The Geometric And Thermal-induced Space Error Detection And Identification Of Key Functional Components

The accuracy of NC Machine reflects the performance of NC Machine. There are two methods of improving the accuracy of NC Machine, one is to further optimize the NC Machine’s structure, while the other one is to detect and compensate the space error of NC Machine effectively and accurately. Apparently, the second method is the faster to improve the accuracy of NC Machine, comparing with the first method’s high cost and time-consuming. Combining with the national science and technology major project-Precision Horizontal Machining Center Technology Innovation Platform" (Project No.:2012ZX04012-031), this paper takes the key components of multi axial NC Machine as the research object to develop a serials of studies on the space error detection and distinguishing of NC Machine, offering basis for the error compensation.Based on the first comprehensive review of domestic and overseas theory and results of NC Machine space error, this paper proceeds study for below aspects:(1)On the basis of introducing the definition of NC Machine space error and integrated space error sources, the paper determines the main contents of the research in this paper are the geometric error and thermal-induced space error of NC Machine.(2)The paper analyzes the geometric error theory of NC Machine center—— rotary table, put forwards to using several different installation methods of ball bar to measure five error parameters of rotary table in its progress, detects and tests the NC Machine center rotary table by using the way to test the last error parameter of rotary table combining with laser interferometer and rotary indexing instrument, finally by combining the correspongding algebraic operation identify the six geometric errors of rotary table.(3)The different working conditions of the spindle are designed through the analysis of the milling head test bench spindle thermal error parameters based on international standardISO230-3. The paper tests the thermal error parameters under the different working conditions of the spindle by using five point method, then processed simple analysis of the collected thermal error data to achieve the migration direction of the maximum error amount of spindle.(4) The paper determines the scheme of arrangement of spindle temperature measuring point combining with the way by adopting thermography to measure the spindle’s temperature field and analyzing the spindle structural features. On the basis of simply discussing to optimize spindle temperature measuring point, the paper chooses to combine the fuzzy clustering analysis with correlation coefficient method to optimize spindle temperature measuring point.(5)In view of the complex and diverse faulty causes, and complex professional maintenance knowledge of NC machine, this paper uses VBA language programming to create a simple database to diagnose fault and query based on the Access platform, which makes faulty maintenance and query of NC machine more convenient.