JPH03282217A - Semiconductor type current meter - Google Patents
Semiconductor type current meterInfo
- Publication number
- JPH03282217A JPH03282217A JP8247290A JP8247290A JPH03282217A JP H03282217 A JPH03282217 A JP H03282217A JP 8247290 A JP8247290 A JP 8247290A JP 8247290 A JP8247290 A JP 8247290A JP H03282217 A JPH03282217 A JP H03282217A
- Authority
- JP
- Japan
- Prior art keywords
- cantilever
- fluid
- flow
- measured
- force
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000004065 semiconductor Substances 0.000 title claims abstract description 11
- 239000012530 fluid Substances 0.000 claims abstract description 17
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 6
- 239000000758 substrate Substances 0.000 claims abstract description 5
- 238000000926 separation method Methods 0.000 claims description 13
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 3
- 229910052710 silicon Inorganic materials 0.000 abstract description 3
- 239000010703 silicon Substances 0.000 abstract description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 238000000034 method Methods 0.000 description 5
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 230000003068 static effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は半導体式流速計に関し、更に詳しくは、管路内
の流速測定に適した小形で取扱いが容易な半導体式流速
計に関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a semiconductor type current meter, and more particularly to a small and easy-to-handle semiconductor type current meter suitable for measuring flow velocity in a pipe.
〈従来の技術〉
従来から、管路内の流速測定にあたっては、熱線式やピ
トー管式等が用いられている。<Prior Art> Conventionally, a hot wire method, a pitot tube method, etc. have been used to measure the flow velocity in a pipe.
熱線式流速計は電流で加熱されている白金線を流体にさ
らすと熱が奪われて温度が下がって白金線の電気抵抗か
減少することを利用したものであり、主に気体の流速測
定に用いられている。具体的には、加熱電圧を一定に保
っておいて白金線の抵抗値変化に起因する不平衡電流の
変化から流速を求める定電圧方式と、白金線の温度を一
定に維持するために印加すべき電流の変化から流速を求
める定温度方式とがある。A hot wire anemometer utilizes the fact that when a platinum wire heated by an electric current is exposed to a fluid, heat is removed, the temperature drops, and the electrical resistance of the platinum wire decreases.It is mainly used to measure the flow velocity of gases. It is used. Specifically, there is a constant voltage method in which the heating voltage is kept constant and the flow velocity is determined from changes in unbalanced current caused by changes in the resistance value of the platinum wire, and a method in which the heating voltage is kept constant and the flow rate is determined from changes in the unbalanced current caused by changes in the resistance value of the platinum wire. There is a constant temperature method that calculates the flow velocity from the change in current.
一方、ピトー管式流速計はベルヌーイの定理を応用した
ものであり、気流や水流の測定に用いられる。例えば両
端が開放されたパイプの一端をＬ字形に曲げて水流中に
浸してその端部を流れの上流側に向けると、流れかせき
とめられてパイプ内部には水流の動圧と静圧を加えた圧
力（総圧）が作用し、パイプ内の水面は水流の水面より
も流速に比例した動圧分たけ高くなる。従って、水流の
場合には両端が開放されて一端かＬ字形に曲げられたパ
イプよりなるピトー管だけて流速を測定できる。なお、
気流の流速（動圧）を測定する場合には、静圧を測定す
る静圧管を組み合わせて総圧と静圧の差圧を求めること
が行われている。On the other hand, a Pitot tube current meter applies Bernoulli's theorem and is used to measure air and water flows. For example, if one end of a pipe with both ends open is bent into an L shape and immersed in a stream of water, with the end facing upstream, the flow is blocked and the dynamic and static pressures of the water flow are applied inside the pipe. The water level in the pipe becomes higher than the water level in the water stream by a dynamic pressure proportional to the flow velocity. Therefore, in the case of water flow, the flow velocity can be measured using only a pitot tube, which is a pipe with both ends open and one end bent into an L-shape. In addition,
When measuring the flow rate (dynamic pressure) of airflow, static pressure tubes for measuring static pressure are combined to determine the differential pressure between the total pressure and the static pressure.
〈発明が解決しようとする課題〉
しかし、これら従来の流速計は、いずれも比較的大形で
、取扱いは簡単ではなく、価格も高いという問題がある
。<Problems to be Solved by the Invention> However, all of these conventional current velocity meters have problems in that they are relatively large, are not easy to handle, and are expensive.
