WO2023006753A1

WO2023006753A1 - Manufacturing tool, method for determining a state of wear, and use of a pneumatic sensor

Info

Publication number: WO2023006753A1
Application number: PCT/EP2022/070955
Authority: WO
Inventors: Matthias Menzl; Maximilian LORENZ; Christian Donhauser; Matthias Strauss
Original assignee: Hochschule für angewandte Wissenschaften Kempten
Priority date: 2021-07-30
Filing date: 2022-07-26
Publication date: 2023-02-02
Also published as: DE102021119874A1

Abstract

The invention relates to a manufacturing tool (1), in particular a forming tool and/or a cutting tool. The manufacturing tool (1) comprises an active element (2), mounted so as to be movable along its longitudinal axis (L), with a distal end formed as a processing portion (6), in particular as a forming portion and/or cutting portion. Furthermore, the manufacturing tool (1) comprises a passive element (3; 4; 5) with a recess (9). The recess (9) has a cross-sectional contour which corresponds to the cross-sectional contour of the processing portion (6), and into which the processing portion (6) passes during operation of the manufacturing tool (1). Moreover, the manufacturing tool (1) comprises at least one pneumatic sensor (7) received on or in the passive element (3; 4; 5). The pneumatic sensor (7) has a sensing region which extends into the recess (9). The at least one pneumatic sensor (7) senses a stagnation pressure within the recess (9). Finally, the manufacturing tool (1) comprises an evaluation unit by means of which a state of wear of the processing portion (6) is deduced from the sensed stagnation pressure. The invention also relates to a method for determining a state of wear and to the use of a pneumatic sensor.

Description

PRODUCTION TOOLING, METHOD OF DETERMINING A WEAR CONDITION AND USE OF A PNEUMATIC SENSOR

FIELD OF THE INVENTION

The invention relates to a production tool, in particular a forming tool and/or a separating tool, with a pneumatic sensor, a method for determining a state of wear and use of a pneumatic sensor for determining a state of wear.

BACKGROUND

Production tools, in particular forming tools and/or cutting tools such as punching tools, comprise movably mounted active elements with an end designed as a processing section. When the production tools are used, the processing section wears out, in particular as the operating time of the active element or processing section increases. This wear means that the forming and/or separating of the parts to be formed and/or to be separated loses accuracy, so that the formed and/or separated parts no longer meet the specifications and may have to be discarded as scrap parts. If there is too much wear, the active element can also break, for example, which can lead to damage to the entire production tool and a longer-lasting loss of production. Therefore, monitoring the state of wear and/or spontaneous failure of the machining section in production tools is of great importance.

This monitoring can be carried out, for example, by operators of the production tool, but only when the production tool is not in operation and with appropriate safety precautions. Continuous monitoring is therefore not possible, the operation of the production tool must be interrupted for monitoring and the test must be carried out by the operating personnel. A further possibility of determining the state of wear of the machining section is given by measuring the ram force or the ram pressure of the active element, for example by means of piezo sensors. However, these measurements only provide a very imprecise result.

In addition, the noise emitted by the production tool during forming and/or cutting can be measured and analyzed. Changes in the noise indicate wear of the machining section. Since there are a large number of influencing parameters on the noise, a measurement of the emitted noise only provides very imprecise information about the state of wear of the machining section.

Furthermore, the wear of the machining section during operation of the production tool can be determined by means of optical sensors. However, due to contamination, which is regularly encountered in forming tools, such optical sensors can quickly become soiled, which has a negative effect on the function or measurement accuracy.

SUMMARY

It is the object of the invention to propose an improved production tool and an improved method for determining the state of wear of a machining section, which in particular overcomes the disadvantages mentioned above, i.e. are robust and precise and determine the state of wear of the machining section during ongoing operation. This object is solved by the subject matter of the independent patent claims. Further developments of the invention result from the dependent claims and the following description.

