JP2008164544A - Water meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water meter dispensing with an expensive CPU, capable of holding integrated value data of a service water consumption at an emergency situation time, preventing a measurement error caused by a back flow of service water, and reducing current consumption of a battery. <P>SOLUTION: This water meter 11 has an impeller 21 whose rotational frequency is increased/decreased according to a flow rate of the service water, and transfers the rotational frequency of the impeller 21 through a plurality of gears 33 or the like, and integrates and displays the rotational frequency. A rotating member 34 for metering the service water is provided on a shaft part 32 of the gear 33, rotatably in a body with the gear 33, and a portion 35 to be detected of the rotating member 34 is detected by two optical sensors 36, 37, to thereby sense the rotation state of the impeller 21. A microcomputer 40 having a normal/reverse rotation determination part 41, an operation-integration circuit part 42, a storage part 43 and a communication function part 44 is connected to the optical sensors 36, 37, to thereby perform addition/subtraction processing to/from an integrated value according to normal/reverse rotation of the impeller 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a water meter, and more particularly to a water meter that can automatically measure the flow rate of tap water.

  Conventionally, as shown in FIG. 14, this kind of water meter 1 is generally provided with an impeller 4 in which a two-pole magnetized type magnet 3 is fixed to an upper head in a measuring portion 2 so as to be rotatable. The impeller 4 rotates according to the flow rate of tap water passing through the measuring chamber 2, and the rotational speed of the magnet 3 is detected by a magnetic sensor (flow rate sensor) 5. The signals detected by the magnetic sensor 5 are calculated and integrated by an internal circuit of a microcomputer (CPU) mounted on the printed circuit board 6. Next, the processing result is stored and held in a storage unit (not shown) as integrated value data, and the integrated value data is sent to the liquid crystal display unit 7 for display. In the figure, 8 is a register box, 9 is an instruction window, and 10 is a battery.

An electronic water meter having a communication function is provided with a communication function for transmitting the integrated value data by serial communication so that data can be transmitted to an external automatic meter reading device or the like. Thereby, the integrated value which is meter-reading data can be easily known even from a place away from the electronic water meter (see, for example, FIG. 1 of Patent Document 1 as a related water meter structure example).
Japanese Patent Laid-Open No. 2002-081975.

  The conventional electronic water meter is configured to display an integrated value calculated by a microcomputer on a liquid crystal display. However, since the electronic water meter is electronic, the storage unit is destroyed by a lightning strike or the like, or the microcomputer When the battery that supplies power to the battery runs out of life, it may fall into a measurement failure state. In such an emergency situation, in the worst case, the integrated value data cannot be held.

  Moreover, although the electronic water meter senses the rotation speed of the magnet attached to the impeller by a magnetic sensor, it has been found that this magnet sensing method is easily affected by external magnetism. Therefore, in order to obtain a stable measurement result that is not easily affected by magnetism, it is necessary to adopt a method that does not use a magnetic sensor.

  Furthermore, since the conventional electronic water meter directly counts the high-speed rotation of the impeller, it requires a high-performance CPU equipped with a large number of electronic components, consumes a large amount of current, and requires a large capacity battery. Overall, the structure becomes complicated and the cost increases.

  The electronic water meter has many functions in addition to measuring the amount of water used. For example, the electronic water meter is configured to measure the instantaneous flow rate flowing through the water pipe and transmit the measurement result to an external automatic meter reading device. Has been. However, since this instantaneous flow rate is also measured electronically, it has the disadvantage that it is easily affected by magnetism as described above and it is difficult to obtain a stable measurement result.

  Therefore, in order to reduce the cost by eliminating the need for expensive CPUs and large-capacity batteries without being affected by external magnetism, which can stably hold the integrated value data of tap water in an emergency situation. Therefore, a technical problem to be solved arises, and the present invention aims to solve this problem.

  The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 has an impeller whose number of rotations increases or decreases in accordance with the flow rate of tap water in the measuring section, and the blade In a water meter that transmits the rotational speed of a vehicle through a plurality of gears and displays an integrated value of the rotational speeds, a circumferential portion is provided on a shaft portion of the gear that constitutes one of the plurality of gears. A rotating member for measuring tap water having a detected part such as a light shielding part is provided so as to rotate integrally with the gear, and the detected part is detected to rotate the rotation direction, the rotational speed, etc. of the gear. Two optical sensors for measuring tap water for sensing the state, and a microcomputer connected to the optical sensor, the microcomputer determines whether the impeller is normal or reverse. And added to the integrated value when the impeller is rotating forward. An arithmetic / integration circuit unit that performs processing and performs a subtraction process on the integrated value when the impeller is reversely rotated, a storage unit that stores the integrated value data, an external automatic metering device, etc. A water meter is provided that includes a communication function unit that transmits data to the network.

  According to this configuration, the gear rotates along with the rotation of the impeller, and the rotating member for measuring tap water provided on the shaft portion of the gear also rotates. Since this rotating member is provided with a detected portion, for example, a light shielding portion, a light reflecting portion, or a slit, the detected portion is detected by two optical sensors for measuring tap water, and the detection signal Is sent to the forward / reverse determination unit and the calculation / integration circuit unit of the microcomputer. Furthermore, the forward / reverse rotation determination unit determines whether the rotation direction of the impeller is forward rotation or reverse rotation based on the detection signal. Further, the calculation / integration circuit unit adds the integrated value of the rotational speed when the impeller rotates in the forward direction, and subtracts the integrated value when the impeller rotates in the reverse direction.

  The added or subtracted integrated value data is stored in the storage unit of the microcomputer. Also, the integrated value data stored in the storage unit is transmitted to an automatic meter reading device or the like in response to an external request. Since the signal processing system of the present invention optically detects the rotation speed of the impeller, it is not affected by external magnetism (magnetic force).

  According to a second aspect of the present invention, there is provided a water meter according to the first aspect, wherein sensing by the optical sensor is performed intermittently.

  According to this configuration, the optical sensor is intermittently driven every period set according to the rotational speed of the impeller and the like. Therefore, the drive current from the power supply battery to the photosensor (including the peripheral circuit) is supplied only for a necessary time, and the drive current is not supplied for an unnecessary time.

  According to a third aspect of the present invention, the two optical sensors are arranged with a predetermined interval in the rotation direction of the tap water metering rotation member, and the forward / reverse determination unit includes two optical sensors. The water meter according to claim 1, wherein the water meter is configured to determine the rotational direction of the impeller based on a phase difference between sensor outputs to be sent out.

  According to this configuration, the two optical sensors have a predetermined distance from each other in the rotation direction of the rotating member. Therefore, the sensor outputs S1 and S2 which are detection signals of the two optical sensors are rotated. A positive or negative phase difference corresponding to the normal rotation or reverse rotation of the member is input to the normal / reverse rotation determination unit. Thus, the forward / reverse determination unit determines the rotation direction of the impeller based on the positive or negative phase difference generated by the two sensor outputs S1 and S2. For example, when the state of the sensor output S1 at the rising edge of the sensor output S2 is “H (high)”, it is determined to be “forward rotation” (see FIG. 10). On the contrary, when the state of the sensor output S1 at the rising edge of the sensor output S2 is “L”, it is determined to be “reverse” (see FIG. 11).

  The invention according to claim 4 has an impeller whose rotational speed increases or decreases in accordance with the flow rate of tap water in the measuring unit, and transmits the rotational speed of the impeller through a plurality of gears. In the water meter that displays the integrated value of the shaft, the shaft portion of the gear that rotates in conjunction with the impeller (the shaft portion for instantaneous flow rate measurement) has a detected portion such as a light shielding portion on the circumference. A rotating member for instantaneous flow rate measurement is provided so as to rotate integrally with the gear, and a single optical sensor for instantaneous flow rate measurement for detecting the detected portion and sensing the number of rotations of the gear is provided, and A microcomputer is connected to the optical sensor, and the microcomputer is configured to measure an instantaneous flow rate based on the rotational speed of the gear detected by the optical sensor; It has a communication function unit that sends it to a meter reading device To provide a water meter made.

  According to this configuration, the gear rotates along with the rotation of the impeller, and the instantaneous flow rate measuring rotation member provided on the shaft portion of the gear also rotates. Since this rotating member is provided with a detected portion, the detected portion is detected by an optical sensor for measuring an instantaneous flow rate, and the detection signal is sent to an arithmetic circuit portion of a microcomputer to detect the detected gear. The instantaneous flow rate is measured based on the rotation speed. The measured instantaneous flow rate is transmitted to an external automatic meter reading device or the like by the communication function unit.

  The invention according to claim 5 provides the water meter according to claim 4, wherein the measurement of the instantaneous flow rate is performed only when there is a request by communication from the outside.

  According to this configuration, the measurement of the instantaneous flow rate is started only when the instantaneous flow rate measurement is requested by communication from the outside, and the measurement of the instantaneous flow rate is not performed otherwise.

  Since the invention described in claim 1 is a gear-linked transmission system, even if it becomes impossible to measure due to lightning strike or battery life expiration, the integrated value can be stored as it is, and the main meter functions excluding the external data output function Can also be maintained well. In addition, since the rotational state of the impeller is optically sensed, accurate measurement results can be stably obtained without being affected by the external magnetic force.

  Furthermore, when the impeller reverses, the integrated value is subtracted and corrected, so that erroneous measurement due to backflow of tap water can be prevented, and the amount of water used can always be accurately measured. Further, since the rotational direction of the impeller can be detected by two optical sensors, the number of optical sensors is minimized, and the rotational direction of the impeller can be accurately detected while the structure is simple. Furthermore, since the rotation of the gear that has been decelerated is counted instead of the high-speed rotation of the impeller, a high-performance CPU is not required, current consumption is reduced, and a small-capacity battery can be used.

  According to the second aspect of the present invention, since it is only necessary to intermittently supply the drive current to the optical sensor, in addition to the effect of the first aspect of the invention, the current consumption is reduced by the amount that unnecessary current supply is omitted The amount can be reduced.

  Since the invention according to claim 3 can detect the rotation direction of the impeller based on the phase difference between the detection signals of the two optical sensors, in addition to the effect of the invention according to claim 1, a forward / reverse determination unit, etc. The circuit configuration can be further simplified and the rotational direction of the impeller can be accurately determined.

  The invention according to claim 4 can measure the instantaneous flow rate based on the data detected by one optical sensor, so that the structure is simple and can be sent to an external automatic meter reading device or the like as needed. Also, it is not affected by external magnetic force.

  Since the invention according to claim 5 measures the instantaneous flow rate only when there is a request for instantaneous flow rate measurement through communication from an external meter reading device or the like, in addition to the effect of the invention according to claim 4, Extra electricity consumption can be saved.

  The present invention is capable of stably holding integrated value data of tap water in an emergency, is less susceptible to external magnetism, and eliminates the use of expensive CPUs and large-capacity batteries, thereby reducing costs. In order to achieve the object, the measuring unit has an impeller whose rotational speed increases or decreases in accordance with the flow rate of tap water, and transmits the rotational speed of the impeller through a plurality of gears, and integrates the rotational speed. In the water meter configured to display a value, a rotating member for measuring tap water having a detected portion such as a light shielding portion on a circumference is provided on a shaft portion of a gear constituting any one of the plurality of gears. Two tap water metering optical sensors for detecting the detected portion and sensing the rotation state, such as the rotation direction and the rotation speed of the gear, are provided so as to rotate integrally with the gear; and A microcomputer connected to the optical sensor, The black computer includes a forward / reverse determination unit that determines forward or reverse rotation of the impeller, an addition process to the integrated value when the impeller is forward rotating, and the integrated value when the impeller is reversely rotated. This is realized by including an arithmetic / integration circuit unit that performs subtraction processing, a storage unit that stores the integrated value data, and a communication function unit that transmits the integrated value data to an external automatic meter reading device or the like.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a longitudinal sectional view showing a water meter according to this embodiment, and FIG. 2 is a plan view of the water meter. In FIG. 1, 11 is a water meter, which includes a lower case 12 and an upper case 13 that are assembled together.

  The upper surface opening of the upper case 13 is covered with a transparent cover 17 for the display mechanism. An impeller 21 is rotatably provided via a pivot 20 in a passage (measurement chamber) 19 formed in the lower case 12. Therefore, when tap water flows through the passage 19, the rotational speed of the impeller 21 increases or decreases according to the flow rate of the road water. A four-pole magnetized drive-side magnet 24 is attached to the upper head of the impeller 21, and a driven-side magnet 25 is rotatably magnetically coupled to the upper side of the drive-side magnet 24. A center gear 26 is provided on the driven side magnet 25 so as to be integrally rotatable.

  Accordingly, when the impeller 21 rotates due to the flow of tap water, the rotational force of the impeller 21 is transmitted to the driven magnet 25 by the magnetic coupling action, so that the center gear 26 rotates together with the driven magnet 25. The center gear 26 can also be directly connected so as to rotate integrally with the impeller 21. Reference numeral 22 denotes a display unit of the numeral wheel 30 described later, 27 denotes a register box, 28 denotes an O-ring, and 29 denotes a strainer.

  A number wheel 30 is disposed above the register box 27, and a speed reduction gear train (not shown) composed of a plurality of gears is provided between the number wheel 30 and the center gear 26 so as to be able to transmit driving. ing. The number wheel 30 is rotated when the rotational force of the impeller 21 is transmitted to the number wheel 30 through the reduction gear train or the like. The integrated value of the rotational speed of the number wheel 30 corresponds to the integrated value of the rotational speed of the impeller 21, and the integrated value is displayed on the display unit 22. A first shaft portion (a tap water measuring shaft portion) 32 is integrally provided on the upper surface of the lower base plate 31 shown in FIG. As shown in FIG. 3B, a first gear 33 is rotatably attached to the first shaft portion 32, and the first gear 33 constitutes one of a reduction gear train. Further, a rotating member 34 for measuring tap water is provided at the upper end portion of the first shaft portion 32 so as to be able to rotate integrally with the first gear 33. The tap water metering rotation member 34 is not particularly limited as long as it is configured to rotate integrally with the first gear 33.

  As shown in FIGS. 3A to 3C, one semicircular light shielding portion (projection piece) 35 that is a detected portion is formed on the outer peripheral edge of the upper surface of the tap water metering rotating member 34. Has been. Further, as shown in FIG. 4, a first optical sensor 36 and a second optical sensor 37, which are photo-interrupter type detectors, are arranged on the fixed portion facing the upper surface of the tap water metering rotating member 34. It is installed. In this embodiment, specifically, the fixing portion is provided on the lower surface side of the printed circuit board 38 fixed below the transparent cover 17. A battery 39 is provided on the upper surface side of the printed circuit board 38.

  The first optical sensor 36 and the second optical sensor 37 are arranged so as to have a phase difference of 90 degrees in the normal rotation direction of the tap water metering rotation member 34. Each of the optical sensors 36 and 37 includes a light emitting element and a light receiving element, and the optical sensors 36 and 37 detect the semicircular arc light shielding portion 35 when the tap water measuring rotary member 34 rotates to generate a pulse wave. . Then, the rotational state of the impeller 21 such as the rotational direction, the rotational speed, and the rotational speed is measured by the two pulse waves. That is, the rotational state of the impeller 21 is intermittently sensed by photoelectrically converting the pulse waves from the individual optical sensors 36 and 37 and then outputting a digital signal.

  As shown in FIG. 5, the printed circuit board 38 is equipped with a microcomputer (CPU) 40 as control means, and the microcomputer 40 is connected with the optical sensors 36 and 37. The microcomputer 40 performs a forward / reverse determination unit 41 that determines forward or reverse rotation of the impeller 21, performs an addition process on the integrated value (meter reading data) of water consumption when the impeller 21 is forward rotation, and An arithmetic / integration circuit unit 42 that performs a subtraction process on the integrated value when the impeller 21 rotates in reverse, a storage unit 43 that stores the integrated value data, and transmits the integrated value data to an external automatic meter reading device or the like. And a communication function unit 44.

  In the present embodiment, the forward rotation or the reverse rotation of the impeller 21 is determined based on the phase difference generated in the detection signals from both the second optical sensors 36 and 37. The rotation direction of the impeller 21 when tap water passes in the forward direction (downstream direction) is defined as “forward rotation”, and the reverse rotation direction is defined as “reverse rotation”. As described above, the forward / reverse determination unit 41 receives the detection signals from the first optical sensor 36 and the second optical sensor 37, and generates a phase difference (positive or negative phase difference 90 degrees) generated by the two detection signals. ) To determine the rotational direction of the impeller 21. In addition, the arithmetic / integration circuit unit 42 performs addition or subtraction processing on the rotation speed of the impeller 21 according to the determination result of the forward / reverse rotation determination unit 41 to sequentially calculate the integrated value of water usage. Further, the storage unit 43 temporarily holds detection signals from the optical sensors 36 and 37 and stores data such as an integrated value calculated by the arithmetic / integration circuit unit 42. The stored data held in the storage unit 43 is transmitted to an external automatic meter reading device or the like by the communication function unit 44 in response to a request from the outside.

  The water meter 11 of this embodiment can also optically measure the instantaneous flow rate. As shown in FIGS. 6 (a) to 6 (c), a specific configuration for measuring the instantaneous flow rate is provided for measuring the instantaneous flow rate on the shaft portion 46 of the second gear 45 that rotates in conjunction with the impeller 21. A rotating member 47 is provided so as to rotate integrally with the second gear 45. Four arc-shaped light shielding portions (projection pieces) 48a to 48d having a circumferential angle of 45 degrees, which are detected portions, are formed on the circumference of the rotating member 47 for instantaneous flow rate measurement, and the arc-shaped light shielding portions. 48a to 48d are arranged at equal intervals.

