EP0053947B1 - Ultraschallwandler - Google Patents

Ultraschallwandler Download PDF

Info

Publication number
EP0053947B1
EP0053947B1 EP81305827A EP81305827A EP0053947B1 EP 0053947 B1 EP0053947 B1 EP 0053947B1 EP 81305827 A EP81305827 A EP 81305827A EP 81305827 A EP81305827 A EP 81305827A EP 0053947 B1 EP0053947 B1 EP 0053947B1
Authority
EP
European Patent Office
Prior art keywords
diaphragm
ultrasonic transducer
housing
laminated piezo
buffer member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP81305827A
Other languages
English (en)
French (fr)
Other versions
EP0053947A1 (de
Inventor
Ryoichi Takayama
Yukihiko Ise
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Publication of EP0053947A1 publication Critical patent/EP0053947A1/de
Application granted granted Critical
Publication of EP0053947B1 publication Critical patent/EP0053947B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • 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
    • G10K9/122—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated using piezoelectric driving means
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • H04R17/10—Resonant transducers, i.e. adapted to produce maximum output at a predetermined frequency

Definitions

  • This invention relates to an ultrasonic transducer using a laminated piezo-electric element, and more particularly to an ultrasonic transducer with improved sensitivity characteristics and improved pulse characteristics (transition characteristics).
  • Ultrasonic transducers for use in the air have been proposed and include laminated piezo-electric ceramic elements which are designed to work at resonance or anti-resonance points. Further, because the mechanical impedance of air is substantially smaller than that of the piezo-electric ceramic element, the laminated element is bonded to a diaphragm in an attempt to reduce mechanical impedance.
  • Patent US-A-3786202 discloses an acoustic transducer in which a piezo electric element is supported at its central portion by a conical diaphragm which is contacted at its rim by the transducer housing.
  • the present invention provides an ultrasonic transducer comprising a laminated piezo-electric disc-shaped element, a conical diaphragm connected at its apex to the centre of said element and thereby supporting said element, and a housing for accommodating said laminated piezo-electric element therein, characterised in that a buffer member is disposed between and in contact with the periphery of said diaphragm and an inner side wall of said housing, wherein said diaphragm is flexibly fixed and held within said housing through the use of said buffer member.
  • An advantage of a preferred form of the transducer is that response time of the transducer is shorter. Further, the transducer exhibits excellent transmission sensitivity and directivity.
  • the diaphragm is disposed at the centre of the laminated piezo-electric element and the periphery of the diaphragm is flexibly secured on a housing by way of a buffer member made of elastic rubber or the like so as to suppress mechanical oscillation.
  • an end of a coupling shaft 2 is fixed to pass through a central portion of a laminated piezo-electric element 1 with the remaining end thereof being secured to a diaphragm 3.
  • the laminated piezo-electric element 1 is mounted at nodes of oscillation via a flexible adhesive 5 on tips of supports 4.
  • terminals 6 and 6' There is further provided terminals 6 and 6', a housing 7 for protecting the laminated piezo-electric element 1 and so forth against the outside world, a protective mesh 8 disposed at a top portion of the housing and lead wires 9 and 9' for electrically connecting the laminated piezo-electric element 1 to the terminals 6 and 6'.
  • Figure 2 depicts the waveform of radiation transmitted when the ultrasonic transducer is supplied with a plurality of pulses. It will be noted that the response of the transducer, i.e. the rise time and fall time, is of the order of 2 milliseconds for each response.
  • FIG. 3 is a cross sectional view of an ultrasonic transducer according to a first embodiment of the present invention.
  • a diaphragm 13 typically of metal or plastics is fixed to a coupling shaft 12 which is disposed at a central portion of a laminated piezo-electric element 11 made of a suitable piezo-electric ceramic material.
  • the diaphragm 13 is of a conical configuration and the laminated piezo-electric element 11 is in the shape of a disc.
  • a peripheral portion of the diaphragm 13 is flexibly secured to an inner side wall of a cylindrical housing 17 through the use of an annular buffer member 20 of a resilient material such as rubber or the like in order to suppress mechanical oscillation.
  • the diaphragm 13 and the laminated piezo-electric element 11 are disposed at the centre of the housing 17 through the buffer member 20.
  • a pair of terminals 16 and 16' are electrically connected to the laminated piezo-electric element 11 via lead wires 19 and 19'.
  • Figure 4 depicts the pulse characteristics of the ultrasonic transducer of the above described structure, indicating that the rise time and fall time of a pulse were less than 0.2 millisecond.
  • Figure 5 indicates the rise time and directivity (acoustic pressure half-angle) as a function of the inner diameter of the annular buffer member 20.
  • the diameter of the diaphragm 3 was 16 mm.
  • Figure 6 is a graph showing the relationship between the diameter of the diaphragm 13 provided for the disc-like laminated piezo-electric element (diameter: 10 mm) and transmission sensitivity, indicating that the greater the diameter of the diaphragm 13 the greater transmission sensitivity.
  • Figure 7 is a graph showing the relationship between the diameter of the diaphragm 13 and directivity (acoustic pressure half-angle). It is clear from Figure 7 that the ultrasonic transducer manifests acute directivity when the diaphragm of a diameter becomes greater.
  • Figure 8 shows the relationship between the angle of the top of the conical diaphragm 13 and directivity. The sharpest directivity was obtained when the conical diaphragm with 0.3-0.5 of height(h)-to-bottom diameter (R) ratio was used.
  • FIG. 9 is a cross sectional view of an ultrasonic transducer according to another embodiment of the present invention.
  • a diaphragm 21 typically of metal or plastics is fixed to a coupling shaft 23 which is disposed at a central portion of a laminated piezo-electric element 22 made of a proper piezo-electric ceramic material.
  • a peripheral portion of the diaphragm 21 is fixedly secured in an inner side wall of a cylindrical housing 25 through the use of an annular buffer member 24 of resilient material such as rubber or the like to suppress mechanical oscillation.
  • an acoustic absorbent material 26 is disposed at the bottom of the housing 25.
  • a pair of terminals 27 and 27' are connected electrically to the laminated piezo-electric element 22 via lead wires 28 and 28'.
  • the distinction of the ultrasonic transducer as shown in Figure 9 from that of Figure 3 is the provision of the acoustic absorbent material 26 on the bottom wall of the housing 25.
  • the provision of the acoustic absorbent material 26 assures further improvement in the pulse characteristics.
  • Figure 10 The pulse characteristics of the ultrasonic transducer of the above detailed structure are depicted in Figure 10, which indicates that the rise time and fall time of a pulse were shorter than 0.1 ms. It is noted that Figure 10 was plotted with pulse envelop lines although there were in fact three or four waves before the pulse rose completely.
  • Figure 11 shows the effect of the above described acoustic absorbent material 26 on the pulse characteristics, indicating a remarkable improvement in the rise time.
  • Figure 12 represents the relationship between the inner diameter of the annular buffer member 24 and the rise time and fall time.
  • the diaphragm 21 used had a bottom diameter of 16 mm and the laminated piezo-electric element 22 was of a diameter of 10 mm and a thickness of 0.5 mm.
  • Figure 14 depicts the temperature dependency of the pulse characteristics and transmission sensitivity. As compared with those at 20°C, the rise time showed no substantial variation at -20°C and increased by 12% at 60°C while the transmission sensitivity declined by 5% at -20°C and increased by 5% at 60°C. It is understood that the pulse characteristics showed no variation even when the protective mesh was disposed at the front of the housing 17.
  • the ultrasonic transducer shows improved pulse characteristics and improved transmission sensitivity as well as a shortened pulse rise time and fall time. Furthermore, it is stronger and simpler in structure with a lower profile and is easier to assemble than the previously proposed device, all as a result of flexibly fixing and holding the diaphragm within the housing.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Transducers For Ultrasonic Waves (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)

Claims (3)

1. Ultraschallwandler mit einem laminierten, scheibenförmigen piezoelektrischen Element (11), einer kegelförmigen Membrane (13), welche an ihrem Scheitel mit dem Mittelpunkt des Elements (11) verbunden ist und das Element (11) dadurch trägt, und einem Gehäuse (17) für die Unterbringung des laminierten piezoelektrischen Elements darin, dadurch gekennzeichnet, daß ein Pufferelement (20) zwischen dem Umfang der Membrane (13), und in Berührung damit, und einer inneren Seitenwand des Gehäuses (17) angeordnet ist, wodurch die Membrane (13) durch die Verwendung des Pufferelements (20) flexibel fixiert und in dem Gehäuse (17) gehalten ist.
2. Ultraschallwandler nach Anspruch 1, dadurch gekennzeichnet, daß die kegelförmige Membrane (13) ein Verhältnis von 0,3 bis 0,5 zwischen ihrer Höhe und ihrem Bodendurchmesser aufweist.
3. Ultraschallwandler nach Anspruch 2, dadurch gekennzeichnet, daß ein akustisch absorbierendes Material (26) innerhalb des Gehäuses (17) angeordnet ist.
EP81305827A 1980-12-10 1981-12-10 Ultraschallwandler Expired EP0053947B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP174328/80 1980-12-10
JP17432880A JPS6025956B2 (ja) 1980-12-10 1980-12-10 超音波送受波器

Publications (2)

Publication Number Publication Date
EP0053947A1 EP0053947A1 (de) 1982-06-16
EP0053947B1 true EP0053947B1 (de) 1985-10-30

Family

ID=15976713

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81305827A Expired EP0053947B1 (de) 1980-12-10 1981-12-10 Ultraschallwandler

Country Status (4)

Country Link
EP (1) EP0053947B1 (de)
JP (1) JPS6025956B2 (de)
CA (1) CA1180100A (de)
DE (1) DE3172788D1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7241207B2 (en) 2002-08-21 2007-07-10 Jurgen Heesemann Grinding machine and method for grinding a workpiece

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5851697A (ja) * 1981-09-22 1983-03-26 Matsushita Electric Ind Co Ltd 超音波送受波器
US4607186A (en) * 1981-11-17 1986-08-19 Matsushita Electric Industrial Co. Ltd. Ultrasonic transducer with a piezoelectric element
DE8712014U1 (de) * 1987-09-04 1987-10-29 Chen, Ding Pang, Taipeh/T'ai-pei Umfangselement für einen Lautsprecher
GB2215049B (en) * 1988-02-02 1991-08-21 Stc Plc Acoustic devices
IT1262971B (it) * 1992-08-05 1996-07-23 Imapo Srl Piezomembrana vincolata al centro e suo impiego per la realizzazione di avvisatore acustico.
CN1107831C (zh) * 1997-02-03 2003-05-07 斯瓦戈洛克公司 流量控制装置
DE102016117879B4 (de) * 2016-09-22 2019-06-13 Valeo Schalter Und Sensoren Gmbh Sensorsystem, Kraftfahrzeug und Verfahren zum Reinigen eines Ultraschallsensors

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4190783A (en) * 1978-07-25 1980-02-26 The Stoneleigh Trust, Fred M. Dellorfano, Jr. & Donald P. Massa, Trustees Electroacoustic transducers of the bi-laminar flexural vibrating type with an acoustic delay line
US4190784A (en) * 1978-07-25 1980-02-26 The Stoneleigh Trust, Fred M. Dellorfano, Jr. & Donald P. Massa, Trustees Piezoelectric electroacoustic transducers of the bi-laminar flexural vibrating type

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1301808A (fr) * 1960-09-06 1962-08-24 Vega Haut-parleur perfectionné pour fréquences aiguës
US3360664A (en) * 1964-10-30 1967-12-26 Gen Dynamics Corp Electromechanical apparatus
GB1316811A (en) * 1969-05-22 1973-05-16 Matsushita Electric Ind Co Ltd Microphone
US3786202A (en) * 1972-04-10 1974-01-15 Motorola Inc Acoustic transducer including piezoelectric driving element
US4011473A (en) * 1974-08-26 1977-03-08 Fred M. Dellorfano, Jr. & Donald P. Massa, Trustees Of The Stoneleigh Trust Ultrasonic transducer with improved transient response and method for utilizing transducer to increase accuracy of measurement of an ultrasonic flow meter

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4190783A (en) * 1978-07-25 1980-02-26 The Stoneleigh Trust, Fred M. Dellorfano, Jr. & Donald P. Massa, Trustees Electroacoustic transducers of the bi-laminar flexural vibrating type with an acoustic delay line
US4190784A (en) * 1978-07-25 1980-02-26 The Stoneleigh Trust, Fred M. Dellorfano, Jr. & Donald P. Massa, Trustees Piezoelectric electroacoustic transducers of the bi-laminar flexural vibrating type

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7241207B2 (en) 2002-08-21 2007-07-10 Jurgen Heesemann Grinding machine and method for grinding a workpiece

Also Published As

Publication number Publication date
JPS5797798A (en) 1982-06-17
DE3172788D1 (en) 1985-12-05
JPS6025956B2 (ja) 1985-06-21
EP0053947A1 (de) 1982-06-16
CA1180100A (en) 1984-12-27

Similar Documents

Publication Publication Date Title
US4458170A (en) Ultrasonic transmitter-receiver
US4127749A (en) Microphone capable of cancelling mechanical generated noise
US5789844A (en) Acoustic transducer
US4607186A (en) Ultrasonic transducer with a piezoelectric element
JPS6133519B2 (de)
EP0142215A3 (de) Ultraschallwandler mit verbesserten Schwingungsweisen
EP0053947B1 (de) Ultraschallwandler
GB2063006A (en) Directional transducer
GB1513530A (en) Piezoelectric transducers
WO1989005199A1 (en) An acoustic emission transducer and an electrical oscillator
US4456848A (en) Ultrasonic transmitting and receiving device
US3253674A (en) Ceramic microphone
JP2623643B2 (ja) 超音波セラミックマイクロホン
JPS6055798A (ja) 超音波送受波器
JPS5884600A (ja) 超音波送受波器
JPS6025957B2 (ja) 超音波送受波器
SU997833A1 (ru) Электроакустический преобразователь
JPS58124400A (ja) 超音波送受波器
JPS642320B2 (de)
JPS6321582A (ja) 超音波送受波器
JPS58124398A (ja) 超音波送受波器
JPS5851698A (ja) 超音波送受波器
JPS6126397A (ja) 超音波送受波器
JPS58124399A (ja) 超音波送受波器
JPS5797799A (en) Ultrasonic wave transmitter and receiver

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

Designated state(s): DE FR GB

17P Request for examination filed

Effective date: 19821129

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 3172788

Country of ref document: DE

Date of ref document: 19851205

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19941130

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19941208

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19941209

Year of fee payment: 14

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19951210

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19951210

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19960830

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19960903

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST