阅读说明：本技术 一种霍尔推力器用导线转接绝缘处理结构 (Wire switching insulation processing structure for Hall thruster ) 是由 扈延林 毛威 胡大为 周怡秋 沈岩 吴楠 秦宇 吴朋安 山世华 李胜军 臧娟伟 于 2019-09-16 设计创作，主要内容包括：一种霍尔推力器用导线转接绝缘处理结构,涉及航天器用电推进技术领域；包括2段小直径耐高温热缩管、大直径耐高温热缩管、单股线、多股线和导线焊接头；单股线的轴向一端伸入导线焊接头中；多股线的轴向一端从相对位置伸入导线焊接头中；单股线与多股线在导线焊接头内部焊接；其中1段小直径耐高温热缩管设置在单股线与导线焊接头连接处；另一段小直径耐高温热缩管设置在多股线与导线焊接头连接处；大直径耐高温热缩管依次套装在单股线、小直径耐高温热缩管、导线焊接头、小直径耐高温热缩管和多股线的外壁；本发明采用两种直径不同的耐高温热缩管实现了对导线转接处的绝缘处理,适用于高温条件下的绝缘处理。(A conducting wire switching insulation processing structure for a Hall thruster relates to the technical field of electric propulsion for spacecrafts; comprises 2 sections of small-diameter high-temperature-resistant heat-shrinkable tubes, large-diameter high-temperature-resistant heat-shrinkable tubes, single wires, stranded wires and wire welding heads; one axial end of the single-stranded wire extends into the wire welding head; one axial end of the stranded wire extends into the wire bonding head from the opposite position; the single-stranded wire and the multi-stranded wire are welded inside the wire welding head; wherein, 1 section of small-diameter high-temperature-resistant heat-shrinkable tube is arranged at the joint of the single-stranded wire and the lead welding head; the other section of small-diameter high-temperature-resistant heat-shrinkable tube is arranged at the joint of the stranded wire and the wire welding head; the large-diameter high-temperature-resistant heat-shrinkable tube is sequentially sleeved on the outer walls of the single-stranded wire, the small-diameter high-temperature-resistant heat-shrinkable tube, the wire welding head, the small-diameter high-temperature-resistant heat-shrinkable tube and the multi-stranded wire; the invention adopts two high temperature resistant heat shrink tubes with different diameters to realize the insulation treatment of the wire switching part, and is suitable for the insulation treatment under the high temperature condition.)

1. The utility model provides a hall is wire switching insulation processing structure for thruster which characterized in that: comprises 2 sections of small-diameter high-temperature-resistant heat-shrinkable tubes (1), large-diameter high-temperature-resistant heat-shrinkable tubes (2), single wires (3), stranded wires (4) and wire welding heads (5); wherein, the wire welding head (5) is of a cubic structure; one axial end of the single-stranded wire (3) extends into the wire welding head (5); one axial end of the stranded wire (4) extends into the wire welding head (5) from the opposite position; the single-stranded wire (3) and the multi-stranded wire (4) are welded inside the lead welding head (5); wherein 1 section of small-diameter high-temperature-resistant heat-shrinkable tube (1) is arranged at the joint of the single-stranded wire (3) and the wire welding head (5); and the small-diameter high-temperature-resistant heat-shrinkable tube (1) is sleeved on the outer wall of the single-stranded wire (3); the other section of small-diameter high-temperature-resistant heat-shrinkable tube (1) is arranged at the joint of the stranded wire (4) and the wire welding head (5); the small-diameter high-temperature-resistant heat-shrinkable tube (1) is sleeved on the outer wall of the stranded wire (4); the large-diameter high-temperature-resistant heat-shrinkable tube (2) is sequentially sleeved on the outer walls of the single-stranded wire (3), the small-diameter high-temperature-resistant heat-shrinkable tube (1), the wire welding head (5), the small-diameter high-temperature-resistant heat-shrinkable tube (1) and the stranded wire (4).

2. The conducting wire transfer insulation processing structure for the Hall thruster according to claim 1, wherein: the axial length of the small-diameter high-temperature-resistant heat-shrinkable tube (1) is 20-30 mm; the diameter of the inner wall is 3-3.4mm at room temperature.

3. The conducting wire transfer insulation processing structure for the Hall thruster according to claim 2, wherein: the axial length of the large-diameter high-temperature-resistant heat-shrinkable tube (2) is 70-80 mm; the diameter of the inner wall is 6.2-6.6mm at room temperature.

4. The conducting wire transfer insulation processing structure for the Hall thruster according to claim 3, wherein: the installation method of the insulation processing structure comprises the following steps:

firstly, stripping one axial end of a single-stranded wire (3); stripping one axial end of the stranded wire (4);

step two, sleeving a 1 section of small-diameter high-temperature-resistant heat-shrinkable tube (1) on the single-stranded wire (3) after wire stripping treatment; another 1 section of small-diameter high-temperature-resistant heat-shrinkable tube (1) is sleeved on the stranded wire (4) after the wire stripping treatment;

step three, respectively extending the single-stranded wire (3) subjected to wire stripping treatment and the multi-stranded wire (4) subjected to wire stripping treatment into a wire welding head (5), and welding the ends of the single-stranded wire (3) and the multi-stranded wire (4);

moving the small-diameter high-temperature-resistant heat-shrinkable tube (1) sleeved on the single-stranded wire (3) to the exposed wire core of the single-stranded wire (3); heating to shrink the small-diameter high-temperature-resistant heat-shrinkable tube (1);

moving the small-diameter high-temperature-resistant heat-shrinkable tube (1) sleeved on the stranded wires (4) to the exposed wire cores of the stranded wires (4); heating to shrink the small-diameter high-temperature-resistant heat-shrinkable tube (1);

step five, sleeving the large-diameter high-temperature-resistant heat-shrinkable tube (2) from the axial outer end of the stranded wire (4), and moving to the position covering the 2 small-diameter high-temperature-resistant heat-shrinkable tubes (1);

and step six, heating the large-diameter high-temperature-resistant heat-shrinkable tube (2) to realize heating shrinkage of the large-diameter high-temperature-resistant heat-shrinkable tube (2).

5. The conducting wire transfer insulation processing structure for the Hall thruster according to claim 4, wherein: in the first step, the length of the stripping wire of the single-stranded wire (3) is less than 5 mm; the length of the stripping wire of the stranded wires (4) is less than 5 mm.

6. The conducting wire transfer insulation processing structure for the Hall thruster according to claim 5, wherein: in the third step, the welding mode of the single-stranded wire (3) and the multi-stranded wire (4) is induction brazing.

7. The conducting wire transfer insulation processing structure for the Hall thruster according to claim 6, wherein: when the single-stranded wire (3) and the multi-stranded wire (4) are welded, the distance between the 2 sections of small-diameter high-temperature-resistant heat-shrinkable tubes (1) and a welding head is not less than 50 mm.

8. The conducting wire transfer insulation processing structure for the Hall thruster according to claim 7, wherein: in the fourth step, the heating temperature of the small-diameter high-temperature-resistant heat-shrinkable tube (1) corresponding to the single-stranded wire (3) is 300-350 ℃; the length of the exposed wire core of the single-stranded wire (3) covered by the small-diameter high-temperature-resistant heat-shrinkable tube (1) after heating is more than 10 mm; the heating temperature of the small-diameter high-temperature-resistant heat-shrinkable tube (1) corresponding to the stranded wire (4) is 300-350 ℃; the length of the small-diameter high-temperature-resistant heat-shrinkable tube (1) covering the exposed wire core of the stranded wire (4) after heating is more than 10 mm.

9. The conducting wire transfer insulation processing structure for the Hall thruster according to claim 8, wherein: in the fifth step, the length of the shaft end of the large-diameter high-temperature-resistant heat-shrinkable tube (2) covering the shaft end of the small-diameter high-temperature-resistant heat-shrinkable tube (1) is more than 10 mm.

10. The conducting wire transfer insulation processing structure for the hall thruster of claim 9, wherein: in the sixth step, the heating temperature of the large-diameter high-temperature-resistant heat-shrinkable tube (2) is 300-350 ℃; the outer walls of the single-stranded wire (3), the small-diameter high-temperature-resistant heat-shrinkable tube (1), the wire welding head (5), the small-diameter high-temperature-resistant heat-shrinkable tube (1) and the multi-stranded wire (4) are coated with the heated large-diameter high-temperature-resistant heat-shrinkable tube (2).

Technical Field

The invention relates to the technical field of electric propulsion for spacecrafts, in particular to a wire transfer insulation processing structure for a Hall thruster.

Background

The Hall thruster mainly comprises a hollow cathode, a discharge chamber, a magnetic pole, a magnetic coil, an anode/gas distributor, a propellant conveying pipeline and a supporting structure; the Hall propulsion technology can increase the effective load of the spacecraft, reduce the launching cost and prolong the service life, and is an effective means for improving the efficiency of commercial satellites and increasing the competitiveness in the future.

The Hall thruster comprises a hollow cathode, a discharge chamber, magnetic poles (comprising a front magnetic pole plate, a rear magnetic pole plate, an inner magnetic pole, an outer magnetic pole, an inner magnetic screen and an outer magnetic screen), an inner magnetic coil, an outer magnetic coil, an anode/gas distributor, a propellant conveying pipeline, a supporting structure and the like. The working principle is as follows: part of electrons emitted by the cathode enter the discharge chamber, drift towards the anode under the combined action of the orthogonal radial magnetic field and the axial electric field, and collide with neutral propellant atoms from the anode/gas distributor in the drift process, so that working medium atoms are ionized. Because of the existence of strong radial magnetic field, the jet-out is carried out at high speed along the axial direction under the action of the axial electric field, thereby generating thrust. Meanwhile, another part of electrons emitted by the cathode are neutralized with the axially ejected ions, and the macroscopic electric neutrality of the thruster plume is maintained.

The excitation wire in the Hall thruster is a single-strand wire, the single-strand wire cannot be directly connected with the electric connector, and the connection with the electric connector can be realized only by converting the single-strand wire into a multi-strand wire. Therefore, the problem of single-strand to multi-strand switching can be involved in the product implementation process. In the current implementation method, the switching is mainly implemented by an induction brazing method, that is, a single strand and a stranded strand are respectively inserted into a wire welding head, and then the switching is implemented by the induction brazing method. In this solution, it is necessary to first strip the single or multiple strands and then insert them into the wire bonding head made of metal. It can be seen that after the wire switching is completed, the wire is exposed. According to the design requirements of aerospace products, wires are required to be fixed, in a Hall thruster, the wires are usually fixed at the position of an accelerator base plate, and the accelerator base plate is also made of metal, so that the short circuit of a circuit is not guaranteed, and the exposed part at the switching position needs to be subjected to insulation treatment. Tests have shown that the temperature at the wire fixing position on the accelerator base plate is approximately between 200 ℃ and 250 ℃. The temperature requirements therefore need to be taken into account in the selection of the insulating material. There is currently no design that is relevant to achieve insulation at high temperatures,

disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a wire transfer insulation processing structure for a Hall thruster, which adopts two high-temperature-resistant heat-shrinkable tubes with different diameters to realize insulation processing of a wire transfer joint and is suitable for insulation processing under a high-temperature condition.

The above purpose of the invention is realized by the following technical scheme:

a conducting wire transfer insulation processing structure for a Hall thruster comprises 2 sections of small-diameter high-temperature-resistant heat-shrinkable tubes, large-diameter high-temperature-resistant heat-shrinkable tubes, single wires, stranded wires and conducting wire welding heads; wherein, the wire welding head is in a cubic structure; one axial end of the single-stranded wire extends into the wire welding head; one axial end of the stranded wire extends into the wire bonding head from the opposite position; the single-stranded wire and the multi-stranded wire are welded inside the wire welding head; wherein, 1 section of small-diameter high-temperature-resistant heat-shrinkable tube is arranged at the joint of the single-stranded wire and the lead welding head; and the section of small-diameter high-temperature-resistant heat-shrinkable tube is sleeved on the outer wall of the single-stranded wire; the other section of small-diameter high-temperature-resistant heat-shrinkable tube is arranged at the joint of the stranded wire and the wire welding head; the small-diameter high-temperature-resistant heat-shrinkable tube is sleeved on the outer wall of the stranded wire; the large-diameter high-temperature-resistant heat-shrinkable tube is sequentially sleeved on the outer walls of the single-stranded wire, the small-diameter high-temperature-resistant heat-shrinkable tube, the wire welding head, the small-diameter high-temperature-resistant heat-shrinkable tube and the multi-stranded wire.

In the above conducting wire transfer insulation processing structure for the hall thruster, the axial length of the small-diameter high-temperature-resistant heat-shrinkable tube is 20-30 mm; the diameter of the inner wall is 3-3.4mm at room temperature.

In the above wire transfer insulation processing structure for the hall thruster, the axial length of the large-diameter high-temperature-resistant heat-shrinkable tube is 70-80 mm; the diameter of the inner wall is 6.2-6.6mm at room temperature.

In the above conducting wire transfer insulation processing structure for the hall thruster, the installation method of the insulation processing structure is as follows:

firstly, stripping one axial end of a single-stranded wire; stripping one axial end of the stranded wire;

step two, sleeving a 1-section small-diameter high-temperature-resistant heat-shrinkable tube on the single-stranded wire subjected to wire stripping treatment; sleeving another 1 section of small-diameter high-temperature-resistant heat-shrinkable tube on the stripped multi-strand wire;

step three, respectively extending the single-stranded wire subjected to wire stripping treatment and the stranded wire subjected to wire stripping treatment into a wire welding head, and welding the ends of the single-stranded wire and the stranded wire;

moving the small-diameter high-temperature-resistant heat-shrinkable tube sleeved on the single-stranded wire to the exposed wire core of the single-stranded wire; heating to realize the shrinkage of the small-diameter high-temperature-resistant heat-shrinkable tube;

moving a small-diameter high-temperature-resistant heat-shrinkable tube sleeved on the stranded wires to the exposed wire cores of the stranded wires; heating to realize the shrinkage of the small-diameter high-temperature-resistant heat-shrinkable tube;

step five, sleeving the large-diameter high-temperature-resistant heat-shrinkable tube from the outer end of the multi-strand bobbin, and moving to the position covering the 2 small-diameter high-temperature-resistant heat-shrinkable tubes;

and step six, heating the large-diameter high-temperature-resistant heat-shrinkable tube to realize heating shrinkage of the large-diameter high-temperature-resistant heat-shrinkable tube.

In the above structure for conducting wire switching insulation processing for a hall thruster, in the first step, the length of a stripped wire of a single-stranded wire is less than 5 mm; the length of the stripping wire of the stranded wire is less than 5 mm.

In the aforementioned structure for conducting wire transferring insulation processing for a hall thruster, in the third step, the welding mode of the single-stranded wire and the multi-stranded wire is induction brazing.

In the above conducting wire transfer insulation processing structure for the hall thruster, when the single-stranded wire and the multi-stranded wire are welded, the distance between the 2 sections of small-diameter high-temperature-resistant heat-shrinkable tubes and the welding head is not less than 50 mm.

In the above conducting wire transfer insulation processing structure for the hall thruster, in the fourth step, the heating temperature of the small-diameter high-temperature-resistant heat-shrinkable tube corresponding to the single-stranded wire is 300-350 ℃; the length of the exposed wire core of the single-stranded wire covered by the small-diameter high-temperature-resistant heat-shrinkable tube after heating is more than 10 mm; the heating temperature of the small-diameter high-temperature-resistant heat-shrinkable tube corresponding to the stranded wire is 300-350 ℃; the length of the small-diameter high-temperature-resistant heat-shrinkable tube covering the exposed wire core of the stranded wires after heating is more than 10 mm.

In the above structure for conducting wire switching insulation processing for the hall thruster, in the fifth step, the length of the shaft end of the large-diameter high-temperature-resistant heat-shrinkable tube, which covers the shaft end of the small-diameter high-temperature-resistant heat-shrinkable tube, is greater than 10 mm.

In the wire transfer insulation processing structure for the Hall thruster, in the sixth step, the heating temperature of the large-diameter high-temperature-resistant heat-shrinkable tube is 300-350 ℃; and the heated large-diameter high-temperature-resistant heat-shrinkable tube is coated on the outer walls of the single-stranded wire, the small-diameter high-temperature-resistant heat-shrinkable tube, the wire welding head, the small-diameter high-temperature-resistant heat-shrinkable tube and the multi-stranded wire.

Compared with the prior art, the invention has the following advantages:

(1) the invention adopts two high temperature resistant heat shrink tubes with different diameters to realize the insulation treatment of the wire switching part; compared with the traditional technology, the reliability of insulation is improved;

(2) the high-temperature-resistant heat-shrinkable tube is selected, so that the high-temperature-resistant heat-shrinkable tube is conveniently fixed on the bottom plate of the accelerator with higher temperature; the insulation is realized at a higher working temperature, and the temperature requirement is considered under the condition of meeting the insulation requirement.

Drawings

FIG. 1 is a schematic view of a wire transfer insulation processing structure according to the present invention;

FIG. 2 is a schematic view of the position of a small-diameter high-temperature heat-shrinkable tube according to the present invention;

FIG. 3 is a schematic view of the position of the large-diameter high-temperature heat-shrinkable tube of the present invention.

Detailed Description

The invention is described in further detail below with reference to the following figures and specific examples:

the invention provides a conducting wire transfer insulation processing structure for a Hall thruster, which adopts two high-temperature-resistant heat-shrinkable tubes with different diameters to realize insulation processing on a conducting wire transfer joint and is suitable for insulation processing under a high-temperature condition; the device is suitable for a Hall thruster or other occasions requiring single-core wire to multi-core wire switching and with higher working temperature.

The insulation processing structure of the Hall thruster wire switching part mainly comprises 2 sections of small-diameter high-temperature-resistant heat-shrinkable tubes 1, a large-diameter high-temperature-resistant heat-shrinkable tube 2, a single wire 3, a stranded wire 4 and a wire welding head 5; wherein, the lead welding head 5 is a cubic structure; one axial end of the single-strand wire 3 extends into the wire welding head 5; one axial end of the stranded wire 4 extends into the wire bonding head 5 from the opposite position; the single-stranded wire 3 and the multi-stranded wire 4 are welded inside a wire welding head 5; wherein, 1 section of small-diameter high-temperature-resistant heat-shrinkable tube 1 is arranged at the joint of the single-stranded wire 3 and the lead welding head 5; and the section of small-diameter high-temperature-resistant heat-shrinkable tube 1 is sleeved on the outer wall of the single-stranded wire 3; the other section of small-diameter high-temperature-resistant heat-shrinkable tube 1 is arranged at the joint of the stranded wire 4 and the wire welding head 5; and the section of small-diameter high-temperature-resistant heat-shrinkable tube 1 is sleeved on the outer wall of the stranded wire 4; the large-diameter high-temperature-resistant heat-shrinkable tube 2 is sequentially sleeved on the outer walls of the single-stranded wire 3, the small-diameter high-temperature-resistant heat-shrinkable tube 1, the wire welding head 5, the small-diameter high-temperature-resistant heat-shrinkable tube 1 and the multi-stranded wire 4. Wherein, the axial length of the small-diameter high-temperature-resistant heat-shrinkable tube 1 is 20-30 mm; the diameter of the inner wall is 3-3.4mm at room temperature. The axial length of the large-diameter high-temperature-resistant heat-shrinkable tube 2 is 70-80 mm; the inner wall diameter at room temperature was 6.2-6.6mm as shown in FIG. 1.

The installation method of the insulation processing structure comprises the following steps:

firstly, stripping one axial end of a single-stranded wire 3; stripping one axial end of the stranded wire 4; the length of the stripping wire of the single-stranded wire 3 is less than 5 mm; the length of the wire stripping of the stranded wires 4 is less than 5 mm; the inner line connection of the single-stranded wire 3 and the multi-stranded wire 4 is realized; meanwhile, the exposed wire core is very small and has no potential danger of electric leakage and conduction; and the subsequent coating by adopting the small-diameter high-temperature-resistant heat-shrinkable tube 1 is simple to operate and complete in coating.

Step two, sleeving the 1 section of the small-diameter high-temperature-resistant heat-shrinkable tube 1 on the single-stranded wire 3 after the wire stripping treatment; sleeving the other 1 section of the small-diameter high-temperature-resistant heat-shrinkable tube 1 on the stranded wire 4 after the wire stripping treatment; the small-diameter high-temperature-resistant heat-shrinkable tube 1 is sleeved on the single-stranded wire 3 and the multi-stranded wire 4 which are exposed outside and used for insulating and protecting the wires.

Step three, respectively extending the single-stranded wire 3 subjected to wire stripping treatment and the multi-stranded wire 4 subjected to wire stripping treatment into a wire welding head 5, and welding the ends of the single-stranded wire 3 and the multi-stranded wire 4; the welding mode of the single-stranded wire 3 and the multi-stranded wire 4 is induction brazing. When the single-stranded wire 3 and the multi-stranded wire 4 are welded, the distance between the 2 sections of the small-diameter high-temperature-resistant heat-shrinkable tubes 1 and the welding head is not less than 50 mm. During welding, the 2 sections of the small-diameter high-temperature-resistant heat-shrinkable tubes 1 need to be far away from welding spots, so that the single-stranded wires 3 and the multi-stranded wires 4 are firmly welded, and the welding is not influenced by the small-diameter high-temperature-resistant heat-shrinkable tubes 1 during welding.

Moving the small-diameter high-temperature-resistant heat-shrinkable tube 1 sleeved on the single-stranded wire 3 to the exposed wire core of the single-stranded wire 3; heating to shrink the small-diameter high-temperature-resistant heat-shrinkable tube 1; the heating temperature of the small-diameter high-temperature-resistant heat-shrinkable tube 1 corresponding to the single-stranded wire 3 is 300-350 ℃; in the heating temperature range, the small-diameter high-temperature-resistant heat-shrinkable tube 1 has the fastest heat shrinkage change and the highest efficiency; meanwhile, the material change of the small-diameter high-temperature-resistant heat-shrinkable tube 1 is not influenced. The length of the heated small-diameter high-temperature-resistant heat-shrinkable tube 1 is required to cover all exposed parts of the sleeved wires; the length of the exposed wire core of the covered single-strand wire 3 is more than 10 mm; the insulation protection of the small-diameter high-temperature-resistant heat-shrinkable tube 1 to the single-stranded wire 3 is strictly ensured.

Moving the small-diameter high-temperature-resistant heat-shrinkable tube 1 sleeved on the stranded wires 4 to the exposed wire cores of the stranded wires 4; heating to shrink the small-diameter high-temperature-resistant heat-shrinkable tube 1; the heating temperature of the small-diameter high-temperature-resistant heat-shrinkable tube 1 corresponding to the stranded wire 4 is 300-350 ℃; in the heating temperature range, the small-diameter high-temperature-resistant heat-shrinkable tube 1 has the fastest heat shrinkage change and the highest efficiency; meanwhile, the material change of the small-diameter high-temperature-resistant heat-shrinkable tube 1 is not influenced; the length of the small-diameter high-temperature-resistant heat-shrinkable tube 1 covering the exposed wire core of the stranded wire 4 after heating is more than 10 mm. The small-diameter high-temperature heat-resisting heat-shrinkable tube 1 is strictly ensured to protect the multi-strand wires 4 in an insulating way, as shown in figure 2.

Step five, sleeving the large-diameter high-temperature-resistant heat-shrinkable tube 2 from the axial outer end of the stranded wire 4, and moving to cover the position of the 2 small-diameter high-temperature-resistant heat-shrinkable tubes 1; after moving, the length of the large-diameter high-temperature heat-resistant heat-shrinkable tube 2 is extended to cover the small-diameter high-temperature heat-shrinkable tube 1; the length of the shaft end of the large-diameter high-temperature-resistant heat-shrinkable tube 2 covering the shaft end of the small-diameter high-temperature-resistant heat-shrinkable tube 1 is more than 10 mm. Strictly ensuring the covering of the large-diameter high-temperature-resistant heat-shrinkable tube 2 on the small-diameter high-temperature-resistant heat-shrinkable tube 1; reliable secondary insulation protection is achieved as shown in fig. 3.

And step six, heating the large-diameter high-temperature-resistant heat-shrinkable tube 2 to realize heating shrinkage of the large-diameter high-temperature-resistant heat-shrinkable tube 2. The heating temperature of the large-diameter high-temperature-resistant heat-shrinkable tube 2 is 300-350 ℃; in the heating temperature range, the heat shrinkage of the large-diameter high-temperature-resistant heat-shrinkable tube 2 is changed fastest, and the efficiency is highest; meanwhile, the material change of the large-diameter high-temperature-resistant heat-shrinkable tube 2 is not influenced. The heated large-diameter high-temperature-resistant heat-shrinkable tube 2 is coated on the outer walls of the single-stranded wire 3, the small-diameter high-temperature-resistant heat-shrinkable tube 1, the wire welding head 5, the small-diameter high-temperature-resistant heat-shrinkable tube 1 and the multi-stranded wire 4.

All heating processes adopt a hot air gun to carry out heat shrinkage on each heat shrinkage pipe within a specified heat shrinkage temperature range of the heat shrinkage pipe; finally, the small-diameter high-temperature-resistant heat-shrinkable tube 1 needs to be in close contact with the single-stranded wire 3 or the multi-stranded wire 4 after being subjected to heat shrinkage, and cannot loosen or fall off; after being shrunk, the large-diameter high-temperature-resistant heat-shrinkable tube 2 needs to be in close contact with a wire welding head, a single-stranded wire 3 wrapped by the small-diameter high-temperature-resistant heat-shrinkable tube 1 after being shrunk and a multi-stranded wire 4 wrapped by the small-diameter high-temperature-resistant heat-shrinkable tube 1 after being shrunk, so that the wires cannot loosen and fall off.

The number of layers of the small-diameter high-temperature heat-resistant heat-shrinkable tube 1 and the large-diameter high-temperature heat-shrinkable tube 2 is more than or equal to 1.

Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.