U-shaped pipe electroplating device

Abstract

The application discloses a U-shaped pipeline electroplating device and belongs to the technical field of pipeline electroplating, comprising a track frame, a plurality of electroplating tanks are arranged below the track frame, a moving unit is assembled on the track frame, and the moving unit comprises a transverse moving frame which is slidably installed on the track frame. Through the hanging and placing unit, the U-shaped pipe can be horizontally hung and placed or obliquely hung and placed. Through the plug-in cooperation of the positioning insert block and the horizontal positioning insert slot and the oblique positioning insert slot, the horizontal hanging and placing and the oblique hanging and placing of the U-shaped pipe can be quickly switched. In the horizontal posture, the axis of the straight pipe section of the U-shaped pipe is horizontal, the elbow extends outward, the concave surface of the elbow is vertically oriented, the inverted U-shaped vertical suspension and the inverted buckle gas holding structure of the traditional inverted U-shaped pipe are completely broken, the hydrogen bubbles generated by electrolysis can directly float and escape under the action of the buoyancy, and the industry pain point that the concave surface of the elbow is prone to pinhole and pitting defects is solved from the root.

Description

Technical Field

[0001] This invention relates to the field of pipe electroplating technology, and more particularly to a U-shaped pipe electroplating device. Background Technology

[0002] U-shaped pipes are widely used in heat exchange and refrigeration. Copper plating on the outer wall is a core surface treatment process to improve the corrosion resistance, conductivity and weldability of the pipe. Currently, large-scale pipe electroplating production lines generally adopt a trolley-type transfer structure, which uses a track-type moving unit to drive the hangers to complete the flow and lifting of multiple processes such as degreasing, activation, electroplating, and water washing between tanks.

[0003] For clamping U-shaped pipes, the industry mainstream adopts vertical suspension fixtures, which are divided into two basic forms: upright U-shaped suspension with the bend facing down and inverted U-shaped suspension with the bend facing up.

[0004] In actual industrial mass production applications, existing U-shaped pipe electroplating equipment still has defects: When using inverted U-shaped suspension, the concave surface of the elbow faces downward to form an inverted gas-collecting structure. Hydrogen bubbles generated by electrolysis continuously accumulate on the concave surface due to buoyancy and cannot escape naturally, which will form dense pinholes and pits on the coating surface, and even cause localized incomplete plating; When using upright U-shaped suspension, the elbow is at the lowest point of the entire pipe. When exiting the tank, a large amount of residual plating solution will be carried in, which will not only cause material loss of plating solution, but also easily cross-contaminate the tank solution of subsequent processes, increasing operation and maintenance costs; At the same time, in the vertical suspension state, there are differences in current edge effect and chemical concentration gradient at the upper and lower ends of the pipe, resulting in poor uniformity of axial coating thickness and insufficient consistency of coating adhesion between the bent section and the straight section. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that when using an inverted U-shaped suspension, the inner concave surface of the bend faces downward to form an inverted gas-collecting structure, and the hydrogen bubbles generated by electrolysis continuously accumulate on the concave surface due to buoyancy and cannot escape naturally. Therefore, a U-shaped pipe electroplating device is proposed.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A U-shaped pipe electroplating device includes a track frame, with multiple electroplating tanks arranged below the track frame. A moving unit is mounted on the track frame. The moving unit includes a transverse moving frame slidably mounted on the track frame. A vertical moving frame is mounted on the inner side of the transverse moving frame via a mounting bracket. A hanging unit is mounted at the bottom of the vertical moving frame. The hanging unit includes two placement frames fixed to the bottom of the vertical moving frame. A truss is connected to both placement frames. A T-shaped frame is installed at the bottom of the truss. The U-shaped pipe is hung horizontally or horizontally tilted upwards by a positioning component inserted into the inside of the T-shaped frame.

[0007] As a further description of the above technical solution: The positioning component includes a T-shaped base, on both sides of which extension rods are inserted through slots. A horizontal positioning slot is provided inside the extension rod, and a positioning block is inserted into the horizontal positioning slot. An inclined positioning slot adapted to the positioning block is provided on one side of the inner wall of the horizontal positioning slot.

[0008] As a further description of the above technical solution: A hollow column is inserted into the positioning block through a hole. An elastic sleeve is fitted on the outer wall of the hollow column through an annular groove, and the two ends of the elastic sleeve are fixed to the two side walls of the annular groove, respectively.

[0009] As a further description of the above technical solution: An arc-shaped block is inserted into the bottom wall of the annular groove through a through groove. A conical column with one end inserted into the hollow column is fixed in the middle of one side wall of the insertion hole. A wedge block with its bottom end fitting against the inclined section of the conical column is fixed at the bottom of the arc-shaped block.

[0010] As a further description of the above technical solution: The insertion hole has a fourth mounting hole on each of its two side walls, and a fourth spherical column is connected to the fourth mounting hole by a fourth spring. The hollow column has a plurality of fourth limiting holes corresponding to the fourth spherical column on its outer wall.

[0011] As a further description of the above technical solution: The inner side of the T-shaped frame is provided with a plurality of T-shaped limiting slots adapted to the T-shaped seat. The inner side of the T-shaped frame is also provided with a limiting slot adapted to the extension end of the T-shaped seat. The inner top wall and inner bottom wall of the T-shaped limiting slot and the limiting slot are provided with first mounting holes. A first spherical column is connected to the first mounting hole by a first spring. The outer surface of the extension end of the T-shaped seat is provided with four first limiting holes corresponding to the first spherical column.

[0012] As a further description of the above technical solution: The moving unit also includes four rollers rotatably connected within the transverse moving frame, wherein one end of each of the two rollers is fitted with a first shaft, and a dual-axis motor with its output end connected to the first shaft is fitted in the middle of the inner cavity of the transverse moving frame.

[0013] As a further description of the above technical solution: The top of the upright frame is rotatably connected to a second shaft, and a winding wheel is fixedly sleeved on the second shaft. A pull belt is wound around the winding wheel. A guide wheel is mounted on one side of the top of the upright frame. One end of the pull belt is connected to the vertical moving frame after passing through the guide wheel. A reduction motor with its output end connected to one end of the second shaft is installed on the outer wall of the upright frame.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The U-shaped tube can be hung horizontally or at an angle by the set hanging unit. The two working postures of horizontal hanging and angled hanging can be quickly switched by the insertion and removal of the positioning block and the horizontal positioning slot and the angled positioning slot. In a horizontal orientation, the straight section of the U-shaped tube is horizontal, the elbow extends outward, and the concave surface of the elbow faces vertically. This completely eliminates the inverted gas-collecting structure of the traditional inverted U-shaped vertical suspension. The hydrogen bubbles generated by electrolysis can float and escape directly under the action of buoyancy, fundamentally solving the industry pain point of concentrated and high incidence of pinholes and pitting defects on the concave surface of the elbow. At the same time, the entire tube is on the same horizontal plane, eliminating the difference in chemical concentration gradient and current edge effect between the upper and lower ends that naturally exist in vertical hanging. The pretreatment effect and coating adhesion of the curved section and the straight section are significantly improved. In the inclined position, the U-shaped tube is in an upward-curving state with the outside higher than the inside. The bubbles precipitated on the tube wall can escape along the slope towards the highest point of the bend, further reducing the degree of defects of the pinhole band on the straight tube. Moreover, when exiting the tank, the plating solution flows back along the inclined tube wall to the lower pipe opening, and the drainage is more thorough, which can significantly reduce the loss of plating solution and the risk of cross-contamination of the tank solution. The two positions can be flexibly selected according to the characteristics of the plating type and the surface condition of the tube, so as to achieve the optimal balance between venting effect, coating uniformity and material cost. Meanwhile, the device can simultaneously accommodate two completely different types of workpieces: straight pipes and U-shaped pipes. By inserting the T-shaped seat into the T-shaped limiting slot of the T-shaped frame at different angles, the straight pipe clamping mode and the U-shaped pipe clamping mode can be quickly switched without changing the main body of the fixture. With the extension rod's telescopic adjustment, the distance between the two positioning ends can be adjusted to accommodate U-shaped pipes of different lengths and bending radii. With the hollow column's internal expansion adjustment, it can accommodate pipes of different diameters. A single fixture can cover the clamping needs of multiple specifications of workpieces. Attached Figure Description

