The results show that when the pre-hole is reverse-conical and its diameters are dmax=12 mm, dmin=10 mm, acceptable nozzle sizes can be obtained after hole flanging on thick-wall cylinders.

• 研究结果表明:预加工孔型为反锥形,且尺寸为dmax=12mm,dmin=10mm时,厚壁筒体翻孔后的接管尺寸符合要求。