JPS61194313A - Supersonic signal detection of displacement detector - Google Patents
Supersonic signal detection of displacement detectorInfo
- Publication number
- JPS61194313A JPS61194313A JP3488185A JP3488185A JPS61194313A JP S61194313 A JPS61194313 A JP S61194313A JP 3488185 A JP3488185 A JP 3488185A JP 3488185 A JP3488185 A JP 3488185A JP S61194313 A JPS61194313 A JP S61194313A
- Authority
- JP
- Japan
- Prior art keywords
- magnetostrictive
- time
- magnetostrictive wire
- permanent magnet
- waveform
- 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
Landscapes
- Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は磁歪現象を用いて、物体の変位量あるいは機械
的変位などを検出する変位検出装置に関 ・するもので
ある。[Detailed Description of the Invention] Industrial Application Field The present invention relates to a displacement detection device that detects the amount of displacement or mechanical displacement of an object using magnetostriction.
従来技術とその問題点
従来、物体の機械的変位や層面などの変位を検出する変
位検出装置には種々のものがあり、その。Prior Art and its Problems Conventionally, there are various displacement detection devices that detect mechanical displacement of an object or displacement of a layer surface, etc.
中でも磁歪現象を応用した変位検出装置が特に線形性１
分解能に優れている。Among them, displacement detection devices that apply the magnetostrictive phenomenon have particularly high linearity 1.
Excellent resolution.
この種の変位検出装置として、例えば特開昭５５−６６
７１０号公報や特開昭５５−２３４２０公報に開示のも
のが知られているが、いずれの場合も永久磁石と磁歪線
との位置関係が少しでも変化すると、磁歪線には軸方向
に一様でない残留磁気が残り、この残留磁気のために永
久磁石の部位で生じる捩り歪取外の不要な信号が検出さ
れるという問題があった。As this type of displacement detection device, for example, Japanese Patent Laid-Open No. 55-66
710 and Japanese Unexamined Patent Publication No. 55-23420 are known, but in both cases, if the positional relationship between the permanent magnet and the magnetostrictive wire changes even slightly, the magnetostrictive wire will be uniformly axially There is a problem in that residual magnetism remains, and because of this residual magnetism, an unnecessary signal for removing torsional strain generated at the part of the permanent magnet is detected.
かかる問題を解決するため、本出願人は既に、永久磁石
の磁歪線に対する位置関係が変化しても高精度な検出が
できる変位検出装置を提案した（特願昭５９−２３４７
３５号）。この装置の原理を第１図〜第３図に示す。In order to solve this problem, the present applicant has already proposed a displacement detection device that can detect with high precision even if the positional relationship between the permanent magnet and the magnetostrictive line changes (Japanese Patent Application No. 59-2347).
No. 35). The principle of this device is shown in FIGS. 1 to 3.
図面において、１はＮｉなどからなる線状の磁歪線、２
は磁歪線１を取り囲み磁歪線ｌに沿って移動可能な永久
磁石であり、この永久磁石２は磁歪線１の軸方向に分極
されている。３は磁歪線１にパルス状の電流を供給する
パルス発生装置、４は磁歪線１の始端に装備された歪検
出装置である。In the drawing, 1 is a linear magnetostrictive wire made of Ni etc., 2 is a linear magnetostrictive wire made of Ni etc.
is a permanent magnet that surrounds the magnetostrictive wire 1 and is movable along the magnetostrictive wire 1, and this permanent magnet 2 is polarized in the axial direction of the magnetostrictive wire 1. 3 is a pulse generator that supplies a pulsed current to the magnetostrictive wire 1; 4 is a strain detection device installed at the starting end of the magnetostrictive wire 1;
パルス発生装置３によって磁歪線ｌに第２図Ａのような
幅の短い電流パルスを供給すると、磁歪線１には第３図
に示すような円周方向に磁場５が形成されるとともに、
永久磁石２が近接している磁歪線ｌの部位にのみ永久磁
石２による磁歪線ｌの軸方向の磁場６が形成され、いわ
ゆるビープマン効果によって磁歪線ｌの当該部位に捩り
歪が発生し、この模り歪が急激に生じるため、磁歪線ｌ
の両端に向かって捩り振動（超音波）が伝播する。When a short current pulse as shown in FIG. 2A is supplied to the magnetostrictive wire 1 by the pulse generator 3, a magnetic field 5 is formed in the magnetostrictive wire 1 in the circumferential direction as shown in FIG.
