Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R1/00—Details of transducers, loudspeakers or microphones
  • H04R1/44—Special adaptations for subaqueous use, e.g. for hydrophone
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
  • H04R9/02—Details
  • H04R9/022—Cooling arrangements

Definitions

• the present invention relates to a sound emitting device immersible or semi-immersible in a liquid.
• FR 2 586 333 operate with electrodynamic loudspeakers.
• the motors of these loudspeakers are generally contained in hermetic packages that can be altered by the pressure exerted by the immersion liquid.
• the transmission frequency band then has a high cut-off frequency.
• the transmission power is determined by the permissible electrical power, which can be of the order of 100W.
• the object of the present invention is to provide a robust acoustic enclosure that can be immersed in a liquid, and more particularly in water, being of moderate cost and being efficient at very low frequencies.
• the device comprises a rigid hollow body having at least one opening at one of its ends and arranged to be at least partially immersed in the liquid, so that the main axis passing through the opening of the hollow body is substantially vertical and at least one electrodynamic loudspeaker comprising at least one membrane, at least one magnet and at least one voice coil.
• the at least one loudspeaker is fixed inside the hollow body near at least one submerged opening of the hollow body, the device and its hollow body being arranged so that when the device is at least semi-immersed , the membrane of the at least one speaker is in contact with the liquid on at least one of its sides and closes the submerged opening of the hollow body.
• the surrounding liquid has a density equal to or greater than 0.9, and more preferably equal to or greater than 0.95, and / or equal to or less than 1.2, and more preferably equal to or less than 1.05 to 20. ° C at the interface with air with a pressure of 1013.25 hPa at 15 ° C.
• the liquid may be, for example, water.
• the device according to the invention is semi-immersible or immersible in water.
• the speaker including the voice coil and the magnet are fully immersed in the surrounding liquid.
• the hollow body may be semi-immersed.
• the device further comprises a floating part arranged outside the hollow body.
• the floating part is a circular body surrounding the hollow body, the circular body being of floating material.
• the speaker is fixed inside the hollow body near the upper opening, and when the device is fully immersed in the liquid, air is contained within the body hollow.
• the speaker coil is arranged in a protection chamber, the protection chamber being formed by a flexible membrane, and a wall of the hollow body.
• the device comprises two loudspeakers arranged along the main axis of the hollow body and forming a chamber with their membranes and the wall of the hollow body, the chamber being filled with a pressure compensation fluid.
• one of the loudspeakers may be an active loudspeaker comprising a membrane and a coil, and the other loudspeaker may be a passive loudspeaker comprising only a membrane.
• the transmission frequency of the speaker (s) is between 1 Hz and 500 Hz.
• the sound pressure level of the loudspeaker (s) can be at least 160 dB (reference lpPa) at 1 m distance from the loudspeaker.
• the speaker may have a motor on each side of the membrane.
• the power of the speaker (s) can be adapted to the pressure of the surrounding liquid in which the device is immersed or semi-immersed.
• FIG. 1 is a schematic view of a first embodiment of a device for transmitting its semi-immersible sound
• FIG. 2 is a schematic view of a second embodiment of a device for transmitting its semi-immersible sound
• FIGS. 3A-3D are schematic views of embodiments of fully immersible sound-emitting devices
• FIGS. 4 and 5 are schematic views of other embodiments of fully immersive sound-emitting devices.
• FIG. 6 is a schematic view of another embodiment of a sound-emitting device.
• FIG. 7 is a schematic view of another embodiment of a sound emitting device.
• variants of the invention comprising only a selection of characteristics described or illustrated isolated from the other characteristics described or illustrated (even if this selection is isolated within a sentence including these other features), if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the state of the prior art.
• This selection comprises at least one preferably functional characteristic without structural details, and / or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention from the state of the art. earlier.
• the sound-emitting device 1 is immersible or semi-immersible in a surrounding liquid.
• the device 1 is semi-immersed in water 2.
• the device 1 comprises a floating hollow body 3, arranged to be at least partially immersed in the surrounding liquid 2 on the side of an immersible end 32 of the body 3.
• the device 1 s' oriente spontaneously so that the main axis 4 of the body 3 is substantially vertical.
• the device 1 is configured so that the center of gravity of the device 1 and the thrust center of the buoyancy pressure are on the main axis 4.
• the center of thrust Archimedes' thrust is directly above the center of gravity (that is, above, on the same vertical axis).
• the hollow body 3 has two openings 34, 35, one at each end 31, 32.
• the main axis 4 of the body 3 passes through the center of these openings.
• the hollow body 3 is made of rigid material and, preferably, of metal, for example stainless steel.
• the hollow body 3 encloses a volume that can have different shapes, for example, cylindrical, parallelepipedal, etc.
• the hollow body 3 is a tube, that is to say a hollow and rigid cylinder.
• the tube 3 used in the example of Figure 1 is equipped with an orifice 33 in the immersible part of the tube 3. This orifice 33 allows the balancing of the liquid levels inside and outside the part immersed tube 3 when it is semi-immersed.
• the device 1 also comprises at least one electrodynamic loudspeaker 5.
• the electrodynamic loudspeaker 5 comprises a membrane 6, a voice coil 7 and a magnet 11, that is to say an electrodynamic motor.
• the magnet 11 is fixedly mounted relative to the hollow body 3.
• the coil 7 is mounted to move relative to the hollow body 3. More precisely, the coil 7 is able to move axially relative to the hollow body 3 parallel to the axis main 4.
• the coil 7 When the speaker 5 is in operation, the coil 7 is traversed by an electric current and tends to move relative to the hollow body 3, along the main axis 4. The displacement of the coil 7 is dependent on the intensity of the current flowing through the coil 7. The displacement of the coil 7 causes a concomitant displacement of the membrane 6.
• the loudspeaker 5 is fixed inside the tube 3 close to the end 32 or immersible opening 35 of the tube 3.
• the loudspeaker 5 and its voice coil 7 are completely immersed in the liquid 2, and the membrane 6 closes the opening 35 of the tube 3 when the device 1 is immersed or semi-immersed. In the embodiment shown in Figure 1, it is the opening 35 at the lower end 32.
• the two opposite faces 63 and 64 of the membrane 6 are in contact with the surrounding liquid 2.
• the edge of the membrane 6 and the lower edge of the tube 3 are flush.
• This arrangement of the loudspeaker 5 with respect to the tube 3 allows a sound emission in the water without the edge of the tube 3 obstructing the propagation of sound waves generated by the movement of the membrane 6.
• the membrane 6 is fixed to the edge of the tube 3 by known means, for example using a flange.
• the membrane 6 of the loudspeaker 5 can also be arranged inside the tube 3, near its lower edge.
• the material of the membrane 6 must be rigid in order to avoid any deformation of the membrane. Such deformation caused a sharp drop in loudspeaker performance due to the destructive interference of pressure waves from different areas of the membrane.
• the membrane may be of a composite material, for example of the sandwich type.
• the membrane may also be aluminum, titanium, steel, honeycomb material or plastic, or any other material suitable for this purpose.
• the device 1 preferably comprises a floating part 8 to prevent the body 3 from flowing completely into the liquid 2.
• the floating part 8 is fixed to the body 3.
• the floating part 8 may have the form of a circular body pierced at its center to insert the hollow body 3 of the device 1 inside thereof, as shown in Figure 1.
• the floating part 8 may be, for example, in wood or any other material floating in the liquid 2.
• the piece floating 8 can be fixed all around or partially around the body 3 so that when the device 1 is semi-immersed in the liquid, the speaker 5 and its voice coil 7 are fully immersed in the liquid. Any mechanism or apparatus adapted to float the device in the liquid may be used. One can use a float.
• Figure 2 schematically shows a second embodiment of the device 1. The description of the parts identical to the embodiment of Figure 1 is omitted.
• the device 1 comprises two loudspeakers 51, 52 arranged along the axis 4 of the tube 3.
• the first loudspeaker 51 comprises a first membrane 61 and a first coil 71.
• the second loudspeaker 52 comprises a second membrane 62 and a second coil 72.
• the two membranes 61 and 62 define with the wall of the tube 3 a closed chamber 10.
• the coils 71, 72 are located inside the chamber 10.
• the chamber 10 and formed is filled with a pressure compensation fluid. This compensation fluid may be, for example, pressurized air or sterilized water.
• the pressure inside the chamber 10 is substantially the same as outside the tube 3 at the level of the loudspeakers 51, 52; it is regulated by communicating vessels as a function of the immersion depth of the tube 3.
• the second embodiment makes it possible to protect the coils from any pollution or dirt. Therefore, the maintenance of such a device 1 is facilitated and its extended life, especially untreated water.
• the two loudspeakers 51, 52 are active loudspeakers, that is to say loudspeakers each comprising a diaphragm 61, 62 and an electrodynamic motor including a coil. 71, 72 as defined above.
• the forces of two speakers add up.
• two loudspeakers of moderate force for example, up to 200 N each
• one very powerful loudspeaker for example, 400 N.
• one of the loudspeakers 51, 52 may be an active loudspeaker.
• the other of the speakers 51, 52 may be a passive speaker, that is to say comprising only the membrane.
• the arrangement of the loudspeaker in the device 1 according to the embodiments described with reference to FIGS. 1 and 2 makes it possible to effectively decouple the wave from its front of the loudspeaker 5 and the wave from its back, in using the characteristic impedance differences between the air and the surrounding liquid without hindering the displacement of the membrane. Therefore, very low frequencies can be emitted.
• Figures 3A to 3D schematically show other embodiments of the device 1, in which the device 1 is fully immersible in a liquid. The description of the parts identical to the embodiments of FIGS. 1 and 2 is omitted.
• the device 1 when the device 1 is immersed in the surrounding liquid 2, the device 1 is oriented spontaneously so that the main axis 4 of the hollow body 3 is vertical and the speaker 5 is placed at the top
• the device 1 is immersed in the liquid 2 so that the air contained inside the hollow body 3 is compressed at the pressure of the surrounding liquid 2 surrounding the device 1.
• the membrane 6 of the speaker 5 is exposed to equal pressure on both sides of the membrane 6 which then remains in the neutral position.
• One of the faces of the membrane 6 is in contact with the surrounding liquid and the other of the faces of the membrane 6 is in contact with the air contained in the hollow body 3.
• the difference in impedance characteristic of the surrounding liquid and air prevents the phase opposition when the membrane 6 is moved by the coil 7.
• the coil 7 of the loudspeaker 5 is inside the device 1.
• FIG. 3B is a variant of the example of Figure 3A, wherein the motor 7 of the speaker 5 is surrounded by a coolant 16 contained in a flexible and expandable pocket 17.
• the flexible bag 17 is a bladder with an accordion deformation mechanism. The flexible bag 17 forms a protection chamber 15 around the coil 7 and allows the moving parts of the loudspeaker 5 to move, the cooling liquid 16 being incompressible.
• the coil 7 of the loudspeaker 5 is outside the device 1. More precisely, the coil 7 is fixed to the face of the membrane 6 in contact with the surrounding liquid 2.
• the example of Figure 3D is a variant of the example of Figure 3C, wherein the speaker 5 does not flush the edge of the body 3 but is slightly inside thereof.
• the upper end 31 of the body 3 is closed by a flexible membrane 9.
• This membrane 9 may be, for example, polyester, such as the product Mylar ⁇ sold by the company Dupont.
• the protection chamber 91 thus formed between the flexible membrane 9 and the loudspeaker contains a sterile cooling liquid, for example, distilled water.
• the coil 7 is then protected from possible contaminations and cooled at the same time.
• the device according to the example of FIG. 3C is preferably usable in a sterile liquid (such as chlorinated water) in order to avoid micro-organic contamination of the coil 5.
• the device does not include a pressure balancing bag.
• the fluid contained in the cavity 37 of the hollow body 3 for example air
• the surrounding liquid 2 for example water
• the air is trapped in the cavity 37.
• the amount of air contained in the cavity 37 remains constant.
• surrounding liquid 2 i.e., water
• the fluid contained inside the cavity 37 i.e., ai r
• the fluid contained inside the cavity 37 is com plied until a pressure equal to the pressure of the surrounding liquid 2 is reached.
• the circulation of the surrounding liquid 2 through the second opening of the hollow body 3 has the effect of moving the air / water interface to the inside of the cavity 37.
• the two faces of the mem Brane 6 of the loudspeaker 5 are permanently subjected to identical pressures.
• the pressure equilibrium is of a natural nature, in that no fluid injection device is required.
• the device 1 is immersed in the surrounding liquid 2, the device 1 is oriented spontaneously so that the main axis 4 of the hollow body 3 is vertical and the loudspeaker 5 is placed at the bottom of the hollow body 3 of the device 1
• the description of the parts identical to the embodiments of the preceding figures is still omitted.
• the hollow body 3 is closed by a deformable part 14.
• the deformable part is a bladder 14 with an accordion deformation mechanism.
• the deformable part 14 can also be a flexible and extensible membrane.
• the protection chamber 13 formed inside the hollow body 3 between the bladder 14 and the loudspeaker 5 is filled with air.
• the chamber 13 may also contain a sterile liquid 12 for cooling.
• the two opposite faces of the membrane 6 are in contact with the liquid.
• the bladder 14 deforms as a function of the pressure of the liquid, including air in the chamber 13.
• the speaker 5 is then exposed at equal pressure on both sides of the membrane 6. This embodiment allows a significant variation in the depth of immersion while maintaining equi-pressure on both sides of the membrane 6 and therefore good performance of the device 1.
• the hollow body 3 of the device 1 is closed at its upper end 31 by a rigid wall (for example of the same type as the lateral wall). hollow body 3).
• the protection chamber 13 formed inside the hollow body 3 is filled with air.
• the chamber 13 also contains a sterile liquid 12 for cooling. The amount of this liquid 12 is determined by the immersion depth of the device 1, the immersion depth being predetermined and relatively low for this embodiment.
• the two opposite faces of the membrane 6 are in contact with liquid.
• the device 1 according to the embodiments of FIGS. 3A to 3D, 4 and 5 has the advantage of being easily achievable and of being of low cost. It allows to be used at different depths of total immersion because its arrangement reduces the stresses on the membrane. Advantageously, its yield is very high.
• FIG. 6 is a schematic view of another embodiment of a sound emitting device 1.
• the sound-emitting device 1 comprises a hollow body 3, a loudspeaker 5 and a pressure-balancing bag 14.
• the hollow body 3 comprises a side wall 36, for example a cylindrical side wall 36 delimiting an internal cavity 37.
• the internal cavity 37 is filled with a fluid such as air or water.
• the hollow body 3 has a main axis 4.
• the side wall 36 has a cylindrical shape of revolution and the main axis 4 is the axis of revolution of the side wall 36.
• the body hollow 3 comprises a first opening 34 (or upper opening) and a second opening 35 (or lower opening).
• the first opening 34 is circular in shape.
• the second opening 35 is also circular in shape.
• the main axis 4 passes through the center of the first opening 34.
• the main axis 4 also passes through the center of the second opening 35.
• the loudspeaker 5 is disposed inside the hollow body 3.
• the loudspeaker 5 comprises a membrane 6, a voice coil 7 and a magnet 11.
• the membrane 6 is fixed to the hollow body 3 so that it obturates the first opening 34.
• the membrane 6 has a symmetrical shape of revolution about the main axis 4.
• the membrane 6 has a first face 63 and a second face 64, opposite the first face 63.
• the first face 63 is in contact with the surrounding liquid 2 while the second face 64 of the membrane 6 is in contact with the fluid contained in the internal cavity 37 of the hollow body 3.
• the mantle 11 is fixedly mounted relative to the hollow body 3.
• the bobi 7 is movably mounted relative to the hollow body 3.
• the coil 7 is adapted to move axially relative to the hollow body 3 parallel to the main axis 4.
• the bobi 7 is traversed by an electric current and tends to move relative to the hollow body 3 along the main axis. pal 4.
• the movement of the bobi 7 is dependent on the i nte
• the displacement of the coil 7 causes a concomitant movement of the membrane 6.
• the pressure equalizing pocket 14 It is located inside the hollow body 3.
• the pressure equalizing pocket 14 comprises a flexible membrane 17 capable of containing a pressure compensation fluid.
• the pressure compensation fluid is a liquid identical to the surrounding liquid 2.
• the pressure equilibration pouch 14 closes the second opening 35. In this way, the amount of fluid contained in the cavity 37 of the hollow body 3 is constant.
• the flexible membrane 17 forming the pressure equilibrium pocket 14 is adapted to deform under the effect of a pressure variation of the surrounding liquid 2. More precisely, when the pressure of the surrounding liquid 2 increases, the volume increases. the pocket 14 increases and the pocket 14 fills with liquid. Surrounding liquid enters the pocket 14 via the second opening 35. In this way, the fluid contained in the interior of the cavity 37 is compressed until it reaches a pressure equal to the pressure of the surrounding liquid 2.
• the deformation of the flexible membrane 17 generates a circulation of the pressure compensation fluid through the second opening 35 so that the two faces 63 and 64 of the membrane 6 of the loudspeaker 5 are permanently subjected to identical pressures. .
• Pressure balancing is done in a natural way, in the sense that no compensation fluid injection device is needed.
• the device 1 When the device 1 is immersed in the surrounding liquid 2, the device 1 is spontaneously oriented in a stable equilibrium position.
• the main axis 4 In the stable equilibrium position, the main axis 4 is vertical and the first opening 34 is located above the second opening 35.
• This orientation has the advantage that the membrane 6 of the loudspeaker 5 is subjected to the same hydrostatic pressure axisymmetrically about the main axis 4.
• FIG. 7 is a schematic view of another embodiment of a sound emitting device 1.
• the sound-emitting device 1 comprises a hollow body 3, a loudspeaker 5 and a pressure-balancing bag 14.
• the hollow body 3 and the loudspeaker 5 are identical to the hollow body 3 of the embodiment of FIG. 6.
• the pressure balancing bag 14 is situated outside the hollow body 3.
• the pressure balancing bag 14 comprises a flexible membrane 17 adapted to contain a pressure compensation fluid.
• the device 1 further comprises a fluid circulation duct 18 connecting the bag at the second opening 35.
• the pressure compensation fluid is a fluid identical to the fluid contained in the cavity 17 of the hollow body 3, that is to say - say air or water.
• the total amount of fluid contained in the cavity 17 of the hollow body 3 and in the pressure balancing bag 14 is constant.
• the pressure balancing bag 14 is arranged with respect to the hollow body 3 so that it is situated in the surrounding liquid 2, substantially at the same depth P as the membrane 6 of the speaker 5. This arrangement makes it possible to ensure a balancing of the pressures exerted on the two faces 63 and 64 of the membrane 6.
• the flexible membrane 17 forming the pressure balancing bag 14 is able to deform under the effect of a pressure variation of the surrounding liquid 2. More specifically, when the pressure of the surrounding liquid 2 increases, the volume of the pocket 14 decreases and the pocket 14 is empty of the fluid it contains. The fluid flows from the pressure equalization pocket 14 via the circulation conduit 18 to the cavity 37 of the hollow body 3, and penetrates inside the cavity 37 of the hollow body 3 via the second opening 35. in this way, the fluid contained inside the cavity 37 is compressed until it reaches on the face 64 of the membrane 6 a pressure equal to the pressure of the surrounding liquid 2 acting on the face 63 of the membrane 6.
• the deformation of the flexible membrane 17 generates a circulation of the pressure compensation fluid through the second opening 35 so that the two faces 63 and 64 of the membrane 6 of the loudspeaker 5 are permanently subjected to identical pressures.
• Pressure balancing is done in a natural way, in the sense that no compensation fluid injection device is needed.
• the device 1 When the device 1 is immersed in the surrounding liquid 2, the device 1 is spontaneously oriented so that the main axis 4 is vertical and the first opening 34 is located above the second opening 35.
• This orientation has the advantage that the membrane of the loudspeaker is subjected to the same hydrostatic pressure axisymmetrically about the main axis 4.
• the immersion in a liquid of the loudspeaker 5 has the advantage of allowing a very efficient cooling of the electrodynamic motor of the loudspeaker by the liquid surrounding the engine.
• the device 1 according to the invention is semi-immersible in seawater.
• the device 1, when it is semi-immersed, can then advantageously be used for the repulsion of predatory fish.
• the transmit frequency band must be between about 40 Hz and 500 Hz. These frequency bands are perfectly attainable with electrodynamic loudspeakers.
• device 1 can be used to move sea bream away from shellfish farms to avoid predation by sea bream of mussel and oyster culture.
• the sound emitted by the device 1 makes escape the predatory fish without harming their physical integrity.
• the loudspeaker whose sound pressure level delivered in water is greater than 160dB to lm (reference lpPa) can be effective in repelling predatory fish.
• Such a device 1 may have a range of about 300 m.
• several devices 1 according to the invention can be arranged immersed or semi-immersed and spaced so that the entire park is covered by sound emissions at the level required during operation of the devices.
• Another possible application of the device according to the invention is the emission of pleasant sounds in swimming pools or recreational.
• the power of the latter must be adapted to compensate for the loss of radiation with the variation of the pressure of the liquid.
• the loudspeaker of the device may also include an electrodynamic motor on each side of the membrane. This arrangement makes it possible to double the force factor by using only one loudspeaker.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• Details Of Audible-Bandwidth Transducers (AREA)

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Family Cites Families (10)

• 2017
  • 2017-08-31 FR FR1758038A patent/FR3070567B1/fr active Active
• 2018
  • 2018-08-31 EP EP18759139.1A patent/EP3677051B1/de active Active
  • 2018-08-31 US US16/643,335 patent/US11095977B2/en active Active
  • 2018-08-31 WO PCT/EP2018/073506 patent/WO2019043178A1/fr unknown

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