Transforming 4.5×17m Gantry Milling And Boring Machine With Siemens 840D CNC System

4.5x17m gantry milling and boring machine is an used CNC machine tool which we imported from America, because of a long time nonuse, the original CNC system and drive device had been affected with damp, it has so many faults after installation, besides many of its spare parts had washed out, so it had many difficulties for maintaining. But, on the basis of its high mechanical precision, transforming the electric system with lesser-cost can obtains the same function as new equipment.The thesis discusses about the electric transformation of 4.5x17m, one large-sized numerical controlled milling and boring machine, First of all, I analyze the status of mechine before transforming, illuminate the transforming reasons, and confirm the electric transforming scheme, that is, adopte SINUMERIK 840D system and SIMODRIVE 611D digital AC servo drive system produced by German SIEMENS, to achieve the feed movement of X axis(worktable move),Y axis(spindle box level move),Z1/Z2(sliding pillow portrait move),W1/W2(beam rise and fall),B axis(adjunct milling head angle deflexion), C axis(milling head disparting degree rotation), SU axis(adjunct dolly move), I adopt SIEMENS 6RA70 DC timing equipment drive for spindle rotation. SIEMENS 840D system adopts building block and modularization structure, by illuminating the hardware configuration and interface design of transformation, we can know that the key point of transforming machine successfully is setting up a reasonable CNC system.Secondly, I detailedly introduces and explains the scheme,hardware configuration,machine parameters setting, PLC programme structure,servodrive,spindle drive of transforming machine with Siemens 840D CNC system, especially focuses on the difficulties: achieving Analog Axis function,Gantry Axis function, mater-slave controlled function of double motors, automatic close-start and parameters switch of B axis on the same machine. By researching and practising these functions, I largely improved technical level of CNC machine tool transformation and settled the key technical problem. After transforming, its general theoretical and technical level and engineering practising competence has achieved advanced level of CNC technology application in our country.At last, I summerize the effect of machine tool transformation, and educe a conclusion that CNC transformation of machine tool is the strategic means of one corporation developing for long.