JP6922347B2 - Wave transmitter and transmitter - Google Patents

Description

The present invention relates to a transmitter or the like, for example, a transmitter or the like that utilizes expansion and contraction of a piezoelectric element.

In order to transmit sound waves in water, a transmitter that utilizes the expansion and contraction of a piezoelectric element is used. Patent Document 1 discloses a low-frequency underwater transmitter as an example of a transmitter that utilizes expansion and contraction of a piezoelectric element. The low-frequency underwater transmitter described in Patent Document 1 includes two active disk bodies 30 (piezoelectric elements), two metal disks 31, and an O-ring 32. The O-ring 32 is sandwiched by the outer peripheral portions of the two metal discs 31 so that a gap is formed between the central portions of the two metal discs 31. Further, the active disk body 30 is provided on one surface of the metal disk 31. In the low-frequency underwater transmitter described in Patent Document 1, sound waves are transmitted by bending the active disk body 30 and the metal disk 31 by utilizing the expansion and contraction of the active disk body 30.

Japanese Unexamined Patent Publication No. 5-344582

When the low-frequency underwater transmitter described in Patent Document 1 is used underwater, hydrostatic pressure is applied to the entire low-frequency underwater transmitter. In the low-frequency underwater transmitter, a gap is formed between the central portions of the two metal discs 31, so that the two metal discs 31 are convex toward the gap side (inside) due to the hydrostatic pressure. Bends to. As a result, the active disk body 30 adhered to each of the two metal disks 31 also bends so as to be convex toward the gap side (inside). At this time, stress acts on the active disk body 30 along the plane direction of the active disk body 30. The force for bending the active disk body 30 so as to be convex toward the gap side (inside) increases from the outer edge side of the active disk body 30 toward the central portion. Therefore, a large stress acts on the central portion of the active disk body 30 as compared with the outer edge side. Therefore, the central portion of the active disk body 30 is easily damaged in water.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a transmitter or the like in which damage in water is suppressed.

The transmitter of the present invention includes a perforated piezoelectric element having a through hole in the central portion and a base material portion for holding the perforated piezoelectric element, and the perforated piezoelectric element is the first of the base material portions. It is held on the main surface side of.

According to the transmitter or the like of the present invention, damage in water can be suppressed.

It is a perspective view which shows the structure of the wave transmission device in 1st Embodiment of this invention. It is a top view of the wave transmitter in the 1st Embodiment of this invention. It is sectional drawing of the wave transmitter in 1st Embodiment of this invention. It is an exploded perspective view of a transmitter. It is an exploded perspective view of a transmitter. It is a perspective view of the base material part. It is a perspective view of the base material part. It is a perspective view of the perforated piezoelectric element. It is a perspective view of the non-porous piezoelectric element. It is a figure for demonstrating operation of a wave transmitter in 1st Embodiment of this invention. It is a figure for demonstrating operation of a wave transmitter in 1st Embodiment of this invention. It is a figure for demonstrating operation of a wave transmitter in 1st Embodiment of this invention. It is a figure for demonstrating operation of a wave transmitter in 1st Embodiment of this invention. It is a figure for demonstrating a specific example of a wave transmitter in 1st Embodiment of this invention. It is a perspective view which shows the structure of the modification of the wave transmitter in 1st Embodiment of this invention. It is a perspective view of the base material part. It is a perspective view of the base material part. It is a perspective view of the perforated piezoelectric element. It is a perspective view of the non-porous piezoelectric element. It is a perspective view which shows the structure of the wave transmission device in 2nd Embodiment of this invention. It is an exploded perspective view of a transmitter. It is an exploded perspective view of a transmitter. It is sectional drawing of a transmitter. It is a figure for demonstrating the operation of the wave transmitter in the 2nd Embodiment of this invention. It is a figure for demonstrating the operation of the wave transmitter in the 2nd Embodiment of this invention. It is a figure for demonstrating the operation of the wave transmitter in the 2nd Embodiment of this invention. It is a figure for demonstrating the operation of the wave transmitter in the 2nd Embodiment of this invention. It is a perspective view which shows the structure of the wave transmission device in 3rd Embodiment of this invention. It is an exploded perspective view of a transmitter. It is an exploded perspective view of a transmitter. It is sectional drawing of a transmitter. It is a figure for demonstrating the operation of the wave transmitter in the 3rd Embodiment of this invention. It is a figure for demonstrating the operation of the wave transmitter in the 3rd Embodiment of this invention. It is a figure for demonstrating the operation of the wave transmitter in the 3rd Embodiment of this invention. It is a figure for demonstrating the operation of the wave transmitter in the 3rd Embodiment of this invention.

(First Embodiment)
The wave transmitting device 100 according to the first embodiment will be described with reference to the drawings. FIG. 1 is a perspective view showing the entire wave transmitting device 100. FIG. 2 is a top view of the wave transmitter 100. FIG. 3 is a cross-sectional view of the wave transmitting device 100 when the transmitting device 100 is cut at the AA disconnection surface of FIG.

For example, the wave transmitter 100 shown in FIGS. 1 to 3 is molded with urethane resin or the like and then mounted in a water pressure resistant container of an active sonar device. The water pressure resistant container is filled with water. Further, for example, the wave transmission device 100 is connected to a signal generation unit (not shown) that outputs an electric signal having a predetermined frequency via a signal amplification unit (not shown).

As shown in FIGS. 1 and 3, the transmitter 100 includes transmitters 110a and 110b and a junction 150. Further, the transmitter 110a and the transmitter 110b are arranged so as to face each other. As shown in FIG. 3, the transmitter 110a includes a base material portion 120a, a perforated piezoelectric element 130a, and a non-perforated piezoelectric element 140a. Further, the transmitter 110b includes a base material portion 120b, a perforated piezoelectric element 130b, and a non-perforated piezoelectric element 140b. In the following description, when the transmitters 110a and 110b are not distinguished, they are referred to as the transmitter 110. Similarly, when the components included in the transmitter 110a and the components included in the transmitter 110b are not distinguished, a or b is not added to the names of the respective components. For example, when the perforated piezoelectric element 130a and the perforated piezoelectric element 130b are not distinguished, the perforated piezoelectric element 130 is used.

Next, each of the configurations of the transmitter 110 will be described. FIG. 4 is an exploded perspective view of the transmitter 110 as viewed from the perforated piezoelectric element 130 side. FIG. 5 is an exploded perspective view of the transmitter 110 as viewed from the non-perforated piezoelectric element 140 side. As shown in FIGS. 3 to 5, the transmitter 110 includes a base material portion 120, a perforated piezoelectric element 130, and a non-perforated piezoelectric element 140.

The base material portion 120 will be described with reference to FIGS. 3 to 7. 6 and 7 are perspective views showing the configuration of the base material portion 120. As shown in FIGS. 3 to 7, the base material portion 120 has a first main surface 121, a first recess 122, a protrusion 123, a second main surface 124, and a second recess 125. For example, high-strength steel such as an aluminum alloy can be used as the material of the base material portion 120.

The first main surface 121 is a surface that constitutes the outer shape of the base material portion 120. The first main surface 121 is a surface opposite to the second main surface 124. As shown in FIGS. 3, 4 and 6, the first main surface 121 is composed of an annular surface having a circular outer circumference and an inner circumference, and a circular surface (the surface of the protrusion 123 described later). ing. These two surfaces are formed on the same surface as shown in FIGS. 3, 4 and 6.

The first recess 122 is formed on the side of the first main surface 121 of the base material portion 120. As shown in FIGS. 4 and 6, for example, the shape of the first recess 122 is a prism whose bottom surface is an annular surface having a circular outer circumference and inner circumference. As shown in FIG. 4, a perforated piezoelectric element 130 is attached to the first recess 122.

The protrusion 123 is formed on the first main surface 121 side of the base material 120. The protrusion 123 is inserted into a through hole 131 described later in the perforated piezoelectric element 130. As shown in FIGS. 4 and 6, for example, the protrusion 123 is formed in a columnar shape. As described above, the surface of the protrusion 123 on the tip end side constitutes a part of the first main surface 121.

