The principle of building a unified control card for the dimensional accuracy of engineering products


The issues of creating a tool for quality control of manufacturing parts with dimensional accuracy in order to prevent the appearance of defects are considered.
As a result of research, the theoretical apparatus of probability theory and mathematical statistics was used. Using the proposed general model of the distribution of linear dimensions of parts
and found estimates of its parameters allows us to find the mathematics expectation and variance of
the largest absolute deviation of size from the nominal size. On the basis of the obtained calculations, a control card is constructed; it allows one to determine the largest value at which it is necessary to stop production of products without going outside the tolerance field. The use of the proposed results makes it possible to determine the frequency of intervention in the process, where the
spread of linear dimensions increases with time and the error in estimating boundaries with the
number of manufactured products decreases. The results obtained make it possible to control the
accuracy of manufacturing machine parts during their machining

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