EP0462037B1 - Underwater electro-acoustic transducer - Google Patents
Underwater electro-acoustic transducer Download PDFInfo
- Publication number
- EP0462037B1 EP0462037B1 EP91430011A EP91430011A EP0462037B1 EP 0462037 B1 EP0462037 B1 EP 0462037B1 EP 91430011 A EP91430011 A EP 91430011A EP 91430011 A EP91430011 A EP 91430011A EP 0462037 B1 EP0462037 B1 EP 0462037B1
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- European Patent Office
- Prior art keywords
- transducer
- electro
- transducer units
- acoustic
- units
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- 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.)
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Classifications
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
- G10K9/12—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated
- G10K9/121—Flextensional transducers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
- B06B1/0611—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements in a pile
- B06B1/0618—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements in a pile of piezo- and non-piezoelectric elements, e.g. 'Tonpilz'
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49005—Acoustic transducer
Definitions
- the present invention relates to a submerged electro-acoustic transducer and to a method of manufacturing this electro-acoustic transducer.
- Electro-acoustic transducers are commonly used, in particular to emit signals intended for communications and underwater detection.
- the most commonly used electro-acoustic transducers include a motor, or active part, which generally consists of a stack of piezoelectric ceramic alternating with electrodes, the assembly forming a cylinder of elongated shape; under the action of a tension applied to ceramics, they deform; the ceramics are arranged and wired in such a way that their deformations are added, which means that longitudinal contraction and expansion movements of the stack of piezoelectric ceramics are obtained.
- This stack is linked at one of its two longitudinal ends to a generally metallic support piece, serving as a support, often called a counter-support piece or counter-mass, which is kept substantially stationary relative to the transducer housing; the stack is linked at its other end to another mass, sometimes called the pavilion, which vibrates along the longitudinal axis of the stack, due to the movements of the latter, resulting from the tension applied to the ceramics.
- a generally metallic support piece serving as a support, often called a counter-support piece or counter-mass, which is kept substantially stationary relative to the transducer housing
- the stack is linked at its other end to another mass, sometimes called the pavilion, which vibrates along the longitudinal axis of the stack, due to the movements of the latter, resulting from the tension applied to the ceramics.
- This flag is in contact with the desired propagation medium, generally water, in general by means of an elastic coating which seals the transmitter.
- the electro-acoustic transducers of the "TONPILZ" type include the basic mechanical assembly, briefly described above, which includes a counter-mass fixed in a cylindrical case by means of suspensions limiting the movements of the sealed case with respect to this counter-mass, a stack of ceramics piezoelectric which vibrates a pavilion.
- the stack is axially prestressed along its longitudinal axis, by means generally constituted by a rod screwed into the roof, which passes through the stack, which is blocked in the counter-mass by a nut and which is tensioned.
- JANUS type electro-acoustic transducers correspond substantially to two "TONPILZ” type electro-acoustic transducers, having a common counter-mass and whose stacks vibrate in phase opposition.
- Electro-acoustic transducers of the "FLEXTENSIONAL” type use a principle of prestressing and diffusion of vibrations in the somewhat different propagation medium: in this type of electro-acoustic transducers, for example the “FLEXTENSIONAL” of class 4, the housing consists of a shell, generally made of epoxy glass composite, of cylindrical shape with elliptical section; this shell of elliptical section is, due to its elasticity, capable of flattening and rounding; in this shell, symmetrically with respect to a central core extending along the axis of the cylindrical shell, one or more pairs of stacks of piezoelectric ceramics, which rest at one end on metal inserts which extend parallel to the central core, which metal inserts are supported inside the shell, in the vicinity of the end of the major axis of the ellipse defining the shell section.
- EP-A-0 367 681 describes such a transducer.
- the assembly consisting of the stacks and the central counter-mass is introduced into the shell, the latter being prestressed by pinching, along the minor axis of the ellipse; when the assembly is in place inside the shell, the prestress is released, the long axis of the ellipse shortens, which prestresses the assembly, along the longitudinal axis of the stacks.
- transducer elements consist of stacks of piezoelectric ceramics
- these stacks of ceramics can, in certain cases, be replaced by magnetostrictive transducers; these transducers mainly comprise an elongated bar, constructed of a material generally mainly consisting of rare earths, which can vibrate by contracting and expanding along its axis longitudinal, under the effect of a magnetic field created by a coil which surrounds this bar.
- the problem posed is therefore to provide electro-acoustic transducers capable of being submerged, and their manufacturing process, allowing, without appreciable increase in the size of the electro-acoustic transducer, to provide increased power and / or capable of transmit at relatively low frequencies.
- an electro-acoustic transducer comprising in a housing, at least a first support part, or pavilion, and at least a second support part, or counter-mass, comprising at least two transducer elements of elongated shape along a longitudinal axis of said transducer, comprising at least one prestressing rod along said longitudinal axis, between said first and second bearing parts of said transducer elements, such that said transducer elements are arranged side by side side, and / or constitute coaxial cylinders having for axis said longitudinal axis, and can vibrate in phase, and such that it comprises at least one part or assembly, rigid, mobile intermediate, which is mounted or stacked, interposed between said transducer elements, mechanically in series with said transducer elements, so that said rigid intermediate piece can be prestressed by said rod, simultaneously with said transducer elements, and so that said rigid intermediate piece is capable of vibrating in phase with said transducer elements.
- an electro-acoustic transducer comprises at least two transducer elements of elongated shape along a longitudinal axis, located between a first and a second support piece, prestressed along said longitudinal axis by a prestressing device, which tends to bring said support pieces closer together, which transducer elements each have two longitudinal, parallel, planar ends, which transducer elements are parallel, arranged side by side, and operate in phase, the assembly being contained in a housing, and only a first end of a first of said transducer elements is pressed against said first support piece, and only a first end of a second of said transducer elements is pressed against said second support piece, and said transducer comprises a rigid intermediate assembly which is sandwiched between said first and second transducer elements, which has two parallel faces which bear respectively on the second ends of said transducer elements and which is capable of being prestressed simultaneously with said first and second transducer elements, along said longitudinal axis by said prestressing device; each of said
- said rigid intermediate assembly consists of a single rigid metal part, which can for example consist of a substantially cylindrical part, having an axis, parallel to said longitudinal axis, terminated at one end by a bottom which comprises one of said two parallel faces, which is supported on the second end of a first of said transducer elements, and at its other end, by an external flange which comprises the other of said two parallel faces, which rests on the second end of the second of said transducer elements.
- said intermediate assembly comprises at least two rigid intermediate parts and at least one intermediate transducer element which is interposed between said two rigid intermediate parts and arranged mechanically in series therewith.
- said prestressing device comprises one or more rods, which are fixed respectively by each of their two ends to each of said support pieces, or to an intermediate piece, in particular for application to "TONPILZ” and “JANUS” type assemblies, or else is constituted by said case which is deformable, in particular for application to "FLEXTENSIONAL” type assemblies.
- the cross sections of the active parts of said first and second transducer elements are substantially equal.
- a solution to the problem posed is also to provide a method of manufacturing electro-acoustic transducers of the type comprising at least one transducer element of elongated shape, prestressed axially between two support pieces, characterized in that it is mounted between said pieces support, a first transducer element of elongated shape, having only one first end pressed against one of the two support pieces and a second transducer element of elongated shape, having only one first end pressed against the other support piece, which transducer elements are parallel and arranged side by side and operate in phase, interposed between these two transducer elements an intermediate piece which bears on the second ends of said transducer elements, and the two transducer elements and said intermediate piece which transmits the longitudinal forces between the two transducer elements are axially prestressed between the two bearing pieces.
- an electro-acoustic transducer in an electro-acoustic transducer according to the invention, to nest a second stack of ceramics in the form of a crown, which substantially surrounds the first stack, the two stacks having the same height and the active elements having substantially the same section, and an electro-acoustic transducer is thus obtained, the power of which will be substantially doubled compared to known electro-acoustic transducers of the same size, which include that said first stack, since the volume of ceramics is doubled; at the same time, the equivalent length of the fictitious stack thus produced by the two nested stacks is doubled; therefore, the resonant frequency of the nested stack according to the invention, being approximately, inversely proportional to the square root of the length, will therefore be reduced by 40% compared to the known electro-acoustic transducer of the same size.
- the assembly according to the invention can be used so as to nest more than two stacks, without significantly increasing the size of the transducer, which makes it possible to achieve even higher performance in low power and / or frequency.
- the electro-acoustic transducers according to the invention can be constructed both with piezoelectric ceramic transducers and with magnetostrictive bars.
- FIG. 1 represents a cross-sectional view, on a reduced scale, of an embodiment of electro-acoustic transducer according to the invention, in an assembly of the "TONPILZ" type.
- FIG. 2 represents a cross-sectional view, on a reduced scale, of another embodiment.
- FIG. 3 represents a cross-sectional view, on a reduced scale, of an embodiment of electro-acoustic transducer according to the invention, in an assembly of the "JANUS" type.
- FIG. 4 represents a cross-sectional view, on a reduced scale, of an embodiment of electro-acoustic transducer according to the invention, in an assembly of the "FLEXTENSIONAL" type.
- FIG. 5 represents a cross-sectional view, on a reduced scale, of an embodiment of electro-acoustic transducer according to the invention, in a “TONPILZ” type assembly fitted with magnetostrictive transducer elements.
- FIG. 6 is a section on VI-VI of FIG. 5.
- FIG. 1 there is shown an electro-acoustic transducer according to the invention which is equipped with two transducer elements made of piezoelectric ceramics, in an assembly of the "TONPILZ" type.
- the electro-acoustic transducer comprises in this type of mounting, a metal housing 3, a counterweight 2, a horn 1, a prestressing rod 4 and a locking nut 5.
- said housing 3 is closed at one end by a cover 13, in leaktight manner thanks to a seal 14.
- Said counter-mass which constitutes a support piece is mounted inside said housing by means of suspension devices 11 which bear on an internal shoulder of said housing, and by means of a suspension nut 12 ; said counterweight is kept centered in said housing by means of a centering ring 21;
- An insulating disc 16 is mounted between said housing and said cover and delimits therewith a cavity 15 in which are housed the electrical wires which provide the connection between said connector and said transducer elements.
- Said pavilion 1 which constitutes a second support part is generally provided with an elastic coating 17, which can be vulcanized on said pavilion, and which is tightened on one end of said housing by clamps 20, thus ensuring the tightness of said transducer electro-acoustic.
