Stick-slip Simulation And Optimization Of Feeding System In Silicon Ultra-precision Grinding Machine

Feed system is the core of ultra-precision silicon grinding, whose performance indicatorsare the key factors of the processing accuracy. The minimum amount of exercise andminimum resolution of the feed system plays a decisive role in the performance indicators.To meet the processing requirements, ultra-precision silicon grinding requires that feed rateshould achieve0.0001mm/s in the grinding stage required, minimum amount of Z-axisexercise requires to0.1mm, and Z-axis minimum resolution needs to0.1mm. Due to the feedrate is very low, it is prone to stick-slip phenomenon. As the machine is stick-slip, thecomponents velocity is uneven and it can take an impact on the accuracy ofmicro-displacement and acceleration rail wear, which can affect the silicon machiningaccuracy and surface quality. Therefore, in order to ensure the quality of silicon processing,stick-slip mechanism analysis and effective preventive measures are musts.At first, based on the structure analysis of feeding system in a certain type of siliconultra-precision grinding machine, the relationship of the feeding table system output torqueand displacement which considering the influence of angular error and other error factors isestablished.Second, stick-slip is analyzed and the mechanical model, the mathematical model, thecritical speed formula of the stick-slip is established; because the speed of the grinding stageis less than the critical speed, there exists stick-slip in the feeding system.Third, the rigid body coupling virtual prototype model of the feeding system isestablished using ADAMS and the speed curve is get.At last, the factors—stiffness in the main direction of motion, quality of the system, therail surface and the slide surfaces difference between static and dynamic friction whichinfluencing the stick-slip is presented. Analyzed by simulation: the smaller the damping is,the smaller the stiffness of the transmission system is, the greater the quality of the movingparts are, the greater the difference of static and dynamic friction is, it is the more prone to thestick-slip; the anti stick-slip measure is presented finally, the stick-slip is no longer relevant.