JP3591694B2 - Gas shut-off method when gas voltage drops using gas processing equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gas meter using a processing device such as a battery-powered microcomputer for monitoring the gas use state and improving security, and in particular, a gas shut-off method for improving security after detecting a decrease in the battery capacity. About.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a gas meter using a processing apparatus uses a battery as a power source, and there is a high demand for avoiding abnormalities of the gas meter using the processing apparatus from the viewpoint of gas use security.
Therefore, the battery is periodically monitored for the ability to drive the battery shut-off valve, and if the battery voltage is low, an alarm state is displayed to notify the gas user or maintenance personnel by a display / notification function. .
In addition, when the battery voltage drops, shutting off the shut-off valve so that the gas cannot be used immediately can be troublesome for gas users. After a period of time, it is common to shut off the gas so that it cannot be used. Since a replacement gas meter can usually be prepared in one to two days, software for a gas meter using a processing device is prepared so as to secure more time for an alarm. The reason why the alarm state is finally shut off is to stop using gas before the battery is completely exhausted due to failure of the display / notification function.
[0003]
By the way, as a method of detecting a decrease in battery capacity, a maximum load in a gas meter using a processing device, or a pseudo load equivalent to the load, for a period of time required to drive the maximum load, A load current flows, a voltage detection circuit detects that the terminal voltage of the load has dropped below a predetermined value, and sends a signal to a processing device as a control device to display a low battery capacity or to issue a notification. It is common to do.
[0004]
In a gas meter using a processing device, when it is determined that gas is abnormally used, a shut-off valve is driven to stop gas supply. This is the maximum load. Therefore, a decrease in battery capacity is determined for a case where a load is applied to the shutoff valve.
It is a coil that drives the shut-off valve, and when the coil is energized for 50 ms (ms: millisecond) or more, the valve closes and the gas can be stopped. Further, this shut-off valve is of a self-holding type that mechanically holds the valve closed even when the power is turned off in order to reduce battery consumption of the gas meter using the processing device (the current flowing direction is opposite to the reverse direction). Then, some valves can be opened.) The equivalent impedance of the valve is, for example, 10Ω.
[0005]
FIG. 7 shows a conventional example of a gas meter using such a processing apparatus, and FIG. 8 shows the relationship between a command to supply current to a dummy load and the terminal voltage of a battery.
The circuit configuration of FIG. 7 is a system mainly including the processing device 1 and is driven by the lithium battery 2. This system monitors signals from a gas flow sensor 9, a pressure sensor 10, and a seismic sensor 11, and when an abnormality in gas usage, an abnormality in pressure, or an occurrence of an earthquake is detected, the processing device 1 is shut off. A command is issued to the valve driving transistor 8, the shutoff valve 5 is closed, and the supply of gas is stopped.
The dummy load 3 is for detecting a decrease in battery capacity, has the same impedance as the shut-off valve 5, and its terminal voltage is input to the voltage detection circuit 4. The voltage detection circuit 4 outputs a logical output to the processing device 1 when the terminal voltage at the time of energization falls below a predetermined value. A signal is output from the processing device 1 by this output, and the display / notification means 12 displays / notifies a decrease in battery capacity.
[0006]
A method for detecting a decrease in battery capacity will be described below.
First, when a command from the processing device 1 is sent to the battery capacity test transistor 7 (see time 0 in FIG. 8), the transistor 7 is turned on (ON), and the pseudo load energizing transistor 6 is immediately turned on. A current flows through the dummy load 3. As a transistor for energizing the dummy load 3, a single transistor can directly energize the dummy load 3 as long as it is equivalent to the shut-off valve driving transistor 8. However, in order to reduce cost, The configuration uses two cheaper transistors (6, 7).
[0007]
The terminal voltage of the dummy load 3 is input to the voltage detection circuit 4. The voltage detection circuit 4 is a circuit or an element that outputs a logical output when the applied voltage becomes equal to or lower than a predetermined voltage, for example, represented by a voltage detection IC. In this case, the predetermined voltage of the voltage detection circuit 4 is set to the minimum operating voltage of the shutoff valve 5. One example of the minimum operating voltage of the shut-off valve 5 in the case of a lithium battery is 1.8V. When the terminal voltage of the dummy load 3 in the energized state becomes equal to or lower than the predetermined voltage, the voltage detection circuit 4 outputs a logical output to the processing device 1, and upon receiving the output, outputs a signal from the processing device 1 to the display / notification means 12. Then, the display / notification means 12 displays a low battery capacity by a light emitting diode (LED) and issues a notification of the low battery capacity by communication. It should be noted that the processing device 1 does not accept the output signal of the voltage detection circuit 4 when the power supply command to the pseudo load 3 is not issued from the processing device 1.
