A flexible cable for industrial robots and its manufacturing method

Abstract

This invention discloses a flexible cable for industrial robots and its manufacturing method. The flexible cable for industrial robots includes a conductor composed of multiple stranded tinned copper wires, an insulation layer covering the conductor core, at least two cores stranded into a cable core, and a filler at the cable's axis. The cable core is further surrounded from the inside out by an inner sheath, a protective layer, a shielding layer, and an outer sheath. The outer sheath comprises the following components: polyether-based filler, modified reinforcing filler, flame retardant, plasticizer, antioxidant, lubricant, and light stabilizer. Through synergistic optimization of the cable's physical structure and the outer sheath's chemical formulation, the cable exhibits significant enhancements in wear resistance, oil resistance, flexibility, and long-term reliability, ultimately meeting the requirements of industrial robots operating in high-frequency, wide-range movements and complex, harsh industrial environments.

Description

Technical Field

[0001] This invention belongs to the field of cable technology, specifically relating to a flexible cable for industrial robots and its preparation method. Background Technology

[0002] Industrial robots were first applied in the automotive manufacturing industry, commonly used for welding, painting, material loading and unloading, and handling. Industrial robots extend and expand the functions of human hands, feet, and brain, allowing them to replace humans in hazardous, harmful, toxic, low-temperature, and high-heat environments; they can perform heavy, monotonous, and repetitive tasks, improving labor productivity and ensuring product quality. Industrial robots, along with CNC machining centers, automated guided vehicles (AGVs), and automatic inspection systems, can form flexible manufacturing systems and computer-integrated manufacturing systems, achieving production automation.

[0003] For robots, their movements rely on electricity and control signals. Electricity signals are delivered via power cables, and signal transmission is achieved through signal cables. Robot cables are therefore crucial. Flexible cables, acting as the "nervous system" and "vascular system" connecting the robot controller and actuators, are responsible for stably transmitting power and control signals during the robot's high-speed, high-frequency, large-angle torsional and bending movements. Therefore, cables used in this field must not only possess excellent electrical transmission performance and signal integrity, but also extremely high mechanical flexibility, resistance to bending fatigue, and tolerance to complex industrial environments.

[0004] Currently, PVC is a commonly used material in robot cables. While PVC has good abrasion resistance and insulation, it has low thermal stability and low flexibility, resulting in poor long-term fatigue resistance under high or low temperature conditions. To cope with harsh operating environments, existing technologies typically modify the outer sheath material to improve its overall performance. For example, plasticizers are added to the matrix such as thermoplastic polyurethane (TPU) to improve flexibility, inorganic fillers (such as talc and calcium carbonate) are added to enhance its mechanical strength and abrasion resistance, or specific additives (such as fluorinated compounds) are added to improve its chemical and oil resistance. However, these traditional modification methods have some technical drawbacks: First, simple physical blending often leads to poor interfacial compatibility between the filler and the matrix resin, which can easily generate stress concentration points under external force, thus reducing the fatigue resistance of the material, as shown in Chinese patent applications CN120199544A and CN109273159A; Second, it is difficult for additives with different properties to work synergistically. For example, excessive pursuit of wear resistance may sacrifice the flexibility of the material, while simply adding oleophobic additives also has the problems of easy migration and unsustainable performance, making it difficult to obtain a flexible cable for industrial robots that can simultaneously achieve multiple properties such as high wear resistance, high flexibility, and long-term oil resistance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a flexible cable for industrial robots and a method for its preparation.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A flexible cable for industrial robots includes a conductor made of multiple tinned copper wires twisted together, an insulation layer covering the conductor to form a core, a cable core made of at least two cores twisted together, and a filler at the axial position of the cable, and an inner sheath, a shielding layer, and an outer sheath wrapped around the cable core from the inside out.

[0008] The outer sheath is made of the following components in parts by weight: 90-100 parts of polyether-type TPU, 13-17 parts of modified reinforcing filler, 7-10 parts of flame retardant, 5-10 parts of plasticizer, 1-2 parts of antioxidant, 0.5-1.5 parts of lubricant, and 0.3-0.6 parts of light stabilizer.

[0009] In this invention, the outer sheath uses polyether-type TPU as the matrix, providing excellent resilience and low-temperature flexibility. Modified reinforcing fillers are added as the core, which also endows the material with excellent wear resistance and oil resistance. Flame retardants (such as ammonium polyphosphate, BDP, and magnesium hydroxide) ensure the safety of the cable. Plasticizers adjust the hardness and processability of the material. The combination of antioxidants, lubricants, and light stabilizers ensures the performance stability of the outer sheath in long-term use and in complex environments (such as heat, oxygen, and ultraviolet radiation).

[0010] Preferably, the stranding pitch of the conductor is 9-12 times the outer diameter of the conductor; the stranding pitch of the cable core is 4-6 times the outer diameter of the cable core; and the shielding layer is woven from fine copper wires into a mesh, with a coverage of over 85%.

[0011] In this invention, a smaller core stranding pitch is set, which effectively improves the structural stability and roundness of the cable under severe torsion and prevents the core from loosening and deforming.

[0012] Preferably, the modified reinforcing filler is prepared by the following method:

[0013] S1. Mix nano-silica and talc powder evenly, then add to nitric acid solution for impregnation treatment. After treatment, filter, wash and dry to obtain composite filler.

[0014] S2. Add the composite filler from step S1 to an ethanol aqueous solution, then add γ-aminopropyltriethoxysilane, stir and react, and after the reaction is complete, filter, wash and dry to obtain the pretreated composite filler.

[0015] S3. Add the composite filler from step S2 to toluene, then add glycidyl methacrylate and triethylamine, and heat to react. After the reaction is complete, filter, wash and dry to obtain the organic composite filler.

