对给定公差范围的—σ计量值控制图

-σ Variable control Chart the given margin toleranle process

目前关于工序生产过程的计量值控制图,国家标准及一般书刊多只介绍X—S、(?)—R、(?)—R和X—Rs图。这些图的建立一般是某一工序完成后,从其样本的处理数据才够绘制控制图的各控制线,这样就难以达到“预防为主”的目的。(?)—σ图则可以从产品某一给定的参数指标直接绘制控制图需要的各控制线。即它可以预见建立控制图,然后按照根据工序生产过程抽样的数据点在图上。从而可随时掌握工序生产过程的状态,当出现异常现象时,及时予以调整,以保持稳定的生产过程和产品的质量水平。

There are variable control charts (X-S,X-R,X-R, and X-Rs Chart) of cpork processes in National Standard and The. most of books and magazines at present, which can only be established from the treated samples' lata after certain work process finisbed. It makes hard to reach the aim of 'putting prevention first.' The X-σ chart can be drawn the reguired control Lines from the given paramelis objectives of product directly. i.e. whih can be established in advance, then plotted the points according to the samples' data of the work process on the chart. So that ae can hold the condition of the process at anyp ime by adjustiny it properly as soon as the abnormal condition appears, kee tstable the conditior of the qrocess and the quality level of the product.