Flexible thin-walled elbow inner wall chemical mechanical polishing equipment and method

Abstract

The present application provides a kind of flexible thin-walled elbow inner wall chemical mechanical polishing equipment and method, including executive part and drive box.The executive part includes universal joint, fine polishing wheel, rough polishing wheel and retainer, and the executive part is used to extend into the inner wall of pipe for polishing.The drive box includes control system, spindle, spindle motor, polishing liquid output system and spindle motor moving device for adjusting the stroke of spindle, and is used to provide polishing power, store and pump chemical mechanical polishing liquid, and set polishing parameters.The executive part is flexibly connected through universal joint, conforms to the curve of elbow, and avoids over-polishing at bending place.The polishing axis is coincided with the axis of elbow by setting retainer, to ensure the uniformity and consistency of polishing, and avoid the damage of thin-walled pipe.The rough polishing wheel and fine polishing wheel are driven to rotate and reciprocate in pipe by the linkage of spindle motor and screw motor, and the quality of inner wall of pipe after polishing is greatly improved by the action of chemical mechanical polishing liquid.

Description

Technical Field

[0001] This invention relates to the field of machining equipment technology, and in particular to a chemical mechanical polishing equipment and method for the inner wall of a flexible thin-walled bent pipe. Background Technology

[0002] 3D printing additive manufacturing of thin-walled bent pipe parts offers advantages such as customizable shapes, thin walls, light weight, and high rigidity, making it widely used in the aerospace field. However, due to the special forming process, 3D printed parts often have poor surface quality, with a surface roughness typically around Ra 10μm, while thin-walled bent pipe parts used in the aerospace field require a surface roughness Ra ≤ 0.8μm. Existing methods for polishing the inner walls of pipes mainly include abrasive flow polishing, mechanical honing, and manual polishing. Abrasive flow polishing is prone to "over-polishing" and "beveling" at the inlet and outlet, severely affecting the shape and position accuracy of the pipe. Furthermore, abrasive flow polishing requires significant pressure, which can easily deform and break thin-walled pipes. Mechanical honing typically uses rigid tools inserted into the pipe for polishing; for pipes with a large length-to-diameter ratio, rigid tools are prone to chattering inside the pipe and are unsuitable for polishing bent pipes. Manual polishing results in poor surface consistency, high labor intensity, low efficiency, and inconsistent quality, and can easily lead to occupational diseases due to dust inhalation by operators. Furthermore, the aforementioned traditional polishing methods that use stress to remove materials result in a thick residual damage layer after polishing, which does not reach the level of chemical mechanical polishing.

[0003] The chemical mechanical polishing (CMP) process can be simply summarized as follows: a CMP slurry comes into contact with the workpiece surface, where its chemical components cause a thin, softening film to form on the surface. This softening film is then removed by the mechanical action of abrasives and polishing pads. Surface planarization is achieved through this alternating process of chemical film formation and mechanical film removal. However, CMP is typically used for polishing planar parts and is currently the most effective method for achieving global planarization; it is difficult to achieve in polishing thin-walled, bent pipes. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a chemical mechanical polishing (CMP) device and method for the inner wall of flexible thin-walled bent tubes. This method achieves a surface roughness Ra ≤ 0.8 μm on the inner wall of the polished thin-walled bent tube parts, solving the problem of high surface roughness in existing 3D printed additive manufacturing of thin-walled bent tube parts, which hinders their application in the aerospace field. The technical means employed in this invention are as follows:

[0005] A chemical mechanical polishing (CMP) device for the inner wall of a flexible thin-walled bent pipe includes an actuator and a drive unit. The actuator comprises a universal joint, a fine polishing wheel, a coarse polishing wheel, and a retainer assembled together. At least one fine polishing wheel and one coarse polishing wheel are present. The retainers are located on both sides of the fine and coarse polishing wheels, and are connected by the universal joint. The actuator is used to extend into the inner wall of the pipe for polishing. The universal joint and retainers work together to ensure the actuator's operation within the bent pipe. The drive unit includes a control system, a spindle, a spindle motor, a polishing fluid output system, and a spindle motor moving device for adjusting the spindle stroke. The drive unit provides polishing power, stores and pumps CMP fluid, and sets polishing parameters. The output end of the spindle motor is connected to the spindle, the spindle is connected to the input end of the actuator, and the spindle motor is connected to the spindle motor moving device. The polishing state of the actuator on the inner wall of the pipe is adjusted through the combined action of the spindle, the spindle motor, and the spindle motor moving device. The polishing fluid output system supplies CMP fluid to the inside of the pipe to be polished.

