High-precision grinding machining method for needle bearing

Abstract

The high-precision grinding machining method for the needle bearing comprises the steps that S1, a needle bearing ring to be ground is placed on a mounting table of a three-dimensional fine adjustment mechanism through a mechanical arm, a ring clamp is started to conduct rigid positioning on the needle bearing ring, and a tool setting gauge scans the needle bearing ring; s2, the numerical control bearing grinding machine drives a grinding wheel to machine and grind the inner ring of the needle bearing ring, a temperature detection module detects the temperature change, and a visual detection module scans the inner diameter data of the needle bearing ring in real time; and S3, the grinding wheel is dynamically adjusted according to the grinding wheel feeding correction control instruction obtained through scanning of the visual detection module, and the feeding rate is finely adjusted. The inner diameter data of the ferrule is scanned in real time through the visual detection module, grinding thermal deformation is monitored in real time in combination with the temperature detection module, a whole-process closed loop of detection-analysis-correction of machining errors is achieved, 10-30 min delay of traditional off-line detection is shortened to millisecond response, and the purpose of high-precision machining is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of needle roller bearing processing, in particular to a high-precision grinding method for needle roller bearings. Background Art

[0002] Needle roller bearing grinding is a process of cutting the surface of needle roller bearings using grinding tools. With the help of high-speed rotation and precise motion control of the grinding tools, excess material on the surface of the parts is removed to achieve high-precision dimensional tolerances, surface roughness and geometric shape requirements, thereby ensuring the assembly accuracy, operating performance and service life of the needle roller bearings.

[0003] However, in the traditional inspection process, workpieces must be removed from the machine tool after the grinding process is completed and transported manually or through logistics systems to offline inspection equipment such as coordinate measuring machines and roundness meters for accuracy testing. There is often a 10-30 minute delay before test results are fed back to the machining system. This physical separation of inspection and machining makes it impossible to dynamically compensate for positioning errors, thermal deformation errors, and grinding wheel wear errors that occur in real time during machining, making high-precision grinding of needle roller bearings impossible.

[0004] Therefore, we proposed a high-precision grinding method for needle roller bearings to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-precision grinding method for needle roller bearings to solve the problem proposed in the above-mentioned background technology that there is often a time delay of 10-30 minutes when the detection results are fed back to the processing system, and the positioning error, thermal deformation error, and grinding wheel wear error generated in real time during the processing cannot be dynamically compensated, thereby making it impossible to perform high-precision grinding of needle roller bearings.

[0006] To achieve the above object, the present invention provides the following technical solution: a high-precision grinding method for needle roller bearings, comprising the following steps:

[0007] S1. Use a robotic arm to place the needle roller bearing ring to be ground on the mounting platform of the three-dimensional fine-tuning mechanism. The temperature sensor at the center of the three-dimensional fine-tuning mechanism is set at the center of the needle roller bearing. Start the ring fixture to rigidly position the needle roller bearing ring. Scan the needle roller bearing ring with a tool setter to generate a workpiece space coordinate system compensation matrix containing six-dimensional deviations, establish a reference surface geometric error correction model, and generate workpiece space data.

[0008] S2. The CNC bearing grinder drives the grinding wheel to grind the inner ring of the needle roller bearing ring. The temperature detection module detects the temperature changes caused by grinding in real time and calls the temperature control device to control the temperature of the ring. The visual inspection module scans the inner diameter data of the needle roller bearing ring in real time.

[0009] S3. The grinding wheel is dynamically adjusted according to the grinding wheel feed correction control command obtained by the visual inspection module, and the feed rate is fine-tuned. When the inner diameter expansion trend is detected, the feed rate is automatically reduced by 0.1mm / min; if a shrinkage deviation occurs, the feed rate is increased by 0.05mm / min to ensure that the dimensional tolerance during the grinding stage is stable within ±10μm;

[0010] S4. The control terminal collects workpiece space data, temperature change data and inner diameter grinding change data, integrates and analyzes the data, generates positioning parameter coordinates and grinding parameter corrections for the next batch of processing, and feeds them back to the CNC bearing grinder for subsequent grinding processing.

[0011] Preferably, in step S1, the tool setting probe scans the needle roller bearing ring, and the scanning range includes the spatial position of the axial end face of the ring and the spatial position of the middle of the ring.

