CN112490700A

CN112490700A - Two-section type electric connector with multi-strand core wires and connecting method thereof

Info

Publication number: CN112490700A
Application number: CN202011352028.3A
Authority: CN
Inventors: 李俊; 张雪琴; 葛臻楠
Original assignee: Jiangnan Shipyard Group Co Ltd
Current assignee: Jiangnan Shipyard Group Co Ltd
Priority date: 2020-11-26
Filing date: 2020-11-26
Publication date: 2021-03-12
Anticipated expiration: 2040-11-26
Also published as: CN112490700B

Abstract

The invention provides a two-section type electric connector with a multi-strand core wire, which comprises a plug section and a tail clamp section, wherein the plug section is electrically connected with the core wire of a cable; the plug section comprises a plug section body and a plug locking ring, and the plug locking ring is sleeved on the peripheral surface of the plug section body; a plurality of welding pins are arranged at one end of the plug section body close to the tail clamping section; the tail clamp section comprises a clamping part arranged at one end far away from the plug section and a connecting pipe positioned between the clamping part and the plug section, and the two-section type electric connector with the stranded core wires is simple in structure, firm and reliable; meanwhile, the invention also provides a connecting method of the two-section type electric connector with the stranded core wires, and the connecting method has the advantages of good mechanical protection effect and strong water tightness of cable connection.

Description

Two-section type electric connector with multi-strand core wires and connecting method thereof

Technical Field

The invention relates to the field of electric connectors, in particular to a two-section type electric connector with multiple strands of core wires and a connecting method thereof.

Background

Patent 200810070414.6 entitled "winding and embedding type assembled cable joint and manufacturing method thereof" mainly describes the manufacturing method of the joint of single-core cables. The cable connection of the electronic cabinet on the ship relates to the requirements of electromagnetic compatibility and electrical performance such as grounding, shielding, filtering and the like, and a multi-strand core cable is often adopted, so that the electric connector and the connection method are not suitable for manufacturing the multi-strand core cable electric connector of the electronic cabinet on the ship.

The multi-strand core wire electric connector and the connecting method in the existing market cannot play a role in protecting the mechanical vibration of the cable, and the connecting cable is easy to break and the like; and, the cable has poor water tightness after being connected with the electric connector.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a two-stage electrical connector with multiple core wires, which is simple in structure, firm and reliable.

The invention provides a two-section type electric connector with a stranded core wire, which comprises a plug section and a tail clamp section, wherein the plug section is electrically connected with the core wire of a cable, the tail clamp section is used for fixing the cable, and the plug section is in threaded connection with the tail clamp section; the plug section comprises a plug section body and a plug locking ring, and the plug locking ring is sleeved on the peripheral surface of the plug section body; a plurality of welding pins are arranged at one end of the plug section body close to the tail clamping section; the tail clamp section comprises a clamping portion and a connecting pipe, wherein the clamping portion is arranged at one end far away from the plug section, and the connecting pipe is located between the clamping portion and the plug section.

Furthermore, the clamping part comprises a clamping screw and at least two arc-shaped clamping pieces, and the at least two clamping pieces are connected end to end through the clamping screw.

Further, the inner diameter of the connecting pipe is gradually reduced from one end close to the plug section to one end of the clamping part.

Further, the clamping part comprises a locking nut which is in threaded connection with the tail end of the connecting pipe, and a locking ring and a locking gasket which are arranged in the connecting pipe; the locking ring and the locking gasket are sequentially arranged along the axis direction of the connecting pipe, and the outer circumferential surfaces of the locking ring and part of the locking gasket are attached to the inner side surface of the connecting pipe; one end of the locking nut, which is far away from the connecting pipe, is provided with a radially inward convex abutting ring; one end of the locking gasket, which is close to the abutting ring, is provided with a radially outward protruding abutting ring matched with the abutting ring; and the connecting pipe is provided with an annular bulge abutted to the locking ring.

Further, be provided with the sticising ring between locking ring and the locking gasket, should sticising the ring and make by elastic material, the outer periphery of sticising ring with the medial surface laminating of connecting pipe.

The invention aims to solve another technical problem of providing a connecting method of a two-section electric connector with a multi-strand core wire, which has good mechanical protection effect and strong water tightness of cable connection.

