JP6352321B2 - Non-contact stress measuring method and measuring apparatus by composite resonance method - Google Patents
Non-contact stress measuring method and measuring apparatus by composite resonance method Download PDFInfo
- Publication number
- JP6352321B2 JP6352321B2 JP2016015950A JP2016015950A JP6352321B2 JP 6352321 B2 JP6352321 B2 JP 6352321B2 JP 2016015950 A JP2016015950 A JP 2016015950A JP 2016015950 A JP2016015950 A JP 2016015950A JP 6352321 B2 JP6352321 B2 JP 6352321B2
- Authority
- JP
- Japan
- Prior art keywords
- wire
- coil
- stress
- feedback
- amplifier
- 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.)
- Active
Links
Landscapes
- Force Measurement Appropriate To Specific Purposes (AREA)
Description
本発明は、応力が作用するＰＣワイヤー等の線材について、その応力変化に伴う磁気特性の微小変化を大きな変化値として検出することができる複合共振法による非接触応力測定方法及びその測定装置に関する。 The present invention relates to a non-contact stress measurement method by a composite resonance method and a measurement apparatus thereof capable of detecting a minute change in magnetic characteristics accompanying a change in stress of a wire such as a PC wire on which stress is applied.
ＰＣワイヤーは、ＰＣ鋼線、プレストレストコンクリートワイヤー（Ｐｒｅｓｔｒｅｓｓｅｄ Ｃｏｎｃｒｅｔｅ Ｗｉｒｅ)と称され、コンクリートの弱点を補い強度を高めるため、橋梁から建築物まで様々な分野で使用されている。このＰＣワイヤーは、大きな引張強さを有し、破断時の伸びが大きい緊張材である。このように構造物に用いられているＰＣワイヤー等の線材は、その腐食その他の原因で引張強度等が低下することがある。そこで、ＰＣワイヤー等の線材の張力を計測することにより、橋梁、建築物等の構造物の安全性の向上を図っている。 PC wires are called PC steel wires and prestressed concrete wires, and are used in various fields from bridges to buildings in order to compensate for the weak points of concrete and increase the strength. This PC wire is a tendon having a large tensile strength and a large elongation at break. As described above, the tensile strength or the like of a wire such as a PC wire used in a structure may be reduced due to corrosion or other causes. Then, the safety | security of structures, such as a bridge and a building, is improved by measuring the tension | tensile_strength of wire materials, such as PC wire.
ＰＣワイヤー等の線材は、これを健全に機能することで橋梁や建築物等の安全が確保される。特に耐荷性能に関わる重要な部材である。このようなＰＣワイヤー等の線材の変状が顕在化すると、確実な施工管理と維持管理ができなくなる。そこで、このＰＣワイヤー等の線材に作用する張力を計測する必要がある。例えば、施工の際に緊張管理、供用開始時に初期状態を確認する必要がある。次に供用中、点検時に経時変化を確認する必要がある。 Wires such as PC wires function safely to ensure safety of bridges and buildings. It is an important member especially related to load bearing performance. When such deformation of the wire material such as PC wire becomes obvious, it becomes impossible to perform reliable construction management and maintenance management. Therefore, it is necessary to measure the tension acting on the wire such as the PC wire. For example, it is necessary to check the initial state at the time of start of tension management and operation during construction. Next, during operation, it is necessary to check changes over time at the time of inspection.
ＰＣワイヤー等の線材に作用する張力を計測する代表的な計測方法としては、次に説明する「ひずみゲージを用いる計測方法」と「ロードセルを用いる計測方法」の２つの方法が挙げられる。
ひずみゲージを用いる計測方法は、ひずみゲージを線材（鋼材）に貼付してひずみ値を計測し、そのひずみ値にヤング係数と断面積を乗ずることで張力を計測する方法である。この計測方法は、ひずみゲージという精度の高い計測器を用いることで、張力の計測精度が非常に高くなる方法である。しかし、ひずみゲージを貼付するためには線材（鋼材）の表面を微小ではあるが削る必要があり、また既存の鋼材に対してはひずみゲージ貼付時からの増分張力のみしか計測できなかった。
As a typical measuring method for measuring the tension acting on a wire such as a PC wire, there are two methods of “measuring method using strain gauge” and “measuring method using load cell” described below.
The measurement method using a strain gauge is a method of measuring a tension value by attaching a strain gauge to a wire (steel material), measuring the strain value, and multiplying the strain value by a Young's modulus and a cross-sectional area. This measurement method is a method in which the measurement accuracy of tension becomes very high by using a high-precision measuring instrument called a strain gauge. However, in order to attach the strain gauge, the surface of the wire material (steel material) needs to be cut even though it is minute, and for the existing steel material, only the incremental tension from the time when the strain gauge was applied could be measured.
ロードセルを用いる計測方法は、ロードセル（圧縮型荷重計測器）を線材（鋼材）の定着端部に介在させて張力を計測する方法である。この方法は上述のひずみゲージと同様に非常に高い計測精度を有しており、さらに線材（鋼材）の表面を削る必要がない利点を有している。しかし、ロードセルはセンターホール型の計測器であるため、線材（鋼材）の架設時に計測器を鋼材に挿通して設置する必要があり、既存の鋼材に対しては利用できなかった。その定着端部に計測器を介在させるため定着端が大きくなるという欠点を有している。 The measuring method using a load cell is a method of measuring a tension by inserting a load cell (compression load measuring instrument) at a fixing end of a wire (steel material). This method has very high measurement accuracy like the above-described strain gauge, and further has an advantage that the surface of the wire (steel) need not be cut. However, since the load cell is a center-hole type measuring instrument, it is necessary to insert the measuring instrument through the steel material when installing the wire (steel material), and it cannot be used for existing steel materials. Since the measuring device is interposed at the fixing end, there is a disadvantage that the fixing end becomes large.
これらのひずみゲージを用いる計測方法又はロードセルを用いる計測方法の欠点を解決する技術として、例えば特許文献１の特開２００３−２７００５９公報「鉄筋コンクリート構造物の鉄筋現有応力測定システム」のように、磁歪法と呼ばれる測定原理を利用して、磁性体の応力変化に伴う透磁率の変化を利用して応力を計測する装置が提案されている。この計測装置は、筒状の中空部材の内外にコイルを配置し、更に温度計を備えており、中空部に磁性体を挿通して計測を行う。計測原理は、外側コイル（１次コイル）にパルス電流を加え、内側コイル（２次コイル）で誘導電流値の変化を検出し、その誘導電流値と温度、透磁率、応力の関係式より応力を算定する構成である。 As a technique for solving the disadvantages of the measurement method using the strain gauge or the measurement method using the load cell, for example, as disclosed in Japanese Patent Application Laid-Open No. 2003-270059 “Reinforced Concrete Stress Reinforced Stress Measurement System” of Patent Document 1, a magnetostriction method is used. There has been proposed an apparatus for measuring stress using a change in magnetic permeability associated with a change in stress of a magnetic material by using a measurement principle called “stress”. This measuring device includes a coil disposed inside and outside a cylindrical hollow member, and further includes a thermometer, and performs measurement by inserting a magnetic material into the hollow portion. The measurement principle is that a pulse current is applied to the outer coil (primary coil), the change in the induced current value is detected by the inner coil (secondary coil), and the stress is calculated from the relational expression of the induced current value, temperature, permeability, and stress. It is the composition which calculates.
