JP7169577B2 - LEAK DETECTION METHOD AND LEAK DETECTION DEVICE - Google Patents

Description

Article 30, Paragraph 2 of the Patent Act applies Published at JST Fair 2017 held at Tokyo Big Sight on August 31, 2017

The present invention relates to a method and apparatus for detecting the presence or absence of a leak in a pipeline through which liquid under pressure flows, and the location of the leak.

In the ground, pipelines are laid through which liquids with various pressures, including tap water, industrial water, and agricultural water, circulate. Such pipelines are connected by arranging standard-sized pipes in series and constructing a joint having a structure adapted to the liquid that flows, thereby ensuring liquid-tight connection between the pipes. . For example, in the case of pipelines for industrial water and agricultural water, watertightness is ensured by connecting pipe ends of Hume pipes via packing. Moreover, in the case of a pipeline for waterworks, watertightness is ensured by fastening the ends of cast iron pipes together with bolts via packing.

On the other hand, pipelines laid underground are subject to forces corresponding to vibrations caused by vehicles running on the road surface, forces associated with ground subsidence, the direction of laying pipelines during an earthquake, or the A force such as a directional force is always acting. These forces acting on the pipeline can then cause the joints of the pipe to separate and create gaps or cracks in the pipe walls.

If a gap in the seam or a crack in the pipe wall occurs in a pipeline through which a liquid with pressure flows, the flowing liquid will leak into the ground, resulting in problems corresponding to the properties of the flowing liquid. For example, in the case of industrial water, agricultural water, or clean water, these waters are subjected to water treatment according to their respective purposes, and water leakage causes waste of treatment costs. In addition, water leakage from the pipeline may weaken the ground around the pipeline or change the soil.

In order to deal with the above-mentioned problems, it is carried out to investigate the presence or absence of water leakage in pipelines laid underground and the location of the water leakage. Such investigations are generally carried out by detecting audible sounds generated by water leakage from pipelines. That is, the audible sound produced when liquid under pressure is jetted through gaps formed at joints between pipes or cracks formed in pipe walls is detected by valves such as sluice valves and faucets constructed in pipes. The presence or absence of water leakage in the pipeline to be investigated and the location of the water leakage can be determined by listening through a sound listening rod that is in contact with a plug such as the is investigating.

In order to detect the presence and location of leaks in such pipelines, a patent has been obtained for the "leak detection device and leak detection method" described in Patent Document 1. In this technique, a moving body equipped with a sound collecting member, a recording member, and a member for detecting the position in the pipeline is moved in the pipeline through which the pressure fluid flows, and when the fluid flows through the pipeline, The leak position is detected by collecting and recording the sound generated in the space and detecting the position.

Japanese Patent No. 5583994

In the invention described in Patent Literature 1, the moving body moves along the bottom of the pipe along with the flow of the pressure fluid, and collects and records sound during this moving process. As a result, the outer peripheral surface of the moving body comes into contact with the bottom surface of the pipeline, generating an impact sound. In addition, the moving speed of the moving body becomes slower than the flow speed of the fluid, and rubbing noise is generated when the fluid passes through the outer peripheral surface of the moving body. Any sound generated in this manner is collected by a sound collecting member mounted on the moving body and recorded on a recording member.

As described above, the impact sound generated by the moving body coming into contact with the bottom surface of the pipeline and the friction sound generated by the difference between the moving speed of the moving body and the flow speed of the fluid are both noises for leak detection. . Therefore, it is necessary to separate the noise and the leaked sound from the recorded sound, and this separation work requires a high degree of skill.

Also, if the sound generated from the leaking part interferes with the wall surface of the pipe, the sound data of the recorded sound will be curved without a noticeable peak, making it difficult to accurately detect the leaking position. There is

SUMMARY OF THE INVENTION An object of the present invention is to provide a leak detection method capable of more accurately detecting the presence or absence of a leak and the location of the leak in a pipeline through which liquid under pressure flows, and a leak detection apparatus for carrying out this method. That's what it is.

In order to solve the above-described problems, a leak detection method according to the present invention is a leak detection method for detecting a leak in a pipeline through which a liquid under pressure flows. The liquid is collected by a first sound collecting member oriented upstream and arranged upstream in the moving direction, and a second sound collecting member oriented downstream and separated downstream from the first sound collecting member. A moving body configured to collect and record sound transmitted through the pipe and to detect the position of movement in the pipe is placed along substantially the center of the pipe along with the liquid flowing in the pipe. , and two sound data of the sound transmitted through the liquid recorded in the moving process of the moving body and the moving position in the pipeline detected by the moving body, It is characterized by detecting the leak position.

Further, a leakage detection device according to the present invention is a leakage detection device for detecting leakage in a pipeline through which liquid having pressure flows, wherein the outer diameter is smaller than the inner diameter of the pipeline, and A first sound collecting member for collecting sound transmitted through the liquid when the liquid flows through the pipe, and a first recording member for recording the sound collected by the first sound collecting member. and a second sound collecting member which is spaced apart from the first sound collecting member and collects sound transmitted through the liquid when the liquid flows through the pipe, and the second sound collecting member. A moving body in which a second recording member for recording the sound collected by the sound member and a position detection member for detecting the movement position in the pipe are arranged and which moves together with the liquid inside the pipe. have

In particular, the first sound collecting member is arranged on the upstream side in the moving direction of the moving body and has directivity toward the upstream side in the moving direction, and the second sound collecting member is arranged on the downstream side in the moving direction. has directivity toward the downstream side in the moving direction.

Moreover, in the leakage detection device described above , it is preferable that the moving body is formed as a cylindrical body.

Further, in any of the leakage detection devices described above, the member for detecting the position of movement of the moving body in the pipeline comprises a gyro and an acceleration sensor mounted on the moving body. preferably.

Further, in any of the leak detection devices described above, a member for detecting a position of movement in the pipeline of the moving body is mounted on the moving body and generates a pulse signal corresponding to a reference clock. and a receiving member that is provided outside the pipe line to detect leakage and receives the pulse signal transmitted from the transmitting member in synchronism with the clock of the transmitting member. The movement position of the moving body in the pipeline is determined by the time difference between the receiving member receiving the pulse signal transmitted from the transmitting member moving inside the channel and the receiving member receiving the pulse signal transmitted from the transmitting member. is preferably configured to detect

A leak detection method according to the present invention is a method for detecting a leak in a pipeline through which liquid having pressure (hereinafter simply referred to as "liquid") flows. In this water leakage detection method, the moving body is moved along substantially the center of the pipe along with the flowing liquid, and the sound transmitted through the liquid is collected and recorded at two points separated from each other. Detects the movement position inside. Then, by matching the two sound data of the recorded sound with the position of the moving object, the presence and position of water leakage can be detected.

In particular, by collecting and recording the sound transmitted through the liquid at two separate locations, the recorded sound data will have peaks corresponding to leaks. That is, even if the sound produced by the leak interferes with the walls of the conduit and does not form a distinct apex, the apex as a trend can be recognized. Therefore, by associating the two sound data with the position of the moving object, the position of the water leak can be accurately detected.

In addition, since the moving body moves along substantially the center of the pipeline, the moving body does not come into contact with the wall surface including the bottom of the pipeline. For this reason, there is no fear of generating noise due to contact with the pipe wall accompanying the movement of the moving body, and sound generated in one of the pipes interferes with other parts of the pipe, resulting in noise. There is no fear of occurrence. Therefore, it is possible to record only the sound caused by water leakage, and it is possible to realize accurate water leakage detection.

A leakage detection device according to the present invention includes a moving body in which a first sound collection member and a first recording member, a second sound collection member and a second recording member, and a position detection member are arranged. . Therefore, the leakage can be detected by moving the moving body together with the liquid along substantially the center of the pipeline.

In any of the leak detection devices described above, the first sound collecting member has directivity toward the moving direction upstream side of the moving body, and the second sound collecting member has directivity toward the moving direction downstream side of the moving body. If it has directivity, it is possible to detect the water leakage position more clearly. That is, since the directivity of the first sound collecting member and the directivity of the second sound collecting member are diametrically opposed to the moving direction of the moving body, the sound data of the sound collected by both sound collecting members have diametrically opposed curves. Present. Therefore, by correlating each sound data with the moving position of the moving body, the presence or absence of water leakage and the position of water leakage can be detected more accurately.

Further, in any of the leak detection devices described above, when the position detection member for detecting the moving position of the moving body is configured to have a gyro and an acceleration sensor mounted on the moving body, It is possible to detect its own moving position in the process of moving inside the pipe along with the liquid.

Further, in any of the leak detection devices described above, a position detection member for detecting a moving position of the moving body is provided on the moving body and a transmitting member for transmitting a pulse signal is provided outside the pipeline. and a receiving member for receiving the pulse signal transmitted from the transmitting member, the receiving member receives the pulse signal transmitted from the transmitting member moving inside the pipeline, and the pulse signal transmitted from the transmitting member is received by the receiving member. It is possible to detect the moving position of the moving body in the pipeline from the time difference when it is received by the receiving member.

Therefore, in any of the leakage detection devices described above, the sound generated in the pipeline and transmitted through the liquid is collected by the sound collecting member in the process in which the moving body moves along substantially the center of the pipeline, The collected sound can be recorded on the recording member. Furthermore, the position detection member can detect the movement position of the moving body in the pipeline. Therefore, by matching the sound recorded by collecting the moving body from the pipeline with the detected movement position in the pipeline, the presence and position of water leakage can be detected.

It is a schematic diagram explaining the leak detection method which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram explaining the structure of the leakage detection apparatus which concerns on 1st Example. FIG. 4 is a diagram comparing sound data of sounds collected by a first sound collecting member and a second sound collecting member; It is a figure explaining the movement state of the leak detection apparatus which concerns on 1st Example. It is a schematic diagram explaining the structure of the leak detection apparatus which concerns on 2nd Example. FIG. 5 is a diagram for explaining an example of a method for detecting a moving position in a pipeline of a moving body;

A leak detection method according to the present invention will be described below. A leak detection method according to the present invention is for detecting the presence or absence of a leak in a pipeline through which a liquid flows, and the position of the leak if it occurs.