[0012] Preferably, the temperature detection module includes a multi-point temperature sensing component, a temperature data acquisition device and a temperature data processor. The multi-point temperature sensing component collects temperature data in the CNC bearing grinder and transmits the temperature data to the inside of the temperature data acquisition device through a data line. The temperature data acquisition device then transmits the temperature data to the inside of the temperature data processor for temperature data analysis, compares it with the standard temperature range, and generates a temperature control instruction. When the local temperature rise exceeds 1°C, the control instruction processor triggers the temperature control device, and uses the blower to deliver clean cold air to the grinding area through the cooling air duct to control the surface temperature fluctuation of the ring within ±0.8°C.

[0013] Preferably, the points collected by the multi-point temperature sensing assembly include the mounting table of the three-dimensional fine-tuning mechanism, the clamping surface of the ring fixture and the grinding wheel spindle. The temperature of the clamping surface of the ring fixture is detected to detect the temperature of the contact surface to avoid clamping thermal stress deformation. The temperature change of the grinding wheel spindle is detected to prevent the spindle from elongating due to heat. The temperature rise data collected by the multi-point temperature sensing assembly is not only used for real-time temperature control, but also can provide data support for processing technology optimization.

[0014] Preferably, the temperature control device includes a control instruction processor, a cooling air duct, an electric control valve and a blower. The control instruction processor receives the temperature control instruction issued by the temperature detection module, opens the electric control valve and starts the blower. The blower blows clean cold air into the interior of the needle roller bearing through the cooling air duct to control and cool it.

[0015] Preferably, the visual inspection module in step S2 includes a laser diameter gauge, an industrial-grade camera, a video data integrator and a video data processor. The laser diameter gauge and the industrial-grade camera transmit the collected video data to the inside of the data integrator, integrate the two types of video data, and then pass the integrated data to the inside of the video data processor for video data analysis. The measurement accuracy of the laser diameter gauge is ±0.5μm, and the sampling frequency is 100Hz; the shooting pixel of the industrial-grade camera is 12K pixels, and the frame rate is 5000fps.

[0016] Preferably, the video data analysis includes:

[0017] S21. Performing noise reduction processing on the integrated video data, retaining effective contour feature points, and enhancing the image to highlight the images of the middle and end faces of the ferrule;

[0018] S22, extracting geometric features from the images of the middle and end faces of the ferrule, performing fitting comparison with the standard size data, and obtaining corresponding difference data;

[0019] S23. Generate a control instruction for the grinding wheel feed correction amount based on the difference data and transmit it to the interior of the CNC bearing grinder.

[0020] Preferably, the three-dimensional fine-tuning mechanism drives the mounting platform to perform fine-tuning by controlling a high-precision direct-drive servo motor.

[0021] Preferably, a pressure sensor is fixedly installed on the clamping surface of the ring clamp, and the pressure sensor detects the extrusion force between the clamp and the ring. The pressure sensor has a range of 0-50N and dynamically detects the contact stress between the clamp and the ring to ensure that the clamping force is evenly distributed.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. This method uses a visual inspection module to scan the inner diameter of the ring in real time, combined with a temperature detection module to monitor grinding thermal deformation in real time, to achieve a closed-loop process of "detection-analysis-correction" for machining errors. This shortens the 10-30 minute delay of traditional offline detection to a millisecond-level response, ensuring that the raceway diameter tolerance is controlled within ±2μm, achieving the goal of high-precision machining.

[0024] 2. The multi-point temperature sensing assembly collects real-time temperature rise data from the mounting platform, fixture clamping surface, and grinding wheel spindle of the three-dimensional fine-tuning mechanism, covering the main heat sources in the grinding process. This allows for comprehensive and accurate measurement of the internal temperature of the CNC bearing grinder. It then works with the temperature control equipment to rapidly cool the needle roller bearing rings, preventing problems such as bearing lubrication failure and thermal expansion and deformation of mechanical components caused by spindle overheating. Furthermore, the temperature rise data collected by the multi-point temperature sensing assembly provides data support for machining process optimization. By analyzing the temperature variation patterns at each point under different grinding parameters (such as grinding wheel speed and feed rate), machining process parameters can be optimized inversely to achieve a balance between grinding efficiency and machining accuracy.

