JPH112562A - Seismoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb impact force when a ball of a vibrator collides with an electrode to prevent interruption of a generated signal and generate a correct signal by making the viscosity of a filling liquid lower so that a switch part subjected to vibration is oscillated in a housing. SOLUTION: This selsmoscope is filled with a liquid having a low viscosity, for example, silicon oil with 100-200 cSt so that a switch part suspended in a housing 7 is vibrated to oscillate and displace. When high acceleration is applied to the seismoscope, a ball 4 of a vibration sensing element runs up along the slant face of a pot 1 bottom toward an electrode 5. As the viscosity of the liquid filled in the housing 7 is low, however, the switch part is also oscillated and displaced in the same direction as the received acceleration. Accordingly, the relative velocity of the moving ball 4 and the electrode 5 becomes low, so that the impact force of the ball 4 given to the electrode 5 is absorbed. Thus, even if high acceleration is applied, the electrode 5 keeps in contact with the ball 4 so as to prevent interruption of a generated signal and generate a correct signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic sensor which is a seismic detector which is attached to a gas meter or the like having a built-in gas shut-off device for preventing a gas accident and detects vibrations caused by an earthquake.

[0002]

2. Description of the Related Art Various types of safety devices have been used in the past to prevent highly dangerous gas accidents. Above all, built-in gas shut-off devices that detect abnormal gas use and gas leaks and shut off the gas. Gas meters are becoming more popular.

In particular, a gas meter which incorporates a battery power source, a microcomputer, and an electromagnetic shutoff valve, judges the gas usage state by the microcomputer, and shuts off the gas with the shutoff valve when there is an abnormality (hereinafter referred to as a microcomputer meter) is safe. Because of its superiority, economy, and ease of installation on gas pipes, efforts have been made to spread it to all households.

On the other hand, in Japan, where there are many earthquakes, in order to prevent gas accidents caused by earthquakes, there is an earthquake detection device that incorporates a seismic sensor in the microcomputer meter and closes a shut-off valve when an earthquake is detected. Invented and put to practical use.

A conventional embodiment will be described below with reference to the accompanying drawings. FIG. 5 shows the structure and operation of one embodiment of a conventional seismic sensor. The seismic sensor comprises a pot 1 having a constant bottom slope, a lid 2 closing an opening to form an airtight chamber with the pot 1, and a conductive pin 3 provided electrically insulated from the pot 1. A conductive ball 4 movably provided in the pot, an electrode 5 provided at the tip of the pin 3 so as to cover the ball 4, a contact between the ball 3 and the electrode 5 connected to the pin 3 and the pot 1; Signal lines 6A, 6 for outputting signals
And a housing 7 for suspending and storing the switch unit while always keeping the switch unit horizontal. In the housing 7, when the switch section receives vibration of a frequency of about 1 to 5 Hz or more, such as a seismic wave or a shock wave,
A high-viscosity liquid 8 that moves together with the liquid crystal is filled and covers the switch unit.

[0006] The contact diameter and the inclination angle of the seat at the center of the bottom surface of the pot 1 are adjusted so that the ball 4 starts to move when an acceleration exceeding a specified value is applied. When the seismic device is vibrated and an acceleration larger than a specified value is applied, the ball 4 starts to move from a seat at the center of the pot 1 and starts reciprocating vibration along the bottom surface of the pot 1. At this time, the ball 4 comes into contact with the electrode 5, the pot 1 and the electrode 5 are brought into conduction, an ON signal is generated between the terminals 9A and 9B, and sent to the signal processing unit 10. When the vibration stops, the ball 4 separates from the electrode 5 due to the gravitational force generated by the inclination of the slope of the pot 1 and returns to the center of the bottom of the pot 1 to turn off the signal.

If the acceleration applied to the seismic sensor is a repetitive vibration such as a seismic wave, the motion of the ball 4 also performs a vibrating motion in accordance with the frequency of the seismic wave and the magnitude of the acceleration.
The ball 4 repeatedly contacts and separates from the electrode 5, and if the vibration cycle or acceleration is large, the duration is long and if it is short, the ON is short.
A signal is output between terminals 9A and 9B in response to the vibration of the earthquake. The ON / OFF signal is input to the signal processing unit 10 and it is determined whether or not it is an "earthquake".

By converting the mechanical movement of the ball 4 into an electrical ON / OFF signal in this manner, the seismic sensor has an ON / OFF signal having a period, duration, and interval time corresponding to the frequency and magnitude of the acceleration of the seismic wave. An OFF signal will be generated.

FIG. 6 is a schematic diagram showing conditions for establishing a seismic signal. The horizontal axis indicates time, and the vertical axis indicates signal ON / OFF. The duration of the ON signal and the duration of the OFF signal are repeatedly measured, and the number M of valid signals that satisfies the conditions of the specified continuous ON time L1 and the specified OFF time L2 is counted. This shows that the signal processing unit 10 emits a seismic signal when the number of valid signals reaches a predetermined number M0 within a predetermined time from the generation of the ON signal.

The current seismic sensor is about 80 to 250 gal when expressed as a seismic intensity 5 and a peak acceleration value at a seismic intensity floor in Japan.
It has been adjusted to operate and emit a signal from a "strong earthquake", which is considered dangerous. In addition, the specified values used in the actual conventional earthquake determination logic are generally about 1 to 5 Hz, and seismic waves that are low-frequency vibrations are captured. Therefore, the continuous ON time L1 is about 30 to 50 msec, and the interval OFF time L3 is about 30. From 5
0 msec, the prescribed effective signal number M0 is 3 to 5 pulses, and the prescribed effective time is usually about 1 to 3 sec in consideration of the duration of the earthquake.

Next, the operation of the seismic sensor built in the microcomputer meter having the microcomputer gas shut-off device will be described.

FIG. 7 shows an example of a correlation between an acceleration waveform applied to the seismic sensor when an earthquake occurs and an output signal sent from the seismic sensor to the signal processing unit 10. The horizontal axis represents time, and the vertical axis represents the acceleration applied to the seismic device 1 and the signals sent from the seismic device to the signal processing unit 10 by ON / OFF.

In general, the frequency of the acceleration of vibration due to an earthquake is a low frequency, and the acceleration of a frequency between about 1 and 5 Hz is dominant. At this time, the seismic sensor follows the acceleration cycle of the seismic wave as shown in FIG. Output at a low cycle. This signal output is input to the signal processing unit 10 in FIG. 5 described above, and it is determined whether or not an “earthquake” occurs according to the determination logic described above. When the magnitude of the acceleration is sufficiently large, the ON time is also long, and the predetermined continuous ON time L1 and the specified OFF
Since many valid signals satisfying the condition of the time L2 are generated,
The signal processing unit 10 determines this vibration as “earthquake”. When the signal processing unit 10 determines that the event is an "earthquake", it outputs a specific output signal, for example, a signal for closing a gas shutoff valve.

[0014]

In recent years, as a large-scale earthquake such as the Great Hanshin-Awaji Earthquake has occurred, public awareness of disaster prevention has increased, and the spread of microcomputer meters equipped with seismic sensors has been further promoted in all areas. Various problems related to the operation of the seismic sensor have occurred. As one of the problems, there is a problem that a micro-earthquake activates the seismic sensor and activates a gas shut-off valve built into the microcomputer meter, causing unnecessary supply stoppage of gas in a wide area where the earthquake occurred. . As described above, the seismic sensor built into the microcomputer meter has a seismic intensity of 5 and a peak acceleration value of about 80 at the Japanese seismic intensity floor.
It is tuned to operate and emit a signal from a 250 gal "strong earthquake". However, despite the provision that the installation of the microcomputer meter that affects the operation of the seismic sensor is to be securely fixed to the rigid wall or the ground, there are construction examples that make extremely uncertain fixing in the market This is the actual situation. The actual earthquake that occurred was a "weak earthquake" with a seismic intensity of 3.
Even if the earthquake is relatively small, such as a "medium quake" with a seismic intensity of 4, or even when a large vehicle passes by or when a light shock is accidentally applied to the gas meter, the vibration is unstable due to unstable fixing. Amplified, the seismic sensor itself has a large amplitude and malfunctions, and the gas shut-off valve built in the microcomputer meter operates to stop gas supply. Such unnecessary stoppage of gas supply significantly impairs the convenience of gas users, and is a serious problem.

Therefore, based on the past experience with such microcomputer meters, the sensitivity of the seismic sensor was set to a level higher than the current seismic intensity 5 (approximately 180 to 250 gal). There is an attempt to lower to operation from 250 gal). However, the conventional configuration has the following problems to lower the operation sensitivity.

In the seismic sensor having the conventional configuration shown in FIG.
The adjustment of the operation sensitivity is performed by the contact diameter and the inclination angle of the seat at the center of the bottom surface of the pot 1 so that the ball 4 starts moving when an acceleration exceeding a specified value is applied. So in theory,
To lower the sensitivity of the seismic sensor, the diameter of the seat at the center of the pot 1 is increased to make it difficult for the ball 4 to start, and the inclination angle of the bottom surface of the pot 1 is increased. Then, when a larger acceleration is applied, the motor starts later and generates a signal. However, if the start of the ball 4 is slowed down and the ball 4 starts moving after the acceleration is increased, it becomes very difficult to balance the inertial force of the ball 4 with the braking force due to the component force of gravity formed by the slope of the pot 1. . In this case, the ball 4 runs up the inclination of the bottom surface of the pot 1, but the inertial force becomes larger than the braking force and collides with the electrode 5.
Cannot absorb the impact force received from the ball 4 and maintain the contact with the ball 4, so that the ball 4 is temporarily flipped and the contact is interrupted, resulting in a break in the signal generated from the seismic sensor.

FIG. 8 is a view for explaining the operation of the seismic sensor in which the shape of the pot is adjusted by the above-described method and the operation sensitivity is lowered using the main part, with the conventional configuration. Ball 4 with strong inertia
Shows a state in which the vehicle runs up on the slope of the bottom surface of the pot 1 while receiving the braking force, but collides with the electrode 5 and temporarily repels and separates.

FIG. 9 shows an acceleration waveform and an output signal of the earthquake when a strong seismic wave of seismic intensity 5 is applied to the seismic sensor. In the output signal, a break occurs in the signal because the ball 4 is temporarily repelled and separated from the electrode 5, and one long ON signal is supposed to be output, but becomes two short ON signals. Since the signal is not established, the microcomputer cannot determine that the vibration is an earthquake.

As described above, in the case of the seismic sensor in which the shape of the pot is adjusted and the operation sensitivity is lowered in the conventional configuration, the output signal is easily cut off, and the function of the microcomputer meter to detect the earthquake becomes unstable. There was a problem that.

In view of such a conventional problem, the present invention absorbs an impact force when a ball, which is a vibrator, collides with an electrode and turns ON the ball.
It is an object of the present invention to provide a seismic sensor that prevents an interruption of a signal and generates an accurate signal.

[0021]

In order to solve the above-mentioned problems, a seismic device according to the present invention comprises a pot having a sloped bottom surface,
A lid that forms a pot and an airtight chamber, a conductive pin provided on the lid and electrically insulated from the pot, a conductive ball that opens and closes contacts as a seismic element in the airtight chamber, An electrode provided at the tip of the pin in the chamber, and a switch unit including a signal line for outputting a contact signal between the ball and the electrode,
A housing is provided for suspending and storing the liquid-filled switch section, and the viscosity of the filled liquid is reduced until the switch section swings with respect to the housing when subjected to vibration.

According to the present invention, the shock force generated when the ball as the vibrator collides with the electrode is absorbed to prevent the signal generated in the ON signal from being cut off, and an accurate signal is generated even if the operation sensitivity is lowered. A vessel is obtained.

[0023]

DETAILED DESCRIPTION OF THE INVENTION A seismic sensor according to claim 1 of the present invention comprises a conductive pot having a sloped bottom surface surrounded by a cylindrical body and having an open upper portion, and a pot having a closed upper opening. A lid forming an airtight chamber, a conductive pin provided on the lid electrically insulated from the pot, a conductive ball movably provided in the airtight chamber, and An electrode provided at the tip of the facing pin so as to cover the hard sphere, a switch unit including a signal line connected to the pin and the pot and outputting a contact signal between the hard sphere and the electrode, and the switch unit. A suspending mechanism for lowering, a housing for suspending and storing the switch unit, and a liquid filled in the housing so as to cover the switch unit. Before Because it is characterized by swinging with respect to the housing, even when the seismic sensor receives large acceleration and the ball, which is a seismic element, starts up and runs up the slope of the pot and hits the electrode, it is filled. The suspended switch part swings and moves in the same direction as the ball due to the low viscosity of the liquid, which absorbs the impact force when the ball collides with the electrode, equivalently, the repulsive force of the electrode bouncing off the ball. It is possible to prevent an ON signal from being cut off and generate an accurate signal.

Further, the seismic sensor according to claim 2 of the present invention uses a silicone oil having a viscosity of about 100 to 200 CSt as a liquid to be filled. Due to the low viscosity, an impact force / repulsion when a ball collides with an electrode is used. In addition to absorbing forces, there is no volatilization of the liquid itself and it is nonflammable and does not require a high hermeticity of the housing.

Further, in the vibration sensor according to the third aspect of the present invention, since the housing is completely sealed by welding the cylindrical body and the lid of the metal case, the liquid to be charged is prevented from evaporating and the viscosity is high, and the viscosity is high. Liquid can be used, and the suspended switch portion swings and moves more, so that the impact force when the ball collides with the electrode can be absorbed more.

In the seismic sensor according to the fourth aspect of the present invention, since the electrodes provided in the airtight chamber are made to have elasticity, the impact force generated when the ball collides with the electrodes is absorbed and an ON signal is generated. Prevents a signal from being cut off and generates a signal without a break.

In the seismic sensor according to the fifth aspect of the present invention, since the shape of the electrode provided in the airtight chamber is bent at the same curvature as that of the hard sphere, the contact portion of the ball with the electrode becomes a line from a point. Since the contact area is increased, the contact is ensured, the signal generated in the ON signal is prevented from being cut, and a signal without cut is generated.

[0028] The seismic sensor according to claim 6 of the present invention uses a high specific gravity lead for the hard sphere enclosed in the airtight chamber, and is used when the mass of the ball as the vibrator is greatly accelerated. The inertia force is increased, and even if the electrode comes into collision with the electrode, the electrode is less likely to be repelled or separated due to the elasticity of the electrode, thereby preventing the signal from being cut off.

An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a cross-sectional view showing a state in which acceleration is applied to a seismic sensor according to Embodiment 1 of the present invention and contacts are closed.

The basic configuration is the same as that of the conventional example shown in FIG.
Since the principle of conversion to the OFF signal is the same as that of the related art, parts different from the related art will be described.

The fundamental difference from the conventional seismic sensor is that in the conventional seismic device shown in FIG. 5, the switch section receives acceleration of a frequency of about 1 to 5 Hz or more, which is the dominant vibration of the seismic wave. Even though the liquid having a high viscosity is filled so as to move integrally with the housing 7, in the present embodiment, if the same vibration is received, the switch suspended from the housing 7 swings and displaces. Is filled with a low viscosity liquid. Specifically, in the conventional example, a liquid of about 6000 CSt is filled, but in the present embodiment, a silicone oil having a viscosity of about 100 to 200 CSt is filled.

Next, the operation will be described. When a strong acceleration is applied to the vibrator, the ball 4 as a vibrator moves up the slope of the bottom surface of the pot 1 toward the electrode 5.
Since the viscosity of the liquid filled in the housing 7 is small, the switch suspended from the housing 7 also swings and displaces in the same direction as the received acceleration. Therefore, the relative speed between the moving ball 4 and the electrode 5 is reduced, and the ball 4 absorbs the impact force applied to the electrode 5 and the repulsive force returned from the electrode 5 to the ball 4 as a reaction.
Therefore, even if a large acceleration is received, the electrode 5 can maintain contact with the ball 4, preventing the generated signal from being cut off and generating an accurate signal.

FIG. 2 shows a seismic intensity of 5 according to the first embodiment of the present invention.
FIG. 7 is a diagram showing an applied acceleration and an output signal when a strong (peak acceleration value of about 250250 gal) seismic wave is applied. The horizontal axis represents time, and the vertical axis represents acceleration and signals transmitted from the seismic sensor as ON / OFF. This indicates that even if a strong earthquake or a large acceleration is applied, the signal is not cut off and an accurate signal is transmitted.

If a low-viscosity liquid is used so that the switch portion suspended from the housing 7 swings and displaces when subjected to vibration, the viscosity and the type of the liquid are not limited. 200CSt silicone oil is used. This is because this liquid is the lowest viscosity liquid that has the property of being chemically stable, non-volatile and not self-igniting.

When the housing 7 is a completely sealed container formed by welding a cylindrical body and a lid of a metal case, a liquid having a lower viscosity is filled.

(Embodiment 2) FIG. 3 is a cross-sectional view of a main part of a switch unit in a state where acceleration is applied to a seismic sensor according to Embodiment 2 of the present invention and contacts are closed.

In FIG. 3, the electrode 5 which was not deformed unless subjected to a strong shock exceeding 1 G in the conventional seismic sensor.
Has a further lower elasticity, and when the ball 4 collides with the electrode 5 when subjected to an acceleration (about 250 gal) of a seismic wave, the ball 4 is deformed until it hits the pot 1.

(Embodiment 3) FIG. 4 is a sectional view of a main part of a switch section of a seismic sensor according to Embodiment 3 of the present invention.

In FIG. 4, the tip of the electrode 5 is bent at the same curvature as the ball 4. The ball 4 of the seismic element uses lead having a large specific gravity.

[0040]

According to the present invention, the following effects can be obtained.

By filling a liquid having a low viscosity and swinging and displacing the switch section when an acceleration is applied, the impact force when the ball, which is a seismic element, collides with the electrode is absorbed. In order to prevent interruption of the signal to be transmitted, there is an advantageous effect that an accurate signal can be transmitted and the operation sensitivity of the seismic sensor can be reduced.

The liquid to be filled has a viscosity of about 100 to 20.
Because of the use of silicone oil of 0 CSt, the viscosity is low and the ability to absorb the impact force when the ball collides with the electrode is high, and it is chemically stable, nonvolatile and has a flash point of about 500.
It has the advantageous properties that it does not spontaneously ignite as high as over ℃ and is inexpensive.

Further, by adopting a structure in which the housing is a completely sealed container formed by welding a cylindrical body of a metal case and a lid, a liquid having a lower viscosity and having a higher volatility can be used. Since the impact force when the ball collides with the electrode can be more greatly absorbed, there is an advantageous effect that the operation sensitivity of the seismic sensor can be further reduced.

Further, the electrode is provided with a weak elasticity, and when the ball as a seismic element collides with the electrode, the electrode is deformed by a relatively small acceleration such as a seismic wave to absorb the impact force of the ball,
There is a similar effect of preventing interruption of a signal transmitted from the seismic sensor.

Further, since the tip of the electrode is bent at the same curvature as the ball, the same effect is obtained that the contact of the ball with the electrode is ensured and the signal transmitted from the seismic sensor is prevented from being interrupted.

Further, since the specific gravity of the ball is large, the mass of the ball is large, so that repulsion and separation from the electrode due to a reaction received when the ball collides with the electrode can be prevented. There is a similar effect of preventing interruption. Although lead is used as the material, similar effects can be obtained by using a metal having a higher specific gravity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which acceleration is applied to a seismic sensor according to Embodiment 1 of the present invention and contacts are closed.

FIG. 2 is a diagram showing acceleration and output signals applied when a strong seismic wave of seismic intensity 5 is applied to the seismic sensor.

FIG. 3 is a cross-sectional view of a main part of a switch unit in a state where acceleration is applied to a seismic sensor according to a second embodiment of the present invention and a contact is closed.

FIG. 4 is a sectional view of a main part of a switch unit of a seismic sensor according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a conventional seismic sensor.

FIG. 6 is a schematic diagram showing conditions for establishing a seismic signal.

FIG. 7 is a diagram showing a correlation between an acceleration waveform applied to a seismic sensor and a signal output from the seismic device when an earthquake occurs.

FIG. 8 is a cross-sectional view illustrating the operation when the operation sensitivity of the conventional seismic sensor is reduced.

FIG. 9 is a diagram showing an acceleration waveform and an output signal of an earthquake when a strong seismic wave having a seismic intensity of 5 is applied to lower the operation sensitivity of the seismic sensor.

[Explanation of symbols]

 Reference Signs List 1 pot 2 lid 3 pin 4 ball 5 electrode 6A signal line A 6B signal line B 7 housing 8 liquid 9A terminal A 9B terminal B 10 signal processing unit

Claims (6)

[Claims] A conductive pot having an upper portion opened by enclosing a periphery of a sloped bottom surface with a cylindrical body, a lid closing the opening to form a pot and an airtight chamber, and electrically connecting the pot to the pot. Insulated conductive pins provided on the lid, conductive balls movably provided in the hermetic chamber, and tips of the pins facing the hermetic chamber were provided to cover the balls. An electrode, a switch connected to the pin and the pot and outputting a contact signal between the ball and the electrode, a suspension mechanism for suspending the switch, a housing for suspending and housing the switch, and the switch. And a liquid filled in the housing, wherein the switch unit swings with respect to the housing when subjected to vibration. 2. The liquid to be filled has a viscosity of about 100 to 200.
The seismic sensor according to claim 1, wherein CSt silicone oil is used. 3. The seismic sensor according to claim 1, wherein the housing is completely sealed by welding the cylindrical body and the lid of the metal case. 4. The seismic sensor according to claim 1, wherein the electrodes provided in the airtight chamber have elasticity. 5. The vibration sensor according to claim 1, wherein the shape of the electrode provided in the airtight chamber is bent at the same curvature as the ball. 6. The seismic sensor according to claim 1, wherein a lead ball is used as the ball sealed in the airtight room.