JPH0318787A - Seismographic device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a seismic sensing device for sensing earthquakes, which is difficult to operate due to shocks such as those caused by collisions with objects, and has little variation in operating width depending on the type of seismic waves. The purpose is to provide a seismic sensing device.

BACKGROUND OF THE INVENTION As shown in FIG. 9, a conventional seismic sensor of this type includes a seismic sensor 1 that generates a signal that repeatedly turns on and off due to vibrations with a predetermined amount of acceleration, and a period of on and off. A specified on-off time that monitors the width and detects that the number of on-times equal to or greater than the specified on-time + PM with an off period greater than or equal to the specified off-time width is greater than or equal to the specified number of times within a specified time. In the event of an earthquake, as shown in Figure 10, the operation is as shown in Figure 10. Among the on/off signals of
(s) or more on 2 is considered as the first time, then off 3 is more than the specified off time width Toff (s), and then on 5 is more than the specified on time width Ton (s). is defined as the 2nd@th, and in the same way, the ON n that is longer than the specified ON time width with an OFF n-1 that exceeds the specified OFF time width is defined as the MS time of the specified number of times, and this is shown in b). If it is within the specified time Ts from the first turn on, the repeated on/off signal of the seismic sensor in b) is judged to be an earthquake signal and is output from the output terminal 3 in Figure 9. This seismic sensing device was working.

Then, even after the specified time Ts has elapsed, if the number of ON times that satisfy the specified conditions does not reach the specified number Ms, and the on/off signal of the seismic sensor continues to be generated,
The next specified time Ts starts anew from the next rising edge of ON, and exactly the same detection is performed. Also,
The vibration waveform (acceleration waveform) caused by an impact such as when an object collides with an object is generally attenuated by the natural vibration of the location where the seismic sensing device is installed, as shown in Figure 11a), and the The on/off signal of the seismic sensor is shown in Figure 9(b)~
As shown in (d), the on-time width tends to gradually decrease and the off-time width gradually increases, but the vibration l'ii
Since the l period itself is always constant, the sum of the on and off time widths is constant, that is, as shown in Figure 11 e), Ton(i) + Toff(+) = A
(const.) − (1), and since this period A is normally shorter than the average period of seismic waves, the prescribed on-time width Ton (s
) and off time width Toff(s) as Ton(s) + Toff(s) > A
=−−−−−−・−・−(2), and in the event of an impact, the detection means should output as little as possible for the number of times exceeding the specified on/off time width (this seismic sensing device (designed to prevent malfunction).

Problems to be Solved by the Invention However, since the operating value when the seismic sensing device operates due to seismic waves is expressed by the maximum peak gal value of the seismic wave (maximum amplitude value of the acceleration waveform of the seismic wave), conventional If an earthquake is determined after counting the on/off signals of a seismic sensor, such as a device,
The operating values may vary significantly depending on the type of seismic waveform, and as a result, there is a risk that the seismic sensing device will have large variations in operation depending on the type of seismic wave.

For example, if the specified number of ON times for this device to determine an earthquake is 5 times (Ms = 5), and the specified acceleration at which the seismic sensor generates an ON signal is 100 gal, then Figure 12a
) The maximum peak gal value is 300 gal, which is large at best} 2 When a direct seismic wave arrives only 2 to 3 times, the number of times the seismic sensor is turned on is as shown in Figure 12b). This device does not work because there are only 3 times, and on the contrary, the 13th time
Even though the maximum peak gal value is as small as 150 gal as shown in Figure 13 (a), when a continuous seismic wave with large shaking that continues many times comes, the number of times the seismic sensor is turned on is as shown in Figure 13 (b). If this happens 5 times or more, this means that the device is working. In other words, even though it operates at 150 gal in a continuous earthquake,
In the case of a direct earthquake, the seismic sensing device would not operate even at 300 gal, resulting in a seismic device with large variations in operation. In addition, the 12th
In Fig. 13, all the on/off signals of the seismic device are longer than the specified on time width Ton (s) or the specified off time width Toff (s), and all the on signals are from the first rising edge of the on signal. It is assumed that the time is within the specified time Ts. In addition, the frequency characteristics of the motion acceleration of the seismic sensor are also constant (
Here, the speed at which the seismic sensor generates an ON signal at any frequency is assumed to be 100 gal. Therefore, the first object of the present invention is to provide a seismic sensing device that can determine its operation based on the magnitude of the maximum peak gal value of any seismic wave.

