JPH0755461Y2 - Vortex detector - Google Patents

Description

【考案の詳細な説明】 技術分野 本考案は、渦発生体両側面に発生する渦変動圧力を渦発
生体内に導入し、この渦変動圧力を渦発生体内に別体的
に嵌挿して検知する渦検出器であり、特に高温流体用の
渦検出器の構造に関する。TECHNICAL FIELD The present invention introduces vortex fluctuating pressure generated on both side surfaces of a vortex generator into a vortex generator and detects the vortex fluctuating pressure separately inserted into the vortex generator. A vortex detector, and more particularly to the structure of a vortex detector for high temperature fluids.

従来技術 渦流量計は、周知のごとく、渦発生体から剥離するカル
マン渦が流速または流量に比例することを利用したもの
であり、渦の発生を電気信号変換する渦検出器を具備し
ている。渦検出器には渦発生体と別体的に装着するもの
と、渦発生体と一体的に装着するものとがある。通常、
小形な流量計とするために後者を採用するものが多い。
第４図は、その一例である。（ａ）図は流れ方向におけ
る断面図をしめしたもので、図において100は流管、110
は渦発生体で、（ｂ）図の矢視Ｘ−Ｘ断面にしめすごと
く、例えば、断面三角形状をしている。該渦発生体110
には軸に沿って凹部111が穿設されており、該凹部111に
対して、渦発生体110の両側面から渦変動圧力を導入す
る下部圧力導入孔112,112および上部圧力導入孔113,113
が連通している。１は導入された渦の変動圧力を検知す
る検出要素である円筒状の振動子で、下端に受圧板11を
配設し、フランジ12により流管100に螺着され片持支持
される。振動子１の円筒外面と流管100および渦発生体
凹部111とは僅かの隙をもっており、渦変動圧力を受け
て図において左右に振動可能となっている。振動は振動
子内部14に嵌挿した板状の弾性母材２の両側面に金ペー
スト等で貼着した圧電素子３の圧電信号として検知され
導線91,92により外部増幅器（図示せず）に導出され
る。この際振動子１の振動を正確に圧電素子３に伝達す
る為に低融点の釦ガラス等のモールド材1aにより絶縁さ
れ振動子１と圧電素子３とを密に封着される。このモー
ルドにより受圧された渦変動圧力は忠実に圧電信号に変
換され小流における微圧渦も検出可能となる。2. Description of the Related Art As is well known, a vortex flowmeter utilizes the fact that a Karman vortex separated from a vortex generator is proportional to a flow velocity or a flow rate, and is equipped with a vortex detector that converts an electrical signal into vortex generation. . The vortex detector includes one that is mounted separately from the vortex generator and one that is mounted integrally with the vortex generator. Normal,
The latter is often used to make a small flow meter.
FIG. 4 shows an example. (A) The figure shows a cross-sectional view in the flow direction, where 100 is a flow tube and 110 is a flow tube.
Is a vortex generator, and has a triangular cross section, for example, as shown in the XX cross section in the arrow in FIG. The vortex generator 110
A concave portion 111 is formed along the axis in the lower portion, and lower pressure introducing holes 112, 112 and upper pressure introducing holes 113, 113 for introducing vortex fluctuation pressure into the concave portion 111 from both side surfaces of the vortex generator 110 are formed.
Are in communication. Reference numeral 1 denotes a cylindrical vibrator which is a detection element for detecting the fluctuating pressure of the introduced vortex. A pressure receiving plate 11 is arranged at the lower end, and a flange 12 is screwed to the flow tube 100 to support it in a cantilever manner. There is a slight gap between the outer surface of the cylinder of the vibrator 1 and the flow tube 100 and the vortex generator recess 111, and it is possible to vibrate to the left and right in the figure due to vortex fluctuation pressure. The vibration is detected as a piezoelectric signal of the piezoelectric element 3 adhered to the both sides of the plate-shaped elastic base material 2 fitted in the vibrator inside 14 with gold paste or the like, and is transmitted to the external amplifier (not shown) by the conductors 91 and 92. Derived. At this time, in order to accurately transmit the vibration of the vibrator 1 to the piezoelectric element 3, the vibrator 1 and the piezoelectric element 3 are tightly sealed by being insulated by the molding material 1a such as button glass having a low melting point. The vortex fluctuating pressure received by this mold is faithfully converted into a piezoelectric signal, and even a slight pressure vortex in a small flow can be detected.

