JP2007304031A - Abnormality diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abnormality diagnostic apparatus, capable of normally performing abnormality diagnosis of a bearing with high precision by reducing the variations of vibration amplitude, due to the rotational speed of a bearing and reducing variation of S/N of vibration frequency spectrum due to the variation of the rotational speed. <P>SOLUTION: This abnormality diagnostic apparatus for diagnosing abnormalities of the bearing comprises a vibration detector which detects vibration of the bearing, an A/D converter for performing A/D conversion to a vibration signal output from the vibration detector, and an operation processing part which diagnoses abnormality of the bearing based on the output of the A/D converter, and is equipped with an amplification degree switching circuit which changes the amplitude of the vibration signal output from the vibration detector, according to the rotation speed of the bearing. In the operation processing part or the amplification degree switching circuit, the amplitude is controlled so that it becomes constant, regardless of the rotational speed of the bearing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an abnormality diagnosing device capable of diagnosing an abnormality such as a scratch on a bearing used for supporting a railcar or an automobile axle without disassembling the bearing.

As a conventional abnormality diagnosis technique, for example, there is one disclosed in Patent Document 1. In this Patent Document 1, mechanical vibrations generated in an operating machine device are detected by some method, frequency analysis of detected data is performed, and abnormal vibrations are detected by comparing the obtained frequency spectrum and excitation frequency. This is disclosed (see Patent Document 1).
JP-A-8-219873

  By the way, the amplitude of the vibration generated from the bearing varies depending on the rotational speed of the bearing generating the vibration. For this reason, even if the scratches generated on the bearing are the same, the amplitude of vibration changes depending on the rotational speed of the bearing. However, since the above-described conventional abnormality diagnosis technique does not consider the change in the amplitude of vibration caused by the rotational speed of the bearing, there is a possibility of performing frequency analysis based on data in which the S / N ratio is not stable. . In particular, it is conceivable that the S / N ratio at the time of low rotation is deteriorated and erroneous detection is easily performed at the time of low rotation.

  The present invention has been made for the above-mentioned circumstances, and an object of the present invention is to reduce the fluctuation of the vibration amplitude due to the rotation speed of the bearing and to change the S / N of the frequency spectrum of the vibration due to the fluctuation of the rotation speed. It is an object of the present invention to provide an abnormality diagnosing device that can always perform bearing abnormality diagnosis with high accuracy.

  The present invention relates to an abnormality diagnosis apparatus for diagnosing a bearing abnormality. The object of the present invention is to detect a vibration of a bearing and a vibration signal output from the vibration detector. An AD converter for conversion, and an arithmetic processing unit for diagnosing abnormality of the bearing based on the output of the AD converter, and the amplitude of the vibration signal output from the vibration detector This is achieved by providing an amplification degree switching circuit that changes according to the speed.

  Also, the object of the present invention is to generate an amplification degree switching signal for switching the degree of increase / decrease of the amplitude on the arithmetic processing unit side and control the amplitude to be constant regardless of the rotation speed of the bearing. Alternatively, the amplification degree switching signal for switching the degree of increase / decrease in the amplitude is generated in the amplification degree switching circuit, and the amplitude is controlled so as to be constant regardless of the rotation speed of the bearing. Is achieved. Further, the rotation detector for detecting the rotation speed of the bearing is a rectangular wave output type rotation detector, and generates an AD conversion trigger signal phase-synchronized with a rotation pulse generated from the rotation detector. Further comprising phase synchronization control means for sending to the AD converter, the arithmetic processing unit performs Fourier transform based on the vibration signal data after the amplitude is corrected according to the rotation speed by the amplification degree switching circuit. Analyzing the vibration frequency, comparing the peak frequency included in the obtained power spectrum with the characteristic frequency of the abnormal component of each member constituting the bearing, and identifying the abnormal part of the bearing The arithmetic processing unit averages the spectral intensities of a plurality of power spectra obtained by executing the vibration frequency analysis processing a plurality of times, -Further comprising a temperature detection means for detecting the bearing abnormality based on the spectrum, and detecting the temperature of the bearing, wherein the arithmetic processing unit is based on the vibration signal data and the temperature detection data. Thus, the bearing abnormality diagnosis process is performed more effectively.

