Ultrasonic flaw detection method and apparatus

Abstract

To provide an ultrasonic flaw detection method capable of detecting the flaw of a specimen by more easily changing an inspection place, and an ultrasonic flaw detector.SOLUTION: An ultrasonic flaw detection method according to the present invention includes relatively moving a test object and an ultrasonic transceiver configured to transmit an ultrasonic wave to the test object and receive an ultrasonic wave propagating through the test object, transmitting and receiving the ultrasonic wave by the ultrasonic transceiver at a plurality of detection parts at each of a plurality of different movement amounts of the test object with respect to the ultrasonic transceiver, shifting the plurality of received ultrasonic waves to be in phase, and performing ultrasonic flaw detection based on the plurality of ultrasonic waves in phase.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic flaw detection method and an ultrasonic flaw detection device for detecting defects in a test object using ultrasonic waves. [Background technology]

[0002] Ultrasonic flaw detection methods and devices for detecting defects such as cracks, cavities, inclusions, recesses, and thinning in a test object using ultrasonic waves are used in a variety of cases because they enable non-destructive testing of the test object. One such method is an ultrasonic flaw detection method using guided waves, which is disclosed in Patent Document 1, for example.

[0003] The inspection method using guided waves disclosed in Patent Document 1 is a method of generating a guided wave that propagates longitudinally through a rod-shaped or tubular object to be measured, detecting reflected waves of the guided wave, and inspecting the object based on the reflected waves, in which: (A) an AC voltage is applied to a coil to generate the guided wave in the object to be measured, and reflected waves of the guided wave reflected at defective portions are detected at multiple detection portions separated by a predetermined distance and stored; (B) the multiple reflected waves stored in (A) are shifted and aligned to the same phase and stored; and (C) the multiple reflected waves aligned to the same phase in (B) are multiplied together. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-88118 Summary of the Invention [Problem to be solved by the invention]

[0005] The inspection method disclosed in Patent Document 1 uses a single transmitting sensor on the inspection object and multiple receiving sensors at each of the multiple inspection points to detect the reflected wave at multiple detection points spaced a predetermined distance apart (see, for example, paragraph

[0027] and Figure 2 of Patent Document 1). Another approach uses a single transmitting sensor on the inspection object and multiple receiving sensors that are repositioned at each of the multiple detection points to detect the reflected wave at multiple detection points spaced a predetermined distance apart (see, for example, paragraph

[0042] and Figure 9 of Patent Document 1). However, repositioning the receiving sensor at each of the multiple detection points requires measuring the distance between each of the detection points and the receiving sensor, and then measuring the distance between the receiving sensor and the transmitting sensor after installing the receiving sensor at each detection point, which requires labor and time. Furthermore, changing the inspection point (inspection position) on the inspection object requires changing the position of at least the transmitting sensor, which also requires labor and time. This poses a significant problem when performing inspection on a production line.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ultrasonic flaw detection method and an ultrasonic flaw detection device that can more easily change the inspection location to detect defects in a test object. [Means for solving the problem]

[0007] After extensive investigation, the inventors have found that the above object can be achieved by the present invention described below. That is, an ultrasonic flaw detection method according to one aspect of the present invention comprises: an ultrasonic transmission and reception processing step of transmitting ultrasonic waves to an object to be inspected, moving an ultrasonic transmission and reception unit that receives the ultrasonic waves propagating through the object relative to the object, and transmitting and receiving the ultrasonic waves by the ultrasonic transmission and reception unit at a plurality of detection sites at a plurality of different movement amounts of the object relative to the ultrasonic transmission and reception unit; a phase processing step of shifting and aligning the plurality of ultrasonic waves received in the ultrasonic transmission and reception processing step to have the same phase; and a flaw detection processing step of performing ultrasonic flaw detection based on the plurality of ultrasonic waves whose phases have been aligned in the phase processing step. Preferably, in the above ultrasonic flaw detection method, the object to be inspected is a member that is elongated in one direction and moves along the one direction.

[0008] In this ultrasonic flaw detection method, ultrasonic waves are transmitted and received at multiple detection locations by moving the ultrasonic transmitter / receiver unit and the specimen relative to each other, and since the relative movement changes the placement position of the ultrasonic transmitter / receiver unit, no additional labor or time is required to change the placement position, and defects in the specimen can be detected more easily by changing the inspection location.

[0009] In another aspect, in the above-mentioned ultrasonic flaw detection method, the ultrasonic transmitter / receiver transmits ultrasonic burst waves consisting of a plurality of time-sequential waves to the test object, and the flaw detection processing step calculates an arithmetic average result by adding and averaging the plurality of ultrasonic waves whose phases have been aligned in the phase processing step, and performs ultrasonic flaw detection based on the calculated arithmetic average result. Preferably, in the above-mentioned ultrasonic flaw detection method, the flaw detection processing step displays the arithmetic average result as the ultrasonic flaw detection so that a user can detect defects. Preferably, in the above-mentioned ultrasonic flaw detection method, the flaw detection processing step compares the arithmetic average result with a preset threshold (defect determination threshold) to detect defects as the ultrasonic flaw detection.

[0010] When high-frequency ultrasonic waves are used as burst wave ultrasonic waves, ultrasonic waves corresponding to multiple modes are generated due to the superposition of the ultrasonic waves. If these are added as they are, the waveform of the ultrasonic waves in the mode to be detected cannot be recognized. Therefore, by aligning the phase of the ultrasonic waveforms in the mode to be detected and then performing averaging, the waveform of the ultrasonic waves in the mode to be detected becomes relatively prominent, and the waveforms of ultrasonic waves in other modes become relatively less visible. As a result, defects can be detected more easily.

[0011] In another aspect, in the ultrasonic flaw detection method described above, the ultrasonic transmitter / receiver transmits ultrasonic waves of a burst wave consisting of a plurality of temporally consecutive waves to the test object, and the flaw detection processing step obtains a multiplication average result by multiplying and averaging the plurality of ultrasonic waves whose phases have been aligned in the phase processing step, and performs ultrasonic flaw detection based on the obtained multiplication average result. Preferably, in the ultrasonic flaw detection method described above, the flaw detection processing step displays the multiplication average result as the ultrasonic flaw detection so that a user can detect defects. Preferably, in the ultrasonic flaw detection method described above, the flaw detection processing step compares the multiplication average result with a preset threshold (defect determination threshold) to detect defects as the ultrasonic flaw detection.

[0012] In this ultrasonic flaw detection method, by obtaining a multiplication average result instead of an arithmetic average result, defects can be easily detected, similar to the case of an arithmetic average result.

[0013] In another aspect, in the ultrasonic flaw detection method described above, the ultrasonic transmitting and receiving unit includes one ultrasonic probe that transmits and receives ultrasonic waves.

[0014] This provides an ultrasonic flaw detection method using one ultrasonic probe that transmits and receives ultrasonic waves.

