JPH0972964A - Seismoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable stable detection of the magnitude of an earthquake for a long time. SOLUTION: This seismoscope is provided with a seismic sensing section 10 which senses vibration as caused by an earthquake to convert the vibration to changes in the pressure of a gas, a pressure change sensor section 30 to convert the pressure change into an electrical signal and a signal processing section 40 which processes a signal outputted from the pressure change sensor section 30 to judge the presence and the magnitude of the earthquake. With the rotation of a ball body 15 caused by the vibration, an oscillation body 17 moves vertically so that the pressure varies within a gas chamber 32 of the pressure change sensor section 30. An piezo-electric thin film 34 vibrates according to the changes in the pressure to induce a fine voltage. The fine voltage is amplified by an amplifier 41 of the signal processing section 40 and converted into digital from analog by an input-output port 42 to be inputted into a microprocessor 43. The microprocessor 43 compares a pattern of a signal obtained with a specified signal pattern to judge whether the change in the pressure is attributed to the vibration of the earthquake or not and also the magnitude of quake of an earthquake.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic sensing device for detecting a vibration such as an earthquake, and more particularly to a seismic sensing device incorporated in a gas meter and outputting a seismic sensing signal for shutting off gas.

[0002]

2. Description of the Related Art In recent years, many gas meters installed in consumers' houses such as city gas have a built-in seismic sensing device which detects a vibration such as an earthquake and outputs a gas cutoff signal. An example of such a vibration-sensing device is, for example, Shoukai 61-486
Some are described in Japanese Patent No. 34. In this seismic sensor, the lower surface (concave spherical surface) of a vertically movable disk is brought into contact with the upper surface of a sphere that is rotatably housed in a box having a concave conical inner bottom surface, and is provided on the upper surface of this disk. The switch mechanism is operated by bringing the plunger into contact with the switch mechanism and moving the disk upward by horizontal swing of the sphere. Then, the pattern of the pulse signal output by turning on / off this switch mechanism is judged by a microcomputer or the like, and it is judged whether it is caused by an earthquake or another vibration (vibration caused by the passage of a vehicle, etc.). It was supposed to do.

[0003]

As described above, in the above-mentioned conventional vibration-sensing device, the switch mechanism is mechanically actuated by the swing of the sphere to output a vibration-sensing signal. The seismic signal is a pulse signal formed by turning the switch on and off. However, such a mechanism could not detect the magnitude of the earthquake because the pulse height was constant regardless of the magnitude of the earthquake. Further, since the mechanically operated electric contact is used, there is a problem that the contact resistance of the contact changes due to changes over time and the operation becomes unstable.

The present invention has been made in view of the above problems, and an object thereof is to provide a seismic sensing apparatus capable of stably detecting the magnitude of an earthquake.

[0005]

According to a first aspect of the present invention, there is provided an earthquake-sensing device, which comprises an oscillating body which oscillates due to seismic vibration, an air chamber whose internal pressure fluctuates in response to the oscillating body, and A pressure detecting means for detecting a pressure fluctuation in the air chamber and an earthquake detecting means for detecting an earthquake based on the pressure fluctuation detected by the pressure detecting means are provided.

In this vibration-sensing device, the internal pressure of the air chamber fluctuates according to the rocking motion of the rocking body that rocks due to the earthquake vibration, and the earthquake is detected by detecting this pressure fluctuation.

According to a second aspect of the present invention, there is provided the seismic response device according to the first aspect, wherein the pressure detecting means is commonly used as a gas pressure sensor provided in association with a gas meter, and further, the pressure is further reduced. The apparatus is provided with a separating unit that separates a seismic component due to an earthquake from the pressure fluctuation detected by the detecting unit, and the seismic detecting unit is configured to perform seismic detection based on the separated seismic component.

In this seismic sensing device, the seismic component due to an earthquake is separated from the pressure fluctuation detected by using a gas pressure sensor provided in association with the gas meter, and seismic detection is performed based on this seismic component.

According to a third aspect of the present invention, the seismic sensing device according to the second aspect is characterized in that the separating means is composed of a microcomputer. With this seismic device,
The processing for separating the vibration component from the detected pressure fluctuation is performed by the microcomputer.

According to a fourth aspect of the present invention, in the seismic device according to the second aspect, the separating means is constituted by a frequency band pass filter. In this seismic sensor, the frequency band filter performs the process of separating the vibration component from the detected pressure fluctuation.

[0011]

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

FIG. 1 is a cross-sectional view of the essential parts of a seismic sensing device according to an embodiment of the present invention. This vibration-sensing device includes a vibration-sensing unit 10 that senses a vibration caused by an earthquake and converts the vibration into a gas pressure fluctuation, a pressure fluctuation sensor unit 30 that converts the pressure fluctuation into an electric signal, and a pressure fluctuation sensor unit 30. A signal processing unit 40 that processes the output signal and determines the presence or absence and magnitude of an earthquake is provided.

The seismic-sensing section 10 has a box body 13 having a cylindrical side wall 11 and a conical inner bottom surface 12, an upper lid 14 airtightly joined to the upper portion of the box body 13, and rolling on the conical inner bottom surface 12. A sphere 15 movably housed in a box 13, and this sphere 1
5, a disk-shaped inner lid 16 fixed to the inner surface of the box 13 above 5.
And an oscillating body 17 that can move up and down in response to rolling of the sphere 15.
And A shaft hole 21 is formed through the central portion of the inner lid 16, and an annular inner surface 22 is formed on the lower side.
Is formed. The oscillating body 17 is fitted with a concave spherical surface 23 in contact with the top of the sphere 15, a disc portion 24 fitted in the annular inner surface 22 of the inner lid 16 with a slight clearance, and a slight gap in the shaft hole 21 of the inner lid 16. And a combined plunger 25. The rocking body 17 is vertically rockable along the shaft hole 21 and the annular inner surface 22 of the inner lid 16 in response to the rolling of the sphere 15, whereby the inner lid 16 and the upper lid 14 allow the rocking body 17 to swing. The volume of the formed air chamber 26 is changed.

The pressure fluctuation sensor portion 30 is stretched on a container body 31 having an airtight structure and an inner wall surface of the container body 31 so as to divide the interior into two air chambers 32 and 33 having substantially the same volume. And a piezoelectric thin film 34. One air chamber 32
Communicates with the air chamber 26 of the seismic sensing unit 10 through a communication pipe 36,
A small hole 35 is formed in the other air chamber 33 so as to communicate with the outside air and let the pressure in the air chamber 33 escape. The piezoelectric thin film 34 is
It is composed of a thin film piezoelectric material and thin film electrode layers formed on both surfaces thereof, and a lead wire 37 for electrically extracting a minute voltage generated by the vibration of the piezoelectric thin film 34 to the outside is electrically connected to the thin film electrode layer. .

The signal processing section 40 includes an amplifier (AMP) 41 for amplifying a minute voltage obtained through the lead wire 37,
Waveform shaping and A / D of the analog signal from the amplifier 41
An input / output port (I / O) 42 having functions such as conversion,
It is provided with a microprocessor 43 which processes a digital signal input from the input / output port 42.

Next, the operation of the vibration-sensing device having the above-mentioned structure will be described.

In normal times, that is, in the absence of earthquakes or other vibrations, the sphere 15 is stably positioned at the center of the conical inner bottom surface 12 of the box 13. Here, when some vibration is applied to the vibration-sensing device, the spherical body 15 rolls on the conical inner bottom surface 12 and pushes the concave spherical surface 23 of the rocking body 17 upward. As a result, the rocking body 17 moves upward and compresses the gas in the air chamber 26, so that the pressure in the air chamber 26 rises. This increase in pressure is transmitted to the air chamber 32 of the pressure fluctuation sensor unit 30 via the communication pipe 36, and results in pushing the piezoelectric thin film 34 toward the air chamber 33. Sphere 15 has a conical inner bottom surface 1
When trying to return to the center of 2, the oscillating body 17 descends and the pressure in the air chamber 32 decreases, so that the piezoelectric thin film 34 is pushed from the air chamber 33 side. In this way, the piezoelectric thin film 34 vibrates according to the rolling of the sphere 15.

The vibration of the piezoelectric thin film 34 induces a minute voltage having a waveform as shown in FIG. 2, for example. This minute voltage is amplified by the amplifier 41 of the signal processing unit 40, undergoes waveform shaping at the input / output port 42, is converted into a digital signal, and is input to the microprocessor 43. The microprocessor 43 compares the obtained signal pattern with a signal pattern stored in advance in a ROM (read only memory) (not shown) or the like to determine whether it is due to an earthquake tremor or some other impact or Whether or not it is due to the passage of a vehicle is determined, and the magnitude of the earthquake (sway) is determined from the amplitude of the obtained signal.

As described above, in this embodiment, the rolling motion of the spherical body 15 is converted into the vertical motion of the oscillating body 17, and this is further converted into the pressure fluctuation of the gas, and this pressure fluctuation is detected by the piezoelectric thin film 34. As a result, earthquake detection is performed, so that it is possible to detect not only the presence or absence of an earthquake but also its magnitude. In addition, since a mechanical electric switch mechanism as in the past is not necessary, it prevents the deterioration of reliability due to aging,
The life of the device can be extended.

Next, a seismic sensing device according to another embodiment of the present invention will be described.

FIG. 3 shows a main configuration of a gas meter to which a seismic sensing device according to another embodiment of the present invention is applied. In the present embodiment, the existing pressure sensor built in the gas meter is shared as a part of the seismic sensing device. The gas meter 50 includes an inlet 51, an outlet 52,
Also, a gas meter main body 53 having a gas flow meter (not shown), a gas cutoff valve, etc. (not shown) built therein, a pressure sensor unit 60 for detecting the pipe internal pressure of the gas meter main unit 53 and the pipe internal pressure fluctuation due to the earthquake, and the earthquake vibration A signal processing unit 80 that senses the presence of an earthquake and determines the presence and magnitude of an earthquake and the gas pressure in a pipe by processing a signal output from the pressure sensor unit 60 and a seismic sensing unit 70 that converts this vibration into a gas pressure fluctuation. It has and.

The pressure sensor unit 54 has a structure similar to that of the pressure fluctuation sensor unit 30 in FIG. 1, and has a container body 61 having an airtight structure and an inner wall surface of the container body 61 having substantially the same interior. A piezoelectric thin film 64 stretched so as to be divided into two air chambers 62 and 63 having a volume. One air chamber 62 communicates with the gas flow path of the gas meter main body 53 by a communication pipe 66, and the other air chamber 63 communicates with the communication pipes 67, 68.
It communicates with the earthquake-sensing part 70. A small hole 69 for introducing atmospheric pressure necessary for causing the pressure sensor unit 60 to function as a normal pressure gauge is formed at the end of the communication pipe 67. However, the holes are small enough to prevent leakage of pressure waves from the seismic sensing unit 70 described later.

The seismic sensitive section 70 has the same structure as the seismic sensitive section 10 in FIG. 1, and a duplicate description thereof will be omitted here. However, in the case of the vibration-sensing section 70, the air chamber 26 (FIG. 1) is connected to the air chamber 63 of the pressure sensor unit 60 via the communication pipes 68 and 67.
Is in communication with.

The signal processing unit 80 also has the same components as the signal processing unit 40 in FIG. That is, the amplifier 8 that amplifies the minute voltage obtained from the pressure sensor unit 60
1 and waveform shaping of analog signals from the amplifier 41 and A /
An input / output port 82 having a function such as D conversion and a microprocessor 83 for processing a digital signal input from the input / output port 42 are provided.

Next, the operation of the vibration-sensing device having the above-mentioned structure will be described.

In normal times, that is, in the absence of earthquakes or other vibrations, the sphere 15 shown in FIG. 1 is stably positioned at the center of the conical inner bottom surface 12 of the box 13, and the oscillating body 1
7 is stationary. Therefore, the pressure sensor unit 6
There is no vibration of the piezoelectric thin film 64 of 0. On the other hand, the pressure sensor unit 6
Since the tube internal pressure in the gas meter main body 53 is transmitted to the air chamber 62 of 0, the piezoelectric thin film 64 vibrates according to the fluctuation of the tube internal pressure.

Here, if some vibration is applied to the vibration-sensing portion 70 due to an earthquake or the like, the sphere 15 rolls to cause the oscillating body 17 to roll.
Moves up and down, and the pressure fluctuation in the air chamber 26 causes the air chamber 6
3, the piezoelectric thin film 34 vibrates. In this case, the frequency of vibration due to an earthquake is generally several Hz or less, and its waveform is as shown in FIG. 4 (b), for example. On the other hand, at the same time, the piezoelectric thin film 64 vibrates according to the fluctuation of the pipe internal pressure in the gas meter main body 53. The frequency of this pressure fluctuation in the pipe is generally several Hz or more, and its waveform is, for example, as shown in FIG.
As shown in (c). Therefore, as shown in FIG. 4A, for example, the piezoelectric thin film 64 outputs a minute voltage corresponding to the vibration in which the pressure fluctuation due to the vibration sensed by the vibration sensing unit 70 and the fluctuation in the pipe pressure are superimposed. become.

The minute voltage output from the piezoelectric thin film 64 is amplified by the amplifier 81 of the signal processing unit 80, and the input / output port 8
In step 2, the waveform is shaped and converted into a digital signal, which is input to the microprocessor 83. The microprocessor 83 separates the obtained signal into a vibration component from the seismic sensing unit 70 as shown in FIG. 4B and a pipe pressure component as shown in FIG. 4C. Then, the pattern of the separated vibration component from the vibration-sensing section 70 is compared with a signal pattern such as a ROM (not shown) to determine whether it is caused by an earthquake vibration or some other impact or the passage of a vehicle. At the same time, the magnitude of the earthquake (shake) is determined from the amplitude of the obtained signal. At the same time, the signal processing unit 80 detects the pipe internal pressure based on the separated pipe internal pressure component.

As described above, in the present embodiment, the existing pressure sensor built in the gas meter is shared as a part of the vibration-sensing device, so that a vibration-sensing section made of a piezoelectric thin film is newly provided. It is not necessary and can be constructed at low cost. Further, in the present embodiment, the superimposed pressure fluctuation component from the seismic sensing unit 70 and the fluctuation component of the pipe pressure are input to the microprocessor 83 without separation, and the microprocessor 83 separates both signal components. Since the number of input / output ports required for this signal processing is one, the structure can be simpler and less expensive.

On the other hand, as shown in FIG. 5, for example, at the stage of an analog signal, a low pass filter (LPF) 85 and a high pass filter (HPF) 86 separate them from each other, and each is separated into an input / output port 87, It is also possible to configure to input to the microprocessor 83 via 88. In this case, the processing load on the microprocessor can be reduced.

[0031]

As described above, according to the vibration-sensing device of the first aspect, the internal pressure of the air chamber is changed according to the swing of the rocking body which is rocked by the earthquake vibration, and this pressure fluctuation is Since the earthquake is detected by detecting it, not only the presence or absence of an earthquake but also the magnitude of the shaking can be detected. In addition, since a mechanical electric switch mechanism as in the past is not necessary, it prevents the deterioration of reliability due to aging,
There is an effect that the life of the device can be extended.

According to the seismic sensing device of the second aspect, the gas pressure sensor provided in association with the gas meter is used (shared) to detect the pressure fluctuation, and the vibration component due to the earthquake is detected from the detected pressure fluctuation. Since the seismic component is separated and the seismic component is detected based on the seismic component, it is not necessary to newly install a pressure sensor, and the cost can be reduced.

According to the seismic sensing apparatus of the third aspect, the processing for separating the vibration component from the detected pressure fluctuation is performed by the microcomputer, so that the input / output ports of the microcomputer can be reduced and the low Effective in reducing costs.

According to the vibration-sensing device of the fourth aspect, since the process of separating the vibration component from the detected pressure fluctuation is performed by the frequency band filter, the processing load on the microcomputer can be reduced. There is.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main configuration of a seismic sensing device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an output waveform from a seismic sensing unit in FIG.

FIG. 3 is a cross-sectional view showing a main part configuration of a seismic sensing device according to another embodiment of the present invention.

FIG. 4 is a diagram illustrating an example of an output waveform from the seismic sensing unit in FIG.

FIG. 5 is a block diagram illustrating another example of a signal processing unit.

[Explanation of symbols]

 10, 70 Earthquake-sensing part 15 Sphere 17 Oscillator 30 Pressure fluctuation sensor part 32, 33 Air chamber 34, 64 Piezoelectric thin film 40, 80 Signal processing part 53 Gas meter main part 50 Gas meter 60 Pressure sensor part

Continued Front Page (72) Inventor Shinichi Sato 543-15 Kitano-cho, Hachioji-shi, Tokyo

Claims (4)

[Claims] 1. An oscillating body which oscillates due to an earthquake vibration, an air chamber whose internal pressure fluctuates in response to the oscillating body of the oscillating body, and a pressure detecting means which detects a pressure fluctuation in the air chamber. An earthquake-sensing device, comprising: an earthquake detection unit that detects an earthquake based on the pressure fluctuation detected by the pressure detection unit. 2. The pressure detecting means is commonly used as a gas pressure sensor provided in association with a gas meter, and further, a separating means for separating a vibration component due to an earthquake from the pressure fluctuation detected by the pressure detecting means. The seismic sensing device according to claim 1, wherein the seismic detection means performs seismic detection based on the separated seismic component. 3. The seismic sensing device according to claim 2, wherein the separating means is composed of a microcomputer. 4. The seismic sensor according to claim 2, wherein the separating means is constituted by a frequency band pass filter.