JPS59180456A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To enable quick and free-from-overlooking detection all over a material subject to detection by joining a ultrasonic wave sending and receiving end of a polygonal column with a shoe which corresponds virtually in a poligonal column fashion to it and shaped virtually in a polygonal cone fashion and provided with a solid curve on its end. CONSTITUTION:On each side surface of a guide rod 2 shaped in a virtually square column of a rectangular section is jointed with a supersonic wave sending end receiving unit 1A-1D respectively. The supersonic wave sending and receiving unit 1 is jointed with the guide rod 2 in consideration of refraction angle to the guide rod 2 in such a way that surface wave is produced on its surface. On a solid wave end 2a is jointed tightly along the solid curve with an end shoe 3 of square cone which corresponds to shape and dimension of the guide rod 2. The solid curve end 2a of the guide rod 2 is provided with a shape in such a way that a surface wave from the ultrasonic wave sending and receiving unit 1 is convergent to the end portion 3a of the end shoe 3 at the joint surface with the end shoe 3 by the principle of refraction of supersonic wave.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses ultrasonic flaw detection to detect material defects on the surface and sides of structural members, etc., using ultrasonic flaw detection. The present invention relates to an ultrasonic probe.

[Technical background of the invention]

BACKGROUND ART Liquid dye flaw detection and magnetic particle flaw detection have conventionally been used to detect defects on and near the surface of structural members and the like. These methods are effective in that the entire material surface can be visually inspected, but liquid dye flaw detection cannot adequately detect defects unless they are open on the material surface. /J% If the parts are small or in close contact, defects may be overlooked. In addition, the magnetic particle flaw detection method cannot be applied to non-magnetic materials, and in addition to poor workability in terms of processing small magnetic particles, it may sometimes scratch the surface of the product.

On the other hand, ultrasonic flaw detection is also used to detect surface defects and shallow defects using surface waves; This has led to difficulties in detecting ultrasonic signals from defects with high precision.

In other words, conventional ultrasonic flaw detection methods for surface waves required surface waves to be incident on the surface of the specimen through a liquid couplant, such as glycerin, on the surface of the specimen. The surface waves are dispersed on the surface of the material to be inspected, and depending on their dispersion information, position, etc., they become reflection sources for surface waves, and the level of the reflected waves is also transmitted as various complex noise signals. In addition, conventional surface wave probes have a specific directivity in the surface wave transmission direction in order to narrowly limit the flaw detection area in advance and perform tests, etc., in the same way as normal angle probes. is given. For this reason, when surveying the entire surface of a material to be inspected, it is necessary to transmit and receive ultrasonic waves individually in various directions.

When the direction in which a material surface defect occurs is uncertain or unknown, in order to sufficiently absorb the reflected waves from the defect,
In order for the ultrasonic waves to be efficiently incident on the defective surface, it was necessary to select various directions for transmitting and receiving the ultrasonic waves and repeat them deep into the defect surface.

Therefore, there is a problem in that an enormous amount of time is required for inspection and defects are often overlooked.

C. Object of the Invention The object of the present invention is to provide an ultrasonic probe for surface waves that is capable of detecting the entire area of the entrance surface on the subject side without missing anything. There is a particular thing.

[Implantation of the Invention J The present invention provides that on each side of a polygonal column having a shape of a polygonal column,
Ultrasonic transmitters and receivers for surface wave velocity and reception are respectively attached with the ultrasonic wave transmission and reception directions set in the same direction along the axial direction of the polygonal column member.・At the end of the wave receiving direction, a seam having a substantially polygonal pyramid shape corresponding to the polygonal prism shape and having a curved tip is joined to the end portion in the wave receiving direction, and the joining surface of the polygonal prism member and the seam is made from the polygonal prism member. The advantage is that it is formed into a curved surface that allows the sound waves to converge almost at the tip of the tip.

[Embodiments of the invention]

The configuration of one embodiment of the present invention is shown in FIG.

