Tubular structure micro-arc oxidation device, equipment and method

Abstract

The application discloses a tubular structure micro-arc oxidation device, equipment and method, and belongs to the technical field of surface treatment devices, and can solve the problems that the inner cavity of a tubular structure cannot be micro-arc oxidized or the oxidation film layer is thin. The micro-arc oxidation device comprises a micro-arc oxidation tank, a first cathode mechanism, a second cathode mechanism, an anode mechanism and a fixing mechanism. The first cathode mechanism is arranged on the side wall of the micro-arc oxidation tank. The second cathode mechanism comprises a cathode rod. The fixing mechanism is used for inserting the cathode rod into the inner cavity of the tubular structure which needs to be micro-arc oxidized, and spacing the outer peripheral wall of the cathode rod and the inner peripheral wall of the inner cavity by a preset distance, and simultaneously used for connecting the tubular structure and the anode mechanism. The cathode rod and the first cathode mechanism are connected with the negative pole of a power supply. The anode mechanism is connected with the positive pole of the power supply. The application can micro-arc oxidize the inner cavity of the tubular structure and ensure the thickness of the oxidation film layer.

Description

Technical Field

[0001] This application relates to the field of surface treatment apparatus technology, and in particular to a micro-arc oxidation apparatus, equipment and method for tubular structural components. Background Technology

[0002] Against the backdrop of global energy shortages and the dual-carbon strategy, advocating green, environmentally friendly, and low-carbon lifestyles, accelerating the pace of carbon emission reduction, guiding green technology innovation, and enhancing the global competitiveness of industries and the economy are new development directions. Simultaneous economic development and green transformation is a new trend in the development of metallic materials, with various fields increasingly using lightweight metals such as aluminum, magnesium, titanium, and their alloys as structural or functional materials. However, lightweight metals are prone to corrosion under extremely harsh natural environmental conditions, thus giving rise to surface treatment technologies for lightweight metals to prevent corrosion.

[0003] Surface treatment technologies for light metals typically employ fluorocarbon spraying, powder coating, and anodizing. However, conventional surface treatment methods often result in protective layers on light metal workpieces that have poor adhesion to the substrate, uneven uniformity, inadequate protection in specific areas, poor weather resistance, environmental unfriendliness, and susceptibility to peeling. Micro-arc oxidation, as a novel process for surface protection of light metals, can grow a film layer in situ on the substrate surface. This film layer offers controllable thickness, strong weather resistance, a simple process, and minimal environmental pollution, making it a new, green, and environmentally friendly material surface treatment technology with broad application prospects in aerospace, machinery, electronics, and decorative industries.

[0004] However, when micro-arc oxidation processes are used to process tubular structural parts, the inherent structure of these parts can easily cause internal electric field shielding or weak electric field strength on the inner wall, resulting in the inability to micro-arc oxidize the inner cavity or a thin oxide film layer. Summary of the Invention

[0005] This application provides a micro-arc oxidation device, equipment, and method for tubular structural components, which can solve the problem that the inner cavity of tubular structural components cannot be micro-arc oxidized or the oxide film layer is thin.

[0006] In a first aspect, embodiments of the present invention provide a micro-arc oxidation device for tubular structural components, including a micro-arc oxidation tank, a first cathode mechanism, a second cathode mechanism, an anode mechanism, and a fixing mechanism; the first cathode mechanism is disposed on the side wall of the micro-arc oxidation tank; the second cathode mechanism includes a cathode rod; the fixing mechanism is used to insert the cathode rod into the inner cavity of the tubular structural component that requires micro-arc oxidation, and to space the outer peripheral wall of the cathode rod from the inner peripheral wall of the inner cavity by a predetermined distance, and is also used to connect the tubular structural component to the anode mechanism; both the cathode rod and the first cathode mechanism are connected to the negative terminal of a power supply; the anode mechanism is connected to the positive terminal of the power supply.

[0007] In conjunction with the first aspect, in one possible implementation, the micro-arc oxidation device for tubular structural components further includes a cooling circulation mechanism; after the solution in the micro-arc oxidation tank is heated, it is input into the input end of the cooling circulation mechanism, and the output end of the cooling circulation mechanism then inputs the cooled solution into the micro-arc oxidation tank.

[0008] In conjunction with the first aspect, in one possible implementation, the cathode rod is tubular; a plurality of first through holes are evenly distributed on the sidewall of the cathode rod; and one end of the cathode rod is connected to the output end of the cooling circulation mechanism.

[0009] In conjunction with the first aspect, in one possible implementation, the second cathode mechanism further includes a plug; the plug is disposed at the other end of the cathode rod.

[0010] In conjunction with the first aspect, in one possible implementation, when the tubular structural component undergoes micro-arc oxidation, the central axis of the tubular structural component forms a preset angle with the bottom surface of the micro-arc oxidation tank.

[0011] In conjunction with the first aspect, in one possible implementation, the tubular structure micro-arc oxidation device further includes a cooling tube; the cooling tube is disposed at the bottom of the micro-arc oxidation tank, and has second through holes evenly distributed on the tube wall inside the micro-arc oxidation tank, with one end extending out of the micro-arc oxidation tank and connected to the output end of the cooling circulation mechanism.

[0012] In conjunction with the first aspect, in one possible implementation, the first cathode mechanism includes an insulating plate, a first conductive busbar, and a cathode plate group; a group of the cathode plate groups is respectively disposed on two opposing inner sidewalls of the micro-arc oxidation tank; the cathode plate group includes multiple cathode plates, which are evenly spaced and arrayed along the length direction of the inner sidewall; adjacent cathode plates are connected in series through the first conductive busbar; the insulating plate is disposed at the bottom end of each group of cathode plates away from the inner sidewall of the micro-arc oxidation tank.

[0013] In conjunction with the first aspect, in one possible implementation, the tubular structure micro-arc oxidation device further includes a gas distribution pipe and a gas generating mechanism; the gas distribution pipe is disposed at the bottom of the micro-arc oxidation tank, and has through holes evenly distributed on the pipe wall inside the micro-arc oxidation tank, with one end extending out of the micro-arc oxidation tank and connected to the gas generating mechanism.

[0014] In conjunction with the first aspect, in one possible implementation, the central axis of the via is at an angle of 40° to 50° to the central axis of the gas distribution pipe at its location.

[0015] In conjunction with the first aspect, in one possible implementation, the fixing mechanism includes at least one set of fixing structures; each set of fixing structures includes a first fixing ring, a second fixing ring, and a support rod; the support rod includes at least two rods, and the two ends of each support rod are respectively fixed to the first fixing ring and the second fixing ring; the first fixing ring is used to secure the cathode rod, and the second fixing ring is used to secure the tubular structural component and connect to the positive terminal of the power supply.

[0016] In conjunction with the first aspect, in one possible implementation, the fixing structure further includes fixing adjustment members; at least two sets of fixing adjustment members are provided on the ring walls of the first fixing ring and the second fixing ring; the fixing adjustment members provided on the first fixing ring are used to secure the cathode rod, and the fixing adjustment members on the second fixing ring are used to secure the tubular structural member.

[0017] In conjunction with the first aspect, in one possible implementation, the micro-arc oxidation device for tubular structural components further includes a lifting mechanism; the lifting mechanism is connected to the tubular structural component.

[0018] Secondly, embodiments of the present invention provide a micro-arc oxidation device for tubular structural components, comprising a first cleaning device, the aforementioned micro-arc oxidation device for tubular structural components, a second cleaning device, a drying device, and a post-treatment device arranged sequentially.

[0019] Thirdly, embodiments of the present invention provide a micro-arc oxidation method for tubular structural components, comprising:

[0020] Perform a cleaning on tubular structural components to be subjected to micro-arc oxidation; The tubular structural components are micro-arc oxidation after cleaning is performed using the micro-arc oxidation device described above. The tubular structural components after micro-arc oxidation are then subjected to secondary cleaning. The tubular structural components are dried after the second cleaning; The dried tubular structural components undergo post-processing.

[0021] Fourthly, the embodiments of the present invention provide the application of the micro-arc oxidation method for tubular structural parts described above in the preparation of ceramic oxide film layers on the surface of tubular structural parts.

[0022] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: This invention provides a micro-arc oxidation device for tubular structural components. The device includes a micro-arc oxidation tank, a first cathode mechanism, a second cathode mechanism, an anode mechanism, and a fixing mechanism. The first cathode mechanism is disposed on the side wall of the micro-arc oxidation tank. The second cathode mechanism includes a cathode rod. The fixing mechanism is used to insert the cathode rod into the inner cavity of the tubular structural component requiring micro-arc oxidation, and to maintain a predetermined distance between the outer peripheral wall of the cathode rod and the inner peripheral wall of the inner cavity. It also connects the tubular structural component to the anode mechanism. Both the cathode rod and the first cathode mechanism are connected to the negative terminal of a power supply. The anode mechanism is connected to the positive terminal of the power supply.

[0023] The micro-arc oxidation device for tubular structural components provided in this invention uses a fixing mechanism to insert a cathode rod into the inner cavity of the tubular structural component requiring micro-arc oxidation, and to maintain a predetermined distance between the outer peripheral wall of the cathode rod of the second cathode mechanism and the inner peripheral wall of the inner cavity. Simultaneously, the fixing mechanism connects the tubular structural component to the anode mechanism. The first cathode mechanism, the second cathode mechanism, and the anode mechanism are each connected to a power source. When micro-arc oxidation of the inner wall of the tubular structural component is required, the power source is energized to the anode mechanism and the cathode rod. When simultaneous micro-arc oxidation of the inner and outer peripheral walls of the tubular structural component is required, the power source is energized to the anode mechanism, the cathode rod, and the first cathode mechanism, thus shortening the micro-arc oxidation time of the tubular structural component. The micro-arc oxidation device of this application embodiment can micro-arc oxidize the inner cavity of tubular structural parts while ensuring the thickness of the oxide film layer. At the same time, it shortens the micro-arc oxidation processing cycle, improves the efficiency of oxide film preparation, and produces oxide film layers with good uniformity. The oxide film layer thickness of the inner sidewall and outer peripheral wall of the tubular structural parts is relatively consistent, and the overall surface performance is good. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of the micro-arc oxidation device for tubular structural components provided in the embodiments of this application. Figure 1 ; Figure 2 A schematic diagram of a portion of the structure of the micro-arc oxidation device for tubular structural components provided in an embodiment of this application; Figure 3 This is a schematic diagram of the fixing structure provided in the embodiments of this application; Figure 4 A schematic diagram of the micro-arc oxidation device for tubular structural components provided in the embodiments of this application. Figure 2; Figure 5 This is a schematic diagram of the structure of the micro-arc oxidation device for tubular structural components provided in the embodiments of this application; Figure 6 A flowchart illustrating the micro-arc oxidation method for tubular structural components provided in this application embodiment.