従来技術の問題点 叙上の従来技術における渦検出器においては、渦検出器
は渦発生体の大きさ、形状を問わず、同一の渦検出器を
適用でき、且つ渦検出器を交換すればよいので補修も簡
易である利点を有するが高温流体を計測する場合、高温
においても絶縁低下の起きないモールド材で、しかも振
動子、母材、圧電素子等の主検出要素における熱膨張差
による脱落等を防止できる熱特性のものは見当らず、こ
の結果高温流体計測には適さないという問題点があっ
た。またモールド材なしで圧電素子を振動子内に装着す
ると、長期間の使用で圧電素子は母材から剥離するとい
う他の問題点があった。Problems of the Prior Art In the vortex detector in the above conventional technology, the same vortex detector can be applied regardless of the size and shape of the vortex generator, and if the vortex detector is replaced, Since it is good, it has the advantage of being easy to repair, but when measuring high-temperature fluid, it is a mold material that does not cause insulation deterioration even at high temperatures, and it is detached due to the difference in thermal expansion of the main detection elements such as the vibrator, base material, and piezoelectric element. There is no thermal property that can prevent such problems, and as a result, there is a problem that it is not suitable for high temperature fluid measurement. Further, when the piezoelectric element is mounted in the vibrator without using the molding material, there is another problem that the piezoelectric element is separated from the base material after long-term use.

問題点解決の手段 本考案は、従来方式の特徴を生かし、特に熱的問題点を
解決することを目的としてなされたもので、その要旨と
するものは渦発生体の軸方向に穿設された凹部に連通す
る圧力導入孔を介して導入される渦変動圧力を検知する
渦検出器において、前記凹部に同軸に挿通し、片持支持
される円筒状の振動子内に、圧力導入孔に面して挿着さ
れる板状で両端部を円柱とした弾性母材と、該弾性母材
の両面に接合される短冊状の圧電素子と、該圧電素子の
外面に接合される電極板と、前記弾性母材、圧電素子お
よび電極板を接合した両側面に当接するセラミックス板
とを金属細線で巻回し一体的に固着した検出要素を配設
し、振動子と検出要素とを前記弾性母材両端部円柱に嵌
着された絶縁材環状体を介して両持固定し、両持固定を
各々の自由端側接合面をテーパ面とし支持側絶縁材環状
体端面を環状板ばねにより前記テーパ面を押圧固着する
ことを特徴とする渦検出器である。Means for Solving Problems The present invention was made to take advantage of the characteristics of the conventional method and particularly to solve the thermal problems. The gist of the invention is to pierce the vortex generator in the axial direction. In a vortex detector for detecting a vortex fluctuation pressure introduced through a pressure introducing hole communicating with the recess, a cylindrical vibrator which is coaxially inserted into the recess and is cantilevered supports a surface of the pressure introducing hole. A plate-shaped elastic base material having both ends cylindrically inserted and attached, strip-shaped piezoelectric elements bonded to both surfaces of the elastic base material, and an electrode plate bonded to the outer surface of the piezoelectric element, The elastic base material, a piezoelectric element, and a ceramics plate that is in contact with both side surfaces of the electrode plate that are in contact with each other are wound with a fine metal wire and integrally fixed to the detection element, and the transducer and the detection element are attached to the elastic base material. Both ends are fixed via the insulating material annular body fitted to the cylinders at both ends. In the vortex detector, each free end side joint surface is a taper surface, and the support side insulating material annular body end surface is pressed and fixed to the tapered surface by an annular leaf spring.

