JPH0527628U - Electromagnetic flow meter - Google Patents

Abstract

(57) [Summary] [Purpose] The objective is to reduce the number of welding points, improve the workability of welding, and make it easy to fabricate a perforated pipe and easily position it on the measuring pipe. To do. [Structure] A porous tube 20 is embedded coaxially with the measuring tube 4 in a lining material 2 on an inner wall surface of the measuring tube 4, and an end portion of the porous tube 20 is divided in a circumferential direction by forming a slit to be perpendicular to the outside. A plurality of bent piece portions 21 are formed by bending, and the bent piece portions 21 are embedded in the lining material of the flange end surface portion. Further, the spacer 22 having the step portion 23 on the flange end face is arranged and fixed coaxially with the measuring tube 4, and the bent piece portion 21 is fitted into the step portion 23 to position and hold the porous tube 20.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electromagnetic flow meter for measuring the flow rate of a conductive fluid flowing in a measuring pipe.

[0002]

[Prior Art]

 An electromagnetic flowmeter (Jpn. Pat. Appln. KOKAI HEI 2-28411, etc.) measures the flow rate of a conductive fluid flowing in a measuring tube by utilizing the principle of electromagnetic induction, and detects the electromotive force generated in the fluid. In order to prevent short circuits with measuring tubes made of non-magnetic material such as stainless steel, the inner wall surface of the measuring tube and the outer surface of the flange are usually covered with a lining material. Since the material of the lining material is required to have excellent heat resistance, corrosion resistance, and insulation, an insulating material such as fluororesin is usually used. Lined in. However, since the lining material made of fluororesin has poor adhesion to the metal and therefore easily peels off from the measuring tube, the porous tube 1 made of SUS or the like is usually embedded in the lining material 2 as shown in FIG. However, the lining material 2 is prevented from peeling off (Japanese Utility Model Publication No. 2260/260). In this case, the perforated pipe 1 includes a non-magnetic cylindrical body 1A arranged coaxially in the measuring pipe 4, and flanges 4A, 4B of the measuring pipe 4 integrally provided at both ends of the cylindrical body 1A. And a porous plate 1B, 1C made of a magnetic material facing in parallel with each other. The cylindrical body 1A and the multi-hole discs 1B, 1C are welded and fixed to a spacer 3 provided on the inner wall surface of the measuring tube 4 and the flange end surface. ing. The porous discs 1B and 1C prevent the lining material 2 covering the flange end surface from peeling off, and the magnetic flux of the exciting coil 5 leaks from the flanges 4A and 4B along the axial direction of the measuring tube 4. Prevent. Reference numeral 6 denotes a pair of electrodes (only one of which is shown), which are provided so as to penetrate through the center of the tube wall of the measuring tube 4 so as to be orthogonal to the magnetic field generated by the exciting coil 5, 7 denotes a core which covers the outer circumference of the exciting coil 5, and 8 denotes A signal lead wire of the electrode 6 and a cover 9 for covering the outer circumference of the measuring tube 4.

[0003]

However, in the above-described conventional electromagnetic flowmeter, the spacer 3 and the porous discs 1B, 1C or the cylindrical body 1A are welded first, and then the measuring tube 4 is welded. However, there is a problem that it is necessary to perform the welding work twice, which requires a large number of man-hours. Further, since it is necessary to separately manufacture the cylindrical body 1A and the perforated circular plates 1B and 1C as the perforated tube 1, there is also a problem that the perforated tube 1 is cumbersome and expensive to manufacture.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to reduce the number of welding points, improve the workability of welding, and manufacture a perforated pipe. It is an object of the present invention to provide an electromagnetic flow meter which is simple and can be easily positioned with respect to a measuring tube.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention has a measuring tube formed in a cylindrical shape and having flanges on both outer circumferences, and an inner wall surface of the measuring tube and an outer surface of the flange. And a lining material that covers the inner wall surface of the measuring tube and the outer side surface of the flange to mold the porous tube, and a step portion is provided on the outer side surface of the flange coaxially with the measuring tube. The pipe is formed to be longer than the measuring pipe, and both ends are bent outward by forming a plurality of slits, thereby forming a plurality of bent pieces facing the outer surface of the flange, and the tip thereof. The portion is fitted and held in the step portion.

[0006]

[Action]

 In the present invention, the slit divides the end portion of the perforated pipe in the circumferential direction, and enables formation of a bent piece portion. The perforated pipe is positioned and held by fitting the bent piece into the stepped portion provided on the end face of the flange.

