Angle-adjustable flexible electric vehicle charging head

Abstract

The utility model discloses an angle-adjustable flexible electric vehicle charging head, which is characterized in that a self-locking mechanism is arranged in a charging seat, the self-locking mechanism is used for fixing a plugging end, a positioning shaft is arranged in a fixed end, the upper part of the positioning shaft penetrates through the fixed end, a nut is arranged on the upper part of the positioning shaft, and a semicircular head is arranged at the bottom of the positioning shaft and is matched with a semicircular groove; limiting bolts are symmetrically arranged at the two ends of the semicircular head and are matched with the stabilizing grooves, the semicircular head and the semicircular grooves are matched with each other, so that the positioning shaft can conveniently shake in the semicircular grooves, and the limiting bolts and the stabilizing grooves are matched with each other, so that the plugging end can only shake back and forth in the left-right and up-down directions, namely, the left-right and up-down inclination angle adjustment is realized; and the inclination angle of the plugging end is adjustable, so that alignment plugging can be assisted, a proper matching error can be generated between the joint assembly and the charging seat in an adjustable range, and the plugging difficulty of the charging seat and the plugging end is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of charging, and in particular relates to a flexible electric vehicle charging head with adjustable angle. Background Art

[0002] Shared transportation is the sum of various smart travel modes that integrate social idle vehicles, car space or driving skills and other transportation resources under the background of sharing economy, relying on the Internet platform, and efficiently matching travel supply and demand through big data calculation to achieve shared travel capabilities. There are many modes of shared transportation, such as platform-based shared transportation, bicycle sharing, short-distance travel sharing, long-distance travel sharing and electric car sharing.

[0003] At present, shared charging vehicles require manual insertion of batteries. Users do not park at designated locations, which undoubtedly greatly increases labor costs and the difficulty of battery replacement. The vehicle cannot be locked at a designated location, and users charge directly by plugging it in. Most plugging methods are rigid connections, which can easily cause damage to the charging seat and charging head during the charging process. In addition, the rigidly connected charging seat and charging head will damage the conductive pins and reeds inside the charging seat and charging head when the vehicle is swung left and right or up and down manually. Utility Model Content

[0004] The purpose of the utility model is to provide an angle-adjustable flexible electric vehicle charging head to solve the problems in the prior art that the rigid connection easily causes damage to the charging seat and the charging head, the conductive pins and springs inside the charging seat and the charging head are damaged when the car is swung left and right or up and down manually, and the car is automatically locked.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An angle-adjustable flexible electric vehicle charger comprises a charging seat, wherein a charging compartment is provided inside the charging seat, wherein the inner wall of the charging compartment has symmetrical slideways, wherein the inner wall of the charging compartment also has symmetrical limit grooves, wherein a locking tongue is installed on one side of the inner wall of the charging compartment below the limit groove, and wherein a conductive sheet is provided inside the charging compartment;

[0007] It also includes a connector assembly, which is used to be plugged into the charging compartment for charging. The connector assembly is divided into a plug-in end and a fixed end. The plug-in end is used to plug and cooperate with the charging compartment, and the fixed end is used to be fixed to the electric vehicle, wherein the inclination angle of the plug-in end is adjustable in the fixed end, and the fixed end is used to limit the inclination angle of the plug-in end;

[0008] A self-locking mechanism is installed inside the charging seat, and the self-locking mechanism is used to fix the plug-in end.

[0009] Preferably, the inner wall of the plug-in end is provided with an inner column, a mounting plate is bolted on the top of the inner column, a shaft cylinder is provided above the mounting plate, a conductive groove is fixed to the bottom of the plug-in end, a semicircular groove is provided at the center of the mounting plate, stabilizing grooves are symmetrically opened on both sides of the semicircular groove, and a shaft cylinder is provided above the semicircular groove.

[0010] Preferably, the lower part of the stable groove passes through a semicircular groove, and the upper part of the stable groove remains closed in the semicircular groove. When the positioning shaft swings to the maximum distance, the limit bolt will hit the closed part above the stable groove, thereby achieving the limiting function.