The second main surface 124 is one surface of the base material portion 120. Further, the second main surface 124 is a surface opposite to the first main surface 121. As shown in FIGS. 5 and 7, for example, the second main surface 124 is a surface having a circular outer circumference and an inner circumference.

The second recess 125 is formed on the second main surface 124 side of the base material portion 120. For example, as shown in FIGS. 5 and 7, the shape of the second recess 125 is cylindrical. As shown in FIGS. 4 and 5, a non-perforated piezoelectric element 140 is attached to the second recess 145.

Next, the perforated piezoelectric element 130 will be described. FIG. 8 is a perspective view of the perforated piezoelectric element 130. As shown in FIGS. 4, 5 and 8, the perforated piezoelectric element 130 has a through hole 131 in the central portion. For example, as shown in FIG. 8, the shape of the perforated piezoelectric element 130 is a prism shape having a surface having a circular outer circumference and inner circumference as a bottom surface. Further, the shape of the through hole 131 is, for example, a columnar shape. Further, the perforated piezoelectric element 130 is polarized in the thickness direction of the perforated piezoelectric element 130 (the direction indicated by the arrow P shown in FIG. 8) by the polarization treatment. Specifically, in the perforated piezoelectric element 130 that has been subjected to the polarization treatment in advance, the negative charge is biased toward the start point side of the arrow P. Further, in the perforated piezoelectric element 130 which has been subjected to the polarization treatment in advance, the positive charge is biased toward the end point side of the arrow P. Therefore, the perforated piezoelectric element 130 expands and contracts by applying a voltage in the direction of the arrow P. Specifically, the perforated piezoelectric element 130 is formed by applying an electric potential to each of the upper surface (upper surface on the paper surface of FIG. 8) and the lower surface (lower surface on the paper surface of FIG. 8) of the perforated piezoelectric element 130. Radiates from the center of the upper surface of the perforated piezoelectric element 130 and the center of the lower surface of the perforated piezoelectric element 130. A specific description of the expansion and contraction of the perforated piezoelectric element 130 will be described in the description of the operation of the wave transmitter 100 described later.

Further, the perforated piezoelectric element 130 is overlapped with the base material portion 120 as shown in FIGS. 4 and 5, and then fixed to the first recess 122 as shown in FIGS. 1 and 3. The perforated piezoelectric element 130 is fixed to the first recess 122 with an adhesive or the like. At this time, the side surface of the perforated piezoelectric element 130 is adhered to the side surface of the first recess 122. Further, the side surface of the through hole 131 of the perforated piezoelectric element 130 is adhered to the side surface of the protrusion 123. In this way, the perforated piezoelectric element 130 is held on the first main surface 121 side. As a result, stress concentration generated in the outer peripheral portion of the through hole 131 of the perforated piezoelectric element 130 can be suppressed. As shown in FIGS. 3 and 4, when the perforated piezoelectric element 130 is held on the first main surface 121 side, the surface of the perforated piezoelectric element 130 on the first main surface 121 side (FIG. 4). The upper surface of the perforated piezoelectric element 130 on the paper surface) is arranged on the same surface as the first main surface 121.

As the material of the perforated piezoelectric element 130, for example, a piezoelectric ceramic can be used. Piezoelectric ceramics have the advantage of having a high electromechanical coupling coefficient as compared to other piezoelectric elements (piezoelectric thin films, etc.). The electromechanical coupling coefficient is a coefficient indicating the efficiency with which electromagnetic energy is converted into mechanical energy. That is, when a voltage equal to each of the piezoelectric ceramic and the other piezoelectric element (piezoelectric thin film, etc.) is applied, the piezoelectric ceramic expands and contracts significantly as compared with the other piezoelectric element (piezoelectric thin film, etc.). For this reason, piezoelectric ceramics are widely used as piezoelectric elements.

On the other hand, the piezoelectric ceramic is, for example, a member obtained by baking powder (titanium oxide, barium oxide, etc.). Therefore, the piezoelectric ceramic is generally a member having a characteristic that the elastic limit for compressive stress is larger than the elastic limit for tensile stress. That is, the piezoelectric ceramic has a characteristic that it is strong against compressive stress but brittle against tensile stress.

Further, since the resonance frequency of the perforated piezoelectric element 130 depends on the thickness of the member, the perforated piezoelectric element 130a and the perforated piezoelectric element 130b have the perforated piezoelectric element 130a and the perforated piezoelectric element 130a so that the resonance frequencies do not match each other. The hole piezoelectric elements 130b are formed so as to have different thicknesses.

Next, the non-porous piezoelectric element 140 will be described. FIG. 9 is a perspective view of the non-porous piezoelectric element 140. The non-perforated piezoelectric element 140 does not have a through hole. As shown in FIG. 9, for example, the shape of the non-porous piezoelectric element 140 is cylindrical. The non-porous piezoelectric element 140 is polarized in the thickness direction of the non-porous piezoelectric element 140 (the direction indicated by the arrow P in FIG. 9) by the polarization treatment. Specifically, in the non-porous piezoelectric element 140 that has been subjected to the polarization treatment in advance, the negative charge is biased toward the start point side of the arrow P. Further, in the non-porous piezoelectric element 140 that has been subjected to the polarization treatment in advance, the positive charge is biased toward the end point side of the arrow P. Therefore, the perforated piezoelectric element 130 expands and contracts by applying a voltage in the direction of the arrow P. Specifically, the non-perforated piezoelectric element is formed by applying an electric potential to each of the upper surface (upper surface on the paper surface of FIG. 9) and the lower surface (lower surface on the paper surface of FIG. 9) of the non-perforated piezoelectric element 140. The 140 expands and contracts radially from the center of the upper surface of the non-perforated piezoelectric element 140 and the center of the lower surface of the non-perforated piezoelectric element 140. A specific description of the expansion and contraction of the non-porous piezoelectric element 140 will be described in the description of the operation of the wave transmitter 100 described later.

Further, the non-perforated piezoelectric element 140 is overlapped with the base material portion 120 as shown in FIGS. 4 and 5, and then fixed to the second recess 125 as shown in FIGS. 1 and 3. The non-porous piezoelectric element 140 is fixed to the second recess 125 with an adhesive or the like. At this time, the side surface of the non-perforated piezoelectric element 140 is adhered to the side surface of the second recess 125. In this way, the non-porous piezoelectric element 140 is held on the second main surface 124 side. As shown in FIG. 3, when the non-perforated piezoelectric element 140 is held on the first main surface 121 side, the surface of the non-perforated piezoelectric element 140 on the second main surface 124 side (on the paper surface of FIG. 4). The upper surface of the non-perforated piezoelectric element 140) is arranged on the same surface as the second main surface 124.

For the non-porous piezoelectric element 140, for example, a piezoelectric ceramic can be used. Further, since the resonance frequency of the non-perforated piezoelectric element 140 depends on the thickness of the member, the non-perforated piezoelectric element 140a and the non-perforated piezoelectric element 140b are the non-perforated piezoelectric element 140a and the non-perforated piezoelectric element 140a so that the resonance frequencies do not match each other. The hole piezoelectric elements 140b are formed so as to have different thicknesses.

As shown in FIG. 3, the upper surface and the lower surface of the perforated piezoelectric element 130 and the non-perforated piezoelectric element 140 are arranged so as to be parallel to each other.

The configuration of the transmitter 110 has been described above.

The joint portion 150 will be described with reference to FIGS. 1 and 3. The joint portion 150 is a ring-shaped member. As shown in FIG. 3, the joint portion 150 is sandwiched between the base material portion 120a of the transmitter 110a and the base material portion 120b of the transmitter 110b. Specifically, the joint portion 150 is sandwiched by the outer peripheral portion of the first main surface 141 of each base material portion 120 of the transmitter 110a and the transmitter 110b. As a result, the central portions of the transmitter 110a and the transmitter 110b face each other through the gap. At this time, as shown in FIG. 3, the first main surface 121a of the transmitter 110a and the first main surface 121b of the transmitter 110b are arranged so as to face each other with a gap. For example, maraging steel or the like can be used as the material of the joint portion 150.

The configuration of the wave transmitter 100 has been described above.

