water meter

Abstract

This invention provides a water meter that can convert analog meter readings from a direct-reading water meter into digital meter readings with low current consumption, and transmit the digital meter readings to an external source. [Solution] A direct-reading water meter that rotates a digital wheel in conjunction with an impeller that rotates due to the water flow and displays the flow rate on an integrated display unit, comprising: a first flow rate measuring means that measures the flow rate by magnetically detecting the rotation of a magnetic field generator that rotates in conjunction with the rotation of the impeller at the upper part of the upper base plate of the integrated display unit; a second flow rate measuring means that measures the flow rate by optically detecting the rotation of a rotating body that rotates in conjunction with the rotation of the impeller at the upper part of the upper base plate of the integrated display unit; and a communication means that transmits the integrated flow rate value, which is calculated based on the flow rate measured by the first flow rate measuring means and the flow rate measured by the second flow rate measuring means, to the outside in a predetermined message format via wired communication or wireless communication, and receives signals from the outside.

Description

Technical Field

[0001] The present invention relates to a water meter.

Background Art

[0002] A water meter that measures and displays the amount of water used, comprising a nameplate having a display panel for displaying the amount of water used, an impeller that rotates according to the amount of water flowing through the flow path in the water meter, a pilot disposed on the nameplate and rotating in conjunction with the impeller, a magnet fixed so as to face the back surface of the pilot and having a north pole and a south pole, and magnetic sensor means for detecting the magnetic field formed by the magnet via the pilot, and a shielding portion for shielding the magnetic field generated from the magnet in a partial region of the pilot is known (Patent Document 1).

[0003] In a water meter including a lower case having an impeller rotated by inflowing water and an upper case mounted on the lower case and having an indicating unit for measuring and displaying the flow rate based on the rotation of the impeller, the indicating unit has a unit substrate incorporated in the upper case, and the unit substrate has a rotation detection unit for detecting the rotation of the impeller, a control unit for calculating the flow rate based on the rotation speed of the impeller detected by this rotation detection unit, a metering display unit for displaying the flow rate value calculated by this control unit, an external output unit for transmitting the flow rate value to the outside, and a power supply unit for supplying power to the rotation detection unit, the control unit, the metering display unit, and the external output unit, and such a water meter is also known (Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a water meter that can convert analog meter readings in a direct-reading water meter to digital meter readings with low current consumption and transmit the digital meter readings to an external source. [Means for solving the problem]

[0006] To solve the above problem, the water meter described in claim 1 is: A direct-reading water meter that rotates a digital wheel in conjunction with an impeller that rotates due to the water flow, and displays the flow rate on an integrated display unit, A first flow rate measuring means for measuring the flow rate by magnetically detecting the rotation of a magnetic field generator that rotates in conjunction with the rotation of the impeller at the upper part of the upper base plate of the cumulative display unit, A second flow rate measuring means for optically detecting the rotation of a rotating body that rotates in conjunction with the rotation of the impeller at the upper part of the upper base plate of the cumulative display unit and measuring the flow rate, The system includes a communication means that transmits to the outside in a predetermined message format via wired or wireless communication an integrated flow rate value calculated based on the flow rate measured by the first flow rate measuring means and the flow rate measured by the second flow rate measuring means, and also receives signals from the outside. It is characterized by the following:

[0007] The invention described in claim 2 is a water meter described in claim 1, The first flow rate measuring means calculates the flow rate by converting the number of pulses of a pulse signal output from a magnetic detector, which is positioned opposite the magnetic field generator that generates a magnetic field in a horizontal direction intersecting the thickness direction of the magnetic field generator and is separated by 45 degrees in the rotation direction of the magnetic field generator, into a flow rate based on the reduction ratio of the magnetic field generator that reduces the rotation of the impeller to a predetermined reduction ratio using a reduction gear train. The second flow rate measuring means calculates the flow rate based on the number of pulses of a pulse signal output from a photosensor that is erected along the outer circumference of the rotating body and positioned to straddle a light-shielding wall that rotates and moves in conjunction with the rotation of the rotating body. It is characterized by the following:

[0008] The invention described in claim 3 is a water meter described in claim 2, The first flow rate measuring means, when it receives a pulse output from the photosensor, clears the measured flow rate value and resumes flow rate measurement. It is characterized by the following:

[0009] The invention described in claim 4 is a water meter described in claim 2, The second flow rate measuring means starts measuring the flow rate when the flow rate does not exceed a predetermined threshold, the pulse output from the magnetic detector by the first flow rate measuring means continues for a predetermined time or longer, or when the flow rate exceeds a predetermined threshold. It is characterized by the following:

[0010] The invention described in claim 5 is a water meter described in claim 1, The first flow rate measuring means calculates the flow rate based on the number of pulses of a pulse signal output from a magnetic detector positioned opposite the magnetic field generator, which generates a magnetic field in a horizontal direction intersecting the thickness direction of the magnetic field generator, and separated by 45 degrees in the rotational direction of the magnetic field generator. The second flow rate measuring means calculates the flow rate based on the cumulative number of pulses obtained by adding the number of pulses of pulse signals output from a photosensor that is erected along the outer circumference of the rotating body and positioned to straddle a light-shielding wall that rotates along with the rotation of the rotating body. It is characterized by the following:

[0011] The invention described in claim 6 is a water meter described in claim 5, The second flow rate measuring means converts the rotation of the impeller to a predetermined reduction ratio using a reduction gear train into a flow rate per unit pulse based on the reduction ratio of the rotating body. It is characterized by the following:

[0012] The invention described in claim 7 is a water meter described in claim 5, The magnetic field generator is multi-pole magnetized, with 10 or more poles alternately magnetized with south poles and north poles in the direction of rotation. It is characterized by the following.

[0013] The invention according to claim 8 is the water meter according to any one of claims 1 to 7, wherein the communication means transmits the integrated flow value externally as an 8-bit telegram. It is characterized by the following.

