Rotary connector based on Bluetooth signal

Abstract

The invention discloses a rotary connector based on a Bluetooth signal. The rotary connector comprises an upper cover (1) and a lower cover (3) which is rotatably arranged relative to the upper cover (1), a Bluetooth transmitting plate (6) for transmitting Bluetooth signals and a Bluetooth receiving plate (7) for receiving the Bluetooth signals are sequentially arranged between the upper cover (1) and the lower cover (3); the Bluetooth transmitting plate (6) is fixedly connected with the upper cover (1) and is electrically connected with a steering wheel electric device through an upper needle seat (11) arranged on the upper cover (1); and the Bluetooth receiving plate (7) is fixedly connected with the lower cover (3) and is electrically connected with the automobile steering column combination switch through a lower needle seat (31) arranged on the lower cover (3). The rotary connector based on the Bluetooth signal is stable and reliable in signal transmission and good in function expansibility.

Description

Technical Field

[0001] The invention relates to the technical field of automobile steering wheels, in particular to a rotary connector based on Bluetooth signals. Background Art

[0002] The rotary connector, also known as the clock spring, is used to be installed between the steering wheel and the steering column combination switch to ensure a reliable electrical connection between the two relatively rotating parts of the steering wheel electrical components and the steering column combination switch. The steering wheel electrical components include not only airbags, but also various switches, such as safety key switches, audio function switches, cruise switches, car phone switches, etc. The structure of the conventional rotary connector is described in the Chinese utility model patent "A rolling bracket clock spring" (application number: 202222072933.4, application date: 2022.08.08), including a flexible flat cable wound in a cavity formed by a rotor and a stator, and electrically connected to the rotor and the stator at both ends; the stator is fixed on the steering column combination switch and electrically connected to the combination switch, and the rotor is fixed on the steering wheel and electrically connected to the electrical components on the steering wheel; the rotor rotates with the steering wheel, and the flexible flat cable is coiled in the annular cavity like a spring. When the steering wheel rotates forward, the flexible flat cable is wound tightly, and when the steering wheel rotates reversely, the flexible flat cable gradually relaxes.

[0003] However, the electrical connection between the rotor and the stator of the conventional rotary connector is realized by a flexible flat cable. On the one hand, the maximum number of rotations of the steering wheel is limited by the length of the wiring harness, and the flat cable may be tangled or broken, affecting the reliability of signal transmission. On the other hand, due to the existence of a certain length of flexible flat cable, it is difficult to further miniaturize the clock spring. On the other hand, in order to prevent the flexible flat cable from being misaligned, the clock spring must be strictly aligned during loading and maintenance, which increases the difficulty of assembly and reduces the accuracy of use.

[0004] The problems of conventional structural rotary connectors become more prominent and serious as more and more functions are integrated on the steering wheel. To this end, the industry is exploring a variety of new improvement schemes. The Chinese utility model patent "Clock Spring for Automobile" (application number: 202221579707.9, application date: 2022.06.23) discloses a clock spring for automobiles, which uses a steering wheel-end PCB board, a column-end PCB board and several conductive columns to replace the flat cable of the traditional clock spring to achieve the electrical connection between the steering wheel-end connector and the column-end connector. The coil core is driven to rotate by the toggle member, and the coil core drives the steering wheel-end PCB board to rotate synchronously. Several conductive columns serve as sliding contacts to connect the conductive rings of the steering wheel-end PCB board and the column-end PCB board, so that an electrical circuit is formed between the steering wheel-end connector and the column-end connector.

[0005] For another example, the Chinese utility model patent "New clock spring and steering wheel and vehicle with the clock spring" (application number: 202220185927.7, application date: 2022.01.24) also discloses a clock spring, including an upper cover and a lower cover arranged to rotate relative to the upper cover, an upper conductive surface is arranged on the lower side of the upper cover, a lower conductive surface is arranged on the upper side of the lower cover, and the lower conductive surface is provided with a first convex portion protruding upward along the axial direction of the lower cover, the lower cover abuts against the upper conductive surface through the first convex portion, the first convex portion encloses at least one closed area on the lower conductive surface, and a conductive ball is correspondingly arranged in the closed area, the conductive ball is rotatably limited in the accommodating cavity formed by the upper conductive surface, the lower conductive surface and the first convex portion, and the upper and lower ends of the conductive ball are always rollingly contacting the upper conductive surface and the lower conductive surface respectively. The conductive balls arranged in a plurality of annular conductive groove channels realize stable conduction of the upper and lower conductive surfaces.

[0006] Another Chinese utility model patent "New clock spring and steering wheel and vehicle with the clock spring" (application number: 202220188622.1, application date: 2022.01.24) discloses another clock spring, which includes an upper cover, a lower cover, a rotating wheel mechanism, a conductive device and a conductive slip ring 5. The upper cover and the lower cover are arranged to rotate with each other and constitute an inner cavity for accommodating the rotating wheel mechanism, the conductive device and the conductive slip ring. The rotating wheel mechanism and the conductive slip ring made of copper or copper alloy are fixedly installed on the surface of the lower cover facing the inner cavity. The upper cover is fixedly installed with a conductive device-conductive spring corresponding to the conductive slip ring. The conductive device rotates at the same angular velocity as the upper cover and is pressed against the conductive slip ring, and always maintains electrical connection with the conductive slip ring during rotation. The clock spring realizes a stable electrical connection between the upper cover and the lower cover in relative rotation through the continuous sliding contact between the conductive device and the conductive slip ring.

[0007] However, since the above-mentioned improvement schemes all utilize the sliding contact between the conductive fixing member and the annular track to realize the electrical connection between the rotor and the stator, the following problems are inevitably encountered:

[0008] First, the reliability is low and the service life is not long enough: due to the vibration caused by vehicle driving or turning, or the wear of mechanical contact over time, the contact between the fixings and the annular track may be poor, affecting the reliability and stability of signal transmission; in order to ensure long-term, stable and reliable sliding contact, higher requirements are placed on the mechanical materials and processing accuracy of the electrical connection between the rotor and the stator, which will also increase costs.

[0009] Second, functional upgrades and additions are limited: as the automobile industry becomes increasingly powerful, the functions that need to be realized on the car steering wheel will become more diverse and more numerous, and the functional limitations required for the electrical functional connection of the rotor and stator will not be met. One rotor and one stator can only realize one function.

[0010] The third is the high noise: the rotor and stator transmit signals through wiring harnesses or sliding contacts, and mechanical sliding will generate noise. Especially after a period of use, PCB wear will generate greater mechanical noise. In severe cases, mechanical noise will interfere with the MIC pickup, causing inaccurate sound pickup and recognition errors. Summary of the invention

[0011] The object of the present invention is to provide a rotary connector based on Bluetooth signals, which has stable and reliable signal transmission and good functional expansibility.

[0012] The technical solution to achieve the purpose of the present invention is:

[0013] A rotary connector based on Bluetooth signals comprises an upper cover and a lower cover arranged to rotate relative to the upper cover; a Bluetooth transmitting board for transmitting Bluetooth signals and a Bluetooth receiving board for receiving Bluetooth signals are arranged in sequence between the upper cover and the lower cover; the Bluetooth transmitting board is fixedly connected to the upper cover and is electrically connected to a steering wheel electrical component through an upper needle seat arranged on the upper cover; the Bluetooth receiving board is fixedly connected to the lower cover and is electrically connected to a vehicle steering column combination switch through a lower needle seat arranged on the lower cover.

[0014] Compared with the prior art, the present invention has the following significant advantages:

[0015] 1. Stable and reliable: The present invention uses wireless signals to realize signal transmission between the rotor and the stator, which effectively avoids the vibration caused by vehicle driving or steering, or the influence of mechanical wear on signal transmission, improves the reliability of signal transmission, ensures the stability of the entire control system, and can extend the service life of the entire system;

[0016] 2. Good functional expansibility: Different functions on the car steering wheel of the present invention are distinguished by different code values, and the number of different signals can be greatly increased, which greatly facilitates the addition of functions that need to be realized on the car steering wheel in the later stage, is simple to upgrade, and is not limited by hardware;

[0017] 3. Low noise: The present invention replaces the wiring harness or sliding contact signal transmission with Bluetooth wireless signal transmission between the rotor and the stator, which greatly reduces the noise generated by mechanical sliding.

[0018] 4. Good sealing: The present invention uses Bluetooth wireless signal transmission instead of flexible flat cables, and does not need to be centered during assembly. Therefore, the centering column and the channel for inserting the centering column from the outside of the cavity are eliminated, and the cavity adopts a fully sealed structure. This avoids the problem of reducing signal connection and transmission reliability due to external dust and sand entering the cavity in existing devices, which not only further improves reliability, but also greatly simplifies the structure.

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the exploded structure of the rotary connector based on Bluetooth signal of the present invention.

[0021] Figure 2 yes Figure 1 Schematic diagram of the appearance and structure of the Bluetooth transmitter board.

[0022] Figure 3 yes Figure 1 Schematic diagram of the appearance structure of the Bluetooth receiver board.

[0023] Figure 4 This is the electrical schematic diagram of the Bluetooth transmitter circuit.

[0024] Figure 5 This is the electrical schematic diagram of the Bluetooth receiving circuit.

[0025] In the figure, the upper cover 1, the sleeve 2, the lower cover 3, the fixing ring 4, the upper needle seat 11, the lower needle seat 31,

[0026] Bluetooth transmitting board 6, transmitting substrate 61, transmitting power positive conductive ring 62, transmitting power negative conductive ring 63, Bluetooth transmitting module 64, signal input terminal 66,

[0027] Bluetooth receiving board 7 , receiving substrate 71 , receiving power positive conductive ring 72 , receiving power negative conductive ring 73 , Bluetooth receiving module 74 , and signal output terminal 76 . DETAILED DESCRIPTION

[0028] The rotary connector includes an upper cover 1 and a lower cover 3 that is arranged to rotate relative to the upper cover 1; it usually also includes a through hole passing through the lower cover 3 and the center of the upper cover 1, a fixing ring 4 whose upper end is movably connected to the upper cover 1 and whose lower part is fixedly connected to the lower cover 3; and a sleeve 2 that is sleeved on the outer periphery of the lower cover 3 and the upper cover 1, fixedly connected to the lower cover 3, and sealed and movably connected to the upper cover 1.

[0029] Combination Figure 1 The present invention is a rotary connector based on Bluetooth signals. Between the upper cover 1 and the lower cover 3, a Bluetooth transmitting board 6 for transmitting Bluetooth signals and a Bluetooth receiving board 7 for receiving Bluetooth signals are sequentially provided;

[0030] The Bluetooth transmitter board 6 is fixedly connected to the upper cover 1 and is electrically connected to the steering wheel electrical components via the upper needle seat 11 provided on the upper cover 1;

[0031] The Bluetooth receiving board 7 is fixedly connected to the lower cover 3 , and is electrically connected to the vehicle steering column combination switch via a lower needle seat 31 disposed on the lower cover 3 .

[0032] The signal input terminal 66 of the Bluetooth transmitter board 6 is electrically connected to the upper needle seat 11 provided on the upper cover 1. The upper needle seat 11 is electrically connected to the steering wheel electrical components.

[0033] The signal output terminal 76 of the Bluetooth receiving board 7 is electrically connected to the lower needle seat 31 provided on the lower cover 3. The lower needle seat 31 is electrically connected to the vehicle steering column combination switch.

[0034] As part of the prior art, the sleeve 2 and the lower cover 3 can be detachably fixedly connected, such as Figure 1 The shown snap connection can also form the sleeve 2 and the lower cover 3 in one piece. It is only necessary to make the cavity formed by the upper cover 1, the lower cover 3 and the sleeve 2 sealed and enclosed to accommodate and protect the infrared emitting board 6 and the infrared receiving board 7.

[0035] In the present invention, the sleeve 2 can also be fixedly connected to the upper cover 1 and movably connected to the lower cover 3 in a sealed manner, so that the sleeve 2 and the upper cover 1 rotate together with the steering wheel.

[0036] The rotary connector of the present invention adopts Bluetooth signal transmission, so that the electrical connection between the rotor and the stator is not affected by mechanical contact and vibration, and the signal transmission is stable and reliable. The functions of signal collection, processing, transmission, reception, etc. are integrated and solidified on the upper and lower covers that rotate relatively, which greatly reduces the number of parts, not only can greatly reduce the thickness and volume of the clock spring, but also improve reliability and reduce maintenance work.

[0037] At the same time, since Bluetooth signals are transmitted via radio waves, the signals are not easily interrupted and the transmission accuracy is higher.

[0038] Figure 2 Shown Figure 1 Schematic diagram of the structure of the Bluetooth transmitter board. Figure 4 This is the electrical schematic diagram of the Bluetooth transmitter circuit.

[0039] As an implementation method, Figure 2 As shown, the Bluetooth transmitting board 6 includes a circular transmitting substrate 61, and the inner diameter of the transmitting substrate 61 is slightly larger than the outer diameter of the fixing ring 4 so that the fixing ring 4 can pass through;

[0040] A transmitting power positive conductive ring 62 and a transmitting power negative conductive ring 63 are concentrically arranged on one side of the transmitting substrate 61, and a Bluetooth transmitting module 64 is arranged between the transmitting power positive conductive ring 62 and the transmitting power negative conductive ring 63. The Bluetooth transmitting module 64 is electrically connected to the transmitting power positive conductive ring 62 and the upper needle seat 11 through a signal input terminal 66 disposed on the other side of the transmitting substrate 61.

[0041] like Figure 4As shown, the wired signal from the steering wheel of the car enters the microcontroller through the signal input terminal 66, is processed by the Bluetooth transmitter module, and enters the Bluetooth transmitter module 64, and the Bluetooth signal code value representing the function information is transmitted outward by the Bluetooth transmitter module 64

[0042] Figure 3 Shown Figure 1 Schematic diagram of the structure of the Bluetooth receiver board. Figure 5 This is the electrical schematic diagram of the Bluetooth receiver module.

[0043] As an implementation method, Figure 3 As shown, the Bluetooth receiving board 7 includes a circular receiving substrate 71, and the inner diameter of the receiving substrate 71 is slightly larger than the outer diameter of the fixing ring 4 so that the fixing ring 4 can pass through;

[0044] A positive conductive ring 72 for receiving power and a negative conductive ring 73 for receiving power are concentrically arranged on one side of the receiving substrate 71, a Bluetooth receiving module 74 is arranged between the positive conductive ring 72 for receiving power and the negative conductive ring 73 for receiving power, the Bluetooth receiving module 74 is electrically connected to the negative conductive ring 73 for receiving power, and the negative conductive ring 73 for receiving power is electrically connected to the lower needle seat 31 via a signal output terminal 76 arranged on the other side of the receiving core plate 71;

[0045] The side of the receiving substrate 71 provided with the Bluetooth receiving module 74 is opposite to the side of the transmitting substrate 61 provided with the Bluetooth transmitting module 64 .

[0046] The receiving power positive conductive ring 72 on the receiving substrate 71 is opposite to the transmitting power positive conductive ring 62 on the transmitting substrate 61, and the receiving power negative conductive ring 73 on the receiving substrate 71 is opposite to the transmitting power negative conductive ring 63 on the transmitting substrate 61;

[0047] A plurality of positive power pins 77 are evenly distributed along the circumference of the receiving power positive conductive ring 72, and a plurality of negative power pins 78 are evenly distributed along the circumference of the receiving power negative conductive ring 73; when the Bluetooth transmitting board 6 rotates with the upper cover 1 relative to the Bluetooth receiving board 7, the upper end of the positive power pin 77 keeps in contact with the transmitting power positive conductive ring 62, and the upper end of the negative power pin 78 keeps in contact with the transmitting power negative conductive ring 63. This ensures that the positive and negative power poles of the Bluetooth transmitting board 6 and the Bluetooth receiving board 7 are turned on at the same time.

[0048] A plurality of positive power pins 77 and a plurality of negative power pins 78 are arranged on the Bluetooth receiving board 7. The use of a plurality of power pins in conjunction with a dual power rail can effectively ensure the durability of the power supply.

[0049] As an improvement, the positive power pin 77 and the negative power pin 78 are both gold-plated pins, and the transmitting power positive conductive ring 62 and the transmitting power negative conductive ring 63 are also gold-plated tracks, which can further ensure reliable conduction of the positive power pole and the negative power pole.

[0050] like Figure 5 As shown, the Bluetooth receiving module 74 receives the Bluetooth signal from the Bluetooth transmitting module 64, enters the Bluetooth receiving module, performs code value conversion processing, obtains the LIN bus control signal, and is connected to the vehicle steering column combination switch by wire through the signal output terminal 76 and the lower needle seat 31.

[0051] As a preferred solution, the number of positive power pins 77 is 3-4, which are evenly distributed along the circumference of the positive power receiving conductive ring 72. The number of negative power pins 78 is also 3-4, which are evenly distributed along the circumference of the negative power receiving conductive ring 73.

[0052] As a further improvement, the negative power pins 78 and the positive power pins 77 are arranged alternately along the circumferential direction.

[0053] The negative power pin 78 and the positive power pin 77 are arranged alternately along the circumferential direction, so that the relative position of the Bluetooth transmitting board 6 and the Bluetooth receiving board 7 is more stable, the relative rotation is more balanced, and the electrical connection is more firm and reliable.

[0054] As an improvement, the negative power pin 78 can be extended and retracted along the length direction. The positive power pin 77 can also be extended and retracted along the axial direction. For example, the pin is provided with a spring along the length direction. For example, the two ends are conductive columns and the middle is a spring.

[0055] The ejector pins are retractable along the length direction, which can better ensure that the upper ends of the ejector pins are in strict contact with the conductive ring and reduce wear.

[0056] The Bluetooth transmitting module 64 and the Bluetooth receiving module 74 may adopt any mature technology in the prior art, which will not be described in detail herein.

[0057] Different functions on the automobile steering wheel of the present invention are distinguished by different code values, and the number of different signals can be greatly increased, which greatly facilitates the addition of functions that need to be implemented on the automobile steering wheel in the later stage, is simple to upgrade, is not limited by hardware, and has good functional expansibility.

[0058] The following only takes the most common multimedia, cruise and voice functions as examples to specifically illustrate the implementation methods.

[0059] Implementation of multimedia and cruise functions: The multi-function buttons use AD1, AD2, AD3, and AD4 for voltage sampling, and the sampled voltage is transmitted to the upper cover pin socket of the rotary connector transmitter board by wire, and connected to the IC (Bluetooth receiving module). The IC converts the different received voltage values ​​into different Bluetooth code values. The Bluetooth code values ​​are transmitted through the Bluetooth antenna, and the Bluetooth receiving board receives the Bluetooth code values, which are converted into LIN bus control through the IC, and connected to the wiring harness through the lower board pin socket to the car center console to realize the car media playback and car automatic cruise functions.

[0060] Implementation of voice function: voice is collected through the MIC head on the steering wheel, transmitted to the IC (Bluetooth receiving module) in the Bluetooth transmitting board via wire and converted into different Bluetooth code values. The Bluetooth code values ​​are transmitted through the antenna, received by the Bluetooth receiving board, converted into LIN bus control through IC, and transmitted to the car voice recognizer through the wiring harness to realize its function.

[0061] The present invention uses Bluetooth wireless signals to realize signal transmission between the rotor and stator of the clock spring, effectively avoiding the influence of vibration or mechanical wear on signal transmission, improving the reliability of signal transmission, and ensuring the stability of the entire control system; different functions on the car steering wheel of the present invention are distinguished by different Bluetooth code values, and the increase in the number of signals is not limited by hardware, which greatly facilitates the increase and upgrade of integrated functions on the car steering wheel; at the same time, the present invention replaces the signal transmission between the rotor and the stator by wiring harness or sliding contact with Bluetooth wireless signal transmission, which greatly reduces the noise generated by mechanical sliding. The rotary connector of the present invention no longer has a flexible flat cable, and there is no need to center the flexible flat cable during assembly, so the cavity can adopt a fully sealed structure, which further improves reliability. This advantage is more significant for vehicles that often travel in dusty and sandy environments, such as commercial trucks. At the same time, the structure of the rotary connector is also simplified.

Claims

1. A rotary connector based on Bluetooth signals, comprising an upper cover (1) and a lower cover (3) arranged to rotate relative to the upper cover (1); characterized in that: A Bluetooth transmitting board (6) for transmitting Bluetooth signals and a Bluetooth receiving board (7) for receiving Bluetooth signals are sequentially arranged between the upper cover (1) and the lower cover (3); The Bluetooth transmitting board (6) is fixedly connected to the upper cover (1), and is electrically connected to the steering wheel electrical components via an upper needle seat (11) provided on the upper cover (1); The Bluetooth receiving board (7) is fixedly connected to the lower cover (3), and is electrically connected to the automobile steering column combination switch via a lower needle seat (31) provided on the lower cover (3).

