Optimality of the Machining Process Based on the Mutual Influence of Design and Technological Dimension Relations

Abstract

In the given work it is shown, that at machining the technological dimensional structures are optimum if they are similar to the design dimensional structure of a detail. The conditions of the locating and fastening, and also some technical requirements interfere achievements of similarity. In these cases the directed change of the design dimensional structure of a detail is recommended due to recalculation of the sizes. From this point of view creation of technological process represents a compromise of mutual approche of the dimensional structures of a detail and of a technological system. Technological process may be built from operation elements, but they (the operation elements) do not have the necessary characteristics to create the dimensional structures. These characteristics are not formed during decomposition because the relevant details dimensional structure is not taken into account. The most appropriate entity as element of which may be built the technological process is a technological mounting. The mounting has a dimensional structure and includes the communication elements - the sizes up to locating surfaces Thus, the dimensional designing of technological processes results in optimality if it is possible to achieve the similarity of design and technological dimensional structures in the following order: creation of the blank's dimensional structure similar to the detail's dimensional structure; formation of optimum technological dimensional links of the first technological operations or mounting (roughing) by resizing if necessary of the blank and of the detail; formation of optimum technological dimensional links on the subsequent technological operations or mounting by resizing if necessary of the detail in progress; formation of optimum technological dimensional links on the final technological operations or mounting by resizing if necessary the detail; calculation of the minimal machining allowances; the dimensional analysis of technology with calculation of the operational sizes, their tolerances and limit deviations; formation of drawings of the blank.