本発明はこのような点に着目してなされたものであり、
その目的は、小形で軽量で取扱いが容易で安価な半導体
式流速計を提供することにある。The present invention has been made with attention to these points,
The purpose is to provide a semiconductor type current meter that is small, lightweight, easy to handle, and inexpensive.
く課題を解決するための手段〉
上記課題を解決する本発明は、
半導体基板よりなるカンチレバーと、
該カンチレバーの一端近傍の表面に配設されたピエゾ抵
抗素子と、
該ピエゾ抵抗素子近傍のカンチレバーの端部に配設され
た流れ剥離体とを具備し、
前記カンチレバーを流れ剥離体か上流側に位置するよう
にして被測定流体の流れ方向に沿って配置したことを特
徴とするものである。Means for Solving the Problems> The present invention to solve the above problems comprises: a cantilever made of a semiconductor substrate; a piezoresistive element disposed on the surface near one end of the cantilever; and a flow separation body disposed at an end, the cantilever being disposed along the flow direction of the fluid to be measured so as to be located upstream of the flow separation body.
く作用〉
本発明の半導体式流速計によれば、カンチレバーは被測
定流体からの力を受け、ピエゾ抵抗素子はその力を検出
する。Effects> According to the semiconductor current meter of the present invention, the cantilever receives force from the fluid to be measured, and the piezoresistive element detects the force.
これにより、ピエゾ抵抗素子の出力信号から被測定流体
の流速を求めることができる。Thereby, the flow velocity of the fluid to be measured can be determined from the output signal of the piezoresistive element.
〈実施例〉
以下、図面を参照して本発明の実施例を詳細に説明する
。<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
第１図は本発明の一実施例の構成図、第２図は第１図の
簡略断面図、第３図は第１図の圧力分布を示している。FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a simplified sectional view of FIG. 1, and FIG. 3 shows the pressure distribution of FIG. 1.
図において、シリコン基板よりなるカンチレバー１の一
端近傍の表面にはブリッジを構成するように複数のピエ
ゾ抵抗素子（ゲージ）２が配設され、該ピエゾ抵抗素子
２近傍のカンチレバー１の端部には例えばガラスで構成
された流れ剥離体３が配設されている。該カンチレバー
１は異方性エツチングで形成されるものであり、流れ剥
離体３か上流側に位置するようにして被測定流体の流れ
方向に沿って例えばハーメチック端子が植設されたステ
ンレススチールよりなる支持体４を介して管５の底面に
配置されている。流れ剥離体３や支持体４はカンチレバ
ー１に陽極接合や低融点カラス等で接合される。なお、
支持体４はカンチレバー１の両側近傍を支持するように
形成されていて、被測定流体はカンチレバー１の下面も
流れるようになっている。管内５における被測定流体の
深さＤと流れ剥離体３とカンチレバー１と支持体４を重
ね合わせた高さＨの関係は、Ｈ（Ｄを満たすようにする
。In the figure, a plurality of piezoresistive elements (gauges) 2 are arranged on the surface near one end of a cantilever 1 made of a silicon substrate so as to form a bridge, and the end of the cantilever 1 near the piezoresistive elements 2 is A flow separation body 3 made of glass, for example, is provided. The cantilever 1 is formed by anisotropic etching, and is made of stainless steel with, for example, a hermetic terminal implanted along the flow direction of the fluid to be measured so as to be located upstream of the flow separation body 3. It is arranged on the bottom surface of the tube 5 via the support 4. The flow separation body 3 and the support body 4 are bonded to the cantilever 1 by anodic bonding, low melting glass, or the like. In addition,
The support body 4 is formed to support the vicinity of both sides of the cantilever 1, and the fluid to be measured also flows through the lower surface of the cantilever 1. The relationship between the depth D of the fluid to be measured in the pipe 5 and the height H where the flow separation body 3, the cantilever 1, and the support body 4 are superimposed is made to satisfy H(D.
このような構成において、カンチレバー１は被測定流体
からの力を受けてピエゾ抵抗素子２はその力を検出する
ことになり、ピエゾ抵抗素子２の出力信号から被測定流
体Ｆの流速を求めることができる。In such a configuration, the cantilever 1 receives a force from the fluid to be measured, and the piezoresistive element 2 detects the force, and the flow velocity of the fluid to be measured F can be determined from the output signal of the piezoresistive element 2. can.
