JP2001296283A - Ultrasonic probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic probe, capable of executing flaw detection with superior inspection accuracy, even if the surface of an inspection object has irregularities thereon. SOLUTION: This probe is equipped with a slide piece 15, divided plurally and arranged along the outside edge of a probe 1 body, a holder 10 for holding the slide piece 14 slidably in the roughly vertical direction to an inspection surface, a spring 20 for energizing the slide piece 14 to the inspection surface, a skirt 16 installed on the outside edge part of the slide piece 14 for forming the inside of the contact part into a roughly closed space in contact with the inspection surface, and a hose 22, a supply hole 10d, counterbores 10a, 15a and a groove 15m for supplying couplant into the closed space including the contact part between the inspection surface and the inspection surface of the probe 1 body. When the flaw detection is executed, by allowing a probing surface 1a of the probe 1 to abut on the inspection surface, the slide piece 14 is slid following the inspection object surface shape, regardless of irregularities, the probe 1 is held at a prescribed angle with the inspection surface, and the couplant is held at least between the probing surface 1a of the probe 1 and the surface to be inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe used for performing an ultrasonic inspection test on a structure such as a nuclear reactor, a boiler or a chemical plant by a direct contact method using an operating device or a jig. About the tentacles.

[0002]

2. Description of the Related Art FIGS. 6A and 6B are views for explaining an ultrasonic probe used for an ultrasonic inspection test. FIG. 6A is a plan view of the ultrasonic probe, and FIG. FIG. 2 is a front view of a cross section of a main part showing a use state. In FIG. 1, the probe 1 is supported movably in the axial direction by, for example, a holder 2 and is elastically urged by a spring 3 along the axis O direction. At the lower end side of the probe 1, a shoe 4 for holding the probe 1 at a predetermined angle with respect to the surface of the inspection object 6, usually at a right angle, is fixed to the probe 1 by bolts 5. Have been. The probe surface 1 a of the probe 1 and the lower surface 4 a of the shoe 4 are formed so as to conform to the surface shape of the inspection object 6. That is,
When the inspected object 6 is, for example, a pipe having an inner diameter R1 and an outer diameter R2, a convex shape (solid line in the drawing) with a radius R1 when flaw detection is performed from the inside of the pipe, and a concave shape with a radius R2 when flaw detection is performed from the outside. (Dotted line in the figure).

When performing a flaw detection using such a probe, a liquid couplant (flaw detection medium) is supplied between the flaw detection surface 1a and the inspection object 6, and the flaw detection surface 1a is cleaned. It is brought into contact with the surface of the inspection object 6. Then, an ultrasonic wave generated by an unillustrated ultrasonic wave source (for example, a piezoelectric body) is transmitted to the flaw detection surface of the inspection object 6 via the probe surface 1a, and the reflection reflected inside the inspection object 6 is performed. Receive the waves. Probe surface 1
a is formed in conformity with the surface shape of the inspection object 6.
Abuts the surface of the flaw detection surface surely. Further, the shoe 4 contacts the flaw detection surface 1a in a state where the axis O of the probe 1 is substantially perpendicular to the flaw detection surface of the inspection object 6, so that the inspection object 6 is kept in contact with the inspection surface 6 as long as this state is maintained. The inside could be inspected with high accuracy.

[0004]

By the way, as shown in FIG. 6, when the probe surface 1a of the probe 1 and the lower surface 4a of the shoe 4 are formed so as to conform to the surface shape of the object 6 to be inspected. There is no problem as long as the surface shape of the inspection object 7 and the surface shapes of the flaw detection surface 1a and the shoe 4 match, but the flaw detection surface of the inspection object 6 and the probe 1 If the shapes of the surface 1a and the lower surface 4a of the shoe 4 are inconsistent, a problem occurs.

