JP2007315788A - Underwater ultrasonic utilization apparatus, ship with same, and ultrasonic transducer used for same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ship with an underwater ultrasonic utilization apparatus having satisfactory radiation intensity, reception sensitivity, and directional characteristics of ultrasonic waves to be radiated into the water from the ship provided with the underwater ultrasonic utilization apparatus including an ultrasonic transducer mounted to an inboard side surface etc. of the ship's bottom. <P>SOLUTION: In a boat 10 with a fish finder, the ultrasonic utilization apparatus 6 is fastened to a metal bottom part 3 of a boat 1. The ultrasonic utilization apparatus 6 includes both a piezoelectric element 61 which oscillates in thickness directions when driven and a disc-like aluminum matching body 62 overlayed on the piezoelectric element 61 via a buffer body 63 to be in contact with the inboard side surface 3B and satisfies 1/2-1/10≤tb/λb+ts/λs≤1/2+1/10 (wherein, the wavelength of ultrasonic oscillations transmitted through the metal bottom part is λb; the thickness of the metal bottom part is tb; the wavelength of ultrasonic oscillations transmitted through the aluminum matching body 62 is λs; and the thickness of the wavelength matching body is ts). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ship with an underwater ultrasonic device, an underwater ultrasonic device, and an ultrasonic transducer used therefor, including an underwater ultrasonic device such as a fish finder or an underwater ultrasonic exploration device.

  Conventionally, underwater ultrasonic waves are used in underwater ultrasonic devices such as fish finders and underwater ultrasonic exploration devices. In such an underwater ultrasonic device, when an ultrasonic transducer that emits ultrasonic waves is attached to a ship or a case, it is fixed to the outside of the ship or the case by using a member or by drilling a through hole in the bottom of the ship. The method of making it known is known. In addition, an inner hull method, a method of adhering an ultrasonic transducer to the inner surface of the ship bottom or the inner surface of the case is also employed.

  Among these, the method of bonding the ultrasonic transducer to the inner surface of the ship's bottom and the inner surface of the case does not take the ultrasonic transducer out of the ship (outside), so it is less susceptible to air bubbles when the ship is running. There are advantages such as being less prone to failure due to collision with rocks and other obstacles.

  However, the method of adhering an ultrasonic transducer to the inner surface of the ship's bottom or the case's inner surface emits ultrasonic waves into the water through the vessel's bottom or case, so there are many losses and the same ultrasonic transducer is immersed directly in the water. In comparison with the case of using the ultrasonic wave, the intensity of the ultrasonic wave radiated into the water is lowered, and the reception sensitivity of the ultrasonic wave is also lowered. Further, the strength of the side lobe tends to increase, and the directivity angle of the main beam also tends to increase.

  The present invention has been made in view of such problems, and in a ship equipped with an underwater ultrasonic device including an ultrasonic transducer attached to an inner surface of a ship bottom or the like, emission of ultrasonic waves radiated into water It is an object of the present invention to provide a ship with an underwater ultrasonic device having good strength, received wave sensitivity, and directivity. In addition, in an underwater ultrasonic device that attaches an ultrasonic transducer to a ship or a case, an underwater ultrasonic device that has excellent radiation intensity, received sensitivity, and directivity of ultrasonic waves radiated into the water is provided. With the goal. Furthermore, it aims at providing the ultrasonic transducer | vibrator used for this underwater ultrasonic wave utilization apparatus.

The solution includes an underwater ultrasonic device including an underwater ultrasonic device including an ultrasonic transducer attached to an inner surface of the metal ship bottom, wherein at least a part of the ship bottom is made of metal. The ultrasonic transducer is a vibration element that ultrasonically vibrates in a predetermined vibration direction at a predetermined frequency, and a wavelength matching body that has the predetermined vibration direction as a thickness direction. A wavelength matching body that is directly or indirectly stacked in a predetermined vibration direction, is in contact with the inner surface of the ship and performs wavelength matching, and has a wavelength of the ultrasonic vibration of the predetermined frequency transmitted through the metal ship bottom, λb, When the thickness of the bottom portion is tb, the wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the wavelength matching body is λs, and the thickness of the wavelength matching body is ts, the following formula (1) is satisfied. 1 / -1 / 10 ≦ tb / λb + ts / λs ≦ 1/2 + 1/10 ... formula (1)
A ship with an underwater ultrasonic device.

  The ship with an underwater ultrasonic device according to the present invention includes a wavelength matching body having a predetermined vibration direction of the vibration element as a thickness direction, and the metal ship bottom and the wavelength matching body have a relationship satisfying Expression (1). Specifically, the thickness tb of the metal ship bottom and the thickness ts of the wavelength matching body are adjusted to tb / λb + ts / λs = 1/2 or a range sufficiently close to this (within ± 1/10). . In other words, when the metal ship bottom and the wavelength matching body are viewed in the thickness direction, the ultrasonic vibrations generated in them are set to be approximately ½ wavelength of the ultrasonic vibrations. For this reason, while disposing the ultrasonic transducer in the ship, loss and unnecessary reflection can be suppressed, and the ultrasonic wave can be efficiently emitted from the bottom of the metal ship to the outside (underwater). In addition, ultrasonic waves incident from underwater can be efficiently transmitted to the vibration element. In addition, the directivity is good and the occurrence of side lobes can be suppressed. Thus, it is possible to provide a ship with an underwater ultrasonic wave utilization device having good ultrasonic radiation characteristics and reception characteristics.

In addition, underwater ultrasonic equipment radiates ultrasonic waves into the water, such as a fish detector that detects the presence or absence of underwater fish, and an underwater ultrasonic probe that searches for the shape and depth of the bottom of the seabed or lake. In addition to receiving ultrasonic waves from underwater, or receiving ultrasonic waves from underwater and receiving ultrasonic waves from underwater to acquire underwater or bottom information, Includes devices that use ultrasound in water, such as underwater communications.
In addition, as a ship body used for a ship with an underwater ultrasonic device, any ship can be used as long as at least a part of the ship bottom is a metal ship bottom and an ultrasonic vibrator can be attached to the metal ship bottom. A ship made entirely of metal, or a ship made entirely of metal, such as an aluminum ship, can also be used.

Furthermore, the material of the metal forming the ship bottom metal portion may be appropriately selected according to the use of the ship, and it is preferable to select a metal that can transmit ultrasonic waves with low loss. For example, aluminum alloys, such as aluminum and duralumin, are mentioned. Moreover, steels, such as carbon steel and stainless steel, a titanium alloy, etc. are mentioned.
As the vibration element, any vibration element that can appropriately excite ultrasonic waves radiated into water can be used. For example, a vibration element that can generate ultrasonic vibration of a predetermined frequency by electrical driving, such as a piezoelectric element, an electrostrictive element, and a magnetostrictive element, can be used. In addition, when using a piezoelectric element, use a piezoelectric element made of a disk-shaped or square-plate-shaped piezoelectric ceramic polarized in the thickness direction, or a bolted Langevin type vibration element using a ring-shaped piezoelectric element. You can also.

