JP6436718B2 - Electromagnetic water meter - Google Patents

Description

  The present invention relates to a water meter, and more particularly to an electromagnetic water meter.

2. Description of the Related Art Conventionally, there is known a vertical water meter that has an impeller and counts and displays an integrated flow rate of water that has passed through the water meter in conjunction with the rotation of the impeller (Patent Document 1).
In the vertical water meter described in Patent Document 1, tap water flowing from an inflow port opened in the horizontal direction in the meter case is guided to the lower room (introduction channel), and in the lower room. The direction of the tap water flow is changed to a substantially vertical direction, and then the tap water flows from the rectifier through the impeller to the water pipe through the outlet of the meter case.

  In such a water meter, the integrated flow rate of water that has passed through the water meter is counted and displayed in conjunction with the rotation of the impeller by a meter unit disposed at the top of the meter case.

JP2007-333686A

  Here, the mechanical water meter using the impeller described in Patent Document 1 uses a movable component such as an impeller, so that the impeller moves when foreign matter is mixed into the impeller. As a result, the flow rate of tap water may not be measured. In addition, if a large amount of tap water flows into a water meter that uses an impeller, the impeller may be similarly damaged, making it impossible to measure the flow rate of tap water.

  In view of such circumstances, a so-called electromagnetic water meter that uses a pair of detection electrodes without using an impeller and electromagnetically integrates the flow rate of tap water has become widespread. In such an electromagnetic water meter, a pair of detection electrodes are arranged at opposing positions on the inner wall of a straight tubular measuring tube built in the meter case, and a magnetic field is formed in the measuring tube via an electromagnet, thereby conducting The integrated flow rate of tap water is detected by detecting an electromotive force generated when the natural tap water passes through the magnetic field formed in the measurement pipe at right angles through the detection electrode.

  By the way, the meter case used for the water meter is formed relatively robustly and can sufficiently withstand long-term use, and the meter case of the mechanical water meter using the impeller described in Patent Document 1 above. Is being considered for diversion to the meter case of an electromagnetic water meter.

  However, in the meter case used for the vertical water meter described in Patent Document 1, as described above, the tap water that has flowed in from the inflow port opened in the horizontal direction in the meter case is the lower room (introduction channel). ) And the direction of tap water flow is changed to a substantially vertical direction in the lower room, and then tap water flows from the rectifier through the impeller to the water pipe from the outlet of the meter case.

  As described above, in the meter case in which the direction of tap water flow is changed, the flow rate deviation (uneven flow) occurs on the inner wall of the measurement pipe where the flow rate is measured due to the change in the water flow direction. . Such drift tends to be distributed on the inner wall of the measuring pipe depending on the inflow direction of the tap water. To accurately measure the flow rate of tap water flowing inside the measuring pipe in an electromagnetic water meter, the measuring pipe It is necessary to arrange a pair of detection electrodes at a position where a large drift can be detected on the inner side wall.

  The present invention has been made to solve the above-mentioned conventional problems, and the water flow of tap water in the case body is based on using the case body of a vertical water meter using an impeller as an electromagnetic water meter. Even when the direction changes, a pair of detection electrodes are installed at positions that can reliably detect the maximum value of the drift generated on the inner wall of the measurement tube and its peripheral value, thereby accurately detecting the flow rate of tap water. An object of the present invention is to provide an electromagnetic water meter that can be used.

In order to achieve the above object, an electromagnetic water meter according to claim 1 has an inlet into which tap water is introduced and an outlet from which tap water is discharged, and tap water is provided between the inlet and the outlet. A case main body in which the water flow direction is changed, a measurement pipe disposed in a portion where the water flow direction of the tap water is changed in the case main body, and a pair of detections that are fixed to the measurement pipe and detect a flow rate of the tap water A converter case for calculating a flow rate of tap water based on a signal indicating a flow rate of tap water detected by the electrode and the pair of detection electrodes, and a converter case disposed on the downstream side of the measurement tube; A base and a plurality of feet, and the base is fixed to the bottom of the converter case, and the end of each foot is fixed to the downstream end of the measurement tube, whereby the bottom of the converter case and the measurement tube Converter case while forming a gap with the downstream end of A bracket for connecting to the measurement tube, and there are three feet of the bracket, and these three feet are evenly arranged on a circumference centering on the central axis of the measurement tube. The foot represents the direction of tap water flowing into the inlet and assumes a line passing through the central axis of the measuring pipe, and the inlet side of the central axis of the measuring pipe on the line It is characterized by being arranged in .