[0016] S4. Add the organic composite filler from step S3 to DMF, then add 1-adamantyl methacrylate and azobisisobutyronitrile, and carry out a constant temperature reaction. After the preset reaction time, add dodecafluoroheptyl methacrylate and continue the reaction for 1-2 hours. After the reaction is completed, filter, wash and dry to obtain the modified reinforced filler.

[0017] Preferably, in step S1, the mass ratio of nano-silica to talc is 2-3:7-8, the mass concentration of nitric acid is 15-20%, the impregnation temperature is 40-50℃, and the time is 1-2 hours.

[0018] In this invention, by combining nano-silica with talc, the micron-sized talc flakes provide basic rigidity, dimensional stability, and major oil-resistant barrier properties; the nano-silica has a large specific surface area, providing more reactive sites and acting as a nano-reinforcement for the outer sheath material. The combination of the two can achieve a balance between performance and cost; subsequently, acid washing can remove impurities from the filler surface and introduce more active hydroxyl groups.

[0019] Preferably, in step S2, the mass ratio of the composite filler and γ-aminopropyltriethoxysilane is 90-100:7-11; the temperature of the stirring reaction is 50-60℃, and the time is 2-3h.

[0020] In this invention, γ-aminopropyltriethoxysilane is used to modify the composite filler, introducing active amino groups on the substrate surface.

[0021] Preferably, in step S3, the mass ratio of the pretreated composite filler, glycidyl methacrylate, and triethylamine is 90-100:5-7:2-3, and the heating reaction temperature is 60-70℃ for 2-3 hours.

[0022] In this invention, glycidyl methacrylate is introduced into the composite filler by reacting the epoxy groups in glycidyl methacrylate with the amino groups in the pretreated composite filler. On the one hand, the ring-opening reaction forms new hydroxyl groups, which interact strongly with the ether or urethane bonds in the polyether-type TPU matrix through hydrogen bonds, improving the interfacial bonding force between the composite filler and the matrix material, and giving the outer sheath better mechanical properties. On the other hand, the introduced double bonds are beneficial to the subsequent reaction, and the molecular chains of glycidyl methacrylate themselves have a certain length and flexibility, providing greater steric hindrance, which is beneficial to improving the efficiency of the subsequent grafting reaction and the length of the grafted chains.

[0023] Preferably, in step S4, the mass ratio of the organic composite filler, 1-adamantyl methacrylate, dodecafluoroheptyl methacrylate, and azobisisobutyronitrile is 90-100:6-9:4-7:0.3-0.5, the temperature of the isothermal reaction is 65-75℃, and the preset time is 2-3 hours.

[0024] In this invention, 1-adamantyl methacrylate is first reacted with an organic composite filler containing a large, rigid cage-like adamantyl group, which provides the outer sheath with good wear resistance, scratch resistance, and toughening and reinforcement effects. Subsequently, dodecafluoroheptyl methacrylate is introduced, which contains a long perfluorocarbon chain and has extremely low surface energy, providing the outer sheath with excellent oil resistance, hydrophobicity, low coefficient of friction, and chemical corrosion resistance. Through the synergistic effect of the two substances, the overall performance of the cable outer sheath is improved.

[0025] Preferably, the flame retardant is one or more of ammonium polyphosphate, bisphenol A bis(diphenyl phosphate), and magnesium hydroxide; the plasticizer is one or more of dibutyl phthalate, diammonium phthalate, and dioctyl phthalate; the antioxidant is one or more of antioxidant 1010, antioxidant 1098, and antioxidant 168; the lubricant is silicone masterbatch; and the light stabilizer is one or more of UV-326, UV-327, and UV-1130.

[0026] Preferably, the outer sheath is prepared as follows: Weigh out polyether-type TPU, modified reinforcing filler, flame retardant, plasticizer, antioxidant, lubricant, and light stabilizer according to the formula, add them to a high-speed mixer, mix them evenly, and then add the mixture to a twin-screw extruder and granulate it at 180-220℃ to obtain the final product.

[0027] This invention also protects a method for preparing a flexible cable for industrial robots as described above, comprising the following steps:

[0028] Step 1: Conductor stranding: Multiple tin-plated copper wires are stranded together using a high-speed stranding machine to form a conductor;

[0029] Step 2, Insulation Extrusion: The stranded conductor is passed through an insulation extrusion production line to coat it with a layer of insulating material, thus obtaining an insulated wire core;

[0030] Step 3: Cable core assembly: Two or more cores are twisted together around a central core using a cable assembly machine to obtain the cable core;

[0031] Step 4, Inner Sheath Extrusion and Shielding Layer Braiding: After the cable core is cabled, it is extruded and covered with a PVC inner sheath. Then the cable core with the inner sheath is fed into a high-speed braiding machine, and tinned copper wire is used to braid its surface to form a mesh shielding layer.

[0032] Step 5: Outer sheath extrusion: The outer sheath is extruded over the shielding layer using an extruder to obtain the flexible cable for industrial robots.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The flexible cable for industrial robots provided by the present invention achieves overall performance improvement through the synergistic optimization of the cable's physical structure and the chemical formula of the outer sheath. Structurally, by setting a smaller conductor stranding pitch and cable core stranding pitch and adding center filler, the structural stability and roundness of the cable under severe torsion are effectively improved, preventing the cable core from loosening and deforming. At the same time, the high-coverage braided shielding layer provides excellent electromagnetic compatibility protection for signal transmission. In terms of the outer sheath, by introducing specially designed modified reinforcing filler into the outer sheath, the cable has been significantly enhanced in terms of wear resistance, oil resistance, flexibility and long-term reliability. Ultimately, it can meet the requirements of industrial robots in high-frequency, large-range movement and complex and harsh industrial environments, effectively extending the service life of the cable and reducing maintenance costs.