  According to the present invention, a bearing abnormality diagnosis can always be maintained with high accuracy regardless of the rotational speed (speed). Specifically, in the abnormality diagnosis device according to the present invention, the amplitude of the vibration signal can be changed in accordance with the rotational speed of the bearing, so that the fluctuation in the amplitude of the vibration signal is reduced and the vibration due to the fluctuation in the rotational speed is reduced. The fluctuation of the amplitude value (peak value of the frequency spectrum) can be suppressed, and the bearing abnormality diagnosis can always be performed with high accuracy.

Hereinafter, with regard to the best mode for carrying out the present invention, the case of diagnosing the presence or absence of an abnormality such as a flaw is taken as an example with a bearing (bearing for supporting an axle) in a bearing device for an axle of a railway vehicle as a diagnosis target. explain.
(First embodiment)
FIG. 1 is a block diagram showing a first embodiment of an abnormality diagnosis apparatus according to the present invention. In the present embodiment, a bearing to be subjected to abnormality diagnosis is, for example, a rolling bearing disposed in a bearing device for an axle of a railway vehicle. As shown in FIG. 1, the bearing 1 for a railway vehicle is attached to a vehicle body side housing. An outer ring 1a fitted inside, an inner ring 1b fitted around the axle and rotating together with the axle, and a plurality of rolling elements (balls or rollers) 1c disposed so as to roll between the outer ring 1a and the inner ring 1b. And.

  The abnormality diagnosis device 2 according to the present invention is intended to detect the occurrence and a sign of an abnormality such as a scratch or peeling of the bearing, with a rolling bearing used in such a railway vehicle or the like as a diagnosis target.

  In the present embodiment, the abnormality diagnosis device 2 includes a vibration detection unit 10 for detecting vibration generated from the bearing 1 and an arithmetic processing unit 20 that diagnoses an abnormality of the bearing 1 based on an output from the vibration detection unit 10. I have. The vibration detection unit 10 in the abnormality diagnosis device 2 includes a vibration detector 11a as a vibration detection unit that converts vibration generated from the bearing 1 in the axle bearing device into a vibration signal that is an electric signal, and an amplitude of the vibration signal. Amplitude switching circuit 12 serving as an amplitude variable means for changing the frequency according to the rotational speed of bearing 1, AD converter 13a for AD converting the vibration signal, and rotational speed for detecting the rotational speed (or rotational speed) of bearing 1 A rotation detector 11b as means and an AD converter 13b for AD-converting a signal generated from the rotation detector 11b are provided. The vibration detector 11a outputs, for example, a signal indicating the vibration frequency and intensity (acceleration) of the vibration of the bearing 1 detected by the vibration detection sensor. In the case of a bearing having a vibration detection sensor and a rotation detection sensor, the vibration detector 11a and the rotation detector 11b in the vibration detection unit 10 are not necessary. The vibration signal and the rotation signal output from the sensor unit are input and processed.

  The arithmetic processing unit 20 in the abnormality diagnosis device 2 has a function of diagnosing the abnormality of the bearing 1 based on the output from the vibration detection unit 10. In this example, the arithmetic processing unit 20 is connected to the control system of the railway vehicle. A control signal corresponding to the abnormality diagnosis result is output to the control system. The railroad vehicle control system constantly monitors the diagnostic results fed back from the arithmetic processing unit 20 while the vehicle is running, and when an abnormality in the bearing 10 or its sign is detected, an appropriate response action is immediately implemented.

