JPH09133560A - Ultrasonic flowmeter - Google Patents
Ultrasonic flowmeterInfo
- Publication number
- JPH09133560A JPH09133560A JP29117995A JP29117995A JPH09133560A JP H09133560 A JPH09133560 A JP H09133560A JP 29117995 A JP29117995 A JP 29117995A JP 29117995 A JP29117995 A JP 29117995A JP H09133560 A JPH09133560 A JP H09133560A
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- Prior art keywords
- wave detection
- time
- signal
- received wave
- detection signal
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は超音波流量計に関す
る。[0001] The present invention relates to an ultrasonic flowmeter.
【０００２】[0002]
【従来の技術】図６において、静止流体中の音速をＣ、
流体の流れの速さをＶとすると、音波の伝搬方向が流れ
に沿った方向（以下順方向という）と一致すればその伝
搬速度は（Ｃ＋Ｖ）となり、流れに逆らった方向（以下
逆方向という）の場合には（Ｃ−Ｖ）となる。2. Description of the Related Art In FIG.
When the velocity of the fluid flow is V, if the propagation direction of the sound wave matches the direction along the flow (hereinafter referred to as the forward direction), the propagation velocity becomes (C + V), and the direction opposite to the flow (hereinafter referred to as the reverse direction). In the case of), it becomes (CV).
【０００３】距離Ｌを隔てて１組の送受波器２，３を流
管１の上流と下流に離して配設し、送波器２から順方向
に超音波を発射したとき、受波器３に超音波が到達する
に要する時間をｔ1 、送波器３から逆方向に超音波を発
射したときに、受波器２に超音波が到達するに要する時
間をｔ2 とすれば、 ｔ1 ＝Ｌ／（Ｃ＋Ｖ） ……（１） ｔ2 ＝Ｌ／（Ｃ−Ｖ） ……（２） となる。When a pair of transducers 2 and 3 are disposed at a distance L from each other upstream and downstream of the flow tube 1 and ultrasonic waves are emitted from the transducer 2 in the forward direction, the Assuming that the time required for the ultrasonic wave to reach 3 is t 1 and the time required for the ultrasonic wave to reach the receiver 2 when the ultrasonic wave is emitted from the transmitter 3 in the reverse direction is t 2 , t 1 = L / (C + V) (1) t 2 = L / (C−V) (2)
【０００４】順方向と逆方向の超音波の上記伝搬時間ｔ
1 ，ｔ2 を測定し、これらから流速Ｖを算出して、さら
に流量を求め（積算し）ていた。流速Ｖは上記（１），
（２）式から Ｖ＝Ｌ〔（１／ｔ1 ）−（１／ｔ2 ）〕／２ として求めていた。The above-mentioned propagation time t of ultrasonic waves in the forward and reverse directions
1 , 1 and t 2 were measured, the flow velocity V was calculated from them, and the flow rate was further calculated (integrated). The flow velocity V is (1) above,
From the equation (2), V = L [(1 / t 1 ) − (1 / t 2 )] / 2 was calculated.
【０００５】伝搬時間計測の分解能を上げるために、１
回の超音波の送受ではなく、受信と同時に次の同方向の
送信を行い、同方向の送受を複数回（ｎ回）連続して繰
り返し、最初の第１回目の送信から最後の第ｎ回目の受
信までの時間を測定し、その値より１回の送信から受信
までの時間つまり伝搬時間ｔ1 又はｔ2 を求めるように
していた。To improve the resolution of propagation time measurement, 1
Instead of transmitting and receiving ultrasonic waves one time, the next transmission in the same direction is performed at the same time as reception, and transmission and reception in the same direction is repeated a plurality of times (n times) continuously, from the first transmission of the first to the last nth transmission. The time from the reception of the signal is measured, and the time from the one transmission to the reception, that is, the propagation time t 1 or t 2 is calculated from the value.
【０００６】超音波が受信用の送受波器、つまり受波器
に到達した時期を検知する受信波検知回路は、増幅器と
比較器で構成されており、消費電流が大きかった。受信
用の送受波器の信号は非常に小さく、周波数が大きいた
め、超音波の到達時期を正確に検知するためには、高性
能のアンプを使う必要があり、これらの増幅器は消費電
流が大きいためである。[0006] A receiving wave detecting circuit for detecting a time at which an ultrasonic wave reaches a receiving transmitter / receiver, that is, a receiving device, is composed of an amplifier and a comparator, and consumes a large amount of current. Since the signal of the receiving transducer is very small and the frequency is large, it is necessary to use a high-performance amplifier to accurately detect the arrival time of the ultrasonic wave, and these amplifiers consume a large amount of current. That's why.
【０００７】[0007]
【発明が解決しようとする課題】前記従来の技術では、
受信波検知部の消費電流が大きいため電池駆動の超音波
流量計は電池寿命の面から実用化できないという問題点
があった。In the above prior art,
There is a problem that the battery-driven ultrasonic flowmeter cannot be put into practical use from the viewpoint of battery life because the current consumption of the received wave detection unit is large.
【０００８】そこで、本発明はかかる問題点を解消でき
る超音波流量計を提供することを目的とする。Therefore, an object of the present invention is to provide an ultrasonic flowmeter capable of solving such a problem.
