JP4685487B2 - Sonic piping survey system and piping survey method using the same - Google Patents

Description

  The present invention relates to a sonic piping survey system and a piping survey method using the same, and in particular, a sonic piping survey system for investigating a pipeline state by measuring a reflected wave of a sound wave incident on a pipeline and processing the signal. And a pipe survey method using the same.

  In general, a large number of pipes for accommodating power cables and various communication cables, including pipes for gas and water and sewage, are buried or laid underground, on the ground, or inside buildings. These pipes tend to gradually deteriorate over time due to physical and chemical influences. Therefore, the internal state of these pipes is checked by periodic inspection or inspection as needed, and appropriate repairs are performed as needed. In addition, in order to confirm whether the piping is laid as designed, the internal state is also investigated. The sonic type pipe survey system for investigating the internal state of such a pipeline is being studied.

  As a conventional sonic piping survey system, there is one disclosed in Japanese Patent Laid-Open No. 11-125623 (Patent Document 1). The sound wave type pipe survey system disclosed in Patent Document 1 includes a speaker (sound generation unit) and a microphone (sensor unit), and includes an assembly attached to a pipe end of a pipe structure (pipe). The speaker is a means for transmitting an acoustic signal (sound wave signal) from the pipe end to the inside of the piping structure, and the microphone is a means for receiving a reflected wave from the inside of the piping structure. A signal generation circuit and an amplifier are provided as a circuit for transmitting a sinusoidal acoustic signal to the inside of the piping structure using a speaker. The acoustic signal transmitted to the inside of the piping structure by the speaker is reflected by various acoustic discontinuities generated in the piping structure, for example, joints. The microphone receives such a reflected wave and supplies it to the arithmetic unit. The calculation unit detects the frequency characteristic of the acoustic signal reflectivity, and compares this with the frequency characteristic measured in advance for each type of joint, thereby determining the type of each joint.

JP-A-11-125623

  In the sonic piping survey system of Patent Document 1, consideration is given to discriminating the type of each joint, but consideration for multiple reflected waves is not disclosed.

  When investigating the inside of a pipe line using sound waves, multiple reflections occur in the sound waves incident from the sound generation unit, and when this multiple reflection wave signal is observed, the signal is sent from the reflection source in the pipe line. There is a risk of misjudging that it is. Multiple reflections occur mainly between the branch part or terminal part located in the pipe and the sensor part of the reflected sound wave, and are not related to the reflected signal from the normal installation position such as the branch part located in the pipe. Therefore, there is a risk of erroneous determination that there is a member serving as a reflection source in the pipe line even though it does not exist in the pipe line.

  An object of the present invention is to provide a sound wave type pipe survey system capable of accurately discriminating between an actual reflected wave signal and a multiple reflected wave signal, and a pipe survey method using the same.

In order to achieve the above-mentioned object, the sound wave type pipe survey system according to the first aspect of the present invention includes a sound generation unit that inputs a sound wave signal that is a periodic signal into a pipe line of a pipe to be investigated, and an incident sound wave signal. Attached to the end of the pipe with the sensor unit for measuring the reflected wave signal, the signal processing unit for processing the reflected wave signal obtained by the sensor unit, and the sound generation unit and the sensor unit attached thereto. and a conduit length varying mechanism for changing the metering duct length Te, the conduit length variable mechanism includes a fixed portion attached to the end of the pipe, while wearing the sound generator and the sensor unit A movable part that is movably attached to the fixed part and changes the length of the measurement pipeline , and the signal processing unit moves the movable part to input the sound wave signal by the sounding part at a plurality of positions. Each obtained by measuring with the sensor unit The start position of the reflected wave signal is corrected by the movement amount of the movable portion with matching the reference position, by adding the respective reflected wave signal after correction, multiple reflection occurring between the reflection point and the sound generator multiple reflection wave identification for performing the processing to differ from the waveform of the reflected wave signal from the reflection point of the waveform of the multiplexed reflected wave signal with enlarging the size difference between the reflected wave signal from the wave signal and the reflection point It is in the structure provided with the means.
A more preferable specific configuration example in the first aspect of the present invention is as follows.
(1) The sound wave signal is a sine wave signal of one cycle, and the delay time of the start position of the reflected wave signal from the reflection point due to the movement of the movable part is shorter than the time of the sine wave signal of one cycle of the sound wave signal. The waveform of the added multiple reflected wave signal is different from that of a sine wave.

