JP2545607Y2 - Gas leak alarm shutoff device - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention detects a gas leak and issues an alarm,
The present invention relates to a gas leak alarm shut-off device for closing a gas shut-off valve, and more particularly to a gas leak alarm shut-off device for detecting a gas leak by distinguishing a gas supplied through a gas meter from a gas caused by another factor.

[Related Art] Conventionally, as a device for notifying a user of a gas leak, a gas leak alarm device that detects gas by a gas sensor and issues an alarm has been widely used. This gas leak alarm detects mainly LP gas and city gas components used as household fuel, and reacts particularly well with propane and isobutane, which are the main components of LP gas.

Recently, a system (gas leak alarm shutoff device) for shutting off gas at the time of gas leak by combining a gas leak alarm and a gas circuit breaker has also been developed, and its use has begun to spread. This device closes a gas shut-off valve built in a gas meter after a certain period of time (about 40 seconds) has passed since a gas leak was detected.

[Problem to be Solved by the Invention] However, this type of gas leak alarm cutoff device has the following problems. That is, gas leak alarms also respond to insecticide sprays based on isobutane, so using these insecticide sprays indoors can cause the gas leak alarm to give false alarms. Further, the gas leak signal from the alarm device may cause the gas circuit breaker to operate and cause an erroneous shutoff, which is extremely inconvenient.

Further, in the conventional gas leak alarm cutoff device, in order to connect the gas leak alarm and the gas breaker, three systems for a shutoff valve driving coil for driving a gas shutoff valve, a flow sensor, and an answer switch are required. . In this case, the number of signal lines is increased to four or more, the connection is easy to make mistakes, and the construction cost is high.

The present invention has been made in view of such circumstances,
The purpose is to prevent a false alarm and a false cutoff caused by spraying of a pesticide or the like, and to facilitate a connection between the gas leak alarm and the gas breaker. Is to provide.

[Means for Solving the Problems] The gist of the present invention is to compare and detect the detection output of the gas sensor with various operation signals of the gas meter (indicating the use state of the gas, the open / close state of the gas cutoff valve, etc.), Leak detection is performed separately from gas detection by insecticide spray or the like.

That is, the present invention provides a gas leak alarm shut-off that includes a gas leak alarm that detects a gas leak and issues an alarm, and a gas circuit breaker that shuts off gas supply according to a signal supplied from the gas leak alarm. In the apparatus, the gas circuit breaker is connected between two terminals connected to the gas leak alarm, and a shutoff valve driving coil for closing a gas shutoff valve when a voltage between the terminals becomes a predetermined value or more, and gas is supplied. A first switch (meter pulse contact) that turns on when in the state, a first resistor connected between the two terminals via the switch, and a second switch that turns on when the gas shutoff valve is closed. A gas leak detector for detecting a gas leak based on an output of a gas sensor, comprising a switch (valve answer contact) and a second resistor connected between the two terminals via the switch. Detection circuit A gas supply detection circuit that detects a gas supply state based on a voltage between two terminals of the gas circuit breaker, a shutoff valve open / close detection circuit that detects an open / closed state of a gas cutoff valve based on a voltage between the two terminals, A judgment circuit for judging a gas leak, presence or absence of gas supply, and an open / closed state of a shut-off valve based on a detection output of each detection circuit; an alarm generation circuit for issuing an alarm according to the judgment result of the judgment circuit; A DC voltage lower than the threshold value of the shut-off valve drive coil is generated, and when the determination circuit determines that both gas leakage and gas supply are present, a DC voltage higher than the threshold value of the shut-off valve drive coil And a signal generation circuit for supplying the voltage between the two terminals.

[Operation] In general, when supplying gas to a house, the gas is supplied from a gas supply pipe or a gas cylinder through a gas meter. The gas meter is for measuring the amount of gas used and charging the fee, and is installed in most cases. Here, when a gas leak occurs in the house, the leaked gas has passed through the gas meter, so that the gas meter naturally operates. On the other hand, even if an insecticide spray is used,
Of course, the gas meter does not work. That is, if both the operation signal of the gas meter (indicating the gas supply state) and the detection signal of the gas sensor are monitored, it is possible to determine whether or not the gas detection is based on insecticide spray or the like. If an alarm is issued and the gas shutoff valve is closed only when both signals are detected, it is possible to prevent erroneous alarm and erroneous shutoff.

Further, in the present invention, since the gas leak alarm and the gas circuit breaker are configured as described above, it is sufficient to connect the gas leak alarm and the gas circuit breaker with two wires. Therefore, the possibility of erroneous connection can be reduced, and the construction cost can be reduced.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a basic configuration of a gas leak alarm cutoff device according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a gas leak alarm installed at a predetermined position in a room, 2 denotes a gas circuit breaker incorporated in a gas meter, and 3 denotes a gas shut-off valve installed in the gas meter. The basic operation is the same as that of the related art. When a gas leak is detected by the gas leak alarm 1, a shut-off valve driving coil (not shown) is driven by the gas circuit breaker 2, whereby the gas shut-off valve 3 is operated. Closed.

Next, a specific configuration of the present embodiment will be described with reference to FIGS.

FIG. 2 is a circuit configuration diagram showing a specific configuration of the gas circuit breaker 2. As shown in FIG. This circuit is connected to the gas leak alarm 1 at two terminals A and B. A shut-off valve driving coil 21 for driving the gas shut-off valve 3 is connected between these terminals A and B. A first resistor 23 is connected between the terminals A and B via a meter pulse contact (first switch) 22 and a second resistor is connected via a valve answer contact (second switch) 24. Body 25
Is connected. Here, the meter pulse contact 22 is repeatedly turned on and off by the operation of the gas meter (at the time of gas supply). The valve answer contact 24 is turned on when the gas shutoff valve 3 is closed.

FIG. 3 is a block diagram showing a specific configuration of the gas leak alarm. In the figure, reference numeral 31 denotes a power supply circuit for obtaining a DC power supply from a commercial AC power supply, and a DC current is supplied from the power supply circuit 31 to each unit. Reference numeral 32 denotes a gas sensor for detecting gas. The detection signal of the gas sensor 32 is amplified through an amplifier circuit 33 and then supplied to a gas leak detection circuit 34. The gas leak detection circuit 34 detects the presence or absence of gas leak from the gas detection output, and the detection output of the detection circuit 34 is supplied to the determination circuit 35.

A signal generating circuit 36 generates a constant DC voltage at normal times. This DC voltage is transmitted to the two terminals A and B of the gas circuit breaker 2 by the transmission / reception circuit 37. In the transmission / reception circuit 37, a signal from the gas circuit breaker 2 is received. After the received signal is separated by the signal separation circuit 38, it is supplied to the meter pulse reception circuit 39 and the valve answer circuit 40. The meter pulse receiving circuit 39 detects the gas use state, and the valve answer receiving circuit 40 detects the open / close state of the gas cutoff valve. Then, these detection signals are supplied to the determination circuit 35.

The determination circuit 35 is composed of, for example, an operational amplifier capable of detecting three levels, and the determination circuit 35 determines the current state based on the input signals. In particular,
A normal state, a gas leak and no gas supply state, a gas leak and a gas supply state, and a gas shutoff valve open / close state are determined. When it is determined that the gas is leaking and the gas is supplied, the shutoff instruction circuit 41 is provided.
Sends a cutoff instruction signal to the signal generation circuit 36. Then, a cutoff signal is output from the signal generation circuit 36, and the cutoff signal is transmitted to the gas circuit breaker 2 via the transmission / reception circuit 37. When the determination circuit 35 determines that the gas shutoff valve is closed, the alarm instruction circuit 42 outputs a buzzer circuit 43 and a lamp circuit 44.
Is sent out. Then, a buzzer is called by the buzzer circuit 43, and the lamp is turned on or blinked by the lamp circuit 44.

Next, the operation of the above-configured device will be described.

First, the signal generation circuit 36 normally generates a DC voltage of +5 V, and this DC voltage is supplied to the two terminals A and B of the gas circuit breaker 2 through the transmission / reception circuit 37. Here, the resistance value L of the shut-off valve driving coil 21 is 30Ω, and the resistance value R ₃ of the resistor 26 from the signal generation circuit 36 to the terminal A of the gas circuit breaker 2 is 120.
Ω, the resistance value R1 of the _first resistor 23 is 70Ω, and the second resistor 25 is
The resistance value R ₂ is set to 30 [Omega. Then, the terminal A
A DC voltage (+1 V) as shown in FIG.
The voltage level at this time is set lower than the threshold value of the shut-off valve driving coil 21 so that the gas shut-off valve 3 does not operate.

When gas is used, the meter pulse contact 22 of the gas meter with a built-in shut-off valve repeatedly turns on and off. here,
When the meter pulse contact 22 is on, the voltage is divided by the action of the resistor 23, and the voltage at the terminal A decreases as shown in FIG. 4 (b). This voltage value is supplied to the determination circuit 35 via the signal classification circuit 38 and the meter pulse reception circuit 39.

If the gas leaks, the judgment circuit 3 is passed through the gas sensor 32, the amplification circuit 33 and the gas detection circuit 34 of the gas alarm 1.
5 is supplied with a gas leak signal. Here, the judgment circuit 35
When receiving the gas leak signal and receiving the signal indicating that the gas is being used, the controller sends a signal to the shutoff instruction circuit 41 and the alarm instruction circuit 42.

The cutoff instruction circuit 41 receives the signal from the determination circuit 35 and instructs the signal generation circuit 36 to cut off. When this signal is input, the signal generation circuit 36 generates a voltage signal obtained by superimposing a rectangular pulse on the DC voltage for a certain period of time, and transmits this signal to the transmission / reception circuit 37.
To the terminal A of the gas circuit breaker 2. At this time, the signal obtained at the terminal A is a rectangular pulse having a low level of +1 V and a high level of +2 V, as shown in FIG. The voltage is higher than the threshold value of 21.

The gas meter with the shut-off valve receives this signal and closes the gas shut-off valve 3. At this time, since the valve answer contact 24 is turned on, the signal of FIG. 4A becomes as shown in FIG. Once closed, the gas shutoff valve 3 remains closed unless manually restored. The signal shown in FIG. 4D is supplied to the determination circuit 35 via the transmission / reception circuit 37 and the valve answer reception circuit 40. When this signal is received by the judgment circuit 35, an alarm instruction signal is transmitted from the alarm instruction circuit 42, whereby an alarm is issued and the lamp is turned on or blinked.

As described above, in the present embodiment, the alarm is generated and the gas is shut off only when a gas leak occurs when the gas is used, so that the erroneous alarm and the erroneous shut off due to the use of the insecticide spray or the like can be eliminated. Therefore, the reliability of the alarm device can be improved, and the usability can be improved. Moreover, the gas leak alarm 1 and the gas circuit breaker 2
And only two signal lines are required, and a flow rate signal and a valve answer signal can be obtained, and a cutoff pulse can be monitored and controlled. For this reason, erroneous connections are reduced, and construction costs can be reduced.

The present invention is not limited to the embodiment described above. In the embodiment, the gas shutoff valve is closed when it is determined that both the gas leakage and the gas supply are present. However, the gas shutoff valve may be closed after a lapse of a predetermined time from this determination. In this case, malfunction due to instantaneous gas leak detection due to insecticide spray or the like when using gas can be eliminated. Further, the voltage level value and the pulse width shown in FIG. 4 can be appropriately changed according to the specifications. In addition, various modifications can be made without departing from the scope of the present invention.

[Effects of the Invention] As described in detail above, according to the present invention, the detection output of the gas sensor and the operation signal of the gas meter are compared and collated, thereby preventing false alarms and erroneous shutoff due to insecticide spray or the like. It is possible to realize a highly reliable gas leak alarm cutoff device. Also, the gas leak alarm and the gas circuit breaker can be connected with two wires,
These connections can be facilitated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a gas leak alarm cutoff device according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing a specific configuration of a gas circuit breaker used in the above device, and FIG. FIG. 4 is a block diagram showing a specific configuration of a gas leak alarm used in the above device, and FIG. 4 is a signal waveform diagram for explaining the operation of the above device. DESCRIPTION OF SYMBOLS 1 ... Gas leak alarm device, 2 ... Gas circuit breaker, 3 ... Gas shutoff valve, 21 ... Shutoff valve drive coil, 22 ... Meter pulse contact (first switch), 23 ... First resistor, 24 ... Valve answer Contact point (second switch), 25: second resistor, 32: gas sensor, 34: gas leak detection circuit, 35: determination circuit, 36: signal generation circuit, 43: buzzer circuit, 44: lamp circuit.

Claims (2)

(57) [Scope of request for utility model registration] 1. A gas leak alarm shutoff comprising: a gas leak alarm which detects a gas leak and issues an alarm; and a gas circuit breaker which shuts off gas supply in accordance with a signal supplied from the gas leak alarm. In the apparatus, the gas circuit breaker is connected to the gas leak alarm device 2
A shut-off valve drive coil that is connected between the terminals and closes the gas shut-off valve when the voltage between the terminals is equal to or higher than a predetermined value, a switch that is turned on when the gas is supplied, and between the two terminals through this switch. A gas leak detector that detects a gas leak based on an output of a gas sensor, and detects a gas supply state based on a voltage between two terminals of the gas circuit breaker. A gas supply detection circuit, a determination circuit that determines the presence or absence of gas leakage and the presence or absence of gas supply based on the detection output of each of the detection circuits, an alarm generation circuit that issues an alarm according to the determination result of the determination circuit, At this time, a DC voltage lower than the threshold value of the shut-off valve driving coil is generated. When the determination circuit determines that both gas leakage and gas supply are present, the threshold of the shut-off valve driving coil is generated. A signal generating circuit for generating a DC voltage higher than the value and supplying the voltage between the two terminals. 2. A gas leak alarm interrupter comprising: a gas leak alarm which detects a gas leak and issues an alarm; and a gas circuit breaker which shuts off gas supply in accordance with a signal supplied from the gas leak alarm. In the apparatus, the gas circuit breaker is connected to the gas leak alarm device 2
A shut-off valve drive coil connected between the terminals and closing the gas shut-off valve when the voltage between the terminals becomes equal to or higher than a predetermined value; a first switch which is turned on when the gas is supplied; and a first switch. A first resistor connected between the two terminals, a second switch that is turned on when the gas shut-off valve is closed, and a second switch connected between the two terminals via the second switch. A gas leak detection circuit configured to detect a gas leak based on an output of a gas sensor, and a gas supply configured to detect a gas supply state based on a voltage between two terminals of the gas circuit breaker. A detection circuit, a shutoff valve opening / closing detection circuit for detecting the open / closed state of the gas shutoff valve based on the voltage between the two terminals, Judgment to determine the status A circuit, and an alarm generation circuit that issues an alarm according to the determination result of the determination circuit,
Normally, a DC voltage lower than the threshold value of the shut-off valve drive coil is generated. When the determination circuit determines that both gas leakage and gas supply are present, the DC voltage is lower than the threshold value of the shut-off valve drive coil. A signal generating circuit for generating a high DC voltage and supplying the voltage between the two terminals.