利用上界法推导了冷拔内螺旋凸筋管拔制力计算式。
The formulas of drawing force for spiral internal-ribbed pipe cold-drawing are derived with upperbound method.
该中巢的内孔壁上设有限拉凸筋，张力弹簧抵靠该凸筋的下端。
The inner hole wall of the middle nest is provided with a draw limiting convex rib, and the tension spring contacts the lower end of the convex rib.
理论分析数控椭圆滚压成型时工作台的运动方程，实现成型件无凸筋滚压；
The motion equation of the worktable of the NC ellipse rolling is established , so no-rib rolling is realized.
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