JPS6383613A - Electromagnetic flow meter - Google Patents

Electromagnetic flow meter

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Publication number
JPS6383613A
JPS6383613A JP22921086A JP22921086A JPS6383613A JP S6383613 A JPS6383613 A JP S6383613A JP 22921086 A JP22921086 A JP 22921086A JP 22921086 A JP22921086 A JP 22921086A JP S6383613 A JPS6383613 A JP S6383613A
Authority
JP
Japan
Prior art keywords
magnetic flux
coil
coils
tube
flux density
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.)
Granted
Application number
JP22921086A
Other languages
Japanese (ja)
Other versions
JP2751152B2 (en
Inventor
Takahiro Fudeyasu
筆保 隆弘
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.)
Shimadzu Corp
Original Assignee
Shimadzu 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
Family has litigation
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Application filed by Shimadzu Corp filed Critical Shimadzu Corp
Priority to JP61229210A priority Critical patent/JP2751152B2/en
Publication of JPS6383613A publication Critical patent/JPS6383613A/en
Application granted granted Critical
Publication of JP2751152B2 publication Critical patent/JP2751152B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Abstract

PURPOSE:To reduce the power consumption of an electromagnetic flow meter by winding coils for excitation around a core which has large residual magnetic flux density and small coercive force and supplying an exciting current to the coil in a period much smaller than a cycle. CONSTITUTION:This flow meter has a couple of electrodes 2 and 3 provided on the internal wall surface of a tube 1 where fluid to be measured flows. Further, coils 4 and 5 are provided outside the tube 1 and the exciting current is supplied from an exciting circuit 6 to lead a signal corresponding to the flow rate out of the electrodes 2 and 3 through an amplifier 7. The coils 4 and 5 are wound around the core 8 made of a material which has large residual magnetic flux density Ba and small coercive force Hc and the current supplied from the circuit 6 to the coils 4 and 5 is much shorter than a cycle T and momentary. Thus, the coercive force Hc of the core 8 is small, so inversion is easily caused by magnetic fields of the coils 4 and 5 and the high magnetic flux density can be maintained even if the magnetic fields are ceased by ceasing the current of the coils 4 and 5 because the residual magnetic flux density Ba is large. Thus, the exciting current is made momentary and the magnetic flux in the tube 1 becomes sufficient for measurement.

Description

【発明の詳細な説明】 (イ)産業上の利用分野 この発明は、電磁流量計、特に消費電力の軽減された電
磁流量計に関する。
DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to an electromagnetic flowmeter, and particularly to an electromagnetic flowmeter with reduced power consumption.

(ロ)従来の技術 従来の電磁流量計は、第4図に示すように、被測定流体
を流す管41の内壁面に、互いに対面する1対の電極4
2.43を設け、一方、管外に設けるコイル44.45
に励磁回路46より低周波の励磁電流を流し、管41の
軸及び電極42.43方向に直交する磁界を加え、電極
42.43から増幅器47を経て、流量に応じた信号を
導出している。上記励磁用のコイル44.45は、空心
かあるいはコアを有するものでも、その材質は鉄板ある
いはケイ素鋼材で成るものであった。また、励磁回路4
6よりコイル44.45に流す励磁電流は、第5図(a
)のように間欠励磁のものか、第6図(a)のような休
止期間のないものが大半であった。
(B) Prior art As shown in FIG. 4, a conventional electromagnetic flowmeter has a pair of electrodes 4 facing each other on the inner wall surface of a pipe 41 through which a fluid to be measured flows.
2.43 is provided, while a coil 44.45 is provided outside the tube.
A low-frequency excitation current is passed through the excitation circuit 46, a magnetic field perpendicular to the axis of the tube 41 and the direction of the electrodes 42, 43 is applied, and a signal corresponding to the flow rate is derived from the electrodes 42, 43 via the amplifier 47. . The excitation coils 44, 45 are either air-core or have a core, and are made of iron plate or silicon steel. In addition, the excitation circuit 4
6 to the coil 44.45 is as shown in Fig. 5 (a
), most of them were intermittently excited, or had no rest period, as shown in Fig. 6(a).

第5図(bl、第6図(blは、それぞれの励磁電流に
対応して流体が流れる管内に生じる磁束である。
FIG. 5 (bl) and FIG. 6 (bl) are the magnetic fluxes generated in the tube through which the fluid flows in response to the respective excitation currents.

(ハ)発明が解決しようとする問題点 上記従来の電磁流量計では、間欠励磁、非間欠励磁の如
何に拘らず、管に磁束を加える期間は、コイルに励磁電
流を流しているので、多くの電力を消費するため、いわ
ゆる二線式の電磁流量計を実現することは不可能であっ
た。
(c) Problems to be solved by the invention In the conventional electromagnetic flowmeter described above, regardless of whether the excitation is intermittent or non-intermittent, the excitation current is passed through the coil during the period when magnetic flux is applied to the tube. It was impossible to realize a so-called two-wire electromagnetic flowmeter because of the power consumption.

この発明は上記に鑑み、管への磁束入力期間よりも短い
期間の励磁電流とし、より消費電力の軽減された電磁流
量計を提供することを目的としている。
In view of the above, it is an object of the present invention to provide an electromagnetic flowmeter that uses an excitation current for a shorter period than the magnetic flux input period to the tube, and further reduces power consumption.

(ニ)問題点を解決するための手段及び作用この発明の
電磁流量計は、上記問題点を解決するために、励磁用の
コイルを残留磁束密度の大で保磁力の小なる材料で構成
したコアに巻回すると共に、励磁信号の正負の周期に比
して十分に小さな期間だけ前記コイルに励磁電流を流す
ようにしている。
(d) Means and action for solving the problems In order to solve the above problems, the electromagnetic flowmeter of the present invention has an excitation coil made of a material with a large residual magnetic flux density and a small coercive force. The coil is wound around the core, and the excitation current is caused to flow through the coil for a period sufficiently small compared to the positive and negative cycles of the excitation signal.

この電磁流量計では、励磁用のコイルを残留磁束密度が
大で保磁力の小さな材質のコアに巻回しているので、コ
ア内の磁束はコイル自身による磁界によって容易に反転
し、またコイルによる磁界をOにしても、高い磁束密度
を保持できる。従って、コイルにはごくわずかの短期間
に励磁電流を流すのみで、管内に必要な磁束を形成でき
る。
In this electromagnetic flowmeter, the excitation coil is wound around a core made of a material with high residual magnetic flux density and low coercive force, so the magnetic flux in the core is easily reversed by the magnetic field generated by the coil itself, and the magnetic flux generated by the coil Even if it is set to O, a high magnetic flux density can be maintained. Therefore, the necessary magnetic flux can be generated within the tube by only passing an excitation current through the coil for a very short period of time.

(ホ)実施例 以下、実施例により、この発明をさらに詳細に説明する
(E) Examples The present invention will be explained in more detail with reference to Examples below.

第1図は、この発明の一実施例を示す電磁流量計の回路
図である。この電磁流量計は、従来と同様に、被測定流
体を流す管1の内壁面に、互いに対面する1対の電極2
.3を設けている。また、管1外にコイル4.5を設け
、励磁回路6より低周波の励磁電流を流し、管1の軸及
び電極2.3方向に直交する磁界を加えている。電極2
.3から増幅器7を経て、流量に応じた信号を導出して
いる。
FIG. 1 is a circuit diagram of an electromagnetic flowmeter showing an embodiment of the present invention. This electromagnetic flowmeter, like the conventional one, has a pair of electrodes 2 facing each other on the inner wall surface of a pipe 1 through which the fluid to be measured flows.
.. There are 3. Further, a coil 4.5 is provided outside the tube 1, and a low-frequency excitation current is passed from an excitation circuit 6 to apply a magnetic field orthogonal to the axis of the tube 1 and the direction of the electrodes 2.3. Electrode 2
.. 3 through an amplifier 7, a signal corresponding to the flow rate is derived.

この電磁流量計の特徴は、励磁用のコイル4.5が、第
2図にそのBH特性を示すように、残留磁束密度Baが
大で、保磁力Hcの小さな材料で構成されるコア8に巻
回され、かつ励磁回路6からコイル4.5に流す電流が
、第3図(a)に示すように、周期Tに比して非常に小
さな期間の瞬時的であることである。
The feature of this electromagnetic flowmeter is that the excitation coil 4.5 has a core 8 made of a material with a large residual magnetic flux density Ba and a small coercive force Hc, as shown in the BH characteristics in Fig. 2. The current flowing from the excitation circuit 6 to the coil 4.5 is instantaneous and has a very small period compared to the period T, as shown in FIG. 3(a).

コア8の保磁力Hcが小さいため、コイル4.5の磁界
によって容易に反転し、また残留磁束密度Baが大きい
ため、コイル4.5の電流をOにし、その磁界を0して
も、高い磁束密度を保持できる。それゆえ、第3図(a
)のように、コイル4.5に流す励磁電流を瞬時的なも
のとしても、管1内の磁束は、第3図(1))に示すよ
うになり、測定に一十分な磁束となる。
Since the coercive force Hc of the core 8 is small, it is easily reversed by the magnetic field of the coil 4.5, and the residual magnetic flux density Ba is large, so even if the current of the coil 4.5 is set to 0 and the magnetic field is 0, the magnetic field remains high. Can maintain magnetic flux density. Therefore, Figure 3 (a
), even if the excitation current flowing through the coil 4.5 is instantaneous, the magnetic flux inside the tube 1 will be as shown in Figure 3 (1)), which is sufficient for measurement. .

なお、コイル4.5に流す励磁電流は、定電流化する必
要がなく、コア8内の磁束密度が飽和する大きさ以上で
あれば、いくらであってもよい。
Note that the excitation current flowing through the coil 4.5 does not need to be a constant current, and may be any value as long as it is equal to or greater than the magnitude at which the magnetic flux density within the core 8 is saturated.

その分、励磁回路6の構成を簡単にできる。また、管1
には磁気センサ9が取付けられており、コア8を介して
管1内に発生した磁束の密度をこの磁気センサ9で検出
し、後段の演算回路で、磁束の変化の補正に使用する。
Accordingly, the configuration of the excitation circuit 6 can be simplified. Also, tube 1
A magnetic sensor 9 is attached to the tube 1, and the magnetic sensor 9 detects the density of magnetic flux generated in the tube 1 via the core 8, and the density of the magnetic flux generated in the tube 1 is detected by the downstream arithmetic circuit and used to correct changes in the magnetic flux.

また、飽和磁束密度の変化は温度に依存するので、上記
磁気センサの代わりに温度センサをコアに付設し、温度
センサ出力に応じて磁束変化を補正するようにしてもよ
い。
Further, since changes in the saturation magnetic flux density depend on temperature, a temperature sensor may be attached to the core instead of the magnetic sensor described above, and magnetic flux changes may be corrected in accordance with the temperature sensor output.

(へ)発明の効果 この発明によれば、励磁用のコイルを残留磁束密度大、
保磁カルのコアに巻回し、かつ周期に比して十分に小さ
な期間にコイルに励磁電流を流すようにしたものである
から、従来に比し、消費電力を大幅に軽減できる。その
ため、二線式電磁流量計も実現できる。
(f) Effects of the invention According to this invention, the excitation coil has a high residual magnetic flux density.
Since the coil is wound around the core of the coercive coil and the excitation current is passed through the coil during a sufficiently small period compared to the period, power consumption can be significantly reduced compared to the conventional method. Therefore, a two-wire electromagnetic flowmeter can also be realized.

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

第1図は、この発明の一実施例を示す電磁流量計の回路
図、第2図は、同電磁流量計に使用されるコアのBH特
性を示す図、第3図(al (blは、同電磁流量計の
励磁電流及び発生磁界の波形を示す図、第4図は、従来
の電磁流量計を示す回路図、第5図(a) (b)及び
第6図(a) (blは、従来の電磁流量計の動作を説
明するための波形図である。 1:管、    2・3:電極、 4・5:励磁用のコイル、 6;励磁回路、  8:コ7゜ 特許出願人       株式会社島津製作所代理人 
   弁理士  中 村 茂 信第1図 8.コア 第4図
Fig. 1 is a circuit diagram of an electromagnetic flowmeter showing an embodiment of the present invention, Fig. 2 is a diagram showing the BH characteristics of the core used in the electromagnetic flowmeter, and Fig. 3 (al (bl is Figure 4 is a diagram showing the waveforms of the exciting current and generated magnetic field of the electromagnetic flowmeter, and Figure 4 is a circuit diagram showing a conventional electromagnetic flowmeter, Figures 5(a), (b), and 6(a) (bl is , is a waveform diagram for explaining the operation of a conventional electromagnetic flowmeter. 1: Tube, 2 and 3: Electrodes, 4 and 5: Excitation coil, 6: Excitation circuit, 8: Ko7゜Patent applicant Shimadzu Corporation Agent
Patent Attorney Shigeru Nakamura Figure 1 8. Core figure 4

Claims (1)

【特許請求の範囲】[Claims] (1)被測定流体が導かれる管の内壁に1対の電極を設
けると共に、前記被測定流体の流れ方向及び前記1対の
電極方向にそれぞれ直交する方向に磁界を加えるコイル
を前記管外に配置し、正負両極性の信号を前記コイルに
加えて励磁電流を流し、前記両電極より前記被測定流体
の流量に応じた信号を導出する電磁流量計において、 前記励磁用のコイルを残留磁束密度の大で保磁力の小な
る材料で構成したコアに巻回すると共に、前記励磁信号
の正負の周期に比して十分に小さな期間だけ前記コイル
に励磁電流を流すようにしたことを特徴とする電磁流量
計。
(1) A pair of electrodes are provided on the inner wall of the tube through which the fluid to be measured is guided, and a coil is installed outside the tube to apply a magnetic field in directions perpendicular to the flow direction of the fluid to be measured and the direction of the pair of electrodes. In an electromagnetic flowmeter, the excitation coil is connected to a residual magnetic flux density in which a signal of both positive and negative polarities is applied to the coil to cause an excitation current to flow, and a signal corresponding to the flow rate of the fluid to be measured is derived from the two electrodes. The coil is wound around a core made of a material having a large coercive force and a small coercive force, and the excitation current is caused to flow through the coil only for a sufficiently small period compared to the positive and negative cycles of the excitation signal. Electromagnetic flowmeter.
JP61229210A 1986-09-27 1986-09-27 Electromagnetic flow meter Expired - Lifetime JP2751152B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP61229210A JP2751152B2 (en) 1986-09-27 1986-09-27 Electromagnetic flow meter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP61229210A JP2751152B2 (en) 1986-09-27 1986-09-27 Electromagnetic flow meter

Publications (2)

Publication Number Publication Date
JPS6383613A true JPS6383613A (en) 1988-04-14
JP2751152B2 JP2751152B2 (en) 1998-05-18

Family

ID=16888544

Family Applications (1)

Application Number Title Priority Date Filing Date
JP61229210A Expired - Lifetime JP2751152B2 (en) 1986-09-27 1986-09-27 Electromagnetic flow meter

Country Status (1)

Country Link
JP (1) JP2751152B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016020835A (en) * 2014-07-14 2016-02-04 愛知時計電機株式会社 Electromagnetic flowmeter and core

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55106316A (en) * 1979-02-08 1980-08-15 Aichi Tokei Denki Co Ltd Electromagnetic flow meter
JPS59154322A (en) * 1983-02-23 1984-09-03 Aichi Tokei Denki Co Ltd Electromagnetic flowmeter
JPS60242318A (en) * 1984-05-16 1985-12-02 Aichi Tokei Denki Co Ltd Remanent magnetism type electromagnetic flow meter

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55106316A (en) * 1979-02-08 1980-08-15 Aichi Tokei Denki Co Ltd Electromagnetic flow meter
JPS59154322A (en) * 1983-02-23 1984-09-03 Aichi Tokei Denki Co Ltd Electromagnetic flowmeter
JPS60242318A (en) * 1984-05-16 1985-12-02 Aichi Tokei Denki Co Ltd Remanent magnetism type electromagnetic flow meter

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016020835A (en) * 2014-07-14 2016-02-04 愛知時計電機株式会社 Electromagnetic flowmeter and core

Also Published As

Publication number Publication date
JP2751152B2 (en) 1998-05-18

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