JPH0695052B2 - Electromagnetic stress measurement device that is not affected by lift-off - Google Patents
Electromagnetic stress measurement device that is not affected by lift-offInfo
- Publication number
- JPH0695052B2 JPH0695052B2 JP60261303A JP26130385A JPH0695052B2 JP H0695052 B2 JPH0695052 B2 JP H0695052B2 JP 60261303 A JP60261303 A JP 60261303A JP 26130385 A JP26130385 A JP 26130385A JP H0695052 B2 JPH0695052 B2 JP H0695052B2
- Authority
- JP
- Japan
- Prior art keywords
- lift
- coil
- magnetic
- detecting
- output
- 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 - Fee Related
Links
- 238000005259 measurement Methods 0.000 title claims description 11
- 238000001514 detection method Methods 0.000 claims description 15
- 230000005284 excitation Effects 0.000 claims description 6
- 230000001360 synchronised effect Effects 0.000 claims description 5
- 230000000694 effects Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 210000003371 toe Anatomy 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は鉄鋼製の構造物ならびに機械部品の残留応力お
よび応力を塗料等の被覆物もしくは錆等の有無にかかわ
らず非破壊的に測定する方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention non-destructively measures residual stress and stress of steel structures and mechanical parts regardless of the presence of coating such as paint or rust. It is about the method.
従来この種の測定法においては測定値がリフト・オフに
大きく左右されるため、測定対象表面の塗料、被覆物、
錆等を取り除いて残留応力および応力を測定する不完全
な非破壊測定法であった。これを解決するために同一出
願人によって、１つのセンサでリフト・オフの大きさを
測定してセンサ出力を補正する方法が提案された（「非
破壊検査」vol.33No..9A,1984年）。この方法は同一箇
所をリフト・オフをわずか変えて２回測定し換算するも
ので、労力を要し、実用上不便であるという欠点があっ
た。Conventionally, in this type of measurement method, the measured value is greatly affected by lift-off, so the paint, coating,
It was an incomplete non-destructive measurement method that measures residual stress and stress by removing rust. To solve this, the same applicant proposed a method of measuring the lift-off magnitude with one sensor and correcting the sensor output (“Non-destructive inspection” vol.33 No.9A, 1984). ). In this method, the same location is measured twice by changing the lift-off slightly and converted, which is labor-intensive and disadvantageous in practical use.
本発明は上記欠点を一掃し、リフト・オフのいかんにか
かわらずセンサを測定対象に当てるだけで残留応力およ
び応力測定が瞬時に行える装置を提供するものである。The present invention eliminates the above-mentioned drawbacks and provides an apparatus capable of instantaneously measuring residual stress and stress simply by applying a sensor to a measurement object regardless of lift-off.
本発明は励磁用コイル及びリフト・オフ（δ）検出用コ
イルが巻かれたコの字型磁芯と応力（σ）によって生じ
る磁位差を検出するための磁位差検出用コイルが巻かれ
たコの字型磁芯を直交させた構成からなる磁気異方性セ
ンサ と、前記励磁用コイルに定電流を供給する発振器
と、前記磁位差検出用コイルの出力電圧を増幅器を介し
て前記発振器の信号と同期して整流を行う同期整流器
と、前記リフト・オフ（δ）検出用コイルの出力を増幅
器を介して整流を行う整流器と、前記同期整流器の出力
電圧をV1（δ，σ）、前記整流器の出力電圧をV
2（δ）、測定対象の無い場合の前記整流器の出力電圧
をV2（∞）としての出力比V1（δ，σ）／〔V2（δ）−
V2（∞）〕を演算する演算器と、前記演算器の出力を表
示する表示器とから構成され、前記磁位差検出用コイル
が巻かれたコの字型磁芯の先端を前記励磁用コイル及び
リフト・オフ（δ）検出用コイルが巻かれたコの字型磁
芯先端に対し、リフト・オフが大きくなる方へ調節する
ことにより前記磁位差検出用コイルの出力と前記リフト
・オフ（δ）検出用コイルの出力のリフト・オフ特性を
一致させ、リフト・オフ（δ）の影響を消去することを
特徴とする。The present invention is provided with a U-shaped magnetic core around which an exciting coil and a lift-off (δ) detecting coil are wound, and a magnetic difference detecting coil for detecting a magnetic difference caused by stress (σ). A magnetic anisotropy sensor having a configuration in which U-shaped magnetic cores are orthogonalized, an oscillator for supplying a constant current to the exciting coil, and an output voltage of the magnetic difference detecting coil via an amplifier. A synchronous rectifier that performs rectification in synchronization with the signal of the oscillator, a rectifier that rectifies the output of the lift-off (δ) detection coil through an amplifier, and an output voltage of the synchronous rectifier is V 1 (δ, σ ), The output voltage of the rectifier is V
2 (δ), the output voltage of the rectifier when there is no measurement target is V 2 (∞), and the output ratio V 1 (δ, σ) / [V 2 (δ)-
V 2 (∞)] and a display for displaying the output of the calculator. The tip of the U-shaped magnetic core around which the coil for detecting the magnetic difference is wound Of the magnetic difference detection coil and the lift by adjusting the lift-off (δ) detection coil around the tip of the U-shaped magnetic core A feature is that the lift-off characteristics of the output of the off (δ) detection coil are made to coincide with each other to eliminate the influence of the lift-off (δ).