  The electromagnetic water meter according to claim 2 is the electromagnetic water meter according to claim 1, wherein the pair of detection electrodes are arranged inside the measurement tube where a deviation in flow velocity occurs due to a change in the direction of water flow in the measurement tube. It is arranged to face each other within a predetermined range of the wall.

  The electromagnetic water meter according to claim 3 is the electromagnetic water meter according to claim 1 or 2, wherein the predetermined range represents a water flow direction flowing into the inflow port and a center of the measuring pipe. Assuming a line segment passing through the axis, the line segment is defined by the range of the locus drawn on the inner wall of the measurement tube by the line segment when the line segment is rotated around the central axis. Is rotated around the central axis within a range of ± 10 degrees or less, the line segment corresponds to the range of the locus drawn on the inner wall of the measuring tube.

Electromagnetic water meter according to claim 4, in any one of electromagnetic water meter of claims 1 to 3, provided at the bottom of the converter case tap water impinges through the pre-Symbol measuring tube, the measuring tube It comprises a rectifying unit that disperses the tap water from around the bottom of the converter case.

  The electromagnetic water meter according to claim 5 is the electromagnetic water meter according to any one of claims 1 to 4, wherein the electromagnetic water meter is formed inside the case main body and inserted into the upstream end portion of the measuring pipe. A hole and a holder member that holds the upstream end of the measurement tube and is fitted into the insertion hole and is formed in an annular shape, and a curved portion is formed at the upstream end of the holder member It is characterized by being.

  The electromagnetic water meter according to claim 6 is the electromagnetic water meter according to claim 5, wherein a stepped portion is formed around the insertion hole, and the holder member is locked to the stepped portion. A portion is formed.

An electromagnetic water meter according to a seventh aspect of the present invention is the electromagnetic water meter according to any one of the fourth to sixth aspects, wherein the measurement tube is accommodated while maintaining a gap with the outer peripheral surface of the measurement tube. A wiring that penetrates the case and the bottom of the converter case and is arranged in a gap between the measurement tube and the measurement tube case and electrically connects each detection electrode and the converter housed in the converter case is inserted. The waterproof pipe is a water flow of tap water that flows into the inlet through a gap formed between the bottom of the converter case and the downstream end of the measurement pipe. A line segment that represents the direction and passes through the central axis of the measurement tube is assumed, and the line segment is arranged on the inlet side with respect to the central axis of the measurement tube on the line segment .

  In the electromagnetic water meter according to claim 1, the measuring pipe is disposed in a portion where the water flow direction of the tap water changes in the case body where the water flow direction of the tap water is changed between the inlet and the outlet, Since a pair of detection electrodes for detecting the flow rate of tap water is fixed to the measurement pipe, the case body of the vertical impeller water meter can be diverted to an electromagnetic water meter, and the cost of the water meter can be significantly reduced. .

  In the electromagnetic water meter according to claim 2, the pair of detection electrodes for detecting the flow rate of tap water is provided within a predetermined range of the inner wall of the measurement tube in which a deviation in flow rate occurs due to a change in the direction of water flow in the measurement tube. Because they are placed facing each other, even if there is a bias in the flow rate of tap water in the measuring pipe, the peak of the flow rate of tap water can be reliably detected, and the flow rate of tap water must be measured with high measurement accuracy. Can do.

  In the electromagnetic water meter according to claim 3, the predetermined range on the inner wall of the measurement pipe in which the pair of detection electrodes is arranged represents the direction of tap water flowing into the inlet and passes through the central axis of the measurement pipe. Assuming a line segment, when the line segment is rotated around the central axis, it is defined by the range of the locus drawn on the inner wall of the measurement tube by the line segment, and the range of the locus is defined around the central axis. Since the line segment corresponds to the range of the locus drawn on the inner wall of the measuring tube when rotated within a range of ± 10 degrees or less, as long as the center portion of each detection electrode is within the range of the locus, it is somewhat from the optimal position. Even in the case of deviation, the peak of the tap water flow velocity can be reliably detected, and the tap water flow rate can be measured with high measurement accuracy. Thus, since flexibility can be given to the arrangement position of each pair of detection electrodes on the inner wall in the measurement tube, each detection electrode can be easily arranged on the inner wall of the measurement tube.

