KR102248811B1 - Apparatus and system for generating acoustic wave including electrode - Google Patents

Abstract

A sound wave generating device according to an embodiment includes a piezoelectric element; A circular first electrode coupled to the central portion of the piezoelectric element; And an annular second electrode spaced from the first electrode in a radial direction and coupled to an outer portion of the piezoelectric element.

Description

A sound wave generating device and system including an electrode TECHNICAL FIELD [APPARATUS AND SYSTEM FOR GENERATING ACOUSTIC WAVE INCLUDING ELECTRODE]

Hereinafter, embodiments relate to a sound wave generating apparatus and system.

Devices that generate sound waves using piezoelectric elements have been developed. Such an apparatus is configured to apply a voltage to the piezoelectric element, and a sound wave may be generated from the piezoelectric element by the applied voltage. The magnitude and resonance frequency of the sound wave generated from the piezoelectric element may be controlled by the size, physical properties, and structure of the transducer of the piezoelectric element. In addition, the beam pattern characteristic of sound waves generated by such a device is important, and a low frequency active sonobuoy, one of the underwater acoustic transducers, is required to have a high directivity beam pattern characteristic. However, it is necessary to consider the spatial characteristics in which the device is installed.

US Patent Publication No. 6,400,645 (registered in 2002.06.04.)

An object according to an embodiment is to provide a sound wave generating apparatus and system that prevents the occurrence of a grating lobe, which is an unintended beam pattern phenomenon, has spatial efficiency, and has high directivity.

The sound wave generation system according to an embodiment relates to a sound wave generation system for a sono buoy used underwater to prevent the generation of a grating lobe and improve the directivity of a beam pattern, wherein the sound wave generation system includes a plurality of sound waves. Generating devices, the plurality of sound wave generating devices comprising: a piezoelectric element; A circular first electrode coupled to the center of the piezoelectric element; An annular second electrode spaced from the first electrode in a radial direction and coupled to an outer portion of the piezoelectric element; And a waterproof member surrounding the piezoelectric element, the first electrode, and the second electrode, respectively, wherein the first electrode and the second electrode are disposed concentrically and point-symmetrically with respect to the center of the piezoelectric element, The plurality of sound wave generating devices may be arranged only in a row so as to have a radial direction in the same axial direction.

The radiated sound pressure of the sound wave generating device may be determined based on a first radiated sound pressure due to a region covering the first electrode and a second radiated sound pressure due to a region covering the second electrode.

The first radiation sound pressure may be determined by a radius of the first electrode, and the second radiation sound pressure may be determined by an outer radius and an inner radius of the second electrode.

The radiated sound pressure of the sound wave generating device may be determined by the following equation.

<Equation>

,

,

이고, (here,

,

,

ego,

는 제2전극의 외측 반지름에 의해 결정되는 방사 음압,

는 제2전극의 내측 반지름에 의해 결정되는 방사 음압,

는 제1전극의 반지름에 의해 결정되는 방사 음압을 나타내고,

는 제2전극의 외측 반지름에 의해 결정되는 제1지향 지수,

는 제2전극의 내측 반지름에 의해 결정되는 제2지향 지수,

는 제1전극의 반지름에 의해 결정되는 제3지향 지수를 나타내고,

는 음파 발생 장치의 지향축에 대해 이루는 각도)

Is the radiated sound pressure determined by the outer radius of the second electrode,

Is the radiation sound pressure determined by the inner radius of the second electrode,

Represents the radiated sound pressure determined by the radius of the first electrode,

Is a first orientation index determined by the outer radius of the second electrode,

Is a second orientation index determined by the inner radius of the second electrode,

Denotes a third orientation index determined by the radius of the first electrode,

Is the angle made with respect to the directional axis of the sound wave generator)

delete

The sound wave generating device may further include at least one annular third electrode spaced from the second electrode in a radial direction and coupled to an outer portion of the piezoelectric element.

The first electrode and the second electrode may be coupled to any one of a front and a rear side of the piezoelectric element, and the sound wave generator may further include an additional electrode coupled to the other one of a front and a rear side of the piezoelectric element. .

delete

The sound wave generating apparatus and system according to an exemplary embodiment prevents the generation of grating lobes, has spatial efficiency, and has high directivity.