[0005] For example, in a welded joint portion, since a surplus is finished with a grinder, irregularities are often generated on the surface. On the other hand, since the probe 1 and the shoe 4 are integral with each other, if the surface of the inspection object 6 has a concave portion, as shown in the flaw detection state of FIG. Since the ultrasonic wave is away from the surface of the object 6, the ultrasonic wave is hardly incident on the inspection object 6, and the inspection becomes impossible or the inspection accuracy is reduced. This problem becomes more pronounced when the couplant flows out from between the flaw detection surface and the probe surface 1a, because ultrasonic waves are not transmitted to the inspection object.

An apparatus for detecting a flaw by using a plurality of shoes and following the shape of the surface to be inspected is disclosed in, for example, Japanese Patent Application Laid-Open No.
Although the invention described in JP-A-9-150334 is known,
The present invention is intended to attach an ultrasonic probe to the shoe itself and perform vertical and oblique flaw detection at one time along the surface shape, corresponding to the local surface shape such as unevenness on the surface to be inspected. It is not configured to do so.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide an ultrasonic probe capable of detecting a defect with excellent inspection accuracy even on an object having an uneven surface. Is to do.

[0008]

In order to achieve the above object, the present invention comprises a shoe for holding a probe main body at a predetermined angle with respect to the surface of an object to be inspected. In an ultrasonic probe that performs ultrasonic inspection by bringing a probe surface of a main body into contact with the main body, a shoe member divided into a plurality of pieces and arranged along an outer edge of the probe main body, and the shoe member is provided with the shoe member. A supporting means for slidably supporting in a direction substantially perpendicular to an inspection surface, an urging means for urging the shoe member against the surface to be inspected, and an outer edge of the shoe member; Closing means for contacting the inspection surface to make the inside of the contact portion a substantially closed space; and a liquid flaw detection medium in the closed space including a contact portion between the inspection surface and the inspection surface of the probe body. Supply means for supplying the probe, and the probe surface of the probe is brought into contact with the surface to be inspected. When performing the flaw detection, the shoe member slides following the surface shape of the inspection object, holds the probe at a predetermined angle, and furthermore, the flaw detection medium is at least a probe surface of the probe. And the surface to be inspected.

In this case, the closing means may be constituted by a skirt having flexibility, for example, a skirt made of an elastic synthetic resin material or rubber. Further, the supply means includes a supply hole passing from the support means through the shoe member and communicating with a contact portion of the shoe member to the surface of the object to be inspected, and from the supply hole to a probe surface of the probe. A liquid flaw detection medium is supplied between the surface and the surface to be inspected. Therefore, a contact portion of the supply hole with the surface of the inspection object is opened toward the ultrasonic probe main body. In addition, a guide member is provided in a slide portion between the shoe member and the support means, and the movement between the two is smoothly performed.

[0010] The support means may be formed integrally with the probe main body.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing a cross section of a part of an ultrasonic probe according to an embodiment of the present invention, FIG. 2 is a bottom view of FIG.
FIG. 2 is a sectional view taken along line AA of FIG. 2, and the same reference numerals are given to the same portions as those in the conventional example shown in FIG. 7, and the overlapping description will be omitted.

In FIG. 1, a shoe 4 has a holder 10 as a support means and a slide piece 1 as a shoe member.
5 A mounting hole 10c into which the probe 1 is inserted is formed in a central portion of the holder 10. The probe 1 is inserted to a predetermined depth of the mounting hole 10c, and is fixed together with the casing 12 by a bolt 11. You. At this time, the slide piece 15 is placed between the casing 12 and the holder 10.
Is slidably held. For this reason, a guide member 13 is provided between the slide piece 15 and the holder 10 so that the slide piece 15 and the holder 10 can slide smoothly and can move parallel to the axis O of the probe 1.

As shown in FIG.
As can be seen from FIG. 3 which is a sectional view taken along the line AA in FIGS. 1 and 2, an engaging projection 15 d is provided on the outer peripheral side of the upper end portion, and is provided on the inner peripheral side of the lower end portion of the casing 12. The projection 12a is engaged with the projection 12a provided to prevent the projection 12a from falling off and to restrict the downwardly projecting position. Thus, the slide piece 15 is slidably held in the gap 14 formed by the holder 10 and the casing 12.

