Production equipment and production method for 110kv high-voltage polypropylene insulated power cable

Abstract

The invention relates to the field of cable production equipment, in particular to 110 kv high-pressure polypropylene insulation power cable production equipment and a production method.The 110 kv high-pressure polypropylene insulation power cable production equipment comprises sliding plates arranged on the conical inner wall of the discharging end of a mold core in a sliding mode, rolling wheels a are rotationally arranged on the sliding plates, and a rotary extrusion mechanism drives the sliding plates to move so that a cable can be clamped through the rolling wheels a; and the supporting frames are rotationally arranged on the conical inner wall of the discharging end of the mold core, rolling wheels b are rotationally arranged at the ends of the supporting frames, and the movable extrusion mechanism drives the multiple supporting frames to rotate synchronously so as to clamp or loosen the cable through the multiple rolling wheels b. According to the invention, cables with different diameters are extruded and positioned through the plurality of rollers a and the rollers b, the device can adapt to the cables with different sizes, the application range is wider, and the limiting effect is better by performing annular limiting on two positions of the cables. In addition, dust on the surface of the cable is cleaned and adsorbed before the cable is coated, so that the coating quality of the insulating layer is improved.

Description

Technical Field

[0001] The present invention relates to the field of cable production equipment, and particularly to a production equipment and production method for 110 kV high-voltage polypropylene-insulated power cables. Background Art

[0002] A 110 kV high-voltage polypropylene-insulated power cable is a power cable using polypropylene (PP) as an insulating material for transmitting high-voltage electricity. Compared with traditional cross-linked polyethylene-insulated cables, this cable has the advantages of being green and environmentally friendly, having good thermoplasticity, and good heat resistance. During the production process of the cable, an extruder is required to coat an insulating layer around the conductor.

[0003] Chinese Patent with publication number CN114843045B discloses a composite cable and its production equipment, including an extrusion pipe, a limiting component, a connecting component, and a cable wire. When extruding the composite cable, the wire bundle passes through the extrusion pipe and the sleeve, and by controlling the connecting component, the movement of the limiting component is driven. The limiting component restricts the wire bundle, reducing the shaking of the wire bundle, so that the wire bundle is more stable when passing through the extrusion pipe, avoiding the situation that when passing through the extrusion pipe, due to continuous shaking, the coating layer is uneven during extrusion molding, making the production quality of the cable more stable and reducing the defective rate.

[0004] However, the above-mentioned disclosed solution has the following deficiencies: The wire bundle is limited by the cooperation of a pressure rod and a spring structure. Due to the elasticity of the spring and the fact that there is no limiting structure for a certain distance before and after the extruder for the wire bundle, when the wire bundle vibrates, it will drive multiple springs to move out of sync, still unable to well limit the irregular shaking of the wire bundle. Moreover, the position where the pressure rod limits is still a certain distance away from the coating outlet, further reducing the effect of positioning and anti-shaking of the wire bundle. Summary of the Invention

[0005] The object of the present invention is to address the problems in the background art that the adjustable limiting structure of the spring structure cannot well limit the shaking of the wire bundle, and due to structural limitations, the positioning position is at a relatively long distance from the coating outlet, and to propose a production equipment and production method for 110 kV high-voltage polypropylene-insulated power cables.

[0006] On the one hand, the present invention proposes a production equipment for 110 kV high-voltage polypropylene-insulated power cables, including a screw feeding device, a head, and a cable. The screw feeding device transports the molten insulating raw material to the head, and the head coats an insulating layer on the passing cable. The head includes a head shell, a die sleeve, a die core, and a die orifice arranged on the inner wall of the head shell from outside to inside; it further includes:

[0007] The skateboard is slidably arranged on the conical inner wall at the discharging end of the die core. A roller a is rotatably arranged on the skateboard. A plurality of skateboards are arranged along the circumferential direction. A rotary extrusion mechanism is arranged on the inner wall of the die core. The rotary extrusion mechanism drives the plurality of skateboards to move so as to clamp the cable by means of the plurality of rollers a.

[0008] And a support frame is rotatably arranged on the conical inner wall at the discharging end of the die core in plurality. A roller b is rotatably arranged at the end of the support frame. The roller b is located between the roller a and the discharging port of the die core. A moving extrusion mechanism is arranged on the inner wall of the die core. The moving extrusion mechanism drives the plurality of support frames to rotate synchronously so as to clamp or loosen the cable by means of the plurality of rollers b.

[0009] Preferably, a feed pipe connected to the output end of the screw feeding device is arranged on the outer shell of the machine head; a flow channel communicated with the feed pipe is arranged on the outer wall of the die sleeve. The flow channel forms an opening at the discharging end of the die sleeve.

[0010] Preferably, a die adjustment mechanism is further included to adjust the position of the die along the axial direction of the die core.

[0011] Preferably, threads are arranged on the inner wall at the feeding end of the die core; the rotary extrusion mechanism includes a rotary ring matched with the threads, a support ring rotatably arranged on the rotary ring, and a connecting rod with two ends respectively rotatably connected to the support ring and the skateboard.

[0012] Preferably, a plurality of guide rods are arranged on the end face of the support ring facing away from the rotary ring. A plurality of guide plates are arranged on the inner wall of the die core. Guide holes for the guide rods to pass through are arranged on the guide plates.

[0013] Preferably, a plurality of fixing blocks are arranged on the conical inner wall of the die core. A support rod is rotatably arranged between two fixing blocks. The support frame is arranged on the support rod.

[0014] Preferably, the moving extrusion mechanism includes a pull rope a, a pull rope b, a moving ring a and a moving ring b; the moving ring a and the moving ring b are both slidably arranged on the inner wall of the die core along the axial direction of the cable. The moving ring a is located between the moving ring b and the rotary ring; one end of the pull rope a is connected to the moving ring a, and the other end is connected and wound on the support rod. One end of the pull rope b is connected to the moving ring b, and the other end is connected and wound on the support rod. The winding directions of the pull rope a and the pull rope b are opposite and are respectively located on both sides of the support frame.

[0015] Preferably, a plurality of bristles are arranged on the support frame. Avoidance grooves are arranged on the support frame. A placement hose passes through the plurality of avoidance grooves. A plurality of dust suction holes are arranged on the hose. A connecting pipe is arranged on the hose. The connecting pipe is communicated with an external dust suction device.

[0016] On the other hand, the present invention provides a production method for a 110kv high-voltage polypropylene insulated power cable production device, including the following steps:

[0017] S1. The cable is pulled through the machine head. According to the cable diameter, while rotating the rotating ring to make it rotate, move it back and forth. Then drive the slide plate to move through the support ring and the connecting rod. The slide plate moves along the conical surface of the die core, so that multiple rollers a squeeze the cable from all around to complete the cable positioning.

[0018] S2. According to the cable diameter, adjust the axial positions of the moving ring a and the moving ring b. By the tension of the pull rope a or the pull rope b, squeeze the roller b against the cable to further position the cable. At the same time, the brush cleans the cable surface, and the dust cleaned is adsorbed by the hose to ensure the quality of the subsequent insulation layer coating.

[0019] S3. The screw feeding device transports the molten insulating raw material into the machine head to complete the coating of the insulation layer.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] 1. According to the adjustment of the rotary extrusion mechanism and the moving extrusion mechanism, use multiple rollers a and rollers b to perform extrusion positioning on cables with different diameters. On the one hand, it can adapt to cables of different sizes and has a wider application range. On the other hand, through the annular positioning of the cable at two positions, the positioning effect is better.

[0022] 2. By cleaning and adsorbing the surface dust before coating the cable, it can avoid defects such as bubbles and bulges caused by dust when coating the insulation layer, which helps to improve the quality of the insulation layer coating. Description of the Drawings

[0023] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0024] Figure 2 is a schematic structural diagram of the machine head;

[0025] Figure 3 and Figure 4 are both schematic diagrams of the interior of the machine head housing;

[0026] Figure 5 is a schematic structural diagram of the die core;

[0027] Figure 6 is a schematic diagram of the internal structure of the die core;

[0028] Figure 7 and Figure 8 are both Figure 6 partial schematic structural diagrams of;

[0029] Figure 9 is Figure 6 the enlarged schematic diagram at A in;

[0030] Reference numerals: 1, screw feeding device; 2, machine head; 3, cable; 4, insulating layer; 5, connecting frame; 6, machine head housing; 7, feed pipe; 8, die sleeve; 9, flow channel; 10, die core; 11, slide plate; 12, slider; 13, roller a; 14, connecting rod; 15, sphere; 16, sphere mounting seat; 17, support ring; 18, guide rod; 19, guide plate; 20, rotating ring; 21, rotating lever; 22, fixed block; 23, support rod; 24, pull rope a; 25, pull rope b; 26, support frame; 27, roller b; 28, brush; 29, avoidance groove; 30, hose; 31, connecting pipe; 32, moving ring a; 33, moving ring b; 34, chute; 35, screw a; 36, screw b; 37, fixing plate; 38, nut; 39, die; 40, adjusting bolt; 41, dust flow hole; 42, dust suction pipe. Detailed implementation mode

[0031] Example 1, as Figures 1-8 shown, a 110kv high-voltage polypropylene insulated power cable production equipment proposed by the present invention includes a screw feeding device 1, a machine head 2 and a cable 3. The screw feeding device 1 transports the molten insulating raw material to the machine head 2, and the machine head 2 coats the insulating layer 4 on the passing cable 3. The machine head 2 includes a machine head housing 6, a die sleeve 8, a die core 10 arranged from outside to inside in sequence, and a die 39 arranged on the inner wall of the machine head housing 6. The insulating material is extruded from the gap between the inner wall of the die 39 and the outer wall of the discharging end of the die core 10 and coated on the cable 3; it further includes:

[0032] A slide plate 11, which is slidably arranged on the conical inner wall of the discharging end of the die core 10. A roller a 13 is rotatably arranged on the slide plate 11. A plurality of slide plates 11 are arranged along the circumferential direction. A rotary extrusion mechanism is arranged on the inner wall of the die core 10. The rotary extrusion mechanism drives the plurality of slide plates 11 to move so as to clamp the cable 3 through the plurality of rollers a 13. In an optional embodiment, a slider 12 is arranged on the slide plate 11, and a slide rail is arranged on the conical inner wall of the die core 10. The slider 12 is slidably matched on the slide rail;

[0033] And a support frame 26, which is rotatably arranged on the conical inner wall of the discharging end of the die core 10. A roller b 27 is rotatably arranged at the end of the support frame 26. The roller b 27 is in rolling contact with the cable 3. The roller b 27 is located between the roller a 13 and the discharging port of the die core 10. A plurality of support frames 26 are arranged. A moving extrusion mechanism is arranged on the inner wall of the die core 10. The moving extrusion mechanism drives the plurality of support frames 26 to rotate synchronously so as to clamp or loosen the cable 3 through the plurality of rollers b 27.

[0034] Further, a plurality of connecting frames 5 are provided on the head shell 6. The connecting frames 5 are connected to the screw feeding device 1. An inlet pipe 7 is provided on the head shell 6, and the inlet pipe 7 is connected to the output end of the screw feeding device 1. A flow channel 9 is provided on the outer wall of the die sleeve 8, and the flow channel 9 is communicated with the inlet pipe 7. The flow channel 9 forms an opening at the discharging end of the die sleeve 8. The molten insulating layer raw material enters the gap between the die head 39 and the die core 10 through the inlet pipe 7 and the flow channel 9.

[0035] Further, it further includes a die head adjusting mechanism, specifically an adjusting bolt 40. The inner side of the die head 39 is a conical surface. An extension plate is provided on the die head 39, and a threaded hole is provided on the extension plate. A through hole opposite to the threaded hole is provided on the head shell 6. The adjusting bolt 40 is fitted through the threaded hole and inserted into the through hole. The end of the adjusting bolt 40 is rotatably connected to the inner wall of the through hole. The extension plate is locked on the head shell 6 through the adjusting bolt 40. By rotating the adjusting bolt 40, the axial position of the die head 39 can be changed, so as to change the size of the gap between the die head 39 and the die core 10, thereby changing the thickness of the insulating layer 4. In an optional embodiment, a smooth rod is provided at the end of the adjusting bolt 40, and the smooth rod and the inner wall of the through hole are rotatably connected through a bearing.

[0036] Embodiment 2, as Figures 6-9 shown, a 110kv high-voltage polypropylene insulated power cable production device proposed by the present invention. Compared with Embodiment 1, the structure of the rotary extrusion mechanism is introduced in detail in this embodiment.