Next, the operation of the wave transmitting device 100 will be described with reference to FIGS. 10 to 13. 10 to 13 are cross-sectional views for explaining the operation of the wave transmitting device 100. The cross-sectional views shown in FIGS. 10 and 12 are views in which an arrow indicating the expansion / contraction direction of the piezoelectric element is added to the cross-sectional view shown in FIG.

Using FIGS. 10 and 11, the transmitter 110a and the transmitter 110a and the transmitter 110b are moved so that the central portions of the transmitter 110a and the transmitter 110b move away from each other (the direction indicated by the arrow Δ1 in FIG. 11). The operation of bending the 110b will be described. FIG. 10 shows the polarization directions P of the perforated piezoelectric elements 130a and 130b and the non-perforated piezoelectric elements 140a and 140b. As shown in FIG. 10, the polarization directions P of the perforated piezoelectric elements 130a and 130b and the non-perforated piezoelectric elements 140a and 140b are set in a direction away from the joint portion 150.

First, the potential V1 is applied to the surface of the non-porous piezoelectric element 140 on the second main surface 124 side, and the potential V2 is applied to the surface of the non-porous piezoelectric element 140 on the first main surface 121 side (potential V1>. Let it be V2). As a result, the non-perforated piezoelectric element 140 extends radially from the central portion to the outer edge portion of the non-perforated piezoelectric element 140 in a direction parallel to the bottom surface (direction indicated by the arrow α in FIG. 10). As a result, on the side surface (hereinafter, referred to as "the surface including the second main surface 124") of each of the transmitter 110a and the transmitter 110b on which the non-perforated piezoelectric element 140 is provided, the second surface is provided. A force acts in a direction that spreads radially from the central portion of the surface including the main surface 124 of the above to the outer edge portion.

Further, the potential V1 is applied to the surface on the first main surface 121 side of the perforated piezoelectric element 130, and the potential V2 is applied to the surface on the second main surface 124 side of the perforated piezoelectric element 130 (potential V1>. Let it be V2). As a result, the perforated piezoelectric element 130 contracts radially from the outer edge portion to the central portion of the perforated piezoelectric element 130 in the direction parallel to the bottom surface (the direction indicated by the arrow β in FIG. 10). As a result, on the surface of each of the transmitter 110a and the transmitter 110b on the side where the perforated piezoelectric element 130 is provided (hereinafter, referred to as "the surface including the first main surface 121"), the first surface is provided. A force that contracts radially from the outer edge portion of the surface including the main surface 121 to the central portion acts.

In this way, the force spreading from the central portion toward the outer edge portion acts on the surface including the second main surface 124, while the force contracting from the outer edge portion toward the central portion acts on the surface including the first main surface 121. Acts on. As a result, as shown in FIG. 11, the transmitter 110a and the transmitter 110a and the transmitter 110b are moved so that the central portions of the transmitter 110a and the transmitter 110b move away from each other (the direction indicated by the arrow Δ1 in FIG. 11). Each of the wave devices 110b bends.

As described above, the transmitter 110a and the transmitter 110b are moved so that the central portions of the transmitter 110a and the transmitter 110b move away from each other (the direction indicated by the arrow Δ1 in FIG. 11). And the operation of bending the transmitter 110b has been described.

Using FIGS. 12 and 13, the transmitter 110a and the transmitter 110a and the transmitter 110b move in the direction in which the central portions of the transmitter 110a and the transmitter 110b approach each other (the direction indicated by the arrow Δ2 in FIG. 13). The operation of bending the 110b will be described. FIG. 12 shows the polarization directions P of the perforated piezoelectric elements 130a and 130b and the non-perforated piezoelectric elements 140a and 140b. As shown in FIG. 12, the polarization directions P of the perforated piezoelectric elements 130a and 130b and the non-perforated piezoelectric elements 140a and 140b are set in a direction away from the joint portion 150.

First, the potential V2 is applied to the surface of the non-porous piezoelectric element 140 on the second main surface 124 side, and the potential V1 is applied to the surface of the non-porous piezoelectric element 140 on the first main surface 121 side (potential V1>. Let it be V2). As a result, the non-perforated piezoelectric element 140 contracts radially from the outer edge portion to the central portion of the non-perforated piezoelectric element 140 in the direction parallel to the bottom surface (the direction indicated by the arrow β in FIG. 12). As a result, on the surface of each of the transmitter 110a and the transmitter 110b including the second main surface 124, the force of radially contracting from the outer edge portion to the central portion of the surface including the second main surface 124 is applied. It works.

Further, the potential V2 is applied to the surface on the first main surface 121 side of the perforated piezoelectric element 130, and the potential V1 is applied to the surface on the second main surface 124 side of the perforated piezoelectric element 130 (potential V1>. Let it be V2). As a result, the perforated piezoelectric element 130 extends from the central portion to the outer edge portion of the perforated piezoelectric element 130 in the direction parallel to the bottom surface (the direction indicated by the arrow α in FIG. 12). As a result, on the surface of each of the transmitter 110a and the transmitter 110b including the first main surface 121, a force spreading from the central portion of the surface including the first main surface 121 toward the outer edge portion acts.

In this way, the force spreading from the central portion toward the outer edge portion acts on the surface including the first main surface 121, while the force contracting from the outer edge portion toward the central portion acts on the second main surface 124. .. As a result, as shown in FIG. 13, the transmitter 110a and the transmitter 110a and the transmitter 110a and the transmitter 110b move in the direction in which the central portions of the transmitter 110a and the transmitter 110b approach each other (the direction indicated by the arrow Δ2 in FIG. 13). The wave device 110b bends. At this time, the transmitter 110a and the transmitter 110b bend to the extent that they do not come into contact with each other.

The operation of bending the transmitter 110a and the transmitter 110b will be described above so that the central portions of the transmitter 110a and the transmitter 110b move in the direction closer to each other (the direction indicated by the arrow Δ2 in FIG. 12). bottom.

In this way, each of the transmitter 110a and the transmitter 110b alternately applies the potential V1 or the potential V2 to the upper surface and the lower surface of each of the perforated piezoelectric element 130 and the non-perforated piezoelectric element 140 in opposite directions. Continuously bends to. Specifically, the transmitter 110a and the transmitter 110b are bent so that the central portions of the transmitter 110a and the transmitter 110b move away from each other (the direction indicated by the arrow Δ1 in FIG. 11). Further, the transmitter 110a and the transmitter 110b are bent so that the central portions of the transmitter 110a and the transmitter 110b move in a direction approaching each other (the direction indicated by the arrow Δ2 in FIG. 12).

The wave transmitting device 100 vibrates the water in the water pressure resistant container by repeating this operation, and vibrates the water pressure resistant container. The wave transmitting device 100 transmits sound waves in deep water by vibrating the water pressure resistant container.

The operation of the wave transmitter 100 has been described above.

Next, the significance of the perforated piezoelectric element 130 having the through hole 131 will be described.

First, when the transmitter 100 is used underwater, a hydrostatic pressure is applied to the entire transmitter 100, so that the central portions of the transmitter 110a and the transmitter 110b approach each other (FIG. 13). It bends in the direction indicated by the arrow Δ2. At this time, the surfaces including the first main surface 121 of each of the transmitter 110a and the transmitter 110b are bent. As a result, tensile stress acts on the perforated piezoelectric element 130 held on the first main surface 121 side. Generally, the tensile stress (bending stress) applied to the central portion of the member is larger than the tensile stress applied to the outer peripheral portion of the member. Therefore, in order to prevent a large tensile stress from being applied to the central portion, a through hole 131 is provided in the central portion of the perforated piezoelectric element 130. As a result, it is possible to prevent the tensile stress applied to the perforated piezoelectric element 130 from exceeding the elastic limit of the perforated piezoelectric element 130. That is, it is possible to prevent the perforated piezoelectric element 130 from being damaged.

The significance of the perforated piezoelectric element 130 having the through hole 131 has been described above.

Next, a specific example of the wave transmitting device 100 will be described with reference to FIG. FIG. 14 is a plan view showing a view of the transmitter 110 in a specific example of the transmitter 100 when viewed from the first main surface 121 side. In a specific example of the wave transmitting device 100, the area of the region surrounded by the line of intersection with the first main surface 121 and the side surface of the through hole 131 is set. For example, the area of the region (S1 shown in FIG. 14) surrounded by the line of intersection between the circular surface of the first main surface 121 and the side surface of the through hole 131 is the annular shape of the first main surface 121. It is set to be 9% or more and 64% or less of the area of the area (S3 shown in FIG. 14) surrounded by the outer circumference of the surface. Further, for example, the area of the region (S2 shown in FIG. 14) surrounded by the outer edge of the perforated piezoelectric element 130 is the region surrounded by the outer circumference of the annular surface of the first main surface 121 (shown in FIG. 14). It is set to be about 72% of the area of S3).

Further, the region surrounded by the line of intersection between the circular surface of the first main surface 121b and the side surface of the through hole 131 is circular, and is surrounded by the outer circumference of the annular surface of the first main surface 121. It is assumed that the area is circular. For example, in this case, the radius (D1 shown in FIG. 14) of the region (S1 shown in FIG. 14) surrounded by the line of intersection between the circular surface of the first main surface 121b and the side surface of the through hole 131 is , 30% or more and 80% or less of the radius (D3 shown in FIG. 14) of the region (S3 shown in FIG. 14) surrounded by the outer circumference of the annular surface of the first main surface 121. It is set. Further, for example, the radius (D2 shown in FIG. 14) of the region (S2 shown in FIG. 14) surrounded by the outer edge of the perforated piezoelectric element 130 is the outer circumference of the annular surface of the first main surface 121. It is set to be 85% of the radius (D3 shown in FIG. 14) of the area surrounded by (S3 shown in FIG. 14).

The specific example of the wave transmitting device 100 has been described above.

Next, the wave transmitting device 100', which is a modification of the transmitting device 100, will be described. FIG. 15 is a perspective view showing the appearance of the wave transmitter 100'. 16 and 17 are perspective views showing the outer shape of the base material portion 120'of the wave transmitting device 100'. FIG. 18 is a perspective view showing the outer shape of the perforated piezoelectric element 130 ′ in the wave transmitting device 100 ′. FIG. 19 is a perspective view showing the outer shape of the non-perforated piezoelectric element 140'in the wave transmitting device 100'.

The base material portion 120 ′ in the wave transmitting device 100 ′ will be described with reference to FIGS. 15 to 17. In the description of the wave transmitting device 100, it has been explained that the first main surface 121 of the base material portion 120 is a surface having a circular outer circumference and an inner circumference, but the first main surface 121 of the base material portion 120'in the transmitting device 100'is the first. As shown in FIG. 16, the main surface 121'is a surface having a rectangular outer circumference and inner circumference.

Further, in the description of the wave transmitting device 100, it has been explained that the first recess 122 of the base material portion 120 has a prism whose bottom surface is an annular surface. As shown in FIG. 16, the recess 122'of 1 is a pillar having a surface having a rectangular outer circumference and inner circumference as a bottom surface.

Further, in the description of the wave transmitting device 100, the shape of the protruding portion 123 of the base material portion 120 has been described as a cylinder, but the shape of the protruding portion 123'of the base material portion 120'in the wave transmitting device 100'is shown in FIG. It is rectangular parallelepiped as shown in 16.

Further, in the description of the wave transmitter 100, it has been explained that the second main surface 124'of the base material portion 120'is a surface having a circular outer circumference and an inner circumference, but the base material portion 120'in the base material portion 100' The second main surface 124'is a surface having a rectangular outer circumference and inner circumference as shown in FIG.

Further, in the description of the wave transmitting device 100, it has been explained that the shape of the second recess 125 of the base material portion 120 is cylindrical, but the shape of the second recess 125'in the wave transmitting device 100'is shown in FIG. It is rectangular parallelepiped as shown in.

The shapes of the first main surface 121 ′, the first recess 122 ′, the protrusion 123 ′, the second main surface 124 ′ and the second recess 125 ′ of the base material portion 120 ′ in the wave transmitting device 100 ′. May have a shape other than those described above.

The perforated piezoelectric element 130 ′ in the wave transmitting device 100 ′ will be described with reference to FIG. In the description of the wave transmitting device 100, it has been explained that the perforated piezoelectric element 130 has a columnar shape having a circular surface as the bottom surface, but the perforated piezoelectric element 130'in the wave transmitting device 100'is , As shown in FIG. 18, it has a rectangular parallelepiped shape having a through hole in the central portion. The perforated piezoelectric element 130'may have other shapes. The shape of the through hole 131'shown in FIG. 18 is a rectangular parallelepiped, but may have other shapes. The configuration, connection relationship, and function of the perforated piezoelectric element 130'in the wave transmitting device 100'are the same as those of the perforated piezoelectric element 130 of the wave transmitting device 100, except for the above points. When the perforated piezoelectric element 130'is used in the wave transmitting device 100', the first recess 122'and the protrusion 123' are preferably formed so as to correspond to the shape of the perforated piezoelectric element 130'. For example, when the shape of the perforated piezoelectric element 130'is the shape shown in FIG. 18, the shape of the first recess 122'preferably is formed in a shape capable of accommodating the perforated piezoelectric element 130'. .. Further, for example, the shape of the protrusion 123'is preferably the same as that of the through hole 131'.

The non-perforated piezoelectric element 140'in the wave transmitting device 100' will be described with reference to FIG. In the description of the wave transmitting device 100, the non-hole piezoelectric element 140 has been described as having a columnar shape, but the non-hole piezoelectric element 140'in the wave transmitting device 100'has a rectangular parallelepiped shape as shown in FIG. Further, the non-porous piezoelectric element 140'may have other shapes. The configuration, connection relationship, and function of the non-perforated piezoelectric element 140'in the wave transmitting device 100'are the same as those of the non-perforated piezoelectric element 140 of the transmitting device 100, except for the above points. When the non-perforated piezoelectric element 140'is used in the wave transmitting device 100', the second recess 125'is preferably formed so as to correspond to the shape of the non-perforated piezoelectric element 140'. For example, when the shape of the non-perforated piezoelectric element 140'is the shape shown in FIG. 19, the shape of the second recess 125'preferably is formed in a shape capable of accommodating the non-perforated piezoelectric element 140'. ..

The wave transmitter 100', which is a modification of the transmitter 100, has been described above. The operation of the wave transmitting device 100'is the same as the operation of the transmitting device 100.

As described above, the transmitter 110 described in the present embodiment includes the base material portion 120 and the perforated piezoelectric element 130. The perforated piezoelectric element 130 has a through hole 131 in the central portion. Further, the base material portion 120 holds the perforated piezoelectric element 130. The perforated piezoelectric element 130 is held on the first main surface 121 side of the base material portion 120.

When the transmitter 110 is used underwater, a hydrostatic pressure is applied to the entire transmitter 110, so that the central portion of the first main surface 121 of the transmitter 110 projects with respect to the outer peripheral portion. Transforms into. At this time, the surface opposite to the first main surface 121 (second main surface 124) is deformed so that the central portion is recessed with respect to the outer peripheral portion. This deformation causes the perforated piezoelectric element 130 to bend. Further, when the transmitter 110 is operating, the perforated piezoelectric element 130 also bends due to the expansion and contraction of the perforated piezoelectric element 130. Therefore, when the transmitter 110 is operating, a large tensile stress is applied to the perforated piezoelectric element 130 as compared with the case where the transmitter 110 is not operating. Further, in general, the stress applied to the central portion of the member (bending stress) is larger than the stress applied to the outer peripheral portion of the member. Therefore, the perforated piezoelectric element 130 has a through hole 131 in the central portion. Therefore, no tensile stress is applied to the central portion of the perforated piezoelectric element 130. As a result, the tensile stress applied to the perforated piezoelectric element 130 can be made less likely to reach the elastic limit of the perforated piezoelectric element 130. As a result, damage to the perforated piezoelectric element 130 can be suppressed. In this way, according to the transmitter 110, it is possible to prevent the perforated piezoelectric element 130 from being damaged, so that sound waves can be continuously transmitted.

As described above, the transmitter 110 according to the present embodiment further includes a protrusion formed on the base material portion 120. Further, the perforated piezoelectric element 130 is held by the base material portion 120 after the through hole 131 is attached to the protrusion portion 123.

Generally, when a tensile stress acts on a member on which a through hole 131 is formed, the stress is concentrated on the outer peripheral portion of the through hole in the member. Therefore, the perforated piezoelectric element 130 is held by the base material portion 120 after the through hole 131 is attached to the protrusion 123 so that the stress is not concentrated on the perforated piezoelectric element 130. As a result, the cross-sectional area of the transmitter 110 including the region where the through hole 131 is formed is not smaller than that when the through hole 131 is not formed. Therefore, in the transmitter 110, the stress is not concentrated on the perforated piezoelectric element 130. As a result, in the transmitter 110, it is possible to prevent the perforated piezoelectric element 130 from being damaged.

In the transmitter 110 of the present embodiment, the non-perforated piezoelectric element 140 having no through hole is further held on the second main surface 124 side opposite to the first main surface 121 side of the base material portion 120. ing.

As described above, the transmitter 110 includes the perforated piezoelectric element 130 on the first main surface 121 side, and further includes the non-perforated piezoelectric element 140 on the second main surface 124 side. In general, it is known that the larger the amount of deflection (deformation amount) of the base material portion, the larger the output of the sound wave can be transmitted by the transmitter. Therefore, by including the perforated piezoelectric element 130 and the non-perforated piezoelectric element 140, the transmitter 110 can flex the base material portion 120 more than the case where only the perforated piezoelectric element 130 is provided. That is, the transmitter 110 can transmit a sound wave having a larger output.

The transmitter 100 of the present embodiment is provided so that the transmitter 110a and the transmitter 110b face each other with a gap.

As described above, in the transmitter 100, the transmitter 110a and the transmitter 110b are provided so as to face each other with the gap between them. Therefore, in the wave transmitter 100, the transmitter 110a and the transmitter 110b are suppressed from coming into contact with each other. As a result, it is possible to prevent the transmitter 100 from being damaged due to the transmitter 110a and the transmitter 110b coming into contact with each other. As a result, the transmitter 100 can suppress a decrease in the output of sound waves due to damage to each of the transmitter 110a and the transmitter 110b due to contact with each other. Further, since the wave transmitter 100 includes two wave transmitters 110, the sound wave can be transmitted with a larger output than when the sound wave is transmitted by one wave transmitter 110.

The base material portion 120 of the transmitter 110a and the base material portion 120 of the transmitter 110b are arranged so that their first main surfaces 121 face each other. Further, the perforated piezoelectric element 130 is composed of a member whose elastic limit for compressive stress is larger than the elastic limit for tensile stress.

As described above, the base material portion 120a of the transmitter 110a and the base material portion 120b of the transmitter 110b are arranged so that their first main surfaces 141 face each other. As a result, the perforated piezoelectric element 130 of the transmitter 110a and the perforated piezoelectric element 130b of the transmitter 110b are arranged inside the transmitter 100. Therefore, as described above, when the wave transmitter 100 is used in water, tensile stress is applied to the perforated piezoelectric element 130 held on the first main surface 141 side. However, since the perforated piezoelectric element 130 has a through hole 131 in the central portion, no tensile stress is applied to the central portion of the perforated piezoelectric element 130. As a result, the tensile stress applied to the perforated piezoelectric element 130 is suppressed from reaching the elastic strength as compared with the tensile stress applied to the piezoelectric element in which the holes are not formed.

The transmitter 100 further includes a junction 150 that joins the transmitter 110a and the transmitter 110b so that the transmitter 110a and the transmitter 110b face each other through a gap.

As described above, the wave transmitting device 100 includes the joint portion 150. Therefore, the transmitter 110a and the transmitter 110b are joined more stably.
(Second embodiment)
Next, the wave transmitter 100A according to the second embodiment will be described with reference to FIGS. 20 to 27. Further, in the description of the present embodiment, the same reference numerals are given to the configurations having the same configurations, connection relationships and functions as those of the wave transmitter 100 according to the first embodiment. Note that FIG. 20 is a perspective view showing the configuration of the wave transmitting device 100A.

As shown in FIG. 20, the transmitter 200 includes two second transmitters 110A and a junction 150. Here, the wave transmitter 100 in the first embodiment and the wave transmitter 100A in the present embodiment are compared. In the description of the transmitter 100 in the first embodiment, it is assumed that the transmitter 100 includes two transmitters 110 (hereinafter, referred to as "first transmitter 110"). On the other hand, the transmitter 100A in the present embodiment includes two second transmitters 110A instead of the two first transmitters 110.

The configuration of the second transmitter 110A will be described with reference to FIGS. 21 to 23. FIG. 21 is a perspective view of the second transmitter 110A as seen from the first main surface 121 side. FIG. 22 is a perspective view of the second transmitter 110A as seen from the second main surface 124 side. FIG. 23 is a cross-sectional view of the central portion of the second transmitter 110A. As shown in FIGS. 21 to 23, the second transmitter 110A includes a second base material portion 120A and a perforated piezoelectric element 130. Here, the second transmitter 110A and the first transmitter 110 shown in FIGS. 3 to 5 are compared.

In the first transmitter 110 and the second transmitter 110A, the first transmitter 110 has the non-perforated piezoelectric element 140, while the second transmitter 110A has the non-perforated piezoelectric element 140. It differs in that it does not exist.

Further, in the first transmitter 110 and the second transmitter 110A, the first transmitter 110 has a base material portion 120 (hereinafter, referred to as "first base material portion 120"). On the other hand, the second transmitter 110A is different in that it has a second base material portion 120A instead of the first base material portion 120. The second base material portion 120A will be described with reference to FIGS. 21 to 23. As shown in FIGS. 21 to 23, the second base material portion 120A includes a first main surface 121, a first recess 122, a protrusion 123, and a second main surface 124. Here, the second base material portion 120A and the first base material portion 120 shown in FIG. 6 are compared. In the second base material portion 120A and the first base material portion 120, the first base material portion 120 has the second recess 125, while the second base material portion 120A has the second recess 125. It differs in that it does not have.

Further, in the description of the first embodiment, it has been described that the second main surface 124 is a surface having a circular outer circumference and an inner circumference, but the second main surface 124 in the present embodiment is circular.

The configuration of the wave transmitter 100A has been described above.

Next, the operation of the wave transmitter 100A will be described with reference to FIGS. 24 to 27. 24 to 27 are cross-sectional views for explaining the operation of the wave transmitter 100A.

Using FIGS. 24 and 25, the two second transmitters are used so that the central portions of the two second transmitters 110A move away from each other (the direction indicated by the arrow Δ3 in FIG. 25). The operation of bending the 110A will be described. FIG. 24 shows the polarization direction P of each of the perforated piezoelectric elements 130 of the two second transmitters 110A. As shown in FIG. 24, the polarization direction P of each of the perforated piezoelectric elements 130 of the two second transmitters 110A is set in a direction away from the junction 150.

First, the potential V1 is applied to the surface on the first main surface 121 side of the perforated piezoelectric element 130, and the potential V2 is applied to the surface on the second main surface 124 side of the perforated piezoelectric element 130 (potential V1>. Let it be V2). As a result, the perforated piezoelectric element 130 contracts radially from the outer edge portion to the central portion of the perforated piezoelectric element 130 in the direction parallel to the bottom surface (the direction indicated by the arrow β in FIG. 24). As a result, on the surface of each of the two second transmitters 110A on the side where the perforated piezoelectric element 130 is provided (hereinafter, referred to as "the surface including the first main surface 121"), the first surface is provided. A force that contracts radially from the outer edge portion of the surface including the main surface 121 to the central portion acts.

In this way, the force of contracting from the outer edge portion toward the central portion acts on the surface including the first main surface 121. As a result, as shown in FIG. 25, the two second transmitters move so that the central portions of the two second transmitters 110A move away from each other (the direction indicated by the arrow Δ3 in FIG. 25). Each of the wave devices 110A bends.

As described above, the two second transmitters 110A are moved so that the central portions of the two second transmitters 110A move away from each other (the direction indicated by the arrow Δ3 in FIG. 25). The operation of bending the transmitter 110A of the above was described.

