WO2012117589A1

WO2012117589A1 - Seismoscope

Info

Publication number: WO2012117589A1
Application number: PCT/JP2011/069683
Authority: WO
Inventors: 文雄西野; 正之木下
Original assignee: 立山科学工業株式会社
Priority date: 2011-03-03
Filing date: 2011-08-31
Publication date: 2012-09-07

Abstract

This seismoscope is provided with: a spherical vessel; a fluid that fills the vessel leaving an air space at a portion of the vessel; and a highly sensitive temperature-sensing element or a highly sensitive pressure-sensing element disposed within the vessel in the state of being immersed in the fluid. The seismoscope is characterized by detecting the fluctuations in temperature or pressure resulting from the flow of the fluid when shaking is applied. The highly sensitive temperature-sensing element or the highly sensitive pressure-sensing element is disposed in the vicinity of the center of the spherical vessel. The fluid has a low vapor pressure. A circuit is provided that recognizes temperature fluctuations of the highly sensitive temperature-sensing element or fluctuations in pressure applied to the highly sensitive pressure-sensing element.

Description

Seismograph

[Technical Field] The present invention relates to a seismic device that detects vibration during an earthquake such as an earthquake.

As this type of seismic device, a mechanical type seismic device or an acceleration sensor type seismic device is known (for example, Patent Document 1 and Patent Document 2).

FIG. 3 is a diagram schematically showing a conventional mechanical seismic device, where (a) is a diagram showing a steady state, and (b) is a diagram showing a state during vibration. As shown in FIG. 3, the mechanical seismic device 100 is configured to open and close an electrical contact 101 with a steel ball 102. In a steady state, the electrical contact 101 is closed as shown in FIG. 3A, and during the vibration, the electrical contact is caused by the movement of the steel ball 102 as shown in FIG. 3B. 101 is configured to be opened.

Fig. 4 is a block diagram of an accelerometer of the acceleration sensor type. As shown in FIG. 4, the acceleration sensor type seismic device 200 includes an acceleration sensor 201 and a sensor driver / microcomputer 202, and as shown in FIG. It is configured to measure and output in series. FIG. 5 is a diagram showing time series data of acceleration when the vertical axis is output and the horizontal axis is time, (a) is a diagram showing steady-state data, and (b) is an additional graph. It is a figure which shows the data at the time of an earthquake.

Japanese Patent Laid-Open No. 9-72778 Japanese Patent Laid-Open No. 11-173447

The mechanical seismic device 100 has a simple structure, can be easily reduced in price, and does not require standby power because of mechanical operation. However, since the horizontal dependency at the time of installation is very large, it becomes impossible to operate depending on the level of installation, and since it is a mechanical contact, there is a problem that the number of operations is limited.

On the other hand, the acceleration sensor type seismic device 200 does not need to consider the horizontal dependency at the time of installation, and the magnitude of the vibration itself can be known in time series, and an ultrasensitive product can be easily made. it can. However, it is generally expensive and often overspec (excess performance). In addition, complicated signal processing is required, and accordingly, standby power is consumed by a driver and a microcomputer, resulting in a problem of increased power consumption.

In view of these problems, the present invention has little dependency on horizontality, the number of operations is semi-permanent, is not over-spec, does not require complicated signal processing, is inexpensive, and has low power consumption. The issue is to provide a seismic device.

As a result of intensive studies, the present inventor has found that the above-described problems can be solved by the invention shown below, and has completed the present invention.

Hereinafter, the invention of each claim will be described.

The invention described in claim 1
A spherical container;
A liquid filled in the container leaving an air space in a part of the container;
A high-sensitivity thermosensitive element disposed in the container in a state immersed in the liquid,
By self-heating by the measurement current of the high-sensitivity thermosensitive element, the liquid is heated to form a high-temperature region around the high-sensitivity thermosensitive element,
It is a seismometer that detects a decrease in temperature around the high-sensitivity thermosensitive element due to the flow of the liquid during vibration.

The invention described in claim 2
The seismic sensor according to claim 1, wherein the high-sensitivity temperature sensing element is disposed in the vicinity of a spherical center of the spherical container.

The invention according to claim 3
The seismic device according to

claim

1 or 2, wherein the liquid is a liquid having a low vapor pressure.

The invention according to claim 4
The seismic device according to any one of claims 1 to 3, further comprising a circuit that recognizes a temperature change of the high-sensitivity thermosensitive element.

The invention described in claim 5
A spherical container;
A liquid filled in the container leaving an air space in a part of the container;
A high-sensitivity pressure-sensitive element disposed in the container in a state immersed in the liquid,
It is a seismic device that detects a change in pressure applied to the high-sensitivity pressure-sensitive element due to the flow of the liquid during vibration.

The invention described in claim 6
The seismic sensor according to claim 5, wherein the high-sensitivity pressure-sensitive element is disposed in the vicinity of a spherical center of the spherical container.

The invention described in claim 7
The seismic device according to

claim

5 or 6, wherein the liquid is a liquid having a low vapor pressure.

The invention according to claim 8 provides:
8. The seismic sensor according to claim 5, further comprising a circuit for recognizing a change in pressure applied to the high-sensitivity pressure-sensitive element.

According to the present invention, it is possible to provide a seismic instrument that is less dependent on level, has a semi-permanent operation, does not become over-spec, does not require complicated signal processing, is inexpensive, and consumes less power. Can be offered.

It is a figure which shows typically the seismic device which concerns on the 1st Embodiment of this invention. It is a figure which shows typically the seismic device which concerns on the 2nd Embodiment of this invention. It is the figure which showed the mechanical type seismic device typically, Comprising: (a) is a figure which shows the state at the time of a steady state, (b) is a figure which shows the state at the time of an earthquake. It is a block diagram of an accelerometer of an acceleration sensor type. It is a figure which shows the time series data of the acceleration when taking an output on a vertical axis | shaft and taking time on a horizontal axis, (a) is a figure which shows the data at the time of steady, (b) shows the data at the time of an earthquake. FIG.

Hereinafter, the present invention will be described based on embodiments.

(A) First Embodiment FIG. 1 is a diagram schematically showing a seismic device according to the first embodiment of the present invention. As shown in FIG. 1, the seismic device 1 includes a spherical container 2, a liquid 3 filled in the container 2, a thermistor 5 that is a kind of a high-sensitivity thermosensitive element immersed in the liquid 3, A circuit unit 8 having a differentiating circuit, an amplifier circuit, and a temperature compensation circuit, and an informing means (not shown) for informing vibration by a detection signal of the thermistor 5 are provided. As the high-sensitivity thermosensitive element, it is also preferable to use a high-precision platinum resistance thermometer, a thermocouple, etc. in addition to the thermistor.

Container 2 is an empty sphere. The material is preferably stainless steel, resin, glass or the like, but is not particularly limited as long as the liquid can be stably held.

As the liquid 3, a liquid having a low vapor pressure such as silicone oil is used.

An air space portion 4 is formed above the liquid 3 in the container 2 so that the liquid 3 has fluidity when the container 2 is vibrated.

The thermistor 5 is disposed in the center of the container 2 in a state where it is connected to the lead wire 5a of the thermistor 5. The lead wire 5 a is connected to the circuit unit 8 through the sealing unit 7 formed in the upper part of the container 2. 2a is a through hole.

A flow stopper 6 is disposed around the lead wire 5a. The flow stopper 6 is formed of a hollow tube having a predetermined strength, the lead wire 5 a is inserted inside, and is fixed to the container 2 by the sealing portion 7. The sealing part 7 is sealed using a material corresponding to the material of the spherical container. For example, if the container is made of resin or stainless steel, resin sealing or the like is used. If the container is made of glass, glass sealing or the like is used.

The flow stop 6 prevents the position of the thermistor 5 from moving due to the fluid pressure of the liquid 3 even when the container 2 shakes during the vibration. When the lead wire 5a having strength is used, the flow stopper 6 is not necessary.

2. Operation of the seismic device The basic operation of the seismic device 1 configured as described above will be described.

The thermistor 5 is made to be able to recognize the temperature difference between the steady state and the shaking state by constantly passing a measurement current.

For this reason, the thermistor 5 causes self-heating due to the measurement current and heats the liquid 3 around the thermistor 5.

Therefore, in a steady state, a high temperature region (in the region indicated by a one-dot chain line in FIG. 1) is formed around the thermistor 5, and the thermistor 5 detects the high temperature.

On the other hand, at the time of vibration, since the liquid 3 flows due to the vibration of the container 2, the liquid 3 in the high temperature region and the liquid 3 in the low temperature region around it are mixed. For this reason, the temperature of the liquid 3 in the high temperature region around the thermistor 5 decreases. Then, the temperature change amount of the thermistor 5 during the steady state and during the shaking is detected by the differentiation circuit, amplified by the amplification circuit, and then the error of the temperature change is corrected by the temperature compensation circuit, and the difference from the steady state temperature is accurately measured. Recognize it high and notify the supervisor through the notification means as appropriate.

3. Advantages of the present embodiment (1) In the present embodiment, a highly sensitive temperature sensitive element such as a thermistor is immersed in a liquid in a spherical container provided with an air space at the upper part, and the flow of the liquid A method using the temperature change of the high-sensitivity thermosensitive element is adopted. And even if a seismoscope shakes at the time of an earthquake, the air space part is always above and the highly sensitive temperature sensing element is always immersed in the liquid.

