JPH1164096A - Spiral-type acceleration seismograph apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acceleration seismograph apparatus which can efficiently detect earthquakes by a dividing vibrations into horizontal vibration or vertical vibration directions, etc. SOLUTION: A spiral acceleration seismograph apparatus is constituted by spirally arranging a coaxial piezoelectric material 11 on a horizontal plate 16 and fixing one end of the piezoelectric material with a fixing end 4, with the other end being connected to a vibration detecting body 15. When vibrations are transmitted from the outside, then the detecting body 15 vibrates leftward and rightward on the horizontal plate 16 and the voltage corresponding to the vibration of the detecting body 15 is generated across an inner electrode 12 and an outer electrode 13. The period and magnitude of the vibration can be detected from the voltage output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration detector for detecting vibration, and more particularly to a spiral type vibration detector effective for detecting an earthquake.

[0002]

2. Description of the Related Art A conventional vibration detecting device of this type is generally described in Japanese Patent Application Laid-Open No. 61-160026. The conventional vibration detecting device 1 shown in FIG. 10 has a configuration including a spherical weight 4 held on a mortar-shaped bottom 3 in a storage container 2 and a switch 5 that opens and closes electrical contacts by the load of the weight 4. there were. When vibration such as an earthquake is transmitted to the storage container 2, the spherical weight 4 moves up and down or left and right from the mortar-shaped bottom 3. By this movement, the load of the spherical weight 4 applied to the load transmitting rod 7 that has pushed up the lever 6 of the switch 5 is removed. As a result, the switch 5 operates to turn on and off between the electric terminals 8 and 9, thereby detecting that vibration has occurred.

[0003]

However, in the above-described conventional configuration, the presence or absence of vibration can be detected.
The magnitude of the vibration could not be detected. For this reason, impact vibration generated when a ball or the like hits is also detected as vibration due to an earthquake, and a malfunction may occur. Also,
Neither horizontal vibration nor vertical vibration could be detected separately.

[0004]

According to the present invention, there is provided a spiral-type piezoelectric body having coaxial electrodes,
A configuration was made up of a flat plate that holds the piezoelectric body and a fixing portion that fixes one end of the piezoelectric body. With this configuration, when vibration is applied from the outside, the spiral piezoelectric body having the coaxial electrode vibrates on the flat plate and deforms around the fixed portion. Due to the deformation of the spiral piezoelectric body, a voltage is generated in the coaxial electrode by the piezoelectric effect. By detecting the generated voltage, the occurrence of the vibration and the magnitude of the vibration can be known, and the device operates as a vibration detector or an earthquake detector.

Also, a spiral piezoelectric body having a rectangular cross section, two pairs of electrodes provided on opposing flat surfaces of the piezoelectric body,
The structure includes a spiral type elastic body for fixing the piezoelectric body and a fixing part for fixing one end of the elastic body. With this configuration, when vibration is applied from the outside, the spiral-shaped piezoelectric body having a rectangular cross section vibrates vertically and horizontally around the fixed portion, and is deformed. For this reason, a voltage is generated in each of the electrodes provided on two pairs of opposing planes having a rectangular cross section due to the deformation of the spiral piezoelectric body depending on the vertical and horizontal directions. By detecting the voltage generated at each of the electrodes, the occurrence of vibration and the magnitude of vertical and horizontal vibrations can be known, and the device operates as a vibration detector or an earthquake detector.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention comprises a spiral piezoelectric body having coaxial electrodes, a flat plate for holding the piezoelectric body, and a fixing part for fixing one end of the piezoelectric body. With this configuration, when vibration is applied from the outside, the spiral piezoelectric body having the coaxial electrode vibrates on the flat plate and deforms around the fixed portion. Due to the deformation of the spiral piezoelectric body, a voltage is generated in the coaxial electrode by the piezoelectric effect. By detecting the generated voltage, the occurrence of the vibration and the magnitude of the vibration can be known, and the device operates as a vibration detector or an earthquake detector.

[0007] A spiral type piezoelectric body having coaxial electrodes, a spiral type elastic body for fixing the piezoelectric body, and a fixing portion for fixing one end of the elastic body are provided. With this configuration, when vibration is applied from the outside, the spiral elastic body vibrates in the vertical and horizontal directions around the fixed portion. Therefore, the spiral piezoelectric body having the coaxial electrode fixed to the elastic body also vibrates and deforms in the vertical and horizontal directions. A vertical and horizontal deformation of the spiral piezoelectric body generates a voltage on the coaxial electrode by a piezoelectric effect. This generated voltage is detected,
It is possible to know that vertical and horizontal vibrations have occurred and the magnitude of the vibrations, and it operates as a vibration detector or an earthquake detector.

