Common fault analysis and solution of CNC cutting machine

At present, the application of CNC cutting machine is more and more extensive, its processing flexibility is good, high precision, high production efficiency, with many advantages. However, because the technology is more and more advanced, complex, the quality of maintenance personnel requirements are very high, they are required to have a deeper professional knowledge and rich maintenance experience, in the CNC cutting machine failure can be eliminated in a timely manner. Through the analysis and treatment of faults, some experience has been obtained. The following combined with some typical examples, the numerical control cutting machine failure system analysis for reference.

First, NC system failure

1. Hardware failure
Sometimes the machine is shut down due to hardware damage to the CNC system. For the diagnosis of such faults, we must first understand the working principle of the numerical control system and the function of each circuit board, and then analyze according to the fault phenomenon, and use the exchange method to accurately locate the fault point under conditions.
2. Soft fault
Some faults in CNC cutters are caused by NC system parameters, sometimes due to improper settings, sometimes due to accidental changes or confusion of parameters, such faults as long as the adjustment of parameters, it will naturally disappear. There are also some failures due to accidental reasons to the NC system in a dead cycle state, such failures sometimes must be forced to start the method to restore the use of the system.

Second, the failure of the servo system
Because the control core of the numerical control system is the digital control of the feed part of the cutting machine, and the feed is controlled by the servo unit servo motor, driving the ball screw to achieve, by the rotary encoder to do the position feedback element, forming a semi-closed loop position control system. Therefore, the role of servo system in CNC machine tools is quite important. The failure of the servo system is generally caused by problems such as servo control unit, servo motor, speed measurement motor, encoder, etc. There are many situations that cause these problems, gear boxes stuck, gear rackbites wrong, track rust, and so on.

Third, external fault
Due to the increasing reliability of modern CNC systems, the failure rate is getting lower and lower, and few failures occur. Most of the failures are non-system failures and are caused by external causes.
Remind customers that finding a problem is the first and most important step in solving the problem. Especially for the external fault of cnc cutting machine, sometimes the diagnosis process is more complex, once the problem is found, it is easier to solve. On the diagnosis of external faults, we summarize two lessons, first of all, we should master the working principle and action sequence of CNC cutting machine. Secondly, to be skilled in the use of the plc ladder provided by the factory, the use of NC system status display function or the use of off-machine programmer to monitor the operation status of PLC, according to the ladder chain relationship, to determine the point of failure, as long as the above two points, the general numerical control cutting machine external fault, will be promptly eliminated.