[0025] 3. The control terminal uses workpiece spatial data such as the ring reference surface geometry parameters and the positioning deviation matrix of the three-dimensional fine-tuning mechanism acquired by a high-precision tool setter. Combined with temperature data such as the real-time temperature rise curve of the grinding area and the operating parameters of the temperature control equipment collected by the multi-point temperature sensor component, as well as grinding dimension data such as the ring inner diameter dimension fluctuation curve and the grinding wheel adjustment history feedback from the visual inspection module, the control terminal uses a deep learning-based error prediction algorithm and adaptive compensation model to perform feature extraction and correlation analysis on the data. As a result, the system can accurately calculate and generate correction parameters for the next batch of processing, achieve iterative improvement in processing accuracy, ensure the continuous convergence of key dimensional tolerances and form and position errors of needle roller bearings, and significantly improve product quality stability and production consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flowchart of a high-precision grinding method for needle roller bearings. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the implementation regulations described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] See also Figure 1 The present invention provides a technical solution: a high-precision grinding method for needle roller bearings, comprising the following steps:

[0029] S1. Use a robotic arm to place the needle roller bearing ring to be ground on the mounting platform of the three-dimensional fine-tuning mechanism. The temperature sensor at the center of the three-dimensional fine-tuning mechanism is set at the center of the needle roller bearing to monitor the temperature change of the reference surface in real time. The ring fixture is started to rigidly position the needle roller bearing ring, and the tool setting instrument scans the needle roller bearing ring.

[0030] When the tool setter scans the needle roller bearing ring, the scanning range includes the spatial position of the axial end face of the ring and the spatial position of the middle of the ring. When scanning the axial end face, the tool setter moves along the diameter direction at a speed of 0.5mm / s for detection;

[0031] The scanned data is processed by the CNC system of the tool setting instrument to generate a workpiece space coordinate system compensation matrix containing six-dimensional deviations, establish a reference surface geometric error correction model, and generate workpiece space data.

[0032] The three-dimensional fine-tuning mechanism drives the mounting table for fine-tuning by controlling a high-precision direct-drive servo motor. A pressure sensor is fixedly installed on the clamping surface of the ring fixture. The pressure sensor detects the extrusion force between the fixture and the ring. The pressure sensor has a range of 0-50N and dynamically detects the contact stress between the fixture and the ring to ensure uniform distribution of the clamping force and realize dual-reference rigid positioning of the end face and the outer diameter surface.

[0033] S2. The CNC bearing grinder drives the grinding wheel to grind the inner ring of the needle roller bearing ring. The temperature detection module detects the temperature changes caused by grinding in real time and calls the temperature control device to control the temperature of the ring. The visual inspection module scans the inner diameter data of the needle roller bearing ring in real time.

[0034] The temperature detection module includes a multi-point temperature sensing assembly, a temperature data acquisition device, and a temperature data processor. The multi-point temperature sensing assembly collects temperature data from the CNC bearing grinder. The temperature data is connected to the temperature data acquisition device via a dedicated data line. After filtering and noise reduction, it is transmitted to the temperature data processor. The processor compares the real-time temperature with a preset reference range (20±0.5°C) and generates a temperature control instruction. When the local temperature rise exceeds 1°C, the control instruction processor triggers the temperature control device, which uses a blower to deliver clean cold air through the cooling air duct to the grinding area, controlling the ring surface temperature fluctuation within ±0.8°C.

[0035] The multi-point temperature sensing assembly collects data at locations including the mounting platform of the three-dimensional fine-tuning mechanism, the clamping surface of the ferrule fixture, and the grinding wheel spindle. The ferrule fixture clamping surface is used to detect contact surface temperature and prevent deformation caused by thermal stress. The grinding wheel spindle's temperature change is monitored to prevent elongation due to heat. The temperature rise data collected by the multi-point temperature sensing assembly is not only used for real-time temperature control but also provides data support for process optimization. By analyzing the temperature variation patterns at each point under different grinding parameters (such as grinding wheel speed and feed rate), the process parameters can be optimized inversely to achieve a balance between grinding efficiency and machining accuracy.

[0036] The temperature control equipment includes a control command processor, cooling duct, electronically controlled valve, and blower. The control command processor receives the temperature control command from the temperature detection module, opens the electronically controlled valve, and starts the blower. The blower blows clean, cold air through the cooling duct into the needle roller bearing, controlling and cooling it. If the temperature rise rate exceeds a preset threshold, the temperature control equipment immediately intervenes to prevent problems such as spindle overheating that can lead to bearing lubrication failure and thermal expansion and deformation of mechanical components. Actual testing has shown that adopting this temperature control solution has extended the replacement cycle of the grinding wheel spindle bearing by 40% and reduced equipment downtime due to thermal failure by 60%, significantly improving the equipment's operational stability and overall service life, while reducing equipment maintenance costs.

[0037] The visual inspection module in S2 includes a laser diameter gauge, an industrial-grade camera, a video data integrator, and a video data processor. The laser diameter gauge and the industrial-grade camera transmit the collected video data to the data integrator, integrate the two types of video data, and then pass the integrated data to the video data processor for video data analysis. The measurement accuracy of the laser diameter gauge is ±0.5μm, and the sampling frequency is 100Hz; the shooting pixel of the industrial-grade camera is 12K pixels, and the frame rate is 5000fps.

[0038] Video data analysis includes:

[0039] 1. Perform noise reduction on the integrated video data, retain effective contour feature points, and enhance the image to highlight the images of the middle and end faces of the ferrule;

[0040] 2. Extract the geometric features from the images of the middle and end faces of the ferrule, perform fitting comparison with the standard size data, and obtain the corresponding difference data;

[0041] 3. Generate the control instruction of the grinding wheel feed correction amount based on the difference data and transmit it to the interior of the CNC bearing grinder.

[0042] S3. The CNC bearing grinder uses the inner diameter deviation feedback from the visual inspection module, combined with the real-time monitoring of grinding wheel wear and grinding force, to derive the grinding wheel feed correction control instruction and dynamically adjust the grinding wheel feed rate: when an inner diameter expansion trend is detected, the feed rate is automatically reduced by 0.1mm / min; if a contraction deviation occurs, the feed rate is increased by 0.05mm / min to ensure that the dimensional tolerance during the grinding stage is stable within ±10μm;

[0043] S4. The control terminal collects workpiece space data, temperature change data and inner diameter grinding change data, integrates and analyzes the data, generates positioning parameter coordinates and grinding parameter corrections for the next batch of processing, and feeds them back to the CNC bearing grinder for subsequent grinding processing.

[0044] The high-precision grinding method for needle roller bearings proposed in this invention establishes an intelligent, closed-loop precision manufacturing system. During the execution phase, a robotic arm precisely places the needle roller bearing ring to be ground on the mounting platform of a three-dimensional fine-tuning mechanism. A high-precision temperature sensor at the center of this mechanism instantly monitors the center temperature of the ring in real time. Subsequently, the ring fixture achieves rigid positioning of the ring through uniform clamping force feedback from a pressure sensor. A three-coordinate laser tool setter collects the spatial geometric parameters of the ring's axial end face and mid-outer diameter, providing a precise benchmark for subsequent processing.

[0045] When a CNC bearing grinder drives the grinding wheel to rough-machine the inner ring, a multi-point temperature sensing assembly simultaneously monitors the entire temperature range of key heat sources, including the 3D fine-tuning mechanism mounting platform, the fixture clamping surface, and the grinding wheel spindle. Once an abnormal temperature rise is detected, the temperature control equipment immediately activates the blower and cooling duct to deliver constant-temperature cold air, achieving rapid millisecond-level cooling of the ring, effectively mitigating equipment failure risks such as spindle lubrication failure and thermal expansion of mechanical components. Simultaneously, the visual inspection module uses a laser diameter gauge and an industrial linear array camera to scan the inner diameter of the ring in real time. Combined with temperature detection data, it calculates thermal deformation errors in real time, forming a fully closed-loop control chain of "detection-analysis-correction."

[0046] The control terminal, serving as the core of intelligent decision-making, integrates a multi-source heterogeneous data processing platform. This deeply integrates workpiece spatial data, such as the ferrule reference surface geometry parameters acquired by the tool setter and the positioning deviation matrix of the 3D fine-tuning mechanism, with thermal data such as the real-time heating curve and temperature control equipment operating parameters collected by the temperature sensor component, as well as grinding process data such as inner diameter dimensional fluctuations from visual inspection and grinding wheel adjustment records. A deep learning-based error prediction algorithm and adaptive compensation model, through feature extraction and correlation analysis, accurately generate correction plans for the next batch of machining, including parameters such as positioning coordinate compensation values, grinding wheel feed rate correction coefficients, and grinding depth compensation. This significantly improves product quality stability and production process consistency.

[0047] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-precision grinding method for needle roller bearings, characterized in that: The following steps are involved: S1. Use a robotic arm to place the needle roller bearing ring to be ground on the mounting platform of the three-dimensional fine-tuning mechanism. The temperature sensor at the center of the three-dimensional fine-tuning mechanism is set at the center of the needle roller bearing. Start the ring fixture to rigidly position the needle roller bearing ring. Use a tool setting probe to scan the needle roller bearing ring to generate workpiece spatial data. S2. The CNC bearing grinder drives the grinding wheel to grind the inner ring of the needle roller bearing ring. The temperature detection module detects the temperature changes caused by grinding in real time and calls the temperature control device to control the temperature of the ring. The visual inspection module scans the inner diameter data of the needle roller bearing ring in real time. S3, the grinding wheel is dynamically adjusted according to the grinding wheel feed correction control instruction obtained by the visual inspection module, and the feed rate is fine-tuned; S4. The control terminal collects workpiece space data, temperature change data and inner diameter grinding change data, integrates and analyzes the data, generates positioning parameter coordinates and grinding parameter corrections for the next batch of processing, and feeds them back to the CNC bearing grinder for subsequent grinding processing.

2. The high-precision grinding method for needle roller bearings according to claim 1, characterized in that: In step S1, the tool setting probe scans the needle roller bearing ring, and the scanning range includes the spatial position of the axial end surface of the ring and the spatial position of the middle of the ring.

3. The high-precision grinding method for needle roller bearings according to claim 1, characterized in that: The temperature detection module includes a multi-point temperature sensing component, a temperature data acquisition device and a temperature data processor. The multi-point temperature sensing component collects temperature data from the CNC bearing grinder and transmits the temperature data to the inside of the temperature data acquisition device through a data line. The temperature data acquisition device then transmits the temperature data to the inside of the temperature data processor for temperature data analysis, compares it with the standard temperature range, and generates temperature control instructions.

4. The high-precision grinding method for needle roller bearings according to claim 3, characterized in that: The points collected by the multi-point temperature sensing component include the mounting platform of the three-dimensional fine-tuning mechanism, the clamping surface of the ring fixture and the grinding wheel spindle.

5. The high-precision grinding method for needle roller bearings according to claim 1, characterized in that: The temperature control equipment includes a control instruction processor, a cooling air duct, an electric control valve and a blower. The control instruction processor receives the temperature control instruction issued by the temperature detection module, opens the electric control valve and starts the blower. The blower blows clean cold air into the interior of the needle roller bearing through the cooling air duct to control and cool it.

6. The high-precision grinding method for needle roller bearings according to claim 1, characterized in that: The visual inspection module in step S2 includes a laser diameter gauge, an industrial-grade camera, a video data integrator and a video data processor. The laser diameter gauge and the industrial-grade camera transmit the collected video data to the inside of the data integrator, integrate the two types of video data, and then pass the integrated data to the inside of the video data processor for video data analysis.

7. The high-precision grinding method for needle roller bearings according to claim 6, characterized in that: Video data analysis includes: S21. Performing noise reduction processing on the integrated video data, retaining effective contour feature points, and enhancing the image to highlight the images of the middle and end faces of the ferrule; S22, extracting geometric features from the images of the middle and end faces of the ferrule, performing fitting comparison with the standard size data, and obtaining corresponding difference data; S23. Generate a control instruction for the grinding wheel feed correction amount based on the difference data and transmit it to the interior of the CNC bearing grinder.

8. The high-precision grinding method for needle roller bearings according to claim 1, characterized in that: The three-dimensional fine-tuning mechanism drives the mounting platform for fine-tuning by controlling a high-precision direct-drive servo motor.

9. The high-precision grinding method for needle roller bearings according to claim 1, characterized in that: A pressure sensor is fixedly installed on the clamping surface of the ferrule fixture, and the pressure sensor detects the extrusion force between the fixture and the ferrule.

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