[0007]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is a sectional view of an electromagnetic flowmeter according to the present invention, and FIG. 2 is a perspective view of a perforated tube and a spacer. In the figure, the same components as those in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted. In this embodiment, the porous tube 20 is formed by one member. A plurality of, for example, eight bent piece portions 21 that are bent at right angles to the outside are integrally provided at both ends of the porous tube 20, and the tip end portions of these bent piece portions 21 are the outer surfaces of the flanges 4A, 4B. The perforated tube 20 is positioned by being fitted to the surface of the spacer 22 fixed to the surface, that is, the step portion 23 formed on the side surface opposite to the flange, and the center of the perforated tube 20 is aligned with the center of the measuring tube 4. There is. The bent piece portion 21 can be bent by forming a plurality of slits 24, which are long in the axial direction, at the ends of the perforated tube 20 at appropriate intervals in the circumferential direction. The slit 24 is expanded in a V shape by bending the bending piece portion 21. The spacer 22 is formed in a ring shape, and an annular step portion 23 is formed on the inner peripheral edge of the surface. The diameter of the step portion 23 is substantially equal to the diameter of the bent piece portion 21. The spacer 22 is welded and fixed to the outer surface of each of the flanges 4A and 4B coaxially with the measuring pipe 4.

Thus, in the electromagnetic flowmeter having such a configuration, the bent piece portions 21 integrally provided at both end portions of the perforated pipe 20 are fitted into the step portions 23 of the spacer 22 to make the perforated pipe 2 Since 0 is positioned and held, there is no need to purposely weld and fix the perforated tube 20 to the spacer 22, and the work of attaching the perforated tube 20 to the measuring tube 4 is simple and easy, and the workability can be improved. Further, since the perforated tube 20 itself is manufactured by one member, the perforated tube 20 can be easily manufactured. Further, the spacer 22 positions and holds the porous tube 20 to center the porous tube 20, and sets an appropriate gap between the inner wall surface and the flange end surface of the measuring tube 4 and the porous tube 20. It allows the plugging material 2 to wrap around between the perforated tube 21 and the measuring tube 4.

FIG. 3 is a cross-sectional view of an essential part showing another embodiment of the present invention. In this embodiment, a step portion 23 is directly provided on the outer surface of the flange 4A (similarly to 4B), and the tip portion 21a of the bending piece portion 21 is bent to the back surface side in a substantially hook shape (L shape), The tip portion 21a is fitted in the step portion 23. In addition, 26 is a welded portion of the measuring pipe 4 and the flange 4A. Since a spacer is not required in such a configuration, the number of parts is smaller than that of the above-described embodiment, and there is an advantage that the structure of the electromagnetic flow meter can be further simplified.

[0010]

[Effect of the device]

 As described above, according to the electromagnetic flowmeter of the present invention, the end of the perforated pipe is bent outward by forming a slit, and the bent piece is formed on the stepped portion provided on the flange end face of the measuring pipe. Since they are fitted and fixed, there is no need to bother welding and fixing the perforated pipe, the work of attaching the perforated pipe to the measuring pipe is simple and easy, and the number of work steps can be reduced. When the bent piece is fitted, the perforated pipe can be coaxially arranged with respect to the measurement pipe, so that the positioning and adjustment work of the perforated pipe is simple and easy. Furthermore, since the perforated pipe can be manufactured by one member, the perforated pipe can be easily manufactured and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an electromagnetic flow meter according to the present invention.

FIG. 2 is a perspective view of a perforated tube and a spacer.

FIG. 3 is a cross-sectional view of an essential part showing another embodiment of the present invention.

FIG. 4 is a sectional view of a conventional electromagnetic flow meter.

[Explanation of symbols]

 1 Perforated Tube 2 Lining Material 3 Spacer 4 Measuring Tube 4A, 4B Flange 5 Excitation Coil 6 Electrode 20 Perforated Tube 21 Bent Piece 22 Spacer 23 Stepped Section 24 Slit

Claims (1)

[Scope of utility model registration request] 1. A measuring tube which is formed in a cylindrical shape and has flanges on both outer circumferences, and a perforated tube which is arranged along the inner wall surface and the outer surface of the flange of the measuring tube at appropriate intervals. A lining material that covers the inner wall surface of the measurement pipe and the flange outer surface and molds the perforated pipe, wherein a step portion is provided on the flange outer surface coaxially with the measurement pipe, and the perforated pipe is the measurement pipe. A plurality of bent pieces are formed to be longer and both ends are bent outward by forming a plurality of slits to form a plurality of bent pieces facing the outer surface of the flange, and the tips of the bent pieces are fitted to the stepped portion. An electromagnetic flowmeter characterized by being held together.