また、特許文献２の特開２００９−２６５００３公報「張力測定装置」のように、計測器は、飽和漸近磁化範囲まで直流磁化する円筒状の磁化器、円筒の内側に配置された磁気センサで構成され、中空部に磁性体を挿通して計測を行う張力測定装置が提案されている。この計測原理は、磁気センサで検出される空間磁界強度の変化を用いて張力を算定する構成である。 In addition, as disclosed in Japanese Patent Application Laid-Open No. 2009-265003 “Tension Measuring Device” of Patent Document 2, the measuring instrument is composed of a cylindrical magnetizer that performs direct current magnetization up to a saturation asymptotic magnetization range, and a magnetic sensor disposed inside the cylinder In addition, there has been proposed a tension measuring device that performs measurement by inserting a magnetic material into a hollow portion. This measurement principle is a configuration in which tension is calculated using a change in spatial magnetic field intensity detected by a magnetic sensor.
特許文献１の鉄筋コンクリート構造物の鉄筋現有応力測定システムは、線材（鋼材）の部分的な削りを回避すると共に任意位置での計測を可能とし、更に計測器を２つ割りにすることで既存の鋼材への適用を可能にしている。しかし、この特許文献１のシステムでは、応力変化に伴う磁性体の磁気特性の変化は非常に微小な変化であるので測定精度の向上に限界があるという問題を有していた。 The existing stress measurement system for reinforced concrete structures in Patent Document 1 avoids partial shaving of the wire (steel) and enables measurement at an arbitrary position, and further splits the measuring instrument into two. It can be applied to steel materials. However, the system disclosed in Patent Document 1 has a problem in that there is a limit to the improvement in measurement accuracy because the change in magnetic properties of the magnetic material accompanying the change in stress is a very small change.
また、特許文献２の張力測定装置は、直流磁化にすることで、交流磁化による渦電流の透磁率・導電率への影響を解決し、特により線構造への適用性を高めている。しかし、この特許文献２の装置でも応力変化に伴う磁性体の磁気特性の変化は非常に微小な変化であり測定精度の向上に限界があるという問題を有していた。 Moreover, the tension measuring device of Patent Document 2 uses DC magnetization to solve the influence of eddy currents on the magnetic permeability and conductivity due to AC magnetization, and more particularly improves the applicability to line structures. However, the apparatus of Patent Document 2 also has a problem that the change in the magnetic properties of the magnetic material accompanying the change in stress is a very small change, and there is a limit to the improvement in measurement accuracy.
本発明の発明者は、正帰還ループの中に並列共振回路及び直列共振回路で発振させることで、他の増幅手段を用いず、鋼材の応力変化の測定に用いることにより、張力等の応力が作用するワイヤー等の線材について、その磁性体の応力変化に伴う磁気特性の微小変化を直接大きな変化値として検出できることに着目した。 The inventor of the present invention uses a parallel resonance circuit and a series resonance circuit in a positive feedback loop to oscillate the stress such as tension by using it for measuring the stress change of the steel material without using other amplification means. We paid attention to the fact that a small change in the magnetic properties associated with the stress change of the magnetic material can be directly detected as a large change value for the wire such as a working wire.
本発明は、かかる問題点を解決するために創案されたものである。すなわち、本発明の目的は、線材の応力変化に伴う磁気特性の微小変化を大きな変化値として検出することで、その応力変化の測定精度を向上させることができる複合共振法による非接触応力測定方法及びその測定装置を提供することにある。 The present invention has been developed to solve such problems. That is, an object of the present invention is to detect a minute change in magnetic characteristics accompanying a stress change of a wire as a large change value, thereby improving the measurement accuracy of the stress change, and a non-contact stress measurement method by a composite resonance method And providing a measuring device thereof.
本発明の測定方法は、ワイヤー等の線材（ｗ）の応力変化に伴う磁気特性の変化を検出し、該線材（ｗ）の応力を測定する複合共振法による非接触応力測定方法であって、
直列共振周波数近傍になるコンデンサ（９）を介して一次コイル（励磁コイル）（１）で前記線材（ｗ）を励磁し、この励磁された該線材（ｗ）の磁気特性により、二次コイル（帰還コイル）（２）に電圧を誘起させ、
前記二次コイル（帰還コイル）（２）とコンデンサ（４）により並列共振回路（５）を形成し、この信号は正帰還（β）の減衰器（１２）を介して、適正な正帰還量を増幅器（６）に入力することで自励発振器として作動させ、
前記増幅器（６）の出力は、前記線材（ｗ）を励磁させ、同時にその出力の一部から負帰還（−β）の減衰器（１３）を介して該増幅器（６）の安定を図り、
前記二次コイル（帰還コイル）（２）の共振電圧値が一定になるよう発振ループを作動させ、このとき前記一次コイル（励磁コイル）（１）の両端電位は励磁電流に比例するので、この励磁電流のヒステリシス損による位相のずれを補正して、該線材（ｗ）の応力を測定する、ことを特徴とする。
前記線材（ｗ）の温度を測定することにより、その温度変動を用いて前記線材（ｗ）の応力測定値を補正することができる。
The measurement method of the present invention is a non-contact stress measurement method by a composite resonance method that detects a change in magnetic properties accompanying a stress change of a wire (w) such as a wire and measures the stress of the wire (w),
The wire (w) is excited by a primary coil (excitation coil) (1) through a capacitor (9) near the series resonance frequency, and the secondary coil ( A voltage is induced in the feedback coil) (2),
A parallel resonance circuit (5) is formed by the secondary coil (feedback coil) (2) and the capacitor (4), and this signal is passed through an attenuator (12) of positive feedback (β) to provide an appropriate positive feedback amount. Is input to the amplifier (6) to operate as a self-excited oscillator,
The output of the amplifier (6) excites the wire (w), and simultaneously stabilizes the amplifier (6) from a part of the output via the negative feedback (−β) attenuator (13),
The oscillation loop is operated so that the resonance voltage value of the secondary coil (feedback coil) (2) becomes constant. At this time, the potential at both ends of the primary coil (excitation coil) (1) is proportional to the excitation current. The stress of the wire (w) is measured by correcting the phase shift due to the hysteresis loss of the excitation current.
By measuring the temperature of the wire (w), the stress measurement value of the wire (w) can be corrected using the temperature fluctuation.