[0006] Furthermore, the drive box is provided with a component storage position and an overall storage position. The component storage position is used to store universal joints, fine polishing wheels, coarse polishing wheels, and cages of different specifications separately for individual replacement after wear and tear. The overall storage position is used to store the assembled universal joints, fine polishing wheels, coarse polishing wheels, and cages to form the actuator for overall access.

[0007] Furthermore, the retainer is used to ensure that the processing axis coincides with the pipe axis, ensuring the operation of the actuator in the bend, preventing jamming at the bend, and preventing the polishing wheel from becoming eccentric at the bend and causing over-polishing.

[0008] Furthermore, the universal joint is used to connect the fine polishing wheel, the coarse polishing wheel, and the cage, and transmits the power provided by the drive box to the fine polishing wheel and the coarse polishing wheel, while also serving as a transition point for the polishing wheel at the bend.

[0009] Furthermore, the coarse polishing wheel is used for coarse polishing to quickly reduce roughness and improve polishing efficiency. The coarse polishing wheel includes linen wheel, wool wheel, fiber wheel, and polyurethane wheel.

[0010] Furthermore, the fine polishing wheel is used for fine polishing to ensure polishing quality and reduce residual damage layers. Fine polishing wheels include linen wheels, wool wheels, fiber wheels, and polyurethane wheels. Fine polishing wheels need to have a finer texture than coarse polishing wheels to meet the requirements of fine polishing. During polishing, the synergistic mechanical action of the coarse and fine polishing wheels, along with the abrasive particles in the chemical mechanical polishing slurry, removes the softened layer on the workpiece surface caused by the chemical components in the slurry. This process is repeated until precise polishing of the inner wall is achieved.

[0011] Furthermore, the control system is used to integrate and control the spindle motor speed, polishing fluid pump speed, and lead screw motor speed.

[0012] Furthermore, the polishing slurry output system includes a polishing slurry tank, a polishing slurry pump, and a polishing slurry outlet. The polishing slurry tank is used to hold chemical mechanical polishing slurry, and the polishing slurry pump is used to pump the chemical mechanical polishing slurry in the polishing slurry tank to the polishing slurry outlet.

[0013] Furthermore, the spindle motor provides power to the spindle, which is the power output end of the drive box and is used to connect to the actuator. When the spindle motor rotates, it drives the actuator to rotate within the pipe. The spindle motor moving device includes a movable bracket, a lead screw, a guide rail, and a lead screw motor. The guide rail is installed at the bottom of the back of the component storage position. The movable bracket is installed on the guide rail and can slide along the guide rail. The spindle motor is installed on the movable bracket. The lead screw motor is installed at the other end of the bottom of the back of the component storage position and is used to provide power to the lead screw. When the lead screw rotates, it can drive the movable bracket to translate along the guide rail, thereby driving the spindle motor and the spindle to translate, and thus driving the actuator to translate within the pipe.

[0014] Furthermore, a support is provided at the bottom of the drive box to provide support for the drive box.

[0015] This invention also discloses a chemical mechanical polishing method for the inner wall of a flexible thin-walled bent pipe based on the above-mentioned chemical mechanical polishing device, comprising the following steps:

[0016] Step 1: Remove the cage, universal joint, coarse polishing wheel, and fine polishing wheel from the drive box. Connect them in the following order to form the actuator: cage, universal joint, coarse polishing wheel, universal joint, cage, universal joint, fine polishing wheel, universal joint, cage. During connection, cages must be installed on both sides of the coarse and fine polishing wheels to ensure that the polishing axis coincides with the pipe bend axis. The number of polishing wheels can be increased according to the pipe length. Alternatively, coarse or fine polishing wheels can be repeatedly connected in series as needed, or all coarse polishing wheels can be connected in series first, followed by fine polishing wheels for precision polishing.

