JP5661025B2 - In-tube ultrasonic flaw detector - Google Patents

Description

  The present invention relates to an in-pipe type ultrasonic flaw detector that detects the presence or absence of a tube wall of a tube to be inspected with an ultrasonic probe inserted into the tube to be inspected. Specifically, the measurement position of a received echo signal is measured. It is possible.

  2. Description of the Related Art Conventionally, an in-tube insertion type ultrasonic flaw detector has been used to detect an abnormality of a tube by nondestructive inspection. For example, a pipe such as a boiler tube attached to a boiler of a thermal power plant passes high-temperature and high-pressure steam inside, and therefore it is necessary to inspect the pipe wall for scratches, cracks, thinning, and the like.

  In an in-pipe insertion type ultrasonic flaw detector, an ultrasonic probe inserted into a pipe oscillates ultrasonic waves toward the pipe wall and receives an echo signal, and a voltage of a pulse waveform with respect to the sensor part. A pulse generator / receiver for receiving an echo signal via the sensor unit, sending a pulse signal in the pulse generator / receiver unit, and writing an echo signal to the storage unit And the like, a control unit that controls power, a battery and a power supply circuit that supplies power to each component device, and an alignment jig that holds the ultrasonic probe almost at the center in the tube (detailed configuration of these devices) (See Patent Document 2).

  Pressurized water is supplied into the inspection tube by a water pump, an ultrasonic probe is inserted into the inspection tube, and moves in the inspection tube by a water flow. The ultrasonic probe oscillates toward the tube wall while moving in the tube to be inspected, and receives echo signals reflected from the tube inner surface and the tube outer surface. From the time difference of the echo signal and the waveform of the echo signal, the wall thickness and scratches of the tube wall are measured.

  In Patent Document 1, a self-propelled device and a photoelectric conversion means that captures light projected from the tube end side and converts it into electric energy are provided in an ultrasonic probe inserted into the tube. An ultrasonic flaw detector that does not require a cable connected to an ultrasonic probe is disclosed for extracting detection data or moving an ultrasonic probe. Similarly, Patent Document 2 discloses an in-pipe insertion type ultrasonic flaw detector that eliminates the need for the cable and moves the ultrasonic probe with pressurized water supplied by a water pump.

Description and drawings of Japanese Utility Model Publication No. Sho 63-38061 JP 2009-229451 A

  Conventionally, in the ultrasonic probe to which the cable is connected, the measurement position is calculated from the transmission amount of the cable. However, conventional detection methods cannot be employed with an ultrasonic probe to which a cable is not connected, such as the in-tube insertion type ultrasonic flaw detector disclosed in Patent Documents 1 and 2. Therefore, as another detection method, for example, a part having a characteristic waveform of an ultrasonic echo signal, such as a bend part (bent part) or a butt weld part of a boiler tube, is specified, and a measurement position is determined from a time difference from the part. Has been determined.

  That is, as shown in FIG. 8, for example, pressurized water w is supplied from a pressurized water supply pipe 102 by a water pump 104 to a test pipe 100 such as a boiler tube. The ultrasonic probe 106 inserted into the test tube 100 moves in the test tube 100 on the water flow a formed by the pressurized water w, oscillates ultrasonic waves while moving, receives an echo signal, Inspect the tube wall. Since the echo signal received by the ultrasonic probe 102 has a characteristic waveform at the bent portion 100a of the tube 100 to be inspected, the bent portion 100a is specified by receiving the characteristic waveform, and this waveform is received. The measurement position of the other pipe wall is determined from the time difference from the measured time.

  In the finned tube, the echo signal shows a characteristic waveform at the filled portion. Since the fin pitch interval is equal, the measurement position can be obtained by determining the portion with fins from the characteristic waveform and counting the number of fins. However, since the moving speed of the ultrasonic probe moving with the water flow flowing in the test tube is not constant, there is a problem that an error occurs in the position information.

