JPH0198935A - Fine pressure sensor - Google Patents

Fine pressure sensor

Info

Publication number
JPH0198935A
JPH0198935A JP25639487A JP25639487A JPH0198935A JP H0198935 A JPH0198935 A JP H0198935A JP 25639487 A JP25639487 A JP 25639487A JP 25639487 A JP25639487 A JP 25639487A JP H0198935 A JPH0198935 A JP H0198935A
Authority
JP
Japan
Prior art keywords
optical fiber
pressure
light
variation
pressure sensor
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
Application number
JP25639487A
Other languages
Japanese (ja)
Inventor
Seiji Nakagome
誠治 中込
Yasuyori Sasaki
康順 佐々木
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nok Corp
Original Assignee
Nok Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nok Corp filed Critical Nok Corp
Priority to JP25639487A priority Critical patent/JPH0198935A/en
Publication of JPH0198935A publication Critical patent/JPH0198935A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To accurately read fine pressure variation by clamping an optical fiber between two corrugated plates almost linearly and measuring the quantity of variation in the quantity of the light of the optical fiber due to pressure application from one corrugated plate side. CONSTITUTION:The upper and lower wave plates 1 and 2 formed of plastic, etc., are so positioned that their one-surface sides engage each other. Then the optical fiber 3 whose core is made of a material with rubber elasticity is clamped and held by their projection parts to constitute a sensor. When pressure is applied 4 to the corrugated plate 1, the optical fiber 3 deforms as shown by 3', 3''... according to the degree of the pressure application. At this time, the light quantity variation rate of the projection light from the optical fiber 3 has light quantity loss based upon the radius of curvature almost irrelevantly to the elongation of the optical fiber 3. Namely, the large light quantity variation rate is indicated as fine variation of the pressure 4. For the purpose, the light quantity variation rate of the projection light is measured by a detector to measure the fine pressure.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、微圧センサに関する。更に詳しくは、微小圧
力変化を簡易に検知することが可能な圧力センサに関す
る。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a low pressure sensor. More specifically, the present invention relates to a pressure sensor that can easily detect minute pressure changes.

〔従来の技術〕[Conventional technology]

従来から、光ファイバを利用した圧力センサがいくつか
示されている。しかしながら、これらはいずれも石英コ
ア光ファイバやプラスチックコア光ファイバを用いて作
られたものであり、光ファイバのゆるやかなたわみによ
る出射光の微小な振幅の変化を読みとったり、ファイバ
径の圧力によるひずみや縮みを振幅の変化や位相の変化
として読みとったり、あるいはひずみを与えない場合の
出射光の位相との差を干渉として読みとったりして、圧
力変化を検知している。
Conventionally, several pressure sensors using optical fibers have been shown. However, these are all made using quartz core optical fibers or plastic core optical fibers, and it is difficult to read minute changes in the amplitude of the emitted light due to gradual bending of the optical fiber, or to detect distortion due to pressure on the fiber diameter. Pressure changes are detected by reading changes in amplitude and phase as changes in amplitude and phase, or by reading the difference between the phase of the emitted light when no distortion is applied as interference.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

こうした方法では、石英コア光ファイバやプラスチック
コア光ファイバが硬く、圧力やひずみに対して大きく変
形しないため、出射光の変化量が少なく、その精度上に
問題がみられた。従って、これらの方法で精度を上げよ
うとする場合には、干渉計や高精度の光量検出器などの
精密な解析装置を必要としている。
In these methods, since quartz core optical fibers and plastic core optical fibers are hard and do not deform significantly under pressure or strain, the amount of change in the emitted light is small, resulting in problems with accuracy. Therefore, in order to improve accuracy using these methods, precise analysis equipment such as an interferometer or a high-precision light amount detector is required.

そこで本発明者らは、微小圧力の変化に対しても出射光
の変化量を大きくすることを検討した結果、ゴム弾性を
有する光ファイバを特定の方法で用いることにより、か
かる課題が効果的に解決されることを見出した。
Therefore, the present inventors investigated ways to increase the amount of change in the output light even in response to minute changes in pressure, and found that by using an optical fiber with rubber elasticity in a specific manner, this problem could be effectively solved. I found a solution.

〔問題点を解決するための手段〕[Means for solving problems]

従って、本発明は微圧センサに係り、この微圧センサは
、互いに噛み合う形状および位置関係にある隔離された
2枚の波状板の間にゴム弾性を有する光ファイバをほぼ
直線状に挟着し、一方の波状板側からの加圧を光ファイ
バの出射光の光量変化量として測定し得るようにしてな
る。
Therefore, the present invention relates to a micro-pressure sensor, in which an optical fiber having rubber elasticity is sandwiched in a substantially straight line between two separated corrugated plates that are shaped and positioned to engage with each other. The pressure applied from the corrugated plate side can be measured as the amount of change in the amount of light emitted from the optical fiber.