  In the electromagnetic water meter according to claim 4, a converter case having a built-in converter for calculating the flow rate of tap water based on a signal indicating the flow rate of tap water detected by the pair of detection electrodes is provided downstream of the measurement tube. Since the rectifier that disperses the tap water from the measuring tube around the bottom of the converter case is provided at the bottom of the converter case that is placed on the side and that is struck by the tap water flowing through the measuring tube, it flows out of the measuring tube The tap water is dispersed around the bottom of the converter case by the rectifying unit, and stagnation of the tap water and turbulence and separation of the water flow are suppressed. Thereby, the pressure loss of a water flow can be reduced.

  The electromagnetic water meter according to claim 5 is formed in an annular shape that is formed inside the case body, is fitted into an insertion hole into which the upstream end of the measurement tube is inserted, and holds the upstream end of the measurement tube. Since the holder member is formed and a curved portion is formed at the upstream end of the holder member, tap water flowing in from the inlet of the case body is smoothly guided by the curved portion of the holder member, and thereby measured. Since the tap water stays at the upstream end of the pipe and the turbulence and separation of the water flow are suppressed, the pressure loss of the water flow can be reduced.

  In the electromagnetic water meter according to claim 6, a step portion is formed around the insertion hole formed inside the main body case, and a hook portion that is locked to the step portion is formed around the holder member. Therefore, tap water does not leak into the main body case from between the upstream end of the measurement tube and the insertion hole, and this ensures that the tap water flowing from the inflow port flows into the measurement tube. It becomes possible to measure the amount of water accurately.

In the electromagnetic water meter according to claim 1 , the base is fixed to the bottom of the converter case, and the end of each foot is fixed to the downstream end of the measurement tube to thereby fix the bottom of the converter case and the measurement tube. A bracket is provided to connect the converter case and the measurement pipe while forming a gap with the downstream end, and the foot of the bracket is positioned to reduce the water flow resistance flowing out of the measurement pipe Therefore, the foot portion of the bracket does not become the water flow resistance of the tap water flowing out from the measuring pipe, and thereby the water flow resistance can be reduced and the pressure loss of the water flow can be reduced.

In the electromagnetic water meter according to claim 7 , the measurement tube case that houses the measurement tube while maintaining a gap between the outer periphery of the measurement tube, the measurement tube and the measurement tube case while penetrating the bottom of the converter case And a waterproof pipe through which a wiring for electrically connecting each detection electrode and the converter housed in the converter case is inserted, and the waterproof pipe is provided at the bottom of the converter case and downstream of the measurement tube. Since the water flow resistance of the tap water flowing out from the measurement pipe is arranged in a gap formed between the side ends, the water resistance of the tap water flowing out of the measurement pipe is arranged at a position to reduce the water flow resistance from the measurement pipe. Thus, the water flow resistance can be reduced and the pressure loss of the water flow can be reduced.

It is a perspective view of the electromagnetic water meter which concerns on this embodiment. It is a schematic cross section of an electromagnetic water meter. It is AA sectional drawing in FIG. It is a disassembled perspective view of an electromagnetic water meter. It is explanatory drawing which shows the state which welded and joined the measurement pipe case while welding the lower waterproof pipe to the measurement pipe. It is explanatory drawing which shows the state which welded and joined the upper waterproof pipe and the converter ring to the converter case. It is explanatory drawing which shows the state which welded and joined the converter case to the base part of the connection bracket, and welded and joined the foot | leg part of the connection bracket to the measurement pipe case. It is explanatory drawing which shows the state which has arrange | positioned packing to the flange of a lower case. It is explanatory drawing which shows the state which inserted what welded and joined the converter case and the measurement tube case in the lower case. It is explanatory drawing which shows the state which assembled | attached the upper case on the flange of the lower case.

Hereinafter, an electromagnetic water meter according to the present invention will be described based on an embodiment of the present invention with reference to the drawings. First, the basic configuration of the electromagnetic water meter 1 according to the present embodiment will be described with reference to FIGS.
The electromagnetic water meter 1 has a vertical lower case 10, and a meter body 20 described later is inserted into the lower case 10. A flange 10A is formed on the upper portion of the lower case 10, and the upper case 11 is joined to the flange 10A and fastened via bolts 11A. A circular hole 11B is formed at the center of the upper case 11, and the circular hole 11B is provided above the converter 40A (see FIG. 2) of the conversion unit 40 constituting a part of the meter body 20. The display board 42 is exposed. The display panel 42 displays an accumulated flow rate of tap water.

  The lower case 10 is a case where a so-called vertical impeller water meter is used as a case of the electromagnetic water meter 1 of the present embodiment. As a result, in the lower case 10, FIG. As shown by the arrow at, the direction of tap water flow is changed. Under such circumstances, when diverting the lower case 10, in consideration of the difference in measurement method, the invention is devised so that it can be diverted to the electromagnetic water meter 1 as described below.

