JP2015199190A - Blade tool breakage detection device and cutter machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blade tool breakage detection device capable of detecting breakage of a blade tool for cutter machine with high sensitivity, and the cutter machine comprising the blade tool breakage detection device.SOLUTION: The blade tool breakage detection device detects breakage of a cutter blade 5 for a cold header machine 1. The blade tool breakage detection device comprises: an acceleration sensor 7 for generating an electric signal based on oscillation which is generated during cutting by the cutter blade 5; and a determination tool 10 for determining presence/absence of breakage of the cutter blade 5 based on the electric signal which is generated on the acceleration sensor 7.

Description

  The present invention relates to a blade breakage detection device and a cutting machine, and more particularly to a blade breakage detection device for detecting breakage of a blade for a cutting machine and a cutting machine including the blade breakage detection device. Is.

  Conventionally, as a method for detecting breakage of a blade, a method of monitoring the rotational torque of the blade main spindle has been known (see, for example, Patent Document 1). In addition, as an abnormality detection method for cutting multi-blade tools instead of cutting blade tools, there is a method of performing frequency analysis on a signal from a vibration sensor and detecting an abnormality from the difference in frequency characteristics between normal and abnormal conditions. (For example, refer to Patent Document 2).

Japanese Patent Application Laid-Open No. 7-51999 JP 59-175941 A

  In the method of detecting the breakage of the cutting tool by monitoring the torque as in Patent Document 1 described above, there is a problem that the inspection sensitivity is lowered because the change in torque is small when the moment of inertia of the spindle or the cutting tool is large. In addition, the method of analyzing the frequency of the signal from the vibration sensor as in Patent Document 2 is effective for a cutting blade, while a tool that is subjected to shocking vibrations such as a cutting blade can be used for normal and abnormal times. There is a problem that the difference in frequency characteristics is small and the inspection performance is poor. This is because the frequency component of the shocking vibration applied to the cutting blade is widely and shallowly distributed (for example, during a hammering test with an impulse hammer), and does not have a clear feature in a specific frequency band. is there.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a blade tool breakage detection device and a blade tool breakage detection device capable of detecting breakage of a blade for a cutting machine with higher sensitivity. A cutting machine is provided.

  A blade tool breakage detection device according to the present invention is a blade tool breakage detection device that detects breakage of a blade for a cutting machine. The blade breakage detection apparatus includes a detection unit that generates a signal based on vibration generated when cutting with the blade, and a determination unit that determines whether the blade is damaged based on the signal generated in the detection unit. .

  In the cutting tool breakage detection apparatus according to the present invention, the detection unit can generate a signal based on the vibration generated when cutting with the cutting tool, and the determination unit can determine whether the cutting tool is damaged based on the signal. That is, it is possible to determine whether or not the blade is damaged by comparing the signal based on the vibration generated when the blade is normal and the signal based on the vibration generated when the blade is damaged in the determination unit. Therefore, according to the breakage detection device for a blade according to the present invention, it is possible to detect breakage of the blade for a cutting machine with higher sensitivity.

  In addition, the signal based on the vibration generated at the time of cutting with the cutting tool is an object to be cut, a cutting tool, an object (such as a die, a holder, etc., which will be described later) arranged adjacent to these when cutting the cutting object with the cutting tool, or these And a signal based on vibrations (individual or gas vibrations) occurring in the adjacent space. The signal based on the vibration generated at the time of cutting with the cutting tool is, for example, an electric signal including an acceleration amplitude, an electric signal including a sound amplitude (sound pressure), or the like.

  In the blade breakage detection apparatus, preferably, the detection unit generates the signal that is the amplitude of the characteristic value based on the vibration. The determination unit determines whether or not the cutting tool is damaged based on the amplitude.

  Thereby, the presence or absence of breakage in the blade can be determined by comparing the vibration amplitude when the blade is normal and the vibration amplitude when the blade is broken. As a result, breakage of the cutting tool blade can be detected with higher sensitivity.

  The amplitude of the characteristic value based on the vibration is, for example, an acceleration amplitude or a sound amplitude.

  In the blade breakage detection apparatus, preferably, the determination unit determines that the blade has been damaged when the number of times the amplitude exceeds the upper limit threshold exceeds a predetermined reference number.

  This makes it easier to determine whether or not the cutting tool is damaged. As a result, it is possible to more quickly replace a damaged cutting tool in a cutting machine.

  Preferably, in the blade breakage detection apparatus, the determination unit determines that the blade has been damaged when the number of times the amplitude falls below a lower limit threshold exceeds a predetermined reference number.

