JP6177290B2 - Ultrasonic flaw detection apparatus and ultrasonic flaw detection method - Google Patents

Description

  The present invention relates to an ultrasonic flaw detector, a probe, and an ultrasonic flaw detection method used for material inspection.

Strict product inspection is required for various special steel products such as square steel, round steel and flat steel. Ultrasonic flaw detection is widely used to grasp the presence / absence, position, and shape of internal defects in these special steel products.
In ultrasonic flaw detection, it is a challenge to achieve both flaw detection speed and defect detection performance.
In particular, in vertical flaw detection in which ultrasonic waves are incident perpendicular to the material, it is necessary to wait for attenuation of surface echoes due to multiple reflections between the probe and the material surface. For this reason, in the vertical flaw detection, the repeated transmission cycle becomes longer. That is, in vertical flaw detection, the flaw detection speed must be reduced.

  Patent Document 1 discloses a technique for preventing a ghost echo by providing an attachment having a curvature in the circumferential direction in an ultrasonic probe for flaw-detecting a round bar or a tube material vertically.

Japanese Patent No. 2605396

  In patent document 1, since an attachment is required, there exists a subject that the number of parts increases and manufacturing cost becomes high. Moreover, the ultrasonic wave which a probe transmits / receives is attenuate | damped by an attachment, and there exists a subject that defect detection performance reduces.

  An object of the present invention is to reduce the multiple reflection of surface echoes with a simple configuration, thereby shortening the repeated transmission cycle and improving the flaw detection speed without deteriorating the defect detection performance.

An ultrasonic flaw detection apparatus according to the present invention is an ultrasonic flaw detection apparatus for inspecting a specimen,
It has a facing surface portion that faces the test body, and includes a probe that transmits ultrasonic waves in an oblique direction from the facing surface portion,
The probe is
The reflected wave reflected by the test body from the ultrasonic wave transmitted from the opposed surface part is received by the opposed surface part, and the received reflected wave is reflected in a direction different from the direction of the ultrasonic wave transmitted from the opposed surface part.

The test body has a flat portion,
The facing surface portion is
While facing the flat surface portion of the test body, and transmitting ultrasonic waves perpendicular to the flat surface portion,
The ultrasonic flaw detector is
A probe holding portion is provided that holds the probe in a state where the facing surface portion is inclined with respect to the planar portion.

The facing surface portion is
The ultrasonic wave transmitted perpendicularly to the plane part receives the plane part reflected wave reflected by the plane part, and the direction of the ultrasonic wave transmitted the received plane part reflected wave perpendicularly to the plane part Reflect in a different direction.

The facing surface portion is
It has an arrayed ultrasonic transmission / reception element in which a plurality of ultrasonic transmission / reception elements are arranged along an inclined direction,
The arrayed ultrasonic transmitting / receiving element transmits ultrasonic waves perpendicular to the plane portion.

The ultrasonic flaw detector is
An ultrasonic flaw detector having a transmission / reception circuit for transmitting an ultrasonic wave by giving a delay time to each ultrasonic transmission / reception element of the plurality of ultrasonic transmission / reception elements is provided.

The transceiver circuit is
Receiving a reception signal representing a reflected wave received by each of the plurality of ultrasonic transmission / reception elements, adding the delay time to the received reception signal, and combining the reception signal with the delay time added thereto; Run.

The ultrasonic flaw detector is
A transport roller for transporting the specimen in the transport direction;
The facing surface portion is
It is inclined with respect to the plane portion in a sectional view in the transport direction.

The ultrasonic flaw detector has a water tank in which water is stored,
The test body and the facing surface portion are immersed in water stored in the water tank.

The probe according to the present invention is a probe of an ultrasonic flaw detector for inspecting a specimen having a flat surface portion.
A facing surface portion facing the flat surface portion of the test body and transmitting ultrasonic waves perpendicular to the flat surface portion, the facing surface portion being held in an inclined state with respect to the flat surface portion.

The test object flaw detection method according to the present invention is a test object flaw detection method for inspecting a test object,
By a probe having a facing surface portion facing the test body, an ultrasonic wave is transmitted in an oblique direction from the facing surface portion,
The reflected wave reflected by the test body from the ultrasonic wave transmitted from the opposed surface part is received by the opposed surface part, and the received reflected wave is reflected in a direction different from the direction of the ultrasonic wave transmitted from the opposed surface part.