One aspect of the invention relates to a production tool, in particular a forming tool and/or a separating tool such as a stamping tool. The production tool is in particular a tool for forming and/or separating hot- or cold-formable materials. The production tool includes an active element and a passive element. The active element is movably mounted along its longitudinal axis. The active element is a stamp, for example. A distal end of the active element is designed as a processing section, with the "distal end" of the active element being understood as that end of the active element which is to be understood during operation of the production tool, i.e. when the active element is arranged in the production tool or when the active element is used to form or to separating workpiece is formed or separated, facing the workpiece to be formed and/or to be separated. The phrase "a distal end of the active element is designed as a processing section" is also intended to include an embodiment in which the processing section is not a direct part of the active element (i.e in which the processing section and active element are not formed in one piece), but the processing section is an independent component which, during operation of the production tool, can be connected at the end of the active element facing the workpiece, for example via a connecting means, in particular via a speed-translating means connected to said end of the active element so as to form, together with the active element and the connecting means, a kinematic chain in which the processing section represents the "distal end". The use of a speed-translating means can be advantageous above all in those cases in which particularly high relative speeds of the machining section in relation to the workpiece are required for forming and/or cutting the workpiece; the processing section then preferably moves faster than the active element, for example at least twice as fast. The processing section is designed in particular as a cutting edge, as a punching blade, as an embossing die and/or as a bending die. During operation of the production tool, the active element is moved along its longitudinal axis and a workpiece is formed and/or separated by means of the machining section.

The passive element is an element with respect to which the active element is movable; it includes a recess. A cross-sectional contour of the recess corresponds to the cross-sectional contour of the machining section. This means in particular that a cross-sectional contour of the recess and a cross-sectional contour of the processing section are designed in such a way that the processing section moves during operation of the production tool can move at least in sections into and out of the recess. According to a preferred embodiment, the two said cross-sectional contours are essentially identical (taking into account any manufacturing tolerances and/or a cutting gap). If a cross-sectional contour of the recess is circular, for example, the cross-sectional contour of the processing section is also circular according to the preferred embodiment, in particular circular with a substantially identical radius of curvature. During operation of the production tool, the machining section of the active element dips into the recess of the passive element, as a result of which in particular a workpiece that is arranged between the passive element and the active element is formed and/or separated. In order for the active element to be able to dip into the recess, a cross section of the part of the processing section that dips into the recess is smaller than a cross section of the recess. In particular, a part with a cross-sectional contour that corresponds to the cross-sectional contour of the machining section is punched out of the workpiece. Depending on the active element used and the design of the processing section associated therewith, punching out and/or embossing can take place, for example. In the case of embossing, the processing section does not have a cutting edge (the active element is then in the form of an embossing stamp) and the part of the workpiece that is under the influence of the processing section is not separated from it but merely removed from its original position while maintaining a material connection to the rest of the workpiece placed in a different position from the rest of the workpiece.

Furthermore, the production tool comprises at least one pneumatic sensor accommodated on or in the passive element. A pneumatic sensor is understood to mean a sensor which is designed to introduce compressed air at a predetermined point and to detect a dynamic pressure generated by this compressed air. The pneumatic sensor has a detection area that extends into the recess of the passive element. The pneumatic sensor is therefore designed to detect a dynamic pressure within the recess.

During operation of the production tool, there is a change in the dynamic pressure within the recess over time. This temporal change is due in particular to the fact that the parts of the Active elements that are in the detection range of the pneumatic sensor change during a production cycle. In particular, the pneumatic sensor is placed in such a way that the processing section is located at least temporarily in the detection range of the pneumatic sensor. By using several pneumatic sensors, the state of wear of several areas of the production tool can be determined.

The production tool also includes an evaluation unit. This evaluation unit is designed to derive a state of wear of the machining section from the detected dynamic pressure. The greater the wear of the machining section, the less of the machining section is in the detection range of the pneumatic sensor at a given point in time of a production cycle and the lower the dynamic pressure that develops. The state of wear of the machining section can thus be determined by evaluating the dynamic pressure. The evaluation unit includes, for example, an interface for receiving the signals generated by the pneumatic sensor and a computing unit that evaluates these signals. During the evaluation, for example, the measured time-dependent dynamic pressure is compared with a reference curve of the dynamic pressure for a new, unworn machining section and the difference is used as a measure of the state of wear of the machining section.

As described above, the pneumatic sensor can be used while the production tool is in operation, so that it is not necessary to interrupt the operation of the production tool in order to determine the state of wear of the machining section. Furthermore, with a pneumatic sensor, the state of wear of the machining section can be determined with good precision. And finally, the compressed air from the pneumatic sensor blows dirt away from the pneumatic sensor so that the measurement result is not falsified by dirt.

In some embodiments, the passive element is or includes a stamping die. This means that when cutting a workpiece, the workpiece is initially between the active element and the punching die. The active element is then moved in such a way that at least the processing section of the active element dips into the recess of the punching die, as a result of which a part whose cross-sectional contour corresponds to the cross-sectional contour of the processing section and the recess is stamped out of the workpiece. The arrangement of the pneumatic sensor in the punching die has the advantage that the punching die is usually immobile and only the movement of the active element has to be taken into account in the evaluation. Alternatively, the passive element is or includes a guide plate. When the production tool is in operation, the guide plate is arranged on a side of the workpiece opposite a stamping die and is used to guide the active element, in particular perpendicularly to its direction of movement. Alternatively, the passive element is or comprises a hold-down plate, which is designed to hold the workpiece between the same and a punching die during operation of the production tool while the active element forms the workpiece and/or punches out a part of the workpiece.

Furthermore, several pneumatic sensors can also be arranged in such a way that some of them are located in the stamping die, others in the guide plate and/or others in the hold-down plate. In this way, the state of wear of the machining section can be determined at various points of the lifting movement of the machining section.

In some embodiments, the at least one pneumatic sensor is arranged at a dead center of a lifting movement of the processing section that lies in the passive element. The dead center can be, for example, a dead center of the relative movement of the guide plate and the active element. That is, the pneumatic sensor is arranged at one of the points at which the machining section reverses its movement during operation of the production tool. This reversal of movement means in particular a change in the direction of movement of the machining section from a movement directed towards the workpiece to be formed and/or separated to a movement directed away from the workpiece to be formed and/or separated or vice versa. At this dead center, the machining section moves particularly slowly and for a short time not at all, so that a precise determination of the state of wear of the machining section is possible. The pneumatic sensor can also be arranged at other, predetermined points in the passive element. At these points, the speed of the processing section when it passes the pneumatic sensor is not zero, and this speed must be taken into account when evaluating the recorded dynamic pressure. However, a machine stop can also be requested to detect the state of wear of the machining section, with the active element being placed when the machine stops in such a way that the machining section is located in the detection range of the pneumatic sensor.

In some embodiments, the at least one pneumatic sensor is installed directly in the passive element. This means that there is a hole for each pneumatic sensor in the passive element, in which the pneumatic sensor can be precisely accommodated. The term "borehole" is generally understood to be an elongated recess. It is also conceivable that lines, for example in the form of hoses, are introduced into this recess. In this way, the rigidity and load-bearing capacity of the passive element is only minimally impaired.

In some embodiments, the at least one pneumatic sensor is built into a sensor housing. This means that the passive element has a recess that corresponds at least to the size of the sensor housing, and the at least one pneumatic sensor is located in this sensor housing. The sensor housing can act as part of the guide plate, for example. A plurality of pneumatic sensors can be located in a sensor housing and/or a plurality of sensor housings can be provided for accommodating a plurality of pneumatic sensors. The introduction of the pneumatic sensor into the sensor housing is possible at low cost. Furthermore, a replacement of a pneumatic sensor, for example in the event of a defect in the pneumatic sensor, can be carried out easily. Finally, arranging the pneumatic sensor in a sensor housing offers great flexibility, since the pneumatic sensors can be arranged largely freely within the sensor housing.

In some embodiments, the at least one pneumatic sensor is movably mounted with respect to the passive element. The pneumatic sensor can be carried with the machining section to accurately measure the state of wear of the machining section. That is, for a given period of time, the speed of the Relative movement between the pneumatic sensor and the processing section less than the speed of the relative movement between the passive element and the processing section. In particular, the speed of the relative movement between the pneumatic sensor and the processing section is zero, at least temporarily, that is to say the movement of the pneumatic sensor and the processing section is synchronous. Due to the small speed differences between the pneumatic sensor and the processing section or due to an identical speed of the pneumatic sensor and processing section, particularly precise measurements of the state of wear of the processing section can be carried out. The movable mounting of the pneumatic sensor can take place via a spring. In order to carry the pneumatic sensor along with the forming section, the pneumatic sensor is preferably movably mounted via a mechanical coupling which at least partially transmits the movement of the active element to the pneumatic sensor and/or via a servomotor which at least partially carries the pneumatic sensor along with the processing section .

In some embodiments, the at least one pneumatic sensor is a ring sensor and/or a throat sensor. Alternatively or additionally, the at least one pneumatic sensor includes a nozzle or a bore. If there are several pneumatic sensors, they can also be designed differently, for example in order to measure with different accuracies or to detect different states of wear.

In some embodiments, a spatial resolution of the at least one pneumatic sensor is less than or equal to 4 pm, preferably less than or equal to 1 pm, particularly preferably less than or equal to 0.3 pm. In this way, the state of wear of the machining section can be determined with good precision.

A further aspect of the invention relates to a method for determining a state of wear of a machining section of an active element of a production tool. The production tool is in particular a forming tool and/or a separating tool and the processing section is in particular a cutting edge or a punching knife. Furthermore, the production tool has a passive element with a recess into which the machining section dips during operation of the production tool. In the method, compressed air is introduced into the recess of the passive element via at least one pneumatic sensor. The resulting back pressure within the recess is detected by the pneumatic sensor and the wear condition of the machining section is determined via the back pressure detected. If the machining section is not worn, it is close (ie at a short distance, for example in the range from 2 μm to 5 μm) to the pneumatic sensor, so that a high dynamic pressure develops. However, if the machining section is already worn, then parts of the machining section are missing, in particular at an edge of the machining section. Due to these missing parts, the machining section is further away from the pneumatic sensor (ie at a greater distance, for example in the range from 20 μm to 100 μm) than in the unworn machining section, so that a lower dynamic pressure develops compared to the unworn machining section. The state of wear of the machining section can be determined via this difference in dynamic pressure. This determination of the state of wear of the machining section is possible while the production tool is in operation and is insensitive to contamination.

In some embodiments, the compressed air is introduced perpendicularly to a longitudinal axis along which the active element is movably mounted. A detection range of the pneumatic sensor can thus be determined particularly easily and the evaluation of the detected dynamic pressure is simplified.

In some embodiments, the at least one pneumatic sensor at least partially follows the movement of the processing section. The state of wear of the processing section can be determined particularly precisely by a substantially synchronous movement of the pneumatic sensor and processing section. The pneumatic sensor can be carried along mechanically with the processing section. As an alternative to this, the pneumatic sensor can also follow the processing section in a separately controlled manner, for example via an electric motor drive and a corresponding controller.

In some embodiments, the method is performed after a predetermined number of strokes of the active element. A predetermined number greater than one is in particular This is advantageous when the method is not carried out during normal operation of the production tool, for example when the active element is stopped to carry out the method or when the method is only carried out when there is no workpiece in the production tool. In particular, if it can be assumed that wear will not occur suddenly but rather gradually, the measuring effort can be reduced considerably.

The predetermined number of strokes is preferably reduced as the wear on the machining section increases and/or as the operating time of the machining section increases. It is therefore possible, for example, to select a large predetermined number of strokes, e.g. 20, for a new, unworn machining section, since rapid wear is not to be expected here. However, if the machining section is already worn or has been in operation for a longer period of time, the specified number of strokes is reduced in order to more precisely determine the point in time at which the machining section has to be replaced due to excessive wear.

In some specific embodiments, in order to carry out the method, the speed and/or the acceleration of the machining section is reduced compared to an operating state of the production tool in which no wear state is determined. By reducing the speed or the acceleration of the machining section, a more precise determination of the state of wear of the machining section is possible. In this case, too, it is advantageous if the specified number of strokes, after which the method is carried out, is greater than one, so that strokes at full speed of the production tool can also be carried out between strokes with measurement of the state of wear, so that high productivity of the production tool can be achieved Manufacturing tool is achieved.

In some embodiments, a warning is issued and/or an emergency stop of the production tool is carried out when a predetermined state of wear is detected. A warning can be issued or an emergency stop can be carried out, for example, depending on other parameters of the production tool, for example the speed and/or the stroke length of the machining section or the required accuracy of the forming and/or cutting process. For example, with a faster Machining section is also more likely to be expected to break the machining section than with a slower machining section. Likewise, if a higher accuracy is required in the forming and/or cutting process, the machining section may have to be replaced when the state of wear is lower than in a forming and/or cutting process in which the accuracy requirements are not as high.

By providing for a warning to be issued or an emergency stop to be carried out, an occupational health and safety requirement/guideline may also be met; for example, an emergency stop can prevent people who are in the vicinity of the production tool from being injured if the machining section breaks while the production tool is in operation.

A further aspect of the invention relates to the use of a pneumatic sensor for determining a state of wear of a machining section of an active element of a production tool. This determination is made by introducing compressed air into a recess of a passive element of the production tool and detecting a dynamic pressure in the recess. The dynamic pressure depends on the distance between objects located in the detection range of the pneumatic sensor and the pneumatic sensor, with this distance increasing as the wear of the processing section increases and the dynamic pressure thus becoming lower. The state of wear of the machining section can thus be determined by means of the pneumatic sensor while the production tool is in operation, with the pneumatic sensor being insensitive to contamination.

It goes without saying that a preferred embodiment can also be achieved from a combination of dependent claims with the respective independent claim.

For further clarification, the invention is described using the embodiments shown in the figures. These embodiments are meant to be exemplary only and not limiting.

BRIEF DESCRIPTION OF THE FIGURES

It shows: 1 shows a schematic cross section through a production tool;

2 shows a schematic view of a machining section;

Fig. 3 shows a schematic cross section of an embodiment of a

production tool;

Fig. 4 shows a schematic cross section of a further embodiment of a

production tool;

Fig. 5 shows a schematic cross section of yet another embodiment of a

production tool;

Fig. 6 shows a schematic cross section of yet another embodiment of a

production tool;

Fig. 7 shows a schematic cross section of yet another embodiment of a

production tool;

Fig. 8 shows a schematic cross section of yet another embodiment of a

production tool; and

Fig. 9 shows a schematic cross section of yet another embodiment of a

production tool.

DETAILED DESCRIPTION OF EMBODIMENTS

In the figures, the same reference symbols denote either the same elements or elements with equivalent functions. Elements that have already been described are not necessarily described again in subsequent figures.

Figure 1 shows a schematic cross section through a production tool 1, which is designed as a cutting tool. The production tool 1 comprises an active element 2 which is mounted so that it can move along its longitudinal axis L and is in the form of a stamp here.

The active element 2 is guided in a guide plate 3 so that movement of the active element 2 in a direction perpendicular to the longitudinal axis L of the active element 2 is prevented. A hold-down plate 4 adjoins the guide plate 3 and fixes a workpiece (not shown here) between the hold-down plate 4 and a punching die 5 during the cutting process. The downward movement of the active element 2 turns the fixed workpiece into a Part punched out, the cross-sectional contour of a cross-sectional contour of a formed at a distal end of the active element 2 processing section 6 corresponds.

A detailed view of the processing section 6 of the active element 2 is shown in FIG. The processing section 6 shown already shows wear, which is indicated by the shaded areas. Wear causes the result of the cutting process to deteriorate, so that from a certain state of wear it is necessary to replace the machining section 6 in order to obtain the desired quality of the cutting process. Furthermore, it is also possible that the machining section 6 breaks in a certain state of wear, in which case the fragments can then damage other parts of the production tool 1 or persons in the vicinity of the production tool. For this reason, too, it is advantageous to replace the machining section 6 before such a breakage of the machining section 6 occurs.

For this purpose, the state of wear of the machining section 6 is determined. A first embodiment of a production tool 1, with which the state of wear of the machining section 6 can be determined, is shown in FIG. Two pneumatic sensors 7 are arranged in hold-down plate 4 . For this purpose, the hold-down plate 4 was provided with bores that also function as compressed air lines 8 . "Boreholes" are generally understood to be elongated recesses. Furthermore, lines, for example in the form of hoses, can be introduced into these recesses.

The number of pneumatic sensors 7 is at least one, but a larger number of pneumatic sensors 7 can be used, thereby better detecting the state of wear of the processing section 6 along the cross-sectional contour of the processing section 6 .

In the present embodiment, the pneumatic sensors 7 are arranged at a top dead center of the lifting movement of the processing section 6 . At this top dead center, the speed of the machining section 6 is low and briefly zero, so that an exact determination of the state of wear of the machining section 6 is possible. To determine the state of wear, compressed air is introduced into a recess 9 of the hold-down plate 4 via the compressed air line 8 . Depending on which part of the processing section 6 extends into a detection range of the pneumatic sensor 7 and how close this part of the processing section 6 is to the pneumatic sensor 7, a dynamic pressure of different magnitude is formed. The newer and less worn the processing section 6 is, the closer it is to the pneumatic sensor 7 and the greater the dynamic pressure that is formed. On the other hand, if the processing section 6 is already showing signs of wear, then the distance from the pneumatic sensor 7 is greater and the dynamic pressure that is formed is lower.

The back pressure is detected by the pneumatic sensor 7 and then evaluated by an evaluation unit (not shown), with the detected back pressure being used to infer a state of wear of the machining section 6 .

In this way, the state of wear of the machining section 6 can be determined while the production tool 1 is in operation. The determination achieves a high degree of precision and the pneumatic sensors 7 are not affected by dirt, especially since possible dirt is blown away by the compressed air.

FIG. 4 shows a further embodiment of a production tool 1. In this embodiment, the pneumatic sensors 7 are each installed in a sensor housing 10, which is located in the hold-down plate 4. In this way, the pneumatic sensors 7 can be replaced more easily, for example in the event of a defect. Furthermore, the pneumatic sensors 7 can be repositioned relatively easily in this way, for example if the stroke of the active element 2 is changed and the top dead center of the stroke movement of the processing section 6 thus changes.

In the embodiment of a production tool 1 shown in FIG. 5, the sensor housings 10 are arranged at the end of the hold-down plate 4 on the workpiece side. Such an arrangement allows the pneumatic sensors 7 to be arranged particularly close to the workpiece. FIG. 6 shows a further embodiment of a production tool 1 in which the sensor housings 10 are mounted on the hold-down plate 4 via springs 11 . As a result, a speed of the relative movement between the pneumatic sensor 7 and the machining section 6 is reduced, so that an even more precise measurement of the state of wear of the machining section 6 is made possible.

In the embodiment of a production tool 1 shown in FIG. 7, the sensor housings 10 are mounted on the hold-down plate 4 via a servomotor 12, shown only schematically. The servomotor 12 is operated in such a way that the movements of the processing section 6 and the pneumatic sensors 7 run synchronously over a range of the lifting movement of the processing section 6, i.e. a relative speed between the pneumatic sensor 7 and the processing section 6 is preferably zero. A particularly good determination of the state of wear of the machining section 6 is thus possible. As an alternative to the servomotor 12 , a mechanical coupling can also bring about the synchronous course of the pneumatic sensors 7 with the processing section 6 .

In the embodiment of a production tool 1 shown in FIG. 8, the pneumatic sensors 7 are arranged in bores in the stamping die 5 . Again, "bores" are generally understood as elongated recesses. Furthermore, lines, for example in the form of hoses, can be introduced into these recesses. The arrangement is chosen such that the pneumatic sensors 7 are in a bottom dead center of the lifting movement of the processing section 6. Due to the arrangement of the pneumatic sensors 7 in the stamping die 5, the pneumatic sensors 7 are stationary, which simplifies the evaluation of the signals from the pneumatic sensors 7.