[0015] Figure 1 A schematic diagram of the overall structure provided according to an embodiment of the present invention is shown; Figure 2 A schematic diagram of a horizontally inserted positioning block provided according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of the tilted insertion of a positioning block according to an embodiment of the present invention is shown; Figure 4 A schematic diagram of the hollow column section provided according to an embodiment of the present invention is shown; Figure 5 A schematic diagram of the structure of a T-shaped frame provided according to an embodiment of the present invention is shown; Figure 6A cross-sectional structural diagram of the T-shaped frame provided according to an embodiment of the present invention is shown; Figure 7 A schematic diagram of a first perspective of a mobile unit provided according to an embodiment of the present invention is shown; Figure 8 A schematic diagram of a second perspective of a mobile unit provided according to an embodiment of the present invention is shown; Figure 9 A schematic diagram of a U-shaped pipe being horizontally suspended according to an embodiment of the present invention is shown; Figure 10 A schematic diagram of a U-shaped pipe being hung at an angle according to an embodiment of the present invention is shown; Figure 11 A schematic diagram of a first hanging state of a straight pipe according to an embodiment of the present invention is shown; Figure 12 A schematic diagram of a second hanging state of a straight pipe provided according to an embodiment of the present invention is shown; Figure 13 A schematic diagram of the U-shaped pipe being hung in the vertical position according to an embodiment of the present invention is shown; Figure 14 A schematic diagram of the hanging of a short straight pipe according to an embodiment of the present invention is shown.

[0016] Legend: 10. Track frame; 11. Electroplating tank; 20. Moving unit; 21. Lateral moving frame; 22. Upright frame; 23. Vertical moving frame; 24. Dual-axis motor; 25. Pull belt; 26. Gear motor; 30. Hanging unit; 31. Placement rack; 32. Truss; 33. T-shaped frame; 34. Positioning component; 341. T-shaped seat; 342. Extension rod; 343. Positioning insert; 344. Hollow column; 345. Elastic sleeve; 346. Arc block; 347. Conical column. Detailed Implementation

[0017] 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 embodiments of the present invention, and not all embodiments. 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.

[0018] like Figure 1 - Figure 14 As shown, the present invention provides: A U-shaped pipe electroplating device includes a track frame 10, with multiple electroplating tanks 11 arranged below the track frame 10. A moving unit 20 is mounted on the track frame 10. The moving unit 20 includes a transverse moving frame 21 slidably mounted on the track frame 10. A vertical moving frame 23 is mounted on the inner side of the transverse moving frame 21 via a mounting bracket 22. A hanging unit 30 is mounted at the bottom of the vertical moving frame 23. In particular, the electroplating device is also equipped with an electrode system and a plating solution circulation system. The electrode system and the plating solution circulation system are conventional structures known in the art. The hanging unit 30 can work normally by being connected to the cathode circuit as a whole. Its specific configuration will not be described in detail here.

[0019] The moving unit 20 also includes four rollers rotatably connected to the transverse moving frame 21. Two of the rollers are equipped with a first shaft at one end. A dual-axis motor 24 with its output end connected to the first shaft is installed in the middle of the inner cavity of the transverse moving frame 21. Specifically, in actual use, by starting the dual-axis motor 24, the first shaft is driven to rotate actively, thereby moving the transverse moving frame 21 along the track frame 10, which in turn drives the hanging unit 30 to move laterally. A second shaft is rotatably connected to the top of the upright frame 22. A winding wheel is fixedly sleeved on the second shaft, and a pull belt 25 is wound on the winding wheel. A guide wheel is installed on one side of the top of the upright frame 22. One end of the pull belt 25 is connected to the vertical moving frame 23 after passing through the guide wheel. A reduction motor 26 with its output end connected to one end of the second shaft is installed on the outer wall of the upright frame 22.

[0020] Specifically, after the hanging unit 30 moves above the electroplating tank 11, the geared motor 26 is started to control the take-up wheel to rotate counterclockwise, thereby unwinding the pull belt 25. This causes the vertical moving frame 23 to gradually move the hanging unit 30 downward, so that the pipe on the hanging unit 30 is submerged in the electroplating tank 11 or other tank. After the operation is completed, the geared motor 26 is used to control the take-up wheel to rotate clockwise, thereby winding the pull belt 25. This causes the vertical moving frame 23 to gradually move the hanging unit 30 upward, so that the pipe leaves the electroplating tank 11 or other tank.

[0021] like Figure 1 - Figure 11As shown, the hanging unit 30 includes two placement frames 31 fixed to the bottom of the vertical moving frame 23. A truss 32 is connected to both placement frames 31. A T-shaped frame 33 is installed at the bottom of the truss 32. Multiple positioning screw holes are provided on the upper surface of the truss 32 in a linear array. The top of the T-shaped frame 33 is provided with an assembly screw hole that matches the positioning screw hole. The positioning screw hole and the assembly screw hole are connected to a positioning bolt by a common thread. The T-shaped frame 33 is fixed to the bottom of the truss 32 by the positioning bolt. At the same time, by placing the T-shaped frame 33 in different positions, the spacing between the two T-shaped frames 33 can be adjusted. The U-shaped pipe can be hung horizontally or horizontally tilted upwards by the positioning member 34 inserted into the inside of the T-shaped frame 33.

[0022] The positioning component 34 includes a T-shaped base 341. Extension rods 342 are inserted into both sides of the T-shaped base 341 via slots. Second mounting holes are provided at the top and bottom of the end of the extension rod 342 inserted into the slot. A second spherical column is connected to the second mounting hole via a second spring. Multiple second limiting holes, adapted to the second spherical column, are provided on the top and bottom walls of the slot. These second limiting holes are arranged in a linear array, corresponding to the movement path of the extension rod 342. A horizontal positioning slot is provided inside the extension rod 342, and a positioning block 343 is inserted into the horizontal positioning slot. A corresponding positioning block 343 is provided on one side of the inner wall of the horizontal positioning slot. The horizontal positioning slot has a matching inclined positioning slot. Both sides of the horizontal positioning slot have a third mounting hole. A third spherical column is connected to the third mounting hole through a third spring. Both sides of the outer wall of the positioning block 343 have a third limiting hole that matches the third spherical column. It should be noted that when the positioning block 343 is horizontally placed in the horizontal positioning slot, the third spherical column engages in the third limiting hole on the front side, thus fixing the position of the horizontal positioning block 343. When the positioning block 343 is tilted and placed in the inclined positioning slot, the third spherical column engages in the third limiting hole on the rear side, thus fixing the position of the tilted positioning block 343.

[0023] Hollow columns 344 are inserted into the positioning block 343 through insertion holes. Specifically, the spacing between two hollow columns 344 can be adjusted by extending the extension rod 342 outward to accommodate U-shaped pipes of different sizes. After adjustment, the extension rod 342 is locked in place by a second spring in conjunction with a second spherical column. An elastic sleeve 345 is fitted onto the outer wall of the hollow column 344 through an annular groove, and the two ends of the elastic sleeve 345 are fixed to the two side walls of the annular groove. An arc-shaped groove is inserted into the bottom wall of the annular groove through a through-hole. The block 346 has a conical column 347 fixed at the middle of one side wall of the insertion hole, which is inserted into the hollow column 344. The bottom of the arc block 346 is fixed with a wedge block whose bottom fits against the inclined section of the conical column 347. A fourth mounting hole is provided on both sides of the insertion hole, and a fourth spherical column is connected to the fourth mounting hole by a fourth spring. Multiple fourth limiting holes corresponding to the fourth spherical column are provided on the outer wall of the hollow column 344. The multiple fourth limiting holes are distributed in a linear array, corresponding to the movement path of the hollow column 344.

[0024] Specifically, before placing the U-shaped pipe to be electroplated, first insert the T-shaped seat 341 horizontally into the T-shaped limiting slot, and then place the T-shaped seat 341 into the limiting slot as well. Then, by pulling the hollow column 344 outwards, it can move outwards. During this process, the wedge block is pushed outwards by the conical column 347, simultaneously driving the arc-shaped block 346 outwards. Gradually, it pushes against the elastic sleeve 345, causing it to expand, thus matching the inner diameter of the pipe. At this point, the positioning block 343, along with the hollow column 344, is inserted into the horizontal positioning slot for fixation. In this state, the U-shaped pipe, placed on two pairs of hollow columns 344, is in a horizontal position, i.e., the U-shaped bend is hung horizontally. In this state, the U-shaped pipe is in the posture of "straight pipe section axis horizontal, U-shaped plane vertical, bend extending towards the hanging bracket side," as shown. Figure 9 As shown, the concave surface of the elbow is vertically facing inward, which does not obstruct the vertical upward movement of air bubbles. During electroplating, all precipitated air bubbles are buoyed upwards and detach directly from the pipe wall, rising to the liquid surface without accumulating on the concave surface. Furthermore, there are no low-lying areas where liquid can pool in the entire pipe; the plating solution naturally drips along the pipe opening and wall upon exiting the tank, reducing plating solution loss and avoiding cross-contamination and waste. Simultaneously, because the entire pipe is on the same horizontal plane, there is no issue of concentration differences or uneven activation levels at the upper and lower ends of vertically hung sections. Pre-treatment degreasing and activation are more uniform, and the consistency of plating adhesion between the curved and straight sections is significantly improved. Notably, this configuration can also be used for hanging straight pipes, such as... Figure 11 As shown; Simultaneously, the positioning block 343, along with the hollow column 344, can be inserted into the inclined positioning slot for fixation. In this state, the U-shaped pipe, placed on the two hollow columns 344, is tilted upwards, i.e., the U-bend is hung tilted upwards, making the U-shaped pipe have an "outer higher than inner lower" tilted posture. Figure 10As shown, the bubbles precipitated on the inclined pipe wall, in addition to the vertical buoyancy, also gain a component force that slides along the pipe wall towards the upper end, and eventually all converge at the highest point of the bend to escape, greatly shortening the adhesion time of the bubbles on the pipe wall, which can further reduce the defect rate of pinholes on the busbar of the straight pipe; and the top of the gap between the pipes after the inclination is no longer a horizontal straight line, and the bubbles will continue to slide upward along the inclined gap to be discharged, completely breaking the stagnant gas film at the top of the gap; and when exiting the tank, the plating solution flows along the inclined pipe wall towards the lower pipe opening, the draining solution is cleaner, and the loss of plating solution carried out is further reduced.

[0025] like Figure 5 , Figure 6 , Figure 12 , Figure 13 and Figure 14 As shown, the inner side of the T-shaped frame 33 is provided with multiple T-shaped limiting slots that are adapted to the T-shaped seat 341. In particular, the cross-section of the extended end of the T-shaped seat 341 is square. The inner side of the T-shaped frame 33 is also provided with limiting slots that are adapted to the extended end of the T-shaped seat 341. The inner top wall and inner bottom wall of the T-shaped limiting slot and the limiting slot are provided with first mounting holes. A first spherical column is connected to the first mounting hole by installing a first spring. The outer surface of the extended end of the T-shaped seat 341 is provided with four first spherical columns corresponding to the first spherical columns. A limiting hole is provided, with the first limiting holes arranged in a circular array, and two symmetrical first limiting holes forming a group. When the T-shaped seat 341 is inserted into the T-shaped limiting slot or the limiting slot, the first spherical column will engage with the first limiting hole, thereby fixing the position of the T-shaped seat 341. It should be noted that when the T-shaped seat 341 is vertically inserted into the T-shaped limiting slot, its exposed surface is flush with the T-shaped bracket 33. This state is used for hanging straight pipes, and in this state, the T-shaped seat 341 cannot be inserted into the limiting slot. Figure 12 As shown, in this state, it can also be used to place U-shaped pipes of fixed size, such as... Figure 13 As shown, after placement, the U-shaped pipe is in a horizontal-vertical state. In this state, the concave surface is prone to air trapping, and it cannot be used for U-shaped pipes of different sizes. It should also be noted that regardless of whether the T-shaped seat 341 is horizontal or tilted, its hollow column 344 can be used to hang short straight pipes, such as... Figure 14 As shown.

[0026] Specifically, this U-shaped pipe electroplating device operates / is used as follows: 1. Pre-adjustment of clamping parameters Based on the shape, specifications, and process requirements of the workpiece to be plated, the parameters of the hanging unit 30 are set in advance: Pipe length spacing adjustment: Loosen the positioning bolts on the truss 32, adjust the spacing of the T-shaped frame 33 along the positioning screw holes, and then tighten them again to complete the adaptation of large span pipe length; if fine adjustment is required, the extension rod 342 can be stretched outward or pushed inward, and the spherical limiting structure can be used to lock and position it to adapt to workpieces of different lengths.

[0027] Hanging posture selection: When the U-shaped tube needs to be hung horizontally, insert the positioning block 343 into the horizontal positioning slot of the extension rod 342, and lock it by engaging the front limiting hole through the spherical structure; when it needs to be hung at an angle to enhance the venting and drainage effect, insert the positioning block 343 into the angled positioning slot, and lock it by engaging the rear limiting hole through the spherical structure.

[0028] Pipe diameter adaptation: Pull the hollow column 344 outward, and the inclined surface of the conical column 347 will simultaneously push the wedge block and the arc block 346 outward, opening the elastic sleeve 345 to a size that matches the inner diameter of the pipe to be plated. The spherical limiting structure will then lock into the corresponding limiting hole to achieve pipe diameter self-adaptation.

[0029] Workpiece form switching: When a straight tube needs to be clamped, insert the T-shaped seat 341 vertically into the T-shaped limiting slot of the T-shaped frame 33, and lock it by the first spherical column to switch to the straight tube clamping mode; when a U-shaped tube needs to be clamped, insert the T-shaped seat 341 horizontally into the corresponding slot and lock it.

[0030] 2. Workpiece clamping Align the end of the tube to be plated with the hollow column 344 and push it in smoothly. The radial tension of the elastic sleeve 345 is used to achieve axial positioning and conductive contact of the tube. The workpiece clamping of all stations is completed in sequence to achieve batch plating.

[0031] 3. Full-process flow operation After clamping, the dual-axis motor 24 drives the transverse moving frame 21 to move laterally along the track frame 10, moving the hanging unit 30 to directly above the corresponding electroplating tank 11. Subsequently, the reduction motor 26 drives the winding wheel to rotate and release the pull belt 25. The vertical moving frame 23 drives the hanging unit 30 to descend smoothly, so that the pipe to be plated is completely immersed in the plating solution to carry out the electroplating operation. After a single process is completed, the reduction motor 26 rotates in the opposite direction to wind up the pull belt 25, driving the workpiece to rise out of the tank, and then the transverse moving frame 21 transfers it to the next process tank, completing the entire process of surface treatment, including degreasing, activation, electroplating, water washing, and passivation.

[0032] 4. Production Change and Maintenance When changing the specifications or shape of a workpiece, simply pull out the corresponding adjustment component, adjust the parameters, and then reinsert and lock it to complete the changeover. No special tools are required. Routine maintenance only requires periodically cleaning the plating residue on the surface of the positioning component 34.