The wavelength matching body has a thickness that satisfies the above-described formula (1) or formula (2) described later. As this wavelength matching body, for example, a plate-like metal plate interposed between the vibration element and the metal bottom portion of the ship bottom or the metal water contact portion of the case can be used.
Further, it is preferable that the wavelength matching body and the metal ship bottom part or the metal water contact part are joined to each other without any gap by an adhesive. In addition, it is preferable that the surface (adhesion surface) of the wavelength matching body on the metal ship bottom side is flattened by lapping or the like. Similarly, at least a portion to be joined to the wavelength matching body among the inner side surface of the metal ship bottom and the inner side surface of the metal water contact portion may be subjected to appropriate leveling such as lapping or leveling with sandpaper. .

  Furthermore, in the above-mentioned ship with an underwater ultrasonic device, the metal ship bottom is made of aluminum or an aluminum alloy, and the wavelength matching body is also preferably a ship with an underwater ultrasonic device made of aluminum or an aluminum alloy.

  Some ships such as pleasure boats have their bottoms and hulls made of aluminum (or an alloy thereof) such as aluminum die cast. When the bottom of the metal ship is made of aluminum (or an alloy thereof) like these, the wavelength matching body is also made of the same aluminum (or an alloy thereof), so that the acoustic impedance and the like become similar values. Ultrasonic reflection at the interface can be further suppressed.

  Furthermore, it is a ship with the underwater ultrasonic wave utilization apparatus in any one of the above-mentioned, Comprising: The said ultrasonic transducer | vibrator is equipped with the buffer body which consists of rubber | gum between the said vibration element and a wavelength matching body, The underwater ultrasonic utilization apparatus It should be a ship with a ship.

In an ultrasonic vibrator having a structure in which the vibration element is directly bonded to the wavelength matching body, adhesion peeling may occur at the interface between the two.
On the other hand, in the ship with an underwater ultrasonic device according to the present invention, an ultrasonic transducer in which mechanical coupling between the vibration element and the wavelength matching body is relaxed by using a buffer body is used. This prevents the vibration element bonded to the buffer body from being peeled off by the vibration of the vibration element, and can provide a ship with a more reliable underwater ultrasonic device.

As the buffer body, it is preferable to select a material that can moderately relax the mechanical coupling between the vibration element and the wavelength matching body. Specifically, a rubber-like elastic body having an appropriate hardness can be used. More specifically, rubber materials such as CR rubber and NBR rubber, and an epoxy resin having rubber-like elasticity can be used.
In order to electrically insulate the vibration element from the wavelength matching body, it is preferable to use an insulating material such as an insulating rubber as the buffer body.

Another solution is an underwater ultrasonic device for use in a ship in which at least a part of the ship bottom is a metal ship bottom made of metal, and is intended to be attached to the inner surface of the metal ship bottom. The ultrasonic vibrator includes a vibration element that ultrasonically vibrates in a predetermined vibration direction at a predetermined frequency, and a wavelength matching body that has the predetermined vibration direction as a thickness direction, and the vibration element is the above-described vibration element. A wavelength matching body that is directly or indirectly stacked in a predetermined vibration direction, is in contact with the inner surface of the ship and performs wavelength matching, and the wavelength matching body has a wavelength of ultrasonic vibration of the predetermined frequency that is transmitted through the metal ship bottom. Is λb, the thickness of the bottom of the metal ship is tb, the wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the wavelength matching body is λs, and the thickness of the wavelength matching body is ts, Meet the thickness ts 1 / 2-1 / 10 ≦ tb / λb + ts / λs ≦ 1/2 + 1/10 (1)
It is an underwater ultrasonic device.

  In the underwater ultrasonic device of the present invention, the ultrasonic vibrator includes a wavelength matching body whose thickness direction is a predetermined vibration direction of the vibration element, and the thickness ts of the wavelength matching body and the ultrasonic vibrator The thickness tb of the metal ship bottom portion of the ship bottom to which is attached is a relationship satisfying the formula (1). Specifically, the thickness tb of the metal ship bottom and the thickness ts of the wavelength matching body are adjusted to tb / λb + ts / λs = 1/2 or a range sufficiently close to this (within ± 1/10). . In other words, when the metal ship bottom and the wavelength matching body are viewed in the thickness direction, the ultrasonic vibrations generated in these parts are combined so that the thickness thereof is approximately ½ wavelength of the ultrasonic vibrations. For this reason, by attaching an ultrasonic transducer to the bottom of a metal ship, while placing this ultrasonic transducer in the ship, it suppresses losses and unnecessary reflections, and efficiently sends ultrasonic waves from the metal ship bottom to the outboard (underwater ) Can be emitted. Further, it is possible to efficiently transmit ultrasonic waves incident from underwater to the vibration element. In addition, the directivity is good and the occurrence of side lobes can be suppressed. Thus, by using the underwater ultrasonic device of the present invention, it is possible to configure a ship with an underwater ultrasonic device having good ultrasonic radiation characteristics and receiving characteristics.

Still another solution is an underwater ultrasonic device including an ultrasonic transducer and a case surrounding at least the ultrasonic transducer, wherein the water contact portion of the case that contacts water during use At least a part is a metal water contact portion made of metal, and the ultrasonic vibrator is attached to an inner surface of the metal water contact portion, and a vibration element that ultrasonically vibrates in a predetermined vibration direction at a predetermined frequency. A wavelength matching body having the predetermined vibration direction as a thickness direction, wherein the vibration element is directly or indirectly stacked in the predetermined vibration direction, is in contact with the inner surface, and performs wavelength matching; The wavelength matching body has a wavelength of ultrasonic vibration of the predetermined frequency transmitted through the metal wetted part λc, a thickness of a part of the metal wetted part through which the ultrasonic vibration is transmitted is tc, and the wavelength The above-mentioned place through the matching body When the wavelength of the ultrasonic vibration at the frequency is λs and the thickness of the wavelength matching body is ts, the thickness ts satisfies the following formula (2): 1 / 2-1 / 10 ≦ tc / λc + ts / λs ≦ 1 / 2 + 1/10 ... Formula (2)
It is an underwater ultrasonic device.

  In the underwater ultrasonic wave using apparatus of the present invention, the ultrasonic transducer is surrounded by the case. This ultrasonic vibrator includes a wavelength matching body whose thickness direction is a predetermined vibration direction of the vibration element, and further, a thickness ts of the wavelength matching body and a metal water contact portion of a case to which the ultrasonic vibrator is attached. Of these, the thickness tc of the portion where the ultrasonic vibration is transmitted has the above relationship satisfying the expression (2). Specifically, the thickness tc of the metal wetted part and the thickness ts of the wavelength matching body are adjusted to tc / λc + ts / λs = 1/2 or a range sufficiently close to this (within ± 1/10). Yes. In other words, when the metal water contact portion and the wavelength matching body are viewed in the thickness direction, the ultrasonic vibration generated in the metal water contact portion and the wavelength matching body is approximately ½ wavelength of the ultrasonic vibration. For this reason, by attaching the ultrasonic vibrator to the metal wetted part, the ultrasonic vibrator is efficiently sent from the metal wetted part to the water while suppressing the loss and unnecessary reflection while arranging the ultrasonic vibrator in the case. To be able to radiate. Further, it is possible to efficiently transmit ultrasonic waves incident from underwater to the vibration element. In addition, the directivity is good and the occurrence of side lobes can be suppressed. In this way, it is possible to provide an underwater ultrasonic device having good ultrasonic radiation characteristics and reception characteristics.

In addition to the case where the ultrasonic transducer is sealed and sealed as a waterproof structure, this underwater ultrasonic equipment case is not waterproof because the upper part, such as a boat or saddle, is open. Can also be adopted.
Further, the material of the metal forming the metal water contact portion may be appropriately selected according to the use of the underwater ultrasonic device, and it is preferable to select a metal capable of transmitting ultrasonic waves with low loss. For example, aluminum alloys, such as aluminum and duralumin, are mentioned. Moreover, steels, such as carbon steel and stainless steel, a titanium alloy, etc. are mentioned.

  Further, in any of the above-described underwater ultrasonic wave utilization devices, the ultrasonic transducer is an underwater ultrasonic wave utilization device including a buffer body made of rubber between the vibration element and a wavelength matching body. Is preferred.

In an ultrasonic vibrator having a structure in which the vibration element is directly bonded to the wavelength matching body, adhesion peeling may occur at the interface between the two.
On the other hand, the underwater ultrasonic device of the present invention uses an ultrasonic transducer in which the mechanical coupling between the vibration element and the wavelength matching body is relaxed by the buffer body. This prevents a problem that the vibration element bonded to the buffer body is peeled off by the vibration of the vibration element, so that a more reliable underwater ultrasonic device can be obtained.

Still another solution is an ultrasonic transducer that is scheduled to be attached to the inner surface of the metal ship bottom in a ship in which at least a part of the ship bottom is a metal ship bottom made of metal, and has a predetermined frequency. A vibration element that ultrasonically vibrates in a predetermined vibration direction and a wavelength matching body having the predetermined vibration direction as a thickness direction, wherein the vibration element is stacked directly or indirectly in the predetermined vibration direction, A wavelength matching body that performs wavelength matching, wherein the wavelength matching body has a wavelength of the ultrasonic vibration of the predetermined frequency transmitted through the metal ship bottom, λb, a thickness of the metal ship bottom tb, When the wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the wavelength matching body is λs and the thickness of the wavelength matching body is ts, it has a thickness ts satisfying the following formula (1) 1 / 2-1 / 10 ≦ tb / λb + t s / λs ≦ 1/2 + 1/10 (1)
It is an ultrasonic transducer.

  In the ultrasonic transducer of the present invention, the wavelength matching body has a relationship satisfying the formula (1) with respect to the metal bottom portion of the ship bottom where the ultrasonic transducer is scheduled to be attached. Specifically, the thickness tb of the metal ship bottom and the thickness ts of the wavelength matching body are adjusted to tb / λb + ts / λs = 1/2 or a range sufficiently close to this (within ± 1/10). . In other words, when the metal ship bottom and the wavelength matching body are viewed in the thickness direction, the ultrasonic vibrations generated in these are combined to be approximately ½ wavelength of the ultrasonic vibrations. For this reason, by attaching this ultrasonic transducer to the bottom of the metal ship, while placing this ultrasonic transducer inside the ship, it suppresses losses and unnecessary reflections, and efficiently transmits ultrasonic waves from the metal ship bottom to the outboard ( It becomes possible to radiate underwater. Further, it is possible to efficiently transmit ultrasonic waves incident from underwater to the vibration element. In addition, the directivity is good and the occurrence of side lobes can be suppressed. Thus, it is possible to configure a ship equipped with an ultrasonic transducer having excellent ultrasonic radiation characteristics and reception characteristics.

Still another solution is planned to be attached to the inner surface of the metal water contact portion of the case where at least a part of the water contact portion in contact with water is a metal water contact portion made of metal. An ultrasonic transducer surrounded by the case, a vibration element that ultrasonically vibrates in a predetermined vibration direction at a predetermined frequency, and a wavelength matching body having the predetermined vibration direction as a thickness direction, The vibration element includes a wavelength matching body that is directly or indirectly stacked in the predetermined vibration direction, is in contact with the inner side surface, and performs wavelength matching, and the wavelength matching body transmits the predetermined frequency transmitted through the metal water contact portion. Λc is the wavelength of the ultrasonic vibration of the metal, tc is the thickness of the portion where the ultrasonic vibration is transmitted in the metal water contact portion, λs is the wavelength of the ultrasonic vibration of the predetermined frequency transmitted through the wavelength matching body, and this wavelength matching Let ts be the body thickness Having a thickness ts satisfying the following formula (2) 1 / 2-1 / 10 ≦ tc / λc + ts / λs ≦ 1/2 + 1/10 (2)
It is an ultrasonic transducer.

  In the ultrasonic transducer of the present invention, the wavelength matching body has a relationship satisfying the formula (2) with respect to the metal water contact portion of the case where the ultrasonic transducer is scheduled to be attached. Specifically, the thickness tc of the portion where the ultrasonic vibration is transmitted in the metal water contact portion and the thickness ts of the wavelength matching body are tc / λc + ts / λs = 1/2 or a range sufficiently close to this (± 1 / 10)). In other words, when the metal water contact portion and the wavelength matching body are viewed in the thickness direction, the ultrasonic vibration generated in the metal water contact portion and the wavelength matching body is approximately ½ wavelength of the ultrasonic vibration. For this reason, by attaching this ultrasonic vibrator to the metal water contact part, while disposing this ultrasonic vibrator in the case, it suppresses loss and unnecessary reflection, and efficiently transmits ultrasonic waves from the metal water contact part. It becomes possible to radiate into the water. Further, it is possible to efficiently transmit ultrasonic waves incident from underwater to the vibration element. In addition, the directivity is good and the occurrence of side lobes can be suppressed. Thus, it is possible to configure an underwater ultrasonic wave utilization apparatus including an ultrasonic transducer having good ultrasonic radiation characteristics and reception characteristics.

  Furthermore, it is preferable that the ultrasonic vibrator according to any one of the above is provided with a buffer body made of rubber between the vibration element and the wavelength matching body.

In an ultrasonic vibrator having a structure in which the vibration element is directly bonded to the wavelength matching body, adhesion peeling may occur at the interface between the two.
On the other hand, in the ultrasonic transducer of the present invention, the mechanical coupling between the vibration element and the wavelength matching body is relaxed by the buffer body. This prevents a problem that the vibration element bonded to the buffer body is peeled off by the vibration of the vibration element, so that a more reliable underwater ultrasonic device can be obtained.

  Embodiments of the present invention will be described as first and second embodiments with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS. The boat 10 with a fish finder of the first embodiment includes a boat 1 and a fish finder 4 mounted on the boat 1. Of these, the boat 1 is a so-called aluminum ship, and the entire hull including the metal ship bottom part 3 which is a part of the ship bottom 2 is made of an aluminum alloy. The bottom 2 (metal bottom 3) is located below the water surface WS when the boat 1 is floated on the water.

