JPH07113684A - Acceleration response switch - Google Patents

Abstract

PURPOSE:To obtain an acceleration response switch without any erroneous operation over a wide operating temperature range. CONSTITUTION:A conductive inertia ball 7 is housed inside the closed container of an acceleration response switch 1, a vibration-controlling liquid 9 is injected, and a contact member 6 is fixed to the terminal part of a lead terminal 3 which is insulated and fixed. The inertial ball 7 is normally positioned near the center and does not contact the contact member 6. When a vibration exceeding a specific value is applied. the inertia ball 7 rolls, contacts the contact member 6, and electrically connects a housing 5 and the contact member 6. Also, when the inertia ball 7 performs an orbital motion along the side wall of the housing 5, the inertial ball 7 contacts a contacting part 5C, the direction of motion is changed, and the motion is regulated by the vibration-controlling liquid 9, and the continuous contact between the contact member 6 and the inertial ball 7 is disconnected, thus avoiding continuous output of ON signal. Also, even if the regulation effect of the vibration-controlling liquid 9 is reduced, malfunction can be prevented in cooperation with the contacting part 5C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration responsive switch for detecting earthquake vibrations, etc., and is intended to reliably distinguish earthquake vibrations from disturbance vibrations.

[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". This seismic sensor has an electrode that is electrically insulated and fixed in a metal container and houses a conductive ball so that it can swing, and when the conductive ball swings due to shaking, it contacts the electrode. By doing so, the container and the electrode are electrically short-circuited and a detection signal is emitted.

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 running 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 composite of vibrations of various frequencies, but it is mainly composed of vibrations of 10 Hz or less, especially 5 Hz or less. For example, 3.3Hz, 2Hz, 1.
It is performed by applying a sine wave vibration of 43 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.

In order to distinguish the earthquake from the disturbance vibration by such a method, the seismoscope outputs different signals in the frequency band which is the vibration region of the earthquake and other frequency bands. Necessary, eg 3.3Hz, 2Hz, 1.4
When a sine wave of 3 Hz is applied, it corresponds to a seismic intensity of 5 120
The microcomputer outputs an earthquake occurrence command at around gal and activates a safety device such as closing the gas shutoff valve, so that the microcomputer does not perform control operation even at 300 gal when vibration exceeds 5 Hz, for example, 6 Hz to 7 Hz or more. I have to

Further, when a control device such as a micom meter or the like is greatly tilted or falls due to some cause such as a large earthquake, a repetitive signal from the seismic sensor cannot be expected, so that a continuous ON signal has a predetermined time, for example, 1 second or more. If it continues, the control device is operated.

[0008]

These conventional control devices such as microcomputer meters are often installed outdoors because of meter reading and the like. For example, they are installed on the outer wall of a building with piping. Therefore, depending on the installation location, it may face a passageway of a person or a children's playground. For example, when a person passes by, a person's body, luggage, a bicycle, etc. may hit, or a catch ball, etc. may hit. In this case, although there is some difference depending on the distance between the support positions of the fixing fittings of the gas pipe, etc., after a shock wave of 1000 to 3000 gal, the vibration acceleration is attenuated from about 1000 gal of a sine waveform at a cycle of about 10 Hz. It was confirmed by the experiment that is applied to the gas meter.

Since such a vibration has a frequency of about 10 Hz, theoretically the signal from the seismic sensor is synchronized with this cycle, so that at least the ON signal or the OFF signal does not reach 40 milliseconds, and for example, the ON time. Assuming that the OFF time becomes equal, the ON signal and the OFF signal of 25 milliseconds, which is a considerably shorter time interval than that, are emitted, so that the microcomputer does not perform the control operation in which the earthquake is recognized.

However, when the impact is large, the inertial member may rotate along the inner wall of the container or the electrode. In this case, since the inertial element and the electrode are in continuous contact with each other, a continuous ON signal is generated. Therefore, unless the circular motion of the inertial sphere generated by the impact of disturbance is quickly converged, the ON signal continues for a set time or longer, and the signal cannot be distinguished from the signal due to the inclination of the microcomputer meter as described above, and the control device may malfunction. Yes, making it difficult to distinguish between earthquakes and disturbance vibrations.

