JP3090997B2 - Abnormal diagnostic device for rotating parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for diagnosing abnormalities of a rotating component using acoustic emission (AE).

[0002]

2. Description of the Related Art Conventionally, as a device for diagnosing abnormality of a rotating component using an AE, a vibration generated by the rotating component is detected by first and second AE sensors, and within a predetermined time, an abnormality determining means is detected. Is the AE signal from the first AE sensor and the second
When both of the AE signals from the AE sensor are received, the abnormality determination unit determines the abnormality based on a time difference between the time when the AE signal is received from the first AE sensor and the time when the AE signal is received from the second AE sensor. In some cases, the location where an abnormality has occurred in a rotating component is determined.

[0003]

However, in the above-described conventional abnormality diagnosis apparatus, the AE reaches the AE sensor closer to the AE generation source of the rotating component, while the AE is reduced by the AE attenuation in the AE transmission path. A far from
When the AE does not reach the E sensor, the abnormality determination unit receives only the AE signal from one of the AE sensors. Therefore, in this case, the abnormality determination means is provided with one of the AEs.
The AE signal is received from the two AE sensors because the AE signal is received from the sensor but not the AE signal from the other AE sensor.
This makes it impossible to perform a determination operation of determining a location where an abnormality has occurred in a rotating component based on a signal reception time difference. In other words, the above-described conventional abnormality diagnosis apparatus has a problem in that when only one of the AE sensors generates an AE signal, it is not possible to determine the location where the abnormality has occurred in the rotating component.

Accordingly, an object of the present invention is to provide an apparatus for diagnosing abnormality of a rotating component which can determine a location where an abnormality has occurred in a rotating component even when only one of the two AE sensors generates an AE signal. Is to do.

[0005]

In order to achieve the above object, an apparatus for diagnosing abnormality of a rotating part according to the present invention comprises a first AE sensor and a second AE sensor for detecting an AE generated by the rotating part and outputting an AE signal. Within the predetermined time, the first A
When both the AE signal from the E sensor and the AE signal from the second AE sensor are received, the A signal from the first AE sensor is received.
First abnormality determining means for determining a location where an abnormality has occurred in a rotary component based on a difference between a time at which an E signal is received and a time at which an AE signal is received from the second AE sensor; When only the AE signal from the 1AE sensor is received, it is determined that the abnormality occurrence position of the rotating component is near the first AE sensor, while the second AE is detected within the predetermined time.
A second abnormality determining means is provided for determining that the abnormality occurrence position of the rotary component is near the second AE sensor when receiving only the AE signal from the sensor.

[0006]

According to the above configuration, for example, a circuit illustrated in FIG. 5 can be configured, and the second abnormality determining means is configured to rotate the rotary component when only the AE signal from the first AE sensor is received within the predetermined time. Is determined to be near the first AE sensor, while the second AE is detected within the predetermined time.
When only the detection signal from the sensor is received, it is determined that the abnormality occurrence position of the rotating component is in the vicinity of the second AE sensor. Therefore, only one AE sensor of the first and second AE sensors is used. Even when the AE signal is generated, it is possible to determine the location where the rotary component is abnormal.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an apparatus for diagnosing abnormality of a rotating part according to the present invention.

FIG. 1 is a block diagram showing an embodiment of an apparatus for diagnosing abnormality of a rotating part according to the present invention, wherein 1 is an AE sensor as a first AE sensor, and 2 is an AE as a second AE sensor.
Sensors 3, 4 are preamplifiers, 5, 6 are band-pass filters for AE signal selection, 7, 8 are main amplifiers, 9, 10 are envelope detection circuits, 11, 12 are reference value setting circuits, 13, 1
4 is a comparator. Reference numerals 15 and 17 denote delay circuits that receive the output signal of the comparator 13, 16 and 18 denote delay circuits that receive the output signal of the comparator 14, 19 denotes an inverter that receives the output signal of the comparator 14, and 20 denotes a Inverters that receive output signals, 21 and 22 are latch circuits, 23, 24,
25 is an AND circuit, 26, 27, 28 are delay circuits, 29,
Numerals 30 and 31 are counters constituting the determination result output device. The delay circuits 15, 16, 17, 18 and the inverter 1
9, 20, latch circuits 21, 22 and AND circuits 23, 24,
25 and the delay circuits 26, 27, 28 constitute first abnormality determination means. The delay circuits 15 and 18, the inverters 19 and 20, the latch circuits 21 and 22, and the AND circuit 2
3, 25 and the delay circuits 26, 27, 28 constitute second abnormality determination means.

The AE sensors 1 and 2 detect an AE from a rotating part such as an inner ring of a bearing, and output an AE signal indicating the magnitude of the AE. AE sensors 1 and 2 above
Is amplified by the preamplifiers 3 and 4, the AE signal in the band of, for example, 200 kHz to 500 kHz is passed through the band pass filters 5 and 6 for AE signal selection, the noise is removed, and abnormalities of the rotating parts are caused. The resulting abnormal AE signal is extracted. The abnormal AE signals extracted by the band-pass filters 5 and 6 are further amplified by main amplifiers 7 and 8, input to envelope detection circuits 9 and 10, and envelope-detected.

The abnormal AE signals detected by the envelope detection circuits 9 and 10 are detected by the comparators 13 and 1 respectively.
4 is compared with a predetermined diagnostic reference value output from the reference value setting circuits 11 and 12. The comparators 13 and 14 output a detection pulse signal when the abnormal AE signal exceeds the reference value. That is, the comparators 13 and 14 pulse the abnormal AE signal exceeding the reference value.

The signal processing operation of the pulsed abnormal AE signal after the comparators 13 and 14 will be described with reference to the time charts of FIGS. 2, 3 and 4.

First, as shown in FIG. 2A, the time when the AE sensor 2 outputs the AE signal Y is determined by the time when the AE sensor 1 outputs the AE signal.
An operation in the case where a predetermined time has elapsed from the time when the signal X was output will be described.

As shown in FIG. 2B, the delay circuit 15 receiving the pulse signal of the AE signal X from the comparator 13 delays the AE signal X by a predetermined delay time T1 from the AE signal X. The pulse signal P1 having a width of T2 is output. On the other hand, the latch circuit 21 receives the pulse signal of the AE signal Y from the comparator 14 via the inverter 19, and changes from the H level to the L level at the time when the AE sensor 2 outputs the AE signal Y, At the falling time of the pulse signal P1 output from the delay circuit 15, a pulse signal P2 that changes from L level to H level is output. And the AND circuit 23
Are the pulse signal P1 of the delay circuit 15 and the latch circuit 2
1 and the pulse signal P2 to calculate the logical product.
3 is output.

As shown in FIG. 2B, A of the AE sensor 2
When the generation time of the E signal Y is a time that is longer than the generation time of the AE signal X of the AE sensor 1 by a predetermined delay time T1 or more, the AND circuit 23 outputs the pulse signal P3. After shaping the pulse signal P3, the delay circuit 26 outputs the shaped pulse signal P3 to a counter circuit 29 that counts the number of times an abnormality has occurred in the rotating component near the AE sensor 1. The counter circuit 29
In response to the pulse signal P3, the count number indicating the number of times an abnormality has occurred in the rotating component near the AE sensor 1 is increased by one.

On the other hand, as shown in FIG.
7 outputs a pulse signal P4 having a pulse width T3 at the generation time of the AE signal X. Further, the delay circuit 16 outputs the AE signal Y
, A pulse signal P5 having a pulse width T4 is output. Therefore, as shown in FIG. 2A, the difference between the generation time of the AE signal X and the generation time of the AE signal Y is the pulse width T3.
If it is larger, the AND circuit 24 does not output a pulse signal.

As shown in FIG. 2D, the AE signal X
From the comparator 13 to the inverter 20
The latch circuit 22 which has received the AE signal X changes from the H level to the L level at the generation time of the AE signal X, and the delay circuit 1
At the falling time of the pulse P7 output by the pulse No. 8, a pulse signal P6 which changes from the L level to the H level is output. Also, A
The delay circuit 18 receiving the pulse signal of the E signal Y from the comparator 14 delays the generation time of the AE signal Y by a predetermined time T5 and outputs a pulse signal P7 having a pulse width T6. In FIG. 2, the generation time of the AE signal X is
Since the time before the AE signal Y is generated, the pulse signal P6 is at the L level while the pulse signal P7 is at the H level. Therefore, AND circuit 25 does not output a pulse signal.

Next, as shown in FIG. 3A, it is assumed that only the AE sensor 1 outputs the AE signal X within the period of outputting the predetermined time T1 and the pulse width T2 in FIG. 2A. The operation will be described.

The delay circuit 15, which receives a pulse signal of the AE signal X from the AE sensor 1 from the comparator 13,
A pulse signal P1 which is the same as the pulse signal P1 shown in FIG. On the other hand, since the latch circuit 21 does not receive the pulse signal from the comparator 14, it keeps outputting the H level signal. Therefore, the AND circuit 23 outputs a pulse signal P8 having the same waveform as the pulse signal P1. Counter circuit 29
Receives the pulse signal P8 via the delay circuit 26,
The count number indicating the number of times that an abnormality of a circuit component has occurred near the sensor 1 is increased by one.