被測定流体の流れの一部は流れ剥離体３により全体の流
れの中から剥離させられる。剥離させられた流れの先端
は一定距離Ωたけ流速Ｖて移動した後、カンチレバー１
の表面に付着する。この距離ｇは流速Ｖに比例する。す
なわち、
ｇ代ｖ、 、’、Ω−に１ ・■ ・・・
（１）（Ｋ ＋ 定数）
の関係か成立する。A part of the flow of the fluid to be measured is separated from the entire flow by the flow separation body 3. The tip of the separated flow moves a certain distance Ω at a flow velocity V, and then moves to the cantilever 1.
adheres to the surface of This distance g is proportional to the flow velocity V. That is, 1 for g-cost v, , ', Ω- ・■ ...
The relationship (1) (K + constant) holds true.
そして、第３図に示すように、カンチレバー１の流れ剥
離体３からほぼΩ／２の位置には力Ｆか作用する。この
力Ｆは次式で表される。As shown in FIG. 3, a force F acts on the cantilever 1 at a position approximately Ω/2 from the flow separation body 3. This force F is expressed by the following formula.
Ｆ ＝ ｆ （Ｐｕ−Ｐｄ）ｄｓ
−に２ （１／２） ｐＶ２Ｓ
＝に２（１／２） ｐＶ２ｂ Ｄ ”Ｖ３−（２）Ｋ２
・定数
Ｐｕ：距離Ωの間の上面圧力
Ｐｄ 距離Ωの間の下面圧力
Ｓ：剥離領域の面積（−ｂ−ｉｔ）
ρ・流体密度
二〇力Ｆにより、カンチレバー１の固定端近傍のピエゾ
抵抗素子２には次式のモーメントＭ及び応力σが作用す
る。F = f (Pu-Pd)ds - 2 (1/2) pV2S = 2 (1/2) pV2b D ''V3 - (2) K2
・Constant Pu: Top surface pressure Pd between distance Ω Bottom surface pressure between distance Ω S: Area of separation region (-b-it) ρ・Fluid density 20 Due to force F, piezo resistance near the fixed end of cantilever 1 A moment M and a stress σ expressed by the following equations act on the element 2.
Ｍ＝（Ｊ／２）Ｆ
σ−（Ｍ／Ｉ） （ｔ／２）
−（３１／ｂｔ２）Ｆ ・・・
（３）Ｉ：断面２次モーメント
ゲージ出力Ｅは応力σに比例する
これにより、
ことになる。M=(J/2)F σ-(M/I) (t/2)-(31/bt2)F...
(3) I: The cross-sectional moment of inertia gauge output E is proportional to the stress σ.
（Ｌ） 、 （２） 、 （３）式より、σｃ１：１・
ＦＣｗ−Ｖ４
になる。From equations (L), (2), and (3), σc1:1・
It becomes FCw-V4.
一方、
ゲージ出力ＥはＥｃｘ：σなので、
Ｖ ｏＣ’ ｆｆ −Ｋ ３’ ｆｆ ・
（４）Ｋ３ ：定数
になる。On the other hand, since the gauge output E is Ecx:σ, V oC' ff -K 3' ff ・
(4) K3: Becomes a constant.
すなわち、流速Ｖはゲージ出力Ｅの４乗根に比例し、ゲ
ージ出力Ｅから流速を求めることができる。なお、Ｋ、
、に２．に、などの定数は予め校正して求めておく。ま
た、流れ剥離体３の高さｈや流れの方向に沿った長さＣ
などは最適値を選ぶようにし、ｈは０を含むものとする
。That is, the flow velocity V is proportional to the fourth root of the gauge output E, and the flow velocity can be determined from the gauge output E. Furthermore, K,
, to 2. Calibrate and find constants such as and in advance. In addition, the height h of the flow separation body 3 and the length C along the flow direction
etc., the optimal values are selected, and h includes 0.
このように構成される流速計は、小形で取扱いは容易で
ある。そして、半導体製造プロセスで大量生産できるの
で、安価である。The current meter configured in this manner is small and easy to handle. Moreover, since it can be mass-produced using a semiconductor manufacturing process, it is inexpensive.
第４図は本発明の他の実施例を示す断面図であり、カン
チレバー１の下面には被測定流体が流れないようにカン
チレバー１の下面を幅方向に支持体４で塞いだ構成例を
示している。FIG. 4 is a sectional view showing another embodiment of the present invention, and shows an example of a configuration in which the lower surface of the cantilever 1 is closed in the width direction with a support 4 so that the fluid to be measured does not flow on the lower surface of the cantilever 1. ing.