The invention provides a connecting method of the two-section type electric connector with the stranded core wires, which sequentially comprises the following steps:

s1, cutting the cable insulation sheath of the cable by 2cm to 3cm, straightening the core wire of the cable, and stripping the insulation layer on the core wire by 3-4 mm; sealing the end part of the residual cable insulating sheath on the cable by using an electrical adhesive tape to form a protective adhesive tape layer;

s2, pre-sheathing an insulating sleeve on the core wire and a protective insulating heat-shrinkable sleeve on the cable before welding the core wire and the welding needle; welding the core wire with a welding needle; after the core wire is welded with the welding needle, the exposed core wire and the welding needle are wrapped by the insulating sleeve;

s3, leading out a grounding wire on a shielding layer of the cable;

and S4, connecting the protective insulating heat-shrinkable sleeve into the connecting pipe after heat shrinkage, fixing the protective insulating heat-shrinkable sleeve by using the clamping part, exposing the tail clamping section of the protective insulating heat-shrinkable sleeve part, and grounding the grounding wire.

Further, in the step S1, a cold peeling process is used to perform core insulation removal.

Further, the stranded core wires after insulation removal are stranded according to the original stranding direction, and tin coating treatment is carried out on the stranded core wires.

Further, in step S3, the ground line is drawn in a manner that: and welding a lead on the shielding layer to form a grounding wire led out from the shielding layer.

Further, in step S3, the ground line is drawn in a manner that: 3-8 strands of shielding layer braided wires are picked out from the shielding layer, and the shielding layer braided wires are wrapped by an insulating heat-shrinkable sleeve and then are subjected to heat-shrinkable insulation to form a grounding wire led out from the shielding layer; the diameter of the grounding wire is within 3-4 mm.

As described above, the two-segment electrical connector with multiple core wires and the connecting method thereof according to the present invention have the following advantages:

the two-section type electric connector with the multi-strand core wires has the advantages of simple structure, simple and convenient manufacturing method, high production efficiency, lower cost, basically no pollution, firmness and reliability, and can be suitable for connecting the two-section type electric connector of the shipboard electronic cabinet. According to the connecting method of the two-section type electric connector with the multi-strand core wires, the clamping part locks the part, which is not split, of the cable, so that the anti-seismic function of the connected two-section type electric connector with the multi-strand core wires is enhanced, and therefore the core wires of the cable are protected from being broken easily under the condition that a travelling ship vibrates continuously, and the mechanical protection effect is achieved; the clamping part of the cable electric connector is reliably fastened with the protective insulating heat-shrinkable sleeve of the cable, and the insulating heat-shrinkable sleeve used in the area with the protection requirement is tightly heat-shrunk, so that the water tightness of cable connection is improved.

Drawings

FIG. 1 is a schematic view of a first embodiment of a two-piece electrical connector with multiple core wires;

FIG. 2 is a schematic half-sectional view of a first embodiment of a two-piece electrical connector with multiple core wires;

FIG. 3 is a rear view of a first embodiment of a two-piece electrical connector with multiple strands;

FIG. 4 is a diagram of a cable stripped away when connected to an embodiment of a two-piece electrical connector having a plurality of core wires;

FIG. 5 is a schematic view of a multi-strand two-piece electrical connector after being connected to a cable;

FIG. 6 is a schematic view of a second embodiment of a two-piece electrical connector with multiple strands;

FIG. 7 is a half-sectional view of a second embodiment of a two-piece electrical connector with multiple core wires;

FIG. 8 is a schematic diagram of a two-part electrical connector with a multi-strand core wire with the cable stripped away;

FIG. 9 is a schematic diagram of a multi-strand two-segment electrical connector after being connected to a cable according to a second embodiment.