- said electro-acoustic transducer comprises a first stack of piezoelectric ceramics 6 in the form of discs alternating with electrodes 10, so as to constitute a first cylinder elongated along a longitudinal axis xx1, which in this mode of realization is confused with the axis of said electro-acoustic transducer.
- Said prestressing rod is anchored in said pavilion by screwing one of its threaded ends into a tapped hole machined in said pavilion.
- said electro-acoustic transducers comprises a second stack of piezoelectric ceramics 7 in the form of a crown alternating with electrodes 10, so as to constitute a second cylinder elongated along said axis xx1, and that said electro-acoustic transducer comprises a rigid intermediate piece 8, which is interposed between said first and second stacks of piezoelectric ceramics, said rigid intermediate piece 8 constituting said rigid intermediate assembly in this embodiment according to the invention.
- said stacks are supported by one of their longitudinal ends on one of said support pieces (horn) and by their other longitudinal end on the other support piece, (counter-mass).
- an electro-acoustic transducer according to the invention only a first end of a first of said transducer elements is pressed against a first support piece, only a first end of a second of said transducer elements is pressed against a second piece of support, and the transducer comprises a rigid intermediate assembly which is interposed between said first and second transducer elements, which comprises two parallel faces which bear respectively on the second ends of said transducer elements, and which is capable of being prestressed simultaneously with said first and second transducer elements, along said longitudinal axis (xx1) by said prestressing device.
- the bearing face 1A of said pavilion 1 is opposite the first bearing face A of said first stack of ceramics 6, the second bearing face B of said first stack is facing the first bearing face 81, located on the bottom of said rigid intermediate piece 8, the second bearing face 82 located on the outer flange of said rigid intermediate piece 8 is facing the first face d 'support C of said second ceramic stack 7, the second support face D of said second ceramic stack 7 is opposite the support face 2A located on said counter-mass.
- said prestressing rod is screwed and blocked on said pavilion, said first stack is made to slide around said rod which comes into contact with said pavilion, it is made to slide around said rod and around said first set of ceramics 6, said rigid intermediate piece which comes into contact with said first stack by its face 81, said second stack of ceramics 7 which comes into contact with said rod is made to slide around said rod and said rigid intermediate piece flange of said rigid intermediate part by its bearing face C, and finally sliding around said rod and said stack said counterweight which comes into contact by its face 2A with the face D of said second stack.
- Said counter-mass is then maintained and a pull is exerted on said rod, along its longitudinal axis and in a direction opposite to said roof; said traction therefore tends to bring said pavilion towards the counter-mass, and by means of said bearing faces opposite one another, said traction generates a compression preload along said axis xx1 of said first stack between said faces of support 1A, 81 respectively of said flag and of said intermediate rigid piece, said traction generates a compression preload along said axis xx1 of said second stack between said bearing faces 82, 2A respectively of said rigid intermediate piece and said counter-mass, said traction generates tensile preload along said axis xx1 of said intermediate piece rigid.
- the assembly thus formed can then be mounted in said housing, and the final mounting operations carried out.
- a clearance 9A, along said longitudinal axis xx1 must be provided between said counterweight 2 and said rigid intermediate piece 8.
- a clearance 9B must be provided between said intermediate piece 8 and said pavilion 1, so that during vibration movements of said pavilion and said rigid intermediate piece, under the action of the contraction and expansion movements of said first and second stacks, the contacts between said rigid intermediate piece, said flag and said counter-mass are avoided.
- the value of these clearances will preferably be of the order of a few millimeters.
- the rigidity in question is the longitudinal rigidity of said part or of said assembly, that is to say the rigidity with respect to tensile or compressive forces, along said longitudinal axis xx1; it is obvious that moreover the rigidity - we will then speak of stiffness - of said intermediate piece or of said intermediate assembly, along all other axes not parallel to xx1, must be sufficient in order to guarantee good mechanical strength; said longitudinal rigidity of said intermediate piece or of said intermediate assembly will in the majority of cases be significantly greater than the longitudinal rigidity of said first and second stacks.
- said rod 4, said first stack, said intermediate piece and said second stack are preferably sheathed by insulating sleeves 40, substantially cylindrical; these sleeves serve in fact to provide electrical insulation between these different parts; they also make it possible to minimize the friction which could occur between these parts, due to their relative vibratory movements.
- Passages are of course provided in these different parts which allow the routing of the electrical wires (not shown) from said cavity 15 to said electrodes of said stacks.
- said electro-acoustic transducer comprises clearances 22, 23 which correspond respectively to spaces formed between said housing and said roof on the one hand, and between said housing and said counter-mass of on the other hand, which spaces are generally filled with gas.
- FIG 2 there is shown a cross section of another embodiment of an electro-acoustic transducer according to the invention, in an assembly of the type "TONPILZ".
- said pavilion is in contact by a bearing face 1A with a first end A of said first stack of ceramics 6 in the form of discs, that said first stack is in contact by its second end B with the face 81 of said rigid intermediate assembly, said rigid intermediate assembly being supported by a face 82 on the first bearing face C of a second stack of ceramics 7, which may be in the form crown; nevertheless given the relatively large diameter of this crown, said ceramics 7 could advantageously be in the form of crown sectors, in order for example to obtain a section of the active parts - of ceramics - of said second stack substantially equal to the section of said first stack.
- said rigid intermediate assembly which transmits the prestressing forces in compression exerted by said rod 4 between said first and second stack, consists of the assembly of five rigid intermediate parts 8, and four intermediate stacks 8A, 8B, 8C, 8D, of piezoelectric ceramics, which can be in the form of crowns or sectors.
- said first and second stacks and said intermediate stacks are connected so that the vibrational movements of said stacks are in phase.
- said intermediate parts are cylindrical in shape, having for their axis said longitudinal axis xx1, and each provided at one end with an internal flange and at the other end with an external flange, which flanges are each provided with a bearing face, the two bearing faces of each of said rigid intermediate parts being parallel, and perpendicular to said longitudinal axis xx1.
- Games 9A are provided between each rigid intermediate piece which are liable to vibrate and said counter-mass, as well as clearances between each rigid intermediate piece and said pavilion.
- the prestressing exerted by said rod which tends to bring said pavilion closer to said counter-mass, generates a compression preload in said first and second stacks and said intermediate stacks 8A, 8B, 8C, 8D , and generates a tensile stress in said rigid intermediate parts.
- FIG 3 there is shown a cross-sectional view of an embodiment of an electro-acoustic transducer according to the invention, in an assembly of the "JANUS" type.
- the housing 3 generally cylindrical with longitudinal axis xx1, is not sealed; inside said housing are arranged symmetrically with respect to the transverse axis yy1, cutting said electro-acoustic transducer in its middle, two pavilions 1, connected by a preloading rod 4, provided at each end with a thread on which are screwed two locking nuts 5, which are supported on said pavilions; are also arranged inside said housing and symmetrically with respect to said axis yy1, two first stacks of ceramics 6, two rigid intermediate pieces 8, and two second stack of ceramics 7.
- the central counterweight 2 is generally of reduced size and mass compared to the assemblies of FIGS. 1 and 2, and said rod 4 tends to bring said pavilions closer to one another, likewise that it tends to bring the first two stacks of ceramics 6 together, the two rigid intermediate pieces from one another, and the second second stacks of ceramics 7 from each other.
- the rod 4 passes through the counter-mass, but is not rigidly linked to the latter.
- the counter-mass which may be in the form of a disc, has two parallel bearing faces 2A.
- each of the pavilions is supported by at least part of its face 1A on the first end of a first stack of piezoelectric ceramics 6, which may be in the form of disc, which first stack is supported by its second end on a first support face 81, located on the bottom of a rigid intermediate piece 8, which can be bell-shaped, which is provided at its second end with a second bearing face 82, which is parallel to said first bearing face 81, which rigid intermediate piece is supported by said face 82 on the first end of a second stack of piezoelectric ceramics 7, which s presses at its second end on a support face 2A of said central counterweight.
- JANUS This type of assembly called “JANUS” consists essentially of two “TONPILZ” assemblies as described in FIGS. 1 and 2, which would be placed symmetrically with respect to a transverse axis yy1, and which would have a common counter-mass.
- said stacks of piezoelectric ceramics are vibrated in phase located on the same side of said transverse axis yy1, and said stacks of piezoelectric ceramics are vibrated with a phase offset by 180 ° located on the other side of said transverse axis yy1.
- the elastic coating 17 which covers said pavilions 1, also surrounds said stacks of piezoelectric ceramics.
- the assembly consisting of said pavilions, said stacks and said counter-mass, coated with said elastic coating 17, is introduced into said housing and immobilized therein by parts 24 and 25 - generally in the form of tubes - and flanges.
- the cavity 15 allowing the feed wires of said ceramics to travel from them to the feed connector is located inside said counter-mass.
- this type of assembly comprises baffles 23, generally made of cellular material, which substantially fill the space between said elastic coating and the walls of said housing.
- FIG 4 there is shown a cross-sectional view on a reduced scale of an embodiment of an electro-acoustic transducer according to the invention, in an assembly of the "FLEXTENSIONAL" type.
- the housing of said electro-acoustic transducer is constituted by a shell 28, generally made of epoxy glass composite, which has the shape of a cylinder with an axis perpendicular to the plane of FIG. 4, of elliptical section, the small of which axis is carried by the transverse axis yy1 and the major axis is carried by the longitudinal axis xx1.
- Said support pieces are usually constituted in this assembly by a central core 27 and two inserts 26, which extend along an axis perpendicular to the plane of the figure; on either side of said transverse axis yy1, are usually, and in a known manner, arranged stacks of ceramics, of elongated shape, which are supported at one of their ends on one of said inserts, preferably by means of a slide 41 and a wedge 29, and at their other end on said core; the prestressing is carried out in this type of assembly by the shell itself, which, during assembly, is pinched along its transverse axis yy1, so that the assembly constituted by said slides and shims, said stacks and said core, then the pinch is released, which tends to release said cylindrical shell along said longitudinal axis xx1 and thus prestress said ceramic stacks.
- an elastic sealing coating 17 is provided, which surrounds said shell.
- FIG 5 there is shown a cross-sectional view of an embodiment of an electro-acoustic transducer according to the invention, in an assembly of the "TONPILZ" type equipped with magnetostrictive transducer elements.
- FIG. 6 a section along VI-VI of FIG. 5 is shown.
- said transducer elements consist of magnetostrictive bars 29, which are liable to vibrate along their longitudinal axis parallel to the axis xx1, under the effect of the magnetic field produced by the coils 30.
- the bars if killed on the same circle of axis xx1 are magnetically linked together by magnetic rings 31 which are not shown in FIG. 6.
- a first transducer element is constituted by four first bars located outside the rigid intermediate piece 8; which four first bars are supported by a first of their respective ends on the support face 1A of the pavilion 1 by means of a crown 31, and by their second end and by means of a crown 31 on the first bearing face of said rigid intermediate piece which is constituted in this embodiment by four legs 83.
- a second transducer element is constituted by four second bars located inside the rigid intermediate piece 8, which four second bars are supported by a first of their end and by means of a crown 31 respectively. on the bearing face 2A of the counterweight 2 and by their second end and / or by means of a second ring 31 on the second bearing face of said rigid intermediate piece 8, which is formed by the bottom 84, which is itself crossed by the prestressing rod 4.
- said rigid intermediate piece comprises in its central tubular part, a crown section which advantageously follows the outline of the coils 30 of said first four bars on its periphery, and whose internal profile follows the outline of the coils 30 of said four second bars.
- the technical field of the invention is that of immersed electro-acoustic transducers.
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Description
La présente invention est relative à un transducteur électro-acoustique immergé et à un procédé de fabrication de ce transducteur électro-acoustique.The present invention relates to a submerged electro-acoustic transducer and to a method of manufacturing this electro-acoustic transducer.
Les transducteurs électro-acoustiques sont couramment utilisés, notamment pour émettre des signaux destinés aux communications et à la détection sous-marine.Electro-acoustic transducers are commonly used, in particular to emit signals intended for communications and underwater detection.
Les transducteurs électro-acoustiques les plus couramment utilisés comprennent un moteur, ou partie active, qui est généralement constitué par un empilement de céramique piézo-électrique alternant avec des électrodes, l'ensemble formant un cylindre de forme allongée; sous l'action d'une tension appliquée aux céramiques, celles-ci se déforment; les céramiques sont arrangées et câblées de telle sorte que leurs déformations s'ajoutent, ce qui fait que l'on obtient des mouvements de contraction et de dilatation longitudinaux de l'empilement des céramiques piézo-électriques. Cet empilement est lié à une de ses deux extrémités longitudinales à une pièce d'appui généralement métallique, servant de support, souvent appelée contre-pièce d'appui ou contre-masse, qui est maintenue sensiblement immobile par rapport au boîtier du transducteur; l'empilement est lié à son autre extrémité à une autre masse, parfois appelée pavillon, qui vibre selon l'axe longitudinal de l'empilement, du fait des mouvements de celui-ci, résultant de la tension appliquée aux céramiques.The most commonly used electro-acoustic transducers include a motor, or active part, which generally consists of a stack of piezoelectric ceramic alternating with electrodes, the assembly forming a cylinder of elongated shape; under the action of a tension applied to ceramics, they deform; the ceramics are arranged and wired in such a way that their deformations are added, which means that longitudinal contraction and expansion movements of the stack of piezoelectric ceramics are obtained. This stack is linked at one of its two longitudinal ends to a generally metallic support piece, serving as a support, often called a counter-support piece or counter-mass, which is kept substantially stationary relative to the transducer housing; the stack is linked at its other end to another mass, sometimes called the pavilion, which vibrates along the longitudinal axis of the stack, due to the movements of the latter, resulting from the tension applied to the ceramics.
Ce pavillon est en contact avec le milieu de propagation souhaitée, généralement l'eau, en général par l'intermédiaire d'un revêtement élastique qui assure l'étanchéité du transmetteur.This flag is in contact with the desired propagation medium, generally water, in general by means of an elastic coating which seals the transmitter.
L'évolution des techniques et technologies dans ce domaine a conduit à la réalisation de plusieurs types de montages mécaniques relativement standards, pour ces transducteur électro-acoustiques, particulièrement les trois types suivants.The evolution of techniques and technologies in this field has led to the production of several types of relatively standard mechanical assemblies for these electro-acoustic transducers, particularly the following three types.
Les transducteurs électro-acoustiques de type "TONPILZ", comportent le montage mécanique de base, brièvement décrit ci-dessus, qui comprend une contre-masse fixée dans un boîtier cylindrique par l'intermédiaire de suspensions limitant les mouvements du boîtier étanche par rapport à cette contre-masse, un empilement de céramiques piézo-électriques qui met en mouvement de vibration un pavillon.The electro-acoustic transducers of the "TONPILZ" type include the basic mechanical assembly, briefly described above, which includes a counter-mass fixed in a cylindrical case by means of suspensions limiting the movements of the sealed case with respect to this counter-mass, a stack of ceramics piezoelectric which vibrates a pavilion.
L'empilement est précontraint axialement selon son axe longitudinal, par des moyens constitués en général par une tige vissée dans le pavillon, qui traverse l'empilement, qui est bloquée dans la contre-masse par un écrou et qui est mise en tension.The stack is axially prestressed along its longitudinal axis, by means generally constituted by a rod screwed into the roof, which passes through the stack, which is blocked in the counter-mass by a nut and which is tensioned.
Les transducteurs électro-acoustiques de type "JANUS" correspondent sensiblement à deux transducteurs électro-acoustiques de type "TONPILZ", ayant une contre-masse commune et dont les empilements vibrent en opposition de phase.The "JANUS" type electro-acoustic transducers correspond substantially to two "TONPILZ" type electro-acoustic transducers, having a common counter-mass and whose stacks vibrate in phase opposition.
Les transducteurs électro-acoustiques de type "FLEXTENSIONAL" utilisent un principe de précontrainte et de diffusion des vibrations dans le milieu de propagation quelque peu différent : dans ce type de transducteurs électro-acoustiques, par exemple les "FLEXTENSIONAL" de classe 4, le boîtier est constitué par une coque, généralement en composite verre époxy, de forme cylindrique à section elliptique; cette coque de section elliptique est, du fait de son élasticité, susceptible de s'aplatir et de s'arrondir; dans cette coque on dispose symétriquement par rapport à une âme centrale s'étendant selon l'axe de la coque cylindrique une ou plusieurs paires d'empilements de céramiques piézo-électriques, qui s'appuient à une extrémité sur des inserts métalliques qui s'étendent parallèlement à l'âme centrale, lesquels inserts métalliques s'appuient à l'intérieur de la coque, au voisinage de l'extrémité du grand axe de l'ellipse définissant la section de coque. EP-A-0 367 681 décrit un tel transducteur.Electro-acoustic transducers of the "FLEXTENSIONAL" type use a principle of prestressing and diffusion of vibrations in the somewhat different propagation medium: in this type of electro-acoustic transducers, for example the "FLEXTENSIONAL" of
L'ensemble constitué des empilements et de la contre-masse centrale est introduit dans la coque, celle-ci étant précontrainte par pincement, selon le petit axe de l'ellipse; lorsque l'ensemble est en place à l'intérieur de la coque, on relâche la précontrainte, le grand axe de l'ellipse raccourcit, ce qui précontraint l'ensemble, selon l'axe longitudinal des empilements.The assembly consisting of the stacks and the central counter-mass is introduced into the shell, the latter being prestressed by pinching, along the minor axis of the ellipse; when the assembly is in place inside the shell, the prestress is released, the long axis of the ellipse shortens, which prestresses the assembly, along the longitudinal axis of the stacks.
Bien que les éléments transducteurs le plus couramment utilisés soient constitués par des empilements de céramiques piézo-électriques, ces empilements de céramiques peuvent, dans certains cas, être remplacés par des transducteurs magnétostrictifs; ces transducteurs comprennent principalement un barreau allongé, construit dans un matériau généralement principalement constitué de terres rares, qui peut vibrer en se contractant et se dilatant selon son axe longitudinal , sous l'effet d'un champ magnétique créé par une bobine qui entoure ce barreau.Although the most commonly used transducer elements consist of stacks of piezoelectric ceramics, these stacks of ceramics can, in certain cases, be replaced by magnetostrictive transducers; these transducers mainly comprise an elongated bar, constructed of a material generally mainly consisting of rare earths, which can vibrate by contracting and expanding along its axis longitudinal, under the effect of a magnetic field created by a coil which surrounds this bar.
Les utilisations actuelles de ces transducteurs électro-acoustiques font que l'on recherche des moyens d'augmenter la puissance de ces transducteurs électro-acoustiques et d'émettre à des fréquences de plus en plus basses.Current uses of these electro-acoustic transducers mean that we are looking for ways to increase the power of these electro-acoustic transducers and to transmit at increasingly low frequencies.
Dans le cas des transducteurs électro-acoustiques construits avec des empilements de céramiques piézo-électriques, on sait que la puissance est sensiblement proportionnelle au volume de céramique mise dans le transducteur électro-acoustique, la limite inférieure des fréquences susceptibles d'être émises étant liée à la fréquence propre en compression longitudinale de l'empilement des céramiques; on est donc conduit, pour réaliser un transducteur électro-acoustique de grande puissance, capable d'émettre les fréquences les plus basses possibles, à réaliser un empilement formant un cylindre de grande hauteur.In the case of electro-acoustic transducers constructed with stacks of piezoelectric ceramics, it is known that the power is substantially proportional to the volume of ceramic placed in the electro-acoustic transducer, the lower limit of the frequencies likely to be emitted being linked at the natural frequency in longitudinal compression of the stack of ceramics; in order to produce a high power electro-acoustic transducer capable of emitting the lowest possible frequencies, we are therefore led to produce a stack forming a cylinder of great height.
Ce principe se heurte évidemment à des limites technologiques et surtout économiques; on est alors souvent conduit à réaliser une pluralité de transducteurs électro-acoustiques qui sont assemblés en antenne, aussi appelée réseau, ce qui complique le montage mécanique de l'ensemble, le câblage électrique et augmente le coût.This principle obviously comes up against technological and above all economic limits; it is then often necessary to produce a plurality of electro-acoustic transducers which are assembled as an antenna, also called an array, which complicates the mechanical assembly of the assembly, the electrical wiring and increases the cost.
Le problème posé est donc de procurer des transducteurs électro-acoustiques susceptibles d'être immergés, et leur procédé de fabrication, permettant, sans augmentation sensible de l'encombrement du transducteur électro-acoustique, de fournir une puissance accrue et/ou susceptibles d'émettre à des fréquences relativement basses.The problem posed is therefore to provide electro-acoustic transducers capable of being submerged, and their manufacturing process, allowing, without appreciable increase in the size of the electro-acoustic transducer, to provide increased power and / or capable of transmit at relatively low frequencies.