この場合の力Ｆは次式で表される。The force F in this case is expressed by the following equation.
Ｆ −ＩＰｏ −（Ｐ ｏ −に＋ （１／２） ｐＶ
２）ｌｂ ＩＩ ’＝に＋ （１／２） ｐＶ２ｂ Ｉ
Ｉ ’＝ Ｋ １（１／２） ｐＶ２ｂ（Ｌ−１）
・・・（５）そして、ゲージ出力Ｅは、
Ｅｏｃｃｙｃ＜ＭｏｅＰｌｊ＋（Ｒ’ ／２）１ｏｅＶ
２（Ｌ−ｊ）化＋１）
■Ｖ２ （Ｌ２−に２ｖ２）
から、
Ｅ−−に２Ｖ’ ＋に、 ｖ２ −（８）
になり、第１図の構成と同様に、ゲージ出力Ｅから流速
Ｖを求めることができる。F - IPo - (Po - + (1/2) pV
2) lb II' = + (1/2) pV2b I
I'=K1(1/2) pV2b(L-1)
...(5) And the gauge output E is Eoccyc<MoePlj+(R'/2)1oeV
2(L-j) conversion +1) ■V2 (2v2 to L2-) to 2V' + to E--, v2 -(8)
As in the configuration shown in FIG. 1, the flow velocity V can be determined from the gauge output E.
また、ピエゾ抵抗素子とともにカンチレバーの固定部分
に信号処理回路を形成することにより、信号処理された
出力を得ることができる。Furthermore, by forming a signal processing circuit on the fixed portion of the cantilever together with the piezoresistive element, a signal-processed output can be obtained.
〈発明の効果〉
以上詳細に説明したように、本発明によれば、小形で軽
量で取扱いが容易で安価な半導体式流速計を提供するこ
とかできる。<Effects of the Invention> As described above in detail, according to the present invention, it is possible to provide a semiconductor type current meter that is small, lightweight, easy to handle, and inexpensive.
第１図は本発明の一実施例の構成図、 第２図は第１図の簡略断面図、 第３図は第１図の圧力分布説明図、 第４図は本発明の他の実施例の要部の断面図である。 １・・・シリコンカンチレバー ２・・・ピエゾ抵抗素子（ゲージ） ３・・・流れ剥離体 ４・・・支持体 FIG. 1 is a configuration diagram of an embodiment of the present invention, Figure 2 is a simplified cross-sectional view of Figure 1; Figure 3 is an explanatory diagram of the pressure distribution in Figure 1, FIG. 4 is a sectional view of a main part of another embodiment of the present invention. 1... Silicon cantilever 2... Piezoresistive element (gauge) 3...Flow separation body 4...Support
Claims (1)
抗素子と、 該ピエゾ抵抗素子近傍のカンチレバーの端部に配設され
た流れ剥離体とを具備し、 前記カンチレバーを流れ剥離体が上流側に位置するよう
にして被測定流体の流れ方向に沿って配置したことを特
徴とする半導体式流速計。[Scope of Claims] A cantilever made of a semiconductor substrate, a piezoresistive element disposed on the surface near one end of the cantilever, and a flow separation body disposed at the end of the cantilever near the piezoresistive element. A semiconductor current meter, comprising: the cantilever disposed along the flow direction of the fluid to be measured with the flow separation body positioned on the upstream side.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8247290A JPH03282217A (en) | 1990-03-29 | 1990-03-29 | Semiconductor type current meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8247290A JPH03282217A (en) | 1990-03-29 | 1990-03-29 | Semiconductor type current meter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03282217A true JPH03282217A (en) | 1991-12-12 |
Family
ID=13775453
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8247290A Pending JPH03282217A (en) | 1990-03-29 | 1990-03-29 | Semiconductor type current meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03282217A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS629222A (en) * | 1985-07-03 | 1987-01-17 | エル・エム・ゲ−・エレクトロニク・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング | Measuring device for flow rate of fluid |
| JPH0198926A (en) * | 1987-10-12 | 1989-04-17 | Yokogawa Electric Corp | Mass flowmeter |
-
1990
- 1990-03-29 JP JP8247290A patent/JPH03282217A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS629222A (en) * | 1985-07-03 | 1987-01-17 | エル・エム・ゲ−・エレクトロニク・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング | Measuring device for flow rate of fluid |
| JPH0198926A (en) * | 1987-10-12 | 1989-04-17 | Yokogawa Electric Corp | Mass flowmeter |
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