Method and powder pressing device for powder pressing at least two pressed parts - Patents.com

Abstract

The present invention relates to a method for powder pressing at least two pressed parts, in particular ceramic and / or metal powder pressed parts, in which a first powder (17) for pressing the first pressed part is filled to a first filling height in a first cavity (13) of a die (12) and a second powder (18) for pressing the second pressed part is filled to a second filling height in a second cavity (14) of the die (12), and the first and second filling heights are adjusted independently. Preferably, the first powder (17) is filled via a first filling shoe (10) and the second powder (18) is filled via a second filling shoe (11), in which the two filling shoes (10, 11) are moved asynchronously at least during a predetermined time. A powder pressing apparatus suitable for carrying out the above-described method is also claimed.

Description

[Technical Field]

[0001] The present invention relates to a method for powder pressing at least two pressed parts, in particular ceramic powder pressed parts and / or metal powder pressed parts, and to a corresponding pressing device. [Background technology]

[0002] To be able to press several pressed parts from one (powdered) starting material (i.e., in one pressing process), several cavities must be prepared. For this, the starting material (powder) is fed into both cavities together and filled accordingly before the actual pressing. The quality of the pressed parts produced in this way is considered to be something that could be improved. Summary of the Invention [Problem to be solved by the invention]

[0003] The object of the present invention is to propose a method and a corresponding pressing device for powder pressing at least two pressed parts, whereby it is desirable to improve the quality (in particular with regard to the dimensions and / or weight of the pressed parts). [Means for solving the problem]

[0004] In particular, this problem is solved by a method for powder pressing at least two pressed parts, in particular ceramic and / or metal powder pressed parts, in which a first powder (in particular comprising a metal and / or ceramic) for pressing a first pressed part is filled to a first filling height in a first cavity of a die, and a second powder (in particular comprising a metal and / or ceramic material) for pressing a second pressed part is filled to a second filling height in a second cavity of the die, and the first and second filling heights are adjusted independently of each other. After filling, a pressing step preferably follows, in which the at least two pressed parts are pressed preferably simultaneously or at least overlapping in time.

[0005] The core idea of the present invention is to adjust the first and second fill heights independently of each other. In this regard, it has been recognized that the present invention allows the filling of multiple (e.g., two) cavities to be performed differently (e.g., even through careful adjustment of the filler and / or the fill tube). By changing or being able to change the fill heights for both (or multiple) cavities together (as well as individually or independently of each other), significant quality improvements can be achieved.

[0006] The die is preferably made from one piece, in particular integrally (possibly monolithically), but may also consist of several pieces. The press (pressing device) used in this method can have at least one or exactly one, or at least two or exactly two upper punches per cavity, and optionally at least one or exactly one, or at least two or exactly two lower punches. During pressing, the lower punch(s) is / are preferably supported rigidly, i.e., not floatingly or hydraulically supported.

[0007] The fill height may be understood in particular as the distance between the corresponding lowest fill point and the corresponding highest fill point (after the filling step is completed and before the next pressing step) and / or may be expressed as the vertical distance between the corresponding fill heights relative to a common reference point (after the filling step is completed and before the next pressing step), such as the upper ends of the cavities and / or, if appropriate, the upper surface of a common die and / or the (fixed) base of the pressing device. Individual adjustment of the (respective) fill heights is understood in particular to mean that the fill heights (e.g., first fill heights) can be adjusted or changed (especially relative to the preceding fill step) independently of the other fill heights (e.g., second fill heights). For example, the (e.g., first) fill height is changed or changeable (relative to the preceding fill height in the preceding filling step), and the second fill height is not changed (relative to the preceding fill height in the preceding filling step).

[0008] In an embodiment, the size (or volume) of at least one (or both or all) cavities can be changed, in particular expanded, between the start of filling the cavity and the end of filling the cavity. This allows for a particularly simple adjustment of the filling height, for example, when the cavity is filled (at a given filling step) to its upper edge. However, it is also possible for the (each) cavity to be adapted accordingly already before the start of the filling process and not to be further changed thereafter (in terms of cavity volume, until the end of the filling process). However, in general, the step of adjusting the filling height involves at least one volume change of at least one cavity, in particular a volume expansion of at least one cavity.

