JP2022049238A - Ultrasonic inspection method and ultrasonic inspection device - Google Patents

Abstract

To suitably detect the presence of internal defects, etc., for even an inspection object that has irregularities such as flaws or patterns on the surface.SOLUTION: The present invention executes: an inspection jig mounting step in which an inspection jig G composed of a hardened substance and having a facing surface G2 where a second irregular part G1 of a shape corresponding to a first irregular part EF2 of an inspection object H is formed, is placed in a fitted state where the second irregular part G1 is fitted to the first irregular part EF2; and an echo sounder scanning step in which an ultrasonic wave is transmitted to a jig surface G3 which is the reverse side of the facing surface G2 of the inspection jig G after the inspection jig mounting step, and an echo sounder transducer 12 that receives the reflected wave of the transmitted wave is scanned.SELECTED DRAWING: Figure 1

Description

The present invention relates to an ultrasonic inspection method and an ultrasonic inspection apparatus for inspecting an object to be inspected having a first uneven portion having at least one of a dent or a protrusion on the surface by ultrasonic waves.

Conventionally, as in the technique disclosed in Patent Document 1, ultrasonic inspection using ultrasonic waves to inspect the inside of an object to be inspected in order to detect defects formed in welded parts inside the object to be inspected. Methods and ultrasonic inspection devices are known.
In the technique disclosed in Patent Document 1, an ultrasonic inspection apparatus having a transmitter / receiver for transmitting an ultrasonic transmitted wave and receiving a reflected wave of the transmitted transmitted wave is in a state along the surface of an object to be inspected. Scan with to inspect the inside of the object to be inspected. The ultrasonic inspection device includes a rotary wheel that is rotationally driven along the surface of the object to be inspected and a rotary encoder that converts the amount of rotation of the rotary wheel into position information, so that the surface of the object to be inspected is scanned in the surface scanning direction. It is possible to detect whether there is a possibility that a defect or the like exists inside the portion.

Japanese Unexamined Patent Publication No. 2002-048770

The technique disclosed in Patent Document 1 can perform good inspection when the surface of the object to be inspected is a flat surface or a relatively gentle curved surface, but when the surface has irregularities such as scratches and patterns, it can be inspected well. When the reflected wave was imaged, defects and the like formed in the welded portion inside were not displayed, and noise due to the unevenness of the surface was displayed, and there was room for improvement.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is that even if an object to be inspected has irregularities such as scratches and patterns on its surface, the presence or absence of internal defects is good. Provided are an ultrasonic inspection method capable of detecting an ultrasonic inspection method and an ultrasonic inspection apparatus.

The ultrasonic inspection method to achieve the above purpose is
It is an ultrasonic inspection method for inspecting an object to be inspected by ultrasonic waves having a first uneven portion having at least one of a dent and a protrusion on the surface, and the characteristic configuration thereof is.
An inspection jig made of a cured product having a facing surface on which a second uneven portion having a shape corresponding to the first uneven portion of the object to be inspected is formed, and the second uneven portion is fitted into the first uneven portion. The inspection jig mounting process to make it fit and fit
After the inspection jig mounting step, the transmitted wave of ultrasonic waves is transmitted to the jig surface which is the back surface of the facing surface of the inspection jig, and the transmitted and received waves receive the reflected wave of the transmitted transmitted wave. The point is to execute a transmitter / receiver scanning process for scanning the device.

According to the above characteristic configuration, by using an inspection jig made of a cured product having a facing surface on which a second uneven portion having a shape corresponding to the first uneven portion of the object to be inspected is formed, an inspection jig mounting step is performed. In the above, the second uneven portion on the facing surface of the inspection jig can be fitted to the first uneven portion formed on the surface of the object to be inspected. Further, by executing the transmitter / receiver scanning step in the fitted state, the transmitter / receiver that transmits / receives ultrasonic waves to / from the jig surface on the back side of the facing surface of the inspection jig may be scanned, and the object to be inspected may be scanned. Since it is not necessary to place the transmitter / receiver along the surface of the first uneven portion formed on the surface of the transmitter / receiver, scanning of the transmitter / receiver can be smoothly performed.
This makes it possible to realize an ultrasonic inspection method capable of satisfactorily detecting the internal state of an object to be inspected having many irregularities on its surface.