[0033] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A U-shaped pipe electroplating device, comprising a track frame (10), wherein a plurality of electroplating tanks (11) are arranged below the track frame (10), and a moving unit (20) is mounted on the track frame (10), wherein the moving unit (20) includes a transverse moving frame (21) slidably mounted on the track frame (10), and a vertical moving frame (23) is mounted on the inner side of the transverse moving frame (21) via a mounting bracket (22), characterized in that, The bottom of the vertical moving frame (23) is equipped with a hanging unit (30); The hanging unit (30) includes two placement racks (31) fixed to the bottom of the vertical moving frame (23). A truss (32) is connected to both placement racks (31). A T-shaped frame (33) is installed at the bottom of the truss (32). The U-shaped pipe is horizontally hung or horizontally tilted upwards by a positioning piece (34) inserted into the inside of the T-shaped frame (33).

2. The U-shaped pipe electroplating device according to claim 1, characterized in that, The positioning component (34) includes a T-shaped seat (341), on both sides of the T-shaped seat (341) an extension rod (342) is inserted through a slot. A horizontal positioning slot is provided in the extension rod (342), and a positioning block (343) is inserted in the horizontal positioning slot. An inclined positioning slot adapted to the positioning block (343) is provided on one side of the inner wall of the horizontal positioning slot.

3. The U-shaped pipe electroplating device according to claim 2, characterized in that, A hollow column (344) is inserted into the positioning block (343) through an insertion hole. An elastic sleeve (345) is fitted on the outer wall of the hollow column (344) through an annular groove, and the two ends of the elastic sleeve (345) are respectively fixed to the two side walls of the annular groove.

4. The U-shaped pipe electroplating device according to claim 3, characterized in that, An arc-shaped block (346) is inserted into the bottom wall of the annular groove through a through groove. A conical column (347) with one end inserted into the hollow column (344) is fixed in the middle of one side wall of the insertion hole. A wedge block with its bottom end fitting against the inclined section of the conical column (347) is fixed at the bottom of the arc-shaped block (346).

5. The U-shaped pipe electroplating device according to claim 4, characterized in that, The two side walls of the insertion hole are provided with a fourth mounting hole, and a fourth spherical column is connected in the fourth mounting hole by a fourth spring. The outer wall of the hollow column (344) is provided with a plurality of fourth limiting holes corresponding to the fourth spherical column.

6. The U-shaped pipe electroplating device according to claim 5, characterized in that, The inner side of the T-shaped frame (33) is provided with a plurality of T-shaped limiting slots that are adapted to the T-shaped seat (341). The inner side of the T-shaped frame (33) is also provided with a limiting slot that is adapted to the extension end of the T-shaped seat (341). The inner top wall and inner bottom wall of the T-shaped limiting slot and the limiting slot are provided with first mounting holes, and a first spherical column is connected in the first mounting hole by installing a first spring. The outer surface of the extension end of the T-shaped seat (341) is provided with four first limiting holes corresponding to the first spherical column.

7. The U-shaped pipe electroplating device according to claim 2, characterized in that, The moving unit (20) also includes four rollers rotatably connected to the transverse moving frame (21), wherein one end of each of the two rollers is equipped with a first shaft, and a dual-axis motor (24) with its output end connected to the first shaft is installed in the middle of the inner cavity of the transverse moving frame (21).

8. The U-shaped pipe electroplating device according to claim 7, characterized in that, The top of the support frame (22) is rotatably connected to a second shaft, and a winding wheel is fixedly sleeved on the second shaft. A pull belt (25) is wound on the winding wheel. A guide wheel is mounted on one side of the top of the support frame (22). One end of the pull belt (25) is connected to the vertical moving frame (23) after passing through the guide wheel. A reduction motor (26) with its output end connected to one end of the second shaft is installed on the outer wall of the support frame (22).

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