EP0331591A1 - Elektroakustischer Kapsel mit Piezoelektrischer Membran - Google Patents

Elektroakustischer Kapsel mit Piezoelektrischer Membran Download PDF

Info

Publication number
EP0331591A1
EP0331591A1 EP89420071A EP89420071A EP0331591A1 EP 0331591 A1 EP0331591 A1 EP 0331591A1 EP 89420071 A EP89420071 A EP 89420071A EP 89420071 A EP89420071 A EP 89420071A EP 0331591 A1 EP0331591 A1 EP 0331591A1
Authority
EP
European Patent Office
Prior art keywords
cover
capsule
seal
periphery
capsule according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP89420071A
Other languages
English (en)
French (fr)
Inventor
Christian Cognasse
Peter Graham
Bernard Maury
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Horlogerie Photographique Francaise SA
Original Assignee
Horlogerie Photographique Francaise SA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Horlogerie Photographique Francaise SA filed Critical Horlogerie Photographique Francaise SA
Publication of EP0331591A1 publication Critical patent/EP0331591A1/de
Ceased legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/16—Mounting or tensioning of diaphragms or cones
    • H04R7/18—Mounting or tensioning of diaphragms or cones at the periphery
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers

Definitions

  • the present invention relates to electroacoustic transducers, the vibrating element of which consists of a membrane with a layer of piezoelectric material provided with electrodes and held around its periphery in a capsule case.
  • the housing comprises a base body provided with a central cavity, the periphery of which forms a bearing surface for the periphery of the piezoelectric membrane; the housing further comprises a cover connecting at its periphery to the base body, and comprising an internal recess communicating with the outside via at least one orifice.
  • the periphery of the cover has a rigid internal annular relief bearing on the periphery of the membrane to keep it pressed against a joint. annular interposed between said membrane and the periphery of the cavity of the base body.
  • the periphery of the cavity of the base body has a rigid annular relief forming a bearing surface, the membrane periphery being held against said annular relief by a annular seal interposed between the cover and the membrane.
  • the central base body cavity defines, with the piezoelectric membrane, a basic interior cavity.
  • the interior cover recess defines, with the piezoelectric membrane, an interior cover cavity.
  • the shape and dimensions of the interior base and cover cavities contribute significantly to determining the acoustic characteristics of the capsule.
  • the capsule is intended to be generally inserted in an external housing, and, in this case, the external face of the cover defines, with the wall of the housing, an external cavity whose dimensions and shape also contribute to the definition of the acoustic characteristics of the whole.
  • the capsule and the case in which it is inserted constitute a stack of elements which define several cavities whose shape and size very significantly influence the result.
  • transducer acoustics This stacking is generally carried out by automatic means, the joining being able to be ensured by welding, by crimping or any other means.
  • the piezoelectric membrane is maintained by the interposition of at least one annular seal which is a separate part.
  • the assembly requires a stacking of a relatively large number of elements, which results in a non-negligible production cost.
  • the object of the present invention is in particular to avoid the drawbacks of known methods and devices, by proposing a new capsule structure with a piezoelectric membrane making it possible to produce, with automatic assembly means, capsules having shapes and dimensions of interior cavities. accurately determinable; it follows that, according to the invention, the shape and the dimension of the internal cavities, as well as the bearing force of the retaining members of the periphery of the membrane, can be obtained with great regularity and great precision, and the this minimizes the problems associated with dispersion in the case of mass production.
  • the invention defines a capsule structure comprising means ensuring regular, precise and known adaptation with good certainty on the internal face of the outer casing in which the capsule is to be attached.
  • the number of elements to be assembled is significantly reduced during assembly of the capsule.
  • the problems usually associated with the use of seals are also avoided sealing, known and usable seals generally being of irregular dimensions, which induces flatness defects of the holding surfaces of the piezoelectric membrane.
  • Another object of the invention is to provide means making it possible to automate the manufacture of such a capsule as much as possible, by simultaneously producing, in a single operation, all of the seals intended on the one hand to maintain the piezoelectric membrane, and secondly to receive the wall of the outer casing into which the capsule is inserted.
  • the inner annular relief of the cover consists of an inner seal molded in injectable elastomer.
  • the seal is welded to the cover; it follows that no leakage is possible between the seal and the cover, and the sealing of the inner cavity of the cover around its periphery is substantially improved, and the sealing between the inner cavity of the cover and the inner cavity of basic body.
  • the cover further comprises an outer annular relief in injectable elastomer molded, for example of the same material as the inner seal, and forming an outer seal against which the wall of an outer housing can be pressed in which we insert the capsule.
  • the inner seal and the outer seal are connected to each other by bridges made of the same material as that constituting the seals, and passing through holes in the cover, distributed over the periphery of the cover.
  • overmolding operation is understood to mean either a traditional overmolding technique consisting in injecting the material constituting the seals into a mold containing the preformed cover, or a bi-injection technique in which the two operations of molding the cover and overmolding the seal can be provided by the same device in two successive phases close together.