[0011] Preferably, a positioning shaft is installed inside the fixed end, a nut is installed above the positioning shaft passing through the fixed end, a semicircular head and a semicircular groove are provided at the bottom of the positioning shaft to cooperate with each other, and limit bolts and stabilizing grooves are symmetrically provided at both ends of the semicircular head to cooperate with each other.

[0012] Preferably, the positioning shaft is sleeved with a sleeve and a first spring, and the first spring acts between the sleeve and the fixed end. The first spring effectively improves the flexibility of the joint assembly and also increases the service life of the plug end and the fixed end.

[0013] Preferably, the inclination adjustment range of the plug end is from 0° to 30°. Within this range, the positioning axis can be deflected at an inclination angle to reduce the plugging error between the plug end and the charging seat.

[0014] Preferably, the self-locking mechanism includes a shell, which is fixed in the charging base, and a slide rail is provided inside the shell, and an L slider is slidably connected to the slide rail, the short side of the L slider is fixed to one side of the lock tongue, and a rectangular groove is opened on the long side of the L slider. A motor and a spring block are also provided in the shell, and the output end of the motor is connected to an output disk, and an eccentric shaft is fixed on the surface of the output disk and enters the rectangular groove, and a second spring is fixed inside the spring block, wherein the second spring supports the short side of the L slider.

[0015] Preferably, a self-locking hole is provided on the side of the plug-in end for cooperating with a locking tongue, and side blocks are symmetrically provided on the outer wall of the plug-in end.

[0016] The technical solution of the utility model has the following beneficial effects:

[0017] 1. The cooperation between the semicircular head and the semicircular groove can facilitate the swing of the positioning shaft inside the semicircular groove. The cooperation between the limit bolt and the stabilizing groove makes it possible for the plug-in end to only swing back and forth left and right, up and down, that is, the left and right up and down inclination angle adjustment. During the process of plugging and charging, the adjustable inclination angle of the plug-in end can assist in alignment and plugging, and allow a moderate amount of matching error between the connector assembly and the charging seat within the adjustable range, thereby reducing the difficulty of plugging the charging seat and the plug-in end.

[0018] 2. When the plug-in end is inserted into the charging seat and locked, the plug-in end will be fixed inside the charging seat, and the fixed end can swing left and right with the car under the cooperation of the limit bolt and the stabilizing slot, so as to avoid damage to the plug-in end and the charging seat caused by artificial swinging of the car left and right and up and down, and play a role in protecting the conductive slot and the conductive sheet. It solves the problem that the hard connection between the car body and the charging seat will cause damage to the charging seat and the plug-in end.

[0019] 3. Insert the plug-in end into the charging compartment, and the bottom of the plug-in end will squeeze the lock tongue, which will then retreat into the shell and continue to push the plug-in end downward. When the plug-in end is completely inserted into the charging compartment, the thrust generated by the second spring will push the lock tongue into the self-locking hole to achieve the self-locking function. When the charging is completed and the car is to be taken out, you only need to operate the starter motor, the output disk will rotate to drive the eccentric shaft to rotate, that is, the eccentric shaft pushes the L slider, thereby pulling the lock tongue inward, so that the lock tongue is out of the self-locking hole to complete the car removal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for describing the embodiments are briefly introduced below.

[0021] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0022] Figure 2 This is a schematic diagram of the structure of the charging base of the utility model.

[0023] Figure 3 It is a schematic diagram of the assembly and disassembly structure of the utility model.

[0024] Figure 4 It is a partial cross-sectional view of the utility model.

[0025] Figure 5 For the utility model Figure 4 Split diagram.

[0026] Figure 6 It is a structural schematic diagram of the self-locking mechanism of the utility model.

[0027] Figure 7 It is a schematic diagram of the internal structure of the self-locking mechanism of the utility model.

[0028] Figure 8 It is a cross-sectional view of the connector assembly of the present utility model.

[0029] Fig. 9 This is a disassembled cross-sectional view of the connector assembly of the present invention.

[0030] Fig.10 It is a schematic diagram of the local structure of the joint assembly of the utility model.

