JPH0618245Y2 - Ultrasonic sensor - Google Patents
Ultrasonic sensorInfo
- Publication number
- JPH0618245Y2 JPH0618245Y2 JP1988066389U JP6638988U JPH0618245Y2 JP H0618245 Y2 JPH0618245 Y2 JP H0618245Y2 JP 1988066389 U JP1988066389 U JP 1988066389U JP 6638988 U JP6638988 U JP 6638988U JP H0618245 Y2 JPH0618245 Y2 JP H0618245Y2
- Authority
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- Japan
- Prior art keywords
- ultrasonic
- holder
- ultrasonic element
- thermal expansion
- fluid
- 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 - Lifetime
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- Measuring Volume Flow (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Description
【考案の詳細な説明】 産業上の利用分野 本考案は超音波センサに係り、特に温度変化に対応して
超音波の送受信について常に安定した特性を維持するよ
う構成した超音波センサに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic sensor, and more particularly to an ultrasonic sensor configured to always maintain stable characteristics in transmitting and receiving ultrasonic waves in response to temperature changes.
従来の技術 例えば、流体中に渦発生体を設け、その下流に発生した
カルマン渦の生成数を超音波を利用して検知することに
より流体の流量を測定する超音波式の渦流量計が知られ
ている。この種の渦流量計では渦発生体の下流側流路壁
に流路をはさんで対向配置された一対の超音波センサを
設けてなり、一方の超音波センサが発振器からの発振信
号の供給により超音波を発生する超音波送信器として機
能し、他方の超音波センサが流体中を伝播する超音波を
受信する超音波受信器として機能する。2. Description of the Related Art For example, an ultrasonic vortex flowmeter is known that measures the flow rate of a fluid by providing a vortex generator in the fluid and detecting the number of Karman vortices generated downstream of it using ultrasonic waves. Has been. This type of vortex flowmeter is equipped with a pair of ultrasonic sensors facing each other across the flow path on the downstream flow path wall of the vortex generator, and one ultrasonic sensor supplies the oscillation signal from the oscillator. Function as an ultrasonic transmitter that generates ultrasonic waves, and the other ultrasonic sensor functions as an ultrasonic receiver that receives ultrasonic waves propagating in the fluid.
そして、流体が流路を流れると渦発生体の下流側には流
速に比例する規則的なカルマン渦が発生し、超音波送信
器からの超音波がカルマン渦と遭遇すると、超音波受信
器により受信される超音波は位相変調を受けることにな
る。従って、超音波がカルマン渦と遭遇する場合と、超
音波がカルマン渦と遭遇しない場合とでは、発振器から
超音波送信器へ入力される信号と超音波受信器から出力
される信号との位相差が異なってくる。そのため、渦流
量計ではこの位相差の変化を検出することによりカルマ
ン渦の生成数が計測される。Then, when the fluid flows through the flow path, a regular Karman vortex that is proportional to the flow velocity is generated on the downstream side of the vortex generator, and when the ultrasonic wave from the ultrasonic transmitter encounters the Karman vortex, the ultrasonic receiver The ultrasonic waves received will undergo phase modulation. Therefore, the phase difference between the signal input from the oscillator to the ultrasonic transmitter and the signal output from the ultrasonic receiver is different between when the ultrasonic wave encounters the Karman vortex and when the ultrasonic wave does not encounter the Karman vortex. Will be different. Therefore, the vortex flowmeter measures the number of generated Karman vortices by detecting the change in the phase difference.
上記のように機能する超音波センサは、例えばステンレ
ス製の有底円筒状のホルダ内に超音波素子を収納し、こ
の超音波素子は接着剤により振動板としてのホルダ底面
に接着固定されていた。The ultrasonic sensor functioning as described above has an ultrasonic element housed in, for example, a stainless steel bottomed cylindrical holder, and the ultrasonic element is adhesively fixed to the bottom surface of the holder as a vibration plate with an adhesive. .
