Determination of Flanging Parameters and Length of Screwing in Producing Holes by the Method of Thermal Drilling in Thin-Sheet Metal

Abstract

In mechanical engineering, products from sheet blanks are widely used, which provide for threaded fastening of various components to them. The formation of holes for thread in such blanks has a number of difficulties. The main problem is to ensure the strength of threaded joints. The parameters that determine the strength of a threaded joint are the diameter and pitch of the thread, the ratio of the mechanical characteristics of the material of the bolt and nut, and the length of screwing. In case of insufficient screwing length, the threaded joint is destroyed. To increase the length of screwing in thin-sheet blanks, sheet bending, welding of sleeves, preliminary punching of holes and other methods are used. However, the existing methods do not have sufficient adaptability. With regard to thin-sheet blanks, the most rational use of the method of forming holes is the method of thermal drilling. This eliminates the use of additional elements to increase the length of screwing. This article presents experimental and theoretical studies of the relationship between the shape and geometrical dimensions of flanging, made by thermal drilling in thin-sheet metal, with a screwing length. The influence of the shape and geometrical dimensions of flanging a hole made by thermal drilling in thin-sheet metal on the length of screwing and the strength of a threaded joint for cutting is considered.