Method for evaluating the wear condition of parts of a rotary press machine and rotary press machine

Abstract

To provide a method for evaluating an abrasion state of components of a rotary press machine.SOLUTION: A rotary press machine includes a rotatable rotor. The rotor comprises: an upper punch guide for upper pressing punch; a lower punch guide for lower pressing punch; and a die plate arranged between the punch guides. The rotary press machine further includes a filling device, and a cavity of the die plate is filled with powder materials to be pressed by the filling device. The rotary press machine includes a pressure device, and the pressure device works in conjunction with the upper pressing punch and the lower pressing punch during the operation, and press-fits the powder materials into in the cavity of the die plate to generate pellets. The rotary press machine includes a control cam that works in conjunction with a punch head of the pressing punch to control the movement in the axial direction of the pressing punch. The control cam includes a discharge cam that controls the lower pressing punch to discharge the pellets produced in the cavity out of the cavity.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for evaluating the wear state of parts of a rotary press. This rotary press includes a rotor that can rotate using a rotary drive. This rotor includes an upper punch guide for an upper pressure punch, a lower punch guide for a lower pressure punch, and a die plate disposed between these punch guides. The pressure punch interacts with the cavity of the die plate. The rotary press further includes a filling device by which a powder material to be pressurized is filled into the cavity of the die plate, and the rotary press includes a pressure device that, during operation, cooperates with the upper and lower pressure punches to press the powder material in the cavity of the die plate into pellets. The rotary press includes a control cam that cooperates with the punch head of the pressure punch to control the axial movement of the pressure punch. The control cam includes a discharge cam that controls the lower pressure punch to discharge the pellets produced in the cavity from the cavity.

[0002] The present invention also relates to a rotary press. The rotary press includes a rotor that includes an upper punch guide for an upper pressure punch, a lower punch guide for a lower pressure punch, and a die plate disposed between these punch guides. The pressure punch interacts with the cavity of the die plate. The rotary press further includes a filling device by which a powder material to be pressurized is filled into the cavity of the die plate, and the rotary press further includes a pressure device that, during operation, interacts with the upper and lower pressure punches to press the powder material in the cavity of the die plate into pellets. The rotary press further includes a control cam that interacts with the punch head of the pressure punch to control the axial movement of the pressure punch. The control cam includes a discharge cam that controls the lower pressure punch to discharge the pellets produced in the cavity from the cavity.

[0003] A rotary press typically has multiple upper and lower pressure punches, each paired with one cavity in a die plate. During operation, the upper and lower pressure punches rotate with the die plate, and their axial movement is controlled by control cams and guided by upper and lower punch guides. While rotating, the die plate passes through various devices of the rotary press, namely the filling and pressure devices. In the filling device, the powder material to be pressurized is guided into the cavity of the die plate, and in the pressure device, the upper and lower pressure punches are typically pressed into the cavity by upper and lower pressure rollers to press the powder material into pellets, such as tablets. After the pressure device, the upper pressure punch is guided upward from the cavity, and the pellets produced in the cavity are pushed onto the upper surface of the die plate by the lower pressure punch. To achieve this purpose, an ejection cam is provided, which moves the lower pressure punch upward. For example, the pellets are then scraped out of the die plate into the output section of a rotary press, from where they are fed for further processing.

[0004] Rotary presses operate at high rotational speeds and, consequently, high production speeds. Across the numerous corresponding pressurizing processes, wear occurs on various parts of the rotary press, particularly the control cams, especially the discharge cams which experience specific stresses during contact with the press die. Contact with the powder material being pressed can also lead to corresponding wear. More worn parts can lead to a deterioration in pellet quality. For example, a more worn discharge cam may result in defects going undetected during sorting, leading to defective tablets not being removed. Historically, the wear condition of many rotary press parts, particularly the discharge cams, has been manually checked by the operator at set maintenance intervals. The drawback of this is that it is not timely to detect wear that may occur in between, potentially leading to a deterioration in tablet quality. Manual wear checks are also time-consuming and not reliably reproducible.

[0005] Therefore, based on the prior art described above, the object of the present invention is to provide a method and rotary press of the type described at the beginning that can reliably, promptly, and reproducibly evaluate the wear condition of the parts of a rotary press.

[0006] The present invention achieves this objective by independent claims 1 and 13. Advantageous embodiments are disclosed in the independent claims, specification, and drawings.

[0007] Regarding the type of method described at the beginning, the present invention achieves this objective by the following steps: The steps include: measuring the discharge force acting on the discharge cam during the operation of the rotary press as a measured value using at least one force sensor, and / or measuring the vibrations occurring during the operation of the rotary press as a measured value using at least one vibration sensor; The measurement values ​​are sent to an evaluation device, which then evaluates the wear condition of the rotary press machine parts based on the obtained measurement values.

[0008] With respect to the rotary press of the aforementioned type, the present invention achieves the objective in the following way: The rotary press is equipped with at least one force sensor, which can be used to measure the discharge force acting on the discharge cam during the operation of the rotary press, and / or the rotary press is equipped with at least one vibration sensor, which can be used to measure the vibrations occurring during the operation of the rotary press, A testing device is provided, to which measurement values ​​are sent, and the device is designed to evaluate the wear condition of the rotary press machine's parts based on the obtained measurement values.

[0009] As provided in accordance with the present invention and / or used in the method according to the present invention, the basic design of the rotary press is as described at the beginning. As described, upper and lower punch guides guide the press punch in axial motion. The punch head interacts with control cams that move the press punch axially, in particular, toward or toward each other, as it rotates in the rotor. The control cams are generally made up of multiple control cam elements. The control cams can house the punch head in a corresponding guide holder or be positioned only on the mirror surface of the punch head. The pressure device generally comprises an upper pressure roller and a lower pressure roller, which interact with the punch heads of the upper and lower press punches. Multiple pressure devices of this type may be provided, for example, a pre-pressure device and a main pressure device. The discharge cam, as part of the control cams, moves the lower press punch upward after pellets have been generated in their respective cavities, so that each pellet reaches the upper side of the die plate, from where it can be guided to the tablet outlet by a scraper fixedly positioned on top of the die plate, for example.

[0010] According to the present invention, the discharge force acting on the discharge cam during the operation of a rotary press is measured as a value by at least one force sensor, and / or the vibrations generated during the operation of the rotary press are measured by at least one vibration sensor. The values ​​are sent to an evaluation device. The evaluation device evaluates the wear condition of the rotary press components based on the obtained values. These components are, in particular, one of the aforementioned rotary press components. For example, these components may be elements of a control cam, such as a discharge cam. The present invention is based on the insight that wear of rotary press components is revealed, in particular, by changes in the discharge force of the discharge cam and / or by changes in vibrations generated during the operation of the rotary press. It is also useful to measure a combination of values, such as detecting both the discharge force measured by the force sensor and the vibration measured by the vibration sensor as values ​​and evaluating them in the evaluation device. When both types of values ​​are recorded, each can be evaluated in the manner described above and below. For example, in the comparison of recorded values ​​with reference values, the discharge force value is compared with a reference value for discharge force, and the vibration value is compared with a reference value for vibration. Then, the wear condition can be evaluated based on both types of values. For example, if one or both types of recorded measurements differ from the corresponding baseline values, it can be determined that the part is more worn. In particular, when both types of measurements are recorded and evaluated, influencing factors acting on one of the measurement types can be considered or each can be excluded, so that the measurements change but are not due to changes in the wear state. One example is the web height, i.e., the height of the pellets produced in the cavity, or the depth of penetration of the pressure plunger, especially the upper pressure plunger, into the cavity, or the depth of penetration of the lower pressure plunger when discharging pellets from the cavity, which has a particular effect on the discharge force. Furthermore, by considering vibration signals, it is possible to recognize and exclude such influencing factors that are not related to the wear state.

[0011] The evaluation device may be part of the rotary press. For example, the evaluation device can be integrated into the mechanical control unit of the rotary press. However, the evaluation device can also be designed independently of the rotary press, for example, on a computer, tablet, or smartphone, or it can be designed on a separate server from the rotary press within the context of a cloud solution.

[0012] The present invention allows for the prediction of wear on rotary press components, particularly in real time. This is done simply and reliably using measured signals of the discharge force of the discharge cam and / or the vibration of the rotary press. Since the wear condition evaluation according to the present invention can be performed independently of maintenance intervals, especially during continuous operation of the rotary press, it is possible to detect increased wear in a timely manner. This increases process stability and minimizes unexpected stoppages of the rotary press. At the same time, it becomes possible to permanently optimize the quality characteristics of the manufactured pellets. The evaluation according to the present invention is independent of individual evaluations by operators and is therefore highly reliable and objectively reproducible.

[0013] The evaluation device may include an input device and / or a display device. These may be integrated into the evaluation device or may be independent, for example, on a PC, tablet, smartphone, or especially an application.

[0014] The measurements recorded according to the present invention are particularly suitable for evaluating the wear condition of the discharge cam. The discharge cam is also relevant to the evaluation of its wear condition because its condition was not automatically monitored in advance. Within the context of the set maintenance interval, only manual checks are performed. According to the present invention, it has been found that the wear of the discharge cam can be reliably detected by the discharge force and vibration signal.

[0015] A force sensor that records the measured force of the ejection force can be placed on the ejection cam. Currently, force sensors that measure the ejection force are usually already placed on the ejection cam. However, these are not used to detect wear. For example, a force transducer can be mounted on the ejection cam as a force sensor. The force transducer may have, for example, a bending beam with a strain gauge and possibly an integrated measuring amplifier. A force transducer placed, for example, below the ejection cam is deflected by the force transmitted by the ejected punch. The ejection force can be measured using this deflection.

[0016] According to another embodiment, vibration sensors may be placed on the discharge cam and / or pressure device, particularly on the upper and / or lower pressure rollers of the pressure device, and / or on the upper and / or lower supports of the upper and / or lower pressure rollers, and / or on the metering cam of the control cam for metering the powder material filled in the cavity of the die plate. Thus, it is possible to provide one or more vibration sensors to record vibrations occurring during the operation of the rotary press as measured values. For example, a vibration sensor on the discharge cam, for example, a vibration sensor on the force transducer, for example, a vibration sensor on the bending measuring beam of the force transducer, directly measures vibrations occurring within the discharge cam and can therefore provide very direct information about the wear condition of the discharge cam. However, the inventors have found that vibration signals on the elements of the metering cam, i.e., the control cam elements that control (meter) the height of the lower punch when filling the cavity with powder material, and vibration signals on the pressure rollers of the pressure device also provide information about the wear condition of other parts located in the rotary press, particularly on the discharge cam. It is also useful to arrange and use multiple vibration sensors. In this way, other influences that are likely unrelated to the wear condition can be identified and excluded from the evaluation.

[0017] Measurements can be recorded as measurement curves, particularly time-dependent measurement curves. For example, measurements can be recorded as measurement curves plotted against time, velocity, or acceleration. Plotting measurements as measurement curves may already be done by force sensors or vibration sensors, or individual measurements provided by force sensors or vibration sensors may be recorded by an evaluation device to form a corresponding measurement curve. Particularly reliable information regarding the wear condition of a part can be obtained from the changes in the time characteristics of the recorded measurements.

[0018] In a highly practical manner, the wear condition of a part can be evaluated by an evaluation device based on a comparison of obtained measurements with reference values. The reference values ​​may be measurements taken during operation of a rotary press with a new corresponding part, such as a new discharge curve. These reference values ​​form a target value, which can then be compared with the measurements taken during operation of the rotary press obtained later. The reference values ​​may be historical data of the evaluated rotary press, or data stored in a database, such as data stored for each type of rotary press. By measuring the deviation of the currently recorded measurements from the reference value, it is possible to estimate the wear condition of each part. The influence of other factors unrelated to the wear condition, such as web height or pressure plunger penetration depth, can be eliminated by calculation or measurement, as already mentioned. In particular, if the measurements are recorded as a measurement curve, it is possible to compare the measurements with a reference curve.

[0019] According to another embodiment, the evaluation device detects increased wear of a part when the obtained measurement deviates from a reference value, and / or when the amplitude of the obtained measurement changes compared to the reference value, and / or when the slope of the obtained measurement changes compared to the reference value. What has been found is that, in particular, the time lag of the high-frequency vibration signal or high-frequency discharge force signal correlates with the degree of wear of the discharge curve of the rotary press. In addition to the lag, the magnitude and shape of the maximum value of the high-frequency vibration signal or high-frequency discharge force signal are also parameters indicating the wear state. For example, with respect to the discharge curve, the collision angle of the pressure punch in the inclined discharge curve changes due to wear caused by frequent force contact with the punch head. This leads to a corresponding lag and changed shape of the maximum value of the corresponding measurement curve. Wear of the discharge curve can also be recognized by changes in the levels of acceleration and the amplitude of the vibration signal and / or discharge force signal. This can also be considered by the evaluation device in the manner described above.

[0020] According to another embodiment, if the obtained measurement deviates from the reference value by at least one specified limit, the evaluation device can detect that the part has worn further. This at least one specified limit can be defined and / or adjusted by the operator. Alternatively, or additionally, this at least one specified limit can be defined and / or adjusted by an algorithm, particularly a machine learning algorithm. Thus, the corresponding limit can be defined by software in addition to the operator, or determined process-wise using a reference value for a new part, such as a new extrusion curve. Furthermore, machine learning algorithms, particularly self-learning algorithms, can be used to optimize or adjust the specified limits, respectively. For example, the operator can input the limit value via the input device of the evaluation device or adjust the limit value according to their respective requirements. The machine learning algorithm may include, in particular, a neural network.

[0021] The evaluation device can display the evaluation result of the wear state of the component to the operator. Furthermore, when it is detected that the component has further worn, the evaluation device can output a warning message. The display device of the above evaluation device can display the evaluation result or each warning message. The warning message may include a proposal for cleaning and / or reprocessing and / or replacement of more worn components.

[0022] A rotary press, particularly an evaluation device, can be designed to execute the method according to the present invention. Therefore, the method according to the present invention can be executed by using the rotary press according to the present invention.

Brief Description of the Drawings

[0023] Exemplary embodiments of the present invention will be described in more detail below with reference to the drawings.

[0024] [Figure 1] Schematic diagram showing the state of the unfolded rotor of the rotary press according to the present invention. [Figure 2] First figure showing the method according to the present invention. [Figure 3] Another figure showing the method according to the present invention. [Figure 4] Another figure showing the method according to the present invention. [Figure 5] Another figure showing the method according to the present invention.

[0025] Unless otherwise specified, the same reference signs refer to the same objects in the figures.

[0026] The rotary tablet press shown in Fig. 1 is a rotary tablet press for manufacturing tablets, in which powder materials are pressed into tablets. The rotary tablet press includes a rotor that is rotationally driven by a rotary drive, and the die plate 10 provided on the rotor has a plurality of cavities 12. The cavities 12 may be formed, for example, by holes in the die plate 10. The rotor further includes a plurality of upper pressing punches 14 and lower pressing punches 16, which rotate synchronously with the die plate 10. The upper pressing punches 14 are axially guided within the upper punch guides 18, and the lower pressing punches 16 are axially guided within the lower punch guides 20. The axial movement of the upper pressing punches 14 and the lower pressing punches 16 during the rotation of the rotor is controlled by the upper control cam element 22 and the lower control cam element 24. The rotary tablet press further includes a filling device 26, which includes a filling reservoir 28 and a filling chamber 30, which are connected via a filling pipe 32. Thus, in this embodiment, the powder material reaches from the filling reservoir 28 into the filling chamber 30 through the filling tube 32 by gravity, and from there, it reaches into the cavities 12 of the die plate 10 through the filling openings provided on the lower surface of the filling chamber 30.

[0027] The rotary tablet press further includes a pressure device 34. The pressure device 34 includes a pre-pressure device having an upper pre-pressure roller 36 held by an upper support portion 35 and a lower pre-pressure roller 38 held by a lower support portion 37, and a main pressure device having an upper pressure roller 40 held by an upper support portion 39 and a lower pressure roller 42 held by a lower support portion 41. Further, the rotary tablet press includes a discharging device 44 and a scraping device 46, and the scraping device 46 has a scraping element for supplying the tablets 48 manufactured by the rotary tablet press to a discharging device 50 for discharging the tablets from the rotary tablet press. The scraping device 46 may include, for example, a preferably crescent-shaped scraping element that scrapes the tablets 48 conveyed by the lower pressing punches 16 from the die plate 10 onto the upper surface of the die plate 10 in the region of the discharging device 44 and supplies them to the discharging device 50.

[0028] As will be described in more detail below, the rotary press further comprises an evaluation device 52 for controlling the operation of the rotary press and for carrying out the method according to the present invention.

[0029] The control cam 24 comprises various control cam elements, particularly a metering cam 54 and a discharge cam 56. In the illustrated example, vibration sensors 58, 60, and 62 are positioned on the metering cam 54, the upper and lower support sections 39 and 41 of the upper and lower pressure rollers 40 and 42, and the discharge cam 56. The vibration sensors 58, 60, and 62 measure vibrations generated during the operation of the rotary press at each of the components where they are positioned. In addition, a force sensor 64 is positioned on the discharge cam 56 to measure the discharge force acting on the discharge cam 56 by the pressure punches 14 and 16 during the operation of the rotary press. The measurements detected by the vibration sensors 58, 60, and 62 and the force sensor 64 during the operation of the rotary press are recorded as a measurement curve and sent to the evaluation device 52. Based on the obtained measurement curve, the evaluation device 52 evaluates the wear condition of the discharge curved section 56 of the rotary press in the illustrated example. The evaluation results, i.e., warning messages for each component if wear increases, can be output to the display device of the evaluation device 52. This may be incorporated into the evaluation device 52, or it may be formed in a computer, tablet, smartphone, etc. The evaluation device 52 also includes an input device through which the operator can input parameters for state evaluation by the evaluation device 52, such as limit values ​​for deviation from a reference curve. This input device may also be incorporated into the evaluation device 52, or it may be formed independently of the evaluation device 52, for example, in a computer, tablet, smartphone, etc.

[0030] In the illustrated example, the evaluation device 52 compares the recorded measurement curves of vibration sensors 58, 60, 62 and force sensor 64 with a reference curve that could, for example, be experimentally created using a new and unworn discharge curve 56. The reference curve can be created for the rotary press being evaluated or for another rotary press of the same type. In particular, the evaluation device 52 can detect an increase in wear of the discharge curve 56 if, for example, the obtained measurement curve is out of time compared to the reference curve, and / or the amplitude of the obtained measurement curve is different compared to the reference curve, in particular the changed maximum value, and / or the slope of the obtained measurement curve is different compared to the reference curve, in particular the slope or maximum value of the changed amplitude.

[0031] This will be explained using the diagrams shown in Figures 2 to 5 as examples. In Figure 2, the number 66 indicates the vibration frequency of vibrations generated during the operation of the rotary press machine, measured by a vibration sensor 62 located on the discharge cam 56, plotted against vibration acceleration in arbitrary units for each case. The corresponding reference value is shown in Figure 2 by reference numeral 68. On the other hand, the amplitude of the vibration signal measured by the vibration sensor 62, i.e., the maximum value, is larger than the reference value, and it can be seen that the vibration acceleration is also smaller. The evaluation device 52 compares the deviation of these recorded measurements from the reference value with the corresponding specified limit value. If the deviation exceeds the limit value, the evaluation device 52 evaluates that the discharge curved section 56 is more worn.

[0032] Figure 3 corresponds to Figure 2, in which, at reference numeral 70, the measured value recorded by the vibration sensor 58 located on the metering cam 54 is compared with the corresponding reference value and plotted at reference numeral 72. The overlap of curves 70 and 72 is shown in shaded area. The deviations identifiable in Figure 2 are less noticeable due to the placement of the vibration sensor 58 on the metering cam 54, but are also identifiable in Figure 3. As described in Figure 2, the evaluation device 52 can also evaluate the wear condition of the discharge curved section 56 based on the measured value of the vibration sensor 58.

[0033] Figure 4 is a slightly different diagram from Figures 2 and 3, showing the measurements recorded by the vibration sensor 60 located on the upper pressure roller 40. In Figure 4, the frequency of vibration against the vibration velocity is again plotted in arbitrary units. The measurements recorded by the vibration sensor 60 are indicated by reference numeral 74. The corresponding reference value for the new discharge cam 56 is also indicated by reference numeral 76. The overlap of curves 74 and 76 is again shown in shaded form. Again, the evaluation device 52 generates a deviation between the measured values ​​that is recognizable and comparable to the corresponding limit value. Thus, the amplitude of the frequency of the measured value 74, i.e., the maximum value of the frequency, is greater than the reference value 76. Furthermore, the vibration velocity is greater than the reference value. The evaluation device 52 can detect greater wear by comparing it to the corresponding specified limit value.

[0034] In Figure 5, the measured value curve of the discharge force recorded over time by the force sensor 64 located on the discharge cam 56 is plotted at reference numeral 78, and the corresponding reference value curve for the new discharge cam 56 is plotted at reference numeral 80. It can be clearly seen that the measured value curve 78 recorded by the force sensor 64 is temporally staggered with respect to the reference value curve 80. However, the amplitude of the measured value curve does not change significantly. Again, the limit value of the temporal staggerment of the measured value curve 78 with respect to the reference value curve 80 can be identified, and based on this, the evaluation device 52 can detect that the discharge cam 56 has become more worn.

[0035] The present invention has been described with reference to exemplary embodiments for evaluating the wear condition of the discharge cam 56, but naturally, the wear condition of other parts of the rotary press can also be evaluated as appropriate. [Explanation of Symbols]

[0036] 10… Die Plate 12... Cavity 14… Upper pressure punch 16... Lower pressure punch 18…Upper punch guide 20…Lower punch guide 22…Upper control cam element 24...Lower control cam element 26…Filling device 28... Filling reservoir 30…Filling Chamber 32… Filling tube 34… Pressurizing device 35...Upper support part 36… Upper preload roller 37…Lower support part 38... Lower preload roller 39...Upper support part 40… Upper pressure roller 41...Lower support part 42... Lower pressure roller 44…Discharge device 46...Scraping device 48... Tablets 50…Discharge device 52…Evaluation device 54... Measuring cam 56... Discharge Cam 58…Vibration sensor 60…Vibration sensor 62…Vibration sensor 64... Force sensor 66…Measured value 68…Reference value 70…Measured value 72…Reference value 74…Measured value 76…Reference value 78…Measured value 80...Reference value

Claims

1. A method for evaluating the wear condition of parts of a rotary press, wherein the rotary press comprises a rotor rotatable using a rotary drive, the rotor comprising an upper punch guide (18) for an upper pressure punch (14), a lower punch guide (20) for a lower pressure punch (16), and a die plate (10) positioned between the punch guides, the pressure punches (14, 16) interacting with the cavity (12) of the die plate (10), the rotary press further comprising a filling device (26), the filling device (26) filling the cavity (12) of the die plate (10) with powder material to be pressurized, and the rotary press The press machine is equipped with a pressure device (34), which, during operation, cooperates with the upper pressure punch (14) and the lower pressure punch (16) to press-fit powder material into the cavity (12) of the die plate (10) to form pellets, and the rotary press machine is equipped with a control cam that cooperates with the punch heads of the pressure punches (14, 16) to control the axial movement of the pressure punches (14, 16), and the control cam is equipped with a discharge cam (56) that controls the lower pressure punch to discharge the pellets produced in the cavity (12) from the cavity (12), and the method is characterized by comprising the following steps: - Using at least one force sensor (64), measure the discharge force acting on the discharge cam (56) during the operation of the rotary press as a measured value, and using at least one vibration sensor (58, 60, 62), measure the vibrations generated during the operation of the rotary press as a measured value. - A step in which the measured values ​​are sent to an evaluation device (52), and the evaluation device (52) evaluates the wear condition of the parts of the rotary press machine based on the obtained measured values.

2. The method according to claim 1, characterized in that the wear state of the discharge cam (56) is evaluated by the evaluation device (52).

3. The method according to claim 1, characterized in that a force sensor (64) is located on the discharge cam (56).

4. The method according to claim 1, characterized in that vibration sensors (58, 60, 62) are disposed on the discharge cam (56) and / or the pressure device (34), in particular on the pressure rollers (40, 42) of the pressure device (34) and / or on the support portions (39, 41) of the pressure rollers (40, 42) of the pressure device (34), and / or on the metering cam (54) of the control cam for metering the powder material filled in the cavity (12) of the die plate (10).

5. The method according to claim 1, characterized in that the measured values ​​are recorded as measurement curves, particularly time-dependent measurement curves.

6. The method according to claim 1, characterized in that the wear state of the part is evaluated by the evaluation device (52) based on a comparison of the obtained measured value with a reference value.

7. The method according to claim 6, characterized in that the evaluation device (52) detects an increase in wear of the part when the obtained measurement value deviates from a reference value, and / or when the amplitude of the obtained measurement value changes compared to a reference value, and / or when the slope of the obtained measurement value changes compared to a reference value.

8. The method according to claim 6, characterized in that if the obtained measurement value deviates from the reference value by at least one specified limit value, the evaluation device (52) detects that the part has worn further.

9. The method according to claim 8, characterized in that the at least one specified limit is defined and / or adjusted by an operator, and / or the at least one specified limit is defined and / or adjusted by an algorithm, particularly a machine learning algorithm.

10. The method according to claim 1, characterized in that the evaluation device (52) displays the results of the evaluation of the wear state of the part to the operator.

11. The method according to claim 1, characterized in that when it is detected that the aforementioned part has worn down further, the evaluation device (52) outputs a warning message.

12. The method according to claim 11, characterized in that the warning message includes a suggestion to clean and / or rework and / or replace the more worn part.

13. A rotary press comprising a rotor, the rotor comprising an upper punch guide (18) for an upper pressure punch (14), a lower punch guide (20) for a lower pressure punch (16), and a die plate (10) positioned between the punch guides, wherein the pressure punches (14, 16) interact with the cavity (12) of the die plate (10), the rotary press further comprising a filling device (26), the filling device (26) filling the cavity (12) of the die plate (10) with powder material to be pressurized, and the rotary press further comprising a pressure device ( 34) comprising the pressure device (34) which interacts with the upper pressure punch (14) and the lower pressure punch (16) during operation to press-fit the powder material in the cavity (12) of the die plate (10) into pellets, the rotary press further comprises control cams which interact with the punch heads of the pressure punches (14, 16) to control the axial movement of the pressure punches (14, 16), the control cams which comprises a discharge cam (56) which controls the lower pressure punch to discharge the pellets produced in the cavity (12) from the cavity (12), - The rotary press is equipped with at least one force sensor (64), and the force sensor (64) can be used to measure the discharge force acting on the discharge cam (56) during the operation of the rotary press as a measured value, and the rotary press is equipped with at least one vibration sensor (58, 60, 62), and the vibration sensors (58, 60, 62) can be used to measure the vibrations that occur during the operation of the rotary press as a measured value. A rotary press machine is provided with an evaluation device (52), to which measured values ​​are sent, and the evaluation device (52) is designed to evaluate the wear condition of the parts of the rotary press machine based on the obtained measured values.

14. The method according to claim 13, characterized in that a force sensor (64) is located on the discharge cam (56).

15. The method according to claim 13, characterized in that vibration sensors (58, 60, 62) are located on the discharge cam (56) and / or the pressure device (34), in particular on the pressure rollers (40, 42) of the pressure device (34) and / or on the metering cam (54) of the control cam for metering the powder material filled in the cavity (12) of the die plate (10).

16. The rotary press according to claim 13, characterized in that the rotary press, in particular the evaluation device (52), is designed to perform the method according to any one of claims 1 to 12.

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