  Patent Document 2 discloses a measurement position calculation means in which a sound wave transmitter is provided at each end of the tube to be inspected, and a sound wave receiver is provided at the front end and the rear end of the ultrasonic probe. In this calculation means, sound waves are simultaneously transmitted from both sound wave transmitters, and the position in the tube axis direction of the ultrasonic probe is obtained from the time difference between sound waves received by both sound wave receivers. However, this means has a problem that it is relatively expensive because it is necessary to attach a sound wave transmitter and a sound wave receiver.

The present invention is seen paragon challenges in the prior art, the tube insertion type ultrasonic flaw detection apparatus equipped with an ultrasonic probe moved in pressurized water supplied to the inspection tube, in a simple and low-cost means, measuring The purpose is to be able to determine the position.

In order to achieve this object, an intraductal ultrasonic inspection device according to the present invention includes an acceleration sensor and a memory in an ultrasonic probe, and stores waveform information of an echo signal and acceleration information detected by the acceleration sensor in the memory. I try to remember it.
And in the arithmetic unit, identify the part that produces a characteristic waveform such as a bent part or a welded part of the tube to be inspected from the waveform information of the echo signal, based on the pipe wall part that produced the characteristic waveform , Data from the acceleration sensor is integrated over time to determine the velocity of the ultrasonic probe, and further integrated over time to calculate the measurement position of the echo signal . The measurement result linked to the measurement position of the tube to be inspected is obtained at a tube wall portion located between the tube wall portions where the characteristic waveform is generated, and further, the ultrasonic probe In addition to measuring the position of the ultrasonic probe by the acceleration sensor, a linear body connected to the linear tube and a linear body feeding device that is provided outside the tube to be inspected and feeds out the linear body. It is characterized by using the position measurement by the linear body feeding device together.
The tube wall portion where the characteristic waveform is generated is a bend portion or a welded portion. As shown in FIG. 8, a straight pipe portion or a gentle bent portion between these characteristic waveform portions can be obtained based on the position of the characteristic waveform portion.

  The speed of the ultrasonic probe is obtained by time-integrating the acceleration information with an arithmetic device. Next, the obtained speed is further integrated over time to obtain the distance from the tube wall portion where the characteristic waveform is generated. In this way, the measurement position can be obtained using the characteristic waveform portion as a base point. The arithmetic unit may be built in the ultrasonic probe or provided outside the tube to be inspected.

In this invention, in addition to the said structure, it is good to provide the feed speed control apparatus which controls the linear body feed speed of the said linear body feed apparatus, and to send out a linear body at a fixed speed with a feed speed control apparatus. The moving amount of the ultrasonic probe is equal to the feeding amount of the linear body. Therefore, the movement amount of the ultrasonic probe can be obtained from the product of the linear body feed speed and the time required for the feed. From this amount of movement, the measurement position of the tube to be inspected can be obtained. Thus, the measurement position can be accurately obtained by using the position measurement by the acceleration sensor and the position measurement using the linear body in combination.

Te present invention odor may be provided with a feed amount measuring device for measuring the feed amount of the linear body. Thereby, the movement amount of the ultrasonic probe can be obtained from the feed amount of the linear body. By using the position measurement by the acceleration sensor and this measurement method in combination, the measurement position can be obtained accurately.

  In the present invention, the arithmetic unit may be provided outside the tube to be inspected, and the linear body may be constituted by a lead wire that connects the arithmetic unit and the memory. As a result, the measurement position can be obtained by feeding the linear body, and the waveform information and acceleration information of the echo signal stored in the memory are transferred to the arithmetic unit provided outside the test tube via the lead wire. Can send. Therefore, the measurement result can be obtained online by the arithmetic device during the measurement by the ultrasonic probe.

According to the present invention, an acceleration sensor and a memory are incorporated in the ultrasonic probe, and waveform information of the echo signal and acceleration information obtained by the acceleration sensor are stored in the memory, and the waveform of the echo signal is stored in the arithmetic unit. Since the information and acceleration information are matched and the measurement position is calculated from the acceleration information using the position of the tube wall part where the characteristic waveform of the echo signal is generated as a reference, an ultrasonic probe that is not connected to the external device with a cable is used. Even with a touch element, the measurement position can be obtained by simple and low-cost means.
In addition to the measurement of the position of the ultrasonic probe by the acceleration sensor, the measurement position can be accurately obtained by using the position measurement by the linear body feeding device together.