A leak detection method according to the present invention will be described with reference to FIG. In the present invention, as will be described later, when the liquid is circulating, the sound transmitted through the liquid is collected and recorded at two points separated from each other, and the leak detection device A detects the movement position in the pipeline. is moved along substantially the center of the pipeline B. Therefore, the moving body 1 does not come into contact with the bottom surface of the pipeline B, and it is possible to eliminate the noise generated in such a case. In addition, since the moving body 1 moves along substantially the center of the pipe line B, it is possible to directly collect the sound generated from the pipe wall due to the leakage at two points through the liquid.

Here, the approximate center of the pipeline B means that the center Ba of the pipeline B does not need to be strictly matched, and the range of displacement from the center Ba is not limited numerically. In other words, it means a range in which the moving body 1 does not come into contact with the bottom surface or the side surface of the pipeline B, and the sound caused by the leakage does not interfere.

Then, after the moving body 1 moves through the target section in the pipeline, the sound data of the two sounds collected and stored are compared with the moving position of the moving body 1 in the pipeline B. , it is possible to detect the presence or absence of leakage in the pipeline B and, if it is, the location of the leakage.

That is, the sound transmitted through the liquid to the moving body moving in the pipeline includes the leak sound generated when the liquid leaks from the pipeline, the rubbing sound generated when the liquid comes into contact with the pipe wall, and the The sound generated when passing through the water control valve, the sound generated when air accumulated inside leaks from the air valve, and the rubbing sound generated when a moving object moves through the pipe. , contact noise generated when a moving body comes into contact with the pipe wall, and sound outside the pipe that is transmitted to the pipe through the soil and then through the liquid.

The various sounds described above are collected and stored. Then, it is possible to analyze the stored sound data, extract the sound data of the water leakage sound, and process the sound data other than the water leakage sound as noise.

In this embodiment, the pipeline B indicates a pipeline for water supply, and is constructed by arranging a plurality of cast iron pipes 20 in series and connecting them via packing (not shown) using bolts and nuts. ing. However, the leakage detection method according to the present invention is not only applicable to water supply pipes, but also to pipes through which liquids under pressure flow, such as industrial water pipes and agricultural water pipes. It is of course possible to apply it to pipelines.

Further, it is assumed that the pipeline B has a leak portion 25 including a crack.

In the pipe line B as described above, a valve plug portion C having a valve 18 such as a valve for releasing air mixed in the pipe line B, a valve for closing the pipe line B, or a fire hydrant is provided at appropriate intervals. Therefore, when detecting a leak in the pipeline B, it is common to use this valve plug portion C for work, and the upstream side of a preset section in the pipeline B where leakage is to be detected is detected. The moving body 1 is inserted from the valve plug portion C on the downstream side, and the moving body 1 is discharged from the valve plug portion C on the downstream side.

Therefore, the distance between the valve plug portion C on the upstream side and the valve plug portion C on the downstream side is the length of the pipeline B for which leakage should be detected. However, the distance between the valve plug portion C into which the moving body 1 is inserted and the valve plug portion C into which the moving body 1 is ejected is not limited, and can range from several hundred meters to several kilometers.

Here, the tendency of the sound generated inside the pipeline B will be described with reference to the line 29 shown in the figure. In the portion of the pipeline B where no water leaks, only the sound generated when the clean water flows through the pipeline B is generated. This sound is the rubbing sound of the clean water flowing through the cast iron pipe 20 and the rubbing sound of the moving body 1 of the clean water, and the volume of the sound is substantially constant.

In addition, the leakage part 25 generates a unique sound that is emitted when tap water is jetted from the cast iron pipe 20 to the ground. This sound is maximized at the leaking portion 25 and becomes smaller as the distance from the leaking portion 25 increases. Therefore, the sound becomes a relatively sharp triangle, and the height and size of the tail of the triangle are proportional to the amount of leakage.

As described above, the level of sound data collected and recorded by the sound collecting member (simply referred to as "sound level" hereinafter) is substantially constant at a portion where the volume of sound is substantially constant. However, when the sound generated in the leakage portion 25 interferes with the inner wall of the cast iron pipe 20, the sound collected by the sound collecting member includes interference sound, and the sound data does not form a sharp triangle as shown by the line 29. There are many.

A procedure for detecting leakage in the conduit B having the leakage portion 25 as described above will be described.

First, the two valve plug portions C provided in the pipeline B are selected, and the moving body 1 constituting the leak detection device A is connected to the valve plug portion C installed on the upstream side, and the moving body 1 is connected to the pipeline. An insertion member 21 to be inserted into the pipe B is prepared, and a collection member 22 for collecting the moving body 1 moving in the pipeline B is prepared in the valve plug portion C on the downstream side.

Next, after gripping the moving body 1 at the distal end portion of the insertion device 21, the insertion device 21 is inserted into the pipeline B through the valve plug portion C on the upstream side of the pipeline B. As shown in FIG. In this state, the moving body 1 starts collecting sound and recording sound based on the elapsed time, and further starts detecting the movement position. In addition, when the collection member 22 is inserted into the valve plug portion C on the downstream side and the net-like collection portion provided at the tip reaches the inside of the pipeline B, there is no water leakage from the valve plug portion C. keep it This completes the preparation for detecting leakage in the pipeline B between the valve plug portion C on the most upstream side and the valve plug portion C on the most downstream side.

