JPS6156450B2 - - Google Patents
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- Publication number
- JPS6156450B2 JPS6156450B2 JP3531577A JP3531577A JPS6156450B2 JP S6156450 B2 JPS6156450 B2 JP S6156450B2 JP 3531577 A JP3531577 A JP 3531577A JP 3531577 A JP3531577 A JP 3531577A JP S6156450 B2 JPS6156450 B2 JP S6156450B2
- Authority
- JP
- Japan
- Prior art keywords
- acoustic wave
- surface acoustic
- signal
- circuit
- transducer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000010897 surface acoustic wave method Methods 0.000 claims description 42
- 230000010355 oscillation Effects 0.000 claims description 29
- 238000007493 shaping process Methods 0.000 claims description 8
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 4
- 230000001902 propagating effect Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 17
- 238000000034 method Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- 230000001934 delay Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は表面応力の測定装置に係り特に圧延ロ
ール等の大形構造物の表面応力を非破壊的に測定
するに好適な、表面弾性波の伝播速度から表面応
力を測定する装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a surface stress measurement device, and in particular to a surface acoustic wave measurement device suitable for non-destructively measuring the surface stress of large structures such as rolling rolls. This invention relates to a device for measuring surface stress from propagation velocity.
従来、表面応力の測定に用いられる装置として
は、Ｘ線を使用したものや、歪ゲージを使用した
ものがある。しかし前者は表面下数μｍまでの応
力は測定できるが、より深い部分の応力は測定で
きない。また後者は、歪ゲージを張つた部分の応
力開放を行なうことによつて生ずる歪の量と方向
から、その部分の応力を測定するものであるが、
応力開放の際に被測定物を切断しなければなら
ず、非破壊的な測定を要する場合に適用できない
などの欠点があつた。
Conventionally, devices used for measuring surface stress include those using X-rays and those using strain gauges. However, although the former method can measure stress up to several micrometers below the surface, it cannot measure stress in deeper parts. In addition, the latter method measures the stress in a part where a strain gauge is stretched, based on the amount and direction of the strain produced by releasing the stress in that part.
This method has drawbacks such as the fact that the object to be measured must be cut when stress is released, making it inapplicable to cases where non-destructive measurement is required.
一方従来被検体の内部応力を測定するため、被
検体内部に超音波を伝播させ、その伝播状況から
被検体の内部応力分布等を測定する方法も提案さ
れているが、該方法を表面応力の測定に用いたも
のは従来なかつた。 On the other hand, in order to measure the internal stress of a specimen, a method has been proposed in which ultrasonic waves are propagated inside the specimen and the internal stress distribution of the specimen is measured from the propagation situation. There was no one that had been used for measurements before.
本発明は前記従来の欠点を解消するべくなされ
たもので、物体の表面から数mm程度までの深さ
の、前記物体の任意の部分の表面に沿つた方向の
応力を、非破壊的に簡単かつ高精度で確実に測定
することのできる表面応力の測定装置を得ること
を目的とする。
The present invention was made in order to eliminate the above-mentioned conventional drawbacks, and it is possible to easily and non-destructively reduce stress in the direction along the surface of any part of the object up to a depth of several millimeters from the surface of the object. Another object of the present invention is to obtain a surface stress measuring device that can measure surface stress reliably with high precision.
