Automatic gear tooth surface modification machining method and system

Abstract

The invention discloses an automatic gear tooth surface modification machining method and system, relates to the technical field of rolling mill production line motor coupling tooth surface modification, is applied to grinding machining through cooperation of a six-axis robot arm and laser 3D scanning, and comprises the steps that a three-dimensional model of a part to be treated is programmed and imported into a robot control module; after tooth surface chamfers are cleaned, the materials are fed to a four-claw platform, and automatic center positioning and clamping are achieved through a special tool; the position and the angle of the tooth form are corrected through a laser 3D scanner line; the six-axis robot automatically modifies according to the fine positioning track, and laser 3D scanning detection is synchronously completed; the steps of correction, recognition, machining and detection are repeated through a special tool for four times (optimal four times, combined with the length of a robot arm, one tooth can be rotated once or several teeth are set to rotate once), and full tooth surface machining is achieved. The problems that traditional manual modification chamfering is not standard, and the quality is unstable are solved, the machining precision and efficiency are improved, and the product quality stability is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of gear tooth surface modification technology for motor couplings in rolling mill production lines, specifically a method and system for automated gear tooth surface modification. Background technology... Gears are core components in mechanical transmissions and are widely used in various mechanical equipment, especially critical components such as motor couplings in rolling mill production lines. These applications place extremely high demands on gear transmission accuracy, installation adaptability, and service life. Gear manufacturing processes are complex, production cycles are long, and their unique shapes present numerous challenges in actual production and use: on the one hand, improper chamfering and inconsistent dimensions often prevent smooth installation; on the other hand, substandard chamfering can cause interference during gear operation, generating additional heat and significantly shortening the gear's lifespan.

[0003] The manufacturing cost of transmission gears for large equipment is high, and the replacement cycle is long, resulting in resource waste and affecting the normal operation of the equipment. Traditional gear tooth surface modification methods mainly rely on manual hand-held grinding machines, which have significant drawbacks: low manual processing accuracy, making it difficult to guarantee the consistency and standardization of the tooth surface contour; low processing efficiency, unable to meet the needs of mass production; high labor intensity, and processing quality is greatly affected by the operator's skill level, making it difficult to consistently meet design requirements. Therefore, there is an urgent need for an automated, high-precision gear tooth surface modification solution to address the problems existing in current technologies. Summary of the Invention

[0004] The purpose of this invention is to provide an automated gear tooth surface modification method and system to solve the problems in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for automated gear tooth surface modification, S1: Programming preparation: Obtain the 3D model of the product and program it, import the programming data into the robot control module; at the same time, build a data cloud, number the 3D model of the product according to parameters such as module, number of teeth, pressure angle, radius of curvature, and tooth height, and mark the position, length, width, and depth information of the processing area as standard reference data and store it in the cloud. S2: Pre-processing and loading: After the semi-finished gear parts to be processed are processed, the chamfer on the tooth surface is cleaned; the parts are loaded onto a four-jaw platform or a special tooling, and the parts are automatically positioned and clamped by the special tooling. S3: Correction and Positioning: The laser 3D scanner mounted on the six-axis robot arm is used to scan and identify the position and angle of the tooth shape of the part. The vision module identifies the workpiece through multi-region feature matching, accurately calculates the spatial offset, and drives the robot arm to perform compensation positioning. Hand-eye calibration is performed on the 3D scan and the robot arm to determine the position of the calibration object in the 3D scan coordinate system and the end effector coordinate system. The conversion relationship between the end effector coordinates and the sensor coordinates is calculated, and the six degrees of freedom deviation of the workpiece pose is calculated. Combined with the motion controller module, the robot trajectory is corrected online and quickly to achieve the correction accuracy. S4: Feature Recognition and Tool Matching: 3D scans the part to be processed and automatically extracts tooth profile features. Key geometric parameters such as gear module, pressure angle, and number of teeth are calculated using parameters such as tooth pitch and tooth height to establish a virtual geometric model. The virtual geometric model data is compared with the standard model data in the cloud for 3D analysis and allowance analysis to determine consistency and accurately locate the area of ​​material to be removed. Recommended grinding parameters are automatically matched from the process knowledge base. The control module identifies the part to be processed and the program path, as well as the processed and unprocessed areas, and automatically grabs the appropriate tool. S5: Automated Machining: Based on the impedance and admittance control module with force feedback, a force-position hybrid control model is established. A six-dimensional force sensor or a passive floating grinding head is integrated as the end effector to achieve dynamic and stable machining within the optimal process parameter range of the preset grinding pressure. Through the process adaptive position compensation algorithm, small position deviations caused by insufficient rigidity and backlash are identified and compensated in real time. The constant force control, position compensation and vibration suppression algorithms are integrated to form a closed-loop control and output stable joint torque commands. S6: Process Detection and Tool Change: During the machining process, the force control module monitors the tool machining torque. When the torque change exceeds the set value, the automatic tool change module is activated. At the same time, the 3D scanning module records the abnormal torque location and checks whether the location meets the drawing requirements. If it does not meet the requirements, the previous tooth is checked in sequence until a qualified tooth is found. After the tool is changed, machining starts from the next tooth after the qualified tooth. S7: Positioning process: Rotate the part angle using a special tooling, repeat steps S3-S6, each time within a 90-degree range, repeat 4 times to complete the machining of the entire tooth surface of the part; S8: Finished Product Inspection and Delivery: After processing, the 3D scanning module performs full-size inspection on the part, automatically extracts tooth profile features and establishes a virtual geometric model, and compares and analyzes it with the standard model data in the cloud; if the inspection is qualified, the part is delivered; if it is unqualified, the module determines the unqualified location, and the tool is changed to continue processing until it is qualified.

[0006] Based on the above technical solutions, the present invention also provides the following optional technical solutions: In one alternative: the optimal process parameter for grinding pressure in step S5 is 100N ± 3%.

[0007] In one alternative: in step S3, the positions of the inner hole and outer contour features in the 3D scanning coordinate system and the end effector coordinate system are determined by a multi-region feature recognition algorithm, thereby realizing the mapping of the 3D scanning results to the robot arm coordinate space.

[0008] In one alternative: In step S6, the 3D scanning module works with the indexing turntable to align the part and determine the coordinate points at the start of processing.

[0009] In one alternative: the correction accuracy in step S3 is ≤0.01mm.

[0010] Automated gear tooth surface shaping system: including Programming and data storage module: used to program the product's 3D model and import it into the control module, and to build a cloud storage standard reference data and process knowledge base; Loading and clamping module: includes a four-jaw platform and special tooling, used for parts loading, automatic center mechanical positioning and clamping; Correction and positioning module: including a six-axis robot arm, a laser 3D scanner and a vision correction module, used for part tooth shape position and angle recognition, spatial offset calculation, hand-eye calibration and robot trajectory correction; Identification and tool matching module: used to extract part tooth profile features, reverse calculate geometric parameters, perform model comparison and analysis, locate the machining area, and automatically grasp the matching tool; Force control machining module: including a six-dimensional force sensor or passive floating grinding head, and a force-position hybrid control module, used to achieve stable machining and position deviation compensation; Inspection and tool changing module: including force control module, 3D scanning inspection module and automatic tool changing module, used for torque monitoring, dimensional inspection and automatic tool changing during the machining process; Transposition module: Used to drive the rotation of parts through special tooling to achieve transposition processing.

[0011] In one alternative, a multi-station indexing turntable is also included to work with the 3D scanning module to align the part and achieve precise indexing and positioning of the part.

[0012] In one alternative: the force control module is linked with the 3D scanning detection module. When the torque change exceeds a set value, the 3D scanning detection module performs targeted detection on the abnormal position.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention automates the entire process of gear tooth surface modification, from programming preparation, material loading and clamping, correction and positioning, feature recognition, automated processing to inspection and repositioning, and finished product delivery, without the need for manual intervention, which greatly reduces labor intensity and improves processing efficiency.

