JP3383200B2 - Earthquake detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor acceleration sensor which is installed in a governor chamber or the like in a gas supply system and which detects acceleration in three axial directions, and a calculation result based on the detection signal, which is a digital signal. The present invention relates to an earthquake detecting device in which an arithmetic processing circuit capable of outputting as a signal is built in an explosion-proof case.

[0002]

2. Description of the Related Art In a gas supply system, when an earthquake occurs, it is necessary to urgently cut off the supply of gas to prevent the damage from spreading due to gas leakage and the occurrence of secondary disasters. An earthquake detection device using is provided. FIG. 8 is a block diagram showing a gas supply system using a conventional earthquake detection device. In FIG. 8, 101 is a gas manufacturing factory, 102 is a gas tank,
103 is a high pressure conduit, 104 is a governor, 105 is a governor station, 106 is an intermediate pressure conduit, 107 is a governor, 10
7a is an emergency shutoff valve, 108 is a monitoring room, 109 and 11
0 is an emergency shutoff instruction, 111 is a governor room whose interior is an explosion-proof area, and 112 is a governor. Reference numeral 130 is a force balance type sensor using an electric spring of a servo mechanism. Here, 2
In order to detect the acceleration of the axes (X and Y axes), two uniaxial type servo acceleration elements are housed in the explosion-proof container.

Reference numeral 132 is an analog signal output from the servo type acceleration sensor 130, and 140 is an analog signal 132.
It is an arithmetic processing circuit that calculates an SI value described later based on the above, and outputs an emergency shutoff signal, and is provided outside the governor chamber 111. The set value (threshold value) for determining whether or not to output the emergency cutoff signal is written in advance in the memory of the arithmetic processing circuit 140 or the like. It is configured to be able to change settings. Reference numeral 160 is a control panel provided on the exterior wall surface (non-explosion proof area) of the governor, 161 is a mechanical earthquake sensor installed in the control panel 160 and using a pendulum, and 162 is an analog signal 132 and a mechanical earthquake sensor. 1
When both the output signal of 61 and the output signal of 61 are output, the governor 1
A determination circuit for generating a shutoff signal 163 for shutting off 12; 164, a low pressure conduit; 165, a gas-supplied home; and 166, a gas-supplied factory.

By the way, in such an earthquake detecting device, there has been proposed a means of using an SI (Spectrum Intensity) value as a measure of the intensity of earthquake motion in order to detect an earthquake having a high correlation with the degree of damage to a building.
It has been implemented. This SI value is generally represented by the following equation.

[0005]

[Equation 1]

Here, k is a coefficient, Sv is a velocity response spectrum, T is a period, and h is a damping coefficient of a building. Such means are disclosed, for example, in Japanese Patent Laid-Open Nos. 62-12884, 62-12885, 62-12886, 6-214040, and 8-360.
No. 62 publication and the like. In such a means, the SI value is obtained by inputting the acceleration waveform of the seismic motion measured by the seismic sensor into the arithmetic unit that satisfies the equation of motion of the one-degree-of-freedom vibration system to obtain the speed response moment by moment, and obtaining the maximum value of the speed response. Is obtained by performing a predetermined calculation from the spectrum of, that is, the velocity response spectrum.

Next, the operation will be described. In FIG. 8, when the servo type acceleration sensor 130 detects an earthquake,
The detection signal is input as the analog signal 132 to the arithmetic processing circuit 140 in the non-explosion proof area. The arithmetic processing circuit 140 calculates the SI value, determines whether or not to output the emergency cutoff instruction based on the calculated value, and when the emergency cutoff instruction is output, the instruction is input to the determination circuit 162. On the other hand, the output of the mechanical seismic sensor 161 is also input to the determination circuit 162. Then, the determination circuit 162 generates the cutoff signal 163 when both the output signal of the arithmetic processing circuit 140 and the output signal of the mechanical seismic sensor 161 are output, and the governor 112 is cut off by this. That is, the gas supply to the low pressure conduit 164 is urgently cut off,
Prevent the spread of damage due to gas leaks and the occurrence of secondary disasters.

[0008]

Since the conventional earthquake detecting device is constructed as described above, the servo type acceleration sensor 130 is constructed by using two servo type acceleration elements which are larger and more expensive than the semiconductor acceleration sensor. However, there is a problem in that it has to be configured, becomes large and heavy, and becomes expensive. Further, since the detection signal of the servo type acceleration sensor 130 is input to the arithmetic processing circuit 140 in the non-explosion proof area as the analog signal 132, there are problems that it is vulnerable to noise and easily malfunctions. In particular, if the governor 112 is cut off due to a malfunction, from the viewpoint of ensuring safety when recovering it, it is necessary to visit the house to confirm that all gas appliances such as the home 165 are closed, There were problems such as enormous effort and cost.

If the arithmetic processing circuit 140 is to be housed in the explosion-proof container to solve this problem, it is necessary to increase the internal volume of the explosion-proof container. However, according to the explosion proof structure standard, the larger the internal volume of the explosion proof container, the longer the explosion proof clearance has to be, which further increases the size of the container. The larger the size of the container, the lower the mechanical strength of the container itself. Therefore, the thickness of the container must be increased to satisfy the pressure resistance. As a result, the entire apparatus becomes too large and heavy, and the adjustment work at the installation site becomes difficult, which is not practical.

Furthermore, the conventional seismic detection device has a calculation function only for the SI value required by the gas industry, and the seismic intensity required by the Japan Meteorological Agency and the displacement amount / speed required by the construction industry are supported. Therefore, when there is an increase in product models or changes in product delivery destinations, threshold values, measured quantities, etc., there is a problem that it cannot be dealt with promptly. Further, after the earthquake detection device is installed on the site for a certain period of time, the judgment set value (threshold value) for gas cutoff may be changed according to the ground or the building. For example, when the site is a landfill, the ground motion is likely to be large, and therefore the set value is lowered. Such a setting value change can be performed by an operator with a dip switch or the like provided in the earthquake detection device, but there is also a problem that it generally takes time.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain an earthquake detecting device which can reduce the size and weight of the entire device and can effectively prevent malfunction of the device due to noise or the like. To do.

Another object of the present invention is to obtain an earthquake detecting device which can calculate an SI value and can detect an earthquake having a high correlation with the degree of damage to a building.

A further object of the present invention is to provide an earthquake detecting device which can promptly deal with the case where the number of product models increases or the product delivery destination, each threshold value, and the measurement amount need to be changed.

A further object of the present invention is to provide an earthquake detecting device which can easily and quickly set the optimum threshold value for the ground or building on the installation site.

A further object of the present invention is to obtain an earthquake detector which can directly operate various loads such as actuators and valves by outputting a relay contact output signal.

[0016]

An earthquake detecting device according to the present invention performs a calculation process based on a semiconductor acceleration sensor for detecting acceleration in three axial directions and a detection signal of the semiconductor acceleration sensor, and outputs the calculation process result. An arithmetic processing circuit capable of outputting as a binary signal, and a metal explosion-proof case housing the semiconductor acceleration sensor and the arithmetic processing circuit are provided.
Length of screw part between the body of the explosion-proof case and the cover
And the number of threads and pressure-resistant packing of the lead-out part of the electric wire.
It has a structure that satisfies the explosion proof structural standards for electrical machinery .

In the earthquake detecting device according to the present invention, the arithmetic processing circuit is configured to calculate the SI value.

In the earthquake detecting device according to the present invention, the arithmetic processing circuit calculates at least the SI value, the seismic intensity, the acceleration, the displacement amount, and the velocity, and selects a plurality of calculated values from the calculated values. It is equipped with means.

The earthquake detecting apparatus according to the present invention is configured to perform arithmetic processing based on an arbitrary plurality of calculated values and output the arithmetic processing result as a binary signal.

The seismic detection apparatus according to the present invention comprises a connection terminal for connecting a portable setting device for giving a setting signal for selecting the calculated value to the calculated value selecting means.

In the earthquake detecting device according to the present invention, the arithmetic processing circuit includes the relay contact output means for outputting the arithmetic processing result as a relay contact output signal.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. 1 is a block diagram showing a gas supply system using an earthquake detection device according to Embodiment 1 of the present invention, FIG. 2 is a perspective view showing the earthquake detection device, and FIG. 3 is A in FIG.
-A sectional view, FIG. 4 is a plan view showing a state where the cover of the earthquake detection device is removed, and FIG. 5 is a circuit configuration diagram of the earthquake detection device. First, a schematic configuration of a gas supply system using the present invention will be described. In FIG. 1, 1 is a gas manufacturing plant with an explosion-proof zone, 2 is a gas tank, 3 is a high-pressure conduit, 4 is a governor, 5 is a governor station with an explosion-proof area, 6 is a medium-pressure conduit, 7 is a governor, and 7a is Emergency shutoff valve, 8 is monitoring room, 9
Reference numerals 10 and 10 designate an emergency shutoff instruction, 11 a governor room which is an explosion-proof area, and 12 a governor having an emergency shutoff function.

Reference numeral 20 is an explosion-proof case, which will be described later, 30 is a semiconductor acceleration sensor, which will be described later, capable of measuring three axes (X, Y, Z axes), 40 is an arithmetic processing circuit, which will be described later, and 57 is an output from the arithmetic processing circuit 40. Digital signal (binary signal), 60
Is a control panel installed on the exterior wall of the governor (non-explosion proof area). Reference numeral 61 is a mechanical seismic sensor installed in the control panel 60 and utilizing a pendulum, and 62 is a digital signal 57.
And the output signal of the mechanical seismic sensor 61 are both output, a determination circuit that generates a shutoff signal 63 that shuts off the governor 12, 64 is a low pressure conduit, 65 is a gas-supplied home, 66 is gas It is a factory supplied.

Next, the earthquake detector will be described in more detail. 2 to 4, 20 is an O-ring 21.
It is an explosion-proof case which is formed of a metal such as aluminum so as to satisfy a predetermined withstand pressure, and which has a cover 20a which can be opened and closed via a wire and a wire lead-out hole (a wire lead-out portion) 20b. This explosion-proof case is manufactured so as to meet the explosion-proof structure standard for electric machinery and equipment (Ministry of Labor). That is, the length and number of threads of the explosion-proof case 20 and the cover 20a, the pressure-proof packing (described later) of the wire lead-out hole 20b, and the like satisfy the above-mentioned standards.

Reference numeral 24 is a shielded wire (electric wire) which is a collection of various wirings described later, 25 is a pressure-proof packing (electric wire lead-out portion) made of, for example, butyl rubber, 26 is a compression bolt (electric wire lead-out portion) for compressing the pressure-proof packing 25, 27 is a lock nut (electric wire lead-out portion) for fixing the compression bolt 26.
That is, the shield wire 24 is inserted through the wire lead-out hole 23,
By providing the pressure-resistant packing 25, the compression bolt 26, and the lock nut 27, it is possible to ensure the sealing property and pressure resistance of the relevant portion. The length of the pressure-resistant packing 25 after compression satisfies the above standard.

Reference numeral 30 denotes a semiconductor acceleration sensor, and for example, a sensor utilizing a change in electrostatic capacity and a signal processing circuit thereof described in Japanese Patent Laid-Open No. 9-43068 can be used. As mentioned in the section of the prior art of the publication,
A plurality of pairs of electrostatic capacitance elements are provided by mounting electrodes on the respective opposing surfaces of the fixed substrate and the flexible substrate, and an XY plane parallel to the substrate surface is set, and a Z-axis orthogonal to the XY plane is set. X, Y,
The change in acceleration in the Z-axis three-dimensional direction is detected for each X-, Y-, and Z-axis direction component based on the change in capacitance between a plurality of pairs of capacitance elements. The capacitance difference between the capacitance elements C21 and C23 (C21-C23) is the output for the acceleration in the X-axis direction, and the capacitance difference between the capacitance elements C22 and C24 is the output for the acceleration in the Y-axis direction. The capacitance difference (C22-C24) and the output with respect to the acceleration in the Z-axis direction can be detected as the capacitance C25 of the capacitance element C25 or C21 + C22 + C23 + C24. The semiconductor acceleration sensor 30 is not limited to the capacitance type acceleration sensor, and for example, a piezoresistive type or a piezoelectric type acceleration sensor may be used.

Reference numeral 31 is a support member and 32 is a CPU.
A board, 33 is a power board, 34 is a terminal block, 35 is a guard, and 36 is a loader connection terminal (connection terminal) for connecting a portable setting device (not shown) to a loader interface 55 described later.

Next, the circuit configuration of the earthquake detection device is shown in FIG.
It will be described based on. In FIG. 5, 40 is the above-mentioned C
An arithmetic processing circuit formed on the PU board 32 or the like, 41 is a control unit, 42 is an SI value calculated by the SI value calculation unit 42a, a seismic intensity calculated by the seismic intensity calculation unit 42b, and an acceleration calculation unit 42c. Acceleration and
It is a calculation value selection unit that selects an arbitrary plurality of calculation values from the displacement amounts calculated by the displacement amount calculation unit 42d and the calculated values of the speed calculated by the speed calculation unit 42e. That is, the calculated value selection means 42 is to provide an optimum setting at the installation site by appropriately combining various calculation functions as necessary. Four
3 is a determination unit that determines whether or not to output an emergency shutoff instruction based on the calculated value, and 44 is a memory, for example,
A threshold value for judgment required in the judgment means 43 is recorded in advance. The cutoff instruction is output to the outside via a relay interface 53 described later. For example, when the determination means 43 determines to shut off, an electromagnet inside the relay is excited by a relay drive circuit (not shown), and the normally open contact is closed, so that the output to the outside is performed.

Reference numeral 45 is a real time clock, 46 is a sensor interface, 47 is a temperature sensor for correction, 48 is a reference voltage, 49 is a power supply circuit, and 50 is a backup circuit. Reference numeral 51 is a digital output interface, and 52 is a digital input interface. Reference numeral 53 is a relay interface (relay contact output means) that outputs the calculation processing result as a relay contact output signal instead of a digital signal.
The relay interface 53 is configured to be able to directly connect a circuit such as DC 24 V or AC 100 V, and thus can directly operate various loads such as an actuator, a valve, and a large relay. You can do it. The relay interface 53 and a contact side circuit (not shown) are electrically separated from each other. The relay interface 53
Can be connected not only to relays, but also to separate insulated electrical parts such as photocouplers and photomos relays.

Reference numeral 54 is an analog output interface. Reference numeral 55 denotes a loader interface for connecting a portable setting device (not shown) which gives a setting signal for selecting the calculated value to the calculated value selecting means 42, and includes the loader connection terminal 36 described above. A setting means using such a portable setting device is disclosed in, for example, Japanese Patent No. 2523.
The means disclosed in Japanese Patent No. 053 can be used. The wiring from the external power supply to the power supply circuit 49 and the wiring of each of the interfaces 51, 52, 53, 54 are drawn out of the explosion-proof case 20 by the shield wire 24 described above.

Next, the operation will be described. 5 and 1
In, when the semiconductor acceleration sensor 30 detects an earthquake, the detection signal is input to the control unit 41 via the sensor interface 46. In this case, since the semiconductor acceleration sensor 30 can measure three axes (X, Y, Z axes), more accurate vibration measurement of seismic motion can be performed. Particularly in a direct earthquake, since the Z-axis (vertical) direction vibrates first, more important measurement information can be obtained. In the control unit 41,
The SI value, seismic intensity, and the like that have been selected in advance by the calculated value selection unit 42 are calculated by the respective calculation units 42a to 42e. The setting signal that causes the calculated value selecting means 42 to select the calculated value is the threshold value most suitable for the installation site when the worker connects the portable setting device (not shown) to the loader connection terminal 36 at the installation site and communicates with the loader. Can be set easily and quickly.

The determination means 43 determines whether or not to output the emergency cutoff instruction based on the calculated value. When the emergency cutoff instruction is output, for example, the determination circuit of the control panel 60 from the digital output interface 51. A digital signal 57 is output to 62. Therefore, the shielded wire 2
Even if 4 is routed from the governor chamber 11 to the control panel 60, it is resistant to noise and does not malfunction. In this case, for example,
More reliable detection can be expected by configuring so that the shutoff instruction signal is output when both the SI value and the seismic intensity exceed a predetermined value.

Then, the digital signal 57 is input to the determination circuit 62 of the control panel 60, as shown in FIG.
On the other hand, the output of the mechanical earthquake sensor 61 is also input to the determination circuit 62. In the decision circuit 62, these digital signals 57
When both the output signal of the mechanical seismic sensor 61 and the output signal of the mechanical seismic sensor 61 are output, the shutoff signal 63 is generated and the governor 12 is shut off. That is, the supply of gas to the low-pressure conduit 64 is urgently shut off, and the damage caused by gas leakage and the secondary disaster can be effectively prevented.
In the determination circuit 62, when it is desired to output the cutoff signal 63 at an early stage in order to ensure safety in the event of an earthquake, it may be determined as the logical sum of the digital signal 57 and the output signal of the mechanical earthquake sensor 61. it can.

Further, since the relay interface 53 outputs the arithmetic processing result as a relay contact output signal instead of a digital signal, if this is connected to a circuit of, for example, DC 24 V or AC 100 V, an actuator, a valve, Various loads such as large relays can be operated directly. In this case, since the relay interface 53 and the contact side circuit (not shown) are electrically separated from each other, the noise characteristic is further improved as compared with the digital signal 57 output from the digital output interface 51.

As described above, according to the first embodiment, since the small semiconductor acceleration sensor 30 is used, the arithmetic processing circuit 40 can also be incorporated in the explosion-proof case 20,
It is possible to reduce the size and weight of the entire device and to easily handle the device. Further, since the emergency shutoff instruction from the arithmetic processing circuit 40 is output as the digital signal 57, the reliability against noise is significantly improved, and the effect of effectively preventing the malfunction of the device can be obtained.

Furthermore, since the semiconductor acceleration sensor 30 can measure three axes (X, Y, Z axes), more accurate vibration measurement of seismic motion can be performed, and in particular, a direct type earthquake in which the Z axis (vertical) direction first vibrates. Then, the effect that more important measurement information can be obtained is obtained. In addition to the SI value required by the gas industry, the seismic intensity required by the Japan Meteorological Agency and the displacement amount / velocity required by the construction industry can be arbitrarily calculated by the calculated value selection means 42. Even if the delivery destination, each threshold value, the measured amount, etc. need to be changed, the effect of easily and flexibly responding can be obtained. Furthermore, for example, by configuring so that an alarm signal is output when both the SI value and the seismic intensity exceed a predetermined value, an effect that more reliable detection can be expected can be obtained.

The setting signal for selecting the calculated value by the calculated value selecting means 42 is connected to the loader connection terminal 36 by a worker by a portable setting device (not shown) at the installation site, and the loader communicates with the portable setting device. The effect that the optimum threshold value for the ground or building can be set easily and quickly is obtained. Further, since the relay interface 53 outputs the calculation processing result as a relay contact output signal instead of a digital signal, it is possible to directly operate various loads such as an actuator, a valve, and a large relay, and also improve noise characteristics. be able to.

In the first embodiment, the arithmetic processing circuit 40 has been described as being capable of calculating not only the SI value but also the seismic intensity, acceleration, etc. However, when only the SI value is required, only the SI value is calculated. It may be configured so as to be limited. By omitting unnecessary functions in this way, an effect that a highly reliable earthquake detection device can be manufactured at a lower cost can be obtained. Further, although the arithmetic processing circuit 40 has been described as being capable of calculating the SI value, seismic intensity, acceleration, displacement amount, speed, etc., it is not limited to this and may be configured to be able to calculate other physical quantities. In this case, there is an effect that the range of application of the earthquake detection device can be further expanded.

Embodiment 2. 6 is a block diagram showing a gas supply system using an earthquake detector according to Embodiment 2 of the present invention, and FIG. 7 is a vertical sectional view showing the earthquake detector. The same members as or members corresponding to those in the first embodiment are designated by the same reference numerals,
The description is omitted. 6 and 7, the earthquake detection device includes a semiconductor acceleration sensor 30 that detects acceleration in three axial directions, a mechanical earthquake sensor 70 that detects vibration and outputs a digital signal 72, and a detection of the semiconductor acceleration sensor 30. An arithmetic processing circuit 40 capable of performing arithmetic processing based on the signal and the detection signal of the mechanical seismic sensor 70 and outputting the arithmetic processing result as a binary signal, an openable / closable cover 20a and an electric wire deriving hole 20b which is an electric wire deriving portion. And an explosion-proof case 20 accommodating the semiconductor acceleration sensor 30, the mechanical seismic sensor 70, and the arithmetic processing circuit 40.

If the mechanical seismic sensor 70 is constructed so that the detection signal can be output as a binary signal, for example,
A sensor disclosed in Japanese Patent Laid-Open No. 3-219517,
The sensor disclosed in Japanese Utility Model Laid-Open No. 3-13642 can be used. Here, in the sensor disclosed in Japanese Patent Laid-Open No. 3-219517, the vibration system of the seismograph is composed of a fundamental vibration system by a spring supported by the surface tension of mercury that supports the bottom portion of mercury in droplet form, and a vibration system of mercury. And a dynamic vibration system. Further, the sensor disclosed in Japanese Utility Model Laid-Open No. 3-13642 is a seismic sensor using mercury, which comprises a first electrode and a second electrode facing each other and an insulator separating them, and A spherical shell that contains mercury and has a center of gravity located between the center and the second electrode, and a spherical shell housing that is a spherical electrode that is in partial mechanical contact with the second electrode of the spherical shell; The first electrode of the spherical shell is provided with a point contact type electrode that makes mechanical contact.

The mechanical seismic sensor 70 is, for example,
A configuration in which a switch is turned on / off by vibration of a vibrator can also be used. 74 is a predetermined digital signal 57
Shutoff signal 63 that shuts off the governor 12 when is output
Is a determination circuit for generating. The arithmetic processing circuit 40
Is equipped with a sensor interface (not shown) that processes input / output with the mechanical seismic sensor 70. Other configurations are similar to those in the case of the above-described first embodiment, and therefore description thereof will be omitted.

Next, the operation will be described. In FIG. 6, when the semiconductor acceleration sensor 30 detects an earthquake, the detection signal is input to the arithmetic processing circuit 40. in this case,
Since the semiconductor acceleration sensor 30 can measure three axes (X, Y, Z axes), more accurate vibration measurement of seismic motion can be performed. Particularly in a direct earthquake, since the Z-axis (vertical) direction vibrates first, more important measurement information can be obtained. On the other hand, when the mechanical earthquake sensor 70 detects an earthquake, the detection signal is input to the arithmetic processing circuit 40 as a digital signal 72. The arithmetic processing circuit 40 determines as a logical product when both the detection signal of the semiconductor acceleration sensor 30 and the digital signal 72 of the mechanical seismic sensor 70 are output,
The digital signal 57 is output to the determination circuit 74. As a result, even if the shield wire is routed from the governor chamber 11 to the control panel 60, the shield wire is resistant to noise and does not malfunction. The determination circuit 74 receives the digital signal 57 and receives the cutoff signal 6
3 is generated and the governor 12 is shut off. That is, the supply of gas to the low-pressure conduit 64 is urgently shut off, and the damage caused by gas leakage and the secondary disaster can be effectively prevented.

As described above, according to the second embodiment, an earthquake can be detected / judged based on the detection signals of the semiconductor acceleration sensor 30 and the mechanical earthquake sensor 70, which are two types of sensors having different detection principles. There is no fear of malfunction, and the effect that highly reliable earthquake detection can be obtained is obtained.
In particular, since the detection signal of the mechanical seismic sensor 70 and the emergency shutoff instruction signal from the arithmetic processing circuit 40 are output as digital signals, the reliability against noise is significantly improved, and the malfunction of the device can be effectively prevented. can get.

[0044]

As described above, according to the present invention, the semiconductor acceleration sensor for detecting the acceleration in the three-axis directions and the arithmetic processing based on the detection signal of the semiconductor acceleration sensor are performed, and the arithmetic processing result is binarized. An arithmetic processing circuit capable of outputting as a signal, a semiconductor acceleration sensor accommodating the semiconductor acceleration sensor and the arithmetic processing circuit, and an arithmetic processing circuit are accommodated.
And a metal explosion-proof case,
The length and number of threads between the body and the cover and
The pressure-proof packing at the lead-out part of the electric wire
Sealed against noise because it is constructed with a structure that satisfies the case
Due to the effect as a cable and the increase in the internal volume of the explosion-proof case
The effect of preventing thickening of the explosion-proof case
Sometimes played. And metal protection that has a noise shield function
Convert to a binary signal inside the explosion case and then send it out
Therefore, it also has the effect of being resistant to noise.
It is a thing. Since it is configured with the explosion-proof case, the arithmetic processing circuit as well as the semiconductor acceleration sensor can be built in the explosion-proof case, and the overall size and weight of the device can be reduced and the handling can be facilitated. Also, since the emergency shutoff instruction from the arithmetic processing circuit is output as a binary signal,
The reliability against noise is significantly improved, and the malfunction of the device can be effectively prevented. Furthermore, since the semiconductor acceleration sensor can perform 3-axis measurement, more accurate vibration measurement of seismic motion can be performed, and more important measurement information can be obtained particularly in the case of a direct earthquake in which the Z-axis (vertical) direction first vibrates. effective.

According to the present invention, since the arithmetic processing circuit is configured to calculate the SI value, there is an effect that earthquake detection having a high correlation with the degree of damage to the building can be performed.

According to the present invention, the arithmetic processing circuit includes at least the calculated value selecting means for calculating the SI value, the seismic intensity, the acceleration, the displacement amount, and the speed, and selecting an arbitrary plurality of calculated values from the calculated values. Since it is configured, the SI value required by the gas industry, the seismic intensity required by the Japan Meteorological Agency, and the displacement amount and speed required by the construction industry can be calculated arbitrarily. Therefore, even when the number of product models increases or the product delivery destination, each threshold value, the measured amount, or the like needs to be changed, there is an effect that it can be easily and flexibly dealt with.

According to the present invention, the arithmetic processing is performed based on an arbitrary plurality of calculated values, and the arithmetic processing result is output as a binary signal. Therefore, for example, both the SI value and the seismic intensity are predetermined. By outputting an alarm signal when the value exceeds the value, more reliable detection can be expected.

According to the present invention, the portable terminal is provided with the connection terminal for connecting the portable value setting device for giving the setting signal for selecting the calculated value to the calculated value selecting means. By connecting the loader to the connection terminal and communicating with the loader, it is possible to easily and quickly set the optimum threshold value for the ground or building at the installation site.

According to the present invention, since the arithmetic processing circuit is provided with the relay contact output means for outputting the arithmetic processing result as the relay contact output signal, an actuator, a valve, or a large-sized one can be produced by the output relay contact output signal. Various loads such as a relay can be directly operated, and noise characteristics can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a gas supply system using an earthquake detection device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an earthquake detection device.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a plan view showing a state where a cover of the earthquake detection device is removed.

FIG. 5 is a circuit configuration diagram of the earthquake detection device.

FIG. 6 is a block diagram showing a gas supply system using an earthquake detection device according to a second embodiment of the present invention.

FIG. 7 is a vertical sectional view showing an earthquake detection device.

FIG. 8 is a block diagram showing a gas supply system using a conventional earthquake detection device.

[Explanation of symbols]

20 explosion-proof case 20a cover 20b Electric wire lead-out hole (electric wire lead-out part) 24 Shield wire (electric wire) 25 Pressure-resistant packing (electric wire lead-out part) 26 Compression bolt (electric wire lead-out part) 27 Lock nut (electric wire lead-out part) 30 Semiconductor acceleration sensor 36 Loader connection terminal (connection terminal) 40 arithmetic processing circuit 42 Calculated value selection means 53 Relay interface (relay contact output means) 57 digital signals (binary signals)

─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takayuki Akimoto 2-12-19 Shibuya, Shibuya-ku, Tokyo Yamatake Honeywell Co., Ltd. ) Inventor Kenichi Koganemaru 5-16-5 Sakuradai, Nerima-ku, Tokyo (56) References JP-A-8-77475 (JP, A) JP-A-7-225242 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) G01V 1/00 G01H 1/00 G01P 15/00 G01V 1/16 G01V 1/28

Claims (6)

(57) [Claims] 1. A semiconductor acceleration sensor for detecting acceleration in three-axis directions, an arithmetic processing circuit capable of performing arithmetic processing based on a detection signal of the semiconductor acceleration sensor, and outputting the arithmetic processing result as a binary signal; A metal explosion-proof case for accommodating the semiconductor acceleration sensor and the arithmetic processing circuit, which has a possible cover and a wire lead-out portion.
The length of the screw between the main body of the explosion case and the cover and
The number of threads and the pressure-proof packing at
An earthquake detection device that has a structure that satisfies the explosion proof structural standards for pneumatic machinery . 2. The earthquake detection device according to claim 1, wherein the arithmetic processing circuit calculates an SI value. 3. The arithmetic processing circuit comprises at least a calculated value selecting means for calculating an SI value, a seismic intensity, an acceleration, a displacement amount, and a speed, and selecting an arbitrary plurality of calculated values from the calculated values. The earthquake detection device according to claim 1. 4. The earthquake detection device according to claim 3, wherein arithmetic processing is performed based on an arbitrary plurality of calculated values, and the arithmetic processing result is output as a binary signal. 5. The seismic detection device according to claim 3, further comprising a connection terminal for connecting a portable setting device that gives a setting signal for selecting the calculated value to the calculated value selecting means. 6. The seismic detection according to any one of claims 1 to 5, wherein the arithmetic processing circuit includes relay contact output means for outputting the arithmetic processing result as a relay contact output signal. apparatus.