Effects of the sound wave generating apparatus and system according to an exemplary embodiment are not limited to those mentioned above, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a perspective view of a sound wave generating system according to an embodiment.
2 is a cross-sectional view of a sound wave generator according to an exemplary embodiment.
3 is a view for explaining the radiated sound pressure of the sound wave generating device according to an embodiment.
4 is a cross-sectional view of a sound wave generator according to another embodiment.

Hereinafter, embodiments will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible, even if they are indicated on different drawings. In addition, in describing the embodiment, if it is determined that a detailed description of a related known configuration or function interferes with the understanding of the embodiment, the detailed description thereof will be omitted.

In addition, in describing the constituent elements of the embodiment, terms such as first, second, A, B, (a) and (b) may be used. These terms are for distinguishing the constituent element from other constituent elements, and the nature, order, or order of the constituent element is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected or connected to that other component, but another component between each component It should be understood that may be “connected”, “coupled” or “connected”.

Components included in one embodiment and components including common functions will be described using the same name in other embodiments. Unless otherwise stated, the description of one embodiment may be applied to other embodiments, and a detailed description will be omitted in the overlapping range.

1 is a perspective view of a sound wave generating system according to an exemplary embodiment, and FIG. 2 is a cross-sectional view of a sound wave generating apparatus according to an exemplary embodiment.

Referring to FIG. 1, a sound wave generating system 1 according to an exemplary embodiment may include a plurality of sound wave generating devices 10 configured to generate sound waves. The plurality of sound wave generating devices 10 may be arranged in a row so that each axis X faces the same sound wave generating direction. Here, the direction in which the sound wave is generated may be understood as the direction in which the sound wave is emitted. This sound wave generating system 1 can be used for a sonobuoy.

Referring to FIG. 2, the sound wave generator 10 according to an exemplary embodiment may have a structure having a high directivity while occupying a relatively small space. In other words, the sound wave generating device 10 may have a small radiation area. Here, the "radiation area" refers to the area of a source where sound waves are generated. Accordingly, the reduction in the radiation area of the sound wave generating device 10 means that the size of the entire system constituting the sound wave generating device 10 is reduced.

The sound wave generating device 10 may have an annular electrode pattern structure. For example, the sound wave generating device 10 may include a piezoelectric element 110, a front electrode unit 120, a rear electrode unit 130, and a control unit 140.

The piezoelectric element 110 is configured to generate vibration while expanding or contracting when a specific stimulus is applied. The piezoelectric element 110 may have a cylindrical shape, but is not limited thereto. The piezoelectric element 110 may include a ceramic material.

The front electrode part 120 may be located in front of the piezoelectric element 110. The front electrode unit 120 may include a first electrode 121 and a second electrode 122 respectively coupled to a front end of the piezoelectric element 110.

The first electrode 121 may have a circular plate shape. The first electrode 121 may be disposed in the center of the piezoelectric element 110. The first electrode 121 may be formed of a metal material. For example, the metal material forming the first electrode 121 may include aluminum.

The second electrode 122 may have an annular plate shape. The second electrode 122 may be spaced apart from the first electrode 121 in a radial direction and disposed outside the first electrode 121. The second electrode 122 may be formed of a metallic material. For example, the metal material forming the second electrode 122 may include aluminum.

The rear electrode part 130 may be located behind the piezoelectric element 110. The rear electrode unit 130 includes a rear electrode 131 coupled to the rear end of the piezoelectric element 110 opposite the first electrode 121 and the second electrode 122 based on the piezoelectric element 110. can do. The rear electrode 131 may have a circular plate shape, but is not limited thereto. The rear electrode 131 may cover at least a portion of the rear of the piezoelectric element 110. Preferably, the rear electrode 131 may cover the entire area behind the piezoelectric element 110. The rear electrode 131 may be formed of a metallic material. For example, the metal material forming the rear electrode 131 may include aluminum.

Although not shown, the sound wave generating device 10 may further include a waterproof member surrounding the front electrode unit 120 and the rear electrode unit 130. The waterproof member may protect the piezoelectric element 110, the front electrode unit 120, and the rear electrode unit 130 from water when the sound wave generating device 10 is disposed underwater. The waterproof member may have a flexible property. For example, the waterproof member may include plastic.

The control unit 140 is connected to the first electrode 121 and the second electrode 122 and controls the voltage applied to the first electrode 121 and the second electrode 122 to control the first electrode 121 and the second electrode 122. The electrode 122 may be driven. In one embodiment, the controller 140 may control a voltage applied to the first electrode 121 and the second electrode 122 so that both the first electrode 121 and the second electrode 122 are driven. In one embodiment, the controller 140 controls the voltage applied to the first electrode 121 and the second electrode 122 so that any one of the first electrode 121 and the second electrode 122 is selectively driven. can do. For example, the first electrode 121 may be driven and the second electrode 122 may not be driven. As another example, the second electrode 122 may be driven without the first electrode 121 being driven.

