JPH0625610B2 - Gas accident prevention device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gas accident prevention device of the present invention for preventing a gas accident caused by the use of a fuel gas such as city gas or propane gas.

2. Description of the Related Art Various measures have been proposed for the purpose of preventing various accidents associated with the use of gas, for example, one shown in FIG.

The gas passage 1 is provided with a flow rate sensor 2 that outputs an electric signal according to the gas flow rate as a flow rate signal. As a typical example of the flow rate sensor 2, there is a magnet configured in a gas flow rate measurement response part of a gas meter and a reed switch for detecting the magnetic field, and the flow rate signal in this case is the on / off state of the reed switch. is there. Further, an abnormality sensor 3 that detects an abnormality such as an earthquake or gas leak and outputs an abnormality signal is provided at an appropriate place. Typical examples of the anomaly sensor 3 include a vibration sensor and a gas leak alarm. The flow rate signal and the abnormality signal are input to the control unit 4. The control unit 4 determines whether or not the interruption is possible based on the input flow rate signal and the abnormality signal, and outputs the interruption signal when the interruption is determined, and the interruption unit 11 operates when the interruption signal is received. A drive unit 6 that outputs a so-called one-shot shutoff signal in the form of a single pulse that drives the shutoff unit 11 only for the time required to shut off the gas passage, and a shutoff that externally indicates that the shutoff state is received by the shutoff signal. A display unit 7, a battery 8 as a power source for the apparatus, a low voltage detection unit 9 which inspects the battery voltage and outputs a display signal when the battery voltage is below a predetermined value, and a low voltage battery when receiving the display signal. It is composed of a low-voltage display unit 10 which is externally displayed. A typical example of the display units 7 and 10 is a light emitting diode. The gas passage 1 is provided with a shut-off portion 11 which receives the one-shot shut-off signal from the drive unit 6 and shuts off the gas passage, and maintains the state even after the one-shot shut-off signal disappears. Since the shutoff unit 11 is made to respond to such a one-shot shutoff signal, it is not necessary to drive the shutoff unit 11 from beginning to end while the shutoff unit 11 is shutting off the gas passage. This is because the consumption of the battery 8 can be reduced as compared with the case where it is necessary to drive all the time during the period. A typical example of the shutoff unit 11 is a self-holding solenoid valve using a magnet, a coil, a spring, and the like.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the gas accident prevention device having such a configuration, the decrease in the battery voltage during the undischarge of the battery 6 is detected and displayed externally. It is expected that people will recognize this and take appropriate measures such as battery replacement. Therefore, if this display is overlooked, the voltage of the battery 6 may continue to drop and it may not be possible to maintain the voltage at which the device normally operates. Such a state is obviously unsafe and is not desirable for the device. In the case of using the light emitting diode for the low voltage display unit 10, since the display is performed only after the voltage of the battery 6 starts to be displayed until the voltage of the light emitting diode drops to a voltage at which the display of the light emitting diode can be maintained, When the voltage becomes lower than the display sustaining voltage, this display disappears and it becomes even more unsafe.

Therefore, the present invention prevents the device from becoming unsafe by blocking the gas passage even when the battery voltage drops.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a low voltage detection unit,
A low voltage cutoff signal is output when the battery voltage drops below a predetermined value, and a low voltage detection circuit is provided to detect a change from the closed state to the open state of the cutoff section and output an open signal. An open circuit breaker is provided which outputs a break signal when a break signal is input in the presence of a break signal, and the driver is turned on when one of the break signal, the low voltage break signal and the break signal is inputted. A shot cutoff signal is output.

Operation According to the present invention, when the low voltage detection unit detects a decrease in the battery voltage, the cutoff signal is output, and the drive unit outputs the one-shot cutoff signal.
The shutoff unit is driven to shut off the gas passage. When the shutoff unit is returned from the closed state to the open state by human power or other means, the open detection unit detects this and outputs the open signal. When the low voltage cutoff signal is present in this state, the open circuit breaker outputs the open circuit break signal, which causes the drive unit to operate and output the one-shot cutoff signal, so that the block circuit blocks the gas passage again. As a result, when the battery voltage becomes equal to or lower than the predetermined value, the one-shot cutoff signal is output from the control unit, and even if the cutoff unit is changed from closed to open in this state, the one-shot cutoff signal is output again and the cutoff unit is cut off. Will continue to shut off the gas passage, preventing the device from becoming unsafe and keeping the shut off.

Embodiment FIG. 1 is a block diagram showing an embodiment of the gas accident prevention device of the present invention. Reference numeral 12 is a control unit which receives the voltage of the cutoff determination unit 5, the cutoff display unit 7, the battery 8 and the battery 8 and outputs a low voltage cutoff signal when the voltage is below a predetermined value. When the closed state is changed to the opened state by a manual operation or the like, the open state detection section 14 that detects the change and outputs the open state signal, and the low voltage detection section 13 outputs the cutoff signal and the open state signal exists. The AND gate 15 as an opening and closing unit that outputs a breaking signal, and a single safety multivibrator 16 as a driving unit that outputs a one-shot breaking signal to which any one of a breaking signal, a low-voltage breaking signal, and a breaking break signal is input. To do. When the shutoff unit 11 is a self-holding solenoid valve, the opening detection unit 14 detects the counter electromotive force because a counter electromotive force is generated in the coil when the shutoff unit 11 is changed from closed to open by manual operation or the like. It can be realized with a circuit.

Next, the operation of this embodiment will be described. When the voltage of the battery 8 becomes equal to or lower than the predetermined value, the low voltage detector 13 outputs a low voltage cutoff signal. By the generation of this low voltage cutoff signal,
The single safety multivibrator 16 is triggered and outputs a one-shot cutoff signal. The shutoff unit 11 shuts off the gas passage 1 by the one-shot shutoff signal. At this time, since the interruption display unit 7 is not driven, the interruption display is not performed outside. After the blocking unit 11 is once in the closed state, when it is returned to the open state by a manual operation or the like, this change is detected by the open detection unit 14, and the open detection unit 14 outputs an open signal. Since the low voltage cutoff signal is maintained, the AND gate 15 outputs the open cutoff signal, the monostable multivibrator 16 is triggered again, the one-shot cutoff signal is output, and the cutoff unit 11 cuts off the gas passage 1 again. To do. Therefore, when the battery voltage drops below a predetermined value, the gas passage 1 is shut off, and even if the shutoff unit 11 is opened again, the one-shot shutoff signal is output from the control unit 12 again, so that the shutoff unit 11 turns off the gas passage. Since 1 is shut off, the shutoff state of the gas passage 1 can be maintained, and the device does not become an unsafe side.

As described above, according to the present invention, when the battery voltage drops, the gas passage is shut off, and even if the gas passage is opened by a manual operation or the like, the shutoff portion operates again to shut off the gas passage. As a result, the gas passage can be maintained in the blocked state, and the device does not become an unsafe side.

[Brief description of drawings]

FIG. 1 is a block diagram of a gas accident prevention device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional gas accident prevention device. 1 ... Gas passage, 2 ... Flow rate sensor, 3 ... Abnormality sensor, 5 ... Shutdown determination section, 8 ... Battery, 11 ... Shutoff section,
12 ... Control part, 13 ... Low voltage detection part, 14 ... Opening detection part, 15 ... Opening interruption part, 16 ... Driving part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadanori Shirasawa, 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Masaaki Sakata, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Tatsuo Fujimoto 1-5-20 Kaigan, Tokyo Minato-ku, Tokyo Gas Co., Ltd. (72) Inventor Tsutomu Otani 1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas Co., Ltd. (56) References JP-A-58-88535 (JP, A) JP-A-60-78216 (JP, A)

Claims (1)

[Claims] 1. A flow rate sensor that outputs a flow rate signal according to a gas flow rate, an abnormality sensor that outputs an abnormality signal when an abnormality such as an earthquake or a gas leak is detected, and a single-shot operation that receives the flow rate signal and the abnormality signal. A control unit that outputs a pulse-shaped cutoff signal; and a cutoff unit that responds to the single-shot pulse-shaped cutoff signal and shuts off the gas passage and maintains the state even after the single-shot pulsed cutoff signal disappears, The control unit determines whether or not to cut off based on the flow rate signal and the abnormality signal, and outputs a cutoff signal at the time of cutoff determination, a battery as a device power supply, and the voltage of the battery is a predetermined value or less. At this time, a low-voltage detection unit that outputs a low-voltage cutoff signal, an open-circuit detection unit that detects a change from the closed state to the open state of the cut-off unit and outputs an open-circuit signal, and a low-voltage cutoff signal is output from the low-voltage detection unit. Has been In the state, when the opening signal is input from the opening detection unit, the opening cutoff unit that outputs the opening cutoff signal, the cutoff signal from the cutoff determination unit, the low voltage cutoff signal from the low voltage detection unit, the open cutoff unit A gas accident prevention device including a drive unit that outputs a single-shot pulse-shaped cutoff signal to the cutoff unit when any of the open cutoff signals from the unit is input.