A manufacturing process for industrial robot control cables operating under high-frequency bending conditions

Abstract

This invention discloses a manufacturing process for an industrial robot control cable under high-frequency bending conditions, comprising the following steps: S1, preparation of ultra-fine flexible conductor; S2, double-layer flexible insulation coating; S3, core bundling and buffer stranding; S4, multi-layer damping shielding coating; S5, three-stage gradient sheath extrusion; S6, low-temperature stress elimination; S7, finished product finishing and inspection. The conductor of this invention exhibits excellent fatigue resistance. The nitrogen-protected low-temperature annealing process, combined with a layered, uneven-pitch stranding structure, effectively optimizes the internal stress distribution of the conductor, enhancing its overall flexibility and deformation tolerance. This fundamentally reduces the risk of single-wire breakage under high-frequency bending conditions, significantly improving the conductor's fatigue life. The double-layer differentiated insulation structure, combined with a gradient cooling and shaping process, possesses both flexible deformation adaptability and wear-resistant and anti-aging properties, enabling long-term adaptation to repeated high-frequency deformation and effectively preventing insulation layer cracking, delamination, and aging failure, ensuring long-term stable cable insulation performance.

Description

Technical Field

[0001] This invention belongs to the field of automated equipment cable processing technology, specifically a manufacturing process for industrial robot control cables under high-frequency bending conditions. Background Technology

[0002] Industrial robots are the core execution equipment in intelligent manufacturing and flexible automated production lines, and are widely used in automobile manufacturing, precision electronic assembly, logistics sorting, and machining. During operation, the robotic arm and joints of industrial robots continuously perform high-frequency reciprocating swinging, bending, and twisting. The supporting control cables are subjected to complex conditions such as high-frequency fatigue deformation, internal friction and extrusion, and alternating environmental temperature changes for a long time, which places extremely high demands on the structural stability, bending fatigue resistance, wear resistance, and insulation stability of the cables.

[0003] Existing traditional robot control cable manufacturing processes have several technical shortcomings: Traditional processes often use ordinary copper wires stranded in a single-pitch configuration without sufficient softening treatment, resulting in significant stress concentration within the conductor. Long-term high-frequency bending can easily lead to single-wire breakage, causing signal interruption. The insulation structure is mostly a single layer of ordinary polymer material, with poor flexibility, weak crack resistance and aging resistance. Long-term repeated deformation can easily lead to insulation embrittlement and failure. The cable core bundle structure lacks a buffer filling structure, resulting in continuous friction and compression between cores and between the cores and the shielding layer, easily causing internal structural wear and damage. The shielding layer often uses a single braided structure, which has high rigidity and poor deformation adaptability, easily loosening and deforming after bending, leading to a decrease in electromagnetic shielding effectiveness. Furthermore, traditional manufacturing processes lack a dedicated stress relief process, leaving residual stress generated during cable stranding and extrusion molding. This can easily lead to problems such as sheath deformation, delamination, and detachment, significantly shortening the cable's service life.

[0004] Robot cables manufactured using existing conventional processes have a limited number of bending fatigue cycles, which cannot meet the requirements of high-end industrial robots for long-term, high-frequency continuous operation at tens of millions of cycles. This results in high equipment failure rates and high maintenance costs, severely restricting the stable operation of automated production lines. Based on these shortcomings of existing technologies, there is an urgent need to develop a manufacturing process for high-frequency bending-specific industrial robot control cables that offers strong structural adaptability, excellent fatigue resistance, and high structural stability.

[0005] Based on this, a manufacturing process for industrial robot control cables under high-frequency bending conditions is designed. Summary of the Invention

[0006] In view of the above situation and to overcome the defects of the prior art, the present invention provides a manufacturing process for industrial robot control cables under high-frequency bending conditions, which effectively solves the problems mentioned in the background.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a manufacturing process for an industrial robot control cable under high-frequency bending conditions, comprising the following steps:

[0008] S1. Preparation of ultra-fine flexible conductor: Select oxygen-free tin-plated copper monofilaments with a diameter of 0.08-0.12 mm, and perform low-temperature softening annealing treatment under a nitrogen inert protective atmosphere. The annealing temperature is 180-210℃, and the holding time is 25-35 min. Then, allow it to cool naturally to room temperature. Bundle the softened copper monofilaments into bundles of 18-22 strands and prepare conductor cores using a layered, same-direction, different-pitch stranding process. The inner layer stranding pitch is 8-12 mm, and the outer layer stranding pitch is 15-18 mm. The stranding tension is constant at 8-12 N. After stranding, straighten, deburr, and polish the conductor cores.