【０００９】[0009]
【課題を解決するための手段】前記目的を達成するため
に、請求項１の発明は、流体の流れ中を流れと同方向あ
るいは斜め方向に超音波の送受をする１対の超音波送受
波器（２）（３）と、受信側の送受波器（３又は２）が
接続され、受信波を検知する受信波検知部（４）と、第
１送信指令信号を入力した時送信側の送受波器（２又は
３）を駆動し、その後は受信波検知部（４）よりの受信
波検知信号ごとに駆動を行う送波器駆動部（６）と、受
信波検知部（４）よりの受信波検知信号を受け、ｎ番目
の受信波検知信号を検知して第ｎ受信波検知信号を出力
する第１のカウンタ（８）と、第１送信指令信号から第
ｎ受信波検知信号までの時間を測定する第２のカウンタ
（９）と、交互に送受の切替を行いながら一定のタイミ
ングで第１送信指令信号を出力し、第ｎ受信波検知信号
を受けると第２のカウンタ（９）の測定値を読み取り、
流速、流量等の演算を行うコントロール部（７）と、コ
ントロール部（７）より第１送信指令信号を入力する
と、その時点から超音波の伝搬時間（ｔ1 又はｔ2 ）よ
り短い時間（ｔ1 ′又はｔ2 ′）後にＯＮ信号を出力
し、その後は受信波検知部（４）よりの受信波検知信号
を入力すると、同時間（ｔ1 ′又はｔ2 ′）後にＯＮ信
号を出力するタイマ（１１）と、タイマ（１１）から入
力されたＯＮ信号で受信波検知部（４）の電源をＯＮ
し、受信波検知部（４）よりの受信波検知信号を入力す
ると同電源をＯＦＦする受信波検知部電源コントロール
部（１２）とを具備したことを特徴とする超音波流量計
である。In order to achieve the above-mentioned object, the invention of claim 1 is a pair of ultrasonic wave transmission / reception in which ultrasonic waves are transmitted / received in a fluid flow in the same direction or in an oblique direction. The receivers (2) and (3) are connected to the receiver-side transmitter / receiver (3 or 2), and the receiver wave detector (4) for detecting the receiver wave and the transmitter side when the first transmission command signal is input. The transmitter / receiver drive unit (6) for driving the wave transmitter / receiver (2 or 3) and thereafter driving for each received wave detection signal from the received wave detection unit (4), and the received wave detection unit (4) From the first transmission command signal to the nth received wave detection signal, and the first counter (8) that receives the received wave detection signal of And a second counter (9) that measures the time of the Outputs a signal to read a measured value of the receiving the n-th reception wave detection signal a second counter (9),
When the first transmission command signal is input from the control unit (7) for calculating the flow velocity, the flow rate, etc. and the control unit (7), the time (t 1 or t 2 ) shorter than the ultrasonic propagation time (t 1 or t 2 ) 1 'or t 2') outputs an oN signal after, then by entering the reception wave detection signal from the reception wave detection unit (4), and outputs the oN signal after the time (t 1 'or t 2') The power of the received wave detection unit (4) is turned on by the timer (11) and the ON signal input from the timer (11).
The ultrasonic flowmeter is provided with a received wave detection unit power supply control unit (12) that turns off the power when the received wave detection signal from the received wave detection unit (4) is input.
【００１０】そして、請求項２の発明は、請求項１の超
音波流量計において、タイマ（１１）が、第１送信指令
信号または受信波検知信号からの時間を計測すると共
に、受信検知信号が入るとその時点の計測値を出力する
と共にリセットされて次の計測に移る時間計測器（１１
Ａ）と、受信波検知信号が入った時点の時間計測器（１
１Ａ）の計測値を記憶する記憶器（１１Ｂ）と、時間計
測器（１１Ａ）の計測値が記憶器（１１Ｂ）に記憶され
ている値より一定値小さい値となった時にＯＮ信号を出
力する比較器（１１Ｃ）とを具備し、受信波検知部の２
回目以降の電源ＯＮは比較器（１１ｃ）よりのＯＮ信号
で行うようにしたことを特徴とするものである。According to a second aspect of the present invention, in the ultrasonic flowmeter of the first aspect, the timer (11) measures a time from the first transmission command signal or the reception wave detection signal, and the reception detection signal is When it enters, it outputs the measured value at that time and is reset, and the time measuring device (11) moves to the next measurement.
A) and a time measuring device (1) at the time when the reception wave detection signal is input.
A storage device (11B) for storing the measurement value of 1A) and an ON signal are output when the measurement value of the time measuring device (11A) becomes a value smaller than the value stored in the storage device (11B) by a constant value. Comprising a comparator (11C) and a reception wave detector 2
The power supply is turned on after the first time by using an ON signal from the comparator (11c).
【００１１】[0011]
【発明の実施の形態】図１は本発明の第１実施例で、請
求項１の発明に対応する。同図において、２，３は１対
の超音波送受波器で、従来技術と同様に、流体の流れ中
を流れと同方向あるいは斜め方向に超音波の送受をす
る。FIG. 1 shows a first embodiment of the present invention, which corresponds to the first aspect of the present invention. In the figure, reference numerals 2 and 3 denote a pair of ultrasonic transducers for transmitting and receiving ultrasonic waves in the same direction or obliquely to the flow of a fluid as in the prior art.
