JP2010234403A - Device and method for diagnosing abnormality of rotary shaft of rolling mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for diagnosing abnormality, which directly receives an elastic-wave signal generated when cracks occur or develop on the rotary shaft of a rolling mill without damping the elastic wave which is generated when cracks of a material occur or develop and by removing the working noise during rolling a magnetic steel sheet or the like, and to provide a diagnostic method using the diagnosing device. <P>SOLUTION: The device is composed of an elastic wave detecting means 20 for detecting the elastic wave of the rotary shaft, the abnormality diagnostic means 23 and an input means of the screw-down signal or rotation signal of the rolling mill. The abnormality diagnostic means 23 performs diagnosis by using the abnormality diagnostic device which is provided with the functions for detecting the elastic wave which is propagated during no-load rotation from the information of the screw-down signal and the rotation signal of the rolling mill and the information of the elastic wave detected by the elastic wave detecting means 20 and for diagnosing the abnormality generated on the rotary shaft 105 or the rotary shaft and a bearing 103 by analyzing the detected elastic wave. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a diagnostic device for diagnosing abnormalities such as cracks occurring in a rotating shaft or a rotating shaft and a bearing of a rolling mill, and an abnormality diagnosing method using the diagnostic device, and more particularly, an elastic signal propagating to the rotating shaft of the rolling mill Is detected by an acoustic emission (hereinafter referred to as AE) sensor, and the presence or absence of an abnormality is diagnosed based on the detection signal.

For example, in an iron manufacturing plant equipped with a rolling mill and a conveyance line, a large number of gears and rotating shafts are provided for transmitting the driving force generated from the motor to the rolling roller and the conveyance roller. Each of these rotating shafts is supported by a bearing.
In these bearings, when fine wear powder or the like is generated during operation, the wear powder becomes a foreign matter and is mixed into the lubricating oil, causing troubles such as seizure. Further, if the bearing is used beyond the predetermined service life, breakage such as a crack is likely to occur.

  Conventionally, as a means of diagnosing the occurrence of serious damage to the bearing part, a means of measuring vibrations as an index of the plant operating state with a vibration sensor such as an accelerometer, or a material crack occurrence and progress with an AE sensor A means for measuring the generated elastic wave is used. Generally, these sensors are attached to a steel bearing box provided with a bearing.

JP-A-9-26414

As described above, in the conventional abnormality diagnosis device, the vibration sensor and the AE sensor are mounted on the steel bearing box provided with the bearing in order to detect a serious damage of the bearing portion. However, the location where an abnormality such as a crack or wear occurs is not limited to the bearing, but rather a crack often occurs on the rotating shaft itself.
In other words, in the conventional vibration sensor and AE sensor attached to the bearing box, the elastic wave generated as a result of cracking or progressing of the material is received via the bearing part, so the signal sensed by the sensor is There was a problem that it was attenuated and an accurate diagnosis could not be made.

  To deal with this problem, Patent Document 1 proposes a wireless transmission system for AE signals in which an AE sensor is attached to a rotating body as shown in FIG. However, even with this method, the influence of noise on the radio signal is unavoidable, and there is still a problem with the accuracy of the sensor attached to the rotating body. In the figure, 101 is an AE sensor, 102 is a rotating body, 103 is a bearing, 104 is a machine base, 105 is a rotating shaft, 106 is a transmitting device, and 107 is a receiving device.

  The present invention has been developed in view of the above-described situation, and suppresses the attenuation of the signal sensed by the sensor, and further effectively eliminates operating noise during rolling of the steel material, and is on the rotating shaft of the rolling mill. Providing an abnormality diagnosis device capable of accurately diagnosing an abnormality by directly receiving an elastic wave signal accompanying an abnormality such as the occurrence or development of a crack, together with a diagnosis method using this diagnosis device Objective.

That is, the gist configuration of the present invention is as follows.
(1) An apparatus for detecting an abnormality occurring in a rotating shaft of a rolling mill or a rotating shaft and a bearing, the apparatus comprising at least one elastic wave detecting means for detecting an elastic wave of the rotating shaft, and a rolling mill And an abnormality diagnosis means for diagnosing an abnormality based on information of the elastic wave detection means and the input means, and the abnormality diagnosis means includes an elastic wave detection means detected by the elastic wave detection means. An apparatus for analyzing wave information, an apparatus for detecting and analyzing an elastic wave propagating during no-load rotation from the information of the input means, and an abnormality generated on the rotating shaft, or the rotating shaft and the bearing from the analyzed elastic wave An apparatus for diagnosing abnormalities in a rotating shaft of a rolling mill.

  (2) The elastic wave detecting means is a liquid reservoir for storing a liquid in contact with a part of the rotating shaft, and an acoustic emission (AE) that is installed in contact with the liquid reservoir and detects an elastic wave propagating through the liquid. The abnormality diagnosis device for a rotating shaft of a rolling mill as described in (1) above, comprising a sensor.

  (3) The rolling according to (2), wherein in the elastic wave detecting means, a disc-shaped ring attached to a rotating shaft is configured to contact a liquid in the liquid reservoir. An abnormality diagnosis device for the rotating shaft of the machine.

  (4) In the elastic wave detecting means, a magnetic fluid is stored as a liquid in the liquid reservoir, and a magnet for holding the magnetic fluid is attached thereto. A shaft abnormality diagnosis device.

  (5) When detecting an abnormality occurring in the rotating shaft of the rolling mill or the rotating shaft and the bearing, the elastic wave detecting means provided on the rotating shaft detects the elastic wave from the rotating shaft, and the input means performs rolling. By detecting the machine's reduction signal and rotation signal, detecting the elastic wave propagating during no-load rotation from these detected elastic wave, reduction signal and rotation signal, and analyzing this detected elastic wave, the rotation axis Or an abnormality diagnosis method for a rotating shaft of a rolling mill, wherein an abnormality occurring in the rotating shaft and the bearing is diagnosed.

  (6) Elastic wave detection by the elastic wave detecting means uses a liquid reservoir in contact with a part of the rotating shaft and an acoustic emission (AE) sensor installed in contact with the liquid reservoir. The method for diagnosing abnormality of a rotating shaft of a rolling mill as described in (5) above, wherein the elastic wave propagating in the liquid is detected.

  (7) The elastic wave detection uses a disc-shaped ring attached to the rotating shaft, a liquid reservoir for storing a liquid in contact with the ring, and an acoustic emission (AE) sensor installed in contact with the liquid reservoir. The abnormality diagnosis method for a rotating shaft of a rolling mill as described in (6) above, wherein

  (8) The rolling according to (6), wherein the liquid reservoir for storing the liquid in contact with a part of the rotating shaft uses a magnetic fluid as the liquid, and a magnet for holding the magnetic fluid is attached. A method for diagnosing abnormalities in the rotating shaft of a machine.

  According to the present invention, the elastic wave propagating during no-load rotation can be directly detected, and since the signal attenuation is small, noise during rolling is effectively eliminated, and the rotating shaft of the rolling mill can be accurately detected. Can be diagnosed.

FIG. 6 is a side view of a rotating facility provided with a wireless transmission type abnormality diagnosis device disclosed in Patent Document 1. It is a side view of a rolling mill provided with the abnormality diagnosis apparatus of the rotating shaft according to this invention. It is a system block diagram of the abnormality diagnosis apparatus of the rotating shaft according to this invention. It is the side view and AA arrow view showing the detailed structure of the liquid reservoir part of the abnormality diagnosis apparatus according to this invention. It is the side view and AA arrow directional view showing the detailed structure of the liquid reservoir part of the other abnormality diagnostic apparatus according to this invention.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 2 is a side view of an abnormality diagnosis device for a rotating shaft or a rotating shaft and a bearing (hereinafter simply referred to as a rotating shaft) of a rolling mill according to the present invention. In the figure, 1a and 1b are rolling rolls, 2 is a steel material to be rolled, 3 is a bearing for supporting each rotating shaft, 4a and 4b are spindles, 5a and 5b are liquid reservoirs, and 6a and 6b are AE sensors installed in the liquid reservoirs 5a and 5b. 7a and 7b are pinion gears, 8 is a reduction gear, and 9 is an electric motor.

  In FIG. 3, the system block diagram of the abnormality diagnosis apparatus of the rotating shaft of the rolling mill according to this invention is shown. In the figure, 20 is an elastic wave detecting means (the liquid reservoirs 5a and 5b and AE sensors 6a and 6b in FIG. 2), and 21 is a preamplifier. Further, 22 is a means for inputting a rolling mill rolling signal or a rotation signal, and 23 is an abnormality diagnosing means. The abnormality diagnosing means 23 includes an AE analysis device 24, a device 25 for analyzing the reduction signal and the rotation signal, and a device 26 for diagnosing the analysis result.

As shown in FIG. 2, generally, in a steel rolling line, the output from the electric motor 9 is transmitted to the speed reducer 8 and is distributed up and down by the pinion gears 7a and 7b to drive the driving force to the spindles 4a and 4b. Is transmitted, and finally the rolling rolls 1a and 1b are rotated to roll the steel material 2. The liquid reservoirs 5a and 5b are filled with a liquid such as a magnetic fluid, lubricating oil, or water so as to come into contact with the spindles 4a and 4b. In the present invention, a magnetic fluid is particularly suitable as the liquid that contacts the spindles 4a and 4b.
Further, AE sensors 6a and 6b for detecting elastic waves generated when an abnormality such as a crack occurs in the spindles 4a and 4b are attached to the liquid reservoirs 5a and 5b.
In addition to the above-described AE sensor, a conventionally known vibration detection sensor such as a vibration sensor such as an accelerometer can be used as a sensor for detecting elastic waves.

Now, as shown in FIG. 3, the output from the elastic wave detection means 20 is amplified through the preamplifier 21 as necessary, and the AE analysis device 24 in the abnormality diagnosis means 23 performs Fourier transform or the like. Signal processing is performed. Further, the rolling means rolling signal or rotation signal is detected by the input means 22, the analysis device 25 in the abnormality diagnosis means 23 detects the no-load state when the rolling mill is not rolling, and the elasticity propagates during no-load rotation. Detect waves. Furthermore, the diagnostic device 26 has a function of diagnosing whether or not an abnormality has occurred in the spindles 4a and 4b by analyzing the elastic wave in the unloaded state of the rolling mill described above.
In FIG. 3, the input means 23 is shown as an independent form, but may be provided in the abnormality diagnosis means 24. Further, the signal of the AE analysis device 24 is shown as being input to the analysis device 25. The elastic wave propagating during no-load rotation may be detected and diagnosed.

Here, the analysis in the present invention refers to a collation target for comparison with a normal elastic wave obtained in advance or a threshold value of an arbitrary management parameter obtained from a normal elastic wave. Including the processing of the elastic wave of this and collating with the threshold value, and the diagnostic function in the present invention is such that when the diagnostic device 26 diagnoses an abnormality, it is performed until the equipment is stopped, It is not limited to a function that automatically performs everything, but a diagnostic function for the final judgment of the worker, for example, a function that simply displays a numerical value for the worker to judge when an abnormality is diagnosed. It also includes functions such as blinking this display or issuing an alarm.
The arbitrary management parameter includes the maximum value, rate of change, average value transition rate, etc. of the elastic wave, but any management parameter relating to a conventionally known vibration can be suitably used.

4 (a) and 4 (b) show a side view and a AA arrow view showing the detailed structure of the liquid reservoir of the abnormality diagnosis device according to the present invention. In the figure, 5a is a liquid reservoir, 10 is an anti-vibration rubber, and 11 is a magnet such as a permanent magnet or an electromagnet.
As shown in FIG. 2A, the liquid reservoir 5a is attached to the housing of the speed reducer 8 via a vibration isolating rubber 10 that is not affected by vibration from the pinion gear 7a. The spindle 4a is arranged so that the magnetic fluid filled in the liquid reservoir 5a contacts. As shown in FIGS. 4A and 4B, there is a slight gap between the liquid reservoir 5a and the spindle 4a. When the magnetic fluid is used as a liquid, the liquid reservoir 5a is preferably made of metal so that the magnetic fluid filled in the liquid reservoir 5a does not spill from the gap, and the magnet 11 is placed at the boundary. Is installed. However, this is not a limitation on the type of liquid, and in the case of other liquids, a holding measure corresponding to the liquid may be taken.

FIGS. 5A and 5B are a side view and a AA arrow view showing the detailed structure of the liquid reservoir of the abnormality diagnosis apparatus when a disk-shaped ring is attached to the rotating shaft according to the present invention. In the figure, 12 is a ring.
As shown in FIG. 4A, the liquid reservoir 5a is attached to the housing of the speed reducer 8 via a vibration isolating rubber 10, as in the case of FIG. As shown in FIGS. 5A and 5B, a ring 12 is attached to the outer periphery of the spindle 4a and is in contact with the liquid reservoir 5a. For this reason, there is little risk of liquid spilling from the gap between the liquid reservoir 5a and the spindle 4a. Therefore, in this case, it is not necessary to install the magnet 11 and the liquid reservoir 5a does not have to be made of metal, and the liquid can be preferably a liquid such as a normal lubricant or water. is there.
In the above-described embodiment, the case where the elastic wave detecting means (liquid reservoir (oil bath)) is installed in the middle of the rotating shaft has been described. However, the elastic wave detecting means in the portion of the rotating shaft such as the end of the rotating shaft. There is no particular limitation on the installation position, and the number of installations is not particularly limited.

Next, a diagnosis method using the abnormality diagnosis device for the rotating shaft of the rolling mill according to the present invention will be described.
The liquid filled in the liquid reservoirs 5a and 5b and in contact with the spindles 4a and 4b always generates some elastic wave while the rolling mill to be diagnosed is operating.
Here, when a crack occurs in any of the spindles 4a and 4b, an elastic wave accompanying the crack is generated. At this time, the signal from the elastic wave is directly detected by the AE sensors 6a and 6b attached to the liquid reservoirs 5a and 5b, which are the elastic wave detecting means 20, and is amplified via the preamplifier 21 to diagnose the abnormality. In the AE analysis device 24 in the means 23, signal processing such as Fourier transformation is performed, and information for diagnosing the presence or absence of abnormality is obtained.

Here, as a further feature of the present invention, a rolling mill reduction signal and a rotation signal are obtained by the input means 22, and an analysis device 25 in the abnormality diagnosis means 23 detects an unloaded state when the rolling mill is not rolling. It is to be. By introducing this method, mere large vibrations and abnormal vibrations can be reliably distinguished. In addition, since the vibration is directly detected, the vibration is less attenuated, resulting in an accurate diagnosis.
In other words, the abnormality diagnosis method according to the present invention as described above effectively eliminates noise during rolling while preventing attenuation of abnormal vibration such as normal vibration and cracks, and accurately rotates the rotating shaft of the rolling mill. It became possible to diagnose abnormalities.

  Finally, the information of the AE analyzer 24 and the analyzer 25 is integrated, and the diagnosis device 26 is used to diagnose whether the spindles 4a and 4b are abnormal. At the time of this diagnosis, the analysis is collated with the normal acoustic wave obtained in advance, but not only the waveform is collated but also the threshold value obtained from the normal acoustic wave, etc. In order to make a comparison, the method includes comparing the elastic wave to be verified with its value after performing arithmetic processing, and various conventionally known verification methods can be applied as the method. May be displayed and the operator may compare and monitor to continue the operation of the equipment, stop the equipment, etc., or mechanically collate and issue an alarm or the like to stop the equipment.

  A rotating shaft of a rolling mill that has reached a predetermined service life but has not yet cracked was prepared, and the same device as before was attached to one of the bearings in a steel bearing box. Moreover, the apparatus shown in FIG. 2 was attached to the other end of the shaft, and a simulated load and an unloading (release) were repeated. When there was a signal indicating that an abnormality was detected from the apparatus shown in FIG. 2 according to the method of the present invention, the equipment was stopped and the above rotating shaft was inspected by a penetrant flaw test in accordance with JIS Z 2343. Cracks were confirmed. At this time, the conventional apparatus did not sense any abnormality.

  According to the present invention, it is possible to diagnose the occurrence and progress of cracks by directly receiving the elastic wave signal accompanying the occurrence and progress of cracks on the rotating shaft of the rolling mill during no-load operation. It is possible to carry out stable operation of an iron manufacturing plant equipped with a rolling mill and a conveyance line.

1a and 1b rolling rolls 2 Steel to be rolled 3 Bearings for each rotating shaft
4a, 4b spindle
5a, 5b liquid reservoir
6a, 6b AE sensor
7a, 7b pinion gear 8 Reducer 9 Electric motor
10 Anti-vibration rubber
11 Magnet
12 rings
20 Elastic wave detection means
21 Preamplifier
22 Input means
23 Abnormality diagnosis means
24 AE analyzer
25 Analyzer
26 Diagnostic equipment
101 AE sensor
102 Rotating body
103 Bearing
104 stand
105 rotation axis
106 Transmitter
107 Receiver M Motor

Claims (8)

  An apparatus for detecting an abnormality occurring in a rotating shaft of a rolling mill, or a rotating shaft and a bearing, the apparatus comprising at least one elastic wave detecting means for detecting an elastic wave of the rotating shaft, and a rolling signal of the rolling mill Alternatively, a rotation signal input means, an elastic wave detection means, and an abnormality diagnosis means for diagnosing an abnormality based on the information of the input means, the abnormality diagnosis means includes information on the elastic wave detected by the elastic wave detection means. , An apparatus for detecting and analyzing an elastic wave propagating during no-load rotation from information of the input means, and an abnormality occurring in the rotating shaft or the rotating shaft and the bearing from the analyzed elastic wave is diagnosed An abnormality diagnosis device for a rotating shaft of a rolling mill.   The elastic wave detecting means includes: a liquid reservoir that stores a liquid in contact with a part of the rotating shaft; and an acoustic emission (AE) sensor that is installed in contact with the liquid reservoir and detects an elastic wave propagating through the liquid. The abnormality diagnosis device for a rotating shaft of a rolling mill according to claim 1, wherein   The rotating shaft of the rolling mill according to claim 2, wherein the elastic wave detecting means is configured such that a disc-shaped ring attached to the rotating shaft is in contact with the liquid in the liquid reservoir. Abnormality diagnosis device.   The abnormality diagnosis of the rotating shaft of the rolling mill according to claim 2, wherein in the elastic wave detecting means, a magnetic fluid is stored in the liquid reservoir as a liquid, and a magnet for holding the magnetic fluid is attached. apparatus.  When detecting abnormalities occurring in the rotating shaft of the rolling mill or the rotating shaft and the bearing, the elastic wave detecting means provided on the rotating shaft detects the elastic wave from the rotating shaft, and the rolling means reduces the rolling mill by the input means. By detecting the signal and rotation signal, and detecting the elastic wave propagating during no-load rotation from the detected elastic wave, rolling-down signal, and rotation signal, and analyzing the detected elastic wave, the rotation axis or rotation An abnormality diagnosis method for a rotating shaft of a rolling mill, characterized by diagnosing an abnormality occurring in a shaft and a bearing.   The detection of elastic waves by the elastic wave detecting means propagates the liquid in the liquid reservoir using a liquid reservoir in contact with a part of the rotating shaft and an acoustic emission (AE) sensor installed in contact with the liquid reservoir. The abnormality diagnosis method for a rotating shaft of a rolling mill according to claim 5, wherein an elastic wave to be detected is detected.   The detection of the elastic wave uses a disk-shaped ring attached to the rotating shaft, a liquid reservoir for storing a liquid in contact with the ring, and an acoustic emission (AE) sensor installed in contact with the liquid reservoir. The abnormality diagnosis method for a rotating shaft of a rolling mill according to claim 6.   The rotary shaft of a rolling mill according to claim 6, wherein the liquid reservoir for storing the liquid in contact with a part of the rotary shaft uses a magnetic fluid as the liquid and is attached with a magnet for holding the magnetic fluid. Abnormality diagnosis method.

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