JP2531047Y2 - 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,
An object of the present invention is to provide a gas leak alarm shutoff device which can prevent erroneous shutoff due to insecticide spray or the like and can facilitate connection between a gas leak alarm and a gas breaker. It is in.

[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 device, and a shut-off valve driving coil for closing a gas shut-off valve when a voltage between the terminals becomes a predetermined value or more, A gas flow switch inserted between one of the terminals and the shut-off valve driving coil, which repeats on-off when gas is supplied, wherein the gas leak alarm device detects a gas leak based on an output of a gas sensor. A gas leak determination circuit for determining, a warning circuit for issuing an alarm when the determination circuit determines that there is a gas leak, and a DC voltage lower than a threshold value of a shutoff valve driving coil between two terminals of the gas circuit breaker. A pull-up circuit for applying pressure, a chattering prevention circuit for converting a change in voltage between two terminals due to on / off of a gas flow switch of the gas circuit breaker into a rectangular pulse, and a gas leak determination circuit indicating that there is a gas leak. A counting circuit that counts pulses from the chattering prevention circuit in the determined state, and outputs a shutoff instruction signal when the count value becomes equal to or greater than a certain value, and a certain time during which the gas leak determination circuit determines that there is gas leakage. A timer circuit that outputs a shutoff instruction signal later, and a shutoff signal from the integrating circuit or the timer circuit are input, and a shutoff pulse voltage higher than a threshold value of the shutoff valve driving coil is generated,
The circuit comprises a cut-off pulse generating circuit for supplying the cut-off pulse voltage between two terminals of the gas circuit breaker, and a reset switch for resetting the operation of the integrating circuit and the timer circuit.

[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 the gas shutoff valve is closed only when both signals are detected, erroneous shutoff can be prevented.

Further, when an insecticide spray or the like is used at the time of using the gas, there may be a case where the leak is detected as a gas leak even if the leak is not the original gas leak. In this case, in the present invention, the cutoff pulse is generated when the gas supply amount exceeds a certain value by the integrating circuit, so that the erroneous cutoff can be prevented. That is, the gas detection by the insecticide spray or the like is only for a very short time as compared with the original gas leakage, and the integration circuit does not generate the cutoff pulse in this time.

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 diagram showing a specific configuration of the gas circuit breaker 2. This circuit is connected to the gas leak alarm 1 at two terminals A and B. A shutoff valve driving coil 21 for driving the gas shutoff valve 3 and a gas flow switch (flow rate sensor) 22 are connected in series between these terminals AB. Also, the terminal
Between A and B, protection resistor 23, answer switch 24 and display LE
D25 is connected in series.

Here, the gas flow switch 22 is repeatedly turned on and off by the operation of the gas meter (at the time of gas supply), and the on-off cycle is, for example, 0.7 l. Answer switch 24
Is turned on when the gas shutoff valve 3 is closed, and when the switch 24 is turned on, the LED 25 is turned on. The protection resistor 23, the answer switch 24, and the display LED 25 are not always necessary, and may be omitted.

FIG. 3 is a circuit diagram showing a specific configuration of the gas leak alarm. In the figure, 31 is a surge circuit, 32 is 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 32 to each section. 33 is a gas sensor for detecting gas, and the detection signal of the gas sensor 33 is an amplification circuit.
After being amplified through 34, it is supplied to a gas leak determination circuit 35. The gas leak determination circuit 35 detects the presence or absence of gas leak from the gas detection output, and the determination output of the determination circuit 35 is supplied to the buzzer circuit 37 via the delay circuit 36 and to the lamp circuit 38. You. And the buzzer circuit 37
Generates a buzzer, and the lamp circuit 38 turns on or off the lamp.

Further, the judgment output of the gas leak judgment circuit 35 is a chattering prevention circuit 39, an integrating circuit 40, a timer circuit 41, a transistor Q
₁ to Q _3, diode D ₁ to D _3, resistors R ₁ to R _3, a capacitor
It is supplied to a gas cut-off pulse generating section composed of C ₁ , C ₂ , reset switch SW ₁ , varistor BR ₁ , AND gates AND ₁ , AND ₂ and OR gates OR ₁ , OR ₂ . This gas cutoff pulse generator is connected to the terminals A and B of the gas breaker 2 and receives a gas leak signal from a gas leak determination circuit 35 and the gas breaker 2.
A gas shut-off pulse large enough to drive the shut-off valve coil 21 between the terminals A and B is sent out based on a flow signal obtained from the side via the chattering prevention circuit 39.