〔実施例〕 以下、本発明の実施例を図に従って具体的に説明する。[Examples] Examples of the present invention will be specifically described below with reference to the drawings.
第１図はセンサの構造を示すもので、１は励磁用磁芯、
２は応力によって生じる磁位差検出用磁芯、３はスペー
サ、４は励磁用コイル、５は応力によって生じる磁位差
検出用コイル、６はリフト・オフ検出用コイルであり、
ａは磁芯２の足先と磁芯１の足先とのリフト・オフの差
であり、ａを調節して応力によって生じる磁位差検出用
コイル５の出力とリフト・オフ検出用コイル６の出力と
のリフト・オフ特性を一致させることができる。FIG. 1 shows the structure of the sensor, where 1 is an exciting magnetic core,
2 is a magnetic core for detecting a magnetic difference caused by stress, 3 is a spacer, 4 is a coil for exciting, 5 is a coil for detecting magnetic difference caused by a stress, 6 is a lift-off detecting coil,
a is a lift-off difference between the toes of the magnetic core 2 and the toes of the magnetic core 1, and the output of the magnetic-difference detecting coil 5 and the lift-off detecting coil 6 caused by stress by adjusting a. It is possible to match the lift-off characteristic with the output of.
第３図は測定装置のブロック図で、発振器７から定電流
がセンサ８の励磁用コイル44に供給される。センサ８の
応力による磁位差検出用コイル５に発生した電圧は増幅
器９を経て同期整流器11に至り、発振器７の信号と同期
させて整流する。ここで得られた電圧をV1（δ，σ）と
する。ただしσは応力、δは磁芯１の足先から測定対象
金属までの距離でリフト・オフと称されるものである。FIG. 3 is a block diagram of the measuring apparatus. A constant current is supplied from the oscillator 7 to the exciting coil 44 of the sensor 8. The voltage generated in the magnetic potential difference detection coil 5 due to the stress of the sensor 8 reaches the synchronous rectifier 11 via the amplifier 9 and is rectified in synchronization with the signal of the oscillator 7. The voltage obtained here is V 1 (δ, σ). Here, σ is the stress, and δ is the distance from the toe of the magnetic core 1 to the metal to be measured, which is called lift-off.
他方、センサ８のリフト・オフ検出用コイル６に発生し
た電圧は増幅器10を経て整流器12に至る。ここで得られ
た電圧をV2（δ）とする。演算器13においては、測定対
象の無い場合のV2（δ）を一定V2（∞）と表わせば、出
力比V1（δ，σ）／〔V2（δ）−V2（∞）〕の演算が電
気回路上で実行され、表示器14にその出力比が表示され
る。On the other hand, the voltage generated in the lift-off detection coil 6 of the sensor 8 reaches the rectifier 12 via the amplifier 10. The voltage obtained here is V 2 (δ). In the calculator 13, if V 2 (δ) when there is no measurement target is expressed as a constant V 2 (∞), the output ratio V 1 (δ, σ) / [V 2 (δ) -V 2 (∞) ] Is executed on the electric circuit, and the output ratio is displayed on the display unit 14.
ここで第３図に示すような簡単な磁気回路のモデルで原
理を説明する。励磁用磁芯１を通る磁束をΦ１（δ）、
磁芯１、２の断面積をＳ（空気中の磁路の断面積も簡単
のためにＳとする）、測定対象の磁路の有効断面積を
Ｓ′、磁芯１、２の足間距離をｌ、励磁用磁芯１の高さ
をh1、磁位差検出用磁芯２の高さをh2、測定対象に応力
σが作用することによって生じる磁位差を△Φ（σ）、
励磁用コイル４の巻き数をN1、磁位差検出用コイル５の
巻き数をN2、リフト・オフ検出用コイル６の巻き数を
N3、励磁電流をＩ、角周波数をω、磁芯の透磁率をμ、
測定対象の透磁率をμ′、空気中の透磁率をμ０とすれ
ば、出力電圧は と表わされる。ここで ｃ＝（2h2＋ｌ）μ0/2μ Ｂ＝ωN1N3ISμ0/2 ｂ＝（2h1＋ｌ）μ0/2μ＋ｌμ0S/2μ′Ｓ′ とおけば、式（１）、式（３）は と表わされる。ｂ＞ｃであるから、第１図におけるａを
調節すればｂ＝ａ＋ｃとすることができ、式（４）は となる。受際には以上の簡単なモデルに補正が必要とな
り、ｋをセンサ並びに装置によって決まる補正定数とす
れば となる。従って、ａを調節することによってka＋ｃ＝ｂ
とすることができ、式（６）を式（５）で除せば となり、リフト・オフδが消去される。これにより出力
比V1（δ，σ）／〔V2（δ）−V2（∞）〕はリフト・オ
フδに依存せず、応力σのみの関数となる。Here, the principle will be described using a simple magnetic circuit model as shown in FIG. The magnetic flux passing through the magnetic core 1 for excitation is Φ 1 (δ),
The cross-sectional area of the magnetic cores 1 and 2 is S (the cross-sectional area of the magnetic path in the air is also S for simplicity), the effective cross-sectional area of the magnetic path to be measured is S ′, and the space between the magnetic cores 1 and 2 is between the legs. The distance is 1, the height of the magnetic core 1 for excitation is h 1 , the height of the magnetic core 2 for detecting the magnetic potential difference is h 2 , and the magnetic potential difference caused by the stress σ acting on the measurement target is ΔΦ (σ ),
The number of turns of the excitation coil 4 is N 1 , the number of turns of the magnetic difference detection coil 5 is N 2 , and the number of turns of the lift-off detection coil 6 is
N 3 , exciting current I, angular frequency ω, magnetic permeability of the core μ,
If the permeability of the object to be measured is μ ′ and the permeability in air is μ 0 , the output voltage is Is represented. here c = The put the (2h 2 + l) μ 0 / 2μ B = ωN 1 N 3 ISμ 0/2 b = (2h 1 + l) μ 0 / 2μ + lμ 0 S / 2μ'S ', equation (1), the formula ( 3) is Is represented. Since b> c, it is possible to obtain b = a + c by adjusting a in FIG. Becomes When receiving, it is necessary to correct the above simple model. If k is a correction constant determined by the sensor and the device, Becomes Therefore, by adjusting a, ka + c = b
Can be obtained by dividing equation (6) by equation (5) And the lift-off δ is erased. As a result, the output ratio V 1 (δ, σ) / [V 2 (δ) -V 2 (∞)] does not depend on the lift-off δ and becomes a function of only the stress σ.
次に実際の測定例を示す。Next, an actual measurement example is shown.
図１におけるセンサの磁芯１、２を積層けい素鋼板でも
って足中心間距離ｌを10.9mmの大きさに作成した。構造
用の炭素鋼についてはｂ−ｃ＝0.05mmであったので、図
１のａを調節し、0.17mmとすることによってka＝ｂ−ｃ
とすることができた。このセンサを用いて、周波数100H
zでリフト・オフを変えてSS41材の応力測定を実施した
結果を第４図に示す。出力比はリフト・オフに依存せず
応力のみの関数となることが実証された。The magnetic cores 1 and 2 of the sensor shown in FIG. 1 were made with a laminated silicon steel plate to have a center-to-foot distance 1 of 10.9 mm. Since b−c = 0.05 mm for the structural carbon steel, ka = b−c was set by adjusting a in FIG. 1 to 0.17 mm.
I was able to With this sensor, frequency 100H
Fig. 4 shows the result of stress measurement of SS41 material with different lift-off at z. It was demonstrated that the power ratio does not depend on lift-off and is a function of stress only.
本発明にかかるリフト・オフの影響を受けない電磁式応
力測定装置は、上述のように、センサの磁芯２のａの調
節とコイル６によるリフト・オフの検出並びに演算器13
よってリフト・オフの影響が消去されるから、センサを
測定対象に当てるだけでリフト・オフに無関係に瞬時に
残留応力及び応力の測定を行うことができる。As described above, the electromagnetic stress measuring apparatus according to the present invention which is not affected by lift-off is, as described above, the adjustment of a of the magnetic core 2 of the sensor, the detection of lift-off by the coil 6, and the calculator 13
Therefore, the effect of lift-off is eliminated, and residual stress and stress can be instantaneously measured regardless of lift-off simply by applying the sensor to the measurement target.