[0026] Icons: 1-Micro-arc oxidation tank; 2-First cathode mechanism; 21-Cathode plate; 22-First conductive bus; 3-Second cathode mechanism; 31-Cathode rod; 311-First through hole; 32-Plug; 4-Anode mechanism; 41-Connector; 42-Second conductive bus; 5-Fixing mechanism; 51-Fixing structure; 511-First fixing ring; 512-Second fixing ring; 513-Support rod; 514-Fixing adjustment component; 5141-Bolt; 5142-Nut; 6-Power supply; 7-Cooling circulation mechanism; 71-Cooler; 72-Diverter valve; 8-Gas distribution pipe; 81-Through hole; 9-Cooling aid pipe; 91-Second through hole; 10-Lifting mechanism; 101-Gantry frame; 102-Gear motor; 103-Take-up belt; 20-Tube-shaped structural component; 30-Upper hanging area; 40-First cleaning device; 401-First cleaning unit; 402-Second cleaning unit; 50-Micro-arc oxidation equipment for tubular structural components; 60-Second cleaning device; 70-Drying device; 80-Post-processing device; 90-Lower hanging area. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0029] Please refer to Figure 1 As shown, this embodiment of the invention provides a micro-arc oxidation device for tubular structural components, including a micro-arc oxidation tank 1, a first cathode mechanism 2, a second cathode mechanism 3, an anode mechanism 4, and a fixing mechanism 5. The shape of the micro-arc oxidation tank 1 is determined according to the shape of the tubular structural component 20 that actually needs micro-arc oxidation, such as... Figure 1 As shown, the micro-arc oxidation tank 1 provided in this embodiment of the application has a hexahedral shape.

[0030] The first cathode mechanism 2 is disposed on the side wall of the micro-arc oxidation tank 1. The second cathode mechanism 3 includes a cathode rod 31, the outer diameter of which is smaller than the inner diameter of the tubular structure 20. The fixing mechanism 5 is used to insert the cathode rod 31 into the inner cavity of the tubular structure 20 that requires micro-arc oxidation, and to maintain a predetermined distance between the outer peripheral wall of the cathode rod 31 and the inner peripheral wall of the inner cavity. It also connects the tubular structure 20 to the anode mechanism 4. The predetermined distance between the outer peripheral wall of the cathode rod 31 and the inner peripheral wall of the inner cavity is determined according to the thickness of the oxide film layer to be prepared in the inner cavity; when a thicker oxide film layer is required, a cathode rod 31 with a larger outer diameter is selected, and the predetermined distance is smaller; when a thinner oxide film layer is required, a cathode rod 31 with a smaller outer diameter is selected, and the predetermined distance is larger.

[0031] Both the cathode rod 31 and the first cathode mechanism 2 are connected to the negative terminal of the power supply 6. The anode mechanism 4 is connected to the positive terminal of the power supply 6. In practice, during the micro-arc oxidation process, the tubular structural component 20 is prone to uneven oxide film thickness and edge ablation due to the inconsistent electric field strength between its inner and outer peripheral walls. The cathode rod 31, located inside the tubular structural component 20, ensures that the tubular structural component 20 maintains consistent electric field strength between its inner and outer surfaces during micro-arc oxidation.

[0032] The micro-arc oxidation device for tubular structural components provided in this embodiment of the invention uses a fixing mechanism 5 to insert a cathode rod 31 into the inner cavity of the tubular structural component 20 where micro-arc oxidation is required. The outer peripheral wall of the cathode rod 31 of the second cathode mechanism 3 is spaced a predetermined distance from the inner peripheral wall of the inner cavity. Simultaneously, the fixing mechanism 5 connects the tubular structural component 20 to the anode mechanism 4. The first cathode mechanism 2, the second cathode mechanism 3, and the anode mechanism 4 are each connected to a power supply 6. When micro-arc oxidation of the inner wall of the tubular structural component 20 is required, the power supply 6 is simply energized to the anode mechanism 4 and the cathode rod 31. When simultaneous micro-arc oxidation of the inner and outer peripheral walls of the tubular structural component 20 is required, the power supply 6 is energized to the anode mechanism 4, the cathode rod 31, and the first cathode mechanism 2, thus shortening the micro-arc oxidation time of the tubular structural component. The micro-arc oxidation device of this application embodiment can micro-arc oxidize the inner cavity of the tubular structural component 20 while ensuring the thickness of the oxide film layer. At the same time, it shortens the micro-arc oxidation processing cycle, improves the efficiency of oxide film preparation, and produces an oxide film layer with good uniformity. The oxide film layer thickness of the inner sidewall and outer peripheral wall of the tubular structural component 20 is relatively consistent, and the overall surface performance is good.