Next, when the insertion member 21 is operated to release the grip of the moving body 1, the moving body 1 becomes free in the pipeline B, receives the velocity energy of the clean water flowing through the pipeline B, and It moves downstream along the approximate center of B. In the process in which the moving body 1 moves substantially along the center of the pipeline B, the sound of clean water flowing through the pipeline B is collected and recorded as sound data, and the movement position is detected and stored. .

When the moving body 1 is collected by the collecting member 22 arranged in the valve plug portion C on the most downstream side, the collecting member 22 is pulled up. At this time, it is preferable to maintain the state in which the moving body 1 is collected by the collecting member 22, artificially cause water leakage at the valve plug portion C, and record the generated sound.

The sound level recorded by this artificial water leakage has a magnitude corresponding to the amount of water leakage, and the shape of the sound level line is a triangle with a sharp projection. Then, by setting the artificially leaked flow rate to about three types, small, medium, and large, and recording the sound generated at each leak, we can obtain three different types of sound data corresponding to each leak amount. It is possible to record different level lines.

Next, a procedure for comparing the sound recorded by the leak detection device A configured on the moving body 1 pulled up from the pipeline B and the movement position will be described with reference to FIG. 3 . FIG. 3 shows the results of an experiment in which a mobile body 1 having a leak detection device A according to a first embodiment, which will be described later, is inserted into a pipe line B to detect water leakage.

The first sound collecting microphone 11a that constitutes the leakage detection device A is arranged on the upstream end side in the movement direction of the moving body 1, and has directivity toward the upstream side. The second sound collecting microphone 10a is arranged on the downstream end side of the moving body 1 and has directivity toward the downstream side. In particular, the distance between the two sound collecting microphones 10a and 11a is set to 150 mm. Then, the leakage detection device A was inserted into the pipeline B having a diameter of 250 mm and a water leakage portion 25 was formed in advance, and the sound was collected and recorded by flowing down at a speed of about 370 mm per second.

The moving body 1 is received downstream of the pipeline B, and as shown in the figure, the two recorded sound data are compared with the position of the moving body 1 with reference to the time axis common to both. , the sound level line is made to correspond to the extension direction of the pipeline B (the position of the moving body 1). As a result, the sound level line 30 by the microphone (second sound collecting microphone 10a) having directivity toward the downstream side shown in FIG. 3(a) and the directivity toward the upstream side shown in FIG. A sound level line 31 was obtained by the microphone (the first sound collecting microphone 11a) . Then, the presence of portions 30a and 31a having flat tops on the sound level lines 30 and 31 was confirmed. The time interval delta t between both portions 30a and 31a corresponds to the flowing speed of the moving body 1 and the interval between the two sound collecting microphones 10a and 11a.

As a result of the above experiment, it was confirmed that the existence and position of water leakage can be detected by inserting the water leakage detection device A into the pipeline B and collecting and recording the sound.

Therefore, by receiving the moving body 1 flowing down the pipeline B and matching the two recorded sound data with the position of the moving body 1 with reference to the common time axis, the extension of the pipeline B It is possible to correspond the sound level lines 30, 31 to the direction (position of the moving body 1). By associating the sound level lines 30 and 31 with the extending direction of the pipe line B and examining the sound level changing portions in the sound level lines 30 and 31, the state of the changing portions can be determined. can be inferred.

In particular, it is presumed that the top portions 30a and 31a of the sound level lines 30 and 31 are clearly abnormal, and that there is a leakage portion 25 in the pipeline B corresponding to between the portions 30a and 31a. It is possible to Furthermore, by comparing the shape of the sound level line corresponding to each flow rate when artificially leaking at the valve plug portion C on the most downstream side with the shapes of the portions 30a and 31a, the leakage portion It is possible to estimate the amount of leakage at 25.

Next, the configuration of the leak detection device according to the present invention will be described. In the present invention, the moving body 1 that constitutes the leak detection device A moves substantially along the center of the pipeline B together with the liquid flowing through the pipeline B. As shown in FIG. The configuration of the moving body 1 that moves along the approximate center of the pipeline B is not particularly limited. However, it is preferable to set the specific gravity of the moving body 1 to an appropriate value with respect to the specific gravity of the liquid.

For example, by setting the specific gravity of the moving body 1 to be substantially the same as the specific gravity of the liquid, it is possible to move the moving body 1 along substantially the center of the pipeline B. In this case, it is preferable that the liquid flowing through the conduit B maintains a laminar flow state. Further, by setting the specific gravity of the moving body 1 to be slightly smaller than the specific gravity of the liquid and attaching a specific gravity adjusting member to the outer periphery, it is possible to move the moving body 1 substantially along the center of the pipe line B.

The shape of the moving body 1 is not particularly limited, and is preferably a cylindrical body having a length capable of accommodating each member to be arranged therein, or a cylindrical body having a substantially circular cross section. In the case of such a cylindrical body, the front and rear ends are preferably spherical. In addition, although the dimensions are not limited, it is necessary to have an outer diameter sufficiently smaller than the inner diameter of the target pipeline B, and it is necessary to have a dimension that allows it to easily pass through the valve plug portion C. is. Since the pipe forming the valve plug portion C normally has a diameter of 75 mm, the outer diameter of the moving body 1 is preferably about 50 mm to 70 mm. Also, although the length corresponds to the structure of the member to be accommodated, it is preferably about 100 mm to about 200 mm.

