JPH0145575B2 - - Google Patents
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- Publication number
- JPH0145575B2 JPH0145575B2 JP55088807A JP8880780A JPH0145575B2 JP H0145575 B2 JPH0145575 B2 JP H0145575B2 JP 55088807 A JP55088807 A JP 55088807A JP 8880780 A JP8880780 A JP 8880780A JP H0145575 B2 JPH0145575 B2 JP H0145575B2
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- Prior art keywords
- magnetic flux
- coil
- phase difference
- detected
- excitation coil
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
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- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Measuring Magnetic Variables (AREA)
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Description
本発明は、例えば積層された電気鉄板から成る
回転電機等の積層鉄心の、旋削加工時に生じる層
間短絡、つまり加工ブリツジ等を、磁気的手段に
より容易に検出し得るようにした電磁誘導検査装
置に関する。
従来、電気機器例えば回転電機の鉄心は、寸法
精度上積層された回転子鉄心の外旋、或いは固定
子鉄心を内旋することがある。また、このような
回転電機はその特性試験を行なうと、当初の設計
値に対して予想以上の高い損失を示すことがあ
る。その原因は、鉄心旋削時に生じる層間短絡つ
まり加工ブリツジに起因するものが多い。そのた
め、回転電機の組立前にこの鉄心における加工ブ
リツジの有無の検出が必要となる。
ところで、従来このような加工ブリツジの有無
を検出するには、例えば回転子鉄心の場合には、
試験用の固定子鉄心との組合せ磁気試験によつて
行なうとか、或いは旋削された鉄心表面に励磁コ
イルと磁束検出コイルとを有するプローブを配設
して、このプローブにより局部鉄損を測定するよ
うな方法等がとられている。
しかしながら、まず前者の方法においては、量
産機種に対しては有効な手段であるが、大形機の
ような受注生産機種でその回転子の形状が異なる
ようなときは不適当なものとなる。また、後者の
方法においては、どのような機種に対しても適用
することができる反面、その測定精度が劣つてし
まうという欠点がある。
本発明は上述のような問題点を解決するために
成されたもので、その目的は位相角の変化をとら
えて積層鉄心の特性を容易にしかも高精度にて検
出することが可能な信頼性の高い電磁誘導検査装
置を提供することにある。
上記の目的を達成するために本発明では、被測
定部材である積層鉄心の表面に近接して設けら
れ、当該積層鉄心を磁化するための励磁コイルと
この励磁コイルの主磁束を検出する主磁束検出コ
イルと励磁コイル外部の磁束を検出する外部磁束
検出コイルとを備えたプローブと、励磁コイルに
高周波電流を通電する高周波電源と、主磁束検出
コイルにより検出される主磁束と外部磁束検出コ
イルにより検出される励磁コイル外部の磁束との
位相差を検出する位相差検出部と、この位相差検
出部により検出される位相差から鉄損値を算出す
る鉄損演算部と、この鉄損演算部により算出され
た鉄損値から積層鉄心の特性を検出する判定部と
を備えた構成とするようにしている。
本発明は、導電材を高周波で励磁した際に導電
材に生ずる渦電流が、プローブの励磁コイル近傍
における磁束の位相に変化を与えることを利用し
て、積層鉄心の加工ブリツジ等、導電材から成る
構造部材の特性を検出するようにしたものであ
る。
以下、示す図面を参照して本発明の一実施例に
ついて説明する。
第１図は、加工ブリツジを検出するための電磁
誘導検査装置の構成例を示すブロツク図である。
第１図において、１は被測定部材であり、例えば
けい素鋼帯の積層鉄心（回転子鉄心）である。一
方、２は被測定部材１に近接して設け、それを高
周波電源３により高周波電流を通電して磁化する
（検査）プローブの励磁コイル、４はプローブの
主磁束検出コイル、５は被測定部材１により左右
される励磁コイル２外部の磁束を検出するコイ
ル、６は各磁束検出コイル４，５によつて検出さ
れる主磁束と励磁コイル２外部の磁束との位相差
を検出する位相差検出部、７は位相差検出部６に
より検出される位相差から鉄損を算出する鉄損演
算部、８は鉄損演算部７の演算結果である鉄損値
から鉄心加工ブリツジの良否、つまり積層鉄心の
層間短絡の度合を判定する判定部である。ここ
で、励磁コイル２と、主磁束検出コイル４と、外
部磁束検出コイル５とから、プローブ９を構成し
ている。
次に、かかる構成の電磁誘導検査装置の作用に
ついて述べる。
いま、被測定部材１における加工ブリツジの有
無を検出するにあたり、励磁用高周波電源３より
プローブ９の励磁コイル２に高周波電流を通電す
ると、電磁誘導の原理によつて、プローブ９の主
磁束検出コイル４及び外部磁束検出コイル５に磁
束が生ずる。これにより、夫々の磁束検出コイル
４，５によつて検出された磁束が位相差検出部６
に導入され、ここにおいてその各磁束、すなわち
主磁束と励磁コイル２外部の磁束との位相差が検
出される。次に、この位相差検出部６の位相差信
号は鉄損演算部７に導入され、ここで所定の演算
式に基づいてその鉄損値が算出され、これより次
段の判定部８に加えられる。そして、最終的にこ
の判定部８において、被測定部材１における加工
ブリツジの良否、つまり層間短絡の度合が判定さ
れ、例えばその旨の表示等が行なわれる。ここ
