JP3016086B2 - Seismic sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of the Invention> The present invention is, for example, attached to a printed circuit board for gas meters or other gas appliances, and automatically detects a vibration such as an earthquake that exceeds a predetermined value. The present invention relates to a seismic sensor used to achieve a disaster prevention function such as cutting or automatic extinguishing of a combustion device.

<Prior art and its problems> Japanese Patent Application Laid-Open No. 55-21510 and Japanese Utility Model Application Laid-Open No.
As disclosed in Japanese Unexamined Patent Publication No. 55-119938, a sphere such as a steel ball is placed on a spherical or tapered tray and the switch is opened and closed by rolling of the sphere due to vibration. A spherical type that is configured to
For example, as disclosed in Japanese Utility Model Laid-Open No. 55-28938, Japanese Utility Model No. 55-60529, Japanese Utility Model No. 55-28948, a pendulum weight is suspended, and the pendulum weight or There is a pendulum system configured to detect horizontal or horizontal and vertical movement of a movable body integrally provided.

In the case of the former spherical-type seismic sensor, since a saucer constituting the rolling surface of the spherical body is required, the diameter of the entire seismic sensor is likely to be increased in the horizontal direction and large.

On the other hand, in the case of the latter pendulum type seismic sensor, although it is easier to reduce the size in the horizontal direction than the above-mentioned spherical type, it is necessary to increase the pendulum suspension distance in order to improve sensitivity. The length of the seismic sensor in the vertical direction is likely to be large, making it difficult to reduce the size. Also, in the case of a conventional pendulum type seismic sensor, which is disclosed in Japanese Utility Model Laid-Open No. 55-28938 and Japanese Utility Model Laid-Open No. 55-60529, the fulcrum for movement of the pendulum weight is one point. Therefore, it is very difficult to set the initial operation acceleration with respect to the vibration intensity, that is, the seismic intensity, and the seismic performance and the accuracy are unstable.

Further, in the case of the conventional pendulum type seismic sensor disclosed in Japanese Utility Model Laid-Open No. 55-28948, a hemispherical movable shaft connected to the upper end of the suspension shaft of the pendulum weight is inserted into a circular hole. As the fulcrum structure is used, the circular hole gradually increases due to wear during use, so the actual length of the pendulum arm changes over time, and the seismic performance changes. There is a disadvantage that.

Further, in order to swing the pendulum weight, it is necessary to swingably insert the upper end of the suspension shaft into a through hole of a base provided on the case side and to support the suspension shaft in a neck-hanging manner. In addition, it is impossible to prevent the suspension shaft from being eccentric with respect to the axis of the through hole during the swinging motion (see Japanese Utility Model Application Laid-Open No. 60-7304).

Therefore, when the motion conversion mechanism for converting the horizontal motion of the pendulum weight into a vertical motion is configured by the neck hanging portion of the suspension shaft of the pendulum weight, when trying to reduce the size, the seismic characteristics change and the There is a problem that it is not possible to achieve a natural seismic operation.

<Object of the Invention> The present invention has been made in order to solve the above-mentioned conventional problems. It is possible to reduce the size of the whole, easily set the seismic intensity, and stably maintain a predetermined seismic performance for a long period of time. The purpose is to provide a seismic sensor that can be used.

<Structure and Effect of the Invention> A seismic sensor according to the present invention includes a pendulum weight that is installed in a case and moves horizontally, a motion conversion mechanism that converts the horizontal motion of the pendulum weight into a vertical motion, A detector for detecting the vertical motion of the pendulum weight converted by the mechanism, wherein the motion conversion mechanism is provided in a through-hole in a vertical direction in a base provided on the case side. The upper end of the suspension shaft is swingably inserted, and the suspension shaft is coaxial with the through hole on the upper surface of the base and has a bottom surface of a concave portion having a diameter larger than that of the through hole. The hanging portion formed to bulge at the upper end of the pendulum is abutted and supported in a neck-hanging manner, and is formed on the annular portion formed on the lower surface of the hanging portion and the bottom of the concave portion when the pendulum weight moves horizontally. Up and down with the fulcrum as the fulcrum of the ring It is characterized in that it is configured to convert to oscillating motion.