Figure 1 shows an ultrasonic transmitter/receiver 1 similar to that used in a normal surface wave ultrasonic probe attached to each side of a guide rod 2, which is a polygonal column member having an approximately polygonal column shape. This is an embodiment in which an ultrasonic transmitter/receiver 1 (lA
~7D) are adhered.

In addition, the polygonal column member constituted by the guide rod 2 is generally the side of the column whose cross-sectional shape is approximately polygonal, and it is possible to attach the ultrasonic transmitter/receiver 1 to each side of the periphery. It can be implemented in any shape.

The ultrasonic transmitter/receiver l is glued in consideration of the refraction angle to the guide rod 2 so as to generate surface waves on the surface of the guide rod 2, and each ultrasonic transmitter/receiver 1A -IDI
d Curved portion 2a of the guide plate 2 in the direction of transmitting and receiving ultrasonic waves
The frequency characteristics of the arrangement are almost the same as you move towards the top.

In this case, the guide rod 2 is made of stainless steel, for example. The material of this guide plate 2 does not necessarily have to be stainless steel, and may be other metal or non-metallic materials, but from the viewpoint of use, it is preferable to use an anti-corrosive material that is resistant to rust etc. .

A substantially quadrangular pyramid-shaped tip seam 3 corresponding to the shape and dimensions of the guide rod 2 is tightly joined to the curved surface portion 2a of the guide rod 2 along the curved surface. In this case, the material of the tip seam 3 is, for example, acrylic material, but as with the guide rod 2, other metals or di-metal materials may be used as long as the material does not rust or deteriorate during use. For example, ceramic coatings can also be used.

Here, the curved surface portion 2a of the guide rod 2 allows the surface waves from the ultrasonic wave transmitter/receiver 1 to be refracted at the junction surface with the tip no. 3. tip 3a of
It is a requirement in the present invention that the shape converges to the shape of the curved surface portion 2a, and the shape of the curved surface portion 2a is determined as follows.

That is, as shown in FIG.
2, the radius r of the curved surface portion 2a is given by the following equation.

Here, f is the focal length from the curved surface section 3 when the ultrasonic wave from the ultrasonic transmitter/receiver l is refracted and converged at the curved section 2a. The length t is set approximately equal to this f.

Therefore, in the present invention, it is necessary that the surface wave sound velocities of the force-id rod 2 and the tip sony 3 are different. However, it is clear that the closer the acoustic impedances of the two are to the same, the better, since surface wave reflection is less likely to occur at the root surface shape portion 2a that is close to the same. In addition, in this example, since CI>C2, the curved surface portion 2 of the guide rod 2
Although a is concave, it is clear that if the materials of both are selected such that Ct < C2, the curved portion 2a will be convex, and of course it can also be implemented in this manner.

Next, the structure of adhering the ultrasonic transmitter/receiver 1 to the guide rod 2 will be explained.

That is, as shown in Fig. 3, the ultrasonic transmitter/receiver l is glued to the side surface of the guide rod 2 at a distance a from the curved surface portion 2a, and this distance a is set such that it satisfies the following equation. selected.

a≦D2/4λ ・・・・・・・・・
(2) Here, D is the width of the transducer in the ultrasonic transmission/reception direction of the ultrasonic transmitter/receiver l, and λ is the wavelength of the surface wave in the guide rod 2. That is, the above equation (1) is generally a relational equation when a plane wave enters the tip end 3 from the guide rod 2 via the curved surface portion 2a, but in this embodiment, in order to approximately satisfy this condition, the surface The aim is to converge the ultrasonic waves within the livestock area close to the waves. Therefore, as long as the above formula (2) is satisfied, this embodiment is effective, but the closer the ultrasonic transmitter/receiver l is to the curved portion 2a, the more effective it is in order to improve the transmitting and receiving sensitivity. However, if they are brought extremely close together, the echoes reflected from the curved surface portion 2a will affect the deglazing process, so there is a risk that the effectiveness will be lost.

