PRECISION OF HOLE PROCESSING BY REAMER-BROACHING

"To process holes in bushings, flanges, pulleys and other similar parts, various types of metal-cutting tools are used: drills, countersinks, reamers, broaches, and others. The use of a particular tool depends on the required accuracy, roughness and type of production. Unfavorable cutting conditions cause an increase in the mechanical load on the blade section, where the chips separate from the main layer of material and its deformation, which is accompanied by significant heat release and low tool life. This article proposes the processing of high-precision holes – a reamer-broaching, the design of which is confirmed by the patents of the Republic of Kazakhstan, and structurally combines the features of a reamer and a broach. This design provides favorable cutting conditions, which contributes to high machining accuracy and low surface roughness. In cross-section, the profile of the helical teeth of the reamer-broaching can be of the following versions: standard profile of the reamer teeth, equal-wide tooth profile, like a broach with a helical equal-wide tooth, cutting-deforming. The results of production testing of samples are given, the analysis shows that the accuracy of the diametrical dimensions of the holes after processing with a reamer-broaching increased by 1.2 quality compared to a machine standard reamer; the roughness decreased by 1, 2 classes. Keywords: processing, hole, accuracy, quality, roughness, reamer, broach."