  A fish detector 4 is mounted in the boat 1. The fish finder 4 includes an ultrasonic transducer 6 and a main body device 5 that drives the ultrasonic transducer 6 and analyzes the output (ultrasonic wave reception output) to display an underwater state, the presence / absence of a school of fish, and the like. It is out. The main unit 5 includes a drive power source 51 for driving the ultrasonic transducer 6 and a display 52 for displaying an image or data processed from the output from the ultrasonic transducer 6.

  On the other hand, as shown in FIG. 2, the ultrasonic transducer 6 is fixed to the inboard side surface 3 </ b> B of the metal ship bottom 3 that is a part of the ship bottom 2. The thickness tb of the metal ship bottom 3 at the portion where the ultrasonic transducer 6 is fixed is tb = 6.0 mm, and the sound velocity vb in the thickness direction is vb = 6400 m / s. The ultrasonic transducer 6 is disposed in a disk-shaped (φ40 × t10 mm) piezoelectric element 61 and a front surface 61F side of the piezoelectric element 61 and has a larger diameter than the piezoelectric element 61 and a substantially disk-shaped (φ80 × 20 mm). And a buffer body 63 having a disk shape (φ40 × t5.0 mm) having substantially the same diameter as that of the piezoelectric element 61. The buffer body 63 is interposed between the piezoelectric element 61 and the aluminum matching body 62.

  Among them, the piezoelectric element 61 is mainly composed of lead zirconate titanate, polarized in the thickness direction (vertical direction in FIG. 2, direction along the axis AX), and an electrode made of Ag on the front surface 61F and the back surface 61B. 61E1 and 61E2 are respectively formed. These electrodes 61E1 and 61E2 are connected to the main body device 5 via lead wires (not shown) in the cable 66, and the piezoelectric element 61 is driven by the drive circuit 51 at a predetermined drive frequency f (= 120 kHz). , Expansion and contraction (ultrasonic vibration) in the thickness direction (axis AX direction).

The aluminum alignment body 62 is made of the same aluminum alloy as that of the metal ship bottom 3, and as described above, the thickness (dimension in the axis AX direction) ts is ts = 20 mm. The sound velocity vs in the thickness direction of the aluminum matching body 62 is vs = 6400 m / s. The aluminum alignment body 62 is in close contact with the inner surface 3B of the metal bottom 3 of the boat 1 via the adhesive layer AD at the front surface 62F. The aluminum matching body 62 ultrasonically vibrates in the thickness direction (axis AX direction) by the ultrasonic vibration of the piezoelectric element 61, and transmits this to the metal ship bottom 3.
The function of the aluminum alignment body 62 will be described later.
In addition, since the aluminum matching body 62 and the metal ship bottom 3 are made of the same material, the acoustic impedances of the two are almost equal, and reflection at the interface between the two is less likely to occur. Further, the front surface 62F of the aluminum matching body 62 is preferably leveled by lapping or the like so as to be in close contact with the inboard side surface 3B of the metal ship bottom 3. Similarly, the inboard side surface 3B of the metal ship bottom 3 is preferably leveled by sandpaper or lapping.

  The buffer body 63 is made of insulating CR rubber, and is sandwiched between the front surface 61F of the piezoelectric element 61 and the back surface 62B of the aluminum matching body 62. Specifically, the piezoelectric element 61, the buffer body 63, and the aluminum matching body 62 are joined together by an adhesive (not shown). The buffer body 63 is interposed between the piezoelectric element 61 and the aluminum matching body 62 to relax the mechanical coupling between them. This is because, when the piezoelectric element 61 and the aluminum matching body 62 are directly joined without the buffer body 63, vibration in the thickness direction of the piezoelectric element 61 (stretching in the thickness direction) and accompanying radial vibration (in the radial direction). In contrast, since the mode of ultrasonic vibration excited by the aluminum matching body 62 is not completely the same, there is a risk of “adhesion peeling” in which a joint portion (adhesive) between the two cracks. Therefore, the buffer body 63 made of rubber is interposed, so that the ultrasonic vibration generated by the piezoelectric element 61 is transmitted to the aluminum matching body 62 and the difference in vibration between the two is absorbed.

  Thus, when the drive circuit 51 drives the piezoelectric element 61, the piezoelectric element 61 expands and contracts (ultrasonic vibration) in the thickness direction (axis AX direction) at the vibration frequency f, and passes through the buffer body 63 and the aluminum matching body 62. The ultrasonic wave can be radiated into the water WT from the radiation surface 3F by ultrasonically vibrating the metal ship bottom 3.

A back member 64 surrounding the piezoelectric element 61 and the buffer body 63 is provided behind (upward in FIG. 2) and around the piezoelectric element 61 and the buffer body 63. The backing material 64 is made of rubber and absorbs moisture, insulation, unnecessary vibration, and reverberation vibration of the piezoelectric element 61.
Further, the ultrasonic transducer 6 includes a rubber float 65 made of rubber. The rubber float 65 includes a surrounding portion 65H having a bottomed cylindrical shape surrounding the back member 64 and the aluminum matching body 62, and a bush extending radially outward from the surrounding portion 65H and gripping the cable 66 in a liquid-tight manner. Part 65B. Further, the inner peripheral surface 65I of the surrounding portion 65H and the peripheral portions of the outer peripheral surface 62G and the back surface 62B of the aluminum matching body 62 are in close contact (adhesion) with each other.
Note that an engagement flange 62T is provided on the outer peripheral surface 62G of the aluminum aligning body 62 so that the aluminum alignment body 62 is difficult to be removed from the surrounding portion 65H. Further, an internal space SP is formed between the inner peripheral surface 65I of the surrounding portion 65H and the back member 64, so that ultrasonic vibration is not transmitted to the surrounding portion 65H of the rubber float 65 through the back member 64. So-called edge cutting is done.

Now, in the ultrasonic transducer 6 of the first embodiment, the aluminum matching body 62 is interposed between the piezoelectric element 61 and the metal ship bottom 3 in relation to the metal ship bottom 3 of the boat 1, and further the thickness ts. Is set as follows. That is, the thickness (axis AX direction dimension) of the aluminum matching body 62 is ts, the wavelength of the ultrasonic vibration transmitted through this is λs, the thickness of the metal ship bottom 3 of the boat 1 (axis AX direction dimension) is tb, When the wavelength of the sonic vibration is λb, the thickness ts of the aluminum matching body 62 is adjusted so as to satisfy the following formula (1).
1 / 2-1 / 10 ≦ tb / λb + ts / λs ≦ 1/2 + 1/10 Equation (1)
The wavelength λs is obtained from the vibration frequency f of the transmitted ultrasonic vibration and the sound velocity vs in the thickness direction of the aluminum matching body 62 by λs = vs / f. Similarly, the wavelength λb is obtained by λb = vb / f from the vibration frequency f of the transmitted ultrasonic vibration and the sound velocity vb in the thickness direction of the metal ship bottom 3.