Selon l'invention, une solution au problème posé est de procurer un transducteur électro-acoustique comportant dans un boîtier, au moins une première pièce d'appui, ou pavillon, et au moins une deuxième pièce d'appui, ou contre-masse, comportant au moins deux éléments transducteurs de forme allongée selon un axe longitudinal dudit transducteur, comportant au moins une tige de précontrainte selon ledit axe longitudinal, entre lesdites premières et deuxièmes pièces d'appui desdits éléments transducteurs, tel que lesdits éléments transducteurs sont disposés côte à côte, et/ou constituent des cylindre coaxiaux ayant pour axe ledit axe longitudinal, et peuvent vibrer en phase, et tel qu'il comporte au moins une pièce ou ensemble, intermédiaire rigide, mobile, qui est montée ou empilée, intercalée entre lesdits éléments transducteurs, mécaniquement en série avec lesdits éléments transducteurs, de sorte que ladite pièce intermédiaire rigide peut être précontrainte grâce à ladite tige, simultanément avec lesdits éléments transducteurs, et de sorte que ladite pièce intermédiaire rigide est susceptible de vibrer en phase avec lesdits éléments transducteurs.According to the invention, a solution to the problem posed is to provide an electro-acoustic transducer comprising in a housing, at least a first support part, or pavilion, and at least a second support part, or counter-mass, comprising at least two transducer elements of elongated shape along a longitudinal axis of said transducer, comprising at least one prestressing rod along said longitudinal axis, between said first and second bearing parts of said transducer elements, such that said transducer elements are arranged side by side side, and / or constitute coaxial cylinders having for axis said longitudinal axis, and can vibrate in phase, and such that it comprises at least one part or assembly, rigid, mobile intermediate, which is mounted or stacked, interposed between said transducer elements, mechanically in series with said transducer elements, so that said rigid intermediate piece can be prestressed by said rod, simultaneously with said transducer elements, and so that said rigid intermediate piece is capable of vibrating in phase with said transducer elements.
Avantageusement, un transducteur électro-acoustique selon l'invention comporte au moins deux éléments transducteurs de forme allongée selon un axe longitudinal, situés entre une première et une deuxième pièces d'appui, précontraints selon ledit axe longitudinal par un dispositif de précontrainte, qui tend à rapprocher lesdites pièces d'appui, lesquels éléments transducteurs comportent chacun deux extrémités longitudinales, parallèles, planes, lesquels éléments transducteurs sont parallèles, disposés côte à côte, et fonctionnent en phase, l'ensemble étant contenu dans un boîtier, et seule une première extrémité d'un premier desdits éléments transducteur est appuyée contre ladite première pièce d'appui, et seule une première extrémité d'un deuxième desdits éléments transducteurs est appuyée contre ladite deuxième pièce d'appui, et ledit transducteur comporte un ensemble intermédiaire rigide qui est intercalé entre lesdits premier et deuxième éléments transducteurs, qui comporte deux faces parallèles qui s'appuient respectivement sur les deuxièmes extrémités desdits éléments transducteurs et qui est susceptible d'être précontraint simultanément avec lesdits premier et deuxième éléments transducteurs, selon ledit axe longitudinal par ledit dispositif de précontrainte ; chacun desdits éléments transducteurs peut être constitué soit par au moins un barreau magnétostrictif, soit par au moins un empilement de céramiques piézo-électriques, alternant avec des électrodes formant un cylindre de forme allongée.Advantageously, an electro-acoustic transducer according to the invention comprises at least two transducer elements of elongated shape along a longitudinal axis, located between a first and a second support piece, prestressed along said longitudinal axis by a prestressing device, which tends to bring said support pieces closer together, which transducer elements each have two longitudinal, parallel, planar ends, which transducer elements are parallel, arranged side by side, and operate in phase, the assembly being contained in a housing, and only a first end of a first of said transducer elements is pressed against said first support piece, and only a first end of a second of said transducer elements is pressed against said second support piece, and said transducer comprises a rigid intermediate assembly which is sandwiched between said first and second transducer elements, which has two parallel faces which bear respectively on the second ends of said transducer elements and which is capable of being prestressed simultaneously with said first and second transducer elements, along said longitudinal axis by said prestressing device; each of said transducer elements can be constituted either by at least one magnetostrictive bar, or by at least one stack of piezoelectric ceramics, alternating with electrodes forming a cylinder of elongated shape.
Dans un transducteur électro-acoustique selon l'invention, des jeux longitudinaux sont respectivement prévus entre ledit ensemble intermédiaire rigide et lesdites première et deuxième pièces d'appui, de sorte que lors des déplacements relatifs entre lesdites pièces d'appui dus aux forces développées par lesdits éléments transducteurs et aux forces dues audit dispositif de précontrainte, les contacts entre ledit ensemble intermédiaire rigide et lesdites pièces d'appui, sont évités.In an electro-acoustic transducer according to the invention, longitudinal clearances are respectively provided between said rigid intermediate assembly and said first and second support pieces, so that during relative displacements between said support pieces due to the forces developed by said transducer elements and to the forces due to said prestressing device, the contacts between said rigid intermediate assembly and said support parts, are avoided.
Avantageusement, dans un transducteur électro-acoustique selon l'invention, ledit ensemble intermédiaire rigide est constitué par une seule pièce métallique rigide, qui peut être par exemple constituée d'une partie sensiblement cylindrique, ayant un axe, parallèle audit axe longitudinal, terminée à une extrémité par un fond qui comporte une desdites deux faces parallèles, qui s'appuie sur la deuxième extrémité d'un premier desdits éléments transducteurs, et à son autre extrémité, par une collerette externe qui comporte l'autre desdites deux faces parallèles, qui s'appuie sur la deuxième extrémité du deuxième desdits éléments transducteurs.Advantageously, in an electro-acoustic transducer according to the invention, said rigid intermediate assembly consists of a single rigid metal part, which can for example consist of a substantially cylindrical part, having an axis, parallel to said longitudinal axis, terminated at one end by a bottom which comprises one of said two parallel faces, which is supported on the second end of a first of said transducer elements, and at its other end, by an external flange which comprises the other of said two parallel faces, which rests on the second end of the second of said transducer elements.
Dans un mode de réalisation préférentiel, ledit ensemble intermédiaire comporte au moins deux pièces intermédiaires rigides et au moins un élément transducteur intermédiaire qui est intercalé entre lesdites deux pièces intermédiaires rigides et disposé mécaniquement en série avec celles-ci.In a preferred embodiment, said intermediate assembly comprises at least two rigid intermediate parts and at least one intermediate transducer element which is interposed between said two rigid intermediate parts and arranged mechanically in series therewith.
Dans des modes préférentiels de réalisation de transducteurs électro-acoustiques selon l'invention, ledit dispositif de précontrainte comporte une ou plusieurs tiges, qui sont fixées respectivement par chacune de leurs deux extrémités à chacune desdites pièces d'appui, ou à une pièce intermédiaire, notamment pour l'application aux montages de type "TONPILZ" et "JANUS", ou bien est constitué par ledit boîtier qui est déformable, notamment pour l'application aux montages de type "FLEXTENSIONAL".In preferred embodiments of electro-acoustic transducers according to the invention, said prestressing device comprises one or more rods, which are fixed respectively by each of their two ends to each of said support pieces, or to an intermediate piece, in particular for application to "TONPILZ" and "JANUS" type assemblies, or else is constituted by said case which is deformable, in particular for application to "FLEXTENSIONAL" type assemblies.
Dans un mode particulier de réalisation selon l'invention, les sections transversales des parties actives desdits premier et deuxième éléments transducteurs sont sensiblement égales.In a particular embodiment according to the invention, the cross sections of the active parts of said first and second transducer elements are substantially equal.
Une solution au problème posé est également de procurer un procédé de fabrication de transducteurs électro-acoustiques du type comportant au moins un élément transducteur de forme allongée, précontraint axialement entre deux pièces d'appui, caractérisé en ce que l'on monte entre lesdites pièces d'appui, un premier élément transducteur de forme allongée, n'ayant qu'une première extrémité appuyée contre une des deux pièces d'appui et un deuxième élément transducteur de forme allongée, n'ayant qu'une première extrémité appuyée contre l'autre pièce d'appui, lesquels éléments transducteurs sont parallèles et disposés côte à côte et fonctionnent en phase, on intercale entre ces deux éléments transducteurs une pièce intermédiaire qui prend appui sur les deuxièmes extrémités desdits éléments transducteurs, et on précontraint axialement entre les deux pièces d'appui les deux éléments transducteurs et ladite pièce intermédiaire qui transmet les efforts longitudinaux entre les deux éléments transducteurs.A solution to the problem posed is also to provide a method of manufacturing electro-acoustic transducers of the type comprising at least one transducer element of elongated shape, prestressed axially between two support pieces, characterized in that it is mounted between said pieces support, a first transducer element of elongated shape, having only one first end pressed against one of the two support pieces and a second transducer element of elongated shape, having only one first end pressed against the other support piece, which transducer elements are parallel and arranged side by side and operate in phase, interposed between these two transducer elements an intermediate piece which bears on the second ends of said transducer elements, and the two transducer elements and said intermediate piece which transmits the longitudinal forces between the two transducer elements are axially prestressed between the two bearing pieces.
Les avantages apportés par les transducteurs électro-acoustiques selon l'invention sont nombreux.The advantages provided by the electro-acoustic transducers according to the invention are numerous.
