JPH09250747A - Gas meter having seismic sensor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly perform the shutoff of a shutoff valve or the return prohibition by shutting off the shutoff valve when the output of a comparator indicates the oscillation over the first oscillation, and prohibiting the return after shutting off the shutoff valve when the output of the comparator indicates the oscillation over the second oscillation larger than the first one. SOLUTION: The analog signal wave 21 of a seismic sensor device 20 is outputted to an LPF 22, and the output wave 23 of the LPF 22 is fed to comparators 42, 44, 46, respectively. The amplitude of the fed output wave 23 is compared with the reference value by the respective comparators 42, 44, 46, and the signal of the compared result is fed to a microcomputer 26. The microcomputer 26 generates the shutoff command signal to the shutoff valve 40 when the oscillation indicates the seismic intensity of >=5, and feeds the current to an electromagnetic coil for shutoff. In addition, in the case of the seismic intensity of >=7, the return prohibitive mode is made in the microcomputer 26, and the return of the shutoff valve 40 after shutoff is prohibited. Thus, the shutoff of the shutoff valve 40 and the return prohibition can be correctly performed.

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 vibration sensor, and in particular, an analog signal corresponding to the vibration of the earthquake is extracted from the vibration sensor, and an optimum shut-off valve is obtained according to the degree of the vibration obtained from the analog signal. The present invention relates to a signal processing method for a gas meter and a seismic sensor capable of controlling shutoff and recovery of a gas.

[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 sensing signal according to a predetermined algorithm, and closes the shut-off valve when it is determined that the signal is caused by an earthquake. In the case of the conventional one-way shutoff valve, the subsequent restoration is performed manually.

FIG. 4 is a diagram showing an example of the seismic sensor. In FIG. 4, (1) normal state, (2) earthquake state, and (3) tilt state are shown, respectively. The structure is simply explained by suspending a seismic sensing section 11 on a support 10. The sphere 12 is placed on a mortar-shaped saucer 15 of a predetermined shape in the seismic sensing section 11. When the tremor occurs due to an earthquake, the sphere 12 rolls sideways and is located above it, as shown in FIG. The part 13 of the switch 14 is pushed up 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. 4C shows that the seismic sensing unit 11 is kept horizontal even when the gas meter equipped with the seismic sensor is tilted.

FIG. 5 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 a shake with a seismic intensity of 5 or more, the sensor 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, it is whether or not there are three or more ON states that continue for 30 msec or more within 3 seconds from the time when the ON state is turned on from the first OFF state, and OFF states that continue for 40 msec or more. Therefore, seismic intensity 5 at the time of the arrow in the figure
The above earthquakes are detected. Normally, the earthquake vibration is a low frequency vibration close to a sine wave,
Vibrations due to shocks and noise have high frequencies. Therefore,
Due to the above algorithm, the microcomputer does not detect an earthquake due to a shock or a vibration caused by noise.

[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.

[0012]

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 at least a gas meter, the seismoscope outputs an analog signal wave according to the degree of vibration, the analog signal waves are respectively input, the amplitude of the analog signal wave is set to a different reference value Comprising a plurality of comparators, the control means shuts off the shut-off valve when the output of the comparator represents a vibration of a first vibration or more,
It is achieved by providing a gas meter that prohibits the return of the shut-off valve after shut-off when the output of the comparator represents a second-shake greater than the first shake.

Further, according to another invention, at least a seismic sensor and a control means for analyzing an output of the seismic sensor to control a bidirectionally controllable shutoff valve provided in the gas pipe. In the gas meter having, the seismoscope outputs analog signal waves according to the degree of vibration, inputs the analog signal waves respectively, and compares the amplitudes of the analog signal waves with reference values set to different values. The control means shuts off the shutoff valve when the output of the comparator represents a vibration of a first vibration or more, and performs a self-diagnosis including a leakage diagnosis of at least a gas pipe after the shutoff. , When no abnormality is detected, the shut-off valve is reset when the output of the comparator is within the range of the first vibration, and when the second vibration larger than the first vibration is indicated, the shut-off valve is manually reset. To It was allowed, when representing a third vibration or more greater than said second vibration is accomplished by providing a gas meter and inhibits the return of the blocking valve.

By comparing the analog signal waves from the seismic sensor with different reference values by a plurality of comparators, it is possible to accurately determine the seismic intensity according to a combination of a plurality of outputs. Further, even if one comparator outputs a detection output due to noise or shock, the combination with other outputs is different from the expected combination, so such noise or shock can be removed.

Further, by providing a low pass filter for removing a predetermined high frequency between the seismoscope and the comparator, a high frequency signal due to noise or shock can be removed, and the seismic intensity can be determined more accurately. Can be done.

[0016]

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 configuration of a gas meter according to this embodiment. The seismoscope 20 in the present embodiment outputs an analog signal wave 21 that reproduces the strength of the vibration as it is. Various types of internal structures can be applied to the seismoscope 20. 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 21 is
It 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.

Reference numeral 22 is a low-pass filter for eliminating vibrations caused by shocks other than earthquakes. As described above, the shaking caused by an earthquake is close to a sine wave of a low frequency, while the shock and noise other than the earthquake have a higher frequency. Therefore, by removing the high frequency component, it is possible to accurately detect the earthquake motion.

Output wave 23 of low pass filter 22
Is supplied to the comparators 42, 44 and 46. In the comparator, for example, the reference value is set to the amplitude value corresponding to the lowest value in each of the vibration ranges of seismic intensity 5, 6, and 7. Therefore, when the analog signal wave 23 having an amplitude value of seismic intensity 5 or more is supplied, the comparator 42 outputs, for example, H
Output level. Further, the comparator 44 outputs, for example, an H level when the analog signal wave 23 having an amplitude value of seismic intensity 6 or more is supplied. Furthermore, the comparator 4
6 outputs an H level, for example, when the analog signal wave 23 having an amplitude value of seismic intensity 7 or more is supplied. Therefore, 3
The outputs 43, 45, 47 of the two comparators have the following combinations for each seismic intensity.

Seismic intensity 4 or less = L, L, L Seismic intensity 5 = H, L, L Seismic intensity 6 = H, H, L Seismic intensity 7 or higher = H, H, H 26 is a microcomputer corresponding to the control means, and The internal structure is a general microcomputer structure. Arithmetic circuit 28, register 30, RAM 32,
ROM 34 and interface unit 36 are internal bus BU
It is connected through S. Outputs 43, 4 supplied from the comparators 42, 44, 46 are stored in the ROM 34.
The control software for analyzing 5, 47 and performing the optimum shutoff valve processing is stored.

The microcomputer 26 receives the output of the comparator and determines, for example, seismic intensity 4 or less, seismic intensity 5, seismic intensity 6, seismic intensity 7 or more. Specifically, any one of the combinations of the outputs 43, 45, 47 described above is detected. Then, in accordance with the result of the determination, the shutoff valve 40 is shut off, and thereafter, control such as restoration is performed.

FIG. 2 is a chart showing an example of a process for shutting off the shutoff valve 40 and returning thereafter.
In this example, the shutoff valve is not closed when the seismic intensity is determined to be 4 or less, and the shutoff valve is immediately closed when the seismic intensity is determined to be 5 or more. If it is determined that the seismic intensity is within the range of 5, the microcomputer 26 performs self-diagnosis such as gas leakage after shutting off, and if there is no abnormality, automatically recovers. If it is determined that the seismic intensity is within the range of 6, the automatic return after interruption is prohibited, and only the manual return is permitted. 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 26 which processes the signal from the seismic sensor 20 as described above.

First, the occurrence of an earthquake is detected by the analog signal wave 23 output from the LPF 22 (step S0). The amplitude value of the analog signal wave 23 is compared with each reference value by each comparator, and the comparison result signal is supplied to the microcomputer 26. The microcomputer 26 recognizes the seismic intensity by decoding the combination of the comparison result signals 43, 45, 47 (step 1).
Since the seismic intensity is recognized based on the combination of the outputs of the three comparators, it is possible to reduce the possibility that the microcomputer 26 will mistakenly recognize an earthquake having a seismic intensity of 5 or more due to some noise or shock. Therefore, if the combination of the three outputs is other than the above-mentioned combination, it is determined that the outputs are not normal,
It will be ignored.

When a normal combination is recognized, the seismic intensity is 4
The shutoff valve is not closed in the following cases (step S2).

As soon as it is determined that the seismic intensity is shaking of 5 or more, the microcomputer 26 immediately causes the shut-off valve 40 to operate.
A command signal for shutting off is sent to the electromagnetic coil of the shutoff valve to shut off the electric current (step S3). After that, for example, a self-diagnosis is performed by the self-diagnosis program in the microcomputer 26 such as whether or not a leak has occurred in the indoor piping system downstream from the gas meter (step S4).

When it is determined by the self-diagnosis that there is no abnormality (step S5), the shut-off valve 40 is restored according to the determined seismic intensity (step S6).

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 from the microcomputer 26 and passing a current through the electromagnetic coil for returning the shutoff valve.

When the seismic intensity is, for example, about 6, 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 return prohibition mode in the microcomputer 26, for example, the automatic return prohibition flag is set to 1 (step S9), and when the manual return is performed thereafter (step S10), the shutoff valve is allowed to return (step S11). . The automatic recovery prohibition flag is
For example, it is provided in an area in the register 30 or the RAM 32.

If 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 is opened mechanically by a manual return signal issued only after a person actually checks the site and by a return command signal from the microcomputer 26.

If 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 26 (step S12). For example, the return prohibition flag that prohibits both automatic and manual return is set to 1. Then, if necessary, an alarm is displayed on the display unit of the gas meter (step S13). The above-described recovery prohibition mode is similarly set even 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.

[0034]

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.

Moreover, since the seismic intensity is determined by the combination of the detection signals output by the plurality of comparators, even if the analog signal wave from the seismic sensor which is easily affected by noise or shock is used, it is accurate. It is possible to judge the seismic intensity.

[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 a flowchart of a shutoff valve control program.

FIG. 4 is a diagram showing an example of a conventional seismoscope.

FIG. 5 is a diagram showing an output example of a conventional seismic sensor.

[Explanation of symbols]

 20 seismic sensor 22 low-pass filter 26 control means, microcomputer 40 shutoff valve 42, 44, 46 comparator

Claims (3)

[Claims] 1. A gas meter comprising at least a seismic sensor and a 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 degree of vibration. A plurality of comparators that output analog signal waves according to the above, respectively input the analog signal waves, and compare the amplitudes of the analog signal waves with reference values set to different values, respectively, the control means After shutting off the shut-off valve when the output of the comparator represents a vibration of a first vibration or more, and when shutting off the shut-off valve when the output of the comparator represents a vibration of a second vibration greater than the first vibration. A gas meter characterized by prohibiting the return of the gas meter. 2. A gas meter comprising at least a seismic sensor and control means for analyzing an output of the seismic sensor and controlling a bidirectionally controllable shutoff valve provided in a gas pipe. The device has a plurality of comparators that output analog signal waves according to the degree of vibration, input the analog signal waves respectively, and compare the amplitudes of the analog signal waves with reference values set to different values. The control means shuts off the shut-off valve when the output of the comparator represents a vibration equal to or more than a first vibration, and performs a self-diagnosis including a leak diagnosis of at least a gas pipe after the shut-off,
When no abnormality is detected, the shut-off valve is reset when the output of the comparator is in the range of the first vibration, and the shut-off valve is manually reset when the second vibration larger than the first vibration is displayed. A gas meter, which is permitted, and prohibits the return of the shutoff valve when a third vibration greater than the second vibration is displayed. 3. The gas meter according to claim 1 or 2, wherein a low pass filter for removing a predetermined high frequency is provided between the seismoscope and the comparator.