[0035] (2) The flexible cable for industrial robots provided by the present invention incorporates modified reinforcing fillers. By grafting polymerization of nano-silica and talc composite fillers on the surface of the fillers using specific steps, a variety of functional groups are successfully introduced. Specifically, the first introduced 1-adamantyl methacrylate, with its rigid cage structure, endows the filler with excellent wear resistance, strength and heat resistance support. The subsequently introduced dodecafluoroheptyl methacrylate, with its fluorine-containing long chain, endows the filler surface with extremely low surface energy. That is, by introducing 1-adamantyl methacrylate and dodecafluoroheptyl methacrylate into the composite filler in sequence, the present invention enables the modified composite filler to have good internal strength and wear resistance, while the external surface has better oil resistance, hydrophobicity and low friction coefficient. The synergistic effect of the two substances enables the final TPU outer sheath to have multiple properties at the molecular level.

[0036] (3) The flexible cable for industrial robots provided by the present invention forms a strong chemical bond between the inorganic filler and the TPU matrix resin through silane coupling agent and subsequent chemical reaction. Compared with simple physical blending, this chemical bonding ensures that the filler can be uniformly dispersed in the TPU matrix and effectively suppresses the phenomenon of "debonding" between the filler and the matrix under high stress or long-term bending fatigue. Through specific modification steps, the composite filler and the matrix have excellent interfacial compatibility, ensuring that stress can be efficiently transferred from the soft TPU matrix to the high-strength filler, thereby significantly improving the overall mechanical properties and structural stability of the composite material. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the flexible cable of the present invention.

[0038] The components are: 1. Tinned copper wire; 2. Insulation layer; 3. Filler; 4. Inner sheath layer; 5. Shielding layer; 6. Outer sheath. Detailed Implementation

[0039] The technical solutions of 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, 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.

[0040] The polyether-type TPU is BASF 1190A; the nano-silica has a particle size of 300-400 nm, and the talc has a particle size of 20-30 μm.

[0041] Example 1

[0042] A flexible cable for industrial robots includes a conductor made of multiple tinned copper wires 1 twisted together, an insulation layer 2 covering the conductor core, a cable core made of at least two wire cores twisted together, a filler 3 provided at the axial position of the cable, and an inner sheath layer 4, a shielding layer 5 and an outer sheath 6 wrapped around the cable core from the inside out.

[0043] The outer sheath is made of the following components in parts by weight: 95 parts polyether-type TPU, 15 parts modified reinforcing filler, 8 parts ammonium polyphosphate, 8 parts dibutyl phthalate, 1.5 parts antioxidant 1098, 1 part silicone masterbatch, and 0.5 parts UV-326.

[0044] The method for preparing the modified reinforced filler is as follows:

[0045] S1. Mix 25g of nano-silica and 75g of talc powder evenly, then add to 800mL of 20% nitric acid solution and impregnate at 45℃ for 1.5h. After treatment, filter, wash and dry to obtain composite filler.

[0046] S2. Add 95g of composite filler from step S1 to 1L of ethanol aqueous solution (ethanol to water volume ratio of 3:1), then add 9g of γ-aminopropyltriethoxysilane, stir and react at 55℃ for 2.5h, filter, wash and dry after the reaction is complete to obtain pretreated composite filler.

[0047] S3. Add 95g of the pretreated composite filler from step S2 to 1L of toluene, then add 6g of glycidyl methacrylate and 2.5g of triethylamine, and react at 65℃ for 2.5h. After the reaction is complete, filter, wash and dry to obtain the organic composite filler.

[0048] S4. Add 95g of organic composite filler from step S3 to 1L of DMF, then add 8g of 1-adamantyl methacrylate and 0.4g of azobisisobutyronitrile, and react at a constant temperature of 70℃ for 2.5h. After the reaction is completed, add 6g of dodecafluoroheptyl methacrylate and continue the reaction for 1.5h. After the reaction is completed, filter, wash and dry to obtain the modified reinforced filler.

[0049] The preparation method of the outer sheath is as follows: Weigh out polyether-type TPU, modified reinforcing filler, ammonium polyphosphate, dibutyl phthalate, antioxidant 1098, silicone masterbatch, and UV-326 according to the formula, add them to a high-speed mixer, mix them evenly, and then add the mixture to a twin-screw extruder and granulate it at 220°C to obtain the final product.

[0050] A method for manufacturing a flexible cable for industrial robots includes the following steps:

[0051] Step 1: Conductor stranding: Multiple tin-plated copper wires are stranded together using a high-speed stranding machine to form a conductor. The stranding pitch of the conductor is 10 times the outer diameter of the conductor.

[0052] Step 2, Insulation Extrusion: The stranded conductor is passed through an insulation extrusion production line to coat it with a layer of insulating material, thus obtaining an insulated wire core;

[0053] Step 3: Cable core formation: Two or more cores are twisted together around a central core using a cable forming machine to obtain the cable core. The twisting pitch of the cable core is 5 times the outer diameter of the cable core.

[0054] Step 4: Inner Sheath Extrusion and Shielding Layer Braiding: The cable core after cabling is passed through an extruder to cover it with a PVC inner sheath. Then, the cable core with the inner sheath is fed into a high-speed braiding machine, where tinned copper wire is used to braid its surface to form a mesh shielding layer with a coverage of 90%.

[0055] Step 5: Outer sheath extrusion: The outer sheath is extruded over the shielding layer using an extruder to obtain the flexible cable for industrial robots.

