JP3058517B2 - High pressure hydrophone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure hydrophone, and more particularly to a high-pressure hydrophone for measuring a shock wave from a medical calculus breaking device.

[0002]

BACKGROUND OF THE INVENTION In recent years, with the development of medical equipment, calculus generated in, for example, a kidney has been crushed by a shock wave from outside the body, and is known as a calculus crushing device. Generally, the ultrasonic wave from the ultrasonic generator is focused on the stone (focus)
To generate a shock wave. The shock wave in such a case is said to be about 1000 atm or more when calculus is crushed. And measure the level of these shock waves,
A high pressure hydrophone has been proposed to clarify the causal relationship of calculus crushing.

[0003]

2. Description of the Related Art FIG. 8 is a diagram for explaining an outline of a proposed example of a high pressure resistant hydrophone. High pressure hydrophone
A piezoelectric polymer material 2 is housed in a cylindrical container 1. The cylindrical container 1 is formed, for example, by cutting the inside from the other end surface side of the metal rod, and the one end surface 3 is used as a sound pressure detection surface. The polymer piezoelectric material is made of, for example, PVDF (polyvinylidene fluoride), and excitation electrodes (not shown) are formed on both main surfaces. Then, the main surface of the polymer piezoelectric material 2 is arranged on one end surface 3 of the cylindrical container 1 so as to face the other end, and a metal plate 5 pressed by a conductive spring 4 is provided on the other main surface. That is, the piezoelectric polymer material 2 is pressed against the one end surface 3 of the metal container by the elasticity of the spring 4 and held, and at the same time, the electrodes are led out. An insulating material 6 is provided on the inner periphery of the metal container, and the other end surface is closed by a lid (not shown). However, the spring 4 is electrically led to the outside by a terminal provided on the lid (not shown). In such a device, since the polymer piezoelectric material 2 is used as the piezoelectric material, the piezoelectric material is less likely to be damaged by a shock wave than solid materials such as quartz and PZT (lead zirconate titanate). Further, since no bonding agent is used in the electrode lead-out portion, there is an effect that there is no destruction at that portion.

[0004]

However, in the above-mentioned structure, the polymer piezoelectric material 2 is held by the pressure bonding method,
There has been a problem that the reception level changes every time a shock wave arrives, and stable measurement cannot be performed. That is, the electrical connection between the excitation electrodes provided on both main surfaces of the polymer piezoelectric material 2 and the one end surface 3 of the cylindrical container 2 and the metal plate 5 that sandwiches the excitation electrodes,
Due to the elastic connection structure, the connection strength is not stabilized by the shock wave, and as a result, there is a problem that the reception level changes. The sound pressure detection surface on one end surface 3 is formed by cutting the inside from the other end surface of the metal bar. Therefore, it is difficult to make the thickness and flatness uniform, and there is a problem that unevenness or the like is caused in the adhesion to the polymer piezoelectric material 2 and the reception level is changed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-withstand-pressure hydrophone that stabilizes a reception level.

[0006]

According to the present invention, an integrated polymer piezoelectric material extending from an excitation unit and extending from an excitation unit is applied as a piezoelectric material, and the front surface of the excitation unit is brought into close contact with one end side of the cylindrical container to thereby excite the excitation. A basic solution is that a damper is provided on the rear surface of the portion, and the drawer portion is bent and led out from the rear end side of the damper. Hereinafter, an embodiment of the present invention will be described.

[0007]