3 is a view for explaining the radiated sound pressure of the sound wave generating device according to an embodiment.

Referring to FIG. 3, the radiated sound pressure of the sound wave generating apparatus according to an exemplary embodiment is applied to the radiated sound pressure by the region S3 covering the first electrode 121 and the region S1 covering the second electrode 122. It can be determined based on the radiated sound pressure caused by. The term "radiated sound pressure" is used as a term referred to in consideration of the fact that when the piezoelectric element coupled to the electrode is driven, the piezoelectric element vibrates to generate sound pressure, and such vibration is radiated through the medium.

For example, the radiated sound pressure of the sound wave generator according to an embodiment may be determined according to the following equation.

<Equation 1>

는 음파 발생 장치의 방사 음압,

는 제2전극(122)의 외측 반지름(a)에 의해 결정되는 방사 음압,

는 제2전극(122)의 내측 반지름(b)에 의해 결정되는 방사 음압,

는 제1전극(121)의 반지름(c)에 의해 결정되는 방사 음압을 나타낸다.here,

Is the radiated sound pressure of the sound wave generating device,

Is the radiation sound pressure determined by the outer radius (a) of the second electrode 122,

Is the radiation sound pressure determined by the inner radius (b) of the second electrode 122,

Denotes the radiation sound pressure determined by the radius c of the first electrode 121.

)와, 중심부에 배치된 제1전극(121)의 중심으로부터 측정된 거리(r)에 의해 표현될 수 있다. 예를 들어, 상기와 같은 방사 음압은 다음의 수학식에 의해 표현될 수 있다.On the other hand, each radiation sound pressure is an angle (

) And a distance r measured from the center of the first electrode 121 disposed in the center. For example, the radiated sound pressure as described above may be expressed by the following equation.

<Equation 2>

는 제2전극(122)의 외측 반지름(a)에 의해 결정되는 방사 음압,

는 제2전극(122)의 외측 반지름(a)에 의해 결정되는 축 방향으로의 방사 음압,

는 영역(S1+S2+S3)에 의한 지향 지수를 나타낸다.here,

Is the radiation sound pressure determined by the outer radius (a) of the second electrode 122,

Is the radiation sound pressure in the axial direction determined by the outer radius (a) of the second electrode 122,

Represents the directivity index by the region (S1+S2+S3).

<Equation 3>

는 제2전극(122)의 내측 반지름(b)에 의해 결정되는 방사 음압,

는 제2전극(122)의 내측 반지름(b)에 의해 결정되는 축 방향으로의 방사 음압,

는 영역(S1+S2)에 의한 지향 지수를 나타낸다.here,

Is the radiation sound pressure determined by the inner radius (b) of the second electrode 122,

Is the radiation sound pressure in the axial direction determined by the inner radius (b) of the second electrode 122,

Represents the directivity index by the area (S1+S2).

<Equation 4>

는 제1전극(121)의 반지름(c)에 의해 결정되는 방사 음압,

는 제1전극(121)의 반지름(c)에 의해 결정되는 축 방향으로의 방사 음압,

는 영역(S1)에 의한 지향 지수를 나타낸다.here,

Is the radiation sound pressure determined by the radius (c) of the first electrode 121,

Is the radiation sound pressure in the axial direction determined by the radius (c) of the first electrode 121,

Represents the directivity index by the region S1.

와, 제1전극(121)이 존재하는 영역(S3) 및 전극이 존재하지 않는 영역(S2)에 의해 발생되는 방사 음압인

의 차를 계산한다. 다음으로, 음파 발생 장치의 전체 방사 음압인

를 계산하기 위해서, 위와 같이 계산된 방사 음압인

-

에, 제1전극(121)이 존재하는 영역(S3)에 의한 방사 음압인

를 더한다.As described above, in order to calculate the radiated sound pressure generated by the second electrode 122, the radiated sound pressure by S1+S2+S3, which is the entire area of the piezoelectric element, is

Wow, the radiation sound pressure generated by the region S3 in which the first electrode 121 exists and the region S2 in which the electrode does not exist.

Calculate the difference of. Next, the total radiated sound pressure of the sound wave generator

In order to calculate, the radiated sound pressure calculated as above is

-

E, which is the radiation sound pressure caused by the region S3 where the first electrode 121 is present.

Add

The structure of the sound wave generator determined by the above method has the advantage of being able to adjust the beam pattern compared to the structure of a single circular electrode. In other words, since the structure of a single circular electrode has a fixed radius a, there is no room for adjusting the beam pattern, but the structure of the sound wave generator according to an embodiment uses an annular electrode pattern divided into a plurality of regions. Therefore, it is possible to improve the beam pattern and generate highly directional sound waves by appropriately adjusting the radii b and c.

4 is a cross-sectional view of a sound wave generator according to another embodiment.

Referring to FIG. 4, a sound wave generating apparatus 10 ′ according to an exemplary embodiment may include a piezoelectric element 110, a front electrode unit 120 ′, a rear electrode unit 130, and a control unit 140. The front electrode part 120 ′ may include a first electrode 121, a second electrode 122, and a third electrode 123. The rear electrode unit 130 may include a rear electrode 131.

The third electrode 123 of the front electrode unit 120 ′ may be spaced apart from the second electrode 122 in a radial direction and coupled to the outer side of the piezoelectric element 110. The third electrode 123 may be formed of a metallic material. For example, the metal material forming the third electrode 123 may include aluminum.

It can be understood that the structure of the sound wave generator described above with reference to FIGS. 1 to 4 may include a plurality of electrodes divided into a plurality of regions within a predetermined space as long as they have an annular electrode pattern. In other words, the number of electrodes having an annular cross-sectional area is not necessarily limited to the two or three examples described above, and may be more, if necessary. In this case, the plurality of electrodes may be controlled by the controller to drive all or at least one or more of them. This is to achieve a desired beam pattern in consideration of the characteristics of the space in which the sound wave generator is installed, the characteristics of the medium, and the like.

Although the embodiments have been described by the limited embodiments and drawings as described above, various modifications and variations can be made from the above description to those of ordinary skill in the art. For example, the described techniques are performed in a different order from the described method, and/or components such as systems, structures, devices, circuits, etc. described are combined or combined in a form different from the described method, or other components Alternatively, even if substituted or substituted by an equivalent, an appropriate result can be achieved.

Claims (8)

In the sound wave generation system for a sono buoy used underwater to prevent the occurrence of a grating lobe and improve the directivity of a beam pattern,
The sound wave generating system includes a plurality of sound wave generating devices,
The plurality of sound wave generating devices,
Piezoelectric elements;
A circular first electrode coupled to the center of the piezoelectric element;
An annular second electrode spaced from the first electrode in a radial direction and coupled to an outer portion of the piezoelectric element; And
A waterproof member surrounding the piezoelectric element, the first electrode, and the second electrode;
Each containing,
The first electrode and the second electrode are arranged concentrically and point-symmetrically with respect to the center of the piezoelectric element,
The plurality of sound wave generating devices are arranged only in a line so as to have a radial direction in the same axial direction.
The method of claim 1,
The sound pressure of each of the plurality of sound wave generating devices is determined based on a first sound pressure radiated from a region covering the first electrode and a second sound pressure radiated from a region covering the second electrode.
The method of claim 2,
The first radiation sound pressure is determined by the radius of the first electrode,
The second radiated sound pressure is determined by an outer radius and an inner radius of the second electrode.
The method of claim 3,
A sound wave generating system wherein the radiated sound pressure of each of the plurality of sound wave generating devices is determined by the following equation.
<Equation>

(here,

,

,

ego,

Is the radiated sound pressure determined by the outer radius of the second electrode,

Is the radiation sound pressure determined by the inner radius of the second electrode,

Represents the radiated sound pressure determined by the radius of the first electrode,

Is a first orientation index determined by the outer radius of the second electrode,

Is a second orientation index determined by the inner radius of the second electrode,

Denotes a third orientation index determined by the radius of the first electrode,

Is the angle made with respect to the directional axis of the sound wave generator)
delete The method of claim 1,
Each of the plurality of sound wave generating devices further comprises at least one annular third electrode spaced from the second electrode in a radial direction and coupled to an outer portion of the piezoelectric element.
The method of claim 1,
The first electrode and the second electrode are coupled to any one of a front and a rear side of the piezoelectric element,
Each of the plurality of sound wave generating devices further includes an additional electrode coupled to the other one of a front and a rear side of the piezoelectric element. delete

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