In order to achieve the above-described object, the sound wave type pipe survey system according to the second aspect of the present invention includes a sound generation unit that inputs a sound wave signal into a pipe line of a pipe to be investigated, and a reflected wave signal of the incident sound wave signal. A sensor section for measurement, a signal processing section for processing a reflected wave signal obtained by the sensor section, a measurement pipe length attached to an end of the pipe with the sound generation section and the sensor section mounted A variable pipe length mechanism, and the variable pipe length mechanism includes a fixed portion attached to an end portion of the pipe, and a movable portion movably attached to the fixed portion. And the movable portion is movably installed on the fixed portion, and the signal processing unit moves the movable portion to move to a plurality of positions. The sound wave signal is incident by the sound generation unit and the sensor unit Each reflected wave signal obtained by performing the measurement is corrected by the amount of movement of the movable part to match the reference position and added, and multiple reflected wave signals generated between the sounding part and the reflection point And multiple reflected wave identification means for performing processing for enlarging the difference in magnitude from the reflected wave signal from the reflection point.
A more preferable specific configuration example in the second aspect of the present invention is as follows.
(1) pre-Symbol fixing part is provided with a fixed tube-shaped member disposed on an end portion outside of the pipe, the movable portion is slidably disposed engages axially on the outside of the fixed tubular member Provided with a movable cylindrical member.
( 2 ) In addition to the above ( 1 ), a step closing member is provided that covers the stepped portion formed by the sliding portion of the movable cylindrical member having an inner diameter larger than the inner diameter of the pipe projecting from the opening end of the pipe over the movable range. Was it.
( 3 ) In addition to the above ( 2 ), the step closing member is formed of a thin cylindrical member extending from the movable cylindrical member to the inner surface of the end portion of the pipe.

According to the third aspect of the present invention for achieving the above object, the pipe survey method using the sonic pipe survey system is a sound generation method in which a sound wave signal that is a periodic signal is incident on a pipe line of a pipe to be surveyed. A sensor unit for measuring the reflected wave signal of the incident sound wave signal, a signal processing unit for processing the reflected wave signal obtained by the sensor unit, a fixing unit attached to an end of the pipe, and the sound generation And a movable part that is movably attached to the fixed part in a state in which the sensor part and the sensor part are mounted and that changes the measurement pipe length, and a variable pipe length mechanism that changes the measurement pipe length. In the pipe survey method using the acoustic wave pipe survey system, the sound generation part and the sensor part are arranged at a reference position, and a sound wave signal is incident on the pipe line of the pipe and a reflected wave signal is measured, and the movable part is measured. at a plurality of positions by moving the parts Serial sound unit performs the measurement of the reflected wave signal by the incident and the sensor portion of the sound signal by, causing the start position before Symbol meter measuring and the reflected wave signals match the reference position is corrected by the movement amount of the movable portion together, and it adds the reflected wave signal after correction, the multi-reflected wave causes a larger difference between the reflected wave signals from the multiple reflection wave signal and reflection points occurring between the reflection point and the sound generator The signal processing unit performs processing for making the signal waveform different from the waveform of the reflected wave signal from the reflection point .

A more preferable specific configuration example in the third aspect of the present invention is as follows.
(1) The sound wave signal is a one-cycle sine wave signal, the delay time of the start position of the multiple reflected wave signal due to the movement of the movable part is shorter than the time of the one-cycle sine wave signal of the sound wave signal, Make the waveform of the added multiple reflected wave signal different from the sine wave .

  According to the sound wave type pipe survey system and the pipe survey method using the same according to the present invention, an actual reflected wave signal and a multiple reflected wave signal can be accurately identified.

  Hereinafter, a sonic pipe survey system and a pipe survey method using the same according to an embodiment of the present invention will be described with reference to the drawings.

  First, the overall configuration of the sonic piping survey system of this embodiment will be described with reference to FIG. FIG. 1 is a block diagram of a sonic piping survey system according to an embodiment of the present invention.