[0017] Step 2: Insert the assembled actuator into the bent workpiece, and connect the end of the actuator to the spindle of the drive box via a universal joint or flexible shaft. Add chemical mechanical polishing slurry to the polishing slurry tank. Secure the workpiece to prevent vibration from affecting the polishing effect.

[0018] Step 3: Prepare a plastic tube. Connect one end to the polishing fluid outlet of the drive box and place the other end at the workpiece opening with the actuator so that the chemical mechanical polishing fluid can be introduced into the workpiece.

[0019] Step 4: Turn on the polishing fluid pump, spindle motor, and lead screw motor. Adjust the operating parameters according to the actual situation through the control system. While rotating, each polishing wheel in the actuator reciprocates within the pipeline driven by the lead screw motor.

[0020] Step 5: After polishing is complete, turn off the polishing fluid pump, turn off the spindle motor, turn off the lead screw motor, pull out the actuator, and put it into the component storage compartment or the overall storage compartment in the drive box as needed.

[0021] The present invention has the following advantages:

[0022] 1. This invention provides a chemical mechanical polishing (CMP) device and method for the inner wall of a flexible thin-walled bent pipe. It utilizes the synergistic mechanical action of a coarse polishing wheel, a fine polishing wheel, and abrasive particles in the CMP slurry to remove the softened layer on the workpiece surface caused by the chemical components in the CMP slurry. This process is repeated to achieve precision polishing of the inner wall of the thin-walled bent pipe. This solves the problem that traditional polishing methods are difficult or impossible to use for polishing the inner wall of thin-walled bent pipes.

[0023] 2. This invention provides a chemical mechanical polishing (CMP) device and method for the inner wall of a flexible thin-walled bent pipe. It utilizes a universal joint for flexible connection, conforming to the curve of the bent pipe and avoiding over-polishing at the bend. A retainer ensures the polishing axis coincides with the bent pipe axis, guaranteeing uniformity and consistency in polishing and preventing damage to the thin-walled pipe. The combined effect of a spindle motor and a lead screw motor driving the coarse and fine polishing wheels to rotate and reciprocate within the pipe, along with the action of a CMP slurry, significantly improves the quality of the inner wall of the pipe after polishing.

[0024] 3. This invention provides a chemical mechanical polishing equipment and method for the inner wall of a flexible thin-walled bent pipe. By changing the polishing wheel of different diameter, it can be applied to polishing the inner wall of pipes of different diameters. It has strong versatility, and the polishing process does not generate dust or noise pollution. The entire polishing process is environmentally friendly and low in cost. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0026] Figure 1 This is a three-dimensional structural diagram of the execution unit of the device in a half-section pipe in an embodiment of the present invention.

[0027] Figure 2 This is a three-dimensional structural diagram of the drive box of the device in an embodiment of the present invention.

[0028] Figure 3This is a three-dimensional structural diagram of the drive box of the device in an embodiment of the present invention, viewed from the bottom.

[0029] Figure 4 This is a three-dimensional structural diagram of the cage in an embodiment of the present invention.

[0030] Figure 5 This is a photograph of the polished workpiece in an embodiment of the present invention.

[0031] Figure 6 Photograph 1 is an optical image of the inner wall of the workpiece before polishing in an embodiment of the present invention.

[0032] Figure 7 Photograph 2 shows the inner wall of the workpiece before polishing in this embodiment of the invention.

[0033] Figure 8 This is an optical photograph 1 of the polished inner wall of the workpiece in this embodiment of the invention.

[0034] Figure 9 This is an optical photograph 2 of the inner wall of the polished workpiece in an embodiment of the present invention.

[0035] Figure 10 Photograph 1 shows the surface roughness measurement of the inner wall of the polished workpiece in this embodiment of the invention.

[0036] Figure 11 Photo 2 shows the surface roughness measurement of the inner wall of the polished workpiece in this embodiment of the invention.