又、上記とは別の超音波センサとしては「特開昭４８−
１０１１６６号公報」により開示された装置がある。こ
の公報の装置では超音波素子をコイルばねの押圧力によ
りホルダ底面に押圧保持する構成となっている。Further, as an ultrasonic sensor different from the above, "Japanese Patent Laid-Open No. 48-
There is a device disclosed in Japanese Patent No. 101166. In the device of this publication, the ultrasonic element is pressed against the bottom surface of the holder by the pressing force of the coil spring.
考案が解決しようとする課題 しかるに、従来の超音波センサでは、超音波素子をホル
ダに接着固定した場合、高温の流体を計測するときには
ホルダに流体の熱が伝導し、ホルダと超音波素子との熱
膨脹変位量の差により接着剤が剥離してしまい、振動伝
達が低下するといった課題がある。尚、ホルダがステン
レス製の場合、ホルダの熱膨脹率は例えば17.8×１０
−６／℃であり、超音波素子がセラミック系である場
合、超音波素子の熱膨脹率は例えば５〜９×１０−６／
℃であるため、ホルダと超音波素子との熱膨脹変位量の
差はホルダの熱膨脹率が超音波素子より相当大きいこと
に起因する。However, in the conventional ultrasonic sensor, when the ultrasonic element is adhered and fixed to the holder, the heat of the fluid is conducted to the holder when measuring the high temperature fluid, and the heat between the holder and the ultrasonic element is There is a problem that the adhesive is peeled off due to the difference in the amount of thermal expansion displacement, and the vibration transmission is reduced. If the holder is made of stainless steel, the coefficient of thermal expansion of the holder is, for example, 17.8 × 10.
When the ultrasonic element is a ceramic type, the coefficient of thermal expansion of the ultrasonic element is, for example, 5 to 9 × 10 −6 /
Since the temperature is ° C, the difference in the thermal expansion displacement amount between the holder and the ultrasonic element is due to the fact that the thermal expansion coefficient of the holder is considerably larger than that of the ultrasonic element.
また、上記公報の装置の如く、超音波素子をばねの押圧
力により保持する場合、環境が変化してもばねの押圧力
が常に一定である必要がある。しかるに、上記装置では
例えば温度変化があるとホルダの熱膨脹によりばね力が
変動してしまうので、超音波の送受信について安定した
特性を得ることが難しいという課題がある。Further, when the ultrasonic element is held by the pressing force of the spring as in the device of the above publication, the pressing force of the spring needs to be always constant even if the environment changes. However, in the above apparatus, the spring force fluctuates due to the thermal expansion of the holder when there is a temperature change, for example, and thus there is a problem in that it is difficult to obtain stable characteristics for ultrasonic wave transmission and reception.
また、熱膨脹による影響が少なくなるように温度変化に
対応してばね力を安定させるためには、コイルばねの全
長が長くなり、このようにすると超音波センサ自体が大
型化してしまい、小型化が要求される渦流量計等の装置
には適用することが難しいといった課題もある。Also, in order to stabilize the spring force in response to temperature changes so as to reduce the effect of thermal expansion, the total length of the coil spring becomes longer, which makes the ultrasonic sensor itself larger and smaller. There is also a problem that it is difficult to apply to required devices such as a vortex flowmeter.
そこで、本考案は上記課題を解決した超音波センサを提
供することを目的とする。Then, this invention aims at providing the ultrasonic sensor which solved the said subject.
課題を解決するための手段 本考案は、超音波を送信又は受信する超音波素子と、 内部に該超音波素子が挿入される挿入部を有し、該挿入
部の底部に前記超音波素子が当接する振動面を有するホ
ルダと、 超音波の放射方向における該ホルダと前記超音波素子と
の熱膨張差を減少する熱膨張率を有し、前記挿入部に挿
入されて前記超音波素子を前記振動面との間で挟持する
ように前記超音波素子に当接する押え部材と、 該押え部材を介して前記超音波素子を前記ホルダの振動
面に押圧するばね部材と、 よりなる。Means for Solving the Problems The present invention has an ultrasonic element for transmitting or receiving ultrasonic waves, and an insertion part into which the ultrasonic element is inserted, and the ultrasonic element is provided at the bottom of the insertion part. A holder having a vibrating surface that abuts, and a coefficient of thermal expansion that reduces a difference in thermal expansion between the holder and the ultrasonic element in the ultrasonic radiation direction, and the ultrasonic element is inserted into the insertion portion to The pressing member is configured to contact the ultrasonic element so as to be sandwiched between the ultrasonic element and the vibration surface, and a spring member that presses the ultrasonic element against the vibration surface of the holder via the pressing member.
