JP2003028966A - Gas meter and earthquake determining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas meter for breaking gas supply reliably only, in the case of an earthquake by discriminating the earthquake from shock, and to provide an earthquake determining method for discriminating earthquakes from shocks. SOLUTION: The gas meter comprises a multi-stage seismoscope 1 having a first seismoscope 10 for detecting vibration at a specific sensitivity for outputting as a pulse signal; a second seismoscope 11 for detecting vibration with lower sensitivity than a specific one for outputting as a pulse signal; a detection circuit 2 for detecting whether a pulse signal from the first seismoscope includes pulses exceeding specific width at least by a specific number within specific time; a time measurement circuit 3 for detecting whether or not a time difference, until a pulse signal is outputted from the second seismoscope after a pulse signal is outputted from the first seismoscope is equal to or more than specific time; and a controller 7 for breaking gas supply, when it is detected that pulses exceeding specific width are included at least by a specific number within specific time using a detection circuit, and the time difference is equal to or more than a specific time in a time measurement circuit.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gas meter,
In particular, the present invention relates to a technique for detecting a vibration caused by an earthquake to cut off a gas supply or determining an earthquake.

[0002]

2. Description of the Related Art Conventionally, a gas meter provided with a vibration sensor has been known. In this gas meter, the seismoscope detects the vibration and outputs it as a pulse signal, and the control unit judges that an earthquake has occurred based on the pulse signal and shuts off the gas supply. However, this gas meter has a drawback in that even when a vibration other than the vibration due to the earthquake is detected, it is erroneously determined that the earthquake has occurred.

Therefore, in order to eliminate this drawback, an improved gas meter has been developed so as to observe the waveform of the pulse signal output from the seismic sensor and detect only the earthquake based on the observation result. . For example, a gas meter that detects only earthquakes by providing a detection circuit that detects the characteristics of seismic waves in which multiple long pulses exist in a certain period of time, and the strength of shaking is detected using a seismoscope with different shaking detection sensitivity. Has developed a gas meter that detects only earthquakes.

[0004]

However, the gas meter may sway due to a strong impact to cause resonance with the pipe fixing the gas meter. In this case, a large and long vibration is generated in the gas meter, and the pulse signal output from the seismic sensor has the same waveform as the pulse signal due to the earthquake. As a result, there is a problem that it is erroneously determined that an earthquake has occurred despite the impact.

An object of the present invention is to solve such a problem, and by distinguishing an earthquake from an impact, a gas meter and an earthquake which can reliably cut off the gas supply only at the time of the earthquake. An object of the present invention is to provide an earthquake determination method capable of distinguishing from an impact.

[0006]

In order to achieve the above object, the gas meter of the present invention includes a seismoscope which detects vibration with different sensitivities and outputs a plurality of pulse signals corresponding to the different sensitivities. A detection circuit for detecting whether or not each pulse signal from the seismic sensor includes a predetermined number or more of pulses having a predetermined width or more within a first predetermined time, and a time difference between the start of pulse output of each pulse signal from the seismic sensor. A time measuring circuit for measuring
When the detection circuit detects that a predetermined number or more of pulses having a predetermined width or more are included within the first predetermined time, the vibration is a vibration caused by an earthquake or a vibration caused by an impact based on the time difference measured by the time measurement circuit. And a controller for determining whether or not. Further, in the controller, the detection circuit detects that a predetermined number or more of pulses having a predetermined width or more are included within a first predetermined time, and the time difference measured by the time measurement circuit is a second predetermined time or more. In this case, it is characterized in that the vibration is determined to be vibration caused by an earthquake and the gas supply is cut off.

According to this gas meter, one of the characteristics of the earthquake is
Whether or not the vibration is based on an earthquake, as in the conventional case, is whether or not each pulse signal from the seismic sensor includes a predetermined number or more of pulses having a predetermined width or more within the first predetermined time.
It cannot be distinguished whether it is based on shock.
However, in the gas meter of the present invention, it is further determined whether the vibration is a vibration caused by an earthquake or a vibration caused by a shock, based on the time difference when the pulse output of the pulse signal is started from the seismic sensor.
In addition, it is determined that the earthquake occurs only when the time difference is equal to or greater than the second predetermined time. Therefore, a situation in which a gas other than an earthquake is erroneously determined to be an earthquake and the gas is shut off does not occur, and the gas supply can be reliably shut off only during the earthquake.