[0015] In another aspect, in the above-mentioned ultrasonic flaw detection method, the ultrasonic transmitter / receiver unit includes a pair of first and second ultrasonic probes, the first ultrasonic probe transmits ultrasonic waves, and the second ultrasonic probe is positioned a predetermined distance from the first ultrasonic probe and receives ultrasonic waves.

[0016] This provides an ultrasonic flaw detection method using a pair of first and second ultrasonic probes.

[0017] In another aspect, the above-mentioned ultrasonic flaw detection method further includes a sound speed processing step of receiving the ultrasonic waves transmitted by the first ultrasonic probe with the second ultrasonic probe, thereby determining the propagation time of the ultrasonic waves from the time when the ultrasonic waves are transmitted by the first ultrasonic probe to the time when the ultrasonic waves are received by the second ultrasonic probe, and determining the sound speed of the ultrasonic waves in the test object based on the determined propagation time of the ultrasonic waves and the predetermined distance.

[0018] Such an ultrasonic flaw detection method further includes a sound velocity processing step, so that the sound velocity of the test object can be actually measured, the sound velocity can be optimized according to the test object, and the sound velocity can be customized according to the test object.

[0019] In another aspect, in the ultrasonic flaw detection method described above, the test object moves in one predetermined direction.

[0020] Such an ultrasonic flaw detection method can be used to detect flaws in a material (semi-finished product) being manufactured or a product manufactured from the material, in a manufacturing line where products are manufactured while the material is being moved.

[0021] In another aspect, in the ultrasonic flaw detection method described above, the test object is stationary during flaw detection, and the ultrasonic transmitter / receiver moves along a predetermined direction relative to the test object.

[0022] This provides an ultrasonic flaw detection method in which an ultrasonic transmitting / receiving unit is moved relative to an immobile test object (a test object that does not move).

[0023] In another aspect, in the above-mentioned ultrasonic flaw detection method, the phase processing step, when any one of the plurality of detection locations is used as a reference detection location, calculates an adjusted movement amount based on the reference detection location for each of the plurality of movement amounts based on the relative movement speed between the ultrasonic transmission / reception unit and the subject and the relative movement time from the time of transmission and reception when the ultrasonic wave was transmitted and received at the reference detection location, calculates an adjusted movement time by doubling the calculated adjusted movement amount and dividing it by the sound speed of the ultrasonic wave, and aligns each of the plurality of ultrasonic waves received in the ultrasonic transmission / reception processing step to the same phase by each of the calculated adjusted movement times.

[0024] This type of ultrasonic flaw detection method calculates the amount of adjustment movement based on a reference detection location to determine the adjustment movement time.By monitoring the time points of each transmission and reception at each detection location, multiple ultrasonic waves can be shifted and aligned to the same phase, eliminating the need for measuring equipment (measurement sensors) to measure the detection location.

[0025] Another aspect of the present invention provides an ultrasonic flaw detection device comprising an ultrasonic transmitter / receiver unit that transmits ultrasonic waves to a test object and receives ultrasonic waves propagating through the test object; a moving unit that moves the ultrasonic transmitter / receiver unit and the test object relatively; an ultrasonic transmitter / receiver processing unit that moves the ultrasonic transmitter / receiver unit and the test object relatively using the moving unit and causes the ultrasonic transmitter / receiver unit to transmit and receive the ultrasonic waves at a plurality of detection sites at each of a plurality of different movement amounts on the test object relative to the ultrasonic transmitter / receiver unit; a phase processing unit that shifts and aligns the plurality of ultrasonic waves received by the ultrasonic transmitter / receiver unit at the plurality of detection sites to have the same phase; and a flaw detection processing unit that performs ultrasonic flaw detection based on the plurality of ultrasonic waves whose phases have been aligned by the phase processing unit.

[0026] Such ultrasonic flaw detection devices transmit and receive ultrasonic waves at multiple detection locations by moving the ultrasonic transmitter / receiver unit and the specimen relative to each other, and since the relative movement changes the position of the ultrasonic transmitter / receiver unit, no additional labor or time is required to change the position, making it easier to change the inspection location and detect defects in the specimen. [Effects of the Invention]

[0027] The ultrasonic flaw detection method and ultrasonic flaw detection device according to the present invention can more easily change the inspection location to detect defects in the test object. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a block diagram showing the configuration of an ultrasonic flaw detection device according to an embodiment. [Figure 2] FIG. 2 is a diagram showing a schematic configuration of a die wire drawing device using the ultrasonic flaw detector. [Figure 3] 3A and 3B are diagrams for explaining ultrasonic burst waves used in the ultrasonic flaw detection device. [Figure 4] 3A and 3B are diagrams for explaining transmission and reception of ultrasonic waves in the ultrasonic flaw detection device. [Figure 5] 4A and 4B are diagrams for explaining the process of synchronizing phases in the ultrasonic flaw detection device. [Figure 6] FIG. 10 is a diagram showing an example of an averaging result. [Figure 7] FIG. 10 is a diagram showing an example of a multiplication and averaging result. [Figure 8] FIG. 10 is a diagram showing a first comparative example as an example. [Figure 9] FIG. 10 is a diagram showing a second comparative example as an example. [Figure 10] 4 is a flowchart showing an operation of the ultrasonic flaw detection device. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. In addition, components with the same reference numerals in each drawing indicate the same components, and their description will be omitted as appropriate. In this specification, when referring to a general term, a reference numeral without a subscript is used, and when referring to an individual component, a reference numeral with a subscript is used.

[0030] The ultrasonic flaw detection method according to the embodiment includes an ultrasonic transmission / reception processing step, a phase processing step, and a flaw detection processing step. The ultrasonic transmission / reception processing step transmits ultrasonic waves to an object to be inspected, moves an ultrasonic transmitter / receiver unit that receives the ultrasonic waves propagating through the object relative to the object, and transmits and receives the ultrasonic waves by the ultrasonic transmitter / receiver unit at multiple detection locations on the object at multiple different movement amounts relative to the ultrasonic transmitter / receiver unit. The phase processing step shifts and aligns the multiple ultrasonic waves received in the ultrasonic transmission / reception processing step to the same phase. The flaw detection processing step performs ultrasonic flaw detection based on the multiple ultrasonic waves whose phases are aligned in the phase processing step. Below, the ultrasonic flaw detection method and the ultrasonic flaw detection device will be described in more detail, taking as an example an ultrasonic flaw detection device incorporating such an ultrasonic flaw detection method as used in a die wire drawing machine. While the ultrasonic flaw detection device will be described here as being used in a die wire drawing machine, the device in which the ultrasonic flaw detection device is used is not limited to a die wire drawing machine and may be any device. Furthermore, the ultrasonic flaw detection device may be used in the object itself, rather than in a production line.

