Fine polishing treatment equipment for inner wall of circular hole of metal workpiece

Abstract

The invention relates to the technical field of hole diameter polishing equipment for metal parts, and discloses fine polishing treatment equipment for the inner wall of a round hole of a metal workpiece. The polishing module is arranged on the workbench and comprises a grinding head, a rotary driving source used for driving the grinding head to rotate around the axis of the grinding head, a horizontal feeding unit used for driving the grinding head to move in the radial direction of the hole diameter of the workpiece, and a lifting driving unit used for driving the grinding head to move in the hole depth direction of the workpiece. The multi-mode sensing module is used for capturing physical characteristics and polishing working conditions of workpieces in real time, the technological parameter library and the dynamic decision algorithm of the control module are combined, the working condition autonomous sensing and parameter dynamic decision ability is achieved, manual parameter adjustment is not needed, the high-precision automatic polishing operation function is achieved, and the working efficiency is improved. The inherent defect that a traditional equipment fixed parameter system is difficult to adapt to various workpieces is overcome.

Description

Technical Field

[0001] This invention relates to the field of metal part aperture polishing equipment, and more specifically, to a fine polishing equipment for the inner wall of a circular hole in a metal workpiece. Background Technology

[0002] Polishing the inner walls of circular holes in metal workpieces is a critical process in precision manufacturing, directly affecting the sealing performance and fatigue life of core components such as hydraulic valve bodies and bearing seats. Existing polishing equipment typically consists of a worktable, a three-dimensionally movable grinding head, and a workpiece rotating fixture, with relative movement between the grinding head and the workpiece achieved through mechanical transmission. Polishing parameters (such as spindle speed, feed rate, and fixture speed) are mainly preset based on operator experience, employing fixed parameter combinations to execute standardized operations. For routine batch production scenarios, this method can meet basic processing requirements.

[0003] However, when faced with the demand for flexible production of multiple varieties and small batches, existing equipment has certain shortcomings due to the use of fixed polishing parameters. For example, it cannot adaptively match the processing requirements of workpieces with different hole diameters, depths, and material properties. Especially when processing workpieces with high aspect ratio holes or large differences in material hardness, unstable polishing quality frequently occurs. The manual adjustment of parameters relies on experience and trial and error, which is difficult to respond to real-time changes in working conditions during polishing and cannot effectively compensate for process deviations caused by tool wear. At the same time, the lack of online quality monitoring and closed-loop control mechanisms leads to insufficient consistency in the polishing of the inner wall of the workpiece, which to some extent affects the pass rate of high-precision irregular-shaped workpieces and the overall efficiency of the equipment. Summary of the Invention

[0004] The purpose of this invention is to provide a fine polishing device for the inner wall of a circular hole in a metal workpiece, so as to solve the above-mentioned technical problems.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions: This invention provides a fine polishing device for the inner wall of a circular hole in a metal workpiece, comprising: Workbench; The polishing module, located on the worktable, includes: a grinding head, a rotary drive source for driving the grinding head to rotate around its own axis, a horizontal feed unit for driving the grinding head to move radially along the workpiece hole diameter, and a lifting drive unit for driving the grinding head to move along the workpiece hole depth direction. The clamping module, located on the worktable, can accommodate workpieces of different shapes and drive the workpiece to rotate around the hole axis. The multimodal sensing module includes: a vision recognition unit for acquiring workpiece shape features and hole diameter / depth dimensions; a temperature measurement unit for real-time monitoring of the grinding area temperature; a roughness measurement unit for measuring the initial and real-time surface roughness of the hole inner wall; and a grinding force measurement unit for real-time monitoring of the radial grinding force of the grinding head. The control module is connected to the polishing module, clamping module, and multimodal sensing module via signals, and is configured as follows: Workpiece type and hole diameter / depth parameters are identified based on visual recognition unit data; The initial polishing strategy is generated by calling the pre-stored process parameter library; Dynamically adjusted based on real-time data from the grinding force measurement unit and temperature measurement unit: The rotational speed of the rotary drive source, the workpiece rotational speed of the rotary driver, the radial feed rate of the horizontal feed unit, and the axial feed rate of the lifting drive assembly; Closed-loop quality control is achieved based on feedback from the roughness measurement unit.