Further, the earthquake determination method of the present invention includes the first step of detecting vibrations with different sensitivities and outputting a plurality of pulse signals corresponding to the different sensitivities, and each pulse signal within a first predetermined time. A second step of detecting whether or not a predetermined number or more of pulses having a predetermined width or more are included, and a third step of measuring a time difference at the start of pulse output of each of the pulse signals,
When it is detected that a predetermined number or more of pulses having a predetermined width or more are included within the first predetermined time, it is determined whether the vibration is a vibration caused by an earthquake or a vibration caused by an impact based on the time difference measured in the third step. And a fourth step of Also, the fourth step includes the second step.
When it is detected in the step that a predetermined number or more of pulses having a predetermined width or more are included in the first predetermined time, and the time difference measured in the third step is the second predetermined time or more, the vibration is caused by an earthquake. It is characterized in that the supply of gas is cut off when it is determined that

According to this earthquake determination method, the same action and effect as those of the gas meter can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a gas meter and an earthquake determination method capable of distinguishing an earthquake from an impact according to an embodiment of the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
It is a block diagram which shows the structure of the gas meter of embodiment. This gas meter is a multi-stage seismic device 1 as a seismic device,
Detection circuit 2, time measurement circuit 3, shutoff valve 4, communication interface (communication I / F) 5, display unit 6 and controller 7
It consists of

As shown conceptually in FIG. 2, the multistage vibration-sensing device 1 has a structure in which a first vibration-sensing device 10 and a second vibration-sensing device 11 are integrally formed. The first seismoscope 10 is a switch, one of which is connected to the common terminal COM and the other of which is connected to the output terminal O1, and can be considered as a switch which is turned on / off by vibration of a predetermined magnitude. That is, the first seismoscope 10 functions as a sensor that detects vibration with a predetermined shake detection sensitivity and outputs the detection result as a pulse signal SIG1 from the output terminal O1.

One of the second seismic sensors 11 has a common terminal COM.
And a switch connected to the output terminal O2 on the other side, and can be considered as a switch that is turned on / off by vibration larger than the predetermined magnitude. That is,
The second seismic transducer 11 functions as a sensor that detects vibration with a detection sensitivity that is lower than the above-described sensitivity and that outputs the detection result as a pulse signal SIG2 from the output terminal O2.

Therefore, the multistage seismoscope 1 outputs the pulse signal from the first seismoscope 10 when the vibration is small, and outputs the pulse signal from the second seismoscope 11 when the vibration becomes large. Has become.

FIG. 3 shows an output signal of the multi-stage seismoscope 1 when there is a shock such as hitting a ball with a gas meter. That is, when the shock waveform as shown in FIG. 3A is applied to the multi-stage seismic transducer 1, the first seismic transducer 10
As shown in FIG. 3B, a pulse signal SIG1 composed of a large number of pulses having a relatively short width obtained by slicing a shock wave at a low threshold level is output. Second seismic sensor 11
Outputs a pulse signal SIG2 composed of a small number of pulses obtained by slicing a shock wave at a high threshold level, as shown in FIG. 3 (c).

FIG. 4 shows an output signal of the multi-stage seismoscope 1 when an earthquake occurs. That is, when the seismic waveform as shown in FIG. 4 (a) is applied to the multi-stage seismoscope 1, the first seismoscope 10 produces a shock wave at a low threshold level as shown in FIG. 4 (b). A pulse signal SIG1 including a sliced pulse having a relatively long width is output. Second seismic sensor 11
Outputs a pulse signal SIG2 composed of similar pulses obtained by slicing a shock wave at a high threshold level, as shown in FIG. 4 (c).

The pulse signal SIG1 output from the first seismic sensor 10 and the pulse signal SIG2 output from the second seismic sensor 11 of the multi-stage seismic sensor 1 are sent to the detection circuit 2 and the time measuring circuit 3.

The detection circuit 2 detects whether or not the waveform of the pulse signal SIG1 from the first seismic sensor 10 indicates the characteristics of an earthquake. Specifically, it is detected whether or not the pulse signal SIG1 includes a predetermined number (for example, 5) of pulses having a predetermined width (for example, 100 milliseconds) or more within a predetermined time (for example, 10 seconds). The detection result of the detection circuit 2 is the controller 7
Sent to. Incidentally, conventionally, it was determined only by the output of the detection circuit 2 whether an earthquake occurred. The detection circuit 2 also detects the pulse signal SIG2 from the second seismic sensor 11 in the same manner.

As shown in FIG. 5, the time measuring circuit 3 measures the time difference from the rising of the pulse signal SIG1 from the first seismic sensor 10 to the rising of the pulse signal SIG2 from the second seismic sensor 11, It is detected whether the measured time difference is a predetermined time or more, and the detection result is sent to the controller 7.

The shutoff valve 4 shuts off a gas supply passage (not shown) in response to a control signal from the controller 7. The communication interface 5 controls communication between the controller 7 and an external device. The display unit 6 responds to the control signal from the controller 7 to display the measured value and the alarm.

The controller 7 is composed of, for example, a microcomputer, and has a CPU, a memory, a timer,
It has an input / output interface (neither shown). The controller 7, which will be described in detail later, controls the shutoff valve 4 based on the signal from the detection circuit 2 and the signal from the time measurement circuit 3, and also measures the amount of gas used and displays it on the display unit 6. Further, control such as displaying an alarm is performed.

Next, the operation of the gas meter according to the first embodiment of the present invention will be described. That is, the earthquake determination method according to the first embodiment will be described.

FIG. 6 shows an output waveform of the multi-stage seismoscope 1 in case of an earthquake. When an earthquake occurs, the first seismoscope 10 senses the vibration and detects a pulse signal SIG1 as shown in FIG.
Is output. As a result, the time measuring circuit 3 starts measuring the time difference. Next, when the vibration becomes large, the second seismoscope 11 causes the pulse signal SIG2 as shown in FIG.
Is output. As a result, the time measuring circuit 3 stops measuring the time difference and the time difference is fixed. In the case of an earthquake, this time difference becomes equal to or greater than the predetermined value, so the time measuring circuit 3 transmits a signal indicating the detection result to the controller 7. The time measuring circuit 3 holds this time difference until the vibration ends.

FIG. 7 shows an output waveform of the multi-stage seismoscope 1 in the case of a shock other than an earthquake. When a shock occurs, the first seismic sensor 1
0 senses vibration and outputs a pulse signal SIG1 as shown in FIG. 7 (a). As a result, the time measuring circuit 3
Starts the time difference measurement. Next, when the vibration becomes large, the second seismic transducer 11 outputs the pulse signal SIG2 as shown in FIG. 7 (b). As a result, the time measuring circuit 3
Stops the time difference measurement and the time difference is fixed. In the case of an impact other than an earthquake, this time difference does not exceed the predetermined value, so the time measuring circuit 3 does not send a signal indicating the detection result to the controller 7. The time measuring circuit 3 holds this time difference until the vibration ends.

When the vibration is subdued in both earthquakes and shocks, the output of the second seismic sensor 11 is stopped first, and then the output of the first seismic sensor 10 is stopped. When vibration occurs many times due to an earthquake, the first and second seismic sensors 10 and 11 continuously output pulse signals.

Next, when five waveforms having a long pulse width that characterize an earthquake occur within a predetermined time, the detection circuit 2 tentatively determines that an earthquake has occurred, and sends a signal indicating the determination result to the controller 7. If not, the signal indicating the determination result is not sent.

The controller 7, which has received the signal indicating the detection result from the detection circuit 2 and the signal indicating the judgment result from the time measuring circuit 3, determines the presence or absence of an earthquake according to the flowchart shown in FIG. 8 and controls the shutoff valve 4. To do. That is,
The controller 7 first checks whether there is an output signal from the detection circuit 2 (step S10). Here, there is no output signal, that is, the pulse signal SIG1 from the first seismic transducer 10.
When it is determined that the waveform of does not indicate the characteristics of the earthquake, the process ends.

On the other hand, if it is judged that there is an output signal, that is, the waveform of the pulse signal SIG1 from the first seismic detector 10 indicates the characteristics of the earthquake, then the presence or absence of the output signal from the time measuring circuit 3 is determined. Is checked (step S11). If it is determined that there is no output signal, that is, the time difference is not equal to or longer than the predetermined time, it is recognized that the vibration is due to impact (step S12), and the process ends.

On the other hand, when there is an output signal from the time measuring circuit 3, that is, when it is determined that the time difference is more than a predetermined time, it is recognized that the vibration is caused by an earthquake (step S13) and the control signal is cut off. The gas supply is cut off by sending it to the valve 4 (step S14), and the process is terminated.

As described above, according to the gas meter of the first embodiment, when the multistage seismoscope 1 senses a weak vibration,
The pulse signal SIG1 is output from the first seismic transducer 10, and when the vibration subsequently becomes strong, the pulse signal S is output from the second seismic transducer 11.
IG2 is output. At this time, the time measuring circuit 3 measures the time from the start of the first pulse of the pulse signal SIG1 to the start of the first pulse of the pulse signal SIG2.
In the case of a shock with a large vibration, the time measured by the time measuring circuit 3 is very short, but in the case of an earthquake, it is generally long.
When the vibration continues and the detection circuit 2 detects a predetermined number or more of pulses having a predetermined width or more, which is a feature of the seismic wave, in a predetermined time, the controller 7 tentatively determines that there is an earthquake. If the controller 7 temporarily determines that there is an earthquake, the time measuring circuit 3
If the time measured in is short, it can be judged as an impact, and if it is long, it can be judged as an earthquake. For this reason, there is no case where the gas supply is interrupted by mistakenly determining an earthquake and a shock.

In the conventional gas meter, the detection circuit 2 detects a predetermined number or more of pulses having a predetermined width or more, which is a characteristic of seismic waves, in a predetermined time even if the pulse signal is generated by an impact as shown in FIG. Therefore, the controller erroneously determines that it is an earthquake and controls the shutoff valve 4 to shut off the gas supply.

The controller 7 of the gas meter according to the first embodiment described above is modified so as to be realized by the logic circuit shown in FIG. 9 (hereinafter, referred to as a first modification of the first embodiment). You can also The logic circuit of the first modification of the first embodiment is a 2-input AND gate 2
0, an inverter 21, and a 2-input AND gate 22. The output signal from the detection circuit 2 is AND
It is sent to each first input terminal of the gates 20 and 22. The output signal from the time measuring circuit 3 is sent to the second input terminal of the AND gate 20 and the inverter 21, and the inverter 2
The output signal of 1 is sent to the second input terminal of the AND gate 22.

With the above structure, the AND gate 20 outputs an active signal when vibration due to impact occurs, and the AND gate 22 outputs an active signal when vibration due to an earthquake occurs. Therefore, by controlling the shutoff valve 4 by the output signal of the AND gate 22, the gas supply can be shut off only in the event of an earthquake, and the gas supply can be prevented from being shut off by the vibration due to the impact. According to the first modification of the first embodiment, the controller 7 can be configured with only a small number of logic elements and it is not necessary to use a microcomputer or the like, so that the gas meter can be made simple and inexpensive.

(Second Embodiment) The gas meter of the second embodiment has a longer pulse signal output from the multi-stage seismoscope in the case of vibration caused by an earthquake than in the case of vibration caused by impact. This was done paying attention to the fact that wavelength pulses are included. That is, even when the gas meter of the first embodiment determines that an impact has occurred, when the pulse signal output from the multi-stage seismoscope 1 has a long pulse of a predetermined length or more, it is determined to be an earthquake. It was done like this.

FIG. 10 is a block diagram showing the configuration of a gas meter according to the second embodiment of the present invention. This gas meter is configured by adding a wavelength measuring circuit 8 to the gas meter of the first embodiment shown in FIG.

The pulse signals SIG1 and SIG2 from the multistage seismoscope 1 are input to the wavelength measuring circuit 8. The wavelength measuring circuit 8 receives the input pulse signals SIG1 and SIG
The second wavelength is measured, it is detected whether the wavelength is equal to or longer than a predetermined length, and the result is sent to the controller 7.

In the above embodiment, the wavelength measuring circuit 8 includes the pulse signals SIG1 and SIG from the multi-stage seismoscope 1.
Although 2 is input, it is also possible to modify so that only one signal of SIG1 or SIG2 is input and the wavelength is measured and detected.

Next, the operation of the gas meter according to the second embodiment of the present invention will be described. That is, the earthquake determination method according to the second embodiment will be described.

FIG. 11 shows vibration due to an earthquake, but like the vibration due to impact, it shows an output waveform of the multi-stage seismoscope 1 when the time difference from the rise of the pulse signal SIG1 to the rise of the pulse signal SIG2 is short.

When an earthquake occurs, the first seismoscope 10 senses the vibration and detects the pulse signal SI as shown in FIG. 11 (a).
Output G1. As a result, the time measuring circuit 3 starts measuring the time difference. Then, when the vibration increases, the second
The seismoscope 11 has a pulse signal S as shown in FIG.
Output IG2. As a result, the time measuring circuit 3 stops measuring the time difference and the time difference is fixed. Even in the case of an earthquake, the time measuring circuit 3 does not send a signal indicating the detection result to the controller 7 unless the time difference is equal to or larger than the predetermined value. The time measuring circuit 3 holds this time difference until the vibration ends.

Similar to the first embodiment, the detection circuit 2 detects whether the waveform of the pulse signal SIG1 from the first seismic detector 10 indicates the characteristics of an earthquake and sends the detection result to the controller 7. .

The wavelength measuring circuit 8 also measures the wavelengths of the input pulse signals SIG1 and SIG2, detects whether the measured wavelengths are longer than a predetermined length, and sends the detection result to the controller 7.

In the above embodiment, the wavelength measuring circuit 8 includes the pulse signals SIG1 and SIG from the multi-stage seismoscope 1.
Although 2 is input, it is also possible to modify so that only one signal of SIG1 or SIG2 is input and the wavelength is measured and detected.

The controller 7, which has received the signal indicating the detection result from the detection circuit 2, the signal indicating the determination result from the time measuring circuit 3, and the signal indicating the detection result from the wavelength measuring circuit 8, follows the flowchart shown in FIG. The presence or absence of an earthquake is judged and the shutoff valve 4 is controlled.

That is, the controller 7 first checks whether or not there is an output signal from the detection circuit 2 (step S1).
0). Here, there is no output signal, that is, the first seismic sensor 10
When it is determined that the waveform of the pulse signal SIG1 from 1 does not indicate the characteristics of the earthquake, the process ends. On the other hand, there is an output signal, that is, the pulse signal SI from the first seismic sensor 10
When it is determined that the waveform of G1 indicates the characteristic of the earthquake, next, the presence or absence of the output signal from the time measuring circuit 3 is checked (step S11). Here, if there is an output signal from the time measuring circuit 3, that is, if it is determined that the time difference is equal to or longer than a predetermined time, it is recognized that the vibration is caused by an earthquake (step S13), and the control signal is cut off by the shut-off valve 4 The gas supply is cut off (step S14) and the process ends.

If it is determined in step S11 that there is no output signal, that is, the time difference is not longer than the predetermined time, it is next checked whether or not there is an output signal from the wavelength measuring circuit 8 (step S20). Where there is no output signal,
That is, when it is determined that the pulse signal SIG1 or SIG2 from the first seismic sensor 10 or the second seismic sensor 11 does not include a pulse having a wavelength of a predetermined length or more, it is recognized that the vibration is caused by an impact. (Step S12), the process ends.

On the other hand, it is judged that there is an output signal, that is, the pulse signal SIG1 or SIG2 from the first seismic sensor 10 or the second seismic sensor 11 contains a pulse having a wavelength longer than a predetermined length. Then, it is recognized that the vibration is caused by an earthquake (step S13), and the control signal is sent to the shutoff valve 4 to shut off the gas supply (step S1).
4), the process ends.

As described above, according to the gas meter of the second embodiment, as in the case of the gas meter of the first embodiment, after the impact is once determined to be a shock, the wavelength measuring circuit 8 outputs a pulse for a certain period of time. When the wavelength of the signal SIG1 or SIG2 is measured and a pulse with a long wavelength is detected, it is determined again as an earthquake and the shutoff valve 4 is controlled to shut off the gas supply. As a result, although it is a vibration caused by an earthquake, like the vibration caused by a shock, it is possible to avoid erroneously determining a shock when the time difference from the rise of the pulse signal SIG1 to the rise of the pulse signal SIG2 is short. The accuracy of earthquake discrimination is improved as compared with the gas meter according to the first embodiment.

The controller 7 of the gas meter according to the second embodiment described above is modified so as to be realized by the logic circuit shown in FIG. 13 (hereinafter, referred to as a first modification of the second embodiment). You can also The logic circuit of the first modified example of the second embodiment includes a 3-input AND gate 30, an inverter 31, a 3-input AND gate 32, and an inverter 33.

The output signal from the detection circuit 2 is sent to the first input terminal of the AND gate 30 and the first input terminal of the AND gate 32. The output signal from the time measuring circuit 3 is supplied to the second input terminal of the AND gate 30 and the inverter 3
3 and the output signal from the inverter 33 is sent to the second input terminal of the AND gate 32. Wavelength measuring circuit 8
The output signal from the inverter 31 and the AND gate 32
Of the inverter 31 and the output signal from the inverter 31 is sent to the third input terminal of the AND gate 30.

With the above structure, the AND gate 30 outputs an active signal when vibration due to impact occurs, and the AND gate 32 outputs an active signal when vibration due to an earthquake occurs. Therefore, by controlling the shutoff valve 4 with the output signal of the AND gate 32, the gas supply can be shut off only in the event of an earthquake, and the gas supply can be prevented from being shut off by vibration due to impact. According to the first modification of the second embodiment, the controller 7 can be configured with only a small number of logic elements, and it is not necessary to use a microcomputer or the like. Therefore, the gas meter can be made simple and inexpensive. .

(Third Embodiment) In the gas meter of the third embodiment, in the case of vibration caused by an earthquake, a pulse having a wavelength characteristic of the seismic wave is repeatedly output as compared with the case of vibration caused by impact. It was made paying attention to what is done. That is, even when the gas meter of the first embodiment determines that a shock occurs, when the pulse signal output from the multistage seismoscope 1 outputs a pulse having a wavelength that is a characteristic of an earthquake wave a predetermined number of times or more. Was decided to be an earthquake.

FIG. 14 is a block diagram showing the structure of a gas meter according to the third embodiment of the present invention. This gas meter is configured by adding a counter circuit 9 to the gas meter of the first embodiment (see FIG. 1).

The counter circuit 9 counts the number of times the detection circuit 2 detects a pulse having a predetermined width or more within a predetermined time,
It is detected whether or not the count value has exceeded a predetermined value, and the detected value is sent to the controller 7.

Next, the operation of the gas meter of the third embodiment of the present invention will be described. That is, the earthquake determination method according to the third embodiment will be described.

FIG. 15 shows the vibration caused by an earthquake, but like the vibration caused by a shock, it shows the output waveform of the multi-stage seismoscope 1 when the time difference from the rise of the pulse signal SIG1 to the rise of the pulse signal SIG2 is short.

When an earthquake occurs, the first seismoscope 10 senses the vibration and detects the pulse signal SI as shown in FIG.
Output G1. As a result, the time measuring circuit 3 starts measuring the time difference. Then, when the vibration increases, the second
The seismoscope 11 has a pulse signal S as shown in FIG.
Output IG2. As a result, the time measuring circuit 3 stops measuring the time difference and the time difference is fixed. Even in the case of an earthquake, the time measuring circuit 3 does not send a signal indicating the detection result to the controller 7 unless the time difference is equal to or larger than the predetermined value. The time measuring circuit 3 holds this time difference until the vibration ends.

Similar to the first embodiment, the detection circuit 2 detects whether the waveform of the pulse signal SIG1 from the first seismic sensor 10 indicates the characteristics of an earthquake and sends the detection result to the controller 7. .

Further, the counting circuit 9 counts the number of times the detection circuit 2 detects a pulse having a predetermined width or more within a predetermined time, and when it detects that the count value becomes a predetermined value or more, it outputs the detection result. Send to controller 7.

In the above embodiment, the counter circuit 9
Are pulse signals SIG1 and SIG from the multi-stage seismoscope 1.
Although the output of the detection circuit 2 to which 2 is input is input, it may be modified to measure and detect the number of detections of the output of the detection circuit 2 to which only one signal of SIG1 or SIG2 is input. It is possible.

The controller 7, which has received the signal indicating the detection result from the detection circuit 2, the signal indicating the determination result from the time measuring circuit 3, and the signal indicating the detection result from the counter circuit 9, follows the earthquake according to the flow chart shown in FIG. Then, the shutoff valve 4 is controlled.

That is, the controller 7 first checks whether or not there is an output signal from the detection circuit 2 (step S1).
0). Here, there is no output signal, that is, the first seismic sensor 10
When it is determined that the waveform of the pulse signal SIG1 from 1 does not indicate the characteristics of the earthquake, the process ends. On the other hand, there is an output signal, that is, the pulse signal SI from the first seismic sensor 10
When it is determined that the waveform of G1 indicates the characteristic of the earthquake, next, the presence or absence of the output signal from the time measuring circuit 3 is checked (step S11). Here, if there is an output signal from the time measuring circuit 3, that is, if it is determined that the time difference is equal to or longer than a predetermined time, it is recognized that the vibration is caused by an earthquake (step S13), and the control signal is cut off by the shut-off valve 4 The gas supply is cut off (step S14) and the process ends.

In step S11, there is no output signal,
That is, if it is determined that the time difference is not longer than the predetermined time, then the presence or absence of the output signal from the counting circuit 9 is checked (step S30). Here, when it is determined that there is no output signal, that is, the pulse signal SIG1 or SIG2 from the first seismic sensor 10 or the second seismic sensor 11 does not include a predetermined number or more of pulses indicating the characteristics of the earthquake, Recognize that the vibration is due to impact (step S12),
The process ends.

On the other hand, it is judged that there is an output signal, that is, the pulse signal SIG1 or SIG2 from the first seismic detector 10 or the second seismic detector 11 contains a predetermined number or more of pulses showing the characteristics of the earthquake. Then, it is recognized that the vibration is caused by an earthquake (step S13), and the control signal is sent to the shutoff valve 4
To shut off the gas supply (step S1
4), the process ends.

As described above, according to the gas meter of the third embodiment, similarly to the gas meter of the first embodiment, the pulse indicating the characteristic of the earthquake is determined by the counting circuit 9 after the impact is once determined to be a shock. When it is detected that more than a few are included, it is judged again as an earthquake and the shutoff valve 4 is controlled to shut off the gas supply. As a result, although it is a vibration caused by an earthquake, like the vibration caused by a shock, it is possible to avoid erroneously determining a shock when the time difference from the rise of the pulse signal SIG1 to the rise of the pulse signal SIG2 is short. The accuracy of earthquake discrimination is improved as compared with the gas meter according to the first embodiment.

The controller 7 of the gas meter of the third embodiment described above is modified so as to be realized by the logic circuit shown in FIG. 17 (hereinafter, referred to as a first modification of the third embodiment). You can also The logic circuit of the first modification of the third embodiment includes a 3-input AND gate 40, an inverter 41, a 3-input AND gate 42, and an inverter 43.

The output signal from the detection circuit 2 is sent to the first input terminal of the AND gate 40 and the first input terminal of the AND gate 42. The output signal from the time measuring circuit 3 is supplied to the second input terminal of the AND gate 40 and the inverter 4
3 and the output signal from the inverter 43 is sent to the second input terminal of the AND gate 42. Counting circuit 9
The output signal from the inverter 41 and the AND gate 42
To the third input terminal of the AND gate 40, and the output signal from the inverter 41 is sent to the third input terminal of the AND gate 40.

With the above configuration, the AND gate 40 outputs an active signal when vibration due to impact occurs, and the AND gate 42 outputs an active signal when vibration due to an earthquake occurs. Therefore, by controlling the shutoff valve 4 by the output signal of the AND gate 42, the gas supply can be shut off only in the event of an earthquake, and the gas supply can be prevented from being shut off by the vibration due to the impact. According to the first modification of the third embodiment, the controller 7 can be configured with only a small number of logic elements, and it is not necessary to use a microcomputer or the like, so that the gas meter can be made simple and inexpensive. .

In each of the above-mentioned embodiments, the multi-stage seismoscope has a structure in which the first seismoscope 10 and the second seismoscope 11 are integrally formed, but they are separately formed and are constructed by combining the signal lines. However, various modifications are possible within the scope of the claims.

[0070]

As described in detail above, according to the present invention,
By distinguishing an earthquake from an impact, it is possible to provide a gas meter that can reliably shut off the supply of gas only in the event of an earthquake and an earthquake determination method that can distinguish an earthquake from an impact.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a gas meter according to a first embodiment of the present invention.

FIG. 2 is a diagram conceptually showing the structure of a multistage seismoscope used in the gas meter according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a general relationship between a shock wave and a pulse signal output by a multi-stage seismoscope.

FIG. 4 is a diagram illustrating a general relationship between seismic waves and pulse signals output by a multi-stage seismoscope.

FIG. 5 is a timing chart explaining the operation of the time measuring circuit used in the gas meter according to the first embodiment of the present invention.

FIG. 6 is a waveform diagram showing a pulse signal output from the multi-stage seismoscope when an earthquake occurs in the gas meter according to the first embodiment of the present invention.

FIG. 7 is a waveform diagram showing a pulse signal output by the multi-stage seismoscope when there is an impact in the gas meter according to the first embodiment of the present invention.

FIG. 8 is a flowchart illustrating an operation of a controller included in the gas meter according to the first embodiment of this invention.

FIG. 9 is a circuit diagram showing a modified example of the controller included in the gas meter according to the first embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a gas meter according to a second embodiment of the present invention.

FIG. 11 is a waveform diagram showing a pulse signal output from the multi-stage seismoscope when an earthquake occurs in the gas meter according to the second embodiment of the present invention.

FIG. 12 is a flowchart illustrating an operation of a controller included in the gas meter according to the second embodiment of this invention.

FIG. 13 is a circuit diagram showing a modified example of the controller included in the gas meter according to the second embodiment of the present invention.

FIG. 14 is a block diagram showing a configuration of a gas meter according to a third embodiment of the present invention.

FIG. 15 is a waveform diagram showing a pulse signal output from the multi-stage seismoscope when an earthquake occurs in the gas meter according to the third embodiment of the present invention.

FIG. 16 is a flowchart illustrating an operation of a controller included in the gas meter according to the third embodiment of the present invention.

FIG. 17 is a circuit diagram showing a modified example of the controller included in the gas meter according to the third embodiment of the present invention.

[Explanation of symbols]

1 ... Multi-stage seismoscope, 2 ... Detection circuit, 3 ... Time measurement circuit, 4
... shut-off valve, 5 ... communication I / F, 6 ... display section, 7 ... controller, 8 ... wavelength measuring circuit, 9 ... counter circuit, 10 ... first
Sensor, 11 ... Second seismic device.

Continued front page    (72) Inventor Mitsunori Komaki             1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas             Within the corporation (72) Inventor Mitsuhiro Nakamura             1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas             Within the corporation (72) Inventor Minoru Seto             1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas             Within the corporation (72) Inventor Naoko Kawabata             Shiokyo-ku, Kyoto-shi, Kyoto Prefecture             801 Kudo-cho Omron Co., Ltd. (72) Inventor Tomohiro Kataoka             Shiokyo-ku, Kyoto-shi, Kyoto Prefecture             801 Kudo-cho Omron Co., Ltd. (72) Inventor Koji Shimomoto             Shiokyo-ku, Kyoto-shi, Kyoto Prefecture             801 Kudo-cho Omron Co., Ltd. (72) Inventor Kenji Shinohara             Shiokyo-ku, Kyoto-shi, Kyoto Prefecture             801 Kudo-cho Omron Co., Ltd. (72) Inventor Hiroto Uyama             70 Yanagicho, Saiwai-ku, Kawasaki City, Kanagawa Prefecture             Toshiba Yanagimachi Office (72) Inventor Yoshiro Ishino             70 Yanagicho, Saiwai-ku, Kawasaki City, Kanagawa Prefecture             Toshiba Yanagimachi Office (72) The inventor's lifetime             70 Yanagicho, Saiwai-ku, Kawasaki City, Kanagawa Prefecture             Toshiba Yanagimachi Office F term (reference) 2F030 CC13 CE02 CE27 CF05 CF11                       CF20                 2G064 AB19 BD17 CC27 CC28 CC46                       CC62

Claims (7)

[Claims] 1. A seismoscope which detects vibrations with different sensitivities and outputs a plurality of pulse signals corresponding to the different sensitivities, and each pulse signal from the seismoscopes has a predetermined width or more within a first predetermined time. A detection circuit for detecting whether or not a predetermined number or more of pulses are included, a time measurement circuit for measuring a time difference at the time of starting pulse output of each pulse signal from the seismic sensor, and the detection circuit within a first predetermined time. A controller that determines whether the vibration is a vibration caused by an earthquake or a vibration caused by a shock based on the time difference measured by the time measurement circuit when it is detected that a predetermined number or more of pulses having a predetermined width or more are detected. Gas meter characterized by. 2. The controller detects that the detection circuit includes a predetermined number or more of pulses having a predetermined width or more within a first predetermined time, and the time difference measured by the time measurement circuit is a second predetermined time. The gas meter according to claim 1, wherein when the vibration is above, it is determined that the vibration is caused by an earthquake and the gas supply is cut off. 3. A wavelength measuring circuit for measuring a wavelength of a pulse signal from the seismic sensor, wherein the controller includes a predetermined number or more of pulses having a predetermined width or more in the first predetermined time in the detection circuit. Detected,
And when the time difference measured by the time measuring circuit is less than a second predetermined time and the wavelength measured by the wavelength measuring circuit is a predetermined length or more, it is determined that the vibration is vibration caused by an earthquake. The gas meter according to claim 1, wherein the supply of gas is shut off. 4. A counter that counts pulses having a predetermined width or more included in the pulse signal from the seismoscope, wherein the controller includes a predetermined number of pulses having a predetermined width or more within the first predetermined time in the detection circuit. Is detected to include
Further, when the time difference measured by the time measuring circuit is less than a second predetermined time and the counter counts a predetermined value or more, it is determined that the vibration is vibration caused by an earthquake, and gas supply is cut off. The gas meter according to claim 1, wherein: 5. A first step of detecting vibrations with different sensitivities and outputting a plurality of pulse signals corresponding to different sensitivities; and each pulse signal having a predetermined number of pulses having a predetermined width or more within a first predetermined time. A second step of detecting whether or not to include the above, a third step of measuring a time difference at the time of starting pulse output of each pulse signal, and a predetermined number or more of pulses having a predetermined width or more within the first predetermined time And a fourth step of determining, when detected, whether the vibration is a vibration caused by an earthquake or a vibration caused by an impact based on the time difference measured in the third step. 6. The fourth step detects that a predetermined number or more of pulses having a predetermined width or more are included in the first predetermined time in the second step, and the time difference measured in the third step is 6. The earthquake determination method according to claim 5, wherein when the predetermined time is 2 or more, it is determined that the vibration is caused by an earthquake and gas supply is cut off. 7. The method further comprises a fifth step of measuring the wavelength of the pulse signal output in the first step, wherein the fourth step includes a pulse of a predetermined width or more within a first predetermined time in the second step. When it is detected that a predetermined number or more are included, the time difference measured in the third step is less than a second predetermined time, and the wavelength measured in the fifth step is a predetermined length or more, the vibration is The earthquake determination method according to claim 5, wherein it is determined that the vibration is caused by an earthquake, and the gas supply is cut off.