[0056] Example 2

[0057] A flexible cable for industrial robots includes a conductor made of multiple tinned copper wires 1 twisted together, an insulation layer 2 covering the conductor core, a cable core made of at least two wire cores twisted together, a filler 3 provided at the axial position of the cable, and an inner sheath layer 4, a shielding layer 5 and an outer sheath 6 wrapped around the cable core from the inside out.

[0058] The outer sheath is made of the following components in parts by weight: 90 parts of polyether-type TPU, 13 parts of modified reinforcing filler, 7 parts of ammonium polyphosphate, 5 parts of diammonium phthalate, 1 part of antioxidant 1098, 0.5 parts of silicone masterbatch, and 0.3 parts of UV-327.

[0059] The method for preparing the modified reinforced filler is as follows:

[0060] S1. Mix 20g of nano-silica with 80g of talc powder evenly, then add it to 800mL of 15% nitric acid solution and impregnate at 40℃ for 2h. After the treatment is completed, filter, wash and dry to obtain composite filler.

[0061] S2. Add 90g of composite filler from step S1 to 1L of ethanol aqueous solution (ethanol to water volume ratio of 3:1), then add 7g of γ-aminopropyltriethoxysilane, stir and react at 50℃ for 3h, filter, wash and dry after the reaction is completed to obtain pretreated composite filler.

[0062] S3. Add 90g of the pretreated composite filler from step S2 to 1L of toluene, then add 5g of glycidyl methacrylate and 2g of triethylamine, and react at 60℃ for 3h. After the reaction is complete, filter, wash and dry to obtain the organic composite filler.

[0063] S4. Add 90g of organic composite filler from step S3 to 1L of DMF, then add 6g of 1-adamantyl methacrylate and 0.3g of azobisisobutyronitrile, and react at a constant temperature of 65℃. After reacting for 3 hours, add 4g of dodecafluoroheptyl methacrylate and continue reacting for 2 hours. After the reaction is completed, filter, wash and dry to obtain the modified reinforced filler.

[0064] The preparation method of the outer sheath is as follows: Weigh out polyether-type TPU, modified reinforcing filler, ammonium polyphosphate, diammonium phthalate, antioxidant 1098, silicone masterbatch, and UV-327 according to the formula, add them to a high-speed mixer, mix them evenly, and then add the mixture to a twin-screw extruder and extrude and granulate it at 220°C to obtain the final product.

[0065] A method for manufacturing a flexible cable for industrial robots includes the following steps:

[0066] Step 1: Conductor stranding: Multiple tin-plated copper wires are stranded together using a high-speed stranding machine to form a conductor. The stranding pitch of the conductor is 10 times the outer diameter of the conductor.

[0067] Step 2, Insulation Extrusion: The stranded conductor is passed through an insulation extrusion production line to coat it with a layer of insulating material, thus obtaining an insulated wire core;

[0068] Step 3: Cable core formation: Two or more cores are twisted together around a central core using a cable forming machine to obtain the cable core. The twisting pitch of the cable core is 5 times the outer diameter of the cable core.

[0069] Step 4: Inner Sheath Extrusion and Shielding Layer Braiding: The cable core after cabling is passed through an extruder to cover it with a PVC inner sheath. Then, the cable core with the inner sheath is fed into a high-speed braiding machine, where tinned copper wire is used to braid its surface to form a mesh shielding layer with a coverage of 90%.

[0070] Step 5: Outer sheath extrusion: The outer sheath is extruded over the shielding layer using an extruder to obtain the flexible cable for industrial robots.

[0071] Example 3

[0072] A flexible cable for industrial robots includes a conductor made of multiple tinned copper wires 1 twisted together, an insulation layer 2 covering the conductor core, a cable core made of at least two wire cores twisted together, a filler 3 provided at the axial position of the cable, and an inner sheath layer 4, a shielding layer 5 and an outer sheath 6 wrapped around the cable core from the inside out.

[0073] The outer sheath is made of the following components in parts by weight: 100 parts of polyether-type TPU, 17 parts of modified reinforcing filler, 10 parts of ammonium polyphosphate, 10 parts of dioctyl phthalate, 2 parts of antioxidant 1098, 1.5 parts of silicone masterbatch, and 0.6 parts of UV-1130.

[0074] The method for preparing the modified reinforced filler is as follows:

[0075] S1. Mix 30g of nano-silica and 70g of talc powder evenly, then add it to 800mL of 20% nitric acid solution and impregnate at 50℃ for 1h. After the treatment is completed, filter, wash and dry to obtain composite filler.

[0076] S2. Add 100g of composite filler from step S1 to 1L of ethanol aqueous solution (ethanol to water volume ratio of 3:1), then add 11g of γ-aminopropyltriethoxysilane, stir and react at 60℃ for 2h, filter, wash and dry after the reaction is completed to obtain pretreated composite filler.

[0077] S3. Add 100g of the pretreated composite filler from step S2 to 1L of toluene, then add 7g of glycidyl methacrylate and 3g of triethylamine, and react at 70℃ for 2h. After the reaction is complete, filter, wash and dry to obtain the organic composite filler.

[0078] S4. Add 100g of organic composite filler from step S3 to 1L of DMF, then add 9g of 1-adamantyl methacrylate and 0.5g of azobisisobutyronitrile, and react at a constant temperature of 75℃. After reacting for 2 hours, add 7g of dodecafluoroheptyl methacrylate and continue reacting for 1 hour. After the reaction is completed, filter, wash and dry to obtain the modified reinforced filler.

[0079] The preparation method of the outer sheath is as follows: Weigh out polyether-type TPU, modified reinforcing filler, ammonium polyphosphate, dioctyl phthalate, antioxidant 1098, silicone masterbatch, and UV-1130 according to the formula, add them to a high-speed mixer, mix them evenly, and then add the mixture to a twin-screw extruder and granulate it at 220°C to obtain the final product.

