A rope polishing method for the surface of a narrow bore of a part

Abstract

The application discloses a rope polishing method for a narrow inner hole surface of a part, which comprises the following steps: S1, obtaining a part to be polished; S2, obtaining the size of the surface / hole to be polished and other information of the part to be polished, making a polishing rope, setting polishing machine parameters and selecting a polishing liquid; S3, installing the polishing rope, fixing the part to be polished and writing a polishing control program; S4, the polishing machine polishes according to the control program; and S5, checking whether the polishing reaches the expected effect, and if yes, ending the polishing, otherwise, re-polishing. The rope polishing method for the narrow inner hole surface of the part is characterized in that a polishing rope wound with polishing material is passed through the narrow inner hole, and the inner wall of the workpiece is ground and polished by high-speed rotation of the polishing rope, and meanwhile, the workpiece moves, so that the narrow inner hole surface of the workpiece is conformally polished.

Description

Technical Field

[0001] This invention belongs to the field of polishing technology, specifically relating to a rope polishing method for the surface of a narrow inner hole of a part. Background Technology

[0002] With the rapid development of modern science and technology, the requirements for surface quality of machined parts are becoming increasingly stringent. Grinding and polishing technology has a significant impact on the final processing quality of products, the performance of parts, the processing cost of parts, and the economic benefits of enterprises. In recent years, due to grinding burns, porosity, and other reasons on the surface of parts, there have been numerous accidents involving the breakage of critical parts during use. Grinding and polishing technology is receiving increasing attention, with people hoping to improve the quality of parts by controlling their surface quality to reduce the occurrence of safety accidents. Currently, various commonly used polishing methods all have their unavoidable drawbacks, especially for polishing metal / non-metal parts with narrow internal holes. For example, sandblasting, machine tool grinding, and laser polishing have poor accessibility for processing complex, narrow, curved surface structures; electrochemical polishing is prone to localized corrosion, and this process has poor polishing effect on the inner surface of the workpiece; although abrasive flow machining technology has high accessibility, this technology is prone to over-polishing the edges of the workpiece, thus affecting the service life of the workpiece, and it is not suitable for polishing the inner surface of thin-walled, low-rigidity structural parts. Currently, some parts are still polished manually for various reasons. However, the quality of manual polishing heavily depends on the operator's experience level, resulting in poor consistency, high labor and time costs, and the generation of toxic and harmful dust during the polishing process, which endangers human health. In summary, there is an urgent need to make breakthroughs in polishing technology, equipment, and processes for parts with narrow and elongated internal holes. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned problems and provide a rope polishing method for the surface of narrow and long internal holes of parts, which is highly safe and reliable and can overcome the shortcomings of existing polishing technology, equipment and polishing processes, such as poor accessibility to the processing of internal hole surfaces, easy damage to the workpiece surface and low polishing efficiency.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is: a rope polishing method for the surface of a narrow and elongated inner hole of a part, comprising the following steps:

[0005] S1. Obtain the part to be polished;

[0006] S2. Obtain the dimensions of the surface / hole to be polished and other information about the workpiece to be polished, create the polishing rope, set the polishing machine parameters, and select the polishing liquid;

[0007] S3. Install the polishing rope, fix the workpiece, and write the polishing control program;

[0008] S4. The polishing machine polishes according to the control program. The polishing process adopts a two-step method. The first step controls the polishing rope to perform low-speed, high-feed rough polishing on the workpiece surface, quickly reducing the surface roughness of the workpiece to one-fifth of its original value. After the rough polishing is completed, the second step controls the polishing rope to perform high-speed, low-feed fine polishing on the workpiece surface, so that the surface roughness of the workpiece meets the application index requirements.

[0009] S5. Check if the polishing has achieved the desired effect. If "yes", the process ends; otherwise, repeat the polishing process.

[0010] Furthermore, the manufacturing of the polishing rope in step S2 includes the following steps:

[0011] S201. Determine the thickness and length of the polishing material according to the size of the surface / hole to be polished, and make a polishing rope of appropriate diameter;

[0012] S202. Select the appropriate type of polishing fluid according to the material of the part to be polished;

[0013] S203, Manufacturing polishing ropes.

