JP2006242573A - Water meter - Google Patents

Abstract

[PROBLEMS] To reduce the instrumental error even in a small flow rate range by detecting the rotation of the impeller with a magnetic sensor and integrating it, and can be connected to any meter reading board to which an existing water meter with an analog output function is connected. Provide a good water meter.
A rotating permanent magnet is formed at a position orthogonal to the rotational direction of an impeller 41, magnetic sensors 43 and 44 are disposed on the outer wall surface of the water passage in the vicinity of the rotating permanent magnet, Analog which obtains the analog output which calculated the measurement pulse which electromagnetic induction pulse from magnetic sensor 43 was obtained by rotation detection part 451 in integration calculation part 453, and converted this integration value into the decimal number electric output by one digit And an output unit 46.
[Selection] Figure 1

Description

  The present invention relates to an electronic water meter that has an analog output unit and is used when metering the amount of tap water used by consumers.

  FIG. 9 discloses a usage meter reading device (water usage meter reading board) 9 disclosed in Patent Document 1 and developed for the purpose of accurate measurement without using a high-precision constant current source or the like. It is a figure for demonstrating schematic structure of the water meter electrically connected and used by the cable 10. FIG.

  Here, before explaining the water meter of FIG. 9, the above-described meter reading board 9 will be explained. The meter reading board 9 connects a meter reading device having a constant current source and a usage meter that outputs a resistance value corresponding to the usage amount of water supply or the like through a signal line, and supplies current from the constant current source to the usage meter. The metering of the usage amount is performed based on the metering voltage that appears according to the resistance value of the usage meter at the time, and has the following configuration.

  In other words, a reference resistor that generates a reference voltage by supplying a current from a constant current source and a plurality of comparison resistors are connected between the input and output terminals of the operational amplifier, and the reference voltage can be varied by selecting and controlling these comparison resistors. A differential amplifier circuit that amplifies and outputs as a comparison voltage, a comparator that compares the meter reading voltage and the comparison voltage, and a comparison resistor of the differential amplifier circuit is selectively controlled according to the comparison result by the comparator. And a meter-reading control unit that calculates the amount of use from a variable amplification degree when the comparison voltage is variably amplified to a voltage value corresponding to the meter-reading voltage.

    By providing such means, the detection voltage vk generated when the constant current i flows through the resistance of the water meter is compared with the comparison voltage vh obtained by variably amplifying the reference voltage vh. Therefore, even if the constant current i of the constant current value 11 fluctuates, the reference voltage fluctuates in accordance with the fluctuation, and thus the constant voltage i. Current fluctuations can be offset. Therefore, even if the constant current source is not of high accuracy, it is possible to calculate an accurate usage amount, and furthermore, the usage amount is obtained from the comparison result between the meter reading voltage vk and the comparison voltage by the water meter, so the A / D conversion circuit Is no longer necessary, the error in the A / D conversion circuit is eliminated, and the function in the meter reading control unit is simplified.

    Next, a water meter connected to the meter reading board 9 described above will be described with reference to FIG. 9. This water meter has an analog output unit for voltage conversion or current conversion.

  In FIG. 9, the driving permanent magnet 3 is rotated by the rotation of the lower gear train 2 that is disposed in the water pipe and is in contact with the upper end of the rotating shaft of the impeller 1 that rotates in proportion to the amount of tap water used. . When the passive permanent magnet 4 rotates in accordance with the rotation of the driving permanent magnet 3, the upper gear train 5 attached to the passive permanent magnet 4 rotates, and the rotation register 6 is moved to perform integration. The decimal analog output is switched according to the position of the contact 7 attached to the rotation register 6 and the contact 7 of the substrate 8. The passive permanent magnet 4, the upper gear train 5, the rotation register 6, the contact 7, and the substrate 8 are disposed in a container that is isolated from the channel through which tap water flows.

  In addition to the patent documents described above, there are the following as references for the present invention. That is, Patent Document 2 describes an electronic water meter that eliminates a sampling system measurement error.

Patent Document 3 describes a flow meter including a pulse width shaping unit having a predetermined width from the output of the pulse output unit.
Japanese Examined Patent Publication No. 7-97439 JP 2000-74709 A Japanese Unexamined Patent Publication No. 7-83725

In the water meter having the analog output function shown in FIG. 9, the rotation of the impeller 1 is caused by rotating the rotation register 6 by transmission of a magnet coupling including the gear trains 2 and 5 and the permanent magnets 3 and 4. In order to integrate, a large force is required to rotate the impeller 1, and the instrumental error becomes large in a small flow rate region where the flow of water is small.
Specifically, it is compatible with the instrumental error range (± 5.0%) of the small flow rate range (2-8% of the standard flow rate) specified by the current measurement law, but will be constructed in the near future. There is a problem that it cannot cope with the instrumental error range (± 5.0%) in the small flow rate range (1.6 to 2.56% of the standard flow rate) of the new measurement method (JIS conversion).

   In order to solve the above-mentioned problem, the present invention is connected to a water meter having an analog output function that can reduce the instrumental error even in a small flow rate range by detecting and integrating the rotation of the impeller with a magnetic sensor. The purpose is to provide a water meter that can be connected to any meter reading board.

In order to achieve the object, an invention corresponding to claim 1 is provided in a water passage through which tap water flows, and an impeller that rotates in proportion to the water flow, and a rotation direction of the impeller of the impeller, A rotating permanent magnet having N and S poles mounted at orthogonal positions, and an outer wall surface of the water passage, disposed in proximity to the rotating permanent magnet, and according to the rotation of the rotating permanent magnet A magnetic sensor that outputs an electromagnetic induction pulse; and a rotation detector that outputs an electromagnetic induction pulse from the magnetic sensor;
When combined with an integration calculation unit that sequentially integrates electromagnetic induction pulses from the rotation detection unit and a meter reading board that is used when metering the amount of water used, the integration value of the integration calculation unit is 10 by one digit. It is a water meter provided with the analog output part which obtains the analog output converted into the decimal electrical output.

  ADVANTAGE OF THE INVENTION According to this invention, the water meter which can be connected to the meter-reading panel to which the instrumental difference can be made small also in the small flow area and the existing water meter with an analog output function is connected can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. An impeller 41 that is rotatably disposed in a water passage through which tap water flows and rotates in proportion to the water flow, and the blades of the impeller 41. Specifically, it is attached to the upper end portion of the rotation shaft 411 of the impeller 41 at a position orthogonal to the rotation direction of the wheel 41, and rotates so that the N pole and the S pole are joined as viewed from above as shown in FIG. A permanent magnet 42 is formed. Further, the outer wall surface of the water passage is disposed in the vicinity of the rotating permanent magnet 42 and outputs an electromagnetic induction pulse according to the rotation of the rotating permanent magnet 42, and at a constant angle as shown in FIG. For example, the first and second magnetic sensors 43 and 44 disposed at the same plane with 135 degrees, a rotation detecting unit 451 that outputs an electromagnetic induction pulse from the magnetic sensor 43, and an electromagnetic induction pulse of the magnetic sensor 44 A forward / reverse determination unit 452 that determines whether the rotation of the impeller 41 is forward or reverse according to the output state, and a forward / reverse signal output from the forward / reverse determination unit 452 and a measurement pulse from the rotation detection unit 451, and a rotation detection unit 451 The integration calculation unit 453 for sequentially integrating the electromagnetic induction pulses is provided. Further, when combined with the meter reading board 47 used when metering the amount of water used, an analog output unit for obtaining an analog output obtained by converting the integrated value of the integrated calculation unit 453 into an electrical output of decimal numbers one by one. 46.

  FIG. 2 is a diagram for explaining the configuration of the analog output unit 46, which outputs a measured value of the amount used for each digit as a resistance value (10 resistors R0). To R9 are connected in series, and the connection points 0 to 9 of the resistors R0 to R9 and the common contact c are connected to output a resistance value corresponding to the measured amount of use.

  In addition, although the water meter 1 shown in FIG. 1 has a structure for one digit, it is actually provided with a resistance for three to four digits, or a constant current value is varied for each digit. The switching system is provided. Therefore, in any digit, a resistance value corresponding to the amount used is obtained, and a constant current is supplied to this resistor to convert it into a meter reading voltage.

  Here, the effect of this embodiment is demonstrated with reference to FIGS. When the tap water flows into the tap water passage, the impeller 1 rotates in response to this, and the rotating permanent magnet 42 fixed to the rotating shaft of the impeller 1 rotates at the same time as the impeller 1. Are detected by the magnetic sensors 43 and 44, and electromagnetic induction pulses having different phases are generated from the magnetic sensors 43 and 44, as shown in FIG. 4, and these are transmitted via the rotation detection unit 451 and the forward / reverse determination unit 452. And output (output) to the integration calculation unit 45.

  Here, when the flow direction of tap water is correct from the state of the pulse waveform generated by the magnetic sensors 43 and 44, the forward / reverse determination unit 452 is, for example, as shown in FIG. It is clear that the water meter is correctly installed.

