JP2005257362A - Flow-measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To heighten voltage stability during operation by the operation of a charge pump type boosting means, according to the operation of a load, since a boosting means using a coil becomes a noise source during the operation of the load, when the operation of the boosting means is irregular. <P>SOLUTION: A power supply source control means 44 detects the operation of the load 6. By transmitting a signal to the charge pump type boosting means 43, which does not use a coil, according to the operation of the load 6 to adjust a voltage, electric power is supplied for the load 6 with a stable voltage. By performing a boosting operation at periods when the operation of the load is not affected, it is possible to implement such an operation of the boosting means which would not to affect the system by noise etc. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flow measuring device that uses a charge pump type boosting means for supplying power having a voltage higher than a power supply voltage to a load, and measures 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 measuring device using this is an electrical measuring method using ultrasonic waves (for example, see Patent Document 1). FIG. 17 is a block diagram showing a configuration of a general booster circuit. In FIG. 17, 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. 18 is a block diagram showing a configuration of an ultrasonic flowmeter as a conventional flow measuring device (see, for example, Patent Document 1).

  In FIG. 18, 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 the 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. Is a delay time measuring means for measuring the delay time, 19 is a delay time control means for controlling the delay time based on the measured value of the delay time generating means 17, and 20 is a time required for a plurality of ultrasonic transmissions performed by the repetition means. The accumulated time measuring means 21 is a flow rate calculating means for obtaining a flow rate from the measured values of the delay time measuring means 18 and the accumulated 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 the 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 of the load and the operation timing of the DCDC converter are not unified, and they operate individually. For example, even if the load operates and the voltage drops, the voltage boosting operation is not started unless the voltage drops to the threshold level of the DCDC converter. Then, when a voltage drop is detected after the load starts to operate, a boosting operation may be performed regardless of the operation of the load. As a result, the operating voltage of the load may change in the middle, or switching noise may occur.

  When the transducer on the transmission side of the flow measuring device is driven in a state where the boosted voltage is not constant, a transmission waveform with a different voltage is generated each time. Furthermore, if the booster circuit operates during a receiving operation, the system voltage may fluctuate or the measurement accuracy may be degraded due to noise.

  In addition, in a DCDC converter using an inductive element, there is a possibility that other circuits are affected by back electromotive force or induced noise during operation.

  The present invention solves the above-described problem. By controlling the charge pump type boosting means according to the operation of the load, power is supplied to the load at a stable voltage, and noise is generated by a circuit configuration that does not use a coil. The purpose of this is to realize the operation of the boosting means so as not to affect the system.

  An object of the present invention is to realize an accurate flow rate measurement that realizes a stable operation of the measurement system by using such a stable boost control means.

In order to solve the above-mentioned conventional problems, the power supply control means of the flow velocity or flow rate measurement means of the present invention controls the boosting operation of the power supply by the charge pump type boosting means according to the operation of the vibrator that transmits the ultrasonic wave as the load. To do.

  The flow measuring device of the present invention controls the boosting operation of the power source by the charge pump type boosting means in accordance with the operation of the vibrator that transmits the ultrasonic wave as a load.

  Thus, high voltage power is supplied to the vibrator as a load with a stable voltage by performing an operation of controlling the output voltage of the charge pump type booster according to the operation of the load.

  A first aspect of the present invention is a repetitive method in which a pair of transducers arranged in a flow path through which a fluid to be measured flows transmits / receives ultrasonic waves, a transmission / reception switching unit of the transducers, and an ultrasonic wave propagation between the transducers a plurality of times. Means, delay means for delaying the transmission signal from the vibrator at the time of repetition, time measuring means for measuring the propagation time of each of the plurality of repetitions, and calculating the flow rate based on the difference between the time measured values of the time measuring means Flow rate calculating means, a power source, a charge pump type boosting means for generating a high voltage from the power source, a load operating at the output of the charge pump type boosting means, and the charge pump type boosting means according to the operation of the load It is a flow measuring device provided with the power supply control means which controls.

  The power supply control means controls the charge pump type boosting means in accordance with the operation of the load, thereby supplying power to the vibrator as a load with a stable voltage and boosting with a circuit configuration that does not use a coil. Suppresses voltage instability and switching noise caused by operation. By realizing the operation of the boosting means that does not affect the system such as noise, it is possible to realize a highly accurate flow rate measurement that realizes a stable operation of the measurement system.

  In the second invention, in particular, the power supply control means of the first invention operates the charge pump type boosting means every time the load operates, so that the voltage fluctuation due to the operation of the load is always replenished, thereby stabilizing the voltage. It becomes possible to improve the degree.

  In the third aspect of the invention, in particular, when the power supply control means of the first aspect of the invention operates the charge pump type boosting means every time the load is operated a predetermined number of times, the state of the voltage fluctuation of the load is always the same in the case of repeated operation. It becomes possible to improve the reproducibility of the voltage fluctuation.

  According to the fourth aspect of the invention, in particular, when the power supply control means of the first aspect of the invention operates the charge pump type boosting means at the number of divisions that is the common divisor of the number of times of operation of the load, It is possible to supply electric power in the same voltage fluctuation state even when the state is in the first repetitive operation and the last repetitive operation.

  According to a fifth aspect of the invention, in particular, by operating the charge pump type boosting means before the power supply control means of the first invention operates the load, the high voltage can always be supplied when the load operates. Is possible.

  According to the sixth aspect of the invention, in particular, by operating the charge pump type boosting means after the power supply control means of the first aspect of the invention operates the load, immediately before the next operation by raising the voltage after the load operates. An operation in which noise generation is suppressed without operating the charge pump type boosting means becomes possible.

  According to the seventh aspect of the invention, in particular, the power supply control means of the first aspect of the invention operates the charge pump type boosting means in accordance with the state of the load, so that it is possible to quickly cope with the voltage rise against the load fluctuation. Become.

  According to the eighth aspect of the invention, the operation of the charge pump type boosting means is operated from the outside by the configuration in which the power supply control means of the first invention has the communication means that can adjust the setting state of the operation signal for the charge pump type boosting means from the outside. By doing so, it becomes possible to ensure a stable voltage supply even for system operation due to unexpected load fluctuations and disturbances.

  According to the ninth aspect of the invention, in particular, the power supply control means of the first invention has an aging adjustment means for changing the setting state of the operation signal for the charge pump type boosting means in accordance with aging, so that the load and charge due to aging changes. It is possible to follow the fluctuation of the pump type boosting means and adjust it, and it becomes possible to operate stably for a long time.

  In the tenth aspect of the invention, particularly, the power supply control means of the first aspect of the invention has a temperature change adjusting means for changing the setting state of the operation signal for the charge pump type boosting means in accordance with a change in ambient temperature. The load can be adjusted following the load and the charge pump type boosting means, and a stable voltage operation can be performed.

  The eleventh aspect of the invention has a configuration having a program for causing a computer to function as the power supply control means in any one of the first to tenth aspects of the invention, and thereby the operation of the charge pump type boosting means. It can be set and changed easily, and can flexibly cope with aging, etc., so that the accuracy of the output voltage can be improved more flexibly.

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

(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 rate measuring apparatus showing an example of a flow measuring apparatus according to 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 repeater 37 that receives the output of the receiver 35 and repeats the transmission / reception of the ultrasonic wave again through the transmitter 34 and stops the operation at a predetermined number of times, and the signal of the repeater 37 receives the predetermined delay A delay means 38 that outputs the trigger signal of the transmission means 34 with a time delay, and at least the propagation time of the ultrasonic wave from the start of driving of the first vibrator 32 by the transmission means 34 to the stop of the operation of the repeat means 37 are measured. It has time measuring means 39 and flow rate calculating means 40 (calculating means) 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 41 is provided, and a measurement start signal for operating the transmission unit 34 is output. Furthermore, a power supply 42 for supplying power, a charge pump booster 43 for driving a load having a higher voltage than the power supply, and a power supply controller 44 for controlling the power supply and the charge pump booster are provided.

  Normal operation will be described. Upon receiving the start signal from the measurement control means 41, the transmission means 34 pulse-drives the first vibrator 32 for a fixed 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 (Expression 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 41, 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 41 and the like will be described. FIG. 3 is a block diagram showing a configuration around the power source according to the present embodiment. In FIG. 3, 42 is a power source, 43 is a charge pump type boosting means, 44 is a power supply control means, 5 is a stabilizing capacitor, and 6 is a load. As an example of the charge pump type boosting means 43, it can be constituted by a switching boosting means 43a having at least one capacitor therein and a voltage stabilizing means 43b for stabilizing the output voltage.

  The operation of the charge pump type boosting means 43 will be described with reference to the block diagram of FIG. A charge pump type boosting means 43 composed of a switch and a capacitor is connected downstream of the power source 1, and its output is sent to a load 6 connected in parallel with the stabilizing capacitor 5.

  The charge pump type boosting means is controlled by oscillation from the power supply control means 44. In the charge phase, the switches S1 and S4 are opened and the switches S2 and S3 are closed. The power supply 1 charges the flying capacitor CF to the input voltage. Next, in the transfer phase, the switches S1 and S4 are closed and the switches S2 and S3 are opened. The voltage applied to CF is in series with the input voltage Vin, and both the power supply and CF are discharged to the stabilizing capacitor. The basic charge pump type boosting means operates as a voltage doubler. In FIG. 3B, the output voltage is twice the input voltage. The output voltage is increased by configuring this switch and CF in a plurality of stages in series.

