EP3253567B1 - Powder press having a cone-shaped substructure - Google Patents

Description

The present invention relates to a powder press with a conical lower punch, in particular a substructure, as well as a method for operating a powder press, a method for setting up the powder press and a compact produced using the proposed powder press. The powder press is used in particular to produce bodies that are subsequently to be sintered. In particular, metallic powders but also ceramic powders can be processed. The compact is preferably a green compact that is subsequently sintered.

A press design is crucial for determining what kind of parts can be pressed in what time and how. EN 10 2014 003 726 The applicant has developed a press for producing dimensionally stable green compacts, in which the tool structures used have a shape optimization to compensate for elasticity between individual tool levels. This requires a certain amount of technical effort in the design and manufacture of the tools.

The EP 1 764 173 A2 discloses a powder press according to the preamble of claim 1.

The object of the present invention is to provide a simplified press structure which can be manufactured using conventional methods and which shortens tool changes and setup time.

This object is achieved with a powder press having the features of claim 1, with a method having the features of claim 22, with a method for setting up having the features of claim 26, with a pressed part having the features of claim 27 and with a computer program product having the features of claim 28. Advantageous developments and embodiments emerge from the respective subclaims, whereby one or more features from the description as well as from the figures can be combined to form further embodiments.

A powder press with a tool structure is proposed, wherein the tool structure has a conical base with nested lower punches, wherein each lower punch has a longitudinal extension, in particular a cylindrical longitudinal extension, which is guided in a die, wherein at least two longitudinal extensions of the lower punches are each adjoined by an area with a conical widening, wherein the conical widenings can be guided into one another, wherein the area of the conical widening has a conically widening inner and outer wall that is longer than the longitudinal extension. Preferably, the lower punch forms a length that is otherwise only possible with a connected structure. Preferably, the lower punch has an extension at its end of such a size that, for example, a punch holder can be connected directly to this end of the lower punch.

The longitudinal extension runs parallel to a travel axis of the powder press. The longitudinal extension is preferably arranged concentrically around the travel axis of the powder press. The longitudinal extension is realized in a stamp, for example, by a head piece.

The lower punch preferably forms the substructure. This means that the lower punch extends conically as a hollow cone axially and radially in such a way that a foot of the lower punch, for example, rests directly on a pressure plate or is in direct contact with a drive. In this way, for example, the use of an adapter plate for each lower punch can be saved. It is preferred if the pressure plate is integrated into the punch. For this purpose, it can be provided, for example, that a stamp foot has a width and thickness, which enables a direct connection of a drive. A further embodiment provides that a connection for the pressure plate is provided at the base of the stamp, preferably a connection that functions via a relative rotation between the pressure plate and the stamp.

Furthermore, the above and following explanations do not only apply to lower punches. Rather, one or more upper punches can be designed or constructed in the same way. According to a further idea of the invention, such upper punches, such as the proposed lower punches, can be pursued as an independent idea or in combination with the lower punches. The same applies to conical punches with conical structures. In the following, designs, features and further advantages are explained in more detail using an application to lower punches, but without restricting this to lower punches. Rather, the same applies to upper punches and combinations of such upper and lower punches. In the following, only the term punch is used here. This then refers to both upper punches and lower punches. An upper structure, in turn, relates to the structural design towards a pressure plate of the associated upper punch. A substructure relates to the structural design towards a pressure plate of the associated lower punch. The same as for the upper and lower punches is also possible for a punch with a conically widening structure, which will be discussed in more detail below.

A further development, for example, provides that all lower punches, except for an innermost lower punch, have a widening area that widens in a conical shape, in particular cone-shaped or bell-shaped.

A further embodiment provides that at least two, preferably all of the respective lower punches, if necessary without the innermost lower punch, are provided with a conical extension, which has a corresponding conical inner and outer walls of the conical widening.

Preferably, the combination of the region with conical widening and conical extension can be longer than the longitudinal extent. In particular, a substructure is formed in this way. The substructure is shaped like a hollow cone.

Furthermore, it can be provided that the cone angles of nestable lower punches or lower punches with extensions, along which the conical widening and the conical extension extend from a press axis, are at least approximately equal. It is therefore preferred that a respective cone angle of the lower punches remains at least approximately equal from the inside to the outside. However, a deviation of the cone angles from one another is also possible, with the cone angles preferably spreading further from the inside to the outside.

A constant cone angle over the radial extension has the advantage that the influence of bending or the risk of buckling when the pressing forces are transmitted is greatly reduced, but the stress distribution is very even across the extension. Preferably, bending stresses in a longitudinal direction can be greatly reduced using the proposed solution.

Furthermore, it is provided, for example, that the nested lower punches do not touch in the area of their expansion, ie with the respective inner wall of one punch and the opposite outer wall of the opposite punch, preferably not touching at least for the majority of the expanding extent. The same applies, for example, to an expanding punch with a conically expanding Structure and adjacent punch with adjacent, expanding structure. For example, it is provided that contact between the punches only occurs over a region of a longitudinal extension of the punches, preferably only along an extension of 10 to 30 mm, furthermore preferably only in a region of a die of the powder press. According to a further development, it is provided, for example, that a longitudinal extension of a punch has a so-called clearance. A clearance means that the previous dimension of the diameter of the longitudinal extension of a punch is changed to such an extent that there is no contact with an adjacent punch, where, however, there is otherwise contact in the area of the die. The contacting area in the die serves as a guide, in particular as an upper guide for lower punches and as a lower guide for corresponding upper punches.

Another design of the powder press provides that in a common end position the feet of the respective lower punches end at different heights.

It is preferred if the lower punches sliding into one another have approximately the same elasticity in the conically widening region compared to one another. For example, it can be provided that the lower punches sliding into one another with a conical structure have approximately the same elasticity compared to one another.

It is also possible for the feet of the lower punches to end in a common end position at the same height along a plane. In particular, the proposed solution makes it possible for an outermost lower punch or an outermost lower punch with a conically widening structure to deflect approximately the same as an inner lower punch or a lower punch with a conically widening structure. For this purpose, for example, the elastic modulus as well as the respective construction must be designed accordingly to set a desired level of rigidity. Preferably, rigidity can be increased through design measures. This makes it possible to control the high frictional forces that occur, for example, on the outermost punch, and the resulting changes in length due to a material getting warmer and the associated change in friction during operation. In particular, it is possible to create constructive compensation and, moreover, to approximate the deflection, even with different lengths, such as with the inner punch, since its great length can lead to greater changes in length and greater deflection than with shorter punches. It should also be taken into account here that, for example, it is possible to combine conical, long lower punches without additional conically widening structures and lower punches with conically widening structures. The latter preferably have no contact with the adjacent punch in the area of their expansion, or at least no contact with the adjacent punch for the majority of their extension.

Another design provides that an outermost lower punch with structure deflects at least approximately the same as an inner lower punch with structure. The advantage of this design arises during pressing and in particular when relieving the pressed material, as this enables simplified relief across all punches without the green compact breaking.

According to a further idea, which can be independent or dependent on the above and the following, a design method is proposed for determining a constructive solution for the conical lower punches or conical lower punches with conical structures that can be moved into one another. In this case, a first calculation is carried out for each lower punch or connected structure, checking whether a termination criterion such as the respective elasticity can be determined according to a predefined termination criterion, otherwise at least one parameter is changed until at least this one termination criterion is met. In this way, depending on the specification, the corresponding interlocking lower punches or lower punches with structure can be calculated and, for example, designed to achieve an approximate, overall uniform elasticity.

Preferably, it is further provided that a respective cone angle of the lower punches increases from the inside to the outside, while the respective longitudinal extension of the lower punches or the longitudinal extension of the lower punches with the respective structures decreases from the inside to the outside.

Furthermore, it is preferably provided that a stamp holder is directly connected to the conical widening. The conical widening of the respective lower stamp preferably widens so much that an associated stamp holder is flush with the lower stamp on the outside. A further development provides that, alternatively or additionally, there is flushness on the inside. In this case, it can be provided that the conical widening of the lower stamp merges into a cylindrical section, wherein the cylindrical section has fastening means for a stamp holder, preferably detachable fastening means. For example, twist locks are preferred, which in particular make screwing superfluous. It is also preferred if a stamp holder is connected directly to a lower stamp by means of a bayonet lock. In particular, it is possible for a connection between the stamp holder and the lower stamp to take place without a pressure plate and clamping plate.

With a bayonet lock, it has been found that it is advantageous if the bayonet lock has more play radially than axially. The radial play can be 10 to 50 times larger.

According to a further embodiment, the stamps, with or without a structure, have such an expanding width that a drive, in particular one or more hydraulic cylinders, can be arranged on them directly and/or via an adapter plate. Preferably, a base of the stamp or structure is so stable that direct contact is also possible. For this purpose, for example, the end of the structure or stamp opposite the longitudinal extension can have a collar.

With regard to the structure of the stamps, it can be provided that at least one upper stamp and/or one lower stamp are made in one piece. It is also possible that at least one upper stamp and/or one lower stamp are made in several parts.

Furthermore, it is provided that the stamp units sliding into one another are each provided with a different ratio of the length of the head piece to the length of the widening area.

According to a further idea of the invention, which can be pursued independently or dependently on the above idea, a method for operating a powder press is proposed in which punch units sliding into one another are moved as described above and/or below, wherein monitoring in the form of a control or regulation is used which compensates for different springs of the punch units sliding into one another when a pressed workpiece is relieved of pressure. The compensation is preferably electronically compensated. In particular, compensation can be carried out when the lower punches are moved via a position control. The method is preferably used to produce a pressed part comprising metal powder. For example, it can be provided that one punch springs while another punch moves when the pressed green part is relieved of pressure. A further embodiment provides that when During setup, compensation is not carried out due to different springs of the respective stamps or stamps with structures. Instead, compensation is carried out exclusively by position detection and position control or regulation, without any prior adjustment with regard to the elasticity differences.

According to a further idea of the invention, which can be pursued independently or independently of the above idea, it is proposed to install a set of stamp units that slide into one another in a powder press, as described above and also in more detail below, whereby these stamp units are first inserted together and then fastened together, i.e. are set up. This eliminates the need for individual insertion and individual alignment as before. A joint setup can also be carried out afterwards. During setup, the filling position, the transfer position, the compaction, the relief and the demolding are preferably checked and finely adjusted with all stamp units together. A stamp unit also comprises the proposed conical stamp as well as the conical stamp with a conical structure.

One advantage of the proposed powder press is that a compact can be produced that has a consistent density along a cross-section of the compact. It is also possible to produce complex shapes, since the movement of the punches prevents the green compact from breaking due to their almost identical elasticity. Preferably, elasticity is designed in such a way that under operating conditions, a respective compression or rebound of 5/10 mm or less occurs across all punches.

Furthermore, it is proposed to provide lower punches of a powder press which slide into one another and have at least a plurality of lower punches as described above or below.

• Kraftfußoptimierung durch geometrisch einfache, trichterförmige Werkzeuggestaltung, besonders bei rotationssymmetrischen Werkzeugen einsetzbar;
• Reduzierter Aufwand in der Konstruktion durch Verzicht auf die Gestaltoptimierung;
• Verzicht auf additive Herstellverfahren, da die einfachen Werkzeugelemente in der Regel auf Standard-Werkzeugmaschinen durch spanabhebende Verfahren hergestellt werden können;
• Verkürzung der inneren Werkzeugelemente, auch unter Inkaufnahme der Verlängerung der äußeren Werkzeugelemente;
• Verzicht auf einen vollkommenen Elastizitätsausgleich: Der Ausgleich wird in der Regel nach wie vor durch die Positionsregelung der Maschine vorgenommen.

According to one embodiment, the present invention also enables a simplified tool structure while at the same time dispensing with conventional accessories, in particular pressure plates, with the aim of, for example:

• Force foot optimization through geometrically simple, funnel-shaped tool design, particularly suitable for rotationally symmetrical tools;
• Reduced design effort by eliminating shape optimization;
• No additive manufacturing processes are used, as the simple tool elements can usually be manufactured on standard machine tools using machining processes;
• Shortening of the inner tool elements, even if this means lengthening the outer tool elements;
• No complete elasticity compensation: The compensation is usually still carried out by the position control of the machine.

The tool structures can be made either in one piece or, using connection technology, in multiple parts, consisting of a head piece, connecting element and base piece.

Furthermore, the scope of the disclosure regarding a possible design of sub-stamps that can be moved into one another also refers to the EN 10 2015 201 784.2 of the applicant and the EN 10 2015 201 785.0 of the applicant. With regard to a possible manufacturing process, reference is made in the disclosure to the EN 10 2015 201 775.3 the applicant.

In particular, from the point of view of uniform pressure application and, above all, pressure relief across the width of the pressed part, it is advantageous for the lower punches to be constructed in a rotationally symmetrical manner. Another embodiment provides for non-rotationally symmetrical, in particular asymmetrical punches with their punch feet on rotationally symmetrical structures. The punch feet are preferably also rotationally symmetrical. For example, an asymmetrical foot stiffness can also be provided, which serves to create a balance between a load side and a less loaded side of the asymmetrical punch.

In particular, a lower punch and/or upper punch of a powder press as described above or below is proposed.

In particular, a structure for connection to a lower punch and/or upper press of a powder press, as described above or below, is proposed.

According to a further idea of the invention, which can be pursued independently as well as dependently on one of the above and following ideas, a computer program product with computer program code means that can be executed on a computer system for carrying out a method as described above or below is proposed.

Fig. 1:

Einen Ausschnitt aus einer Pulverpresse, wie sie aus dem Stand der Technik bekannt ist,

Fig. 2:

Einen beispielhaften, schematischen Adapteraufbau ohne Werkzeug und Unterbau aber mit Adapterplatten und Säulenstruktur aus dem Stand der Technik,

Fig. 3:

Eine beispielhafte, schematische Ansicht von ineinander verfahrenen Unterstempeln, wie sie aus dem Stand der Technik bekannt sind,

Fig. 4:

Eine erfindungsgemäße, beispielhafte, schematische Ausgestaltung von Unterstempeln und angeschlossenen Aufbauten im Vergleich zur Darstellung aus Fig. 3,

Fig. 5:

Zeigt eine beispielhafte schematische konstruktive Lösung mit sich erweiternden Unterstempeln gemäß der vorgeschlagenen Erfindung,

Fig. 6:

Eine Gegenüberstellung der unterschiedlichen Federung bzw. Elastizität die Nutzung der unterschiedlichen Systematik nach Fig. 3 und nach Fig. 4, und

Fig. 7:

Zeigt eine vorgeschlagene Pulverpresse in schematischer Ansicht.

Fig. 8:

Zeigt die Pulverpresse aus Fig. 7 in einer Vergrößerung zur Darstellung von Anschlägen.

Further advantageous features and embodiments are evident from the following figures. One or more features from one or more figures as well as from the above and following description can be combined to form further embodiments. In particular, the figures serve to explain the invention and are not intended to limit it. Comments and statements relating to lower punches or lower punches with a conical structure are not limited to lower punches but serve the exemplary clarification. The respective features and designs can also be used for proposed upper punches or proposed upper punches with additional conical structure of a powder press. Shown are:

Fig.1:

A section of a powder press as it is known from the state of the art,

Fig. 2:

An exemplary, schematic adapter structure without tools and substructure but with adapter plates and column structure from the state of the art,

Fig. 3:

An exemplary, schematic view of interlocking lower stamps, as known from the prior art,

Fig.4:

An exemplary schematic design of lower stamps and connected structures according to the invention in comparison to the representation from Fig.3 ,

Fig.5:

Shows an exemplary schematic constructive solution with expanding lower punches according to the proposed invention,

Fig.6:

A comparison of the different suspension or elasticity the use of the different systems according to Fig.3 and after Fig.4 , and

Fig.7:

Shows a proposed powder press in schematic view.

Fig.8:

Shows the powder press from Fig.7 in an enlargement to show attacks.

Fig.1 shows a section of a powder press 1 as is known from the prior art. This section shows part of a tool 2, although neither a die nor an upper punch or other components of the powder press 1 are shown. An adapter plate structure 3 with a lower punch 4 is shown. A screwed cap 5, a pressure plate 6 and a support ring 7 are used as accessories. A punch base 8 is attached to the pressure plate by means of the cap 5. The structure of the punches shows the necessary size that must be provided for such a powder press. On the other hand, setting up the equipment requires a certain amount of effort, since the caps or clamping plates and pressure plates have to be installed, which is done individually.

Fig.2 shows a state-of-the-art adapter plate structure in a simplified, clear representation. For the upper and lower punches, which are not shown in detail here, an adapter plate must be installed for each punch. One adapter plate after the other can be connected upwards and downwards, for which the respective structure must be moved in the press. This process is very time-consuming and requires a large number of individual parts.

Fig.3 also shows in a simplified sectional view for better clarity a structure known from the prior art with lower punch 9 and connected structures 10. These extend, as in Fig.1 As already shown, essentially along a travel axis of the press. In particular, the respective inner and adjacent outer walls of adjacent punches slide on each other, since with such a structure the punches are guided by this.

Fig.4 shows a structure according to the invention with lower punches 11, which have a conical extension, to which respective conical structures 12 are connected, to which a punch holder, for example, can then be directly connected. The structures 12 are connected to the lower punches 11 here via feet 13, which are only shown schematically. It is preferred if, as shown, an angle of the conical extension of the respective lower punch 11 is taken over and continued by the conical structure 12. An exemplary design is an essentially conical-straight design of the extension. A bell-like design of the extension is also possible. As shown, contact only occurs in the area of the lower punches, and there only in the area of their longitudinal extension 11. 1. Otherwise, the walls protrude from one another.

Fig.5 shows an exemplary, schematic, constructive solution in which the lower punches 13 shown move into one another and an overall conical expansion results. Conical structures 14 are connected to the punch feet, the conical shape of which extends to the adapter plates 15 shown.

Fig.6 shows a comparison of the respective elasticity with the system Type 1 from Fig.3 and on the other hand with the System Type 2 from Fig.4 As shown, it is possible to bring the corresponding properties of the respective lower punches or lower punches with the structure proposed very close to each other. This can lead in particular to the fact that, for example, the press control does not need to provide for elasticity compensation between the punches during movement, especially during unloading.

Fig.7 shows a powder press 17 according to the invention in a schematic, simplified view. For better clarity, the individual components of the powder press 17 are provided with reference numerals in the figure and explained below. The section shown is not flat, but partially rotated for clarity. This also makes those components visible which would otherwise not be visible if arranged around a circumference of the powder press 17. A crosshead 18 of the powder press 17 is connected to a hydraulic main cylinder 19 for a pressing force. However, another drive can also be provided, for example a worm drive. Furthermore, the crosshead 18 is firmly connected to two guide columns 20 shown. An upper main plate 21 is movable, for example at least two diagonally opposite hydraulic cylinders 22 being used per level. Each level preferably has hollow cones 23 as a conical extension of a structure or a punch, each with at least two rigid arms 24 with guide bearings 27, each related to two diagonally opposite columns. A die plate 25 with the die 26 is held movable. This allows a withdrawal process to be used. A drive for this can also be provided in a base plate. The machine base plate 28 of the powder press 17, also called the foundation plate, has at least two diagonally opposite cylinders, preferably hydraulic cylinders 29 per level, which are connected to a hollow cone 30, one per tool-stamp level. The machine base plate 28 carries the hydraulic cylinders 29 and is firmly connected to the columns 31. The hydraulic cylinders 29 can, for example, be completely or partially replaced by another drive, for example by an electric spindle drive. The lower punches 32 with connected structures in the form of the hollow cones 30 are also shown. In the area of the substructure, the lower punches or the hollow cones 30 are also supported by rigid arms 33. It should also be noted that for the sake of simplicity, only the sections of the shaping tools and the conical structure parts are shown hatched.

According to a further idea, which can be independent as well as dependent on the above and the following, a guide of the stamp units proposed, which have a first contacting area in the die as a guide, in particular as a transfer for lower punches and as a lower guide for corresponding upper punches. A second guide takes place as an external guide of the hollow cones as shown and explained above. In this way, a defined mobility along a powder press axis can be created.

Fig.8 shows a section of the illustration from Fig.7 . For better clarity, however, the hydraulic cylinders have been omitted and various stops 34 are shown instead. These can be used according to one embodiment. A stop can be arranged stationary or adjustable.

Claims (28)

1. Powder press (1, 17) having a tool structure which has a conical substructure and/or superstructure with punches (4, 11, 32), upper and/or lower punches, nested in one another, wherein each punch (4, 11, 32) has a longitudinal extent, in particular a cylindrical longitudinal extent, which is guided in a die (26), wherein at least two longitudinal extents of the punches (4, 11, 32) are adjoined in each case by a region with a conical enlargement, wherein the conical enlargements are able to be guided one in another, characterized in that the region of the conical enlargement has a conically expanding inner and outer wall, which are longer than the longitudinal extent.
2. Powder press (1, 17) as claimed in claim 1, characterized in that, apart from an innermost punch, in particular a lower punch, all punches (4, 11, 32) have an enlarging region which expands in a conical, in particular cone-shaped or bell-shaped manner.
3. Powder press (1, 17) as claimed in claim 1 or 2, characterized in that a conical extension is located on at least two, preferably all respective punches (4, 11, 32), possibly without the innermost punch, arranged as a structure, said conical extension continuing a corresponding conical inner and outer wall of the conical enlargement.
4. Powder press (1, 17) as claimed in claim 3, characterized in that the combination of the region with a conical enlargement and a conical extension is longer than the longitudinal extent.
5. Powder press (1, 17) as claimed in claim 3 or 4, characterized in that a cone angle at which the conical enlargement and the conical extension extend away from a press axis is at least approximately the same.
6. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that, in a common end position, feet (8, 13) of the respective punches (4, 11, 32) end at different heights than one another.
7. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that, compared to one another, the punches (4, 11, 32) that slide in one another have approximately the same elasticity in the conically expanding region.
8. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that, compared to one another, the punches (4, 11, 32), in particular lower punches, with a conical structure that slide in one another have approximately the same elasticity.
9. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that feet of the punches (4, 11, 32) end at the same height along a plane in a common end position.
10. Powder press (1, 17) having upper and/or lower punches that slide in one another as claimed in one of the preceding claims, characterized in that an outermost punch (4, 11, 32) deflects approximately as much as an associated inner punch (4, 11, 32).
11. Powder press (1, 17) having upper and/or lower punches that slide in one another as claimed in one of the preceding claims, characterized in that an outermost punch (4, 11, 32) together with a structure (12, 14) deflects approximately as much as an associated inner punch (4, 11, 32) with a structure (12, 14).
12. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that a respective cone angle of the punches (4, 11, 32) of a superstructure and/or substructure increases from the inside out, while the respective longitudinal extent of the punches (4, 11, 32) preferably decreases from the inside out.
13. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that a respective cone angle of the punches (4, 11, 32) of a superstructure and/or substructure remains at least approximately the same from the inside out.
14. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that a punch holder directly adjoins the conical enlargement.
15. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that the conical enlargement of the respective upper and/or lower punch increases to such an extent that an associated punch holder terminates flush with the upper or lower punch laterally on the outside.
16. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that the conical enlargement of the respective upper and/or lower punch transitions into a cylindrical portion, wherein the cylindrical portion has fastening means for a punch holder, preferably releasable fastening means.
17. Powder press (1, 17) as claimed in claim 16, characterized in that a punch holder is connected directly to a lower punch by means of a bayonet fastener.
18. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that a connection between the punch holder and punch (4, 11, 32) takes place without a pressure plate (6) and clamping plate.
19. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that at least one upper punch and/or one lower punch are produced in one piece.
20. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that at least one upper punch and/or one lower punch are produced in a multipart manner.
21. Powder press (1, 17) as claimed in one of the preceding claims, characterized in that the punch units that slide in one another are provided with in each case a different ratio of length of the head piece to length of the enlarging region.
22. Method for operating a powder press (1, 17) as claimed in one of the preceding claims, in which punch units, upper and/or lower punches, that slide in one another are moved, wherein monitoring in the form of control or regulation is employed, this effecting equalization between different springing behavior of the punch units that slide in one another when the pressure on a pressed workpiece is relieved.
23. Method as claimed in claim 22, characterized in that electronic compensation of a difference in elastic deflection takes place.
24. Method as claimed in either of claims 22 and 23, wherein equalization via position control takes place while the lower and/or upper punches are being moved.
25. Method as claimed in one of claims 22, 23 or 24, characterized in that a compact made of metal powder is created.
26. Setting up of a powder press (1, 17) with a set of punch units according to one of the preceding claims that slide in one another, characterized in that said punch units are first of all installed together and are then jointly set up.
27. Compact produced with a powder press (1, 17) as claimed in one of the preceding claims, wherein a density along a cross section of the compact is constant.
28. Computer program product with computer program code means which are able to be run on a computer system in order to carry out a method as claimed in one of claims 22 to 25.

Images