JPH0474931A - Fitting structure of electrode for electromagnetic flowmeter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mounting structure for an electrode for an electromagnetic flowmeter having a sealing surface around the opening of an electrode insertion hole.

[Conventional technology]

In general, an electromagnetic flowmeter is widely known as an instrument that uses Faraday's electromagnetic induction phenomenon to extract an electromotive force proportional to the average flow rate generated in the fluid to be measured (conductive fluid) flowing in a measurement pipe and measure the flow rate. It is being

Conventionally, an electrode mounting structure used in this type of electromagnetic flowmeter is configured as shown in FIG. 13, for example. To explain this based on the same figure, in the same figure, the reference numeral 1 is a stainless steel measurement tube through which the fluid to be measured flows, and is housed in a case (not shown) for an electromagnetic flowmeter. Two through holes 2 (only the negative side is shown) opening inward and outward are provided in the central portion in the axial direction. Further, a boss 3 serving as a cylindrical portion for attaching an electrode, which protrudes from the opening periphery of the through hole 2, is welded and fixed to the outer circumferential surface of the measuring tube 1. Reference numeral 4 denotes a lining made of, for example, Teflon or polyurethane, which is lined around the measuring tube 1 and the boss 3. The lining 4 is formed with an electrode insertion hole 5 having the same axis as the through hole 2 and a flat sealing surface 6 exposed at the opening periphery of the electrode insertion hole 5. Reference numeral 7 designates a pair of electrodes (only one of which is shown) exposed inside the tube, which is attached to the measurement tube 1 so that a portion thereof faces into the electrode insertion hole 5, and which is placed at each point in the fluid to be measured. It is configured to be able to detect electromotive force. A flange 8 that faces the sealing surface 6 is integrally provided on the outer circumferential surface of the electrode 7, and an annular gasket mounting groove 9 is formed in the flange 8 and opens at the end surface of the flange. A gasket 10 made of Teflon is installed in the gasket mounting groove 9 and interposed between the flange 8 and the sealing surface 6. Reference numeral 11 denotes a cylindrical spring retainer with a bottom, which is screwed onto the inner peripheral surface of the opening of the boss 3, and an insertion hole 12 through which the electrode 7 is inserted is provided in the center of the bottom surface. 1
Reference numeral 3 denotes a spring for attaching the electrode, which is elastically mounted between the flange 8 and the spring retainer 11. Also, 1
4 is an insulating ring interposed between the spring 13 and the spring retainer 11; 15 is the spring 13;
and an insulating ring 16 interposed between the flange 8 and the flange 8.
is an insulating sleeve interposed between the spring 13 and the electrode 7. A pair of coils (not shown) are attached to the outer peripheral surface of the measurement tube 1 to form a magnetic field in a direction perpendicular to the flow direction of the fluid to be measured within the tube.

By the way, in this type of electromagnetic flowmeter electrode mounting structure, since the liquid seal is performed by the gasket 10 interposed between the flange 8 and the sealing surface 6, the sealing surface 6 cannot be cut using a lathe. It is formed into a flat surface.

[Problem to be solved by the invention]

However, in the conventional electromagnetic flowmeter electrode mounting structure, the thickness of the lining 4 in the through hole 2 and the thickness of the lining 4 in the boss 3 are subject to space constraints, and the measuring tube 1
The thickness of the inner lining 4 had to be set to be thinner than the thickness of the inner lining 4. As a result, shearing force acts on the lining 4 at the portion where the end surface of the flange 8 contacts during cutting,
There is a problem that the lining 4 in the through hole 2 may be twisted and cut, resulting in a decrease in reliability and productivity in forming the lining.

Therefore, it may be possible to prevent damage to the lining 4 by reducing the amount of cutting of the lining 4 when forming the sealing surface 6, but in this case, the machining speed decreases and a large amount of time is required for machining, which increases costs. There was a problem.

The present invention has been made in view of the above circumstances, and provides a mounting structure for electromagnetic flowmeter electrodes that can improve the reliability and productivity of lining molding and reduce costs. It is something to do.

[Means to solve the problem]

In the electromagnetic flowmeter electrode mounting structure according to the present invention, a punching plate through which the electrode facing the sealing surface is inserted is embedded in the lining, and the punching plate is opposed to the flange.

Further, in the mounting structure of an electrode for an electromagnetic flowmeter according to another aspect of the present invention, a locking portion is provided at a portion where the cylindrical portion and the lining in the through hole are in contact with each other, and a protrusion is locked by the locking portion. is formed integrally with the lining.

[For production]

In the present invention and other aspects of the present invention, it is possible to disperse the circumferential stress acting on the lining during the formation of the sealing surface.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure etc. of this invention will be explained in detail by the Example shown in the figure.

Fig. 1 is a sectional view showing the mounting structure of an electrode for an electromagnetic flowmeter according to the present invention. In the figure and subsequent figures, the same or equivalent members as in Fig. 13 are given the same reference numerals, and detailed explanations are omitted. . In the same figure, the reference numeral 21 is a stainless steel measurement tube through which the fluid to be measured flows, and is housed in a case (not shown) for an electromagnetic flowmeter, with an inner and outer part in the center in the axial direction. Two open through holes 22 (only one shown) are provided. A boss 23 serves as a cylindrical portion for attaching an electrode, and is welded to the measurement tube 21 with a portion facing into the through hole 22. 24 is a lining made of, for example, Teflon, and the through hole 22 is provided on the inner peripheral surface of the measuring tube 21.
The boss 23 is continuously formed so as to extend over the inner circumferential surface of the boss 23, the opening periphery of the boss 23, and a part of the inner circumferential surface of the boss 23. Two electrode insertion holes 25 (only one shown) having the same axis as the through hole 22 are formed in this lining 24 . Furthermore, two electrode mounting surfaces 26 (only the negative side is shown) are formed at the opening peripheries of the picture electrode insertion holes 25 as flat sealing surfaces. Reference numeral 27 denotes a pair of electrodes (only one of which is shown) that is partially exposed inside the tube, and is attached to the measurement tube 21 so that a portion thereof faces into the electrode insertion hole 25.
It is configured to be able to detect the electromotive force generated at each point in the fluid to be measured within the pipe. A flange 28 is integrally provided on the outer circumferential surface of each of these picture electrodes 27 so as to be in contact with the opening periphery of the electrode insertion hole 25. On the end surface of this flange 28, there is an annular gasket mounting groove 29 that opens on the inside of the tube.
is formed. Reference numeral 30 denotes an annular punching plate, which is inserted through the electrode 27 so that its inner peripheral edge faces the flange 28, and is embedded in the lining 24. The outer peripheral edge of the punching plate 30 is fixed to the inner opening end surface of the boss 23 by spot welding.

In such an electromagnetic flowmeter electrode mounting structure, the lining 24 is placed inside the through hole 30a of the punching plate 30.
Since a part of the lining 24 is exposed, the circumferential stress acting on the lining 24 at the time of forming the electrode mounting surface 26 can be dispersed.

Therefore, in this embodiment, even if shearing force is applied to the lining 24 at the portion where the flange end surface of the electrode 27 contacts during cutting, it is possible to prevent the lining 24 from being cut due to twisting within the through hole 22. .

Furthermore, in this embodiment, the circumferential stress acting on the lining 24 during formation of the electrode mounting surface 26 can be dispersed because the thickness of the lining 24 in the through hole 22 can be set to a small dimension. The radial dimension can be shortened.

Furthermore, in this embodiment, there is no need to reduce the amount of cutting due to the dispersion of the circumferential stress acting on the lining 24, so the machining time can also be shortened.

In this embodiment, the punching plate 30 is welded to the inner opening end surface of the boss 23, but
The present invention is not limited to this, and even if a punching plate 31 is welded to the outer peripheral surface of the measuring tube 21 as shown in FIG. 2, the same effects as in the embodiment can be obtained. In this case, the punching plate 31 is attached to the outer peripheral surface of the measuring tube 21 via a spacer (not shown), but there is no problem in attaching the punching plate as shown in FIGS. 3 to 5. do not have. That is, in FIG. 3 (al), a punching plate 35 is directly welded to the opening periphery of the through hole 34 in the measuring tube 33, and in FIG. A punching plate 35 is welded to the periphery of the opening of the through hole 36 in the measuring tube 37. Fig. 4 shows a punching plate 39 welded to the periphery of the outer opening of the through hole 38 in the measuring tube 37. and ('b) are formed by drawing the inner peripheral edge of the punching plate 4041 on the inside of the tube and the outside of the tube, respectively;
tc+ in the figure is a punching plate 42 whose outer peripheral edge is drawn to the outside of the tube.

Next, a mounting structure for an electrode for an electromagnetic flowmeter according to another invention of the present invention will be explained using FIGS. 6 to 1O.

FIG. 6 is a sectional view showing an embodiment of an electromagnetic flowmeter electrode mounting structure according to another invention of the present invention.

In the same figure, four through holes 52 are provided in the circumferential wall of the boss, indicated by reference numeral 51, in parallel at predetermined intervals in the circumferential direction and serving as locking portions for locking protrusions to be described later. These through holes 52 are set at positions spaced apart from the electrode mounting surface 26 by a predetermined height. 53 is the through hole 5
The lining 24 is a protrusion with a circular cross section facing into the lining 24, and is integrally formed with the lining 24.

In this electromagnetic flowmeter electrode mounting structure, since the protrusion 53 faces the through hole 52, the circumferential stress acting on the lining 24 when forming the electrode mounting surface 26 can be dispersed. .

Therefore, in this embodiment, even if shearing force is applied to the lining 24 at the portion where the flange end surface of the electrode 27 contacts during cutting, it is possible to prevent the lining 24 from being cut due to twisting within the through hole 22. .

Furthermore, in this embodiment, the circumferential stress acting on the lining 24 during formation of the electrode mounting surface 26 can be dispersed because the thickness of the lining 24 in the through hole 22 can be set to a small dimension. The radial dimension can be shortened.

Furthermore, in this embodiment, there is no need to reduce the amount of cutting due to the dispersion of the circumferential stress acting on the lining 24, so the machining time can also be shortened.

In this embodiment, the locking portion is a through hole 52, but another aspect of the present invention may be a recessed hole, such as a cutout as shown in FIG. It may be a cutout 53. In this case, the protrusion 54 facing into the notch 53
Since it is positioned at the same height as the lining 24 forming the electrode mounting surface 26, durability against shearing force acting on the lining 24 during cutting can be improved.

Further, in this embodiment, the case where the cross-sectional shape of the protrusion 51 is circular is shown, but in another aspect of the present invention, the cross-sectional shape may be square.

Furthermore, it goes without saying that the number of locking portions in another aspect of the present invention is not limited to the embodiments described above.

In addition, there are other mounting structures for electromagnetic flowmeter electrodes according to the present invention as shown in FIGS. 8 to 12. In FIG. 8, a corrugated locking portion 62 is provided on the inner circumferential surface of the boss indicated by reference numeral 61 by knurling. In this case, as shown in FIG. 9, a large number of grooves 63 extending in the axial direction may be formed on the inner peripheral surface of the boss 61.

Further, in FIG. 10, a corrugated locking portion 72 is provided on the inner circumferential surface of the through hole indicated by reference numeral 71 by performing low left processing. In this case, the locking portion may be a groove 73, 74 extending in the axial direction, as shown in FIGS. 11 and 12.

Furthermore, in FIG. 12, a plurality of grooves 76 extending in the radial direction are provided at the opening periphery of the through hole indicated by reference numeral 75.

〔Effect of the invention〕

As explained above, according to the present invention, the punching plate through which the electrode that is in contact with the sealing surface is inserted is embedded in the lining, and this punching plate is opposed to the flange. Since the lining faces the lining, the circumferential stress acting on the lining when forming the sealing surface can be dispersed. Therefore, even if shearing force is applied to the lining in the area where the flange end faces of the electrode come into contact during cutting, it is possible to prevent the lining from being cut due to twisting within the through hole. Productivity can be increased. Further, since the circumferential stress acting on the lining can be dispersed during the formation of the sealing surface, the thickness of the lining inside the through hole can be set to a small size, which allows the measurement tube to be made smaller. Furthermore, since there is no need to particularly reduce the amount of cutting due to the dispersion of the circumferential stress acting on the lining, the machining speed can be increased and the machining time can be shortened, and costs can also be reduced.

According to another aspect of the present invention, a locking portion is provided at a portion where the cylindrical portion and the lining in the through hole are in contact with each other, and a protrusion that is locked by the locking portion is provided on the lining.
Since the projection faces into the through hole, it is possible to disperse the circumferential stress acting on the lining when forming the sealing surface. Therefore, even if shearing force is applied to the lining in the area where the electrode flange end faces meet during cutting,
Since it is possible to prevent the lining from being cut due to twisting within the through-hole, reliability and productivity in forming the lining can be improved. In addition, being able to disperse the circumferential stress that acts on the lining when forming the sealing surface is
Since the thickness of the lining inside the through hole can be set to a small size, the radial dimension of the electrode can be shortened, and the measurement tube can also be made smaller. Furthermore, since there is no need to particularly reduce the amount of cutting due to the dispersion of the circumferential stress acting on the lining, there is an advantage that the machining speed can be increased and the machining time can be shortened, resulting in lower costs.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a mounting structure of an electrode for an electromagnetic flowmeter according to the present invention, FIGS. 2 to 5 are cross-sectional views showing other embodiments of the present invention, and FIG. 6 is a cross-sectional view showing another embodiment of the present invention. A sectional view showing a mounting structure of an electrode for an electromagnetic flowmeter according to the invention, FIGS. 7 to 12 are sectional views showing other embodiments of another invention of the invention,
FIG. 13 is a sectional view showing a conventional electromagnetic flowmeter electrode mounting structure. 10...Gasket, 21...Measuring tube, 22...
... Through hole, 23 ... Boss, 24 ... Lining, 25 ... Electrode insertion hole, 2660.・Electrode mounting surface, 27...electrode, 28...flange, 30...
...Punching plate.

Claims (2)

[Claims] (1) A measuring tube that has a through hole that opens inwardly and outwardly and a cylindrical portion for attaching an electrode that protrudes from the opening periphery of the through hole in its axial center, and the through hole that is lined with the measuring tube and the cylindrical portion. an electrode insertion hole having the same axis as the axis of the electrode insertion hole, a lining having a sealing surface exposed at the opening periphery of the electrode insertion hole, and a flange installed in the electrode insertion hole of the lining and facing the sealing surface via a gasket. An electromagnetic flowmeter electrode mounting structure comprising: an electromagnetic flowmeter electrode mounting structure, characterized in that a punching plate through which the electrode is inserted is embedded in the lining, and the punching plate is opposed to the flange. Mounting structure of the electrode. (2) A measurement tube that has a through hole that opens inwardly and outwardly, and a cylindrical portion for attaching an electrode that protrudes from the opening periphery of the through hole in its axial center, and the through hole that is lined with the measuring tube and the cylindrical portion. an electrode insertion hole having the same axis as the axis of the electrode insertion hole, a lining having a sealing surface exposed at the opening periphery of the electrode insertion hole, and a flange installed in the electrode insertion hole of the lining and facing the sealing surface via a gasket. In the electromagnetic flowmeter electrode mounting structure, a locking portion is provided at a portion of the lining where the cylindrical portion and the lining in the through hole are in contact with each other, and the electrode is locked by the locking portion. A mounting structure for an electrode for an electromagnetic flowmeter, characterized in that a protrusion is integrally formed with the lining.