Adaptive clamping method and device for workpiece in magnesium alloy micro-arc oxidation treatment

Abstract

The present application relates to a kind of magnesium alloy micro-arc oxidation processing in the self-adapting clamping method and device of workpiece, belong to intelligent manufacturing and metal surface treatment technical field, solve the poor general-purpose of fixture in prior art, the low level of each production unit cooperation, safety risk is outstanding and the process stability is artificially factor and the problem of improper heat management restriction.Method includes: obtaining the three-dimensional shape and through-hole feature of workpiece to be processed;According to through-hole feature, select titanium sheet type: no-hole workpiece selects the first type sheet with flat plate or micro-arc surface structure, and the second type sheet with circular truncated cone structure is selected for hole workpiece;Workpiece is clamped by clamp;Clamp is hung on gantry beam, after signal receiver installed at the bottom of insulated hook receives sensor trigger signal on beam, micro-arc oxidation power supply, conductive bow and circulating cooling system are synchronously triggered to start, and micro-arc oxidation processing is realized.The method realizes the self-adapting and intelligentization of clamping in magnesium alloy micro-arc oxidation processing.

Description

Technical Field

[0001] This invention relates to the fields of intelligent manufacturing and metal surface treatment technology, and in particular to an adaptive clamping method and apparatus for workpieces in the micro-arc oxidation process of magnesium alloys. Background Technology

[0002] Micro-arc oxidation technology is a key surface treatment technology for improving the corrosion resistance and wear resistance of magnesium alloys, and it is widely used in lightweight industrial fields such as aerospace and rail transportation. With the increasing demand for magnesium alloy components and the rising quality requirements in the high-end equipment manufacturing industry, the development of this technology from semi-automation to full automation has become an industry necessity.

[0003] In the industrial-scale micro-arc oxidation process, the workpiece, acting as the anode, needs to be immersed in the electrolyte through a fixture and connected to a high-voltage power supply of several hundred volts. Currently, the fixtures used in production are mostly special fixtures designed for specific workpieces. When the type of workpiece changes, the fixture needs to be replaced or adjusted, which is time-consuming. Clamping operations are mainly done manually, and the clamping force is controlled by experience. Poor contact can easily cause sparking, while excessive clamping may damage the workpiece surface.

[0004] Furthermore, the operation of the fixtures, the identification of the workpiece, and the temperature control of the electrolyte are usually performed independently by different personnel or equipment, with a lack of information exchange between them. Operators need to work at close range in high-pressure and corrosive environments, posing safety hazards. The micro-arc oxidation reaction generates a large amount of heat, causing the electrolyte temperature to rise, and large temperature fluctuations can affect the consistency of the film quality. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide an adaptive clamping method and apparatus for workpieces in the micro-arc oxidation process of magnesium alloys, so as to at least solve one of the problems in the existing methods, such as poor clamp versatility, low level of intelligent collaboration among production units, prominent safety risks, and process stability being constrained by human factors and improper thermal management.

[0006] Based on the above analysis, the present invention aims to provide an adaptive clamping method and apparatus for micro-arc oxidation of magnesium alloys, in order to solve at least one of the following problems in the prior art: poor clamp versatility, low level of coordination among production units, prominent safety risks, and process stability constrained by human factors and improper thermal management.

[0007] On one hand, embodiments of the present invention provide an adaptive clamping method for workpieces in the micro-arc oxidation process of magnesium alloys, comprising: S1. Obtain the three-dimensional shape and through-hole features of the workpiece to be processed; S2. Select the titanium sheet type according to the through hole characteristics: for workpieces without holes, select the first type of sheet with a flat plate or micro-arc surface structure; for workpieces with through holes, select the second type of sheet with a frustum structure. S3. Clamp the workpiece using a fixture; S4. The fixture holding the workpiece is suspended on the gantry beam. After the signal receiver installed at the bottom of the insulated hook receives the sensor trigger signal on the beam, the micro-arc oxidation power supply, conductive bow and circulating cooling system are simultaneously triggered to start, so as to realize the micro-arc oxidation treatment.

[0008] Furthermore, in S1, the three-dimensional shape and through-hole features are obtained through the recognition module on the fixture.

[0009] Furthermore, a controllable actuator is provided at the tail end of the spring, and the central control system adjusts the pre-compression of the spring through the controllable actuator to change the clamping force.

[0010] Furthermore, the clamp is a spring-return type clamp, and the steps for clamping the workpiece include: an external actuator presses the stainless steel connecting body of the clamp to open the clamp, moves it to the workpiece position and releases the pressing force, and the clamp closes under the action of the spring's rebound force to clamp the workpiece.

