JP2000266593A - Non-power vibration detection sensor - Google Patents

Abstract

(57) [Problem] To provide a vibration detection unit composed of an optical passive component that does not require power supply at a vibration measurement point, and to detect vibration at a low cost without requiring a signal transmission device or the like. To provide a powerless vibration detection sensor. A light reflection measurement device that emits light of a single wavelength and measures the intensity of return reflected light, a light vibration detection unit that detects vibration, the light vibration detection unit, and the light reflection measurement device And an optical fiber for connecting the two.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration detecting sensor used for disaster prevention and the like, and more particularly to a non-power-supply vibration detecting sensor which does not require a power supply by using an optical passive component.

[0002]

2. Description of the Related Art FIG. 3 is a schematic configuration diagram of a conventional vibration detecting sensor used for the purpose of disaster prevention or the like. 21 is a pendulum,
22 is a detector, 23 is an amplifier, 24 is a magnet coil, 25 is a vibration detector, and 26 is a measurement display device. The vibration detection sensor includes a vibration detector 25 and a measurement display device 26. The vibration detector 25 is connected to the pendulum 21
, A detector 22, an amplifier 23, and a magnet coil 24, and are installed at a position where vibration is detected.

The pendulum 21 built in the vibration detector 25
If the balance is slightly distorted due to the acceleration due to external vibration, an electric signal 27 corresponding to the angular displacement is generated in the detector 22 from the equilibrium point of the pendulum 21. The electric signal 27 is amplified by the amplifier 23 and applied to the magnet coil 24 to generate a magnetic force that always returns the pendulum 21 to the equilibrium point. At this time, the current flowing through the magnet coil 24 is proportional to the vibration acceleration, and can be detected as a voltage proportional to the vibration acceleration through a reading resistor (not shown). This voltage is measured by the measurement display device 26, and the degree of vibration can be detected.

[0004]

In the conventional vibration detection sensor, it is necessary to install the vibration detector 25 at a position where vibration is detected, but it is necessary to supply power to the vibration detector 25 at the measurement position. In addition, when monitoring vibration remotely, it is necessary to transmit a signal from the vibration detector 25 to the measurement display device 26 wirelessly or by wire. Therefore, a wireless or wired transmission device is required, and the cost of the vibration detection sensor is reduced. Was higher.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned disadvantages of the prior art, to provide a vibration detecting section composed of an optical passive component which does not require power supply at a vibration measuring point, and to provide a signal transmission device even remotely. It is an object of the present invention to provide a non-power-supply vibration detection sensor that can detect vibration at low cost without the need for such a device.

[0006]

According to the present invention, there is provided a light reflection measuring device for emitting light of a single wavelength and measuring the intensity of return reflected light, and an optical vibration detecting device for detecting vibration. It is composed of a detecting section and an optical fiber connecting the light vibration detecting section and the light reflection measuring device.

The light vibration detecting section includes a light incident section for guiding the light of the single wavelength from the optical fiber to the condensing lens, and an optical vibration detecting section for oscillating the light of the single wavelength condensed by the condensing lens. And a total reflection mirror for returning the light of a single wavelength to which the loss has been added to the light reflection measuring device.

Further, the pendulum type optical attenuator has a semicircular optical attenuator having a transmittance different from place to place, an arm attached to a lower part of the semicircular optical attenuator, and an inertia weight attached to a lower part of the arm. The semicircular optical attenuator is constituted by a bearing so that the semicircular optical attenuator moves in an arc when vibration is applied.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing one embodiment of a non-power-supply vibration detecting sensor according to the present invention, wherein 1 is a light reflection measuring device, 2 is an optical fiber, and 3 is a light vibration detecting device. Part 4,
Is light of a single wavelength, and 5 is reflected light. The non-power-supply vibration detecting sensor includes a light reflection measuring device 1, an optical fiber 2, and a light vibration detecting unit 3. The light vibration detection unit 3 is installed at a position where vibration is detected.

The light reflection measuring device 1 is a device that emits light 4 of a single wavelength and measures the light intensity (sometimes simply referred to as intensity) of the returned reflected light 5.

The light vibration detecting section 3 includes a light incident section 6, a condenser lens 7, a pendulum type optical attenuator 8, and a total reflection mirror 9. Emitted from the light reflection measuring device 1,
The light 4 of a single wavelength propagated by the optical fiber 2 is condensed by a light condensing lens
Lead to. The single-wavelength light 4 condensed by the condensing lens 7 is incident on a pendulum-type optical attenuator 8.

FIG. 2 is an explanatory diagram of the pendulum type optical attenuator 8. Reference numeral 10 denotes a semicircular optical attenuator, 11 denotes an inertial weight, 12 denotes an arm, and 13 denotes a bearing. The semicircular optical attenuator 10 is divided into a fan shape at a certain angle,
They are configured so that their light transmittances are different. An arm 12 is attached to a lower part of the semicircular optical attenuator 10, and an inertial weight 11 is attached to a lower part of the arm 12.

The semicircular optical attenuator 10 is configured to make a circular motion around the bearing 13 by vibration applied to the entire optical vibration detection unit 3 from the outside. For example, the loss received by the single-wavelength light 4 in a stationary state is set to zero, and when the semicircular optical attenuator 10 oscillates left and right, the loss received increases as the amount of shake increases.

Accordingly, the light 4 having a single wavelength is subjected to a loss corresponding to the degree of vibration detected by the light vibration detecting unit 3 by the pendulum type optical attenuator 8, reflected by the total reflection type mirror 9, and reflected by the reflected light 5. And return to the light reflection measuring device 1.
For example, when the applied vibration is large, the semicircular optical attenuator 10 touches greatly. Then, inertial weight 1
According to 1, the semicircular optical attenuator 10 reciprocates left and right around the bearing 13, and the loss that the semicircular optical attenuator 10 receives increases as the amount of deflection of the semicircular optical attenuator 10 increases. When the reflected light 5 is observed on the time axis, the intensity of the reflected light 5 is sinusoidal with respect to time, and the amplitude is attenuated.

The light reflection measuring device 1 captures the intensity of the reflected light 5 that changes with time as the intensity of the vibration in the optical vibration detecting section 3 and outputs the result to an external device. In addition,
Even if the light vibration detection unit 3 does not vibrate, the reflected light 5 changes at a certain level, but this change width is set as a noise level, and the level of light that changes beyond this level is set as the vibration amount. Measure.

As described above, since the optical vibration detecting section 3 is composed of only optical passive components, no power supply is required. In addition, the light 4 of a single wavelength emitted from the light reflection measuring device 1 is guided to the optical vibration detecting unit 3 by the optical fiber 2, and the degree of vibration is determined by the intensity of the reflected light 5 reflected from the optical vibration detecting unit 3. In order to perform the detection, remote monitoring can be performed with only one optical fiber 2, so that the cost of the non-power-supply vibration detection sensor can be reduced. A pendulum type optical attenuator 8 having a circular optical attenuator 10 and a total reflection type mirror 9 are used to generate reflected light 5 whose intensity varies depending on the degree of vibration.
However, if the semicircular optical attenuator 10 is configured to have a different reflectance at each fan portion, the total reflection mirror 9 can be omitted. In short, any method may be used as long as the intensity of the single-wavelength light 4 changes when the light-vibration detecting unit 3 receives vibration, and there is a means for reflecting the intensity.

[0017]

According to the non-power-supply vibration detecting sensor of the present invention, there is no need to supply power since the vibration detecting section for detecting vibration is constituted by optical passive components. In addition, the light of a single wavelength emitted from the light reflection measuring device is guided to the optical vibration detection unit via an optical fiber, and the degree of vibration is detected by the intensity of the reflected light reflected from the optical vibration detection unit. Can be monitored using only one optical fiber, so that the cost of the non-power source vibration detection sensor can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a powerless vibration detection sensor of the present invention.

FIG. 2 is a schematic configuration diagram of a pendulum type optical attenuator of FIG. 1;

FIG. 3 is a schematic configuration diagram of a conventional vibration detection sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical reflection measuring device 2 Optical fiber 3 Optical vibration detection part 4 Light of a single wavelength 5 Reflected light 6 Light incidence part 7 Condensing lens 8 Pendulum type optical attenuator 9 Total reflection type mirror 10 Semicircular optical attenuator 11 Inertial weight DESCRIPTION OF SYMBOLS 12 Arm 13 Bearing 21 Pendulum 22 Detector 23 Amplifier 24 Magnet coil 25 Vibration detector 26 Measurement display device 27 Electric signal

Claims (3)

[Claims] 1. A light reflection measuring device that emits light of a single wavelength and measures the intensity of return reflected light, a light vibration detecting unit that detects vibration, the light vibration detecting unit, and the light reflection measuring device. A non-power-supply vibration sensor. A light incident portion for guiding light of a single wavelength from the optical fiber to a condensing lens; and a light vibration detecting portion for oscillating the light of a single wavelength condensed by the condensing lens. 2. The non-power source according to claim 1, further comprising a pendulum-type optical attenuator that adds a loss depending on the degree of reflection, and a total reflection mirror that returns the single wavelength light to which the loss has been added to the light reflection measuring device. Vibration detection sensor. 3. A pendulum type optical attenuator comprising: a semicircular optical attenuator having a transmittance different from place to place; an arm attached to a lower part of the semicircular optical attenuator; and an inertial weight attached to a lower part of the arm. 3. The non-power source vibration detection sensor according to claim 2, wherein the semicircular optical attenuator is configured to perform a circular motion when a vibration is applied.