本発明に係る微圧センサの一態様は、図面の第1図に正
面図として示されている。即ち、上下2枚の波状板1,
2は、その一方の面同志が互いに噛み合う形状および位
置関係にあり、それらは山部面に沿って光ファイバ3を
挟着し得るように隔離されて、微圧センサを構成してい
る。
One embodiment of a low pressure sensor according to the present invention is shown in a front view in FIG. 1 of the drawings. That is, two upper and lower corrugated plates 1,
2 have a shape and a positional relationship such that one surface thereof meshes with each other, and they are separated so that the optical fiber 3 can be sandwiched along the ridged surface to constitute a low pressure sensor.

波状板としては、プラスチック、その他任意の材質から
形成させることができるが、その谷部の深さは数1程、
全体の厚さは約8〜10mm程であって、上部波状体の
長さが数10mm程度であり、下部波状板の長さが左右
それぞれ一山程度長いようなものを用いることが好まし
い。
The corrugated plate can be made of plastic or any other material, but the depth of the troughs is approximately several 1,
It is preferable to use one in which the overall thickness is about 8 to 10 mm, the length of the upper corrugated body is about several tens of mm, and the length of the lower corrugated plate is about one peak longer on each side.

これら2枚の隔離された波状板の間には、光ファイバ3
が波状板の各山部によって挟着保持され、そこに加圧4
がなされると、加圧の程度に応じて光ファイバは変形3
 ’、 3 ”、・・・する。
Between these two isolated corrugated plates is an optical fiber 3
is held between the peaks of the corrugated plate, and pressure is applied thereto.
When the pressure is applied, the optical fiber deforms 3 depending on the degree of pressure applied.
', 3 '', ....

これに関連して、長さ1m、直径1mmの光ファイバの
中央部分Locmを半径Rの円柱に巻き付けたときの出
射光量をパワーメーターにより測定し。
In connection with this, the amount of light emitted when the central portion Locm of an optical fiber with a length of 1 m and a diameter of 1 mm was wound around a cylinder with a radius of R was measured using a power meter.

光フアイバ曲率半径(R)と光量変化率との関係を求め
るモデル実験を行なった。この結果は、第2図のグラフ
に示される。また、伸びに対する光量変化率の関係を求
め、その結果を第3図のグラフに示した。
A model experiment was conducted to determine the relationship between the radius of curvature (R) of an optical fiber and the rate of change in light amount. The results are shown in the graph of FIG. In addition, the relationship between the rate of change in light amount and the elongation was determined, and the results are shown in the graph of FIG.

これらの結果から、伸びに対しては殆んど光量変化がな
く、第1図に示すような波状板を用いて光ファイバにひ
ずみを加えても、伸びとは殆んど無関係に、曲率半径に
よる光量損失として圧力変化を検知することができる。
These results show that there is almost no change in light intensity with elongation, and even when strain is applied to the optical fiber using a corrugated plate as shown in Figure 1, the radius of curvature changes almost independently of elongation. Pressure changes can be detected as light amount loss due to

かかる性質を有する光ファイバは、そのコア材がゴム弾
性を有する材質のものから形成される。
An optical fiber having such properties has a core material made of a material having rubber elasticity.

具体的には、例えばエチルアクリレート−2−ヒドロキ
シエチル(メタ)アクリレート共重合体、エチルアクリ
レート−グリシジル(メタ)アクリレート共重合体、ブ
チルアクリレート−(メタ)アクリル=3− 酸共重合体、エチルアクリレート−(メタ)アクリルア
ミド共重合体などを、ヘキサメチレンジイソシアネート
、その3量体、ジエチレントリアミンなどで架橋したも
のから形成される。
Specifically, for example, ethyl acrylate-2-hydroxyethyl (meth)acrylate copolymer, ethyl acrylate-glycidyl (meth)acrylate copolymer, butyl acrylate-(meth)acrylic = 3-acid copolymer, ethyl acrylate - It is formed by crosslinking a (meth)acrylamide copolymer or the like with hexamethylene diisocyanate, its trimer, diethylenetriamine, or the like.