A spherical body is used as an inertia element in a cylindrical or hemispherical container, for example, the above-mentioned Japanese Patent Application No. 4-2723.
In the case of the seismic sensor of No. 87, the trajectory can be changed when it comes into contact with the contact member, and the vibration direction intersects due to the difference in the resonance frequency and the excitation frequency due to the shape of the bottom surface of the housing and the mass of the inertial element. Due to the existence of a slight acceleration component in the direction, the inertial sphere deviates from the center of the housing, and the resonance of the inertial sphere and the movement in that direction are amplified from the conical bottom shape at a frequency of 7 Hz to 8 Hz, for example. 8
Orbital movements such as circular movements and elliptical orbits may begin. Also in this case, ON signal and OFF signal 7Hz to 8Hz
Based on the frequency of, for example, a signal longer than 31 to 36 milliseconds and longer than 40 milliseconds may be generated, and the control device malfunctions as described above because it satisfies the condition for judging the earthquake given to the microcomputer. It makes it difficult to distinguish between earthquakes and disturbance vibrations.

In order to solve such a problem, the applicant of the present invention filed on October 1, 1993, "acceleration responsive switch", a protrusion is provided on the inside of the container, and the We propose a structure that absorbs the energy of the orbital motion of the inertial sphere by colliding with the projection and disturbs the resonance motion of the inertial sphere, thereby converging the orbital motion early. Also, in the "acceleration response switch" filed on October 6, 1993, the damping liquid is injected into the container together with the inertia sphere to suppress undesired rolling of the inertia sphere and to cause the rolling in the vibration direction. A patent application has been filed in which a damping force is applied by a vibration damping liquid to prevent the movement of the inertial sphere to orbital movement due to the resonance movement, and the orbital movement due to impact is quickly converged.

However, in the case where the damping liquid is injected into the container, the viscosity of the damping liquid is greatly affected by the temperature thereof, and therefore, especially at low temperature, for example, -30 ° C., under normal conditions, for example, 25 ° C. On the other hand, the viscosity of the vibration damping liquid becomes higher, so that the inertial sphere becomes hard to move and the desired performance may not be obtained. As a countermeasure for this, there is a method of selecting a damping liquid having sufficient fluidity even at a low temperature, or reducing the injection amount thereof to adjust the regulation force against the inertia sphere.

However, those which have sufficient fluidity even at low temperature have a lower viscosity at high temperature, for example, 60 ° C., so that the regulation effect is lowered, and depending on the type of damping liquid, the boiling point may be below the maximum operating temperature of the switch. However, there is a problem that it cannot be used at high temperatures. Further, even if the injection amount is reduced, the change in the viscosity of the damping liquid remains unchanged. Therefore, if the injection amount is such that normal operation is performed at low temperature, the regulation effect becomes insufficient at high temperature. There is a problem. As described above, it is difficult to obtain stable operation in a wide temperature range from a low temperature to a high temperature in the case of using the damping liquid.

Further, in the case where the projection is provided inside the container, since there is no element depending on the temperature, the operation is always stable from low temperature to high temperature. The regulation effect is slightly inferior.

[0016]

Therefore, the acceleration-responsive switch of the present invention is a cover plate in which a conductive lead terminal is penetrated by an electrically insulating filling material into a hole formed at a substantially center of a substantially circular metal plate so as to be hermetically fixed. And a bottomed cylindrical conductive housing, on the bottom surface of which is formed an inclined surface that rises concentrically from the center toward the outside, and the housing is provided at the periphery of the lid plate. The open end of the lid is airtightly fixed to form a closed container, and a plurality of supple elastic members are provided at the end of the lead terminal inside the container of the lid plate, in which the contact portions are arranged substantially concentrically around the conductive terminal pin. A contact member made of a conductive material having a vane-shaped portion is conductively fixed, and a conductive solid inertial sphere is positioned inside the sealed container at the center of the bottom surface of the housing due to gravity when stationary in a normal posture. To do The inertial ball rolls when it is housed and subjected to vibration to contact the contact member to displace its vane-shaped portion and slide, and at the same time short-circuit the inner surface of the housing and the contact member via the inertial ball. An inner surface of the housing is provided with an abutting portion on a wall surface portion of the inertia sphere that is in contact with the inertia sphere when a predetermined acceleration is applied regardless of the stationary state, and the inertia sphere applies a rotational force along the inner wall of the housing. The contact between the inertial sphere and the contact member is discontinuously disturbed by intermittently abutting against the abutting part when the inertial sphere is undesired in the closed container. It is characterized in that a predetermined amount of damping liquid is injected to suppress such rolling.

Another feature is that a pollution preventing gas such as an inert gas is enclosed in the space inside the closed container.

Still another feature is that the damping liquid has the dissolved gas removed in advance by a degassing process.

Still another feature is that the damping liquid is a fluorine-based inert liquid.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show one embodiment of the acceleration responsive switch of the present invention, and FIG. 1 is a vertical cross section thereof taken along line B- of FIG.
FIG. 2 is a sectional view taken along the line B, and FIG. 2 is a sectional view taken along the line AA of the acceleration response switch of FIG. The acceleration responsive switch 1 has a metal circular lid plate 2, and a through hole 2A is formed in the center of the lid plate 2, and a conductive lead terminal 3 is inserted into the through hole 2A. It is airtightly insulated and fixed by an electrically insulating filler 4 such as glass. A flange portion 2B is provided on the peripheral edge portion of the cover plate 2, and the opening end of a cylindrical metal housing 5 having a bottom is hermetically fixed to the flange portion 2B by a method such as ring projection welding so that the vibration damping liquid is long. A closed container is constructed so that it does not leak over a period of time.

A contact member 6 made of a conductive material is conductively fixed to the tip of the lead terminal 3 inside the closed container by welding or the like. The contact member 6 has a plurality of blade-shaped portions 6A having supple elasticity, and the contact portion with the inertial sphere 7 described later is arranged substantially concentrically around the conductive terminal pin 3. If the mass of the inertial sphere is about 0.7 grams,
The material of the contact member 6 has a thickness of 0.01 to 0.0, for example.
A 3 mm phosphor bronze plate is used.

An electrically conductive inertial sphere 7 is housed in the closed container, and is normally positioned on a stationary portion 5B provided near the center of the conical housing bottom surface 5A when stationary in a normal posture. . The inertia sphere 7 is a conductive solid sphere such as iron, copper, or an alloy thereof, and is subjected to surface treatment such as silver plating if necessary. The inertia sphere 7 is made rollable on the housing bottom surface 5A by vibration of a predetermined magnitude or more due to an earthquake or the like, and the blade-shaped portion 6 of the contact member 6 is provided.
It can be contacted with and separated from A. A protective plate 8 made of a thick metal plate is fixed to the lower surface of the fixing portion between the lead terminal 3 and the contact member 6, and the contact point of the inertia ball 7 due to the contact of the contact member 6 with the vicinity of the base of the contact member 6. The deformation of the member is prevented.

Liquid 9 as a damping material is injected into the closed container. This damping liquid 9 is an inert liquid whose viscosity and injection amount are selected. The damping liquid is preferably a liquid having a relatively low viscosity and a small surface tension, such as a fluorine-based inert liquid such as Fluorinert (trademark, 3M Company). The injection amount is set to, for example, 1/4 of the diameter of the inertia sphere 7 to cover the whole, and a gas is allowed to exist on the free surface to prevent deformation of the closed container due to expansion and contraction of the damping liquid due to temperature change. ing.

On the inner side wall 5E of the container 5, there are provided projections 5C, which are collision parts, at four positions at equal intervals as shown in FIG. The protrusions 5C are formed by, for example, press molding, and the number thereof is determined by the resonance frequency determined by the size of the container and the inertia sphere, the material of the inertia sphere, and the like. Alternatively, it may be provided in three places, or of course, five or more places may be provided. In addition, due to reasons such as press working, the inertia ball 7
The rolling portion 5 within a range in which it can actually move before it hits the side wall 5E.
If it does not affect the shape of D, the abutting portion such as the protrusion 5C is located at a position where it does not abut the inertia ball 7 between the maximum movement position of the inertia ball 7 shown by the dotted line in FIG. 1 and the housing side wall 5E. It may be provided in a column shape from the outer side portion of the housing bottom surface 5A upward.

The amount of protrusion of the abutting portion to the inside of the container does not hinder the contact between the inertia ball 7 and the contact member 6 even if the inertia ball 7 is in contact with the protrusion 5C, and the contact member 6 protrudes 5C.
The height is selected so that the circular motion of the inertial sphere is surely diverted without making direct contact with. Further, by making the width of the container at the abutting portion in the circumferential direction as narrow as possible, it is possible to minimize the chance that the inertial sphere 7 collides head-on with the abutting portion at the time of reciprocating vibration of the inertial sphere and the amplitude is reduced. When the inertia sphere 7 hits the projection 5C, which is an abutting part, head-on, the inertia sphere 7 reaches the side wall 5E of the housing 5, and the amplitude of the inertia sphere 7 decreases. Since it does not occur, the contact time with the contact member 6 is hardly affected.

Next, the operation of the acceleration response switch will be described. The inertial sphere 7 is positioned on the stationary portion 5B of the housing bottom surface 5A when it is stationary in the normal posture, and in this state, the inertial sphere 7 does not contact the contact member 6 and the lead terminal 3, the housing 5 and the lid 2 are not contacted. Since no electrical connection is made between them, no signal is output.