本発明の特徴は、被検体の表面に設置され、該
被検体表面に表面弾性波を伝播させる第１の表面
弾性波用トランスデユーサと、このトランスデユ
ーサが設置されている被検体の同一表面上に設置
され、被検体の表面を伝播する前記表面弾性波を
受波する第２の表面弾性波用トランスデユーサ
と、前記第１及び第２の表面弾性波用トランスデ
ユーサをそれらの相対距離が変化しないように結
合する剛体の結合材と、前記第１トランスデユー
サに表面弾性波を励起するための信号を印加する
発振器と、前記第２のトランスデユーサに受波さ
れる表面弾性波信号を検出する受信器と、前記受
信器で検出された受信信号の波形整形回路と、発
振信号を一定時間遅延させるゲート回路と、前記
波形整形回路及びゲート回路の出力が一致した時
出力を出すAND回路と、該AND回路出力と発振
信号との時間差に応じた電圧を出力する時間差信
号発生回路と、該時間差信号発生回路の出力電圧
により時間差がゼロとなるような周期のトリガー
信号を発振器に与える電圧制御発振器と、発振信
号の周期を測定するカウンタとを備え、他励振さ
れた発振周期を求めることにより、前記発信器に
発生したパルス信号と、前記受信器で検出された
信号との時間間隔を測定して前記第１及び第２の
トランスデユーサ間の表面弾性波伝播速度を得る
伝播速度測定手段とを備え、前記被検体表面を伝
播する表面弾性波の伝播速度から該被検体表面に
沿う応力を測定することにある。
The present invention is characterized by a first surface acoustic wave transducer that is installed on the surface of a subject and that propagates surface acoustic waves to the surface of the subject, and a a second surface acoustic wave transducer that is installed on the surface and receives the surface acoustic wave propagating on the surface of the object; and the first and second surface acoustic wave transducers. a rigid coupling material that is coupled so that the relative distance does not change; an oscillator that applies a signal for exciting a surface acoustic wave to the first transducer; and a surface that is received by the second transducer. A receiver that detects an elastic wave signal, a waveform shaping circuit for the received signal detected by the receiver, a gate circuit that delays the oscillation signal for a certain period of time, and an output when the outputs of the waveform shaping circuit and the gate circuit match. an AND circuit that outputs an oscillation signal, a time difference signal generation circuit that outputs a voltage according to the time difference between the output of the AND circuit and the oscillation signal, and a trigger signal with a period such that the time difference becomes zero due to the output voltage of the time difference signal generation circuit. It is equipped with a voltage-controlled oscillator that feeds the oscillator and a counter that measures the period of the oscillation signal, and by determining the separately excited oscillation period, the pulse signal generated in the oscillator and the signal detected by the receiver can be combined. a propagation velocity measuring means for measuring a time interval between the first and second transducers to obtain the surface acoustic wave propagation velocity between the first and second transducers, Its purpose is to measure stress along the surface of a specimen.
表面弾性波は、その波長程度の深さまでの表面
に集中して伝播し、しかも、応力によつて、その
伝播速度が変化する。応力１Kg／mm３当りの表面
弾性波の速度の変化は、応力の加わらない状態
（大気圧下）に比べて、10-4程度の割合である
が、この関係は、100ｇ／mm2あるいは10ｇ／mm2と
いう小さな応力変化に対しても、それぞれ10-5、
及び10-6程度とよい直線性を示す。本発明は、こ
の表面弾性波の応力変化特性を利用して、表面応
力を測定するようにしたものである。
Surface acoustic waves propagate concentrated on the surface to a depth of about the same wavelength, and their propagation speed changes depending on stress. The change in the velocity of surface acoustic waves per 1 kg/mm 3 of stress is approximately 10 -4 compared to the state where no stress is applied (under atmospheric pressure), but this relationship holds true for 100 g/mm 2 or 10 g Even for a small stress change of /mm 2 , 10 -5 and
and exhibits good linearity of about 10 -6 . The present invention measures surface stress by utilizing the stress change characteristics of surface acoustic waves.
