JPS6338157A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To shorten an inspection time greatly by arranging plural curved- surface vibrators which diffuse ultrasonic waves at specific angles in the tube direction of a body to be tested. CONSTITUTION:The size and radius of curvature of the curved-surface vibrators and the arrangement angles A of the vibrators are so selected that spreads of ultrasonic wave beams generated by the vibrators 1a and 1c overlap with ultrasonic wave beams generated by adjacent curved-surface vibrators 1b and 1d. Then, many curved-surface vibrators enough for the width of an ultrasonic wave beam on one ultrasonic probe to secure an area of more than a specific angle in the tube periphery direction of the body 5 to be tested are provided to widen the inspection range, thereby shortening the inspection time greatly.

Description

[Detailed Description of the Invention] [Field of Commercial Application] This invention relates to an ultrasonic probe that detects defects occurring in existing piping by transmitting and receiving ultrasonic waves in the axial direction of the pipe material. It is related to.

[Conventional technology]

Figure 4 shows, for example, the ultrasonic flaw detection method (1971 Nikkan Kogyo-1).
Fig. 4(a) is a front sectional view of an angle probe;
FIG. 4(b) is a cross-sectional view of the angle probe.

In the figure, (1) is a flat plate-shaped transducer for transmitting and receiving ultrasonic waves, and (2) is the fixing of the transducer (1).

A plastic wedge for mode converting the longitudinal ultrasonic waves generated from the transducer (11) into transverse ultrasonic waves.

(3) is a sound absorbing material that absorbs unnecessary ultrasonic waves, (4) is a probe case, (5) is a test piece such as a pipe material, and (6) is a contact medium to increase the propagation efficiency of ultrasonic waves. is longitudinal ultrasound.

The mouth is transverse ultrasound.

The conventional ultrasonic probe is constructed as described above, and the longitudinal ultrasonic wave A generated from the transducer (11) propagates within the wedge (2) and connects the above-mentioned mat (2) and the test specimen (5). ) at the interface with the specimen (5) where the transverse wave is converted into an ultrasonic wave according to Snell's law.
The longitudinal wave ultrasonic wave A propagates forward, is reflected by a defect or a discontinuous part in the test object (5), and is again received by the transducer fl) on the reverse path.

At this time, with conventional ultrasound probes, the probe case (4)
Since only one transducer (11) is provided in the tube, the ultrasonic beam width in the direction corresponding to the circumferential direction of the test specimen (5) is narrow; When inspecting the entire circumference, the number of scans of the ultrasonic probe becomes extremely large, making it impossible to reduce the inspection time.

[Problem that the invention seeks to solve]

As mentioned above, in the case of an ultrasonic probe equipped with only one transducer (1), the ultrasonic beam width corresponding to the circumferential direction of the test specimen (5) is narrow, resulting in a long inspection time. There was a point.

In addition, in order to solve the above problem, even if a plurality of conventional ultrasonic probes are arranged in the circumferential direction of the test specimen (5), the transducer +11 of the conventional ultrasonic probe is a flat plate. Due to its shape, the ultrasound beam width is narrow.

There is a problem in that there is a region where the ultrasound beam widths do not overlap between the ultrasound probes, and even in the above case, the calibration time cannot be expected to be reduced much.

This invention was made in order to solve the above problems, and it is possible to ensure that the ultrasonic beam widths of multiple transducers overlap, so that the ultrasonic beam width of one ultrasonic probe is An object of the present invention is to obtain an ultrasonic probe that can secure an area fc of 120° or more in the tube circumferential direction.

[Failure to solve the problem]

The ultrasonic probe according to the present invention has a plurality of curved transducers that diffuse ultrasonic waves arranged at a predetermined angle in the circumferential direction of a test specimen.

[Effect]

In this invention, the dimensions and radius of curvature of the transducer are adjusted so that the spread of the ultrasonic beam generated from one curved transducer completely overlaps the ultrasonic beam generated from two adjacent curved transducers. Select the placement angle, and 1
Since the ultrasonic probe is equipped with a number of curved transducers that can secure an area where the total ultrasonic beam width of the ultrasonic probe is 120 degrees or more in the circumferential direction of the test specimen, inspection time can be significantly shortened. Become.

