Research On Eccentric Precision Assembling And Calibration Technology Of Diamond Grinding Wheel

Grinding is usually used as the final finishing method in various machining methods.The required dimensional accuracy and geometric accuracy can be machined by grinding.With the increasing demand for large aperture and high-precision optical components in the fields of laser fusion,space optical system and astronomy,grinding technology plays a more and more important role in the field of optical ultra precision machining.It is an important guarantee to realize the deterministic batch processing of aspheric components.As a tool for diamond grinding wheel,the error caused by trimming and installing eccentricity can not be avoided in the actual processing.The eccentricity error of grinding wheel can directly affect the machining precision of the workpiece,the service life of the grinding wheel and the processing of the workpiece.The traditional method of eccentric adjustment generally depends on manual installation of workers.This method has the disadvantages of non automation,low efficiency and poor fitting precision.Therefore,it is necessary to develop an eccentric precision device for grinding wheel and the eccentric precision installation technology of grinding wheel.In this paper,a set of grinding wheel eccentricity precision alignment system is developed with piezoelectric ceramic element as the main executive mechanism of precision grinding wheel eccentricity.In order to obtain the signal characteristic information caused by the eccentric installation of the grinding wheel,a single point measurement model of the eccentric characteristic information of the grinding wheel based on the laser is put forward.Compared with the traditional multi point measurement,it can not only simplify the construction of the measuring platform but also reduce the use of the sensor,and save the actual application development cost.On the basis of wavelet packet multi threshold criterion denoising,an improved multi threshold wavelet packet thresholding denoising method(hereinafter referred to as improved FMC method)is proposed.The denoising method combines the advantages of the singular point culling method of detection and interpolation and the multi threshold denoising method of wavelet packet,which can effectively reconstruct the eccentric production of the grinding wheel.On this basis,a high precision approximation algorithm based on the minimization of roundness error of the grinding wheel is proposed.The algorithm can quickly reduce the eccentricity and the eccentric phase of the grinding wheel by the coordinate conversion,the normalization treatment and the weight correction.Finally,according to the geometric relation,a kind of deviation can be put forward.The decomposition algorithm is decomposed into three directions along the circumference,and the piezoelectric characteristic curve of each piezoelectric actuator is obtained by linear interpolation.Through the test of the eccentric fitting of the grinding wheel on the machine tool of the project group,it is found that the installation times of the eccentric precision charging system can be controlled within 4 times,and the final convergence precision can reach 8 u m or even higher,and it has practical value in the engineering.