JPH0519825Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ultrasonic beam transmitting/receiving device suitable for an ultrasonic echo detector for detecting underwater objects.

[Conventional technology]

In order to provide a plurality of frequencies for transmitting and receiving waves (hereinafter referred to as "frequency"), a method of forming a vibrator using a piezoelectric element that resonates at a plurality of frequencies is disclosed in Japanese Utility Model Application Publication No. 57-46383. Disclosed in official gazettes, etc.

In addition, by arranging multiple vibrators at intervals,
Japanese Patent Application Laid-Open No. 57-119 discloses means for changing the directivity direction of the ultrasonic beam by variably arranging appropriate delay circuits, or for forming a focal point at a relatively short distance.
Publication No. 122373/Japanese Patent Publication No. 57-162591/Japanese Patent Publication No. 1987-162591
This is disclosed in Japanese Patent Publication No. 55-151280, Japanese Patent Publication No. 55-22992, etc.

Furthermore, Japanese Patent Application Laid-Open No. 1983-1987 discloses a means for making the intensity of reflected waves from the seabed surface uniform by changing the transmission output depending on the direction of the ultrasonic beam.
89766, etc., and Japanese Patent Laid-Open No. 56-63280 and others disclose means for moving and scanning a beam formed by a delay circuit in a parallel direction using a switching circuit.

By the way, in the field of underwater transceiver devices, which is the object of the present invention, for example, ultrasonic echo detectors such as fish finders use ultrasonic waves of 10 to 400 kilohertz. If a low frequency is used, underwater penetration is excellent, but it is susceptible to interference from underwater noise.

Also, if a high frequency is used, the underwater penetration power will be poor;
Less interference from underwater noise. Further, when the emission areas of the ultrasonic waves are equal, the beam width of a low frequency wave is wider than the beam width of a high frequency wave. When a fishing boat is equipped with a detector that uses a transducer with these properties, low-frequency ultrasonic waves are suitable for detecting deep waters, and high-frequency waves are suitable for detecting shallow waters where there is a lot of underwater noise.

However, in shallow water, the distance between the transducer and the water body is short, so the ultrasonic beam emitted from the transducer often does not hit the target object.
Therefore, it is often impossible to detect the echo of the target object.

For the above reasons, it is preferable to use ultrasonic waves for detecting underwater objects in combinations of low and high frequencies, wide beam widths, and narrow beam widths that are suitable for the expected water area of the target object.

[The problem that the idea aims to solve]

As mentioned above, the reason why detection is impossible is because a vibrator that resonates at a high frequency is used.
This is because the ultrasonic beam becomes extremely narrow, and the beam is directed in a direction away from its intended direction due to the shaking of the ship equipped with the transducer or underwater water currents.

By the way, in addition to the above, the detection ability of ultrasonic waves is also greatly influenced by the relationship between the frequency of the ultrasonic waves and the quality of the object to be detected. Higher frequencies are better for soft and weak objects such as mackerel and rock bottoms, but high frequencies are interfered with by the echoes of minute and soft objects such as those mentioned above when it comes to large or hard objects such as mackerel and rock bottoms. It is better to use a lower frequency where such disturbing echoes do not appear.

Therefore, it is desired to provide an underwater transceiver device having as many frequencies as possible and having a variable beam width.

Therefore, there is a problem of further developing the above-mentioned conventional technology to provide something simple and inexpensive for the above-mentioned purpose.

[Means for solving problems]

This idea is based on an underwater transceiver system in which a plurality of identical transducers are arranged, and lead wires connected to the transducers arranged at symmetrical positions with respect to the center of the arrangement are connected as one set for each symmetrical position. A delay circuit section is provided in which each lead wire connected to each set is extended by a cable and connected to each delay circuit through each switching circuit corresponding to each set, and each delay circuit is switched. An underwater transducer that can vary the beam width of transmitted and received ultrasonic waves by changing the amount of delay for each transducer, and each of the above transducers is used as a transducer that resonates at multiple frequencies. and a multi-frequency transducer planar arrangement means for arranging the transmitting and receiving wave surfaces of each transducer in a plane and arranging them at intervals, and a delay circuit interposed in one of the circuits switched by each of the switching circuits. In addition to providing a connection circuit that connects all directly to one input/output terminal for wave transmission and reception without having to input/output circuit means for providing connection circuits connected to the input/output terminals with respective delay circuits interposed in each of the other sets; The above-mentioned method can be achieved by providing a delay circuit configuring means for providing delay circuits in which the amount of delay is sequentially increased as the arrangement of the vibrators corresponding to each of the above-mentioned delay circuits moves outward from the center. It is designed to solve the following problems.

〔Example〕

Examples will be described below with reference to the drawings.

In FIG. 1, electrostrictive elements 1 to 6 are rectangular with length L, width W, and height H, and are made of barium titanate, for example.

The resonance frequencies of these electrostrictive elements are approximately inversely proportional to the length L, width W, and height H, and an example thereof is as follows. Dimensions are in millimeters.

L=40...Resonance frequency is approximately 40 kHz W=7...Resonance frequency is approximately 270 kHz H=19...Resonance frequency is approximately 80 kHz These electrostrictive elements are provided with electrodes plated with silver or the like on either side. When power at the above frequency is supplied to the electrode, mechanical vibration at that frequency is generated due to the electrostrictive effect.

However, depending on the dimensions of each side of the electrostrictive element, the mechanical vibrations mentioned above may interfere with each other, creating a frequency where the vibration becomes weaker. An electrostrictive element with multiple resonance frequencies can be obtained.

The mechanical vibrations generated as described above occur in the directions of each side of the electrostrictive element.

The electrostrictive elements 1 to 6 are bonded to the diaphragm 11 with adhesive G as shown in the figure, and a filler 15 containing a large amount of air bubbles is attached.
Sonically isolate. The diaphragm 11 is mainly made of a material, such as neoprene, whose sound wave characteristics are close to those of water, and is designed to emit ultrasonic waves into water through the diaphragm with as little loss as possible of the vibration of the electrostrictive element. Furthermore, since there is a filler 15 on the outer periphery of the electrostrictive elements 1 to 6, the resonant mechanical vibration is reflected by the filler 15, and the main force of the vibration is concentrated on the diaphragm 11, which causes the ultrasonic beam to be Fire into the water.

Figures 1 and 2 show an example in which the total number of electrostrictive elements is six, but increasing this total increases the ultrasonic emission area and increases the variable range of the ultrasonic beam width. .

The protective cover 13 protects the present invention from external forces and insulates the surroundings of the electrostrictive element from water.
As shown in the figure, the electrostrictive elements 1 to 6 are arranged at a specified interval by bonding them to the diaphragm 11. The electrostrictive elements are arranged at intervals of 1/2 to 2 wavelengths of the ultrasonic wave in water, but if the intervals are too large, the emitted beam will branch like a palm and fingers, degrading the echo detection field performance.

Further, it is impossible to make the above-mentioned interval narrower than 1/2 wavelength when the dimensions of the electrostrictive element are as in the above-mentioned example. Furthermore, although the electrostrictive elements in Figure 2 are arranged in one row in the direction of the width W, in order to emit a narrower and more powerful ultrasonic beam, several rows of electrostrictive elements are also arranged in the direction of the length L. All you have to do is place the . however,
Increasing the number of electrostrictive elements for the purpose of the above explanation,
The lead wire of cable 12 as described in At.
The quantity of delay circuits and switching relays will increase. Lead wires 16, 25 and 3 of cable 12
4 is connected to the electrostrictive elements 1 to 6, respectively, as shown in FIG.

The electrodes of the electrostrictive element in this example are located on two opposing surfaces of length L and width W. Therefore, one surface of the electrode is bonded to the diaphragm 11, and the lead wires are connected to the bonded surface of the electrode and its opposing surface, and the electrodes of each electrostrictive element are connected to each other by two lead wires. Although the signal is transmitted to an external circuit, one lead wire is used as a representative in the explanation of FIGS. 2 and 3.

In this example, when adjusting the ultrasonic beam width to the narrowest, ultrasonic power of approximately the same phase is applied to all electrostrictive elements, and when adjusting the beam width wider, electrostrictive elements 1, 6, and 2 are applied. By delaying the phase of the ultrasonic power applied to and 5 from the phase of electrostrictive elements 3 and 4, the central part of the diaphragm 11 appears to swell upward toward the water, and the electrostrictive elements are arranged in an arc shape. The characteristics are close to .

In Fig. 3, the lead wire 16 is connected to the switching relay K1.
A lead wire 25 is connected to the master contact of switching relay K25, and its child contact is connected to the delay circuit D25.

In this example, as already explained, a large delay time is created in order to delay the phase of the ultrasonic power supplied to the electrostrictive elements 1 and 6 connected to the lead wire 16 from the position of the other electrostrictive elements. A delay circuit D16 is used for this purpose. In other words, switching relay K
When 16 is a contact indicated by a solid line, ultrasonic power is supplied from the transmitting/receiving input/output terminal 18 via a delay circuit made up of inductance and capacitance, as illustrated in the figure.

Similarly, ultrasonic power is supplied to the lead wire 25 via a switching relay K25 and a delay circuit D25. Ultrasonic power is directly supplied to the lead wire 34 from the input/output terminal 18.

The delay time of the above-mentioned delay circuit is adjusted so that the apparent positions of the electrostrictive elements 1 to 6 in the state of emitting the ultrasonic beam have a desired beam width.
Therefore, when changing the width of the ultrasonic beam in this discussion, it is necessary to adjust the delay time of delay circuits D16 and D25, and FIG.
When 25 is in contact as shown by the dotted line, the beam width is narrow, and when it is in contact as shown in the solid line, the beam width is wide.

To summarize, in Fig. 2, each vibrator 1 to 6, whose L, W, and H sides resonate at a plurality of different frequencies, is set with its longitudinal direction L parallel to the transmitting and receiving wave surface. The transducers 1 to 6 constitute the underwater transducer section, which is arranged side by side.
A plurality of delay circuits D1 are extended by a cable 12 having respective leads 16, 25, 34 connected to the
6, which constitutes the delay circuit connected to D25.

The leads for each of the arrays of transducers 1 to 6 are arranged in such a way that the lead wires of the transducers in the rows arranged at symmetrical positions with respect to the centers of the plurality of rows of transducers 1 to 6 are set as one set for each symmetrical position. After connecting the lead wires 16, 25, and 34 inside the transducer part,
It is configured to lead to the delay circuit section.

Lead wires 34 for the vibrators 3 and 4 placed in the center are directly connected to the input/output terminals 18,
Regarding the lead wires for each vibrator placed outside the center, the lead wire 25 is connected to the switching relay K2.
5 to a short delay circuit D25 as shown in the figure, that is, a circuit that provides a small amount of delay, and then connected to the input/output terminal 18, and the lead wire 16 is connected to a long delay circuit D25 as shown in the figure through a switching relay K16. circuit D16,
In other words, after leading to a circuit that provides a large amount of delay,
A delay circuit is provided so as to be connected to the input/output terminal 18, and the amount of delay is sequentially increased from the center to the outside.

In addition, when each switching relay K16, K25 is connected to the dotted line side, each delay circuit D1 is included in one circuit.
6, a connection circuit connected to the input/output terminal 18 for transmitting and receiving waves is formed immediately without intervening D25, and when each switching relay K16, K25 is connected to the solid line side, the other circuit has each Delay circuit D
16 and D25, a connection circuit is formed to connect to the input/output 18.

Therefore, when the switching relays K16 and K26 are switched to the dotted line side, the width of the ultrasonic beam has narrow directivity due to the arrangement of the transducers 1 to 6 side by side, that is, Each vibrator 1 to 6
Sharp directivity can be achieved when the transmitting/receiving wave surfaces are formed into one planar shape.

Also, when the switching relays K16 and K26 are switched to the solid line side, compared to the arrangement in which each of the vibrators 1 to 6 are simply arranged side by side, the outer side of the vibrator 3 and 4 in the center part is Oscillator 2 located at
5 is given a small delay amount, and furthermore, the vibrators 1 and 6 located outside of it are given a large delay amount.

For this reason, with respect to the transmitting and receiving wave surface of the central oscillator,
As the transducer goes to the outer side, the wave transmitting/receiving surface has a larger delay amount, that is, the same wave transmitting/receiving surface is formed when the position is moved backward, and it is as if the transmitting/receiving surface is a convex curved surface that rises downward. It is possible to form a blunt directivity with a wider beam width, similar to when the beam is formed in the shape of a shape.

In other words, if the original beam width formed by the arrangement of the transducers as described above is B1 in FIG. When the wave is transmitted and received with a beam of beam width B1 and the switching relays K16 and 26 are switched to the solid line side, as shown in B2 in Fig. 4, the beam of beam width B1 is wider than the original beam width B1. It operates to transmit and receive waves.

It goes without saying that this embodiment is also effective in changing the width of the receiving beam of ultrasonic echoes.
In addition, the switching relays K16 and K2 shown in Fig. 3
5 and delay circuits D16 and D25, when changing the ultrasonic beam width in multiple stages, it is necessary to provide these circuits in accordance with the above-mentioned multiple stages. When changing the frequency of the ultrasonic waves applied to the electrostrictive element, it is preferable to use a delay circuit that takes into account so-called impedance matching in order to maintain the required delay time and transmission efficiency of transmitted and received waves as good as possible at that frequency.

[Effect of idea]

According to this idea, as described above, multiple oscillators that resonate at multiple frequencies are used and arranged in a row, and the amount of delay is increased as the outer side of the oscillator array increases with respect to the one in the center of the array. Since a switching structure is provided to make the beam width wider than the original beam width, it is possible to select and use an ultrasonic beam of any frequency suitable for underwater detection purposes, and it is also possible to use a high-frequency ultrasonic beam. Even if this option is unavoidable, it is possible to easily avoid detection failure due to extreme beam narrowing by simply operating the switching circuit. It has features such as being able to be provided depending on the configuration.

[Brief explanation of the drawing]

The drawings show an embodiment; Fig. 1 is a longitudinal sectional view of the transducer section, Fig. 2 is a rear view with the cover of the transducer section removed, mainly showing the arrangement of the transducer and the connection of the lead wires; FIG. 3 is a schematic diagram of the structure of the delay circuit portion, and FIG. 4 is a longitudinal cross-sectional view of the beam width changing state. 1, 2, 3, 4, 5 and 6...electrostrictive element, 1
1...Diaphragm, 12...Connection cable, 13...
Protective cover, 14...Position of protective cover, 15...
...filling, 16...lead wires of electrostrictive elements 1 and 6,
25... Electrostrictive element, lead wires 2 and 5, 34...
Lead wires of electrostrictive elements 3 and 4, G...adhesive, L...
...Length of electrostrictive element, W...Width of electrostrictive element, H...
Height of electrostrictive element, 18... Input/output terminal for transmission and reception,
D16...Delay circuit for electrostrictive elements 1 and 6, D25...
...Delay circuit for electrostrictive elements 2 and 5, K16...Switching relay for electrostrictive elements 1 and 6, K25...Electrostrictive elements 2 and 5
switching relay.

Claims (1)

[Claims for Utility Model Registration] 1. A plurality of identical electrostrictive element vibrators are arranged, and lead wires connected to the vibrators arranged at symmetrical positions with respect to the center of the array are connected to each of the symmetrical positions. The underwater transducer parts were connected as a set for each set, and each lead wire connected to each set was extended by a cable, and connected to each delay circuit via each switching circuit corresponding to each set. An underwater transceiver device is provided with a delay circuit portion, and is capable of varying the beam width of transmitted and received ultrasonic waves by changing the amount of delay for each of the transducers by switching each of the delay circuits, (a) a multi-frequency vibrator plane array means for arranging each of the vibrators with a vibrator that resonates at a plurality of frequencies, and arranging the wave transmitting/receiving surfaces of the vibrators parallel to each other in a plane, and (b) each of the vibrators as described above. One of the circuits to be switched by the switching circuit is provided with a connection circuit that connects directly to the one input/output terminal for transmitting and receiving waves without intervening the delay circuit, and the circuit to be switched is Input/output circuits including connection circuits connected to the input/output terminals with each of the delay circuits interposed in each of the other circuits other than those in which the vibrator is arranged at the center; c. means for widening the game width beyond the beam width obtained by the arrangement when the beam is not passed through each of the delay circuits, the arrangement of the transducers corresponding to each of the delay circuits being at the center; and a delay circuit configuration means for providing a delay circuit having a delay amount that is sequentially increased toward the outside. 2. The device according to claim 1 of the Utility Model Registration Claim, wherein: (a) each of the vibrators is formed of a rectangular shape with different dimensions on each side, and each side is composed of an electrostrictive element that resonates at a different frequency; , a transducer forming means forming the array with the longest side of each of the sides being parallel, b. After connecting one lead wire of each set into the underwater transducer part, An apparatus characterized by comprising: lead wire connection means leading to each lead wire of the cable; c. switching connection means for configuring the switching connection for the switching by a switching relay. 3. The device according to claim 1 of the utility model registration, which comprises: a) multiple input/output configuration means for configuring the other circuits in the input/output circuit means into multiple sets of circuits; and b) widening the beam width. The means for performing a plurality of sets of circuits in the plurality of input/output means includes a plurality of sets of delay circuits each having a different amount of delay in the delay circuit configuration means. and a plurality of delay configuring means.