CN117878698A - Cable butt joint process - Google Patents

Abstract

The invention relates to the technical field of cable butt joint, and provides a cable butt joint process, which comprises the following steps: stripping the connecting end of the first cable; stripping the connecting end of the second cable; reducing the second insulating shielding layer; a first heat shrinkage pipe and an intermediate joint are sleeved at the connecting end of the first cable in sequence, and a second heat shrinkage pipe is sleeved at the connecting end of the second cable; stripping a first core wire arranged on the inner side of the first insulating layer and a second core wire arranged on the inner side of the second insulating layer; straightening the first cable and the second cable, installing the first core wire and the second core wire in the connecting pipe, and crimping; wherein the first core wire is coincident with the second core wire; and moving the middle joint to the connecting pipe, and moving the first heat shrinkage pipe and the second heat shrinkage pipe to two ends of the middle joint for sealing. The invention can finish the butt joint of cables with different voltage levels without adding other extra infrastructures and infrastructures, and has small occupied area, convenient installation and maintenance and low cost.

Description

Cable butt joint process

Technical Field

The invention relates to the technical field of cable butt joint, in particular to a cable butt joint process.

Background

With the development of power systems, cables are widely used as important power transmission media in urban and rural power grids. In practical applications, it is often necessary to dock cables of different voltage levels to meet the power transmission and distribution requirements. However, the docking between the 64/110kV high voltage cable and the 26/35kV cable existing in the market faces a series of technical difficulties.

The insulation outer diameters of the two cables are obviously different, the conventional 35kV intermediate joint installation process method cannot meet the butt joint requirements between the two cables, the difficulty of field installation is increased, and potential threats are possibly caused to the safe operation of the cables. Meanwhile, the old cable system is replaced, so that the cost is high, and the waste of resources and the burden of the environment can be caused.

At present, a common solution is to connect through a cable butt joint box, and connect a 110kV high-voltage cable and a 35kV cable in the cable butt joint box through copper bars by adopting a 35kV cold-shrinkage indoor terminal product and a 110kV flexible dry-type outdoor terminal product. But adopts the butt joint case to connect, and project material cost is higher, has increased holistic investment burden. After the installation is completed, the whole ground space occupied by the cable butt joint box is larger, and the cable butt joint box is a small challenge for environments with limited space such as cities. In addition, the construction difficulty of the installer is high, and professional skills and abundant experience are required. Meanwhile, a cement foundation is also required to be built for placing the cable butt joint box, so that the construction cost and difficulty are further increased. In addition, once the cable butt joint box fails, the maintenance cost is quite high, and no small pressure is brought to the stable operation of the power system.

Disclosure of Invention

The invention provides a cable butt joint process which is used for solving the problems of high installation difficulty and high cost in the prior art when cables with different voltage levels are in butt joint.

The invention provides a cable butt joint process, wherein the voltage of a first cable is smaller than that of a second cable, and the diameter of the first cable is smaller than that of the second cable; the cable butt joint process comprises the following steps: stripping the connecting end of the first cable, wherein the first cable is exposed from a first insulating layer, a first insulating shielding layer, a first semiconducting layer, a metal shielding layer, an inner protecting layer, an armor layer and a first outer protecting layer which are arranged outside; stripping the connecting end of the second cable, wherein the second cable is exposed from the inside to the outside by a second insulating layer, a second insulating shielding layer, a second semiconductive layer, an aluminum sheath and a second outer protective layer; reducing the second insulating shielding layer; a first heat shrinkage pipe and an intermediate joint are sleeved at the connecting end of the first cable in sequence, and a second heat shrinkage pipe is sleeved at the connecting end of the second cable; stripping a first core wire arranged on the inner side of the first insulating layer and a second core wire arranged on the inner side of the second insulating layer; straightening the first cable and the second cable, installing the first core wire and the second core wire in a connecting pipe, and crimping; wherein the first core wire coincides with the second core wire; and moving the middle joint to the connecting pipe, and moving the first heat shrinkage pipe and the second heat shrinkage pipe to two ends of the middle joint for sealing.

According to the cable butt joint process provided by the invention, the reducing treatment is carried out on the second insulating shielding layer, and then the cable butt joint process further comprises the following steps: cleaning along the second insulating layer toward the second insulating shield layer; and spraying semiconductive paint on the reducing section to form a semiconductive shielding layer.

