Research On Motion Generation And Machining Area For Machining Complex Surface

Nowadays, development speed of world economy is surprising. The performancerequirements of products are becoming higher and higher. With the scientific andtechnological progress, the products with complex surface have come into world,which were applied in the fields of aerospace, die, tool, etc.. Therefore, complexsurface becomes research focus in recent years. Under financial support of theprojects named National Basic Research Program of China, this thesis investigatesmotion generation for machining axisymmetric aspheric surface, motion generationfor machining free-form surface, dimensional range of machining parabolic surfaceand hyperboloidal surface. And the simulation experiment is accomplished, whichshows the validity of theoretical analysis.Based on analysis method, motion generation for machining axisymmetricaspheric surface is researched. Based on the configuration characteristic ofaxisymmetric aspheric surface, the mathematical description of tool and workpiece isobtained with coordinate transformation method. The relationship of position andorientation between tool and workpiece is analyzed. The matrix of positon andorientation between tool and workpiece is set up. The essential movement units areproposed. The movement function scheme of the machine tool for machiningaxisymmetric aspheric surface is generated. The results of design are optimized andthe structural configurations of the machine tool are obtained according to theexpression of movement structure. As the rotational axis of the tool is always vertical,30optimized structural configurations are obtained. And as the rotational axis of thetool coincides with the normal at cutting point of workpiece,18optimized structuralconfigurations are obtained.Based on analysis method, motion generation for machining free-form surface isresearched. Free-form surface is divided into eight basic surfaces by differentcurvature. Based on the configuration characteristic of eight basic surfaces, therelationship of position and orientation between tool and workpiece surface isanalyzed. The matrix of position and orientation between tool and workpiece surfaceis set up. The essential movement units are proposed. The motion schemes of themachine tool for machining eight basic surfaces are generated. The motion schemesare synthetized for machining free-form surface with multiple basic surfaces. Thebasic modules and the necessary motions for generating free-form surface are clarified. Selection principle and method of motion configuration for machining free-formsurface is presented. And the possible structural configurations of the machine tool areproposed and optimized.The dimensional range of machining axisymmetric aspheric surface for machinetool is researched. Based on coordinate transformation method, the mathematicalmodel for machining axisymmetric aspheric surface is set up. Parabolic surface isstudied. The functional relationships between workpiece parameter, tool parameter,cutting state parameter and machine tool performance parameter are analyzed. Thevariation laws of key technical indexes such as the position of tool locating in verticaldirection, the maximum vector height and aperture of parabolic surface, swing rangeof tool, the minimum arbor distance of tool locating tool carrier in lateral are deduced.An algorithm on dimensional range of machining axisymmetric aspheric surface formachine tool is presented. It can be estimated swiftly that whether the machine toolcould do it before machining axisymmetric aspheric surface by means of inputtingstructure parameters of axisymmetric aspheric surface and motion ranges of machinetool. The simulation experiment results show the validity of the algorithm.Interference area for machining hyperboloidal surface is discussed. Themathematical model for machining hyperboloidal surface is set up. Based on theanalysis of parameter characteristics of hyperboloidal surface, the variation law of theslope limit value of tangent at arbitrary point on hyperboloidal surface and the slopelimit value of the axis of tool is discovered. Based on the discovery, the functionalrelationship between parabola parameter, tool parameter and the square of eccentricityis obtained. The parameter criterion that there is no interference as machininghyperboloidal surface is deduced. The interference areas corresponding to differentfunctional relationships between cutting angle and the square of eccentricity areclarified. As the parameters are in the possible interference area, the maximum vectorheight and aperture of hyperboloidal surface are calculated. The simulationexperiment results showed the validity of theoretical analysis, which facilitates theparameter selection for machining hyperboloidal surface.