| 摘要 |
PURPOSE:To work efficiently a manifold pipe of which the outside surface over the entire part is approximately circular and which has good quality with less man-hour for working by pressing plural pieces of gathered pipes over the entire part with dies then crushing the pipes with dies having successively smaller inside diameters. CONSTITUTION:A part of upper and lower dies 4, 5 and 7, 8 form die surfaces 6, 9 of a circular shape as a whole when clamped in the case of producing a manifold pipe such as an exhaust pipe or the like of an automotive engine. The inside diameters of the surfaces 6, 9 are made smaller with the surface 9. The diameter of the surface 9 is first considered and pipes 1 of the diameter and number conforming thereto are disposed between the dies 4, 5 having the max. inside diameter and are grasped by the dies 4, 5. The dies 4, 5 are pressed to each other until the end faces at the edges of both dies contact with each other thereby crushing and deforming the pipes 1 over the entire part and forming an assemblage 10. The assemblage is then crushed and deformed in the same way as mentioned above between the dies 7 and 8 and a manifold pipe 11 in which the four pipes 1 contact face to face with each other and the outside diameter over the entire part is approximately circular is obtd. |
