Robot special intelligent high-thermal-conductivity anti-fatigue silicone rubber cable and preparation method thereof

Abstract

The application relates to the technical field of special cables, in particular to a robot-special intelligent high-heat-conducting anti-fatigue silicon rubber cable and a preparation method thereof, which comprises, from inside to outside, a NiTi alloy-aramid intelligent tensile core, a gradient foaming silicon rubber filling body, an ultra-fine copper wire bundle twisted conductor, a nano boron nitride modified silicon rubber insulation layer, a silver nanowire / graphene hybrid shielding layer, an inner layer flexible silicon rubber sheath and an aramid fiber reinforced silicon rubber outer layer sheath. The application adds a flexible strain sensing module, realizes real-time monitoring of the strain state of the cable, realizes linkage early warning with a robot control system, reduces the risk of core breakage through double protection, adapts to the intelligent operation and maintenance demand process and is compatible with existing equipment, only needs to add small-sized equipment such as plasma etching and micro-gravure coating, and core materials are easy to obtain; the cost is reduced by 30%-40% compared with imported products, the domestic substitution can be realized, and the development demand of high-power and intelligent robots can be adapted.

Description

Technical Field

[0001] This invention relates to the field of special cable technology, and in particular to a robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable and its preparation method. Background Technology

[0002] Currently, robot-specific cables face several key technological bottlenecks under high-frequency, dynamic, high-power, and intelligent operation and maintenance conditions, including insufficient heat dissipation, poor shielding durability, lack of tensile strain response, uneven buffer protection, low vulcanization efficiency, and inability to monitor status in real time. Traditional silicone rubber nano-boron nitride modified silicone rubber insulation layers have a thermal conductivity of only 0.2~0.3 W / m·K, with heat accumulation accelerating insulation aging. Copper mesh or conductive silicone rubber silver nanowire / graphene hybrid shielding layers experience shielding effectiveness attenuation of ≥3dB after tens of millions of bends, leading to signal distortion. Pure aramid NiTi alloy-aramid intelligent tensile cores only provide static tensile strength, lacking strain monitoring and dynamic response capabilities. Single-density fillers easily cause stress concentration, and sudden changes in sheath hardness can easily trigger interlayer cracking. Traditional single-hot vulcanization processes have low production efficiency and insufficient deep vulcanization. Furthermore, existing cables lack integrated sensing modules, making real-time status monitoring of robot cabling impossible and hindering their adaptation to the intelligent operation and maintenance needs of smart manufacturing.

[0003] While silicone rubber possesses excellent flexibility and temperature resistance, its single material properties are insufficient to meet diverse needs. In existing technologies, cable structural layers are often directly bonded together, making interlayer bonding susceptible to bending. The silver nanowire / graphene hybrid shielding layer lacks a buffer structure and is prone to damage during dynamic bending. Sudden changes in sheath hardness can lead to stress concentration and cracking. The thermally conductive network in the nano-boron nitride modified silicone rubber insulation layer is insufficient, and the lack of thermally conductive filler between conductors can create thermal resistance. The lack of segmented temperature control during vulcanization can result in uneven cross-linking. The NiTi alloy-aramid intelligent tensile core only possesses mechanical properties and lacks intelligent sensing functionality.

[0004] This invention achieves a leapfrog upgrade in the performance of robot cables through synergistic innovations such as the synergistic modification of nano-boron nitride-nano silica with nano-boron nitride-modified silicone rubber insulation layer, silver nanowire / graphene hybrid shielding layer + elastic buffer substrate, NiTi alloy-aramid intelligent tensile core + flexible strain sensing module, gradient foamed silicone rubber filler + closed-cell structure optimization, gradient hardness connection of sheath layer, UV light-thermal segmented temperature-controlled double vulcanization, nano-thermal conductive silicone grease filling of conductor gaps, and plasma etching treatment of nano-boron nitride-modified silicone rubber insulation layer. It simultaneously solves problems such as heat dissipation, shielding durability, intelligent strain response and monitoring, buffer balancing, interlayer bonding, intelligent operation and maintenance, and production efficiency, and has significant technological innovation and industrial value. Summary of the Invention

[0005] The technical problem to be solved by this invention is that existing robot-specific cables have poor heat dissipation, low shielding durability, lack of intelligent strain monitoring and response, uneven buffer protection, insufficient interlayer bonding, sudden changes in sheath hardness leading to cracking, uneven vulcanization crosslinking, and high conductor thermal resistance.

[0006] The technical solution adopted by this invention to solve its technical problem is: a robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable, comprising, from the inside out, a NiTi alloy-aramid intelligent tensile core, a gradient foamed silicone rubber filler, an ultra-fine copper wire stranded conductor, a nano-boron nitride modified silicone rubber insulation layer, a silver nanowire / graphene hybrid shielding layer, an inner flexible silicone rubber sheath, and an aramid fiber reinforced silicone rubber outer sheath; the surface of the NiTi alloy-aramid intelligent tensile core is integrated with a flexible strain sensing module, which is connected to the robot control system signal; an elastic buffer substrate is provided between the silver nanowire / graphene hybrid shielding layer and the nano-boron nitride modified silicone rubber insulation layer; and a hardness transition layer is provided between the inner flexible silicone rubber sheath and the aramid fiber reinforced silicone rubber outer sheath.

[0007] The NiTi alloy-aramid intelligent tensile core is woven from NiTi alloy wire and aramid fiber in a 1:3 mass ratio, coated with a 0.05mm thick silicone rubber bonding layer, with a diameter of 1.0~2.0mm and a tensile strength ≥1800N; the flexible strain sensing module is a graphene-based flexible thin film sensor, attached to the outer surface of the NiTi alloy-aramid intelligent tensile core, with a detection accuracy of ±0.1% strain and an operating temperature of -40~120℃.

[0008] The gradient foamed silicone rubber filler has a three-layer density gradient structure, with the inner layer having a density of 0.3 g / cm³. 3 Middle layer 0.5g / cm 3 Outer layer 0.7g / cm 3 The filling density is ≥95%, the total thickness is 0.8~1.5mm, the compression set is ≤15%, and the energy absorption rate is ≥60%. The gradient foamed silicone rubber filler has a closed-cell structure with a pore size of 5~20μm, and the outer layer foam pore size is smaller than that of the inner layer.

[0009] The ultra-fine copper wire stranded conductor is made of 0.08mm ultra-fine oxygen-free copper wire stranded together, with a copper wire purity of ≥99.99%. After stranding 25~30 wires per bundle, it is divided into power core, control core, and signal core. The stranding gaps of the ultra-fine copper wire stranded conductor are filled with nano thermally conductive silicone grease, with a thermal conductivity of ≥2.0W / m·K.

[0010] The nano-boron nitride modified silicone rubber insulation layer is composed of 70wt% phenyl silicone rubber + 30wt% trifluoropropyl silicone rubber + 3wt% hydroxyl silicone oil + 1wt% KH550 modified boron nitride nanosheets + 15wt% silica + 0.8wt% vulcanizing agent bis 2,50.8wt%, and also contains 0.5wt% nano-silica coupling modifier. The thickness is 0.3~0.8mm, the thermal conductivity is ≥0.85W / m·K, and the breakdown field strength is ≥32kV / mm.

[0011] The silver nanowire / graphene hybrid shielding layer is a 3D-printed mesh structure with a pore size of 1 mm, a linewidth of 50 μm, and a thickness of 0.1~0.2 mm; the elastic buffer substrate is a silicone rubber microfoam layer with a thickness of 0.05~0.1 mm and a density of 0.4 g / cm³. 3 The silver nanowires in the silver nanowire / graphene hybrid shielding layer have an aspect ratio of ≥150, a single-layer graphene monolayer rate of ≥98%, and a shielding effectiveness of ≥88dB in the 30~1000MHz frequency band.

[0012] The inner flexible silicone rubber sheath has a Shore hardness of A60 and an elongation at break of ≥600%. The outer aramid fiber reinforced silicone rubber sheath has a Shore hardness of A70 and a tear strength of ≥45kN / m, with anti-slip texture on the outer surface. The hardness transition layer has a Shore hardness of A65 and a thickness of 0.2~0.3mm. It is made by blending and modifying vinyl silicone rubber and polyether silicone oil to achieve a gradient hardness transition of 60→65→70 for the sheath layer.

[0013] A method for preparing a robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable includes core material prefabrication, conductor preparation, encapsulation with a nano-boron nitride modified silicone rubber insulation layer, molding of a silver nanowire / graphene hybrid shielding layer, cable core bundling, double-layer sheath extrusion, UV-thermal segmented temperature-controlled double vulcanization, and post-treatment processes. The UV-thermal segmented temperature-controlled double vulcanization process includes a pre-vulcanization insulation section and a deep vulcanization uniform temperature section. Furthermore, the outer surface of the nano-boron nitride modified silicone rubber insulation layer is subjected to plasma etching treatment before the silver nanowire / graphene hybrid shielding layer is formed.

[0014] The process parameters for plasma etching are: argon atmosphere, power 100~150W, etching time 5~8min, etching depth 5~10μm; the elastic buffer substrate is coated on the outer surface of the etched nano boron nitride modified silicone rubber insulating layer by micro-gravure coating method, coating speed 8~10m / min, and pre-baked at 100℃ for 5min to form the substrate.

[0015] The ultraviolet light-thermal segmented temperature-controlled dual vulcanization process includes: UVLED ultraviolet pre-vulcanization, 365nm wavelength, 50mW / cm². 2Power, transmission speed 10m / min, irradiation 30s, pre-vulcanization insulation section temperature 80~90℃, insulation 10s, surface crosslinking rate ≥45%; hot air tunnel deep vulcanization, uniform temperature section temperature 170~180℃, vulcanization 30s, overall crosslinking rate ≥93%; the post-processing process also includes calibration and packaging of the flexible strain sensing module, the packaging material is heat-resistant silicone rubber, thickness 0.03~0.05mm.