Therefore, accurate detection is always possible without being affected by the direction of shaking caused by an earthquake. That is, in the case of a conventional mechanical type seismic device, even if it is installed horizontally, the detection result tends to differ between the case where the direction of shaking is up and down and the case where it is left and right. In addition, in the case of an acceleration sensor type seismic device, the horizontal dependency at the time of installation does not need to be taken into consideration relatively, but the detection result tends to differ between when the shaking direction is up and down and when it is left and right. However, in the present embodiment, since a method using the temperature change of the high-sensitivity thermosensitive element due to the flow of the liquid is employed, accurate detection is always possible without being affected by the direction of shaking.

Furthermore, since the container is spherical, accurate detection is possible regardless of the installation direction. In particular, when the high-sensitivity thermosensitive element is disposed in the vicinity of the sphere center of a spherical container, the direction dependency with respect to the shaking direction is completely eliminated, so that extremely accurate detection is possible.

As described above, the seismic device according to the present embodiment has not only the horizontal dependency of the installation but also the direction dependency with respect to the shaking direction, so that extremely accurate detection is possible.

(2) Since it is only necessary to recognize the temperature change during steady state and during shaking, the signal from the high-sensitivity thermosensitive element only needs to be processed by a simple circuit such as a differentiation circuit, amplification circuit, and temperature compensation circuit. Since the power consumption is low and the operation can be performed at 100 μW or less, the battery can be operated for a long time.

(3) Since the liquid is heated by self-heating by the measurement current of the high-sensitivity thermosensitive element, it is not necessary to provide a separate heating means, the structure is simple, and the power consumption is small.

(4) While eliminating the mechanical contact, it is a simple method of detecting a decrease in temperature at the time of vibration by a highly sensitive thermosensitive element immersed in the liquid in the container, so that the number of operations becomes semi-permanent.

(5) As described above, the liquid heating method by self-heating using the measurement current of the high-sensitivity thermosensitive element is adopted, and the structure is simple such that the high-sensitivity thermosensitive element is simply immersed in the liquid. However, since a simple circuit is sufficient, the cost is low, and only a change in temperature during steady state and during shaking is detected, so that complicated signal processing as in the acceleration sensor type is not required.

(B) Second Embodiment 1. FIG. FIG. 2 is a diagram schematically showing a seismic device according to the second embodiment of the present invention. As shown in FIG. 2, the seismic device 1 includes a spherical container 2, a liquid 3 filled in the container 2, and a piezoelectric element 5 ′ which is a kind of high-sensitivity pressure-sensitive element immersed in the liquid 3. A circuit unit 8 having a differentiating circuit, an amplifying circuit, and a temperature compensation circuit, and a notifying means (not shown) for notifying vibration by a detection signal of the piezoelectric element 5 ′.

The piezoelectric element 5 ′ is arranged at the center of the container 2 in a state of being connected to the lead wire 5 a of the piezoelectric element 5 ′. The lead wire 5 a is connected to the circuit unit 8 through the sealing unit 7 formed in the upper part of the container 2. 2a is a through hole.

The flow stop 6 prevents the position of the piezoelectric element 5 ′ from moving due to the fluid pressure of the liquid 3 even when the container 2 is shaken during the vibration. When the lead wire 5a having strength is used, the flow stopper 6 is not necessary.

A constant pressure corresponding to the liquid depth is constantly applied to the piezoelectric element 5 ′.

At the time of vibration, since the liquid 3 flows due to the vibration of the container 2, a flow resistance is generated with respect to the piezoelectric element 5 '. This flow resistance generates a slight pressure difference, and a slight pressure difference is applied to the piezoelectric element to which a constant pressure is continuously applied according to the liquid depth described above, resulting in a change in pressure. This change in pressure can be taken out as a displacement signal from the piezoelectric element.

Then, after detecting the amount of change in pressure with a differential circuit and amplifying it with an amplifier circuit, the piezoelectric element 5 ′ is further temperature-dependent, so the temperature compensation circuit corrects the temperature change error, and the pressure change is corrected. Recognize with high accuracy, and notify the supervisor appropriately through the notification means.

As the high-sensitivity pressure-sensitive element, a piezoelectric element can be preferably used as described above. However, the piezoelectric element is not limited to the piezoelectric element, and a quartz vibrator whose resonance frequency changes with pressure can also be preferably used.

When a crystal resonator is used, a current for vibrating the crystal resonator is allowed to flow, and the resonance frequency of the crystal resonator is detected. At the time of vibration, since the pressure due to the vibration is applied to the quartz vibrator by the flow of the liquid 3, the resonance frequency changes according to the distortion of the quartz. For this reason, it can recognize that it was shaken by detecting this variation | change_quantity in the circuit part 8. FIG. Also in this case, the pressure change amount is detected by the differentiation circuit, amplified by the amplification circuit, and the temperature change error is corrected by the temperature compensation circuit in the same manner as the piezoelectric element, so that the pressure change can be recognized with high accuracy. Can do.