  In the present invention, by controlling the amplitude of the vibration signal detected by the vibration detector 11a according to the rotational speed of the bearing 1, the peak value of the frequency spectrum of vibration due to the fluctuation of the rotational speed of the bearing 1 is achieved. To suppress fluctuations. This control is performed by the arithmetic processing unit 20 or the vibration detection unit 10. In the first embodiment, the above control is performed by a command (amplification degree switching signal) from the arithmetic processing unit 20, and the arithmetic processing unit 20 uses a vibration signal (this example) from the vibration detector 11a. Then, the vibration data from the AD converter 13a) and the rotation signal from the rotation detector 11b (in this example, the detection data of the rotation speed of the bearing 1 from the AD converter 13b) are input, and according to the rotation speed of the bearing 1. Thus, by generating an amplification degree switching signal for switching the amplitude increase / decrease degree of the vibration signal of the bearing 1 and sending it to the amplification degree switching circuit 12 in the vibration detection unit 10, the amplitude value of the vibration signal from the vibration detector 11a ( The output of the AD converter 13a is controlled to be constant regardless of the rotation speed of the bearing 1.

  The amplification degree switching circuit 12 can be constituted by, for example, an inverting amplification circuit of an operational amplifier and a multiplexer that switches its input resistance, but the circuit configuration of the amplification degree switching circuit 12 is not limited to this. In addition, a plurality of output signal forms such as a voltage output, a sine wave output, a rectangular wave output, and the like are conceivable as the output signal form of the rotation detector 11b. In this embodiment, voltage output is described as an example, but the present invention is not limited to this.

  In the configuration as described above, an example of the operation of the arithmetic processing unit of the abnormality diagnosis apparatus according to the first embodiment will be described with reference to the flowchart of FIG.

  The arithmetic processing unit 20 in the abnormality diagnosis apparatus acquires detection data of the rotation speed of the bearing 1 from the rotation detector 11b of the vibration detection unit 10 via the AD converter 13a (step S1), and obtains the rotation speed of the bearing 1. A corresponding amplification degree switching signal is generated. As described above, the amplification degree switching signal is a control signal for suppressing fluctuations in the amplitude of vibration (peak value of the frequency spectrum) due to fluctuations in the rotational speed of the bearing 1. The amplitude amplification degree corresponding to the rotation speed of the bearing 1 is obtained from correspondence information (setting information based on actual measurement or theoretical calculation) or a function equation indicating the correspondence between the rotation speed of the vibration signal and the amplitude amplification degree of the vibration signal. An amplification degree switching signal for switching to the amplification degree is sent to the amplification degree switching circuit 12 in the vibration detection unit 10, and the amplitude of the vibration signal from the vibration detector 11a is changed (increase / decrease) by the amplification degree switching circuit 12 to rotate. Control is performed so that the amplitude is constant regardless of the speed. In other words, the amplitude amplification by the amplification switching circuit 12 is switched according to the rotational speed, and the amplitude value of the vibration signal from the vibration detector 11a is corrected so as to be constant, thereby accompanying the fluctuation of the rotational speed. Control is performed so that the fluctuation of the S / N of the frequency spectrum of vibration becomes small (step S2).

  The arithmetic processing unit 20 acquires vibration data (output of the A / D converter 13a) after amplitude correction from the vibration detection unit 10 (step S3), and performs frequency analysis by performing fast Fourier transform (FFT) on the vibration data. The peak frequency included in the obtained power spectrum is compared with the characteristic frequency obtained from the bearing specifications (the number and diameter of the rolling elements 1c) and the rotational speed of the bearing 1, and the bearing 1 is separated. Detect anomalies.

  Specifically, as shown in steps S4 to S12, first, the arithmetic processing unit 20 performs a filtering process for removing signals in unnecessary frequency bands from the vibration data acquired in step S3 (step S4), and then extracted. The envelope processing for detecting the envelope (envelope waveform) of the signal in the predetermined frequency band is performed (step S5). Then, frequency analysis of the envelope obtained by the envelope processing is performed (step S6).

  Then, from the power spectrum obtained by the frequency analysis, a frequency (spectrum intensity) that becomes a peak in the frequency band (described later) of each flaw component that is regarded as abnormal is extracted (step S7).

  Then, an average value of spectrum intensities in other frequency bands is calculated (step S8), a reference value is set based on the average value (step S9), and the reference value is compared with a characteristic frequency regarded as abnormal. (Step S10).

  Here, the characteristic frequency regarded as abnormal will be described.

