A signal cable for a robot dog

Abstract

This utility model discloses a signal cable for a robotic dog, comprising two pairs of signal wires with different twist pitches. Each signal wire is shielded, and a filler strip is placed between the signal wire pair and the shielding layer. A PTFE wrapping layer is placed outside the shielding layer, and a sheath layer is placed outside the PTFE wrapping layer. Each signal wire pair is formed by twisting two insulated core wires together. Each insulated core wire includes a conductor, which is surrounded by an insulating layer. The conductor is formed by Z-S layered twisting of several conductor monofilaments. This utility model's signal cable for a robotic dog possesses excellent bending life and fatigue resistance, extremely small bending radius, high signal integrity and low loss, excellent mechanical reliability and stability, good environmental adaptability, and is lightweight and space-saving.

Description

Technical Field

[0001] This utility model belongs to the field of signal cables and relates to a signal cable for a robot dog. Background Technology

[0002] Robot dogs, as representatives of advanced bionic robots, are becoming a hot topic in industrial development due to their superior flexibility and autonomy compared to traditional industrial robots. However, manufacturing high-performance intelligent robot dogs faces a key challenge: the motion cables, especially the leg control cables, whose reliability is like the robot dog's "nervous system," directly determining the overall performance and lifespan. Currently, there is no unified standard for robot dog motion cables, and each manufacturer customizes their designs based on the high-performance requirements of their own products, with a level of stringency far exceeding that of ordinary motion cables. The core pain points are: 1. The leg cables must withstand extremely harsh composite stress environments; 2. High-frequency, high-dynamic loads: The gait of robot dogs (walking, running, jumping, turning) requires the leg joints to undergo high-frequency, large-angle reciprocating bending and twisting, far exceeding conventional industrial applications; 3. Limited space: The pursuit of lightweight and compact bionic structures results in narrow cable routing space, forcing extremely small bending radii, exacerbating compression and friction; 4. Multiple stress composite effects: During movement, the cables simultaneously bear the combined effects of tension (gravity, inertia), bending, torsion, compression (space constraints), and frictional wear. Utility Model Content

[0003] Purpose of the utility model: The purpose of this utility model is to provide a signal cable for a robot dog to address the above-mentioned pain points and improve the service life of the cable.

[0004] Technical Solution: This utility model discloses a signal cable for a robot dog, comprising two pairs of signal wires with different twisting pitches. Each signal wire is shielded, and a filler strip is provided between the signal wire pair and the shielding layer. A PTFE wrapping layer is provided outside the shielding layer, and a sheath layer is provided outside the PTFE wrapping layer. Each signal wire pair is formed by twisting two insulated core wires together. Each insulated core wire includes a conductor, and an insulation layer is provided outside the conductor. The conductor is formed by twisting several conductor monofilaments in ZS layered strands.

[0005] Furthermore, the two pairs of signal lines adopt 6 times the twisted outer diameter and 8 times the twisted outer diameter, respectively.

[0006] Furthermore, the conductor is filled with Kevlar fiber at its center, and the outer layer is composed of four layers of conductor monofilaments twisted together using a ZSZS untwisting twisting method.

[0007] Furthermore, the pitch of the first layer of conductor filaments is 5 times the stranded outer diameter, and the pitch of each of the remaining three layers of conductor filaments is 1.414 times that of the previous layer.

[0008] Furthermore, the filler strip is made of a mixture of cotton thread and Kevlar. The filler strip increases the roundness of the cable, improves tensile strength, and provides cushioning against torsion and bending.

[0009] Furthermore, the insulation layer is made of an alloy of ETFE and fluororubber. This material provides a wide temperature range, high insulation, corrosion resistance, and an MIT flexural strength >100,000 cycles, far exceeding standard levels.

[0010] Furthermore, the shielding layer is made of tin-plated copper foil wire with a single strand of 0.10mm, wrapped with 50D nylon wire.

[0011] Furthermore, the sheath layer is made of polyether PU through double-layer extrusion, and the overall thickness of the sheath layer is 0.50±0.10mm. It has the advantages of wear resistance, scratch resistance, and resistance to mechanical damage.

