Manufacturing method of polypropylene insulated wire core

Abstract

The invention relates to the field of polypropylene insulated wire cores, in particular to a polypropylene insulated wire core manufacturing method and a polypropylene insulated wire core manufacturing method, which are used for improving the internal stress of a polypropylene insulated wire core. A good cooling environment is provided for the polypropylene insulated wire core, the internal stress of the polypropylene insulated wire core is improved, and according to the elastic mechanics thin-shell theory, the winding wire coil with the adaptive diameter is selected, so that the internal stress of the polypropylene insulated wire core can be reduced, and meanwhile, the phenomenon that the diameter of the winding wire coil is too large is avoided; in addition, due to the optimized design of the winding reel, the traditional winding reel has the function of flexibly adjusting the diameter of the winding reel, the winding reel can be suitable for winding insulating wire cores with different diameters, and the adaptability is higher.

Description

Technical Field

[0001] The invention relates to the field of polypropylene insulation wire cores, in particular to a method for manufacturing polypropylene insulation wire cores. Background Art

[0002] Modified polypropylene is a thermoplastic insulating material. During the extrusion process of polypropylene insulated wires with rated voltages of 6kV to 35kV, the polypropylene insulating material will produce oriented crystallization due to high-temperature stretching. The molecular chain segments are forced to straighten from a disordered entangled state. In the subsequent rapid cooling process, the molecular chain segments "freeze", resulting in large internal stress inside the insulation.

[0003] At the same time, when the insulated wire core is subsequently wound onto a drum, due to the different bending radii inside and outside the insulated wire core, the inner side is subjected to compressive stress and the outer side is subjected to tensile stress. The electric field strength in these stress concentration areas will increase significantly, which can easily cause partial discharge and thus damage the insulation layer. The generation of internal insulation stress will significantly reduce the insulation performance of the insulated wire core;

[0004] During the actual production process of insulated wire cores, insulated wire cores of different diameters are processed according to production indicators. When the insulated wire cores of different diameters are wound onto reels, they need to be equipped with winding reels that are compatible with the diameter of the insulated wire cores. When the diameter of the insulated wire core increases, the diameter of the corresponding winding reel must also increase accordingly. However, the current winding reel diameter is a single design and cannot adapt to the winding of insulated wire cores of different diameters.

[0005] Therefore, a method for manufacturing a polypropylene insulated wire core is proposed to address the above problems. Summary of the Invention

[0006] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a method for manufacturing a polypropylene insulated wire core according to the present invention, the method for manufacturing a polypropylene insulated wire core comprises the following steps:

[0008] S1: Melt, heat and melt the insulating raw materials, and then use an extruder to wrap the molten insulating raw materials on the outer surface of the conductor;

[0009] S2: Temperature gradient design:

[0010] The maximum temperature of the extruder is limited to 195°C. This temperature range can ensure the melt fluidity of the insulation raw materials while avoiding thermal degradation.

[0011] Adopting a six-stage gradient cooling system with cross-linked pipes, the temperature of each section is controlled at 160℃→140℃→120℃→100℃→80℃→60℃, and the length of each pipe section is 3-5m. The temperature is controlled by a combination of air cooling and water cooling.

[0012] Extrusion line speed matching: The production line speed is controlled at 6-8m / min to ensure that the cooling rate of the insulation layer is ≤1.5℃ / s to avoid molecular chain freezing stress caused by sudden cooling;

[0013] Aging treatment mechanism: A constant temperature aging zone (60°C ± 2°C) is set in the terminal cooling section and maintained for 30 to 45 minutes. The molecular chain motion characteristics above the glass transition temperature of polypropylene (Tg≈-10°C) are utilized to promote the reconstruction of the crystallization area, release residual stress, and reduce the volume shrinkage of the insulation layer to below 0.3%;

[0014] S3: Rewinding. The radius of the inner shell of the reel must meet the following requirements: R ≥ 15D + ΔR, where D is the equivalent outer diameter of the insulated wire core and ΔR is the safety margin (≥ 5mm).

[0015] The winding reel shown in S3 includes a rotating shaft, and an adjustment component for adjusting the radius of the inner liner of the winding reel is symmetrically provided on the rotating shaft. Each adjustment component includes two hydraulic rods symmetrically fixed to the rotating shaft, and the output end of each hydraulic rod points to the end of the rotating shaft. The output ends of two adjacent hydraulic rods are fixed to a ring body, which is sleeved on the rotating shaft and can move along the axis of the rotating shaft.