A magnetic field 6 in the axial direction of the magnetostrictive line l by the permanent magnet 2 is formed only in the part of the magnetostrictive line l that is close to the permanent magnet 2, and torsional strain is generated in the relevant part of the magnetostrictive line l due to the so-called Beepmann effect. Because the imitation strain occurs rapidly, the magnetostriction line l
Torsional vibrations (ultrasonic waves) propagate toward both ends of the
第１図のように、磁歪線１の始端に到達した捩り歪を歪
検出装置４で検出すれば、第２図Ｂのような波形が得ら
れ、その波形の適当な高さｈで第２図Ｃのようにパルス
信号を発生させれば、磁歪線１の始端から永久磁石２ま
での距離ｌを時間ｔの関数として次式で求めることがで
きる。As shown in FIG. 1, if the torsional strain that has reached the starting end of the magnetostrictive wire 1 is detected by the strain detection device 4, a waveform as shown in FIG. If a pulse signal is generated as shown in Figure C, the distance l from the starting end of the magnetostrictive line 1 to the permanent magnet 2 can be determined as a function of time t using the following equation.
１＝ｖ−を
上式において、■は候り歪の伝播速度であり、磁歪線ｌ
の横弾性係数をＧ、磁歪線ｌの密度をρとすると、
■＝丑フ７
で与えられる。1=v− in the above equation, ■ is the propagation speed of the distortion, and the magnetostrictive line l
Let G be the transverse elastic modulus of , and let ρ be the density of the magnetostrictive line l, then it is given by ① = Ushifu 7.
上記のようにして時間ｔを測定することにより永久磁石
２の変位を検出することができる。しかしながら、この
種の変位検出装置では、磁歪線１上を超音波が伝播する
ので、磁歪線ｌに外部から振動や衝撃などの外乱が加わ
った場合には、この外乱によって生じる音波が磁歪線１
を伝播し、第２図Ｂに示される本来必要な超音波信号に
対する雑音となる恐れがある。By measuring the time t as described above, the displacement of the permanent magnet 2 can be detected. However, in this type of displacement detection device, since ultrasonic waves propagate on the magnetostrictive wire 1, when external disturbances such as vibrations and shocks are applied to the magnetostrictive wire 1, the sound waves generated by this disturbance are transmitted to the magnetostrictive wire 1.
There is a possibility that the ultrasonic wave propagates and becomes noise to the originally necessary ultrasonic signal shown in FIG. 2B.
第４図はこの様子を示したものであり、第４図Ａは第２
図Ａと同様に磁歪線１に与えられる電流パルス、第４図
Ｂは本来測定すべき雑音のない波形、第４図Ｃは本来測
定すべき波形の上に外部からの振動や衝撃による雑音が
重畳された波形である。第４図Ｂでは波形の高さｈにな
るまでの時間ｔが測定され、第４図Ｃでは同じ高さｈに
よって時間ｔ′が測定されることになり、永久磁石２の
位置が同一であるにもかかわらず、異なった測定結果を
もたらすことになる。Figure 4 shows this situation, and Figure 4A shows the second
Similarly to Figure A, the current pulse is applied to the magnetostrictive wire 1. Figure 4B is a waveform with no noise that should originally be measured, and Figure 4C is a waveform that is originally supposed to be measured but has noise due to external vibrations or shocks. This is a superimposed waveform. In Fig. 4B, the time t until the waveform reaches the height h is measured, and in Fig. 4C, the time t' is measured at the same height h, and the position of the permanent magnet 2 is the same. Nevertheless, it will give different measurement results.
このような問題は、上記のように永久磁石１が磁歪線１
を取り囲んだ形状の場合に限らず、磁歪現象を応用した
変位検出装置には一般に起こる問題である。This problem arises when the permanent magnet 1 is exposed to the magnetostrictive wire 1 as described above.
This is a problem that generally occurs in displacement detection devices that apply the magnetostriction phenomenon, not only in cases where the magnetostriction phenomenon is applied.