Specifically, in the boat 10 with a fish finder of the first embodiment, f = 120 kHz, vs = 6345 m / s, and vb = 6445 m / s, so that λs = 52.88 mm and λb = 53.79 mm. . Also, ts = 20 mm and tb = 6.0 mm. Therefore, tb / λb + ts / λs = 0.48, and it can be seen that it is included in the range of the expression (1).
Note that the sound speeds vb and vs in the thickness direction of the metal ship bottom 3 or the aluminum matching body 62 are obtained by measuring the thickness of the metal ship bottom 3 or the aluminum matching body 62 using an ultrasonic thickness gauge having a known frequency. From the comparison with the separately measured thicknesses tb and ts, actual sound velocities vb and vs were obtained. Specifically, the thickness of the metal ship bottom 3 (actually, the same material and the same thickness aluminum alloy flat plate, □ 200 × t6) and the aluminum matching body 62 are measured using a micrometer. On the other hand, using an ultrasonic thickness meter (Tokyo Keiki Co., Ltd., UTM100, pulse reflection method, not shown), the thickness of the metal ship bottom 3 (actually the above-mentioned flat plate) and the aluminum matching body 62 is measured, and the ultrasonic thickness is measured. The sound speed is changed by the sound speed measurement switch of the meter, and the sound speeds vb and vs of the metal ship bottom 3 and the aluminum matching body 62 are obtained by changing the sound speed displayed by the ultrasonic thickness meter to the thickness actually measured by the micrometer. It was. In addition, since the measurement accuracy (display accuracy) of the thickness of the ultrasonic thickness gauge is 0.1 mm, the obtained sound speed may have a width. In this case, the median value of the sound speed range was set as the true sound speed.

This equation (1) will be described. Formula (1) sets the allowable width of tb / λb + ts / λs to ± 1/10 with the value of tb / λb + ts / λs centered around tb / λb + ts / λs = 1/2.
In general, where t is the thickness of an object and λ is the wavelength of ultrasonic vibrations transmitted through the object, t / λ is the number of ultrasonic vibration waves (how many wavelengths) in the thickness direction of the object. Indicates whether Therefore, this equation (1) effectively includes 1/2 wave (1/2 wavelength) of ultrasonic vibration waves transmitted through the aluminum matching body 62 and the metal ship bottom 3. This indicates that it is preferable to have a dimensional relationship or a dimensional relationship approximate thereto.

This is because when the ultrasonic wave USR is radiated from the radiation surface 3F of the metal ship bottom 3 into the water WT having higher acoustic impedance (lower sound speed) than this, an appropriate thickness is applied to the inner surface 3B of the metal ship bottom 3. The aluminum matching body 62 having a length tb is added, and the aluminum matching body 62 and the metal ship bottom 3 are combined to effectively constitute a λ / 2 resonator. Accordingly, it is considered that the ultrasonic wave USR can be efficiently radiated from the radiation surface 3F into the water in the front surface (axis AX direction). As a result, generation of side lobes can be suppressed. As described above, the aluminum matching body 62 and the metal ship bottom 3 are combined to form an effective λ / 2 resonator, so that vibration in the thickness direction (axis AX direction) is selectively excited. This is thought to be because the occurrence of vibration in the direction (radial vibration) is suppressed.
If the allowable width of tb / λb + ts / λs is set to ± 1/10, within this range, the aluminum matching body 62 and the metal ship bottom 3 are combined to obtain an effective λ / 2 resonance. This is because the ultrasonic wave USR can be efficiently radiated from the radiation surface 3F into the water in the front surface (in the direction of the axis AX), and the occurrence of side lobes can be sufficiently suppressed.

Next, with respect to the boat with a fish finder according to Example 1 and Comparative Examples 1 and 2, the directivity, the transmitted sound pressure to the front (axis AX direction), the reception sensitivity of ultrasonic waves from the front (axis AX direction) Was measured. However, since it is difficult to measure the directivity using an actual boat 1 because a large-scale device is required, it is made of an aluminum alloy of the same material instead of the metal ship bottom 3 and has the same thickness tb = 6. An implementation sample 1 in which the ultrasonic transducer 6 was bonded to the center of a flat plate having a plane size of 200 × 200 mm having 0 mm was prepared, and its directivity was measured. A similar flat plate is used for the ultrasonic transducer according to Comparative Example 2 to obtain Comparative Sample 2.
Further, as described above, in the ultrasonic transducer 6 of the first embodiment (implemented sample 1), the piezoelectric element 61 has a diameter of 40 mm and a thickness of 10 mm. The aluminum matching body 62 has a diameter of 80 mm and a thickness of 20 mm.
On the other hand, as Comparative Example 1, an ultrasonic vibrator including the piezoelectric element 61 and the buffer body 63 and not including the aluminum matching body 62 is created, and this is directly thrown into water without being fixed to the metal ship bottom 3, Its directivity was measured.
Further, as Comparative Example 2 (Comparative Sample 2), the ultrasonic transducer (specifically, buffer body 63) used in Comparative Example 1 was bonded to the above-described flat plate (tb = 6.0 mm, 200 × 200 mm). A product was made and its directivity was measured.

  The results of the directivity characteristics are shown in FIG. 3 for Example 1 (Example 1), FIG. 4 for Comparative Example 1, and FIG. 5 for Comparative Example 2 (Comparative Sample 2). FIG. 6 shows the frequency characteristics of the transmitted sound pressure, and FIG. 7 shows the frequency characteristics of the received wave sensitivity.

  The transmitted sound pressure is measured by putting the working sample 1 or the like with the ultrasonic vibrator 6 bonded to the flat plate into water, keeping the axis AX of the ultrasonic vibrator 6 horizontal at a depth of 1 m, and using the main body device 5. The ultrasonic wave transmitted underwater is detected by a receiver (Oki Electric Industry Co., Ltd., ST-1004, not shown) disposed at a position 1 m away from the axis. The output of the receiver is observed with an oscilloscope (not shown). The transmitted sound pressure P is calculated by P (dB) = Vr−km. Here, P is the sound pressure level of the transmitted sound pressure (0 dB = 1 μPa), Vr is the output level of the receiver (0 dB = 1 Vrms), and km is the receiving sensitivity of the receiver (0 dB = 1 Vrms / μPa). . The frequency characteristic of the transmitted sound pressure shown in FIG. 6 is obtained by measuring the transmitted sound pressure at each frequency by changing the drive frequency of the main unit 5.

  For the directivity, the output voltage of the receiver is measured in the same manner as the measurement of the transmitted sound pressure. At this time, the state where the receiver is positioned on the axis AX of the ultrasonic transducer 6 (the state where the receiver is directly facing the flat plate) is set to an angle θ = 0 °, and the axis AX of the ultrasonic transducer 6 is horizontally aligned. Rotate in the horizontal plane while maintaining the position, and measure the output voltage of the receiver at each angle. Further, the relative intensity G at each angle θ is calculated by G (dB) = 20 Log (Vθ / V0). Here, V0 is the output voltage of the receiver at an angle θ = 0 °, and Vθ is the output voltage of the receiver at an angle θ. Further, the size of the angle range in which the relative intensity G is within −6 dB is calculated as the directivity angle α.