Note that the tip 3a of the tip seam 4 has a substantially parabolic curve ll11 formed by gathering polygonal pyramidal slopes, and the curved surface is brought into smooth, almost point contact with the test material. It is structured as follows. It is desirable that the probe configured in this manner be brought into vertical contact with the surface of the material to be tested, and if necessary, a jig or the like may be attached for vertical contact.

Next, the effects of the ultrasonic probe configured as described above will be explained with reference to FIGS. 4 and 5.

For example, when each ultrasonic transmitter/receiver l shown in FIG. 1 is used for wave transmission or for both transmission and reception, the emitted surface waves pass through point A shown in FIG. 4 and are refracted at the curved surface portion 2a. As the sound pressure approaches points B and C along the surface of the tip sea-3 and the tip 3a, the sound pressure increases due to the focusing effect. here,
The surface waves WS8 to WSd from each of the four ultrasonic transmitter/receivers IA to ID in this embodiment have the same frequency and the same distance to the tip 3a, as shown in FIG. Near the tip 3a, they are in phase with each other. Therefore, at the tip portion 3a, the four surface waves wSa to WSd are superimposed to form a high-amplitude surface wave WS8. On the other hand, since the surface wave WS having a high imaging width is in smooth contact with the material to be inspected at the tip portion 3a, it immediately diffuses and propagates to the surface of the material to be inspected after being polymerized. Therefore, according to the ultrasonic probe of this embodiment, the four ultrasonic transmitter/receivers IA~
At the same time, the sound pressure from LD is almost concentrated in one point,
It becomes possible to propagate surface waves concentrically on the surface of the test material with the probe contact point as the center.

As mentioned above, in order to obtain high amplitude surface waves WSs by accurately phase interfering the ultrasonic waves from each ultrasonic wave transmitter/receiver IA to ID, each ultrasonic wave transmitter/receiver lA ~ID
In addition to being arranged with high precision as described above, each transmitter/receiver is placed at a more precise timing so that the transmission points of ultrasound from each ultrasonic transmitter/receiver IA to ID are sufficiently aligned. JA
-7D transmission is required. For this reason, it is effective to connect each ultrasonic transmitter/receiver IA to Jl)f6 in parallel to the ultrasonic injury device. However, when each ultrasonic transmitter/receiver 7A-JD is arranged in parallel, the amount of each increases at once, and there are cases where it is not possible to drive the ultrasonic transmitter/receiver IA-ID with sufficient power. In this case, it is necessary to prepare an ultrasonic transmitter/receiver for each transmitter/receiver JA-ID so that each ultrasonic receiver can operate at the same timing. Of course, when receiving ultrasonic waves, it is necessary to receive them with highly accurate timing. Note that if the ultrasound receivers are different for each transmitter/receiver at the time of wave reception, analog addition of the signals received by each transmitter/receiver is required. In addition, since the ultrasonic probe according to this embodiment has a plurality of ultrasonic transmitters/receivers, some of these transmitters/receivers are used for transmission, and the others are used for receiver 1. It is also possible to use the structure as a so-called two-part transmitter/receiver.

Next, using the ultrasonic probe according to the above-mentioned implementation,
An example of flaw detection for the entry surface uraguchi notch 181i and defects near the surface layer of a material to be inspected will be described with reference to FIGS. 6 to 8.

As shown in FIG. 6, since the ultrasonic probe P of this embodiment can transmit and receive surface waves in a circular pattern, the defect When the defect X is located almost perpendicular to the progression of the wave WS, it is always possible to easily detect the defect X with the probe P.

In addition, as shown in FIG. 7, if this probe P is used, ultrasonic waves can be transmitted and received at multiple points on the inspection target M to detect the presence or absence of defect X.
Instead of melting, the approximate position of the defect X can also be measured triangularly.

