JP2003035583A - Gas meter and recording medium storing program for refreshing battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To activate effectively a lithium battery without increasing cost by using an ultrasonic oscillator as not only a flow meter but also a temperature detecting device. SOLUTION: In the gas meter having a lithium battery 9, measuring the flow rate of a gas to be measured passing through a gas conduit 52 by using a pair of ultrasonic oscillators 5a, 5b arranged in the gas conduit 52, and having a solenoid cutoff valve 8, a present temperature is calculated based on an arrival time of an ultrasonic wave between the ultrasonic oscillators 5a, 5b, thereby activating the lithium battery 9 at a proper timing of detecting a low temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas meter capable of effectively activating a battery as a driving power source by utilizing an ultrasonic transducer used as a flow rate sensor also as a temperature detecting element. The present invention relates to a recording medium that stores a battery refreshing program.

[0002]

2. Description of the Related Art A flow sensor using an ultrasonic transducer for detecting the amount of gas used, a pressure sensor for detecting gas leakage, and a seismic sensor for sensing an earthquake or the like are provided. There is known a gas meter having a function of closing the electromagnetic shutoff valve 8 to shut off the gas pipeline when the detected value is abnormal due to. A gas meter in which a lithium battery 9 is used as a drive source for the electromagnetic shutoff valve 8 and the like is known.

[0003]

In such a gas meter, the electromagnetic shut-off valve 8 which requires a large current is very rarely operated, and normally the flow rate sensor and the pressure sensor are operated as needed. I am only doing it. On the other hand, the lithium battery 9, which is the driving source of this type of gas meter, tends to be in a so-called inactive state in a situation where it is used for a long time with low power consumption such as the normal state of the gas meter described above. The inactive state is a phenomenon in which the battery voltage is lowered due to a slow chemical reaction even though the battery capacity is sufficient.

Particularly, when the lithium battery 9 is left in an inactive state at a low temperature for a long time, the voltage drop becomes more remarkable, and in that case, the electromagnetic shut-off valve 8 cannot be operated in an abnormal condition. There was a problem.
Further, in this type of gas meter, the battery voltage is normally checked by sending a signal only for a short time of about 20 ms. Originally, the battery voltage reference value considering the battery life is compared with the current battery voltage to determine the battery voltage drop considering the battery life, but the battery life is reduced due to the battery voltage drop due to the inactive state. There is a possibility that the battery life may be erroneously determined to be exhausted even though the battery remains. That is, there is also a problem that the battery voltage check cannot be accurately performed when the battery is inactive.

Therefore, in view of the above-mentioned current situation, the present invention utilizes the ultrasonic transducer used as the flow rate sensor also as the temperature detecting element, thereby effectively increasing the driving source without increasing the cost. An object is to provide a gas meter that can activate a battery and a recording medium that stores a battery refreshing program.

[0006]

A gas meter according to claim 1, which has been made to solve the above-mentioned problems, is equipped with a battery 9 as a drive source and has a gas pipeline as shown in the basic configuration diagram of FIG. An electromagnetic shutoff valve 8 for measuring the flow rate of the gas to be measured passing through the gas pipeline 52 using the ultrasonic transducers 5a and 5b arranged at 52 and for shutting off the gas pipeline 52 at the time of abnormality is provided. In the provided gas meter, the present temperature is calculated based on the ultrasonic wave arrival time obtained by the ultrasonic transducers 5a and 5b, and the present temperature is equal to or lower than the reference temperature at which the battery 9 is assumed to be in the inactive state. Has
It is characterized in that the battery 9 supplies the pseudo load circuit 10 with a drive signal equivalent to that at the time of driving the electromagnetic cutoff valve 8.

According to the first aspect of the invention, the temperature calculated using the ultrasonic wave arrival time by the ultrasonic transducers 5a and 5b is equal to or lower than the reference temperature at which the battery 9 is assumed to be in the inactive state. In this case, the battery 9 supplies the pseudo load circuit 10 with the same drive signal as when the electromagnetic cutoff valve 8 is driven. As a result, the battery 9 is activated. Therefore, the accuracy of the battery voltage check is improved.