実施例 第１図は、本考案の渦検出器の構造をしめす流れ方向か
らみた縦断面図であり、第４図の渦検出器と共通する要
素には同一符号を付して説明を省く。尚図において
（ｂ），（ｃ），（ｄ）図は各々矢視,B−B,C−C,D−Ｄ
を拡大して図示したものである。第１図において母材２
は下端部21および上端部22を円柱状にして、該母材下端
部21,上端部22を振動子１に対する両持固定部とするも
ので、円柱状外周には各々21a,22aの螺刻してある。セ
ラミックス等の高温絶縁材の下部環状体16および上部環
状体17を各々螺着している。母材２の平板部両面には従
来技術同様圧電素子（短冊状）３を金ペースト等で貼着
しているが、各々の圧電素子３の外面には電極板４を当
接している。叙上の母材２、圧電素子３および電極板４
を順次積重ね、積重ねてなる柱状体の両側面にはセラミ
ックス板５を当接して母材２と両圧電素子3,3とを絶縁
し、その外周を金属細線６で巻回し、電極板４を圧電素
子３に圧接している。この際、電極板４が金属細線６の
熱膨張による弛緩により圧電素子３と離間し接触不良と
なるのを防ぐため要極板４は第３図にしめすように縦方
向に凹状溝41を形成するように折曲し、この凹状溝41を
支点とするばね力を与えるように平面に対し所定角度θ
をもっている。この角度によるばね作用のため、金属細
線６の熱膨張による弛緩分は吸収され、常に電極板４は
圧電素子３に圧接している。第２図は、母材2,圧電素子
3,電極板４およびセラミックス板５の組立構成をしめす
斜視図であり、第１図（ａ）図はこれら検出要素10の組
立後の断面図をしめす。叙上の検出要素10と振動子と
は、下部環状体16および上部環状体17部とで両持式に固
定される。即ち、下部環状体16の外周面をテーパ面と
し、このテーパ面を振動子内筒14の底部に設けたテーパ
面15とを底面に僅かの隙をおいて接合し、この接合面を
フランジ12に嵌挿された上部環状体17の端面を板ばね７
により下方に向けて加圧することにより圧接固着するも
のである。板ばね７は（Ｃ）図にしめす平面図の如く環
状鍔7bを有する円形皿状の板ばね材内に放射状に複数の
切欠を設けて折曲して、この折曲片7a,7a…にばね作用
を与え、この折曲片7a,7a…の端部を上部環状体17の端
面に当接し環状鍔7bを保護筒８の鍔81により押圧固定し
ている。保護筒８はフランジ12上面の環状鍔121におい
てＷに示す位置で溶着される。上部環状体17は第１図
（ｄ）図に示すように検出要素10を位置決めする為の溝
17aと第１リード91を挿通する挿通孔91aを穿孔してい
る。尚圧電信号は電極板４と導通する金属細線６を接続
する第１リード91および母材２を他の電極とする第２リ
ード92より出力され、出力コード93より外部に伝送され
る。叙上の検出器は流管100に取付孔13を介して螺着さ
れ、フランジ12を固定点とし受圧板11を自由端とするカ
ンチレバとなり、該カンチレバに作用する渦変動圧力
を、下部，上部環状体16,17で両持支持された母材２の
曲げひずみに変換し、温度に影響されることなくこの曲
げひずみを忠実に圧電素子３に伝える。Embodiment FIG. 1 is a vertical cross-sectional view showing the structure of the vortex detector of the present invention as seen from the flow direction. Elements common to those of the vortex detector of FIG. In addition, in the figures, (b), (c), and (d) are respectively shown by arrows, BB, CC, DD.
Is an enlarged view of FIG. Base material 2 in FIG.
Has a lower end portion 21 and an upper end portion 22 which are cylindrical, and the lower end portion 21 and the upper end portion 22 of the base material are both-supported fixing portions for the vibrator 1. The outer periphery of the cylindrical shape is threaded with 21a and 22a, respectively. I am doing it. A lower annular body 16 and an upper annular body 17 made of a high temperature insulating material such as ceramics are screwed to each other. Piezoelectric elements (rectangular strips) 3 are attached to both sides of the flat plate portion of the base material 2 with gold paste or the like as in the prior art, but the electrode plate 4 is in contact with the outer surface of each piezoelectric element 3. Base material 2, piezoelectric element 3 and electrode plate 4
Ceramic plates 5 are brought into contact with both side surfaces of the stacked columnar bodies to insulate the base material 2 and the piezoelectric elements 3, 3 from each other, and the outer circumference thereof is wound with a thin metal wire 6 to form the electrode plate 4. It is pressed against the piezoelectric element 3. At this time, in order to prevent the electrode plate 4 from separating from the piezoelectric element 3 due to the relaxation due to the thermal expansion of the thin metal wire 6 and causing a contact failure, the pole plate 4 has a concave groove 41 formed in the vertical direction as shown in FIG. And a predetermined angle θ with respect to the plane so as to apply a spring force with the concave groove 41 as a fulcrum.
I have Due to the spring action due to this angle, the loosened portion due to the thermal expansion of the metal thin wire 6 is absorbed, and the electrode plate 4 is constantly in pressure contact with the piezoelectric element 3. Figure 2 shows the base material 2 and the piezoelectric element.
3, which is a perspective view showing the assembly structure of the electrode plate 4 and the ceramic plate 5, and FIG. 1 (a) is a sectional view of the detection element 10 after assembly. The above-mentioned detection element (10) and the vibrator are fixed on both sides by a lower annular body (16) and an upper annular body (17). That is, the outer peripheral surface of the lower annular body 16 is a taper surface, and this taper surface is joined to the taper surface 15 provided at the bottom of the vibrator inner cylinder 14 on the bottom surface with a slight gap, and the joint surface is the flange 12 The end surface of the upper annular body 17 fitted in the
By pressurizing downward by, it is fixed by pressure contact. The leaf spring 7 is bent by forming a plurality of notches radially in a circular disc-shaped leaf spring material having an annular collar 7b as shown in the plan view of FIG. A spring action is applied, the ends of the bent pieces 7a, 7a ... Abut on the end surface of the upper annular body 17, and the annular collar 7b is pressed and fixed by the collar 81 of the protective cylinder 8. The protection cylinder 8 is welded at a position indicated by W on the annular flange 121 on the upper surface of the flange 12. The upper annular body 17 is a groove for positioning the detecting element 10 as shown in FIG. 1 (d).
An insertion hole 91a for inserting the 17a and the first lead 91 is bored. The piezoelectric signal is output from the first lead 91 that connects the metal thin wire 6 that is electrically connected to the electrode plate 4 and the second lead 92 that uses the base material 2 as another electrode, and is transmitted to the outside from the output code 93. The above detector is a cantilever screwed to the flow tube 100 through the mounting hole 13 and has a flange 12 as a fixed point and a pressure receiving plate 11 as a free end. The vortex fluctuation pressure acting on the cantilever is detected by the lower and upper portions. It is converted into bending strain of the base material 2 supported on both sides by the annular bodies 16 and 17, and this bending strain is faithfully transmitted to the piezoelectric element 3 without being affected by temperature.

効果 叙上の本考案の渦検出器によれば、渦検出器の外形およ
び寸法等は従来の渦検出器と同様であり、従って渦発生
体の寸法形状によらず同一の渦検出器を適用でき、しか
も簡易に交換できる等の保安上の利点を生かしたまま高
温流体測定においてモールド材の絶縁低下、出力低下に
よるSN比劣化の影響を受けることなく渦信号を出力する
ことができる。しかもモールド材を不要としたため振動
子のカンチレバにおける曲げ剛性も低下し高感度の渦検
出できる。また、検出要素10は金属細線で巻回固着され
ていて、電極板にばね作用を与えているため圧電素子の
貼着不良による出力が不安定になることもなく信頼性の
高い高温用渦検出器を提供できる。Effect According to the vortex detector of the present invention described above, the outer shape and dimensions of the vortex detector are the same as those of the conventional vortex detector. Therefore, the same vortex detector is applied regardless of the size and shape of the vortex generator. The vortex signal can be output without being affected by the deterioration of the insulation of the molding material and the deterioration of the SN ratio due to the decrease of the output in the high temperature fluid measurement while taking advantage of the safety such as the fact that it can be easily replaced. Moreover, since the molding material is not required, the bending rigidity of the cantilever of the vibrator is also reduced, and highly sensitive vortex detection can be performed. Further, since the detection element 10 is wound and fixed with a thin metal wire and exerts a spring action on the electrode plate, the output is not unstable due to a defective attachment of the piezoelectric element, and the vortex detection for high temperature is highly reliable. Can be provided.

【図面の簡単な説明】[Brief description of drawings]

第１図は、本考案の渦検出器の流れ方向からみた縦断面
図、（ｂ），（ｃ），（ｄ）図は各々（ａ）図の矢視Ｂ
−B,C−C,D−Ｄ断面図である。第２図は、検出要素の組
立をしめす構造斜視図、第３図は、電極板の斜視図、第
４図は、従来例を示す図である。 １…振動子、２…母材、３…圧電素子、４…電極板、５
…セラミックス板、６…金属細線、７…板ばね、８…保
護筒、16…下部環状体、17…上部環状体。FIG. 1 is a vertical cross-sectional view of the vortex detector of the present invention viewed from the flow direction, and FIGS. 1 (b), (c), and (d) are views of arrow B of FIG. 1 (a).
It is a B-C-C, DD sectional view. FIG. 2 is a structural perspective view showing the assembly of a detection element, FIG. 3 is a perspective view of an electrode plate, and FIG. 4 is a view showing a conventional example. 1 ... Oscillator, 2 ... Base material, 3 ... Piezoelectric element, 4 ... Electrode plate, 5
... ceramic plate, 6 ... fine metal wire, 7 ... plate spring, 8 ... protective cylinder, 16 ... lower annular body, 17 ... upper annular body.

Claims (2)

【実用新案登録請求の範囲】[Scope of utility model registration request] 【請求項１】渦発生体の軸方向に穿設された凹部に連通
する圧力導入孔を介して導入される渦変動圧力を検知す
る渦検出器において、前記凹部に同軸に挿通し、片持支
持される円筒状の振動子内に、圧力導入孔に面して挿着
される板状で両端部を円柱とした弾性母材と、該弾性母
材の両面に接合される短冊状の圧電素子と、該圧電素子
の外面に接合される電極板と、前記弾性母材、圧電素子
および電極板を接合した両側面に当接するセラミックス
板とを金属細線で巻回し一体的に固着した検出要素を配
設し、振動子と検出要素とを前記弾性母材両端部円柱に
嵌着された絶縁材環状体を介して両持固定し、両持固定
を各々の自由端側接合面をテーパ面とし支持側絶縁材環
状体端面を環状板ばねにより前記テーパ面を押圧固着す
ることを特徴とする渦検出器。1. A vortex detector for detecting vortex fluctuation pressure introduced through a pressure introducing hole communicating with a recess formed in the axial direction of a vortex generator, wherein the vortex detector is coaxially inserted into the recess and cantilevered. A plate-shaped elastic base material with both ends cylindrical, which is inserted into the supported cylindrical vibrator facing the pressure introduction hole, and a strip-shaped piezoelectric element bonded to both sides of the elastic base material. A detection element in which an element, an electrode plate bonded to the outer surface of the piezoelectric element, and a ceramics plate that abuts on both sides of the elastic base material, the piezoelectric element and the electrode plate bonded together are wound by a thin metal wire and integrally fixed. , And the vibrator and the detection element are both-supported and fixed via an insulating material annular body fitted to the cylinders at both ends of the elastic base material. The supporting side insulating material annular body end surface is pressed and fixed to the tapered surface by an annular leaf spring. Vortex detector. 【請求項２】前記において電極板は、短冊形であり、長
手方向に凹状態を形成するごとく折曲し、該凹状溝を支
点とするばね力を与えた請求項１記載の渦検出器。2. The vortex detector according to claim 1, wherein said electrode plate has a strip shape and is bent so as to form a concave state in the longitudinal direction, and a spring force is applied with said concave groove as a fulcrum.