JPH0517560B2 - - Google Patents
Info
- Publication number
- JPH0517560B2 JPH0517560B2 JP62016206A JP1620687A JPH0517560B2 JP H0517560 B2 JPH0517560 B2 JP H0517560B2 JP 62016206 A JP62016206 A JP 62016206A JP 1620687 A JP1620687 A JP 1620687A JP H0517560 B2 JPH0517560 B2 JP H0517560B2
- Authority
- JP
- Japan
- Prior art keywords
- sound
- ship
- sound source
- noise
- sound receiving
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 claims description 11
- 230000002452 interceptive effect Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 241000251468 Actinopterygii Species 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000009977 dual effect Effects 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 239000012774 insulation material Substances 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Landscapes
- Details Of Measuring And Other Instruments (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、船底等における水中雑音低減方法
に係わり、更に詳しくは船底に設けられた受音点
（整流覆い内に設けられた魚探知器、測深儀、通
話機等）に入る妨害音源（プロペラ等）からの雑
音を低減させる水中雑音低減方法に関するもので
ある。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for reducing underwater noise on the bottom of a ship, etc. The present invention relates to an underwater noise reduction method for reducing noise from interfering sound sources (propellers, etc.) entering a sounding instrument, a sounding instrument, a telephone, etc.
一般に、船底に於ける雑音は主としてプロペラ
の雑音であり、このプロペラ雑音は高速時（レベ
ルは速度の５乗に比例する。）において、船底に
設けられた受音点（整流覆い内に設けられた魚探
知器、測深儀、通話機等）に於ける機器類の性能
を著しく低下させている。
In general, the noise on the bottom of a ship is mainly propeller noise, and this propeller noise is generated at a sound receiving point installed on the bottom of the ship (installed inside the rectifier cover) at high speeds (the level is proportional to the fifth power of the speed). This has significantly degraded the performance of equipment (fish finders, sounding instruments, telephones, etc.).
そこで、従来ではプロペラの雑音を低減するた
めにプレリーの方法等がとられている。 Therefore, in the past, Prairie's method and the like have been used to reduce propeller noise.
このプレリーの方法とは、船尾側に設けられた
プロペラの羽に、シヤフト内に形成されたエア噴
出通路と連通する複数のエアー噴出孔を設け、プ
ロペラの回転時にコンプレツサから圧縮空気を送
り出すと共に、プロペラの羽に設けられたエアー
噴出孔から小さい気泡を水中に放出させることよ
り、プロペラからの妨害騒音波の発生の抑制及び
吸収、反射等によつてプロペラからの雑音を低減
させる方法である。 Prairie's method involves providing a propeller blade installed on the stern side with a plurality of air jetting holes that communicate with air jetting passages formed in the shaft, and sending out compressed air from a compressor when the propeller rotates. This is a method of reducing noise from the propeller by emitting small air bubbles into the water from air holes provided in the propeller blades, and by suppressing the generation of disturbing noise waves from the propeller, absorbing them, reflecting them, etc.
然しながら、上記の方法はプロペラ軸をも含め
た大規模な方法であり、既設船舶に実施する場合
には構造が複雑である上、多大な費用を必要と
し、また簡単に実施することはできないという問
題があつた。 However, the above method is a large-scale method that includes the propeller shaft, and when applied to an existing ship, the structure is complex, it requires a large amount of cost, and it is not easy to implement. There was a problem.
この発明は、かかる従来の問題点に着目して案
出されたもので、その目的とするところは受音部
と妨害音源とを結ぶ直線波及び受音点に到る船底
反射波の船底面の反射点に、反射板を貼付けて位
相反転反射面にすることにより、簡単でかつ安価
に使用出来ると共に、妨害音源からの雑音を有効
に低減することが出来る水中雑音低減方法を提供
するものである。
This invention was devised by paying attention to such conventional problems, and its purpose is to transmit straight waves connecting the sound receiving section and the disturbing sound source and the reflected waves from the bottom of the ship that reach the sound receiving point to the bottom of the ship. To provide an underwater noise reduction method that is simple and inexpensive to use and can effectively reduce noise from interfering sound sources by attaching a reflector to the reflection point of the vessel to form a phase-inverting reflection surface. be.
この発明は上記目的を達成するため、船底に設
けられた受音点と妨害音源との間において、前記
受音点と妨害音源とを結ぶ直線波及び受音点に到
る船底反射波の船底面の反射点に、妨害雑音波に
対する反射板を貼付けて位相反転反射面としたこ
とを要旨とするものである。
In order to achieve the above-mentioned object, the present invention provides a method for transmitting straight waves connecting the sound receiving point and the disturbing sound source and reflected waves from the bottom of the ship to the sound receiving point between the sound receiving point provided on the bottom of the ship and the disturbing sound source. The gist of this is that a reflecting plate for interference noise waves is attached to the reflection point of the surface to form a phase-inverting reflecting surface.
以下添付図面に基いて、この発明の実施例を説
明する。
Embodiments of the present invention will be described below based on the accompanying drawings.
第１図はこの発明を実施した船舶の側面図、第
２図は第１図の側面図を示し、船舶１の水平な船
底１ａには、その船首側には、金属、ゴム、
FRP等の整流覆い２（ドーム）で覆われた受音
部３（ソーナー送受波器、魚探知器、測深儀、通
話機等）が装備され、また船尾側には妨害音源４
（プロペラ）が装備され、この受音部３と妨害音
源４とは略水平位置にある。 FIG. 1 is a side view of a ship in which the present invention is implemented, and FIG. 2 is a side view of FIG.
It is equipped with a sound receiver 3 (sonar transducer, fish finder, sounding device, telephone, etc.) covered with a rectifier cover 2 (dome) made of FRP, etc., and an interfering sound source 4 on the stern side.
(propeller), and the sound receiving section 3 and the disturbing sound source 4 are located in a substantially horizontal position.
前記受音部３と妨害音源４との間の船底１ａに
は、受音部３と妨害音源４とを結ぶ直線波Qa及
び受音部３に到る船底反射波Qbの船底面の反射
点Ｘに、雑音波の反射板５を貼付けて、位相反転
反射面としている。 On the bottom 1a between the sound receiving section 3 and the disturbing sound source 4, there is a reflection point on the bottom surface of the straight wave Qa connecting the sound receiving section 3 and the disturbing sound source 4 and a bottom reflected wave Qb reaching the sound receiving section 3. A noise wave reflection plate 5 is attached to X to form a phase inversion reflection surface.
前記船底面の反射点Ｘに設ける反射板５の長さ
は、音波長の２倍以上が好ましく、これ以下の場
合には雑音波を有効に低減することは難しい。従
つて、音源に広がりがある場合は、それに見合つ
た長さとなる。 The length of the reflection plate 5 provided at the reflection point X on the bottom surface of the ship is preferably at least twice the length of the sound wave, and if it is less than this length, it is difficult to effectively reduce the noise waves. Therefore, if the sound source has a spread, the length will be commensurate with that.
前記位相反転反射面に設けた反射板５は、第７
図及び第８図に示すように、音響ゴムを素材とし
て、300mm×300mm角の成形ゴム１２を成形し、そ
の一側面には仕切り壁１３により区画された複数
の凹状に形成された空気層１４が形成されてい
る。 The reflecting plate 5 provided on the phase inversion reflecting surface has a seventh
As shown in the figure and FIG. 8, a 300 mm x 300 mm square molded rubber 12 is formed using acoustic rubber as a material, and one side of the molded rubber 12 has a plurality of concave air spaces 14 separated by partition walls 13. is formed.
そして、その表面側は音響ゴムを素材としてカ
バーゴム１６が気密的及び水密的に装着されてい
る。 A cover rubber 16 made of acoustic rubber is airtightly and watertightly attached to the front side of the cover.
また第９図及び第１０図の場合には、前記空気
層１４に、連続気泡または独立気泡の空気層を備
えたスポンジを素材とした遮音材１５を埋設した
もので、その表面側は音響ゴムを素材としたカバ
ーゴム１６が気密的及び水密的に装着されてい
る。このように、成形ゴム１２に形成された凹状
の空気層１４を密閉したり、遮音材１５を埋設す
ると共に、カバーゴム１６により密閉することに
より遮音効果を高めることが出来るのである。 In the case of FIGS. 9 and 10, a sound insulating material 15 made of sponge and having an open-cell or closed-cell air layer is embedded in the air layer 14, and the surface side of the sound insulating material 15 is made of acoustic rubber. A cover rubber 16 made of is attached airtightly and watertightly. In this way, the sound insulation effect can be enhanced by sealing the concave air layer 14 formed in the molded rubber 12, embedding the sound insulation material 15, and sealing it with the cover rubber 16.
即ち、媒質中を伝播する音波は、固有音響イン
ピーダンス（物質密度ρ×音速ｃ）を異にする物
質との境界面においては反射し、透過を減少する
ものである。 That is, a sound wave propagating in a medium is reflected at an interface with a material having a different characteristic acoustic impedance (material density ρ×sound velocity c), and its transmission is reduced.
この性質を利用し、水のρ0，c0と著しくρ，ｃ
を異にする空気層を、遮音を必要とする面に装備
させることにより、遮音効果を高め、また薄層化
も可能となる。 Utilizing this property, the ρ 0 , c 0 of water and the ρ , c
By equipping surfaces that require sound insulation with air layers of different levels, it is possible to increase the sound insulation effect and also make the layer thinner.
ここで、水のρ0，c0に対して、遮音材をρ，ｃ
とすれば、ρ0c0＞ρcの場合、音響的に柔らかいも
のとなり、空気層がこれに相当する。この場合の
反射の際に、音波の位相が反転する。 Here, for water ρ 0 , c 0 , the sound insulation material is ρ , c
If ρ 0 c 0 > ρc, the sound is acoustically soft, and the air layer corresponds to this. Upon reflection in this case, the phase of the sound wave is reversed.
またρ0c0＜ρcの場合、音響的に硬いものとな
り、鋼板等がこれに相当する。この場合の反射の
際は、位相は反転しないので利用できない。 When ρ 0 c 0 <ρc, the material is acoustically hard, such as a steel plate. In this case, the reflection cannot be used because the phase is not reversed.
ここで、船底１ａに反射板５を装着した場合、
第１図の受音部３から見た妨害音源４とその鏡像
４′とは正負二重音源となり、正負二重音源の指
向性は、次の式で求めることが出来る。 Here, when the reflector 5 is attached to the bottom 1a of the ship,
The interfering sound source 4 and its mirror image 4' viewed from the sound receiving section 3 in FIG. 1 form a positive and negative dual sound source, and the directivity of the positive and negative dual sound source can be determined by the following equation.
指向性係数をＲ、波長定数をｋとすれば、
Ｒ＝sin（kd sinθ）
この実施例では、第１図においてｄ＝0.5ｍ，
ｈ＝1.25ｍとした場合、θ＝1.2となり、
第３図のように受音部３に到来する音圧は低減
する。 If the directivity coefficient is R and the wavelength constant is k, then R=sin(kd sinθ) In this example, in Fig. 1, d=0.5m,
When h=1.25m, θ=1.2, and the sound pressure reaching the sound receiving section 3 is reduced as shown in FIG.
次に、第４図〜第６図はこの考案の第２実施例
を示している。 Next, FIGS. 4 to 6 show a second embodiment of this invention.
妨害音源４であるプロペラは、一般に船底１ａ
のキール線より上方にあつて、受音部（整流覆
い）からは見えない位置になる。然し、妨害音源
４の雑音は、図のように回析して受音部３に到達
する。船底１ａの形状から考えて、回析による損
失は少ないものと考えられ、この回析波に対する
低減方法としては、第５図及び第６図のようにな
る。 The propeller, which is the disturbance sound source 4, is generally located at the bottom 1a of the ship.
It is located above the keel line and cannot be seen from the sound receiving section (rectifier cover). However, the noise from the interfering sound source 4 is diffracted and reaches the sound receiving section 3 as shown in the figure. Considering the shape of the bottom 1a, it is thought that the loss due to diffraction is small, and the method of reducing this diffraction wave is as shown in FIGS. 5 and 6.
即ち、第５図において仮想面Ａを考え、妨害音
源４による仮想面上の音圧分布を計算し、仮想面
Ａの音圧分布を新たな妨害音源と考えて、受音部
３に対する音波伝搬を考慮する。 That is, considering the virtual surface A in FIG. 5, the sound pressure distribution on the virtual surface due to the disturbing sound source 4 is calculated, and the sound pressure distribution on the virtual surface A is considered as a new disturbing sound source, and the sound wave propagates to the sound receiving section 3. Consider.
そして、第６図に示すように、船底１ａの屈曲
点付近Ｘ１に、上記実施例と同様な音圧反転反射
板５を装着すれば、仮想線Ａの音圧レベルは低下
し、回析波を低減することが出来る。 Then, as shown in FIG. 6, if a sound pressure inverting reflector 5 similar to the above embodiment is installed near the bending point X1 of the bottom 1a, the sound pressure level of the virtual line A will decrease, and the diffraction wave can be reduced.
なお、必ずしも必要はないが仮想線Ａと受音部
３との間の音波の伝搬経路に同様な反射板５を設
ければ、雑音の低減を更に有効に行うことが出来
る。 Note that, although it is not necessary, if a similar reflecting plate 5 is provided on the propagation path of the sound wave between the virtual line A and the sound receiving section 3, noise can be reduced more effectively.
この発明は、上記のように船底に設けられた受
音部と妨害音源との間において、前記受音部と妨
害音源とを結ぶ直線波及び受音部に到る船底反射
波の船底面の反射点に、妨害雑音波に対する反射
板を貼付けて位相反転反射面とし、プロペラから
の雑音を低減するようにしたもので、簡単でかつ
安価に使用出来ると共に、妨害音源からの雑音を
有効に低減することが出来る効果がある。
As described above, between a sound receiving section provided on the bottom of a ship and a disturbing sound source, the straight waves connecting the sound receiving section and the disturbing sound source and the reflected waves from the bottom of the ship reaching the sound receiving section are transmitted to the bottom surface of the ship. A reflector for interfering noise waves is pasted on the reflection point to create a phase-inverting reflection surface to reduce noise from the propeller.It is simple and inexpensive to use, and effectively reduces noise from the interfering sound source. There is an effect that can be done.
第１図はこの発明を実施した船舶の側面図、第
２図は第１図の側面図、第３図はこの発明の反射
板と鉄板とを比較した場合のグラフ説明図、第４
図は他の実施例の示す船舶の側面図、第５図はこ
の実施例の原理図、第６図は反射板の取りつけ状
態を示す説明図、第７図は位相反転反射板の平面
図、第８図は第７図の−線に沿う断面図、第
９図は他の位相反転反射板の平面図、第１０図は
第９図の−線に沿う断面図である。
１…船舶、１ａ…船底、２…整流覆い、３…受
音部、４…妨害音源、５…反射板。
Fig. 1 is a side view of a ship in which this invention is implemented, Fig. 2 is a side view of Fig. 1, Fig. 3 is a graph explanatory diagram comparing the reflector plate of this invention and an iron plate, and Fig. 4
The figure is a side view of a ship showing another embodiment, FIG. 5 is a principle diagram of this embodiment, FIG. 6 is an explanatory diagram showing how the reflector is attached, and FIG. 7 is a plan view of the phase inversion reflector. 8 is a sectional view taken along the - line in FIG. 7, FIG. 9 is a plan view of another phase inversion reflector, and FIG. 10 is a sectional view taken along the - line in FIG. 9. DESCRIPTION OF SYMBOLS 1... Ship, 1a... Bottom of ship, 2... Rectifier cover, 3... Sound receiver, 4... Disturbing sound source, 5... Reflector.
Claims (1)
おいて、前記受音点と妨害音源とを結ぶ直線波及
び受音点に到る船底反射波の船底面の反射点に、
妨害雑音波に対する反射板を貼付けて位相反転反
射面としたことを特徴とする水中雑音低減方法。1. Between a sound receiving point provided on the bottom of the ship and a disturbing sound source, a straight wave connecting the sound receiving point and the disturbing sound source and a reflection point on the bottom of the ship of the bottom reflected waves reaching the sound receiving point,
An underwater noise reduction method characterized by attaching a reflecting plate for interference noise waves to form a phase-inverting reflecting surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62016206A JPS63184796A (en) | 1987-01-28 | 1987-01-28 | Underwater noise reduction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62016206A JPS63184796A (en) | 1987-01-28 | 1987-01-28 | Underwater noise reduction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63184796A JPS63184796A (en) | 1988-07-30 |
| JPH0517560B2 true JPH0517560B2 (en) | 1993-03-09 |
Family
ID=11910038
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62016206A Granted JPS63184796A (en) | 1987-01-28 | 1987-01-28 | Underwater noise reduction |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63184796A (en) |
-
1987
- 1987-01-28 JP JP62016206A patent/JPS63184796A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63184796A (en) | 1988-07-30 |
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