In addition, the receiving seat includes a bottom surface of an annular groove formed coaxially on an outer peripheral portion of the through hole, and an annular shape that abuts on an inner peripheral edge of the receiving seat in an edge shape. It is recommended that the tip of the pendulum be projected from the lower surface of the suspension of the pendulum weight.

ADVANTAGE OF THE INVENTION According to the seismic sensor which concerns on this invention, when more than a certain vibration, such as an earthquake, is applied, the pendulum weight will make a horizontal motion, and this horizontal motion will be converted into a vertical motion by the motion conversion mechanism part, and the vertical motion will be detected. The length of the pendulum weight can be made independent of the setting of the operating acceleration. Accordingly, since the pendulum system is used and the length of the pendulum weight does not need to be too large to improve the sensitivity, the overall size can be reduced in both the horizontal direction and the vertical direction. .

In addition, since the fulcrum for movement of the pendulum weight is constituted by an annular hanging portion formed on the hanging shaft side of the pendulum weight and an annular receiving seat abutting on the annular portion of the hanging portion. , It is easy to set the initial operation acceleration for the vibration intensity,
Seismic performance and accuracy can be stabilized. Also,
Since the relative movement between the annular portion of the hanging portion and the receiving seat that comes into contact with the annular portion is limited, a change in performance due to wear can be prevented, and the service life can be increased.

Further, by changing the radius of the annular hanging portion and the annular receiving seat, the set operation acceleration, that is,
The seismic intensity can be easily adjusted.

<Description of Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing the structure of a seismic device according to one embodiment of the present invention. The seismic device is roughly divided into a cylindrical case 1 and a horizontal movement that is installed in the case 1. A pendulum weight 2, a motion conversion mechanism 3 for converting horizontal motion of the pendulum weight 2 into a vertical motion, and a detector for detecting the vertical motion of the pendulum weight 2 converted by the motion conversion mechanism 3 An automatic leveling mechanism 5 for automatically horizontally holding the seismic sensor comprising the pendulum weight 2, the motion converting mechanism 3 and the detector 4 when the case 1 is attached in an inclined manner; And a viscous liquid damper section 6 which provides a vibration damping action to the damper.

The case 1 is composed of a case body 1A which opens upward and a case cover 1B which is mounted on the upper part of the case body 1A. A pair of external fixed terminals 7A and 7B are erected in a state of protruding below the main body 1A, and extending the upper end part into the case cover 1B,
The opening of the case body 1A corresponding to the central portion between the pair of opposed external fixed terminals 7A and 7B is the case body 1A.
Are traversed in the radial direction, and a flat bar-shaped beam member 8 is erected.

The pendulum weight 2 has a suspension shaft 9 penetrating the center thereof, and a truncated conical suspension portion 9A as shown in FIG. 2 is formed at the upper end of the suspension shaft 9. On the other hand, a through-hole 11A having a diameter allowing the horizontal movement of the suspension shaft 9 is formed in the disk-shaped middle base 11 suspended from the case 1 via an automatic horizontal mechanism 5 described later. In addition, an annular seat 11b abuts on the upper end of the through-hole 11A and a peripheral edge of the annular lower surface of the frustoconical hanging portion 9A.
A large-diameter concave portion 11B having the following shape is formed. A suspension portion at the upper end of the suspension shaft 9 is provided on an annular seat 11b of the large-diameter concave portion 11B.
9A, the horizontal motion of the pendulum weight 2 is converted into a vertical swing motion with the contact point between the annular seat 11b and the peripheral portion of the lower surface of the hanging portion 9A as a fulcrum R. A motion conversion mechanism 3 for converting is configured.

Assuming that the inner diameter of the fulcrum R in the vertical motion conversion mechanism 3 is ld and the distance from the fulcrum R to the center of the suspension shaft 9, that is, lg, is lg, the operation acceleration G of the pendulum weight 2 is G = (ld / lg) × 980 ……… (1) Therefore, by changing the diameter of the above-mentioned truncated conical hanging portion 9A and concave portion 11B, the set operation acceleration G of the pendulum weight 2, that is, the sensed seismic intensity of this seismic sensor can be adjusted. .

The detector 4 comprises a contact switch mechanism for converting the vertical motion of the pendulum weight 2 converted by the vertical motion conversion mechanism 3 into an electric signal. As shown in FIG.
The upper surface of the middle base 11 is formed with a notch 11C formed of four branch holes 11c1 and a circular hole 11c2 at the center, and has a similar shape to the notch 11C dropped into the notch 11C from above. The central disk portion 13a of the movable piece 13 abuts on the top surface of the suspension portion 9A of the suspension shaft 9, and the movable contact 14 is fixed to the upper surface of the central disk portion 13a.

On the other hand, a strip-shaped fixing piece 17 having one end 17a sandwiched between the middle base 11 and a disc-shaped base 16 fixed to the upper surface of the middle base 11 via a plurality of screws 15 is provided. A fixed contact that allows the movable contact 14 to come and go at the center in the longitudinal direction.
The movable contact 14 and the fixed contact 18 constitute a contact switch mechanism serving as the detector 4.

In the peripheral portion of the upper surface of the middle base 11 corresponding to the other end portion 17b in the longitudinal direction of the fixing piece 17, a notch groove 11D having a width slightly larger than the width of the fixing piece 17 is formed. A female screw hole 11d is formed on the bottom surface of 11D, and a notch hole 16A is formed in the periphery of the base 16 corresponding to the other end portion 17b of the fixing piece 17 as well, and through this notch hole 16A By adjusting the screwing amount of the contact position adjusting screw 28 screwed into the female screw hole 11d from the through hole 17C of the other end 17b of the fixing piece 17, the other end 17b of the fixing piece 17 is
The distance between the two contacts 14 and 18 is variably configured by vertically displacing the one end 17a side as a fulcrum. The movement acceleration of the pendulum weight 2 can be finely adjusted by changing the distance between the two contacts 14 and 18.

Also, a movable terminal 19 formed integrally with the movable piece 13 and bent upward is protruded above the base 16 through holes 17d and 16B formed in the fixed piece 17 and the base 16, respectively. At the same time, the fixed terminal 20 cut and raised from the fixed piece 17 protrudes above the base 16 through the cut hole 16A of the base 16. As shown in FIG. 4, these movable and fixed terminals 19 and 20 are arranged opposite to a pair of external fixed terminals 7A and 7B fixed to the case main body 1A, and between the opposed terminals 19 and 7A and 20, 7B
Coiled lead wires 21 and 22 are interposed therebetween, respectively. These coiled lead wires 21 and 22 have notches 19 formed at both ends thereof at the upper ends of the terminals 19, 7A and 20, 7B.
a, 7Aa and 20a, 7Ba by dropping from above and caulking or brazing to
7A and 20a and 7B are electrically connected to each other.

As shown in FIGS. 1 and 4, a fulcrum member 23 having a convex spherical portion 23a protruding upward is press-fitted and fixed to a central portion in the longitudinal direction of the beam member 8 provided on the case body 1A. At the same time, a disk-shaped movable member 24 having a concave spherical portion 24a at the center of the lower surface which is in point contact with the spherical portion 23a of the fulcrum member 23 is provided, and extends downward from a radially opposed portion of the movable member 24. At the lower ends of the pair of hanging pieces 25, 25, locking claws 25a, 25a projecting outward in the radial direction are integrally formed, and the pair of hanging pieces 25, 25 are formed on the base 16. Insert below the base 16 from the through holes 16C, 16D,
By locking the locking claws 25a, 25a to the lower surface of the base 16, an automatic horizontal mechanism 5 of a jiro bay type is formed, which automatically holds the seismic sensing unit horizontally when the case 1 is inclined. .

The viscous liquid damper part 6 is connected to the case cover 1B.
And a ring-shaped liquid-tight member 26 fitted into the case cover 1B, a flexible thin film 27 such as rubber having a thick portion 27a having a substantially circular cross section around the periphery thereof, and an oil filled in a void. Of the viscous liquid 28. Specifically, the first
As shown in the figure, the outer peripheral thick portion 27a of the flexible thin film 27 arranged on the inner surface side of the top wall portion 1Ba of the case cover 1B is sandwiched between the top wall portion 1Ba of the case cover 1B and the liquid-tight member 26. By fixing in a liquid-tight manner, a gap 29 is formed between the case cover 1B and the flexible thin film 27, and the case cover 1B
After filling the cavity 29 with the viscous liquid 28 from the hole 1Bb provided in the hole 1Bb, the hole 1Bb is
A predetermined viscous liquid damper portion 6 is formed by sealing through a through hole. The case cover 1B
At the center of the top wall 1Ba, a projection 31 is provided to project resistance to the flow of the enclosed viscous liquid 28 to enhance the damper function.

The flexible thin film in the viscous fluid damper unit 6
The upper surface of the disk-shaped movable member 24 in the automatic horizontal mechanism 5 is brought into contact with the lower surface of the
In addition, a vibration damping effect is applied to the seismic sensing portion, and the same seismic sensing characteristics are maintained in both the horizontal mounting and the tilt mounting of the case 1.

Next, the overall operation of the seismic device configured as described above will be described.

In the state of FIG. 5 (A) in which the cable 1 is mounted horizontally on a printed board for gas meter, for example, so that the center of the suspension shaft 9 of the pendulum weight 2 is vertical, the movable contact of the contact switch mechanism 4 is provided. 14 and the fixed contact 18 are separated as shown in FIG. 5 (B).

In this mounting state, when vibrations equal to or less than a set value such as an earthquake are applied, as shown in FIG. 6A, the pendulum weight 2 horizontally moves at the acceleration G shown in the above equation (1).
The horizontal motion is converted into vertical motion by swinging the hanging portion 9A at the upper end of the hanging shaft 9 up and down around the fulcrum R with this horizontal motion, and the force is amplified by leverage. By this vertical movement, the central disk portion 13 of the movable piece 13
As shown in FIG. 6 (B), a is elastically displaced upward and abuts on the movable contact 14 and the fixed contact 18 of the contact switch mechanism 4 to be turned on.

As a result, the coiled lead wire 22, the fixed terminal 20, the fixed piece 17, the contacts 18, 1
4. A predetermined detecting operation is performed by electrically conducting through the movable piece 13, the movable terminal 19 and the coiled lead wire 21.

Further, when the case 1 is attached at an angle, the whole of the seismic unit is held horizontally as shown in FIG. 7 by the automatic leveling action of the automatic leveling mechanism 5 described above. At this time, since the upper surface of the disk-shaped movable member 24 of the automatic horizontal mechanism unit 5 is in contact with the lower surface of the flexible thin film 27 of the viscous liquid damper unit 6, the relative movement between the case 1 and the whole of the vibration sensing unit is achieved. Swaying of the seismic sensor beyond a certain level due to a large inclination displacement is restricted, and an unexpected detection operation can be prevented.

In such an inclined mounting state, the seismic operation when a vibration equal to or more than a set value such as an earthquake is applied is almost the same as in the above-described horizontal mounting state, and a description thereof will be omitted.

FIG. 8 shows a deformation structure of the motion conversion mechanism 3 for converting the horizontal motion of the pendulum weight 2 into a vertical motion, and a U-shaped hanging portion 9A having a cross section opening downward at the upper end of the hanging shaft 9. ,
An annular groove 1 is formed on the outer surface of the through hole 11A on the upper surface of the disk-shaped middle base 11.
1B1 is formed, and the pointed end 9a of the peripheral wall of the hanging portion 9A is brought into contact with an annular seat 11b formed by the bottom surface of the annular groove 11B1 to support the hanging shaft 9 by hanging the neck. The swing fulcrum R for vertical motion conversion in this case is a contact point of the pointed tip 9a with the seat 11b, and by changing the inner diameter of the peripheral wall of the hanging part 9A and the diameter of the annular groove 11B1. The set operation acceleration G of the pendulum weight 2 can be freely adjusted.

In addition to the contact switch mechanism described in the above embodiment, the vertical movement detector includes a capacitance sensor, an optical sensor, a reed switch sensor, a pressure-sensitive sensor, a differential transformer sensor, a magnetic sensor, and the like. In any case, the same effect as in the above embodiment can be obtained.

Further, in the above embodiment, the present invention is applied to a seismic device provided with the automatic leveling mechanism 5, but it is also possible to apply the present invention to a seismic device not having the automatic leveling mechanism 5 and the damper portion 6.

As the damper 6, a viscous liquid type as shown in the above embodiment is optimal, but the same effect can be obtained by using an air damper.

Further, in the above embodiment, the fulcrum member 23 is press-fitted into the beam member 8 and fixed, but may be formed integrally with the beam member 8.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a seismic sensor according to an embodiment of the present invention, FIG. 2 is an enlarged longitudinal sectional view of a vertical motion conversion mechanism, and FIG. 3 is a detailed configuration of a contact switch mechanism. FIG. 4 is an exploded perspective view of the main part shown in FIG. 4, FIG. 4 is a perspective view of the main part showing the configuration of the automatic horizontal mechanism, FIG. 5 (A), (B), FIG.
(B) and FIG. 7 are longitudinal sectional views for explaining the seismic operation, respectively, and FIG. 8 is an enlarged longitudinal sectional view of a vertical motion converting mechanism of the seismic device according to another embodiment of the present invention. . DESCRIPTION OF SYMBOLS 1 ... Case, 1A ... Case main body, 1B ... Case cover, 2 ... Pendulum weight, 3 ... Motion conversion mechanism part, 4 ... Contact switch mechanism (an example of a detector), 9 ... Hanging Shaft, 9A…
… Hanging part, 9a …… Sharp tip, 11 …… Base, 11A…
... through-hole, 11B ... recess, 11B1 ... annular groove, 11b ... annular receiving seat, R ... fulcrum.

──────────────────────────────────────────────────続 き Continued from the front page (72) Norio Iwakiri, Inventor No. 10, Hanazono Todocho, Ukyo-ku, Kyoto-shi, Kyoto Omron Corporation (56) References JP-A-57-74625 (JP, A) 141432 (JP, U) Real opening 60-6034 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01H 1/00

Claims (2)

(57) [Claims] 1. A pendulum weight which is installed in a case and moves horizontally, a motion converting mechanism for converting the horizontal motion of the pendulum weight into a vertical motion, and a vertical motion of the pendulum weight converted by the mechanism. A detector for detecting a motion, wherein the motion converting mechanism portion swingably inserts an upper end portion of a suspension shaft of the pendulum weight into a through hole in a vertical direction of a base provided on the case side. And a suspension portion bulged at the upper end of the suspension shaft in an annular receiving seat formed on the upper surface of the base and being coaxial with the through hole and having a bottom surface of a concave portion having a diameter larger than that of the through hole. Abutting the neck of the pendulum to move the pendulum weight horizontally, and the annular portion formed on the lower surface of the hanging portion and the annular peripheral portion of the receiving seat formed at the bottom of the concave portion. It is configured to convert to vertical swing motion with this contact as a fulcrum. Earthquake Detector, characterized in that there. 2. The receiving seat comprises a bottom surface of an annular groove formed coaxially on an outer peripheral portion of the through hole, and has an annular tip portion which abuts on an inner peripheral edge of the receiving seat in an edge shape. The seismic device according to claim 1, wherein the pendulum weight protrudes from a lower surface of a hanging portion of the pendulum weight.