で、被測定部材１に加工ブリツジが無い場合に
は、位相差検出部６において検出される磁束の位
相差は零であり、また加工ブリツジが存在する場
合には、その度合いに応じて磁束位相差が検出さ
れ、被測定部材１の一特性である加工ブリツジが
検出されることになる。
以下、この点についてより詳細に述べる。
いま、励磁用高周波電源３よりプローブ９の励
磁コイル２に高周波電流を通電すると、励磁コイ
ル２に流れる励磁電流によつて磁束が生じると共
に、被測定部材１に流れる渦電流によつて磁束が
生じる。この場合、励磁コイル２に流れる励磁電
流と被測定部材１に流れる渦電流には位相のずれ
があり、例えば被測定部材１が鉄の時には、被測
定部材１に流れる渦電流は励磁コイル２に流れる
励磁電流より約45゜の遅れとなり、また被測定部
材１が銅やアルミの時には、被測定部材１に流れ
る渦電流は励磁コイル２に流れる励磁電流より約
90゜の遅れとなる。この結果、励磁コイル２に流
れる励磁電流の作る磁束と、被測定部材１に流れ
る渦電流の作る磁束には位相差が生じる。一方、
主磁束検出コイル４と鎖交する磁束は、ほとんど
が励磁コイル２に流れる励磁電流の作る磁束であ
り、また外部磁束検出コイル５と鎖交する磁束
は、励磁コイル２に流れる励磁電流の作る磁束と
被測定部材１に流れる渦電流の作る磁束との合成
磁束である。このため、主磁束検出コイル４から
の出力と、外部磁束検出コイル５からの出力との
間には位相差が生じ、かつこの位相差は被測定部
材１に流れる渦電流の大小に対応する。すなわ
ち、被測定部材１が例えば積層鉄心である時、層
間絶縁が不良で鉄板間に層間短絡があれば渦電流
が流れ、この渦電流が大きい時は各磁束検出コイ
ル４，５の出力間の位相差も大きい。一方、この
層間短絡は積層鉄心の鉄損増加をもたらす好まし
くない状態であることから、各磁束検出コイル
４，５の出力間の位相差も大きく検出された場合
には積層鉄心の層間短絡が推定され、その鉄心は
不良品と判定される。従つて、この各磁束検出コ
イル４，５の出力間の位相差を検出することによ
つて渦電流の量を推定でき、これにより被測定部
材１の特性を検出することができる。
なお、上記において、各磁束検出コイル４，５
の出力間の位相差を検出する方法としては、例え
ば電力（本文では鉄損と表現している）を読む方
法がある。すなわち、いま励磁コイル２に流れる
励磁電流を〓、主磁束検出コイル４の出力を〓0、
外部磁束検出コイル５の出力を〓とする時、
〓＝ｉ sinωt
とすれば、
〓0＝e0cosωt
また
〓＝ｅ cos（ωt＋α）
｜〓×（〓・ｋ〓0）｜＝Ｐ
（ｅ＝ke0となるようにｋを合せると精度が良い）
を電力として読む。この場合、位相差α＝０なら
ばｋがいくらであつても電力Ｐ＝０となり、位相
差αが大となれば電力Ｐも大となる。
因に、第２図は被測定部材１の表面に、プロー
ブ９の励磁コイル２を約10mmの位置に近接して設
け、被測定部材１の表面を励磁周波数1000ヘルツ
にて磁化した場合の、励磁コイル２近傍における
磁束密度及び磁磁電流に対する磁束の位相差を、
数値解析により算出した箇所を示すもので、図中
１０〜１５は夫々その解析点を示すものである。
一方、表は被測定部材１において、その鉄心旋削
時に加工ブリツジの無い鉄心１、0.01mmの表面層
で加工ブリツジした鉄心２、及び加工ブリツジの
度合２の1/2程度の鉄心３の場合の夫夫について、
上記第２図に示す各解析点の磁束密度及びその位
相を示したものである。なお、表において各解析
点の磁束の位相は、励磁コイル２内の中心の磁束
（コイル４の磁束）を基準に示している。
The present invention relates to an electromagnetic induction inspection device that can easily detect, by magnetic means, interlayer short circuits, that is, machining bridges, etc., that occur during turning of a laminated iron core of a rotating electric machine or the like made of laminated electric iron plates, for example. . 2. Description of the Related Art Conventionally, in order to ensure dimensional accuracy, a rotor core of an electric device such as a rotating electric machine is externally rotated, or a stator core is internally rotated. Furthermore, when such a rotating electrical machine is subjected to a characteristic test, it may show a higher loss than expected compared to the original design value. The cause is often due to interlayer short circuits, or machining bridges, that occur during core turning. Therefore, it is necessary to detect the presence or absence of machining bridges in this iron core before assembling the rotating electric machine. By the way, conventionally, in order to detect the presence or absence of such machining bridges, for example, in the case of a rotor core,
This can be done by a combined magnetic test with a stator core for testing, or by arranging a probe with an excitation coil and a magnetic flux detection coil on the surface of the turned core, and measuring the local core loss using this probe. methods are being taken. However, although the former method is effective for mass-produced models, it is inappropriate for large-sized machines that are made to order and have different rotor shapes. Furthermore, although the latter method can be applied to any model, it has the disadvantage that its measurement accuracy is inferior. The present invention was made to solve the above-mentioned problems, and its purpose is to improve the reliability of detecting the characteristics of a laminated iron core easily and with high precision by capturing changes in phase angle. The purpose of the present invention is to provide an electromagnetic induction inspection device with high quality. In order to achieve the above object, the present invention provides an excitation coil that is provided close to the surface of a laminated core that is a member to be measured and that magnetizes the laminated core, and a main magnetic flux that detects the main magnetic flux of this excitation coil. A probe equipped with a detection coil and an external magnetic flux detection coil that detects magnetic flux outside the excitation coil, a high-frequency power supply that supplies high-frequency current to the excitation coil, and a main magnetic flux detected by the main magnetic flux detection coil and an external magnetic flux detection coil. A phase difference detection section that detects a phase difference with the detected magnetic flux outside the excitation coil, an iron loss calculation section that calculates an iron loss value from the phase difference detected by this phase difference detection section, and this iron loss calculation section. The configuration includes a determination unit that detects the characteristics of the laminated core from the iron loss value calculated by the above. The present invention utilizes the fact that eddy currents generated in a conductive material when the conductive material is excited at high frequency change the phase of magnetic flux near the excitation coil of a probe, thereby making it possible to remove conductive material from a conductive material such as a processed bridge of a laminated iron core. This system is designed to detect the characteristics of structural members made up of the following structures. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of the configuration of an electromagnetic induction inspection device for detecting machining bridges.
In FIG. 1, reference numeral 1 indicates a member to be measured, such as a laminated core (rotor core) of silicon steel strips. On the other hand, 2 is an excitation coil of a probe that is installed close to the member to be measured 1 and is magnetized (inspected) by applying a high-frequency current to it by a high-frequency power supply 3, 4 is the main magnetic flux detection coil of the probe, and 5 is the member to be measured. 1 is a coil that detects the magnetic flux outside the exciting coil 2, and 6 is a phase difference detection that detects the phase difference between the main magnetic flux detected by each magnetic flux detection coil 4, 5 and the magnetic flux outside the exciting coil 2. part, 7 is an iron loss calculation part that calculates iron loss from the phase difference detected by the phase difference detection part 6, and 8 is a calculation result of the iron loss calculation part 7, which is used to calculate the quality of the iron core processing bridge, that is, the lamination. This is a determination unit that determines the degree of interlayer short circuit in the iron core. Here, the probe 9 is composed of the excitation coil 2, the main magnetic flux detection coil 4, and the external magnetic flux detection coil 5. Next, the operation of the electromagnetic induction inspection device having such a configuration will be described. Now, when detecting the presence or absence of machining bridges in the member to be measured 1, when a high frequency current is applied from the excitation high frequency power supply 3 to the excitation coil 2 of the probe 9, the main magnetic flux detection coil of the probe 9 4 and the external magnetic flux detection coil 5. As a result, the magnetic flux detected by the respective magnetic flux detection coils 4 and 5 is transmitted to the phase difference detection section 6.
Here, the phase difference between each of the magnetic fluxes, that is, the main magnetic flux and the magnetic flux outside the exciting coil 2 is detected. Next, the phase difference signal from the phase difference detection section 6 is introduced into the iron loss calculation section 7, where the iron loss value is calculated based on a predetermined calculation formula. It will be done. Finally, the determination section 8 determines the quality of the processed bridge in the member to be measured 1, that is, the degree of interlayer short circuit, and displays, for example, a display to that effect. Here, if there is no machining bridge in the member to be measured 1, the phase difference of the magnetic flux detected by the phase difference detection section 6 is zero, and if a machining bridge exists, the magnetic flux changes depending on the degree of the machining bridge. The phase difference is detected, and the machining bridge, which is a characteristic of the member 1 to be measured, is detected. This point will be described in more detail below. Now, when a high-frequency current is applied to the excitation coil 2 of the probe 9 from the excitation high-frequency power supply 3, a magnetic flux is generated by the excitation current flowing through the excitation coil 2, and a magnetic flux is also generated by the eddy current flowing through the member to be measured 1. . In this case, there is a phase shift between the excitation current flowing in the excitation coil 2 and the eddy current flowing in the member to be measured 1. For example, when the member to be measured 1 is iron, the eddy current flowing in the member to be measured 1 flows into the excitation coil 2. The eddy current flowing through the measuring object 1 lags behind the excitation current by about 45 degrees, and when the measuring object 1 is made of copper or aluminum, the eddy current flowing through the measuring object 1 lags behind the exciting current flowing through the exciting coil 2.
There will be a delay of 90°. As a result, a phase difference occurs between the magnetic flux created by the exciting current flowing through the exciting coil 2 and the magnetic flux created by the eddy current flowing through the member to be measured 1. on the other hand,
The magnetic flux interlinking with the main magnetic flux detection coil 4 is mostly the magnetic flux created by the excitation current flowing through the excitation coil 2, and the magnetic flux interlinking with the external magnetic flux detection coil 5 is the magnetic flux created by the excitation current flowing through the excitation coil 2. This is the composite magnetic flux of the magnetic flux generated by the eddy current flowing through the member 1 to be measured. Therefore, a phase difference occurs between the output from the main magnetic flux detection coil 4 and the output from the external magnetic flux detection coil 5, and this phase difference corresponds to the magnitude of the eddy current flowing through the member to be measured 1. That is, when the member 1 to be measured is a laminated iron core, for example, if the interlayer insulation is poor and there is an interlayer short circuit between the iron plates, an eddy current will flow, and when this eddy current is large, the voltage between the outputs of the magnetic flux detection coils 4 and 5 will flow. The phase difference is also large. On the other hand, since this interlayer short circuit is an unfavorable condition that increases iron loss in the laminated core, if a large phase difference between the outputs of the magnetic flux detection coils 4 and 5 is also detected, an interlayer short circuit in the laminated core is assumed. The core was determined to be defective. Therefore, by detecting the phase difference between the outputs of the magnetic flux detection coils 4 and 5, the amount of eddy current can be estimated, and thereby the characteristics of the member to be measured 1 can be detected. In addition, in the above, each magnetic flux detection coil 4, 5
As a method of detecting the phase difference between the outputs, there is, for example, a method of reading electric power (expressed as iron loss in the text). That is, the excitation current flowing through the excitation coil 2 is 〓, the output of the main magnetic flux detection coil 4 is 〓 0 ,
When the output of the external magnetic flux detection coil 5 is 〓, if 〓=i sinωt, then 〓 0 = e 0 cosωt and 〓=e cos (ωt+α) |〓×(〓・k〓 0 )|=P (e The accuracy is better if you match k so that = ke 0 ) is read as power. In this case, if the phase difference α=0, the power P will be 0 no matter how much k is, and as the phase difference α becomes larger, the power P will also become larger. Incidentally, FIG. 2 shows the case where the excitation coil 2 of the probe 9 is placed close to the surface of the member to be measured 1 at a position of approximately 10 mm, and the surface of the member to be measured 1 is magnetized at an excitation frequency of 1000 Hz. The magnetic flux density near the excitation coil 2 and the phase difference of the magnetic flux with respect to the magneto-magnetic current are
It shows the points calculated by numerical analysis, and numbers 10 to 15 in the figure show the analysis points, respectively.
On the other hand, the table shows the cases of core 1 with no machining bridging during core turning, core 2 with machining bridging with a surface layer of 0.01 mm, and core 3 with a degree of machining bridging of approximately 1/2 of 2 in the measured member 1. About my husband,
This figure shows the magnetic flux density and its phase at each analysis point shown in FIG. 2 above. In addition, in the table, the phase of the magnetic flux at each analysis point is shown based on the magnetic flux at the center within the excitation coil 2 (magnetic flux of the coil 4).
【表】
この表からわかるように、加工ブリツジの度合
は磁束密度よりその位相角との間に良い相関関係
があり、またこれは励磁コイル２の外部において
顕著である。つまり、被測定部材１の一つの特性
である加工ブリツジを検出するには、励磁コイル
２内の磁束の位相より、励磁コイル２近傍の磁束
の位相に大きく現われることが明らかであり、こ
の励磁コイル２近傍の磁束の位相を検出すれば容
易に行なうことが可能である。なお、本実施例に
おいては磁束位相差検出の後処理、つまり装置製
作上の簡易さ、安定性から、位相比較は主磁束を
主体としたもので、磁束検出には磁束検出コイル
を用い、例えば位相測定用の検出位置が第２図の
点１３の場合は励磁コイル２軸と直角方向の磁束
成分を、また検出位置が点１５の場合は平行成分
の比較で、加工ブリツジの有無の検出を行なつて
いるものである。すなわち、位相測定用の検出位
置（主磁束検出コイル４を基準とした場合の）、
換言すれば外部磁束検出コイル５の位置選定につ
いては、前表に示した解析結果から本実施例の回
転子鉄心の場合、点１３，１５となるようにプロ
ーブ９を構成すれば、最も効果的な位相差検出を
行なうことができるものである。
このように、けい素鋼帯の積層鉄心より成る被
測定部材（回転子鉄心）１の加工ブリツジを検出
するにあたり、被測定部材１である積層鉄心の表
面に、高周波電源３により励磁される励磁コイル
２と、主磁束検出用の主磁束検出コイル４と、外
部磁束検出用の外部磁束検出コイル５とを備えた
プローブ９を近接して設け、励磁コイル２に高周
波励磁電流を通電してこの励磁コイル２近傍の磁
束を外部磁束検出コイル５にて検出し、且つこの
励磁コイル２近傍（外部）の磁束と上記主磁束と
の位相差を位相差検出部６にて検出することによ
り、被測定部材１の一特性である加工ブリツジの
良否を、鉄損演算部７及び判定部８により検出す
るようにしたものである。
従つて、被測定部材１である積層鉄心における
加工ブリツジの有無を、容易にしかも極めて高い
精度でもつて検出することが可能となり、その信
頼性を大幅に向上させることができる。また、こ
のような検出手段は、量産機種或いは受注生産機
種で回転子形状が異なるようなもの等、どのよう
な機種に対しても適用することが可能であり、そ
の信頼性のより高い装置が得られる。更に、その
装置構成としては前述したように簡単なものであ
る為、経済的にも有利なものである。
尚、本発明は上記実施例に限定されるものでは
なく、次のようにしても同様に実施することがで
きるものある。
(1) 上記実施例においては、被測定部材として、
回転子鉄心の加工ブリツジを検出する場合につ
いて述べたものであるが、これに限らず例えば
前述にて検出した磁束の位相差を基に、回転子
鉄心の渦流探傷或いは電気導電度等のその他の
特性を測定してそれを表示するように構成して
もよいものである。またこの場合、特に渦流探
傷について考えた時、回転子鉄心にクラツク或
いは異物混入等異常個所があることを検出した
場合にのみ装置が動作するように構成すること
が考えられる。
(2) 上記実施例においては、磁束検出にあたつて
磁束検出コイルを用いたものであるが、これの
みならずその他の磁束検出用素子を用いてもよ
いことは言うまでもない。
以上説明したように本発明によれば、被測定部
材である積層鉄心の表面に近接して設けられ、当
該積層鉄心を磁化するための励磁コイルとこの励
磁コイルの主磁束を検出する主磁束検出コイルと
励磁コイル外部の磁束を検出する外部磁束検出コ
イルとを備えたプローブと、励磁コイルに高周波
電流を通電する高周波電源と、主磁束検出コイル
により検出される主磁束と外部磁束検出コイルに
より検出される励磁コイル外部の磁束との位相差
を検出する位相差検出部と、この位相差検出部に
より検出される位相差から鉄損値を算出する鉄損
演算部と、この鉄損演算部により算出された鉄損
値から積層鉄心の特性を検出する判定部とを備え
た構成としたので、積層鉄心の特性を容易にしか
も高精度にて検出することが可能な極めて信頼性
の高い電磁誘導検査装置が提供できる。[Table] As can be seen from this table, the degree of machining bridging has a better correlation with the phase angle than with the magnetic flux density, and this is noticeable outside the excitation coil 2. In other words, in order to detect machining bridges, which are one of the characteristics of the member to be measured 1, it is clear that the phase of the magnetic flux near the exciting coil 2 appears larger than the phase of the magnetic flux inside the exciting coil 2. This can be easily done by detecting the phase of two magnetic fluxes. In this example, for post-processing of magnetic flux phase difference detection, that is, for simplicity and stability in device production, phase comparison is mainly based on the main magnetic flux, and a magnetic flux detection coil is used for magnetic flux detection, e.g. If the detection position for phase measurement is point 13 in Figure 2, the magnetic flux component in the direction perpendicular to the two axes of the exciting coil is compared, and if the detection position is point 15, the parallel component is compared to detect the presence or absence of machining bridges. This is what is being done. That is, the detection position for phase measurement (based on the main magnetic flux detection coil 4),
In other words, regarding the position selection of the external magnetic flux detection coil 5, in the case of the rotor core of this embodiment, it is most effective if the probe 9 is configured to be at points 13 and 15, based on the analysis results shown in the previous table. This makes it possible to perform accurate phase difference detection. In this way, when detecting machining bridges in the member to be measured (rotor core) 1 made of a laminated core made of silicon steel strips, the surface of the laminated core, which is the member to be measured 1, is energized by the high-frequency power source 3. A probe 9 comprising a coil 2, a main magnetic flux detection coil 4 for detecting the main magnetic flux, and an external magnetic flux detection coil 5 for detecting the external magnetic flux is provided adjacently, and a high-frequency excitation current is applied to the excitation coil 2 to detect this. The magnetic flux near the excitation coil 2 is detected by the external magnetic flux detection coil 5, and the phase difference between the magnetic flux near the excitation coil 2 (external) and the main magnetic flux is detected by the phase difference detection section 6. The quality of machining bridge, which is one of the characteristics of the measuring member 1, is detected by an iron loss calculating section 7 and a determining section 8. Therefore, the presence or absence of machining bridges in the laminated core, which is the member to be measured 1, can be detected easily and with extremely high accuracy, and its reliability can be greatly improved. In addition, such a detection means can be applied to any type of machine, including mass-produced models or models made to order with different rotor shapes, and it is possible to use a more reliable device. can get. Furthermore, since the device configuration is simple as described above, it is economically advantageous. It should be noted that the present invention is not limited to the above-mentioned embodiments, but can also be implemented in the following manner. (1) In the above embodiment, as the member to be measured,
This is not limited to the case of detecting machining bridges in the rotor core. For example, based on the phase difference of the magnetic flux detected above, eddy current flaw detection of the rotor core or other methods such as electrical conductivity can be detected. It may also be configured to measure and display characteristics. In this case, especially when considering eddy current flaw detection, it is conceivable to configure the device so that it operates only when an abnormality such as a crack or foreign matter is detected in the rotor core. (2) In the above embodiment, a magnetic flux detection coil is used for magnetic flux detection, but it goes without saying that not only this but other magnetic flux detection elements may be used. As explained above, according to the present invention, an excitation coil that is provided close to the surface of a laminated core that is a member to be measured and that magnetizes the laminated core and a main magnetic flux detection that detects the main magnetic flux of this excitation coil are provided. A probe equipped with a coil and an external magnetic flux detection coil that detects the magnetic flux outside the excitation coil, a high-frequency power supply that supplies high-frequency current to the excitation coil, and the main magnetic flux detected by the main magnetic flux detection coil and the external magnetic flux detection coil. A phase difference detection section that detects the phase difference with the magnetic flux outside the excitation coil, an iron loss calculation section that calculates an iron loss value from the phase difference detected by this phase difference detection section, and this iron loss calculation section. The structure is equipped with a determination section that detects the characteristics of the laminated core from the calculated iron loss value, so it is an extremely reliable electromagnetic induction system that can easily and accurately detect the characteristics of the laminated core. Inspection equipment can be provided.
第１図は本発明の一実施例を示す構成ブロツク
図、第２図は、本発明による数値解析結果を説明
するための図である。
１……被測定部材、２……励磁コイル、３……
高周波電源、４……主磁束検出コイル、５……外
部磁束検出コイル、６……位相差検出部、７……
鉄損演算部、８……判定部、９……プローブ。
FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram for explaining the results of numerical analysis according to the present invention. 1... Member to be measured, 2... Excitation coil, 3...
High frequency power supply, 4... Main magnetic flux detection coil, 5... External magnetic flux detection coil, 6... Phase difference detection section, 7...
Iron loss calculation section, 8...judgment section, 9...probe.
Claims (1)
設けられ、当該積層鉄心を磁化するための励磁コ
イルとこの励磁コイルの主磁束を検出する主磁束
検出コイルと前記励磁コイル外部の磁束を検出す
る外部磁束検出コイルとを備えたプローブと、前
記励磁コイルに高周波電流を通電する高周波電源
と、前記主磁束検出コイルにより検出される主磁
束と前記外部磁束検出コイルにより検出される励
磁コイル外部の磁束との位相差を検出する位相差
検出部と、この位相差検出部により検出される位
相差から鉄損値を算出する鉄損演算部と、この鉄
損演算部により算出された鉄損値から前記積層鉄
心の特性を検出する判定部とを備えた構成とした
ことを特徴とする電磁誘導検査装置。1. An excitation coil that is provided close to the surface of a laminated core that is a member to be measured and that magnetizes the laminated core, a main magnetic flux detection coil that detects the main magnetic flux of this excitation coil, and a magnetic flux outside the excitation coil. a high-frequency power source that supplies a high-frequency current to the excitation coil; a main magnetic flux detected by the main magnetic flux detection coil; and an external magnetic flux detection coil detected by the external magnetic flux detection coil; A phase difference detection section that detects the phase difference with magnetic flux, an iron loss calculation section that calculates an iron loss value from the phase difference detected by this phase difference detection section, and an iron loss value calculated by this iron loss calculation section. An electromagnetic induction inspection device comprising: a determination unit that detects characteristics of the laminated core.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8880780A JPS5713349A (en) | 1980-06-30 | 1980-06-30 | Inspection device for electromagnetic induction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8880780A JPS5713349A (en) | 1980-06-30 | 1980-06-30 | Inspection device for electromagnetic induction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5713349A JPS5713349A (en) | 1982-01-23 |
| JPH0145575B2 true JPH0145575B2 (en) | 1989-10-04 |
Family
ID=13953147
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8880780A Granted JPS5713349A (en) | 1980-06-30 | 1980-06-30 | Inspection device for electromagnetic induction |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5713349A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6378554B2 (en) * | 2014-06-26 | 2018-08-22 | 大日機械工業株式会社 | Nondestructive inspection apparatus and nondestructive inspection method |
| JP6374751B2 (en) * | 2014-10-02 | 2018-08-15 | アンリツインフィビス株式会社 | Metal detector |
| JP2020056754A (en) * | 2018-10-04 | 2020-04-09 | 株式会社ミツトヨ | Electromagnetic induction encoder |
-
1980
- 1980-06-30 JP JP8880780A patent/JPS5713349A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5713349A (en) | 1982-01-23 |
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