JPS61187677A - Ultrasonic apparatus - Google Patents

Abstract

PURPOSE:To reduce the effect of a noise wave, by refracting the noise wave by buffle. CONSTITUTION:When an ultrasonic apparatus performs the measurement of a signal on a horizontal plane, directionality has max. sensitivity to the horizontal plane. Then, buffle 1 is provided to refract a noise wave A to generate the same effect as the blocking effect of a sonic wave and the effect of the noise wave is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic device that measures the distance and direction of an object in the ocean, or the sound waves generated by an observation object.

[Conventional technology]

Conventionally, this type of ultrasonic device has been provided with a baffle that allows only a small amount of sound wave to pass through in order to block noise sound waves arriving in a specific direction generated by the rotating machine, propeller, etc. of the ship on which the device is mounted.

[Problem that the invention seeks to solve]

While the conventional baffles mentioned above have the property of preventing the transmission of sound waves, they also have the property of reflecting sound waves. Therefore, by reflecting the sound waves generated by the ultrasonic device and giving the ultrasound device a special effect, it reflects the signal sound waves in a direction different from the direction of the noise sound waves, making it appear as if the signal was propagating from a different direction. I misunderstood it as if it were coming.

In order to avoid these effects, the baffle should not be placed close to the ultrasonic device, and should be spaced apart from the baffle or provided with a convex surface on the side facing the ultrasonic device to prevent the sound waves from being scattered.

However, because noise sound waves in water generally have long wavelengths, the diffraction phenomenon is noticeable, and the sound waves penetrate into the ultrasonic device covered with the baffle, reducing the effectiveness of the baffle.

Alternatively, it is necessary to make the baffle even larger in order to reduce the distortion caused by the diffraction phenomenon, which has the disadvantage of increasing the size of the device.

[Means for solving problems]

The ultrasonic device of the present invention refracts noise sound waves using a buckle, and reduces the influence of the refracted noise sound waves using the directivity of the ultrasonic device.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

Fig. wJ1 is an external view of one embodiment of the present invention, and Fig. 2 is a sectional view taken along the line xx' in Fig. wJ1.

Reference numeral 1 is a baffle, made of an acrylic resin material, which is faster than the speed of sound of a sound wave propagating body such as seawater. Due to the difference in sound speed with the propagating body, horizontally incident noise sound waves are refracted and have an angle of depression from the horizontal plane. 2 is a transducer as an ultrasonic device, which is a radiation surface of a medicinal cone. It is omnidirectional in the horizontal direction and is equally sensitive in all directions. It has directivity in the vertical direction and is greatest in the horizontal plane, and sensitivity decreases when there is an angular difference.

The noise sound wave A refracted by the action of the baffle 1 appears to output from the ultrasonic device ff2 at a low level, producing the same effect as blocking sound waves. Since the baffle 1 may transmit sound waves, the degree of reflection from the baffle 1 can be reduced, so even if the baffle 1 is placed close to the transducer 2, its influence is small.

FIG. 3 is an external view of a second embodiment of the present invention.

Two or more receivers 3 are arranged in a straight line perpendicular to the horizontal plane. The receiver is omnidirectional in all directions. The signal from each receiver is input to the signal processor of the ultrasonic device. These signals are given directivity in the vertical direction by a signal processor, and as in the first embodiment, the sensitivity to refracted noise sound waves is reduced, producing the same effect as blocking sound waves.

The ultrasonic devices of the first and second embodiments described above measure signals in directions on a substantially horizontal plane. Therefore, the directivity in the vertical direction is designed to have the maximum sensitivity in the horizontal plane.When measuring at an elevation angle, the maximum sensitivity is at that angle, so the baffle should be placed away from that angle. We decided to refract the noise sound waves. For example, if a noise sound wave comes from a horizontal plane, it is refracted at an angle K opposite to the angle of measurement (elevation angle for depression angle, depression angle for elevation angle). Furthermore, if the noise sound waves arrive at the same angle as the measurement angle, the angle can be changed by refraction, as in the embodiment.

Figure 4 is an external view of the third embodiment, and Figure 5 is the
It is an X/sectional view.

This embodiment has a configuration in which a baffle 4 is added to the previous embodiment. The baffle 4 operates in the same way as a conventional baffle and blocks the transmission of noise sound waves. For example, use foamed resin (with air particles inside).

The baffle 4 is spaced apart from the transducer 2 and has an angle of depression. This is to reduce misidentification due to reflection of sound waves generated by the transducer 2 itself or reflection of signal sound waves. Therefore, as described above, the effect of insulating noise sound waves is reduced due to the diffraction effect. Figure 5 shows the progress of the noise sound waves. The arriving noise sound wave is blocked by the baffle 4, and a portion a of it leaks through transmission and diffraction. The noise sound waves are refracted by the baffle 1 and produce a blocking effect by the action described in the first embodiment. That is, in the third embodiment, a synergistic effect is produced by the effects of the baffles 1 and 4, and the effect of blocking noise sound waves is more complete.

In the above explanation, the shapes of the baffles 1 and 4 are not particularly mentioned, but it may be more effective to form them into three-dimensional curved surfaces in accordance with the directivity of the ultrasonic device. For example, when the transducer l has a circular shape as in the case of the first embodiment, the baffle 1 is not a plate-like member with a tapered surface on the negative side, but a circular baffle of the transducer l. If it is curved along the surface of the surface and brought closer, its effect against noise sound waves due to diffraction becomes more complete.

Furthermore, when the backflush 4 is made to have a curved surface close to a spherical surface, the influence of reflection of the sound generated by the transducer 1 is reduced by scattering. Regarding the material of the baffle, if an acoustic material with sound absorption properties is used on the surface of the transducer 2 of the baffle 4, the amount of reflection will be reduced.

In such a case, it can be moved closer to the transducer 2 to reduce the reduction in the blocking effect due to the frequency f(K).

Calculation of the refraction angle of the baffle l will be explained.

A simple calculation can be performed using the well-known Snell's law. Regarding the baffle l of the first embodiment, its refraction v2 in the relationship between angle and velocity shown in FIG.

The angle Δθ of is Δθ=θ-5in' (-5tne
). In the figure, θ is the taper angle of the baffle, v
i represents the sound speed of the baffle, and v2 represents the sound speed of seawater.

In addition, in the explanation, the angle of refraction refers to the angle of elevation, but it also applies to cases where refraction is performed at left and right angles (declination angle in the horizontal plane) or both angles of elevation and left and right angles. Although this is true in principle, greater effects can sometimes be obtained depending on the directivity of the ultrasonic device.

〔Effect of the invention〕

As explained above, 1) the present invention is capable of obtaining the same effect as blocking noise sound waves by using the NA shuttle; Can be installed close to the baffle. Therefore, it is possible to reduce the reduction in the blocking effect due to the diffraction phenomenon. Furthermore, when combined with a conventional non-transparent baffle, the reflected noise waves can be blocked even if the baffle is moved far enough to allow for the influence of reflection, and the synergistic effect of the two will result in even better blocking results. can be obtained.

[Brief explanation of drawings]

Fig. 1 is an external view of the first embodiment of the present invention, and Fig. 2 is an external view of the first embodiment of the present invention.
3 is an external view of the second embodiment, FIG. 4 is an external view of the third embodiment, and FIG. 5 is a cross-sectional view of the
-x' line cross-sectional view, FIG. 6 is a diagram showing an example of a calculation formula for a refraction angle. 1... Baffle, 2... Transmitter/receiver, 3
...Receiver, 4...Baffle. $1 1!1 Leather 2 Bacteria No. 4 (!l Kaya S Figure

Claims (2)

[Claims] (1) Ultrasonic equipment is equipped with baffles that refract sound waves. 1. An ultrasonic device characterized in that the ultrasonic device is provided opposite to the device. (2) An ultrasonic device characterized in that a first baffle that blocks sound waves and a second baffle that refracts sound waves are juxtaposed to face the ultrasonic device.