JP7742013B2 - Ultrasonic flaw detection equipment - Google Patents

Description

The present invention relates to an ultrasonic flaw detector capable of inspecting an object for flaws, defects, etc.

In a typical ultrasonic probe, a piezoelectric element (vibrator) is cut into a thin, flat plate, and ultrasonic waves are generated by applying a voltage to this piezoelectric element, causing it to vibrate. Specifically, as shown in Figures 8A and 8B, vibrators 16A and 16B are positioned perpendicular or oblique to the surface of the object being inspected, and ultrasonic waves are transmitted or received in one direction from vibrators 16A and 16B to inspect the object. The former instrument is called a perpendicular probe 15A, and the latter instrument is called an angle beam probe 15B.

In this case, ultrasonic waves propagate in a fixed direction to detect flaws in the inspection object 110. For other regions of the inspection object 110, the ultrasonic probe is moved to perform flaw detection in desired regions.
Furthermore, in the technical field of flaw detection in which a vibrator is brought into close contact with the surface to be inspected of an object to be inspected, a technology has been proposed in which a flexible vibrator is used to deform the shape of the vibrator to fit the surface to be inspected, and an ultrasonic probe is fixed in that position to enable flaw detection when the surface to be inspected is not flat (Patent Document 1).

Registered Utility Model Publication No. 3191253

However, when detecting flaws in an object to be inspected, the ultrasonic probe may be moved to target a specific area, but the technology proposed in Patent Document 1 does not allow flaws to be detected while moving the ultrasonic probe, regardless of whether the surface to be inspected of the object to be inspected is flat or not.
Furthermore, with vertical probes and angled probes, it is possible to perform flaw detection in a specified area even on a non-flat flaw detection surface by moving the ultrasonic probe along the flaw detection surface. However, as shown in Figure 9, when an attempt is made to move the vertical probe 15A or the like to adjust its position or angle to match the flaw detection surface, there is a problem that the moving tool or moving device may interfere with the object being inspected by rotating the probe, making movement difficult and making it impossible to perform flaw detection.

The present invention has been made in light of the above circumstances, and has as its object to provide an ultrasonic flaw detection device that is capable of detecting flaws regardless of the shape of the flaw detection surface of the object to be inspected.

That is, a first embodiment of the ultrasonic flaw detection device of the present invention includes an ultrasonic probe arranged on the inner surface side of an object to be inspected having an arc-shaped cross section, a receiving probe arranged on the outer surface side of the object to be inspected, a probe moving unit that moves the ultrasonic probe, and a receiving moving unit that moves the receiving probe,
The ultrasonic probe has a vibrator arranged in a convex shape and an electrode that applies a voltage to the vibrator to generate ultrasonic waves on the outer periphery of the vibrator,
the probe moving unit is provided with the ultrasonic probe at its tip end, and moves the ultrasonic probe linearly in an X direction, which is a direction toward or away from the flaw detection surface of the object to be inspected, and in a Y direction, which is perpendicular to the X direction, on a plane along the cross-sectional arc shape, and moves the ultrasonic probe to a position appropriate for flaw detection relative to the object to be inspected by the X direction movement and the Y direction movement;
The receiving moving unit determines a position according to the position of the ultrasonic probe and a position of the object to be inspected, and moves the receiving probe.

In another aspect of the invention of the ultrasonic flaw detection device , in the above aspect of the invention, the convex surface of the ultrasonic probe is an arcuate surface.

In another aspect of the invention of the ultrasonic flaw detection device , in the above-mentioned aspect, the arcuate surface of the ultrasonic probe is an ellipsoidal surface or a circular arcuate surface.

In another aspect of the invention of the ultrasonic flaw detection device , in the above aspect of the invention, the vibrators are arranged in an angular range of more than 180 degrees.

In another aspect of the invention of the ultrasonic flaw detection device , in the above aspect of the invention, the ultrasonic probe is arranged such that the surface of the convex vibrator faces rearward on the rear side of the vibrator.

In another aspect of the invention of the ultrasonic flaw detector , in the above aspect of the invention, the vibrator is formed as a single unit.

In another aspect of the invention of the ultrasonic flaw detection device , in the above aspect of the invention, the transducer is a phased array.

In another aspect of the invention of the ultrasonic flaw detection device , in the above aspect of the invention, the transducer has an outer surface that has a concave shape in a cross section along the axial direction of the convex shape.