[0012] Beneficial Effects: Compared with existing technologies, the signal cable for robot dogs of this invention possesses superior bending life and fatigue resistance, excellent dynamic performance (extremely small bending radius), high signal integrity and low loss, outstanding mechanical reliability and stability, good environmental adaptability, lightweight design, and space saving. Through ZS layered stranding of the conductor combined with independent untwisting stranding, internal stress is effectively released, achieving mechanical balance, significantly reducing the fatigue rate of the metal lattice, and increasing service life by 5-10 times. The torque generated by ZS stranding is in the opposite direction, achieving near-zero net torque, and the reduction in overall wire diameter reduces the minimum dynamic bending radius to 4 times the overall outer diameter (compared to 8-10 times for traditional structures).

[0013] The shielding layer uses tinned copper foil wire wrapped around nylon filaments. When bent, it generates only minor internal stress, making it less prone to breakage from repeated bending. Furthermore, the copper foil wire shielding structure reduces weight by 30% to 50% while maintaining the same shielding effectiveness, effectively reducing the cable's outer diameter. A PTFE wrapping layer is placed between the shielding layer and the sheath layer. Its extremely low coefficient of friction reduces friction between the shielding layer and the sheath, improving wear resistance and strength. Moreover, the PTFE wrapping layer is virtually non-absorbent, effectively protecting the internal structure in humid environments. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is a schematic diagram of the conductor structure of this utility model. Detailed Implementation

[0016] The technical solution of this utility model will be further described below with reference to the accompanying drawings.

[0017] like Figure 1-2 As shown, a signal cable for a robot dog in this embodiment includes two pairs of signal wires 3. The two pairs of signal wires 3 adopt different twisting pitches. A shielding layer 5 is provided outside the signal wires 3. A filler strip 4 is provided in the gap between the signal wires 3 and the shielding layer 5. A PTFE wrapping layer 6 is provided outside the shielding layer 5. A sheath layer 7 is provided outside the PTFE wrapping layer 6. The signal wires 3 are formed by twisting two insulated core wires. The insulated core wire includes a conductor 1. An insulation layer 2 is provided outside the conductor 1. The conductor 1 is formed by twisting several conductor monofilaments in ZS layered strands.

[0018] In one embodiment, conductor 1 is a Category 6 CuAg 0.10% alloy conductor conforming to GB / T3956 standard, with a silver content of 0.1%. Conductor 1 has a cross-sectional area of ​​0.13 mm² and consists of 65 conductor monofilaments 9 with a diameter of 0.05 mm, with Kevlar fiber 8 filling the center to enhance structural stability. The conductor is divided into four layers, using a Z (7 conductor monofilaments 9 + Kevlar fiber 8) - S (14 conductor monofilaments 9) - Z (19 conductor monofilaments 9) - S (25 conductor monofilaments 9) untwisting stranding method. In terms of stranding technology, the pitch of the first layer of conductor 1 is 5 times the stranded outer diameter, and the pitch of each subsequent layer is 1.414 times that of the previous layer. Each layer is independently untwisted, effectively releasing internal stress and making conductor 1 more rounded and flexible. This stranding method also achieves mechanical balance; when the cable bends, the torsional stress of the inner and outer layers cancels each other out, avoiding unidirectional stress accumulation. Therefore, during repeated bending, the fatigue rate of the metal lattice is significantly reduced, and the conductor's lifespan can be increased by 5-10 times. Furthermore, the torque generated by Z-twisting and S-twisting is in opposite directions. During dynamic motion, the conductor as a whole can maintain near-zero net torque, which allows the minimum dynamic bending radius of the product to be reduced to 4 times the overall outer diameter, while traditional structures typically require 8-10 times. Additionally, conductor 1 is made of CuAg 0.10% alloy material, with a conductivity of up to 96% (pure copper is 100%). While ensuring excellent bending life, the good conductivity ensures the formation of a low-impedance path, thereby effectively reducing energy loss and guaranteeing the strength and stability of signal transmission.

[0019] In one embodiment, the insulating layer 2 is made of an alloy material of ETFE and fluororubber (RFC-ETFE). RFC-ETFE not only retains the bending resistance, wide temperature range, high insulation and corrosion resistance of ETFE, but also reduces the hardness to make it more flexible. Moreover, the MIT bending strength test can be >100,000 times, while ETFE is about 70,000 times.

[0020] Twisted pairs: Twisting the core wires requires untwisting, which minimizes or eliminates the internal torsional stress of the conductor or core itself during the twisting process, thereby improving the electrical performance, mechanical performance, and structural stability of the cable. Simultaneously, using 6 times and 8 times the twisted outer diameter for different pairs, along with different twisting pitches, minimizes crosstalk between pairs and improves overall signal integrity and transmission performance.

[0021] Cable forming: Cable forming uses a de-twist cage stranding machine. The de-twist device makes the pay-off reel rotate synchronously in the opposite direction to counteract the rotation, so that the wire core enters the stranding point with "zero rotation". This actively eliminates the internal stress and geometric deformation of the wire core during the stranding process, thereby improving the electrical performance, structural stability and mechanical reliability of the cable. The filler uses a filler strip 4 made of cotton thread (about 80%) and Kevlar (about 20%). The use of cotton thread and Kevlar not only increases the roundness of the wire, but also improves the tensile strength of the wire and provides effective buffering force for the cable in twisting and bending.

[0022] By using different pitches in the twisting process, crosstalk between wire pairs is minimized, improving signal integrity and transmission performance. The untwisting process in each stage (conductor stranding, twisting, and cabling) enhances electrical performance and structural stability.

[0023] The shielding layer 5 is made of 0.10mm tin-plated copper foil wire wrapped with 50D nylon wire in the middle, with a shielding rate of 95% min. It not only effectively reduces the outer diameter, but also the characteristics of copper foil wire make it generate only a small internal stress when the cable is bent, making it less prone to breakage due to repeated bending. Moreover, the weight is reduced by 30% to 50% under the same shielding performance.

[0024] A PTFE wrapping layer 6 is set outside the shielding layer 5 to isolate the semi-finished product from the sheath. The PTFE wrapping has an extremely low coefficient of friction, excellent wear resistance and a flexible texture. It can closely fit the cable surface and adapt to the high-frequency bending movement of the cable. Moreover, the PTFE wrapping hardly absorbs water, which can effectively protect the internal structure in humid environments.

[0025] The PTFE wrapping layer 6 is surrounded by a sheath layer 7. The sheath layer 7 is made of polyether PU material and is produced by double-layer extrusion to ensure a round appearance and reduce wire diameter. It includes an inner layer 71 and an outer layer 72, with an overall thickness of about 0.50mm. This material is wear-resistant, scratch-resistant, and has excellent performance in resisting mechanical damage. At the same time, due to the isolation between the PTFE wrapping layer 6 and the sheath layer 7, the extremely low coefficient of friction isolates the friction between the shielding layer 5 and the sheath layer 7 during cable movement, improving the wear resistance and strength of the wire.

Claims

1. A signal cable for a robot dog, characterized in that, It includes two pairs of signal wires with different twist pitches. Each signal wire has an external shielding layer, and a filler strip is provided between the signal wire pair and the shielding layer. A PTFE wrapping layer is provided outside the shielding layer, and a sheath layer is provided outside the PTFE wrapping layer. Each signal wire pair is formed by twisting two insulated core wires. Each insulated core wire includes a conductor, and an insulation layer is provided outside the conductor. The conductor is formed by twisting several conductor monofilaments in ZS layers.

2. The signal cable for a robot dog according to claim 1, characterized in that, The two pairs of signal lines use 6 times the outer diameter of the twisted pair and 8 times the outer diameter of the twisted pair, respectively.

3. The signal cable for a robot dog according to claim 1, characterized in that, The conductor is filled with Kevlar fiber in the center, and the outer layer is composed of several conductor monofilaments divided into four layers and twisted together using a ZSZS untwisting twisting method.

4. The signal cable for a robot dog according to claim 3, characterized in that, The pitch of the first layer of conductor filaments is 5 times the stranded outer diameter, and the pitch of each of the remaining three layers of conductor filaments is 1.414 times that of the previous layer.

5. The signal cable for a robot dog according to claim 1, characterized in that, The filling strip is made of a mixture of cotton thread and Kevlar.

6. The signal cable for a robot dog according to claim 1, characterized in that, The insulating layer is made of an alloy of ETFE and fluororubber.

7. The signal cable for a robot dog according to claim 1, characterized in that, The shielding layer is made of tin-plated copper foil wire with a single strand of 0.10mm diameter wrapped with 50D nylon wire.

8. The signal cable for a robot dog according to claim 1, characterized in that, The sheath layer is made of polyether PU double-layer extrusion, and the overall thickness of the sheath layer is 0.50±0.10mm.

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