[Embodiment] Fig. 1 is a sectional view of an ultrasonic probe showing an embodiment of the present invention, and Fig. 1(a) is a front M view of an angle probe. b) is a cross-sectional view of the angle probe.

In the figure, (1a) to (1d) are curved transducers having a curvature that allows ultrasonic waves to diffuse; (2) is a plastic wedge having a radius of curvature equivalent to that of the curved transducer; (3) ) is a sound-absorbing material that absorbs unnecessary ultrasonic waves.

(4) is the probe case, (5) is the specimen such as pipe material, (6
) is the contact medium, (7) is the shoe that maintains the gap between the wedge (2) and the test specimen (5), A is the longitudinal wave ultrasonic wave, and one mouth is the transverse wave ultrasonic wave.

Person is the angle at which the curved surface vibrators (1a) to (1b) are arranged with respect to each other.

FIG. 2 is a diagram showing the width of an ultrasonic beam formed by the ultrasonic probe according to the present invention.

In the figure, C is the ultrasonic beam width formed by the curved transducer (1a), 2 is the ultrasonic beam width formed by the curved transducer (1b), and E is the ultrasonic beam width formed by the curved transducer (1C). The sound wave beam width is the ultrasound beam width formed by the curved surface transducer (1d), and H is the amplitude of the ultrasound signal.

θ is the circumferential angle of the test specimen (5).

FIG. 3 is a diagram showing the correlation between the dimensions of the bicurved vibrator, the radius of curvature, and the arrangement angle with respect to the outer diameter of the test piece.

In the figure, = (1a), (1b) is the curved surface f5i
Doko, (2) is a wedge.

(5) is the arrangement angle of the curved surface vibrator (1a) for the two test subjects;
L is the dimension of the curved surface vibrator (1a), I! 1 is the test specimen (5)
The ultrasonic beam width from the center of the curved transducer (1a) on the surface, 12 is the ultrasonic beam width from the center of the curved transducer (1a) on the inner surface of the specimen (5), and IL is the ultrasonic beam width from the center of the curved transducer (1a) on the inner surface of the specimen (5). The radius of curvature, θ1 is the angle of the ultrasonic wave emitted from the curved transducer (1a), θ2 is the angle between the beam width 11 on the surface of the specimen (5) and the normal QO, and θ5 is the angle of the ultrasonic wave to the specimen (5) The incident angle of ultrasonic waves, θ4 is the test specimen (5)
This is the refraction angle of the ultrasonic wave inside.

Here, it is desirable that the dimensions of the two-curved vibrator (1a) be 20y+i or less in order to prevent a decrease in defect detection ability. In addition, the ultrasonic coverage range of one block of the ultrasonic probe is desirably 180° or less in order to facilitate delamination between the ultrasonic probe and the test specimen (5), which is calculated by dividing 360° by an integer. In terms of data processing, it is desirable that the angle is straight, and in most cases 120° is a standard.

Furthermore, the radius of curvature hole of the one-curved camera element (1a) has a difference between the minimum value and the maximum value of the distance that the ultrasonic wave propagates within the wedge (2).
By setting the wavelength within ) to about 1/4 to 1 A, it is possible to prevent the ultrasonic waves from rapidly diffusing and reducing the defect detection ability.

Under the above preconditions, the dimensions of one curved surface vibrator (1a) are 2
Curvature radius of curved surface vibrator (1a) 2 curved surface vibrator (1a)
The placement angle of key figures can be found by the following relationship.

w = t/■θ8 ・・・・・・・・・
・・・・・・(11/1”dnθ1×(R+Δl)
・・・・・・・・・・・・・・・(2)-j
/j ・・・・・・・・・・・・・・・
・(3) θr bite (1) θ5=o1+o2 ・・・・・・・・・
・・・・・・(4)! ! 2 #11 + to (θ
4-02)×W ・・・・・・・・・・・・・・・(6
)-11!2 people = 2 X * (-) ・・・・・・・・・
・・・・・・(7) D/2-t n≧ヱ ・・・・・・・・・・・・・・・
(8) Person However, as an assumption condition, λ L2 λ −<R2−(−)<− ・・・・・・・・・・・・・・・
...(9) In equations (1) to (9), t: thickness Δl of the test piece! : Wedge length vl: Longitudinal wave sound velocity in the wedge v2: Transverse wave sound speed in the test piece n: Number of curved surface oscillators ψ: Coverage range (per probe 1 block) θ11: Shear wave refraction angle in the test piece 2 Outer diameter dimension W of the test piece: 0.5 skip distance λ in the test piece: Represents the wavelength in the wedge.

