最大实体要求下几何要素检验理论的研究

发布时间：2018-05-02 04:46

本文选题：最大实体要求 + 模拟基准要素　；参考：《杭州电子科技大学》2015年硕士论文

【摘要】：目前的产品测量技术主要针对公差独立原则下的基准要素建立的基准坐标体系，当被测要素的基准遵循公差相关要求时，，由于设计基准设定的边界尺寸与实际测量基准的轮廓不重合，导致被测要素的设计设定基准与实际测量基准不统一，公差标准允许设计设定基准可以相对于测量基准在两个边界尺寸之差的范围内的浮动，进而导致被测要素公差带也跟随浮动，从而扩大了被测要素公差带的范围。对于复杂的基准布局，这一扩大范围目前还未有相应的解决方法。为了解决这一问题，本文基于“几何要素控制点理论”和模拟基准要素的概念，研究最大实体要求下几何公差基准参考框架的建立方法，并提出一个可行的计算法则来表示基准偏差量对被测要素的补偿。研究内容主要包括以下几方面：（1）模拟基准要素的建立方法。根据模拟基准要素的概念，利用VC++6.0开发平台编写最大实体要求下模拟基准要素边界尺寸的计算函数，并将获得的边界尺寸存入对应的基准信息链表。（2）基准参考框架运动关系的构建方法。利用基准参考框架的概念和几何要素控制点理论，建立最大实体要求条件下几何公差模拟基准要素相对于基准实际状态的浮动范围，进而获得被测要素设计要求和实际测量条件下基准参考框架之间的运动关系，并用曲柄摇杆机构等机构模型等价表示出这种运动关系。（3）基准参考框架与被测几何公差带范围之间关系的分析方法。利用曲柄摇杆机构表示基准参考框架运动关系的等价机构模型，用曲柄长度和摆杆摆角分别表示基准参考框架的偏差量，其中曲柄长度就是被测目标要素的几何公差值的扩大量，而摆杆摆角则修改和扩大公差带的形状。本文通过UG NX7.5软件平台，利用VC++6.0软件和UG系统自带的实现UG/OpenAPI二次开发功能模块实现计算机辅助公差设计的功能要求，以位置度公差的测量为实例，验证当被测要素的基准遵循最大实体要求时，被测要素在设计条件下的基准参考框架对于被测要素公差带的影响。
[Abstract]:The current product measurement technology is mainly aimed at the datum coordinate system established under the principle of tolerance independence. When the datum of the measured element follows the tolerance related requirements, Because the boundary dimension set by the design datum does not coincide with the contour of the actual measurement datum, the design setting datum of the measured element is not unified with the actual measurement datum. The tolerance standard allows the design of the datum to float in the range of the difference between the two boundary dimensions relative to the measuring datum, which leads to the tolerance zone of the measured element following the float, thus enlarging the range of the tolerance zone of the measured element. For the complex benchmark layout, the scope of this expansion has not yet corresponding solutions. In order to solve this problem, based on the theory of control point of geometric elements and the concept of simulated datum elements, this paper studies the method of establishing the reference frame of geometric tolerance datum under the requirement of maximum entity. A feasible calculation method is proposed to represent the compensation of the datum deviation to the measured elements. The research mainly includes the following aspects: 1) the method of establishing simulation datum elements. According to the concept of simulation datum element, the calculation function of boundary size of simulating datum element under maximum entity requirement is compiled by using VC 6.0 development platform, and the obtained boundary dimension is stored in the corresponding datum information chain list. 2) the method of constructing the motion relation of the frame of reference. Based on the concept of reference frame and the control point theory of geometric elements, the floating range of geometric tolerance simulation datum elements relative to the actual state of the datum is established under the condition of maximum entity requirement. The kinematic relationship between the design requirements of the measured elements and the reference frame under the actual measurement conditions is obtained, and the kinematic relationship is expressed by the equivalent mechanism model such as crank and rocker mechanism. The analysis method of the relation between the reference frame and the tolerance zone range of measured geometry is presented. Using crank rocker mechanism to express the equivalent mechanism model of reference frame motion relation, using crank length and pendulum angle respectively to express the deviation of reference frame. The length of the crank is the enlargement of the geometric tolerance of the measured target element, while the pendulum angle modifies and expands the shape of the tolerance zone. Through UG NX7.5 software platform, using VC 6.0 software and UG system to realize UG/OpenAPI secondary development function module to realize the function requirement of computer aided tolerance design, taking the measurement of position tolerance as an example. When the datum of the measured element obeys the maximum entity requirement, the effect of the reference frame of the tested element on the tolerance zone of the tested element under the design condition is verified.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG801

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