Mechanism Analysis And Compensation On Transmission Chain Error Of Nc Machine

Obviously, the machine tool error is transmitted through the transmission chain errorby step, eventually, reflected directly in the quality problem of machining workpiece. It isevident that to improve the quality of NC machine be equivalent to enhance the precisionof the workpiece. This paper is mainly devoted to the mechanism and compensationtechnology alike on transmission chain error of NC machine, of which the classification,mechanism, identification method is intensively studied with endeavor to perfect thedetection along with compensation technology on positioning accuracy of NC machine,facilitating greatly the boost on precision of NC machine.Is the mechanism of the typical transmission chain error is analyzed theoretically withmight and main in this paper. Actually, the error affecting the accuracy of NC machinedoes include reverse clearance error, ball screw pair cycle error, axial movement error ofscrew, besides screw pitch error. Moreover, the mathematical model of theabove-mentioned error is established, analyzing emphatically the main source of error withthe inversion method.Measurement the precision of NC machine by the laser interferometer, themeasurement data is then handled seriously. In the process of the identification oftransmission chain error, indeed, the error is provided with a sea of analysis according tothe error data waveform graph and the establishment of the mathematical model, finallyacquiring safely the error sources affecting the accuracy of NC machine.Based on the principle and method of error compensation, the allowablecompensation error is compensated with effect. Then why the measurement errors of thelaser interferometer is produced is detailed introduced, establishing accurately the testingdata of the mathematical model, conduciving to markedly advance the precision of the NCmachine for error compensation.The periodic error is roundly measured with the inversion method by the laserinterferometer, in which different measuring distance and different starting point in thesame distance are adopted, with the observation of the measuring graphics. Through the observation and summary alike, undoubtedly, it is settled that the periodic error of ballscrew assembly be stemmed from the axial movement and the periodic error of screw pitch.Among them, the existence of short cycle error is the main cause of periodic error.It is the measurement as well as compensation for error of certain NC machine that isimplemented to an inch. Experiments show faithfully that in order to make the precision ofthe machine tool, the compensation interval should be pitch integer times as far as possible,as it were, the compensation is a fruitful means to signally boost the accuracy.