FIG. 1 is a sectional view of a high pressure-resistant hydrophone for explaining an embodiment based on the solution of the present invention. The high pressure resistant hydrophone generally includes a piezoelectric polymer material 10, a damper 11, a cylindrical container 12, and a relay 13.
As shown in FIG. 2 (plan view), the polymer piezoelectric material 10 is formed integrally with extending portions 15 (ab) extending from both ends of the excitation portion 14. The excitation section 14 has an excitation electrode 16 (ab) in a substantially circular shape at the center of both main surfaces.
The width of the extraction portion 15 (ab) is smaller than the diameter of the excitation portion 14, and the extraction electrode 17 (ab) extending from the excitation electrode 16.
Having. The damper 11 is made of a rubber-like elastic material, and is provided on the rear surface of the polymer piezoelectric material 10. That is, the excitation section 14 of the polymer piezoelectric material 10 is used as a main surface, and the extraction section 15 (a
b) is bent and adhered to the side surface, and the leading end of the drawer 15 is further extended to the rear end side of the damper 11. The integrated polymer piezoelectric material 10 and damper 11 are referred to as a piezoelectric unit 18. The cylindrical container 12 includes a container main body 19 and a connector 20.
And an extension 21. These are connected components 20
Made of stainless steel except for (resin). Container body 19
Has a small hole 22 (approximately 3.5 mm) on one end face side and an open face on the other end face side. The small holes 22 are closed by a flat protection plate 23. In the container body 19, the front surface (excitation section 14) of the piezoelectric unit 18 is brought into contact with the protection plate 23 to accommodate the protection plate 23, and a filler 24 is embedded between the piezoelectric body 18 and the container body 19. In this example, the protection plate 23
Is previously bonded to the front surface of the piezoelectric unit 18 (the excitation unit 14). Then, in a state where the adhesive (filler) is filled in the container main body 19, the piezoelectric unit 18 is inserted from the opening side, and the hole on one end side is closed by the protective plate 23 and accommodated. The connector 20 is made of a convex resin material having a hole in the center. Then, the convex tip side is inserted into the opening surface of the container body 19. The extension portion 21 has openings at both ends, one end is connected to the connector 20, and the other end is sealed with a resin lid. Incidentally, the overall length of the cylindrical container 12 is 50 mm, and the diameter is 5 mm. The relay 13 has a substantially E-shaped cross section, and a conductor such as a metal tape is formed in both grooves (see FIG. 4). At one end, the lead-out portion 15 (lead-out electrode 17) of the polymer piezoelectric material 10 is connected by a conductive adhesive or the like. The other end is connected to each line of the coaxial cable. The filler 24 is buried in the gap between the relay 13 and the extension 21 as described above. The coaxial cable is led out of the cover 25 through a hole.

With such a configuration, as compared with the conventional crimping method of the prior art, the electrical lead-out from the excitation section 14 (excitation electrode 16) is reliably performed by the extraction section 15 (extraction electrode 17). Also, the reception level does not fluctuate due to the change in the electrical connection strength due to the shock wave. And drawer 1
5 extends to the rear end side of the damper 11 and is connected to the relay 13, that is, is connected at a position away from the one end side (sound pressure detection surface), so that the shock wave does not act directly. , To prevent destruction at the connection. In this embodiment, a protective plate 23 is provided on the front surface of the piezoelectric polymer material 10 to close the small hole 22 of the container body 19. Then, the shock wave is received with the protection plate 23 interposed. Therefore, it is easier to make the thickness and flatness of the protection plate 23 constant than to provide a sound pressure detection surface by providing a hole in a metal bar in the conventional example,
The reception level can be made the same by improving the degree of adhesion to the polymer piezoelectric material 10. Then, the container body 19 and the piezoelectric unit 1
Since the filling material 24 is buried between the polymer piezoelectric material 8, the shock wave is absorbed, the breakage of the draw-out portion 15 of the polymer piezoelectric material 10 is prevented, and a waterproof effect is also achieved.

[0009]

