| 摘要 |
A method of producing holes shaped by thickness in sheet parts, in which a hole is made in a sheet workpiece, into which a profiled mandrel is inserted, and then a profile in the hole is made due to plastic deformation of the hole wall by the mandrel, which during deformation of the hole wall moves in the longitudinal (axial) direction. During punching the hole in the sheet billet along its contour a conical collar is formed, a profiled (e.g., threaded) surface in the hole is obtained due to radial flow of material at circular twisting and upsetting the conical collar on the profiled mandrel, in the case the hole diameter decreases and metal accumulated in the collar fills the cavities, such as a thread of the profiled mandrel, and then caulking the collar is made between the movable punch and fixed support. |
