JP2006284267A - Flow measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly accurately measure flow rate by halting the operation of a boosting means by output of a flow rate computation means in the case of absence of flow or the absence of flow velocity, driving an oscillator at a low voltage, implementing a power-saving operation, and performing a boosting operation via a power control means at some time intervals. <P>SOLUTION: In the case of absence of flow velocity, the control means 47 does not make the boosting means 44 operate but feeds the oscillator with electric power. After a lapse of a predetermined number of times of measurement, the control means 47 makes the boosting means 44 operate and feeds a transmission means 34 with electric power at a voltage boosted to v2. It is possible to perform highly accurate measurement at regular intervals while saving power in this way. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flow measuring apparatus that uses a boosting unit that supplies power having a voltage higher than a power supply voltage to a vibrator and measures a flow velocity or a flow rate of gas or liquid using ultrasonic waves.

  As a conventional boosting means, there is one using a DCDC converter, and a flow rate measuring device using the DCDC converter is an electrical measuring method using ultrasonic waves (for example, see Patent Document 1). FIG. 12 is a block diagram showing a configuration of a general booster circuit. In FIG. 12, 1 is a power source, 2 is a DCDC converter, 3 is an inductance L, 4 is a diode D, 5 is a capacitor C, and 6 is a load. In the DC-DC converter 2, the back electromotive force generated in the inductance is rectified through the diode 4 when the inductance 3 is switched from on to off by switching the inductance 3, and a stable high voltage in which the ripple is reduced by the capacitor 5 is applied to the load 6. To supply. FIG. 13 is a block diagram showing a configuration of a conventional ultrasonic flowmeter (see, for example, Patent Document 1).

  In the figure, a first vibrator 12 that transmits ultrasonic waves and a second vibrator 13 that receives ultrasonic waves are arranged in the flow direction in the middle of a fluid flow path 11. Reference numeral 14 denotes a transmission circuit to the first vibrator 12, and 15 denotes a reception circuit that performs signal processing on the ultrasonic waves received by the second vibrator 13. Reference numeral 16 denotes a repeating unit that repeats transmission from the first vibrator 12 and reception by the second vibrator 13 after the ultrasonic wave is detected by the receiving circuit 15. Reference numeral 17 denotes delay time generating means for generating a delay time until ultrasonic waves are transmitted again from the first transducer 12 after the ultrasonic wave is detected by the receiving circuit, and 18 is a delay time generated by the delay time generating means 17. 19 is a delay time control means for controlling the delay time based on the measurement value of the delay time generation means 17.

  Reference numeral 20 denotes cumulative time measuring means for measuring the time required for a plurality of times of ultrasonic transmission performed by the repeating means, and reference numeral 21 denotes flow rate calculating means for obtaining a flow rate from the measured values of the delay time measuring means 18 and the cumulative time measuring means 20. The ultrasonic signal transmitted from the first transducer 12 by the burst signal transmitted from the transmission circuit 14 propagates in the flow, is received by the second transducer 13 and detected by the reception circuit 15, and delay time generating means After the delay time generated at 17 is set, the burst signal is transmitted from the transmission circuit 14 again. The burst signal from the transmission circuit 14 is repeated a predetermined number of times, and the time required for this repetition is measured by the accumulated time measuring means 20 and the delay time is measured by the delay time measuring means 10.

Further, the flow rate calculating means 21 obtains the required time T for only transmitting ultrasonic waves by subtracting the delay time obtained by the delay time measuring means 19 from the value obtained by the accumulated time measuring means 20. Normally, when driving a vibrator from this transmission circuit, a high voltage is supplied in consideration of the signal attenuation due to the propagation distance. As the circuit, the booster circuit described above is often used.
JP 2000-292232 A (2nd page, FIG. 1)

  However, in the conventional high voltage supply circuit in the booster circuit, the operation timing of the DCDC converter 2 considering the stability of the entire circuit is not unified and operates independently. For example, when there is no flow rate, when the flow velocity is zero, it often occurs at a considerable rate when installed as a measuring device. Considering home gas meters and water meters in particular, it is normal for the flow rate to flow in most of the day, that is, no flow rate is generated. Even in such a case, starting the operation of the DCDC converter 2 in order to measure the flow rate is wasteful when considering power in a battery-operated system or the like.

  The present invention solves the above-mentioned problem. When the circuit voltage is stable after power-on and there is no flow rate due to the output of the flow rate calculation means when operating the boost means, that is, the operation of the boost means when there is no flow rate. The purpose is to realize a highly accurate flow rate measurement in which the oscillator is driven at a low pressure and the pressure is increased with a certain time interval to realize a stable operation of the measurement system.

  An object of the present invention is to realize flow measurement with high power saving and accuracy by using such a boosting operation.