In this example, when the outer diameter of the test specimen (5) is 60.5 mm, the dimensions of the curved surface vibrators (1a) to (1d) are set to 18 m, and the curvature of the curved surface vibrators (1a) to (1d) is Radius hole 1
By selecting the 50" kiln and the arrangement angle of 30", the test specimen (5) was created using four curved surface sensors (1a) to (1d).
This made it possible to transmit and receive ultrasonic waves over approximately 120 degrees of tube circumference.

That is, in the ultrasonic probe configured as described above, curved transducers (1a) to (1) that transmit and receive ultrasonic waves are used.
The longitudinal ultrasonic wave A generated from d) propagates while diffusing inside the wedge (2), and further passes through the test specimen (5) according to Snell's law.
According to the outer diameter curvature of the transverse wave, the ultrasonic wave is further diffused and propagated in the tube circumferential direction as a transverse wave aperture.

Therefore, the dimensions of the two curved surface vibrators (1a) to (1d) and the curved surface vibrator (1a) are determined according to the outer diameter dimension of the test specimen (5).
) to (1d) and the curved surface vibrator (1a).
By determining the key placement angles of ~(1d) using equations (7)~(9), fewer curved surface oscillators (1a)~(1) can be obtained.
With the number d), it becomes possible to transmit and receive ultrasonic waves over a wide range in the circumferential direction of the test specimen (5). Also, of course.

It is also easily possible to completely overlap the ultrasonic beam widths between the curved surface transducers (1a) to (1d) with amplitudes within -3 dB.

In addition, a curved vibrator (1a) made of a plastic wedge (2)
The curved surface vibrator (1a)
) to (1d), and has a radius of curvature equivalent to that of (1d).

The surface facing the test body (5) has a radius of curvature equal to the outer diameter of the test body (5) plus a predetermined gap. In other words, when considering the outer diameter tolerance, roundness, etc. of the test piece (5), the contact area between the wedge (2) and the test piece (5) becomes large. A shoe (7) is used to provide a predetermined gap between the housing and the outer surface of the housing (5), and a contact medium is supplied to the gap to prevent poor acoustic coupling.

〔Effect of the invention〕

As explained above, the present invention is capable of transmitting energy in the circumferential direction of the test specimen by arranging a plurality of ultrasonic diffusion type curved surface transducers at a predetermined angle on the wedges corresponding to the circumferential direction of the test specimen. Since the inspection range can be widened, the inspection time can be significantly shortened.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the ultrasonic probe according to the present invention.
FIG. 1(a) is a front cross-sectional view, and FIG. 1(b) is a cross-sectional view. Figure M2 is a diagram showing the ultrasonic beam width of the ultrasound probe according to the present invention, Figure 3 is a diagram showing the correlation between the dimensions of the curved transducer, the radius of curvature, and the arrangement angle, and Figure 4 is a diagram showing the relationship between the dimensions of the curved transducer, the radius of curvature, and the arrangement angle. 4(-) is a front sectional view, and FIG. 4<b) is a cross-sectional view of the feeler. In the figure, (1) is a flat plate vibrator, (1a) to (1
d) is a curved vibrator, (2) is a sound absorber, (3) is a sound absorbing material, (4
) is the probe case, (5) is the specimen, A is the longitudinal ultrasound 2
The opening is the transverse wave ultrasound, and (c) ~ 2) is the ultrasonic beam 1-2 is the arrangement angle of the curved transducer. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] An angle probe that transmits and receives ultrasonic waves in the axial direction of a tube material includes: a plurality of ultrasonic diffusion type curved transducers arranged at a predetermined arrangement angle in the circumferential direction of the tube material; and the curved transducer and the tube material. The surface on which the curved surface vibrator comes into contact has a radius of curvature equivalent to the radius of curvature of the curved surface vibrator, and the surface facing the outer surface of the tube has a radius of curvature equal to the outer diameter of the tube material. An ultrasonic probe comprising a plastic wedge having a corresponding curvature.