Further features of the ultrasonic inspection method are
The inspection jig mounting step includes a high-viscosity substance coating step of applying a high-viscosity substance between the surface of the object to be inspected and the facing surface of the inspection jig.

According to the above characteristic configuration, even if a gap is formed between the first uneven portion of the object to be inspected and the second uneven portion of the inspection jig, the gap is filled with a high-viscosity substance. It is possible to reduce noise by suppressing the reflection of ultrasonic waves in the gap.

Further features of the ultrasonic inspection method are
In the inspection jig mounting step, the inspection is performed in a state where a gap is provided between the first uneven portion and the second uneven portion in the surface direction along the surface of the object to be inspected in the fitted state. The point is that the jig is attached to the object to be inspected.

As a result of diligent studies, the inventors put the inspection jig in a state where a gap is provided between the first uneven portion and the second uneven portion in the surface direction along the surface of the object to be inspected in the fitted state. By attaching to the object to be inspected, the high-viscosity substance between the object to be inspected and the inspection jig spreads over the entire area along the gap in the surface direction between the first concavo-convex portion and the second concavo-convex portion. Since it spreads substantially evenly, it is difficult for the transmitted wave from the transmitter / receiver to be reflected in the vicinity of the first uneven portion, and it has been found that the noise at the portion can be reduced more satisfactorily.
Incidentally, the inventors have confirmed by an experiment described later that the thicker the high-viscosity substance is, the more easily noise is generated in the passing direction of the transmitted wave transmitted from the transmitter / receiver.

Further features of the ultrasonic inspection method are
In the inspection jig mounting step, in the fitted state, the inspection is performed in a state in which a gap is provided between the first unevenness portion and the second unevenness portion in a vertical direction orthogonal to the surface of the object to be inspected. The point is that the jig is attached to the object to be inspected.

As a result of diligent studies, the inventors have found that the inspection jig is provided with a gap between the first uneven portion and the second uneven portion in the vertical direction orthogonal to the surface of the object to be inspected in the fitted state. By attaching it to the object to be inspected, the high-viscosity substance between the object to be inspected and the inspection jig enters the gap in the vertical direction orthogonal to the surface of the first uneven portion and the second uneven portion. Since it spreads substantially evenly over the entire area along the line, it is difficult for the transmitted wave from the transmitter / receiver to be reflected in the vicinity of the first uneven portion, and it has been found that the noise at the portion can be reduced more satisfactorily.

Further features of the ultrasonic inspection method are
After the inspection jig mounting step and before the transmitter / receiver scanning step, the facing surface of the inspection jig is pressed against the surface of the object to be inspected and slides in a direction along the surface. The point is to execute the pressing and sliding process.

According to the above feature configuration, by executing the pressing and sliding step after the inspection jig mounting process, the facing surface of the inspection jig is pressed against the surface of the object to be inspected and slid along the surface. By moving, the thickness of the high-viscosity substance between the facing surface of the inspection jig and the surface of the object to be inspected can be made substantially uniform and sufficiently thin, so that the noise of the detection result is further reduced. can.

Further features of the ultrasonic inspection method are
Prior to the inspection jig mounting step, the thermosetting or thermoplastic resin that has been heated and softened is pressed against the first uneven portion of the surface of the object to be inspected and left for a predetermined time to be cured. The point is to execute the facing surface forming step of molding the inspection jig by forming the uneven portion with respect to the facing surface.

According to the above characteristic configuration, by pressing the softened thermosetting or thermoplastic resin against the surface of the object to be inspected, it is formed on the surface of the object to be inspected with respect to the facing surface of the thermosetting resin. The second uneven portion having a shape corresponding to the first uneven portion can be easily formed without performing cutting or the like.

As an ultrasonic inspection method,
The object to be inspected has a cylindrical shape.
It is also suitably and suitably applicable when the first uneven portion is continuously formed along the circumferential direction around the cylinder axis of the object to be inspected.
Specifically, the object to be inspected is a pair of pipes through which a fluid flows inside, and
Even when the EF pipe joint for welding the pair of pipes is included, the ultrasonic inspection can be preferably performed.
In this case, the inspection jig has a plate shape, and the surface thereof has a shape along the cylindrical surface of the object to be inspected.

The ultrasonic inspection device for achieving the above purpose is
It is an ultrasonic inspection device that inspects an object to be inspected by ultrasonic waves having a first uneven portion having at least one of a dent and a protrusion on the surface, and its characteristic configuration is:
An inspection jig made of a cured product having a facing surface on which a second uneven portion having a shape corresponding to the first uneven portion of the object to be inspected is formed, and an inspection jig.
A transmitter / receiver for transmitting ultrasonic transmitted waves and receiving reflected waves of the transmitted transmitted waves is provided on the jig surface which is the back surface of the facing surface of the inspection jig.

According to the ultrasonic inspection apparatus having the above-mentioned characteristic configuration, the ultrasonic inspection method described so far is suitably executed, and even if the inspection object has many irregularities on the surface, the internal state thereof is good. Can be detected.

It is a perspective view of the ultrasonic inspection apparatus which carries out the ultrasonic inspection method which concerns on embodiment. It is a partial cross-sectional view of the ultrasonic inspection apparatus which carries out the ultrasonic inspection method which concerns on embodiment. It is a figure which shows the pattern of the formation state of the gap between the facing surface of an inspection jig, and the surface of an object to be inspected. This is the inspection result when there is no gap between the facing surface of the inspection jig and the surface of the object to be inspected. It is an inspection result when there is a gap between the side of the convex portion of the inspection jig and the surface of the inspection object. It is an inspection result when there is a gap between the upper side of the recess of the inspection jig and the surface of the inspection object. This is the inspection result when the inspection jig is lightly placed on the object to be inspected when there is a gap between the side of the convex portion of the inspection jig and the surface of the object to be inspected. It is an inspection result when the inspection jig made of an elastomer was used.

In the ultrasonic inspection method and the ultrasonic inspection apparatus according to the embodiment of the present invention, even if the object to be inspected has irregularities such as scratches and patterns on the surface, defects and the like formed in the welded portion inside the object to be inspected, etc. It relates to a thing that can detect the presence or absence of.
Hereinafter, the ultrasonic inspection apparatus 100 according to the present invention will be described with reference to FIGS. 1 and 2.

The ultrasonic inspection device 100 according to the embodiment is an ultrasonic inspection device 100 that inspects an object H to be inspected by ultrasonic waves having a first uneven portion EF2 having at least one of a recess EF2b and a protrusion EF2a on the surface EF3. ..
As shown in FIG. 1 or 2, the ultrasonic inspection device 100 transmits an ultrasonic transmission wave to the object H to be inspected and also receives a reflected wave of the transmitted transmission wave with the transmitter / receiver 12. , The transmitter / receiver 12 and a signal processing unit 20 electrically connected via a cable 5 are provided.
The transmitter / receiver 12 is supported by the transmitter / receiver support body 13 so as to move back and forth in the perspective direction with respect to the object H to be inspected, and is provided at the end of the object H to be inspected at the time of inspection. With the 15 in contact with the surface EF3 of the object H to be inspected, the transmitter / receiver support body 13 can be moved along the surface of the object H to be inspected to inspect the internal state of the object H to be inspected. It is configured in. The inspection result is sent from the transmitter / receiver 12 to the signal processing unit 20 via the cable 5, processed by the signal processing unit 20, and displayed on the monitor 6.

In the embodiment, the object H to be inspected is provided with a first uneven portion EF2 having at least one of a recessed EF2b and a protrusion EF2a on the surface EF3, and is a gas such as a city gas (for example, a city gas 13A). It is composed of a pair of gas pipes L (an example of pipes) through which the gas pipes pass, and an EF pipe joint EF for airtightly welding the connection portion La of the gas pipe L. Further, in the embodiment, in the first uneven portion EF2, a plurality of recesses EF2b and protrusions EF2a extending along the pipe circumferential direction around the pipe axis are alternately formed on the surface EF3 of the EF pipe joint EF.
On the surface of the EF pipe joint EF where the first uneven portion EF2 is provided, one end connection portion EF1a that can be electrically connected is provided at one end of a conductive wire (not shown) arranged inside the EF pipe joint EF. , The other end connection portion EF1b that can be electrically connected is provided at the other end of the conductive wire (not shown), and when a voltage is applied from a power source (not shown), the EF is provided around the connection portion La of the gas pipe L. The connection portion La is airtightly connected by melting and fusing the pipe joint EF. The conductive wire is provided inside the EF pipe joint EF in a form of being wound along its cylindrical shape.
That is, in the embodiment, the object H to be inspected has a cylindrical shape, and the first uneven portion EF2 is continuously formed along the circumferential direction around the cylinder axis of the EF pipe joint EF. There is.

As shown in FIGS. 1 and 2, the transmitter / receiver support main body 13 is configured so that its cross-sectional shape is substantially U-shaped downward, and is on the side of the object H to be inspected at the time of inspection. The rotary wheel 26 is provided at the end portion, and the contact end portion 24 capable of contacting the object to be inspected H is provided separately from the rotary wheel 26. That is, at the time of inspection, the rotating wheel 26 is rotated along the surface EF3 of the object H to be inspected, and the contact end portion 24 is slid along the surface EF3 of the object H to be inspected to transmit and receive. The wave device support main body 13 is configured to be movable along the surface EF3 of the object H to be inspected.
As shown in FIG. 2, the probe 15 of the transmitter / receiver 12 is provided between the rotary wheel 26 and the abutting end portion 24.

Inside the transmitter / receiver support main body 13, a rotary encoder 27 capable of detecting the rotation amount of the rotary wheel 26 (movement amount of the transmitter / receiver support main body 13) is provided.
To add an explanation, the rotation of the rotary wheel 26 is rotary via a belt transmission mechanism 33 including a rotary wheel rotary shaft 28, a first pulley 29, a belt 30, a second pulley 31, and a rotary shaft 32. It is configured to be transmitted to the encoder 27, detect the movement amount of the transmitter / receiver support main body 13 based on the rotation speed, and transmit to the signal processing unit 20 via the cable 5.

To add a description about the transmitter / receiver 12, the probe 15 of the transmitter / receiver 12 has a rotating wheel 26 and an abutting end portion 24 in contact with the object H to be inspected. The transmitter / receiver 12 is supported so as to be able to move back and forth in the perspective direction.
That is, the probe 15 as the transmitter / receiver 12 takes a retired posture of retiring to the inside of the transmitter / receiver support main body 13 in the natural state of the coil spring 36 by the coil spring 36 provided inside the transmitter / receiver support main body 13. The transmitter / receiver 12 including the probe 15 is configured to be able to be gripped by a finger or the like from the outside of the transmitter / receiver support main body 13 and pressed toward the object to be inspected H at the time of inspection. ..
With the above configuration, at the time of inspection, the ultrasonic inspection apparatus 100 grips the wave transmitter / receiver 12 and brings the rotary wheel 26 and the contact end portion 24 into contact with the surface EF3 of the object H to be inspected. The ultrasonic inspection device 100 is installed on the object H to be inspected, and the transmitter / receiver 12 is pushed in a direction close to the object H to be inspected against the urging force of the coil spring 36, so that the tip surface 37 of the probe 15 is 37. Can abut and adhere to the surface EF3 of the object H to be inspected. Further, in this state, the switch 38 can be turned on to transmit ultrasonic waves to the object H to be inspected.
On the other hand, during non-inspection, the probe 15 retreats inside the transmitter / receiver support body 13 to prevent damage due to contact with other members.

When the inside of the object to be inspected H, which is provided with the first uneven portion EF2 on the surface EF3, is inspected by using the ultrasonic inspection apparatus 100 described above, transmission and reception are performed along the surface of the object to be inspected H. When scanning the probe 15 of the wave device 12, there is a high possibility that the probe 15 will be caught by the recessed EF2b or the protrusion EF2a, and smooth scanning will not be possible. Further, at the time of operation, it becomes impossible to maintain a sufficient contact state between the probe 15 of the transmitter / receiver 12 and the surface EF3 of the object H to be inspected. In this case, since the ultrasonic waves pass through the air having different acoustic impedances and the object H to be inspected, noise is generated in the inspection result, and defects inside the object H to be inspected cannot be detected. There is a risk of
Therefore, the ultrasonic inspection apparatus 100 according to the embodiment is an inspection jig made of a cured product having a facing surface G2 on which a second uneven portion G1 having a shape corresponding to the first uneven portion EF2 of the object to be inspected H is formed. The ultrasonic inspection is performed in a fitted state in which the tool G is provided and the second uneven portion G1 of the inspection jig G is fitted to the first uneven portion EF2 of the object H to be inspected.
That is, in the fitted state, the recess EF2b of the object to be inspected H and the protrusion G1b of the inspection jig G face each other, and the protrusion EF2a of the object H to be inspected and the recess G1a of the inspection jig G face each other. In this state, they are in a state of being fitted to each other.
In the embodiment, the surface of the inspection jig G has a plate shape along the outer surface EF3 of the EF pipe joint EF of the object H to be inspected, and is a part around the pipe axis of the outer surface EF3 of the EF pipe joint EF. It is a shape that covers.

In the ultrasonic inspection apparatus 100 of the embodiment, glycerin J (an example of a high-viscosity substance) is applied between the surface EF3 of the object H to be inspected and the facing surface G2 of the inspection jig G at the time of inspection. Will be done.
Here, the glycerin J and the inspection jig G are preferably made of a material having an acoustic impedance substantially equal to the acoustic impedance of the object H to be inspected, and the inspection jig G is, for example, polyethylene, polypropylene, or polyvinyl chloride. A resin material such as vinyl can be preferably used. When the material is used, the inspection jig G is preliminarily processed into a shape corresponding to the shape of the surface EF3 of the object H to be inspected.

When the inspection of the object to be inspected H having the first uneven portion EF2 is performed by using the inspection jig G having the second uneven portion G1 as in the ultrasonic inspection apparatus 100 shown in the embodiment, the first It is necessary to appropriately fill the space between the uneven portion EF2 and the second uneven portion G1 with glycerin J as the high-viscosity substance J without any gap.
Therefore, as shown in FIG. 3B, the second uneven portion G1 of the inspection jig G according to the embodiment is inspected in the surface direction along the surface EF3 of the object H to be inspected in the fitted state. The shape is such that a gap S is provided between the first uneven portion EF2 and the second uneven portion G1 of the object H. The gap S (L1 in FIG. 3B) is preferably more than 0 mm in the sense that glycerin J is interposed, and is preferably about 0.4 mm or less in order to suppress the occurrence of deficiency of glycerin J. In the inspection shown below, it is set to 0.1 mm.
Further, as shown in FIG. 3C, the second uneven portion G1 of the inspection jig G is a vertical direction of the object to be inspected H, which is orthogonal to the surface EF3 of the object to be inspected H in the fitted state. A gap S may be provided between the protrusion EF2a of the first uneven portion EF2 and the recess G1a of the second uneven portion G1. The gap S (L2 in FIG. 3C) is preferably more than 0 mm in the sense that glycerin J is interposed, and is preferably about 0.4 mm or less in order to suppress the occurrence of deficiency of glycerin J. In the inspection shown below, it is set to 0.2 mm.
The second uneven portion G1 of the inspection jig G may have a single shape shown in FIG. 3 (B), a single shape shown in FIG. 3 (C), or a single shape shown in FIG. 3 (B). ) And the shape shown in FIG. 3 (C).

As the inspection jig G, for example, a thermoplastic elastomer (an example of a thermoplastic resin: specifically, an olefin-based elastomer (trade name: Plastic Nendo Oyumaru)) can be used in addition to the above-mentioned materials. When a material is used, the thermoplastic elastomer softened by heating is pressed against the first uneven portion EF2 of the surface EF3 of the object H to be inspected for a predetermined time (for example, 15 seconds or more) before the inspection jig mounting step described later. The inspection jig G is molded by leaving it to stand for about 60 seconds or less), cooling it, and then curing it to form the second uneven portion G1 with respect to the facing surface G2.
Therefore, the inspection jig G using the thermoplastic elastomer has a shape in which a gap is not formed between the first uneven portion EF2 of the object to be inspected H and the second uneven portion G1 of the inspection jig G (FIG. 3 (A). ) Is the shape shown in).

Next, an inspection method using the inspection jig G according to the embodiment will be described.
First, a case will be described in which the inspection jig G uses a resin material such as polyethylene in which the second uneven portion G1 is molded into a shape corresponding to the first uneven portion EF2 of the object H to be inspected. ..
In this case, first, the inspection jig mounting step of putting the inspection jig G into a fitted state in which the second uneven portion G1 is fitted to the first uneven portion EF2 of the object to be inspected H is executed. Here, the inspection jig mounting step includes a glycerin application step of applying glycerin J between the surface EF3 of the object to be inspected H and the facing surface G2 of the inspection jig G.

Further, after the inspection jig mounting step, the facing surface G2 of the inspection jig G is pressed against the surface EF3 of the object H to be inspected in a direction along the surface EF3 (direction in which the first uneven portion EF2 extends). Perform a sliding pressing sliding process. As a result, the glycerin J can be blended between the first uneven portion EF2 and the second uneven portion G1.
Further, as the inspection jig G, as shown in FIG. 3B, in the fitted state, the first uneven portion EF2 and the first uneven portion EF2 of the object to be inspected H are in the surface direction along the surface EF3 of the object to be inspected H. When a shape having a shape for providing a gap S between the two uneven portions G1 is adopted, the inspection treatment is performed in a state where the gaps S are formed at both ends of the protrusions G1b of the second uneven portion G1 of the inspection jig G. The jig G is temporarily fixed to the object H to be inspected by the viscosity of glycerin J.

After the inspection jig mounting step and the pressing sliding step, an ultrasonic transmission wave is transmitted to the jig surface G3 which is the back surface of the facing surface G2 of the inspection jig G, and the transmitted wave is reflected. The transmitter / receiver scanning step of scanning the transmitter / receiver 12 that receives the wave along the search direction K along the tube axis direction of the object H to be inspected is executed.

On the other hand, when a thermoplastic elastomer is used as the inspection jig G, the thermoplastic elastomer softened by heating is placed on the first uneven portion of the surface EF3 of the object H to be inspected before the inspection jig mounting step. The inspection jig G is formed by pressing it against the EF2, leaving it for a predetermined time (for example, about 10 seconds or more and 60 seconds or less), cooling it, and then curing it to form the second uneven portion G1 with respect to the facing surface G2 of the inspection jig G. The facing surface forming step to be molded is executed. Subsequent steps are the same as those described above, except that glycerin J is not used.

Next, the inspection results using the ultrasonic inspection apparatus 100 and the ultrasonic inspection method described so far will be described with reference to FIGS. 3 to 8. In FIGS. 4 to 8, the vertical axis indicates the depth of the EF pipe joint EF from the surface EF3, and the horizontal axis indicates the distance from the operation start position in the investigation direction K. The darker the color, the higher the reflection intensity of ultrasonic waves.
In the inspection, the ultrasonic detection result as an inspection result using the shapes of FIGS. 3 (A), 3 (B), and 3 (C) for the inspection jig G made of a resin material such as polyethylene is shown in FIG. 5 and 6 are shown. In the inspection for obtaining the inspection results shown in FIGS. 4, 5 and 6, the above-mentioned pressing and sliding step is executed.
In the inspection, the conductive wire D embedded in the EF pipe joint EF as the object H to be inspected is the detection target.
As shown in FIG. 3A, when the inspection jig G adopts a shape in which no gap is provided between the first uneven portion EF2 and the second uneven portion G1, strong noise (strong noise (in the inspection result shown in FIG. 4) is observed in the inspection result shown in FIG. It can be seen that the arrow α) appears in FIG.
On the other hand, as shown in FIG. 3B, the inspection jig G has a shape in which a gap S is provided between the first uneven portion EF2 and the second uneven portion G1 in the direction along the surface EF3 of the object H to be inspected. When adopted, it can be seen from the inspection results shown in FIG. 5 that there is no noise and the conductive wire D is detected well.
Further, as shown in FIG. 3C, the shape of the inspection jig G is such that a gap S is provided between the first uneven portion EF2 and the second uneven portion G1 in the direction orthogonal to the surface EF3 of the object H to be inspected. In the case of adopting the above, it can be seen that the inspection result shown in FIG. 6 also shows that the noise is small and the conductive wire D is detected well.
As shown in the inspection results, when the gap S is provided as shown in FIGS. 3B and 3C, the reason why good inspection results are obtained is that when the pressing sliding step is being executed, Glycerin J moves between the first concavo-convex portion EF2 and the second concavo-convex portion G1 through the gap S, so that there is almost no air between the first concavo-convex portion EF2 and the second concavo-convex portion G1. It is probable that it was realized.

On the other hand, using the inspection jig G having the shape shown in FIG. 3B, the inspection jig G is lightly applied to the object to be inspected H coated with glycerin J without performing the above-mentioned pressing and sliding step. In the case of mounting, as shown in the inspection result of FIG. 7, it can be seen that there is a portion where the conductive wire D cannot be properly detected (arrow α2 in FIG. 7), and a good inspection result is not obtained.

Further, when the inspection jig G made of a thermoplastic elastomer is used, as shown in FIG. 8, although some parts with strong signals (arrow α3 in FIG. 8) are generated, almost good inspection results can be obtained. You can see that it is.
When the inspection jig G made of the thermoplastic elastomer is used, the above-mentioned pressing and sliding step is not performed because glycerin J is not used.

[Another Embodiment]
(1) In the above embodiment, the object H to be inspected is an EF pipe joint EF for airtightly welding a pair of gas pipes L through which a gas such as city gas passes and a connection portion La of the gas pipe L. It was made up of.
However, the object H to be inspected is not limited to this, and may have any structure as long as the surface EF3 is provided with the first uneven portion EF2 having at least one of the recessed EF2b and the protrusion EF2a. Can be adopted.
Further, in the above embodiment, the first uneven portion EF2 shows a configuration example in which a plurality of recessed EF2b and protrusions EF2a are alternately formed along the pipe circumferential direction of the EF pipe joint EF, but the present invention is not limited to this. However, for example, a recessed EF2b and a protrusion EF2a may be formed as an embossed shape.

It should be noted that the configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in other embodiments as long as there is no contradiction. The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

The ultrasonic inspection method and the ultrasonic inspection apparatus of the present invention can satisfactorily detect the presence or absence of defects or the like inside even if the object to be inspected has irregularities such as scratches and patterns on the surface. It can be effectively used as an inspection method and an ultrasonic inspection device.

12: Transmitter / receiver 100: Ultrasonic inspection device EF2: First uneven portion EF2a: Protrusion EF2b: Recess G: Inspection jig G1: Second uneven portion G1a: Recess G1b: Protrusion G2: Facing surface G3: Jig surface H : Object to be inspected J: Highly viscous substance S: Gap

Claims (10)

An ultrasonic inspection method for inspecting an object to be inspected having a first uneven portion having at least one of a dent and a protrusion on the surface by ultrasonic waves.
An inspection jig made of a cured product having a facing surface on which a second uneven portion having a shape corresponding to the first uneven portion of the object to be inspected is formed, and the second uneven portion is fitted into the first uneven portion. The inspection jig mounting process to make it fit and fit
After the inspection jig mounting step, an ultrasonic transmission wave is transmitted to the jig surface which is the back surface of the facing surface of the inspection jig, and a transmission / reception wave for receiving the reflected wave of the transmitted transmission wave is received. An ultrasonic inspection method that performs a transmitter / receiver scanning process that scans a device. The ultrasonic inspection according to claim 1, wherein the inspection jig mounting step includes a high-viscosity substance coating step of applying a high-viscosity substance between the surface of the object to be inspected and the facing surface of the inspection jig. Method. In the inspection jig mounting step, the inspection is performed in a state where a gap is provided between the first uneven portion and the second uneven portion in the surface direction along the surface of the object to be inspected in the fitted state. The ultrasonic inspection method according to claim 2, wherein the jig is attached to the object to be inspected. In the inspection jig mounting step, in the fitted state, the inspection is performed in a state in which a gap is provided between the first unevenness portion and the second unevenness portion in a vertical direction orthogonal to the surface of the object to be inspected. The ultrasonic inspection method according to claim 2 or 3, wherein the jig is attached to the object to be inspected. After the inspection jig mounting step and before the transmitter / receiver scanning step, the facing surface of the inspection jig is pressed against the surface of the object to be inspected and slides along the surface. The ultrasonic inspection method according to any one of claims 2 to 4, wherein the pressing and sliding step is performed. Prior to the inspection jig mounting step, the thermosetting or thermoplastic resin that has been heated and softened is pressed against the first uneven portion of the surface of the object to be inspected and left for a predetermined time to be cured. The ultrasonic inspection method according to any one of claims 1 to 5, wherein the facing surface forming step of molding the inspection jig by forming the uneven portion on the facing surface is performed. The object to be inspected has a cylindrical shape.
The ultrasonic inspection method according to any one of claims 1 to 6, wherein the first uneven portion is continuously formed along the circumferential direction around the cylinder axis of the object to be inspected. The object to be inspected includes a pair of pipes that allow fluid to flow inside, and
The ultrasonic inspection apparatus according to claim 7, further comprising an EF pipe joint for welding the pair of pipes. The ultrasonic inspection device according to claim 7 or 8, wherein the inspection jig has a plate shape and the surface thereof has a shape along the cylindrical surface of the object to be inspected. An ultrasonic inspection device for inspecting an object to be inspected by ultrasonic waves having a first uneven portion having at least one of a dent and a protrusion on the surface.
An inspection jig made of a cured product having a facing surface on which a second uneven portion having a shape corresponding to the first uneven portion of the object to be inspected is formed, and an inspection jig.
An ultrasonic inspection device including a transmitter / receiver for transmitting an ultrasonic transmitted wave and receiving a reflected wave of the transmitted transmitted wave to the jig surface which is the back surface of the facing surface of the inspection jig.

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