本発明の測定装置は、ワイヤー等の線材（ｗ）の応力変化に伴う磁気特性の変化を検出することにより、該線材（ｗ）の応力を測定する複合共振法による非接触応力測定装置であって、
前記線材（ｗ）を励磁する一次コイル（励磁コイル）（１）と、この励磁された線材（ｗ）の磁気特性により電圧が誘起される二次コイル（帰還コイル）（２）を内装した応力センサ部（３）と、
前記応力センサ部（３）の一次コイル（励磁コイル）（１）と二次コイル（帰還コイル）（２）間において、前記線材（ｗ）が有する磁気特性で磁気結合させる、該二次コイル（帰還コイル）（２）にコンデンサ（４）を並列に介して形成した並列共振回路（５）と、
前記二次コイル（帰還コイル）（２）側で生じる測定信号を増幅する増幅器（６）と、
前記増幅器（６）と前記一次コイル（励磁コイル）（１）の間に入れた、抵抗（８）及びコンデンサ（４）を介して形成される直列共振回路（７）と、を備え、
前記並列共振回路（５）の信号は正帰還（β）の減衰器（１２）を介して、適正な正帰還量を前記増幅器（６）に入力することで自励発振器として作動させ、
前記増幅器（６）の出力は、前記線材（ｗ）を励磁させ、同時にその出力の一部から負帰還（−β）の減衰器（１３）を介して該増幅器（６）の安定を図り、前記二次コイル（帰還コイル）（２）の共振電圧値が一定になるよう発振ループを作動させ、このとき前記一次コイル（励磁コイル）（１）の両端電位は励磁電流に比例するので、この励磁電流のヒステリシス損による位相のずれを補正して、該線材（ｗ）の応力を測定し得るように構成した、ことを特徴とする。
前記応力センサ部（３）は、前記線材（ｗ）を中心部に貫通させることができるように、該応力センサ部（３）を長手方向に分割し、これを着脱自在に接合し得る構造にすることができる。
前記線材（ｗ）の温度の変化値を用いて該線材（ｗ）の測定値を補正するために、該線材（ｗ）の温度変化を測定する温度センサ（３１）を設けることが好ましい。
The measuring device of the present invention is a non-contact stress measuring device based on a composite resonance method that measures the stress of the wire (w) by detecting a change in magnetic properties accompanying the stress change of the wire (w) such as a wire. And
Stresses in which a primary coil (excitation coil) (1) for exciting the wire (w) and a secondary coil (feedback coil) (2) in which a voltage is induced by the magnetic characteristics of the excited wire (w) are provided. A sensor unit (3);
Between the primary coil (excitation coil) (1) and the secondary coil (feedback coil) (2) of the stress sensor part (3), the secondary coil (2) that is magnetically coupled with the magnetic properties of the wire (w) ( A parallel resonant circuit (5) formed by connecting a capacitor (4) in parallel to the feedback coil) (2);
An amplifier (6) for amplifying a measurement signal generated on the secondary coil (feedback coil) (2) side;
A series resonant circuit (7) formed between the amplifier (6) and the primary coil (excitation coil) (1) and formed through a resistor (8) and a capacitor (4),
The signal of the parallel resonant circuit (5) is operated as a self-excited oscillator by inputting an appropriate positive feedback amount to the amplifier (6) via an attenuator (12) of positive feedback (β),
The output of the amplifier (6) excites the wire (w), and simultaneously stabilizes the amplifier (6) from a part of the output via the negative feedback (−β) attenuator (13), The oscillation loop is operated so that the resonance voltage value of the secondary coil (feedback coil) (2) becomes constant. At this time, the potential at both ends of the primary coil (excitation coil) (1) is proportional to the excitation current. A feature is that the phase shift due to the hysteresis loss of the excitation current is corrected and the stress of the wire (w) can be measured.
The stress sensor part (3) has a structure in which the stress sensor part (3) is divided in the longitudinal direction so that the wire (w) can penetrate through the central part and can be detachably joined. can do.
In order to correct the measured value of the wire (w) using the change value of the temperature of the wire (w), it is preferable to provide a temperature sensor (31) for measuring the temperature change of the wire (w).
本発明の測定方法では、張力により微小に変化する線材（ｗ）のヒステリシス損失成分について、一次コイル（励磁コイル）（１）の両端差電圧を所定の信号として検出することができる。本発明は他の増幅手段を必要とせず再現性の高い信号が得られるので、線材（ｗ）の応力変化に伴う磁性体の磁気特性の微小な変化について、大きな変化値として検出することができ、その測定精度を向上させることができる。
また、増幅の出力に抵抗（８）及びコンデンサ（４）による励磁電流の直列共振回路（７）により、ヒステリシス損など損失による位相のずれを補正することで、更に正確に測定することができる。
線材（ｗ）の応力測定値は、温度の変動にともない特定の係数をもって比例するため、簡単な一次式をもって線材（ｗ）の応力測定値を補正することができる。
In the measurement method of the present invention, the voltage difference between both ends of the primary coil (excitation coil) (1) can be detected as a predetermined signal with respect to the hysteresis loss component of the wire (w) that slightly changes due to the tension. Since the present invention does not require any other amplifying means and can obtain a highly reproducible signal, it is possible to detect a minute change in the magnetic properties of the magnetic material accompanying a change in the stress of the wire (w) as a large change value. The measurement accuracy can be improved.
Further, by correcting the phase shift due to loss such as hysteresis loss by the series resonance circuit (7) of the exciting current by the resistor (8) and the capacitor (4) at the output of amplification, it can be measured more accurately.
Since the stress measurement value of the wire (w) is proportional with a specific coefficient as the temperature varies, the stress measurement value of the wire (w) can be corrected with a simple linear equation.
本発明の測定装置では、複雑な回路を用いず、張力により微小に変化する線材（ｗ）のヒステリシス損失成分について、一次コイル（励磁コイル）（１）の両端差電圧を所定の信号として検出することができる。本発明は再現性の高い信号が得られるので、応力変化に伴う磁性体の磁気特性の微小な変化についてその測定精度を向上させることができる。
また、簡単な装置であるために、コスト面から応力センサ部（３）のみを、多数ある既存のワイヤー等の線材（ｗ）それぞれに予め装着しておくことが可能になる。
In the measuring apparatus of the present invention, the differential voltage across the primary coil (excitation coil) (1) is detected as a predetermined signal for the hysteresis loss component of the wire (w) that changes minutely due to tension without using a complicated circuit. be able to. Since a highly reproducible signal can be obtained according to the present invention, the measurement accuracy can be improved for a minute change in the magnetic properties of the magnetic material accompanying a change in stress.
In addition, since it is a simple device, only the stress sensor unit (3) can be attached in advance to each of a number of existing wires (w) such as wires in terms of cost.
本発明は、ＰＣワイヤー等の線材の応力変化に伴う磁気特性の微小変化を大きな変化値として検出することで、その測定精度を向上させることができる複合共振法による非接触応力測定方法である。 The present invention is a non-contact stress measurement method by a complex resonance method that can improve the measurement accuracy by detecting a minute change in magnetic properties accompanying a stress change of a wire such as a PC wire as a large change value.
以下、本発明の実施の形態を図面を参照して説明する。
＜複合共振法による非接触応力測定装置の構成＞
図１は実施例１の複合共振法による非接触応力測定装置を示す概略構成図である。図２は応力センサ部をＰＣワイヤーに装着した状態を示す拡大正面図である。
本発明の非接触応力測定装置は、ＰＣワイヤー等の線材ｗを励磁する一次コイル（励磁コイル）１と、この励磁された線材ｗの出力を帰還させる二次コイル（帰還コイル）２を内装した応力センサ部３と、この応力センサ部３の一次コイル（励磁コイル）１と二次コイル（帰還コイル）２間において、線材ｗが有する磁気特性で磁気結合させる、二次コイル（帰還コイル）２にコンデンサ４（Ｃ１）を並列に入れて形成した並列共振回路５とを備えている。
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Configuration of non-contact stress measurement device by composite resonance method>
FIG. 1 is a schematic configuration diagram illustrating a non-contact stress measuring apparatus according to the composite resonance method of the first embodiment. FIG. 2 is an enlarged front view showing a state in which the stress sensor portion is mounted on the PC wire.
The non-contact stress measuring apparatus of the present invention includes a primary coil (excitation coil) 1 for exciting a wire w such as a PC wire and a secondary coil (feedback coil) 2 for returning the output of the excited wire w. The stress sensor unit 3 and a secondary coil (feedback coil) 2 that is magnetically coupled with the magnetic characteristics of the wire w between the primary coil (excitation coil) 1 and the secondary coil (feedback coil) 2 of the stress sensor unit 3. And a parallel resonance circuit 5 formed by putting a capacitor 4 (C1) in parallel.