The embodiment of a production tool 1 shown in FIG. 9 differs from the embodiment shown in FIG. 8 in that the pneumatic sensors 7 are each built into a sensor housing 10 . In this way, the pneumatic sensors 7 can be replaced more easily, for example in the event of a defect. Furthermore, the pneumatic sensors 7 can be repositioned relatively easily, for example if the hub of the active element 2 is changed and thus the bottom dead center of the lifting movement of the processing section 6 changes.

In further embodiments not shown here, the pneumatic sensors 7 can also be arranged in the guide plate 3 . It is also possible for the pneumatic sensors 7 to be arranged at different points on the passive element of the production tool 1 , ie in the stamping die 5 , in the hold-down plate 4 and/or in the guide plate 3 .

Claims

PATENT CLAIMS

1. Production tool (1), in particular a forming tool and/or separating tool, comprising an active element (2) mounted so that it can move along its longitudinal axis (L) and having a distal end designed as a processing section (6), in particular as a forming section and/or separating section; a passive element (3; 4; 5) with a recess (9) which has a cross-sectional contour which corresponds to the cross-sectional contour of the machining section (6) and into which the machining section (6) dips when the production tool (1) is in operation; at least one pneumatic sensor (7) accommodated on or in the passive element (3; 4; 5) with a detection range, the detection range of the pneumatic sensor (7) extending into the recess (9) and the at least one pneumatic sensor (7) is designed to detect a dynamic pressure within the recess (9); and an evaluation unit which is designed to derive a state of wear of the machining section (6) from the detected dynamic pressure.

2. Production tool (1) according to claim 1, wherein the passive element (3; 4; 5) is or comprises a stamping die (5), a guide plate (3) and/or a hold-down plate (4).

3. Production tool (1) according to claim 1 or 2, wherein the at least one pneumatic sensor (7) is arranged in a dead center of a lifting movement of the processing section (6), which is in the passive element (3; 4; 5).

4. Production tool (1) according to one of claims 1 to 3, wherein the at least one pneumatic sensor (7) is movably mounted in relation to the passive element (3; 4; 5), in particular via a spring (11), a mechanical coupling and/or a servomotor (12).

5. Production tool (1) according to one of claims 1 to 4, wherein the at least one pneumatic sensor (7) is a ring sensor and/or a throat sensor.

6. Production tool (1) according to one of claims 1 to 5, wherein a spatial resolution of the at least one pneumatic sensor (7) is less than or equal to 4 pm, preferably less than or equal to 1 pm, particularly preferably less than or equal to 0.3 pm.

7. Method for determining a state of wear of a machining section (6) of an active element (2) of a production tool (1), wherein compressed air is fed into a recess (9) of a passive element (3; 4; 5) of the production tool via at least one pneumatic sensor (7). (1) is brought in; a dynamic pressure within the recess (9) is detected; and the state of wear of the machining section (6) is determined via the recorded dynamic pressure.

8. The method according to claim 7, wherein the compressed air is introduced perpendicular to a longitudinal axis (L) along which the active element (2) is movably mounted.

9. The method according to claim 7 or 8, wherein the at least one pneumatic sensor (7) at least partially follows the movement of the processing section (6).

10. The method according to any one of claims 7 to 9, wherein the method is carried out after a specified number of strokes of the active element (2), the specified number of strokes preferably increasing with increasing wear of the processing section (6) and/or with increasing service life of the

Processing section (6) is reduced.

11. The method according to any one of claims 7 to 10, wherein to carry out the method the speed and/or the acceleration of the machining section (6) is reduced compared to an operating state of the production tool (1) in which no wear state is determined.

12. Use of a pneumatic sensor (7) to determine a state of wear of a machining section (6) of an active element (2) of a production tool (1) by introducing compressed air into a recess (9) of a passive element (3; 4; 5) of the production tool ( 1) and detecting a dynamic pressure in the recess (9).