  In order to solve the above-mentioned conventional problems, the control means of the flow measuring device according to the present invention stops the operation of the boosting means at low pressure when there is no flow rate due to the output of the calculation means after power-on, that is, when there is no flow velocity. The vibrator is driven to perform a boosting operation with a certain time interval.

  The control means in the flow measuring device of the present invention stops the operation of the boosting means after turning on the power, drives the vibrator at a low pressure, and performs the boosting operation via the power supply control means at a certain time interval. .

  As a result, when there is no flow rate due to the output of the flow rate calculation means, that is, when there is no flow rate, the operation of the boosting means is stopped to drive the vibrator at a low pressure and realize power saving operation, and power control at a certain time interval By performing the step-up operation through the means, it is possible to realize accurate flow rate measurement.

  A first invention is a pair of transducers arranged in a flow path through which a fluid to be measured flows and transmits / receives ultrasonic waves, a transmission unit that drives the transducers, and a reception unit that converts an output signal of a reception-side transducer into an electrical signal A calculating means for calculating a flow rate using the signal of the receiving means, a power supply, a boosting means for generating a high voltage for the transmitting means from the power supply, a power supply control means for controlling the boosting means, and a control And the control means is a flow measuring device that operates the power supply control means in terms of time.

  When the power supply is turned on, the control means stabilizes the circuit voltage of the entire system, and when operating the boosting means, the control means performs a boosting operation with a certain time interval to achieve power saving and stable operation of the measurement system. Good flow rate measurement can be realized.

  In the second invention, the control means of the first invention operates the boosting means via the power supply control means in accordance with the signal of the arithmetic means, and there exists a flow rate or flow rate, that is, when there is a flow rate, It becomes possible to perform stable operation of the measurement system by increasing the operation frequency.

  In the third invention, particularly when the control means of the first invention has no flow velocity due to the output of the computing means, the operation of the boosting means is intermittently adjusted via the power supply control means, thereby making it possible to measure with the power saving operation. It becomes possible to continue.

  In the fourth invention, particularly when the control means of the first invention has a timer means, and there is no flow speed, the operation of the power supply control means is adjusted according to the signal of the timer means, so that the flow speed disappears. By adjusting the operation of the boosting means that operates intermittently according to the time, it is possible to further improve the power saving operation.

  In the fifth aspect of the invention, the control means of the first aspect of the invention has flow storage means for storing the previous flow velocity or flow rate, and the operation of the power supply control means is performed according to the signal of the flow storage means when there is no flow velocity. By adjusting, it is possible to adjust the operation of the boosting means that operates intermittently by predicting the next flow time according to the flow velocity or flow rate that flowed last time, and to further improve the power saving operation.

  According to a sixth aspect of the invention, the control means of the first aspect of the invention has a flow rate storage means for storing the previous flow rate and a timer means, and responds to the signal of the flow storage means and the signal of the timer means when there is no flow rate. By adjusting the operation of the power supply control means, the operation of the boosting means that operates intermittently is adjusted by predicting the next flow time according to the flow rate and the duration of the previous flow, and more power saving operation Can be increased.

  In the seventh invention, the control means of the first invention particularly has a storage means, and when there is no flow rate, by adjusting the operation of the power supply control means according to the signal of the storage means, the flow rate, time, season, It is possible to adjust the operation of the boosting means that operates intermittently by predicting the next flowing time according to a database such as temperature, and to further improve the power saving operation.

  In the eighth aspect of the invention, in particular, the control means of the first aspect of the invention has a setting means, and when there is no flow rate, by adjusting the operation of the power supply control means according to the signal of the setting means, It is possible to adjust the operation of the step-up means that operates intermittently by performing setting according to how to use from the outside, and to further improve the power saving operation.

  The ninth invention has a program for causing a computer to function as the control means in any one of the first invention to the eighth invention, and thereby, setting and changing the operation of the boosting means. Therefore, it is possible to improve the accuracy of the operation timing more flexibly because it can flexibly cope with aging.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment.

(Embodiment 1)
A flow measuring apparatus according to Embodiment 1 of the present invention will be described.

  FIG. 1 is a block diagram of a flow measuring apparatus showing the configuration of the first embodiment. In FIG. 1, a flow path 31 through which a fluid to be measured flows, a first vibrator 32 and a second vibrator 33 that transmit and receive ultrasonic waves arranged in the flow path 31 are installed, and the first vibration is provided. A transmission means 34 for driving the child 32; a reception means 35 for receiving a reception signal of the second vibrator 33; and determining a reception timing; the transmission means 34, the first vibrator 32, and a second vibrator; A switching unit 36 is provided between the first transducer 32 and the receiving unit 35 so that transmission / reception of ultrasonic waves is alternately performed between the first transducer 32 and the second transducer 33.

  The flow rate calculating means 41 (calculating means) receives the output of the receiving means 35, repeats the means 37 for repeating the transmission / reception of ultrasonic waves via the transmitting means 34, and repeat means 37 for stopping the operation at a predetermined number of times. A delay means 38 for receiving the signal of the repeat means 37 and outputting it as a trigger signal of the transmitter means 34 with a predetermined delay time delay, and at least the start of the driving of the first vibrator 32 by the transmitter means 34 It has time measuring means 39 for measuring the propagation time of the ultrasonic wave until the operation is stopped, and calculating means 40 for calculating the flow velocity between the pair of vibrators from the value of the time measuring means 39 and obtaining the flow rate therefrom. Further, a measurement control unit 42 is provided, and a measurement start signal for operating the transmission unit 34 is output. Furthermore, a power supply 43 for supplying power, a booster 44 for driving a load having a higher voltage than the power supply, and a power supply controller 45 for controlling the power supply 43 and the booster 44 are provided.

  Further, a storage means 46 for storing the setting values of the transmission means 34, the reception means 35, the switching means 36 and the flow rate calculation means 41, and a control means for sending the setting values of the storage means 46 to each means after the power source 43 is turned on. 47 is provided.

  Normal operation will be described. Upon receiving the start signal from the measurement control means 42, the transmission means 34 pulse-drives the first vibrator 32 for a certain period of time, and at the same time, the time measurement means 39 starts measuring time according to the signal from the measurement control means 41. An ultrasonic wave is transmitted from the pulse-driven first vibrator 32. The ultrasonic wave transmitted from the first vibrator 32 propagates through the fluid to be measured and is received by the second vibrator 33. The reception output of the second vibrator 33 amplifies the signal by the receiving means 35 and then determines the reception of the ultrasonic wave at the signal level at a predetermined reception timing. When the repeated operation is not performed, the operation of the time measuring means 39 is stopped when the reception of the ultrasonic wave is determined, and the flow velocity is obtained from the time information t by (Equation 1). Here, the measurement time obtained from the time measuring means 39 is t, the effective distance in the flow direction between the ultrasonic transducers is L, the sound velocity is c, and the flow velocity of the fluid to be measured is v.

v = (L / t) -c (Formula 1)
The receiving means 35 is usually configured to compare the reference voltage and the received signal by a comparator.

  In the current operation using the repeating unit 37, the determination result of the receiving unit 35 is delayed by a delay unit 38 for a certain period of time, then returned to the transmitting unit 34 and transmitted again. The repetitive operation is performed a predetermined number of times, the time is measured by the time measuring means 39, and the flow velocity is obtained by the calculation of (Equation 2) based on the measurement time of the time measuring means 39. Here, the delay time of the delay means is Td, the number of repetitions is n, the measurement time is ts, the effective distance in the flow direction between the ultrasonic transducers is L, the sound velocity is c, and the flow velocity of the fluid to be measured is v.

v = L / (ts / n-Td) -c (Formula 2)
According to this method, it is possible to measure with higher accuracy than the method of (Equation 1).

  Further, the first ultrasonic transducer 32 and the second ultrasonic transducer 33 are switched, and the respective propagation times of the fluid under measurement from upstream to downstream and from downstream to upstream are measured. Find v. Here, the measurement time from upstream to downstream is t1, and the measurement time from downstream to upstream is t2.

v = L / 2 ((1 / t1)-(1 / t2)) (Formula 3)
According to this method, the flow rate can be measured without being affected by the change in the sound speed, and thus it is widely used for measuring the flow velocity, the flow rate, the distance, and the like. When the flow velocity v is obtained, the flow rate can be derived by multiplying it by the cross-sectional area of the flow path 1.

  Normal operation is as shown in the timing diagram of FIG. That is, measurement is started from the start signal at time t0 by the measurement control means 42, and the first ultrasonic transducer 32 is driven via the transmission means 34 at t1. The ultrasonic signal generated there propagates in the flow path, reaches the second ultrasonic transducer 33 at time t2, and when the reception means detects the reception point, the repeat means 37 does not reach the set number of times. A signal is sent to the means 38. Then, the delay means 38 starts operating from time t3, operates for a predetermined time, and then sends a signal to the transmitting means 34 at time t4 to drive the first ultrasonic transducer 32 again. This is repeated below.

  When the number of times determined by the repeating means 37 is operated, the transmission / reception operation stops at time t5 in FIG. 2, and the time is T shown in the figure. Thereafter, the switching means 36 switches between transmission and reception. That is, the first ultrasonic transducer 32 is the reception side, and the second ultrasonic transducer 33 is the transmission side. Then, the same repeated operation is performed.

  Next, the vicinity of the power source that supplies power to the measurement control means 42 and the like will be described. FIG. 3 is a block diagram showing the configuration around the power source of this embodiment. FIG. 3 is a block diagram showing the configuration around the power source of this embodiment. A DC / DC converter will be described. In FIG. 3, 43 is a power supply, 44 is a boosting means, 45 is a power supply control means, 5 is a power storage means, and 6 is a load. The boosting means 44 can be constituted by a normal DC / DC converter having an inductance 44a and a diode 44b, or a charge pump type boosting means having at least one capacitor inside. Detailed description of the boosting operation of the DC / DC converter and the charge pump boosting means is omitted. The power supply stabilization means 44e is added to supply power to the system. Moreover, it has the voltage switching means 44f.

  In FIG. 3, the operation of the load 6 can be detected by the power supply control means 45. It is possible to adjust the boost voltage by controlling the switching means of the switch according to the voltage information. Further, the output voltage is measured by the power supply control means 45, and the power supply control means 45 sends a signal for adjusting the output voltage of the boosting means 44 to be constant, for example, by obtaining a voltage signal by an AD converter or the like.

  In this way, the power supply control means 45 detects the operation of the load 6 and sends a signal to the boosting means 44 according to the operation to adjust the voltage, thereby supplying power to the load 6 with a stable voltage. By operating the boosting means 44 at a time when it does not affect the operation of the load, it is possible to realize the operation of the boosting means that does not affect the system due to noise or the like.

  In FIG. 3A, the operation of the load 6 can be detected by the power supply control means 45. It is possible to adjust the boost voltage by controlling the switching means of the switch according to the voltage information. Further, the output voltage is measured by the power supply control means 45, and the power supply control means 45 sends a signal for adjusting the output voltage of the boosting means 44 to be constant, for example, by obtaining a voltage signal by an AD converter or the like. In this way, the power supply control means 45 detects the operation of the load 6 and sends a signal to the boosting means 44 according to the operation to adjust the voltage, thereby supplying power to the load 6 with a stable voltage. By operating the boosting means 44 at a time when it does not affect the operation of the load, it is possible to realize the operation of the boosting means that does not affect the system due to noise or the like.

  Usually, the fluid flows in the flow path 31 but does not always flow continuously. When the fluid is not used on the downstream side, the fluid is stopped inside the flow path 31. On the other hand, as a flow measuring device, accurate measurement is difficult unless the fluid state is always grasped. If you always use power abundantly and make careful measurements, you must have a large-scale power supply as a device. A battery-driven system or the like requires a large amount of batteries and is difficult to realize in terms of size and cost.

  Therefore, let's examine the measurement method. In FIG. 4A, the control means 47 does not operate until the time T1 when the output of the system voltage stabilization means 44e is stabilized after the power is turned on at time T0. Since the voltage is stable after T 1 in FIG. 4B, the control means 47 operates the boosting means 44 via the power supply control means 45 from T 2. An ultrasonic wave is transmitted by applying a high-voltage signal to the wave vibrator, and the flow velocity or flow rate is obtained as described above from the ultrasonic signal propagated through the flow path 31.

  In FIG. 4, the control means operates the boosting means 44 via the power supply control means 45 every intermittent fixed time to generate a voltage for supplying power to the transmission means 34. Measurement is performed at regular intervals. The vibration of the ultrasonic vibrator vibrates better as the input voltage is higher, and the level of the received signal is larger and it becomes possible to identify minute fluctuations in the fluid.

  When there is no flow velocity obtained by calculation, no fluid is used on the downstream side of the flow path 31. Such a state may be temporary, but once stopped, it may not be used for a long time. In such a case, it is necessary to devise from the viewpoint of power saving that the vibrator is frequently fed and measured.

  Thus, if the high voltage is always made, consumption of the power supply 43 becomes severe. Therefore, in the measurement, as shown in FIG. 4C, the voltage v1 is supplied to the vibrator by using, for example, the output of the system voltage stabilizing means 44e generated from the power supply without operating the boosting means 44. When a predetermined number of measurements has elapsed, the control means operates the boosting means 44 via the power supply control means 45 to supply power to the transmission means 34 with a voltage boosted to v2. When the vibrator is driven with a high voltage, the waveform of the received signal is large, and it becomes easy to detect a minute change and measurement with high accuracy is possible.

  In this way, when there is no flow rate due to the output of the flow rate calculation means, that is, there is no flow rate, the operation of the boosting means is stopped and the vibrator is driven at a low pressure to realize the power saving operation, and the power supply control at a certain time interval By performing the step-up operation through the means, it is possible to realize accurate flow rate measurement.

  When the power supply is turned on, the control means stabilizes the circuit voltage of the entire system, and when operating the boosting means, the control means performs a boosting operation with a certain time interval to achieve power saving and stable operation of the measurement system. Good flow rate measurement can be realized.