A gas meter according to a second aspect of the present invention, which has been made to solve the above-mentioned problems, has a pair of batteries 9 mounted as a drive source and arranged in a gas pipeline 52, as shown in the basic configuration diagram of FIG. In the gas meter equipped with the electromagnetic shutoff valve 8 for shutting off the gas pipeline 52 at the time of abnormality while measuring the flow rate of the gas to be measured passing through the gas pipeline 52 using the ultrasonic transducers 5a, 5b of Based on the arrival time, a pseudo load circuit 10 having a load equivalent to that of the electromagnetic shutoff valve 8, an arrival time measuring means 101 for measuring an ultrasonic arrival time between the pair of ultrasonic transducers 5a and 5b, The temperature calculation means 102 for calculating the current temperature, the reference temperature storage means 1b for storing the reference temperature at which the battery 9 is assumed to be in an inactive state, and if the current temperature is equal to or lower than the reference temperature, To the dummy load circuit 10 from the pond 9, characterized in that it comprises a drive signal supply control unit 103 to supply the same driving signal and the time of driving of the electromagnetic cut-off valve 8.

According to the second aspect of the invention, when the temperature calculated based on the ultrasonic wave arrival time between the ultrasonic transducers 5a and 5b is equal to or lower than the reference temperature at which the battery 9 is assumed to be in the inactive state. The battery 9 is activated by supplying a drive signal from the battery 9 to the pseudo load circuit 10, which is equivalent to that for driving the electromagnetic cutoff valve 8. Therefore, the electromagnetic cutoff valve 8 operates reliably and the safety is improved. Moreover, the accuracy of the battery voltage check is improved.

A gas meter according to claim 3 made to solve the above-mentioned problems is, as shown in the basic configuration diagram of FIG. 1, in the gas meter according to claim 2, the arrival time measuring means 101 and the temperature calculating means. 102 and timing control means 104 for causing the drive signal supply control means 103 to function periodically.

According to the third aspect of the invention, the activation of the battery 9 as described above is performed periodically. Therefore,
The battery is reliably activated, and the drive signal supplied to the pseudo load circuit 10 for activation is also saved.

A gas meter according to claim 4 made to solve the above-mentioned problems is measured for calculating the present temperature in the gas meter according to claim 2 as shown in the basic configuration diagram of FIG. As the arrival time, the one used for measuring the flow rate is used.

According to the fourth aspect of the invention, since the arrival time measured for calculating the present temperature is the one used for measuring the flow rate, the ultrasonic transducer 5a, It is possible to enjoy the merit of combining 5b.

A recording medium for storing a battery refreshing program according to claim 5, which is made to solve the above-mentioned problems, has a battery 9 as a drive source mounted therein and a gas pipeline 52.
An electromagnetic cutoff valve 8 for measuring the flow rate of the gas to be measured passing through the gas pipeline 52 by using a pair of ultrasonic transducers 5a, 5b arranged in , And an arithmetic processing unit included in a gas meter having a pseudo load circuit 10 having a load equivalent to that of the electromagnetic shutoff valve 8 to measure arrival time of ultrasonic waves between the pair of ultrasonic transducers 5a and 5b. Means 101, a temperature calculation means 102 for calculating the current temperature of the place where the flow rate is being measured based on the arrival time, and the current temperature is below a reference temperature at which the battery 9 is assumed to be in an inactive state. In some cases, a battery lift for functioning as drive signal supply control means 103 for supplying from the battery 9 to the pseudo load circuit 10 a drive signal equivalent to that at the time of driving the electromagnetic shutoff valve 8. To store the Mesh for the program.

According to a fifth aspect of the present invention, an ultrasonic transducer 5 is provided.
The temperature is calculated based on the arrival time of ultrasonic waves between a and 5b. When this temperature is equal to or lower than the reference temperature at which the battery 9 is assumed to be in the inactive state, the battery 9 supplies the pseudo load circuit 10 with a drive signal equivalent to that at the time of driving the electromagnetic cutoff valve 8. Therefore, the electromagnetic cutoff valve 8 operates reliably and the safety is improved. Also, the accuracy of the battery voltage check is improved.