  As shown in FIG. 2, the electromagnetic water meter 1 is disposed in a water pipe, and the lower case 10 supplies tap water from the inlet 12 and the lower case 10 through which tap water flows into the lower case 10 from the water pipe. An outlet 13 is provided that flows out into the tube. A circular opening 14 is provided in the upper part of the lower case 10, and a flange 10 </ b> A extending in the horizontal direction is formed on the outer periphery of the opening 14.

  The lower case 10 is roughly divided into two rooms. The lower case 15 communicates with the inflow port 12 and communicates upward from the lower room 15 and the lower room 15 arranged on the lower side. The upper room 16 to which the tap water is sent is formed. The lower chamber 15 and the upper chamber 16 communicate with each other in the vertical direction through a circular insertion hole 17. Upstream end portions 31 </ b> D and 32 </ b> A (lower end portions in FIG. 2) of a measurement tube 31 and a measurement tube case 32, which will be described later, are inserted into the insertion hole 17, and upstream of the measurement tube 31 and the measurement tube case 32. A bottom holder 54 that holds the side end portions 31D and 32A is fitted. On the upper side of the insertion hole 17, a step portion 17A is formed.

  The bottom holder 54 includes a cylindrical main body portion, a bottom surface portion 54A in which a circular hole is opened, and a flange portion 54B extending in the horizontal direction from the periphery of the main body portion. The flange portion 54B is locked to the stepped portion 17A of the insertion hole 17 with the shelf leakage preventing packing 55 interposed therebetween. Further, a curved surface is formed on the bottom surface portion 54 </ b> A corresponding to the upstream end portion (lower end portion in FIG. 2) of the bottom holder 54. Further, the lower horizontal portion 31B of the measurement tube 31 is disposed on the bottom surface portion 54A of the bottom holder 54 with the measurement tube packing 56 interposed therebetween.

  The meter body 20 basically includes a measurement unit 30 and a conversion unit 40, and the measurement unit 30 and the conversion unit 40 are connected to each other via a connection bracket 53.

  The measurement unit 30 stores the measurement tube 31 while maintaining a gap S between the measurement tube 31 disposed in the lower case 10 at a portion where the water flow direction of the tap water changes and the outer peripheral surface of the measurement tube 31. A pair of detection electrodes 33 and 33 for detecting the flow velocity of tap water passing through the measurement pipe 31 and a pair of electromagnetic coils arranged in the gap S, which are arranged at opposing positions on the inner wall of the measurement pipe case 32 and the measurement pipe 31. 34 is provided.

  The measurement tube case 32 is formed in a cylindrical shape, and has a cylindrical portion 31 </ b> A having a smaller diameter than the measurement tube case 32. Moreover, the upper end part and lower end part of the measurement tube 31 have a horizontal part 31B bent in the horizontal direction outside the cylindrical part 31A. Further, the end of the horizontal portion 31B is joined to the measurement tube case 32.

  As shown in FIG. 3, the pair of detection electrodes 33 are arranged such that the connection portion 33 </ b> A penetrates the cylindrical portion 31 </ b> A of the measurement tube 31 and the detection portion 33 </ b> B is exposed from the inner wall of the measurement tube 31. The

  Here, as shown in FIG. 3, considering a range in which the pair of detection electrodes 33 can be arranged on the inner wall of the measurement tube 31, the range is introduced into the lower case 10 from the inlet 12 of the lower case 10. Assuming a line L passing through the central axis 31C of the measuring pipe 31 and representing the direction of tap water flow, and rotating the line L around the central axis 31C, the line L causes the inside of the measuring pipe 31 to It can be defined by the range of the trajectory drawn on the wall. Specifically, the range of the locus is drawn on the inner wall of the measurement tube 31 when the line segment L is rotated around the central axis 31C within a range of ± 10 degrees or less with respect to the line segment L. Corresponds to the range of the trajectory. The range of the locus is a range in which the detection center of the detection unit 33B in each detection electrode 33 can move.

  The pair of detection electrodes 33 are opposed to each other with the central axis 31C of the measurement tube 31 interposed therebetween, and are arranged on the inner wall of the measurement tube 31 so that the center of the detection portion 33B in the detection electrode 33 passes through the line segment L. The pair of electromagnetic coils 34 are opposed to each other with the central axis 31 </ b> C of the measurement tube 31 interposed therebetween, and the center of the electromagnetic coil 34 is disposed on the line segment M orthogonal to the line segment L.

  Further, returning to FIG. A lower waterproof pipe 35 is disposed so as to penetrate the horizontal portion 31B of the measurement tube 31, and the lower waterproof pipe 35 has a cylindrical shape and is formed in a stepped shape so that the upper part has a large diameter. . In the lower waterproof pipe 35, an upper waterproof pipe 44 described later is inserted into a large-diameter cylindrical portion.

  The conversion unit 40 basically includes a converter case 41 disposed on the upper portion of the measurement tube 31 and a converter 40A accommodated in the converter case 41. The converter case 41 has a cylindrical body portion 41B and a bottom portion 41C, and the bottom portion 41C has a rectifying portion 41A protruding downward in a substantially conical shape. The converter case 41 is disposed on the downstream side (upper side in FIG. 2) of the measurement tube 31. The converter 40 </ b> A is a signal indicating the flow rate of tap water detected by the pair of detection electrodes 33, specifically, the flow rate of tap water passing through the measurement tube 31 based on the potential difference generated between the pair of detection electrodes 33. And the calculated flow rate of the tap water is displayed on the display panel 42. Further, the converter 40A energizes and energizes the electromagnetic coil 34 when performing the measurement calculation.

  A converter ring 43 is fixed to the outer periphery of the converter case 41 at a substantially central portion in the height direction of the converter case 41, and the converter case 41 includes the flange of the converter ring 43 and the lower case 10. The upper case packing 51 is interposed between the upper case 11 and 10A.

  An upper waterproof pipe 44 is fixed to the bottom 41C of the converter case 41 so as to penetrate the bottom 41C. The lower end portion of the upper waterproof pipe 44 protrudes downward from the bottom portion 41C of the converter case 41, and an O-ring 52 is interposed on the outer periphery thereof. The upper waterproof pipe 44 is inserted and joined to the lower waterproof pipe 35 described above.

  As described above, the lead pipe (not shown) connecting the detection electrode 33, the electromagnetic coil 34, and the converter 40A is inserted into the waterproof pipe constituted by the lower waterproof pipe 35 and the upper waterproof pipe 44. .

  Here, the waterproof pipe composed of the lower waterproof pipe 35 and the upper waterproof pipe 44 is formed between the bottom 41C of the converter case 41 and the downstream end (upper end in FIG. 2) of the measuring tube 31. The position where the flow resistance of tap water flowing out from the measurement pipe 31 is reduced in the gap, specifically, as shown in FIG. 3, the inlet 12 side (with respect to the central axis 31C of the measurement pipe 31 ( In FIG. 2, they are arranged on the right side of the measuring tube 31 and the converter case 41.

Next, a connection structure between the measurement tube 31 and the converter case 41 will be described. The measurement tube 31 and the converter case 41 are connected and fixed to each other via a connection bracket 53. As shown in FIG. 4, the connection bracket 53 has a base 53A and a plurality of (three) feet 53B. The base 53A is fixed to the bottom 41C of the converter case 41. The lower end portion of each foot portion 53B is fixed to the downstream end portion (upper end portion in FIG. 2) of the measurement tube 31 and the measurement tube case 32. Thus, the converter case 41 and the measurement tube 31 are fixedly connected while forming a gap between the bottom 41C of the converter case 41 and the upper end of the measurement tube 31 and the measurement tube case 32.
Note that the foot portions 53B of the connection bracket 53 are formed at intervals of 120 degrees on the lower surface of the base portion 53A, and one foot portion 53B is on the inlet 12 side (see FIGS. 2 and 3) on the line segment L in FIG. The middle two positions) are fixed to the upper end of the measurement tube case 32, and the remaining two feet 53B are fixed to the upper end of the measurement tube case 32 at intervals of 120 degrees. Thereby, each leg part 53B of the connection bracket 53 will be arrange | positioned in the position which reduces the water-flow resistance of the tap water which flows out out of the measurement pipe | tube 31. FIG.

Then, the measuring method which measures the flow volume of tap water with the electromagnetic water meter 1 comprised as mentioned above is demonstrated.
In order to measure the flow rate of tap water, the electromagnetic coil 34 is excited by the converter 40A. Thereby, a magnetic field is generated in the measuring tube 31. When conductive tap water passes through the measurement tube 31, a potential difference corresponding to the flow rate of tap water is generated between the pair of detection electrodes 33. The generated potential difference is transmitted to the converter 40A via a lead wire (not shown) inserted through the lower waterproof pipe 35 and the upper waterproof pipe 44. In the converter 40A, the flow rate is calculated based on the potential difference. The calculated flow rate is displayed on the display panel 42.

