JP7370841B2 - Deterioration determination device, deterioration determination method and program performed by the deterioration determination device - Google Patents

Description

The present disclosure relates to a deterioration determination device, a deterioration determination method performed by the deterioration determination device, and a program.

Bolts are used in a variety of equipment, such as windmills and steam turbines.
Generally, bolts tend to deteriorate (loosen) over time.
Patent Document 1 describes a related technology that detects bolt loosening by extracting the maximum value of a time-series signal for each frequency band and comparing each maximum value with a preset vibration reference value for each frequency band. A technique for determining the looseness of the material is disclosed.

Japanese Patent Application Publication No. 2000-131195

By the way, generally speaking, an inspector who inspects bolt deterioration hits the bolt with a hammer, and the inspector listens to the sound to determine the deterioration of the bolt.
In such a case, the determination of bolt deterioration depends on the experience of the inspector, and there is a high possibility that an inexperienced inspector will incorrectly determine the bolt deterioration.
Therefore, there is a need for a technology that can easily and quantitatively determine the deterioration of bolts.

The present disclosure aims to provide a deterioration determination device, a deterioration determination method performed by the deterioration determination device, and a program that can solve the above problems.

In order to solve the above problems, a deterioration determination device according to the present disclosure provides a deterioration determination device that determines deterioration of the bolt based on attenuation of the amplitude of sound generated by the bolt when vibration is applied to the bolt with a hammer. based on the ratio of the amplitude component of the sound generated by the bolt to the amplitude component of the sound surrounding the bolt, in the sound including the sound generated by the bolt and the sound surrounding the bolt. and a deterioration determination section that determines deterioration of the bolt .

A deterioration determination method performed by the deterioration determination device according to the present disclosure is a deterioration determination method performed by the deterioration determination device , and is based on the attenuation of the amplitude of the sound generated by the bolt when vibration is applied to the bolt with a hammer. Determining the deterioration of the bolt, in a sound including the sound generated by the bolt and the sound surrounding the bolt, an amplitude component of the sound generated by the bolt and an amplitude of the sound surrounding the bolt. and determining the deterioration of the bolt based on the ratio of the bolt to the component .

A program according to the present disclosure causes a computer to determine deterioration of the bolt based on attenuation of the amplitude of sound generated by the bolt when vibration is applied to the bolt with a hammer, The deterioration of the bolt is determined based on the ratio of the amplitude component of the sound generated by the bolt to the amplitude component of the sound surrounding the bolt in the sound including the sound generated by the bolt and the sound surrounding the bolt. make things happen .

According to the deterioration determination device, the deterioration determination method performed by the deterioration determination device, and the program according to the embodiment of the present disclosure, it is possible to easily and quantitatively determine the deterioration of a bolt.

FIG. 1 is a diagram illustrating an example of a configuration of a bolt deterioration determination system according to a first embodiment of the present disclosure. FIG. 3 is a diagram for explaining vibration of a bolt in the first embodiment of the present disclosure. FIG. 3 is a diagram illustrating an example of attenuation of sound amplitude in the first embodiment of the present disclosure. FIG. 3 is a diagram showing an example of the relationship between bolt fastening force and attenuation (reverberation time) in the first embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a processing flow of the bolt deterioration determination system according to the first embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a configuration of a bolt deterioration determination system according to a second embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example of a processing flow of a bolt deterioration determination system according to a second embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example of a determination result in another embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example of a determination result in another embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example of a determination result in another embodiment of the present disclosure. FIG. 1 is a schematic block diagram showing the configuration of a computer according to at least one embodiment.

<First embodiment>
Hereinafter, embodiments will be described in detail with reference to the drawings.
(Configuration of bolt deterioration determination system)
The configuration of the bolt deterioration determination system 1 according to the first embodiment of the present disclosure will be described.
The bolt deterioration determination system 1 is a system that determines the deterioration (looseness) of fastened bolts. The bolt deterioration determination system 1 includes a hammer 10, a sound measuring device 20, and a deterioration determination device 30, as shown in FIG.