発明の目的
本発明はかかる問題点に鑑みてなされたもので、その目
的は、磁歪現象を応用した変位検出装置を振動や衝撃な
どの外乱が多い環境で使用しても、誤差なく超音波信号
を検知できる超音波信号検知方法を提供することにある
。Purpose of the Invention The present invention has been made in view of the above-mentioned problems.The purpose of the present invention is to detect ultrasonic signals without error even when a displacement detection device that applies the magnetostrictive phenomenon is used in an environment with many disturbances such as vibrations and shocks. An object of the present invention is to provide an ultrasonic signal detection method capable of detecting.
発明の構成
上記目的を達成するために、本発明は、特定部位で検出
された超音波信号を微分し、磁歪によって生じた超音波
の波形の頂点で超音波の伝播時間を計測するものである
。Structure of the Invention In order to achieve the above object, the present invention differentiates an ultrasonic signal detected at a specific region and measures the propagation time of the ultrasonic wave at the peak of the ultrasonic waveform generated by magnetostriction. .
すなわち、本来測定すべき超音波９波形の頂点は、たと
え雑音が重畳されても時間軸に対する位置は一定してお
り、したがってこの波形の頂点で超音波の伝播時間を計
測すれば、誤差なく超音波信号を検知できる。In other words, the vertices of the nine ultrasonic waveforms that should originally be measured remain at a constant position with respect to the time axis even if noise is superimposed on them. Therefore, if the propagation time of the ultrasonic waves is measured at the apex of this waveform, the ultrasonic waves will be measured without error. Can detect sound wave signals.
実施例の説明
第５図は本発明を利用した装置の第１実施例を示し、第
６図は第５図に示した回路の各部の電圧波形を示す。DESCRIPTION OF EMBODIMENTS FIG. 5 shows a first embodiment of an apparatus using the present invention, and FIG. 6 shows voltage waveforms at various parts of the circuit shown in FIG.
第６図Ａはパルス発生装置３によって磁歪線ｌに与えら
れる電流パルスであり、該パルスが与えられてから適当
な時間後、第６図Ｂの如き波形が歪検出装置４で検出さ
れる。この第６図Ｂの波形は磁歪線１に振動や衝撃など
の外乱が加わっていない状態におけるものである。FIG. 6A shows a current pulse applied to the magnetostrictive wire 1 by the pulse generator 3, and after an appropriate period of time after the pulse is applied, a waveform as shown in FIG. 6B is detected by the strain detection device 4. The waveform shown in FIG. 6B is obtained when no disturbance such as vibration or shock is applied to the magnetostrictive wire 1.
第６図Ｃは磁歪線１に加わる外乱のみを検出した波形で
あり、例えば磁歪線１に永久磁石２を挿入していない状
態で磁歪線ｌに外乱が加わり、これを歪検出装置４で検
出したときの波形を示したものである。実際には、第６
図ＢとＣとが合成された第６図りのような波形が歪検出
装置４で検出される。FIG. 6C shows a waveform in which only the disturbance applied to the magnetostrictive wire 1 is detected. For example, when the permanent magnet 2 is not inserted into the magnetostrictive wire 1, a disturbance is applied to the magnetostrictive wire 1, and this is detected by the strain detection device 4. This shows the waveform when In fact, the 6th
The distortion detection device 4 detects a waveform as shown in the sixth figure, which is a combination of figures B and C.
７は高域通過フィルタであり、磁歪線１上の永久磁石２
の部位で発生する超音波の周波数（例えば１００Ｋ）ｌ
ｚ）近傍以上の信号のみ通過させ、これ以下の周波数信
号をカットするものである。歪検出装置４から高域通過
フィルタフに伝えられた信号は、高域通過フィルタ７で
低域がカントされ、第６図Ｅのように出力される。7 is a high-pass filter, and a permanent magnet 2 on the magnetostrictive wire 1
The frequency of the ultrasound generated at the site (e.g. 100K)
z) Only signals of frequencies above the vicinity are allowed to pass, and signals of frequencies below this are cut. The signal transmitted from the distortion detection device 4 to the high-pass filter has its low frequency canted by the high-pass filter 7, and is output as shown in FIG. 6E.
８は電圧コンパレータであり、正入力に加えられた高域
通過フィルタフの出力電圧が負入力に加えられた電圧（
この実施例の場合にはＶ）よりも高いときに、第６図Ｆ
のように出力される。高域通過フィルタフの出力Ｅは、
また同時にコンデンサ１０と抵抗１１とで構成される微
分回路９にも伝えられ、微分された波形は第６図Ｇのま
うになる。8 is a voltage comparator, in which the output voltage of the high-pass filter applied to the positive input is equal to the voltage applied to the negative input (
In this embodiment, when higher than V), FIG.
The output is as follows. The output E of the high-pass filter is
At the same time, the signal is also transmitted to a differentiating circuit 9 composed of a capacitor 10 and a resistor 11, and the differentiated waveform becomes as shown in FIG. 6G.
１２は電圧コンパレータであり、負入力に加えられた微
分回路９の出力電圧が正入力に加えられている電圧（こ
の実施例の場合には０）よりも低いときに出力Ｈを発生
し、この様子を示したのが第６図Ｈである。12 is a voltage comparator, which generates an output H when the output voltage of the differentiating circuit 9 applied to the negative input is lower than the voltage applied to the positive input (0 in this embodiment); Figure 6H shows the situation.
コンパレータ８，１２の出力Ｆ、 ＨはＡＮＤ素子１３
に印加されているので、信号Ｆ、 Ｈが同時にＯＮのと
きにのみ第６図■に示すようにパルス信号が出力される
。パルス信号Ｉの立ち上がり時刻は、磁歪線ｌ上の永久
磁石２の部位で発生した超音波の波形の頂点が歪検出装
置４で検出される時刻と一致する。Outputs F and H of comparators 8 and 12 are AND element 13
Therefore, a pulse signal is output as shown in FIG. 6 only when signals F and H are simultaneously ON. The rising time of the pulse signal I coincides with the time when the peak of the waveform of the ultrasonic wave generated at the part of the permanent magnet 2 on the magnetostrictive line l is detected by the strain detection device 4.
このように、電流パルスＡが発生した時刻からパルス信
号Ｉの立ち上がり時刻までをｔのように測定すれば、磁
歪線１を伝播してくる超音波の波形の頂点の到達時刻を
正確に知ることができる。In this way, by measuring the time from the time when the current pulse A is generated to the rise time of the pulse signal I as t, it is possible to accurately know the arrival time of the peak of the waveform of the ultrasonic wave propagating through the magnetostrictive wire 1. Can be done.
第７図、第８図は本発明の第２実施例を示し、第５図の
場合と同様に、歪検出装置４の出力信号りは高域通過フ
ィルタフに供給され、出力信号Ｅを得る。出力信号Ｅは
演算増幅器１４、抵抗１５．１６からなる回路に伝えら
れ、この回路は第７図に示すようにＶ。でバイアスされ
ているため、第８図Ｅに示すようにＶ。よりも高い信号
のみ増幅され、また例えば演算増幅器１４として片電源
で動作する演算増幅器を使用すれば、ｖｏよりも低い信
号は０にクランプされて、第８図Ｊのように波形の頂点
近傍のみが増幅された信号が得られることになる。7 and 8 show a second embodiment of the present invention, in which, as in the case of FIG. 5, the output signal of the distortion detection device 4 is supplied to a high-pass filter to obtain an output signal E. The output signal E is transmitted to a circuit consisting of an operational amplifier 14 and resistors 15 and 16, which is connected to a voltage V as shown in FIG. V as shown in FIG. 8E. Only signals higher than vo are amplified, and if an operational amplifier operating from a single power source is used as the operational amplifier 14, signals lower than vo are clamped to 0, and only the signal near the peak of the waveform is amplified, as shown in FIG. 8J. This results in a signal that has been amplified.
上記Ｊ信号を第５図と同様なコンデンサ１０と抵抗１１
とで構成された微分回路９に印加すれば、微分出力信号
が第８図にのように得られ、第８図Ｅの波形の頂点と一
致する時刻にゼロをクロスする信号が得られる。微分出
力信号には電圧コンパレータ１２に伝えられ、既に第５
図の例で述べたように、コンパレータ１２の負入力の信
号がゼロ以下の場合にコンパレータ１２がＯＮになるた
め、第８図りのような出力信号が得られることになる。The above J signal is connected to a capacitor 10 and a resistor 11 similar to those shown in FIG.
When the voltage is applied to the differentiating circuit 9 composed of the following, a differential output signal is obtained as shown in FIG. 8, and a signal that crosses zero at the time coinciding with the peak of the waveform shown in FIG. 8E is obtained. The differential output signal is transmitted to the voltage comparator 12 and has already been applied to the fifth
As described in the example shown in the figure, when the signal at the negative input of the comparator 12 is less than zero, the comparator 12 is turned on, so that an output signal as shown in the eighth figure is obtained.
第８図りの信号の立ち上がり時刻は第８図Ｅの波形の頂
点と一致するので、時間ｔを正確に測定することができ
る。Since the rising time of the signal in Figure 8 coincides with the peak of the waveform in Figure 8E, time t can be measured accurately.
第９図は本発明の第３実施例を示す。第１．第２実施例
では、磁歪線ｌに加えられた低域の雑音を電気的に除去
するために高域通過フィルタ７を使用したが、この実施
例では磁歪線１への外乱の伝達を機械的に防止したもの
である。FIG. 9 shows a third embodiment of the invention. 1st. In the second embodiment, the high-pass filter 7 was used to electrically remove the low-frequency noise added to the magnetostrictive wire 1, but in this embodiment, the transmission of disturbance to the magnetostrictive wire 1 is mechanically performed. This was to prevent this.
図面において、磁歪線１は非磁性で導電性の中筒１７の
中に挿入され、この中筒１７の両端部内部には中心を磁
歪線１が貫通するゴムなどの弾性体１８が組み込まれて
いる。そして、磁歪線１に張力を持たせた後、中筒１７
の両端部を圧縮して絞り部１９を形成することにより、
磁歪線ｌと弾性体１８とを同時に押圧し、磁歪線１は中
筒１７の中に装備される。In the drawing, the magnetostrictive wire 1 is inserted into a non-magnetic and conductive middle cylinder 17, and an elastic body 18 such as rubber, through which the magnetostrictive wire 1 passes through the center, is installed inside both ends of the middle cylinder 17. There is. After applying tension to the magnetostrictive wire 1, the middle cylinder 17
By compressing both ends of to form a constricted part 19,
The magnetostrictive wire 1 and the elastic body 18 are pressed at the same time, and the magnetostrictive wire 1 is installed in the middle tube 17.
上記絞り部１９では弾性体１８が磁歪線ｌの外周に密着
するので、磁歪線１の両端まで伝播した超音波が弾性体
１８で効果的に吸収、される。したがって、第２図Ｂで
示すような永久磁石２で生じた捩り歪による超音波のみ
を、中筒１７に形成した開口部３５を経て歪検出装置４
で検出することが可能となる。In the aperture section 19, the elastic body 18 is in close contact with the outer periphery of the magnetostrictive wire 1, so that the ultrasonic waves propagated to both ends of the magnetostrictive wire 1 are effectively absorbed by the elastic body 18. Therefore, only the ultrasonic waves caused by the torsional strain generated in the permanent magnet 2 as shown in FIG.
It becomes possible to detect the
磁歪線１の始端は導線２２に接続され、後端は導線２０
によって中筒１７の右端に電気的に接続され、さらに中
筒１７の左端は導線２１に接続されているため、多心ケ
ーブル２５より供給される電流パルスが磁歪線１に流れ
る。なお、この実施例では、中筒１７を導電体の一部と
して使用したが、中筒１７が非導電性材料で構成されて
いる場合には、別の導線（図示せず）を磁歪線１の後端
と導線２１との間に設ければ、同様の目的を達する。The starting end of the magnetostrictive wire 1 is connected to the conducting wire 22, and the rear end is connected to the conducting wire 20.
Since the right end of the middle tube 17 is electrically connected to the right end of the middle tube 17, and the left end of the middle tube 17 is connected to the conducting wire 21, a current pulse supplied from the multicore cable 25 flows through the magnetostrictive wire 1. In this embodiment, the middle tube 17 was used as a part of the conductor, but if the middle tube 17 is made of a non-conductive material, another conducting wire (not shown) may be connected to the magnetostrictive wire 1. If it is provided between the rear end of the conductor 21 and the conductor 21, the same purpose can be achieved.
