Efficient protection polyethylene special power cable

Abstract

The invention discloses an efficient protection polyethylene special power cable which comprises two cable bodies and a connection protection device. The power cable is provided with a plurality of coating pipes, so that the insulation and flame-retardant effects can be well realized, and better roundness and support of the flame-retardant coating pipes are realized due to the support part and the coating part. And the gaps in the inner protection tube can be filled by injecting epoxy resin glue, so that the cable connection position can achieve a better insulation effect after the epoxy resin glue is cured, and no gap exists in the cable connection position. Through the arrangement of the double-layer protection pipe of the inner protection pipe and the outer protection pipe, the connection position is better protected, the epoxy resin between the inner protection pipe and the outer protection pipe achieves better sealing protection, and the water blocking particles between the first end sealing unit and the second end sealing unit achieve better water blocking.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and more specifically, to a high-efficiency protective polyethylene special power cable. Background Technology

[0002] Special power cables, designed to meet the operational requirements of complex and harsh environments, typically employ a multi-layered composite design. From the inside out, they generally include a conductor, conductor shield, insulation layer, insulation shield, metallic shield, water-blocking layer, and sheath layer. This multi-layered structure ensures the overall electrical insulation, flame retardancy, water resistance, and mechanical protection of the cable.

[0003] When the length of a single cable is insufficient for the required length, two cables are often connected using a connector. Currently, the industry commonly employs a "step-by-step, layer-by-layer" approach, which has fundamental flaws. After electrically connecting the conductors of the cable bodies, layers of sheathing are needed to cover the cable core, such as with cable wrapping tape or heat-shrink tubing. However, this structure is still largely flexible, lacking a rigid protective shell, thus providing insufficient protection at the connection point. Furthermore, due to gaps between the layers and the lack of filler, the insulation layer and conductor are not tightly wrapped, and these gaps also lead to insufficient water resistance. Therefore, the traditional layer-by-layer sheathing method provides inadequate protection at the connection point of the two cable bodies. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art and provide a high-efficiency protective polyethylene special power cable.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a power cable, comprising two cable bodies and a connection protection device; the cable body, from the outside to the inside, comprises an outer sheath, an armor layer, an oxygen barrier layer, a shielding layer, and a wrapping layer; the wrapping layer contains a first skeleton, three cable cores, and three second skeletons; the three second skeletons surround the first skeleton; the first skeleton abuts against all three cable cores; each second skeleton abuts against two cable cores; the cable cores, from the outside to the inside, comprise a flame-retardant layer, an insulation layer, and a conductor; the connection protection device comprises two end shaping units, two heat-shrink tubings, three metal connecting tubes, three insulating covering tubes, three winding tapes, three flame-retardant covering tubes, a support portion located between the three flame-retardant covering tubes, and a component wrapping the three flame-retardant covering tubes. The cable includes an outer sheath covering an end-shaping unit and an inner protective tube; each heat-shrinkable tube covers an end-shaping unit and an outer sheath covering the cable body; each winding tape wraps around the outside of an insulating sheath covering tube; both ends of each metal connecting tube are inserted by conductors of two cable cores; each insulating sheath covering tube is inserted by the insulation layer of two cable cores; each flame-retardant sheath covering tube is inserted by the flame-retardant layer of two cable cores; the end-shaping unit includes a cylindrical sheath covering tube and an end plate connected to the sheath covering tube, with three through holes for the cable cores to pass through at the end plate; the support portion has three abutting arc surfaces that abut against the flame-retardant sheath covering tube; the wrapping portion has three receiving spaces for accommodating the flame-retardant sheath covering tube; the inner protective tube includes two semi-circular cylindrical tubes, which are fixedly connected by bolts and nuts.

[0006] Furthermore, each flame-retardant coated tube contains a winding tape, each winding tape contains an insulating coated tube, and each insulating coated tube contains a metal connecting tube.

[0007] Furthermore, each of the three perforations of the end plate has a second rubber ring.

[0008] Thus, the second rubber ring can abut against the flame-retardant layer of the cable core, achieving a better fit between the cable core and the perforation.

[0009] Furthermore, the end plate has an annular stepped portion, and the stepped portion has a first rubber ring; both ends of the semi-circular cylindrical tube have semi-circular abutment plates that can abut against the first rubber ring.