The hammer 10 gives vibration by hitting the bolt. The sound generated by the bolt at this time is a sound whose main component is the natural frequency component of the bolt.

The sound measuring device 20 measures sound including the sound generated by the bolt. The sound measured by the sound measuring device 20 is recorded in the deterioration determining device 30.

The deterioration determination device 30 is a device that determines the deterioration of a bolt based on the sound generated by the bolt among the sounds measured by the sound measuring instrument 20.
The deterioration determination device 30 includes a storage section 301, a bandpass filter 302, and a deterioration determination section 303, as shown in FIG.

The storage unit 301 stores various information necessary for processing performed by the deterioration determination device 30. For example, the storage unit 301 stores data on the sound generated by the bolt among the sounds measured by the sound measuring instrument 20.

The bandpass filter 302 is a filter that passes sound of frequency components in the natural frequency band of the bolt.
For example, the sound measured by the sound measuring device 20 when a bolt is vibrated by the hammer 10 is filtered by the bandpass filter 302, and a sound whose main component is the sound generated by the bolt is output. do.

The deterioration determination unit 303 converts the sound measured by the sound measuring device 20 into a sound after passing through the band pass filter 302, that is, the sound generated by the bolt when vibration is applied to the bolt by the hammer 10, as the main component. The deterioration of the bolt is determined based on the sound.
Specifically, the deterioration determination unit 303 determines the deterioration of the bolt based on the time attenuation of the amplitude of the sound whose main component is the sound generated by the bolt.

This determination by the deterioration determination unit 303 is based on the following idea.
The sound generated by the bolt when vibrated by the hammer 10 is such that if the bolt is loose, the bolt itself vibrates more as it moves away from the base of the bolt, as shown in FIG. This vibration of the bolt itself increases as the bolt becomes looser. Therefore, as the bolt becomes looser, the energy for the bolt to vibrate is converted into frictional heat, and as a result, the amplitude of the sound generated by the bolt decays faster.
Paying attention to this, the deterioration determination unit 303 determines the attenuation of the amplitude of the sound generated by the bolt, for example, the time it takes for the amplitude of the sound to decay to a predetermined amplitude when the bolt is vibrated by the hammer 10 (for example, The bolt is determined to be deteriorated (loose) if the time required for the sound generated by the bolt to become one-tenth of the initial amplitude) is shorter than the set time.

Figure 3 shows the attenuation of sound when vibration is applied by hammer 10 with the bolt fully tightened to a specified torque, and the attenuation of sound when vibration is applied by hammer 10 with the bolt loosened. FIG. 3 is a diagram showing a comparison of attenuation.
Part (a) in FIG. 3 shows the sound produced when vibration is applied by the hammer 10 with the bolt fully fastened with a specified torque. Moreover, the part (b) in FIG. 3 shows the sound produced when vibration is applied by the hammer 10 to the bolt in a loosened state. Moreover, the upper part of the part (a) and the part (b) in FIG. 3 shows the sound measured by the sound measuring device 20. In addition, the lower portions of parts (a) and (b) in FIG. Indicates the main component sound.
As can be seen from Figure 3, the sound produced when the hammer 10 vibrates with the bolt fully tightened to the specified torque is greater than the sound generated when the hammer 10 vibrates with the bolt loosened. If the sound decays quickly.
In other words, FIG. 3 shows that the method of determination by the deterioration determination unit 303 is correct.

FIG. 4 is a diagram showing the attenuation of sound when vibration is applied by the hammer 10 with bolts fastened with various torques.
As can be seen from FIG. 4, when the bolt is tightened with 50% or more of the specified torque, there is no significant difference in the reverberation time of the sound when vibration is applied by the hammer 10. This means that when the bolts are tightened to 50% or more of the specified torque, there is no significant difference in the way the sound is attenuated.
On the other hand, when the bolt is tightened with 10% or less of the specified torque, the reverberation time when vibration is applied by the hammer 10 is the reverberation time when the bolt is tightened with 50% or more of the specified torque. It is clearly shorter than . This means that if the bolt is tightened with less than 10 percent of the specified torque, there will be a noticeable sound attenuation.
In other words, FIG. 4 shows that the method of determination by the deterioration determination unit 303 is correct.