[0006] Preferably, the lifting drive unit includes a support frame fixed to the top of the worktable, a linear telescopic source mounted on the support frame, and a slide block sliding on the support frame, wherein the telescopic end of the linear telescopic source is fixed to the slide block.

[0007] Preferably, the horizontal feed unit includes a drive motor mounted on a slide, a ball screw connected to the rotating end of the drive motor, and a movable seat slidably mounted on the slide. The movable seat is threadedly connected to the ball screw, and the rotary drive source is mounted on the movable seat.

[0008] Preferably, the rotary drive source is a servo motor, and its rotating end is detachably connected to the grinding head.

[0009] Preferably, the clamping module includes a clamp rotatably mounted on the worktable and a rotating motor connected to the rotating end of the clamp.

[0010] Preferably, the visual recognition unit is a laser contour scanner, which determines the workpiece's aperture, depth, and roundness deviation by acquiring the workpiece's three-dimensional point cloud data.

[0011] Preferably, the roughness measurement unit includes: a contact probe for measuring the initial roughness before processing and a laser confocal sensor for real-time monitoring of the surface morphology during polishing.

[0012] Preferably, the grinding force measuring unit is a six-dimensional force sensor, which is embedded in the connecting flange between the grinding head and the rotary drive source.

[0013] Preferably, the temperature measuring unit is an infrared temperature sensor arranged around the fixture.

[0014] Preferably, the control module further includes a parameter self-learning unit, configured to: record the actual parameter combinations and final roughness results in each polishing process; establish a parameter optimization model through cluster analysis; and recommend initial parameters based on similarity matching when a new workpiece type is identified.

[0015] The beneficial effects of this invention are as follows: This invention captures the physical characteristics of the workpiece and the polishing condition in real time through a multimodal sensing module. Combined with the process parameter library and dynamic decision-making algorithm of the control module, it has the ability to autonomously perceive the working condition and make dynamic decisions on parameters. It eliminates the need for manual parameter adjustment and realizes high-precision automated polishing operation. It solves the inherent defects of traditional equipment's fixed parameter system, which is difficult to adapt to a variety of workpieces. Based on the PID control mechanism of grinding force feedback and temperature monitoring, it automatically adjusts the spindle speed, feed rate and workpiece speed within a millisecond response cycle, overcoming the drawbacks of manual adjustment being lagging and unable to compensate for tool wear. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a fine polishing device for the inner wall of a circular hole in a metal workpiece provided by the present invention; Figure 2 This is a schematic diagram of the structure between the polishing module, the clamping module, and the multimodal sensing module in a fine polishing equipment for the inner wall of a circular hole in a metal workpiece provided by the present invention. Figure 3 This is a side view of the polishing module, clamping module, and multimodal sensing module in a fine polishing equipment for the inner wall of a circular hole in a metal workpiece provided by the present invention. Figure 4 This is a schematic diagram of the slide block in a fine polishing device for the inner wall of a circular hole in a metal workpiece provided by the present invention; Figure 5 This is a schematic diagram of the clamping module in a fine polishing device for the inner wall of a circular hole in a metal workpiece provided by the present invention; Figure 6 This is a cross-sectional view of the fixture in a fine polishing equipment for the inner wall of a circular hole in a metal workpiece provided by the present invention; Figure 7 This is a block diagram showing the relationship between the functional modules in a fine polishing device for the inner wall of a circular hole in a metal workpiece provided by the present invention. Figure 8 This is an operation flowchart of a fine polishing equipment for the inner wall of a circular hole in a metal workpiece, provided by the present invention.

[0017] In the diagram: 100, worktable; 200, polishing module; 201, grinding head; 202, rotary drive source; 203, support frame; 204, linear telescopic source; 205, slide; 206, drive motor; 207, ball screw; 208, moving seat; 300, clamping module; 301, fixture; 302, rotary motor; 400, multimodal sensing module; 401, vision recognition unit; 402, temperature measurement unit; 403, roughness measurement unit; 4031, connecting rod; 4032, contact needle; 4033, electric actuator; 4034, metal spring; 404, grinding force measurement unit; 500, control module. Detailed Implementation

[0018] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0019] Please refer to the following: Figure 1 , Figure 2 and Figure 7 A fine polishing device for the inner wall of a circular hole in a metal workpiece includes: a worktable 100, a polishing module 200, a clamping module 300, a multimodal sensing module 400, and a control module 500.

[0020] The polishing module 200 is mounted on the worktable 100 and includes: a polishing head 201, a rotary drive source 202 for driving the polishing head 201 to rotate around its own axis, a horizontal feed unit for driving the polishing head 201 to move radially along the workpiece hole diameter, and a lifting drive unit for driving the polishing head 201 to move along the workpiece hole depth. The lifting drive unit includes a support frame 203 fixed to the top of the worktable 100, a linear telescopic source 204 mounted on the support frame 203, and a slide block 205 sliding on the support frame 203. The linear telescopic source 204 can be an electric actuator 4033, with its telescopic end fixed to the top of the slide block 205. The horizontal feed unit includes a drive motor 206 mounted on the slide block 205, a ball screw 207 connected to the rotating end of the drive motor 206, and a movable seat 208 slidably mounted on the slide block 205. The movable seat 208 is threadedly connected to the ball screw 207, and the rotary drive source 202 is mounted on the movable seat 208. The rotary drive source 202 is a servo motor, and its rotating end is detachably connected to the grinding head 201.

[0021] The clamping module 300 is mounted on the worktable 100 and can accommodate workpieces of different shapes, and drive the workpieces to rotate around the hole axis. The clamping module 300 includes a clamp 301 rotatably mounted on the worktable 100 and a rotation motor 302 connected to the rotating end of the clamp 301.

[0022] The above-mentioned process is as follows: First, the workpiece is placed on the fixture 301 and fixed in place. Then, according to the type of workpiece, the corresponding grinding head 201 is selected and installed on the rotating end of the servo motor. By rotating the drive motor 206, the ball screw 207 drives the moving seat 208 to slide horizontally along the slide 205. The rotary drive source 202 and the grinding head 201 move laterally together until the grinding head 201 moves to the corresponding position of the workpiece's circular hole. Then, the linear extension source 20... 4. The extension causes the slide 205 to move down along the support frame 203, causing the grinding head 201 to move down and approach the workpiece. After reaching the initial grinding position of the workpiece's circular hole, the extension stops. Then, the rotation drive source 202 rotates, causing the grinding head 201 to start rotating. At the same time, the rotation motor 302 drives the fixture 301 and the workpiece to rotate, so that the grinding head 201 can uniformly grind and polish the inner wall of the workpiece's circular hole. The linear extension source 204 gradually extends, allowing the grinding head 201 to gradually penetrate into the inner wall of the circular hole for stepped grinding and polishing.

[0023] The multimodal sensing module 400 includes: a vision recognition unit 401 for acquiring workpiece shape features and hole diameter / depth dimensions; a temperature measurement unit 402 for real-time monitoring of the temperature of the grinding area; a roughness measurement unit 403 for measuring the initial and real-time surface roughness of the inner wall of the hole; and a grinding force measurement unit 404 for real-time monitoring of the radial grinding force of the grinding head 201.

[0024] Specifically, the visual recognition unit 401 is a laser contour scanner, which is installed on the top of the worktable 100. It determines the hole diameter, depth, and roundness deviation of the workpiece by acquiring the three-dimensional point cloud data of the workpiece.

[0025] The roughness measurement unit 403 includes: a contact probe for measuring the initial roughness before machining and a laser confocal sensor for real-time monitoring of the surface morphology during polishing. The contact probe is hidden on the fixture 301 and includes a connecting rod 4031, two contact needles 4032 symmetrically hinged to the top of the connecting rod 4031, and an electric push rod 4033 fixed to the bottom of the connecting rod 4031. The contact needles 4032 and the connecting rod 4031 form an angle of 45-60 degrees, and a metal spring 4034 is provided between them. The metal spring 4034 enables the contact needles 4032 to adapt to different hole diameters, ensuring that the contact needles 4032 can effectively contact the inner wall of the hole.

[0026] The roughness measuring unit 403 is used as follows: the electric push rod 4033 extends upward, driving the micro motor, connecting rod 4031 and contact needle 4032 to move upward together. When the contact needle 4032 contacts the workpiece, it begins to rotate and contract under the pressure of the workpiece, compressing the metal spring 4034. Through the adaptive contraction of the contact needle 4032, it can smoothly enter the round hole of the workpiece and fit tightly against the inner wall of the round hole. Then, the fixture 301 rotates, causing the workpiece to rotate around the connecting rod 4031. The contact needle 4032 makes uniform contact with the inner wall of the round hole of the workpiece and begins to measure the roughness of the inner wall of the round hole. At the same time, the electric push rod extends slowly, driving the contact needle 4032 to move upward and measure the roughness data of the inner wall of the round hole at different depths. After the measurement is completed, the electric push rod drives the connecting rod 4031 and the contact needle 4032 to move downward into the fixture 301 of the contraction device.

[0027] The grinding force measuring unit 404 is a six-dimensional force sensor embedded in the connecting flange between the grinding head 201 and the rotary drive source 202. The temperature measuring unit 402 consists of multiple infrared temperature sensors arranged around the fixture 301.

[0028] The control module 500 is connected to the polishing module 200, the clamping module 300, and the multimodal sensing module 400, and is configured to execute: a. Identify the workpiece type and hole diameter / depth parameters based on data from the vision recognition unit 401; b. Generate an initial polishing strategy by calling a pre-stored process parameter library; c. Dynamically adjust the following based on real-time data from the grinding force measurement unit 404 and the temperature measurement unit 402: the rotational speed of the rotary drive source 202, the workpiece rotational speed of the rotary driver, the radial feed amount of the horizontal feed unit, and the axial feed speed of the lifting drive assembly; d. Achieve closed-loop quality control based on feedback from the roughness measurement unit 403.

[0029] Please refer to the following: Figure 8 The implementation process of the above-mentioned polishing equipment is as follows: Step S100: Fix the workpiece The workpiece to be processed is fixed on the clamp 301 of the clamping module 300, ensuring that the axis of the workpiece's circular hole is coaxial with the grinding head 201.

[0030] Step S200: Multimodal data acquisition The visual recognition unit 401 obtains the workpiece type (such as hydraulic valve body - 45 steel), hole diameter D and hole depth L, the roughness measurement unit 403 measures the initial roughness Ra0 of the inner wall of the hole, and the grinding force measurement unit 404 calibrates the no-load force value F0.

[0031] Step S300: Initial Policy Generation Query the pre-stored process parameter library and load the baseline parameters: Spindle reference speed N0, workpiece reference speed Nw0 Radial feed reference F r0 Axial feed rate V z0 ; Calculate the target grinding force range: ; Among them, F ref =K × material hardness, where K is a material coefficient, for example, K=0.25 for 45 steel; Then, the polishing module 200 begins polishing the inner wall of the workpiece's circular hole according to the initial strategy.

[0032] Step S400: Dynamic parameter adjustment During the polishing process, the multimodal sensing module 400 continuously functions. Multiple infrared temperature sensors in the temperature measurement unit 402 monitor the temperature of the grinding area in real time, the six-dimensional force sensor in the grinding force measurement unit 404 monitors the radial grinding force of the grinding head 201 in real time, and the laser confocal sensor in the surface roughness measurement unit 403 monitors the surface morphology in real time. Based on this real-time data, the control module 500 dynamically adjusts the rotational speed of the rotary drive source 202, the rotational speed of the workpiece driven by the rotary driver, the radial feed amount of the horizontal feed unit, and the axial feed speed of the lifting drive assembly to ensure the stability and quality of the polishing process.

[0033] Specifically, the following closed-loop control is executed in real time: a. Grinding force feedback control (sampled every 50ms): When the real-time grinding force F deviates from the target range [Fmin, Fmax]: ; in, (Target grinding force median), K p K i PID coefficients (default value is K) p =0.15mm / N, K i =0.02mm / N); Synchronous adjustment of spindle speed: ; Wherein, λ is the material hardness compensation coefficient (0.1 for steel, 0.05 for aluminum alloy). b. Axial feed speed adjustment: ; Among them, according to the depth-to-diameter ratio V z0 Based on the base feed rate, real-time calibration is performed using roughness feedback; c. Workpiece rotation speed adaptive adjustment: based on the critical linear velocity matching the aperture D. ; Among them, V c η is the optimal linear velocity of the material (preset database call), and η is the surface quality coefficient (0.7 for fine polishing and 1.2 for rough polishing).

[0034] Step S500: Closed-loop quality verification When the surface roughness data fed back by the roughness measurement unit 403 reaches the preset quality standard, the control module 500 controls the polishing module 200 to stop working, and the entire polishing operation is completed. At this time, the operator can remove the polished workpiece from the fixture 301 for subsequent inspection or other processes.

[0035] The specific execution process is as follows: During the polishing process, the surface roughness Rat is monitored in real time using a laser confocal sensor. If |Rat - Ratarget| ≤ 0.05μm, the target is considered met; otherwise, proceed to S300 to readjust the parameters.

[0036] The above solution has the following effects: This invention acquires various data in real time during the polishing process through a multimodal sensing module 400. The control module 500 performs dynamic parameter adjustment and closed-loop quality verification based on this data, enabling the polishing equipment to have autonomous perception of working conditions and dynamic parameter decision-making capabilities. This achieves automated high-precision polishing operations and solves the problem of frequent manual parameter adjustments leading to deviations in processing quality when dealing with workpieces with high aspect ratio holes or large differences in material hardness. This effectively improves the quality and efficiency of workpiece processing and reduces labor costs.

[0037] The vision recognition unit 401 in the multimodal sensing module 400 can accurately determine information such as the hole diameter, depth, and roundness deviation of the workpiece, providing accurate basic data for subsequent polishing operations. The temperature measurement unit 402 monitors the temperature of the grinding area in real time to avoid affecting polishing quality and equipment life due to excessive temperature. The roughness measurement unit 403 can accurately measure the roughness of the inner wall of the hole, providing key basis for closed-loop quality control. The grinding force measurement unit 404 monitors the radial grinding force of the grinding head 201 in real time to ensure the stability of the polishing process.

[0038] Regarding dynamic parameter adjustment, the equipment utilizes grinding force feedback control, axial feed speed adjustment, and workpiece rotation speed adaptive adjustment to automatically adjust polishing parameters based on real-time working conditions. This effectively compensates for process deviations caused by tool wear and improves the consistency of polishing the inner wall of the workpiece. A closed-loop quality verification mechanism ensures that the polishing quality of the workpiece meets preset standards, significantly improving the pass rate of high-precision irregularly shaped workpieces.

[0039] Furthermore, the equipment features a rational structural design, with the polishing module 200, clamping module 300, and other components working in concert, making operation convenient. For example, the horizontal feed unit and lifting drive unit of the polishing module 200 can flexibly adjust the position of the grinding head 201 to accommodate workpieces of different sizes and shapes. The clamping module 300 can accommodate workpieces of different shapes and drive the workpiece to rotate around the hole axis, ensuring that the grinding head 201 uniformly polishes the inner wall of the workpiece's circular hole. Additionally, it should be noted that the control module 500 may also include a parameter self-learning unit, configured to execute: Record the actual parameter combinations and final roughness results for each polishing process; establish a parameter optimization model through cluster analysis; and recommend initial parameters based on similarity matching when a new workpiece type is identified. The parameter self-learning unit uses a reinforcement learning algorithm, and the reward function is: R = k1×(target roughness - actual roughness) + k2×grinding wheel life coefficient - k3×energy consumption coefficient; Among them, k1, k2, and k3 are weighting factors.

[0040] Additionally, the device may include a wear compensation module configured to perform the following operations: The shape of the polishing head 201 is periodically scanned by the visual recognition unit 401; The zero position of the horizontal feed unit is automatically corrected based on the wear amount ΔD of the grinding wheel diameter: The compensation displacement S = ΔD / 2 × safety factor α, where α = 1.05 - 1.2.

[0041] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. A fine polishing device for the inner wall of a circular hole in a metal workpiece, characterized in that, include: Workbench; The polishing module, located on the worktable, includes: a grinding head, a rotary drive source for driving the grinding head to rotate around its own axis, a horizontal feed unit for driving the grinding head to move radially along the workpiece hole diameter, and a lifting drive unit for driving the grinding head to move along the workpiece hole depth direction. The clamping module, located on the worktable, can accommodate workpieces of different shapes and drive the workpiece to rotate around the hole axis. The multimodal sensing module includes: a vision recognition unit for acquiring workpiece shape features and hole diameter / depth dimensions; a temperature measurement unit for real-time monitoring of the grinding area temperature; a roughness measurement unit for measuring the initial and real-time surface roughness of the hole inner wall; and a grinding force measurement unit for real-time monitoring of the radial grinding force of the grinding head. The control module is connected to the polishing module, clamping module, and multimodal sensing module via signals, and is configured as follows: Workpiece type and hole diameter / depth parameters are identified based on visual recognition unit data; The initial polishing strategy is generated by calling the pre-stored process parameter library; Dynamically adjusted based on real-time data from the grinding force measurement unit and temperature measurement unit: The rotational speed of the rotary drive source, the workpiece rotational speed of the rotary driver, the radial feed rate of the horizontal feed unit, and the axial feed rate of the lifting drive assembly; Closed-loop quality control is achieved based on feedback from the roughness measurement unit.

2. The fine polishing equipment for the inner wall of a circular hole in a metal workpiece according to claim 1, characterized in that, The lifting drive unit includes a support frame fixed to the top of the workbench, a linear telescopic source mounted on the support frame, and a slide block sliding on the support frame. The telescopic end of the linear telescopic source is fixed to the slide block.

3. The fine polishing equipment for the inner wall of a circular hole in a metal workpiece according to claim 2, characterized in that, The horizontal feed unit includes a drive motor mounted on a slide, a ball screw connected to the rotating end of the drive motor, and a movable seat slidably mounted on the slide. The movable seat is threadedly connected to the ball screw, and the rotary drive source is mounted on the movable seat.

4. The fine polishing equipment for the inner wall of a circular hole in a metal workpiece according to claim 1, characterized in that, The rotary drive source is a servo motor, and its rotating end is detachably connected to the grinding head.

5. The fine polishing equipment for the inner wall of a circular hole in a metal workpiece according to claim 1, characterized in that, The clamping module includes a clamp that is rotatably mounted on the worktable and a motor that is connected to the rotating end of the clamp.

6. The fine polishing equipment for the inner wall of a circular hole in a metal workpiece according to claim 1, characterized in that, The visual recognition unit is a laser contour scanner, which determines the workpiece's aperture, depth, and roundness deviation by acquiring the workpiece's three-dimensional point cloud data.

7. The fine polishing equipment for the inner wall of a circular hole in a metal workpiece according to claim 1, characterized in that, The roughness measurement unit includes: a contact probe for measuring the initial roughness before processing and a laser confocal sensor for real-time monitoring of the surface morphology during polishing.

8. The fine polishing equipment for the inner wall of a circular hole in a metal workpiece according to claim 1, characterized in that, The grinding force measurement unit is a six-dimensional force sensor, which is embedded in the connecting flange between the grinding head and the rotary drive source.

9. The fine polishing equipment for the inner wall of a circular hole in a metal workpiece according to claim 1, characterized in that, The temperature measurement unit is an infrared temperature sensor arranged around the fixture.

10. The fine polishing equipment for the inner wall of a circular hole in a metal workpiece according to claim 1, characterized in that, The control module also includes a parameter self-learning unit, configured to: record the actual parameter combinations and final roughness results in each polishing process; establish a parameter optimization model through cluster analysis; and recommend initial parameters based on similarity matching when a new workpiece type is identified.

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