JPS6367098B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fuel cutoff control device that cuts off fuel using a self-holding cutoff valve.

Conventional configurations and their problems Conventionally, there have not been many fuel cutoff control devices using self-holding electromagnetic valves that take measures against cutoff failures.

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. Under normal conditions, the valve is held open by a magnet, and when the shutoff is shut off, a predetermined amount of time is used. Simply apply a voltage with a pulse width to generate a reverse magnetic field of the magnet to close the valve. Therefore, if the drive signal is applied only once, there is a risk that the shutoff will fail, and in that case, it will not be possible to prevent a gas leakage accident.

OBJECTS OF THE INVENTION The present invention aims to prevent failure of the fuel cutoff valve to shut off in a fuel cutoff control device having a self-holding shutoff valve.

Structure of the Invention In order to achieve the above object, there is provided a sensor for detecting the flow rate of fuel, a sensor input section for inputting a signal from this sensor, and a drive signal for a shutoff valve in response to a signal from the sensor input section when shutting off. The basic configuration includes a main control section, and with this configuration, it is possible to detect failure of disconnection and perform re-interruption drive.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

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 2 is a sensor provided in the gas meter to measure the flow rate of gas. Reference numeral 1 denotes a sensor input section into which a signal from a sensor 2 is input, and is connected to a main control section 3. Reference numeral 9 denotes a shutoff section, which is a self-holding shutoff valve, and closes the gas flow path when shut off. sensor 2
For example, the gas meter B is composed of a magnet attached to a membrane plate 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.
The main control section 3 drives the cutoff section 9 for a predetermined period of time when the number of pulses from the sensor input section in 30 seconds, for example, exceeds a predetermined number of pulses, that is, the amount of gas passing through. After driving the cutoff section 9, a cutoff signal is outputted to the cutoff section again in response to the signal from the sensor input section 1. That is, the signal from the flow sensor is used for flow rate measurement, failure detection, and re-shutoff timing. In this way, the control device that prevents the self-holding shutoff valve from failing to operate can be used with confidence even if the installation location is far away (outdoors) and prevent accidents due to failure of shutoff.

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. 4 is a pulse counting section consisting of a counter, which integrates the number of pulses from the sensor input section 1. A timer section 5 determines the counting time of the pulse counting section, and clears the pulse counting section 4 every counting time. Reference numeral 6 denotes a clock generating section which serves as a reference clock together with the timer section 5.
7 is an AND circuit which sends a signal to the valve drive unit using the signal from the sensor input unit during the shutoff. 8 is a valve driving section, which is connected to the pulse counting section 4 or the AND circuit 7.
For example, a monostable multivibrator sends a signal for a certain period of time to the cutoff section 9. 10 is a power supply section consisting of a battery, and 11 is a NOR circuit.

The operation of the above configuration will be explained with reference to the operation timing chart of FIG. The pulse counter (PCLR) clears the pulse counter 4 at every counting time determined by the clock generator 6 and timer 5 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.

A predetermined number of pulses (in the example, N
=32), the output of the pulse counting section 4 becomes HI as shown in FIG. 3 (PVOUT). At the rising edge of this voltage, the valve drive section 8 in FIG. 2 outputs a constant cutoff valve drive pulse to the cutoff section 9 using a monostable multivibrator. (T ₁ in Figure 3). At this time, the timer section 5 interrupts counting by the NOR circuit 11. When a signal is input from the sensor input section 1 even though the valve drive section 8 has issued a cutoff output, the AND circuit 7 sends a signal to the valve drive section 8 and the cutoff section 9 is driven. (T ₂ in Figure 3).
In this way, it is possible to prevent failure of the shut-off section 9 to shut off.

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. Counters 12 and 14 can accumulate the number of pulses input to the IN terminal, and can also clear the number of pulses at the CLR terminal. Reference numerals 13, 15, and 16 are monostable multivibrators that output signals for a certain period of time at the rising edge of the voltage applied to the I input terminal. 17
is part of a self-retaining shutoff valve, showing the coil and plunger.

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

1 Once the cutoff signal has been output, if the signal from the sensor input section indicates that there is a flow rate, the cutoff signal is output again, so the operating status of the cutoff section can be confirmed by the flow rate sensor signal. This prevents failure of shutoff.

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

3 After the cut-off part operates normally based on the cut-off signal, the cut-off signal output is stopped.
It is possible to reduce power consumption and is very effective in a dry cell battery power cutoff device.

[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. 1...Sensor input section, 2...Sensor, 3...
...Main control section, 9...Shutoff 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 detected and determines that it is abnormal if the proper usage conditions are deviated from, and issues a closing signal to the shut-off section. A fuel cutoff control device that operates the cutoff section again when the device detects a flow rate.