Anti-jamming measures for CNC machine tools - Solutions - Huaqiang

Single chip microcomputer STM32L151CCU6

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Improving the stability of CNC machine tools is crucial for ensuring consistent and accurate processing results. One of the main challenges during operation is the risk of external signal interference, which can disrupt the machine's performance. To address this, several anti-interference measures are implemented to ensure the system functions reliably and smoothly. As CNC technology continues to evolve, these machines have become a staple in many industrial settings. However, their stability during operation remains a critical concern, especially when it comes to managing interference during the design and manufacturing stages. Many users encounter unexpected alarms or erratic behavior, which often aren't clearly explained in the manufacturer's manuals. These issues can be random, with varying alarm numbers or intermittent problems that make troubleshooting difficult. After extensive discussions with manufacturers and real-world experience, it was found that over 90% of such issues stem from poor electrical cabinet design. This includes improper grounding, messy wiring, and inadequate shielding, all of which contribute to system instability. There are three main types of noise that can interfere with CNC systems: 1. **Conductive Noise**: Generated by devices like servo amplifiers, this type of noise travels through power lines and affects connected equipment. 2. **Radiated Noise**: Emitted by electrical components, this noise spreads through the air and can impact nearby devices. 3. **Induced Noise**: Caused by proximity between cables, leading to electromagnetic coupling and signal distortion. To minimize these effects, several key anti-interference strategies are recommended: - Install the control system, including the servo amplifier and spindle drive, inside a sealed metal cabinet. - Separate signal and power lines, and route them close to the metal walls of the cabinet. - Use shielded cables for signal lines, and ensure proper grounding of the shields. - Ground all controllers, amplifiers, and conductive components. - Add filters and surge absorbers at the power input to reduce noise and protect against voltage spikes. - Use AC reactors and circuit breakers with leakage protection for added safety. The power supply for the CNC controller should be carefully selected. It must have sufficient capacity, stable output, and minimal voltage fluctuation. For example, FANUC controllers typically use 24V DC power supplies, and it's important to account for the total load, including the MDI keyboard and display units. Grounding is also essential. There are three main types of grounding: signal ground (SG), chassis ground (FG), and system ground (SG). Each has its own purpose, and proper implementation ensures both safety and performance. In the electrical cabinet, high-power and low-power signal lines must be separated to prevent interference. Shielded cables are required for weak signals, and grounding plates should be used to manage the connections effectively. The machine tool cabinet itself should be made of metal and fully enclosed. Proper welding, minimal openings, and conductive gaskets on doors help maintain electromagnetic isolation. A well-designed cabinet not only protects internal components but also prevents interference from spreading to other equipment. In summary, the stability of CNC machines is vital for the future of mechanical manufacturing. Implementing effective anti-interference measures significantly enhances machine reliability and has a lasting impact on the industry.