In particular, in order to stabilize the attitude of the moving body 1 when it moves inside the pipeline B, it is preferable to dispose the members housed therein so that the weight is concentrated on the lower part. By arranging in this way, it is possible to reduce the rolling that may occur during movement.

Further, when the moving body 1 moves along the bent portion of the pipeline B in the horizontal direction, a force acts to rotate the moving body 1 in the horizontal direction. In order to resist this force, it is preferable to configure the moving body 1 so that the weight can be distributed to both front and rear ends. By configuring in this way, it becomes easier to suppress yawing.

Therefore, it is preferable that the movable body 1 is a cylindrical body having an appropriate length, and is configured so that the weight acts on the front and rear ends and the bottom.

When the moving body 1 moves inside the pipeline B, there is a possibility that the bent portion formed in the pipeline B may come into contact with the pipe wall. For this reason, it is preferable that a cushion material is arranged on the outer peripheral surface of the moving body 1 . The cushioning material has a function of absorbing shocks to the equipment accommodated inside the moving body 1, and the material is not limited as long as it can exhibit such a function.

That is, the cushioning material may be any material that is softer than the material constituting the main body of the moving body 1, and rubber-based or urethane-based materials can be used. may be about 1 mm to 3 mm. Also, the arrangement of the cushion material on the outer peripheral surface of the moving body 1 is not limited, and it may be integrated by a method such as adhesion or coating.

A leak detection device A according to the present invention is inserted into a conduit B through which liquid flows, moves along substantially the center of the conduit B, and detects sound transmitted through the liquid when the liquid is circulated. are simultaneously collected by the first sound collecting member and the second sound collecting member, and the collected sounds are respectively recorded as sound data in the first recording member and the second recording member, and in the pipeline B It is configured to be detectable by a position detection member that detects the movement position of the body.

In particular, a reference clock is arranged in the leak detection device A, and devices including two recording members for recording sound data and a position detection member for detecting the movement position are controlled based on the clock signal generated from the reference clock. be done. That is, the two recording members record sound data at the same timing, and the position detection member is configured to detect the movement position of the moving body.

The two sound-collecting members simultaneously collect the sound generated when the pressure fluid flows through the pipeline in which leakage is to be detected and transmitted through the liquid, and can exhibit this function. Anything can be used. The distance between the two sound collecting members is not particularly limited, and it is preferable to set the distance appropriately according to the dimensions of the moving body 1 . For example, it is preferable that the distance between the two sound collecting members is in the range of about 75 mm to about 150 mm.

A small microphone is preferably used as the sound collecting member as described above. Whether the sound data of the sound collected and stored by the sound collecting member is analog information or digital information is not limited, and any information may be used.

If there is a possibility that the sound generated at the leaking portion may interfere with the pipe wall, it is preferable to employ a sound collecting member having directivity. One of the sound collecting members is arranged so as to exhibit directivity upstream in the moving direction of the moving body, and the other sound collecting member is arranged so as to exhibit directivity downstream in the moving direction of the moving body. Arrangement is particularly preferred.

For example, sound level lines collected by using two omnidirectional sound collecting members are in a state in which two curves having substantially the same shape are shifted. Then, it becomes possible to presume that there is a leak between the displaced apexes.

However, the sound level lines 30 and 31 collected by using two sound collecting members having directivity and arranging one on the upstream side and the other on the downstream side so as to exhibit directivity are shown in FIG. , two curves having substantially the same shape are diametrically overlapped and shifted. Then, it becomes possible to presume that the leak portion 25 exists between the top portions 30a and 31a.

Sounds collected by the two sound collecting members are respectively recorded as sound data on two recording members. The recording member in the present invention may be any member having a function of recording the collected sound, and it is possible to selectively use a recorder, a memory element, or the like according to the type of information.

The position detection member is for detecting the position of the water leakage detection device in the pipeline for which leakage should be detected. Any material that can exhibit such a function can be used. A combination of a gyro sensor and an acceleration sensor can be used as the position detection member.

When a gyro and an acceleration sensor are used as the position detection member, the movement position from the time when the moving body constituting the leak detection device is inserted into the pipeline to detect the leak is calculated by the gyro and the acceleration sensor. It is stored independently or in a storage means mounted on a moving object. In this way, communication with the outside is not required for the purpose of detecting the position of the moving body, and the extension distance of the pipeline for leak detection depends on the capacity of the power supply accommodated in the moving body and the collected sound. It is set according to conditions such as the recording capacity of the recording member for recording.

As described above, it is preferable to store the signals generated from the gyro and acceleration sensors in the storage means mounted on the mobile object, but the present invention is not limited to this configuration, and may be configured to communicate wirelessly with the outside. good. In this case, it is possible to immediately check the moving position of the moving body by installing a receiving device, a storage device, and an arithmetic device on the ground. Furthermore, by configuring the recording member so as to be able to communicate with the outside, it becomes possible to match the moving position of the moving body with the sound data.

In addition, a transmitting member for transmitting a pulse signal corresponding to a reference clock is mounted on the moving body, and the pulse signal transmitted from the transmitting member is received outside the pipeline in synchronization with the reference clock of the transmitting member. It is also possible to configure the position detection member by arranging members.

The position detection member configured as described above can detect the position of the moving body in the pipeline by the time difference between the pulse signal transmitted from the transmission member and the reception member. In this case, one or two receiving members may be provided along the pipeline to be detected.

Next, the configuration of the leak detection device A according to the first embodiment will be described with reference to FIG. In the present embodiment and a second embodiment described later, the position detection member for detecting the movement position of the moving body in the pipeline is constructed using a gyro and an acceleration sensor.

The leak detection device A shown in the figure is configured for the purpose of detecting a leak in the pipeline B for water supply shown in FIG. It is constructed so as to be able to receive the speed energy of the circulating tap water and move.

When water such as tap water, industrial water, agricultural water, etc. flows through a pipeline whose leakage should be detected, the propagation of sound is affected by the water temperature. For this reason, the leakage detection device is preferably configured to measure and record water temperature in addition to recording sound and detecting position.

The leakage detection device A according to this embodiment has a water temperature measuring member (not shown) configured to measure the water temperature and store the measured water temperature.

The leak detection device A is made of metal such as aluminum or plastic, and has a moving body 1 comprising a main body 1a having a cylindrical smooth outer peripheral surface and a cap 1b having a hemispherical smooth outer peripheral surface. there is When the cap 1b is attached to the main body 1a via a packing (not shown), an accommodation space 1c is formed therein for accommodating devices necessary for detecting leaks in the pipeline. Accordingly, the accommodation space 1c for the moving body 1 is configured as a closed space.

In the housing space 1c formed in the moving body 1, a sound collecting microphone 11a serving as a first sound collecting member constituting the leakage detection device A, and a first sound collecting microphone 11a for recording sound collected by the first sound collecting microphone 11a . A recorder 11b, a sound collecting microphone 10a as a second sound collecting member, a second recorder 10b for recording sound collected by the second sound collecting microphone 10a , a gyro 12a constituting the position detection member 12, and Acceleration sensor 12b, sound collecting microphone 10 having a clock function and controlling operation of recorder 11, position detection member 12, control unit 13, power source 14, and the like are provided.

The first sound collecting microphone 11a is arranged on the upstream side in the moving direction of the moving body 1, and has directivity toward the upstream side. The second sound collecting microphone 10a is arranged on the downstream end side of the moving body 1 and has directivity toward the downstream side.

A moving body 1 that accommodates devices such as two sound collecting microphones 10a and 11a, two recorders 10b and 11b, a gyro 12a, an acceleration sensor 12b, a control unit 13, a power supply 14, and a water temperature measuring member in an accommodation space 1c. is set to have a specific gravity substantially equal to that of the liquid. Therefore, by inserting the moving body 1 into the pipeline B, it is possible to move downstream together with the liquid flowing through the pipeline B.

In this embodiment, the liquid flowing through the conduit B maintains a laminar flow state.

When the moving body 1 is inserted into the pipeline B through which the liquid flows in a laminar flow state, the moving body 1 moves along substantially the center (Ba) of the pipeline B with the liquid flowing in a laminar flow state. do. In the process of moving the moving body 1 along substantially the center of the pipeline B, the sound generated from the liquid is simultaneously collected and recorded at two locations, and the movement position in the pipeline B is detected. , the presence or absence of leakage, and the location of leakage.

For example, as shown in FIG. 4, when the moving body 1 is at a position eccentric from the center Ba of the pipe line B, a laminar flow with a large flow velocity V on the center side of the outer peripheral surface of the moving body 1 is generated on the side of the center Ba. The flowing liquid comes into contact, and the liquid flowing at a small flow velocity v comes into contact with the tube wall side. Therefore, due to the difference in flow velocity (Vv) in contact with the moving body 1, a force acts on the moving body 1 in the direction of the liquid flowing at a high flow velocity V, and the moving body 1 moves in the direction of the pipeline B in response to this acting force. Displace to the center and stabilize.

The moving body 1 constructed as described above is inserted into the pipeline B from the valve plug portion C installed on the upstream side according to the leak detection method described above, and is moved together with the flowing liquid. In this movement process, sound collection is started at two locations based on the elapsed time, recording of each sound is started, and detection of the movement position is started. Then, when the moving body 1 reaches the valve plug portion C on the downstream side, it is collected by the collection member 22 and separated from the pipeline B.

After that, by comparing the two sounds recorded by the moving body 1 and the movement position, the sound level lines 30 and 31 in the extension direction of the pipeline B are made to correspond, and the leakage part 25 in the pipeline B is determined. Presence, it is possible to infer the amount of leakage at the leakage portion 25 .

