CNC machine tools have incomparable advantages in processing accuracy, automation, production efficiency, labor intensity and other aspects compared with ordinary machine tools. However, the cost of purchasing new CNC machine tools, especially large CNC machine tools, is very high, which often makes many users shy, especially in developing countries such as China, where funds are limited. Therefore, most machinery factories want to buy but cannot afford CNC machine tools. How to obtain CNC machine tools with less investment is a problem worthy of discussion. Can we upgrade the original machine tool without buying a new CNC machine tool to make it a CNC machine tool? The answer is yes. The experience of upgrading and transformation in recent years tells us that this is promising. It not only has good practical performance, short cycle, but also can save a lot of money. The larger the machine tool being transformed, the more money will be saved.

Design and manufacture the electric control system of the machine tool. Fanuc 0it CNC system is selected; Fanuc AC digital servo motor is selected; Select domestic joint-venture low-voltage electric control components; Design and develop machine tool control logic diagram.

Finally, the electromechanical joint commissioning of the machine tool. Adjust the X axis and Z axis of the machine tool; Adjust the geometric accuracy of the machine tool; Adjust the coordinate accuracy of the machine tool, and use the dual-frequency laser to detect the accuracy of each axis. Carry out the auxiliary function commissioning of the machine tool and continuously idle the machine tool for 36 hours.

After transformation, the performance of the machine tool is stable and reliable. After more than one year of production verification, it meets the transformation requirements. The transformation cost of 1 million yuan is only 1/15 of the purchase of new CNC machine tools, saving a lot of money for users. The machine tool has contributed a lot to the production of spiral case in hydropower equipment of the plant, creating tens of millions of yuan of output value.

Problems needing attention in the upgrading of numerical control

What kind of machine tool is suitable for CNC upgrading and remanufacturing? Experience has proved that the transformation effect of vertical and horizontal lathes (especially large vertical and horizontal lathes), gantry milling upgrading CNC gantry milling, gantry planer upgrading CNC gantry milling, horizontal boring and milling machine upgrading CNC horizontal boring and milling machine, vertical and horizontal grinding machine upgrading CNC grinding machine is relatively ideal.

CNC upgrading and transformation must first redesign and remanufacture the mechanical part of the machine tool to meet the requirements of CNC. Simply adding servo motor and numerical control system cannot achieve the purpose of upgrading, so the following work should be done generally:

Replace the original trapezoidal lead screw with ball screw to improve accuracy and reduce friction; Grind, scrape and grind the guide rail and paste plastic or directly use linear rolling guide rail; Refine the spindle system to improve spindle accuracy; Design automatic cooling and chip removal system to improve the degree of machine tool automation; Add tool change mechanism - tool magazine manipulator if necessary; Design and manufacture automatic lubrication system.

The numerical control system and servo system should be determined and selected during the transformation. The more functions of the CNC system is not the better, and the more functions of the system are generally more expensive. Domestic system and imported system shall be selected according to needs. It should be acknowledged that there is still a gap between the domestic system and the imported system, and the imported system is generally preferred for large high-precision equipment. However, in recent years, the domestic system has made great progress and can be used reliably for general lathes and milling machines. The AC servo motor should be selected first.

The choice of remanufacturing CNC upgrading contractor is also very important. To select qualified companies, the current remanufacturing industry is still very non-standard. The asking prices of different companies for the transformation of the same machine tool vary greatly, sometimes as much as 2-3 times; The existing performance of the contracting company shall be surveyed; If you want to go to the contracting company for on-site inspection, those companies that do not have a fixed site and a stable technical team will not be able to manufacture again. A good remanufacturing enterprise should have strong mechanical and electrical design capabilities and certain processing and manufacturing capabilities.