BE905451A - Jauge de contrainte pour detecter des efforts ou deformations dans des organes ou structures. - Google Patents

Jauge de contrainte pour detecter des efforts ou deformations dans des organes ou structures.

Info

Publication number
BE905451A
BE905451A BE0/217180A BE217180A BE905451A BE 905451 A BE905451 A BE 905451A BE 0/217180 A BE0/217180 A BE 0/217180A BE 217180 A BE217180 A BE 217180A BE 905451 A BE905451 A BE 905451A
Authority
BE
Belgium
Prior art keywords
deformations
bodies
structures
stress gauge
efforts
Prior art date
Application number
BE0/217180A
Other languages
English (en)
French (fr)
Inventor
Dell Orto Giuseppe
Rossi Giuseppina
Giuseppe Dell Orto
Giuseppina Rossi
Original Assignee
Marelli Autronica
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 Marelli Autronica filed Critical Marelli Autronica
Publication of BE905451A publication Critical patent/BE905451A/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
    • G01L1/22—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges
    • G01L1/2206—Special supports with preselected places to mount the resistance strain gauges; Mounting of supports
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
    • G01B7/18—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in resistance
    • G01B7/20—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in resistance formed by printed-circuit technique
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
    • G01L1/22—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges
    • G01L1/2206—Special supports with preselected places to mount the resistance strain gauges; Mounting of supports
    • G01L1/2218—Special supports with preselected places to mount the resistance strain gauges; Mounting of supports the supports being of the column type, e.g. cylindric, adapted for measuring a force along a single direction
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
    • G01L1/22—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges
    • G01L1/2206—Special supports with preselected places to mount the resistance strain gauges; Mounting of supports
    • G01L1/2218—Special supports with preselected places to mount the resistance strain gauges; Mounting of supports the supports being of the column type, e.g. cylindric, adapted for measuring a force along a single direction
    • G01L1/2225—Special supports with preselected places to mount the resistance strain gauges; Mounting of supports the supports being of the column type, e.g. cylindric, adapted for measuring a force along a single direction the direction being perpendicular to the central axis
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
    • G01L1/22—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges
    • G01L1/2287—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges constructional details of the strain gauges
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
    • G01L1/22—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges
    • G01L1/2287—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges constructional details of the strain gauges
    • G01L1/2293—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges constructional details of the strain gauges of the semi-conductor type
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
    • G01R31/14—Circuits therefor, e.g. for generating test voltages, sensing circuits
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/38—Concrete; Lime; Mortar; Gypsum; Bricks; Ceramics; Glass
    • G01N33/388—Ceramics

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Measurement Of Force In General (AREA)
BE0/217180A 1985-09-17 1986-09-17 Jauge de contrainte pour detecter des efforts ou deformations dans des organes ou structures. BE905451A (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT8553804U IT206727Z2 (it) 1985-09-17 1985-09-17 Sensore estensimetrico a film spesso per la rilevazione di sforzi e deformazioni in organi o strutture meccaniche

Publications (1)

Publication Number Publication Date
BE905451A true BE905451A (fr) 1987-01-16

Family

ID=11285267

Family Applications (1)

Application Number Title Priority Date Filing Date
BE0/217180A BE905451A (fr) 1985-09-17 1986-09-17 Jauge de contrainte pour detecter des efforts ou deformations dans des organes ou structures.

Country Status (11)

Country Link
US (1) US4793189A (US07943777-20110517-C00090.png)
JP (1) JP2514502Y2 (US07943777-20110517-C00090.png)
BE (1) BE905451A (US07943777-20110517-C00090.png)
CH (1) CH669994A5 (US07943777-20110517-C00090.png)
DE (1) DE3631647C2 (US07943777-20110517-C00090.png)
ES (1) ES2003115A6 (US07943777-20110517-C00090.png)
FR (1) FR2587484B1 (US07943777-20110517-C00090.png)
GB (1) GB2184239B (US07943777-20110517-C00090.png)
IT (1) IT206727Z2 (US07943777-20110517-C00090.png)
NL (1) NL8602362A (US07943777-20110517-C00090.png)
PT (1) PT83393B (US07943777-20110517-C00090.png)