[Others] In the above embodiment, one end surface of the container body 19 is closed by the protection plate 23 provided on the front surface of the piezoelectric unit 18, but the protection plate 23 may be provided in advance. For example, as shown in FIG. 5, the protection plate 23 is fitted and caulked at a step provided at the tip of the container body 19, and after filling a filler 24 such as silicon in the gap, the piezoelectric unit 18 is housed. You may do so. And the piezoelectric unit 18
Is fixed by the filler 24, but the present invention is not limited to this, and other fixing means using, for example, screws or the like may be used. In addition, the cylindrical container 12 is provided with a container main body 19 and an extension 21 so as to make it easy to fix the piezoelectric unit 18 to one end surface side.
And connected by the connecting member 20, but can be configured basically without using the connecting member 20. Also,
Although the drawer and the coaxial cable line are connected using the relay 13, the drawer and the coaxial cable may be directly connected without using the relay 13. For example, as shown in FIG. 6, the lead-out portion 15 of the piezoelectric unit 18 and each line of the coaxial cable 27 are directly connected to the rear end of the damper 11 by a conductive adhesive or the like (not shown). Then, a cylindrical holder 28 (see FIG. 7) may be fitted to the rear part of the damper 11, and the rear end of the damper 11 may be pressed by the pressing spring 29. Note that reference numeral 30 in the drawing denotes a rear pressing member, and reference numeral 31 denotes a waterproof fixing member such as silicon. In this case, an adhesive may or may not be interposed between the polymer piezoelectric material 10, the damper 11, and one end surface of the cylindrical container as necessary. Further, the width of the lead-out portion 15 in the polymer piezoelectric material 10 is smaller than the diameter of the excitation portion 14, but may be equal to or larger than the diameter of the excitation portion 14 in order to increase the strength of the bent portion. Further, although the cylindrical container 12 is closed by the protective plate 23, it may be basically an integrally molded one as shown in the conventional example. The present invention enables various modifications as described above.
4, the front surface of the excitation unit 14 is brought into contact with one end surface (sound pressure detection surface) of the cylindrical container 12 by applying the polymer piezoelectric material 10 extended from the extraction unit 15 to the rear surface of the excitation unit 14. Damper 11
And extending the drawer 15 from the rear end side of the damper 11 to eliminate the adverse effect of the shock wave as a basic technical idea. The structure based on such an idea is as follows. It belongs to the technical scope of the present invention.

[0010]

According to the present invention, an integral polymer piezoelectric material extending from the exciting section and extending from the exciting section is applied as the piezoelectric material, and the front surface of the exciting section is brought into close contact with one end side of the cylindrical container. Since a damper is provided on the rear surface of the excitation unit and the lead-out unit is bent and led out from the rear end of the damper, a high-withstand-pressure hydrophone that stabilizes the reception level can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a high pressure-resistant hydrophone for explaining an embodiment of the present invention.

FIG. 2 is a plan view of a polymer piezoelectric material applied to one embodiment of the present invention.

FIG. 3 is a diagram of a piezoelectric unit in one embodiment of the present invention.

FIG. 4 is a view of a relay device in one embodiment of the present invention.

FIG. 5 is a view of a container body illustrating another embodiment of the present invention.

FIG. 6 is a sectional view of a high pressure-resistant hydrophone for explaining another embodiment of the present invention.

FIG. 7 is a view of a cylindrical holder in another embodiment of the present invention.

FIG. 8 is a partial sectional view of a high-voltage hydrophone for explaining a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 High molecular piezoelectric material, 11 Damper, 12 Cylindrical container, 13 Relay, 14 Exciter, 15 Leader, 16
Excitation electrode, 17 extraction electrode, 18 piezoelectric unit, 19
Container main body, 20 Connecting tool, 21 Extension, 22 Small hole, 23 Protective plate, 24 Filler, 25 Lid, 26
Conductor, 27 coaxial cable.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-7994 (JP, A) Japanese Utility Model 1983-33008 (JP, U) Japanese Utility Model 1988-179,000 (JP, U) Field (Int.Cl. ⁷ , DB name) H04R 1/44 330 A61B 17/22 330 G01N 29/04 H04R 17/00 330

Claims (1)

(57) [Claims] 1. A high pressure-resistant hydrophone in which a main surface of a piezoelectric material is opposed to one end surface of a cylindrical container and a sound pressure arriving at said one end surface is detected. apply the extending therefrom polymer piezoelectric material, a damper disposed on the rear surface of the closing surface to become Rutotomoni the excitation portion is brought into close contact with one end of the tubular container provided with a protective plate in front of the excitation portion, the pull-out A high pressure-resistant hydrophone characterized in that a part is bent out of the rear end of the damper.