The test object flaw detection method is:
The probe is held in a state where the facing surface portion is inclined with respect to the flat surface portion of the test body, and ultrasonic waves are transmitted perpendicularly from the facing surface portion to the flat surface portion.

  According to the ultrasonic flaw detector according to the present invention, an ultrasonic wave is transmitted in an oblique direction from the facing surface portion by the probe having the facing surface portion facing the test body, and the ultrasonic wave transmitted from the facing surface portion is the test body. Since the reflected wave is received and the received reflected wave is reflected in a direction different from the direction of the ultrasonic wave transmitted from the opposite surface portion, the flaw detection speed can be improved with a simple configuration without deteriorating the defect detection performance. There is an effect.

1 is a schematic diagram showing an ultrasonic flaw detector 100 according to Embodiment 1. FIG. 1 is a block configuration diagram of an ultrasonic flaw detector 110 according to Embodiment 1. FIG. It is a figure which shows a comparative example, (a) is a schematic diagram which shows generation | occurrence | production of the surface echo in a comparative example, (b) is a graph which shows the mode of attenuation | damping of the surface echo in a comparative example. It is a figure which shows a comparative example, (a) is a schematic diagram which shows the mode of the ultrasonic flaw in a comparative example, (b) is a graph which shows the repetition transmission period in a comparative example. 1A and 1B are diagrams illustrating an ultrasonic flaw detector 100 according to Embodiment 1, in which FIG. 1A is a schematic diagram illustrating generation of surface echoes in the ultrasonic flaw detector 100, and FIG. 2B is attenuation of surface echoes in the ultrasonic flaw detector 100; The graph which shows the state of. 1A and 1B are diagrams illustrating an ultrasonic flaw detection apparatus 100 according to Embodiment 1, in which FIG. 1A is a schematic diagram illustrating a state of ultrasonic flaw detection in the ultrasonic flaw detection apparatus 100, and FIG. Graph showing. 4 is a graph showing an example of a relationship between an angle of a probe 120 with respect to a flat portion 210 and a residual echo reduction effect in the ultrasonic flaw detector 100 according to the first embodiment. FIG. 5 is a schematic diagram showing another example of attenuation of surface echoes of the ultrasonic flaw detector 100 according to the first embodiment. The schematic diagram which shows the case where the ultrasonic flaw detection method which concerns on Embodiment 1 is applied to an oblique flaw detection.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below. Moreover, in the following drawings, the relationship of the size of each component may be different from the actual one. In the description of the embodiment, when directions or positions such as top, bottom, left, right, front, back, front, back are indicated, these notations are described as such for convenience of explanation. However, it does not limit the arrangement or orientation of devices, instruments, parts, and the like.

Embodiment 1 FIG.
*** Explanation of configuration ***
FIG. 1 is a schematic view showing an ultrasonic flaw detector 100 according to the present embodiment.
FIG. 2 is a diagram showing a block configuration of the ultrasonic flaw detector 110 according to the present embodiment.
The configuration of the ultrasonic flaw detector 100 will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the ultrasonic flaw detector 100 inspects a test body 200 having a flat portion 210.
The ultrasonic flaw detector 100 includes an ultrasonic flaw detector 110, a probe 120, a probe holder 130, a water tank 140, a transport roller 150, and a transmission path 160.

<Test body 200 and transport roller 150>
The ultrasonic flaw detection apparatus 100 inspects the test body 200 that is transported in the transport direction by the transport roller 150.
In the present embodiment, it is assumed that the test body 200 is transported by the transport roller 150 in the direction from the back to the front in FIG. Hereinafter, the direction in which the test body 200 is transported is referred to as a transport direction P1 (see FIG. 4A).
FIG. 1 is a schematic cross-sectional view of the ultrasonic flaw detector 100 in the transport direction P1.

  Specifically, the test body 200 is square steel or flat steel. The test body 200 may not be square steel or flat steel as long as it is a material having the flat portion 210, and may be round steel or pipe material. Moreover, the test body 200 should just be a test object of ultrasonic flaw detection, and does not need to be a steel material.

  The transport roller 150 transports the test body 200 in the transport direction P <b> 1 in a state where the flat surface portion 210 of the test body 200 faces the probe 120.

<Probe 120>
The probe 120 has a facing surface portion 121 facing the test body 200, and transmits ultrasonic waves in an oblique direction from the facing surface portion 121.
The probe 120 receives the reflected wave reflected by the test body 200 from the ultrasonic wave transmitted from the opposing surface part 121 by the opposing surface part 121, and the direction of the ultrasonic wave transmitted from the opposing surface part 121 is the received reflected wave. Reflect in different directions.

