| 摘要 |
PURPOSE: To obtain a machine for forming a Pittsburg type duct continuously from a sheet material in which high productivity can be attained by bending first through third side faces sequentially after forming a male part at the front fringe of the material and finally performing a work for jointing male and female parts continuously. CONSTITUTION: When a metal sheet fed out from an uncoiler and shaped flatly is introduced into a forming unit 18, front edge of the material is fed onto a table 20 by the distance at the male part of a Pittsburg seam and then the material is grasped. A male part 54 is formed by turning a bend beam 42 by about 90 deg. and then the material is released and fed by a specified amount before being grasped and bent similarly to form the first side face of the duct part. Similarly, the material is fed by a specified amount at a time to form second and third side faces 58, 60 sequentially. Subsequently, the material is advanced over the edge part of V-shaped dies 24, 32 and Z-shape is formed as a preliminary female part which is then combined with the male part to form a duct. |
