DEVICE FOR KNIFE CUTTING OR SAWING OF WORKPIECES WITH MONITORING OF STRIP DAMAGE, METHOD FOR MONITORING THE CONDITION OF DAMAGE OF A BAND KNIFE OR BAND SAW

Abstract

The invention relates to a device for knife cutting or sawing workpieces, with an endless, circumferential band knife (26) or an endless, circumferential band saw, respectively, wherein the device (10) has at least one sensor (42a, 42b, 42c, 42d, 42e, 42f), wherein the at least one sensor (42a, 42b, 42c, 42d, 42e, 42f) acquires a measuring value representing the band damage and wherein the sensor (42a, 42b, 42c, 42d, 42e, 42f) is connected to at least one evaluation unit (44) and the measuring value representing the band damage is supplied to the evaluation unit (44) and wherein based on the measuring value, information about the damage state of the band knife (26) or of the band saw can be generated by means of the evaluation unit (44).

Claims

1. A device for knife cutting or sawing workpieces, with an endless, circumferential band knife (26) or an endless, circumferential band saw, respectively, wherein the device (10) has at least one sensor (42a, 42b, 42c, 42d, 42e, 42f), wherein the at least one sensor (42a, 42b, 42c, 42d, 42e, 42f) acquires a measuring value representing a band damage and wherein the at least one sensor (42a, 42b, 42c, 42d, 42e, 42f) is connected to at least one evaluation unit (44) and the measuring value representing the band damage is supplied to the at least one evaluation unit (44) and wherein based on the measuring value, information about a damage state of the endless, circumferential band knife (26) or of the endless, circumferential band saw is generated by means of the at least one evaluation unit (44).

2. The device according to claim 1, characterized in that the at least one sensor (42a) directly or indirectly measures a displacement path of a tensioning roller (28c), wherein the endless, circumferential band knife (26) or the endless, circumferential band saw, respectively, is tensioned to a defined band tension by means of the tensioning roller (28c).

3. The device according to claim 1, characterized in that the at least one sensor (42f) directly or indirectly measures an acting force of a tensioning roller (28c), wherein the endless, circumferential band knife (26) or the endless, circumferential band saw, respectively, is tensioned to a defined band tension by means of the tensioning roller (28c).

4. The device according to claim 1, characterized in that the at least one sensor is a temperature sensor (42b, 42c), for indirectly or directly detecting a temperature of the endless, circumferential band knife (26) or of the endless, circumferential band saw, respectively.

5. The device according to claim 1, characterized in that the at least one sensor is an acceleration sensor (42d, 42e), for measuring vibrations caused by the endless, circumferential band knife (26) or the endless, circumferential band saw, respectively.

6. A method for monitoring a damage state of an endless, circumferential band knife (26) or of an endless circumferential band saw, respectively, wherein at least one measuring value representing band damage is detected and information about the damage state of the endless, circumferential band knife (26) or of the endless, circumferential band saw, respectively, is generated on the basis of the at least one measuring value.

7. The method according to claim 6, characterized in that the information about the damage state is generated among others by means of a machine-learning algorithm.

8. The method according to claim 6, characterized in that a remaining service life of the endless, circumferential band knife (26) or of the endless, circumferential band saw is generated as the information about the damage state.

9. The method according to claim 6, characterized in that a recommendation is issued with regard to an optimization of a cutting or sawing process, respectively.

10. A computer program, including machine-readable instructions, which, when they are executed on one or several computers, cause the computer or the computers to carry out a method comprising: monitoring a damage state of an endless, circumferential band knife (26) or of an endless circumferential band saw, respectively, wherein at least one measuring value representing band damage is detected and information about the damage state of the endless, circumferential band knife (26) or of the endless, circumferential band saw, respectively, is generated on the basis of the at least one measuring value.

11. (canceled)

12. The computer program of claim 10, characterized in that the information about the damage state is generated among others by means of a machine-learning algorithm.

13. The computer program of claim 10, characterized in that a remaining service life of the endless, circumferential band knife (26) or of the endless, circumferential band saw is generated as the information about the damage state.

14. The computer program of claim 10, characterized in that a recommendation is issued with regard to an optimization of a cutting or sawing process, respectively.

Description

[0067] Further practical embodiments and advantages are described in combination with the figures, in which:

[0068] FIG. 1 shows a horizontal contour cutting machine in a schematic illustration in a view from the front,

[0069] FIG. 2 shows the region from FIG. 1, which is identified with II, in an enlarged view

[0070] FIG. 3 shows the region from FIG. 1, which is identified with III, in an enlarged view,

[0071] FIG. 4 sows the region from FIG. 1, which is identified with IV, in an enlarged view,

[0072] FIG. 5 shows a flowchart of a method according to a first embodiment.