In the present embodiment, the probe 120 has a facing surface portion 121 that faces the flat surface portion 210 of the test body 200 and transmits an ultrasonic wave perpendicular to the flat surface portion 210.
The facing surface portion 121 transmits an ultrasonic wave perpendicular to the flat surface portion 210 and receives a reflected wave from the test body 200. The facing surface portion 121 receives a reflected wave reflected by the flat portion 210 that is the surface of the test body 200, a reflected wave reflected by a scratch or the like inside the test body 200, or a reflected wave reflected by the bottom surface of the test body 200. The reflected wave reflected by the flat portion 210 is also called a surface echo.

As shown in FIG. 1, the facing surface portion 121 is inclined with respect to the flat surface portion 210 in a cross-sectional view in the transport direction P1.
The opposing surface part 121 has the arrayed ultrasonic transmission / reception element 122 in which a plurality of ultrasonic transmission / reception elements 1221a to 1221n are arranged along the inclined direction.
The facing surface portion 121 is in a state inclined by θ ° with respect to the flat surface portion 210. That is, the arrayed ultrasonic transmission / reception element 122 has a plurality of ultrasonic transmission / reception elements 1221a to 1221n arranged in a state inclined by θ ° with respect to the flat portion 210.
The probe 120 is also referred to as an array probe or a phased array probe having arrayed ultrasonic transmitting / receiving elements 122 arranged on the facing surface 121.

<Probe holder 130>
The probe holding unit 130 holds the probe 120 in a state in which the facing surface part 121 is inclined with respect to the flat part 210.
As shown in FIG. 1, the probe holding unit 130 fixes the probe 120 in a state where the facing surface portion 121 is inclined by θ ° with respect to the flat surface portion 210. The probe holding unit 130 may have any configuration as long as the probe 120 can be fixed in a state where the facing surface portion 121 is inclined with respect to the flat surface portion 210.
As a specific example of the probe holding unit 130, the probe holding unit 130 has a hole for exposing the opposed surface portion 121 of the probe 120, and the inclined opposed surface portion 121 exposed from the hole is inclined. It is good also as a structure which fixes the probe 120 to the edge of a hole with a fixing member. The fixing member may be a screw or may be fixed by a fitting structure. Further, the probe 120 may have a flange portion 123 that is caught at the edge of the hole, and the opposing surface portion 121 may be inclined with a spacer interposed between the edge of the hole and the flange portion.

<Ultrasonic flaw detector 110>
The ultrasonic flaw detector 110 is connected to the probe 120 via the transmission path 160.
The ultrasonic flaw detector 110 controls the transmission of ultrasonic waves from the probe 120 via the transmission path 160. Further, the ultrasonic flaw detector 110 receives a reception signal representing a reflected wave received by the probe 120 via the transmission path 160.

  The ultrasonic flaw detector 110 includes a transmission / reception circuit 1101 that transmits ultrasonic waves by giving delay times Ta to Tn to the ultrasonic transmission / reception elements of the plurality of ultrasonic transmission / reception elements 1221a to 1221n. The transmission / reception circuit 1101 is provided for each of the plurality of ultrasonic transmission / reception elements 1221a to 1221n. That is, the ultrasonic flaw detector 110 includes transmission / reception circuits 1101a to 1101n corresponding to the plurality of ultrasonic transmission / reception elements 1221a to 1221n.

  Each of the transmission / reception circuits 1101a to 1101n receives a reception signal representing a reflected wave received by each of the plurality of ultrasonic transmission / reception elements 1221a to 1221n, adds a delay time T to the received reception signal, and adds the delay time T. A combining process for combining the received signals is executed.

The ultrasonic flaw detector 110 includes the above-described transmission / reception circuits 1101a to 1101n, an addition unit 117, and a CPU 118.
The transmission / reception circuits 1101a to 1101n are connected to the ultrasonic transmission / reception elements 1221a to 1221n, respectively.
In the following description, the term “transmission / reception circuit 1101” refers to each or all of the transmission / reception circuits 1101a to 1101n. In addition, the term “ultrasound transmitting / receiving element 1221” refers to each or all of the ultrasound transmitting / receiving elements 1221 a to 1221 n.

  The ultrasonic flaw detector 110 includes transmission units 111a to 111n that transmit delay times Ta to Tn for each of the ultrasonic transmission / reception elements of the plurality of ultrasonic transmission / reception elements 1221a to 1221n.