[0016] A plurality of push rods are rotatably connected to the outer ring of each ring body, and an arc-shaped plate is provided at the end of each push rod. The arc-shaped plates are arranged in a circular array on the periphery of the rotating shaft;

[0017] The end of the arc-shaped plate is provided with a round pancake-shaped side plate, and the side plate is fixedly connected to the rotating shaft coaxially.

[0018] Preferably, a guide rod is fixedly connected to the end of each of the arc-shaped plates, and the axis of the guide rod is arranged parallel to the axis of the rotating shaft;

[0019] A plurality of strip-shaped guide holes are provided on each of the side plates. The guide holes are radially arranged on the side plates, and the guide rods are slidably connected to the guide rods.

[0020] Preferably, a plurality of support plates are fixedly connected in a circular array on the middle outer ring of the rotating shaft, the ends of each support plate are fixedly connected to two electric push rods symmetrically, and the output end of each electric push rod is fixedly connected to a plug plate;

[0021] A plurality of clamping blocks are provided on the side wall of each push rod, and the inserting plate can be inserted into the gap between two adjacent clamping blocks.

[0022] Preferably, each of the inserting plates is arranged in a U shape, and the inserting plate is inserted into the gap between two adjacent card blocks, and two sides of the inserting plate are clamped on two sides of the top rod.

[0023] Preferably, a through hole is provided inside the rotating shaft, a core shaft is provided in the through hole, a plurality of groups of protrusions are symmetrically provided on the core shaft, and the two protrusions in each group are symmetrically provided on the outer surface of the core shaft;

[0024] A plurality of telescopic holes are provided on the rotating shaft, each group of telescopic holes extends into the through hole, the two telescopic holes in each group are opposite to each other, a limit block is provided in the telescopic hole, one end of the limit block protrudes out of the telescopic hole, the other end of the limit block is fixedly connected to a spring, the end of the spring is fixedly connected to an extrusion block, the extrusion block is arranged opposite to the protrusion on the core shaft, and the extrusion block and the protrusion are both made of magnetic material, and the protrusion can adsorb the extrusion block.

[0025] Preferably, a torsion spring is sleeved on the middle position of the core shaft, one end of the torsion spring is fixed to the inner wall of the through hole, and the other end of the torsion spring is fixed to the core shaft.

[0026] Preferably, a notch is provided at a corner of the end of the arc-shaped plate, and a notch is also provided on the side of the arc-shaped plate. The notch and the notch are located on the same side of the end of the arc-shaped plate. A top screw is provided in the notch. The top screw thread passes through the arc-shaped plate and extends into the notch, and the end of the top screw is rotatably connected to the top plate.

[0027] Preferably, a strip hole is provided on each of the two side panels, the strip holes on the two side panels are arranged opposite to each other, and an extrusion rod is provided in the strip hole, the end of the extrusion rod extends to the outside of the side panel, and the end of the extrusion rod is fastened to the side panel by a nut;

[0028] A plurality of locking blocks are slidably connected to the extrusion rod, and arc-shaped grooves are provided on the surfaces of the locking blocks, and the grooves are used for extruding on the surface of the cable.

[0029] Preferably, a support assembly is symmetrically provided on the rotating shaft, and the support assembly is arranged at a position close to the end of the arc plate. The support assembly includes a plurality of sleeves perpendicular to the axis of the rotating shaft, the sleeves are fixed on the rotating shaft, a rod body is sleeved in the sleeves, and the end of the rod body is fixed to the arc plate.

[0030] Preferably, each section of the cross-linked pipe adopts a double-layer spiral guide structure pipe, the inner layer of each section of the cross-linked pipe is provided with a ceramic wear-resistant coating, and the outer layer of each section of the cross-linked pipe is configured with a PID intelligent temperature control module.

[0031] The present invention is beneficial in that:

[0032] 1. In the present invention, the method for manufacturing a polypropylene insulated wire core optimizes the temperature gradient design, provides a good cooling environment for the polypropylene insulated wire core, improves the internal stress of the polypropylene insulated wire core, and selects a winding reel with an adapted diameter based on the thin shell theory of elastic mechanics. This not only reduces the internal stress of the polypropylene insulated wire core, but also prevents the winding reel from having an excessively large diameter, thereby wasting materials for producing the winding reel. Furthermore, the optimized design of the winding reel gives the traditional winding reel the function of flexibly adjusting its diameter, making it suitable for winding insulated wire cores of different diameters and having greater adaptability.