この並列共振回路５のみでは、応力変化に伴う線材ｗの磁性体の磁気特性の変化は非常に微小な変化しか検出することができない。本発明では並列共振回路５に、二次コイル（帰還コイル）２側で生じる測定信号を入力する増幅器６を入れた。更に、増幅器６と一次コイル（励磁コイル）１の間に直列共振回路７を入れた。この直列共振回路７は、抵抗８及びコンデンサ９（Ｃ２）で形成される。更に、この直列共振回路７は、内部応力出力（ＤＣ）とコンデンサ１０（Ｃ３）により構成され、これら以外の必要部品と共に、非接触応力測定装置としてケース内にまとめられている。 Only this parallel resonance circuit 5 can detect only a very small change in the magnetic characteristics of the magnetic material of the wire rod w due to the change in stress. In the present invention, the parallel resonant circuit 5 is provided with an amplifier 6 for inputting a measurement signal generated on the secondary coil (feedback coil) 2 side. Further, a series resonance circuit 7 is inserted between the amplifier 6 and the primary coil (excitation coil) 1. The series resonant circuit 7 is formed by a resistor 8 and a capacitor 9 (C2). Further, the series resonance circuit 7 is constituted by an internal stress output (DC) and a capacitor 10 (C3), and together with other necessary components, is integrated in a case as a non-contact stress measuring device.
＜応力センサ部の構成＞
一次コイル（励磁コイル）１は、図２に示すように中心部に測定する強磁性のＰＣワイヤー等の線材ｗを貫通させるために、円筒形状のボビン１１にソレノイド状に巻線をしたものである。
<Configuration of stress sensor section>
As shown in FIG. 2, the primary coil (excitation coil) 1 has a cylindrical bobbin 11 wound in a solenoid shape so as to penetrate a wire w such as a ferromagnetic PC wire to be measured at the center. is there.
二次コイル（帰還コイル）２も、中心部に測定物の強磁性のＰＣワイヤー等の線材ｗを貫通させるために、同じボビン１１にソレノイド状に巻線したものである。一次コイル（励磁コイル）１と二次コイル（帰還コイル）２の中心部に測定する強磁性ワイヤーを貫通することにより、磁気閉ループを形成する。二次コイル２にはコンデンサ４により並列共振回路５を形成する。並列共振回路５の信号は、正帰還（β）の減衰器１２を介して適正な正帰還量を増幅器６に入力し、自励発振器として作動する。 The secondary coil (feedback coil) 2 is also wound around the same bobbin 11 in the form of a solenoid so that the wire w such as a ferromagnetic PC wire of the object to be measured penetrates in the center. A magnetic closed loop is formed by penetrating a ferromagnetic wire to be measured at the center of the primary coil (excitation coil) 1 and the secondary coil (feedback coil) 2. A parallel resonant circuit 5 is formed in the secondary coil 2 by a capacitor 4. The signal of the parallel resonance circuit 5 inputs an appropriate positive feedback amount to the amplifier 6 via the positive feedback (β) attenuator 12 and operates as a self-excited oscillator.
本発明の測定装置は簡単な装置であるために、コスト面から応力センサ部３のみを多数あるワイヤー等の線材ｗそれぞれに予め装着しておくことが可能になる。 Since the measuring apparatus of the present invention is a simple apparatus, it becomes possible to previously attach only the stress sensor unit 3 to each of the wire w such as a large number of wires from the cost viewpoint.
図１の概略構成図では、応力センサ部３が一次コイル（励磁コイル）１と二次コイル（帰還コイル）２とを並べられた構成を示しているが、このような構成に限定されない。図示していないが、ボビン１１の内部にソレノイド状の一次コイル（励磁コイル）１の上側に、二次コイル（帰還コイル）２を巻線した、二重構造のものでもよい。 In the schematic configuration diagram of FIG. 1, the stress sensor unit 3 shows a configuration in which a primary coil (excitation coil) 1 and a secondary coil (feedback coil) 2 are arranged. However, the configuration is not limited to such a configuration. Although not shown, a double structure in which a secondary coil (feedback coil) 2 is wound on the upper side of a solenoid-like primary coil (excitation coil) 1 inside the bobbin 11 may be used.
また、図２の装着状態に示すように、本発明では、中心部に測定する強磁性のＰＣワイヤー等の線材ｗを貫通させて使用するものである。既存の線材ｗに後から貫通させることが困難なことがある。そこで、図示していないが、応力センサ部３を線材ｗに後から装着できるように、応力センサ部３をその長手方向に２分割できる構造にして、その後自在に接合し得る構成にする。このとき内部の一次コイル（励磁コイル）１と二次コイル（帰還コイル）２共に２分割できる構成にする。この分割された両コイル１，２を線材ｗに自在に挟む構成にする。 Further, as shown in the mounted state of FIG. 2, in the present invention, a wire w such as a ferromagnetic PC wire to be measured is penetrated and used at the center. It may be difficult to penetrate the existing wire w later. Therefore, although not shown, the stress sensor unit 3 can be divided into two in the longitudinal direction so that the stress sensor unit 3 can be attached to the wire w later, and the structure can be freely joined thereafter. At this time, both the internal primary coil (excitation coil) 1 and the secondary coil (feedback coil) 2 can be divided into two. The divided coils 1 and 2 are freely sandwiched between the wire rods w.
＜測定原理の説明＞
実施例１の複合共振法による非接触応力測定装置では、直列共振周波数近傍になるコンデンサ９を介して一次コイル（励磁コイル）１で線材ｗを励磁（磁化）すると（直列共振電流）、この励磁された線材ｗの磁気特性により二次コイル（帰還コイル）２に電圧が誘起される。線材ｗが磁化されない場合の磁束より若干多くなる。並列共振回路５に組み込むと二次コイル（帰還コイル）２のインダクタンスは線材ｗから磁束が来る場合は相互インダクタンスとして作用する。
<Description of measurement principle>
In the non-contact stress measuring apparatus according to the composite resonance method of the first embodiment, when the wire w is excited (magnetized) with the primary coil (excitation coil) 1 via the capacitor 9 near the series resonance frequency (series resonance current), this excitation A voltage is induced in the secondary coil (feedback coil) 2 due to the magnetic characteristics of the wire w. It is slightly larger than the magnetic flux when the wire w is not magnetized. When incorporated in the parallel resonant circuit 5, the inductance of the secondary coil (feedback coil) 2 acts as a mutual inductance when a magnetic flux comes from the wire w.
この並列共振回路５のみでは、応力変化に伴う磁性体の磁気特性の変化について、非常に微小な変化しか検出できない。そこで、本発明は二次コイル（帰還コイル）２側で生じる測定信号を入力する増幅器６を備えた。二次コイル（帰還コイル）２にはコンデンサ４により並列共振回路５が形成されているので、この信号は正帰還（β）の減衰器１２を介し適正な正帰還量を増幅器６に入力し、自励発振器として作動させる。この増幅器６の出力は、線材ｗを励磁させ、同時に出力の一部から、負帰還（-β）の減衰器１３を介し増幅器６の安定を図る。 Only this parallel resonance circuit 5 can detect only a very small change in the change in the magnetic characteristics of the magnetic material due to the stress change. Therefore, the present invention includes an amplifier 6 for inputting a measurement signal generated on the secondary coil (feedback coil) 2 side. Since the parallel resonance circuit 5 is formed by the capacitor 4 in the secondary coil (feedback coil) 2, this signal inputs an appropriate positive feedback amount to the amplifier 6 via the attenuator 12 of the positive feedback (β), Operate as a self-excited oscillator. The output of the amplifier 6 excites the wire w and simultaneously stabilizes the amplifier 6 from a part of the output via the attenuator 13 of negative feedback (−β).
即ち、磁束密度Ｂは、線材ｗの磁気特性、測定装置の磁気回路など形状係数で変化する。例えば、増幅器６のオープンゲインは約８０dbで、負帰還により２６dbの利得で使用し、極めて安定な増幅度が得られる。増幅器６の出力に、直列共振回路７と一次コイル（励磁コイル）１を直列に接続して線材ｗを励磁する。一次コイル（励磁コイル）１の上に二次コイル（帰還コイル）２を同様に巻き線し、並列にコンデンサ４により並列共振回路５を形成する（Ｆ０２８０Ｈｚ）、この信号にＡＴＴを介し増幅器６の＋入力に接続し正帰還ループを形成する。 That is, the magnetic flux density B varies depending on the shape factor such as the magnetic characteristics of the wire w and the magnetic circuit of the measuring device. For example, the open gain of the amplifier 6 is about 80 db, and it is used with a gain of 26 db by negative feedback, so that a very stable amplification degree can be obtained. A series resonance circuit 7 and a primary coil (excitation coil) 1 are connected in series to the output of the amplifier 6 to excite the wire rod w. A secondary coil (feedback coil) 2 is similarly wound on the primary coil (excitation coil) 1, and a parallel resonant circuit 5 is formed by a capacitor 4 in parallel (F0280 Hz). This signal is sent to the amplifier 6 via an ATT. Connect to the + input to form a positive feedback loop.
二次コイル２（帰還コイル）の共振電圧値が一定になるよう発振ループは作動する。線材ｗの無負荷から最大負荷間で同様に作動する。このとき一次コイル（励磁コイル）１の両端電位は励磁電流に比例する。これを線材ｗの応力変化に伴う磁性体の磁気特性の変化として出力させ、線材ｗの張力の変化について測定することができる。 The oscillation loop operates so that the resonance voltage value of the secondary coil 2 (feedback coil) becomes constant. It operates similarly between the no load and the maximum load of the wire rod w. At this time, the potential across the primary coil (excitation coil) 1 is proportional to the excitation current. This can be output as a change in the magnetic properties of the magnetic material accompanying a change in the stress of the wire w, and the change in the tension of the wire w can be measured.
実施例１の複合共振法による非接触応力測定装置により、測定した実測値として、無負荷時電圧Ｐ−Ｐ１４Ｖ、電流Ｐ−Ｐ０．７Ａで、最大負荷時電圧Ｐ−Ｐ３０Ｖ、電流Ｐ−Ｐ１．４Ａ、Ｚ＝インピーダンス２０Ω−２１．４Ωを得た。 The measured values measured by the non-contact stress measuring apparatus according to the composite resonance method of Example 1 are as follows: no-load voltage P-P 14 V, current P-P 0.7 A, maximum load voltage P-P 30 V, current P-P 1. 4A, Z = impedance 20Ω-21.4Ω was obtained.
図３は増幅器における作用原理を示すグラフである。
グラフの横軸は、引張り荷重に対する一次コイル（励磁コイル）１の直列共振周波数及び同様に二次コイル（帰還コイル）２の並列共振周波数及び各共振スロープを示す。縦軸は、一次コイル（励磁コイル）１のインダクタンスＬとコンデンサ９（Ｃ２）による直列共振インピーダンスによる電圧・電流及び２次コイル（帰還コイル）２の並列共振電圧を示す。
FIG. 3 is a graph showing the principle of operation in the amplifier.
The horizontal axis of the graph shows the series resonance frequency of the primary coil (excitation coil) 1 and the parallel resonance frequency of the secondary coil (feedback coil) 2 and each resonance slope with respect to the tensile load. The vertical axis indicates the voltage / current due to the series resonance impedance of the primary coil (excitation coil) 1 and the capacitor 9 (C2) and the parallel resonance voltage of the secondary coil (feedback coil) 2.
無荷重時における二次コイル（帰還コイル）２の並列共振周波数ｆ１で、持続正帰還発振レベル（グラフ右側に記入）にしておく、引張り荷重の増加に伴いｆ１からｆ２に移行する。即ち、荷重が増加し二次コイル（帰還コイル）２の並列共振電圧が一定となるよう一次コイル（励磁コイル）１の直列共振電流を増幅器６により自動的に制御することができる。そこで、本発明の複合共振法による非接触応力測定方法では、純粋に高感度で再現性の高い測定が可能になる。 At the parallel resonance frequency f1 of the secondary coil (feedback coil) 2 when no load is applied, a continuous positive feedback oscillation level (written on the right side of the graph) is set, and the process shifts from f1 to f2 as the tensile load increases. That is, the series resonance current of the primary coil (excitation coil) 1 can be automatically controlled by the amplifier 6 so that the load increases and the parallel resonance voltage of the secondary coil (feedback coil) 2 becomes constant. Therefore, the non-contact stress measurement method by the composite resonance method of the present invention enables measurement with high sensitivity and high reproducibility.
このように本発明の複合共振法による非接触応力測定方法、測定装置は、ＰＣワイヤー等の線材ｗの張力測定に利用することができる。
ＰＣワイヤー等の線材ｗは荷重により微小に変化する。インダクタンス、透磁率、ヒステリシス損、渦電損を選択的に測定するには極めて困難であったが、本発明の正帰還増幅器６の正帰還発振によれば、変化するインダクタンス、透磁率、ヒステリシス損、渦電流損等のパラメータを選択できる。パラメータの内、実数項のヒステリシス損は、共振により複素項が打消され、実数項のみとなり、ヒステリシス損は、ＰＣワイヤー等の線材ｗの加重変化に対応することができる。
Thus, the non-contact stress measuring method and measuring apparatus by the composite resonance method of the present invention can be used for measuring the tension of the wire w such as PC wire.
The wire material w such as PC wire changes minutely depending on the load. Although it was extremely difficult to selectively measure inductance, magnetic permeability, hysteresis loss, and eddy current loss, according to the positive feedback oscillation of the positive feedback amplifier 6 of the present invention, changing inductance, magnetic permeability, hysteresis loss. Parameters such as eddy current loss can be selected. Among the parameters, the hysteresis loss of the real number term cancels the complex term due to resonance and becomes only the real number term, and the hysteresis loss can correspond to the weighted change of the wire w such as PC wire.
本発明の複合共振法により、振幅Ｈは数１の数式で示されるように、−αの値が０（発振状態）に近づくにつれ、回路全体の利得は急激に上がる。Ｑ値は数２の数式で、バンド幅は数３の数式で示されるように、上昇してバンド幅は元の値より狭くなる。１−αの値が０．０１の場合利得は１００倍になり、Ｑ値と選択度も元の回路より１００倍良くなる。即ち、精度の高い応力測定が可能になる。 With the composite resonance method of the present invention, the amplitude H increases as the value of −α approaches 0 (oscillation state), as indicated by the mathematical formula 1. The gain of the entire circuit increases rapidly. As the Q value is expressed by the mathematical formula 2 and the bandwidth is expressed by the mathematical formula 3, the bandwidth increases and the bandwidth becomes narrower than the original value. When the value of 1-α is 0.01, the gain is 100 times, and the Q value and selectivity are also 100 times better than the original circuit. That is, highly accurate stress measurement is possible.
＜張力測定試験（引張試験機）＞
図４は本発明の複合共振法による非接触応力測定装置により測定する線材を装着した状態を示す引張試験機を示す正面図である。
本発明の非接触応力測定装置の基礎データを、引張試験機２１を用いて採取した。図示するような引張試験機２１の上部に荷重検出器（ロード・セル）２２を固定し、これに試験片つかみ具(チャック)２３を連結した線材ｗ（鋼線ワイヤー）の上部を固定する。一方、線材ｗの下部はつかみ具２３で掴み，これを剛体枠下部２４に固定する。モーターで両側のフレーム２５にあるネジ棹２６を回転させることによって上下させ、線材ｗは一定の速度で引き伸ばされる。引張試験機２１の上下部試験片つかみ具２３に線材ｗ（鋼線ワイヤー）を取り付けて試験した。このとき、線材ｗには本発明の非接触応力測定装置の応力センサ部３を装着した。
<Tension measurement test (tensile tester)>
FIG. 4 is a front view showing a tensile tester showing a state in which a wire to be measured by a non-contact stress measuring apparatus using the composite resonance method of the present invention is mounted.
Basic data of the non-contact stress measuring device of the present invention was collected using a tensile tester 21. A load detector (load cell) 22 is fixed to the upper part of a tensile tester 21 as shown in the figure, and the upper part of a wire w (steel wire) to which a test piece gripping tool (chuck) 23 is connected is fixed thereto. On the other hand, the lower part of the wire rod w is grasped by the gripping tool 23 and fixed to the rigid frame lower part 24. By rotating the screw rods 26 in the frames 25 on both sides with a motor, the wire rod w is stretched at a constant speed. A wire w (steel wire) was attached to the upper and lower test piece gripping tool 23 of the tensile tester 21 and tested. At this time, the stress sensor unit 3 of the non-contact stress measuring device of the present invention was attached to the wire w.
＜張力測定試験（緊張力と電圧の関係）＞
図５は引張試験機による電圧（引張強度）と張力との関係を示すグラフである。図６は本発明の複合共振法による非接触応力測定装置により測定した緊張力と電圧の関係を示すグラフである。
試験機２１による上下の変化値について、図５と図６にあるように電圧で示した。この試験結果は表１の試験結果表に示すように引張試験機２１による電圧（引張強度）と張力との関係であった。試験は３回行った（電圧１、電圧２、電圧３）。図５にこの試験結果のグラフを示す。
<Tension measurement test (relationship between tension and voltage)>
FIG. 5 is a graph showing a relationship between voltage (tensile strength) and tension by a tensile tester. FIG. 6 is a graph showing the relationship between tension and voltage measured by a non-contact stress measuring apparatus using the composite resonance method of the present invention.
As shown in FIG. 5 and FIG. As shown in the test result table of Table 1, this test result was a relationship between the voltage (tensile strength) and tension by the tensile testing machine 21. The test was performed three times (Voltage 1, Voltage 2, Voltage 3). FIG. 5 shows a graph of the test results.
図６にあるように、張力の増加に伴い，電圧が増加した。１７０ｋＮの張力変化で約１３Ｖの電圧変化が出力できており、張力変化を比較的大きな電圧変化として検出することができた。また、繰り返し測定しても履歴はほぼ変わらず、極めて高い再現性を有している。なお、載荷時は除荷時に比べ、やや電圧が高く出力される傾向が確認された。このように載荷と除荷で若干異なる履歴を描く原因は、磁気ヒステリシスの影響と考えられる。 As shown in FIG. 6, the voltage increased as the tension increased. A voltage change of about 13 V could be output with a tension change of 170 kN, and the tension change could be detected as a relatively large voltage change. In addition, the history remains almost unchanged even when measured repeatedly, and has extremely high reproducibility. In addition, it was confirmed that the voltage was slightly higher during loading than when unloading. The reason for drawing a slightly different history between loading and unloading is considered to be the effect of magnetic hysteresis.
測定結果は図６のグラフに示すように機械的に引っ張り、その時の電圧（Ｖ）を縦軸に、張力（ｋＮ）を横軸で示す。このときの数式は数４に示す回帰式で計算した。この回帰式において、Ｔ：張力（ｋＮ）、ｅ：出力電圧（Ｖ）である。温度など諸要因の影響は考慮できていない状況ではあるが，仮に本結果から最小二乗法によりこの数式を導き出した。この数式は多項式とし、自由度調整済み決定係数が最も１に近くなる三次式とした。この実験ではＰＣ鋼撚り線を用いたて３回試験した。測定温度は１４．５℃であった。 As shown in the graph of FIG. 6, the measurement results are mechanically pulled, and the voltage (V) at that time is shown on the vertical axis and the tension (kN) is shown on the horizontal axis. The mathematical formula at this time was calculated by the regression equation shown in Equation 4. In this regression equation, T: tension (kN) and e: output voltage (V). Although the influence of various factors such as temperature has not been taken into account, this formula was derived from this result by the least square method. This mathematical formula is a polynomial, and is a cubic formula with the degree of freedom adjusted coefficient of determination closest to 1. In this experiment, the test was performed three times using a PC steel stranded wire. The measurement temperature was 14.5 ° C.
＜張力測定試験（張力推定）＞
図７は本発明の複合共振法による非接触応力測定装置により測定した線材の長さが２．０ｍの張力測定試験結果を示すグラフである。図８は本発明の複合共振法による非接触応力測定装置により測定した線材の長さが６．７ｍの張力測定試験結果を示すグラフである。
同じく本発明の非接触応力測定装置の基礎データを、引張試験機２１を用いて採取した結果を図６〜８に示す。引張試験機２１の上部に荷重検出器（ロード・セル）２２を固定し，さらにこれに試験片つかみ具(チャック)２３を連結し線材ｗとして鋼線ワイヤーの上部を固定する。一方、線材ｗの下部はつかみ具２３で掴み，これを剛体枠下部２４に固定する。モーターで両側のフレーム２５にあるネジ棹(さお)２６を回転させることによって上下し，線材ｗは一定の速度で引き伸ばされる。引張試験機の上下部試験片つかみ具２３に線材ｗとして鋼線ワイヤーを取り付けて試験した。
<Tension measurement test (tension estimation)>
FIG. 7 is a graph showing a tension measurement test result when the length of the wire measured by the non-contact stress measuring apparatus according to the composite resonance method of the present invention is 2.0 m. FIG. 8 is a graph showing the result of a tension measurement test in which the length of the wire measured by the non-contact stress measuring apparatus according to the composite resonance method of the present invention is 6.7 m.
Similarly, the basic data of the non-contact stress measuring device of the present invention are shown in FIGS. A load detector (load cell) 22 is fixed to the upper part of the tensile tester 21, and a test piece gripping tool (chuck) 23 is connected to the tensile tester 21 to fix the upper part of the steel wire as a wire rod w. On the other hand, the lower part of the wire rod w is grasped by the gripping tool 23 and fixed to the rigid frame lower part 24. By rotating screw rods 26 on the frames 25 on both sides by a motor, the wire rod w is stretched at a constant speed. A steel wire wire was attached to the upper and lower test piece gripping tool 23 of the tensile tester as a wire w and tested.
＜張力測定試験結果（張力推定）＞
図７のグラフに示すように、測定対象としては、線材ｗの長さが２．０ｍの鋼線について、３回試験した。鋼材の温度は９．５℃〜９．９℃の範囲で試験した。計測結果は図７のグラフの横軸にロードセル計測値（ｋＮ）を示し、縦軸に本発明の応力測定装置による計測値（ｋＮ）を示す。
同様に、図８のグラフに示すように、線材ｗの長さが６．７ｍの鋼線についても、３回試験した。このときの鋼材の温度は１６．４℃〜１６．７℃の範囲で試験した。図８のグラフの横軸にロードセル計測値（ｋＮ）を示し、縦軸に本発明の応力測定装置による計測値（ｋＮ）を示す。
表２の回帰式の精度の表に示すように、これらの試験結果から決定係数は略一定の数値を示し、本発明の複合共振法による非接触応力測定装置の測定精度が高いことを示している。
<Tension measurement test results (tension estimation)>
As shown in the graph of FIG. 7, as a measurement object, a steel wire having a wire w length of 2.0 m was tested three times. The temperature of the steel was tested in the range of 9.5 ° C to 9.9 ° C. The measurement result shows the load cell measurement value (kN) on the horizontal axis of the graph of FIG. 7, and the measurement value (kN) by the stress measurement device of the present invention on the vertical axis.
Similarly, as shown in the graph of FIG. 8, a steel wire having a wire w length of 6.7 m was also tested three times. The temperature of the steel material at this time was tested in the range of 16.4 ° C to 16.7 ° C. The horizontal axis of the graph of FIG. 8 shows the load cell measurement value (kN), and the vertical axis shows the measurement value (kN) by the stress measurement device of the present invention.
As shown in the accuracy table of the regression equation in Table 2, the coefficient of determination shows a substantially constant value from these test results, indicating that the measurement accuracy of the non-contact stress measuring device by the composite resonance method of the present invention is high. Yes.
張力により微小に変化するヒステリシス損失成分を一次コイルの両端差電圧を所定の信号として他の増幅手段を必要とせず再現性の高い信号が得られる。応力変化に伴う磁性体の磁気特性の変化は非常に微小な変化についてその測定精度を向上させることができる。
また、増幅の出力に抵抗及びコンデンサにより励磁電流の直列共振回路７によりヒステリシス損など損失による位相のずれを補正することで、正確に測定することができる。
A hysteresis loss component that changes minutely due to the tension can be obtained by using the differential voltage across the primary coil as a predetermined signal and without requiring other amplifying means. The change in the magnetic properties of the magnetic material accompanying the change in stress can improve the measurement accuracy for very small changes.
In addition, it is possible to measure accurately by correcting the phase shift due to loss such as hysteresis loss by the series resonance circuit 7 of the excitation current by the resistor and the capacitor at the output of amplification.
＜温度センサを設けた応力測定装置の構成＞
図９は実施例２の温度センサを設けた応力測定装置を示す概略構成図である。
実施例２の応力測定装置では、線材ｗの温度変化を測定する温度センサ３１を設けた。線材ｗの温度の変化値を用いて線材ｗの応力測定値を補正するためである。実際に使用されているＰＣワイヤー等の線材ｗは、気温が＋５０〜＋６０℃の気候の場所で使用されたり、逆に気温が−２０〜−３０℃の気候といった過酷な状況で使用されることがある。
<Configuration of stress measuring device with temperature sensor>
FIG. 9 is a schematic configuration diagram showing a stress measuring device provided with the temperature sensor of the second embodiment.
In the stress measuring device of Example 2, the temperature sensor 31 for measuring the temperature change of the wire w was provided. This is to correct the stress measurement value of the wire w using the change value of the temperature of the wire w. The wire w such as PC wire that is actually used should be used in harsh conditions such as a climate where the temperature is +50 to + 60 ° C or a climate where the temperature is -20 to -30 ° C. There is.
このような場合には、予め高温状況又は低温状況における測定値を温度センサ３１で採取しておき、線材ｗの温度の変化値を用いて線材ｗの応力測定値を補正することで、更に正確な測定値を得ることができる。なお、その他の装置、測定方法は実施例１と同様であるためその説明を省略する。 In such a case, the measurement value in the high temperature condition or the low temperature condition is collected in advance by the temperature sensor 31, and the stress measurement value of the wire w is corrected using the change value of the temperature of the wire w. Measured values can be obtained. Since other devices and measurement methods are the same as those in the first embodiment, description thereof is omitted.
なお、本発明は、線材ｗの応力変化に伴う磁気特性の微小変化を大きな変化値として検出することで、その測定精度を向上させることができれば、上述した発明の実施の形態に限定されず、本発明の要旨を逸脱しない範囲で種々変更できることは勿論である。 Note that the present invention is not limited to the above-described embodiment of the present invention, as long as the measurement accuracy can be improved by detecting a minute change in magnetic characteristics accompanying the stress change of the wire rod w as a large change value. Of course, various changes can be made without departing from the scope of the present invention.
本発明は、ＰＣワイヤー等の線材ｗの張力測定に限定されず、その他の応力変化を伴う金属材であれば測定に利用することができる。 The present invention is not limited to the measurement of the tension of the wire w such as a PC wire, and can be used for measurement as long as it is a metal material accompanied by other stress changes.
１ 一次コイル（励磁コイル）
２ 二次コイル（帰還コイル）
３ 応力センサ部
４ コンデンサ
５ 並列共振回路
６ 増幅器
７ 直列共振回路
８ 抵抗
９ コンデンサ
１０ コンデンサ
１２ 減衰器
１３ 減衰器
３１ 温度センサ
ｗ 線材（ＰＣワイヤー）
1 Primary coil (excitation coil)
2 Secondary coil (feedback coil)
DESCRIPTION OF SYMBOLS 3 Stress sensor part 4 Capacitor 5 Parallel resonance circuit 6 Amplifier 7 Series resonance circuit 8 Resistance 9 Capacitor 10 Capacitor 12 Attenuator 13 Attenuator 31 Temperature sensor w Wire material (PC wire)
Claims (5)
直列共振周波数近傍になるコンデンサ（９）を介して一次コイル（励磁コイル）（１）で前記線材（ｗ）を励磁し、この励磁された該線材（ｗ）の磁気特性により、二次コイル（帰還コイル）（２）に電圧を誘起させ、
前記二次コイル（帰還コイル）（２）とコンデンサ（４）により並列共振回路（５）を形成し、この信号は正帰還（β）の減衰器（１２）を介して、適正な正帰還量を増幅器（６）に入力することで自励発振器として作動させ、
前記増幅器（６）の出力は、前記線材（ｗ）を励磁させ、同時にその出力の一部から負帰還（−β）の減衰器（１３）を介して該増幅器（６）の安定を図り、
前記二次コイル（帰還コイル）（２）の共振電圧値が一定になるよう発振ループを作動させ、このとき前記一次コイル（励磁コイル）（１）の両端電位は励磁電流に比例するので、この励磁電流のヒステリシス損による位相のずれを補正して、前記線材（ｗ）の応力を測定する、ことを特徴とする複合共振法による非接触応力測定方法。 A non-contact stress measurement method by a composite resonance method for detecting a change in magnetic properties accompanying a stress change of a wire (w) such as a wire and measuring the stress of the wire (w),
The wire (w) is excited by a primary coil (excitation coil) (1) through a capacitor (9) near the series resonance frequency, and the secondary coil ( A voltage is induced in the feedback coil) (2),
A parallel resonance circuit (5) is formed by the secondary coil (feedback coil) (2) and the capacitor (4), and this signal is passed through an attenuator (12) of positive feedback (β) to provide an appropriate positive feedback amount. Is input to the amplifier (6) to operate as a self-excited oscillator,
The output of the amplifier (6) excites the wire (w), and simultaneously stabilizes the amplifier (6) from a part of the output via the negative feedback (−β) attenuator (13),
The oscillation loop is operated so that the resonance voltage value of the secondary coil (feedback coil) (2) becomes constant. At this time, the potential at both ends of the primary coil (excitation coil) (1) is proportional to the excitation current. A non-contact stress measurement method by a composite resonance method, wherein the stress of the wire (w) is measured by correcting a phase shift due to hysteresis loss of an excitation current.
前記線材（ｗ）を励磁する一次コイル（励磁コイル）（１）と、この励磁された線材（ｗ）の磁気特性により電圧が誘起される二次コイル（帰還コイル）（２）を内装した応力センサ部（３）と、
前記応力センサ部（３）の一次コイル（励磁コイル）（１）と二次コイル（帰還コイル）（２）間において、前記線材（ｗ）が有する磁気特性で磁気結合させる、該二次コイル（帰還コイル）（２）にコンデンサ（４）を並列に介して形成した並列共振回路（５）と、
前記二次コイル（帰還コイル）（２）側で生じる測定信号を増幅する増幅器（６）と、
前記増幅器（６）と前記一次コイル（励磁コイル）（１）の間に入れた、抵抗（８）及びコンデンサ（４）を介して形成される直列共振回路（７）と、を備え、
前記並列共振回路（５）の信号は正帰還（β）の減衰器（１２）を介して、適正な正帰還量を前記増幅器（６）に入力することで自励発振器として作動させ、
前記増幅器（６）の出力は、前記線材（ｗ）を励磁させ、同時にその出力の一部から負帰還（−β）の減衰器（１３）を介して該増幅器（６）の安定を図り、前記二次コイル（帰還コイル）（２）の共振電圧値が一定になるよう発振ループを作動させ、このとき前記一次コイル（励磁コイル）（１）の両端電位は励磁電流に比例するので、この励磁電流のヒステリシス損による位相のずれを補正して、該線材（ｗ）の応力を測定し得るように構成した、ことを特徴とする複合共振法による非接触応力測定装置。 A non-contact stress measuring device based on a composite resonance method for measuring the stress of the wire (w) by detecting a change in magnetic properties accompanying a stress change of the wire (w) such as a wire,
Stresses in which a primary coil (excitation coil) (1) for exciting the wire (w) and a secondary coil (feedback coil) (2) in which a voltage is induced by the magnetic characteristics of the excited wire (w) are provided. A sensor unit (3);
Between the primary coil (excitation coil) (1) and the secondary coil (feedback coil) (2) of the stress sensor part (3), the secondary coil (2) that is magnetically coupled with the magnetic properties of the wire (w) ( A parallel resonant circuit (5) formed by connecting a capacitor (4) in parallel to the feedback coil) (2);
An amplifier (6) for amplifying a measurement signal generated on the secondary coil (feedback coil) (2) side;
A series resonant circuit (7) formed between the amplifier (6) and the primary coil (excitation coil) (1) and formed through a resistor (8) and a capacitor (4),
The signal of the parallel resonant circuit (5) is operated as a self-excited oscillator by inputting an appropriate positive feedback amount to the amplifier (6) via an attenuator (12) of positive feedback (β),
The output of the amplifier (6) excites the wire (w), and simultaneously stabilizes the amplifier (6) from a part of the output via the negative feedback (−β) attenuator (13), The oscillation loop is operated so that the resonance voltage value of the secondary coil (feedback coil) (2) becomes constant. At this time, the potential at both ends of the primary coil (excitation coil) (1) is proportional to the excitation current. A non-contact stress measuring apparatus using a composite resonance method, wherein a phase shift due to hysteresis loss of an exciting current is corrected and the stress of the wire (w) can be measured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016015950A JP6352321B2 (en) | 2016-01-29 | 2016-01-29 | Non-contact stress measuring method and measuring apparatus by composite resonance method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016015950A JP6352321B2 (en) | 2016-01-29 | 2016-01-29 | Non-contact stress measuring method and measuring apparatus by composite resonance method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2017134013A JP2017134013A (en) | 2017-08-03 |
| JP6352321B2 true JP6352321B2 (en) | 2018-07-04 |
Family
ID=59504383
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2016015950A Active JP6352321B2 (en) | 2016-01-29 | 2016-01-29 | Non-contact stress measuring method and measuring apparatus by composite resonance method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6352321B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110247597B (en) * | 2019-06-21 | 2021-04-13 | 南京航空航天大学 | Excitation-circuit doubly salient motor field loss fault-tolerant power generation system and control method thereof |
| JP7446186B2 (en) | 2020-09-04 | 2024-03-08 | 国立大学法人京都大学 | Tension measurement method |
| KR102268085B1 (en) * | 2021-03-11 | 2021-06-22 | 주식회사 스마트인사이드에이아이 | Tensible force measurement system using coil sensor capable of temperature compensation |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05281063A (en) * | 1992-04-02 | 1993-10-29 | Nippon Steel Corp | Measuring device for tension of steel material |
| JP4253084B2 (en) * | 1999-04-08 | 2009-04-08 | 富士重工業株式会社 | Load measuring device |
| ITPD20010204A1 (en) * | 2001-08-09 | 2003-02-09 | Infm Istituto Naz Per La Fi Si | SENSOR AND METHOD OF MEASUREMENT OF STATIC AND DYNAMIC MICRODEFORMATIONS |
| JP3942463B2 (en) * | 2002-03-14 | 2007-07-11 | 前田建設工業株式会社 | Reinforced concrete stress measurement system for reinforced concrete structures |
| JP5035729B2 (en) * | 2008-04-28 | 2012-09-26 | 国立大学法人京都大学 | Tension measuring device |
-
2016
- 2016-01-29 JP JP2016015950A patent/JP6352321B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2017134013A (en) | 2017-08-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9593990B2 (en) | Stress monitoring device of elasto-magneto-electric (EME) effect type | |
| KR102020974B1 (en) | Rope damage diagnostic test device and rope damage diagnostic test method | |
| JP6352321B2 (en) | Non-contact stress measuring method and measuring apparatus by composite resonance method | |
| US7953562B2 (en) | Method and apparatus for measuring the stress or strain of a portion of a ferro-magnetic member | |
| CN108489641B (en) | Stress measuring device and method for prestressed steel strand | |
| JP2766929B2 (en) | Non-destructive inspection equipment | |
| JP2001133440A (en) | Nondestructive method for measuring aged deterioration of strength of ferromagnetic structural material | |
| Schoenekess et al. | Method to determine tensile stress alterations in prestressing steel strands by means of an eddy-current technique | |
| Tang et al. | Study of a steel strand tension sensor with difference single bypass excitation structure based on the magneto-elastic effect | |
| KR101001616B1 (en) | Reversible Magnetic Permeability Measurement Apparatus | |
| KR101143054B1 (en) | Apparatus and method for measuring the strength of quality of steel plate | |
| Jackiewicz et al. | New methodology of testing the stress dependence of magnetic hysteresis loop of the L17HMF heat resistant steel casting | |
| ITPD20010204A1 (en) | SENSOR AND METHOD OF MEASUREMENT OF STATIC AND DYNAMIC MICRODEFORMATIONS | |
| CN113176016A (en) | Steel strand stress detection method and device and use method thereof | |
| JP3159132B2 (en) | Method for measuring stress in steel pipes | |
| Schoenekess et al. | Special constructed and optimised eddy-current sensors for measuring force and strain in steel reinforced concrete | |
| KR101444716B1 (en) | Apparatus of non-destructive stress measurement of steel part for construction | |
| JP3173365B2 (en) | Stress measurement method using magnetostriction effect | |
| JP2007155429A (en) | Method and device for inspecting concrete structure | |
| JP2005315732A (en) | Instrument for measuring displacement of ferromagnetic body | |
| RU2654827C1 (en) | Sensor for measuring mechanical deformations | |
| RU2492459C1 (en) | Magnetoelastic transducer for determining mechanical stresses in ferromagnetic materials | |
| RU2672978C1 (en) | Method for detecting defects in a long-dimensional ferromagnetic object | |
| SU1803785A1 (en) | Method and device for estimating fatigue life of structure components | |
| Schonekess et al. | Improved multi-sensor for force measurement on pre-stressed steel cables by means of eddy current technique |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20170718 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20180517 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20180521 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20180606 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6352321 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |