Speed Optimization Of CNC CAM Grinding

With the development of manufacturing technology, the demand on the quality andquantity of CAM and CAM shaft is increasing. In such circumstances, the requirements ofCAM and CAM shaft grinding towards the direction of high precision, high efficiency, highflexibility, directly to the CAM production technology level and grinding theory research putforward higher requirements. In this topic, it is deduced to mathematical relations betweengrinding wheel and cam with different followers. Combined with the actual CAM grindingprocess and the characteristics of the CAM contour curve, summarize the regular pattern ofthe CAM grinding process. When the grinding speed is large, the error of the actual camprofile obtained is relatively large; while reducing grinding speed, the actual cam profile iscloser to the theoretical profile of the cam. In order to solve the imbalance between thegrinding precision and machining efficiency, we propose the method of the speedoptimization, the small curvature variation part of the cam (base circle) is cut at high speed,and the large curvature variation part of the cam (sensitive area) is cut at low speed. Wedesign CAM grinding speed optimization algorithms according to the optimization thoughtwe proposed and do experiments to test and verify by simulation platform of CNC camgrinding machine. The details are as follows:1. Deduction of mathematical relation between CAM rotational position and grindingwheel feed. For the given lift tables, the three spine interpolation theory is applied to smoothprocessing. Principle of Reversion is applied to obtain the theoretical contour of the cam.The mathematical models between cam rotational angle and grinding wheel feed are built.The theory profile curve of the cam, the grinding wheel center point’s curve and the requireddata of numerical control CAM grinding system is obtained by using MATLAB software towrite mathematical model, which provides effective resources of date for the redevelopmentof the grinding speed optimization algorithm and simulation of optimization algorithm.2. Analysis on the relationship of the CAM contour error and grinding speed. Facingthe special situation that cam profile is complex, the speed of each grinding point,acceleration and jerk will be great changes in the production process of CAM and CAMshaft. The actual shape of the cam contour is determined by the interaction of the camrotational axis (C-axis) and the wheel feed axis (X-axis) of the Machine tool. According todefinition of following error and contour error of the control system, analyzing the grindingspeed influence on the following error, the effects of the following error and grinding speedon the contour errors will be discussed and verified in the simulation platform of numerical control CAM grinding system, which lay solid foundation for the development of thegrinding speed optimization algorithm.3. Development of speed optimization method. We test and verify the relationshipbetween the contouring error and the cutting speed which we have analyzed by the model.we propose the method of the speed optimization, Aiming to improve the efficiency of CAMgrinding, the small curvature variation part of the cam (base circle) is cut at high speed, andthe large curvature variation part of the cam (sensitive area) is cut at low speed, improvingthe quality of CAM grinding. We design the control laws which are the direct optimizationmethod, the acceleration and deceleration of S type and construction curve speedoptimization method according to the optimization thought we proposed.4. Verification of the effectiveness of three kinds of speed optimization methods willreduce the error of cam profile. Three kinds of speed optimization methods are to deal withby using the MATLAB, loading data of speed optimization to the simulation platform ofnumerical control CAM grinding machine, giving the contrast analysis of the actual contourerror of speed optimization and constant angular velocity of the grinding cycle of the same.The advantages and disadvantages of three kinds of speed optimization method are analyzed.To sum up, this paper conducts mathematical relation between CAM rotational positionand grinding wheel feed, the relationship of the CAM contour error and grinding speed,CAM grinding speed optimization modeling. These questions are verified by using theMATLAB. As it should be, there are some other problems for further research, such as theapplication of intelligent controller in the control system to realize online compensation;whether it can guide for grinding of the next cycle through data before it is passed.