[0080] A method for manufacturing a flexible cable for industrial robots includes the following steps:

[0081] Step 1: Conductor stranding: Multiple tin-plated copper wires are stranded together using a high-speed stranding machine to form a conductor. The stranding pitch of the conductor is 10 times the outer diameter of the conductor.

[0082] Step 2, Insulation Extrusion: The stranded conductor is passed through an insulation extrusion production line to coat it with a layer of insulating material, thus obtaining an insulated wire core;

[0083] Step 3: Cable core formation: Two or more cores are twisted together around a central core using a cable forming machine to obtain the cable core. The twisting pitch of the cable core is 5 times the outer diameter of the cable core.

[0084] Step 4: Inner Sheath Extrusion and Shielding Layer Braiding: The cable core after cabling is passed through an extruder to cover it with a PVC inner sheath. Then, the cable core with the inner sheath is fed into a high-speed braiding machine, where tinned copper wire is used to braid its surface to form a mesh shielding layer with a coverage of 90%.

[0085] Step 5: Outer sheath extrusion: The outer sheath is extruded over the shielding layer using an extruder to obtain the flexible cable for industrial robots.

[0086] Comparative Example 1

[0087] A flexible cable for industrial robots includes a conductor made of multiple tinned copper wires 1 twisted together, an insulation layer 2 covering the conductor core, a cable core made of at least two wire cores twisted together, a filler 3 provided at the axial position of the cable, and an inner sheath layer 4, a shielding layer 5 and an outer sheath 6 wrapped around the cable core from the inside out.

[0088] The outer sheath is made of the following components in parts by weight: 95 parts polyether-type TPU, 15 parts modified reinforcing filler, 8 parts ammonium polyphosphate, 8 parts dibutyl phthalate, 1.5 parts antioxidant 1098, 1 part silicone masterbatch, and 0.5 parts UV-326.

[0089] The method for preparing the modified reinforced filler is as follows:

[0090] S1. Mix 25g of nano-silica and 75g of talc powder evenly, then add to 800mL of 20% nitric acid solution and impregnate at 45℃ for 1.5h. After treatment, filter, wash and dry to obtain composite filler.

[0091] S2. Add 95g of composite filler from step S1 to 1L of ethanol aqueous solution (ethanol to water volume ratio of 3:1), then add 9g of γ-aminopropyltriethoxysilane, stir and react at 55℃ for 2.5h, filter, wash and dry after the reaction is complete to obtain pretreated composite filler.

[0092] S3. Add 95g of the pretreated composite filler from step S2 to 1L of toluene, then add 6g of glycidyl methacrylate and 2.5g of triethylamine, and react at 65℃ for 2.5h. After the reaction is complete, filter, wash and dry to obtain the organic composite filler.

[0093] S4. Add 95g of organic composite filler from step S3 to 1L of DMF, then add 8g of 1-adamantyl methacrylate and 0.4g of azobisisobutyronitrile, and react at 70℃ for 2.5h. After the reaction is complete, filter, wash and dry to obtain the modified reinforced filler.

[0094] The preparation method of the outer sheath is as follows: Weigh out polyether-type TPU, modified reinforcing filler, ammonium polyphosphate, dibutyl phthalate, antioxidant 1098, silicone masterbatch, and UV-326 according to the formula, add them to a high-speed mixer, mix them evenly, and then add the mixture to a twin-screw extruder and granulate it at 220°C to obtain the final product.

[0095] A method for manufacturing a flexible cable for industrial robots includes the following steps:

[0096] Step 1: Conductor stranding: Multiple tin-plated copper wires are stranded together using a high-speed stranding machine to form a conductor. The stranding pitch of the conductor is 10 times the outer diameter of the conductor.

[0097] Step 2, Insulation Extrusion: The stranded conductor is passed through an insulation extrusion production line to coat it with a layer of insulating material, thus obtaining an insulated wire core;

[0098] Step 3: Cable core formation: Two or more cores are twisted together around a central core using a cable forming machine to obtain the cable core. The twisting pitch of the cable core is 5 times the outer diameter of the cable core.

[0099] Step 4: Inner Sheath Extrusion and Shielding Layer Braiding: The cable core after cabling is passed through an extruder to cover it with a PVC inner sheath. Then, the cable core with the inner sheath is fed into a high-speed braiding machine, where tinned copper wire is used to braid its surface to form a mesh shielding layer with a coverage of 90%.

[0100] Step 5: Outer sheath extrusion: The outer sheath is extruded over the shielding layer using an extruder to obtain the flexible cable for industrial robots.

[0101] Compared to Example 1, this comparative example of modified reinforcing filler did not introduce dodecafluoroheptyl methacrylate.

[0102] Comparative Example 2

[0103] A flexible cable for industrial robots includes a conductor made of multiple tinned copper wires 1 twisted together, an insulation layer 2 covering the conductor core, a cable core made of at least two wire cores twisted together, a filler 3 provided at the axial position of the cable, and an inner sheath layer 4, a shielding layer 5 and an outer sheath 6 wrapped around the cable core from the inside out.

[0104] The outer sheath is made of the following components in parts by weight: 95 parts polyether-type TPU, 15 parts modified reinforcing filler, 8 parts ammonium polyphosphate, 8 parts dibutyl phthalate, 1.5 parts antioxidant 1098, 1 part silicone masterbatch, and 0.5 parts UV-326.