[0037] Threads are provided on the inner wall of the feeding end of the die core 10. The rotary extrusion mechanism includes a rotary ring 20 that mates with the threads, a support ring 17 rotatably provided on the rotary ring 20, and a connecting rod 14 whose two ends are respectively rotatably connected to the support ring 17 and the slide plate 11. In an optional embodiment, spherical seat 16 are provided on both the support ring 17 and the slide plate 11. A sphere 15 is rotatably provided on the spherical seat 16. Both ends of the connecting rod 14 are connected to the sphere 15. A plurality of connecting rods 14 are arranged along the circumferential direction. In addition, in order to facilitate the rotation of the rotary ring 20, a plurality of rotating levers 21 are provided on the end face of the rotary ring 20 facing away from the support ring 17.

[0038] Further, an annular groove is provided on the rotary ring 20, an annular guide rail is provided on the support ring 17, the annular guide rail and the annular groove cooperate with each other. A plurality of guide rods 18 are provided on the end face of the support ring 17 facing away from the rotary ring 20. A plurality of guide plates 19 are provided on the inner wall of the die core 10, and guide holes for the guide rods 18 to pass through are provided on the guide plates 19.

[0039] Embodiment 3, as Figures 6-9 shown, a 110kv high-voltage polypropylene insulated power cable production device proposed by the present invention. Compared with Embodiment 2, the structure of the moving extrusion mechanism is introduced in detail in this embodiment.

[0040] A plurality of fixed blocks 22 are arranged on the conical inner wall of the mold core 10, a support rod 23 is rotatably arranged between two fixed blocks 22, and a support frame 26 is arranged on the support rod 23. The mobile extrusion mechanism includes a pull rope a24, a pull rope b25, a mobile ring a32 and a mobile ring b33; the mobile ring a32 and the mobile ring b33 are both slidably arranged on the inner wall of the mold core 10 along the axial direction of the cable 3, the mobile ring a32 is located between the mobile ring b33 and the rotating ring 20, and the inner diameter of the mobile ring a32 is smaller than the inner diameter of the mobile ring b33. In an optional embodiment, a slide groove 34 is arranged on the outer circumference of the mobile ring a32 and the mobile ring b33, and a plurality of guide rails are arranged on the inner wall of the mold core 10. The slide groove 34 cooperates with the guide rails to achieve sliding. In this embodiment, the number of the slide grooves 34 is three. In addition, in order to adjust and fix the positions of the movable ring a32 and the movable ring b33, the movable ring a32 and the movable ring b33 are respectively provided with screws a35 and screws b36 along the axial direction, and two fixed plates 37 are provided at the end of the core 10. The fixed plate 37 is provided with threaded holes for the screws a35 and screws b36 to pass through. A nut 38 is rotatably provided on the fixed plate 37, and the nut 38 cooperates with the screws a35 and screws b36. The nut 38 is rotatably connected to the fixed plate 37 as follows: an annular groove is provided on the fixed plate 37, and the cross-section of the annular groove is dovetail-shaped. An annular slide rail is provided in the annular groove, and then the annular slide rail and the nut 38 are connected by spot welding. For easy installation, the fixed plate 37 and the annular slide rail are both spliced ​​by multiple sections; one end of the pull rope a24 is connected to the movable ring a32, and the other end It is connected and wound around the support rod 23, one end of the pull rope b25 is connected to the moving ring b33, and the other end is connected and wound around the support rod 23, the winding directions of the pull rope a24 and the pull rope b25 are opposite and are respectively located on both sides of the support frame 26; the moving ring a32 is moved outward to drive the pull rope a24 to move, so that the support frame 26 rotates counterclockwise, and the roller b27 is squeezed on the cable 3, and the moving ring b33 is moved outward to make the support frame 26 rotate clockwise, and the roller b27 is expanded outward to break away from the contact with the cable 3, and can be used to clamp a cable 3 with a larger diameter. It should be noted that when moving the moving ring a32 outward, the pull rope b25 must be loosened by moving the moving ring b33 in the opposite direction. Conversely, when moving the moving ring b33 outward, it is also necessary to move the moving ring a32 in the opposite direction to loosen the pull rope a24.

[0041] Embodiment 4, as Figure 9 As shown, the present invention proposes a 110kv high-voltage polypropylene insulated power cable production equipment. Compared with the third embodiment, this embodiment introduces in detail the cleaning structure of the cable 3 before the insulation layer 4 is coated.

[0042] A plurality of bristles 28 are provided on the support frame 26. The bristles 28 are in contact with the cable 3. Avoidance grooves 29 are provided on the support frame 26. A plurality of placement hoses 30 pass through the avoidance grooves 29. A plurality of dust suction holes are provided on the hose 30. A connecting pipe 31 is provided on the hose 30. The connecting pipe 31 communicates with an external dust suction device. Specifically, opposite dust circulation holes 41 are opened on the mold core 10 and the mold sleeve 8. The dust circulation holes 41 are connected to the connecting pipe 31. A dust suction pipe 42 opposite to the dust circulation holes 41 is provided on the machine head housing 6. The dust suction pipe 42 is connected to an external dust suction device; the dust suction holes are closer to the discharge port of the mold core 10, and can clean the surface of the cable 3 before the starting position of the cable 3 being coated with the insulating layer 4, ensuring the coating quality.

[0043] Embodiment 5. A production method of a 110 kV high-voltage polypropylene insulated power cable proposed by the present invention uses the 110 kV high-voltage polypropylene insulated power cable production equipment of Embodiment 4, and specifically includes the following steps:

[0044] S1. The cable 3 is drawn through the machine head 2. According to the diameter of the cable 3, the rotating ring 20 is rotated and moved back and forth at the same time. Then, the support ring 17 and the connecting rod 14 drive the slide plate 11 to move. The slide plate 11 moves along the conical surface of the mold core 10, so that a plurality of rollers a13 squeeze the cable 3 from all around to complete the limitation of the cable 3.

[0045] S2. According to the diameter of the cable 3, the axial positions of the moving ring a32 and the moving ring b33 are adjusted. Through the tension of the pull rope a24 or the pull rope b25, the roller b27 is squeezed against the cable 3 to further limit the cable 3. At the same time, the bristles 28 clean the surface of the cable 3, and the dust cleaned is adsorbed by the hose 30, ensuring the subsequent insulating layer coating quality.

[0046] S3. The screw feeding device 1 conveys the molten insulating raw material into the machine head 2 to complete the coating of the insulating layer 4.

[0047] In summary, when the present invention is in use, according to the adjustment of the rotary extrusion mechanism and the moving extrusion mechanism, the cables 3 with different diameters are extruded and positioned by a plurality of rollers a13 and rollers b27. On the one hand, it can adapt to cables 3 of different sizes, with a wider range of use. On the other hand, by performing annular limiting at two positions on the cable 3, the limiting effect is better, because it is difficult to limit the transmission of the jitter of the cable 3 itself by single-point limiting in the prior art, while the limitation at two positions can well suppress the transmission of the jitter of the cable 3 itself, enabling the cable 3 at the position where the insulating layer 4 is coated to move stably. Moreover, due to the fact that the roller b27 is close to the coating position and the hard limitation of the rollers a13 and b27, cables 3 of different sizes can be traction-moved very stably. In addition, by cleaning and adsorbing the surface dust of the cable 3 before coating, defects such as bubbles and bulges caused by dust during the coating of the insulating layer 4 can be avoided, which helps to improve the coating quality of the insulating layer 4.

[0048] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those skilled in the art to which the present invention pertains.

Claims

1. A 110kV high-voltage polypropylene insulated power cable production equipment, comprising a screw feeding device (1), a die (2) and a cable (3), wherein the screw feeding device (1) conveys molten insulating raw materials to the die (2), the die (2) covers an insulating layer (4) on the cable (3) passing through, and the die (2) comprises a die housing (6), a die sleeve (8), a die core (10) and a die (39) arranged on the inner wall of the die housing (6) in sequence from outside to inside; characterized in that: Also includes: A slide plate (11) is slidably arranged on the conical inner wall of the discharge end of the mold core (10), a roller a (13) is rotatably arranged on the slide plate (11), a plurality of slide plates (11) are arranged along the circumferential direction, a rotary extrusion mechanism is arranged on the inner wall of the mold core (10), and the rotary extrusion mechanism drives the plurality of slide plates (11) to move so as to clamp the cable (3) through the plurality of rollers a (13); A support frame (26) is rotatably arranged on the conical inner wall of the discharge end of the mold core (10), a roller b (27) is rotatably arranged at the end of the support frame (26), and the roller b (27) is located between the roller a (13) and the discharge port of the mold core (10). A movable extrusion mechanism is arranged on the inner wall of the mold core (10), and the movable extrusion mechanism drives the plurality of support frames (26) to rotate synchronously, thereby clamping or releasing the cable (3) through the plurality of rollers b (27).

