EP2776237B1 - Method and press for pressing a compact from at least two different metal and/or ceramic pulverulent and/or granular materials - Google Patents

Description

The invention relates to a method for pressing a compact, wherein in a die opening of a press at least two upper-side punches are placed on the material and underside and upper side arranged punching dies located therebetween material columns of at least two different metallic and / or ceramic powder and / or press granular materials. The invention also relates to a press and a data carrier with software for carrying out such a method.

Exemplary is off DE 102 54 656 B4 a ceramic powder and / or metal powder press known. This comprises a ceramic powder and / or metal powder press tool with at least one main body, with a plurality of at least two punches, which are arranged in a pressing position from one side immersed in a filled with ceramic and / or metal powder die opening of a die, with a plurality of at least two punch carriers, to each of which one of the punches is attached, wherein at least a part of the punch carrier can be coupled to at least two adjustment drives and wherein the punch carrier are arranged relative to each other and relative to the base body adjustable, and with fixed stop means which arranged are to derive a pressing force at least partially in a Pressendstellung of the punches on the body.

While such presses are driven hydraulically or mechanically, is eg DE 10 2009 049 845 A1 Such a ceramic powder and / or metal powder press known in which a main pressing force with an electric motor drive and a spindle assembly is applied to relatively adjustable components and the powder to be pressed.

EP 1 440 790 A1 and EP 1 457 204 A1 relate to a method for filling a matrix with a filler for producing a stepped compact, in which mutually adjacent powder columns are jointly precompressed during production.

DE 10 2009 042 598 relates to pressing a shaped body with only a single powder, wherein powder material is pre-compressed to a first body, then in the press a second, separately precompressed molded body or a solid part is inserted into a cavity of the first molded body and finally the thus composite molded body is finally compressed.

US 2004/113319 A1 relates to a method in which a shaped body is pressed from different materials. For different production steps, lower press punches are adjusted individually. A body partially manufactured by stamping on the lower side is subsequently displaced uniformly vertically from the lower-side stamps.

The object of the invention is to further develop a method and a press for pressing a compact of at least two different metallic and / or ceramic powder and / or granular materials.

In particular, a speedy pressing even complex structures and material distribution is to be made possible.

This object is achieved by the method for pressing a compact from at least two different metallic and / or ceramic powder and / or granular materials with the features of claim 1 or the device with the features of claim 10 or by the disk with a program solved according to claim 12. Advantageous embodiments are the subject of dependent claims.

Accordingly, in particular, a method for pressing a compact of at least two different metallic and / or ceramic powdery and / or granular materials is preferred in which a first such material is introduced into a die opening of a die, in which at least two upper-side punches in the die opening be placed on the material, at least temporarily, in which the underside and top side arranged pressing die together with intermediate material columns along a pressing direction are adjusted to different heights, in which after lifting the top arranged press die in the die opening, the second material is filled and in the final with the at least two upper-side punches the material is finally compacted.

Under a pressing direction is understood that corresponding movements in or against a filling or pressing force-effective direction. In particular, the pressing direction from top to bottom and / or vice versa.

Under material columns is understood that along the pressing direction above each of the stamp material is, wherein a cross-sectional contour through the material corresponds to a surface contour of a surface of the corresponding press ram. In this case, not only cuboidal material columns can arise, but any contour having material columns, in particular circular or annular columns of material.

Of course, the method is also applicable to more than two materials or on more than two upper and lower side punch. For this purpose, if necessary, appropriate additional steps upstream or downstream.

As far as the bottom and top stamps are described, it is assumed that a conventional press arrangement in which the material is filled from above into the die opening and then pressed from above and below by means of the stamp. Equivalent to this are arrangements in which the pressing takes place in a transverse direction, for example, when the die assembly should be pivoted into a transverse position after filling or if it should be pressed in a transverse position, so that instead of above and below then conceptually right and left side to would be used.

The same applies, of course, for inclinations between these two orientations.

In particular, in such methods, the underside pressure rams are adjusted so far to different heights prior to filling of the first or second material that a free space above the ram is suitable for filling a required for a corresponding compacting body portion powder quantity. In particular, there is thus an adjustment of the fillable spaces for each column of material with individual height.

Equivalent to the use, in particular, of upper-side press punches for adjusting the material columns and for pre-compacting, would also be an insert for specially provided punches, if pressing for final compacting of the pressed body is effected by means of separate press dies in e.g. a separately provided press takes place.

Under the final compression is understood in a known manner that the precompressed compact is compressed as far as it is necessary for its removal from the press and in particular for a subsequent sintering. The final final compression can optionally also be carried out as an independent step, possibly also in another press.