The second purpose is also by the above means! To obtain a vibration sensing device which does not increase malfunctions when an i-fire occurs.

The third object is to provide a vibration sensor that can more reliably achieve the above two objects.

Means for Solving the Problems In order to achieve the above-mentioned first object, the present invention includes on-time width detection means for detecting when the on-time width of the seismic sensor exceeds a specified on-time width. It is something that

In addition to the above, in order to achieve the second object, the present invention also deals with fluctuations in the on and off times of the seismic sensor or the sum of the on and off time widths within a specified time. An on/off time width fluctuation state detection means is provided which calculates the state and detects that the fluctuation value is equal to or greater than a specified fluctuation value, and the on/off time width fluctuation state detection means and the on/off time width fluctuation state detection means are provided. The output signal is generated only when both outputs are generated.

Furthermore, in order to achieve the third object, the present invention provides a vibration detection mechanism of a seismic sensor with a damping characteristic that increases the duration of the ON state.

Function: Due to the above-mentioned I#I power, the seismic sensing device of the present invention operates even if the number of times is (@) as long as the on-signal of the seismic sensor is longer than the specified on-time width. This specified on-time width is set to be shorter than the time width of the seismic sensor's on-signal that occurs at the maximum beak gal value during an earthquake, and longer than the time width of the seismic sensor's on-signal that occurs during an impact. By selecting it, it will not operate under impact.
In addition, in the event of an earthquake, no matter what the seismic waveform is, the maximum peak gal value will always operate at an operating value in the vicinity of slightly exceeding the specified acceleration, reducing variations in operation depending on the type of seismic wave.

In addition, the on/off time width fluctuation state detection means outputs regular on/off signals of the seismic sensor due to vibrations with a certain natural period that occur during impact, even if the on signal exceeds the specified on time width. Therefore, by generating an output signal only when the outputs of both the on/off time width fluctuation state detection means and the on time width detection means are generated, malfunctions in the event of an impact can be prevented. will not increase.

Furthermore, by providing the vibration sensor's vibration detection mechanism with a damping characteristic that increases the ON duration, the on-signal of the seismic sensor that is generated at the maximum peak gal value during an earthquake can be made stronger than that generated during an impact. This allows for a clear distinction.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

In Fig. 1, 4 is a seismic sensor that generates a signal that repeatedly turns on and off due to vibrations at a specified amount of acceleration, and 5 monitors the on-time width of the seismic sensor 4, which is the specified on-time width. This is an on-time width detection means that outputs an output from the output terminal 6 when the on-time width is exceeded.

The operation of the above configuration will be explained with reference to FIGS. 2 and 3. Figure 2 shows the operation during an earthquake, and shows that even if one of the seismic waves in a) turns on the seismic sensor in b), C)
As shown in Figure 2, if there is more than the specified on-time width Ton (sz) (as shown in Figure 2, if there is only one thing that satisfies this condition, it is at the maximum peak gal value of the seismic wave). The on-time width detection means 5 in FIG. 1 outputs an output to the output terminal 6 (the seismic sensing device of the present invention operates). Therefore, the operating value of the seismic wave in the seismic sensing device of the present invention is always around a value slightly exceeding the prescribed acceleration. In addition, Figure 3 shows the operation at the time of impact, and as shown in a), the shock wave is a damped wave that initially generates the maximum peak gal value acceleration and then gradually decreases. ) The time width of the ON signal of the seismic sensor gradually decreases as shown in C).

The frequency near the maximum peak gal value in the seismic wave shown in Figure 2 a) is generally a low frequency of 1 to 4 centimeters, but the frequency of the shock wave shown in Figure 3 a) is The frequency is determined by the natural vibration determined by the installation conditions, and is generally a high frequency of 57 or higher. therefore,
The above prescribed on-time width Ton (sz) is the on-time width To at the maximum peak gal value of the seismic wave shown in Figure 2b).
np(tA), and the on-time width Tonρ(s.
), the time width of the on-signal of the seismic sensor in b) caused by the shock wave in a) in Figure 3 will be the same as the specified on-time width 7 on (sz ), the on-time width detection means 5 in FIG. 1 does not output an output (the seismic sensing device of the present invention does not operate).

Next, other embodiments of the present invention will be described.

In Fig. 4, the same parts as in Fig. 1 are given the same numbers, and 7 is a means for detecting the fluctuation state of the on/off time width, which is the on/off time of the seismic sensor l within a specified time. It monitors the width, calculates the fluctuation status of each on and off time width, or the sum of the on and off time widths, and generates an output when the fluctuation value is less than a specified fluctuation value. .

8 is an AND circuit that manually inputs two signals from the on-time width detection means 5 and the on-off time width fluctuation state detection means 7, and generates an output at the output terminal 9 only when both signals are present. be.

The operation of the stage 7 for detecting the fluctuation state of the on/off time width in the above structure will be explained with reference to FIGS. 5 and 6.

Figure 5 shows the operation at the time of an earthquake, in which the seismic waves in a) cause the on/off signals of the seismic sensor in b) to rise for a specified period of time Ts from the first rise of the on/off signal. The time width of all n ON/OFF signals until the next ON rise after c)
, d), as shown in e) and r), calculate the absolute value of the difference in each time width between on and off, and calculate their average value as the variation value Ton (ν) for on and off, respectively.
Tof f (v), and each fluctuation value is a specified fluctuation value Ton (vs) determined for on and off, respectively, Tof f (
vs) or more, the on/off time width variation detection means 7 shown in FIG. 4 generates an output. Each fluctuation value Ton (v
), Toff(v) is expressed by the formula n-1 i=1 n-1 i=1 Note that the number of on/off signals of the seismic sensor in Figure 5 b) is insufficient to detect the fluctuation state. For example, if the number of on signals is three or less, each fluctuation value Ton (v),
Tof f (v) is the specified fluctuation value Ton (vs), T
It is assumed that the on/off time width fluctuation state detection means 7 in FIG. 4 outputs an output even if it is smaller than off(vs). This is done in order to ensure that the operating value in seismic waves is around a value that slightly exceeds the specified acceleration, even with a structure like this example, and in the case where the number of ON signals is small due to impact. This is because when the ON signal itself is weak, the time width of each ON signal is short, and there is little possibility that the ON time width detection means 5 in FIG. 4 will output an output.

Figure 6 shows the behavior at the time of impact, and is basically exactly the same as the behavior in Figure 5, except that the shock waveform in a) is different from the seismic waveform shown in a) in Figure 5. ．． The basic difference between seismic waves and shock waves is that seismic waves generally fluctuate irregularly in both period and amplitude, whereas shock waves have a waveform that has the same period but whose amplitude gradually attenuates over time. Therefore, the time width of the on/off signals of the seismic sensor also becomes irregular due to earthquake vibrations, as shown in b) in Figure 5.
As shown in b), c), and d) of Fig. 6, in the case of vibration during impact, the overall trend is that the on-time width gradually decreases;
The period of off-time gradually increases, showing regularity. Therefore, the absolute value of the difference in each time width between ON and OFF becomes smaller overall as shown in e) and r) in Figure 3, and their average value, The fluctuation values Ton (v) and Tofr (v) are the specified fluctuation values Ton (vs) and Toff (v
s), the on/off time width fluctuation state detection stage 4 in FIG. 4 does not generate an output. In other words,
In such shock-induced vibrations, even if the vibration is of a long period or a strong impact, there is a risk that the on-time will become longer and the on-time width detection stage 5 in Figure 4 will output an output. However, since the on/off time width fluctuation state detecting means 4 does not detect this, no output is generated at the output terminal 3.

Note that here we used the average value to find the fluctuation value, but
The absolute value of the difference each time may be compared with the specified fluctuation value each time. Alternatively, the fluctuation value may be determined as the sum of the on and off time widths, instead of determining the fluctuation value for each on and off period. In order to prevent shock waves from operating, it is better to use a sum form rather than a constant cycle, which will reduce the fluctuation value, and even if you use an electric circuit detection method, it is better to capture only the rising edge or falling edge of the ON state. Since it is sufficient to simply set the value to 0, the overall structure becomes simple as a means for detecting the fluctuation state of the on/off time width.

Figure 7 shows an example of the internal structure of a mercury-type seismic sensor, in which mercury 12 is placed in a circular concave portion 1l at the center of a metal container lO, and a metal lid 13 is placed inside the metal container. lO
It is welded and enclosed. A cylindrical electrode 4 is provided so as to surround the mercury 12, and is taken out from the center of the lid 13 through an insulating glass 15. When this mercury-type seismic sensor is subjected to vibrations exceeding a specified strength, the mercury 12 jumps out of the central concave portion 11, and the force causes it to contact the electrode 14, and connect the metal connection terminal l6 attached to the electrode l4. An on signal is generated between it and the take-out terminal l7 attached to the lid l3. This on signal can be used, for example, to oxidize the surface of the mercury 12 to weaken its surface tension, or to inject an insulating liquid l8 into the metal container lO as shown in Figure 8 to restrict the movement of the mercury. When given a damping characteristic,
The time period during which the mercury 11 and the electrode 14 are in contact becomes longer and longer. As the on-time becomes longer, it becomes possible to more clearly distinguish between a low-frequency on-signal near where the maximum beak-gal value of the seismic wave occurs and a high-frequency on-signal at a shock wave.

Effects of the Invention As described above, the seismic sensing device of the present invention is equipped with on-time width detection means for detecting when the on-time width of the seismic sensor exceeds a specified on-time width. As long as the on-signal of the seismic sensor satisfies this condition, it will operate even if the number of times it is turned on is one.By appropriately selecting the prescribed on-time width, it will be difficult to operate due to impact, and it will not operate during earthquakes. The variation in operation due to the type of seismic waves is reduced.

In addition to the above-mentioned on-time width detection means, the seismic sensing device of the present invention also detects a fluctuation state of the on-off time width that does not produce an output with regular on-off signals of the seismic sensor that occur during an impact. Since an output signal is generated only when both of these outputs are generated, the on-time width detection means detects when the on-signal of the seismic sensor exceeds the specified on-time width at the time of impact. Even if something like this occurs, it will not result in a malfunction.

Furthermore, in the seismic sensing device of the present invention, the vibration detection mechanism of the seismic sensor has a damping characteristic that lengthens the on-signal, so it is possible to more clearly distinguish between the on-signal during an earthquake and the on-signal during an impact.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a vibration sensing device according to an embodiment of the present invention, FIGS. 2 and 3 are operational characteristic diagrams of the same device, and FIG. 4 is a block diagram of a vibration sensing device according to another embodiment of the invention. Figure, 5th
6 are operational characteristic diagrams of the same device, FIGS. 7 and 8 are cross-sectional views of the internal structure of an M-sensor according to an embodiment of the present invention, and FIG. 9 is a block diagram of a conventional seismic device. , Figures 10 to 13
The figure shows the operating characteristics of the device. 4... Seismic sensor, 5... On time width detection means, 7... On/off time width fluctuation state detection means.

Claims (3)

[Claims] (1) A seismic sensor that generates a signal that repeatedly turns on and off due to vibrations with a specified amount of acceleration, and monitors the on-time width of the seismic sensor, and checks that the on-time width exceeds the specified on-time width. A seismic sensing device comprising: on-time width detection means. (2) A seismic sensor and an on-time width detection means are used to monitor the on-time width and off-time width of the seismic sensor within a specified time, and monitor the on-time width and off-time width of the seismic sensor within a specified time, and An on/off time width fluctuation state detection means is provided which calculates the fluctuation state of the sum every time and detects that the fluctuation value is greater than or equal to a predetermined fluctuation value, and the on/off time width detection means and the on/off time width
A seismic sensing device that generates an output signal only when both outputs of an off time width fluctuation state detection means are generated. (3) Claim 1 or 3, wherein the vibration sensor has a vibration detection mechanism that detects vibrations exceeding a specified acceleration and generates a signal that repeatedly turns on and off, and has a damping characteristic that increases the duration of the on state. The seismic sensing device according to 2.