Flexible electrode dynamic deformation electrochemical machining device based on industrial robots and method

Abstract

A flexible electrode dynamic deformation electrochemical machining device based on industrial robots, composed of an electrolyte circulating filtration device (II), a computer control platform (III), a power supply (IV), a working platform (V), a workpiece (VI), a flexible electrode (VII), two six-degree-of-freedom industrial robots (I) and end effectors (VIII) of the six-degree-of-freedom industrial robots. Provided is an electrochemical machining method of the flexible electrode dynamic deformation electrochemical machining device based on industrial robots. Before machining, industrial robots and end effectors automatically clamp a flexible electrode, and move same to an initial machining position, and the end effectors serve as electrolyte inlets to be connected to electrolyte inlet pipes (VIII-1); during machining, according to a set program, the robots are controlled to move, so as to complete bending deformation of the flexible electrode, and machining of complex profiles is completed in a cutting direction; and after machining, the robots complete retraction of the flexible electrode according to the set program or according to requirements, replace the flexible electrode with the next electrode for subsequent machining. The incorporation of the industrial robots into the device greatly improves the machining flexibility and the automation degree.

Description

Flexible electrode dynamic deformation electrolytic machining device and method based on industrial robot TECHNICAL FIELD

[0001] The application relates to a flexible electrode dynamic deformation electrolytic machining device and method based on an industrial robot and belongs to the technical field of electrolytic machining. BACKGROUND

[0002] A blisk is a core component for realizing structural innovation and technical leap of a new aero-engine, and the blisk integrates a blade and a disk, so that the structure of the engine is greatly simplified, the weight is obviously reduced, and the thrust-to-weight ratio is significantly improved. However, the blisk has a complex structure, the blade is super-thin and twisted, the inter-blade channel is narrow, and the blisk is usually made of a difficult-to-cut material and has a very high precision requirement, so the manufacturing is very difficult. The electrolytic machining technology has become one of main manufacturing methods of the blisk due to high machining efficiency, good surface quality and no tool loss.

[0003] In the patent "Blisk multi-layer progressive composite cathode rotary sleeve electrolytic machining device and method" (application number 202310601679.9, applicant Jiangsu Jucu Precision Manufacturing Research Institute Co., Ltd., inventors Zhao Jianshe, Yue Lei, Gao Wei, Zheng, etc.), a multi-layer progressive design of a cathode is proposed, so that the machining allowance distribution of the blisk is more uniform, and the actual machining requirement of the twisted blisk with a large cross-section change degree is more favorably met.

[0004] In the patent "Blisk electrolytic grooving processing ring electrode and process method" (application number 201210367002.5, applicant Shenyang Liming Aero-engine (Group) Co., Ltd., inventors Zhu Hainan, Yang Jianshi, Yu Bing, Li Wei), a sleeve electrolytic machining method is used to realize efficient machining of the grooving of a wide-chord and large-torsion-angle blade passage of a blisk.

[0005] In the patent "Blisk electrolytic machining method of non-uniform speed double-rotation variable machining blade cathode" (application number 201910756930.2, applicant Nanjing University of Aeronautics and Astronautics, inventors Xu Zhengyang, Wang Jing, Zhu Di), a variable-width machining blade is designed for the cathode, and the cathode is driven to rotate and feed radially at a one-way variable speed according to an imitation track; the blank is driven to rotate and change direction at a variable speed according to an imitation optimized parameter, so that the blade passage is formed on the blank, and the machining allowance distribution uniformity is improved.

[0006] Electrochemical machining (ECM) is a material removal process based on the principle of electrochemical anodic dissolution. The profile of the workpiece is obtained by using a shaped cathode. The design and preparation of the shaped cathode is the key to ensure the machining accuracy of the profile. With the continuous development of aviation power technology, the thrust-to-weight ratio of aeroengines is continuously increasing, and the emergence of various high-profile precision and complex structure blisks has brought great challenges to the design and preparation of electrochemical machining shaped cathodes. Therefore, many electrochemical machining methods using simple shape cathodes have emerged.