[0009] Preferably, the first powder is filled via a first filling shoe, and the second powder via a second filling shoe. These filling shoes are preferably spaced apart or at least structurally defined or have powder material receiving portions defined by each other. Furthermore, preferably, the first filling shoe and the second filling shoe are movable asynchronously or are moved asynchronously, at least at certain times. In a specific embodiment, the (particularly first) filling shoe can be moved away from the (first) cavity while the other (second) filling shoe remains above the other (second) cavity. This allows for particularly simple individual adjustment. In particular, this allows both filling shoes not necessarily to be positioned above (or spaced apart from) their respective cavities at the same time, which makes it possible, for example, to fill only one cavity but not the other. This allows for a simple improvement in the quality of the component.

[0010] At least two filling steps can be performed when filling at least one, preferably the second cavity. The at least two filling steps should be performed, particularly when and / or during filling, while the filling of the other cavity (particularly the first cavity) is interrupted. The first filling step of filling the second cavity with the second powder is preferably performed before and / or during the filling step of filling the first cavity with the first powder. The second filling step of filling the second cavity with the second powder is preferably performed while the filling step of filling the first cavity with the first powder is not being performed, particularly after the first filling shoe has been moved away from the first cavity. In this context, when two (or more) filling steps are mentioned, this should be understood as two different time segments of one common overall filling step, where an overall filling step is understood to be a step in which the materials to be pressed are completely filled into the corresponding cavities so that they can then be pressed. In other words, two filling steps does not particularly mean repeatedly filling a cavity in order to press several components, but rather multi-stage (including multiple steps) filling of the same cavity. Overall, this allows for individual adjustment in a simple manner.

[0011] Preferably, the first cavity is completely filled before the second cavity is completely filled, which also allows for an individual adjustment of the filling level in a particularly simple manner.

[0012] According to an embodiment, at least one first lower punch assigned to the first cavity and / or at least one second lower punch assigned to the second cavity are supported in a non-floating manner (or via a fixed stop). That is, in particular, the first lower punch and / or the second lower punch do not move (except for the compression movement) and remain stationary during pressing. In particular, the first lower punch and / or the second lower punch should not be hydraulically supported (during pressing).

[0013] Preferably, the first pressed part and / or the second pressed part are measured, preferably weighed, in particular separately after pressing. Based on this measurement (especially weighing), a new first and / or second fill height is preferably determined, in particular calculated. Furthermore, the cavity assigned the lower fill height can then be completely filled before the other cavity is completely filled. If the fill height can only be changed for both cavities together, a (preferably automatic) adjustment of the fill height is made, in particular based on the average weight of both pressed parts. The individual adjustment of the fill height and the individual measurement of the pressed parts results in a significant overall improvement in quality.

[0014] Generally, the adjustment of the filling height can be carried out automatically (especially by an electronic control device), taking into account the corresponding measurement of the pressed part. The corresponding filling height can be changed or adapted independently of this measurement. This generally results in a simple improvement in quality.

[0015] The first cavity and / or the second cavity are preferably filled up to their respective upper edges after (complete) filling, respectively, and / or immediately before the interruption of (complete) filling, respectively, and / or between the first and second filling steps, and / or immediately before the pressing step. The first cavity and / or the second cavity may not be filled up to their respective upper edges after (complete) filling, respectively, and / or immediately before the interruption of (complete) filling, respectively, and / or between two filling steps, and / or immediately before the pressing step. In particular, the second cavity may be filled up to its upper edge after (complete) filling, while the first cavity is not filled (or vice versa).

[0016] After (complete) filling of each of the first and second cavities and / or immediately before the pressing step, the upper end of the first filling in the first cavity and the upper end of the second filling in the second cavity may be at the same height or at different heights.

[0017] Furthermore, after (complete) filling of each of the first and second cavities and / or immediately before the pressing step, the lower end of the first filling in the first cavity and the lower end of the second filling in the second cavity may be at the same height or at different heights.

[0018] With at least two cavities, it is possible to produce two pressed parts that are the same or at least similar (in terms of weight and / or geometry), or to produce two different pressed parts.

[0019] More than two press parts can be pressed in one pressing operation, for example at least three or at least five press parts.

[0020] At least one first lower punch assigned to a first cavity and at least one second lower punch assigned to a second cavity, in particular all lower punches assigned to the first cavity (on the one hand) and the second cavity (on the other hand), can move independently of one another before and / or during filling of the corresponding cavity, or can be independently movable and / or connected to different plates (adapter plates). This allows the cavity height or filling height to be individually adjusted via the individual positioning of each lower punch. Such adjustment is relatively easy (e.g., via a corresponding configuration of the control device), but does not pose any problems if an eccentric force is applied to the corresponding plate (adapter plate).

[0021] Alternatively, at least one first lower punch assigned to a first cavity and at least one second lower punch assigned to a second cavity can move together before and / or during filling of the corresponding cavity, or can be movable together and / or can be connected to the same plate (adapter plate). This type of connection precludes the possibility of individually adjusting the filling height by adjusting the corresponding lower punch. However, adjustment of the filling height can be particularly preferably performed in this case by means of individual, individually movable filling shoes.

[0022] The starting material (powder) can be provided to the first and second cavities, and possibly further cavities, in common (e.g. via a common filling device, in particular via a common filling shoe, which in the case of independently movable lower punches may optionally have only one chamber for this material) or separately (e.g. via separate, preferably independently movable filling devices, in particular filling shoes) and can be filled accordingly.

[0023] The above-mentioned object is further achieved by a powder pressing apparatus for powder pressing at least two pressed parts, in particular ceramic powder pressed parts and / or metal powder pressed parts, particularly for carrying out the above-mentioned method, the powder pressing apparatus comprising at least one first cavity of a die for pressing the first pressed part from a first powder and a second cavity of a die for pressing the second pressed part from a second powder, at least one filling device, in particular at least one filling shoe, preferably at least one first filling shoe and one second filling shoe, for filling the first or second powder into the first or second cavity, and at least one control device configured to control the pressing apparatus so that the first powder is filled to a first filling height and the second powder is filled to a second filling height, wherein the first and second filling heights are independently adjustable. Regarding the advantages, reference is made to the description of the above-mentioned method. The powder pressing apparatus (powder press) may have at least one or exactly one, or at least two or exactly two upper punches per cavity, and optionally at least one or exactly one, or at least two or exactly two lower punches.

[0024] The first powder may be the same in composition as the second powder or may be different in composition from the second powder. The first powder and the second powder may be from the same source. Alternatively, the first powder and the second powder may be provided from different sources.

[0025] At least one, several, or all of the punches (lower punch and / or upper punch) can be driven by an electric motor and / or hydraulically. Preferably, the first and second filling devices, particularly the first and second filling shoes, are movable non-simultaneously (or independently) at least at a predetermined time (via the corresponding first and / or second driving devices). More preferably, the first filling device (first filling shoe) can move away from the first cavity when the second filling device (second filling shoe) is positioned above the second cavity.

[0026] At least one first lower punch assigned to the first cavity and / or at least one second lower punch assigned to the second cavity may be supported in a non-floating manner (or via a fixed stopper) (at least during pressing).

[0027] At least one measuring device, in particular a weighing device, is preferably provided for measuring, in particular weighing, the first pressed part and / or the second pressed part, in particular individually, after pressing. Preferably, a determining unit, in particular a calculating unit, can further be provided for determining, preferably calculating, a new first and / or second filling height based on the measurement, in particular the weighing, so that the cavity assigned the lower filling height can then preferably be completely filled before the other cavity is completely filled.

[0028] At least one first lower punch assigned to the first cavity and at least one second lower punch assigned to the second cavity, in particular all lower punches assigned to the first cavity (on the one hand) and the second cavity (on the other hand), may be movable independently of one another before and / or during filling of the corresponding cavities and / or may be connected to different plates (adapter plates).

[0029] At least one first lower punch assigned to a first cavity and at least one second lower punch assigned to a second cavity may be movable together (only) before and / or during filling of the corresponding cavity and / or may be connected to the same plate (adapter plate).

