Electrochemical mechanical composite polishing system and polishing method for inner wall of metal pipeline

Abstract

The invention discloses an electrochemical mechanical composite polishing system and method for the inner wall of a metal pipeline. The polishing system comprises ion exchange resin and a flexible electrode which are matched for use, and a flexible brush is arranged on the flexible electrode; during polishing, the flexible electrode is inserted into the metal pipeline, the pipeline space is filled with the ion exchange resin, then a power source is connected, a channel is formed among the flexible electrode, the ion exchange resin and the metal pipeline, at the moment, the protrusions on the inner wall of the metal pipeline are subjected to electrochemical reaction preferentially, electrochemical passivators easier to remove are generated, and then the metal pipeline is subjected to polishing. By moving or rotating the flexible electrode, the ion exchange resin and the flexible brush move relative to the metal pipeline, electrochemical passivators are removed, finally, the inner wall of the metal pipeline is polished, and the polishing efficiency is high; and the electrode and the brush have flexibility, so that the device can adapt to metal pipelines with different bending degrees, the consistency of electrochemical reactions in all parts of the metal pipelines is ensured, and the polishing quality is good.

Description

Technical Field

[0001] The invention relates to the technical field of metal pipeline inner wall polishing, and in particular to an electrochemical mechanical composite polishing system and a polishing method for the inner wall of a metal pipeline. Background Art

[0002] In the fields of pharmaceuticals and food equipment, the cleanliness of the metal pipes used is required to be high. Therefore, after the metal pipes are processed, their inner walls need to be polished to reduce the friction between the materials and the metal pipes, reduce the accumulation of materials in the metal pipes during transportation, and prevent the metal pipes from being blocked.

[0003] The traditional method of polishing the inner wall of metal pipes is to use a polishing head: first, wrap the polishing cloth around the polishing head and press the polishing head into the metal pipe. Then, the staff rotates the drive shaft connected to the polishing head to drive the polishing head to rotate and polish the inner wall of the pipe. However, there are many uncertainties when polishing in this way, making it difficult to achieve efficient polishing. For example, the size matching of the emery cloth wrapped around the polishing head and the inner diameter of the pipe, as well as the contact state between the emery cloth and the inner wall of the pipe, usually depends on the experience of the operator; once there is a problem with the winding method of the polishing cloth, or the contact pressure between the emery cloth and the inner wall of the pipe is too large, it is easy to cause the polishing head to get stuck in the pipe; especially when there are corners in the pipe, it is difficult for the polishing head to polish the bends where the curvature of the pipe changes greatly, and the polishing quality cannot be guaranteed. In addition, the interior of complex metal pipes made by additive manufacturing technology needs to be polished more, but the shape of such metal pipes is relatively complex, and traditional polishing technology is difficult to achieve good polishing quality and polishing efficiency. Summary of the invention

[0004] The present invention provides an electrochemical mechanical composite polishing system for the inner wall of a metal pipe, which is used to overcome the above-mentioned problems existing in the prior art. The electrochemical mechanical composite polishing system for the inner wall of a metal pipe of the present invention comprises an ion exchange resin and a flexible electrode used in combination, wherein a flexible brush is provided on the flexible electrode, which can mechanically polish the inner wall of the metal pipe; during polishing, the flexible electrode is inserted into the metal pipe, and the ion exchange resin is filled in the pipe space. After connecting to the power supply, a passage can be formed between the flexible electrode, the ion exchange resin and the metal pipe, and an electrochemical reaction occurs preferentially at the protrusion of the inner wall of the metal pipe, producing an electrochemical passivation product that is easier to remove; and then the electrochemical passivation product is removed by rotating or moving the flexible electrode, so that the inner wall of the metal pipe can be polished, and the polishing efficiency is high; in addition, the electrode and the brush are flexible and can adapt to metal pipes with different degrees of curvature, which can ensure the consistency of the electrochemical reaction at various places inside the metal pipe, and can mechanically remove the material at any point inside the metal pipe, thereby ensuring the consistency of the polishing quality inside the pipe, and the polishing quality is good. Correspondingly, the present application also provides an electrochemical mechanical composite polishing method for the inner wall of a metal pipe.