At this time, the direction of the tap water flowing into the lower case 10 from the water pipe through the inlet 12 is changed to a substantially vertical upper direction in the lower room 15, passes through the measuring pipe 31 and enters the upper room 16. Move and head from the upper room 16 to the outlet 13. Since the flow direction changes in the lower chamber 15, so-called drift, which is a deviation in flow velocity, occurs in the measurement tube 31. Specifically, in the horizontal cross section of the measurement tube 31, the flow velocity is slow on the inlet 12 side and the flow velocity is fast on the outlet 13 side. That is, the position where the peak of the flow velocity is shifted from the central axis 31C of the measuring tube 31, and the flow velocity from high speed to low speed is distributed on the line segment L. Therefore, if the pair of detection electrodes 33 are arranged opposite to each other on the component L, it is possible to measure over the basin from low speed to high speed.
On the other hand, for example, when the pair of detection electrodes 33 are arranged on the line segment M orthogonal to the line segment L, it becomes impossible to measure high and low flow rates. Only the intermediate flow rate will be measured. As a result, the measurement accuracy may be reduced.
As described above, if the pair of detection electrodes 33 are arranged opposite to each other on the line segment L, the entire range of the distribution including the peak of the flow velocity and including the high and low flow velocity can be measured. It can be carried out.
As described above, the position at which the detection electrode 33 is disposed is not limited to the line segment L, but is ± 10 degrees around the central axis 31C with respect to the line segment L as shown in FIG. The rotation range may be within the range. Within such a range, the flow rate can be accurately measured including the peak of the flow rate. As described above, in order to accurately measure the flow rate of tap water, each detection electrode 33 is arranged on the inner wall of the measurement tube 31 and can be arranged within a rotation range of ± 10 degrees with respect to the line segment L. Since it is possible, each detection electrode 33 can be easily arranged on the inner wall of the measurement tube 31.

  Next, a method for assembling the water meter 1 will be described with reference to FIGS. FIG. 4 is an exploded perspective view of the water meter 1. 5 to 10 are diagrams for explaining the assembly procedure.

  First, the lower waterproof pipe 35 is welded to the measurement tube 31, and the detection electrode 33 and the electromagnetic coil 34 are assembled to the measurement tube 31. Next, the measurement tube case 32 is welded to the measurement tube 31 (see FIG. 5). Subsequently, the upper waterproof pipe 44 and the converter ring 43 are welded to the converter case 41 (see FIG. 6).

  Next, the converter case 41 is placed on the base 53 </ b> A of the connection bracket 53, and the O-ring 52 is fitted into the upper waterproof pipe 44 and inserted into the lower waterproof pipe 35. Then, the converter case 41 and the base portion 53A of the connection bracket 53 are welded and joined, and the measuring tube case 32 and the foot portion 53B of the connection bracket 53 are welded and joined (see FIG. 7). At this time, the upper waterproof pipe 44, the lower waterproof pipe 35, and one leg portion 53 </ b> B of the connection bracket 53 are welded and joined so as to be disposed on the line segment L.

  Next, the shelf leakage preventing packing 55 is installed in the stepped portion 17 </ b> A provided in the insertion hole 17 of the lower case 10, and the bottom holder 54 is further inserted. Further, the upper case packing 51 is installed on the flange 10A of the upper case 11 (see FIG. 8). Next, the measurement tube packing 56 is assembled to the bottom of the measurement tube 31, and the measurement tube 31 is inserted into the lower case 10 together with the converter case 41 and the connection bracket 53 (see FIG. 9). Next, in order to assemble the upper case 11, the flange 10 </ b> A of the lower case 10, the upper case packing 51, and the upper case 11 are stacked in this order, and the bolt holes opened in the flange 10 </ b> A of the lower case 10, the upper case 11 and the upper case packing. The bolt 11A is inserted into the bolt hole opened in 51 and fastened (see FIG. 10). Thereafter, the converter 40A is assembled.

  As described above, according to the electromagnetic water meter 1 according to the present embodiment, the flow of tap water in the main body of the lower case 10 where the flow direction of tap water is changed between the inlet 12 and the outlet 13. Since the measuring pipe 31 is disposed in a portion where the direction changes, and the pair of detection electrodes 33 for detecting the flow rate of tap water is fixed to the measuring pipe 31, the vertical impeller-type water pipe in which the direction of the water flow changes in the case. The meter case can be diverted to an electromagnetic water meter, and the cost of the water meter can be significantly reduced.

  In addition, a measuring pipe 31 is arranged in a portion where the water flow direction of the tap water changes in the lower case 10 body where the water flow direction of the tap water is changed between the inlet 12 and the outlet 13, and the flow rate of the tap water is increased. Since the pair of detection electrodes 33 for detecting the flow rate are arranged opposite to each other within a predetermined range of the inner wall of the measurement tube 31 in which the deviation of the flow velocity occurs due to the change in the water flow direction in the measurement tube 31, Even when the flow rate deviation (uneven flow) of tap water occurs, the peak of the flow rate of tap water can be reliably detected, and the flow rate of tap water can be measured with high measurement accuracy.

  In addition, a predetermined range on the inner wall of the measurement tube 31 where the pair of detection electrodes 33 is arranged represents a direction of tap water flowing into the inlet 12 and a line segment L passing through the central axis 31C of the measurement tube 31. Assuming that the line segment L is rotated around the central axis 31C, the line segment L is defined by the range of the locus drawn on the inner wall of the measuring tube 31, and the range of the locus is defined by the line segment L as the central axis 31C. Since the line segment L corresponds to the range of the locus drawn on the inner wall of the measurement tube 31 when rotated around ± 10 degrees, the central portion of the detection portion 33B in each detection electrode 33 is the locus. Even if it is slightly deviated from the optimum position as long as it exists within the range, the peak of the flow rate of tap water can be reliably detected, and the flow rate of tap water can be measured with high measurement accuracy. Thus, flexibility can be given to the arrangement position of each pair of detection electrodes 33 on the inner wall in the measurement tube 31, so that each detection electrode 33 can be easily arranged on the inner wall of the measurement tube 31. It becomes possible.

  Further, a converter case 41 having a built-in converter 40A for calculating the flow rate of tap water based on a signal indicating the flow rate of tap water detected by the pair of detection electrodes 33 is disposed on the downstream side of the measurement pipe 31; Since the bottom 41C of the converter case 41 to which tap water flowing through the measurement pipe 31 hits is provided with a rectifying unit 41A for dispersing tap water from the measurement pipe 31 around the bottom 41C of the converter case 41, the measurement pipe 31 is provided. The tap water flowing out of the water is dispersed around the bottom of the converter case 41 by the rectifying unit 41A, and the stagnation and turbulence and separation of the water flow are suppressed. Thereby, the pressure loss of a water flow can be reduced.

  Further, it is formed inside the lower case 10 and fitted into the insertion hole 17 into which the upstream end of the measuring tube 31 is inserted, and is formed in an annular shape that holds the upstream end of the measuring tube 31. Since the bottom holder 54 is provided and the bottom surface portion 54A, which is the upstream end (lower end) of the bottom holder 54, is formed on the curved surface, the tap water flowing from the inlet 12 of the lower case 10 Since the water is guided smoothly at the bottom 54A, and the stagnation of the tap water and the turbulence / separation of the water flow are suppressed at the upstream end of the measuring tube 31, the pressure loss of the water flow can be reduced.

  Further, the stepped portion 17A is formed around the insertion hole 17 formed inside the lower case 10, and the flange portion 54B locked to the stepped portion 17A is formed around the bottom holder 54. The tap water is not leaked into the lower case 10 from between the upstream end of the measurement pipe 31 and the insertion hole 17, so that the tap water flowing from the inflow port 12 is surely supplied to the measurement pipe 31. It is possible to measure the amount of water accurately by flowing it.

  Further, by fixing the base 53A to the bottom 41C of the converter case 41 and fixing the end of each foot 53B to the downstream end of the measuring tube case 32, the bottom 41C of the converter case 41 and the measuring tube 31 are fixed. A connection bracket 53 is provided to connect the converter case 41 and the measurement pipe 31 while forming a gap between the downstream end and the foot 53B of the connection bracket 53 is discharged from the measurement pipe 31. Since it is arranged at a position where the water flow resistance is reduced, the foot portion 53B of the connection bracket 53 does not become the water flow resistance of the tap water flowing out from the measuring tube 31, thereby reducing the water flow resistance and reducing the water flow pressure. Loss can be reduced.

  In addition, the measurement tube case 32 that houses the measurement tube 31 while maintaining a gap with the outer peripheral surface of the measurement tube 31, and penetrates the bottom 41 </ b> C of the converter case 41 and the measurement tube 31 and the measurement tube case 32. There are provided a lower waterproof pipe 35 and an upper waterproof pipe 44 through which lead wires are inserted to electrically connect each detection electrode 33 and the converter 40A accommodated in the converter case 41, and the lower waterproof pipe 35 and The upper waterproof pipe 44 is located at a position where the flow resistance of the tap water flowing out from the measurement pipe 31 is reduced by a gap formed between the bottom 41C of the converter case 41 and the downstream end of the measurement pipe 31. Therefore, the lower waterproof pipe 35 and the upper waterproof pipe 44 do not become water flow resistance flowing out of the measurement pipe 31, thereby reducing the water flow resistance and reducing the pressure loss of the water flow. Can.

  In addition, the said embodiment does not limit this invention, Of course, various improvement and deformation | transformation are possible within the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 Electromagnetic water meter 10 Lower case 11 Upper case 12 Inlet 13 Outlet 15 Lower room 16 Upper room 17 Insertion hole 20 Meter main body 30 Measuring part 31 Measuring pipe 31C Center axis 32 Measuring pipe case 33 Detection electrode 34 Electromagnetic coil 35 Lower waterproof pipe 40 Converter 40A Converter 41 Converter case 41A Rectifier 44 Upper waterproof pipe 53 Connection bracket 54 Bottom holder

Claims (7)

A case main body having an inflow port through which tap water is introduced and an outflow port from which tap water is discharged, and the direction of tap water flow is changed between the inflow port and the outflow port;
A measuring tube disposed in a portion where the water flow direction of the tap water changes in the case body;
A pair of detection electrodes fixed to the measuring tube and detecting the flow rate of tap water;
A converter case for calculating the flow rate of tap water based on a signal indicating the flow rate of tap water detected by the pair of detection electrodes is built-in, and a converter case disposed on the downstream side of the measurement tube;
A base and a plurality of feet, and the base is fixed to the bottom of the converter case, and the end of each foot is fixed to the downstream end of the measurement tube, whereby the bottom of the converter case and the measurement tube A bracket for connecting the converter case and the measurement tube while forming a gap with the downstream end of the
There are three foot portions of the bracket, and these three foot portions are evenly arranged on the circumference centering on the central axis of the measuring tube, and one foot portion is tap water flowing into the inflow port. An electromagnetic system characterized in that it is arranged on the inlet side with respect to the central axis of the measurement tube on the line segment, assuming a line segment passing through the central axis of the measurement tube and representing the water flow direction of the measurement tube Water meter.   The pair of detection electrodes are arranged to face each other within a predetermined range of an inner wall of the measurement tube in which a deviation in flow velocity occurs due to a change in a water flow direction in the measurement tube. The electromagnetic water meter described. The predetermined range represents the direction of tap water flowing into the inflow port and assumes a line passing through the central axis of the measuring pipe, and when the line is rotated around the central axis, the line segment Defined by the range of the trajectory drawn on the inner wall of the measuring tube,
The trajectory range corresponds to a trajectory range drawn on an inner wall of a measurement tube when the line segment is rotated within a range of ± 10 degrees or less around a central axis. 2. The electromagnetic water meter according to 2. Claim 1, characterized in that provided at the bottom of the converter case tap water flowing through the pre-Symbol measurement tube strikes, including a rectifying unit that distributed around the bottom of the converter case tap water from the measuring tube The electromagnetic water meter according to claim 3. An insertion hole formed in the case body and into which the upstream end of the measurement tube is inserted;
A holder member that holds the upstream end of the measurement tube and is fitted into the insertion hole and formed in an annular shape,
The electromagnetic water meter according to any one of claims 1 to 4, wherein a curved portion is formed at an upstream end portion of the holder member. A step is formed around the insertion hole,
The electromagnetic water meter according to claim 5, wherein a collar portion locked to the step portion is formed around the holder member. A measuring tube case for storing the measuring tube while maintaining a gap with the outer peripheral surface of the measuring tube;
Waterproof that penetrates the bottom of the converter case and is disposed in the gap between the measurement tube and the measurement tube case, and through which wiring for electrically connecting the detection electrodes and the converter housed in the converter case is inserted With pipes,
The waterproof pipe represents the direction of tap water flowing into the inflow port in a gap formed between the bottom of the converter case and the downstream end of the measurement pipe, and a line segment passing through the center axis assumed, according to any one of claims 4 to 6, characterized in that it is arranged on the inlet side with respect to the central axis of the measuring tube on the line segment Electromagnetic water meter.

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