1. Introduction
In the realm of modern manufacturing, helical bevel gears play a crucial role in power transmission systems. Ensuring the precision and efficiency of gear manufacturing processes is of utmost importance. Among the various processes involved in gear production, tooth top chamfering is a critical step that enhances the gear’s performance and longevity. However, traditional manual chamfering methods are not only time-consuming but also prone to errors. To address these challenges, this paper presents a comprehensive approach to the secondary development of a helical bevel gear tooth top chamfering software using the FAGOR CNC8070-OL system.
1.1 Background and Significance
The increasing demand for high-quality gears in industries such as automotive, aerospace, and machinery has driven the need for advanced manufacturing techniques. Automated tooth top chamfering offers several advantages over manual methods, including improved consistency, reduced labor costs, and enhanced productivity. The FAGOR CNC8070-OL system, known for its robustness and flexibility, provides an ideal platform for developing customized solutions to meet these demands.
1.2 Objectives
The primary objective of this research is to develop a software solution that automates the tooth top chamfering process for helical bevel gears using the FAGOR CNC8070-OL system. The software should enable operators to input key parameters and generate optimized NC codes automatically, thereby streamlining the manufacturing process.
2. Theoretical Foundation
2.1 Tooth Top Chamfering Principles
Tooth top chamfering involves creating a beveled edge at the top of the gear tooth to improve meshing characteristics and reduce stress concentrations. The chamfering process requires precise calculation of the chamfer dimensions and tool paths based on the gear’s geometric parameters.
2.2 Key Parameters
Table 1 summarizes the key parameters involved in the tooth top chamfering process. These parameters include both geometric and operational factors that influence the chamfering outcome.
| Parameter | Description | Unit |
|---|---|---|
| Helical Angle | Angle of the helical teeth relative to the gear axis | Degrees |
| Module | Measure of the gear tooth size | mm |
| Number of Teeth (Pinion) | Number of teeth on the smaller gear | – |
| Number of Teeth (Gear) | Number of teeth on the larger gear | – |
| Face Width | Width of the gear face | mm |
| Pressure Angle | Angle at which the teeth exert force | Degrees |
| Cutter Radius | Radius of the cutting tool | mm |
| Chamfer Length | Desired length of the chamfer | mm |
3. Software Development Approach
3.1 Development Tools and Environment
The development of the helical bevel gear tooth top chamfering software utilized a combination of tools and technologies to ensure efficiency and compatibility with the FAGOR CNC8070-OL system.
3.1.1 Programming Languages
- VB.NET: Used for designing the user-friendly graphical user interface (GUI).
- C++: Employed for implementing the complex parameter calculation algorithms and generating NC codes.
3.1.2 Database Management
- Microsoft Access 2010: Served as the backend database to store and manage gear parameters, tool data, and generated NC codes.
3.1.3 Integration with FAGOR System
- FGUIM: FAGOR’s proprietary software development kit (SDK) was used to integrate the custom software with the CNC8070-OL system, enabling seamless communication and control.
3.2 Development 流程
The software development process was divided into several key phases, each contributing to the overall functionality and reliability of the system. Table 2 outlines the development phases and their respective tasks.
| Phase | Tasks | Tools/Techniques |
|---|---|---|
| Requirements Analysis | Identify user needs and system specifications | Interviews, surveys |
| Design | GUI layout design, algorithm development | VB.NET, C++ |
| Implementation | Coding and integration | Visual Studio 2015 |
| Testing | Validate functionality and performance | Simulation, error checking |
| Deployment | Install and integrate with FAGOR system | FGUIM |
4. Software Architecture
4.1 User Interface Design
The GUI was designed to be intuitive and user-friendly, allowing operators to input parameters and monitor the chamfering process with ease. Figure 1 illustrates the main interface components, including parameter input fields, status indicators, and control buttons.
4.2 Functional Modules
The software is composed of several functional modules, each performing specific tasks to facilitate the automated chamfering process. Table 3 describes these modules in detail.
| Module | Function |
|---|---|
| Parameter Input | Allows operators to enter gear, tool, and process parameters |
| Calculation Engine | Computes chamfer dimensions and tool paths based on input parameters |
| NC Code Generation | Generates optimized CNC codes for the chamfering process |
| Database Management | Stores and retrieves parameter data and NC codes |
| Simulation | Provides a virtual preview of the chamfering process |
5. Parameter Calculation Algorithms
5.1 Tooth Top
The tooth top chamfering process requires precise calculation of the chamfer path. The following equations were used to determine the chamfer geometry:
- Chamfer Length Calculation: \(L_{\theta} = r_{G} \sin \beta_{i} + \sqrt{r_{G}^{2} \sin^{2} \beta_{i} + L_{G}^{2} – 2 L_{G} r_{G} \sin \beta_{G}}\) Where:
- \(r_{G}\) is the radius of the gear.
- \(\beta_{i}\) is the helical angle.
- \(L_{G}\) is the face width.
- Tooth thickness adjustment factor: \(k = \text{Determined based on design guidelines and material properties}\)
5.2 Tool Path Generation
The tool path was generated using a combination of geometric transformations and kinematic calculations. The following steps were involved:
- Coordinate System Transformation: Convert gear geometry from the workpiece coordinate system to the machine tool coordinate system.
- Tool Positioning: Calculate the tool’s position and orientation to achieve the desired chamfer profile.
6. NC Code Generation
6.1 Code Structure
The generated NC codes follow the FAGOR CNC8070-OL system’s programming syntax. Table 4 provides an example of the NC code structure for a typical chamfering operation.
| Code | Description |
|---|---|
| G01 | Linear interpolation |
| X, Y, Z | Coordinates for tool movement |
| F | Feed rate |
| S | Spindle speed |
6.2 Optimization Techniques
To ensure efficient machining, the NC codes were optimized using the following techniques:
- Tool Path Optimization: Minimize redundant movements and maximize cutting efficiency.
- Feed Rate Adjustment: Adjust the feed rate based on material properties and tool wear.
7. Simulation and Validation
7.1 Simulation Setup
The developed software was integrated with VERICUT, a leading CNC simulation software, to validate the generated NC codes. Figure 2 shows the simulation environment setup, including the gear model, tool, and machine tool configuration.
7.2 Results and Analysis
The simulation results were analyzed to evaluate the chamfer quality and process accuracy. Table 5 summarizes the key simulation results, including chamfer length, surface finish, and dimensional accuracy.
| Parameter | Target Value | Simulation Result | Deviation |
|---|---|---|---|
| Chamfer Length | 2.0 mm | 1.98 mm | -0.02 mm |
| Surface Finish | Ra 0.8 μm | Ra 0.85 μm | +0.05 μm |
| Dimensional Accuracy | ±0.05 mm | ±0.04 mm | Within tolerance |
8. Conclusion
The development of the helical bevel gear tooth top chamfering software based on the FAGOR CNC8070-OL system represents a significant advancement in automated gear manufacturing. The software enables operators to input parameters and generate optimized NC codes, reducing manual errors and improving productivity. The simulation results demonstrate the software’s effectiveness in achieving high-quality chamfering with minimal deviations from the target specifications.
