JP2005189090A - Ultrasonic water meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic water meter capable of reducing a space for attaching to a water pipe while ensuring a propagation distance of ultrasonic waves.
In an ultrasonic water meter 60 of the present invention, a pair of ultrasonic transducers 76 and 76 are arranged at both ends of a substantially U-shaped meandering water channel 68, and both of these ultrasonic transducers are transmitted and received. Since the ultrasonic waves transmitted and received between the vessels 76 and 76 are propagated to the tap water flowing in the meandering water channel 68, the space for attaching to the water pipe can be reduced while ensuring the propagation distance of the ultrasonic waves. . Further, since the meandering water channel 68 has a corner U shape in which the lower ends of the vertical straight portions 69 and 69 are connected by the horizontal straight portion 70, the meandering water channel 68 is rounded and becomes substantially U-shaped. Compared to that, the number of reflections of ultrasonic waves on the inner surface of the meandering water channel 68 can be reduced.
[Selection] Figure 4

Description

  The present invention relates to a water meter for measuring the flow rate of tap water, and more particularly to an ultrasonic water meter that measures the flow rate using an ultrasonic transducer.

  In general, an ultrasonic flow meter has a structure in which a pair of ultrasonic transducers are arranged separately on an upstream side and a downstream side of a straight pipe line. Then, ultrasonic waves are transmitted and received between the ultrasonic transducers in both the forward direction and the reverse direction along the flow of the fluid, and the difference between the arrival times of the ultrasonic waves in the forward direction and the reverse direction is obtained. Then, the flow rate of the fluid is measured (for example, refer to Patent Document 1).

On the other hand, the current water meter is not an ultrasonic type using the above principle, but an impeller type is widely used. That is, the current water meter is equipped with an impeller inside a meter case connected to a water pipe, and the impeller is rotated by tap water and the flow rate of tap water is measured based on the rotation. (For example, see Patent Document 2).
Japanese Patent Laid-Open No. 10-62219 (paragraph [0021], FIGS. 1 and 4) JP 2003-207377 (paragraph [0041], FIG. 1)

  By the way, under the present circumstances, the water meter which applied the structure of the said ultrasonic flowmeter is not distribute | circulating. The reason for this is that in the water meter to which the above-described ultrasonic flow meter configuration is applied, the ultrasonic propagation distance must be secured to a predetermined length or more, so the total length of the straight pipe line is the same as that of the impeller water meter. This is because it is difficult to replace the current impeller water meter attached to the water pipe with an ultrasonic water meter that is longer than the total length. Currently, the impeller-type water meter is periodically removed from the water pipe, and the components inside the meter case are maintained and used continuously.

  This invention is made | formed in view of the said situation, and it aims at provision of the ultrasonic water meter which can make the space for attaching to a water pipe small, ensuring the propagation distance of an ultrasonic wave.

  The ultrasonic water meter according to the invention of claim 1, which has been made to achieve the above object, has tap water in a substantially U-shape or a substantially V-shape inside a meter case connected in the middle of a water pipe. In addition to forming a meandering water channel that flows in a meandering manner, a pair of ultrasonic transducers are provided at both U-shaped and V-shaped tip portions of the meandering water channel, and waves are transmitted and received between these ultrasonic transducers. The ultrasonic wave is propagated to tap water flowing through a meandering water channel, and the flow rate of tap water is measured based on the propagation time.

  The ultrasonic water meter according to claim 1 is characterized in that in the ultrasonic water meter according to claim 1, the side water channels are respectively communicated from the side to the positions close to both ends of the U-shaped or V-shaped meandering water channels, and ultrasonic transmission / reception is performed. The waver is characterized in that it is disposed further to the tip side than the connecting portion with the side water channel in the meandering water channel.

  The invention according to claim 3 is the ultrasonic water meter according to claim 1 or 2, wherein the meandering water channel has a square U shape in which the lower end of a pair of vertical linear portions is connected by a horizontal linear portion, At the intersection of the vertical straight portion and the horizontal straight portion, an ultrasonic wave that is inclined by 45 degrees with respect to the axial direction of the vertical straight portion and propagated along the vertical straight portion passes along the horizontal straight portion. It is characterized in that it has a reflective slope that reflects in the direction.

  According to a fourth aspect of the present invention, in the ultrasonic water meter according to any one of the first to third aspects, an inner body is provided with an open port on the upper surface of the meter case and a meandering water channel inside the meter case. Is inserted, the opening is closed by the inner body, and the upper wall of the inner body is formed with a through hole that communicates with the meandering water channel and is blocked by the ultrasonic transducer, and is formed on the upper surface of the upper wall. Is characterized in that a signal processing circuit electrically connected to the ultrasonic transducer is disposed.

  The invention of claim 5 is characterized in that in the ultrasonic water meter according to any one of claims 1 to 4, the meter case is formed so as to be divertable between the impeller water meter.

  The invention of claim 6 is characterized in that in the ultrasonic water meter according to any one of claims 1 to 5, the meter case used is the one used for the impeller water meter.

[Invention of Claim 1]
The ultrasonic water meter according to claim 1 has a pair of ultrasonic transducers disposed at both ends of a substantially U-shaped or substantially V-shaped meandering water channel, and the space between these ultrasonic transducers. Since the ultrasonic wave transmitted / received in is propagated to the tap water flowing in the meandering water channel, the space for attaching to the water pipe can be reduced while ensuring the propagation distance of the ultrasonic wave.

[Invention of claim 2]
If the ultrasonic water meter of Claim 2 is attached in the middle of a water pipe, the tap water which flowed into the meter case from the water pipe will flow in order of one side water channel, a meandering water channel, and the other side water channel. In the ultrasonic water meter of the present invention, since the ultrasonic transducer is arranged on the tip side from the contact portion with the side water channel in the meandering water channel, the tap water is obstructed by the ultrasonic transducer. It flows smoothly without.

[Invention of claim 3]
Since the meandering water channel of the ultrasonic water meter according to claim 3 has a square U shape in which the lower end of the pair of vertical straight portions is connected by the horizontal straight portion, the meandering water channel is rounded and substantially U-shaped. The number of ultrasonic reflections on the inner surface of the meandering waterway can be reduced compared to the letter-shaped one.

[Invention of claim 4]
In the ultrasonic water meter according to claim 4, the signal processing circuit is waterproofed by closing the through hole of the upper wall of the inner body with an ultrasonic transducer and arranging the signal processing circuit on the upper surface of the upper wall. However, the connection between the ultrasonic transducer and the signal processing circuit can be easily performed.

[Invention of claim 5]
In the ultrasonic water meter according to claim 5, since the meter case is formed to be divertable with the impeller water meter, the current impeller water meter attached to the water pipe is ultrasonicated. It can be easily replaced with a water meter. Also, since it is only necessary to manufacture meter cases with the same structure for both ultrasonic and impeller water meters, the number of manufacturing lots is increased and manufacturing costs are reduced compared to the case of manufacturing meter cases with different structures. Can be suppressed.

[Invention of claim 6]
In the ultrasonic water meter according to claim 6, since the meter case used for the impeller water meter is diverted, resources can be reused. In addition, it is possible to easily switch from the impeller water meter to the ultrasonic water meter using the maintenance work of the impeller water meter.

[First Embodiment]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows the overall structure of the meter case 11. The meter case 11 has a structure in which a pair of connecting pipes 14 and 14 are extended in opposite directions from the outer peripheral surface of the cylindrical body 13, and a water pipe 19 (see FIGS. 2 and 4) is connected to the connecting pipes 14 and 14. Link). The tip opening of the left connecting pipe 14 in FIG. 2 forms the inflow port 14A, while the tip opening of the connecting pipe 14 on the opposite side forms the outflow port 14B. The inside of the meter case 11 is divided into a lower room 13A extending downward from the inflow port 14A and an upper room 13B located above the lower room 13A. The upper room 13B and the lower room are separated from each other. 13 </ b> A overlaps vertically in the cylindrical body 13 and communicates via the communication port 17.