[0010] This allows for better coordination between the inner protective tube and the end shaping unit.

[0011] Furthermore, the semi-circular annular cylindrical tube has multiple countersunk holes on both sides.

[0012] Furthermore, the countersunk hole facilitates the installation of bolts and nuts to securely connect the two semi-cylindrical tubes.

[0013] Furthermore, the semi-circular cylindrical tube has two semi-circular annular grooves and two strip grooves connecting the two semi-circular annular grooves. A sealing gasket is installed at the semi-circular cylindrical tube, and the sealing gasket includes two semi-circular annular gaskets and two strip gaskets connecting the two semi-circular annular gaskets.

[0014] This achieves a sealed connection between the two semi-cylindrical tubes.

[0015] Furthermore, the insulating sheathing tube, the flame-retardant sheathing tube, and the wrapping part all have strip-shaped gaps that allow for unfolding; both sides of the strip-shaped gaps in the flame-retardant sheathing tube have chamfers; the supporting part has a first inner cavity, and the three abutting arc surfaces of the supporting part each have multiple extrusion holes communicating with the first inner cavity; the supporting part also has multiple first insertion holes communicating with the first inner cavity; the wrapping part has a second inner cavity, and the wrapping part has multiple first insertion tubes that can be inserted into the first insertion holes and communicate with the second inner cavity; the wrapping part also has a second insertion hole communicating with the second inner cavity; the two semi-circular annular cylindrical tubes are respectively the first semi-circular annular cylindrical tube and the second semi-circular annular cylindrical tube. The annular cylindrical tube has a third inner cavity, a first arc-shaped channel communicating with the third inner cavity, and multiple second inserts communicating with the third inner cavity and capable of being inserted into a second insertion hole. The second semi-circular annular cylindrical tube has a second arc-shaped channel and an injection hole communicating with the second arc-shaped channel. The second semi-circular annular cylindrical tube also has two arc-shaped inserts, which can be inserted into the two ends of the first arc-shaped channel respectively. The end shaping unit has an exhaust hole. The strip gap, the first insert, the second insert, the first inner cavity, the second inner cavity, the third inner cavity, the first arc-shaped channel, and the second arc-shaped channel of the flame-retardant coated tube are filled with epoxy resin.

[0016] Furthermore, the exhaust port is an L-shaped port.

[0017] Therefore, the vent hole can be used to expel gas during glue injection.

[0018] Furthermore, it also includes an outer protective tube, two first end sealing units, and two second end sealing units; the outer protective tube has internal threads at both ends, the first end sealing unit includes a translational rubber ring, a translational annular plate fixedly connected to the translational rubber ring, a rotating annular plate connected to the translational annular plate and capable of rotating relative to the translational annular plate, an annular rotating block connected to the rotating annular plate through multiple connecting rods, and a rotating rubber ring fixed at the annular rotating block, the annular rotating block having a first external thread, the translational rubber ring having a first venting groove, and the rotating rubber ring having a second venting groove, both the translational rubber ring and the rotating rubber ring being able to abut against the heat shrink tubing; the second end sealing unit includes an inner annular block, an outer annular block, an annular connecting block connecting the inner annular block and the outer annular block, and an end rubber ring fixed to the inner annular block and capable of abutting against the outer sheath of the cable body, the inner annular block having a second external thread.

[0019] Furthermore, the translational annular plate has an annular groove, and the rotating annular plate has an annular slide rail.

[0020] Furthermore, both the first external thread and the second external thread can mate with the internal thread.

[0021] Furthermore, epoxy resin is filled between the two first end sealing units inside the outer protective tube; water-blocking particles are filled between the first end sealing unit and the second end sealing unit inside the outer protective tube.

[0022] Furthermore, the water-blocking particles are water-absorbing resins.

[0023] Furthermore, the insulation layer is a polyethylene insulation layer; the flame retardant layer is a low-smoke halogen-free flame retardant layer; the wrapping layer is a flame retardant tape wrapping layer; the shielding layer is a copper wire braided shielding layer; the armor layer is a steel wire armor layer; and the outer sheath is a polyvinyl chloride outer sheath.

[0024] Furthermore, the annular rotating block has two blind holes.

[0025] Thus, the rotation of the annular rotating block can be achieved by using tools through the blind hole.