[0030] The object is further achieved by the use of a pressing device as described above and below for powder pressing at least two pressed parts, in particular ceramic powder pressed parts and / or metal powder pressed parts.

[0031] If the height and / or volume of the corresponding cavity is changed before or during filling, this is done by moving the die relative to at least one associated lower punch, i.e., for example, by moving the die and keeping the associated lower punch in place, or vice versa, or by moving both the die and the lower punch.

[0032] In a specific method configuration, the press has two (separate) filling shoes arranged adjacent to each other, which are preferably driven by two independent filling shafts.

[0033] The first filling position is adapted to a cavity with a (slightly) lower filling height (e.g., also referred to as the first cavity with an assigned first filling shoe). Both filling shoes can then be positioned (moved) above the cavity (e.g., synchronously). The first filling shoe performs a (basically normal) filling movement and then returns again (e.g., to the starting position). The second filling shoe also first performs a (basically normal) filling movement, but then preferably remains above the second cavity before performing its final retraction movement.

[0034] As soon as the first filling shoe is no longer positioned above the first cavity, the die and / or the corresponding lower punch (or a plate assigned to the lower punch) moves to the desired filling position for the second cavity.

[0035] After the second filling shoe has finished filling, the normal press cycle can be carried out.

[0036] Both parts can be weighed separately after pressing. Based on the weight of each part, the new fill height is calculated and, if necessary, the fill height can be adjusted or adapted (automatically).

[0037] The cavity can then be refilled initially with a (slightly) lower fill height.

[0038] In an alternative embodiment of the method, each (lower) punch may be connected to its own plate (adapter plate), in which case the filling and pressing positions of (all) the punches can preferably be adjusted individually.

[0039] The press control is configured to accommodate (individual) fill height adjustment of both cavities (or cavities).

[0040] Further embodiments are set forth in the dependent claims.

[0041] The invention will be explained below on the basis of an embodiment which is explained in detail with reference to the drawings. [Brief explanation of the drawings]

[0042] [Figure 1] 1 is a schematic view of a first embodiment of a press device as seen from above. [Figure 2] FIG. 2 shows the embodiment of FIG. 1 in a schematic cross-sectional view. [Figure 3] 2A to 2C show the embodiment of FIG. 1 in different states; [Figure 4]FIG. 4 is a schematic cross-sectional view illustrating the state of FIG. 3. [Figure 5] 2 is a schematic view from above of the embodiment of FIG. 1 in another state. [Figure 6] FIG. 6 is a schematic cross-sectional view illustrating the state of FIG. 5. [Figure 7] 2 is a schematic view from above of the embodiment of FIG. 1 in another state. [Figure 8] FIG. 8 is a schematic cross-sectional view illustrating the state of FIG. 7. [Figure 9] FIG. 10 is a schematic view of another embodiment of a press device as seen from above. [Figure 10] FIG. 10 shows the embodiment of FIG. 9 in a schematic cross-sectional view. [Figure 11] 10 is a schematic view from above of the embodiment of FIG. 9 in another state. [Figure 12] FIG. 12 is a schematic cross-sectional view illustrating the state of FIG. [Figure 13] 10 is a schematic view from above of the embodiment of FIG. 9 in another state. [Figure 14] FIG. 14 is a schematic cross-sectional view illustrating the state of FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0043] In the following description, the same reference numerals are used for the same parts and parts that perform the same functions.

[0044] 1 shows a (highly) schematic top view of a press apparatus according to the present invention. The press apparatus includes a first filling shoe 10, a second filling shoe 11, a die 12, and a first and second cavity 13, 14. A first press part (not shown) can be pressed in the first cavity 13, and a second press part (also not shown) can be pressed in the second cavity 14. In the state of the press apparatus shown in FIG. 1, the filling shoes 10, 11 are not positioned above the cavities 13, 14. In this state, the starting material (powder) is not filled into the cavities 13, 14.

[0045] According to Figure 2, the cavities 13, 14 are defined by a first lower punch 15 and a second lower punch 16. There may be multiple lower punches, for example two, per cavity.

