JPH01193643A - ultrasonic probe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic probe having a configuration in which a large number of piezoelectric elements are arranged.

[Conventional technology]

Ultrasonic flaw detection devices can detect defects inside a material to be inspected without destroying it, and are used in many fields. The presence or absence of internal defects in a material to be inspected is often checked on a predetermined area of the material to be inspected. In this case, flaw detection is performed by scanning the predetermined area on the surface of the material with an ultrasonic probe. Implemented. There are various types of ultrasonic probes, but in order to perform flaw detection by scanning the test material, an array-type ultrasonic probe consisting of a large number of piezoelectric elements arranged in rows is used. Children are preferred. Hereinafter, an array-type ultrasonic probe will be explained with reference to the drawings.

Figures 3(a) and 3(b) are diagrams showing conventional array-type ultrasonic probes. Figure 3(a) is a side view, and Figure 3(b) is the same as that of Figure 3(a). ep+~p which is a front view seen from arrow mb
1 is a piezoelectric element arranged in a row, 1 is each piezoelectric element p, ~
A backing material that supports pH, 2 is each piezoelectric element p+-1
This is a lens commonly provided on the ultrasonic transmitting and receiving sides of 's.

When a pulse voltage is applied to the piezoelectric element pI, the piezoelectric element pI
Ultrasonic waves are emitted from the This ultrasonic beam is shown in Figure 3 (
Indicated by 3 in a). The ultrasonic beam 3 is focused by a lens 2 to a focal point F. Such an ultrasonic beam 3 is incident on a material to be inspected (not shown), and its reflected wave travels back along the same path and is incident on a piezoelectric element p.

Due to the incidence of this reflected wave, a voltage proportional to the reflected wave is generated in the piezoelectric element p. The other piezoelectric elements p2 to p7 also have exactly the same function.

In the above array-type ultrasonic probe, when piezoelectric elements p1 to p are selected, and a pulse voltage is applied to each of these piezoelectric elements with a predetermined delay time, the maximum amplitude of the ultrasonic waves emitted from them all becomes A place to gather will appear. This point can be adjusted by selecting the delay time, and the figure shows an example in which it is adjusted to match the focal point of the lens 2. In this way, when a plurality of piezoelectric elements are excited by giving a delay time, the ultrasonic waves from those piezoelectric elements are generated in the arrangement direction of the piezoelectric elements as shown in Fig. 3(b).
As shown by the broken line, this will apparently lead to a lot of planning. Next, the piezoelectric elements p2 to p7 are selected by shifting the piezoelectric element selection by one, and each piezoelectric element p! is selected in the same delay manner. When a pulse voltage is applied to ~p, the ultrasonic beam emitted from them (indicated by a dashed line -) is apparently focused on point Fz.

In this way, if the selection of piezoelectric elements is shifted one by one and each piezoelectric element is excited with the same delay mode, the apparent focal point of the ultrasound beam will move in the direction shown by the arrow X in Fig. 3(b). will transition. Thereby, the object to be inspected can be scanned by the ultrasonic beam. Since this scanning can be performed electronically, there is a great advantage that flaw detection of the test material can be carried out extremely quickly.

[Problem to be solved by the invention]

In the above-mentioned array type ultrasonic probe, a lens 2 that focuses ultrasonic waves is essential for highly accurate flaw detection. However, the use of this lens 2 not only causes the problem of increasing the size of the ultrasound probe, but also causes the following problems.

That is, the ultrasonic waves generated by each piezoelectric element are attenuated by passing through the lens 2, and are also attenuated by reflection from the two boundary surfaces of the lens 2, on the piezoelectric element side and the outside side. Furthermore, since there is reflection at the interface between the two lenses 20, three reflected waves are generated in addition to the reflection from the surface of the material to be inspected, and when repeated flaw detection is performed, these reflected waves and the defect wave overlap, causing defects to be overlooked. There was also a fear.

An object of the present invention is to provide an ultrasonic probe that solves the above-mentioned problems and can omit the use of a lens.

