Radiating unit

Abstract

The utility model relates to the technical field of communication, in particular to a radiating element, which comprises a balun seat, a radiating element, a radiating element, a radiating element and a radiating element, and is characterized in that the balun seat comprises an annular base and four balun arms; the number of the oscillator arms is four, and the four oscillator arms are connected to the sides, away from the annular base, of the four balun arms in a one-to-one correspondence mode; a feed assembly, wherein the feed assembly comprises two feed ends and four matching cables; the number of the connecting assemblies is four, each connecting assembly comprises an oscillator buckle and two buckle bases, the two ends of the oscillator buckle are connected with the two buckle bases in a clamped mode respectively, and the ends, away from each other, of the two buckle bases are connected with the close ends of the two adjacent oscillator arms in a one-to-one correspondence mode respectively. According to the radiation unit disclosed by the invention, the occupation of a height space is reduced, the overall stability of the radiation unit is improved, the radiation performance of the radiation unit is optimized, and the quality and efficiency of signal transmission are improved.

Description

Technical Field

[0001] This utility model relates to the field of communication technology, and in particular to a radiating unit. Background Technology

[0002] Radiating elements, commonly known as dipoles, come in various forms. Currently, the most commonly used radiating element structures in the base station antenna industry include: bowl-shaped radiating elements, half-wave dipole radiating elements, and folded radiating elements. The performance of the radiating element directly determines important antenna parameters such as gain, half-power beamwidth, front-to-back ratio, and cross-polarization ratio. Among these, the bowl-shaped radiating element uses a dipole-opposite configuration. By placing one pair of dipoles in one polarization direction and another pair in a direction orthogonal to it, a dual-polarization radiating element is formed. Since a pair of dipoles forms a small binary array, the bowl-shaped radiating element has the advantages of high gain and narrow beam. However, the dipole arms of the bowl-shaped radiating element are relatively slender, resulting in poor stability when connected via dipole clips, and the clips can easily damage the dipole arms during connection.

[0003] It is evident that existing technologies still need improvement and enhancement. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a radiation unit to solve the problem of poor stability of existing bowl-shaped oscillators.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A radiating unit, comprising:

[0007] The balun base includes an annular base and four balun arms. The four balun arms are all straight structures. One end of each of the four balun arms is connected to the periphery of the annular base. The four balun arms are all inclined toward one side of the top of the annular base.

[0008] The vibrating arm comprises four arms, each of which is connected to one of the four balun arms on the side away from the annular base.

[0009] The power supply assembly includes two power supply terminals and four matching cables. The four matching cables are respectively clamped on the four balun arms. One end of each of the four matching cables is electrically connected to one of the four oscillator arms. The two power supply terminals are respectively passed through the annular base. The other ends of any two matching cables spaced apart are electrically connected to any one of the power supply terminals. The other ends of the other two matching cables are electrically connected to the other power supply terminal.

[0010] Connecting components, there are four of the connecting components, each of the connecting components respectively includes an oscillator buckle and two buckle seats, both ends of the oscillator buckle are respectively clamped with the two buckle seats, the two buckle seats are symmetrically arranged along the midline of the oscillator buckle, and the far ends of the two buckle seats are respectively correspondingly connected to the adjacent ends of the two oscillator arms.

[0011] For a radiation unit as described above, each of the buckle seats is respectively provided with a through hole and a radiation surface, the through hole penetrates along the height direction of the buckle seat, the radiation surface is arranged in the through hole, and the radiation surface is flush with the oscillator arm.

[0012] For a radiation unit as described above, each of the buckle seats respectively includes a sleeve, a U-shaped part and a clamping groove, the open end of the U-shaped part is connected to the outside of the sleeve, a through hole is formed between the U-shaped part and the sleeve, the end of the U-shaped part far from the opening is connected to the oscillator arm, the clamping groove is arranged on the U-shaped part, the oscillator buckle includes a concave-shaped kit, a stop block, two insertion blocks and two first buckles, the stop block is arranged in the middle on the inner side of the concave-shaped kit, the two sleeves are respectively abutted on both sides of the stop block, the two insertion blocks are arranged on both sides of the concave-shaped kit relative to the stop block, the two insertion blocks are respectively inserted into the two sleeves in a one-to-one correspondence, the two first buckles are respectively arranged on both sides of the concave-shaped kit, and the two first buckles are respectively in one-to-one correspondence and clamped with the clamping grooves on the two sleeves.

