JPS6367097B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fuel cutoff control device that uses a battery as a power source and shuts off a fuel flow path using a self-holding cutoff valve.

Conventional configurations and their problems Conventional fuel cutoff control devices that use batteries and self-holding electromagnetic valves have not yet taken measures against cutoff failures that take battery power consumption into consideration.

The function of this fuel cut-off control device is to install it at the entrance of the gas supply line, for example, as seen in gas meters in each home, and automatically cut off the fuel when it is determined that there is an abnormality based on the flow rate, such as when there is a continuous flow of gas. This is to cut off the supply route. This type of device is installed in a remote location (outdoors) and cannot promptly transmit information to the user when the shutoff valve is activated, so failure to shut off must be prevented. However, in this type of shutoff device that uses battery power, a self-holding shutoff valve is used to save battery consumption, and under normal conditions, a magnet is used to keep the valve open and when shutting off. Simply apply a voltage with a predetermined pulse width to generate a reverse magnetic field of the magnet to close the valve. Therefore, if the drive signal is issued only once, there is a risk that the cutoff will fail, and if the drive signal is output many times, the life of the battery will be shortened.

OBJECTS OF THE INVENTION An object of the present invention is to prevent power consumption due to unnecessary shutoff operations and shut off the fuel again when shutoff fails in a fuel cutoff control device having a dry battery power source and a self-holding shutoff valve.

Structure of the Invention In order to achieve the above object, a sensor that detects the flow rate of fuel, a sensor input section that inputs the signal of this sensor, and when the signal from the sensor input section is shut off, the switch is shut off again when the signal from the sensor input section reaches a predetermined flow rate. The basic configuration includes a main control section that outputs a valve drive signal, and with this configuration, it is possible to detect a failure in shutting off and perform re-shutoff driving in the minimum necessary number of times.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1.

In FIG. 1, A is a flow path for gas, which is fuel;
B is a gas meter provided in the middle of the gas flow path, and 1 is a sensor provided in the gas meter to measure the flow rate of gas. Reference numeral 2 denotes a sensor input section that inputs the signal from the sensor 1, and is connected to the main control section 3. Reference numeral 4 denotes a shutoff section, which is a self-holding shutoff valve, and closes the gas flow path when shut off. The sensor 1 includes, for example, a magnet attached to a membrane plate constituting the gas meter B, and a reed switch that detects the magnetic field and outputs an electric signal. The membrane plate operates according to the flow rate, and the reed switch is turned on and off according to the movement of the membrane plate. Therefore, the time from one turn on of the reed switch to the next on is the time required for the membrane plate to go back and forth, and the flow rate per unit time can be determined by the amount of gas passing through the meter in the membrane plate and back trip.
In the main control of No. 3, for example, when the number of pulses from the sensor input section in 30 seconds exceeds the first predetermined number of pulses, that is, the amount of gas passing through, the cutoff section 4 is driven for a predetermined time. After driving the cutoff section 4, the number of pulses from the sensor input section 2 becomes the second
The cutoff section 4 is driven again only when the predetermined number of pulses (at any given time) is exceeded, that is, when the amount of passing gas is exceeded even after the cutoff section is driven. Therefore, in a device that detects failure of shutoff based on the flow rate of fuel after shutoff, if the flow rate after shutoff is about the leakage flow rate of the shutoff part (around the allowable value), the shutoff will not be re-shutoff, resulting in unnecessary shutoff. battery consumption can be prevented. Additionally, although this is not illustrated, for example, if the cause of the shutoff is displayed on some kind of display, this can also prevent the content of the shutoff cause display from disappearing due to battery consumption due to unnecessary shutoffs. .

FIG. 2 is a detailed block diagram of the schematic configuration diagram of FIG. 1. In FIG. 2, the same parts as in FIG. 1 are designated by the same numbers. Reference numeral 6 denotes a first pulse counting section consisting of a counter, which integrates the number of pulses from the sensor input section 2. A first timer section 7 determines the counting time of the first pulse counting section, and clears the first pulse counting section 6 every counting time. 8
is a clock generating section which serves as a reference clock for the first timer section 7 and the second timer section 11. 14 is
While the AND circuit is shutting down, the signal from the sensor input section 2 is sent to the second pulse counting section 12.
13 is an AND circuit which sends the signal from the clock generator 8 to the second timer 11 during the cut-off period. Reference numeral 12 denotes a second pulse counting section consisting of a counter, which integrates the number of pulses from the sensor input section 2 through an AND circuit 14 during interruption. A second timer section 11 determines the counting time of the second pulse counting section, and clears the second pulse counting section every counting time. 10 is a valve driving section, and the first pulse counting section 6
It is driven by the second pulse counting section 12 and sends a signal for a certain period of time to the cutoff section 4 using, for example, a monostable altivibrator. 5 is a power supply section consisting of a battery, and 9 is a NOR circuit.

The operation of the above configuration will be explained with reference to the operation timing chart of FIG.

The pulse counting section (PCLR) clears the first pulse counting section 6 at every counting time determined by the clock generating section 8 and the first timer section 7 shown in FIG. The pulse interval of the PIN of the pulse counter in FIG. 2 differs depending on the flow rate, as shown in the pulse counter (PIN) in FIG. 3. If a predetermined number of pulses (for example, N=32) is exceeded within the counting time, the output of the first pulse counting section 6 becomes HI as shown in FIG. 3 (PVOUT). At the rising edge of this voltage, the valve drive section 10 shown in FIG. 2 operates, and the monostable multivibrator outputs a cutoff valve drive pulse to the cutoff section 4 for a certain period of time. (T ₁ in Figure 3). At this time, the first timer section 7
Counting is interrupted by NOR circuit 9. If a signal is input from the sensor input section 2 even though the valve driving section 10 has issued a shutoff output, the second pulse counting section counts the pulses. If the predetermined number of pulses is exceeded within the counting time of the second timer section 11, the output of the second pulse counting section 12 will be PVOUT ₂ in Figure 3.
HI output is output as shown in . At the rising edge of this voltage, the valve drive unit 10 in FIG. 2 operates again.
Outputs the number of cutoff valve driving pulses to the cutoff unit 4 for a certain period of time. (T ₂ in Figure 3) In this way, the signal from the flow rate sensor is used to measure the flow rate and detect failure of shutoff, and also to measure the flow rate even after shutoff, thereby driving the self-holding shutoff valve. Not only can failure be prevented, but also rapid battery consumption can be prevented.

FIG. 4 shows a specific embodiment of FIG. 3. In FIG. 4, the same numbers as those in FIG. 3 are given to the same contents. 15, 17,
Counters 21 and 22 can accumulate the number of pulses input to the IN terminal, and can also clear the number of pulses at the CLR terminal. 16,18,1
Reference numerals 9 and 20 indicate monostable multivibrators which output signals for a certain period of time at the rising edge of the voltage applied to the I input terminal. Reference numeral 23 indicates a coil and a plunger, which are part of a self-holding shutoff valve.

Effects of the Invention As described above, the fuel cutoff control device of the present invention provides the following effects.

(1) Even after the cutoff signal has been output, if the signal from the sensor input section exceeds a predetermined flow rate, the cutoff signal is output again. The operating state is confirmed by the flow rate sensor signal, and failures in shutoff can be prevented.

(2) Since the signal from the flow rate sensor is also used as a re-shutoff signal, there is no need to provide a separate sensor for detecting shutoff failure, and the configuration is therefore simplified.

(3) Since the system will not shut off again even if there is a small amount of leakage in the shutoff valve, which does not cause any trouble, the number of unnecessary shutoff outputs can be reduced and battery consumption can be prevented.

(4) After the cut-off part operates normally based on the cut-off signal, the cut-off signal output is stopped.
Lower power consumption can be achieved.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a fuel cutoff control device according to an embodiment of the present invention, Fig. 2 is a block diagram thereof, Fig. 3 is a timing chart explaining the operation of Fig. 2, and Fig. 4 is a diagram of Fig. 3. FIG. 2...Sensor input section, 3...Main control section, 4...
...Shutoff section, 5...Power supply section.

Claims (1)

[Claims] 1. A flow measuring device installed in the gas supply line, a shutoff section that is kept open by the suction force of a magnet and closed by pulse input, and proper gas usage conditions are memorized in advance, and the gas is sent from the flow measuring device. and a main control section that determines the usage state based on the flow rate signal that is detected, determines that it is abnormal if the proper usage conditions are deviated, and issues a closing signal to the shutoff section, wherein the flow rate measuring device A fuel cutoff control device that operates the cutoff section again when a flow rate from the fuel cell is detected to be above a certain level.