[0073] A device for knife cutting or sawing and, specifically here, a horizontal contour cutting machine 10 is shown in a schematic illustration in FIG. 1.

[0074] The cutting machine 10 has a machine stand 12 and a frame 14 arranged thereon. The machine stand 12 serves the purpose of setting up the cutting machine 10 on the floor and of receiving a table 16, which can be moved in the y direction. In the present case, the table 16 has two support surfaces 18 for one workpiece 20 each. In the present case, a workpiece 20 (only illustrated schematically here) is arranged on a support surface 18 of the table 16.

[0075] In the present case, the frame 14 is formed by two side parts 22 and an upper frame part 24. The frame 14 forms a housing for an endless, circumferential band knife 26. In the present case, the band knife 26 is spanned to form a rectangular plane (x-z plane) via four deflection rollers 28a, 28b, 28c, 28d, wherein the deflection rollers 28a, 28b, 28c, 28d are in each case located in the corners of the rectangular plane. The band knife 26 rotates around the four deflection rollers 28a, 28b, 28c, 28d in the direction of rotation (along the arrow U here). The deflection rollers 28a, 28b, 28c, 28d serve the purpose of guiding the band knife 26.

[0076] The four deflection rollers 28a, 28b, 28c, 28d are arranged within the frame 14 and also a majority of the circumferential band knife 26. A tensioning roller 28a is the drive roller, which serves the purpose of driving the band knife 26 in the direction of rotation U.

[0077] In order to ensure a sufficient band tension of the band knife 26, the deflection roller 28c is a tensioning roller, which is connected to a pneumatic cylinder 30. Together with a tensioning carriage 32, the tensioning roller 28c is supported on the frame 14 so as to be capable of being shifted in the transverse direction (x direction).

[0078] A cutting region 34 is formed between the first deflection roller 28a and the second deflection roller 28b. A cutting section 36 of the band knife 26, which runs outside of the frame 14 and in which the band knife 26 extends in the transverse direction (x direction) of the cutting machine 10, is located in the cutting region 34. The workpiece 20 is supplied in the cutting region 34 and is cut here by the band knife 26. A center holder 38, which extends perpendicularly downwards (in the z direction) from the upper frame element 24 of the frame 14, is arranged centrally of the cutting region 34. The center holder 38 serves the purpose of guiding and stabilizing the cutting section 36 of the band knife 26 in the cutting region 34.

[0079] The cutting machine 10 at hand is a horizontal cutting machine, wherein the frame 14, together with band knife 26, can be displaced in the vertical direction (z direction) and 2D contours are cut into the workpiece 20 in the y-z plane.

[0080] In order to also be able to cut oblique contours, the band knife 26 can be twisted in the cutting section 36. For this purpose, the band knife 26 can be twisted via twisting units 40a, 40b. The twisting units 40a, 40b are in each case arranged laterally of the cutting region 34 and twist the band knife 26 about the longitudinal axis. A twisting unit can additionally be arranged (not shown) on the center holder 38. The twisting units 40a, 40b are in each case synchronized and simultaneously twist the band knife 26 about the same angle of twist. The torsion of the band knife 26 takes place between the lateral twisting units 40a, 40b and the deflection rollers 28a, 28b adjacent thereto. The band knife 26 runs in a non-twisted manner or so as not to be twisted, respectively, between the twisting units 40a, 40b in the cutting region 26.

[0081] To check the state of the band knife 26, the cutting machine 10 has, according to the present exemplary embodiment, several sensors 42a, 42b, 42c, 42d, 42e, 42f, which in each case detect the measuring values representing the band damage to the band knife 26.

[0082] Here, a first sensor 42a is a distance sensor for measuring the displacement of the tensioning roller 28c. This is shown in detail in FIG. 2. Here, the tensioning roller 28c itself can be displaced in the x direction by means of the pneumatic cylinder 30. A defined tensioning force is thereby exerted on the circumferential band knife 26 in each case. The farther the tensioning roller 28c is deflected outwards-thus to the left in the x direction in FIG. 2the stronger the band knife 26 has already lengthened. The shifting of the tensioning roller 28c is measured by means of the distance sensor 42a, which is arranged on the frame 14 in a stationary manner. Concretely, the distance d between the tensioning carriage 32, which can be displaced by means of the tensioning roller 28c, and the distance sensor 42a is measured.

[0083] A second sensor 42b is a temperature sensor for measuring the ambient temperature in the vicinity of the band knife 26 (see FIG. 3). The temperature of the band knife 26 is indirectly determined by means of the temperature sensor 42b. In the shown embodiment, the temperature sensor 42b is arranged in the surrounding area of the drive roller 28a.

[0084] A third sensor 42c is likewise a temperature sensor, which directly measures the temperature of the band knife 26 (see FIG. 3). This is a laser pyrometer, wherein a laser beam is directed at the band knife 26. In the shown embodiment, the third sensor 42c is arranged directly adjacent to the drive roller 28a.

[0085] A fourth sensor 42d and a fifth sensor 42e are acceleration sensors. The fourth sensor 42d is an acceleration sensor, which is arranged on the tensioning carriage 32 of the tensioning roller 28c, which can be shifted together with the tensioning roller 28c (see FIG. 2). The band knife 26 is in close contact with the tensioning roller 28c and transmits vibrations to the tensioning roller 28c and the tensioning carriage 32 thereof. These vibrations are detected by the acceleration sensor 42d. The acceleration sensor 42d measures the acceleration of the tensioning carriage 32 in all three spatial directions.

[0086] The fifth sensor 42e is arranged on the center holder 38 and measures the vibrations or accelerations, respectively, which are transmitted to the center holder 38 by means of the band knife 26. The acceleration sensor 42e likewise measures the acceleration in all three spatial directions.

[0087] A sixth sensor is a force sensor 42f, which directly or indirectly measures the acting force between the pneumatic cylinder 30 and the tensioning carriage 32 of the tensioning roller 28c in the direction of the pneumatic cylinder 30. In addition to the currently acting tensioning force, said sensor can also detect small changes of the force, which change quickly over time, due to transmitted vibrations.

[0088] The measuring values, which are determined by the respective sensors 42a, 42b, 42c, 42d, 42e, 42f and which represent the band damage, are transferred to an evaluation unit 44. In the shown embodiment, the communication between the sensors 42a, 42b, 42c, 42d, 42e, 42f and the evaluation unit 44 takes place wirelessly. The information generated by the evaluation unit 44, such as, for example, a forecast remaining service life of the band knife 26, is then displayed on an output unit 46.

[0089] A method for checking the damage state of a band knife 26 is further illustrated in FIG. 5.

[0090] The method is started with step S1.

[0091] After starting the method in step S1, it is checked in step S2 if the remaining service life of the band knife 26 is greater than the duration of the started cutting program.

[0092] If it is determined in step S2 that the determined remaining service life of the band knife 26 is less than the duration of the cutting program (n) to be started, the cutting program is initially not started and a warning is output in step S4. The method then ends in step S4. Instead of allowing the method to end, it can also be provided that the cutting parameters are adapted automatically or manually, so that the band knife 26 is conserved and the cutting program can still be executed or an operator clicks ignore.

[0093] If it is determined in step S2 that the determined remaining service life of the band knife 26 is greater than the duration of the cutting program (y=yes), the cutting program is started in step S5.

[0094] For the duration of the cutting program, a measuring value representing the band damage to the band knife 26 is detected by at least one sensor 42a, 42b, 42c, 42d, 42e, 42f in step S6 and is transferred to the evaluation unit 44 in step S7.

[0095] In step S8, the evaluation unit 44 generates information with respect to the damage state of the band knife 26 from the measuring value or the several measuring values, respectively. The information is generated by means of a trained machine-learning algorithm on the basis of the supplied measuring values. Here, the information is a remaining service life of the band knife 26.

[0096] In step S9, the remaining service life is transmitted to the output unit 46 and is output on the output unit 46.

[0097] After step S9, it is additionally checked in step S10 whether the current stress of the band knife 26 is particularly strong, if yes (y), a warning it output in step S11 and the parameters of the cutting process are additionally adapted in step S12. The method is subsequently continued with step S6.

[0098] If it is determined in step S10 that the stress of the band knife 26 is not greater than planned (n), the method is continued with step S6.

LIST OF REFERENCE NUMERALS

[0099] 10 device for knife cutting or sawing (cutting machine) [0100] 12 machine stand [0101] 14 frame [0102] 16 table [0103] 18 support surface [0104] 20 workpiece [0105] 22 side part [0106] 24 upper frame part [0107] 26 band knife [0108] 28a deflection roller, tensioning roller [0109] 28b deflection roller [0110] 28c deflection roller, drive roller [0111] 28d deflection roller [0112] 30 pneumatic cylinder [0113] 32 tensioning carriage [0114] 34 cutting region [0115] 36 cutting section [0116] 38 center mount [0117] 40a first twisting unit [0118] 40b second twisting unit [0119] 42a sensor, distance sensor [0120] 42b sensor, temperature sensor [0121] 42c sensor, temperature sensor [0122] 42d sensor, acceleration sensor [0123] 42e sensor, acceleration sensor [0124] 42f sensor, force sensor [0125] 44 evaluation unit [0126] 46 output unit [0127] U direction of rotation [0128] d distance mount tensioning roller to distance sensor