[0026] Furthermore, both the inner and outer protective tubes are made of engineering plastics, and the outer protective tube is internally covered with a stainless steel tube.

[0027] Beneficial effects:

[0028] 1) The power cable of this application has multiple sheaths that can effectively achieve insulation and flame retardancy, and the support and wrapping parts achieve better roundness and support for the flame retardant sheaths.

[0029] 2) The power cable of this application can fill the gap in the inner protective tube by injecting epoxy resin, so that the cable connection position can achieve better insulation effect after the epoxy resin is cured, and there are no gaps inside.

[0030] 3) The power cable of this application achieves better protection of the connection position by setting a double-layer protective tube with an inner protective tube and an outer protective tube, and the epoxy resin between the inner and outer protective tubes achieves better sealing protection, and the water-blocking particles between the first and second end sealing units achieve better water blocking. Attached Figure Description

[0031] Figure 1 A schematic diagram showing the connection of the two cable bodies;

[0032] Figure 2 A schematic diagram showing the installation of the shaping unit and heat shrink tubing;

[0033] Figure 3 Schematic diagram for installing metal connecting pipes;

[0034] Figure 4 Schematic diagram for installing insulating sheathing tubes and winding tape;

[0035] Figure 5 Schematic diagram of the installation support and three flame-retardant coated pipes;

[0036] Figure 6 This is a schematic diagram of the package installation section;

[0037] Figure 7 This is a schematic diagram for installing the inner protective tube;

[0038] Figure 8 A schematic diagram showing the movement of the outer protective tube to the inner protective tube;

[0039] Figure 9 A schematic diagram for installing the second end sealing unit;

[0040] Figure 10 This is a schematic diagram showing the separation of cable components;

[0041] Figure 11 This is a magnified view of region A;

[0042] Figure 12 This is a magnified view of region B.

[0043] Figure 13 This is a magnified view of region C;

[0044] Figure 14 This is a magnified view of region D;

[0045] Figure 15 Another perspective diagram showing the separation of cable components;

[0046] Figure 16 This is a magnified view of region E.

[0047] Figure 17 This is a magnified view of region F;

[0048] Figure 18 This is a schematic diagram of the cable cross-section;

[0049] Figure 19 This is a magnified view of region G;

[0050] Figure 20 This is a magnified view of region H;

[0051] Figure 21 This is a schematic diagram of a cross-section of the cable from another direction;

[0052] Figure 22 This is a magnified view of region I;

[0053] Figure 23 This is a magnified view of region J.

[0054] Explanation of reference numerals in the attached drawings: Outer sheath 1.1; Armor layer 1.2; Oxygen barrier layer 1.3; Shielding layer 1.4; Wrapping layer 1.5; First skeleton 2; Second skeleton 3; Cable core 4; Flame retardant layer 4.1; Insulation layer 4.2; Conductor 4.3; End shaping unit 5; Shaping tube 5.1; End circular plate 5.2; Perforation 5.2.1; First rubber ring 5.3; Second rubber ring 5.4; Vent hole 5.5; Heat shrink tubing 6; Metal connecting tube 7; Insulating covering tube 8; Winding tape 8.1; Flame retardant covering tube 9; Support part 10; Abutting arc surface 10.1; First inner cavity 10.2; Extrusion hole 10.3; First insertion hole 10.4; Wrapping part 11; Second inner cavity 11.1; First insertion tube 11.2; Second insertion hole 11.3; Inner protective tube 12; Semi-circular annular cylindrical tube 12.1; First 12.1.1 Half-circular cylindrical tube; 12.1.2 Second half-circular cylindrical tube; 12.1.3 Third inner cavity; 12.1.4 First arc-shaped channel; 12.1.5 Second insertion tube; 12.1.6 Second arc-shaped channel; 12.1.7 Injection hole; 12.2 Abutment plate; 12.3 Countersunk hole; 12.4 Semi-circular annular gasket; 12.5 Strip gasket; 12.6 Arc-shaped insertion tube; 13 Outer protective tube; 13.1 Internal thread; 14.1 Translation rubber ring; 14.2 Translation annular plate; 14.3 Rotating annular plate; 14.4 Connecting rod; 14.5 Annular rotating block; 14.6 Rotating rubber ring; 14.7 First vent groove; 14.8 Second vent groove; 15.1 Inner annular block; 15.2 Outer annular block; 15.3 Annular connecting block; 15.4 End rubber ring. Detailed Implementation