Reference numerals

100. A cable; 110. a core wire; 120. a cable insulation sheath; 130. an insulating sleeve; 140. a protective insulating heat-shrinkable sleeve; 150. a shielding layer; 160. a protective tape layer; 170. a ground line; 171. cold pressing the joint; 180. an adhesive tape layer for adjusting the diameter of the cable; 200. a plug section; 210. a plug section body; 220. a plug locking ring; 230. welding pins; 300. a tail clamp section; 310. a connecting pipe; 320. a clamping portion; 321. clamping a screw; 322. a clamping piece; 323. locking a ring; 324. a locking washer; 325. a bearing ring; 326. an annular projection; 327. tightly pressing the ring; 328. locking screws; 330. locking the nut; 331. a butting ring; 340. a connecting spiro ring; 341. a rubber ring.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions under which the present invention can be implemented, so that the present invention has no technical significance, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms such as "upper", "lower", "left", "right" and "middle" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and changes or modifications of the relative relationship may be made without substantial technical changes.

As shown in fig. 1, fig. 2, fig. 4, fig. 6, fig. 7 and fig. 8, the present invention provides a two-stage electrical connector with multiple core wires, comprising a plug section 200 for electrically connecting with the core wires 110 of the cable 100 and a tail clamp section 300 for fixing the cable 100, wherein the plug section 200 is screwed with the tail clamp section 300; the plug section 200 comprises a plug section body 210 and a plug locking ring 220, wherein the plug locking ring 220 is sleeved on the outer peripheral surface of the plug section body 210; a plurality of welding pins 230 are arranged at one end of the plug section body 210 close to the tail clamp section 300; the tail clamp segment 300 includes a clamping portion 320 disposed at an end remote from the plug segment 200, and a connection tube 310 between the clamping portion 320 and the plug segment 200.

As shown in fig. 5 and 9, when the two-section electrical connector with multi-strand core wires is connected to the cable 100, the plug section 200 and the tail clamp section 300 are first removed by screwing, and after one end of the cable insulating sheath 120 is cut off from the cable 100, the core wires 110 of the cable 100 are welded to the welding pins 230 of the plug section 200, so that the cable 100 is initially fixed to the two-section electrical connector with multi-strand core wires; after the free end of the cable 100 is extended out through the port of the tail clamp section 300, the plug section 200 and the tail clamp section 300 are fixed by screw threads, and the cable 100 is further fixed by the clamping portion 320. The two-section type electric connector with the multi-strand core wire has the advantages of simple structure, simple and convenient manufacturing method, high production efficiency, lower cost, basically no pollution, firmness and reliability.

As shown in fig. 2, the plug section 200 and the tail clip section 300 are connected by a thread, wherein an external thread is arranged at one end of the tail clip section 300 close to the plug section 200, and a corresponding internal thread is arranged on the plug section 200; alternatively, as shown in fig. 7, the tail clip segment 300 and the plug segment 200 are connected by a connecting screw 340. Preferably, a rubber ring 341 may be further disposed at the abutment of the plug section 200 and the tail clip section 300 to increase the strength of the connection.

Further, the clamping portion 320 of the present application has two preferred embodiments, and there are two embodiments of the corresponding multi-strand two-segment electrical connector. Two preferred embodiments of the multi-strand two-piece electrical connector and clamp 320 are described below.

Two-section type electrical connector with multi-strand core wire

As shown in fig. 1 to 3, the clamping portion 320 according to the first embodiment of the present invention includes a clamping screw 321 and at least two arc-shaped clamping pieces 322, wherein the at least two arc-shaped clamping pieces 322 are connected end to end by the clamping screw 321. In this embodiment, the clamping portion 320 includes two arc-shaped clamping pieces 322, and the clamping tightness between the clamping pieces 322 and the cable 100 is adjusted by screwing the clamping screw 321. Preferably, the inner diameter of the connection pipe 310 is gradually reduced from an end near the plug section 200 toward an end of the clamping portion 320. This inner diameter is provided to facilitate passage of the cable 100 through the tail clamp segment 300 from the end near the plug segment 200 toward the clamping portion 320.

Two-section type electrical connector with multi-strand core wire

As shown in fig. 6 to 7, the clamping part 320 according to the second embodiment of the present invention includes a lock nut 330 threadedly coupled to the distal end of the connection pipe 310, and a lock ring 323 and a lock washer 324 disposed in the connection pipe 310; the locking ring 323 and the locking washer 324 are sequentially arranged along the axial direction of the connecting pipe 310, and the outer circumferential surfaces of the locking ring 323 and part of the locking washer 324 are both attached to the inner side surface of the connecting pipe 310; the end of the locking nut 330 remote from the connection tube 310 has an abutment ring 331 projecting radially inwards; one end of the locking washer 324 close to the abutting ring 331 is provided with a radially outward convex receiving ring 325 matched with the abutting ring; the coupling pipe 310 is provided with an annular protrusion 326 abutting against the locking ring 323.

In the second embodiment, the cable 100 may be stripped of the cable insulation 120 using the stripping method shown in fig. 8. After stripping the cable insulating sheath 120 and cutting off a section of the shielding layer 150, the cable 100 is exposed axially as the core wire 110, the shielding layer 150 and the cable insulating sheath 120 in that order. As shown in fig. 7 and 9, the cable 100 is wrapped with an electrical tape at one end from which the cable insulating sheath 120 is peeled off, thereby forming a protective tape layer 160. The protective tape layer 160 has a substantially conical tubular shape. Before the cable 100 is connected to the second embodiment, the locking nut 330 is loosened, and the locking nut 330 is moved in a direction away from the connecting tube 310, at which time, the annular protrusion 326 and the locking ring 323 are no longer in contact with each other, so that the protective tape layer 160 is placed between the annular protrusion 326 and the locking ring 323 when the cable 100 passes through the tail clip 300. Next, by tightening the lock nut 330, the lock washer 324 and the lock ring 323 are pushed, and the protective tape layer 160 is fixed in contact with the lock ring 323 by the annular protrusion 326. The locking ring 323 and the locking washer 324 are made of metal materials, which is beneficial to ensuring the shielding continuity of the cable 100.

Preferably, as shown in fig. 7 and 9, a pressing ring 327 is further disposed between the locking ring 323 and the locking washer 324, the pressing ring 327 is made of an elastic material, and an outer circumferential surface of the pressing ring 327 is attached to an inner side surface of the connection pipe 310. Generally, the compression ring 327 may be made of rubber. In the locking process, the electrical tape is wrapped on the corresponding position of the cable 100 to form the tape layer 180 for adjusting the diameter of the cable 100, so that the clamping ring 327 locks the cable 100.

As shown in fig. 4, fig. 5, fig. 8 and fig. 9, the present invention further provides a connection method of the two-segment electric connector with multiple core wires, which sequentially includes the following steps: 1) cutting off 2cm to 3cm of the cable insulation sheath 120 of the cable 100, straightening the core wire 110 of the cable 100, and stripping off 3-4 mm of the insulation layer on the core wire 110; sealing the end of the cable insulating sheath 120 remaining on the cable 100 with an electric tape to form a protective tape layer 160; 2) pre-sheathing an insulating sleeve 130 on the core wire 110 and a protective insulating heat shrink 140 on the cable 100 before the core wire 110 is welded with the welding pin 230; welding the core wire 110 with the welding pin 230; after the core wire 110 is welded with the welding needle 230, the insulation sleeve 130 is used for wrapping the exposed core wire 110 and the welding needle 230; 3) a grounding wire 170 is led out of the shielding layer 150 of the cable 100; 4) the protective insulating heat shrink 140 is connected to the inside of the connection tube 310 after heat shrinking, and the protective insulating heat shrink 140 is fixed by the clamping portion 320, and the tail clamp section 300 is partially exposed from the protective insulating heat shrink 140, and the ground wire 170 is grounded.

As shown in fig. 5 and 9, in step 1), the cut-off size of the cable insulating sheath 120 is only 2cm to 3cm, and the clamping portion 320 of the two-segment electrical connector is locked at the non-cut-off portion of the cable 100, so that the anti-seismic function of the electrical connector when being connected with the cable 100 is improved, and thus the core wire 110 of the cable 100 is protected from being easily broken under the condition that the ship is vibrating continuously, and the mechanical protection effect is achieved. If the number of the core wires 110 of the cable 100 is larger than that of the core wires 110 to be welded, the welding construction can not be performed according to the requirements, the cable insulating sheath 120 can be cut off according to the method, then the cable insulating sheath 120 is cut open in the longitudinal direction to a certain size, and after the core wires 110 are welded, the cut-open part is wound and restored by using the electric adhesive tape.

As shown in fig. 5 and 9, in step 3), the grounding line 170 is led out from the shielding layer 150 of the cable 100, so as to enhance the electromagnetic compatibility and meet the GJB grounding requirement. The grounding wire 170 is led out in two ways, the first way is to weld a wire on the shielding layer 150 to form the grounding wire 170 led out from the shielding layer 150; the second method is to pick out 3-8 strands of shielding layer 150 braided wires in the shielding layer 150, wrap the shielding layer 150 braided wires with an insulating heat-shrinkable sleeve, and then perform heat-shrinkable insulation to form the grounding wire 170 led out from the shielding layer 150. Wherein, the diameter of the grounding wire 170 is 3-4 mm. The length and form of the shield lead (i.e., ground wire 170) is determined by the field conditions, for example, as shown in fig. 5: the lead-out length may be about 8cm, and the ground wire 170 is an arc line with a radius of about 25mm, one end of the ground wire 170 is pressed against the cold press connector 171, and a heat shrink sleeve is sleeved on the insulation press connector, uniformly grounded nearby, and fixed on the clamping screw 321. The grounding wire 170 is as short as possible, and the plugging operation of the electric connector can be ensured, so that the uniformity and the beauty of the electric connector on the cabinet can be ensured,

preferably, in step 1), the core wire 110 is subjected to insulation removal using a cold stripping process. And stranding the stranded core wires 110 in the original stranding direction after the insulation removal, and carrying out tin coating treatment on the stranded core wires 110.

Specifically, the core wire 110 is removed by using a wire stripper or a wire stripping tool. Or, a thermal control wire stripper is used, the core wire 110 of the cable 100 is stripped by adopting a thermal stripping method, the specification of the thermal control wire stripper is matched with that of the core wire 110, the insulation skin cannot be burnt, and the color change length of the insulation skin cannot exceed 2 mm. The stranded core wires 110 are stranded in the original stranding direction, the stranding is uniform and straight, tin coating treatment is needed after the stranding, and tin coating treatment is needed for welding spots before welding of the electric connector. Electric powerThe electric connector of the cable 100 is welded by using a constant temperature electric iron, the corresponding temperature is selected according to the thickness of the core wire 110, the thin wire is set to 300 +/-10 ℃, and the thick wire is set to 350 +/-10 ℃. Wherein the inner diameter of the thin wire is less than 2.5mm²The inner diameter of the thick line is larger than 2.5mm². The protective insulating heat-shrinkable sleeve 140 is exposed out of the tail clamp by about 20mm, the clamping part 320 of the electric connector of the cable 100 is reliably fastened with the outer sheath of the cable 100, and the heat-shrinkable sleeve used in an area with a protection requirement needs to be tightly shrunk, so that the water tightness of the connection of the cable 100 is improved.

It should be noted that, when the multi-strand two-segment electrical connector is connected to the cable 100, the relevant work can be done in advance. For example, after the equipment cabinet is installed in the cabin or the equipment installation template is pre-installed, the cable 100 can be cut and wired. The cable 100 at the cabinet entrance should be left with the proper amount of telescoping and movement. In order to ensure the unity of the attractiveness of the cabin, wires, bridging grounding wires, IV lapping strips and the like used on an equipment cabinet and a chassis are gray; 1.5mm for use in an electrical connector²And 2.5mm²The two kinds of specification wires of (1); the bridging grounding wire and the lapping strip are black; the insulating rubberized fabric and the heat-shrinkable sleeve are black. The used heat-shrinkable sleeve is made of fireproof flame-retardant material and does not contain glue. The heat-shrinkable sleeve for wiring is of a non-adhesive type, and the heat-shrinkable sleeve for protection is of an adhesive type. The core insulating sleeve 130 uses a white flame-retardant plastic sleeve or a transparent heat-shrinkable sleeve.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A two segmentation electric connector of stranded heart yearn which characterized in that: the cable connector comprises a plug section (200) and a tail clamp section (300), wherein the plug section (200) is electrically connected with a core wire (110) of the cable (100), the tail clamp section (300) is used for fixing the cable (100), and the plug section (200) is in threaded connection with the tail clamp section (300); the plug section (200) comprises a plug section body (210) and a plug locking ring (220), and the plug locking ring (220) is sleeved on the outer peripheral surface of the plug section body (210); a plurality of welding pins (230) are arranged at one end of the plug section body (210) close to the tail clamp section (300); the tail clamp section (300) comprises a clamping part (320) arranged at one end far away from the plug section (200) and a connecting pipe (310) positioned between the clamping part (320) and the plug section (200).

2. The multi-strand core two-piece electrical connector of claim 1, wherein: the clamping part (320) comprises a clamping screw (321) and at least two arc-shaped clamping pieces (322), and the at least two clamping pieces (322) are connected end to end through the clamping screw (321).

3. The multi-strand core two-piece electrical connector of claim 1, wherein: the inner diameter of the connecting pipe (310) is gradually reduced from one end close to the plug section (200) to one end of the clamping part (320).

4. The multi-strand core two-piece electrical connector of claim 1, wherein: the clamping part (320) comprises a locking nut (330) which is screwed to the end of the connecting pipe (310), and a locking ring (323) and a locking washer (324) which are both arranged in the connecting pipe (310); the locking ring (323) and the locking gasket (324) are sequentially arranged along the axial direction of the connecting pipe (310), and the outer circumferential surfaces of the locking ring (323) and part of the locking gasket (324) are attached to the inner side surface of the connecting pipe (310); one end of the locking nut (330) far away from the connecting pipe (310) is provided with an abutting ring (331) protruding inwards in the radial direction; one end of the locking gasket (324) close to the abutting ring (331) is provided with a radially convex bearing ring (325) matched with the abutting ring (331); the connecting pipe (310) is provided with an annular bulge (326) which is abutted with the locking ring (323).

5. The multi-strand core two-piece electrical connector of claim 4, wherein: be provided with clamping ring (327) between locking ring (323) and locking gasket (324), this clamping ring (327) is made by elastic material, the outer periphery of clamping ring (327) with the medial surface laminating of connecting pipe (310).

6. A method of connecting a two-stage electrical connector with multiple cores as claimed in claim 1, wherein: the method sequentially comprises the following steps:

s1, cutting off 2cm to 3cm of a cable insulation sheath (120) of the cable (100), straightening a core wire (110) of the cable (100), and stripping off 3-4 mm of an insulation layer on the core wire (110); sealing the end of the remaining cable insulating sheath (120) on the cable (100) by using an electric adhesive tape to form a protective adhesive tape layer (160);

s2, pre-sheathing an insulating sleeve (130) on the core wire (110) and a protective insulating heat-shrinkable sleeve (140) on the cable (100) before the core wire (110) is welded with the welding needle (230); welding the core wire (110) with the welding needle (230); after the core wire (110) is welded with the welding needle (230), the exposed core wire (110) and the welding needle (230) are wrapped by the insulating sleeve (130);

s3, leading out a grounding wire (170) on a shielding layer (150) of the cable (100);

s4, connecting the protective insulating heat-shrinkable sleeve (140) into the connecting pipe (310) after heat-shrinking, fixing the protective insulating heat-shrinkable sleeve (140) by using the clamping part (320), exposing the tail clamping section (300) from the part of the protective insulating heat-shrinkable sleeve (140), and grounding the grounding wire (170).

7. The method of claim 6, wherein: in the step S1, the core wire (110) is removed by a cold peeling process.

8. The method of claim 7, wherein: and stranding a plurality of strands of the core wires (110) subjected to insulation removal according to the original stranding direction, and carrying out tin coating treatment on the stranded core wires (110).

9. The method of claim 6, wherein: in step S3, the ground line (170) is drawn in a manner: a wire is welded to the shield layer (150) to form a ground wire (170) led out from the shield layer (150).

10. The method of claim 6, wherein: in step S3, the ground line (170) is drawn in a manner: 3-8 strands of shielding layer braided wires are picked out from the shielding layer (150), and the shielding layer braided wires are wrapped by an insulating heat-shrinkable sleeve and then are subjected to heat-shrinkable insulation to form a grounding wire (170) led out from the shielding layer (150); the diameter of the grounding wire (170) is within 3-4 mm.