JPH02193018A - Assembling of electromagnetic flowmeter - Google Patents

Abstract

PURPOSE:To achieve a simplification of working and a reduction in production costs by interposing an elastic sheet between a receptacle and a plug before the filling with a resin to enable the blocking of the resin from flowing into a contact between both connectors. CONSTITUTION:A measuring tube 3 which has an electrode, an exciting coil 5, a receptacle 21 and the like mounted on the outer circumferential surface thereof beforehand is inserted securely into a case 1. Then, a plug 23 is inserted from a diametrical direction of the measuring tube 3 together with a thread bar 26 and is mounted on the receptacle 21. Here, an elastic sheet 25 is interposed between the receptacle 21 and the plug 23. Thereafter, a resin 6 is filled between the case 1 and the measuring tube 3 surrounding the receptacle 21, the plug 23 and the like. Thus, a clearance as formed between the receptacle 21 and the plug 23 by the sheet 25 is closed thereby enabling the blocking of the resin 6 from flowing into a connector contact section accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of assembling an electromagnetic flowmeter having a function of preventing water intrusion or dew condensation.

[Conventional technology]

In general, electromagnetic flowmeters are known to convert the flow rate of a conductive fluid flowing in a measurement tube into an electrical signal using Faraday's electromagnetic induction phenomenon to measure the flow rate. It is composed of To explain this based on the same figure, in the same figure, the case indicated by the symbol l is a case for an electromagnetic flowmeter, and the whole is formed of a cylindrical body, and the outer peripheral surface has a cylindrical shape that opens inside and outside the case. Mounting part 2
are integrated. Reference numeral 3 denotes a measuring tube having a pair of electrodes (not shown) each facing each other in the central part in the axial direction, and is attached to the inner circumferential surface of the case 1, and a terminal board for connecting lead wires is provided on the outer circumferential surface. 4 is installed. 5
are a pair of excitation coils (only one of which is shown) that forms a magnetic field in a direction perpendicular to the flow direction of the fluid to be measured, which are provided on the outer peripheral surface of the measurement tube 3 and connected to the terminal board 4.

6 is a resin such as epoxy or urethane that surrounds the electromagnetic flowmeter parts and is filled between the case 1 and the measurement tube 3 to prevent water from entering the case and dew condensation from occurring within the case. configured to prevent 7 is a lead wire connecting the terminal board 4 and a terminal box or a converter.

By the way, in order to assemble the electromagnetic flowmeter configured as described above, the measuring tube 3 with the electrodes (not shown), the excitation coil 5 (only one shown) and the terminal block 4 attached thereto is inserted and fixed in the case 1 in advance. Next, the case 1 and the measuring tube 3 are placed between the measuring tube 3 and the case 1 so as to surround each electromagnetic flow needle component.
This is done by filling the space between them with resin 6.

[Problem to be solved by the invention]

However, in the assembly method of this type of electromagnetic flow needle,
When inserting and fixing the measuring tube 3 into the case 1, each lead wire (
Since the electrode lead wire, coil lead wire, and ground wire (7) are taken out from inside the case 1 through the mounting part 2, the work to take out the lead wires is done in a small space, making it difficult to assemble the electromagnetic flow needle. The problem was that it made it difficult.

Therefore, in the conventional electromagnetic flow needle assembly method, the third
As shown in the figure, a receptacle 12 as a first connector connected to an electrode 11 and an excitation coil 5 and a plug 13 as a second connector attached to the receptacle 12 are also used.

That is, the assembly of this type of electromagnetic flowmeter consists of the electrode 11
The measurement tube 3, which has a receptacle 12 connected to the excitation coil 5 on its outer circumferential surface, is inserted and fixed into the cylindrical case 1 for an electromagnetic flowmeter, and then a plug 13 is inserted into the receptacle 12 from the radial direction of the measurement tube 3. This is done by filling the space between the cylindrical case 1 and the measuring tube 3 with resin 6 so as to surround the receptacle 12, plug 13, etc.

However, in the assembly method of this type of electromagnetic flowmeter,
A clearance was formed between the receptacle 12 and the plug 13, so that the resin 6 passed through the clearance and flowed into the contact point between the receptacle 12 and the plug 13. As a result, electrolytic corrosion caused by leakage current,
Considering the difference in linear expansion coefficient between the resin 6, the receptacle 12, and the plug 13, and the shrinkage and expansion of the resin 6 during curing, it becomes necessary to use an expensive material as the material for the resin 6, which increases manufacturing costs. there were. In this case, it is conceivable to apply oil to the contact between the receptacle 12 and the plug 13 to prevent the resin 6 from flowing into the contact, but it is not possible to actually prevent the resin 6 from flowing into the contact. Ta.

The present invention has been made in view of the above circumstances, and eliminates the need to pass the lead wire through the case to take out the lead wire or select the resin material, thereby simplifying the assembly work and reducing costs. The present invention provides a method for assembling an electromagnetic flowmeter that can be performed.

[Means to solve the problem]

A method for assembling an electromagnetic flowmeter according to the present invention is to insert and fix a measurement tube having a first connector connected to an electrode and an excitation coil on its outer peripheral surface into a cylindrical case for an electromagnetic flowmeter, and then to perform the measurement. After attaching the second connector to the first connector from the radial direction of the tube, resin is filled between the cylindrical case and the measurement tube so as to cover the second connector and the first connector. A method of assembling an electromagnetic flowmeter comprising:
An elastic sheet is interposed between both connectors before filling with this resin.

[For production]

In the present invention, the clearance formed between the first connector and the second connector is closed by the elastic sheet, and it is possible to reliably prevent resin from flowing into the connector contact portion.

〔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 an electromagnetic flowmeter according to an assembly method according to the present invention. In this figure, the same members as in FIG. In the same figure, a receptacle designated by the reference numeral 21 is a first connector, and is fixed to a portion on the outer circumferential surface of the measurement tube 3 and corresponding to the attachment portion 2. A lead wire (not shown) of the electrode (not shown) and a coil lead wire (not shown) of the excitation coil 5 are connected to the terminal 22 of this receptacle 21 . A plug 23 serves as a second connector, and a terminal 24 connects to the terminal 22.
and is attached to the receptacle 21. Reference numeral 25 denotes an elastic sheet made of, for example, silicone rubber, which is interposed between the receptacle 21 and the plug 23, and closes the clearance between these two connectors 21 and 23. Note that 26 is a threaded rod for strengthening the connection between the receptacle 21 and the plug 23.

Next, a method for assembling the electromagnetic flowmeter according to the present invention will be explained.

First, the measurement tube 3, on which electromagnetic flowmeter parts such as electrodes (not shown), the excitation coil 5, and the receptacle 21 are attached in advance on the outer circumferential surface, is inserted and fixed into the case 1. Next, the plug 2 is inserted together with the threaded rod 26 from the radial direction of the measuring tube 3.
3, and attach the plug 23 to the receptacle 21. At this time, an elastic sheet 25 is interposed between the receptacle 21 and the plug 23. After that, receptacle 21. A resin 6 is filled between the case 1 and the measuring tube 3 so as to surround the electromagnetic flowmeter components such as the plug 23.

In this way, an electromagnetic flowmeter can be assembled.

Therefore, in the present invention, the clearance formed between the receptacle 21 and the plug 23 is closed by the elastic sheet 25, and it is possible to reliably prevent the resin 6 from flowing into the connector contact portion. There is no need to take out the lead '4IA7 by passing it through the mounting part 2 from inside the case 1 or to select the material for the resin 6.

Note that, of course, the material of the elastic sheet 25 in the present invention is not limited to the above-mentioned embodiments.

〔Effect of the invention〕

As explained above, according to the present invention, a measurement tube having a first connector connected to an electrode and an excitation coil on its outer peripheral surface is inserted and fixed into a cylindrical case for an electromagnetic flowmeter, and then the measurement tube is After the second connector is attached to the first connector from the radial direction, a resin is filled between the cylindrical case and the measurement tube so as to surround the second connector and the first connector. A method for assembling a flowmeter, in which an elastic sheet is interposed between both connectors before filling with the resin, so that the clearance formed between the first connector and the second connector is closed by the elastic sheet. Therefore, it is possible to reliably prevent resin from flowing into both connector contact portions. Therefore, it is not necessary to take out the lead wire by passing it through the cylindrical case or to select a resin material, so that the electromagnetic flowmeter assembly work can be simplified and the manufacturing cost can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an electromagnetic flowmeter according to an assembly method according to the present invention, and FIGS. 2 and 3 are sectional views showing an electromagnetic flowmeter using a conventional assembly method. l...Case, 2...Mounting part, 3...Measuring tube, 5...Exciting coil, 6...Resin, 21...
... Receptacle, 22 ... Terminal, 23 ... Plug, 24 ... Terminal, 25 ... Elastic sheet.

Claims (1)

[Claims] A measuring tube having a first connector connected to an electrode and an excitation coil on its outer peripheral surface is inserted and fixed into a cylindrical case for an electromagnetic flowmeter, and then a second connector is inserted from the radial direction of the measuring tube. The method of assembling an electromagnetic flowmeter comprises filling a space between the cylindrical case and the measurement tube with resin so as to surround the second connector and the first connector after the flowmeter is attached to the first connector. A method for assembling an electromagnetic flowmeter, characterized in that an elastic sheet is interposed between the two connectors before filling with the resin.