High-flexibility anti-interference fireproof cable for robot and preparation method of high-flexibility anti-interference fireproof cable

Abstract

The invention discloses a high-flexibility anti-interference fire-resistant cable for a robot and a preparation method thereof, and belongs to the technical field of wires and cables, the cable comprises an insulating wire core, the insulating wire core comprises a conductor, a shielding layer and an insulating layer, the conductor is formed by layering and twisting a plurality of anaerobic copper wires, tensile fibers are arranged in the middle of the conductor, the shielding layer is overlapped and lapped on the surface of the conductor, and the insulating layer is arranged in the shielding layer. A plurality of insulating wire cores and a filling layer are twisted into a cable, a composite belt is arranged on the outer side of the filling layer, the composite belt is made of glass fiber-aerogel, the overlapping rate is 15%-25%, and an inner shielding layer and an outer shielding layer are arranged on the outer side of the composite belt. And the outer side of the outer shielding layer is coated with a sheath layer. According to the invention, the composite belt can form a high-efficiency heat insulation layer in a fire hazard, and heat transfer to the wire core can be obviously delayed. The conductor is formed by stranding a plurality of oxygen-free copper wires in a layered manner, annealing is performed after stranding, and the aramid yarn is embedded in the conductor, so that the tensile stress to the metal conductor can be reduced, and the diameter of the conductor and the outer diameter of the whole cable are reduced while the conductivity and the transmission capability are maintained.

Description

Technical Field

[0001] This invention relates to a highly flexible, interference-resistant, fire-resistant cable for robots and its preparation method, belonging to the field of wire and cable technology. Background Technology

[0002] Robot cables are widely used in industrial automation and intelligent manufacturing, including industrial robot arms, collaborative robots, automated guided vehicles, assembly lines, and palletizing and inspection equipment. These devices frequently twist, bend, and reciprocate during operation, placing extremely high demands on the flexibility, fatigue resistance, and lifespan of the cables. Furthermore, in factory workshops, charging stations, tunnels, or power distribution cabinets, the cables must withstand extreme conditions such as oil contamination, abrasion, moisture, chemical corrosion, and potential high temperatures or open flames. In addition, robot systems have high requirements for signal stability and electromagnetic compatibility (EMC), requiring power and signal lines to transmit reliably and without interference in confined spaces. The cable's ability to maintain power transmission in the event of a fire, with low smoke, low toxicity, and fire resistance, is also a crucial indicator.

[0003] Existing technologies for cables used in mobile robots mainly focus on improvements in flexible conductors, shielding structures, insulation and sheathing materials, and fire-resistant and heat-insulating layers. However, significant shortcomings remain in practical applications: the use of metal sheaths or heavy heat-insulating materials to improve fire resistance or mechanical strength significantly increases the cable's rigidity, weight, and outer diameter, reduces bending flexibility, and shortens fatigue life under continuous robot movement; some fire-resistant treatments rely on halogen-containing or high-smoke-density materials, and the toxic gases and dense smoke generated during a fire are detrimental to personnel safety and the environment; a single shielding layer often struggles to simultaneously achieve efficient EMI suppression and termination reliability, and the terminal stripping and shielding grounding processes are complex, making on-site maintenance difficult.

[0004] In summary, there is a need to design a highly flexible, anti-interference, fire-resistant cable for robots and its preparation method to solve the problems of insufficient flexibility, insufficient fire resistance, excessive outer diameter, excessive weight, and insufficient anti-interference ability of traditional robot cables. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a highly flexible, anti-interference, fire-resistant cable for robots and its preparation method, which solves the problems of insufficient flexibility, insufficient fire resistance, large outer diameter, heavy weight, and insufficient anti-interference ability of traditional cables.

[0006] The technical problem to be solved by this invention is achieved by the following technical solution: a highly flexible, anti-interference, fire-resistant cable for robots, comprising... Insulated wire core, the insulated wire core being capable of transmitting electricity. The insulated core comprises, from the inside out, a conductor, a shielding layer, and an insulation layer. The conductor is formed by stranding multiple oxygen-free copper wires in layers, and tensile fibers are disposed in the middle of the conductor. The shielding layer is a semi-conductive non-woven fabric that is overlapped and wrapped around the surface of the conductor. The insulation layer is made of polyolefin and is disposed on the outside of the shielding layer by extrusion. Multiple insulated wire cores and a filler layer are twisted together to form a cable, with tensile-strength central elements embedded in the gaps between the strands. A composite tape, made of glass fiber aerogel, is provided on the outer side of the filler layer, with an overlap rate of 15%-25%. The outer side of the composite strip is provided with an inner shielding layer and an outer shielding layer in sequence. The inner shielding layer is an aluminum-plastic strip, and the outer shielding layer is a tin-plated copper wire. The outer side of the outer shielding layer is covered with a sheath layer, which is made of polyolefin.

[0007] Preferably, the tensile fiber is made of aramid yarn.

[0008] Preferably, the conductors are annealed after stranding.

[0009] Preferably, the shielding layer is made of semi-conductive non-woven fabric with a thickness of 0.05-0.07 mm, and the overlap rate of the shielding layer is 10%-15%.

[0010] Preferably, the tensile central element comprises an aramid yarn bundle.

[0011] Preferably, the tin-plated copper wire is disposed on the outer side of the aluminum-plastic composite strip, the braiding density of the tin-plated copper wire is 80%-85%, the braiding angle is 40°-45°, and the tin-plated copper wire is grounded.

[0012] Preferably, the surface of the sheath layer is provided with a textured surface.

[0013] A method for preparing a highly flexible, interference-resistant, fire-resistant cable for robots, preferably, The steps are as follows: Step 1: Set up aramid yarn, and twist multiple oxygen-free copper wires on the outside of the aramid yarn. After twisting, perform annealing treatment. Step 2: Wrap the semi-conductive non-woven fabric around the outside of the conductor; Step 3: Extruding the insulating layer; Step 4: Twist the multiple insulated wire cores and the filler layer into a cable, and embed the tensile center element in the gap of the cable; Step 5: Wrap the composite tape around the outside of the filling layer; Step 6: The aluminum-plastic strip is wrapped around the outside of the composite strip; Step 7: The tin-plated copper wire is woven into the outer side of the aluminum-plastic strip; Step 8: The sheath layer is extruded onto the outer side of the tin-plated copper wire; Step 9: After cooling and shaping in a cooling water tank and performing quality inspections such as outer diameter, appearance and electrical continuity using online monitoring equipment, the coil is rolled into a reel.

[0014] The beneficial effects of this invention are: This invention utilizes a conductor made of multiple oxygen-free copper wires stranded in layers. After stranding, the wires are annealed, and aramid yarn is embedded within the conductor. This significantly improves the conductor's flexibility and resistance to bending fatigue. The aramid yarn bears the axial tensile force, reducing tensile stress on the metal conductor. While maintaining conductivity and transmission capacity, the conductor diameter and overall cable outer diameter are reduced. A composite tape composed of glass fiber and aerogel, with an overlap of 15%–25%, serves as a crucial fire-resistant layer. In a fire, this layer forms a highly efficient heat insulation layer, significantly delaying heat transfer to the core and addressing insufficient fire resistance. The extremely low thermal conductivity of aerogel avoids the rigidity and increased volume caused by traditional thick insulation layers, thus balancing fire resistance, flexibility, and a small outer diameter. Glass fiber provides mechanical support, enhancing the composite tape's tear resistance and processing toughness, facilitating industrial production.

[0015] This invention utilizes a semi-conductive non-woven fabric as a shielding layer on the outside of the conductor. This shielding layer can uniformly distribute the electric field, suppress partial discharge, improve insulation capacity, and reduce the risk of insulation failure caused by interface discharge. The insulation layer is made of polyolefin through extrusion, providing excellent insulation and flexibility. Polyolefin is a halogen-free, low-smoke material, which can reduce the release of toxic gases during combustion.

[0016] This invention incorporates a filler layer and a central tensile-resistant element in the cable structure, ensuring a round and uniformly distributed cable, reducing outer diameter fluctuations, and guaranteeing a smaller cable diameter after forming. The central aramid bundle bears the tensile force, reducing the tensile force on the conductor, lessening reliance on metal reinforcements, and lowering weight.

[0017] This invention provides an inner shield and an outer shield. The inner shield uses an aluminum-plastic composite tape, while the outer shield uses tin-plated copper wire braid. The aluminum-plastic composite tape provides a continuous metallic shielding surface, improving EMI suppression and preventing penetration leakage. The tin-plated copper wire braid offers flexibility, enhancing electromagnetic interference resistance and facilitating end grounding, thus solving the problems of insufficient anti-interference capability and reliable termination. The sheath layer is located on the outermost side of the cable, and its surface features textured patterns to improve grip and reduce the difficulty of manual handling. Attached Figure Description

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

[0019] In the diagram: 1-Conductor, 2-Shielding layer, 3-Insulation layer, 4-Filling layer, 5-Composite tape, 6-Inner shielding layer, 7-Outer shielding layer, 8-Sheath layer. Detailed Implementation

[0020] To facilitate a clear understanding of the technical means, creative features, objectives, and effects of this invention, the invention will be further described below in conjunction with specific embodiments. Example 1

[0021] like Figure 1 A highly flexible, interference-resistant, fire-resistant cable for robots includes insulated cores capable of transporting electricity.

[0022] In this embodiment, the insulated wire core consists of a conductor 1, a shielding layer 2, and an insulating layer 3 from the inside to the outside.

[0023] In conductor 1, multiple strands of oxygen-free copper wire with a diameter of 0.08-0.10 mm are optimized and layered to form a Class 6 conductor structure. The structure is based on the Class 6 conductor structure in GB / T 3956. In this embodiment, the stranding pitch ratio is 18. During the stranding process, tensile fibers are embedded in the middle of conductor 1. After stranding, the entire cable is annealed. Annealing and cooling ensure the conductor's flexibility and conductivity. The conductor cross-section is circular, suitable for subsequent wrapping and extrusion processes. The tensile fibers are 1000D aramid yarn.

[0024] A shielding layer 2 is provided on the outside of conductor 1. The shielding layer 2 is a layer of semi-conductive non-woven fabric wrapped around the outer periphery of conductor 1. The thickness of the semi-conductive non-woven fabric is 0.05-0.07 mm, and the overlap rate during wrapping is 10%-15%. The wrapping is performed in a spiral manner to ensure the continuity of the coverage. The shielding layer 2 can uniformly distribute the electric field on the conductor surface and reduce partial discharge.

[0025] An insulating layer 3 is provided on the outside of the shielding layer 2. The insulating layer 3 is formed on the outside of the shielding layer 2 by extrusion and is made of polyolefin insulating material. It has good electrical insulation properties, high and low temperature resistance, environmental stress cracking resistance, and good flexibility and elasticity. The cross-section of the insulating layer 3 is nearly circular.

[0026] In this embodiment, multiple insulated wire cores and filler layer 4 are twisted together into a cable on a cabling machine, and filler layer 4 is made of flame-retardant cotton rope. The multiple insulated wire cores are twisted together by a high-speed untwisting cabling machine, and the cabling pitch ratio is 16 times.

[0027] In this embodiment, there are two types of insulated wire cores. One type has fewer copper wires wound around its conductor 1 and a shorter diameter, while the other type has more copper wires wound around its conductor 1 and a longer diameter. The shorter-diameter insulated wire core serves as a signal wire for transmitting signals, while the longer-diameter insulated wire core serves as a power wire for transmitting current. The two shorter-diameter insulated wire cores are twisted together, with a filler layer 4 filling the gap between them. A composite tape 5 is provided on the outer side of the twisted two shorter-diameter insulated wire cores.

[0028] The diameter of the two shorter insulated wire cores twisted together is the same as the diameter of the longer insulated wire core.

[0029] Two longer diameter insulated wire cores are twisted together with two shorter diameter insulated wire cores to form a whole. A filling layer 4 is provided in the gap between the two longer diameter insulated wire cores and the twisted shorter diameter insulated wire cores.

[0030] A tensile-resistant central element is provided at the center of the stranded cable. In this embodiment, the tensile-resistant central element is made of 2000D aramid yarn bundle.

[0031] The stranded cable is fitted with a composite tape 5 on its outer side. The composite tape 5 is made of fiberglass-aerogel and has a thickness of 0.3mm with an overlap rate of 15%-25%. After wrapping, it can be fixed in position by slight heat pressing or a thin adhesive layer. In a fire, the fiberglass-aerogel composite tape, with the low thermal conductivity of the aerogel and the mechanical support of the fiberglass, forms a multi-level heat insulation layer, delaying the transfer of heat to the conductor and also providing mechanical protection.

[0032] An inner shielding layer 6 and an outer shielding layer 7 are sequentially arranged on the outside of the composite strip 5. The inner shielding layer 6 is made of aluminum-plastic composite strip, which provides a continuous metal shielding surface to prevent direct electrochemical contact.

[0033] A tin-plated copper wire is provided on the outside of the inner shielding layer 6, forming the outer shielding layer 7. In this embodiment, 16 / 0.12 mm tin-plated copper wire is used for braiding, with a braiding density of 80%–85% and a braiding angle of 40°–45°. The tin plating treatment improves corrosion resistance and facilitates termination. In this embodiment, the aluminum foil side of the inner shielding layer 6 faces inward, and the outer shielding layer 7 can be grounded. Through the inner shielding layer 6 and the outer shielding layer 7, efficient EMI suppression and a reliable grounding path can be achieved.

[0034] A sheath layer 8 is provided on the outer side of the outer shielding layer 7. The sheath layer 8 is an extruded, highly wear-resistant, highly flexible, halogen-free, low-smoke, flame-retardant TPO sheath material. The thickness of the sheath layer 8 is 1.0 mm. In this embodiment, the outer side of the sheath layer 8 is embossed using a mold to form a textured surface. The textured surface of the sheath layer 8 improves grip and wear resistance, and the sheath material meets the requirements of low smoke, low toxicity, and weather resistance.

[0035] A method for preparing a highly flexible, interference-resistant, fire-resistant cable for robots includes the following steps: Step 1: Place the tensile fiber at the center of the stranding axis, and strand multiple oxygen-free copper wires with a diameter of about 0.08 mm on the outside of the tensile fiber to form a conductor. The stranding pitch ratio is 18. After stranding, the conductor is annealed.

[0036] Step 2: Wrap semi-conductive non-woven fabric around the outside of conductor 1 to form shielding layer 2. The thickness of the semi-conductive non-woven fabric is 0.05-0.07mm, and the overlap rate is 10%-15%. During the wrapping process, control the tension and linear speed to ensure that the shielding layer 2 is wrinkle-free and uniformly covered.

[0037] Step 3: The conductor 1 covered with shielding layer 2 is fed into an extruder to extrude polyolefin insulation layer 3, and then insulation cross-linking is completed through irradiation cross-linking process to form insulated wire core.

[0038] Step 4: Make multiple insulated wire cores, one type of which has a shorter conductor diameter and the other type has a longer diameter.

[0039] Step 5: Twist two shorter diameter insulated wire cores together to form a cable, and place a filling layer 4 in the gap between the cables. Place a composite tape 5 on the outside of the twisted two shorter diameter insulated wire cores.

[0040] Step 6: Twist the shorter diameter insulated core with two other longer diameter insulated cores to form a cable. A filling layer 4 is placed at the gaps in the cable formation. A tensile-strength central element is embedded at the center of the cable. The cable pitch ratio is 16, and the cable tension is controlled to achieve the desired roundness. The tensile-strength central element is a 2000D aramid yarn bundle.

[0041] Step 7: Wrap a glass fiber-aerogel composite tape 5 around the outside of the cable, with an overlap rate of 15%–25%, and fix it by slight hot pressing or bonding.

[0042] Step 8: Wrap an aluminum-plastic tape around the outside of the composite tape 5 as an inner shielding layer 6.

[0043] Step 9: Tin-plated copper wire is braided on the outside of the inner shielding layer 6 to form the outer shielding layer 7, wherein the braiding density is 80%–85% and the braiding angle is 40°–45°.

[0044] Step 10: Extrude halogen-free, low-smoke, flame-retardant polyolefin onto the outer side of the outer shielding layer 7 to form a sheath layer 8. The sheath layer 8 is approximately 1.0 mm thick, and embossing is performed on the surface of the sheath layer as needed to form raised and recessed textures.

[0045] Step 11: After extrusion, the material is cooled and shaped in a cooling water tank, and online testing equipment is used to inspect the outer diameter, appearance, shielding continuity, grounding resistance, insulation resistance, etc. After passing the inspection, the material is rolled into a reel and labeled to record the production parameters for quality traceability.

[0046] The following tests were performed on the cable of this embodiment, and the results are as follows: Flame retardancy: Passes IEC 60332-3 Cat A bundle burning test; smoke density (IEC 61034-2) <200; combustion gas corrosivity (IEC 60754-1) test: pH≥4.3, conductivity≤10 µS / mm.

[0047] Fire resistance: The fire resistance test was conducted at 750 °C for 90 min according to GB / T 19216.21 standard. During the test, the circuit remained intact and the test indicator light remained on.

[0048] Electrical performance: Conductor resistance, insulation withstand voltage, etc., meet the requirements of relevant standards such as GB / T 5013 or IEC 60245.

[0049] Shielding performance: The transfer impedance and shielding attenuation tests meet the EMC requirements of the charging pile.

[0050] Mechanical properties: Tensile strength, flexural life, wear resistance and oil resistance all meet or exceed the requirements of the corresponding industry standards.

[0051] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention, all of which fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A highly flexible, interference-resistant, fire-resistant cable for robots, comprising: Insulated wire core, the insulated wire core being capable of transmitting electricity. Its features are: The insulated core comprises, from the inside out, a conductor, a shielding layer, and an insulation layer. The conductor is formed by stranding multiple oxygen-free copper wires in layers, and tensile fibers are disposed in the middle of the conductor. The shielding layer is a semi-conductive non-woven fabric that is overlapped and wrapped around the surface of the conductor. The insulation layer is made of polyolefin and is disposed on the outside of the shielding layer by extrusion. Multiple insulated wire cores and a filler layer are twisted together to form a cable, with tensile-strength central elements embedded in the gaps between the strands. A composite tape, made of glass fiber aerogel, is provided on the outer side of the filler layer, with an overlap rate of 15%-25%. The outer side of the composite strip is provided with an inner shielding layer and an outer shielding layer in sequence. The inner shielding layer is an aluminum-plastic strip, and the outer shielding layer is a tin-plated copper wire. The outer side of the outer shielding layer is covered with a sheath layer, which is made of polyolefin.

2. The highly flexible, anti-interference, fire-resistant cable for robots according to claim 1, characterized in that: The tensile fiber is made of aramid yarn.

3. The highly flexible, anti-interference, fire-resistant cable for robots according to claim 1, characterized in that: The conductors are annealed after stranding.

4. The highly flexible, anti-interference, fire-resistant cable for robots according to claim 1, characterized in that: The shielding layer is made of semi-conductive non-woven fabric with a thickness of 0.05-0.07 mm, and the overlap rate of the shielding layer is 10%-15%.

5. The highly flexible, anti-interference, fire-resistant cable for robots according to claim 1, characterized in that: The tensile central element comprises an aramid yarn bundle.

6. The highly flexible, anti-interference, fire-resistant cable for robots according to claim 1, characterized in that: The tin-plated copper wire is disposed on the outside of the aluminum-plastic strip. The braiding density of the tin-plated copper wire is 80%-85%, the braiding angle is 40°-45°, and the tin-plated copper wire is grounded.

7. The highly flexible, anti-interference, fire-resistant cable for robots according to claim 1, characterized in that: The surface of the sheath layer is provided with a textured surface.

8. A method for preparing a highly flexible, anti-interference, fire-resistant cable for robots, wherein the method utilizes the highly flexible, anti-interference, fire-resistant cable for robots as described in any one of claims 1-7, characterized in that: The steps are as follows: Step 1: Set up aramid yarn, and twist multiple oxygen-free copper wires on the outside of the aramid yarn. After twisting, perform annealing treatment. Step 2: Wrap the semi-conductive non-woven fabric around the outside of the conductor; Step 3: Extruding the insulating layer; Step 4: Twist the multiple insulated wire cores and the filler layer into a cable, and embed the tensile center element in the gap of the cable; Step 5: Wrap the composite tape around the outside of the filling layer; Step 6: The aluminum-plastic strip is wrapped around the outside of the composite strip; Step 7: The tin-plated copper wire is woven into the outer side of the aluminum-plastic strip; Step 8: The sheath layer is extruded onto the outer side of the tin-plated copper wire; Step 9: After cooling and shaping in a cooling water tank and performing quality inspections such as outer diameter, appearance and electrical continuity using online monitoring equipment, the coil is rolled into a reel.

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