[0013] For a radiation unit as described above, the cross-sectional shape of the sleeve is in a shape of a Chinese character 'hui', and both the inner and outer sides of the sleeve are provided with rounded corners.

[0014] For a radiation unit as described above, each of the oscillator arms respectively includes a first radiation arm and a second radiation arm, and the first radiation arm and the second radiation arm are respectively symmetrically arranged on both sides of any one of the balun arms.

[0015] For a radiation unit as described above, each of the balun arms respectively includes a first balun arm and a second balun arm, one ends of the first balun arm and the second balun arm are respectively connected to the annular base, the first radiation arm is connected to the other end of the first balun arm, the second radiation arm is connected to the other end of the second balun arm, the radiation unit further includes four reinforcing sleeves, the four reinforcing sleeves are respectively arranged in one-to-one correspondence with the four balun arms, and both ends of each of the reinforcing sleeves are respectively connected to the first balun arm and the second balun arm of the same balun arm.

[0016] As described above, in a type of radiating unit, each of the reinforcing clips includes a clip assembly, a spacer block, two second clips, two third clips, and two limiting posts. The clip assembly is snapped onto the balun arm. The spacer block is located on the middle of the inner side of the clip assembly, with its two sides abutting against the first and second balun arms, respectively. The two second clips are located on both sides of one end of the clip assembly and are snapped onto both sides of the first radiating arm. The two third clips are located on both sides of the other end of the clip assembly and are snapped onto both sides of the second radiating arm. The two limiting posts are located at both ends of the inner side of the clip assembly. The first and second radiating arms are each provided with insertion holes, and the two limiting posts are inserted into the two insertion holes one by one.

[0017] In one type of radiating unit as described above, the two first balun arms on the left side of the annular base are respectively provided with first grooves, and the two matching cables on the left side of the annular base are respectively locked in the two first grooves. One end of the two matching cables on the left side of the annular base is respectively electrically connected to the two second balun arms on the left side of the annular base. The two second balun arms on the right side of the annular base are respectively provided with second grooves, and the two matching cables on the right side of the annular base are respectively locked in the two second grooves. One end of the two matching cables on the right side of the annular base is respectively electrically connected to the two first balun arms on the right side of the annular base.

[0018] As described above, the radiation unit further includes a connecting base, which includes a base plate, four limiting blocks, four fourth buckles, and at least two insertion buckles. The base plate abuts against the bottom of the annular base. The four limiting blocks are respectively arranged around the outer side of the base plate and are respectively located on the side of the base plate facing the annular base. The four fourth buckles are respectively located on the side of the four limiting blocks facing the annular base and are respectively engaged with the annular base. At least two insertion buckles are respectively located on the side of the base plate facing away from the annular base.

[0019] Beneficial effects:

[0020] This utility model discloses a radiating unit, including a balun base, vibrating arms, a feeding assembly, and a connecting assembly. The balun base includes an annular base and four balun arms, wherein the four balun arms are arranged around the outer side of the annular base to form a frustum-shaped bowl vibrator. Compared with the existing arc-shaped balun arms, this design ensures that the size of the radiating vibrator remains unchanged while reducing the straightened length of each balun arm and the height space occupied. The vibrating arms include four, each connected to a side of the four balun arms away from the annular base. The feeding assembly includes two feeding terminals and four matching cables. The four matching cables are respectively clamped onto the four balun arms and electrically connected to each of the four vibrating arms. The two feeding terminals are... The matching cables, which are not threaded onto the annular base, are electrically connected at the other ends of any two spaced-apart cables to either of the feed terminals, and at the other ends of the other two matching cables to the other feed terminal, thus forming a cross-polarization. These cables are then connected to an external cable via the two feed terminals. The connecting assembly comprises four components, each including a vibrator latch and two latch seats. These components create a stable connection between the vibrator arms, enhancing the overall stability of the radiation unit and ensuring the consistency and stability of the radiated signal. This radiation unit disclosed in this application reduces the space occupied by the height, improves the overall stability of the radiation unit, optimizes the radiation performance of the radiation unit, and improves the quality and efficiency of signal transmission. Attached Figure Description