[0033] 2. In the present invention, the output end of the designed electric push rod drives the plug plate to move toward the push rod. The plug plate is inserted between two adjacent blocks and presses against the push rod to support the push rod, thereby supporting and stabilizing the arc plate, further improving the stability of the arc plate, and being able to reel in insulated wire cores with larger diameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of the method for manufacturing a polypropylene insulated wire core according to the present invention;

[0035] Figure 2 A perspective view of a take-up reel according to the present invention;

[0036] Figure 3 Schematic diagram of the internal structure of the winding reel in the present invention;

[0037] Figure 4 This is a three-dimensional diagram of the coordination of multiple curved plates in the present invention;

[0038] Figure 5 It is a front view of the adjustment component of the present invention;

[0039] Figure 6 is a perspective view of the adjustment assembly of the present invention;

[0040] Figure 7 This is a three-dimensional diagram of the coordination of the side panels and the curved panels of the present invention;

[0041] Figure 8 A perspective view of a side panel of the present invention;

[0042] Figure 9 A three-dimensional diagram of the curved plate of the present invention;

[0043] Figure 10 A three-dimensional diagram of the cooperation between the insulated wire core and the curved plate in the present invention;

[0044] Figure 11 A three-dimensional diagram of the cooperation between the inserting plate and the ejector rod in the present invention;

[0045] Figure 12 A perspective view of the core shaft of the present invention;

[0046] Figure 13 is a side view of the core shaft of the present invention;

[0047] Figure 14 is a cross-sectional view of the core shaft of the present invention;

[0048] Figure 15 It is a schematic diagram of the cooperation between the limit block and the core shaft in the present invention.

[0049] In the figure: 101, insulated wire core; 1, winding drum; 2, rotating shaft; 3, hydraulic rod; 4, push rod; 5, arc plate; 6, side plate; 7, guide rod; 8, guide hole; 9, support plate; 10, electric push rod; 11, plug plate; 12, clamping block; 13, through hole; 14, core shaft; 15, protrusion; 16, telescopic hole; 17, limit block; 18, spring; 19, extrusion block; 20, torsion spring; 21, notch; 22, notch; 23, push screw; 24, top plate; 25, strip hole; 26, extrusion rod; 27, locking block; 28, sleeve; 29, rod body. DETAILED DESCRIPTION

[0050] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0051] Reference Figure 1 - Figure 9 A method for manufacturing a polypropylene insulated wire core is used to improve the internal stress of a polypropylene insulated wire core 101, and the method comprises the following steps:

[0052] S1: Melt, heat and melt the insulating raw materials, and then use an extruder to wrap the molten insulating raw materials on the outer surface of the conductor;

[0053] S2: Temperature gradient design:

[0054] The maximum temperature of the extruder is limited to 195°C. This temperature range can ensure the melt fluidity of the insulation raw materials while avoiding thermal degradation.

[0055] Adopting a six-stage gradient cooling system with cross-linked pipes, the temperature of each section is controlled at 160℃→140℃→120℃→100℃→80℃→60℃, and the length of each pipe section is 3-5m. The temperature is controlled by a combination of air cooling and water cooling.

[0056] Extrusion line speed matching: based on a cross section of 300mm 2 Taking the insulated wire core 101 as an example, the production speed is controlled at 6-8m / min to ensure that the cooling rate of the insulation layer is ≤1.5℃ / s to avoid molecular chain freezing stress caused by sudden cooling;

[0057] Aging treatment mechanism: A constant temperature aging zone (60°C ± 2°C) is set in the terminal cooling section and maintained for 30 to 45 minutes. The molecular segment motion characteristics of polypropylene (with a glass transition temperature Tg of -10°C or above) are utilized to promote the reconstruction of the crystallization area, release residual stress, and reduce the volume shrinkage of the insulation layer to below 0.3%.

[0058] S3: Winding. According to the thin shell theory of elastic mechanics, the inner radius of the winding reel 1 must meet the following requirements: R ≥ 15D + ΔR, where D is the equivalent outer diameter of the insulated wire core 101 and ΔR is a safety margin ≥ 5 mm.

[0059] The winding reel 1 shown in S3 includes a rotating shaft 2, on which are symmetrically provided adjustment components for adjusting the radius of the inner liner of the winding reel 1. Each adjustment component includes two hydraulic rods 3 symmetrically fixed to the rotating shaft 2. The output end of each hydraulic rod 3 points to the end of the rotating shaft 2, and the output ends of two adjacent hydraulic rods 3 are fixedly connected to a ring body 30. The ring body 30 is sleeved on the rotating shaft 2 and can move along the axis of the rotating shaft 2.

