DE3321957A1 - METHOD AND DEVICE FOR EXTRUDING HOLLOW PROFILES - Google Patents

Abstract

1. A process for extrusion of hollow profiles, which show graduated cross sections along the profile length, whereas an ingot (1) with the extrusion die (2) is brought into a recipient (3) and is pressed over a mobile mandrel (8) by means of a hollow punch (12) through the die (4), characterized in that at the beginning of the extrusion, the mandrel (8) enters the closed ended die (4) ; that during the compression of the cross section enlargement, the hollow punch (12) allows the material to be extruded to flow over the mandrel (8) until the closed ended die (4) is completely filled ; that the recipient (3) with the mandrel (8) and the die (4) rebounds towards the drum holder, whereas a profiled pressure ring (10) in the direction of extrusion is positioned behind the die (4) into extrusion position and the cross section of the hollow profile is extruded by moving the hollow punch (12) ; that after the compression of the cross section enlargement and after moving of the recipient (3) with the die (4), the closing plate (5) is moved across the extrusion direction and is exchanged against a pressure plate (7) with profiled opening and, that the die (4) is in one part.

Description

AKTIENGESELLSCHAFT -:: "-"'-' - "' ν ϊα

- - - Α-463

Method and device for extrusion of hollow profiles

The invention relates to a method and a device for extrusion of hollow profiles, the outside of the Profile length have stepped cross-sections, with a bar introduced with the press disk in a recipient and is 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 the production of hollow profiles, in particular from aluminum _, is equipped with several matrices that can be detached one behind the other and that allow the extrusion of offset profiles. To achieve hollow profiles that are offset from the inside, the tip of the mandrel is offset in the die area and is arranged to be longitudinally movable in the press ram. In order to simultaneously be able to produce hollow profiles that are offset from the outside over the length of the profile, several detachable matrices arranged one behind the other are provided, which are held and released by abutments that can move obliquely outward.

The production and use of several detachable matrices arranged one behind the other is complicated and expensive. The division of the matrices can lead to dimensional inaccuracies and premature wear.

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

According to the invention, the object is achieved with a method for Extrusion of hollow profiles of the type mentioned solved in that at the start of pressing the mandrel 8 in a The die 4 closed at the end moves in, so that when the cross-sectional enlargement is upset, the hollow punch 12 lets the material to be pressed flow over the mandrel 8, until the closed die is completely filled that the recipient 3 with the mandrel 8 and the die 4 in the direction The cylinder holder moves back, whereupon a profiled pressure ring 10 is brought in the pressing direction behind the die in the pressing position and the hollow profile cross-section is pressed out by advancing the hollow punch 12.

It is advantageous that a hollow bar 1 in the recipient 3 is introduced, which has a temperature gradient in the pressing direction having. The temperature gradient is to be designed in this way; that the actual pressing temperature when using aluminum materials is between 400 and 56O ° C.

A one-piece die 4 is preferably used in the tool package 14. This allows greater dimensional accuracy and tool stability are guaranteed.

It is also particularly advantageous that the mandrel at the start of pressing. 8 through the die 4 in a central locking position the closed. Pressure plate (locking plate 5) retracts. The centric In spite of the high compression pressures, the closed position ensures that the outer contour of the hollow profile remains absolutely true to size.

After upsetting the enlarged cross-section and after When the recipient 3 is moved with the die 4, the closure plate 5 is moved transversely to the direction of the strand and against it replaced a pressure plate 7 with a profiled opening. The transverse mobility makes the process faster of the pressing process, so that also quench-sensitive alloys, especially those mentioned below Alloys AlMgSi, AlMgMn, AlCuMg, AlZnMgCu.

A device for carrying out the method described above consists of an extruder with a press cylinder, Press ram, recipient, movable mandrel and at least one die. According to the invention, the device is characterized in that that between the die 4 and the counter holder 15 is a tool package 14, consisting of closure plate 5 and pressure ring 10 is arranged, which is displaceable transversely to the extrusion direction is.

It is advantageous that the die 4 can be moved together with the recipient 3. This will make the tool movements decreased and the pressing speed increased.

It is also of particular advantage that a centering bore 9 for the mandrel 8 is provided in the closure plate 5. This allows profiles to be produced with high dimensional accuracy that have a degree-free surface.

The method according to the invention also enables use a one-piece, rotationally symmetrical die 4. This reduces the tool costs and the strength curve positively influenced within the die.

An essential feature of the device according to the invention is that the mandrel 8 has at least one mandrel shoulder in the pressing direction 13, which brings about a cross-section reduction compared to the mandrel exit diameter of 30 to 50%. With this Formation of the mandrel shoulder, any contours of a hollow profile can be produced with high degrees of deformation. 0

Due to the special construction of the tool package according to the invention 14, the die 4 is mounted in a centerable manner in the tool holder 6 or in the pressure ring 10. This is especially important because if the tool is changed without being able to be centered, no dimensional accuracy of the profiles is guaranteed.

The object is achieved according to the invention by what is stated in the claims specified features solved. The particular advantages of the method according to the invention are as follows:

1. The undivided die enables very high compression pressures with very long tool life,

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

3. The accelerated process makes it possible to use alloys that are sensitive to quenching To use procedures,

4. Compliance with high dimensional accuracy,

5. Production of burr-free profiles,
6. any outer contour,

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

8. Alloys of the type: Pure-Al, AlMgSi, AlMg, AlMgMn, - AlCuMg, AlZnMgCu etc. can be used.

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

Fig. 1 = Partial cross-section through a strand according to the invention

and pipe press after inserting the hollow billet before the start of pressing,

Fig. 2 - Partial cross-section according to Fig. 1 after the mandrel has been retracted,

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

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

Fig. 5 = Partial view of the extruder when extruding the pipe.

The method according to the invention begins with an ingot, preferably a hollow bar 1, with the press disk 2 in the Recipient 3 is introduced. 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 6. The tool package with the profiled pressure plate 7 is located stand by.

In Fig. 2, the retraction of the dome is now shown in the die. The mandrel 8 is centered in a centering bore 9 of the closed pressure plate 5 and cannot migrate even at high, eccentrically acting pressing pressures.

3 shows the upsetting of the flange at the beginning of the pressing process. The material to be pressed flows over the mandrel 8 and completely fills the insert tool, the die 4, which is closed by the closure plate. The pressing pressures are absorbed by the pressure plate 7 and the pressure ring 10.
5

The tool change is shown in FIG. The recipient moves with the mandrel 8 and the die 4 back in the direction of the moving beam 11 or in the direction of the cylinder holder. The previously in The waiting position tool package with the profiled D pressure plate 7 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 (12)

UNITED ALUMINUM-WERKE ": · .. ·:::". ·., "Sunday, June 14th, 1983 Aktiengesellschaft::: *: ::: *:: .a-C463 Patent claims: 1. Process for extrusion of hollow profiles, which over the profile length have stepped cross-sections, wherein a bar with the press disk is introduced into a recipient and is pressed through a die over a movable mandrel with the aid of a hollow punch, characterized in that that at the start of pressing the mandrel (8) moves into a die (4) closed at the end, that when upsetting the cross-sectional enlargement of the Hollow punch (12) the material to be pressed over the Lets the mandrel flow 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 in the pressing direction behind the die in the pressing position and the hollow profile cross-section is pressed out by advancing the hollow punch (12). 2. The method according to claim 1, characterized in that a hollow bar (1) is introduced into the recipient (3), which has a temperature gradient in the pressing direction. 3. The method according to any one of the preceding claims, characterized in that when using bars made of aluminum nium alloys the pressing temperature is between 400 and 500 ° C. jr.-r "'-2- 332Ί957 4. The method according to any one of the preceding claims, characterized in that a one-piece die (4) is used will. 5. The method according to any one of the preceding claims, characterized in that when Preß'beginn the mandrel (8) through the The die (4) moves into a centerable locking position of the closed pressure plate (locking plate (5)). 6. The method according to any one of the preceding claims, characterized in that after upsetting the cross-sectional enlargement and after the process of the recipient (3) with the die (4) the closure plate (5) is moved transversely to the strand direction and against a pressure plate (7) is replaced with a profiled opening. 7. Device for performing the method according to one of the preceding claims, consisting of an extruder with press cylinder, press ram, recipient, movable mandrel and at least one die, characterized in that a tool package between the die (4) and the counter holder (15) (14), consisting of closure plate (5) and pressure ring (10), is arranged, which is transverse to the extrusion direction is movable. 8. Apparatus according to claim 7, characterized in that the die (4) can be moved together with the recipient (3) is. ) 9. Device according to claims 7,8, characterized in that that a centering hole (9) for the mandrel (8) is provided in the closure plate (5). 10. Device according to claims 7-9, characterized in that a one-piece, rotatxonssymetrische die (4) is used will. _ T - 11. Device according to claims 7-10, characterized in that the mandrel (8) in the pressing direction at least has a mandrel shoulder (13). 12. Device according to claims 7-11, characterized in that the die (4) in the tool holder (6)
or is mounted so that it can be centered in the pressure ring (10).