Typical Fault Analysis of Numerical Control System
1 Introduction
Numerical Control (NC) system is an automatic control system widely used in various machineries and equipment and is extensively used in CNC machine tools and other precision production equipment. Its application not only saves a lot of manpower and energy, but also improves work efficiency and product quality. However, due to complex mechanical and electrical parts, related electronic circuits and software, etc., if it is not operated correctly, it is easy to cause various faults. In this paper, we will analyze the common faults of NC system and give the corresponding solutions.
2 Typical Faults and Analysis
2.1 Inverter Motor Protection Fault
This problem is caused by an alarm such as overcurrent, overload, or over voltage on the inverter. Over-current alarm generally occurs when the internal components of the inverter do not match the load required by the motor and the motor blackens, affecting the heat dissipation of the inverter, causing the inverter over-current protection. If the load requirement of the motor and the internal set of the inverter are not matched, the electrical parameters of the motor will be changed and the motor will be over-loaded, which will cause the inverter over-load protection. If the load impedance of the motor is very low, the power supply voltage of the inverter will be increased, which will cause the inverter over-voltage protection. The solution of this problem is to adjust the inverter and motor parameters to match.
2.2 Motor abnormal sound
When the motor is abnormal sound, the mechanical parts of the motor, the bearing and the bearing parts are the first to be checked, including the tightness of the bearing, the outer bracket of the bearing and the cleanliness of the bearing. If the fault is in the mechanical parts, it should be adjusted or repaired according to the fault condition. If the mechanical parts are normal, the power supply of the motor should be checked. Inappropriate voltage and frequency of the power supply will cause the motor sound to be abnormal. As long as adjust the voltage and frequency can solve the problem.
2.3 Program Error
Program error is caused by incorrect program execution. The most common problem is that the command order of the program is wrong, the program formula is inaccurate or the number of parts is entered wrong. Therefore, the program needs to be checked carefully, the formula needs to be reset, and the number of parts needs to be entered correctly.
2.4 Sensor malfunction
Sensor malfunction can be caused by incorrect sensor connection, incorrect connection of shielding wire and ground wire, etc. If the sensor works in an unauthorized environment for a long time, it will also affect its normal operation. Therefore, always check the connection state of sensors, whether it is powered correctly, whether there is interference, and if necessary, the sensor should be replaced.
2.5 CNC machine tool does not follow the command
If the CNC machine tool does not move according to the command, first check the connection of the control system cable and the control system board, and whether there is a loose connection. Generally, if the connection is normal, it means that there may be a problem with the parameter setting. Therefore, you can reset the parameters of the CNC machine tool and the parameter of the connected motor to make them compatible.
3 Conclusion
In summary, the common faults of NC system can also be classified according to their causes, such as power supply faults, transmission faults, mechanical equipment faults, program errors and sensor malfunctions, etc. The specific measures of troubleshooting should be taken according to the specific causes. It is necessary to understand the working principle of the system and combine with the actual operation to find the solution quickly. As long as the problem is found in time, remedy the problem in time, the system can work normally, improve work efficiency and product quality.