Using FIGS. 26 and 27, the two second transmitters move in the direction in which the central portions of the two second transmitters 110A approach each other (the direction indicated by the arrow Δ4 in FIG. 27). The operation of bending the 110A will be described. FIG. 26 shows the polarization direction P of each of the perforated piezoelectric elements 130 of the two second transmitters 110A. As shown in FIG. 26, the polarization direction P of each of the perforated piezoelectric elements 130 of the two second transmitters 110A is set in a direction away from the junction 150.

First, the potential V2 is applied to the surface on the first main surface 121 side of the perforated piezoelectric element 130, and the potential V1 is applied to the surface on the second main surface 124 side of the perforated piezoelectric element 130 (potential V1>. Let it be V2). As a result, the perforated piezoelectric element 130 extends from the central portion to the outer edge portion of the perforated piezoelectric element 130 in the direction parallel to the bottom surface (the direction indicated by the arrow α in FIG. 26). As a result, on the surface of each of the two second transmitters 110A including the first main surface 121, a force spreading from the central portion of the surface including the first main surface 121 toward the outer edge portion acts.

In this way, the force spreading from the central portion toward the outer edge portion acts on the surface including the first main surface 121. As a result, as shown in FIG. 27, the two second transmitters move in the direction in which the central portions of the two second transmitters 110A approach each other (the direction indicated by the arrow Δ4 in FIG. 27). The wave device 110A bends. At this time, the two second transmitters 110A bend to the extent that they do not come into contact with each other.

The operation of bending the two second transmitters 110A will be described above so that the central portions of the two second transmitters 110A move in the direction closer to each other (the direction indicated by the arrow Δ4 in FIG. 27). bottom.

As described above, each of the two second transmitters 110A is continuously bent in the opposite direction by alternately applying the potential V1 or the potential V2 to the upper surface and the lower surface of the perforated piezoelectric element 130.

The wave transmitting device 100A vibrates the water in the water pressure resistant container by repeating this operation, and vibrates the water pressure resistant container. Then, the wave transmitting device 100A transmits sound waves in deep water by vibrating the water pressure resistant container.

The operation of the wave transmitter 100A has been described above.

As described above, the second transmitter 110A described in the present embodiment includes the second base material portion 120A and the perforated piezoelectric element 130. The perforated piezoelectric element 130 has a through hole 131 in the central portion. Further, the second base material portion 120A holds the perforated piezoelectric element 130. The perforated piezoelectric element 130 is held on the first main surface 121 side of the second base material portion 120A.

When the second transmitter 110A is used underwater, the second transmitter 110A is deformed because the hydrostatic pressure is applied to the entire second transmitter 110A. This deformation causes the perforated piezoelectric element 130 to bend. At this time, the perforated piezoelectric element 130 is bent by stress due to hydrostatic pressure, unlike the case where it expands and contracts when a voltage is applied. Further, when the second transmitter 110A is operating, the perforated piezoelectric element 130 also bends due to the expansion and contraction of the perforated piezoelectric element 130. Therefore, when the second transmitter 110A is operating, a large tensile stress is applied to the perforated piezoelectric element 130 as compared with the case where the second transmitter 110A is not operating. Further, in general, the stress applied to the central portion of the member (bending stress) is larger than the stress applied to the outer peripheral portion of the member. Therefore, the perforated piezoelectric element 130 has a through hole 131 in the central portion. Therefore, no stress is applied to the central portion of the perforated piezoelectric element 130. As a result, the stress applied to the perforated piezoelectric element 130 can be made less likely to reach the elastic limit of the perforated piezoelectric element 130. As a result, damage to the perforated piezoelectric element 130 can be suppressed. As described above, according to the second transmitter 110A, it is possible to suppress the perforated piezoelectric element 130 from being damaged, so that the sound wave is transmitted while suppressing the output sound wave of the second transmitter 110A from decreasing. I can make waves.

Further, the second transmitter 110A described in the present embodiment does not hold the non-perforated piezoelectric element 140 on the second main surface 124 side. Therefore, the second transmitter 110A has a simpler configuration.
(Third Embodiment)
Next, the wave transmitter 100B according to the third embodiment will be described with reference to FIGS. 28 to 35. Further, in the description of the present embodiment, the same reference numerals are given to the configurations having the same configurations, connection relationships and functions as those of the wave transmitter 100 according to the first embodiment. Note that FIG. 28 is a perspective view showing the configuration of the wave transmitting device 100B.

As shown in FIG. 28, the transmitter 100B includes two third transmitters 110B and a junction 150. Here, the first wave transmitter 100 in the first embodiment and the wave transmitter 100B in the present embodiment are compared. In the description of the first transmitter 100 in the first embodiment, it is assumed that the first transmitter 100 includes two first transmitters 110. On the other hand, the transmitter 100B in the present embodiment includes two third transmitters 110B instead of the two first transmitters 110.

The configuration of the third transmitter 110B will be described with reference to FIGS. 29 to 31. FIG. 29 is an exploded perspective view of the third transmitter 110B as viewed from the first main surface 121 side. Further, FIG. 30 is an exploded perspective view of the third transmitter 110B viewed from the first main surface 121 side. FIG. 31 is a cross-sectional view of the third transmitter 110B. As shown in FIGS. 29 to 31, the third transmitter 110B includes a third base material portion 120B and two perforated piezoelectric elements 130.

Here, the third transmitter 110B is compared with the first transmitter 110 shown in FIGS. 3 to 5. In the first transmitter 110 and the third transmitter 110B, the first transmitter 110 has the non-perforated piezoelectric element 140, while the third transmitter 110B has the non-perforated piezoelectric element 140. It differs in that it has a perforated piezoelectric element 130 instead.

Further, in the first transmitter 110 and the third transmitter 110B, the first transmitter 110 has the first base material portion 120, while the third transmitter 110B is the first. The difference is that a third base material portion 120B is provided instead of the base material portion 120 of the above.

The third base material portion 120B will be described with reference to FIGS. 29 to 31. As shown in FIGS. 29 to 31, the third base material portion 120B is referred to as a first main surface 121, a first recess 122, and a protrusion 123 (hereinafter, “first protrusion 123”. ), A second main surface 124, a second recess 125, and a second protrusion 126. Here, the third base material portion 120B is compared with the first base material portion 120 shown in FIG. In the third base material portion 120B and the first base material portion 120, the first base material portion 120 does not have the second protrusion 126, while the third base material portion 120B has the second protrusion. It differs in that it has a portion 126.

The second protrusion 126 will be described. The second protrusion 126 is formed on the second main surface 124 side of the third base material portion 120B. The second protrusion 126 is inserted into the through hole 131 of the perforated piezoelectric element 130. As shown in FIG. 30, the shape of the second protrusion 126 is cylindrical, similar to the shape of the first protrusion 123.

Further, in the description of the first embodiment, it has been explained that the second main surface 124 is a surface having a circular outer circumference and inner circumference, but the second main surface 124 in the third transmitter 110B is As shown in FIG. 30, the outer circumference and the inner circumference are composed of two surfaces, a circular surface and a circular surface (the surface of the protrusion 126 described later).

The configuration of the wave transmitter 100B has been described above.

Next, the operation of the wave transmitter 100B will be described with reference to FIGS. 32 to 35. 32 to 35 are cross-sectional views for explaining the operation of the wave transmitter 100B. In this description, in order to distinguish each of the two perforated piezoelectric elements 130, the perforated piezoelectric element 130 held on the first main surface 121 side of the third base material portion 120B is referred to as a perforated piezoelectric element. It is set to 130 Ba. Further, the perforated piezoelectric element 130 held on the second main surface 124 side of the third base material portion 120B is referred to as a perforated piezoelectric element 130Bb.

Using FIGS. 32 and 33, the two third transmitters 110B move in a direction away from each other (the direction indicated by the arrow Δ5 in FIG. 33). The operation of bending the 110B will be described. FIG. 32 shows the polarization directions P of the perforated piezoelectric element 130Ba and the perforated piezoelectric element 130Bb of each of the two third transmitters 110B. As shown in FIG. 32, the polarization direction P of each of the perforated piezoelectric element 130Ba and the perforated piezoelectric element 130Bb of the two third transmitters 110B is set in a direction away from the joint portion 150.

First, the potential V1 is applied to the surface 121 side of each first main surface of the perforated piezoelectric element 130Ba, and the potential V2 is applied to the surface 124 side of each second main surface of the perforated piezoelectric element 130Ba (potential V2). V1> V2.). As a result, the perforated piezoelectric element 130Ba contracts radially from the outer edge portion to the central portion of the perforated piezoelectric element 130 in the direction parallel to the bottom surface (the direction indicated by the arrow β in FIG. 32). As a result, in each of the two third transmitters 110B, on the surface including the first main surface 121, the force of radially contracting from the outer edge portion to the central portion of the surface including the first main surface 121 is applied. It works.

Further, the potential V2 is applied to the surface 121 side of each first main surface of the perforated piezoelectric element 130Bb, and the potential V1 is applied to the surface 124 side of each second main surface of the perforated piezoelectric element 130Bb (potential V1). V1> V2.). As a result, the perforated piezoelectric element 130Bb extends radially from the central portion to the outer edge portion of the perforated piezoelectric element 130Bb in the direction parallel to the bottom surface (the direction indicated by the arrow α in FIG. 32). As a result, on the surface of each of the two third transmitters 110B including the second main surface 124, a force extending radially from the center of the surface including the second main surface 124 toward the outer edge acts. do.

In this way, the force that contracts from the outer edge toward the center acts on the surface including the first main surface 121, while the force that extends radially from the center toward the outer edge acts on the second main surface 124. Acts on the containing surface. As a result, as shown in FIG. 33, the two third transmitters move so that the central portions of the two third transmitters 110B move away from each other (the direction indicated by the arrow Δ5 in FIG. 33). Each of the wave devices 110B bends.

The operation of bending the two third transmitters 110B will be described above so that the central portions of the two third transmitters 110B move away from each other (the direction indicated by the arrow Δ5 in FIG. 33). bottom.

Using FIGS. 34 and 35, the two third transmitters move in the direction in which the central portions of the two third transmitters 110B approach each other (the direction indicated by the arrow Δ6 in FIG. 35). The operation of bending the 110B will be described. FIG. 34 shows the polarization directions P of the perforated piezoelectric element 130Ba and the perforated piezoelectric element 130Bb of each of the two third transmitters 110B. As shown in FIG. 34, the polarization direction P of each of the perforated piezoelectric element 130Ba and the perforated piezoelectric element 130Bb of the two third transmitters 110B is set in a direction away from the joint portion 150.

First, the potential V2 is applied to the surface 121 side of each first main surface of the perforated piezoelectric element 130Ba, and the potential V1 is applied to the surface 124 side of each second main surface of the perforated piezoelectric element 130Ba (potential V1). V1> V2.). As a result, the perforated piezoelectric element 130Ba extends radially from the central portion to the outer edge portion of the perforated piezoelectric element 130 in a direction parallel to the bottom surface (direction indicated by the arrow α in FIG. 34). As a result, in each of the two third transmitters 110B, on the surface including the first main surface 121, a force extending radially from the central portion of the surface including the first main surface 121 toward the outer edge portion is applied. It works.

Further, the potential V1 is applied to the surface 121 side of each first main surface of the perforated piezoelectric element 130Bb, and the potential V2 is applied to the surface 124 side of each second main surface of the perforated piezoelectric element 130Bb (potential V2). V1> V2.). As a result, the perforated piezoelectric element 130Bb contracts radially from the outer edge portion to the central portion of the perforated piezoelectric element 130Bb in the direction parallel to the bottom surface (the direction indicated by the arrow β in FIG. 34). As a result, on the surface of each of the two third transmitters 110B including the second main surface 124, a force that radially contracts from the outer edge portion of the surface including the second main surface 124 toward the central portion acts. do.

In this way, the force spreading from the central portion toward the outer edge portion acts on the surface including the first main surface 121, while the force contracting from the outer edge portion toward the central portion acts on the surface including the second main surface 124. Acts on. As a result, as shown in FIG. 35, the two third transmitters move in the direction in which the central portions of the two third transmitters 110B approach each other (the direction indicated by the arrow Δ6 in FIG. 35). The wave device 110B bends. At this time, the two third transmitters 110B bend to the extent that they do not come into contact with each other.

The operation of bending the two third transmitters 110B has been described above so that the central portions of the two third transmitters 110B move in the directions closer to each other (the direction indicated by the arrow Δ6 in FIG. 35). ..

As described above, each of the two third transmitters 110B is continuously bent in the opposite direction by alternately applying the potential V1 or the potential V2 to the upper surface and the lower surface of the perforated piezoelectric elements 130Ba and 130Bb. .. Specifically, the two third transmitters 110B bend so that the central portions of the two third transmitters 110B move away from each other (the direction indicated by the arrow Δ5 in FIG. 33). Further, the two third transmitters 110B bend so that the central portions of the two third transmitters 110B move in the direction in which the central portions thereof approach each other (the direction indicated by the arrow Δ6 in FIG. 35).

The wave transmitting device 100B vibrates the water in the water pressure resistant container by repeating this operation, and vibrates the water pressure resistant container. Then, the wave transmitting device 100B transmits sound waves in deep water by vibrating the water pressure resistant container.

The operation of the wave transmitter 100B has been described above.

As described above, the third transmitter 110B described in the present embodiment includes the third base material portion 120B and the two perforated piezoelectric elements 130. Each of the two perforated piezoelectric elements 130 has a through hole 131 in the center. Further, the second base material portion 120A holds two perforated piezoelectric elements 130. One of the perforated piezoelectric elements 130 is held on the first main surface 121 side of the second base material portion 120A. The other perforated piezoelectric element 130 is arranged on the second main surface 124 side of the second base material portion 120A.

When the second transmitter 110A is used underwater, the second transmitter 110A is deformed because the hydrostatic pressure is applied to the entire second transmitter 110A. This deformation causes the two perforated piezoelectric elements 130 to bend. At this time, the two perforated piezoelectric elements 130 are bent by stress due to hydrostatic pressure, unlike the case where they expand and contract when a voltage is applied. Further, when the second transmitter 110A is operating, the two perforated piezoelectric elements 130 are also bent by the expansion and contraction of each perforated piezoelectric element 130. Therefore, when the second transmitter 110A is operating, a large tensile stress is applied to the two perforated piezoelectric elements 130 as compared with the case where the second transmitter 110A is not operating. Further, in general, the stress applied to the central portion of the member (bending stress) is larger than the stress applied to the outer peripheral portion of the member. Therefore, the two perforated piezoelectric elements 130 have a through hole 131 in the central portion. Therefore, no stress is applied to each central portion of the two perforated piezoelectric elements 130. As a result, the stress applied to the two perforated piezoelectric elements 130 can be made less likely to reach the elastic limit of each perforated piezoelectric element 130. As a result, damage to the two perforated piezoelectric elements 130 can be suppressed. In this way, according to the second transmitter 110A, it is possible to prevent the two perforated piezoelectric elements 130 from being damaged, so that the sound wave can be suppressed while suppressing the decrease in the output sound wave of the second transmitter 110A. Can be transmitted.

Further, when the third transmitter 110B is used underwater, a hydrostatic pressure is applied to the entire third transmitter 110B, so that the first main surface 121 of the third transmitter 110B has a surface 121. The central portion is deformed so as to protrude from the outer peripheral portion. On the other hand, the second main surface 124 of the third transmitter 110B is deformed so that the central portion is recessed with respect to the outer peripheral portion. Due to this deformation, the perforated piezoelectric element 130 on the second main surface 124 side is bent. Further, when the third transmitter 110B is operating, the perforated piezoelectric element 130 on the second main surface 124 side is also bent by the expansion and contraction of the two perforated piezoelectric elements 130. Therefore, when the third transmitter 110B is operating, a large compressive stress is applied to the perforated piezoelectric element 130 as compared with the case where the third transmitter 110B is not operating. Further, in general, the stress applied to the central portion of the member (bending stress) is larger than the stress applied to the outer peripheral portion of the member. Therefore, the perforated piezoelectric element 130 has a through hole 131 in the central portion. Therefore, no compressive stress is applied to the central portion of the perforated piezoelectric element 130 on the second main surface 124 side. As a result, the compressive stress applied to the perforated piezoelectric element 130 can be made less likely to reach the elastic limit of the perforated piezoelectric element 130. As a result, damage to the perforated piezoelectric element 130 can be suppressed. In this way, according to the transmitter 110, it is possible to prevent the perforated piezoelectric element 130 from being damaged, so that sound waves can be continuously transmitted.

