JP2763604B2 - Electromagnetic flow meter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic flowmeter suitable for use in a vertical pipe for water supply.

(Prior art)

As the water meter, a so-called connected impeller type water meter having an outer shape as shown in Fig. 7 is widely used. Recently, there has been a demand for disposing a water meter in a pipe shaft for installation in an apartment house. The disadvantage is that it is difficult to install the water meter 1 in a narrow pipe shaft because the length L of the water meter 1 is long. Therefore, as shown in FIG. 8, an axial flow impeller type water meter 2 for vertical piping, in which the width W of a water meter attached to a water supply pipe is reduced, has been developed and used. As shown in FIG. 9, the axial-flow impeller water meter 2 has a vertical passage 3 having an upper end opened in the center, and water passing through the passage 3 from below to above. A U-turn path, that is, a substantially cylindrical path 5 formed around the outer periphery of the pipe part 4 forming the path 3, a case 6 forming the path 5, and the path 3 This is a so-called mechanical water meter having a reduced gear train interlocked with the rotating shaft of the impeller 7 and a display unit driven by the gear train.

[Problems to be solved by the present invention]

Since the axial width impeller type water meter shown in FIG. 9 of the prior art can be reduced in width W, it is convenient to install it in a small space in a pipe shaft as described with reference to FIG.問題 Because it is a mechanical type with an impeller and a gear train, it has the drawbacks of a mechanical type with a rangeability of about 1: 100, a narrow measuring range, short durability, and low large flow resistance. A point was left.

Accordingly, the present invention proposes to propose a novel structure of a flow meter having a small width W suitable for vertical piping as in the prior art, using an electromagnetic flow meter which does not have any drawbacks inherent in the mechanical water meter. Aim.

[Means for solving the problem]

In order to achieve the above object, in the electromagnetic flowmeter of the present invention, a pipe (4) having an opening at the upper end and having a passage (3) through which water passes upward from below, and the pipe (4). And a case (6) having a substantially annular passageway (5) in which water U-turned around the upper end of the pipe portion (4) flows around the outer periphery of the upper portion of the upper pipe portion (4). An annular lower magnetic pole (7) provided on the outer periphery, and an annular upper magnetic pole (8) disposed on the upper surface of the case (6) so as to face the lower magnetic pole (7).
An iron core (9) arranged between the magnetic poles (7) and (8) to magnetically connect these magnetic poles, and an exciting coil (10) wound around the iron core (9); Two electrodes (11) and (12) are provided close to the inner surface of the case (6) where water flows around the upper part of the tube (4).

Further, in the electromagnetic flowmeter according to the second aspect, a pipe portion (4) having an upper end opened at the center and having a passage (3) through which water passes upward from below, and a pipe at an outer periphery of the pipe portion (4). In a water meter having a case (6) formed with a substantially annular passage (5) through which U-turned water flows around the upper end of the section (4), a yoke (20) surrounding the outer periphery of the pipe section (4) And two magnetic poles (21) and (22) on the outer periphery of the case (6) and opposed to the yoke (20);
Iron cores (23), (24) with one end magnetically connected to (22)
And the exciting coil (25) wound around the iron cores (23) and (24),
(26), an annular yoke (27) for magnetically connecting the other ends of these iron cores, and the magnetic poles (21),
(22) and two electrodes (28) and (29) arranged at a right angle.

[Action]

When an exciting current flows through the exciting coil (6) and the iron core (9) is magnetized, a parallel vertical magnetic field is generated between the lower magnetic pole (7) and the upper magnetic pole (8), and water is generated in the pipe ( 4) A circular induced voltage is generated in a portion flowing around the upper end of FIG. This voltage is taken out by the electrodes (11) and (12). If water flows in the opposite direction, the induced voltage will also be in the opposite direction.

According to the second aspect of the present invention, when an exciting current is applied to the exciting coils (25) and (26), the iron cores (23) and (24) are magnetized, and the gap between the magnetic poles (21) and (22) and the yoke (20) is increased. A radial magnetic field is generated in the annular passage (5), and a circumferential induced voltage is generated in the fluid flowing therethrough. This induced voltage can be extracted from the electrodes (28) and (29).

〔Example〕

In the first embodiment shown in FIGS. 1 to 3, reference numeral 4 denotes a pipe portion having a passage 3 whose upper end is open, 5 denotes an annular passage through which U-turned water flows around the upper end of the pipe portion 4, 6 Denotes a case having the passage, 7 denotes an annular lower magnetic pole provided on the outer periphery of the upper end of the tube portion 4, 8 denotes an upper magnetic pole provided on the upper surface of the case 6, and is arranged to face the lower magnetic pole 7, and both magnetic poles have parallel plate surfaces. It has become. An iron core 9 around which an exciting coil 10 is wound is inserted between the magnetic poles 7 and 8 (FIG. 3). Electrodes 11 and 12 are provided near a portion 6 a of the wall surface of the case 6, a portion of which protrudes into the annular passage 5.

From the passage 3, the water flowing around the upper end of the tube portion 4 radially as indicated by the arrow and the magnetic flux passing at right angles to the paper surface, the circular induced voltage indicated by the arrow in FIG. It is taken out and input to the amplifier 13 as shown in FIG. In FIG. 1, 14 is an electronic circuit, and 15 is a display.

In the second embodiment shown in FIGS. 5 and 6, reference numeral 20 denotes a cylindrical yoke surrounding the tube portion 4, reference numerals 21 and 22 denote magnetic poles arranged outside the case 6, and reference numerals 23 and 24 denote excitation coils 25, respectively. , 26 and a yoke, and an induced voltage is extracted by electrodes 28 and 29.

〔The invention's effect〕

According to the present invention, it is possible to widen the measurement range by setting the rangeability, which is an inherent advantage of the electromagnetic flowmeter, to a large value of about 1: 1000, and since there is no movable part, the durability is long, and the large flow resistance is large. Since the width W at the time of mounting can be reduced as in the conventional mechanical type without losing the characteristics, it can be practically used as a new high-performance meter replacing the mechanical type.

[Brief description of the drawings]

1 to 4 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view, FIG. 2 is a II-II sectional view of FIG. 1, FIG. FIG. 4 is a diagram for explaining the induced voltage. Fifth
FIG. 6 and FIG. 6 show the second embodiment. FIG. 5 is a longitudinal sectional view, and FIG. 6 is a sectional view taken along line IV-IV of FIG. FIG. 7 is an external view of a water meter showing an example of the prior art, FIG. 8 is a water supply piping diagram, and FIG. 9 is a longitudinal sectional view of a main part showing another example of the prior art. 3 ... passage, 4 ... tube part, 5 ... annular passage, 6 ... case, 7 ... lower magnetic pole, 8 ... upper magnetic pole, 9 ... iron core,
10 Excitation coil, 11, 12 Electrode, 20 Yoke, 21,
22… magnetic pole, 23,24… iron core, 25,26… excitation coil, 27
…… Yoke, 28,29 …… Electrode

Claims (2)

(57) [Claims] 1. A pipe (4) having a passage (3) through which water is allowed to pass upward from below and an upper end thereof being opened, and the upper end of the pipe (4) is provided on the outer periphery of the pipe (4). In a water meter having a case (6) formed with a substantially annular passage (5) through which U-turned water flows, an annular lower magnetic pole (7) provided on an outer periphery of an upper end of an upper pipe (4) is provided. An annular upper magnetic pole (8) disposed opposite to the lower magnetic pole (7) on the upper surface of the case (6), and these magnetic poles are magnetically connected between the magnetic poles (7) and (8). (9), an exciting coil (10) wound around the iron core (9), and the tube (4)
An electromagnetic flowmeter provided with two electrodes (11) and (12) disposed close to the inner surface of a case (6) where water flows around the upper part of the case. 2. A pipe part (4) having a passage (3) through which water is allowed to pass upward from below, and an upper end of the pipe part (4) is provided on the outer periphery of the pipe part (4). In a water meter having a case (6) formed with a substantially annular passage (5) through which U-turned water flows, a yoke (20) surrounding the outer periphery of a pipe (4) and a case (6) are formed. Two magnetic poles (21) on the outer periphery and opposed to the yoke (20),
(22), iron cores (23) and (24) each having one end magnetically connected to these magnetic poles (21) and (22), and iron cores (23) and (2).
Excitation coils (25) and (26) wound around 4) and an annular yoke (27) for magnetically connecting the other ends of these iron cores,
An electromagnetic flowmeter having a case (6) provided with two electrodes (28) and (29) arranged at right angles to the magnetic poles (21) and (22).