[0055] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0056] This invention provides a high-efficiency protective polyethylene special power cable as shown in the figure, comprising two cable bodies and a connection protection device. The cable bodies, from the outside to the inside, include an outer sheath 1.1, an armor layer 1.2, an oxygen barrier layer 1.3, a shielding layer 1.4, and a wrapping layer 1.5. The wrapping layer 1.5 contains a first skeleton 2, three cable cores 4, and three second skeletons 3. The three second skeletons 3 surround the first skeleton 2, and the first skeleton 2 abuts against all three cable cores 4. Each second skeleton 3 abuts against two cable cores 4. The cable cores 4, from the outside to the inside, sequentially include a flame-retardant layer 4.1, an insulation layer 4.2, and a conductor 4.3. The connection protection device includes two end shaping units 5, two heat-shrink tubing 6, three metal connecting tubes 7, three insulating covering tubes 8, three winding tapes 8.1, three flame-retardant covering tubes 9, a support portion 10 located between the three flame-retardant covering tubes 9, a wrapping portion 11 wrapping the three flame-retardant covering tubes 9, and an inner protective layer. The cable includes a protective tube 12; each heat shrink tube 6 covers an end shaping unit 5 and an outer sheath 1.1 of the cable body; each winding tape 8.1 is wrapped around the outside of an insulating sheath tube 8; the two ends of each metal connecting tube 7 are inserted by the conductors 4.3 of the two cable cores 4; each insulating sheath tube 8 is inserted by the insulation layer 4.2 of the two cable cores 4; and each flame-retardant sheath tube 9 is inserted by the flame-retardant layer 4.1 of the two cable cores 4. The end shaping unit 5 includes a cylindrical shaping tube 5.1 and an end plate 5.2 connected to the shaping tube 5.1. The end plate 5.2 has three through holes 5.2.1 through which the cable cores 4 pass. The support part 10 has three abutting arc surfaces 10.1 that abut against the flame-retardant sheath tube 9. The wrapping part 11 has three receiving spaces for accommodating the flame-retardant sheath tube 9. The inner protective tube 12 includes two semi-circular cylindrical tubes 12.1, which are fixedly connected by bolts and nuts. Each flame-retardant coated tube 9 contains a winding tape 8.1, each winding tape 8.1 contains an insulating coated tube 8, and each insulating coated tube 8 contains a metal connecting tube 7.

[0057] The end circular plate 5.2 has an annular stepped portion, and a first rubber ring 5.3 is located at the stepped portion; each of the three through holes in the end circular plate 5.2 has a second rubber ring 5.4; both ends of the semi-circular cylindrical tube 12.1 have semi-circular abutment plates 12.2 that can abut against the first rubber rings 5.3. Both sides of the semi-circular cylindrical tube 12.1 have multiple countersunk holes 12.3; the semi-circular cylindrical tube 12.1 has two semi-circular grooves and two strip grooves connecting the two semi-circular grooves; a sealing gasket is installed at the semi-circular cylindrical tube 12.1, and the sealing gasket includes two semi-circular gaskets 12.4 and two strip gaskets 12.5 connecting the two semi-circular gaskets 12.4. The insulating sheathing tube 8, the flame-retardant sheathing tube 9, and the wrapping part 11 all have strip-shaped gaps that allow them to unfold; both sides of the strip-shaped gaps of the flame-retardant sheathing tube 9 have chamfers; the support part 10 has a first inner cavity 10.2, and the three abutting arc surfaces 10.1 of the support part 10 each have multiple extrusion holes 10.3 communicating with the first inner cavity 10.2; the support part 10 also has multiple first insertion holes 10.4 communicating with the first inner cavity 10.2; the wrapping part 11 has a second inner cavity 11.1, and the wrapping part 11 has multiple first insertion tubes 11.2 that can be inserted into the first insertion holes and communicate with the second inner cavity 11.1; the wrapping part 11 also has second insertion holes 11.3 communicating with the second inner cavity 11.1; the two semi-circular cylindrical tubes 12.1 are respectively the first semi-circular cylindrical tube 12.1.1 and the second semi-circular cylindrical tube 12.1.2, and the first semi-circular cylindrical tube 12.1.1 has a third inner cavity 12. 1.3, a first arc-shaped channel 12.1.4 communicating with the third inner cavity 12.1.3, and multiple second insertion tubes 12.1.5 communicating with the third inner cavity 12.1.3 and capable of being inserted into the second insertion hole 11.3; the second semi-circular annular cylindrical tube 12.1.2 has a second arc-shaped channel 12.1.6 and an injection hole 12.1.7 communicating with the second arc-shaped channel 12.1.6; the second semi-circular annular cylindrical tube 12.1.2 also has two arc-shaped channels. The two arc-shaped cannulas 12.6 can be inserted into the two ends of the first arc-shaped channel 12.1.4 respectively; the end shaping unit 5 has an exhaust hole 5.5; the strip gap of the flame-retardant coated tube 9, the first cannulas 11.2, the second cannulas 12.1.5, the first inner cavity 10.2, the second inner cavity 11.1, the third inner cavity 12.1.3, the first arc-shaped channel 12.1.4, and the second arc-shaped channel 12.1.6 are filled with epoxy resin. The exhaust hole 5.5 is an L-shaped hole.

[0058] The cable also includes an outer protective tube 13, two first end sealing units, and two second end sealing units. The outer protective tube 13 has internal threads 13.1 at both ends. Each first end sealing unit includes a translational rubber ring 14.1, a translational annular plate 14.2 fixedly connected to the translational rubber ring 14.1, a rotating annular plate 14.3 connected to and rotatable relative to the translational annular plate 14.2, an annular rotating block 14.5 connected to the rotating annular plate 14.3 via multiple connecting rods 14.4, and a rotating rubber ring 14.6 fixed to the annular rotating block 14.5. The moving block 14.5 has a first external thread, the translational rubber ring 14.1 has a first venting groove 14.7, and the rotating rubber ring 14.6 has a second venting groove 14.8. Both the translational rubber ring 14.1 and the rotating rubber ring 14.6 can abut against the heat shrink tubing 6. The second end sealing unit includes an inner annular block 15.1, an outer annular block 15.2, an annular connecting block 15.3 connecting the inner annular block 15.1 and the outer annular block 15.2, and an end rubber ring 15.4 fixed to the inner annular block 15.1 and able to abut against the outer sheath 1.1 of the cable body. The inner annular block 15.1 has a second external thread. Both the first external thread and the second external thread can mate with the inner thread 13.1. Epoxy resin is filled between the two first end sealing units inside the outer protective tube 13; water-blocking particles are filled between the first end sealing units and the second end sealing units inside the outer protective tube 13. The water-blocking particles are water-absorbing resin. The insulation layer 4.2 is a polyethylene insulation layer; the flame-retardant layer 4.1 is a low-smoke halogen-free flame-retardant layer; the wrapping layer 1.5 is a flame-retardant tape wrapping layer; the shielding layer 1.4 is a copper wire braided shielding layer; the armor layer 1.2 is a steel wire armor layer; and the outer sheath 1.1 is a polyvinyl chloride outer sheath. The annular rotating block 14.5 has two blind holes 14.5.1. Thus, the annular rotating block 14.5 can be rotated using tools through the blind holes. Both the inner protective tube 12 and the outer protective tube 13 are made of engineering plastic, and the outer protective tube 13 is internally covered with a stainless steel tube.

[0059] Working principle: The cable processing method of this application includes the following steps:

[0060] 1) such as Figure 1 As shown, the insulation, flame-retardant layer, and wrapping layer at the ends of the two cable bodies are peeled off and cleaned. At this point, the outer protective tube, two first end sealing units, and two second end sealing units need to be inserted into one of the cable bodies and set aside for now.

[0061] 2) such as Figure 2 As shown, two end shaping units are installed to shape the ends of the cable body and install heat shrink tubing.

[0062] 3) such as Figure 3As shown, a metal connecting tube is installed, the conductors of the two cable bodies are inserted into the metal connecting tube, and the metal connecting tube is pressed tightly, thereby connecting the conductors of the two cable bodies through the metal connecting tube.

[0063] 4) such as Figure 4 As shown, the insulating sheath tube and winding tape are installed. The insulating sheath tube has strip-shaped gaps, which makes it easier to install.

