JPH05107091A - Electromagnetic flow meter - Google Patents

Abstract

(57) [Abstract] [Purpose] A shield braided wire is not required, and the signal lead wire of the electrode and the lead wire of the exciting coil can be wired at the same time, which improves assembly workability and work safety. [Structure] A tape electric wire 21 made of a flexible printed circuit board in which a signal line pattern and a shielded wire pattern are laminated is provided on the outer circumference of a measuring tube 1, and the exciting wire 3A, 3B and electrodes 4A, 4B are provided in an electric device by this tape electric wire. Connect to the wiring connection unit 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic flow meter for measuring the flow rate of a conductive fluid flowing in a measuring pipe.

[0002]

2. Description of the Related Art Flow in a measuring pipe is made using the principle of electromagnetic induction.
Electromagnetic flowmeter for measuring the flow rate of conductive fluid
28411, etc.) is a signal generated in a fluid.
The electromotive force is applied to the electrodes provided in the direction orthogonal to this flow.
Therefore, I take it out. 9 to 11 are this
A perspective view, a cross-sectional view, and a diagram showing a conventional example of such an electromagnetic flowmeter.
In the plan view of the part, 1 has flanges 1a and 1b integrally on both ends.
The non-magnetic material such as stainless steel
The measuring tubes 3A and 3B made of a physical body face the outer circumference between the measurements.
The magnetic field is formed at right angles to the flow direction of the fluid to be measured 2.
The pair of saddle type exciting coils 4A and 4B are
The central part of the measuring tube 1 so as to be orthogonal to both the flow directions of the fluid.
And a pair of electric wires whose inner end faces inside the pipe 5
The poles, 6A and 6B are also provided on the outer circumference of the measuring tube 1.
Inner core and outer core, 7 is a converter, 8 is electric
Lined on the inner wall of the measuring tube 1 to provide static insulation and corrosion resistance
Lining made of insulating material such as fluorocarbon resin
Materials 10A, 10B are signal lead wires of electrodes 4A, 4B,
11 is a receptacle fixed to the outer core 6B (see FIG.
11 is omitted.), 12 are leads of the exciting coils 3A and 3B.
In line, these form the electromagnetic flowmeter. signal
The lead wires 10A and 10B are the shield braided wire 1 respectively.
Shielded by 3A and 13B on the outer circumference of the measuring tube 1.
Approximately 1/4 round traveled and converted via receptacle 11
Connected to the container 7. Therefore, the signal lead wire 10
In the middle of A and 10B, crimp to the terminal of the receptacle 11 or
Are soldered together. Similarly, the exciting coils 3A, 3B
The lead wire 12 is also shielded by the shield braided wire.
By crimping or soldering to the terminals of the receptacle 11.
Is connected.

In such a structure, the exciting coil 3
When A and 3B are energized to excite them, a magnetic field is generated across the conductive fluid in the measuring tube 1 and orthogonal to its flow. Then, due to the electromagnetic induction phenomenon, an electromotive force proportional to the flow velocity is generated in the fluid in a direction perpendicular to the direction of the magnetic field and the direction of the flow. The electromotive force is taken out by the electrodes 4A, 4B, amplified, recorded, or an indicator meter is provided. To measure the flow rate and average flow velocity of the fluid, and perform constant value control of the flow rate.

[0004]

However, in the above-mentioned conventional electromagnetic flowmeter, the signal lead wire 10A,
10B and the lead wires 12 of the exciting coils 3A and 3B are crimped or soldered to the terminals of the receptacle 11, the shield braided wires 13A and 1A that shield these lead wires
There is also a problem in safety workability because the work for unwinding the stitches of 3B is required, the work is troublesome, time consuming, and the assembling workability is poor, and the stitches are pierced by fingers.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to eliminate the need for a shield braided wire, and to lead the signal lead wire of the electrode and the lead wire of the exciting coil. An object of the present invention is to provide an electromagnetic flow meter which can be wired simultaneously with a wire and which improves the workability of assembly and the safety of work.

[0006]

The present invention has been made to achieve the above object, and the invention according to claim 1 is
A pair of exciting coils provided on the outer circumference of the measurement pipe and forming a magnetic field perpendicular to the flow direction of the fluid to be measured, and arranged to face the measurement pipe so as to be orthogonal to both the magnetic field and the flow direction of the fluid. In an electromagnetic flowmeter having a pair of electrodes, the pair of exciting coils and the pair of electrodes are connected to a wiring connecting portion in an electric device by an integrally formed tape electric wire. According to a second aspect of the present invention, a pair of exciting coils which are provided on the outer circumference of the measuring pipe and which form a magnetic field perpendicular to the flow direction of the fluid to be measured, and are orthogonal to both the magnetic field and the fluid flow direction. As described above, in the electromagnetic flowmeter having a pair of electrodes arranged to face the measuring tube, the pair of electrodes and a wiring connection portion in an electric device are formed in a multilayer structure in which a signal line pattern is shielded by a shield line pattern. Equipped with a plurality of electrode extraction parts in the electrode branch part,
In addition, a planned cutting portion is provided between the electrode extraction portions, and the shield wire pattern in the planned cutting portion is connected by a tape electric wire having a shape in which the vicinity of the signal line pattern is removed.

[0007]

In the present invention, the tape electric wire has the signal line pattern for the electrode shielded by the shield wire pattern and the wiring pattern for the exciting coil, and connects the exciting coil, the electrode and the wiring connecting portion in the electric device. .. Further, the tape electric wire has a plurality of electrode lead-out portions at the electrode branching portion, so that the tape electric wire can be used for measuring tubes having different diameters. The shield line pattern of the portion to be cut provided between the electrode lead-out portions has a shape avoiding the signal line pattern and is not shielded, and does not make conductive contact with the signal line pattern at the time of cutting.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. 1 is a schematic perspective view of an electromagnetic flowmeter according to the present invention, FIG. 2 is a perspective view of an exciting coil and a tape wire, and FIG.
Is a development view of the tape electric wire, and FIG. 4 is a sectional view taken along line IV-IV of FIG. In the figure, the same components as those in FIGS. 9 to 11 are designated by the same reference numerals, and the description thereof will be omitted. In these drawings, the present embodiment shows an exciting coil 3A,
3B and the electrodes 4A, 4B and the wiring connection portion 20 in the electric device (converter) are connected by a tape electric wire 21 formed integrally.

The tape electric wire 21 is generally called a flexible printed cable or a flexible printed board. As shown in FIGS. 3 and 4, the wiring pattern 24A of the exciting coils 3A and 3B and the signal lines of the electrodes 4A and 4B are provided on the front and back surfaces. Base film 22 on which pattern 24B is formed
And cover films 25 and 26 covering the front and back surfaces of the base film 22, and shield line patterns 27 and 2 formed on the front and back surfaces of the cover films 25 and 26, respectively.
8 and the overlay films 29 and 30 covering the shield line patterns 27 and 28 are formed into a 7-layer structure.
A backing material 31 is attached to the surface of one overlay film 29. Base film 22, cover films 25, 26 and overlay film 29,
The wiring pattern 30 is made of a polyimide film, a polyester film or the like having a thickness of about 0.025 mm.
4A and the signal line pattern 24B have a thickness of 0.035 m.
The rolled copper foil of about m and the backing material 31 are glass cloth and epoxy resin laminated plate of about 0.5 mm. Therefore,
The thickness of the tape electric wire 21 is at most about 0.6 mm.

The tape electric wire 21 is formed in a shape as shown in FIG. 3 in consideration of efficiency of material removal. That is, the tape electric wire 21 has a horizontally E-shaped coil pattern portion 21A in which a wiring pattern 24A for the exciting coils 3A and 3B is formed, and a horizontally U-shaped wiring between the wiring connection portion 20 in the electric device. A device pattern portion 21B in which a pattern 24A and a signal line pattern 24B are formed, and two electrode branch portions 21C and 21D in which a signal line pattern 24B is formed in parallel with the coil pattern portion 21A and the device pattern portion 21B, respectively. And the connecting portions 32 are electrically connected and fixed to the outer core 6B. The coil pattern portion 21A, the device pattern portion 21B, and the electrode branch portions 21C and 21D have appropriate lengths and are attached to the outer circumference of the measuring tube 1.

Of the three branched arm portions 34a, 34b, 34c of the coil pattern portion 21A, the tip of the arm portion 34a is connected to the connecting portion 32, and the arm portion 34b is, for example, on the outer circumference of the measuring tube 1. The excitation coils 3A and 3B are attached in a clockwise direction, and one end of each of the excitation coils 3A and 3B is connected to the tip end portion 36 thereof. The remaining arm portion 34c is turned upside down in the opposite direction to the arm portion 34b and is counterclockwise attached to the outer circumference of the measuring tube 1, and the other ends of the exciting coils 3A and 3B are connected to the tip portion 37 thereof. It The exciting coils 3A and 3B are connected in series.

The device pattern portion 21B has two long arm portions 38a branched by being formed in a horizontally long U-shape.
38 b, and is bent vertically above the measuring tube 1 so that the tip portions 39, 40 of the arm portions 38 a, 38 b are connected and fixed to the wiring connection portion 20 in the electric device. Further, in order to reduce the influence of noise due to the 90 ° phase shift, the device pattern portion 21B is changed in the 90 ° direction so that the surface direction is orthogonal to the axis of the measuring tube 1.

The electrode branch portions 21C and 21D are the measuring tubes 1
Is attached to the outer circumference of the electrode in a clockwise or counterclockwise direction, and its tip is connected to each of the electrodes 4A, 4B. A plurality of electrode lead-out portions 42 are formed in the longitudinal direction of the tip ends of the electrode branch portions 21C and 21D. This electrode extraction part 42
The tape electric wire 21 is formed as a common component by being formed corresponding to the electrodes of various measuring tubes 1 having different diameters. When the tape electric wire 21 is incorporated in a measuring tube having a small diameter, it has a diameter larger than that of the electrode mounting portion. Since the electrode extraction portion on the side is unnecessary, it is entirely cut and removed. Therefore, a portion to be cut 43 is defined between the electrode extraction portions 42.

The structure of the electrode lead-out portion 42 and the planned cutting portion 43 will be described in more detail with reference to FIGS. 5 to 7. The electrode lead-out portion 42 is for mounting screws which penetrate the front and back surfaces of the electrode branch portion 21C (21D). Each hole 45 is formed. Further, in the electrode lead-out portion 42a for the maximum diameter located on the outermost side, the overlay film 29, the shield wire pattern 2
7 (shaded portion in FIG. 5) and a hole 46, which is sufficiently larger than the outer diameter of the head of the set screw inserted through the screw mounting hole 45 in the cover film 25, is formed coaxially with the screw mounting hole 45. This is because the signal line pattern 24B and the shield line pattern 27 are formed when the electrode lead-out portion 42a is connected and fixed to the electrode.
This is to prevent and from being electrically connected via the set screw. Furthermore, the lower shielded wire pattern 28
Also, a hole 47 which is sufficiently larger than the screw mounting hole 45 is formed coaxially therewith. On the other hand, in the other electrode lead-out portions 42, a tongue-shaped cover 50 that covers the shield wire pattern 27 and the holes 46 of the cover film 25 is formed on the overlay film 29, whereby the signal line pattern 24B and the shield. Line pattern 2
7 and 28 are protected from dust and moisture. This cover 5
0 is cut and removed when the electrode extraction portion 42 of the cover is connected to the electrode. The other structure is the same as that of the electrode lead-out portion 42a having the maximum diameter described above.

The planned cutting portion 43 provided between the electrode lead-out portions 42 has holes 52 and 53 (FIG. 7) larger than the width of the signal line pattern 24B in the shield line patterns 27 and 28. When the electrode branch portion 21C (21D) is cut along the line 54, the signal line pattern 24B
And the shield line patterns 27 and 28 are prevented from making conductive contact with each other.

The tape wire 21 has the above-mentioned shape,
It is needless to say that various modifications and changes are possible without being limited to the structure, and, for example, the electrode lead-out portion 42.
Instead of connecting and fixing to the electrode with a set screw, it is also possible to connect by soldering, pressure bonding, pressure contact, or the like.

Thus, in the electromagnetic flowmeter having such a structure, the exciting coil 3A by the tape electric wire 21,
3B and the wiring connection portion 20 in the electric device and the electrode 4A,
The connection work between 4B and the wiring connection portion 20 is simple and easy, and the work of unwinding the stitches of the shield braided wire, which has been conventionally required, is unnecessary, and therefore the fingers do not injure due to the stitches. It's safe. In addition, the tape electric wire 21 includes a signal wire pattern 24B and a shield wire pattern 2
The signal line pattern 2 has a structure in which 7, 28 are formed in multiple layers.
The shield of 4B is reliable, and it is not necessary to purposely shield the tape electric wire 21 itself. Furthermore, since the tape wire 21 has a plurality of electrode lead-out portions 42 formed in the electrode branch portions 21C and 21D, it can be commonly used for measuring tubes of various diameters.
Enables reduction in the number of parts.

FIG. 8 is a plan view showing another embodiment of the tape electric wire. This embodiment corresponds to the invention described in claim 2, and the coil pattern portion 21 in the above embodiment is used.
A is removed, and the tape electric wire 21 is configured by the device pattern 21B and the electrode branch portions 21C and 21D. The exciting coils 3A and 3B are connected by lead wires as in the conventional case. Even with such a configuration, the same effects as those of the above-described embodiment can be obtained for the electrodes 4A and 4B.

[0019]

As described above, according to the electromagnetic flowmeter of the present invention, since the flexible tape electric wire is used in place of the lead wire, the exciting coil is connected between the wiring connection portion in the electric device and the electrode. The wiring connection between the wiring connection part and the wiring connection part is simple and easy, there is no need to purposely shield the tape electric wire with the shield braided wire, and if the shield braided wire is not used, the work of unwinding the stitches is also unnecessary. It is possible to work safely without the risk of finger sticks. Further, since a plurality of electrode lead-out portions are formed at the electrode branch portion of the tape electric wire, the tape electric wire can be commonly used for measuring pipes of various diameters, and the number of parts can be reduced. Furthermore, the shield line pattern of the part to be cut provided between the electrode lead-out parts is formed so as not to overlap the signal line pattern, so there is no conductive connection at the time of disconnection, and the shield of the signal line pattern is reliable. Is.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an electromagnetic flow meter according to the present invention.

FIG. 2 is a perspective view of an exciting coil and a tape wire.

FIG. 3 is a development view of a tape electric wire.

4 is a sectional view taken along line IV-IV of FIG.

FIG. 5 is a plan view of an electrode branch portion.

6 is a sectional view taken along line VI-VI of FIG.

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a plan view showing another embodiment of the tape electric wire.

FIG. 9 is a schematic perspective view showing a conventional example of an electromagnetic flow meter.

FIG. 10 is a cross-sectional view of a main part.

FIG. 11 is a plan view of a main part.

[Explanation of symbols]

 1 Measuring Tube 3A, 3B Excitation Coil 4A, 4B Electrode 7 Converter 11 Receptacle 12 Lead Wire 21 Tape Wire 21C, 21D Electrode Branching Section 24A Coil Wiring Pattern 24B Signal Line Pattern 27, 28 Shielding Wire Pattern 42 Electrode Extracting Section 43 cutting section

Claims (2)

[Claims] 1. A pair of exciting coils which are provided on the outer circumference of a measuring tube and form a magnetic field perpendicular to the flow direction of a fluid to be measured,
In an electromagnetic flowmeter having a pair of electrodes arranged so as to face the measurement pipe so as to be orthogonal to both the magnetic field and the flow direction of the fluid, a wire connection in the electric device with the pair of exciting coils and the pair of electrodes. An electromagnetic flowmeter characterized in that the part and the part are connected by an integrally formed tape electric wire. 2. A pair of exciting coils which are provided on the outer circumference of the measuring pipe and which form a magnetic field perpendicular to the flow direction of the fluid to be measured,
In an electromagnetic flowmeter having a pair of electrodes arranged to face the measurement tube so as to be orthogonal to both the magnetic field and the flow direction of the fluid, a signal is output from the pair of electrodes and a wiring connection portion in an electric device. The line pattern is formed in a multilayer structure shielded by a shield line pattern, and a plurality of electrode lead-out portions are provided in the electrode branching portion, and a planned cut portion is provided between the electrode lead-out portions. An electromagnetic flowmeter characterized in that it is connected with a tape electric wire having a shape in which the vicinity of the signal line pattern is removed.