Preparation method of micro-corrugated aluminum sheath cable and forming equipment of micro-corrugated aluminum sheath cable

Abstract

The invention provides a preparation method of a micro-corrugated aluminum sleeve cable and forming equipment thereof. The preparation method comprises the following steps: aluminum strip pretreatment and progressive micro-corrugated embossing: performing pre-forming embossing in a blooming stage and controlling the deformation amount of an aluminum strip to be 25-40% of the final total deformation amount, performing depth-setting embossing in a finish rolling stage, performing flattening treatment on an embossed sharp corner of the aluminum strip in a shaping stage, and rolling the aluminum strip to form a micro-corrugated aluminum sleeve cable. And the reel pipe is welded with laser. The anti-bending and anti-pressure capabilities close to those of a traditional corrugated aluminum sleeve are provided, the problem of creases of a smooth aluminum sleeve is avoided, effective surface contact with the buffer layer is increased, the current density is low, and the ablation risk is avoided.

Description

Technical Field

[0001] This invention relates to a preparation method and forming equipment, particularly a preparation method and forming equipment for micro-wrinkled aluminum-sheathed cables, belonging to the field of cable production technology. Background Technology

[0002] In the field of power transmission and communication cables, aluminum sheaths have become a key component of cable protection structures due to their lightweight nature and excellent electromagnetic shielding performance. However, traditional aluminum sheath manufacturing technology has long been constrained by the difficulty in synergistically optimizing flexibility, mechanical strength, and processing precision, becoming a major obstacle to industry development. High-voltage / ultra-high-voltage power cables require metal sheaths (such as aluminum sheaths) to achieve radial waterproofing and mechanical protection. Micro-wrinkled structures can enhance the cable's bending flexibility, prevent sheath cracking during laying, and maintain its airtightness.

[0003] Traditional corrugated aluminum sleeves are formed by longitudinally wrapping aluminum strips and then argon-arc welding, followed by corrugation rolling. During the corrugation process, uneven corrugation depth can occur. Since the inner corrugations of the corrugated aluminum sleeve make point and line contact with the wire core, uneven corrugation depth can cause indentations on the surface of the cross-linked wire core.

[0004] The smooth aluminum sleeve is primarily constructed using longitudinal welding. The aluminum sheet is rolled and welded into a smooth round tube, which is then drawn without any rolling marks. It achieves full surface contact (face contact) with the buffer layer, and the gapless design enhances structural compactness. The smooth aluminum sleeve is prone to wrinkling when bent; therefore, careful control of the bending radius is necessary during installation.

[0005] Problems with smooth aluminum sleeves: During production, the smooth aluminum sleeve and the outer sheath need to be manufactured in series. The bonding of the smooth aluminum sleeve and the HDPE outer sheath requires precise control of the adhesive layer thickness, temperature, and pressure. The smooth aluminum sleeve and the buffer layer are in surface contact, resulting in weak mechanical impact protection; therefore, careful control of the bending radius is necessary during installation.

[0006] Problems with corrugated aluminum sheaths: During cable production, the corrugation depth of the corrugations in the aluminum sheath is uneven, resulting in uneven stress on the inner side of the sheath in contact with the conductor, which can cause indentations on the surface of the cross-linked conductor. However, the ripples and troughs on the surface of the corrugated aluminum sheath also provide a certain degree of compressive strength.

[0007] Differences in bending performance: Corrugated aluminum sheaths offer better bending performance, with the corrugated structure providing room for elastic deformation. The bending radius during cable installation is 25D, making it suitable for complex laying paths. Smooth aluminum sheaths have a bending radius of 20D during installation, but they are prone to wrinkling when bent, requiring a composite structure of "aluminum sheath - hot melt adhesive - outer sheath" to enhance bending resistance.

[0008] Smooth aluminum sheaths and corrugated aluminum sheaths each have their own advantages and disadvantages. If the advantages of both can be combined and their respective defects can be solved, a higher-performance aluminum sheathed cable can be obtained. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a method for preparing micro-wrinkled aluminum-sheathed cables and a forming equipment thereof, so as to obtain an aluminum-sheathed cable with better performance.

[0010] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for preparing a micro-wrinkled aluminum-sheathed cable includes the following steps: S1. Aluminum strip pretreatment; S2. Progressive micro-wrinkle rolling: Pre-forming rolling is carried out in the initial rolling stage and the deformation of the aluminum strip is controlled at 25% to 40% of the final total deformation. The depth rolling is carried out in the finishing rolling stage, and the sharp corners of the aluminum strip rolling are flattened in the shaping stage. S3, pipe rolling and laser welding.

[0011] Further, step S1 specifically includes: aluminum strip pretreatment comprising aluminum strip cleaning, aluminum strip straightening and aluminum strip shearing; Aluminum strip cleaning: Electrostatic dust removal is used to remove dust from the surface of the aluminum strip, and ultrasonic cleaning technology combined with isoacetone solution is used to clean and remove oil stains from the surface of the aluminum strip; Aluminum strip straightening: The aluminum strip is straightened by using multiple sets of guide rollers and a track straightening method to eliminate residual stress; Aluminum strip cutting: Cut the aluminum strip to the preset width and chamfer the edges of the aluminum strip.

[0012] Furthermore, the chamfer has a dimension of C0.1×45°.

[0013] Further, step S2 specifically includes: In the initial rolling stage, large-radius circular arc rolls are used for pre-forming of the grooves, and the deformation of the aluminum strip is controlled within 25% to 40% of the final total deformation. In the finishing rolling stage, toothed involute rolls are used to perform fixed-depth texturing, so that the wrinkle depth h = (0.3~0.8)t, where t is the thickness of the aluminum strip; During the shaping stage, a polymer elastic roller is used to flatten the sharp corners of the aluminum strip's rolled grooves, so that the peaks and valleys of the rolled grooves form rounded corners with a radius of R = 0.4 to 0.6 mm, and the final rolled groove depth is 0.5 to 1.5 mm.

[0014] Furthermore, the tooth angle α of the toothed involute roll is 75°±1°.

[0015] Furthermore, the tumbling pressure of the polymer elastic roller is 0.8-1.2 MPa.

[0016] Furthermore, step S3 specifically involves: the aluminum strip being rolled into a tubular shape, and then simultaneously subjected to laser welding under argon protection.

[0017] The laser welding uses a laser with a power of 3kW or higher, a laser wavelength of 1070 nm, a laser welding speed of (15±5) m / min, an argon flow rate of (20±5) L / min, and a laser welding penetration depth of aluminum strip thickness + 0.2 mm.

[0018] A forming device for preparing micro-wrinkled aluminum-sheathed cables includes a wire feeding frame, a tape feeding machine, a straightening machine, a corrugating machine, a tube winding machine, a laser welding machine, and a take-up frame arranged sequentially along the transmission direction of the micro-wrinkled aluminum-sheathed cable. The corrugating machine includes a primary pre-rolling machine, a secondary finishing mill, and a tertiary fixed mill. The primary pre-rolling machine uses arc rolls, the secondary finishing mill uses toothed involute rolls with a tooth angle α = 75° ± 1°, and the tertiary fixed mill uses polymer elastic rolls.

[0019] Furthermore, it also includes a tension detection unit, a pressure sensor, a PLC, a weld seam tracking unit, a weld seam detection unit, and a control cloud platform. The tension detection unit collects the tension of the aluminum strip released by the strip feeding machine, the pressure sensor collects the pressure of the rolling mill rolls and uploads it to the PLC, the weld seam tracking unit tracks the distance between the laser welding machine's welding torch and the aluminum tube in real time, the weld seam detection unit monitors the welding quality of the aluminum tube in real time, and the tension detection unit, PLC, weld seam tracking unit, and weld seam detection unit are connected to the control cloud platform and upload the collected information to the control cloud platform in real time.

