Technology of Processing Parts with Square and Rectangular Holes

Abstract

This paper analyzes the technology of obtaining non-technological parts (disks, bushings, flanges) with a square or rectangular hole. The author presents the main types of non-technological parts and lists the main methods of machining tetrahedral holes of the closed and through type. Particular attention is paid to obtaining square holes with the help of a Watts drill, the geometry of which is based on the equilateral triangle Relo. The spectrum of use of this technology in the field of mechanical engineering and instrument making, as well as its positive and negative aspects, is disclosed. The main motions of this cutting tool during the machining of square holes are listed, and the basic error in obtaining the real square profile is considered. The idea presented by the author for obtaining holes with a rectangular cross-section consists in pre-processing the contour of the hole and splitting the untreated sections into squares for subsequent processing. The paper presents recommendations when choosing the diameter of the cutting tool for preliminary processing of the contour of a rectangular hole. Also, the author considers the inverse problem of manufacturing parts with tetrahedral holes, which is based on the use of auxiliary tooling for further external processing of the workpiece. The main type of auxiliary tooling used is a collet or rigid mandrel with a square or rectangular cross-section of the mounting surface. In the ANSYS software environment, the process of deformation of the mandrel petals with various applied forces is simulated. For uniform deformation of the mandrel petals in two axes, recommendations for changing the design of the collet mandrel are listed. In summary, the author lists the main conclusions and results on the technology of processing square and rectangular holes and the technological equipment used in this technology.