JP2014041031A - Earthquake detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earthquake detector which achieves the protection of an acceleration sensor from a high frequency vibration applied during installation of the earthquake detector on a floor surface, and the improvement in handleability during the installation.SOLUTION: An earthquake detector which includes an acceleration sensor incorporated in a container and which is used with the container fixed on a floor surface includes: a lid body sealing the container; a mounting plate which is provided inside the container and on which the acceleration sensor is mounted; an inner bottom face projection formed on an inner bottom face of the container; an elastic member which is fixed to the inner bottom face projection and which is provided between the inner bottom face projection and the mounting plate; and a fixture fixing the mounting plate to the inner bottom face projection.

Description

  The present invention relates to an earthquake detection device that can protect an acceleration sensor housed in a container from an impact during installation.

The earthquake detection device is used for applications such as detecting a shake or an impact caused by an earthquake and generating an earthquake detection signal, for example, an emergency operation of a gas shut-off valve to prevent a secondary disaster due to outflow of gas.
This type of earthquake detection device is, for example, as in Patent Document 1, exclusively a sealed container made of metal such as aluminum (
The acceleration sensor and its drive circuit are housed inside the exposure case. The acceleration sensor for earthquake detection has a resonance point of the vibrator at a relatively high frequency (for example, 1 kHz), and can also be broken by an impact when an earthquake detection device is installed on a floor surface that has been hit with concrete. There is. Therefore, in order to protect the acceleration sensor housed in the container from unintentionally applied high-frequency vibration, a vibration absorbing member made of an elastic body is formed in a recess formed on the bottom surface of the earthquake detection device that forms a contact surface with the floor surface. Has been disclosed (see Patent Document 2, for example).
Japanese Patent Laid-Open No. 11-118936 JP 2006-194741 A

  According to the earthquake detection device of Patent Document 2 described above, as shown in FIG. 6, the acceleration sensor 23 is already fixed to the inner bottom surface 25 of the container at the stage of installation on the floor surface. Therefore, in the process of inserting a vibration absorbing member (not shown) between the inner bottom surface 25 and the floor surface of the container and installing it on the floor surface with a fixing bolt, the container lightly hits a portion where the vibration absorbing member is not inserted. If an accident such as this occurs, an impact applied to the container is directly transmitted to the acceleration sensor, which may cause the acceleration sensor 23 to be destroyed.

  If the acceleration sensor fails, the seismic detection device shows a larger value than the actual seismic intensity at the time of the earthquake, or the initial value drifts, making it impossible to record large seismic waves. Cannot be fulfilled.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an earthquake detection device that protects an acceleration sensor from high-frequency vibration applied during installation on the floor, and further improves handling at installation. It is to provide.

  In order to achieve the above object, an earthquake detection apparatus according to the present invention is an earthquake detection apparatus that includes an acceleration sensor incorporated in a container and is used by fixing the container to a floor surface, and seals the container. A cover body, a mounting plate provided inside the container, on which the acceleration sensor is placed, an inner bottom protrusion formed on the inner bottom surface of the container, and fixed to the inner bottom protrusion, An earthquake detection apparatus comprising: an elastic member provided between the inner bottom surface protrusion and the mounting plate; and a fixture for fixing the mounting plate to the inner bottom surface protrusion.

  According to the present invention, the acceleration sensor can be protected from high-frequency vibrations with a simple configuration, and the handleability during installation can be improved.

Hereinafter, an earthquake detection apparatus according to an embodiment of the present invention will be described with reference to the drawings.
In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(First embodiment)
As shown in FIG. 1 which is a schematic configuration diagram of the earthquake detection apparatus according to the first embodiment of the present invention, for example, an acceleration is applied to a cylindrical container 1 made of aluminum having an outer diameter of about 10 cm and a height of about 10 cm. The sensor and its drive circuit are accommodated, and the upper part thereof is watertightly sealed by the lid 2.

More specifically, description will be made with reference to FIG. 2 which is a top view of the earthquake detection apparatus and FIG. 3A which is a longitudinal sectional view showing the internal structure.
The container 1 has a structure in which three fixing flanges 1a projecting laterally are provided on the peripheral surface of the bottom portion, and a joint pipe 1b for pulling out a cable is formed on the peripheral wall surface. A disc-shaped lid 2 is screwed to the upper opening end of the container 1 through an O-ring as a packing member in a watertight manner. The container 1 and the lid 2 are paired. Therefore, it constitutes an exposure case that meets the explosion-proof standards. The acceleration sensor 3 incorporated in the inside of the container 1 includes an X-axis direction acceleration sensor 3a, a Y-axis direction acceleration sensor 3b, and a Z-axis direction acceleration sensor 3c. Each acceleration component in the axis, Y axis, and Z axis directions can be detected. A substrate 4 is incorporated inside the container 1 and is electrically connected to an external device (not shown) by a cable laid through the joint pipe 1b. Further, the fixing flange 1a is provided with a through hole 1c that passes through the upper and lower surfaces thereof and through which a fixing bolt (not shown) to the floor is inserted. The bottom surfaces of the three flanges 1a are provided at the same position on the same plane.

  Basically, in the earthquake detection apparatus configured as described above, the feature of this embodiment is that the mounting plate 11 on which the acceleration sensor 3 is mounted is an elastic member provided on the inner bottom surface 5 of the container 1. The coil spring 14 is connected to the inner bottom surface 5 of the container 1 through a coil spring 14. An inner bottom surface protrusion 6 formed integrally with the inner bottom surface 5 is provided on the inner bottom surface 5 of the container 1 and has, for example, a cylindrical shape. The inner cavity of the coil spring 14 is inserted into the inner bottom projection 6 and the lower end of the coil spring 14 is fixed. The upper end of the coil spring 14 is joined to the back surface of the mounting plate 11.

  An inner hole 7 having a screw thread is formed in the cylindrical inner bottom protrusion portion 6. By passing the mounting screw 8 through the screw insertion hole 9 provided in the mounting plate 11 and tightening the mounting screw 8 with respect to the inner hole 7, the coil spring 14 is gradually deformed in the contracting direction. As shown in (b), the mounting screw 8 can be tightened to a position where the mounting plate 11 and the upper end of the inner bottom surface projection 6 are in contact with each other. Here, as shown in FIG. 4A, the inner bottom surface protrusion 6 may be formed by recessing the outer periphery of the inner bottom surface protrusion 6, or as shown in FIG. You may form so that only the part of the inner bottom face projection part 6 may raise.

  Next, a method for installing the earthquake detection device on the floor will be described with reference to FIGS.

  First, at the stage of placing the earthquake detection device on the floor surface, the mounting screw 8 is not tightened with respect to the inner hole 7, and the mounting plate 11 and the inner bottom projection 6 are as shown in FIG. A non-contact state is provided with a margin of a predetermined distance H between the upper end of each of the two. Here, in order to prevent frictional force between the screw insertion hole 9 and the mounting screw 8 from acting and restricting the expansion and contraction of the coil spring 14, the diameter of the nominal length portion of the mounting screw 8 is set to the screw insertion. It is designed to be smaller than the diameter of the hole 9.

  By configuring as described above, the shock is absorbed by the coil spring 14 expanding and contracting within the range of the interval H against the unintentional high-frequency vibration that is applied when the earthquake detector is placed on the floor surface. Therefore, the earthquake detection device can be placed on the floor without transmitting vibration to the acceleration sensor 3.

  Next, the seismic detection device is fixed to the floor surface by inserting and tightening a fixing bolt (not shown) into a through hole 1c provided in the fixing flange 1a. Even at this stage, the mounting plate 11 and the upper end of the inner bottom surface protrusion 6 are in a state having a margin by a distance H. Therefore, even when the fixing bolt is tightened, the impact is absorbed by the coil spring 14 extending and contracting within the interval H even against high frequency vibration that has been applied to the container 1 unintentionally.

  After the fixing of the earthquake detection device to the floor surface is completed, as shown in FIG. 3 (b), the mounting screw 8 is inserted into the inner hole 7 until the mounting plate 11 comes into contact with the upper end of the inner bottom surface protrusion 6. And tighten. A mounting screw operation hole 10 for inserting a tool such as a screwdriver is formed in the substrate 4, and the mounting screw 8 is tightened even when the substrate 4 is fixed to the container 1. It is possible.

  Thus, after the earthquake detection device and the floor surface are fixed, the attachment plate 11 is fixed to the container 1 for the first time as shown in FIG. As a result, the vibration caused by the occurrence of the earthquake can be transmitted to the acceleration sensor 3, so that the function as the earthquake detection device can finally be performed normally. In other words, until the mounting screw 8 is completely tightened, the high-frequency vibration that is unintentionally applied to the container 1 is effectively absorbed by the coil spring 14, and such vibration is not transmitted to the acceleration sensor.

  As described above, until the earthquake detection device and the floor are completely fixed, the acceleration sensor 3 and the container 1 are not fixed via the elastic member, that is, in a non-contact state. Thus, it is possible to effectively eliminate high-frequency vibration applied to the acceleration sensor during mounting, and to prevent the acceleration sensor from being damaged. Then, after the installation on the floor surface is completed, the mounting plate 11 on which the acceleration sensor 3 is installed and the inner bottom projection 6 of the container 1 in which the acceleration sensor 3 is contained are fixed, whereby the installation work is performed. The seismic detection device can function normally without incurring problems with the acceleration sensor.

(Other embodiments)
The present invention is not limited to the embodiment described above. In the earthquake detection device according to the above-described embodiment, the coil spring 14 is used as the elastic member. However, the present invention is not limited to this. For example, a spring component such as a leaf spring, an elastic body such as rubber or sponge, a shock absorber Any member that can be elastically deformed by applying a force, such as a device that attenuates vibrations or the like, may be used.

  In the above-described embodiment, the coil spring 14 and the mounting screw 8 as elastic members are provided at only one place, but may be provided at a plurality of places. In the above-described embodiment, the mounting screw 8 is tightened with the lid 2 removed. However, the mounting screw is inserted from the top of the lid 2 using a mounting screw having a length that penetrates to the lid 2. If it is configured to tighten, the mounting screw 8 can be tightened even with the lid 2 attached to the container 1.

  Furthermore, as shown in FIG. 5, a snap fit mechanism may be provided instead of the mounting screw 8. In the present embodiment, the engaging piece 12 is formed integrally with the mounting plate, and the engaging portion 13 is provided on the inner surface of the peripheral wall 6a formed around the inner bottom surface protruding portion 6, and these are engaged. If it is made to fix by making it, the effect similar to the above-mentioned embodiment is acquired. In the present embodiment, as a method of fixing the mounting plate 11 and the inner bottom projection 6, for example, a thin rod member (not shown) is inserted from the mounting screw operation hole 10 and the mounting plate 11 is pressed downward. In this way, it is sufficient to lock and fix. Further, the position where the locking portion 13 is provided may be the outer peripheral surface of the inner bottom surface protruding portion 6 and is determined as appropriate and is not limited to the above-described embodiment.

  As described above, the present invention has been described by the embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention, and the scope of the present invention is not deviated. It goes without saying that various embodiments and the like are included.

The figure showing the outline appearance of the earthquake detection device concerning one embodiment of the present invention. FIG. 2 is a top view showing the internal structure of the earthquake detection device shown in FIG. FIG. 2 is a longitudinal sectional view showing an internal structure of the earthquake detection device shown in FIG. 1 before and after tightening a mounting screw. The figure which showed other embodiment of the inner bottom face projection part. The longitudinal cross-sectional view which showed the internal structure of the earthquake detection apparatus based on other embodiment of this invention The longitudinal cross-sectional view which showed the internal structure of the conventional earthquake detection apparatus.

1, 21
Container 1a Flange 1b Joint tube 1c Through hole 2, 22 Lid 3, 23 Acceleration sensor 3a X-axis direction acceleration sensor 3b Y-axis direction acceleration sensor 3c Z-axis direction acceleration sensor 4, 24 Substrate 5, 25 Inner bottom surface 6 Inner bottom surface protrusion Part 6a Perimeter wall 7 Inner hole 8, 28 Mounting screw 9 Screw insertion hole
DESCRIPTION OF SYMBOLS 10 Mounting screw operation hole 11, 31 Mounting plate 12 Engagement piece 13 Locking part 14 Coil spring

Claims (5)

An earthquake detection device comprising an acceleration sensor incorporated in a container and used by fixing the container to a floor surface,
A lid for sealing the container;
A mounting plate provided inside the container and on which the acceleration sensor is placed;
An inner bottom protrusion formed on the inner bottom of the container;
An elastic member fixed to the inner bottom protrusion, and provided between the inner bottom protrusion and the mounting plate;
An earthquake detection apparatus comprising: a fixing tool for fixing the mounting plate to the inner bottom surface protrusion.   2. The earthquake detection device according to claim 1, wherein the mounting plate and the inner bottom surface protrusion are in a non-contact state until the mounting plate and the inner bottom surface protrusion are fixed by the fixture. An earthquake detection apparatus, characterized in that it is connected via a member. The fixture is a screw member,
The earthquake detection device according to claim 2, wherein the mounting plate is fixed to the inner bottom surface protrusion by the screw member. The fixture is a snap-fit mechanism,
The engagement plate integrally formed on the mounting plate and an engaging portion formed on a part of the inner bottom surface are engaged to fix the mounting plate to the inner bottom protrusion. 2. The earthquake detection apparatus according to 2. A circuit board is provided inside the container,
The earthquake detection device according to claim 3 or 4, wherein a hole for inserting a member necessary for fixing the mounting plate to the inner bottom surface protrusion by the fixing tool is formed in the circuit board.