  The vibration frequency when a defect such as a scratch occurs in the bearing 1 varies depending on the component (each member) of the bearing 1, but the frequency band of each component regarded as abnormal is the rotational frequency fr of the inner ring 1b that rotates with the axle. It is possible to obtain based on

  Table 1 below shows the defect of each member that is a component of the bearing 1, specifically, scratches and each member (the inner ring 1b, the outer ring 1a and the rolling element 1c in FIG. 1, and a cage not shown). The relationship with the abnormal vibration frequency (frequency after envelope processing) which generate | occur | produces is shown.

この関係から明らかなように、各異常振動周波数において、内輪回転周波数ｆｒ以外のパラメータ（ｆｉ、ｆｃ、ｆｂ）は、軸受諸元を用いてｆｒの定数倍として表すことができる。そこで、本実施の形態では、軸受１の各異常成分（本例では傷成分）の特徴周波数（Ｚｆｉ、Ｚｆｃ、２ｆｂ、ｆｃ）を回転周波数ｆｒで正規化して得るようにしている。

As is apparent from this relationship, at each abnormal vibration frequency, parameters (fi, fc, fb) other than the inner ring rotation frequency fr can be expressed as a constant multiple of fr using the bearing specifications. Therefore, in the present embodiment, the characteristic frequency (Zfi, Zfc, 2fb, fc) of each abnormal component (scratch component in this example) of the bearing 1 is normalized by the rotation frequency fr.

  In step S10, the reference value set in step S9 is compared with the characteristic frequencies (Zfi, Zfc, 2fb, fc) of each flaw component.

  If all the characteristic frequencies (Zfi, Zfc, 2fb, fc) are equal to or less than the reference value, it is determined that there is no abnormality in the bearing 1 (step S11). On the other hand, if any one of the characteristic frequencies (Zfi, Zfc, 2fb, fc) exceeds the reference value, it is determined that there is an abnormality in the bearing 1, an abnormal part is identified based on the characteristic frequency, and the diagnosis result A control signal corresponding to the control signal is output to the control system of the railway vehicle, and for example, information indicating that fact is displayed on a monitor or the like (step S12).

As described above, the amplitude value of the vibration signal output from the vibration detector is changed according to the rotational speed of the bearing, that is, the amplitude value of the vibration signal sent to the AD converter at an arbitrary rotational speed is made to be close to a constant value. The absolute value of the peak of the frequency spectrum obtained by frequency analysis of the vibration signal can be kept substantially constant, and the bearing abnormality diagnosis can always be performed with high accuracy. Further, it is not necessary to calculate and set the frequency band regarded as abnormal by the arithmetic processing unit 20 based on the rotation frequency of the bearing, and can be set in advance based on the specifications of the bearing 1. Further, since the abnormality diagnosis of the bearing 1 is performed based on the ratio of the spectral intensity of the characteristic frequency included in the vibration generated when the bearing 1 is abnormal and the spectral intensity of other frequencies, the influence of noise on the abnormality diagnosis is minimized. This makes it possible to carry out extremely reliable diagnosis. That is, even when there is no abnormality in the bearing 1 itself, a peak of spectral intensity may be detected in the band of the apparent frequency (Zfi, Zfc, 2fb, fc) due to the influence of noise. Since the spectrum intensity of the spectrum in the frequency band also apparently increases due to the influence of noise, an erroneous determination due to the influence of noise can be eliminated by making a diagnosis based on the ratio between the two.
(Second Embodiment)
FIG. 3 is a block diagram showing a second embodiment of the abnormality diagnosis apparatus according to the present invention corresponding to FIG. The same reference numerals are attached and the description is simplified or omitted.

  The abnormality diagnosis device 2A shown in FIG. 3 has a configuration in which the rotation signal from the rotation detector 11b is input by the amplification degree switching circuit 12A and the amplitude of the vibration signal from the vibration detector 11a is changed according to the rotation signal.

