Research On Planning Of Compound Filling Path For Arc Surfacing Forming

The arc surfacing forming process is one of the important branches of metal additive manufacturing technology.Its high efficiency and low cost make it widely used in architectural design,product prototype design,automobile manufacturing,aerospace and other fields.The parts formed or repaired by surfacing have the characteristics of long service life and good process performance.A reasonable surfacing fill path can not only improve the forming accuracy and process performance of the part,but also improve the forming efficiency.In this paper,a more in-depth study of arc surfacing forming path planning is carried out,and related algorithms are optimized and implemented,an arc surfacing forming device is designed,and supporting slicing software is developed.The main research contents are as follows:First,the effective data of each triangle in the STL format 3D model is extracted.Based on the grouping of triangles using the equal-thickness layering algorithm,combined with the characteristics of arc surfacing forming,the layered topological relationship of triangles is proposed.Algorithm to construct the topological relationship between each layer of triangular faces.According to this,intersect the plane with the triangular patch,and extract the cross-sectional contours of the model.The feature point method is used to determine the contour boundary trend,and the original contour data points are optimized.Secondly,aiming at the problem of arc surfacing filling effect.Based on the characteristics of common filling paths,a composite filling path combining contour offset and scanning lines is used to achieve the filling of porous cross-sectional contours.The vector method is used to derive the isometric line equation,and the intersection points of adjacent adjacent isometric lines are solved in sequence to obtain the node set of the contour offset filled path.A zonal direction-changing scanning algorithm is used to generate the scanning line filling path,and the processing method of the singular intersection of the scanning line and the offset contour is given.Then,the actual forming efficiency of surfacing is addressed.On the basis of obtaining the compound filling path,the optimization mathematical models of the contour offset filling path and the scanning line filling path based on the minimum empty travel are established respectively.And adopt the greedy algorithm based on potential starting point to optimize the empty travel between each path,shorten the empty travel between each path.Finally,an arc surfacing welding device based on rectangular coordinates was designed and developed.The mechanical body composition and control system realization of the device were briefly introduced.Based on the core algorithm of this paper,the matching slicing software was developed.The slicing software was used to slice the STL model to generate a Gcode file containing the filling path information for the surfacing machine to perform solid forming.It can effectively fill the porous section,the developed rectangular coordinate arc surfacing machine is stable and reliable,and can repair the failed crankshaft surfacing.