管坯料内壁多槽劈挤成形折叠成因及规律分析

Analysis on Causes and Rules of Fold for Tubular Blank Inner-wall Multi Grooves Splitting Extrusion Forming

劈挤成形容易出现折叠缺陷。为了研究管坯料内侧劈挤成形时出现的折叠规律,以内径50.2 mm和外径为57 mm的管坯料为研究对象,劈挤成形出高度为20 mm,槽数为40的内齿槽。在劈分角和劈刃倾角不变的情况下,运用Deform-3D数值模拟软件对成形过程进行了模拟分析,研究了相邻凸模夹角β不变的情况下,劈挤凸模工作面间夹角α和劈入深度h0对劈挤产生折叠的影响。结果显示,在夹角β一定的情况下,α值越大,折叠越严重,且折叠变化越急剧,当α≤30°时,没有折叠;劈入深度h0越小,折叠越严重,当h0≥1.3 mm时,折叠消失。从应用的角度考虑,α宜取较小值,h0应取较大值。

Splitting extrusion forming causes fold defect easily. To study the fold defect rules of tubular blank inner-wall splitting extrusion forming, taking a tubular blank with 50.2 mm inner diameter and 57 mm outer diameter as research object,40 teeth internal alveolus with depth of 20 mm was formed by splitting extrusion. In the cases of unchanged splitting angle and splitting blade angle, the forming process was analyzed by using Deform-3D numerical simulation software. In the case of unchanged adjacent punch angle β, the influences of splitting extrusion punch working face angle α and splitting depth h0 on the fold were studied. The results show that in the case of unchanged angle β, the greater α value is, the more serious the folding is, the sharper the folding changing is. When α ≤15°, there is no fold. The smaller splitting depth h0 is, the more serious the folding is. When h0≥1.3 mm, the fold disappers. From the application point of view, α should be small and h0 should be large.