JPH09273953A - Gasmeter having seismoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress useless power consumption by accurately controlling a cut-off valve according to the degree of earth quake. SOLUTION: In a gasmeter having at least a control means 50 to control a cut-off valve 40 provided in a gas piping by analyzing the output of a seismoscope 20, the seismoscope 20 has a detection circuit 30 which senses a specified low vibration to output a digital seismic sensing output and also generates an analog earthquake sensing output to detect the degree of vibration of the analog earthquake sensing output and a power source control circuit 60 to control the supply of a power source thereto. The control means 50 works the power control circuit 60 to supply the power source according to the digital earthquake sensing output and controls the shutting or returning of the cut-off valve 40 according to the degree of vibration detected by the detection circuit. When the analog earthquake sensing output indicates the vibration above the first vibration, the cut-off valve 40 is shut by above control and when the earthquake sensing output indicates the vibration exceeding the second vibration larger than the first vibration, the return after the shutting of the cut-off valve 40 is forbidden.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas meter having a seismic sensor, and in particular, it takes out a digital signal and an analog signal from the seismic sensor according to the vibration of an earthquake, and makes a predetermined judgment for each signal. The present invention relates to a signal processing method for a gas meter and a seismic sensor, which can perform optimal control of shutoff and return of a shutoff valve according to the degree of vibration obtained from an analog signal.

[0002]

2. Description of the Related Art A gas meter provided between a gas supply pipe and an indoor pipe of each home or the like usually has a seismic sensor inside, and the seismic sensor senses a certain degree of vibration and outputs a sensing signal. When output, the microcomputer analyzes the sensed signal according to a predetermined algorithm, and closes the shut-off valve if necessary.

[0003] Disasters caused by earthquakes are difficult to predict, but if there is no damage at least on the upstream side of the gas meter and gas can be supplied, and there is damage to indoor piping downstream of the gas meter, If gas is supplied to the indoor piping after an earthquake, air and gas may mix and cause an explosion at the time of ignition. Therefore, it is required to forcibly close the gas shut-off valve when a certain strong earthquake occurs.

Conventionally, the seismoscope mounted on the gas meter supplies the microcomputer with an output to inform that the seismic shock has occurred when a seismic vibration exceeds a certain level. The microcomputer analyzes the sensed signal according to a predetermined algorithm, and when it determines that it is due to an earthquake, it closes the shutoff valve. In the case of the conventional one-way shutoff valve, the subsequent restoration is performed manually.

FIG. 7 is a diagram showing an example of the seismic sensor. In FIG. 7, (1) normal state, (2) earthquake state, and (3) tilt state are shown, respectively. In brief, the structure is such that a seismic part 11 is suspended from a support 10, and a sphere 12 is placed on a mortar-shaped saucer 15 in the seismic part 11. As shown in FIG. 2B, when a quake occurs due to an earthquake, the sphere 12 rolls sideways, and pushes up the portion 13 of the switch 14 above the sphere 12 to turn on the switch 14. Therefore, by optimizing the shape and weight of the sphere 12, the shape of the tray 15, the shape of the part 13, and the like, it is possible to generate an output signal only when a vibration having a seismic intensity of 5 or more is detected. FIG. 7 (3) shows that the seismic sensing unit 11 is kept horizontal even when the gas meter equipped with the seismic sensor is tilted.

FIG. 8 is a diagram for explaining an algorithm for judging an earthquake based on the output of the seismoscope shown in FIG. When the seismoscope senses shaking with seismic intensity of 5 or more, the sensing output is supplied to the microcomputer in the gas meter. Microcomputers usually analyze seismic sensor outputs so that they do not hypersensitively react to vibrations caused by shocks other than earthquakes to close the shutoff valves. The algorithm is, for example, when an ON state that continues for 30 msec or more within 3 seconds from the time when the first OFF state is changed to the ON state is 4 times.
It is whether or not there are three or more times with an OFF state that continues for 0 msec or more. Therefore, it is detected that the seismic intensity is 5 or more at the time indicated by the arrow in the figure. Usually, the vibration due to an earthquake is a low-frequency vibration close to a sine wave, whereas the vibration due to an impact is a high frequency. Therefore, according to the above algorithm, the microcomputer does not detect an earthquake due to shock-induced vibration.

[0007]

However, in the above-mentioned conventional method, it is necessary to take sufficient earthquake countermeasures in the following points.

First, there is a slight variation in the vibration that generates a sensing output due to a variation in the manufacturing of the vibrator. Usually, vibration acceleration 0.08-0.25G corresponding to seismic intensity 5
It is designed to output a sensing output when vibration occurs at a faster acceleration than the range of. However, due to manufacturing variations, there are rare cases where a sensing output is generated by a vibration near the lower limit of seismic intensity 5 and a case where the sensing output is generated near the upper limit, and there is a slight variation in the level of vibration where the shut-off valve closes. is there.

Second, the sensing output of the seismic sensor is a digital value indicating whether or not there is a seismic intensity of 5 or more, and the microcomputer recognizes whether the seismic intensity is 6 or 7, or higher. Can not do it. Therefore, it is necessary to shut off the shutoff valve on the safer side. However, there may be a case where the shut-off valve may be returned without damage to the piping even at a seismic intensity of about 5. A similar case may occur when the seismic intensity is about 6. In such a case, it may be possible to immediately restore the shutoff valve, but the conventional gas meter cannot deal with such a situation in detail.

Thirdly, in the case of an extremely strong earthquake, for example, a seismic intensity of 7 or more, it is a safer process to prevent the shutoff valve from being restored by any means. There are cases.

Therefore, an object of the present invention is to detect the degree of seismic vibration, and to perform the processing of shutting off or returning the shut-off valve more accurately according to the degree of the seismic vibration. To provide.

A further object of the present invention is to provide a gas meter which can detect the degree of earthquake vibration while suppressing the power consumption of the battery in the gas meter as much as possible.

[0013]

According to the present invention, the above object is to provide a seismic sensor and control means for analyzing the output of the seismic sensor to control a shutoff valve provided in a gas pipe. In the gas meter having at least, the seismic sensor detects a predetermined degree of vibration and generates a first seismic output, and generates a second seismic output according to the degree of vibration, A detection circuit for detecting the degree of vibration of the seismic output and a power supply control circuit for controlling the supply of power to the detection circuit, the control means controlling the power supply according to the first seismic output. This is achieved by providing a gas meter characterized in that the circuit is supplied with power and the shutoff valve is shut off and reset according to the degree of vibration detected by the detection circuit.

The control means turns on the power supply control circuit by the first seismic output which is the low vibration contact output of the seismic sensor to supply power to the detection circuit, and the detection circuit, for example, analog according to the degree of seismic intensity. The degree of vibration can be detected from the second seismic output of the signal wave, and the shutoff valve can be controlled according to the degree of vibration. Therefore, the power consumption of the battery mounted on the gas meter can be minimized.

The shutoff valve is controlled such that the shutoff valve is shut off when the degree of vibration detected by the detection circuit is equal to or greater than the first vibration, and the seismic output is larger than the first vibration. It is carried out so as to prohibit the return of the shut-off valve after shut-off when there is a seismic vibration of two or more. Therefore, more appropriate control can be performed according to the degree of vibration.

When the shut-off valve is bidirectionally controllable, the shut-off valve is controlled by shutting off the shut-off valve when the vibration detected by the detection circuit is the first vibration or more. After performing the self-diagnosis including the leakage diagnosis of the gas pipe after the shutoff, when no abnormality is detected, the shutoff valve is returned when the degree of the shaking is within the range of the first shaking, A manual return of the shut-off valve is permitted during a large second vibration, and a return of the shut-off valve is prohibited during a third vibration greater than the second vibration. Therefore, more appropriate control can be performed according to the degree of vibration.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. However, the technical scope of the present invention is not limited to this embodiment.

FIG. 1 is a block diagram schematically showing the structure of a gas meter according to this embodiment. The seismoscope 20 according to the present embodiment has a seismoscope that outputs a digital signal 20d such as ON when the vibration is equal to or more than a predetermined vibration as described with reference to FIG. It is composed of a seismic sensor that outputs an analog signal wave 20a that is reproduced as it is.

Various structures can be applied to this analog seismic sensor. As an example thereof, there is a method in which a piezoelectric element is applied on a plastic film and the vibration of the plastic film in response to vibration is detected by a voltage change between the piezoelectric elements. Therefore, the output analog signal wave 20a is a wave that reproduces a tremor whether it is an earthquake or a shock. Such a piezoelectric element can reduce manufacturing variations as compared with the above-described combination of the plate and the sphere of the seismic sensor.

As another example, it is also possible to place a coil adjacent to a magnet that moves according to vibration and detect the induced electromotive force generated in the coil. Also in this case, a similar analog signal wave 20a can be output.

Reference numeral 30 is a circuit for detecting the amplitude of the analog signal wave 20a. The amplitude of the analog signal wave 20a having an amplitude according to the magnitude of the vibration (generally represented by acceleration) is detected, and the microcomputer 5 as a control means is detected.
It is converted into the optimum signal for input of 0 and supplied. For example, the magnitude of the amplitude is converted into a digital signal, or the digital output bit assigned corresponding to the magnitude of the amplitude is converted.