  The sound wave type pipe survey system 10 is attached to the sound generation part 2 that makes a sound wave incident on the pipe line of the pipe 1 to be investigated, the sensor part 3 that measures the reflected wave of the incident sound wave, and the end part of the pipe 1. A variable pipe length mechanism 4 for changing the measurement pipe length, a signal generator 5 for generating a signal to be sent to the sound generation section 2, a signal processing section 6 for processing a reflected wave signal obtained by the sensor section 3, A waveform display unit 7 that displays a waveform processed by the signal processing unit 6 is configured as a main component.

  The pipe 1 to be investigated is a gas pipe or a water pipe made of a steel pipe or the like. In the illustrated example, the pipe 1 has a branch part 1a in the middle of the pipe path, and one end of the pipe is opened. On the other side, piping continues. In general, the pipe 1 is connected in various ways in a state where a plurality of pipes are combined through various joints, and the inside of the pipe 1 is branched and connected to a branch pipe or connected to an elbow pipe. The sonic pipe survey system 10 of the present embodiment is intended to identify the pipe line state such as the presence or absence of these joint states, branch states, and elbow states by sound waves.

  The sound generating unit 2 is constituted by a speaker or the like, and is attached to one end of the pipe length variable mechanism 4 so as to face the pipe path, and the pipe 1 passes through the pipe path formed inside the pipe length variable mechanism 4. The sound wave is configured to enter the pipe line. Note that the periodic signal generated by the signal generator 5 is amplified by the amplifier 8 and transmitted to the sound generator 2, and the periodic signal is emitted from the sound generator 2 into the piping.

  The sensor unit 3 is composed of a microphone or the like, and is located in the vicinity of the sound generating unit 2 and attached to the variable pipe length mechanism 4. The reflected wave of the incident sound wave is transmitted in the pipe line of the variable pipe length mechanism 4. It is configured to receive. The reflected wave signal received by the sensor unit 3 is amplified by the amplifier 9 and transmitted to the signal processing unit 6.

  The pipe length variable mechanism 4 is airtightly attached to the one-side opening end portion of the pipe 1 with the sound generation part 2 and the sensor part 3 attached when measuring the pipe line. The inside of the variable pipe length mechanism 4 constitutes a pipe line communicating with the pipe line of the pipe 1. The variable pipe length mechanism 4 is removed after the measurement is completed, and the regular pipe 1 is disposed in that portion.

  The signal processing unit 6 processes the reflected wave signal obtained by the sensor unit 3 so that it can be displayed on the waveform display unit 7, and includes multiple reflected wave identification means 61. The multiple reflected wave identifying means 61, which is shown in block form in FIG. 1, is constituted by a part of processing software, and performs a process of reducing the multiple reflected wave signal between the sound generating unit 2 and the reflection point. Is. The multiple reflected wave discriminating means 61 moves the movable part 42 of the pipe length varying mechanism 4 and receives each reflected wave of the sound wave signal by the sounding part 2 and measurement by the sensor part 3 at a plurality of positions. The wave signal is corrected by the amount of movement of the movable unit 42 to match the reference position and added, and the multiple reflected wave signal generated between the sound generating unit 2 and the reflection point and the reflected wave signal from the reflection point A process of enlarging the difference in size is performed. In this embodiment, the reflection point is the branching portion 1a.

  The sonic piping survey system 10 includes a mechanical unit 10A including a sound generation unit 2, a sensor unit 3 and a pipe length variable mechanism 4, a signal generator 5, an amplifier 8, an amplifier 9, a signal processing unit 6, and a waveform display unit 7. The electric unit 10B is unitized, and the units 10A and 10B can be connected by wiring. As a result, even if the pipe 1 is an embedded pipe, the sonic type pipe survey system 10 can be easily installed, and handling such as transportation is also good.

  Next, a specific configuration of the variable pipe length mechanism 4 will be described with reference to FIGS. FIG. 2 is a partial cross-sectional side view of the pipe length variable mechanism 4 attached to the pipe 1 according to the present embodiment, and FIG. 3 is an enlarged view of a main part of FIG. 2 and 3, (a) shows a state in which the conduit length varying mechanism 4 is most contracted, and (b) shows a state in which it is extended the longest.