[0007] In the patent "Multi-electrode helical feed inter-blade channel electrochemical machining method of integral impeller" (application number 200910025834.7 applicant Nanjing University of Aeronautics and Astronautics, inventor Zhu Di Xu Qing Xu Zhengyang), through the multi-dimensional interpolation movement between the tool cathode and the workpiece anode, a simple shape tubular electrode is used to process the blade channel.

[0008] In the patent "A fixture device and method for high-efficiency electrochemical slotting machining of blisks" (application number 202210485361.4 applicant Nanjing University of Aeronautics and Astronautics, inventor Zhu Di Duan Shuanglu Liu Jia), the rotation of the center spindle is converted into the synchronous deflection movement of multiple tube electrodes, realizing "single-axis input, multi-axis output" and greatly improving the machining efficiency.

[0009] In the patent "Blade disc cascade group electrode electrochemical machining device and method" (application number 202210485311.6 applicant Nanjing University of Aeronautics and Astronautics, inventor Zhu Di Duan Shuanglu Liu Jia Zhu Dong), the workpiece of the blade disc rotates around its own axis, and under the action of electrochemical reaction anodic dissolution, multiple blades can be machined at one time. High-efficiency electrochemical machining of twisted blade blisks is realized, which can greatly improve the machining efficiency.

[0010] In the patent "Flexible electrode dynamic deformation electrochemical machining method and application" (application number 2021126103W applicant Nanjing University of Aeronautics and Astronautics, inventor Zhu Di Xu Zhengyang Liu Lin), a flexible electrode made of rods and tubes with good performance is proposed. In the machining process, the flexible electrode is deformed dynamically by applying a load, thereby completing the machining of complex profiles.

[0011] In the flexible electrode dynamic deformation electrochemical machining, it is often necessary to design corresponding motion mechanisms or use the linkage of multi-axis machine tools to realize the dynamic deformation of the flexible electrode. In addition, in order to realize specific deformation, special mechanisms need to be designed, which increases the manufacturing difficulty of the equipment. Industrial robots are multi-joint manipulators or multi-degree-of-freedom mechanical devices widely used in industrial fields, with certain automation and can realize various industrial processing and manufacturing functions relying on their own power sources and control capabilities. For example:

[0012] In the patent "A robot system for steel structure welding" (application number 202310970866.4 applicant of Huazhong University of Science and Technology, inventor Sun Jun Li Wei Jiang Xin Zhou Xingyu Han Jinyan), the disclosed robot can adapt to different shapes of steel structure welding, has high adaptability and autonomy; can quickly and effectively carry out steel structure welding seam welding operation, reduces labor consumption and improves operation efficiency and accuracy in unattended condition.

[0013] In the patent "A carrying and stacking robot" (application number 200610113034.7 applicant of Tsinghua University, inventor Chen Ke Yang Xiangdong Li Jinquan Jia Zhenzhong), the disclosed robot reduces the requirement for driving elements, does not need counterweight and spring force reduction balancing device, and reduces the weight and cost of the robot body.

[0014] In the patent "Aero-engine inlet passage blade detection robot and detection method" (application number 202310731732.7 applicant of Xi'an Jiaotong University, inventor Yang Laihao Zheng Yi Peng Yinchong et al.), the problems of waste of human resources, low efficiency, human error and space limitation in the current aero-engine field maintenance and repair are solved. The robot provided by the invention can meet the requirements of miniaturization, high thrust and intelligence, and effectively solve the engine blade detection problem.

[0015] Therefore, in order to improve the automation and intelligence level of flexible electrode dynamic deformation electrochemical machining, and avoid designing a complex special mechanism, the present patent combines the advantages of good machining flexibility and high intelligence level of industrial robots with the characteristics of flexible electrode dynamic deformation electrochemical machining, and proposes a flexible electrode dynamic deformation electrochemical machining device and method based on an industrial robot. SUMMARY

[0016] The present application aims to provide a flexible electrode dynamic deformation electrochemical machining device and method based on an industrial robot, and improve the automation and intelligence level of flexible electrode dynamic deformation electrochemical machining.

[0017] Specifically, the present application provides the following technical solutions:

[0018] A flexible electrode dynamic deformation electrochemical machining device based on an industrial robot, comprising:

[0019] The electrochemical machining device is composed of an electrolyte circulation and filtration device, a computer control platform, a power supply, a workbench, a workpiece, a flexible electrode, and two six-degree-of-freedom industrial robots and their end effectors (Ⅷ);

[0020] The above two six-degree-of-freedom industrial robots are structurally identical and symmetrically arranged on the left and right sides of the workbench;

[0021] The six-degree-of-freedom industrial robot is composed of a body, a first mechanical arm, a second mechanical arm, a third mechanical arm, a fourth mechanical arm, and a fifth mechanical arm connected in sequence, wherein the fifth mechanical arm is connected with an end effector; joints A, B, C, D, E, and F are formed in sequence to correspond to Z-direction rotation of the first mechanical arm, Y-direction swing of the second mechanical arm, Y-direction swing of the third mechanical arm, X-direction rotation of the fourth mechanical arm, Z-direction swing of the fifth mechanical arm, and X-direction rotation of the end effector.

[0022] The workpiece is installed on the work platform and connected to the positive pole of the power supply, the work platform has a liquid return groove and is in communication with the liquid return pipeline of the electrolyte circulating and filtering device.

[0023] The flexible electrode is made of a metal with good elasticity, and has a hollow tubular structure with an array of holes and slits in the side wall, or an elongated sheet-shaped electrode; the two ends of the flexible electrode are clamped by the end effector and connected to the negative pole of the power supply.

[0024] The computer control platform mainly integrates the control systems of the industrial robot, the electrolyte circulating and filtering device, and the power supply; the movement of the industrial robot, the circulation and filtration of the electrolyte, and the on-off of the current are controlled simultaneously by the computer control platform.

[0025] The flexible electrode dynamic deformation electrolytic machining device based on the industrial robot comprises:

[0026] The end effector is composed of a liquid inlet pipe and a clamping device.

[0027] The liquid inlet pipe is connected to the liquid inlet pipeline of the electrolyte circulating and filtering device as an electrolyte inlet.

[0028] The clamping device is used to clamp the flexible electrode.

[0029] The end effector is integrally connected to the fifth mechanical arm of the industrial robot, and the automatic clamping, dynamic deformation, and movement of the flexible electrode are realized by the cooperation of the industrial robot and the end effector.

[0030] The flexible electrode dynamic deformation electrolytic machining device based on the industrial robot comprises:

[0031] The electrolyte circulating and filtering device is composed of a turbid liquid tank, a clear liquid tank, a liquid inlet valve, a pressure gauge, a water pump, a liquid return valve, and a plate-and-frame filter.

[0032] The electrolytic machining method using the flexible electrode dynamic deformation electrolytic machining device based on the industrial robot comprises the following stages: a preparation stage: through the computer control platform, the industrial robot and the end effector complete automatic clamping of the flexible electrode, and are moved to an initial machining position, the end effector is connected with the liquid inlet pipeline of the electrolyte circulation filtering device as an electrolyte inlet;

[0033] A machining stage: through the computer control platform, the industrial robot, the electrolyte circulation filtering device and the power supply are simultaneously operated, the multi-degree-of-freedom motion of the industrial robot is controlled according to the set program, so that the bending deformation of the flexible electrode is completed, and the machining of a complex profile along a cutting direction is completed; when the machining is completed, the industrial robot, the electrolyte circulation filtering device and the power supply are simultaneously stopped through the computer control platform;

[0034] A rollback stage: through the computer control platform, the industrial robot and the end effector complete the rollback of the flexible electrode according to the set program or replace the next flexible electrode according to the requirement for subsequent machining.

