JPH07128105A - Coil structure for electromagnetic flowmeter and manufacture thereof - Google Patents

Abstract

PURPOSE:To eliminate an operation for covering with a sheet by a hand after a coil is wound and a winding operation of a glass tape, to improve productivity with excellent operability and to perform labor-saving. CONSTITUTION:A coil unit 21 is formed of a coil bobbin 20 and an exciting coil 3 formed by winding a copper wire on an outer periphery of a cylindrical part of the bobbin 20. The bobbin 20 is formed of a pair of upper and lower insulating sheets 22 made in the same shape, and an insulating tube 23 formed in a cylindrical shape. The sheet 22 is formed of a ringlike flat plate 22A haying a hole at a center and slightly larger than a contour shape of the coil 3 and a cylindrical part 22B protruding at a center of one surface of the plate 22A. The tube 23 is engaged with the part 22B of the sheet 22 at outer peripheries of both the ends.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil structure of an electromagnetic flow meter for electrically measuring the flow rate of a measuring fluid flowing in a measuring pipe and a method for manufacturing the coil structure.

[0002]

2. Description of the Related Art An electromagnetic flowmeter of this kind for electrically measuring the flow rate of a conductive fluid by utilizing an electromagnetic induction phenomenon is generally constructed as shown in FIGS. That is, reference numeral 1 denotes a cylindrical measuring tube having connection pipe flanges 1a and 1b integrally provided at both ends and an insulating lining 2 made of, for example, a fluororesin or the like on the entire inner peripheral surface thereof. A pair of exciting coils 3A and 3B for generating a magnetic field in the direction orthogonal to the flow direction of the fluid to be measured in the pipe.
Are arranged to face each other in the vertical direction by being shifted by 180 °. Since these exciting coils 3A and 3B are required to have high insulation and withstand voltage characteristics (1000 V or more), they are wound in a rectangular shape (or a circular ring shape), respectively.
The outside is double-coated with a resin sheet 4 made of polyamide or the like and a glass tape 5, and the glass tape 5
Insulating paint is applied to the surface of the. The exciting coils 3A and 3B having such a structure are formed into a saddle shape, and then positioned and brought into close contact with the outer peripheral surface of the measuring tube 1 by a boss 6 and a plurality of bands 7 and set screws 8 are provided.
Is fixed by. The seat 4 is an exciting coil 3A,
3B is pasted on the surface, and the glass tape 5 is wound on it.

At the center of the measuring tube 1 in the longitudinal direction of the tube wall, the flow direction of the fluid to be measured and the exciting coil 3A,
A pair of electrode insertion holes (not shown) orthogonal to both directions of the magnetic field by 3B are formed so as to coaxially face each other, and electrodes 9A and 9B are fitted and fixed in these insertion holes, respectively. ing. The voltage E generated between the electrodes 9A and 9B is represented by the product of the magnetic flux density B in the tube by the exciting coils 3A and 3B, the average flow velocity V of the fluid to be measured, and the inter-electrode distance d. By detecting, the average flow velocity of the fluid to be measured can be measured.

Reference numeral 10 is a cylindrical core that covers a part or the whole of the exciting coils 3A and 3B, and 11 is a cover that protects the exciting coils 3A and 3B, the electrodes 9A and 9B and the core 10.

[0005]

As described above, since the conventional electromagnetic flowmeter is required to have high insulation and withstand voltage characteristics, the copper wire 12 is wound in a circular shape or a rectangular shape, and the exciting coils 3A and 3B are wound. After that, the coil is curved in a saddle shape with a die, the entire surface is covered with a sheet 4, and a glass tape 5 is further wound on it, and an insulating paint such as epoxy resin is applied to the tape surface and cured. I was letting it. .
However, with the sheet 4 after the coil winding, the exciting coil 3
Since the step of covering A and 3B and the step of winding the glass tape 5 were both performed manually, the workability was very poor. Especially, the winding step of the glass tape 5 was difficult to mechanize, which improved productivity and saved labor. It was a big obstacle.

Further, the exciting coils 3A and 3B are attached to the sheet 4
If the glass tape 5 is covered with the glass tape 5 and the glass tape 5 is wound on the glass tape 5, the outer diameter of the coil becomes large.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its purpose is to cover the sheet 4 with the hand after winding the coil, and to wind the glass tape 5. Is unnecessary, it has excellent workability,
An object of the present invention is to provide a coil structure of an electromagnetic flowmeter and a method of manufacturing the same, which are capable of improving productivity and saving labor.

[0008]

In order to achieve the above object, a coil structure of an electromagnetic flow meter according to the present invention is formed so as to be curved along an outer peripheral surface of a cylindrical measuring pipe, and is arranged to face the outer peripheral surface. In an electromagnetic flowmeter having a pair of saddle-type excitation coils, a pair of insulating papers each including a tubular portion and a flat plate portion provided at one end opening of the tubular portion are provided, and the tubular portion of the pair of insulating papers is provided. Is closely fitted to the inner peripheral surface of the exciting coil, and the flat plate portions of the respective insulating papers are closely contacted with the upper and lower surfaces of the exciting coil, respectively, and the insulating members are provided on the inner peripheral surfaces of the cylindrical portions of the pair of insulating papers. Are fitted to cover the gap between the cylindrical portions.