以下本発明に係る表面応力の測定装置の具体的
な実施例を図面を参照して詳細に説明する。第１
図は本発明の原理説明図を示すもので、被検体１
０の表面に対向するよう固定される第１及び第２
の表面弾性波用トランスデユーサ１２，１４と、
該第１のトランスデユーサ１２に表面弾性波１５
を励起するためのパルス信号１６を印加する発振
器１８と、前記第２のトランスデユーサ１４に入
力する表面弾性波信号１９を検出する受信器２０
と、前記第１及び第２のトランスデユーサ間の表
面弾性波伝播時間Ｔを測定する時間差測定器２２
とからなる。 Hereinafter, specific embodiments of the surface stress measuring device according to the present invention will be described in detail with reference to the drawings. 1st
The figure shows an explanatory diagram of the principle of the present invention.
first and second fixed to face the surface of
surface acoustic wave transducers 12 and 14;
A surface acoustic wave 15 is applied to the first transducer 12.
an oscillator 18 that applies a pulse signal 16 to excite the transducer 14; and a receiver 20 that detects the surface acoustic wave signal 19 input to the second transducer 14.
and a time difference measuring device 22 for measuring the surface acoustic wave propagation time T between the first and second transducers.
It consists of
前記第１及び第２の表面弾性波用トランスデユ
ーサ１２，１４は第２図に示すごとく、相対距離
が10-4程度の安定度を有する剛性からなる結合材
２６により互いに固定されている。２７は超音波
振動子、２８はアクリル、プラスチツク等の超音
波伝播媒質である。この第１及び第２の表面弾性
波用トランスデユーサは、油、グリセリン等の接
触媒質を介して被検体１０の表面に空間ができな
いよう固定される。 As shown in FIG. 2, the first and second surface acoustic wave transducers 12 and 14 are fixed to each other by a rigid bonding material 26 having a relative distance of about 10 -4 stability. 27 is an ultrasonic transducer, and 28 is an ultrasonic propagation medium such as acrylic or plastic. The first and second surface acoustic wave transducers are fixed to the surface of the subject 10 via a couplant such as oil or glycerin so that no space is left.
本装置を使用するには下記のようにする。すな
わち発振器１８に外部からトリガー信号を与え、
第３図に示すようなパルス信号１６を発生し、送
波用の表面弾性波用トランスデユーサ１２から、
被検体表面１０に表面弾性波１５を伝播させる。
するとこの表面弾性波は両トランスデユーサ間を
伝播時間Ｔで伝播し、受波用の表面弾性波トラン
スデユーサ１４で検出される。検出された表面弾
性波信号１９は、受信器２０で増幅され、時間差
測定器２２に出力される。 To use this device, proceed as follows. That is, a trigger signal is given to the oscillator 18 from the outside,
A pulse signal 16 as shown in FIG. 3 is generated from the surface acoustic wave transducer 12 for wave transmission.
A surface acoustic wave 15 is propagated on the surface 10 of the object.
Then, this surface acoustic wave propagates between both transducers for a propagation time T, and is detected by the receiving surface acoustic wave transducer 14. The detected surface acoustic wave signal 19 is amplified by a receiver 20 and output to a time difference measuring device 22 .
両トランスデユーサ間の距離をＬ、表面弾性波
音速をｖRとすると、前記伝播時間Ｔは、
Ｔ＝Ｌ／ｖR ……(1)
である。被検体１０の表面に応力σが生じた時の
表面弾性波の音速ｖR Sは、応力による音速の減少
係数をγと定義した場合、
ｖR S＝ＶR（１−γσ） ……(2)
のように変化することになる。応力が生じた時
の、前記伝播時間の変化をΔＴ、応力ゼロの時の
前記伝播時間をT0とすれば、前記(1)，(2)式から
次の近似式が成り立つ。 When the distance between both transducers is L and the surface acoustic wave sound velocity is v R , the propagation time T is as follows: T=L/v R (1). The sound velocity v R S of the surface acoustic wave when stress σ is generated on the surface of the object 10 is defined as v R S = V R (1−γσ) ...( 2) will change as follows. If the change in the propagation time when stress occurs is ΔT, and the propagation time when stress is zero is T 0 , then the following approximate equation holds true from equations (1) and (2) above.