[0031] FIG. 1 is a block diagram showing the configuration of an ultrasonic flaw detection device according to an embodiment. FIG. 2 is a diagram showing the schematic configuration of a die wire drawing device using the ultrasonic flaw detection device. FIG. 3 is a diagram for explaining ultrasonic burst waves used in the ultrasonic flaw detection device. The horizontal axis of FIG. 3 represents time. FIG. 4 is a diagram for explaining transmission and reception of ultrasonic waves in the ultrasonic flaw detection device. FIG. 4 shows the relationship between the ultrasonic transmission and reception unit Pb and the amount of movement of the test object WK when there are three detection sites for one detection location, with FIG. 4A showing the case of a first time point t1, FIG. 4B showing the case of a second time point t2, and FIG. 4C showing the case of a third time point t3. FIG. 5 is a diagram for explaining the phasing process in the ultrasonic flaw detection device. Fig. 5A schematically shows ultrasonic waves (received signals of ultrasonic waves) RW1 to RW3 received by the ultrasonic transmitter / receiver unit Pb when the transmission times t1 to t3 for each detection site are aligned at the origin 0, and Fig. 5B schematically shows the ultrasonic waves RW1 to RW3 when the phases are aligned. Fig. 6 is a diagram showing an example of an arithmetic average result. The horizontal axis of Fig. 6 is time, and the vertical axis is the magnitude of the arithmetic average (arithmetic average value). Fig. 7 is a diagram showing an example of a multiplicative average result. The horizontal axis of Fig. 7 is time, and the vertical axis is the magnitude of the multiplicative average (multiplicative average value).

[0032] 1 and 2, the ultrasonic flaw detection device 1000 in the embodiment includes an ultrasonic transmission / reception unit Pb, a plurality of pairs of drive rollers RL (RL-1 to RL-7) as an example of a moving unit, a control processing unit 1, an input unit 2, a display unit 3, an interface unit (IF unit) 4, and a storage unit 5. In the present embodiment, the ultrasonic flaw detection device 1000 is used in a die wire drawing device 2000 that draws a steel wire by a die wire drawing method.

[0033] This die wire drawing device 2000 includes a plurality of wire drawing dies DS (DS-1 to DS-7) and a plurality of pairs of drive rollers RL (RL-1 to RL-7).

[0034] The multiple wire drawing dies DS are arranged at predetermined intervals on the flat surface of the base BS. In this embodiment, the multiple wire drawing dies DS include seven wire drawing dies, numbered first through seventh, DS-1 (#1) through DS-7 (#7), in order to process a steel wire WK with a circular cross section into a steel wire WK with a flat cross section by drawing in seven passes. These first through seventh wire drawing dies DS-1 (#1) through DS-7 (#7) are arranged at predetermined intervals in this order on the base BS, and are formed so that the opening cross section of the die gradually changes from a circular shape to a flattened shape and the size (cross-sectional area) gradually decreases from the upstream side to the downstream side (gradually in the order of passes) in the movement direction (conveyance direction) DR of the steel wire WK.

[0035] Each of the multiple pairs of drive rollers RL includes a pair of rollers, and the pair of rollers holds a steel wire WK between them. The steel wire WK is drawn by rotation of the pair of rollers. In this embodiment, the number of pairs of drive rollers RL corresponds to the number of wire drawing dies DS, and the pairs of drive rollers RL are disposed downstream of each of the multiple wire drawing dies DS. In the example shown in FIG. 1 , the multiple pairs of drive rollers RL include seven pairs of first to seventh drive rollers RL-1 to RL-7. The first to seventh drive rollers RL-1 to RL-7 are disposed downstream of each of the first to seventh wire drawing dies DS-1 to DS-7. The number of wire drawing dies DS is not limited to seven and may be any number, and the number of pairs of drive rollers RL is also not limited to seven and may be any number. The number of pairs of drive rollers RL may be the same as or different from the number of wire drawing dies DS. The first to seventh drive rollers RL-1 to RL-7 move (transport) the steel wire WK in a moving direction (transport direction) DR.

[0036] In FIG. 2, the second to sixth wire drawing dies DS-2 (#2) to DS-6 (#6) and the pairs of second to sixth drive rollers RL-2 to RL-6 are omitted from the illustration.

[0037] In the die wire drawing device 2000 configured as described above, the steel wire WK to be processed is unwound from a winding reel (not shown) around which the steel wire WK is wound, and is then passed through the first wire drawing die DS-1 (#1), passed through the second wire drawing die DS-2 (#2) of the next pass (next stage) via a pair of first drive rollers RL-1, and passed through the third wire drawing die DS-3 (#3) of the next pass (next stage) via a pair of second drive rollers RL-2. Thereafter, the steel wire WK is similarly passed through the wire drawing die DS of the next stage via the previous stage pair of drive rollers RL, and finally, the processed steel wire WK is drawn out via a pair of seventh drive rollers RL-7. Each time the steel wire WK passes through the first to seventh wire drawing dies DS-1 (#1) to DS-7 (#7), the steel wire WK is processed by each of the wire drawing dies DS-1 (#1) to DS-7 (#7) so that its cross section changes from a circular shape to a flattened shape and its size (cross-sectional area) becomes smaller. The processed steel wire WK is then wound onto a take-up reel (not shown).

[0038] In this embodiment, after such processing, the processed steel wire WK is subjected to ultrasonic flaw detection as a test object WK by the ultrasonic flaw detection device 1000 in the embodiment at a predetermined position PS downstream of the seventh drive roller RL-7.

[0039] The ultrasonic transmitter / receiver unit Pb is connected to the control processing unit 1 and transmits ultrasonic waves to a test object (a steel wire in this example) WK under the control of the control processing unit 1, and receives the ultrasonic waves propagating through the test object WK. The ultrasonic transmitter / receiver unit Pb outputs a reception signal of the received ultrasonic waves to the control processing unit 1. The ultrasonic transmitter / receiver unit Pb is configured, for example, to include one ultrasonic probe that transmits and receives ultrasonic waves. Alternatively, for example, the ultrasonic transmitter / receiver unit is configured to include a pair of first and second ultrasonic probes, where the first ultrasonic probe transmits ultrasonic waves and the second ultrasonic probe is placed a predetermined distance from the first ultrasonic probe and receives the ultrasonic waves. The first and second ultrasonic probes are placed, for example, along the movement direction DR of the steel wire WK, spaced apart by the predetermined distance. The second ultrasonic probe may be placed upstream of the first ultrasonic probe in the movement direction DR, or may be placed downstream of the first ultrasonic probe in the movement direction DR.

[0040] Various types of ultrasonic probes are used. For example, the ultrasonic probe may be a piezoelectric probe that transmits and receives ultrasonic waves using a piezoelectric element, or may be an electromagnetic probe (EMAT, Electromagnetic Acoustic Transducer) that transmits and receives ultrasonic waves through electromagnetic action. EMATs are classified into Lorentz type and magnetostrictive type, and EMATs do not require an acoustic coupling agent to transmit and receive ultrasonic waves and enable non-contact measurement.