[0021] Figure 1 A schematic diagram of the structure of the radiating unit provided by this utility model;

[0022] Figure 2 A top view of the radiating unit provided by this utility model;

[0023] Figure 3 Exploded view of the radiation unit provided by this utility model;

[0024] Figure 4 An exploded view of the radiating unit provided by this utility model from another angle;

[0025] Reference numerals: 1. Balun seat; 11. Annular base; 12. Balun arm; 121. First balun arm; 122. Second balun arm; 13. First groove; 14. Second groove; 2. Vibrator arm; 21. First radiating arm; 22. Second radiating arm; 23. Plug-in hole; 3. Power supply assembly; 31. Power supply end; 32. Matching cable; 4. Connecting assembly; 41. Vibrator clip; 411. Concave kit; 412. Stop; 413. Insertion block; 414. First buckle; 42. Buckle seat; 421. Through hole; 422. Radial surface; 423. Sleeve; 424. U-shaped part; 425. Slot; 426. Rounded corner; 5. Reinforcing sleeve; 51. Buckle set; 52. Partition block; 53. Second buckle; 54. Third buckle; 55. Limiting post; 6. Connecting base; 61. Base plate; 62. Limiting block; 63. Fourth buckle; 64. Insertion buckle. Detailed Implementation

[0026] This utility model provides a radiation unit. To make the purpose, technical solution and effects of this utility model clearer and more explicit, the following describes this utility model in further detail with reference to the accompanying drawings and embodiments.

[0027] In the description of this utility model, it should be understood that the terms "top" and other terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and should not be construed as limiting this utility model; in addition, the terms "installation" and "connection" should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] like Figure 1-4 As shown in the figure, an embodiment of this application proposes a radiating element, including:

[0029] The balun seat 1 includes an annular base 11 and four balun arms 12. The four balun arms 12 are all straight structures. One end of each of the four balun arms 12 is connected to the periphery of the annular base 11. The four balun arms 12 are all inclined toward one side of the top of the annular base 11.

[0030] The vibrating arm 2 comprises four arms, each of which is connected to one of the four balun arms 12 on the side away from the annular base 11.

[0031] The power supply assembly 3 includes two power supply terminals 31 and four matching cables 32. The four matching cables 32 are respectively clamped on the four balun arms 12. One end of each of the four matching cables 32 is electrically connected to one of the four vibrating arms 2. The two power supply terminals 31 are respectively passed through the annular base 11. The other end of any two matching cables 32, which are spaced apart, is electrically connected to any one of the power supply terminals 31. The other ends of the other two matching cables 32 are electrically connected to the other power supply terminal 31.

[0032] The connecting component 4 includes four components. Each connecting component 4 includes a vibrator buckle 41 and two buckle seats 42. The two ends of the vibrator buckle 41 are respectively engaged with the two buckle seats 42. The two buckle seats 42 are symmetrically arranged along the center line of the vibrator buckle 41. The far end of the two buckle seats 42 is respectively connected to the adjacent end of the two adjacent vibrator arms 2.

[0033] This utility model discloses a radiating unit, including a balun base 1, vibrator arms 2, a power supply assembly 3, and a connecting assembly 4. The balun base 1 includes an annular base 11 and four balun arms 12, wherein the four balun arms 12 are arranged around the outer side of the annular base 11 to form a frustum-shaped bowl-shaped vibrator. Compared with the existing arc-shaped balun arms, this design ensures that the size of the radiating vibrator remains unchanged while reducing the straightened length of each balun arm and the height space occupied. The vibrator arms 2 include four, each connected to one side of the four balun arms 12 away from the annular base 11. The power supply assembly 3 includes two power supply terminals 31 and four matching cables 32, each clamped onto one of the four balun arms 12 and electrically connected to one of the four vibrator arms 2. The feed terminals 31 are respectively installed on the annular base 11. The other ends of any two matching cables 32, which are spaced apart, are electrically connected to any one of the feed terminals 31, and the other ends of the other two matching cables 32 are electrically connected to the other feed terminal 31, thus forming a cross-polarization. The cables are connected to an external cable through the two feed terminals. The connection components 4 include four components, each of which includes a vibrator latch 41 and two latch seats 42. The connection components enable a stable connection between the vibrator arms, enhancing the overall stability of the radiation unit and ensuring the consistency and stability of the radiated signal. The radiation unit disclosed in this application reduces the occupation of vertical space, improves the overall stability of the radiation unit, optimizes the radiation performance of the radiation unit, and improves the quality and efficiency of signal transmission.

[0034] Each of the latching seats 42 is provided with a through hole 421 and a radiating surface 422. The through hole 421 extends along the height direction of the latching seat 42, and the radiating surface 422 is disposed in the through hole 421. The radiating surface 422 is flush with the vibrator arm 2. The flushness of the radiating surface 422 with the vibrator arm 2 can reduce radiation interference, improve radiation efficiency, and avoid signal loss due to structural differences. Furthermore, the through hole 421 on the latching seat 42 can provide better support for the radiating surface 422.

[0035] Each of the aforementioned latching seats 42 includes a sleeve 423, a U-shaped component 424, and a latching groove 425. One open end of the U-shaped component 424 is connected to the outer side of the sleeve 423, and a through hole 421 is formed between the U-shaped component 424 and the sleeve 423. The end of the U-shaped component 424 away from the opening is connected to the vibrator arm 2. The latching groove 425 is provided on the U-shaped component 424. The vibrator latch 41 includes a concave fitting 411, a stop block 412, two insertion blocks 413, and two first latches 414. The stop block 412 is provided on the middle of the inner side of the concave fitting 411. The two sleeves 423 respectively abut against the two sides of the stop block 412. The two insertion blocks 413 are provided on the two sides of the inner side of the concave fitting 411 opposite to the stop block 412. Two insertion blocks 413 are respectively inserted into two sleeves 423. Two first buckles 414 are respectively provided on both sides of the concave kit 411. The two first buckles 414 are respectively engaged with the slots 425 on the two sleeves 423. Through the insertion of the insertion blocks 413 and the sleeves 423, and the engagement of the first buckles 414 and the slots 425, the double engagement improves the stability of the structural connection. The sleeves 423 have a U-shaped cross-section and rounded corners 426 on both the inner and outer sides. The square structure of the sleeves 423 helps to optimize the standing wave characteristics. The rounded corners 426 reduce the generation of reflected waves and lower the standing wave ratio, thereby improving the radiation efficiency of the radiation unit.

[0036] Each of the said vibrating arms 2 includes a first radiating arm 21 and a second radiating arm 22. The first radiating arm 21 and the second radiating arm 22 are symmetrically arranged on both sides of any of the said balun arms 12. That is, the first radiating arm 21 and the second radiating arm 22 of two adjacent vibrating arms 2 are arranged adjacently along the straight line direction of the two vibrating arms 2. This can improve the antenna front-to-back ratio, cross-polarization and other performance, while reducing the size of the radiating element and achieving miniaturization.

[0037] Each of the balun arms 12 includes a first balun arm 121 and a second balun arm 122. One end of the first balun arm 121 and the second balun arm 122 are respectively connected to the annular base 11. The first radiating arm 21 is connected to the other end of the first balun arm 121, and the second radiating arm 22 is connected to the other end of the second balun arm 122. The radiating unit also includes four reinforcing sleeves 5, which are respectively arranged one-to-one with the four balun arms 12. The two ends of each reinforcing sleeve 5 are respectively connected to the first balun arm 121 and the second balun arm 122 of the same balun arm 12, effectively improving the oscillation effect of the oscillator arm 2, and achieving the requirement of lightweighting of the radiating unit through this arrangement. Each reinforcing sleeve 5 includes a clip 51, a spacer block 52, two second clips 53, two third clips 54, and two... A limiting post 55 is provided. The card assembly 51 is snapped onto the balun arm 12. The partition block 52 is located on the middle of the inner side of the card assembly 51. The two sides of the partition block 52 abut against the first balun arm 121 and the second balun arm 122, respectively. Two second buckles 53 are respectively located on both sides of one end of the card assembly 51 and are respectively snapped onto both sides of the first radiating arm 21. Two third buckles 54 are respectively located on both sides of the other end of the card assembly 51 and are respectively snapped onto both sides of the second radiating arm 22. Two limiting posts 55 are respectively located on both ends of the inner side of the card assembly 51. The first radiating arm 21 and the second radiating arm 22 are respectively provided with insertion holes 23. The two limiting posts 55 are respectively inserted into the two insertion holes 23 one by one to strengthen the stability of the radiating unit structure.

