JPH07229786A - Seismic element - Google Patents

Abstract

PURPOSE:To obtain a seismic element which has a small size and has a stable performance. CONSTITUTION:The contact member 8 of a seismic element is made of a conductive material such as phosphor bronze, has plural vane form members 8A having a flexible elasticity, whose contact parts are arranged almost on a circle to the center of the contact member 8, and they can come into contact with conductive balls housed in the seismic element. When this contact member 8 is fixed in the seiscope element by a welding or the like, the periphery 8D of a through hole 8B for fixing is distorted by the heat. However, by providing slits 8C almost all the periphery around the through hole 8B, the distortion generated to the periphery 8D is not transmitted to the outer side of the slits 8C, and the positional relation of the vane form members 8A at each product is not varied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is installed in, for example, a microcomputer meter for city gas, propane gas, or the like, or installed in a control device for an oil heater, a gas combustion device, an electric device, or the like to detect a vibration such as an earthquake. The present invention relates to a seismic sensing element used in a seismic sensor that sends a detection signal to the microcomputer meter and the control device.

[0002]

2. Description of the Related Art Conventionally, as an acceleration responsive switch of this type, there is, for example, Japanese Patent Application No. 4-272387 entitled "Seismic Sensing Device". As shown in FIG. 5, a vibration-sensing element 101 used in this vibration-sensing device is a contact member 10 fixed in a metallic closed container 102 by a glass 103 so as to be electrically insulated from the container.
4 and the conductive ball 105 is swingably housed,
When the conductive sphere swings due to vibration, it comes into contact with the electrode, thereby electrically short-circuiting the container and the electrode to generate a detection signal.

In recent years, such a seismic sensor has been attached to a gas flow meter such as city gas or propane gas installed in each home so that not only the flow rate is recorded but also a secondary disaster such as a fire caused by an earthquake is prevented. In order to provide a function for early detection such as gas leakage, a so-called microcomputer gas flow meter with a built-in microcomputer (hereinafter referred to as a microcomputer meter) has begun to be used. This microcomputer meter has a built-in microcomputer and battery, detects vibrations and falls due to an earthquake, abnormally large outflow of gas, and long-term outflow of a small amount of gas, etc., and closes the built-in solenoid valve etc. The accidents caused by these are prevented before they occur.

Regarding the detection of an earthquake, it is necessary to distinguish between the vibration of an earthquake caused by the collision of a flying object on the microcomputer meter, the artificial vibration caused by the traveling of a car or the construction site, and the vibration of an earthquake. For that purpose, it is necessary for the seismic sensor to exhibit a predetermined operating characteristic in the frequency band which is the vibration region of the earthquake, and to exhibit another operating characteristic in the other frequency bands.

For example, the vibration of an earthquake is a combination of vibrations of various frequencies, but mainly vibrations of 10 Hz or less, particularly 5 Hz or less, are used as a substitute characteristic of the earthquake in the inspection of seismic devices. For example 3.3Hz, 2Hz, 1.4
It is performed by applying a sine wave vibration of 3 Hz. Therefore, for example, in a seismic sensing device using a seismic sensitive device having a contact point that is turned on and off by swinging an inertial element such as a conductive sphere, for example, one ON signal whose duration is 40 milliseconds or more is used. Also, when the off signal is output within a predetermined time, for example, three times or more in three seconds, the microcomputer determines that an earthquake occurs and outputs a signal to distinguish it from other disturbance vibrations.

[0006]

Since the location of an earthquake is unpredictable and is not limited, the seismic sensor has a structure that does not have directivity so that it has the same characteristics for seismic waves from any direction. There is a need. Therefore, the above-mentioned "sensitizer"
In the seismic sensor element 101, an inclined surface that gently rises concentrically from the center toward the outside is formed on the bottom surface of the container, and as shown in FIGS. 6 (A) and 6 (B), a glass is provided substantially at the center of the container upper lid 102A. Conductive terminal pin 1 insulated and fixed by 103
The contact member 104 is conductively fixed so that the contact portion is arranged on the circle indicated by the symbol A centering on the conductive terminal pin 106 at the end of 06, and when the conductive ball 105 swings due to vibration, the contact member 104 When the container 102 and the contact member 104 are brought into contact with each other, they are electrically short-circuited and a detection signal is emitted. In addition, FIG. 6 (A) is a top cover 1 of the seismoscope of FIG.
FIG. 7B is a cross-sectional view showing a state before 02A is fixed to the container body 102B, and FIG. 6B is a view from the direction B in FIG. 6A. Further, in 107, the conductive sphere 105 is the contact member 104.
This is a protective plate for directly contacting the vicinity of the fixed portion between the conductive terminal pin 106 and the conductive terminal pin 106 to prevent deformation.

