Machine tools are fundamental equipment in industrial production, and their processing quality exerts a direct impact on the quality of the component product that they process. Thus, machine tool manufacturers develop various machine tools depending on market needs and processing functions, and the processed component products generally possess multiple smaller-the-better, larger-the-better, and nominal-the-best quality characteristics at the same time. For this reason, this study employed the widely used process capability indices, C pu , C pl , and C pk to develop a model that can evaluate the process quality of component products and analyze the processing quality of various machine tools. We first converted the process capability indices into functions of the accuracy and precision indices and constructed a multi-characteristic quality analysis chart that can identify the reason for poor process quality in a quality characteristic. Furthermore, considering the fact that the process capability indices can only be estimated, which may lead to misjudgment in the evaluation of process quality, we derived the 100 ( 1 - α ) % upper confidence limits of indices and the coordinates formed by the corresponding accuracy and precision indices. Manufacturers can then evaluate the process quality levels of the quality characteristics based on where the coordinates falls in the multi-characteristic quality analysis chart. This can more reliably assist manufacturers in monitoring the processing quality of their machine tools and providing feedback to the machine tool manufacturers for machine improvement.

中文翻译：

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从加工产品分析机床加工质量：球阀加工机实例

机床是工业生产中的基础设备，其加工质量直接影响其加工的零部件产品的质量。因此，机床制造商根据市场需要和加工功能开发各种机床，加工的零部件产品一般同时具有多个越小越好、越大越好、标称最好的质量特性。为此，本研究采用广泛使用的过程能力指标C pu 、C pl 和C pk 来开发一个模型，该模型可以评估组件产品的过程质量并分析各种机床的加工质量。我们首先将过程能力指标转化为准确度和精密度指标的函数，构建了一个多特征质量分析图，可以在一个质量特征中识别过程质量差的原因。此外，考虑到过程能力指标只能估计，可能会导致过程质量评价的误判，我们推导出指标的100 ( 1 - α ) %置信上限和相应精度形成的坐标和精度指标。然后，制造商可以根据坐标落在多特征质量分析图中的位置来评估质量特征的过程质量水平。