Visual guidance-based electrochemical polishing system and method for integral component with complex molded surface

Abstract

The invention relates to a visual guidance-based electrochemical polishing system and a visual guidance-based electrochemical polishing method for a complex molded surface integral component, which are mainly applied to electrochemical polishing of the complex molded surface integral component and relate to the field of electrochemical machining. The device is characterized by comprising an image acquisition system, a motion control system and a processing system. Firstly, the surface appearance of a workpiece is obtained through an image acquisition system, and then a motion control system plans a cathode motion track and dynamically adjusts machining parameters according to the surface appearance. And after preliminary polishing, an alcohol nozzle and an air dryer are used for cleaning the surface, then the surface appearance is obtained through an image acquisition system, if the requirement is met, polishing of the next scale division is conducted, and if the requirement is not met, the cathode movement track is planned again for the substandard area, and machining parameters are dynamically adjusted till the requirement is met. Through cooperation of multiple systems, the cathode movement track can be planned according to the specific condition in the surface appearance, machining parameters can be dynamically adjusted, and high-quality electrochemical polishing of the complex profile integral component is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrolytic machining and mechanical vision, and particularly relates to a system and method for electrochemical polishing of a complex profile integral component based on visual guidance. BACKGROUND

[0002] Electrochemical polishing is a surface treatment technology that uses the principle of electrochemical anodic dissolution to precisely process metal surfaces. It has the advantages of wide processing range, high processing efficiency, good processing surface quality, no tool wear, and no mechanical cutting force. It is widely used in medical devices, aerospace, new energy and other fields.

[0003] The application number CN201710748223.X invention discloses an electrochemical polishing method and device. The auxiliary vibration method is used to artificially control the thickness of the viscous film within a suitable range, to accelerate the selective dissolution speed of the metal or prolong the selective dissolution time of the metal, thereby greatly improving the surface quality of the workpiece. All waveforms on the surface of the workpiece, whether high frequency or low frequency, macro or micro, are flattened. However, in actual application, it may take a long time to find the best reference surface position or amplitude, thereby reducing the overall polishing efficiency. Meanwhile, if the surfaces to be polished are different, multiple sets of cathodes need to be designed, resulting in a long manufacturing cycle and increased processing cost. The application number CN202021894272.8 invention discloses an electrochemical polishing device for metal alloy surface treatment, which effectively improves the polishing efficiency. However, it cannot accurately polish according to the specific surface topography of the component. The application number CN202221349213.1 invention discloses an electrochemical polishing device, which can complete the electrochemical polishing of all sides of the workpiece in one feeding. However, in actual processing, if the polished quality of each side is different, the workpiece needs to be re-fed and polished or mechanical polishing is used. Meanwhile, it cannot further locally electrochemically polish the surface topography after polishing to achieve the required polishing effect.

[0004] In summary, at present, the electrochemical polishing process in the polishing of complex profile integral components is mostly by immersing the entire workpiece in the electrolyte for polishing, which has poor localization and leads to poor polishing quality. Therefore, after electrochemical polishing, mechanical polishing is mostly used to achieve the required polishing, and electrochemical polishing cannot be used for further local polishing of the surface topography after polishing to achieve the required polishing.

[0005] Therefore, there is an urgent need for a new type of electrochemical polishing device and method, which has the advantages of simple structure, good adaptability to processing parts, intelligence, high efficiency, and greatly improved integral and local polishing quality of components, and effectively completes the high-quality polishing of complex profile integral components. SUMMARY

[0006] The application relates to a visual guidance-based electrochemical polishing method for a complex profile integral component, which can effectively avoid the defects of the prior art and provides a visual guidance-based electrochemical polishing system for a complex profile integral component.

[0007] The application is used for solving the technical problems by adopting the following technical scheme: a visual guidance-based electrochemical polishing system for a complex profile integral component, which comprises an image acquisition system (1), a motion control system (2) and a machining system (3). Firstly, the image acquisition system (1) is used to acquire the surface topography of a workpiece; then the motion control system (2) plans the cathode motion track according to the surface topography and dynamically adjusts the machining parameters of different polishing regions in the polishing process; after preliminary polishing is completed, the surface is cleaned by using an alcohol sprayer (24) and a drying machine (28); then the image acquisition system (1) is used to acquire the surface topography of the workpiece again; if the polishing meets the requirements, the next polishing is carried out; if the polishing does not meet the requirements, the motion control system (2) plans the cathode motion track according to the surface topography of the region that does not meet the requirements and dynamically adjusts the machining parameters of different polishing regions in the polishing process until the polishing requirements are met. Under the synergistic action of the systems, the cathode motion track can be planned and the machining parameters can be adjusted according to the specific conditions in the surface topography, so that high-quality electrochemical polishing of the complex profile integral component is realized.

[0008] The image acquisition system (1) comprises an auxiliary light source (25), an industrial camera (26), an alcohol sprayer (24) and a drying machine (28), the upper portion of the industrial camera (26) is provided with a transparent protective cover (27), the industrial camera (26), the alcohol sprayer (24) and the drying machine (28) are arranged on the side wall of the working box (47), and the auxiliary light source (25) is arranged on the top wall of the working box (49).

[0009] The motion control system (2) includes an anode motion control system (4) and a cathode motion control system (5), the anode motion control system (4) includes a working box (49), a rotary table (38), and an anode positioning and clamping device (32), the working box is provided with a mounting hole (48) and a liquid discharge hole (47), the anode positioning and clamping device (32) includes a rotating main shaft (33), a bottom plate (37), and a workpiece placing table (34), the rotating main shaft (33) is vertically fixed to the bottom plate (37), and the bottom plate (37) is provided with a tool setting device (35) at the upper portion, the bottom plate (37) is connected with the rotary table (38) and the workpiece placing table (34) by bolts, the workpiece placing table (34) can position the end face of the workpiece, and the rotating main shaft (33) can drive the workpiece to rotate synchronously through a pressing piece (29). The cathode motion control system (5) includes an industrial robot (6), an organ case (7), and a flexible protective cover (8), the organ case (7) is arranged at the mounting hole (48), and the flexible protective cover (8) is arranged at the middle portion of the organ case (7), and the flexible protective cover (8) is connected with the flange through a hose clamp.

[0010] The processing system includes a tool cathode (20), a cathode clamp (10), and a workpiece (31). The cathode clamp (10) has a convex tubular structure, a pipe joint (14) is arranged at the tail end of the horizontal portion of the cathode clamp (10), the head end of the horizontal portion is closed and connected with the industrial robot (6), a conductive copper sleeve (17) is connected with the cathode clamp (10) through a bearing (15) and an interference fit outside the tail end of the horizontal portion, and the conductive copper sleeve (17) is sealed and connected with the cathode clamp (10) through an oil baffle (16), and a power supply joint (18) is arranged at the vertical portion of the cathode clamp (10); an electrolyte inlet pipeline and a cable are sealed through the top of the side wall of the working box (49), the electrolyte inlet pipeline is connected with the cathode clamp (10) through the pipe joint (14), and the cable is connected with the conductive copper sleeve (17) through the power supply joint (18); the center lines of the head end of the horizontal portion, the tail end of the horizontal portion, and the pipe joint (14) of the cathode clamp (10) are coincident.

[0011] The bottom wall (22) of the tool cathode (20) is a horizontal plane, the top wall is a thin tube structure with a straight slot type, the front end opening is an electrolyte inlet (21), the rear end is closed, the rear end horizontal top wall is provided with each hole type electrolyte outlet, the remaining wall part is insulated, the tool cathode (20) is positioned and matched with the cathode clamp (10) through the front end circular boss, and penetrates the cathode clamp (10) and the conductive copper sleeve (17) along the axis, the side wall of the conductive copper sleeve (17) is perpendicular to the axis of the tool cathode (20) and is matched and connected with the cathode fastening screw (19), and the tail end of the cathode fastening screw (19) abuts against the bottom wall (22) of the tool cathode.

[0012] In addition, the rotary workbench (38) comprises a driving motor (50), a rotary main shaft (44), a support base (43), a work turntable (39) and an insulating pad (40), the output end of the driving motor (50) is connected with the rotary main shaft (44) through a transmission mechanism, the axis of the rotary main shaft (44) is vertically arranged, the support base (43) is fixedly connected with the top of the rotary main shaft (44) through a fastening screw, the work turntable (39) is fixedly connected with the top of the support base (43) through an insulating screw, the insulating pad (40) is arranged between the work turntable (39) and the support base (43), the middle part of the insulating pad (40) is in a plate-shaped structure, and the edge is folded downward vertically outside the work turntable (39).

[0013] In addition, the bottom surface of the work tank (49) is an inclined surface that is high near the liquid discharge hole (47) and low far from the liquid discharge hole (47), and the inclination angle of the inclined surface is 8°.

[0014] The application provides a visual guidance-based industrial robot local electrochemical polishing device and method, and has the following beneficial effects: 1. The polishing of complex surface integral components such as an aero-engine integral impeller can be realized, compared with traditional mechanical polishing, there is no macro cutting force, high-hardness difficult-to-cut materials can be machined, the tool cathode has the advantage of no loss, and the deficiency of traditional mechanical polishing in these aspects can be well filled. 2. The image acquisition system captures the workpiece surface image, then the motion control system plans the cathode motion track according to the surface topography of the target area; meanwhile, during the polishing process, the voltage, electrolyte flow rate and other machining parameters of different polishing areas are dynamically adjusted according to the obtained surface topography characteristics, so that the electrochemical polishing effect is optimized, and the workpiece surface reaches an ideal state. 3. The robot's execution end, the horizontal part of the clamping body, and the pipe joint are coaxially arranged, which can effectively prevent the pipe from getting tangled when the cathode rotates. At the same time, the upper part of the tool cathode is insulated to avoid electrochemical dissolution in non-processing areas, reduce stray corrosion, and improve localization. Detailed Implementation

[0015] like Figure 1 As shown, a vision-guided electrochemical polishing system and method for complex surface integral components is provided, including an image acquisition system (1), a motion control system (2), and a processing system (3) designed sequentially.

[0016] The image acquisition system (1) includes an auxiliary light source (25), an industrial camera (26), an alcohol nozzle (24), and a dryer (28). The industrial camera (26) is provided with a transparent protective cover (27) on its upper part. The industrial camera (26), the alcohol nozzle (24), and the dryer (28) are located on the side wall of the work box (47), and the auxiliary light source (25) is located on the top wall of the work box (49).

[0017] The motion control system (2) includes an anode motion control system (4) and a cathode motion control system (5). The anode motion control system (4) includes a work box (49), a rotary worktable (38), and an anode positioning clamping device (32). The work box is provided with a mounting hole (48) and a drain hole (47). The anode positioning clamping device (32) includes a rotating spindle (33), a base plate (37), and a workpiece placement table (34). The rotating spindle (33) is vertically fixed to the base plate (37), and the upper part of the base plate (37) is provided with a tool setting device (35). The base plate (37) is bolted to the rotary worktable (38), and the workpiece placement table (34) is bolted to the base plate (37). The workpiece placement table (34) enables the workpiece to be positioned at the end face. The rotating spindle (33) can drive the workpiece to rotate synchronously through the pressure plate (29). The cathode motion control system (5) includes an industrial robot (6), a bellows cover (7), and a flexible protective cover (8). The bellows cover (7) is located at the mounting hole (48), and the flexible protective cover (8) is located in the middle of the bellows cover (7). The flexible protective cover (8) is connected to the flange through a hose clamp.

[0018] The machining system includes a tool cathode (20), a cathode fixture (10), and a workpiece (31). The cathode fixture (10) has a convex tubular structure (e.g., Figure 2The tail horizontal part is provided with a pipe joint (14) at the head end. The head horizontal part is closed and connected and fixed to the industrial robot (6). The conductive copper sleeve (17) and the cathode clamp (10) are interference-fitted to the outside of the tail horizontal part through the bearing (15) and sealed to it through the oil baffle (16). The vertical part is provided with a power connector (18). The electrolyte inlet pipe and the cable are sealed through the top of the side wall of the working box (49). The electrolyte inlet pipe is connected to the cathode clamp (10) through the pipe joint (14). The cable connects the negative terminal of the power supply to the conductive copper sleeve (17) through the power connector (18). The center lines of the head horizontal part, the tail horizontal part and the pipe joint (14) of the cathode clamp (10) coincide.

[0019] The bottom wall (22) of the tool cathode (20) is a horizontal plane, and the top wall is a thin tube structure with a straight groove (e.g. Figure 3 The front end of the cathode (20) is an electrolyte inlet (21), and the rear end is closed. The horizontal top wall at the rear end is provided with various perforated electrolyte outlets, and the remaining walls are insulated. The tool cathode (20) is positioned and engaged with the cathode clamp (10) through the front end round boss, and passes through the cathode clamp (10) and the conductive copper sleeve (17) along the axis. The side wall of the conductive copper sleeve (17) is perpendicular to the axis of the tool cathode (20) and is connected to the cathode set screw (19). The end of the cathode set screw (19) abuts against the bottom wall (22) of the tool cathode. The horizontal part of the cathode clamp (10), the conductive copper sleeve (17) and the tool cathode (20) are coaxially arranged.