A recording medium for storing the battery refreshing program according to claim 6 which has been made to solve the above-mentioned problems is the recording medium according to claim 5, further comprising: the arithmetic processing section, and the arrival time measuring means. A battery refresh program for causing the temperature calculation unit 102, the temperature calculation unit 102, and the drive signal supply control unit 103 to function as a timing control unit 104 is stored.

According to the invention described in claim 6, the battery 9 as described above is activated periodically. Therefore,
The battery is surely activated, and the drive signal supplied to the pseudo load circuit 10 for activation is also saved to prolong the battery life.

According to another aspect of the present invention, there is provided a recording medium for storing a battery refreshing program according to claim 7, wherein the battery temperature is measured for calculating the present temperature. As the time, the one used for measuring the flow rate is used.

According to the invention described in claim 7, since the arrival time measured for calculating the present temperature is the one used for measuring the flow rate, the ultrasonic vibrator 5a, It is possible to enjoy the merit of combining 5b.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing a configuration according to an embodiment of the present invention.

In FIG. 2, this gas meter comprises a microcomputer 1, an operating section 2, a display section 3, a pressure sensor 4, an ultrasonic flow rate sensor 5, a seismic sensor 6, a communication section 7, an electromagnetic shutoff valve 8, a lithium battery 9 and The pseudo load circuit 10 is included. The operation unit 2, the display unit 3, the pressure sensor 4, the ultrasonic flow sensor 5, the seismic sensor 6, and the communication unit 7 are connected to the microcomputer 1 via the interface unit 11.
Further, the electromagnetic cutoff valve 8 is connected to the microcomputer 1 via a cutoff valve drive unit 81.

The microcomputer 1 includes a CPU 1a and a ROM 1
b and RAM 1c. It also includes a timer for measuring a refresh interval, a pseudo load operating period, etc., which will be described later. The CPU 1a executes basic control, flow rate and pressure detection, battery voltage check, and control related to this embodiment described later according to a control program stored in the ROM 1b. The ROM 1b stores in advance a basic control program, a control program for flow rate detection, an integrated flow rate calculation and pressure detection, a program for checking the battery voltage, a control program for refreshing the battery according to this embodiment described later, and the like. It Further, a refresh interval Δt1, a pseudo load operating period Δt2, a reference temperature Tr, etc., which will be described later, are also stored in advance. RAM1c
Basically functions as a work area for temporarily storing variables and data generated in the process of the CPU 1a. The ROM 1b corresponds to the recording medium described in claim 5. The recording medium may be a portable recording medium other than the ROM 1b. The ROM 1b also corresponds to the reference temperature storage means in the claims.

The operation unit 2 is composed of a switch group for inputting a command to start or stop the gas meter, stop the abnormality alarm, or change the display of the display unit 3. These commands are input to the microcomputer 1 by manually operating the operation unit 2.

The display unit 3 receives a command from the microcomputer 1 via the interface unit 11, and in response to this, displays an integrated flow rate and various abnormal alarms such as seismic shock, gas leakage, and battery voltage drop. . As the display unit 3, for example,
Known LEDs and the like are assumed. A plurality of L as the display unit 3
When the ED is used, different alarms can be displayed by changing the combination of LED displays.

As the pressure sensor 4, a known pressure detecting element that outputs a voltage according to the pressure value of the gas flow and supplies the voltage to the microcomputer 1 is used. The ultrasonic flow sensor 5 is composed of a pair of ultrasonic transducers arranged in the gas pipeline. The ultrasonic flow sensor 5 is connected to the microcomputer 1 via the sensor circuit unit 51. The microcomputer 1 is an ultrasonic flow sensor 5
The flow velocity and flow rate of the gas passing through the gas pipeline are calculated based on the arrival time of the ultrasonic signal between the pair of ultrasonic transducers.
This will be described later with reference to FIG.

The seismic sensor 6 is composed of a well-known seismic element which generates an on / off signal in response to a shake due to an earthquake or the like and supplies the on / off signal to the microcomputer 1 through the interface section 11. For example, the microcomputer 1 determines the degree of fluctuation from the number of ON / OFF signals received within a predetermined time, and when the fluctuation is large, performs abnormal processing such as valve closing control of the shutoff valve.

The communication unit 7 has a function of making a predetermined message call using a public line such as a telephone line. The communication unit 7 is also connected to a NCU (network control unit) 71 for controlling communication with a management center of a gas sales company via a public line such as a telephone line.

The electromagnetic cutoff valve 8 includes a valve drive solenoid coil and is connected to a cutoff valve drive section 81 which is a drive circuit for this solenoid coil. The shutoff valve drive unit 81 is instructed by the microcomputer 1 to generate a solenoid coil drive signal using the lithium battery 9 as a power supply source and supply the solenoid coil drive signal to the electromagnetic shutoff valve 8. In response to this, the electromagnetic shutoff valve 8 is opened or closed to control the shutoff of the gas pipeline.

The lithium battery 9 serves as a power supply source for this gas meter. The lithium battery 9 is often used in this type of gas meter because of its long-term use and high versatility, but on the other hand, it becomes inactive at low temperatures and the battery voltage drops even though there is battery power remaining. There are also things to do.

The pseudo load circuit 10 has a load characteristic equivalent to that of the electromagnetic cutoff valve 8. At the time of refreshing, which will be described later, the microcomputer 1 is instructed to supply a drive signal equivalent to the solenoid coil drive signal to the pseudo load circuit 10. The pseudo load circuit 10 is basically composed of a switching transistor and a resistor.

The interface section 11 basically comprises the microcomputer 1 and the respective constituent elements 2, 3, 4, 5 connected to it.
It has a voltage conversion function between 6 and 7.

A gas meter having such a configuration is, for example,
It is applied to LPG supply equipment. In this case, the gas meter is provided in a pipe that connects the pressure regulator that regulates the high-pressure gas housed in the LPG container and the gas combustor to which the regulated gas is supplied.

Then, this gas meter normally detects the flow rate of the gas passing through the gas pipeline using the ultrasonic flow rate sensor 5, and integrates the flow rate to display it on the display unit 3. Further, when the seismic sensor 6 detects an abnormal shake or the pressure sensor 4 detects an abnormal pressure, the gas meter displays a message to that effect on the display unit 3 and the electromagnetic shut-off valve 8
Close the valve. Further, at the same time, the gas meter transmits a message indicating an abnormal state to the management center of the gas sales company via the communication unit 7, the NCU 71, and a public line such as a telephone line. Furthermore, the battery voltage is periodically checked in this gas meter, and when the battery voltage drops, the fact is displayed on the display unit 3. Particularly, in the present embodiment, the temperature is measured by using the ultrasonic wave arrival time obtained by the ultrasonic flow sensor 5, and the lithium battery 9 is refreshed when the temperature is low. This principle and additional explanation are shown in FIG.
It will be described later with reference to FIG.

Next, the configuration of the ultrasonic flow sensor 5 and the sensor circuit portion 51 shown in FIG. 2 and the principle of temperature detection using the ultrasonic flow sensor 5 will be described with reference to FIG. FIG. 3 is an explanatory diagram showing a configuration of the sensor circuit unit and the ultrasonic transducer shown in FIG. 2 and an operation of the ultrasonic transducer.

As shown in FIG. 3, the sensor circuit section 51 includes
The transmission circuit 511, the reception circuit 512, and the switching circuit 513 are included. The switching circuit 513 is instructed by the microcomputer 1 to switch and connect the ultrasonic transducers 5a and 5b as the ultrasonic flow rate sensor 5 shown in FIG. 2 to the transmission circuit 511 and the reception circuit 512 alternately. When the ultrasonic transducer 5a is connected to the transmission circuit 511, the ultrasonic signal is transmitted from the ultrasonic transducer 5a to the ultrasonic transducer 5b. This ultrasonic signal propagates through the gas to be measured, and the receiving circuit 51
2 is received by the ultrasonic transducer 5b.
The ultrasonic transducer 5b, which has received the ultrasonic signal, generates a signal corresponding to this ultrasonic signal and supplies it to the microcomputer 1 via the receiving circuit 512. On the other hand, when the ultrasonic transducer 5b is connected to the transmitting circuit 511, ultrasonic signals are transmitted and received in the opposite direction to the above. The microcomputer 1 can calculate the flow velocity and flow rate of the gas to be measured based on the propagation times of ultrasonic signals in both directions.