[0031] Fig.11 It is a schematic diagram of the overall structure of the joint assembly of the utility model.

[0032] Reference numerals: 10, charging seat; 11, charging compartment; 12, slideway; 13, limit groove; 14, conductive sheet;

[0033] 15. Plug-in end; 16. Fixed end; 17. Side block; 18. Boss; 19. Conductive slot; 20. Inner column; 21. Mounting plate; 22. Shaft cylinder; 23. Semicircular slot; 24. Stopper; 25. Positioning shaft; 26. Sleeve; 27. First spring; 28. Semicircular head; 29. ​​Stop bolt; 30. Stable slot; 31. First mounting ear; 32. Second mounting ear; 33. Nut;

[0034] 34. Self-locking hole; 37. Lock tongue; 38. Housing; 39. L slider; 40. Spring block; 41. Second spring; 42. Slide rail; 43. Motor; 44. Output disk; 45. Eccentric shaft; 46. Rectangular groove. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0036] Embodiment 1:

[0037] refer to Figure 1 , a flexible electric vehicle charger with adjustable angle, including a charging seat 10, the charging seat 10 is fixed in a charging base station, the charging base station directly supplies power to the charging seat 10, a charging compartment 11 is arranged inside the charging seat 10, the inner wall of the charging compartment 11 is symmetrically provided with slideways 12, the inner wall of the charging compartment 11 is also symmetrically provided with limiting grooves 13, a locking tongue 37 is installed on one side of the inner wall of the charging compartment 11 below the limiting groove 13, and a conductive sheet 14 is arranged inside the charging compartment 11;

[0038] In the above scheme, the outer wall of the plug-in terminal 15 is symmetrically provided with side blocks 17, wherein the side blocks 17 are arranged on the outer wall of the plug-in terminal 15 in an inclined manner from top to bottom, and the side blocks 17 cooperate with the slide 12. The unique positioning of the side blocks 17 and the slide 12 can make it more convenient for the user to align and plug in the charging compartment 11, and can also help the plug-in terminal 15 to stabilize in the charging compartment 11, and prevent the problem of displacement in the charging compartment 11. The setting of the side blocks 17 that are inclined and reduced from top to bottom can make the plug-in process of the plug-in terminal 15 and the charging compartment 11 smoother. A conductive groove 19 is fixed at the bottom of the plug-in terminal 15. When the electric vehicle needs to be charged, the mobile electric vehicle plugs the plug-in terminal 15 into the charging compartment 11. After the plug-in is completed, the conductive groove 19 and the conductive sheet 14 correspond to each other to start power supply.

[0039] Furthermore, the outer wall of the plug-in terminal 15 is also provided with a protruding platform 18 that cooperates with the limiting groove 13. The combination of the protruding platform 18 and the limiting groove 13 provides the maximum plugging distance of the plug-in terminal 15, while further improving the stability of the plug-in terminal 15, and improving the electrical connection effect between the conductive groove 19 and the conductive sheet 14, so that the charging is stable and efficient.

[0040] refer to Figure 1-Figure 3 , a connector assembly is used to be plugged into the charging compartment 11 for charging. The connector assembly is divided into a plug-in end 15 and a fixed end 16. The plug-in end 15 is used to plug and cooperate with the charging compartment 11, and the fixed end 16 is used to be fixed to the electric vehicle. The top of the fixed end 16 is symmetrically provided with a first mounting ear 31 and a second mounting ear 32. There is a distance between the first mounting ear 31 and the second mounting ear 32. The distance formed between the first mounting ear 31 and the second mounting ear 32 is stuck in a shape that matches it and is fixed by a nut. The matching shape is the head of the electric vehicle, so that the connector assembly will be fixed to the electric vehicle.

[0041] refer to Figure 8-11 The inner wall of the plug end 15 is provided with an inner column 20, a mounting plate 21 is bolted on the upper part of the inner column 20, a shaft cylinder 22 is provided on the upper part of the mounting plate 21, a semicircular groove 23 is provided at the center of the mounting plate 21, a stabilizing groove 30 is symmetrically opened on both sides of the semicircular groove 23, a shaft cylinder 22 is provided on the upper part of the semicircular groove 23, a positioning shaft 25 is installed inside the fixed end 16, and a nut 33 is installed on the upper part of the positioning shaft 25 passing through the fixed end 16. A sleeve 26 and a first spring 27 are sleeved on the positioning shaft 25, and the first spring 27 acts between the sleeve 26 and the fixed end 16.

[0042] In the above scheme, for the assembly between the plug-in end 15 and the fixed end 16, first insert the lower part of the positioning shaft 25 into the mounting plate 21, and insert it upward from the lower part of the mounting plate 21, and then fix the baffle 24 under the mounting plate 21 to prevent the positioning shaft 25 from falling off, then first sleeve the sleeve 26 on the positioning shaft 25 and then insert the first spring 27, and then pass the bottom of the positioning shaft 25 through the fixed end 16, and screw the nut 33 into the bottom of the positioning shaft 25, and finally fit the four sides of the mounting plate 21 on the inner column 20 and position the mounting plate 21 by bolts, so that the plug-in end 15 is installed in the fixed end 16. The use of the first spring 27 can keep the positioning shaft 25 lifted up. When the plug-in end 15 is plugged into the charging compartment 11, an impact force will be generated. At this time, the fixed end 16 will be slightly displaced downward under the action of the first spring 27, thereby buffering and reducing the force generated during plugging, effectively protecting the charging stand 10, and effectively improving the flexibility of the joint assembly under the action of the first spring 27, while also improving the service life of the plug-in end 15 and the fixed end 16. The maximum displacement distance of the plug-in end 15 under the action of the spring is limited by the shaft cylinder 22. When the top of the shaft cylinder 22 contacts the bottom of the fixed end 16, it is the maximum displacement distance.

[0043] Further references Figure 8-Figure 10 The inclination angle of the plug-in end 15 can be adjusted in the fixed end 16, and the fixed end 16 is used to limit the inclination angle of the plug-in end 15. A semicircular head 28 is provided at the bottom of the positioning shaft 25 to cooperate with the semicircular groove 23, and limit bolts 29 are symmetrically provided at both ends of the semicircular head 28 to cooperate with the stabilizing groove 30.

[0044] In the above scheme, the semicircular head 28 cooperates with the semicircular groove 23 to facilitate the swaying of the positioning shaft 25 inside the semicircular groove 23, and the limit bolt 29 cooperates with the stabilizing groove 30, so that the plug-in end 15 can only swing back and forth left and right, that is, the left and right up and down inclination angle adjustment. During the plug-in charging process, the adjustable inclination function of the plug-in end 15 can assist in alignment and plugging, and allow the connector assembly and the charging seat 10 to produce a proper amount of matching error within the adjustable range, thereby reducing the difficulty of plugging the charging seat 10 and the plug-in end 15. At the same time, when the plug-in end 15 is inserted into the charging seat 10 and locked, the plug-in end 15 will be fixed inside the charging seat 10, and the fixed end 16 can swing left and right and up and down with the car under the cooperation of the limit bolt 29 and the stabilizing groove 30, so as to avoid damage to the plug-in end 15 and the charging seat 10 caused by artificially swinging the car left and right and up and down, and play a role in protecting the conductive groove 19 and the conductive sheet 14. The problem that the hard connection between the vehicle body and the charging base 10 may cause damage to the charging base 10 and the plug-in terminal 15 is solved.

[0045] Furthermore, the semicircular groove 23 is passed through the bottom of the stabilizing groove 30 to facilitate the installation and insertion of the positioning shaft 25. The top of the stabilizing groove 30 remains closed in the semicircular groove 23 to limit the maximum inclination degree of the positioning shaft 25. When the positioning shaft 25 swings to the maximum distance, the limit bolt 29 will hit the closed part above the stabilizing groove 30, thereby achieving the limiting function. The inclination adjustment range of the plug-in terminal 15 is from 0° to 30°. Within this range, the positioning shaft 25 can be deflected at an inclination angle, reducing the plug-in error between the plug-in terminal 15 and the charging base 10.

[0046] refer to Figure 3-Figure 7 A self-locking mechanism is installed inside the charging seat 10, and the self-locking mechanism is used to fix the plug-in terminal 15. The self-locking mechanism includes a housing 38, which is fixed inside the charging seat 10. A slide rail 42 is provided inside the housing 38, and an L slider 39 is slidably connected to the slide rail 42. The short side of the L slider 39 is fixed to one side of the lock tongue 37, and a rectangular groove 46 is provided on the long side of the L slider 39. A motor 43 and a spring block 40 are also provided inside the housing 38. The output end of the motor 43 is connected to an output disk 44, and an eccentric shaft 45 is fixed on the surface of the output disk 44, which enters the rectangular groove 46. A second spring 41 is fixed inside the spring block 40, wherein the second spring 41 supports the short side of the L slider 39. A self-locking hole 34 is provided on the side of the plug-in terminal 15 for matching the lock tongue 37.

[0047] In the above scheme, the initial position of the lock tongue 37 is pushed out of the housing 38 by the second spring 41 and enters the charging compartment 11. During the charging process, the plug end 15 is inserted into the charging compartment 11, and the bottom of the plug end 15 will squeeze the lock tongue 37, and the lock tongue 37 will retreat into the housing 38, and continue to push the plug end 15 downward. When the plug end 15 is completely inserted into the charging compartment 11, the thrust generated by the second spring 41 pushes the lock tongue 37 into the self-locking hole 34 to achieve the self-locking function. When the charging is completed and the vehicle is taken, it is only necessary to operate the starter motor 43, and the output disk rotates to drive the eccentric shaft 45 to rotate, that is, the eccentric shaft 45 pushes the L slider 39, thereby pulling the lock tongue 37 inward, so that the lock tongue 37 is out of the self-locking hole 34 to complete the vehicle. The self-locking mechanism can automatically lock the electric vehicle. It only needs to insert the plug end 15 into the charging seat 10. The self-locking can prevent the electric vehicle from being stolen, which greatly improves the protection function of the device.

[0048] Embodiment 2:

[0049] The above-mentioned self-locking mechanism and the control of the motor 43 can be connected to a remote control terminal for control. The remote control terminal is a mobile phone, a computer cloud, etc., and is further connected to the Internet of Things APP control. The user only needs to scan the code to directly control the start of the motor 43 through the mobile phone to complete the vehicle pickup operation. This device is suitable for the use of shared electric vehicles and is suitable for wide promotion.

[0050] The specific implementation process of this embodiment is as follows:

[0051] When in use, when charging the electric vehicle, the mobile electric vehicle will insert the plug-in terminal 15 into the charging compartment 11. After the plug-in is completed, the conductive groove 19 and the conductive sheet 14 correspond to each other to start power supply. The unique positioning of the side block 17 and the slide 12 can make it more convenient for the user to align and plug it into the charging compartment 11. At the same time, it can also help the plug-in terminal 15 to stabilize inside the charging compartment 11 and prevent the problem of offset inside the charging compartment 11.

[0052] When the plug-in end 15 is inserted into the charging compartment 11, the bottom of the plug-in end 15 will squeeze the lock tongue 37, and the lock tongue 37 will retreat into the shell 38, and continue to push the plug-in end 15 downward. When the plug-in end 15 is completely inserted into the charging compartment 11, the thrust generated by the second spring 41 pushes the lock tongue 37 into the self-locking hole 34 to achieve the self-locking function. When the charging is completed and the vehicle is taken away, it is only necessary to operate the starting motor 43, the output disk rotates to drive the eccentric shaft 45 to rotate, that is, the eccentric shaft 45 pushes the L slider 39, thereby pulling the lock tongue 37 inward, so that the lock tongue 37 is out of the self-locking hole 34 to complete the vehicle removal.

[0053] The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Various modifications or equivalent substitutions may be made to the present invention within the essence and protection scope of the present invention. Such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

[0054] In the description of the present utility model, it should be noted that the terms "inside", "front", "back", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the attached circles, or the directions or positional relationships in which the utility model product is usually placed when in use, and are only used to facilitate the description of the present utility model and simplify the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, these terms indicating directions or positional relationships cannot be understood as limiting the present utility model.