  Furthermore, the reception sensitivity is different from the above-described measurement of the transmitted sound pressure and directivity, and the sample 1 or the like in which the ultrasonic transducer 6 is bonded to a flat plate is poured into the water, and the ultrasonic transducer 6 has a depth of 1 m. Keep axis AX horizontal. In addition, an ultrasonic wave is generated by driving a wave transmitter (manufactured by Oki Electric Industry Co., Ltd., ST-1004, not shown) disposed at a position 1 m away on this axis, and the ultrasonic wave transmitted through the water is an ultrasonic transducer. 6 is received and the output is observed with an oscilloscope (not shown). From the output voltage of the ultrasonic transducer 6 obtained by the oscilloscope, the received wave sensitivity S is calculated by S (dB) = VTD− (Vs + Ks). Here, S is the receiving sensitivity of the ultrasonic transducer (0 dB = 1 Vrms / μPa), VTD is the level of the output voltage of the ultrasonic transducer 6 (0 dB = 1 Vrms), and Ks is the transmission intensity (0 dB) of the transmitter. = 1 μPa / Vrms · m). The frequency characteristic of the reception sensitivity shown in FIG. 7 is obtained by measuring the reception sensitivity at each frequency by changing the frequency of the ultrasonic wave by the transmitter.

According to the graph of FIG. 3, in the working sample 1 using the ultrasonic transducer 6 according to the first embodiment, the directivity angle (angle range of −6 dB or more) α of the main beam appearing near the angle 0 deg is It can be seen that α = 14 deg and the side lobe peak is suppressed to −17 dB or less as compared with the main beam.
On the other hand, in the ultrasonic transducer according to Comparative Example 1, the directivity angle α of the main beam is α = 20 deg, and the peak of the side lobe is suppressed to −13 dB or less compared to the main beam. (See FIG. 4).
In the comparative sample 2 using the ultrasonic transducer according to the comparative example 2, the directivity angle α of the main beam is α = 22 deg, and the peak of the side lobe is suppressed only by −4 dB compared to the main beam. It turns out that there is no (refer FIG. 5).

  Further, according to the frequency characteristics of the transmission sound pressure P of each sample shown in FIG. 6, the ultrasonic transducer 6 is disposed in the boat 1 in the implementation sample 1 (▲ mark) having the aluminum matching body 62. However, it can be seen that the transmitted sound pressure P is almost the same as that of Comparative Example 1 (♦ mark: underwater throwing type). On the other hand, in the comparative sample 2 (■ mark) that does not have the aluminum matching body 62, it can be seen that the transmitted sound pressure P is reduced by about 10 dB compared to the working sample 1.

  Further, in the frequency characteristic of the received wave sensitivity S shown in FIG. 7, the implementation sample 1 having the aluminum matching body 62 (marked with ▲) is almost the same as the comparative example 1 (♦ mark: underwater throwing type), and partly. It turns out that the receiving sensitivity S exceeding this is obtained. On the other hand, in the comparative sample 2 (■ mark) that does not have the aluminum matching body 62, it can be seen that the received wave sensitivity S is also reduced by about 10 dB as compared with the working sample 1.

From the comparison between the above-described comparative example 1 (FIG. 4) and comparative example 2 (comparative sample 2: FIG. 5), a normal submerged ultrasonic transducer (comparative example 1 having no aluminum matching body) (comparison) When Example 1) is bonded to the bottom of a metal ship (Comparative Example 2), it can be seen that the directivity angle α increases and the side lobe increases. It can also be seen that the transmitted sound pressure (radiation intensity) P and the received sensitivity S are significantly reduced.
In the case of Comparative Example 2 (Comparative Sample 2), there is no aluminum matching body when the ultrasonic vibration generated by the piezoelectric element is radiated into the water from the bottom of the metal ship (a flat plate in the case of Comparative Sample 2). In addition, inconsistency occurs in both the transmission of ultrasonic vibration from the piezoelectric element to the bottom of the metal ship and the transmission of ultrasonic vibration from the bottom of the metal ship to the water. For this reason, reflection and loss occur at each interface, and it is understood that ultrasonic waves could not be radiated into water with sufficient intensity. In addition to the vibration in the thickness direction of the piezoelectric element, the vibration in the radial direction is also excited, the main beam intensity decreases and the directivity angle α increases, and a large peak appears as a side lobe. Conceivable.

On the other hand, when the ultrasonic transducer 6 according to the first embodiment is used (embodiment sample 1: FIG. 3), not only the comparison example 2 (comparison sample 2: FIG. 5) but also the comparison example 1 (FIG. 4). ) Has a small directivity angle α and can radiate a sharp ultrasonic beam into water, and the side lobes can be sufficiently suppressed as compared with Comparative Examples 1 and 2. Further, the transmission sound pressure (radiation intensity) P of the ultrasonic wave USR is approximately the same as that of the submerged-throw ultrasonic transducer (Comparative Example 1), and can radiate the ultrasonic wave USR without loss.
In this way, by using the ultrasonic vibrator 6 including the aluminum matching body 62, the ultrasonic vibrator 6 (the boat including the ultrasonic vibrator 6) can be used as compared with the comparative example 2 (comparative sample 2) having no aluminum matching body. The radiation characteristic and directivity characteristic of the ultrasonic wave USR in 10) can be greatly improved. In addition, it can be seen that the characteristics equal to or higher than those of the submerged-throw type ultrasonic transducer (Comparative Example 1) can be obtained. Furthermore, the receiving sensitivity for receiving the ultrasonic wave USP from underwater can be greatly improved as compared with Comparative Example 2 (Comparative Sample 2) without an aluminum matching body. It can be seen that characteristics equivalent to those of the child (Comparative Example 1) can be obtained.

  Thus, the boat 10 with a fish detector, the fish detector 4 and the ultrasonic transducer 6 according to the first embodiment have good ultrasonic radiation characteristics and directivity characteristics while the ultrasonic transducer 6 is disposed in the ship. A boat with a fish finder having reception characteristics, a fish finder, and an ultrasonic transducer.

Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment described above, the boat 10 with a fish detector in which the ultrasonic transducer 6 of the fish detector 4 is fixed to the metal bottom 3 of the boat 1 has been described.
On the other hand, the second embodiment is applied to the underwater ultrasonic exploration device 140 used in the ship SH, and uses the ultrasonic transducer 6 having the same configuration as that of the sixth embodiment. Therefore, different parts will be described, and description of similar parts will be omitted or simplified.

  The underwater ultrasonic exploration device 140 according to the second embodiment includes a main body device 150 and a probe 160 including the ultrasonic transducer 6. Among these, the main body device 150 drives the ultrasonic transducer 6 and analyzes the output (ultrasonic wave reception output) to obtain data on the state of the water, the state of the water bottom (the sea bottom, the lake bottom), and the like. The main body device 150 includes a drive power supply 151 for driving the ultrasonic transducer 6.

On the other hand, the probe 160 has an ultrasonic transducer 6 and a case 161 that surrounds the ultrasonic transducer 6 and is hermetically sealed. Among these, the ultrasonic transducer 6 is the same as that of the first embodiment (see FIG. 2). The case 161 has a rectangular parallelepiped shape, and the bottom of the water contact portion 162 submerged under the water surface WS is a metal water contact portion 163 (thickness tc = 6.0 mm) made of an aluminum alloy. The ultrasonic transducer 6 (specifically, the aluminum matching body 62) is closely bonded to the inner side surface 163B of the metal water contact portion 163.
The cable 66 of the ultrasonic transducer 6 is taken out from the case 161 in a liquid-tight manner and connected to the main body device 150.

  Thus, also in this underwater ultrasonic exploration apparatus 140, the radiation of the metal water contact portion 613 is achieved by driving the ultrasonic vibrator 6 with the drive power supply 151 of the main body apparatus 150 at a predetermined frequency (f = 120 kHz in this example). From the surface 163F, ultrasonic USR can be emitted. Further, the ultrasonic transducer 6 can receive the ultrasonic wave USP incident on the radiation surface 3.

Moreover, as in the first embodiment, the ultrasonic transducer 6 is provided with the aluminum matching body 62, the thickness (axis dimension in the axis AX direction) of the aluminum matching body 62 is ts, and the wavelength of the ultrasonic vibration transmitted through this is λs. When the thickness (axis AX direction dimension) of the metal water contact portion 163 of the case 161 is tc and the wavelength of the ultrasonic vibration transmitted through this is λc, the thickness of the aluminum matching body 62 so as to satisfy the following formula (2): ts has been adjusted.
1 / 2-1 / 10 ≦ tc / λc + ts / λs ≦ 1/2 + 1/10 Equation (2)

Specifically, in the underwater ultrasonic survey apparatus 140 of the second embodiment, f = 120 kHz, vs = 6345 / s, and vc = 6445 m / s, so that λs = 52.88 mm and λc = 53.79 mm. . Further, ts = 20 mm and tc = 6.0 mm. Therefore, tc / λc + ts / λs = 0.48, and it can be seen that it is included in the range of equation (2).
Note that the sound velocity vc in the thickness direction of the metal water contact portion 163 is also compared with the thickness tc measured separately by measuring the thickness of the metal water contact portion 163 using an ultrasonic thickness meter with a known frequency. From this, the actual sound velocity vc was calculated.

  This equation (2) will be described. Similarly to the above-described formula (1), the formula (2) is obtained by setting the value of tc / λc + ts / λs to a tolerance of ± 1/10 around tc / λc + ts / λs = 1/2. is there. This formula (2) is a dimension in which the ultrasonic vibration wave transmitted through the aluminum matching body 62 and the metal water contact portion 163 is effectively included in half (1/2 wavelength). It is shown that it is preferable to have a relationship or a dimensional relationship approximate to this relationship.

When the ultrasonic wave USR is radiated into the water WT from the radiation surface 163F of the metal water contact portion 163, an aluminum alignment body 62 is added to the inner side surface 163B of the metal water contact portion 163, and the aluminum alignment body 62 and the metal ship Together with the bottom 3, an effective λ / 2 resonator is formed. Accordingly, it is considered that the ultrasonic wave USR can be efficiently emitted from the radiation surface 163F to the front surface (underwater). As a result, generation of side lobes can be suppressed. By combining the aluminum matching body 62 and the metal water contact portion 163 to constitute an effective λ / 2 resonator, vibration in the thickness direction (axis AX direction) is selectively excited, and in other directions This is considered to be because the occurrence of vibration (radial vibration) is suppressed.
If the allowable width of tc / λc + ts / λs is set to ± 1/10, within this range, the aluminum matching body 62 and the metal water contact portion 163 can be combined and effectively λ / 2. This is because a state close to a resonator can be obtained, and the ultrasonic wave USR can be efficiently radiated from the radiation surface 3F to the front surface (in the direction of the axis AX), while the occurrence of side lobes can be sufficiently suppressed.

  Thus, also in the underwater ultrasonic exploration apparatus 140 of the second embodiment, the ultrasonic wave USR can be efficiently radiated from the metal water contact portion 163 into the water. In addition, the ultrasonic wave USP incident from underwater can be efficiently transmitted to the piezoelectric element 61. In addition, the directivity is good and the occurrence of side lobes can be suppressed. Thus, the underwater ultrasonic exploration apparatus 140 has good ultrasonic radiation characteristics and reception characteristics.

In the above, the present invention has been described with reference to the first and second embodiments. However, the present invention is not limited to the first and second embodiments, and can be appropriately modified and applied without departing from the gist thereof. Needless to say.
For example, in the first embodiment, an example in which the entire hull is applied to the boat 1 made of aluminum is shown. However, the entire hull may be made of, for example, FRP, wood, etc. You may apply to ships, such as a boat provided with the metal ship bottom part which 6 can be attached.
Moreover, in Example 1, although the example which joined the aluminum alignment body 62 which also consists of aluminum alloys to the metal ship bottom part 3 or metal water contact part 163 which consists of aluminum alloys was shown, metal ship bottom part 3 (metal water contact part) Depending on the material of 163), the aluminum matching body 62 may be replaced with a wavelength matching body of another material. At this time, it is preferable that the wavelength matching body is made of the same material as the metal ship bottom (metal wetted part) or a similar alloy.

  Moreover, in the underwater ultrasonic survey apparatus 140 of Example 2, although what showed the ultrasonic transducer | vibrator 6 in the probe 160 was shown, in addition to this ultrasonic transducer | vibrator 6, a thermometer, a manipulator, and other apparatuses are included. It is good as a thing. In the second embodiment, the probe 160 is exemplified as being used near the water surface. However, the probe 160 may be applied to a configuration in which the entire probe 160 is submerged in water. Further, the case 161 is not limited to a rectangular parallelepiped shape, and can be formed in an appropriate shape as long as the metal water contact portion 163 to which the ultrasonic transducer 6 is fixed can be secured. Further, the present invention can be applied to a manned exploration device in which a human enters the probe.

It is explanatory drawing which shows the structure of the aluminum ship with a fish finder based on Example 1. FIG. It is sectional drawing concerning Example 1, 2 and showing the structure of an ultrasonic transducer | vibrator and the relationship with a metal ship bottom part or a metal water contact part. It is a graph which shows the radiation directivity characteristic of the ultrasonic wave in the implementation sample 1 which adhere | attached the ultrasonic transducer | vibrator concerning a present Example to the aluminum plate which imitated the aluminum ship. 6 is a graph showing the radiation directivity characteristic of an ultrasonic wave in the ultrasonic transducer according to Comparative Example 1. It is a graph which shows the radiation directivity characteristic of the ultrasonic wave in the comparative sample 2 which adhere | attached the ultrasonic transducer | vibrator concerning the comparative example 2 to the aluminum plate which imitated the aluminum ship. It is a graph which shows the frequency characteristic of a transmission sound pressure about the implementation sample 1, the comparative example 1, and the comparative sample 2. FIG. It is a graph which shows the frequency characteristic of a receiving sensitivity about the implementation sample 1, the comparative example 1, and the comparative sample 2. FIG. It is explanatory drawing which shows the structure of the underwater ultrasonic survey apparatus which concerns on Example 2. FIG.

Explanation of symbols

10 Boat with fish finder (ship with underwater ultrasonic device)
DESCRIPTION OF SYMBOLS 1 Boat 2 (Bottom) Ship bottom 3 Metal ship bottom tb Thickness of metal ship bottom vb Sound velocity of ultrasonic vibration transmitted through the metal ship bottom λb Wavelength 3B of ultrasonic vibration with a predetermined frequency transmitted through the metal ship bottom (in the metal ship bottom ) Inboard side 3F Radiation surface 4 (at the bottom of a metal ship) Fish finder (Underwater ultrasonic equipment)
5 Main unit 51 (Power source of ultrasonic transducer) 52 Power source 52 Display 6 Ultrasonic transducer 61 Piezoelectric element (vibration element)
61F Front 61B Back AX Axis f (of piezoelectric element) Vibration frequency of vibration element (drive frequency of drive power supply)
62 Aluminum matching body (wavelength matching body)
62F front surface 62B back surface ts thickness of aluminum matching body vs. sound velocity λs of ultrasonic vibration transmitted through aluminum matching body wavelength 63 of ultrasonic vibration of predetermined frequency transmitted through wavelength matching body buffer body 140 underwater ultrasonic exploration device 161 (underwater ultrasonic wave Case 162 of exploration device Water contact part 163 Metal water contact part tc Thickness of metal water contact part (thickness of the part where ultrasonic vibration is transmitted in metal water contact part)
vc The speed of ultrasonic vibration λc transmitted through the metal wetted part Wavelength 163B of the ultrasonic vibration having a predetermined frequency transmitted through the metal wetted part (inside the metal wetted part) 163F Radiation surface (of the metal wetted part)

Claims (7)

The bottom of the ship is a metal ship bottom made of metal,
A ship with an underwater ultrasonic device including an underwater ultrasonic device including an ultrasonic vibrator attached to an inner surface of the metal ship bottom;
The ultrasonic transducer is
A vibration element that vibrates ultrasonically in a predetermined vibration direction at a predetermined frequency;
A wavelength matching body having the predetermined vibration direction as a thickness direction, wherein the vibration element is directly or indirectly stacked in the predetermined vibration direction, is in contact with the inner surface of the ship, and performs wavelength matching. Including
The wavelength of the ultrasonic vibration having the predetermined frequency that travels along the bottom of the metal ship is λb,
The thickness of this metal ship bottom is tb,
The wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the wavelength matching body is λs,
When the thickness of this wavelength matching body is ts,
It is configured to satisfy the following formula (1) 1 / 2-1 / 10 ≦ tb / λb + ts / λs ≦ 1/2 + 1/10 (1)
Ship with underwater ultrasonic equipment. A ship with an underwater ultrasonic device according to claim 1,
The metal ship bottom is made of aluminum or aluminum alloy,
A ship with an underwater ultrasonic device, wherein the wavelength matching body is also made of aluminum or an aluminum alloy. A ship with an underwater ultrasonic device according to claim 1 or 2,
The ultrasonic transducer is a ship with an underwater ultrasonic device including a buffer body made of rubber between the vibration element and a wavelength matching body. An underwater ultrasonic device for use in a ship in which at least a part of the ship bottom is a metal ship bottom made of metal,
Including an ultrasonic transducer that is scheduled to be attached to the inside surface of the metal ship bottom,
The ultrasonic transducer is
A vibration element that vibrates ultrasonically in a predetermined vibration direction at a predetermined frequency;
A wavelength matching body having the predetermined vibration direction as a thickness direction, wherein the vibration element is directly or indirectly stacked in the predetermined vibration direction, is in contact with the inner surface of the ship, and performs wavelength matching. Including
The wavelength matching body is
The wavelength of the ultrasonic vibration having the predetermined frequency that travels along the bottom of the metal ship is λb,
The thickness of this metal ship bottom is tb,
The wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the wavelength matching body is λs,
When the thickness of this wavelength matching body is ts,
It has a thickness ts satisfying the following formula (1) 1 / 2-1 / 10 ≦ tb / λb + ts / λs ≦ 1/2 + 1/10 (1)
Underwater ultrasonic equipment. An ultrasonic transducer,
An underwater ultrasonic device comprising at least a case surrounding the ultrasonic transducer,
Among the above cases, at least a part of the water contact part that comes into contact with water during use is a metal water contact part made of metal,
The ultrasonic transducer is
It is attached to the inside surface of the metal water contact part,
A vibration element that vibrates ultrasonically in a predetermined vibration direction at a predetermined frequency;
A wavelength matching body having the predetermined vibration direction as a thickness direction, wherein the vibration element is stacked directly or indirectly in the predetermined vibration direction, is in contact with the inner surface, and performs wavelength matching. Including
The wavelength matching body is
The wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the metal wetted part is λc,
The thickness of the portion where the ultrasonic vibration is transmitted in the metal water contact portion is tc,
The wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the wavelength matching body is λs,
When the thickness of this wavelength matching body is ts,
It has a thickness ts satisfying the following formula (2) 1 / 2-1 / 10 ≦ tc / λc + ts / λs ≦ 1/2 + 1/10 (2)
Underwater ultrasonic equipment. In a ship in which at least a part of the ship bottom is a metal ship bottom made of metal, an ultrasonic transducer that is scheduled to be attached to the inside surface of the metal ship bottom,
A vibration element that vibrates ultrasonically in a predetermined vibration direction at a predetermined frequency;
A wavelength matching body having the predetermined vibration direction as a thickness direction, wherein the vibration element is directly or indirectly stacked in the predetermined vibration direction, is in contact with the inner surface of the ship, and performs wavelength matching. Including
The wavelength matching body is
The wavelength of the ultrasonic vibration having the predetermined frequency that travels along the bottom of the metal ship is λb,
The thickness of this metal ship bottom is tb,
The wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the wavelength matching body is λs,
When the thickness of this wavelength matching body is ts,
It has a thickness ts satisfying the following formula (1) 1 / 2-1 / 10 ≦ tb / λb + ts / λs ≦ 1/2 + 1/10 (1)
Ultrasonic vibrator. It is planned that at least a part of the water contact part in contact with water at the time of use will be attached to the inner surface of the metal water contact part of the case that is a metal water contact part made of metal. An ultrasonic transducer,
A vibration element that vibrates ultrasonically in a predetermined vibration direction at a predetermined frequency;
A wavelength matching body having the predetermined vibration direction as a thickness direction, wherein the vibration element is directly or indirectly stacked in the predetermined vibration direction, is in contact with the inner surface, and performs wavelength matching. Including
The wavelength matching body is
The wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the metal wetted part is λc,
The thickness of the portion where the ultrasonic vibration is transmitted in the metal water contact portion is tc,
The wavelength of the ultrasonic vibration having the predetermined frequency transmitted through the wavelength matching body is λs,
When the thickness of this wavelength matching body is ts,
It has a thickness ts satisfying the following formula (2) 1 / 2-1 / 10 ≦ tc / λc + ts / λs ≦ 1/2 + 1/10 (2)
Ultrasonic vibrator.

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