JPH0623936Y2 - Electromagnetic flow meter electrode structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an electrode part structure of an electromagnetic flow meter, and more particularly to an electrode part structure of an electromagnetic flow meter with improved insulation performance of the electrode part.

<Prior Art> FIG. 2 is a longitudinal sectional view showing a structure of an electrode part of a conventional electromagnetic flowmeter presented in Japanese Patent Application No. 62-86888 "Electrode Flowmeter Electrode Structure".

Reference numeral 22 denotes a cylindrical conduit, a hole 23 is formed in a part thereof, a metal ring 24 is fixed by welding around the hole 23, and a screw portion 25 is formed at an outer end portion thereof.

Reference numeral 26 denotes a lining material molded on the inner surface of the conduit 22, which extends through the hole 23 to the outer bottom surface 27 of the conduit 22 and rises along the side surface of the ring 24. The lining portion covering the outer bottom surface 27 forms an electrode seal portion 28.

Reference numeral 29 denotes a measurement electrode, which has a rod-shaped liquid contact portion 30, a flange-shaped flange portion 31 provided on the upper portion thereof, a rod-shaped connection portion 32 provided on the upper portion of the flange portion 31, and the periphery thereof. Except for the tip of the portion 30, it is coated with a thermoplastic insulating material 33 such as PFA resin.

Further, a lead wire 35 covered with a thermoplastic insulating material 34 such as PFA is connected to the outer end of the connecting portion 32, and the insulating material 34 and the insulating material 33 on the outer periphery of the lead wire 35 are made of the same material as these and are integrally formed. It is melted and coated.

When PFA resin is used as the coating material, the lead wire 35 is connected to the connecting portion 32 of the measuring electrode 29 to form the liquid contact portion 30 excluding the tip of the liquid contact portion 30, the flange portion 31, and the outer periphery of the connecting portion 32. A PFA resin is coated on the outer periphery of the lead wire 35, and the temperature is raised to, for example, about 350 ° C. to melt the PFA resin and the PFA resin is integrally coated.

The measurement electrode 29 formed in this manner is inserted into an insertion hole 36 formed in the lining material concentrically with the hole 23,
The measurement electrode 29 is liquid-sealed by pressing the electrode seal portion 28 via the spring 38 with a plug 37 having a hole through which the lead wire 35 penetrates in the center of the upper portion of the flange portion 31.

With such a configuration, the measurement electrode and the portion connected to the measurement electrode are completely covered with an insulating material, which is an effective measure against dew condensation.

However, the electrode structure of the electromagnetic flowmeter shown in FIG. 2 has the following problems.

The lead wire and the measurement electrode are partly left and fused together with an insulating material for coating, but pinholes are easily formed at these connections, and the measurement electrode is relatively heavier than the lead wire. Are connected as a unit, they are likely to be damaged at these connecting portions. Also, the potting material is filled around the conduit, but in such a case, the potting material enters the inside of the ring and the spring does not function sufficiently.

Therefore, in order to solve this problem, the present applicant
On the 24th of the month, Japanese Utility Model Application No. 62-113432 "Electrode Flowmeter Electrode Structure" is presented.

The contents will be described below with reference to FIG. It should be noted that parts having the same functions as those of the components shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be appropriately omitted.

Reference numeral 39 denotes a measurement electrode, which has a rod-shaped liquid contact portion 40, a flange-shaped flange portion 41 provided on the upper portion thereof, a rod-shaped connection portion 42 provided on the upper portion of the flange portion 41, and the periphery thereof. Except for the tip of the portion 40 and the connecting portion 42, it is coated with a thermoplastic insulating material 43 such as PFA resin.

Reference numeral 44 denotes a cap, the peripheral portion of which is threadedly engaged with the threaded portion 25 of the ring 24, and the central portion thereof is provided with a tapered enlarged portion 45 and a penetrating portion 46 which are enlarged inward.

Reference numeral 46 is a lead wire for taking out a signal voltage, which has a conducting wire 47 inside and is covered with an insulating material 48 on the outside.
One end of 7 is connected to the connecting portion 42 of the measuring electrode 39.

Enlarging portion 45 of cap 44 and connecting portion 42 of measuring electrode 39
An elastic material 49 made of rubber or the like is disposed between the and. The elastic material 49 has a tapered outer end, and a through hole through which the lead wire 46 penetrates is formed at the center of the inside of the elastic material 49.

A spring 38 is arranged between the inner surface of the cap 44 and the flange portion 41 of the measuring electrode 39, and the measuring electrode 39 is attached to the electrode seal portion 28 via the spring 38 by screwing the cap 44 into the screw portion 25. In addition to pressing, the connecting portion 42 of the measuring electrode 39 is also pressed via the elastic material 49. Therefore, the lead wire 46 is clamped from the outside, the gap formed between the conductor wire 47 and the insulating material 48 is crushed, and moisture entering between the lead wire 46 and the insulating material 48 is blocked, and between the insulating material 48 and the elastic material 49. Water entering is also blocked. Furthermore, the connection between the lead wire 46 and the measuring electrode 39 is also sealed at the same time. Further, even if the potting material is injected from the outside of the conduit 22, it is blocked by the elastic material 49 and the ring 24
Since it does not enter inside, the function of the spring does not deteriorate.

<Problems to be Solved by the Invention> However, the electrode structure of the electromagnetic flowmeter shown in FIG. 3 has a reel defect at the connecting portion between the measuring electrode and the lead wire as compared with the structure of the electrode portion shown in FIG. Although it has the advantage that damage can be removed and that moisture that has entered between the lead wire and the insulating material that covers the lead wire can be removed, there are drawbacks as described below.

First, the outer shape of the measuring electrode 39 near the connecting portion 42 for connecting the lead wire 46 is complicated and the measuring electrode 3
Since the coating film of the insulating material 43 coated on the surface of the insulating material 9 is extremely thin, insulation deterioration is likely to occur at this portion due to pinholes or the like generated when the insulating material 43 is coated.

Secondly, when the surface of the flange portion 41 is pressed by the spring 38, the thin insulating material 43 covering the measuring electrode 39 in the vicinity of the spring 38 is apt to be damaged by the spring, which causes insulation deterioration due to dew condensation or the like. Cheap.

There are problems such as.

<Means for Solving the Problems> In order to solve the above problems, the present invention has a lining material formed on the inner peripheral surface of a conduit extended to the outside of the conduit through a hole formed in the conduit. Then, an electrode seal portion is formed, and the electrode seal portion has a signal line insertion hole at the center so that the lower surface of the flange portion is inserted into an insertion hole bored in the direction of the central axis of the conduit to contact the electrode seal portion. In the electrode part structure of the electromagnetic flowmeter having the measuring electrode pressed by the sprinkle through the cap, the measuring electrode is coated with the thermoplastic resin, leaving the connection part between the liquid contact part at the inner end and the signal line at the outer end. The insulating cap having the first pressing portion that is provided and is in contact with the flange portion and the second pressing portion that is integrated with the first pressing portion and has the opening through which the signal line penetrates is formed in the center by the spring. Pressed, the second pressing part Is pressed by an elastic body with a through hole in the center, the signal wire of the insulation coating connected to the outer end is pulled out through the through hole, and the cap is pressed toward the measurement electrode side to separate the signal wire and the measurement electrode. The outer end is sealed at the same time.

<Operation> The measurement electrode whose surface is coated with an insulating material is covered with an insulating cap, leaving the liquid contact part and the outer end, and the first pressing part of this insulating cap is a spring and the second pressing part is centered. Protect the thin insulating material that coats the measurement electrode by covering the lead wire with an elastic material that has a through hole, covering it with an elastic material that passes through the through hole, and pressing these with a cap to seal the liquid. , Keep good insulation as a whole.

<Embodiment> FIG. 1 is a vertical sectional view showing the construction of an embodiment of the present invention.

Reference numeral 50 denotes a measuring electrode, which is a rod-shaped liquid contact portion 51, a flange-shaped flange portion 52 provided on the upper portion thereof, and a cylindrical connection portion 53 provided at the center of the flange portion 52.
And is coated with a thermoplastic insulating material 54 such as PFA resin except for the tip of the liquid contact part 51 and the connection part 53.

Reference numeral 55 denotes an insulating cap, which is integrally formed with the ring-shaped pressing portion 56, has a cylindrical portion 57 formed vertically on the inner peripheral portion thereof, and further has an opening 58 in the center so as to close the outer periphery of the cylindrical portion 57. A pressing portion 59 is formed. The pressing portion 56 of the insulating cap 55 is pressed and sealed to the flange portion 52 by the spring 38.

Reference numeral 60 denotes an elastic material that presses the pressing portion 59. A through hole 61 that penetrates the lead wire 46 is bored in the center of the elastic material 60, one end of which is a conical portion 62 formed into a conical shape, and the other end is Is a flat portion 63.

The lead wire 46 is inserted into the through hole 61 and connected to the measurement electrode 50 at the connection portion 53, and the cap 44 presses the elastic member 60 and the spring 38 to seal between them.
At this time, the elastic member 60 is pressed by the conical portion 62 to hermetically seal between the lead wire 46 and the elastic member 60.

The elastic material 60, the insulating cap 55, and the insulating material 54 block the internal space including the connecting portion 53 and the external space including the spring 38, and even when water is infiltrated into the lead wire 46, the measuring electrode 50 and the conduit 22 are prevented. The insulation between them is secured. Further, the insulation between the measuring electrode 50 and the conduit 22 is ensured even if the internal space and the external space are condensed.

Therefore, it is possible to realize an electrode structure in which the insulation between the measurement electrode 50 and the conduit 22 is maintained and the function as the measurement electrode is satisfied regardless of the place where water or water is condensed.

<Effect of the Invention> As described above in detail with the embodiments, according to the present invention, the flange portion 52 of the measuring electrode 50 is attached to the insulating cap 5.
Since the pressing portion 56 is pressed by the spring 38 outside the cylindrical portion 57 of the insulating cap 55, the insulating material 54 of the measuring electrode 50 is inserted when the spring 38 is inserted.
There is no need to worry about damaging the measuring electrode 50 and the connecting portion 53 of the measuring electrode 50.
Insulation can be secured even if the side insulating material 54 has a pinhole or the like.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing the construction of one embodiment of the present invention, and FIG.
FIG. 3 is a vertical sectional view showing a structure of an electrode portion of a conventional first electromagnetic flow meter, and FIG. 3 is a vertical sectional view showing a structure of an electrode portion of a conventional second electromagnetic flow meter. 22 ... Conduit, 26 ... Lining material, 29 ... Measuring electrode, 33 ... Insulating material, 38 ... Spring, 39 ... Measuring electrode, 44 ... Cap, 50 ... Measuring electrode, 51 ...
… Wetted part, 52 …… Flange part, 53 …… Connecting part, 54
…… Insulation material, 55 …… Insulation cap, 56 …… Pressing part,
58 ... Opening, 59 ... Pressing part, 60 ... Elastic material.

Claims (1)

[Scope of utility model registration request] 1. A lining material formed on an inner peripheral surface of a conduit is extended to the outside of the conduit through a hole formed in the conduit to form an electrode seal portion, and the electrode seal portion has a center of the conduit. Electromagnetic flow having a measurement electrode inserted into an insertion hole bored in the axial direction and pressed by a sprinkle through a cap having a signal line insertion hole in the center so that the lower surface of the flange portion abuts the electrode seal portion. In the electrode part structure of the meter, the measurement electrode is coated with a thermoplastic resin, leaving a contact part between the liquid contact part at the inner end and the signal line at the outer end,
The insulating cap having a first pressing portion that abuts the flange portion and a second pressing portion that is integrated with the first pressing portion and has an opening through which the signal line penetrates is formed in the center by the spring. And the second pressing portion is pressed by an elastic body having a through hole in the central portion, and the signal wire of the insulating coating connected to the outer end is pulled out through the through hole to measure the cap. An electrode part structure of an electromagnetic flow meter, characterized in that the signal line and the outer end part of the measuring electrode are simultaneously sealed by being pressed to the electrode side.