JPH0759977B2 - Gas alarm shutoff system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a gas leak alarm device, a gas meter, and a gas alarm shutoff system having a gas shutoff valve, and more particularly to a gas leak alert device and a gas meter. Connect with the signal line of the book,
The present invention relates to a gas alarm cutoff system in which signals are transmitted and received between a gas leak alarm device and a gas meter through the two signal lines.

[Conventional technology]

A conventional system of this type is, for example, Japanese Patent Laid-Open No. 62-214499.
The one shown in FIG. 10 disclosed in the publication is known.

In the conventional example shown in FIG. 10, the gas meter 1 and the gas leak alarm device 2 are interconnected by two signal lines X and Y, and a gas leak detection circuit gas leak (not shown) is provided in the gas leak alarm device 2. A photocoupler 3 including an LED 3a, which is a light emitting element that is driven to turn on by a detection signal generated when it is detected, and a phototransistor 3b that is a light receiving element that is turned on when the LED 3a is turned on, and a signal line X from the gas meter 1 side.
And LED4a which is a light emitting element connected to Y and this LED4a
There is provided a photocoupler 4 including a phototransistor 4b which is a light receiving element which is turned on by lighting.

In the above configuration, the control unit 11 in the normal gas meter 1
, The output I of the L (low) level, the output II to H (high) level, and the bias resistor R ₁ of the transistors T ₁
By supplying a current to the bias resistors R ₃ and R ₄ of R ₂ and the transistor T ₄ , and biasing both transistors T ₁ and T ₄ to the ON state, the state of the gas leak alarm 2, that is, the inside of the gas leak alarm 2 Phototransistor 3b of Photocoupler 3
Switch to the mode that checks if is on or off.

In this check mode, the transistor T ₁
Since T and T ₄ are in the ON state, a current can be turned on or off through the resistor R ₅ according to ON / OFF of the phototransistor 3b of the photocoupler 3.

Therefore, when the gas leak alarm 2 detects a gas leak and a current is flowing, the potential at the point A in the figure becomes L level, and the gas leak alarm 2 does not detect a gas leak and the current flows. If not, the potential at the point A becomes H level, and the control unit 1 monitors this to detect abnormality and normality of gas leak detection on the gas meter 1 side, and a gas cutoff valve (not shown) provided in the gas supply path. Can be controlled, such as closing.

In addition to the above-mentioned gas leak check, the control unit 11 also checks the flow rate abnormality of the gas supply path and the signal from the seismic detector, etc. To do.

When the control unit 11 detects an abnormal situation and closes the gas shutoff valve as described above, or when the shutoff valve is scheduled to be closed, it is necessary to inform the householder (gas user) of this. In such a case, the control unit 11 sets the output I to the H level and the output II to the L level. Due to the L level of this output II, the transistor T ₂ and
T ₃ is turned on, the LED 4a of the photocoupler 4 is driven to light, and the phototransistor 4b is turned on. When the phototransistor 4b is turned on, a buzzer in the gas leak alarm 2 is sounded or a warning light emitting element is turned on, so that the user can be notified of the shutoff of the shutoff valve or the occurrence of the shutoff notice.

[Problems to be Solved by the Invention]

As described above, in the conventional system described above with reference to FIG. 10, when the control unit 11 detects an abnormal situation and closes the gas shutoff valve, or when the shutoff valve is scheduled to be closed, this is handled by a family member (gas user). The buzzer in the gas leak alarm 2 is sounded or the light emitting element for warning is turned on to notify. However, since there is only one type of alarm indicating the shutoff state of the shutoff valve depending on the cause of shutoff, depending on this alarm, whether the shutoff valve was shut off by the gas leak warning signal from the gas leak warning device 2 The gas user cannot know whether the operation was performed based on the abnormal flow rate in the supply path or the signal from the earthquake detector. For this reason, even if the alarm informs the gas user that the shutoff valve is shut off,
There has been a problem that the gas user cannot take the following measures promptly and appropriately.

Therefore, in view of the above-mentioned conventional problems, the present invention enables a gas user to clearly know the cause when there is an alarm indicating that the shutoff valve is shut off, and the subsequent actions to be taken. An object is to provide a gas alarm cutoff system that can be quickly and appropriately performed.