[0038] The two first balun arms 121 on the left side of the annular base 11 are respectively provided with first grooves 13. The two matching cables 32 on the left side of the annular base 11 are respectively locked onto the two first grooves 13. One end of the two matching cables 32 on the left side of the annular base 11 is respectively electrically connected to the two second balun arms 122 on the left side of the annular base 11. The two second balun arms 122 on the right side of the annular base 11 are respectively provided with second grooves 14. The two matching cables 32 on the right side of the annular base 11 are respectively locked onto the two second grooves 14. One end of the two matching cables 32 on the right side of the annular base 11 is respectively electrically connected to the two first balun arms 121 on the right side of the annular base 11. That is, any two matching cables 32 arranged at intervals are respectively electrically connected to the first radiating arm 21 and the second radiating arm 22 on the two oscillator arms 2 arranged at intervals, further optimizing cross-polarization.

[0039] The radiation unit also includes a connecting base 6, which comprises a base plate 61, four limiting blocks 62, four fourth latches 63, and at least two insertion buckles 64. The base plate 61 abuts against the bottom of the annular base 11. The four limiting blocks 62 are respectively arranged around the outer side of the base plate 61, and are respectively located on the side of the base plate 61 facing the annular base 11. The four fourth latches 63 are respectively located one-to-one with the four limiting blocks 62 facing the annular base. On one side of 11, four fourth buckles 63 are respectively engaged on the annular base 11, at least two plug buckles 64 are respectively disposed on the side of the base plate 61 facing away from the annular base 11, four limiting blocks 62 are engaged on the periphery of the annular base 11, and four fourth buckles 63 are engaged on the annular base 11 to engage and fix the connecting base 6 and the radiation unit, and are connected to the external reflector or housing through at least two plug buckles 64, thereby fixing the low-frequency radiation unit.

[0040] It is understood that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of this utility model, and all such substitutions or changes should fall within the protection scope of this utility model.

Claims

1. A radiation unit, characterized by include: Baron seat (1), the baron seat (1) includes an annular base (11) and four baron arms (12), the four baron arms (12) are all straight structures, one end of the four baron arms (12) is connected to the periphery of the annular base (11), and the four baron arms (12) are all inclined toward one side of the top of the annular base (11); The vibrating arm (2) includes four arms, and the four arms (2) are respectively connected to the side of the four balun arms (12) away from the annular base (11); The power supply assembly (3) includes two power supply terminals (31) and four matching cables (32). The four matching cables (32) are respectively clamped on the four balun arms (12). One end of the four matching cables (32) is electrically connected to the four vibrating arms (2) respectively. The two power supply terminals (31) are respectively passed through the annular base (11). The other end of any two matching cables (32) spaced apart is electrically connected to any one of the power supply terminals (31). The other end of the other two matching cables (32) is electrically connected to the other power supply terminal (31). The connecting components (4) include four components. Each connecting component (4) includes a vibrator buckle (41) and two buckle seats (42). The two ends of the vibrator buckle (41) are respectively engaged with the two buckle seats (42). The two buckle seats (42) are symmetrically arranged along the center line of the vibrator buckle (41). The far end of the two buckle seats (42) is respectively connected to the adjacent ends of the two adjacent vibrator arms (2).

2. A radiation unit according to claim 1, characterized in that Each of the buckle seats (42) is provided with a through hole (421) and a radiating surface (422). The through hole (421) is inserted along the height direction of the buckle seat (42), and the radiating surface (422) is disposed in the through hole (421). The radiating surface (422) is flush with the vibrator arm (2).

