Study of deformation method of hollow workpieces with bottom by dies with chamfer

Abstract

Markov O., Stankov V., Panov V., Zinskyi V. Study of deformation method of hollow workpieces with bottom by dies with chamfer.

The paper proposes and investigates a new method for pulling blanks with a tool with bevels. The blanks were pulled by cut-out heads with cut-out angles α = 90°, 115°, 140°, cut-out bevel angles β = 10°, 20°, 30°, and the length of the horizontal flange of the deforming part (determining the feed rate) a = 100.0 mm. The degree of blank deformation was 20%, 40% and 60%. The general regularity for the investigated forging schemes is that when broached hollow billets with a decoction diameter d0/D = 0.3, the aversion is forged with a reduction of more than 40%. The results obtained show that the initial diameter of the workpiece hole has a predominant effect on the forging. However, the intensity of forging the decoction decreases with an increase in the degree of reduction of the workpiece. The general pattern for the studied forging schemes is that the intensity of prevention forging is the same at different reductions for constant ratios of the workpiece dimensions. When feeds are more than 0.2D, there is no qualitative and quantitative change in the dependence of the change in the degree and intensity of forging prevention. The recommended feed should be in the range (0.1...0.2)D. After carrying out a theoretical study, studying the deformed state of the workpiece metal and the cylinder hole forging mechanism, the most effective scheme was chosen, in which the cut-out heads had a cut-out of 115° and a width of the deforming part of 0.1D, geometric parameters d0/D = 0.8. In this scheme, during broaching, the metal flow occurred along the axis, which contributes to the continuation of forging and not complete forging of repulsion.