JPH01257220A - Electromagnetic flowmeter and manufacture thereof - Google Patents

Abstract

PURPOSE:To achieve a higher workability of assembling work, by solidifying integrally an exciting coil, a base plate and a magnetic plate by an insulation film material to be fixed on the outer circumference of a measuring tube. CONSTITUTION:An exciting coil 3A, a base plate 20 and a magnetic plate 21 are solidified by an insulation film material to be utilized and fixed on the outer circumference of a measuring tube 1 by a plurality of a clamping means 24. In this manner, the exciting coil 3A, base plate 20 and magnetic plate 21 are arranged in layers, which allows the formation of these three parts being curved simultaneously along the outer circumference of the measuring tube 1 with male and female dies. This can wave working processes thereby achieving a higher workability with a reduction in the number of parts.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electromagnetic flowmeter and a method of manufacturing the same.

[Prior Art J] An electromagnetic flowmeter uses Faraday's electromagnetic induction phenomenon to electrically measure the flow rate t of a conductive fluid flowing in a measuring tube, and generally, as shown in Figs. 6 and 7. It is configured. In other words, 1 has connecting piping flanges 1 on both ends.
．． A and 1b are integrally provided, and the entire inner circumferential surface is coated with an insulating lining 2 made of, for example, Teflon, neoprene (both are trademarks). A pair of excitation coils 3 A + 3 B that generate a magnetic field in a direction perpendicular to the fluid flow direction are arranged to face each other in the vertical direction. These excitation coils 3
A.

3B are each formed in a saddle shape, and a plurality of, for example, four bands 4 and a set screw 5 are used to attach the post 1 to the outer peripheral surface of the measuring tube 1.
Fixed via 0. The boss 11 is welded and fixed to the outer peripheral surface of the measuring tube 1, and has a screw hole into which the set screw 5 is screwed. The band 4 is formed by bending a metal plate into a substantially -n-shape, straddles the excitation coils 3A and 3B, and its entire growing surface is covered with an insulating member (not shown).
Furthermore, an insulating paper 9 is interposed on the lower surface.

Further, in the longitudinal center portion of the tube wall of the measurement tube 1, there are provided the flow direction of the fluid to be measured and the excitation coil 3A.

A pair of electrode insertion holes (not shown) which are orthogonal to both directions of the magnetic field generated by 3B are formed through the electrodes so as to face each other on the left and right sides, and electrodes 6A and 6B are respectively attached to these insertion holes. The inner end face faces into the measuring tube 1 and forms a wetted space. The voltage E generated between the picture electrodes 6 and 6B is the excitation coil 3A.

It is expressed as the product of the magnetic flux density (B) in the pipe due to 3B, the average flow velocity of the fluid to be measured (, V), and the distance between the electrodes (d), so by detecting one voltage E, the average flow velocity of the fluid to be measured can be calculated. can be measured.

T is a core formed in a cylindrical shape and covering part (or the whole) of the excitation coils 3A and 3B, and this core 7 is fixed to the outer peripheral surface of the measurement tube 1 by fastening means (not shown) such as a set screw. ing. 8 is excitation coil 3A, 3B, electrode 6A, 6
B and core T' (+- protective case).

[Problem to be solved by the invention]

However, such a conventional electromagnetic flowmeter requires a plurality of bands 4, set screws 5 for fixing the bands 4, set screws for fixing the core 7, etc., and therefore has a large number of parts. However, there was a problem in that the workability during assembly was extremely poor. In addition, the measurement tube has a curvature of 10 and an excitation coil of 3A.

If the curvature of 3B does not match, excitation coil 3 will be removed in band 4.
Even if A and 3B are pressed, parts other than the part pressed by the band 4 may float from the outer peripheral surface of the measuring tube 1, which poses a problem in response to the demand for thinner excitation coils.

Also, excitation coil 3A.

3B is curved along the outer circumferential surface of the measuring tube 1, so it tends to float up from the measuring tube 1 due to its springback, and the number of the bands 4 is increased to completely prevent the occurrence of this springback. Although it is possible,
This increases the number of man-hours required for layer assembly.

Therefore, the present invention provides an electromagnetic flowmeter and its manufacturing method that can solve the above-mentioned nine problems, can securely fix the excitation coil to the outer wall of the measuring tube with a simple structure, and can save the number of parts and work man-hours. The purpose is to provide

[Means to solve the problem]

In order to achieve the above object, the electromagnetic flowmeter according to the present invention has the following features:
A measuring tube, nine pairs of exciting coils curved along the outer peripheral surface of the measuring tube and arranged opposite to the outer peripheral surface, and a non-magnetic material interposed between each exciting coil and the measuring tube. and a pair of magnetic plates that cover at least a portion of the surface of each of the excitation coils and are fixed to the outer peripheral surface of the measurement tube together with the excitation coil, The pace plate and the magnetic plate corresponding to the five coils are integrally bonded to each other by covering their entire surfaces with an insulating coating material.

Further, the method for manufacturing an electromagnetic flowmeter according to the present invention includes stacking and arranging a magnetic plate, an excitation coil, and a pace plate each formed in a flat plate shape on a female mold in this order,
Next, these three members are press-fitted into the recessed part of the female mold using a male mold to form a curve along the outer peripheral surface of the measurement tube,
Next, the three members are taken out from the female mold and immersed in a molten insulating coating material, and then the insulating coating material is dried and solidified to integrate the three members and fixed to the outer peripheral surface of the measuring tube. I did it like that.

[Effect]

In the electromagnetic flowmeter according to the present invention, the pace plate and the magnetic plate sandwich the excitation coil to prevent springback thereof.

In addition, in the method for manufacturing an electromagnetic flowmeter according to the present invention, the three members of the pace plate, the excitation coil, and the magnetic plate are coated with an insulating coating material and are integrally connected, so that the outer circumferential surface of the measuring tube They will be installed at the same time.

Embodiments The present invention will now be described in detail based on embodiments shown in the drawings.

FIG. 1 is a perspective view showing an embodiment of an electromagnetic flowmeter according to the present invention, FIG. 2 is a plan view of the mounting part, and FIG. 3 is a sectional view. In the figure, two parts that are the same as those in FIGS. 6 and 7 are designated by the same reference numerals, and their explanations will be omitted. In these figures, in this embodiment, an excitation coil 3A, a base plate 20, and a magnetic plate 21 are hardened with an insulating coating material 22 to form a coil unit 23, and a plurality of coil units 23 are installed on the outer peripheral surface of the measuring tube 1. It is fixed by the fastening means 24 of.

The base plate 20 is made of a non-magnetic material such as stainless steel, and is curved with a radius between the outer circumferential surface and the path so as to be in close contact with the outer circumferential surface of the measuring tube 1, and the excitation coil 3A is placed on it. . The three excitation coils are wound in a square or rectangular shape and are curved in an arc shape so as to closely contact the surface of the base plate 200, thereby forming an F:J saddle shape.

The magnetic plate 21 is made of soft iron or the like and constitutes the outer core of the excitation coil 3A, and has a central curved base 21A curved in an arc shape with a radius between the surface of the base plate 20 and the path. , substantially hook-shaped (5-shaped) coil fixing portions 21B extending integrally at both ends in the circumferential direction of the central/front curved base portion 21A,
21C. The central curved base 21A is inserted into the central opening 25 of the excitation coil 3A and brought into close contact with the surface of the base plate 200. Each of the coil fixing parts 218 and 210 covers the surface of the linear part 27 extending in the axial direction of the three excitation coils, and preferably has an even-odd shape inward so as to elastically press the direct part 2T. It has a habit.

The fastening means 24 includes a plurality of fastening means 24, for example, four fastening means 24, which are protruding from the outer circumferential surface of the measurement tube 1 and inserted into insertion holes (not shown) provided in the base plate 20 and the magnetic plate 21.
The stand bolt 28 includes a stud bolt 28 and a nut 29 which is screwed onto the tip of the stand bolt 28 and fastens the base plate 20 and the magnetic plate 21 to the measuring tube 1 together. Furthermore, both ends of the base plate 20 in the circumferential direction are fixed to the measurement tube 1 by fastening means 30 (stud bolts 30 and 30B) similar to those described above.

As the insulating coating material 22 for integrally solidifying the three members of the excitation coil 3A, the base plate 2o, and the magnetic plate 21, thermoplastic resin or the like is used, for example. It covers the entire excitation coil 3A and prevents the excitation coil 3A from coming apart.

Springback of the base plate 20 and the magnetic plate 21 is prevented. Note that illustration of the insulating coating material 22 is omitted in FIGS. 1 and 3.

When manufacturing the coil unit 23, as shown in FIG. 4, three excitation coils wound in a flat plate shape are placed on a magnetic plate 21 formed in a flat plate shape, and a flat base plate is placed on top of the excitation coils. 20, these three members are placed on the female deaf mold 31, and the male metal powder 32 is press-fitted into the concave part 33 of the female mold 31 to simultaneously bend them into a predetermined shape. The three members are taken out from the concave portion 33 and immersed in a face liquid tank, and then placed in a heating furnace and heated at a constant temperature (approximately 150°C) for a predetermined period of time (14 to 15 hours) to solidify the face. Bye. Then, the coil unit 23 manufactured in this way is brought into close contact with the outer peripheral surface of the measuring tube 1 and fixed by the fastening means 24.degree. 30, thereby completing the installation of the coil unit 23.

The other excitation coil 3B, which is disposed on the outer circumferential surface of the measurement tube 1 so as to face the three excitation coils, is manufactured in exactly the same manner as the three excitation coils, and therefore its description will be omitted.

Thus, according to the electromagnetic flowmeter having such a configuration,
Since the excitation coil 3A is held between the paste plate 20 and the magnetic plate 21, and the magnetic plate 21 also serves as the core of the three coils, the number of parts can be reduced, and the three members 3A, 20° 21 Since they are integrally connected by an insulating coating material 22 such as varnish, assembly can save man-hours, improve assembly workability, and reduce costs.

In addition, since the coil unit 23 is hardened by the insulating coating material 22, it has a large shape retention force, effectively prevents springback, and is less likely to rise up from the outer circumferential surface of the measuring tube 1, so there is no space for storing the coil. Make smaller.

FIGS. 5(1) and 5(b) are a plan view and a sectional view showing another embodiment of the present invention. In this embodiment, the magnetic plate 21 covers the entire surface of the excitation coil 3A? C has a sufficient size and is curved with the curvature between the surface and the path, and both ends in the circumferential direction are straight parts 2T of the three exciting coils.
It is bent along the outer surface of the pace plate 20 and is fixed on both circumferential end surfaces of the pace plate 20 by fastening means 24 . The other configurations are the same as those of the above embodiment.

In such a configuration, the rigidity of the coil unit 23 is increased by the magnetic plate 21, and the force of retaining the layered shape is large, and springback of the three exciting coils can be more reliably prevented.

In the above embodiments, the coil unit 23 is fixed by the fastening means 24 and 30, but the fastening means 24 and 30 are not limited to this, and it goes without saying that an adhesive may also be used.

〔Effect of the invention〕

As explained above and as follows, according to the electromagnetic flowmeter according to the present invention,
A support coil, a pace plate, and a magnetic plate, which are curved to fit around the outer circumference of the measuring tube, are integrally solidified with an insulating coating material to form a unit, and this unit is fixed to the outer circumferential surface of the measuring tube. Therefore, the structure is simple and the number of parts is small, so assembly work can be easily and quickly performed, improving workability. In addition, the coil unit has a large shape retention force, prevents springback of the excitation coil, and makes it possible to reduce the storage space for the coil.

! ! In addition, in the manufacturing method according to the present invention, the pace plate, the excitation coil, and the magnetic plate are arranged in a stacked manner,
Since these king tmu metal shield and female plate metal IIK are simultaneously curved along the outer circumferential surface of the measuring tube,
The number of work steps can be reduced.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing an embodiment of the electromagnetic flowmeter according to the present invention, Fig. 2 is a plan view of the main part, Fig. 3 is a sectional view, and Fig. 4 is for explaining the method of manufacturing the coil unit. Figure 5
1(b) are a plan view and a sectional view of main parts showing another embodiment of the present invention, and FIG. 6 is an enlarged sectional view and a perspective view showing a conventional electric V&flow meter. 1...Measuring tube, 211...-Lining, 3A, 3
B...Jlil magnetic coil, 4...Band, 6A
, 6B...electrode, 7...-core, a...case, 20.O-pace plate, 21...magnetic plate, 22...insulating coating material, 23. +1-・
Coil unit, 24.30... fastening means, 31.
Φ...male mold, 32...male mold.

Claims (2)

[Claims] (1) a measuring tube; a pair of excitation coils curved along the outer circumferential surface of the measuring tube and disposed opposite to the outer circumferential surface;
A pair of base plates made of a non-magnetic material are interposed between each excitation coil and the measurement tube, and the base plate covers at least a portion of the surface of each excitation coil and is fixed to the outer peripheral surface of the measurement tube together with the base plate. A pair of magnetic plates, and the excitation coil, the base plate corresponding to the coil, and the magnetic plate are integrally coupled by covering the entire surface thereof with an insulating coating material. An electromagnetic flow meter. (2) A magnetic plate, an excitation coil, and a base plate, each formed in a flat plate shape, are stacked in this order on the female mold, and then these three members are placed in the female mold using a male mold. Press fit into the recess to form a curve along the outer circumferential surface of the measuring tube, then take out the three members from the female mold and immerse them in the molten insulation coating material, and then dry and solidify the insulation coating material. to integrate the three members,
A method of manufacturing an electromagnetic flowmeter, characterized in that the electromagnetic flowmeter is fixed to the outer peripheral surface of the measurement tube.