[0009] S2. Double-layer flexible insulation coating: Modified elastic polyolefin insulation material is used to perform double-layer synchronous continuous extrusion coating on the conductor core wire; the inner layer is a buffer insulation layer with a thickness of 0.15-0.20mm, an extrusion temperature of 165-175℃, and an extrusion speed of 40-45m / min; the outer layer is a wear-resistant insulation layer with a thickness of 0.25-0.30mm, an extrusion temperature of 180-190℃, and an extrusion speed of 35-40m / min; after coating, segmented gradient cooling from 55℃ to 25℃ is used, with a total cooling time of 15-20min;

[0010] S3. Core Bundling and Buffer Stranding: The double-insulated cores are arranged in a 3×2, 4×2 or 6×2 pattern, and semi-circular modified silicone rubber buffer strips with a thickness of 0.3-0.5mm are filled between adjacent cores; a low-tension reverse integral stranding process is adopted, with a stranding pitch of 45-55mm, a stranding tension of 15-20N, and a stranding direction opposite to the stranding direction of the outer layer of the conductor, to obtain a composite core bundle;

[0011] S4. Multi-layer damping shielding: A flexible buffer transition layer, a braided shielding layer, and a wrapping isolation layer are sequentially wrapped around the outside of the composite core bundle from the inside out. The flexible buffer transition layer is made of polyester elastic tape with a wrapping overlap rate of 25%-30% and a thickness of 0.20-0.25mm. The braided shielding layer is made of 0.10mm tin-plated copper wire with a braiding density of 92%-95% and a braiding angle of 38°-42°. The wrapping isolation layer is made of polyimide film with a unidirectional wrapping overlap rate of 18%-22%.

[0012] S5. Three-stage gradient sheath extrusion: The outer sheath is formed by three-stage gradient temperature-controlled extrusion using bend-resistant and flame-retardant TPU elastic material; the first stage temperature is 170-180℃, the second stage temperature is 185-195℃, and the third stage temperature is 175-185℃. The total thickness of the sheath is 1.2-1.5mm, and the extrusion speed is 28-32m / min. After extrusion, it is cooled to room temperature by a uniform water mist at a rate of 2-3℃ / s to set the shape.

[0013] S6. Low-temperature aging stress elimination: Place the semi-finished cable in a constant temperature and dust-free aging chamber and keep it at a constant temperature of 45-55℃ and humidity of 40%-50% for 4-6 hours; then cool it down to room temperature at a uniform rate of 1-1.5℃ / min to eliminate residual processing stress.

[0014] S7. Finished Product Finishing and Inspection: After the cable has been shaped, surface finishing, dust removal, defect removal and length cutting are carried out to complete the finished product preparation.

[0015] Preferably, in step S1, the nitrogen flow rate is 0.8-1.2 m³ / h.

[0016] Preferably, in step S2, the modified elastic polyolefin insulation material comprises, by weight: 45-50 parts of low-density polyethylene, 30-35 parts of ethylene-vinyl acetate copolymer, 8-12 parts of elastic toughening agent, 1.5-2.5 parts of antioxidant, and 2-3 parts of wear-resistant filler; the modified elastic polyolefin insulation material has a Shore hardness of 75-80 HA.

[0017] Preferably, in step S3, the modified silicone rubber buffer strip has a Shore hardness of 40-45HA and a compression resilience of ≥95%.

[0018] Preferably, in step S4, the elongation at break of the polyester elastic band is ≥300%, and the thickness of the polyimide film is 0.08-0.10 mm.

[0019] Preferably, in step S5, the Shore hardness of the TPU sheath material is 88-92HA.

[0020] Preferably, in step S6, the interior of the aging chamber is a windless, dust-free, and sealed working environment.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. The conductor of this invention has excellent fatigue resistance. It adopts a nitrogen-protected low-temperature annealing process combined with a layered uneven pitch stranding structure, which effectively optimizes the internal stress distribution of the conductor, improves the overall flexibility and deformation resistance of the conductor, reduces the risk of single wire breakage under high-frequency bending conditions from the root, and significantly improves the fatigue life of the conductor.

[0023] 2. The insulation system of this invention is stable and reliable. The double-layer differentiated insulation structure combined with the gradient cooling and shaping process has both flexible deformation adaptability and wear-resistant and anti-aging properties. It can adapt to high-frequency repeated deformation for a long time, effectively prevent the insulation layer from cracking, delamination and aging failure, and ensure the long-term stability of cable insulation performance.

[0024] 3. The internal structure of this invention has strong stability. The high-resilience buffer structure between the wire cores and the reverse low-tension stranding structure work together to adapt to complex deformations such as high-frequency bending, torsion, and extrusion, eliminate hard friction loss between the wire cores, and ensure that the internal structure of the cable is compact and stable for a long time without loosening or wear.

[0025] 4. The shielding performance of this invention is durable and stable. The three-layer composite damping shielding structure replaces the traditional single shielding structure, which greatly improves the shielding layer's resistance to deformation and loosening. It can still maintain excellent electromagnetic shielding effect under long-term high-frequency bending conditions, effectively resist electromagnetic interference in industrial sites, and ensure stable transmission of control signals.

[0026] 5. The invention completely eliminates residual stress. The three-stage gradient temperature-controlled extrusion molding ensures that the sheath material is dense and uniform. Combined with the low-temperature constant-temperature aging and shaping process, the extrusion stress and deformation stress during the processing are completely eliminated, avoiding quality defects such as cable deformation, delamination, and detachment in the later stage, and greatly extending the overall service life of the cable. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] This invention provides a manufacturing process for industrial robot control cables operating under high-frequency bending conditions, comprising the following steps:

[0029] S1. Preparation of ultra-fine flexible conductor: Select oxygen-free tin-plated copper monofilaments with a diameter of 0.08-0.12 mm, and perform low-temperature softening annealing treatment under a nitrogen inert protective atmosphere. The annealing temperature is 180-210℃, and the holding time is 25-35 min. Then, allow it to cool naturally to room temperature. Bundle the softened copper monofilaments into bundles of 18-22 strands and prepare conductor cores using a layered, same-direction, different-pitch stranding process. The inner layer stranding pitch is 8-12 mm, and the outer layer stranding pitch is 15-18 mm. The stranding tension is constant at 8-12 N. After stranding, straighten, deburr, and polish the conductor cores.

[0030] S2. Double-layer flexible insulation coating: Modified elastic polyolefin insulation material is used to perform double-layer synchronous continuous extrusion coating on the conductor core wire; the inner layer is a buffer insulation layer with a thickness of 0.15-0.20mm, an extrusion temperature of 165-175℃, and an extrusion speed of 40-45m / min; the outer layer is a wear-resistant insulation layer with a thickness of 0.25-0.30mm, an extrusion temperature of 180-190℃, and an extrusion speed of 35-40m / min; after coating, segmented gradient cooling from 55℃ to 25℃ is used, with a total cooling time of 15-20min;

[0031] S3. Core Bundling and Buffer Stranding: The double-insulated cores are arranged in a 3×2, 4×2 or 6×2 pattern, and semi-circular modified silicone rubber buffer strips with a thickness of 0.3-0.5mm are filled between adjacent cores; a low-tension reverse integral stranding process is adopted, with a stranding pitch of 45-55mm, a stranding tension of 15-20N, and a stranding direction opposite to the stranding direction of the outer layer of the conductor, to obtain a composite core bundle;

[0032] S4. Multi-layer damping shielding: A flexible buffer transition layer, a braided shielding layer, and a wrapping isolation layer are sequentially wrapped around the outside of the composite core bundle from the inside out. The flexible buffer transition layer is made of polyester elastic tape with a wrapping overlap rate of 25%-30% and a thickness of 0.20-0.25mm. The braided shielding layer is made of 0.10mm tin-plated copper wire with a braiding density of 92%-95% and a braiding angle of 38°-42°. The wrapping isolation layer is made of polyimide film with a unidirectional wrapping overlap rate of 18%-22%.

[0033] S5. Three-stage gradient sheath extrusion: The outer sheath is formed by three-stage gradient temperature-controlled extrusion using bend-resistant and flame-retardant TPU elastic material; the first stage temperature is 170-180℃, the second stage temperature is 185-195℃, and the third stage temperature is 175-185℃. The total thickness of the sheath is 1.2-1.5mm, and the extrusion speed is 28-32m / min. After extrusion, it is cooled to room temperature by a uniform water mist at a rate of 2-3℃ / s to set the shape.

[0034] S6. Low-temperature aging stress elimination: Place the semi-finished cable in a constant temperature and dust-free aging chamber and keep it at a constant temperature of 45-55℃ and humidity of 40%-50% for 4-6 hours; then cool it down to room temperature at a uniform rate of 1-1.5℃ / min to eliminate residual processing stress.

[0035] S7. Finished Product Finishing and Inspection: After the cable has been shaped, surface finishing, dust removal, defect removal and length cutting are carried out to complete the finished product preparation.

[0036] In step S1 of this embodiment, the nitrogen flow rate is 0.8-1.2 m³ / h.

[0037] In step S2 of this embodiment, the modified elastic polyolefin insulation material comprises, by weight: 45-50 parts of low-density polyethylene, 30-35 parts of ethylene-vinyl acetate copolymer, 8-12 parts of elastic toughening agent, 1.5-2.5 parts of antioxidant, and 2-3 parts of wear-resistant filler; the Shore hardness of the modified elastic polyolefin insulation material is 75-80HA.

[0038] In step S3 of this embodiment, the modified silicone rubber buffer strip has a Shore hardness of 40-45HA and a compression rebound rate of ≥95%.

[0039] In step S4 of this embodiment, the elongation at break of the polyester elastic band is ≥300%, and the thickness of the polyimide film is 0.08-0.10 mm.

[0040] In step S5 of this embodiment, the Shore hardness of the TPU sheath material is 88-92HA.

[0041] In step S6 of this embodiment, the interior of the aging chamber is a windless, dust-free, and sealed working environment.

[0042] Example 1:

[0043] A manufacturing process for an industrial robot control cable operating under high-frequency bending conditions includes the following steps:

[0044] S1. Preparation of ultra-fine flexible conductor: Select oxygen-free tin-plated copper monofilaments with a diameter of 0.10 mm. Place the copper monofilaments in a nitrogen protective atmosphere with a flow rate of 1.0 m³ / h and perform low-temperature softening annealing treatment at 200℃. After holding at a constant temperature for 30 min, allow them to cool naturally to room temperature in the furnace. Select 20 strands of softened copper monofilaments as a bundle and use a layered, same-direction, different-pitch stranding process to prepare the conductor core wire. The inner layer stranding pitch is 10 mm, and the outer layer stranding pitch is 16 mm. The stranding tension is constant at 10 N throughout the process. After stranding, the conductor core wire is straightened, deburred, and polished to ensure that the conductor surface is flat and the structure is regular.

[0045] S2. Double-layer flexible insulation coating: Modified elastic polyolefin insulation material is used. The raw materials are formulated by weight as follows: 48 parts low-density polyethylene, 32 parts ethylene-vinyl acetate copolymer, 10 parts elastic toughening agent, 2 parts antioxidant, and 2.5 parts wear-resistant filler. The material has a Shore hardness of 78HA. The raw materials are mixed, granulated, and dried before use. The conductor core is coated using a double-layer synchronous continuous extrusion method. The inner buffer insulation layer is 0.18mm thick, the extrusion temperature is 170℃, and the extrusion speed is 42m / min. The outer wear-resistant insulation layer is 0.28mm thick, the extrusion temperature is 185℃, and the extrusion speed is 38m / min. After coating, a segmented gradient cooling method is used. The cooling water temperature is gradually and steadily reduced from 55℃ to 25℃, with a total cooling time of 18min.

[0046] S3. Core Bundling and Buffer Stranding: The double-insulated cores are arranged in a 4×2 configuration to ensure uniform and untwisted arrangement. A semi-circular modified silicone rubber buffer strip with a thickness of 0.4mm and a Shore hardness of 42HA is filled between adjacent cores. The buffer strip has a compression resilience of ≥95%. After filling, a reverse low-tension integral stranding process is used with a stranding pitch of 50mm, a stranding tension of 18N, and a stranding direction opposite to that of the outer conductor layer, resulting in a compact composite core bundle.