[0008] Further, a spiral type piezoelectric body having coaxial electrodes and a fixing portion for fixing one end of the piezoelectric body are provided. With this configuration, when vibration is applied from the outside, the spiral piezoelectric body vibrates in the vertical and horizontal directions around the fixed portion. Therefore, a voltage is generated on the coaxial electrode in accordance with vertical and horizontal vibrations and deformation of the spiral piezoelectric body. By detecting the generated voltage, the occurrence of vertical and horizontal vibrations and the magnitude of the vibration can be known, and the device operates as a vibration detector or an earthquake detector.

A spiral piezoelectric body having a rectangular cross section, a pair of electrodes provided on opposing flat surfaces of the piezoelectric body,
A configuration was made up of a flat plate that holds the piezoelectric body and a fixing portion that fixes one end of the piezoelectric body.

According to this configuration, when vibration is applied from the outside, the spiral type piezoelectric body having a rectangular cross section vibrates on the flat plate and deforms around the fixed portion. Due to the deformation of the spiral piezoelectric body, a voltage is generated by the piezoelectric effect on the electrodes provided on the opposing flat surfaces of the rectangular cross section. By detecting the generated voltage, the occurrence of the vibration and the magnitude of the vibration can be known, and the device operates as a vibration detector or an earthquake detector.

A spiral type piezoelectric body having a rectangular cross section, two pairs of electrodes provided on opposing flat surfaces of the piezoelectric body,
The structure includes a spiral type elastic body for fixing the piezoelectric body and a fixing part for fixing one end of the elastic body. With this configuration, when vibration is applied from the outside, the spiral elastic body vibrates in the vertical and horizontal directions around the fixed portion. Therefore, the spiral type piezoelectric body having a rectangular cross section fixed to the elastic body also vibrates vertically and horizontally,
It will be deformed. Voltage is generated by the piezoelectric effect on each of two pairs of electrodes provided in a rectangular cross section due to vertical and horizontal deformation of the spiral piezoelectric body. By detecting each of the generated voltages, it is possible to know that vertical and horizontal vibrations have been generated and the magnitude of each of the vibrations, and the device operates as a vibration detector or an earthquake detector.

A spiral-type piezoelectric body having a rectangular cross section; two pairs of electrodes provided on opposing flat surfaces of the piezoelectric body;
The piezoelectric body was constituted by a fixing portion for fixing one end of the piezoelectric body. With this configuration, when vibration is applied from the outside, the spiral piezoelectric body having a rectangular cross section vibrates in the vertical and horizontal directions around the fixed portion. Therefore, a voltage is generated at each pair of electrodes provided in a rectangular cross section in accordance with vertical and horizontal vibrations and deformation of the spiral piezoelectric body having a rectangular cross section. By detecting each of the generated voltages, it is possible to know independently that the vertical and horizontal vibrations have occurred and the magnitude of each of the vibrations, and it operates as a vibration detector or an earthquake detector.

Further, the rectangular ratio of the rectangular cross section is configured to be a predetermined sensitivity ratio. With this configuration, it is possible to adjust the output voltage due to the vertical vibration and the horizontal vibration. Therefore, by comparing this output voltage, the magnitude of the vertical vibration and the magnitude of the horizontal vibration can be directly compared, and the apparatus can be operated as a more accurate vibration detector or earthquake detector. .

[0014] Further, a configuration is provided in which an output signal is obtained by adding the signals from the two pairs of electrodes with weighting. For example, if each output signal is configured to output the sum of the squares of the absolute values of the output signals, the magnitude of the three-dimensional vibration can be matched, and the device effectively operates as an earthquake detector.

[0015]

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

(Embodiment 1) FIG. 1 is an external view of a seismic sensor 10 according to Embodiment 1 of the present invention. In the figure, 11 is a coaxial piezoelectric body, 12 is a coaxial inner electrode, 13 is a coaxial outer electrode,
14 is a fixed end of the coaxial piezoelectric body 11 and 15 is a coaxial piezoelectric body 11
The vibration detecting body provided at the other end of the
2 shows a horizontal plate for holding the horizontal. FIG. 2 shows a main part of a coaxial piezoelectric body 11 having an outer diameter of about 3 mm, which is composed of a coaxial inner electrode 12, a piezoelectric body 17, a coaxial outer electrode 13, and an insulating coating 18 in order from the inside. The spiral type piezoelectric body 11
Has a total length of about 20 mm and is made of a piezoelectric polymer such as PVDF. A voltage is generated between the inner electrode 12 and the outer electrode 13 by applying a stress such as expansion and contraction to the piezoelectric body.

The horizontal plate 16 is made of a plate having a smooth surface such as Teflon, glass, ceramic, or metal plate so that the coaxial piezoelectric body 11 can move freely. When vibration is transmitted from the outside to the seismic sensor 10 having such a configuration,
The vibration detector 15 (brass of φ10 mm, height 5 mm) having large inertia vibrates on the horizontal plate 16. Due to this vibration, the coaxial piezoelectric body 11 between the fixed end 14 and the vibration detecting body 15 partially generates bending vibration in the vibration direction or a direction perpendicular to the vibration direction, and the inner electrode 12 and the outer electrode 13, a voltage output is obtained. FIG. 3 shows a voltage output waveform 19 observed by an oscilloscope with the horizontal axis representing time and the vertical axis representing voltage. By detecting the output voltage, the period and magnitude of the vibration can be detected. In this embodiment, the fixed end is set at the outer periphery and the vibration detector is set at the center, but the same effect can be obtained even if the opposite is true. Further, in this embodiment, the vibration detector 15 is made of brass, but an extra coaxial piezoelectric body 11 may be collectively used.

(Embodiment 2) FIG. 4 is an external view of a seismic sensor 20 according to Embodiment 2 of the present invention. 11 is a coaxial piezoelectric body,
It was fixed on an elastic body 21 composed of a spiral leaf spring with an adhesive or the like. Reference numeral 15 denotes the vibration detector shown in the first embodiment, which is provided at the center and the outer periphery is the fixed end 14. When vibration is transmitted from the outside to the seismic device 20 having this configuration, the vibration detector 15 vibrates. In this case, since it is constituted by a spiral leaf spring, the vibration detector 15 vibrates particularly well in the vertical direction. This vibration causes the coaxial piezoelectric body 1
1 was subjected to bending vibration over the entire length, and a voltage output waveform 22 as shown in FIG. 5 was obtained between the inner electrode 12 and the outer electrode 13 using an oscilloscope. The output voltage waveform was symmetric. By detecting the output voltage waveform, the period and magnitude of the vibration can be detected. In this embodiment, the fixed end is set at the outer periphery and the vibration detector is set at the center, but the same effect can be obtained even if the opposite is true.

(Embodiment 3) FIG. 6 is an external view of a seismic sensor 23 according to Embodiment 3 of the present invention. 11 is a coaxial piezoelectric body,
A spiral spring material was used for the inner electrode wire 24 to form a coaxial piezoelectric body. 25 is a fixed end, 15 is a vibration detecting body.

When vibration is applied to the seismic sensor 23 having such a structure from the outside, the vibration detector 15 vibrates up, down, left, and right.

Due to this vibration, a voltage is generated between the inner electrode 24 and the outer electrode 26 of the coaxial piezoelectric body 11 due to the vibration. By detecting the generated voltage, the direction and magnitude of the vibration can be detected. This seismic device 2
Since the third vibration detector 15 can vibrate in any direction, up, down, left, and right, it can vibrate in response to external vibrations in any direction. Therefore, if only the voltage generated between the inner electrode 24 and the outer electrode 26 of the coaxial piezoelectric body 11 is detected, all vibrations can be dealt with, and the device operates as an excellent vibration detector. In the above embodiment, the inner electrode is a wire made of a spring material. However, the inner electrode may be made of a spring material having a rectangular cross section. For example, if it is made of a spring material having a vertically long rectangular cross section, the sensitivity to vibration in the vertical direction can be suppressed, and the sensitivity to vibration in the horizontal direction can be increased. By adjusting the sensitivity to the vertical and horizontal vibrations in this way, an effective seismic device can be provided for an earthquake that is a three-dimensional vibration. That is, it is possible to calculate the seismic intensity of the earthquake only by detecting a single output voltage. In this embodiment, the fixed end is set at the outer periphery and the vibration detector is set at the center, but the same effect can be obtained even if the opposite is true.

(Embodiment 4) FIG. 7 is an external view of a seismic sensor 27 according to Embodiment 4 of the present invention. Reference numeral 28 denotes a spiral-type piezoelectric body having a rectangular cross section, which is made of piezoelectric ceramic. PZT, PCM, or the like was used as the piezoelectric ceramic. 29,
Reference numeral 30 denotes electrodes provided on the upper and lower surfaces of the spiral type piezoelectric ceramic. Reference numeral 31 denotes a fixing portion for fixing the outer peripheral portion of the spiral type piezoelectric ceramic. The thickness of the spiral piezoelectric ceramic 28 was about 1 mm, the width was about 3 mm, and the outer diameter was about 20 mm. Reference numeral 32 denotes a vibration detector. When vibration is transmitted from the outside to the seismic sensor 27 having such a configuration, the vibration detector 32
Will vibrate vertically and horizontally. The spiral type piezoelectric member has a particularly high sensitivity to the vertical vibration of the vibration detector 32, that is, the vibration in the direction perpendicular to the upper and lower electrode surfaces, because the spiral piezoelectric member is bent in the same direction in the vertical direction over the entire length. Therefore, a large output voltage is obtained between the upper electrode 29 and the lower electrode 30 by vibrating the vibration detector 32 vertically. By detecting the output voltage, the period and magnitude of the vibration can be detected. By reducing the thickness of the piezoelectric ceramic 28, it is more flexed,
The output voltage can be increased. In this embodiment, the fixed end is set at the outer periphery and the vibration detector is set at the center, but the same effect can be obtained even if the opposite is true.

(Embodiment 5) FIG. 8 is an external view of a seismic sensor 33 according to Embodiment 5 of the present invention. Numeral 34 denotes a spiral type piezoelectric body having a rectangular cross section, which is made of piezoelectric ceramic. PZT, PCM, or the like was used as the piezoelectric ceramic. 35,
Reference numeral 36 denotes electrodes provided on the upper and lower surfaces of the spiral piezoelectric ceramic, and reference numerals 37 and 38 denote electrodes provided on the inner and outer surfaces of the spiral piezoelectric ceramic. Reference numeral 39 denotes a fixing portion for fixing the outer peripheral portion of the spiral type piezoelectric ceramic. The thickness of the spiral piezoelectric ceramic 34 is about 3 mm, and the width is about 1 m.
m, and the outer diameter was about 20 mm. 40 is a piezoelectric ceramic 3
1 shows a vibration detector provided at the center of FIG. In this embodiment, the piezoelectric ceramic 34 has a vertically long rectangular cross section, and is largely bent against vibration in the left-right direction. When vibration is transmitted from the outside to the seismic sensor 33 having such a configuration,
The vibration detector 40 vibrates in the vertical and horizontal directions. In response to the vertical vibration of the vibration detector 40, that is, the vibration in the direction perpendicular to the upper and lower electrode surfaces, the spiral piezoelectric body bends in the same vertical direction over the entire length thereof, so that the upper electrode 35 and the lower electrode 36 A voltage is generated during Further, in response to the vibration in the left-right direction, the spiral piezoelectric body is bent in the left-right direction over the entire length, so that a voltage is generated between the inner electrode 37 and the outer electrode 38. Therefore, by detecting these two output voltages, the vertical vibration and the horizontal vibration can be separately detected for the period and magnitude of the vibration. In this embodiment, the fixed end is set at the outer periphery and the vibration detector is set at the center, but the same effect can be obtained even if the opposite is true. Further, by appropriately selecting the rectangular ratio of the piezoelectric ceramic, the sensitivity to the vibration in the horizontal direction and the sensitivity to the vibration in the vertical direction can be adjusted to approximately the same level. Moreover, since the sensitivity to each vibration can be set in advance, it is also possible to calculate the seismic intensity from, for example, an earthquake in the magnitude of each vibration.

(Embodiment 6) FIG. 9 shows a signal output block diagram of a vibrator 33 made of a spiral type piezoelectric ceramic according to Embodiment 5 of the present invention. 34 shows a cross section of the piezoelectric ceramic, 35 and 36 are upper and lower electrodes, 37 and 38 are inside,
3 shows an outer electrode. Reference numerals 39 and 40 denote amplifiers, which amplify the voltage generated in the piezoelectric ceramic 34. The voltage output (Vp) amplified by the amplifier 39 and the voltage output (Vh) amplified by the amplifier 40 are combined by the operation output unit 41, and the combined output (Vout) is output to the signal terminal 42. In the arithmetic output unit 41, the respective voltage outputs (Vp) and (Vh) are
(1) Addition or weighting and addition,
(2) adding an absolute value, adding an absolute value with a weight, (3) adding a square value, or adding a square value with a weight, (4) multiplying each product And (5) the function of calculating the product of each squared value. For example, each voltage output (V
If the value obtained by adding the square values of (p) and (Vh) with weight is further converted to logarithmic output, it becomes possible to make the value very close to the magnitude of the vibration, for example, the seismic intensity of the earthquake. .