In another aspect of the invention of the ultrasonic flaw detection device , in the above aspect of the invention, the ultrasonic probe has an arc-shaped recess.

In another aspect of the invention of the ultrasonic flaw detection device , in the above aspect of the invention, the transducer has a shape in which the arc-shaped center of curvature is located on the outer side of the transducer.

According to the present invention, ultrasonic waves are propagated outward over a wide range by the convexly arranged transducer, allowing flaw detection over a wide area of the object being inspected. Furthermore, by simplifying the range of movement of the ultrasonic probe, it is possible to prevent the moving tool or moving device from interfering with the object being inspected, etc.

1 is a partially cross-sectional front view of an ultrasonic flaw detection device according to an embodiment of the present invention. FIG. FIG. FIG. 10 is a diagram showing the ultrasonic probe connected to the moving device. FIG. 10 is a diagram showing ultrasonic wave propagation from an ultrasonic probe. FIG. 10 is a diagram showing the arrangement of an ultrasonic probe relative to an object to be inspected. 10 is a diagram for explaining the state in which the ultrasonic probe is used with respect to an object to be inspected. FIG. FIG. 10 is a partially cross-sectional front view of an ultrasonic flaw detector according to another embodiment of the present invention. FIG. 10 is a front view showing a schematic structure of an ultrasonic flaw detection device according to still another embodiment of the present invention. FIG. 1 is a diagram showing a schematic structure of a vertical probe in the related art. FIG. 1 is a diagram showing a schematic structure of an angle beam probe in the related art. FIG. 1 is a diagram illustrating a state of use in the related art.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
1A to 1C, the ultrasonic probe 1 has a ceramic vibrator 2 (piezoelectric element) with a curvature in cross section (arc shape) disposed at the tip of a stainless steel cylindrical main body 10 via a support member 11. In this example, the vibrator 2 is integrally formed as a curved molded product.
The transducer 2 has a shape that spans an angular range of more than 180 degrees and is partially open. The open side of the transducer 2 is positioned on the main body 10 side, and the front and side of the ultrasound probe are covered by the arc of the transducer 2. On the side, the transducer 2 extends slightly rearward.
The inside of the vibrator 2 is filled with a sound-absorbing material 3 made of epoxy resin, giving it a cylindrical shape. Note that the shape and material of the main body 10 are not limited to those described above, and the materials of the vibrator 2 and the sound-absorbing material 3 are also not limited to those described above.

A thin matching layer 4 made of epoxy resin is arranged along the surface of the transducer 2 on the surface side of the transducer 2, increasing the transmittance of ultrasound to the object to be inspected. The matching layer 4 in contact with the transducer 2 is exposed on the front and side sides within an angular range of more than 180 degrees, just like the transducer 2, with the spacing between the opposing transducers narrower on the base end side than on the front, and the vibration surface facing diagonally backward on the rear side. The material of the matching layer 4 is not limited to the above.
On both axial sides of the vibrator 2, sound-absorbing material 3, and matching layer 4, side plate portions of the support portion 11, which are connected to the main body 10 via the damper 5, are located and support the vibrator 2, sound-absorbing material 3, matching layer 4, and damper 5 from both sides.
In this embodiment, the vibrator 2 is an essential component, but the other components described above can be selected arbitrarily.

As shown in FIG. 1B, electrodes 7 and 8 are connected to the vibrator 2, with the electrode 7 connected to the main body 10 (ground side) and the electrode 8 extending outside the main body 10 and connected to a power supply (not shown).
A threaded connection portion 12 is formed on the base end side of the main body 10, and is connected to a moving device 20 as shown in FIG. 2. The moving device 20 can move the ultrasound probe 1 in the X and Y directions, for example, so that the distance between the object under test 100 and the transducer 2 is kept constant. In the moving device 20, movement and control of movement can be performed by a driving unit (not shown) and a control unit that controls the driving unit. Furthermore, the moving device or moving tool may be moved manually. The moving device 20 corresponds to the probe moving unit of the present invention.
The ultrasonic probe 1 and the moving device 20 constitute an ultrasonic flaw detection device 30 of this embodiment.

