Commissioning of CNC machine tools

1. Accuracy adjustment of CNC machine tools

The level and geometric accuracy of the machine bed must be precisely adjusted, when adjusting the accuracy of a CNC machine tool, use anchor bolts and adjustable pads to finely adjust the level of the machine bed on the solidified machine tool foundation; for ordinary machine tools, the reading of the level should not exceed 0.04mm/1000mm; for high-precision machine tools, the reading of the level should not exceed 0.02mm/ 1000mm. After adjusting, move the movable parts on the bed body (such as column, bed saddle and work table, etc.), observe and record the changes in the level of the machine tool within the full stroke of each coordinate moved, and adjust the corresponding geometric accuracy of the machine tool to reach the allowable tolerance range. The bed of a small machine tool is mostly one-piece, with good rigidity and relatively easy to adjust. Large and medium-sized machine tools need to have more pad supports due to their large bed size. In order not to cause additional distortion of the bed, it is required to adjust the horizontal bed in a free state of the bed. After all the support pads are fully supported, then tighten the anchor bolts. In this way, the stability of the long-term work after fine adjustment of the bed can be maintained, and the maintenance of geometric accuracy can be improved. Generally, the machine tool is tested for accuracy before leaving the factory. As long as the machine quality is stable and the user adjusts according to the above requirements, the machine tool can reach the accuracy before leaving the factory.

2. Functional debugging of machine tools

The functional debugging of the machine tool is the process of checking and testing the various functions of the machine tool after adjustment. Before debugging, it is necessary to check whether the setting parameters of the CNC system and programmable controller of the machine tool are consistent with the data in the random table, then test the main operating functions, safety measures, running strokes and the execution of common instructions, such as manual operation mode, jog mode, editing mode (EDIT), data input mode (MDI), automatic operation mode (MEMOTY), and limit protection of travel. (software and hardware protection), the spindle gear shift command and the speed command at all levels are correct. Finally, check whether the auxiliary functions and accessories of the machine tool are working properly, such as check whether the machine lighting, cooling guard and various guards are complete; after filling up the cutting fluid, check whether the nozzle in the box can spray cutting fluid; whether the cooling shield is exposed when used; whether the chip remover can work normally; whether the thermostat of the spindle box works, and whether the selected tool management function  and contact probe can work normally. For CNC machining centers with tool magazines, the position of the manipulator should also be adjusted. While adjusting, get the machine tool automatically run to the tool exchange position, adjust the position of the tool loading machine and the tool unloading manipulator relative to the spindle by manual operation, after adjustment, tighten the adjustment screw and the foundation screw of the tool magazine, then mount a number of tool holders with the quality same as the allowable quality, and perform several times of automatic exchange from the tool magazine to the  spindle position , and take the correct movement of no bump and knife drop as qualified inspection.

3. Machine test run

After each installation and commissioning of the machine tool, the whole machine must be automatically run for a period of time with a certain load as a fully check to test the machine function and reliability of the workpiece. The operating time is generally 8 hours a day, lasting for 2 to 3 days, or 24 hours continuous operation for 1 to 2 days. This process is called a trial run after installation. The program used in the trial operation is called the test machine program, and the test machine program used by the machine tool factory for debugging time can be directly used, or the test machine program can be self-compiled. The test program should include: the main functions of the CNC system (such as movement in each coordinate direction, linear interpolation and circular interpolation, etc. ), covering the automatic replacement of 2/3 of the tools in the tool magazine; test with the highest, lowest and common speed in the spindle, meanwhile take the tools feed at fast and common speed; automatic exchange of worktables, use of main M commands, macro programs, measurement programs, etc.

During trial operation, the tool magazine of the machine tool should be filled with tool holders, and the quality of the tool holders should meet the specified quality; certain load should be loaded on the exchange table. While trial, except for the faults caused by operating errors, no machine tool failures are allowed, otherwise it means that there must be a problem in the installation and commissioning of the machine tool.

For some small CNC machine tools, such as small and economical CNC machine tools, they can be directly installed. As long as the horizontal bed of the machine tool is debugged, the geometric accuracy is qualified; it can be put into operation after power-on and test run.