  Thereby, it is possible to further easily determine whether or not the cutting tool is damaged. As a result, it is possible to more quickly replace a damaged cutting tool in a cutting machine.

  Preferably, in the cutting tool breakage detection apparatus, the cutting machine includes a die having a hole through which an object to be cut passes and a holder for holding the die. The detection part is attached to the holder.

  Thereby, the vibration generated when the object to be cut is cut by the blade can be detected with high sensitivity by the detection unit. As a result, breakage in the cutting tool can be detected with high sensitivity based on the vibration.

  In the blade breakage detection apparatus, the detection unit is preferably an acceleration sensor. Thereby, breakage of the cutting tool can be detected with high sensitivity due to a change in acceleration.

  In the blade breakage detection apparatus, preferably, the cutting machine includes a die having a hole through which an object to be cut passes and a holder for holding the die. A detection part exists in the position which opposes each of a blade tool, dice | dies, and a holder at intervals.

  Even if it does in this way, the vibration which generate | occur | produces when a to-be-cut object is cut | disconnected by a blade tool can reach | attain a detection part along the space located between a blade tool, dice | dies, a holder, and these, and a detection part. The vibration can be detected with high sensitivity by the detection unit. As a result, breakage in the cutting tool can be detected with high sensitivity based on the vibration.

  In the blade breakage detection apparatus, the detection unit is preferably an acoustic sensor. Thereby, breakage of the cutting tool can be detected with high sensitivity due to a change in sound.

  In the blade breakage detection apparatus, the detection unit is preferably provided so that the distance from the blade can be changed.

  Thereby, the magnitude | size (sound pressure level) detected by a detection part can be adjusted by changing the distance between a detection part and a cutting tool. The amplitude of vibration generated when the workpiece is cut by the cutting tool increases as the width along the cutting direction of the workpiece increases. For this reason, when a workpiece having a different width is cut using a detection unit having a fixed distance from the cutting tool, the amplitude of vibration that occurs when the workpiece is cut is within the detection range of the detection unit. It may not fit and detection may be difficult. On the other hand, if the detection unit is provided so that the distance from the cutting tool can be changed, the amplitude of vibration generated by the cutting can be detected by the detection unit even when the workpiece having the different width is cut. Can be within the range. Therefore, the breakage detection apparatus provided with such a detection unit can detect with high sensitivity the vibration that occurs when cutting regardless of the width of the object to be cut.

  Preferably, the blade breakage detection apparatus further includes a band filter that extracts only a signal based on the vibration having a predetermined frequency from the signals generated in the detection unit and transmits the signal to the determination unit.

  Thereby, it is possible to extract only the signal based on the vibration in the frequency band in which the difference in vibration between when the blade is normal and when the blade is damaged is large. As a result, breakage of the cutting tool can be detected with higher sensitivity.

  The cutting machine according to the present invention includes the blade tool breakage detection device according to the present invention, which can detect the breakage of the cutting tool blade with higher sensitivity. Therefore, according to the cutting machine according to the present invention, a damaged blade can be replaced more quickly.

  As is apparent from the above description, according to the blade breakage detecting device and the cutting machine according to the present invention, the blade breakage detecting device capable of detecting breakage of the cutting tool for the cutting machine with higher sensitivity, and A cutting machine provided with the breakage detection device of the blade can be provided.

1 is a schematic cross-sectional view showing a structure of a cutting machine according to Embodiment 1. FIG. It is a schematic side view which shows the structure of the cutting machine which concerns on Embodiment 1. FIG. It is a figure which shows schematically the structure of the damage detection apparatus which concerns on Embodiment 1. FIG. 5 is a graph showing the amplitude of a pulse waveform when the cutting blade is normal when the cutting blade is normal in the cutting machine according to Embodiment 1; 4 is a graph showing the amplitude of a pulse waveform when a cutting blade is damaged in the cutting machine according to Embodiment 1. 6 is a graph showing the result of frequency analysis when the cutting blade is normal in the cutting machine according to Embodiment 1; 5 is a graph showing the result of frequency analysis when the cutting blade is broken in the cutting machine according to Embodiment 1. It is a figure which shows schematically the structure of the damage detection apparatus which concerns on Embodiment 2. FIG. It is a graph which shows the amplitude of a pulse waveform in case the cutting blade is normal in the cutting machine (it does not have a band filter) concerning Embodiment 2. It is a graph which shows the amplitude of the pulse waveform when the cutting blade is damaged in the cutting machine (no band filter) according to the second embodiment. It is a graph which shows the amplitude of a pulse waveform in case the cutting blade is normal in the cutting machine (equipped with a band pass filter) concerning Embodiment 2. It is a graph which shows the amplitude of the pulse waveform when the cutting blade is damaged in the cutting machine (equipped with a band filter) according to the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

(Embodiment 1)
First, the configuration of a cold header machine as a cutting machine according to an embodiment of the present invention will be described. Referring to FIGS. 1 and 2, a cold header machine 1 is for cutting a wire 11 that is an object to be cut into a predetermined length, and includes a holder 2, a die 3, a stopper 4, and a cutting blade 5 (cutting tool). And has mainly. Referring to FIG. 3, the cold header machine 1 detects a vibration due to an impact generated when the wire 11 is cut by the cutting blade 5 and determines whether or not the cutting blade 5 is damaged (acceleration sensor 7). An amplifier 8, a bandpass filter 9 and a decision unit 10). This breakage detection device is a blade breakage detection device according to the present embodiment, and its configuration will be described in detail later.

  Referring to FIG. 1, a die 3 is attached in a holder 2 and has a through hole (hole) through which a wire 11 passes in the center. The holder 2 holds the die 3 inside, and similarly has a through hole in the center for allowing the wire 11 to pass through. The die 3 and the holder 2 are arranged so that the through holes provided in the central portion communicate with each other. Thereby, the wire 11 sent to the die 3 is discharged from the outlet 3a and hits the stopper 4 to stop. As shown in FIG. 1, the stopper 4 is disposed at a distance from the die 3 on the outlet 3a side.

  The cutting blade 5 is provided in the vicinity of the outlet 3a. Referring to FIG. 2, the cutting blade 5 is connected to a rotating member 6 and is rotatable as indicated by an arrow in FIG. Thereby, the wire 11 discharged from the outlet 3 a of the die 3 and stopped by hitting the stopper 4 can be cut to a predetermined length by the cutting blade 5. Thus, when cutting the wire 11 with the cutting blade 5, vibration due to impact occurs, and the vibration varies depending on the state (normal or damaged) of the cutting blade 5.

  Next, the configuration of the blade breakage detection apparatus according to the present embodiment will be described. Referring to FIG. 3, the breakage detection apparatus according to Embodiment 1 is an apparatus for detecting breakage of a cutting tool for a cutting machine such as cold header machine 1, and includes an acceleration sensor 7 (detection unit), It mainly includes an amplifier 8, a band filter 9, and a determiner 10 (determination unit).

  The acceleration sensor 7 is attached to the upper surface of the holder 2. The acceleration sensor 7 converts vibration generated when the wire 11 is cut by the cutting blade 5 into an electric signal. This electric signal includes the amplitude of acceleration (the amplitude of the characteristic value) based on the vibration generated when the wire 11 is cut by the cutting blade 5. The amplifier 8 is connected to the acceleration sensor 7 and amplifies an electric signal generated in the acceleration sensor 7.

  The band filter 9 is connected to the amplifier 8. The band filter 9 extracts only the electric signal generated by the vibration in the predetermined frequency band (pass band) from the electric signals generated in the acceleration sensor 7 and transmits the extracted electric signal to the determiner 10.

  The pass band of the band filter 9 can be determined as follows. That is, the difference in frequency distribution between when the cutting blade 5 is normal and when it is damaged is confirmed in advance using an FFT (Fast Fourier Transform) analyzer or the like, and a frequency band having a large amplitude difference between normal and damaged is determined. It can be determined as the pass band. The pass band determined as described above is, for example, not less than 1000 Hz and not more than 2000 Hz.

  The determiner 10 is connected to the band filter 9. The determiner 10 is for determining whether or not the cutting blade 5 is damaged based on the electrical signal generated in the acceleration sensor 7. More specifically, the determiner 10 determines the presence or absence of breakage in the cutting blade 5 based on the magnitude of the acceleration amplitude based on the vibration generated when the cutting blade 5 cuts.

  Next, with reference to FIG. 4 and FIG. 5, the determination system about the presence or absence of the damage of the cutting blade 5 in the determination device 10 is demonstrated in detail. 4 and 5 are graphs showing the amplitude of acceleration of the pulse waveform on the time axis after passing through the band-pass filter 9. 4 and 5, the horizontal axis indicates time, and the vertical axis indicates the amplitude of acceleration (absolute value). FIG. 4 is a graph when both of the two cutting blades are normal, and FIG. 5 is a graph when one of the two cutting blades is broken.

Referring to FIG. 4, when both cutting blades are normal, the amplitudes of the vibration pulses are all 300 m / s ² (upper threshold) or less. On the other hand, referring to FIG. 5, when one cutting blade is broken, a pulse having an amplitude of 300 m / s ² or less (corresponding to a normal cutting blade) and a pulse having an amplitude exceeding 300 m / s ² (breakage) Equivalent to the cutting blade). The determination device 10 can determine that the cutting blade 5 has been damaged when the number of times that the amplitude exceeds 300 m / s ² (upper limit threshold) exceeds a predetermined reference number. The upper limit threshold and the reference number are not particularly limited, and can be appropriately adjusted so that breakage of the cutting blade 5 can be detected with high sensitivity. Depending on the state of damage of the cutting blade 5, the amplitude at the time of breakage may be smaller than the amplitude at the time of normal operation. In this case, the determiner 10 may determine that the cutting blade 5 has been damaged when the number of times the amplitude exceeds the lower limit threshold exceeds a predetermined reference number.

  As described above, in the blade tool breakage detection apparatus according to the first embodiment, the acceleration sensor 7 generates an electrical signal based on the vibration generated when the cutting blade 5 cuts, and the determiner 10 based on the electrical signal. The presence or absence of breakage in the cutting blade 5 can be determined. In other words, the determination device 10 compares the electrical signal based on the vibration generated when the cutting blade 5 is normal and the electrical signal based on the vibration generated when the cutting blade 5 is damaged, thereby damaging the cutting blade 5. The presence or absence of can be determined. Therefore, according to the breakage detection device for a cutting tool according to the present embodiment, breakage in the cutting blade 5 of the cold header machine 1 can be detected with higher sensitivity.

  In the blade breakage detecting apparatus according to the present embodiment, the acceleration sensor 7 generates an electrical signal that is an amplitude of acceleration based on the vibration generated when the cutting blade 5 cuts. After passing, the presence or absence of breakage of the cutting blade 5 is determined based on the magnitude of the amplitude. Thereby, the presence or absence of breakage of the cutting blade 5 can be determined by comparing the vibration amplitude when the cutting blade 5 is normal and the vibration amplitude when the cutting blade 5 is damaged. As a result, breakage in the cutting blade 5 of the cold header machine 1 can be detected with higher sensitivity.

6 and 7 are graphs showing the results of frequency analysis of the electrical signal after passing through the amplifier 8. 6 and 7, the horizontal axis indicates the frequency (Hz), and the vertical axis indicates the acceleration (m / s ² ). FIG. 6 is a graph when both of the two cutting blades are normal, and FIG. 7 is a graph when one of the two cutting blades is broken. Comparing the graphs of FIG. 6 and FIG. 7, when one cutting blade is damaged, an increase in acceleration is recognized in the frequency band of 1500 to 2000 Hz as compared with the normal time, but the difference in pulse amplitude of the time axis waveform (FIG. 4 and FIG. 5), the difference is smaller. Further, in the frequency analysis, when one cutting blade is damaged as the number of cutting blades increases, the influence of other normal damaged blades increases, so that the inspection performance deteriorates. Therefore, by comparing the pulse amplitude after passing through the band-pass filter 9 as in the present embodiment, the breakage of the cutting blade 5 can be detected with higher sensitivity than the breakage detection by the frequency analysis.

(Embodiment 2)
Next, with reference to FIG. 8, the structure of the cold header machine 1 as a cutting machine which concerns on one embodiment of this invention, and a damage detection apparatus is demonstrated. The breakage detection apparatus according to the second embodiment basically has the same configuration as the breakage detection apparatus according to the first embodiment, but includes an acoustic sensor 12 instead of the acceleration sensor 7 (see FIG. 1). Different. That is, the damage detection apparatus according to the second embodiment mainly includes the acoustic sensor 12 (detection unit), the amplifier 8, the band filter 9, and the determination unit 10 (determination unit).

  The cold header machine 1 according to the second embodiment has basically the same configuration as the cold header machine 1 according to the first embodiment, but differs in that it includes the damage detection apparatus according to the second embodiment.

  The acoustic sensor 12 is provided at a position facing the cutting blade 5, the holder 2, and the die 3 with a space therebetween. The acoustic sensor 12 converts vibration (sound) generated when the wire 11 is cut by the cutting blade 5 into an electrical signal. This electrical signal includes the amplitude (sound pressure) of the characteristic value based on the vibration (sound) generated when the wire 11 is cut by the cutting blade 5. The amplifier 8 is connected to the acoustic sensor 12 and amplifies an electrical signal generated in the acoustic sensor 12.

  The band filter 9 is connected to the amplifier 8. The band filter 9 extracts only the electric signal generated by the vibration in the predetermined frequency band (pass band) from the electric signals generated in the acoustic sensor 12, and transmits the extracted electric signal to the determiner 10.

  The pass band of the band filter 9 can be determined as follows. That is, a difference in frequency distribution between when the cutting blade 5 is normal and when it is damaged is confirmed in advance using an FFT analyzer or the like, and a frequency band having a large amplitude difference between normal and damaged is determined as the pass band. can do. The pass band determined as described above is, for example, 200 Hz to 1 kHz.

  The determiner 10 is connected to the band filter 9. The determiner 10 is for determining whether or not the cutting blade 5 is damaged based on an electrical signal generated in the acoustic sensor 12. More specifically, the determiner 10 determines whether or not the cutting blade 5 is damaged based on the amplitude of sound based on the vibration generated when the cutting blade 5 cuts.

  Next, with reference to FIG. 9 and FIG. 10, the determination method about the presence or absence of the damage of the cutting blade 5 in the determination device 10 is demonstrated in detail. 9 and 10 are graphs showing the amplitude of the acoustic pulse (vibration pulse) on the time axis after passing through the amplifier 8. 9 and 10, the horizontal axis represents time (seconds), and the vertical axis represents the amplitude (Pa) of the acoustic pulse. FIG. 9 is a graph when the cutting blade is normal, and FIG. 10 is a graph when the cutting blade is damaged.

  9 and 10, when the cutting blade is normal, the amplitude of the acoustic pulse is smaller than the amplitude of the acoustic pulse when the cutting blade is damaged. In the determiner 10, an upper limit threshold of an amplitude that is larger than the amplitude of the acoustic pulse when the cutting blade is normal and is equal to or smaller than the amplitude of the acoustic pulse when the cutting blade is damaged is provided in advance, and the measured amplitude is It can be determined that the cutting blade 5 has been damaged when the number of times the upper limit threshold has been exceeded exceeds a predetermined reference number. The upper limit threshold and the reference number are not particularly limited, and can be appropriately adjusted so that breakage of the cutting blade 5 can be detected with high sensitivity.

  Further, depending on the damaged state of the cutting blade 5, the amplitude at the time of breakage may be smaller than the amplitude at the normal time. In this case, in the determination device 10, a lower limit threshold that is equal to or larger than the amplitude of the acoustic pulse when the cutting blade is broken and less than the amplitude of the acoustic pulse when the cutting blade is normal is set in advance, and the measured amplitude is It is also possible to determine that the cutting blade 5 has been damaged when the number of times that the lower limit threshold is exceeded exceeds a predetermined reference number.

  As described above, in the blade tool breakage detection apparatus according to the second embodiment, the acoustic sensor 12 generates an electrical signal based on the vibration generated when the cutting blade 5 cuts, and the determiner 10 determines the electrical signal based on the electrical signal. The presence or absence of breakage in the cutting blade 5 can be determined. In other words, the determination device 10 compares the electrical signal based on the sound generated when the cutting blade 5 is normal and the electrical signal based on the sound generated when the cutting blade 5 is damaged, whereby the damage in the cutting blade 5 is detected. The presence or absence of can be determined. Therefore, according to the cutting tool breakage detection apparatus according to the second embodiment, breakage in the cutting blade 5 of the cold header machine 1 can be detected with higher sensitivity by changing sound.

  The acoustic sensor 12 is located at a position facing the cutting blade 5, the die 3, and the holder 2 with a space therebetween. Even if it does in this way, the vibration which generate | occur | produces when the wire 11 is cut | disconnected by the cutting blade 5 propagates through the space located between the cutting blade 5, the die | dye 3, the holder 2, and these and the acoustic sensor 12, and is sounded. The sensor 12 can be reached. The vibration can be detected with high sensitivity by the acoustic sensor 12. As a result, breakage in the cutting blade 5 can be detected with high sensitivity based on the vibration.