The power supply of the amplitude detecting circuit 30 is controlled by the power supply control circuit 6 so that power is not consumed in the normal state.
It is controlled by 0. In the example of FIG. 1, a circuit which is composed of a transistor as an example of the power supply control circuit 60 and is turned on by the microcomputer 50 to supply power when amplitude detection is required is shown.

As shown in the conventional example, the microcomputer 50 detects the digital output 20d from the seismic sensor 20 by using the above-mentioned algorithm to detect a vibration having a seismic intensity of 4 or more, for example.
The power supply control circuit 60 is turned on to drive the amplitude detection circuit 30. Then, the analog signal wave 20 from the seismic sensor 20
If the amplitude of a is equal to or larger than a predetermined value, the shutoff valve described later is controlled according to the magnitude of the amplitude.

The gas meter shown in FIG. 1 does not consume battery power in the normal state. The seismic sensor 20 basically has no power source, and the circuit 30 for detecting the amplitude of the analog signal wave 20a is also disconnected from the power source by the power source control circuit 60. Then, according to the tendency that the detection of an earthquake is accompanied by a full-scale large shake after the initial shake, when the microcomputer 50 detects the initial shake of the earthquake through the digital signal 20d, the power supply to the amplitude detection circuit 30 is turned on. After turning on, the magnitude of a large sway thereafter is detected from the analog signal wave, and the predetermined shutoff valve 40 is controlled according to the degree of the vibration.

FIG. 2 is a chart showing an example of a process for shutting off the shutoff valve 40 and then returning it.
In this example, a bidirectional shutoff valve is used, the shutoff valve is not closed when the seismic intensity is determined to be 4 or less, and immediately shut off when the seismic intensity is determined to be 5 or more. I try to close the valve. If it is determined that the seismic intensity is within the range of 5, the microcomputer 50 performs self-diagnosis such as gas leakage after shutting off, and automatically restores if there is no abnormality. Also, if it is determined that the seismic intensity is within the range of 6, the automatic recovery after interruption is prohibited,
Only manual reversion is allowed. If the seismic intensity is in the range of about 6, there is a possibility that unpredictable injuries may have occurred, and only manual recovery after manually checking for injuries that cannot be detected by the self-diagnosis program is allowed. When it is determined that the seismic intensity is in the range of 7 or more, the shutoff valve is prohibited from being returned automatically or manually.

The example shown in FIG. 2 is an example, and other various processes are conceivable. However, basically, in the case of an earthquake that is more than a tremor in the range where an injury may occur due to the earthquake, the shutoff valve is forcibly closed once, and if no abnormality is found by the self-diagnosis after that, it will be restored. It is advisable to prohibit the return of the shut-off valve when there is a tremor that is extremely likely to cause an injury.

FIG. 3 is a flow chart of a control program in the microcomputer 50 for processing the signal from the seismic sensor 20 as described above.

When a vibration having an acceleration of seismic intensity of 4 or more occurs due to an earthquake or some other reason, a digital signal 20d is supplied to the microcomputer 50 from the digital seismic sensor. The microcomputer 50 detects the vibration due to the earthquake by the algorithm as shown in FIG. 8 (S1). Therefore, high-frequency vibrations due to shocks other than earthquakes are eliminated at this stage. When the shaking of the seismic intensity of about 4 due to the earthquake is detected by the digital signal 20d from the digital vibration sensor, the microcomputer 50 generates a control signal for turning on the power supply control circuit 60 (S).
2).

As a result, power is supplied to the amplitude detection circuit 30, and the analog signal wave 20a accompanying a large swing thereafter is generated.
Detect the amplitude value of. For example, the detected digital value is supplied to the microcomputer 50, and it is determined whether the seismic intensity is 5 or more (S3).

When it is determined that the seismic intensity is shaking of 5 or more, the microcomputer 50 immediately causes the shutoff valve 40 to move.
To the electromagnetic coil of the cutoff valve to cut off the current (S4). After that, for example, a self-diagnosis is performed by the self-diagnosis program in the microcomputer 50 such as whether or not a leak has occurred in the indoor piping system downstream from the gas meter (S5).

When it is determined that there is no abnormality as a result of self-diagnosis (S6), the shutoff valve 4 is selected according to the determined seismic intensity.
Return processing of 0 is performed (S7).

When the seismic intensity is about 5, for example, the shut-off valve is automatically restored immediately if no abnormality is recognized by the self-diagnosis program. By adopting the bidirectional shutoff valve, it is possible to open the shutoff valve by issuing a return command signal 42 from the microcomputer 26 and passing a current through the electromagnetic coil for returning the shutoff valve (S8).

When the seismic intensity is about 6, for example, the control is performed so that a human check process is required in addition to the self-diagnosis program. Therefore, in order to set the automatic recovery prohibition mode in the microcomputer 50, for example, the automatic recovery prohibition flag is set to 1 (S9), and when the manual recovery is performed thereafter (S10), the recovery of the shutoff valve is allowed (S1).
1). The automatic recovery prohibition flag is provided in, for example, a register in the microcomputer or an area in the RAM.

When the seismic intensity is about 6, there is a possibility that an unpredictable injury that cannot be detected by the self-diagnosis program has occurred. Therefore, the shut-off valve 40 is opened mechanically or by the return command signal 42 from the microcomputer 50 by the manual return signal that is first issued by the person after the actual site check.

When the seismic intensity is, for example, 7 or more, there is a high possibility that the piping system is injured. Therefore, for any reason, the shutoff valve must be checked unless a certain level of inspection is performed. Do not allow the return of. Therefore, the return prohibition mode is set in the microcomputer 50 (S
12). For example, the return prohibition flag that prohibits both automatic and manual return is set to 1. As a result, the microcomputer 50 is controlled so as to ignore the instruction even if the return instruction is input. Further, if necessary, an alarm is displayed on the display of the gas meter (S13). The above-described recovery prohibition mode is similarly set when an abnormality is detected as a result of self-diagnosis. The return prohibition mode allows the flag to be reset to 0 only after a certain level of inspection is performed.

Various modifications can be considered for the above control of the shutoff valve. For example, the seismic sway range can be divided into arbitrary ranges, and optimal processing of each shutoff valve can be performed. If the shut-off valve used is a one-way shut-off valve instead of a two-way shut-off valve, for example, shut off immediately if the seismic intensity is 5 or more, and allow manual return if the seismic intensity is 5 or 6, and manually return the shut-off valve if the seismic intensity is 7 or more. A control method is conceivable in which the microcomputer detects from the counter electromotive force generated in the electromagnetic coil of the shutoff valve and shuts off the shutoff valve again to prohibit the return.

FIG. 4 is a detailed circuit example of the gas meter according to the embodiment of the present invention. The above-described digital vibration sensor 22 and analog vibration sensor 24 are provided in the vibration sensor 20. Both are shown in simplified diagrams,
The analog seismic transducer 24 is composed of the magnet and the coil described above, and outputs the analog signal wave 20a according to the magnitude of the vibration. Further, the digital seismic transducer 22 has a structure as shown in FIG. 7, and outputs a digital signal 20d which indicates that a vibration is sensed when the closed loop is turned on.

In the circuit 30 for detecting the amplitude of the analog signal wave 20a, a low pass filter 31 for cutting high-frequency components of shaking other than an earthquake, an amplifier 32 for amplifying its output, and an amplitude size are provided. A voltage comparator 33 for comparing with a preset reference value is provided. Then, a power supply control circuit 60 that supplies power to these circuits is controlled by the microcomputer 50.

FIG. 5 is a circuit diagram showing the voltage comparison circuit 33 in detail. In this example, three comparators 34, 35, and 36 are provided in the voltage comparison circuit 33, and their outputs are input ports P1- of the microcomputer 50.
It is supplied to P3. In the three comparators, the reference voltage is generated by resistance division, and each reference voltage V1, V2, V3 is generated.
Are set to values corresponding to an amplitude of 5 or more, an amplitude of 6 or more, and an amplitude of 7 or more, respectively. Therefore,
If the seismic intensity is 5, only the output 1 is at the H level, if the seismic intensity is 6, the outputs 1 and 2 are at the H level, and if the seismic intensity is 7, all of the outputs 1, 2, and 3 are at the H level. Therefore, the magnitude of the vibration can be detected from the combination of the input ports on the microcomputer 50 side.

FIG. 6 is a detailed circuit diagram of the power supply control circuit 60. The power control circuit 60 includes a power switch section 61,
It is composed of a power source stabilizing unit 62 and a power source voltage dividing unit 63. In the power switch section 61, a switching transistor Q1 is provided.
Is provided, and the microcomputer 50 has an initial seismic intensity of 4
When the above shaking is sensed, the output port P0 is set to L level and the transistor Q1 is turned on. Power stabilization unit 62
Then, the comparator 64 compares the divided voltage value of the collector potential of the transistor Q2 with the reference voltage Vref, and controls the base current (voltage) of the stabilizing transistor Q2 via the transistor Q3 so that the collector potential becomes constant. Then, the stabilized collector potential is applied to the resistors R4 and R
The voltage is divided by 5 and three voltage values are supplied to the amplitude detection circuit 30. The capacitors C1, C2 and C3 are smoothing capacitors.

By the power supply control circuit 60, a power supply VDD from a battery (not shown) mounted on the gas meter.
Is switched under the control of the microcomputer 50, and a stable voltage is supplied to the amplitude detection circuit 30 only when necessary.

Returning to FIG. 4, the operation will be described. In a normal state, the microcomputer 50 is in a rest state, and when the earthquake shakes, the low vibration contact output of the digital seismic sensor 22 is first sensed. The output restarts the microcomputer 50, issues a command to the power control circuit 60,
Turn on the power. Then, the amplitude detection circuit 30 causes the voltage comparison circuit 33 to respond to the magnitude of the amplitude of the analog signal wave 20a.
The microcomputer 5 sends a signal according to the magnitude of the shaking.
Supply 0. Then, by controlling the shutoff valve described above,
After that, if there is no low vibration contact output from the seismoscope 22 for a certain period of time or more, the power supply control circuit 60 is turned off and the self-confidence state is returned to.

[0043]

As described above, according to the present invention, the degree of earthquake intensity can be detected, and the shutoff valve can be optimally controlled according to the degree of intensity. Therefore, safer and more appropriate safety management can be performed.

Further, since the power supply of the amplitude detection circuit for the analog signal necessary for that is in the off state until the initial shaking of the earthquake occurs, the power of the battery is not wastefully consumed.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a gas meter according to an embodiment of the present invention.

FIG. 2 is a chart showing an example of control of a shutoff valve.

FIG. 3 is an operation flowchart diagram of the embodiment of the present invention.

FIG. 4 is a configuration block diagram of a gas meter according to another embodiment of the present invention.

5 is a detailed circuit diagram of the voltage comparison circuit of FIG.

FIG. 6 is a detailed circuit diagram of the power supply control circuit of FIG.

FIG. 7 is a diagram showing an example of a conventional seismoscope.

FIG. 8 is a diagram showing an output example of a conventional seismic sensor.

[Explanation of symbols]

 20 seismic sensor 30 amplitude detection circuit 40 shutoff valve 50 control means, microcomputer 60 power supply control circuit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Osamu Sakakura 1-6-1, Nihonbashihonmachi, Chuo-ku, Tokyo Nikkoshi Co., Ltd. (72) Inventor Hiroaki Itoi 1-6-1, Nihonbashihonmachi, Chuo-ku, Tokyo Nikkoshi Within the corporation

Claims (5)

[Claims] 1. A gas meter comprising at least a seismic sensor and control means for analyzing an output of the seismic sensor to control a shutoff valve provided in a gas pipe, wherein the seismic sensor has a predetermined vibration. A detection circuit for detecting the degree of vibration of the second seismic output by generating the first seismic output by sensing the degree of A power supply control circuit for controlling the supply of power to the detection circuit, wherein the control means causes the power supply control circuit to supply power according to the first seismic output, and is detected by the detection circuit. A gas meter, characterized in that the shutoff valve is controlled to be shut off and returned according to the degree of vibration that occurs. 2. The gas meter according to claim 1, wherein the control means shuts off the shut-off valve when the degree of the vibration detected by the detection circuit is the first vibration or more, and the seismic output is It is characterized in that the shut-off valve is prohibited from returning after shut-off in the case of a second-greater-than-first-shake vibration that is greater than the first-shock. 3. The gas meter according to claim 1, wherein the shutoff valve is bidirectionally controllable, and the control means controls the vibration level detected by the detection circuit to be greater than or equal to the first vibration level. When the shut-off valve is shut off, a self-diagnosis including a leak diagnosis of at least the gas pipe is performed after the shut-off, and when no abnormality is detected, the shut-off valve is restored when the degree of the shaking is within the first shaking range. However, when the second vibration is larger than the first vibration, the shut-off valve is allowed to be manually returned, and when the third vibration is larger than the second vibration, the shut-off valve is prohibited to be returned. Is characterized by. 4. The gas meter according to claim 1, wherein the second seismic output is an analog signal wave corresponding to vibration, and the detection circuit has an amplitude of the analog signal wave larger than a predetermined reference value. It is characterized by having a comparator for detecting whether or not. 5. The gas meter according to claim 1, wherein the second seismic output is an analog signal wave corresponding to a vibration, and the detection circuit is a low-frequency detector that removes a predetermined high frequency of the analog signal wave. It has a pass filter and a comparator for detecting the amplitude of the output wave of the low pass filter.