[0041] The ultrasonic transmitter / receiver Pb transmits ultrasonic burst waves consisting of multiple waves that are consecutive in time over a relatively short, predetermined time period to the steel wire WK as the test object. For example, an ultrasonic burst wave BW consisting of five waves is shown in Figure 3. The number of waves in the burst wave is arbitrary and can be determined appropriately depending on, for example, the test object WK and its specifications.

[0042] The first to seventh drive rollers RL-1 to RL-7 in the die wire drawing apparatus 2000 also serve as a moving unit in the ultrasonic flaw detection apparatus 1000 that moves the ultrasonic transmitter-receiver unit Pb and the test object (steel wire in this example) WK relatively. The first to seventh drive rollers RL-1 to RL-7, which are an example of a moving unit, are connected to a control processing unit 1 and move the ultrasonic transmitter-receiver unit Pb and the steel wire WK relatively under the control of the control processing unit 1. The control processing unit 1 may also serve as a control device (not shown) in the die wire drawing apparatus 2000. In this embodiment, the test object (steel wire in this example) WK moves along a moving direction DR, which is a predetermined direction, and the ultrasonic transmitter-receiver unit Pb is fixedly disposed at the predetermined position PS. Therefore, the first to seventh drive rollers RL-1 to RL-7 move the steel wire WK along the moving direction DR relative to the fixedly disposed ultrasonic transmitter-receiver unit Pb.

[0043] The input unit 2 is connected to the control processing unit 1 and is a device that inputs various commands, such as a command to start flaw detection, and various data required to operate the ultrasonic flaw detection device 1000, such as the name of the test object, to the ultrasonic flaw detection device 1000, and is, for example, a keyboard, a mouse, and a plurality of input switches to which predetermined functions are assigned. The display unit 3 is connected to the control processing unit 1 and is a device that displays the commands and data input from the input unit 2 and the results of ultrasonic flaw detection under the control of the control processing unit 1, and is, for example, a display device such as a CRT display, an LCD (liquid crystal display), or an organic EL display.

[0044] The input unit 2 and the display unit 3 may be configured with a touch panel. In the case where the input unit 2 is configured with this touch panel, the input unit 2 is, for example, a resistive or capacitive position input device that detects and inputs an operation position. In this touch panel, a position input device is provided on the display surface of the display unit 3, and one or more input content candidates that can be input are displayed on the display unit 3. When a user touches the display position displaying the input content they want to input, the position is detected by the position input device, and the display content displayed at the detected position is input to the ultrasonic flaw detection device 1000 as the user's operation input content. With such a touch panel, the user can easily intuitively understand the input operation, and therefore, an ultrasonic flaw detection device 1000 that is easy for the user to use is provided.

[0045] The IF unit 4 is connected to the control processing unit 1 and is a circuit that inputs and outputs data to and from, for example, an external device under the control of the control processing unit 1, and is, for example, an interface circuit for RS-232C, which is a serial communication method, an interface circuit using the Bluetooth (registered trademark) standard, an interface circuit using the USB standard, etc. The IF unit 4 may also be, for example, a communication interface circuit that transmits and receives communication signals to and from an external device, such as a data communication card or a communication interface circuit conforming to the IEEE802.11 standard, etc.

[0046] The storage unit 5 is connected to the control processing unit 1 and is a circuit that stores various predetermined programs and various predetermined data under the control of the control processing unit 1.

[0047] The various predetermined programs include, for example, a control processing program, and the control processing program includes, for example, a control program, an ultrasonic transmission and reception processing program, a phase processing program, and a flaw detection processing program. The control program is a program that controls each of the units Pb, RL, 2 to 5 of the ultrasonic flaw detection device 1000 according to the function of each unit. The ultrasonic transmission and reception processing program is a program that moves the ultrasonic transmission and reception unit Pb and the test object WK relatively, and transmits and receives ultrasonic waves by the ultrasonic transmission and reception unit Pb at multiple detection positions at multiple different movement amounts on the test object WK relative to the ultrasonic transmission and reception unit Pb. The phase processing program is a program that shifts and aligns multiple ultrasonic waves received by the ultrasonic transmission and reception processing program to have the same phase. The flaw detection processing program is a program that performs ultrasonic flaw detection based on multiple ultrasonic waves whose phases have been aligned by the phase processing program.

[0048] The various types of specified data include data necessary for executing each of these programs, such as the name of the subject, the multiple movement amounts, each received ultrasonic signal at each of the multiple detection sites at each of the multiple movement amounts, and each received signal being processed.

[0049] The storage unit 5 includes, for example, a ROM (Read Only Memory), which is a nonvolatile storage element, and an EEPROM (Electrically Erasable Programmable Read Only Memory), which is a rewritable nonvolatile storage element. The storage unit 5 also includes a RAM (Random Access Memory), which serves as a working memory for the control processing unit 1 and stores data generated during execution of the predetermined program. The storage unit 5 may also be configured with a hard disk drive or solid state drive (SSD) with a relatively large storage capacity.

[0050] The control processing unit 1 is a circuit for controlling each of the units Pb, RL, 2 to 5 of the ultrasonic flaw detection device 1000 in accordance with the function of each unit, and for performing ultrasonic flaw detection. The control processing unit 1 is configured to include, for example, a CPU (Central Processing Unit) and its peripheral circuits. When the control processing program is executed in the control processing unit 1, a control unit 11, an ultrasonic transmission / reception processing unit 12, a phase processing unit 13, and a flaw detection processing unit 14 are functionally configured.

[0051] The control unit 11 controls each of the units Pb, RL, 2 to 5 of the ultrasonic flaw detector 1000 in accordance with the function of each unit, and is in charge of overall control of the ultrasonic flaw detector 1000.

[0052] The ultrasonic transmission / reception processing unit 12 moves the ultrasonic transmission / reception unit Pb and the test object WK relative to each other, and transmits and receives ultrasonic waves using the ultrasonic transmission / reception unit Pb at multiple detection sites at multiple different movement amounts on the test object WK relative to the ultrasonic transmission / reception unit Pb. In this embodiment, the ultrasonic transmission / reception unit Pb is fixedly disposed at a predetermined position PS downstream of the seventh drive roller RL-7, and the steel wire WK of the test object is moved by the first through seventh drive rollers RL-1 through RL-7. Therefore, the ultrasonic transmission / reception processing unit 12 controls the first through seventh drive rollers RL-1 through RL-7 to move the steel wire WK along the movement direction DR, and determines the time when the steel wire WK has moved a predetermined movement amount from the time of the previous transmission / reception as the time of the current transmission / reception. At this time, the location of the test object WK below the ultrasonic transmission / reception unit Pb is set as the current detection site, and causes the ultrasonic transmission / reception unit Pb to transmit and receive ultrasonic waves. As a result, ultrasonic waves are transmitted and received at multiple detection sites at each of the multiple movement amounts, and respective reception signals of the ultrasonic waves at each of the multiple detection sites are obtained.