Families Citing this family (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2234629B (en) * 1989-06-28 1993-01-27 Ivor John Martin Fehr Improvements relating to strain gauges
JPH05508117A (ja) * 1990-02-27 1993-11-18 メリーランド大学　カレッジ　パーク校 任意方向において物体に作用を与えかつ検出を行うための方法と装置
US5440193A (en) * 1990-02-27 1995-08-08 University Of Maryland Method and apparatus for structural, actuation and sensing in a desired direction
US5140849A (en) * 1990-07-30 1992-08-25 Agency Of Industrial Science And Technology Rolling bearing with a sensor unit
JPH05141907A (ja) * 1991-09-24 1993-06-08 Tokyo Electric Co Ltd 歪センサ及びその製造方法並びにその歪センサを使用したロードセル秤
DE4206577A1 (de) * 1992-03-02 1993-09-09 Hottinger Messtechnik Baldwin Einrichtung und verfahren zur ermittlung der verformung eines bauteils und verfahren zur montage der einrichtung
US5528151A (en) * 1992-11-09 1996-06-18 Hughes Aircraft Company Thermal fatigue testing using plural test trips with graduated sizing and recessed anchoring
FR2701317B1 (fr) * 1993-02-09 1995-03-31 Thomson Csf Dispositif de mesure d'efforts exercés sur une pièce mécanique et procédé de fixation.
GB2310288B (en) * 1996-02-17 1999-09-29 John Karl Atkinson A force sensitive device
DE19907673A1 (de) * 1999-02-23 2000-08-31 Klaus Dietzel Meßeinrichtung mit Smarttransponder an Schlauchleitungen
US6378384B1 (en) 1999-08-04 2002-04-30 C-Cubed Limited Force sensing transducer and apparatus
DE10023838C2 (de) * 2000-05-16 2002-11-28 Siemens Ag Vorrichtung zum Messen einer Wegänderung zwischen Abschnitten eines Bauteils und Verwendung dieser Vorrichtung
JP4583576B2 (ja) * 2000-10-19 2010-11-17 富士重工業株式会社 繊維強化樹脂複合材の損傷位置検出装置および損傷検出センサーの製造方法
DE10134586A1 (de) * 2001-07-17 2003-02-06 Siemens Ag Sensoreinrichtung zum Erfassen einer Dehnungsbeanspruchung
DE10225549B4 (de) * 2002-06-06 2007-12-06 Siemens Ag Verfahren und Anordnung zum Erfassen von mechanischen Krafteinwirkungen auf einen Bauelementträger für elektrische Bauelemente
JP2004301508A (ja) * 2003-03-28 2004-10-28 Matsushita Electric Ind Co Ltd トルクセンサおよびそれを用いた操舵トルク検出装置
DE10335690A1 (de) * 2003-06-04 2004-12-23 Sensor-Technik Wiedemann Gmbh Verformungssensor
FR2867275B1 (fr) * 2004-03-03 2006-05-19 Seb Sa Capteur de poids
DE102005028906A1 (de) * 2005-06-22 2006-12-28 Giesecke & Devrient Gmbh Vorrichtung für die Prüfung von Banknoten
GB0620944D0 (en) * 2006-10-20 2006-11-29 Insensys Ltd Curvature measurement moving relative to pipe
US20080203137A1 (en) * 2007-02-28 2008-08-28 International Business Machines Corporation Substrate bonding methods and system including monitoring
DE102007012157A1 (de) * 2007-03-12 2008-09-18 Brosa Ag Modular aufgebaute Messachse
DE102008013203A1 (de) * 2008-03-08 2009-09-17 Terex-Demag Gmbh Ausleger zur endseitigen Aufnahme von Lasten, Ausleger-Baugruppe mit mindestens zwei derartigen Auslegern sowie Verfahren zur Herstellung eines derartigen Auslegers
JP5487672B2 (ja) * 2009-03-27 2014-05-07 パナソニック株式会社 物理量センサ
US8943896B2 (en) * 2012-10-10 2015-02-03 Auto Industrial Co., Ltd. Pressure transducer using ceramic diaphragm
ITGE20130091A1 (it) * 2013-09-18 2015-03-19 Realte Di Giovanni Landro Sistema di cambio elettronico e di controllo di velocità e di trazione per motocicli
US10225629B2 (en) * 2013-11-25 2019-03-05 Chi Hung Louis Lam System for monitoring condition of adjustable construction temporary supports
JP6488698B2 (ja) * 2014-12-25 2019-03-27 ヤマハ株式会社 外力検出アレイモジュール
WO2016159245A1 (ja) * 2015-03-31 2016-10-06 株式会社ＮｅｊｉＬａｗ 通電路付部材及び通電路のパターニング方法、部材変化計測方法
EP3431948A1 (de) * 2017-07-17 2019-01-23 Planet GDZ AG Teststreifen für dichtungen
JP6820817B2 (ja) * 2017-10-03 2021-01-27 アズビル株式会社 トルク検出装置
JP7034811B2 (ja) * 2018-04-09 2022-03-14 日本電産コパル電子株式会社 歪センサの固定装置とそれを用いたトルクセンサ
JP7191737B2 (ja) * 2019-03-11 2022-12-19 日本電産コパル電子株式会社 ロードセル
JP7203645B2 (ja) * 2019-03-11 2023-01-13 日本電産コパル電子株式会社 ロードセル
WO2021070665A1 (ja) * 2019-10-09 2021-04-15 日本電産コパル電子株式会社 歪センサの固定装置とそれを用いたトルクセンサ
JP7321872B2 (ja) * 2019-10-09 2023-08-07 ニデックコンポーネンツ株式会社 歪センサの固定装置とそれを用いたトルクセンサ
JP7350606B2 (ja) * 2019-10-09 2023-09-26 ニデックコンポーネンツ株式会社 歪センサの固定装置とそれを用いたトルクセンサ
CN114364941A (zh) * 2019-10-09 2022-04-15 日本电产科宝电子株式会社 应变传感器的固定装置和使用该固定装置的扭矩传感器
JP7321871B2 (ja) * 2019-10-09 2023-08-07 ニデックコンポーネンツ株式会社 歪センサの固定装置とそれを用いたトルクセンサ
JP7350605B2 (ja) * 2019-10-09 2023-09-26 ニデックコンポーネンツ株式会社 歪センサの固定装置とそれを用いたトルクセンサ
CN112484624B (zh) * 2020-10-22 2022-08-09 浙江航鑫支吊架有限公司 一种基于物联网的抗震支吊架在线监测装置