[0055] In the description of the present invention, it is further explained that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, these terms can indicate a fixed connection, a detachable connection, or an integral connection between elements; they can also indicate a mechanical connection, an electrical connection; they can also indicate a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

Claims

1. An angle-adjustable flexible electric vehicle charger, characterized in that: The device comprises a charging seat (10), wherein a charging compartment (11) is provided inside the charging seat (10), a slideway (12) is symmetrically provided on the inner wall of the charging compartment (11), a limiting groove (13) is also symmetrically provided on the inner wall of the charging compartment (11), a locking tongue (37) is installed on one side of the inner wall of the charging compartment (11) below the limiting groove (13), and a conductive sheet (14) is provided inside the charging compartment (11); It also includes a connector assembly, which is used to be plugged into the charging compartment (11) for charging, and the connector assembly is divided into a plug end (15) and a fixed end (16), the plug end (15) is used to be plugged with the charging compartment (11), and the fixed end (16) is used to be fixed to the electric vehicle, wherein the inclination angle of the plug end (15) is adjustable in the fixed end (16), and the fixed end (16) is used to limit the inclination angle of the plug end (15); A self-locking mechanism is installed inside the charging seat (10), and the self-locking mechanism is used to fix the plug-in end (15).

2. The angle-adjustable flexible electric vehicle charger according to claim 1, characterized in that: The inner wall of the plug end (15) is provided with an inner column (20), a mounting plate (21) is bolted on the upper side of the inner column (20), a shaft cylinder (22) is provided on the upper side of the mounting plate (21), a conductive groove (19) is fixed on the bottom of the plug end (15), a semicircular groove (23) is provided at the center of the mounting plate (21), stabilizing grooves (30) are symmetrically provided on both sides of the semicircular groove (23), and a shaft cylinder (22) is provided on the upper side of the semicircular groove (23).

3. The angle-adjustable flexible electric vehicle charger according to claim 2, characterized in that: The lower part of the stabilizing groove (30) passes through the semicircular groove (23), and the upper part of the stabilizing groove (30) remains closed in the semicircular groove (23).

4. The angle-adjustable flexible electric vehicle charger according to claim 3, characterized in that: A positioning shaft (25) is installed inside the fixed end (16), and a nut (33) is installed above the positioning shaft (25) passing through the fixed end (16). A semicircular head (28) is provided at the bottom of the positioning shaft (25) and cooperates with the semicircular groove (23). Limiting bolts (29) and stabilizing grooves (30) are symmetrically provided at both ends of the semicircular head (28) and cooperate with each other.

5. The angle-adjustable flexible electric vehicle charger according to claim 4, characterized in that: The positioning shaft (25) is sleeved with a sleeve (26) and a first spring (27), and the first spring (27) acts between the sleeve (26) and the fixed end (16).

6. The angle-adjustable flexible electric vehicle charger according to claim 5, characterized in that: The inclination angle of the plug end (15) is adjustable in the range of 0° to 30°.

7. The angle-adjustable flexible electric vehicle charger according to claim 6, characterized in that: The self-locking mechanism comprises a shell (38), wherein the shell (38) is fixed in a charging seat (10), a slide rail (42) is arranged inside the shell (38), an L slider (39) is slidably connected to the slide rail (42), the short side of the L slider (39) is fixed to one side of a lock tongue (37), a rectangular groove (46) is opened on the long side of the L slider (39), a motor (43) and a spring block (40) are also arranged in the shell (38), the output end of the motor (43) is connected to an output disk (44), an eccentric shaft (45) is fixed on the surface of the output disk (44) and enters the rectangular groove (46), a second spring (41) is fixed inside the spring block (40), wherein the second spring (41) supports and presses against the short side of the L slider (39).

8. The angle-adjustable flexible electric vehicle charger according to claim 6, characterized in that: A self-locking hole (34) is provided on the side of the plug-in end (15) for matching with a locking tongue (37), and a side block (17) is symmetrically provided on the outer wall of the plug-in end (15).

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