Further, the third transmitter 110B described in the present embodiment includes a perforated piezoelectric element 130 on the first main surface 121 side and the second main surface 124 side. As a result, the third transmitter 110B described in the present embodiment is provided with the perforated piezoelectric element 130 only on either the first main surface 121 side or the second main surface 124 side. Compared with, it is possible to output a large sound wave.

Further, each of the two perforated piezoelectric elements 130 included in the third transmitter 110B described in the present embodiment has the same shape as each other. Therefore, in the third transmitter 110B described in the present embodiment, the types of parts can be reduced as compared with the case where the shapes of the two piezoelectric elements are different.
(Fourth Embodiment)
Next, the fourth embodiment will be described with reference to FIGS. 21 to 23. The fourth embodiment is a mode in which the second transmitter 110A shown in FIGS. 21 to 23 is used alone.

The configuration of the second transmitter 110A in the present embodiment is equivalent to that of the second transmitter 110A according to the second embodiment. Specifically, the second transmitter 110A in the present embodiment includes a second base material portion 120A and a perforated piezoelectric element 130. Further, the perforated piezoelectric element 130 has a through hole 131 in the central portion. Further, the perforated piezoelectric element 130 is held on the first main surface 121 side of the second base material portion 120.

On the other hand, each configuration of the second transmitter 110A in the present embodiment does not have to have the shape shown in FIGS. 21 to 23. For example, the shape of the perforated piezoelectric element 130 may be a prism whose bottom surface is an elliptical outer circumference and inner circumference. Further, for example, the first main surface 121 of the second base material portion 120A may be a surface having an elliptical outer circumference and inner circumference.

Next, the operation of the second transmitter 110A in the fourth embodiment will be described. The operation of the second transmitter 110A in the fourth embodiment is equivalent to the operation of the second transmitter 110A in the second embodiment. Specifically, the second transmitter 110A in the fourth embodiment flexes continuously in the opposite direction by alternately applying the potential V1 or the potential V2 to the upper surface and the lower surface of the perforated piezoelectric element 130. nothing.

As described above, the second transmitter 110A described in the present embodiment includes the second base material portion 120A and the perforated piezoelectric element 130. The perforated piezoelectric element 130 has a through hole 131 in the central portion. Further, the second base material portion 120A holds the perforated piezoelectric element 130. The perforated piezoelectric element 130 is held on the first main surface 121 side of the second base material portion 120A.

When the second transmitter 110A is used underwater, hydrostatic pressure is applied to the entire second transmitter 110A. At this time, the second transmitter 110A is deformed so that the central portion of the first main surface 121 protrudes with respect to the outer peripheral portion, and the central portion of the first main surface 121 is on the outer peripheral portion. On the other hand, it may be deformed to be dented.

A case where the second transmitter 110A is deformed so that the central portion of the first main surface 121 protrudes from the outer peripheral portion will be described. The deformation in this case causes the perforated piezoelectric element 130 to bend. Further, when the second transmitter 110A is operating, the perforated piezoelectric element 130 also bends due to the expansion and contraction of the perforated piezoelectric element 130. Therefore, when the second transmitter 110A is operating, a large tensile stress is applied to the perforated piezoelectric element 130 as compared with the case where the second transmitter 110A is not operating. Further, in general, the stress applied to the central portion of the member (bending stress) is larger than the stress applied to the outer peripheral portion of the member. Therefore, the perforated piezoelectric element 130 has a through hole 131 in the central portion. Therefore, no tensile stress is applied to the central portion of the perforated piezoelectric element 130. As a result, the tensile stress applied to the perforated piezoelectric element 130 can be made less likely to reach the elastic limit of the perforated piezoelectric element 130. As a result, damage to the perforated piezoelectric element 130 can be suppressed. As described above, according to the second transmitter 110A, it is possible to prevent the perforated piezoelectric element 130 from being damaged, so that sound waves can be continuously transmitted.

Next, a case where the second transmitter 110A is deformed so that the central portion of the first main surface 121 is recessed with respect to the outer peripheral portion will be described. The deformation in this case causes the perforated piezoelectric element 130 on the second main surface 124 side to bend. Further, when the second transmitter 110A is operating, the perforated piezoelectric element 130 on the second main surface 124 side is also bent by the expansion and contraction of the two perforated piezoelectric elements 130. Therefore, when the second transmitter 110A is operating, a large compressive stress is applied to the perforated piezoelectric element 130 as compared with the case where the second transmitter 110A is not operating. Further, in general, the stress applied to the central portion of the member (bending stress) is larger than the stress applied to the outer peripheral portion of the member. Therefore, the perforated piezoelectric element 130 has a through hole 131 in the central portion. Therefore, no compressive stress is applied to the central portion of the perforated piezoelectric element 130. As a result, the compressive stress applied to the perforated piezoelectric element 130 can be made less likely to reach the elastic limit of the perforated piezoelectric element 130. As a result, damage to the perforated piezoelectric element 130 can be suppressed. As described above, according to the second transmitter 110A, it is possible to prevent the perforated piezoelectric element 130 from being damaged, so that sound waves can be continuously transmitted. The fourth embodiment has been described above.

As described above, it has been described that the wave transmitter 100 in the first embodiment is composed of two first transmitters 110 and a joint portion 150. Further, it is assumed that the transmitter 100A in the second embodiment is composed of two second transmitters 110A and a joint portion 150. Further, it is assumed that the transmitter 100B in the third embodiment is composed of two third transmitters 110B and a joint portion 150.

However, the present invention is not limited to the above example, and the first transmitter 110, the second transmitter 110A, and the joint portion 150 may be combined. Further, the first transmitter 110, the third transmitter 110B and the joint portion 150 may be combined. Further, the second transmitter 110A, the third transmitter 110B and the joint portion 150 may be combined.

Further, as described above, in the fourth embodiment, the second transmitter 110A is used alone. However, the present invention is not limited to this, and the first transmitter 110 or the third transmitter 110B may be used alone.

Although the invention of the present application has been described above with reference to the embodiment, the invention of the present application is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made within the scope of the present invention in terms of the structure and details of the present invention.

100, 100', 100A, 100B transmitter 110, 110', 110a, 110b transmitter, first transmitter 120, 120', 120a, 120b base material, first base material 121, 121 ′, 121a, 121b First main surfaces 122, 122 ′ First recesses 123, 123 ′ Projections 124, 124 ′, 124a, 124b Second main surfaces 125, 125 ′ Second recesses 130, 130 ′, 130a, 130b Perforated piezoelectric element 131, 131'Through hole 140, 140', 140a, 140b Non-perforated piezoelectric element 150 Joint 110A Second transmitter 120A Second base material 110B Third transmitter 120B Third base material 126 Second protrusions 130Ba, 130Bb Perforated piezoelectric element

Claims (5)

A perforated piezoelectric element with a through hole in the center,
A base material portion that holds the perforated piezoelectric element and joins with the side surface of the outer peripheral portion of the perforated piezoelectric element.
With
The perforated piezoelectric element is held on the first main surface side of the base material portion, and is held.
A transmitter in which a non-perforated piezoelectric element having no through hole is further held on a second main surface side opposite to the first main surface side of the base material portion. Further provided with a protrusion formed on the base material portion,
The transmitter according to claim 1, wherein the perforated piezoelectric element has the through hole attached to the protrusion and is held on the base material. With at least two transmitters,
Each of the two transmitters is composed of the transmitter according to claim 1 or 2.
Each of the two transmitters is a wave transmitter provided so as to face each other through a gap. The base material portion of each of the two transmitters is arranged so that the first main surface of each of the two transmitters faces each other.
The wave transmitting device according to claim 3 , wherein the perforated piezoelectric element is composed of a member whose elastic limit for compressive stress is larger than the elastic limit for tensile stress. The transmitter according to claim 3 or 4 , further comprising a joint for joining the two transmitters so that the two transmitters face each other through a gap.

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