  In FIG. 3A, the operation of the load 6 can be detected by the voltage control means 44. 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 44, and the power supply control means 44 adjusts the opening / closing operation of the switch so as to keep the output voltage of the charge pump type boosting means 43 constant by obtaining a voltage signal by, for example, an AD converter. Send a signal. In this way, the power supply control unit 44 detects the operation of the load 6 and sends a signal to the charge pump type boosting unit 43 according to the operation to adjust the voltage, thereby supplying power to the load 6 with a stable voltage. In addition, by operating the boosting means 22 at a time that does not affect the operation of the load, it is possible to realize the operation of the charge pump type boosting means that does not affect the system by noise or the like.

  If a high-precision voltage regulator is used as the voltage stabilizing means 43b, the voltage control is further improved. This is because the output voltage is stabilized by the step-down operation with the input of the voltage stabilizing means 43b as a high voltage. In general, the regulator is more stable than the DCDC converter, and the stability of the circuit is further improved.

  A difference from the conventional example will be described with reference to the timing of FIG. FIG. 4A shows the operation timing of the load in the DCDC converter 2 which is a conventional booster circuit. As the load operates, the output voltage of the boosting means 2 decreases as shown in FIG. Then, it is detected that the voltage has dropped at t1, and the DCDC converter operates.

The timing of t1 is determined only by the voltage and does not consider the operation of the load. Therefore, as shown in FIG. 4, even when the voltage drops while the load 6 is operating, the DCDC converter immediately starts the boosting operation. This indicates that the terminal voltage of the load fluctuates during operation. If it is used in a measuring device, the operating voltage fluctuates and the stability becomes worse.
Similarly, FIG. 4C shows the operation timing of the load when the power supply control means 44 of the present invention is used. FIG. 4D shows the operation timing of the power supply control means 44. Since the power supply control means 44 detects the operation of the load 6, when the operation of the load ends, a signal is sent to the charge pump type boosting means 43 at times t3 and t4 to adjust the switch operation to perform the boosting operation. Therefore, the output voltage of the charge pump type boosting means 43 is as shown in FIG. 4E, and the voltage can be changed by removing the operation timing of the load.

  The operation of the flow measuring device in the vicinity of the transmission means 34 from the power supply control means 44 will be described 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 charge pump type boosting means 43 is connected to the first vibrator 32 via the transmitting means 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 means 34, a bridge configuration using drive opening / closing means 34a to 34d to operate the vibrator is adopted. 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 charge pump type boosting means 43.

  As shown in FIG. 4B, when the high voltage is supplied by the operation of only the charge pump type boosting means 43 regardless of the operating state of the load (here, the vibrator), The supply voltage changes during operation, and the received signal is not constant. This is not preferable because it greatly affects the measurement accuracy of the flow rate. As shown in FIGS. 4D and 4E, the power supply control unit 44 detects the operation of the charge pump type boosting unit 43 and the operation of the vibrator 32, and the charge pump at a time when the operation of the vibrator 32 is not affected. The charge pump type boosting unit 43 supplies power to the vibrator with a stable voltage by sending a control signal so as to operate the type boosting unit 43 and does not affect the entire flow rate measurement system with noise or the like. Can be realized.

  In addition, the circuit configuration that does not use a coil as in the conventional DCDC converter can suppress the instability of voltage and switching noise due to back electromotive force and induced noise generated during operations such as boosting, and the effects of noise, etc. By realizing the operation of the boosting means so as not to give to the system, it is possible to realize a highly accurate flow rate measurement that realizes a stable operation of the measurement system.

  Furthermore, it is possible to further improve the voltage stability by providing a regulator as the power supply stabilizing means 43b at the output stage of the charge pump type boosting means 43.

  Since the power supply control means 44 can receive the measurement operation signal from the measurement control means 41 as a signal, the charge pump type boosting means 43 is controlled more securely without affecting the operation of the vibrator. To be able to. In FIG. 5, the power supply control means 44 and the measurement control means 41 are provided separately, but one logic means, for example, a microcomputer may be used as the same control means.

  Further, when the capacitor in the charge pump type boosting means 43 is halfway charged, the boosting operation is not yet required, but there is a case where the capacity is insufficient to supply power to the load. In this case, there is also a method in which the power supply control means 44 sends an oscillation signal to the charge pump type boosting means 43 to instruct an opening / closing operation of the switch, thereby creating a higher voltage and charging the output capacitor 43d.

  In addition, when the output voltage is monitored by the element itself of the charge pump type boosting means 43, an element that promotes power consumption such as a resistor is temporarily connected to the output, and the voltage is lowered and then the boosting operation is surely performed. It is also possible to take a method. Further, it is possible to finely adjust the output voltage of the charge pump type boosting means 43 by changing the oscillation operation signal from the power supply control means so as to change the number of operations of the switches in the charge pump type boosting means 43.

  Further, another operation will be described with reference to FIG. When the measurement control unit 41 operates and the first vibrator 32 operates, the output voltage of the charge pump type boosting unit 43 decreases. For this reason, when the first vibrator 32 operates as shown in FIG. 6A at times t0, t2, t4, and t6 in FIG. 6, the power supply is supplied as shown in FIG. 6B at t1, t3, t5, and t7, respectively. The control unit 44 operates the charge pump type boosting unit 43 to adjust the voltage. Since the power supply control means 44 can detect the operation of the vibrator serving as a load, the voltage can be adjusted every time the operation is performed.

  As a result, the output of the charge pump type boosting means 43 shows a stable voltage state as shown in FIG. In FIG. 6, the charge pump type boosting means 43 is operated after the vibrator serving as a load is operated. However, since the measurement operation can be understood by inputting a signal from the measurement control means 41, before operating the vibrator. It is also possible to adjust the voltage by operating the charge pump type boosting means 43.

  In this case, the boosting operation can be performed by simply controlling the number of oscillations so that the oscillation signal is the same every time and the same boosting and charging are performed.

  As described above, the power supply control unit 44 operates the charge pump type boosting unit 43 each time the vibrator 31 operates, so that voltage fluctuations due to the operation of the vibrator serving as a load are always replenished. It becomes possible to improve.

  Further, another operation will be described with reference to FIG. When the measurement control unit 41 operates and the first vibrator 32 operates, the output voltage of the charge pump type boosting unit 43 decreases. If the impedance of the vibrator is large, current does not flow so much, so this voltage drop is not so great. In such a case, if the voltage is adjusted too frequently, it may not be a good idea from the viewpoint of power saving.

  Accordingly, when the first vibrator 32 operates as shown in FIG. 7A at time t10 and t11 in FIG. 7 and the voltage drops to some extent, the power supply control means 44 performs charge pump type boosting as shown in FIG. 7B. The means 43 is operated to adjust the voltage. Since the power supply control means 44 can detect the operation of the vibrator serving as a load, the voltage can be adjusted every time the operation is performed. As a result, the output of the charge pump type boosting means 43 shows a stable voltage state as shown in FIG.

  After the operation of the charge pump type boosting means 43 in this way, the first operation voltage of the vibrator may be different from the second operation voltage, but the first time after the operation of the next charge pump type boosting means 43 is performed. The operating voltage is the same as the previous operating voltage. As a result, since the charge pump type boosting means 43 is operated after a certain number of times of operation of the vibrator, the voltage at each number is the same. Therefore, when the number of repetitions is increased, an accurate operation can be obtained as an average.

  In this way, by operating the charge pump booster 43 every time the vibrator as a load operates a certain number of times, the voltage fluctuation state of the vibrator can always be made the same when repeatedly operating. It becomes possible to improve the reproducibility.

  Since the voltage change width may be determined by the accuracy of the voltage stabilization means 43b inside the charge pump type boosting means 43, it is important to pay attention to the setting of the voltage threshold value of the voltage stabilization means 43b.

  Here, the description has been given of the operation of the charge pump type boosting means 43 every time the number of operations of the vibrator is constant, but the number of times does not always have to be the same when used for flow rate measurement. For example, the number of operations of the vibrator may be different, such as three times, five times, and four times, instead of every four times. In the flow measuring device, the switching means 36 switches between transmitting and receiving the vibrator. In this case, it is assumed that when the first vibrator is on the transmission side, the operation of the charge pump type boosting means 43 is operated in the form of the third, fifth, and fourth operations of the first vibrator 32. The power supply control means 44 stores this form so that the same charge pump boosting means 43 operates when the switching means 36 is inverted and the second vibrator 33 is on the transmission side. As a result, when the flow rate is calculated by (Equation 3), the voltage change between the transmission from the upstream and the transmission from the downstream can be made the same state, so that the reproducibility is improved and the variation degree of the measurement is reduced. Can do.

  Further, another operation will be described with reference to FIG. When the vibrator 32 operates, the output voltage of the charge pump type boosting means 43 decreases. Therefore, the charge pump type boosting means 43 is operated by a signal from the power supply control means 44 to compensate for this. Although it has been explained that the operation is effective even at a certain number of times, when the number of repetitions is large, the number of operations of the vibrator after the last charge pump type boosting means 43 is operated is less than the previous number of times, In the case of using for flow measurement, an error may occur that is biased toward the larger average value of the reception level.

  For example, in the case of flow rate measurement, if the number of times set in the repeating unit 37 is 12, for example, when the charge pump type boosting unit 43 is operated every 5 times for 12 repetitions, the charge pump type boosting unit 43 is finally operated. After that, the vibrator works only twice. Until then, when the charge pump type boosting means 43 is operated, the voltage drop is small and the reception level remains high in a smaller number of times compared to the case where the charge pump type boosting means 43 operates five times. For this reason, if the average of 12 times is taken, the value may be high. Therefore, in such a case, the power supply control means 44 adjusts the operation of the charge pump type boosting means 43 so as to be a common divisor of the number of repetitions.

  In 12 repetitions, the charge pump type boosting means 43 is controlled to operate when the vibrator operates 3 or 4 times. When the first vibrator 32 is operating as shown in FIG. 8A, the charge pump type boosting means 43 operates at t20 and t29 when operated three times as shown in FIG. 8B. Therefore, it can be seen that the number of repetitions is set to a multiple of 3. The fluctuation of the voltage also shows the same characteristic every three times when the vibrator operates, and the operation state of the last vibrator becomes the same as the voltage characteristic before the charge pump type boosting means 43 operates immediately before that. When the flow rate calculation means 40 calculates the value accumulated in the time measurement means 39 in the flow measurement, a more accurate value can be calculated when the same voltage fluctuation is repeated even when averaging processing is performed. It is possible to calculate a good flow rate value.

  In this way, when the power supply control means 44 operates the charge pump type boosting means 43 at the number of divisions that is the common divisor of the number of repeated operations of the vibrator that is the load, the voltage fluctuation of the load when the operation is repeated The power of the same voltage fluctuation state can be supplied even when the state is the first repeated operation and the last repeated operation, and accurate flow rate calculation is possible even when used for flow rate measurement.

  In the present embodiment, the ultrasonic vibrator has been described as an example of the load of the charge pump type boosting unit 43, but it goes without saying that it can be used without specifying the type of sensor or actuator if it is a voltage driven type load. .

  Further, the internal configuration of the charge pump type boosting means 43 is not limited to that shown in FIG.

  The flow rate calculation means 40 obtains the flow rate, but when the flow rate value is not required, for example, when fluid leakage is detected, the calculation means may be a means for obtaining only the flow velocity. Can be detected.

(Embodiment 2)
A flow measuring apparatus according to the second embodiment of the present invention will be described with reference to FIG. 1, FIG. 5, FIG. 9, FIG. 10, and FIG. The difference from the first embodiment is that the operation of the charge pump type boosting means 43 is performed in the vicinity of the load operation.

  First, the operation will be described with reference to FIG. 1, FIG. 5 and FIG. As shown in the first embodiment, a load such as a vibrator used in the flow measuring device operates, and the terminal voltage decreases. For example, when the first vibrator 32 of FIG. 1 operates, the output voltage of the charge pump booster 43 in FIG. 5 decreases. Therefore, the charge pump booster 43 must operate to compensate for this. Therefore, the operation of the vibrator is stabilized by adjusting the timing at which the charge pump type booster 43 is operated.

  When the first vibrator 32 operates as shown in FIG. 1A at time t31, t33, t35, t37 in FIG. 9 and the voltage drops to some extent, the times t30, t32, t34 as shown in FIG. 1B. , T36, the power supply control means 44 operates the charge pump type boosting means 43 to adjust the voltage. Since the operation of the vibrator serving as a load can be detected by the power supply control means 44, it is possible to adjust the voltage by sending a signal to the charge pump type boosting means 43 before the vibrator operates. As a result, the output of the charge pump type boosting means 43 shows a stable voltage state as shown in FIG. This is because the operation of the boosting means 22 is completed immediately before the operation of the vibrator, so that the voltage becomes an optimum value, and a high voltage can be supplied when the vibrator as a load operates. become. Furthermore, since noise generation due to inductance operation or the like for the entire system is eliminated, stable measurement operation can be performed even when applied to flow measurement.

  In FIG. 9, the charge pump type boosting means 43 always operates immediately before the vibrator operates. However, as shown in the first embodiment, the number corresponding to a fixed number of times or a common divisor of the number of operations. The charge pump type boosting means 43 may be operated before the vibrator operates every time.

  Other operations will be described with reference to FIGS. 1, 5, and 10. FIG. The operation of the vibrator is stabilized by adjusting the timing at which the charge pump type booster 43 is operated. When the first vibrator 32 operates as shown in FIG. 10A at time t40, t42, t44, and t46 in FIG. 10 and the voltage drops to some extent, time t41, t43, and t45 as shown in FIG. 10B. , T47, the power supply control means 44 operates the charge pump type boosting means 43 to adjust the voltage. Since the operation of the vibrator serving as a load can be detected by the power supply control means 44, it is possible to adjust the voltage by sending a signal to the charge pump type boosting means 43 after the vibrator operates. As a result, the output of the charge pump type boosting means 43 shows a stable voltage state as shown in FIG.

  This is because it is possible to accurately grasp the voltage drop after the operation of the vibrator, replenish it with the charge pump type boosting means 43 and operate the vibrator as the next load after the boosted voltage is stabilized. Therefore, stable system operation can be performed when applied to flow rate measurement. For example, when a large capacitive load is connected to the charge pump type boosting means 43, the voltage rise also changes with a large time constant, but if the voltage is adjusted after the operation of the vibrator is completed, The voltage can be adjusted to a stable voltage with a margin long before the next vibrator operates.

  In FIG. 10, the charge pump type boosting means 43 is always operated after the vibrator is operated. However, as shown in the first embodiment, the charge pump type boosting means 43 is operated every certain number of times or every number of times corresponding to the common divisor of the number of operations. A configuration may be adopted in which the charge pump type boosting means 43 is operated after the vibrator is operated.

  Other operations will be described with reference to FIGS. 1, 5 and 11. FIG. When the vibrator is operated a predetermined number of times in the flow measuring device and the flow rate measurement is completed, the switching means 36 is operated and the second vibrator 33 becomes the transmitting side. In this case, if the characteristics of the first vibrator 32 and the second vibrator 33 are the same, the operation of the charge pump type boosting means 43 may be made the same, but the characteristics of the vibrator may vary. Therefore, the operation of the vibrator is stabilized by adjusting the operation timing of the charge pump booster 43 according to the characteristics of the vibrator as a load.

  When the first vibrator 32 operates as shown in FIG. 11A at time t50 and t52 in FIG. 11 and the voltage drops to some extent, the power control means 44 operates at times t51 and t53 as shown in FIG. 11B. The charge pump type boosting means 43 is operated to adjust the voltage. After that, when the switching means 36 operates at time tch and the second vibrator 33 becomes the transmission side, the second vibrator 33 operates as shown in FIG. When the voltage drops, the control means 23 operates the charge pump boosting means 43 to adjust the voltage at times t55 and t57 as shown in FIG.

  Here, although the degree of voltage drop in FIG. 11C differs due to the change of the vibrator, the voltage is stabilized by adjusting the power supply control means 44. In this way, the power supply control means 44 can adjust the operation of the charge pump type boosting means 43 in accordance with the characteristics of the vibrator. Since the operation of the vibrator serving as a load can be detected by the power supply control means 44, which vibrator is currently operating can be recognized from the information from the measurement control means 41. For this reason, it is possible to adjust the voltage of the charge pump type boosting means 43 suitable for each vibrator. As a result, the output of the charge pump type boosting means 43 shows a stable voltage state as shown in FIG.

  In this way, the power supply control unit 44 operates the charge pump type boosting unit 43 in accordance with the state of the vibrator as a load, so that it is possible to quickly respond to a voltage increase with respect to fluctuations or changes in the vibrator. become. When used for flow rate measurement, a stable voltage can be supplied even if the vibrator is switched, so that it is possible to accurately calculate the flow rate according to (Equation 3) or the like.

(Embodiment 3)
A flow measuring apparatus according to the third embodiment of the present invention will be described with reference to FIGS. 1, 5, 12, 13, 14, 15, and 16. The difference from the first embodiment is that the charge pump type boosting means can be adjusted by an external signal so as to be stably performed over a long period of time.

  First, the operation will be described with reference to FIG. 1, FIG. 5, and FIG. When the first vibrator 32 of FIG. 3 operates, the output voltage of the charge pump type boosting means 43 in FIG. 5 decreases. Therefore, the charge pump type boosting means 43 must operate to compensate for this. As shown in the normal first and second embodiments, the voltage may be adjusted by operating the charge pump type boosting means 43 in accordance with the operation of the vibrator. However, if the algorithm of the measurement system is changed or another load is suddenly added, the operation of the power control means 44 may not be able to cope with it.

  For this reason, as shown in FIG. 12, the communication means 45 is connected to the power supply control means 44, and the operation state of the charge pump type boosting means 43 is monitored and the set value is adjusted with the external setting means 46. This communication may be wired or wireless. As described above, it is assumed that the power supply control unit 44 has the communication unit 45 that can adjust the setting state of the operation signal for the charge pump type boosting unit 43 from the outside, and operates the operation of the charge pump type boosting unit 43 from the outside. A stable voltage supply can be ensured even for system operation due to fluctuations in external loads and disturbances.

  In addition, another operation will be described with reference to FIGS. The capacity of the operation of the charge pump type boosting means 43 may decrease due to aging. Therefore, the operation of the vibrator is stabilized by adjusting the timing at which the charge pump type boosting means 43 is operated as the usage time elapses. As shown in FIG. 13, an aging adjustment means 47 is installed in the power supply control means 44, and the operation time and timing of the charge pump type boosting means 43 are adjusted accordingly when the system operation time becomes longer. As the secular change adjusting means 47, for example, a configuration in which a timer, a clock, and a storage means are combined may be used.

  In the initial stage of operation, when the first vibrator 32 operates as shown in FIG. 14A at time t60, t62, t64, and t66 in FIG. 14 and the voltage decreases to some extent, the time t61, as shown in FIG. At t63, t65, and t67, the power supply controller 44 operates the charge pump booster 43 to adjust the voltage. However, if the capacity of the charge pump type boosting means 43 decreases due to aging, the boosting operation cannot be completed in the same operation time. Special attention must be paid to aging of capacitors. In this case, as shown in FIG. 14C, the power supply control means 44 adjusts the operation of the charge pump type boosting means 43 longer based on the information from the secular change adjusting means 47. As a result, the output of the charge pump type boosting means 43 can maintain the initially set high voltage value.

  As described above, the power supply control unit 23 includes the secular change adjusting unit 47 that changes the setting state of the operation signal for the charge pump type boosting unit 43 according to the secular change, so that the load due to secular change and the charge pump type boosting unit 43 are changed. Therefore, it is possible to perform stable adjustment over a long period of time. Since the stability of the flow rate measurement is improved by stabilizing the high voltage to the vibrator, it is possible to continue the flow rate measurement while maintaining the accuracy for a long time.

  In addition, another operation will be described with reference to FIGS. The operation of the charge pump type boosting means 43 may be reduced in performance due to a change in the ambient temperature where the system is installed. Therefore, the operation of the vibrator is stabilized by adjusting the timing of operating the charge pump type boosting means 43 according to the change degree of the ambient temperature. As shown in FIG. 15, the power supply control means 44 is provided with a temperature change adjusting means 48 to check the temperature change during the operation of the system. When the ambient temperature becomes high due to sunlight, or when the temperature becomes low such as snow and ice, the operation time and timing of the charge pump type boosting means 43 are adjusted according to the temperature. Normally, in the assumed temperature range such as room temperature, when the first vibrator 32 operates at time t70, t72, t74, t76 in FIG. 15 at the initial stage of operation as shown in FIG. As shown in FIG. 15B, at time t71, t73, t75, t77, the power supply control unit 44 operates the charge pump type boosting unit 43 to adjust the voltage.

  However, when the temperature is in a high or low temperature state and the correction according to the temperature characteristics of the electronic component is in a necessary temperature range, the boosting operation cannot be completed in the same operation time. In particular, it is necessary to pay attention to the temperature characteristics of the capacitors around the charge pump type boosting means 43. In this case, as shown in FIG. 15C, the power supply control unit 44 adjusts the operation of the charge pump type boosting unit 43 to be longer based on the information from the temperature change adjusting unit 48. As a result, the output of the charge pump type boosting means 43 can maintain the initially set high voltage value.

  As described above, the power supply control unit 44 includes the temperature change adjusting unit 45 ** that changes the setting state of the operation signal for the charge pump type boosting unit 43 according to the ambient temperature change, so that the power control unit 44 is placed in an environment where the temperature change is severe. Therefore, it is possible to adjust the load and the charge pump type boosting means 43 to follow, and it is possible to perform a stable voltage operation. Since the stability of the flow measurement is improved by stabilizing the high voltage to the vibrator, it is possible to continue the flow measurement while maintaining the accuracy even in an environment where the temperature changes rapidly.

(Embodiment 4)
A flow measuring apparatus of the present invention relating to Embodiment 4 will be described. The difference from the first embodiment is that a storage medium 49 having a program for causing a computer to function in order to ensure the operation of the power supply control means 44 for adjusting the operation of the charge pump type boosting means 43 in the flow measuring device is provided. It is to use.

  In FIG. 1, FIG. 5, FIG. 12, FIG. 13 and FIG. 15, in order to perform the operation of the power supply control means 44 shown in the first to third embodiments, a charge pump type based on the operation of the vibrator is experimentally performed beforehand. The correlation of the operation timing of the charge pump type boosting means 43 is obtained with respect to the output change of the pressure means 43, the secular change, the temperature change, and the stability of the system, for example, in the form of the fitness like the membership function of fuzzy control. Determination software for determination is stored in the storage medium 49 as a program. Usually, it is convenient to use an electrically writable memory such as a microcomputer memory or a flash memory.