【００１２】４は受信波検知部で、信号切替器５によっ
て選択された受信側の送受波器３又は２がその入力に接
続され、受信波を検知すると受信波検知信号（図２参
照）を出力する。図２では第１，第２，第３，…，第ｎ
の各受信波検知信号に１，２，３，…，ｎの各符号をつ
けている。Reference numeral 4 denotes a reception wave detector, which is connected to the input of the transmitter / receiver 3 or 2 on the reception side selected by the signal switch 5 and detects a reception wave to generate a reception wave detection signal (see FIG. 2). Output. In FIG. 2, the first, second, third,...
, N are attached to the respective received wave detection signals.
【００１３】６は後述するコントロール部７から第１送
信指令信号を入力した時に送信側の送受波器２又は３を
駆動し、その後は受波器検知部４よりの受波器検知信号
ごとに駆動を行う送波器駆動部である。6 drives the transmitter / receiver 2 or 3 on the transmitting side when a first transmission command signal is inputted from a control unit 7 described later, and thereafter, for each receiver detection signal from the receiver detector 4 This is a transmitter driving unit for driving.
【００１４】８は受信波検知部４よりの受信波検知信号
を受け、順方向測定時と逆方向測定時のそれぞれの間に
おいて、ｎ番目の受信波検知信号を検知して第ｎ受信波
検知信号を出力する第１のカウンタである。Numeral 8 receives the reception wave detection signal from the reception wave detection unit 4 and detects the n-th reception wave detection signal between the forward measurement and the backward measurement to detect the n-th reception wave. It is a first counter that outputs a signal.
【００１５】９は順方向測定時と逆方向測定時のそれぞ
れのときに、第１送信指令信号から第ｎ受信波検知信号
までの時間を測定する第２のカウンタである。７はコン
トロール部で、信号切替器５と切替スイッチ１０を同期
して切替えることで一定時間間隔で交互に送受の切替を
行いながら前記一定時間間隔のｎ倍より長い一定のタイ
ミングで順方向と逆方向の各測定期間の始めに第１送信
指令信号を出力し、第ｎ受信波検知信号を受けると第２
のカウンタ９の測定値を読み取り、流速、流量等の演算
を行う。Reference numeral 9 denotes a second counter for measuring the time from the first transmission command signal to the n-th received wave detection signal at each of forward measurement and reverse measurement. Reference numeral 7 denotes a control unit, which switches the signal switch 5 and the changeover switch 10 in synchronism with each other to alternately switch between transmission and reception at a constant time interval and reverse the forward direction at a constant timing longer than n times the constant time interval. The first transmission command signal is output at the beginning of each measurement period in the direction and the second signal is received when the nth received wave detection signal is received.
The measurement value of the counter 9 is read to calculate the flow velocity, flow rate and the like.
【００１６】１１はタイマで、コントロール部７より第
１送信指令信号を入力すると、その時点より超音波の伝
搬時間ｔ1 又はｔ2 より短い時間ｔ1 ′又はｔ2 ′後に
ＯＮ信号を出力し、その後は受信波検知部４よりの受信
波検知信号を入力すると、同時間ｔ1 ′又はｔ2 ′後に
ＯＮ信号を出力する（図２参照）。Reference numeral 11 denotes a timer, which receives an input of the first transmission command signal from the control unit 7 and outputs an ON signal after a time t 1 ′ or t 2 ′ shorter than the propagation time t 1 or t 2 of the ultrasonic wave from that time. Thereafter, when the reception wave detection signal from the reception wave detection unit 4 is input, an ON signal is output after the same time t 1 ′ or t 2 ′ (see FIG. 2).
【００１７】１２は受信波検知部電源コントロール部
で、タイマ１１から入力されたＯＮ信号で受信波検知部
４の電源をＯＮし、受信波検知部４よりの受信波検知信
号を入力すると同電源をＯＦＦするように構成されてい
る。Reference numeral 12 denotes a received wave detection unit power supply control unit, which turns on the power of the received wave detection unit 4 with an ON signal input from the timer 11 and inputs the received wave detection signal from the received wave detection unit 4. Is configured to be turned off.
【００１８】なお、受信波検知部電源コントロール部１
２はＲＳフリップフロップを用いて実現することができ
る。１３は電源用の電池である。The received wave detector power supply controller 1
2 can be realized by using an RS flip-flop. Reference numeral 13 denotes a power supply battery.
【００１９】次に上記構成の超音波流量計の作用を図２
のタイミングチャートを参照して説明する。図２は順方
向又は逆方向の一方の場合のｎ回の超音波の伝搬時間ｎ
ｔ1 又はｎｔ2 を計測するときのタイムチャートであ
る。Next, the operation of the ultrasonic flowmeter constructed as described above will be described with reference to FIG.
This will be described with reference to the timing chart of FIG. FIG. 2 shows the propagation time n of n ultrasonic waves in either the forward direction or the reverse direction.
It is a time chart of when measuring the t 1 or nt 2.