  The operation in the vicinity of the transmission means 34 from the power supply control means 45 as shown in FIG. In order to drive the first vibrator 32, it is necessary to drive the flow path 31 at a certain high voltage in order to transmit the inside of the flow path 31 at a sufficient ultrasonic signal level. Therefore, the output of the booster 43 is connected to the first vibrator 32 via the transmitter 34. Since the switching means 36 on the way only switches between transmission and reception, a detailed description here is omitted. As an example of the inside of the transmission unit 34, a bridge configuration using transmission opening / closing units 34a to 34d is used to operate the vibrator. First, the transmission opening / closing means 34a and 34d are energized, and on the contrary, 34b and 34c are opened.

  Next, the transmission opening / closing means 34a and 34d are opened, and 34b and 34c are energized. With this operation, the vibrator starts to operate. The power supply to the vibrator is supplied with a high voltage from the boosting means 44.

  If this high voltage is supplied by the operation of only the boosting means 44 regardless of the operating state of the vibrator, the supply voltage to the vibrator changes during the operation, and the received signal is not constant. This is not preferable because it greatly affects the measurement accuracy of the flow rate. Therefore, the power supply control means 45 detects the operation of the boosting means 44 and the operation of the vibrator 32, and sends a control signal to operate the boosting means 44 at a time when the operation of the vibrator 32 is not affected. Thus, it is possible to supply the power to the vibrator and to realize the operation of the boosting unit 44 so as not to affect the entire flow rate measurement system by noise or the like.

  Since the power supply control means 45 can receive the measurement operation signal from the measurement control means 42 as a signal, the booster means 44 can be controlled more reliably without affecting the operation of the vibrator. It becomes like this. In FIG. 5, the power supply control means 45 and the measurement control means 42 are provided separately, but one logic means such as a microcomputer may be used as the same control means.

  Further, a method of operating in consideration of returning to the normal operation during the operation of stopping the boosting means will be described. When the flow rate is equal to or less than a certain value or there is no flow, the control means 47 performs measurement by driving the vibrator with a low voltage enough to stop the operation of the boosting means and check only the presence or absence of the flow rate. Therefore, switching the measurement mode by the output of the flow rate calculation means 41 will be described. When the output of the flow rate calculation means 41 exceeds the preset flow rate in 101 of FIG. 6, the operation is switched to the measurement mode of 102. When the measurement mode is entered, the control means 47 operates the boosting means 44 via the power supply control means 45 to perform a boosting operation so as to obtain a driving voltage with a high measurement accuracy, for example, v2 in FIG. Increasing the voltage increases the received signal and enables accurate flow rate measurement. This operation may be dealt with by shortening the ratio of boosting at a constant interval as shown in FIG. This operation can be changed according to the flow rate.

  As a result, the control means 47 operates the boosting means 44 via the power supply control means 45 in response to the signal from the flow rate calculation means 41 to measure the increase in the operating frequency of the boosting means 44 when there is a flow rate, that is, when there is a flow velocity. It is possible to perform stable operation of the system.

  Further, a method for operating in consideration of further thinning out the operation of the boosting means will be described.

  When the flow rate is equal to or less than a certain value or there is no flow, the control means 47 performs measurement by driving the vibrator with a low voltage enough to stop the operation of the boosting means and check only the presence or absence of the flow rate. Therefore, a case where the output of the flow rate calculation means 41 is small over a long period will be described. When the output of the flow rate calculation means 41 becomes smaller than the preset flow rate in 101 of FIG. 6, the operation is switched to the search mode 103. When the search mode is entered, the control means 47 gradually increases the interval for operating the boosting means 44 via the power supply control means 45. Furthermore, the ratio of generating voltage of v2 by boosting is reduced. This may be an operation in which only one is performed. For example, the ratio of v2 and v1 may be gradually changed to reduce the frequency of boosting to v2 to create a power saving state, or the measurement interval is as shown in FIG. 7B when FIG. 7A is standard. The operating power of the entire measurement system may be reduced by increasing the length. This is possible because there is no flow for a long time.

  Thus, the control means 47 can continue the measurement with the power saving operation by adjusting the operation of the boosting means 44 intermittently via the power supply control means 45 when there is no flow velocity due to the output of the flow rate calculation means 41. become.

  Even in this case, it is necessary to set a time interval enough to return to the measurement mode and perform normal operation as soon as the flow rate becomes larger than the predetermined value Q0 in 101 of FIG.

  In the present embodiment, as an example of the fluid flow measurement device, the flow rate measurement device that calculates the flow rate of the fluid and calculates the flow rate from the flow rate by the calculation means has been described. A flow velocity measuring device that obtains the flow velocity may be used. In this case, the flow of the fluid may be interrupted by measuring a rapid flow velocity change or a flow velocity of a predetermined value or more. In particular, when the fluid is a gas, by providing a shut-off device in the pipe through which the gas flows, the gas leak can be detected and the leak can be shut off.

(Embodiment 2)
A flow measuring apparatus according to Embodiment 2 of the present invention will be described. The difference from the first embodiment is that a timer unit or a storage unit is provided to adjust a boosting operation related to a measurement operation when there is no flow rate. In this case, the flow rate measurement must be continued even when there is no flow velocity, but in normal measurement, the case where there is no flow velocity is often longer. For example, when considering a gas meter for home use, it can be considered that only a few hours of the day are used on the downstream side, and the state of zero flow rate is almost continuous. Even in such a case, it is necessary to perform accurate measurement in order to detect the beginning of the flow or to detect an abnormality on the downstream side. Therefore, it is considered to realize power saving by operating the boosting means intermittently according to the state where there is no flow velocity. This will be described with reference to FIGS. 1 and 8 to 11.

  As shown in the first embodiment, the fluid inside the flow path 31 in which the flow measuring device is installed does not move so frequently, but rather has a longer stop time. Therefore, how to check the fluid change without using electric power in the stopped state will be described below.

  FIG. 8 is a block diagram showing the periphery of the control means 47. The control means 47 inputs the output of the flow rate calculation means 41, and through the power supply control means 45 by individually or combining the signals of the timer means 49, the flow rate storage means 50 (flow storage means), the storage means 51, and the setting means 52. Controls the operation of the boosting means.

  It is assumed that the use of the fluid on the downstream side is reduced during the normal measurement, and the flow velocity disappears at t0 as shown in FIG. 9A. Until then, the control means 47 operated the boosting means 44 at regular time intervals to generate a high voltage and drive the vibrator. However, when the flow velocity is lost, it may not be necessary to measure frequently. For this reason, when the signal from the flow rate calculation means 41 indicates no flow rate, the control means operates the timer means 49 to increase the measurement interval from the current T0. As shown in FIG. 9 (b), the control means 47 operates at the interval of a predetermined time T1, and the control means 47 operates the boosting means 44 via the power supply control means 45 every time the T1 time elapses. Drive the child. As a result, when the state where there is still no flow rate continues, the interval is extended to T2, and further the measurement interval is expanded to T3.

  This measurement interval needs to be limited by a certain time Tmax. The timer means 49 determines the time interval. When it is determined that there is a flow rate from the signal of the flow rate calculation means 41 during the measurement, the control means 47 returns the measurement method to the conventional mode at the interval T0 and measures the flow rate.

  Thus, by adjusting the operation of the power supply control means 45 according to the signal of the timer means 49 when there is no flow speed, the operation of the boosting means 44 that operates intermittently according to the time after the flow speed disappears. It becomes possible to adjust and enhance the power saving operation.

  It is also possible to operate by estimating the next timing used on the downstream side based on the flow rate before the flow velocity disappears. For example, when the flow rate is as high as Q1 as shown in FIG. 10 (a), for example, when considering gas, a state such as reheating a bath by a water heater can be considered. In that case, since the same flow rate may be used next, it is necessary to catch the flow rate change quickly, so that when the signal from the flow rate calculation unit 41 has no flow rate, the control unit 47 stores the flow rate in the flow rate storage unit 50. Then, the flow rate storage means 50 returns, for example, to the control means 47 in proportion to the stored flow rate or the time learned through experience learning. Then, as shown in FIG. 10B, the control means 47 operates the boosting means 44 via the power supply control means 45 at intervals of a predetermined time T1, and generates a high voltage to control the vibrator as the transmission means. To drive.

  On the other hand, when the flow rate is small to some extent as shown in FIG. 10 (c), considering the gas, it is possible that the bathroom is heated, etc., the flow rate is low and the frequency of use is low, and the need for increasing the measurement frequency is reduced. . Therefore, when the signal from the flow rate calculation means 41 indicates that there is no flow velocity, the control means 47 stores the flow rate in the flow rate storage means 50, and the flow rate storage means 50 is proportional to the stored flow rate, for example, or the time learned through experience. Is returned to the control means 47. Then, as shown in FIG. 10 (d), the control means 47 operates the boosting means 44 via the power supply control means 45 at intervals of a predetermined time T2 to generate a high voltage to control the vibrator as the transmission means. To drive. Since the flow rate is small, there is no problem even if T2 is longer than T1.

  When it is determined that there is a flow rate from the signal of the flow rate calculation means 41 during the measurement, the control means 47 returns the measurement method to the conventional mode at the interval T0 and measures the flow rate.

  As described above, the control unit 47 has the flow rate storage unit 50 for storing the previous flow rate, and adjusts the operation of the power supply control unit 45 in accordance with the signal of the flow rate storage unit 50 when there is no flow rate, so By adjusting the operation of the boosting means that operates intermittently by predicting the next flowing time according to the flow rate, it is possible to further improve the power saving operation.

  It is also possible to operate by estimating the timing used next on the downstream side by combining the elapsed time after the flow velocity disappears and the flow rate when it has flowed.

  For example, as shown in FIG. 11, a function f (Q, t) of the flow rate Q and the time t after the flow velocity disappears may be considered. Although it is a linear function in the figure, this function is not limited to this form. Based on the values of the timer means 49 and the flow rate storage means 50, the control means 47 determines the measurement interval T. At that time, the control means 47 operates the boosting means 44 via the power supply control means 45, and the high voltage To drive a transducer as a transmission means.

  Taking gas as a fluid as an example, if the operation time is short even if the flow rate is large, the use of the kitchen can be considered. Conversely, if the flow rate is low and the flow time is long, a gas heater is estimated.

  In the case of a kitchen, the repetition frequency is high, but once the heater is stopped, it is presumed that the heater will stop for a long time until it is used again. Thus, the flow rate is greatly related to the estimation of the stop time. The timer means not only sets the measurement interval, but also enables more accurate estimation if the usage time is measured, and the measurement interval when the flow rate is stopped can be optimized. When it is determined that there is a flow rate from the signal of the flow rate calculation means 41 during the measurement, the control means 47 returns the measurement method to the conventional mode at the interval T0 and measures the flow rate.

  Thus, the control means 47 has the flow rate storage means 50 for storing the previous flow rate and the timer means 49, and when there is no flow rate, the power supply control means according to the signal of the flow rate storage means 50 and the signal of the timer means 49. By adjusting the operation of 45, the operation of the step-up means 44 that operates intermittently is adjusted by predicting the next flow time according to the flow rate and the duration time of the previous flow, thereby further improving the power saving operation. It becomes possible.

  Further, instead of using the data of the timer means 49 and the flow rate storage means 50, the function f (Q, t) is stored in advance in the storage means 51, instead of using the data of the timer means 49 and the flow rate storage means 50. May be stored like a table. When the flow rate is lost from the flow rate calculation unit 41, the control unit 47 can obtain the optimum measurement interval T by passing the time and the flow rate until then to the table of the storage unit 51. A function can be set in advance, and a fine measurement time interval can be set.

  When it is determined that there is a flow rate from the signal of the flow rate calculation means 41 during this measurement, the control means 47 returns the measurement method to the conventional mode at the interval T0 and measures the flow rate. The temperature and season database tables can also be set because the storage means 51 has become easier to enlarge.

  Thus, when the control means 47 has the storage means 51 and there is no flow velocity, the operation of the power supply control means 45 is adjusted in accordance with the signal of the storage means 51 to thereby store the flow rate, time, season, temperature, etc. in the database. Accordingly, it is possible to adjust the operation of the boosting means 44 that operates intermittently, for example, by predicting the next flowing time, thereby further improving the power saving operation.

  In addition, the combination of the elapsed time after the flow velocity disappears and the flow rate at the time of flow is not used in the data of the timer means 49 or the flow rate storage means 50, but, for example, on the downstream side connected to the flow path 31 It can be considered that the method of using the device is complicated, greatly varies depending on the season, or has a specific operation method depending on the installation location. In such a case. The setting means 52 may be used to input the function f (Q, t) from the outside like a table. The table set from the setting means 52 may be left in the storage means 51, and can be saved in a location such as a RAM inside the control means 47 if the conditions are small.

  The measurement interval is widened when there is no flow velocity using the set time interval T. Of course, if it is found that there is a flow rate from the signal of the flow rate calculation means 41 during this measurement, the control means 47 returns the measurement method to the conventional mode at the interval T0 and measures the flow rate.

  Thus, the control means 47 has the setting means 52, and when there is no flow velocity, the operation of the power supply control means 45 is adjusted according to the signal of the setting means 52, so that it can be used according to the place to be used or a specific usage. By performing the setting from the outside, it is possible to adjust the operation of the boosting means 44 that operates intermittently, and to further increase the power saving operation.

  In the present embodiment, the example in which the flow rate value stored in the flow rate storage unit 50 is used has been described. However, the same effect can be obtained even if the flow rate value stored in the flow rate storage unit is used as the flow storage unit. be able to.

(Embodiment 3)
A flow measuring apparatus according to Embodiment 3 of the present invention will be described. The difference from the first embodiment is that a storage medium 53 having a program for causing a computer to function to ensure the operation of the power supply control means 45 for adjusting the operation of the boosting means 44 is used.

  1, FIG. 3, FIG. 5 and FIG. 8, in order to perform the operation of the power supply control unit 44 shown in the first to second embodiments, the output of the boosting unit 44 by the operation of the vibrator is experimentally performed in advance. Correlation such as operation timing of the boosting means 44 with respect to change, aging, temperature change, system stability, etc. is obtained, and judgment software for judging in the form of fitness, such as a fuzzy control membership function, is stored as a program Stored in the medium 53. Usually, it is convenient to use an electrically writable memory such as a microcomputer memory or a flash memory.

  Thus, when the operation of the power supply control means 45 can be performed by a program, the operation of the boosting means 44 that follows the change in the driving voltage of the vibrator is performed by software. As a result, it is possible to easily set and change the condition of the number of transmissions, set and change the voltage adjustment condition before and after the operation of the switching means 36, and flexibly cope with secular change, etc., so that the accuracy of the measurement time can be improved more flexibly. . In this embodiment, operations other than the power supply control means 44 may be performed by a program using a microcomputer or the like.

  The flow measuring device according to the present invention stops the operation of the boosting unit and drives the vibrator at a low pressure when there is no flow rate by the output of the flow rate calculation unit after power-on, that is, when there is no flow velocity, and has a certain time interval. Thus, an operation for performing a boosting operation is performed.

  As a result, when there is no flow rate, that is, when there is no flow velocity, the operation of the boosting unit is stopped and the vibrator is driven at a low pressure to realize the power saving operation, and the boosting operation is performed via the power supply control unit at a certain time interval. By doing so, accurate flow rate measurement can be realized.

  Therefore, in a device in which a battery is mounted as an independent power source such as a home gas meter or a water meter, the battery capacity can be reduced, and the main body can be reduced in size and weight.

FIG. 1 is an overall block diagram of a flow measuring apparatus according to Embodiment 1 of the present invention. Timing chart showing the operation of the flow measuring device in the same embodiment Block diagram around the power supply in the same embodiment Timing chart showing operation of control means and boosting means in the same embodiment Block diagram showing connections around the transmission means of the measuring device Flow chart showing the setting order of the control means Timing chart showing the operation of the boosting means of the flow measuring device in the same embodiment The block diagram of the flow measuring device in Embodiment 2 of this invention Timing chart showing operation of flow velocity and boosting means in the same embodiment Timing chart showing the operation of the flow velocity and the boosting means of the flow measuring device in the same embodiment (A) Graph showing function of same boosting interval (b) Timing diagram showing operation time of same boosting means Overall block diagram of conventional booster circuit Overall block diagram of a conventional flow measurement device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply 5 Power storage means 6 Load 31 Flow path 32 1st vibrator 33 2nd vibrator 34 Transmission means 35 Reception means 41 Flow volume calculation means (calculation means)
43 Power supply 44 Boosting means 45 Power supply control means 47 Control means 49 Timer means 50 Flow rate storage means (flow storage means)
51 storage means 52 setting means 53 storage medium

Claims (9)

A pair of transducers arranged in a flow path through which the fluid to be measured flows and transmits / receives ultrasonic waves, a transmission unit that drives the transducers, a reception unit that converts an output signal of the reception-side transducer into an electrical signal, and the reception unit A calculation means for calculating a flow velocity or a flow rate using the signal, a power supply, a boosting means for generating a high voltage for the transmission means from the power supply, a power supply control means for controlling the boosting means, and a control means. The control means is a flow measuring device that operates the power supply control means in terms of time. 2. The flow measuring apparatus according to claim 1, wherein the control means adjusts the operation of the power supply control means according to a signal from the calculation means. The flow measuring device according to claim 1, wherein the control means intermittently adjusts the operation of the power supply control means when there is no flow velocity. 2. The flow measuring apparatus according to claim 1, wherein the control means has timer means, and adjusts the operation of the power supply control means in accordance with a signal from the timer means when there is no flow velocity. 2. The flow measuring apparatus according to claim 1, wherein the control means has flow storage means for storing the previous flow velocity or flow rate, and adjusts the operation of the power supply control means according to a signal of the flow rate storage means when there is no flow velocity. The control means has flow storage means for storing the previous flow rate or flow rate and timer means, and adjusts the operation of the power supply control means according to the signal of the flow storage means and the signal of the timer means when there is no flow rate. Item 1. The flow measuring device according to Item 1. 2. The flow measuring device according to claim 1, wherein the control means has storage means, and adjusts the operation of the power supply control means in accordance with a signal from the storage means when there is no flow velocity. 2. The flow measuring device according to claim 1, wherein the control means has setting means, and adjusts the operation of the power supply control means in accordance with a signal from the setting means when there is no flow velocity. The program for functioning the computer as a control means of any one of Claims 1-8.

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