[0033] Continue to refer to Figure 1 As shown, the micro-arc oxidation device also includes a cooling circulation mechanism 7. After being heated in the micro-arc oxidation tank 1, the solution is input to the input end of the cooling circulation mechanism 7, and the output end of the cooling circulation mechanism 7 then inputs the cooled solution back into the micro-arc oxidation tank 1. This solution is mainly an electrolyte. The cooling circulation mechanism includes a cooler 71.

[0034] like Figure 1As shown, a bottom plate is provided at the lower part of the inner wall of the micro-arc oxidation tank 1, with the surface of the bottom plate perpendicular to the inner wall. A side plate is then provided at the location of the bottom plate, with its surface perpendicular to the bottom plate, forming a ring groove on the inner wall. An opening is provided at the location of the ring groove on the side wall of the micro-arc oxidation tank 1, and this opening is connected to the input end of the cooling circulation mechanism 7. When the cooling circulation mechanism 7 draws solution from this opening, the solution in the micro-arc oxidation tank 1, after heating, flows in from the upper end of the ring groove, into the ring groove, and then into the cooling circulation mechanism 7 through the opening. An input port is provided at the bottom end of the micro-arc oxidation tank 1, and the output end of the cooling circulation mechanism 7 is connected to this input port to input the solution cooled by the cooling circulation mechanism 7 into the micro-arc oxidation tank 1.

[0035] In practice, the instantaneous high temperature and high pressure effects generated during micro-arc oxidation cause a rapid rise in the solution temperature inside the tubular structural component 20. This high-temperature liquid environment is unfavorable for oxide film growth and easily leads to ablation on the surface of the tubular structural component 20. Consequently, the prepared oxide film cannot completely cover the surface of the tubular structural component 20, and the uniformity of the oxide film on the inner and outer walls of the tubular structural component 20 is poor, limiting the application of micro-arc oxidation technology. The cooling circulation mechanism 7 rapidly exchanges the heated solution during the micro-arc oxidation of the tubular structural component 20, reducing the overall solution temperature and maintaining a constant temperature within the micro-arc oxidation tank 1. This prevents ablation during the micro-arc oxidation of the tubular structural component, improves the uniformity of the oxide film on the inner and outer walls of the tubular structural component 20, and results in an excellent oxide film.

[0036] Reference Figure 1 and Figure 2 As shown, the cathode rod 31 is tubular, thus forming a fluid flow channel within its inner cavity. Multiple first through holes 311 are evenly distributed on the sidewalls of the cathode rod 31. Figure 2 As shown, the cathode rod 31 is arranged in a circumferential ring with at least two sets of first through holes. Each set of first through holes includes at least two first through holes 311. The at least two first through holes 311 are arranged in a straight line along the axial direction of the cathode rod 31. The first first through hole 311 in each set of first through holes is offset along the axial direction. The diameter of each first through hole 311 is φ1.5mm, and the spacing between adjacent first through holes 311 in each set of first through holes is 100mm.

[0037] One end of the cathode rod 31 is connected to the output end of the cooling circulation mechanism 7. Specifically, a quick-connect fitting is provided at one end of the cathode rod 31, which connects to the output end of the cooling circulation mechanism 7 to facilitate connection between the cathode rod 31 and the output end of the cooling circulation mechanism 7. In practice, a diversion valve 72 is provided at the output end of the cooling circulation mechanism 7. The diversion valve 72 divides the cooled solution output from the output end of the cooling circulation mechanism 7 into two streams: one stream enters the inlet of the micro-arc oxidation tank 1, and the other stream enters the inner cavity of the cathode rod 31. Furthermore, a throttling control valve is provided at the port of the diversion valve 72 to control the fluid flow rate of the solution cooled by the cooling circulation mechanism 7.

[0038] In practice, the solution inside the tubular structure 20 cannot circulate, and the solution temperature is too high, making the inner cavity prone to ablation. The cathode rod 31, however, is tubular with multiple first through holes 311 evenly distributed on its sidewall. One end is connected to the output end of the cooling circulation mechanism, allowing the solution cooled by the cooling circulation mechanism 7 to be input into the inner cavity of the tubular structure 20. This ensures that the cooled solution directly enters the inner cavity of the tubular structure 20, reducing the temperature inside. Simultaneously, the solution inside the cavity flows out through the first through holes 311, enabling circulation and agitation cooling of the solution within the cavity, thus preventing ablation.

[0039] Furthermore, the axial length of the first through hole 311 on the cathode rod 31 is less than the axial length of the inner cavity of the tubular structure 20 that requires micro-arc oxidation, thereby improving the stirring ability and solution circulation ability of the liquid in the inner cavity of the tubular structure 20, timely removing the gas generated during the micro-arc oxidation process, and improving the exchange rate of the solution in the inner cavity.

[0040] Continue to refer to Figure 1 and Figure 2 As shown, the second cathode mechanism 3 also includes a plug 32. The plug 32 is disposed at the other end of the cathode rod 31. Specifically, the plug 32 is an insulated conical plug. The placement of the plug 32 can increase the pressure inside the cathode rod 31, thereby allowing the liquid flowing out from the first through hole 311 to better agitate the solution inside the tubular structure 20.

[0041] Furthermore, such as Figure 1 As shown, when the tubular structure 20 is subjected to micro-arc oxidation, the central axis of the tubular structure 20 is at a preset angle to the bottom surface of the micro-arc oxidation tank 1, that is, the tubular structure 20 is inclined relative to the bottom surface of the micro-arc oxidation tank 1.

[0042] Currently, the micro-arc oxidation process treats workpieces using a complete immersion method, where the entire workpiece is immersed in a micro-arc oxidation tank 1 filled with electrolyte. The suspension method and orientation of the workpiece in the micro-arc oxidation tank 1 are adjusted according to the orientation of the cathode plate 21 on the inner wall of the tank 1. This immersion method is highly efficient for processing small, simple geometrically simple, and mass-produced standard parts, but it encounters numerous problems when performing one-time surface treatment on complex-shaped or cavitary structural parts. For example, when immersing a tubular structural part 20 in the solution, the gas generated by the reaction is not easily expelled from the inner cavity of the solution. Setting the central axis of the tubular structural part 20 at a predetermined angle to the bottom surface of the micro-arc oxidation tank 1 helps to promptly expel the gas generated by the reaction inside the tubular structural part 20 during immersion in the solution and during the micro-arc oxidation process. Preferably, this predetermined angle is greater than 30°.

[0043] like Figure 4 As shown, the micro-arc oxidation device provided in this embodiment further includes a cooling tube 9. The cooling tube 9 is disposed at the bottom of the micro-arc oxidation tank 1, and has second through holes 91 evenly distributed on its wall within the inner cavity of the micro-arc oxidation tank 1. One end extends out of the micro-arc oxidation tank 1 as an input port and connects to the output end of the cooling circulation mechanism 7. (Refer to...) Figure 4 As shown, the cooling tube 9 is arranged in a rectangular shape within the micro-arc oxidation tank 1.

[0044] In practice, the first cathode mechanism 2 includes an insulating plate, a first conductive busbar 22, and cathode plate assemblies. A cathode plate assembly is respectively arranged on two opposing inner sidewalls of the micro-arc oxidation tank 1. Each cathode plate assembly includes multiple cathode plates 21, evenly spaced along the length of the inner sidewall. The cathode plates 21 can be made of stainless steel. Adjacent cathode plates 21 are connected in series via the first conductive busbar 22, i.e., as shown... Figure 4 As shown, the cathode plates 21 of the same cathode plate group are connected in series through the first conductive bar 22, and the first cathode plate 21 of one cathode plate group is connected in series with the last cathode plate 21 of another cathode plate group through the first conductive bar 22.

[0045] The first conductive busbar 22 is generally made of copper. To prevent corrosion of the first conductive busbar 22, it is always positioned above the solution surface. Generally, adjacent cathode plates 21 in the same cathode plate group are spaced 200mm apart. This spacing between cathode plates 21 ensures the uniformity of the overlapping electric field within the micro-arc oxidation tank 1, allowing the tubular structural component 20 to be stably and fully oxidized during the micro-arc oxidation process. An insulating plate is installed at the bottom of each cathode plate group, away from the inner wall of the micro-arc oxidation tank 1. A certain gap is generally provided between the insulating plate and the cathode plate group to facilitate heat dissipation during operation. Furthermore, the insulating plate has uniformly distributed third through holes with a diameter of φ30mm, further facilitating heat dissipation during operation.

[0046] like Figure 4 As shown, the micro-arc oxidation device also includes a gas distribution pipe 8 and a gas generating mechanism. The gas distribution pipe 8 is located at the bottom of the micro-arc oxidation tank 1, and has through holes 81 evenly distributed on its wall within the inner cavity of the tank 1. One end extends out of the tank 1 and connects to the gas generating mechanism. Optionally, the gas generating device is an air compressor. Figure 4 As shown, at least one set of through holes is arranged in a straight line along the axial direction of the gas distribution pipe 8. Each set of through holes includes at least two through holes 81. The at least two through holes 81 are arranged in a ring array around the central axis of the gas distribution pipe 8 on the side wall of the gas distribution pipe 8.

[0047] Furthermore, the central axis of the through hole 81 and the central axis of the gas distribution pipe 8 form an angle of 40° to 50°. Preferably, the central axis of the through hole 81 and the central axis of the gas distribution pipe 8 form an angle of 45°. Thus, during the micro-arc oxidation process, the gas input into the gas distribution pipe 8 by the gas generating mechanism is discharged into the micro-arc oxidation tank 1 through the through hole 81. This allows the surface of the solution in the micro-arc oxidation tank 1 to be in a wave-removing state, and the interior of the solution to be in a stirring state. This ensures rapid stirring of the solution in the micro-arc oxidation tank 1 and timely removal of the generated gas, maintaining a relatively constant temperature of the solution and eliminating color differences in the transition area.

[0048] In practice, when the tubular structural component 20 is large, it will be micro-arc oxidation performed on different areas of the tubular structural component 20 in sequence. However, there will be differences in the thickness of the oxide film layer produced in the area of ​​the previous micro-arc oxidation and the area of ​​the current micro-arc oxidation. This difference is the color difference in the transition area.

[0049] like Figure 3 As shown, the fixing mechanism 5 includes at least one set of fixing structures 51. The number of fixing structures 51 is set according to actual needs, such as... Figure 1 A schematic diagram of the structure of the fixing mechanism 5, which includes two sets of fixing structures 51, is shown.