[Means for Solving the Problems]

In order to solve the above problems, a gas alarm cutoff system according to the present invention has a gas leak alarm and a gas meter that are mutually connected by two signal lines, and a cutoff valve provided in a gas supply path. When the gas meter side receives a gas leak warning signal from the gas leak warning device via the signal line, or receives an abnormal signal other than the gas leak warning signal from the gas leak warning device, the cutoff A valve is operated to shut off the gas supply path and a shutoff notification signal indicating the shutoff state of the shutoff valve is transmitted to the gas leak alarm via the signal line, and the gas leak alert is sent from the gas meter. In a gas alarm shutoff system for alerting that the shutoff valve is shutoff when a shutoff notice signal is received, the gas leak alarm device sends a shutoff notice signal from the gas meter. Judgment means for judging whether or not the gas leak warning signal has been transmitted to the gas meter before receiving, and reception of the cutoff notification signal when the judgment means judges that the gas leak warning signal is being transmitted. Alerts that the shutoff valve has been shut off due to a gas leak,
And a warning circuit for warning that the shut-off valve has been shut off by something other than a gas leak in response to receipt of the shut-off notification signal when the decision means has decided that the gas leak warning signal is not transmitted. Is characterized by.

[Action]

In the above configuration, when the gas meter side operates the shutoff valve to shut off the gas supply path and sends the shutoff notification signal indicating the shutoff state of the shutoff valve to the gas leak alarm device through the signal line, the gas leak alarm device operates as a gas meter. The shutoff valve is shut off by receiving a shutoff notification signal from the gas leak alarm device, but the determination means of the gas leak alarm device sends the gas leak alert signal to the gas meter before receiving the shutoff notification signal from the gas meter. Whether or not it is determined. Then, the alarm circuit of the gas leak alarm device, when it is determined by this determination means that the gas leak alarm signal is transmitted,
In response to the reception of the cut-off notification signal, the cut-off valve is warned that it has been cut off due to a gas leak, and when the judgment means determines that the gas leak warning signal is not transmitted, the cut-off notification signal is received. In response, it alerts that the shutoff valve has been shut off by something other than a gas leak.

Therefore, it is possible to easily know whether the gas supply passage is shut off by the shutoff valve by the gas leak detection by the gas leak alarm device or by a cause other than the gas leak detection by the alarm by the alarm circuit.

〔Example〕

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

FIG. 1 is a circuit block diagram showing an embodiment of a gas alarm cutoff system according to the present invention. In FIG. 1, the same parts as those of the conventional system described with reference to FIG. 10 are designated by the same reference numerals. .

In FIG. 1, the control unit 11 in the gas meter 1 is composed of a CPU that operates according to a predetermined program, and has outputs O _{1 to} O ₄ and inputs I _{1 to} In. The output O ₁ outputs the power supply control signal SG ₁ , the output O ₂ outputs the cutoff notification signal SG ₂ or the cutoff notice signal SG ₃ , the output O ₃ outputs the check signal SG ₄ , and the output O ₄ outputs the cutoff signal SG ₅ , respectively. Further, inputs I ₁ and I ₂ are first and second voltage discrimination signals SG ₆ and SG ₇ , input I ₃ is a cutoff state signal SG ₈ , and In is various detection signals from an earthquake detection sensor or a flow rate sensor (not shown). Input each signal.

The power supply control signal SG ₁ is a _first signal formed by a semiconductor switching element such as a switching transistor.
Is applied to the control input of the switch SW _1, to on-off control of the switch SW ₁ of the first. In addition, the cutoff notification signal S
The G ₂ or the cutoff warning signal SG ₃ is applied to the control inputs of the second and third switches SW ₂ and SW _{3 which} are composed of the same elements as the _first switch SW _1, and the second and third switches are respectively applied.
ON / OFF control of SW ₂ and SW ₃ . In addition, check signal
SG ₄ is applied to the control input of the second switch SW ₂ and controls the on / off of the _second switch SW ₂ .

The first and third switches SW ₁ and SW ₃ are connected in series between the + electrode of the battery power source and the ground, which is the reference potential point, and the interconnection point between them is one signal line X. Is connected to terminal a, which is connected to
A resistor R ₁ is connected in parallel with SW ₃ . The second switch SW ₂ has one end connected to the + electrode of the power source and the other end connected to the resistor R
₂ and the respective interconnection points are connected to the terminal b to which the other signal line Y is connected.

To the resistor R ₂ and R ₁ are first and second voltage judging circuit 12a and 12b for discriminating monitor voltage across these resistors are connected in parallel. First and second voltage judging circuit 12a and 12b to output the result of the voltage determining as the voltage determining signal SG ₆ and SG _7, respectively input these to the input I ₁ and I ₂ of the control unit 11 .

The shut-off signal SG ₅ is applied to the valve drive circuit 13 and the circuit 13
To drive the shutoff valve V. The shutoff valve V is provided in the gas supply passage K, and shuts off the gas supply passage K when turned on. The shutoff valve V is provided with an answer switch 14 which is turned on / off in association with the shutoff valve V, and the answer switch 14 generates a shutoff state signal SG ₈ when the answer switch 14 is turned on. By inputting the shutoff state signal SG ₈ to the input I ₃ of the control unit 11, the control unit 11 causes the gas supply passage K to shut off the shutoff valve V.
Know that you have been blocked by.

On the other hand, unlike the gas meter 1 that uses a battery as a power source, the gas leak alarm 2 uses a DC power source that rectifies and stabilizes a commercial AC power source, and operates according to a predetermined program.
The control unit 21 is configured by. This control unit 21 has outputs O ₁ and O ₂ and inputs I ₁ and I ₂ . The gas leak alarm device 2 also has a gas leak detection circuit 22 for detecting a gas leak and generating a gas leak detection signal SG ₉ , and the gas leak detection signal SG ₉ generated by the gas leak detection circuit circuit 22 controls the gas leak detection signal SG _9. Input to input I _{1 of} section 21. When the gas leak detection signal SG ₉ input to the input I ₁ thereof continues for 45 seconds, for example, the control unit 21
The output O ₁ , which is always at the L level, is output at the H
Pulsed gas leak alarm signal SG _{10 at} level O ₁
To occur. The gas leakage alarm signal SG ₁₀ blinks the LED3a of the photocoupler 3 in 5 second period, to intermittently turn on and off the phototransistor 3b of the photo coupler 3.

The phototransistor 3b of the photocoupler 3 is connected between terminals a'and b'to which the signal lines X and Y are respectively connected to the terminals a and b of the gas meter 2. Between the terminals a ′ and b ′, the photocoupler 4 is also connected.
A series circuit of the LDE 4a and the phototransistor 5b of the photocoupler 5 is connected in parallel to the phototransistor 3b and in the opposite direction. The phototransistor 4b of the photocoupler 4 has its emitter connected to ground and its collector connected to the control unit.
21 Input I ₂ is respectively connected to an input of the control unit 21 I ₂
Becomes L / H level according to ON / OFF of the phototransistor 4b.

The control unit 21 inputs I ₁ and output O ₂ by the state of I ₂
Then, various alarm data are output to the voice alarm circuit 23. As the alarm data output by the control unit 21, the gas leak detection signal SG ₉ from the gas leak detection circuit 22 is generated when the input I ₁ is input A ₁ , and the gas leak alarm signal SG ₁₀ is output. After disconnection notification signal SG ₂ from O ₁
There A ₂ shall be generated when the input to the input I _2, which is generated after the gas leak detection signal SG ₉ has disappeared by the blocking of the gas supply path after the output of the gas leak alarm signal SG ₁₀
A ₃ , which is generated when the cutoff notification signal SG ₂ is input to the input I ₂ without outputting the gas leak alarm signal SG ₁₀ , A ₄ ,
There is A ₅ that is generated when the cutoff warning signal SG ₃ is input to input ₂ .

The voice alarm circuit 23 is, as shown in FIG. 2, specifically, a voice data memory 23 in which voice data is stored.
a, the audio data read from the audio data memory 23a
D / A conversion circuit 23b that performs D / A conversion to form synthesized speech, and D / A
The audio amplification circuit 23c that amplifies the audio formed by the conversion circuit 23b and the speaker 23d that emits the audio amplified by the audio amplification circuit 23c. The voice data stored in the voice data memory 23a is the alarm data that is accessed by the alarm data A ₁ from the control unit 21 such as "pippipippipip, gas leaking?"
Accessed by A ₂ & A ₃
Gas is leaking, gas has been turned off ", alarm data A _{4 has} been accessed" pippy beep, gas has been stopped ", alarm data A ₅ has been" pippy beep, gas has not been used for a long time " Or "".

Although not shown, the voice alarm circuit 23 is provided with an indicator that lights up in green when power is supplied and an indicator that lights up in red when the gas leak detection signal SG ₉ is input. Has been.

