JP2012013491A - Flow rate meter and water supply pipe structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow rate meter that is made compact and measures an accurate flow rate compatibly, and a water supply pipe structure for installing the flow rate meter for each bibcock.SOLUTION: The flow rate meter 1 includes an impeller 7 disposed in a fluid passage 3 in a meter case in a substantially cylindrical shape. A partition part 6 is provided adjacently to the impeller 7, and a sensor mounting hole 11 is formed in the partition part 6. A magneto-resistance element 12 and a circuit board 13 are inserted into the sensor mounting hole 11. The circuit board 13 is provided with a pulse generation circuit 15 and a frequency division circuit 16, which divides the frequency of an output pulse signal from the pulse generation circuit 15 at a predetermined frequency division ratio to output the resulting signal to an external measurement unit 18. At a header 21 in which a main water supply pipe 20 branches out into branch pipings 23 to respective bibcocks 22, the flow rate meter 1 is formed integrally with each branch port 24 so that the flow rate meters 1 for flow rate measurement of the respective bibcocks 22 are all installed together at one place.

Description

  The present invention relates to a flow meter for measuring a flow rate of water or the like, and in particular, a flow meter that is compact and easy to install for each faucet and measures the flow rate in each faucet, and such a meter. The present invention relates to a water supply piping structure for installing a flow meter for each faucet.

  In order to suppress wasteful use of water and promote energy saving and resource saving, it is effective to raise water consumption awareness by clarifying the amount of water used. In a general house, piping is drawn to each part such as a kitchen, a washroom, a bath, and a toilet, and water is supplied. In order to clarify the amount of water used in each location, it is necessary to install a flow meter for measuring the amount of water used in each faucet or piping to each location.

  Here, as a flow meter, an impeller-type flow meter that installs an impeller in a flow path and outputs a pulse every rotation of the impeller (each unit flow rate) is generally used. Patent Document 1 discloses this type of flow meter. In the flow meter of Patent Document 1, a rotating magnetic field is generated by a magnet piece embedded in an impeller when the impeller rotates, and this rotating magnetic field is detected by a detection element of a magnetic sensor. The magnetic sensor includes a circuit board on which a detection element and a signal processing circuit connected thereto are provided, and performs a flow rate calculation process by outputting a pulse from the circuit board to the measurement unit.

JP 2002-39818 A

  If the impeller-type flow meter configured as in Patent Document 1 is configured compactly, the flow rate per rotation of the impeller is reduced, and thus the number of output pulses for the same flow rate is increased as compared with the related art. Therefore, if the pulse interval (pulse width) is shorter than the conventional one, and the high-speed pulse cannot be reliably received on the side of the measurement unit that receives this pulse and performs the flow rate calculation process, it cannot calculate the accurate flow rate. There is a problem. Further, when the wiring from the pulse generation circuit to the measurement unit is long, the output pulse is easily affected by noise, and there is a problem that accurate flow rate calculation is hindered by such noise.

  In addition, the conventional flow meter can be attached to the water supply mains like a water meter that measures the water consumption of the entire house, or it can be directly attached to faucets in various places such as kitchens and washrooms for water saving. There were many. Or even if it attaches to the piping of each location in a house, there is much for a temporary use amount investigation, and it was not supposed to use it permanently. For this reason, it cannot be said that sufficient consideration has been given to the installation space, the appearance after installation, and the ease of maintenance and installation work.

  In view of such a point, an object of the present invention is to propose a flow meter capable of measuring an accurate flow rate even when the number of output pulses per unit flow rate is increased by downsizing.

  Another object of the present invention is to facilitate and increase the efficiency of installing the flow meter as described above for each faucet, and to reduce the installation space without damaging the appearance near each faucet after installation. The purpose is to propose a water supply piping structure that can solve problems and is easy to maintain.

In order to solve the above problems, the flow meter of the present invention is:
A meter case in which a fluid passage is formed;
A rotating magnetic field generating means for generating a rotating magnetic field according to the flow rate of the fluid flowing through the fluid passage;
A detecting element for detecting the rotating magnetic field;
A pulse generation circuit that generates a pulse signal based on the output of the detection element, and a circuit board provided with a frequency dividing circuit that divides the pulse signal by a predetermined frequency dividing ratio,
A board mounting portion for inserting the circuit board is formed in the meter case.

