JPS58213216A - Electromagnetic flowmeter - Google Patents

Abstract

PURPOSE:To constitute compactly in a small size, by providing a ceramic pipe fixed an exciting coil pattern to its outer circumferential face on the inside of a measuring tube. CONSTITUTION:A magnetic field having magnetic flux which is crossed a fluid flowing in a measuring pipe 2 and is crossed at right angles to a water flowing direction, is formed by exciting an exciting coil pattern 7 through a terminal board 22, a lead wire 23 and a lead pattern 17. Accordingly, electromotive force being proportional to an average flowing speed is generated between both electrodes 12 provided so as to cross at right angles to both directions of the flowing direction and the magnetic flux direction by a Faraday's law and this electromotive force is led to the board 22 through a ring 15, lead patterns 20, 21 and the wire 23. Further, the flow rate is measured or fixed value control of the flow rate is carried out by giving a signal after leading it to an amplifier of the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic flowmeter that electrically measures the flow rate inside a measuring tube.

In general, an electromagnetic flowmeter converts the flow rate of a conductive fluid flowing in a measurement tube into an electrical signal by using Faraday's electromagnetic induction phenomenon, and is generally constructed as follows. In other words, this type of electromagnetic flowmeter is equipped with a measuring tube that is connected with 7 lunges in the middle of the main pipe through which the fluid to be measured flows, and this measuring tube has 2 insulation rings made of synthetic resin such as Teflon. is lined inside. On both sides of the measuring tube, a pair of saddle-shaped excitation coils are held by a core and a case and are placed opposite each other. The structure is such that a magnetic field having a magnetic flux in a direction perpendicular to the flow is formed. Furthermore, on the outer circumference of the measuring tube, a pair of electrodes connected to the terminal board on the housing side with lead wires are perpendicular to both the magnetic flux direction and the fluid flow direction, and are insulated from the measuring tube. has been inserted. With this configuration, when fluid passes through the measurement tube and the excitation coil is excited, a magnetic field is formed that is perpendicular to the flow direction of the fluid, and this magnetic field, flowing water, and electrode arrangement are mutually orthogonal. As a result, an electromotive force proportional to the average flow velocity of the fluid is generated between the two electrodes according to Faraday's law.The current is measured by amplifying this electromotive force with an amplifier.Fixed value control of the flow rate You can do this if you have done so.

Conventional electromagnetic flowmeters that operate in this manner have a large excitation coil installed between the measurement tube and the housing, and lead wires for the electrodes. Because of this, there was a drawback that the overall size was large compared to the diameter of the measuring tube. In addition, since the measuring tube is lined with an insulating lining, this tends to peel off from the measuring tube at high temperatures and become brittle.To avoid this, restrictions were placed on the type of fluid to be measured and the flow rate. .

The present invention was developed in view of the above points, and by arranging a ceramic pipe with an excitation coil pattern on the outer circumferential surface inside the measuring tube, it is resistant to temperature and fluid corrosion, and is small and compact. In addition to providing an electromagnetic flowmeter with a compact configuration, the electromagnetic flow meter has an even smaller and more compact configuration by covering a ceramic pipe with an excitation coil pattern and a plastic sheet with an electromagnetic lead pattern. It provides a flowmeter. Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 4 show an embodiment of an electromagnetic flowmeter according to the present invention, FIG. 1 is a side sectional view thereof, FIG. 2 is a vertical sectional view thereof, and FIG. 3 is a partially exploded perspective view of a ceramic pipe. Figure, 4th
The figure is a developed view of the excitation coil pattern. In the figure,
The electromagnetic flowmeter 1 is equipped with a measurement v2 having seven flanges 21 at both ends that are joined in the middle of a main pipe through which the fluid to be measured flows, and a terminal box 3 and a A pair of electrode boxes 4 facing each other orthogonally are integrally formed.

The reference numeral 5 denotes a ceramic pipe that is rotatably supported inside the measuring tube 2 through an O-ring 6, and is coated with wood on the outer peripheral surface of the ceramic pipe 5, as shown expanded in FIG. A pair of winding patterns 7m and 7b with the same winding direction.
The excitation coil pattern 1 is made using printing technology, and both winding patterns 7a*7
b is arranged directly below the terminal box 3 and facing the opposite side of the terminal box 3, and both winding patterns 7m, 7
Terminals 7a and 7d are provided at terminal b.

The center part of the outer peripheral surface of the ceramic pipe 5 on which the excitation coil pattern T is formed in this way is a strip-shaped plastic sheet 8 made of insulating plastic.
This plastic sheet is covered with 802 parts.
[In, the terminal 7 a + of the excitation coil pattern 7
A through hole 9 is provided to expose T d to the outside. In addition, through-holes 11 are bored at both locations of the plastic sheet 8 corresponding to the electrode box 4, overlapping with the electrode holes 10 provided in the ceramic pipe 5 and communicating the running water between the outside and the inside of the plastic sheet 8. ing. And this through hole 11
A pair of electrodes 12 are inserted into the electrode holes 10 with their tips protruding into the flowing water, and are attached in the direction of protrusion into the fluid by a pressure spring 13 interposed between the electrode box 4 and the lid. Forced. An O-ring 14 is attached to the electrode 12, and a ring 15, which is short-circuited to running water by the 'electrode 12, is provided around the through hole 11 of the plastic sheet 8 using printing technology. The plastic sheet 8 also includes a terminal 7d that is not visible on the opposite side of the terminal IC in FIG. 3, and a terminal 16 that is in fin contact with the terminal 1c.
A lead pattern IT is created using printing technology, and a plastic sheet 8
A lead pattern 20.2 connects each ring 15 and the terminal 18.19 adjacent to the terminals 7e and 16.
1 is created using printing technology. Then, the four terminals 7c, 16, 18t19 and the terminal box 3
The connection between the inner terminal board 22 and the terminal board 22 is so that it can be taken out to the outside. 23.

In the electromagnetic flowmeter configured as described above, the terminal board 2
When the exciting coil pattern 7 is excited through the lead wire 23, the lead wire 23, and the lead pattern 17, a magnetic field having a magnetic flux that traverses the fluid flowing in the measuring tube 2 and is perpendicular to the direction of the water flow is formed. Therefore, an electromotive force proportional to the average flow velocity is generated between the electrodes 12 arranged perpendicularly to both the flowing water direction and the magnetic flux direction according to Fanchy's law, and this electromotive force is generated between the electrodes 12 and the lead. Pattern 20.2
1 and lead wires 23 to the terminal board 22. After this is led to an external amplifier, a signal is emitted, flow forging is measured, and constant value control of doping is performed.

In this embodiment, an example was shown in which the excitation coil pattern I was formed on the ceramic pipe 5 using printing technology, but other methods such as vapor deposition, plating, and etching that printed with conductive paint and fired it were also shown. It may also be fabricated using semiconductor manufacturing techniques employed in the manufacturing process and recent photographic techniques.

Further, in this embodiment, an example was shown in which the ceramic pipe 5 was directly coated with the plastic snack sheet 8, but in order to prevent the excitation coil pattern 1 from oxidizing, it is necessary to cover the ceramic pipe 5 with the excitation coil pattern 7. It is desirable to cover with a plastic sheet or a plastic tube, melt and bond by heating, and then cover the top with a plastic sheet 8. Furthermore, the plastic sheet 8 may be covered with a rust-preventing sheet or a reinforcing cover, if necessary.

As is clear from the above description, according to the present invention, in an electromagnetic flowmeter, a ceramic pipe having an excitation coil pattern formed on the outer surface is arranged inside the measuring tube, thereby preventing the inside of the measuring tube from being at a high temperature. Even if the pressure is low, the product will not peel or become brittle, so its durability is improved, and it is not limited by the I-4 class of the fluid to be measured or the flow rate. In addition, by eliminating the excitation coil with a large winding and providing an excitation coil pattern in its place, the entire flowmeter can be made extremely small and compact. Furthermore, by covering the ceramic pipe with a plastic sheet provided with an electromagnetic lead pattern, there is no need for lead wires, so the entire flowmeter can be made smaller and more compact.

[Brief explanation of the drawing]

1 to 4 show an embodiment of an electromagnetic flowmeter according to the present invention, FIG. 1 is a side sectional view thereof, FIG. 2 is a vertical sectional view thereof, and FIG. 3 is a partially exploded perspective view of a ceramic pipe. Figure, 4th
The figure is a developed view of the excitation coil pattern. 1. Conflict. @ to measure magnetic current, 2.. Measuring tube, 5..
Ceramic pipe, T...excitation coil pattern, 8
...Plastic sheet, 15...Ring, 1
7, 20, 21... Lead pattern. Patent Applicant Yamatake Honeywell Co., Ltd. Agent Masaki Yamakawa (and 1 other person) -1 (Continued from page 1 0 Inventor Masato Kuroda Yamatake Honeywell Co., Ltd. Kamata Factory, 4-28-1 Nishirokugo, Ota-ku, Tokyo 0 Inventor Makoto Akano - Yamatake Honeywell Co., Ltd. Kamata Factory, 4-28-1 Nishirokugo, Ota-ku, Tokyo Inventor Ryoichi Matsumoto Yamatake Honeywell Co., Ltd. Kamata Factory, 4-28-1 Nishirokugo, Ota-ku, Tokyo Inside

Claims (1)

[Claims] (11) An electromagnetic flowmeter characterized in that a ceramic pipe with an excitation coil pattern formed on the outer circumference is disposed inside a measuring tube. (2) An excitation coil pattern is formed on the outer circumference. This is an electromagnetic flowmeter characterized by a ceramic pipe made in Japan, covered with a plastic sheet with an electromagnetic lead pattern, and placed inside the measuring tube.