【００２０】コントロール部７からの送受切替え信号で
信号切替器５と切替スイッチ１０を図１の状態に操作し
ているときは、送受波器２が送波器として、送受波器３
が受波器として使用されて、順方向の計測を行う。When the signal switch 5 and the changeover switch 10 are operated in the state shown in FIG. 1 by the transmission / reception switching signal from the control unit 7, the transmitter / receiver 2 functions as the transmitter and the transmitter / receiver 3
Is used as a receiver to perform forward measurement.
【００２１】順方向の計測手順の始めに、コントロール
部７から第１送信指令信号が出力され、該信号を受けて
送波器駆動部６が送受波器２を駆動し、送受波器２から
１番目の超音波が順方向に発射される。At the beginning of the forward measurement procedure, a first transmission command signal is output from the control unit 7, and the transmitter driving unit 6 drives the transmitter / receiver 2 in response to the first transmission command signal. The first ultrasonic wave is emitted in the forward direction.
【００２２】また、タイマ１１が前記第１送信指令信号
を受け、その後超音波の伝搬時間ｔ 1 よりわずかに短い
時間（確実に受信波検知部がＯＮされてから立上る時
間）ｔ 1 ′後にＯＮ信号を出力する。受信波検知部電源
コントロール部１２はこのＯＮ信号を受けて、受信波検
知部４用の電源をＯＮする。従って、受信波検知部４が
作動して、送受波器２から発射された超音波の送受波器
３による受信波を検知し、１番目の受信波検知信号を出
力する。Further, the timer 11 is provided with the first transmission command signal.
And then the ultrasonic propagation time t 1Slightly shorter
Time (when the receiver rises after the received wave detector is turned on
Between) t 1'After that, an ON signal is output. Received wave detector power supply
The control unit 12 receives the ON signal and detects the received wave.
Turn on the power supply for the intelligence unit 4. Therefore, the reception wave detector 4
Actuating and transmitting / receiving ultrasonic waves emitted from the transducer 2
3 and outputs the first received wave detection signal.
Power.
【００２３】この受信波検知信号は送波器駆動回路６、
第１のカウンタ８、タイマ１１及び受信波検知部電源コ
ントロール部１２とに入力される。そして、送波器駆動
回路６は送受波器２を駆動して２番目の超音波を発射す
る。また受信波検知部電源コントロール１２は受信波検
知部４からの受信波検知信号をＯＦＦ信号として受けと
り、受信波検知部用電源をＯＦＦする。The received wave detection signal is transmitted to the transmitter driving circuit 6,
The signals are input to the first counter 8, the timer 11, and the power control unit 12 of the reception wave detection unit. Then, the transmitter driving circuit 6 drives the transmitter / receiver 2 to emit the second ultrasonic wave. Further, the reception wave detection unit power supply control 12 receives the reception wave detection signal from the reception wave detection unit 4 as an OFF signal, and turns off the power for the reception wave detection unit.
【００２４】こうして、１番目の超音波を受信するとき
に、受信波検知部４は超音波が到達するわずか前に電源
がＯＮして作動を開始し、受信波を受信検知すると電源
がＯＦＦして無駄な電力消費を無くす。In this way, when receiving the first ultrasonic wave, the reception wave detecting section 4 is turned on and starts operation slightly before the ultrasonic wave arrives, and turns off when the reception wave is detected. And eliminate unnecessary power consumption.
【００２５】また、第２のカウンタ９は第１送信指令信
号からの時間をクロック信号を計数することで計測し始
めている。こうして順方向の計測が複数個（ｎ回）繰り
返されて、第１のカウンタ８が第ｎ受信波検知信号を出
力すると、該信号をコントロール部７が受けて、第２の
カウンタ９のカウント値ｎｔ1 を読み取る。The second counter 9 has started measuring the time from the first transmission command signal by counting the clock signal. When the measurement in the forward direction is repeated a plurality of times (n times) and the first counter 8 outputs the nth received wave detection signal, the control unit 7 receives the signal and the count value of the second counter 9 Read nt 1 .
【００２６】この順方向の計測の間に受信波検知部４は
ｎ回電源が投入されるが、各回の電源投入時間は（ｔ1
−ｔ1 ′）ずつで、時間ｔ1 ′をｔ1 に近づけることで
時間（ｔ1 −ｔ1 ′）を短くでき、電力消費が減らせ
る。During the forward measurement, the reception wave detector 4 is powered on n times, and each power-on time is (t 1).
−t 1 ′), the time (t 1 −t 1 ′) can be shortened by bringing the time t 1 ′ closer to t 1 , and the power consumption can be reduced.
【００２７】こうして順方向の計測が終了したあと、コ
ントロール部７が信号切替器５と切替スイッチ１０を図
１の状態から切替えて、送受波器３を送波器として、送
受波器２を受波器として使用する逆方向の計測状態にモ
ードを切替える。After the measurement in the forward direction is completed, the control unit 7 switches the signal switch 5 and the changeover switch 10 from the state shown in FIG. 1 to use the transmitter / receiver 3 as the transmitter and the transmitter / receiver 2 for receiving. The mode is switched to the reverse measurement state used as a wave device.
【００２８】逆方向計測時も順方向計測時と同様に送受
波器３から超音波がｎ回発射され、第１送信指令信号か
ら、第ｎ受信波検知信号までの時間ｎｔ2 が第２のカウ
ンタ９で計数され、そのカウント値がコントロール部７
で読み取られる。Similarly to the forward measurement, the ultrasonic wave is emitted from the transducer 3 n times during the backward measurement, and the time nt 2 from the first transmission command signal to the nth received wave detection signal is the second time. It is counted by the counter 9 and the count value is stored in the control unit 7.
Is read in.
【００２９】コントロール部７は、順方向時と逆方向時
の第２のカウンタの各カウント値を読み取って流速、流
量を演算する。こうして、順方向と逆方向の計測を行う
間の所要時間はほぼｎ（ｔ1 ＋ｔ2 ）であるが、この間
の受信波検知部４の電源が投入されている時間はｎ（ｔ
1 −ｔ 1 ′）＋ｎ（ｔ2 −ｔ2 ′）で、ｔ1 −ｔ1 ′を
Δｔ1 、ｔ2 −ｔ2 ′をΔｔ2とあらわすと、ｎ（Δｔ
1 ＋Δｔ2 ）で済み、Δｔ1 とΔｔ2 を必要最小限の時
間に設定することで、受信波検知部４の消費電力を大幅
に低減できる。The control unit 7 operates in the forward direction and the reverse direction.
Of each of the second counters is read to determine the flow velocity and flow rate.
Calculate the quantity. In this way, measurement in the forward and reverse directions is performed.
The time required between them is almost n (t1+ TTwo), But during this time
The power-on time of the reception wave detector 4 is n (t
1-T 1') + N (tTwo-TTwo'), T1-T1′
Δt1, TTwo-TTwo'To ΔtTwoThen, n (Δt
1+ ΔtTwo) And Δt1And ΔtTwoThe minimum time
The power consumption of the received wave detector 4 can be greatly increased by setting
Can be reduced to
【００３０】Δｔ1 ′とΔｔ2 ′は音速、流速の範囲及
び受信波検知部の電源ＯＮからの立上り時間を考えて決
定する。こうして、受信波検知部４が作動している時間
は、従来技術と比較して（Δｔ 1 ＋Δｔ2 ）／（ｔ1 ＋
ｔ2 ）に減少する。Δt1'And ΔtTwo′ Is the range of sound speed and flow velocity
And the rise time from when the power of the received wave detector is turned on.
Set. Thus, the time during which the received wave detection unit 4 is operating
Is (Δt 1+ ΔtTwo) / (T1+
tTwo).
【００３１】ところで、前記図７で説明したように、受
信波検知回路４は、受信波の先頭イを検知することは困
難で、現実には図７における第３波の終了時点のゼロク
ロスポイント「ロ」を検出している。As described with reference to FIG. 7, it is difficult for the received wave detection circuit 4 to detect the head A of the received wave. In practice, the zero cross point " B) has been detected.
【００３２】受信波検知信号はこの点を検知したもので
ある。したがって、求まったｎｔ1（ｎｔ2）は図７での
遅れτや回路の遅れを含んだものとなる。実施例ではこ
の遅れをあらかじめ求め、記憶しておきコントロール部
において補正するようにしている。なお、検知ポイント
は第３波に限る必要はない。図３は、請求項２の発明に
対応し、図１の実施例のうちのタイマ１１の構成を示
す。The received wave detection signal detects this point. Therefore, the obtained nt 1 (nt 2 ) includes the delay τ in FIG. 7 and the delay of the circuit. In the embodiment, this delay is obtained in advance, stored, and corrected in the control unit. Note that the detection point need not be limited to the third wave. FIG. 3 shows the configuration of the timer 11 in the embodiment of FIG.
【００３３】この実施例では、タイマ（１１）が、第１
送信指令信号または受信波検知信号からの時間を計測す
ると共に、受信検知信号が入るとその時点の計測値を出
力すると共にリセットされて次の計測に移る時間計測器
（１１Ａ）と、受信波検知信号が入った時点の時間計測
器（１１Ａ）の計測値を記憶する記憶器（１１Ｂ）と、
時間計測器（１１Ａ）の計測値が記憶器（１１Ｂ）に記
憶されている値より一定値小さい値となった時にＯＮ信
号を出力する比較器（１１Ｃ）とで構成されている。In this embodiment, the timer (11) is set to the first
A time measuring device (11A) for measuring the time from the transmission command signal or the received wave detection signal, outputting the measured value at the time when the received detection signal is input, resetting and resetting to the next measurement; A storage unit (11B) for storing the measurement value of the time measurement unit (11A) at the time when the signal is input;
It comprises a comparator (11C) that outputs an ON signal when the value measured by the time measuring device (11A) becomes smaller than the value stored in the storage device (11B) by a certain value.
【００３４】この請求項２の発明では、超音波の到達時
間を測定して次の回には前回の測定時間をもとにＯＮ信
号を出力するタイミングを決める。１回の送・受の期間
は極めて短いため、連続する２回の到達時間は、流速の
変化も温度つまり音速の変化も小さいと考えられる。According to the second aspect of the present invention, the arrival time of the ultrasonic wave is measured, and the next time the ON signal is output is determined based on the previous measurement time. Since the period of one transmission / reception is extremely short, it is considered that the change of the flow velocity and the change of the temperature, that is, the change of the sound speed are small in two successive arrival times.
【００３５】従って請求項２の発明では、前回の到達時
間から、受信波検知部４が電源ＯＮから動作可能になる
までの必要十分な時間と流速の変化を考慮した小さな値
を引いた時間を、送信から受信波検知部４の電源をＯＮ
するまでの時間に定められるので、受信波検知部４の電
源ＯＮ時間をその都度必要十分な最小値に決められ、消
費電力の低減により効果的である。Therefore, according to the second aspect of the present invention, the time obtained by subtracting a necessary and sufficient time from the previous arrival time until the reception wave detecting unit 4 becomes operable after the power is turned on and a small value in consideration of a change in the flow velocity is obtained. , Turn on the power of the received wave detector 4 from transmission
Since the power-on time of the received wave detection unit 4 is determined to be a necessary and sufficient minimum value each time, it is more effective to reduce power consumption.
【００３６】[0036]
【実施例】図４は、図１の実施例で、請求項１に対応す
る場合のタイマ１１の具体例で、第１送信指令信号と受
信波検知信号を入力するＯＲゲート１１Ｄと、クロック
発振器としての発振器１１Ｅと、発振器１１Ｅのクロッ
クを計数すると共にＯＲゲート１１Ｄの出力でリセット
されるカウンタ１１Ｆと、予め前記時間ｔ1 ′又は
ｔ2 ′を設定しておく設定器１１Ｇと、カウンタ１１Ｆ
の計数値と設定器１１Ｇの設定値とを比較して両者が一
致したときに一致信号としてのＯＮ信号を出力する比較
器１１Ｈとで構成している。FIG. 4 is a concrete example of the timer 11 corresponding to claim 1 in the embodiment of FIG. 1, which is an OR gate 11D for inputting a first transmission command signal and a received wave detection signal, and a clock oscillator. 11E, a counter 11F that counts the clock of the oscillator 11E and is reset by the output of the OR gate 11D, a setter 11G that presets the time t 1 ′ or t 2 ′, and a counter 11F.
And a comparator 11H that outputs an ON signal as a coincidence signal when the two coincide with each other.
【００３７】設定器１１Ｇの設定値は音速や流速の範囲
及び受信波検知部の電源ＯＮから動作可能となるまでの
時間を考慮して決めるが、順方向時と逆方向時の値
ｔ1 ′とｔ2 ′とを条件に合わせて変えると良い。The set value of the setting unit 11G is determined in consideration of the range of the sound velocity and the flow velocity and the time from when the power of the received wave detection unit is turned on until it becomes operable, but the value t 1 ′ in the forward direction and the reverse direction. And t 2 ′ may be changed according to conditions.
【００３８】図５は請求項２の発明に用いるタイマ１１
の具体例で、第１送信指令信号と受信波検知信号を入力
するＯＲゲート１１Ｄと、クロック発振器としての発振
器１１Ｅと、発信器１１Ｅのクロックを計数すると共に
ＯＲゲート１１Ｄの出力でリセットされるカウンタ１１
Ｆと、受信波検知信号がラッチ端子に入るとその時点の
カウンタ１１Ｆの計数値を記憶する記憶器１１Ｉと、記
憶器１１Ｉに記憶されている値からわずかの一定値を減
算する減算器１１Ｊと、減算器１１Ｊの出力とカウンタ
１１Ｆの計数値を比較して両者が一致したときに一致信
号としてのＯＮ信号を出力する比較器１１Ｋとから構成
されている。FIG. 5 shows a timer 11 used in the second aspect of the present invention.
In the specific example, an OR gate 11D for inputting the first transmission command signal and the received wave detection signal, an oscillator 11E as a clock oscillator, and a counter that counts the clock of the oscillator 11E and is reset by the output of the OR gate 11D 11
F, a storage unit 11I that stores the count value of the counter 11F when the received wave detection signal enters the latch terminal, and a subtractor 11J that subtracts a slight constant value from the value stored in the storage unit 11I. And a comparator 11K that compares the output of the subtractor 11J with the count value of the counter 11F and outputs an ON signal as a coincidence signal when they match.
【００３９】この具体例における記憶器１１Ｉは図３の
記憶器１１Ｂに相当し、比較器１１Ｋは図３の比較器１
１Ｃに相当する。なお、図５の具体例で、受信波検知信
号が入ったときのＯＲゲート１１Ｄの出力によるカウン
タ１１Ｆのリセットは、同受信波検知信号が記憶器１１
Ｉのラッチ端子に入力されて、その時点でのカウンタ１
１Ｆの計数値が記憶器１１Ｉにラッチ・記憶されてから
行われるように構成されている。The storage unit 11I in this specific example corresponds to the storage unit 11B in FIG. 3, and the comparator 11K is the comparator 1B in FIG.
1C. In the specific example of FIG. 5, the reset of the counter 11F by the output of the OR gate 11D when the received wave detection signal is input is performed when the received wave detection signal is stored in the memory 11
I is input to the latch terminal of I, and the counter 1 at that time
It is configured to be performed after the count value of 1F is latched and stored in the storage unit 11I.
【００４０】また、実施例では、第１送信指令信号で記
憶器１１Ｉは減算器による減算数を加味した一定値を記
憶するようになっていて、最初のＯＮタイミングを発生
する。In the embodiment, the storage unit 11I stores a constant value in consideration of the subtraction number by the subtractor by the first transmission command signal, and generates the first ON timing.
【００４１】減算器１１Ｊで減算するわずかの一定値
は、受信波検知部４が電源ＯＮしてから動作可能となる
必要で十分な時間とする。The slight constant value to be subtracted by the subtractor 11J is a necessary and sufficient time that the received wave detection unit 4 becomes operable after the power is turned on.
【００４２】[0042]
【発明の効果】本発明の超音波流量計は上述のように構
成されているので、受信波検知部（４）の電源をふだん
はＯＦＦとしておき、超音波が受波器を司る送受波器
（２又は３）に到達する直前にＯＮし、超音波を検知し
たらＯＦＦして、必要最小限の間しかＯＮしないため、
消費電流の大きい増幅・比較回路からなる受信波検知部
の消費電力を低減し、電池駆動の超音波流量計の実用化
の道を開くことができる。Since the ultrasonic flowmeter of the present invention is constructed as described above, the power of the received wave detector (4) is normally turned off, and the ultrasonic wave is transmitted and received by the transducer. It turns on just before reaching (2 or 3), turns off when ultrasonic waves are detected, and turns on only for the minimum necessary time.
The power consumption of the reception wave detection unit including the amplification / comparison circuit that consumes a large amount of current can be reduced, thereby opening the way to practical use of a battery-driven ultrasonic flowmeter.
【００４３】そして、請求項３の発明によれば、受信波
検知部（４）の電源ＯＮの時間を、１回の超音波伝搬
（到達）時間を計測する都度、流速や音速に合わせて必
要な最小値に自動的に修正するので、より一層消費電力
の低減に寄与する。According to the third aspect of the present invention, the power-on time of the reception wave detecting section (4) is required to be adjusted in accordance with the flow velocity and the sound velocity every time one ultrasonic propagation (arrival) time is measured. Since the correction is automatically made to the minimum value, the power consumption is further reduced.
【００４４】また、本発明では、受信波検知部（４）の
電子回路が、必要最小限の間しか作動せず、不必要な大
半の間は電源がＯＦＦしているため、この間に振動等の
音波ノイズがあっても、その悪影響を受けることがな
く、ノイズに強い超音波流量計を実現できる。Also, in the present invention, the electronic circuit of the received wave detection section (4) operates only for a minimum necessary time and the power supply is turned off for most unnecessary periods. Even if there is sonic noise, an ultrasonic flowmeter which is not affected by the sonic noise can be realized.
【図１】本発明の第１実施例のブロック図である。FIG. 1 is a block diagram of a first embodiment of the present invention.
【図２】図１の実施例のタイミングチャートである。FIG. 2 is a timing chart of the embodiment of FIG.
【図３】本発明の第２実施例の一部の構成を示すブロッ
ク図である。FIG. 3 is a block diagram showing a partial configuration of a second embodiment of the present invention.
【図４】図１の実施例のタイマの具体例を示すブロック
図である。FIG. 4 is a block diagram showing a specific example of a timer according to the embodiment of FIG. 1;
【図５】図４のタイマの具体例を示すブロック図であ
る。5 is a block diagram showing a specific example of the timer of FIG.
【図６】超音波流量計の原理を説明する略図である。FIG. 6 is a schematic diagram illustrating the principle of an ultrasonic flowmeter.
【図７】従来技術の受信波検知部の動作を説明するため
の電気信号波形を示す線図である。FIG. 7 is a diagram showing electric signal waveforms for explaining the operation of a reception wave detection unit according to the related art.
２，３ 送受波器 ４ 受信波検知部 ６ 送波器駆動部 ７ コントロール部 ８ 第１のカウンタ ９ 第２のカウンタ １１ タイマ １１Ａ 時間計測器 １１Ｂ 記憶器 １１Ｃ 比較器 １２ 受信波検知部電源コントロール部 ｔ1 ，ｔ1 ′，ｔ2 ，ｔ2 ′ 時間2, 3 Transmitter / receiver 4 Received wave detector 6 Transmitter driver 7 Control unit 8 First counter 9 Second counter 11 Timer 11A Time measuring device 11B Memory device 11C Comparator 12 Received wave detector Power supply control unit t 1 , t 1 ′, t 2 , t 2 ′ time
Claims (2)
め方向に超音波の送受をする１対の超音波送受波器
（２）（３）と、 受信側の送受波器（３又は２）が接続され、受信波を検
知する受信波検知部（４）と、 第１送信指令信号を入力した時送信側の送受波器（２又
は３）を駆動し、その後は受信波検知部（４）よりの受
信波検知信号ごとに駆動を行う送波器駆動部（６）と、 受信波検知部（４）よりの受信波検知信号を受け、ｎ番
目の受信波検知信号を検知して第ｎ受信波検知信号を出
力する第１のカウンタ（８）と、 第１送信指令信号から第ｎ受信波検知信号までの時間を
測定する第２のカウンタ（９）と、 交互に送受の切替を行いながら一定のタイミングで第１
送信指令信号を出力し、第ｎ受信波検知信号を受けると
第２のカウンタ（９）の測定値を読み取り、流速、流量
等の演算を行うコントロール部（７）と、 コントロール部（７）より第１送信指令信号を入力する
と、その時点から超音波の伝搬時間（ｔ1 又はｔ2 ）よ
り短い時間（ｔ1 ′又はｔ2 ′）後にＯＮ信号を出力
し、その後は受信波検知部（４）よりの受信波検知信号
を入力すると、同時間（ｔ1 ′又はｔ2 ′）後にＯＮ信
号を出力するタイマ（１１）と、 タイマ（１１）から入力されたＯＮ信号で受信波検知部
（４）の電源をＯＮし、受信波検知部（４）よりの受信
波検知信号を入力すると同電源をＯＦＦする受信波検知
部電源コントロール部（１２）とを具備したことを特徴
とする超音波流量計。1. A pair of ultrasonic wave transmitters / receivers (2) (3) for transmitting and receiving ultrasonic waves in the same direction as the flow or in an oblique direction in the flow of the fluid, and a transducer (3 or 2) on the reception side. ) Is connected, the received wave detector (4) for detecting a received wave, and the transmitter / receiver (2 or 3) on the transmitter side when the first transmission command signal is input are driven. 4) receives a received wave detection signal from the received wave detection section (4) and a wave transmitter drive section (6) that drives each received wave detection signal from A first counter (8) that outputs the nth received wave detection signal, and a second counter (9) that measures the time from the first transmission command signal to the nth received wave detection signal, and switching between transmission and reception First at a certain timing while performing
From the control unit (7) that outputs the transmission command signal and receives the nth received wave detection signal, reads the measurement value of the second counter (9) and calculates the flow velocity, the flow rate, etc. When the first transmission command signal is input, an ON signal is output after a time (t 1 ′ or t 2 ′) shorter than the propagation time (t 1 or t 2 ) of the ultrasonic wave from that point, and then the reception wave detection unit ( When the received wave detection signal from 4) is input, a timer (11) that outputs an ON signal after the same time (t 1 ′ or t 2 ′) and an ON signal input from the timer (11) The power supply of (4) is turned on, and when the received wave detection signal from the received wave detection unit (4) is input, the received wave detection unit power supply control unit (12) is turned off. Sonic flow meter.
測すると共に、受信検知信号が入るとその時点の計測値
を出力すると共にリセットされて次の計測に移る時間計
測器（１１Ａ）と、 受信波検知信号が入った時点の時間計測器（１１Ａ）の
計測値を記憶する記憶器（１１Ｂ）と、 時間計測器（１１Ａ）の計測値が記憶器（１１Ｂ）に記
憶されている値より一定値小さい値となった時にＯＮ信
号を出力する比較器（１１Ｃ）とを具備し、２回目以降
はこのＯＮ信号で受信波検知部をＯＮするようにしたこ
とを特徴とする請求項１記載の超音波流量計。2. A timer (11) measures time from a first transmission command signal or a reception wave detection signal, and outputs a measurement value at the time when a reception detection signal is input, and is reset to perform a next measurement. (11A), a storage (11B) for storing the measurement value of the time measurement device (11A) at the time when the received wave detection signal is inputted, and a storage device for storing the measurement value of the time measurement device (11A). And a comparator (11C) for outputting an ON signal when the value becomes smaller than the value stored in (11B) by a predetermined value. The ultrasonic flowmeter according to claim 1, wherein:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29117995A JP2828615B2 (en) | 1995-11-09 | 1995-11-09 | Ultrasonic flow meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29117995A JP2828615B2 (en) | 1995-11-09 | 1995-11-09 | Ultrasonic flow meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09133560A true JPH09133560A (en) | 1997-05-20 |
| JP2828615B2 JP2828615B2 (en) | 1998-11-25 |
Family
ID=17765487
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29117995A Expired - Fee Related JP2828615B2 (en) | 1995-11-09 | 1995-11-09 | Ultrasonic flow meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2828615B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002148086A (en) * | 2000-11-15 | 2002-05-22 | Matsushita Electric Ind Co Ltd | Flow rate measuring equipment |
| JP2002365108A (en) * | 2001-06-11 | 2002-12-18 | Aichi Tokei Denki Co Ltd | Ultrasonic flowmeter |
| JP2006292376A (en) * | 2005-04-05 | 2006-10-26 | Tokyo Gas Co Ltd | Ultrasonic flowmeter |
| JP2007064988A (en) * | 2006-12-08 | 2007-03-15 | Matsushita Electric Ind Co Ltd | Flowmeter |
-
1995
- 1995-11-09 JP JP29117995A patent/JP2828615B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002148086A (en) * | 2000-11-15 | 2002-05-22 | Matsushita Electric Ind Co Ltd | Flow rate measuring equipment |
| JP2002365108A (en) * | 2001-06-11 | 2002-12-18 | Aichi Tokei Denki Co Ltd | Ultrasonic flowmeter |
| JP2006292376A (en) * | 2005-04-05 | 2006-10-26 | Tokyo Gas Co Ltd | Ultrasonic flowmeter |
| JP2007064988A (en) * | 2006-12-08 | 2007-03-15 | Matsushita Electric Ind Co Ltd | Flowmeter |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2828615B2 (en) | 1998-11-25 |
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