EP2670541B1 - Indirect extrusion press and method for indirect extrusion - Google Patents

Description

The invention relates to an indirect extrusion press and a method for indirect extrusion according to the preamble of the independent claims (see e.g. JPH0241714 ).

In the indirect pressing of raw metal blocks, for example made of copper, brass or corresponding alloys, the forming process to form the pressed product takes place with the formation of a shell, for example to prevent impurities on the surface of the block to be deformed from getting into the finished pressed product. In this case, a tool head, which comprises a die, is kept smaller in its diameter than the inside diameter of a block receiver that a shell with a wall thickness of about 0.2 to 2.0 mm remains on the inside wall of the block receiver, as is also shown, for example, in FIG the EP 0 224 115 B1 is revealed. In the case of other materials, for example aluminum, the formation of a shell can be correspondingly advantageous. Another example of an indirect extrusion press is in US Pat DE 22 37 276 A1 disclosed.

A distinction must be made here between direct and indirect pressing processes, whereby in the case of direct pressing with a press ram and the metal to be reshaped in the same direction, larger pressed products can usually be produced. In the case of indirect pressing, in which the pressing ram, known as the indirect ram, and the material are guided in opposite directions, fewer frictional forces occur, since the material does not need to be displaced relative to the block pick-up. As a rule, however, only smaller pressed products can be produced with indirect pressing, since the pressed product has to be removed through the indirect die.

To reduce material stresses in the indirect punch, the suggests DE 101 31 901 A1 propose to screw a clearing ring onto the indirect punch and relieve it with a lock nut or to fasten a wear plate and / or a die using socket pins that are shrunk into corresponding holes in the indirect punch. The disadvantage here, however, is the fact that to remove the shell, because of the releasable but form-fitting connection, a dismantling and assembly effort must be made, whereby the set-up times of such an extrusion press are extended disadvantageously.

It is therefore the object of the present invention to minimize the set-up times of an indirect extrusion press in which a shell is formed from residual material during pressing.

In order to achieve this object, indirect extrusion and methods for indirect extrusion with the features of the independent claims are proposed.

An indirect extrusion press with a tool head comprising a die and arranged on an indirect punch can be characterized in that the tool head tapers towards a stripping plane after a shear ring having a shear edge or after a clearing ring having a shear edge. In this case, the stripping plane is generally oriented perpendicular to the pressing direction and, depending on the specific implementation of the present invention, can be designed in front of or behind the tool head or else cutting the tool head.

In contrast to the indirect extrusion press, as it is in the DE 101 31 901 A1 is disclosed and in which the tool head expands in the area of a wear plate belonging to it, on which it can be separated from the indirect punch, in the direction of the stripping plane made possible by the separation, in this way a simple and reliable stripping of the outside of the Tool head accumulating shell can be guaranteed by the tool head. Depending on the specific implementation, the shell then initially remains in front of a corresponding clearing ring and is only removed after the tool head has been removed, or the shell is stripped off together with the tool head when the tool head is removed and only then stripped from the tool head.

The design of the tool head with a diameter that tapers in the direction of a stripping plane can, depending on the specific implementation of the present invention, also facilitate simple assembly and disassembly of the tool head from the indirect punch, which by means of the taper, which is preferably designed as a cone, is particularly easy and detachable with the Indirect stamp can be connected and detached again when the tapered outside is used as a contact and centering surface to the indirect stamp. Thus, there is only a form-fitting connection between the tool head and the indirect punch, and further fastening means can be dispensed with. Also, due to the design of the above-mentioned cone, a shell formed on the tool head from a material residue or material film of the pressed material can be pulled off by pulling the tool head out of the extrusion press and there is no friction on the surface of the tool head designed as a cone to prevent removal.

This formation of an outer surface of the tool head, which tapers in the direction of a stripping plane, enables a very simple, safe and quick removal of the shell formed on the tool head and a shear ring or clearing ring located on the tool head, which accordingly preferably has a complementary surface with the Tool head is connected, favor, in contrast to the aforementioned implementation, the shell can be pulled from the tool head instead of pulling the tool head from the shell. In this case, the tool head can remain on the indirect die, which pulls the tool head away from the shell in order to release the shell.

In this context, alternatively or cumulatively to the above features, an indirect extrusion press with a tool head comprising a die and arranged on an indirect punch can be characterized by a shell chamber tapering in the direction of a stripping plane. The same advantages mentioned above for the tool head also result in this embodiment, since dismantling of the tool head is particularly easy if the shell chamber of the tool head is filled with a tool material and, if the tool head is not designed, would prevent it from being dismantled , such as this, for example, by the arrangement after the DE 101 31 901 A1 is the case in the area of the shell chamber wall formed by the wear plate of the tool head and widening towards the stripping plane.

In an advantageous embodiment, the clearing ring, the shear ring or both rings can be arranged around the tool head in a radially outer circumference. At the same time, the clearing ring, the shear ring or both rings can also be arranged so as to be removable. This results in On the one hand, an advantageous dismantling option and simple maintenance, in that the two rings, the clearing ring and the shear ring, can be designed as replacement parts and in that it is easier to remove material residues from the tool head, since the overall arrangement of the clearing ring, shear ring and tool head can be separated from one another.

Accordingly, an indirect extrusion press with a tool head comprising a die and arranged on an indirect punch can be characterized in that the tool head comprises a clearing ring and a shear ring, each of which is detachable from the tool head and preferably delimits the shell chamber.

In a different, alternative but not claimed solution, an indirect extrusion press with a tool head comprising a die and arranged on an indirect punch is characterized by a clearing ring and a shear ring, which are formed integrally with one another, with a shell chamber between the clearing ring and the shear ring is trained. Such a tool head can be removed as a whole when the shell chamber is full by simply attaching a new tool head. After removal, a shell can then be removed from the tool head in a separate work step without hindering the pressing process. Such a removal can easily be implemented mechanically and therefore very quickly in order to quickly prepare the indirect extrusion press for the next pressing process.

Such a process can be further simplified in that the structural unit consisting of the clearing ring and shear ring forming the shell chamber is connected to the remaining indirect extrusion press or to the indirect punch via a surface that tapers in the direction of a stripping plane, so that, as before As set out above, self-centering can easily take place, which considerably facilitates or enables the machine conversion to be carried out in the first place.

In all of the aforementioned cases, tapering takes place preferably conically or in the form of a conical surface, since this results in a rotational symmetry which, in particular, makes assembly considerably easier and can also be carried out simply by machine, for example by means of a manipulator.

In order to solve the problem at the outset as an alternative or cumulative to the above features in an equally advantageous but not claimed manner, an indirect extrusion press with a tool head comprising a die and arranged on an indirect punch is proposed, which is characterized by the fact that the size of a shell chamber, which is arranged behind a shear edge of the tool head, is selected such that the shell material can be received by at least two blocks of material in the shell chamber. It goes without saying that if it is possible to keep the thickness of the shell as small as possible, significantly more than two material blocks, for example 10 or more material blocks, can be processed one after the other with an appropriate shell size without having to remove the shell in between. The set-up times of the indirect extrusion press are thus reduced even further, in that the shell material does not have to be removed from the shell chamber after each individual pressing cycle. Two blocks of material can be processed almost immediately one after the other in the extrusion press.

The clearing ring can advantageously be used to thin out the shell produced during pressing to such an extent that a large part of the shell remains in the shell chamber and the material residue or material film emerging from the extrusion press in the pressing direction has a minimal thickness.

A method for indirect extrusion, in which a block of material is pressed through a die encompassing a tool head to form a shell, can also be characterized in that the tool head and shell are pulled from one another in order to remove the shell. In particular, in deviation from the procedure according to the EP 0 224 115 B1 , in which a complex twisting takes place, the material of the shell can be removed much faster as a result.

The drawing is preferably already carried out in the indirect extrusion press, which saves set-up times considerably. The removal can also take place outside, which is just as time-saving, especially if a new tool head is inserted during the latter and the press can be operated again with the new tool head while the shell and tool head are being separated.

This removal can be done on the one hand by the fact that the shell remains in the indirect press and the tool head or parts of it, such as a shear ring, pulled from the shell and the indirect stamp. This pulling off can also take place, for example, in that the shell is pulled off the tool head or parts thereof.

In an advantageous embodiment of the method, after removal, when the tool head has been removed from the interior of the shell, the shell can be separated, preferably sheared, from a material film remaining in the indirect extrusion press. It is immediately apparent that the removal of the tool head with the die located in it enables complete accessibility to the shell, whereby the shell can be removed quickly and easily from the extruder, for example by a shear knife.

Here it is immediately apparent that by removing the shell from the tool head, the tool head can remain in the extruder and thus there is also the possibility of pressing a subsequent, newly pressed strand seamlessly onto the old strand. Furthermore, the handling when removing the shell is improved, since now only the shear ring has to be removed from the tool head in order to get to the shell.

On the other hand, the entire tool head can also be pulled off and removed from the shell, preferably without a clearing ring, so that easy shearing off is made possible.

In this context, but also as an alternative to the above method, a further method for indirect extrusion is proposed, in which a block of material is pressed through a die encompassed by a tool head to form a shell, in order to solve the problem at the outset in a manner not claimed, which is characterized by the fact that at least two blocks of material are pressed before a shell chamber is freed from the shell. As already stated above, it can be seen that removing the shell after pressing at least two blocks of material minimizes the set-up times. Particularly in an extrusion press, the quality of the extruded profile produced can advantageously be increased if the set-up times are so minimal that, due to the immediately successive processing of two blocks of material, a remainder of the first block of material does not have the opportunity to cool down too much and the subsequent second block of material together with The rest of the first block of material can be processed with better seams. In this respect, it will be possible - within limits - to produce very large workpieces with a largely homogeneous quality.

For an alternative or cumulative but not claimed solution of the above-mentioned problem, an indirect extrusion press with a tool head comprising a die and arranged on an indirect punch is proposed, the indirect extrusion press being characterized by a clearing ring designed as an expanding ring. This clearing ring can expand due to its flexibility due to its design as an expanding ring and thus nestle against an inner wall of an inner liner of the indirect extrusion press and advantageously minimize the gap arising between the clearing ring and the inner liner. It can be seen that as a result, a material film passing through this gap is formed as minimally as possible.

The clearing ring can interact with the tool head for the aforementioned purpose, a particularly advantageous embodiment of the indirect extrusion press resulting when the clearing ring is operatively connected to an axially adjacent assembly via a conically inwardly facing surface. The mentioned assembly arranged next to the clearing ring can be the mentioned tool head or also the indirect punch. The clearing ring is advantageously arranged axially between the tool head and the indirect punch, as a result of which the tool head transmits a pressure to the clearing ring and this pressure spreads the clearing ring by means of the conical surfaces through the force diversion.

Since the clearing ring can advantageously be removed particularly easily due to the conically inwardly facing surface, set-up times and costs for replacing the clearing ring are also minimized here. In particular, it is advantageous if the clearing ring is designed to be removable from the indirect punch. It is immediately evident that the indirect punch is subject to the least possible wear, since the component subject to wear is represented by the clearing ring.

In this context, an alternative or cumulative method for indirect extrusion is proposed, in which a block of material is pressed through a die encompassed by a tool head to form a shell and the method is characterized in that at least one The clearing ring used to form a shell is expanded during pressing and is de-expanded when a block pick-up is retracted.

It is also particularly advantageous for this method if the force required for spreading is taken from the pressing pressure.

As already explained further above, the shell emerging from the extruder can be thinned very strongly by means of the expanded clearing ring, so that only a minimal material film emerges from the extruder. The use of the pressure to expand the clearing ring has the particular advantage that the expanding force is only exerted on the clearing ring when the clearing ring is used to thin out the shell. The drop in the pressing pressure when the block receiver moves back also reduces the friction, since the expansion ring is simultaneously despread.

Usually, in indirect extrusion, workpieces of finite length are pressed, with a workpiece change taking place at the latest when the block is changed, in that, before the subsequent block of material is fed in, material residues are removed, in particular from the die, which can be achieved, for example, by turning, as after the EP 0 224 115 B1 , or can be done by shearing. This means that the material that is still in the die and that has already been pressed can simply be removed or falls out of the die.

If the die has an antechamber, then material can remain in the antechamber, even if the rest of the material residues, such as, for example, a material residue located in front of the die or a shell, are removed. In this way, the area in which impurities or imperfections may occur due to the boundary between the two material blocks can be minimized compared to a row of material blocks over the entire diameter of the block receiver. The remaining material in the antechamber also holds the workpiece that has already been pressed in position until the next pressing process begins.

If the prechamber becomes smaller in the pressing direction, a particularly intimate connection of the material of two successive material blocks can take place at a very short distance, so that the area of impurities or defects caused by the change of the material blocks can be further minimized.

Depending on the specific requirements of the finished product, an endless workpiece can be provided in this way if the impurities or defects are caused by the change of the material blocks are conditioned, can be tolerated in terms of quality. Otherwise, these points can be cut off afterwards, whereby even with conventional workpieces, the start and end areas may have to be cut off so that the loss of material usually remains within acceptable limits. By connecting the workpieces via a block change, complex guide mechanisms within the indirect punch, with which workpiece beginnings and workpiece ends are guided within the indirect punch, can also be dispensed with.

As an alternative or cumulative to the above-mentioned method, a method for indirect extrusion is not claimed, in which a block of material is pressed through a die encompassed by a tool head to form a shell and which is characterized by the fact that a shell chamber used to accommodate the shell is lubricated.

This shell chamber is preferably lubricated with graphite. Boron nitrite, silicone or grease or salt water or brine can also be used for this purpose.

The lubrication of the shell chamber also reduces the set-up times of the extrusion press, in that the tool head can be better withdrawn from the shell formed after pressing has taken place, or the shell can otherwise be removed more easily from the tool head. This can be done in the indirect extrusion press or outside of it.

It goes without saying that the features of the solutions described above or in the claims are also advantageous independently of one another for an extrusion press and, if necessary, can also be combined in order to be able to implement the advantages cumulatively.

Figur 1

eine schematische Detaildarstellung einer Strangpresse mit einem Werkzeugkopf mit einem integrierten Scherring und einem separaten Räumring zur Erläuterung des technologischen Zusammenhangs;

Figur 2

eine schematische Detaildarstellung einer Strangpresse mit einem Werkzeugkopf mit einem einstückigen Führungs- und Räumring zur Erläuterung des technologischen Zusammenhangs;

Figur 3

eine schematische Detaildarstellung einer erfindungsgemäßen Strangpresse mit einem Werkzeugkopf mit einem separaten Räumring und einem separaten Scherring:

Figuren 4 bis 11

ein Prozessverlauf beim Rüsten in schematischer Einzelschrittdarstellung für die Anordnung nach Figur 1;

Figuren 12 bis 15

ein Prozessverlauf beim Rüsten in schematischer Einzelschrittdarstellung für die Anordnungen nach Figur 3;

Figuren 16 bis 21

eine Detailansicht des Prozessverlaufes beim Rüsten für die Anordnung nach Figur 3; und

Figur 22

eine Detaildarstellung einer Matrize in schematischem Schnitt.

Further advantages, aims and properties of the present invention are explained with the aid of the following description of exemplary embodiments, which are also shown in particular in the attached drawing. In the drawing show:

Figure 1

a schematic detailed representation of an extrusion press with a tool head with an integrated shear ring and a separate clearing ring to explain the technological relationship;

Figure 2

a schematic detailed representation of an extrusion press with a tool head with a one-piece guide and clearing ring to explain the technological relationship;

Figure 3

a schematic detailed representation of an extrusion press according to the invention with a tool head with a separate clearing ring and a separate shear ring:

Figures 4 to 11

a process sequence during set-up in a schematic single-step representation for the arrangement after Figure 1 ;

Figures 12 to 15

a process sequence during set-up in a schematic single-step representation for the arrangements Figure 3 ;

Figures 16 to 21

a detailed view of the process flow when setting up for the arrangement Figure 3 ; and

Figure 22

a detailed representation of a die in a schematic section.

A first embodiment of an indirect extrusion press 1 with a die 19 and a tool head 5 is shown in FIG Figure 1 has a shear ring 20 integrated in the tool head 5. Furthermore, a clearing ring 16 is arranged between an indirect punch 2 of the indirect extrusion press 1, against which the tool head 5 including the die 19 is pressed.

The clearing ring 16, designed as a separate component, interacts with a shell chamber 24 arranged radially around the tool head 5 in order to collect a remainder of the material block 12 flowing past the shear ring 20 in this shell chamber 24.

Like the shear ring 20, the clearing ring 16 is located within the indirect extrusion press coaxially, but with little play, to a block receiver 3.A first remainder of the material block 12 arrives after sheared off through the gap formed on an inner bush 22 of the block receiver 3 a shear edge 21 arranged on the shear ring 20 into the shell chamber 24. After the material residue located in this slim chamber 24 reaches the clearing ring 16, a large part of this material residue is retained in the shell chamber 24 by means of shearing off at the shear edge 17. In this shell chamber 24, a shell 15 is thus created from the first part of material residue during the pressing.

A second part of the material residue that passes the clearing ring 16 or the shear edge 17 remains adhering to the inner bushing 22 as a thin material film 26 in the further course. In the ideal case, the wall thickness of the material film 26 is so small that this remaining material film 26 can be removed from the indirect extrusion press 1 with very little effort. In particular, the material film 26 can automatically tear when the block pick-up 3 moves back into a set-up position, whereby removal is possible without further tools or with only little support. Likewise, if necessary, the wall thickness of the remaining material film 26 can be so small that it can remain on the inner bush 22.

The volume of the shell chamber 24 is dimensioned in such a way that the material residue sheared off at the shear edge 17 of the clearing ring 16 only fills the shell chamber 24 after at least two successive pressing processes. In addition, if its volume is made larger, an edge 25 for latching a tool remains freely accessible in the shell chamber 24 for removal of the tool head 5.

For secure seating of the tool head 5 during the pressing of a pressed product 4, it has at least one conical surface 23 which, in the embodiment described, interacts with the clearing ring 16 and, in this exemplary embodiment, spreads the clearing ring 16. To spread the clearing ring 16, it can, but does not have to be, slotted, whereby a closer contact of the shear edge 17 on the inner bushing 22 can be ensured. It is immediately apparent that this design of the clearing ring 16 reduces the material film 26 to a minimum. In a different embodiment, the clearing ring 16 is also in operative connection with the indirect punch via a conical surface, whereby good centering and, with suitable coordination of the conicity or the contact surfaces between inner punch 2 and clearing ring 16, the expansion can be increased.

A second embodiment of an indirect extruder 1 according to Figure 2 has a clearing ring 16 connected in one piece to the shear ring 20, the shear ring 20 and the clearing ring 16 forming the shell chamber 24 in their space axially to the pressing direction. In contrast to the embodiment according to Figure 1 the indirect punch 2 of the indirect extrusion press 1 now acts directly on the tool head 5 and not on the Räumring 16, the Räumring 16 and the shear ring 20 connected to this Räumring 16 are mounted on a conical surface 23 of the tool head 5.

An angle of the conical surface 23 formed in relation to the axial pressing direction of the indirect punch is shown in the exemplary embodiment according to FIG Figure 2 according to the corresponding angle Figure 1 opposite. If the details are suitably dimensioned, this configuration ensures that the clearing ring 16 and possibly also the shear ring 20 expand when a pressed product 4 is pressed. In this context, as pointed out again, that a spread clearing ring 16 and / or a spread shear ring 20 in a Moving back the indirect plunger 2 is again despread and dismantling of the two rings 16, 20 can be done with less effort.

In a third, to the embodiment according to Figure 2 A similar embodiment is also the one in Figure 3 shown indirect extrusion press 1 designed, in this case the shear ring 20, the clearing ring 16 and the tool head 5 are formed separately. The shell chamber 24 is now formed by the two rings 16, 20 and an outer surface 23 of the tool head 5 that tapers slightly conically towards the shear ring 20. As can be seen immediately, this embodiment offers the advantage that only the shear ring 20 needs to be pulled off to remove the shell 15 from the tool head 5.

In the embodiment according to Figure 1 For pressing the pressed product 4 in the indirect extrusion press 1, with the block pick-up 3 retracted, a block of material 12 is positioned by means of a block loader 13 between the tool head 5 and a locking piece 8 coaxially to the indirect punch 2 and coaxially to a direct cylinder 27, as in Figure 4 shown.

The direct cylinder 27, which is also mounted in a frame 28, acts via a direct stamp 11 on an associated locking piece 8. By means of a holder 9, which is also mounted in the frame 28 via a pressure plate 10, the arrangement of the locking piece 8 and the direct stamp 11 guided within the frame 28 and the pressure generated by the closing of the block receiver is absorbed.

After the material block 12 has been positioned, the indirect punch 2 is as shown in FIG Figure 5 can be seen to move against the material block 12 so that it is between the Tool head 5 and the locking piece 8 is clamped and the block loader 12 can be guided out of the indirect extruder 1.

Then the block pick-up 3 is moved to the holder 9, whereby the material block 12 receives a completely closed housing, and the pressing process begins with the progressive stroke of the indirect punch 2 in the block pick-up 3, as shown in FIG Figures 6 and 7th evident. Due to the onset of volume reduction within the block receiver 3, the press product 4 is manufactured by means of the die 19 until the indirect punch 2 has moved into the block receiver and only a small amount of pressed residue 7 remains from the material block 12.

After retracting the locking piece 8, it will continue to be seen from Figure 8 As can be seen, the pressed residue 7 is separated from the tool head 5 and from the pressed product 4 by means of a movable shear blade 6.

That by means of the Figures 4 to 8 The pressing process explained is run through at least a second time after the first pressing process. It is immediately apparent that with a corresponding volume of the shell chamber 24, more than two pressing processes can be carried out until the shell chamber is filled to the maximum. It should also be pointed out that the press residue 7 does not necessarily have to be removed by means of the shear blade 6 between two pressing processes. In addition to the procedure described above, it is also possible to place a newly inserted block of material 12 directly on the remaining pressed residue 7 and to continue the pressing process. At least, however, the removal of the pressed residue 7 is necessary when the shell 15 has to be removed, this possibly being done together with the removal of the shell 15.

Removing the shell at the after Figure 1 described embodiment of the tool head 5 takes place, as from Figure 9 can be seen, by means of a gripping arm or manipulator 14, which engages on the edge 25 of the tool head 5 and this, as continues Figure 10 can be seen, from the indirect punch 2 or from the clearing ring 16 releases. By means of a further retraction of the block pick-up 3, the shell 15 is completely exposed, after which the shear blade 6 attacks again and separates the shell 15.

After the shell 15 has been removed from the shell chamber 24, the manipulator 14 moves back to its original position, and a new block of material is fed into the indirect extruder 1 by means of the block loader 13 to restart a pressing process, as shown Figure 11 can be seen.

The equipping of an indirect extrusion press 1 in the exemplary embodiment after Figure 3 slightly deviates from this. With the block pick-up 3 retracted, the manipulator 14 first moves into the indirect extrusion press 1 and pulls the shear ring 20 off the tool head 5. The shear blade 6 then engages the exposed shell 15, although in this context a double or multi-edged shear blade 6 is used, and the block receiver 3 is displaced against the pressing direction, as a result of which the shell 15 gripped by the shear blade is withdrawn from the tool head 5 becomes. The tool head 5 is then moved out of the block pick-up 3 again in order to place the shear ring 20 on the tool head 5 again by means of the manipulator 14.

That by means of the Figures 12 to 15 explained equipping the indirect extruder 1 is in the Figures 16 to 21 shown again in detail. Here, after the block pick-up 3 has moved back and the pressed residue 7 has been sheared off by means of the shearing knife 6, the tool head 5 is moved out, completely exposing the shell chamber 24. During the separation of the pressed residue 7 and the exposure of the shell chamber 24, the shell 15 is also broken from the pressed residue 7 so that the shear ring 20 is completely exposed and can be pulled off the tool head 5 without hindrance. As already explained above, the shearing knife 6 then grips the shell 15 while the tool head 5 is retracted, so that the shell 15 is now completely exposed and can be removed from the indirect extrusion press 1. It is also conceivable at this point that the shell can be removed from the indirect extrusion press 1 by means of the manipulator 14 or an alternative gripping tool.

The in Figure 2 The illustrated embodiment is changed with similar devices, the unit of the clearing ring 16 and shear ring 20 being withdrawn as a whole from the tool head.

Following the removal of the pressed residue 7 and the shell 15 from the shell chamber 24, in all the present exemplary embodiments a better During the pressing process, the surface of the tool head 5, in particular the conical surfaces 23, is sprayed with a lubricant or lubricant, in this case with graphite 29. The application of the graphite 29 facilitates the removal of the shear ring 20 from the tool head 5 during the subsequent setup, but it may not be possible either.

The set-up of the indirect extrusion press 1 is then ended by placing the shear ring 20 on the tool head 5 again, and a further pressing process in the configuration described above is initiated.

As already explained above, if necessary, a newly inserted block of material 12 can be placed directly on the remaining press residue 7 in order to press out a workpiece more or less continuously. In order to keep the area that may have impurities due to the boundary between the two blocks of material 12 as small as possible, the in Figure 22 The die 19A shown are used, which has an antechamber 30 on the side of the material block, with only the residual material then remaining in the antechamber 30 during shearing and being used for the connection with the subsequent material block 12.

List of reference symbols:

1 Indirect extrusion press 17th Shear edge of the clearing ring 16 2 Indirect postmark 18th Manipulator jaw 14 3 Block pick-up 19th die 4th Press release 19A die 5 Tool head 20th Shear ring 6th Razor knife 21 Shear edge of the shear ring 20 7th Press residue 22nd Inner socket of the block picker 3 8th Locking piece 23 conical surface 9 holder 24 Shell chamber 10 printing plate 25th Edge for latching the clamping jaw 18 and delimiting the shell chamber 24 11 Direct stamp 12th Material block 26th Material residue / material film 13th Block loader 27 Direct cylinder 14th manipulator 28 frame 15th Bowl 29 graphite 16 Clearing ring 30th Antechamber

Claims (6)

1. Indirect extrusion press (1) with a toolhead (5) comprising a die (19) and arranged on an indirect stem (2), characterized in that the toolhead (5), a clearance ring (16) and a shearing ring (20) are configured separately and a shell chamber (24) for a shell (15) is formed by the shearing ring (20), the clearance ring (16) and an outer surface (23) of the toolhead (5) tapering slightly conically in the direction of the shearing ring (20), wherein the shell (15) can be removed from the toolhead (5) in this direction.
2. The indirect extrusion press (1) according to claim 1, characterized in that the clearance ring (16) and/or the shearing ring (20) are arranged in a removable manner radially around the outer circumference of the toolhead (5).
3. The indirect extrusion press (1) according to one of the preceding claims, characterized by a die (19A) with a front chamber (30).
4. Method for indirect extrusion, in which a block of material (12) is pressed through a die (19) comprised by a toolhead (5), thus forming a shell (15), characterized in that the toolhead (5), a clearance ring (16) and a shearing ring (20) are configured separately and a shell chamber (24) for a shell (15) is formed by the shearing ring (20), the clearance ring (16) and an outer surface (23) of the toolhead (5) tapering slightly conically in the direction of the shearing ring (20), and in that, for the removal of the shell (15), the toolhead (5) and shell (15) are separated from each other in this direction.
5. The method for indirect extrusion according to claim 4, characterized in that, for the removal of the shell (15), the shearing ring (20) is removed from the toolhead (5) first and, subsequently, the shell (15) is removed from the toolhead (5).
6. The method for indirect extrusion according to claim 4 or 5, characterized in that, after the removal of the toolhead (5), the shell (15) is separated, preferably shorn off, from a material film (26) remaining in the indirect extrusion press (1).

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