Production of silencer or catalytic converter box with connection with smaller section at at least one end to integrate it into exhaust pipe of vehicle

摘要

A tube (3), in particular a cylindrical tube, is closed at the end (2, 5) of the box (1) and the connection (11, 12) is made at the level of or near the closed end of the tube by perforation and drawing out. The end of the tube is closed by fluoturning or by deep stamping. After the end is closed, a reinforcing cone is introduced from the other end to define a heat insulating layer of air at the end of the tube. After one end is closed and the connection stub is made, the other end is closed by fluoturning after introduction of a catalyst or the parts of a silencer and a second stub is formed by perforation and drawing near the other closed end of the tube. The drawing is done from inside or outside the tube. The fluoturning operation to close at least one end of the tube is done hot, heating by induction. The drawing operation is assisted by an expandable rotating mandril introduced into the tube after perforation. At the other end of the tube, a cone opening into a smaller section connection stub is formed by fluoturning or is welded on.