[0008]
Next, the relationship between the energization command and the battery terminal voltage when the dummy load 3 is actually energized will be described with reference to FIG.
When an energization command is issued at time 0 and a current flows through the dummy load 3, the terminal voltage of the battery decreases. The energization command is sent for 100 ms longer than 50 ms, which is the time required for driving the shut-off valve 5. During this 100 ms, the processing device 1 monitors the output signal of the voltage detection circuit 4. Therefore, if the terminal voltage of the dummy load 3 does not drop below the predetermined value during this 100 ms, no logic output is output from the voltage detection circuit 4 and the battery capacity is determined to be OK. Since there is a difference between the terminal voltage of the dummy load 3 and the terminal voltage of the battery by the voltage drop of the dummy load energizing transistor 6, the terminal voltage of the dummy load 3 is also substantially the same as the terminal voltage of the battery in FIG. It can be treated as decreasing with the tendency.
[0009]
Conventionally, such detection of a decrease in battery capacity is performed, for example, every 25 hours. The reason is to minimize battery consumption due to the above operation. The reason why the time is extended by one hour compared to 24 hours a day is to monitor the battery during the day and at night over about 24 days.
As described above, the gas meter using the processing device determines a decrease in the ability to drive the shut-off valve with the battery and detects a decrease in the battery voltage. When a battery voltage drop is detected, the gas meter using the processing device displays a warning after a display / report, and then shuts off the gas for a certain period of time, for example, 72 hours (3 days later) in a state where the gas cannot be used again. Close the valve.
[0010]
[Problems to be solved by the invention]
As described above, the gas meter using the processing apparatus enters a shut-off state in which gas cannot be used after a warning state in which gas can be used for a certain period of time after detection of a decrease in battery voltage. Since the gas meter using the processing device is replaced at the same time as the gas meter replacement cycle is 10 years, the design value of the battery capacity is designed to be usable for 10 years, but the voltage drop is detected within less than 10 years In fact, there are many cases where the temperature falls in winter, especially during winter. This is considered to be one of the causes of a decrease in the shut-off valve driving capability at low temperatures.
If the gas meter is not replaced before the battery voltage drop warning state is switched to the cutoff state, it is required that the shutoff valve be securely closed even when the battery capacity in winter is reduced due to, for example, display or notification failure. Is done.
FIG. 6 shows the temperature characteristics of the battery usage and the terminal voltage of the battery when the shut-off valve is driven. From the figure, it can be seen that the terminal voltage of the battery is higher when the ambient temperature is higher when the shut-off valve is driven, and the ability to drive the shut-off valve is higher.
[0011]
However, as described above, in the method of shutting down after a certain period of time after the battery voltage drops to the alarm state, there is a high possibility that the shutoff output will occur at the lowest winter night. That is, since voltage monitoring is conventionally performed for 25 hours, voltage monitoring during the day and night is performed over about 24 days. If a voltage drop is detected, the voltage is shut off and output 72 hours later. If a voltage drop is detected in step (1), the output is cut off at night. Even if the time is increased or decreased from 72 hours to 12 hours, if the time is constant, there is no guarantee that the timing of shut-off output from the low alarm state can be in the daytime when the temperature rises relatively even in winter.
Therefore, an object of the present invention is to make it possible to more reliably close the shut-off valve even in a battery voltage drop warning state in consideration of the battery temperature characteristics.
[0012]
[Means for Solving the Problems]
In order to solve such a problem, in the invention of claim 1, when the battery voltage of the gas meter using the processing device is in a low alarm state, for example, the gas can be used for 48 hours, that is, the gas can be used. When a low alarm condition is detected, the passage of time is monitored by a built-in clock, and after 48 hours, a shut-off output is performed at 12:00 noon to stop the use of gas.
According to the second aspect of the present invention, an A / D converter capable of taking in the battery voltage with an analog value is provided, and the battery voltage is continuously monitored with the analog value even in the low alarm state. When is maximized, a cut-off output is made.
According to the third aspect of the present invention, a temperature sensor capable of monitoring the temperature with an analog value is provided, and when the ambient temperature of the gas meter becomes maximum within 48 hours to 72 hours of the lowering alarm state as in the second aspect, The output is cut off.
[0013]
Further, according to the invention of claim 4, an optical sensor capable of detecting the ambient brightness, for example, a phototransistor, an amplifier and an A / D converter capable of taking in an analog value are provided, and a low alarm state from 48 hours to 72 hours as in claim 2 Within, when the surrounding brightness becomes maximum, the cut-off output is performed.
According to the fifth aspect of the present invention, a sound collector such as a condenser microphone, an amplifier and an A / D converter capable of capturing an analog value can be provided for the audio signal around the gas meter. When the signal of the voice band around the gas meter exceeds a certain value, it is determined that the daytime is in progress and the output is cut off.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a flow chart showing the first embodiment of the present invention.
This indicates a processing operation by the processing apparatus 1 as shown in FIG. 7, and operates, for example, every 100 ms (see step S1).
That is, the gas meter using the processing device monitors the flow sensor, the pressure sensor, and the seismic sensor every 100 ms (see steps S2 to S4), displays and reports (see step S5), and monitors the clock every 100 ms as in the conventional example. In addition to executing the integration process (see step S6), if the battery voltage monitoring timing is 25 hours (see step S7), the battery voltage is checked (see step S8).
[0015]
When the battery voltage is checked and a voltage drop is detected (yes (Y) in step S9), 48 hours are counted from the detection point, and after the lapse of 48 hours (see Y in step S10), the processing device is used. The current time is determined by referring to the clock in the gas meter. If the current time is 12:00 noon (see Y in step S11), a cutoff output is issued (see step S12).
In this way, when the gas meter using the processing device detects a decrease in the battery voltage, displays and informs the user, and then operates as an alarm state for at least 48 hours as a grace period for replacing the gas meter. If the gas meter is not replaced yet, the cut-off output can be performed at a time when the temperature is relatively high in one day and the battery is in good condition.
[0016]
FIG. 2 is a configuration diagram showing a second embodiment of the present invention.
That is, the feature is that an A / D converter 13 for taking the battery voltage into the processing device 1 in an analog amount is provided in place of the voltage detection circuit 4 for detecting one point of 1.8 V in FIG. This is because it is known that the battery has the temperature characteristic as shown in FIG. 6 even when the battery is open. For example, when a 10 Ω shutoff valve is driven, it is advantageous when the open voltage of the battery is high. It depends.
[0017]
When the configuration is as shown in FIG. 2, the operation in the flowchart of FIG. 1 is changed as follows.
That is, in steps S1 to S10, an analog amount is converted into a digital amount by an A / D converter instead of the voltage detection circuit, and the digital amount is taken into the microcomputer. Has never changed. However, in step S11, the open-circuit voltage of the battery is monitored, and it is confirmed that the open-circuit voltage has become maximum. The reason for monitoring the open state of the battery is that a drop in the battery voltage has already been detected, and starting a pseudo load in a state where the open voltage of the battery is low will place an excessive burden on the weak battery. .
[0018]
FIG. 3 is a configuration diagram showing a third embodiment of the present invention.
That is, the present embodiment is characterized in that a temperature sensor 14 is provided in the conventional device shown in FIG. It is desirable to use a low-power-consumption type temperature sensor that oscillates an analog value as a digital pulse, for example.
The operation in the flowchart of FIG. 1 in the case of the configuration as shown in FIG. 3 is the same as that of the conventional case in steps S1 to S10. When the temperature sensor 14 is driven in step S11 and the temperature becomes maximum, The difference is that a cutoff output is output in step S12.
[0019]
FIG. 4 and FIG. 5 are configuration diagrams showing fourth and fifth embodiments of the present invention, respectively.
When the configuration is as shown in FIGS. 4 and 5, the operation of the flowchart in FIG. 1 is the same as that described above from S1 to S10. In step S11, the optical sensor circuit is driven, and the ambient brightness is maximized. Sometimes, the cutoff is performed in step S12, or the sound collection circuit is driven in step S11, and the cutoff output is performed in step S12 when the surrounding audio signal exceeds a certain threshold.
[0020]
【The invention's effect】
According to the present invention, the shut-off for stopping the gas usage after detecting the voltage drop of the gas meter using the processing device is performed in consideration of the temperature characteristics of the battery, so that the risk of the shut-off becoming impossible can be avoided, and the security can be prevented. The advantage that the property can be improved is obtained.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a first embodiment of the present invention.
FIG. 2 is a configuration diagram showing a second embodiment of the present invention.
FIG. 3 is a configuration diagram showing a third embodiment of the present invention.
FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.
FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.
FIG. 6 is an explanatory diagram of a temperature characteristic example of a battery.
FIG. 7 is a configuration diagram showing a conventional example of a gas meter using a processing apparatus.
FIG. 8 is an explanatory diagram of an example of a battery capacity detection method in FIG. 7;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Processing device (microcomputer), 2 ... Lithium battery, 3 ... pseudo load, 4 ... Voltage detection circuit, 5 ... Shutoff valve, 6, 7, 8, 14, 15 ... Transistor, 9 ... Flow rate sensor, 10 ... Pressure Sensor, 11: seismic sensor, 12: display / notification means, 13: A / D converter, 14: temperature sensor, 15: phototransistor, 16: amplifier, 17: condenser microphone.

Claims (5)

A processing device, a shut-off valve, a pseudo load equivalent to the shut-off valve, a voltage detection unit, a display / notification unit, a clock, and a battery as a power supply. After judging the voltage drop and detecting the battery voltage drop, only for a certain period in consideration of the replacement period of the gas meter using the processing device, in the gas meter using the processing device that enables the gas,
Providing a period monitoring means for monitoring the certain period, after the certain period has elapsed, referring to the current time, selecting a time period during which the daytime temperature is high, and closing the shutoff valve during this time period. A gas shut-off method when the voltage of a gas meter drops using a characteristic processing device. A processing device, a shut-off valve, a pseudo load equivalent to the shut-off valve, a voltage detection unit, a display / notification unit, a clock, and a battery as a power supply. After judging the voltage drop and detecting the battery voltage drop, only for a certain period in consideration of the replacement period of the gas meter using the processing device, in the gas meter using the processing device that enables the gas,
A voltage monitoring unit capable of monitoring the open-circuit voltage of the battery by an analog amount and a period monitoring unit for monitoring the certain period are provided, and after the certain period has elapsed, the time when the open-circuit voltage of the battery is at a maximum. A gas shut-off method at the time of a voltage drop of a gas meter using a processing device, wherein a band is selected and the shut-off valve is closed during this time. A processing device, a shut-off valve, a pseudo load equivalent to the shut-off valve, a voltage detection unit, a display / notification unit, a clock, and a battery as a power supply. Judgment of the voltage drop, after detecting the battery voltage drop, only for a certain period in consideration of the replacement period of the gas meter using the processing device, in a gas meter using a processing device that enables gas,
A temperature sensor capable of monitoring the ambient temperature of the gas meter using the processing device in an analog amount, and a period monitoring means for monitoring the certain period of time are provided. A gas shut-off method at the time of a voltage drop of a gas meter using a processing device, wherein a time zone is selected and the shut-off valve is closed during this time zone. A processing device, a shut-off valve, a pseudo load equivalent to the shut-off valve, a voltage detection unit, a display / notification unit, a clock, and a battery as a power supply. Judgment of the voltage drop, after detecting the battery voltage drop, only for a certain period in consideration of the replacement period of the gas meter using the processing device, in a gas meter using a processing device that enables gas,
An optical sensor and an amplifier circuit capable of monitoring the brightness around the gas meter using the processing device by an analog amount, and a period monitoring unit for monitoring the certain period are provided, and after the certain period has elapsed, the ambient brightness select the time zone the highest, gas shut-off system when the voltage drop of the gas meter using a processing apparatus characterized by closing the shutoff valve during this time. A processing device, a shut-off valve, a pseudo load equivalent to the shut-off valve, a voltage detection unit, a display / notification unit, a clock, and a battery as a power supply. Judgment of the voltage drop, after detecting the battery voltage drop, only for a certain period in consideration of the replacement period of the gas meter using the processing device, in a gas meter using a processing device that enables gas,
A microphone and an amplifier circuit capable of monitoring an audio signal around a gas meter using the processing device in an analog amount, and a period monitoring unit for monitoring the certain period are provided. A gas shut-off method at the time of a voltage drop of a gas meter using a processing device, wherein a time zone in which the surrounding audio signal is highest is selected, and the shut-off valve is closed in this time zone.

Images