Production line precision control system for improving consistency of electrode foil oxidation film

Abstract

The invention discloses a production line precision control system for improving the consistency of an electrode foil oxidation film, and relates to the technical field of anodic oxidation, a foil releasing unit, a multi-section formation unit, an intermediate processing unit, a roasting repairing unit, a drying unit and a foil collecting unit are sequentially arranged in the electrode foil conveying direction; the foil releasing unit is provided with a conductive roller for electrifying the electrode foil; the multiple sections of formation units corrode and oxidize electrode foils in sections through alternate arrangement of positive and negative electrode grooves, so that oxidation films are layered and stacked, and the thickness and the density are improved; the middle treatment unit enhances the water resistance of the oxidation film through phosphoric acid treatment; the roasting repairing unit realizes multi-stage heat treatment and multi-stage oxidation repairing, so that the structural integrity of the film layer is improved; the drying unit realizes surface drying; the foil collecting unit controls electrode foil conveying through constant tension, and the stability of the treatment process is improved; through whole-process parameter control and film layer segmentation optimization, the uniformity, compactness and reliability of the oxidation film are improved, and the problem that the consistency of the oxidation film is reduced easily due to existing electrode foil oxidation control is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of anodic oxidation, and particularly relates to a precision control system for a production line for improving the consistency of an oxide film of an electrode foil. Background Art

[0002] As a high-performance component widely used in modern electronic devices, the performance of a solid aluminum electrolytic capacitor highly depends on the quality and consistency of the oxide film of the electrode foil. At present, the manufacturing technology of the electrode foil mainly develops along two directions: one is the high specific capacitance and high-strength electrochemical corrosion technology for improving the capacitance value per unit area; the other is the anodic oxidation technology for achieving high consistency, high reliability, and high lead-out efficiency of the oxide film; compared with the former, the latter more directly affects the electrical performance stability and service life of the capacitor, and thus has been increasingly emphasized.

[0003] Currently, in anodic oxidation treatment, low-pressure etched aluminum foil is widely used to conduct electricity in a high-conductivity forming solution, so that an oxide film with a high dielectric constant is formed on the aluminum surface to improve the energy storage capacity. However, existing forming equipment generally has problems such as a closed structure, a delay in parameter feedback, and a rough process control, resulting in inaccurate control of key process parameters such as voltage, current density, temperature, and forming solution concentration during the oxidation process, thereby affecting the quality of the oxide film; especially in the multi-stage forming process, parameter fluctuations are likely to cause phenomena such as uneven oxide film thickness, shrinkage deformation, and a decrease in dielectric properties, further affecting the appearance, withstand voltage performance, and mechanical strength of subsequent products.

[0004] In addition, the oxide film formation process has typical non-linear and dynamic characteristics, and there are significant differences in the reaction rate and film formation mechanism under different forming solution systems, which puts higher requirements on the real-time response ability and multi-parameter coordinated regulation ability of the control system; most existing domestic forming systems adopt a fixed-value control method, lacking the ability of refined identification and response regulation of the full-process dynamic state of the electrode foil, and it is difficult to achieve synchronous and stable control of process parameters in each section.

[0005] More prominently, in actual production, due to the lack of a multi-parameter precision monitoring and feedback system for the entire process of anodic oxidation of the electrode foil, the process conditions such as temperature, voltage, and current density in each section cannot be adjusted in real-time and closed-loop, often causing problems such as poor consistency of the oxide film, large fluctuations in dielectric constant, and low product yield.

[0006] At the same time, current forming equipment generally lacks the ability to immediately diagnose and handle abnormal working conditions such as current mutation, local overheating, and deterioration of the forming solution, which is not conducive to the stable formation of a high-quality composite oxide film.

[0007] The following technical problems are found in the existing technology: First, the control of multi-segment parameters during the anodic oxidation process lacks precision and it is difficult to meet the requirements for high-consistency film formation; second, there is a lack of a highly responsive online monitoring and feedback mechanism, and intelligent regulation under dynamic operating conditions cannot be achieved; third, the ability to identify abnormal states is insufficient, which easily leads to fluctuations in the performance of the oxide film and a decrease in product consistency.

[0008] Therefore, there is an urgent need to develop a production line control system with the capabilities of multi-parameter precision control, real-time monitoring and feedback, and abnormal state recognition, so as to effectively improve the quality and film formation consistency of the electrode foil oxide film.

[0009] In summary, it is found that the existing technology has at least the following technical problems:

[0010] In the existing control of electrode foil oxidation, there are technical problems such as low precision in the control of multi-segment parameters during the oxidation process, inability to achieve intelligent regulation under dynamic operating conditions, and insufficient ability to identify abnormal states during the oxidation process, which easily lead to fluctuations in the performance of the oxide film and a decrease in product consistency. Summary of the Invention

[0011] The purpose of the present invention is to provide a precision control system for a production line that improves the consistency of the electrode foil oxide film, so as to solve the technical problems in the existing control of electrode foil oxidation, including low precision in the control of multi-segment parameters during the oxidation process, inability to achieve intelligent regulation under dynamic operating conditions, and insufficient ability to identify abnormal states during the oxidation process, which easily lead to fluctuations in the performance of the oxide film and a decrease in product consistency.

[0012] The many technical effects that can be produced by the preferred technical solutions among the many technical solutions provided by the present invention are described in detail below.