That is, it is assumed that the pair of ultrasonic transducers 5a and 5b are arranged so as to face the gas conduit 52 at an angle θ. Here, in the figure, V is the average flow velocity of the measured gas flowing in the direction indicated by the arrow, L is the distance between the ultrasonic transducers 5a and 5b, and the line connecting the ultrasonic transducers 5a and 5b and the gas pipeline 52 Assuming that the angle formed by the central axis is θ and the arrival times of the ultrasonic signal in the up and down directions are tu and td, respectively, the average flow velocity V is V = L / 2COSθ (1 / td-1 / Tu). (Equation 1) Then, if the flow rate is Q, the passing area is S, and the correction coefficient is K, then Q = KSV ... (Equation 2), and thus the flow rate Q of the fluid passing through the gas pipeline 52 is calculated. Will be done.

By the way, when C is the ultrasonic velocity, the up and down arrival times tu and td are expressed as td = L / (C + VCOSθ) tu = L / (C-VCOSθ), respectively, so that td + tu = L / (C + VCOSθ) + L / (C−VCOSθ) = 2LC / (C ² −V ² COS ² ) = 2LC / C ² (∵C ² >> V ² COS ² ) = 2L / C. Therefore, the ultrasonic velocity C is obtained from this equation.

Further, when the fluid to be measured is LPG, it is known that the relationship between the ultrasonic velocity C and the temperature T (° C.) is C = 234.382 + 0.422T (Equation 3). Using this equation, the temperature T
Can be calculated.

In this embodiment, the temperature T is detected by using the ultrasonic transducers 5a and 5b in this way, and the lithium battery 9 is refreshed based on the temperature T when the temperature is low. Also, the ultrasonic transducer 5a for temperature detection,
The ultrasonic wave arrival time between 5b may be separately measured for this purpose, or the ultrasonic wave arrival time acquired during flow rate measurement may be used.

As described above, the ultrasonic transducers 5a and 5b, which are originally used as the flow rate sensor, are also used for temperature detection to correct the measured pressure, so that a highly accurate gas can be obtained without adding any parts. It becomes possible to detect leakage. In particular, by utilizing the arrival time for measuring the flow rate for calculating the current temperature, the merit of being shared is further increased.

Further, the processing procedure performed in this embodiment will be described with reference to FIGS. FIG. 4 is a flowchart showing a processing procedure according to the embodiment of the present invention. FIG. 5 is a time chart showing the refresh interval and the pseudo load operating period in the processing procedure of FIG. FIG. 6 is a flowchart showing a processing procedure according to another embodiment of the present invention.

In step S1 of FIG. 4, a predetermined start trigger is waiting (N in step S1). This start trigger is performed by a predetermined operation of the operation unit 2. If there is a start trigger, the process proceeds to step S2 and subsequent steps (Y in step S1).

Next, in step S2, the refresh timer t1 is started. This timer t1 corresponds to the refresh interval Δt1 shown in FIG. This refresh interval Δt1 is, for example, about 50 hours.

Then, in step S3, the refresh timer t1 is set to the refresh interval Δt.
It is on standby until the time defined by 1 is reached (N in step S3). When it is determined that the refresh timer t1 has reached the time defined by the refresh interval Δt1, the process proceeds to step S4 to measure the ultrasonic wave arrival time (Y in step S3).

Next, in step S4, the ultrasonic wave arrival time is measured. That is, the ultrasonic transducers 5a and 5b are switch-controlled so as to be in the transmitting and receiving states, and the up and down arrival times tu and td are measured. Then, in step S5, the temperatures are calculated by applying these arrival times tu and td and the above (formula 3).

