of a circle of go-between 2 to continue deflecting downwards as the axle, thereby further compress second spring 16, and then turn into second spring 16's elasticity potential energy with the power that the cable received, and then avoid rocking because of the cable and cause the cable unstable with female connection of arranging.

Although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a quick low pressure emergency access device of generator car, includes quick connector (1), its characterized in that: the one end of high-speed joint ware (1) is equipped with go-between (2), the top of go-between (2) is run through and has been seted up the breach, be equipped with wiring stick (3) between go-between (2) and high-speed joint ware (1), the one end and high-speed joint ware (1) fixed connection of wiring stick (3), the other end of wiring stick (3) runs through the side of pegging graft at go-between (2), and one end fixedly connected with connecting block (4) that wiring stick (3) are located go-between (2), the inboard of go-between (2) is equipped with locking device (5).

2. A generator car quick low-voltage emergency access device according to claim 1, wherein: the locking device (5) comprises a cylindrical locking plate (51), the locking plate (51) is rotatably installed on the inner side of the connecting ring (2), the outer side of the locking plate (51) is attached to the connecting block (4), a rectangular locking hole penetrates through the circle center of the locking plate (51) in the front-back direction, a socket penetrates through the corner of the top of the locking hole far away from the wire connecting rod (3), the top of one side, far away from the wire connecting rod (3), of the socket is lower than the top of the other side of the socket in height, a pressing plate (52) is arranged on one side, far away from the wire connecting rod (3), of the pressing plate (52), a screw rod (53) is vertically and rotatably connected with one side, far away from the wire connecting rod (3), of the free end of the screw rod (53) penetrates through the corresponding side of the locking plate (51), a through hole is formed in the circumferential direction of the connecting ring (2) and the screw rod (53) opposite to the screw rod (2), the free end of the screw rod (53) penetrates through the through hole, a plurality of straight rods (54) are vertically and fixedly connected with the straight rod (54) in a threaded connection with the nut (55), and the fixing plate (55) is located on the side, the connecting ring (54) which is slidably connected with the nut (55) close to the nut (55), and one side of the fixing plate (56) close to the connecting ring (2) is symmetrically and fixedly connected with two arc-shaped limiting strips (57), the radian of each limiting strip (57) is the same as that of the through hole, and the two limiting strips (57) are respectively and slidably mounted on the hole walls of the front side and the rear side of the through hole.

3. A generator car quick low-voltage emergency access device according to claim 2, wherein: one side of the locking hole, which is far away from the pressure plate (52), is slidably inserted with a plurality of movable rods (6), and a first spring (7) is fixedly connected between one end of each movable rod (6), which is positioned in the locking plate (51), and the locking plate (51).

4. A quick low-voltage emergency access device for a generator car as claimed in claim 3, characterized in that: the locking plate is characterized in that sliding grooves are formed in two sides of the locking plate (51) along the vertical direction and are located at the bottom of the locking hole, sliding blocks (8) are arranged in the sliding grooves in a sliding mode, two sliding blocks (8) are fixedly connected with clamping blocks (9) on the side where the sliding blocks (8) are separated from each other, a first magnetic block (10) and a second magnetic block (11) are arranged at the top and the bottom of each clamping block (9) respectively, the first magnetic block (10) is fixedly connected with the top of the sliding grooves, the second magnetic block (11) is fixedly connected with one side corresponding to the connecting ring (2), the top of the second magnetic block (11) protrudes upwards, and a clamping groove matched with the top of the second magnetic block (11) is formed in the bottom of each clamping block (9).

5. A quick low-voltage emergency access device for a generator car as claimed in claim 4, characterized in that: arc-shaped jacks are formed in two sides of the notch, arc-shaped plates (12) are inserted in the jacks close to one sides of the wire connecting rods (3) in a sliding mode, connecting holes are formed in the hole walls of the bottoms of the two jacks in a penetrating mode, connecting strips (13) are fixedly connected to the bottoms of the arc-shaped plates (12), and the connecting strips (13) are fixedly connected with the tops of the locking plates (51).

6. A quick low-voltage emergency access device for a generator car as claimed in claim 5, characterized in that: the novel socket is characterized in that a strip plate (14) is arranged in the jack and is not provided with an arc plate (12), two arc-shaped limiting rods (15) are arranged on the strip plate (14) in a sliding penetrating and inserting mode, a second spring (16) is sleeved on the portion, located on one side, far away from the jack opening, of the strip plate (14), of each limiting rod (15), and two limiting holes (17) matched with the corresponding limiting rods (15) are arranged on one side, close to the strip plate (14), of the arc plate (12) in a penetrating mode.

7. A quick low-voltage emergency access device for a generator car as claimed in claim 3, characterized in that: the top of the pressing plate (52) is fixedly connected with a guide block (18), the top of the guide block (18) is arranged in an inclined plane, and the inclined plane at the top of the guide block (18) and one side, far away from the connecting plate, of the notch are located in the same plane.

8. A quick low-voltage emergency access device for a generator car as claimed in claim 7, characterized in that: the movable rods (6) are uniformly distributed at a position close to the top of the pressure plate (52), and the movable rods (6) can completely enter the locking plate (51).

9. A generator car quick low-voltage emergency access device according to claim 6, wherein: the length of the arc-shaped plate (12) is larger than the width of the notch, and the arc-shaped plate (12) and the connecting ring (2) are made of insulating materials.