[0060] A plurality of push rods 4 are rotatably connected to the outer ring of each ring body 30, and an arc-shaped plate 5 is provided at the end of each push rod 4. The arc-shaped plates 5 are arranged in a circular array around the outer periphery of the rotating shaft 2;

[0061] The end of the arc-shaped plate 5 is provided with a round pancake-shaped side plate 6, and the side plate 6 is fixedly connected to the rotating shaft 2 coaxially;

[0062] The winding reel 1 is provided with a flexible adjustment of the winding diameter, and can be suitable for winding polypropylene insulated wire cores 101 of different diameters. The specific operation is to drive the hydraulic rod 3, and the hydraulic rod 3 is driven by hydraulic oil. An oil pipe can be provided on the side plate 6, and the oil pipe is connected to the hydraulic rod 3;

[0063] Two adjacent hydraulic rods 3 simultaneously push the ring body 30, as shown in the figure, and the ring body 30 moves toward the end of the rotating shaft 2. At the same time, the ring body 30 pushes the push rod 4, and the push rod 4 pushes the arc-shaped plate 5 outward. At this time, the diameter of the circle surrounded by the multiple arc-shaped plates 5 gradually increases, which is suitable for winding polypropylene insulated wire cores 101 with larger diameters;

[0064] The manufacturing method of the polypropylene insulated wire core 101 optimizes the temperature gradient design, provides a good cooling environment for the polypropylene insulated wire core 101, improves the internal stress of the polypropylene insulated wire core 101, and selects a winding reel 1 with an adapted diameter based on the elastic mechanics thin shell theory, which not only can reduce the internal stress of the polypropylene insulated wire core 101, but also will not cause the diameter of the winding reel 1 to be too large, resulting in waste of production materials of the winding reel 1. Furthermore, the optimized design of the winding reel 1 gives the traditional winding reel 1 the function of flexibly adjusting its diameter, and can be suitable for winding insulated wire cores 101 with different diameters, and has stronger adaptability.

[0065] Reference Figure 8 - Figure 10 , each end of the arc-shaped plate 5 is fixedly connected to a guide rod 7, and the axis of the guide rod 7 is arranged parallel to the axis of the rotating shaft 2;

[0066] A plurality of strip-shaped guide holes 8 are provided on each of the side plates 6 , and the guide holes 8 are radially arranged on the side plates 6 , and the guide rods 7 are slidably connected to the guide rods 7 ;

[0067] In order to improve the overall performance of the winding reel 1, that is, to improve its stability and to be able to wind up the polypropylene insulated wire core 101 with a larger diameter, the arc plate 5 and the side plate 6 are movably connected together;

[0068] The side plate 6 is fixed to the rotating shaft 2, and the guide hole 8 opened on the side plate 6 is used to connect the guide rod 7. The guide rod 7 can slide along the guide bar and move as the arc plate 5 expands and moves toward the outside of the rotating shaft 2, limiting the movement dimension of the arc plate 5, so that the arc plate 5 can only move along the length direction of the guide hole 8, constraining the arc plate 5, and preventing the arc plate 5 from tilting, which affects the roundness of the winding reel 1. If the roundness of the winding reel 1 is destroyed, that is, the arc plate 5 is tilted, when the insulated core 101 is wound, especially at the position where the arc plate 5 is tilted, the arc plate 5 is likely to cause local extrusion of the insulated core 101, thereby damaging the outer surface of the insulated core 101.

[0069] Reference Figure 3 - Figure 6 A plurality of support plates 9 are fixedly connected to the circumferential array on the middle outer ring of the rotating shaft 2. The end of each support plate 9 is fixedly connected to two electric push rods 10 symmetrically. The output end of each electric push rod 10 is fixedly connected to a plug-in board 11.

[0070] A plurality of blocks 12 are provided on the side wall of each of the top rods 4, and the inserting plate 11 can be inserted into the gap between two adjacent blocks 12;

[0071] The support plate 9 is used to mount the electric push rod 10 on the rotating shaft 2. The wire of the electric push rod 10 extends to the side plate 6. The wire is connected to the external power supply to drive the electric push rod 10 to execute;

[0072] The hydraulic pipe connected to the hydraulic rod 3 extends to the side plate 6, and a valve is set at the end of the hydraulic pipe to lock the internal oil pressure of the hydraulic rod 3. After adjusting the outward movement of the arc plate 5, the hydraulic pipe is evacuated, the valve is closed, and then the electric push rod 10 is driven. The output end of the electric push rod 10 drives the plug plate 11 to move toward the push rod 4. The plug plate 11 is inserted between two adjacent blocks 12 and presses on the push rod 4 to support the push rod 4, thereby supporting and stabilizing the arc plate 5, further improving the stability of the arc plate 5, and being able to reel in the insulated wire core 101 with a larger diameter.

[0073] Reference Figure 5 and Figure 11, each of the inserting plates 11 is arranged in a U shape, the inserting plate 11 is inserted into the gap between two adjacent card blocks 12, and both sides of the inserting plate 11 are clamped on both sides of the top rod 4;

[0074] The plug-in plate 11 is pressed against the ejector rod 4, and at the same time, the plug-in plate 11 is constrained between two adjacent blocks 12, and the two sides of the plug-in plate 11 are half wrapped around the two sides of the ejector rod 4, further constraining the ejector rod 4 and the plug-in plate 11 to prevent the plug-in plate 11 from pressing against the ejector rod 4 and sliding away from the ejector rod 4, causing the electric push rod 10 to lose its squeezing support on the ejector rod 4.

[0075] Reference Figure 5 and Figure 6 ,as well as Figure 12 - Figure 15 The rotating shaft 2 has a through hole 13 formed inside, a core shaft 14 is provided in the through hole 13, and a plurality of groups of protrusions 15 are symmetrically provided on the core shaft 14, and the two protrusions 15 in each group are centrally symmetrically provided on the outer surface of the core shaft 14;

[0076] The rotating shaft 2 is provided with a plurality of telescopic holes 16, each of which extends into the through hole 13. The two telescopic holes 16 in each group are opposite to each other. A limit block 17 is provided in the telescopic hole 16. One end of the limit block 17 protrudes out of the telescopic hole 16. The other end of the limit block 17 is fixedly connected to a spring 18. The end of the spring 18 is fixedly connected to an extrusion block 19. The extrusion block 19 is arranged opposite to the protrusion 15 on the core shaft 14. Both the extrusion block 19 and the protrusion 15 are made of magnetic material, and the protrusion 15 can adsorb the extrusion block 19.

[0077] When the diameter of the winding drum 1 needs to be expanded, the hydraulic rod 3 is directly driven, and the hydraulic rod 3 pushes the ring body 30 to move along the rotating shaft 2. At this time, the ring body 30 will squeeze the inclined surface of the limit block 17 and pass over the limit block 17. After the diameter adjustment of the winding drum 1 is completed, the inner side of the ring body 30 is pressed against the limit block 17, and the ring body 30 is restricted and constrained to be stable, and the auxiliary hydraulic rod 3 is used to squeeze and constrain the ring body 30. When the pressure inside the hydraulic rod 3 is accidentally released, the limit block 17 can play the role of limiting the ring body 30, and also constrain the arc plate 5; six The prism, the core shaft 14 is rotatably connected in the through hole 13. By using a hexagonal socket wrench set at the end of the core shaft 14, the twisted core shaft 14 is rotated in the through hole 13, and the multiple groups of protrusions 15 on the core shaft 14 will move away from the telescopic hole 16. At this time, the protrusions 15 no longer squeeze the extrusion block 19. The protrusions 15 attract the extrusion block 19 to move toward the through hole 13, and the limit block 17 retracts into the telescopic hole 16. The limit block 17 no longer protrudes from the surface of the rotating shaft 2. At this time, the hydraulic rod 3 is driven to pull the ring body 30 to move toward the middle direction of the rotating shaft 2, and the ring body 30 can easily move along the axis of the rotating shaft 2.

[0078] Reference Figure 12 and Figure 14A torsion spring 20 is sleeved in the middle of the core shaft 14. One end of the torsion spring 20 is fixed to the inner wall of the through hole 13, and the other end of the torsion spring 20 is fixed to the core shaft 14.

[0079] A torsion spring 20 is provided on the core shaft 14. The torsion force of the torsion spring 20 twists the core shaft 14 so that the protrusion 15 on the core shaft 14 is always opposite to the telescopic hole 16, that is, the protrusion 15 on the core shaft 14 always pushes the limit block 17 outward, so that the limit block 17 always protrudes from the outer surface of the rotating shaft 2. Only when the core shaft 14 is rotated with a hexagonal socket wrench and the torsion force of the hexagonal socket wrench is maintained, can the limit block 17 be retracted into the telescopic hole 16. This design allows the limit block 17 to protrude from the outer surface of the rotating shaft 2 without external interference, and can stably limit the position of the ring body 30, which is also a measure to ensure the stability of the ring body 30.

[0080] Reference Figure 7 、 Figure 9 and Figure 10 A notch 21 is provided at one corner of the end of the arc-shaped plate 5, and a notch 22 is further provided on the side of the arc-shaped plate 5. The notch 22 and the notch 21 are located on the same side of the end of the arc-shaped plate 5. A top screw 23 is provided in the notch 22. The top screw 23 is threaded through the arc-shaped plate 5 and extends into the notch 21. The end of the top screw 23 is rotatably connected to the top plate 24.

[0081] Taking into account that the insulated wire core 101 needs to be fixed on the winding reel 1 in the early stage of winding, so that the insulated wire core 101 can be effectively pulled and wound, a structure for fixing the insulated wire core 101 is set on one of the arc plates 5, and the end of the insulated wire core 101 is inserted into the notch 21, and then the top screw 23 is rotated, the top screw 23 pushes the top plate 24, and squeezes the insulated wire core 101 on the side plate 6. This structural design can firstly achieve stable squeezing of the end of the insulated wire core 101, and at the same time can also squeeze and fix insulated wire cores 101 with different diameters. Moreover, it is only necessary to squeeze and fix a small section of the end of the insulated wire core 101. When the insulated wire core 101 is put into use in the later stage, it will not affect the use of this section of the insulated wire core 101, thereby avoiding waste.

[0082] Reference Figure 2 、 Figure 3 、 Figure 7 and Figure 8 ,as well as Figure 12 - Figure 15 , each of the two side panels 6 has a strip hole 25, the strip holes 25 on the two side panels 6 are arranged opposite to each other, and an extrusion rod 26 is provided in the strip hole 25, the end of the extrusion rod 26 extends to the outside of the side panel 6, and the end of the extrusion rod 26 is fastened to the side panel 6 by a nut;

[0083] The squeezing rod 26 is slidably connected to a plurality of locking blocks 27 , and the surface of the locking block 27 is provided with an arc-shaped groove, which is used to squeeze the surface of the cable;

[0084] After the winding reel 1 finishes winding the insulated wire core 101, the end of the insulated wire core 101 is in a free state and also needs to be temporarily fixed to prevent the entire roll of the insulated wire core 101 from loosening. In this embodiment, an extrusion rod 26 and a locking block 27 are provided on the side plate 6, which can squeeze and lock the end of the insulated wire core 101. The specific operation is to pass the extrusion rod 26 through the bar-shaped holes 25 on the two side plates 6, and press the locking block 27 on the end position of the insulated wire core 101. The multiple locking blocks 27 provided can squeeze the locking blocks 27 separately on the surface of the insulated wire core 101, specifically on the coil wound on the end of the insulated wire core 101, and then lock the extrusion rod 26 on the outer wall of the side plate 6 through a nut to stabilize the extrusion rod 26, so that the locking block 27 can be stably squeezed on the end of the insulated wire core 101. The operation is simple, and the position of the extrusion rod 26 can be flexibly adjusted according to the diameter of the coil wound on the insulated wire core 101.

[0085] Reference Figure 3 and Figure 4 The rotating shaft 2 is symmetrically provided with a support assembly, which is arranged near the end of the arc-shaped plate 5 and includes a plurality of sleeves 28 perpendicular to the axis of the rotating shaft 2. The sleeves 28 are fixed to the rotating shaft 2. A rod 29 is sleeved in the sleeves 28. The end of the rod 29 is fixed to the arc-shaped plate 5.

[0086] The support assembly is provided to limit the offset of the arc plate 5. One end of the rod body 29 is fixed to the back side of the end of the arc plate 5, and the other end of the rod body 29 is slidably connected to the sleeve 28, and the sleeve 28 is vertically fixed to the rotating shaft 2, limiting the rod body 29 to move only in the radial direction of the rotating shaft 2, thereby further constraining the offset of the arc plate 5, that is, the arc plate 5 can only move in the radial direction of the rotating shaft 2, thereby improving the stability of the circle surrounded by multiple arc plates 5.

[0087] Each cross-linked pipe section adopts a double-layer spiral guide structure pipe, the inner layer of each cross-linked pipe section is provided with a ceramic wear-resistant coating, and the outer layer of each cross-linked pipe section is equipped with a PID intelligent temperature control module;

[0088] The system utilizes a double-layer spiral flow-guiding structure, with a ceramic wear-resistant coating on the inner layer and a PID intelligent temperature control module on the outer layer, achieving a temperature fluctuation accuracy of ±1°C. This optimizes the cooling medium flow rate, ensuring uniform heat dissipation under laminar flow conditions and improving cooling stability.

[0089] Working principle:

[0090] The temperature gradient is designed to limit the maximum temperature of the extruder to 195°C. This temperature range can not only ensure the melt fluidity of the insulating raw materials, but also avoid thermal degradation; a six-stage gradient cooling method is adopted for cross-linked pipes, with the temperature of each section controlled at 160°C → 140°C → 120°C → 100°C → 80°C → 60°C, and the length of each pipe section is 3-5m. The temperature is cooled by a combination of air cooling and water cooling; extrusion line speed matching: taking the insulated wire core 101 with a diameter of 20mm as an example, the production line speed is controlled at 6-8m / min to ensure that the cooling rate of the insulation layer is ≤1.5°C / s to avoid molecular chain freezing stress caused by sudden cooling; aging treatment mechanism: a constant temperature aging zone (60°C ± 2°C) is set in the terminal cooling section and maintained for 30-45 minutes. The molecular chain motion characteristics of polypropylene above the glass transition temperature Tg≈-10°C are used to promote the reconstruction of the crystallization area, release residual stress, and reduce the volume shrinkage of the insulation layer to below 0.3%;

[0091] At the same time, a winding reel 1 with a variable winding diameter is designed, which can be used for winding polypropylene insulated wire cores 101 with different diameters. The specific operation is to drive the hydraulic rod 3, and the hydraulic rod 3 is driven by hydraulic oil. An oil pipe can be set on the side plate 6, and the oil pipe is connected to the hydraulic rod 3;

[0092] Two adjacent hydraulic rods 3 simultaneously push the ring body 30, as shown in the figure, and the ring body 30 moves toward the end of the rotating shaft 2. At the same time, the ring body 30 pushes the push rod 4, and the push rod 4 pushes the arc-shaped plate 5 outward. At this time, the diameter of the circle surrounded by the multiple arc-shaped plates 5 gradually increases, which is suitable for winding polypropylene insulated wire cores 101 with larger diameters;

[0093] The manufacturing method of the polypropylene insulated wire core 101 optimizes the temperature gradient design, provides a good cooling environment for the polypropylene insulated wire core 101, improves the internal stress of the polypropylene insulated wire core 101, and selects a winding reel 1 with an adapted diameter based on the elastic mechanics thin shell theory, which not only can reduce the internal stress of the polypropylene insulated wire core 101, but also will not cause the diameter of the winding reel 1 to be too large, resulting in waste of production materials of the winding reel 1. Furthermore, the optimized design of the winding reel 1 gives the traditional winding reel 1 the function of flexibly adjusting its diameter, and can be suitable for winding insulated wire cores 101 with different diameters, and has stronger adaptability.

[0094] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a polypropylene insulated wire core, characterized in that: The polypropylene insulated wire core manufacturing method comprises the following steps: S1: Melt, heat and melt the insulating raw materials, and then use an extruder to wrap the molten insulating raw materials on the outer surface of the conductor; S2: Temperature gradient design: The maximum temperature of the extruder is limited to 195°C. This temperature range can ensure the melt fluidity of the insulation raw materials while avoiding thermal degradation. Adopting a six-stage gradient cooling system with cross-linked pipes, the temperature of each section is controlled at 160℃→140℃→120℃→100℃→80℃→60℃, and the length of each pipe section is 3-5m. The temperature is controlled by a combination of air cooling and water cooling. Extrusion line speed matching: The production line speed is controlled at 6-8m / min to ensure that the cooling rate of the insulation layer is ≤1.5℃ / s to avoid molecular chain freezing stress caused by sudden cooling; Aging treatment mechanism: A constant temperature aging zone (60°C ± 2°C) is set in the terminal cooling section and maintained for 30 to 45 minutes. The molecular chain motion characteristics above the glass transition temperature of polypropylene (Tg≈-10°C) are utilized to promote the reconstruction of the crystallization area, release residual stress, and reduce the volume shrinkage of the insulation layer to below 0.3%; S3: Rewinding. The inner radius of the reel (1) must satisfy the following requirements: R ≥ 15D + ΔR, where D is the equivalent outer diameter of the insulated wire core (101) and ΔR is the safety margin (≥ 5 mm). The winding reel (1) shown in S3 includes a rotating shaft (2), and an adjusting assembly for adjusting the radius of the inner shell of the winding reel (1) is symmetrically provided on the rotating shaft (2), and each adjusting assembly includes two hydraulic rods (3) symmetrically fixed on the rotating shaft (2), the output end of each hydraulic rod (3) points to the end of the rotating shaft (2), and the output ends of two adjacent hydraulic rods (3) are fixedly connected to a ring body (30), and the ring body (30) is sleeved on the rotating shaft (2) and can move along the axis direction of the rotating shaft (2); A plurality of push rods (4) are rotatably connected to the outer ring of each of the ring bodies (30), and an arc-shaped plate (5) is provided at the end of each push rod (4). The arc-shaped plates (5) are arranged in a circular array on the periphery of the rotating shaft (2); A circular side plate (6) is provided at the end of the arc-shaped plate (5), and the side plate (6) is fixedly connected to the rotating shaft (2) coaxially.