作用 本考案は、温度変化があった場合、超音波の放射方向に
おけるホルダの熱膨張量と超音波素子及び押え部材の熱
膨張量とが同一になるように構成されているので、温度
変化により超音波素子やホルダが伸縮しても押え部材が
超音波素子とホルダとの熱膨張差を吸収してばね部材に
よる押圧力を一定に保つことが可能となり、超音波素子
の特性が温度変化に拘わらず安定する。Effect The present invention is configured so that the thermal expansion amount of the holder and the thermal expansion amount of the ultrasonic element and the pressing member in the radiation direction of the ultrasonic waves become the same when there is a temperature change. Even if the ultrasonic element or the holder expands or contracts, the pressing member can absorb the difference in thermal expansion between the ultrasonic element and the holder and keep the pressing force of the spring member constant, and the characteristics of the ultrasonic element will not change due to temperature changes. It stabilizes regardless.
実施例 第１図は本考案の一実施例になる超音波センサが適用さ
れた渦流量計を示し、第２図は前記超音波センサの要部
を示す。Embodiment FIG. 1 shows a vortex flowmeter to which an ultrasonic sensor according to an embodiment of the present invention is applied, and FIG. 2 shows a main part of the ultrasonic sensor.
両図中、渦流量計１は流体を給送する配管（第１図中、
１点鎖線で示す）２，３との間に配設されている。渦流
量計１の流量計本体４に形成された流路４ａ内には、渦
発生体５が上，下方向に延在するように挿入固定されて
いる。渦発生体５の下流側の流壁４ｂには取付孔４ｃが
外周面から内周面に貫通して設けられており、この取付
孔４ｃには一対の超音波センサ６，６が対向配置される
ように挿入固定されている。In both figures, the vortex flowmeter 1 is a pipe for feeding a fluid (in FIG. 1,
It is arranged between the two and three (shown by the one-dot chain line). The vortex generator 5 is inserted and fixed in the flow path 4a formed in the flowmeter body 4 of the vortex flowmeter 1 so as to extend in the upward and downward directions. A mounting hole 4c is provided so as to penetrate from the outer peripheral surface to the inner peripheral surface in the flow wall 4b on the downstream side of the vortex generator 5, and a pair of ultrasonic sensors 6 and 6 are arranged to face each other in the mounting hole 4c. It is inserted and fixed so that
１対の超音波センサ６，６のうち、第１図中において図
面下側にあらわれている取付孔４ｃに挿入された一方の
超音波センサ６は発振器（図示せず）の発振信号を供給
され、第１図中破線で示すように超音波を送信する超音
波送信器である。そして、第１図中において図面上側に
あらわれている取付孔４ｃに挿入された他方の超音波セ
ンサ６は流路４ａ内を通過する流体中を伝播した超音波
を受信する超音波受信器である。Of the pair of ultrasonic sensors 6 and 6, one ultrasonic sensor 6 inserted into the mounting hole 4c appearing on the lower side of the drawing in FIG. 1 is supplied with an oscillation signal of an oscillator (not shown). , An ultrasonic transmitter for transmitting ultrasonic waves as indicated by a broken line in FIG. The other ultrasonic sensor 6 inserted into the mounting hole 4c shown on the upper side of the drawing in FIG. 1 is an ultrasonic receiver for receiving the ultrasonic waves propagated in the fluid passing through the flow path 4a. .
