Anode tool for micro-arc oxidation

Abstract

An anode fixture for micro-arc oxidation includes a rotating shaft and a workpiece fixing assembly. The rotating shaft comprises a first straight rod and a second straight rod. The rear end of the first straight rod is rotatably connected to the front end of the second straight rod via a pin. The front end of the first straight rod is connected to the positive terminal of the oxidation power source. The rear section of the second straight rod is an externally threaded section. The workpiece fixing assembly is mounted on the externally threaded section and includes a positioning nut, a ring spring support plate, and a fastening nut. The outer diameter of the ring spring support plate is smaller than the inner diameter of the workpiece fixing hole, while the outer diameters of the positioning nut and the fastening nut are larger than the inner diameter of the workpiece fixing hole. The positioning nut is sleeved on the upper part of the externally threaded section, and the ring spring support plate is sleeved on the externally threaded section and abuts against the positioning nut. The workpiece is sleeved outside the ring spring support plate and secured by tightening the fastening nut. This invention has a reasonable structure, is easy to operate, effectively improves the uniformity of the oxide film on the workpiece surface, protects the anode contact area of ​​the workpiece from ablation, and improves production efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of metal surface treatment technology and relates to an anode tooling for micro-arc oxidation. Background Technology

[0002] Electrochemical oxidation of metals refers to the anodic process in which electron transfer occurs at the metal / solution interface under the influence of an electric field, causing the metal to lose electrons and form an oxide film. This process can generate a dense and firmly adhered oxide ceramic layer on the surface of metals such as aluminum, titanium, and magnesium, significantly improving hardness, wear resistance, and corrosion resistance, and imparting functional properties such as insulation, coloring, and dielectric properties. Electrochemical oxidation processes are classified into sulfuric acid anodizing, hard anodizing, and micro-arc oxidation, depending on the electrolyte composition and power supply mode, and are widely used in aerospace, automotive, electronics, and architectural decoration fields.

[0003] Micro-arc oxidation, also known as plasma electrolytic oxidation, is developed based on conventional anodic oxidation. During the micro-arc oxidation process, when the contact between the anode and the workpiece becomes loose, typical ablation morphology easily appears in the contact area between the anode and the workpiece. The oxide film around the ablated area peels off in layers due to thermal shock; the metal oxide particles precipitated in the electrolyte re-sinter and adhere to form black nodule-like protrusions; the macroscopic manifestation is irregular gray-black spots, accompanied by a pungent ozone odor, and the insulation performance and corrosion resistance of the film layer are significantly reduced.

[0004] Therefore, it is necessary to design an anode tooling for micro-arc oxidation to protect the anode contact area of ​​the workpiece from ablation. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide an anode tooling for micro-arc oxidation with reasonable structure and convenient operation, which can effectively improve the uniformity of oxide film on the surface of workpiece and protect the anode contact area of ​​workpiece from ablation.

[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: an anode tooling for micro-arc oxidation, characterized in that: it includes a rotating shaft and a workpiece fixing assembly. The rotating shaft includes a first straight rod and a second straight rod. The rear end of the first straight rod is connected to the front end of the second straight rod through a pin. The front end of the first straight rod is connected to the positive terminal of the oxidation power source. The rear section of the second straight rod is an external thread section. The workpiece fixing assembly is set on the external thread section. The workpiece fixing assembly includes a positioning nut, an annular spring support plate, and a fastening nut. The outer diameter of the annular spring support plate is smaller than the inner diameter of the workpiece fixing hole. The outer diameters of the positioning nut and the fastening nut are larger than the inner diameter of the workpiece fixing hole. The positioning nut is threadedly sleeved on the upper part of the external thread section. The annular spring support plate is sleeved on the external thread section and abuts against the positioning nut. The workpiece is sleeved outside the annular spring support plate and is positioned by tightening the fastening nut. The upper and lower ends of the workpiece abut against the positioning nut and the fastening nut, respectively, for sealing.

[0007] As an improvement, the annular spring support plate includes an upper ring and a lower ring, which are connected by a number of spring plates. The spring plates are elastic metal plates with an outward arc protrusion in the middle, and the spring plates are evenly spaced along the circumference.