En effet on peut par exemple, dans un transducteur électro-acoustiques selon l'invention, imbriquer un deuxième empilement de céramiques en forme de couronne, qui entoure sensiblement le premier empilement, les deux empilements ayant la même hauteur et les éléments actifs ayant sensiblement la même section, et on obtient ainsi un transducteur électro-acoustique dont la puissance sera sensiblement doublée par rapport aux transducteurs électro-acoustiques connus du même encombrement, quine comprennent que ledit premier empilement, puisque le volume de céramiques est doublé; en même temps, la longueur équivalente de l'empilement fictif ainsi réalisé par les deux empilements imbriqués est doublée ; par conséquent, la fréquence de résonance de l'empilement imbriqué selon l'invention, étant de façon approchée, inversement proportionnelle à la racine carrée de la longueur, sera donc diminuée de 40% par rapport au transducteur électro-acoustique connu de même encombrement.In fact, it is possible, for example, in an electro-acoustic transducer according to the invention, to nest a second stack of ceramics in the form of a crown, which substantially surrounds the first stack, the two stacks having the same height and the active elements having substantially the same section, and an electro-acoustic transducer is thus obtained, the power of which will be substantially doubled compared to known electro-acoustic transducers of the same size, which include that said first stack, since the volume of ceramics is doubled; at the same time, the equivalent length of the fictitious stack thus produced by the two nested stacks is doubled; therefore, the resonant frequency of the nested stack according to the invention, being approximately, inversely proportional to the square root of the length, will therefore be reduced by 40% compared to the known electro-acoustic transducer of the same size.
Par ailleurs, le montage selon l'invention peut être utilisé de façon à imbriquer plus de deux empilements, sans augmenter sensiblement l'encombrement du transducteur, ce qui permet d'arriver à des performances encore supérieures en puissance et/ou fréquence basse.Furthermore, the assembly according to the invention can be used so as to nest more than two stacks, without significantly increasing the size of the transducer, which makes it possible to achieve even higher performance in low power and / or frequency.
La fiabilité des ensembles composés de transducteurs électro-acoustiques selon l'invention est nettement améliorée, et le colt de ces ensembles est nettement diminué.The reliability of the assemblies composed of electro-acoustic transducers according to the invention is significantly improved, and the cost of these assemblies is markedly reduced.
Les transducteurs électro-acoustiques selon l'invention peuvent être construits aussi bien avec des transducteurs en céramiques piézo-électriques qu'avec des barreaux magnétostrictifs.The electro-acoustic transducers according to the invention can be constructed both with piezoelectric ceramic transducers and with magnetostrictive bars.
Les nombreux avantages et les caractéristiques de l'invention apparaîtront clairement dans les figures annexés qui représentent, sans aucun caractère limitatif, des modes de réalisation de transducteurs électro-acoustiques selon l'invention et leur procédé de fabrication.The numerous advantages and characteristics of the invention will appear clearly in the appended figures which represent, without any limiting character, embodiments of electro-acoustic transducers according to the invention and their manufacturing process.
La figure 1 représente une vue en coupe transversale, à échelle réduite, d'un mode de réalisation de transducteur électro-acoustique selon l'invention, dans un montage de type "TONPILZ".FIG. 1 represents a cross-sectional view, on a reduced scale, of an embodiment of electro-acoustic transducer according to the invention, in an assembly of the "TONPILZ" type.
La figure 2 représente une vue en coupe transversale, à échelle réduite, d'un autre mode de réalisation.FIG. 2 represents a cross-sectional view, on a reduced scale, of another embodiment.
La figure 3 représente une vue en coupe transversale, à échelle réduite, d'un mode de réalisation de transducteur électro-acoustique selon l'invention, dans un montage de type "JANUS".FIG. 3 represents a cross-sectional view, on a reduced scale, of an embodiment of electro-acoustic transducer according to the invention, in an assembly of the "JANUS" type.
La figure 4 représente une vue en coupe transversale, à échelle réduite, d'un mode de réalisation de transducteur électro-acoustique selon l'invention, dans un montage de type "FLEXTENSIONAL".FIG. 4 represents a cross-sectional view, on a reduced scale, of an embodiment of electro-acoustic transducer according to the invention, in an assembly of the "FLEXTENSIONAL" type.
La figure 5 représente une vue en coupe transversale, à échelle réduite, d'un mode de réalisation de transducteur électro-acoustique selon l'invention, dans un montage de type "TONPILZ" équipé d'éléments transducteurs magnétostrictifs.FIG. 5 represents a cross-sectional view, on a reduced scale, of an embodiment of electro-acoustic transducer according to the invention, in a “TONPILZ” type assembly fitted with magnetostrictive transducer elements.
La figure 6 est une coupe selon VI-VI de la figure 5.FIG. 6 is a section on VI-VI of FIG. 5.
Selon la figure 1, on a représenté un transducteur électro-acoustique selon l'invention qui est équipé de de deux éléments transducteurs constitués de céramiques piézo-électriques, dans un montage de type "TONPILZ".According to Figure 1, there is shown an electro-acoustic transducer according to the invention which is equipped with two transducer elements made of piezoelectric ceramics, in an assembly of the "TONPILZ" type.
De façon connue, le transducteur électro-acoustique comporte dans ce type de montage, un boîtier métallique 3, une contre-masse 2, un pavillon 1, une tige de précontrainte 4 et un écrou 5 de blocage.In a known manner, the electro-acoustic transducer comprises in this type of mounting, a
On voit que ledit boîtier 3 est fermé à une extrémité par un couvercle 13, de façon étanche grâce à un joint 14.It can be seen that said
Ladite contre-masse qui constitue une pièce d'appui est montée à l'intérieur dudit boîtier par l'intermédiaire de dispositifs de suspension 11 qui prennent appui sur un épaulement interne dudit boîtier, et par l'intermédiaire d'un écrou de suspension 12; ladite contre-masse est maintenue centrée dans ledit boîtier grâce à une bague de centrage 21;Said counter-mass which constitutes a support piece is mounted inside said housing by means of
Sur ledit couvercle 13 est monté un connecteur étanche 18 lié à un câble électrique 19 qui amène l'énergie électrique nécessaire à l'alimentation desdites céramiques piézo-électriques.On said
Un disque isolant 16 est monté entre ledit boîtier et ledit couvercle et délimite avec celui-ci une cavité 15 où sont logés les fils électriques qui assurent la connexion entre ledit connecteur et lesdits éléments transducteurs.An insulating
Ledit pavillon 1 qui constitue une deuxième pièce d'appui est généralement pourvu d'un revêtement élastique 17, qui peut être vulcanisé sur ledit pavillon, et qui est serré sur une extrémité dudit boîtier par des colliers 20, assurant ainsi l'étanchéité dudit transducteur électro-acoustique.Said
On voit que de façon connue, ledit transducteur électro-acoustique comporte un premier empilement de céramiques piézo-électriques 6 en forme de disques alternant avec des électrodes 10, de façon à constituer un premier cylindre allongé selon un axe longitudinal xx1, qui dans ce mode de réalisation est confondu avec l'axe dudit transducteur électro-acoustique.We see that in known manner, said electro-acoustic transducer comprises a first stack of
Ladite tige de précontrainte est ancrée dans ledit pavillon par vissage d'une de ses extrémités filetées dans un trou taraudé usiné dans ledit pavillon.Said prestressing rod is anchored in said pavilion by screwing one of its threaded ends into a tapped hole machined in said pavilion.
On voit que conformément à l'invention, ledit transducteurs électro-acoustique comporte un deuxième empilement de céramiques piézo-électriques 7 en forme de couronne alternant avec des électrodes 10, de façon à constituer un deuxième cylindre allongé selon ledit axe xx1, et que ledit transducteur électro-acoustique comporte une pièce intermédiaire rigide 8, qui est intercalée entre lesdits premier et deuxième empilements de céramiques piézo-électriques, ladite pièce intermédiaire rigide 8 constituant ledit ensemble intermédiaire rigide dans ce mode de réalisation selon l'invention.It can be seen that, in accordance with the invention, said electro-acoustic transducers comprises a second stack of
Dans les transducteurs électro-acoustiques connus, lesdits empilements prennent appui par une de leurs extrémités longitudinales sur une desdites pièces d'appui (pavillon) et par leur autre extrémité longitudinale sur l'autre pièce d'appui, (contre-masse). Dans un transducteur électro-acoustique selon l'invention, seule une première extrémité d'un premier desdits éléments transducteurs est appuyée contre une première pièce d'appui, seule une première extrémité d'un deuxième desdits éléments transducteurs est appuyé contre une deuxième pièce d'appui, et le transducteur comporte un ensemble intermédiaire rigide qui est intercalé entre lesdits premier et deuxième éléments transducteurs, qui comporte deux faces parallèles qui s'appuient respectivement sur les deuxièmes extrémités desdits éléments transducteurs, et qui est susceptible d'être précontraint simultanément avec lesdits premier et deuxième éléments transducteurs, selon ledit axe longitudinal (xx1) par ledit dispositif de précontrainte.In known electro-acoustic transducers, said stacks are supported by one of their longitudinal ends on one of said support pieces (horn) and by their other longitudinal end on the other support piece, (counter-mass). In an electro-acoustic transducer according to the invention, only a first end of a first of said transducer elements is pressed against a first support piece, only a first end of a second of said transducer elements is pressed against a second piece of support, and the transducer comprises a rigid intermediate assembly which is interposed between said first and second transducer elements, which comprises two parallel faces which bear respectively on the second ends of said transducer elements, and which is capable of being prestressed simultaneously with said first and second transducer elements, along said longitudinal axis (xx1) by said prestressing device.