[0037] In the diagram: 1. Workpiece; 2. Universal joint; 3. Fine polishing wheel; 4. Coarse polishing wheel; 5. Cage; 5.1. Outer ring of cage; 5.2. Cage balls; 5.3. Inner ring of cage; 5.4. Cage mandrel; 6. Drive box; 6.1. Component storage area; 6.2. Overall storage area; 6.3. Control system; 6.4. Spindle; 6.5. Spindle motor; 6.6. Polishing slurry outlet; 6.7. Polishing slurry pump; 6.8. Polishing slurry tank; 6.9. Movable bracket; 6.10. Lead screw; 6.11. Guide rail; 6.12. Lead screw motor; 6.13. Support. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0039] like Figures 1-4As shown in the figure, this invention discloses a chemical mechanical polishing (CMP) device and method for the inner wall of a flexible thin-walled bent pipe. During the polishing process, the coarse polishing wheel 4, the fine polishing wheel 3, and the abrasive particles in the CMP slurry work together to remove the softened layer on the surface of the workpiece 1 caused by the chemical components in the CMP slurry. This process is repeated to achieve precision polishing of the inner wall of the thin-walled bent pipe. This solves the problem that traditional polishing methods are difficult or impossible to use for polishing the inner wall of thin-walled bent pipes.

[0040] A chemical mechanical polishing (CMP) device for the inner wall of a flexible thin-walled bent pipe includes an actuator and a drive housing 6. The actuator includes a universal joint 2, a fine polishing wheel 3, a coarse polishing wheel 4, and a retainer 5. The actuator is used to extend into the workpiece 1 to polish the inner wall. The drive housing 6 includes a component storage compartment 6.1, an overall storage compartment 6.2, a control system 6.3, a spindle 6.4, a spindle motor 6.5, a polishing slurry outlet 6.6, a polishing slurry pump 6.7, a polishing slurry tank 6.8, a movable support 6.9, a lead screw 6.10, a guide rail 6.11, a lead screw motor 6.12, and a support 6.13. The drive housing 6 provides polishing power, stores and pumps the CMP slurry, and sets polishing parameters.

[0041] Specifically, the cage 5 is a rolling sleeve structure with a mandrel, including an outer cage ring 5.1, cage balls 5.2, an inner cage ring 5.3, and a cage mandrel 5.4. The outer cage ring 5.1 is nested within the inner cage ring 5.3, forming a raceway between the inner and outer rings. The cage balls 5.2 are spaced apart within the raceway. The cage mandrel 5.4 is located at the center of the inner cage ring 5.3, and is coaxial with both the inner and outer cage rings 5.1. The cage 5 ensures that the processing axis coincides with the pipe axis, ensuring the operation of the actuator in the bend, preventing jamming at bends, and preventing the polishing wheel from becoming eccentric at bends, thus avoiding over-polishing.

[0042] Specifically, the universal joint 2 is a cross-shaped universal joint used to connect the fine polishing wheel 3, the coarse polishing wheel 4 and the cage 5, and to transmit the power provided by the drive box 6 to the fine polishing wheel 3 and the coarse polishing wheel 4, while also serving as a gradual transition of the polishing wheel at the bend.

[0043] Specifically, the coarse polishing wheel 4 is used for coarse polishing to quickly reduce roughness and improve polishing efficiency. The coarse polishing wheel 4 can be a linen wheel, wool wheel, fiber wheel, polyurethane wheel, etc.

[0044] Specifically, the fine polishing wheel 3 is used for fine polishing to ensure polishing quality and reduce residual damage layers. The fine polishing wheel 3 can also be a linen wheel, wool wheel, fiber wheel, polyurethane wheel, etc. The fine polishing wheel 3 needs to have a finer texture than the coarse polishing wheel 4 to meet the requirements of fine polishing. During polishing, the synergistic mechanical action of the coarse polishing wheel 4, the fine polishing wheel 3, and the abrasive particles in the chemical mechanical polishing slurry removes the softened layer on the workpiece surface caused by the chemical components in the slurry. This process is repeated until precise polishing of the inner wall is achieved.

[0045] Specifically, the component storage position 6.1 is used to separately store the universal joint 2, the fine polishing wheel 3, the coarse polishing wheel 4, and the retainer 5, so that they can be replaced individually after wear and tear.

[0046] Specifically, the overall storage position 6.2 is used to store the actuators, such as the universal joint 2, the fine polishing wheel 3, the coarse polishing wheel 4, and the cage 5, which are connected in series, so that they can be accessed as a whole.

[0047] Specifically, the control system 6.3 is used to integrate and control the speed of the spindle motor 6.5, the speed of the polishing liquid pump 6.7, and the speed of the lead screw motor 6.12.

[0048] Specifically, the spindle motor 6.5 provides power to the spindle 6.4, which is the power output end of the drive box 6 and is used to connect to the actuator. When the spindle motor 6.5 rotates, it drives the actuator to rotate inside the pipe.

[0049] Specifically, the polishing liquid tank 6.8 is installed at the bottom of the back of the overall storage position 6.2 and is used to hold the chemical mechanical polishing liquid. The polishing liquid pump 6.7 is used to pump the chemical mechanical polishing liquid in the polishing liquid tank 6.8 to the polishing liquid outlet 6.6.

[0050] Specifically, the guide rail 6.11 is installed at the bottom back of the component storage position 6.1; the movable bracket 6.9 is installed on the guide rail 6.11 and can slide along the guide rail 6.11; the main spindle motor 6.5 is installed on the movable bracket 6.9; the lead screw motor 6.12 is installed at the other end of the bottom back of the component storage position 6.1, providing power to the lead screw 6.10. When the lead screw 6.10 rotates, it can drive the movable bracket 6.9 to translate along the guide rail 6.11, thereby driving the main spindle motor 6.5 and the main spindle 6.4 to translate, thereby driving the actuator to translate within the pipe.

[0051] Specifically, the support 6.13 provides support for the drive box 6.

[0052] In this embodiment, the workpiece 1 used for polishing is as follows: Figure 5 As shown, it is a 3D-printed thin-walled bent tube with a wall thickness of 1mm, a diameter of 5cm, and a length of 45cm. Before polishing, the surface roughness of the inner wall of the bent tube is approximately Ra 10μm. The surface quality of the inner wall of the bent tube before polishing is as follows: Figure 6 ,7 As shown, the surface quality is poor, with a large amount of semi-molten powder and sintering nodules adhering to the surface. After polishing using this embodiment, the surface quality of the inner wall of the bent pipe is as follows: Figure 8 , 9 As shown, the surface is smooth, glossy, and semi-mirror-like, without any semi-molten powder or sintering nodules. The surface roughness of the inner wall of the polished bend is Ra 0.488–0.533 μm, which is lower than the required Ra of 0.8 μm. The roughness measurement results are as follows: Figure 10 , 11 As shown. Therefore, this embodiment has an excellent effect on polishing the inner wall of 3D printed thin-walled bent tubes.

[0053] A chemical mechanical polishing device and method for the inner wall of a flexible thin-walled bent pipe includes the following steps:

[0054] Step 1: Remove the cage 5, universal joint 2, coarse polishing wheel 4, and fine polishing wheel 3 from the drive box 6. Connect them sequentially in the following order: cage 5, universal joint 2, coarse polishing wheel 4, universal joint 2, cage 5, universal joint 2, fine polishing wheel 3, universal joint 2, cage 5. During connection, cages 5 must be installed on both sides of the coarse polishing wheel 4 and fine polishing wheel 3 to ensure that the polishing axis coincides with the bend axis. The number of polishing wheels can be increased according to the pipe length. Alternatively, coarse polishing wheels 4 or fine polishing wheels 3 can be repeatedly connected in series as needed, or all coarse polishing wheels 4 can be connected in series first, followed by fine polishing wheels 3 for precision polishing.