In the ultrasonic probe 1, when a voltage is applied between the electrodes 7 and 8, vibrations occur in the transducer 2, and as shown in Figure 3, ultrasonic waves are generated and propagated over a range of more than 180 degrees on the entire front surface and part of the rear surface on the outer surface.
By placing this ultrasonic probe 1 inside an object to be inspected 100 whose inner surface is a concave curved surface as shown in Fig. 5, ultrasonic waves can be propagated evenly over a wide range. When using ultrasonic flaw detection in a transmission type, it is important to irradiate the object to be inspected with ultrasonic waves at an appropriate position and angle, but the ultrasonic probe of this embodiment makes it possible to irradiate ultrasonic waves at an appropriate angle even if the flaw detection position on the object to be inspected changes.

In actual measurements, the receiving probe 40 is placed outside the object under test 100 and is movable. The receiving probe 40 is movable using a receiving movement device (not shown). In this example, there are almost no restrictions on the movement of the receiving probe 40 outside the object under test 100.

At this time, ultrasonic waves are incident perpendicularly on the object under test 100 from the ultrasonic probe 1, and the ultrasonic waves that have passed through the object under test 100 are received by the receiving probe 40. The inspection can be performed by a transmission method performed in water to improve the propagation of ultrasonic waves. That is, in this embodiment, flaw detection is performed by a transmission method using the water immersion method, but the medium through which ultrasonic waves pass is not limited to water, and oil or the like may also be used. Note that this does not exclude methods that do not require immersion.
4, in this embodiment, ultrasonic waves are propagated radially over a wide range, so that the moving device 20 can be moved in the X and Y directions to an appropriate position relative to the object under test 100. Furthermore, if the receiving probe 40 is positioned according to the position of the ultrasonic probe 1 and the position of the object under test 100 to be inspected, it becomes possible to receive ultrasonic waves that have passed through the object under test 100 almost perpendicularly and perform inspection.

In this embodiment, the moving device 20 for moving the ultrasonic probe 1 can be moved simply (for example, in the X and Y directions), making it possible to avoid interference between the moving device 20 and the object under test 100 and perform flaw detection at the desired position without considering interference. The receiving probe 40, which has no movement restrictions, can be moved with rotation to allow ultrasonic waves to be incident at the appropriate angle.

In this embodiment, the description is given assuming that flaw detection is performed on an object 100 to be inspected that has an internal curved surface, and this embodiment provides significant benefits for objects of this shape. However, this embodiment is not limited to objects of a specific shape, and can also be applied to objects of a flat shape. In this case, since ultrasonic waves are propagated over a wide range of angles, flaw detection can be performed over a wide area at once.
In addition, in the above embodiment, the outer surface perpendicular to the axial direction of the curved surface is described as having a curved surface in only one direction, and the outer surface perpendicular to the axial direction of the curved surface is described as having a flat surface, but the outer surface that intersects with the axial direction may also have a convex shape.
In addition, although the convex surface is described as being formed as an arc surface in this embodiment, it may be formed as an elliptical surface or a curved surface, or the contour of the convex surface may be partially or entirely polygonal. In these modified examples, it is also desirable to make the spacing between the transducers smaller at the base end side than at the tip end side, and to have the rear transducer surface facing rearward to widen the radiation range.

In the above embodiment, flaw detection was performed by transmitting ultrasonic waves, but a reflective type in which ultrasonic waves are reflected and received is also possible, as long as they can be received by the ultrasonic probes 1, 1A, and 1B.

(Embodiment 2)
Next, another embodiment will be described with reference to FIG.
In the above embodiment, the transducer has an arcuate shape with a flat surface in the axial direction, but the ultrasonic probe 1A of this embodiment uses a transducer 2A having an outer surface with an arcuate shape in a cross section along the axial direction. The arcuate surface can be configured with an appropriate surface taking into consideration the distance from the object to be inspected, etc. The arcuate outer surface is one form of an outer surface with a concave shape.
As in the first embodiment, the vibrator 2A is made of ceramic and has a cross-sectional arc shape with a curvature in a cross section perpendicular to the axial direction, at the tip side of the main body 10A which is a cylindrical body made of stainless steel.

The vibrator 2A has an angular range of 180 degrees or more, and the inside of the vibrator 2A is filled with a sound absorbing material 3A made of epoxy resin.
A thin matching layer 4A made of epoxy resin is disposed on the surface of the vibrator 2A along the surface of the vibrator 2A.
Dampers 5A are positioned on both sides of the vibrator 2A, sound-absorbing material 3A, and matching layer 4A, and the vibrator 2A, sound-absorbing material 3A, matching layer 4A, and damper 5A are supported by the side plates of a support plate 11A that is connected to the main body 10A on the outside of the damper 5A.