(Processing performed by the bolt deterioration determination system)
Next, processing of the bolt deterioration determination system 1 according to the first embodiment of the present disclosure will be described.
Here, the processing flow of the bolt deterioration determination system 1 shown in FIG. 5 will be described.

A person in charge of determining the deterioration of the bolt hits the bolt with a hammer 10 to vibrate it. Bolts generate sound.
The sound measuring device 20 measures the sound around the bolt when the bolt generates sound (step S1). The sound data measured by the sound measuring device 20 is written into the storage unit 301 of the deterioration determining device 30.
The bandpass filter 302 passes the data of the sound around the bolt stored in the storage unit 301. The bandpass filter 302 outputs a sound whose main component is the sound generated by the bolt.
The deterioration determination unit 303 acquires the sound whose main component is the sound generated by the bolt, which is output by the bandpass filter 302 (step S2).
The deterioration determination unit 303 determines the deterioration of the bolt based on the sound whose main component is the sound generated by the bolt (step S3).

(Actions and effects of the bolt deterioration determination system)
The bolt deterioration determination system 1 according to the first embodiment of the present disclosure has been described above.
In the deterioration determination device 30 according to the first embodiment of the present disclosure, the deterioration determination unit 303 determines the deterioration of the bolt based on the attenuation of the amplitude of the sound generated by the bolt when vibration is applied to the bolt by the hammer 10. .

With this deterioration determination device 30, it is possible to determine the deterioration (looseness) of a bolt using a quantitative physical quantity called the amplitude of the sound generated by the bolt, with a simple configuration with a small number of components. In other words, the deterioration determination device 30 can easily and quantitatively determine the deterioration of the bolt.

<Second embodiment>
(Configuration of bolt deterioration determination system)
The configuration of a bolt deterioration determination system 1 according to a second embodiment of the present disclosure will be described.
A bolt deterioration determination system according to a second embodiment of the present disclosure includes a hammer 10, a sound measuring device 20, and a deterioration determination device 30, as shown in FIG.

The deterioration determination device 30 is a device that determines the deterioration of a bolt based on the sound generated by the bolt among the sounds measured by the sound measuring instrument 20.
The deterioration determination device 30 includes a storage section 301 and a deterioration determination section 303, as shown in FIG.

The deterioration determining unit 303 determines the deterioration of the bolt based on the sound measured by the sound measuring device 20.
Specifically, the deterioration determination unit 303 determines, based on the ratio of the amplitude component of the sound generated by the bolt and the amplitude component of the sound other than the sound generated by the bolt, in the sound measured by the sound measuring instrument 20, Determine bolt deterioration.

This determination by the deterioration determination unit 303 is based on the following idea.
As shown in FIG. 3, the amplitude component of the sound generated by the bolt in the sound measured by the sound measuring device 20 is as shown in FIG. (if the bolt is tightened to 50 percent or more of the specified torque) than if the bolt is not deteriorated (for example, if the bolt is tightened to 50 percent or more of the specified torque).
On the other hand, amplitude components other than the sound generated by the bolt are sounds around the bolt, and can be considered to be approximately constant.
In such a case, the amplitude component of the sound generated by the bolt in the sound measured by the sound measuring device 20 and the component of the amplitude of the sound generated by the bolt, depending on whether the bolt has deteriorated or not. There should be a clear difference in the ratio with amplitude components other than sound.
Focusing on this, the deterioration determination unit 303 determines that the bolt has deteriorated (loose) when the amplitude component of the sound generated by the bolt in the sound measured by the sound measuring device 20 is lower than a predetermined ratio. It is determined that there is a

(Processing performed by the bolt deterioration determination system)
Next, processing of the bolt deterioration determination system 1 according to the second embodiment of the present disclosure will be described.
Here, the processing flow of the bolt deterioration determination system 1 shown in FIG. 7 will be described.

A person in charge of determining the deterioration of the bolt hits the bolt with a hammer 10 to vibrate it. Bolts generate sound.
The sound measuring instrument 20 measures the sound around the bolt when the bolt generates sound (step S11). The sound data measured by the sound measuring device 20 is written into the storage unit 301 of the deterioration determining device 30.
The deterioration determining unit 303 determines whether the ratio of the amplitude component of the sound generated by the bolt in the sound measured by the sound measuring instrument 20 is equal to or less than a set ratio (step S12).
If the deterioration determination unit 303 determines that the ratio of the amplitude component of the sound generated by the bolt in the sound measured by the sound measuring device 20 is equal to or less than the set ratio (YES in step S12), the deterioration determination unit 303 determines that the bolt has deteriorated. It is determined that there is one (step S13).
Further, if the deterioration determining unit 303 determines that the ratio of the amplitude component of the sound generated by the bolt in the sound measured by the sound measuring instrument 20 exceeds the set ratio (NO in step S12), the bolt is It is determined that there is no deterioration (step S14).

(Actions and effects of the bolt deterioration determination system)
The bolt deterioration determination system 1 according to the second embodiment of the present disclosure has been described above.
In the deterioration determination device 30 according to the second embodiment of the present disclosure, the deterioration determination unit 303 detects the amplitude component of the sound generated by the bolt and the surroundings of the bolt in the sound including the sound generated by the bolt and the surrounding sound of the bolt. The deterioration of the bolt is determined based on the ratio between the sound amplitude component and the sound amplitude component.

With this deterioration determination device 30, it is possible to determine the deterioration (looseness) of a bolt using a quantitative physical quantity called the amplitude of the sound generated by the bolt, with a simple configuration having a smaller number of configurations (that is, without the band-pass filter 302). I can do it. In other words, the deterioration determination device 30 can easily and quantitatively determine the deterioration of the bolt.

Note that in another embodiment of the present disclosure, the hammer 10 may be a hammer equipped with a load sensor that measures the force of hitting the bolt at a location where the bolt is hit. When such a hammer 10 is used, the amplitude of the sound generated by the bolt may be normalized by the magnitude of the measured hitting force. The deterioration determination unit 303 may perform the same determination as the deterioration determination unit 303 according to the first and second embodiments of the present disclosure, using the normalized amplitude of the sound generated by the bolt. .

Note that in another embodiment of the present disclosure, the deterioration determining unit 303 determines whether the bolt is out of a predetermined range set based on past history when determining the deterioration of the same bolt over time. It may be determined that it has deteriorated.

Note that in another embodiment of the present disclosure, when deterioration is determined over time for multiple bolts of the same type, the deterioration determination unit 303 performs statistical processing based on past history to determine whether the bolt has deteriorated. It may also be determined that the
For example, as shown in FIG. 8, the deterioration determination unit 303 may determine that the bolt has deteriorated based on comparison with the previous determination result.

Note that in another embodiment of the present disclosure, the deterioration determination unit 303 may determine that the bolt has deteriorated based on the current determination results for a plurality of bolts of the same type.
For example, as shown in FIG. 9, the deterioration determination unit 303 may determine that a bolt has deteriorated based on a comparison of the current determination results for a plurality of bolts.

Note that in another embodiment of the present disclosure, the deterioration determination unit 303 may determine that the bolt has deteriorated based on the current determination results for multiple types of bolts.
For example, as shown in FIG. 10, the deterioration determination unit 303 sets a threshold value for each of multiple types of bolts, and determines that the bolt has deteriorated based on whether the determination result exceeds the threshold value. It may be something to judge.

Note that FIGS. 8 to 10 are examples in which the determination result by the deterioration determination unit 303 is the reverberation time. However, in another embodiment of the present disclosure, the determination result by the deterioration determination unit 303 is not limited to the reverberation time. For example, in another embodiment of the present disclosure, the determination result by the deterioration determining unit 303 is that the bolt generates a sound including the sound generated by the bolt and the surrounding sound of the bolt shown in the second embodiment of the present disclosure. It may be the ratio of the amplitude component of the sound caused by the bolt to the amplitude component of the sound surrounding the bolt.

Note that the order of the processing in the embodiment of the present disclosure may be changed as long as appropriate processing is performed.

