Dynamic bending self-adaptive flexible connection electrophoresis insulation process

Abstract

The invention discloses a dynamic bending self-adaptive flexible connection electrophoresis insulation process, and belongs to the technical field of electrical insulation. According to the process, a miniature strain gauge is embedded in the surface of an electrical flexible connection main body, the dynamic bending strain is detected in real time, and the current bending curvature radius is calculated; the control unit dynamically adjusts the electric field intensity of the electrophoresis system according to a preset curvature-electric field mapping relation; the flexible connection main body is arranged in epoxy-silicon dioxide sol, the sol is directionally deposited under the action of an electric field to form an insulating layer, and the thickness of the insulating layer is dynamically adjusted along with the bending curvature radius and is in a negative correlation relationship. Self-adaptive distribution of the thickness of the insulating layer is achieved, the thickness is increased in a violent bending area to resist tensile stress, the thickness is reduced in a smooth area to maintain flexibility, and the insulation reliability and mechanical durability of flexible connection under the dynamic working condition are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of electrical insulation technology, specifically to a dynamic bending adaptive flexible connection electrophoretic insulation process. Background Technology

[0002] Currently, the mainstream insulation treatment methods for flexible connectors mainly include integral injection molding / compression insulation, coating with insulating varnish, and using insulating heat shrink tubing. However, these traditional processes have limitations: First, the thickness of the resulting insulation layer is usually uniform and fixed, making it impossible to optimize according to the bending curvature of the connector during actual operation. During dynamic bending, the insulation layer on the outer side of the bend, where the radius of curvature is smaller, bears greater tensile stress, which can easily lead to cracking or even peeling of the insulation layer; while in areas with a larger radius of curvature, a thicker insulation layer may affect flexibility and generate unnecessary stress due to material accumulation. Second, the above processes are mostly offline and static, making it impossible to achieve real-time control of the insulation layer deposition process, and it is difficult to balance insulation performance and mechanical flexibility.

[0003] Electrophoretic deposition, a technique capable of forming uniform, dense coatings on complex surfaces, has been explored for application in conductor insulation. However, existing electrophoretic insulation process parameters are typically kept constant throughout a single process flow, resulting in coating thickness that is fixedly related to the deposition environment. When applied to dynamic flexible connections under complex operating conditions, this static process cannot respond to the real-time changes in the bending shape of the connector, leading to stress unevenness and durability issues in the deposited insulation layer during subsequent dynamic use, similar to those encountered with traditional processes.

[0004] Therefore, the existing technology lacks an intelligent insulation process that can sense the real-time deformation state of the soft connection online and dynamically adjust the insulation layer deposition parameters accordingly, thereby obtaining an adaptive thickness distribution that can both ensure insulation strength and maximize the relief of bending stress. Summary of the Invention

[0005] The purpose of this invention is to provide a solution to the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a dynamic bending adaptive soft-connection electrophoretic insulation process, comprising the following steps: The main body of the electrical flexible connection is a flexible conductive component made of multiple strands of fine conductors braided or twisted together; Multiple micro-strain gauges are embedded in the surface of the electrical flexible connection body; The surface strain of the flexible connector body under dynamic bending conditions is detected in real time by micro strain gauges, and strain signals are generated. The control unit receives strain signals and calculates the current bending radius of curvature of the electrical flexible connection body based on the strain signals; The control unit dynamically adjusts the electric field strength of the electrophoresis system based on the preset curvature-electric field mapping relationship and the current curvature radius; The flexible electrical connector is placed in an electrophoresis tank containing epoxy-silica sol, and the epoxy-silica sol is directionally migrated and deposited on the surface area of ​​the flexible electrical connector under the action of electric field strength to form an insulating layer. The thickness of the insulating layer is configured to be dynamically adjusted according to the current bending radius of curvature, and the two are negatively correlated.

[0007] Preferably, the negative correlation between the thickness of the insulating layer and the current bending radius specifically satisfies the following conditions: when the current bending radius κ ≤ 2 mm, the thickness of the insulating layer is 12-18 μm; when 2 mm < κ ≤ 5 mm, the thickness of the insulating layer is 4-12 μm; and when κ > 5 mm, the thickness of the insulating layer is 3-7 μm.

[0008] Preferably, the curvature-electric field mapping relationship is as follows: when the current curvature radius κ≤2mm, the electric field strength is 8-12V / cm; when 2mm<κ≤5mm, the electric field strength is 4-6V / cm; when κ>5mm, the electric field strength is 1-3V / cm.

[0009] Preferably, when the current bending radius κ satisfies 2mm < κ ≤ 5mm, the thickness δ of the insulating layer satisfies the relationship between δ and κ: δ = a - bκ, where a and b are constants, and the value of δ falls within the range of 4-12μm.

[0010] Preferably, the micro strain gauges have a size of 0.4-0.6 mm × 0.4-0.6 mm, an embedding depth of 1-3 μm, and are distributed in a grid pattern along the surface of the electrical flexible connection body, with a grid spacing of 0.8-1.2 mm.

[0011] Preferably, the epoxy-silica sol contains silica nanoparticles with a particle size of 40-60 nm and the sol has a pH value of 4.0-5.0 and a temperature of 24-26°C.

[0012] Preferably, after forming the insulating layer, the method further includes: A test voltage of 100-150V is applied to the electrical flexible connection body covered with the insulation layer, and its insulation resistance value is measured. The insulation resistance value is less than 1.0 × 10⁻⁶. 9 If Ω, then repeat the steps of dynamically adjusting the electric field strength and directional deposition to perform secondary deposition; The number of cycles for secondary deposition does not exceed three.

[0013] Preferably, the bottom of the electrophoresis tank is provided with microchannels, the width of which is 0.15-0.25 mm, to accelerate the flow of the epoxy-silica sol and ensure that its flow velocity in the surface area of ​​the electrical flexible connector body is not less than 0.4 m / s.

[0014] Preferably, the control unit obtains the current bending radius of curvature by calculating the curvature of the surface of the electrical flexible connection body based on the strain distribution data of the micro strain gauge.

[0015] Preferably, the electrophoresis system includes a positive electrode and a negative electrode arranged in parallel on both sides of the electrical flexible connection body, the distance between the positive electrode and the negative electrode is 4-6 mm and the electrode material is a platinum-iridium alloy.

[0016] Compared with the prior art, the beneficial effects of the present invention are: by detecting the bending curvature in real time and dynamically adjusting the electric field strength, the thickness of the insulation layer is made to adapt to the curvature in a negatively correlated manner, thereby effectively relieving the tensile stress in the outer region of the bend, preventing the generation of microcracks, and avoiding material redundancy in areas with large curvature, thus improving the flexibility of the soft connection and the reliability of insulation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the process flow according to an embodiment of the present invention. Detailed Implementation

[0018] 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.

[0019] Please see Figure 1 A dynamic bending adaptive electrophoretic insulation process for flexible connectors is disclosed. This process involves embedding micro-strain gauges on the surface of the flexible connector body to detect surface strain in real time under dynamic bending conditions and generate strain signals. After receiving the strain signals, the control unit calculates the current bending radius of curvature of the flexible connector body and dynamically adjusts the electric field strength of the electrophoresis system according to a preset curvature-electric field mapping relationship. Subsequently, the flexible connector body is placed in an electrophoresis tank containing epoxy-silica sol, allowing the sol to migrate and deposit directionally under the influence of the electric field strength, forming an insulating layer. The thickness of this insulating layer is configured to dynamically adjust with the current bending radius of curvature, and the two are negatively correlated. This effectively solves the problems of uneven stress and durability caused by the inability to adaptively adjust the insulation layer thickness in existing technologies.

[0020] For ease of understanding, the following explains some key terms in this embodiment: Electrical flexible connection body: refers to a flexible conductive component made of multiple strands of fine conductors braided or twisted together. Its main function is to provide a conductive path in electrical connections that need to be bent or moved, and it has good flexibility to adapt to dynamic deformation.

[0021] Miniature strain gauges are tiny sensor devices whose resistance changes with the mechanical strain they are subjected to. By measuring the change in resistance, strain information of an object's surface can be indirectly obtained.

[0022] Strain signal: refers to the electrical signal formed after the mechanical strain information detected by the micro strain gauge is converted. This signal carries data on the current deformation state of the flexible connection body.

[0023] Control unit: refers to a system consisting of one or more processors, memory, and input / output interfaces. It is responsible for receiving and processing strain signals, performing calculations, and outputting control commands to adjust the operating parameters of the electrophoresis system.

[0024] Radius of curvature: This refers to the radius of the circle corresponding to the curve of an object when it is bent. The smaller the radius of curvature, the more severe the bending; the larger the radius of curvature, the gentler the bending.

[0025] Curvature-electric field mapping relationship: refers to a pre-established function or lookup table that correlates the current bending radius of curvature of the flexible connector with the electric field strength required by the electrophoresis system. This relationship guides the control unit on how to adjust the electric field according to the bending state.

[0026] Electrophoresis system: refers to the complete set of equipment used to realize the electrophoretic deposition process. It usually includes an electrophoresis tank, electrodes, power supply and related control equipment. It causes charged particles to migrate in a direction and be deposited by applying an electric field.

[0027] Epoxy-silica sol: refers to a colloidal solution containing epoxy resin precursors and silica particles. Under the influence of an electric field, the charged components in it undergo electrophoresis and deposit on the target surface to form a composite insulating coating.

[0028] Electrophoresis tank: refers to a container used to hold electrophoretic solutions such as epoxy-silica sol and to perform electrophoretic deposition operations. It is usually equipped with electrodes inside.

[0029] Insulating layer: refers to a coating with electrical insulating properties formed on the surface of the main body of the electrical flexible connection through an electrophoretic deposition process. Its function is to prevent current leakage and short circuit, and to ensure electrical safety.

[0030] The dynamic bending adaptive flexible connection electrophoretic insulation process of this embodiment can be implemented as follows: First, an electrical flexible connection body is provided, which can be made of copper wire, aluminum wire, or other conductive materials through a braiding or stranding process. This body is designed as a flexible conductive component, enabling it to adapt to repeated bending and torsion, for example, in robot joints, new energy vehicle battery pack connections, or industrial automation equipment.

[0031] Secondly, multiple micro-strain gauges are embedded on the surface of the electrical flexible connector body. These micro-strain gauges can be fixed to the surface of the electrical flexible connector body using methods such as surface mounting, laser etching, or micro-injection molding. The strain gauges are arranged on the flexible connector body to capture its deformation information under different bending states. For example, the strain gauges can be arranged along the longitudinal and transverse directions of the flexible connector body to obtain multi-dimensional strain data.

[0032] Furthermore, micro-strain gauges are used to detect the surface strain of the flexible connector body under dynamic bending conditions in real time and generate strain signals. When the flexible electrical connector body bends, its surface experiences tensile or compressive strain, which causes a change in the resistance value of the embedded micro-strain gauges. The resistance change of the strain gauges is converted into a voltage or current signal using a Wheatstone bridge circuit or similar method, thus generating a strain signal. This process is continuous, ensuring real-time monitoring of dynamic bending conditions.

[0033] Subsequently, the control unit receives strain signals and calculates the current bending radius of curvature of the electrical flexible connector body based on these signals. The control unit can have a built-in microprocessor that receives strain signals from multiple micro-strain gauges. Using a preset algorithm, such as empirical formulas based on material mechanics models or finite element analysis results, these strain signals are converted into the bending curvature of the electrical flexible connector body at a specific location. The bending radius of curvature is calculated by measuring the strain difference between the outer and inner sides of the flexible connector body. The control unit obtains strain values ​​at different locations on the surface of the electrical flexible connector body using multiple embedded micro-strain gauges. For a localized curved region of the main body, assuming its bending deformation conforms to the Euler-Bernoulli beam theory, then the curvature κ of this region is related to the surface strain. There exists an approximately linear relationship: κ = 2 / h, where h is the thickness of the electrical flexible connection body. In actual operation, the control unit selects the readings of two symmetrically arranged strain gauges on the outer side of the bending arc and the inner side under compression, and calculates their strain difference Δε. Then, the current local bending radius of curvature R = h / Δε. For a grid-like distribution of strain gauge arrays, the control unit can perform sliding window calculations on the data of adjacent gauges to obtain a continuous radius of curvature distribution map along the length of the body.

[0034] The control unit dynamically adjusts the electric field strength of the electrophoresis system based on a preset curvature-electric field mapping relationship and the current bending radius. The control unit stores the curvature-electric field mapping relationship internally, which can be a mathematical function, a lookup table, or an artificial intelligence model. After calculating the current bending radius, the control unit queries or calculates the corresponding target electric field strength value. Subsequently, the control unit sends a command to the power module of the electrophoresis system to adjust the voltage or current between the electrodes in the electrophoresis tank in real time, thereby changing the electric field strength. When a decrease in the curvature radius is detected, the control unit instructs the electrophoresis system to increase the electric field strength. The curvature-electric field mapping relationship is determined through joint optimization based on a series of deposition experiments and finite element stress analysis. The specific method is as follows: 1. Basic deposition experiment: Electrophoretic deposition was performed on specimens with different fixed bending radii R under a constant electric field strength E, the final insulation layer thickness δ was measured, and an ER-δ basic database was established.

[0035] 2. Stress Simulation: Using finite element software, the maximum tensile stress of the insulation layer under dynamic bending is simulated under different combinations of R and δ. .

[0036] 3. Mapping optimization: to achieve... With the goal of minimizing the overall thickness of the insulation layer while keeping it below the material's yield strength, the optimal δ range for different R intervals is optimized, and then the corresponding optimal E range is derived from the database of basic deposition experiments, thus forming the aforementioned mapping relationship.

[0037] Next, the flexible electrical connector is placed in an electrophoresis tank containing epoxy-silica sol. Under the influence of an electric field, the epoxy-silica sol migrates directionally and deposits on the surface of the flexible electrical connector, forming an insulating layer. The flexible electrical connector is then immersed in the epoxy-silica sol in the electrophoresis tank as the working electrode. Under the influence of an electric field regulated by a control unit, the charged epoxy resin precursor and silica nanoparticles in the sol undergo electrophoresis, moving directionally towards the surface of the flexible electrical connector. When these charged particles reach the surface, an electrochemical reaction occurs, and they deposit, gradually forming a dense insulating coating.

[0038] The thickness of the insulation layer is dynamically adjusted based on the current bending radius, with a negative correlation between the two. This negative correlation means that when the bending radius of the electrical flexible connection decreases (i.e., the degree of bending increases), the thickness of the deposited insulation layer increases accordingly; conversely, when the bending radius increases (i.e., the degree of bending decreases), the insulation layer thickness decreases accordingly. This dynamic adjustment is achieved by real-time regulation of the electric field strength by a control unit, increasing the local insulation layer thickness by increasing the electric field strength or extending the deposition time.

[0039] This application achieves an adaptive negative correlation between insulation layer thickness and bending radius by real-time sensing of the dynamic bending state of the flexible electrical connector and dynamically adjusting the electric field strength during the electrophoretic deposition process. Thus, in areas of severe bending, the insulation layer is designed to be thicker to effectively resist tensile stress and reduce the risk of cracking; while in areas of gentle bending, the insulation layer is relatively thinner, avoiding the impact of material accumulation on flexibility. This intelligent, online insulation process improves the insulation durability and mechanical flexibility of the flexible connector under dynamic conditions, solving the problems of uneven insulation layer stress and difficulty in achieving both performance and flexibility in traditional processes.

[0040] In some embodiments described above in this application, a negative correlation between the thickness of the insulating layer and the current bending radius of curvature is proposed to dynamically adjust the thickness of the insulating layer to alleviate bending stress. However, in its implementation, the lack of a specific thickness range definition may lead to inaccurate thickness adjustment of the insulating layer under different curvatures, affecting insulation performance and mechanical flexibility.

[0041] In this regard, this application further proposes a negative correlation between the thickness of the insulation layer and the current bending radius of curvature, specifically satisfying the following conditions: when the current bending radius of curvature κ≤2mm, the insulation layer thickness is 12-18μm; when 2mm<κ≤5mm, the insulation layer thickness is 4-12μm; and when κ>5mm, the insulation layer thickness is 3-7μm.

[0042] This technical solution specifies the detailed range of insulation layer thickness values ​​under different bending radii to achieve precise adaptive adjustment of the insulation layer thickness. When the bending radius κ ≤ 2mm, it indicates that the electrical flexible connection body is in an extremely bent state. At this point, the tensile stress on the outer side of the bend is the highest, requiring the highest tensile strength and insulation resistance of the insulation layer. Therefore, the insulation layer thickness is set within a relatively large range of 12-18μm to ensure sufficient insulation protection and mechanical strength under extreme bending conditions, effectively resisting the risk of cracking caused by stress concentration. When 2mm < κ ≤ 5mm, it indicates that the electrical flexible connection body is in a moderately bent state. At this point, the insulation layer needs to balance a certain level of insulation strength and good flexibility. Setting the insulation layer thickness within a moderate range of 4-12μm aims to balance insulation performance and material flexibility, avoiding affecting the overall flexibility of the flexible connection or generating unnecessary stress due to excessive insulation layer thickness. When κ > 5mm, it indicates that the electrical flexible connection body is in a slightly bent or nearly straight state. At this point, the bending stress is relatively small, and the requirement for insulation layer thickness is relatively low. Setting the insulation layer thickness within a narrow range of 3-7 μm can minimize the accumulation of insulation material, improve the flexibility of the flexible connection, and reduce material costs.

[0043] The determination of these thickness ranges can be based on optimization using experimental data such as finite element analysis of material stress distribution under different curvatures, fatigue life tests, and insulation breakdown voltage tests. By analyzing the stress-strain curves of insulation layers of different thicknesses under specific bending curvatures, and combining this with insulation performance requirements, the optimal thickness range can be determined. Another approach is to establish a mathematical model that correlates bending curvature, material properties, and insulation layer thickness, and then use an iterative optimization algorithm to derive a thickness segmentation strategy that meets performance requirements.

[0044] Through the above technical solution, this application provides a specific and segmented numerical definition of the negative correlation between insulation layer thickness and the current bending radius, thereby solving the problem of inaccurate insulation layer thickness adjustment under dynamic bending conditions. This precise thickness segmentation strategy allows the insulation layer to obtain the most suitable thickness in different curvature regions according to the real-time changing bending state of the electrical flexible connection body. Specifically, in areas with small bending radii and stress concentration, a thicker insulation layer can effectively resist tensile stress, prevent insulation layer cracking or peeling, and ensure insulation reliability; while in areas with large bending radii and low stress, a thinner insulation layer can maximize the flexibility of the electrical flexible connection body, avoiding unnecessary material accumulation and stress generation. This adaptive thickness distribution improves the durability and reliability of the insulation layer under dynamic bending conditions, while optimizing the mechanical compliance of the flexible connection, achieving the best balance between insulation performance and mechanical flexibility.

[0045] In some of the embodiments described above in this application, a curvature-electric field mapping relationship is proposed to dynamically adjust the electric field strength. However, in its implementation, the lack of a specific range of electric field strength values ​​may lead to inaccurate adjustment, affecting the optimized deposition of the insulating layer under dynamic bending conditions, and thus failing to ensure that the negative correlation between the insulation layer thickness and the radius of curvature is effectively realized.

[0046] In this regard, this application further proposes the following curvature-electric field mapping relationship: when the current curvature radius κ≤2mm, the electric field strength is 8-12V / cm; when 2mm<κ≤5mm, the electric field strength is 4-6V / cm; when κ>5mm, the electric field strength is 1-3V / cm.

[0047] The aforementioned curvature-electric field mapping relationship is the core mechanism guiding the dynamic adjustment of the electric field intensity during electrophoretic deposition. It correlates the real-time mechanical state of the electrical flexible connector under dynamic bending conditions—the current bending radius of curvature κ—with the electric field intensity required for electrophoretic deposition, thereby achieving adaptive control of the insulation layer thickness. This mapping relationship can be pre-stored in the control unit, for example, in the form of a lookup table or defined through a piecewise function. When the control unit receives the current bending radius of curvature κ, which is detected and calculated in real time by micro-strain gauges, it can determine the corresponding electric field intensity range based on this mapping relationship and instruct the electrophoresis system to apply that electric field intensity.

[0048] Specifically, when the current bending radius κ ≤ 2 mm, the electric field strength is set to 8-12 V / cm. This range corresponds to the region where the electrical flexible connection body undergoes severe bending. In these regions, the insulation layer will be subjected to significant tensile stress. Therefore, a higher electric field strength is required to accelerate the directional migration and deposition of the epoxy-silica sol to ensure the formation of a thick and dense insulation layer in a short time. This rapid deposition under high electric field strength helps to build sufficient insulation thickness in stress concentration areas, thereby effectively resisting the mechanical stress caused by dynamic bending.

[0049] When 2mm < κ ≤ 5mm, the electric field strength is set to 4-6V / cm. This range corresponds to the region where the electrical flexible connection body undergoes moderate bending. In such regions, the mechanical stress on the insulation layer is between severe and slight bending. Therefore, using a moderate electric field ensures effective deposition of the epoxy-silica sol to form the required insulation thickness, while avoiding excessively high electric fields that could lead to excessively rapid deposition, excessive material buildup, and consequently affect the flexibility of the flexible connection or generate unnecessary internal stress.

[0050] When κ > 5 mm, the electric field strength is set to 1-3 V / cm. This range corresponds to areas where the electrical flexible connector body undergoes slight bending or is nearly straight. In these areas, the mechanical stress on the insulating layer is relatively small. Therefore, using a lower electric field strength slows down the deposition rate of the epoxy-silica sol, resulting in a relatively thin insulating layer. This strategy avoids depositing unnecessary thickness in low-stress areas, thereby maximizing the inherent flexibility of the flexible connector and reducing material consumption.

[0051] Through the above technical solution, this application solves the problem of inaccurate electric field strength adjustment by providing a specific numerical range of electric field strength for the curvature-electric field mapping relationship. This precise numerical limitation ensures that the electric field strength can be accurately adjusted according to the real-time radius of curvature κ of the flexible electrical connection under dynamic bending conditions, thereby optimizing the electrophoretic deposition process. Specifically, when the radius of curvature κ is small, the system applies a higher electric field strength to promote rapid deposition of epoxy-silica sol, forming a thicker insulating layer to effectively resist the stretching in high-stress areas; when the radius of curvature κ is large, the system applies a lower electric field strength to slow down the deposition rate, forming a thinner insulating layer to maintain the flexibility of the flexible connection and avoid unnecessary material accumulation. This dynamic and precise electric field strength control allows the thickness of the insulating layer to exhibit a clear negative correlation with the current bending radius of curvature κ, thereby improving the fatigue resistance and durability of the insulating layer under dynamic bending conditions while ensuring insulation performance, effectively avoiding the risk of insulating layer cracking or peeling.

[0052] In some of the embodiments described above in this application, a curvature-electric field mapping relationship is proposed to dynamically adjust the electric field strength and control the insulation layer thickness. However, in its implementation, when the radius of curvature is in the range of 2 mm to 5 mm, the adjustment of the insulation layer thickness lacks a precise mathematical relationship, which may lead to discontinuous or unoptimized thickness changes, affecting the stress relief effect and the stability of the insulation performance.

[0053] In this regard, this application further proposes that in the above process, when the current bending radius κ satisfies 2mm<κ≤5mm, the thickness δ of the insulating layer satisfies the relationship between δ and κ: δ=a-bκ, where a and b are constants, and the value of δ falls within the range of 4-12μm.

[0054] Specifically, the current bending radius κ satisfies 2mm < κ ≤ 5mm, limiting the specific bending conditions to which this linear relationship applies. Within this moderate bending range, the flexible electrical connector experiences non-extreme bending stress, making precise control of the insulation layer thickness crucial to balance its electrical insulation performance with mechanical flexibility. The control unit continuously monitors and calculates the current bending radius of the flexible electrical connector, activating this specific thickness adjustment strategy only when the radius falls between 2mm and 5mm.

[0055] The thickness δ and κ of the insulating layer satisfy the relationship: δ = a - bκ, establishing a linear negative correlation between the insulating layer thickness and the current bending radius of curvature. This means that as the bending radius of curvature increases (i.e., the bending degree decreases), the insulating layer thickness will decrease linearly; conversely, when the bending radius of curvature decreases (i.e., the bending degree increases), the insulating layer thickness will increase linearly. This linear relationship ensures that the insulating layer thickness can be smoothly and continuously adjusted during dynamic changes, avoiding stress concentration that may be caused by abrupt thickness changes. Based on this formula and combined with the real-time detected radius of curvature, the control unit calculates the target insulating layer thickness, thereby guiding the adjustment of the electric field strength of the electrophoresis system.

[0056] Here, a and b are constants, which are key parameters defining the aforementioned linear relationship. Constants a and b can be predetermined through experimental testing, finite element analysis, or optimization algorithms, based on the specific material properties of the electrical flexible connection body, the deposition behavior of the epoxy-silica sol, and the expected insulation and mechanical performance requirements. These constants are optimized by simulating the stress distribution of insulation layers of different thicknesses under different bending curvatures, or through fatigue life testing, to ensure that the insulation layer has optimal stress relief and durability under dynamic operating conditions. Once determined, these constants are stored in the control unit for real-time calculations.

[0057] In the medium curvature range To achieve continuous thickness control, a linear model δ = a - bκ was used. The constants a and b were obtained through linear regression fitting using the basic deposition experimental data. For the materials and sol used in this embodiment, a feasible set of fitted values ​​was: a = 14, b = 2, i.e., δ = 14 - 2κ.

[0058] At this point, when R=3mm, When δ≈13.3μm; when R=5mm, κ=0.2 At that time, δ≈13.6μm. Considering the fluctuations in deposition, this calculated value will fall within the overall control target range of 4-12μm, and can be precisely controlled by fine-tuning the electric field strength.

[0059] The value of δ falls within the range of 4-12 μm, setting clear upper and lower limits for the insulation layer thickness. This range is designed to ensure that the insulation layer, while meeting electrical insulation strength requirements, will not reduce the flexibility of the flexible electrical connection due to excessive thickness, nor cause insulation failure due to excessive thinness. A thickness below 4 μm may not provide sufficient dielectric strength, while a thickness above 12 μm may generate excessive internal stress during bending, affecting the mechanical properties and service life of the flexible connection. Therefore, the selection of constants a and b must ensure that the insulation layer thickness calculated within this curvature range always falls within this defined range.

[0060] Through the above technical solution, this application introduces a linear relationship between the insulation layer thickness δ and κ, satisfying δ=a-bκ, in the dynamic bending adaptive electrophoretic insulation process for flexible connections, specifically addressing the bending radius κ of 2mm<κ≤5mm. This improvement establishes a mechanism for the insulation layer thickness to change continuously and smoothly with the radius of curvature, effectively solving the problem that the lack of precise mathematical relationship for insulation layer thickness adjustment within this moderate bending range may lead to discontinuous or unoptimized thickness changes. Specifically, when the bending degree of the flexible connection body decreases and κ increases, the insulation layer thickness decreases linearly, thereby avoiding unnecessary material accumulation and maintaining the flexibility of the flexible connection; conversely, when the bending degree intensifies and κ decreases, the insulation layer thickness increases linearly, enhancing insulation strength and tensile stress resistance. By setting constants a and b, the thickness change trend can be finely customized according to actual application requirements and material properties, ensuring that the insulation layer is always in the optimal thickness distribution state during dynamic bending. Meanwhile, limiting the insulation layer thickness δ to the range of 4-12μm further ensures that the insulation layer can provide reliable electrical insulation performance and alleviate bending stress to the maximum extent, avoiding insulation failure or reduced flexibility due to excessive thickness or thinness, thereby improving the reliability and service life of the electrical flexible connection under dynamic working conditions.

[0061] In some of the embodiments described above in this application, micro strain gauges are proposed for real-time detection of surface strain of the electrical flexible connection body. However, in the implementation process, if the size of the micro strain gauge is too large, the embedding depth is inappropriate, or the distribution is uneven, it may lead to inaccurate strain detection, affecting the calculation accuracy of the bending radius of curvature, and thus affecting the dynamic adjustment of the insulation layer thickness.

[0062] To address this, this application further proposes optimized parameters and layout of the micro-strain gauges to ensure reliable measurement of surface strain under dynamic bending conditions. Specifically, the micro-strain gauges have dimensions of 0.4-0.6 mm × 0.4-0.6 mm, an embedding depth of 1-3 μm, and are distributed in a grid pattern along the surface of the electrical flexible connection body, with a grid spacing of 0.8-1.2 mm.

[0063] The micro strain gauge is a sensor used to measure the strain on the surface of an object. Its working principle is typically based on the resistive strain effect; that is, when the strain gauge is deformed under stress, its resistance changes, and the strain value can be calculated by measuring the change in resistance. Limiting the size of the micro strain gauge to the range of 0.4-0.6 mm × 0.4-0.6 mm aims to ensure that the strain gauge is small enough not to affect the flexibility and dynamic bending performance of the electrical flexible connection body, while providing sufficient detection area to capture high-precision strain signals. It can be manufactured using semiconductor materials such as silicon through microelectromechanical systems (MEMS) processes to achieve high integration and miniaturization; alternatively, a metal foil strain gauge can be used, with the sensing grid fabricated on a flexible substrate such as polyimide through a precision etching process, and then cut to the required size.

[0064] The embedding depth is 1-3 μm, which ensures that the strain gauge fits tightly against the surface of the electrical flexible connector, accurately reflecting minute strain changes, while avoiding damage to the multi-strand fine conductor braid structure. Specifically, precision machining techniques such as laser etching or micro-milling can be used to form microgrooves on the surface of the electrical flexible connector, then the strain gauge is embedded and encapsulated with insulating adhesive or epoxy resin; alternatively, a strain-sensitive material layer can be directly grown or deposited on the surface of the electrical flexible connector using thin-film deposition techniques such as chemical vapor deposition (CVD) or physical vapor deposition (PVD), and then patterned to form an embedded strain gauge structure.

[0065] The micro-strain gauges are distributed in a grid pattern along the surface of the electrical flexible connector body, aiming to achieve uniform sampling of the strain on the surface of the electrical flexible connector body, covering the entire body surface, eliminating detection blind spots, and improving the comprehensiveness and consistency of strain data. The grid distribution pattern is pre-designed, and during or after the manufacturing process of the electrical flexible connector body, the micro-strain gauges are precisely attached to the preset grid positions using automated mounting equipment; alternatively, a flexible substrate integrated strain gauge array is used, where multiple micro-strain gauges are pre-fabricated on the same flexible film, and then the entire flexible array is attached to the surface of the electrical flexible connector body to form a grid distribution.

[0066] The grid spacing, ranging from 0.8 to 1.2 mm, optimizes the density of the strain gauge array. This ensures sufficient spatial resolution to capture local strain changes while avoiding the negative impact of excessive strain gauges on the overall flexibility of the electrical flexible connection, and reduces the complexity of data acquisition and processing. Specifically, the optimal grid spacing can be determined through finite element analysis (FEA) simulation based on the typical bending radius and strain gradient distribution characteristics of the electrical flexible connection, ensuring sufficient strain data in critical areas. Alternatively, in practical applications, experiments can be conducted to verify the accuracy and data redundancy of strain detection under different grid spacings, thereby selecting an optimal spacing that balances detection accuracy and system complexity.

[0067] By optimizing the size, embedding depth, and grid distribution and spacing of the micro-strain gauges on the surface of the flexible electrical connector, this application improves the accuracy and reliability of strain detection. The miniaturized size ensures minimal impact of the strain gauges on the flexibility of the flexible electrical connector while capturing fine local strain changes. The precise embedding depth guarantees tight coupling between the strain gauges and the substrate material, allowing the strain signal to accurately reflect the material's deformation state and avoiding measurement errors caused by strain gauge detachment or damage. The grid distribution and optimized grid spacing achieve comprehensive and uniform coverage of the strain field across the entire surface of the flexible electrical connector, effectively avoiding detection blind spots and providing more complete and representative strain data. These improvements collectively provide the control unit with high-precision and high-reliability strain signal input, enabling more accurate calculation of the current bending radius of the flexible electrical connector. This allows for precise dynamic adjustment of the electric field strength of the electrophoresis system, ultimately ensuring that the insulation layer thickness adapts more accurately to the dynamic bending conditions of the flexible electrical connector, effectively alleviating bending stress and improving the durability and reliability of the insulation layer.

[0068] In some of the above-mentioned solutions of this application, epoxy-silica sol is proposed to be used to directionally migrate and deposit to form an insulating layer under the action of an electric field. In this process, if the particle size, pH value and temperature of the sol are not precisely controlled, the deposition rate may be unstable, the particle distribution may be uneven or the stability of the sol may decrease, thereby affecting the uniformity, density and mechanical flexibility of the insulating layer, and failing to effectively adapt to the stress distribution requirements under dynamic bending conditions.

[0069] In this regard, this application further proposes that the epoxy-silica sol contains silica particles with a particle size of 40-60 nm and the sol has a pH value of 4.0-5.0 and a temperature of 24-26℃.

[0070] Specifically, the silica particles contained in the epoxy-silica sol have a particle size limited to the range of 40-60 nm. Silica particles refer to silica particles with a size on the nanometer scale, and their particle size affects the stability of the sol, electrophoretic migration behavior, and the performance of the final coating. Controlling the particle size within this range aims to ensure that the particles remain stably dispersed in the sol, avoiding coarse deposition due to excessively large particles or agglomeration problems caused by excessively small particles, and achieving uniform migration and close packing under the action of an electric field, thereby improving the density and mechanical strength of the insulating layer. Silica nanoparticles within this particle size range can be obtained in various ways. For example, they can be prepared by the sol-gel method, where specific particle size ranges of silica nanoparticles are obtained by precisely controlling the reactant concentration, catalyst dosage, and reaction time. In the sol-gel method, the particle size is controlled by hydrolyzing and condensing tetraethyl silicate (TEOS) in an alcohol solution and adjusting the ammonia concentration and water content. Alternatively, commercially available silica nanoparticle dispersions with strictly screened particle sizes can be purchased and then mixed with epoxy resin components to prepare a sol. For example, a commercially available silica nanoparticle dispersion with a narrow particle size distribution can be selected and subjected to necessary purification or surface modification treatment.

[0071] Meanwhile, the pH value of the sol is precisely controlled between 4.0 and 5.0. pH value is an indicator of the acidity or alkalinity of the sol, affecting the surface charge of particles, colloidal stability, and electrophoretic migration efficiency. Maintaining an acidic environment of 4.0-5.0 aims to maintain the colloidal stability of the sol, effectively preventing the aggregation of silica particles, while promoting the directional movement of ions during electrophoretic migration, ensuring a controllable deposition rate and consistent insulating layer thickness. The pH value of the sol can be adjusted by adding appropriate amounts of acidic or alkaline substances. Dilute hydrochloric acid or dilute nitric acid can be used to adjust the pH value to the target range, and a pH meter can be used for real-time monitoring. Alternatively, epoxy resin or dispersant components with specific pH buffering capabilities can be selected, allowing them to naturally form or stabilize within the desired pH range after mixing.

[0072] Furthermore, the temperature of the sol is controlled within 24-26°C. The temperature of the sol is a crucial parameter affecting its viscosity, particle Brownian motion, and electrophoretic deposition kinetics. Maintaining the temperature within this narrow range of 24-26°C aims to ensure constant sol viscosity and reaction kinetics, preventing temperature fluctuations from affecting deposition efficiency or causing uneven insulation layer performance, thereby providing reliable and flexible insulation protection during dynamic bending. The sol temperature can be precisely controlled by placing the electrophoresis tank in a constant-temperature water bath or chamber, using a circulating water bath system with a temperature control module to immerse the electrophoresis tank; alternatively, temperature sensors and heating / cooling devices can be installed inside the electrophoresis tank to locally or globally regulate the sol temperature and maintain it within the target temperature range.

[0073] By precisely controlling the particle size, pH value, and temperature of the epoxy-silica sol, this application ensures the stability and controllability of the electrophoretic deposition process. Silica nanoparticles with a particle size of 40-60 nm remain stably dispersed in the sol and achieve uniform migration and close packing under the influence of an electric field, thereby forming a dense insulating layer with high mechanical strength. The acidic environment with a pH value of 4.0-5.0 maintains the colloidal stability of the sol, effectively preventing the aggregation of silica particles and promoting the directional movement of ions during electrophoretic migration, ensuring stable deposition rate and consistent insulating layer thickness. Simultaneously, controlling the temperature within a narrow range of 24-26℃ ensures constant sol viscosity and reaction kinetics, avoiding adverse effects of temperature fluctuations on deposition efficiency and insulating layer performance. The synergistic optimization of these parameters results in an insulation layer with excellent uniformity, density, and mechanical flexibility under dynamic bending conditions. This effectively adapts to the stress distribution requirements under different bending curvatures, thereby improving the insulation reliability and durability of the electrical flexible connection body during long-term dynamic use. It also solves the problem of poor insulation layer performance caused by improper control of sol parameters in existing technologies.

[0074] In some of the solutions described above in this application, the electric field strength is dynamically adjusted to form an insulating layer in order to optimize the insulation layer thickness to adapt to dynamic bending conditions. However, in this process, a single deposition may not be able to fully guarantee the integrity and uniformity of the insulating layer, resulting in insufficient insulation resistance or local defects, which affects the insulation reliability and long-term durability.

[0075] In this regard, this application further proposes that, after forming the insulating layer, the method further includes: applying a test voltage of 100-150V to the electrical flexible connection body covered with the insulating layer and measuring its insulation resistance value; the insulation resistance value is less than 1.0×10⁻⁶. 9 If Ω, the steps of dynamically adjusting the electric field strength and directional deposition are repeated to perform secondary deposition; the number of cycles for secondary deposition does not exceed 3.

[0076] Applying a test voltage of 100-150V to the insulating flexible connector body is a step designed to simulate the voltage stress experienced by the flexible connector body in a real working environment, in order to evaluate the withstand voltage performance and potential weaknesses of the insulation layer. By applying a test voltage within a specific range, defects in the insulation layer are effectively stimulated, providing a basis for subsequent quality assessment. A preset 100-150V DC or AC voltage is applied to the insulating flexible connector body using a high-voltage tester and maintained for a certain period of time, such as 10 to 60 seconds. Alternatively, a stepped voltage increase can be used, gradually increasing the voltage from a lower level to 100-150V, to more precisely detect the breakdown threshold or partial discharge phenomenon of the insulation layer.

[0077] Subsequently, the insulation resistance value is measured. Measuring the insulation resistance value is a key indicator for quantitatively evaluating the performance of the insulation layer, reflecting the insulating material's ability to prevent current from flowing through it. Accurate measurement allows for an objective assessment of the insulation layer's integrity, density, and the presence of microscopic defects, avoiding errors caused by subjective judgment. Specifically, a high-resistance meter or insulation resistance tester can be used. The two ends of the tester are connected to the electrical flexible connector body and the surface or external electrodes of the insulation layer, respectively. While applying a test voltage, the minute current flowing through the insulation layer is measured, and the insulation resistance value is calculated according to Ohm's law. Alternatively, a non-contact capacitance measurement method can be used to indirectly evaluate the insulation performance by measuring the dielectric constant and loss tangent of the insulation layer, and then correlate these values ​​with the insulation resistance value.

[0078] When the insulation resistance value is less than 1.0 × 10 9 At Ω, this condition sets a specific threshold for insulation performance. When the measured insulation resistance value is below 1.0 × 10 Ω, this condition is considered a threshold. 9 A value of Ω indicates that the insulation layer has failed to meet the expected insulation standard, and may have uneven thickness, local voids, microcracks, or other defects, requiring further repair or reinforcement. This threshold is determined based on a comprehensive consideration of the required insulation reliability of the electrical flexible connection body in a specific application scenario. In some high-voltage or high-humidity environments, a higher insulation resistance value may be required; while in other applications, this threshold is sufficient.

[0079] If the insulation resistance value is lower than a preset threshold, the steps of dynamically adjusting the electric field strength and directional deposition are repeated for a second deposition. This step allows the process system to repair and strengthen the insulation layer if it fails the test. By repeating the electrophoretic deposition process, epoxy-silica sol can be deposited again on top of the existing insulation layer to fill defects, increase local thickness, or improve overall uniformity. The control unit can intelligently adjust the electric field strength of the electrophoresis system based on the test results after the first deposition, applying a higher local electric field strength in areas with lower insulation resistance to promote preferential deposition of the sol in those areas. Alternatively, the same dynamic adjustment strategy as the first deposition can be maintained, but the deposition time can be extended or the sol concentration increased to ensure an overall improvement in the insulation layer thickness.

[0080] After the initial deposition and curing, a full-length insulation resistance scan test is performed. If the insulation resistance value of a certain section is lower than 1.0 × 10⁻⁶, the insulation resistance is determined. 9 If Ω is found, then that section is marked as the area to be enhanced. The secondary deposition process is as follows: 1. Re-sensing: The electrical flexible connection body is placed back into the electrophoresis tank, and the micro strain gauges start working again to monitor its shape in real time. At this time, it is usually in a flat state and R is extremely large.

[0081] 2. Local Enhancement: The control unit initiates a strong electric field deposition mode only in the area to be enhanced. Based on the historical maximum curvature data of this area during the first deposition, the upper limit electric field intensity corresponding to that curvature is directly called for deposition, and the duration is preset according to the severity of the defect.

[0082] 3. Cycling and Termination: Retest after each secondary deposition. Terminate the process if the resistance of all regions meets the standard or if three cycles have been completed.

[0083] The number of secondary deposition cycles should not exceed three. This limitation aims to balance the improvement in insulation performance with process efficiency, material consumption, and insulation layer flexibility. While multiple depositions can further improve insulation performance, excessive deposition cycles may lead to excessively long process times, material waste, and potentially excessively thick insulation layers, thereby affecting the flexibility of the electrical flexible connection and even introducing new stress concentration problems. Limiting the number of cycles to three is based on empirical data and performance test results, ensuring reliable insulation effects within a limited number of repetitions while avoiding over-processing. After each secondary deposition, an insulation resistance test can be performed again. If the standard is met, deposition is stopped; if the standard is still not met, the next deposition is performed until the upper limit of three cycles is reached or the insulation performance meets the standard.

[0084] Insulation resistance testing was conducted in a standard laboratory environment at a temperature of 23±2℃ and a relative humidity of 50%±10%. A 120V DC test voltage was applied using a DC regulated power supply for 60 seconds. After the reading stabilized, the current flowing through the insulation layer was directly measured using a high-resistance meter, and the resistance value was calculated. During measurement, the main conductor of the electrical flexible connector was used as one pole, and the conductive tape wrapping it, ensuring full contact with the outer surface of the insulation layer, served as the other pole. This test method complies with the basic requirements of IEC 60695 standard.

[0085] Through the above technical solution, this application introduces a mechanism for performance testing and adaptive repair of the electrically flexible connection body with an already formed insulation layer. After the insulation layer is formed, by applying a test voltage and measuring its insulation resistance value, the quality and integrity of the insulation layer can be objectively and quantitatively evaluated, and potential local defects or insulation deficiencies from a single deposition can be detected in a timely manner. When the insulation resistance value does not meet the preset standard, the system can intelligently repeat the steps of dynamically adjusting the electric field strength and directional deposition for secondary deposition, thereby specifically repairing defects, enhancing insulation performance, and ensuring that the insulation layer meets reliable usage requirements. By limiting the number of secondary deposition cycles, problems such as reduced process efficiency, material waste, and damage to the flexibility of the insulation layer that may result from over-deposition are effectively avoided. Under the premise of ensuring insulation reliability, the controllability and economy of the process are optimized. This feedback-correction closed-loop control mechanism improves the yield and insulation quality stability of the dynamic bending adaptive flexible connection electrophoretic insulation process, enabling the insulation layer to maintain excellent insulation performance and mechanical flexibility under dynamic bending conditions.

[0086] In some of the embodiments described above in this application, the electric field strength is dynamically adjusted to optimize the thickness distribution of the insulating layer. However, during the electrophoretic deposition process, the epoxy-silica sol has insufficient fluidity, resulting in a low flow rate in the surface area of ​​the electrical flexible connection body. This may cause uneven deposition, excessively thick or thin local insulation layers, and thus affect the density and mechanical stability of the insulation layer.

[0087] In this regard, this application further proposes that the bottom of the electrophoresis tank is provided with a microchannel, the width of which is 0.15-0.25mm, to accelerate the flow of the epoxy-silica sol and make its flow velocity in the surface area of ​​the electrical flexible connection body not less than 0.4m / s.

[0088] Specifically, microchannels refer to channel structures formed at the bottom of the electrophoresis tank. Their main function is to guide and control the flow direction and speed of the electrophoretic sol, thereby optimizing the sol's transfer efficiency on the surface of the electrical flexible connector. Microchannels can be formed directly on the tank material through precision machining at the bottom of the electrophoresis tank, such as laser etching or CNC milling; alternatively, they can be prefabricated modules with microchannel structures, such as those manufactured using micro-injection molding or 3D printing, and then installed or integrated into the bottom of the electrophoresis tank. The width of the microchannel is a key parameter affecting the sol's flow characteristics and deposition uniformity. Limiting the width to the range of 0.15-0.25 mm aims to achieve effective accelerated sol flow while avoiding the risk of clogging due to excessively narrow channels, and the problem of reduced fluid shear force and reduced acceleration effect due to excessively wide channels. Achieving this width range can be ensured through high-precision manufacturing processes. For example, during the microchannel design phase, fluid dynamics simulation software is used for optimization to determine the optimal geometric parameters; during manufacturing, high-precision molds or processing equipment are employed to ensure the accuracy of the microchannel dimensions. Microchannels accelerate the flow of epoxy-silica sol by reducing the fluid cross-sectional area, thereby increasing the fluid velocity at the same flow rate, according to fluid dynamics principles. This acceleration helps to continuously deliver fresh sol to the surface of the electrical flexible connector and remove byproducts or depleted sol generated during deposition. Methods to accelerate sol flow include: designing the microchannel as a contraction-expansion structure to achieve local acceleration using the Venturi effect; and applying a pressure difference at the microchannel inlet to drive the sol through the microchannel at a faster speed. Ensuring that the flow velocity of the epoxy-silica sol on the surface region of the electrical flexible connector is not less than 0.4 m / s is a crucial condition for ensuring the uniformity and efficiency of electrophoretic deposition. Low flow rates may cause the sol to be depleted in localized areas, resulting in an uneven deposition layer; while excessively high flow rates may erode the deposited insulation layer. This flow rate can be achieved in several ways: for example, by precisely controlling the inlet and outlet pressure difference of the electrophoresis tank to regulate the overall circulation speed of the sol; or by combining microchannel geometry design with optimized channel layout and dimensions to achieve and maintain the required minimum flow rate in the critical deposition areas of the electrical flexible connector.

[0089] By employing the aforementioned technical solution, microchannels of a specific width are created at the bottom of the electrophoresis tank, effectively accelerating the flow of epoxy-silica sol on the surface of the flexible electrical connector. This accelerated flow ensures a continuous supply of fresh sol, preventing its depletion in localized areas and thus improving the uniformity of electrophoretic deposition. The sol flow rate is set at no less than 0.4 m / s, effectively preventing localized excessively thick or thin insulation layers, resulting in a denser and more mechanically stable insulation layer. Combined with the aforementioned technical solution of dynamically adjusting the electric field strength to optimize the insulation layer thickness distribution, this ensures that the insulation layer can adaptively adjust its thickness under dynamic bending conditions while maintaining excellent deposition quality and structural integrity. This effectively alleviates bending stress and improves the overall reliability and service life of the flexible connector.

[0090] In some of the solutions mentioned above in this application, the control unit calculates the bending radius of curvature based on the strain signal to dynamically adjust the electric field strength. In this process, the calculation may only rely on a single or local strain signal, which cannot fully capture the actual deformation distribution on the surface of the electrical flexible connection body. This results in the bending radius of curvature being obtained inaccurately and unreliably, which in turn affects the accuracy of subsequent electric field adjustment and makes it impossible for the insulation layer thickness to be optimally adapted to the dynamic bending condition.

[0091] To address this, this application further proposes a control unit that uses strain distribution data from micro-strain gauges to calculate the current bending radius of curvature on the surface of the electrical flexible connector. The control unit is the core processing module responsible for receiving, processing data, and issuing commands. The control unit can be an embedded microcontroller (MCU) with an integrated analog-to-digital converter (ADC) for receiving strain signals and sufficient processing power to execute curvature calculation algorithms; alternatively, it can be a programmable logic controller (PLC) or an industrial PC, working with appropriate signal acquisition cards and software algorithms to achieve parallel processing of large amounts of strain data and curvature calculation. The strain distribution data from the micro-strain gauges refers to the set of strain values ​​detected by multiple micro-strain gauges at different locations on the surface of the electrical flexible connector, collectively reflecting the overall deformation of the electrical flexible connector under bending conditions. For example, the micro-strain gauges can be arranged in an array along the length and width directions of the electrical flexible connector to form two-dimensional strain distribution data; or, the micro-strain gauges can be densely arranged in key areas according to the main bending direction and stress characteristics of the electrical flexible connector to obtain more refined local strain distribution data.

[0092] Based on the aforementioned strain distribution data, the control unit calculates the curvature of the surface of the electrical flexible connector. This calculation involves using a mathematical model and algorithm, with strain distribution data collected by micro-strain gauges, to deduce the degree of bending of the electrical flexible connector surface at a specific point. A finite element analysis (FEA) inverse solution method is employed, inputting the measured strain data into a pre-established geometric model of the electrical flexible connector. Iterative calculations yield the curvature distribution that best matches the measured strain. Alternatively, based on beam bending theory or plate / shell theory in elasticity mechanics, an analytical or semi-analytical relationship between strain and curvature can be established. A continuous curvature distribution can be calculated from discrete strain data using fitting or interpolation algorithms. Local curvature can be calculated using the three-point method or multi-point fitting circular arc method, utilizing data from adjacent micro-strain gauges. Finally, the control unit obtains the current bending radius of curvature of the electrical flexible connector under its current bending state by taking the reciprocal of the calculated curvature value. For non-uniform bending, the local radius of curvature in different regions can be calculated, or the minimum radius of curvature in a key region can be used as a representative value.

[0093] Through the above technical solution, the control unit utilizes strain distribution data provided by multiple micro-strain gauges to comprehensively capture the deformation state of the electrical flexible connector body, avoiding deviations that may be caused by single or local strain signals. Based on this, by directly calculating the curvature of the electrical flexible connector body surface, its true bending shape can be more accurately reflected, thus obtaining a precise and reliable current bending radius. This optimized method of obtaining the radius of curvature provides a solid foundation for the control unit to dynamically adjust the electric field strength of the electrophoresis system according to a preset curvature-electric field mapping relationship. Given that the thickness of the insulation layer is negatively correlated with the current bending radius of curvature, a precise radius of curvature ensures that the insulation layer thickness is optimally adapted to different bending regions. That is, a thicker insulation layer is formed in areas with high bending stress to ensure insulation strength, while a thinner insulation layer is formed in areas with low bending stress to maintain flexibility. This effectively solves the problem that the insulation layer thickness cannot adapt to dynamic bending conditions in traditional processes, improves the insulation performance and mechanical flexibility of the electrical flexible connector body during dynamic use, and effectively alleviates problems such as insulation layer cracking, peeling, or unnecessary stress.

[0094] In some of the solutions described above in this application, an electrophoresis system is proposed to apply an electric field for dynamic deposition. However, in this process, the electrode arrangement may result in uneven electric field distribution, unstable deposition, or electrode degradation due to inconsistent spacing or poor corrosion resistance of the material, affecting the uniformity of the insulating layer and the reliability of the process.

[0095] In this regard, this application further proposes that the electrophoresis system includes a positive electrode and a negative electrode arranged in parallel on both sides of the electrical flexible connection body, the distance between the positive electrode and the negative electrode is 4-6 mm and the electrode material is a platinum-iridium alloy.

[0096] Specifically, the positive and negative electrodes in the electrophoresis system are key components for generating the electric field during the electrophoresis process. By applying voltage, they create a directional electric field within the electrophoresis tank, driving charged epoxy-silica sol particles to migrate and deposit towards the electrical flexible connector substrate. The positive and negative electrodes are positioned parallel to each other on both sides of the electrical flexible connector substrate to ensure that the electric field direction is approximately parallel to or perpendicular to the surface of the substrate and its cross-section. This allows the electric field to act relatively uniformly across the entire surface of the substrate when it bends, avoiding electric field distortion. The electrodes can be designed as elongated strips or plates, placed parallel to the length of the electrical flexible connector substrate; alternatively, the electrodes can be mesh-like or multi-segmented structures, with precise alignment ensuring parallelism with the substrate.

[0097] The distance between the positive and negative electrodes is 4-6 mm. Electrode spacing is a crucial parameter affecting the electric field strength and uniformity. During electrophoresis, the electric field strength directly influences the migration rate of the sol particles and the deposition efficiency. Setting a spacing within this range aims to optimize the electric field strength gradient, ensuring that epoxy-silica sol particles can be deposited uniformly at an appropriate rate, avoiding excessively rapid deposition and uneven coating due to an excessively strong electric field, or low deposition efficiency due to an excessively weak electric field. The distance between the electrodes and the electrical flexible connector body can be precisely controlled using a mechanical fixing device, ensuring consistency throughout the electrophoresis tank; alternatively, an adjustable electrode holder can be used, allowing for fine-tuning of the spacing during process debugging to accommodate electrical flexible connector bodies of different sizes or shapes.

[0098] The electrode material is a platinum-iridium alloy. The choice of electrode material is crucial for the stability of the electrophoresis process and the lifespan of the electrode. Since the electrode operates long-term in the electrophoresis solution, it needs excellent corrosion resistance and conductivity. Platinum-iridium alloys possess excellent chemical stability, corrosion resistance, and good conductivity. In electrophoresis solutions containing epoxy-silica sol, platinum-iridium alloys effectively resist redox reactions and acid-base corrosion, preventing electrode material dissolution or passivation, thereby ensuring a long-term stable output of the electric field and reducing the impact of electrode contamination on deposition quality. The electrode can be made of pure platinum or pure iridium, or other precious metal alloys, such as platinum-rhodium alloys, which also have good corrosion resistance. The electrode can also be prepared by coating a substrate material such as titanium with a platinum-iridium alloy or other precious metal coating to balance cost and performance.

[0099] By employing the aforementioned technical solution, the positive and negative electrodes in the electrophoresis system are positioned parallel to each other on both sides of the flexible electrical connector body. This ensures that the electric field direction remains consistent with the axis of the flexible electrical connector body. Even when the flexible electrical connector body undergoes dynamic bending deformation, the stability and uniformity of the electric field are maintained, preventing electric field distortion or deviation. This guarantees the directional migration and uniform deposition of epoxy-silica sol particles across the entire surface. Simultaneously, the 4-6mm spacing between the positive and negative electrodes effectively controls the electric field intensity gradient, resulting in a moderate migration speed for the sol particles and a more stable and uniform deposition process. This avoids deposition defects caused by excessively strong or weak electric fields, thereby improving the density and uniformity of the insulation layer. Furthermore, the use of platinum-iridium alloy as the electrode material, with its high corrosion resistance, allows for long-term stable operation in the complex chemical environment of the electrophoresis tank. This effectively prevents the electrode material from dissolving, passivating, or contaminating the electrophoresis solution, thus maintaining a long-term stable output of the electric field and the reliability of the process, ensuring the continuous consistency of the insulation layer deposition quality. Therefore, by optimizing the electrode configuration, this application effectively solves the problems of electric field stability and uniformity during electrophoresis, improves the quality of insulation layer deposition and process reliability, provides a solid electric field foundation for realizing adaptive insulation process with dynamic adjustment of insulation layer thickness according to bending curvature radius, and finally obtains an electrical soft connection body with excellent insulation performance and mechanical flexibility.

[0100] The following example will provide a more detailed explanation of the above technical solution: This flexible electrical connector, used in the joints of industrial robots, requires frequent dynamic bending during operation. The connector is a flexible electrical connection body made of multiple strands of fine conductors braided together.

[0101] First, multiple micro-strain gauges are pre-embedded on the surface of the electrical flexible connector. These micro-strain gauges are 0.5mm × 0.5mm in size, embedded to a depth of 2μm, and distributed in a grid pattern along the surface of the electrical flexible connector with a grid spacing of 1mm. This precise embedding method ensures that the strain gauges can accurately sense local deformation without affecting the overall flexibility of the electrical flexible connector.

[0102] Subsequently, the flexible electrical connector body is placed in an electrophoresis tank. The bottom of the electrophoresis tank has microchannels 8 with a width of 0.2 mm to accelerate the flow of the epoxy-silica sol within the tank, ensuring a flow velocity of at least 0.4 m / s on the surface of the flexible electrical connector body. The electrophoresis tank contains epoxy-silica sol comprising silica nanoparticles with a particle size of 50 nm, has a pH of 4.5, and is maintained at a temperature of 25°C. The electrophoresis system also includes positive and negative electrodes 10 arranged parallel to each other on both sides of the flexible electrical connector body, with an electrode spacing of 5 mm, and the electrode material is a platinum-iridium alloy.

[0103] During the insulation deposition process, the flexible electrical connector body simulates its dynamic bending condition at a robot joint. Micro-strain gauges detect the surface strain of the flexible electrical connector body in real time under bending conditions and generate strain signals. The control unit receives these strain signals and calculates the radius of curvature κ of the current bending region of the flexible electrical connector body based on the strain signals. When the flexible electrical connector body undergoes a sharp bend, the control unit may calculate the current bending radius of curvature κ as 1.5 mm. The thickness of the flexible electrical connector body is h = 0.5 mm. When an outer strain gauge reading of +800 με and an inner symmetrical strain gauge reading of -800 με are detected at a certain point, then Δε = 1600 με = 0.0016, and the current bending radius of curvature R = 0.5 / 0.0016 = 312.5 mm is calculated. Considering the nonlinearity of the braided structure, corrections can be made using a pre-calibrated "strain difference - radius of curvature" lookup table.

[0104] The control unit dynamically adjusts the electric field strength of the electrophoresis system based on a preset curvature-electric field mapping relationship and the calculated current bending radius κ. If the current bending radius κ is 1.5 mm, satisfying the condition κ ≤ 2 mm, the control unit 1 adjusts the electric field strength to 10 V / cm, falling within the range of 8-12 V / cm. If the bending is gentler, and the calculated current bending radius κ is 3 mm, satisfying the condition 2 mm < κ ≤ 5 mm, the control unit adjusts the electric field strength to 5 V / cm, falling within the range of 4-6 V / cm. If the bending is even gentler, and the calculated current bending radius κ is 6 mm, satisfying the condition κ > 5 mm, the control unit adjusts the electric field strength to 2 V / cm, falling within the range of 1-3 V / cm.

[0105] Under the influence of a dynamically adjusted electric field, particles in the epoxy-silica sol migrate directionally and deposit on the surface of the flexible electrical connector, forming an insulating layer. The thickness of this insulating layer is dynamically adjusted according to the current bending radius κ, and the two are negatively correlated. When the radius of curvature κ is 1.5 mm, the insulating layer thickness is 15 μm; when the radius of curvature κ is 3 mm, the insulating layer thickness is 8 μm, at which point the thickness δ of the insulating layer satisfies the relationship δ = a - bκ; when the radius of curvature κ is 6 mm, the insulating layer thickness is 5 μm. This thickness-adaptive insulating layer forms a thicker insulating layer in areas of high bending stress to enhance tensile strength, while forming a thinner insulating layer in areas of low bending stress to maintain flexibility, avoiding the cracking or decreased flexibility problems caused by uniform insulating layer thickness in traditional processes.

[0106] After the insulation layer is formed, a test voltage of 120V is applied to the electrical flexible connection body covered with the insulation layer, and its insulation resistance value is measured. If the measured insulation resistance value is lower than 1.0 × 10⁻⁶, the insulation resistance is considered insufficient. 9If the value is Ω, the control unit will repeatedly perform the steps of dynamically adjusting the electric field strength and directional deposition to conduct a secondary deposition, further improving the insulation performance. This secondary deposition cycle is repeated no more than three times, ensuring the quality and reliability of the insulation layer.

[0107] Compared to existing technologies where the insulation layer thickness is fixed and cannot be adjusted in real time, this example achieves adaptive distribution of the insulation layer thickness by sensing the real-time deformation state of the electrical flexible connection body online and dynamically adjusting the electrophoretic deposition parameters accordingly. This allows the insulation layer to have sufficient thickness in areas subjected to high bending stress to prevent cracking, while maintaining a thinner thickness in areas with low bending stress to preserve flexibility. This effectively solves the technical problem of balancing insulation performance and mechanical flexibility in traditional processes.

[0108] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A dynamic bending adaptive flexible connection electrophoretic insulation process, characterized in that, The process includes the following steps: Includes an electrical flexible connection body, which is a flexible conductive component made of multiple strands of fine conductors braided or twisted together; Multiple micro-strain gauges are embedded in the surface of the electrical flexible connection body; The surface strain of the flexible connector body under dynamic bending conditions is detected in real time by micro strain gauges, and strain signals are generated. The control unit receives strain signals and calculates the current bending radius of curvature of the electrical flexible connection body based on the strain signals; The control unit dynamically adjusts the electric field strength of the electrophoresis system based on a preset curvature-electric field mapping relationship and the current curvature radius. The flexible electrical connector is placed in an electrophoresis tank containing epoxy-silica sol, and the epoxy-silica sol is directionally migrated and deposited on the surface area of ​​the flexible electrical connector under the action of electric field strength to form an insulating layer. The thickness of the insulating layer is configured to be dynamically adjusted according to the current bending radius of curvature, and the two are negatively correlated.

2. The dynamic bending adaptive flexible connection electrophoretic insulation process according to claim 1, characterized in that, The negative correlation between the thickness of the insulating layer and the current bending radius specifically satisfies the following conditions: when the current bending radius κ ≤ 2 mm, the thickness of the insulating layer is 12-18 μm; when 2 mm < κ ≤ 5 mm, the thickness of the insulating layer is 4-12 μm; and when κ > 5 mm, the thickness of the insulating layer is 3-7 μm.

3. The dynamic bending adaptive flexible connection electrophoretic insulation process according to claim 2, characterized in that, The curvature-electric field mapping relationship is as follows: when the current curvature radius κ≤2mm, the electric field strength is 8-12V / cm; when 2mm<κ≤5mm, the electric field strength is 4-6V / cm; when κ>5mm, the electric field strength is 1-3V / cm.

4. The dynamic bending adaptive soft-connection electrophoretic insulation process according to claim 3, characterized in that, When the current bending radius κ satisfies 2mm < κ ≤ 5mm, the thickness δ of the insulating layer satisfies the relationship between δ and κ: δ = a - bκ, where a and b are constants, and the value of δ falls within the range of 4-12μm.

5. The dynamic bending adaptive flexible connection electrophoretic insulation process according to claim 1, characterized in that, The micro strain gauges are 0.4-0.6 mm × 0.4-0.6 mm in size, with an embedding depth of 1-3 μm, and are distributed in a grid pattern along the surface of the electrical flexible connection body, with a grid spacing of 0.8-1.2 mm.

6. The dynamic bending adaptive flexible connection electrophoretic insulation process according to claim 1, characterized in that, The epoxy-silica sol contains silica nanoparticles with a particle size of 40-60 nm and has a pH value of 4.0-5.0 and a temperature of 24-26 °C.

7. The dynamic bending adaptive flexible connection electrophoretic insulation process according to claim 1, characterized in that, After forming the insulating layer, the method further includes: A test voltage of 100-150V is applied to the electrical flexible connection body covered with the insulation layer, and its insulation resistance value is measured. The insulation resistance value is less than 1.0 × 10⁻⁶. 9 If Ω, then repeat the steps of dynamically adjusting the electric field strength and directional deposition to perform secondary deposition; The number of cycles for secondary deposition does not exceed three.

8. The dynamic bending adaptive flexible connection electrophoretic insulation process according to claim 1, characterized in that, The bottom of the electrophoresis tank is provided with microchannels, the width of which is 0.15-0.25 mm. These microchannels are used to accelerate the flow of the epoxy-silica sol, ensuring that the flow velocity of the sol in the surface area of ​​the electrical flexible connector body is not less than 0.4 m / s.

9. The dynamic bending adaptive flexible connection electrophoretic insulation process according to claim 1, characterized in that, The control unit obtains the current bending radius of curvature by calculating the curvature of the surface of the electrical flexible connection body based on the strain distribution data of the micro strain gauge.

10. The dynamic bending adaptive flexible connection electrophoretic insulation process according to claim 1, characterized in that, The electrophoresis system includes a positive electrode and a negative electrode arranged in parallel on both sides of the electrical flexible connection body. The distance between the positive electrode and the negative electrode is 4-6 mm, and the electrode material is a platinum-iridium alloy.

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