  Four slits 49a to 49d having a circumferential angle of 45 degrees are formed between the four arc-shaped light shielding portions 48a to 48d. Further, as shown in FIG. 8, a third optical sensor 50 for instantaneous flow rate measurement is disposed on the fixed portion facing the upper surface of the rotating member 47 for instantaneous flow rate measurement, and the fixed portion is the printed circuit board. 38 is provided on the lower surface side. The third optical sensor 50 includes a light emitting element and a light receiving element. The third optical sensor 50 detects the rotating arc-shaped light shielding portions 48a to 48d and generates a pulse waveform, thereby interlocking with the impeller 21. The rotational speed of the second gear 45 is measured. That is, the rotational state of the second gear 45 (the rotational state of the impeller 21) is detected by photoelectrically converting the pulse waveform from the third optical sensor 50 and then outputting a digital signal.

  As shown in FIG. 7, the third photosensor 50 is connected to the microcomputer 40. The microcomputer 40 includes an arithmetic circuit unit 51 that measures the instantaneous flow rate based on the rotation speed of the second gear 45 detected by the third optical sensor 50, a storage unit 43 that stores the measurement data, and the like, A communication function unit 44 that transmits measurement data to an external automatic meter reading device and the like, and a control unit 52 that starts measurement of the instantaneous flow rate when there is a request for instantaneous flow rate measurement by communication from the outside.

  Next, in the water meter 11 having the above configuration, calculation / integration processing based on detection signals of the first optical sensor 36 and the second optical sensor 37 will be described in detail. The detection signals of the first optical sensor 36 and the second optical sensor 37 are defined as a first sensor output S1 and a second sensor output S2, respectively. Now, assuming that the impeller 21 rotates once in the forward direction by flowing tap water in the forward direction, the first gear 33 rotates in the forward direction by a predetermined number of rotations in conjunction with the impeller 21.

  As a result, the semicircular arc light shielding portion 35 of the tap water metering rotating member 34 that rotates integrally with the first gear 33 rotates in the forward rotation direction. The forward rotation of the semicircular arc-shaped light shielding portion 35 is detected by the optical sensors 36 and 37. As shown in FIG. 10, the first sensor output S1 and the second sensor output S2 have a predetermined phase difference (illustrated example). Signal is generated with a plus 90 degrees). The detection signal is transmitted to the microcomputer 40 and stored in the storage unit 43. The sensor outputs S1 and S2 are sent to the forward / reverse determination unit 41. Thus, the forward / reverse rotation determination unit 41 determines that the rotation direction of the impeller 21 is “forward rotation” based on the positive phase difference between the two sensor signals shown in FIG. 10 and calculates the determination result. The accumulated value of the amount of tap water used is added by 1 (+1).

  On the other hand, if the impeller 21 rotates once in the reverse direction by flowing the tap water in the reverse direction, the semicircular arc-shaped light shielding portion 35 on the upper surface of the rotating member 34 for measuring tap water is reversed in the reverse direction. It rotates by a predetermined number of rotations. The reverse rotation of the semicircular arc-shaped light shielding portion 35 is detected by the optical sensors 36 and 37, and as shown in FIG. 11, the second sensor output S2 and the first sensor output S1 are negative, which is opposite to that during forward rotation. The signal is generated with a phase difference of (-90 degrees shifted by 180 degrees from the forward rotation). The detection signal is transmitted to the microcomputer 40 and stored in the storage unit 43.

  The sensor outputs S1 and S2 are sent to the forward / reverse determination unit 41. Thus, the forward / reverse determination unit 41 determines that the rotation direction of the impeller 21 is “reverse rotation” based on the phase difference between the two sensor signals shown in FIG. 11, and calculates the determination result as an arithmetic / integration circuit unit. 42, and the integrated value of the amount of tap water used is subtracted by 1 (-1). Thus, the rotation direction of the tap water metering rotation member 34, that is, the rotation direction of the impeller 21 is determined based on the positive or negative phase difference created by both sensor outputs S2 and S1. Here, the pulses output from the optical sensors 36 and 37 are arranged so that only one pulse is output for one rotation of the tap water metering rotation member 34. At this time, the weight of one pulse, that is, the amount of tap water corresponding to one pulse is set to 10 L (liter). Further, the duty ratio of the pulse is mechanically set to be 1: 1 as shown in FIG.

  In the illustrated example, in order to detect the rotational state of the impeller 21, both the optical sensors 36 and 37 have a phase difference of 90 degrees between the two pulses output from the optical sensors 36 and 37. It arrange | positions so that it may mutually have a space | interval of 90 degree | times in the rotation direction of the rotation member 34 for a tap water measurement.

  Next, a method for determining normal rotation or reverse rotation of the tap water measuring rotary member 34 will be described in detail. If there is a phase difference between the pulses output from the two optical sensors 36 and 37, based on the positive or negative phase difference generated according to the forward or reverse rotation of the tap water metering rotation member 34, It becomes possible to determine whether the tap water metering rotation member 34 is rotating forward or reverse. For example, when the tap water metering rotation member 34 is rotating forward, as shown in FIG. 10, the state of the first sensor output S1 at the rising edge of the second sensor output S2 is “H (high)”. In addition, the state of the first sensor output S1 when the second sensor output S2 falls is “L (low)”. On the other hand, when the tap water metering rotation member 34 is reversed, as shown in FIG. 11, the state of the first sensor output S1 at the rising edge of the second sensor output S2 is “L”. Further, the state of the first sensor output S1 at the time of falling of the second sensor output S2 is “H”.

  Thus, after the forward rotation or the reverse rotation of the tap water metering rotation member 34 is detected and determined, the determination result is stored in the storage unit 43. This stored data can also be used during instantaneous flow rate measurement described later. Further, “0” or “1” is appended to the instantaneous flow rate value of the stored data initial value depending on when the rotating member 34 is rotated forward or backward.

Next, the process of counting the integrated value of water usage will be described. When counting the integrated value, the impeller 21 confirms normal rotation or reverse rotation, that is, normal rotation or reverse rotation of the tap water metering rotation member 34, and then a value corresponding to the rotation speed of the tap water metering rotation member 34. Is added to or subtracted from the integrated value. In the case of addition, the value after 99999.99 m ³ (cubic meter) is 0000.00 m ³ , and the next value is 0000.01 m ³ , which is incremented by “1”. Similarly, in the subsequent addition, the integrated value increases by “1”. On the other hand, if the subtraction is next 0000.00M ³ is 9999.99M ^3, and this next goes is subtracted by "1" becomes 9999.98m ^3. Similarly, in the subsequent subtraction, the integrated value decreases by “1”. Therefore, the integrated value counting process is continued without stopping due to overflow or underflow.

  For example, the integrated value of the current water usage is counted and stored in the storage unit 43 at the rise and fall of the pulse of the second sensor output S2. At that time, after confirming normal rotation or reverse rotation of the tap water metering rotation member 34, the count-up or count-down is performed. The tap water corresponding to one pulse at this time is 5L.

As shown in FIG. 12, the configuration of the counter for measuring tap water is such that the number of digits in m ³ units is 4 digits, and the number of digits in L (liter) units is 2 digits of 100L and 10L. In the illustrated example, a 1L unit digit is provided as an auxiliary digit after a 10L unit digit. When the second sensor output S2 rises or falls, “5” is added to or subtracted from the auxiliary count, and the addition or subtraction determination at this time confirms whether the tap water metering rotation member 34 is rotating forward or reverse. To be determined. In the illustrated example, a decimal counter is displayed, but not limited to this, a binary counter or the like may be employed.

  Next, an example of counting during normal rotation of the tap water metering rotation member 34 will be described. First, when the second sensor output S2 rises, if the first sensor output S1 is in the “H” state, “5” is added to the auxiliary digit. If the first sensor output S1 is in the “L” state when the second sensor output S2 falls, “5” is added to the auxiliary digit. Then, when a carry appears in the auxiliary digit, “1” is added to the digit of 10 L unit. Thereafter, addition processing is performed in the same manner as described above.

  On the other hand, when counting is performed when the rotating member 34 for measuring tap water is reversed, the pulses are counted when the second sensor output S2 rises or falls when the sensor output during forward rotation shown in FIG. Assuming that the rotating member 34 for measuring tap water reverses and the second sensor output S2 falls after the second sensor output S2 rises, the second sensor output S2 is The counter is added when it rises, and the counter is subtracted when the second sensor output S2 falls during reverse rotation. That is, when the tap water metering rotation member 34 repeats normal rotation and reverse rotation due to vibration of the sensor output waveform, and the waveform of the second sensor output S2 repeats rising and falling, the counter is also added accordingly. Or, since the subtraction is repeated, no counting error occurs.

  Next, sampling of the sensor outputs S1 and S2 will be described. In some cases, the power consumption of the drive units (including sensor peripheral circuits) of each of the optical sensors 36 and 37 is large and unacceptable. On the other hand, in order to save current consumption, intermittent driving by sampling is extremely effective. When the optical sensors 36 and 37 are operated by the sampling, if the maximum pulse speed is, for example, 3 seconds / pulse, it is necessary to detect one pulse at least for 3 seconds in order to detect the waveform state of the sensor output. is there.

  Further, the sampling width is set so as to be sufficiently longer than the response speed of the optical sensors 36 and 37 within a range in which current consumption is allowed. At this time, the timing of capturing the output states of the optical sensors 36 and 37 is set so as to capture at the sampling end edge or in front thereof. The sampling pulse is a pulse for intermittently driving the optical sensors 36 and 37 (see FIG. 13). The on / off timing of the optical sensors 36 and 37 indicates an output waveform when it is assumed that the optical sensors 36 and 37 are always energized. Furthermore, the image of the waveform after sampling by the optical sensors 36 and 37 is a virtual sensor output waveform when the sensor output state is taken in.

  The water meter 11 according to the present embodiment can measure not only tap water but also instantaneous flow rate. The instantaneous flow rate measuring means includes a second gear 45 provided separately from the first gear 33 for measuring tap water, and a third optical sensor 50 for detecting the rotation state of the gear 45. . The gear 45 is provided so as to rotate at a high speed substantially equal to the rotational speed of the impeller 21. The instantaneous flow rate measurement is executed only when a request signal is received by communication, and is not executed otherwise. Therefore, since the instantaneous flow rate measurement is performed only for a limited time, it may be energized at all times during the measurement. However, turn off the power when instantaneous flow rate measurement is not performed.

  Next, measurement of instantaneous flow rate will be described in detail. As shown in FIG. 6, since the slits 49a to 49d are formed in a range of 45 degrees between the light shielding portions 48a to 48d, when the arc-shaped light shielding portions 48a to 48d make one rotation, The third optical sensor 50 detects and outputs four pulses. In the measurement of the instantaneous flow rate, the arithmetic circuit unit (instantaneous flow rate measurement circuit) 51 is operated, and the output pulse from the third optical sensor 50 is measured. Then, after calculating the instantaneous flow rate based on the measurement data, the calculation result is displayed and transmitted in a request response message for instantaneous flow rate.

When calculating the instantaneous flow rate, the number of rotations of the second gear 45 is counted at both rising and falling edges per pulse. In this way, if the pulses output from the third optical sensor 50 are 4 pulses per rotation of the gear 45, the number of pulses processed in the arithmetic circuit unit 51 is 8 pulses per rotation. . Note that the weighting per rotation of the second gear 45 necessary for calculating the instantaneous flow rate is referred to as a rate. Here, for example, if the number of pulses for 4 seconds is P pulses and the rate is K × 10 ⁻⁴ [L / 1 rotation], the instantaneous flow rate Q is

Formula 1

  The instantaneous flow rate Q is used for water leakage determination. At that time, all the faucets of the house that is the target of water leakage are closed, and when the instantaneous flow rate at that time is not 0, it is determined as “water leakage”.

  According to the present embodiment, when tap water flows in the reverse direction and the impeller 21 rotates in the reverse direction, the integrated value is subtracted for correction. Therefore, it is possible to prevent a calculation error caused by the backflow of tap water and always accurately measure the amount of tap water used. Moreover, since this water meter 11 is a gear transmission system, even if it falls into a measurement impossible state due to lightning, battery life, etc., the measured integrated value is stored as it is, and the main meter function is also maintained well. Furthermore, since the rotational state of the impeller 21 is optically sensed to calculate and integrate tap water usage, accurate measurement results can be stably obtained without being affected by magnetism from the outside. it can. Furthermore, since the optical sensors 36 and 37 for measuring tap water are driven intermittently during sensing, the amount of electricity consumed supplied to the optical sensors 36 and 37 and their peripheral circuits is greatly reduced.

  Since the present invention counts the rotational speed of the decelerated gear instead of the high-speed rotation of the impeller 21, a high-performance CPU is not required, current consumption is reduced, and a low-capacity battery can be used. You can go down.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

The longitudinal cross-sectional view which shows one Example which concerns on this invention, and demonstrates the structure of a water meter. The top view of the water meter which concerns on one Example. The rotating member for a tap water measurement which concerns on one Example is shown, (a) is a top view, (b) is AA sectional drawing of (a), (c) is a perspective view. The top view which shows the example of arrangement | positioning of the optical sensor for tap water measurement which concerns on one Example. The block diagram explaining the tap water measurement means of the microcomputer which concerns on one Example. The rotary member for instantaneous flow rate measurement concerning one example is shown, (a) is a top view, (b) is an AA sectional view of (a), and (c) is a perspective view. The block diagram explaining the instantaneous flow measurement means of the microcomputer concerning one example. The top view which shows the example of arrangement | positioning of the optical sensor for instantaneous flow volume measurement concerning one Example. The sensor output waveform figure explaining the duty ratio of the optical sensor for tap water measurement concerning one example. The sensor output waveform figure explaining the pulse wave at the time of forward rotation of the optical sensor for tap water measurement concerning one example. The sensor output waveform figure explaining the pulse wave at the time of reverse rotation of the optical sensor for tap water measurement which concerns on one Example. Explanatory drawing which shows the structural example of the counter part which concerns on one Example. The output waveform figure explaining the pulse sampling which concerns on one Example. The longitudinal cross-sectional view explaining the structural example of the conventional electronic water meter.

Explanation of symbols

11 Water meter 19 Passage (measuring room)
21 impeller 30 number wheel 32 first shaft portion 33 first gear 34 rotating member 35 for measuring tap water semicircular arc light shielding portion (detected portion)
36 First optical sensor (optical sensor for measuring tap water)
37 Second optical sensor (optical sensor for measuring tap water)
38 Printed Circuit Board 40 Microcomputer (CPU)
41 Forward / reverse determination unit 42 Operation / integration circuit unit 43 Storage unit 44 Communication function unit 45 Second gear 46 Second shaft unit 47 Instantaneous flow rate measurement rotating members 48a to 48d Arc-shaped light shielding unit (detected unit)
50 Third optical sensor (optical sensor for instantaneous flow rate measurement)
51 Arithmetic circuit

Claims (5)

The measuring unit has an impeller whose rotational speed increases or decreases according to the flow rate of tap water, and transmits the rotational speed of the impeller through a plurality of gears, and displays an integrated value of the rotational speed. Water meter
At the shaft portion of the gear constituting any one of the plurality of gears, a tap water metering rotation member having a detected portion such as a light shielding portion on the circumference is provided so as to rotate integrally with the gear. , Two optical sensors for measuring tap water for detecting the detected part and sensing the rotational state of the gear, such as the rotational direction and the rotational speed, are arranged, and a microcomputer is connected to the optical sensor,
The microcomputer includes a forward / reverse determination unit that determines forward or reverse rotation of the impeller, an addition process to the integrated value when the impeller is forward rotating, and the integration when the impeller is reversely rotated. An arithmetic / integration circuit unit that performs a subtraction process on the value, a storage unit that stores the integrated value data, and a communication function unit that transmits the integrated value data to an external automatic meter reading device, etc. Water meter.   The water meter according to claim 1, wherein sensing by the optical sensor is performed intermittently.   The two optical sensors are disposed with a predetermined interval in the rotation direction of the tap water metering rotation member, and the forward / reverse determination unit is configured to detect a phase difference between sensor outputs sent from the two optical sensors. The water meter according to claim 1, wherein the water meter is configured to determine a rotation direction of the impeller. The measuring unit has an impeller whose rotational speed increases or decreases according to the flow rate of tap water, and transmits the rotational speed of the impeller through a plurality of gears, and displays an integrated value of the rotational speed. Water meter
A rotating member for instantaneous flow rate measurement having a detected portion such as a light shielding portion on the circumference is provided on the shaft portion of the gear rotating in conjunction with the impeller so as to rotate integrally with the gear, and One optical sensor for instantaneous flow rate measurement that detects the detection unit and senses the rotation speed of the gear, and a microcomputer is connected to the optical sensor,
The microcomputer includes an arithmetic circuit unit that measures an instantaneous flow rate based on the number of rotations of the gear detected by the optical sensor, and a communication function unit that sends the measured instantaneous flow rate to an external automatic meter reading device or the like. A water meter characterized by comprising.   5. The water meter according to claim 4, wherein the instantaneous flow rate is measured only when there is a request from outside by communication.

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