[0035] The electrolytic machining method comprises:

[0036] Through the cooperation of each joint of the industrial robot, torque is applied to both ends of the flexible electrode, so that the dynamic deformation of the flexible electrode is realized; the limit load that can be borne by the flexible electrode and the limit deformation generated have an important influence on the motion of each joint of the industrial robot; the calculation is completed through the following process:

[0037] Step 1, for the dynamic deformation of the flexible electrode, the following assumptions are made:

[0038] (1) in the longitudinal symmetry plane of the flexible electrode, a pair of force couples with equal size and opposite directions are applied to make the flexible electrode bend purely;

[0039] (2) there is only normal stress on the cross section of the flexible electrode, and there is no shear stress;

[0040] (3) there is no normal stress between the longitudinal line segments of the flexible electrode;

[0041] Step 2, according to the above assumptions, the strain ε of any longitudinal line segment can be obtained:

[0042] Wherein, ρ is the curvature radius of the neutral layer, and y is the distance from the longitudinal line segment to the neutral layer;

[0043] Step 3, because there is no normal stress between the longitudinal line segments, each line segment is uniaxial stretching or compression; when the stress is less than the proportional limit, according to Hooke's law, the normal stress σ of any longitudinal line segment is:

[0044] Wherein, E is the elastic modulus of the flexible electrode material;

[0045] Step 4, the stress analysis of the cross section of the flexible electrode can obtain the bending moment M:

[0046] Wherein, A is the area of the cross section, I z is the moment of inertia;

[0047] Step 5, the above equation can be solved to obtain the bending normal stress on the cross section of the flexible electrode when bending;

[0048] Step 6, since it is pure bending, the bending moment M of each section is the same, so the maximum normal stress of each section should appear at the farthest distance from the neutral axis.

[0049] Wherein, σ max is the maximum normal stress, y max is the farthest distance of the longitudinal line segment to the neutral layer;

[0050] Step 7, in the bending deformation process, when the maximum normal stress of the flexible electrode is less than the elastic limit σ e of the material, it can ensure that the deformation of the flexible electrode is always in the elastic stage; at this time, the load is removed, and the deformation of the flexible electrode can be restored; that is: σ max <σ e

[0051] Step 8, so the maximum load M max that the flexible electrode can bear:

[0052] Thus the limit load and deformation of flexible electrode of different specifications can be determined, so as to optimize the motion of the joint of the industrial robot.

[0053] Compared with the prior art, the present application has the following beneficial effects.

[0054] (1) A flexible electrode dynamic deformation electrolytic machining device and method based on an industrial robot are provided. The device is composed of an industrial robot with six degrees of freedom, a multifunctional end effector, a flexible electrode, a workpiece, a workbench and the like. Through the movement of the industrial robot with multiple degrees of freedom, automatic clamping, dynamic deformation and displacement of the flexible electrode are realized.

[0055] (2) The automation and intelligent level of the flexible electrode dynamic deformation electrolytic machining are improved. The industrial robot is combined with the flexible electrode dynamic deformation electrolytic machining in the aspect of good machining flexibility and high intelligent level, and the control systems of the industrial robot, the electrolyte circulating and filtering device and the power supply are integrated together, so that the three are simultaneously operated through the computer control platform, the machining efficiency is improved, and the labor cost is reduced.

[0056] (3) The industrial robot is used to realize the dynamic deformation of the flexible electrode, which avoids the design of a special deformation mechanism and improves the universality, and the industrial robot has more degrees of freedom to realize the larger and more complex deformation of the flexible electrode, so that the application range is widened. BRIEF DESCRIPTION OF DRAWINGS

[0057] Fig. 1 is a schematic diagram of the flexible electrode dynamic deformation electrolytic machining device based on the industrial robot;

[0058] Fig. 2 is a schematic diagram of the industrial robot structure;

[0059] Fig. 3 is a schematic diagram of the end effector structure;

[0060] Fig. 4 is a schematic diagram of the electrolyte circulating and filtering device;

[0061] Fig. 5 is a schematic diagram of the industrial robot multi-degree-of-freedom deformation;

[0062] Fig. 6 is a schematic diagram of the flexible electrode dynamic deformation electrolytic machining principle

[0063] Fig. 1 is a schematic diagram of the flexible electrode dynamic deformation electrolytic machining device based on the industrial robot; DETAILED DESCRIPTION

[0064] The specific implementation process of the present application will be described in detail below with reference to the drawings.

[0065] As shown in Fig. 1, the electrolytic processing device is composed of electrolyte circulation filtering device II, computer control platform III, power supply IV, working platform V, workpiece VI, flexible electrode VII and two six-degree-of-freedom industrial robots I and their end effectors VIII; the two six-degree-of-freedom industrial robots I are structurally identical and symmetrically arranged on the left and right sides of the working platform V;

[0066] As shown in Fig. 2, the six-degree-of-freedom industrial robot I is composed of a body I-0, a first-order mechanical arm I-1, a second-order mechanical arm I-2, a third-order mechanical arm I-3, a fourth-order mechanical arm I-4 and a fifth-order mechanical arm I-5 connected in sequence, wherein the fifth-order mechanical arm I-5 is connected with the end effector VIII; joints A to F are formed in sequence to correspond to Z-direction rotation of the first-order mechanical arm, Y-direction swing of the second-order mechanical arm I-2, Y-direction swing of the third-order mechanical arm I-3, X-direction rotation of the fourth-order mechanical arm I-4, Z-direction swing of the fifth-order mechanical arm I-5 and X-direction rotation of the end effector VIII;

[0067] The workpiece VI is installed on the working platform V and connected with the positive pole of the power supply IV; the working platform V has a liquid return groove and is communicated with the liquid return pipeline of the electrolyte circulation filtering device II;

[0068] The flexible electrode VII is made of a metal with good elasticity and has a hollow tubular electrode structure with array holes and slit structure on the side wall or an elongated sheet electrode structure; the two ends of the flexible electrode VII are clamped by the end effector VIII and connected with the negative pole of the power supply IV;

[0069] The computer control platform III mainly integrates the control systems of the industrial robot I, the electrolyte circulation filtering device II and the power supply IV; the movement of the industrial robot I, the circulation filtering of the electrolyte and the on-off of the current are simultaneously controlled by the computer control platform III.

[0070] As shown in Fig. 3, the end effector VIII is composed of a liquid inlet pipe VIII-1 and a clamping device VIII-2; the end effector VIII is integrally connected with the fifth-order mechanical arm I-5 of the industrial robot I, the liquid inlet pipe VIII-1 is connected with the liquid inlet pipeline of the electrolyte circulation filtering device II and the clamping device VIII-2 is used for clamping the flexible electrode VII.

[0071] As shown in Fig. 4, the electrolyte circulation filtering device II is composed of a turbid liquid tank II-1, a clear liquid tank II-1, a liquid inlet valve II-3, a pressure gauge II-4, a water pump II-5, a liquid return valve II-6 and a plate-and-frame filter II-7; the main purpose is to realize the circulation of the electrolyte and the filtering of the electrolytic products.

[0072] As shown in Fig. 5, the industrial robot I can realize multi-degree-of-freedom movement; Fig. 6 is a deformation simulation of the flexible electrode VII under the movement of the industrial robot I, which proves the effectiveness of the device.

[0073] Figure 6 is a schematic diagram of the principle of flexible electrode dynamic deformation electrochemical machining, the flexible electrode VII uses its side wall as the machining surface, and produces corresponding bending deformation along the cutting direction, thereby completing the machining of complex surfaces.