Then, in step S6, the current temperature Tn calculated in step S5 is compared with the reference temperature Tr read from the ROM 1b. This reference temperature T
r is a temperature previously obtained by an experiment or the like that the lithium battery 9 is supposed to be in an inactive state, and is, for example, −2
It is 5 ° C. Here, if the current temperature Tn is equal to or lower than the reference temperature Tr, the process proceeds to step S7 and subsequent steps to refresh the lithium battery 9 (Y in step S7). On the other hand, if the current temperature Tn is higher than the reference temperature Tr, the process returns to steps S2 and S3 to wait for the next temperature detection timing.

In step S7, the load operation timer t2 is started. This timer t2 corresponds to the pseudo load operating period Δt2 shown in FIG. The pseudo load operating period Δt2 is, for example, about 2 seconds. Then, in step S8, a drive signal equivalent to the solenoid coil drive signal is supplied to the pseudo load circuit 10.

Further, in step S9, it is judged whether or not the load operation timer t2 has reached the pseudo load operation period Δt2, and if so, it is considered that the battery refresh is completed, and the series of processes is ended. (Y in step S9). After this end, the above steps S2 to S
9 may be repeated. On the other hand, if the load operation timer t2 has not yet reached the pseudo load operation period Δt2, the drive signal is transmitted until the pseudo load operation period Δt2 is reached.
Is continuously supplied to (N in step S9).

Thus, the lithium battery 9 as described above
By activating the battery periodically, the battery is surely activated, and the drive signal supplied to the pseudo load circuit 10 for activation is also saved to prolong the battery life.

Further, in step S101 of the other embodiment shown in FIG. 6, a predetermined start trigger is on standby (N in step S101). This start trigger is performed by a predetermined operation of the operation unit 2. Here, if there is a start trigger, the process proceeds to step S102 and thereafter (step S
101 Y).

Next, in step S102, the ultrasonic arrival time is measured. That is, the ultrasonic transducer 5
Switching control is performed so that a and 5b are in the transmitting and receiving states, and the up and down arrival times tu and td are measured. The arrival time measurement here is originally for measuring the flow rate, but as will be described later, it is also used for measuring the temperature in this embodiment.

In step S103, the measured arrival times tu and td are applied to the aforementioned (formula 1) and (formula 2) to calculate the flow rate Q. Together with this, in step S104, the arrival times tu, t
d is applied to the above (Equation 3) to calculate the current temperature.
In this way, by utilizing the arrival time for measuring the flow rate for calculating the current temperature, the merit of dual use becomes greater.

Then, in step S105, the current temperature Tn calculated in step S104 and the ROM 1b
The reference temperature Tr read from is compared. As described with reference to FIG. 4, this reference temperature Tr is a temperature at which the lithium battery 9 is assumed to be in an inactive state, and for example, −
25 ° C. If the current temperature Tn is equal to or lower than the reference temperature Tr, the process proceeds to step S106 (step S10).
5 Y). On the other hand, if the current temperature Tn is higher than the reference temperature Tr, the process returns to step S102 to wait for the next temperature detection timing.

In step S106, it is determined whether or not a predetermined time has passed since the last battery refresh. Only when the predetermined time has passed, the battery refresh process of step S107 and subsequent steps is performed (Y in step S106), and otherwise step S102. To return to. This is because if the battery is refreshed every time the flow rate is measured (at low temperature), the drive signal is frequently supplied to the pseudo load circuit 10 too much, and the power consumption for this may rather cause the voltage drop to proceed. Because. The elapsed time serving as a criterion for the determination here is, for example, about 50 hours, like the refresh interval Δt1 shown in FIG.

In step S107, the load operation timer t2 for battery refresh is started.
This timer t2 is the pseudo load operating period Δt2 shown in FIG.
It corresponds to. This pseudo load operating period Δt2
Is, for example, about 2 seconds. Then, step S10
In 8, the pseudo load circuit 10 is supplied with a drive signal equivalent to the solenoid coil drive signal.

Further, in step S109, it is determined whether or not the load operation timer t2 has reached the pseudo load operation period Δt2, and if it reaches, it is considered that the battery refresh has been completed, and the series of processes is ended. (Step S1
09 Y). After this is completed, the above steps S102-
You may make it repeat step S109. on the other hand,
If the load operation timer t2 has not yet reached the pseudo load operation period Δt2, the drive signal is continuously supplied to the pseudo load circuit 10 until it reaches (N in step S109).

The above steps S4 and S1
02 corresponds to the arrival time measuring means in the claims. Steps S5 and S104 correspond to the temperature calculating means in the claims. Steps S6 to S8 and steps S105 to S109 correspond to the drive signal supply control means in the claims. Then, step S2 and step S3 correspond to the timing control means in the claims.

As described above, according to this embodiment, the lithium battery 9 is effectively activated by the low temperature detection using the ultrasonic transducers 5a and 5b. As a result, the sensors including the electromagnetic cutoff valve 8 operate reliably and the safety is improved. In addition, since the normal battery voltage check can be always performed in the activated state, the accuracy of the battery voltage check is also improved. Furthermore, since the ultrasonic transducers 5a and 5b, which are originally used as the flow rate sensor, are also used for temperature detection, it is not necessary to add any parts and the cost does not increase.

[0059]

As described above, according to the first aspect of the invention, the current temperature calculated based on the ultrasonic wave arrival time obtained by the ultrasonic transducers 5a and 5b is the battery 9
When the temperature is lower than the reference temperature which is assumed to be inactive, the electromagnetic shutoff valve 8 is connected from the battery 9 to the pseudo load circuit 10.
The same drive signal as when driving is supplied. As a result, the battery 9 is activated. In addition, since the normal battery voltage check can be always performed in the activated state, the accuracy of the battery voltage check is also improved. Further, since the ultrasonic transducers 5a and 5b used as the flow rate sensor are also used for temperature detection, the cost does not increase.

According to the second aspect of the invention, when the temperature calculated based on the ultrasonic wave arrival time between the ultrasonic transducers 5a and 5b is equal to or lower than the reference temperature at which the battery 9 is assumed to be in the inactive state. The battery 9 is activated by supplying a drive signal from the battery 9 to the pseudo load circuit 10, which is equivalent to that for driving the electromagnetic cutoff valve 8. As a result, the electromagnetic cutoff valve 8 operates reliably and the safety is improved. In addition, since the normal battery voltage check can be always performed in the activated state, the accuracy of the battery voltage check is also improved. Furthermore, originally,
Ultrasonic transducers 5a and 5b used as flow rate sensors
Since it is also used for temperature detection, there is no need to add any parts and the cost advantage is great.

According to the third aspect of the invention, the activation of the battery 9 as described above is periodically performed. Therefore,
The battery is surely activated, and the drive signal supplied to the pseudo load circuit 10 for activation is also saved to prolong the battery life.

According to the invention described in claim 4, since the arrival time measured for calculating the present temperature is the one used for measuring the flow rate, the ultrasonic vibrator 5a, It is possible to enjoy the merit of combining 5b.

According to a fifth aspect of the invention, the ultrasonic transducer 5 is provided.
The temperature is calculated based on the arrival time of ultrasonic waves between a and 5b. When this temperature is equal to or lower than the reference temperature at which the battery 9 is assumed to be in the inactive state, the battery 9 supplies the pseudo load circuit 10 with a drive signal equivalent to that at the time of driving the electromagnetic cutoff valve 8. As a result, the electromagnetic cutoff valve 8 operates reliably and the safety is improved. In addition, since the normal battery voltage check can be always performed in the activated state, the accuracy of the battery voltage check is also improved. Furthermore, since the ultrasonic transducers 5a and 5b originally used as the flow rate sensor are also used for temperature detection, a cost advantage can be obtained.

According to the sixth aspect of the invention, the activation of the battery 9 as described above is periodically performed. Therefore,
The battery is surely activated, and the drive signal supplied to the pseudo load circuit 10 for activation is also saved to prolong the battery life.

According to the invention described in claim 7, since the arrival time measured for calculating the present temperature is the one used for measuring the flow rate, the ultrasonic vibrator 5a, It is possible to enjoy the merit of combining 5b.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a gas meter of the present invention.

FIG. 2 is a block diagram showing a configuration according to an embodiment of the present invention.

3A and 3B are explanatory diagrams showing a configuration of a sensor circuit unit and an ultrasonic transducer shown in FIG. 2 and an operation of the ultrasonic transducer.