[0055] Step 2: Insert the completed actuator into the bent tube workpiece 1, and connect the end of the actuator to the main shaft 6.4 of the drive box 6 via a universal joint 2 or a flexible shaft. Add chemical mechanical polishing slurry to the polishing slurry tank 6.8. Fix workpiece 1 to prevent vibration from affecting the polishing effect.

[0056] Step 3: Prepare a plastic tube. Connect one end to the polishing fluid outlet 6.6 of the drive box 6, and place the other end at the workpiece 1 with the actuator, so that the chemical mechanical polishing fluid can be introduced into the workpiece 1.

[0057] Step 4: Turn on the polishing liquid pump 6.7, the spindle motor 6.5, and the lead screw motor 6.12. Adjust the operating parameters according to the actual situation through the control system 6.3. While rotating, each polishing wheel in the actuator reciprocates within the pipeline driven by the lead screw motor 6.12.

[0058] Step 5: After polishing is completed, turn off the polishing fluid pump 6.7, turn off the spindle motor 6.5, turn off the lead screw motor 6.12, pull out the actuator, and put it into the component storage position 6.1 or the overall storage position 6.2 in the drive box 6 as needed.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention 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 the embodiments of the present invention.

Claims

1. A chemical mechanical polishing (CMP) device for the inner wall of a flexible thin-walled bent pipe, comprising an actuator and a drive unit. The actuator includes a universal joint, a fine polishing wheel, a coarse polishing wheel, and a retainer assembled together, wherein at least one fine polishing wheel and one coarse polishing wheel are present, and the retainers are provided on both sides of the coarse and fine polishing wheels. The fine polishing wheel, the coarse polishing wheel, and the retainers are connected by a universal joint. The actuator is used to extend into the inner wall of the pipe for polishing. The operation of the actuator inside the bent pipe is ensured by the combined action of the universal joint and the retainer. The drive unit includes a control system, a spindle, and a control system. The system includes a spindle motor, a polishing slurry output system, and a spindle motor moving device for adjusting the spindle stroke. The drive box provides polishing power, stores and pumps chemical mechanical polishing slurry, and sets polishing parameters. The output end of the spindle motor is connected to the spindle, the spindle is connected to the input end of the actuator, and the spindle motor is connected to the spindle motor moving device. The polishing state of the actuator on the inner wall of the pipe is adjusted by the combined action of the spindle, the spindle motor, and the spindle motor moving device. The polishing slurry output system supplies chemical mechanical polishing slurry to the inside of the pipe to be polished. The cage is used to ensure that the processing axis coincides with the pipeline axis, ensuring the operation of the actuator in the bend, preventing jamming at the bend, and preventing the polishing wheel from becoming eccentric at the bend and causing over-polishing. Specifically, the cage is a roller sleeve structure with a mandrel, including an outer cage ring, cage balls, an inner cage ring, and a cage mandrel. The outer cage ring is nested in the inner cage ring, forming a raceway between the inner and outer rings. The cage balls are installed at intervals in the raceway. The cage mandrel is located at the center of the inner cage ring, and it is coaxial with the inner and outer cage rings. The polishing slurry output system includes a polishing slurry tank, a polishing slurry pump, and a polishing slurry outlet. The polishing slurry tank is used to hold chemical mechanical polishing slurry, and the polishing slurry pump is used to pump the chemical mechanical polishing slurry in the polishing slurry tank to the polishing slurry outlet. During polishing, the synergistic mechanical action of the coarse polishing wheel, the fine polishing wheel, and the abrasive particles in the chemical mechanical polishing slurry removes the softened layer on the workpiece surface caused by the chemical components in the slurry. This process is repeated to achieve precision polishing of the inner wall. The flexible connection using universal joints conforms to the curve of the pipe bend, avoiding excessive flaring at the bend.

2. The chemical mechanical polishing equipment for the inner wall of a flexible thin-walled bent pipe according to claim 1, wherein the drive box is provided with a component storage position and an overall storage position, wherein the component storage position is used to separately store the universal joint, the fine polishing wheel, the coarse polishing wheel, and the cage for individual replacement after wear; wherein the overall storage position is used to store the actuator formed by the assembled universal joint, the fine polishing wheel, the coarse polishing wheel, and the cage for overall access.