[0105] The method for preparing the modified reinforced filler is as follows:

[0106] S1. Mix 25g of nano-silica and 75g of talc powder evenly, then add to 800mL of 20% nitric acid solution and impregnate at 45℃ for 1.5h. After treatment, filter, wash and dry to obtain composite filler.

[0107] S2. Add 95g of composite filler from step S1 to 1L of ethanol aqueous solution (ethanol to water volume ratio of 3:1), then add 9g of γ-aminopropyltriethoxysilane, stir and react at 55℃ for 2.5h, filter, wash and dry after the reaction is complete to obtain pretreated composite filler.

[0108] S3. Add 95g of the pretreated composite filler from step S2 to 1L of toluene, then add 6g of glycidyl methacrylate and 2.5g of triethylamine, and react at 65℃ for 2.5h. After the reaction is complete, filter, wash and dry to obtain the organic composite filler.

[0109] S4. Add 95g of organic composite filler from step S3 to 1L of DMF, then add 6g of dodecafluoroheptyl methacrylate and 0.4g of azobisisobutyronitrile, and react at 70℃ for 2.5h. After the reaction is complete, filter, wash and dry to obtain the modified reinforced filler.

[0110] The preparation method of the outer sheath is as follows: Weigh out polyether-type TPU, modified reinforcing filler, ammonium polyphosphate, dibutyl phthalate, antioxidant 1098, silicone masterbatch, and UV-326 according to the formula, add them to a high-speed mixer, mix them evenly, and then add the mixture to a twin-screw extruder and granulate it at 220°C to obtain the final product.

[0111] A method for manufacturing a flexible cable for industrial robots includes the following steps:

[0112] Step 1: Conductor stranding: Multiple tin-plated copper wires are stranded together using a high-speed stranding machine to form a conductor. The stranding pitch of the conductor is 10 times the outer diameter of the conductor.

[0113] Step 2, Insulation Extrusion: The stranded conductor is passed through an insulation extrusion production line to coat it with a layer of insulating material, thus obtaining an insulated wire core;

[0114] Step 3: Cable core formation: Two or more cores are twisted together around a central core using a cable forming machine to obtain the cable core. The twisting pitch of the cable core is 5 times the outer diameter of the cable core.

[0115] Step 4: Inner Sheath Extrusion and Shielding Layer Braiding: The cable core after cabling is passed through an extruder to cover it with a PVC inner sheath. Then, the cable core with the inner sheath is fed into a high-speed braiding machine, where tinned copper wire is used to braid its surface to form a mesh shielding layer with a coverage of 90%.

[0116] Step 5: Outer sheath extrusion: The outer sheath is extruded over the shielding layer using an extruder to obtain the flexible cable for industrial robots.

[0117] Compared to Example 1, this comparative example of modified reinforcing filler did not introduce 1-adamantyl methacrylate.

[0118] Comparative Example 3

[0119] A flexible cable for industrial robots includes a conductor made of multiple tinned copper wires 1 twisted together, an insulation layer 2 covering the conductor core, a cable core made of at least two wire cores twisted together, a filler 3 provided at the axial position of the cable, and an inner sheath layer 4, a shielding layer 5 and an outer sheath 6 wrapped around the cable core from the inside out.

[0120] The outer sheath is made of the following components in parts by weight: 95 parts polyether-type TPU, 15 parts modified reinforcing filler, 8 parts ammonium polyphosphate, 8 parts dibutyl phthalate, 1.5 parts antioxidant 1098, 1 part silicone masterbatch, and 0.5 parts UV-326.

[0121] The method for preparing the modified reinforced filler is as follows:

[0122] S1. Mix 25g of nano-silica and 75g of talc powder evenly, then add to 800mL of 20% nitric acid solution and impregnate at 45℃ for 1.5h. After treatment, filter, wash and dry to obtain composite filler.

[0123] S2. Add 95g of composite filler from step S1 to 1L of ethanol aqueous solution (ethanol to water volume ratio of 3:1), then add 9g of γ-aminopropyltriethoxysilane, stir and react at 55℃ for 2.5h, filter, wash and dry after the reaction is complete to obtain pretreated composite filler.

[0124] S3. Add 95g of the pretreated composite filler from step S2 to 1L of toluene, then add 6g of glycidyl methacrylate and 2.5g of triethylamine, and react at 65℃ for 2.5h. After the reaction is complete, filter, wash and dry to obtain the modified reinforced filler.

[0125] The preparation method of the outer sheath is as follows: Weigh out polyether-type TPU, modified reinforcing filler, ammonium polyphosphate, dibutyl phthalate, antioxidant 1098, silicone masterbatch, and UV-326 according to the formula, add them to a high-speed mixer, mix them evenly, and then add the mixture to a twin-screw extruder and granulate it at 220°C to obtain the final product.

[0126] A method for manufacturing a flexible cable for industrial robots includes the following steps:

[0127] Step 1: Conductor stranding: Multiple tin-plated copper wires are stranded together using a high-speed stranding machine to form a conductor. The stranding pitch of the conductor is 10 times the outer diameter of the conductor.

[0128] Step 2, Insulation Extrusion: The stranded conductor is passed through an insulation extrusion production line to coat it with a layer of insulating material, thus obtaining an insulated wire core;

[0129] Step 3: Cable core formation: Two or more cores are twisted together around a central core using a cable forming machine to obtain the cable core. The twisting pitch of the cable core is 5 times the outer diameter of the cable core.

[0130] Step 4: Inner Sheath Extrusion and Shielding Layer Braiding: The cable core after cabling is passed through an extruder to cover it with a PVC inner sheath. Then, the cable core with the inner sheath is fed into a high-speed braiding machine, where tinned copper wire is used to braid its surface to form a mesh shielding layer with a coverage of 90%.

[0131] Step 5: Outer sheath extrusion: The outer sheath is extruded over the shielding layer using an extruder to obtain the flexible cable for industrial robots.

[0132] Compared with Example 1, the modified reinforcing filler in this comparative example did not introduce 1-adamantyl methacrylate and dodecafluoroheptyl methacrylate.

[0133] Comparative Example 4

[0134] A flexible cable for industrial robots includes a conductor made of multiple tinned copper wires 1 twisted together, an insulation layer 2 covering the conductor core, a cable core made of at least two wire cores twisted together, a filler 3 provided at the axial position of the cable, and an inner sheath layer 4, a shielding layer 5 and an outer sheath 6 wrapped around the cable core from the inside out.

[0135] The outer sheath is made of the following components in parts by weight: 95 parts polyether-type TPU, 15 parts modified reinforcing filler, 8 parts ammonium polyphosphate, 8 parts dibutyl phthalate, 1.5 parts antioxidant 1098, 1 part silicone masterbatch, and 0.5 parts UV-326.

[0136] The method for preparing the modified reinforced filler is as follows:

[0137] S1. Mix 25g of nano-silica and 75g of talc powder evenly, then add to 800mL of 20% nitric acid solution and impregnate at 45℃ for 1.5h. After treatment, filter, wash and dry to obtain composite filler.

[0138] S2. Add 95g of composite filler from step S1 to 1L of ethanol aqueous solution (ethanol to water volume ratio of 3:1), then add 9g of γ-aminopropyltriethoxysilane, stir and react at 55℃ for 2.5h, filter, wash and dry after the reaction is complete to obtain pretreated composite filler.

[0139] S3. Add 95g of pretreated composite filler from step S2 to 1L of DMF, then add 8g of 1-adamantyl methacrylate and 0.4g of azobisisobutyronitrile, and react at a constant temperature of 70℃ for 2.5h. After the reaction is completed, add 6g of dodecafluoroheptyl methacrylate and continue the reaction for 1.5h. After the reaction is completed, filter, wash and dry to obtain the modified reinforced filler.

[0140] The preparation method of the outer sheath is as follows: Weigh out polyether-type TPU, modified reinforcing filler, ammonium polyphosphate, dibutyl phthalate, antioxidant 1098, silicone masterbatch, and UV-326 according to the formula, add them to a high-speed mixer, mix them evenly, and then add the mixture to a twin-screw extruder and granulate it at 220°C to obtain the final product.

[0141] A method for manufacturing a flexible cable for industrial robots includes the following steps:

[0142] Step 1: Conductor stranding: Multiple tin-plated copper wires are stranded together using a high-speed stranding machine to form a conductor. The stranding pitch of the conductor is 10 times the outer diameter of the conductor.

[0143] Step 2, Insulation Extrusion: The stranded conductor is passed through an insulation extrusion production line to coat it with a layer of insulating material, thus obtaining an insulated wire core;

[0144] Step 3: Cable core formation: Two or more cores are twisted together around a central core using a cable forming machine to obtain the cable core. The twisting pitch of the cable core is 5 times the outer diameter of the cable core.

[0145] Step 4: Inner Sheath Extrusion and Shielding Layer Braiding: The cable core after cabling is passed through an extruder to cover it with a PVC inner sheath. Then, the cable core with the inner sheath is fed into a high-speed braiding machine, where tinned copper wire is used to braid its surface to form a mesh shielding layer with a coverage of 90%.

[0146] Step 5: Outer sheath extrusion: The outer sheath is extruded over the shielding layer using an extruder to obtain the flexible cable for industrial robots.

[0147] Compared to Example 1, glycidyl methacrylate was not introduced into the modified reinforcing filler of this comparative example.

[0148] The outer sheaths prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests. Tensile strength and elongation at break were tested according to GB / T2951.11-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Cables - Part 11: General Test Methods - Thickness and Dimensional Measurements - Mechanical Properties Tests". The unnotched impact strength of the outer sheath was determined according to GB / T 1843-2008 "Determination of Impact Strength of Plastic Cantilever Beams" at a test temperature of -20℃. Abrasion resistance was tested according to GB / T 3960-2016 "Plastics - Test Method for Sliding Friction and Abrasion". During the test, the sample remained stationary, the test ring rotated at 200 r / min, the test time was 2 hours, the load was 196 N, and the test was conducted under unlubricated conditions. Oil resistance was tested by immersing the sample in IRM. The samples were immersed in 902 oil for 72 hours at 100℃. After the immersion test, the residual liquid was wiped off immediately, and the tensile strength and elongation at break of the samples were tested, and the retention rate was calculated. The test results are shown in Table 1 below.

[0149] Table 1 Performance test results of outer sheath for each group

[0150] Tensile strength / MPa Elongation at break / % <![CDATA[Izod impact strength (kJ / m 2 )]]> Mass wear (mg) Oil resistance strength retention rate Oil resistance elongation at break retention rate Example 1 53.1 390 38.5 10.5 82.1 79.3 Example 2 51.7 358 37.3 12.2 80.9 76.1 Example 3 52.6 381 38.1 11.4 81.7 77.8 Comparative Example 1 48.8 332 35.7 16.6 61.8 57.4 Comparative Example 2 47.5 316 34.2 21.3 70.6 65.5 Comparative Example 3 46.2 301 31.4 25.7 56.3 50.9 Comparative Example 4 47.9 323 34.8 18.1 65.2 60.7

[0151] As can be seen from Table 1 above, the outer sheath prepared by this invention has good mechanical properties, impact resistance, and wear resistance, as well as excellent oil resistance, resulting in a flexible cable with good overall performance. In contrast, Comparative Example 1, due to the absence of dodecylfluoroheptyl methacrylate in the modified reinforcing filler, showed a significant decrease in the oil resistance of the outer sheath; Comparative Example 2, due to the absence of 1-adamantyl methacrylate in the modified reinforcing filler, showed a significant decrease in wear resistance; Comparative Example 3, due to the absence of both 1-adamantyl methacrylate and dodecylfluoroheptyl methacrylate in the modified reinforcing filler, showed a significant decrease in both wear resistance and oil resistance; and Comparative Example 4, due to the absence of glycidyl methacrylate in the modified reinforcing filler, prevented 1-adamantyl methacrylate and dodecylfluoroheptyl methacrylate from chemically bonding with the composite filler, and its overall performance was also lower than that of Example 1.

[0152] The above description is a further detailed explanation of the present invention in conjunction with specific implementation examples. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the protection scope of the present invention.

[0153] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A flexible cable for industrial robots, characterized in that, The flexible cable for industrial robots includes a conductor made of multiple tinned copper wires (1) twisted together, an insulation layer (2) covering the conductor to form a core, a cable core made of at least two cores twisted together, and a filler (3) provided at the axial position of the cable, and an inner sheath layer (4), a protective layer, a shielding layer (5) and an outer sheath (6) wrapped around the cable core from the inside out. The outer sheath is made of the following components in parts by weight: 90-100 parts of polyether-type TPU, 13-17 parts of modified reinforcing filler, 7-10 parts of flame retardant, 5-10 parts of plasticizer, 1-2 parts of antioxidant, 0.5-1.5 parts of lubricant, and 0.3-0.6 parts of light stabilizer. The method for preparing the modified reinforced filler is as follows: S1. Mix nano-silica and talc powder evenly, then add them to nitric acid solution for impregnation treatment. After the treatment is completed, a composite filler is obtained. S2. Add the composite filler to an ethanol aqueous solution, then add γ-aminopropyltriethoxysilane, and stir to react. After the reaction is complete, the pretreated composite filler is obtained. S3. Add the pretreated composite filler to toluene, then add glycidyl methacrylate and triethylamine, and heat to react. After the reaction is complete, the organic composite filler is obtained. S4. Add the organic composite filler to DMF, then add 1-adamantyl methacrylate and azobisisobutyronitrile, and carry out a constant temperature reaction. After the preset reaction time, add dodecafluoroheptyl methacrylate and continue the reaction for 1-2 hours. After the reaction is completed, the modified reinforced filler is obtained.

2. The flexible cable for industrial robots according to claim 1, characterized in that, The stranding pitch of the conductor is 9-12 times the outer diameter of the conductor; the stranding pitch of the cable core is 4-6 times the outer diameter of the cable core; the shielding layer is woven from fine copper wires into a mesh, with a coverage of over 85%.

3. The flexible cable for industrial robots according to claim 1, characterized in that, In step S1, the mass ratio of nano-silica to talc is (2-3):(7-8), the mass concentration of nitric acid is 15-20%, the impregnation temperature is 40-50℃, and the time is 1-2h.

4. The flexible cable for industrial robots according to claim 1, characterized in that, In step S2, the mass ratio of the composite filler and γ-aminopropyltriethoxysilane is (90-100):(7-11); the stirring reaction temperature is 50-60℃ and the time is 2-3h.

5. The flexible cable for industrial robots according to claim 1, characterized in that, In step S3, the mass ratio of the pretreated composite filler, glycidyl methacrylate, and triethylamine is (90-100):(5-7):(2-3), and the heating reaction temperature is 60-70℃ for 2-3 hours.

6. The flexible cable for industrial robots according to claim 1, characterized in that, In step S4, the mass ratio of the organic composite filler, 1-adamantyl methacrylate, dodecafluoroheptyl methacrylate, and azobisisobutyronitrile is (90-100):(6-9):(4-7):(0.3-0.5), the temperature of the isothermal reaction is 65-75℃, and the preset time is 2-3h.

7. The flexible cable for industrial robots according to claim 1, characterized in that, The flame retardant is one or more of ammonium polyphosphate, bisphenol A bis(diphenyl) phosphate, and magnesium hydroxide; the plasticizer is one or more of dibutyl phthalate, diammonium phthalate, and dioctyl phthalate; the antioxidant is one or more of antioxidant 1010, antioxidant 1098, and antioxidant 168; the lubricant is silicone masterbatch; and the light stabilizer is one or more of UV-326, UV-327, and UV-1130.

8. The flexible cable for industrial robots according to claim 1, characterized in that, The preparation method of the outer sheath is as follows: Weigh out polyether-type TPU, modified reinforcing filler, flame retardant, plasticizer, antioxidant, lubricant and light stabilizer according to the formula, add them to a high-speed mixer and mix evenly. Then add the mixture to a twin-screw extruder and extrude and granulate at 180-220℃ to obtain the final product.

9. A method for preparing a flexible cable for an industrial robot as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Conductor stranding: Multiple tin-plated copper wires are stranded together using a high-speed stranding machine to form a conductor; Step 2, Insulation Extrusion: The stranded conductor is passed through an insulation extrusion production line to coat it with a layer of insulating material, thus obtaining an insulated wire core; Step 3: Cable core assembly: Two or more cores are twisted together around a central core using a cable assembly machine to obtain the cable core; Step 4, Inner Sheath Extrusion and Shielding Layer Braiding: After the cable core is cabled, it is extruded and covered with a PVC inner sheath. Then the cable core with the inner sheath is fed into a high-speed braiding machine, and tinned copper wire is used to braid its surface to form a mesh shielding layer. Step 5: Outer sheath extrusion: The outer sheath is extruded over the shielding layer using an extruder to obtain the flexible cable for industrial robots.

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