FIG. 4 is a flowchart showing a processing procedure according to an embodiment of the present invention.

5 is a time chart showing a refresh interval and a pseudo load operation period in the processing procedure of FIG.

FIG. 6 is a flowchart showing a processing procedure according to another embodiment of the present invention.

[Explanation of symbols]

1 Microcomputer 2 operation part 3 Display 4 Pressure sensor 5 Ultrasonic flow sensor 6 seismic sensor 7 Communication section 8 electromagnetic shutoff valve 9 Lithium battery (battery) 10 Pseudo load circuit 1a CPU 1b ROM (reference temperature storage means) 1c RAM

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01F 15/06 G01F 15/06 G01K 11/24 G01K 11/24 13/02 13/02 F term (reference) 2F030 CA03 CB01 CC13 CE02 CE04 CE09 CE22 CE25 CE27 CF05 CF11 CF20 2F031 AA01 AB01 AE07 AF04 AF10 2F035 DA19 2F056 VS03 VS04 VS10 WF01 WF05 WF08

Claims (7)

[Claims] 1. A battery as a drive source is mounted, and the flow rate of a gas to be measured passing through the gas pipeline is measured by using an ultrasonic transducer arranged in the gas pipeline. In a gas meter equipped with an electromagnetic shutoff valve for shutting off a gas pipeline, a current temperature is calculated based on an ultrasonic wave arrival time obtained by the ultrasonic transducer, and the current temperature is assumed to be in an inactive state of the battery. A gas meter which supplies a drive signal equivalent to that at the time of driving the electromagnetic cutoff valve from the battery to the pseudo load circuit when the temperature is lower than a reference temperature. 2. A battery as a drive source is mounted, and the flow rate of the gas to be measured passing through the gas pipeline is measured using a pair of ultrasonic transducers arranged in the gas pipeline, and an abnormality is detected. At times, in a gas meter equipped with an electromagnetic shutoff valve for shutting off the gas pipeline, a pseudo load circuit having a load equivalent to that of the electromagnetic shutoff valve, and an arrival time for measuring an ultrasonic arrival time between the pair of ultrasonic transducers. Measuring means, temperature calculating means for calculating a current temperature based on the arrival time, reference temperature storing means for storing a reference temperature at which the battery is assumed to be in an inactive state, and the current temperature is the reference temperature. In the following cases, the gas meter is provided with drive signal supply control means for supplying the drive signal equivalent to that at the time of driving the electromagnetic cutoff valve from the battery to the pseudo load circuit. 3. The gas meter according to claim 2, further comprising a timing control unit that causes the arrival time measurement unit, the temperature calculation unit, and the drive signal supply control unit to function regularly. 4. The gas meter according to claim 2, wherein the arrival time measured for calculating the current temperature is the one used for measuring the flow rate. . 5. A battery as a drive source is mounted, and a flow rate of a gas to be measured passing through the gas pipeline is measured using a pair of ultrasonic transducers arranged in the gas pipeline, and an abnormality is detected. At times, an electromagnetic shutoff valve that shuts off the gas pipeline, and an arithmetic processing unit included in a gas meter that includes a pseudo load circuit having a load equivalent to this electromagnetic shutoff valve are provided. Arrival time measuring means for measuring the temperature, temperature calculating means for calculating the current temperature of the place where the flow rate is being measured based on the arrival time, the current temperature is a criterion assumed that the battery is in an inactive state. When the temperature is equal to or lower than the temperature, a drive signal supply control means for supplying a drive signal from the battery to the pseudo load circuit, which is equivalent to the drive signal at the time of driving the electromagnetic cutoff valve. A recording medium that stores programs. 6. The recording medium according to claim 5, wherein the arithmetic processing unit further functions as a timing control unit that causes the arrival time measurement unit, the temperature calculation unit, and the drive signal supply control unit to function regularly. A recording medium that stores a battery refreshing program for operating the battery. 7. The recording medium according to claim 6, wherein the arrival time measured for calculating the current temperature is a battery refresh program used for measuring the flow rate. Recording medium to store.