Abstract: The research of automatic tool setting technology for gear shaper cutters on special CNC grinding machines. It introduces methods to improve the efficiency and accuracy of tool setting, leveraging acoustic emission (AE) technology and optimized algorithms. The research aims to enhance the precision of gear shaper cutters and streamline the manufacturing process.
1. Introduction
Gear shaping is a critical process in gear manufacturing, where the precision of the gear shaper cutter directly impacts the quality of the final gear. The automatic tool setting technology for gear shaper cutters on CNC grinding machines plays a vital role in ensuring high precision and efficiency. Traditional manual tool setting methods are time-consuming and prone to errors, necessitating the development of automatic tool setting technologies.
This thesis explores two main areas: automatic tool setting for wheel dressing and optimization of automatic centering methods for grinding. By employing advanced technologies and optimization algorithms, this research aims to enhance the performance of CNC grinding machines dedicated to gear shaper cutters.
2. Automatic Tool Setting for Wheel Dressing
2.1 Purpose and Method Determination
The primary purpose of wheel dressing is to maintain the geometric shape and sharpness of the grinding wheel, which directly affects the precision of the workpiece. Automatic tool setting for wheel dressing can improve processing accuracy and reduce occupational hazards.
2.2 Selection, Installation, and Wiring of Acoustic Emission System
Acoustic emission (AE) technology is utilized to detect the contact state between the grinding wheel and the diamond roller during dressing. The AE signals generated during contact are monitored to determine the actual contact status. The selection, installation, and wiring of the AE system are crucial for the successful implementation of automatic tool setting.
Table 1: AE System Components and Their Functions
| Component | Function |
|---|---|
| AE Sensor | Detects AE signals generated during wheel dressing |
| Signal Conditioner | Amplifies and filters AE signals for better analysis |
| Data Acquisition Unit | Collects and processes AE signals |
2.3 Monitoring of Diamond Roller and Grinding Wheel Contact
To monitor the contact between the diamond roller and the grinding wheel, a threshold triggering method is employed. When the AE signal exceeds a predefined threshold, it indicates contact between the two components.
2.4 Tool Path Planning
The planning of the tool path ensures efficient and accurate movement of the diamond roller relative to the grinding wheel. A reasonable tool path is crucial for achieving optimal dressing results.
2.5 Implementation on CNC Machine
The implementation of automatic tool setting for wheel dressing involves the development of a human-machine interface (HMI) and the programming of CNC code. The HMI allows operators to input parameters and monitor the dressing process, while the CNC code controls the movement of the diamond roller.
Table 2: Functions of the HMI for Wheel Dressing
| Function | Description |
|---|---|
| Parameter Input | Allows input of dressing parameters |
| Status Monitoring | Displays the current status of the dressing process |
| Error Handling | Provides alerts and troubleshooting guidance |
3. Optimization of Automatic Centering Methods for Grinding
3.1 Analysis of Machining Allowance for Gear Shaper Cutter Blank
The machining allowance for gear shaper cutter blanks is analyzed, considering errors arising from indexing deviations and tooth surface errors. This analysis is essential for determining the optimal grinding path and minimizing material removal.
3.2 Calculation of Grinding Allowance
Based on the analysis of machining allowance, the grinding allowance is calculated to ensure efficient and precise material removal.
3.3 Optimization of Grinding Wheel Centering Method
Traditional centering methods rely on averaging the coordinates of tooth surfaces, which ignores the topological variations of the tooth surfaces. To improve accuracy, an optimized centering method is proposed, considering both tooth pitch errors and tooth surface deformations.
This method involves measuring the coordinates of tooth surfaces using a high-precision 3D probe installed on the grinding wheel carriage. The optimal position for the grinding wheel to enter the tooth slot is determined through coordinate transformation and calculation.
4. Implementation of Automatic Tool Setting Technology
4.1 Selection of Measurement System and CNC System
The selection of an appropriate measurement system and CNC system is crucial for the implementation of automatic tool setting technology. In this research, a Renishaw probe and a Siemens 828D CNC system are utilized.
4.2 Programming of CNC Code
The CNC code is programmed using Siemens’ advanced programming language to control the movement of the grinding wheel, diamond roller, and measuring probe. The code implements the optimized centering method and ensures precise tool setting.
Table 3: Functions of the CNC Code
| Function | Description |
|---|---|
| Control of Probe Movement | Controls the movement of the measuring probe |
| Coordinate Measurement and Saving | Measures and saves the coordinates of the gear shaper cutter |
| Automatic Centering and Allowance Calculation | Calculates the optimal centering position and grinding allowance |
4.3 Human-Machine Interface Development
An HMI is developed using Siemens’ Easy_Screen functionality to allow operators to input parameters and monitor the tool setting process. The interface is user-friendly and provides real-time feedback.
5. Experimental Results and Analysis
Experimental results demonstrate the effectiveness of the proposed automatic tool setting technology. Compared to traditional manual methods, the automatic tool setting technology significantly improves processing accuracy and efficiency.
Table 4: Comparison of Automatic and Manual Tool Setting Methods
| Method | Processing Accuracy | Efficiency | Operator Involvement |
|---|---|---|---|
| Manual | Lower | Lower | High |
| Automatic | Higher | Higher | Low |
6. Conclusion and Future Work
This thesis presents research on automatic tool setting technology for gear shaper cutters on special CNC grinding machines. By leveraging acoustic emission technology and optimized centering methods, the research has achieved significant improvements in processing accuracy and efficiency. Future work could focus on further refining the algorithms and exploring new technologies to enhance the performance of CNC grinding machines for gear shaper cutters.