2. The method for manufacturing a polypropylene insulated wire core according to claim 1, wherein: A guide rod (7) is fixedly connected to the end of each arc-shaped plate (5), and the axis of the guide rod (7) is arranged parallel to the axis of the rotating shaft (2); A plurality of strip-shaped guide holes (8) are provided on each of the side plates (6). The guide holes (8) are radially arranged on the side plates (6), and the guide rods (7) are slidably connected to the guide rods (7).

3. The method for manufacturing a polypropylene insulated wire core according to claim 2, wherein: A plurality of support plates (9) are fixedly connected in a circular array on the middle outer ring of the rotating shaft (2), the end of each support plate (9) is fixedly connected to two electric push rods (10) symmetrically, and the output end of each electric push rod (10) is fixedly connected to a plug plate (11); A plurality of clamping blocks (12) are provided on the side wall of each of the push rods (4), and the inserting plate (11) can be inserted into the gap between two adjacent clamping blocks (12).

4. The method for manufacturing a polypropylene insulated wire core according to claim 3, wherein: Each of the inserting plates (11) is arranged in a U shape. The inserting plate (11) is inserted into the gap between two adjacent clamping blocks (12), and both sides of the inserting plate (11) are clamped on both sides of the top rod (4).

5. The method for manufacturing a polypropylene insulated wire core according to claim 3, wherein: A through hole (13) is provided inside the rotating shaft (2), a core shaft (14) is provided in the through hole (13), a plurality of groups of protrusions (15) are symmetrically provided on the core shaft (14), and two protrusions (15) in each group are centrally symmetrically provided on the outer surface of the core shaft (14); The rotating shaft (2) is provided with a plurality of telescopic holes (16), each group of telescopic holes (16) extends into the through hole (13), the two telescopic holes (16) in each group are opposite to each other, a limiting block (17) is provided in the telescopic hole (16), one end of the limiting block (17) protrudes out of the telescopic hole (16), the other end of the limiting block (17) is fixedly connected to a spring (18), the end of the spring (18) is fixedly connected to an extrusion block (19), the extrusion block (19) is arranged opposite to the protrusion (15) on the core shaft (14), the extrusion block (19) and the protrusion (15) are both made of magnetic material, and the protrusion (15) can adsorb the extrusion block (19).

6. The method for manufacturing a polypropylene insulated wire core according to claim 5, characterized in that: A torsion spring (20) is sleeved on the middle position of the core shaft (14), one end of the torsion spring (20) is fixedly connected to the inner wall of the through hole (13), and the other end of the torsion spring (20) is fixedly connected to the core shaft (14).

7. The method for manufacturing a polypropylene insulated wire core according to claim 2, wherein: A notch (21) is provided at one corner of the end of the arc-shaped plate (5), and a notch (22) is further provided on the side of the arc-shaped plate (5). The notch (22) and the notch (21) are located on the same side of the end of the arc-shaped plate (5). A top screw (23) is provided in the notch (22). The top screw (23) is threadedly passed through the arc-shaped plate (5) and extends into the notch (21), and the end of the top screw (23) is rotatably connected to the top plate (24).

8. The method for manufacturing a polypropylene insulated wire core according to claim 2, wherein: A strip hole (25) is provided on each of the two side plates (6), the strip holes (25) on the two side plates (6) are arranged opposite to each other, and an extrusion rod (26) is provided in the strip hole (25), the end of the extrusion rod (26) extends to the outside of the side plate (6), and the end of the extrusion rod (26) is fastened to the side plate (6) by a nut; A plurality of locking blocks (27) are slidably connected to the extrusion rod (26), and arc-shaped grooves are provided on the surfaces of the locking blocks (27), and the grooves are used for extruding on the surface of the cable.

9. The method for manufacturing a polypropylene insulated wire core according to claim 5, characterized in that: A support assembly is symmetrically provided on the rotating shaft (2), and the support assembly is arranged at a position close to the end of the arc plate (5). The support assembly includes a plurality of sleeves (28) perpendicular to the axis of the rotating shaft (2). The sleeves (28) are fixedly connected to the rotating shaft (2). A rod body (29) is sleeved inside the sleeve (28), and the end of the rod body (29) is fixedly connected to the arc plate (5).

10. The method for manufacturing a polypropylene insulated wire core according to claim 1, characterized in that: Each section of the cross-linked pipeline adopts a double-layer spiral guide structure pipeline, the inner layer of each section of the cross-linked pipeline is provided with a ceramic wear-resistant coating, and the outer layer of each section of the cross-linked pipeline is configured with a PID intelligent temperature control module.

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