JP2992162B2 - Coriolis flow meter - Google Patents
Coriolis flow meterInfo
- Publication number
- JP2992162B2 JP2992162B2 JP4080500A JP8050092A JP2992162B2 JP 2992162 B2 JP2992162 B2 JP 2992162B2 JP 4080500 A JP4080500 A JP 4080500A JP 8050092 A JP8050092 A JP 8050092A JP 2992162 B2 JP2992162 B2 JP 2992162B2
- Authority
- JP
- Japan
- Prior art keywords
- straight pipe
- straight
- pipe
- coriolis
- supporting
- 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 - Fee Related
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/8409—Coriolis or gyroscopic mass flowmeters constructional details
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Volume Flow (AREA)
Description
【0001】[0001]
【技術分野】本発明は、コリオリの原理に基づいた質量
流量計に関し、より詳細には、流体を流通してコリオリ
の力を発生させる振動管を直管とし該直管の断面形状を
非円形とした直管方式のコリオリ流量計に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mass flow meter based on the Coriolis principle, and more particularly to a vibrating tube which circulates a fluid and generates a Coriolis force and has a non-circular cross-sectional shape. And a straight tube type Coriolis flowmeter.
【0002】[0002]
【従来技術】被測流体の流通する流管の一端又は両端を
支持し、該支持点回りに流管を該流管の流れ方向と垂直
な方向に振動したとき、該流管(振動管)の加振部と両
端支持部間にコリオリの力に比例する位相差が生じ、該
コリオリの力が質量流量に比例することを利用した質量
流量計(コリオリ流量計)は周知である。これらのコリ
オリ流量計における振動管は要部をなすもので、流量計
の特性を決定づけるものである。振動管としての形状は
湾曲管と直管とに大別される。湾曲管方式のものはU字
形、S字形、Ω形およびJ字形等の形状があり、コリオ
リの力を有効に取り出すための形状を選択できる点で高
感度の質量流量検出ができるが、形状が大きくなるとい
う短所がある。これに対して、直管方式のものは通常、
直管軸は流れ方向に配設されるので、形状は小さくなる
が振動管の剛性が高いため感度が低く、SN比が低下す
るので外乱に対してより配慮しなければならない短所が
ある。2. Description of the Related Art One end or both ends of a flow tube through which a fluid to be measured flows is supported, and when the flow tube is vibrated around the supporting point in a direction perpendicular to the flow direction of the flow tube, the flow tube (oscillating tube) A mass flow meter (Coriolis flow meter) utilizing the fact that a phase difference proportional to the Coriolis force is generated between the vibrating portion and the supporting portions at both ends, and the Coriolis force is proportional to the mass flow rate is well known. The vibrating tube in these Coriolis flowmeters is an essential part and determines the characteristics of the flowmeter. The shape as a vibrating tube is roughly classified into a curved tube and a straight tube. The curved tube type is available in U-shaped, S-shaped, Ω-shaped, and J-shaped shapes.High-sensitivity mass flow detection is possible in that a shape for effectively extracting the Coriolis force can be selected. The disadvantage is that it becomes larger. In contrast, the straight pipe type is usually
Since the straight tube shaft is arranged in the flow direction, the shape is small, but the rigidity of the vibrating tube is high, the sensitivity is low, and the SN ratio is low.
【0003】本発明に関連した公知文献として、特開昭
62−238419号公報における「流れを連続的に測
定するための装置および方法」がある。これは、平行に
配設された直管を振動管としたコリオリ流量計に関する
ものであり、以下に説明する。As a known document related to the present invention, there is “Apparatus and Method for Continuously Measuring Flow” in JP-A-62-238419. This relates to a Coriolis flow meter using a straight pipe arranged in parallel as a vibrating pipe, and will be described below.
【0004】図5は、従来の直管式のコリオリ流量計を
説明するための図で、図中、50,55は支持部材、5
1,56はフランジ、52は流入口、57は流出口、5
3,54,58,59は分岐管、60a,60bは振動
管、61は励振器、62,63は検出器、64は変換器
である。FIG. 5 is a view for explaining a conventional straight tube type Coriolis flowmeter. In FIG.
1, 56 are flanges, 52 is an inlet, 57 is an outlet, 5
3, 54, 58 and 59 are branch pipes, 60a and 60b are vibration pipes, 61 is an exciter, 62 and 63 are detectors, and 64 is a converter.
【0005】図5において、支持部材50と55とは左
右対称形で、各々流入口52、流出口57に連通した分
岐管53と54および58と59とを有し、分岐管53
と58および54と59との間には同寸の円形断面をも
った直管からなる振動管60aと60bとが互いに平行
して連通し固着支持されている。該振動管60aと60
bとの中央部にはコイル61aとコアー61bとからな
る励振器61が設けられ、コイル61aは振動管60a
側に、コアー61bは振動管60b側に、各々コアー6
1bがコイル61aの中央に挿入されるように配設さ
れ、更に、振動管60aと60bにおける励振器61と
支持部材50と55との支持点の間には、磁石63aと
コイル63bとからなる検出器63と、磁石62aとコ
イル62bとからなる検出器62とが配設されている。
これら検出器62と63および励振器61は変換器64
に接続されている。In FIG. 5, support members 50 and 55 are bilaterally symmetric and have branch pipes 53 and 54 and 58 and 59 communicating with an inlet 52 and an outlet 57, respectively.
And 58 and 54 and 59, vibrating tubes 60a and 60b formed of straight pipes having the same circular cross section are communicated in parallel with each other and fixedly supported. The vibrating tubes 60a and 60
b, an exciter 61 composed of a coil 61a and a core 61b is provided at the center thereof.
The core 61b is connected to the vibrating tube 60b,
1b is disposed so as to be inserted into the center of the coil 61a, and further includes a magnet 63a and a coil 63b between the support points of the exciter 61 and the support members 50 and 55 in the vibration tubes 60a and 60b. A detector 63 and a detector 62 including a magnet 62a and a coil 62b are provided.
These detectors 62 and 63 and the exciter 61 are
It is connected to the.
【0006】図5に示したコリオリ流量計は、まず、変
換器64により励振器61のコイル61が駆動され、検
出器62又は63の何れかの検出コイルに出力する検出
電圧を変換器64にポジティブフィードバックする閉路
を形成してコイル61aがコアー61bを吸引反発する
ように一定振幅に制御され、振動管60aと60bとは
反射位相で加振される。加振により流体が流通する振動
管60aと60bとは、支持点に対して互いに反対の回
転方向の駆動を受けるので、検出器63と62とには励
振による振動検出信号と前記回転角速度と質量流量のベ
クトル積に比例したコリオリの力が重畳され、コリオリ
の力は反対位相であるから、検出器62と63との間に
はコリオリの力に比例する位相差信号が検出され、変換
器64により質量流量に変換出力される。In the Coriolis flowmeter shown in FIG. 5, first, a coil 64 of an exciter 61 is driven by a converter 64, and a detection voltage output to a detection coil of either the detector 62 or 63 is supplied to the converter 64. A closed loop for positive feedback is formed so that the coil 61a is controlled to have a constant amplitude so as to attract and repel the core 61b, and the vibrating tubes 60a and 60b are vibrated in a reflection phase. The vibrating tubes 60a and 60b, through which the fluid flows due to the excitation, are driven in rotation directions opposite to each other with respect to the support point, so that the detectors 63 and 62 have the vibration detection signal by the excitation, the rotational angular velocity and the mass. Since the Coriolis force proportional to the vector product of the flow rates is superimposed and the Coriolis forces are in opposite phases, a phase difference signal proportional to the Coriolis force is detected between the detectors 62 and 63 and the converter 64 Is converted into a mass flow rate and output.
【0007】上述の従来のコリオリ流量計は振動管60
aと60bとは円形断面の直管であり、各々は支持部材
50と55とにより平行に支持されている。更に、支持
部材50と55とはフランジ51と56とにより流管に
接続される。このように振動管60aおよび60bは支
持部材50と55とに両持支持されるので振動管60a
および60bの長手方向に垂直な方向に対して剛性は高
くなる。この結果、コリオリの力による振動管60aお
よび60bの曲げ変形量は小さくなる。すなわち、検出
器62と63との間で検出されるコリオリの力による位
相差信号は小さく外乱を受け易く、振動管60a,60
bに及ぼす配管振動や外部振動によりSN比が低下す
る。検出信号を増大させるためには、振動管60a,6
0bの肉厚を薄くして曲げ剛性を下げるか、測定流体の
流速を増大させなければならない。しかし、振動管60
aと60bの曲げ剛性を下げると測定流体の圧力変化に
より変形し共振周波数が変化し質量流量の測定誤差が大
きくなり、また振動管内の流速をあげると圧力損失が増
大する等の問題を生じる。また直管内での測定流体の乱
れによる雑音がSN比の低下の原因ともなる。The above-mentioned conventional Coriolis flowmeter is a vibration tube 60.
a and 60b are straight pipes having a circular cross section, each of which is supported in parallel by supporting members 50 and 55. Further, the support members 50 and 55 are connected to the flow tube by the flanges 51 and 56. Since the vibration tubes 60a and 60b are supported by the supporting members 50 and 55 in this manner, the vibration tubes 60a and 60b are supported.
And 60b have higher rigidity in the direction perpendicular to the longitudinal direction. As a result, the amount of bending deformation of the vibrating tubes 60a and 60b due to the Coriolis force is reduced. That is, the phase difference signal due to the Coriolis force detected between the detectors 62 and 63 is small and easily subject to disturbance, and the vibration tubes 60a and 60
The S / N ratio decreases due to piping vibration or external vibration exerting on b. In order to increase the detection signal, the vibration tubes 60a, 60
It is necessary to reduce the thickness of Ob to reduce the bending rigidity or increase the flow rate of the measurement fluid. However, the vibration tube 60
If the bending stiffnesses a and 60b are reduced, the fluid is deformed due to a change in the pressure of the measurement fluid, and the resonance frequency is changed. As a result, the measurement error of the mass flow rate is increased. In addition, noise due to turbulence of the measurement fluid in the straight pipe causes a reduction in the SN ratio.
【0008】[0008]
【目的】本発明は、上述のごとき実情に鑑みてなされた
もので、直管式のコリオリ流量計が小形であるという長
所を生かして外部振動の影響を受け難く高感度で更に
は、測定流体の流れの乱れによる雑音を少くしたコリオ
リ流量計を提供することを目的としてなされたものであ
る。The present invention has been made in view of the above-mentioned circumstances, and has the advantage that a straight tube type Coriolis flowmeter is small in size. It is an object of the present invention to provide a Coriolis flowmeter which has reduced noise caused by turbulence in the flow of air.
【0009】[0009]
【構成】本発明は、上記目的を達成するために、(1)
測定流体を流通させる直管と、該直管の両端部を支持す
る支持手段と、前記直管の中央部で該直管を長手方向に
対し直角な方向に振動させる駆動手段と、該駆動手段と
前記支持手段との間に設けられ前記直管に作用するコリ
オリの力による位相差を検知する検出器とからなるコリ
オリ流量計において、前記直管の断面形状を振動方向に
短径なだ円としたこと、或いは、(2)測定流体を流通
させる直管と、該直管の両端部を支持する支持手段と、
前記直管の中央部で該直管を長手方向に対し直角な方向
に振動させる駆動手段と、該駆動手段と前記支持手段と
の間に設けられ、前記直管に作用するコリオリの力によ
る位相差を検知する検出器とからなるコリオリ流量計に
おいて、前記直管の断面形状を振動方向に短径な菱形と
したこと、更には、(3)測定流体を流通させる平行に
配設された複数の直管と、該直管の両端に接合され各々
の直管に測定流体を等流に分配する分岐管と、該分岐管
を支持する支持手段と、前記直管の中央部で該直管を長
手方向に対し直角な方向に互いに反対位相で振動させる
駆動手段と、該駆動手段と前記支持手段との間に設けら
れ、前記直管に作用するコリオリの力による位相差を検
知する検出器とからなるコリオリ流量計において、前記
直管の断面形状を振動方向に短径なだ円としたこと、更
には、(4)測定流体を流通させる平行に配設された複
数の直管と、該直管の両端に接合され各々の直管に測定
流体を等流に分配する分岐管と、該分岐管を支持する支
持手段と、前記直管の中央部で該直管を長手方向に対し
直角の方向に互いに反対位相で振動させる駆動手段と、
該駆動手段と前記支持手段との間に設けられ、前記直管
に作用するコリオリの力による位相差を検知する検出器
とからなるコリオリ流量計において、前記直管の断面形
状を振動方向に短径な菱形としたこと、更には、(5)
前記(1)〜(4)において、前記直管の断面の内部長
径方向に両直管壁から軸心に向けて伸びる所定長さのガ
イドフィンを設けたこと、更には、(6)前記(1)〜
(5)において、前記直管を中央部の所定区間で削除
し、該削除部分を可撓チューブで接続したことを特徴と
するものである。以下、本発明の実施例に基づいて説明
する。To achieve the above object, the present invention provides (1)
A straight pipe through which the measurement fluid flows, supporting means for supporting both ends of the straight pipe, driving means for vibrating the straight pipe at a central portion of the straight pipe in a direction perpendicular to the longitudinal direction, and the driving means And a detector provided between the support means and the detector for detecting a phase difference due to Coriolis force acting on the straight pipe, wherein a cross-sectional shape of the straight pipe is changed in a vibration direction .
A short diameter ellipse or (2) flow of the measurement fluid
A straight pipe which causes, support means for supporting both ends of the straight tube,
A direction perpendicular to the longitudinal direction at the center of the straight pipe
In a Coriolis flowmeter, comprising: a driving means for vibrating the straight pipe, and a detector provided between the driving means and the supporting means and detecting a phase difference caused by Coriolis force acting on the straight pipe; The cross-sectional shape is a diamond with a short diameter in the vibration direction.
And (3) parallel flow of the measurement fluid
A plurality of straight pipes arranged, and joined to both ends of the straight pipes,
A branch pipe for uniformly distributing the measurement fluid to the straight pipe of
Support means for supporting the straight pipe, and extending the straight pipe at the center of the straight pipe.
Vibrates in opposite directions to each other in a direction perpendicular to the hand direction
A driving unit, and a driving unit provided between the driving unit and the supporting unit.
Phase difference due to Coriolis force acting on the straight pipe
A Coriolis flowmeter comprising a detector to know
The cross-sectional shape of the straight pipe is an ellipse with a short diameter in the direction of vibration , and (4) a plurality of parallel pipes through which the measurement fluid flows.
Number of straight pipes, and measured at each straight pipe joined at both ends of the straight pipe
A branch pipe for distributing a fluid in a uniform flow, and a support for supporting the branch pipe;
Holding means, and the straight pipe at a central portion of the straight pipe with respect to the longitudinal direction.
Driving means for vibrating in opposite directions in a direction perpendicular to each other;
The straight pipe provided between the driving means and the supporting means;
Detector that detects the phase difference due to Coriolis force acting on the surface
In a Coriolis flowmeter consisting of:
The shape is a rhombus with a short diameter in the vibration direction, and (5)
In the above (1) to (4) , the internal length of the cross section of the straight pipe
A predetermined length of gas extending radially from both straight pipe walls to the axis
Providing the id fins, and (6) the above (1) to
In (5) , the straight pipe is deleted at a predetermined section in the center.
The removed portion is connected by a flexible tube . Hereinafter, a description will be given based on examples of the present invention.
【0010】図1(a)(b)は、本発明におけるコリ
オリ流量計を説明するための図で、図1(a)は側断面
図、図1(b)は図1(a)の矢視Y−Y断面図であ
り、図中、1,2は支持フランジ、3は外筒、4は直
管、5は駆動装置、6,7は検出器である。FIGS. 1A and 1B are views for explaining a Coriolis flowmeter according to the present invention. FIG. 1A is a side sectional view, and FIG. 1B is an arrow of FIG. 1A. FIG. 2 is a sectional view taken along the line Y-Y, in which 1, 2 are support flanges, 3 is an outer cylinder, 4 is a straight pipe, 5 is a driving device, and 6, 7 are detectors.
【0011】図1(a)において、直管4は図1(b)
に示すように、断面形状はX−X軸とY−Y軸とに軸対
称で、X−X軸方向の管壁面間間隔がY−Y軸方向の管
壁面間間隔よりも長くなっており、図1(b)ではだ円
チューブを示している。該直管4は両端部4a,4bで
支持フランジ1,2の中心部に挿通固着されており、該
直管4の外周部に支持フランジ1,2に両端を固定され
た外筒3が設けられて、支持フランジ1,2と外筒3お
よび直管4とが一体に形成されている。更に、直管4と
外筒3の中央部Mに駆動装置5が装着されている。駆動
装置5はコイル5aとコアー5cとを同軸に配設したも
ので、この軸は直管4の短径軸Y−Y方向である。コイ
ル5aは支持台5bにより外筒3内壁に、コアー5cは
軸固定金具5dにより直管4に固着される。また、支持
フランジ1,2と駆動装置5との間の中央部Mに対して
対称な位置に前記Y−Y軸方向にコイル軸をもつ検出器
6,7が設けられている。検出器6,7は同一のもので
コイル6a,7aと、磁石6c,7cとからなりコイル
を支持台6b,7bを介して外筒3内壁に、磁石6c,
7cは軸固定金具6d,7dにより直管4の管壁に設け
られている。In FIG. 1A, a straight pipe 4 is shown in FIG.
As shown in the figure, the cross-sectional shape is axially symmetric with respect to the XX axis and the YY axis, and the interval between the tube walls in the XX axis direction is longer than the interval between the tube walls in the YY axis direction. 1 (b) shows an elliptical tube. The straight pipe 4 is inserted and fixed to the center of the support flanges 1 and 2 at both ends 4a and 4b, and an outer cylinder 3 having both ends fixed to the support flanges 1 and 2 is provided on the outer circumference of the straight pipe 4. The support flanges 1, 2 and the outer cylinder 3 and the straight pipe 4 are integrally formed. Further, a driving device 5 is mounted on the central portion M of the straight pipe 4 and the outer cylinder 3. The driving device 5 has a coil 5a and a core 5c arranged coaxially, and this axis is in the minor axis YY direction of the straight pipe 4. The coil 5a is fixed to the inner wall of the outer cylinder 3 by the support base 5b, and the core 5c is fixed to the straight pipe 4 by the shaft fixing bracket 5d. Further, detectors 6 and 7 having a coil axis in the YY axis direction are provided at positions symmetrical with respect to a central portion M between the support flanges 1 and 2 and the driving device 5. The detectors 6 and 7 are the same and include coils 6a and 7a and magnets 6c and 7c. The coils are mounted on the inner wall of the outer cylinder 3 via the support bases 6b and 7b.
Reference numeral 7c is provided on the pipe wall of the straight pipe 4 by shaft fixing brackets 6d and 7d.
【0012】次に、以上の如く構成された本発明のコリ
オリ流量計の動作を説明する。直管4は駆動装置5のコ
イル5aに印加される交流駆動電流により駆動されコア
ー5cを吸引反発する。Y−Y軸方向は、直管4の断面
において短径方向であるから直管4の曲げ剛性の最も小
さく、所定振幅で駆動した場合同一断面積の円形断面の
直管を駆動した場合に比べて小さいエネルギでよい。こ
れに対し、駆動方向に直角な方向では、逆に円形断面の
直管に比べて剛性は高い。これは、X−X軸方向での共
振周波数が高くなることを意味し、低い周波数の配管振
動との周波数比が大きくなり外部振動影響が小さくな
る。Next, the operation of the Coriolis flowmeter of the present invention configured as described above will be described. The straight pipe 4 is driven by an AC driving current applied to the coil 5a of the driving device 5, and attracts and repels the core 5c. Since the Y-Y axis direction is the minor diameter direction in the cross section of the straight pipe 4, the bending rigidity of the straight pipe 4 is the smallest, and when driven at a predetermined amplitude, compared with the case where a straight pipe having a circular cross section of the same cross-sectional area is driven. Energy is small. On the other hand, in a direction perpendicular to the driving direction, conversely, the rigidity is higher than that of a straight pipe having a circular cross section. This means that the resonance frequency in the X-X axis direction increases, and the frequency ratio with respect to the low-frequency pipe vibration increases, thereby reducing the influence of external vibration.
【0013】測定流体の流れQが矢印方向である場合、
駆動装置5の駆動により直管4にはコリオリの力が作用
する。コリオリの力は、測定流体の質量流量と直管4の
支持部4a,4bにおける回転角速度のベクトル積に比
例しているから検出器6と検出器7とのコリオリの力は
直管4の軸に対し互いに反対方向の力となり相互間にコ
リオリの力に比例した位相差が生ずる。この位相差は測
定流体の質量流量に比例した値である。When the flow Q of the measurement fluid is in the direction of the arrow,
The Coriolis force acts on the straight pipe 4 by the driving of the driving device 5. The Coriolis force is proportional to the vector product of the mass flow rate of the measurement fluid and the rotational angular velocities at the support portions 4a and 4b of the straight pipe 4. Therefore, the Coriolis force between the detector 6 and the detector 7 is the axis of the straight pipe 4. And a phase difference proportional to the Coriolis force is generated between them. This phase difference is a value proportional to the mass flow rate of the measurement fluid.
【0014】図2は、本発明におけるコリオリ流量計の
他の実施例を説明するための図で、図1(a)は縦断面
図、図1(b)は図1(a)の矢視Y−Y図であり、図
中、11,12は支持フランジ、13は外筒、14,1
5は分岐管、16,17は直管、18は駆動装置、1
9,20は検出器である。FIG. 2 is a view for explaining another embodiment of the Coriolis flowmeter according to the present invention. FIG. 1 (a) is a longitudinal sectional view, and FIG. FIG. 11 is a YY diagram, in which 11, 12 are support flanges, 13 is an outer cylinder, 14, 1
5 is a branch pipe, 16 and 17 are straight pipes, 18 is a drive unit, 1
Reference numerals 9 and 20 denote detectors.
【0015】図2(a)におけるコリオリ流量計は、支
持フランジ11,12と外筒13とで囲まれた空間内
に、直管16,17の両端部を分岐管14および15の
分岐口14bと15b間および分岐口14cと15cと
の間に平行して固着したもので、分岐管14,15は、
流入口14aより流入した測定流体を各々分岐口14
b,14cに等流量に分流し、分岐口15b,15cか
らの流体を流出口15aで等流量合流して流出する。直
管16,17は図2(b)に示すように、軸Y−Y上に
短径を有し、軸X−X軸上に直径を有する例えばだ円の
断面形状を有する。この姿勢では、直管16,17の長
径(X−X軸方向)は平行となっている。また、駆動装
置18と検出器19,20は、図1の場合と等しい配置
であるが、コイルとコア又は磁石は直管16と17と
に、軸がY−Y軸と一致する方向に設けられる。In the Coriolis flowmeter shown in FIG. 2A, both ends of straight pipes 16 and 17 are connected to branch ports 14b of branch pipes 14 and 15 in a space surrounded by support flanges 11 and 12 and outer cylinder 13. And 15b and between the branch ports 14c and 15c are fixed in parallel.
The measuring fluid flowing from the inflow port 14a is
b and 14c, the fluid flows from the branch ports 15b and 15c at the same flow rate at the outlet 15a. As shown in FIG. 2B, the straight pipes 16 and 17 have, for example, an elliptical cross-sectional shape having a minor axis on the axis YY and a diameter on the axis XX. In this posture, the major diameters (XX axis direction) of the straight pipes 16 and 17 are parallel. The driving device 18 and the detectors 19 and 20 have the same arrangement as in FIG. 1, but the coils and the cores or the magnets are provided on the straight pipes 16 and 17 so that the axes coincide with the YY axis. Can be
【0016】図2(a)のコリオリ流量計は、直管1
6,17の短径方向に振動するので、直管16,17の
剛性の小さい方向に加振することとなり、X−X軸方向
では剛性が高く、共振周波数も高いので外部振部の影響
を受け難く、しかもコリオリの力による検出器19,2
0間における位相差信号は倍加するので、図1(a)の
場合に比べて更に高感度になる。The Coriolis flow meter shown in FIG.
Vibration occurs in the short diameter direction of the pipes 6 and 17, so that the straight pipes 16 and 17 are vibrated in a direction in which the rigidity is small. In the XX axis direction, the rigidity is high and the resonance frequency is high. Detectors 19 and 2 that are hard to receive and that use Coriolis force
Since the phase difference signal between 0 is doubled, the sensitivity is further increased as compared with the case of FIG.
【0017】図3(a)(b)は、本発明におけるコリ
オリ流量計の、更に、他の実施例を説明するための図
で、図3(a)は縦断面図、図3(b)は図3(a)の
矢視Y−Y線であり、図中、21,22は可撓管であ
り、図2と同じ作用する部分には図2と同一の参照番号
を付している。FIGS. 3A and 3B are views for explaining still another embodiment of the Coriolis flowmeter according to the present invention. FIG. 3A is a longitudinal sectional view, and FIG. Is a YY line taken in the direction of the arrow in FIG. 3 (a). In the drawing, reference numerals 21 and 22 denote flexible tubes, and the same reference numerals as in FIG. .
【0018】図3(a)は、図2(a)のコリオリ流量
計の直管16,17の中央部分を均等に削除して、削除
部分に可撓管21,22を接続したもので、コイル支持
台18bは直管17の削除された端部17aおよび17
b近傍に跨って固着され、軸固定金具18dは直管16
の端部16a,16b近傍に跨って固着される。可撓管
21および22の曲げ剛性が無視されると、直管16は
各々、分岐管15及び分岐管14、分岐口15b,14
bを各々支点として片持梁となり、直管17は分岐管1
4,15の分岐口14b,15bを各々支点とした片持
梁となる。従って図2(a)の直管16,17が両持梁
であったのに比べて更に剛性は小さくなり小さいエネル
ギで駆動できる。しかも駆動方向(Y−Y軸)に短径で
あるからX−X軸方向の剛性は高くなり外部振動影響の
少ないコリオリ流量計ができる。FIG. 3 (a) shows the Coriolis flowmeter of FIG. 2 (a) in which the central portions of the straight tubes 16 and 17 are equally removed, and the removed portions are connected to flexible tubes 21 and 22. The coil support 18b is connected to the cut ends 17a and 17
b, and is fixed to the vicinity of the straight pipe 16d.
Is fixed over the vicinity of the end portions 16a and 16b of the end portion. If the bending stiffness of the flexible pipes 21 and 22 is neglected, the straight pipe 16 becomes the branch pipe 15 and the branch pipe 14, and the branch ports 15b and 14 respectively.
b becomes a cantilever with each supporting point, and the straight pipe 17 is a branch pipe 1
It becomes a cantilever with the branch ports 14b and 15b of 4 and 15 as fulcrums. Therefore, the rigidity is further reduced as compared with the case where the straight pipes 16 and 17 in FIG. In addition, since the diameter is short in the driving direction (Y-Y axis), the rigidity in the XX axis direction is increased, and a Coriolis flowmeter with less influence of external vibration can be obtained.
【0019】上述において振動される直管の断面形状を
肉厚一定なだ円として説明したが、だ円に限るものでは
なく、直管の振動方向の剛性に対し振動を直角方向の剛
性を高くなる断面形状のものであればよい。図4(a)
〜(d)は、本発明におけるコリオリ流量計の直管の断
面形状を示す図である。In the above description, the cross-sectional shape of the vibrating straight pipe is described as an ellipse having a constant thickness. However, the shape is not limited to an ellipse. Any cross-sectional shape may be used. FIG. 4 (a)
(D) is a figure which shows the cross-sectional shape of the straight pipe | tube of the Coriolis flowmeter in this invention.
【0020】図4(a)は、外形が円30で、内径がだ
円であり、軸Y−Y方向の曲げ剛性に対し軸X−X方向
の曲げ剛性を高くした断面形状を有している。図4
(b)は断面形状が矩形32であり、Y−Y軸方向が短
辺でX−X軸方向を長辺に選んでいる。図4(c)は断
面形状が菱形33であり、Y−Y軸方向が短辺でX−X
軸方向が長辺に選んでいる。図4(d)は、だ円管34
の内部の長軸方向に、管壁34a,34bから軸心Oに
向けてガイドフィン35,36を等しい長さで突出した
もので、Y−Y軸方向の曲げ剛性に対してX−X軸方向
の曲げ剛性が一層増すだけでなく、ガイドフィン35,
36により整流効果が増す。この結果検出信号に流れの
乱れに基く雑音成分が減少しSN比のよい検出信号が得
られる。なおガイドフィン35,36は図4(a)〜図
4(c)の各断面形状のX−X軸方向に設けてもよい。FIG. 4A shows an outer shape of a circle 30, an inner diameter of an ellipse, and a cross-sectional shape in which the bending rigidity in the axis XX is higher than the bending rigidity in the axis YY. I have. FIG.
In (b), the cross-sectional shape is a rectangle 32, and the short side is in the YY axis direction and the long side is in the XX axis direction. In FIG. 4C, the cross-sectional shape is a rhombus 33, and the Y-Y axis direction is XX with the short side.
The axial direction is selected as the long side. FIG. 4D shows an elliptical tube 34.
The guide fins 35, 36 project from the tube walls 34a, 34b toward the axis O at equal lengths in the longitudinal direction of the inside of the tube. Not only is the bending rigidity in the direction further increased, but also the guide fins 35,
36 increases the rectification effect. As a result, a noise component based on the disturbance of the flow is reduced in the detection signal, and a detection signal with a good SN ratio is obtained. The guide fins 35 and 36 may be provided in the XX axis direction of each cross-sectional shape of FIGS.
【0021】[0021]
【効果】以上の説明から明らかなように、本発明による
と、振動管となる直管の断面形状を振動方向に曲げ剛性
を小さく、振動と直角方向の曲げ剛性を高くしたので以
下のような効果が得られる。 1.一定のコリオリの力に基く検出器間の位相差信号を
得るための駆動エネルギを小さくすることができる。 2.配管振動を主とした外部振動は鉛直方向の振動が多
いが、直管の高い曲げ剛性の方向を鉛直方向にすると共
振周波数も高くなり外部振動影響を小さくしSN比の優
れたコリオリ信号が得られる。 3.直管は偏平であるから、測定流体の整流効果があ
る。更に、ガイドフィンを直管内部に設けることにより
整流効果が向上しSN比の優れたコリオリ信号が得られ
る。As is apparent from the above description, according to the present invention, the cross-sectional shape of the straight pipe serving as the vibrating pipe has a small bending rigidity in the vibration direction and a high bending rigidity in the direction perpendicular to the vibration. The effect is obtained. 1. Driving energy for obtaining a phase difference signal between detectors based on a constant Coriolis force can be reduced. 2. External vibrations, mainly pipe vibrations, often have vertical vibrations.However, when the direction of high bending stiffness of a straight pipe is set to the vertical direction, the resonance frequency also increases, reducing the influence of external vibrations and obtaining a Coriolis signal with an excellent SN ratio. Can be 3. Since the straight pipe is flat, there is an effect of rectifying the measurement fluid. Further, by providing the guide fin inside the straight pipe, the rectification effect is improved, and a Coriolis signal having an excellent SN ratio can be obtained.
【図1】 本発明におけるコリオリ流量計を説明するた
めの図である。FIG. 1 is a diagram for explaining a Coriolis flow meter according to the present invention.
【図2】 本発明におけるコリオリ流量計の他の実施例
を説明するための図である。FIG. 2 is a diagram for explaining another embodiment of the Coriolis flow meter according to the present invention.
【図3】 本発明におけるコリオリ流量計の、更に、他
の実施例を説明するための図である。FIG. 3 is a view for explaining still another embodiment of the Coriolis flow meter according to the present invention.
【図4】 本発明におけるコリオリ流量計の直管の断面
形状を示す図である。FIG. 4 is a view showing a cross-sectional shape of a straight pipe of the Coriolis flowmeter according to the present invention.
【図5】 従来の直管式のコリオリ流量計を説明するた
めの図である。FIG. 5 is a view for explaining a conventional straight tube type Coriolis flow meter.
1,2…支持フランジ、3…外筒、4…直管、5…駆動
装置、6,7…検出器。1, 2, support flange, 3 outer cylinder, 4 straight pipe, 5 drive, 6, 7 detector.
Claims (6)
両端部を支持する支持手段と、前記直管の中央部で該直
管を長手方向に対し直角な方向に振動させる駆動手段
と、該駆動手段と前記支持手段との間に設けられ前記直
管に作用するコリオリの力による位相差を検知する検出
器とからなるコリオリ流量計において、前記直管の断面
形状を振動方向に短径なだ円としたことを特徴とするコ
リオリ流量計。1. A straight pipe through which a measurement fluid flows, supporting means for supporting both ends of the straight pipe, and driving means for vibrating the straight pipe at a central portion of the straight pipe in a direction perpendicular to the longitudinal direction. And a detector provided between the driving means and the support means and configured to detect a phase difference due to Coriolis force acting on the straight pipe, wherein a cross-sectional shape of the straight pipe is changed in a vibration direction . A Coriolis flowmeter characterized by a short diameter ellipse .
両端部を支持する支持手段と、前記直管の中央部で該直
管を長手方向に対し直角な方向に振動させる駆動手段
と、該駆動手段と前記支持手段との間に設けられ、前記
直管に作用するコリオリの力による位相差を検知する検
出器とからなるコリオリ流量計において、前記直管の断
面形状を振動方向に短径な菱形としたことを特徴とする
コリオリ流量計。2. A straight pipe through which a measurement fluid flows, and a straight pipe of the straight pipe.
A supporting means for supporting both ends, a driving means for vibrating the straight pipe in a direction perpendicular to a longitudinal direction at a central portion of the straight pipe, and a driving means provided between the driving means and the supporting means; A Coriolis flowmeter comprising a detector for detecting a phase difference caused by a Coriolis force acting on a pipe, wherein a cross-sectional shape of the straight pipe is a rhombus having a short diameter in a vibration direction.
複数の直管と、該直管の両端に接合され各々の直管に測
定流体を等流に分配する分岐管と、該分岐管を支持する
支持手段と、前記直管の中央部で該直管を長手方向に対
し直角の方向に互いに反対位相で振動させる駆動手段
と、該駆動手段と前記支持手段との間に設けられ、前記
直管に作用するコリオリの力による位相差を検知する検
出器とからなるコリオリ流量計において、前記直管の断
面形状を振動方向に短径なだ円としたことを特徴とする
コリオリ流量計。3. A parallel arrangement for flowing a measurement fluid.
A plurality of straight pipes, and each straight pipe is joined to both ends of the straight pipe and measured.
A branch pipe for distributing a constant fluid in a uniform flow, and supporting the branch pipe
A supporting means, and a pair of the straight pipes in a longitudinal direction at a central portion of the straight pipe.
Drive means for vibrating in opposite directions in the direction perpendicular to each other
Provided between the driving means and the support means,
Detects phase differences due to Coriolis forces acting on straight pipes
In the Coriolis flowmeter consisting of
A Coriolis flowmeter characterized in that the surface shape is a short ellipse in the vibration direction .
複数の直管と、該直管の両端に接合され各々の直管に測
定流体を等流に分配する分岐管と、該分岐管を支持する
支持手段と、前記直管の中央部で該直管を長手方向に対
し直角の方向に互いに反対位相で振動させる駆動手段
と、該駆動手段と前記支持手段との間に設けられ、前記
直管に作用するコリオリの力による位相差を検知する検
出器とからなるコリオリ流量計において、前記直管の断
面形状を振動方向に短径な菱形としたことを特徴とする
コリオリ流量計。4. A parallel arrangement for flowing a measurement fluid.
A plurality of straight pipes, and each straight pipe is joined to both ends of the straight pipe and measured.
A branch pipe for distributing a constant fluid in a uniform flow, and supporting the branch pipe
A supporting means, and a pair of the straight pipes in a longitudinal direction at a central portion of the straight pipe.
Drive means for vibrating in opposite directions in the direction perpendicular to each other
Provided between the driving means and the support means,
Detects phase differences due to Coriolis forces acting on straight pipes
In the Coriolis flowmeter consisting of
A Coriolis flowmeter characterized in that the surface shape is a rhombus with a short diameter in the vibration direction .
壁から軸心に向けて伸びる所定長さのガイドフィンを設
けたことを特徴とする請求項1乃至4の何れか一項に記
載のコリオリ流量計。 5. A straight pipe in a direction of an inner major axis of a cross section of said straight pipe.
Provide guide fins of a predetermined length that extend from the wall toward the axis.
Coriolis flowmeter to any one of claims 1 to 4 serial <br/> mounting, characterized in that digit.
該削除部分を可撓チューブで接続したことを特徴とする
請求項1乃至5のいずれか一項に記載のコリオリ流量
計。 6. The straight pipe is deleted at a predetermined section in a central portion,
The Coriolis flowmeter according to any one of claims 1 to 5 , wherein the deleted portion is connected by a flexible tube .
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4080500A JP2992162B2 (en) | 1992-03-02 | 1992-03-02 | Coriolis flow meter |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4080500A JP2992162B2 (en) | 1992-03-02 | 1992-03-02 | Coriolis flow meter |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH05248910A JPH05248910A (en) | 1993-09-28 |
JP2992162B2 true JP2992162B2 (en) | 1999-12-20 |
Family
ID=13720035
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4080500A Expired - Fee Related JP2992162B2 (en) | 1992-03-02 | 1992-03-02 | Coriolis flow meter |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2992162B2 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0587528U (en) * | 1992-04-23 | 1993-11-26 | 横河電機株式会社 | Coriolis mass flow meter |
JP5672855B2 (en) * | 2010-08-25 | 2015-02-18 | ダイキン工業株式会社 | Compressor |
EP4055354A1 (en) * | 2019-11-06 | 2022-09-14 | Micro Motion, Inc. | Coriolis flow meter with flow tube including inserts |
-
1992
- 1992-03-02 JP JP4080500A patent/JP2992162B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JPH05248910A (en) | 1993-09-28 |
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