The storage unit 301 and storage devices (including registers and latches) in the embodiment of the present disclosure may be provided anywhere as long as appropriate information is transmitted and received. Further, each of the storage unit 301 and the storage device may exist in plurality and store data in a distributed manner within a range where appropriate information is transmitted and received.

Although the embodiment of the present disclosure has been described, the above-described deterioration determination device 30 and other arithmetic devices may include a computer system therein. The above-described processing steps are stored in a computer-readable recording medium in the form of a program, and the above-mentioned processing is performed by reading and executing this program by the computer. A specific example of a computer is shown below.
FIG. 11 is a schematic block diagram showing the configuration of a computer according to at least one embodiment.
The computer 5 includes a CPU 6, a main memory 7, a storage 8, and an interface 9, as shown in FIG.
For example, each of the above-mentioned deterioration determination device 30 and other arithmetic devices is implemented in the computer 5. The operations of each processing section described above are stored in the storage 8 in the form of a program. The CPU 6 reads the program from the storage 8, expands it to the main memory 7, and executes the above processing according to the program. Further, the CPU 6 reserves storage areas corresponding to each of the above-mentioned storage units in the main memory 7 according to the program.

Examples of the storage 8 include HDD (Hard Disk Drive), SSD (Solid State Drive), magnetic disk, magneto-optical disk, CD-ROM (Compact Disc Read Only Memory), and DVD-ROM (Digital Versatile). (Disc Read Only Memory) , semiconductor memory, etc. Storage 8 may be an internal medium directly connected to the bus of computer 5, or may be an external medium connected to computer 5 via interface 9 or a communication line. Further, when this program is distributed to the computer 5 via a communication line, the computer 5 that receives the distribution may develop the program in the main memory 7 and execute the above processing. In at least one embodiment, storage 8 is a non-transitory tangible storage medium.

Further, the program may realize some of the functions described above. Furthermore, the program may be a file that can realize the above-described functions in combination with a program already recorded in the computer system, a so-called difference file (difference program).

Although several embodiments of the disclosure have been described, these embodiments are examples and do not limit the scope of the disclosure. Various additions, various omissions, various substitutions, and various changes may be made to these embodiments without departing from the gist of the disclosure.

<Additional notes>
The deterioration determination device 30 and the control method and program performed by the deterioration determination device 30 described in each embodiment of the present disclosure can be understood, for example, as follows.

(1) The deterioration determination device (30) according to the first aspect determines the deterioration of the bolt based on the attenuation of the amplitude of the sound generated by the bolt when vibration is applied to the bolt by the hammer (10). A deterioration determination unit (303) is provided.

With this deterioration determination device (30), it is possible to determine the deterioration (looseness) of a bolt using a quantitative physical quantity called the amplitude of the sound generated by the bolt, with a simple configuration with a small number of components. In other words, the deterioration determination device (30) can easily and quantitatively determine the deterioration of the bolt.

(2) The deterioration determination device (30) according to the second aspect is the deterioration determination device (30) of (1), and includes a bandpass filter (30) that selectively passes the sound in the natural frequency band of the bolt. 302), the deterioration determination unit (303) determines the deterioration of the bolt based on the attenuation of the amplitude of the sound generated by the bolt after passing it through the band pass filter (302). It may be something to judge.

With this deterioration determining device (30), it is possible to determine the deterioration of the bolt based only on a quantitative physical quantity, that is, the amplitude of the sound generated by the bolt.

(3) A deterioration determination device (30) according to a third aspect is the deterioration determination device (30) of (1), in which the deterioration determination unit (303) is configured to detect the sound generated by the bolt and the sound generated by the bolt. The deterioration of the bolt may be determined based on a ratio of an amplitude component of a sound generated by the bolt to an amplitude component of a sound surrounding the bolt in sounds including surrounding sounds. .

With this deterioration determination device (30), it is possible to determine the deterioration of a bolt with a simpler configuration without a bandpass filter (302).