The first inner surface 15i1 of the slide piece 15
Is in contact with a roller (or a ball) of the guide member 13 (not shown), and the second inner surface 15i2 is in contact with the outer peripheral surface of the holder 10. The first outer surface 15o1 of the slide piece 15 is in contact with the inner surface of the casing 12. The second outer surface 15o2 of the slide piece 15 faces the protrusion 12a with a predetermined gap, and is intended to smoothly slide. Slide piece 1
The fifth third outer surface 15o3 is formed as a surface that spreads outward. In addition, the probe surface 1a is formed in a planar shape, and the lower surface 15u of the slide piece 14 is formed in accordance with the assumed shape of the flaw detection surface of the inspection object 6. In the case of this embodiment, it is formed to have the same curvature as the inner surface of the inspection object 6. When the lower surface 15u and the probe surface 1a are in contact with the inner surface of the test object 6 which is uniform (ie, has no irregularities), the distance between the upper surface 15c of the slide piece 15 and the first lower surface 10b of the holder 10 is L1. The distance between the upper end of the second outer surface 15o2 and the upper surface of the flange 12a is L2. This distance is the maximum movement distance of the slide piece 15, in other words, the maximum setting dimension of the unevenness on the inspection surface is set to, for example, about 6 mm. A skirt 16 made of a material having flexibility and elasticity, for example, rubber, is provided on the third outer surface 15o3.
Are fixed by bolts 17.

As shown in FIG. 2, each of the four slide pieces 15 has an interval 19 for allowing a slide operation (the interval 19 may be 0 if the frictional force is small), and the four slide pieces 15 are attached to the side surfaces of the adjacent slide pieces 15 respectively. Are facing each other. Then, as shown in FIG. 3, the counterbore hole 10a provided in the holder 10 and the counterbore hole 1 provided in the slide piece 15 are provided.
A spring 20 is disposed between the slide piece 5a and the slide piece 5a to elastically urge the slide piece 15 in a direction along the axis O. The spring 20 is set to a length that elastically urges the slide piece 15 downward even when the engagement projection 15d of the slide piece 15 contacts the projection 12a of the casing 12.

The counterbore 10a communicates with the joint 21 via a supply hole 10d. The hose 22 fixed to the joint 21 is connected to a supply source of a couplant (not shown). The joint 21 is fixed to the holder 10 by a bolt 23. The counter bore 15a is the supply hole 15
It communicates with the groove 15m provided on the lower surface via b.

When ultrasonic flaw detection is performed using the probe 1 configured as described above, the probe surface 1a of the probe 1 is brought into contact with the flaw detection surface of the inspection object 6 by means not shown. Then, the lower surface 15u of the slide piece 15 abuts on the surface of the inspection object 6 while being urged by the spring 20. At this time, the skirt 16 also elastically contacts the surface of the inspection object 6. In this state, when operating the couplant source,
The couplant supplied via the hose 22 is connected to the supply hole 1
0d, the counterbore 10a, the gap 14, the counterbore 15a, the hole 15b, and the groove 15m are supplied to the vicinity of the probe surface 1a through the gap, and at least the space between the probe surface 1a and the surface of the inspection object 6 is filled. Is done. The skirt 16 has an edge contacting the surface of the inspection object 6 to form a substantially closed space, and restricts the outflow of the couplant. In this state, the probe 1 is moved, and the inside of the inspection object 6 is inspected by ultrasonic waves. Therefore, at the time of actual inspection, the inside of the skirt 16 is filled with the couplant.

FIG. 4 is a diagram showing the operation of the probe 1 according to the present embodiment when the surface of the inspection object 6 has a concave portion. Since the surface of the inspection object 6 is flat, the lower surface 15u of the slide piece 15 is formed flat. However, the lower surface 15u abuts on the surface of the inspection object 6 and keeps the attitude of the probe 1 constant. As long as the skirt 16 does not lose its function of holding the closed space by elastically contacting the surface of the inspection object 6, the skirt 16 may be formed with a predetermined curvature as shown in FIG. In particular, the shape of the lower surface 15u of the slide piece 15 is not limited.

FIG. 2 shows a state in which the probe 1 having moved the surface of the surface 6 to be inspected has reached the vicinity of the center of the concave portion 6a. The flaw detection surface 1a is in contact with the surface of the concave portion 6a by an urging means (not shown). Further, the left and right slide pieces 15 in the drawing are in contact with the surfaces of the opposing concave portions 6a by the springs 20, respectively. As described above, since the probe 1 and the slide piece 15 independently move in the vertical direction following the surface of the inspection object 6, the probe surface 1a
Does not separate from the surface of the inspection object 6. The skirt 16 also moves up and down as the slide piece 15 moves up and down. However, the edge of the skirt 16 always elastically comes into contact with the surface of the inspection object 6 to maintain the closed space. As it works, the couplant can minimize leakage from the skirt 16.

The moving distance L of the slide piece 15
Although (the value obtained by adding L1 and L2) depends on the size of the probe 1 and the shoe 4, it is practically set to about 6 mm as described above, and slides during this. Since the guide member 13 is provided so as to be able to follow the sliding movement of the slide piece 15, various irregularities formed on the surface of the inspection object 6 can be handled.

The skirt 16 may be provided for each slide piece 15 as long as a substantially closed space can be formed, or one skirt 16 may be provided as a whole.

Although the holder 10 is configured to be detachable from the probe 1, the probe 1 and the holder 10 may be formed integrally. In addition, the guide member 13 need not be provided as long as a sufficient following function can be achieved without providing the guide member 13. Further, in the embodiment shown in FIG. 1, the surface of the inspection object 6 is substantially concave, and in the embodiment shown in FIG. 4, the surface of the inspection object is substantially flat. Is the same even when is a substantially convex surface. In this case, it is more preferable that the shape of the lower surface 15u of the slide piece 15 be concave in accordance with the curvature of the inspection object 6.

FIG. 5 is a front view of an essential part of an ultrasonic flaw detection test apparatus for performing flaw detection using the ultrasonic probe according to the present invention.
In the figure, the probe 1 is held by a support 40,
It is pressed against the surface of the inspection object at a predetermined pressure in a direction along the axis O. The support 40 is held by a hollow shaft 41,
The hose 22 is inserted into the shaft 41, and the end is connected to a supply source of a couplant (not shown). The shaft 41 is supported by the base 42 so as to be movable in the vertical direction. Base 4
A guide 43 is erected on 2 in parallel with the shaft 41. The screw shaft 44 is parallel to the guide 43 and the base 4
2 and the upper plate 45 rotatably supported. A handle 46 is attached to the end of the screw shaft 44 so that the screw shaft can be rotated through the handle 46. The plate 47 fixed to the end of the shaft 41 is fitted to the guide 43 and screwed to the screw shaft 44.

The base 42 is rotatably supported by the seat 50. When the handle 51 is rotated, the base 42 is configured to rotate about the axis P of the shaft 41. The seat 50 is fixed by bolts 52 so that the axis P coincides with the center of the branch pipe 53. The branch pipe 53 is welded to the main pipe 54.

With the above-described structure, the probe 1 is positioned at a site to be flaw-detected by appropriately rotating the handle 46 and the handle 51, and the presence or absence of an internal defect in the welded joint is inspected. can do. In addition,
In the example shown in FIG. 5, the inspection object 6 (branch tube 53) is configured to move in the axial direction and the circumferential direction by the operation of the handles 46 and 51. It is also possible to move by other drive devices, and when moving by these drive devices, it is also possible to provide a separate control device and automatically perform flaw detection. In this case, the CPU of the control device
The control is executed according to the input condition according to the program written in M.

[0027]

As described above, according to the present invention,
When the probe is in contact with the surface to be inspected to perform a flaw detection, the shoe member slides independently along the surface shape of the object to be inspected, and follows the surface shape, and the probe is moved to a predetermined position. And the flaw detection medium is held at least between the probe surface of the probe and the surface to be inspected. Will be possible. At this time, the distance between the probe and the surface of the object to be inspected is kept constant while the medium for flaw detection is held at least between the surface to be inspected and the surface to be inspected. Of the ultrasonic wave becomes uniform, and the inspection accuracy can be improved.

Further, according to the present invention, since the closing means is constituted by a skirt having flexibility and / or elasticity, a liquid flaw detection medium can be held in the skirt, and the probe surface A medium for flaw detection can always be interposed between the test piece and the surface of the object to be inspected, thereby ensuring accurate ultrasonic flaw detection.

According to the invention, the supply means includes a supply hole passing from the support means through the shoe member and communicating with a contact portion of the shoe member with the surface of the object to be inspected. Since the contact portion with the object surface is open to the ultrasonic probe main body side, the medium for flaw detection can be reliably supplied between the probe surface and the surface of the inspection object.

Further, since a guide means for smoothly moving the shoe member is provided in the slide portion between the shoe member and the support means, the sliding operation of the shoe member is not impaired. It is possible to follow the surface shape of the flaw detection object.

Further, since the support means is formed integrally with the probe main body, the number of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a partially sectional front view of an ultrasonic probe according to an embodiment of the present invention.

FIG. 2 is a bottom view of the ultrasonic probe of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a diagram showing a flaw detection state of the probe according to the embodiment of the present invention when a concave portion is present on the surface of the inspection object.

FIG. 5 is a front view of a main part of the ultrasonic flaw detector when flaw detection is performed using the probe according to the embodiment of the present invention.

FIG. 6 is a view for explaining a state at the time of flaw detection of a conventional ultrasonic probe.

FIG. 7 is a diagram showing a flaw detection state of a conventional probe when there is a concave portion on the surface of the inspection object.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 probe 1a flaw detection surface 4 shoe 10 holder (holding means) 10a, 15a counter bore 10d supply hole 12 casing 13 guide member (guide means) 14 gap 15 slide piece (shoe member) 15b hole 15m groove 15u bottom surface 16 skirt (Closing means) 20 spring (biasing means) 22 hose O axis

Claims (6)

[Claims] An ultrasonic flaw detection is performed by providing a shoe for holding a probe main body at a predetermined angle with respect to the surface of an object to be inspected, and bringing a probe surface of the probe main body into contact with a surface to be inspected. In the ultrasonic probe, a shoe member divided into a plurality of pieces and arranged along an outer edge of the probe main body, and the shoe member is slidably supported in a direction substantially perpendicular to the surface to be inspected. Supporting means, urging means for urging the shoe member against the surface to be inspected, provided at an outer edge of the shoe member, contacting the surface to be inspected, substantially closing the inside of the contact portion with a closed space. Closing means for supplying, a supply means for supplying a liquid flaw detection medium to the closed space including a contact portion between the surface to be inspected and the surface to be inspected of the probe main body, When performing flaw detection by bringing the probe surface into contact with the surface to be inspected, the shoe member Ultrasonic probe is characterized in that slide to follow the object surface shape. 2. An ultrasonic probe according to claim 1, wherein said closing means comprises a skirt having flexibility and / or elasticity. 3. The supply means according to claim 1, wherein said supply means includes a supply hole passing through said shoe member from said support means and communicating with a contact portion of said shoe member to a surface of an object to be inspected. Ultrasonic probe. 4. The ultrasonic probe according to claim 3, wherein a contact portion of the supply hole with the surface of the inspection object is opened to the ultrasonic probe main body side. 5. The slide unit between the shoe member and the support means is provided with guide means for smoothly moving the shoe member. Ultrasonic probe. 6. The ultrasonic probe according to claim 1, wherein said support means is formed integrally with said probe main body.