拉胀工艺参数对半球形件成形极限的影响研究

Study on influence of process parameters on forming limit of hemispherical parts in drawing-bulging

为了提高半球形件拉胀成形的成形极限,研究了拉胀工艺参数压边力、摩擦系数、冲压速度以及凹模圆角对拉胀成形极限的影响规律。通过数值模拟分析与正交实验设计相结合的研究发现:影响成形极限最大的因素是压边力,其次是凹模圆角和摩擦系数,而冲压速度对成形极限的影响程度相对较弱;成形极限高度随着压边力、摩擦系数以及冲压速度的增加而降低,而随着凹模圆角的增大而增大。综合分析,为了提高半球形件拉胀成形极限,最合适的压边力为20 k N,凹模圆角为12 mm,摩擦系数为0.125,冲压速度为2000 mm·s-1。最后通过工艺实验表明,试验结果与模拟结果相一致,大大提高了半球形件的拉胀成形极限。

In order to improve the forming limit of drawing-bulging hemispherical parts, the influences of blank holder force, friction coef- ficient, stamping speed and die fillet radius on drawing-bulging forming limit were studied. Combining numerical simulation with orthogo- nal experiment, it is found that the biggest factor that effects the drawing-bulging forming limit is the blank holder force, which is followed by die fillet radius and friction coefficient, and while the effect of stamping speed is relatively weak. The drawing-bulging forming limit de- creases with the increase of blank holder force, friction coefficient and stamping speed and with the decrease of die fillet radius. In a word, in order to improve the drawing-bulging forming limit of hemispherical parts, the suitable parameters are selected as blank holder force 20 kN, die fillet radius 12 mm, friction coefficient 0. 125 and stamping speed 2000 mm · s^-1 Finally, process testing shows that the simulation result is consistent with the experimental result, and the drawing-bulging forming limit is improved greatly.