[0064] 5) such as Figure 5 As shown, the mounting support and three flame-retardant coated tubes are installed. The flame-retardant coated tubes have strip-shaped gaps, which makes them easier to install.

[0065] 6) For example Figure 6 As shown, the wrapping section is installed. The wrapping section has strip-shaped gaps, which makes it easier to install.

[0066] 7) For example Figure 7 As shown, the inner protective tube is installed and locked with bolts and nuts. Epoxy resin is injected through the injection hole, filling the second arc-shaped channel, the first arc-shaped channel, the third inner cavity, the second insertion tube, the second inner cavity, the first insertion tube, and the first inner cavity. It is also extruded from the extrusion hole to fill the strip-shaped gaps in the flame-retardant coating tube. Thus, the epoxy resin fills the gaps within the connecting protective device and also seals the strip-shaped gaps in the flame-retardant coating tube. Furthermore, the vent hole can be used for venting during the injection process.

[0067] 8) For example Figure 8 As shown, the outer protective tube is moved to the position of the inner protective tube, and epoxy resin is filled into the outer protective tube. Two first end sealing units are inserted from both ends of the outer protective tube, and the annular rotating block is rotated to squeeze the epoxy resin, thereby reducing the space between the two first end sealing units but filling it with epoxy resin. During this process, the air between the two first end sealing units can be discharged from the first exhaust groove and the second exhaust groove.

[0068] 9) For example Figure 9 As shown, water-blocking particles can be placed, followed by the installation of two second end-sealing units.

[0069] After the two cable bodies of this application are protected by the connection protection device, it can be seen that after the inner protective tube is installed, the gaps inside the inner protective tube are filled with epoxy resin by injecting epoxy resin. After the epoxy resin cures, the internal insulating covering tube, wrapping tape, flame-retardant covering tube, support part and wrapping part form a whole, achieving better protection for the cable connection position. Then, the outer protective tube is installed, and epoxy resin is filled between the inner and outer protective tubes (the two first end sealing units are close to each other and squeezed, so that the epoxy resin can better fill the space between the inner and outer protective tubes). Water-blocking particles are filled between the first and second end sealing units of the outer protective tube, thereby achieving better water-blocking effect. The first and second end sealing units achieve double sealing of the ends of the outer protective tube.

[0070] Although the present invention has been illustrated and described with reference to preferred embodiments, those skilled in the art should understand that various changes and modifications can be made to the present invention without departing from the scope defined by the claims.

Claims

1. A high-efficiency protective polyethylene special power cable, characterized in that, The cable includes two cable bodies and a connection protection device. The cable body, from the outside in, comprises an outer sheath, an armor layer, an oxygen barrier layer, a shielding layer, and a wrapping layer. The wrapping layer contains a first skeleton, three cable cores, and three second skeletons. The three second skeletons surround the first skeleton, and the first skeleton abuts against all three cable cores. Each second skeleton abuts against two cable cores. The cable cores, from the outside in, comprise a flame-retardant layer, an insulation layer, and a conductor. The connection protection device includes two end-shaping units, two heat-shrink tubings, three metal connecting tubes, three insulating covering tubes, three winding tapes, three flame-retardant covering tubes, a support portion located between the three flame-retardant covering tubes, a wrapping portion enclosing the three flame-retardant covering tubes, and an inner protective tube. Each heat-shrink tubing... The tube covers an end-shaping unit and an outer sheath of the cable body; each winding tape wraps around the outside of an insulating sheath tube, each end of each metal connecting tube is inserted by the conductors of two cable cores, each insulating sheath tube is inserted by the insulation layer of two cable cores, and each flame-retardant sheath tube is inserted by the flame-retardant layer of two cable cores; the end-shaping unit includes a cylindrical shaping tube and an end plate connected to the shaping tube, the end plate having three through holes through which the cable cores pass; the support has three abutting arc surfaces that abut the flame-retardant sheath tube, and the wrapping part has three receiving spaces for accommodating the flame-retardant sheath tube; the inner protective tube includes two semi-circular cylindrical tubes, which are fixedly connected by bolts and nuts.

