Analysis of soft failure of CNC machine tools

Analysis of soft failure of CNC machine tools

The soft faults of CNC machine tools can basically be divided into two categories:

The first category is caused by the machine parameter problems in the NC system (sometimes due to improper settings, sometimes due to accidental parameter changes or confusion). For such soft faults, as long as the parameters are adjusted, the fault will naturally disappear.

The second type of soft fault is generally caused by accidental reasons that the NC system is in an infinite loop. For such failures, the system can generally be restored by forced resetting and restarting.

Two examples are used to illustrate:

1. For a CNC lathe with FANUC-OT system, a crash occurs every time the CNC machine is turned on, and any commands cannot be operated normally. After that, the method of forced reset is adopted. After all the system memory is cleared, the system returns to normal. After re-entering the machine parameters and programs, the machine tool is used normally. This fault is caused by the confusion of machine parameters.

2. A special CNC milling machine, Siemens CNC system, the CNC system displays the alarm "LIMITSWITCH" during batch processing. This failure is caused by the Y-axis stroke exceeding the limit value set by the software. Check that the program value has not changed. After careful observation of the fault phenomenon, when a fault occurs, the displayed Y-axis coordinate is determined to reach the software limit. After careful study, it is found that the compensation value input becomes larger. After the software limit setting is adjusted appropriately, the fault is eliminated. This fault is caused by improper setting of the limit parameters of the CNC machine tool software.