Method of the internal threads profiling at milling

Abstract

Analysis of the works devoted to thread milling showed that milling of the threads with a special profile differing from the metric profile was not sufficiently studied. Based on data of the existing threads profile analysis, the paper proposes a generalized profiling scheme using the example of a round thread. The theory of envelopes of the cutting tool positions family makes it possible to analyze the shape of the resulting thread profile and the cutting tool profiling in shaping with a kinematic scheme of thread milling with the parallel thread and tool axes. Mathematical expressions are provided that allow calculating geometric error in the round thread using the proposed method and profiling a thread cutter to form the thread of the accepted accuracy degree. The specified method could be extended to a thread with any profile described by a mathematical expression in its axial plane. Study results could be useful to the developers in designing the thread mills and to the technologists to assess the possibility of using thread milling in machining threads with the round profile.