• CN：11-2187/TH
• ISSN：0577-6686

• •

### 基于定位法线的工件自由度分析几何定理及应用*

1. 太原科技大学教育部重型机械工程研究中心 太原 030024
• 出版日期:2017-05-05 发布日期:2017-05-05
• 作者简介:

王晓慧，男，1959年出生，教授。主要研究方向为尺寸工程，机械精度设计理论及应用，计算机辅助夹具设计。

E-mail：houmawxh@sina.com

• 基金资助:
* 国家自然科学基金资助项目(51575373，51175360）; 20161011收到初稿，20161219收到修改稿;

### The Geometry Theorem and Application of Degree of Freedom Analysis of Workpiece Based on Location Normal

WANG Xiaohui, WU Dongzu, LAN Guosheng, WANG Youli

1. Heavy Machinery Engineering Research Center of Education Ministry， Taiyuan University of Science and Technology， Taiyuan 030024
• Online:2017-05-05 Published:2017-05-05

Abstract:

：When workpiece is in combined location in non-coplanar planes, every location point is usually distributed at non-orthogonal and non-coplanar planes. The degree of freedom of workpice in fixtures is sometimes misjudged by using traditional positioning principle, which always leads to failure of fixture design. For this problem, the normal at location point where workpiece lies in fixtures is nominated as location normal. A set of geometry theorems that can judge the location state of workpiece are derived according to the amount of location normal and the geometry relationship between them. Some judging principles are given out for normal distribution corresponded with over-positioning of workpiece. The geometry theorem makes the judging method of degree of freedom more precise, simpler and more intuitive and over-positioning of workpiece can be avoided effectively at the same time. Several complicated examples are enumerated. The degree of freedom of workpiece can be judged and the solution can be given out for the unreasonable location by the means of using geometry theorem, which prove that the degree of freedom of workpiece in complicated location state can be judged quickly and accurately. The geometry theorem of workpiece location has developed and completed the location theory of workpiece and is good for correct judgment to the degree of freedom of workpiece in computer aided fixture design.