| As the development of the country’s manufacturing industry,CNC technology has been widely used around the whole nation, meanwhile, in order to meet the new requirement under the new situation, upgrading the older CNC equipment has to be put into schedule in various manufacturers. 15-PF CNC gantry milling was imported by Hangzhou Steam Turbine Co, Ltd. from Germany WALDRICH- Kebao. The old machine’s Electrical Control System was Siemens 810 M, while its function and operating platform of the CNC system has been unable to meet the requirements of turbine parts processing. After many years operation, the aging components SIMODRIVE 611 A analog drive board and DC drive motor has been repaired many times and no spare parts can be changed, the maintenance cost much and time-consuming. Due to the mechanical part ram and slide mobile reference guide has been badly worn, the precision has been reduced, down tool phenomenon when ram movement, has seriously affected the production.As this machine is the company’s main CNC equipment, and the construction and rigidity are very good for heavy chip. By considering the technically and economically feasibility, this paper identified the following programs according to its problem and characteristics:1. To grind the crossbeam rail and ram. Replace the ball screw of the Y-axis(horizontal movement of the headstock) and the Z-axis(vertical ram movement). And increase Z-axis balance cylinder to prevent falling tools.2. To use Siemens SINUMERIK 840 D CNC system and SIMODRIVE 6llD digital AC servo drive to replace the original CNC system and drive, to improve the system stability. Main spindle and feed axes were used 1PH7 series AC induction motor and 1TF6 AC servo motor to replace the original DC motor, to realize highprecision and high response moves.3. To do the detailed description and explanation on Siemens SINUMERIK840 D CNC from hardware selection, communication interface designing, PLC programming designing, the drivers and axis parameter settings.4. To introduce the debugging and optimization of 840 D CNC system by three parts: optimization the servo axis running, pitch compensation and over quadrant compensation.The system data backup at last..All the problems have been solved after the upgrading, and the alarm diagnostic system and the machine has been well improved. The precision and productivity has also been significantly upgraded. It saved lots of money for the factory. Besides, this experience can also be used in the similar old CNC equipment, which not only saves money but also upgrade the technology. |
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