  On the other hand, as shown in FIG. 7, the rotation detection unit 451 starts to generate a clock amount pulse that has fallen the sensor 43 when the rotation of the rotating permanent magnet 42 starts, and the clock amount that has fallen the sensor 44. After the generation of the pulse is completed, the measurement pulse starts to be generated in a state where the sensor 44 has risen, the generation of the clock amount pulse which has fallen the sensor 43 is ended, and so on.

The integration calculation unit 453 adds or subtracts the measurement pulse from the rotation detection unit 451 to the previous value based on the normal / reverse determination result by the normal / reverse determination unit 452. Specifically, it is incremented when the forward / reverse determination unit 452 determines positive, and is negative when it is determined reverse.
According to the embodiment described above, the rotation of the impeller 41 is detected by the rotating permanent magnet 42 attached to the impeller 41 and the magnetic sensors 43 and 44, and the detected values are integrated. The instrumental error can be reduced in the small flow area of the water meter having the section 46, and it becomes possible to cope with a new measuring method to be implemented in the near future. Further, since the analog output unit 46 is provided on the output side of the integration calculation unit 453, an existing meter reading board 47 in which a water meter having a conventional analog output unit (analog output function unit) is installed in a consumer is installed. It can be installed by replacing only the water meter without replacement.

(Modification)
In the above-described embodiment, the analog output unit 46 used when the meter reading board 47 reads the value in the integration calculation unit 453 that integrates the water measurement pulse is converted into the voltage output shown in FIG. 2 as an example. However, this can be implemented in the same manner even if it is a system that converts this into a current output as shown in FIG.

  In the above-described embodiment, the example in which the water meter includes the forward / reverse determination unit 452 has been described as an example. However, when the direction of tap water flow is constant depending on the usage, usage state, etc., the forward / reverse determination unit Even if 452 is not provided, the same effects as those of the above-described embodiment can be obtained.

The schematic block diagram which shows the water meter and meter reading board which have the analog output part of this invention. The schematic block diagram which shows an example of the analog output part of FIG. The figure for demonstrating the relationship between the rotation permanent magnet of FIG. 1, and a magnetic sensor. The figure for demonstrating the relationship between the rotation permanent magnet of FIG. 1, a magnetic sensor, and a calculation part. The figure for demonstrating the relationship between the rotation permanent magnet of FIG. 1, a magnetic sensor, and a normal / reverse determination part. The figure for demonstrating the relationship between the rotation permanent magnet of FIG. 1, a magnetic sensor, and a normal / reverse determination part. The figure for demonstrating the relationship between the rotation permanent magnet of FIG. 1, a magnetic sensor, and a rotation detection part. The schematic block diagram which shows the other example of the analog output part of FIG. The schematic diagram which shows the water meter and meter-reading board which have the conventional analog output part.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Impeller, 2 ... Lower gear train, 3 ... Drive permanent magnet, 4 ... Passive permanent magnet, 5 ... Upper gear train, 6 ... Rotation register, 7 ... Contact, 8 ... Substrate, 9 ... Usage meter reading device (Meter reading board) 10 ... cable, 41 ... impeller, 42 ... rotating permanent magnet, 43 ... magnetic sensor, 44 ... magnetic sensor, 45 ... integration calculation part, 46 ... analog output part, 47 ... meter reading board, 411 ... rotation Axis, 451... Rotation detection unit, 452... Normal / reverse determination unit, 453.

Claims (4)

An impeller disposed in a water passage through which tap water flows, and rotating in proportion to the water flow;
A rotating permanent magnet mounted at a position perpendicular to the rotational direction of the impeller of the impeller and having an N pole and an S pole;
A magnetic sensor that is an outer wall surface of the water passage and is disposed in proximity to the rotating permanent magnet, and outputs an electromagnetic induction pulse according to the rotation of the rotating permanent magnet;
A rotation detector that outputs an electromagnetic induction pulse from the magnetic sensor;
An integration calculation unit for sequentially integrating electromagnetic induction pulses from the rotation detection unit;
An analog output unit for obtaining an analog output obtained by converting the integrated value of the integrated calculation unit into a decimal electrical output by one digit when combined with a meter reading board used for metering the amount of water used;
Water meter equipped with. Add a forward / reverse determination unit for determining forward / reverse rotation of the impeller according to the output state of the electromagnetic induction pulse of the magnetic sensor unit,
The water meter according to claim 1, wherein the integration calculation unit receives and calculates the normal / reverse signal output from the normal / reverse determination unit and the measurement pulse from the rotation detection unit.   3. The water meter according to claim 1, wherein the analog output unit has a value obtained by converting the integrated value into a decimal current output by one digit when combined with the meter reading board.   3. The water meter according to claim 1, wherein the analog output unit has a value obtained by converting the integrated value into a decimal voltage output by one digit when combined with the meter reading board.

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