Further, in the method of manufacturing a coil for an electromagnetic flow meter according to the present invention, the tubular portion of a pair of insulating papers each having a tubular portion and a flat plate portion provided at one end opening portion of the tubular portion is formed into a tubular shape. After fitting the outer peripheral surface of each end of the formed insulating tube and winding a copper wire around the cylindrical portion of the insulating paper and the outer peripheral surface of the insulating tube to form a coil, bond the coil, the insulating paper and the insulating tube. It is bonded and fixed with an agent and then the whole is curved into a saddle shape.

Further, in the method of manufacturing a coil for an electromagnetic flow meter according to the present invention, a copper wire is formed into an elliptical coil, and an adhesive is applied to the upper and lower surfaces and the inner peripheral surface of the coil, and then the tubular portion is formed. The tubular portion of the pair of first insulating papers, which is composed of a flat plate portion provided at one end opening of the tubular portion, is fitted to the inner peripheral surface of the coil so that the flat plate portion closely contacts the upper and lower surfaces of the coil. By doing so, the coil and the first insulating paper are integrally bonded and fixed, and then the coil is curved in a saddle shape, and the second insulating paper formed in a shape corresponding to the inner hole is fitted and closely fixed to the inner hole. It is a thing.

[0011]

In the present invention, the insulating paper and the insulating member for covering the upper and lower surfaces and the inner peripheral surface of the exciting coil insulate the exciting coil from the measuring tube, and the work of covering the coil with a sheet or winding the glass tape by hand. Is unnecessary. The insulating member covers the gap between the tube portions of the pair of insulating papers to provide good insulation,
Get the withstand voltage effect.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The coil structure of an electromagnetic flowmeter according to the present invention and its manufacturing method will be described in detail below with reference to the embodiments shown in the drawings. 1 is a cross-sectional view of a coil unit manufactured by the coil manufacturing method according to claim 2, FIG. 2 is an exploded perspective view of a coil bobbin, and FIG. 3 is a cross-sectional view showing a state in which the coil unit is saddle-shaped and curved. . In these drawings, in this embodiment, a coil unit 21 is composed of a coil bobbin 20 and an exciting coil 3 formed by winding a copper wire around an outer peripheral surface of the coil bobbin 20, and the coil unit 21 is not shown. 3 is curved in a saddle shape as shown by the solid line in FIG. 3, and is in close contact with the outer peripheral surface of the measuring tube 1 (see FIG. 8), and is fixed by an appropriate holder, adhesive or the like.

The coil bobbin 20 is composed of a pair of upper and lower insulating papers 22 having the same shape and an insulating tube 23 as a cylindrical insulating member. The insulating paper 22 has a ring-shaped flat plate portion 22A having a hole 24 in the center and slightly larger than the contour shape of the exciting coil 3, and a cylindrical portion protruding along the hole 24 on one surface of the flat plate portion 22A. 22B and 22B. As the material of the insulating paper 22, an insulating processed Nomex aramid paper having a thickness of about 0.25 mm or the like is used. Both ends of the insulating tube 23 are substantially equal to the inner diameter of the tubular portion 22B of the insulating paper 22,
The central portion forms a large-diameter portion 23a that is substantially equal to the outer diameter of the tubular portion 22B, and the gap between the upper and lower insulating papers 22, 22 is set by this. The coil bobbin 20 as described above is automatically assembled by a machine, and the exciting coil 3 is formed by winding a copper wire around the outer peripheral surface of the cylindrical portion 22B and the large diameter portion of the insulating tube 23 to manufacture the coil unit 21.

As described above, in the coil structure and coil manufacturing method according to the present invention, the coil bobbin 20 is assembled with the pair of insulating papers 22 and the insulating tubes 23, and the exciting coil 3 is formed by winding a copper wire around the outer peripheral surface of the cylindrical portion. The coil unit 21 may be formed into a coil unit 21, and the coil unit 21 may be curved so as to substantially match the curvature of the outer peripheral surface of the measuring tube.
Since there is no need to wind glass tape, the production is simple and easy, and it can be produced by an automatic machine, and the productivity can be greatly improved. Further, in the coil structure according to the present invention, since the inner corners of the coil are wrapped by the tubular portions 22B of the pair of insulating papers 22 and the gap between the tubular portions 22B is covered by the insulating tube 23, it is 100%.
The insulation and withstand voltage effect can be obtained.

FIG. 4 is an exploded perspective view of an exciting coil and a first insulating paper showing a coil manufacturing method according to claim 3, FIG. 5 is a sectional view of the coil formed in a saddle shape, and FIGS. b) is a development view of the second insulating paper and a diagram showing a folded state. In this embodiment, a coil 3 formed of a copper wire in the shape of an ellipse, and a coil unit 31 are formed by the coil 3 and the coil bobbin 30.

The coil bobbin 30 is composed of a pair of upper and lower first insulating papers 32 having the same shape and a second insulating paper 33 as a corrugated (taiko-bashi) strip-shaped insulating member. There is. Similar to the above-described embodiment, the first insulating paper 32 has a rectangular frame-shaped flat plate portion 32A having a rectangular hole 34 at the center and slightly larger than the contour shape of the exciting coil 3, and one surface of the flat plate portion 32A. It is composed of a cylindrical portion 32B protruding in the center. The second insulating paper 33 is folded into a rectangular frame shape, fitted into the tubular portions 32B of the pair of first insulating papers 32, and covers the gap between the tubular portions 32B. First and second insulating paper 3
As the material of 2, 33, an insulating processed thickness of 0.25
Nomex aramid paper of about mm is used.

When manufacturing the coil structure, first, a copper wire is wound to form the elliptical coil 3, and an adhesive is applied to the upper and lower surfaces and the inner peripheral surface thereof. Next, a pair of first insulating papers 32
The cylindrical portion 32B is fitted into the inner hole of the coil 3 from above and below, the flat plate portion 32A is brought into close contact with the upper surface of the coil 3, and the coil 3 and the pair of first insulating papers 32 are integrally bonded and fixed. After that, the coil 3 is curved in a saddle shape, the second insulating paper 33 is bent into a rectangular shape, and the second insulating paper 33 is fitted and inserted into the tubular portion 32B, and closely fixed to the inner peripheral surface of the coil 3.

Also in the coil structure having such a structure, it can be manufactured by an automatic machine as in the above manufacturing method, and the productivity can be greatly improved.

[0019]

As described above, according to the coil structure of the electromagnetic flowmeter and the method of manufacturing the same according to the present invention, it is possible to eliminate steps by manual work, improve workability, save labor, and significantly reduce manufacturing cost. Can be reduced. Also, the insulation and withstand voltage characteristics of the coil are good.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a coil unit manufactured by a coil manufacturing method according to the present invention.

FIG. 2 is an exploded perspective view of a coil bobbin.

FIG. 3 is a cross-sectional view showing a state in which a coil unit is curved and formed in a saddle shape.

FIG. 4 is an exploded perspective view of an exciting coil and a first insulating paper showing another coil manufacturing method according to the invention.

FIG. 5 is a cross-sectional view in which a coil is saddle-shaped and curved.

6 (a) and 6 (b) are a developed view of the second insulating paper and a view showing a folded state.

FIG. 7 is a schematic sectional view of a conventional electromagnetic flow meter.

FIG. 8 is a partially cutaway external perspective view of the electromagnetic flow meter.

[Explanation of symbols]

 1 Measuring Tube 2 Lining 3, 3A, 3B Exciting Coil 9A, 9B Electrode 20 Coil Bobbin 21 Coil Unit 22 Insulating Paper 22A Flat Plate 22B Cylinder 23 Insulating Tube 30 Coil Bobbin 31 Coil Unit 32 First Insulating Paper 33 Second Insulating Paper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuaki Hiroe 4-28-1, Nishirokugo, Ota-ku, Tokyo Yamatake Honeywell Co., Ltd. Kamata factory

Claims (3)

[Claims] 1. An electromagnetic flowmeter having a pair of saddle-type exciting coils, which are curved and formed along an outer peripheral surface of a cylindrical measuring tube, and are arranged to face each other on the outer peripheral surface. A pair of insulating papers, each of which has a flat plate portion provided at an opening of one end of the insulating paper, and the cylindrical portions of the pair of insulating papers are closely fitted to the inner peripheral surface of the exciting coil, respectively. Are closely contacted with the upper and lower surfaces of the exciting coil, respectively, and an insulating member is fitted to the inner peripheral surfaces of the cylindrical portions of the pair of insulating papers to cover the gap between the cylindrical portions. Coil structure of meter. 2. A pair of insulating papers, each of which is composed of a tubular portion and a flat plate portion provided at one end opening of the tubular portion, is fitted to the outer peripheral surface of each end portion of an insulating tube formed in a tubular shape. After wrapping, a copper wire is wound around the cylindrical portion of the insulating paper and the outer peripheral surface of the insulating tube to form a coil, and then the coil, the insulating paper and the insulating tube are bonded and fixed with an adhesive,
A coil manufacturing method for an electromagnetic flow meter, characterized in that the whole is then curved into a saddle shape. 3. A copper wire is formed into an elliptical coil, and an adhesive is applied to the upper and lower surfaces and the inner peripheral surface of the coil, and then a flat portion is provided on the tubular portion and one end opening portion of the tubular portion, respectively. The pair of the first insulating paper consisting of the above is fitted to the inner peripheral surface of the coil, and the flat plate portions are brought into close contact with the upper and lower surfaces of the coil, respectively, to integrally bond the coil and the first insulating paper. A method for manufacturing a coil of an electromagnetic flowmeter, comprising: fixing, then bending the coil in a saddle shape, and fitting and closely fixing a second insulating paper formed in a shape corresponding to the inner hole into the inner hole.