[0050] Each set of fixing structures 51 includes a first fixing ring 511, a second fixing ring 512, and a support rod 513. The support rod 513 includes at least two rods, and both ends of each support rod 513 are fixed to the first fixing ring 511 and the second fixing ring 512, respectively. Figure 3 A schematic diagram of a structure with three support rods 513 is shown. The first fixing ring 511 is used to secure the cathode rod 31, and the second fixing ring 512 is used to secure the tubular structural member 20 and is connected to the positive terminal of the power supply 6. The fixing structure 51 provided in this embodiment can securely secure the cathode rod 31 and the tubular structural member 20.

[0051] Continue to refer to Figure 3 As shown, the fixing structure 51 also includes fixing adjustment members 514. At least two sets of fixing adjustment members 514 are provided on the ring walls of the first fixing ring 511 and the second fixing ring 512. Figure 3 A schematic diagram shows a structure in which three sets of fixing adjustment members 514 are provided on the ring walls of the first fixing ring 511 and the second fixing ring 512. The fixing adjustment member 514 on the first fixing ring 511 is used to secure the cathode rod 31, and the fixing adjustment member 514 on the second fixing ring 512 is used to secure the tubular structural member 20. Further, the fixing adjustment member 514 on the second fixing ring 512 connected to the anode mechanism 4 is made of conductive material, while the remaining fixing adjustment members 514 are made of insulating material.

[0052] The setting of the fixing adjustment component 514 can adjust the diameter of the cathode rod 31 according to the inner diameter of the tubular structural component 20 and the required field strength, so as to ensure that tubular structural components 20 and cathode rods 31 of different sizes can be firmly fixed.

[0053] like Figure 3 As shown, the fixing and adjusting component 514 may include a bolt 5141 and two nuts 5142. After one nut 5142 is fitted onto the bolt 5141, the front end passes through the side wall of the tubular structure 20, and then another nut 5142 is fitted onto it. When both nuts 5142 are turned simultaneously, the length of the front end of the bolt 5141 extending into the inner cavity of the first fixing ring 511 or the second fixing ring 512 can be adjusted, thereby securing tubular structures 20 and cathode rods of different outer diameters.

[0054] Optionally, the end of the bolt 5141 on the second fixing ring 512 is a tapered flat head, which can ensure good conductivity of the workpiece and will not affect the formation of the oxide film layer on the outer wall of the tubular structural component 20 at the contact point with the bolt 5141.

[0055] like Figure 1As shown, the micro-arc oxidation device provided in this embodiment of the invention also includes a lifting mechanism 10. The lifting mechanism 10 is connected to the tubular structure 20, thereby enabling the lifting mechanism 10 to move the tubular structure 20 up and down within the cavity of the micro-arc oxidation tank 1, allowing the tubular structure 20 to be immersed in the solution in the micro-arc oxidation tank 1 or removed from the cavity of the micro-arc oxidation tank 1. Figure 1 As shown, the lifting mechanism 10 includes a gantry frame 101, a reduction motor 102, and a winding belt 103. The anode mechanism 4 includes a second conductive busbar 42 (generally a copper busbar) and connecting pieces 41 in the same number as the fixing mechanism 5. The gantry frame 101 is located outside the micro-arc oxidation tank 1, and the reduction motor 102 is mounted on the gantry frame 101, with its output end connected to the winding belt 103. The lower end of the winding belt 103 is connected to the second conductive busbar 42. The connecting piece 41 has an L-shaped side, with its upper end connected to the second conductive busbar 42 and its other end connected to the fixing adjustment piece 514 on the second fixing ring 512 of the fixing mechanism 5. This connecting piece 41 is the conductive contact connecting the fixing structure 51 and the second conductive busbar 42, and is made of conductive material. The reduction motor 102 drives the winding belt 103 to move up and down, thereby driving the anode mechanism 4, the second cathode mechanism 3, and the tubular structural component 20 to move up and down.

[0056] The micro-arc oxidation device provided in this application embodiment can be used for micro-arc oxidation surface treatment of the inner and outer walls of large tubular structural components 20. This eliminates the need for multiple steps and frequent disassembly of the tubular structural component 20, the second cathode mechanism 3, or the anode mechanism 4, thus improving production efficiency and shortening the processing cycle. Furthermore, the quality of the oxide film can be controlled by adjusting the diameter of the cathode rod 31 of the second cathode mechanism 3 and the static parameters of the micro-arc oxidation tank 1. This results in an oxide film with high hardness, uniform thickness, uniform surface color, no ablation, no cracks, no oxidation transition zone, and good corrosion and wear resistance. In addition, micro-arc oxidation surface treatment using this device simplifies the process, allows for controllable production speed, and reduces production costs.

[0057] like Figure 5 As shown in the figure, an embodiment of the present invention provides a micro-arc oxidation device for tubular structural components, comprising a first cleaning device 40, a micro-arc oxidation device for tubular structural components 50, a second cleaning device 60, a drying device 70, and a post-processing device 80 arranged sequentially. The first cleaning device 40 includes a first cleaning unit 401 and a second cleaning unit 402.

[0058] The specific working process of the micro-arc oxidation equipment for tubular structural components provided in this embodiment of the invention is as follows: The tubular structural component 20 is suspended on the flybar of a gantry crane. Positioned and controlled by the gantry crane, the tubular structural component 20 is hung from the upper hanging area 30. It is then sequentially cleaned by the first cleaning unit 401 and the second cleaning unit 402 to remove dirt and impurities from its surface. Afterward, it enters the micro-arc oxidation tank 1 of the micro-arc oxidation device 50 for micro-arc oxidation treatment. After micro-arc oxidation, it enters the second cleaning device 60 to remove residual liquid from its surface. Then, it enters the drying device 70 for drying, followed by the post-treatment device 80 for surface sealing and drying treatment. Finally, it is unhung from the lower hanging area 90.

[0059] This invention provides a micro-arc oxidation method for tubular structural components, such as... Figure 6 As shown, it includes: Step 601: Clean the tubular structural component 20 to be micro-arc oxidized.

[0060] Step 602: Use the micro-arc oxidation device 50 described above to perform micro-arc oxidation on the cleaned tubular structural component 20.

[0061] Step 603: Perform a second cleaning on the tubular structural component 20 after micro-arc oxidation.

[0062] Step 604: Dry the tubular structural component 20 after the second cleaning.

[0063] Step 605: Perform post-processing on the dried tubular structural component 20.

[0064] The above-mentioned micro-arc oxidation method for tubular structural parts is applied in the preparation of ceramic oxide film on the surface of tubular structural part 20.

[0065] Example 1 Prepare raw materials: Select industrial or building aluminum tubing with dimensions of φ120mm×2000mm and wall thickness d=3mm; cathode rod 31 is φ30mm×2300mm with wall thickness d=1.5mm.

[0066] Set the parameters for power supply 6 as follows: voltage 600V, frequency 500Hz, duty cycle 25%, time 12min; air compressor output pressure 1-1.2MPa; cooling temperature setting 25-35℃.

[0067] The tubular structural component 20, equipped with the second cathode mechanism 3 and the anode mechanism 4, is suspended on a gantry crane. Through the crane positioning, the tubular structural component 20 is sequentially passed through the first cleaning device 40, the tubular structural component micro-arc oxidation device 50, the second cleaning device 60, the drying device 70, and the post-treatment device 80, until it reaches the hanging area 90, to obtain a ceramic oxide film layer on the surface of the tubular workpiece for industrial or construction use. By adjusting the liquid diversion and throttling control valves and the gas pressure in the micro-arc oxidation tank 1, the gas or liquid stirring efficiency of the inner and outer cavities of the tubular structural component 20 is ensured.

[0068] The tubular structural component 20 prepared in this embodiment has a uniform color of micro-arc oxide film layer on both the inner and outer walls, with no transition layer. The average thickness of the outer wall film layer is 15.2 μm, the thickness of the inner wall film layer is 14.8 μm, and the surface roughness is 1.23 μm.

[0069] Example 2 Prepare raw materials: Select industrial or building aluminum tubing with dimensions of φ120mm×2000mm and wall thickness d=3mm; cathode rod 31 is φ50mm×2300mm with wall thickness d=1.5mm.

[0070] Set the power supply parameters as follows: voltage 600V, frequency 500Hz, duty cycle 25%, time 12min; air compressor output pressure 1-1.2MPa; cooling temperature setting 25-35℃.

[0071] The tubular structural component 20, equipped with the second cathode mechanism 3 and the anode mechanism 4, is suspended on a gantry crane. Through the crane positioning, the tubular structural component 20 is sequentially passed through the first cleaning device 40, the tubular structural component micro-arc oxidation device 50, the second cleaning device 60, the drying device 70, and the post-treatment device 80, until it reaches the hanging area 90, to obtain a ceramic oxide film layer on the surface of the tubular workpiece for industrial or construction use. By adjusting the liquid diversion and throttling control valves and the gas pressure in the micro-arc oxidation tank 1, the gas or liquid stirring efficiency of the inner and outer cavities of the tubular structural component 20 is ensured.

[0072] The tubular structural component 20 prepared in this embodiment has a uniform color of micro-arc oxide film layer on both the inner and outer walls, with no transition layer. The average thickness of the outer wall film layer is 15.4 μm, the thickness of the inner wall film layer is 16.4 μm, and the surface roughness is 1.32 μm.

[0073] Example 3 Prepare raw materials: Select industrial or building aluminum tubing with dimensions of φ180mm×2000mm and wall thickness d=3mm; cathode rod 31 is φ50mm×2300mm with wall thickness d=1.5mm.

[0074] Set the power supply parameters as follows: voltage 600V, frequency 500Hz, duty cycle 25%, time 12min; air compressor output pressure 1-1.2MPa; cooling temperature setting 25-35℃.

[0075] The tubular structural component 20, equipped with the second cathode mechanism 3 and the anode mechanism 4, is suspended on a gantry crane. Through the crane positioning, the tubular structural component 20 is sequentially passed through the first cleaning device 40, the tubular structural component micro-arc oxidation device 50, the second cleaning device 60, the drying device 70, and the post-treatment device 80, until it reaches the hanging area 90, to obtain a ceramic oxide film layer on the surface of the tubular workpiece for industrial or construction use. By adjusting the liquid diversion and throttling control valves and the gas pressure in the micro-arc oxidation tank 1, the gas or liquid stirring efficiency of the inner and outer cavities of the tubular structural component 20 is ensured.