  As described above, when the operation of the power supply control unit 44 can be performed by a program, the operation of the charge pump type boosting unit 43 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 driving times, set and change the voltage adjustment conditions before and after the operation of the switching means 36, and flexibly cope with aging, 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 apparatus according to the present invention feeds a voltage for transmitting an ultrasonic wave from the charge pump type boosting means, so that the power control means raises the voltage by the charge pump type boosting means according to the operation of the vibrator as a load. In order to control the power, the power is supplied to the load with a stable voltage, and the charge pump type boosting means is operated while detecting the operation of the load. For this reason, it becomes possible to implement | achieve the operation | movement which does not give the influence of noise etc. to a system, and it can apply also to uses, such as a gas meter and various fluid measuring devices.

FIG. 1 is an overall block diagram of a flow measuring apparatus according to Embodiment 1 of the present invention. Timing diagram showing the operation of the flow measurement device (A) Block diagram of the periphery of the power source in the first embodiment of the present invention (b) Block diagram of the charge pump type boosting means Timing chart showing operation of charge pump type boosting means of the present invention and conventional booster circuit The block diagram which shows the connection of the transmission means periphery of the flow measurement apparatus in Embodiment 1 of this invention Timing chart showing the operation of the charge pump type boosting means of the flow measuring device according to the first embodiment Timing chart showing the operation of the charge pump type boosting means of the flow measuring device according to the first embodiment Timing chart showing the operation of the charge pump type boosting means of the flow measuring device according to the first embodiment Timing chart showing the operation of the charge pump type boosting means of the flow measuring device according to the second embodiment of the present invention. Timing chart showing the operation of the charge pump type boosting means of the flow measuring device in the second embodiment Timing chart showing the operation of the charge pump type boosting means of the flow measuring device in the second embodiment The block diagram of the flow measuring device in Embodiment 3 of this invention Block diagram showing the connection of the flow measurement device Timing chart showing the operation of the control means of the flow measuring device according to the third embodiment Block diagram showing the connection of the flow measurement device Timing chart showing the operation of the control means of the flow measuring device according to the third embodiment Block diagram of conventional booster circuit Overall block diagram of a conventional flow measurement device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply 6 Load 31 Flow path 32 1st vibrator | oscillator 33 2nd vibrator | oscillator 36 Switching means 37 Repeat means 38 Delay means 39 Time measuring means 40 Flow volume calculating means (calculation means)
43 Boosting means 44 Control means 45 Communication means 47 Aging change adjusting means 48 Temperature change adjusting means 49 Storage medium

Claims (11)

A pair of transducers arranged in a flow path through which the fluid to be measured flows and transmits / receives ultrasonic waves, a transmission / reception switching unit of the transducers, a repeating unit that performs ultrasonic propagation between the transducers a plurality of times, and the repetition A delay means that sometimes delays the transmission signal from the vibrator, a time measuring means that measures the propagation time of each of the multiple repetitions, and a calculation that calculates the flow velocity and / or flow rate based on the difference between the time measured values of the time measuring means Means, a power supply, a charge pump type boosting means for generating a high voltage from the power supply, a load operating at the output of the charge pump type boosting means, and controlling the charge pump type boosting means in accordance with the operation of the load A flow measuring device provided with power control means. 2. The flow measuring device according to claim 1, wherein the power supply control means operates the charge pump type boosting means every time the load is operated. 2. The flow measuring device according to claim 1, wherein the power supply control means operates the charge pump type boosting means every time the load is operated a predetermined number of times. 2. The flow measuring device according to claim 1, wherein the power supply control means operates the charge pump type boosting means every number of divisions which is a common divisor of the number of load operations. 2. The flow measuring device according to claim 1, wherein the power supply control means operates the charge pump type boosting means before the load operates. 2. The flow measuring device according to claim 1, wherein the power supply control means operates the charge pump type boosting means after the load is operated. 2. The flow measuring device according to claim 1, wherein the power control means operates the charge pump type boosting means in accordance with a load state. 2. The flow measuring device according to claim 1, wherein the power supply control means includes communication means capable of adjusting the setting state of the operation signal for the charge pump type boosting means from the outside. 2. The flow measuring device according to claim 1, wherein the power supply control means includes a secular change adjusting means for changing a setting state of the operation signal for the charge pump type boosting means in accordance with a secular change. 2. The flow measuring device according to claim 1, wherein the power supply control means has a temperature change adjusting means for changing a setting state of the operation signal for the charge pump type boosting means in accordance with a change in ambient temperature. The program for functioning a computer as a power supply control means of any one of Claims 1-10.

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