3. Effects of this embodiment (1) In this embodiment, a highly sensitive pressure sensitive element such as a piezoelectric element is immersed in a liquid in a spherical container provided with an air space at the top, and the liquid A method that utilizes a pressure change of a high-sensitivity pressure-sensitive element due to flow is employed. And even if a shaker shakes at the time of an earthquake, the air space part is always above and the highly sensitive pressure sensitive element is always immersed in the liquid.

Therefore, accurate detection is always possible without being affected by the direction of shaking caused by an earthquake or the like. That is, in the case of a conventional mechanical type seismic device, even if it is installed horizontally, the detection result tends to differ between the case where the direction of shaking is up and down and the case where it is left and right. In addition, in the case of an acceleration sensor type seismic device, the horizontal dependency at the time of installation does not need to be taken into consideration relatively, but the detection result tends to differ between when the shaking direction is up and down and when it is left and right. However, in the present embodiment, since a method using the pressure change of the high-sensitivity pressure-sensitive element due to the flow of liquid is adopted, accurate detection is always possible without being affected by the direction of shaking.

Furthermore, since the container is spherical, accurate detection is possible regardless of the installation direction. In particular, when the high-sensitivity pressure-sensitive element is disposed in the vicinity of the spherical center of the spherical container, the direction dependency with respect to the shaking direction is completely eliminated, so that extremely accurate detection is possible.

(2) Since it is only necessary to recognize the pressure change during steady state and shaking, the signal from the high-sensitivity pressure-sensitive element need only be processed by a simple circuit such as a differentiation circuit, amplification circuit, and temperature compensation circuit. Since the power consumption is low and the operation can be performed at 100 μW or less, the battery can be operated for a long time.

(3) While the mechanical contact is eliminated, the number of operations is semi-permanent because it is a simple method of detecting a pressure change at the time of vibration by a highly sensitive pressure sensitive element immersed in the liquid in the container.

(4) As mentioned above, it has a simple structure in which a high-sensitivity pressure-sensitive element is simply immersed in a liquid, and the processing circuit can be a simple circuit, so it is inexpensive and can detect pressure changes during steady-state and vibration. Therefore, complicated signal processing as in the acceleration sensor type is not required.

As described above, according to the embodiment of the present invention, the container is filled with the liquid in a state where an air space is left in a part of the container, and the earthquake disposed in the container in a state immersed in the liquid. And an element for detecting a change in the state of the liquid in the container due to the shaking due to the above, and therefore, it is possible to perform extremely accurate detection without being affected by the direction of shaking due to an earthquake or the like.

As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to said embodiment. Various modifications can be made to the above-described embodiments within the same and equivalent scope as the present invention.

DESCRIPTION OF SYMBOLS 1 Seismic device 2 Container 2a Through-hole 3 Liquid 4 Air space part 5 Thermistor 5 'Piezoelectric element 5a Lead wire 6 Flow stop 7 Sealing part 8 Circuit part 100 Mechanical type seismic device 101 Electric contact 102 Steel ball 200 Acceleration sensor Type seismic sensor 201 Acceleration sensor 202 Sensor driver / microcomputer

Claims

A spherical container;
A liquid filled in the container leaving an air space in a part of the container;
A high-sensitivity thermosensitive element disposed in the container in a state immersed in the liquid,
By self-heating by the measurement current of the high-sensitivity thermosensitive element, the liquid is heated to form a high-temperature region around the high-sensitivity thermosensitive element,
A seismometer that detects a decrease in temperature around the high-sensitivity thermosensitive element due to the flow of the liquid during vibration.
The seismic device according to claim 1, wherein the high-sensitivity temperature sensing element is disposed in the vicinity of a spherical center of the spherical container.
The seismic device according to claim 1, wherein the liquid is a liquid having a low vapor pressure.
The seismic sensor according to any one of claims 1 to 3, further comprising a circuit for recognizing a temperature change of the high-sensitivity thermosensitive element.
A spherical container;
A liquid filled in the container leaving an air space in a part of the container;
A high-sensitivity pressure-sensitive element disposed in the container in a state immersed in the liquid,
A seismometer that detects a change in pressure applied to the high-sensitivity pressure-sensitive element by the flow of the liquid during vibration.
The seismic sensor according to claim 5, wherein the high-sensitivity pressure-sensitive element is disposed in the vicinity of a spherical center of the spherical container.
The seismic device according to claim 5 or 6, wherein the liquid is a liquid having a low vapor pressure.
The seismometer according to any one of claims 5 to 7, further comprising a circuit for recognizing a change in pressure applied to the high-sensitivity pressure-sensitive element.