(4) The deterioration determination device (30) according to the fourth aspect is any one of the deterioration determination devices (30) of (1) to (3), and the deterioration determination unit (303) The attenuation of the amplitude of the sound generated by each of the plurality of bolts may be compared, and the deterioration of the bolt may be determined based on the comparison result.

With this deterioration determining device (30), it is possible to objectively determine the deterioration of the bolt by comparing it with other data.

(5) The deterioration determination device (30) according to the fifth aspect is any one of the deterioration determination devices (30) of (1) to (3), and the deterioration determination section (303) is the same deterioration determination device (30). Regarding the bolt, the attenuation of the sound amplitude at one time may be compared with the attenuation of the sound at a time after the one time, and the deterioration of the bolt may be determined based on the comparison result. .

With this deterioration determination device (30), it is possible to objectively determine the deterioration of the bolt by comparing it with other data.

(6) The deterioration determination method performed by the deterioration determination device (30) according to the sixth aspect is a deterioration determination method performed by the deterioration determination device (30), in which a bolt is vibrated by a hammer (10). determining deterioration of the bolt based on attenuation of the amplitude of sound generated by the bolt.

The deterioration determination method carried out by this deterioration determination device (30) allows the deterioration (looseness) of a bolt to be determined using a quantitative physical quantity called the amplitude of the sound generated by the bolt, with a simple configuration with few components. In other words, by the deterioration determination method performed by the deterioration determination device (30), it is possible to determine the deterioration of the bolt in a simple and quantitative manner.

(7) The program according to the seventh aspect causes the computer to determine the deterioration of the bolt based on the attenuation of the amplitude of the sound generated by the bolt when vibration is applied to the bolt with a hammer. let

With this program, it is possible to determine the deterioration (looseness) of a bolt using a quantitative physical quantity called the amplitude of the sound generated by the bolt, using a simple configuration with few components. In other words, the program can easily and quantitatively determine the deterioration of the bolt.

1...Bolt deterioration determination system 5...Computer 6...CPU
7...Main memory 8...Storage 9...Interface 10...Hammer 20...Sound measuring device 30...Deterioration determination device 301...Storage section 302...Band pass filter 303...・Deterioration judgment part

Claims (6)

a deterioration determination unit that determines deterioration of the bolt based on attenuation of the amplitude of sound generated by the bolt when vibration is applied to the bolt with a hammer, a deterioration determination unit that determines deterioration of the bolt based on a ratio of an amplitude component of a sound generated by the bolt to an amplitude component of a sound surrounding the bolt, in a sound including a sound;
A deterioration determination device comprising: a bandpass filter that selectively passes sound in the natural frequency band of the bolt;
Equipped with
The deterioration determination section includes:
Determining the deterioration of the bolt based on the attenuation of the amplitude of the sound generated by the bolt after passing it through the band-pass filter.
The deterioration determination device according to claim 1. The deterioration determination section includes:
Comparing the attenuation of the amplitude of the sound generated by each of a plurality of bolts of the same type, and determining the deterioration of the bolt based on the comparison result.
The deterioration determination device according to claim 1 or 2 . The deterioration determination section includes:
Comparing the attenuation of the sound amplitude at one time with the attenuation of the sound at a time after the one time for the same bolt, and determining the deterioration of the bolt based on the comparison result.
The deterioration determination device according to claim 1 or 2 . A deterioration determination method performed by a deterioration determination device, the method comprising:
Determining the deterioration of the bolt based on the attenuation of the amplitude of the sound generated by the bolt when vibration is applied to the bolt with a hammer , and determining the difference between the sound generated by the bolt and the sound surrounding the bolt. determining the deterioration of the bolt based on the ratio of the amplitude component of the sound generated by the bolt to the amplitude component of the sound surrounding the bolt;
A deterioration determination method performed by a deterioration determination device including: to the computer,
Determining the deterioration of the bolt based on the attenuation of the amplitude of the sound generated by the bolt when vibration is applied to the bolt with a hammer , and determining the difference between the sound generated by the bolt and the sound surrounding the bolt. determining the deterioration of the bolt based on the ratio of the amplitude component of the sound generated by the bolt to the amplitude component of the sound surrounding the bolt;
A program to run.

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