3. A radiation unit according to claim 2, characterized in that Each of the snap seats (42) includes a sleeve (423), a U-shaped member (424), and a card slot (425). The open end of the U-shaped member (424) is connected to the outside of the sleeve (423). A through hole (421) is formed between the U-shaped member (424) and the sleeve (423). The end of the U-shaped member (424) far from the opening is connected to the oscillator arm (2). The card slot (425) is provided on the U-shaped member (424). The oscillator snap (41) includes a concave kit (411), a stop block (412), two insertion blocks (413), and two first snaps (414). The stop block (412) is provided in the middle of the inner side of the concave kit (411). The two sleeves (423) are respectively abutted against both sides of the stop block (412). The two insertion blocks (413) are provided on both sides of the inner side of the concave kit (411) opposite to the stop block (412). The two insertion blocks (413) are respectively inserted into the two sleeves (423) in a one-to-one correspondence. The two first snaps (414) are respectively provided on both sides of the concave kit (411). The two first snaps (414) are respectively clamped with the card slots (425) on the two sleeves (423) in a one-to-one correspondence.

4. A radiation unit according to claim 3, characterized in that The cross-sectional shape of the sleeve (423) is in a figure-eight shape, and rounded corners (426) are provided on both the inner and outer sides of the sleeve (423).

5. A radiating unit according to claim 1, characterized in that, Each of the oscillator arms (2) includes a first radiation arm (21) and a second radiation arm (22). The first radiation arm (21) and the second radiation arm (22) are symmetrically provided on both sides of any one of the balun arms (12).

6. A radiation unit according to claim 5, characterized in that Each of the balun arms (12) includes a first balun arm (121) and a second balun arm (122). One ends of the first balun arm (121) and the second balun arm (122) are respectively connected to the annular base (11). The first radiation arm (21) is connected to the other end of the first balun arm (121). The second radiation arm (22) is connected to the other end of the second balun arm (122). The radiation unit further includes four reinforcing sleeves (5). The four reinforcing sleeves (5) are respectively arranged in a one-to-one correspondence with the four balun arms (12). Both ends of each of the reinforcing sleeves (5) are respectively connected to the first balun arm (121) and the second balun arm (122) of the same balun arm (12).

7. A radiation unit according to claim 6, characterized in that Each of the aforementioned reinforcing clips (5) includes a clip assembly (51), a spacer block (52), two second snaps (53), two third snaps (54), and two limiting posts (55). The clip assembly (51) is snapped onto the baron arm (12). The spacer block (52) is located on the middle of the inner side of the clip assembly (51). The two sides of the spacer block (52) abut against the first baron arm (121) and the second baron arm (122), respectively. The two second snaps (53) are located on both sides of one end of the clip assembly (51). The two third snaps (54) are located on the two sides of one end of the clip assembly (51). Two buckles (53) are respectively snapped onto both sides of the first radiating arm (21), two third buckles (54) are respectively located on both sides of the other end of the card set (51), two third buckles (54) are respectively snapped onto both sides of the second radiating arm (22), two limiting posts (55) are respectively located on both ends of the inner side of the card set (51), the first radiating arm (21) and the second radiating arm (22) are respectively provided with insertion holes (23), and the two limiting posts (55) are respectively inserted into the two insertion holes (23) one by one.

8. A radiation unit according to claim 6, characterized in that The two first balun arms (121) on the left side of the annular base (11) are respectively provided with first grooves (13). The two matching cables (32) on the left side of the annular base (11) are respectively locked in the two first grooves (13). One end of the two matching cables (32) on the left side of the annular base (11) is respectively electrically connected to the two second balun arms (122) on the left side of the annular base (11). The two second balun arms (122) on the right side of the annular base (11) are respectively provided with second grooves (14). The two matching cables (32) on the right side of the annular base (11) are respectively locked in the two second grooves (14). One end of the two matching cables (32) on the right side of the annular base (11) is respectively electrically connected to the two first balun arms (121) on the right side of the annular base (11).

9. A radiation unit according to claim 1, characterized in that The radiation unit also includes a connecting base (6), which includes a base plate (61), four limiting blocks (62), four fourth buckles (63), and at least two plug-in buckles (64). The base plate (61) abuts against the bottom of the annular base (11). The four limiting blocks (62) are respectively arranged around the outer side of the base plate (61) and are respectively located on the side of the base plate (61) facing the annular base (11). The four fourth buckles (63) are respectively located on the side of the four limiting blocks (62) facing the annular base (11) and are respectively locked onto the annular base (11). At least two plug-in buckles (64) are respectively located on the side of the base plate (61) facing away from the annular base (11).

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