  It is preferable that the acoustic sensor 12 is provided so that the distance from the cutting blade 5 can be changed. In this way, the sound pressure level of the sound detected by the acoustic sensor 12 can be adjusted by changing the distance between the acoustic sensor 12 and the cutting blade 5. The amplitude of the sound generated when the wire 11 is cut by the cutting blade 5 increases as the wire diameter (width along the cutting direction) of the wire 11 increases. Therefore, when cutting the wire 11 having a different wire diameter using the acoustic sensor 12 having a fixed distance from the cutting blade 5, the amplitude of the sound generated when the wire is cut is In some cases, it may be difficult to detect because it is not within the detection range. On the other hand, if the acoustic sensor 12 is provided so that the distance from the cutting blade 5 can be changed, the amplitude of the sound generated by the cutting is also detected when the wire 11 having a different width is cut. It is possible to fit within 12 detection ranges. Therefore, the breakage detection apparatus provided with such an acoustic sensor 12 can detect with high sensitivity the sound generated when the wire 11 is cut without depending on the wire diameter.

  In the blade breakage detecting apparatus according to the present embodiment, the acoustic sensor 12 generates a signal based on the vibration generated when the cutting blade 5 cuts, and the determiner 10 increases the amplitude after passing through the band filter 9. The presence or absence of breakage of the cutting blade 5 may be determined based on the height. Thereby, the presence or absence of breakage of the cutting blade 5 can be determined by comparing the sound amplitude when the cutting blade 5 is normal and the sound amplitude when the cutting blade 5 is damaged. As a result, breakage in the cutting blade 5 of the cold header machine 1 can be detected with higher sensitivity.

  FIGS. 11 and 12 are graphs showing the results of frequency analysis of the electrical signal after passing through the bandpass filter 9 in the blade breakage detection apparatus according to the second embodiment. 11 and 12, the horizontal axis indicates time (seconds), and the vertical axis indicates sound amplitude (Pa). FIG. 11 is a graph when the cutting blade is normal, and FIG. 12 is a graph when the cutting blade is damaged. Comparing the graphs of FIG. 11 and FIG. 12, when the cutting blade is broken, a pulsed acoustic signal is seen, but in normal times, a pulsed acoustic signal is hardly seen, and the difference in acoustic signal is It has become prominent. Therefore, by comparing the pulse amplitude after passing through the band filter 9 as in the second embodiment, the breakage of the cutting blade 5 can be detected with higher sensitivity than when the band filter 9 is not used. .

  The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The blade breakage detection device and the cutting machine of the present invention can be applied particularly advantageously in a blade tool breakage detection device that detects breakage of a blade for a cutting machine and a cutting machine that includes the blade breakage detection device.

  DESCRIPTION OF SYMBOLS 1 Cold header machine, 2 Holder, 3 Dies, 3a exit, 4 Stopper, 5 Cutting blade, 6 Rotating member, 7 Acceleration sensor, 8 Amplifier, 9 Band filter, 10 Judgment device, 11 Wire rod, 12 Acoustic sensor

Claims (11)

A tool for detecting breakage of a blade for detecting breakage of the blade for a cutting machine,
A detection unit that generates a signal based on vibration generated when cutting with the cutting tool;
A blade breakage detection device comprising: a determination unit that determines whether or not the blade is damaged based on the signal generated in the detection unit. The detection unit generates the signal that is an amplitude of a characteristic value based on the vibration,
2. The blade breakage detection device according to claim 1, wherein the determination unit determines whether or not the blade is damaged based on the amplitude.   The blade breakage detection device according to claim 2, wherein the determination unit determines that the blade has been damaged when the number of times the amplitude exceeds the upper limit threshold exceeds a predetermined reference number.   The blade breakage detection device according to claim 2, wherein the determination unit determines that the blade has been damaged when the number of times the amplitude exceeds a lower limit threshold exceeds a predetermined reference number. The cutting machine includes a die having a hole through which an object to be cut passes, and a holder for holding the die.
The blade detection device according to claim 1, wherein the detection unit is attached to the holder.   The blade breakage detection device according to claim 1, wherein the detection unit is an acceleration sensor. The cutting machine includes a die having a hole through which an object to be cut passes, and a holder for holding the die.
5. The blade breakage detection device according to claim 1, wherein the detection unit is located at a position facing the blade tool, the die, and the holder with a space therebetween.   The blade breakage detection device according to claim 7, wherein the detection unit is an acoustic sensor.   The blade detection device according to claim 8, wherein the detection unit is provided to be able to change a distance from the blade.   10. The bandpass filter according to claim 1, further comprising: a bandpass filter that extracts only a signal based on the vibration having a predetermined frequency from the signals generated in the detection unit and transmits the signal to the determination unit. Blade breakage detection device.   A cutting machine comprising the blade breakage detection device according to any one of claims 1 to 10.

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