  In this way, the frequency dividing circuit and the pulse generating circuit are provided on one circuit board and integrated into a flow meter, so that the pulse width and output interval of the pulse signal generated by the pulse generating circuit can be set to a predetermined value. It can be increased in proportion. Therefore, even when the flow meter is downsized, a pulse signal having an output interval that can be reliably received by the external measurement unit can be generated. Further, by inserting the circuit board into the meter case, the frequency dividing circuit and the pulse generating circuit can be built into the flow meter in a compact manner, and wiring connection from the outside is facilitated.

  In the present invention, the substrate mounting portion is formed in an extending portion extending into the fluid passage from the inner peripheral surface of the meter case adjacent to the rotating magnetic field generating means, and protrudes from the outer peripheral surface of the meter case. If the projecting portion is configured to open the insertion port of the circuit board to the board mounting portion, the circuit board can be mounted in a compact manner, and the flow meter can be formed in a compact shape. Also, if the detection element integrated with the rotating substrate is inserted into the substrate mounting portion, the mounting operation of the detection element can be performed easily and efficiently.

  Further, in this case, the rotating magnetic field generating means includes an axial-flow rotating impeller disposed coaxially in the fluid passage, and a magnet piece provided at a position off the rotation center of the impeller. If the structure is provided, the impeller can be rotated at a rotational speed corresponding to the flow rate of the fluid, and a rotating magnetic field corresponding to the flow rate can be generated.

Next, the water supply piping structure of the present invention is
A plurality of branch pipes for supplying fluid to a plurality of faucets;
In order to measure the flow rate in each faucet, provided with the above flow meter provided corresponding to each branch pipe,
The flow meter is integrally formed at a branch port in a header for branching the plurality of branch pipes from a water supply main pipe, or is connected to the header in each branch pipe or in the middle of the pipe near the connection part It is characterized by being attached to.

  Thus, if a flow meter is not installed in the faucet of each faucet or the pipe where the faucet is installed, and a flow meter is provided in or near the header of the water supply main, a flow meter is installed for each faucet. It is not necessary to change the method, and it can be installed with the same attachment method for multiple faucets. In addition, since the flow meters can be installed together in the vicinity of the header, it is not necessary to individually perform installation work at the installation location of each faucet, and it is not necessary to secure the installation location of the flow meter near each faucet. Therefore, the flow meter can be installed easily and efficiently. Moreover, maintenance can be performed efficiently. Furthermore, since the flow meter is not visible to the user as in the case where it is installed near the faucet, the appearance is not deteriorated. Furthermore, when the flow meter is integrally formed with the header, it is only necessary to connect a branch pipe to the header, and the flow meter can be installed more efficiently.

  In this case, for each flow meter, a wiring for connecting the circuit board and a higher-level measurement device is provided, and a plurality of the wires corresponding to the plurality of flow meters are connected from the header to the higher-level measurement device. It is desirable to route the wiring route together. In this way, since it is not necessary to perform wiring work individually from the vicinity of each faucet, wiring work between a higher-level measuring device that performs flow rate calculation processing and a plurality of flow meters can be performed easily and efficiently. Can do. Also, the maintenance of the wiring is easy.

  As described above, according to the present invention, even when the flow meter is downsized, a pulse signal having an output interval that can be reliably received by an external measurement unit can be generated. Further, the frequency dividing circuit and the pulse generating circuit can be compactly incorporated in the flow meter, and wiring connection from the outside is facilitated.

It is a front view of the flow meter concerning this embodiment. It is a rear view of the flow meter concerning this embodiment. It is a right view (side view seen from the outflow port side) of the flow meter which concerns on this Embodiment. It is a left view (side view seen from the inflow port side) of the flow meter which concerns on this Embodiment. It is a top view of the flow meter which concerns on this Embodiment. It is a bottom view of the flow meter concerning this embodiment. It is sectional drawing (XX sectional drawing of FIG. 5) of the flow meter which concerns on this Embodiment, and the front view of a magnetic sensor. It is explanatory drawing which shows schematic structure of the signal processing system in a flow meter. It is explanatory drawing of a water supply piping structure.