Effect of the Invention

[0014] According to the invention described in claim 1, it is possible to convert an analog measurement value in a direct-reading water meter into a digital measurement value with low power consumption and transmit the digital measurement value externally.

[0015] According to the invention described in claim 2, it is possible to measure the flow rate with low power consumption.

[0016] According to the invention described in claim 3, it is possible to perform the flow rate measurement in a minimum flow rate unit of 1 liter. [[ID=二十六]]

[0017] According to the invention described in claim 4, it is possible to switch the flow rate measurement between low flow rate and high flow rate.

[0018] According to the invention described in claim 5, it is possible to convert an analog measurement value in a direct-reading water meter into a digital measurement value.

[0019] According to the invention described in claim 6, it is possible to measure the flow rate at a minimum flow rate unit of 1 liter or less.

[0020] According to the invention described in claim 7, it is possible to measure the flow rate in a minimum flow rate unit of 1 liter.

[0021] According to the invention described in claim 8, it is possible to transmit the digital measurement value externally in a predetermined telegram format. [[ID=四十五]]

Brief Description of the Drawings

[0022] [Figure 1] It is a block diagram showing the overall configuration of the water meter. [Figure 2] This is a schematic cross-sectional view showing an example of the flow rate measuring section of a water meter according to the first embodiment. [Figure 3] (a) is a schematic plan view showing the indicator unit of the water meter according to the first embodiment, (b) is a schematic plan view showing the magnetic field generator, and (c) is a diagram illustrating the arrangement of the magnetic sensor with respect to the magnetic field generator. [Figure 4] (a) is a diagram illustrating the configuration and output signal of a magnetic sensor, and (b) is a diagram showing an example of an output pulse output from a magnetic sensor. [Figure 5] This figure shows an example of output pulses with a 45-degree phase difference, output from two magnetic sensors. [Figure 6] (a) is a schematic plan view showing the rotating body and light-shielding wall of the water meter according to the first embodiment, and (b) is a schematic cross-sectional view AA showing the rotating body and light-shielding wall. [Figure 7] This is a flowchart showing the flow rate measurement operation in the water meter according to the first embodiment. [Figure 8] Figure 8(a) is a schematic plan view showing the indicator unit of a modified water meter, (b) is a schematic plan view showing the rotating body and light-shielding wall of the modified object, and (c) is a schematic cross-sectional view AA showing the rotating body and light-shielding wall of the modified object. [Figure 9] This flowchart shows the flow rate measurement operation in a water meter with a modified configuration. [Figure 10] (a) is a schematic plan view showing the indicator unit 30B of the water meter according to the second embodiment, and (b) is a diagram illustrating the arrangement of the magnetic sensor with respect to the magnetic field generator. [Figure 11] An example of a magnetic field generator related to a modified example is shown. [Figure 12] (a) is a schematic plan view showing the rotating body and light-shielding wall of the water meter according to the second embodiment, and (b) is a schematic cross-sectional view AA showing the rotating body and light-shielding wall. [Modes for carrying out the invention]

[0023] Next, specific examples of embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. Please note that in the following explanation using diagrams, the diagrams are schematic, and the proportions of the dimensions may differ from those of reality. For ease of understanding, diagrams of components other than those necessary for the explanation have been omitted as appropriate.

[0024] "First Embodiment" (1) Overall configuration and operation of the water meter Figure 1 is a block diagram showing the overall configuration of water meters 1 and 1A; Figure 2 is a schematic cross-sectional view showing an example of the flow rate measuring unit 100 of water meter 1 according to this embodiment; Figure 3(a) is a schematic plan view showing the indicator unit 30 of water meter 1 according to this embodiment; (b) is a schematic plan view showing the magnetic field generator 37; (c) is a diagram illustrating the arrangement of the magnetic sensor 41 with respect to the magnetic field generator 37; Figure 4(a) is a diagram illustrating the configuration and output signal of the magnetic sensor 41; (b) is a diagram showing an example of an output pulse output from the magnetic sensor 41; Figure 5 is a diagram showing an example of output pulses with a 45-degree phase difference output from two magnetic sensors 41; Figure 6(a) is a schematic plan view showing the rotating body 38 and light-shielding wall of water meter 1 according to this embodiment; (b) is a schematic cross-sectional view AA showing the rotating body 38 and light-shielding wall. The overall configuration and operation of the water meter 1 according to this embodiment will be described below with reference to the drawings.

[0025] (1.1) Overall configuration of the water meter The water meter 1 according to this embodiment includes a flow rate measurement unit 100, a storage unit 200 that stores information used for various processing, including flow rate measurement data measured by the flow rate measurement unit 100, a communication unit 300 that transmits the integrated flow rate value stored in the storage unit 200 to the outside in a predetermined message format and receives signals from the outside, and a meter control unit 400 that comprehensively controls the operation of the water meter 1. The flow rate measurement unit 100 consists of a first flow rate measurement unit 110 that calculates the flow rate by converting the number of pulses of pulse signals output from two magnetic sensors 41, which are positioned opposite the magnetic field generator 37 and separated by 45 degrees in the rotational direction of the magnetic field generator 37, into a flow rate based on the reduction ratio of the magnetic field generator 37, which reduces the rotation of the impeller 24 to a predetermined reduction ratio using the reduction gear train 35; and a second flow rate measurement unit 120 that calculates the flow rate based on the number of pulses of pulse signals output from a photosensor 42, which is erected along the outer circumference of the rotating body 36 and positioned to straddle a light-shielding wall 38A that rotates along with the rotation of the rotating body 36.

[0026] (1.2) Flow measurement section As shown in Figure 2, the flow rate measuring unit 100 of the water meter 1 has a lower case 10 with an inlet 11 and an outlet 12 formed at both ends, and an inner case 20 is housed inside the lower case 10. The inner case 20 is provided with a plurality of inlet nozzles 21 and outlet nozzles 22, and an impeller support member 23 is erected at the center of the inner bottom of the inner case 20. An impeller 24 having a magnet M1 on the upper part of its shaft is rotatably supported on the impeller support member 23.

[0027] An indicator unit 30 is provided above the impeller 24 via a gasket G1. The indicator unit 30 consists of a register box 31, a lower base plate 32, an upper base plate 33, a magnetic gear 34 with a magnet M2 attached, a reduction gear train 35, a rotation indicator 36, a magnetic field generator 37, a rotating body 38, a digital wheel 39, and a transparent cover 40 attached via an O-ring S1, allowing for direct reading of analog metering values. Furthermore, the magnet M2 of the magnetic gear 34 and the drive-side magnet M1 of the impeller 24 are opposed to each other and magnetically coupled (magnetic coupling), and the rotational force of the impeller 24 is transmitted to the magnetic gear 34.

[0028] (1.2.1) First flow rate measuring unit The rotating indicator 36 is an indicator that the water is in use, and rotates around a rotation axis 36c (not shown) perpendicular to the plane direction of the upper base plate 33 at a speed corresponding to the flow rate of water flowing into the water meter 1. As shown in Figure 3(a), the rotating indicator 36 has a rotating part 36a in the shape of a regular polygonal pyramidal surface (octahedron) where the axis of the rotation axis 36c coincides with its center. Below the rotating part 36a, a magnetic field generator 37 is fixed so as to rotate integrally with the rotating indicator 36. As shown in Figure 3(b), the magnetic field generator 37 is disc-shaped in plan view, magnetized so that the S pole and N pole face adjacent to each other, and generates a magnetic field in the horizontal direction which is the direction of rotation of the magnetic field generator 37 (arrow R) (see arrow in Figure 3(b)). As shown in Figure 3(c), a magnetic sensor 41, which is a magnetic detector that measures the flow rate by magnetically detecting the rotation of the magnetic field generator 37, is disposed on the fixed part facing the upper surface of the magnetic field generator 37. In this embodiment, the fixing part is specifically provided on the lower surface side of the printed circuit board 45 which is fixed below the transparent cover 40. Two magnetic sensors 41 (hereinafter referred to as magnetic sensors 41, 41) are arranged opposite the magnetic field generator 37, at a 45-degree angle on the center line 37c of the magnetic field generator 37.

[0029] As shown in Figure 4(a), the magnetic sensor 41 is an IC-integrated magnetoresistive sensor that integrates four magnetoresistive elements R1, R2, R3, and R4, which are bridge-wired on a grid, onto a waveform shaping circuit (IC) and is integrated into a single chip. As shown in Figure 4(b), when a magnetic field is applied to the magnetic sensor 41, the resistance values ​​of the magnetoresistive elements R1, R2, R3, and R4 change depending on the magnitude and angle of the applied magnetic field, generating a midpoint potential difference (INP-INM). This midpoint potential difference is detected and converted into a pulse wave with a predetermined sensor output (H (High) or L (Low)). The two pulse waves S1 and S2 from the two magnetic sensors 41, 41 are used to measure the rotational state of the impeller 24, such as the direction of rotation, rotational speed, and rotational velocity. In other words, the rotational state of the impeller 24 is intermittently sensed by photoelectrically converting the pulse waves S1 and S2 from each magnetic sensor 41, 41 and outputting a digital signal.

[0030] (Flow rate measurement) As tap water flows in the forward direction, if the impeller 24 rotates once in the forward direction, the rotation indicator 36, which has been reduced to a predetermined reduction ratio by the reduction gear train 35 in conjunction with the impeller 24, rotates, and the magnetic field generator 37, which is fixed below the rotating part 36a of the rotation indicator 36, rotates a predetermined number of times in the forward direction. The forward rotation of the magnetic field generator 37 is detected by two magnetic sensors 41, 41, and as shown in Figure 5(a), the first sensor output S1 and the second sensor output S2 generate pulse signals with a predetermined phase difference (plus 45 degrees in Figure 5(a)). This detection signal is temporarily stored in the memory unit 200. Furthermore, based on the positive phase difference between the first sensor output S1 and the second sensor output S2, it is determined that the rotation direction of the impeller 24 is "forward rotation," and an addition process is performed on the rotation speed of the impeller 24 to sequentially calculate the integrated value of the flow rate.

[0031] On the other hand, if the impeller 24 rotates once in the reverse direction due to the flow of tap water in the reverse direction, then, conversely, the magnetic field generator 37 fixed to the rotating part 36a of the rotation indicator 36 rotates a predetermined number of times in the reverse direction. This reverse movement of the magnetic field generator 37 is detected by two magnetic sensors 41, 41, and as shown in Figure 5(b), the second sensor output S2 and the first sensor output S1 generate pulse signals with a negative phase difference opposite to that during forward rotation (minus 45 degrees, which is 90 degrees different from that during forward rotation). These detection signals are temporarily stored in the memory unit 200.

[0032] Furthermore, based on the phase difference between the first sensor output S1 and the second sensor output S2, it is determined that the rotation direction of the impeller 24 is "reverse," and the integrated value of the flow rate is subtracted. In this way, the rotation direction of the magnetic field generator 37, that is, the rotation direction of the impeller 24, is determined based on the positive or negative phase difference created by the sensor outputs S2 and S1 of the two magnetic sensors 41, 41.

[0033] Here, the flow rate is calculated based on a constant K, which is the flow rate per revolution of the rotation indicator 36 obtained by reducing the rotation of the impeller 24 to a predetermined reduction ratio using the reduction gear train 35. In addition, the pulses output from each magnetic sensor 41, 41 are arranged so that only one pulse is output for every 45-degree rotation of the magnetic generator 37. Therefore, for example, if the constant K is 0.09231 L (liters) per revolution of the rotation indicator 36 (or 1 L for every 10.83 revolutions), then there are 8 output pulses from the magnetic sensors 41, 41 for one revolution of the rotation indicator 36, and the flow rate of tap water (minimum unit) corresponding to one pulse is 0.01153 L (liters). The flow rate measured in this way is stored in the memory unit 200.

