JPH04215030A - Magnetic sensor inspecting device - Google Patents
Magnetic sensor inspecting deviceInfo
- Publication number
- JPH04215030A JPH04215030A JP2401913A JP40191390A JPH04215030A JP H04215030 A JPH04215030 A JP H04215030A JP 2401913 A JP2401913 A JP 2401913A JP 40191390 A JP40191390 A JP 40191390A JP H04215030 A JPH04215030 A JP H04215030A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic sensor
- sound
- permanent magnet
- acoustic coupler
- abnormal
- 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.)
- Pending
Links
- 238000007689 inspection Methods 0.000 claims description 6
- 230000002159 abnormal effect Effects 0.000 abstract description 15
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 238000001228 spectrum Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000001953 sensory effect Effects 0.000 description 1
Landscapes
- Measuring Magnetic Variables (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
- Hall/Mr Elements (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は磁気センサの検査装置に
関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic sensor testing device.
【０００２】0002
【従来の技術】本発明は軟磁性体の磁気抵抗効果（ｅｆ
ｆｅｃｔ ｏｆ Ｍａｇｎｅｔ Ｒｅｓｉｓｔｉｖｅ＝
以下ＭＲ効果という）を応用したＭＲ素子及び永久磁石
とから構成された磁気センサに関したもので、永久磁石
は磁路を形成したり、磁気的なバイアスを印加するため
にＭＲ素子の背面に固定されている。用途としては例え
ばビデオテープレコーダー（ＶＴＲ）のテープ走行系回
転軸の回転速度制御用ＦＧとして用いられている。[Prior Art] The present invention focuses on the magnetoresistance effect (ef) of soft magnetic materials.
fect of Magnet Resistive=
This relates to a magnetic sensor composed of an MR element and a permanent magnet that apply the MR effect (hereinafter referred to as MR effect), where the permanent magnet is fixed to the back of the MR element to form a magnetic path and apply a magnetic bias. has been done. For example, it is used as an FG for controlling the rotational speed of the rotating shaft of the tape running system of a video tape recorder (VTR).
【０００３】前記の永久磁石を固定する方法として、セ
ンサーチップと共に樹脂の中に包埋する方法や、成型さ
れた筐体の中に挿入の後接着剤もしくはかしめ等で機械
的に固定する方法が用いられている。この際、前記した
永久磁石の固定強度が十分でない場合、磁気センサの使
用状態によっては信号磁界とは別にロータを回転させる
固定磁極から発生する交番磁界によって前記永久磁石に
駆動力が働き、筐体内の永久磁石が振動して異常な音が
発生する。この異常音の発生を検知すれば、永久磁石の
固定強度が適切であるかどうかは知ることができる。[0003] Methods for fixing the permanent magnet include embedding it in resin together with the sensor chip, and mechanically fixing it with adhesive or caulking after inserting it into a molded housing. It is used. At this time, if the fixed strength of the permanent magnet is not sufficient, depending on the usage state of the magnetic sensor, a driving force may act on the permanent magnet due to the alternating magnetic field generated from the fixed magnetic pole that rotates the rotor, in addition to the signal magnetic field, The permanent magnet of the machine vibrates and makes an abnormal sound. By detecting the occurrence of this abnormal sound, it is possible to know whether the fixing strength of the permanent magnet is appropriate.
【０００４】0004
【発明が解決しようとする課題】しかしながらこの種の
異常は磁気センサを基板に組み込み機構系を動作させて
初めて判明するものであり、磁気センサの通常工程内で
は判定が困難であった。これを事前に判定し異常品を取
り除くために、磁気センサを交番磁界内に置いて永久磁
石が異常音を発生するかどうか検査する場合、発生する
異常音は微弱でその音を聞き分けることは困難であった
。また、この異常音を単にマイクで収音し電気的に増幅
する方法では、周囲の騒音レベルの方が高く生産工程内
等周囲の騒音レベルが高い環境下ではその判定は不可能
であった。[Problems to be Solved by the Invention] However, this type of abnormality is only discovered after the magnetic sensor is installed on the board and the mechanical system is operated, and it has been difficult to determine this during the normal process of manufacturing the magnetic sensor. In order to determine this in advance and remove abnormal products, when placing a magnetic sensor in an alternating magnetic field and inspecting whether the permanent magnet generates an abnormal sound, the abnormal sound generated is weak and difficult to distinguish. Met. In addition, with the method of simply collecting this abnormal sound with a microphone and amplifying it electrically, it was impossible to determine the abnormal sound in an environment where the surrounding noise level is high, such as in a production process.