The photodiode 5a of the photocoupler 5 is connected between the power source of the gas leak alarm 2 and the ground, and is connected to the gas leak alarm 2
Since it is constantly lit while the power is being supplied to
The phototransistor 5b of the photocoupler 5 is always in the ON state.

The operation of the system having the above configuration will be described below with reference to the waveform diagrams showing the signal waveforms of the respective portions shown in FIGS.

Gas meter control unit 11 of 1 outputs the power supply control signal SG ₁ becomes constant period, for example 5 milliseconds H level for example one second, as shown in the normal FIG. 3 to its output O _1, in the H level period Turn on the _first switch SW ₁ . At this time if the ON phototransistor 3b of the photocoupler 3, for example, large current i ₁ is the signal line X of 300 .mu.A, the phototransistor 3b, it flows through the signal lines Y and the resistor R _2, the resistance R ₂ of the voltage across V _R2 Is a relatively large value. On the other hand, if the phototransistor 3b of the photocoupler 3 is not turned on, only a small current i ₁ of, for example, about 10 μA flows, and the voltage V _R2 across the resistor R ₂ becomes an extremely small value. The voltage V _R2 across the resistor R ₂ is the first voltage determination circuit 12a.
And is compared with a predetermined voltage value set in advance, and the magnitude relationship of the predetermined voltage with respect to the voltage value is determined. The determination result in this voltage determination circuit 12a is
The voltage discrimination signal SG ₆ is input to the input I ₁ of the control unit 11.

The control unit 11 of the gas meter 1 also outputs H ₃ at its output O ₃ at a constant cycle of, for example, 60 seconds for 5 milliseconds, as shown in FIG.
A level check signal SG ₄ is output, and the second switch SW ₂ is turned on during the H level period. At this time, if the phototransistor 5b of the photocoupler 5 is turned on, a large current i _{2 of} 300 μA, for example, is applied to the signal line Y, the phototransistor 5b, the diode 4a, the signal line X and the resistor R _1.
Flow, the voltage across V _R1 of the resistor R ₁ is a relatively large value throughout. On the other hand, if the phototransistor 5b of the photocoupler 5 is not turned on, only a small current i ₂ of, for example, 10 μA or less flows, and the voltage V _R1 across the resistor R ₁ becomes an extremely small value. The voltage V _R1 across the resistor R ₂ is supplied to the second voltage determination circuit 12b, and is compared with a predetermined voltage value set here, and the magnitude relationship with the predetermined voltage value is determined. In case the result of judgment in the voltage judging circuit 12b is input to the input I ₂ of the control unit 11 as a voltage determination signal SG _7.

Since the phototransistor 3b is off when the gas leak alarm 2 does not detect the gas leak, the resistance R is high when the power supply control signal SG ₁ is at the H level.
The voltage V _R2 between both ends of ₂ becomes a small value. Therefore, the first voltage determination circuit 12a monitors the voltage V _R2 across the resistor R ₂ when the power supply control signal SG ₁ is at H level, and outputs the voltage V _R2 when the voltage V _R2 is below a predetermined value. Voltage discrimination signal SG
Set ₆ to L level. Therefore, when the input I ₁ is at L level, the control unit 11 sends an alarm signal SG ₁₀ from the gas leak alarm device 2 side.
It is determined that is not output.

On the other hand, the gas leak detection circuit 22 of the gas leak alarm 2
When the gas leak is detected and the gas leak detection signal SG ₉ is generated, the control unit 21 outputs a pulse-shaped gas leak warning signal SG with a duty ratio of 50%, for example, a cycle of 10 seconds, as shown in FIG. ₁₀ is generated to turn on / off the phototransistor 3b of the photocoupler 3. As a result, there always occurs a period in which the ON period of the first switch SW ₁ which is turned on at a cycle of 1 second by the power supply control signal SG ₁ of FIG. 3 and the ON period of the phototransistor 3b overlap each other, and a large current flows during that period.
i ₁ flows, the voltage across _R2 increases the resistance R _2, a first voltage determining circuit 12a which monitors the voltage across _R2 will be a voltage determining signal SG ₆ of its output to the H level. Then, the control unit 11 judges that the alarm signal SG ₁₀ is being output from the gas leak alarm device 2 side when the input I ₁ thereof becomes the H level twice.

Further, as described above, when the gas leak detection circuit 22 generates the gas leak detection signal SG ₉ by the gas leak detection, the control unit 21 generates the warning data A ₁ in response to this and supplies it to the voice warning circuit 23. Then, the specified voice data is accessed from the voice data memory 23a in it, and the accessed voice data is converted and amplified, and a voice alarm is generated from the speaker 23d, "Isn't gas leaking?" Let

As described above, when the voltage discrimination signal SG ₆ input from the first voltage discrimination circuit 12a to the control unit 11 becomes the H level twice and then becomes the L level, the control unit 11 supplies the power of its output O ₁ . the control signal SG ₁ with kept in an H level, outputs a blocking signal SG ₅ in the cutoff valve driving circuit 13 actuates the shut-off valve V in the cutoff valve driving circuit 13 to cut off the gas supply path K from the output O ₄ Let By the operation of this shutoff valve V, the answer switch
14 is turned on and the cutoff state signal SG ₈ becomes H level.

Since the power supply control signal SG ₁ is held at the H level as described above, the voltage V _R2 across the resistor R ₂ has a predetermined value in synchronization with the gas leak alarm signal SG ₁₀ from the gas leak alarm 2. It changes to the above and below, and accordingly, the voltage discrimination circuit 12
a outputs a voltage discrimination signal SG ₆ which becomes H / L level in synchronization with the gas leak alarm signal SG ₁₀ , and inputs this to the input I _{2 of the} control unit 11.
To enter. The control unit 11 controls the cutoff state signal SG as described above.
_{When 8} is at H level, the voltage discrimination signal SG ₆ of the input I ₂ is monitored, and when the voltage discrimination signal SG ₆ becomes L level, the power supply control signal SG ₁ is changed from H level to L level, and outputs a shutoff notification signal SG ₂ as shown in FIG. 6 in the H level during the output O ₂ in the L level for example, twice at an interval of 0.3 seconds for example, 0.1 seconds from the output O _2. The power supply control signal SG ₁ is held at the L level for 5 seconds and then brought back to the H level, and this state is held until the same as the above occurs.

As described above, when the cutoff notification signal SG ₂ becomes H level, the second and third switches SW ₂ and SW ₃ are simultaneously turned on. When the switches SW ₂ and SW ₃ are turned on at the same time, when the phototransistor 5b is turned on, the power is supplied from the power source through the switch SW ₂ , the signal line Y, the phototransistor 5b, the light emitting diode 4a, the signal line X, and the switch SW _3. A current flows to the ground, and the light emitting diode 4a is turned on.

The phototransistors 4b by lighting the light emitting diodes 4a of the photo-coupler 4 is turned on, the signal blocking notification signal SG ₂ opposite in phase to the input I ₂ of the gas leak alarm second control unit 21 is inputted. In response to this, the control unit 21 causes the gas leak detection circuit to
While the gas leak detection signal SG ₉ from 22 is input, its output O ₂ generates alarm data A ₂ , which is output by the audio alarm circuit 23.
To access predetermined audio data from the audio data memory 23a in the audio data memory 23a, convert the accessed audio data, amplify the converted audio data, and output from the speaker 23d.
A sound alarm "Gas leaked, gas stopped" is generated, which alerts that the shutoff valve V has been shut off in response to the gas leak alarm.

As described above, since the shutoff valve V is shut off on the gas meter 1 side in response to the generation of the gas leak detection signal SG ₉ , the gas leak is reduced to a level that cannot be detected by natural ventilation, and the gas leak detection signal SG ₉ is It goes to L level at an appropriate time. With such gas leak detection signal SG ₉ becomes L level, the control unit 21 to not turn on the light-emitting diode 3a of the photocoupler 3 to the gas leakage alarm signal SG ₁₀ to L level.

Further, when the gas leak detection signal SG ₉ becomes L level, the control unit 21 outputs the alarm data A ₃ to the output O ₂ in response to this and supplies it to the audio alarm circuit 23 to output the audio data therein. The predetermined audio data is accessed from the memory 23a, the accessed audio data is converted and amplified, and then the speaker 23d is accessed.
Generates a voice alarm "Pippipippip, gas leak, gas stopped", thereby warning that the shutoff valve V is continuously shut off in response to the gas leak alert.

When the gas user notices this warning and opens the shut-off valve V after performing a predetermined measure, the answer switch 14 is turned off and the shut-off state signal SG ₈ becomes L level. In response to this, the control unit 11 switches the cutoff notification signal SG _{2 so as} to always hold it at the L level, and switches the power supply control signal SG ₁ again to a signal having a predetermined cycle as shown in FIG.
The LED 4a of the photocoupler 4 is turned off when the cutoff notification signal SG ₂ is constantly at L level, and the input I of the control unit 21
₂ is always held at the H level, and the above-mentioned operation of the voice alarm circuit 23 is stopped.

Next, the control unit 11 of the gas meter 1 outputs the gas leak alarm signal SG ₁₀
Other than the above, for example, an operation in the case of giving a so-called advance notice of notifying the gas leak alarm device 2 to shut off the shutoff valve V according to an abnormal signal based on detection of an abnormal flow rate will be described.

When giving a notice of shutoff of the shutoff valve V, the control unit 11 of the gas meter 1 outputs the H level for 0.1 second at a cycle of, for example, 5 seconds, as shown in FIG. 7, while the power supply control signal SG ₁ is at the L level. Outputs the cutoff warning signal SG ₃ which continues for about 5 minutes O ₂
And output from, turns on the second and third switches SW2 and SW _3. As a result, the light emitting diode of the photocoupler 4
4a lights up and this is the input of the control unit 21 of the gas leak alarm 2.
It is input to I ₂ as a signal with a phase opposite to the shutdown warning signal SG ₃ .
In response to this, the control unit 21 generates the alarm data A ₅ at its output O ₂ , supplies it to the audio alarm circuit 23, accesses the predetermined audio data from the audio data memory 23a therein, and accesses this. Speaker 23 after converting and amplifying audio data
From d, generate a voice alarm "Pippipippiping, do you use gas for a long time?"

After the lapse of 5 minutes, the control unit 11 outputs a shutoff signal to the output O ₄ to shut off the shutoff valve V, and when the shutoff state signal SG ₈ generated in response thereto is input, the power supply control signal SG ₁ Outputs the cutoff notification signal SG ₂ of FIG. 6 by utilizing the L level period O ₂
Output from. As a result, the control unit 21 of the gas leak alarm 2 generates alarm data A ₄ at the output O ₂ , supplies it to the audio alarm circuit 23, and outputs predetermined audio data from the audio data memory 23a therein for 5 seconds. It accesses each time, and after amplifying the accessed voice data, it amplifies it and repeatedly outputs the voice alarm "Pippipippipp, gas stopped" from the speaker 23d, which shuts off the shut-off valve V for any reason other than gas leak. Warn that you are in a state.

If the gas leak warning signal SG ₁₀ is input from the gas leak warning device 2 within the period of 5 minutes during which the cutoff warning signal SG ₃ is output, while the power supply control signal SG ₁ is at the H level, Then, the voltage discriminating circuit 12a discriminates that the voltage V _R2 across the resistor R ₂ has become L level, and the voltage discriminating signal SG ₆ is outputted to the output thereof. Therefore, after that, the same operation as described above is performed, the shutoff valve V is immediately shut off, and an accident due to gas leakage can be prevented.

As described above, the control unit 11 of the gas meter 1 outputs the check signal SG ₄ which becomes the H level for 5 milliseconds for a constant period of, for example, 60 seconds to the output O ₃ , as shown in FIG. The timing of raising the H level of the check signal SG ₄ is set so that the power supply control signal SG _{1 which} is at the H level in the 1 second cycle of FIG. 3 is in the L level. The second switch SW _{2 which} is turned on during the H level period of the check signal SG ₄ is turned on to supply power from the power source through the signal line Y, the phototransistor 5b as the switch means, the light emitting diode 4a, the signal line X and the resistor R _1. It functions as a current supply means for forming a current path to the ground and supplying the current i ₂ to the current path.

When the current i ₂ is supplied to the above current path and the power supply on the gas leak alarm 2 side is normally supplied, the light emitting diode 5a of the photocoupler 5 is in a lighting state and the phototransistor 5b is turned on. ing. Therefore, at this time, the signal line X,
If Y is not disconnected, the signal line Y, the phototransistor 5b, diodes 4a, a large current i ₂ through the signal line X and the resistor R ₁ (where the light emitting diode 4a is not lit level) flows across the resistor R ₁ The voltage V _R1 becomes a relatively large value.

On the other hand, the gas leak alarm 2 is not normally supplied with power, the light emitting diode 5a of the photocoupler 5 is in a non-lighting state, the phototransistor 5b is off, or the signal lines X, Y Is disconnected, the signal line Y, the phototransistor 5b, the diode 4a, the signal line X and the resistor
Since the current i ₂ flowing through R ₁ becomes extremely small or no current flows at all, the voltage V _R1 across the resistor R ₁
Is a very small value or zero.

Therefore, the voltage V _R1 across the resistor R ₁ is the second voltage determination circuit 12b.
In step S1, the voltage is compared with a predetermined voltage value set in advance. The second voltage determination circuit 12b holds the output at the L level when the voltage V _R1 across the resistor R ₁ is larger than the second voltage determination predetermined voltage value, but when the voltage is smaller than the predetermined voltage value, the output is set at the L level. Start up. This second voltage determination circuit 12b
Is output to the input I ₂ of the control unit 11 as the voltage determination signal SG _{7 and} monitored by the control unit 11. Based on the voltage discrimination signal SG ₇ , the control unit 11 judges whether the power supply on the gas leak alarm 2 side is normally supplied or whether the signal line is broken, and the voltage discrimination signal SG ₇ is output twice. When it rises to the H level, it is determined that the power supply on the gas leak alarm 2 side is not normally supplied or the signal line is broken. Based on this determination, the control unit 11 outputs the shutoff signal SG ₅ to the output O ₄ and shuts off the shutoff valve V after a certain period of time has elapsed. In response to the shutoff of the shutoff valve V, the shutoff state signal SG ₈ is input to the input I ₃ , but the control unit 11 outputs the shutoff notification signal SG ₂ to the output O ₂ in the same manner as described above to output the gas leak alarm. The alarm circuit 23 of the device 2 cannot give an alarm.

In addition, in the situation where the power is not supplied to the gas leak alarm device 2,
AC due to failure of the power circuit of the gas leak alarm 2 or self-damage
It is possible that the outlet is pulled out or there is a power outage.

Next, the control unit 21 of the gas leak alarm device 2 generates alarm data based on the cutoff notification signal SG ₂ and the cutoff notice signal SG ₃ from the gas meter 1 and the gas leak detection signal SG ₉ from the gas leak detection circuit 22. Details of the operation will be described below with reference to the flowchart of FIG.

The CPU that constitutes the control unit 21 starts its operation when the power is turned on, and in step S1, the gas leak detection signal SG is input to the input I _1.
9 it is determined whether or not input, the process proceeds to step S2 when this determination is NO, wherein the cutoff notice signal to the input I ₂
Determine whether SG ₂ is input. This step S
When the determination in 2 is also NO, the process returns to step S1 and the above steps S1 and S2 are repeatedly executed. The judgment in step S1 is YE
When S, that is, the gas leak detection signal SG ₉ is input to I ₁ , the process proceeds to step S3, where it is determined whether or not the cutoff notification signal SG ₂ is input to the input I ₂ . This step S
If the judgment in 3 is NO, the flow proceeds to step S4, where the output O ₂
The alarm data A ₁ is output to and the voice alarm circuit 23 is caused to generate a voice alarm "Pippipippippippei gas leaking?" After performing step S4, return to step S1,
The gas leak detection signal SG ₉ disappears and the determination in step S1 is NO.
Or the cutoff notification signal SG ₂ is input and step S
Steps S1, S3 and S4 are repeated until the determination of 3 becomes YES.

When the judgment in step S3 is YES, the process proceeds to step S5, where the alarm data A ₂ is output to the output O ₂ and the voice alarm circuit 23 outputs "Pippipippipippi, gas leak, gas stopped" Raise an alarm. Then step
The process proceeds to S6, where the 15-second timer built in the control unit 21 is set, and then the process proceeds to step S7. In step S7,
It is determined whether or not the cutoff notification signal SG ₂ is input during the operation of the 15-second timer set in step S6. If the cutoff notification signal SG ₂ is input, the process proceeds to step S8, and the gas leak alarm signal SG ₉
It is determined whether or not is input. When the determination in step S8 is YES, the process returns to step S5, and the alarm data A ₂ is output again to generate the voice alarm. The above steps S5 to S8 are repeatedly executed until the determination in step S7 or S8 becomes NO, and the voice alarm is generated at a predetermined time interval.

When the shutoff valve is restored while the voice alarm is issued and the shutoff notification signal SG ₂ disappears, the determination in step S7 becomes NO, and the process returns to step S1. Further, when the gas leakage is no longer detected by the gas leakage detection circuit 22 due to the gas interruption and the determination in step S8 is NO, the process proceeds to step S9. In step S9, and outputs the alarm data A ₃ to the output O _2,
The voice alarm circuit 23 says, "Pippipippipippi, gas leak,
I turned off the gas. " After that, the process proceeds to step S10, the 15-second timer built in the control unit 21 is set here, and then the process proceeds to step S11. Step S
In 11, it is determined whether or not the cutoff notification signal SG ₂ is input during the operation of the 15-second timer set in step S11, and if it is input, the process returns to step S9,
Steps S9 to S11 are repeatedly executed until the determination in S11 becomes NO, and the voice alarm is generated at a predetermined time interval. When the shutoff valve is restored while the voice alarm is issued and the shutoff notification signal SG ₂ disappears, the determination in step S11 becomes NO and the process returns to step S1.

When there is no gas leak detection signal SG _{9 and} the determination in step S1 is NO, it is determined whether the cutoff notification signal SG ₂ is input. When the determination in step S2 is YES, the process proceeds to step S12, where the output O _The alarm data A ₄ is output to 2 and the voice alarm circuit 23 is caused to generate a voice alarm "pippipippipippi, gas stopped".

As described above, when the shutoff valve shuts off the gas supply path in response to the input of the gas leak detection signal SG ₉ ,
When the shutoff valve is shut off by a signal other than SG ₉ ,
The voice alarm can be changed to "Pippipippip, gas leak, gas stopped," or "pippy beep, gas stopped."
A gas user who hears this audible alarm can easily know why the shut-off valve is shut off, and can take appropriate action.

As described above, the gas meter 1 is operated by the operation described in the embodiment.
The timing of signals transmitted and received between the alarm device 2 and the alarm device 2 and the operating state of the voice alarm circuit 2 in the alarm device 2 are summarized in the timing chart of FIG.

〔effect〕

As described above, according to the present invention, whether the gas supply path is shut off by the shutoff valve by the alarm by the alarm circuit is performed by the gas leak detection by the gas leak alarm or by a cause other than the gas leak detection. Therefore, when there is an alarm indicating that the shut-off valve is shut off, the gas user can clearly know the cause, and the subsequent action can be taken promptly and appropriately. The effect that it can be obtained is obtained.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of a gas alarm cutoff system according to the present invention, FIG. 2 is a block diagram showing a specific configuration of a part of FIG. 1, and FIG. 3 is a diagram showing a power supply control signal. Waveform diagram showing waveforms, FIG. 4 is a waveform diagram showing waveforms of check signals, FIG. 5 is a waveform diagram showing waveforms of gas leak alarm signals, FIG. 6 is a waveform diagram showing waveforms of cutoff notification signals, and FIG. Fig. 8 is a waveform diagram showing the waveform of the shutoff warning signal, Fig. 8 is a flowchart diagram showing the work performed by the control unit of the gas leak alarm in Fig. 1, and Fig. 9 summarizes the operation of the system of Fig. 1. FIG. 10 is a timing chart diagram shown by FIG. 10, and FIG. 10 is a diagram showing a configuration example of a conventional system. 1 ... Gas meter, 2 ... Gas leak alarm, 21 ... Control unit (determination means), 23 ... Voice alarm circuit (alarm circuit), X,
Y: signal line, K: gas supply path, V: shutoff valve, SG ₂ ...
… Shutdown notification signal, SG ₉ …… Gas leak detection signal, SG ₁₀ ……
Gas leak alarm signal.

Claims (1)

[Claims] 1. A gas leak alarm and a gas meter, which are connected to each other by two signal lines, and a shutoff valve provided in a gas supply path, wherein the gas meter side is connected to the gas via the signal line. When a gas leak warning signal from the leak warning device is received, or when an abnormal signal other than the gas leak warning signal from the gas leak warning device is received, the shutoff valve is operated to shut off the gas supply path and When the cutoff notification signal indicating the cutoff state of the cutoff valve is transmitted to the gas leak alarm device through the signal line, and the gas leak alarm device receives the cutoff notification signal from the gas meter, the cutoff valve shuts off. In the gas alarm cutoff system for warning that the gas leak alarm signal has been transmitted to the gas meter before the cutoff notification signal from the gas meter is received. And a determination means for determining whether or not the gas leakage warning signal is transmitted by the determination means, the shutoff valve being shut off by gas leakage in response to the reception of the shutoff notification signal. An alarm circuit for issuing an alarm and, when the determination means determines that the gas leak alarm signal is not transmitted, alerts that the shut-off valve is shut off by something other than gas leak in response to the receipt of the shut-off notification signal; A gas alarm cutoff system, comprising: