在备件制作中,常有各种形状的板料制件,下料时,要画出它们的展开图。通常展开图要由制作工人根据制件在三维空间相互投影关系,在放样平台上放线,最后得出放样图。这种作法费工费时,而且工人要具有扎实的画法几何知识和熟练的放样操作技能。制件几何尺寸较大时,则要较大的放样平台。利用数控自动切割机床,则无需放样即可直接下料,只要给出制件展开后曲线边缘的方程或一系列点的座标即可。但这种机床只有专业生产厂才配备。 对于一般工厂,如果工程技术人员在给出制件形状尺寸的同时,也给出制件展开图的具体尺寸,那么制作工人便可根据展开图尺寸直接下料。但即使如此,计算量还是相当大,且容易出差错。应用电子计算机,只 Spare parts in the production, often a variety of shapes of sheet metal parts, cutting, to draw their expansion plans. Usually expand the picture to be by the production workers according to the workpiece in three-dimensional space projection relationship, put the line in the loft platform, and finally get out of the figure. This method of working time-consuming, but also workers have a solid knowledge of painting geometry and proficiency in lofting operation skills. When the workpiece geometry is larger, then a larger loft platform. The use of CNC automatic cutting machine, you do not need to lofting can be directly blanked, as long as the workpiece is developed after the edge of the curve equation or a series of coordinates can be. However, this machine is only equipped with professional production plant. For the general factory, if the engineer and technician give the specific dimensions of the plan of the workpiece as well as the shape and size of the workpiece, the worker can directly cut the material according to the size of the plan. But even then, the amount of computation is quite large and error-prone. Application of computer, only