When the acceleration responsive switch 1 is subjected to horizontal vibration of a predetermined value or more, the inertia ball 7 moves the inertia ball 7 to the bottom surface 5A of the housing.
The contact member 6 and the housing 5 are electrically short-circuited by rolling on the rolling portion 5D of the contact member and contacting the blade-shaped portion 6A of the contact member 6, and the lead terminal 3-contact member 6-inertial sphere 7-
An electric path is formed in the path of the housing 5 and the cover plate 2, and a signal is output.

If the vibration reciprocates in a certain direction when the inertia sphere rolls, the inertia sphere theoretically reciprocates on the center line of the housing determined by the vibration direction. However, in reality, the orbit is changed when it comes into contact with the contact member, and the acceleration component in the direction intersecting with the vibration direction is very small due to the difference in the resonance frequency and the excitation frequency due to the shape of the housing bottom surface and the mass of the inertial element. However, due to the existence of the sphere, the inertia sphere deviates from the center of the housing, and at a certain frequency, the resonance of the inertia sphere and the movement in that direction are gradually amplified due to the conical bottom surface shape. Orbital motion such as circular orbit may start.

However, in the present invention, the rolling of the inertia sphere 7 is restricted by the injection of the damping liquid 9 together with the inertia sphere 7 into the closed container, and the inertia sphere in the direction orthogonal to the vibration direction. The rolling of No. 7 is practically eliminated, and the rolling is almost ideal. This is because the vibration damping liquid 9 is injected into the closed container, so that the resonance frequency of the inertia sphere 7 can be lowered to a region of 1 Hz or less, and therefore, the inertia sphere in the direction orthogonal to the vibration direction is undesired. Is not amplified, and rolling in this direction is a very slight movement in the vibration direction, so the movement of the inertial sphere is almost ideal, and of course the inertial sphere makes a circular motion. Never start.

Here, the kinematic viscosity of the damping liquid 9 is determined by the inertia sphere 7.
Is selected so that there is practically no problem in the contact operation with the electrodes. For example, in the examples, a vibration damping liquid having a kinematic viscosity of 0.6 centistokes at room temperature is 0.6.
When 2 to 0.5 g was used, the damping liquid 9 was not injected in response to the vibration due to the sine wave, and the inertia ball 7 started rolling at 110 gal, while the damping liquid 9 What injected was started to roll at 120 gal, and this acceleration is within the range of 80 gal to 250 gal corresponding to seismic intensity 5, and there is practically no problem.

Further, when the frequency is set to 7 to 8 Hz and the acceleration is increased to vibrate at a value of, for example, 200 to 300 gal, the difference between the resonance frequency and the vibration frequency due to the shape of the bottom surface of the housing and the mass of the inertia element. Due to a slight acceleration component generated in a direction intersecting with the vibration direction, when the damping liquid 9 is not injected and no collision part is provided, the inertia sphere 7 moves in the direction intersecting the vibration direction. While the rolling is amplified and the inertial sphere 7 makes an orbital motion to generate an undesired signal, in the case where the vibration damping liquid 9 is injected, such an orbital motion is hardly regulated and generated. It was possible to substantially limit the rolling of the inertia ball 7 to rolling in the vibration direction.

Further, when a strong impact is given to a device to which the acceleration response switch 1 is attached by hitting a person or a ball, the inertia ball 7 may start rotating along the housing 5 and the contact member 6. At this time, in the present invention, since the damping liquid 9 is injected and the abutting portion is provided on the inner surface of the housing, the rotational movement can be converged in a short time. Therefore, even if a signal is output, by shortening the convergence process, it is possible to avoid repetition of the signal that meets the above conditions, and the microcomputer does not perform an undesired control operation. This is because when the inertial sphere 7 starts an orbital motion due to an impact, the inertial sphere 7 collides with the projection 5C which is a collision portion to change its trajectory, and the damping liquid 9 lowers the resonance frequency of the inertial sphere 7. This is because the orbital movement cannot be maintained, and the vibration of the inertia sphere cannot be maintained against the damping liquid by the vibration that is rapidly attenuated after the impact.

For example, in the example, in the impact test at room temperature, in the case where the damping liquid 9 is not injected and the inner surface of the housing does not have the abutting portion, the rolling of the inertial sphere takes 2
While it took 0 to 30 seconds, the rolling of the inertial sphere converges within 10 seconds or less in the same test in this embodiment.
Therefore, for example, as described above, in the case where the microcomputer judges that there is an earthquake when the ON signal and the OFF signal each having a duration of 40 milliseconds or more are output three times or more in 3 seconds, 4
Although the ON signal of 0 ms or more is generated in the process of convergence of the rolling of the inertial sphere 7, the rolling of the inertial sphere is converged within the range where it does not come into contact with the contact member before it occurs three times and before this. With such a shock, the microcomputer will not make a false decision that an earthquake has occurred.