[0005] For the polishing system, the technical solution of this application is:

[0006] The electrochemical mechanical composite polishing system for the inner wall of a metal pipe comprises an ion exchange resin and a flexible electrode used together; the flexible electrode comprises a polishing spindle, and an external power supply unit and a hand-held unit arranged at both ends of the polishing spindle; a plurality of flexible brush rods are arranged at intervals on the polishing spindle; one end of the flexible brush rod is fixedly connected to the polishing spindle, and the other end is provided with a flexible brush; the hand-held unit is provided with insulating material; when in use, the polishing spindle is located inside the metal pipe, the flexible brush is in contact with the inner wall of the metal pipe, and the ion exchange resin is filled between the flexible electrode and the inner wall of the metal pipe.

[0007] Compared with the prior art, the electrochemical mechanical composite polishing system for the inner wall of a metal pipe of the present application comprises an ion exchange resin and a flexible electrode used in combination, wherein a flexible brush is arranged on the flexible electrode, and the inner wall of the metal pipe can be mechanically polished; during polishing, the flexible electrode is inserted into the metal pipe, and the ion exchange resin is filled in the pipe space. After the power supply is connected, a passage can be formed between the flexible electrode, the ion exchange resin and the metal pipe. At this time, an electrochemical reaction will preferentially occur at the protrusions on the inner wall of the metal pipe, producing electrochemical passivation products that are easier to remove, and then the flexible brush and the flexible electrode are rotated or moved to allow the flexible brush and the metal pipe to passivate the metal pipe. Relative movement is generated between the ion exchange resin and the metal pipe, and the generated electrochemical passivation products are removed, so that the inner wall of the metal pipe can be polished with high polishing efficiency. Moreover, the electrode and the brush are flexible and can adapt to metal pipes with different degrees of curvature, which can not only ensure the consistency of the electrochemical reaction at various locations inside the metal pipe, but also mechanically remove the material at any point inside the metal pipe, thereby ensuring the consistency of the polishing quality inside the pipe and good polishing quality. In addition, compared with the polishing head, the flexible brush has a compact structure and is more suitable for the inner walls of metal pipes of different structures, making polishing more convenient, with a longer service life and low production cost.

[0008] As an optimization, in the aforementioned electrochemical mechanical composite polishing system for the inner wall of the metal pipe, the flexible brush rods can be distributed in a circular pattern along the length direction of the flexible electrode. Thus, during polishing, the flexible brush can more comprehensively cover the inner wall surface of the metal pipe, further improving the polishing efficiency, and the flexible brush can provide a uniform polishing force during the rotational motion, reducing the pressure concentration on a specific area, thereby reducing the risk of damaging the inner wall surface of the metal pipe.

[0009] Alternatively, the flexible brush rods can also be distributed in a spiral shape along the length direction of the flexible electrode. The spiral distribution allows the flexible brushes to be closely arranged on the flexible electrode, thereby improving the polishing efficiency; and can also better adapt to the inner walls of metal pipes of different shapes, thereby providing strong flexibility in use.

[0010] As an optimization, in the aforementioned electrochemical mechanical composite polishing system for the inner wall of a metal pipe, the polishing spindle can be cylindrical or square. Currently, circular metal pipes and square metal pipes are the most widely used; therefore, in this application, the polishing spindle is designed to be cylindrical or square, corresponding to the structure of the metal pipe, so as to facilitate the insertion of the flexible electrode into the metal pipe during polishing.

[0011] As an optimization, in the aforementioned electrochemical mechanical composite polishing system for the inner wall of the metal pipe, the flexible brush is tilted on the flexible brush rod, so that when the flexible electrode moves, the flexible brush can better contact the inner wall of the metal pipe, ensuring high polishing efficiency.

[0012] As an optimization, in the aforementioned electrochemical mechanical composite polishing system for the inner wall of the metal pipe, the flexible electrode can be made of steel wire or copper. In this case, the flexible electrode has high tensile strength and toughness, can withstand repeated bending and friction without being easily damaged, and has a long service life.

[0013] For the polishing method, the technical solution of this application is:

[0014] A method for electrochemical mechanical composite polishing of the inner wall of a metal pipe, the method adopts the aforementioned electrochemical mechanical composite polishing system for the inner wall of a metal pipe of the present application to polish the inner wall of the metal pipe; specifically comprises the following steps: S1, inserting a flexible electrode into the metal pipe to be polished, so that the polishing spindle is located inside the metal pipe, and the flexible brush is in contact with the inner wall of the metal pipe; at the same time, using ion exchange resin to fill the remaining space between the flexible electrode and the metal pipe; S2, connecting the outer surface of the metal pipe to the positive pole of a DC power supply, connecting the external power supply part of the flexible electrode to the negative pole of the DC power supply, so that a passage is formed between the metal pipe, the ion exchange resin and the flexible electrode; at this time, the protrusions on the inner wall of the metal pipe will preferentially undergo an electrochemical reaction to produce electrochemical passivation products; S3, the staff grasps the handheld part of the flexible electrode, rotates or moves the flexible electrode back and forth, so that the flexible brush and the ion exchange resin produce relative movement with the metal pipe, removes the electrochemical passivation products, and realizes polishing of the inner wall of the metal pipe.

[0015] Compared with the prior art, the electrochemical mechanical composite polishing method for the inner wall of a metal pipe of the present application inserts a flexible electrode with a flexible brush into the interior of the metal pipe, fills ion exchange resin in the remaining space of the metal pipe, and then connects to a power source. Based on the electrolytic polishing principle of a metal solid medium, electrochemical passivates that are easier to remove are preferentially produced at the protrusions of the inner wall of the metal pipe. Finally, the electrochemical passivates are removed by rotating or moving the flexible electrode to achieve polishing of the inner wall of the metal pipe. This method combines the two technologies of electrochemical and mechanical polishing to improve the polishing efficiency. In addition, the electrode and the brush are flexible, and are more adaptable to the polishing of the bends of the metal pipe. This can reduce mechanical damage to the workpiece surface during polishing, ensure the consistency of the polishing quality inside the pipe, and is suitable for polishing workpieces with complex structures.

[0016] As an optimization, in the aforementioned electrochemical mechanical composite polishing method for the inner wall of a metal pipe, the polishing spindle is cylindrical or square; before polishing, a flexible electrode with a corresponding structure is selected according to the shape of the metal pipe to be polished. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the structure of the flexible electrode in this application (the polishing spindle is cylindrical);

[0018] Figure 2 Is adopted Figure 1 The state diagram of the flexible electrode when polishing a metal round tube;

[0019] Figure 3 It is a schematic diagram of the structure of the flexible electrode in this application (the polishing spindle is in the shape of a square column);

[0020] Figure 4 Is adopted Figure 3 The state diagram of the flexible electrode when polishing a metal square tube;

[0021] Figure 5 yes Figure 2 Schematic diagram of the flexible electrode and the metal tube when electricity is applied;

[0022] Figure 6 It is a polishing principle diagram of the electrochemical mechanical composite polishing system of the present application;

[0023] Figure 7 This is the schematic diagram of the electrolytic polishing of metal solid medium;

[0024] Figure 8 It is a schematic diagram of the ion exchange process on the surface of GH4169 alloy;

[0025] Fig. 9 is the initial surface roughness of the round tube in the embodiment of the present application;

[0026] Fig.10 yes Fig. 9 The surface roughness of the round tube after being polished by the polishing system of the present application;

[0027] Fig.11 yes Fig. 9 The surface roughness of the round tube after polishing with a traditional flap wheel.

[0028] The markings in the attached drawings are: 1-ion exchange resin; 2-flexible electrode, 21-polishing spindle, 22-external power supply unit, 23-handheld unit, 24-flexible brush rod, 25-flexible brush; 3-metal pipe; 4-electrochemical passivation agent. DETAILED DESCRIPTION

[0029] The present application is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present application.

[0030] Metal pipes used in the fields of pharmaceuticals and food equipment need to be polished after processing. In the prior art, polishing with a polishing head is usually used, which is difficult to achieve good polishing quality and polishing efficiency. Therefore, the present application provides an electrochemical mechanical composite polishing system for the inner wall of a metal pipe.

[0031] See also Figure 1 and Figure 2 The electrochemical mechanical composite polishing system for the inner wall of a metal pipe of the present application comprises an ion exchange resin 1 and a flexible electrode 2 used together; the flexible electrode 2 comprises a polishing spindle 21, and an external power supply unit 22 and a hand-held unit 23 arranged at both ends of the polishing spindle 21; a plurality of flexible brush rods 24 are arranged at intervals on the polishing spindle 21; one end of the flexible brush rod 24 is fixedly connected to the polishing spindle 21, and the other end is provided with a flexible brush 25; the hand-held unit 23 is provided with an insulating material. During polishing, the flexible electrode 2 is inserted into the metal pipe 3 to be polished, so that the polishing spindle 21 is located inside the metal pipe 3, and the flexible brush 25 is in contact with the inner wall of the metal pipe 3, and the ion exchange resin 1 is filled between the flexible electrode 2 and the inner wall of the metal pipe 3; then the power supply is connected to form a passage between the flexible electrode 2, the ion exchange resin 1 and the metal pipe 3. At this time, an electrochemical reaction will preferentially occur at the protrusions on the inner wall of the metal pipe 3, producing electrochemical passivation products that are easier to remove; finally, by rotating or moving the flexible electrode 2, the generated electrochemical passivation products can be removed, thereby achieving polishing of the inner wall of the metal pipe 3.

[0032] This application combines the electrolytic polishing theory and the working principle of ion exchange resin to explain the working principle of electrolytic polishing of metal solid media. GH4169 alloy is used as a sample, the sample is clamped at the bottom of the anode power supply and placed in an insulating barrel; a steel foil is fixed on the inner edge of the barrel opposite to the sample, which serves as a cathode; the insulating barrel is filled with ion exchange resin particles (see Figure 7 ). For the specific principle of electrolytic polishing, see Figure 8 When the diameter of the resin particles is much larger than the two peak sizes of the microscopic rough surface, the resin particles make point contact with the material surface and form a micro-electrolyzer contact point at this point; the components on the surface of the GH4169 alloy material lose electrons under the action of the electric potential to form Ni + , Fe 2+ / Fe 3+ Cr 3+ Plasma enters the micro-electrolyzer and diffuses to the resin particles; at this time, the transfer of metal cations dissolved by electrochemistry relies on ion exchange resin to achieve transmission, that is, when the resin particles leave the sample surface, Ni + , Fe 2+ / Fe 3+ Cr 3+ The plasma is adsorbed and in the continuous relative motion, these ions are transferred away.

[0033] Example:

[0034] In this embodiment, the polishing spindle 21 is cylindrical; the flexible brush rod 24 is distributed in a circumference along the length direction of the flexible electrode 2. Therefore, during polishing, the flexible brush 24 can more comprehensively cover the inner wall surface of the metal pipe 3, further improving the polishing efficiency, and the flexible brush 24 can provide a uniform polishing force during the rotational motion, reducing the pressure concentration on a specific area, thereby reducing the risk of damaging the inner wall surface of the metal pipe 3.

[0035] In this embodiment, the flexible brush 25 is tiltedly arranged on the flexible brush rod 24. Therefore, when the flexible electrode 2 moves, the flexible brush 24 can better contact the inner wall of the metal pipe 3, thereby ensuring high polishing efficiency.

[0036] In this embodiment, the flexible electrode 2 is made of steel wire, which has high tensile strength and toughness, and can withstand repeated bending and friction without being easily damaged, so that the service life of the flexible electrode 2 is long.

[0037] In this embodiment, the applicant uses the aforementioned electrochemical mechanical composite polishing system for the inner wall of the metal pipe to polish the inner wall of the metal round tube made of 316L material; the diameter of the round tube is 100mm, and the initial surface roughness is 960nm (see Fig. 9 ).

[0038] The specific steps of polishing are as follows:

[0039] S1, insert the flexible electrode 2 into the metal tube to be polished, so that the polishing spindle 21 is located inside the metal tube, and the flexible brush 25 is in contact with the inner wall of the metal tube; at the same time, the ion exchange resin 1 is used to fill the remaining space between the flexible electrode 2 and the metal tube;

[0040] S2, connect the outer surface of the metal tube to the positive electrode of the DC power supply, and connect the external power supply part 22 of the flexible electrode 2 to the negative electrode of the DC power supply (see Figure 5 ), so that a passage is formed between the metal tube, the ion exchange resin 1 and the flexible electrode 2; at this time, the protrusions on the inner wall of the metal tube will preferentially undergo an electrochemical reaction to produce an electrochemical passivation product 4;

[0041] During the polishing process, since the polishing medium is solid resin microsphere particles between micrometer and millimeter scales, and its diameter is much larger than the distance between two adjacent surface peaks, the material can only be dissolved from the higher peaks on the surface during polishing, so that electrochemical passivation products will be preferentially generated at the protrusions on the inner wall of the metal tube 4;

[0042] S3, the staff grasps the hand-held portion 23 of the flexible electrode 2, rotates or moves the flexible electrode 2 forward and backward, so that the flexible brush 25 and the ion exchange resin 1 and the metal tube move relative to each other, and removes the electrochemical passivation product 4 (see Figure 6 ), to achieve polishing of the inner wall of the metal round tube.

[0043] After the metal tube was polished for 20 minutes according to the above steps, the surface roughness of the inner wall of the tube was reduced to 15nm (see Fig.10 ).