【０００５】本発明はこの課題を解決するために、微弱
な異常音の発生も適確に検知し、永久磁石とＭＲ素子と
の固定が不適切なものは確実に取り除く磁気センサの検
査装置を提供することを目的とする。[0005] In order to solve this problem, the present invention provides a magnetic sensor inspection device that accurately detects the occurrence of weak abnormal sounds and reliably removes permanent magnets and MR elements that are improperly fixed. The purpose is to provide.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するため
に、本発明は交番磁界を発生させる交番磁界発生手段と
、収音を行う音響カップラを備えこれに伴い出力信号を
出すマイクロフォンと、交番磁界を発生させる電源周波
数の逓倍値の何れかを中心周波数とし、マイクロフォン
からの出力信号を通過させるバンドパスフィルターと、
前記電源周波数で掃引周期を同期させバンドパスフィル
ターからの出力信号を入力とし信号の波形を表示するオ
シロスコープとを備えたものである。[Means for Solving the Problems] In order to achieve the above object, the present invention provides an alternating magnetic field generating means for generating an alternating magnetic field, an acoustic coupler for collecting sound, a microphone for outputting an output signal, and an alternating a bandpass filter whose center frequency is one of the multiplied values of the power supply frequency that generates the magnetic field, and which passes the output signal from the microphone;
The apparatus is equipped with an oscilloscope that synchronizes the sweep period with the power supply frequency, inputs the output signal from the bandpass filter, and displays the waveform of the signal.
【０００７】[0007]
【作用】本発明によれば、微弱な信号を周囲の騒音で妨
害されることなく検出でき、永久磁石とＭＲ素子との固
定が不適切な異常品を確実に取り除くことができる。According to the present invention, weak signals can be detected without being disturbed by surrounding noise, and abnormal products in which the permanent magnet and the MR element are improperly fixed can be reliably removed.
【０００８】[0008]
【実施例】以下、本発明の一実施例の磁気センサの検査
装置について図面を用いて説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic sensor inspection apparatus according to an embodiment of the present invention will be described below with reference to the drawings.
【０００９】図１は本実施例の構成を示したもので、検
出器１，増幅器２，バンドパスフィルター３，オシロス
コープ４とからなっている。検出器１は交番磁界発生用
の電磁石５と、その電源６，音響カップラ７，マイクロ
フォン８により構成されている。電磁石５には図のよう
に有芯型を用い、その電源６には６０（Ｈｚ）の商用電
源を用いて磁極間に２００（Ｏｅ）の磁界を発生させて
いる。音響カップラ７には塩ビ性のチューブを使い、そ
の内周にマイクロフォン８の外周を勘合させ固定してい
る。そして、被検体である磁気センサが前記電磁石５の
磁極のほぼ中心に位置するように音響カップラ７の先端
高さを調節する。バンドパスフィルター３は３ＫＨｚを
中心周波数にし、１２ｄＢ／ＯＣＴフィルター特性のも
のを用いる。オシロスコープ４は６０Ｈｚで外部トリガ
ーを印加して信号を同期させている。FIG. 1 shows the configuration of this embodiment, which includes a detector 1, an amplifier 2, a bandpass filter 3, and an oscilloscope 4. The detector 1 includes an electromagnet 5 for generating an alternating magnetic field, a power source 6 for the electromagnet 5, an acoustic coupler 7, and a microphone 8. A cored type electromagnet 5 is used as shown in the figure, and a 60 (Hz) commercial power source is used as the power source 6 to generate a magnetic field of 200 (Oe) between the magnetic poles. A vinyl chloride tube is used for the acoustic coupler 7, and the outer circumference of the microphone 8 is fitted and fixed to the inner circumference of the tube. Then, the height of the tip of the acoustic coupler 7 is adjusted so that the magnetic sensor, which is the object to be tested, is located approximately at the center of the magnetic pole of the electromagnet 5. The bandpass filter 3 has a center frequency of 3 KHz and a 12 dB/OCT filter characteristic. The oscilloscope 4 synchronizes the signal by applying an external trigger at 60 Hz.
【００１０】上記の構成の磁気センサの検査装置を用い
、磁気センサを音響カップラ７の上端の開講部を塞ぐよ
うに軽く押し当てて発生する振動音を測定すると、図２
に示すように振動音を発する異常品では１〜３個のピー
クがオシロスコープ４上で観察された。周囲環境の騒音
レベルが変化すると、オシロスコープ４上の輝線レベル
が変化するがピーク波形は崩れることなく再現でき、騒
音下での検査に十分実用性が得られた。また静寂な環境
下であっても、被検体である磁気センサに耳を近づけて
確認する官能試験では検出できない程の微弱な振動を発
する異常音でも本実施例によれば十分にオシロスコープ
４で認識でき、検出感度が十分でしかも再現性に優れる
ことを確認した。Using the magnetic sensor testing device having the above configuration, when the vibration sound generated by pressing the magnetic sensor lightly against the opening at the upper end of the acoustic coupler 7 is measured, the result is as shown in FIG.
As shown in FIG. 2, 1 to 3 peaks were observed on the oscilloscope 4 for abnormal products that emitted vibration sounds. When the noise level of the surrounding environment changes, the bright line level on the oscilloscope 4 changes, but the peak waveform can be reproduced without being distorted, making it sufficiently practical for inspection under noisy conditions. Furthermore, even in a quiet environment, this embodiment allows the oscilloscope 4 to recognize abnormal sounds that emit vibrations that are so weak that they cannot be detected in a sensory test in which the ear is brought close to the magnetic sensor. It was confirmed that the detection sensitivity was sufficient and the reproducibility was excellent.
【００１１】次に、音響カップラ７を設けた構成として
いる理由について述べる。図３は、図１に示した本実施
例により磁気センサが発する振動音をマイクロフォン８
で収音し、その周波数特性をスペクトルアナライザで解
析した結果を示したものである。音響カップラ７を用い
て収音した場合、連続スペクトルの中に、電磁石５の電
源周波数と、その逓倍周波数でピークが見られるが、音
響カップラ７を用いない場合、単にマイクロフォン８と
磁気センサとの間隔や周囲の騒音レベルによってＳ／Ｎ
比が決定してしまい、前記のピークのレベルも不安定に
なる。そこで音響カップラ７を用いることにより、周囲
からの騒音レベルを低下させ、ＭＲセンサが発生してい
る振動音を安定して検出することが可能となる。Next, the reason for the configuration in which the acoustic coupler 7 is provided will be described. FIG. 3 shows the vibration sound emitted by the magnetic sensor in the present embodiment shown in FIG.
This shows the results of collecting sound and analyzing its frequency characteristics with a spectrum analyzer. When sound is collected using the acoustic coupler 7, peaks can be seen in the continuous spectrum at the power frequency of the electromagnet 5 and its multiplied frequency, but when the acoustic coupler 7 is not used, the peaks are simply observed between the microphone 8 and the magnetic sensor. S/N depending on spacing and surrounding noise level
The ratio will be determined, and the level of the peak will also become unstable. Therefore, by using the acoustic coupler 7, it is possible to reduce the noise level from the surroundings and stably detect the vibration noise generated by the MR sensor.
【００１２】次にバンドパスフィルター３を設けた構成
とした理由を述べる。これはＳ／Ｎ比を向上させるため
である。Next, the reason for the configuration in which the bandpass filter 3 is provided will be described. This is to improve the S/N ratio.
【００１３】図３のスペクトルを見ると、連続スペクト
ル及びピーク高さは共に周波数の増加と共にレベルが低
下しているが、連続スペクトルとピークとのレベル比を
各周波数毎に見ると周波数の増加と共に向上していく。
このような特性を持つ信号をそのままオシロスコープ４
へ入力すると、音圧レベルの高い１００Ｈｚ以下の騒音
信号に隠れて磁気センサから発する振動音は確認できな
くなる。そこで本実施例のように前記ピークの周波数に
中心値を合わせたバンドパスフィルター４で信号を選択
通過させることによりＳ／Ｎ比を確保することを行う。Looking at the spectrum in FIG. 3, the level of both the continuous spectrum and the peak height decreases as the frequency increases, but when looking at the level ratio between the continuous spectrum and the peak for each frequency, the level decreases as the frequency increases. It will continue to improve. A signal with such characteristics can be directly transmitted to the oscilloscope 4.
, the vibration sound emitted from the magnetic sensor cannot be confirmed because it is hidden behind the noise signal of 100 Hz or less, which has a high sound pressure level. Therefore, as in this embodiment, the S/N ratio is ensured by selectively passing the signal through a band pass filter 4 whose center value is set to the frequency of the peak.
【００１４】なお、異常音発生の判定精度，作業性を高
めるため、オシロスコープ４に電源６の周波数で外部よ
りトリガーを印加し、掃引速度を同期させて検出信号を
監視すれば、周囲環境からイレギュラーな騒音を発した
場合にも磁気センサから発する振動音の音圧ピークはオ
シロスコープ４上の一定位置に表示されるため判定が容
易になる。[0014] In order to improve the accuracy of determining abnormal noise occurrence and work efficiency, if a trigger is externally applied to the oscilloscope 4 at the frequency of the power supply 6 and the detection signal is monitored by synchronizing the sweep speed, it is possible to detect noise from the surrounding environment. Even when regular noise is emitted, the sound pressure peak of the vibration sound emitted from the magnetic sensor is displayed at a fixed position on the oscilloscope 4, making it easy to judge.