Family Cites Families (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2599578A (en) * 1950-11-17 1952-06-10 Obert Leonard Device for measuring the change of strain in a solid medium
US2626338A (en) * 1952-05-08 1953-01-20 Trans Sonics Inc Measuring device
US2722587A (en) * 1953-03-20 1955-11-01 Lockheed Aircraft Corp Electric strain sensing device
US2982127A (en) * 1957-06-07 1961-05-02 George F Cummings Jr Strain gage
US3303450A (en) * 1964-10-06 1967-02-07 Blh Electronics Symmetrical dual-grid strain gaging
US3327270A (en) * 1965-01-06 1967-06-20 Pneumo Dynamics Corp Semi-conductor sensing assembly
US3411348A (en) * 1966-06-30 1968-11-19 W C Dillon & Company Inc Electronic dynamometer
US3479739A (en) * 1967-04-24 1969-11-25 Statham Instrument Inc Method of making a transducer beam
DE1798053A1 (de) * 1967-08-18 1971-09-09 Automation Ind Inc Elektrisches Widerstandsdehnungsmesselement und Verfahren zu dessen Herstellung
DE1950836B2 (de) * 1969-10-09 1973-03-08 Pietzsch, Ludwig, Dr Ing , 7500 Karlsruhe Dehnungsmessanordnung
US3695096A (en) * 1970-04-20 1972-10-03 Ali Umit Kutsay Strain detecting load cell
US3738162A (en) * 1971-09-10 1973-06-12 Us Army Fatigue damage indicator
US3899695A (en) * 1973-09-24 1975-08-12 Nat Semiconductor Corp Semiconductor pressure transducer employing novel temperature compensation means
US4055078A (en) * 1976-07-01 1977-10-25 Antonio Nicholas F D Strain transducer
US4104605A (en) * 1976-09-15 1978-08-01 General Electric Company Thin film strain gauge and method of fabrication
DE2810782A1 (de) * 1978-03-13 1979-09-20 Kloeckner Humboldt Deutz Ag Messeinrichtung fuer elastische verformungen
DE2842190C2 (de) * 1978-09-28 1985-01-24 Robert Bosch Gmbh, 7000 Stuttgart Dehnmeßstreifen in Dickschichttechnik
US4311980A (en) * 1978-10-12 1982-01-19 Fabrica Italiana Magneti Marelli, S.P.A. Device for pressure measurement using a resistor strain gauge
JPS55118109U (US07943777-20110517-C00090.png) * 1979-02-16 1980-08-21
JPS55140112A (en) * 1979-04-19 1980-11-01 Tokyo Electric Co Ltd Weighing device employing load cell
US4322980A (en) * 1979-11-08 1982-04-06 Hitachi, Ltd. Semiconductor pressure sensor having plural pressure sensitive diaphragms and method
JPS56140203A (en) * 1980-04-02 1981-11-02 Toyota Central Res & Dev Lab Inc Bridge circuit
FR2502327A1 (fr) * 1981-03-20 1982-09-24 Dal Dan Felice Procede de realisation de capteurs a jauge de contrainte
GB2098739B (en) * 1981-05-16 1985-01-16 Colvern Ltd Electrical strain gauges
US4424717A (en) * 1981-10-08 1984-01-10 The Babcock & Wilcox Company Force transducer
JPS58150816A (ja) * 1982-03-04 1983-09-07 Kyowa Dengiyou:Kk ひずみ検出器
US4481497A (en) * 1982-10-27 1984-11-06 Kulite Semiconductor Products, Inc. Transducer structures employing ceramic substrates and diaphragms
JPS59190603A (ja) * 1983-04-13 1984-10-29 Hitachi Ltd ひずみゲ−ジ
GB2141548A (en) * 1983-06-16 1984-12-19 Welwyn Electronics Ltd Strain-gauge transducer
US4586018A (en) * 1983-09-19 1986-04-29 Ford Motor Company Combustion pressure sensor
GB8332527D0 (en) * 1983-12-06 1984-01-11 Barnett J D Strain transducers
US4553872A (en) * 1984-02-15 1985-11-19 Fmc Corporation Load cell clamping apparatus
DE3429649A1 (de) * 1984-08-11 1986-02-20 Vdo Adolf Schindling Ag, 6000 Frankfurt Elektrischer widerstand

Also Published As

Publication number Publication date
DE3631647A1 (de) 1987-03-26
IT8553804V0 (it) 1985-09-17
ES2003115A6 (es) 1988-10-16
FR2587484B1 (fr) 1992-02-14
JPS6267206U (US07943777-20110517-C00090.png) 1987-04-27
FR2587484A1 (fr) 1987-03-20
JP2514502Y2 (ja) 1996-10-23
NL8602362A (nl) 1987-04-16
CH669994A5 (en) 1989-04-28
DE3631647C2 (de) 1996-09-12
US4793189A (en) 1988-12-27
PT83393B (pt) 1993-01-29
IT206727Z2 (it) 1987-10-01
GB2184239B (en) 1990-05-09
GB8622354D0 (en) 1986-10-22
PT83393A (en) 1986-10-01
GB2184239A (en) 1987-06-17

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Legal Events

Date Code Title Description
RE Patent lapsed

Owner name: MARELLI AUTRONICA S.P.A.

Effective date: 19990930