Plus précisément, dans ce mode particulier de réalisation selon l'invention, la face d'appui 1A dudit pavillon 1 est en regard de la première face d'appui A dudit premier empilement de céramiques 6, la deuxième face d'appui B dudit premier empilement est en regard de la première face d'appui 81, située sur le fond de ladite pièce intermédiaire rigide 8, la deuxième face d'appui 82 située sur la collerette externe de ladite pièce intermédiaire rigide 8 est en regard de la première face d'appui C dudit deuxième empilement de céramiques 7, la deuxième face d'appui D dudit deuxième empilement de céramique 7 est en regard de la face d'appui 2A située sur ladite contre-masse.More specifically, in this particular embodiment according to the invention, the
Lors du montage dudit transducteur électro-acoustique selon l'invention, on visse et on bloque ladite tige de précontrainte sur ledit pavillon, on fait coulisser autour de ladite tige ledit premier empilement qui vient au contact dudit pavillon, on fait coulisser autour de ladite tige et autour dudit premier ensemble de céramiques 6, ladite pièce intermédiaire rigide qui vient au contact dudit premier empilement par sa face 81, on fait coulisser autour de ladite tige et de ladite pièce rigide intermédiaire ledit deuxième empilement de céramiques 7 qui vient au contact de ladite collerette de ladite pièce intermédiaire rigide par sa face d'appui C, et on fait enfin coulisser autour de ladite tige et dudit empilement ladite contre-masse qui vient au contact par sa face 2A avec la face D dudit deuxième empilement.When mounting said electro-acoustic transducer according to the invention, said prestressing rod is screwed and blocked on said pavilion, said first stack is made to slide around said rod which comes into contact with said pavilion, it is made to slide around said rod and around said first set of
On maintient ensuite ladite contre-masse et on exerce une traction sur ladite tige, selon son axe longitudinal et dans une direction opposée audit pavillon; ladite traction tend donc à rapprocher ledit pavillon vers la contre-masse, et par l'intermédiaire desdites faces d'appui en regard les unes des autres, ladite traction engendre une précontrainte de compression selon ledit axe xx1 dudit premier empilement entre lesdites faces d'appui 1A, 81 respectives dudit pavillon et de ladite pièce rigide intermédiaire, ladite traction engendre une précontrainte de compression selon ledit axe xx1 dudit deuxième empilement entre lesdites faces d'appui 82, 2A respectivement de ladite pièce intermédiaire rigide et de ladite contre-masse, ladite traction engendre une précontrainte de traction selon ledit axe xx1 de ladite pièce intermédiaire rigide.Said counter-mass is then maintained and a pull is exerted on said rod, along its longitudinal axis and in a direction opposite to said roof; said traction therefore tends to bring said pavilion towards the counter-mass, and by means of said bearing faces opposite one another, said traction generates a compression preload along said axis xx1 of said first stack between said faces of
De façon connue, on visse ensuite, sans faire cesser ladite traction, ledit écrou 5 sur la deuxième extrémité filetée de ladite tige jusqu'à ce qu'il vienne au contact de ladite contre-masse puis on relâche ladite traction, l'écrou maintenant l'ensemble en précontrainte.In known manner, then screwing, without stopping said pulling, said
L'ensemble ainsi constitué peut alors être monté dans ledit boîtier, et les opérations finales de montage réalisées.The assembly thus formed can then be mounted in said housing, and the final mounting operations carried out.
Il est clair qu'un parallélisme de très bonne qualité doit être obtenu entre les faces d'appui de ces pièces, particulièrement entre lesdites faces d'appui 81 et 82 de ladite pièce intermédiaire rigide.It is clear that a very good quality of parallelism must be obtained between the bearing faces of these parts, particularly between said bearing
On voit que dans un transducteur électro-acoustique selon l'invention un jeu 9A, selon ledit axe longitudinal xx1 doit être prévu entre ladite contre-masse 2 et ladite pièce intermédiaire rigide 8. D'autre part un jeu 9B doit être prévu entre ladite pièce intermédiaire 8 et ledit pavillon 1, afin que lors des déplacements en vibration dudit pavillon et de ladite pièce rigide intermédiaire, sous l'action des mouvements de contraction et de dilatation desdits premier et deuxième empilements, les contacts entre ladite pièce intermédiaire rigide, ledit pavillon et ladite contre-masse soient évités. La valeur de ces jeux sera préférentiellement de l'ordre de quelques millimètres.It can be seen that in an electro-acoustic transducer according to the invention a
Dans ce document, dans les expressions - ensemble intermédiaire rigide - et - pièce intermédiaire rigide -, la rigidité dont il est question est la rigidité longitudinale de ladite pièce ou dudit ensemble, c'est-à-dire la rigidité vis à vis d'efforts de traction ou de compression, selon ledit axe longitudinal xx1; il est évident que par ailleurs la rigidité -on parlera alors de raideur - de ladite pièce intermédiaire ou dudit ensemble intermédiaire, selon tous autres axes non parallèles à xx1, doit être suffisante afin de garantir une bonne tenue mécanique; ladite rigidité longitudinale de ladite pièce intermédiaire ou dudit ensemble intermédiaire sera dans la majorité des cas nettement supérieure à la rigidité longitudinale desdits premier et deuxième empilements.In this document, in the expressions - rigid intermediate assembly - and - rigid intermediate part -, the rigidity in question is the longitudinal rigidity of said part or of said assembly, that is to say the rigidity with respect to tensile or compressive forces, along said longitudinal axis xx1; it is obvious that moreover the rigidity - we will then speak of stiffness - of said intermediate piece or of said intermediate assembly, along all other axes not parallel to xx1, must be sufficient in order to guarantee good mechanical strength; said longitudinal rigidity of said intermediate piece or of said intermediate assembly will in the majority of cases be significantly greater than the longitudinal rigidity of said first and second stacks.
Il est à noter que ladite tige 4, ledit premier empilement, ladite pièce intermédiaire et ledit deuxième empilement sont préférentiellement gainés par des fourreaux isolant 40, sensiblement cylindriques; ces fourreaux servent en effet à assurer l'isolation électrique entre ces différentes pièces; ils permettent en outre, de minimiser les frottements qui pourraient intervenir entre ces pièces, du fait de leurs mouvements vibratoires relatifs.It should be noted that said
Des passages (non représentés) sont bien sûr prévus dans ces différentes pièces qui permettent l'acheminement des fils électriques (non représentés) de ladite cavité 15 jusqu'auxdites électrodes desdits empilements.Passages (not shown) are of course provided in these different parts which allow the routing of the electrical wires (not shown) from said
Il est clair que le câblage électrique desdits premier et deuxième empilement est tel que les vibrations longitudinales respectives desdits empilements s'additionnent à chaque instant, ce qui fait que les amplitudes s'ajoutent, et donc que la puissance desdits transducteurs électro-acoustiques est sensiblement égale à la somme des puissances desdits premier et deuxième empilements.It is clear that the electrical wiring of said first and second stack is such that the respective longitudinal vibrations of said stacks add up at each instant, which means that the amplitudes are added, and therefore that the power of said electro-acoustic transducers is substantially equal to the sum of the powers of said first and second stacks.
On voit sur la figure que de façon connue, ledit transducteur électro-acoustique comporte des jeux 22, 23 qui correspondent respectivement à des espaces ménagés entre ledit boîtier et ledit pavillon d'une part, et entre ledit boîtier et ladite contre-masse d'autre part, lesquels espaces sont généralement remplis de gaz.It can be seen in the figure that, in a known manner, said electro-acoustic transducer comprises
Sur la figure 2, on a représenté une coupe transversale d'un autre mode de réalisation d'un transducteur électro-acoustique selon l'invention, dans un montage de type "TONPILZ".In Figure 2, there is shown a cross section of another embodiment of an electro-acoustic transducer according to the invention, in an assembly of the type "TONPILZ".
Les éléments fonctionnels identiques à ceux de la figure 1 sont repérés par les mêmes numéros.The functional elements identical to those of FIG. 1 are identified by the same numbers.
On voit sur la figure, que dans ce mode particulier de réalisation selon l'invention, ledit pavillon est en contact par une face d'appui 1A avec une première extrémité A dudit premier empilement de céramiques 6 en forme de disques, que ledit premier empilement est en contact par sa deuxième extrémité B avec la face 81 dudit ensemble intermédiaire rigide, ledit ensemble intermédiaire rigide étant en appui par une face 82 sur la première face d'appui C d'un deuxième empilement de céramiques 7, qui peuvent être en forme de couronne; néanmoins compte tenu du diamètre relativement important de cette couronne, lesdites céramiques 7 pourraient avantageusement être en forme de secteurs de couronne, afin par exemple d'obtenir une section des parties actives - des céramiques - dudit deuxième empilement sensiblement égale à la section dudit premier empilement. Ces choix de formes et de dimensions sont faits en fonction des performances demandées au transducteur.It can be seen in the figure, that in this particular embodiment according to the invention, said pavilion is in contact by a
On remarque sur cette figure, que conformément à l'invention, ledit ensemble intermédiaire rigide qui transmet les efforts de précontrainte en compression exercés par ladite tige 4 entre lesdits premier et deuxième empilement, est constitué par l'assemblage de cinq pièces intermédiaires rigides 8, et de quatre empilements intermédiaires 8A, 8B, 8C, 8D, de céramiques piézo-électriques, qui peuvent être en forme de couronnes ou de secteurs.It can be seen in this figure, that in accordance with the invention, said rigid intermediate assembly which transmits the prestressing forces in compression exerted by said
Selon l'invention, lesdits premier et deuxième empilements et lesdits empilements intermédiaires sont connectés de sorte que les mouvements vibratoires desdits empilements soient en phase.According to the invention, said first and second stacks and said intermediate stacks are connected so that the vibrational movements of said stacks are in phase.
On voit que lesdites pièces intermédiaires sont de forme cylindrique, ayant pour axe ledit axe longitudinal xx1, et munies chacune à une extrémité d'une collerette interne et à l'autre extrémité d'une collerette externe, lesquelles collerettes sont chacune munies d'une face d'appui, les deux faces d'appui de chacune desdites pièces intermédiaires rigides étant parallèles, et perpendiculaires audit axe longitudinal xx1.It can be seen that said intermediate parts are cylindrical in shape, having for their axis said longitudinal axis xx1, and each provided at one end with an internal flange and at the other end with an external flange, which flanges are each provided with a bearing face, the two bearing faces of each of said rigid intermediate parts being parallel, and perpendicular to said longitudinal axis xx1.
Des jeux 9A sont prévus entre chaque pièce rigide intermédiaire qui sont susceptibles de vibrer et ladite contre-masse, ainsi que des jeux entre chaque pièce intermédiaire rigide et ledit pavillon.
On voit que, conformément à l'invention, la précontrainte exercée par ladite tige qui tend à rapprocher ledit pavillon de ladite contre-masse, engendre une précontrainte de compression dans lesdits premier et deuxième empilements et lesdits empilements intermédiaires 8A, 8B, 8C, 8D, et engendre une contrainte de traction dans lesdites pièces intermédiaires rigides.It can be seen that, in accordance with the invention, the prestressing exerted by said rod which tends to bring said pavilion closer to said counter-mass, generates a compression preload in said first and second stacks and said
Sur la figure 3, on a représenté une vue en coupe transversale d'un mode de réalisation d'un transducteur électro-acoustique selon l'invention, dans un montage de type "JANUS".In Figure 3, there is shown a cross-sectional view of an embodiment of an electro-acoustic transducer according to the invention, in an assembly of the "JANUS" type.