When the acceleration response switch into which the damping liquid is injected is used at a low temperature as described above, the viscosity of the damping liquid becomes high, so that the restricting force against the operation of the inertia sphere becomes large and a predetermined vibration is given. In some cases, the contact time of the inertia sphere with the contact member is shortened, and for example, the ON signal of 40 ms or longer is not output, or the inertia sphere does not contact the contact member and the signal is not output. However, in the present invention, the damping liquid 9 is selected such that its viscosity is not more than a predetermined value even at the lowest operating temperature. For example, in this embodiment, the kinematic viscosity is -30 ° C. It is about 0.5 centistokes, and outputs an ON signal for a predetermined time at 160 gal for excitation by a sine wave, and this acceleration is within the range of 80 gal to 250 gal corresponding to seismic intensity 5 as described above. .

Of course, the frequency is set to 7 at -30 ° C.
Even when the vibration is applied at ˜8 Hz and at a acceleration of 200 to 300 gal, the vibration damping liquid 9 restricts the orbital motion due to the vibration component in the direction intersecting with the vibration direction of the inertia sphere 7, so that the rolling of the inertia sphere 7 is prevented. Substantially only rolling in the vibration direction can be performed, and an undesired signal is not emitted.

Further, in the impact test at -30 ° C,
In this embodiment, due to the effect of the damping liquid and the contact portion, the rolling of the inertia sphere 7 converges in 10 seconds or less. Therefore, the microcomputer does not erroneously determine that an earthquake has occurred when a ball hits the microcomputer meter.

However, in this embodiment, the damping liquid 9 is used even at a low temperature.
Since the viscosity was selected so that it would not exceed the specified value,
On the contrary, at high temperature, the viscosity may be too low, and the regulation effect of the vibration damping liquid 9 may not be sufficiently obtained. Therefore, in the present invention, in order to compensate for the decrease in the regulation effect of the damping liquid 9, the projection 5C as an abutting portion is provided on the inner surface of the container 5. Therefore, even if the viscosity of the vibration damping liquid 9 is lowered due to the rise in temperature and the regulation effect thereof is reduced, the inertia sphere 7 is restricted from rolling by the projection 5C, and shifts to the orbital movement in the same manner as the state at room temperature. Can be regulated. When the inertial sphere 7 starts to make a circular motion due to a shock or the like, the inertial sphere 7 can change its direction of motion by colliding with the protrusion 5C, and at the same time deprive the energy of the circular motion, so the state at room temperature Similarly to, the orbital motion and rolling of the inertial sphere can be converged at an early stage. At this time, although the damping liquid 9 has a low viscosity, it does not give a restricting force to the rolling of the inertia sphere 7, and therefore, the damping liquid 9 is used under all conditions within the range of use. And the contact part both contribute to the early convergence of the rolling of the inertial sphere.

In the present embodiment, for example, the kinematic viscosity of the damping liquid 9 is 0.4 centistokes or less at 60 ° C., and the inertial sphere 7 starts rolling at 120 gal when it is excited by a sine wave. ing. When the acceleration responsive switch 1 is vibrated at 60 ° C. with a frequency of 7 to 8 Hz and an acceleration of 200 to 300 gall, the viscosity of the vibration damping liquid 9 decreases, and the shape of the bottom surface of the housing and the inertia The slight acceleration component generated in the direction intersecting with the vibration direction due to the difference between the resonance frequency and the vibration frequency due to the mass of A cannot be sufficiently suppressed only by the damping liquid. Therefore, if there is no contact part, inertia ball 7
In some cases, the rolling in the direction crossing the vibration direction of A is amplified and the inertial sphere 7 begins to make an orbital motion and emits an undesired signal. Since the rolling is restricted by the protrusion 5C, the orbital motion of the inertial sphere can be restricted even with the damping liquid whose viscosity is lowered.
The rolling of the inertial sphere 7 can be substantially only rolling in the vibration direction.

Further, for example, when a strong impact is given by a person or a ball hitting the device to which the acceleration response switch 1 is attached, and the inertia ball 7 starts to rotate along the housing 5 and the contact member 6, a high temperature is generated. Although the regulation effect of the vibration damping liquid 9 is weakened below, since the projection 5C as an abutting portion is provided in the present embodiment, the movement direction of the inertial sphere 7 is changed and the kinetic energy is taken away by the abutment with the projection 5C. Therefore, the orbital motion and rolling of the inertial sphere can be converged in a short time in cooperation with the damping liquid 9. Therefore, even if the signal is output, by shortening the convergence process, it is possible to avoid repetition of the signal that meets the above conditions,
The microcomputer does not perform an undesired control operation.

