Method for Determining a Parameter of a Material and Pressing Tool for the Production of a Green Compact

Abstract

At least one parameter of a material is determined with a pressing tool usable for producing a green compact and a pressing tool for producing at least one green compact. The pressing tool has at least one planar surface which is formed at least in part by a die which, starting from the surface, extends along an axial direction and, on the surface, has a cavity which extends from the surface along the axial direction and has an inner circumferential surface; wherein the cavity forms a receptacle for a powdery material which can be pressed in the cavity by at least one punch plunging into the cavity along the axial direction to form the green compact.

Claims

1. A method for determining at least one parameter of a material with a pressing tool which can be used for producing a green compact, the pressing tool having at least one working plane with at least one planar surface, a die which at least partially forms the surface, a punch movable relative to the surface along an axial direction, a filling shoe for providing a powdery material, and a measuring device for determining the parameter of the material used for producing the green part; wherein the die extends from the surface along the axial direction and has at the surface a cavity extending from the surface along the axial direction and having an inner circumferential surface; the cavity forming a receptacle for the powdered material, which can be pressed in the cavity into the green compact by at least the punch plunging into the cavity along the axial direction; the filling shoe being movable along the surface; wherein the pressing tool has an opening at the surface and along a radial direction next to the cavity, at which opening the measuring device is arranged, wherein the measuring device has a constant volume directly adjoining the surface and the opening with a closable outlet opening; wherein the method comprises at least the following steps: a) filling the filling shoe with the material from a storage container; b) moving the filling shoe over the surface and across the opening; c) at least partially filling the volume with the material from the filling shoe via the opening; d) carrying out the determination of the at least one parameter by the measuring device and removing the material from the volume via the outlet opening.

2. The method according to claim 1, wherein the filling shoe is filled in step a) in a starting position, is moved in step b) from the starting position to the opening, and is moved after step c) in a step i) back to the starting position.

3. The method according to claim 2, wherein the filling shoe is moved towards the cavity before step b), immediately after step b) or immediately after step c) in a step ii) and the receptacle is filled from the filling shoe; wherein after step ii) in a step iii) the punch plunges into the cavity for pressing the material and for producing the green compact.

4. The method according to claim 3, wherein during a production of a plurality of green compacts, step ii) is performed with a greater frequency than step c).

5. The method according to claim 1, wherein the volume is completely filled in step c).

6. The method according to claim 1, wherein the pressing tool comprises a control device by which a sequence and frequency of at least steps a), b), c) and d) is determined as a function of at least the following boundary conditions: a value of the at least one determined parameter; a specification for the determination; a filling level of the material in the storage container; a time interval during which the material is stored in the storage container or in the filling shoe.

7. A pressing tool for producing at least one green compact, the pressing tool having at least one planar surface which is formed at least partially by a die which, starting from the surface, extends along an axial direction and, on the surface, has a cavity which extends from the surface along the axial direction and has an inner circumferential surface; wherein the cavity forms a receptacle for a powdery material which can be pressed into the green compact in the cavity by at least one punch plunging into the cavity along the axial direction; wherein the pressing tool has an opening on the surface and along a radial direction next to the cavity, on which opening a measuring device is arranged for determining a parameter of the material used for producing the green compact.

8. The pressing tool according to claim 7, wherein the parameter is at least a flow rate or a density of the material.

9. The press tool according to claim 8, wherein the measuring device has a constant volume directly adjoining the surface and the opening with a closable outlet opening, so that the material can be filled into the volume via the opening and can be discharged from the volume via the outlet opening; wherein the measuring device has at least a first sensor for detecting the flow rate, which detects the discharge of the material via the outlet opening, or has a second sensor, which detects the weight of the material located in the volume, so that the density can be determined therefrom.

10. The pressing tool according to claim 9, wherein the opening is closable by a cover.

11. The pressing tool according to claim 7, additionally comprising a filling shoe for providing the powdery material, wherein the filling shoe is movable along the surface; wherein the filling shoe is movable over the cavity for filling the cavity and over the opening for filling the measuring device.

12. The press tool according to claim 11, wherein the filling shoe has a starting position in which the filling shoe is fillable from a storage container for the material, wherein the opening is arranged between the starting position and the cavity or the starting position is arranged between the cavity and the opening.

13. The pressing tool according to claim 11, additionally comprising the punch movable relative to the surface along the axial direction, a filling shoe for providing the powdered material, and a control device which is set up to carry out a method including the steps of filling the filling shoe with the material from a storage container; moving the filling shoe over the surface and across the opening; at least partially filling a volume with the material from the filling shoe via the opening; and carrying out the determination of the at least one parameter by the measuring device and removing the material from the volume via the outlet opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The invention and the technical environment are explained in more detail below with reference to the figures. It should be noted that the invention is not to be limited by the embodiments shown. In particular, unless explicitly shown otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and findings from the present description and/or figures. In particular, it should be noted that the figures and especially the proportions shown are only schematic. Identical reference signs designate identical objects, so that explanations from other figures can be used as a supplement if necessary. The figures show:

[0066] FIG. 1: a side view of a press tool in section; and

[0067] FIG. 2: a section of the working plane in a side view in cross section.

DETAILED DESCRIPTION

[0068] FIG. 1 shows a press tool 3 in a side view in section. FIG. 2 shows a section of the working plane 4 or the pressing tool 3 in a side view in section. FIGS. 1 and 2 are described together below.

[0069] The pressing tool 3 comprises the punches 8 movable relative to the surface 5 along the axial direction 7, a filling shoe 9 for providing the powdery material 1, and a control device 20 which is set up to carry out the process described.

[0070] The pressing tool 3 has a flat/planar surface 5, which is formed in part by a die 6, which extends from the surface 5 along an axial direction 7 and has on the surface 5 a cavity 11 extending from the surface along the axial direction 7 and having an inner circumferential surface 12. The cavity 11 forms a receptacle 13 for a powdered material 1, which can be pressed into the green compact 2 in the cavity 11 by two punches 8 plunging into the cavity 11 along the axial direction 7. The pressing tool 3 has an opening 15 on the surface 5 and along a radial direction 14 next to the cavity 11, on which a measuring device 10 is arranged for determining a parameter of the material 1 used to produce the green compact 2.

[0071] The measuring device 10 has a constant volume 16 directly adjoining the surface 5 and the opening 15, with a closable outlet opening 17, so that the material 1 can be filled into the volume 16 via the opening 15 and discharged from the volume 16 via the outlet opening 17. The measuring device 10 has a first sensor 22 and a second sensor 23. The first sensor 22 (e.g., light source, light beam, sensor) is used to detect the flow rate, which detects the discharge of the material 1 via the outlet opening 17. The second sensor 23 is used to detect the weight of the material 1 in the volume 16, so that the density can be determined therefrom.

[0072] The opening 15 may be closable by a cover 24 (see FIG. 2).

[0073] The pressing tool 3 comprises a filling shoe 9 for providing the powdered material 1, the filling shoe 9 being movable along the surface 5. The filling shoe 9 is arranged to be movable on the working plane 4 for filling the cavity 11 via the cavity 11 and for filling the measuring device 10 via the opening 15.

[0074] The filling shoe 9 has a starting position 19 (see FIG. 1) in which the filling shoe 9 can be filled from a storage container 18 for the material 1, the opening 15 being arranged between the starting position 19 and the cavity 11 (see FIG. 1, left position of the measuring device 10) or the starting position 19 being arranged between the cavity 11 and the opening 15 (see FIG. 1, right position of the measuring device 10).

[0075] According to step a) of the method, filling of the filling shoe 9 with the material 1 from the storage container 18 takes place. According to step b), movement of the filling shoe 9 over the surface 5 and over the opening 15 takes place. According to step c), at least partial filling of the volume 16 with the material 1 from the filling shoe 9 via the opening 15 takes place. According to step d), the determination of the at least one parameter is carried out by the measuring device 10 and the material 1 is removed from the volume 16 via the outlet opening 17. The outflow of the material 1 from the volume 16 is carried out via an outlet opening 17 which can be closed by a slide 25. Thus, the volume 16 of the material 1 to be measured is structurally predetermined by the measuring device 10.

[0076] The filling shoe 9 is filled in a starting position 19 in step a), moved from the starting position 19 to the opening 15 in step b) and moved back to the starting position 19 after step c) in a step i).

[0077] The filling shoe 9 can be moved towards the cavity 11 before step b), immediately after step b) or immediately after step c) in a step ii) and the receptacle 13 can be filled from the filling shoe 9. The punches 8 plunge into the cavity 11 for pressing the material 1 and producing the green compact 2 after step ii) in a step iii).

[0078] The second sensor 23 of the measuring device 10 comprises a bending beam with strain gauges. This allows the mass of the material 1 arranged in the volume 16 to be measured. From the quotient of (measured) mass and (known) volume 16, the filling density can be calculated.

[0079] By opening the outlet opening 17, the volume 16 is emptied. The time required for the material 1 to flow out of the volume 16 can be determined with the first sensor 22, a light barrier that triggers a stopwatch. To determine the flow rate, the measured time and the measured mass are converted to a normalized mass sample of 50 grams using a rule of three. The measuring device 10 can be operated via the control device.

LIST OF REFERENCE SIGNS

[0080] 1 Material

[0081] 2 Green compact

[0082] 3 Pressing tool

[0083] 4 Working plane

[0084] 5 Surface

[0085] 6 die

[0086] 7 axial direction

[0087] 8 punch

[0088] 9 filling shoe

[0089] 10 measuring device

[0090] 11 cavity

[0091] 12 inner circumferential surface

[0092] 13 receptacle

[0093] 14 radial direction

[0094] 15 opening

[0095] 16 volume

[0096] 17 outlet opening

[0097] 18 storage container

[0098] 19 starting position

[0099] 20 Control device

[0100] 21 filling level

[0101] 22 first sensor

[0102] 23 second sensor

[0103] 24 lid

[0104] 25 slider