It is a whole block diagram of 1st Embodiment of this invention apparatus. It is a block diagram of the signal processing system of a 1st embodiment. It is a flowchart which shows the signal processing procedure of 1st Embodiment. It is a block diagram of the signal processing system of 2nd Embodiment of this invention apparatus. It is a whole block diagram of 3rd Embodiment of this invention apparatus. It is a block diagram of the signal processing system of 3rd Embodiment. It is a whole block diagram of 4th Embodiment of this invention apparatus. It is explanatory drawing which shows the conventional measurement position detection method.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.

(Embodiment 1)
A first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, a pressurized water supply pipe 12 is connected to the pipe to be inspected 10 in order to inspect the pipe wall of the pipe to be inspected 10 such as a boiler tube for scratches, cracks, thinning, and the like. Pressurized water w is supplied into the test tube 10 by the water pump 14 provided in the pressurized water supply tube 12, and a water flow a is formed inside the test tube 10. An ultrasonic probe 20 is inserted into the test tube 10, and the ultrasonic probe 20 moves inside the test tube 10 by the water flow a.

  In the ultrasonic probe 20, a sensor storage unit 22 and an acceleration sensor storage unit 24 are connected via a flexible shaft 26 formed of a coil spring or the like. The flexible shaft 26 incorporates lead wires connected to the sensor housing portion 22 and the acceleration sensor housing portion 24. A tip guide 28 is provided via a flexible shaft 26 at the tip of the ultrasonic probe 20 by the lead wire and the sensor housing portion 22 and the acceleration sensor housing portion 24. In addition, an alignment jig 30 is provided on the flexible shaft 26 before and after the sensor housing portion 22 so as to position the ultrasonic probe 20 substantially at the center inside the test tube 10.

  The sensor storage unit 22 is provided with a transducer or the like made of a piezoelectric element that oscillates and receives ultrasonic waves, and a pulse waveform voltage is applied to the sensor unit 32 to transmit pulsed ultrasonic waves. In addition, a pulse generation / reception unit 34 that receives an echo signal via the sensor unit 32 is housed. The acceleration sensor storage unit 24 controls the acceleration sensor 36 that measures the acceleration of the ultrasound probe 20, the transmission of pulse signals in the pulse generation / reception unit 34, and the writing of echo signals to the memory 38. The unit 40 and a battery 42 for supplying power to each component device are accommodated.

  As shown in FIG. 2, the echo signal received by the pulse generator / receiver 34 and the acceleration of the ultrasonic probe 20 detected by the acceleration sensor 36 are converted into a digital signal by the AD converter 44 and stored in the memory 38. Remembered.

  In this configuration, the operation procedure of this embodiment will be described with reference to FIG. The ultrasonic probe 20 transmits ultrasonic waves from the sensor unit 32 while moving inside the test tube 10 and receives echo signals reflected from the tube inner surface and the tube outer surface (S10). Further, while moving the test tube 10, the acceleration sensor 36 measures the acceleration of the ultrasonic probe 20 (S12). The echo signal data and the acceleration data obtained by the acceleration sensor 20 are converted into digital signals by the AD converter 30 (S14), and stored in the memory 38 as combination information linked on the time axis (S16).

  Next, after the inspection of the test tube 10 is finished, the ultrasonic probe 20 is taken out of the test tube 10 and the memory 38 is connected to the personal computer 46. Then, the CPU 48 built in the personal computer 46 measures the wall thickness and scratches of the tube wall from the time difference of the echo signal between the tube inner surface and the tube outer surface and the waveform of the echo signal (S18). In determining the measurement position, first, the CPU 48 specifies a part where a characteristic waveform is generated from the waveform data of the echo signal, such as a bent portion or a welded portion of the test tube 10 from the waveform data of the echo signal.