According to the cable butt joint process provided by the invention, the length of the first core wire and the length of the second core wire are stripped and are the sum of half of the connecting pipe and a preset distance.

According to the cable butt joint process provided by the invention, the cable butt joint process further comprises the following steps: and polishing the outer wall surface of the connecting pipe, wherein two ends of the connecting pipe are respectively in transitional connection with the first insulating layer and the second insulating layer.

According to the cable butt joint process provided by the invention, the cable butt joint process further comprises the following steps: and winding a first semi-conductive belt on the outer wall surface of the connecting pipe, wherein the outer diameter of the first semi-conductive belt is the same as the outer diameters of the first insulating layers and the second insulating layers at the two sides.

According to the cable butt joint process provided by the invention, the intermediate joint is moved to the connecting pipe, and then the cable butt joint process further comprises the following steps: and the two ends of the middle joint are respectively wound with a first waterproof insulating tape, and the two ends of the middle joint are respectively in transitional connection with the first insulating layer and the second insulating layer through the first waterproof insulating tape.

According to the cable butt joint process provided by the invention, the cable butt joint process further comprises the following steps: winding a second semiconducting tape along an insulating section of the intermediate joint towards the metallic shielding layer, the second semiconducting tape overlapping the metallic shielding layer; and winding the second semi-conductive tape along the second insulating layer towards the aluminum sheath, wherein the second semi-conductive tape is overlapped with the aluminum sheath.

According to the cable butt joint process provided by the invention, the cable butt joint process further comprises the following steps: and the outer wall surface of the second semi-conductive belt is respectively wound with a metal shielding net, the metal shielding net positioned on the first cable section is fixed with the inner protective layer, and the metal shielding net positioned on the second cable section is fixed with the aluminum sheath.

According to the cable butt joint process provided by the invention, the cable butt joint process further comprises the following steps: and winding metal wires on the outer wall surface of the metal shielding net, wherein the metal wires positioned on the first cable section are connected with the armor layer, and the metal wires positioned on the second cable section are connected with the aluminum sheath.

According to the cable butt joint process provided by the invention, the cable butt joint process further comprises the following steps: and winding a second waterproof insulating tape between the first outer protective layer and the second outer protective layer, wherein two ends of the second waterproof insulating tape are respectively overlapped with the first outer protective layer and the second outer protective layer.

According to the cable butt joint process provided by the invention, only the first cable and the second cable are required to be processed, and the butt joint of cables with different voltage levels can be completed without adding other extra infrastructures and infrastructures, so that the cable butt joint process has the advantages of small occupied area, convenience in installation and maintenance and low cost.

Drawings

In order to more clearly illustrate the invention or the technical solutions of the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the invention, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic flow chart of a cable docking process provided by the invention;

fig. 2 is a schematic structural view of a first cable after being processed according to the present invention;

fig. 3 is a schematic structural diagram of a second insulation shielding layer of a second cable after diameter-changing treatment;

fig. 4 is a schematic structural diagram of the second cable provided by the invention after the variable diameter section is sprayed with the semiconductor paint;

fig. 5 is a schematic structural diagram of the first cable and the second cable before being butted;

fig. 6 is a schematic structural view of a first cable and a second cable connected by a connecting pipe according to the present invention;

FIG. 7 is a cross-sectional view of an intermediate connector provided by the present invention mounted to a cable junction;

fig. 8 is a schematic structural view of the present invention in which first waterproof insulating tapes are wound around both ends of the intermediate joint;

FIG. 9 is a schematic view of the structure of the first and second cable recovery semiconductive layers provided by the present invention;

FIG. 10 is a schematic view of the structure of the first and second cables of the present invention with the metallic shield layer restored;

FIG. 11 is a schematic view of the structure of the first and second cables of the present invention for restoring the outer jacket;

fig. 12 is a schematic structural view of a protective shell provided at a joint of a first cable and a second cable according to the present invention;

reference numerals:

1. a first cable; 1a, a first core wire; 1b, a first insulating layer; 1c, a first insulating shielding layer; 1d, a first semiconductive layer; 1e, a metal shielding layer; 1f, an inner protective layer; 1g, armor layer; 1h, a first outer protective layer;