[0053] After the inspected object WK has moved a predetermined distance, the movement of the inspected object WK may be stopped temporarily and ultrasonic waves may be transmitted and received from the inspected object WK while the inspected object WK is stationary. Alternatively, ultrasonic waves may be transmitted and received from the inspected object WK while the inspected object WK is moving. That is, the ultrasonic transmission and reception processing unit 12 transmits and receives ultrasonic waves using the ultrasonic transmission and reception unit Pb at the multiple detection locations while moving the inspected object WK relative to the ultrasonic transmission and reception unit Pb. In this embodiment, the inspected object WK is the steel wire WK of the die wire drawing device 2000, and the relative movement speed is about three orders of magnitude slower than the sound speed of the ultrasonic waves in terms of speed per second. Therefore, the transmission and reception of ultrasonic waves while the steel wire WK is moving can be considered to be substantially the same as transmitting and receiving ultrasonic waves to and from the steel wire WK while the steel wire WK is stationary.

[0054] For example, when ultrasonic flaw detection is performed for one inspection point SP using ultrasonic reception signals at three first to third detection points DP1 to DP3, as shown in FIG. 4A, first, as the first detection point DP1, the ultrasonic transmission / reception processing unit 12 causes the ultrasonic transmission / reception unit Pb to transmit and receive ultrasonic waves at a first time point t1, thereby obtaining an ultrasonic reception signal RW1, for example, as shown in FIG. 5A. The ultrasonic reception signal RW1 at a movement amount d1 (d1=0, distance d between the inspection point SP and the first detection point DP1) is stored in the storage unit 5 in association with the movement amount d1. Here, the k-th movement amount is dk, the k-th detection point is DPk, and the k-th time point is tk; in this example, k=1, 2, 3. The inspection point SP is a point on the inspected object WK where ultrasonic flaw detection is desired, and the detection point DP is a point on the inspected object WK where ultrasonic waves are transmitted and received. In the example shown in FIG. 4, a defect exists at the position of the inspection point SP, and the inspection point SP is located a distance d from the first detection point DP1. Of course, there may be cases where no defect is present at the inspection point SP. Next, assuming that the moving speed of the steel wire WK is mv and the moving distance between each detection point is DW, as shown in Fig. 4B, at a second time point t2 that is DW / mv after the previous first time point t1, the ultrasonic transmission and reception processing unit 12 causes the ultrasonic transmission and reception unit Pb to transmit and receive ultrasonic waves at the second time point t2, obtains a received ultrasonic signal RW2, for example, as shown in Fig. 5B, and stores the received ultrasonic signal RW2 at the moving distance d2 (d2 = DW, distance d + DW between the inspection point SP and the second detection point DP2) in the memory unit 5 in association with the moving distance d2. Then, as shown in Fig. 4C, at the third time point t3, which is DW / mv after the previous second time point t2, the ultrasonic transmission and reception processing unit 12 causes the ultrasonic transmission and reception unit Pb to transmit and receive ultrasonic waves at the third time point t3, to obtain an ultrasonic reception signal RW3, for example, as shown in Fig. 5C, and stores the ultrasonic reception signal RW3 at a movement amount d3 (d3 = 2 × DW = DW + DW, the distance d + DW + DW between the examination point SP and the third detection part DP3) in association with the movement amount d3 in the storage unit 5. In this way, ultrasonic reception signals RW1 to RW3 at the first to third detection parts DP1 to DP3, respectively, are obtained for one examination point SP.

[0055] The phase processing unit 13 shifts the multiple ultrasonic waves received by the ultrasonic transmission / reception processing unit 12 to align them to the same phase. Each received ultrasonic signal received by the ultrasonic transmission / reception unit Pb at each detection site is received after propagating a distance corresponding to the amount of movement corresponding to the detection site. Therefore, to align them to the same phase, each received ultrasonic signal must be shifted on the time axis by the propagation time required to propagate the distance corresponding to the amount of movement. Therefore, when one of the multiple detection sites is used as a reference detection site, the phase processing unit 13 calculates an adjusted movement amount relative to the reference detection site for each of the multiple movement amounts based on the relative movement speed between the ultrasonic transmission / reception unit and the subject and the relative movement time from the time of transmission and reception of the ultrasonic wave at the reference detection site. The phase processing unit 13 calculates an adjusted movement time by doubling the calculated adjusted movement amount and dividing the doubled adjusted movement amount by the speed of sound of the ultrasonic waves. The phase processing unit 13 then shifts each of the multiple ultrasonic waves received by the ultrasonic transmission / reception processing unit 12 by the calculated adjusted movement times to align them to the same phase.

[0056] The adjustment movement amount of the ultrasonic reception signal RWk is Cdk, and for example, if the first detection location DW1 is the reference detection location, as shown in Figures 4 and 5, the adjustment movement amount Cd1 of the ultrasonic reception signal RW1 received at the first time point t1 is 0, the adjustment movement amount Cd2 of the ultrasonic reception signal RW2 received at the second time point t2 is DW (= mv × (t2 - t1) = mv × (DW / mv)) because the relative movement speed is mv and the relative movement time is t2 - t1 = DW / mv, and the adjustment movement amount Cd3 of the ultrasonic reception signal RW3 received at the third time point t3 is 2 × DW (= mv × (t3 - t1) = mv × (2 × DW / mv)) because the relative movement time is t3 - t1 = 2 × DW / mv. The adjusted travel time of the ultrasonic reception signal RWk is Δtk, the speed of sound of the ultrasonic is sv, the adjusted travel time Δt1 of the ultrasonic reception signal RW1 received at the first time point t1 is 2×0 / sv (Δt1=0), the adjusted travel time Δt2 of the ultrasonic reception signal RW2 received at the second time point t2 is 2×DW / sv (Δt2=2×DW / sv), and the adjusted travel time Δt3 of the ultrasonic reception signal RW3 received at the third time point t3 is 2×2×DW / sv (Δt3=4×DW / sv). For this reason, the phase processing unit 13 shifts the reception signal RW1 of the ultrasonic wave received at the first time point t1 by Δt1=0 on the time axis, shifts the reception signal RW2 of the ultrasonic wave received at the second time point t2 by Δt2=2×DW / sv on the time axis, and shifts the reception signal RW3 of the ultrasonic wave received at the third time point t3 by Δt3=4×DW / sv, thereby aligning the ultrasonic reception signals RW1 to RW3 as shown in Fig. 5B. That is, in this case, the reception signal RW1 of the ultrasonic wave received at the first time point t1 is used as a reference for aligning the phases, the reception signal RW2 of the ultrasonic wave received at the second time point t2 is shifted back by Δt2=2×DW / sv, and the reception signal RW3 of the ultrasonic wave received at the third time point t3 is shifted back by Δt3=4×DW / sv.

