(1) The initial reset method is usually used to eliminate system alarms caused by transient faults. Hardware reset or switch system power supply, troubleshooting can be done in sequence. If the system operation storage area is chaotic due to power failure, circuit board or battery undervoltage, the system needs to be initialized and eliminated. Before elimination, duplicate data must be recorded. If the fault still exists after initialization, the system needs to be eliminated. If it cannot be cleared, it will be diagnosed by hardware.
(2) Parameter changes, program execution system parameters are the basis for determining system functions, parameter setting failures may result in system failures or failures of certain functions. For example, on a rotor milling machine in Harbin, the measurement cycle system was selected. This function requires scene memory. During debugging, it was found that this function could not be completed. The view finds that the data bits in the scene memory are not set, and the function is normal after setting. Sometimes the failure of the user program will cause the failure to stop, so you can select the block search function of the system to check, correct all errors, and ensure its normal operation.
(3) Adjustment. The optimal adjustment method is the simplest and most feasible method. After adjusting the potentiometer, the system failure was corrected. For example, during the maintenance process of a military factory, the screen of its system display device was chaotic, and it was normal after adjustment. In a factory in Shandong Province, belt slippage occurred when the spindle was started and braked. The main reason is that the load torque of the main shaft is large, and the tilting and lifting time of the driving equipment is too short, which is normal after adjustment.
Optimal adjustment is a system induction method for optimal matching between the servo drive system and the driven mechanical system. The method is very simple. It uses a multi-line recorder or a dual tracker oscilloscope with storage function to separate the echo connection between the survey command and the speed response or current response. By adjusting the sharing coefficient and integral time of the speed regulator, the servo system has a higher dynamic response characteristic and an optimal operating state without vibration. In the absence of an oscilloscope or recorder, based on experience, adjust the motor to vibrate, and then gradually adjust to the opposite direction until the vibration is eliminated.
(4) The replacement method of spare parts is to replace the circuit board that has been diagnosed as damaged with good spare parts, and carry out corresponding initialization, so that the machine tool can be quickly put into normal operation, and then repair or repair the damaged circuit board. This is the most common way to eliminate faults.
(5) Current methods to improve power quality usually use voltage stabilized power supplies to improve power oscillations. For high-frequency interference, capacitor filtering can be used to reduce the defects of the power supply board through these preventive measures.
(6) In order to repair accidental defects caused by planning defects in practice, some large-scale production companies continue to modify and improve system software and hardware. These modifications are continuously provided to maintainable personnel through maintenance information. It can be used as a basis to eliminate defects, accurately and completely eliminate defects.
3.4 Maintenance precautions
(1) When removing the circuit board from the entire machine, carefully record the corresponding direction, the number of the connecting cable, and the corresponding pressing parts and screws. When removing the pressing parts and screws, they should be placed in a special box to avoid throwing them away. After the installation, everything in the box should be used, otherwise the installation will be incomplete.
(2) The electric soldering iron should be placed in front of the hand, and the circuit board should be repaired separately. In order to adapt to the welding of integrated circuits and avoid damaging other components during the welding process, the welding head must be properly calibrated.
(3) When measuring the resistance between lines, the power supply should be cut off. When measuring the resistance, the red and black pens should be exchanged for two measurements, taking the larger resistance as the reference value.
(4) Most of the circuit boards are painted with solder mask, so the corresponding solder joints should be found as test points in the measurement. Do not remove the solder film. Some circuit boards have all the edge layers brushed, as long as the edge layer is scraped off with a knife edge at the solder joints.
(5) The printed circuit shall not be blocked at will. Some repair work has certain repair experience for the house
Fundamental conditions for repairing modern numerical control systems
Basic conditions for maintenance workers
The quality of the repair work mainly depends on the conditions of the employees. It is necessary for the maintenance personnel to make the following requirements:
(1) Have a high sense of responsibility and good professional ethics;
(2) Having a wide range of common sense, basic computer knowledge, analog and digital circuits, active control and dragging of motors, viewing skills and mechanical processing skills, and a certain level of foreign language;
(3) After excellent skills training, master the working principles of CNC, transmission, and PLC, and master CNC programming and programming languages;
(4) Understand the organizational structure, have experimental skills and strong operational capabilities;
(5) Master various commonly used (especially on-site) test instruments, appearance and various items.
Maintenance technical conditions
(1) Prepare common spare parts and accessories;
(2) Being able to obtain practical assistance or supply of microelectronic components at any time;
(3) Make necessary repairs to things, instruments, shapes, circuits, and computers. Optimize the small program system or programmer to assist in equipment debugging;
(4) Complete materials, manuals, circuit diagrams, maintenance manuals (including CNC operation manuals) and interfaces, adjustment and diagnosis, driver manuals, PLC manuals (including PLC user program tables), meta-equipment tables, etc.