Since no AE signal is generated from the AE sensor 2, no pulse signal is output from the delay circuits 18 and 16 as shown in FIGS. 3 (C) and 3 (D). Therefore, pulse signals are not output from AND circuits 24 and 25.

Next, as shown in FIG. 4A, the time when the AE sensor 1 outputs the AE signal X and the time when the AE sensor 2
The operation when the difference from the time when the signal Y is output is smaller than the delay time T1 set by the delay circuit 15 will be described.

In this case, as shown in FIG. 4B, before the delay circuit 15 outputs the pulse signal P1, the latch circuit 2
1 changes from H level to L level. Therefore,
The AND circuit 23 does not output a pulse signal. On the other hand, as shown in FIG.
The difference from the generation time of the signal Y is determined by the delay circuits 17 and 1
The pulse width T3 of the pulse signals P4 and P5 generated by the pulse No. 6
And T4, the pulse signal P5 is generated during the generation of the pulse signal P4, and the AND circuit 24 outputs the pulse signal P9. The delay circuit 27 shapes the waveform of the pulse signal P9 from the AND circuit 24, and counts the waveform-shaped pulse signal P9 in the vicinity of the center of the AE sensors 1 and 2 to determine the number of rotations in which an abnormality has occurred in the rotating component. Output to the counter 30 to be executed. The counter 30 that has received the pulse signal P9 increases the count number indicating the number of times an abnormality has occurred in the rotating component near the center of the AE sensor 1 and the AE sensor 2 by one.

2 to 4, the time when the AE sensor 1 generates the AE signal X is before the time when the AE sensor 2 generates the AE signal Y. Although the case where the AE signal Y occurs is described, when the AE signal Y occurs before the AE signal X occurs and when only the AE signal Y occurs, the signal of the AE sensor 1 system and the AE sensor 2 Since only the system signals are interchanged, the description is omitted.

As described above, according to this embodiment, when both the AE sensor 1 and the AE sensor 2 output the AE signal,
Not only (in the case of FIGS. 2 and 4), but also when only one of the AE sensor 1 and the AE sensor 2 outputs the AE signal.
In the case of FIG. 3 as well, it is possible to diagnose an abnormal portion of the rotating component.

[0024]

As is clear from the above, the abnormality diagnosis apparatus for rotating parts according to the present invention, when receiving both the AE signal from the first AE sensor and the AE signal from the second AE sensor within a predetermined time, A first abnormality determination unit configured to determine a location where an abnormality has occurred in a rotating component based on a difference between a time when an AE signal is received from the first AE sensor and a time when an AE signal is received from the second AE sensor; The first A in time
When only the AE signal from the E sensor is received, it is determined that the abnormality occurrence position of the rotating component is in the vicinity of the first AE sensor. On the other hand, when only the detection signal from the second AE sensor is received within the predetermined time, There is provided second abnormality determination means for determining that the abnormality occurrence position of the rotating component is near the second AE sensor.

Therefore, according to the present invention, not only when both the first AE sensor and the second AE sensor output the AE signal, but also when only one of the first AE sensor and the second AE sensor outputs the AE signal. It is possible to diagnose abnormal parts of rotating parts.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a rotary component abnormality diagnosis apparatus according to the present invention.

FIG. 2 is a time chart for explaining the operation of the embodiment.

FIG. 3 is a time chart for explaining the operation of the embodiment.

FIG. 4 is a time chart for explaining the operation of the embodiment.

FIG. 5 is a circuit diagram illustrating the concept of the present invention.

[Explanation of symbols]

1,2 AE sensor 3,4 Preamplifier 5,6 Bandpass filter 7,8 Main amplifier 9,10 Envelope detection circuit 11,12 Reference value setting circuit 13,14 Comparator 15,16,17,18,26,27 , 28 Delay circuit 19,20 Inverter 21,22 Latch circuit 23,24,25 AND circuit 29,30,31 Counter circuit

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 13/04 G01N 29/14

Claims (1)

(57) [Claims] An AE that detects an AE generated by a rotating component is detected.
A first AE sensor and a second AE sensor that output signals, and an AE signal from the first AE sensor when receiving both an AE signal from the first AE sensor and an AE signal from the second AE sensor within a predetermined time. Abnormality determining means for determining a location where an abnormality has occurred in a rotary component based on a difference between a time at which the AE signal is received and a time at which an AE signal is received from the second AE sensor; When only the AE signal is received from the
A second abnormality determination that determines that the abnormality occurrence location of the rotary component is near the second AE sensor when only the AE signal from the second AE sensor is received within the predetermined time while determining that the AE sensor is near the AE sensor. Means for diagnosing an abnormality of a rotating component.