[0076] The micro-arc oxidation film prepared in this embodiment has a uniform color, no transition layer, and an average thickness of 14.5 μm for the outer wall film, 13.7 μm for the inner wall film, and a surface roughness of 1.21 μm.

[0077] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0078] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A micro-arc oxidation device for tubular structural components, characterized in that, It includes a micro-arc oxidation tank, a first cathode mechanism, a second cathode mechanism, an anode mechanism, and a fixing mechanism; The first cathode mechanism is disposed on the side wall of the micro-arc oxidation tank; The second cathode mechanism includes a cathode rod; The fixing mechanism is used to insert the cathode rod into the inner cavity of the tubular structure that requires micro-arc oxidation, and to keep the outer peripheral wall of the cathode rod and the inner peripheral wall of the inner cavity at a predetermined distance. It is also used to connect the tubular structure to the anode mechanism. Both the cathode rod and the first cathode mechanism are connected to the negative terminal of the power supply; The anode mechanism is connected to the positive terminal of the power supply; The cathode rod is tubular; The cathode rod has multiple first through holes evenly distributed on its sidewall; It also includes a cooling circulation mechanism; One end of the cathode rod is connected to the output end of the cooling circulation mechanism; The second cathode mechanism also includes a plug; The plug is located at the other end of the cathode rod; After the solution is heated in the micro-arc oxidation tank, it is input into the input end of the cooling circulation mechanism, and the output end of the cooling circulation mechanism then inputs the cooled solution into the micro-arc oxidation tank. Wherein, the axial length of the first through hole on the cathode rod is less than the axial length of the inner cavity of the tubular structure that requires micro-arc oxidation; the plug is an insulating conical plug.

2. The micro-arc oxidation device for tubular structural components according to claim 1, characterized in that, When the tubular structure is subjected to micro-arc oxidation, the central axis of the tubular structure is at a preset angle to the bottom surface of the micro-arc oxidation tank.

3. The micro-arc oxidation device for tubular structural components according to claim 1, characterized in that, It also includes cooling pipes; The cooling tube is located at the bottom of the micro-arc oxidation tank, and has second through holes evenly distributed on the tube wall inside the micro-arc oxidation tank. One end of the tube extends out of the micro-arc oxidation tank and is connected to the output end of the cooling circulation mechanism.

4. The micro-arc oxidation device for tubular structural components according to claim 1, characterized in that, The first cathode mechanism includes an insulating plate, a first conductive busbar, and a cathode plate assembly; A set of cathode plates is respectively arranged on the two opposite inner sidewalls of the micro-arc oxidation tank; The cathode plate assembly includes multiple cathode plates, which are evenly distributed in an array along the length of the inner sidewall. The two adjacent cathode plates are connected in series through the first conductive busbar; The insulating plate is installed at the bottom end of each cathode plate group, away from the inner wall of the micro-arc oxidation tank.

5. The micro-arc oxidation device for tubular structural components according to claim 1, characterized in that, It also includes gas distribution pipelines and gas generation mechanisms; The gas distribution pipe is located at the bottom of the micro-arc oxidation tank, and has through holes evenly distributed on the pipe wall inside the micro-arc oxidation tank. One end extends out of the micro-arc oxidation tank and is connected to the gas generating mechanism.

6. The micro-arc oxidation device for tubular structural components according to claim 5, characterized in that, The central axis of the through hole and the central axis of the gas distribution pipe at its location form an angle of 40° to 50°.

7. The micro-arc oxidation device for tubular structural components according to claim 1, characterized in that, The fixing mechanism includes at least one set of fixing structures; Each set of fixing structures includes a first fixing ring, a second fixing ring, and a support rod; The support rod includes at least two rods, and the two ends of each support rod are respectively fixed to the first fixing ring and the second fixing ring; The first retaining ring is used to secure the cathode rod, and the second retaining ring is used to secure the tubular structural component and connect it to the positive terminal of the power supply.

8. The micro-arc oxidation device for tubular structural components according to claim 7, characterized in that, The fixing structure also includes a fixing adjustment component; At least two sets of fixing adjustment members are provided on the ring walls of the first fixing ring and the second fixing ring; The fixing adjustment member disposed on the first fixing ring is used to secure the cathode rod, and the fixing adjustment member on the second fixing ring is used to secure the tubular structural member.

9. The micro-arc oxidation device for tubular structural components according to claim 1, characterized in that, It also includes a lifting mechanism; The lifting mechanism is connected to the tubular structural component.

10. A micro-arc oxidation device for tubular structural components, characterized in that, It includes a first cleaning device, a micro-arc oxidation device for tubular structural parts as described in any one of claims 1 to 9, a second cleaning device, a drying device, and a post-treatment device arranged in sequence.

11. A micro-arc oxidation method for tubular structural components, characterized in that, include: Perform a cleaning on tubular structural components to be subjected to micro-arc oxidation; The tubular structural component is subjected to micro-arc oxidation after cleaning using the micro-arc oxidation device according to any one of claims 1 to 9; The tubular structural components after micro-arc oxidation are then subjected to secondary cleaning. The tubular structural components are dried after the second cleaning; The dried tubular structural components undergo post-processing.

12. The application of the micro-arc oxidation method for tubular structural components as described in claim 11 in the preparation of ceramic oxide film layers on the surface of tubular structural components.

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