JPS59198320A - Electromagnetic flow meter - Google Patents

Abstract

PURPOSE:To facilitate molding process, uniformize flux density, and improve measuring accuracy, by laminating a plurality of insulated sheets provided with print-circuited spiral conductive circuits and arranging magnetic flux deflecting boards made of ferromagnetic foils on their outside. CONSTITUTION:On the outside of exciting coils 10 constructed by lamination of a plurality of flexible insulating sheets 8 of print-circuited spiral conductive circuit 7, are located magnetic flux deflecting boards 12 constructed by lamination of a plurality of amorphous alloy foils 11, as ferromagnetic foils. By this arrangement, appropriate magnetic flux flow between both exciting coils 10, 10 and especially, flow outside of the measuring pipe 1 can be assured resulting to a higher measuring accuracy and easier molding process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electromagnetic flowmeter, and more particularly to an improvement in a magnetic field generating means for applying a magnetic field to a measuring fluid in a measuring tube in a direction perpendicular to that direction.

[Prior art]

In general, an electromagnetic flow needle uses Faraday's electromagnetic induction phenomenon to convert the flow rate of a conductive fluid passing through a measurement tube into an electrical signal and performs the measurement, and has no moving parts.
It also has the advantage of not causing pressure loss during measurement, and can also measure the flow rate of a mixed flow containing corrosive fluids, slurry, solids, etc., which is difficult to do with other measurement methods.

As an electromagnetic flowmeter having these functions, one having a configuration as shown in FIG. 1 has been known.

To explain this simply, the mononoke indicated by the reference numeral 1 in the figure is a measurement tube that has external connection flanges (not shown) at both ends and is installed in the middle of the flow path piping for the measurement fluid. The inner lining 1a is made of an insulating material such as Teflon or neoprene. A pair of excitation coils 2.2 formed by winding coils in a substantially saddle shape are arranged on the upper and lower sides of this measuring tube 1, and are arranged at right angles to the direction of fluid flow. A pair of electrodes 3, 3 configured to apply a magnetic field and to extract an electromotive force generated in the fluid in a direction perpendicular to the direction of the magnetic field and the direction of the flow in proportion to the flow velocity. is the measuring tube 1
They are placed so that they face each other inside. Of course, these pair of electrodes 3, 3 and excitation coils 2, 2 are connected to each other when cores 4, 4 consisting of an external control board, etc. are inserted through lead wires and terminal boards (not shown), respectively. 4, 4 are arranged so as to surround the measuring tube 1 in a substantially rectangular shape and are connected by yoke members 5, 5 forming a magnetic flux path, and each of these constituent members is It is housed in a casing 6 that surrounds the casing 6 and has a substantially housing shape.

By the way, what is desired in an electromagnetic flowmeter having the above-mentioned configuration is that the configuration of each part is simple, the moldability of each part is excellent in terms of ease of assembly, and the overall size is small, lightweight, and compact. Moreover, it is possible to obtain highly reliable measurement accuracy.

From these points of view, since the excitation coils 2, 2 as the magnetic field generating means are formed by a coil winding method, the shaping process is not troublesome, and the shape is likely to be uneven. However, there are drawbacks such as the inability to obtain a uniform surface magnetic flux density, and improvements are needed.

For this reason, it has been considered to use, as such an excitation coil, a structure formed by laminating a large number of flexible insulating sheets 8 on which spiral conductive circuits 7 are printed, as shown in FIG. An excitation coil made using such a flexible insulating sheet 8 with printed wiring is easier to mold and process, and has a greater degree of freedom in terms of shape and size, compared to conventional coil winding methods. Moreover, it is effective in making the magnetic flux density uniform, preventing stray electromotive force, and improving the reliability of measurement accuracy.

However, when the above-described excitation coil formed by laminating the printed wiring flexible insulating sheet 8 is adopted, problems arise with the core 4, yoke 5, etc. as magnetic field generating means. In other words, if these cores and yokes are not used, it will be difficult to obtain an appropriate flow of magnetic flux and it will not be possible to generate a magnetic field efficiently.Furthermore, if the conventional structure is used as is, the overall components will be In many cases, if the structure is complicated, problems may arise in terms of assembly, etc., and the advantages of laminating flexible insulating sheets with printed wiring cannot be utilized, so some countermeasures must be taken. It is hoped that this will be done.

[Summary of the invention]

The present invention has been made in view of these circumstances.
A simple configuration in which a magnetic flux deflection plate made of ferromagnetic foil made of an amorphous alloy or the like is placed on the outside of an excitation coil made of multiple printed wiring insulating sheets can be used to It is possible to obtain an appropriate flow of magnetic flux between a pair of excitation coils and improve measurement accuracy, and it is also excellent in terms of moldability and assembly, and the overall size is small, lightweight, and compact. This provides an inexpensive electromagnetic flow rate that can also achieve the following.

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

Figure 3 shows an embodiment of the electromagnetic flowmeter according to the present invention. In these figures, the same or corresponding parts as in Figures 1 and 2 are given the same numbers and their explanations are given. is omitted.

According to the present invention, a plurality of ferromagnetic foils, for example, amorphous alloy foils 11, are placed on the outside of each excitation coil 10 made of a flexible insulating sheet 8 formed by printed wiring of a plurality of helical conductive circuits 7. A magnetic flux deflection plate 12 formed by stacking is provided, and thereby the magnetic flux flow between the two excitation coils 10 and 10, especially the flow outside the measuring tube 1, can be properly and reliably obtained. The feature is that the measurement accuracy can be improved.

The magnetic flux deflection plate 12 made of the amorphous alloy foil 11 described above may be continuously laminated on the outside of the excitation coil 10, or may be placed at a sufficient distance from the excitation coil 10 as shown in the figure. The arrangement position, mounting structure, size, and number of layers can be modified and changed as appropriate, and various modifications are possible.

When the magnetic flux deflection plate 12 made of such amorphous alloy foil 11 is disposed outside the excitation coil 1o, as is clear from FIG. As a result, the magnetic flux is deflected by the plate 12 and flows from its end toward the other magnetic flux deflection plate 12. This allows an appropriate flow of magnetic flux, and it is not necessary to use a special core or the like as in the past. There is no need for a yoke, etc., and its moldability makes it easy to form.

It has advantages such as being easy to assemble.

Furthermore, as the amorphous alloy foil 11 constituting the magnetic flux deflection plate 12 described above, for example, cobalt, boron, silicon, and iron-based materials are known, but those made of such materials have a particularly low coercive force. It is small, its magnetic properties change easily, it improves energy efficiency, it is not bulky, it generates less heat, it does not have any negative effects on various parts, and its shape is flexible. Since the degree of freedom in terms of size, etc. is also increased, there is an advantage that the entire device can be made smaller.

When the magnetic flux deflection plate 12 made of such amorphous alloy foil 11 is used, its deflection function can also prevent leakage of magnetic flux toward the device casing, so the magnetic field is strong in the part where the fluid passes. υ, the magnetic field generation part becomes more efficient, and the advantage is significant.

Note that the yoke 5 that connects the excitation coils 10 and 10 to form a magnetic flux path on the outside of the measurement tube 1 is not necessarily necessary, but as shown in FIG. 5 may be attached, and this may be provided only on one side as shown in the figure, or it may not be brought into contact with the magnetic flux deflection plates 12 and 12, but simply placed between the ends thereof. Furthermore, the present invention is not limited to the structure of the embodiment described above, and the shape and structure of each part may be modified as necessary.
You are free to make changes. For example, an alloy material having similar characteristics can be freely used for the amorphous alloy foil 11 in the above-described embodiment. This makes it possible to simplify the process and downsize the entire device.

〔Effect of the invention〕

As explained above, according to the electromagnetic flowmeter according to the present invention, a magnetic flux deflector formed by a ferromagnetic material such as an amorphous alloy material is formed on the outside of the excitation coil, which is made up of a plurality of printed wiring insulating sheets. Since the plates are arranged, the magnetic flux flow between the two excitation coils can be made appropriate despite the simple and easy-to-form structure. is unnecessary, reducing the total number of parts and improving assembly efficiency.
Furthermore, since there is a large degree of freedom in terms of size and shape of the magnetic flux deflection plate as well as the excitation coil, the space needed to accommodate each component within the casing can be kept to the minimum required, making the entire structure smaller, lighter and more compact. It is also possible to measure ff1
It has various excellent effects such as improving the reliability of the system and the durability of each part.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing a conventional example, Fig. 2 is a plan view of a flexible insulating sheet with printed wiring used as an excitation coil, and Fig. 3 is an embodiment of an electromagnetic flowmeter according to the present invention. FIG. 1. Ringing... Measuring tube, 1a-... Lining, 3...
・Electrode, 5--yoke, 6--ke "sink,"
7...Spiral conductive circuit, 8...-Flexible insulation sheet), 10--@excitation coil, 11...Amorphous alloy foil (ferromagnetic material), 12...Magnetic flux change Mukai board. Patent applicant Yamatake Honeywell Co., Ltd. Agent
Masaki Yamakawa (1 person) Fig. 1 Fig. 3 Fig. 2 4-28-1 Nishirokugo, Ota-ku, Tokyo Yamatake Honeywell Co., Ltd. Gao Hall 0 Inventor Hiroshi Watanabe 4-chome Nishirokugo, Ota-ku, Tokyo No. 28-1 Yamatake Honeywell Co., Ltd., Gabao premises 0 Inventor: Masato Kuroda No. 28-1, Nishirokugo, Ota-ku, Tokyo 0 Inventor: Hiroshi Okaniwa, 4-28 Nishirokugo, Ota-ku, Tokyo No. 1 Yamatake Honeywell Co., Ltd. Kamata Factory

Claims (1)

[Claims] A pair of excitation coils that are placed on both sides of the measurement tube and provide a magnetic field in a direction perpendicular to the flow direction of the measurement fluid are constructed by laminating multiple insulating sheets on which spiral conductive circuits are printed. An electromagnetic flowmeter characterized in that a magnetic flux deflection plate made of ferromagnetic foil is disposed on the outside of each of these excitation coils.