3. The chemical mechanical polishing equipment for the inner wall of a flexible thin-walled bent pipe according to claim 1, characterized in that, The universal joint is used to connect the fine polishing wheel, the coarse polishing wheel and the cage, and transmits the power provided by the drive box to the fine polishing wheel and the coarse polishing wheel. It also serves as a transition point for the polishing wheel at the bend.

4. The chemical mechanical polishing equipment for the inner wall of a flexible thin-walled bent pipe according to claim 1, characterized in that, The coarse polishing wheel is used for coarse polishing to quickly reduce roughness and improve polishing efficiency. The coarse polishing wheel includes linen wheel, wool wheel, fiber wheel, and polyurethane wheel. The fine polishing wheel is used for fine polishing to ensure polishing quality and reduce residual damage layer. The fine polishing wheel includes linen wheel, wool wheel, fiber wheel, and polyurethane wheel. The fine polishing wheel needs to have a finer texture than the coarse polishing wheel to meet the needs of fine polishing.

5. The chemical mechanical polishing equipment for the inner wall of a flexible thin-walled bent pipe according to claim 1, characterized in that, The control system is used to integrate and control the spindle motor speed, polishing fluid pump speed, and lead screw motor speed.

6. The chemical mechanical polishing equipment for the inner wall of a flexible thin-walled bent pipe according to claim 1, characterized in that, The main spindle motor provides power to the main spindle, which is the power output end of the drive box and is used to connect to the actuator. When the main spindle motor rotates, it drives the actuator to rotate within the pipe. The main spindle motor moving device includes a movable bracket, a lead screw, a guide rail, and a lead screw motor. The guide rail is installed at the bottom back of the component storage position. The movable bracket is installed on the guide rail and can slide along the guide rail. The main spindle motor is installed on the movable bracket. The lead screw motor is installed at the other end of the bottom back of the component storage position and provides power to the lead screw. When the lead screw rotates, it can drive the movable bracket to translate along the guide rail, thereby driving the main spindle motor and the main spindle to translate, and thus driving the actuator to translate within the pipe.

7. The chemical mechanical polishing equipment for the inner wall of a flexible thin-walled bent pipe according to claim 1, characterized in that, The bottom of the drive box is provided with a support, which provides support for the drive box.

8. A method for chemical mechanical polishing of the inner wall of a flexible thin-walled bent pipe using the chemical mechanical polishing equipment described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: Take out the cage, universal joint, coarse polishing wheel and fine polishing wheel from the drive box, and connect them in the following order to form the actuator: cage, universal joint, coarse polishing wheel, universal joint, cage, universal joint, fine polishing wheel, universal joint and cage. When connecting, cages must be installed on both sides of the coarse polishing wheel and the fine polishing wheel to ensure that the polishing axis coincides with the axis of the bend. When connecting, increase the number of polishing wheels according to the length of the pipe. Repeat the series connection of coarse polishing wheels or fine polishing wheels as needed, or connect all the coarse polishing wheels in series first, and then connect all the fine polishing wheels in series for precision polishing after the coarse polishing is completed. Step 2: Insert the completed actuator into the bent tube workpiece, connect the end of the actuator to the main shaft of the drive box via a universal joint or flexible shaft, add chemical mechanical polishing fluid to the polishing fluid tank; fix the workpiece to prevent vibration from affecting the polishing effect; Step 3: Prepare a plastic tube. Connect one end to the polishing fluid outlet of the drive box and place the other end at the workpiece opening with the actuator so that the chemical mechanical polishing fluid can be introduced into the workpiece. Step 4: Turn on the polishing liquid pump, turn on the spindle motor, turn on the lead screw motor. The operating parameters are adjusted according to the actual situation through the control system. While the polishing wheels in the actuator are rotating, they reciprocate in the pipeline under the drive of the lead screw motor. Step 5: After polishing is complete, turn off the polishing fluid pump, turn off the spindle motor, turn off the lead screw motor, pull out the actuator, and put it into the component storage compartment or the overall storage compartment in the drive box as needed.

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