However, the vibration-sensing element 101 of this "sensing device"
In order to prevent so-called chattering and bouncing that occur when the contact member 104 and the conductive sphere 105 come into contact with each other, the contact member 1 is prevented from colliding with each other so that the contact does not result in a collision between rigid bodies.
04 has a flexible structure. Therefore, for example, the contact member 104 has a thin conductive material, for example, a thickness of 50 μm.
When the above phosphor bronze is used, the contact member 104 is distorted by heat or the like generated when it is fixed to the conductive terminal pin 106 by a method such as welding. Although this distortion is slight at the fixed portion, it is magnified at the tip 104A of the contact member 104, and as a result, the positional relationship of the contact portions near the tip 104A of the contact member changes before and after fixing. It is necessary to design the parts in consideration of the amount of change. Furthermore, as shown in FIG. 7A and FIG. 7B which is an arrow view from the direction C, a contact portion which should be located on a circle centering on the conductive terminal pin 106 is large and an ellipse indicated by a distortion symbol D. When the conductive ball 105 rolls into a non-circular shape, the distance from the center to reach the contact portion when the conductive ball 105 rolls varies depending on the rolling direction. The acceleration required for contact for a predetermined time varies depending on the vibration direction,
As a result, the characteristics of the seismic sensing element 101 have an unpredictable directivity.

Therefore, a structure has been considered in which the contact member 104 is not directly fixed, but is sandwiched and held by the conductive terminal pin 106 and the protective plate 107 so that the contact member 104 does not generate heat during welding. Since the contact member 104 is sandwiched in the vicinity of the welded portion between the conductive terminal pin 106 and the protective plate 107, the heat during welding may be transferred to the contact member, causing distortion more than an acceptable level.

[0009]

A seismic sensing element of the present invention includes a cover plate having a circular metal plate, which has a hole formed at substantially the center thereof, through which a conductive terminal pin penetrates and is electrically insulated and fixed. The housing has a cylindrical conductive housing, and an inclined surface that gently rises concentrically from the center toward the outside is formed on the bottom surface of the housing, and the opening end of the housing is provided at the peripheral edge of the lid plate. Are fixed to each other to form a container, and a conductive material having a plurality of flexible elastic blade-shaped portions in which contact portions are arranged substantially in a circle around the conductive terminal pin at the end of the conductive terminal pin of the lid plate. A contact point made of metal is electrically conductively fixed, and a conductive solid inertial sphere is housed inside the container so that it is positioned in the approximate center of the housing by gravity when stationary in a normal posture, and is subjected to vibration. The inertia sphere swings and contacts the contact member In a seismic element configured to slide and slide, and at the same time short-circuit the inner surface of the housing and the contact member via an inertial sphere, heat generated at the time of fixing in the vicinity of the fixed portion of the contact member with the conductive terminal pin. Also, a slit is provided to prevent the distortion due to this heat from being transmitted to the outer peripheral portion.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a seismic element 1 of the present invention, FIG. 2 is a plan view of an example of a contact member used in the present invention, FIG. 2 (A) is its plan view, and FIG. 2 (B) is Figure 2
It is an enlarged view of the E section enclosed with the dashed-two dotted line of (A). This seismic element 1 has a lid plate 5 in which a conductive terminal pin 4 is airtightly fixed to a metal plate 2 with an insulating material 3 such as glass or ceramics, and a cylindrical housing 6 having a bottom. The closed container is configured by fixing the portion to the opening of the housing 6 by ring projection welding or the like.

A conductive ball 7, which is a conductive solid inertial ball such as iron, copper, or an alloy thereof, is rotatably housed inside the closed container, and is normally concentric from the center of the housing 6 toward the outside. It is placed at the center of the inclined surface 6A that gently rises in a circular shape, and maintains a predetermined distance in all directions with respect to a contact member described later. The conductive terminal pins 4 are made of a conductive material such as phosphor bronze having a plurality of flexible blades 8A having a flexible elastic contact portion arranged in a circle on the inner end of the closed container. The contact member 8 is electrically conductively fixed so that it can come into contact with the conductive sphere 7. It should be noted that the inner wall of the housing 6 is provided with a plurality of protrusions 6B, and for example, the seismic element is subjected to a large impact or the like, and the conductive sphere 7 is attached to the housing 6
This protrusion 6B acts as an abutting portion when attempting to start an orbital movement along the inner wall of the, and the direction of movement of the conductive ball 7 is suddenly changed to temporarily disconnect the contact between the contact member 8 and the conductive ball 7 and turn on the ON signal. It is possible to avoid the continuous output of 1) and to rapidly reduce the kinetic energy of the conductive sphere 7 due to the collision with the projection 6B, to quickly converge the orbital motion of the inertial sphere and restore the normal reciprocating motion.

As shown in FIG. 2, the contact member 8 has a through hole 8B at its center, and the contact member 8 is fixed to the conductive terminal pin 4 through the through hole 8B. The protective plate 9 is electrically conductively fixed to 4 by a method such as welding. That is, the contact member 8 is not directly fixed to the conductive terminal pin or the like, but the conductive terminal pin 4 and the protective plate 9
It is sandwiched and held by. Not only is the protective plate 9 used for fixing the contact member, but the protective plate 9 is provided to prevent deformation of the contact member due to collision of the conductive ball 7 with the contact member 8 near the base thereof.

Further, in the present invention, the slit 8C is provided around the through hole 8B of the contact member 8 over substantially the entire circumference so that the strain due to heat generated when the contact member 8 is fixed is not transmitted to the outer peripheral portion thereof. ing. This point will be described with reference to FIG. 3, which is an enlarged view of the F portion indicated by the chain double-dashed line in FIG. 1, and the protective plate 9 has its welded portion 9A inserted into the through hole 8B of the contact member 8 and the conductive terminal pin 4 is inserted. It is fixed to the end portion by a method such as electric resistance welding. At the same time, the contact member 8 is welded to the welded portion 9A of the protective plate 9 near the peripheral edge portion 8D of the through hole 8B.
It is sandwiched and held by the sandwiching portion 9B provided around the periphery of the and the end of the conductive terminal pin 4.

When the protective plate 9 is welded to the conductive terminal pin 4, the temperature near the welded portion 9A of the protective plate becomes instantaneously high. At this time, since the through hole 8B of the contact member 8 has a size substantially the same as the diameter of the welded portion 9A of the protective plate 9 for positioning and the inner peripheral portion thereof is adjacent to the welded portion, the heat during welding penetrates. It is transmitted from the inner circumference of the hole 8B to the peripheral edge portion 8D. Distortion is generated in the peripheral edge portion 8D by this welding heat, but since the slit 8C is provided almost all around the peripheral edge portion 8D, the generated strain is prevented from being transmitted to the outside of the slit 8C and is not distorted. Since the outer peripheral portion is held by the sandwiching portion, there is almost no influence on the positional relationship of the tips of the contact members. Further, since the welding heat is hardly transmitted to the outside of the slit 8C, distortion does not occur at the outer circumference of the slit and does not affect the positional relationship of the tip of the contact member.

In this embodiment, the slit 8C has three circular arcs, but the number thereof is not limited to this, and if there is no problem in terms of size or strength, it can be doubled or more as shown in FIG. It goes without saying that it is even more effective.

In the embodiment, the seismic element in which the lid plate and the housing form a closed container has been described as an example. However, the seismic element is used in a non-fouling atmosphere, or the contact member, the conductive ball and the inner surface of the housing are plated. When the antifouling measure is taken, a non-sealing structure may be adopted in which the cover plate is attached to the opening of the housing by a method such as caulking.

[0017]

According to the seismic element of the present invention, the slits are provided so as to surround the fixed portion of the contact member over substantially the entire circumference, so that the heat generated at the time of fixing by welding or the strain due to this heat is slit. Since it does not transmit to the outside, the positional relationship of the tips does not change due to the strain generated around the fixed portion when a contact member having a very thin plate is used.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of a seismic element of the present invention.

FIG. 2 is an example of a contact member used in the seismic element of the present invention, (A) is a plan view and (B) is a partially enlarged view thereof.

FIG. 3 is a partially enlarged view of the seismic element in FIG.

FIG. 4 is a partially enlarged view of another embodiment of the contact member used in the seismic element of the present invention.

[Fig. 5] Example of conventional seismic element

FIG. 6 is an example of a contact member and its peripheral members used in a conventional seismic element, where (A) is a plan view and (B) is its B.
View from the direction of the arrow

FIG. 7 is a view showing a modified example of the contact member of FIG.
(A) is a plan view, (B) is an arrow view from the C direction

[Explanation of symbols]

 1: Seismic element 2: Metal plate 3: Insulating material 4: Conductive terminal pin 5: Lid plate 6: Housing 7: Conductive sphere 8: Contact member 8A: Wing portion 8B: Through hole 8C: Slit 9: Protective plate

Claims (1)

[Claims] 1. A circular metal plate having a cover plate, which penetrates a conductive terminal pin and is electrically insulated and fixed in a hole formed substantially in the center, and a bottomed cylindrical conductive housing. An inclined surface is formed on the bottom surface of the housing so as to rise concentrically from the center toward the outside, and an opening end of the housing is fixed to the peripheral edge of the lid plate to form a container. At the end of the conductive terminal pin, a contact member made of a conductive material, which has a plurality of blades having flexible elasticity and has contact portions arranged substantially in a circle centering on the conductive terminal pin, is conductively fixed, An electrically conductive solid inertial sphere is housed inside the container so that it is located in the approximate center of the housing due to gravity when stationary in a normal posture. Displaces and slides at the same time In a seismic element configured to short-circuit the inner surface of the contact member and the contact member via an inertial sphere, heat generated at the time of fixing in the vicinity of the fixed portion of the contact member with the conductive terminal pin and distortion due to this heat Seismic element characterized by having slits to prevent transmission to the outer periphery.