第１図において、流体は配管２から矢印で示す方向に流
れ、流路４ａ内を通過して配管３へ流れていく。このよ
うに、流体が流れると、上記流体中には流路４ａの内部
に挿入配設された渦発生体５の下流側においてその左右
に交互に規則的な、所謂カルマン渦が発生する。この場
合に流体内を通過する超音波が流体内を伝播する途上に
おいて、上記渦発生体５により生成されたカルマン渦と
遭遇すると、カルマン渦の横方向（第１図の紙面と平
行、かつ超音波が伝播する方向）の流速成分に位相変調
を受けることとなる。In FIG. 1, the fluid flows from the pipe 2 in the direction indicated by the arrow, passes through the flow path 4 a, and then flows into the pipe 3. Thus, when the fluid flows, regular so-called Karman vortices are generated in the fluid on the downstream side of the vortex generator 5 inserted and disposed inside the flow path 4a, alternately on the left and right sides thereof. In this case, when an ultrasonic wave passing through the fluid propagates through the fluid and encounters a Karman vortex generated by the vortex generator 5, the Karman vortex laterally (parallel to the paper surface of FIG. The flow velocity component in the direction in which the sound wave propagates) undergoes phase modulation.
従って、送信側の発振信号と受信側の検出信号の位相差
は、流体中を通過する超音波がカルマン渦と遭遇しない
場合の上記一定の位相差とは異なった位相差を示す。渦
流量計１ではこの位相差の変化を検出し、フィルタ（図
示せず）を介して取り出すことにより、流速又は流量に
比例するカルマン渦の生成数を検知し、ひいては被測定
流体の流量又は流速を測定することが可能となる。Therefore, the phase difference between the oscillation signal on the transmission side and the detection signal on the reception side shows a phase difference different from the above-mentioned constant phase difference when the ultrasonic wave passing through the fluid does not encounter the Karman vortex. The vortex flowmeter 1 detects the change in the phase difference and extracts it through a filter (not shown) to detect the flow velocity or the number of Karman vortices generated in proportion to the flow rate, and thus the flow rate or flow velocity of the fluid to be measured. Can be measured.
ここで、本考案の要部である超音波センサ６の詳細につ
き説明する。Here, the details of the ultrasonic sensor 6 which is the main part of the present invention will be described.
第２図に示す如く、超音波センサ６は大略有底円筒状の
ホルダ７と、ホルダ７内の収納室７ａ内に収納された超
音波素子８と、超音波素子８を保持する円柱状の押え部
材９と、ホルダ７を本体４に対して固定する固定部材１
０等とよりなる。As shown in FIG. 2, the ultrasonic sensor 6 includes a holder 7 having a substantially cylindrical shape with a bottom, an ultrasonic element 8 housed in a housing chamber 7 a in the holder 7, and a columnar shape for holding the ultrasonic element 8. A fixing member 1 for fixing the holding member 9 and the holder 7 to the main body 4.
It consists of 0 mag.
ホルダ７はステンレス製であり、振動面としての底面７
ｂが薄肉となっている。又、ホルダ７には取付孔４ｃよ
り小径の外周を有する挿入部７ｃと、取付孔４ｃより大
径の外周を有する鍔部７ｄとが形成されており、底面７
ｂの振動を妨げないように取付孔４ｃと挿入部７ｃとの
間には隙間が形成される。The holder 7 is made of stainless steel and has a bottom surface 7 as a vibrating surface.
b is thin. Further, the holder 7 is formed with an insertion portion 7c having an outer diameter smaller than the mounting hole 4c and a flange portion 7d having an outer diameter larger than the mounting hole 4c.
A gap is formed between the mounting hole 4c and the insertion portion 7c so as not to interfere with the vibration of b.
超音波素子８はセラミック製（ＰＺＴ，チタン酸ジルコ
ン酸鉛）の振動子であり、ホルダ７の底面７ｂに当接し
ている。押え部材９は絶縁材１１を介して超音波素子８
を保持すると共に、後述するように温度変化に伴う超音
波の放射方向におけるホルダ７と超音波素子８との熱膨
脹差を相殺（減少する）機能も有している。尚、本実施
例では、押え部材９は快削黄銅（ＢｓＢＭ−２）製であ
る。The ultrasonic element 8 is a vibrator made of ceramics (PZT, lead zirconate titanate) and is in contact with the bottom surface 7 b of the holder 7. The holding member 9 is an ultrasonic element 8 via an insulating material 11.
And has a function of canceling (reducing) the difference in thermal expansion between the holder 7 and the ultrasonic element 8 in the direction of the ultrasonic wave emission due to temperature change, as will be described later. In this embodiment, the pressing member 9 is made of free-cutting brass (BsBM-2).
１２は押え部材９を超音波素子１０に押圧するさらばね
で、押え部材９を均一な力で押圧するため、ステンレス
製のワッシャ１３を介して押え部材９を押圧する。又さ
らばね１２はホルダ７のメネジ部７ｅに螺入されたナッ
ト１４の下端に当接し、ナット１４のネジ込み量により
その押圧力の大きさが調整される。Reference numeral 12 is a flat spring that presses the pressing member 9 against the ultrasonic element 10, and presses the pressing member 9 through the washer 13 made of stainless steel in order to press the pressing member 9 with a uniform force. Further, the spiral spring 12 contacts the lower end of the nut 14 screwed into the female screw portion 7e of the holder 7, and the pressing force is adjusted by the screwing amount of the nut 14.
固定部材１０はホルダ７の鍔部７ｄが嵌合する凹部１０
ａを有し、本体４のネジ孔（図示せず）に螺入された複
数の取付ネジ１５の締付けにより本体４の外周に固定さ
れる。そのため、ホルダ７は鍔部７ｄが固定部材１０と
本体４の取付面４ｄとの間で挾持されると共に、凹部１
０ａによって取付孔４ｂ，４ｃに対する半径方向の挿入
位置が位置決めされた状態で固定される。１６はＯリン
グで、ホルダ７の鍔部７ｄと固定部材１０の凹部１０ａ
との間、及び固定部材１０と取付面４ｄとの間を液密に
シールする。The fixing member 10 is a recess 10 into which the collar portion 7d of the holder 7 fits.
It has a and is fixed to the outer periphery of the main body 4 by tightening a plurality of mounting screws 15 screwed into screw holes (not shown) of the main body 4. Therefore, in the holder 7, the flange portion 7d is sandwiched between the fixing member 10 and the mounting surface 4d of the main body 4, and the recess 1 is formed.
The insertion position in the radial direction with respect to the mounting holes 4b and 4c is fixed by 0a. Reference numeral 16 denotes an O-ring, which is a flange portion 7d of the holder 7 and a recess 10a of the fixing member 10.
And the fixing member 10 and the mounting surface 4d are liquid-tightly sealed.
又、１７は超音波素子８の端子に接続されたリード線
で、第２図では見えないワッシャ１３の切欠部、破線で
示したナット１４の中央孔１４ａ及び、固定部材１０の
貫通孔１０ｂを挿通して外部に延在する。Further, 17 is a lead wire connected to the terminal of the ultrasonic element 8, which includes a cutout portion of the washer 13 which is not visible in FIG. 2, a central hole 14a of the nut 14 shown by a broken line, and a through hole 10b of the fixing member 10. Insert and extend to the outside.
このように、超音波素子８はホルダ７内に収納保持され
ているため、リード線１７から発振信号を供給されると
振動して超音波を生成し、あるいはホルダ７の底面７ｂ
が流体中を伝播する超音波により振動すると、その検出
信号を出力する。As described above, since the ultrasonic element 8 is housed and held in the holder 7, it vibrates to generate an ultrasonic wave when the oscillation signal is supplied from the lead wire 17, or the bottom surface 7 b of the holder 7.
When is vibrated by the ultrasonic waves propagating in the fluid, the detection signal is output.
前述したように例えばステンレス製のホルダ７の熱膨脹
率は17.8×１０−６／℃で、セラミック製の超音波素子
８の熱膨脹率は５〜９×１０−６／℃である。このよう
にホルダ７と超音波素子８との熱膨脹率の差が大きいた
め、本考案ではこの熱膨脹差を補正すべく押え部材９が
設けられている。As described above, for example, the holder 7 made of stainless steel has a thermal expansion coefficient of 17.8 × 10 −6 / ° C., and the ultrasonic element 8 made of ceramic has a thermal expansion coefficient of 5 to 9 × 10 −6 / ° C. Since the difference in the coefficient of thermal expansion between the holder 7 and the ultrasonic element 8 is large as described above, the pressing member 9 is provided in the present invention to correct the difference in the coefficient of thermal expansion.
この押え部材９は快削黄鋼製であり、その熱膨脹率はお
よそ20.5×１０−６／℃である。即ち、押え部材９の熱
膨脹率はホルダ７のそれよりも大きい。従って、押え部
材９の高さ寸法を選択することにより、超音波の放射方
向におけるホルダ７と超音波素子８との熱膨脹差を相殺
（減少）することができる。This pressing member 9 is made of free-cutting yellow steel, and its coefficient of thermal expansion is approximately 20.5 × 10 −6 / ° C. That is, the coefficient of thermal expansion of the pressing member 9 is larger than that of the holder 7. Therefore, by selecting the height dimension of the pressing member 9, the difference in thermal expansion between the holder 7 and the ultrasonic element 8 in the ultrasonic wave emission direction can be canceled (reduced).
ここで、超音波素子８の厚さ寸法をｔ１とし、収納室７
ａ内のワッシャ６と底面７ｂとの間の寸法をｔ２とする
と、押え部材９の高さ寸法ｔ２−ｔ１は次式で求まる。Here, the thickness dimension of the ultrasonic element 8 is t 1 , and the storage chamber 7
When the dimension between the washer 6 and the bottom surface 7b in a and t 2, the height t 2 -t 1 of the pressing member 9 is determined by the following equation.
上記(1)式より押え部材９の高さ寸法ｔ２−ｔ１を決め
ることにより温度変化があっても超音波素子８への押圧
力は一定に保たれる。 (1) pressing force even when the temperature changes to the ultrasonic element 8 by determining the height t 2 -t 1 of the pressing member 9 from the equation is kept constant.
尚、ワッシャ１３、さらばね１２、及び絶縁材１１の熱
膨脹は無視できるものである。The thermal expansion of the washer 13, the belleville spring 12, and the insulating material 11 can be ignored.
従って、例えば蒸気等の高温流体の流量を計測するとき
ホルダ７の底面７ｂが直接流体に接するため、ホルダ７
は超音波素子８よりも大きく熱膨脹することになる。し
かるに、超音波素子８を押える押え部材９がホルダ７よ
りも大きく膨脹するため、超音波素子８は底面７ｂに当
接したまま保持される。Therefore, when measuring the flow rate of a high temperature fluid such as steam, the bottom surface 7b of the holder 7 is in direct contact with the fluid.
Will expand to a greater extent than the ultrasonic element 8. However, since the pressing member 9 that presses the ultrasonic element 8 expands more than the holder 7, the ultrasonic element 8 is held in contact with the bottom surface 7b.
従って、温度変化があった場合、超音波の放射方向にお
けるホルダ７の熱膨脹量と超音波素子８及び押え部材９
の熱膨脹量とが同一になるように構成されているので、
温度変化により超音波素子８やホルダ７が伸縮しても押
え部材９が超音波素子８とホルダ７との熱膨脹差を吸収
してさらばね１２による押圧力を一定に保つことが可能
となり、超音波素子８の特性が温度変化に拘わらず安定
する。Therefore, when there is a temperature change, the thermal expansion amount of the holder 7 in the direction of the ultrasonic wave emission, the ultrasonic element 8 and the pressing member 9
Since it is configured to have the same thermal expansion amount as
Even if the ultrasonic element 8 or the holder 7 expands or contracts due to the temperature change, the pressing member 9 can absorb the difference in thermal expansion between the ultrasonic element 8 and the holder 7, and can keep the pressing force of the flat spring 12 constant. The characteristics of the acoustic wave element 8 are stable regardless of temperature changes.