かかるゴム弾性を有するコア材の耐久復元性をみるため
に、JIS K−6301に基き屈曲試験を行なうと、
エチルアクリレート−2−ヒドロキシエチルアクリレー
ト(モル比10: 1)共重合体に10重量2のへキサ
メチレンジイソシアネートを加え、80℃で4時間架橋
して得られた試験片については、毎分300回の屈曲速
度で3000回屈曲させたとき、亀裂成長の長さはわず
か1 、2mmであったので、反覆使用時の復元性につ
いては問題がみられなかった。
In order to examine the durability and recovery properties of the core material having such rubber elasticity, a bending test was conducted based on JIS K-6301.
For the test piece obtained by adding 10 weight 2 hexamethylene diisocyanate to the ethyl acrylate-2-hydroxyethyl acrylate (molar ratio 10:1) copolymer and crosslinking at 80°C for 4 hours, the crosslinking rate was 300 times per minute. When it was bent 3,000 times at a bending speed of 3,000 times, the length of crack growth was only 1.2 mm, so there was no problem with respect to recovery after repeated use.

コア材を被覆するクラツド材としては、コア材材料より
も約1〜2%程度屈折率の低い材料が用いられ1例えば
LH,LH,IH−トリフルオロエチルアクリレート、
LH,IH,5H−オクタフルオロペンチルアクリレー
トなどにエチルアクリレート、ブチルアクリレート、メ
トキシエチルアクリレート、2−ヒドロキシエチルアク
リレートなどを約5〜20モル%=4= 共重合させた共重合体などを、ヘキサメチレンジイソシ
アネート、その3量体などで架橋させたものが用いられ
る。
As the cladding material covering the core material, a material having a refractive index about 1 to 2% lower than that of the core material is used. For example, LH, LH, IH-trifluoroethyl acrylate,
A copolymer obtained by copolymerizing LH, IH, 5H-octafluoropentyl acrylate, etc. with ethyl acrylate, butyl acrylate, methoxyethyl acrylate, 2-hydroxyethyl acrylate, etc. at about 5 to 20 mol% = 4 = hexamethylene, etc. Those crosslinked with diisocyanate, its trimer, etc. are used.

〔作用〕および〔発明の効果〕 本発明で用いられている光ファイバは、ゴム弾性を有し
ているため、石英製あるいはプラスチック製のコア材を
有する光ファイバに比べ、柔がいため微量の荷重でも出
射光の光量が変化し、圧力センサとしての感度を高めて
いる。
[Function] and [Effects of the Invention] The optical fiber used in the present invention has rubber elasticity and is softer than optical fibers with core materials made of quartz or plastic, so it can withstand a small amount of load. However, the amount of emitted light changes, increasing the sensitivity of the pressure sensor.

体積弾性率の点からコア材材料をみると、それぞれ石英
が4〜6 X 1011ダイン/cm2、ポリメチルメ
タクリレートが約IQ111ダイン7cm2、エチルア
クリレート−2−ヒドロキシエチルアクリレート共重合
体が約1(1’〜lO7ダイン/cm”という値を有し
ており、弾性回復限界も大きく、ひずみ率でもポリメチ
ルメタクリレートが2〜3%であるのに対し、エチルア
クリレート−2−ヒドロキシエチルアクリレート共重合
体は100%以上であり、このような光ファイバのゴム
弾性が荷重の微小変化、換言すれば圧力の微小変化に対
し大きな光量変化率として示されるので、精度よく微圧
変化を読みとることができる。
Looking at the core materials in terms of bulk modulus, quartz has a bulk modulus of 4 to 6 It has a value of '~lO7 dynes/cm'', and has a large elastic recovery limit, and the strain rate is 2 to 3% for polymethyl methacrylate, whereas ethyl acrylate-2-hydroxyethyl acrylate copolymer has a large elastic recovery limit. 100% or more, and the rubber elasticity of such an optical fiber is shown as a large rate of change in light amount in response to a minute change in load, in other words, a minute change in pressure, so minute changes in pressure can be read with high accuracy.

〔実施例〕〔Example〕

次に、実施例について本発明を説明する。 Next, the present invention will be explained with reference to examples.

実施例 第1図に示される微圧センサ(波状板の高さ8mm、山
、谷部曲率半径5ml11、長さ二上部50mm、下部
70mm)を用い、全長1m、直径1mm、コア材エチ
ルアクリレート−2−ヒドロキシエチルアクリレート共
重合体のへキサメチレンジイソシアネート架橋体、クラ
ツド材オクタフルオロペンチルアクリレート−2−ヒド
ロキシエチルアクリレート共重合体のへキサメチレンジ
イソシアネート架橋体の光ファイバに、660nmのレ
ーザー光線を入射し、その際上部波状板の荷重を種々変
更して、検出器により出射光の光量変化率を測定した。
Example Using the micro-pressure sensor shown in FIG. 1 (corrugated plate height 8 mm, peak and valley curvature radius 5 ml 11, length 2, upper 50 mm, lower 70 mm), total length 1 m, diameter 1 mm, core material ethyl acrylate. A 660 nm laser beam is incident on an optical fiber made of a hexamethylene diisocyanate cross-linked product of a 2-hydroxyethyl acrylate copolymer and a hexamethylene diisocyanate cross-linked product of a clad material octafluoropentyl acrylate-2-hydroxyethyl acrylate copolymer, At that time, the load on the upper corrugated plate was variously changed, and the rate of change in the amount of emitted light was measured using a detector.

得られた結果は、後記表に示される。The results obtained are shown in the table below.

比較例 実施例において、コア材ポリメチルメタクリレートが用
いられ、同様の測定が行われた。得られた結果は1次の
表に示される。
Comparative Example In the example, the core material polymethyl methacrylate was used and similar measurements were performed. The results obtained are shown in the following table.

表 0       1.00     1.000.2 
     0.89 0.4      0.82 0.6      0.77 0.8      0.72 1.0      0,68     0.992.0
      0.43     0.983.0   
   0.30 4.0      0.22     0.975.0
      0.14 10               0.8315  
             0.8020      
         0.7825          
     0.7630              
 0.74
Table 0 1.00 1.000.2
0.89 0.4 0.82 0.6 0.77 0.8 0.72 1.0 0,68 0.992.0
0.43 0.983.0
0.30 4.0 0.22 0.975.0
0.14 10 0.8315
0.8020
0.7825
0.7630
0.74

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は、本発明に係る微圧センサの一態様の正面図で
ある。第2〜3図は、それぞれ光ファイバの曲率半径ま
たは伸びと光量変化率との関係を示すグラフである。 (符号の説明) 1.2・・・波状板 3・・・・・・光ファイバ
FIG. 1 is a front view of one embodiment of a low pressure sensor according to the present invention. 2 and 3 are graphs showing the relationship between the radius of curvature or elongation of an optical fiber and the rate of change in light amount, respectively. (Explanation of symbols) 1.2...Corrugated plate 3...Optical fiber

Claims (1)

【特許請求の範囲】[Claims] 1、互いに噛み合う形状および位置関係にある隔離され
た2枚の波状板の間にゴム弾性を有する光ファイバをほ
ぼ直線状に挟着し、一方の波状板側からの加圧を光ファ
イバの出射光の光量変化量として測定し得るようにした
微圧センサ。
1. An optical fiber having rubber elasticity is sandwiched almost linearly between two separated corrugated plates that are shaped and positioned to engage with each other, and pressure is applied from one of the corrugated plates to the output light of the optical fiber. A micro-pressure sensor that can measure changes in light intensity.
JP25639487A 1987-10-13 1987-10-13 Fine pressure sensor Pending JPH0198935A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP25639487A JPH0198935A (en) 1987-10-13 1987-10-13 Fine pressure sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP25639487A JPH0198935A (en) 1987-10-13 1987-10-13 Fine pressure sensor

Publications (1)

Publication Number Publication Date
JPH0198935A true JPH0198935A (en) 1989-04-17

Family

ID=17292068

Family Applications (1)

Application Number Title Priority Date Filing Date
JP25639487A Pending JPH0198935A (en) 1987-10-13 1987-10-13 Fine pressure sensor

Country Status (1)

Country Link
JP (1) JPH0198935A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0393753U (en) * 1990-01-12 1991-09-25
JPH0393754U (en) * 1990-01-12 1991-09-25
US5272333A (en) * 1992-10-23 1993-12-21 Gas Research Institute System for characterizing pressure, movement, and temperature of fluids
US5326969A (en) * 1992-10-22 1994-07-05 Gas Research Institute System for characterizing flow pattern and pressure of a fluid

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0393753U (en) * 1990-01-12 1991-09-25
JPH0393754U (en) * 1990-01-12 1991-09-25
US5326969A (en) * 1992-10-22 1994-07-05 Gas Research Institute System for characterizing flow pattern and pressure of a fluid
US5488224A (en) * 1992-10-22 1996-01-30 Gas Research Institute System for characterizing flow pattern, pressure and movement of a fluid
US5272333A (en) * 1992-10-23 1993-12-21 Gas Research Institute System for characterizing pressure, movement, and temperature of fluids

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