【００１５】また、本実施例では電磁石５としては有芯
型の電磁石を用いた例で説明したが、交番磁界を発生し
得るものならこの限りではなく、図４に示すようなコイ
ルでもよい。また、音響カップラ７についても実施例で
は円筒状のものを用いたが、この形状についても同様で
、周囲の空気振動を遮断し目的とする被検体から発する
振動音を選択的に収音できるものであればどのような形
状でも良い。Further, in this embodiment, a cored type electromagnet is used as the electromagnet 5, but the electromagnet is not limited to this, and a coil as shown in FIG. 4 may be used as long as it can generate an alternating magnetic field. Furthermore, although a cylindrical acoustic coupler 7 was used in the embodiment, this shape is also the same, and is capable of blocking ambient air vibration and selectively collecting vibration sounds emitted from the target object. Any shape is acceptable.
【００１６】[0016]
【発明の効果】以上説明したように、本発明によれば製
造工程内などの周囲の騒音に妨害されることなく微弱な
異常音の発生も安定して検出することができ、永久磁石
とＭＲ素子との固定が異常な磁気センサを容易に選別す
ることができる。Effects of the Invention As explained above, according to the present invention, it is possible to stably detect the occurrence of weak abnormal sounds without being disturbed by surrounding noise such as in the manufacturing process. Magnetic sensors that are abnormally fixed to the element can be easily selected.
【図１】本発明の一実施例の磁気センサの検査装置の構
成を示すブロック図FIG. 1 is a block diagram showing the configuration of a magnetic sensor inspection device according to an embodiment of the present invention.
【図２】同実施例のオシロスコープ上の出力を示す波形
図[Figure 2] Waveform diagram showing the output on the oscilloscope of the same example
【図３】同実施例のマイクロフォンの出力を示す波形図
[Figure 3] Waveform diagram showing the output of the microphone of the same example
【図４】本発明の他の実施例の磁気センサの検査装置の
構成を示すブロック図FIG. 4 is a block diagram showing the configuration of a magnetic sensor inspection device according to another embodiment of the present invention.
１ 検出器 ２ 増幅器 ３ バンドパスフィルター ４ オシロスコープ ５ 電磁石 ６ 電源 ７ 音響カップラ ８ マイクロフォン 1 Detector 2 Amplifier 3 Bandpass filter 4 Oscilloscope 5 Electromagnet 6 Power supply 7 Acoustic coupler 8. Microphone
Claims (1)
、収音を行う音響カップラを備えこれに伴い出力信号を
出すマイクロフォンと、交番磁界を発生させる電源周波
数の逓倍値の何れかを中心周波数とし、マイクロフォン
からの出力信号を通過させるバンドパスフィルターと、
前記電源周波数で掃引周期を同期させバンドパスフィル
ターからの出力信号を入力とし信号の波形を表示するオ
シロスコープとを備えた磁気センサの検査装置。Claim 1: an alternating magnetic field generating means for generating an alternating magnetic field; a microphone for generating an output signal; and a bandpass filter that passes the output signal from the microphone.
A magnetic sensor inspection device comprising an oscilloscope that synchronizes the sweep cycle with the power supply frequency, inputs the output signal from the bandpass filter, and displays the signal waveform.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2401913A JPH04215030A (en) | 1990-12-13 | 1990-12-13 | Magnetic sensor inspecting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2401913A JPH04215030A (en) | 1990-12-13 | 1990-12-13 | Magnetic sensor inspecting device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04215030A true JPH04215030A (en) | 1992-08-05 |
Family
ID=18511731
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2401913A Pending JPH04215030A (en) | 1990-12-13 | 1990-12-13 | Magnetic sensor inspecting device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04215030A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007187565A (en) * | 2006-01-13 | 2007-07-26 | Toyota Motor Corp | Fixing degree inspection method and fixing degree inspection device of winding, and manufacturing method and manufacturing device of rotating electrical machine |
| CN105093148A (en) * | 2014-05-20 | 2015-11-25 | 中国人民解放军63973部队 | Time-domain calibration method for electromagnetic pulse magnetic-field probe |
| US9823308B2 (en) | 2011-04-29 | 2017-11-21 | Abb Schweiz Ag | Method for monitoring demagnetization |
-
1990
- 1990-12-13 JP JP2401913A patent/JPH04215030A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007187565A (en) * | 2006-01-13 | 2007-07-26 | Toyota Motor Corp | Fixing degree inspection method and fixing degree inspection device of winding, and manufacturing method and manufacturing device of rotating electrical machine |
| JP4725325B2 (en) * | 2006-01-13 | 2011-07-13 | トヨタ自動車株式会社 | Winding sticking degree inspection method, sticking degree inspection apparatus, and rotating electric machine manufacturing method and manufacturing apparatus |
| US9823308B2 (en) | 2011-04-29 | 2017-11-21 | Abb Schweiz Ag | Method for monitoring demagnetization |
| CN105093148A (en) * | 2014-05-20 | 2015-11-25 | 中国人民解放军63973部队 | Time-domain calibration method for electromagnetic pulse magnetic-field probe |
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