  In the first embodiment described above, the calculation processing unit 20 generates an amplification switching signal, and the amplitude switching signal is changed according to the rotation speed by the amplification switching signal. In the embodiment, the increase / decrease control (amplification degree switching control) is performed in the vibration detector 10A. That is, in the abnormality diagnosis device 2A in the second embodiment, the vibration detection unit 10A has a function of switching the amplification degree as compared with the first embodiment, and in this example, in the amplification degree switching circuit 12A. The switching control is performed. The means for realizing the amplification degree switching control (amplification degree switching control means) is realized, for example, by providing the amplification degree switching circuit 12A with a comparison circuit (which can be realized by a comparator or the like) for making an amplification degree switching signal. . That is, in the second embodiment, the amplification degree switching circuit 12A shown in FIG. 3 is compared in terms of hardware as the amplification degree switching control means in addition to the amplification degree switching circuit 12 of the first embodiment. It has a circuit.

  An operation example of the abnormality diagnosis apparatus according to the second embodiment having the above-described configuration will be described.

  First, an operation example of the vibration detection unit 10A will be described.

  The amplification degree switching circuit 12A in the vibration detection unit 10A receives a rotation signal of the bearing 1 generated from the rotation detector 11b, and an optimum amplitude amplification degree with respect to the current rotation speed, for example, vibration, according to the rotation signal. An amplitude amplification degree is determined so that the amplitude value of the signal is constant regardless of the rotation speed of the bearing 1. The amplitude amplification degree is set by, for example, comparing the setting value (reference value) of the amplitude amplification degree for each rotation speed or speed range with the current rotation speed by a comparison circuit, and setting the amplitude amplification degree corresponding to the current rotation speed. Obtained by selecting a value. Alternatively, the current rotational speed is set to a function formula, and the amplitude amplification degree is obtained by function calculation. Then, an amplification switching signal for switching to the amplitude amplification is generated, the vibration signal from the vibration detector 11a is changed by the amplification switching signal, and the amplitude of the vibration signal detected by the vibration detector 11a is the bearing. It adjusts so that it may become constant irrespective of the rotational speed of 1. Then, the adjusted vibration signal is sent to the A / D converter 13a.

  Next, an operation example of the arithmetic processing unit 20A will be described with reference to the flowchart of FIG.

  In the second embodiment, as described above, since the amplitude of the vibration signal has already been corrected on the vibration detection unit 10A side, the switching control of the amplitude amplification degree on the arithmetic processing unit 20A side becomes unnecessary.

That is, the abnormality diagnosis device 2A according to the first embodiment generates, in terms of software, a step of generating an amplification degree switching signal in the arithmetic processing unit 20A as compared with the first embodiment (Step S1 “bearing of FIG. 2”). "Rotational speed acquisition" and step S2 "Output of amplification degree switching signal") are not required. The processing in steps S21 to S30 in the flowchart in FIG. 4 is the same as the processing in steps S3 to S12 in the flowchart in FIG. 2 already described in the first embodiment, and a description thereof will be omitted.
(Third embodiment)
Next, a third embodiment will be described. In the first and second embodiments described above, the configuration assuming a voltage output type rotation detector has been described as an example. In the third embodiment, an example assuming a rectangular wave output type rotation detector is described. To do.

  FIG. 5 is a block diagram showing a third embodiment of the abnormality diagnosis apparatus according to the present invention corresponding to FIG. 3, and the same components as those of the second embodiment (abnormality diagnosis apparatus 2A illustrated in FIG. 3) are as follows. The same reference numerals are attached and the description is simplified or omitted.

  In the abnormality diagnosis device 2B shown in FIG. 5, the rotation detector 11b ′ for detecting the rotation speed of the bearing 1 is a rectangular wave output type rotation detector, and a predetermined number (for example, each time the bearing 1 rotates) 60) of the pulse signal (rotation pulse). The vibration detector 10B generates and oscillates a signal (AD conversion trigger signal) that is phase-synchronized with the rotation pulse generated from the rotation detector 11b ′, and uses a PLL (Phase locked loop) as its phase synchronization control means. A circuit 14 is provided. In the arithmetic processing unit 20A, the frequency of the AD conversion trigger signal from the PLL circuit 14 is used as a sampling frequency, and the data of the vibration signal from the vibration detector 11 is sampled via the amplification degree switching circuit 12B and the AD converter 13A.

  Compared with the first and second embodiments, the amplification degree switching circuit 12B in the vibration detection unit 10B converts the frequency change of the rotation pulse generated from the rotation detector 11b ′ into a voltage level change. As a frequency-voltage conversion circuit. Since the other configuration and operation of the amplification degree switching circuit 12B and the configuration and operation of the arithmetic processing unit 20A are the same as those in the second embodiment, description thereof will be omitted. Here, a configuration example of the PLL circuit 14 and its operation will be omitted. explain. Note that a temperature detector 31 and an AD converter 32 which are components of the temperature detecting means 30 in FIG. 5 detect the temperature of the bearing 1 and diagnose the abnormality of the bearing 1 based on the detected temperature. The description of the abnormality diagnosis apparatus that is an additional component and to which the component is added will be described later.

  In FIG. 5, the PLL circuit 14 is configured by a loop circuit including a phase comparator 14a, a loop filter 14b, a voltage controlled oscillator (VCO) 14c, and a frequency divider 14d. The phase comparator 14a in the PLL circuit 14 divides the rotation pulse output from the rotation detector 11b and the oscillation signal (AD conversion trigger signal) from the VCO 14c in the PLL circuit 14 by the frequency divider 14d. The obtained divided pulse is input. Then, the phase comparator 14a generates a pulse signal corresponding to the phase difference between the rotation pulse and the divided pulse and sends it to the loop filter 14b. The loop filter 14b sends a DC signal corresponding to the pulse signal to the VCO 14c. The VCO 14c sends a pulse signal having a frequency corresponding to the input voltage to the AD converter 13a as an AD conversion trigger signal. The AD converter 13a outputs vibration data obtained by sampling the vibration signal from the vibration detector 11 via the amplification degree switching circuit 12B using the frequency of the AD conversion trigger signal as a sampling frequency.

  By adopting such a configuration, synchronous pull-in is performed so that the phases of both the rotation pulse from the rotation detector 11b and the frequency division pulse from the frequency divider 14d coincide with each other. A proportional relationship can be established between the frequency of the rotation pulse from the rotation detector 11b and the frequency of the AD conversion trigger signal. As a result, by negating the influence of the fluctuation of the vibration frequency due to the fluctuation of the rotation frequency of the bearing 1, it is possible to suppress the dullness of the peak of the frequency spectrum of the vibration due to the fluctuation of the rotation frequency. Further, as described above, in the amplification degree switching circuit 12B, the fluctuation of the amplitude of the vibration signal due to the fluctuation of the rotational speed is reduced, and therefore, it may be affected by the fluctuation of the rotational frequency and the rotational speed of the bearing 1. Therefore, abnormality diagnosis can always be performed with high accuracy.

In the third embodiment described above, the switching control of the amplification degree of the vibration signal is performed on the vibration detector 10B side (in the amplification switching circuit 12B) as an example. However, the switching control is performed by the arithmetic processing unit. When performing on the 20A side, the vibration detection unit 10 of the abnormality diagnosis device 2 of FIG. 1 illustrated in the first embodiment may be configured to include the PLL circuit 14 in FIG.
(Another embodiment 1 of the arithmetic processing unit)
In the above-described embodiment, the arithmetic processing unit (20 or 20A) analyzes the vibration frequency of the bearing 1 based on the vibration data from the vibration detection unit (10, 10A, or 10B), and obtains the obtained power spectrum. In the above description, the case where the abnormality of the bearing 1 is detected by comparing the peak frequency included in the bearing and the characteristic frequency of the abnormal component of each member constituting the bearing has been described as an example. The vibration frequency analysis process is performed a plurality of times, and after performing the frequency averaging process that averages the spectrum intensities of the obtained power spectra, the diagnosis may be made based on the power spectrum data. preferable.

  FIG. 6 is a flowchart showing an operation example in the case where the frequency averaging process is performed in the arithmetic processing unit 20A of the abnormality diagnosis apparatus. Compared with the flowchart of FIG. 4 used in the description of the second embodiment, FIG. Steps S31 and S36 to S38 in Step 6 are added. Here, the added process will be described, and the other processes (steps S32 to S35 and S39 to S44 in FIG. 6) are the processes in the second embodiment (steps S21 to S24 and S25 to S30 in FIG. 4). Since it is the same as that, description is abbreviate | omitted.

In the arithmetic processing unit 20A of the abnormality diagnosis device, vibration data after amplitude correction is acquired from the vibration detection unit 10, and the processing from step S32 to step S35 is repeated a specified number of times (in this example, N = 10 times), A plurality of (N) power spectrum data are sampled by frequency analysis (steps S31 to S37). In step S38, a process (frequency averaging process) is performed to average the spectrum intensity of the power spectrum for each frequency of the sampled power spectrum. In step S39 and subsequent steps, an abnormality diagnosis of the bearing 1 is performed based on the power spectrum data after the frequency averaging process. By the frequency averaging process, it is possible to further suppress the dullness of the peak of the vibration frequency spectrum due to the fluctuation of the rotation frequency.
(Other embodiment 2 in an arithmetic processing part)
In the above-described embodiment, the case where the bearing abnormality diagnosis process is performed based on the vibration signal of the bearing 1 detected by the vibration detector is described as an example. However, the temperature state is diagnosed together with the vibration state of the bearing 1. Thus, various abnormalities of the bearing can be detected with higher accuracy. In that case, temperature detection means 30 (temperature detector 31 and AD converter 32) is added as temperature detection means of the bearing 1 as illustrated in FIG. 5, and the vibration data and temperature of the bearing 1 are calculated in the arithmetic processing unit 20A. A bearing abnormality diagnosis process may be executed based on the data.

  An example of the abnormality diagnosis process using the temperature data will be described according to the process flow of FIG.

  FIG. 7 is a flowchart showing the processing contents in the arithmetic processing unit of the abnormality diagnosis apparatus shown in FIG. The same applies when applied to the first and third embodiments.

  When performing abnormality diagnosis, the arithmetic processing unit 20A first sets the temperature data acquisition count value M to an initial value (M = 0) (step S51), and sets a threshold value for determining temperature abnormality. This threshold value is selected based on actual measurement or theoretical calculation, and is preset by, for example, an operator (step S52). Subsequently, after performing abnormality diagnosis processing due to vibration of the bearing 1 according to the flow of FIG. 2 (step S53), temperature data of the bearing 1 detected by the temperature detector 31 is acquired via the AD converter 32 (step S54). ). And the influence of the noise superimposed at the time of AD conversion is reduced by carrying out the moving average process of the acquired temperature data. The moving average processed temperature data is stored in a memory (step S55). Thereafter, the value M of the temperature data acquisition count is incremented (M = M + 1) (step S56), the process returns to step S53, and the process up to step S55 is repeated. If it is determined in step S57 that the specified number of times (M = 10 in this example) has been repeated, the value of the temperature data after the moving average process is compared with the temperature abnormality threshold (step S58).

  If the value of the temperature data is less than the threshold value, it is determined that there is no abnormality in the bearing 1 (step S59). On the other hand, if the value of the temperature data is equal to or greater than the threshold value, it is determined that the bearing 1 has a temperature abnormality, and a control signal corresponding to the diagnosis result is output to the control system of the railway vehicle, and information indicating this is monitored, for example. (Step S60). Accordingly, when a vibration or temperature abnormality of the bearing 1 is detected, the control signal is output to the railway vehicle control system and a diagnosis result is displayed.

  As described above, according to this embodiment, in addition to the abnormality determination based on the vibration of the bearing, the abnormality determination based on the temperature of the bearing can be performed, so that the abnormality determination with higher reliability can be performed.

  Since the abnormality determination based on the temperature is made based on the temperature of the bearing 1 at that time, it is not necessary to perform a process of making the sampling frequency fs proportional to the rotation frequency fr of the bearing 1 as in the case of the abnormality determination due to vibration. . Therefore, the abnormality determination process using temperature can be performed between the abnormality determination processes using vibration. Therefore, in the configuration illustrated in FIG. 5, an example is shown in which AD converters are separately provided for vibration and temperature, but it is also possible to share one AD converter.