[0016] The beneficial effects of this invention are: (1) The present invention adds a flexible strain sensing module to realize real-time monitoring of cable strain status with a detection accuracy of ±0.1% and linkage with robot control system for early warning; NiTi alloy-aramid intelligent tensile core recovery time ≤0.08s under 5% strain, double protection reduces the risk of core breakage and adapts to intelligent operation and maintenance requirements; (2) The nano boron nitride modified silicone rubber insulation layer has added nano silica coupling modifiers to synergistically construct a three-dimensional thermal conductive network with a thermal conductivity ≥0.85W / m·K, which is 2.5 times higher than the traditional one; the conductor gap is filled with nano thermal conductive silicone grease to eliminate air thermal resistance, and the overall thermal conductivity of the cable is improved by more than 40%. The insulation resistance decreases by ≤8% after aging at 120℃ for 720h, and the thermal conductivity is greatly improved. (3) A new elastic buffer substrate is added to absorb the bending impact and avoid rigid damage to the silver nanowire / graphene hybrid shielding layer; the aspect ratio of silver nanowires and the monolayer ratio of graphene are optimized, and the shielding attenuation is ≤0.8dB after 10 million bends, which is 4 times more durable than the traditional silver nanowire / graphene hybrid shielding layer. The shielding effectiveness in the 30~1000MHz frequency band is ≥89dB, and the shielding durability is significantly enhanced. (4) The gradient foamed silicone rubber filler has a new middle layer density transition and closed-cell pore size optimization, with an energy absorption rate of ≥60% and more uniform stress on the cable core; the sheath layer has a new hardness transition layer to achieve gradient hardness connection, eliminate interlayer stress concentration, and optimize the buffer and fatigue resistance performance of traditional cables. (5) The outer surface of the nano boron nitride modified silicone rubber insulation layer is newly treated with plasma etching to improve the surface roughness; a buffer / transition layer is added between each structural layer, and the interlayer peel strength is ≥2.2N / mm, which is 46.7% higher than the traditional one, avoiding interlayer cracking during dynamic bending and greatly improving the interlayer bonding force. (6) The UV-thermal dual vulcanization adds a pre-vulcanization insulation section and a deep vulcanization uniform temperature section, with an overall crosslinking rate of ≥93%, which is 3% higher than the traditional method. The vulcanization process is better and the product consistency is higher. (7) The process is compatible with existing equipment, requiring only the addition of small equipment such as plasma etching and micro-gravure coating. Core materials are readily available. The cost is 30% to 40% lower than imported products, enabling domestic substitution and meeting the development needs of high-power, intelligent robots. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] Figure 2 This is a partial schematic diagram of the nano-boron nitride modified silicone rubber insulating layer and the nano-silica coupling modifier in this invention.

[0020] Figure 3 This is a flowchart of the preparation process of the present invention.

[0021] In the figure: 1. NiTi alloy-aramid intelligent tensile core; 11. Flexible strain sensing module; 2. Gradient foamed silicone rubber filler; 3. Ultra-fine copper wire stranded conductor; 31. Nano thermally conductive silicone grease; 4. Nano boron nitride modified silicone rubber insulation layer; 41. Nano silica coupling modifier; 5. Silver nanowire / graphene hybrid shielding layer; 51. Elastic buffer substrate; 6. Inner flexible silicone rubber sheath; 7. Aramid fiber reinforced silicone rubber outer sheath; 71. Anti-slip texture; 8. Hardness transition layer. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] like Figure 1 , Figure 2 and Figure 3The robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable shown consists of, from the inside out, a NiTi alloy-aramid intelligent tensile core 1, a gradient foamed silicone rubber filler 2, an ultra-fine copper wire stranded conductor 3, a nano-boron nitride modified silicone rubber insulation layer 4, a silver nanowire / graphene hybrid shielding layer 5, an inner flexible silicone rubber sheath 6, and an aramid fiber reinforced silicone rubber outer sheath 7. A flexible strain sensing module 11 is integrated on the surface of the NiTi alloy-aramid intelligent tensile core 1. An elastic buffer substrate 51 is placed between the silver nanowire / graphene hybrid shielding layer 5 and the nano-boron nitride modified silicone rubber insulation layer 4. A hardness transition layer 8 is placed between the inner flexible silicone rubber sheath 6 and the aramid fiber reinforced silicone rubber outer sheath 7. The gaps between the strands of the ultra-fine copper wire stranded conductor 3 are filled with nano-thermal conductive silicone grease 31. A nano-silica coupling modifier 41 is added to the nano-boron nitride modified silicone rubber insulation layer 4. Each structural layer achieves multiple functions through innovative materials and processes. The specific composition is as follows: NiTi alloy-aramid intelligent tensile core 1 material composition: NiTi alloy wire (diameter 0.1mm, phase transformation temperature 40℃) and aramid fiber (monofilament strength 3.5GPa) are woven in a 1:3 mass ratio, coated with a silicone rubber adhesive layer (thickness 0.05mm), and a graphene-based flexible strain sensing module 11 is attached to the surface. Structural parameters: diameter 1.0~2.0mm, tensile strength ≥1800N, flexible strain sensing module 11 with detection accuracy ±0.1% strain, operating temperature -40~120℃; Functional advantages: NiTi alloy wire has shape memory effect, with a shape recovery time of ≤0.1s and a recovery rate of ≥98% under 5%~10% strain. Combined with the high strength of aramid fiber, it achieves dual functions of static tensile strength and dynamic strain response. The flexible strain sensing module 11 realizes real-time monitoring of cable strain status, links with the robot control system, and provides timely warning of overload risks to avoid overload core breakage during sudden robot movements.

[0025] Composition of Gradient-Bound Foamed Silicone Rubber Filler 2: The silicone rubber substrate is divided into three groups, with 0.5wt%, 1.0wt%, and 1.5wt% foaming agent added respectively, forming a density gradient structure (0.3→0.5→0.7g / cm³). 3 The foam has a closed-cell structure with a pore size of 5~20μm, and the outer layer foam has a smaller pore size than the inner layer. Structural parameters: The filling material between each core wire and the NiTi alloy-aramid intelligent tensile core 1 has a filling density of ≥95% and a total thickness of 0.8~1.5mm; Functional advantages: Low-density, highly flexible inner layer (0.3g / cm³) 3 The core wires are designed to buffer friction; the middle layer provides a balanced density for flexibility and support; and the outer layer offers high-density, strong support (0.7 g / cm³). 3It ensures the roundness of the cable core; the closed-cell structure reduces heat loss and medium penetration; the small-diameter outer layer enhances the support strength; the permanent compression deformation is ≤15% (50% compression rate, 22h); the energy absorption rate is ≥60%; and the fatigue resistance is significantly improved.

[0026] The ultra-fine copper wire stranded conductor 3 is composed of: 0.08mm ultra-fine oxygen-free copper wire (purity ≥99.99%), 25~30 wires / bundle, which are then stranded into a power core (2~4 cores), a control core (8~24 cores), and a signal core (2 cores). The gaps between the strands are filled with nano thermally conductive silicone grease 31 (thermal conductivity ≥2.0W / m·K). Structural parameters: Power core cross-section 1.0~2.5mm 2 The control core cross-section is 0.12~0.5mm. 2 The signal core cross-section is 0.12mm. 2 ; Functional advantages: The ultra-fine copper wire stranded design enhances the flexibility of the ultra-fine copper wire stranded conductor 3, and the nano thermal conductive silicone grease 31 fills the gaps in the ultra-fine copper wire stranded conductor 3, eliminating air thermal resistance and improving the overall thermal conductivity of the cable. The DC resistance meets the GB / T3956-2008 standard, making it suitable for high-frequency dynamic wiring in robots.

[0027] Composition of nano-boron nitride modified silicone rubber insulation layer 4: 70wt% phenyl silicone rubber (PMVQ) + 30wt% trifluoropropyl silicone rubber (FMVQ) + 3wt% hydroxyl silicone oil + KH550 modified boron nitride nanosheets (50nm, 1wt%) + 15wt% silica + 0.8wt% vulcanizing agent bis2 + 0.5wt% nano-silica coupling modifier 41 (0.5wt%). Structural parameters: Thickness 0.3~0.8mm, formed by double vulcanization process; Functional advantages: Boron nitride nanosheets and nano-silica coupling modifier 41 synergistically construct a three-dimensional thermally conductive network, which improves thermal conductivity and enhances the mechanical strength of the nano-boron nitride modified silicone rubber insulation layer 4. The thermal conductivity is ≥0.85W / m·K, the breakdown field strength is ≥32kV / mm, and the mass change rate after immersion in hydraulic oil at 70℃ for 168h is ≤±0.8%. It combines high thermal conductivity, excellent insulation, oil resistance and mechanical strength.

[0028] The silver nanowire / graphene hybrid shielding layer 5 and the elastic buffer substrate 51 are composed of: 70wt% vinyl silicone rubber, 20wt% conductive carbon black N550, 1wt% silver nanowires (30nm, aspect ratio ≥150), and monolayer graphene (monolayer ratio ≥98%, 1wt%); the elastic buffer substrate 51 is a silicone rubber microfoamed layer (density 0.4g / cm³). 3 ); Structural parameters: The silver nanowire / graphene hybrid shielding layer 5 is constructed using 3D printing to create a mesh structure (pore size 1mm, line width 50μm) with a thickness of 0.1~0.2mm; the elastic buffer substrate 51 has a thickness of 0.05~0.1mm and is located between the nano-boron nitride modified silicone rubber insulating layer 4 and the silver nanowire / graphene hybrid shielding layer 5, seamlessly bonded to both layers; Functional advantages: Silver nanowires and graphene form a "one-dimensional-two-dimensional" highly conductive network, with a shielding effectiveness of ≥88dB in the 30~1000MHz frequency band, attenuation of ≤1dB after 10 million bends, and volume resistivity of ≤5Ω·cm; the elastic buffer substrate 51 absorbs the impact force during dynamic bending, preventing the silver nanowire / graphene hybrid shielding layer 5 from being damaged due to rigid contact, improving the durability of the silver nanowire / graphene hybrid shielding layer 5, and enhancing the interlayer bonding force.

