DE8317710U1 - Device for extruding hollow profiles - Google Patents

Description

Bonn, 13.07.1987 *: .· J J .· *,.* .·

A-463 vs ::·:::*::;

Device for extruding profiles. Description:

The invention relates to a device for extruding hollow profiles which have graduated cross-sections on the outside over the length of the profile, whereby a billet with the pressing disk is introduced into a recipient and pressed through a die via a movable mandrel with the aid of a hollow punch.

According to DE-OS 21 23 528, a metal extrusion press for producing hollow profiles, in particular made of aluminum, is equipped with several consecutively removable dies that enable the pressing out of offset profiles. To produce hollow profiles offset on the inside, the mandrel is offset at its tip in the die area and is arranged so that it can move longitudinally in the press ram. In order to be able to produce hollow profiles offset on the outside over the length of the profile at the same time, several consecutively removable dies are provided, which are held and released by abutments that can be moved diagonally outwards.

The production and use of several detachable dies arranged one behind the other is complicated and time-consuming. The division of the dies can lead to dimensional inaccuracies and premature wear.

The object of the present invention is to avoid the disadvantages described and to develop a device that enables a simple, low-wear production of stepped hollow profiles with high dimensional accuracy.

This object is achieved in that the device described at the beginning consists of an extrusion press with a press cylinder, press stamp, recipient, movable mandrel and at least one die. The device is characterized according to the invention in that a tool package 14 consisting of a closure plate 5 and a pressure ring 10 is arranged between the die 4 and the counterholder 15 and can be moved transversely to the extrusion direction.

It is advantageous that the die 4 can be moved together with the recipient 3. This reduces the tool movements and increases the pressing speed.

It is also particularly advantageous that a centering hole 9 for the mandrel 8 is provided in the closure plate 5. This allows profiles to be produced with high dimensional accuracy and with a burr-free surface.

The device according to the invention also enables the use of a one-piece, rotationally symmetrical die 4. This reduces tool costs and has a positive effect on the strength profile within the die.

An essential feature of the device according to the invention is that the mandrel 8 has at least one mandrel shoulder 13 in the pressing direction, which brings about a cross-sectional reduction of 30 to 50% compared to the mandrel starting diameter. With this design of the mandrel shoulder, any desired contours of a hollow profile can be produced with high degrees of deformation.

Due to the special design of the tool package 14 according to the invention, the die 4 is mounted in a centerable manner in the tool holder 6 or in the pressure ring 10. This is particularly important because if the tool is changed without the ability to center it, the dimensional accuracy of the profiles cannot be guaranteed.

It is expedient that at the start of pressing the mandrel 8 moves into a die 4 that is closed at the end, that when upsetting the cross-sectional enlargement the hollow punch 12 allows the material to be pressed to flow over the mandrel 8 until the closed die is completely filled, that the recipient 3 with the mandrel 8 and the die 4 moves back in the direction of the cylinder holder, whereupon a profiled pressure ring 10 is brought into the pressing position behind the die in the pressing direction and the hollow profile cross-section is pressed out by advancing the hollow punch 12.

It is also advantageous that a hollow bar 1 is introduced into the recipient 3, which has a temperature gradient in the pressing direction. The temperature gradient is to be designed in such a way that the actual pressing temperature is between 400 and 560 ^° C when using aluminum materials.

Preferably, a one-piece die 4 is used in the tool package 14. This can guarantee greater dimensional accuracy and tool stability.

It is also particularly advantageous that when pressing begins, the mandrel 8 moves through the die 4 into a central locking position of the closed pressure plate (locking plate 5). The central locking position ensures that the outer contour of the hollow profile remains absolutely dimensionally stable despite high pressing pressures.

After upsetting the cross-sectional enlargement and after moving the recipient 3 with the die 4, the closure plate 5 is moved transversely to the strand direction and replaced with a pressure plate 7 with a profiled opening. The transverse movement enables an accelerated course of the pressing process, so that even alloys that are sensitive to quenching, in particular the alloys mentioned below AlMgSi, AlMgMn, AlCuMg, AlZnMgCu.

The particular advantages of the device according to the invention are as follows:

1. the undivided die enables very high pressing pressures with very long tool life,

2. Reduction of the tool movement and therefore accelerated pressing speed Ior accelerated .process of the entire pressing process,

3. the accelerated process makes it possible to use alloys that are sensitive to quenching for such a process,

4. Compliance with high dimensional accuracy,

5. Production of burr-free profiles,

6. any external edging,

7. the pressing temperatures are in the range of 400-560 ⁰ C when using Al alloys,

8. Alloys of the type: pure Al, AlMgSi, AlMg, AlMgMn, AlCuMg, AlZnMgCu and others can be used.

The invention is explained in more detail below using an exemplary embodiment. Shown are:

Fig. 1 => Partial cross section through an inventive

Extrusion and tube press after inserting the hollow billet before starting pressing,

Fig. 2 = Partial cross-section according to Fig. 1 after retraction of the dome,

Fig. 3 = Partial cross-section of the extrusion press during the upsetting of the flange,

Fig. 4 = Principle diagram when changing the pressure plate,

Fig. 5 = Partial view of the extrusion press during extrusion of the pipe.

According to the invention, a bar, preferably a hollow bar 1, is introduced into the recipient 3 with the pressing disk 2. The insert tool, consisting of an undivided die 4, is supported in the pressing position against a closed pressure plate (closure plate 5) and is fastened in a tool holder. The tool package with the profiled pressure plate is in the waiting position.

• t · f *

Fig. 2 shows the insertion of the mandrel into the die. The mandrel 8 is centered in a centering hole 9 of the closed pressure plate 5 and cannot move even at high, eccentrically acting pressing pressures.

fi' Fig. 3 shows the plunge of the flange at the beginning of the pressing

!·■'■ process. The material to be pressed flows over the mandrel 8

_f j and fills the bin set closed by the closure plate

I tool, the die 4, completely. The pressing pressures are

p by the pressure plate 7 and the pressure ring 10.

I The tool change is shown in Fig. 4. The recipient 3 ', with the mandrel 8 and the die 4, moves back in the direction of the moving beam 11 or in the direction of the cylinder holder. The tool package with the profiled pressure plate 7, which was previously in the waiting position, now moves transversely to the extrusion direction into the pressing position.

Fig. 5 shows the pressing out of the pipe by advancing the hollow punch 12 in the recipient 3.

Claims (6)

Protection&naprash: 1. Device for extruding hollow profiles, consisting of an extrusion press with a press cylinder, press ram, recipient, movable mandrel and at least one die, characterized in that a tool package (14) consisting of a closure plate (5) and pressure ring (10) is arranged between the die (4) and the counterholder (15), which can be moved transversely to the extrusion direction. 2. Device according to claim 1, characterized in that the matrice (4) can be moved together with the recipient (3). 3. Device according to claims 1-2, characterized in that a centering hole (9) for the D< rn (8) is provided in the closure plate (5). 4. Device according to claims 1-3, characterized in that a one-piece, rotationally symmetrical die (4) is used. 5. Device according to claims 1-4, characterized in that the mandrel (8) has at least one mandrel shoulder (13) in the pressing direction. 6. Device according to claims 1-5, characterized in that the die (4) is mounted in a centerable manner in the tool holder (6) or in the pressure ring (10).