  As illustrated in FIG. 2, the transmission / reception circuit 1101a includes a transmission unit 111a, a transmission delay unit 112a, a reception unit 113a, a reception amplifier 114a, an A / D conversion unit 115a, and a reception delay unit 116a. The same applies to each of the transmission / reception circuits 1101b to 1101n, and the transmission / reception circuits 1101b to 1101n are distinguished by adding a suffix to the reference numeral.

Each of transmission delay units 112a to 112n outputs each of delay times Ta to Tn to each of transmission units 111a to 111n.
Each of the transmission units 111a to 111n acquires a delay time from each of the transmission delay units 112a to 112n. Each of the transmission units 111a to 111n transmits an ultrasonic wave from each of the ultrasonic transmission / reception elements 1221a to 1221n with a delay by the acquired delay time.
As described above, the ultrasonic wave is transmitted by giving a delay time to each of the plurality of ultrasonic transmission / reception elements 1221a to 1221n, so that the planar portion of the test body 200 can be obtained from the arrayed ultrasonic transmission / reception element 122 arranged on the facing surface portion 121. Ultrasonic waves can be incident perpendicular to 210. That is, the probe 120 can transmit ultrasonic waves in an oblique direction from the facing surface portion 121.

Each of the reception units 113a to 113n acquires a reception signal representing an ultrasonic wave received by each of the ultrasonic transmission / reception elements 1221a to 1221n.
Each of the reception amplifiers 114a to 114n amplifies the reception signal output from each of the reception units 113a to 113n.
Each of A / D converters 115a to 115n converts the reception signal amplified by each of reception amplifiers 114a to 114n into a digital signal.
Each of the reception delay units 116a to 116n adds a delay time to the reception signal converted into a digital signal by each of the A / D conversion units 115a to 115n and outputs the received signal.
The adder 117 combines the received signals output from the transmission / reception circuits 1101a to 1101n and added with delay times by the reception delay units 116a to 116n using the CPU 118. Execute.

  As described above, the ultrasonic flaw detector 110 controls transmission of ultrasonic waves from the probe 120 and receives a reception signal representing a reflected wave received by the probe 120.

<Water tank 140>
The ultrasonic flaw detector 100 has a water tank 140 in which water 141 is stored.
The test body 200 and the facing surface portion 121 are immersed in water 141 stored in the water tank 140.
That is, the ultrasonic flaw detection apparatus 100 performs ultrasonic flaw detection using a water immersion method.

*** Explanation of ultrasonic flaw detection method ***
Hereinafter, the ultrasonic flaw detection method according to the present embodiment will be described by comparing the ultrasonic flaw detection according to the present embodiment with a comparative example.
In the ultrasonic flaw detection method according to the present embodiment, ultrasonic waves are transmitted in an oblique direction from the facing surface portion 121 by the probe 120 having the facing surface portion 121 facing the test body 200. And the reflected wave which the ultrasonic wave transmitted from the opposing surface part 121 reflected by the test body 200 is received by the opposing surface part 121, and the received reflected wave is reflected in the direction different from the direction of the ultrasonic wave transmitted from the opposing surface part 121. . For example, the received reflected wave may be reflected in a direction other than the specimen 200.
Further, in the ultrasonic flaw detection method according to the present embodiment, the probe 120 is held in a state where the facing surface portion 121 is inclined with respect to the flat surface portion 210 of the test body 200, and the flat surface portion 210 is supported from the facing surface portion 121. The ultrasonic waves are transmitted almost vertically.

FIGS. 3A and 3B are diagrams showing a comparative example, in which FIG. 3A is a schematic diagram showing the generation of surface echoes in the comparative example, and FIG. 3B is a graph showing the state of attenuation of surface echoes in the comparative example.
FIG. 4 is a diagram illustrating a comparative example, (a) is a schematic diagram illustrating a state of ultrasonic flaw detection in the comparative example, and (b) is a graph illustrating a repetitive transmission cycle in the comparative example.
5A and 5B are diagrams showing the ultrasonic flaw detector 100 according to the present embodiment. FIG. 5A is a schematic diagram showing generation of surface echoes in the ultrasonic flaw detector 100, and FIG. It is the figure which graphed the mode of attenuation of surface echo.
6A and 6B are diagrams illustrating the ultrasonic flaw detection apparatus 100 according to the present embodiment, in which FIG. 6A is a schematic diagram illustrating a state of ultrasonic flaw detection in the ultrasonic flaw detection apparatus 100, and FIG. 6B is an ultrasonic flaw detection. 4 is a graph showing a repetitive transmission cycle in apparatus 100.

As shown in FIG. 3A, the probe 520 of the comparative example is arranged such that the facing surface portion 521 is parallel to the flat surface portion 210 of the test body 200 in the cross-sectional view in the transport direction P1. Therefore, the ultrasonic wave u1 transmitted from the probe 520 so as to be perpendicularly incident on the flat surface portion 210 is reflected substantially vertically by the flat surface portion 210 which is the surface of the test body 200, and the first surface is a reflected wave thereof. The echo e1 is incident on the opposing surface portion 521 substantially perpendicularly. Accordingly, the reflected wave reflected by the first surface echo e1 on the facing surface portion 521 is incident again on the flat surface portion 210 substantially perpendicularly, and the reflected wave is incident on the facing surface portion 521 substantially perpendicularly as the second surface echo e2. Similarly, the third surface echo e3 is incident on the facing surface portion 521 substantially perpendicularly.
As described above, in the comparative example, the surface echoes are repeatedly reflected substantially perpendicular to each other between the facing surface portion 521 and the flat surface portion 210.

  As shown in FIG. 3B, the surface echo gradually attenuates. However, in the comparative example, the surface echo is reflected substantially perpendicularly between the facing surface portion 521 and the flat surface portion 210. Therefore, the reflection is repeated many times, and the amplitude of the scratch detection threshold for detecting the scratch inside the specimen 200 is detected. It takes time until it decays below or the surface echo disappears.

4A, it is assumed that the probe 520 of the comparative example is held so that the facing surface portion 521 is parallel to the flat surface portion 210 in a cross-sectional view in the transport direction P1. The test body 200 is transported in the transport direction P1.
The ultrasonic wave u1 is transmitted from the probe 520, and the first surface echo e1 reflected by the flat surface portion 210 of the test body 200 repeats vertical reflection between the facing surface portion 521 and the flat surface portion 210.
FIG. 4B shows a state in which the first surface echo e1 repeats reflection and N reflections are necessary until the amplitude becomes equal to or less than a scratch detection threshold of an amplitude capable of transmitting the next ultrasonic wave. Yes.
As described above, in the comparative example, since the repeated transmission cycle becomes long, the flaw detection speed has to be slowed down.

As shown in FIG. 5A, the probe 120 according to the present embodiment is such that the facing surface portion 121 is inclined by θ ° with respect to the flat surface portion 210 of the test body 200 in a cross-sectional view in the transport direction P1. Is arranged. Therefore, the opposing surface portion 121 receives the planar portion reflected wave E1 reflected by the planar portion 210 by the ultrasonic wave U1 transmitted perpendicularly to the planar portion 210, and receives the received planar portion reflected wave E1 with respect to the planar portion 210. And reflected in a direction different from the direction of the ultrasonic wave U1 transmitted vertically.
The plane portion reflected wave E1 is a first surface echo.

Below, an example of the state of reflection of the surface echo between the opposing surface part 121 and the plane part 210 which concerns on this Embodiment is demonstrated.
(1) As shown in FIG. 5A, the ultrasonic wave U <b> 1 is transmitted from the probe 120 so as to enter the plane part 210 perpendicularly. That is, the probe 120 transmits the ultrasonic wave U1 in an oblique direction from the facing surface portion 121 and vertically enters the flat surface portion 210. At this time, the incident angle of the ultrasonic wave U1 to the flat portion 210 is 0 °.
(2) The ultrasonic wave U <b> 1 is reflected by the flat portion 210 that is the surface of the test body 200, and the flat portion reflected wave E <b> 1 (first surface echo) that is a reflected wave is incident on the facing surface portion 121. Since the opposing surface portion 121 is inclined by θ ° with respect to the planar portion 210, the planar portion reflected wave E1 is incident on the opposing surface portion 121 at an incident angle of approximately θ °.
(3) The reflected wave reflected by the opposed surface portion 121 from the plane portion reflected wave E1 is defined as a reflected wave R1. The reflected wave R1 is transmitted from the facing surface portion 121 to the flat surface portion 210 at a reflection angle of approximately θ °. Since the facing surface portion 121 is inclined by θ ° with respect to the flat surface portion 210, the reflected wave R1 reaches the flat surface portion 210 at an incident angle larger than the incident angle of (1). The incident angle at this time is approximately 2θ °, for example.
(4) The second surface echo E <b> 2 reflected by the reflected wave R <b> 1 on the flat surface part 210 is inclined by θ ° with respect to the flat surface part 210, so that the incident angle of (2) with respect to the counter surface part 121. Incident with a larger incident angle. For example, the incident angle is approximately 3θ °.
(5) The reflected wave reflected by the second surface echo E2 at the facing surface portion 121 is defined as a reflected wave R2. The reflected wave R2 is transmitted from the facing surface portion 121 to the flat surface portion 210 at a reflection angle of approximately 3θ °. Since the facing surface portion 121 is inclined by θ ° with respect to the flat surface portion 210, the reflected wave R2 is incident on the flat surface portion 210 at an incident angle larger than the incident angle of (3). As shown in (a) of FIG. 5, the reflected wave reflected by the flat portion 210 from the reflected wave R <b> 2 does not reach the facing surface portion 121. Therefore, the surface echo disappears here.

As described above, in the ultrasonic flaw detector 100 according to the present embodiment, the surface echo between the facing surface portion 121 and the flat surface portion 210 repeats reflection while gradually increasing the incident angle. Disappears.
In addition, the specific example of the incident angle and reflection angle of the surface echo described above is an example, and depending on the state or material of the facing surface portion 121 and the flat surface portion 210, the above values may not be obtained. However, the surface echo between the facing surface portion 121 and the flat surface portion 210 repeats reflection between the facing surface portion 121 and the flat surface portion 210 while gradually increasing the incident angle.

As shown in FIG. 5B, the plane portion reflected wave E1 and the second surface echo E2, which are surface echoes, are gradually attenuated. The flat part reflected wave E1 and the second surface echo E2 are reflected obliquely while gradually increasing the incident angle between the facing surface part 121 and the flat part 210, and thus disappear after repeated reflection several times. . Therefore, the surface echo can be eliminated in a short time.
FIG. 5B shows a state in which the surface echo has disappeared after the ultrasonic wave U1 is reflected twice by the flat surface portion 210. FIG.

In FIG. 6A, the probe 120 is held so that the facing surface portion 121 is inclined by θ ° with respect to the flat surface portion 210 of the test body 200 in a cross-sectional view in the transport direction P1. The test body 200 is transported in the transport direction P1.
The ultrasonic wave U1 is transmitted from the probe 120, and the plane portion reflected wave E1 reflected by the plane portion 210 of the test body 200 is repeatedly reflected between the facing surface portion 521 and the plane portion 210. At this time, the incident angle of the reflected wave gradually increases in each of the facing surface portion 521 and the flat surface portion 210.
FIG. 6B shows how the surface echo of the ultrasonic wave U1 transmitted from the probe 120 disappears twice. When the surface echo disappears, the ultrasonic flaw detector 100 transmits the next ultrasonic wave U1.
Thus, according to the ultrasonic flaw detection apparatus 100 according to the present embodiment, the repeated transmission cycle can be shortened, so that the flaw detection speed can be increased.

FIG. 7 is a graph showing an example of the relationship between the angle of the facing surface portion 121 of the probe 120 with respect to the flat surface portion 210 of the test body 200 and the residual echo reduction effect in the ultrasonic flaw detector 100 according to the present embodiment. is there.
In the example of FIG. 7, when the opposing surface portion 121 of the probe 120 is not tilted, that is, when the residual echo at 0 ° is 1, the residual echo when the opposing surface portion 121 is tilted by 1 ° is approximately 0.4. It shows that it is reduced.
In the example of FIG. 7, the residual echo is reduced from 1 to about 0.4 while the angle is between 0 ° and 1 °. Also, the residual echo is reduced from about 0.4 to about 0.25 while the angle is between 1 ° and 3 °. When the angle is 3 ° or more, the residual echo remains at about 0.25.
The angle of the facing surface 121 of the probe 120 with respect to the flat portion 210 is preferably 1 ° to 7 °, more preferably 2 ° to 6 °, and particularly preferably 3 ° to 4 °.
In addition, the angle of the opposing surface part 121 with respect to the plane part 210 is not restricted to said value. The optimum angle may be selected in consideration of the size and material of each component of the ultrasonic flaw detector 100, the installation environment of the ultrasonic flaw detector 100, and the like.

*** Explanation of the effect of the embodiment ***
As described above, the ultrasonic flaw detector 100 according to the present embodiment can be configured such that the reflected wave is incident on the probe obliquely with a simple configuration without using additional components. Therefore, the transmission cycle can be shortened without incurring manufacturing costs.

  Further, according to the ultrasonic flaw detection apparatus 100 according to the present embodiment, the probe directly transmits and receives ultrasonic waves, so that the flaw detection time can be shortened while maintaining the defect detection performance. In addition, when a phased array probe is used, a vertical beam can be output by giving a delay time to each element of the ultrasonic transmission / reception elements even if they are arranged obliquely, so that multiple reflections of surface echoes in vertical flaw detection are reduced. It can be reduced in time.

  Moreover, according to the ultrasonic flaw detector 100 according to the present embodiment, it is possible to configure the reflected wave to enter the probe obliquely with a simple configuration. Therefore, the flaw detection speed can be improved without deteriorating the defect detection performance by reducing the multiple reflection of the surface echo and repeatedly shortening the transmission cycle.

  Moreover, according to the ultrasonic flaw detector 100 according to the present embodiment, a large residual echo reduction effect can be obtained when the angle of the specimen with respect to the flat surface is 1 ° to 7 °. As described above, since a large effect can be obtained by slightly tilting the probe, it is easy to apply the present embodiment to existing equipment, and the present embodiment can be applied to existing equipment. Even if the form is applied, it is possible to obtain a great effect of repeatedly shortening the transmission cycle and improving the flaw detection speed without deteriorating the defect detection performance.

  Further, according to the probe according to the present embodiment, it is possible to suppress re-reflection of the reflected wave that returns.

*** Other configurations ***
FIG. 8 is a schematic diagram showing another example of the attenuation of the surface echo of the ultrasonic flaw detector 100 according to the present embodiment.
As shown in FIG. 8, the opposing surface portion 121 receives the plane portion reflected wave E1 reflected by the plane portion 210 by the ultrasonic wave U1 transmitted perpendicularly to the plane portion 210, and tests the received plane portion reflected wave E1. The light may be reflected in a direction other than the body 200. By adopting such a configuration, there is no residual echo, and the flaw detection speed can be greatly improved without deteriorating the defect detection performance.

  The test body 200 may not be square steel or flat steel as long as it is a material having the flat portion 210. The test body 200 may be round steel or pipe. In the case of round steel or pipe, this embodiment can be applied by regarding a part of the surface extending in the transport direction P1 as the flat portion 210. . In other words, in the cross-sectional view in the transport direction P1, this embodiment can be applied by regarding the surface in contact with the outer circumference of the round steel or tube material as the flat portion 210. In addition, the test body 200 should just be a test object of ultrasonic flaw detection, and does not need to be a steel material.

FIG. 9 is a schematic diagram showing a case where the ultrasonic flaw detection method according to the present embodiment is applied to oblique flaw detection. FIG. 9 illustrates a probe that performs oblique flaw detection by transmitting ultrasonic waves U2 to a test body 200d such as a round steel.
As shown in FIG. 9, even when ultrasonic waves are transmitted obliquely to the test body 200d, an ultrasonic wave U2d transmitted substantially perpendicularly to the surface S1 in contact with the outer periphery of the test body 200d is generated. There is.

The dotted line probe 520d is a probe for comparison with the present embodiment, and transmits ultrasonic waves U2 vertically from the facing surface portion 521d to perform oblique flaw detection on the specimen 200d. In this case, a surface echo due to the ultrasonic wave U2d may occur.
On the other hand, the solid-line probe 120d is a probe according to the present embodiment, and transmits an ultrasonic wave U2 in an oblique direction from the facing surface portion 521d, and performs oblique flaw detection on the specimen 200d.
By configuring like the probe 120d according to the present embodiment, the surface echo by the ultrasonic wave U2d transmitted substantially perpendicularly to the surface S1 in contact with the outer periphery of the test body 200d is converted into the test body like the reflected wave R1d. It can be reflected in directions other than 200d. Therefore, surface echoes can be reduced more significantly than when the probe 520d of the comparative example is used.

  In the present embodiment, a phased array probe is used as a probe. However, an adaptive array or multidimensional array probe may be used.

  As mentioned above, although embodiment of this invention was described, you may implement combining 2 or more among this embodiment. Alternatively, one of the embodiments may be partially implemented. Alternatively, two or more of the embodiments may be partially combined. In addition, this embodiment may be implemented in any combination as a whole or in part.

  As described in the present embodiment, in an apparatus that transmits an ultrasonic beam, reflection using a transmission / reception method in which the vertical direction of the facing surface that transmits the beam and the output direction of the beam are different returns to the facing surface. The method of suppressing wave re-reflection can be applied to other than ultrasonic flaw detection. For example, the above method may be applied to ultrasonic diagnosis, ultrasonic measurement, flaw detection using waves other than ultrasonic waves, diagnosis, measurement, and detection.

  In addition, said embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, and a use, A various change is possible as needed. .

  100 ultrasonic flaw detector, 110 ultrasonic flaw detector, 111, 111a, 111b, 111n transmitter, 112, 112a, 112b, 112n transmission delay unit, 113, 113a, 113b, 113n receiver, 114, 114a, 114b, 114n Receive amplifier, 115, 115a, 115b, 115n A / D converter, 116, 116a, 116b, 116n Receive delay unit, 117 Adder, 118 CPU, 1101, 1101a, 1101b, 1101n Transceiver circuit, 120, 120d, 520, 520d probe, 121, 121d, 521, 521d facing surface part, 122 array-type ultrasonic transmission / reception element, 1221, 1221a, 1221b, 1221n ultrasonic transmission / reception element, 123 collar part, 130 probe holding part, 140 water tank, 141, 150 transport roller, 160 transmission path, 200, 200d specimen, 210 plane portion, P1 transport direction, u1, U1, U2, U2d ultrasound, e1 first surface echo, e2 second surface echo, e3 third surface echo , E1 plane reflected wave, E2 second surface echo, R1, R2, R1d reflected wave, S1 surface, T, Ta, Tn delay time.

Claims (4)

In an ultrasonic flaw detector that inspects a specimen by vertical flaw detection ,
The test body has a flat portion,
A facing surface that faces the flat portion, the a from the opposite surface portion oblique direction, and a probe having opposite surface portions for transmitting ultrasonic waves in a direction perpendicular to the flat portion,
A probe holding portion for holding the probe in a state where the facing surface portion is inclined with respect to the plane portion ,
The facing surface portion is
The ultrasonic wave transmitted from the opposing surface portions to receive the flat portion reflected wave reflected by the flat portion, the flat portion reflected waves received, in a different orientation and outgoing ultrasound orientation with respect to the planar portion is reflected,
The facing surface portion is
An array-shaped ultrasonic transmission / reception element in which a plurality of ultrasonic transmission / reception elements are arranged along an inclined direction, the array-type ultrasonic transmission / reception element transmitting ultrasonic waves to the plane portion,
The ultrasonic flaw detector is
An ultrasonic flaw detector comprising an ultrasonic flaw detector having a transmission / reception circuit that transmits a ultrasonic wave by giving a delay time to each ultrasonic transmission / reception element of the plurality of ultrasonic transmission / reception elements . The transceiver circuit is
Receiving a reception signal representing a reflected wave received by each of the plurality of ultrasonic transmission / reception elements, adding the delay time to the received reception signal, and combining the reception signal with the delay time added thereto; The ultrasonic flaw detector according to claim 1 to be executed.   An ultrasonic flaw detection apparatus for inspecting a specimen by means of vertical flaw detection, comprising: a probe having an opposing surface portion opposed to a flat surface portion of the specimen; and an ultrasonic wave having a transmission / reception circuit for transmitting ultrasonic waves from the opposing surface portion In an ultrasonic flaw detection method of an ultrasonic flaw detector equipped with a flaw detector,
  A probe holding unit holds the probe in a state in which the facing surface portion is inclined with respect to the planar portion;
  The opposing surface portion has an arrayed ultrasonic transmission / reception element in which a plurality of ultrasonic transmission / reception elements are arranged along the direction of inclination,
  The transmission / reception circuit gives a delay time to each of the ultrasonic transmission / reception elements of the plurality of ultrasonic transmission / reception elements to transmit an ultrasonic wave, and is in an oblique direction from the opposing surface portion, and with respect to the planar portion Send ultrasonic waves vertically,
  The opposing surface portion receives a plane portion reflected wave reflected by the plane portion with an ultrasonic wave transmitted to the plane portion, and the received plane portion reflected wave is transmitted to the plane portion. An ultrasonic flaw detection method that reflects light in a direction different from the direction.   The transmission / reception circuit receives a reception signal representing a reflected wave received by each of the plurality of ultrasonic transmission / reception elements, adds the delay time to the received reception signal, and receives the reception signal with the delay time added. The ultrasonic flaw detection method according to claim 3 to be synthesized.

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