Best use of machine tool diagnosis function

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Make good use of the machine tool diagnosis function

-- two cases of ge-fanuc peripheral fault maintenance

fanuc system I series products are equipped with more powerful diagnosis function and operation information display function than OM, OT and other products, which brings great convenience to the use and maintenance of machine tool users. According to the operation information displayed by the system, PMC soft relay and i/0 status, the peripheral faults of the system can be easily found, which greatly shortens the time to find the cause of the fault

1 example 1

a vertical movable column high-speed machining center made in Germany is equipped with GE Fanuc 21i system. In addition to x-axis, y-axis, Z-axis and main axis, it is also equipped with a fourth axis and a fifth axis. The fast-moving speed of the machine tool is 60m/min, and the cutting feed speed is more than 2.4m/min. The tool can be changed at any point, and the tool change time is less than 1s. The machining efficiency is sevenoreight times that of the ordinary machining center, which is praised by insiders

however, after the self delivery and acceptance of the machine tool, the information that the fifth axis is not clamped occasionally appears in the processing, causing the feed to stop. After deleting the information, the processing can continue, and the frequency of occurrence gradually increases from once a day to several times a day. Later, this information turns into an alarm. Press R to specify that the friction coefficient is 1 value, and then the ESET key can be eliminated. The program needs to be re executed from the interruption point before continuing processing. This fault has seriously affected the normal production. The four and five axes of the machine tool are hydraulic locking type, which is relaxed when rotating, and the performance index is very poor. It is locked when processing. Through maintenance, it is found that the normally open point of the replaceable contact combination is not open smoothly. After replacing this contact combination, start the machine for test and troubleshooting

in this example, the system and PMC operate well, and the sensing elements and actuating elements operate normally. Due to poor relay quality and contact adhesion, the stability requirements of DC24V direct matching are very high. It is connected to the solenoid valve coil without being controlled by the system, resulting in failure. It is from the machine tool diagnostic information, combined with the PMC i/0 status, that the problem is found and the faulty device is found

2 cases 2

the same as the above machine tool, the oil pressure motor overtemperature alarm occurs during processing, NC stops, and power stops. The machine tool is equipped with a hydraulic system of a German company. The oil pressure tank, oil pump and motor are integrated together. The total volume is not more than 20L, the energy accumulator is 0.040l, and the working pressure is 21MPa. Through inspection, it was suspected that there was a problem with the air tight detection device, and the two detection devices were exchanged. The fault was found in the other fixture, which was confirmed to be a quality defect of the air tight detection device. Replace with new products and troubleshoot

in this example, the surface fault is the overtemperature of the oil pressure motor. Due to many automatic functions set by the machine tool, the cause is that the poor detection devices lead to the continuous clamping and loosening of the machine tool fixture, resulting in the frequent startup of the oil pump motor and overheating. This requires the maintenance personnel to comprehensively analyze the root cause according to the information displayed by the machine tool and the actual working principle, combined with the PMC status, so as to find the crux of the fault and finally solve the problem

3 conclusion

the continuous development of CNC system makes the system function further expanded, the operation more stable, and provides a broader space for end users. The perfect system can only play its role if it is complemented by the reliable assembly quality and parts quality of the machine tool manufacturer. Poor assembly quality and parts quality will make a fireman's coat lighter, safer and cheaper, and a beautiful machine tool is inferior. I think this is the last sentence of this article

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