Furthermore, as shown in Fig. 8, the present probe P
By applying this method, it is also possible to perform high-accuracy one-dimensional measurement of the position of the defect X on a two-dimensional surface surface.

Note that the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with various modifications without changing the gist thereof.

For example, what is shown in FIG. 9 is an embodiment in which an ultrasonic absorbing material 4 is attached to the ridges or edges of the guide rod 2 and the tip seam 3. This makes it possible to reduce signals due to multiple reflections of surface waves reflected by the curved portion 2a when transmitting and receiving ultrasonic waves, and improves flaw detection performance. Furthermore, it is effective to lay the ultrasonic absorbing material 5 not only on the edge portion but also on the proximal end surface of the side rod 2 in order to prevent multiple echoes from going around.

Moreover, FIG. 7 shows another embodiment of the present invention.
A tip 6 having excellent wear resistance is further provided at the tip of the tip shoe 3 to prevent wear of the tip shoe 3.

In general, either a metal or a non-metallic material may be used for the chip f6, and the approximately converged surface wave propagates through the chip 6 onto the surface to be inspected. Note that it is effective to make the shape of the curved surface of h and f6 into a parabolic or hyperboloid shape so that the curved surface can make almost point contact with the test material (to avoid unnecessary ultrasonic reflections).

The ultrasonic probe of the present invention is characterized by the fact that the ultrasonic transmitter/receiver is uniformly attached to the circumferential surface of each polygonal column member of the guide rod 2, but the above-mentioned polygonal column member By removing the ultrasonic transmitter/receiver from a part of the surface, it is possible to transmit and receive surface waves in a specific direction range of the material to be inspected, which is effective when the flaw detection area is limited. .

〔Effect of the invention〕

According to the present invention, an ultrasonic probe that can radiate surface waves concentrically around the probe placement position and can perform flaw detection with high efficiency and in a short time on a material to be tested that has a wide flaw detection area is provided. can be provided.

Further, since the probe according to the present invention makes almost point-like contact with the test material on a curved surface, there is no need for a couplant for tuning, which is conventionally required in ultrasonic flaw detection. Moreover, this also produces effects such as the generation of various noises caused by the couplant due to ultrasonic waves and the need for work time associated with application and removal of the couplant.

The probe of the present invention keeps a record of the number of months it received ultrasonic waves each time the probe is moved to various locations on the specimen, and computer-processes the defect distribution status of the entire specimen. It can be effectively used when trying to obtain apertures using surface waves, etc., and can also be used as a probe when performing aperture synthesis using surface waves.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a perspective view and a sectional view showing the configuration of an embodiment of the present invention, FIG. 2 is a diagram for explaining ultrasonic convergence in the embodiment, and FIG. 3 is the same. Figures 4 and 5 are diagrams for explaining the arrangement conditions of the ultrasonic transmitter and receiver in the example, Figures 4 and 5 are diagrams for explaining the effects of the example, and Figures 6 to 8 are the same. FIG. 9 is a perspective view showing another embodiment of the present invention; FIG. 10 is a diagram showing another embodiment of the present invention. It is. 7 (JA-1D)...Ultrasonic transmitter/receiver, 2 guide rods,
2a・Curved surface shape part, 3 Tip part--13a...Tip part,
4, 5 Ultrasonic absorber, 6 ・Nup. Applicant's representative Patent attorney Takehiko Suzue Figure 1 a Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] Ultrasonic transmission and
Ultrasonic transmitters and receivers for surface liquid transmission and reception are respectively attached so that the wave reception direction is the same direction along the axial direction of the polygonal columnar member, and the ultrasonic wave transmission and reception directions of the polygonal columnar member are At the same time, a seam having a substantially polygonal pyramidal shape and a curved tip end that conforms to the shape of a polygonal prism is joined to the end part, and the joint surface of the polygonal prism member and the seam is connected to the seam from the polygonal prism member. An ultrasonic probe characterized by having a curved surface that converges sound waves almost at the tip of the probe. .