そのため、高温流体の流量を計測する際でも、超音波素
子８はホルダ７との熱膨脹差による影響をほとんど受け
ることがない。又、押え部材９と超音波素子８とを合せ
た熱膨脹変位量がホルダ７の熱膨脹変位量と異なり若干
の誤差があった場合、この誤差はさらばね１２によって
吸収される。従って、超音波素子８を押圧するさらばね
１２は上記誤差を補正するだけの弾性変位量を有してい
れば良いので、コンパクトな形状で良い。そのため、超
音波センサ６は全体的にコンパクトな構成であるにも拘
らず、温度変化に対応して常に略一定の押圧力で超音波
素子８がホルダ７内に保持される構造となっている。Therefore, even when measuring the flow rate of the high temperature fluid, the ultrasonic element 8 is hardly affected by the difference in thermal expansion with the holder 7. Further, when the thermal expansion displacement amount of the pressing member 9 and the ultrasonic element 8 is different from the thermal expansion displacement amount of the holder 7, and there is some error, this error is absorbed by the belleville spring 12. Therefore, the belleville spring 12 that presses the ultrasonic element 8 only needs to have an elastic displacement amount that corrects the above-mentioned error, and thus can have a compact shape. Therefore, although the ultrasonic sensor 6 has a compact structure as a whole, the ultrasonic element 8 is always held in the holder 7 with a substantially constant pressing force in response to a temperature change. .
尚、上記実施例ではホルダ７が直接流体に接する構成と
したが、これに限らず、例えばコーンと呼ばれる合成樹
脂製等の取付部材あるいは流量計本体に底面が薄肉とさ
れた取付凹部を設け、これらの取付部材，取付凹部にホ
ルダ７を挿入するようにしても良い。In the above embodiment, the holder 7 is in direct contact with the fluid. However, the present invention is not limited to this. For example, a mounting member made of synthetic resin called a cone or the flowmeter body is provided with a mounting recess having a thin bottom surface, The holder 7 may be inserted into these mounting members and mounting recesses.
又、上記実施例ではさらばねを用いたが、これ以外にコ
イルばね等を使用しても良いのは勿論である。又、押え
部材９の材質は快削黄銅に限らずホルダ７より熱膨脹率
の大きい材質であれば良い。さらに、上記実施例では渦
流量計に用いられる超音波センサとして説明したが、こ
れに限らず、他の装置にも適用できるのは勿論である。Further, although the flat spring is used in the above-mentioned embodiment, it goes without saying that a coil spring or the like may be used instead. Further, the material of the pressing member 9 is not limited to the free-cutting brass, and any material having a coefficient of thermal expansion larger than that of the holder 7 may be used. Furthermore, although the ultrasonic sensor used in the vortex flowmeter has been described in the above embodiment, it is needless to say that the present invention can be applied to other devices as well.
考案の効果 上述の如く、本考案になる超音波センサは、温度変化が
あった場合、超音波の放射方向におけるホルダの熱膨張
量と超音波素子及び押え部材の熱膨張量とが同一になる
ように構成されているので、温度変化により超音波素子
やホルダが伸縮しても押え部材が超音波素子とホルダと
の熱膨張差を吸収してばね部材による押圧力を一定に保
つことが可能となり、超音波素子の特性を温度変化に拘
わらず安定させることができる。そのため、より広い温
度範囲での使用ができ、経時的な環境の変化に対しても
常に保持できるので周波数特性を安定に維持することが
できる。しかも、長いコイルばね等を不要にできるの
で、全体形状をコンパクトな構成にでき、従って、取付
スペースの限られた装置等に使用するのに好適である等
の特長を有する。Effect of the Invention As described above, in the ultrasonic sensor according to the present invention, when the temperature changes, the thermal expansion amount of the holder and the thermal expansion amount of the ultrasonic element and the pressing member in the ultrasonic radiation direction become the same. With this structure, even if the ultrasonic element or holder expands or contracts due to temperature change, the pressing member can absorb the difference in thermal expansion between the ultrasonic element and the holder and keep the pressing force of the spring member constant. Therefore, the characteristics of the ultrasonic element can be stabilized regardless of temperature changes. Therefore, it can be used in a wider temperature range and can be constantly maintained against changes in the environment over time, so that the frequency characteristics can be stably maintained. Moreover, since a long coil spring or the like can be dispensed with, the overall shape can be made compact, and therefore, it is suitable for use in a device having a limited mounting space.