Here, D ₂ and R ₃ are for pulling up the terminal A, whereby a constant DC voltage is applied to the terminal A. When the gas flow switch 22 of the gas circuit breaker 2 is turned on,
The voltage at the terminal A is lowered by the voltage drop caused by R _3, the voltage change is detected by the chattering prevention circuit 39. Then, when the flow switch 22 is repeatedly turned on and off in the gas use state, a pulse (flow signal) corresponding to the on and off is supplied from the chattering prevention circuit 39 to the AND ₁ . The the AND ₁ is input is determined output of the gas leak judgment circuit 35, the AND ₁
The flow signal enters the integrating circuit 40 only when gas leaks. Normally (when there is no gas leak), the flow signal is not accepted.

The integrating circuit 40 counts the flow signal, and outputs a shutoff instruction signal to the AND ₂ when the signal reaches a preset value, and is constituted by, for example, a binary binary counter (divided by 16, 32, 64, etc.). . The the AND ₂ is input determination output of the gas leakage determination circuit 35, the the AND ₂ is passed through the output signal of the integrating circuit 40 only when gas leak, and sends the OR _1, OR _2.

The output signal of OR ₁ is supplied to Q ₂ to which will be described later. The output signal of OR ₂ is used as a reset signal as an integrating circuit 40 and a timer circuit 41.
Sent to The timer circuit 41 outputs the shut-off instruction signal OR ₁ after a predetermined time after receiving the gas leak signal from the gas leak determination circuit 35.
To be sent. SW ₁ , C ₂ and R ₂ constitute a reset circuit, and the output of this reset circuit is sent to OR ₂ . Therefore, when the integrating circuit 40 reaches the set value or when the reset switch ₁ is externally pressed, the integrating circuit 40 and the timer circuit 41 are reset. The resetting delays the generation of the cutoff pulse.

R ₁ , C ₁ , and Q _{1 to} Q ₃ constitute a cutoff pulse generation circuit. Since usually C ₁ is not charged, due to noise or the like
Even if Q ₂ and Q ₃ are turned on, no cut-off pulse is generated.
In state C ₁ during a gas leak is charged, when Q ₂ is turned on by the output of OR _1, charge of C ₁ by the conduction of Q ₃ is terminal A
Is supplied to the cutoff valve drive coil 21 as a cutoff pulse voltage. D ₃ and BR ₁ function as output protection circuits.

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

First, when it is determined by the gas leakage determination circuit 35 that there is gas leakage, the lamp L is turned on or flashed by the lamp circuit 38, and the delay circuit 36 and the buzzer circuit 37 call the buzzer B after a certain period of time. Furthermore, as a gate circuit
When AND ₁ and AND ₂ are opened, charging of C ₁ is started.

Here, if no gas is used, the gas flow switch 22 does not repeat on-off, so that the integrating circuit 40 does not count up. Therefore, the integrating circuit 40 does not generate the cutoff instruction signal, and the cutoff pulse generating circuit does not operate. However, long-time timer circuit 41 for safe operates about 5 minutes, then through OR ₁ from the timer circuit 41 Q ₂
Is supplied with a shutoff instruction signal. Note that the timer circuit 41
As long as the gas leakage continues, the cutoff signal is repeatedly generated. Further, the operation of the timer circuit 41 can be reset by operating a reset switch ₁ described later.

On the other hand, if gas is used, the gas flow switch 22 repeatedly turns on and off, and the chattering prevention circuit
The flow signal is transmitted by 39, and counting is started by the integrating circuit 40. Here, when the value reaches a preset value, the integration circuit 40 outputs a cutoff instruction signal. The blocking indication signal Q ₂ is turned on, blocking pulse voltage is generated, the shut-off pulse voltage is supplied to the gas circuit breaker 2 via the terminals A, B. Then, the gas shutoff valve 3 is closed.
In this case, the cutoff timing is not determined by time as in the conventional case, but the cutoff is performed when the gas flow rate reaches a certain value.

At the same time as outputting the cutoff instruction signal from the integrating circuit 40, the integrating circuit 40 is reset via the OR ₂ to prepare for the next count. Normally, once shut off, the flow signal is not received, so the count is not performed.

Further, for example, if the user uses an insecticide spray or the like during normal use of the gas, the gas sensor 33 reacts to the spray, and if left as it is, it is inevitable that the gas sensor 33 will be shut off.
However, rather than gas leakage, if you do not want to be interrupted because during normal use, by pushing the reset SW _1, it is possible to time extension to further cut-off. Since the detection of the gas by the insecticide spray or the like is extremely short, if the gas sensor 33 does not react when the reset switch ₁ is pressed, the gas will not be shut off. SW ₁ is
Since the differentiating circuit is configured together with C ₂ and R ₂ , even if SW ₁ is kept pressed, it is accepted only once, and mischief can be prevented.

As described above, in the present embodiment, the gas shutoff is performed only when a gas leak is detected when the gas is used, so that erroneous shutoff due to the use of a pesticide spray or the like can be eliminated. Therefore, the reliability of the alarm device can be improved, and the usability can be improved. Further, when an erroneous gas leak is detected by using an insecticide spray or the like when using the gas, the user can press the reset switch to prevent the gas shutoff valve from being shut off.

As the gas flow switch and the answer switch, those normally provided in the gas circuit breaker 2 can be used, and the configuration of the gas circuit breaker 2 can be simplified. Moreover,
Only two signal lines are required to connect the gas leak alarm 1 and the gas circuit breaker 2. In this case, a flow signal and a valve answer signal can be obtained, and a monitoring and control of a cutoff pulse can be performed. For this reason, erroneous connections are reduced, and construction costs can be reduced.

Next, another embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to the drawings. FIG. 4 is a circuit diagram showing a specific configuration of the gas circuit breaker 2. This circuit differs from the circuit of FIG. 2 in that a diode having the illustrated polarity is connected in parallel with the flow sensor 22. Further, the protection resistor 23, the answer switch 24, and the surface LED 25 are omitted.

FIG. 5 is a circuit diagram showing a specific configuration of the gas cutoff pulse generator. It is basically the same as FIG. 3, and the difference is in the configuration of the cutoff pulse generation circuit. That is, blocking pulse generating circuit of this embodiment is composed of _{R 1, R 4, C 1} , Q 1 ~Q 3, the emitter of Q ₂ is connected to the collector for Q ₁ through R ₄ instead of ground I have. Then, the reverse voltage generating circuit 42 is connected to the emitter of Q _1. Also diode
D ₁ in the opposite direction to the previous embodiment, the diode D ₃ is removed.

In such a configuration, the cutoff pulse signal
The current flows through the shut-off valve coil 21 in a direction opposite to that of the previous embodiment, and the operation is substantially the same as that of the previous embodiment. Therefore, the same effect as in the previous embodiment can be obtained.

In addition, this embodiment has the following advantages.
That is, in the above embodiment, when the gas leakage is determined and the cutoff pulse is generated, when the flow sensor 22 is open (including a failure), the cutoff is not performed until the flow sensor 22 is turned on. On the other hand, in the present embodiment, since the cutoff pulse is supplied to the coil 21 via the diode 26, the ON-OF
Irrespective of F, it can be reliably shut off.

Note that the present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the gist thereof. For example, the set value of the integrating circuit, the set time of the timer circuit, and the like may be appropriately determined in consideration of safety.
Further, the circuit configuration of the gas cutoff pulse generator shown in FIGS. 3 and 5 can be appropriately changed according to the specifications.

Further, a series circuit of a plurality of diodes 26 may be connected in parallel to the gas flow switch 22 in the first embodiment as shown in FIG. In this case, even if the gas flow switch 22 is open, it can be cut off, and the reverse voltage generating circuit 42 as shown in FIG. 5 is not required.
Further, by connecting a plurality of diodes 26 in series, when the gas flow switch 22 is turned on and off, the terminal A
A voltage of −H is generated, and the gas flow signal can be detected by the chattering circuit 39.

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

[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-described apparatus, and FIGS. 4 and 5 are for explaining another embodiment of the present invention. FIG. FIG. 5 is a circuit configuration diagram showing a specific configuration, FIG. 5 is a block diagram showing a specific configuration of a gas leak alarm, and FIG. 6 is a circuit configuration diagram showing a modification of the present invention. DESCRIPTION OF SYMBOLS 1 ... Gas leak alarm, 2 ... Gas circuit breaker, 3 ... Gas shutoff valve, 21 ... Shutoff valve drive coil, 22 ... Gas flow switch (flow rate sensor), 23 ... Resistor, 24 ... Answer switch, 33 ... Gas sensor, 35: gas leak determination circuit, 36: delay circuit, 37: buzzer circuit, 38: lamp circuit, 39: chattering prevention circuit, 40: integrating circuit, 41: timer circuit, 42: reverse voltage generation circuit.

Claims (3)

(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 2
A shut-off valve driving coil that is connected between the two terminals and closes the gas shut-off valve when the voltage between the terminals becomes equal to or higher than a predetermined value, and is inserted between one of the terminals and the shut-off valve driving coil to supply gas. A gas flow switch that repeats on-off when the gas leak detector is located, the gas leak alarm device determines a gas leak based on the output of the gas sensor, and a gas leak determination circuit determines that there is a gas leak. An alarm circuit for issuing an alarm, a pull-up circuit for applying a DC voltage lower than a threshold value of a shut-off valve driving coil between two terminals of the gas circuit breaker, and an on-off of a gas flow switch of the gas circuit breaker. A chattering prevention circuit for converting a change in voltage between two terminals into a rectangular pulse; and a chattering prevention circuit in a state where the gas leak determination circuit determines that there is gas leakage. An integration circuit that counts the number of pulses and outputs a shutoff instruction signal when the count value exceeds a certain value, and a shutoff pulse that receives the shutoff instruction signal from the integration circuit and is higher than the threshold value of the shutoff valve driving coil. A gas leak alarm cutoff device comprising: a cutoff pulse generating circuit for generating a voltage and supplying the cutoff pulse voltage between two terminals of the gas circuit breaker; and a reset switch for resetting the operation of the integrating circuit. . 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 2
A shut-off valve driving coil that is connected between the two terminals and closes the gas shut-off valve when the voltage between the terminals becomes equal to or higher than a predetermined value, and is inserted between one of the terminals and the shut-off valve driving coil to supply gas. A gas flow switch that repeats on-off when the gas leak detector is located, the gas leak alarm device determines a gas leak based on the output of the gas sensor, and a gas leak determination circuit determines that there is a gas leak. An alarm circuit for issuing an alarm, a pull-up circuit for applying a DC voltage lower than a threshold value of a shut-off valve driving coil between two terminals of the gas circuit breaker, and an on-off of a gas flow switch of the gas circuit breaker. A chattering prevention circuit for converting a change in voltage between two terminals into a rectangular pulse; and a chattering prevention circuit in a state where the gas leak determination circuit determines that there is gas leakage. An integration circuit that counts the number of pulses and outputs a shutoff instruction signal when the count value is equal to or greater than a predetermined value, and a timer circuit that outputs a shutoff instruction signal after a predetermined time period in which the gas leak determination circuit determines that there is gas leak. Receiving a cutoff signal from the integrating circuit or the timer circuit, and generating a cutoff pulse voltage higher than a threshold value of the cutoff valve driving coil;
A gas leak alarm cutoff device comprising: a cutoff pulse generating circuit for supplying the cutoff pulse voltage between two terminals of the gas circuit breaker; and a reset switch for resetting the operation of the integrating circuit and the timer circuit. 3. A shut-off pulse generating circuit, comprising: a capacitor for charging an electric charge when the gas leak judging circuit judges that there is a gas leak; and a shut-off pulse for discharging the electric charge of the capacitor in response to the shut-off instruction signal. 2. The device according to claim 1, comprising a transistor for generating a signal.
Or the gas leak alarm cutoff device according to 2.