[0029] The inner flexible silicone rubber sheath 6, hardness transition layer 8, and aramid fiber reinforced silicone rubber outer sheath 7 are composed of: inner flexible silicone rubber sheath 6 (85wt% vinyl silicone rubber, 5wt% polyether silicone oil, 8wt% silica, 0.8wt% vulcanizing agent, and 0.2wt% antioxidant 1010); hardness transition layer 8 (blended and modified from vinyl silicone rubber and polyether silicone oil); and aramid fiber reinforced silicone rubber outer sheath 7 (70wt% vinyl silicone rubber, 15wt% KH560 modified aramid fiber, 12wt% silica, 0.8wt% vulcanizing agent, and 2.2wt% oil-resistant additive). Structural parameters: Inner flexible silicone rubber sheath 6, thickness 0.5~1.0mm, Shore A60 hardness; Hardness transition layer 8, thickness 0.2~0.3mm, Shore A65 hardness; Aramid fiber reinforced silicone rubber outer sheath 7, thickness 0.8~1.5mm, Shore A70 hardness, with anti-slip texture 71 on the outer surface (tooth height 0.1mm, tooth pitch 1mm); Functional advantages: The three-layer sheath achieves a gradient hardness transition from 60 to 65 to 70, eliminating stress concentration between layers caused by sudden changes in hardness and preventing cracking between sheath layers during dynamic bending; the inner layer's high flexibility ensures the overall flexibility of the cable, with a dynamic bending radius ≤ 3 × cable outer diameter; the outer layer has high hardness and high tear strength, withstanding 15 million bends without cracking, and a scratch resistance rating ≥ 4, making it suitable for robot mechanical contact and oily conditions; the anti-slip texture 71 increases the friction between the cable and the wiring clamp, preventing loosening.

[0030] The preparation method is as follows: First, the core material is prefabricated, which includes the following steps: (1) Preparation of NiTi alloy-aramid intelligent tensile core 1 Raw material preparation: NiTi alloy wire (diameter 0.1mm, phase transformation temperature 40℃, tensile strength ≥1500MPa), aramid fiber (monofilament diameter 12μm, monofilament strength 3.5GPa), silicone rubber binder (vinyl silicone rubber 95wt% + vulcanizing agent bis2, 50.8wt% + silica 4.2wt%), ethanol (99.5%), silane coupling agent KH550, graphene-based flexible strain sensing module 11; Pretreatment: NiTi alloy wire was wiped with ethanol to remove the oxide layer and air-dried at room temperature; aramid fiber bundles (1000 denier) were soaked in 5wt% KH550 ethanol solution for 30 min and dried at 80℃ for 2 h. Weaving and forming: 16-spindle braiding machine (weaving pitch ratio 8, angle 45°), NiTi alloy wire and aramid fiber are braided at a mass ratio of 1:3, rotation speed 100r / min, traction speed 5m / min, to produce core blanks with a diameter of 1.0~2.0mm; Bonding and vulcanization: The core blank is coated with a 0.05mm thick silicone rubber adhesive through a coating mold, preheated at 120℃ for 5min → vulcanized at 170℃ for 10min → naturally cooled; Sensing module packaging: The graphene-based flexible strain sensing module 11 is attached to the outer surface of the vulcanized NiTi alloy-aramid intelligent tensile core 1 and encapsulated with heat-resistant silicone rubber with a thickness of 0.03~0.05mm. After calibration, it is connected to the robot control system signal. Finally, the tensile strength of the NiTi alloy-aramid intelligent tensile core 1 is ≥1800N.

[0031] (2) Preparation of gradient foamed silicone rubber filler 2 Raw material preparation: Methyl vinyl silicone rubber (MVQ, Shore A50), azodicarbonamide AC foaming agent, bis(2,5) vulcanizing agent, silica (specific surface area 150m²). 2 / g); Grouped formulations (by MVQ mass): Inner layer: MVQ 100 phr + AC 0.5 phr + silica 10 phr + vulcanizing agent 0.8 phr; Middle layer: MVQ 100 phr + AC 1.0 phr + silica 10 phr + vulcanizing agent 0.8 phr; Outer layer: MVQ 100 phr + AC 1.5 phr + silica 10 phr + vulcanizing agent 0.8 phr; Rubber premixing: Each group of raw materials is mixed at 80℃ for 15 minutes (50 r / min), passed through a two-roll mill 3 times, and cured at room temperature for 24 hours to control the foaming pores to be closed-cell structure; Layered vulcanization: A release agent is applied to the inner wall of the cylindrical mold. Materials are added and compacted in layers, "inner-middle-outer." The inner layer has foam pores with a diameter of 15-20 μm, the middle layer 10-15 μm, and the outer layer 5-10 μm. Vulcanization is performed using a stepped temperature increase (120℃×5min→150℃×5min→180℃×5min). After demolding, the material is trimmed to achieve a density of 0.3→0.5→0.7 g / cm³. 3 Density gradient.

[0032] (3) Preparation of nano-boron nitride modified insulating adhesive (used for molding nano-boron nitride modified silicone rubber insulating layer 4) Raw material preparation: PMVQ (phenyl content 15%), FMVQ (trifluoropropyl content 30%), hydroxyl silicone oil (500 mPa·s), KH550 modified boron nitride nanosheets (50 nm), fumed silica (200 nm) 2 / g), vulcanizing agent bis 2,5, nano silica coupling modifier 41; Multi-step mixing: PMVQ and FMVQ are mixed at 80℃ for 15 min (60 r / min); boron nitride nanosheets and nano silica coupling modifier 41 are added and mixed at 80℃ at low speed (40 r / min) for 20 min; silica and sulfiding agent are added and mixed at 90℃ for 10 min; the mixture is passed through a two-roll mill 3 times and matured at room temperature for 24 h, with the viscosity controlled at 100~150 Pa·s.

[0033] (4) Preparation of silver nanowire / graphene hybrid shielding adhesive + elastic buffer substrate adhesive (used to form silver nanowire / graphene hybrid shielding layer 5 and elastic buffer substrate 51, respectively) Preparation of raw materials for hybrid shielding adhesive: vinyl silicone rubber (MVQ, vinyl content 0.2%), conductive carbon black N550, silver nanowires (30nm×≥4.5μm, aspect ratio ≥150), monolayer graphene (1~5μm, monolayer ratio ≥98%), KH550; Multiphase dispersion of hybrid shielding adhesive: MVQ and conductive carbon black were mixed at 70℃ for 15 min (50 r / min); silver nanowires, graphene, KH550 and 10 wt% anhydrous ethanol were added, and ultrasonically dispersed at 300 W for 30 min (stirring at 300 r / min); dried at 80℃ for 2 h to remove solvent, passed through a two-roll mill twice, and matured at room temperature for 12 h. Preparation of elastic cushioning base rubber: 100 phr of methyl vinyl silicone rubber + 0.8 phr of AC foaming agent + 8 phr of silica + 0.8 phr of vulcanizing agent, intensively mixed at 75℃ for 10 min, passed through a two-roll mill twice, cured at room temperature for 24 h, and the density was controlled at 0.4 g / cm³. 3 .

[0034] (5) Preparation of inner layer flexible sheath adhesive + hardness transition layer adhesive + outer layer reinforcing sheath adhesive (used respectively for molding inner layer flexible silicone rubber sheath 6, hardness transition layer 8, and aramid fiber reinforced silicone rubber outer sheath 7) Inner layer flexible silicone rubber sheath: prepared according to the original formula, with Shore hardness controlled at A60±2; Hardness transition layer rubber: 100 phr vinyl silicone rubber + 3 wt% polyether silicone oil + 9 wt% silica + 0.8 wt% vulcanizing agent, 75℃ internal mixing for 15 min, thin pass through a two-roll mill 3 times, room temperature curing for 24 h, Shore hardness controlled at A65±1. Aramid fiber reinforced silicone rubber outer sheath: prepared according to the original formula, Mooney viscosity 80~100ML (1+4) 100℃.

[0035] (6) Preparation of Nano Thermal Grease 31 Raw material preparation: Silicone oil base (thermal conductivity 0.8W / m·K), nano alumina (50nm), and nano boron nitride (20nm) are mixed at 70wt% silicone oil base + 20wt% nano alumina + 10wt% nano boron nitride and ultrasonically dispersed at 300W for 20min to obtain nano thermal conductive silicone grease 31 with thermal conductivity ≥2.0W / m·K.

[0036] Then, the overall cable is fabricated, and the overall cable fabrication process is as follows: (1) Conductor preparation: 0.08mm ultrafine oxygen-free copper wire is bundled into 25~30 strands / bundle using a bundling machine. During the bundling process, nano thermal conductive silicone grease 31 is filled simultaneously. Then, the wires are bundled into a power core (2~4 cores), a control core (8~24 cores), and a signal core (2 cores) using a stranding machine. The control core has a cross-section of 0.12~0.5mm. 2 The signal core cross-section is 0.12mm. 2 ; (2) Coating of nano boron nitride modified silicone rubber insulation layer 4: Single screw extruder (feeding section 100℃, compression section 120℃, homogenization section 130℃, die head 135℃), extruding nano boron nitride modified insulating rubber to coat the outside of ultra-fine copper wire stranded conductor 3 with a thickness of 0.3~0.8mm, traction speed 8m / min, water cooling tank (25℃) for rapid shaping; (3) Plasma etching of nano-boron nitride modified silicone rubber insulating layer 4: The outer surface of nano-boron nitride modified silicone rubber insulating layer 4 is subjected to argon atmosphere plasma etching with a power of 100~150W, an etching time of 5~8min, and an etching depth of 5~10μm to improve the surface roughness of nano-boron nitride modified silicone rubber insulating layer 4 and enhance the bonding force with subsequent layers. (4) Coating of elastic buffer substrate 51: The elastic buffer substrate adhesive is coated on the outer surface of the etched nano boron nitride modified silicone rubber insulation layer 4 using a micro-gravure coating method. The coating speed is 8~10m / min. After pre-baking at 100℃ for 5min, the thickness is 0.05~0.1mm. (5) Forming of silver nanowire / graphene hybrid shielding layer 5: FDM 3D printer (0.2mm nozzle, 130℃ heating, 5mm / s speed) to print a mesh structure (1mm aperture, 50μm line width, 0.1~0.2mm thickness) on the surface of elastic buffer substrate 51, and preheat at 120℃ for 5min for initial curing. (6) Cable core bundling: NiTi alloy-aramid intelligent tensile core 1 is fixed in the center of the cable forming machine. The insulated shielded core wires are stranded in layers with a pitch ratio of ≤8 and short pitch. The gaps are filled with gradient foamed silicone rubber filler 2 with a filling density of ≥95% to ensure the cable core is round. (7) Three-layer co-extrusion: The three-layer co-extrusion machine simultaneously extrudes the inner flexible sheath 6, the hardness transition layer 8, and the outer reinforcing sheath 7. Inner material cylinder: feeding section 90℃, compression section 110℃, homogenization section 120℃, die head 125℃; Transition layer material cylinder: feeding section 95℃, compression section 115℃, homogenization section 125℃, die head 130℃; Outer material cylinder: feeding section 100℃, compression section 120℃, homogenization section 130℃, die head 135℃; The traction speed is 6m / min. The outer sheath 7 of aramid fiber reinforced silicone rubber is formed with anti-slip pattern 71 by a serrated mold (tooth height 0.1mm, tooth pitch 1mm). (8) Ultraviolet light-heat segmented temperature-controlled dual vulcanization: UV pre-curing: UV LED curing machine (365nm, 50mW / cm) 2 Transmission speed 10m / min, irradiation 30s, pre-vulcanization insulation section temperature 80~90℃, insulation 10s, surface cross-linking rate ≥45%; Hot deep vulcanization: hot air tunnel, uniform temperature section 170~180℃, vulcanization 30s, overall crosslinking rate ≥93%; (9) Water-cooled shaping: Cooled to room temperature in a 25℃ water-cooling bath; (10) Post-processing: Remove burrs at both ends with a grinding wheel dresser, perform secondary calibration on the flexible strain sensing module 11, sample and test key performance, and after passing the test, wind and package it according to the winding diameter ≥30× cable outer diameter, and store it in an environment of 15~30℃ and relative humidity ≤60%.

[0037] Example 1, structural parameters: 3 power cores (2.5mm) 2 ), control chip 16-core (0.2mm) 2), signal core 2 cores (0.12mm 2 The cable has an outer diameter of φ12mm; the NiTi alloy-aramid intelligent tensile core 1 has a diameter of 1.5mm, and the flexible strain sensing module 11 is attached to the outer surface of the NiTi alloy-aramid intelligent tensile core 1; the gradient foamed silicone rubber filler 2 has a total thickness of 1.2mm and an inner layer thickness of 0.3g / cm². 3 Middle layer 0.5g / cm 3 Outer layer 0.7g / cm 3 The gaps between the strands of the ultra-fine copper wire stranded conductor 3 are filled with nano-thermal conductive silicone grease 31; the nano-boron nitride modified silicone rubber insulation layer 4 has a thickness of 0.5 mm and contains nano-silica coupling modifier 41; the elastic buffer substrate 51 has a thickness of 0.08 mm, the silver nanowire / graphene hybrid shielding layer 5 has a thickness of 0.15 mm; the inner flexible silicone rubber sheath 6 has a thickness of 0.8 mm, the hardness transition layer 8 has a thickness of 0.25 mm, the aramid fiber reinforced silicone rubber outer sheath 7 has a thickness of 1.0 mm, and the outer surface is provided with anti-slip texture 71.

[0038] Fabrication process parameters: Conductor 3 bundles twisted 28 strands / bundle; Nano thermally conductive silicone grease 31 with a thermal conductivity of 2.2 W / m·K; Nano boron nitride modified silicone rubber insulating layer 4 with plasma etching power of 120 W, etching time of 6 min, and etching depth of 8 μm; Elastic buffer substrate 51 with a coating speed of 9 m / min; Silver nanowire / graphene hybrid shielding layer 5 with a 3D printed mesh aperture of 1 mm; Three-layer sheath co-extrusion traction speed of 6 m / min; UV light-heat segmented temperature-controlled double vulcanization: UV 365 nm × 30 s + 85℃ holding for 10 s, and deep vulcanization at 175℃ for 30 s; Flexible strain sensing module 11 with a packaging thickness of 0.04 mm.

[0039] Performance test results: .

[0040] The performance of the experimental group of this invention was compared with that of the control group of traditional robot silicone rubber cables. The results are as follows: .

[0041] The comparison results show that the present invention has achieved a leapfrog improvement in thermal conductivity, shielding durability, strain response and monitoring, bending fatigue life, and interlayer bonding force, and has completely solved the technical bottlenecks of traditional robot cables.

[0042] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable, characterized in that, From the inside out, the structure includes a NiTi alloy-aramid intelligent tensile core (1), a gradient foamed silicone rubber filler (2), an ultra-fine copper wire stranded conductor (3), a nano-boron nitride modified silicone rubber insulation layer (4), a silver nanowire / graphene hybrid shielding layer (5), an inner flexible silicone rubber sheath (6), and an aramid fiber reinforced silicone rubber outer sheath (7). The surface of the NiTi alloy-aramid intelligent tensile core (1) is integrated with a flexible strain sensing module (11), which is connected to the robot control system. An elastic buffer substrate (51) is provided between the silver nanowire / graphene hybrid shielding layer (5) and the nano-boron nitride modified silicone rubber insulation layer (4). A hardness transition layer (8) is provided between the inner flexible silicone rubber sheath (6) and the aramid fiber reinforced silicone rubber outer sheath (7).

2. The robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable according to claim 1, characterized in that, The NiTi alloy-aramid intelligent tensile core (1) is woven from NiTi alloy wire and aramid fiber in a mass ratio of 1:3, coated with a 0.05mm thick silicone rubber bonding layer, with a diameter of 1.0~2.0mm and a tensile strength ≥1800N; the flexible strain sensing module (11) is a graphene-based flexible thin film sensor, attached to the outer surface of the NiTi alloy-aramid intelligent tensile core (1), with a detection accuracy of ±0.1% strain and an operating temperature of -40~120℃.

3. The robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable according to claim 1, characterized in that, The gradient foamed silicone rubber filler (2) has a three-layer density gradient structure, with the inner layer having a density of 0.3 g / cm³. 3 Middle layer 0.5g / cm 3 Outer layer 0.7g / cm 3 The filling density is ≥95%, the total thickness is 0.8~1.5mm, the compression set is ≤15%, and the energy absorption rate is ≥60%. The gradient foamed silicone rubber filler (2) has a closed-cell structure with a pore size of 5~20μm, and the outer layer foam pore size is smaller than that of the inner layer.

4. The robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable according to claim 1, characterized in that, The ultra-fine copper wire stranded conductor (3) is made of 0.08mm ultra-fine oxygen-free copper wire stranded together, with a copper wire purity ≥99.99%. After stranding 25~30 wires / bundle, it is divided into power core, control core and signal core. The stranding gap of the ultra-fine copper wire stranded conductor (3) is filled with nano thermal conductive silicone grease (31), and the thermal conductivity of the nano thermal conductive silicone grease (31) is ≥2.0W / m·K.

5. The robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable according to claim 1, characterized in that, The nano-boron nitride modified silicone rubber insulation layer (4) is composed of 70wt% phenyl silicone rubber + 30wt% trifluoropropyl silicone rubber + 3wt% hydroxyl silicone oil + 1wt% KH550 modified boron nitride nanosheets + 15wt% silica + 2,50.8wt% vulcanizing agent, and also contains 0.5wt% nano-silica coupling modifier (41). The thickness is 0.3~0.8mm, the thermal conductivity is ≥0.85W / m·K, and the breakdown field strength is ≥32kV / mm.

6. The robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable according to claim 1, characterized in that, The silver nanowire / graphene hybrid shielding layer (5) is a 3D-printed mesh structure with a pore size of 1 mm, a line width of 50 μm, and a thickness of 0.1~0.2 mm; the elastic buffer substrate (51) is a silicone rubber microfoam layer with a thickness of 0.05~0.1 mm and a density of 0.4 g / cm³. 3 The silver nanowire / graphene hybrid shielding layer (5) has a silver nanowire aspect ratio ≥150, a single-layer graphene monolayer rate ≥98%, and a shielding effectiveness ≥88dB in the 30~1000MHz frequency band.

7. The robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable according to claim 1, characterized in that, The inner flexible silicone rubber sheath (6) has a Shore hardness of A60 and an elongation at break of ≥600%. The outer sheath (7) reinforced with aramid fiber has a Shore hardness of A70 and a tear strength of ≥45kN / m. The outer surface is provided with anti-slip texture (71). The hardness transition layer (8) has a Shore hardness of A65 and a thickness of 0.2~0.3mm. It is made by blending and modifying vinyl silicone rubber and polyether silicone oil to achieve a gradient hardness connection of 60→65→70 for the sheath layer.

8. A method for preparing a robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable as described in any one of claims 1 to 7, characterized in that, The process includes core material prefabrication, conductor preparation, encapsulation of boron nitride-modified silicone rubber insulation layer, molding of silver nanowire / graphene hybrid shielding layer, cable core bundling, double sheath extrusion, UV-thermal segmented temperature-controlled double vulcanization, and post-processing. The UV-thermal segmented temperature-controlled double vulcanization process includes a pre-vulcanization insulation section and a deep vulcanization uniform temperature section. Furthermore, the outer surface of the boron nitride-modified silicone rubber insulation layer is subjected to plasma etching treatment before the silver nanowire / graphene hybrid shielding layer is formed.

9. The method for preparing a robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable according to claim 8, characterized in that, The process parameters for plasma etching are: argon atmosphere, power 100~150W, etching time 5~8min, etching depth 5~10μm; the elastic buffer substrate (51) is coated on the outer surface of the etched nano boron nitride modified silicone rubber insulating layer (4) by micro-gravure coating method, coating speed 8~10m / min, and pre-baked at 100℃ for 5min to form.

10. The method for preparing a robot-specific intelligent high thermal conductivity and fatigue-resistant silicone rubber cable according to claim 8, characterized in that, The ultraviolet light-heat segmented temperature-controlled dual curing process includes: UVLED ultraviolet pre-curing, 365nm wavelength, 50mW / cm². 2 Power, transmission speed 10m / min, irradiation 30s, pre-vulcanization insulation section temperature 80~90℃, insulation 10s, surface crosslinking rate ≥45%; hot air tunnel deep vulcanization, uniform temperature section temperature 170~180℃, vulcanization 30s, overall crosslinking rate ≥93%; the post-processing process also includes calibration and packaging of the flexible strain sensing module (11), the packaging material is heat-resistant silicone rubber, thickness 0.03~0.05mm.

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