JP2018054587A - Work machine vibration monitoring method and system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration monitoring method capable of accurately and efficiently determining whether the machining state is acceptable or not using a simple configuration and step.SOLUTION: The vibration monitoring method includes the steps of: displaying the number of times TPF (tool passing frequency) peak, which is a peak acceleration at tool passing frequency, has exceeded a TPF threshold on an indication column 56a of a display part 56 of integrated threshold exceeding times; displaying the number of times the harmonic TPF peak has exceeded the harmonic TPF threshold at a harmonic frequency on indication columns 56b to 56d of the display part 56 of integrated threshold exceeding times; and comparing the number of times exceeding the TPF threshold with the number of times exceeding the harmonic TPF threshold and displaying the result on a change display part 58.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vibration monitoring method and system for a work machine for monitoring a vibration state of the processing tool when the processing tool or workpiece is rotated to process the workpiece through the processing tool.

  In general, various machine tools are used to process a workpiece through a processing tool. For example, in the boring process, a boring tool provided with a boring cutter (cutting edge) is attached to a rotating spindle (spindle) of a machine tool, and the boring tool is sequentially fed along a pilot hole while rotating at a high speed. A highly accurate hole is processed at a predetermined position with the cutting edge diameter.

  In this type of work machine, it is necessary to determine whether the machining state is good or not in order to perform high-precision machining. Conventionally, whether the machining state is good or bad is determined by whether it is a machining sound, that is, a good cutting sound. Further, the sound and vibration are the same source, and the quality of the machining state can be determined by detecting the characteristics of the machining vibration.

  For example, the machining state monitoring method disclosed in Patent Document 1 includes a normal state determination step for determining whether or not a workpiece is in a normal state, and a chatter vibration for determining whether or not chatter vibration is occurring. A judgment step, a judgment period judgment step for judging that it is a sign period in which the chatter vibration is shifted from the normal condition when it is judged that the chatter vibration is not generated and not in the normal state, and the sign period When it is determined that the machining state is, the machining state in the precursor period is monitored, and the precursor period monitoring step for displaying the machining state in the precursor period on the screen is provided. For this reason, by obtaining characteristic information from the machining state in the predictive period, it is possible to respond quickly and effectively before chatter vibration occurs.

  Japanese Patent Laid-Open No. 2006-083759

  The present invention has been made in connection with the above technical idea, and provides a vibration monitoring method and system for a work machine that can accurately and efficiently determine the quality of a machining state with a simple process and configuration. The purpose is to provide.

  The present invention provides a working machine that sets a vibration at the time of idling of a machine spindle as a threshold value and develops a machining vibration detected at the time of machining of the machine spindle into a frequency spectrum composed of frequency and acceleration by Fourier series expansion. The present invention relates to a vibration monitoring method and system.

  In this vibration monitoring method, a TPF peak, which is a peak acceleration at a tool passing frequency calculated from the number of rotations and the number of blades of a machining tool, is a TPF that is a peak threshold value of the tool passing frequency preset in a frequency spectrum. A step of displaying the number of times that the TPF peak has exceeded the TPF threshold on the TPF threshold value exceeding display unit, and a peak at a harmonic frequency that is an integral multiple of the tool passing frequency. A harmonic TPF peak that is acceleration is compared with a harmonic TPF threshold that is a peak threshold of the harmonic frequency preset in the frequency spectrum, and the harmonic TPF peak is compared with the harmonic TPF threshold. The number of times the value is exceeded is displayed on the harmonic TPF threshold value excess integration display section, and the number of times the TPF threshold value is exceeded and the number of times the harmonic TPF threshold value is exceeded. And a, and a step of displaying the change display unit by comparing and.

  Further, in this vibration monitoring method, the harmonic TPF threshold value exceeding integrated display unit has at least the first harmonic TPF peak at the harmonic frequency twice the tool passing frequency exceeds the harmonic TPF threshold value. The first harmonic TPF threshold value exceeding integrated display section for displaying the number of times, and the number of times that the second harmonic TPF peak at the harmonic frequency three times the tool passing frequency exceeds the harmonic TPF threshold value. A second harmonic TPF threshold value exceeding integrated display unit to be displayed, wherein the change display unit includes the TPF threshold value exceeding number, at least the first harmonic TPF threshold value exceeding number and the second harmonic value. It is preferable to compare and display the sum of the number of times the wave TPF threshold is exceeded.

  Further, this vibration monitoring system is configured such that the TPF peak, which is the peak acceleration at the tool passing frequency calculated from the number of rotations of the machining tool and the number of blades, is a peak threshold value of the tool passing frequency preset in the frequency spectrum. A TPF threshold value exceeding display section for comparing with a TPF threshold value and displaying the number of times the TPF peak exceeds the TPF threshold value; and peak acceleration at a harmonic frequency that is an integral multiple of the tool passing frequency. Is compared with a harmonic TPF threshold that is a peak threshold of the harmonic frequency preset in the frequency spectrum, and the harmonic TPF peak is compared with the harmonic TPF threshold. The harmonic TPF threshold value overrun display section that displays the number of times the frequency exceeds the TPF threshold value, and the harmonic TPF threshold value exceeded number And a, a change display unit for displaying compared to.

  Furthermore, in this vibration monitoring system, the harmonic TPF threshold value exceeding integrated display unit has at least the first harmonic TPF peak at the harmonic frequency twice the tool passing frequency exceeding the harmonic TPF threshold value. 1st harmonic TPF threshold value exceeding integrated display section for displaying the number of times the second harmonic TPF peak has exceeded the harmonic TPF threshold value at a harmonic frequency three times the tool passing frequency. A second harmonic TPF threshold value exceeding integration display unit, and the change display unit displays the TPF threshold value exceeding number, the at least first harmonic TPF threshold value exceeding number, and the second harmonic value. It is preferable to compare and display the sum of the number of times the wave TPF threshold is exceeded.

  In the vibration monitoring method and system according to the present invention, when a workpiece is machined through a machining tool, the correlation between the number of peak occurrences at the tool passing frequency (TPF) and the number of peak occurrences at the harmonic frequency is observed. be able to. In a good machining state, the number of peak occurrences at the tool passing frequency becomes relatively significant, while in a poor machining state, the number of peak occurrences at the harmonic frequency increases with the tool passing frequency. For this reason, the quality determination of the machining state can be performed with high accuracy and efficiency from the change in the relationship between the two.

  1 is a schematic explanatory diagram of a work machine to which a work machine vibration monitoring system according to an embodiment of the present invention is applied.   It is explanatory drawing of the controller which comprises the said vibration monitoring system.   FIG. 3 is an explanatory diagram of a configuration of a display unit constituting the vibration monitoring system.   It is explanatory drawing of the favorable process vibration displayed on the frequency spectrum display part which comprises the said display unit.   It is explanatory drawing of the spectrum obtained by carrying out the Fourier transform of the processing vibration shown in FIG.   It is explanatory drawing of the defective process vibration displayed on the said frequency spectrum display part.   It is explanatory drawing of the spectrum obtained by carrying out the Fourier transform of the processing vibration shown in FIG.   It is explanatory drawing which displays the time-dependent change of the accumulation comparison value in a favorable processing state.   It is explanatory drawing which displays the time-dependent change of the cumulative comparison value in a bad processing state.

  As shown in FIG. 1, a working machine machining state monitoring system (vibration monitoring system) 10 according to an embodiment of the present invention is applied to a machine tool 12. The machine tool 12 is applied to a work machine of a system in which an acceleration sensor 26, a microphone 28, and a controller 30 described later are functionally integrated.

  The machine tool 12 includes a spindle (main shaft) 18 that is rotatably provided in a housing 14 via a bearing 16, and a tool holder (processing tool) 20 that is detachably attached to the spindle 18. A cutter 22 is attached to the tip of the tool holder 20. A work W is placed on the work table 24.

  The machining state monitoring system 10 includes at least an acceleration sensor 26 attached to a side portion of the housing 14 or a microphone 28 that obtains vibration sound using sound waves in order to detect vibration generated when machining by the cutter 22 is started. Provide one side. The acceleration sensor 26 and / or the microphone 28 are connected to a controller 30, and the controller 30 is connected to a machine control panel 32. The machine control panel 32 controls the machine tool 12 and is connected to the control operation panel 34.

  As shown in FIG. 2, the controller 30 includes an arithmetic unit (arithmetic mechanism) 38 that amplifies and takes in mechanical vibration (machining vibration) detected by the acceleration sensor 26 and / or the microphone 28 by an amplifier and filter circuit 36. Prepare.

  An input setting unit (input setting unit) 40 for inputting the number of rotations of the spindle 18, the number of blades of the cutter 22, the natural frequency, and the like is connected to the arithmetic unit 38. The input setting unit 40 can set a threshold for monitoring and identification determination, a signal processing procedure when vibration exceeding the threshold occurs, and the like. The input setting unit 40 is provided with a repeat counter (circuit) 42 as necessary.

  The processing unit 38 is connected to the machining state determination unit 44 and an input / output unit 46 for outputting a signal subjected to calculation determination processing described later. The calculation unit 38 is connected to a display unit 48 that displays calculation results and detection results on the screen. The updated data is sent from the arithmetic unit 38 to the machining state determination unit 44, for example, every second.

  As shown in FIG. 3, the display unit 48 includes a frequency spectrum display unit 52, a threshold value exceeding display unit 56, and a change display unit 58. The frequency spectrum display unit 52 can set a threshold value for each band or for each specified frequency. When vibration exceeding the set threshold value occurs, it is counted as exceeding the threshold value, and the count number is the threshold value. Accumulated and displayed on the overrun display 56. The threshold value exceeding integration display unit 56 includes a first display field (TPF threshold value exceeding integration value) which is a plurality of type display windows linked to preset threshold value exceeding count-up signals for each band or each specified frequency. Display portion) 56a, second display column (harmonic TPF threshold value exceeding integrated display portion) 56b, third display field (harmonic TPF threshold value exceeding integrated display portion) 56c, fourth display column (harmonic TPF threshold display) The threshold value exceeding integration display section) 56d and the fifth display field 56e are set. In the change display section 58, a change over time between the values accumulated in the type display window of the designated threshold value exceeding display section 56 is displayed.

  A vibration monitoring method by the machining state monitoring system 10 configured as described above will be described below.

  As shown in FIG. 1, in the machine tool 12, the spindle 18 to which the tool holder 20 having the cutter 22 attached at the tip is attached is driven to rotate along the pilot hole Wa of the workpiece W. And the tool holder 20 moves relatively to the prepared hole Wa side of the workpiece W. For this reason, the cutter 22 rotates integrally with the tool holder 20, and the inner wall surface of the workpiece W is processed through the cutter 22.

  In the controller 30, before starting machining, the vibration at the time of idle rotation of the spindle 18 is acquired by the acceleration sensor 26 and / or the microphone 28, and this value is used as the vibration amount in the no-load state to be acquired thereafter. The set threshold value. Then, machining is started by the spindle 18, and machining vibration is taken into the arithmetic unit 38 via the amplifier and filter circuit 36. In the arithmetic unit 38, the processing vibration is subjected to arithmetic analysis by Fourier transform (Fourier series expansion). Specifically, the temporal vibration f (t) is

f (t) = Σ (a _j cos2πJt + b _j sin2πJt). Here, a _j is the cosine harmonic component Fourier coefficient of frequency J, and b _j is the sine harmonic component Fourier coefficient of frequency J.

And the Fourier coefficient for frequency J is Fourier series expansion based on a _j = 1 / 2T∫f (t) cos (2πJt) dt and b _j = 1 / 2T∫f (t) sin (2πJt) dt. I do. The integration interval is 0 to T, and this integration interval T is an integral multiple of the period 1 / J. Here, a vibration frequency actually processed, for example, 10 Hz to 10,000 Hz is acquired.

  As shown in FIG. 3, the display unit 48 is provided with a frequency spectrum display unit 52. The frequency spectrum display unit 52 displays a frequency spectrum having the frequency Hz calculated by Fourier analysis as the horizontal axis and the acceleration (vibration intensity) G as the vertical axis.