[0008] Furthermore, the positioning nut and the fastening nut have the same structure. The positioning nut and the fastening nut are hexagonal nuts, and one end of the positioning nut and the fastening nut is formed with a tapered section with a reduced diameter. The tapered section has an internal thread hole corresponding to the external thread section. The outer diameter of the upper ring and the lower ring is equal to the outer diameter of the end face of the tapered section of the positioning nut and the fastening nut. The outer diameter of the end face of the tapered section is smaller than the inner diameter of the workpiece fixing hole. During assembly, the tapered section of the positioning nut is screwed downward into the external thread section of the second straight rod, and the tapered section of the fastening nut is screwed upward into the external thread section of the second straight rod. The tapered sections of the two nuts are inserted into the workpiece fixing hole, forming a closed area inside the workpiece fixing hole.

[0009] Furthermore, both the first and second straight rods are metal rods. The first straight rod is a cylindrical rod with a U-shaped connecting seat at its rear end. The U-shaped connecting seat has pin holes at both ends. The front end of the second straight rod has a connecting cylinder that mates with the U-shaped connecting seat. The connecting cylinder has a through hole in the middle that corresponds to the pin hole. The second straight rod is inserted into the U-shaped connecting seat through the connecting cylinder. The pin passes through the pin hole of the U-shaped connecting seat, the through hole of the connecting cylinder, and another pin hole of the U-shaped connecting seat to rotatably connect the first and second straight rods together.

[0010] Furthermore, the positioning nut and the fastening nut are metal nuts, and the surface of the metal nut, except for the inner wall of the central threaded hole, is covered with a polymer coating layer.

[0011] Furthermore, the first straight rod has a polymer coating layer covering the outer wall of the pin hole, and the second straight rod has a polymer coating layer covering the outer wall of the pin hole and the surface of the external thread.

[0012] Furthermore, the polymer coating layer is a polytetrafluoroethylene coating layer.

[0013] Finally, the spring sheets are four evenly spaced spring sheets, and the material of the spring sheets is titanium alloy.

[0014] Compared with the prior art, the advantages of this utility model are as follows: The rotating shaft includes a first straight rod and a second straight rod, which are connected by a pin. The first straight rod is connected to the anode. When the axis of the clamping and fixing hole is not on the center of gravity of the workpiece, the second straight rod can deviate from the vertical line of the center of gravity at a certain angle, which avoids the entire anode rod tilting and causing the workpiece to deviate from the preset oxidation position, thereby improving the uniformity of the oxide film on the surface of the workpiece. The second straight rod is provided with a workpiece fixing component. After the workpiece is assembled, a closed area is formed inside the workpiece fixing hole. This ensures that there is no electrolyte distribution in the contact area between the anode and the workpiece, which can suppress the ablation phenomenon in the anode fixing point area during the oxidation process and improve the overall quality of the oxide film on the surface of the workpiece.

[0015] This utility model has a reasonable structural design and is easy to operate. It isolates the contact area between the workpiece and the anode, greatly reducing the impact of ablation caused by violent discharge in the contact area on the quality of the oxide film, effectively improving the uniformity of the oxide film on the workpiece surface, protecting the anode contact area of ​​the workpiece from ablation, and improving production efficiency. Attached Figure Description

[0016] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model;

[0017] Figure 2 This is a structural diagram of the first straight rod;

[0018] Figure 3 This is a structural diagram of the second straight rod;

[0019] Figure 4 This is a schematic diagram of the structure of the annular spring support plate;

[0020] Figure 5 This is a structural diagram of a positioning nut / fastening nut. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0022] like Figures 1-5As shown, an anode tooling for micro-arc oxidation includes a rotating shaft A and a workpiece fixing assembly B. The rotating shaft A includes a first straight rod 1 and a second straight rod 2. The rear end of the first straight rod 1 is rotatably connected to the front end of the second straight rod 2 via a pin 3. The front end of the first straight rod 1 is connected to the positive terminal of the oxidation power source. The rear section of the second straight rod 2 is an external thread section 21. The workpiece fixing assembly B is disposed on the external thread section 21. The workpiece fixing assembly B includes a positioning nut 4, an annular spring support plate 5, and a fastening nut 6, which are sequentially sleeved on the external thread section 21. The outer diameter of the annular spring support plate 5 is smaller than the inner diameter of the workpiece fixing hole. The outer diameters of the positioning nut 4 and the fastening nut 6 are larger than the inner diameter of the workpiece fixing hole. The positioning nut 4 is threaded onto the upper part of the external thread section 21. The annular spring support plate 5 is sleeved on the external thread section 21 and abuts against the positioning nut 4. The workpiece is sleeved outside the annular spring support plate 5 and is positioned by tightening the fastening nut 6. The upper and lower ends of the workpiece abut against the positioning nut 4 and the fastening nut 6, respectively, for sealing.

[0023] The specific structure is as follows: both the first straight rod 1 and the second straight rod 2 are metal rods. The first straight rod 1 is a cylindrical rod. The rear end of the first straight rod 1 is provided with a U-shaped connecting seat 11. The two ends of the U-shaped connecting seat 11 are provided with pin holes 12. The front end of the second straight rod 2 is provided with a connecting cylinder 22 that cooperates with the U-shaped connecting seat 11. The middle part of the connecting cylinder 22 is provided with a through hole 23 corresponding to the pin hole 12. The second straight rod 2 is inserted into the U-shaped connecting seat 11 through the connecting cylinder 22. The pin 3 passes through the pin hole 12 of the U-shaped connecting seat 11, the through hole 23 of the connecting cylinder 22, and another pin hole 12 of the U-shaped connecting seat 11 to rotatably connect the first straight rod 1 and the second straight rod 2 together. The annular spring support plate 5 includes an upper ring 51 and a lower ring 52. The upper ring 51 and the lower ring 52 are connected by a number of spring plates 53. The spring plates 53 are elastic metal plates with an outward arc protrusion in the middle. In this embodiment, the spring plates 53 have four titanium alloy spring plates at the tail. The four spring plates 53 are evenly spaced along the circumference.

[0024] The positioning nut 4 and the fastening nut 6 have the same structure. The positioning nut 4 and the fastening nut 6 are hexagonal nuts. One end of the positioning nut 4 and the fastening nut 6 is formed with tapered sections 41 and 61 with reduced diameter. The tapered sections 41 and 61 have threaded holes corresponding to the internal threaded holes of the nuts, that is, they have internal threaded holes corresponding to the external threaded sections. The outer diameter of the upper ring 51 and the lower ring 52 is equal to the outer diameter of the end faces of the tapered sections 41 and 61 of the positioning nut 4 and the fastening nut 6. The outer diameter of the end faces of the tapered sections 41 and 61 is smaller than the inner diameter of the workpiece fixing hole. During assembly, the tapered section 41 of the positioning nut 4 is screwed downward into the external threaded section 21 of the second straight rod 2, and the tapered section 61 of the fastening nut 6 is screwed upward into the external threaded section of the second straight rod 2. The tapered sections 41 and 61 of the two nuts are inserted into the workpiece fixing hole, forming a closed area inside the workpiece fixing hole.

[0025] The positioning nut 4 and the fastening nut 6 are metal nuts. The surfaces of the metal nuts, except for the inner wall of the central threaded hole, are covered with polymer coating layers 42 and 62, which are polytetrafluoroethylene coating layers.

[0026] The first straight rod 1 is covered with a polymer coating layer except for the inner wall of the pin hole. The second straight rod 2 is covered with a polymer coating layer except for the inner wall of the pin hole and the surface of the external thread. The polymer coating layer is a polytetrafluoroethylene coating layer.

[0027] In this embodiment, the first straight rod 1, the second straight rod 2, the pin 3, the positioning nut 4, and the fastening nut 5 are made of titanium alloy.

[0028] The working principle is as follows:

[0029] First, assemble the first straight rod 1 and the second straight rod 2. Then, screw the positioning nut 4 to the appropriate position at the upper end of the external thread section 21 of the second straight rod 2. Next, insert the annular spring support piece 5. Then, insert the assembled part, the lower end of the second straight rod 2, into the fixing hole of the workpiece to be processed. Finally, tighten the fastening nut 6 so that the four spring pieces 53 of the annular spring support piece 5 bulge out in the middle due to the pressure at both ends, and contact the inner wall of the fixing hole of the workpiece to be processed. During the tightening process of the fastening nut 6, the distance between the positioning nut 4 and the fastening nut 6 decreases. The conical sections 41 and 61 of the positioning nut 4 and the fastening nut 6 are engaged with the upper and lower end faces of the fixing hole of the workpiece to be processed, thereby forming a closed area inside the fixing hole.

