JPH06100650B2 - Baffle for sonar - Google Patents

Description

TECHNICAL FIELD The present invention relates to a baffle in which a transducer is fixedly supported in a sonar.

[Conventional technology]

The transducer used in a sonar needs to avoid the influence of unnecessary sound pressure in order to obtain a predetermined characteristic. Therefore, when the sonar is constructed, it is usually baffled so that the transducers are arranged in a predetermined arrangement. It adheres to and supports it.

Two types of conventional baffles, soft type and hard type, are known. As the soft type baffle, for example, a small air chamber sealed with a rubber material such as neoprene is known. ing.

This aims at the perfect soft reflection of unnecessary sound pressure incident on the baffle by utilizing the property of air whose acoustic impedance is extremely lower than that of water.

Further, the hard type baffle is configured by using a rigid material such as metal, which is the opposite of the soft type baffle, and has a higher acoustic impedance than water,
It is aimed at rigid reflection.

[Problems to be solved by the invention]

However, the conventional two types of baffles described above each have the following problems.

In other words, the soft type baffle reduces the air chamber when water pressure is applied, and as a result, the acoustic impedance approaches water and the sound permeability is good, so the baffle function is significantly reduced, and therefore under high water pressure. There is a problem that it can not be used in.

On the other hand, the hard type baffle needs to have a sufficiently large plate thickness when it has an acoustic impedance sufficiently higher than that of water, so that it becomes very heavy in order to be usable even at low frequencies. There is.

The present invention has been made to solve these problems, and an object thereof is to realize a novel baffle for a sonar which can be used under high water pressure and is lightweight and has a sufficient baffle function.

[Means for solving problems]

In order to achieve this object, a sonar baffle of the present invention comprises a water resistant shell made of a rigid material having an outer peripheral surface as a mounting surface for mounting a transducer, and a sealed air chamber formed by the water resistant shell. And is provided.

[Action]

In the present invention having the above-mentioned configuration, of the sound pressure incident on the baffle, the high-frequency sound pressure is reflected by the water pressure resistant shell, and the low frequency sound pressure transmitted through this water resistant pressure shell is converted into It can be completely reflected by the air in the air chamber.

Therefore, according to this, by using the water pressure resistant shell, the air chamber is not reduced by the water pressure, so that it can be used under high water pressure, and the water pressure resistant shell is made of metal, Since it is not necessary to increase the plate thickness, it becomes lighter,
Moreover, as described above, since the sound pressure can be completely reflected by the water pressure resistant shell and the air chamber, a sufficient bubbling function can be obtained.

〔Example〕

 Embodiments will be described below with reference to the drawings.

FIG. 1 is a front view showing one embodiment of a sonar baffle according to the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a partially enlarged sectional view.

In the figure, 1 is a water pressure resistant shell formed of a rigid material such as resin or metal so as to withstand high water pressure, and 2 is a sealed air chamber formed by this water pressure resistant shell 1 for a sonar of this embodiment. The baffle is composed of the water pressure resistant shell 1 and the air chamber 2.

More specifically, as shown in FIG. 3, the water resistant pressure shell 1 is composed of a cylindrical body 1a and a dome-shaped lid 1b that closes the upper and lower surfaces of the body 1a, and the upper and lower end surfaces of the body 1a. Further, the air chamber 2 is formed by fixing the peripheral portion of the lid 1b so as to seal the inside by an arbitrary method such as welding or bonding.

Reference numeral 3 denotes a wave transmitter / receiver, and the wave transmitter / receiver 3 is fixed to the outer peripheral surface of the water resistant pressure shell 1, more specifically, the outer peripheral surface of the body 1a forming the water pressure resistant shell 1 together with the lid 1b in a predetermined arrangement. A cylindrical sonar array is constructed.

That is, the outer peripheral surface of the water pressure resistant shell 1 is used as a mounting surface of the wave transmitter / receiver 3, and the wave transmitter / receiver 3 is fixed to the mounting surface so as to form a sonar array.

Next, the operation of the above-described structure will be described. First, since the water resistant pressure shell 1 is formed of a rigid material such as metal, the water resistant pressure shell 1 itself reflects a certain amount of incident sound pressure, that is, high frequency sound pressure. can do.

Here, a part of the incident sound pressure, that is, a low-frequency sound pressure is transmitted through the water pressure resistant shell 1, but since the water pressure resistant shell 1 can withstand the high water pressure as described above, the air chamber 2 inside thereof can withstand the water pressure. Therefore, the sound pressure transmitted through the water pressure resistant shell 1 can be completely reflected by the air in the air chamber 2.

FIG. 4 is a diagram showing the sound pressure output frequency characteristics at the wave receiving point of the transducer 3 fixed to the water resistant pressure shell 1 described above. Here, the water resistant pressure shell 1 made of a rigid material having a plate thickness of 40 mm is used. , 31
An example is shown in which the acoustic center of the wave transmitter / receiver 3, that is, the wave receiving point is placed in front of mm.

In this case, the sound pressure reflectance of the sonar baffle consisting of the air chamber 2 of the water pressure resistant shell 1 is almost 1, and the sound pressure transmittance, which is a comparative output compared with the case without baffle, is almost 0, and a perfect sound insulation effect. Is obtained.

In other words, the frequency characteristics of the sonar baffle having the above-described configuration are close to those of the soft type at low frequencies, close to those of the hard type at high frequencies, and the sound pressure reflectance is close to 1 over the entire frequency band. , The sound pressure transmittance is close to 0, and a sufficient bubbling function can be obtained.

The shape and structure of the water pressure resistant shell according to the present invention are not limited to those of the illustrated embodiment, and it goes without saying that the design can be changed as necessary.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention is provided with a water pressure resistant shell made of a rigid material having water pressure resistance with the outer peripheral surface as a mounting surface of a transducer, and a sealed air chamber formed by this water pressure resistant shell. Therefore, the air chamber does not shrink due to water pressure, and it can be used under high water pressure.

In addition, since the water pressure resistant shell does not need to have a large plate thickness like the conventional hard type, it can be configured to be lightweight,
Moreover, since the sound pressure reflection can be performed over the entire frequency band by the water pressure resistant shell and the air chamber, the influence of unnecessary sound pressure on the transmitter / receiver is prevented, and a sufficient baffle function is obtained.

Furthermore, in the present invention, since the water resistant pressure shell contains the air chamber,
It has a large buoyancy in the water, which makes it possible to make the weight of the baffle in the water lighter than that of the conventional soft type, so there is an advantage that it becomes a very advantageous structure as an underwater structure. .

[Brief description of drawings]

1 is a front view showing an embodiment of a sonar baffle according to the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a partially enlarged sectional view of the embodiment of FIG. 1, and FIG. 4 is according to the present invention. It is a figure which shows an example of the sound pressure output frequency characteristic in the wave-receiving point of the wave transceiver attached to the baffle. 1: Water pressure resistant shell, 2: Air chamber, 3: Transducer

Claims (1)

[Claims] 1. A sonar having a water pressure resistant shell made of a rigid material, the outer peripheral surface of which is used as a mounting surface for mounting a transducer, and a sealed air chamber formed by the water pressure resistant shell. Baffle for.