2. a second cable; 2a, a second core wire; 2b, a second insulating layer; 2c, a second insulating shielding layer; 2d, a second semiconductive layer; 2e, an aluminum sheath; 2f, a second outer protective layer; 2g, a semiconductive shielding layer;

3. a connecting pipe; 4. an intermediate joint; 5. a first heat shrinkage tube; 6. a second heat shrinkage tube; 7. a first semiconducting tape; 8. a second semiconductive belt; 9. a first waterproof insulating tape; 10. a second waterproof insulating tape; 11. a metal shielding net; 12. a wire; 13. and a protective shell.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In describing embodiments of the present invention, it should be noted that, unless explicitly stated and limited otherwise, the terms "coupled," "coupled," and "connected" should be construed broadly, and may be either a fixed connection, a removable connection, or an integral connection, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in embodiments of the present invention will be understood in detail by those of ordinary skill in the art.

In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the embodiments of the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

The following disclosure provides many different embodiments, or examples, for implementing different structures of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the applicability of other processes and/or the use of other materials.

A cable docking process provided by the present invention is described below with reference to fig. 1 to 12.

The cable butt joint refers to two kinds of cable butt joint, wherein the two kinds of cables are a first cable 1 and a second cable 2 respectively, the voltage of the first cable 1 is smaller than that of the second cable 2, the diameter of the first cable 1 is smaller than that of the second cable 2, for example, the first cable 1 is a 26/35kV cable, the second cable 2 is a 64/110KV cable, and the outer diameter of the second cable 2 is smaller than that of the first cable 1.

Referring to fig. 1, a cable docking process provided by an embodiment of the present invention includes: step 100, stripping the connection end of the first cable 1, wherein the first cable 1 is exposed from the first insulating layer 1b, the first insulating shielding layer 1c, the first semiconductive layer 1d, the metal shielding layer 1e, the inner protecting layer 1f, the armor layer 1g and the first outer protecting layer 1h which are arranged from outside; stripping the connection end of the second cable 2, wherein the second cable 2 is exposed from inside to outside by a second insulating layer 2b, a shielding layer of the second insulating layer 2b, a second semiconductive layer 2d, an aluminum sheath 2e and a second outer protective layer 2 f; step 200, performing reducing treatment on the second insulation shielding layer 2 c; step 300, sequentially sleeving a first heat shrinkage tube 5 and an intermediate joint 4 at the connection end of a first cable 1, and sleeving a second heat shrinkage tube 6 at the connection end of a second cable 2; step 400 of stripping the first core wire 1a provided inside the first insulating layer 1b and the second core wire 2a provided inside the second insulating layer 2 b; step 500, straightening the first cable 1 and the second cable 2, installing the first core wire 1a and the second core wire 2a in the connecting pipe 3, and crimping; wherein the first core wire 1a coincides with the second core wire 2a; and 600, moving the middle joint 4 to the connecting pipe 3, and moving the first heat shrinkage pipe 5 and the second heat shrinkage pipe 6 to two ends of the middle joint 4 for sealing.

Referring to fig. 2 and 5, the first cable 1 is provided with a first core wire 1a, a first insulating layer 1b, a first insulating shield layer 1c, a first semiconductive layer 1d, a metal shield layer 1e, an inner sheath 1f, an armor layer 1g, and a first outer sheath 1h in this order from inside to outside. The first cable 1 is stripped to expose the first insulating layer 1b, the first insulating shielding layer 1c, the first semiconductive layer 1d, the metal shielding layer 1e, the inner sheath 1f, the armor layer 1g and the first outer sheath 1h, for example, the length of stripping the first outer sheath 1h is 700mm, the length of the first insulating layer 1b is 195mm, and the length of the first insulating shielding layer 1c is 55mm, and specifically stripping can be performed according to practical situations.

When the first outer sheath 1h and the inner sheath 1f are peeled off, 240# sandpaper may be used and cleaned. When the first semiconductive layer 1d is peeled off, care should be taken not to scratch the first insulating shielding layer 1c, and the sharp angle can be removed by polishing with 240# sand paper and 400# sand paper at the fracture of the first semiconductive layer 1d in order to make the first semiconductive layer 1d and the first insulating shielding layer 1c smoothly transition.

After the first cable 1 is stripped, a semi-conductive tape is adopted between the metal shielding layer 1e and the first semi-conductive layer 1d to wind the transition part of the metal shielding layer 1e and the first semi-conductive layer 1d, the semi-conductive tape is lapped with the first semi-conductive layer 1d to be not less than 10mm, the semi-conductive tape is lapped with the metal shielding layer 1e to be not less than 20mm, the first semi-conductive layer 1d is fixed, and the conduction of the first semi-conductive layer is ensured.

Referring to fig. 3 and 5, the second cable 2 is sequentially provided with a second core wire 2a, a second insulating layer 2b, a second insulating shielding layer 2c, a second semiconductive layer 2d, an aluminum sheath 2e and a second outer sheath 2f from inside to outside, wherein the aluminum sheath 2e corresponds to a metal shielding layer, an inner sheath and an armor layer of the second cable 2. The second cable 2 is stripped to expose the aluminum sheath 2e, the second semiconductive layer 2d, the second insulating shield 2c, and the second insulating layer 2 b.

Step 200, performing reducing treatment on the second insulation shielding layer 2 c; after the second semiconductive layer 2d is peeled off, the second insulating shield layer 2c is exposed; a certain length is taken from the end of the second cable 2 for diameter-changing treatment, for example, 235mm is measured, and the fracture of the second insulation shielding layer 2c and the second insulation layer 2b are smoothly transited, that is, the outer diameter of the second insulation layer 2b gradually increases towards the direction of the second insulation shielding layer 2c, and the second insulation shielding layer 2c at this time becomes the second insulation layer 2b as shown in fig. 3.

The reducing treatment can be carried out by adopting a polishing mode, after polishing, the second insulating layer 2b and the second insulating shielding layer 2c are wiped by adopting cable cleaning paper, and the surface of the second insulating layer 2b is blow-dried and inspected by using an electric hair drier, so that no spots and flaws are ensured. During the wiping, the wiping direction is wiped by the second insulating layer 2b toward the second insulating shield layer 2c, preventing the conductive particles from being brought onto the second insulating layer 2 b.

Further, a semiconductive paint is sprayed on the diameter-variable section to form a semiconductive shield layer 2g, as shown in fig. 4.

Firstly, a PVC adhesive tape is used for wrapping a place which is not required to be sprayed on the first insulating shielding layer 1c, four points are measured at the top position of the paint along the circumference at least, and the plane of the side line of the semiconductor paint is vertical to the axis of the second cable 2.

Opening a paint pot, heating the paint by using an electric hair drier before painting, uniformly coating the semi-conductive paint on the reducing section after the viscosity of the paint is reduced, and drying the surface of the semi-conductive paint by using the electric hair drier. Cycling for a plurality of times, and requiring the surface of the semi-conductive paint to be smooth and flat; and the PVC tape is torn off in the direction of the core wire of the second cable 2, requiring that the semiconductive paint not be detached. And then the electric hair drier is adopted again to heat and vulcanize the semi-conductive paint, so that the surface of the semi-conductive paint is smooth and flat, and has no dust, bulges and defects. At this time, the diameter-variable section after the spraying of the semiconductive paint forms a semiconductive shield layer 2g similar to the second insulating shield layer 2c, i.e., the second shield layer 2c is recovered.

Step 300, a first heat shrinkage tube 5 and an intermediate joint 4 are sleeved at the connection end of the first cable 1 in sequence, and a second heat shrinkage tube 6 is sleeved at the connection end of the second cable 2, as shown in fig. 5.

In step 400, the first insulating layer 1b is peeled off to expose the first core wire 1a located inside the first insulating layer 1b, and the second insulating layer 2b is peeled off to expose the second core wire 2a located inside the second insulating layer 2 b.

Wherein, the length of the first core wire 1a and the length of the second core wire 2a are the sum of half of the connecting pipe 3 and the preset distance, the preset distance is 3-5mm, such as 3mm, 4mm and 5mm, and the preset distance is the overlapping length of the first core wire 1a and the second core wire 2a, which is helpful for the butt joint of the first core wire 1a and the second core wire 2 a.

Step 500, aligning the first cable 1 and the second cable 2, installing the first core wire 1a and the second core wire 2a in the connecting pipe 3, wherein the first core wire 1a and the second core wire 2a are overlapped by 3-5mm, and crimping, so that the first core wire 1a, the second core wire 2a, the first insulating layer 1b, the second insulating layer 2b and the connecting pipe 3 are crimped into a whole, and the connection of the first core wire 1a and the second core wire 2a and the connection of the first insulating layer 1b and the second insulating layer 2b are realized.

After the crimping is completed, the outer wall surface of the connecting pipe 3 is polished, and two ends of the connecting pipe 3 are respectively in transitional connection with the first insulating layer 1b and the second insulating layer 2b, so that the occurrence of tip discharge is avoided.

Specifically, burrs on the outer wall surface of the connecting pipe 3 are leveled, and can be polished to be flat by adopting sand paper, so that point discharge is eliminated; wherein the connecting pipe 3 is in transitional connection with the first insulating layer 1b, and a chamfer angle of 3X 45 degrees can be formed at the transitional part by polishing and the polishing is smooth; likewise, the connecting pipe 3 is in transitional connection with the second insulating layer 2b, and the transitional part can be polished to form a chamfer angle of 3X 45 degrees and smooth; and then cleaned.

The center line of the connecting pipe 3 in the length direction is determined and marked, and an installation auxiliary base line and an installation checking line are made on the second cable 2 according to the size of the intermediate joint 4, as shown in fig. 6, and a PVC glue can be used for illustration.

The first semiconducting tape 7 is wound around the outer wall surface of the connection pipe 3, and the outer diameter of the first semiconducting tape 7 is the same as the outer diameters of the first insulating layer 1b and the second insulating layer 2b on both sides, as shown in fig. 6. The connecting pipe 3 is a conductive connecting pipe, and after the connecting pipe 3 is in compression joint, the surface of the connecting pipe 3 is not smooth, the outer wall surface of the connecting pipe 3 can be smooth by winding the first semi-conductive tape 7, the outer diameter of the wound first semi-conductive tape 7 is the same as that of the first insulating layer 1b and the second insulating layer 2b, and an intermediate connector (cold shrink connector) is conveniently arranged on a section of equal-diameter cable.

The first insulating layer 1b and the second insulating layer 2b are wiped by adopting the cable cleaning paper, any metal powder and conductive substances cannot be remained, a small amount of silicone grease is uniformly smeared on the first insulating layer 1b and the second insulating layer 2b after the cleaning agent is sent out, so that not only can tiny gaps be filled, but also an insulating effect can be achieved, and the installation of the intermediate connector 4 is facilitated.

The intermediate head 4 can be quickly moved to the connection pipe 3 by the silicone grease, wherein the center of the intermediate head 4 coincides with the center of the connection pipe 3, as shown in fig. 7. The intermediate joint 4 includes a cold shrink joint, and during the movement, the cold shrink joint can be rotated while pulling out the support bar (the direction of stretching is shown by the arrow in fig. 5) to tighten it. When the cold shrink joint is contracted to half, the support bar is required to be drawn out, the distance between the cold shrink joint and the installation checking line is measured, the size is checked, and if the deviation exists, the cold shrink joint is immediately pushed to the correct position.

After the installation is completed, the first cable 1 and the second cable 2 are wiped. And the first heat shrinkage tube 5 and the second heat shrinkage tube 6 are moved to both ends of the intermediate joint 4, and both ends of the intermediate joint 4 are sealed by heating.

According to the cable butt joint process provided by the embodiment of the invention, the first cable 1 and the second cable 2 are only required to be processed, and the butt joint of cables with different voltage levels can be completed without adding other extra infrastructures and infrastructures, so that the occupied area is small, the installation and the maintenance are convenient, and the cost is low.

In the embodiment of the present invention, the intermediate joint 4 is moved to the connecting pipe 3, and then further includes: the first waterproof insulating tapes 9 are respectively wound at the two ends of the intermediate joint 4, and the two ends of the intermediate joint 4 are respectively in transitional connection with the first insulating layer 1b and the second insulating layer 2b through the first waterproof insulating tapes 9.

Referring to fig. 8, first waterproof insulating tapes 9 are wound around both ends of the intermediate connector 4, the intermediate connector 4 is in transitional connection with the first semiconductive layer 1d through the first waterproof insulating tapes 9, and the intermediate connector 4 is in transitional connection with the semiconductive shielding layer 2g through the first waterproof insulating tapes 9, so that water blocking layers are formed at both ends of the intermediate connector 4, and sealing effect is improved.

The cable butt joint process provided by the embodiment of the invention further comprises the following steps: winding a second semiconducting tape 8 along the insulating section of the intermediate joint 4 towards the metallic shielding layer 1e, the second semiconducting tape 8 overlapping the metallic shielding layer 1 e; a second semiconducting tape 8 is wound along the second insulating layer 2b towards the aluminium sheath 2e, the second semiconducting tape 8 overlapping the aluminium sheath 2 e.

Referring to fig. 9, an insulating section (grey section in fig. 9) is provided at one end of the intermediate connector 4 near the second cable 2, a second semiconducting tape 8 is wound along the insulating section of the intermediate connector 4 near the end of the first cable 1 (at a distance, e.g. 5mm, from the end of the insulating section) towards the metallic shielding layer 1e of the first cable 1, the second semiconducting tape 8 overlapping the metallic shielding layer 1e of the first cable 1, possibly by 30mm, so as to recover the first semiconducting layer 1d.

The second semiconducting tape 8 is wound along the insulating section of the intermediate joint 4 near the end of the second cable 2 (at a distance, e.g. 5mm, from the end of the insulating section) towards the aluminium sheath 2e of the second cable 2, the second semiconducting tape 8 overlapping the aluminium sheath 2e, possibly by 30mm, so as to recover the second semiconducting layer 2d.

The cable butt joint process of the embodiment of the invention further comprises the following steps: the metal shielding net 11 is wound on the outer wall surface of the semiconductive belt, the metal shielding net 11 positioned at the first cable 1 section is fixed with the inner protective layer 1f, and the metal shielding net 11 positioned at the second cable 2 section is fixed with the aluminum protective layer 2 e.

Referring to fig. 10, between the first cable 1 and the intermediate joint 4, a metal shielding mesh 11, such as a copper shielding mesh, is wound around the inner sheath 1f of the first cable 1 in a half lap manner starting at the starting end 5mm of the outer wall surface of the second semiconductive tape 8, and is fixed with the inner sheath 1f with a fixing member (such as a constant force spring), thereby restoring the metal shielding layer 1e of the first cable 1.

Between the second cable 2 and the intermediate joint 4, a metal shielding mesh 11, such as a copper shielding mesh, is wound around the starting end 5mm of the outer wall surface of the second semiconductive tape 8, and the copper shielding mesh is wrapped around the aluminum sheath 2e of the second cable 2 in a half lap manner and fixed with the inner sheath 1f by a fixing member (such as a constant force spring), thereby restoring the metal shielding layer 1e of the second cable 2.

The cable butt joint process of the embodiment of the invention further comprises the following steps: the wires 12 are wound on the outer wall surface of the metal shielding net 11, the wires 12 positioned on the first cable 1 section are connected with the armor layer 1g through a fixing piece (such as a constant force spring), the wires 12 positioned on the second cable 2 section are connected with the aluminum sheath 2e through a fixing piece (such as a constant force spring), and therefore the armor layer 1g of the first cable 1 and the armor layer 1g of the second cable 2 are restored.

The aluminum sheath 2e of the second cable 2 is an aluminum sheath 2e with peaks and valleys, a certain length of the aluminum sheath 2e is taken, for example, 120mm, asphalt on the surface of the aluminum sheath 2e and an oxide layer between the peaks and valleys are removed, aluminum welding rods or lead welding rods are filled between the peaks and valleys, and bottom-lining lead is carried out to form a plane, so that the metal shielding net 11 and the metal wires 12 are fixed on the aluminum sheath 2e through fixing pieces.

Further, sealant is coated at the connection part of the metal wire 12 and the constant force spring and at the fracture parts of the first outer protection layer 1h and the second outer protection layer 2f, so that fixation is realized, and a sealing effect is realized, and red parts in fig. 11 and 12 are schematic positions of the sealant.

The cable butt joint process of the embodiment of the invention further comprises the following steps: a second waterproof insulating tape 10 is wound between the first outer sheath 1h and the second outer sheath 2f, and both ends of the second waterproof insulating tape 10 are respectively overlapped with the first outer sheath 1h and the second outer sheath 2f, and the overlapped length may be 30mm, thereby completing the restoration of the first outer sheath 1h and the second outer sheath 2f, as shown in fig. 11.

The cable butt joint process of the embodiment of the invention further comprises wrapping an armor tape and a heat shrinkage tube on the outer wall surface of the waterproof insulating tape, or adding a protective shell 13 such as a glass fiber reinforced plastic shell and an aluminum magnesium alloy protective shell 13, and the like, as shown in fig. 12, so as to enhance the sealing waterproof or flame-retardant explosion-proof function of the reducing butt joint intermediate joint 4. In addition, both ends of the protective case 13 may be reinforced with heat shrink tubing to seal.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A cable docking process, characterized in that the voltage of a first cable is smaller than the voltage of a second cable, the diameter of the first cable is smaller than the diameter of the second cable; the cable butt joint process comprises the following steps:

stripping the connecting end of the first cable, wherein the first cable is exposed from a first insulating layer, a first insulating shielding layer, a first semiconducting layer, a metal shielding layer, an inner protecting layer, an armor layer and a first outer protecting layer which are arranged outside; stripping the connecting end of the second cable, wherein the second cable is exposed from the inside to the outside by a second insulating layer, a second insulating shielding layer, a second semiconductive layer, an aluminum sheath and a second outer protective layer;

reducing the second insulating shielding layer;

a first heat shrinkage pipe and an intermediate joint are sleeved at the connecting end of the first cable in sequence, and a second heat shrinkage pipe is sleeved at the connecting end of the second cable;

stripping a first core wire arranged on the inner side of the first insulating layer and a second core wire arranged on the inner side of the second insulating layer;

straightening the first cable and the second cable, installing the first core wire and the second core wire in a connecting pipe, and crimping; wherein the first core wire coincides with the second core wire;

and moving the middle joint to the connecting pipe, and moving the first heat shrinkage pipe and the second heat shrinkage pipe to two ends of the middle joint for sealing.

2. The cable docking process according to claim 1, wherein the reducing process is performed on the second insulating shield layer, and further comprising:

cleaning along the second insulating layer toward the second insulating shield layer;

and spraying semiconductive paint on the reducing section to form a semiconductive shielding layer.

3. The cable docking process according to claim 1, wherein the length of the stripped first core wire and the length of the second core wire are both the sum of half of the connection pipe and a preset distance.

4. The cable docking process of claim 1, further comprising:

and polishing the outer wall surface of the connecting pipe, wherein two ends of the connecting pipe are respectively in transitional connection with the first insulating layer and the second insulating layer.

5. The cable docking process of claim 4, further comprising:

and winding a first semi-conductive belt on the outer wall surface of the connecting pipe, wherein the outer diameter of the first semi-conductive belt is the same as the outer diameters of the first insulating layers and the second insulating layers at the two sides.

6. The cable docking process of claim 1, wherein moving the intermediate joint to the connection tube, further comprises:

and the two ends of the middle joint are respectively wound with a first waterproof insulating tape, and the two ends of the middle joint are respectively in transitional connection with the first insulating layer and the second insulating layer through the first waterproof insulating tape.

7. The cable docking process of claim 6, further comprising: winding a second semiconducting tape along an insulating section of the intermediate joint towards the metallic shielding layer, the second semiconducting tape overlapping the metallic shielding layer; and winding the second semi-conductive tape along the second insulating layer towards the aluminum sheath, wherein the second semi-conductive tape is overlapped with the aluminum sheath.

8. The cable docking process of claim 7, further comprising: and the outer wall surface of the second semi-conductive belt is respectively wound with a metal shielding net, the metal shielding net positioned on the first cable section is fixed with the inner protective layer, and the metal shielding net positioned on the second cable section is fixed with the aluminum sheath.

9. The cable docking process of claim 7, further comprising: and winding metal wires on the outer wall surface of the metal shielding net, wherein the metal wires positioned on the first cable section are connected with the armor layer, and the metal wires positioned on the second cable section are connected with the aluminum sheath.

10. The cable docking process of claim 7, further comprising: and winding a second waterproof insulating tape between the first outer protective layer and the second outer protective layer, wherein two ends of the second waterproof insulating tape are respectively overlapped with the first outer protective layer and the second outer protective layer.