2. The 110kv high voltage polypropylene insulated power cable production equipment according to claim 1 is characterized in that: A feed pipe (7) connected to the output end of the screw feeding device (1) is provided on the head shell (6); a flow groove (9) in communication with the feed pipe (7) is provided on the outer wall of the die sleeve (8), and the flow groove (9) forms an opening at the discharge end of the die sleeve (8).

3. The 110kv high voltage polypropylene insulated power cable production equipment according to claim 1 is characterized in that: It also includes a die adjustment mechanism for adjusting the position of the die (39) along the axial direction of the mold core (10).

4. The 110kv high voltage polypropylene insulated power cable production equipment according to claim 1 is characterized in that: A thread is arranged on the inner wall of the feeding end of the mold core (10); the rotary extrusion mechanism comprises a rotary ring (20) matched with the thread, a support ring (17) rotatably arranged on the rotary ring (20), and a connecting rod (14) with two ends respectively rotatably connected to the support ring (17) and the slide plate (11).

5. The 110kv high voltage polypropylene insulated power cable production equipment according to claim 4 is characterized in that: A plurality of guide rods (18) are arranged on the end surface of the support ring (17) facing away from the rotating ring (20), a plurality of guide plates (19) are arranged on the inner wall of the mold core (10), and guide holes for the guide rods (18) to pass through are arranged on the guide plates (19).

6. The 110kv high voltage polypropylene insulated power cable production equipment according to claim 4 is characterized in that: A plurality of fixing blocks (22) are arranged on the conical inner wall of the mold core (10), a support rod (23) is rotatably arranged between two fixing blocks (22), and a support frame (26) is arranged on the support rod (23).

7. The 110kv high voltage polypropylene insulated power cable production equipment according to claim 6 is characterized in that: The movable extrusion mechanism comprises a pull rope a (24), a pull rope b (25), a movable ring a (32) and a movable ring b (33); the movable ring a (32) and the movable ring b (33) are both slidably arranged on the inner wall of the mold core (10) along the axial direction of the cable (3), and the movable ring a (32) is located between the movable ring b (33) and the rotating ring (20); one end of the pull rope a (24) is connected to the movable ring a (32), and the other end is connected to and wound around the support rod (23); one end of the pull rope b (25) is connected to the movable ring b (33), and the other end is connected to and wound around the support rod (23); the winding directions of the pull rope a (24) and the pull rope b (25) are opposite and they are respectively located on both sides of the support frame (26).

8. The 110kv high voltage polypropylene insulated power cable production equipment according to claim 7 is characterized in that: A plurality of bristles (28) are arranged on the support frame (26), an avoidance groove (29) is arranged on the support frame (26), a hose (30) is passed through the plurality of avoidance grooves (29), a plurality of dust suction holes are arranged on the hose (30), a connecting pipe (31) is arranged on the hose (30), and the connecting pipe (31) is connected to an external dust suction device.

9. A method for producing a 110kv high voltage polypropylene insulated power cable, using the 110kv high voltage polypropylene insulated power cable production equipment according to claim 8, characterized in that: The following steps are involved: S1, the cable (3) is pulled through the machine head (2), and according to the diameter of the cable (3), the rotating ring (20) is rotated to make it rotate and move forward and backward, and then the slide plate (11) is driven to move through the support ring (17) and the connecting rod (14), and the slide plate (11) moves along the conical surface of the mold core (10), so that the multiple rollers a (13) squeeze the cable (3) from all sides, completing the positioning of the cable (3); S2. According to the diameter of the cable (3), the axial positions of the movable ring a (32) and the movable ring b (33) are adjusted. By tightening the pull rope a (24) or the pull rope b (25), the roller b (27) is pressed against the cable (3) to further limit the position of the cable (3). At the same time, the brush (28) cleans the surface of the cable (3). The cleaned dust is absorbed by the hose (30) to ensure the quality of the subsequent insulation layer coating. S3, the screw feeding device (1) conveys the molten insulating raw material to the die head (2) to complete the coating of the insulating layer (4).

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