第１図は本考案になる超音波センサの一実施例を適用さ
れた渦流量計の横断面図、第２図は本考案の要部を説明
するための縦断面図である。 １……渦流量計、４……流量計本体、５……渦発生体、
６……超音波センサ、７……ホルダ、８……超音波素
子、９……押え部材、１０……固定部材、１２……さら
ばね、１７……リード線。FIG. 1 is a transverse sectional view of a vortex flowmeter to which an embodiment of an ultrasonic sensor according to the present invention is applied, and FIG. 2 is a vertical sectional view for explaining a main part of the present invention. 1 ... Vortex flowmeter, 4 ... Flowmeter main body, 5 ... Vortex generator,
6 ... Ultrasonic sensor, 7 ... Holder, 8 ... Ultrasonic element, 9 ... Holding member, 10 ... Fixing member, 12 ... Belleville spring, 17 ... Lead wire.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭57−149918（ＪＰ，Ａ) 特開 昭48−101166（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-57-149918 (JP, A) JP-A-48-101166 (JP, A)
Claims (1)
部の底部に前記超音波素子が当接する振動面を有するホ
ルダと、 超音波の放射方向における該ホルダと前記超音波素子と
の熱膨張差を減少する熱膨張率を有し、前記挿入部に挿
入されて前記超音波素子を前記振動面との間で挟持する
ように前記超音波素子に当接する押え部材と、 該押え部材を介して前記超音波素子を前記ホルダの振動
面に押圧するばね部材と、 よりなる超音波センサ。1. An ultrasonic element for transmitting or receiving an ultrasonic wave, an insertion section into which the ultrasonic element is inserted, and a vibrating surface with which the ultrasonic element abuts, at the bottom of the insertion section. The holder has a coefficient of thermal expansion that reduces a difference in thermal expansion between the holder and the ultrasonic element in the direction of emission of ultrasonic waves, and the ultrasonic element is inserted into the insertion portion to move the ultrasonic element between the vibrating surface. An ultrasonic sensor comprising: a holding member that abuts against the ultrasonic element so as to sandwich it; and a spring member that presses the ultrasonic element against the vibrating surface of the holder via the holding member.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1988066389U JPH0618245Y2 (en) | 1988-05-20 | 1988-05-20 | Ultrasonic sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1988066389U JPH0618245Y2 (en) | 1988-05-20 | 1988-05-20 | Ultrasonic sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01168825U JPH01168825U (en) | 1989-11-28 |
| JPH0618245Y2 true JPH0618245Y2 (en) | 1994-05-11 |
Family
ID=31291795
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1988066389U Expired - Lifetime JPH0618245Y2 (en) | 1988-05-20 | 1988-05-20 | Ultrasonic sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0618245Y2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007292762A (en) * | 2006-04-26 | 2007-11-08 | Thermo Fisher Scientific Inc | Transducer assembly |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008033098C5 (en) * | 2008-07-15 | 2016-02-18 | Krohne Ag | ultrasound transducer |
| CN116625445B (en) * | 2023-07-26 | 2023-09-22 | 上海中核维思仪器仪表股份有限公司 | Gas ultrasonic flowmeter |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3771117A (en) * | 1972-03-01 | 1973-11-06 | Westinghouse Electric Corp | Transducer installation |
| JPS5757312U (en) * | 1980-09-22 | 1982-04-03 | ||
| JPS57149918A (en) * | 1981-03-12 | 1982-09-16 | Kawaguchiko Seimitsu Kk | Ultrasonic flow meter |
-
1988
- 1988-05-20 JP JP1988066389U patent/JPH0618245Y2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007292762A (en) * | 2006-04-26 | 2007-11-08 | Thermo Fisher Scientific Inc | Transducer assembly |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01168825U (en) | 1989-11-28 |
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