(Means for Solving the Problems) In order to achieve the above object, the present invention arranges a large number of piezoelectric elements and sequentially selectively excites a predetermined number of these piezoelectric elements so as to cross the surface of a material to be inspected. In an ultrasonic probe that performs sound wave scanning, a flexible sheet member on which each piezoelectric element is arranged is curved at a predetermined curvature along the arrangement direction of each piezoelectric element to form an ultrasonic probe. It is characterized by having been configured.

[For production]

When a pulse voltage is applied to the piezoelectric element, ultrasonic waves are emitted from the piezoelectric element. Because the sheet material that embeds the ultrasonic waves is curved with a predetermined curvature, the ultrasonic waves are emitted simultaneously from multiple piezoelectric elements along the curvature, and the maximum amplitude is all concentrated at a predetermined position, causing the lens to You can get the same effect as if you used it.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a side view of an ultrasound probe according to an embodiment of the present invention. In the figure, 1 is a backing material, and 5 is a sheet member in which a piezoelectric element is embedded. A large number of piezoelectric elements embedded in the sheet member 5 are arranged in rows in a direction perpendicular to the plane of the paper. The sheet member 5 is curved with a predetermined curvature and fixed to the backing member 1. Such a sheet member 5 will be explained with reference to FIG. 2.

FIG. 2 is a perspective view of the sheet member, where 6 is a flexible plate made of, for example, an epoxy synthetic resin material, and p is a piezoelectric material embedded in the plate 6 arranged vertically and horizontally at predetermined intervals. It is element. In this figure, a part of the plate 6 is shown, and a part is shown as a cross section. If the plate 6 is cut along two points tM vAc among the piezoelectric elements p buried in the plate 6, the sheet member 5 consisting of the piezoelectric cables p buried in the rows of the plate 6 can be cut. Obtainable. In this sheet member 5, each piezoelectric element p is insulated from each other by a plate 6. Since the plate body 6 is made of a flexible material, the sheet member 5 can be curved at an arbitrary rate, and this curved sheet member 5 is bonded to the backing material 1. .

As described above, in this example, the flexible sheet member in which a large number of piezoelectric elements are arranged and buried in rows is curved at a predetermined curvature and fixed to the backing material, so that the piezoelectric elements that have sprouted in the circumferential direction can be The maximum amplitudes of the simultaneously emitted ultrasonic waves all converge at a predetermined position τ, and the same effect as using a lens can be obtained, so the use of a lens is unnecessary.
becomes.

Therefore, the ultrasonic probe can be made small and the attenuation of ultrasonic waves can be reduced.
Furthermore, since there is no reflection on the lens, there is no overlap with the signal of the defective part, and it is possible to prevent the defective part from being overlooked.

In the explanation of the above embodiment, an example was explained in which one row of cables is used for pressure, but it is not limited to - rows (and an appropriate number of rows of two or more rows can be used. In this case, each row The piezoelectric elements located at the same position will be excited at the same time, and the curvature of the sheet member will be changed accordingly.

〔Effect of the invention〕

As described above, in the present invention, a flexible sheet member in which piezoelectric elements are arrayed and embedded is used by being curved at a predetermined curvature. Therefore, the lens can be removed, and thereby, the ultrasonic probe In addition to being able to make the child smaller,
Attenuation of ultrasonic waves can be reduced, and defects can also be prevented from being overlooked.

[Brief explanation of the drawing]

FIG. 1 is a side view of an ultrasound probe according to an embodiment of the present invention;
Figure 2 is a perspective view showing the sheet member, Figures 3 (a) and (b).
) are a side view and a front view of a conventional ultrasound probe. 1... Backing material, 5...
...Sheet member, 6...Plate body, p...
・・・・・・Piezoelectric element, C・・・・・・Cutting line. Agent: Kenji Takeshi, Patent Attorney (1 other person) Figure 1 Figure 2 Figure 3 "':f"

Claims (1)

[Claims] In an ultrasonic probe that ultrasonic scans the surface of a specimen by arranging a large number of piezoelectric elements and sequentially selectively exciting a predetermined number of these piezoelectric elements, a flexible sheet in which each piezoelectric element is embedded and arranged is used. An ultrasonic probe characterized in that the member is curved at a predetermined curvature along the arrangement direction of the piezoelectric elements.