2. The rotary connector based on Bluetooth signal according to claim 1, characterized in that: A fixing ring (4) and a sleeve (2) are also provided; the fixing ring (4) passes through the through holes in the center of the lower cover (3) and the upper cover (1), the upper end of which is movably connected to the upper cover (1), and the lower part of which is fixedly connected to the lower cover (3); the sleeve (2) is sleeved on the outer periphery of the lower cover (3) and the upper cover (1), and is fixedly connected to the lower cover (3), and is sealed and movably connected to the upper cover (1).

3. The rotary connector based on Bluetooth signal according to claim 2, characterized in that: The Bluetooth transmitting board (6) comprises a circular transmitting base plate (61), the inner diameter of the transmitting base plate (61) being slightly larger than the outer diameter of the fixing ring (4) so ​​as to allow the fixing ring (4) to pass through; A transmitting power positive conductive ring (62) and a transmitting power negative conductive ring (63) are concentrically arranged on one side of the transmitting substrate (61), a Bluetooth transmitting module (64) is arranged between the transmitting power positive conductive ring (62) and the transmitting power negative conductive ring (63), and the Bluetooth transmitting module (64) is electrically connected to the transmitting power positive conductive ring (62) and the upper needle seat (11) through a signal input terminal (66) arranged on the other side of the transmitting substrate (61).

4. The rotary connector based on Bluetooth signal according to claim 3, characterized in that: The Bluetooth receiving board (7) comprises a circular receiving substrate (71), the inner diameter of the receiving substrate (71) being slightly larger than the outer diameter of the fixing ring (4) so ​​as to allow the fixing ring (4) to pass through; A positive conductive ring (72) for receiving power and a negative conductive ring (73) for receiving power are concentrically arranged on one side of the receiving substrate (71); a Bluetooth receiving module (74) is arranged between the positive conductive ring (72) for receiving power and the negative conductive ring (73) for receiving power; the Bluetooth receiving module (74) is electrically connected to the negative conductive ring (73) for receiving power; and the negative conductive ring (73) for receiving power is electrically connected to the lower needle seat (31) via a signal output terminal (76) arranged on the other side of the receiving core board (71); The side of the receiving substrate (71) on which the Bluetooth receiving module (74) is provided is opposite to the side of the transmitting substrate (61) on which the Bluetooth transmitting module (64) is provided.

5. The rotary connector based on Bluetooth signal according to claim 4, characterized in that: The receiving power positive conductive ring (72) on the receiving substrate (71) is opposite to the transmitting power positive conductive ring (62) on the transmitting substrate (61), and the receiving power negative conductive ring (73) on the receiving substrate (71) is opposite to the transmitting power negative conductive ring (63) on the transmitting substrate (61); The positive pole pins (77) of the power supply are evenly distributed along the circumference on the receiving power supply positive conductive ring (72), and the negative pole pins (78) of the power supply are evenly distributed along the circumference on the receiving power supply negative conductive ring (73); when the upper cover (1) rotates relative to the lower cover (3), the upper ends of the positive pole pins (77) of the power supply maintain sliding contact with the positive conductive ring (62) of the transmitting power supply, and the upper ends of the negative pole pins (78) of the power supply maintain sliding contact with the negative conductive ring (63) of the transmitting power supply.

6. The rotary connector based on Bluetooth signal according to claim 5, characterized in that: The power source negative electrode ejector pin (78) and the power source positive electrode ejector pin (77) are gold-plated ejectors; The transmitting power source positive conductive ring (62) and the transmitting power source negative conductive ring (63) are gold-plated conductive rings.

7. The rotary connector based on Bluetooth signal according to claim 5, characterized in that: The number of the positive power pins (77) is 3 to 4.

8. The rotary connector based on Bluetooth signal according to claim 7, characterized in that: The number of the negative power pins (78) is 3 to 4.

9. The rotary connector based on Bluetooth signal according to claim 8, characterized in that: The power source negative electrode ejector pins (78) and the power source positive electrode ejector pins (77) are arranged alternately along the circumferential direction.

10. The rotary connector based on Bluetooth signal according to claim 5, characterized in that: The power source negative electrode ejector pin (78) and the power source positive electrode ejector pin (77) are retractable along the axial direction.

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