摘要 |
FIELD: process engineering. ^ SUBSTANCE: invention relates to production of hollow elements, e.g. nuts, to be secured on pats made from sheet material. During first manufacturing stage, cylindrical recess is made in first wide side of rectangular section profile. Cylindrical hollow ledge surrounded by ring-like recess is made on second wide side to form rivet part. During second stage, web left between cylindrical recess bottom and hollow cylindrical ledge bottom is punched or cut out. Thus, through hole is produced. During third stage, hollow elements are separated from profile and, if required, are provided with thread. Note here that combined consecutive-action tool with several working positions is used. ^ EFFECT: higher mechanical properties and reliability of hollow elements, longer life. ^ 33 cl, 27 dwg |