  The variable pipe length mechanism 4 includes a fixed portion 41 attached to the opening end of the pipe 1 and a movable portion 42 movably attached to the fixed portion 41. The fixed portion 41 includes a fixed cylindrical member 41a disposed on the outer side of the opening end of the pipe 1, and the movable portion 42 is movable so as to be engaged with the outer side of the fixed cylindrical member 41a and slidable in the axial direction. A cylindrical member 42a is provided. Specifically, the fixed portion 41 includes a fixed cylindrical member 41a and a fixed nut 41b, and the movable portion 42 includes a movable cylindrical member 42a, a sound generating portion holding member 42b, and a step closing member 42c.

  The fixed cylindrical member 41a is screwed to the fixed nut portion 41b in an airtight manner through a seal, and the fixed nut portion 41b is attached to the pipe 1 in an airtight manner through the seal. The movable cylindrical member 42a is provided with a sealing material 42d such as an O-ring at a portion that is engaged with the outside of the fixed cylindrical member 41a and slides in the axial direction, thereby airtightness with the fixed cylindrical member 41a. Is given. The sound generating portion holding member 42b is screwed to the end of the movable cylindrical member 42a and is airtightly fixed to the movable cylindrical member 42a. With this configuration, the inside of the pipe length variable mechanism 4 is kept airtight with respect to the pipe 1 and constitutes a part of the pipe line for measurement together with the inside of the pipe 1.

  The sensor unit 3 is attached to the movable cylindrical member 42 a so that a reflected wave signal can be received from the internal piping path of the movable unit 42. Further, the sound generating part 2 is attached to the sound generating part holding member 42b so as to face a pipe line inside the movable part 42, and a sound wave signal can be incident on the pipe line.

The step closing member 42 c has a stepped portion 4 2 e formed by the sliding portion of the movable cylindrical member 42 a having an inner diameter larger than the inner diameter of the pipe 1 protruding from the opening end of the pipe 1. It is a thing to block over. The step closing member 42c is formed of a thin-walled cylindrical member that extends from the movable cylindrical member 42a to the inner surface of the end portion of the pipe 1. Note that the step closing member 42c can be set to such a thickness that multiple reflected wave signals generated by the step portion formed between the pipe 1 and the pipe 1 can be ignored.

  In the case of the illustrated example, the pipe length at the time of measurement is the length from the sound generating unit 2 to the branching unit 1a. The pipe length in the state in which the pipe length variable mechanism 4 is most contracted is the length L shown in FIG. 2A, and the pipe length in the state in which the pipe length variable mechanism 4 is most extended is FIG. 2B. Is the length L + 3ΔL shown in FIG. In addition, the pipe length variable mechanism 4 can set the expansion-contraction to arbitrary positions. Thereby, the number of times of measurement can be easily increased. In addition, it is desirable that the pipe length varying mechanism 4 is provided with a position sensor, and each of the expanded and contracted positions is automatically measured by the position sensor and taken into the signal processing unit 6.

  Next, an operation example of the sonic piping survey system 10 will be described with reference to FIGS. 4 and 5. FIG. 4 is an operation flow diagram of the sonic piping survey system of this embodiment, and FIG. 5 is a waveform diagram corresponding to FIG.

  The case where the investigation is started after the pipe length variable mechanism 4 is attached to the pipe 1 in the most contracted state will be described. First, a 1-cycle sine wave signal, which is a periodic signal, is generated by the signal generator 5 (step S1). This sine wave signal is amplified by the amplifier 8 (step S2), and then enters the pipe 1 from the sound generator 2 as a sound wave signal (step S3).

The reflected wave reflected in the pipe 1 is measured by the sensor unit 3 (Step S4), amplified by the amplifier 9 (Step S5), taken into the signal processing unit 6 and stored in the memory (Step S4). S6). The reflected wave signal taken into the signal processing unit 6 is subjected to signal processing so that it can be displayed on the waveform display unit 7, and then stored in the memory (step S7). The signal-processed reflected wave signal is displayed on the waveform display unit 7 together with the incident wave signal (step S8). In the example shown in FIG. 5, there are three waveforms displayed on the waveform display unit 7, that is, an incident wave, a branched portion reflected wave, and a branched portion multiple reflected wave. ) Is displayed.
The display waveform can be arbitrarily set as required.

  Next, after counting the number of measurements (step S9), it is determined whether the number of measurements is a predetermined number (step S10). In this embodiment, since the predetermined number of times is set to four, when the first measurement is completed, the process waits until an instruction to restart the measurement is given. When the movable portion 42 of the variable pipe length mechanism 4 is moved by ΔL to the next measurement position and measurement start is instructed (step S11), the process returns to step 1 and the processes of steps 1 to 9 are performed. Until the number of measurements reaches four, the movable portion 42 is sequentially moved by ΔL, a restart instruction is performed, and the processing of steps 1 to 9 is repeated.

  When steps 1 to 9 are repeated, the processing of steps 6 to 9 is performed according to the number of repetitions as follows.

  In step S6, the measured reflected wave signal is stored in another place in time series according to the number of times of processing.

  In step S7, the waveform of the measured reflected wave signal is corrected by the amount of movement ΔL to 3ΔL of the movable portion 42 to match the reference position, and the result of this process is separated in time series according to the number of times of processing. Is stored.

  Processing for matching the reference positions will be described with reference to FIG. When the reference position matching process is not performed as in the prior art, the reflected wave is displayed on the waveform display unit 7 as shown by the dotted lines in FIGS. 5B to 5D. When the reference position matching process is performed, the reflected wave is displayed on the waveform display unit 7 as shown by the solid lines in FIGS. That is, the reflected wave signal from the second investigation is shifted forward by a time corresponding to the amount of movement of ΔL. As a result, the start position of the reflected wave signal at the second branch portion is matched with the reference position of the reflected wave signal at the first branch portion. On the other hand, the second multiple reflected wave signal starts with a delay of 2ΔL from the reference position of the first multiple reflected wave signal, so even if it is shifted forward by a time corresponding to the amount of movement of ΔL, Therefore, the start is delayed by ΔL from the reference position of the multiple reflected wave signal. Next, the reflected wave signal from the third survey is shifted forward by a time corresponding to the movement of 2ΔL, and the reflected wave signal from the fourth survey is shifted forward by a time corresponding to the movement of 3ΔL. The start position of the reflected wave signal at each branch portion coincides with the first reference position, but the start position of each of the multiple reflected wave signals is delayed from the first reference position.

  If it is determined in step S10 that the number of measurements has reached a predetermined number, a process of adding the reflected wave signal that has been processed to match the reference position is performed and stored in the memory of the signal processing unit 6 (step S12). The added reflected wave signal is displayed on the waveform display unit 7 as shown in FIG. 5E (step S13). As is clear from FIG. 5 (e), the reflected wave signal of the branching part is added four times by matching the reference position of the reflected wave signal of each measurement count. The multiple reflected wave signal is a waveform signal that clearly differs from the reflected wave signal added by the branching unit without being added four times due to the difference in the reference position of the reflected wave signal of each measurement count. Therefore, it is possible to easily check the pipe line state.

  This completes the survey. In addition, the pipe length variable mechanism 4 may be attached to the pipe 1 in the most extended state and the investigation may be started, and the pipe length variable mechanism 4 may be gradually contracted to perform the same operation.

According to the sound wave type pipe survey system 10 of the present embodiment, the sound generation unit 2 that enters the sound wave signal into the pipe line of the pipe 1 to be investigated, the sensor unit 3 that measures the reflected wave signal of the incident sound wave signal, A signal processing unit 6 for processing the reflected wave signal obtained by the sensor unit 3, and the signal processing unit 6 includes a multiple reflected wave signal generated between the sound generating unit 2 and the reflection point, and a reflection point. Multiple reflected wave identifying means 61 for performing processing for enlarging the difference in the magnitude of the reflected wave signals of the reflected wave signals, it is possible to accurately identify the actual reflected wave signal and the multiple reflected wave signal. The number and position can be easily detected.

  The sonic type pipe survey system 10 includes a variable pipe length mechanism 4 that is attached to the end of the pipe 1 with the sound generation unit 1 and the sensor unit 3 attached, and changes the measurement pipe length. The variable path length mechanism 4 includes a fixed portion 42 attached to the end of the pipe 1 and a movable portion 42 movably attached to the fixed portion 41, and the signal processing unit 6 moves the movable portion 42. Each reflected wave signal obtained by performing the incidence of the sound wave signal by the sound generating unit 2 and the measurement by the sensor unit 3 at a plurality of positions is corrected by the amount of movement of the movable unit 42 to match the reference position and are added. The multi-reflected wave discriminating means 61 is provided for performing processing for enlarging the difference between the reflected wave signal from the reflection point and the multiple reflected wave signal generated between the sound generating unit 2 and the reflection point. The path length can be changed easily and is simple and accurate. It is possible to perform a good survey.

  In addition, since the fixed portion 41 can be hermetically fixed to the end portion of the pipe 1 and the movable portion 42 is installed so as to be airtightly movable to the fixed portion 41, the investigation of the pipe 1 in the gas use state is performed. Can be easily performed.

  The fixed portion 41 includes a fixed cylindrical member 41a disposed outside the end portion of the pipe 1, and the movable portion 42 is disposed so as to be slidable in the axial direction by engaging with the outer side of the fixed cylindrical member 41a. Since the movable cylindrical member 42a is provided, the length of the pipe line at the time of measurement can be varied with a simple structure while suppressing the protruding amount from the tip of the pipe 1.

  Further, since the sliding portion of the movable cylindrical member 42 having an inner diameter larger than the inner diameter of the pipe 1 is provided with a step closing member 42c that covers the stepped portion 42e formed by projecting from the opening end of the pipe over the movable range, Multiple reflections by the portion 42e can be prevented. Since the step closing member 42c is formed of a thin cylindrical member extending from the movable cylindrical member 42 to the inner surface of the end portion of the pipe 1, it is possible to reliably prevent multiple reflections by the step portion 42e with a simple structure. Can do.

  Furthermore, according to the pipe survey method using the sonic pipe survey system of the present embodiment, the sound generation unit 2 that enters the sound wave signal into the pipe line of the pipe 1 to be investigated, and the reflected wave signal of the incident sound wave signal In a sonic pipe survey system 10 including a sensor unit 3 for measurement and a signal processing unit 6 for processing a reflected wave signal obtained by the sensor unit 3, the sound generation unit 2 and the sensor unit 3 are arranged at a reference position. The sound wave signal is incident on the pipe line of the pipe 1 and the reflected wave signal is measured, and the sound generation unit 2 and the sensor unit 3 are arranged at a position moved by a predetermined amount from the reference position, and the sound wave signal is sent to the pipe line of the pipe 1. Multiplex that occurs between the sound generating unit 2 and the reflection point based on the reflected wave signal measured at the reference position and the reflected wave signal measured at a position moved by a predetermined amount from the reference position. From reflected wave signal and reflection point Since the signal processing unit is controlled to perform the process of enlarging the difference from the reflected wave signal, the actual reflected wave signal and the multiple reflected wave signal can be accurately identified, and the number and position of the reflection points Can be easily detected.

It is a block diagram of the sonic type piping investigation system of one Example of this invention. It is a partial cross section side view of the state where pipe line variable mechanism 4 in this example was attached to piping 1. FIG. 3 is an enlarged view of a main part of FIG. 2. It is an operation | movement flowchart of the sonic type piping investigation system of a present Example. FIG. 5 is a waveform diagram corresponding to FIG. 4.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Pipe, 1a ... Branch part, 1b ... Pipe end part, 2 ... Sound generation part, 3 ... Sensor part, 4 ... Pipe length variable mechanism, 5 ... Signal generator, 6 ... Signal processing part, 7 ... Waveform display part 8, 9 ... Amplifier, 10 ... Sonic pipe survey system, 41 ... Fixed part, 41a ... Fixed cylindrical member, 41b ... Fixed nut, 42 ... Movable part, 42a ... Movable cylindrical member, 42c ... Step blocking member, 42d ... sealing material, 42e ... step portion, 61 ... multiple reflected wave identifying means.

Claims (8)

A sound generation unit that inputs a sound wave signal, which is a periodic signal, into a pipe line of a pipe to be investigated,
A sensor unit for measuring a reflected wave signal of an incident sound wave signal;
A signal processing unit for processing the reflected wave signal obtained by the sensor unit ;
A variable pipe length mechanism that is attached to an end of the pipe in a state in which the sound generation part and the sensor part are mounted, and changes a measurement pipe length ;
The variable pipe length mechanism is a movable portion that is movably attached to the fixed portion in a state in which the sound generating portion and the sensor portion are mounted, and that changes the measurement pipe length while being attached to the end portion of the pipe. With
The signal processing unit moves the movable unit to determine the start position of each reflected wave signal obtained by performing the incidence of the sound wave signal by the sound generation unit and the measurement by the sensor unit at a plurality of positions. only movement amount correction to with match the reference position, by adding the respective reflected wave signal after correction, the reflected wave signal from the multiple reflection wave signal and reflection points occurring between the reflection point and the sound generator And a multiple reflected wave identifying means for performing processing for expanding the difference in magnitude between the reflected wave signal and the waveform of the reflected wave signal from the reflection point. Piping survey system. 2. The sonic piping inspection system according to claim 1, wherein the sonic signal is a sine wave signal of one cycle, and a delay time of a start position of the reflected wave signal from the reflection point due to the movement of the movable portion is the sonic signal. And a waveform of the added multiple reflected wave signal different from that of the sine wave . A sounding part that makes a sound wave signal incident on the pipe of the pipe to be investigated,
A sensor unit for measuring a reflected wave signal of an incident sound wave signal;
A signal processing unit for processing the reflected wave signal obtained by the sensor unit;
A pipe length variable mechanism that is attached to an end of the pipe in a state in which the sound generation section and the sensor section are mounted, and changes a measurement pipe length;
The variable pipe length mechanism includes a fixed portion attached to an end portion of the pipe and a movable portion movably attached to the fixed portion, and the fixed portion is airtightly fixed to the end portion of the pipe. And making the movable part airtightly movable to the fixed part ,
The signal processing unit moves each of the reflected wave signals obtained by moving the movable unit and performing the incidence of the sound wave signal by the sound generation unit and the measurement by the sensor unit at a plurality of positions. Only to correct and match the reference position and add, and to enlarge the difference in magnitude between the multiple reflected wave signal generated between the sounding portion and the reflection point and the reflected wave signal from the reflection point A sonic piping survey system characterized by comprising multiple reflected wave identification means for performing .   4. The acoustic pipe survey system according to claim 3, wherein the fixed portion includes a fixed cylindrical member disposed outside an end portion of the pipe, and the movable portion engages outside the fixed cylindrical member. A sonic pipe survey system comprising a movable cylindrical member slidably disposed in the axial direction.   5. The step-blocking system in which the sliding portion of the movable cylindrical member having an inner diameter larger than the inner diameter of the piping covers the step formed by projecting from the opening end of the piping over the movable range. A sonic piping survey system comprising a member.   The sonic type pipe survey system according to claim 5, wherein the step closing member is formed of a thin cylindrical member extending from the movable cylindrical member to an inner surface of an end of the pipe. Piping survey system. A sound generation unit that inputs a sound wave signal that is a periodic signal to a pipe line of a pipe to be investigated, a sensor unit that measures a reflected wave signal of the incident sound wave signal, and a reflected wave signal obtained by the sensor unit A signal processing unit to be processed, a fixed unit attached to an end of the pipe, a movable unit attached to the fixed unit in a state where the sound generation unit and the sensor unit are mounted and movable to change the measurement pipeline length In a pipe survey method using a sonic pipe survey system having a variable pipe length mechanism for changing the measurement pipe length ,
The sound generation unit and the sensor unit are arranged at a reference position, and a sound wave signal is incident on the pipe line of the pipe and the reflected wave signal is measured,
Move the movable part and perform the incidence of the sound wave signal by the sounding part and the measurement of the reflected wave signal by the sensor part at a plurality of positions ,
It causes the start position before Symbol meter measuring and the reflected wave signals match the correction to the reference position by the movement amount of the movable portion, and adds the reflected wave signal after correction, a reflecting point and the sound generator multiple reflected wave signal and said reflected wave signal waveform and processing the signal to be the difference in the waveform of the multiplexed reflected wave signal from the reflection point with to expand the difference between the reflected wave signal from the reflection point occurs between A pipe survey method using a sonic pipe survey system, characterized in that it is performed in a processing section. The pipe survey method using the acoustic wave pipe survey system according to claim 7, wherein the sound wave signal is a sine wave signal of one cycle, and the delay time of the start position of the multiple reflected wave signal due to movement of the movable part is A pipe survey method using a sonic pipe survey system, characterized by shortening the time of one cycle of a sine wave signal of a sonic signal and making the waveform of the added multiple reflected wave signal different from a sine wave .

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