  In the above-described embodiment, a case where a bearing for a railway vehicle is a diagnosis target has been described as an example. However, the bearing is not limited to a bearing for a railway vehicle, and a bearing used for all vehicles such as an automobile and a ship. Can be a diagnostic target. In the above-described embodiment, the case where the vibration detection unit is configured by hardware has been described as an example. However, the present invention includes a case where a part is configured by software. Furthermore, the present invention is not limited to the above-described embodiments, and modifications, improvements, combinations of the embodiments, and the like can be appropriately made. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in each embodiment described above are arbitrary and not limited as long as the present invention can be achieved.

1 is a block diagram showing a first embodiment of an abnormality diagnosis apparatus according to the present invention. It is a flowchart for demonstrating the operation example of the arithmetic processing part of the abnormality diagnosis apparatus in 1st Embodiment. It is a block diagram which shows 2nd Embodiment of the abnormality diagnosis apparatus which concerns on this invention. It is a flowchart for demonstrating the operation example of the arithmetic processing part of the abnormality diagnosis apparatus in 2nd Embodiment. It is a block diagram which shows 3rd Embodiment of the abnormality diagnosis apparatus which concerns on this invention. It is a flowchart for demonstrating the operation example of other Embodiment 1 in the arithmetic processing part of the abnormality diagnosis apparatus which concerns on this invention. It is a flowchart for demonstrating the operation example of other Embodiment 2 in the arithmetic processing part of the abnormality diagnosis apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bearing 2,2A, 2B Abnormality diagnosis apparatus 10, 10A, 10B Vibration detection part 11a Vibration detection means (vibration detector)
11b, 11b ′ Rotation detection means (rotation detector)
12, 12A, 12B Amplification degree switching means (amplification degree switching circuit)
13a, 13b AD converter 14 PLL circuit 20, 20A Arithmetic processing unit 30 Temperature detection means 31 Temperature detector 32 AD converter

Claims (7)

An abnormality diagnosis device for diagnosing a bearing abnormality, a vibration detector for detecting vibration of the bearing, an AD converter for AD converting a vibration signal output from the vibration detector, and the AD converter An amplification switching circuit that changes the amplitude of the vibration signal output from the vibration detector in accordance with the rotational speed of the bearing. An abnormality diagnosis device characterized by comprising. 2. The amplification degree switching signal for switching the degree of increase / decrease of the amplitude is generated on the arithmetic processing unit side, and the amplitude is controlled to be constant regardless of the rotation speed of the bearing. The abnormality diagnosis device described. 2. An amplification degree switching signal for switching the degree of increase / decrease of the amplitude is generated in the amplification degree switching circuit, and the amplitude is controlled so as to be constant regardless of the rotation speed of the bearing. The abnormality diagnosis device described in 1. The rotation detector for detecting the rotation speed of the bearing is a rectangular wave output type rotation detector, and generates an AD conversion trigger signal phase-synchronized with a rotation pulse generated from the rotation detector to generate the AD conversion. And a phase synchronization control means for sending to the detector, wherein the arithmetic processing section samples the data of the vibration signal via the amplification degree switching circuit and the AD converter using the frequency of the AD conversion trigger signal as a sampling frequency. The abnormality diagnosis apparatus according to any one of claims 1 to 3. The arithmetic processing unit analyzes a vibration frequency by performing Fourier transform based on vibration signal data after the amplitude is corrected according to the rotation speed by the amplification degree switching circuit, and is included in the obtained power spectrum. 5. A function for identifying an abnormal portion of the bearing by comparing a peak frequency and a characteristic frequency of an abnormal component of each member that is a component of the bearing. The abnormality diagnosis device described in 1. The arithmetic processing unit averages spectral intensities of a plurality of power spectra obtained by performing the vibration frequency analysis processing a plurality of times, and diagnoses an abnormality of the bearing based on the power spectra after the averaging processing 6. The abnormality diagnosis apparatus according to claim 5, wherein processing is performed. The apparatus further comprises temperature detection means for detecting the temperature of the bearing, and the arithmetic processing unit performs a diagnosis process for abnormality of the bearing based on the data of the vibration signal and the detection data of the temperature. The abnormality diagnosis apparatus according to claim 1.

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