σ＝ΔＴ／γT0 ……(3)
この式から、応力による音速の減少係数γを、
荷重試験等によつて実験的に求めて定めておけ
ば、伝播時間の変化率ΔＴ／T0の測定値から、
応力が求まる。また、T0が不明の場合でも、場
所による伝播時間の違いから、ΔＴの分布即ち応
力分布を測定できる。 σ=ΔT/γT 0 ...(3) From this formula, the reduction coefficient γ of the sound speed due to stress is
If determined experimentally through load tests, etc., then from the measured value of the rate of change in propagation time ΔT/T 0 ,
Find the stress. Furthermore, even if T 0 is unknown, the distribution of ΔT, that is, the stress distribution, can be measured from the difference in propagation time depending on the location.
一般に材料の弾性限界内での応力変化に対する
表面弾性波速度の変化は、応力の方向と、表面弾
性波の伝播方向とが一致する時、最も大きく、
ΔＴ／T0で10-3程度になる。従つて、時間差
測定器２２として、10-6程度の精度のものを用い
れば、弾性限界までの応力に対して10-3程度の精
度の応力変化の測定が可能である。 Generally, the change in surface acoustic wave velocity due to stress change within the elastic limit of the material is greatest when the direction of stress and the propagation direction of the surface acoustic wave coincide, and is approximately 10 -3 at ΔT/T 0 . . Therefore, if a time difference measuring device 22 with an accuracy of about 10 -6 is used, it is possible to measure stress changes with an accuracy of about 10 -3 for stress up to the elastic limit.
第４図から第７図は、本発明を理解するための
参考図である。第４図は、いわゆるシングアラウ
ンド法を示す。ここでは、パルス信号１６と受信
信号１９の時間間隔Ｔを測定するのに、受信器２
０で検出された受信信号１９の波形整形回路３０
と、パルス信号１６を一定時間遅延させるゲート
回路３２と、前記波形整形回路３０及びゲート回
路３２の出力が一致した時発振器１８にパルス発
振のためのトリガー信号を与えるAND回路３４
と、発振パルスの周期を測定するカウンタ３６と
を用いている点が前記原理説明図に示された構成
と異なる。他の部分については前記原理説明図に
示された構成と同様であるので説明は省略する。 4 to 7 are reference diagrams for understanding the present invention. FIG. 4 shows the so-called sing-around method. Here, in order to measure the time interval T between the pulse signal 16 and the received signal 19, the receiver 2
Waveform shaping circuit 30 for received signal 19 detected at 0
, a gate circuit 32 that delays the pulse signal 16 for a certain period of time, and an AND circuit 34 that provides a trigger signal for pulse oscillation to the oscillator 18 when the outputs of the waveform shaping circuit 30 and gate circuit 32 match.
This configuration differs from the configuration shown in the principle explanatory diagram in that it uses a counter 36 and a counter 36 for measuring the period of the oscillation pulse. The other parts are the same as the configuration shown in the above-mentioned principle explanatory diagram, so the explanation will be omitted.
前記ゲート回路３２としては、例えば第５図及
び第６図に示すごとく、周波数安定度の高い発振
信号３９を発振する水晶発振器などの発振器３８
と、該発振器３８の出力３９を所定数カウントす
ることにより、入力信号１６より一定時間遅延し
たパルス４１を出力する遅延回路４０とから構成
することができる。 The gate circuit 32 may include an oscillator 38 such as a crystal oscillator that oscillates an oscillation signal 39 with high frequency stability, as shown in FIGS. 5 and 6, for example.
and a delay circuit 40 that outputs a pulse 41 delayed by a certain period of time from the input signal 16 by counting the output 39 of the oscillator 38 by a predetermined number.
以下、第７図を参照しながら動作を説明する。 The operation will be explained below with reference to FIG.
受信信号１９は、波形整形回路３０で波形整形
され、受信信号１９の立上り部が鋭く強調され、
トリガー信号として利用できるパルス波形を有す
る検知信号３１に変換される。 The received signal 19 is waveform-shaped by a waveform shaping circuit 30, and the rising edge of the received signal 19 is sharply emphasized.
It is converted into a detection signal 31 having a pulse waveform that can be used as a trigger signal.
一方ゲート回路３２は、AND回路３４と共に
この検知信号３１のうち、発振パルス１６に対応
する信号のみを選別し、トリガー信号３５を出力
する。すなわちこのゲート回路３２は、雑音等の
不用な信号に、装置回路が応答するのを防ぐ役割
を果たしている。前記AND回路３４の出力のト
リガー信号３５を受けて、発振器１８は前記発振
パルスと同じパルス信号１６を発生する。以下同
じことを繰り返し、全体系として、表面弾性波の
伝播時間Ｔと、トランスデユーサや電気回路など
の遅延時間teの和を周期とするパルス発振が行な
われる。この発振周期T′（＝Ｔ×te）又は発振周
波数＝１／T′をカウンタ３６で測定する。こ
こに
T′＝１／＝Ｔ＋te ……(4)
である。被検体表面の応力の状態によつて表面弾
性波の伝播時間Ｔのみが変化し、回路の遅延時間
teは変化しないので、カウンタ３６で測定した発
振周期T′又は周波数ｆの変化を観測することに
より、前記原理説明図に示された構成と同様にし
て応力の変化を測定することが可能である。 On the other hand, the gate circuit 32 , together with the AND circuit 34 , selects only the signal corresponding to the oscillation pulse 16 from among the detection signals 31 and outputs a trigger signal 35 . That is, this gate circuit 32 plays a role of preventing the device circuit from responding to unnecessary signals such as noise. Upon receiving the trigger signal 35 output from the AND circuit 34, the oscillator 18 generates a pulse signal 16 that is the same as the oscillation pulse. Thereafter, the same process is repeated, and the entire system generates pulse oscillation with a period equal to the sum of the propagation time T of the surface acoustic wave and the delay time te of the transducer, electric circuit, etc. This oscillation period T' (=T×te) or oscillation frequency=1/T' is measured by a counter 36. Here, T'=1/=T+te...(4). Only the propagation time T of the surface acoustic wave changes depending on the state of stress on the surface of the test object, and the delay time of the circuit changes.
Since te does not change, by observing changes in the oscillation period T' or frequency f measured by the counter 36, it is possible to measure changes in stress in the same manner as in the configuration shown in the principle explanatory diagram. .
次に第８図及び第９図により本発明の実施例を
説明する。本実施例は前記参考図に示された構成
に更に他励振のための回路が付加されたものであ
る。即ち、本実施例においては、AND回路３４
と発振器１８との間に、位相比較器４６と、高域
遮断ろ波器４８と、電圧制御発振器５０とが付加
されている。 Next, an embodiment of the present invention will be described with reference to FIGS. 8 and 9. In this embodiment, a circuit for external excitation is further added to the configuration shown in the reference diagram. That is, in this embodiment, the AND circuit 34
A phase comparator 46, a high-cut filter 48, and a voltage controlled oscillator 50 are added between the oscillator 18 and the oscillator 18.
この回路では、電圧制御発振器５０の発振信号
５１によつて、発振器１８の発振周期が決定され
る。発振器１８の出力する発振パルス１６は、前
記実施例と同様の過程を経て、AND回路３４よ
りトリガー信号３５として出力される。位相比較
器４６は、前記発振パルス１６とトリガー信号３
５間の時間差Δｔに、パルスの時間幅及び正負が
比例する位相差信号４７を出力し、その位相差信
号４７は高域遮断ろ波器４８によつて直流電圧４
９に変換される。この直流電圧により、前記電圧
制御発振器５０が制御され、その発振信号５１の
周期は、前記時間差Δｔがゼロとなるように変え
られる。このΔｔがゼロとなり、安定した発振周
期で、電圧制御発振器５０が発振した時、この発
振周期をカウンタ３６で測定すれば、前記参考図
に示された構成と同様に伝播時間Ｔが測定でき、
応力変化又は分布が測定できる。 In this circuit, the oscillation cycle of the oscillator 18 is determined by the oscillation signal 51 of the voltage controlled oscillator 50. The oscillation pulse 16 output from the oscillator 18 is output as a trigger signal 35 from the AND circuit 34 through the same process as in the previous embodiment. The phase comparator 46 detects the oscillation pulse 16 and the trigger signal 3.
A phase difference signal 47 whose pulse time width and positive/negative are proportional to the time difference Δt between the pulses 5 and 5 is output, and the phase difference signal 47 is passed through a high-cut filter 48 to the DC voltage 4.
Converted to 9. The voltage controlled oscillator 50 is controlled by this DC voltage, and the period of the oscillation signal 51 is changed so that the time difference Δt becomes zero. When this Δt becomes zero and the voltage controlled oscillator 50 oscillates with a stable oscillation period, by measuring this oscillation period with the counter 36, the propagation time T can be measured in the same manner as in the configuration shown in the reference diagram.
Stress changes or distribution can be measured.
本実施例においては、何らかの理由で受信信号
１９が一時的に得られない場合でも、電圧制御発
振器５０が発振を続けるので、再び受信信号１９
が得られる状態になると、直ちに安定した発振状
態にもどるという、自動復帰機能を有する。 In this embodiment, even if the received signal 19 cannot be obtained temporarily for some reason, the voltage controlled oscillator 50 continues to oscillate, so that the received signal 19 is not obtained again.
It has an automatic recovery function that immediately returns to a stable oscillation state when the oscillation condition is reached.
第１０図及び第１１図は本発明の参考図であ
る。この参考例では発振器５４が前記実施例と異
なり連続波を発生する発振器であり、該発振連続
波５５と受信連続波５６との位相差を位相差計５
８で測定するようにしている。 FIG. 10 and FIG. 11 are reference views of the present invention. In this reference example, the oscillator 54 is an oscillator that generates a continuous wave, unlike the previous embodiment, and the phase difference between the oscillated continuous wave 55 and the received continuous wave 56 is measured by a phase difference meter.
I try to measure at 8.
また被検体が圧延コイル等の移動物体である場
合には、進行方向及び進行方向と逆方向の複数個
設置し、速度補正を行なうことにより、移動物体
の応力用布を測定することも可能である。 In addition, if the object to be tested is a moving object such as a rolled coil, it is also possible to measure the stress cloth of the moving object by installing multiple pieces in the traveling direction and in the opposite direction to the traveling direction and correcting the speed. be.
本発明によれば、他励振のための回路が付加さ
れているから、何らかの理由で受信信号が一時的
に得られない場合でも、電圧制御発振器が発振を
続けるので、再び受信信号が得られる状態になる
と、直ちに安定した発振状態に戻るという自動復
帰機能を有する装置が得られる。
According to the present invention, since a circuit for external excitation is added, even if the received signal cannot be obtained temporarily for some reason, the voltage controlled oscillator continues oscillating, so that the received signal can be obtained again. When this occurs, a device having an automatic return function that immediately returns to a stable oscillation state can be obtained.
第１図は本発明に係る表面応力の測定装置の原
理を示すブロツク線図、第２図は表面弾性波トラ
ンスデユーサの詳細構成図、第３図は第１図に示
した装置の信号波形を示す図、第４図は本発明の
理解を助けるための参考例を示すブロツク線図、
第５図はゲート回路の詳細構成図、第６図はゲー
ト回路の信号波形を示す図、第７図は第４図に示
した装置の信号波形を示す図、第８図は本発明の
一実施例を示す図、第９図は第８図に示した装置
の信号波形を示す図、第１０図は本発明の参考例
を示すブロツク線図、第１１図は第１０図に示さ
れた装置の信号波形を示す図である。
１０……被検体、１２，１４……表面弾性波用
トランスデユーサ、１５……表面弾性波、１６…
…発振信号、１８……発振器、１９……表面弾性
波信号、２０……受信器、２２……時間差測定
器、２６……結合材、３０……波形整形回路、３
２……ゲート回路、３４……AND回路、３６…
…カウンタ、４６……位相比較器、４８……高域
遮断ろ波器、５０……電圧制御発振器、５８……
位相差計。
FIG. 1 is a block diagram showing the principle of a surface stress measuring device according to the present invention, FIG. 2 is a detailed configuration diagram of a surface acoustic wave transducer, and FIG. 3 is a signal waveform of the device shown in FIG. FIG. 4 is a block diagram showing a reference example to help understand the present invention.
FIG. 5 is a detailed configuration diagram of the gate circuit, FIG. 6 is a diagram showing signal waveforms of the gate circuit, FIG. 7 is a diagram showing signal waveforms of the device shown in FIG. 4, and FIG. 8 is a diagram showing one example of the present invention. 9 is a diagram showing the signal waveform of the device shown in FIG. 8, FIG. 10 is a block diagram showing a reference example of the present invention, and FIG. 11 is the same as shown in FIG. 10. FIG. 3 is a diagram showing signal waveforms of the device. 10... Subject, 12, 14... Transducer for surface acoustic waves, 15... Surface acoustic waves, 16...
... Oscillation signal, 18 ... Oscillator, 19 ... Surface acoustic wave signal, 20 ... Receiver, 22 ... Time difference measuring device, 26 ... Binding material, 30 ... Waveform shaping circuit, 3
2...gate circuit, 34...AND circuit, 36...
... Counter, 46 ... Phase comparator, 48 ... High frequency cutoff filter, 50 ... Voltage controlled oscillator, 58 ...
Phase difference meter.
Claims (1)
面弾性波を伝播させる第１の表面弾性波用トラン
スデユーサと、このトランスデユーサが設置され
ている被検体の同一表面上に設置され、被検体の
表面を伝播する前記表面弾性波を受波する第２の
表面弾性波用トランスデユーサと、前記第１及び
第２の表面弾性波用トランスデユーサをそれらの
相対距離が変化しないように結合する剛性の結合
材と、前記第１トランスデユーサに表面弾性波を
励起するための信号を印加する発振器と、前記第
２のトランスデユーサに受波される表面弾性波信
号を検出する受信器と、前記受信器で検出された
受信信号の波形整形回路と、発振信号を一定時間
遅延させるゲート回路と、前記波形整形回路及び
ゲート回路の出力が一致した時出力を出すアンド
回路と、該アンド回路出力と発振信号との時間差
に応じた電圧を出力する時間差信号発生回路と、
該時間差信号発生回路の出力電圧により時間差が
ゼロとなるような周期のトリガー信号を発振器に
与える電圧制御発振器と、発振信号の周期を測定
するカウンタとを備え、他励振された発振周期を
求めることにより、前記発振器に発生したパルス
信号と、前記受信器で検出された信号との時間間
隔を測定して前記第１及び第２のトランスデユー
サ間の表面弾性波伝播速度を得る伝播速度測定手
段を備え、前記被検体表面に伝播する表面弾性波
の伝播速度から該被検体表面に沿う応力を測定す
ることを特徴とする表面応力の測定装置。1 A first surface acoustic wave transducer that is installed on the surface of a test object and that propagates a surface acoustic wave to the surface of the test object, and a first surface acoustic wave transducer that is installed on the same surface of the test object on which this transducer is installed. , a second surface acoustic wave transducer that receives the surface acoustic wave propagating on the surface of the object, and a relative distance between the first and second surface acoustic wave transducers does not change. an oscillator for applying a signal for exciting a surface acoustic wave to the first transducer; and detecting a surface acoustic wave signal received by the second transducer. a waveform shaping circuit for a received signal detected by the receiver, a gate circuit for delaying the oscillation signal for a certain period of time, and an AND circuit that outputs an output when the outputs of the waveform shaping circuit and the gate circuit match. , a time difference signal generation circuit that outputs a voltage according to the time difference between the AND circuit output and the oscillation signal;
A voltage controlled oscillator that provides an oscillator with a trigger signal having a period such that the time difference becomes zero according to the output voltage of the time difference signal generation circuit, and a counter that measures the period of the oscillation signal, and determines the separately excited oscillation period. propagation velocity measuring means for measuring a time interval between a pulse signal generated by the oscillator and a signal detected by the receiver to obtain a surface acoustic wave propagation velocity between the first and second transducers; A surface stress measuring device comprising: measuring stress along the surface of the object from the propagation velocity of a surface acoustic wave propagating to the surface of the object.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3531577A JPS53121675A (en) | 1977-03-31 | 1977-03-31 | Method and apparatus of measuring surface stress |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3531577A JPS53121675A (en) | 1977-03-31 | 1977-03-31 | Method and apparatus of measuring surface stress |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS53121675A JPS53121675A (en) | 1978-10-24 |
| JPS6156450B2 true JPS6156450B2 (en) | 1986-12-02 |
Family
ID=12438363
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3531577A Granted JPS53121675A (en) | 1977-03-31 | 1977-03-31 | Method and apparatus of measuring surface stress |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS53121675A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61173544U (en) * | 1985-04-17 | 1986-10-28 | ||
| JPH01111738U (en) * | 1988-01-16 | 1989-07-27 | ||
| JPH0349136Y2 (en) * | 1985-09-27 | 1991-10-21 | ||
| JP2004037436A (en) * | 2002-07-02 | 2004-02-05 | Sakai Iron Works Co Ltd | Method of measuring sound elastic stress by surface sh wave and measuring sensor |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1986005272A1 (en) * | 1985-02-27 | 1986-09-12 | Hitachi Construction Machinery Co., Ltd | Method of measuring stress in plate material with ultrasonic waves |
| JPS61254849A (en) * | 1985-05-08 | 1986-11-12 | Hitachi Metals Ltd | Stress measuring method |
| EP0229837A1 (en) * | 1985-06-14 | 1987-07-29 | Hitachi Construction Machinery Co., Ltd. | Method of measuring contact stress in contact surface between solids by ultrasonic wave |
| JPH0820319B2 (en) * | 1987-03-30 | 1996-03-04 | 株式会社ニコン | Analog switch |
| US5016200A (en) * | 1989-10-30 | 1991-05-14 | Frank Passarelli | Weight determining apparatus utilizing acoustic wave elapsed time measurement and computer |
| US5109177A (en) * | 1989-11-28 | 1992-04-28 | Tektronix, Inc. | Damped cradle for saw device |
| JP2555525B2 (en) * | 1993-03-31 | 1996-11-20 | 株式会社酒井鉄工所 | Sensor for acoustoelastic stress measurement by surface SH wave |
| KR100600807B1 (en) * | 2004-12-04 | 2006-07-18 | 주식회사 엠디티 | SAW based passive radio sensors using energy gatherer |
| JP6362533B2 (en) * | 2013-12-24 | 2018-07-25 | 株式会社神戸製鋼所 | Residual stress evaluation method and residual stress evaluation apparatus |
| JP6529853B2 (en) * | 2015-08-05 | 2019-06-12 | 株式会社神戸製鋼所 | Residual stress evaluation method |
| JP6529887B2 (en) * | 2015-10-22 | 2019-06-12 | 株式会社神戸製鋼所 | Residual stress evaluation method |
-
1977
- 1977-03-31 JP JP3531577A patent/JPS53121675A/en active Granted
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61173544U (en) * | 1985-04-17 | 1986-10-28 | ||
| JPH0349136Y2 (en) * | 1985-09-27 | 1991-10-21 | ||
| JPH01111738U (en) * | 1988-01-16 | 1989-07-27 | ||
| JP2004037436A (en) * | 2002-07-02 | 2004-02-05 | Sakai Iron Works Co Ltd | Method of measuring sound elastic stress by surface sh wave and measuring sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS53121675A (en) | 1978-10-24 |
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