JP3690333B2 - Gas meter control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas meter control device that performs opening / closing control of a gas cutoff valve mounted on a gas meter or the like.
[0002]
[Prior art]
In recent years, gas meters installed in homes are security functions that automatically shut off gas in the event of an emergency, as well as measuring the amount of gas used, as well as the occurrence of earthquakes and the use of gas by the microcomputer. Is installed so that gas can be used safely and with peace of mind.
[0003]
Conventionally, this type of gas meter or the like is equipped with a solenoid type gas shut-off valve having a self-holding function with an electric pulse signal, and is controlled by a battery power source together with an electronic circuit including a microcomputer. In an emergency, the gas shut-off valve is closed with an electric pulse signal output from the microcomputer, and the plug is opened with an electric pulse signal output from the microcomputer in the same manner as when the plug is closed by remote operation by a return button switch or communication control. What was controlled was mainstream.
[0004]
[Problems to be solved by the invention]
However, the conventional gas meter control device has the following problems. In other words, the solenoid type shut-off valve having a self-holding function with an electric pulse signal has a problem that it is easy to close by an external impact, etc., whereas the pulse motor type gas shut-off valve has an advantage of being resistant to impact. When a microcomputer causes a program runaway, it has been a challenge to shut down security.
[0005]
[Means for Solving the Problems]
The present invention includes a pulse motor Shikiga scan shutoff valve that is unplugging-plugging a pulse motor, a pulse motor driving means for driving the pulse motor type gas shut-off valve in the control signal of the microcomputer, the operation of the pre-Symbol microcomputer At the same time as disconnecting the pulse motor control signal from the microcomputer when the runaway monitoring means to monitor , the two-phase excitation pulse generation circuit means activated by the output of the runaway monitoring means, and the runaway monitoring means output Signal switching means for connecting the two-phase excitation pulse signal from the two-phase excitation pulse generating circuit means to the pulse motor driving means, and when the runaway monitoring means detects a microcomputer runaway, the gas shut-off valve is closed. Thus, safety is improved.
[0006]
Gas meter control device of the present invention, a pulse motor type gas shut-off valve that is unplugging-plugging a pulse motor, a pulse motor driving means for driving the pulse motor type gas shut-off valve in the control signal of the microcomputer, the microcomputers When the runaway monitoring means for monitoring the operation, the two-phase excitation pulse generating circuit means activated by the output of the runaway monitoring means, and the runaway monitoring means emit an output, the pulse motor control signal from the microcomputer is disconnected. At the same time, there is provided signal switching means for connecting the two-phase excitation pulse signal from the two-phase excitation pulse generating circuit means to the pulse motor driving means, and the gas shutoff valve is closed when the runaway monitoring means detects a microcomputer runaway To increase safety.
[0007]
In addition , it is possible to reduce the number of parts and improve reliability by configuring the microcomputer that has a watchdog counter circuit that periodically resets the counter that counts the oscillation clock signal by program control as a runaway monitoring means. Can do.
[0008]
Further , by supplying the circuit power supply of the two-phase excitation pulse generating circuit means and the signal switching means with the output signal from the runaway monitoring means, the current consumption can be reduced and the battery can be used effectively.
[0009]
Furthermore , since the two-phase excitation pulse generation circuit is configured to stop the operation after outputting the number of pulses necessary for closing the pulse motor cutoff valve, the cutoff can be stabilized.
[0010]
【Example】
Embodiments of the present invention will be described below with reference to FIGS.
[0011]
(Example 1)
FIG. 1 is a circuit configuration diagram of a gas meter control device in Embodiment 1 of the present invention, and FIG. 2 is an operation sequence diagram of a pulse motor type shut-off valve.
[0012]
In FIG. 1, 1 is a microcomputer that monitors the signals of flow sensors, pressure sensors, and seismic sensors (none of which are shown), and detects abnormal gas flow, abnormal gas pressure, or earthquake vibration. It has the function of closing the gas shut-off valve. Reference numeral 2 denotes a pulse motor type shut-off valve, which is controlled by a two-phase excitation pulse signal having a 90 ° phase shift. Reference numeral 3 denotes a motor driving means of a pulse motor type shut-off valve, which has a built-in circuit for driving a two-phase motor coil.
[0013]
Reference numeral 4 denotes a microcomputer runaway monitoring means. For example, when the microcomputer normally executes program processing, a pulse signal having a predetermined period is output, and a runaway state is determined by not outputting a predetermined pulse during runaway. Reference numeral 5 denotes a second two-phase excitation pulse output means which is activated by an output signal from the runaway monitoring means 4. Reference numeral 6 denotes signal switching means. When the microcomputer 4 runs away or stops , the pulse control signal path from the microcomputer 4 is disconnected , and the pulse signal of the second two-phase excitation pulse output means 5 is sent to the pulse motor driving means 3. Connected, composed of analog switches . 7 is a Li Chiu beam battery constituting the power supply of the gas meter controller.
[0014]
Next, an operation sequence will be described with reference to FIG. The vertical axis shows circuit signals and the horizontal axis shows time. From t1 to t2, a pulse P1 having a predetermined cycle is output while the microcomputer is operating normally. As an example of the runaway monitoring means 4, the capacitor charging voltage VC is judged to be normal by periodically discharging at P1 before reaching VE, but at time t3, the output of P1 is stopped, so the VC voltage exceeds VE. It will be. This point in time is determined to be a runaway state of the microcomputer, and a runaway detection signal 4a is output.
[0015]
In response to the output of the runaway detection signal 4a, the pulse signal switching means 6 disconnects the two-phase excitation pulse output signals 1a and 1b from the microcomputer and connects to the pulse signals 5a and 5b of the second two-phase excitation pulse output means 5. It is configured.
[0016]
In the gas meter control apparatus configured as described above, when the microcomputer causes an abnormality due to program runaway or the like, the output signal of the microcomputer becomes uncertain, but the second two-phase excitation pulse output is generated by the pulse signal switching means. The pulse motor type shut-off valve can be reliably driven to shut off gas stably.
[0017]
In this embodiment, the two-phase excitation pulse generation circuit may stop the operation after outputting the number of pulses necessary for closing the pulse motor cutoff valve.
[0018]
(Example 2)
FIG. 3 is a control configuration diagram of the gas meter control device according to the second embodiment of the present invention.
[0019]
In this embodiment, the runaway monitoring means is composed of a microcomputer 9 incorporating a watchdog counter circuit 8 for periodically resetting a counter for counting the oscillation clock signal of the microcomputer by program control, and a pulse signal switching circuit. A power switch circuit 10 is provided in the phase excitation pulse circuit so that power is supplied only when a signal from the runaway monitoring means is output.
[0020]
【The invention's effect】
As described above, according to the present invention, the output signal of the microcomputer becomes uncertain when the pulse motor type gas cutoff valve runs out of the microcomputer. However, the pulse motor type cutoff valve is reliably driven to stably supply the gas. can be shut off, it is possible to increase the operational reliability of the gas meter control device.
[Brief description of the drawings]
FIG. 1 is a control configuration diagram of a gas meter control device in Embodiment 1 of the present invention. FIG. 2 is an operation sequence diagram of the device. FIG. 3 is a control configuration diagram of a gas meter control device in Embodiment 2 of the present invention. ]
DESCRIPTION OF SYMBOLS 1 Microcomputer 2 Pulse motor type gas shut-off valve 3 Motor drive means 4 Runaway monitoring means 5 Two-phase excitation pulse generation means 6 Signal switching means 7 Lithium battery

Claims (1)

A pulse motor type gas shut-off valve that is unplugging-plugging a pulse motor, a pulse motor driving means for driving the pulse motor type gas shut-off valve in the control signal of the microcomputer runaway monitoring means for monitoring the operation of the pre-Symbol microcomputer Two-phase excitation pulse generation circuit means activated by the output of the runaway monitoring means, and when the runaway monitoring means emits the output, the pulse motor control signal from the microcomputer is cut off at the same time as the two-phase excitation pulse A gas meter control device provided with a signal switching means for connecting a two-phase excitation pulse signal from the generating circuit means to the pulse motor driving means .

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