METHOD OF MAKING INNER SPLINES IN TUBULAR BLANK Russian patent published in 1997 - IPC

FIELD: technique of working shaped openings of tubular blanks, for example of splined sleeves, by axially symmetrical reduction of blank on shaped mandrel with use of deforming die. SUBSTANCE: method of making inner splines in tubular blank by reducing it on shaped mandrel through die comprises step-by-step reduction of blank subjected to free elongation. Total tightness A of die onto blank is determined according to depth h (mm) of formed splines A= k1xh, where k1= 2.8-3.2. At each n-step of i-step reduction process die tightness onto blank a_n = k2 x A x i^-0,631/(2,67•i^-0,415)^n-1 mm, where k2 = 0.9-1.1. EFFECT: high accuracy formation of spline profile. 1 tbl