For example, when the flow velocity of the liquid in the pipeline B decreases, there is a possibility that the moving body 1 approaches the wall surface of the pipeline B and comes into contact with it. In order to avoid such contact, it is preferable to arrange a plurality of contact members made of linear or plate-shaped spring material formed in a gentle curve along the outer peripheral surface of the moving body 1 along the longitudinal direction. preferable. By configuring in this way, the moving body 1 does not come into contact with the wall surface of the pipeline B. Further, even if the contact member contacts the wall surface and generates sound, since it is composed of a curved spring material, a large impact sound is generated and the moving body 1 is not flipped by the reaction force. Nor.

Next, the configuration of the moving body 2 that constitutes the leakage detection device A according to the second embodiment will be described with reference to FIG. In the figure, the part indicated by the two-dot chain line assumes a state in which the moving body 2 is inserted into the pipeline B. As shown in FIG. In this embodiment, the same parts and parts having the same functions as those in the previous embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

A leakage detection device A according to this embodiment has a moving body 2 comprising a cylindrical main body 2a and a hemispherical cap 2b. Inside the movable body 2, a sealed accommodation space 2c is formed. In the accommodation space 2c, two sound collecting microphones 10a and 11a, two recorders 10b and 11b, a gyro 12a and an acceleration sensor 12b constituting the position detection member 12, a control unit 13, a power supply 14, a water temperature measurement member, etc. is provided.

The moving body 2 constituting the leak detection device A configured as described above has a specific gravity set slightly smaller than the specific gravity of the liquid flowing through the pipeline B. As shown in FIG. Therefore, when the moving body 2 is inserted into the pipeline B, the moving body 2 floats. For this reason, a specific gravity adjusting member 3 is provided to prevent the moving body 2 from floating and position it substantially at the center of the pipeline B. As shown in FIG.

That is, a mounting portion 2d is formed on the outer peripheral surface of the main body 2a of the moving body 2, and the specific gravity adjusting member 3 is mounted on the mounting portion 2d. The specific gravity adjusting member 3 is made of a flexible member such as a string-like member or a chain, and one end 3a is attached to the mounting portion 2d, and the other end 3b is attached to the bottom surface of the target pipeline B. It is configured to be dragged by Therefore, the length of the specific gravity adjusting member 3 is set to be substantially equal to or longer than the radius of the target pipeline B.

A flange 2e is formed on the outer peripheral surface of the main body 2a of the moving body 2 for receiving the energy of the flowing liquid. Although the number of flanges 2e is not limited, four flanges 2e are formed in this embodiment.

When the moving body 2 constituting the leak detection device A constructed as described above is inserted into the conduit B, the moving body 2 maintains a posture with the specific gravity adjusting member 3 facing downward. Furthermore, the end 3b side of the specific gravity adjusting member 3 contacts the bottom surface of the conduit B and drags it.

In this embodiment, the specific gravity of the moving body 2 constituting the leak detection device A is set to 0.8 to 0.9 times the specific gravity of the liquid. When the moving body 2 is inserted into the pipeline B, a buoyant force corresponding to the unit volume weight density of the liquid and the volume of the moving body 2 acts on the moving body 2 . For this reason, assuming the moving speed of the circulating liquid in advance, when the moving body 2 moves along substantially the center of the conduit B together with the liquid, the end portion 3b of the specific gravity adjusting member 3 is in contact with the bottom surface. Assuming an angle (approximately 45 degrees) of the specific gravity adjusting member 3 , the material is set so that the underwater weight of the specific gravity adjusting member 3 corresponding to the length of this 45 degrees is equal to the buoyant force acting on the moving body 2 . . The length of contact between the end 3b of the specific gravity adjusting member 3 and the bottom surface of the conduit B is about 1/4 to 1/3 of the 45-degree length of the specific gravity adjusting member 3. is preferred.

By setting the specific gravity adjusting member 3 as described above, when the moving body 2 is inserted into the pipeline B, the moving body 2 moves along substantially the center of the pipeline B, and the specific gravity adjusting member provided on the lower side moves. 3 is dragged by bringing the end 3b side into contact with the bottom surface, and the portion in the liquid is inclined at about 45 degrees.

The moving body 2 constituting the leak detection device A configured as described above has its specific gravity adjusted by the specific gravity adjusting member 3, and the end 3b of the specific gravity adjusting member 3 is in contact with the bottom surface of the pipe line B. As shown in FIG. Therefore, regardless of whether the liquid flowing through the pipeline B is in a laminar flow state or a turbulent flow state, the liquid can move substantially along the center of the pipeline B.

Then, as in the first embodiment described above, in the process of moving along the approximate center of the pipeline B, the presence of the leaking portion 25 in the pipeline B and the amount of leakage at the leaking portion 25 are estimated. It is possible to

Next, another example of detecting the moving position of the moving body 1 in the pipeline B constituting the leakage detection device A will be described with reference to FIG.

In this example, a moving body 1 or 2 (hereinafter referred to as "moving body 1") moving in pipeline B transmits a pulse signal, the pulse signal is received outside pipeline B, and the moving body The amount of movement is measured by detecting the time difference between the pulse signals emitted in the process of moving in one pipeline. For this reason, a transmitting member (not shown) for transmitting a pulse signal is mounted on the moving body 1, and a receiving member for receiving the pulse signal constituting a position detecting member is mounted on the outside of the conduit B. A receiving device 19 having a is arranged.

That is, the moving body 1 is equipped with a control section (13) having a clock function, and pulses of sound waves, ultrasonic waves, radio waves, or the like are transmitted at regular time intervals corresponding to the reference clock of this control section. A transmitter is mounted. The receiving device 19 also includes a receiving member for receiving the pulse signal transmitted from the moving body 1, a clock function synchronized with the control section mounted on the moving body 1, and a recording function for recording the pulse signal received by the receiving member. The control unit is arranged. The position detection member (12) is configured by including these transmitting member and receiving member.

The transmitting member and the receiving member are driven synchronously (corresponding to a reference clock), the pulse signal transmitted from the transmitting member is received by the receiving member, the time difference between the received pulse signals is measured, and at the same time the water temperature to measure By correcting the measured time difference data with the propagation speed corresponding to the water temperature of the liquid, it is possible to measure the amount of movement of the moving body 1 . By integrating the measured amount of movement, it is possible to detect the movement position of the moving body 1 in the pipeline B. FIG.

The receiving device 19 is arranged in the valve plug portion C arranged in the pipeline B outside the pipeline B. As shown in FIG. The number of receiving devices 19 arranged in the pipeline B is not particularly limited, but it is preferable to install them at both ends of the pipeline B for which leak detection is to be performed. It is preferable to appropriately set the number of arrangement according to the situation.

Each valve plug portion C is provided with a valve 18 having a function of removing air mixed in the pipe line B and a function of preventing leakage of liquid. It is configured to be able to release the air. A small microphone 19a is provided inside the cover of the valve 18 of the selected valve plug portion C, and the small microphone 19a and the receiving device 19 are connected by a communication line 19b.

Therefore, by opening the valve 18 of the valve plug portion C in which the receiving device 19 is arranged to discharge the accumulated air and fill it with a liquid having pressure, the pulse transmitted from the transmitting member mounted on the moving body 1 is The signal can be picked up by a small microphone 19a. Also, by transmitting the collected sound to the receiving device 19 via the communication line 19b, it is possible to record it in the control unit.

Therefore, a pulse signal is transmitted from the moving body 1 moving in the pipe line B, this pulse signal is received by the receiving device 19, and the time difference between the pulse signals transmitted while the moving body 1 moves in the pipe line is detected. By doing so, it is possible to detect the movement position.

The leakage detection device and leakage detection method of the present invention can be applied to water pipelines and oil pipelines as long as they are pipelines through which a liquid having pressure flows.

A leakage detection device B pipe line C valve plug portion 1, 2 moving body 1a, 2a main body 1b, 2b cap 1c, 2c accommodation space 2d mounting portion 2e flange 3 specific gravity adjusting member 3a, 3b end portion 10a, 11a sound collecting microphone 10b , 11b recorder 12 position detection member 12a gyro 12b acceleration sensor 13 control unit 14 power supply 18 valve 19 receiver 19a small microphone 19b communication line 20 cast iron pipe 21 insertion member 22 collection member 25 leakage part 29 wire 30, 31 sound level wire 30a, 31a top

Claims (6)

A leak detection method for detecting a leak in a pipeline through which a liquid with pressure flows, comprising:
A first sound collecting member arranged upstream in the moving direction and directed toward the upstream side when the liquid having pressure flows through; A moving body configured to collect and record the sound transmitted through the liquid by the second sound collecting member and to detect the movement position in the pipeline is circulated in the pipeline. Two sound data of the sound transmitted through the liquid which is moved along with the liquid along the approximate center of the pipeline and recorded during the moving process of the moving body, and the detected movement of the moving body in the pipeline A leak detection method, characterized by detecting the location of a leak in a pipeline according to the location and the location of the leak. A leakage detection device for detecting leakage in a pipeline through which a liquid with pressure flows,
An outer diameter is smaller than the inner diameter of the pipe, and it is arranged inside the pipe on the upstream side in the moving direction to collect sound transmitted through the liquid when the liquid flows through the pipe. a first sound collecting member having a directivity toward and a first recording member for recording the sound collected by the first sound collecting member; a second sound collecting member arranged to collect sound transmitted through the liquid when the liquid circulates in the pipeline and having directivity toward the downstream side in the moving direction; and the second sound collecting member Having a moving body in which a second recording member for recording collected sound and a position detection member for detecting a movement position in the pipeline are arranged and which moves together with the liquid inside the pipeline. A leakage detection device characterized by: 3. The leakage detection device according to claim 2, wherein the liquid having the pressure flows through the pipeline while maintaining a laminar flow state. 4. A leakage detection device according to claim 2, wherein said moving body is formed as a cylindrical body. 5. The member for detecting the position of movement of the moving body in the pipeline comprises a gyro and an acceleration sensor mounted on the moving body. A leak detection device as described above. A member for detecting the movement position in the pipeline of the moving body is mounted on the moving body and transmits a pulse signal corresponding to a reference clock, and a pipeline to detect leakage. a pulse signal transmitted from the transmitting member moving inside the pipeline to be detected; is received by the receiving member, and the moving position of the moving body in the pipeline can be detected from the time difference between when the pulse signal transmitted from the transmitting member is received by the receiving member. A leakage detection device according to any one of claims 2 to 4.

Images