For example, in an impact test at 60 ° C., if there is no abutting portion, it will take 15 to 20 to converge the rolling of the inertia ball 7.
Although it took about 2 seconds, the rolling of the inertial sphere 7 converges in 10 seconds or less in the embodiment. Therefore, the microcomputer does not erroneously determine that an earthquake has occurred when a person or a ball hits the microcomputer meter.

Further, in the present invention, by injecting the inert vibration damping liquid 9 into the closed container, it becomes difficult for minute foreign matter to adhere to the surfaces of the contact member 6 and the inertia sphere 7, and
At the time of vibration, the inertia sphere 7 stirs the damping liquid 9 to cause a flow, so that these minute foreign substances are easily dropped. Therefore, the electric signal becomes reliable, and the desired performance can be maintained for a long time.

In this embodiment, the viscosity of the vibration damping liquid 9 is selected, and an example is used in which the viscosity is kept below a predetermined value even at -30 ° C. The regulation effect on the inertia sphere 7 may be adjusted by adjusting the injection amount instead of using one. For example, if a liquid having a kinematic viscosity of about 0.8 centistokes at room temperature and a kinematic viscosity of about 3.5 centistokes at −30 ° C. is used as the damping liquid, the injection amount into the housing is 0.2 to 0. When the weight is set to 0.5 g, the rolling of the inertia sphere is suppressed by the vibration damping liquid at -30 ° C, and the ON signal for a predetermined time is not output even for a sine wave of 300 gal.

Therefore, the injection amount of the damping liquid is set to, for example, 0.1 g or less to reduce the regulating effect of the damping liquid on the inertial sphere, so that the inertial sphere will roll even when the kinematic viscosity of the damping liquid increases. Will not be restricted more than necessary. Also, even when the kinematic viscosity of the damping liquid decreases at high temperatures and the regulation effect decreases, the energy of the rotational motion of the inertial sphere is deprived by the provision of the abutment part, and the damping effect of the damping liquid decreases. The amount is compensated and the orbital motion of the inertial sphere can be quickly converged.

Usually, in these acceleration-responsive switches, since the voltage used is relatively low and the current is weak, the contact resistance greatly changes when an oxide film or the like is generated on the surfaces of the contact member and the inertia sphere and the inner surface of the container. Therefore, the container of the switch main body is hermetically sealed, and an inert gas such as helium or argon, or nitrogen or hydrogen is substituted and sealed in the internal space as a pollution prevention gas to prevent generation of an oxide film or the like. In particular, when helium is contained, it is preferable that an airtightness inspection can be performed with a helium leak detector.

Further, in order to prevent an oxide film or the like from being generated on the surfaces of the contact members and the inertia spheres or the inner surface of the container due to the gas such as oxygen dissolved in the vibration damping liquid, the vibration damping liquid from which the dissolved gas has been removed in advance by the degassing treatment is put into the container. By injecting it together with an inert gas, it is possible to obtain an acceleration responsive switch having stable characteristics for a long period of time without invading each member. Further, the surface treatment such as silver plating is applied to the surfaces of the contact member and the inertia sphere and the inner surface of the container, so that not only the influence of dissolved gas disappears but also it becomes unnecessary to replace and seal the pollution preventing gas in the internal space.

The shape of the abutting portion is not limited to the protrusion as shown in FIG. 1, but any shape can be used as long as the inertial sphere suddenly changes its movement direction and reduces kinetic energy when the inertial sphere shifts to a rotational movement. For example, as shown in FIGS. 3 and 4, the structure may be such that the abutting member is fixed in the housing.
In this embodiment, the same members as those in the above-mentioned example are designated by the same reference numerals and the description thereof will be omitted. The damping liquid 9 whose viscosity and the like are selected is also injected into the container of the acceleration response switch 21 of this embodiment to regulate the orbital movement and the undesired rolling of the inertia sphere 7.

The contact member 22 of this embodiment is made of metal such as iron or its alloy, resin, or the like, as shown in FIG.
As shown in (A) and (B), the ring-shaped base portion 22A is provided with the contact portions 22B at equal intervals. By inserting and fixing the base portion 22A into the bottomed cylindrical housing 23, the abutting portions 22B are arranged at predetermined positions, and in the embodiment, eight contact portions 22B are provided at equal intervals. Since the base portion 22A of the abutting member 22 is ring-shaped and the rolling portion of the inertial sphere 7 is located inside this, the abutting member 22 does not affect the basic rolling characteristics of the inertial sphere 7. .

The effect of the abutting portion 22B of the abutting member 22 is similar to that of the projection 5C described above, but since the abutting member 22 is a member separate from the housing, for example, a material thinner than the housing is used. By using a material that is easily elastically deformed, it is possible to design so as to absorb a large amount of kinetic energy of the inertia sphere 7 in comparison with the protrusion 5C that is closer to a rigid body when colliding with the inertia sphere 7. In cooperation with 9, the rolling of the inertial sphere 7 can be converged more quickly.

Further, as shown in the transverse sectional view of the housing 35 shown in FIG. 6, the side wall 35A of the housing is formed into a polygonal shape or has a non-circular cross sectional shape by changing the curvature, so that the side wall 35 is formed.
A may substantially be an abutting portion to make the orbital movement of the inertial sphere 7 along the inner surface of the housing 35 unstable and to make the movement converge by the damping liquid by the regulating effect. In this case as well, the cross-sectional shape of the inertia ball rolling portion 35C on the housing bottom surface 35B is not changed and the basic rolling characteristics of the inertia ball 7 can be prevented from being affected. Further, if the shape is designed in consideration of the relative size with the diameter of the inertia sphere 7 so as to minimize the difference in the ON time caused by the difference in the rolling distance depending on the rolling direction of the inertia sphere 7, the vibration of the vibration is substantially eliminated. There is no obstacle to detection.

FIG. 7 shows an example in which these acceleration responsive switches are attached to a microcomputer meter or the like. This seismic sensor 11 has a case 12 accommodating the acceleration response switch 1. A suspension portion 13 is provided on the lead terminal 3 of the acceleration response switch 1 and is suspended by a hanger 14A of a holder 14 provided in the case 12 so as to be swingable. It is designed to be in a posture. One end of the flexible lead wires 15A and 15B is electrically connected to the cover plate 2 and the lead terminal 3 of the acceleration response switch 1, and the other end of each lead wire is a connection terminal 16A,
The conductive terminals 17A and 17B are insert-molded in the case 12 via 16B. A predetermined amount of viscous fluid 18 is filled in the case 12, and an outer lid 19 is hermetically sealed at the opening end of the case 12 such that the viscous fluid 18 does not leak out.

The seismic sensor 11 is directly attached to a printed circuit board or the like of the control device, and is connected to wiring on the board by conductive terminals 17A and 17B. Due to the structure of the acceleration responsive switch according to the present invention, the mounting posture has a great influence on the operating characteristics. For example, when the switch is tilted 1 degree from the normal posture, the operating acceleration changes by about 20 gal. Since the mounting posture requires a high degree of accuracy, it is very difficult to directly mount the acceleration responsive switch 1 on the printed circuit board in a regular posture. However, since the acceleration response switch 1 is hung in the case 12 in the seismic response device 11, if the mounting posture of the seismic response device is within the range of the allowable inclination angle, the acceleration response switch 1 automatically moves to the normal position by its own weight. Therefore, the work is easy because the precision required for mounting is not required.

The case 12 has an acceleration response switch 1
In addition, since a viscous fluid 18 such as silicone oil whose viscosity has been selected is injected, the acceleration response switch is used when the device equipped with the seismic sensor 1 falls or suddenly tilts, or against vibration such as an earthquake. 1 substantially follows the movement of the case 12 and generates an operation signal. Further, the viscous fluid 18 is selected so as to return to the normal posture within 30 seconds with respect to the inclination at the time of mounting. As described above, the seismic sensor having the structure as shown in FIG. 2 can be easily mounted and the vibration of the earthquake, the steep inclination and the fall can be surely detected.

It should be noted that each numerical value in the above embodiments is a matter of design, and it is obvious that the injection amount and the viscosity of the damping liquid are different from the above numerical values depending on the design change. Further, it is needless to say that the value of the acceleration at which the inertial sphere of the embodiment starts rolling can be adjusted by changing various conditions such as the bottom surface shape of the housing.

Although the acceleration-responsive switch used in the seismic sensor 11 of the embodiment has the metal cover plate in the embodiment, the damping liquid 9 and the viscous fluid 1 are described.
Resin or ceramic may be used as long as it can form a sufficient airtight container for 8 and can electrically insulate and fix the conductive lead terminals. In this case, one end of the lead wire 15A shown in FIG. 7 is conductively fixed to the housing 5.