[0011] Furthermore, when the fixture picks up the workpiece, it automatically selects the clamping point based on the three-dimensional shape, avoiding machined surfaces and process holes.

[0012] Furthermore, S4 also includes a central control system that automatically determines the current value for micro-arc oxidation based on the workpiece surface area information obtained by the identification module.

[0013] Furthermore, after the workpiece is clamped, the recognition module detects whether the titanium sheet is aligned with the workpiece hole. If they are not aligned, the clamp position is adjusted by an external actuator until they are aligned. If they cannot be aligned, an alarm is triggered.

[0014] Furthermore, during the micro-arc oxidation process, the central control system controls the start / stop or flow rate of the circulating water system based on the temperature measurement signal inside the electrolytic cell.

[0015] Furthermore, in S4, after the micro-arc oxidation treatment is completed, the conductive bow is disconnected from the high-voltage line, the insulating hook is removed from the gantry beam, and the workpiece is removed.

[0016] On the other hand, embodiments of the present invention provide a smart micro-arc oxidation treatment device for magnesium alloys based on the above-described method, comprising: The clamp includes a clamp body, a clamping end, and a stainless steel connector. The stainless steel connector is fixedly connected to opposite sides of the clamp body and connected to the clamping end. The stainless steel connector is provided with a spring for controlling the opening and closing size of the clamp. A conductive bow, which penetrates the top surface of the clamp body and is electrically connected to the clamping end of the clamp; An insulated hook is provided, the upper end of which is fixedly installed on the top surface of the clamp body, and the lower end of which is provided with a sensing signal generating device for communicating with the sensor on the gantry beam. The identification module is installed on the bottom surface of the fixture body; The central control system is communicatively connected to the identification module, the conductive bow, the induction signal generator, and the circulating cooling system.

[0017] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1) This invention acquires the through-hole features of the workpiece through an identification module and automatically selects either a first-type or second-type piece based on the presence or absence of through holes. This allows the same fixture platform to quickly adapt to workpieces with different structures without requiring a complete fixture replacement. Using this method, when processing both perforated supports and perforated flanges, the changeover and re-clamping process can be completed within 30 seconds. This invention suspends an insulated hook on the gantry beam. After the sensor detects the positioning signal, it simultaneously triggers the start of the conductive bow, micro-arc oxidation power supply, and circulating cooling system, achieving linkage between clamping confirmation and process start-up. During micro-arc oxidation, the central control system controls the circulating water system in real time based on the temperature measurement signal inside the electrolytic cell, maintaining electrolyte temperature fluctuations within ±2℃. The electrolyte temperature can be controlled near any temperature point within the range of 20-30℃, with a fluctuation range far smaller than the 15℃ of traditional methods.

[0018] 2) This invention employs a spring-return clamp in conjunction with a controllable actuator to adjust the clamping force. The target clamping force is automatically set based on the workpiece material and structural characteristics using a pre-stored clamping force model. Simultaneously, the current value is automatically determined based on the workpiece surface area obtained by the identification module. This avoids arcing or indentation caused by manual clamping, ensuring the stability of micro-arc oxidation quality for workpieces of different sizes. The workpiece surface damage rate can be reduced to 0%, and the time to rust spots in salt spray testing can exceed 300 hours.

[0019] 3) After the workpiece is clamped, the present invention uses a laser displacement sensor to detect whether the titanium sheet is aligned with the workpiece hole. If it is not aligned, the clamp position is adjusted by an external actuator until it is aligned. If it cannot be adjusted, an alarm is triggered, thus avoiding poor contact caused by clamping position deviation.

[0020] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0021] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0022] Figure 1 This is a block diagram showing the composition and connection relationship of the intelligent micro-arc oxidation treatment device for magnesium alloys of the present invention. Figure 2 This is a three-dimensional structural diagram of the intelligent micro-arc oxidation treatment system for magnesium alloys of the present invention; Figure 3 For Figure 2 A schematic diagram of the overall three-dimensional structure of the fixture subsystem in the system; Figure 4 This is a side view of the fixture subsystem; Figure 5 A comparison diagram of the opening and closing of the clamping subsystem; Figure 6 This is an exploded view of the clamping end of the clamping system. Figure 7 These are schematic diagrams illustrating the structures of the two types of titanium sheets of this invention; Figure 8 This is a flowchart of the adaptive clamping method for workpieces in the micro-arc oxidation treatment of magnesium alloys according to the present invention.

[0023] Figure label: 1. High-voltage line; 2. Movable gantry frame; 3. Clamp; 4. Electrolyte treatment tank; 301. Conductive pantograph; 302. Telescopic cylinder; 303. Insulated hook; 304. Drive interface; 305. Clamp body; 306. Stainless steel connector; 307. Spring; 308. Wire; 309. Telescopic shaft; 310. Limiting rod; 311. Signal receiver; 312. Clamping end; 313. Rotary motor; 314. Identification module; 312-1. Titanium sheet; 312-2. Insulating frame; 312-3. Compression member; 312-1a. First type sheet; 312-1b. Second type sheet. Detailed Implementation

[0024] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0025] Micro-arc oxidation technology for magnesium alloys has attracted much attention due to its excellent surface strengthening effect. However, its industrial application has long been limited by problems such as poor fixture versatility, low production efficiency, insufficient process stability, and prominent safety hazards. In existing technologies, each subsystem is independent and cannot quickly adapt to the production needs of workpieces with different specifications. To address the above problems, embodiments of the present invention provide an adaptive clamping method and apparatus for micro-arc oxidation of magnesium alloys.

[0026] On one hand, a specific embodiment of the present invention discloses an adaptive clamping method for micro-arc oxidation treatment of magnesium alloys, such as... Figure 8 As shown, it includes the following steps: S1. Obtain the three-dimensional shape and through-hole features of the workpiece to be processed; S2. Select the titanium sheet type according to the through hole characteristics: for workpieces without holes, use the first type sheet 312-1a; for workpieces with through holes, use the second type sheet 312-1b. S3. Clamp the workpiece using fixture 3; S4. The clamp 3 for gripping the workpiece is suspended on the crossbeam of the gantry frame. After the signal receiver 311 installed at the bottom of the insulating hook 303 receives the sensor trigger signal on the crossbeam, the conductive bow 301, the micro-arc oxidation power supply and the circulating cooling system are simultaneously triggered to start.

[0027] It should be noted that adaptive clamping refers to the system's ability to automatically select the appropriate titanium plate type based on the workpiece's geometric characteristics, especially the presence or absence of through holes, and complete the clamping action through the cooperation of the robotic arm and the fixture. The titanium plate can be an independent component detachably mounted on the fixture body, or it can be integrally set with the fixture body or fixedly connected to it as an integral fixture. The appropriate type of titanium plate is selected and configured at the working end of the fixture according to the workpiece's different through hole characteristics. For example, multiple types of titanium plates can be prepared to share a single fixture body, or multiple sets of fixtures can be prepared, each with different types of titanium plates fixed at its working end.

[0028] Compared with the prior art, the method provided in this embodiment enables the fixture to be quickly adapted to workpieces with different structures by using through hole features and titanium sheet selection, avoiding the time-consuming operation of manually changing the fixture; by synchronously triggering the power supply and cooling through the hook positioning signal, it ensures that the process is in a thermally stable state at the initial stage, thereby improving clamping efficiency, process stability and operational safety.

[0029] Specifically, in S1, the fixture 3 is equipped with an identification module 314. Before the operation begins, the fixture 3 moves along a predetermined path with the gantry beam, and the identification module 314 scans and identifies the workpiece to be processed, obtaining the workpiece's three-dimensional shape and through-hole features. This method does not require additional fixed identification and detection equipment, and the gantry's travel trajectory can be flexibly adjusted, making it particularly suitable for scenarios where the workpiece's placement position is not fixed.

[0030] For example Figure 6As shown, the clamping end 312 adopts a quick-change interface design and mainly consists of a titanium sheet 312-1, an insulating frame 312-2, and a pressing member 312-3. The titanium sheet 312-1 is detachably installed inside the insulating frame 312-2, and the pressing member 312-3 passes through the insulating frame to press and fix the titanium sheet 312-1. Specifically, the pressing member 312-3 is a hollow bolt made of polytetrafluoroethylene, with a wire 308 passing through it; when the bolt is tightened, the end of the bolt presses against the internal copper disc, which can firmly press the titanium sheet 312-1 inside the insulating frame 312-2, while ensuring the stability of the electrical connection.

[0031] Because titanium sheet 312-1 is immersed in electrolyte and carries high voltage for extended periods, it is prone to surface oxidation, corrosion, and wear. Therefore, titanium sheet 312-1 is designed as a detachable structure. When replacing titanium sheet 312-2, only the compression component 312-3 needs to be loosened to complete the replacement, without the need for complete disassembly and replacement of the clamping end 312, thus reducing the cost of consumable replacement.