[0057] Alternatively, for example, if the second detection site DP2 is the reference detection site, the adjustment movement amount Cd1 of the reception signal RW1 of the ultrasonic wave received at the first time point t1 is -DW (= mv × (t1-t2) = mv × (-DW / mv)), the adjustment movement amount Cd2 of the reception signal RW2 of the ultrasonic wave received at the second time point t2 is 0, and the adjustment movement amount Cd3 of the reception signal RW3 of the ultrasonic wave received at the third time point t3 is DW (= mv × (t3-t2) = mv × (DW / mv)). The adjusted travel time Δt1 of the ultrasonic reception signal RW1 received at the first point in time t1 is 2×(-DW) / sv (Δt1=-2×DW / sv), the adjusted travel time Δt2 of the ultrasonic reception signal RW2 received at the second point in time t2 is 2×0 / sv (Δt2=0), and the adjusted travel time Δt3 of the ultrasonic reception signal RW3 received at the third point in time t3 is 2×DW / sv (Δt3=2×DW / sv). For this reason, the phase processing unit 13 shifts the reception signal RW1 of the ultrasonic wave received at the first time point t1 by Δt1=-2×DW / sv on the time axis, shifts the reception signal RW2 of the ultrasonic wave received at the second time point t2 by Δt2=0 on the time axis, and shifts the reception signal RW3 of the ultrasonic wave received at the third time point t3 by Δt3=2×DW / sv, thereby aligning the ultrasonic reception signals RW1 to RW3. That is, in this case, the reception signal RW2 of the ultrasonic wave received at the second time point t2 is used as a reference for aligning the phases, and the reception signal RW1 of the ultrasonic wave received at the first time point t1 is shifted forward by Δt1=2×DW / sv, and the reception signal RW3 of the ultrasonic wave received at the third time point t3 is shifted backward by Δt3=2×DW / sv.

[0058] In the above description, the movement amount DW between each detection site is the same value, but it may be different between each detection site. Furthermore, for example, the inspection sites may be set appropriately, and multiple detection sites may be set for each of the set inspection sites. Alternatively, for example, inspection sites may be set for each movement amount DW, and one or more detection sites may be set for each of the set inspection sites. In this case, the ultrasonic reception signal for aligning the phase at one inspection site may be the ultrasonic reception signal at one or more detection sites for that inspection site, as well as the ultrasonic reception signal at one or more detection sites for other inspection sites. For example, when transmitting and receiving ultrasonic waves at one detection site for one inspection site, and there are ten inspection sites (1st through 10th) for each movement amount DW, at the first inspection site, in addition to the ultrasonic reception signal at the detection site at the first inspection site, five ultrasonic reception signals at each of the second through sixth inspection sites may be used. This also makes it possible to use ultrasonic wave reception signals at six movement amounts (0, DW, 2×DW, 3×DW, 4×DW, 5×DW) for the first inspection point.

[0059] The flaw detection processing unit 14 performs ultrasonic flaw detection based on multiple ultrasonic waves whose phases have been aligned by the phase processing unit 13. More specifically, for example, the flaw detection processing unit 14 integrates (combines) multiple ultrasonic waves whose phases have been aligned by the phase processing unit 13 into one wave, and displays the integrated result on the display unit 3 as the ultrasonic flaw detection so that a user (operator) can detect defects. Alternatively, for example, the flaw detection processing unit 14 integrates (combines) multiple ultrasonic waves whose phases have been aligned by the phase processing unit 13 into one wave, and detects defects by comparing the integrated result with a predetermined threshold (defect determination threshold) set in advance as the ultrasonic flaw detection. In this case, for example, if the integrated result is equal to or greater than the defect determination threshold, it is determined that there is a defect, and if the integrated result is less than the defect determination threshold, it is determined that there is no defect.

[0060] More specifically, there are two methods for integrating the signals: a first method and a second method. In the first method, the flaw detection processing unit 14 calculates an average result by adding and averaging multiple ultrasonic waves whose phases have been aligned by the phase processing unit 13, and performs ultrasonic flaw detection based on the calculated average result. The flaw detection processing unit 14 generates the average result by simply averaging multiple ultrasonic waves whose phases have been aligned by the phase processing unit 13, each of which has the same timing on the time axis. An example of this is shown in FIG. 6. Then, as described above, the flaw detection processing unit 14 displays the average result on the display unit 3 as the ultrasonic flaw detection so that the user can detect defects. Alternatively, the flaw detection processing unit 14 compares the average result with the defect judgment threshold to detect defects as the ultrasonic flaw detection, and displays the detection result on the display unit 3.

[0061] In the second embodiment, the flaw detection processing unit 14 obtains a multiplication average result by multiplying and averaging multiple ultrasonic waves whose phases have been aligned by the phase processing unit 13, and performs ultrasonic flaw detection based on the obtained multiplication average result. The flaw detection processing unit 14 generates the multiplication average result by multiplying each value of multiple ultrasonic waves whose phases have been aligned by the phase processing unit 13 at the same timing on the time axis and simply averaging the result. An example of this is shown in FIG. 7. Then, as described above, the flaw detection processing unit 14 displays the multiplication average result on the display unit 3 as the ultrasonic flaw detection so that the user can detect defects. Alternatively, the flaw detection processing unit 14 compares the multiplication average result with the defect judgment threshold to detect defects as the ultrasonic flaw detection, and displays the detection result on the display unit 3.

[0062] Fig. 8 is a diagram showing a first comparative example, as an example. The horizontal axis of Fig. 8 represents time, and the vertical axis represents the magnitude of the received signal (signal value). Fig. 9 is a diagram showing a second comparative example, as an example. The horizontal axis of Fig. 9 represents time, and the vertical axis represents the magnitude of the arithmetic average (arithmetic average value).

[0063] 6 to 9. The specimen WK is a carbon steel bar with a diameter of 7 mm, and has a slit-shaped defect with a cross section of 0.15 mm x 0.2 mm (depth) and a longitudinal length of 3 mm. The cross section of the defect corresponds to the area of ​​a circle with a diameter of 0.2 mm. The transmitted ultrasonic waves are 15 burst waves with a frequency of 1.5 MHz.

[0064] In the first comparative example, ultrasonic waves are received by the ultrasonic transmitter / receiver unit Pb when there is no relative movement, and FIG. 8 shows the received ultrasonic signals. In this first comparative example, as shown in FIG. 8, as described above, the defect is very small in size, and the reflected wave from the defect is weak and has a small amplitude. As a result, the signal pW3 due to the defect is comparable to noise, making it difficult to detect. The ultrasonic transmitter / receiver unit Pb is configured with a pair of first and second ultrasonic probes, and the signal DRW3 in FIG. 8 is a received signal obtained by transmitting ultrasonic waves from the first ultrasonic probe, propagating through the carbon steel bar WK, and directly receiving them at the second ultrasonic probe. The same applies to the signals DRW1, DRW2, and DRW4 shown in FIGS. 6, 7, and 9.

[0065] In the second comparative example, 16 ultrasonic wave signals received by the ultrasonic transmitter / receiver unit Pb through 16 ultrasonic wave transmissions and receptions without relative movement are summed and averaged. Figure 9 shows the averaging results for this comparative example. In this second comparative example, as shown in Figure 9, noise is reduced by averaging, improving the signal-to-noise ratio of the defect signal pW4. However, when high-frequency ultrasonic waves are used as burst waves, ultrasonic signals mW corresponding to multiple modes are generated due to the superposition of ultrasonic waves, and these signals are not negligible compared to the defect signal pW4. Adding these signals as they are makes it difficult to identify the ultrasonic signal pW4 in the desired mode, and there is a risk that the signals mW for each mode will be mistakenly recognized as the defect signal pW4. Furthermore, in order to transmit and receive 16 ultrasonic waves, the carbon steel bar WK under test and the ultrasonic transmitter / receiver unit Pb must be stationary relative to each other. This makes the method of the second comparative example difficult to apply to in-line inspection during production on a production line.

[0066] In contrast, in the first and second aspects of the ultrasonic flaw detection device 1000 of this embodiment, the phases of the ultrasonic waveforms in the mode to be detected are aligned and then additive averaging or multiplicative averaging is performed, thereby making the ultrasonic signal in the mode to be detected relatively prominent and making the ultrasonic signals in other modes relatively difficult to see. As a result, as shown in Figures 6 and 7, signals pW1 and pW2 due to the defects can be easily detected.

[0067] The control processing unit 1, input unit 2, display unit 3, IF unit 4 and storage unit 5 in such an ultrasonic flaw detector 1000 can be configured by, for example, a desktop or notebook computer.

[0068] Next, the operation of this embodiment will be described with reference to a flowchart shown in Fig. 10.

[0069] When the ultrasonic flaw detection device 1000 having such a configuration is powered on, it initializes the necessary parts and starts operation. The control processing unit 1 is functionally configured with a control unit 11, an ultrasonic transmission / reception processing unit 12, a phase processing unit 13, and a flaw detection processing unit 14 by executing a control processing program.

[0070] 10, first, the ultrasonic flaw detection device 1000 moves the test piece WK (S1). In this embodiment, the ultrasonic transmission / reception processing unit 12 of the control processing unit 1 moves the steel wire WK, which is an example of the test piece, by the first to seventh drive rollers RL-1 to RL-7 in the die wire drawing device 2000, which is an example of a moving unit.

[0071] Next, the ultrasonic flaw detection device 1000 causes the ultrasonic transmission / reception processing unit 12 to transmit and receive ultrasonic waves to and from the steel wire WK at each detection site for one inspection point, and obtains each received ultrasonic signal at each detection site and stores it in the memory unit 5 (S2).

[0072] Next, the ultrasonic flaw detector 1000 shifts the received ultrasonic signals at each detection location by the phase processing unit 13 of the control processing unit 1 to align them to the same phase, and stores them in the storage unit 5 (S3).

[0073] Next, the ultrasonic flaw detection device 1000 performs flaw detection processing by the flaw detection processing unit 14 of the control processing unit 1 (S4). In the first mode, the flaw detection processing unit 14 obtains an arithmetic average result of each received signal of the in-phase ultrasonic waves and displays this on the display unit 3, for example. Alternatively, the flaw detection processing unit 14 compares this arithmetic average result with the defect determination threshold to detect a defect and displays this detection result on the display unit 3. In the second mode, the flaw detection processing unit 14 obtains a multiplication average result of each received signal of the in-phase ultrasonic waves and displays this on the display unit 3, for example. Alternatively, the flaw detection processing unit 14 compares this multiplication average result with the defect determination threshold to detect a defect and displays this detection result on the display unit 3.

[0074] The flaw detection processing unit 14 may output the flaw detection results (arithmetic average results, multiplication average results, detection results) to an external device via the IF unit 4 as necessary.

[0075] Next, the ultrasonic flaw detection device 1000 determines whether or not the flaw detection has ended (S5) by using the control processing unit 1. If the result of this determination is that the flaw detection has ended, for example, due to an end instruction input by the user (Yes), the ultrasonic flaw detection device 1000 stops the steel wire WK as an example of the test object and ends this process. On the other hand, if the result of the determination is that the flaw detection has not ended (No), the ultrasonic flaw detection device 1000 returns the process to process S2 to detect the next detection point.

[0076] As described above, the ultrasonic flaw detection device 1000 and the ultrasonic flaw detection method implemented therein in the embodiment transmit and receive ultrasonic waves at multiple detection locations by moving the ultrasonic transmitter / receiver unit Pb and the test object WK relatively, and since the position of the ultrasonic transmitter / receiver unit Pb is changed by the relative movement, no additional labor or time is required for changing the position, and defects in the test object WK can be detected more easily by changing the inspection location. The ultrasonic flaw detection device 1000 and the ultrasonic flaw detection method perform ultrasonic flaw detection using multiple received signals of ultrasonic waves at multiple detection locations, and therefore reflection peaks due to defects can be detected even if the frequency of the transmitted ultrasonic waves is increased, thereby improving the spatial resolution of ultrasonic flaw detection and enabling the detection of relatively small defects.

[0077] The ultrasonic flaw detection device 1000 and ultrasonic flaw detection method calculate the additive average result or the multiplicative average result, thereby making the ultrasonic signal in the mode to be detected relatively more prominent and the ultrasonic signal in other modes relatively less visible, thereby making it easier to detect defects.

[0078] The ultrasonic flaw detection device 1000 and ultrasonic flaw detection method can perform flaw detection on a material (semi-finished product) being manufactured or a product manufactured from the material in a manufacturing line where products are manufactured while moving the material.

[0079] The ultrasonic flaw detection device 1000 and ultrasonic flaw detection method calculate the adjustment movement amount based on a reference detection location to determine the adjustment movement time. Therefore, by monitoring the time points of transmission and reception at each detection location, multiple ultrasonic waves can be shifted and aligned to the same phase, eliminating the need for a measuring device (measurement sensor) to measure the detection location.

[0080] According to this embodiment, an ultrasonic flaw detection device 1000 and a method thereof using one ultrasonic probe that transmits and receives ultrasonic waves can be provided. According to this embodiment, an ultrasonic flaw detection device 1000 and a method thereof using a pair of first and second ultrasonic probes can be provided.

[0081] In the above-described embodiment, the steel wire WK, which is an example of an object to be inspected, moves and the ultrasonic transmitter / receiver unit Pb is fixedly disposed. However, the object to be inspected WK may be stationary during inspection, and the ultrasonic transmitter / receiver unit Pb may move in a predetermined direction relative to the object to be inspected. For example, the ultrasonic transmitter / receiver unit Pb may be disposed on a carriage that moves along a guide rail disposed along the object to be inspected WK, and may move along the object to transmit and receive ultrasonic waves to and from the object to be inspected WK as the carriage moves. This provides an ultrasonic flaw inspection apparatus 1000 and a method thereof in which the ultrasonic transmitter / receiver unit Pb moves relative to an object to be inspected (an object that does not move).

[0082] In the above-described embodiment, the speed of sound is assumed to be known. However, in the above-described embodiment, the ultrasonic flaw detection apparatus 1000 may further include a sound speed processing unit that calculates the propagation time of the ultrasonic waves from the transmission time of the first ultrasonic probe to the reception time of the second ultrasonic probe by transmitting ultrasonic waves and receiving the ultrasonic waves by the second ultrasonic probe, and calculates the sound speed of the ultrasonic waves in the test object based on the calculated propagation time of the ultrasonic waves and the predetermined distance. For example, the ultrasonic flaw detection apparatus 1000 may functionally include such a sound speed processing unit 15 in the control processing unit 1, as shown by the dashed line in FIG. 1. In this case, as shown by the dashed line in Figure 10, before processing S1, the ultrasonic flaw detection device 1000 uses the sound speed processing unit 15 to transmit ultrasonic waves from the first ultrasonic probe and receive the ultrasonic waves transmitted by the first ultrasonic probe with the second ultrasonic probe, thereby determining the sound speed of the steel wire WK as an example of the test object (S11).

[0083] Such an ultrasonic flaw detection device 1000 and ultrasonic flaw detection method further includes a sound speed processing unit 15, so that the sound speed of the test object WK can be actually measured, the sound speed can be optimized according to the test object, and the sound speed can be customized according to the test object.

[0084] In order to express the present invention, the present invention has been properly and sufficiently described above through the embodiments with reference to the drawings, but it should be recognized that those skilled in the art can easily change and / or improve the above-mentioned embodiments. Therefore, unless the changes or improvements made by those skilled in the art are at a level that causes departure from the scope of the claims described in the claims, such changes or improvements are interpreted as being included in the scope of the claims. [Explanation of symbols]

[0085] 1000 Ultrasonic flaw detection equipment Pb ultrasonic transmitter / receiver RL (RL-1 to RL-7) Drive roller (an example of a moving part) 1 Control processing section 2 Input section 3 Display section 4 Interface section (IF section) 5 Storage section 11 Control section 12 Ultrasonic transmission / reception processing unit 13 Phase processing section 14. Flaw detection processing section 15 Sonic Processing Section

Claims

1. an ultrasonic transmission / reception processing step of transmitting ultrasonic waves to a subject, moving an ultrasonic transmission / reception unit that receives the ultrasonic waves propagating through the subject relative to the subject, and transmitting and receiving the ultrasonic waves by the ultrasonic transmission / reception unit at a plurality of detection sites at each of a plurality of different movement amounts on the subject relative to the ultrasonic transmission / reception unit; a phase processing step of shifting and aligning the plurality of ultrasonic waves received in the ultrasonic transmission / reception processing step to the same phase; and a flaw detection processing step of performing ultrasonic flaw detection based on the plurality of ultrasonic waves whose phases are aligned in the phase processing step. Ultrasonic flaw detection method.

2. the ultrasound transmission / reception unit transmits ultrasound burst waves consisting of a plurality of waves that are continuous in time to the subject; The flaw detection processing step includes calculating an average result by adding and averaging the plurality of ultrasonic waves whose phases have been aligned in the phase processing step, and performing ultrasonic flaw detection based on the calculated average result. The ultrasonic flaw detection method according to claim 1 .

3. the ultrasound transmission / reception unit transmits ultrasound burst waves consisting of a plurality of waves that are continuous in time to the subject; The flaw detection processing step multiplies and averages the multiple ultrasonic waves whose phases have been aligned in the phase processing step to obtain a multiplication average result, and performs ultrasonic flaw detection based on the obtained multiplication average result. The ultrasonic flaw detection method according to claim 1 .

4. The ultrasonic transmission / reception unit includes one ultrasonic probe for transmitting and receiving ultrasonic waves. The ultrasonic flaw detection method according to claim 1 .

5. the ultrasonic transmitting and receiving unit includes a pair of first and second ultrasonic probes; the first ultrasonic probe transmits ultrasonic waves; the second ultrasonic probe is disposed at a predetermined distance from the first ultrasonic probe and receives ultrasonic waves; The ultrasonic flaw detection method according to claim 1 .

6. The method further comprises a sound speed processing step of receiving the ultrasonic waves transmitted by the first ultrasonic probe with the second ultrasonic probe, thereby determining a propagation time of the ultrasonic waves from a transmission time point when the ultrasonic waves are transmitted by the first ultrasonic probe to a reception time point when the ultrasonic waves are received by the second ultrasonic probe, and determining a sound speed of the ultrasonic waves in the subject based on the determined propagation time of the ultrasonic waves and the predetermined distance. The ultrasonic flaw detection method according to claim 5.

7. The subject moves along a predetermined direction, The ultrasonic flaw detection method according to claim 1 .

8. The subject is immobile during flaw detection, the ultrasonic transmission / reception unit moves along a predetermined direction relative to the subject; The ultrasonic flaw detection method according to claim 1 .

9. The phase processing step includes: When any one of the plurality of detection sites is used as a reference detection site, an adjusted movement amount with respect to the reference detection site is calculated for each of the plurality of movement amounts based on the relative movement speed between the ultrasound transmitting and receiving unit and the subject and the relative movement time from the time of transmission and reception of ultrasound at the reference detection site, and an adjusted movement time is calculated by doubling the calculated adjusted movement amount and dividing the doubled adjusted movement amount by the sound speed of the ultrasound; the plurality of ultrasonic waves received in the ultrasonic transmission / reception processing step are shifted by the plurality of adjusted movement times obtained, respectively, to have the same phase; The ultrasonic flaw detection method according to claim 1 .

10. an ultrasonic transmitting / receiving unit that transmits ultrasonic waves to a subject and receives ultrasonic waves propagating through the subject; a moving unit that moves the ultrasound transmitting / receiving unit and the subject relatively; an ultrasonic transmission / reception processing unit that causes the moving unit to move the ultrasonic transmission / reception unit and the subject relatively, and causes the ultrasonic transmission / reception unit to transmit and receive the ultrasonic waves at a plurality of detection sites at a plurality of different movement amounts in the subject relative to the ultrasonic transmission / reception unit; a phase processing unit that shifts and aligns the phases of the ultrasonic waves received by the ultrasonic transmitting and receiving unit at the plurality of detection sites; a flaw detection processing unit that performs ultrasonic flaw detection based on a plurality of ultrasonic waves whose phases are aligned by the phase processing unit, Ultrasonic flaw detection equipment.

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