[0046] The filling shoes 10, 11 are arranged adjacent to each other or at the same height and, according to this configuration, are driven by two independent filling shafts.

[0047] In Figure 3, the filling shoes 10, 11 of Figure 1 are now positioned above the cavities 13, 14. This allows a first powder 17 (see Figure 4) and a second powder 18 to be filled into the cavities 13, 14. In Figure 4, the cavities are filled with the respective powders 17, 18 up to their upper edges (in the extension shown in Figure 4). That is, the upper end of the corresponding fill in the first cavity 13 is at the same level as the upper end of the fill in the second cavity 14. In this case, too (although not necessarily), the lower end of the fill in the first cavity 13 is at the same level as the lower end of the fill in the second cavity 14.

[0048] 4 thus shows a first filling position of the lower punches 15, 16 (which are preferably movable together in this case). This first filling position is preferably aligned with the cavity having the lower (necessary or required) filling height. This configuration allows both filling shoes to move synchronously above the cavities 13, 14.

[0049] The first filling shoe 10 performs the filling process and then returns to its starting position again (see FIG. 5), with the second filling shoe 11 remaining above the associated cavity 14 (after the second filling shoe has also performed the filling process).

[0050] Once the first filling shoe 10 is no longer positioned above the associated cavity 13, the die 12 and / or at least one plate (not shown) associated with the lower punch 15, 16 is moved, resulting in a relative movement between the die and the punch 15, 16 (see FIG. 8 ). This allows additional material of the second powder 18 to be filled into the second cavity 14. As a result, the fill height in the second cavity 14 is greater overall than the fill height in the first cavity 13.

[0051] After the second filling shoe 11 has finished (complete) filling, the pressing cycle is carried out in a known manner.

[0052] After pressing, the pressed parts from both cavities are weighed (individually). Based on the weight of each part, a new fill height is calculated and, if necessary, the fill height is adjusted (automatically).

[0053] Then, first, the cavity having the comparatively lower (necessary or required) fill height is refilled.

[0054] An alternative embodiment is shown in Figures 9 to 14. In this case, the first lower punch 15 and the second lower punch 16 are movable via the first lower punch plate 20 and the second lower punch plate 21. In the starting position shown in Figures 9 and 10, the filling shoes 10, 11 are not above the upper ends 22, 23 of the associated cavities 13, 14 and lower punches 15, 16, but are at the same height. In this state, the cavities 13, 14 are at the same height.

[0055] 11 and 12, the second lower punch plate 21 now moves downwards, while the first lower punch plate 20 remains in the same place (it can also move if necessary). The filling shoes 10, 11 (see FIG. 11) are still in their starting position (but may already have moved at least partially).

[0056] The filling shoes 10, 11 (see FIG. 13) are now positioned (jointly or individually moved) above the cavities 13, 14. After the cavity 14 in FIG. 12 has been enlarged, the filling height shown in FIG. 14 of the second powder 18 is now correspondingly enlarged. In this embodiment, the filling and pressing positions of several, possibly all, punches can be adjusted individually. Corresponding programming can be provided for the individual filling height adjustment.

[0057] It is hereby pointed out that all the above-mentioned parts, both individually and in each combination, and in particular the details shown, are claimed as essential to the invention. Modifications of the invention are possible for those skilled in the art. [Explanation of symbols]

[0058] 10 First filling shoe 11 Second filling shoe 12 Die 13 First cavity 14 Second cavity 15 First bottom punch 16 Second bottom punch 17 First Powder 18 Second Powder 20 First lower punch plate 21 Second lower punch plate 22 Upper end of first lower punch 15 23 Upper end of second lower punch 16

Claims

1. A method for powder pressing at least two pressed parts, comprising filling a first powder (17) for pressing a first pressed part into a first cavity (13) of a die (12) to a first fill height, and filling a second powder (18) for pressing a second pressed part into a second cavity (14) of said die (12) to a second fill height, and adjusting the first and second fill heights independently; The first powder (17) is filled via a first filling device, a first filling shoe (10), and the second powder (18) is filled via a second filling device, a second filling shoe (11), and the first filling shoe (10) and the second filling shoe (11) are moved at least partially asynchronously, and the first filling shoe (10) is already moved away from the first cavity (13) while the second filling shoe (11) still remains above the second cavity (14); measuring the first pressed part and the second pressed part after pressing, determining a new first or second fill height based on the measurements, and completely filling the cavity assigned the lower fill height before the other cavity is completely filled. method.

2. 2. The method according to claim 1, wherein at least two filling steps are performed in filling the second cavity (14), and a first filling step of filling the second cavity (14) with the second powder (18) is performed before or during a filling step of filling the first cavity (13) with the first powder (17), and a second filling step of filling the second cavity (14) with the second powder (18) is performed while the filling step of filling the first cavity (13) with the first powder (17) is not being performed.

3. 3. The method according to claim 1, wherein the first cavity (13) is completely filled before the second cavity (14) is completely filled.

4. 4. The method according to claim 1, wherein at least one first lower punch (15) assigned to the first cavity (13) or at least one second lower punch (16) assigned to the second cavity (14) is supported in a non-floating manner.

5. the first cavity (13) or the second cavity (14) is filled to the respective upper edge or not filled to the respective upper edge after each filling or immediately before each filling interruption or immediately before the pressing step; or After each filling of the first cavity (13) and the second cavity (14) or immediately before the pressing step, the upper end of the first filling in the first cavity (13) and the upper end of the second filling in the second cavity (14) are at the same height or at different heights; or The lower end of the first filling in the first cavity (13) and the lower end of the second filling in the second cavity (14) are at the same height or at different heights.

5. The method according to any one of claims 1 to 4.

6. 6. The method according to claim 1, wherein at least one first lower punch (15) assigned to the first cavity (13) and at least one second lower punch (16) assigned to the second cavity (14) are moved independently of each other or are connected to different plates before or during filling of the corresponding cavity (13, 14).

7. 6. The method according to claim 1, wherein the at least one first lower punch (15) assigned to the first cavity (13) and the at least one second lower punch (16) assigned to the second cavity (14) move together or can only move together or are connected to the same plate before or during filling of the corresponding cavity (13, 14).

8. A pressing device for powder pressing at least two pressed parts for carrying out the method according to any one of claims 1 to 7, comprising: at least one first cavity (13) of a die (12) for pressing a first pressed part from a first powder (17) and a second cavity (14) of said die (12) for pressing a second pressed part from a second powder (18); at least one first filling shoe (10) and a second filling shoe (11) for filling the first powder (17) or the second powder (18) into the first cavity or the second cavity; at least one control device configured to control the pressing device such that the first powder (17) is filled at a first fill height and the second powder (18) is filled at a second fill height, the first fill height and the second fill height being adjustable independently of each other; a press device,

9. 9. The press device according to claim 8, wherein the first filling shoe (10) and the second filling shoe (11) are movable non-simultaneously at least at a predetermined time, and when the second filling shoe (11) is positioned above the second cavity (14), the first filling shoe (10) can move away from the first cavity (13).

10. 10. The press device according to claim 8 or 9, wherein at least one first lower punch (15) assigned to the first cavity (13) or at least one second lower punch (16) assigned to the second cavity (14) is supported in a non-floating manner.

11. 11. The pressing device according to claim 8, wherein at least one measuring device is provided for measuring the first pressed part and the second pressed part after pressing, and a determination unit is further provided for determining a new first or second filling height based on the measurements, so that the cavity assigned a lower filling height can be completely filled before the other cavity is completely filled.

12. 12. The pressing device according to claim 8, wherein the at least one first lower punch (15) assigned to the first cavity (13) and the at least one second lower punch (16) assigned to the second cavity (14) are movable independently of each other or are connected to different plates before or during filling of the corresponding cavity (13, 14).

13. 12. A pressing device according to claim 8, wherein the at least one first lower punch (15) assigned to the first cavity (13) and the at least one second lower punch (16) assigned to the second cavity (14) can only move together or are connected to the same plate before or during filling of the corresponding cavity (13, 14).

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