JP3538817B2 - Underwater transmitter / receiver capable of emitting multiple frequencies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wave transmitting and receiving apparatus using a ceramic vibrator mounted on an ultrasonic sounding device or a fish finder used in seawater or underwater. Conventionally, the ceramic vibrator used for this purpose is 1
Only one ultrasonic wave was emitted from one transmitting / receiving device. The reason is that there is only one frequency at which ultrasonic waves can be emitted most efficiently in one ceramic vibrator, and the performance is lower than that of all others. However, the applicant has succeeded in making this a high-performance ultrasonic output, and has succeeded in efficiently emitting a plurality of frequencies while using only one vibrator.

[0002]

2. Description of the Related Art As is well known, the structure of a conventional wave transmitting / receiving apparatus of this kind is provided with a diaphragm (2) made of rubber or nylon on the front surface of a ceramic vibrator (1) as shown in FIG. On the opposite back side, a sheet (4) of styrene foam or the like that absorbs the emission of ultrasonic waves is directly adhered to the back of the ceramic vibrator (1), and an air chamber (5) or the like is provided behind it, and an ultra Ultrasonic frequency which emits ceramic vibrator most efficiently both mechanically and electrically in ceramic transmitting / receiving device. In general, there is only one location and one element can emit only one ultrasonic wave.

[0003]

SUMMARY OF THE INVENTION As a performance improvement of a wave transmitting and receiving apparatus, the applicant previously attached a heavy object having a large acoustic impedance to a surface of a ceramic vibrator opposite to a diaphragm side to improve the efficiency of sound emission. We have applied for an improved version to emit more powerful ultrasonic waves from the diaphragm side. However, in this case, the bonding structure for bonding between the ceramic vibrator and the back body is generally unreliable because the entire surface is generally bonded. However, as a result of repeating a number of experiments afterwards, in the case of a low frequency or a relatively small ceramic oscillator where there is no complicated standing wave in one ceramic oscillator even at a high frequency, the ceramic oscillator and the back Adhesion between the object and the entire surface is sufficient, but if the frequency is high or if there is a complex standing wave with one vibrator being very large, it must be fixed at the node or antinode of the standing wave. It has been found that the performance is reduced. Therefore, the present application was filed by accumulating various experiments in order to realize the improved type.

[0004]

As described above, when the frequency of the ultrasonic wave is very high or the size of the ceramic vibrator is very large, a complicated standing wave is generated on the surface of one vibrator. Appear. And the standing wave always generates concentric nodes and antinodes in the same part.Nodal parts hardly vibrate and antinodes vibrate greatly. The present invention focuses on the fact that the ceramic vibrator repeats its original vibration without substantially hindering its performance if it is fixed using only the portion. Next, in the previous invention, the weight of a heavy object such as an iron lump provided on the back surface was considered to be as large as possible. However, if the weight of the heavy object is appropriately selected, the object also has its own vibration. And an appropriate natural frequency including the iron ingot can be selected. Therefore, the applicant has set that this natural frequency is adjusted to a constant multiple of the natural frequency of the ceramic vibrator to transmit a plurality of ultrasonic waves while using a single ceramic vibrator. The completed transmission and reception device is completed.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the present invention has been developed as an improved invention of Japanese Patent Application No. 8-357460 previously filed as a device for powerfully emitting ultrasonic waves into water. This is a common invention. Therefore, for example, an iron lump having a large acoustic impedance is arranged on the back surface of the ceramic vibrator that emits ultrasonic waves, and the entire surface is not directly adhered to support and bond between the iron lump and the ceramic vibrator but between them. If a standing wave is present on the surface of the ceramic vibrator and a standing wave is present on the surface of the ceramic vibrator, a portion of the node or antinode of the standing wave is adhered to the surface of the ceramic vibrator. The weight including the provided iron lump and the like and the ceramic vibrator is set and fixedly supported so that the mechanical natural frequency of the vibrator matches the second and third natural frequencies of the ceramic vibrator. is there.

