concaver凹面体concaveadj.凹的n.凹面；凹线；凹形concave circular sa凹面圆锯concave head piston凹顶活塞concave round plane凹底圆刨concave preset lens前置凹面镜concave filiet weld[机] 凹面堆角熔接concaveconvex shape凹凸形状concave motion rule凸图元运动规则concave fillet weld凹角焊concave filler weld凹角焊concave programming凹形规划法