JP2911248B2 - Vibration velocity detection type earthquake sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit for, for example, a safety device, an alarm device, etc., when a magnitude of a shaking is detected at the time of the occurrence of an earthquake. To operate the SI (Spectrum Int)
The present invention relates to a vibration speed detection type earthquake sensor including an intensity detection type.

[0002]

2. Description of the Related Art Conventionally, a steel ball 52 is placed on a pedestal 51 as shown in FIG. 3 for the purpose of preventing a fire or other secondary disaster induced in a city gas supply system or an oil plant when an earthquake occurs. A steel ball 52 is dropped when an acceleration of a certain level or more is detected to close the electrical contact 53 by a spring 54, or a pendulum supported by a spring material 56 as shown in FIG. 5
When the vibration of 7 causes the acceleration to exceed a certain level, the electric contact 5
An earthquake sensor configured to close 5 is known.

[0003] Each of the above-mentioned earthquake sensors is configured to sense the magnitude of an earthquake by acceleration. However, in the case of a city gas supply system or a building such as an oil plant or a skyscraper, damages due to the earthquake are generated. Is not necessarily proportional to the magnitude of the acceleration.

For this reason, the above-mentioned acceleration response type earthquake sensor may not be able to properly prevent disasters.

Therefore, what is proposed is the construction of disaster prevention measures using a so-called vibration speed detection type earthquake sensor for detecting the SI value, the maximum speed, and the like.

Conventionally, such a vibration velocity detecting type earthquake sensor collects an acceleration waveform based on the principle of electromagnetic induction, and calculates, for example, an SI value by an arithmetic circuit or a computer.

[0007]

However, in the case of the method of collecting the acceleration waveform based on the principle of electromagnetic induction as described above, if electromagnetic noise is generated near the sensor, malfunction may occur due to the noise. However, it is expensive due to the use of an electromagnetic coil.

The present invention has been proposed in view of the above, and an object of the present invention is to provide a vibration velocity detecting type earthquake sensor which can be manufactured at low cost without malfunction due to electromagnetic wave noise.

[0009]

The present invention achieves the above object.
To avoid over-braking,
The mechanism provides direct movement in all directions proportional to the vibration speed.
And a displacement of the pendulum.
Control signal when this displacement exceeds a certain value.
And a control circuit configured to output the vibration speed.
In the degree detection type earthquake sensor, the pendulum has a disk-shaped control
Attach the plate and shield the control plate from light
Or to form a plurality of light-shielding or light-transmitting portions having different light-transmitting areas,
Furthermore, the light-shielding or light-transmitting portions are opposed to each other with the light-shielding or light-transmitting portions being in the middle.
The light emitting element and the light receiving element of the control circuit are
By switching the signal from the light receiving element of
Control signal output from the control circuit.
It is characterized by having comprised in.

In the present invention, the shape of the control plate is not particularly limited to a circle or a polygon, but is preferably a perfect circle in consideration of a weight balance. Of course, a material that is not affected by a change in temperature is selected.

The positions of the light emitting element and the light receiving element are above and below the center of the slit when a slit is provided as a light shielding or light transmitting part in the control plate. In addition, by disposing the light emitting element and the light receiving element opposite to a position slightly apart from the periphery of the disc-shaped control plate instead of the slit,
The displacement of the control plate may be detected in the 360 ° direction. In this case, it is desirable in terms of accuracy that the arrangement positions are arranged at a minimum of three places, preferably at four or more places at equal intervals.

[0012]

When an earthquake occurs and this shaking (vibration) acts on the sensor, the pendulum including the control plate swings. When the light emitted from the light emitting element is blocked or transmitted by the control plate, a signal is generated in the light receiving element,
This signal activates, for example, a safety device.

In the case where the light emitting element always emits light, a battery type consumes a large amount of power. For example, in order to turn on and off a power switch of the battery, as shown in FIGS. Alternatively, the power switch may be set to the ON state only when an earthquake of a certain magnitude is detected in combination with an acceleration type earthquake sensor.

[0014]

1 schematically shows an earthquake sensor embodying the present invention. In this figure, reference numeral 1 denotes a pendulum shaft, which is supported on a support 12 at a fulcrum 2 by a gimbal mechanism.
It is swingable in the direction of 60 °.

At the lower end of the pendulum shaft 1, an overbraking mechanism is provided.
A brake board 7 made of an aluminum plate is horizontally fixed, and a portion around the brake board 7 is located between both magnetic poles of the permanent magnet 8 for braking. The brake plate 7 has, for example, a pendulum shaft 1
Is given a braking force calculated by a braking coefficient h = 3.

As shown in FIG. 2, a disk-shaped transparent control plate 6 provided with a circular slit 5 is horizontally fixed to the pendulum shaft 1. The control plate 6 is provided with a light-shielded slit 5.
The light receiving element 4 and the light emitting element 3 are disposed opposite to each other at the upper and lower positions of the center to detect the displacement (vibration) of the control plate 6, and the light from the light emitting element 3 is shielded at normal times by the slit 5. . The light receiving element 4 is connected to, for example, an amplifier 9 on the safety device side, and the amplifier 9 is connected to a relay contact 10 provided in a control circuit 11 of the safety device.

Here, when an earthquake occurs, the pendulum shaft 1 swings about the fulcrum 2 and the control plate 6 is displaced. When the slit 5 separates from the light emitting element 3 and the light receiving element 4 due to this displacement, light emitted from the light emitting element 3 passes through the control plate 6 and is input to the light receiving element 4. At this time, a signal is output from the light receiving element 4 and the signal is amplified by the amplifier 9 and enters the relay contact 10 to open or close the control circuit 11. Now, assuming that the ground motion is Y and the displacement value of the pendulum shaft 1 is X, the following relational expression 1 holds (where h: braking coefficient, ω ₀ : natural angular frequency of the pendulum).

[0018]

(Equation 1)

By adjusting the relationship between the braking board 7 and the permanent magnet 8, h
When the condition of = 3 is satisfied, Expression 1 is approximately expressed by Expressions 2 and 3 (where h: braking coefficient, ω ₀ : natural angular frequency of the pendulum).

[0020]

(Equation 2)

[0021]

(Equation 3)

From equation 3, the displacement X of the pendulum shaft 1 is approximately proportional to the differentiated value of the ground motion Y. From this, by adjusting the size of the slit 5, it is possible to detect an earthquake larger than the required size and open and close the control circuit 11.

[0023]

As described above, the earthquake sensor according to the present invention applies, for example, a braking coefficient h = 3 to the pendulum shaft, makes the displacement of the pendulum shaft approximately proportional to the speed of the earthquake, and makes this movement by light. By detecting, a light-emitting element and a light-receiving element are provided opposite to each other in order to detect a damage-response type earthquake detection and to detect a movement in a pendulum axis, for example, for setting a predetermined amplitude between the two elements. Since a control plate having a slit is interposed and a signal is output from the light receiving element by light blocking or light receiving due to the shake of the control plate, the following effects are obtained.

A. Unlike the conventional vibration velocity detection type sensor, the principle of electromagnetic induction is not employed, so that it is not affected by electromagnetic wave noise at all. As a result, it is possible to obtain a seismic sensor free from a malfunction. b. Since no electromagnetic coil is used, the production cost is low.
As a result, it is effective when constructing a safety system for earthquake countermeasures over a wide area. c. By providing a plurality of control circuits, this control circuit
Depending on the setting of the signal output from the
Set the magnitude of vibration when moving as many as the number of control circuits
can do.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an earthquake sensor according to the present invention.

FIG. 2 is a plan view of a control plate.

FIG. 3 is an explanatory view of a falling ball type earthquake sensor.

FIG. 4 is an explanatory diagram of a pendulum type earthquake sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pendulum axis 2 Gimbal fulcrum 3 Light emitting element 4 Light receiving element 5 Slit 6 Control plate 7 Braking board 8 Permanent magnet 9 Amplifier 10 Relay contact 11 Control circuit 12 Support base

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isamu Yokoi 2-25-1, Nishi-Nippori, Arakawa-ku, Tokyo Within Tokyo Seismic Inc. (56) References JP-A-53-102787 (JP, A) 60-181675 (JP, U) Fully open Showa 61-197525 (JP, U) Fully open Showa 56-74329 (JP, U) Fully open Showa 56-92931 (JP, U) (58) Fields investigated (Int) .Cl. ⁶ , DB name) G01V 1/00 G01H 1/00

Claims (1)

(57) [Claims] 1. A pendulum configured to obtain a motion in all directions in direct proportion to a vibration speed by an overbraking mechanism, and a displacement of the pendulum is detected by an optical sensor. And a control circuit configured to output the vibration signal .
Attach a disk-shaped control plate to the pendulum and
Light shielding or multiple light shielding with different light transmission areas
Or forming a light-transmitting portion, and further forming the respective light-shielding or light-transmitting portions.
The light-emitting element and light-receiving element of the control circuit
And switch the signal from each light receiving element
Control signal output from the control circuit.
Vibration velocity detection type earthquake configured to be able to select a signal
Sensor.