[0025]

As is apparent from the above description, the following effects can be obtained according to the vibrating vibrator of the present invention.

(1) Since the coaxial spiral piezoelectric body is supported so as to vibrate on the horizontal plate, the period and magnitude of the horizontal vibration can be detected.

(2) Since the coaxial piezoelectric body is fixed to the spiral elastic body, the period and magnitude of the vertical vibration can be detected.

(3) Since the spiral type is constituted by the coaxial piezoelectric body, the period and magnitude of the vibration in the vertical and horizontal directions can be detected.

(4) Since a different spiral type is constituted by a piezoelectric body having a rectangular cross section and electrodes are provided on upper and lower surfaces, it is possible to detect the period and magnitude of vertical vibration.

(5) A different spiral type is constituted by a piezoelectric body having a rectangular cross section, and two pairs of electrodes are provided on the upper and lower surfaces and on the inner and outer surfaces. The size can be detected independently.

(6) Since a different spiral type is constituted by a piezoelectric body having a rectangular cross section and two pairs of electrodes are provided on the upper and lower surfaces and on the inner and outer surfaces, a voltage output by vibration in the vertical and horizontal directions is obtained. Is calculated and output, so that an output corresponding to the seismic intensity of the earthquake can be obtained.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a spiral type seismic sensor according to a first embodiment of the present invention.

FIG. 2 is an external perspective view showing a coaxial piezoelectric body of the seismic sensor.

FIG. 3 is a voltage output waveform diagram of the same seismic sensor.

FIG. 4 is an external perspective view of a spiral type seismic sensor according to a second embodiment of the present invention.

FIG. 5 is a voltage output waveform diagram of the same seismic sensor.

FIG. 6 is an external perspective view of a spiral type seismic sensor according to a third embodiment of the present invention.

FIG. 7 is an external perspective view of a spiral type seismic sensor according to a fourth embodiment of the present invention.

FIG. 8 is an external perspective view of a spiral type seismic sensor according to a fifth embodiment of the present invention.

FIG. 9 is a circuit diagram of a spiral type seismic sensor according to a sixth embodiment of the present invention.

FIG. 10 shows a conventional seismic sensor.

[Explanation of symbols]

 10, 20, 23, 27, 33 Seismic sensor 11 Coaxial piezoelectric body 12 Coaxial inner electrode 13 Coaxial outer electrode 14, 25 Fixed end 15, 32, 40 Vibration detector 16 Horizontal plate 17, 28, 34 Piezoelectric body 21 Elastic body 24 Inner electrode wire 26 Outer electrode 29, 35 Upper electrode 30, 36 Lower electrode 31, 39 Fixed part 37 Inner electrode 38 Outer electrode

Claims (7)

[Claims] 1. A spiral type seismic sensor comprising a spiral type piezoelectric body having coaxial electrodes, a flat plate holding the piezoelectric body, and a fixing part for fixing one end of the piezoelectric body. 2. A spiral type seismic sensor comprising a spiral type piezoelectric body having coaxial electrodes, a spiral type elastic body for fixing the piezoelectric body, and a fixing part for fixing one end of the elastic body. 3. A spiral type seismic sensor comprising a spiral type piezoelectric body having coaxial electrodes and a fixing portion for fixing one end of the piezoelectric body. 4. A spiral piezoelectric body having a rectangular cross section, a pair of electrodes provided on a flat surface facing the piezoelectric body, a flat plate for holding the piezoelectric body, and a fixing portion for fixing one end of the piezoelectric body. A swirl type seismic sensor consisting of 5. A spiral type seismic sensor comprising a spiral type piezoelectric body having a rectangular cross section, two pairs of electrodes provided on opposing flat surfaces of the piezoelectric body, and a fixing portion for fixing one end of the piezoelectric body. . 6. The spiral type seismic sensor according to claim 5, wherein a rectangular ratio of the rectangular cross section is set to a predetermined sensitivity ratio. 7. The spiral type seismic sensor according to claim 6, which has an output signal obtained by adding weighted signals from two pairs of electrodes.