[0044] In order to verify that the polishing system of the present application has a higher material removal efficiency, the applicant used a conventional flap wheel to polish a 316L metal round tube with the same initial roughness of 960nm as a comparison; after polishing for 20 minutes, the surface roughness of the inner wall of the round tube decreased to 121nm (see Fig.11 ). It can be seen that the material removal rate of the polishing system of the present application is better.

[0045] The above general description of the invention involved in this application and the description of its specific implementation methods should not be understood as limiting the technical solution of the invention. In the above embodiment, the metal pipe 3 to be polished is a round pipe; of course, the solution of the present invention can also be used to polish metal pipes of other shapes, such as square pipes (in order to adapt to the shape of the pipe, the polishing spindle 21 of the flexible electrode 2 can be designed as a square column, see Figure 3 and Figure 4 ). Based on the disclosure of this application, those skilled in the art may, without violating the constituent elements of the invention involved, add, reduce or combine the disclosed technical features in the above general description or / and specific implementation methods (including examples) to form other technical solutions within the protection scope of this application.

Claims

1. The electrochemical mechanical composite polishing system for the inner wall of metal pipes is characterized by: The invention comprises an ion exchange resin (1) and a flexible electrode (2) for use together; the flexible electrode (2) comprises a polishing spindle (21), and an external power supply unit (22) and a hand-held unit (23) arranged at both ends of the polishing spindle (21); a plurality of flexible brush rods (24) are arranged at intervals on the polishing spindle (21); one end of the flexible brush rod (24) is fixedly connected to the polishing spindle (21), and the other end is provided with a flexible brush (25); an insulating material is arranged on the hand-held unit (23); when in use, the polishing spindle (21) is located inside a metal pipe (3), the flexible brush (25) is in contact with the inner wall of the metal pipe (3), and the ion exchange resin (1) is filled between the flexible electrode (2) and the inner wall of the metal pipe (3).

2. The electrochemical mechanical composite polishing system for inner wall of metal pipe according to claim 1, characterized in that: The flexible brush rods (24) are distributed in a circular pattern along the length direction of the flexible electrode (2).

3. The electrochemical mechanical composite polishing system for inner wall of metal pipe according to claim 1, characterized in that: The flexible brush rod (24) is distributed in a spiral shape along the length direction of the flexible electrode (2).

4. The electrochemical mechanical composite polishing system for the inner wall of a metal pipeline according to claim 2 or 3, characterized in that: The polishing spindle (21) is cylindrical.

5. The electrochemical mechanical composite polishing system for the inner wall of a metal pipeline according to claim 2 or 3, characterized in that: The polishing spindle (21) is in the shape of a square column.

6. The electrochemical mechanical composite polishing system for inner wall of metal pipe according to claim 1, characterized in that: The flexible brush (25) is arranged obliquely on the flexible brush rod (24).

7. The electrochemical mechanical composite polishing system for inner wall of metal pipe according to claim 6, characterized in that: The flexible electrode (2) is made of steel wire or copper.

8. The electrochemical mechanical composite polishing method for the inner wall of a metal pipeline is characterized by: The method uses the electrochemical mechanical composite polishing system for the inner wall of the metal pipe as claimed in claim 1 to polish the inner wall of the metal pipe; specifically comprises the following steps: S1, inserting the flexible electrode (2) into the metal pipe (3) to be polished, so that the polishing spindle (21) is located inside the metal pipe (3), and the flexible brush (25) is in contact with the inner wall of the metal pipe (3); at the same time, using the ion exchange resin (1) to fill the remaining space between the flexible electrode (2) and the metal pipe (3); S2, connecting the outer surface of the metal pipe (3) to the positive electrode of a DC power supply, and connecting the external power supply unit (22) of the flexible electrode (2) to the negative electrode of the DC power supply, so that a passage is formed between the metal pipe (3), the ion exchange resin (1) and the flexible electrode (2); at this time, the protrusions on the inner wall of the metal pipe (3) will preferentially undergo an electrochemical reaction to produce an electrochemical passivation product (4); S3, the staff member grasps the hand-held portion (23) of the flexible electrode (2), rotates or moves the flexible electrode (2) back and forth, so that the flexible brush (25) and the ion exchange resin (1) generate relative movement with the metal pipe (3), removes the electrochemical passivation product (4), and achieves polishing of the inner wall of the metal pipe (3).

9. The electrochemical mechanical composite polishing method for the inner wall of a metal pipeline according to claim 8, characterized in that: The polishing spindle (21) is cylindrical or square; before polishing, a flexible electrode (2) with a corresponding structure is selected according to the shape of the metal pipe (3) to be polished.

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