An electrode (not shown) is connected to the transducer 2A, and ultrasonic waves are generated by applying a voltage to the transducer 2A via the electrode.
A threaded connection portion 12A is formed on the base end side of the main body 10A and is connected to a moving device (not shown).
The ultrasonic probe 1A and the moving device constitute the ultrasonic flaw detection device of this embodiment.

In ultrasonic probe 1A, the shape of transducer 2A is arcuate in a cross section along the axial direction, and ultrasonic waves generated by the transducer are focused forward and inward in the axial direction. Therefore, ultrasonic waves can be incident at a high radiation density on the test object at the front of ultrasonic probe 1A, preventing dispersion of ultrasonic waves in the axial direction, thereby improving flaw detection accuracy. For example, if flaw detection is performed near the center of curvature of the arc shape, the ultrasonic propagation density can be maximized.

(Embodiment 3)
Furthermore, in each of the above embodiments, the transducer is described as being integrally molded, but as shown in FIG. 7, a phased array transducer 2B is used, and flaw detection can be performed by an ultrasonic probe 1B in which multiple transducers 2B are arranged in a convex shape.
Electrodes may be connected to each transducer 2B so that only the necessary transducers 2B generate ultrasound, or some of the transducers 2B may be grouped together to generate ultrasound.Furthermore, ultrasound may be turned on and off across all of the transducers.

The present invention has been described above based on the above embodiment, but the present invention is not limited to the content of the above embodiment, and appropriate modifications to the above embodiment are possible without departing from the scope of the present invention.

REFERENCE SIGNS LIST 1 Ultrasonic probe 1A Ultrasonic probe 1B Ultrasonic probe 2 Oscillator 2A Oscillator 2B Oscillator 3 Sound absorbing material 3A Sound absorbing material 4 Matching layer 4A Matching layer 5 Damper 5A Damper 10 Main body 11 Support part 12 Screw-in connection part 20 Moving device 30 Ultrasonic flaw detection device 40 Receiving probe 100 Inspection object

Claims (10)

The ultrasonic wave probe is arranged on the inner surface side of an object to be inspected having an arc-shaped cross section, a receiving probe is arranged on the outer surface side of the object to be inspected, a probe moving unit that moves the ultrasonic probe, and a receiving moving unit that moves the receiving probe,
The ultrasonic probe has a vibrator arranged in a convex shape and an electrode that applies a voltage to the vibrator to generate ultrasonic waves on the outer periphery of the vibrator,
the probe moving unit is provided with the ultrasonic probe at its tip end, and moves the ultrasonic probe linearly in an X direction, which is a direction toward or away from the flaw detection surface of the object to be inspected, and in a Y direction, which is perpendicular to the X direction, on a plane along the cross-sectional arc shape, and moves the ultrasonic probe to a position appropriate for flaw detection relative to the object to be inspected by the X direction movement and the Y direction movement;
The receiving moving unit moves the receiving probe by determining a position according to the position of the ultrasonic probe and a position of the object to be inspected. The ultrasonic flaw detection device of claim 1, wherein the convex surface of the ultrasonic probe is an arcuate surface. The ultrasonic flaw detection device of claim 2, wherein the arcuate surface of the ultrasonic probe is an ellipsoid or a circular arc. The ultrasonic flaw detection device of claim 3, wherein the transducers are arranged over an angular range of more than 180 degrees. The ultrasonic flaw detection device according to any one of claims 1 to 4, wherein the ultrasonic probe is configured such that the surface of the convex vibrator faces rearward on the rear side of the vibrator. An ultrasonic flaw detector according to any one of claims 1 to 5, wherein the vibrator is integrally formed. An ultrasonic flaw detection device according to any one of claims 1 to 5, wherein the transducer is a phased array. The ultrasonic flaw detection device according to any one of claims 1 to 7, wherein the transducer has an outer surface with a concave shape in a cross section along the axial direction of the convex surface. The ultrasonic flaw detection device of claim 8, wherein the recessed portion of the ultrasonic probe has an arcuate shape. The ultrasonic flaw detection device of claim 9, wherein the transducer has a shape with the arc-shaped center of curvature on the outer side of the transducer.