The introduction of rod and tube extruder
A rod and tube extruder comprising: a press frame formed by a cylinder beam and a counter beam connected thereto; a holder carriage linearly displaceable in the press frame a holder; a billet gripper concentrically surrounded by the holder and adapted to transport a billet that is introduced by means of a loader and that is to be pressed in a press position in front of a die associated with the counter beam, the holder being supported in and spaced from the holder carriage; webs on both sides of the holder at the center of the press and projecting diametrically outward; respective retaining blocks for the holder carriage forming inwardly open recesses in which the respective webs engage; linear guides on the press frame; and respective guide shoes linearly shiftable along the guides and carrying the retaining blocks.
The invention relates to a rod and tube extruder comprising a press frame formed by a cylinder beam and a counter beam connected thereto in which a linearly displaceable holder carriage is provided, the holder carriage having a holder that concentrically encloses a billet gripper and transports a billet that is introduced by means of a loader and that is to be pressed in a press position in front of a die associated with the counter beam, the holder being held therein by air in a self-supporting manner with respect to the holder carriage. By use of adjusting cylinders a running beam and the holder carriage that is movable on the guides of the press frame may be displaced on the die or the counter beam, the billet gripper being inverted above the billet. Corresponding to the advancement of the holder carriage together with the billet gripper, the axially movable swivel arm is moved on the shaft until the billet is clamped between the pressing stamp or mandrel and the counter beam or die fastened in a holder. The holder carriage is moved by means of lateral cylinders.
During the extrusion pressing, high compression stresses are present in the billet that allow a high degree of deformation. A prerequisite for this high degree of deformation is a low yield stress of the material being shaped. For this reason pressing is performed only at high temperatures. It is known to support the holder and running beam on support surfaces that are angled in such a way that their extension intersects the press axis or is close thereto, thus being oriented to the press axis, in order to prevent the central position of the receiver and the pressing stamp from being influenced by thermal expansion caused by changes in temperature. For central alignment of the receiver and the pressing stamp on the press axis, for the base frames that support the guides for the holder carriage together with the holder and the running beam, supports are provided between the guides and base frame that are horizontally adjustable on the base frame transverse to twin screw extruder, and with respect to which the guides are vertically adjustable.