[0014] Furthermore, the step S2 of setting the polishing machine parameters includes the following steps:

[0015] S211. Select a suitable fixture according to the size of the workpiece to be shot;

[0016] S212. Quickly generate motion paths based on 3D models;

[0017] Motion path generation steps: First, the morphological features of the hole to be polished are obtained through reverse modeling or an existing 3D model of the workpiece; then, based on the 3D model, the differential geometric parameters of the inner hole surface are calculated. The inner hole surface is segmented according to the magnitude and distribution of the average curvature and principal curvature of the inner hole surface. Based on the effective grinding profile and processing bandwidth of the polishing rope, the feed rate and polishing speed of different areas of the workpiece are determined; the grinding and polishing contact points on the inner hole cross section are set as control vertices, and the grinding and polishing trajectory curve is fitted according to the inner hole surface profile and the diameter of the polishing rope.

[0018] S213. Based on the material removal rate and surface quality of the polishing rope on the flat workpiece under different working conditions, establish a mathematical model for the flattening material removal of the workpiece material to be polished, and select appropriate polishing speed, feed rate, and workpiece movement speed for fine polishing and rough polishing in the two-step method.

[0019] Furthermore, the installation of the polishing rope in step S3 includes the following steps:

[0020] S301. Insert both ends of the polishing rope into the holes of the polishing rope fixing head, and clamp it by screwing in the studs through the two pairs of threaded holes on the side of the polishing rope fixing head. When clamping, it is necessary to ensure that the polishing rope is in the center position.

[0021] S302. Screw the polishing rope fixing heads at both ends into the corresponding connecting shafts, ensuring that the polishing ropes have a certain tension when screwing them in.

[0022] S303. Adjust the polishing rope to make it horizontal.

[0023] S304. Rotate the anti-loosening nut to align it with the polishing rope fixing head.

[0024] Furthermore, fixing the workpiece in step S3 includes the following steps:

[0025] S311. Place the workpiece in the designated position, align it with the installation position, and clamp it with two horizontal clamps.

[0026] S312. Adjust the positioning bolts to make the workpiece reference surface horizontal.

[0027] Furthermore, in step S2, the polishing fluid selected can be a chemical-mechanical polishing fluid, mechanical abrasion, etc., depending on the requirements and specific circumstances. Generally, mechanical abrasion is used for rough polishing, and mechanical-chemical polishing is used for fine polishing. This includes the following steps:

[0028] When using chemical mechanical polishing slurry:

[0029] S221. Select appropriate pH value, oxidant and complexing agent;

[0030] S222. Select the appropriate abrasive size and concentration according to the requirements.

[0031] When using mechanical grinding: Select the appropriate abrasive size and concentration according to the requirements.

[0032] Furthermore, in step S2, the dimensions of the surface / hole to be polished and other information of the workpiece to be polished are obtained, the polishing area of ​​the workpiece to be polished is divided into several areas, and the material parameters and properties of the workpiece are obtained.

[0033] Furthermore, in step S2, the material, length, and diameter of the polishing rope are selected based on the aperture / surface curvature characteristics of the area to be polished.

[0034] Further, the polishing control procedure in step S3 is as follows: automatic tool setting, the polishing rope returns to the initial polishing contact point, the polishing rope polishing trajectory curve is fitted according to the inner hole surface profile and the polishing rope diameter, and the movement of each axis is controlled so that the workpiece moves according to the planned path. The motion path includes the conformal motion path during polishing and the path of the workpiece moving in the axial direction of the polishing rope. The conformal motion path during polishing is determined by the results of the differential geometric parameters of the inner hole surface, the effective grinding profile and processing bandwidth of the polishing rope, the polishing rope diameter, and the required polishing depth.

[0035] Furthermore, the polishing process in step S4 is divided into rough polishing and fine polishing.

[0036] Furthermore, in step S3, the polishing control program determines the workpiece moving speed and feed rate based on the polishing depth and material removal rate to ensure that the workpiece achieves the required surface quality after polishing.

[0037] Furthermore, in step S3, a polishing program is written according to the desired polishing parameters and processing path, and the polishing machine automatically polishes the workpiece based on the program.