第１図は本発明によるセンサの構成図、第２図は本発明
の測定回路のブロック図、第３図は本発明の磁気回路を
説明する図、第４図は本発明の装置による実測例を示す
図である。なお、１……励磁用磁芯、２……磁位差検出
用磁芯、４……励磁用コイル、、５……磁位差検出用コ
イル、６……リフト・オフ検出用コイル、13……演算
器。FIG. 1 is a block diagram of a sensor according to the present invention, FIG. 2 is a block diagram of a measuring circuit according to the present invention, FIG. 3 is a diagram for explaining a magnetic circuit according to the present invention, and FIG. 4 is an example of measurement by a device according to the present invention. FIG. In addition, 1 ... Excitation magnetic core, 2 ... Magnetic difference detection magnetic core, 4 ... Excitation coil, 5 ... Magnetic difference detection coil, 6 ... Lift-off detection coil, 13 ...... Calculator.
Claims (1)
用コイルが巻かれたコの字型磁芯と応力（σ）によって
生じる磁位差を検出するための磁位差検出用コイルが巻
かれたコの字型磁芯を直交させた構成からなる磁気異方
性センサと、前記励磁用コイルに定電流を供給する発振
器と前記磁位差検出用コイルの出力電圧を増幅器を介し
て前記発振器の信号と同期して整流を行う同期整流器
と、前記リフト・オフ（δ）検出用コイルの出力を増幅
器を介して整流を行う整流器と、前記同期整流器の出力
電圧をV1（δ，σ）、前記整流器の出力電圧V2（δ）、
測定対象の無い場合の前記整流器の出力電圧をV2（∞）
としての出力比V1（δ，σ）／〔V2（δ）−V2（∞）〕
を演算する演算器と、前記演算器の出力を表示する表示
器とから構成され、前記磁位差検出用コイルの出力と前
記リフト・オフ（δ）検出用コイルの出力のリフト・オ
フ特性を一致させ、リフト・オフ（δ）の影響を消去す
るために、前記磁位差検出用コイルが巻かれたコの字型
磁芯の先端を前記励磁用コイル及びリフト・オフ（δ）
検出用コイルが巻かれたコの字型磁芯の先端に対し、リ
フト・オフが大きくなる方へ調節されていることを特徴
とするリフト・オフの影響を受けない電磁式応力測定装
置。1. A U-shaped magnetic core around which an exciting coil and a lift-off (δ) detecting coil are wound, and a magnetic difference detecting coil for detecting a magnetic difference caused by stress (σ). A magnetic anisotropy sensor having a configuration in which wound U-shaped magnetic cores are orthogonal to each other, an oscillator for supplying a constant current to the excitation coil, and an output voltage of the magnetic difference detection coil through an amplifier. A synchronous rectifier that rectifies in synchronization with the signal of the oscillator, a rectifier that rectifies the output of the lift-off (δ) detection coil through an amplifier, and an output voltage of the synchronous rectifier is V 1 (δ, σ), the output voltage V 2 (δ) of the rectifier,
The output voltage of the rectifier when there is no measurement target is V 2 (∞)
Output ratio V 1 (δ, σ) / [V 2 (δ) -V 2 (∞)]
Of the lift-off characteristic of the output of the coil for detecting the magnetic difference and the output of the coil for detecting the lift-off (δ). In order to match and eliminate the effect of lift-off (δ), the tip of the U-shaped magnetic core around which the magnetic-position difference detecting coil is wound is attached to the exciting coil and lift-off (δ).
An electromagnetic stress measurement device that is not affected by lift-off, characterized in that the tip of a U-shaped magnetic core around which a detection coil is wound is adjusted so that the lift-off increases.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60261303A JPH0695052B2 (en) | 1985-11-22 | 1985-11-22 | Electromagnetic stress measurement device that is not affected by lift-off |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60261303A JPH0695052B2 (en) | 1985-11-22 | 1985-11-22 | Electromagnetic stress measurement device that is not affected by lift-off |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62121325A JPS62121325A (en) | 1987-06-02 |
| JPH0695052B2 true JPH0695052B2 (en) | 1994-11-24 |
Family
ID=17359920
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60261303A Expired - Fee Related JPH0695052B2 (en) | 1985-11-22 | 1985-11-22 | Electromagnetic stress measurement device that is not affected by lift-off |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0695052B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01135339U (en) * | 1988-03-04 | 1989-09-18 | ||
| JPH01137440U (en) * | 1988-03-16 | 1989-09-20 | ||
| JPH02296122A (en) * | 1989-05-10 | 1990-12-06 | Komatsu Ltd | Stress measuring method using magnetostruction type stress sensor |
| JPH0429848U (en) * | 1990-07-02 | 1992-03-10 | ||
| JP4746782B2 (en) * | 2001-07-10 | 2011-08-10 | 中電技術コンサルタント株式会社 | Stress measuring method and stress measuring apparatus |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5723203B2 (en) * | 1974-06-26 | 1982-05-18 |
-
1985
- 1985-11-22 JP JP60261303A patent/JPH0695052B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62121325A (en) | 1987-06-02 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |