JP2887556B2 - Acceleration response switch - Google Patents

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 an earthquake vibration or the like, and to reliably distinguish an earthquake vibration from a disturbance vibration.

[0002]

2. Description of the Related Art Conventionally, as this kind of acceleration responsive switch, there is, for example, a "seismic sensor" disclosed in Japanese Patent Application No. 4-27287. This seismic sensor has electrodes fixed electrically insulated from this container in a metal container and accommodates conductive balls so that they can swing. By doing so, the container and the electrode are electrically short-circuited to generate a detection signal.

[0003] In recent years, such a seismic sensor has been attached to a gas flow meter such as a city gas or a propane gas installed in each household to not only record the flow rate but also prevent a secondary disaster such as a fire caused by an earthquake. In order to provide a function for early detection of gas leakage or the like, a microcomputer type gas flow meter (hereinafter referred to as a microcomputer meter) incorporating a so-called microcomputer has begun to be used. This microcomputer meter incorporates a microcomputer and a battery, detects vibrations and falls due to earthquakes, abnormally large outflows of gas, and long-term outflows of small amounts of gas, etc., closes the built-in solenoid valve etc. and issues an alarm from an alarm Control to prevent accidents caused by these.

[0004] Among them, regarding the detection of an earthquake, it is necessary to discriminate between a collision of a flying object with a microcomputer meter and an artificial vibration caused by an automobile running or a construction site from an earthquake vibration. For this purpose, it is necessary for the seismic sensor to exhibit a predetermined operating characteristic in a frequency band which is a vibration region of an earthquake, and to exhibit another operating characteristic in other frequency bands.

For example, the vibration of an earthquake is a compound of vibrations of various frequencies, but mainly the vibration of 10 Hz or less, especially 5 Hz or less. For example, 3.3Hz, 2Hz, 1.4
This is performed by applying a 3 Hz sine wave vibration. Therefore, for example, in a seismic device using a seismic sensor having a contact that is turned on and off by the oscillation of an inertia such as the above-described conductive sphere, for example, an ON signal having a duration of 40 ms or more for one time is used. When an off signal is output within a predetermined period of time, for example, three times or more in three seconds, the microcomputer determines that an earthquake has occurred and outputs a signal to distinguish it from other disturbance vibrations.

In order to distinguish an earthquake from a disturbance vibration in such a manner, the seismic sensor outputs different signals in a frequency band which is a vibration region of the earthquake and in other frequency bands. It is necessary, for example, 3.3 Hz, 2 Hz, 1.4
When a sine wave of 3 Hz is applied, 120 corresponds to seismic intensity 5
The microcomputer outputs a command to generate an earthquake at about gal and activates a safety device such as closing a gas shut-off valve. If the vibration exceeds 5 Hz, for example, 6 Hz to 7 Hz or more, the microcomputer does not perform the control operation even at 300 gal. Must be.

[0007]

These conventional control devices, such as a microcomputer meter, are often installed outdoors for meter reading or the like. For example, they are mounted on the outer wall of a building with piping. Therefore, depending on the mounting location, the vehicle may face a path of a person or a playground for children, and may hit a body, luggage, a bicycle, or a catch ball when a person passes. In this case, after a shock wave of 1000 to 3000 gal, the vibration acceleration attenuates from a substantially sinusoidal waveform of about 1000 gal after a shock wave of 1000 to 3000 gal, although there is a slight difference depending on the distance between the supporting positions of the fixing fittings of the gas pipe. It has been found by experiment that is applied to the gas meter.

Since such a vibration has a frequency of about 10 Hz, the signal from the seismic sensor is theoretically synchronized with this cycle, so that at least the on signal or the off signal does not reach 40 milliseconds. Assuming that the off time and the off time are equal, an on signal and an off signal of 25 milliseconds, which are considerably shorter time intervals, are issued, so that the microcomputer does not perform a control operation that recognizes the earthquake.

However, the use of a sphere as an inertia in a cylindrical or hemispherical container is disclosed, for example, in the aforementioned Japanese Patent Application No. 4-272.
In such a device as the 387 seismic sensor, when the impact is large, the inertia may make a rotational movement along the inner wall of the container or the electrode. In this case, a continuous ON signal is generated because the inertia and the electrode are in continuous contact. For example, when the control device itself such as a gas meter tilts or falls over for some reason such as a large earthquake, a repeated signal from the seismic sensor cannot be expected, so if a continuous ON signal continues for a predetermined time, for example, 1 second or more, The control device is adapted to operate. Therefore, if the circular motion of the inertial sphere generated by the impact of the disturbance does not quickly converge, the ON signal continues for a set time or more, and the control device may operate, making it difficult to distinguish the earthquake from the disturbance vibration. .

[0010]

SUMMARY OF THE INVENTION The feature of the acceleration responsive switch of the present invention is that a lid in which a conductive lead terminal is penetrated through an electrically insulating filler into a hole formed substantially in the center of a substantially circular metal plate and hermetically fixed. Plate and a bottomed tubular conductive housing, and a bottom surface of the housing is formed with an inclined surface that gradually rises concentrically from the center toward the outside, and is formed on the periphery of the lid plate. The open end of the housing is hermetically fixed to form a closed container, and the lead terminal end inside the container of the lid plate is provided with a contact portion substantially concentrically around the conductive terminal pin. A contact member made of a conductive material having a wing-like portion having a conductive portion is conductively fixed, and a conductive solid inertial sphere is provided in the closed container substantially at the center of the bottom surface of the housing by gravity when stationary in a normal posture. To be located Housed, the contact of the lead terminal
The inertial sphere directly impacts the part where the contact member is fixed.
A protective plate for preventing contact is fixed, and the inertial ball rolls by receiving vibration, comes into contact with the contact member, displaces its wing-like portion and slides, and at the same time, moves between the inner surface of the housing and the contact member. The inertial sphere is configured to be short-circuited via an inertial sphere, and an inner surface of the housing is provided with an abutting portion on a wall portion that comes into contact when the inertial sphere receives a predetermined acceleration regardless of the stationary state, and the inertial sphere is provided in the housing. When a rotational force is applied along the inner wall of the contact member, the contact member intermittently contacts the contact portion to change the course, and the contact between the inertial ball and the contact member is discontinuously disturbed. is there.

Another feature is that the cover has a cover plate in which a conductive lead terminal is penetrated and fixed in a hole formed substantially in the center of a substantially circular plate-like body, and a bottomed cylindrical conductive housing. A bottom surface of the housing is formed with an inclined surface that gradually rises concentrically from the center to the outside, and an open end of the housing is fixed to the peripheral edge of the lid plate to form a container, and the lead terminal and the housing are formed. Is electrically insulated, and has a plurality of flexible elastic wing-like portions at which the contact portions are disposed substantially concentrically around the conductive terminal pins at the end of the lid terminal cover plate inside the container. conductive material made of contact members are conductively fixed, in the interior of the closed vessel is at rest in inertial ball normal posture of the conductive solid is accommodated so as to be positioned substantially at the center of the housing bottom by gravity, the
Inertial spheres are fixed to the contact members of the lead terminals.
Protective plate fixed to prevent direct contact near the attachment
In response to the vibration, the inertial sphere rolls and contacts the contact member to displace its wings and slide, and at the same time, short-circuits between the inner surface of the housing and the contact member via the inertial sphere. The inner surface of the housing is provided with an abutting portion on a wall portion with which the inertial sphere comes into contact when receiving a predetermined acceleration irrespective of the stationary state, and the inertial sphere is provided with a rotational force along the inner wall of the housing. In such a case, the contact portion is intermittently contacted with the contact portion to change the course so that the contact between the inertial ball and the contact member is discontinuously disturbed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the acceleration responsive switch according to the present invention, and FIG.
2 is a sectional view taken along a line AA of the acceleration responsive switch of FIG. 1. FIG. The acceleration responsive switch 1 has a circular cover plate 2 made of metal. A through hole 2A is formed in the center of the cover plate 2, and a conductive lead terminal 3 is inserted through the through hole 2A. It is hermetically insulated and fixed by an electrically insulating filler 4 such as glass. A flange portion 2B is provided on a peripheral portion of the cover plate 2, and an open end of a bottomed cylindrical metal housing 5 is air-tightly fixed to the flange portion 2B by a method such as ring projection welding.
The sealed container is configured so that the sealed gas does not leak for a long time.