On voit sur cette figure, que de façon connue dans ce type de montage de transducteur électro-acoustique, le boîtier 3 généralement cylindrique d'axe longitudinal xx1, n'est pas fermé de façon étanche; à l'intérieur dudit boîtier sont disposés symétriquement par rapport à l'axe transversal yy1, coupant ledit transducteur électro-acoustique en son milieu, deux pavillons 1, reliés par une tige 4 de précontrainte, munie à chaque extrémité d'un filetage sur lequel sont vissés deux écrous 5 de blocage, qui sont en appui sur lesdits pavillons; sont également disposés à l'intérieur dudit boîtier et symétriquement par rapport audit axe yy1, deux premiers empilements de céramiques 6, deux pièces rigides intermédiaires 8, et deux second empilement de céramiques 7.We see in this figure, that in a known manner in this type of electro-acoustic transducer mounting, the
Dans ce type de montage, la contre-masse 2 centrale, est généralement de taille et de masse réduite par rapport aux montages des figures 1 et 2, et ladite tige 4 tend à rapprocher lesdits pavillons l'un de l'autre, de même qu'elle tend à rapprocher les deux premiers empilements de céramiques 6 l'un de l'autre, les deux pièces intermédiaires rigides l'une de l'autre, et les deux deuxièmes empilements de céramiques 7 l'un de l'autre.In this type of assembly, the
On note que dans ce mode de réalisation, la tige 4 traverse la contre-masse, mais n'est pas liée rigidement à celle-ci.Note that in this embodiment, the
La contre-masse, qui peut être en forme de disque, comporte deux faces d'appui parallèles 2A.The counter-mass, which may be in the form of a disc, has two parallel bearing faces 2A.
On voit sur la figure que, conformément à l'invention, chacun des pavillons s'appuie par une partie au moins de sa face 1A sur la première extrémité d'un premier empilement de céramiques piézo-électriques 6, qui peuvent être en forme de disque, lequel premier empilement s'appuie par sa deuxième extrémité sur une première face d'appui 81, située sur le fond d'une pièce intermédiaire rigide 8, qui peut être en forme de cloche, qui est munie à sa deuxième extrémité d'une deuxième face d'appui 82, qui est parallèle à ladite première face d'appui 81, laquelle pièce intermédiaire rigide s'appuie par ladite face 82 sur la première extrémité d'un deuxième empilement de céramiques piézo-électriques 7, qui s'appuie par sa deuxième extrémité, sur une face d'appui 2A de ladite contre-masse centrale.It can be seen in the figure that, in accordance with the invention, each of the pavilions is supported by at least part of its
On voit que ce type de montage dit "JANUS" se compose sensiblement de deux montages "TONPILZ" tels que décrits figures 1 et 2, qui seraient placés symétriquement par rapport à un axe transversal yy1, et qui auraient une contre-masse commune.We see that this type of assembly called "JANUS" consists essentially of two "TONPILZ" assemblies as described in FIGS. 1 and 2, which would be placed symmetrically with respect to a transverse axis yy1, and which would have a common counter-mass.
Dans le type de montage illustré figure 3, on fait vibrer en phase lesdits empilements de céramiques piézo-électriques situés d'un même côté dudit axe transversal yy1, et on fait vibrer avec une phase décalée de 180° lesdits empilements de céramiques piézo-électriques situés de l'autre côté dudit axe transversal yy1.In the type of assembly illustrated in FIG. 3, said stacks of piezoelectric ceramics are vibrated in phase located on the same side of said transverse axis yy1, and said stacks of piezoelectric ceramics are vibrated with a phase offset by 180 ° located on the other side of said transverse axis yy1.
On voit sur la figure que, de façon connue dans ce type de montage, le revêtement élastique 17 qui recouvre lesdits pavillons 1, entoure également lesdits empilements de céramiques piézo-électriques.It can be seen in the figure that, in a known manner in this type of mounting, the
Dans ce type de montage, l'ensemble constitué desdits pavillons, desdits empilements et de ladite contre-masse, revêtu dudit revêtement élastique 17, est introduit dans ledit boîtier et immobilisé dans celui-ci par des pièces 24 et 25 - généralement en forme de tubes - et de brides.In this type of assembly, the assembly consisting of said pavilions, said stacks and said counter-mass, coated with said
On voit également que la cavité 15 permettant le cheminement des fils d'alimentation desdites céramiques depuis celles-ci jusqu'au connecteur d'alimentation est située à l'intérieur de ladite contre-masse.It can also be seen that the
De façon connue, ce type de montage comporte des bafles 23, généralement réalisées en matériau alvéolaire, qui remplissent sensiblement l'espace compris entre ledit revêtement élastique et les parois dudit boîtier.In a known manner, this type of assembly comprises
Sur la figure 4, on a représenté une vue en coupe transversale à échelle réduite d'un mode de réalisation d'un transducteur électro-acoustique selon l'invention, dans un montage de type "FLEXTENSIONAL".In Figure 4, there is shown a cross-sectional view on a reduced scale of an embodiment of an electro-acoustic transducer according to the invention, in an assembly of the "FLEXTENSIONAL" type.
Le type de montage représenté est plus particulièrement celui dénommé "FLEXTENSIONAL" classe 4.The type of assembly shown is more particularly that called "FLEXTENSIONAL"
Dans ce type de montage, le boîtier dudit transducteur électro-acoustique est constitué par une coque 28, généralement en composite verre époxy, qui a une forme de cylindre d'axe perpendiculaire au plan de la figure 4, de section elliptique, dont le petit axe est porté par l'axe transversal yy1 et le grand axe est porté par l'axe longitudinal xx1.In this type of mounting, the housing of said electro-acoustic transducer is constituted by a
Lesdites pièces d'appui sont constituées habituellement dans ce montage par une âme 27 centrale et deux inserts 26, qui s'étendent selon un axe perpendiculaire au plan de la figure ; de part et d'autre dudit axe transversal yy1, sont habituellement, et de façon connue, disposés des empilements de céramiques, de forme allongée, qui sont appuyées à l'une de leurs extrémités sur un desdits inserts, préférentiellement par l'intermédiaire d'une glissière 41 et d'une cale 29, et à leur autre extrémité sur ladite âme; la précontrainte est réalisée dans ce type de montage par la coque elle-même, qui, lors du montage, est pincée selon son axe transversal yy1, afin qu'on introduise à l'intérieur l'ensemble constitué par lesdites glissières et cales, lesdits empilements et ladite âme, puis le pincement est relâché, ce qui tend à libérer ladite coque cylindrique selon ledit axe longitudinal xx1 et précontraindre ainsi lesdits empilements de céramique.Said support pieces are usually constituted in this assembly by a
On voit sur la figure que selon l'invention, on intercale de chaque côté de ladite âme, entre un premier empilement de céramiques 6 et un deuxième empilement de céramiques 7, qui est parallèle audit premier empilement, une pièce intermédiaire rigide 8, qui transmet la précontrainte entre lesdits premier et deuxième empilement.We see in the figure that according to the invention, there is interposed on each side of said core, between a first stack of
On voit qu'un revêtement élastique d'étanchéité 17 est prévu, qui entoure ladite coque.It can be seen that an
Le mode général de fonctionnement de ces transducteurs électro-acoustiques est sensiblement identique à celui du montage de la figure 3, hormis le principe de précontrainte par la coque explicité ci-dessus, et le principe de transmission des vibrations au milieu de propagation. Dans le montage de la figure 4, en effet, on utilise ladite coque de section elliptique comme amplificateur de mouvements vibratoires des inserts provoqués par lesdits empilements; en effet, lesdits mouvements vibratoires des inserts selon l'axe longitudinal xx1, occasionnent des mouvements vibratoires de plus grande amplitude, des parties de la coque qui s'étendent de part et d'autre de ces inserts, lesquels mouvements sont transmis au milieu extérieur de propagation.The general mode of operation of these electro-acoustic transducers is substantially identical to that of the assembly of FIG. 3, except for the principle of prestressing by the shell explained above, and the principle of transmission of vibrations to the propagation medium. In the assembly of FIG. 4, in fact, said shell of elliptical section is used as an amplifier of vibratory movements of the inserts caused by said stacks; in fact, said vibratory movements of the inserts along the longitudinal axis xx1, cause vibratory movements of greater amplitude, parts of the shell which extend on either side of these inserts, which movements are transmitted to the outside environment of propagation.
Sur la figure 5, on a représenté une vue en coupe transversale d'un mode de réalisation d'un transducteur électro-acoustique selon l'invention, dans un montage de type "TONPILZ" équipé d'éléments transducteurs magnétostrictifs.In Figure 5, there is shown a cross-sectional view of an embodiment of an electro-acoustic transducer according to the invention, in an assembly of the "TONPILZ" type equipped with magnetostrictive transducer elements.
Sur la figure 6, on a représenté une coupe selon VI-VI de la figure 5.In FIG. 6, a section along VI-VI of FIG. 5 is shown.
Dans ces figures, lesdits éléments transducteurs sont constitués par des barreaux 29 magnétostrictifs, qui sont susceptibles de vibrer selon leur axe longitudinal parallèle à l'axe xx1, sous l'effet du champ magnétique produit par des bobines 30.In these figures, said transducer elements consist of
Les barreaux si tués sur un même cercle d'axe xx1 sont reliés magnétiquement entre eux par des couronnes magnétiques 31 quine sont pas représentées sur la figure 6.The bars if killed on the same circle of axis xx1 are magnetically linked together by
Sur ces figures, on voit qu'un premier élément transducteur est constitué par quatre premiers barreaux situés à l'extérieur de la pièce intermédiaire rigide 8; lesquels quatre premiers barreaux s'appuient par une première de leurs extrémités respectives sur la face d'appui 1A du pavillon 1 par l'intermédiaire d'une couronne 31, et par leur deuxième extrémité et par l'intermédiaire d'une couronne 31 sur la première face d'appui de ladite pièce intermédiaire rigide qui est constituée dans ce mode de réalisation par quatre pattes 83.In these figures, it can be seen that a first transducer element is constituted by four first bars located outside the rigid
On voit qu'un deuxième élément transducteur est constitué par quatre deuxièmes barreaux situés à l'intérieur de la pièce intermédiaire rigide 8, lesquels quatre deuxièmes barreaux s'appuient par une première de leur extrémité et par l'intermédiaire d'une couronne 31 respectivement sur la face d'appui 2A de la contre-masse 2 et par leur deuxième extrémité et/ou par l'intermédiaire d'une deuxième couronne 31sur la deuxième face d'appui de ladite pièce intermédiaire rigide 8, qui est constituée par le fond 84, qui est traversé lui-même par la tige 4 de précontrainte.We see that a second transducer element is constituted by four second bars located inside the rigid
On voit sur la figure 6 que ladite pièce intermédiaire rigide comporte dans sa partie tubulaire centrale, une section en couronne qui épouse avantageusement sur sa périphérie le contour des bobines 30 desdits quatre premiers barreaux, et dont le profil interne épouse le contour des bobines 30 desdits quatre deuxièmes barreaux.It can be seen in FIG. 6 that said rigid intermediate piece comprises in its central tubular part, a crown section which advantageously follows the outline of the
Le domaine technique de l'invention est celui des transducteurs électro-acoustiques immergés.The technical field of the invention is that of immersed electro-acoustic transducers.
Claims (10)
- Electro-acoustic transducer enclosed in a case (3) and containing at least one first supporting component (1) and at least one second supporting component (2), containing at least two transducer units (6, 7) of elongated shape along a longitudinal axis (xx1) of said transducer, containing at least one pre-stressed rod (4) along said longitudinal axis (xx1) of said transducer units between said first and second supporting components, characterized in that said transducer units are arranged side by side and can vibrate in phase, and in that it contains at least one rigid intermediate unit (8) which is fitted in between said transducer units, in series with said transducer units.
- Transducer according to claim 1, characterized in that said transducer units each have two longitudinal flat parallel ends (A, B, C, D), and in that only the first end (A) of the first of said transducer units (6) is in contact with the first said supporting component (1), and in that only the first end (D) of the second of said transducer units (7) is in contact with said second supporting component (2), and in that said rigid intermediate unit (8) has two parallel faces (81, 82) with are in contact respectively with the second ends (B, C) of said transducer units (6, 7).
- Electro-acoustic transducer according to any one of claims 1 to 2, characterized in that each of said transducer units (6, 7) is made up of at least one magnetostrictive bar.
- Electro-acoustic transducer according to any one of claims 1 to 2, characterized in that said transducer units (6, 7) are each made up of at least one stack of piezo-electric ceramics, alternating with electrodes (10), forming an elongated cylinder.
- Electro-acoustic transducer according to any one of claims 1 to 4, characterized in that longitudinal gaps (9A, 9B) are respectively allowed for between said rigid intermediate unit (8) and said first and second supporting components (1, 2), such that during relative displacements between said supporting components due to forces developed by said transducer units (6, 7) and to the forces due to said pre-stressing device, contacts between said rigid intermediate unit and said supporting components are avoided.
- Electro-acoustic transducer according to any one of claims 1 to 5, characterized in that said rigid intermediate unit (8) is made up of a single rigid piece of metal.
- Electro-acoustic transducer according to any one of claims 1 to 5, characterized in that said intermediate unit is made up of at least two rigid intermediate components (8) and at least one intermediate transducer unit (8A, 8B, 8C, 8D) which is interposed between said two rigid intermediate components (8).
- Electro-acoustic transducer according to any one of claims 6 to 7, characterized in that said rigid component (8) is made up of a part that is almost cylindrical, with its axis parallel to said longitudinal axis (xx1), finishing at one end by a base (84) which contains one of said two parallel faces, which is in contact with the second end of said first transducer unit, and having at its other end an external collar which contains the other one of said two parallel faces, which is in contact with the second end of the second of said transducer units.
- Electro-acoustic transducer according to any one of claims 1 to 8, characterized in that the transverse sections of the active parts of said first and second transducer units (6, 7) are roughly equal.
- Manufacturing process for electro-acoustic transducers of the type containing at least one transducer unit of elongated shape, pre-stressed axially between two supporting components, characterized in that a first transducer unit of elongated shape, having only its first end in contact with one of the two supporting components and a second transducer unit of elongated shape, having only its first end in contact with the other supporting component, are fitted between said supporting components, said transducer units being parallel and side-by-side and functioning in phase, and in that an intermediate component which is in contact with both ends of said transducer units is interposed between these two transducer units, and in that the two transducer units and said intermediate component, which transmits the longitudinal forces between the two transducer units, are pre-stressed axially between the two supporting components.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR9007552A FR2663182B1 (en) | 1990-06-12 | 1990-06-12 | UNDERWATER ELECTRO-ACOUSTIC TRANSDUCER. |
FR9007552 | 1990-06-12 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0462037A1 EP0462037A1 (en) | 1991-12-18 |
EP0462037B1 true EP0462037B1 (en) | 1994-09-07 |
Family
ID=9397702
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP91430011A Expired - Lifetime EP0462037B1 (en) | 1990-06-12 | 1991-06-10 | Underwater electro-acoustic transducer |
Country Status (5)
Country | Link |
---|---|
US (1) | US5130953A (en) |
EP (1) | EP0462037B1 (en) |
CA (1) | CA2044335A1 (en) |
DE (1) | DE69103819D1 (en) |
FR (1) | FR2663182B1 (en) |
Families Citing this family (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5204844A (en) * | 1990-12-24 | 1993-04-20 | General Electric Company | Moment bender transducer |
FR2697711B1 (en) * | 1992-11-05 | 1994-12-30 | France Etat Armement | Method and transducer for emitting low frequency acoustic waves in a liquid in unlimited immersion. |
US5357486A (en) * | 1992-12-02 | 1994-10-18 | Innovative Transducers Inc. | Acoustic transducer |
FR2713429B1 (en) * | 1993-12-03 | 1996-02-09 | France Etat Armement | High power emission process for acoustic waves and corresponding transducer pavilions. |
EP0684085A1 (en) * | 1994-05-26 | 1995-11-29 | ETAT FRANCAIS Représenté par le Délégué Général pour l'Armement | Open sonar array comprising electroacoustic transducers |
FR2720586B1 (en) * | 1994-05-26 | 1996-07-05 | France Etat Armement | Sonar antenna with removable heads. |
FR2728425B1 (en) * | 1994-12-15 | 1997-01-31 | France Etat Armement | ELECTROACOUSTIC LINEAR TRANSMISSION ANTENNA AND TRANSMISSION / RECEPTION ANTENNA COMPRISING SUCH ANTENNA |
FR2731130B1 (en) * | 1995-02-23 | 1997-04-11 | France Etat | METHOD AND TRANSDUCERS FOR TRANSMITTING ACOUSTIC WAVES IN A LIQUID WITH LOW FREQUENCY DIRECTIVITY |
FR2731129B1 (en) * | 1995-02-23 | 1997-04-11 | France Etat | METHOD AND DEVICE FOR REDUCING THE RESONANCE FREQUENCY OF THE CAVITIES OF UNDERWATER TRANSDUCERS |
FR2731128B1 (en) * | 1995-02-23 | 1997-04-11 | France Etat | METHOD AND TRANSDUCERS UNDERGROUND IN A FLUID FOR THE TRANSMISSION OF LOW FREQUENCY ACOUSTIC WAVES WITH LIGHT PAVILIONS |
DE19512417C2 (en) * | 1995-04-03 | 1997-02-06 | Marco Systemanalyse Entw | Piezoelectric ultrasonic transducer |
US5615172A (en) * | 1996-04-22 | 1997-03-25 | Kotlyar; Oleg M. | Autonomous data transmission apparatus |
US6310427B1 (en) * | 2000-05-03 | 2001-10-30 | Bae Systems Aerospace Inc. | Connecting apparatus for electro-acoustic devices |
FR2818754B1 (en) * | 2000-12-21 | 2004-06-18 | Inst Francais Du Petrole | DEVICE FOR GENERATING FOCUSED ELASTIC WAVES IN A MATERIAL MEDIUM SUCH AS THE BASEMENT, AND METHOD FOR ITS IMPLEMENTATION |
EP1923145A1 (en) * | 2006-11-15 | 2008-05-21 | Nederlandse Organisatie voor toegepast-natuurwetenschappelijk Onderzoek TNO | Remote ultrasonic transducer system |
US7834490B1 (en) * | 2006-12-28 | 2010-11-16 | The United States Of America As Represented By The Secretary Of The Navy | Bimetallic strips for energy harvesting, actuation and sensing |
US7615912B2 (en) * | 2007-06-18 | 2009-11-10 | The Penn State Research Foundation | Acoustic transducer |
FR3001301B1 (en) * | 2013-01-24 | 2015-08-07 | Cggveritas Services Sa | APPARATUS AND METHOD FOR DETERMINING FAR-DOMAIN SIGNATURE FOR A SEISMIC SEISMIC MARINE SOURCE |
FR3029816B1 (en) * | 2014-12-15 | 2016-12-30 | Cedrat Tech | MODULAR AND IMMERSIBLE ULTRASONIC TUBULAR TRANSDUCER |
ES2602508B1 (en) * | 2015-07-16 | 2017-11-30 | Universidad De Granada | Ultrasonic torsion wave transmitter and transducer device comprising |
RU168468U1 (en) * | 2016-11-29 | 2017-02-06 | Закрытое акционерное общество "Руспром" | RECEIVING HYDROPHONE |
US11079506B2 (en) | 2016-12-16 | 2021-08-03 | Pgs Geophysical As | Multicomponent streamer |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3277436A (en) * | 1956-02-09 | 1966-10-04 | James W Fitzgerald | Hollow electro-acoustic transducer |
US3110825A (en) * | 1959-09-02 | 1963-11-12 | Clevite Corp | Folded transducer |
US3263210A (en) * | 1964-06-24 | 1966-07-26 | Schloss Fred | Wide band hydrophone |
US4072871A (en) * | 1974-05-20 | 1978-02-07 | Westinghouse Electric Corp. | Electroacoustic transducer |
FR2639786B1 (en) * | 1988-11-04 | 1991-07-26 | Thomson Csf | FLEXTENING TRANSDUCER |
-
1990
- 1990-06-12 FR FR9007552A patent/FR2663182B1/en not_active Expired - Lifetime
-
1991
- 1991-06-10 DE DE69103819T patent/DE69103819D1/en not_active Expired - Lifetime
- 1991-06-10 US US07/712,947 patent/US5130953A/en not_active Expired - Fee Related
- 1991-06-10 EP EP91430011A patent/EP0462037B1/en not_active Expired - Lifetime
- 1991-06-11 CA CA002044335A patent/CA2044335A1/en not_active Abandoned
Also Published As
Publication number | Publication date |
---|---|
US5130953A (en) | 1992-07-14 |
DE69103819D1 (en) | 1994-10-13 |
EP0462037A1 (en) | 1991-12-18 |
FR2663182B1 (en) | 1992-09-18 |
FR2663182A1 (en) | 1991-12-13 |
CA2044335A1 (en) | 1994-01-06 |
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