[0047] S4. Multi-layer damping shielding: Polyester elastic tape is wrapped around the outside of the composite core bundle as a flexible buffer transition layer with a wrapping overlap rate of 28% and a forming thickness of 0.22mm; 0.10mm tin-plated copper wire is used for precision braiding shielding on the outside of the buffer transition layer with a braiding density of 93% and a braiding angle of 40°; finally, a 0.09mm polyimide film isolation layer is wrapped unidirectionally on the outside of the braided shielding layer with a wrapping overlap rate of 20%, completing the preparation of the composite shielding structure;

[0048] S5. Three-stage gradient sheath extrusion: The outer sheath is formed using a three-stage gradient temperature-controlled extrusion process with a Shore hardness of 90HA, resistant to bending and flame retardant TPU elastic material. The first stage extrusion temperature is 175℃, the second stage extrusion temperature is 190℃, and the third stage extrusion temperature is 180℃. The total thickness of the sheath is 1.3mm, and the extrusion speed is 30m / min. After extrusion, the sheath is cooled by water mist at a constant cooling rate of 2.5℃ / s until it is set at room temperature.

[0049] S6. Low-temperature aging stress elimination: After cooling and shaping, the semi-finished cable is transferred into a dust-free constant temperature aging chamber. The humidity inside the chamber is controlled at 45%. The chamber is kept in a windless, dust-free, and sealed environment and kept at a constant temperature of 50℃ for 5 hours. After the settling is completed, the cable is slowly cooled to room temperature at a uniform cooling rate of 1.2℃ / min to eliminate residual stress from the internal processing of the cable.

[0050] S7. Finished Product Finishing and Inspection: The shaped cable is polished, dusted, and imperfections are repaired. Surface burrs and protrusions are removed. The cable is then cut to the specified length according to standard dimensions to complete the finished product preparation.

[0051] Example 2:

[0052] A manufacturing process for an industrial robot control cable operating under high-frequency bending conditions includes the following steps:

[0053] S1. Preparation of ultra-fine flexible conductor: Select oxygen-free tin-plated copper monofilaments with a diameter of 0.08 mm. Place the copper monofilaments in a nitrogen protective atmosphere with a flow rate of 0.8 m³ / h and perform low-temperature softening annealing treatment at 180℃. After holding at a constant temperature for 35 min, allow them to cool naturally to room temperature in the furnace. Select 18 strands of softened copper monofilaments as a bundle and use a layered, same-direction, different-pitch stranding process to prepare the conductor core wire. The inner layer stranding pitch is 8 mm, and the outer layer stranding pitch is 15 mm. The stranding tension is constant at 8 N throughout the process. After stranding, the conductor core wire is straightened, deburred, and polished to ensure that the conductor surface is flat and the structure is regular.

[0054] S2. Double-layer flexible insulation coating: Modified elastic polyolefin insulation material is used. The raw materials are formulated by weight as follows: 45 parts low-density polyethylene, 35 parts ethylene-vinyl acetate copolymer, 12 parts elastic toughening agent, 1.5 parts antioxidant, and 2 parts wear-resistant filler. The material has a Shore hardness of 75HA. The raw materials are mixed, granulated, and dried before use. The conductor core is coated using a double-layer synchronous continuous extrusion method. The inner buffer insulation layer is 0.15mm thick, the extrusion temperature is 165℃, and the extrusion speed is 40m / min. The outer wear-resistant insulation layer is 0.25mm thick, the extrusion temperature is 180℃, and the extrusion speed is 35m / min. After coating, a segmented gradient cooling method is used. The cooling water temperature is gradually and steadily reduced from 55℃ to 25℃, with a total cooling time of 20min.

[0055] S3. Core Bundling and Buffer Stranding: The double-insulated cores are arranged in a 4×2 combination to ensure uniform and untwisted arrangement. A semi-circular modified silicone rubber buffer strip with a thickness of 0.3mm and a Shore hardness of 40HA is filled between adjacent cores. The buffer strip has a compression rebound rate of ≥95%. After filling, a reverse low-tension integral stranding process is used with a stranding pitch of 45mm, a stranding tension of 15N, and a stranding direction opposite to the stranding direction of the outer conductor layer to obtain a highly flexible composite core bundle.

[0056] S4. Multi-layer damping shielding: Polyester elastic tape is wrapped around the outside of the composite core bundle as a flexible buffer transition layer with a wrapping overlap rate of 25% and a forming thickness of 0.20mm; 0.10mm tin-plated copper wire is used for precision braiding shielding on the outside of the buffer transition layer with a braiding density of 92% and a braiding angle of 38°; finally, a 0.08mm polyimide film isolation layer is wrapped unidirectionally on the outside of the braided shielding layer with a wrapping overlap rate of 18%, completing the preparation of the composite shielding structure;

[0057] S5. Three-stage gradient sheath extrusion: Using flexurally resistant and flame-retardant TPU elastic material with a Shore hardness of 88HA, the outer sheath is formed using a three-stage gradient temperature-controlled extrusion process. The first stage extrusion temperature is 170℃, the second stage is 185℃, and the third stage is 175℃. The total sheath thickness is 1.2mm, and the extrusion speed is 28m / min. After extrusion, the sheath is uniformly cooled with water mist at a constant cooling rate of 2℃ / s until it reaches room temperature for setting.

[0058] S6. Low-temperature aging stress elimination: After cooling and shaping, the cable semi-finished product is transferred into a dust-free constant temperature aging chamber. The humidity inside the chamber is controlled at 40%, and a windless, dust-free, and sealed environment is maintained. The cable is kept at a constant temperature of 45℃ for 6 hours. After the static period, the cable is slowly cooled to room temperature at a uniform cooling rate of 1℃ / min to eliminate residual stress from the internal processing of the cable.

[0059] S7. Finished Product Finishing and Inspection: The shaped cable is polished, dusted, and imperfections are repaired. Surface burrs and protrusions are removed. The cable is then cut to the specified length according to standard dimensions to complete the finished product preparation.

[0060] Example 3:

[0061] A manufacturing process for an industrial robot control cable operating under high-frequency bending conditions includes the following steps:

[0062] S1. Preparation of ultra-fine flexible conductor: Select oxygen-free tin-plated copper monofilaments with a diameter of 0.12 mm. Place the copper monofilaments in a nitrogen protective atmosphere with a flow rate of 1.2 m³ / h and perform low-temperature softening annealing treatment at 210℃. After holding at a constant temperature for 25 min, allow them to cool naturally to room temperature in the furnace. Select 22 strands of softened copper monofilaments as a bundle and use a layered, same-direction, different-pitch stranding process to prepare the conductor core wire. The inner layer stranding pitch is 12 mm, and the outer layer stranding pitch is 18 mm. The stranding tension is constant at 12 N throughout the process. After stranding, the conductor core wire is straightened, deburred, and polished to ensure that the conductor surface is flat and the structure is regular.

[0063] S2. Double-layer flexible insulation coating: Modified elastic polyolefin insulation material is used. The raw materials are formulated by weight as follows: 50 parts low-density polyethylene, 30 parts ethylene-vinyl acetate copolymer, 8 parts elastic toughening agent, 2.5 parts antioxidant, and 3 parts wear-resistant filler. The material has a Shore hardness of 80HA. The raw materials are mixed, granulated, and dried before use. The conductor core is coated using a double-layer synchronous continuous extrusion method. The inner buffer insulation layer is 0.20mm thick, the extrusion temperature is 175℃, and the extrusion speed is 45m / min. The outer wear-resistant insulation layer is 0.30mm thick, the extrusion temperature is 190℃, and the extrusion speed is 40m / min. After coating, a segmented gradient cooling method is used. The cooling water temperature is gradually and steadily reduced from 55℃ to 25℃, with a total cooling time of 15min.

[0064] S3. Core Bundling and Buffer Stranding: The double-insulated cores are arranged in a 4×2 combination to ensure uniform and untwisted arrangement. A semi-circular modified silicone rubber buffer strip with a thickness of 0.5mm and a Shore hardness of 45HA is filled between adjacent cores. The buffer strip has a compression rebound rate of ≥95%. After filling, a reverse low-tension integral stranding process is used with a stranding pitch of 55mm, a stranding tension of 20N, and a stranding direction opposite to the stranding direction of the outer conductor layer to obtain a high-strength composite core bundle.

[0065] S4. Multi-layer damping shielding: Polyester elastic tape is wrapped around the outside of the composite core bundle as a flexible buffer transition layer with a wrapping overlap rate of 30% and a forming thickness of 0.25mm; 0.10mm tin-plated copper wire is used for precision braiding shielding on the outside of the buffer transition layer with a braiding density of 95% and a braiding angle of 42°; finally, a 0.10mm polyimide film isolation layer is wrapped unidirectionally on the outside of the braided shielding layer with a wrapping overlap rate of 22%, completing the preparation of the composite shielding structure;

[0066] S5. Three-stage gradient sheath extrusion: The outer sheath is formed using a three-stage gradient temperature-controlled extrusion process with a Shore hardness of 92HA, which is resistant to bending and flame retardant. The first stage extrusion temperature is 180℃, the second stage extrusion temperature is 195℃, and the third stage extrusion temperature is 185℃. The total thickness of the sheath is 1.5mm, and the extrusion speed is 32m / min. After extrusion, the sheath is cooled by water mist at a constant cooling rate of 3℃ / s until it is set at room temperature.

[0067] S6. Low-temperature aging stress elimination: After cooling and shaping, the cable semi-finished product is transferred into a dust-free constant temperature aging chamber. The humidity inside the chamber is controlled at 50%, and a windless, dust-free, and sealed environment is maintained. The cable is kept at a constant temperature of 55℃ for 4 hours. After the settling is completed, the cable is slowly cooled to room temperature at a uniform cooling rate of 1.5℃ / min to eliminate residual stress from the internal processing of the cable.

[0068] S7. Finished Product Finishing and Inspection: The shaped cable is polished, dusted, and imperfections are repaired. Surface burrs and protrusions are removed. The cable is then cut to the specified length according to standard dimensions to complete the finished product preparation.

[0069] Scale settings instructions

[0070] To objectively verify the technical advantages of the process of this invention, a conventional robot control cable manufacturing process in the industry is set as a comparative example.

[0071] The comparative examples and the three sets of sample examples of this invention use the same cable specifications and dimensions, differing only in the manufacturing process. The specific process is as follows: 0.10mm conventional tin-plated copper wire is used in single-stage equal-pitch stranding without inert gas low-temperature annealing; a single-layer ordinary polyolefin insulation extrusion structure is used without a double-layer buffer insulation system; flexible buffer filler strips are not used during the core bundling process; a single copper wire braided shielding structure is used without a buffer transition layer or insulation isolation layer; a single constant-temperature extrusion molding sheath is used without a three-stage gradient temperature-controlled molding process; and there is no low-temperature constant-temperature stress relief process after molding. Parallel comparative tests were conducted on the comparative examples and the sample examples under the same national standard testing environment, testing equipment, and testing conditions.

[0072] Performance Test Results and Analysis

[0073] All performance tests were conducted on the proportional sample, Example 1 sample, Example 2 sample, and Example 3 sample under the same environmental conditions, in accordance with national standard testing criteria, as shown in the table below:

[0074] Testing items National Standard for Conformity Traditional process comparison Example 1 Example 2 Example 3 Maximum number of high-frequency bends (±90°, 60 times / min) ≥3 million times 4.8 million times 10 million times 11 million times 10.5 million times Normal insulation resistance (MΩ·km) ≥500 680 1200 1280 1230 Electromagnetic shielding effectiveness (dB) ≥60 72 85 87 86 Wear resistance loss (mg / 1000 rpm) ≤50 42 30 32 28 -40℃ Low temperature bending performance No cracking, no embrittlement Slightly brittle No cracking, no embrittlement No cracking, no embrittlement No cracking, no embrittlement Conductor elongation at break (%) ≥25 26 30 29 28.5 Finished product pass rate (%) ≥95 92 99.2 99.0 99.1

[0075] As can be seen from the test data in the table above, the cables prepared by the three sets of embodiments of the present invention are significantly better than the comparative products of the traditional process in terms of high-frequency bending fatigue life, insulation performance, electromagnetic shielding performance, wear resistance, low-temperature toughness and finished product qualification rate.

[0076] This invention completely solves the technical problems of traditional robot cables, such as easy failure due to high-frequency bending, poor structural stability, and weak overall performance, through multi-dimensional synergistic improvements such as conductor structure optimization, double-layer insulation protection, internal buffer structure, composite shielding system, gradient molding, and stress aging elimination. The product is fully compatible with the high-frequency continuous operation conditions of high-end industrial robots, which require tens of millions of cycles.

[0077] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0078] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manufacturing process for an industrial robot control cable operating under high-frequency bending conditions, characterized in that, Includes the following steps: S1. Preparation of ultra-fine flexible conductor: Select oxygen-free tin-plated copper monofilaments with a diameter of 0.08-0.12 mm, and perform low-temperature softening annealing treatment under a nitrogen inert protective atmosphere. The annealing temperature is 180-210℃, and the holding time is 25-35 min. Then, allow it to cool naturally to room temperature. Bundle the softened copper monofilaments into bundles of 18-22 strands and prepare conductor cores using a layered, same-direction, different-pitch stranding process. The inner layer stranding pitch is 8-12 mm, and the outer layer stranding pitch is 15-18 mm. The stranding tension is constant at 8-12 N. After stranding, straighten, deburr, and polish the conductor cores. S2. Double-layer flexible insulation coating: Modified elastic polyolefin insulation material is used to perform double-layer synchronous continuous extrusion coating on the conductor core wire; the inner layer is a buffer insulation layer with a thickness of 0.15-0.20mm, an extrusion temperature of 165-175℃, and an extrusion speed of 40-45m / min; the outer layer is a wear-resistant insulation layer with a thickness of 0.25-0.30mm, an extrusion temperature of 180-190℃, and an extrusion speed of 35-40m / min; after coating, segmented gradient cooling from 55℃ to 25℃ is used, with a total cooling time of 15-20min; S3. Core Bundling and Buffer Stranding: The double-insulated cores are arranged in a 3×2, 4×2 or 6×2 pattern, and semi-circular modified silicone rubber buffer strips with a thickness of 0.3-0.5mm are filled between adjacent cores; a low-tension reverse integral stranding process is adopted, with a stranding pitch of 45-55mm, a stranding tension of 15-20N, and a stranding direction opposite to the stranding direction of the outer layer of the conductor, to obtain a composite core bundle; S4. Multi-layer damping shielding: A flexible buffer transition layer, a braided shielding layer, and a wrapping isolation layer are sequentially wrapped around the outside of the composite core bundle from the inside out. The flexible buffer transition layer is made of polyester elastic tape with a wrapping overlap rate of 25%-30% and a thickness of 0.20-0.25mm. The braided shielding layer is made of 0.10mm tin-plated copper wire with a braiding density of 92%-95% and a braiding angle of 38°-42°. The wrapping isolation layer is made of polyimide film with a unidirectional wrapping overlap rate of 18%-22%. S5. Three-stage gradient sheath extrusion: The outer sheath is formed by three-stage gradient temperature-controlled extrusion using bend-resistant and flame-retardant TPU elastic material; the first stage temperature is 170-180℃, the second stage temperature is 185-195℃, and the third stage temperature is 175-185℃. The total thickness of the sheath is 1.2-1.5mm, and the extrusion speed is 28-32m / min. After extrusion, it is cooled to room temperature by a uniform water mist at a rate of 2-3℃ / s to set the shape. S6. Low-temperature aging stress elimination: Place the semi-finished cable in a constant temperature and dust-free aging chamber and keep it at a constant temperature of 45-55℃ and humidity of 40%-50% for 4-6 hours; then cool it down to room temperature at a uniform rate of 1-1.5℃ / min to eliminate residual processing stress. S7. Finished Product Finishing and Inspection: After the cable has been shaped, surface finishing, dust removal, defect removal and length cutting are carried out to complete the finished product preparation.

2. The manufacturing process of an industrial robot control cable under high-frequency bending conditions according to claim 1, characterized in that, In step S1, the nitrogen flow rate is 0.8-1.2 m³ / h.

3. The manufacturing process of an industrial robot control cable under high-frequency bending conditions according to claim 1, characterized in that, In step S2, the modified elastic polyolefin insulation material comprises, by weight: 45-50 parts of low-density polyethylene, 30-35 parts of ethylene-vinyl acetate copolymer, 8-12 parts of elastic toughening agent, 1.5-2.5 parts of antioxidant, and 2-3 parts of wear-resistant filler; the Shore hardness of the modified elastic polyolefin insulation material is 75-80HA.

4. The manufacturing process of an industrial robot control cable under high-frequency bending conditions according to claim 1, characterized in that, In step S3, the modified silicone rubber buffer strip has a Shore hardness of 40-45HA and a compression resilience of ≥95%.

5. The manufacturing process of an industrial robot control cable under high-frequency bending conditions according to claim 1, characterized in that, In step S4, the elongation at break of the polyester elastic band is ≥300%, and the thickness of the polyimide film is 0.08-0.10 mm.

6. The manufacturing process of an industrial robot control cable under high-frequency bending conditions according to claim 1, characterized in that, In step S5, the Shore hardness of the TPU sheath material is 88-92HA.

7. The manufacturing process of an industrial robot control cable under high-frequency bending conditions according to claim 1, characterized in that, In step S6, the interior of the aging chamber is a windless, dust-free, and sealed working environment.