  Various processing vibrations are displayed on the frequency spectrum display unit 52. For example, FIG. 4 shows machining vibration in a good machining state, while FIG. 6 shows machining vibration in a rough machining state (bad machining state). This will be specifically described below.

  The machining vibration shown in FIG. 4 occurs when an iron-based member is used as the workpiece W and machining is performed at a spindle rotational speed of 3800 RPM by a two-blade cutter 22. FIG. 5 shows the amount of machining vibration shown in FIG. 4 on the time lapse axis (acceleration G on the vertical axis and the number of seconds elapsed from the start of measurement on the horizontal axis). The axis represents frequency Hz and the vertical axis represents acceleration G).

  Here, the tool passing frequency (Tool-Passing-Frequency) at which the cutting edge comes into contact with the workpiece W is obtained from (rotational speed RPM / 60 of the main spindle) × the number of teeth. As shown in FIG. 5, the tool passing frequency is 127 Hz (hereinafter referred to as TPF1). Further, the harmonic frequency twice (integer multiple) of TPF1 is 253 Hz (hereinafter referred to as TPF2), and the harmonic frequency three times (integer multiple) of TPF1 is 380 Hz (hereinafter referred to as TPF3). The harmonic frequency four times (integer multiple) of TPF1 is 507 Hz (hereinafter referred to as TPF4). In addition, you may set the harmonic frequency (TPFn) more than 5 times (integer multiple) of TPF1 as needed.

  In TPF1, TPF2, TPF3, and TPF4, a TPF1 peak, a TPF2 peak, a TPF3 peak, and a TPF4 peak, which are peak accelerations (vibration strengths), are generated, respectively. At that time, the other TPF2 peak, TPF3 peak, and TPF4 peak, which are the harmonic frequencies, are considerably smaller than the size of the TPF1 peak. Further, no large peak acceleration is generated at frequencies other than the TPF1 peak to the TPF4 peak.

  That is, when the frequency spectrum of the machining vibration is observed, only the peak acceleration (TPF1 peak) at the tool passing frequency (TPF1) appears remarkably, and no other large vibration frequency exists. The processing performed in such a state is good, and the processing sound of processing (cutting) shows free cutting sound and a good processed surface is obtained.

  On the other hand, the machining vibration shown in FIG. 6 occurs when an iron-based member is used as the workpiece W and machining is performed at a spindle rotation speed of 3060 RPM by the two-blade cutter 22. FIG. 7 shows the amount of machining vibration shown in FIG. 6 on the time lapse axis (acceleration G on the vertical axis and the number of seconds elapsed from the start of measurement on the horizontal axis). The axis represents frequency Hz and the vertical axis represents acceleration G).

  Here, the tool passing frequency (TPF) is 102 Hz (hereinafter referred to as TPF1). Furthermore, the harmonic frequency twice (integer multiple) of TPF1 is 204 Hz (hereinafter referred to as TPF2), and the harmonic frequency three times (integer multiple) of TPF1 is 306 Hz (hereinafter referred to as TPF3). The harmonic frequency four times (integer multiple) of TPF1 is 408 Hz (hereinafter referred to as TPF4). In addition, you may set the harmonic frequency (TPFn) more than 5 times (integer multiple) of TPF1 as needed.

  Then, the magnitudes of the TPF2, PPF3, and TPF4 peaks, which are the respective peak accelerations of the TPF2, TPF3, and TPF4, are compared with the magnitude of the TPF1 peak that is the peak acceleration of the TPF1. At that time, the magnitudes of the other TPF2 peak, TPF3 peak, and TPF4 peak, which are the harmonic frequencies, are the same as the magnitude of the TPF1 peak. Processing performed in such a state increases processing vibration sound, and the frequency of processing sound includes TPF1, TPF3, and TPF4 sounds as well as low frequencies other than the excited TPF frequency. Is also mixed at the same time. Therefore, it can be heard as a miscellaneous machining sound with a large vibration volume, and it does not feel free-cutting, and the machining surface is also roughened.

  As described above, in the machining state monitoring system 10, in order to determine whether the machining state is good or not, the peak acceleration of the tool passing frequency (TPF) and the peak acceleration of its harmonic frequency in the machining are constantly monitored, and the vibration of the TPF1 peak is observed. The change of the vibration amount of TPF2 to TPFn (n = an integer of 3 or more) is compared with the amount. The details will be described below.

  As shown in FIG. 1, the machining vibration acquired by the acceleration sensor 26 and / or the microphone 28 is sent to the arithmetic unit 38 via the amplifier and filter circuit 36. As shown in FIG. 2, in the arithmetic unit 38, the processing vibration is subjected to arithmetic analysis by Fourier transform (Fourier series expansion), and the value is displayed on the frequency spectrum display unit 52, and the display is performed for a certain period of time. Updated every time (usually every second). On the other hand, in the input setting unit 40, information such as the number of rotations of the spindle 18, the number of blades of the cutter 22, and the natural frequency are input. With this input information, the vibration information of the frequency spectrum can be distinguished into TPF1, TPF2, TPF3,.

  As shown in FIG. 3, when the vibration intensity (peak acceleration) displayed on the frequency spectrum display unit 52 exceeds a threshold set according to the type of the frequency, a count-up value exceeding the threshold is obtained. , And sent to the type display window of the threshold value exceeding display unit 56. Further, before the count-up value detected by the frequency spectrum display unit 52 is integrated and displayed on the type display window of the threshold value excess integration display unit 56 as it is, for example, through a repeat counter 42 provided separately, for example, TPF1 When the count-up signal exceeding the threshold value is issued a plurality of times, the count display signal of the threshold value exceeding integration display section 56 can be integrated and displayed. In this case, the number of repeat counters is set on the setting screen of the input setting unit 40.

  In the threshold value excess integration display unit 56, for example, in the frequency spectrum of vibration generated during machining by the cutter 22, when the vibration of the TPF 1 (TPF 1 peak) exceeds the threshold value set in the frequency spectrum display unit 52, The count-up value exceeding the threshold value is sent to the first display field 56 a of the threshold value exceeding display unit 56. In the first display field 56a, the count-up value of TPF1 is accumulated and displayed. Therefore, the graph displayed in the first display field 56a of the threshold value excess integration display unit 56 is cumulatively added each time a count-up value exceeding the threshold value of TPF1 is sent.

  Similarly, when the vibration of the harmonic frequency TPF2 (TPF2 peak) exceeds the threshold set in the frequency spectrum display unit 52 in the frequency spectrum of the processing vibration, the count-up value exceeding the threshold is The value is sent to the second display field 56b of the threshold value exceeding display unit 56. In the second display field 56b, the count-up value of TPF2 is accumulated and displayed. Accordingly, the graph displayed in the second display field 56b of the threshold value excess integration display unit 56 is cumulatively added every time a count-up value exceeding the threshold value of TPF2 is sent.

  Further, when the vibration of the harmonic frequency TPF3 (TPF3 peak) exceeds the threshold value set in the frequency spectrum display unit 52, the count-up value exceeding the threshold value is displayed as the threshold value exceeding integration display unit. 56 is sent to the third display field 56c. On the other hand, when the vibration of the harmonic frequency TPF4 (TPF4 peak) exceeds the threshold value set in the frequency spectrum display unit 52, the count-up value exceeding the threshold value is the threshold value exceeding integration display unit. 56 is sent to the fourth display field 56d. Furthermore, when the vibration of the TPF harmonic frequency other than TPF1 to TPF4 exceeds the threshold value set in the frequency spectrum display unit 52, the count-up value exceeding the threshold value is displayed as the integrated value exceeding the threshold value. They are collectively displayed in the fifth display field 56e of the part 56.

  The change display unit 58 compares the accumulated count-up values in the first display column 56a to the fourth display column 56d (including the fifth display column 56e as necessary) of the frequency spectrum display unit 52, and displays them over time. At that time, the parameter to be compared can be selected on a separate setting screen. Specifically, the change display unit 58 counts the accumulated TPF2, TPF3, and TPF4 (and TPFn if necessary) with respect to the accumulated count value of TPF1 (the number of times the TPF threshold has been exceeded). The sum of the up values (the number of times the harmonic TPF threshold is exceeded) is compared over time. That is, (count up value of TPF2 + count up value of TPF3 + count up value of TPF4 + count up value of TPFn) / count up value of TPF1 = comparison value.

  In the change display section 58 shown in FIG. 8, the cumulative value of the sum of the count-up values of TPF2, TPF3, and TPF4 (and TPFn if necessary) is lower than the count-up value of TPF1. The case is displayed. The comparison value is 1 or less, and it is detected that the machining state is a free-cutting state. On the other hand, in the change display section 58 shown in FIG. 9, the accumulated value of the sum of the count-up values of TPF2, TPF3, and TPF4 (and TPFn if necessary) accumulated with respect to the accumulated count-up value of TPF1. When is high is displayed. The comparison value is 2.5 or more, and it is detected that the machining state is not a free cutting state.

  In other words, from the frequency spectrum of machining vibration, only the remarkable specific signal that exceeds the threshold value at the tool pass frequency and its harmonic frequency is taken out, and the machining status is good by comparing the generation status of the specific signal. Whether or not can be displayed by a numerical value and a graph. The selection of what to compare with the accumulated value of the type display window of the threshold value exceeding display unit 56 is arbitrary.

  In this case, in the present embodiment, when the workpiece W is processed through the cutter 22, the correlation between the number of peak occurrences at the tool passing frequency (TPF1) and the number of peak occurrences at the harmonic frequency (TPF2). Can see. In a good machining state, the number of peak occurrences at the tool passing frequency becomes relatively significant, whereas in a poor machining state, the number of peak occurrences at the harmonic frequency increases with the tool passing frequency. For this reason, from the change in the relationship between the two, it is possible to obtain an effect that the quality determination of the machining state can be performed with high accuracy and efficiency.

  Further, the change display portion 58 has a threshold for determining a change in the ratio between the number of peak occurrences at the tool passing frequency (TPF1) and the sum of the number of peak occurrences at a plurality of harmonic frequencies (TPF2). A value is set, and a determination signal in a compared state is output. For example, when the comparison value is 1 or less, an OK signal is output as indicating free-cutting properties (good machining state). Furthermore, if the comparison value exceeds 1, the output signal becomes a + OK signal, indicating that it is in a predictive state, while if the comparison value exceeds 2.5, an NG signal is output and non-free cutting It is output that it is in a state (bad machining state).

  Moreover, by monitoring the relationship between the vibration at the TPF 1 and the vibration at the harmonic frequency (TPF 2 to 2) included in the frequency spectrum of the machining vibration, the judgment of the machining state from time to time is effectively performed, and automatic machining is performed. When performed, it is possible to automate the determination of whether or not free-cutting is being performed by monitoring the comparison value.

  Here, when the cumulative comparison value displayed on the change display unit 58 is related to the wear of the tool cutting edge, the output of the comparison value signal can be used as a tool change signal. For example, when the cutting edge is sharp and acute, the change in the cumulative comparison value is small. However, as the machining progresses and the wear of the blade advances, the change in the cumulative comparison value increases. For this reason, an effective cutting edge replacement process can be performed by using the cumulative comparison value to determine the timing of cutting edge replacement.

  Furthermore, if the machining load fluctuates during machining, for example, chipping occurs at the cutting edge during machining or the machining allowance of the workpiece W changes unnecessarily, the number of peaks occurring at the tool passing frequency will be In comparison, the number of peak occurrences at higher harmonic frequencies (TPF2) tends to increase. Therefore, the cumulative comparison value displayed on the change display unit 58 can be used as a machining state monitoring function.

  4 and 6 show the difference in the vibration state of machining (cutting) due to the difference in the number of revolutions, but when searching for the optimum number of revolutions while changing the number of revolutions to cut, It can be used as a means for judging whether to show free-cutting properties. Specifically, it is possible to use the rotational speed at which the comparison value is reduced to determine that the processing conditions are good.

DESCRIPTION OF SYMBOLS 10 ... Machining state monitoring system 12 ... Machine tool 14 ... Housing 18 ... Spindle 20 ... Tool holder 22 ... Cutter 26 ... Acceleration sensor 28 ... Microphone 30 ... Controller 32 ... Machine control board 34 ... Control operation board 38 ... Arithmetic unit 40 ... Input Setting unit 44 ... Processing state determination unit 46 ... Input / output unit 48 ... Display unit 52 ... Frequency spectrum display unit 56 ... Over-threshold integration display units 56a to 56e ... Display field 58 ... Change display unit

Claims (4)

A vibration monitoring method for a working machine that develops a processing vibration detected during machining into a frequency spectrum composed of frequency and acceleration by Fourier series expansion,
The TPF peak, which is the peak acceleration at the tool passing frequency calculated from the number of rotations of the machining tool and the number of blades, is compared with the TPF threshold value, which is the peak threshold value of the tool passing frequency set in advance in the frequency spectrum. Displaying the number of times the TPF peak has exceeded the TPF threshold on the TPF threshold value exceeding display section;
A harmonic TPF peak that is a peak acceleration at a harmonic frequency that is an integral multiple of the tool passing frequency is compared with a harmonic TPF threshold that is a peak threshold of the harmonic frequency preset in the frequency spectrum. And displaying the number of times the harmonic TPF peak exceeds the harmonic TPF threshold on the harmonic TPF threshold exceeding integrated display section;
Comparing the number of times the TPF threshold has been exceeded and the number of times the harmonic TPF threshold has been exceeded and displaying the comparison on the change display section;
A vibration monitoring method for a work machine, comprising: 2. The vibration monitoring method according to claim 1, wherein the harmonic TPF threshold value exceeding integrated display unit has at least a first harmonic TPF peak at a harmonic frequency twice the tool passing frequency as the harmonic. A first harmonic TPF threshold value exceeding integration display section for displaying the number of times the TPF threshold value is exceeded;
A second harmonic TPF threshold value overrun display section for displaying the number of times the second harmonic TPF peak at the harmonic frequency three times the tool passing frequency exceeds the harmonic TPF threshold value;
Have
The change display unit displays the TPF threshold value exceeding number by comparing at least the sum of the first harmonic TPF threshold value exceeding number and the second harmonic TPF threshold value exceeding number. Monitoring method for working machine. A vibration monitoring system for a working machine that develops processing vibration detected during machining into a frequency spectrum composed of frequency and acceleration by Fourier series expansion,
The TPF peak, which is the peak acceleration at the tool passing frequency calculated from the number of rotations of the machining tool and the number of blades, is compared with the TPF threshold value, which is the peak threshold value of the tool passing frequency set in advance in the frequency spectrum. A TPF threshold value exceeding integration display unit for displaying the number of times the TPF peak exceeds the TPF threshold value;
A harmonic TPF peak that is a peak acceleration at a harmonic frequency that is an integral multiple of the tool passing frequency is compared with a harmonic TPF threshold that is a peak threshold of the harmonic frequency preset in the frequency spectrum. A harmonic TPF threshold value exceeding integration display section for displaying the number of times the harmonic TPF peak exceeds the harmonic TPF threshold value;
A change display section for comparing and displaying the number of times the TPF threshold is exceeded and the number of times the harmonic TPF threshold is exceeded;
A vibration monitoring system for a work machine, comprising: 4. The vibration monitoring system according to claim 3, wherein the harmonic TPF threshold value exceeding integrated display unit has at least a first harmonic TPF peak at a harmonic frequency twice as high as the tool passing frequency. A first harmonic TPF threshold value exceeding integration display section for displaying the number of times the TPF threshold value is exceeded;
A second harmonic TPF threshold value overrun display section for displaying the number of times the second harmonic TPF peak at the harmonic frequency three times the tool passing frequency exceeds the harmonic TPF threshold value;
With
The change display unit displays the TPF threshold value exceeding number by comparing at least the sum of the first harmonic TPF threshold value exceeding number and the second harmonic TPF threshold value exceeding number. Vibration monitoring system for working machines.

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