2. The high-efficiency protective polyethylene special power cable according to claim 1, characterized in that, The end plate has an annular stepped portion, and the stepped portion has a first rubber ring; each of the three through holes of the end plate has a second rubber ring; both ends of the semi-circular cylindrical tube have semi-circular abutment plates that can abut against the first rubber ring.

3. The high-efficiency protective polyethylene special power cable according to claim 1, characterized in that, The semi-circular annular cylindrical tube has multiple countersunk holes on both sides; the semi-circular annular cylindrical tube has two semi-circular annular grooves and two strip grooves connecting the two semi-circular annular grooves; a sealing gasket is installed at the semi-circular annular cylindrical tube, and the sealing gasket includes two semi-circular annular gaskets and two strip gaskets connecting the two semi-circular annular gaskets.

4. The high-efficiency protective polyethylene special power cable according to claim 1, characterized in that, The insulating sheath, flame-retardant sheath, and wrapping portion all have strip-shaped gaps that allow for unfolding; both sides of the strip-shaped gaps in the flame-retardant sheath have chamfers; the supporting portion has a first inner cavity, and each of the three abutting arc surfaces of the supporting portion has multiple extrusion holes communicating with the first inner cavity; the supporting portion also has multiple first insertion holes communicating with the first inner cavity; the wrapping portion has a second inner cavity, and the wrapping portion has multiple first insertion tubes that can be inserted into the first insertion holes and communicate with the second inner cavity; the wrapping portion also has second insertion holes communicating with the second inner cavity; the two semi-circular annular cylindrical tubes are respectively the first semi-circular annular cylindrical tube and the second semi-circular annular cylindrical tube. The tube has a first semi-circular cylindrical tube with a third inner cavity, a first arc-shaped channel communicating with the third inner cavity, and multiple second inserts communicating with the third inner cavity and capable of being inserted into a second insertion hole. The second semi-circular cylindrical tube has a second arc-shaped channel and an injection hole communicating with the second arc-shaped channel. The second semi-circular cylindrical tube also has two arc-shaped inserts, which can be inserted into the two ends of the first arc-shaped channel respectively. The end shaping unit has an exhaust hole. The strip gap, first insert, second insert, first inner cavity, second inner cavity, third inner cavity, first arc-shaped channel, and second arc-shaped channel of the flame-retardant coated tube are filled with epoxy resin.

5. The high-efficiency protective polyethylene special power cable according to claim 1, characterized in that, It also includes an outer protective tube, two first end sealing units, and two second end sealing units; the outer protective tube has internal threads at both ends; the first end sealing unit includes a translational rubber ring, a translational annular plate fixedly connected to the translational rubber ring, a rotating annular plate connected to the translational annular plate and capable of rotating relative to the translational annular plate, an annular rotating block connected to the rotating annular plate via multiple connecting rods, and a rotating rubber ring fixed at the annular rotating block; the annular rotating block has a first external thread; the translational rubber ring has a first venting groove; the rotating rubber ring has a second venting groove; both the translational rubber ring and the rotating rubber ring can abut against the heat shrink tubing; the second end sealing unit includes an inner annular block, an outer annular block, an annular connecting block connecting the inner annular block and the outer annular block, and an end rubber ring fixed to the inner annular block and capable of abutting against the outer sheath of the cable body; the inner annular block has a second external thread.

6. The high-efficiency protective polyethylene special power cable according to claim 1, characterized in that, The space between the two first end sealing units inside the outer protective tube is filled with epoxy resin adhesive; the space between the first end sealing unit and the second end sealing unit inside the outer protective tube is filled with water-blocking particles.

7. The high-efficiency protective polyethylene special power cable according to claim 1, characterized in that, The insulation layer is a polyethylene insulation layer; the flame retardant layer is a low-smoke halogen-free flame retardant layer; the wrapping layer is a flame retardant tape wrapping layer; the shielding layer is a copper wire braided shielding layer; the armor layer is a steel wire armor layer; and the outer sheath is a polyvinyl chloride outer sheath.

8. The high-efficiency protective polyethylene special power cable according to claim 5, characterized in that, The annular rotating block has two blind holes; the translational annular plate has an annular groove; and the rotating annular plate has an annular slide rail.

9. The high-efficiency protective polyethylene special power cable according to claim 5, characterized in that, Both the inner and outer protective tubes are made of engineering plastics, and the outer protective tube is internally covered with a stainless steel tube.

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