磁歪線１を装備した中筒１７は非磁性の外筒２７の中に
挿入され、この外筒２７と中筒１７との間に形成される
環状空間に、例えばスポンジなどからなる振動吸収材３
３が配置されている。この振動吸収材３３は、外筒２７
や、外１ｉｉ２７に溶接あるいは他の機械的方法で接合
固定されたケース３０などに作用する外部からの機械的
な振動や衝撃を吸収、減衰させ、不必要な外乱が歪検出
装置４で検出され得ないようにしている。The inner tube 17 equipped with the magnetostrictive wire 1 is inserted into a non-magnetic outer tube 27, and a vibration absorbing material 3 made of, for example, sponge is inserted into the annular space formed between the outer tube 27 and the middle tube 17.
3 is placed. This vibration absorbing material 33 is
It absorbs and attenuates mechanical vibrations and shocks from the outside that act on the case 30, which is fixed to the outside 1ii27 by welding or other mechanical methods, and prevents unnecessary disturbances from being detected by the strain detection device 4. I try not to get it.
外筒２７の右端にはエンドキャップ２８が圧入もしくは
他の機械的方法で密封固定されており、例えば外筒２７
が液中にあっても、液体が外筒２７の内部に浸入するこ
とな（、永久磁石２の位置を検出することが可能となる
。An end cap 28 is hermetically fixed to the right end of the outer cylinder 27 by press fitting or other mechanical method.
Even if the permanent magnet 2 is in the liquid, the liquid will not enter the inside of the outer cylinder 27 (and the position of the permanent magnet 2 can be detected).
ケース３０の左端にはケースカバー２９が挿入固定され
、このケースカバー２９を貫通して多心ケーブル２５が
ケース３０内に導入されている。A case cover 29 is inserted and fixed at the left end of the case 30, and the multi-core cable 25 is introduced into the case 30 through the case cover 29.
多心ケーブル２５は磁歪線ｌへの電流パルスの供給を行
うとともに、歪検出装置４の検出信号を導線２３．２４
を介して取り出すことができる。また、多心ケーブル２
５としてシールド線を使用すれば、シールド導線２６を
ケース３０の内面に電気的に接続し、ケース３０および
外筒２７を磁歪線１および歪検出装置４の電気的シール
ドとして使用することもできる。The multicore cable 25 supplies current pulses to the magnetostrictive wire l, and also transmits the detection signal of the strain detection device 4 to the conductor wires 23 and 24.
It can be taken out via. In addition, multi-core cable 2
If a shielded wire is used as the magnetostrictive wire 5, the shielded wire 26 can be electrically connected to the inner surface of the case 30, and the case 30 and the outer tube 27 can be used as electrical shields for the magnetostrictive wire 1 and the strain detection device 4.
上記構成の変位検出装置は、変位を検出すべき機械など
の固定部３４にケース３０のネジ部３１を挿入してナフ
ト３２で締め付は固定し、機械などの可動部（図示せず
）に永久磁石２を固定すれば容易に設置でき、機械など
の可動部の変位を既に第５図〜第８図で述べた方法によ
って検出することができる。In the displacement detection device having the above configuration, the threaded part 31 of the case 30 is inserted into the fixed part 34 of the machine etc. whose displacement is to be detected, and the screw part 31 of the case 30 is fixed by the napht 32. If the permanent magnet 2 is fixed, it can be easily installed, and the displacement of a movable part of a machine or the like can be detected by the method already described in FIGS. 5 to 8.
上記のように、この実施例では外筒２７と中筒１７との
間に振動吸収材３３を配置することにより、外部からの
機械的な振動や衝撃を吸収、減衰させることができるた
め、高域通過フィルタフなどの電気的な外乱除去手段を
省略することも可能である。As described above, in this embodiment, by arranging the vibration absorbing material 33 between the outer cylinder 27 and the middle cylinder 17, mechanical vibrations and shocks from the outside can be absorbed and damped. It is also possible to omit electrical disturbance removal means such as a bandpass filter.
なお、上記のような機械的な振動吸収材３３を第１．第
２実施例に示す高域通過フィルタ７と併用すれば、不必
要な外乱をより効果的に除去することができる。Note that the mechanical vibration absorbing material 33 as described above is used in the first. If used together with the high-pass filter 7 shown in the second embodiment, unnecessary disturbances can be removed more effectively.
また、本発明の超音波信号検知方法は、上記各実施例の
ように磁歪線に電流パルスを流し、永久磁石の近接する
部位で超音波を発生させる場合に限らず、磁歪線に超音
波を流し、永久磁石の近接する部位で超音波を反射させ
ることにより、永久磁石の変位を検出する場合にも同様
に応用することができるものである。Furthermore, the ultrasonic signal detection method of the present invention is not limited to the case where a current pulse is passed through a magnetostrictive wire to generate an ultrasonic wave at a portion adjacent to a permanent magnet as in each of the above embodiments. It can be similarly applied to the case of detecting the displacement of a permanent magnet by reflecting the ultrasonic wave at a portion adjacent to the permanent magnet.
発明の効果
以上の説明で明らかなように、本発明によれば変位検出
装置を振動や衝撃の多い環境で使用しても、本来必要な
超音波の波形の頂点を時間測定の基準としているため、
常に正確な永久磁石の位置を時間の関数として知ること
ができる。Effects of the Invention As is clear from the above explanation, according to the present invention, even when the displacement detection device is used in an environment with many vibrations and shocks, the originally necessary peak of the ultrasonic waveform is used as the reference for time measurement. ,
It is possible to always know the exact position of the permanent magnet as a function of time.
第１図は本発明の前提となる変位検出装置の一例の概略
構成図、第２図は検出方法の一例を示す波形図、第３図
は磁歪線に生じる磁場の方向を示す斜視図、第４図は外
乱が加わった場合の超音波の波形図、第５図以下は本発
明の実施例を示し、第５図は本発明方法を使用した装置
の第１実施例の構成図、第６図は第５図に示す回路の各
部の電圧波形図、第７図は本発明の第２実施例の回路図
、第８図は第７図に示す回路の各部の電圧波形図、第９
図は本発明方法を使用した変位検出装置の第３実施例の
断面図である。
１・・・磁歪線、２・・・永久磁石、３・・・パルス発
生装置、４・・・歪検出装置、７・・・高域通過フィル
タ、９・・・微分回路、３３・・・振動吸収材。
出 願 人 三京貿易株式会社
代 理 人 弁理士 筒井 秀隆
第１図
第２図
第３図
第４図
第５図
第６図
第７図FIG. 1 is a schematic configuration diagram of an example of a displacement detection device that is the premise of the present invention, FIG. 2 is a waveform diagram showing an example of a detection method, FIG. 3 is a perspective view showing the direction of the magnetic field generated in the magnetostrictive wire, and FIG. Fig. 4 is a waveform diagram of ultrasonic waves when disturbance is applied, Fig. 5 and the following show embodiments of the present invention, Fig. 5 is a block diagram of the first embodiment of the apparatus using the method of the present invention, and Fig. 6 The figure is a voltage waveform diagram of each part of the circuit shown in FIG. 5, FIG. 7 is a circuit diagram of the second embodiment of the present invention, FIG. 8 is a voltage waveform diagram of each part of the circuit shown in FIG.
The figure is a sectional view of a third embodiment of a displacement detection device using the method of the present invention. DESCRIPTION OF SYMBOLS 1... Magnetostrictive wire, 2... Permanent magnet, 3... Pulse generator, 4... Strain detection device, 7... High pass filter, 9... Differential circuit, 33... Vibration absorber. Applicant Sankyo Boeki Co., Ltd. Agent Patent Attorney Hidetaka Tsutsui Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7
Claims (1)
磁歪線に沿って移動可能な永久磁石の近接する磁歪線の
部位で超音波を発生あるいは反射させ、磁歪線の特定部
位までの超音波の伝播時間を計測することにより、永久
磁石に与えられる機械的変位を検出する装置において、
上記特定部位で検出された超音波信号を微分し、磁歪に
よって生じた超音波の波形の頂点で超音波の伝播時間を
計測することを特徴とする超音波信号検知方法。(1) Apply a current pulse or ultrasonic signal to the magnetostrictive wire,
A machine that generates or reflects ultrasonic waves at adjacent magnetostrictive lines of a permanent magnet that can move along the magnetostrictive lines, and measures the propagation time of the ultrasonic waves to a specific part of the magnetostrictive lines. In a device for detecting target displacement,
An ultrasonic signal detection method characterized by differentiating the ultrasonic signal detected at the specific region and measuring the propagation time of the ultrasonic wave at the peak of the waveform of the ultrasonic wave generated by magnetostriction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3488185A JPS61194313A (en) | 1985-02-23 | 1985-02-23 | Supersonic signal detection of displacement detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3488185A JPS61194313A (en) | 1985-02-23 | 1985-02-23 | Supersonic signal detection of displacement detector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS61194313A true JPS61194313A (en) | 1986-08-28 |
Family
ID=12426482
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3488185A Pending JPS61194313A (en) | 1985-02-23 | 1985-02-23 | Supersonic signal detection of displacement detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61194313A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5428597A (en) * | 1989-10-30 | 1995-06-27 | Matsushita Electric Industrial Co., Ltd. | Multi-layered optical disk with track and layer identification |
| DE19948892A1 (en) * | 1999-10-11 | 2001-05-17 | Asm Automation Sensorik Messte | Pulse detector and method for the detection of sinusoidal pulses |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4966287A (en) * | 1972-10-31 | 1974-06-27 | ||
| JPS5523420A (en) * | 1978-08-01 | 1980-02-19 | Yokogawa Hokushin Electric Corp | Displacement position detector |
| JPS5566710A (en) * | 1978-11-15 | 1980-05-20 | Yokogawa Hokushin Electric Corp | Displacement detector |
-
1985
- 1985-02-23 JP JP3488185A patent/JPS61194313A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4966287A (en) * | 1972-10-31 | 1974-06-27 | ||
| JPS5523420A (en) * | 1978-08-01 | 1980-02-19 | Yokogawa Hokushin Electric Corp | Displacement position detector |
| JPS5566710A (en) * | 1978-11-15 | 1980-05-20 | Yokogawa Hokushin Electric Corp | Displacement detector |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5428597A (en) * | 1989-10-30 | 1995-06-27 | Matsushita Electric Industrial Co., Ltd. | Multi-layered optical disk with track and layer identification |
| DE19948892A1 (en) * | 1999-10-11 | 2001-05-17 | Asm Automation Sensorik Messte | Pulse detector and method for the detection of sinusoidal pulses |
| DE19948892C2 (en) * | 1999-10-11 | 2002-07-18 | Asm Automation Sensorik Messte | Pulse detector and method for the detection of sinusoidal pulses |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3898555A (en) | Linear distance measuring device using a moveable magnet interacting with a sonic waveguide | |
| US4678993A (en) | Distance measuring device operating with torsional ultrasonic waves detected without mode conversion | |
| US5804961A (en) | Magnetostrictive waveguide position measurement apparatus using piezoelectric sensor | |
| CN117147685A (en) | Electromagnetic acoustic transducer (EMAT) for corrosion mapping | |
| US5680041A (en) | Magnetostrictive position measurement apparatus with anti-reflection waveguide terminals | |
| JPS61112923A (en) | Apparatus for detecting displacement | |
| JPS61194313A (en) | Supersonic signal detection of displacement detector | |
| US6404183B1 (en) | Magnetostrictive position measuring device with high measurement precision | |
| US5714881A (en) | Position measurement apparatus using wire waveguide in shock resistant suspension | |
| Yanqing et al. | Study on ultrasonic generation mechanism of partial discharge | |
| JPH01272918A (en) | Strain detecting device for displacement detector | |
| JPH0346763B2 (en) | ||
| JPH02124425A (en) | Displacement detector | |
| JP3799415B2 (en) | Magnetostrictive displacement detector | |
| JPS63217224A (en) | Displacement detecting device | |
| JPH067305Y2 (en) | Displacement detection device | |
| SU1147979A1 (en) | Acoustic emission calibrated signal simulator | |
| Takahashi et al. | Cavitation noise measurement using a fiber‐optic hydrophone | |
| JP2001041989A (en) | Space charge measuring device | |
| JP2007132734A (en) | Non-contact type potential measuring method of rotator, and its device | |
| SU777580A1 (en) | Impact acceleration measuring device | |
| RU1784095C (en) | Piezoelectric converter for reception of signals of acoustic emission | |
| SU1396071A1 (en) | Current pulse measuring device | |
| JPH04140670A (en) | Cable insulator space electric charge distribution measuring device | |
| SU1422161A1 (en) | Device for calibrating impact-type accelerometers |