  Next, the CPU 48 obtains the velocity of the ultrasonic probe 20 by integrating the acceleration data over time (S20). Next, the obtained speed is further integrated over time to obtain the distance of the specific waveform portion from the characteristic waveform portion (S22). Then, from the combination information of the waveform data of the echo signal and the acceleration data, the measurement position of the test tube 10 corresponding to the specific waveform data is obtained from the acceleration data using the characteristic waveform portion as a reference (S24). In this way, the obtained measurement result of the tube wall (measurement result linked to the measurement position of the inspected tube 10) is displayed on the screen 50.

  According to the present embodiment, a measurement result linked to the measurement position of the test tube 10 can be obtained with the characteristic waveform portion as a reference. In addition, this can be achieved with a simple and low-cost means in which the acceleration sensor 36 is incorporated in the ultrasonic probe 20.

(Embodiment 2)
Next, a second embodiment of the device of the present invention will be described with reference to FIG. As shown in FIG. 4, the present embodiment has a configuration in which a CPU (arithmetic unit) is built in the control unit 40. The built-in CPU 52 obtains the measurement result of the tube wall from the echo signal from the combination information converted into the digital signal by the AD converter 44, and calculates the measurement position of the tube wall corresponding to the measurement result from the characteristic waveform portion. The calculation result is stored in the memory 38. After the inspection is completed, the memory 38 is connected to the personal computer 46, and the measurement result linked to the tube wall portion of the tube 10 to be inspected is read out and used by the personal computer. Other configurations are the same as those of the first embodiment.

  According to the present embodiment, the acquired data can be calculated by the built-in CPU 52 of the ultrasonic probe 20 and the measurement result linked to the measurement position can be obtained, so that no calculation device is required outside the tube 10 to be inspected. . Therefore, the external device configuration can be simplified.

(Embodiment 3)
Next, a third embodiment of the device of the present invention will be described with reference to FIGS. In FIG. 5, the pressurized water supply apparatus and the ultrasonic probe 20 inserted into the test tube 10 have the same configuration as that of the first embodiment. In the present embodiment, a winding sending device 60 is provided outside the test tube 10. The winding delivery device 60 is provided with a cylindrical rotary drum 64 fixed to a rotary shaft 62. A drive motor 66 is provided adjacent to the rotating shaft 62. A power transmission belt 68 is wound around the rotary shaft 62 and the output shaft 66a of the drive motor 46, and the rotary shaft 62 and the rotary drum 64 are rotated by the output shaft 66a.

  A winding 70 is wound around the rotating drum 64, and the tip of the winding 70 is connected to the rear end of the ultrasonic probe 20. By rotating the rotating drum 64 in the feeding direction or the taking-in direction of the winding 70, the moving direction and moving amount of the ultrasonic probe 20 can be controlled against the water flow a. The winding delivery device 60 is provided with a control device 72 that can control the speed of the rotating drum 64 and a display unit 74 that displays the moving speed of the winding 70 and the operating time of the rotating drum 64.

  In the present embodiment, the control device 72 controls the rotational speed of the rotating shaft 42 to be constant when the ultrasonic probe 20 inspects the inspected tube 10. Therefore, the position of the ultrasonic probe 20 in the inspection tube can be obtained from the product of the feed speed of the winding 50 and the operating time of the rotating drum 64. As shown in FIG. 6, after the inspection is completed, the memory 38 is connected to the personal computer 46, and the combination information is input from the memory 38 to the personal computer 46. In addition, the position data of the ultrasound probe 20 obtained by the control device 72 is converted into a digital signal by the AD converter 76 and then input to the personal computer 46. By averaging the combination information input from the memory 38 and the position data input from the control device 72 by the personal computer 46, the measurement position can be calculated with high accuracy.

  According to this embodiment, in addition to the position measurement of the ultrasonic probe 20 by the acceleration sensor 36 similar to the first embodiment, the position measurement of the ultrasonic probe 20 by the winding sending device 60 is used in combination. Thus, the position of the ultrasonic probe 20 can be accurately measured.

(Embodiment 4)
Next, a fourth embodiment of the device of the present invention will be described with reference to FIG. In this embodiment, in addition to the configuration of the third embodiment, an encoder 76 for measuring the amount of winding 70 in and out is attached to the winding sending device 60. Then, the measurement value of the encoder 76 is additionally displayed on the display unit 74. Other configurations are the same as those of the third embodiment.

  According to the present embodiment, in the calculation process in the personal computer 46, it is possible to perform a calculation that further considers the measurement value of the encoder 76, as compared with the third embodiment. Therefore, the measurement position linked to the measurement result can be obtained with higher accuracy.

  As a modification of the fourth embodiment, the winding 70 is replaced with a cable with a built-in lead wire, and the control unit 40 of the ultrasonic probe 20 and the CPU built in the control device 72 are electrically connected. It is good to do so. Thus, the combination information stored in the memory 38 can be sent to the CPU in the control device 72 during the inspection by the ultrasonic probe 20. Therefore, it is possible to obtain the measurement result of the inspected tube 10 and the measurement position linked to the measurement result online during the inspection.

  According to the present invention, in a tube insertion type ultrasonic flaw detector for detecting the presence / absence of an inspection tube such as a boiler tube, the measurement position is obtained while measuring the presence / absence of the tube wall with a simple and low-cost means. be able to.

DESCRIPTION OF SYMBOLS 10 Test pipe 12 Pressurized water supply pipe 14 Water pump 20 Ultrasonic probe 22 Sensor storage part 24 Acceleration sensor storage part 26 Flexible shaft 28 Tip guide 30 Alignment jig 32 Sensor part 34 Pulse generation / reception part 36 Acceleration sensor 38 Memory 40 Control unit 42 Battery 44 AD converter 46 Personal computer 48 CPU
50 screen 52 built-in CPU
Reference Signs List 60 winding device 62 rotating shaft 64 rotating drum 66 drive motor 66a output shaft 68 power transmission belt 70 winding 72 control device 74 display unit 76 encoder a water flow w pressurized water

Claims (4)

A pressurized water supply device that supplies pressurized water to the inside of the tube to be inspected to form a water flow, and is inserted into the tube to be inspected and moves by the water flow, and the ultrasonic waves oscillate toward the tube wall of the tube to be inspected. An ultrasonic probe having a sensor unit that receives an echo signal reflected from the echo signal, and detecting whether there is an abnormality in the tube wall from the waveform of the echo signal.
An acceleration sensor provided in the ultrasonic probe;
A memory that is provided in the ultrasonic probe and stores waveform information of the echo signal and acceleration information obtained by the acceleration sensor;
A part that generates a characteristic waveform such as a bent part or a welded part of a pipe to be inspected is specified from the waveform information of the echo signal, and the data from the acceleration sensor is based on the pipe wall part that generated the characteristic waveform. Bei example and a calculation unit for calculating a measuring position of the echo signals and further time integration obtains the speed of the time integral to the ultrasound probe, and
The measurement result linked with the measurement position of the tube to be inspected is configured to be obtained at a tube wall portion located between the tube wall portions where the characteristic waveform is generated,
A linear body connected to the ultrasonic probe; and a linear body feeding device that is provided outside the tube to be inspected and feeds out the linear body, the ultrasonic sensor using the acceleration sensor. A tube insertion type ultrasonic flaw detector characterized by using in combination with the position measurement by the linear body feeding device in addition to the position measurement of the tentacle. A feed rate controller for controlling the linear body feed speed of the linear body feeding device,
The in-pipe insertion type ultrasonic flaw detector according to claim 1, wherein the linear body is sent out at a constant speed by the feed speed control device. Tube insertion type ultrasonic flaw detection apparatus according to claim 1 or 2, characterized in that it comprises a feed amount measuring device for measuring the feed amount of the linear body. The in-pipe insertion according to claim 2 or 3, wherein the arithmetic unit is provided outside a tube to be inspected, and the linear body is constituted by a lead wire that connects the arithmetic unit and the memory. Type ultrasonic flaw detector.

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