  Embodiments of a flow meter to which the present invention is applied will be described below with reference to the drawings.

(Flow meter)
1 is a front view of a flow meter according to the present embodiment, FIG. 2 is a rear view of the flow meter, FIG. 3 is a right side view of the flow meter (side view seen from the outlet side), and FIG. 5 is a top view of the flow meter, and FIG. 6 is a bottom view of the flow meter. FIG. 7A is a cross-sectional view of the flow meter (cross-sectional view along XX in FIG. 5), and FIG. 7B is a front view of the magnetic sensor. As shown in these drawings, the flow meter 1 includes a substantially cylindrical meter case 2, and a linear fluid passage 3 having a circular cross section as a whole is formed inside the meter case 2. One end of the fluid passage 3 is opened at one end of the meter case 2, and this opening is a fluid inlet 4 (see FIG. 4). Further, the other end of the fluid passage 3 is opened at the other end of the meter case 2, and this opening is a fluid outlet 5 (see FIG. 3) to the fluid passage 3.

  As shown in FIG. 7A, a partition wall 6 (extending portion) extending in a direction crossing the fluid passage 3 is formed at a position slightly on the outlet 5 side from the center of the fluid passage 3. ing. As shown in FIG. 3, the partition wall 6 closes only the central portion of the fluid passage 3. Therefore, the fluid flowing into the fluid passage 3 flows through the passage portions 3a and 3b (see FIG. 3) on both sides of the partition wall portion 6. An axial rotation type impeller 7 is disposed coaxially with the fluid passage 3 on the upstream side of the partition wall 6, and a rectifier 8 is disposed on the upstream side of the impeller 7. The impeller 7 is configured to rotate according to the flow rate of the fluid passing through the fluid passage 3. The rectifier 8 is configured to reduce the thrust force applied to the impeller 7 by generating a vortex in the fluid from the inlet 4 toward the impeller 7.

  A rotating shaft 7a of the impeller 7 protrudes on the downstream side at the center of the downstream end face (end face on the outlet 5 side) of the impeller 7. A shaft hole 6a into which the rotary shaft 7a can be inserted in a rotatable state is formed in a portion of the partition wall 6 that faces the rotary shaft 7a. On the other hand, a support shaft 8a that protrudes toward the impeller 7 is formed at the center of the downstream end surface of the rectifier 8, and the upstream end surface (inlet 4 side) of the impeller 7 that faces the support shaft 8a. A shaft hole 7b into which the support shaft 8a can be inserted in a rotatable state is formed at the center of the end surface. The impeller 7 is attached in a state where the rotating shaft 7a is inserted into the shaft hole 6a and the support shaft 8a is inserted into the shaft hole 7b. Thereby, the impeller 7 is supported in a state of being rotatable around the central axis L of the fluid passage 3.

  A cylindrical portion 8b disposed coaxially with the support shaft 8a is provided at the upstream end of the rectifier 8, and a rectifying plate 8c is disposed so as to divide the fluid passage in the cylindrical portion 8b into four. Yes. An umbrella-shaped rectifier body portion 8d formed coaxially with the support shaft 8a is provided on the downstream side of the cylindrical portion 8b and the rectifying plate 8c. A screw thread is formed on the outer peripheral surface of the cylindrical portion 8b. On the other hand, a step portion 2a having a one-step diameter larger than the inner peripheral surface on the partition wall portion 6 side is formed at the end portion on the inlet 4 side in the meter case 2, and the inner peripheral surface of the step portion 2a is formed on the inner peripheral surface. A thread groove is formed. The rectifier 8 is attached in the meter case 2 by screwing the cylindrical portion 8b into the step portion 2a.

  A magnet piece 9 is embedded in a downstream end portion of the impeller 7 at a position deviating from the rotation center line. Since the magnet piece 9 rotates around the central axis L as the impeller 7 rotates, a rotating magnetic field is generated as the impeller 7 rotates. The flow meter 1 includes a magnetic sensor 10 for detecting the rotating magnetic field and generating a pulse signal corresponding to the rotating magnetic field. A sensor mounting hole 11 (substrate mounting portion) is formed inside the partition wall portion 6 disposed adjacent to the impeller 7. The magnetic sensor 10 includes a magnetoresistive element 12 (detection element) and a circuit board 13 housed in the sensor mounting hole 11.

  The insertion hole 11 a of the circuit board 13 into the sensor mounting hole 11 opens at the tip end surface of the protruding portion 14 protruding from the meter case 2 toward the outer peripheral side. The sensor mounting hole 11 is a recess extending from the insertion port 11 a to a position slightly deeper than the center of the fluid passage 3. The magnetoresistive element 12 is disposed at the lower end of the circuit board 13 as shown in FIG. The magnetoresistive element 12 and the circuit board 13 are detachably fixed in the sensor mounting hole 11 via a holder, a fixing member or the like (not shown). The magnetoresistive element 12 and the circuit board 13 may be fixed in the sensor mounting hole 11 with a molding material such as resin. The circuit board 13 is inserted into the sensor mounting hole 11 so that one end of the circuit board 13 extends to the insertion hole 11a side of the sensor mounting hole 11, and the end of the circuit board 13 on the insertion hole 11a side is connected to an external device. A connection terminal is provided.

  FIG. 8 is an explanatory diagram showing a schematic configuration of a signal processing system in the flow meter. A circuit board 13 inserted in the sensor mounting hole 11 together with the magnetoresistive element 12 is provided with a pulse generating circuit 15 and a frequency dividing circuit 16. As shown in FIG. 8, the output of the magnetoresistive element 12 accompanying the rotation of the impeller 7 is input to the pulse generation circuit 15. The pulse generation circuit 15 outputs a predetermined number of pulse signals for each rotation of the impeller 7. This pulse signal is input to the frequency dividing circuit 16. The frequency divider circuit 16 divides the input pulse signal by a predetermined frequency division ratio, converts the input pulse signal into a pulse signal having an integer multiple of the pulse interval, and outputs the pulse signal. An output pulse signal from the frequency divider circuit 16 is input to an external measurement unit 18 (high-order measurement device) via a wiring 17 connected to the circuit board 13. The measurement unit 18 receives the pulse signal from the flow meter 1 and calculates the flow rate per unit time in the fluid passage 3 and the integrated flow rate based on the received content.

  As described above, the flow meter 1 of the present embodiment includes the frequency dividing circuit 16 and the pulse generation circuit 15 provided on the single circuit board 13 and integrated into the flow meter 1. The pulse width and output interval of the generated pulse signal can be increased at a predetermined ratio. Therefore, even when the flow meter 1 is downsized, a pulse signal having an output interval that can be reliably received by the external measurement unit 18 can be generated. Further, by inserting the circuit board 13 into the sensor mounting hole 11 of the meter case 2 and mounting it, the frequency dividing circuit 16 and the pulse generating circuit 15 can be built in the flow meter 1 in a compact manner, and wiring connection from the outside is also possible. Easy.

(Water supply piping structure)
FIG. 9 is an explanatory diagram of a water supply piping structure in a building such as a house. A water supply main 20 to which water is supplied from a water supply source pipe such as a public water pipe is drawn in the underfloor space of the building, and a header 21 is provided in the water supply main 20. The header 21 is formed with branch ports 24 for connecting branch pipes 23 to the respective faucets 22 arranged at a plurality of locations in the building. In this embodiment, the meter case 2 of the flow meter 1 is integrally formed at each branch port 24, and the flow meter 1 is provided in advance at each branch port 24 in the header 21. The wiring 17 connected to the circuit board 13 of each flow meter 1 is routed through the building in a bundled state, and is connected to a measurement unit 18 disposed at an appropriate location in the building.