[0055]

According to the present invention, by injecting the damping liquid into the housing, it is possible to suppress the undesired rolling of the inertia sphere due to the disturbance, and the rolling of the inertia sphere against the vibration given to the acceleration response switch. It is possible to eliminate the signal uncertainty due to the elliptical motion of the inertial sphere like the conventional one with a faithful reciprocating motion, and by providing an abutting part on the inner surface of the housing, the viscosity of the damping liquid at high temperature It is possible to compensate for the decrease in the regulation effect due to the decrease in

Further, when the inertial sphere rolls due to impact, the orbital motion and undesired rolling can be quickly converged by the damping liquid and the contact portion, and the output time of the signal in the converging process is shortened. By doing so, it is possible to avoid repetition of signals that meet the earthquake detection conditions by the microcomputer, prevent malfunction of the microcomputer meter, and reduce the regulation effect due to the decrease of the viscosity of the damping liquid at high temperature on the inner surface of the housing. It can be supplemented by the abutting part.

By substituting and enclosing the pollution preventing gas in the space in the closed container, generation of an oxide film or the like on the surfaces of the contact member and the inertia sphere and the inner surface of the container is prevented.

By removing the dissolved gas from the damping liquid by degassing in advance, it is possible to obtain an acceleration responsive switch having stable characteristics for a long period of time without invading each member. Further, the surface treatment such as silver plating is applied to the surfaces of the contact member and the inertia sphere and the inner surface of the container, so that not only the influence of dissolved gas disappears but also it becomes unnecessary to replace and seal the pollution preventing gas in the internal space.

Further, in the present invention, by injecting a fluorine-based inert liquid as a damping liquid into a closed container,
There is no concern that the contact liquid or the surface of the inertia sphere will be invaded by the vibration damping liquid itself, and it becomes difficult for dirt to adhere to each member. It becomes easy to remove dirt. Therefore, the electric signal becomes reliable, and since the fluorine-based inert liquid is stable, the desired performance can be maintained for a long time.

[Brief description of drawings]

FIG. 1 is an embodiment of an acceleration response switch of the present invention.

2 is a sectional view taken along line AA of the embodiment shown in FIG.

FIG. 3 is another embodiment of the acceleration response switch of the present invention.

FIG. 4 is a sectional view taken along line CC of the embodiment shown in FIG.

5 is an example of an abutting member used in the embodiment of FIGS. 3 and 4. FIG.

FIG. 6 is a cross-sectional view of an example of a housing of the acceleration response switch according to the present invention.

FIG. 7 shows an embodiment of a seismoscope using the acceleration response switch of the present invention.

[Explanation of symbols]

 1,21: Acceleration response switch 2: Lid plate 3: Lead terminal 4: Electrically insulating filler 5,23, 35: Housing 5C: Protrusion (impingement part) 6: Contact member 7: Inertial ball 8: Protective plate 9 : Damping liquid 22: Impact member 22B, 35A: Impact part

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[Procedure amendment]

[Submission date] December 2, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuyuki Watanabe 4-30 Hosho-cho, Minami-ku, Nagoya City Stock Association Inside the company Ikikata Seisakusho (72) Inventor Hideki Koseki 4-30 Hosho-cho, Minami-ku Nagoya City Stock Association Shabukata Factory

Claims (4)

[Claims] 1. A cover plate having a substantially circular metal plate, which is formed at a substantially central portion thereof and is airtightly fixed by penetrating a conductive lead terminal with an electrically insulating filling material, and a bottomed cylindrical conductive housing. An inclined surface is formed on the bottom surface of the housing, which gradually rises concentrically from the center toward the outside, and the opening end of the housing is airtightly fixed to the peripheral portion of the lid plate to form a closed container. A contact made of a conductive material having a plurality of lithematic elastic blade-shaped portions, each of which is formed with a contact portion arranged substantially concentrically around the conductive terminal pin at the end of the lead terminal inside the container of the lid plate. The member is electrically conductively fixed, and a conductive solid inertial sphere is housed inside the closed container so that it is located in the approximate center of the bottom surface of the housing due to gravity when it is stationary in a normal posture. Sphere rolls and contacts It is configured so as to come into contact with a member to displace its vane-shaped portion and slide, and at the same time short-circuit between the inner surface of the housing and the contact member via an inertial sphere. An abutting portion is provided on a wall surface portion that is irrelevant and comes into contact when a predetermined acceleration is applied, and when the inertial sphere is given a rotational force along the inner wall of the housing, the abutting portion intermittently abuts the abutting portion and travels along the path. It is configured so that the contact between the inertia sphere and the contact member is discontinuously disturbed, and a predetermined amount of damping liquid is injected into the closed container for suppressing undesired rolling of the inertia sphere. Acceleration responsive switch characterized by being 2. The acceleration-responsive switch according to claim 1, wherein a pollution preventing gas such as an inert gas is sealed in a space inside the closed container. 3. The acceleration-responsive switch according to claim 1, wherein the damping liquid has the dissolved gas removed in advance by a degassing process. 4. The acceleration response switch according to claim 1, wherein the damping liquid is a fluorine-based inert liquid.