EP0300149B1 - Device for leading in a profiled bar in a drawing die - Google Patents

Abstract

1. Device having a longitudinally shiftable clamping device (3) for inserting a sectional bar or a sectional tube into a drawing die, characterized by the following features : - in front of a drawing die (1) there is arranged an auxiliary drawing die (4) on the same axis which consists of at least two radially slidable jaws for the formation of a reduced shank diameter of the sectional bar or the sectional tube, respectively : - the longitudinally shiftable clamping device (3) is arranged in front of the auxiliary drawing die (4) ; - the auxiliary drawing die (4) is adjustable by shifting in the drawing direction from a position at a distance from the drawing die to a position directly in front of the drawing die (1), the auxiliary drawing die serving as a guide for the insertion of the shaped sectional bar or sectional tube into the drawing die.

Description

description

The invention relates to a device for inserting a profile bar into a drawing die according to the preamble of claim 1.

Since profiled bars or pipes made of soft metal, for example aluminum or copper, cannot be directly pushed into a drawing die, it is necessary to form a drawbar by machining, but this is associated with material loss.

The task of the innovation consists in a device with which an introduction into the drawing die can be carried out even with rods made of soft metal without loss of material.

This object is achieved by a device with the features according to the characterizing part of the main claim. The subclaims have preferred constructive embodiments.

With the aid of such a device, a drawing bar, which can be inserted into the drawing die without being pushed in, can be formed by a stretching process in the case of profiled bars made of soft metal, with no material loss whatsoever. First, a waisted deformation is formed at a distance from the bar end using a tool, which corresponds to the desired drawing cross section. The rod is then pulled out of the auxiliary drawing die with a clamping device until the end is free, so that the desired drawing bar is formed up to the end of the rod by this drawing process. It is up to you to determine the length of the drawbar, depending on where the forming tool is attached. The pressures to be used during the deformation are limited, since the deformation is limited to a relatively small rod length.

The further invention relates to the special design of a shaping tool, with which rectangular cross sections or square cross sections of any size can be formed and which can thus be used universally. In particular, this tool can be used in a position close to the actual drawing die for guiding the undeformed rod during the actual drawing process.

• Fig. 1 zeigt in einer Seitenansicht eine Vorrichtung nach der Erfindung, im Prinzip, vor Beginn des Arbeitsganges;
• Fig. 2 ist eine entsprechende Ansicht nach der Verformung;
• Fig. 3 zeigt die Stellung der Elemente nach dem Abstrecken;
• Fig. 4 stellt die Vorrichtung nach dem Einführen der Ziehangel in die Ziehmatrize dar;
• Fig. 5 ist ein Schnitt nach V-V von Fig. 1;
• Fig. 6 ist ein Schnitt nach VI-VI von Fig. 2;
• Fig. 7 ist ein Schnitt nach VII-VII von Fig. 4.

In the following an embodiment of the invention is described in more detail with reference to the accompanying drawings.

• Fig. 1 shows a side view of a device according to the invention, in principle, before the start of the operation;
• Fig. 2 is a corresponding view after deformation;
• Fig. 3 shows the position of the elements after stretching;
• Fig. 4 shows the device after inserting the drawing die into the drawing die;
• Fig. 5 is a section on VV of Fig. 1;
• Fig. 6 is a section along VI-VI of Fig. 2;
• FIG. 7 is a section according to VII-VII of FIG. 4.

It is a question of forming a drawing bar on a profile bar 2 with a square cross section and consisting of a soft metal, for example aluminum or copper, suitable for insertion into a drawing die 1, so that this drawing bar can be grasped on the left side by a drawing car. In a first step, a waisted deformation is formed on the bar 2 at a distance from the bar end with the aid of an auxiliary drawing die 4. The waisted deformation of the profile bar 2 has the cross section of the desired drawing bar, in the embodiment a square cross section. When the reduced cross section is formed, a clamping device 3 comes into operation. The two jaws of the clamping device grip the profile bar in front of the auxiliary drawing die 4 and pull the bar through the auxiliary drawing die to the end, a drawing bar 2a being formed by stretching the material. This deformation can be seen in FIG. 3. Then the auxiliary drawing die 4 is set so that the drawing die 2a is released so that it can be inserted into the drawing die using the clamping device 3, as shown in FIG. 4. For further drawing, the auxiliary drawing die 4 can be used as a guide element. For this purpose, it is moved directly in front of the drawing die 1 and the die cross-section is adjusted in accordance with the undeformed rod cross-section, so that guidance is given in front of the drawing die during the further drawing process. The actual drawing process takes place in a manner known per se, by touching a drawing carriage on drawing die 2a to the left of drawing die 1 and pulling the profile bar through the die.

• Fig. 5 zeigt die Einstellung der Backen 4a bei der Einführung des Stabendes.
• Fig. 6 zeigt die Stellung der Backen nach der taillierten Verformung.
• Fig. 7 zeigt ihre Stellung in der Führungsfunktion.

The auxiliary drawing die 4 consists, as can be seen from FIGS. 5 to 7, of four tool parts 4a (deformation jaws) of square or rectangular cross-section in such an arrangement that one jaw wall in each case partly encloses a rectangular space and the other partly abuts the adjacent jaw. With this arrangement, it is possible to move each jaw in two mutually perpendicular directions, whereby any rectangular or square cross-section can be adjusted.

• Fig. 5 shows the setting of the jaws 4a when inserting the rod end.
• Fig. 6 shows the position of the jaws after the waisted deformation.
• Fig. 7 shows its position in the management function.

Claims (2)

1. Device having a longitudinally shiftable clamping device (3) for inserting a sectional bar or a sectional tube into a drawing die, characterized by the following features:

- in front of a drawing die (1) there is arranged an auxiliary drawing die (4) on the same axis which consists of at least two radially slidable jaws for the formation of a reduced shank diameter of the sectional bar or the sectional tube, respectively:

- the longitudinally shiftable clamping device (3) is arranged in front of the auxiliary drawing die (4);

- the auxiliary drawing die (4) is adjustable by shifting in the drawing direction from a position at a distance from the drawing die to a position directly in front of the drawing die (1), the auxiliary drawing die serving as a guide for the insertion of the shaped sectional bar or sectional tube into the drawing die.

2. Device as claimed in claim 1, characterized in that the auxiliary drawing die (4) consists of four square or rectangular jaws (4a) arranged in such a manner that in each case a rectangular interior space is formed with one wall of the jaws and a part of the wall of a jaw rests against the neighbouring jaw.

Images