[0038] Furthermore, when writing the motion path in step S3, it is necessary to control the contact gap between the polishing rope and the surface being processed in order to obtain the best polishing effect.

[0039] Furthermore, in step S3, the servo motors at both ends of the polishing rope rotate at the same speed but in opposite directions.

[0040] Furthermore, in step S4, the polishing process can be actively controlled by adjusting the force interaction between the polishing rope and the workpiece. This can be achieved by fixing the contact gap between the polishing rope and the workpiece or by using a polishing rope made of ferromagnetic material, and by using an external magnetic field to regulate the contact force between the polishing rope and the workpiece. Alternatively, an external electric field can be introduced to promote the chemical interaction between the workpiece and the polishing fluid, thereby enhancing the grinding effect of the polishing rope / abrasive on the reaction layer of the workpiece surface. These two approaches are key features of this polishing method and possible optimization methods to improve polishing efficiency and the surface quality of the workpiece after polishing. In addition, any other methods that are beneficial to improving the polishing effect and polishing efficiency can be added. There are various alternatives to the movement of the workpiece and the polishing rope, such as fixing the workpiece and allowing the polishing rope to move in multiple degrees of freedom, or allowing both the workpiece and the polishing rope to move in multiple degrees of freedom simultaneously.

[0041] The beneficial effects of this invention are:

[0042] 1. The present invention provides a rope polishing method for the surface of a narrow inner hole of a part. A polishing rope wrapped with polishing material is passed through the narrow inner hole and the inner wall of the workpiece is ground and polished by its high-speed rotation. At the same time, the workpiece moves along the axial direction of the polishing rope and the workpiece moves in a combined manner to achieve conformal polishing of the narrow hole with small arc / bending features of the workpiece.

[0043] 2. The polishing method disclosed in this invention has high polishing efficiency, good polishing quality, and good polishing uniformity.

[0044] 3. Compared with existing technologies, the polishing rope of this invention is smaller in size, enabling the polishing of long, straight holes. Using a polishing rope with a certain length of polishing material, the entire inner hole can be polished, with no unpolished sections. This invention uses a smaller polishing rope, capable of polishing holes with complex shapes and dimensions exceeding 5mm. Furthermore, with fixation at both ends, it ensures relatively uniform pressure between the workpiece and the polishing rope during polishing, effectively improving the shape accuracy of the tube wall.

[0045] 4. The present invention employs mechanochemical polishing during fine polishing, which will not deteriorate the surface quality of the workpiece, and the abrasive particles used will not cause environmental pollution. The use of polishing fluid for cooling can cool the working area, and the abrasive particles contained in the polishing fluid can improve the surface quality of the polished surface while increasing the polishing rate, without causing surface scratches or damage.

[0046] 5. This invention features multiple degrees of freedom, enabling the processing of complex-shaped internal holes. The polishing rope in this device is fixed at both ends, eliminating the need for connecting sections. During operation, the rotation of the polishing rope is stable.

[0047] 6. This invention can polish complex holes by moving the workpiece, and can obtain better pipe inner wall morphology characteristics while ensuring the shape accuracy of the pipe inner wall.

[0048] 7. During the polishing process of this invention, a polishing fluid can be added for cooling. While the polishing fluid removes the heat generated during polishing, the substances in it can also play a certain role in polishing efficiency.

[0049] 8. In the polishing process of this invention, an external energy field can be used to control the polishing efficiency and effect. When using an external electric field polishing method, the workpiece to be polished is used as the anode, forming a complete circuit loop with the polishing rope, the workpiece, and the external power supply, thereby effectively improving surface quality and polishing efficiency. Alternatively, by adding an external magnetic field, using a polishing rope matrix material with magnetic properties, the contact force between the rope and the workpiece can be effectively increased by controlling the magnetic field, thus improving the polishing effect. Another method is to fix the workpiece and allow the polishing rope to move freely in multiple degrees. In addition, any other methods that are beneficial to improving the polishing effect and efficiency can be added. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the steps of a rope polishing method for the surface of a narrow inner hole of a part according to the present invention;

[0051] Figure 2 This is a flowchart illustrating the usage of this invention;

[0052] Figure 3 This is a schematic diagram of the polishing machine of the present invention;

[0053] Figure 4 This is a schematic diagram of the polishing rope fixing of the present invention;

[0054] Figure 5 This is the present invention. Figure 4 A cross-sectional schematic diagram of AA in the middle;

[0055] Figure 6 This is a cross-sectional view showing the positions of the polishing rope, workpiece, and fixing device during polishing according to the present invention.

[0056] Explanation of reference numerals in the attached drawings: 1. Machine body; 2. Protective cover; 3. Clamping part; 4. Polishing rope rotating part; 4-1. High-speed motor; 4-2. Polishing rope fixing device; 5. Polishing fluid circulation part; 6. Polishing rope; 6-1. Polishing material; 6-2. Adhesive; 6-3. Base material; 8. Workpiece to be polished. Detailed Implementation

[0057] The present invention will be further described below with reference to the accompanying drawings and specific examples:

[0058] like Figures 1 to 6 As shown, the present invention provides a rope polishing method for the surface of a narrow inner hole of a part, comprising the following steps:

[0059] S1. Obtain the part to be polished.

[0060] S2. Obtain the dimensions of the surface / hole to be polished and other information about the workpiece to be polished, create a polishing rope, set the polishing machine parameters, and select the polishing liquid.

[0061] The manufacturing of the polishing rope in step S2 includes the following steps:

[0062] S201. Determine the thickness and length of the polishing material according to the size of the surface / hole to be polished, and make a polishing rope of appropriate diameter.

[0063] S202. Select the appropriate type of polishing fluid according to the material of the part to be polished.

[0064] S203, Manufacturing polishing ropes.

[0065] Step S2, determining the polishing machine parameters, includes the following steps:

[0066] S211. Select a suitable fixture based on the size of the workpiece to be shot.

[0067] S212. Quickly generate motion paths based on 3D models.

[0068] Motion path generation steps: First, the morphological features of the hole to be polished are obtained through reverse modeling or an existing 3D model of the workpiece; then, the differential geometric parameters of the inner hole surface are calculated based on the 3D model. The inner hole surface is segmented according to the magnitude and distribution of the average curvature and principal curvature of the inner hole surface. Based on the effective grinding profile and processing bandwidth of the polishing rope, the feed rate and polishing speed of different areas of the workpiece are determined; the grinding and polishing contact points on the inner hole cross section are set as control vertices, and the grinding and polishing trajectory curve is fitted according to the inner hole surface profile and the diameter of the polishing rope.

[0069] S213. Based on the material removal rate and surface quality of the polishing rope on the flat workpiece under different working conditions, establish a mathematical model for the flattening material removal of the workpiece material to be polished, and select appropriate polishing speed, feed rate, and workpiece movement speed for fine polishing and rough polishing in the two-step method.

[0070] In step S2, the polishing fluid can be selected according to requirements and specific circumstances, such as chemical mechanical polishing fluid or mechanical grinding. Generally, mechanical grinding is used for rough polishing, while mechanical chemical polishing is used for fine polishing.

[0071] When using a chemical mechanical polishing slurry, the following steps are included:

[0072] S221. Select appropriate pH value, oxidant and complexing agent;

[0073] S222. Select the appropriate abrasive size and concentration according to the requirements.

[0074] When using mechanical grinding, select the appropriate abrasive size and concentration according to the requirements.

[0075] In step S2, the dimensions of the surface / hole to be polished and other information of the workpiece to be polished are obtained. The polishing area of ​​the workpiece to be polished is divided into several areas, and the material parameters and properties of the workpiece are obtained.

[0076] In step S2, the material, length, and diameter of the polishing rope are selected based on the aperture / surface characteristics of the area to be polished.

[0077] S3. Install the polishing rope, fix the polishing parts, and write the polishing control program.

[0078] The polishing control procedure in step S3 is as follows: automatic tool setting, the polishing rope returns to the initial polishing contact point, the polishing rope polishing trajectory curve is fitted according to the inner hole surface profile and the polishing rope diameter, and the movement of each axis is controlled to make the workpiece move according to the planned path. The motion path includes the conformal motion path during polishing and the path of the workpiece moving in the axial direction of the polishing rope. The conformal motion path during polishing is calculated from the differential geometric parameters of the inner hole surface, the effective grinding profile and processing bandwidth of the polishing rope, the polishing rope diameter, and the required polishing depth.

[0079] The polishing control program in step S3 includes the motion path during polishing. The two motion paths during polishing are determined based on the surface features of the hole to be polished, the polishing rope, and the required polishing depth.

[0080] In step S3, the polishing control program determines the workpiece movement speed and feed rate based on the polishing depth and material removal rate to ensure that the workpiece achieves the required surface quality after polishing.

[0081] In step S3, a polishing program is written based on the desired polishing parameters and processing path, and the polishing machine automatically polishes the workpiece based on the program.

[0082] When writing the conformal motion path in step S3, it is necessary to control the contact gap between the polishing rope and the surface being processed in order to obtain the best polishing effect.

[0083] In step S3, the servo motors at both ends of the polishing rope rotate at the same speed but in opposite directions.

[0084] Step S3, installing the polishing rope, includes the following steps:

[0085] S301. Insert both ends of the polishing rope into the holes of the polishing rope fixing head, and clamp it by screwing in the studs through the two pairs of threaded holes on the side of the polishing rope fixing head. When clamping, it is necessary to ensure that the polishing rope is in the center position.

[0086] S302. Screw the polishing rope fixing heads at both ends into the corresponding connecting shafts, ensuring that the polishing ropes have a certain tension when screwing them in.

[0087] S303. Adjust the polishing rope to make it horizontal.

[0088] S304. Rotate the anti-loosening nut to align it with the polishing rope fixing head.

[0089] Step S3, fixing the workpiece, includes the following steps:

[0090] S311. Place the workpiece in the designated position, align it with the installation position, and clamp it with two horizontal clamps.

[0091] S312. Adjust the positioning bolts to make the workpiece reference surface horizontal.

[0092] S4. The polishing machine performs polishing according to the control program.

[0093] The polishing process in step S4 is divided into rough polishing and fine polishing. In step S4, the force interaction between the polishing rope and the workpiece can be actively controlled. This can be achieved by fixing the contact gap between the polishing rope and the workpiece, or by using a ferromagnetic polishing rope, and by using an external magnetic field to regulate the contact force between the polishing rope and the workpiece. Alternatively, an external electric field can be introduced to promote the chemical interaction between the workpiece and the polishing fluid, enhancing the grinding effect of the polishing rope / abrasive on the workpiece surface reaction layer. These two approaches are key features of this polishing method and possible optimization methods to improve polishing efficiency and the surface quality of the polished workpiece. In addition, any other methods that improve polishing effect and efficiency can be added. The movement of the workpiece and the polishing rope can have various alternatives, such as fixing the workpiece and allowing the polishing rope to move in multiple degrees of freedom, or allowing both the workpiece and the polishing rope to move in multiple degrees of freedom simultaneously.

[0094] S5. Check if the polishing has achieved the desired effect. If "yes", the process ends; otherwise, repeat the polishing process.

[0095] In this embodiment, the polishing machine includes a body 1, on which a protective cover 2, a clamping part 3, a polishing rope rotating part 4, a polishing liquid circulation part 5, and a polishing rope 6 are mounted. The clamping part 3 is located in the middle of the body 1, the protective cover 2 covers the clamping part 3, the polishing liquid circulation part 5 is located at the bottom of the clamping part 3, and the polishing rope 6 is close to the clamping part 3 and connected to the polishing rope rotating part 4.

[0096] The polishing rope 6 includes polishing material 6-1, adhesive 6-2 and base material 6-3. Adhesive 6-2 is wrapped around the base material 6-3, and polishing material 6-1 is wrapped around adhesive 6-2 to form polishing rope 6.

[0097] The fixture part 3 includes a clamp that holds and fixes the workpiece 8 to be polished. The workpiece 8 has a narrow, elongated inner hole on the part to be polished. The polishing rope rotating part 4 includes a high-speed motor 4-1 that drives the polishing rope 6 to rotate and a polishing rope fixing device 4-2. The high-speed motor 4-1 is clamped and fixed to the end of the polishing rope 6 via the polishing rope fixing device 4-2. The polishing rope fixing device 4-2 has a cuboid structure and includes a central hole for fixing the polishing rope and a threaded hole. The axis of the central hole and the axis of the threaded hole are perpendicular to each other and connected. A stud is provided in the threaded hole. After the end of the polishing rope 6 extends into the central hole of the polishing rope fixing head, the polishing rope 6 is clamped and fixed by rotating the stud. The polishing rope 6 has a processing area that contacts the workpiece to be polished, and the polishing operation is completed during the movement of the polishing rope 6 and the workpiece.

[0098] The polishing solution of the present invention comprises the following components: 0-30 wt% abrasive particles, 0-20 wt% H2O2, the remainder being deionized water, and a pH adjuster; the pH adjuster is used to adjust the pH of the polishing solution to 3-5; wt% represents the mass percentage.

[0099] Commonly used oxidizing agents include hydrogen peroxide, potassium persulfate, potassium permanganate, and ammonium persulfate.

[0100] The abrasive particles are one or more of the following: single-crystal diamond, polycrystalline diamond, aluminum oxide, zirconium dioxide, titanium dioxide, cerium dioxide, zinc oxide, aluminum-doped silicon dioxide, aluminum-coated silicon dioxide, calcined silicon dioxide, colloidal silicon dioxide, and other abrasive particles with polishing effects.

[0101] In this example, the abrasive material selected is alumina with a concentration of 20 wt%.

[0102] pH adjusters are one or more of the following: hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, boric acid, silicic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, succinic acid, azelaic acid, sebacic acid, lactic acid, malic acid, tartaric acid, citric acid, and lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide, barium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate.

[0103] The above-mentioned polishing slurry was used to perform chemical mechanical polishing on the surface of the titanium alloy workpiece (TC4 alloy in this example). By utilizing the effect of the polishing slurry on the workpiece, the inner hole surface of the titanium alloy was polished. After polishing, the surface roughness was reduced by more than an order of magnitude, which effectively improved the performance of the titanium alloy parts.

[0104] First, add deionized water, then add abrasive particles, H2O2, etc. in sequence. After all components are mixed evenly, use a pH adjuster to adjust the pH value to the target value.

[0105] In this embodiment, the high-speed motor drives the polishing rope to rotate at a speed of 4000 rad / min to 12000 rad / min. The purpose is to provide a high movement speed between the polishing rope and the tangential surface of the workpiece. The contact pressure between the polishing rope and the workpiece is controlled at 20 kPa to 50 kPa. The higher tangential speed and the larger contact pressure are conducive to achieving rapid material removal.

[0106] The present invention includes a polishing step and a polishing path planning process during use.

[0107] Polishing steps: First, fix the workpiece to be polished onto the fixture of the fixture part 3; then pass the polishing rope 6 through the narrow inner hole of the workpiece to be polished, adjust the position of the polishing rope 6 so that it has appropriate pressure with the workpiece to be polished; lock both ends of the polishing rope 6 through the existing polishing rope fixing device 4-2, and connect it to the high-speed motor 4-1 through the coupling. The high-speed rotation of the high-speed motor 4-1 drives the polishing rope 6 to rotate at high speed to achieve the polishing effect.

[0108] Polishing Path Planning: Obtain the surface characteristics of the hole / face to be polished. Based on the material properties of the workpiece and the desired surface roughness, the polishing process is divided into two stages: rough polishing and fine polishing. Obtain the relevant polishing functions for the material, and optimize parameters such as feed rate, polishing rope speed, and workpiece movement speed for each stage based on these functions. Write the processing path based on these parameters and the surface characteristics of the hole / face to be polished. Establish a polishing material removal model, and optimize the parameters based on the model, polishing depth, and processing path to obtain the desired polishing parameters for the polishing device. Write a polishing program based on these parameters and the processing path, and the polishing machine performs automatic polishing based on the polishing program.

[0109] In this embodiment, a polishing machine control module is provided on the machine body 1. The polishing machine control module is electrically connected to the electrical control equipment on the machine body 1. The polishing machine control module controls the movement of the corresponding equipment. At the same time, the polishing machine control module is an existing programmable device.

[0110] The base of the polishing rope 6 is a thin, flexible rope (such as thin steel wire, nylon, or other magnetic or non-magnetic materials). A certain length of polishing material is attached to the middle of the rope. During polishing, this part is under certain pressure with the workpiece. The high-speed motor drives the polishing rope to rotate at high speed, and the motion control system drives the workpiece to move according to the shape of the inner hole to achieve the polishing of the inner hole of the workpiece.

[0111] The selection of polishing rope speed, diameter, polishing fluid preparation, and polishing materials is as follows:

[0112] A) Polishing Rope Fabrication: Select the appropriate polishing material based on the workpiece material, and fix the material to the polishing substrate material using strong adhesive or other methods. Optional materials include polyurethane, sandpaper of different grits, polishing cloth, and other materials with polishing effects such as hand-wound rope. Select the diameter of the polishing rope's working area according to the size of the hole to be polished; generally, it only needs to be smaller than the minimum size. The length of the polishing rope's working area is determined by the length of the hole to be polished. Generally, a working area length of 1 / 3 of the hole length yields good polishing results and a shorter polishing time, resulting in better overall performance.

[0113] B) To achieve the best polishing results, this polishing method requires a multi-degree-of-freedom conformal movement. This allows for both rough and fine polishing of a single hole in a single setup. Furthermore, the feed rate, rotation speed, and contact pressure of the rope must be adjusted according to the material being polished.

[0114] C) pH control in polishing slurry; polishing slurry components: abrasive particles; polishing slurry injection method (powered by a peristaltic pump, the polishing slurry is directly sprayed into the hole to be polished through a bamboo tube).

[0115] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A rope-type polishing method for the surface of a narrow, elongated inner hole of a part, characterized in that, Includes the following steps: S1. Obtain the part to be polished; S2. Obtain the dimensions of the surface / hole to be polished, create the polishing rope, set the polishing machine parameters, and select the polishing liquid; Setting the polishing machine parameters in step S2 includes the following steps: S211. Select a suitable fixture according to the size of the workpiece to be shot; S212. Quickly generate motion paths based on 3D models; Motion path generation steps: First, the morphological features of the hole to be polished are obtained through reverse modeling or an existing 3D model of the workpiece; then, based on the 3D model, the differential geometric parameters of the inner hole surface are calculated. The inner hole surface is segmented according to the magnitude and distribution of the average curvature and principal curvature of the inner hole surface. Based on the effective grinding profile and processing bandwidth of the polishing rope, the feed rate and polishing speed of different areas of the workpiece are determined; the grinding and polishing contact points on the inner hole cross section are set as control vertices, and the grinding and polishing trajectory curve is fitted according to the inner hole surface profile and the diameter of the polishing rope. S213. Based on the material removal rate and surface quality of the polishing rope on the flat workpiece under different working conditions, establish a mathematical model for the flattening material removal of the workpiece material to be polished, and select appropriate polishing speed, feed rate and workpiece movement speed for fine polishing and rough polishing in the two-step method. S3. Install the polishing rope, fix the workpiece, and write the polishing control program; The polishing control program in step S3 is as follows: automatic tool setting, the polishing rope returns to the initial polishing contact point, the polishing rope polishing trajectory curve is fitted according to the inner hole surface profile and the polishing rope diameter, and the movement of each axis is controlled so that the workpiece moves according to the planned path; the movement path includes the conformal motion path during polishing and the path of the workpiece moving in the axial direction of the polishing rope. The conformal motion path during polishing is calculated from the differential geometric parameters of the inner hole surface, the effective grinding profile and processing bandwidth of the polishing rope, the polishing rope diameter and the required polishing depth are determined. S4. The polishing machine polishes according to the control program. The polishing process adopts a two-step method. The first step controls the polishing rope to perform low-speed, high-feed rough polishing on the workpiece surface, quickly reducing the surface roughness of the workpiece to one-fifth of its original value. After the rough polishing is completed, the second step controls the polishing rope to perform high-speed, low-feed fine polishing on the workpiece surface, so that the surface roughness of the workpiece meets the application index requirements. S5. Check if the polishing has achieved the desired effect. If "yes", the process ends; otherwise, repeat the polishing process.

2. The rope polishing method for the surface of a narrow inner hole of a part according to claim 1, characterized in that, The installation of the polishing rope in step S3 includes the following steps: S301. Insert both ends of the polishing rope into the holes of the polishing rope fixing head, and clamp it by screwing in the studs through the two pairs of threaded holes on the side of the polishing rope fixing head. When clamping, it is necessary to ensure that the polishing rope is in the center position. S302. Screw the polishing rope fixing heads at both ends into the corresponding connecting shafts, ensuring that the polishing ropes have a certain tension when screwing them in. S303. Adjust the polishing rope to make it horizontal; S304. Rotate the anti-loosening nut to align it with the polishing rope fixing head.

3. The rope polishing method for the surface of a narrow inner hole of a part according to claim 1, characterized in that, The step of fixing the workpiece in step S3 includes the following steps: S311. Place the workpiece in the designated position, align it with the installation position, and clamp it with two horizontal clamps; S312. Adjust the positioning bolts to make the workpiece reference surface horizontal.

4. The rope polishing method for the surface of a narrow inner hole of a part according to claim 1, characterized in that, The manufacturing of the polishing rope in step S2 includes the following steps: S201. Determine the thickness and length of the polishing material according to the size of the surface / hole to be polished, and make a polishing rope of appropriate diameter; S202. Select the appropriate type of polishing fluid according to the material of the part to be polished; S203, Manufacturing polishing ropes.

5. The rope polishing method for the surface of a narrow inner hole of a part according to claim 1, characterized in that, In step S2, the polishing fluid is selected according to the needs and specific circumstances, using either chemical mechanical polishing fluid or mechanical grinding; mechanical grinding is used for rough polishing, and chemical mechanical polishing is used for fine polishing. Chemical mechanical polishing includes the following steps: S221. Select appropriate pH value, oxidant and complexing agent; S222. Select the appropriate type, size and concentration of abrasive particles according to the requirements. The abrasive particles selected here are one or more of the following: single crystal diamond, polycrystalline diamond, aluminum oxide, zirconium dioxide, titanium dioxide, cerium dioxide, zinc oxide, aluminum-doped silicon dioxide, aluminum-coated silicon dioxide, calcined silicon dioxide, and colloidal silicon dioxide. When using mechanical grinding, select the appropriate abrasive size and concentration according to the requirements.

6. The rope polishing method for the surface of a narrow inner hole of a part according to claim 1, characterized in that, In step S2, the dimensions of the surface / hole to be polished are obtained, the polishing area of ​​the workpiece to be polished is divided into several areas, and the material parameters and properties of the workpiece are obtained. In step S2, the corresponding material, length and diameter of the polishing rope are selected according to the surface characteristics of the hole diameter / surface of the area to be polished.

7. The rope polishing method for the surface of a narrow inner hole of a part according to claim 1, characterized in that, In step S3, the polishing control program determines the workpiece movement speed and feed rate based on the polishing depth and material removal rate to ensure that the workpiece achieves the required surface quality after polishing. In step S3, a polishing program is written based on the desired polishing parameters and processing path, and the polishing machine automatically polishes the workpiece based on the program. When writing the motion path in step S3, the contact gap between the polishing rope and the surface being processed needs to be controlled to obtain the best polishing effect. In step S3, the servo motors at both ends of the polishing rope rotate at the same speed but in opposite directions.

8. The rope polishing method for the surface of a narrow inner hole of a part according to claim 1, characterized in that, In step S4, polishing involves actively controlling the force interaction between the polishing rope and the workpiece. This can be achieved by fixing the contact gap between the polishing rope and the workpiece, or by using a polishing rope made of ferromagnetic material, and by using an external magnetic field to regulate the contact force between the polishing rope and the workpiece; or by introducing an external electric field to promote the chemical interaction between the workpiece and the polishing fluid, thereby enhancing the grinding effect of the polishing rope / abrasive on the surface reaction layer of the workpiece. The movement of the workpiece and the polishing rope can include the workpiece being fixed and the polishing rope moving in multiple degrees of freedom, or the workpiece and the polishing rope moving in multiple degrees of freedom simultaneously.

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