  • the cover further comprises a rigid peripheral external annular relief, continuous or not, bordering the external seal and forming a reference surface to limit the crushing of the external seal during the insertion of the capsule in a box.
  • the size of the outer capsule cavity is thus determined precisely and constantly.
  • the cover further comprises a rigid peripheral internal annular relief, continuous or not, bordering the internal seal and forming a reference surface to limit the crushing of the internal seal during the production of the capsule by assembling its constituent parts.
  • the capsule according to the present invention comprises a piezoelectric membrane 1.
  • a piezoelectric membrane of known type composed of a thin metallic or insulating film, forming the base substrate of the membrane, and on which is secured at least one piezoelectric ceramic layer, the two faces of which are metallized and constitute the electrodes.
  • Electrical connection means for example of a known type, ensure the connection of the electrodes to output terminals such as terminal 2 intended to be connected to external electronic circuits.
  • the membrane 1, for example of substantially circular shape, is held around its periphery in a capsule case.
  • the housing comprises a base body 4 provided with a central cavity 5, the periphery of which forms a support surface 6 for the membrane periphery 1.
  • the support surface 6 is advantageously constituted by a rigid annular relief, on which rests the lower edge of the membrane 1.
  • the housing further comprises a cover 7, connecting at its periphery 8 to the base body 4.
  • the cover 7 and the base body 4 are connected to each other according to respective peripheral contact surfaces 9 and 10 determined with precision, to achieve an easily reproducible assembly.
  • the cover 7 has an internal recess 11 communicating with the outside through a series of orifices such as the orifice 12, regularly distributed in the wall of the cover as shown in the figures.
  • the cover recess 11 defines an interior cover cavity;
  • the central base body cavity 5 defines an interior base body cavity; the interior cavities are separated from each other by the piezoelectric membrane 1.
  • the periphery of the cover 7 has an internal annular relief 13, in abutment on the membrane periphery, that is to say in abutment on the upper periphery of the membrane, the annular relief 13 consisting of an internal seal molded in injectable elastomer. It is advantageous to use an injectable elastomer marketed under the brand name ALCRYN by the company DU PONT DE NEMOURS.
  • the interior annular relief 13 forming an interior seal can be molded into an annular groove in the interior face of the cover, as shown in section in FIG. 2.
  • the cover 7 further comprises an external annular relief 14 also made of molded injectable elastomer, for example of the same material as the internal annular relief 13, and forming an external seal against which the wall of an external casing can be pressed. insert the capsule.
  • This outer casing wall is schematically represented by the dashed line 15 in FIG. 2.
  • the cover 7 also comprises an external annular relief rigid device 16, continuous or not, externally bordering the external seal 14, and forming a reference surface to limit the crushing of the external seal 14 during insertion of the capsule against the wall 15 of an external casing.
  • the external annular relief significantly facilitates centering during assembly of the capsule.
  • the inner seal 13 and the outer seal 14 are advantageously connected to each other by at least one bridge of material such as the bridge 17.
  • a hole or a series of through holes are regularly provided in the cover 7. distributed over the periphery as shown in Figure 1, the holes for the simultaneous injection of material and its distribution by forming at the same time the outer seal 14, the bridges 17 and the inner seal 13, by molding the cover.
  • the inner 13 and outer 14 seals each form a continuous ring.
  • the inner seal and / or the outer seal can be discontinuous, to define for example a radial passage for connectors or other elements. Such a discontinuity would be difficult to achieve if an added seal is used. This would indeed cause great difficulties in positioning and preparing the seals.
  • the cover 7 can be produced in two successive operations separated from one another: a first operation of molding the rigid shell forming the main structure of the cover; a second operation consisting in overmolding the prefabricated rigid shell, in a mold, by injecting the material intended to form the seals 13 and 14.
  • such a cover can be produced by a bi-injection technique, in two close phases, a first injection phase for forming the rigid cover shell, a second phase of injection of the material which should form the seals. 13 and 14.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Piezo-Electric Transducers For Audible Bands (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
EP89420071A 1988-03-01 1989-02-27 Elektroakustischer Kapsel mit Piezoelektrischer Membran Ceased EP0331591A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8802969 1988-03-01
FR8802969A FR2628282B1 (fr) 1988-03-01 1988-03-01 Capsule electroacoustique a membrane piezoelectrique

Publications (1)

Publication Number Publication Date
EP0331591A1 true EP0331591A1 (de) 1989-09-06

Family

ID=9364039

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89420071A Ceased EP0331591A1 (de) 1988-03-01 1989-02-27 Elektroakustischer Kapsel mit Piezoelektrischer Membran

Country Status (3)

Country Link
EP (1) EP0331591A1 (de)
JP (1) JPH0214700A (de)
FR (1) FR2628282B1 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0475208A3 (en) * 1990-08-30 1992-10-14 S. Eletro-Acustica S.A. Electroacoustic piezoelectric transducer
EP0595514A3 (en) * 1992-10-27 1996-10-09 Tdk Corp Piezoelectric transducer
CN112291690A (zh) * 2019-07-22 2021-01-29 英飞凌科技股份有限公司 压力传感器

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1334235A (fr) * 1961-09-29 1963-08-02 Siemens Ag Transformateur électro-acoustique
DE2123649A1 (de) * 1971-05-12 1972-11-16 Siemens AG, 1000 Berlin u. 8000 München Akustischer Koppler
FR2275182A1 (fr) * 1974-06-18 1976-01-16 Speidel Blasius Microphone a contact pour mesurer la pression du sang
FR2337480A1 (fr) * 1975-12-30 1977-07-29 Sits Soc It Telecom Siemens Transducteur electro-acoustique, en particulier du type a plaque piezoceramique

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1334235A (fr) * 1961-09-29 1963-08-02 Siemens Ag Transformateur électro-acoustique
DE2123649A1 (de) * 1971-05-12 1972-11-16 Siemens AG, 1000 Berlin u. 8000 München Akustischer Koppler
FR2275182A1 (fr) * 1974-06-18 1976-01-16 Speidel Blasius Microphone a contact pour mesurer la pression du sang
FR2337480A1 (fr) * 1975-12-30 1977-07-29 Sits Soc It Telecom Siemens Transducteur electro-acoustique, en particulier du type a plaque piezoceramique

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0475208A3 (en) * 1990-08-30 1992-10-14 S. Eletro-Acustica S.A. Electroacoustic piezoelectric transducer
US5245669A (en) * 1990-08-30 1993-09-14 Leson Laboratorio De Engenharia Sonica S.A. Electroacoustic transducer
EP0595514A3 (en) * 1992-10-27 1996-10-09 Tdk Corp Piezoelectric transducer
CN112291690A (zh) * 2019-07-22 2021-01-29 英飞凌科技股份有限公司 压力传感器
CN112291690B (zh) * 2019-07-22 2024-04-05 英飞凌科技股份有限公司 压力传感器

Also Published As

Publication number Publication date
JPH0214700A (ja) 1990-01-18
FR2628282B1 (fr) 1990-08-24
FR2628282A1 (fr) 1989-09-08

Similar Documents

Publication Publication Date Title
EP0650620B1 (de) Verfahren zur herstellung einer karte, die mindestens einen elektronischen baustein enthält,und nach einem solchen verfahren hergestellte karte
EP0289892B1 (de) Magnetische Befestigungsvorrichtung, insbesondere für Zahnprothesen
FR2819036A1 (fr) Soupape et generateur electrochimique comprenant une telle soupape
FR2629660A1 (fr) Capsule piezoelectrique a pinces de connection electrique laterales
FR2508667A1 (fr) Procede et moyens pour monter de facon etanche une pile dans une boite de montre
EP0331591A1 (de) Elektroakustischer Kapsel mit Piezoelektrischer Membran
EP0726408A1 (de) Vibrationsdämpfende hydraulische Stütze und deren Herstellungsverfahren
LU82759A1 (fr) Pile electrique etanche
EP0825128B1 (de) Element zur Befestigung einer Abgabevorrichtung an einem Behälterhals
EP4211504B1 (de) Dichtung für eine kabelspleissbox
FR2909743A1 (fr) Joint d'etancheite.
EP0972103A1 (de) Wasserreservoir für dampfbügeleisen und verfahren zur herstellung eines derartigen reservoirs
CA2109465C (fr) Dispositif d'etancheite de moteurs electro-acoustiques
FR2465321A1 (fr) Element galvanique comprenant un carter ferme de maniere etanche et procede servant a sa fabrication
EP0385888A1 (de) Piezoelektrische Kapsel mit leitenden elastischen Halterungsgliedern
FR2526335A1 (fr) Organe de transmission a noyau flottant propre notamment a l'assistance ultrasonique d'un quelconque traitement, et application en particulier au compactage et au trefilage
FR2783915A1 (fr) Transducteur ultrasonore
FR2862447A1 (fr) Bride pour boitier de servitude d'un moteur de vehicule motorise, et boitier equipe de cette bride.
FR2490439A1 (fr) Transducteur electrodynamique en particulier pour la telephonie
FR2809228A1 (fr) Moule d'injection pour la fabrication d'un boitier semi- conducteur optique et boitier semi-conducteur optique
FR2605145A1 (fr) Module solaire du type photovoltaique, son procede de fabrication et support de moulage pour la mise en oeuvre de ce procede
FR2940534A1 (fr) Joint d'etancheite monofilaire a grande longevite.
FR3157079A1 (fr) Boîtier pour un produit cosmétique pulvérulent
CH683634A5 (fr) Clapet intégré et micropompe comprenant un tel clapet.
EP1176384A2 (de) Pyrotechnischer Zünder mit einem elektrischen oder elektronischen Bauelement und/oder mit einem Steckverbinder

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE

17P Request for examination filed

Effective date: 19900213

17Q First examination report despatched

Effective date: 19920331

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 19920921