[0074] The process of the flexible electrode dynamic deformation electrochemical machining realized by the device of the embodiment needs the following steps:

[0075] Step one: install the workpiece VI on the work platform V, and connect the positive electrode of the power supply IV;

[0076] Step two: control the industrial robot I and the end effector VIII to complete the automatic clamping of the flexible electrode VII and move to the initial machining position through the computer control platform III;

[0077] Step three: connect the end effector VIII as the electrolyte inlet with the liquid inlet pipeline of the electrolyte circulation and filtration device II, and connect the flexible electrode VII with the negative electrode of the power supply IV;

[0078] Step four: control the industrial robot I, the electrolyte circulation and filtration device II, and the power supply IV to operate simultaneously through the computer control platform III, control the multi-degree-of-freedom motion of the industrial robot I according to the set program, thereby complete the bending deformation of the flexible electrode VII, and complete the machining of complex surfaces along the cutting direction;

[0079] Step five: when the machining is completed, control the industrial robot I, the electrolyte circulation and filtration device II, and the power supply IV to stop working simultaneously through the computer control platform III;

[0080] Step six: control the industrial robot I and the end effector VIII to complete the retreat of the flexible electrode VII according to the set program or replace the next flexible electrode VII according to the demand for subsequent machining through the computer control platform III.

Claims

1. A flexible electrode dynamic deformation electrochemical machining device based on an industrial robot, characterized by: The electrolytic machining device is composed of an electrolyte circulation and filtration device (II), a computer control platform (III), a power supply (IV), a working platform (V), a workpiece (VI), a flexible electrode (VII), and two six-degree-of-freedom industrial robots (I) and their end effectors (VIII); The two six-degree-of-freedom industrial robots (I) have the same structure and are symmetrically arranged on the left and right sides of the working platform (V); The six-degree-of-freedom industrial robot (I) is composed of a body (I-0), a first-level manipulator (I-1), a second-level manipulator (I-2), a third-level manipulator (I-3), a fourth-level manipulator (I-4), and a fifth-level manipulator (I-5), which are connected in sequence. The fifth-level manipulator (I-5) is connected to the end effector (VIII). Joint A corresponds to the Z-rotation of the first-level manipulator, joint B corresponds to the Y-swing of the second-level manipulator (I-2), joint C corresponds to the Y-swing of the third-level manipulator (I-3), joint D corresponds to the X-rotation of the fourth-level manipulator (I-4), joint E corresponds to the Z-swing of the fifth-level manipulator (I-5), and joint F corresponds to the X-rotation of the end effector (VIII). The workpiece (VI) is mounted on a working platform (V) and connected to the positive electrode of a power source (IV). The working platform (V) has a liquid return tank and is connected to a liquid return pipe of an electrolyte circulation and filtering device (II). The flexible electrode (VII) is made of a metal with good elasticity and is a hollow tubular electrode with an array of holes and slits on its side wall, or a slender sheet electrode. Both ends of the flexible electrode (VII) are clamped by an end effector (VIII) and connected to the negative electrode of the power supply (IV). The computer control platform (III) mainly integrates the control system of the industrial robot (I), the control system of the electrolyte circulation and filtration device (II) and the control system of the power supply (IV); the movement of the industrial robot (I), the circulation and filtration of the electrolyte and the on-off of the current are simultaneously controlled by the computer control platform (III).

2. The flexible electrode dynamic deformation electrochemical machining device based on an industrial robot according to claim 1, characterized in that: The end effector (VIII) is composed of a liquid inlet pipe (VIII-1) and a clamping device (VIII-2); Its liquid inlet pipe (VIII-1) serves as an electrolyte inlet and is connected to the liquid inlet pipe of the electrolyte circulation filter device (II); Its clamping device (VIII-2) is used to clamp the flexible electrode (VII); The end effector (VIII) is integrally mounted and connected to the five-stage robotic arm (I-5) of the industrial robot (I). The automatic clamping, dynamic deformation, and movement of the flexible electrode (VII) are achieved through the cooperation between the industrial robot (I) and the end effector (VIII).

3. The flexible electrode dynamic deformation electrochemical machining device based on an industrial robot according to claim 1, characterized in that: The above-mentioned electrolyte circulation filtration device (Ⅱ) consists of a turbid liquid tank (Ⅱ-1), a clear liquid tank (Ⅱ-1), a liquid inlet valve (Ⅱ-3), a pressure gauge (Ⅱ-4), a water pump (Ⅱ-5), a liquid return valve (Ⅱ-6), and a plate and frame filter (Ⅱ-7).

4. The electrochemical machining method using the flexible electrode dynamic deformation electrochemical machining device based on an industrial robot according to claim 1 is characterized in that: The following stages are included: Preparation stage: The industrial robot (I) and the end effector (VIII) are controlled by the computer control platform (III) to automatically clamp the flexible electrode (VII) and move it to the initial processing position. The end effector (VIII) serves as the electrolyte inlet and is connected to the liquid inlet pipe of the electrolyte circulation and filtration device (II). Processing stage: The industrial robot (I), the electrolyte circulation and filtration device (II), and the power supply (IV) are controlled by the computer control platform (III) to operate simultaneously, and the multi-degree-of-freedom motion of the industrial robot (I) is controlled according to the set program, thereby completing the bending deformation of the flexible electrode (VII) and completing the processing of the complex surface along the cutting direction; when the processing is completed, the industrial robot (I), the electrolyte circulation and filtration device (II), and the power supply (IV) are controlled by the computer control platform (III) to stop working simultaneously; Retraction stage: The industrial robot (I) and the end effector (VIII) are controlled by the computer control platform (III) to complete the retraction of the flexible electrode (VII) according to the set program or replace the next flexible electrode (VII) as needed for subsequent processing.

5. The electrolytic machining method according to claim 4, wherein: By cooperating with the joints of the industrial robot, torque is applied to both ends of the flexible electrode, thereby achieving dynamic deformation of the flexible electrode. The ultimate load and ultimate deformation that the flexible electrode can withstand have a significant impact on the movement of the joints of the industrial robot. The calculation is completed through the following process: Step 1: For the dynamic deformation of the flexible electrode, make the following assumptions: (1) In the longitudinal symmetry plane of the flexible electrode, a pair of force couples with equal magnitude and opposite directions are applied, causing the flexible electrode to bend purely; (2) There is only normal stress but no shear stress on the cross section of the flexible electrode; (3) There is no normal stress between the longitudinal segments of the flexible electrode; Step 2: Based on the above assumptions, the strain ε of any longitudinal segment can be obtained: Where ρ is the radius of curvature of the neutral layer, and y is the distance from the longitudinal line segment to the neutral layer; Step 3: Because there is no normal stress between longitudinal line segments, each line segment is unidirectionally stretched or compressed. When the stress is less than the proportional limit, Hooke's law shows that the normal stress σ of any longitudinal line segment is: Wherein, E is the elastic modulus of the flexible electrode material; Step 4: Analyze the cross section of the flexible electrode to obtain the bending moment M: Where A is the area of ​​the cross section, I z is the moment of inertia; Step 5: The above equations can be combined to calculate the bending normal stress on the cross section of the flexible electrode during pure bending; Step 6. Since it is pure bending, the moment M of each section is the same, so the maximum normal stress of each section should appear at the farthest point from the neutral axis. Among them, σ max is the maximum normal stress, y max is the maximum distance from the longitudinal line segment to the neutral layer; Step 7: During the bending deformation process, when the maximum positive stress of the flexible electrode is less than the elastic limit σ of the material e When , the deformation of the flexible electrode can be guaranteed to be always in the elastic stage; when the load is removed, the deformation of the flexible electrode can be restored; that is: s max <s e Step 8: The maximum load M that the flexible electrode can withstand max : This allows the ultimate load and deformation of flexible electrodes of different specifications to be determined, thereby optimizing the movement of industrial robot joints.

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