[0014] This invention employs multiple technologies, including laser 3D scanning, visual correction, hand-eye calibration, and force-position hybrid control, combined with cloud data and a process knowledge base, to achieve high-precision control of the processing. The correction accuracy can reach ≤0.01mm, effectively ensuring the consistency and standardization of tooth surface shaping and solving the problems of non-standard chamfering and inconsistent dimensions in traditional manual processing.

[0015] This invention achieves real-time monitoring and dynamic adjustment of the machining process through the linkage of a force control system and a 3D scanning and detection system. It can promptly detect tool wear and machining defects, and ensure product quality stability and extend gear service life through automatic tool changing and targeted rework.

[0016] The data cloud and process knowledge base constructed by this invention are scalable and can adapt to gear processing requirements with different modules, number of teeth, pressure angles and other parameters. They are highly versatile and have a wide range of applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the process for the preliminary preparation and initial positioning stage of this invention.

[0018] Figure 2 This is a schematic diagram of the core processing and initial testing stages of the present invention.

[0019] Figure 3 This is a schematic diagram of the cyclic transposition processing stage of the present invention.

[0020] Figure 4 This is a schematic diagram of the finished product delivery stage of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0022] Example 1: An automated gear tooth surface modification method, the specific steps of which are as follows: Programming Preparation: Obtain a 3D model of the motor coupling gear of a rolling mill production line, perform offline programming on the model, generate robot machining trajectory data, and import it into the six-axis robot control module; at the same time, number the gear according to parameters such as module 2.5, number of teeth 30, pressure angle 20°, radius of curvature 15mm, and tooth height 8mm, and mark the location of the machining area (both sides of the tooth surface), length 50mm, width 10mm, and depth 2mm. Store this data as standard reference data in the cloud to build a process knowledge base containing grinding parameters for this type of gear.

[0023] Preliminary processing and loading: Clean the semi-finished gear to remove iron filings and burrs from the chamfered tooth surface; hoist the cleaned gear onto a four-jaw platform and use a special tooling to drive the four jaws to automatically center and clamp, thereby achieving automatic mechanical positioning of the gear.

[0024] Correction and Positioning: The laser 3D scanner mounted on the six-axis robotic arm is activated to perform a line scan on the gear, identifying the tooth position and angle; the vision module calculates the spatial offset of the gear as 0.03mm by matching the inner hole and outer contour features, driving the robotic arm to perform compensation positioning; hand-eye calibration is performed on the 3D scan and the robotic arm to determine the coordinates of the inner hole feature in the 3D scan coordinate system as (X1, Y1, Z1) and the coordinates in the end effector coordinate system as (X2, Y2, Z2), and the transformation relationship matrix between the two is calculated; based on this matrix, the six-degree-of-freedom deviation of the gear pose is calculated, and the robot trajectory is corrected by the motion controller, with the final correction accuracy reaching 0.008mm.

[0025] Feature recognition and tool matching: The gear to be processed is scanned in 3D, and the tooth profile features are automatically extracted. The module is calculated to be 2.5 and the number of teeth is 30 through tooth pitch measurement, which is consistent with the data in the cloud. The area of ​​material to be removed is located through 3D margin analysis. The recommended grinding pressure is matched from the process knowledge base to be 100N±3% and the grinding speed is 3000r / min. The control module identifies the unprocessed area and automatically grabs the diamond grinding head from the tool magazine.

[0026] Automated processing: The six-axis robot is started, and the diamond grinding head is controlled to process according to the preset trajectory based on the force-position hybrid control model. The six-dimensional force sensor provides real-time feedback on the grinding pressure, which is maintained between 98-103N. During the processing, the 0.005mm pose deviation caused by the equipment backlash is corrected through the process adaptive position compensation algorithm, and the integrated vibration suppression algorithm ensures the processing stability.

[0027] Process inspection and tool change: After machining 10 teeth, the force control module detects that the torque exceeds the set threshold by 15%, determines that the tool is worn, and starts the automatic tool change module; the 3D scanning module records the position of the 10th tooth and detects it. It finds that the tooth size is out of tolerance, so it continues to detect the 9th tooth. After the detection is qualified, the position is recorded. After tool change, machining starts from the 11th tooth.

[0028] Transposition machining: Drive the gear to rotate 90° using a special tooling, repeat steps 3-6, and complete the machining of the four 90° areas in sequence.

[0029] Finished product inspection and delivery: After the entire tooth surface is machined, the 3D scanning module performs full-size inspection of the gear, extracts tooth profile features to establish a virtual geometric model, compares it with the standard model in the cloud, and finds that all dimensions are within tolerance range. The inspection is qualified, and the material is then cut and delivered for installation.

[0030] Example 2: An automated gear tooth surface modification system includes a programming and data storage module, a material loading and clamping module, a calibration and positioning module, an identification and tool matching module, a force control machining module, a detection and tool changing module, a position changing module, and a multi-station indexing rotary table.

[0031] The programming and data storage module utilizes an industrial computer, equipped with 3D model programming software and a cloud database, capable of storing standard data and process parameters for 100 different gear specifications. The loading and clamping module includes a four-jaw hydraulic chuck and dedicated centering fixtures, achieving a centering accuracy of ≤0.01mm. The calibration and positioning module employs a six-axis industrial robot, a laser 3D scanner (scanning accuracy 0.005mm), and a vision processing module with a built-in multi-region feature matching algorithm. The recognition and tool matching module integrates feature extraction software and an automatic tool gripping device. The tool magazine can accommodate 20 different types of machining tools; the force control machining module is equipped with a six-dimensional force sensor (measurement accuracy 0.1N) and a passive floating grinding head, and the control module adopts a PLC-based force-position hybrid controller; the force control module of the detection and tool changing module sets the torque threshold range, the 3D scanning detection module can realize real-time online detection, and the automatic tool changing module has a tool changing time of ≤5s; the positioning module uses a servo motor to drive the tool rotation, with an angular accuracy of ≤0.001°; the multi-station indexing turntable has 4 stations, which can realize precise indexing and positioning of parts.

[0032] When the module is running, the three-dimensional model of the gear and the programming data are imported through the programming and data storage module. The feeding and clamping module realizes the positioning and clamping of the part. The calibration and positioning module completes the precise positioning. The identification and tool matching module realizes feature recognition and tool matching. The force control machining module performs automated machining. The detection and tool changing module monitors and changes tools in real time. The shifting module and the multi-station indexing turntable work together to realize the machining of the entire gear surface. Finally, qualified delivery is achieved through finished product inspection.

[0033] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An automated gear tooth surface modification method, characterized in that, Includes the following steps: S1: Programming Preparation: Obtain the 3D model of the product and program it, then import the programming data into the robot control module; at the same time, build a data cloud, number the 3D model of the product according to parameters such as module, number of teeth, pressure angle, radius of curvature, and tooth height, and mark the location, length, width, and depth information of the processing area as standard reference data and store it in the cloud. S2: Pre-processing and loading: After the semi-finished gear parts to be processed are processed, the chamfer on the tooth surface is cleaned; the parts are loaded onto a four-jaw platform or a special tooling, and the parts are automatically positioned and clamped by the special tooling. S3: Correction and Positioning: The laser 3D scanner mounted on the six-axis robot arm is used to scan and identify the position and angle of the tooth shape of the part. The vision module identifies the workpiece through multi-region feature matching, accurately calculates the spatial offset, and drives the robot arm to perform compensation positioning. Hand-eye calibration is performed on the 3D scan and the robot arm to determine the position of the calibration object in the 3D scan coordinate system and the end effector coordinate system. The conversion relationship between the end effector coordinates and the sensor coordinates is calculated, and the six degrees of freedom deviation of the workpiece pose is calculated. Combined with the motion controller module, the robot trajectory is corrected online and quickly to achieve the correction accuracy. S4: Feature Recognition and Tool Matching: 3D scans the part to be processed and automatically extracts tooth profile features. Key geometric parameters such as gear module, pressure angle, and number of teeth are calculated using parameters such as tooth pitch and tooth height to establish a virtual geometric model. The virtual geometric model data is compared with the standard model data in the cloud for 3D analysis and allowance analysis to determine consistency and accurately locate the area of ​​material to be removed. Recommended grinding parameters are automatically matched from the process knowledge base. The control module identifies the part to be processed and the program path, as well as the processed and unprocessed areas, and automatically grabs the appropriate tool. S5: Automated Machining: Based on the impedance and admittance control module with force feedback, a force-position hybrid control model is established. A six-dimensional force sensor or a passive floating grinding head is integrated as the end effector to achieve dynamic and stable machining within the optimal process parameter range of the preset grinding pressure. Through the process adaptive position compensation algorithm, small position deviations caused by insufficient rigidity and backlash are identified and compensated in real time. The constant force control, position compensation and vibration suppression algorithms are integrated to form a closed-loop control and output stable joint torque commands. S6: Process Detection and Tool Change: During the machining process, the force control module monitors the tool machining torque. When the torque change exceeds the set value, the automatic tool change module is activated. At the same time, the 3D scanning module records the abnormal torque location and checks whether the location meets the drawing requirements. If it does not meet the requirements, the previous tooth is checked in sequence until a qualified tooth is found. After the tool is changed, machining starts from the next tooth after the qualified tooth. S7: Positioning and machining: Rotate the part angle using a special tooling, repeat steps S3-S6, machining within a 90-degree range each time, repeating 4 times, with 4 times being optimal. Combined with the length of the robot arm, it is also possible to rotate once for each tooth, or set several teeth to rotate once, to complete the machining of the entire tooth surface of the part. S8: Finished Product Inspection and Delivery: After processing, the 3D scanning module performs full-size inspection on the part, automatically extracts tooth profile features and establishes a virtual geometric model, and compares and analyzes it with the standard model data in the cloud; if the inspection is qualified, the part is delivered; if it is unqualified, the module determines the unqualified location, and the tool is changed to continue processing until it is qualified.

2. The automated gear tooth surface modification method according to claim 1, characterized in that, The optimal process parameter for grinding pressure in step S5 is 100N±3%.

3. The automated gear tooth surface modification method according to claim 1, characterized in that, In step S3, the positions of the inner hole and outer contour features in the 3D scanning coordinate system and the end effector coordinate system are determined by the multi-region feature recognition algorithm, so as to realize the mapping of the 3D scanning results to the robot arm coordinate space.

4. The automated gear tooth surface modification method according to claim 1, characterized in that, In step S6, the 3D scanning module works with the indexing turntable to align the part and determine the coordinate points at the start of processing.

5. The automated gear tooth surface modification method according to claim 1, characterized in that, The correction accuracy in step S3 is ≤0.01mm.

6. An automated gear tooth surface modification system for implementing the method of any one of claims 1-4, characterized in that, include Programming and data storage module: used to program the product's 3D model and import it into the control module, and to build a cloud storage standard reference data and process knowledge base; Loading and clamping module: includes a four-jaw platform and special tooling, used for parts loading, automatic center mechanical positioning and clamping; Correction and positioning module: including a six-axis robot arm, a laser 3D scanner and a vision correction module, used for part tooth shape position and angle recognition, spatial offset calculation, hand-eye calibration and robot trajectory correction; Tool identification and matching module: used to extract part tooth profile features, reverse calculate geometric parameters, perform model comparison and analysis, locate the machining area, and automatically grasp the matching tool; Force control machining module: including a six-dimensional force sensor or passive floating grinding head, and a force-position hybrid control module, used to achieve stable machining and position deviation compensation; Inspection and tool changing module: including force control module, 3D scanning inspection module and automatic tool changing module, used for torque monitoring, dimensional inspection and automatic tool changing during the machining process; Transposition module: Used to drive the rotation of parts through special tooling to achieve transposition processing.

7. The automated gear tooth surface modification system according to claim 5, characterized in that, It also includes a multi-station indexing turntable, which is used in conjunction with the 3D scanning module to align the position of the parts and achieve precise indexing and positioning of the parts.

8. The automated gear tooth surface modification system according to claim 5, characterized in that, The force control module is linked with the 3D scanning detection module. When the torque change exceeds the set value, the 3D scanning detection module performs targeted detection on the abnormal position.

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