  An open port 20 is formed at the upper end of the cylindrical body 13 of the meter case 11, and the inner body 12 for the impeller 12 (see FIG. 2) or the inner body for ultrasonic waves is provided from the open port 20 to the inside of the meter case 11. 62 (see FIG. 4) is selectively assembled. And if the inner body 12 for impellers is assembled | attached to the meter case 11, the impeller-type water meter 10 (refer FIG.2 and FIG.3) will be comprised, and if the inner body 62 for ultrasonic waves is assembled | attached to the meter case 11, this invention will be described. The ultrasonic water meter 60 (refer FIG. 4) which concerns is comprised.

  First, the impeller water meter 10 will be described. As shown in FIG. 2, the impeller inner body 12 for constituting the impeller-type water meter 10 includes an impeller 32 inside, and the impeller 12 according to the flow rate flowing in the impeller inner body 12. 32 rotates. A stepped portion 33 is provided in the middle of the impeller inner body 12 in the axial direction, and the stepped portion 33 is pressed against the edge of the communication port 17 in the meter case 11 from above. A partition wall 31 is provided above the impeller 32 in the inner body 12 for the impeller, and a waterproof room 30 is provided above the partition wall 31. The rotation of the impeller 32 is transmitted between the magnet 39 provided at the upper end of the impeller 32 and the magnetic sensor 40 provided in the waterproof room 30.

  A semicircular groove 41 having a semicircular cross section extends in the axial direction on the outer peripheral surface of the inner body 12 for the impeller, and a semicircular groove having a semicircular cross section is also formed on the inner peripheral surface of the opening 20 corresponding thereto. 42 extends in the axial direction. A pin 50 is assembled in a hole formed by facing both the semicircular grooves 41 and 42, and the inner body 12 for the impeller is prevented from rotating in the meter case 11.

  A flange 35 projects from the upper end of the inner body 12 for the impeller toward the side, and a packing 36 is sandwiched between the flange 35 and the upper edge of the opening 20. An upper surface cover 15 is assembled from above the inner body 12 for the impeller. The upper surface cover 15 is formed by covering the upper surface of a flat cylindrical body with a glass plate 15A. The top cover 15 is screwed into the upper end portion of the cylindrical body 13 so as to cover the top of the impeller inner body 12 and is pressed against the impeller inner body 12. Thereby, the packing 36 is crushed and the opening 20 of the cylindrical body 13 is sealed. As shown in FIG. 3, a swing lid 15B for covering the glass plate 15A can be attached to the top cover 15.

  The impeller-type water meter 10 configured in this way is attached in the middle of a water pipe so that the tap water flows in the direction of the arrow 11A shown in FIG. Then, as shown by the thick arrow in FIG. 2, the tap water that has flowed into the inner body 12 for the impeller from the lower chamber 13A of the meter case 11 passes through the impeller 32 and proceeds to the upper chamber 13B. It is discharged from the inlet 14A. Thereby, the impeller 32 rotates, and the rotation is transmitted to the waterproof room 30 side by the magnetic sensor 40. Then, a counter 31C (see FIG. 3) provided in the waterproof chamber 30 is operated in conjunction with the rotation of the impeller 32, and the flow rate of tap water (more specifically, the integrated flow rate) is Displayed through the glass plate 15A.

  Next, the ultrasonic water meter 60 according to the present invention will be described. As shown in FIG. 5, the ultrasonic inner body 62 for constituting the ultrasonic water meter 60 has a structure in which a small diameter cylindrical portion 64 protrudes from the lower end surface of the large diameter cylindrical portion 63. The ultrasonic inner body 62 is inserted into the opening 20 of the meter case 11 from the small-diameter cylindrical part 64 side, and the large-diameter cylindrical part 63 is fitted to the inner peripheral surface of the opening 20, and The outer edge of the lower end of the diameter cylindrical portion 63 is pressed from above onto the edge of the communication port 17 in the meter case 11.

  Further, as shown in FIG. 4, a semicircular groove 41C having a semicircular cross section is formed on the outer peripheral surface 62A of the ultrasonic inner body 62 in the same manner as the impeller inner body 12, and this semicircular groove A pin 50 is assembled in a hole formed by opposing 41C and the semicircular groove 42 formed on the inner peripheral surface of the opening 20. Accordingly, the ultrasonic inner body 62 is prevented from rotating in the meter case 11. Further, a flange 65 projects laterally from the upper end portion of the large diameter cylindrical portion 63. As in the case of the inner body 12 for the impeller, the packing 36 is sandwiched between the flange 65 and the upper end edge of the opening 20, and the upper surface cover 15 is assembled from above the meter case. 11 open ports 20 are sealed.

  A recess 66 is formed on the upper surface of the large-diameter cylindrical portion 63 of the ultrasonic inner body 62, and the bottom of the recess 66 is an upper wall 67 of the ultrasonic inner body 62. A meandering water channel 68 according to the present invention is formed between the upper wall 67 of the ultrasonic inner body 62 and the lower surface of the small-diameter cylindrical portion 64.

  The meandering water channel 68 has a square U shape in which the lower end of the pair of vertical linear portions 69 and 69 is connected by the horizontal linear portion 70. Reflective slopes 71, 71 that are inclined at 45 degrees with respect to the axial direction of the vertical straight portions 69, 69 are formed at the intersections of the vertical straight portions 69, 69 and the horizontal straight portions 70. Further, as shown in FIG. 6, the meandering water channel 68 is sandwiched between the inner side surfaces 68 </ b> A and 68 </ b> A parallel to each other in the direction orthogonal to the opposing direction of the vertical straight portions 69 and 69, and the width dimension is constant. .

  As shown in FIG. 4, the partition wall 72 provided between the pair of longitudinal straight portions 69 and 69 is constricted at the upper end portion and gradually bulges sideward toward the lower end side. Has a rounded shape. Thereby, tap water flows smoothly along the partition wall 72 in the meandering water channel 68.

  In addition, side water channels 73 and 74 are communicated with the upper ends of the vertical linear portions 69 and 69 from the sides. One side water channel 73 opens to the lower end surface of the large-diameter cylindrical portion 63 in the ultrasonic inner body 62 and communicates with the lower chamber 13 </ b> A of the meter case 11. The other side water channel 74 opens to the outer peripheral surface of the ultrasonic inner body 62 and communicates with the upper chamber 13 </ b> B of the meter case 11. Thereby, the tap water which flowed in the meter case 11 flows in order of the one side water channel 73, the meandering water channel 68, the other side water channel 74, and the upper room 13B from the lower room 13A. The side water channels 73 and 74 are both sandwiched between inner surfaces 68A and 68A (see FIG. 6) common to the meandering water channel 68 and have the same width as the meandering water channel 68.

  Now, on the upper wall 67 of the ultrasonic inner body 62, as shown in FIG. 4, ultrasonic transducers 76, 76 are provided at both ends of the meandering water channel 68, respectively. Specifically, the through holes 75 and 75 are formed on the extension lines of the longitudinal straight portions 69 and 69 in the meandering water channel 68. Ultrasonic transducers 76 and 76 are fitted and attached to the through holes 75 and 75, respectively. Specifically, as shown in FIG. 7, the ultrasonic transducer 76 has, for example, a structure in which a flange 76F protrudes laterally from one end of a flat cylindrical sensor body 76A, and the other end of the sensor body 76A. The end surface on the part side is a transmission / reception surface 76B.

  Further, as shown in FIG. 8, the through hole 75 is gradually increased in inner diameter in a stepwise manner toward the upper surface side of the upper wall 67. The ultrasonic transducer 76 is inserted into the through hole 75 from the upper surface side of the upper wall 67 with the transmitting / receiving surface 76B facing downward, and an O-ring 77 is provided between the step portion of the through hole 75 and the flange 76F. It is sandwiched. Further, the flange 76F is pressed downward by a ring plate 78 screwed to the upper surface of the upper wall 67, whereby the through hole 75 is sealed in a watertight state.

  The electric wires extending upward from the ultrasonic transducers 76 and 76 are connected to a circuit board 79 provided on the upper surface of the upper wall 67. FIG. 9 shows an electric circuit formed by connecting ultrasonic transducers 76 and 76 to a signal processing circuit 80A mounted on a circuit board 79. As shown in the drawing, both ultrasonic transducers 76, 76 (hereinafter, in order to distinguish between the upstream and downstream ultrasonic transducers 76, 76, hereinafter, “upstream transducer 76U” And “downstream transmitter / receiver 76 </ b> D”) are both ultrasonic transducers and function as ultrasonic transmission elements when connected to the transmission circuit 81, while being connected to the reception circuit 82. Functions as an ultrasonic receiving element. One of the upstream and downstream transducers 76U and 76D is selectively connected to the transmission circuit 81 and the other is connected to the reception circuit 82. Therefore, as shown in FIG. 9, the upstream side transducer 76U is connected to the transmission circuit 81 and the downstream side transducer 76D is connected to the reception circuit 82, so While the sound wave can be transmitted and received, the upstream-side transducer 76U is connected to the receiving circuit 82 and the downstream-side transducer 76D is connected to the transmitting circuit 81, so Sound waves can also be transmitted and received.

  A control unit 83, a clock counter 84, and a repetition number counter 85 are connected to the transmission circuit 81 and the reception circuit 82 described above. The control unit 83 controls the switches SW1 and SW2, and first connects the upstream transducer 76U to the transmission circuit 81 and connects the downstream transducer 76D to the reception circuit 82, as shown in FIG. A transmission command signal is output to the transmission circuit 81 after the state has been achieved. Then, the transmission circuit 81 drives the upstream-side transducer 76U, and at the same time as the ultrasonic wave is transmitted from the upstream-side transducer 76U, the clock counter 84 starts measuring time based on the clock pulse. . The ultrasonic wave transmitted from the upstream transducer 76U propagates through the tap water in the meandering water channel 68 and is received by the downstream transducer 76D after a predetermined time.

  Specifically, as shown in FIG. 4, the ultrasonic wave transmitted from the upstream-side transducer 76U is directed vertically downward along the longitudinal straight portion 69 on the upstream side of the meandering water channel 68, and the longitudinal straight portion. 69 is reflected by the reflecting slope 71 at the lower end portion 69 and faces the horizontal direction along the horizontal straight portion 70, is reflected by the downstream reflecting slope 71 in the horizontal straight portion 70, is directed vertically upward, and is The vertical linear portion 69 travels vertically upward and is received by the downstream transducer 76D.

  Then, a reception detection signal is output to the repetition number counter 85 and the transmission circuit 81 from the reception circuit 82 connected to the downstream-side transmitter / receiver 76D. The transmission circuit 81 receives the reception detection signal and simultaneously drives the upstream-side transmitter / receiver 76U again. The repetition number counter 85 is incremented by 1 every time a reception detection signal is received, and does not output a signal to any circuit until the count number reaches n times. When the count number reaches n, the nth received wave detection signal is output from the repetition number counter 85 to the control unit 83, the clock counter 84, and the transmission circuit 81. Receiving this, the clock counter 84 stops time measurement, outputs the measurement result to the control unit 83, and is reset to zero.

When receiving the nth received wave detection signal, the transmission circuit 81 stops driving the upstream side transmitter / receiver 76U, and then enters a waiting state for a transmission command signal output from the control unit 83. The control unit 83 receives the nth received wave detection signal, stores the count result received from the clock counter 84, drives the switches SW1 and SW2, and sends the wave transmitting circuit 81 to the downstream wave transmitter / receiver 76D. Then, the wave receiving circuit 82 is connected to the upstream wave transmitter / receiver 76U. Then, the control unit 83 outputs a transmission command signal to the transmission circuit 81 after allowing time for noise and the like to converge. As a result, this time, the same processing as described above is performed with the ultrasonic wave transmission direction reversed.
In this case, contrary to the case described above, the ultrasonic wave transmitted from the downstream-side transducer 76 </ b> D runs backward to the flow of tap water and moves vertically downward in the vertical straight portion 69 on the downstream side of the meandering water channel 68. And reflected by the reflecting slope 71 and proceeding in the horizontal linear portion 70 in the horizontal direction, and reflected by the other reflecting slope 71 and proceeding in the upstream vertical straight portion 69 vertically upward to transmit and receive upstream waves. Is received by the device 76U.

  Then, the difference between the count values of the clock counter 84 measured in both the forward direction and the reverse direction with respect to the fluid is obtained, and the flow velocity / flow rate of the fluid is calculated based on the difference between the count values. The calculated flow velocity / flow rate is displayed by, for example, a 7-segment LED mounted on the circuit board 79, and can be seen through the glass plate 15A. That is, the ultrasonic water meter 60 is configured by assembling the ultrasonic inner body 62 to the meter case 11 common to the impeller water meter 10, and measures the flow rate of tap water in the same manner as the impeller water meter 10. can do.

  As described above, according to the ultrasonic water meter 60 of the present embodiment, a pair of ultrasonic transducers 76 and 76 are disposed at both ends of the substantially U-shaped meandering water channel 68, and both the ultrasonic waves Since the ultrasonic waves transmitted and received between the transducers 76 and 76 are propagated to the tap water flowing in the meandering water channel 68, the space for attaching to the water pipe is reduced while ensuring the propagation distance of the ultrasonic waves. Can do. Further, since the meandering water channel 68 has a corner U shape in which the lower ends of the vertical straight portions 69 and 69 are connected by the horizontal straight portion 70, the meandering water channel 68 is rounded and becomes substantially U-shaped. Compared to that, the number of reflections of ultrasonic waves on the inner surface of the meandering water channel 68 can be reduced. Since the ultrasonic transducers 76 and 76 are disposed on the distal end side from the connecting portions (73A and 74A in FIG. 4) with the side water passages 73 and 74 in the longitudinal linear portions 69 and 69 of the meandering water passage 68. The tap water flows smoothly without being disturbed by the ultrasonic transducers 76 and 76.

  Further, the through hole 75 of the upper wall 67 in the ultrasonic inner body 62 is closed by the ultrasonic transducers 76 and 76, and the signal processing circuit 80A is disposed on the upper surface of the upper wall 67. It is possible to easily connect the ultrasonic transducers 76 and 76 and the signal processing circuit 80A while waterproofing. And since the meter case 11 of the ultrasonic water meter 60 can be diverted between the impeller water meter 10, the current impeller water meter 10 attached to the water pipe 19 is ultrasonicated. The water meter 60 can be easily replaced. Further, it is possible to easily switch from the impeller water meter 10 to the ultrasonic water meter 60 by using the maintenance work of the impeller water meter 60. Furthermore, since it is only necessary to manufacture the meter case 11 having the same structure for both the ultrasonic and impeller-type water meters, the number of manufacturing lots is increased as compared with the case where the meter cases having different structures are manufactured. Cost can be reduced.

[Second Embodiment]
The ultrasonic water meter 90 of this embodiment is shown in FIG. The ultrasonic water meter 90 is smaller than the ultrasonic water meter 60 described in the first embodiment, and the structure of the meter case 91 is different from the meter case 11 of the first embodiment. The shape of a part of the ultrasonic inner body 92 is different from the ultrasonic inner body 62 of the first embodiment. Hereinafter, only the configuration different from that of the first embodiment will be described, and the same configuration is denoted by the same reference numeral, and redundant description is omitted.

  A step portion 91D is formed at a position near the upper end of the inner peripheral surface of the meter case 91 of the present embodiment. The lower end surface outer edge portion of the large-diameter cylindrical portion 63 of the ultrasonic inner body 92 is in contact with the stepped portion 91D. Further, a pair of ribs (not shown) are formed from the outer peripheral surface of the small-diameter cylindrical portion 64 in both directions orthogonal to the paper surface of FIG. 10, so that the cylindrical space below the large-diameter cylindrical portion 63 becomes the inlet 14A. And the outlet 14B side.

The side water passages 73E and 74E communicating with the meandering water passage 68 in the ultrasonic inner body 92 are both open on the lower surface of the large-diameter cylindrical portion 63. As a result, the tap water that has flowed into the meter case 91 from the inflow port 14A, as shown by the thick arrows in FIG. It flows in order. Further, the bottom surface of the meter case 91 is formed with a screw hole 93 to which the rotation support shaft of the impeller is attached when the meter case 91 is used for the impeller water meter. The screw hole 93 is closed by the bottom surface of the ultrasonic inner body 92 being applied.
The ultrasonic water meter 90 according to the present embodiment configured as described above also has the same effects as those of the first embodiment.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

  (1) The meandering water channel 68 in the first and second embodiments is substantially U-shaped, but is substantially V-shaped meandering water channel 95 like the ultrasonic water meter shown in FIG. You may make it the structure provided with.

  (2) In the ultrasonic water meters 60 and 90 of the first and second embodiments, the meter cases 11 and 91 are diverted between the impeller water meter, but the diversion is impossible. It may be configured.

The perspective view of the meter case which concerns on 1st Embodiment of this invention. Side section of impeller water meter Perspective view of ultrasonic water meter Side view of ultrasonic water meter Perspective view of inner body Partial perspective view of inner body Perspective view of ultrasonic transducer Cross-sectional side view with ultrasonic transducer installed Block diagram showing the electrical configuration of an ultrasonic water meter Side sectional view of an ultrasonic water meter according to the second embodiment Side sectional view of an ultrasonic water meter according to a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Impeller-type water meter 11,91 Meter case 19 Water pipe 20 Opening port 60 Ultrasonic-type water meter 60 Impeller-type water meter 60,90 Ultrasonic-type water meter 62,92 Ultrasonic inner body 62A Outer surface 67 Upper part Wall 68, 95 Meandering water channel 69 Straight line part 70 Horizontal straight line part 71 Reflective slope 73, 74, 73E, 74E Side water channel 75 Through-hole 76 Ultrasonic transducer 80A Signal processing circuit

Claims (6)

  Inside the meter case connected in the middle of the water pipe, a meandering water channel that tapers and flows in a substantially U-shape or a substantially V-shape is formed, and the U-shape or the V-shape among the meandering water channels. A pair of ultrasonic transducers are provided at both ends of the ultrasonic wave, and ultrasonic waves transmitted and received between the ultrasonic transducers are propagated to tap water flowing in the meandering water channel, and based on the propagation time. An ultrasonic water meter that measures the flow rate of tap water. In the meandering water channel, the side water channel is communicated from the side to the positions near both ends of the U-shaped or V-shaped,
2. The ultrasonic water meter according to claim 1, wherein the ultrasonic wave transmitter / receiver is disposed further on a distal end side than a connecting portion with the side water channel in the meandering water channel.   The meandering water channel has a rectangular U-shape in which the lower ends of a pair of vertical linear portions are connected by a horizontal linear portion, and the vertical straight line is formed at the intersection of the vertical linear portion and the horizontal linear portion. And a reflecting slope that reflects the ultrasonic wave propagating along the vertical linear portion in a direction along the horizontal linear portion. The ultrasonic water meter according to claim 1 or 2. On the upper surface of the meter case, an opening is provided,
An inner body having the meandering water channel is inserted inside the meter case, the opening is closed by the inner body, and the upper wall of the inner body communicates with the serpentine water channel and transmits and receives the ultrasonic wave. 4. A through-hole closed by a waver is formed, and a signal processing circuit electrically connected to the ultrasonic wave transmitter / receiver is disposed on an upper surface of the upper wall. The ultrasonic water meter according to any one of the above.   The ultrasonic water meter according to any one of claims 1 to 4, wherein the meter case is formed to be divertable with an impeller water meter. 6. The ultrasonic water meter according to claim 1, wherein the meter case used is an impeller water meter.

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