JPH10185743A - Display method for leak position in specification method for leak position in pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a display method in which a leak position in a pipe can be specified precisely by a method wherein sound waves are output from the outer side from a branch cheese at the pipe and the sound waves are detected by a plurality of sound- wave detecting means. SOLUTION: A loudspeaker 9 is installed on the upstream side from a branch tee 4 at a pipe 6, and a loudspeaker 10 is installed on the downstream side from a branch tee 5. First, a white sound is output from the loudspeaker 9. The white sound from the loudspeaker 9 is measured by a microphone 7 and a microphone 8, and a sound- wave signal obtained by the microphone 7 and a sound-wave signal obtained by the microphone 8 are processed by a cross-correlation method. Then, a white sound is output from the loudspeaker 10. The white sound from the loudspeaker 10 is measured by the microphones 7, 8, and a sound-wave signal obtained by the microphone 7 and a sound-wave signal obtained by the microphone 8 are processed by a cross-correlation method. Thereby, when a relative position regarding a leak position in the section up to the branch tee 5 from the branch tee 4 is detected, the leak position can be specified, and the distance up to the leak position from the branch tee 4 or 5 can be displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak position display method in a pipe leak position specifying method.

[0002]

2. Description of the Related Art Pipings buried in soil, such as gas and water, have holes due to corrosion or the like, and objects to be transported inside the pipes may leak. In such a case, it is desirable to specify the leak position with high accuracy and to dig up and repair only the leak position.

Hitherto, as a method of specifying a leak position of a pipe, an acoustic pipe leak position specifying method has been known.
For example, a pipe leak inspection method disclosed in Japanese Patent Application Laid-Open No. Hei 5-87669 is a method of specifying a leak position in a pipe for transporting water, oil, and the like.
A sound pressure is detected at a point, and a signal of the sound pressure obtained at the two points is processed by a cross-correlation method to determine a difference in propagation time until the leaked sound wave is transmitted to the two points. This is a method of specifying a leakage position based on the information.

For example, referring to FIG. 2, a microphone 2 and a microphone 3 are attached to arbitrary two points (points A and B) on a pipe 1, and the microphones 2 and 3 use the microphones 2 and 3 to leak sound waves from a point C at a leak position. Is measured. Then, by processing the sound wave signal obtained by the microphone 2 and the sound wave signal obtained by the microphone 3 by a cross-correlation method, a difference in propagation time until the leaked sound wave is transmitted to two points is obtained. The point C, which is the leakage position, can be specified based on this.

[0005]

However, in the conventional sound wave type pipe leak position specifying method, since the distance from the two microphones attached to the pipe to the leak position can be known, the microphone mounting position with respect to the pipe is known. Depending on the case, the leak position could not be specified accurately. This will be described in detail below.

FIG. 3 is a diagram for explaining a mounting position of a microphone with respect to a pipe.

The pipe 6 is, for example, a gas pipe. The pipe branches at the branch cheeses 4 and 5 and rises to supply gas to each customer. The dominant pipe that rises from the branch cheeses 4 and 5 is not buried in the ground and is out on the ground, so it does not corrode and the microphone can be easily installed. The microphones 7 and 8 are attached to the portions that have risen after branching at the branch cheese 5, so that the branch cheese 4 and the branch cheese 5
The leak position can be specified for the portion between the two.

However, if a microphone is attached to a portion where the pipe rises from the branch cheese, the distance from the microphone to the leak position can be known, but the leak position cannot be specified accurately. This is because the pipe has flexibility at the part where the pipe rises from the branch cheese and has a complicated structure.The distance from the microphone to the branch cheese is not exactly known, and the pipe leakage position This is because the distance obtained from the microphone to the leak position cannot be accurately specified because the distance obtained from the microphone is the distance from the microphone to the leak position.

The present invention has been made in view of the above points, and even if the microphone is attached to a portion where the pipe has risen from the branch cheese so that the microphone can be easily attached, the piping can be accurately connected. An object of the present invention is to provide a leak position display method in a pipe leak position specifying method capable of specifying a leak position.

[0010]

According to the present invention, in order to attain the above object, sound wave detecting means is attached to each of the dominant pipes which have risen by branching at the branch cheeses at both ends of the pipe. In the leak position display method in the pipe leak position specifying method for specifying the leak position of the pipe based on the propagation time difference of the leaked sound wave detected in, the sound wave is output from outside the branch cheese of the pipe, the sound wave is The positional relationship between the two acoustic wave detecting means and the two branched cheeses is determined by detecting the two acoustic wave detecting means, and the positional relationship between the two branched cheeses and the leakage position is determined based on the positional relationship. To display.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a view for explaining an embodiment of a leak position display method in a pipe leak position specifying method according to the present invention.

In the present embodiment, the branch cheese 4 of the pipe 6
The speaker 9 is provided on the more upstream side, and the speaker 10 is provided on the downstream side of the branch cheese 5.

First, for example, a white sound is output from the speaker 9. The microphones 7 and 8 measure the white sound from the speaker 9, and process the sound wave signal obtained by the microphone 7 and the sound wave signal obtained by the microphone 8 by a cross-correlation method. By doing so, it is possible to determine the difference in propagation time between the time required for the white sound from the speaker 9 to reach the microphone 7 and the time required for reaching the microphone 8. The difference in the propagation time is the difference between the time when the white sound from the speaker 9 reaches the microphone 7 from the branch cheese 4 and the time when the white sound reaches the microphone 8 from the branch cheese 4. The relative position of the branch cheese 4 in the section up to can be obtained.

Next, a white sound is output from the speaker 10, for example. The microphones 7 and 8 measure the white sound from the speaker 9, and process the sound wave signal obtained by the microphone 7 and the sound wave signal obtained by the microphone 8 by a cross-correlation method. By doing so, it is possible to determine the difference in propagation time between the time required for the white sound from the speaker 10 to reach the microphone 7 and the time required for the white sound to reach the microphone 8. The difference in the propagation time is the difference between the time when the white sound from the speaker 10 reaches the microphone 7 from the branch cheese 5 and the time when the white sound reaches the microphone 8 from the branch cheese 5. The relative position of the branch cheese 5 in the section up to can be obtained.

By the way, according to the above-mentioned prior art, it is possible to obtain the relative position of the leakage position in the section from the microphone 7 to the microphone 8. Therefore, the relative position of the leakage position in the section from the microphone 7 to the microphone 8, the relative position of the branch cheese 4 in the section from the microphone 7 to the microphone 8, and the position of the branch cheese 4 from the microphone 7 to the microphone 8 are determined. By combining the relative position of the branch cheese 5 in the section, the relative position of the leakage position in the section from the branch cheese 4 to the branch cheese 5 can be specified. Since the positions of the branch cheeses 4 and 5 are known in advance, and the distance from the branch cheese 4 to the branch cheese 5 is also known, if the relative position of the leakage position in the section from the branch cheese 4 to the branch cheese 5 is known, the leakage The position can be specified, and the distance from the branch cheeses 4 and 5 to the leak position can be displayed.

[0017]

As described above, according to the present invention,
Leak position display in the pipe leak position identification method that can accurately identify the leak position of the pipe even when the microphone is attached to the part where the pipe rises from the branch cheese so that the microphone can be easily installed A method can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of a leak position display method in a pipe leak position specifying method according to the present invention.

FIG. 2 is a view showing a state in which a microphone is attached to a pipe.

FIG. 3 is a diagram illustrating a mounting position of a microphone with respect to a pipe.

[Explanation of symbols]

 1 Piping 2, 3 Microphone 4, 5 Branching Cheese 6 Piping 7, 8 Microphone 9, 10 Speaker

Claims (2)

[Claims] 1. A sound position detecting means is attached to each of the dominant pipes which are branched and risen at the branch cheeses at both ends of the pipe, and a leak position of the pipe is determined based on a propagation time difference between leaked sound waves detected by the two sound wave detecting means. In the method for displaying a leak position in the method for specifying a leak position of a pipe, a sound wave is output from outside the branch cheese of the pipe, and the two sound wave detecting means detect the sound wave by the two sound wave detecting means. A positional relationship between the two branched cheeses and the two branched cheeses, and a positional relationship between the two branched cheeses and the leaked position is determined and displayed based on the positional relationship. Display method. 2. The leak position display method according to claim 1, wherein the sound wave output from the outside of the branch cheese of the pipe is a white sound.