MAHO 600 Horizontal Machining Center NC System Renewing And Improving

The MAHO 600 horizontal machining center is a second-handed equipment imported from the abroad in 1999, which is the product of MAHO corporation in Germany in the early 1980s. It is equipped with four close-loop controlled axis X, Y, Z and B, two pallets and a magazine of 24 tools , and can fulfill multiaspect machining just in one fixture at high machining precision and efficiency. For it plays an important role during machining the fuel assembly component parts, it is ranked the key equipment in our plant.Due to running for more than twenty years, there were many problems influenced the capability of production and the quality of product with the machining center, such as the ageing and wearing on electric parts and mechanical parts, which led up to a rising rate of the failure and halt. The rate of progress and the quality of product were influenced seriously. The main subsistent problems are the followings: Aging of electric part: The reliabilities of electric part were reduced gradually, these wereincreasing rate of failures for the CNC system. Comparative outdated control system: The integration level of electronic elements wasvery low., and the function was comparative outdated. Invalidation or wear of mechanic characteristic: Y axis ball-screw was damaged andfailure. There were some clearances on the guide rail. The hydraulic system was notvevry reliable. Other factors: long period of ordering spare parts and the high price, lack of technicaldocuments and so on.Despite all these, the horizontal machining center possesses some unique functions high precision and rigidity, and the most function parts are still in good conditions. It is more worthy of to be renewed and improved than to purchase a new one. Based on the analysis feasibility of renewing and improving, we made out a technical plan: To upgrade the CNC system from MAHO 432 to advanced FANUC OIMB. Adopted FANUC AC servo amplifiers and AC servo motors in stead of previous AC amplifiers and AC servo motors. HEIDENHAIN optical scale discharges from previous open PHILIPS optical scale. Replacing x, y, z axis ball-screws. To keep the original carbon brush for DC motor. The main renewing and improving works are constituted as the following: The selection of type for CNC system and servo system. To design the control system, the outer interface circuit and PMC program. To set the parameters for control system. To mount mechanical and electrical component parts. Repairing and adjusting mechanical and hydraulic component parts. Adjusting and commissioning the machine and performing an accepting inspection. To file the technical documents. After renewing and improving of the machine, the precision, the efficiency and the reliability meet the requirements of the fuel element machining, and the total cost of renewing and improving of the machine is less than one fourth of the price of the machine at the same level imported from abroad.