[0013] To solve the above technical problems, the present invention provides the following technical solutions:

[0014] The present invention provides a precision control system for a production line to improve the consistency of the oxide film of an electrode foil, which includes a foil feeding unit arranged sequentially along the conveying direction of the electrode foil. A squirrel-cage conductive roller is installed in the foil feeding unit for energizing the electrode foil during foil feeding; and a multi-stage formation unit, which includes a negative electrode tank, a positive electrode tank, and a negative electrode tank arranged sequentially along the conveying direction of the electrode foil, and performs multi-stage anodic oxidation treatment on the electrode foil to generate corrosion and the growth of the oxide film in a layered manner on the surface of the electrode foil; and a middle treatment unit, which includes a phosphoric acid tank and a first water washing tank. The phosphoric acid tank is used to convert the oxide film formed on the electrode foil into a water-resistant composite oxide film, preventing oxygen-containing substances from migrating into the interior of the oxide film and avoiding the formation of porous aluminum hydroxide; and a first roasting and repairing unit, which first roasts and performs anodic oxidation treatment on the electrode foil to repair the oxide film; and a second roasting and repairing unit, which performs secondary roasting on the electrode foil and then performs secondary anodic oxidation treatment; the first roasting and repairing unit and the second roasting and repairing unit perform hierarchical high-temperature treatment on the oxide film of the electrode foil to achieve hierarchical transformation of the crystals of the oxide film on the surface of the electrode foil, and then repair the defective parts of the oxide film by hierarchical anodic oxidation treatment; and a drying unit, which dries the surface of the electrode foil at a high temperature; and a foil receiving unit, which is used to automatically adjust the winding speed of the electrode foil to keep the electrode foil conveyed at a constant tension in the multi-stage formation unit, the middle treatment unit, the first roasting and repairing unit, the second roasting and repairing unit, and the drying unit, so that the formation treatment of the electrode foil is more stable, and the formation of the oxide film is more uniform and dense.

[0015] In one embodiment, the foil feeding unit includes a foil feeding machine and a foil feeding buffer rack; the foil feeding machine releases the electrode foil, and the electrode foil sequentially passes through the foil feeding buffer rack, the multi-stage formation unit, the middle treatment unit, the first roasting and repairing unit, the second roasting and repairing unit, and the drying unit, and finally enters the foil receiving unit. The foil feeding buffer rack cooperates with the foil receiving unit to apply a constant tension to the conveyed electrode foil to prevent the electrode foil from being stretched or compressed during the conveying process.

[0016] In one embodiment, a switching power supply is further arranged on the conductive roller and the multi-stage formation unit; the conductive roller is arranged between the foil feeding buffer rack and the multi-stage formation unit, and the conductive roller is connected to the positive pole of the switching power supply and receives a current of 700 A.

[0017] In one embodiment, the conductive roller is composed of a central copper column and an aluminum conductive comb; the aluminum conductive comb is arranged in a circumferential array around the outer circumference of the central copper column, and a silver layer is plated on the surface of the aluminum conductive comb in contact with the electrode foil to increase the resistance between the conductive roller and the electrode foil and reduce the heat generated by the conductive roller and the electrode foil; a water-cooling cavity is arranged between the aluminum conductive comb and the central copper column to remove the heat generated by the electric shock rod through water cooling, reduce the heat transferred from the conductive roller to the electrode foil, and reduce the temperature rise at the contact between the electrode foil and the conductive roller.

[0018] In one embodiment, there are four negative electrode grooves, including a first negative electrode groove, a second negative electrode groove, a third negative electrode groove, and a fourth negative electrode groove; among them, the first negative electrode groove, the second negative electrode groove, the third negative electrode groove, the positive electrode groove, and the fourth negative electrode groove are arranged in sequence along the conveying direction of the electrode foil; after the electrode foil enters the multi-stage forming unit, it passes through the first negative electrode groove, the second negative electrode groove, the third negative electrode groove, the positive electrode groove, and the fourth negative electrode groove in sequence; the first negative electrode groove, the second negative electrode groove, the third negative electrode groove, and the fourth negative electrode groove are respectively connected to the negative electrode of the switching power supply and receive a current of 250A; the positive electrode groove is connected to the positive electrode of the switching power supply and receives a current of 300A.

[0019] In one embodiment, after the electrode foil flows out of the fourth negative electrode groove, it enters the phosphoric acid tank and the first water washing tank in sequence; a lifter is installed in the phosphoric acid tank, and the telescopic end of the lifter is connected to the roller shaft that guides the conveying of the electrode foil in the phosphoric acid tank to control the contact height between the oxide film on the surface of the electrode foil entering the phosphoric acid tank and the liquid in the phosphoric acid tank, so that the oxide film on the surface of the electrode foil rises and falls with the liquid level in the phosphoric acid tank.

[0020] In one embodiment, the first roasting and repair unit includes a first roasting furnace, a first repair tank, and a second water washing tank; after the electrode foil flows out of the second water washing tank, it enters the first roasting furnace, the first repair tank, and the second water washing tank in sequence.

[0021] In one embodiment, the second roasting and repair unit includes a second roasting furnace, a second repair tank, and a third water washing tank; after the electrode foil flows out of the third water washing tank, it enters the second roasting furnace, the second repair tank, and the third water washing tank in sequence.

[0022] In one embodiment, the foil winding unit includes an automatic foil winder, a foil winding buffer rack, and a linear displacement sensor; after the electrode foil flows out of the drying unit, it sequentially enters the foil winding buffer rack and the automatic foil winder; the linear displacement sensor is installed on the foil winding buffer rack, and the detection end of the linear displacement sensor faces the electrode foil for detecting the moving speed of the electrode foil; the automatic foil winding unit adjusts the terminal winding speed of the electrode foil to make the moving speed of the electrode foil on the foil winding buffer rack equal to the target moving speed.

[0023] In one embodiment, it further includes a central control unit, and the central control unit includes an operation screen and a PLC main controller; the PLC main controller is electrically connected to the operation screen, the foil unwinding unit, the switching power supply, the multi-stage forming unit, the intermediate processing unit, the first baking and repairing unit, the second baking and repairing unit, the drying unit, and the foil winding unit respectively, for receiving the feedback data in the units and following up and adjusting to control multiple process parameters of the electrode foil in multiple units, so that the electrode foil passes through the multi-stage forming unit, the intermediate processing unit, the first baking and repairing unit, the second baking and repairing unit, and the drying unit stably with constant tension.

[0024] A precision control system for a production line for improving the consistency of the oxide film of an electrode foil proposed by the present invention, aiming at the problems of low control precision of multi-stage parameters in the oxidation process, inability to achieve dynamic intelligent regulation, and lack of abnormal state recognition ability in the prior art, designs a precision control production line with multi-stage and multi-unit linkage control and closed-loop feedback, and has the following beneficial effects:

[0025] (1) Improve the consistency and density of the oxide film formation

[0026] The present invention realizes stable power-on cooperation for the electrode foil through the conductive rollers in the foil unwinding unit, and the alternating configuration of the positive and negative electrode slots in the multi-stage forming unit, ensuring that the electrode foil is continuously and stably anodized during the conveying process. By cooperating multiple positive and negative electrode slots, the current introduced into the electrode foil is dispersed, avoiding large current concentration in one slot and preventing the electrode foil from being overheated and ablated. At the same time, it can promote the layered growth of the oxide film by segmented oxidation, greatly improving the thickness uniformity, microstructural density, and overall integrity of the oxide film.

[0027] (2) Realize the structural stratification and defect repair of the oxide film

[0028] By setting the first baking and repairing unit and the second baking and repairing unit, hierarchical high-temperature treatment and multi-round anodic oxidation repair are carried out on the oxide film of the electrode foil, which not only promotes the optimization and transformation of the crystal structure of the film layer, but also effectively repairs the film layer defects, improves the density and integrity of the oxide film, and thus improves the performance stability and reliability of the capacitor in extreme environments such as high temperature and high humidity.

[0029] (3) Improve the water resistance and chemical stability of the oxide film

[0030] In the phosphoric acid treatment step of the middle treatment unit, the primary oxide film can be further converted into a composite oxide film with strong water permeability resistance, forming more γ'-Al2O3 in the oxide film, which can effectively block the migration of oxygen-containing substances into the film, prevent the formation of porous aluminum hydroxide from the source, and significantly enhance the water resistance and service life of the finished electrode foil.

[0031] (4) Ensure the stability of the full-process process conditions and product consistency

[0032] By setting a foil winding unit with constant tension control and a multi-stage synchronous conveying mechanism, on the premise of ensuring a constant conveying tension of the electrode foil, the coordination consistency between each treatment unit is improved, effectively reducing the film layer unevenness or crack phenomenon caused by tension fluctuations, and further enhancing the uniformity and controllability of the oxide film.

[0033] (5) Facilitate the realization of intelligent and large-scale stable production

[0034] The present invention systematically integrates multi-stage treatment modules, and reserves interfaces for subsequent supporting parameter monitoring, intelligent feedback control, and abnormal alarm systems, providing a good platform foundation for building an anodic oxidation automated production line with high consistency, low failure rate, and scalable deployment.

[0035] In summary, the present invention can effectively improve the quality of the oxide film of the electrode foil for solid aluminum electrolytic capacitors, especially outstanding in terms of film formation consistency, denseness, water resistance, and reliability, and has significant industrial application value and promotion prospects. Brief Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 It is a schematic structural diagram of the precision control system of the production line of the present invention;

[0038] Figure 2 It is a control schematic diagram of the central control unit of the present invention.

[0039] Among them, the reference numerals are as follows:

[0040] 1. Foil unwinding unit; 11. Foil unwinder; 12. Foil unwinding buffer rack;

[0041] 2. Conductive roller;

[0042] 3. Multi - stage into units; 31. The first negative electrode tank; 32. The second negative electrode tank; 33. The third negative electrode tank; 34. The positive electrode tank; 35. The fourth negative electrode tank;

[0043] 4. Intermediate processing unit; 41. Phosphoric acid tank; 42. The first water washing tank; 43. Elevator; 431. Roller shaft;

[0044] 51. The first roasting and repairing unit; 511. The first roasting furnace; 512. The first repairing tank; 513. The second water washing tank;

[0045] 52. The second roasting and repairing unit; 521. The second roasting furnace; 522. The second repairing tank; 523. The third water washing tank;

[0046] 6. Drying unit;

[0047] 7. Foil receiving unit; 71. Automatic foil receiver; 72. Foil receiving buffer rack; 73. Linear displacement sensor;

[0048] 81. Switching power supply; 82. Central control unit; 821. Operation screen; 822. PLC main controller;

[0049] 9. Electrode foil. Specific implementation mode

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0051] A precision control system for a production line for improving the consistency of the oxide film of electrode foils is provided in the specific implementation mode. A foil feeding unit, a multi - stage forming unit, an intermediate processing unit, the first and second roasting and repairing units, a drying unit, and a foil receiving unit are sequentially arranged along the conveying direction of the electrode foil; the foil feeding unit is provided with conductive rollers to energize the electrode foil; the multi - stage forming unit alternately arranges positive and negative electrode tanks to segmentally corrode and oxidize the electrode foil, promoting the layered stacking of the oxide film, and improving the thickness and density; the intermediate processing unit enhances the water - resistance of the oxide film through phosphoric acid treatment; the roasting and repairing unit realizes multi - stage heat treatment and multi - stage oxidation repair to improve the integrity of the film layer structure; the drying unit realizes surface drying; the foil receiving unit controls the conveying of the electrode foil through constant tension to improve the stability of the processing process; through the whole - process process parameter control and segmented optimization of the film layer, the system significantly improves the uniformity, density, and reliability of the oxide film of the electrode foil, and is applicable to the batch manufacturing of high - consistency electrode materials for solid aluminum electrolytic capacitors; effectively solving the technical problems existing in the existing oxidation control of electrode foils, such as low precision in controlling multi - stage parameters in the oxidation process, inability to realize intelligent regulation under dynamic working conditions, and insufficient ability to identify abnormal states in the oxidation process, which easily leads to fluctuations in the performance of the oxide film and a reduction in product consistency.

[0052] The first embodiment of the precision control system for the production line is as follows Figure 1 As shown, it includes a foil feeding unit 1 arranged in sequence along the conveying direction of the electrode foil 9. A squirrel-cage conductive roller 2 is installed in the foil feeding unit 1 and is used to energize the electrode foil 9 during foil feeding; and a multi-stage formation unit 3. The multi-stage formation unit 3 includes a negative electrode tank, a positive electrode tank 34, and a negative electrode tank arranged in sequence along the conveying direction of the electrode foil 9, and performs multi-stage anodic oxidation treatment on the electrode foil 9 to generate corrosion and the growth of an oxide film in a layered manner on the surface of the electrode foil 9, so that the oxide films are stacked in layers, improving the thickness, uniformity, and density of the formed oxide film; and a middle treatment unit 4. The middle treatment unit 4 includes a phosphoric acid tank 41 and a first water washing tank 42. The phosphoric acid tank 41 is used to convert the oxide film formed on the electrode foil 9 into a water-resistant composite oxide film, preventing oxygen-containing substances from migrating into the interior of the oxide film and avoiding the formation of porous aluminum hydroxide, thereby improving the water resistance of the oxide film and enhancing the reliability of the application of the oxide film of the finished electrode foil 9 in solid aluminum electrolytic capacitors; and a first baking and repairing unit 51. The first baking and repairing unit 51 first bakes and performs anodic oxidation treatment on the electrode foil 9 to repair the oxide film; and a second baking and repairing unit 52. The second baking and repairing unit 52 performs secondary baking on the electrode foil 9 and then performs secondary anodic oxidation treatment; The first baking and repairing unit 51 and the second baking and repairing unit 52 perform hierarchical high-temperature treatment on the oxide film of the electrode foil 9 to achieve hierarchical transformation of the crystals of the oxide film on the surface of the electrode foil 9, and then repair the defective parts of the oxide film by hierarchical anodic oxidation treatment, improving the integrity of the oxide film of the electrode foil 9 and increasing the density of the oxide film structure of the electrode foil 9; and a drying unit 6. The drying unit 6 performs drying treatment on the surface of the electrode foil 9 by high temperature; and a foil receiving unit 7. The foil receiving unit 7 is used to automatically adjust the winding speed of the electrode foil 9, keeping the electrode foil 9 conveyed at a constant tension in the multi-stage formation unit 3, the middle treatment unit 4, the first baking and repairing unit 51, the second baking and repairing unit 52, and the drying unit 6, making the formation treatment of the electrode foil 9 more stable, and the formation of the oxide film more uniform and dense.

[0053] A precision control system for a production line designed by the present invention to improve the consistency of the oxide film of the electrode foil. Aiming at the problems of low control accuracy of multi-stage parameters in the oxidation process, inability to achieve dynamic intelligent control, and lack of abnormal state recognition ability in the prior art, a precision control production line with multi-stage multi-unit linkage control and closed-loop feedback is designed, having the following advantages:

[0054] Improve the consistency and density of the oxide film formation: In the present invention, the stable power supply cooperation for the electrode foil 9 is achieved through the conductive roller 2 in the foil feeding unit 1, and the positive and negative electrode tanks in the multi-stage formation unit 3 are alternately arranged to ensure that the electrode foil 9 is continuously and stably anodized during the conveying process. By cooperating multiple positive and negative electrode tanks, the current introduced into the electrode foil 9 is dispersed, avoiding the concentration of large current in one tank and preventing the electrode foil 9 from being overheated and ablated. At the same time, it can promote the layered growth of the oxide film by segmented oxidation, greatly improving the thickness uniformity, microstructural density and overall integrity of the oxide film.

[0055] Realize the structural layering and defect repair of the oxide film: By setting the first calcination repair unit 51 and the second calcination repair unit 52, hierarchical high-temperature treatment and multiple rounds of anodic oxidation repair are carried out on the oxide film of the electrode foil 9, which not only promotes the optimization transformation of the film layer crystal structure, but also effectively repairs the film layer defects, improves the density and integrity of the oxide film, and thus enhances the performance stability and reliability of the capacitor in extreme environments such as high temperature and high humidity.

[0056] Improve the water resistance and chemical stability of the oxide film: In the phosphoric acid treatment link of the intermediate treatment unit 4, the primary oxide film can be further transformed into a composite oxide film with strong water permeability resistance, forming more γ'-Al2O3 in the oxide film, which can effectively block the migration of oxygen-containing substances into the film and prevent the formation of porous aluminum hydroxide from the source, significantly enhancing the water resistance and service life of the finished electrode foil 9.

[0057] Ensure the stability of the whole process process conditions and product consistency: By setting the foil winding unit 7 with constant tension control and the multi-stage synchronous conveying mechanism, on the premise of ensuring the constant conveying tension of the electrode foil 9, the coordination consistency between each treatment unit is improved, effectively reducing the film layer unevenness or crack phenomenon caused by tension fluctuation, and further enhancing the uniformity and controllability of the oxide film.

[0058] Facilitate the realization of intelligent and large-scale stable production: The present invention systematically integrates multi-stage processing modules and reserves interfaces for subsequent supporting parameter monitoring, intelligent feedback control and abnormal alarm systems, providing a good platform foundation for building an anodic oxidation automatic production line with high consistency, low failure rate and scalable deployment.

[0059] In summary, the present invention can effectively improve the quality of the oxide film of the electrode foil 9 for solid aluminum electrolytic capacitors, especially outstanding in terms of film formation consistency, density, water resistance and reliability, and has significant industrial application value and promotion prospects.

[0060] As an optional implementation manner:

[0061] Regarding the specific structures of the above-mentioned foil feeding unit 1 and foil winding unit 7, and the realization of constant tension conveying control of the electrode foil 9 by the foil feeding unit 1 and the foil winding unit 7, this embodiment is as follows Figure 1 As shown, regarding the foil feeding unit 1: The foil feeding unit 1 includes a foil feeder 11 and a foil feeding buffer rack 12; the foil feeder 11 releases the electrode foil 9, and the electrode foil 9 sequentially passes through the foil feeding buffer rack 12, the multi-stage forming unit 3, the intermediate treatment unit 4, the first baking and repairing unit 51, the second baking and repairing unit 52, and the drying unit 6, and finally enters the foil winding unit 7. The foil feeding buffer rack 12 cooperates with the foil winding unit 7 to apply a constant tension to the conveyed electrode foil 9 to avoid stretching or compression of the electrode foil 9 during the conveying process.

[0062] Regarding the foil winding unit 7: The foil winding unit 7 includes an automatic foil winder 71, a foil winding buffer rack 72, and a linear displacement sensor 73; after the electrode foil 9 flows out of the drying unit 6, it sequentially enters the foil winding buffer rack 72 and the automatic foil winder 71; the linear displacement sensor 73 is installed on the foil winding buffer rack 72, and the detection end of the linear displacement sensor 73 faces the electrode foil 9 and is used to detect the moving speed of the electrode foil 9; the automatic foil winding unit 7 adjusts the terminal winding speed of the electrode foil 9 to make the moving speed of the electrode foil 9 on the foil winding buffer rack 72 equal to the target moving speed.

[0063] In specific applications, the actual moving speed of the electrode foil 9 is collected between the foil feeding buffer rack 12 and the foil winding buffer rack 72 through the linear displacement sensor 73, and the signal is transmitted to the PLC main controller 822; the PLC main controller 822 adjusts the driving parameters of the automatic foil winder 71 according to the feedback information to make the winding speed consistent with the actual running speed of the foil material, realizing the whole-process tension balance control, which can effectively avoid the stretching or relaxation of the foil material caused by tension fluctuations, prevent film layer cracking, peeling or wrinkling, and improve the film layer uniformity during the forming process; it solves the problems of uneven oxide film formation and mechanical damage due to the lack of constant tension control in the existing production line.

[0064] Regarding the interlocking control of the above-mentioned multiple units, this embodiment is as follows Figure 2 As shown, it further includes a central control unit 82, and the central control unit 82 includes an operation screen 821 and a PLC main controller 822; the PLC main controller 822 is electrically connected to the operation screen 821, the foil feeding unit 1, the switching power supply 81, the multi-stage forming unit 3, the intermediate treatment unit 4, the first baking and repairing unit 51, the second baking and repairing unit 52, the drying unit 6, and the foil winding unit 7 respectively;

[0065] Among them, the PLC master controller 822 is electrically connected to the operation screen 821, the foil feeder 11, the foil feeding buffer rack 12, the switching power supply 81, the first negative electrode tank 31, the second negative electrode tank 32, the third negative electrode tank 33, the positive electrode tank 34, the fourth negative electrode tank 35, the phosphoric acid tank 41, the elevator 43, the first baking furnace 511, the first repair tank 512, the second baking furnace 521, the second repair tank 522, the drying unit 6, the automatic foil rewinder 71, the foil rewinding buffer rack 72 and the linear displacement sensor 73 respectively, and is used to receive the data fed back by each device in the unit, and follow-up adjust and control multiple process parameters of the electrode foil 9 in multiple units, so that the electrode foil 9 passes through the multi-stage forming unit 3, the intermediate processing unit 4, the first baking and repair unit 51, the second baking and repair unit 52 and the drying unit 6 stably with a constant tension.

[0066] Specifically, the foil is fed at a constant tension in the foil feeding unit 1, the stable forming is carried out in the multi-stage forming unit 3 and the intermediate processing unit 4, the stable baking and repair are carried out in the first baking and repair unit 51 and the second baking and repair unit 52, the stable drying is carried out in the drying unit 6, and the foil is rewound at a constant tension in the foil rewinding unit 7.

[0067] In addition, a tension sensor and an active floating roller shaft 431 device are integrated in the foil feeding unit 1, the multi-stage forming unit 3, the intermediate processing unit 4, the first and second baking and repair units 52 and the drying unit 6. The tension sensor is electrically connected to the PLC master controller 822. The tension sensor senses the tension fluctuation of the electrode foil 9 in each unit and feeds back the tension fluctuation data to the PLC master controller 822. The PLC master controller 822 then performs floating adjustment on the active floating roller shaft 431 device according to the fed-back data, so as to perform a higher-frequency closed-loop correction on the tension fluctuation, ensure that the tension control is more stable during the transportation of the electrode foil 9, and thus improve the accuracy of tension control.

[0068] Regarding the specific structure and setting method of the current shunting realized by the cooperation of the conductive roller 2 and the multi-stage forming unit 3 and the grading formation of the electrode foil 9, this embodiment is as Figure 1 shown. Among them, regarding the specific setting of the conductive roller 2, a switching power supply 81 is also provided on the multi-stage forming unit 3; the conductive roller 2 is arranged between the foil feeding buffer rack 12 and the multi-stage forming unit 3, and the conductive roller 2 is connected to the positive pole of the switching power supply 81 and receives a current of 700 A.

[0069] Among them, regarding the specific setting of the multi-stage forming unit 3, there are four negative electrode tanks, including a first negative electrode tank 31, a second negative electrode tank 32, a third negative electrode tank 33, and a fourth negative electrode tank 35; the first negative electrode tank 31, the second negative electrode tank 32, the third negative electrode tank 33, the positive electrode tank 34, and the fourth negative electrode tank 35 are arranged in sequence along the conveying direction of the electrode foil 9; after the electrode foil 9 enters the multi-stage forming unit 3, it passes through the first negative electrode tank 31, the second negative electrode tank 32, the third negative electrode tank 33, the positive electrode tank 34, and the fourth negative electrode tank 35 in sequence; the first negative electrode tank 31, the second negative electrode tank 32, the third negative electrode tank 33, and the fourth negative electrode tank 35 are respectively connected to the negative electrode of the switching power supply 81 and receive a current of 250 A; the positive electrode tank 34 is connected to the positive electrode of the switching power supply 81 and receives a current of 300 A.

[0070] In specific applications, the conductive roller 2 is located between the foil feeding buffer rack 12 and the first negative electrode tank 31, and provides stable power supply to the electrode foil 9 by receiving a current of 700 A; each of the four downstream negative electrode tanks receives a current of 250 A, and the positive electrode tank 34 receives a current of 300 A, realizing the differential distribution of forming currents in different regions; by segmentally controlling different current densities, the oxide film is formed in layers, strengthening the growth characteristics and film formation uniformity of each layer structure; overcoming the problems of uneven film thickness distribution, prominent edge effect, and easy overheating and ablation of the electrode foil 9 caused by the traditional single-current power supply method.

[0071] In addition, the connection of the switching power supply 81 to the conductive roller 2, each positive and negative electrode tank, and the number of positive and negative electrode tanks can further optimize the current ratio configuration of each tank according to the thickness and width of the imported electrode foil 9, improving the orderliness of film layer stacking and the efficiency of internal stress release.

[0072] Regarding the uniformity control of the reaction of the electrode foil 9 in the phosphoric acid tank 41 of the intermediate treatment unit 4, in this embodiment, Figure 1 as shown, after the electrode foil 9 flows out of the fourth negative electrode tank 35, it enters the phosphoric acid tank 41 and the first water washing tank 42 in sequence; a lifter 43 is installed in the phosphoric acid tank 41, and the telescopic end of the lifter 43 is connected to the roller shaft 431 that guides the conveying of the electrode foil 9 in the phosphoric acid tank 41, controlling the contact height between the oxide film on the surface of the electrode foil 9 entering the phosphoric acid tank 41 and the liquid in the phosphoric acid tank 41, so that the oxide film on the surface of the electrode foil 9 rises and falls with the liquid level in the phosphoric acid tank 41.

[0073] During application, the elevator 43 controls the height of the roller 431 in the phosphoric acid tank 41 to keep the surface of the electrode foil 9 and the liquid level of the phosphoric acid solution change synchronously, thereby adjusting the immersion depth to ensure that the phosphoric acid reacts fully with the oxide film, and thus the reaction consistency of each section of the oxide film; it is beneficial to improve the uniformity of the reaction between the oxide film and the phosphoric acid, form a more stable composite film layer, and improve its water resistance and dielectric strength; thus solving the problems of insufficient local reaction caused by the bending degree of the electrode foil 9 or the liquid level fluctuation, and large differences in the performance of the local film layer or the performance of each adjacent film layer.

[0074] In addition, a liquid level sensor and an automatic liquid replenishing unit are arranged in the phosphoric acid tank 41. The liquid level sensor, the automatic liquid replenishing unit and the PLC main controller 822 are connected and data exchange is maintained. Through the closed-loop control of the PLC main controller 822, the liquid level sensor and the automatic liquid replenishing unit, the phosphoric acid concentration and the liquid level are kept constant, and the process state of the phosphoric acid tank 41 is dynamically corrected.

[0075] The oxide film of the electrode foil 9 is subjected to step-by-step roasting and patching treatment, so that the alumina structure of the film layer is gradually transformed from amorphous (non-crystalline) Al2O3, hydrated alumina film and porous Al2O3 film into γ'-Al2O3 in layers, and finally from γ'-Al2O3 to γ-Al2O3 type, obtaining an oxide film layer with better compactness, higher reliability and higher specific capacitance. Moreover, the hierarchical roasting (high-temperature transformation) and anodic oxidation patching treatment can further improve the film-forming uniformity and integrity of the oxide film. This embodiment is as Figure 1 shown, in which the first roasting and patching unit 51 includes a first roasting furnace 511, a first patching tank 512 and a second water washing tank 513; after the electrode foil 9 flows out of the first water washing tank 42, it successively enters the first roasting furnace 511, the first patching tank 512 and the second water washing tank 513.

[0076] Among them, the second roasting and patching unit 52 includes a second roasting furnace 521, a second patching tank 522 and a third water washing tank 523; after the electrode foil 9 flows out of the second water washing tank 513, it successively enters the second roasting furnace 521, the second patching tank 522 and the third water washing tank 523.

[0077] During application, after the electrode foil 9 is heat-treated at a high temperature in the first roasting furnace 511, the original amorphous Al2O3, hydrates, and porous structure in the film layer undergo a structural transformation to form γ′-Al2O3. Subsequently, the electrode foil 9 that has undergone the first high-temperature treatment is anodized in the first repair tank 512 to repair the micro-defects formed due to thermal stress or film layer degradation and increase the amount of γ′-Al2O3. Then, it enters the second roasting furnace 521 for continuous high-temperature transformation to form a transition from γ′-Al2O3 to γ-Al2O3. After that, it undergoes a second anodization repair of the oxide film structure in the second repair tank 522, and finally, the densification and repair of the film layer are completed. By subjecting the oxide film to graded high-temperature transformation and anodization repair, an oxide film with high densification, distinct layers, and stable structure can be obtained, significantly improving its dielectric properties and reliability, and solving the problems that traditional single-step oxidation or single roasting cannot form a stable film structure or further improve the structural stability of the oxide film, and it is difficult to repair the defects.

[0078] During high-temperature roasting, the PLC master controller 822 can actively adjust the roasting temperature curve and time for each stage according to the film layer thickness, electrode foil 9 thickness, and width required for different applications, so as to realize the preparation of customized oxide films for different film types or application scenarios.

[0079] The second embodiment of the precision control system of the production line. The difference between this embodiment and the first embodiment is that the conductive roller 2 is composed of a central copper column and an aluminum conductive comb; the aluminum conductive comb is arranged in a circumferential array around the outer circumference of the central copper column, and the surface of the aluminum conductive comb in contact with the electrode foil 9 is plated with a silver layer to reduce the resistance between the conductive roller 2 and the electrode foil 9 and reduce the heat generation of the conductive roller 2 and the electrode foil 9. A water-cooling cavity is arranged between the aluminum conductive comb and the central copper column to take away the heat generated by the electric shock rod through water cooling, reduce the heat transferred from the conductive roller 2 to the electrode foil 9, and reduce the temperature rise at the contact between the electrode foil 9 and the conductive roller 2.

[0080] During application, the direct contact surface between the aluminum conductive comb and the electrode foil 9 has high conductivity and low contact resistance due to the silver layer, which can effectively reduce the heat accumulation caused by energization per unit area. At the same time, a water-cooling cavity is arranged inside the conductive roller 2, and the heat is taken away by the circulating coolant to prevent local overheating. It can ensure long-term stable conduction between the electrode foil 9 and the conductive roller 2, and at the same time avoid local softening, shrinkage or film layer ablation of the foil caused by high temperature, thus solving the problem that the existing conductive roller 2 generates excessive heat due to long-term energization, resulting in foil shrinkage and thermal damage to the film layer.

[0081] In addition, by integrating a temperature sensor and a cooling flow control unit on the conductive roller 2, connecting the temperature sensor, the cooling flow control unit with the PLC main controller 822 and maintaining data exchange, through the closed-loop control of the PLC main controller 822 with the temperature sensor and the cooling flow control unit, an intelligent thermal management unit is constructed to achieve refined control of the heat of the conductive roller 2, further reduce the thermal runaway phenomenon of foil shrinkage or film layer ablation, improve the state stability of the electrode foil 9 during production, and thus maintain the stability of the film layer quality; temperature sensors are also integrated in each positive and negative electrode tank to monitor the temperature of the passing electrode foil 9 in real time and transmit the temperature data back to the PLC main controller 822.

[0082] To achieve the goal of forming an anodic oxidation film with high consistency, high integrity and high density during the whole process of anodic oxidation of the electrode foil, the present invention provides a precise linkage control method dominated by a central control unit; this method takes the PLC main controller as the core and comprehensively controls the key equipment units in the whole process such as foil feeding, chemical conversion, intermediate treatment, baking and repair, and foil winding. The control method includes the following steps:

[0083] Step S1, initial tension balance control

[0084] S1.1. The central control unit real-time collects the running speed and tension change of the electrode foil in the foil winding buffer rack through a linear displacement sensor, and feeds back the tension state signal to the PLC main controller;

[0085] S1.2. The PLC main controller adjusts the driving motor frequency of the automatic foil winding machine according to the feedback signal to control its winding speed to match the running speed of the foil feeding section;

[0086] S1.3. Synchronously adjust the release speed of the foil feeding machine and the floating roller pressure of the foil feeding buffer rack to achieve balanced head and tail tension, so that the electrode foil passes through each unit in a constant tension state.

[0087] Step S2, the foil feeding machine controls the conductive roller for conduction and the switching power supply for power supply

[0088] S2.1. The PLC main controller starts the electric release device of the foil feeding machine and synchronously starts the power supply to the conductive roller;

[0089] S2.2. Control the switching power supply to output a constant current of 700A to the conductive roller to ensure sufficient pre-charging on the surface of the electrode foil before entering the chemical conversion tank and avoid uneven film layer formation caused by delayed anode start-up.

[0090] Step S3, dynamic current regulation of the multi-stage chemical conversion unit

[0091] S3.1. The PLC main controller controls each negative electrode tank (the first to the fourth) to receive a current of 250A respectively according to the set program, and the positive electrode tank receives a current of 300A;

[0092] S3.2. When abnormal fluctuations occur in the tension, temperature, or conveying speed of the electrode foil, the current adjustment scheme can be automatically switched to finely adjust the inter-tank current ratio, avoiding film layer ablation or being too thin caused by excessive local current density.

[0093] S3.3. The control system is optionally equipped with a real-time current monitoring module to achieve adaptive adjustment of segmented shunt formation in a closed-loop manner.

[0094] Step S4. Dynamic matching control of the phosphoric acid tank liquid level by the processing unit

[0095] S4.1. The height adjustment of the elevator is controlled by the PLC master controller, and it automatically rises and falls according to the state of the oxide film at the outlet of the formation tank or the set chemical conversion curve to achieve adaptive adjustment.

[0096] S4.2. The elevator controls the contact depth between the phosphoric acid liquid level and the surface of the electrode foil to be constant, or automatically finely adjusts the position of the roller shaft according to the liquid level fluctuation and tension state to improve the uniformity of the phosphoric acid conversion reaction.

[0097] S4.3. The PLC master controller links the liquid level sensor with the automatic liquid filling unit to achieve automatic liquid level balance.

[0098] Step S5. Synchronous control of heat treatment and repair by the roasting and repair unit

[0099] S5.1. The PLC master controller sets the temperature curves and residence times of the first roasting furnace and the second roasting furnace to control the phase transformation of the oxide film on the surface of the electrode foil from amorphous Al2O3 to γ′-Al2O3 and then to γ-Al2O3 step by step.

[0100] S5.2. Control the first repair tank and the second repair tank to perform anodic oxidation repair on the roasted film layer at specific voltage and current densities respectively to further seal micropores and cracks.

[0101] S5.3. The temperature, transmission speed, residence time during roasting, and the electrical control parameters of oxidation repair can be linked with the PLC master controller to be automatically adjusted according to the feedback data and cooperate with each other to form a precise film formation control closed-loop.

[0102] Step S6. Full-process state synchronous monitoring and alarm feedback

[0103] S6.1. The PLC master controller obtains various process state parameters such as conductive current, tension sensor, temperature sensor, liquid level sensor, linear displacement sensor, etc. in a periodic sampling manner.

[0104] S6.2. When working conditions such as abnormal tension, abnormal film thickness, winding error, current mismatch, etc. occur, the PLC master controller automatically adjusts the operating parameters of the corresponding equipment and issues an alarm prompt.

[0105] S6.3. The operation screen displays the process operation curve and alarm log in real time for the operator to intervene or manually reconstruct the parameter settings.

[0106] Through the above process control steps, the following can be achieved: centralized collaborative control of multi-device, multi-parameter, and multi-stage process conditions is realized, improving the operation stability of the equipment on the entire production line; through the coordination of constant tension and segmented forming, the oxide film remains uniform during long-distance operation and the film layer damage during long-distance transportation after forming is reduced; finally, before the electrode foil is wound up, through the coordinated control mechanism of roasting and repair, the integrity and density of the film layer are effectively improved; it can adapt to the oxidation process requirements of different electrode foil materials and different target specific capacitance indicators, and has the basis for high scalability and intelligent control; moreover, the system has the ability of abnormal self-diagnosis and emergency handling, which can greatly reduce the film formation defect rate and improve the overall yield.

[0107] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described.

Claims

1. A precision control system for a production line to improve the consistency of the oxide film on the electrode foil, characterized in that it includes a foil feeding unit arranged in sequence along the conveying direction of the electrode foil. A squirrel-cage conductive roller is installed in the foil feeding unit, which is used to energize the electrode foil during foil feeding; and multiple-stage formation units. The multiple-stage formation units include a negative electrode tank, a positive electrode tank, and a negative electrode tank arranged in sequence along the conveying direction of the electrode foil, which perform multiple-stage anodic oxidation treatment on the electrode foil to generate corrosion and the growth of the oxide film in a layered manner on the surface of the electrode foil; and an intermediate treatment unit. The intermediate treatment unit includes a phosphoric acid tank and a first water washing tank. The phosphoric acid tank is used to convert the oxide film formed on the electrode foil into a water-resistant composite oxide film, preventing oxygen-containing substances from migrating into the interior of the oxide film and avoiding the formation of porous aluminum hydroxide; and a first baking and repair unit, which first bakes the electrode foil and then performs anodic oxidation treatment to repair the oxide film; and a second baking and repair unit, which performs secondary baking on the electrode foil and then performs secondary anodic oxidation treatment; the first baking and repair unit and the second baking and repair unit perform hierarchical high-temperature treatment on the oxide film of the electrode foil to achieve hierarchical transformation of the crystals of the oxide film on the surface of the electrode foil, and then repair the defective parts of the oxide film by hierarchical anodic oxidation treatment; and a drying unit, which performs drying treatment on the surface of the electrode foil through high temperature; and a foil winding unit, which is used to automatically adjust the winding speed of the electrode foil, and keep the electrode foil being conveyed at a constant tension in the multiple-stage formation units, the intermediate treatment unit, the first baking and repair unit, the second baking and repair unit, and the drying unit, so that the formation treatment of the electrode foil is more stable, and the formation of the oxide film is more uniform and dense.

2. The precision control system for the production line according to claim 1, characterized in that the foil feeding unit includes a foil feeder and a foil feeding buffer rack; the foil feeder releases the electrode foil. The electrode foil sequentially passes through the foil feeding buffer rack, the multiple-stage formation units, the intermediate treatment unit, the first baking and repair unit, the second baking and repair unit, and the drying unit, and finally enters the foil winding unit. The foil feeding buffer rack cooperates with the foil winding unit to apply a constant tension to the conveyed electrode foil to prevent the electrode foil from being stretched or compressed during the conveying process.

3. The precision control system for the production line according to claim 2, characterized in that a switching power supply is also provided between the conductive roller and the multiple-stage formation units; the conductive roller is arranged between the foil feeding buffer rack and the multiple-stage formation units. The conductive roller is connected to the positive pole of the switching power supply and receives a current of 700 A.

4. The precision control system for the production line according to claim 3, characterized in that the conductive roller is composed of a central copper column and an aluminum conductive comb; the aluminum conductive combs are arranged in a circular array around the outer circumference of the central copper column. The surface of the aluminum conductive comb in contact with the electrode foil is plated with a silver layer, which is used to increase the resistance between the conductive roller and the electrode foil and reduce the heat generation of the conductive roller and the electrode foil; A water-cooling cavity is provided between the aluminum conductive comb and the central copper column, which is used to remove the heat generated by the electric shock baton through water cooling, reduce the heat transferred from the conductive roller to the electrode foil, and reduce the temperature rise at the contact between the electrode foil and the conductive roller.

5. The precision control system for a production line according to claim 3, wherein There are four negative electrode grooves, including a first negative electrode groove, a second negative electrode groove, a third negative electrode groove, and a fourth negative electrode groove; Among them, the first negative electrode groove, the second negative electrode groove, the third negative electrode groove, the positive electrode groove, and the fourth negative electrode groove are arranged in sequence along the conveying direction of the electrode foil; After the electrode foil enters the multi-stage forming unit, it sequentially passes through the first negative electrode groove, the second negative electrode groove, the third negative electrode groove, the positive electrode groove, and the fourth negative electrode groove; The first negative electrode groove, the second negative electrode groove, the third negative electrode groove, and the fourth negative electrode groove are respectively connected to the negative electrode of the switching power supply and receive a current of 250 A; The positive electrode groove is connected to the positive electrode of the switching power supply and receives a current of 300 A.

6. The precision control system for a production line according to claim 5, wherein After the electrode foil flows out of the fourth negative electrode groove, it sequentially enters the phosphoric acid tank and the first water washing tank; An elevator is installed in the phosphoric acid tank. The telescopic end of the elevator is connected to the roller shaft that guides the conveying of the electrode foil in the phosphoric acid tank, controlling the contact height between the oxide film on the surface of the electrode foil entering the phosphoric acid tank and the liquid in the phosphoric acid tank, so that the oxide film on the surface of the electrode foil rises and falls with the liquid level in the phosphoric acid tank.

7. The precision control system for a production line according to claim 6, wherein The first baking and repairing unit includes a first baking furnace, a first repairing tank, and a second water washing tank; After the electrode foil flows out of the first water washing tank, it sequentially enters the first baking furnace, the first repairing tank, and the second water washing tank.

8. The precision control system for a production line according to claim 7, wherein The second baking and repairing unit includes a second baking furnace, a second repairing tank, and a third water washing tank; After the electrode foil flows out of the second water washing tank, it sequentially enters the second baking furnace, the second repairing tank, and the third water washing tank.

9. The precision control system for a production line according to any one of claims 7 or 8, wherein The foil receiving unit includes an automatic foil receiving machine, a foil receiving buffer rack, and a linear displacement sensor; After the electrode foil flows out of the drying unit, it sequentially enters the foil receiving buffer rack and the automatic foil receiving machine; The linear displacement sensor is installed on the foil receiving buffer rack, and the detection end of the linear displacement sensor faces the electrode foil, which is used to detect the moving speed of the electrode foil; The automatic foil receiving unit adjusts the terminal winding speed of the electrode foil to make the moving speed of the electrode foil on the foil receiving buffer rack equal to the target moving speed.

10. The precision control system for a production line according to claim 9, wherein It further includes a central control unit, and the central control unit includes an operation screen and a PLC main controller; the PLC main controller is electrically connected to the operation screen, the foil feeding unit, the switching power supply, the multi-stage formation unit, the intermediate processing unit, the first baking and repairing unit, the second baking and repairing unit, the drying unit and the foil receiving unit respectively, and is used for receiving the feedback data in the units, and following and adjusting to control multiple process parameters of the electrode foil in multiple units, so that the electrode foil passes through the multi-stage formation unit, the intermediate processing unit, the first baking and repairing unit, the second baking and repairing unit and the drying unit stably under constant tension.

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