平面孔系尺寸的建模及其应用研究

Modeling and application research of planar multiple-holes dimension

针对传统的孔系尺寸计算需要绘制尺寸链图、判断增减环,以及存在过程复杂易出错等问题,提出用工序尺寸的路径图来描述平面孔系的各个孔的加工顺序和加工基准.基于路径图建立全相关的尺寸模型,求解得到具有矢量特征的坐标尺寸,并利用全微分法求解坐标尺寸的公差.避免了现有方法的缺陷,适用于加工中心及数控机床上孔系加工的计算机编程计算.

Aiming at the problem that traditional calculation of the multiple-holes＇dimension needed to draw the dimensional chain and to judge whether the dimensional chain ring increased or decreased,and the process was complicated and easy to make mistakes,process dimension path graph was proposed to describe the sequences and reference of the process of each hole in planar multiple-holes.A full correlative dimension model was established based on the process dimension path graph,which could obtain all coordinate dimensions with vector feature.Dimension model was solved and tolerances of all coordinate dimension were obtained by using total differential equation.The drawback of available method is avoided using this proposed approach,and this approach is applied to program calculation of multiple-holes processing on machine center and numerically-controlled（NC）machine tool.