  In such a water supply piping structure, the flow rate in the branch pipe 23 can be measured by the flow meter 1 only by connecting the branch pipe 23 to each branch port 24, and there is no need to separately install the flow meter 1. Therefore, it is extremely efficient to measure the flow rate to each branch pipe 23. In addition, since wiring between the plurality of flow meters 1 and the measurement unit 18 is routed together in a wiring path from the header 21 to the measurement unit 18, wiring work can be performed efficiently. In addition, maintenance of the flow meter 1 and its wiring can be performed efficiently in one place. Furthermore, in such a configuration, it is not necessary to secure an installation place for the flow meter 1 in the vicinity of each faucet 22, and it is not necessary to perform installation work in a narrow place. Moreover, since the flow meter 1 is not installed in the vicinity of the faucet, the flow meter 1 is not visible to the user and the appearance near the faucet is not deteriorated.

  In FIG. 9, the flow meter 1 is formed integrally with the header 21 in advance, but the branch port provided in the header 21 is configured so that the flow meter 1 can be connected, and the header 21 and the branch pipe 23 are connected. The flow meter 1 may be installed between them. Alternatively, the flow meter 1 may be installed in the middle of the branch pipe 23 near the connection portion with the header 21. Even in such a configuration, the installation and wiring of the flow meter 1 with respect to the plurality of faucets 22 can be performed collectively in one place, so that the installation work can be made more efficient, easier, and more efficient. it can. In addition, the appearance near the faucet can be prevented from being deteriorated, and there is no need to secure an installation space for the flow meter near the faucet.

DESCRIPTION OF SYMBOLS 1 Flowmeter 2 Meter case 2a Step part 3 Fluid passage 3a Passage part 3b Passage part 4 Inlet 5 Outlet 6 Bulkhead part (extension part)
6a Shaft hole 7 Impeller (Rotating magnetic field generating means)
7a Rotating shaft 7b Shaft hole 8 Rectifier 8a Support shaft 8b Cylindrical portion 8c Rectifier plate 8d Rectifier main body portion 9 Magnet piece (rotating magnetic field generating means)
10 Magnetic sensor 11 Sensor mounting hole (board mounting part)
11a Insert 12 Magnetoresistive element (detection element)
13 Circuit board 14 Protruding part 15 Pulse generation circuit 16 Frequency dividing circuit 17 Wiring 18 Measuring unit (upper measuring device)
20 Water supply main pipe 21 Header 22 Water faucet 23 Branch pipe 24 Branch port L Center axis

Claims (5)

A meter case in which a fluid passage is formed;
A rotating magnetic field generating means for generating a rotating magnetic field according to the flow rate of the fluid flowing through the fluid passage;
A detecting element for detecting the rotating magnetic field;
A pulse generation circuit that generates a pulse signal based on the output of the detection element, and a circuit board provided with a frequency dividing circuit that divides the pulse signal by a predetermined frequency dividing ratio,
The meter case is provided with a board mounting portion for inserting the circuit board into the meter case. In claim 1,
The substrate mounting portion is formed in an extending portion extending into the fluid passage from the inner peripheral surface of the meter case adjacent to the rotating magnetic field generating means,
The flow meter is characterized in that an insertion port of the circuit board to the board mounting part is opened in a protruding part protruding from the outer peripheral surface of the meter case. In claim 1 or 2,
The rotating magnetic field generating means is
An axial-flow rotary impeller disposed coaxially in the fluid passage;
And a magnet piece provided at a position deviating from the rotation center of the impeller. A plurality of branch pipes for supplying fluid to a plurality of faucets;
In order to measure the flow rate in each faucet, provided with a flow meter according to any one of claims 1 to 3 provided corresponding to each branch pipe,
The flow meter is integrally formed at a branch port in a header for branching the plurality of branch pipes from a water supply main pipe, or is connected to the header in each branch pipe or in the middle of the pipe near the connection part A water supply piping structure characterized by being attached to the water supply. In claim 4,
For each flow meter, a wiring for connecting the circuit board and a higher-level measuring device is provided,
A water supply piping structure, wherein a plurality of the wires corresponding to the plurality of flow meters are routed together in a wiring route from the header to the higher-level measuring device.

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