A contact member 6 made of a conductive material is conductively fixed to the tip of the lead terminal 3 on the inner side of the sealed container by welding or the like. The contact member 6 has a plurality of wing-like portions 6A having flexible elasticity, and a contact portion with an inertial ball 7 described later is disposed substantially concentrically around the conductive terminal pin 3. When the mass of the inertial sphere is about 0.7 grams,
As a material of the contact member 6, for example, a thickness of 0.01 to 0.0
A 3 mm phosphor bronze plate is used.

A conductive inertial sphere 7 serving as an inertia element is housed in the closed container, and is normally located on a stationary portion 5B provided near the center of the conical surface of the housing bottom surface 5A when stationary in a normal posture. doing. The inertial sphere 7 is a conductive solid sphere such as iron, copper, or an alloy thereof, and has a side wall 5E inside the housing as shown by a dotted line on the housing bottom surface 5A due to vibration of a predetermined size or more due to an earthquake or the like. The contact member 6 is allowed to roll within a range until it comes into contact with the protrusion 5C, and is capable of coming into contact with and separating from the wing-like portion 6A of the contact member 6. A protective plate 8 is fixed to the lower surface of the fixing portion between the lead terminal 3 and the contact member 6 to prevent deformation of the contact member due to the contact of the inertial ball 7 near the root of the contact member 6.

As shown in FIG. 2, four projections 5C are provided at equal intervals on the inner side wall 5E of the container 5. The projections 5C are formed by, for example, press molding, and the number thereof is determined by a resonance frequency determined by the size of the container and the inertial sphere, the material of the inertial sphere, and the like. Alternatively, it may be provided at three places, or may be provided at five or more places. In addition, for reasons such as press working, the inertial sphere 7
Rolling part 5 in a range that can actually move before hitting the side wall 5E
If it does not affect the shape of D, the abutting portion such as the projection 5C may be provided in a column shape upward from the outer portion of the housing bottom surface 5A. Further, the amount of contact of the contact portion to the inside of the container is such that the contact between the inertial ball 7 and the contact member 6 does not hinder the contact between the inertial ball 7 and the contact member 6 even when the inertial ball 7 is in a position where the contact member 6 contacts the protrusion 5C. Instead, the height is selected so that the circular motion of the inertial sphere can reliably change course. In addition, by making the circumferential width of the container of the contact portion as narrow as possible, the chance that the inertial ball 7 collides with the contact portion head-on when the inertial sphere reciprocates vibrates to minimize the amplitude is reduced. Other than when the inertial ball 7 collides with the projection 5C, which is an abutting portion, from the front, the inertial ball 7 reaches the side wall 5E of the housing 5 if it strikes at a slight angle, and the amplitude of the inertial ball 7 decreases. The contact time with the contact member 6 is hardly affected.

Next, the operation of the acceleration responsive switch will be described. In the normal posture and at rest, the inertial sphere 7 is located on the stationary portion 5B of the housing bottom surface 5A. In this state, the inertial sphere 7 does not contact the contact member 6 and the lead terminal 3 and the housing 5 and the lid 2 Since no electrical connection is made between them, no signal is output.

When the acceleration responsive switch 1 receives a horizontal vibration equal to or more than a predetermined value, the inertial sphere 7
The contact member 6 and the housing 5 are electrically short-circuited by rolling on the rolling portion 5D of the contact member 6 and contacting with the wing-shaped portion 6A of the contact member 6, so that the lead terminal 3-contact member 6-inertial sphere 7-
An electric path is formed along the path from the housing 5 to the cover plate 2 to output a signal.

If the vibration is reciprocating in a fixed direction when the inertial sphere rolls, the inertial sphere theoretically reciprocates on the center line of the housing determined by the vibration direction. However, in reality, the inertial sphere 7 is moved to the center of the housing by a slight acceleration component acting in a direction intersecting with the vibration direction due to the contact of the electrode with one side or the imbalance of the slight unevenness on the rolling portion 5D. In a certain frequency, for example, within a certain range of 7 to 10 Hz, the resonance of the inertial sphere and the movement in the direction from the conical bottom shape are amplified, and the elliptical orbit or the circular orbit along the contact member or the container. May start circling. In such a case, in the conventional device without the control unit 5C, the interval between the on-time and the off-time corresponding to 1/4 of the period of the period determined by the vibration frequency is completely irregular. That is, if the on-time and the off-time are designed to be equal, for example, the maximum frequency for generating the on-time and the off-time of 40 milliseconds is 6.2.
Although the frequency is 5 Hz, when the above-mentioned irregular motion occurs, even if the frequency exceeds 6.25 Hz, for example, 8 Hz or 10 Hz, the on-time or off-time of 40 milliseconds occurs irregularly.

However, in the present invention, the side 5
When the orbital movement starts due to the provision of the projection 5C as an abutting portion on E, the inertial sphere 7 abuts on the projection 5C, the direction of movement of the inertial sphere 7 changes suddenly, and the contact between the contact member and the inertial sphere temporarily stops. To avoid the continuous output of the ON signal,
The kinetic energy of the inertial sphere 7 is rapidly reduced by the collision with the projection 5C, and the orbital movement of the inertial sphere can be converged at an early stage to return to a substantially normal reciprocating motion.

For example, when a strong impact is given to the device to which the acceleration responsive switch 1 is attached by hitting a person or a ball or the like, the inertial sphere 7 moves along the housing 5 and the contact member 6 if there is no contact portion. It may start spinning and continue for more than one second. Even in such a case, since the projection 5C is provided in the present invention, continuous output of the ON signal can be avoided for the above-described reason. In addition, since the orbiting motion of the inertial sphere 7 can be converged in a short time, even if the ON signal and the OFF signal are repeatedly output, the repetition of the signal meeting the above conditions is avoided by shortening the convergence process. And the microcomputer does not perform an undesired control operation.

For example, in the embodiment, in the impact test, it took 20 to 30 seconds for the motion of the inertial sphere 7 to converge in the case without the projection 5C as an abutting portion,
In the same test, the one having the protrusion 5C converged within 15 seconds or less. Therefore, for example, as described above, when the microcomputer determines that an earthquake occurs when an ON signal and an OFF signal each having a duration of 40 ms or more are output three times or more in 3 seconds, an ON signal of 40 ms or more is used. Are increased in the process of convergence of the motion of the inertial sphere 7, but the motion of the inertial sphere converges to micro-vibration without contact with the contact member before it occurs three times. The microcomputer does not mistakenly determine that an earthquake has occurred due to the impact.

The shape of the contact portion is not limited to the projection as shown in FIG. 1. If the inertial sphere suddenly changes its motion direction and shifts its kinetic energy when it shifts to rotational motion, For example, as shown in FIGS. 3 and 4, a structure in which an abutting member is fixed in a housing may be employed. In this embodiment, the same members as those in the above-described example are denoted by the same reference numerals, and description thereof will be omitted. The contact member 22 of the acceleration responsive switch 21 of this embodiment is formed of a metal or resin such as iron or an alloy thereof, and is formed on a ring-shaped base 22A as shown in FIGS. 5A and 5B. Contact part 22B at intervals
Is provided. By inserting and fixing the base portion 22A to the bottomed cylindrical housing 23, the contact portion 22B is arranged at a predetermined position. Since the base 22A of the contact member 22 is ring-shaped and the rolling portion of the inertial ball 7 is located inside the ring, the contact member 22 does not affect the basic rolling characteristics of the inertial ball 7. .

The effect of the contact portion 22B of the contact member 22 is the same as that of the above-described protrusion 5C. However, since the contact 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 deformed or elastically deformable, it can be designed so that the kinetic energy of the inertial sphere 7 can be absorbed more in comparison with the projection 5C that is close to a rigid body when the material comes into contact with the inertial sphere 7. Can converge more quickly.

