1, X-axis is not automatically return to the reference point moves
The machine tools for production of a research institute of JCS - 018 vertical machining centers, CNC system for FANUC - BESK7M. After the failure to check on the CRT without warning suggested that the machine is not part of the police instructions. But the manual to mobile X-axis, X-axis with reference point moved manually, machine can carry out normal processing, and then repeat the process to complete the phenomenon.

According to the above we judge: NC system, servo system fault-free. Consider the fault occurred in the X-axis reference point to the process of suspected fault with the X axis reference point for the change in the parameters, however, when we TE mode, will address the F and X-axis reference point for the transfer of a check, but found that these parameters were normal.

CNC machine tools from the working principle, we can see that apart from the axis point of reference parameters, but also to the basics - axis location, the location reference point. Check on the X-axis machine tools to limit switch reference point, because it has found oil and breakdowns, which is always in a state of access. When processing is completed, the system will have to think a reference point, therefore, there is no X-axis reference point to return to action. The trip switch cleaning, repairing, troubleshooting.

2, automatic processing, A, B table without exchange movements

Hungary machine for the production of MKC-500 horizontal machining center, CNC system SIEMENS820M. When the fault occurs when the machine has been implemented procedures End of M06 plug subroutine functions, shutter curtain open, but A, B table without exchange movements, procedures in the state to stop, and NC systems showed no alarm.

From the machine table can be seen exchanging flow chart: When A, B table exchange, two conditions must be met: First, to open the shutter curtain; Table 2 is a relaxed state and should be raised. Check the above two conditions: (a) shutter curtain open, to meet the conditions. (2) Workbench not rising, conditions satisfied, still in the stage clamping state. The machine instruction manual to know: rotary table and relax are clamping pressure relay with the SP03 and SP03 pressure corresponding to the relay point for the importation of E9.0 PLC. When the machine is now in a normal state of processing, rotating table was clamping, E9.0 = 1; When the state machine in the exchange, rotating table to relax, E9.0 = 0, preparing for A, B table exchange. In accordance with its principles, to make workbenches exchange, subject to E9.0 = 0, workbenches relax, even SP03 pressure relay disconnected.

We found SP03 pressure relay failure caused by oil pollution. Its cleansing repair, adjustment to the exchange table, E9.0 = 0; Table processing, E9.0 = 1. Troubleshooting.

3, in the automatic processing Manipulator not ATC

The machine for the production of a research institute KT1400 vertical machining centers, CNC system FANUC0 system. Inspections found that the manipulator control mode is not ATC, no alarm. In manual mode to ATC, ATC can continue after automatic processing.

According to the inspection, we judge NC system, servo system no fault. Taking into account the electrical and mechanical knife hand movements by Fujitsu separate inverter control, it will check the focus on the inverter. State of the manual tool change and the knife moves are accurate. State of automatic, the rotary knife normal, but not normal ATC. Check NC control signal has been issued, and control contactor has a suction that ATC signal has been sent converter. Inverter inspection work, ATC found in the manual, their frequency of pressures, in its automatic tool change when only 2 Hz frequency. In such a low frequency, the manipulator of course, unable to perform normal ATC action. Study the reasons for its failure to Manipulator is ATC, a sudden loss of power substation, causing ATC card manipulator when dead, restore power, the fault will be a re-setting the frequency N., troubleshooting, mechanical hand back to normal.

4, rotating stage in the process of rotating movements or, in odd position correct, even positioning closed

Machine fault with the system as described in 2. After the failure, machine without any warning, not positioning, machine unable to work, but will re-table after the first landing, and the correct positioning, machine tools can continue to work. According to the fault phenomena, we doubt is the revolving stage motor on the rotary encoder or loosening caused by the closed position. But repeated regulatory changes and rotary encoder with the rotary encoder parameters are not troubleshooting.

The drive system with the knife the same motor drive system, we are using the replacement of the exchange. When the knife drive system for the rotary table, the failure to eliminate. While table-driven system for rotation to the knife, the knife is a knife, no correct the fault. Through this examination, we determined table-driven system failure. The drive system for SIMODRIVE611-A feed-driven devices. Through access to the drive system and the manual drive system failure analysis, it was agreed that: the device driver without hardware failure. The fault occurred mainly due to the long run after mechanical wear parts, electrical components of the reasons for the changes caused by servo drive system and the mechanical system is not achieved by the best match. The information technology know: This controller can regulate the speed ratio coefficient KP TN and integration time, the servo system to achieve both high dynamic response characteristics, but not the best working state oscillation. Our reference knife motor driven device for the calibration and KP TN scale rotary table right drive system for fine-tuning, fault can be ruled out.

No fault in the alarm failure CNC a larger proportion. Trouble is usually due to the formation of the supply voltage, hydraulic, pneumatic, oil, environmental temperature and the impact of external conditions. As described in this paper 1,2,3 fault. In addition, the use of CNC machine tools in a longer time, because the aging of components, mechanical parts wear, and mechanical systems will also match part of the problems, resulting in the formation of fault alarm, as described in this paper, four fault. Therefore, the use of CNC machine tools to the environment, strengthen the CNC maintenance, fault alarm is to reduce the incidence of the fundamental way is to ensure the normal work of the NC Machine important means.