[0034] In this manner, two magnetic sensors 41 are arranged opposite the magnetic field generator 37 at a 45-degree angle. If there is a phase difference between the pulses output from the two magnetic sensors 41, 41, it is possible to determine whether the magnetic field generator 37 is rotating forward or backward based on the positive or negative phase difference that occurs depending on whether the magnetic field generator 37 is rotating forward or backward.

[0035] Specifically, for example, when the magnetic field generator 37 is rotating in the forward direction, as shown in Figure 5(a), the state of the second sensor output S2 at the falling edge of the first sensor output S1 is "H (High)", and the state of the second sensor output S2 at the rising edge of the first sensor output S1 is "L (Low)". In contrast, when the magnetic field generator 37 is rotating in the reverse direction, as shown in Figure 5(b), the state of the first sensor output S1 at the falling edge of the second sensor output S2 is "H (High)", and the state of the first sensor output S1 at the rising edge of the second sensor output S2 is "L (Low)". In this way, after determining whether the magnetic field generator 37 is rotating "forward" or "reverse," the determination result is stored in the memory unit 200.

[0036] When counting the integrated flow rate, the impeller 24 is confirmed to be rotating "forward" or "reverse," that is, the magnetic field generator 37 is rotating "forward" or "reverse," and then the flow rate data corresponding to the rotation speed of the magnetic field generator 37 is added to or subtracted from the integrated flow rate. For example, at the rising and falling edges of the pulse of the second sensor output S2, the current integrated flow rate data is counted and stored in the storage unit 200. At that time, the rotation of the magnetic field generator 37 is confirmed to be "forward" or "reverse" before counting up or counting down, and the flow rate (count value) corresponding to one pulse at this time is 0.01153 L (liters).

[0037] (1.2.2) Second flow rate measuring unit A first shaft portion 32a (see Figure 6(b)) is integrally provided on the upper surface of the lower base plate 32, and a first gear 35a (not shown) is rotatably attached to it. A rotating body 38 is provided at the upper end of the first shaft portion 32a so as to rotate integrally with the first gear 35a. In this embodiment, the first gear 35a is one of a reduction gear train 35 arranged so as to rotate integrally with a 1-liter needle (10 liters when the needle completes one rotation), which displays the flow rate used in 1-liter units. Instead of the 1-liter needle, a rotating body 38 is integrally provided.

[0038] As shown in Figure 6(a), a light-shielding wall 38A is erected on the circumference of the rotating body 38, and a slit 38Aa is formed in the light-shielding wall 38A. A photosensor 42 is positioned on the fixed part facing the upper surface of the rotating body 38, and the fixed part is located on the lower side of the printed circuit board 45.

[0039] The photosensor 42 consists of a light-emitting element and a light-receiving element (not shown). As the light-shielding wall 38A rotates in conjunction with the rotation of the rotating body 38, it passes between the light-emitting element and the light-receiving element of the photosensor 42, and each time light is blocked, a pulse signal is output. That is, the rotation of the rotating body 38 (rotation of the impeller 24) is detected by photoelectric conversion of the pulse waveform from the photosensor 42 and outputting a digital signal. In this embodiment, one pulse is output for each rotation of the rotating body 38.

[0040] (Flow rate measurement) Inside the inner case 20, a rotating body 38 rotates in conjunction with an impeller 24 that rotates according to the amount of water flowing. When the light-shielding wall 38A erected on the rotating body 38 rotates, the photosensor 42 detects this and outputs a pulse signal. The rotating body 38 is installed at the upper end of the first shaft portion 32a in place of a 1-liter needle, and the flow rate per rotation of the rotating body 38 is 10 L (liters). On the other hand, since the light-shielding wall 38A is erected on the rotating body 38, the output pulse of the photosensor 42 is 1 pulse for each rotation of the rotating body 38, and the flow rate of tap water (minimum unit) corresponding to 1 pulse is 10 L (liters). The flow rate measured in this way is stored in the memory unit 200.

[0041] (1.3) Communications Department The communication unit 300 has a communication module with wireless communication capabilities, and as shown in Figure 1, it performs wireless communication with power meters (Route A, IoT Route), or, for example, a gateway device or EMS (Energy Management System) equipment connected to Route B, to transmit flow rate measurement data in a predetermined message format. Specifically, the communication unit 300, for example, communicates wirelessly with the HEMS-GW (Home Energy Management System gateway) connected to Route B and transmits the water flow rate integration data retrieved from the meter storage unit 200 in an 8-bit message format. Furthermore, the communication unit 300 communicates wirelessly with power meters and other devices that form a multi-hop mesh network (A route, IoT route) and transmits the water flow rate integration data retrieved from the meter storage unit 200 in an 8-bit message format.

[0042] (1.4) Meter control unit As shown in Figure 1, the meter control unit 400 is a processor that includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and comprehensively controls the water meter 1. The meter control unit 400 stores the water flow rate data measured by the flow rate measurement unit 100 in the storage unit 200 as water flow rate measurement information, associating it with time information. Furthermore, the meter control unit 400 calculates, for example, the cumulative flow rate every 30 minutes and stores this cumulative flow rate information, associated with the measurement date and time, in the storage unit 200. The meter control unit 400 also controls communication with the power meter via the A route and IoT route via the communication unit 300, and controls communication with the gateway device or EMS device connected to the B route. The meter control unit 400 controls the system to send an 8-bit message containing property values, including the measurement date, measurement time, and cumulative flow rate, to a gateway device or EMS device connected to Route B every 24 hours, for example, via the communication unit 300.

[0043] (2) Flow measurement operation Figure 7 is a flowchart showing the flow rate measurement operation in water meter 1. When the meter control unit 400 is activated, the water meter 1 first clears the accumulated flow rate value, reads the year, month, and day from the timer of the processor of the meter control unit 400, and starts processing (S101).

[0044] When water is used, the impeller 24, which is rotatably supported in the inner case 20 of the water meter 1, rotates, and the rotation indicator 36 and the rotating body 38 rotate in conjunction with the rotation of the impeller 24. At this time, the magnetic field generator 37 fixed below the rotating part 36a of the rotation indicator 36 rotates in accordance with the rotation of the rotation indicator 36, and the two magnetic sensors 41, 41 output pulse signals (see Figures 4 and 5). In addition, the photosensor 42 outputs a pulse signal in accordance with the rotation of the rotating body 38. At this time, the rotation indicator 36 rotates 10.83 times per 1 L of flow rate, and the rotating body 38 rotates 1 time per 10 L of flow rate, so until the flow rate reaches 10 L, pulse signals will be output only from the two magnetic sensors 41, 41.

[0045] First, the first flow rate measuring unit 110 reads the input from the magnetic sensors 41, 41 (S102) and determines whether the impeller 24 is rotating based on the pulse signals output from the magnetic sensors 41, 41 (S103). If the impeller 24 is rotating (S103; Yes), it is determined whether it is rotating in the forward direction or not (S104). If the impeller 24 is rotating in the forward direction (S104; Yes), the flow rate is added (S105); if it is rotating in the reverse direction (S104; No), the flow rate is subtracted (S106). The addition or subtraction of the flow rate is performed by storing the flow rate per pulse in the memory unit 200 for each pulse (S107). The determination of whether it is rotating in the forward or reverse direction is made based on the phase difference of the pulse signals output from the magnetic sensors 41, 41. The integration of the flow rate by the first flow rate measuring unit 110 is performed based on the pulse signals from the magnetic sensors 41, 41 until the integrated value reaches 9L (S108; Yes). That is, when the rotation of the magnetic field generator 37 is detected at 97.47 rotations, the integration of the flow rate is stopped (reading of input from the magnetic sensors 41, 41 is stopped) (S109).

[0046] The second flow rate measuring unit 120 reads the input from the photosensor 42 (S201) and determines whether or not there is a pulse signal output from the photosensor 42 (S202). If there is an output of 1 pulse from the photosensor 42 (S202; Yes), the flow rates are added (S203) and stored in the storage unit 200 for integration (S204). Then, in step S107 of the first flow measurement unit 110, the integrated flow value stored in the storage unit 200 is cleared (S205), and the flow measurement by the first flow measurement unit 110 is resumed. Specifically, input from the magnetic sensors 41, 41 is read (S102), and the flow rate is added or subtracted based on the pulse signals output from the magnetic sensors 41, 41.

[0047] The integrated flow values ​​measured by the first flow measurement unit 110 and the second flow measurement unit 120 are then added together in the smallest flow unit of 1L measured by the first flow measurement unit 110 and stored in the storage unit 200.

[0048] Thus, the water meter 1 measures the flow rate in units of 1 liter with low current consumption by first flow rate measuring unit 110, which measures the flow rate in units of 1 liter with a low power consumption magnetic sensor 41 based on the rotation of a magnetic field generator 37 that rotates in conjunction with the impeller 24, and second flow rate measuring unit 120A, which measures the flow rate in units of 10 liters with a photosensor 42 based on the rotation of a rotating body 38 (1-liter needle) that rotates at a low speed after being reduced by a reduction gear train 35, thereby measuring the flow rate in units of 10 liters with low current consumption.

[0049] "Variations" Figure 8(a) is a schematic plan view showing the indicator unit 30A of the modified water meter 1A, (b) is a schematic plan view showing the rotating body and light-shielding wall of the modified object, and (c) is a schematic cross-sectional view AA showing the rotating body and light-shielding wall of the modified object.

[0050] The modified water meter 1A has a second flow rate measuring unit 120A that calculates the flow rate based on the number of pulses per unit time output from a photosensor 42 which is erected along the outer circumference of the rotating body 38 and is positioned to straddle light-shielding walls 38A to 38E that rotate in conjunction with the rotation of the rotating body 38.

[0051] As shown in Figure 8(b), five light-shielding walls 38A to 38E with a circumferential angle of 72 degrees are formed on the circumference of the rotating body 38, and the light-shielding walls 38A to 38E are arranged at equal intervals from each other. Five slits 38Aa to 38E with a circumferential angle of 72 degrees are formed between the five light-shielding walls 38A to 38E. A photosensor 42 is disposed on the fixed part facing the upper surface of the rotating body 38, and the fixed part is provided on the lower side of the printed circuit board 45.

[0052] Inside the inner case 20, a rotating body 38 rotates in conjunction with an impeller 24 that rotates according to the amount of water flowing. When the light-shielding walls 38A to 38E erected on the rotating body 38 rotate, a photosensor 42 detects this and outputs a pulse signal. The rotating body 38 is provided at the upper end of the first shaft portion 32a in place of a 1-liter needle, and the flow rate per rotation of the rotating body 38 is 10 liters. On the other hand, since the rotating body 38 has five light-shielding walls 38A to 38E with a circumferential angle of 72 degrees, the output pulses of the photosensor 42 become 10 pulses for one rotation of the rotating body 38, and the flow rate of tap water (minimum flow rate unit) corresponding to one pulse is 1 liter. The flow rate measured in this way is stored in the memory unit 200.

[0053] Figure 9 is a flowchart showing the flow rate measurement operation in a modified water meter 1A. When the meter control unit 400 is activated, the water meter 1A first clears the accumulated flow rate value, then reads the year, month, and day from the timer of the processor in the meter control unit 400 and starts processing (S301).

[0054] When water is used, the impeller 24, which is rotatably supported in the inner case 20 of the water meter 1A, rotates, and the rotation indicator 36 rotates in conjunction with the rotation of the impeller 24. At this time, the magnetic field generator 37 fixed to the rotating part 36a of the rotation indicator 36 rotates in accordance with the rotation of the rotation indicator 36, and the two magnetic sensors 41, 41 output pulse signals.

[0055] First, the first flow rate measuring unit 110A reads the input from the magnetic sensors 41, 41 (S302) and determines whether the impeller 24 is rotating based on the pulse signals output from the magnetic sensors 41, 41 (S303). If the impeller 24 is rotating (S303; Yes), it is determined whether it is rotating in the forward direction or not (S304). If the impeller 24 is rotating in the forward direction (S304; Yes), the flow rate is added (S305), and if it is rotating in the reverse direction (S304; No), the flow rate is subtracted (S306). Whether it is rotating in the forward or reverse direction is determined based on the phase difference of the pulse signals output from the magnetic sensors 41, 41.

[0056] Next, the added or subtracted values ​​are stored in the storage unit 200 (S307), and it is determined whether the flow rate exceeds a predetermined threshold (Qth) (S308). If the flow rate exceeds the predetermined threshold (Qth) (S308; Yes), the flow rate measurement in the first flow rate measurement unit 110A is stopped, the second flow rate measurement unit 120A is turned on, the input from the photosensor 42 is read (S309), and the flow rate is added based on the pulse signal output from the photosensor 42 (S310).

[0057] If the flow rate is below a predetermined threshold (Qth) (S308; No), it is further determined whether the pulse signals output from the magnetic sensors 41, 41 continue for a predetermined time (Tth) or longer (S311). If it is determined in step S309 that the pulse signals output from the magnetic sensors 41, 41 continue for a predetermined time (Tth) or longer (S311; Yes), the flow rate measurement in the first flow path measurement unit 110A is stopped, the second flow rate measurement unit 120A is turned on, the input from the photosensor 42 is read (S309), and the flow rate is added based on the pulse signal output from the photosensor 42 (S310). Here, the predetermined time (Tth) can be set appropriately considering the power consumption in the water meter 1A, but in this embodiment, for example, it is 3 minutes (min). The predetermined flow rate (Qth) is a so-called medium to high flow rate, specifically 200 L / h to 5000 L / h.

[0058] Next, the added or subtracted values ​​are stored in the memory unit 200 (S312), and the next communication process is executed. On the other hand, if the impeller 24 is not rotating (S303; No), the process returns to step S302.

[0059] As described above, the modified water meter 1A measures the flow rate with low current consumption by first flow rate measuring unit 110A, which measures the flow rate by detecting the rotation of a magnetic field generator 37 that rotates in conjunction with the impeller 24 using a low-power magnetic sensor 41 when the flow rate is low, and second flow rate measuring unit 120A, which measures the flow rate by detecting the rotation of a rotating body 38 (1-liter needle) that rotates at a low speed due to being reduced by a reduction gear train 35 using a photosensor 42 when the flow rate is high. Furthermore, even if a malfunction occurs in either the first flow measurement unit 110A or the second flow measurement unit 120A, it is possible to continue measuring the flow rate in the smallest unit using any of the other flow measurement units.

[0060] "Second Embodiment" (1) Overall configuration of the water meter Figure 10(a) is a schematic plan view showing the indicator unit 30B of the water meter 1B, and (b) is a diagram illustrating the arrangement of the magnetic sensor 41 relative to the magnetic field generator 37. In the water meter 1B according to this embodiment, the configurations and elements other than the configuration of the flow rate measuring unit 100B are the same as those of the water meter 1 in the first embodiment, and the same reference numerals are used for corresponding elements, and redundant explanations of their details are omitted.

[0061] The water meter 1B according to this embodiment includes a flow rate measurement unit 100B, a storage unit 200 that stores information used for various processing, including flow rate measurement data measured by the flow rate measurement unit 100B, and a communication unit 300 that transmits the integrated flow rate value stored in the storage unit 200 to the outside in a predetermined message format and receives signals from the outside.

[0062] (2) Flow rate measurement unit The flow rate measuring unit 100B consists of a first flow rate measuring unit 110B that measures the flow rate by magnetically detecting the rotation of a magnetic field generator 37 that rotates in conjunction with the rotation of the impeller 24 on the upper part of the upper base plate 33 of the indicator unit 30B, and a second flow rate measuring unit 120B that measures the flow rate by optically detecting the rotation of a rotating body 38B that rotates in conjunction with the rotation of the impeller 24 on the upper part of the upper base plate 33 of the indicator unit 30B. (2.1) First flow rate measuring unit A first shaft portion 32a is integrally provided on the upper surface of the lower base plate 32. A first gear 35a (not shown) is rotatably mounted on the first shaft portion 32a, and the first gear 35a constitutes one of the reduction gear trains 35. A magnetic field generator 37 is provided at the upper end of the first shaft portion 32a so as to rotate integrally with the first gear 35a. In this embodiment, the first gear 35a is one of the reduction gear trains 35 arranged so as to rotate integrally with a 1-liter needle (10 liters when the needle completes one rotation) that displays the flow rate used in 1-liter units, and the magnetic field generator 37 is integrally provided in place of the 1-liter needle. Therefore, by detecting the rotation of the magnetic field generator 37, the first flow rate measuring unit 110B can measure the flow rate in units of at least 10 liters or less. Furthermore, the specific structure of the magnetic field generator 37 is not particularly limited, as long as it is configured to rotate integrally with the first gear 35a. The magnetic field generator 37 may be fixed to the 1-liter needle using the 1-liter needle and rotate integrally with the 1-liter needle.

[0063] A magnetic sensor 41, which is a magnetic detector that measures flow rate by magnetically detecting the rotation of the magnetic field generator 37, is provided on the fixed part facing the upper surface of the magnetic field generator 37. Two magnetic sensors 41 are arranged facing the magnetic field generator 37, at a 45-degree angle on the center line 37c of the magnetic field generator 37. The magnetic sensors 41 are the same as the magnetic sensor 41 described in the first embodiment, and their description is omitted.

[0064] (Flow rate measurement) When tap water flows in the forward direction, if the impeller 24 rotates once in the forward direction, the first gear 35a rotates a predetermined number of times in the forward direction in conjunction with the impeller 24, and the magnetic field generator 37, which rotates integrally with the first gear 35a, also rotates in the forward direction. This forward rotation of the magnetic field generator 37 is detected by two magnetic sensors 41, 41, and the first sensor output S1 and the second sensor output S2 generate pulse signals with a predetermined phase difference (plus 45 degrees) (see Figure 5(a)). This detection signal is temporarily stored in the memory unit 200. Furthermore, based on the positive phase difference between the first sensor output S1 and the second sensor output S2, it is determined that the rotation direction of the impeller 24 is "forward rotation," and an addition process is performed on the rotation speed of the impeller 24 to sequentially calculate the integrated value of the flow rate, which is then stored in the memory unit 200.

[0065] On the other hand, if the impeller 24 rotates once in the reverse direction due to the flow of tap water in the reverse direction, the magnetic field generator 37 rotates a predetermined number of times in the reverse direction, contrary to the above. This reverse movement of the magnetic field generator 37 is detected by two magnetic sensors 41, 41, and the second sensor output S2 and the first sensor output S1 have a negative phase difference opposite to that of forward rotation (minus 45 degrees, which is 90 degrees different from that of forward rotation) and generate pulse signals (see Figure 5(b)). This detection signal is temporarily stored in the memory unit 200. Then, based on the phase difference between the first sensor output S1 and the second sensor output S2, it is determined that the rotation direction of the impeller 24 is "reverse", and the integrated value of the flow rate is subtracted. In this way, the rotation direction of the magnetic field generator 37, that is, the rotation direction of the impeller 24, is determined based on the positive or negative phase difference created by the sensor outputs S2, S1 of the two magnetic sensors 41, 41.

[0066] Here, the pulses output from each magnetic sensor 41 are arranged so that only one pulse is output for every 45-degree rotation of the magnetic generator 37. The magnetic generator 37 is integrated with the first gear 35a in place of the 1-liter needle, and since the 1-liter needle indicates 10 L (liters) per rotation, the flow rate (minimum unit) of tap water corresponding to one pulse is set to 1.25 L (liters: 10 L / 8 = 1.25 L).

[0067] "Variations" Figure 11 shows an example of a modified magnetic field generator 37A. The modified magnetic field generator 37A is multi-pole magnetized, with 10 or more poles alternately magnetized with south and north poles in the direction of rotation. For example, if two magnetic sensors 41 are placed 45 degrees apart in the direction of rotation of the magnetic field generator 37A, each magnetic sensor 41 can obtain a pulse output of 10 pulses per rotation of the magnetic field generator 37A. As a result, the 1-liter needle indicates 10 L (liters) per rotation, and the smallest flow rate unit measured by each magnetic sensor 41 is 1 L (liter: 10 L / 10 = 1.0 L).

[0068] In this manner, two magnetic sensors 41 are arranged opposite the magnetic field generator 37 at a 45-degree angle. If there is a phase difference between the pulses output from the two magnetic sensors 41, 41, it becomes possible to determine whether the first rotating body 37 is rotating in the forward or reverse direction based on the positive or negative phase difference that occurs depending on whether the magnetic field generator 37 is rotating in the forward or reverse direction. After determining whether the magnetic field generator 37 is rotating "forward" or "reverse," the determination result is stored in the memory unit 200.

[0069] When counting the integrated flow rate, the impeller 24 is confirmed to be rotating "forward" or "reverse," that is, the magnetic field generator 37 is rotating "forward" or "reverse," and then the flow rate data corresponding to the rotation speed of the magnetic field generator 37 is added to or subtracted from the integrated flow rate. For example, at the rising and falling edges of the pulse of the second sensor output S2, the current integrated flow rate is counted and stored in the memory unit 200. At this time, the rotation of the magnetic field generator 37 is confirmed to be "forward" or "reverse" before counting up or counting down, and the flow rate corresponding to one pulse at this time (minimum flow rate unit) is 1.25 L.

[0070] (2.2) Second flow rate measuring unit Figure 12(a) is a schematic plan view showing the rotating body 38B and the light-shielding wall 381, and (b) is a schematic cross-sectional view AA showing the rotating body 38B and the light-shielding wall 381. The second flow rate measuring unit 120B has a rotating body 38B fixed below the rotating part 36a of the rotating indicator 36, with a light-shielding wall 381 erected around its circumference at a circumferential angle of 180 degrees, so as to rotate together with the rotating indicator 36. A photosensor 42 is positioned on the fixed part above the rotating body 38B. The photosensor 42 detects the rotating light-shielding wall 381 and generates a pulse waveform, thereby measuring the rotational speed of the second gear 45, which is linked to the impeller 24. Specifically, the rotational state of the rotation indicator 36 (the rotational state of the impeller 24) is detected by photoelectric conversion of the pulse waveform from the photosensor 42 and outputting a digital signal.

[0071] (Flow rate measurement) The rotation indicator 36 rotates in conjunction with the impeller 24, which rotates according to the amount of water flowing inside the inner case 20. Since the light-shielding wall 381 erected on the rotating body 38B is formed in a 180-degree range, the photosensor 42 outputs one pulse when the light-shielding wall 381 rotates once. In the second flow rate measurement unit 120B, the flow rate is accumulated based on a constant K, which is converted to the flow rate per rotation of the rotation indicator 36, which is obtained by reducing the rotation of the impeller 24 to a predetermined reduction ratio using the reduction gear train 35. For example, if the constant K is 0.09231 L (liters) per rotation of the rotation indicator 36, then the output pulse of the photosensor 42 is one pulse for one rotation of the rotation indicator 36, and the flow rate of tap water (minimum flow rate unit) corresponding to one pulse is 0.09231 L (liters). The flow rate measured in this way is stored in the storage unit 200.

[0072] (2.3) Storage section The integrated flow rate of tap water measured by the flow rate measurement unit 100B is stored in the storage unit 200 as measurement information associated with the measurement time. In this case, the integrated flow rate measured by the first flow rate measurement unit 110B and stored in the storage unit 200 is integrated with a minimum flow rate unit of 1.25 L (liters), and the integrated flow rate measured by the second flow rate measurement unit 120B is integrated with a minimum unit of 0.09231 L (liters).

[0073] (2.4) Communications Department The integrated flow rate of tap water stored in the memory unit 200 is obtained by adding the integrated flow rate measured by the first flow rate measurement unit 110B in a minimum unit of 1.25 L (liters) and the integrated flow rate measured by the second flow rate measurement unit 120B in a minimum flow rate unit of 0.09231 L (liters), and then transmitting the result to the outside via the communication unit 300 in an 8-bit message format.

[0074] (3) Effects of water meter 1B Thus, the water meter 1B according to this embodiment measures the flow rate by having a first flow rate measuring unit 110B that detects the rotation of a magnetic field generator 37, which rotates at a lower speed than the rotation indicator 36 in conjunction with the rotation of the impeller 24, using a low-power magnetic sensor 41, and a second flow rate measuring unit 120B that detects the rotation of a rotating body 36 (rotation indicator), which rotates in conjunction with the rotation of the impeller 24, using a photosensor 42, thereby enabling the conversion of analog metered values ​​in a direct-reading water meter to digital metered values ​​with low current consumption. Furthermore, the second flow rate measuring unit 120B makes it possible to measure instantaneous flow rate. Furthermore, since the first flow rate measuring unit 110B measures the flow rate by detecting the rotation of the magnetic field generator 37, which is reduced in speed by the reduction gear train 35 and rotates at a low speed, using a magnetic sensor 41, it is possible to reduce the processing capacity of the processor and other components of the control unit 400. [Explanation of symbols]

[0075] 1, 1A, 1B... Water meters 100, 100A, 100B... Flow rate measurement section, 110, 110A, 110B... First flow rate measurement section, 120, 120A, 120B... Second flow rate measurement section 10...Lower case, 20...Inner case, 21...Inlet nozzle, 22...Outlet nozzle, 23...Impeller support member, 24...Impeller, 30...Indicator unit, 31...Register box, 32...Lower base plate, 33...Upper base plate, 34...Magnetic gear, 35...Reduction gear train, 36...Rotation indicator, 36a...Rotating part, 37...Magnetic field generator, 38, 38A, 38B...Rotating body, 39...Digital wheel, 40...Transparent cover, 41...Magnetic sensor, 42...Photosensor 200...Storage section 300... Communications Department 400... Meter Control Unit

Claims

1. A direct-reading water meter that rotates a digital wheel in conjunction with an impeller that rotates due to the water flow, and displays the flow rate on an integrated display unit, A first flow rate measuring means for measuring the flow rate by magnetically detecting the rotation of a magnetic field generator that rotates in conjunction with the rotation of the impeller at the upper part of the upper base plate of the cumulative display unit, A second flow rate measuring means for optically detecting the rotation of a rotating body that rotates in conjunction with the rotation of the impeller at the upper part of the upper base plate of the cumulative display unit and measuring the flow rate, The system includes a communication means that transmits to the outside in a predetermined message format via wired or wireless communication an integrated flow rate value calculated based on the flow rate measured by the first flow rate measuring means and the flow rate measured by the second flow rate measuring means, and also receives signals from the outside. A water meter characterized by the following features.

2. The first flow rate measuring means calculates the flow rate by converting the number of pulses of a pulse signal output from a magnetic detector, which generates a magnetic field in a horizontal direction intersecting the thickness direction of the magnetic field generator and is positioned opposite the magnetic field generator at a 45-degree angle in the rotation direction of the magnetic field generator, into a flow rate based on the reduction ratio of the magnetic field generator, which reduces the rotation of the impeller to a predetermined reduction ratio using a reduction gear train. The second flow rate measuring means calculates the flow rate based on the number of pulses of a pulse signal output from a photosensor that is erected along the outer circumference of the rotating body and positioned to straddle a light-shielding wall that rotates and moves in conjunction with the rotation of the rotating body. The water meter according to feature 1.

3. The first flow rate measuring means, when it receives a pulse output from the photosensor, clears the measured flow rate value and resumes measuring the flow rate. The water meter according to feature 2.

4. The second flow rate measuring means starts measuring the flow rate when the flow rate does not exceed a predetermined threshold, the pulse output from the magnetic detector by the first flow rate measuring means continues for a predetermined time or longer, or when the flow rate exceeds a predetermined threshold. The water meter according to feature 2.

5. The first flow rate measuring means calculates the flow rate based on the number of pulses of a pulse signal output from a magnetic detector positioned opposite the magnetic field generator, which generates a magnetic field in a horizontal direction intersecting the thickness direction of the magnetic field generator, and is separated by 45 degrees in the rotational direction of the magnetic field generator. The second flow rate measuring means calculates the flow rate based on the cumulative number of pulses obtained by adding the number of pulses of pulse signals output from a photosensor that is erected along the outer circumference of the rotating body and positioned to straddle a light-shielding wall that rotates and moves in conjunction with the rotation of the rotating body. The water meter according to feature 1.

6. The second flow rate measuring means converts the rotation of the impeller to a predetermined reduction ratio using a reduction gear train into a flow rate per unit pulse based on the reduction ratio of the rotating body. The water meter according to feature 5.

7. The magnetic field generator is multi-pole magnetized, with 10 or more poles alternately magnetized with south poles and north poles in the direction of rotation. The water meter according to feature 5.

8. The communication means transmits the accumulated flow rate value to the outside as an 8-bit message. A water meter according to any one of claims 1 to 7.

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