通过建立一系列夹具定位规则,实现了定位基准的自动选择和基准上定位点的自动布局。将工件定位基准的约束自由度定义为线平移、线转动、面平移和面转动四种类型。建立从工序要求中自动提取约束自由度信息的方法。采用矢量形式表示四种约束自由度、采用定位点布局表示基准的定位能力及能力大小,据此建立约束自由度任务的合并、分解、坐标转换等运算规则。研究基准定位能力的评价方法和基准约束自由度任务冲突的判断方法。提出基准冲突问题和基准定位能力问题的解决方法,建立零件基准面上的定位点布局规则。
A series of principles about fixture locating plan are proposed to automate the selection of locating datum and the layout of locating points. The constraint degrees of freedom(DOF) of workpiece datum can be classified into four types:linear translation DOF,linear rotation DOF,planar translation DOF and planar rotation DOF. The acquirement of constraint DOFs is realized by automatically extracting process requirements. Four kinds of constraint DOFs are represented in the format of vectors,and the locating capability of workpiece datum is denoted by the layout of locating points,by which the operation rules of constraint DOFs,such as merge rule,decomposition rule and coordinate transformation rule,are established. The evaluation method of datum locating ability and the judging method of datum conflicts are studied. The approach to the resolution of the datum conflicts and the datum locating problem is presented,and the rule of the layout of locating points is established.