Method for the manufacture of pipes by means of extrusion as well as for providing one flange on at least two pipes, and device to carry out the said method

摘要

The invention is related to the integral extrusion of at least two pipes and a common flange to an extruding device and to a flange with at least two pipes integral with said flange. The method is characterized in that said pipes are extruded simultaneously while a common flange is formed at the same time, during which extrusion the material of the starting workpiece (blank), flowing under pressure, is forced, at a certain distance before the beginning of the extrusion openings for the pipes, to flow axially and radially into and through a transient space situated between said openings and the space reserved for the flange. By this method a flange is obtained integral with at least two pipes of equal cross-sections and wall thickness along their whole length said method is carried out by a device comprising an extruding device with a reciprocating plunger in the extrusion space, said extrusion space being closed off, at the side facing the plunger, by an extrusion plate provided with the required number of extrusion openings, a preferably stationary mandrel extending through each of these openings, said device being characterized by a member which can be placed in the extrusion space between the extrusion plate and the starting workpiece (blank), said member limiting the transient space and forming a gap together with the outwardly directed side of each mandrel.