[0020] In addition, the rotary table (38) includes a drive motor (50), a rotary spindle (44), a support base (43), a work turntable (39), and an insulating pad (40). The output end of the drive motor (50) is connected to the rotary spindle (44) through a transmission mechanism. The axis of the rotary spindle (44) is vertically set. The support base (43) is fixed to the top of the rotary spindle (44) by a set screw. The work turntable (39) is fixed to the top of the support base (43) by an insulating screw. An insulating pad (40) is provided between the work turntable (39) and the support base (43). The middle part of the insulating pad (40) has a plate-like structure, and the edge is folded vertically downward on the outside of the work turntable (39).

[0021] In addition, the bottom surface of the work box (49) is an inclined surface that slopes from high to low in the direction away from the drain hole (47) and closer to the drain hole (47), and the inclination angle of the inclined surface is 8°.

[0022] In practical use, the following steps are included: 1. Install a pair of bearings (15) and oil baffle (16) at specific positions on the cathode clamp (10), then install the conductive copper sleeve (17) with the cathode clamp (10) through a mating relationship, and then install the cathode clamp (10) to the industrial robot execution end (9) through the flange (12). During installation, the bottom wall of the tool cathode (20) should be facing down and the top wall should be facing up. Connect the negative terminal of the electrolytic processing power supply to the conductive sleeve (17) through the cable and power connector (18), and connect the electrolyte pipeline to the pipe connector (14). 2. Install the workpiece (31) on the workpiece placement table (34) and further fix the workpiece (31) by pressing the plate (29). Then connect the positive terminal of the electrolytic processing power supply through the cable and connect the positive terminal of the power supply to the workpiece (31). 3. The workpiece (31) is precisely indexed by the rotary table (38), and then the industrial robot (6) is manually controlled to adjust the position of the tool cathode (20) with the tool setting device (35) as the reference, and the position after the tool setting is completed is set as the reference position; then the tool cathode (20) is fed to the initial processing position under the drive of the industrial robot (6); Fourth, under the action of the auxiliary light source (25), the industrial camera (26) collects the geometric features and defect information of the surface of the workpiece to be polished, generates a three-dimensional model of the workpiece surface, and plans the motion path of the industrial robot (6) and the relevant processing parameters in the processing process according to the three-dimensional model. Then, the electrolyte is added and the electrolytic processing power supply is turned on. The industrial robot (6) drives the tool cathode (20) to perform precise scanning motion according to the above-planned path to perform single-gradient electrochemical polishing; 5. After the local polishing of a single index is completed, the electrolytic processing power supply is disconnected and the supply of electrolyte is stopped. The industrial robot (6) drives the tool cathode (20) back to the initial position and uses an alcohol spray nozzle (24) to clean the residual electrolyte. Then, it is dried using a dryer (28). Subsequently, the industrial camera (26) collects surface information again to evaluate the polishing effect.

[0023] If the processing requirements are met, the rotary table (38) will drive the workpiece to be indexed, repeat steps three and four, and perform electrochemical polishing for the next index until all index polishing is completed; If the standard is not met, the industrial camera will collect the geometric features and defect information of the surface of the workpiece to be polished, extract the non-compliant area, and then plan the motion path of the industrial robot (6) and the relevant processing parameters in the processing process for the non-compliant area, and perform local electrochemical polishing until the polishing requirements are met.

[0024] During the processing, the electrolyte enters the inner cavity of the cathode fixture (10) through the electrolyte inlet pipe, flows into the tool cathode (20) through the electrolyte inlet, and then flows into the processing gap through the electrolyte outlet of each hole before falling into the bottom area of ​​the working box (49). Finally, it flows out through the drain hole (47), carrying away the electrolysis products and reaction heat. Attached Figure Description

[0026] Figure 1 Schematic diagram of a vision-guided electrochemical polishing system for complex-shaped integral components.

[0027] Figure 2 Schematic diagram of cathode clamp structure

[0028] Figure 3 Schematic diagram of the tool cathode structure.

Claims

1. A vision-guided electrochemical polishing system and method for complex-shaped integral components, characterized in that: The system comprises an image acquisition system (1), a motion control system (2), and a processing system (3). First, the image acquisition system (1) acquires the surface morphology of the workpiece. Then, the motion control system (2) plans the cathode motion trajectory based on the surface morphology and dynamically adjusts the processing parameters of different polishing areas during the polishing process. After the initial polishing is completed, the surface is cleaned using an alcohol spray nozzle (24) and a dryer (28). Then, the image acquisition system (1) acquires the surface morphology of the workpiece again. If the polishing meets the requirements, the next grade of polishing is performed. If the polishing does not meet the requirements, the motion control system (2) plans the cathode motion trajectory based on the surface morphology of the area that does not meet the requirements and dynamically adjusts the processing parameters of different polishing areas during the polishing process until the polishing requirements are met. With the synergistic effect of each system, the cathode motion trajectory can be planned and the processing parameters adjusted according to the specific situation in the surface morphology, thereby achieving high-quality electrochemical polishing of complex-shaped integral components.

2. The vision-guided electrochemical polishing system for complex-shaped integral components according to claim 1, characterized in that: The image acquisition system (1) includes an auxiliary light source (25), an industrial camera (26), an alcohol nozzle (24), and a dryer (28). The industrial camera (26) is provided with a transparent protective cover (27) on its upper part. The industrial camera (26), the alcohol nozzle (24), and the dryer (28) are located on the side wall of the work box (47), and the auxiliary light source (25) is located on the top wall of the work box (49).

3. The vision-guided electrochemical polishing system for complex-shaped integral components according to claim 1, characterized in that: The motion control system (2) includes an anode motion control system (4) and a cathode motion control system (5). The anode motion control system (4) includes a work box (49), a rotary worktable (38), and an anode positioning clamping device (32). The work box is provided with a mounting hole (48) and a drain hole (47). The anode positioning clamping device (32) includes a rotating spindle (33), a base plate (37), and a workpiece placement table (34). The rotating spindle (33) is vertically fixed to the base plate (37), and the upper part of the base plate (37) is provided with a tool setting device (35). The base plate (37) is bolted to the rotary worktable (38), and the workpiece placement table (34) is bolted to the base plate (37). The workpiece placement table (34) enables the workpiece to be positioned at the end face. The rotating spindle (33) can drive the workpiece to rotate synchronously through the pressure plate (29). The cathode motion control system (5) includes an industrial robot (6), a bellows cover (7), and a flexible protective cover (8). The bellows cover (7) is located at the mounting hole (48), and the flexible protective cover (8) is located in the middle of the bellows cover (7). The flexible protective cover (8) is connected to the flange through a hose clamp.

4. The vision-guided electrochemical polishing system for complex-shaped integral components according to claim 1, characterized in that: The processing system includes a tool cathode (20), a cathode clamp (10), and a workpiece (31). The cathode clamp (10) has a convex tubular structure, with a pipe connector (14) at the head of its horizontal tail section. The head of the horizontal tail section is closed and fixed to the industrial robot (6). The conductive copper sleeve (17) is press-fitted to the cathode clamp (10) through a bearing (15) and sealed to the outside of the horizontal tail section through an oil baffle (16). The vertical part of the cathode clamp (10) has a power connector (18). The electrolyte inlet pipe and cable are sealed and pass through the top of the side wall of the work box (49). The electrolyte inlet pipe is connected to the cathode clamp (10) through the pipe connector (14). The cable connects the negative terminal of the power supply to the conductive copper sleeve (17) through the power connector (18). The center lines of the horizontal head section, the horizontal tail section, and the pipe connector (14) of the cathode clamp (10) coincide.

5. The vision-guided electrochemical polishing system for complex-shaped integral components according to claim 1, characterized in that: The bottom wall (22) of the tool cathode (20) is a horizontal plane and the top wall is a straight groove-shaped thin tube structure. Its front end opening is the electrolyte inlet (21), and the rear end is closed. The horizontal top wall at the rear end is provided with various perforated electrolyte outlets. The remaining wall is insulated. The tool cathode (20) is positioned and engaged with the cathode clamp (10) through the front end round boss, and passes through the cathode clamp (10) and the conductive copper sleeve (17) along the axis. The side wall of the conductive copper sleeve (17) is perpendicular to the axis of the tool cathode (20) and is connected to the cathode set screw (19). The end of the cathode set screw (19) abuts against the bottom wall (22) of the tool cathode. The horizontal part of the cathode clamp (10), the conductive copper sleeve (17) and the tool cathode (20) are coaxially arranged.

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