EP0247752A2 - Ultraschallgerätabstimmverfahren, Ultraschallgerät und Maschine zur Ultraschallbearbeitung - Google Patents

Ultraschallgerätabstimmverfahren, Ultraschallgerät und Maschine zur Ultraschallbearbeitung Download PDF

Info

Publication number
EP0247752A2
EP0247752A2 EP87304161A EP87304161A EP0247752A2 EP 0247752 A2 EP0247752 A2 EP 0247752A2 EP 87304161 A EP87304161 A EP 87304161A EP 87304161 A EP87304161 A EP 87304161A EP 0247752 A2 EP0247752 A2 EP 0247752A2
Authority
EP
European Patent Office
Prior art keywords
transducer
voltage
frequency
phase difference
ultrasonic
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.)
Withdrawn
Application number
EP87304161A
Other languages
English (en)
French (fr)
Other versions
EP0247752A3 (de
Inventor
Francis Frederick Hamilton Rawson
Brian Wilson
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of EP0247752A2 publication Critical patent/EP0247752A2/de
Publication of EP0247752A3 publication Critical patent/EP0247752A3/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • 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
    • B06B1/0207—Driving circuits
    • B06B1/0223—Driving circuits for generating signals continuous in time
    • B06B1/0238—Driving circuits for generating signals continuous in time of a single frequency, e.g. a sine-wave
    • B06B1/0246—Driving circuits for generating signals continuous in time of a single frequency, e.g. a sine-wave with a feedback signal
    • B06B1/0253—Driving circuits for generating signals continuous in time of a single frequency, e.g. a sine-wave with a feedback signal taken directly from the generator circuit
    • 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
    • B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
    • B06B2201/70—Specific application
    • B06B2201/72—Welding, joining, soldering

Definitions

  • This invention is concerned with improvements relating to ultrasonic devices, particularly devices comprising a transducer and a vibrator unit attached to the transducer in such a manner that, on the application of an oscillating voltage to drive the transducer, the vibrator unit (commonly known as a "horn”) vibrates at a high frequency.
  • the vibrator unit commonly known as a "horn”
  • An efficient way of operating an ultrasonic device is by the use of a power generator which drives the horn at its resonant frequency. It is thus necessary for the resonant frequency of a horn to be determined, and indeed in general horns are manufactured having specific resonant frequencies. The manufacture of a horn to a specific resonant frequency is a delicate and time consuming operation. Conventionally a horn is manufactured which has a resonant frequency below the desired frequency, and the horn is "tuned" by removal of metal so that the desired frequency is attained.
  • a tuner to which the horn may be attached comprising a transducer, to which the horn is connected, and a power generator to drive the transducer at a variable rate.
  • the frequency at which the transducer is driven is manually increased from a value below the resonant frequency of the horn, and the voltage across the transducer is measured. Below resonance the transducer is capacitive and above resonance the transducer is inductive, whilst at resonance, the transducer is purely resistive.
  • the resonant point can be determined when the impedence across a transducer is the minimum, and the frequency read off a scale provided on the power generator.
  • the horn is machined to increase its resonant frequency towards (but still below) the desired frequency, and is re-tested.
  • the minimum voltage point may not in fact correspond exactly to the point of minimum resistance across the transducer.
  • a horn may be tuned to a specific frequency to be driven by a power generator opeating at (or close to) that frequency, the resonant frequency of the horn will change to an extent dependant upon the load applied thereto, and power will be lost. Further, over longer periods of use, and/or with heavy loads, the resonant frequency of the horn may drift from its original resonant frequency, and the frequency may change with temperature.
  • a compensation circuit in the power generator for example comprising a bridge circuit having the transducer in one arm, to vary the frequency of the voltage of the power generator as the bridge circuit detects capacitance/inductance across the transducer.
  • a compensating mechanism to control the frequency applied to the transducer is limited.
  • the horn is driven at a frequency other than its resonant frequency, involving wastage of power, and unnecessary heating a wear on the power generator.
  • a method of tuning the horn of an ultrasonic device in which an oscillating voltage is applied to a transducer to which the horn is or may be connected, involving a comparison of the phase difference between the voltage applied to the transducer and the current flowing through the transducer.
  • the frequency of the oscillating voltage may be increased until, at resonance, the voltage and current will be in phase.
  • the resonant frequency of the horn may be determined with a significantly greater accuracy than has heretofore been practicable.
  • phase difference may be attained, corresponding to a "tuning out” of the induction or capacitance of the circuit.
  • a determination of the phase difference necessary for "tuning out” this inductance or capacitance may readily be established by measuring the phase difference whilst powering a horn of known resonant frequency at its resonant frequency.
  • the invention described above may additionally be used for the tuning and testing of transducers themselves, and accordingly this invention also provides a method of tuning and/or testing a transducer in which an oscillating voltage is applied to the transducer, the method involving a comparison of the phase difference between the voltage applied to the transducer and the current flowing through the transducer.
  • an ultrasonic device comprising a power generator adapted to provide an oscillating voltage of variable frequency to a transducer means whereby the frequency may be changed, and means whereby the phases of the voltage across the transducer and the current through the transducer may be compared.
  • the device comprises means by which a specific phase relationship may be determined, such means being manual (e.g. a super­imposition of the or part of the voltage and current traces on a screen) or automatic, e.g. by the use of microchip devices to compare the phases of specific parts of the traces, e.g. at maximum rates of increase or decrease.
  • the means may be such as to detect or assist in a manual detection of zero phase difference, or may be such as to detect or assist in a manual detection of a selected phase difference.
  • a more accurate determination of the resonant frequency of a horn may be determined by measurement of the frequency of generation at the point of the specific phase difference (e.g. zero in a simple circuit or equal to the "tuned out" inductance or capacitance in a complicated circuit).
  • an oscillating voltage of increasing or decreasing frequency may be applied to the transducer of an ultrasonic device, the voltage and current phase differences being continuously determined as hereinbefore described.
  • the circuit includes a means to maintain the frequency at phase equality (or desired inequality) such as a circuit branch comprising a phase-lock loop, thus ensuring that the device is driven at maximum efficency.
  • both the voltage and current wave forms are converted to square waves at their zero crossing points, and these signals are compared in frequency and phase relationship.
  • both current and voltage signals will be in-phase, this point being detected by a zero shift in the DC level at the intergrated output of the phase detector, the voltage conveniently being buffered by a high impedence voltage follower FET circuit which in turn drives the voltage control sinusoidal oscillator.
  • a machine for performing an ultrasonic tooling operation (such as ultrasonic welding, or ultrasonic drilling) on a workpiece
  • the machine comprising a transducer, a tool driven at ultrasonic frequency by the transducer, power generating means for driving the transducer, means for clamping a workpiece in relation to the tool, and means for causing relative movement of approach and separation between the clamping means and the tool, characterised in that the frequency at which the transducer is driven by the power generator is controlled as hereinbefore described.
  • the machine which is the preferred embodiment of this invention is a machine for performing an ultrasonic tooling operation on a workpiece, specifically an ultrasonic welding operation, and comprises a polygonal, specifically hexagonal, base 6, on a front panel 7 of which there are control operators provided, and on side panels adjacent to the front panel start buttons 8 are provided.
  • a power generator Located in the base 6 is a power generator, power being supplied therefrom to the transducer 14 by a cable 18.
  • a fixing plate 20 Mounted on the base between the rodless cylinders 10 is a fixing plate 20, comprising conventional means by which a workpiece, to be operated on by the tool 16, may be secured by conventional clamping means.
  • the two cylinders 20 are powered independently, so that one cylinder alone may be powered for the application of low loads between the tool and the workpiece, whilst both cylinders may be utilised when higher loads are required.
  • the machine is desirably of modular construction, enabling (for example) cylinders of different power to be substituted for the cylinders 10, dependent upon the machining requirements.
  • Figure 2 illustrates the circuity of the power generator, illustrating the power line of the circuitry, the whole system being grounded to earth, in a conventional manner.
  • MOSFET power amplifier Power is input into the circuit at point 30 to a MOSFET power amplifier: the advantages of utilising a MOSFET power amplifier is that, when several MOSFET transistors are used, they share power and limit tendency for cascade overload to occur.
  • a voltage monitor 40 is connected, the voltage monitor feeding a signal through a root mean square to DC conversion generator 42, which is applied to the indicator 38, and also to a voltage signal squaring and zero crossing detector 44.
  • a similar signal is applied from the current monitor 34 to a current signal squaring and zero crossing detector 46.
  • Outputs from the detectors 44 and 46 are applied to a phase comparator and error pulse generator 48, which compares the signals produced by the detectors 44 and 46, and produces an error signal proportional to the phase difference, or to the departure of the phase difference from a desired, preset phase difference.
  • the error signal is applied to an error pulse intergrator 50, the output of which is applied to an automatic/manual and reset circuit 52.
  • an output is applied to a ten-turn calibrated frequency controller 54 by which a manually/controlled signal is applied to a voltage-oscillator 58.
  • a preset signal is applied to a high impedence buffer and voltage follower 56, which in turn drives the voltage control oscillator 58.
  • a phase-lock loop circuit line 51 is applied backwardly from the circuit 52 to the integrator 50, to enable the circuit to continually "hunt" for a no-­error signal situation.
  • a display 60 is powered by the oscillator 58, and the output from the oscillator 58 is applied to a voltage controlled linear attenuator 62.
  • a comparator 64 which comprises a device 66 at which a set output voltage is applied, receives a signal from the convertor 42, and applies a comparative signal to the attenuator 60, ensuring that the voltage delivered by the attenuator 60 to the amplifier 32 is as set.
  • a desired voltage is applied to the output 36, at a frequency which ensures that the voltage and current signals are in-phase, or at a desired phase difference, and thus that the vibrator unit is operating at its resonant frequency.
  • a machine tool may be utilised in a manner which ensure maximum efficiency.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Apparatuses For Generation Of Mechanical Vibrations (AREA)
  • Transducers For Ultrasonic Waves (AREA)
EP87304161A 1986-05-12 1987-05-11 Ultraschallgerätabstimmverfahren, Ultraschallgerät und Maschine zur Ultraschallbearbeitung Withdrawn EP0247752A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8611510 1986-05-12
GB868611510A GB8611510D0 (en) 1986-05-12 1986-05-12 Ultrasonic devices

Publications (2)

Publication Number Publication Date
EP0247752A2 true EP0247752A2 (de) 1987-12-02
EP0247752A3 EP0247752A3 (de) 1988-08-03

Family

ID=10597719

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87304161A Withdrawn EP0247752A3 (de) 1986-05-12 1987-05-11 Ultraschallgerätabstimmverfahren, Ultraschallgerät und Maschine zur Ultraschallbearbeitung

Country Status (2)

Country Link
EP (1) EP0247752A3 (de)
GB (2) GB8611510D0 (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0359217A3 (de) * 1988-09-16 1991-11-13 Alcon Laboratories, Inc. Lineare Leistungskontrolle für eine Ultraschallsonde mit eingestellter Reaktanz
EP0328352B1 (de) * 1988-02-09 1995-01-11 Mettler Electronics Corporation Ultraschallerregungsanordnung mit Frequenzkontrolle an Hand von Musterdaten
EP0662356A3 (de) * 1994-01-05 1996-05-01 Branson Ultraschall Verfahren und Einrichtung zum Betrieb eines Generators zur HF-Energieversorgung eines Ultraschallwandlers.
CN1078306C (zh) * 1996-09-06 2002-01-23 株式会社久保田 柴油发动机的分割式燃烧室
WO2008113586A3 (de) * 2007-03-19 2008-12-04 Sauer Ultrasonic Gmbh Verfahren und vorrichtung zum betreiben eines ultraschallwerkzeugs

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2917691A (en) * 1956-07-10 1959-12-15 Aeroprojects Inc Automatic power and frequency control for electromechanical devices
GB990702A (en) * 1962-04-18 1965-04-28 George Andrew Douglas Gordon Ultrasonic transducers
US3447051A (en) * 1965-01-13 1969-05-27 Union Special Machine Co Control circuit for electro-mechanical devices
US3472063A (en) * 1967-04-17 1969-10-14 Branson Instr Resonant sensing device
US3743868A (en) * 1970-10-12 1973-07-03 Denki Onkyo Co Ltd Driving apparatus for piezoelectric ceramic elements
BE793601A (fr) * 1972-01-03 1973-07-02 Philips Nv Generateur d'ultrasons
US3743960A (en) * 1972-03-01 1973-07-03 Rca Corp Circuit for driving frequency standard such as tuning fork
US3808752A (en) * 1972-07-10 1974-05-07 Comtec Economation Method of automatically adjusting the frequency of crystal resonators
DE3120196C2 (de) * 1981-05-21 1985-02-14 Leybold-Heraeus GmbH, 5000 Köln Hochfrequenzgenerator für die Versorgung eines Massenspektrometers
EP0173761B1 (de) * 1984-09-04 1988-07-27 MED Inventio AG Leistungsgenerator für einen Ultraschallwandler

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0328352B1 (de) * 1988-02-09 1995-01-11 Mettler Electronics Corporation Ultraschallerregungsanordnung mit Frequenzkontrolle an Hand von Musterdaten
EP0359217A3 (de) * 1988-09-16 1991-11-13 Alcon Laboratories, Inc. Lineare Leistungskontrolle für eine Ultraschallsonde mit eingestellter Reaktanz
EP0662356A3 (de) * 1994-01-05 1996-05-01 Branson Ultraschall Verfahren und Einrichtung zum Betrieb eines Generators zur HF-Energieversorgung eines Ultraschallwandlers.
US5637947A (en) * 1994-01-05 1997-06-10 Technologies Gmbh & Co. Branson Ultraschall Niederlassung Der Emerson Method and apparatus for operating a generator supplying a high-frequency power to an ultrasonic transducer
CN1078306C (zh) * 1996-09-06 2002-01-23 株式会社久保田 柴油发动机的分割式燃烧室
WO2008113586A3 (de) * 2007-03-19 2008-12-04 Sauer Ultrasonic Gmbh Verfahren und vorrichtung zum betreiben eines ultraschallwerkzeugs

Also Published As

Publication number Publication date
GB8611510D0 (en) 1986-06-18
GB2192512A (en) 1988-01-13
GB8711147D0 (en) 1987-06-17
EP0247752A3 (de) 1988-08-03

Similar Documents

Publication Publication Date Title
US4277758A (en) Ultrasonic wave generating apparatus with voltage-controlled filter
US4748365A (en) Method and apparatus for supplying electric power to a vibration generator transducer
US5637947A (en) Method and apparatus for operating a generator supplying a high-frequency power to an ultrasonic transducer
US4562413A (en) Driving frequency controlling method for an ultrasonic transducer driving apparatus
US4056761A (en) Sonic transducer and drive circuit
US5074403A (en) Apparatus and method for two loop control of vibratory material feeders
EP0270819A3 (de) Lineare Leistungssteuerung eines Ultraschallwandlers mittels einer abgestimmten Reaktanz
EP0247752A2 (de) Ultraschallgerätabstimmverfahren, Ultraschallgerät und Maschine zur Ultraschallbearbeitung
JP2019155346A (ja) 超音波発振回路
US5046654A (en) Ultrasonic wire bonding apparatus
EP0216579B1 (de) Steuerung von Vibrationserregung
US5025227A (en) Metal detection circuit
US3636456A (en) Impedance-measuring network
JP2743752B2 (ja) レーザ加工装置
JP3235858B2 (ja) 共振型電磁振動機用制御装置
JPH05143168A (ja) 超音波発生器
JPH0234008A (ja) 超音波振動子の駆動装置
JPS5881469A (ja) 超音波加工用電源装置
JPH0671226A (ja) 超音波発生装置
US5122764A (en) Circuit for exciting a resonator
SU970161A1 (ru) Многоканальное устройство дл испытани изделий на полигармонические вибрации
US6076402A (en) Apparatus for detecting an exciting force externally exerted on a vibrating gyroscope
RU2025688C1 (ru) Устройство для испытания изделия на вибропрочность
JP2814011B2 (ja) 微小位置調整方法及び装置
JP2000084485A (ja) 超音波振動子の駆動装置

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: A2

Designated state(s): CH DE FR IT LI NL

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): CH DE FR IT LI NL

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19890204

RIN1 Information on inventor provided before grant (corrected)

Inventor name: WILSON,BRIAN

Inventor name: RAWSON,FRANCIS FREDERICK HAMILTON