As shown in FIG. 6, the side wall 35A of the housing is made polygonal or has a non-circular cross section by changing the curvature as shown in the cross sectional view of the housing 35.
A may be a substantially abutting portion, and a structure may be employed in which the rotational movement of the inertial sphere 7 along the inner surface of the housing 35 is made unstable to converge the movement. Also in this case, the housing bottom 3
The cross-sectional shape of the inertial ball rolling portion 35C on 5B is not changed and the basic rolling characteristics of the inertial ball 7 are not affected. In addition, if the shape is designed in consideration of the relative size with the diameter of the inertial sphere 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 inertial sphere, the vibration can be substantially detected. The trouble is gone.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 7, the same members as those in the above-described example are denoted by the same reference numerals, and detailed description thereof will be omitted. In this acceleration responsive switch 41, the cover plate 42 is made of an electrically insulating material such as resin or ceramics, and the lead terminal 3 is fixed through the center thereof substantially at the center. Housing 45
The bottom shape and the protrusion 45A are the same as those of the housing 5 shown in FIG. 1, but a fixing portion 45B is provided at the opening end thereof, and the fixing to the cover plate 42 is performed by caulking. Therefore, the welding operation is not required, and the manufacturing becomes easier.

Although the present embodiment is not a closed type as in the above-described embodiments, it is sufficient when used in, for example, a vacuum or an inert atmosphere. By subjecting the contact portion with the inertial sphere and the contact member 6 to a surface treatment, or using a material that does not corrode in the use atmosphere for each component, it can be used in the air in the same manner as the sealed type. In addition, by sealing the space between the fixing portion 45B and the cover plate 42 with an appropriate adhesive or the like, it can be used for a seismic device described later.

FIG. 8 shows an example in which these acceleration responsive switches are attached to a microcomputer meter or the like. The vibration sensor 11 houses the acceleration responsive switch 1 in a case 12. A suspending portion 13 is provided on the lead terminal 3 of the acceleration responsive switch 1 and is swingably suspended on a hanger 14A of a holding body 14 provided in the case 12. Normally, the acceleration responsive switch 1 is automatically operated normally. The posture is set. One ends of flexible lead wires 15A and 15B are electrically connected to the cover plate 2 and the lead terminal 3 of the acceleration responsive switch 1, and the other ends of the lead wires are connected to the connection terminals 16A and 16A.
It is connected to conductive terminals 17A and 17B insert-molded in case 12 via 16B. A predetermined amount of a viscous fluid 18 is filled in the case 12, and an outer lid 19 is hermetically sealed at the open end of the case 12 to such an extent that the viscous fluid 18 does not leak.

The vibration sensor 11 is directly attached to a printed circuit board or the like of the control device, and is connected to wiring on the circuit board by conductive terminals 17A and 17B. Due to the structure of the acceleration responsive switch according to the present invention, the mounting posture greatly affects the operation characteristics. For example, when the switch is tilted once from the normal posture, the operation acceleration changes by about 20 gal. Since high accuracy is required for the mounting posture, it is very difficult to mount the acceleration responsive switch 1 directly on the printed circuit board in the normal posture. However, in the case of the seismic sensor 11, the acceleration responsive switch 1 is suspended in the case 12, so that if the mounting posture of the seismic sensor is within the range of the allowable inclination angle, the acceleration responsive switch 1 is automatically set in the normal posture by its own weight. Therefore, no extra precision is required for the mounting, and the work becomes easy.

The case 12 has an acceleration responsive switch 1
At the same time, since the viscous fluid 18 such as silicone oil whose viscosity is selected is enclosed, an acceleration responsive switch is used when the device to which the seismic sensor 1 is mounted falls down or suddenly tilts or when vibration such as an earthquake occurs. 1 generates an operation signal substantially following the movement of the case 12. Further, the viscous fluid 18 is selected so as to return to a normal posture within 30 seconds, for example, with respect to 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 can reliably detect the vibration of the earthquake, the sharp inclination and the fall.

Although the acceleration responsive switch used in the seismic sensor 11 of the present invention has a metal cover plate in the embodiment, a sufficient airtight container for the viscous fluid 18 is formed. A resin or ceramic as shown in FIG. 7 may be used as long as it is possible to fix the conductive lead terminals by insulation. In this case, one end of the lead wire 15A shown in FIG.

[0031]

According to the present invention, a contact portion is provided on the inner surface of the housing to suppress the circular motion of the inertial sphere, whereby it is possible to prevent a continuous ON signal from being generated from the acceleration responsive switch. The uncertainty of the signal due to the elliptical motion of the inertial sphere like a thing can be eliminated.

When the inertial sphere rolls due to an impact, the kinetic energy can be quickly converged by the contact portion, and the signal output time in the convergence process is shortened to meet the condition of earthquake detection by the microcomputer. This avoids signal repetition and prevents malfunction of the microcomputer meter.

[Brief description of the drawings]

FIG. 1 is an embodiment of an acceleration responsive switch according to the present invention.

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

FIG. 3 shows another embodiment of the acceleration responsive switch of the present invention.

FIG. 4 is a sectional view taken along line CC of the embodiment of FIG. 3;

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

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

FIG. 7 is a cross-sectional view of another embodiment of the acceleration responsive switch of the present invention.

FIG. 8 shows an embodiment of a seismic sensor using the acceleration response switch of the present invention.

[Explanation of symbols]

 1, 21, 41: Acceleration response switch 2, 42: Cover plate 3: Lead terminal 4: Electrically insulating filler 5, 45: Housing 5C, 45A: Projection (contact portion) 6: Contact member 7: Inertial ball 8 : Protective plate 22: Contact member 22A: Contact portion

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hideki Koseki 4-30-30 Hoshocho, Minami-ku, Nagoya Investigator, Ikukata Manufacturing Co., Ltd. Hiroyuki Kikui (56) References JP-A-61-239191 (JP, A) JP-A-63-263423 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01H 1/00 H01H 35/14

Claims (2)

(57) [Claims] 1. A cover plate in which a conductive lead terminal is passed through a hole formed substantially in the center of a substantially circular metal plate through an electrically insulating filler and hermetically fixed, and a bottomed cylindrical conductive housing is provided. The bottom surface of the housing is formed with an inclined surface that gradually rises concentrically and gradually from the center to the outside, and the open end of the housing is air-tightly fixed to the peripheral edge of the lid plate to seal the closed container. A contact made of a conductive material having a plurality of pliable elastic wing-shaped portions formed and arranged with contact portions substantially concentrically around a conductive terminal pin at the end of the lead terminal inside the container of the lid plate. A member is conductively fixed, and a conductive solid inertial sphere is housed inside the closed container so as to be positioned at a substantially central portion of a bottom surface of the housing by gravity when stationary in a normal posture, and a contact member of the lead terminal is provided. In the fixed part Contact member sexual sphere
Protection plate to prevent direct contact near the fixing part of
The inertial sphere rolls by receiving vibration and comes into contact with the contact member to displace and slide its wings, and at the same time, short-circuits between the inner surface of the housing and the contact member via the inertial sphere. The inner surface of the housing is provided with an abutting portion on a wall portion with which the inertial sphere contacts when receiving a predetermined acceleration regardless of the stationary state, and the inertial sphere applies a rotational force along the inner wall of the housing. An acceleration-responsive switch characterized in that the switch is intermittently brought into contact with the contact portion to change the course when the contact is made, so that the contact between the inertial ball and the contact member is discontinuously disrupted. 2. A cover plate in which a conductive lead terminal is penetrated and fixed in a hole formed substantially in the center of a substantially circular plate-like body, and a bottomed cylindrical conductive housing, wherein a bottom surface of the housing is provided. Has an inclined surface gradually rising concentrically from the center toward the outside, and an open end of the housing is fixed to the peripheral portion of the lid plate to form a container. The lead terminal and the housing are electrically connected to each other. A conductive material having a plurality of pliable elastic wing-shaped portions in which contact portions are disposed substantially concentrically around the conductive terminal pins at the end of the lid terminal cover plate inside the container. The contact member is conductively fixed, and a conductive solid inertial sphere is accommodated in the closed container so as to be located at a substantially central portion of the housing bottom surface by gravity when stationary in a normal posture, and the lead terminal is Contact member fixing part The inertial sphere is a contact member
Protection plate to prevent direct contact near the fixing part of
The inertial sphere rolls by receiving vibration and comes into contact with the contact member to displace and slide its wings, and at the same time, short-circuits between the inner surface of the housing and the contact member via the inertial sphere. The inner surface of the housing is provided with an abutting portion on a wall portion with which the inertial sphere contacts when receiving a predetermined acceleration regardless of the stationary state, and the inertial sphere applies a rotational force along the inner wall of the housing. An acceleration-responsive switch characterized in that the switch is intermittently brought into contact with the contact portion to change the course when the contact is made, so that the contact between the inertial ball and the contact member is discontinuously disrupted.