[0020] Compared with the prior art, the present invention has the following advantages and effects: 1. This invention provides a method for preparing a micro-wrinkled aluminum sheath cable and its forming equipment. Shallow grooves with a depth of 0.5 to 1.5 mm are formed on the surface of the aluminum sheath (the traditional wrinkle depth is 3.0 to 6.5 mm), which combines the advantages of both smooth aluminum sheath cables and wrinkled aluminum sheath cables. The micro-wrinkled aluminum sheath provides bending and compressive strength close to that of traditional wrinkled aluminum sheaths, avoids the crease problem of smooth aluminum sheaths, and increases the effective surface contact with the buffer layer. It also has a low current density and avoids the risk of ablation. 2. This invention adopts a process of first corrugating aluminum strip and then welding the coiled tube, which solves the problem of surface indentation of cross-linked wire cores with wrinkled aluminum sleeves in the prior art. Moreover, the three-stage corrugation process of initial rolling, fine rolling and shaping stage achieves the control of wrinkle depth fluctuation within ±5%, while ensuring that the radius R of the edge rounded corner is greater than or equal to 0.3mm, effectively avoiding stress concentration and further improving the stability and reliability of the product. In addition, the use of micro-wrinkle and peak-valley rounded corner process increases the contact area between the corrugation and the cable core, avoiding carbonization and ablation caused by local overheating at the buffer layer. 3. This invention reduces reliance on manual labor, and the process parameters are dynamically collected and uploaded to the cloud, facilitating subsequent improvements and optimizations. Attached Figure Description

[0021] Figure 1 This is a flowchart of a method for preparing a micro-wrinkled aluminum-sheathed cable according to the present invention.

[0022] Figure 2 This is a schematic diagram of the progressive micro-wrinkle rolling pattern of the present invention.

[0023] Figure 3 This is a schematic diagram of a forming device for a micro-wrinkled aluminum sheathed cable according to the present invention. Detailed Implementation

[0024] To illustrate in detail the technical solutions adopted by the present invention to achieve the intended technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Furthermore, the technical means or technical features in the embodiments of the present invention can be replaced without creative effort. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0025] like Figure 1 As shown, a method for preparing a micro-wrinkled aluminum-sheathed cable according to the present invention includes the following steps: S1. Aluminum Strip Pretreatment: Aluminum strip pretreatment includes aluminum strip cleaning, aluminum strip straightening, and aluminum strip shearing. 1060-O aluminum strip is used. The tensile strength of this aluminum strip should not exceed 70 MPa, and its elongation should reach or exceed 25%.

[0026] Aluminum strip cleaning: Electrostatic dust removal is used to remove dust from the aluminum strip surface, and ultrasonic cleaning technology is used in conjunction with 70℃ isoacetone solution to remove oil stains from the aluminum strip surface. After treatment, the residual oil stains on the aluminum strip surface are controlled below 5mg / m².

[0027] Aluminum strip straightening: The aluminum strip is straightened by using multiple sets of guide rollers and a track straightening method to eliminate residual stress.

[0028] Aluminum strip shearing: The aluminum strip is cut to a preset width using a cutting tool. To prevent cracking of the rolled edges during subsequent processing, a special tool (such as a diamond cutter) is used to chamfer the edges of the aluminum strip. The chamfer size is C0.1×45°, which can effectively avoid edge cracking.

[0029] S2, Progressive micro-wrinkle embossing: such as Figure 2As shown, the initial rolling stage involves pre-forming grooves and controlling the deformation of the aluminum strip to 25%–40% of the final total deformation. The finishing rolling stage involves depth-fixed grooves, and the shaping stage involves flattening the sharp corners of the aluminum strip grooves. The initial rolling stage only produces grooves at the peaks and valleys of the final grooves.

[0030] Specifically, in the initial rolling stage, large-radius circular arc rolls are used for pre-forming grooves, and the deformation of the aluminum strip is controlled at 25% to 40% of the final total deformation.

[0031] In the finishing rolling stage, toothed involute rolls are used for fixed-depth texturing, resulting in a wrinkle depth h = (0.3~0.8)t, where t is the thickness of the aluminum strip. The tooth angle α of the toothed involute rolls is 75°±1°.

[0032] During the shaping stage, a polymer elastic roller is used to flatten the sharp corners of the aluminum strip's rolled grooves, smoothing out the peaks and valleys formed during the previous rolling process. The peaks and valleys of the rolled grooves are rounded with a radius R = 0.4–0.6 mm, resulting in a final rolled groove depth of 0.5–1.5 mm. The polymer elastic roller uses a polyurethane elastic roller, and the rolling pressure is 0.8–1.2 MPa.

[0033] S3. Tube Rolling and Laser Welding: Aluminum strips are rolled into tubes by a spiral tube rolling machine, and laser welding is carried out simultaneously under argon protection after rolling.

[0034] The spiral tube forming die of the tube rolling machine is designed to allow for adaptive adjustment of the curvature radius, with a wide adjustment range from Φ50 mm to Φ200 mm, to meet the production needs of aluminum tubes of different specifications.

[0035] Laser welding uses a laser with a power of 3kW or higher, a laser wavelength of 1070 nm, a laser welding speed of (15±5) m / min, and argon gas with a purity of up to 99.999% with a flow rate of (20±5) L / min. The penetration depth of laser welding is the aluminum strip thickness + 0.2 mm.

[0036] like Figure 3 As shown, a forming device for manufacturing micro-wrinkled aluminum-sheathed cables includes a wire feeding frame 1, a tape feeding machine 2, a straightening machine 3, a corrugating machine 4, a tube winding machine 5, a laser welding machine 6, and a take-up frame 7 arranged sequentially along the transmission direction of the micro-wrinkled aluminum-sheathed cable. The corrugating machine 4 includes a primary pre-rolling machine, a secondary finishing mill, and a tertiary constant-speed mill. The primary pre-rolling machine uses arc rollers, the secondary finishing mill uses toothed involute rollers with a tooth angle α = 75° ± 1°, and the tertiary constant-speed mill uses polymer elastic rollers. In this embodiment, the wire feeding frame 1, tape feeding machine 2, straightening machine 3, corrugating machine 4, tube winding machine 5, laser welding machine 6, and take-up frame 7 are all existing technologies, and their specific structures will not be described in detail. The corrugating machine 4 mainly improves the rollers.

[0037] A forming device for manufacturing micro-wrinkled aluminum-sheathed cables further includes a tension detection unit 8, a pressure sensor 9, a PLC 10, a weld seam tracking unit 11, a weld seam detection unit 12, and a control cloud platform 13. The tension detection unit 8 collects the tension of the aluminum strip released by the unloading machine 2 and ultimately controls the tension fluctuation of the straightening unit to ≤±1.5%. The pressure sensor 9 collects the pressure of the rollers of the corrugating machine 4 and uploads it to the PLC. The weld seam tracking unit 11 tracks the distance between the laser welding gun and the aluminum tube in real time. The weld seam detection unit 12 monitors the welding quality of the aluminum tube in real time. The tension detection unit 8, PLC 10, weld tracking unit 11, and weld seam detection unit 12 are connected to the control cloud platform 13 and upload the collected information to the control cloud platform 13 in real time.

[0038] The weld tracking unit 11 uses a laser rangefinder to monitor the distance between the welding torch and the aluminum sleeve in real time during the welding process. The weld inspection unit 12 uses a CCD vision inspection system to perform a detailed inspection of the weld quality.

[0039] This invention provides a method for preparing a micro-wrinkled aluminum sheath cable and its forming equipment. Shallow grooves with a depth of 0.5–1.5 mm are formed on the surface of the aluminum sheath (traditional wrinkle depth is 3.0–6.5 mm), combining the advantages of both smooth and wrinkled aluminum sheath cables. The micro-wrinkled aluminum sheath provides bending and compressive strength close to that of traditional wrinkled aluminum sheaths, avoiding the crease problem of smooth aluminum sheaths, while increasing the effective surface contact with the buffer layer, resulting in low current density and mitigating the risk of ablation. This invention employs a process of first corrugating the aluminum strip and then welding the coiled tube, solving the problem of surface pressure on the cross-linked core of existing wrinkled aluminum sheath cables. To address the issue of wrinkles, this invention employs a three-stage rolling process—initial rolling, finishing rolling, and shaping—to control the wrinkle depth fluctuation within ±5%. Simultaneously, it ensures that the radius R of the edge fillet is greater than or equal to 0.3mm, effectively preventing stress concentration and further enhancing product stability and reliability. Furthermore, the use of micro-wrinkle and peak-valley rounded corner processes increases the contact area between the corrugations and the cable core, preventing localized overheating and carbonization at the buffer layer. This invention reduces reliance on manual labor, and process parameters are dynamically collected and uploaded to the cloud for easy subsequent improvement and optimization.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a micro-wrinkled aluminum-sheathed cable, characterized in that... Includes the following steps: S1. Aluminum strip pretreatment; S2. Progressive micro-wrinkle rolling: Pre-forming rolling is carried out in the initial rolling stage and the deformation of the aluminum strip is controlled at 25% to 40% of the final total deformation. The depth rolling is carried out in the finishing rolling stage, and the sharp corners of the aluminum strip rolling are flattened in the shaping stage. S3, pipe rolling and laser welding.

2. The method for preparing a micro-wrinkled aluminum-sheathed cable according to claim 1, characterized in that: The specific steps of step S1 are: aluminum strip pretreatment includes aluminum strip cleaning, aluminum strip straightening and aluminum strip cutting; Aluminum strip cleaning: Electrostatic dust removal is used to remove dust from the surface of the aluminum strip, and ultrasonic cleaning technology combined with isoacetone solution is used to clean and remove oil stains from the surface of the aluminum strip; Aluminum strip straightening: The aluminum strip is straightened by using multiple sets of guide rollers and a track straightening method to eliminate residual stress; Aluminum strip cutting: Cut the aluminum strip to the preset width and chamfer the edges of the aluminum strip.

3. The method for preparing a micro-wrinkled aluminum-sheathed cable according to claim 2, characterized in that: The chamfer has a dimension of C0.1×45°.

4. The method for preparing a micro-wrinkled aluminum-sheathed cable according to claim 1, characterized in that: Step S2 specifically involves: In the initial rolling stage, large-radius circular arc rolls are used for pre-forming of the grooves, and the deformation of the aluminum strip is controlled within 25% to 40% of the final total deformation. In the finishing rolling stage, toothed involute rolls are used to perform fixed-depth texturing, so that the wrinkle depth h = (0.3~0.8)t, where t is the thickness of the aluminum strip; During the shaping stage, a polymer elastic roller is used to flatten the sharp corners of the aluminum strip's rolled grooves, so that the peaks and valleys of the rolled grooves form rounded corners with a radius of R = 0.4 to 0.6 mm, and the final rolled groove depth is 0.5 to 1.5 mm.

5. The method for preparing a micro-wrinkled aluminum-sheathed cable according to claim 4, characterized in that: The tooth angle α of the toothed involute roll is 75°±1°.

6. The method for preparing a micro-wrinkled aluminum-sheathed cable according to claim 4, characterized in that: The pressure of the polymer elastic roller is 0.8-1.2 MPa.

7. The method for preparing a micro-wrinkled aluminum-sheathed cable according to claim 1, characterized in that: Step S3 specifically involves: the aluminum strip being rolled into a tubular shape, and then simultaneously subjected to laser welding under argon protection.

8. The method for preparing a micro-wrinkled aluminum-sheathed cable according to claim 7, characterized in that: The laser welding uses a laser of 3kW or higher with a laser wavelength of 1070 nm, a laser welding speed of (15±5) m / min, an argon flow rate of (20±5) L / min, and a laser welding penetration depth of aluminum strip thickness + 0.2 mm.

9. A molding apparatus for implementing the method for preparing micro-wrinkled aluminum-sheathed cables according to any one of claims 1-8, characterized in that: The system includes a wire feeding frame, a tape feeding machine, a straightening machine, a corrugating machine, a tube winding machine, a laser welding machine, and a take-up frame arranged sequentially along the transmission direction of the micro-wrinkled aluminum sheathed cable. The corrugating machine includes a primary pre-rolling machine, a secondary finishing mill, and a tertiary fixed mill. The primary pre-rolling machine uses arc rolls, the secondary finishing mill uses toothed involute rolls with a tooth angle α = 75° ± 1°, and the tertiary fixed mill uses polymer elastic rolls.

10. The molding equipment according to claim 9, characterized in that: It also includes a tension detection unit, a pressure sensor, a PLC, a weld seam tracking unit, a weld seam detection unit, and a control cloud platform. The tension detection unit collects the tension of the aluminum strip released by the strip feeding machine, the pressure sensor collects the pressure of the rolling mill rolls and uploads it to the PLC, the weld seam tracking unit tracks the distance between the laser welding machine's welding torch and the aluminum tube in real time, the weld seam detection unit monitors the welding quality of the aluminum tube in real time, and the tension detection unit, PLC, weld seam tracking unit, and weld seam detection unit are connected to the control cloud platform and upload the collected information to the control cloud platform in real time.

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