[0032] For different workpiece shapes, titanium sheet 312-1 offers two configurations, such as... Figure 7 As shown: Type 1 plate 312-1a: Flat or micro-arc surface structure, suitable for clamping workpieces without holes or with flat surfaces, can provide a larger contact area and reduce contact resistance; Type 2 plate 312-1b: The front end has a frustum structure, suitable for workpieces with through holes. When clamped, the frustum structure is embedded in the through hole, and its conical surface forms line contact or small surface contact with the edge of the hole. For through holes with diameters ranging from 5mm to 15mm, this frustum structure can adaptively fit the edges of different hole diameters, eliminating the need to design a separate titanium plate for each hole diameter.

[0033] Furthermore, the clamp 3 is a spring-return type clamp, including a clamp body 305, a clamping end, and a stainless steel connector 306. The stainless steel connector 306 is a symmetrically arranged frame-type component, fixedly connected to the opposite side walls of the clamp body 305, with its middle end fixedly connected to the clamp body 305, and its lower end extending downward and connecting to the clamping end 312, forming a traction structure for the clamping end 312; A spring 307 is provided in the inner space of the stainless steel connector 306. One end of the spring 307 abuts against the side wall of the clamp body 305, and the other end abuts against the lower part of the stainless steel connector 306. The opening and closing size of the clamp 3 is controlled by the elastic deformation of the spring, and a reset elastic force is provided for the clamping action. The stainless steel connector 306 has a drive interface 304 on its top. An external actuator can engage with the drive interface 304 and apply pressure to make the stainless steel connector 306 open against the elastic force of the spring 307. The telescopic shaft 309 extends and retracts synchronously with the gripper. The limit rod 310 is used to limit the maximum opening range of the clamp to avoid excessive opening and closing and structural damage. The clamping end 312 is a symmetrically arranged block structure. The opening and closing guidance and stroke limitation are realized by the telescopic shaft 309 and the limiting rod 310. The clamping and release of the workpiece are completed under the cooperative action of the stainless steel connector 306 and the spring 307.

[0034] In addition, the fixture also includes a conductive pantograph 301, an insulating hook 303, an identification module 314, and a central control system. One end of the conductive pantograph 301 is connected to a high-voltage power supply 1, and the other end passes through the top surface of the fixture body 305 and is electrically connected to the clamping end of the fixture 3. The upper end of the insulating hook 303 is fixedly installed on the top surface of the fixture body 305, and the lower end of the insulating hook 303 is provided with an induction signal generating device for communicating with the sensor on the gantry beam. The identification module 314 is installed on the bottom surface of the fixture body 305. The central control system is communicatively connected to the identification module 314, the conductive pantograph 301, the induction signal generating device, and the circulating cooling system.

[0035] The steps for clamping the workpiece include: the external actuator squeezes the stainless steel connector 306 of the clamp 3 to open the clamp 3, and after moving to the workpiece position, the squeezing force is released, and the clamp 3 closes to clamp the workpiece under the action of the spring 307.

[0036] like Figure 5 As shown, the system applies or releases pressure to the clamp 3 through an external actuator to open and close the clamp, thereby completing the workpiece pick-up and drop operation.

[0037] Furthermore, when clamping the workpiece, fixture 3 automatically selects the clamping point based on the three-dimensional shape, avoiding machined surfaces and process holes. While acquiring the three-dimensional shape of the workpiece, the identification module can identify the machined surfaces (such as finished surfaces and mating surfaces) and process holes (such as positioning holes, threaded holes, and through holes). Based on this information, the central control system automatically selects the clamping position, prioritizing non-machined surfaces or rough surfaces as clamping points to avoid indentations or scratches on machined surfaces, while also preventing blockage or damage to process holes.

[0038] Furthermore, such as Figure 4 As shown, after the workpiece is clamped, the titanium sheet 312-1 forms the optimal contact posture with the workpiece clamping surface; at the same time, the central control system automatically determines the current value of micro-arc oxidation based on the workpiece surface area information obtained by the identification module 314.

[0039] In micro-arc oxidation processes, current density is a key parameter determining the quality and thickness distribution of the film. Due to the significant differences in surface area among different workpieces, if a fixed current value is used, the current density will be insufficient for workpieces with large surface areas, resulting in slow film growth or even failure to form a film. On the other hand, if the current density is too high for workpieces with small surface areas, it may lead to localized ablation or a porous film.

[0040] This solution uses the recognition module 314 to scan the three-dimensional shape of the workpiece, calculate its surface area, and transmit the surface area data to the central control system. The central control system automatically calculates the required process current value by multiplying the preset target current density value by the workpiece surface area, and outputs this value during the micro-arc oxidation process.

[0041] Furthermore, after the workpiece is clamped, the identification module 314 detects whether the titanium sheet 312-1 is aligned with the workpiece hole. If it is not aligned, the position of the clamp 3 is adjusted by the external actuator until it is aligned; if it cannot be adjusted to be aligned, an alarm is triggered.

[0042] For example, the identification module 314 integrates a laser displacement sensor. This sensor emits a laser beam towards the titanium sheet 312-1 and the edge of the workpiece hole, and determines whether the two are aligned by measuring the distance difference or the abrupt change in the reflected light intensity. If an offset is detected, the central control system sends an adjustment command to the external actuator to fine-tune the position of the fixture 3 until the alignment conditions are met. If alignment still cannot be achieved after multiple adjustments, the system determines that there may be workpiece dimensional errors, incorrect titanium sheet installation, or other abnormalities, and then issues an audible and visual alarm to prompt operator intervention.

[0043] Furthermore, a controllable actuator is provided at the tail end of the spring 307. The central control system adjusts the pre-compression of the spring 307 through the controllable actuator to change the clamping force.

[0044] Specifically, the central control system calculates the target clamping force based on the workpiece material (such as AZ31B or AZ91D) and structural characteristics (such as thin-walled or solid parts) obtained by the identification module 314, using a pre-stored clamping force model. It then controls the controllable actuator to adjust the spring pre-compression to achieve this target. This method allows for the use of smaller clamping forces on thin-walled parts to avoid damage, and larger clamping forces on thick-walled parts to ensure reliable contact, thus balancing the dual requirements of preventing damage and arcing.

[0045] The clamping force model can be implemented in the following ways: First, based on a rule-based empirical database, pre-set corresponding clamping force ranges for different grades of magnesium alloys (such as AZ31B and AZ91D) and different structural features (such as thin-walled parts, solid parts, and parts with holes). For example, for AZ31B thin-walled cylindrical parts, the model outputs a force range of 50N-70N; for AZ91D solid blocks, it outputs a force range of 100N-150N. Second, based on a machine learning-based predictive model, the optimal clamping force value is automatically output by inputting the visual feature parameters of the workpiece.

[0046] Furthermore, such as Figure 2 As shown, the electrolytic cell 4 is designed with a hollow cavity structure around its perimeter. Circulating cooling water flows within the cavity, exchanging heat with the electrolyte to achieve heat dissipation. During the micro-arc oxidation process, the central control system controls the start / stop or flow rate of the circulating water system based on the temperature measurement signal inside the electrolytic cell 4.

[0047] Micro-arc oxidation is a strongly exothermic process. If the heat cannot be dissipated in time, the electrolyte temperature will continue to rise, causing the film to become porous and its corrosion resistance to decrease. It also accelerates the decomposition and failure of the electrolyte components. Therefore, a temperature sensor is installed inside the electrolytic cell 4 to monitor the electrolyte temperature in real time and transmit the signal to the central control system. The central control system uses a PID control algorithm to compare the measured temperature with the set value. Based on the deviation signal, it controls the opening of the solenoid valves in the circulating water system or the speed of the variable frequency pump, thereby adjusting the cooling water flow rate: when the electrolyte temperature is higher than the set value, the cooling water flow rate is increased; when the temperature is lower than the set value, the cooling water flow rate is decreased or stopped; when the temperature exceeds the safe range, the system can issue an alarm and suspend the process.

[0048] The above solution can control the electrolyte temperature fluctuation within ±2℃, providing a stable thermal environment for the micro-arc oxidation reaction, which is conducive to the formation of a dense, uniform, and high-hardness ceramic film layer, while extending the service life of the electrolyte and reducing production costs.

[0049] Furthermore, after the micro-arc oxidation treatment is completed, the conductive bow 301 is disconnected from the high-voltage line 1, the insulating hook 303 is removed from the gantry beam, and the workpiece is removed.

[0050] Specifically, after the micro-arc oxidation process is completed, the central control system first issues a disconnect command to the conductive pantograph 301, disconnecting it from the high-voltage line 1. Then, the external actuator moves to the gantry 2, picks up the insulated hook 303, removes the clamp 3 from the crossbeam, and moves it to the workpiece placement point. Finally, the external actuator squeezes the stainless steel connector 306 to open the clamp 3, releasing the workpiece and completing the entire processing flow.

[0051] On the other hand, a specific embodiment of the present invention discloses a smart micro-arc oxidation treatment device for magnesium alloys based on the method described above. For example... Figure 1 As shown in the overall architecture diagram, the device consists of a central control system, fixture 3, electrolyte treatment tank 4, micro-arc oxidation power supply, and external actuators; its specific mechanical structure is as follows: Figures 2 to 7 As shown, it includes: The clamp 3 includes a clamp body 305, a clamping end and a stainless steel connector 306. The stainless steel connector 306 is fixedly connected to the opposite sides of the clamp body 305. The stainless steel connector 306 is connected to the clamping end. The stainless steel connector 306 is provided with a spring to control the opening and closing size of the clamp 3. The conductive bow 301 has one end for connecting to the high voltage 1, and the other end passes through the top surface of the clamp body 305 and is electrically connected to the clamping end of the clamp 3. An insulating hook 303 is provided, the upper end of which is fixedly installed on the top surface of the clamp body 305, and the lower end of which is provided with a sensing signal generating device for communicating with the sensor on the gantry beam. The identification module 314 is installed on the bottom surface of the fixture body 305; The central control system is communicatively connected to the identification module 314, the conductive bow 301, the induction signal generator, and the circulating cooling system.

[0052] Specifically, the clamping fixture 3 has a clamping end 312 on its inner side, and a titanium sheet 312-1 is embedded inside the clamping end 312. The non-clamping surface of the titanium sheet 312-1 is covered with an insulating frame 312-2. The pressing member 312-3 cooperates with the titanium sheet 312-1 to complete the workpiece clamping and positioning. The titanium sheet 312-1 includes a first type sheet 312-1a and a second type sheet 312-1b, which can be flexibly adapted and clamped according to the through hole characteristics of the workpiece. The upper part of the clamping fixture 3 is also provided with a telescopic cylinder 302. The telescopic cylinder 302 drives the clamping action through the telescopic shaft 309. The spring 307 cooperates with the limit rod 310 to realize clamping buffer and limit constraint. The stainless steel connector 306 is used to realize the stable assembly between various mechanical components.

[0053] The internal wires of the conductive bow 301 pass through the top surface of the clamp body 305 and are electrically connected to the titanium sheet 312-1 of the clamping end 312. The top of the conductive bow 301 is directly connected to the high-voltage line 1. The clamp body 305 is an insulating cavity. The identification module 314 is installed on the bottom surface of the clamp body 305. The identification module 314 works with the signal receiver 311 to complete the acquisition of workpiece information. The rotary motor 313 is used to drive the conductive bow 301 to move, so as to control its contact and separation from the high-voltage line 1. When the insulating hook 303 is suspended on the gantry beam, the sensor on the beam receives the sensing signal at its bottom and transmits it to the central control system.

[0054] The present invention will be described in more detail below through specific embodiments. These embodiments are merely descriptions of the best implementation of the invention and do not limit the scope of the invention in any way.

[0055] Example 1 The intelligent micro-arc oxidation treatment device for magnesium alloys used in this embodiment includes: The clamp 3 includes a clamp body 305, a clamping end and a stainless steel connector 306. The stainless steel connector 306 is fixedly connected to the opposite sides of the clamp body 305. The stainless steel connector is connected to the clamping end. The stainless steel connector 306 is provided with a spring to control the opening and closing size of the clamp 3. In addition, the fixture also includes a conductive pantograph 301, an insulating hook 303, an identification module 314, and a central control system. One end of the conductive pantograph 301 is connected to a high-voltage power supply 1, and the other end passes through the top surface of the fixture body 305 and is electrically connected to the clamping end of the fixture 3. The upper end of the insulating hook 303 is fixedly installed on the top surface of the fixture body 305, and the lower end of the insulating hook 303 is provided with an induction signal generating device for communicating with the sensor on the gantry beam. The identification module 314 is installed on the bottom surface of the fixture body 305. The central control system is communicatively connected to the identification module 314, the conductive pantograph 301, the induction signal generating device, and the circulating cooling system.

[0056] This embodiment processes a batch of AZ31B magnesium alloy thin-walled supports (without through holes). The processing procedure is as follows: S1. Obtain the three-dimensional shape and through-hole features of the workpiece to be processed, and automatically select the clamping point according to the three-dimensional shape to avoid the machined surface and process holes.

[0057] S2. Select the titanium sheet type according to the characteristics of the through hole: Select the first type sheet 312-1a for workpieces without holes, and select the second type sheet 312-1b for workpieces with through holes. In this embodiment, the first type sheet 312-1a is a flat plate structure.

[0058] S3. The workpiece is clamped by the fixture 3. The specific steps are as follows: the external actuator squeezes the stainless steel connector 306 of the fixture 3 to open the fixture 3. After moving to the workpiece position, the squeezing force is released, and the fixture 3 closes to clamp the workpiece under the action of the spring 307. A controllable actuator is provided at the tail end of the spring 307. The central control system adjusts the pre-compression of the spring 307 through the controllable actuator to change the clamping force. In this embodiment, the clamping force is set to 60N. After clamping, the identification module 314 detects whether the titanium sheet 312-1 is aligned with the workpiece hole. After confirming the alignment, the process continues.

[0059] S4. The clamp 3 for gripping the workpiece is suspended on the gantry beam. After the sensor detects the signal that the insulating hook 303 is in position, the micro-arc oxidation power supply and the circulating cooling system are started simultaneously. The central control system automatically determines the micro-arc oxidation current value based on the workpiece surface area information obtained by the identification module 314. In this embodiment, the current value is set to 1.5A. During the micro-arc oxidation process, the central control system controls the start / stop or flow rate of the circulating water system based on the temperature measurement signal inside the electrolytic cell 4 to control the electrolyte temperature at 25±1°C. After the micro-arc oxidation process is completed, the conductive bow 301 is disconnected from the high-voltage line 1, the insulating hook 303 is removed from the gantry beam, and the workpiece is removed.

[0060] Example 2 This embodiment uses the same apparatus as in Embodiment 1 to process a batch of AZ91D magnesium alloy flanges (with φ10mm mounting through holes).

[0061] The only difference between the processing procedure and Example 1 is that: In S2, since the workpiece has a through hole, the second type of plate 312-1b (frustum structure) is selected. When clamping, the frustum structure adaptively embeds into the through hole and forms surface contact with the edge of the hole.

[0062] In S3, the clamping force is set to 120N based on the workpiece material AZ91D and the flange structure.

[0063] In S4, the micro-arc oxidation voltage is 550V, the time is 12 minutes, and the electrolyte temperature is controlled at 28±1.5°C.

[0064] The remaining steps are the same as in Example 1.

[0065] After processing, there were no signs of arcing or burning at the contact points of the workpiece, and no indentations on the precision-machined surface of the flange.

[0066] Example 3 This embodiment uses the same apparatus as Embodiment 1 to mix and process the brackets of Embodiment 1 and the flanges of Embodiment 2 on a production line.

[0067] The only difference between the processing procedure and Example 1 is that: The central control system automatically schedules the robotic arm based on the identification result of the next workpiece by the identification module in the loading area: if the next workpiece is a non-perforated bracket, the first type of sheet 312-1a is retained; if it is a perforated flange, the robotic arm automatically moves to the tool station before clamping and replaces the titanium sheet with the second type of sheet 312-1b through the quick-change interface. The changeover and re-clamping process is completed within 30 seconds.

[0068] For non-perforated supports, follow steps S1-S4 of Example 1; for perforated flanges, except that the titanium sheet type is selected as the second type 312-1b, the other steps are the same as in Example 1, and the electrolyte temperature is controlled at 25±2°C during the micro-arc oxidation process.

[0069] All workpieces were processed within an electrolyte temperature window of 25±2°C.

[0070] Comparative Example 1 The AZ31B bracket, identical to that in Example 1, was handled using a traditional manual bolt-tightening titanium clamp. The operation was manual. During processing, a slight loosening of the clamp caused sparking, resulting in burnt-out of the workpiece contact point. Simultaneously, the electrolyte used an external cooling coil with natural circulation, allowing for temperature fluctuations of up to 15°C (from 25°C to 40°C).

[0071] Comparative Example 2 The AZ91D flange, processed using the same conventional fixtures as in Example 2, was subjected to excessive tightening of bolts to prevent sparking, resulting in noticeable indentations on the finished flange surface. Electrolyte temperature control was also poor, fluctuating by approximately 12°C.

[0072] Characterization results and analysis The characterization results of the above-described embodiments and comparative examples are shown in Table 1 below.

[0073] Table 1. Comparison of Micro-arc Oxidation Film Performance and Production Data

[0074] As shown in Table 1, the microhardness of the micro-arc oxidation film in Examples 1-3 of this invention is 650-720 HV, and the rust-free time in the salt spray test is greater than 300-360 h. In contrast, the microhardness of the comparative film is only 480-550 HV, and the rust initiation time in the salt spray test is only 120-150 h. Therefore, it can be concluded that the oxide film prepared by this invention is significantly superior to the comparative examples prepared by conventional processing methods in terms of both hardness and corrosion resistance.

[0075] Meanwhile, the present invention eliminates defects such as burns and clamping marks caused by manual clamping through intelligent clamping, and the surface damage rate of the workpiece is kept stable at 0%. Relying on automated operation and quick changeover structure, the single-piece processing cycle is controlled at 3.5~4.2 min, which is more than half the processing time of the comparative example of 8.0~8.5 min, greatly improving the processing efficiency and yield of magnesium alloy workpiece micro-arc oxidation.

[0076] In summary, this invention successfully constructs an efficient, high-quality, safe, and flexible intelligent production system for micro-arc oxidation of magnesium alloys, and provides corresponding methods, offering an effective technical solution to overcome the industrialization bottleneck of this technology.

[0077] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A self-adaptive clamping method for workpiece in magnesium alloy micro-arc oxidation treatment, characterized in that, include: S1. Obtain the three-dimensional shape and through-hole features of the workpiece to be processed; S2. Select the type of titanium sheet (312-1) according to the through hole characteristics: for workpieces without holes, select the first type of sheet (312-1a) with a flat plate or micro-arc surface structure, and for workpieces with through holes, select the second type of sheet (312-1b) with a frustum structure. S3. Clamp the workpiece using the fixture (3); S4. The fixture (3) holding the workpiece is suspended on the crossbeam of the gantry frame. After the signal receiver (311) installed at the bottom of the insulating hook (303) receives the sensor trigger signal on the crossbeam, the micro-arc oxidation power supply, the conductive bow (301) and the circulating cooling system are simultaneously triggered to start, so as to realize the micro-arc oxidation treatment.

2. The method of claim 1, wherein, In S1, the three-dimensional shape and through-hole features are obtained by the recognition module (314) on the fixture (3).

3. The method of claim 1, wherein, The clamp (3) is a spring-reset type clamp. The steps of clamping the workpiece include: the external actuator squeezes the stainless steel connector (306) of the clamp (3) to open the clamp (3), and after moving to the workpiece position, the squeezing force is released. The clamp (3) closes and clamps the workpiece under the action of the spring (307).

4. The method of claim 3, wherein, A controllable actuator is provided at the tail end of the spring (307). The central control system adjusts the pre-compression of the spring (307) through the controllable actuator to change the clamping force.

5. The method of claim 1, wherein, When the fixture (3) clamps the workpiece, it automatically selects the clamping point according to the three-dimensional shape and avoids the machined surface and process hole.

6. The method of claim 1, wherein, S4 also includes a central control system that automatically determines the current value for micro-arc oxidation based on the workpiece surface area information obtained by the identification module (314).

7. The method according to claim 6, characterized in that, After the workpiece is clamped, the identification module (314) detects whether the titanium sheet (312-1) is aligned with the workpiece hole. If it is not aligned, the position of the clamp (3) is adjusted by the external actuator until it is aligned. If it cannot be adjusted to be aligned, an alarm is triggered.

8. The method according to claim 1, characterized in that, During the micro-arc oxidation process, the central control system controls the start-up or flow rate of the circulating water system based on the temperature measurement signal inside the electrolytic cell (4).

9. The method according to claim 1, characterized in that, S4 also includes the following steps: after the micro-arc oxidation treatment is completed, the conductive bow (301) is disconnected from the high-voltage line (1), the insulating hook (303) is removed from the gantry beam, and the workpiece is removed.

10. A smart micro-arc oxidation treatment device for magnesium alloys based on the method of any one of claims 1 to 9, characterized in that, include: The clamp (3) includes a clamp body (305), a clamping end and a stainless steel connector (306). The stainless steel connector (306) is fixedly connected to the opposite sides of the clamp body (305). The stainless steel connector (306) is connected to the clamping end. The stainless steel connector (306) is provided with a spring to control the opening and closing size of the clamp (3). Conductive bow (301), the conductive bow (301) penetrates the top surface of the clamp body (305) and is electrically connected to the clamping end of the clamp (3); An insulating hook (303) is fixedly installed at its upper end on the top surface of the clamp body (305). The lower end of the insulating hook (303) is provided with a sensing signal generating device for communicating with the sensor on the gantry beam. The identification module (314) is installed on the bottom surface of the fixture body (305); The central control system is communicatively connected to the identification module (314), the conductive bow (301), the induction signal generator, and the circulating cooling system.

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