[0006]

Embodiment 1 The contents of [Claim 1] show the basic contents of the present invention, and the mode of implementation is a conventional ultrasonic wave transmitting / receiving apparatus or a transmitting / receiving apparatus which is improved thereafter. It can be applied to all wave transmitting and receiving devices such as devices. A concrete embodiment will be described with reference to FIG. 1. (1) is a ceramic vibrator which is the same as a conventional ceramic vibrator. A structure different from the conventional one in which a diaphragm (2) made of nylon or the like is provided is a back-side structure. An acoustic rigid body (8) consisting of an iron mass (3) similar to that shown in the previous application and having a high acoustic impedance is bonded to the back of the rigid body (8), except for the structure shown here. Are not different from conventional structures. The reason why the acoustic rigid body (8) made of porcelain or ceramic is provided between the ceramic vibrator (1) and the iron lump (3) is as described in the section [Problems to be Solved by the Invention]. When a standing wave is present on the surface of the ceramic vibrator (1), the entire surface is directly acoustically adhered to an object having a large acoustic impedance such as an iron lump (3) which is a rigid body. This is because the efficient vibration of the above is hindered and its performance cannot be sufficiently exhibited. The reason why the material of the acoustic rigid body (8) is made of porcelain or ceramic is that an iron lump may be used as long as it is acoustically the same rigid body. It is made of porcelain or ceramic which is an electrical insulator because the stray capacitance existing in the periphery cannot be ignored.

[0007]

[Embodiment 2] This is a concrete embodiment of the contents shown in [Claim 2], and this embodiment is an embodiment in which a plurality of ceramic vibrators are mounted in one transmitting / receiving device. The structure of the transmitter / receiver of this kind is a structure in which a plurality of ceramic vibrators are simply pasted on a single vibrating plate, so the mechanical vibration of the ceramic vibrator present there is compared with the total mass. The current situation was that the output was too small to produce the desired output because it was too small. On the other hand, the present embodiment can provide an epoch-making transmission / reception device that can efficiently output a large output with high efficiency, and a plurality of (1) shown in FIG. 2 will be described below. The feature is that a plurality of ceramic vibrators are mounted on one diaphragm (2). The structure up to this point is not different from the conventional one. A large acoustic impedance object (3) made of a single iron plate or the like, which can cover the entire back surface of the plurality of ceramic vibrators (1), is provided on the back surface of the ceramic vibrator (1). Can emit ultrasonic waves to the front much more efficiently than in the United States. This basic structure is 8-35
This is the same as that described in 7460. Further, a ring-shaped acoustic rigid body (8) made of porcelain, ceramic, or the like is provided between the back object (3) and the ceramic vibrator (1). Effect of the ring-shaped acoustic rigid body (8) Is the same as that described in the above [Example 1]. When the object (3) having a large acoustic impedance made of a rigid body such as an iron plate provided on the back is fixed directly to the back of the ceramic vibrator (1), the frequency is low. However, when the frequency becomes high, the vibration of the ceramic vibrator (1) is limited by the standing wave, and the performance cannot be sufficiently exhibited. (1)
A ring-shaped object (8) made of porcelain or ceramic, which is an acoustic rigid body, is provided therebetween.

Next, the content of [Claim 3] will be explained. [Claim 3] is that the present invention requires the conventional transmitting / receiving apparatus to emit a plurality of ultrasonic waves simultaneously with increasing the output. Japanese Patent Application No. 8-35 that demonstrates its power especially in low frequency bands
If the structure of the 7460 vibrator and the performance of a generally used vibrator are also taken into consideration, further improvement in performance can be expected, and these structures are also added to the present invention. That is, since the heavy object provided on the back surface is expressed as an iron lump or the like, the back object is not only an iron plate but also a vibrator shown in Japanese Patent Application No. 8-357460 or a ceramic vibrator which has been used conventionally. It is provided in place of an iron lump on the back side through an acoustic rigid body made of ceramic or the like, whereby these objects serve as heavy objects provided on the back side and at the same time the vibrations of these vibrators are provided on the front side By transmitting a frequency different from the frequency of the vibrator, a transmitting / receiving device having a large number of new frequencies can be obtained. However, in this case as well, it is a matter of course that the porcelain ring or the columnar object, which is an acoustically rigid body, is provided between the back object and the ceramic vibrator provided on the front surface.

As described above, in this embodiment, a great improvement in performance can be expected by adding various improvements to a conventional structural object, and at the same time, a plurality of ultrasonic frequencies can be used while being a single transmitting / receiving device. It is intended to provide an epoch-making wave transmitting / receiving apparatus which can emit. Of course, a single frequency can be emitted with its structure as it is [Claim 3].
The content shown in the figure below is to use the function of a heavy object and the frequency of the original vibrator of the back object by making the structure of the heavy object provided on the back a double structure and making it a heavy object including a ceramic oscillator or a simple heavy object. It is intended to provide an unprecedented wave transmitting / receiving apparatus which can efficiently emit each frequency. In the case of [Example 2] in which the frequency of the ultrasonic wave is very low, the ring-shaped acoustic rigid body (8) provided in the middle is eliminated entirely, and a plurality of ceramic vibrators (1) are used. It is also possible to directly wear the object (3) having a large acoustic impedance provided on the back surface and use the natural vibration frequency due to overall mechanical resonance including the ceramic vibrator (1) and the back object (3). Think. Such a concept does not exist in the conventional transmitting / receiving apparatus.

[0010]

The ultrasonic wave transmitting and receiving apparatus according to the present invention provides a wave transmitting and receiving apparatus capable of emitting a powerful ultrasonic wave, which has not been available conventionally. An application for a transmission / reception device similar to this was filed in 1996 as “Hei 8-357460”.
However, this application is based on the following experiment, when the frequency used is in the range of several tens KHz,
460 ", there is no problem, but when the frequency exceeds several hundred KHz, the effect of standing waves on the surface of the vibrator cannot be ignored. It has been found that the output acts rather in a direction that hinders the vibration of the vibrator, so that the present invention is devised as a countermeasure. Since the present invention acts both when transmitting and receiving ultrasonic waves including the previous one, its effect is so large that it cannot be ignored. Even if the difference is the lowest, even if the condition of improvement of several db is good, an improvement of ten and several db can be desired. Therefore, it is considered that this effect cannot be ignored.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view specifically showing the contents described in [Claim 1] of the ultrasonic wave emitting device according to the present invention.

FIG. 2 is a longitudinal sectional view specifically showing the contents shown in [Claim 2] in the ultrasonic launching apparatus of the present invention.

FIG. 3 is a specific longitudinal sectional view showing a typical embodiment of a conventionally used ultrasonic wave emitting device.

[Explanation of symbols]

(1) Ceramic vibrator (2) Vibrating plate (3) Heavy object provided on the back (4) Styrofoam sheet (5) Air chamber (6) Synthetic rubber outer frame (7) Electric cable (8) Ring shape Acoustic rigid body

Claims (3)

(57) [Claims] 1. An iron lump is mounted on the back surface of a ceramic ultrasonic transducer for use in seawater or underwater in order to increase the output. A ring-shaped object made of a porcelain or the like, which is a rigid body, is attached, and this object and the ceramic vibrator are supported by any one of the antinodes, nodes, and the center of the standing wave present in the ceramic vibrator. Fix the iron lump and the ceramic vibrator so that they are supported at a certain point, and fix the element itself. The natural vibration and the total natural vibration including the iron lump are 1
A transmitting / receiving device for emitting multiple frequencies, wherein the transmitting / receiving device is provided in a plurality of vibrators. 2. A transmitting / receiving device for ultrasonic emission used in seawater or underwater. In the transmitting / receiving device in which a plurality of ceramic vibrators are mounted in one transmitting / receiving device, a back surface of a plurality of ceramic vibrators is provided. 1 that covers the whole
An object having a high acoustic impedance, such as a piece of iron, is provided on the back surface of each element, and an object made of porcelain or the like having acoustic rigidity is provided on the back surface of each element in the same manner as described in [Claim 1]. The method is a single wave transmitting and receiving apparatus utilizing a plurality of natural vibrations of the element itself by supporting the standing wave at the antinode or node part or the central part of the standing wave of the ceramic vibrator. A transmitting / receiving device for transmitting multiple frequencies, wherein a plurality of ultrasonic vibrations contained therein are transmitted strongly into water. 3. A transmitting / receiving apparatus for ultrasonic emission using ceramics used in seawater or underwater, wherein a plurality of ultrasonic waves can be emitted while using a single apparatus [claims 1] and [2]. In the apparatus shown in [1], an object having a large acoustic impedance such as an iron block is provided on the back surface of the vibrator through an acoustically rigid body such as porcelain, but instead of the iron block, an iron block shown in Japanese Patent Application No. 8-357450 is used. A transmitting / receiving device for emitting multiple frequencies, wherein the transmitting / receiving device is provided by using an object to which a vibrator is attached or using a ceramic vibrator having a different frequency.