板料Ⅴ型弯曲工件端部摆动区域初步研究

Preliminary study on swing area in the end of Ⅴ-shaped bending part

为避免工件端部与模具或压力机发生干涉,基于变形过程分析和一些假定,列出了忽略模具圆角的板料V型弯曲工件端点轨迹关于工件端部翘起角α的参数方程,证明了轨迹曲线极值坐标相应的端部翘起角αm由模料尺寸比l/L决定,当l/L大时,αm小,反之则大;凹模半角β≤（π/2）-αm,端点轨迹曲线才有极值。给定β和l/L可以决定凹模口外工件摆动区域大小,当l/L大时,区域小,反之则大。通过列方程和作图相结合,分析了在l/L=（0.50-0.30）范围内,增大凹模圆角、增大凸模圆角以及凹模圆角与凸模圆角叠加3种情况下的工件端部摆动区域的变化;给出了接近实际情况的工件中性层端点轨迹方程。最后指出,应视空间宽松程度不同,采取不同方法预留工件端部摆动区域。

In order to avoid the end of workpiece intervening with die or press,the endpoint trajectory parameter equation with camber angel α of V-shaped bending part ignoring the corner radius of die was listed based on analysis of deformation process and some essential assumptions. It is proved that the ratio of die mouth and material length（ l / L） determines the value of αm,and the bigger the l/L is,the smaller the αmis,vice versa. When die half-angel β≤（ π /2）- αm,the extremum can exist in endpoint trajectory curve. β and l/L also determine the swing area of workpiece out of die,and the bigger the l / L is,the smaller the area is,vice versa. Combining equation and mapping,the change of swing area was discussed in l / L =（ 0. 50- 0. 30） under three conditions as increasing die corner radius,increasing punch corner radius,or additive effect of die and punch corner radius. The approximate trajectory equation of neutral plane endpoints was given. So the size of swing area in the end of V- shaped bending part should be determined according to the degree of space shortage.