[0030] When clamping a workpiece whose axis of the fixing hole is not on the workpiece's center of gravity, the second straight rod 2 can deviate from the vertical line of the center of gravity at a certain angle, which avoids the entire anode rod tilting and causing the workpiece to deviate from the preset oxidation position, thereby improving the uniformity of the oxide film on the workpiece surface.

[0031] The enclosed anode-workpiece contact area design ensures that there is no electrolyte distribution in the contact area, which can suppress the ablation phenomenon in the anode fixed point area during the oxidation process and improve the overall quality of the oxide film on the workpiece surface.

[0032] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An anode tooling for micro-arc oxidation, characterized in that: The device includes a rotating shaft and a workpiece fixing assembly. The rotating shaft consists of a first straight rod and a second straight rod. The rear end of the first straight rod is rotatably connected to the front end of the second straight rod via a pin. The front end of the first straight rod is connected to the positive terminal of an oxidation power source. The rear section of the second straight rod is an externally threaded section. The workpiece fixing assembly is mounted on the externally threaded section and includes a positioning nut, an annular spring support plate, and a fastening nut. The outer diameter of the annular spring support plate is smaller than the inner diameter of the workpiece fixing hole. The outer diameters of the positioning nut and the fastening nut are larger than the inner diameter of the workpiece fixing hole. The positioning nut is threaded onto the upper part of the externally threaded section. The annular spring support plate is mounted on the externally threaded section and abuts against the positioning nut. The workpiece is mounted outside the annular spring support plate and is positioned by tightening the fastening nut. The upper and lower ends of the workpiece abut against the positioning nut and the fastening nut, respectively, for sealing.

2. The anode tooling for micro-arc oxidation according to claim 1, characterized in that: The annular spring support plate includes an upper ring and a lower ring, which are connected by a number of spring plates. The spring plates are elastic metal plates with an outward arc protrusion in the middle, and the spring plates are evenly spaced along the circumference.

3. The anode tooling for micro-arc oxidation according to claim 2, characterized in that: The positioning nut and the fastening nut have the same structure. The positioning nut and the fastening nut are hexagonal nuts. One end of the positioning nut and the fastening nut is formed with a tapered section with a reduced diameter. The tapered section has an internal thread hole corresponding to the external thread section. The outer diameter of the upper ring and the lower ring is equal to the outer diameter of the end face of the tapered section of the positioning nut and the fastening nut. The outer diameter of the end face of the tapered section is smaller than the inner diameter of the workpiece fixing hole. During assembly, the tapered section of the positioning nut is screwed downward into the external thread section of the second straight rod, and the tapered section of the fastening nut is screwed upward into the external thread section of the second straight rod. The tapered sections of the two nuts are inserted into the workpiece fixing hole, forming a closed area inside the workpiece fixing hole.

4. The anode tooling for micro-arc oxidation according to claim 3, characterized in that: Both the first and second straight rods are metal rods. The first straight rod is a cylindrical rod with a U-shaped connecting seat at its rear end. The U-shaped connecting seat has pin holes at both ends. The front end of the second straight rod has a connecting cylinder that mates with the U-shaped connecting seat. The connecting cylinder has a through hole in the middle that corresponds to the pin hole. The second straight rod is inserted into the U-shaped connecting seat through the connecting cylinder. The pin passes through the pin hole of the U-shaped connecting seat, the through hole of the connecting cylinder, and another pin hole of the U-shaped connecting seat to rotatably connect the first and second straight rods together.

5. The anode tooling for micro-arc oxidation according to any one of claims 1 to 4, characterized in that: The positioning nut and the fastening nut are metal nuts, and the surface of the metal nut, except for the inner wall of the central threaded hole, is covered with a polymer coating layer.

6. The anode tooling for micro-arc oxidation according to claim 5, characterized in that: The first straight rod is covered with a polymer coating layer on the outer wall of the pin hole, and the second straight rod is covered with a polymer coating layer on the outer wall of the pin hole and the surface of the external thread.

7. The anode tooling for micro-arc oxidation according to claim 6, characterized in that: The polymer coating layer is a polytetrafluoroethylene coating layer.

8. The anode tooling for micro-arc oxidation according to any one of claims 2 to 4, characterized in that: The spring sheets are four evenly spaced spring sheets, and the spring sheets are made of titanium alloy.

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