Under the compacts are understood in particular technical compacts of technical ceramics or metal, such as gears.

The adjustment of the underside and top side arranged punch can in particular be carried out together with the material columns located therebetween, to a Contact of the mutually adjacent columns of material is lost. Under the fact that the contact of the mutually adjacent columns of material is lost, it is understood in particular that the adjacent materials are lost to each other binding forces.

In this case, the adjustment of the underside and top side arranged pressing ram can be carried out together with the material columns therebetween until the mutually adjacent columns of material no longer touch each other. The fact that the contact of the mutually adjacent columns of material is lost is preferably understood to mean that the adjacent columns of material are displaced relative to one another in the pressing direction such that at times a lower edge of a column of material is higher than an upper edge of the adjacent column of material. In particular, the adjustment to different heights means that the mutually adjacent stamps are moved differently relative to each other.

In particular, after the contact has been lost, the press punches arranged on the underside and on the upper side can be adjusted, together with the material pillars located between them, into a position in which the second material is filled.

The adjustment to different heights, in particular a / the adjustment for losing the lateral contact of the material columns can be performed independently of an intermediate reaching a subsequent second filling position for the second material.

The adjustment can also take place in an intermediate step beyond the filling position or in a direction opposite to a direction of the following Filling position done. In particular, the adjusting movement for separating the columns of material can therefore, if necessary, be carried out in a first step, even in a direction opposite to the direction of the subsequent filling position, or even beyond the filling position.

According to a further embodiment, the material columns between the underside and upper side arranged press dies can be pre-compressed before a first adjustment relative to each other.

In particular, an embodiment can be implemented in which the material columns are precompressed between the underside and upper side arranged pressing dies, namely during or after a first adjustment of the material columns relative to each other.

Such a pre-compression can be carried out in particular by a specific, preferably freely adjustable value. This avoids that the powder or material of the two columns of material mixed together. In particular, such a mixture is avoided both vertically and horizontally. There is then a clean dividing line between the different materials.

In repeated such steps after filling the second material, the shift of powder or material columns can be moved again. As a result of the fact that the first material is pre-compressed or precompressed, no mixing of the first and the second filled-in and possibly not yet or only partially pre-compacted material occurs.

It is also possible to implement a configuration in which at least one of the lower-side and upper-side punches has an annular configuration or with the inside This allows eg ring-wise filling and pressing in order to use different powders transversely to the pressing direction. For example, it is thus possible to produce toothed wheels which on the outside of the ring gear are made of another, in particular harder material than on the inside thereof.

Also, in the filling positions, it is possible to leave no space above one of the lower-side punches free, so that a subsequent material is not filled over such a puncture and thus this material does not extend over the entire width of the resulting compact.

A device with a die having a die opening, with at least two punches protruding into the die opening, with at least two punches insertable into the die opening at the top, is preferred with a filling device for filling the die opening with at least two different metallic and / or ceramic powders. and / or granular materials and with a control device, wherein the control device is designed and / or programmed for carrying out such a method. This is understood to mean that the process implementation to the control device is designed as a pure interconnection or so-called hardware, with a processor for executing a program as so-called software or as a combination of both.

Such a device is designed in particular as a ceramic and / or metal powder press with press dies as the punches. Equivalent to a ceramic and / or metal powder press is a press for pressing a granular or mixed powder and granular material.

A data carrier with a program stored on it, which is programmed to carry out such a method in such a device, is also preferred. In particular, the data carrier may be an independent transportable storage device or a storage device integrated in the press or its control device.

According to the method, such compacts can be formed on the one hand with high precision from different material layers and on the other hand experience both a clean material separation and a sufficiently high pressing force in the final compression. The production of such compacts is possible without great technical effort at the same time a small amount of time.

Fig. 1

Verfahrensschritte zum Pressen eines Presskörpers aus verschiedenen Materialien in einer Keramik- und/oder Metallpulverpresse und

Fig. 2

weitere Verfahrensschritte bis zum gepressten Presskörper.

An embodiment will be explained in more detail with reference to the drawing. Show it:

Fig. 1

Process steps for pressing a compact of different materials in a ceramic and / or metal powder press and

Fig. 2

further process steps up to the pressed compact.

Fig. 1 and 2 schematically show components of a press for pressing a compact of at least two different metallic and / or ceramic powder and / or granular materials p1 - p3. In time order from right to left from 1 to 11 different times are shown, which during an exemplary Cycle through. In the exemplary pressing cycle, a compact 40 is pressed from three materials p1, p2, p3. However, only two or more than three different materials can be used. The materials p1 - p3 can differ from each other in many different ways. In addition to differentiation by the chemical composition may also be differences in grain size, color or other characteristics.

In the press, a die 20 is arranged, which has a die opening 21. The die opening 21 is used to fill the powdery and / or granular material P1 - p3, in particular ceramic powder and / or metal powder, by means of a filling 26. Under such a material or powder is in a broader sense, a granulate or a mixture of fine-grained To understand powder and granular material.

From below, lower-side punches 22, 23 protrude into the die opening 21 and close the die opening 21 downwards. The lower-side punches 22, 23 are adjustable relative to each other and relative to the die 20 in particular by means of drive means. After filling the powdery and / or granular material P1 - p3 this can be compacted by means of upper-side punches 24, 25 and pressed into the compact 30. For this purpose, the upper-side punches 24, 25 are inserted from above into the die opening 21, wherein the upper-side punches 24, 25 are adjustable relative to each other and relative to the die 20 in particular by means of driving means.

A control device 27 serves to the various drive means, in particular one preferred top-side main press drive 28 and drives for moving individual of the punches 22 - 25 and / or the die 20 to control so that their individual movements run timed suitably.

Such a press can in known manner have a press frame, which consists of two lateral press frame, which are on the top and bottom sides firmly connected to an upper side and a lower-side press frame. The press frame are firmly clamped together to build up a flow of force through them up to the punches 22 - 25 can. To build or apply a pressing force, the press has a press drive, which is arranged, for example, as the top-side main press drive 28 on top of the press frame. About a press drive piston, the pressing force is applied to an upper press tool by the press drive, so that it is adjusted in the direction of the die 20. Due to the applied pressing force, the individual components of the press tools are moved together and clamped against the lower-side press frame. The stamps 22 - 25 press the material to the pressing member 30.

Any drive systems, in particular electric motors, mechanical drives and / or hydraulic drives can be used as drives.

A preferred lower-side tool with, inter alia, the lower-side punches 22, 23 consists of a plurality of individual components. The opposing upper-side tool with, inter alia, the upper-side punches 24, 25 may in principle have a comparable structure, but may also be constructed in a conventional manner or a hybrid form of conventional construction and the construction and the lower side tool. The same applies to Adjustment arrangements for adjusting the single individual components of the tools. In particular, for the method described for producing a compact 30 of different materials p1-p3, the respective opposing bottom and top punches 22-24, 23-25 each have surfaces 22o and bottom surfaces 24u opposite one another with the same outside contour. In other words, the opposing punches 22 - 24, 23 - 25 each have in particular opposite equal pressing surfaces.

In the first illustrated method step 1, a filling of the matrix calculation 21 with the first material p1 is sketched. An upper edge of the die 20 is located here, for example, a piece above an exemplary zero-pressing position h0. The first lower-side punch 22 is raised to a height h1 as an intermediate height of the first lower-side punch 22 for this process step 1. This height h1 is located below the upper edge of the die 20, so that above the first punch 22, a space of the die opening 21 which can be filled with the material p1 is formed. The second lower-side punch 23 is disposed adjacent to the first lower-side punch 22 and further offset from the inside die wall of the die 20 inwardly toward the die opening 21. An intermediate height h2 of the second lower-side punch 23 in the first method step one is, for example, lower than the intermediate height h1 of the first lower-side punch 22. As a result, above the upper side of the second punch 23, a space which can be filled over is formed as the effective die opening 21. By means of the filling device 26, the first material p1 is filled into the space above the punches 22, 23 and preferably smoothed at the level of the top of the die 20. In principle, can the opposite inner wall of the die 20 are already right next to the second lower-side punch 23. However, other punches or another part of the first lower-side punch 22 may also follow. In addition to flat punches in particular cylindrical and annular punch can be used to form, for example, wheels or gears, which are formed with over the surface of different higher wall and in the radial direction of different material stratification or material composition.

After removal of the filling device 26, top-side punches 24, 25 are placed on the material p 1 from above. As a result, a first section s1 or a second section s2 forms as powder or material columns of the resulting compact 40 between the opposing end-side surfaces or lower surfaces of the lower or upper stamps.

On the basis of the next figure, the components of method step 1 are outlined in a time-later second method step 2. In the meantime, the upper-side punches 24, 25 were placed so that between the first lower-side punch 22 and the first upper-side punch 24, a first portion s1 of the resulting compact as the first powder or material column is formed and between the second lower-side punch 23 and the second upper-side punch 25, a second section s2 arises as a column of material. It is also shown that after placing the upper-side punches 24, 25, the die 20 has been moved to a significantly higher positions relative to the zero-pressing position h0. At this time or thereafter, the first lower-side and first upper-side punches 22, 24 having the material column therebetween were also formed as the first portion s1 raised. The lifting takes place at most so far that the material of the column of material, here the first section s1, always remains with its upper edge below an upper edge of the die 20. Shown is an intermediate time in which an intermediate height h3 of the surface 22o of the lower first punch 22 is raised to an original height of the die surface of the die 20, wherein the second upper-side punch 25 remains lowered down to this intermediate height h3. Thus, during this momentary situation, the surface 22o of the first lower punch 22 is at the same height as the lower surface 25u of the upper second punch 25 adjacent thereto. In other words, the materials in the first section s1 and in the second section s2 are between the two pairs of punches 22 - 24, 23 - 25 completely separated at this moment. After placing the upper plates or the attached on the upper side punch 24, 25 on the material p1 thus carried a shift of the powder or material columns s1, s2 relative to each other so far that contact between the powder columns is lost among themselves.

During this displacement and, in particular, also during a further displacement of the punches 22-25 and material columns s1, s2 relative to one another, precompression of the material also takes place in the first or in the second section s1, s2. A value of the pre-compaction may preferably be preset by a freely adjustable amount and ultimately adjusted by a different complaint of the mutually opposing punch pairs 22-24 or 23-25. This pre-compression is particularly advantageous in the subsequent filling of a second material p2, since this avoids that the materials p1, p2 mix vertically and horizontally with each other and there are clean separation lines between the powders.

The diagram of the third method step 3 shows the further method of the material columns and pre-compression up to a displacement of the upper edges of the sections s1, s2 of the material columns in a filling position for the second material p2. As an example, while the intermediate height h2 of the second lower side punch 23 was still maintained and the material in the second portion s2 was precompressed by lowering the second upper side punch 25, the first portion s1 as a column of material together with the first lower side punch 22 became one further intermediate height h4 of the first lower-side punch 22 is raised. This is purely by way of example clearly above the intermediate height h2 of the second lower-side punch 23.

Based on the fourth method step 4, a time even later time is sketched in which the top-side punches 24, 25 were completely lifted and the or another filling device 26 was guided over the die opening. By means of the filling device 26, the second material p2 is filled into the spaces above the first and the second section s1, s2 and then preferably painted surface plan with the surface of the die 21.

In a fifth method step 5 shown below, a placement of the upper-side punches 24, 25 and then a displacement of the material columns is performed. The one column of material now consists of the first section s1 of the first material p1 and a third section s3 of the second material between the first lower side and the first upper side stamps 22, 24. The other column of material consists of the second section s2 the first material p1 and an overlying fourth portion s4 of the second material p2 between the second lower-side and upper-side stamps 23, 25. In the purely exemplary procedure, not only the upper-side punches 24, 25 are lowered during this time course, but also the lower-side second punch 23 is raised to a further intermediate height h5. Due to the fact that the first material p1 was previously compressed or pre-compressed, no mixing of the two materials p1, p2 occurs.

Subsequently, with reference to a sixth method step 6, a further adjustment of the punches 22 - 25 is shown relative to one another, a pre-compression now also taking place of the second material p 2. In the illustrated position, the upper edges of the material columns have already reached a third filling position, which again lies below the upper edge of the optionally further raised die 20 in the meantime. Of course, even with this or one of the other filling positions, one of the lower-side punches can be adjusted to the same height as the upper edge of the die 20 so that there is no filling with the further new material via the stamper or over the material column located above it.

Using the exemplary seventh method step 7, it is shown that in the meantime the upper-side punches 24, 25 have been lifted off again and the or a further filling device 26 has again been moved over the die opening 21. In addition, third material p3 is filled. The third material may optionally also be the same material as in the first filling step.

Subsequently, in an eighth method step 8, the upper-side punches 24, 25 are replaced and compacted including the newly filled third material underneath. Resulting now powder columns from the first, third and a fifth section s1, s3, s5 or from the second, fourth and a sixth section s2, s4, s6 between the opposing pairs of punches 22 - 24 and 23 - 25.

In a subsequent ninth method step 9 it is shown that the two Prüfersäulen are moved relative to each other in a position in which later the individual components of the resulting compact 40 should be arranged not only in the horizontal, but also in lateral or radial direction to each other. There is thus a tester transport, in which the vertical powder or material columns are moved relative to each other.

This is followed by pressing or compaction, which is outlined in a tenth method step 10, wherein in particular in this step, a main pressing force from preferably the upper main press drive 28 on plates and the stamp 22 - 25 attached thereto takes place.

Finally, it is shown by means of an eleventh method step 11 that the resulting compact 30 is excluded from the die 20 at the top by lifting the lower-side rams 22, 23 and the upper-side rams 24, 25 relative to the upper die edge of the die 20. As an alternative to the exemplary ejection, it is also possible to remove it by moving the die relative to the compact 30, as is known per se.

The described method steps represent purely by way of example selected times of a pressing cycle for a compact 30. Optionally, individual ones may also be used these process steps are omitted or added further process steps.

LIST OF REFERENCE NUMBERS

1

Filling with first material

2

Placing top stamps and method of the powder or material columns relative to each other

3

Another method of material columns and pre-compaction

4

Filling with second material

5

Placing the top stamps and method of the material columns

6

supercharging

7

Fill with third material

8th

Placing the top stamps and precompressing

9

Powder or material transport and method of material columns

10

Pressing or final compression to the compact

20

die

21

die opening

22, 23

bottom punch, in particular punch

22o

Surface of the lower first punch

24, 25

top-side stamp, in particular punch

25u

Lower surface of the upper second punch

26

filling

27

control device

28

Upper main press drive

30

compacts

h0

Zero-pressing position

h1

Intermediate height of the first underside stamp

h2

intermediate height of the second bottom punch

h3

Intermediate height of the first underside stamp

h4

Intermediate height of the first underside stamp

h5

intermediate height of the second bottom punch

p1

first metallic and / or ceramic powder and / or granular material

p2

second material

p3

third material

s1

first section of the compact as powder or material column

s2

second section as a column of material

s3

third section as a column of material

s4

fourth section as a column of material

s5

fifth section as a column of material

s6

sixth section as a column of material

Claims (12)

1. A method of compressing a compact (30) of at least two different metallic and/or ceramic powdery and/or granular materials (p1, p2, p3), wherein

   - a first such material (p1; p2) is filled into a die opening (21) of a die (20) (1; 4),

   - at least two top punches (22, 24) are at least temporarily placed on the material (p1; p2) in the die opening (21) (2; 5),

   - bottom and top punches (22, 23, 24, 25) together with interposed material columns are adjusted to different heights along a pressing direction (2 - 3; 5 - 6),

   - after lifting off the top punches (24, 25) the second material (p2; p3) is filled into the die opening (21),

   - the material (p1; p2) is finally end-compacted by the at least two top punches (24, 25) (9 - 10),

   - wherein the material columns are pre-compacted between the bottom and top punches (22, 23, 24, 25) prior to a first adjustment relative to each other (2 - 3).
2. The method according to claim 1, wherein the adjustment of the bottom and top punches (22, 23, 24, 25) is carried out together with the interposed material columns until a contact is lost between adjacent material columns (2; 5).
3. The method according to claim 2, wherein the adjustment of the bottom and top punches (22, 23, 24, 25) is carried out together with the interposed material columns until the adjacent material columns are no longer in contact with each other (2).
4. The method according to claim 2 or 3, wherein after the loss of contact, the bottom and top punches (22, 23, 24, 25) are adjusted together with the interposed material columns into a position in which the second material (p2; p3) is filled in (4; 7).
5. The method according to any of the preceding claims, wherein the adjustment to different heights is carried out independently of temporarily reaching a subsequent second filling position for the second material (p2; p3).
6. The method according to any of the preceding claims, wherein the adjustment occurs in an intermediary step beyond the filling position or in a direction opposed to a direction of the subsequent filling position.
7. The method according to any of the preceding claims, wherein an/the adjustment for the loss of lateral contact of the material columns is carried out independently of temporarily reaching a subsequent second filling position for the second material (p2; p3).
8. The method according to any of the preceding claims, wherein the material columns are pre-compacted between the bottom and top punches (22, 23, 24, 25) during or after the first adjustment of the material columns relative to each other (3).
9. The method according to any of the preceding claims, wherein at least one of the bottom and top punches (22, 24) has an annular configuration or is formed with an internal passage hole for passing through at least one further bottom and top punch (23, 25).
10. An apparatus, comprising

    - a die (20) with a die opening (21),

    - at least two punches (22, 23) reaching into the die opening (21) from the bottom,

    - at least two punches (24, 25) insertable into the die opening (21) from the top,

    - a filling device (26) for filling the die opening (21) with at least two different metallic and/or ceramic powdery and/or granular materials (p1, p2) and

    - a control device (27), the control device being formed and/or programmed to carry out a method according to any of the preceding claims.
11. The apparatus according to claim 10, configured as a ceramic and/or metal powder press having compressing punches as the punches (22, 23, 24, 25).
12. A data carrier having a program stored thereon, which is programmed for carrying out the method according to any of claims 1 to 9 in an apparatus according to claim 10 or 11.

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