JPH10170331A - Contact structure and seismic sensor using the same - Google Patents

Abstract

(57) [Problem] To provide a contact structure capable of ensuring a contact pressure between contacts and operating with a low load while reducing the size. SOLUTION: An outer peripheral portion of a contact plate 13 made of a spring plate material is fixedly supported on a case 1, and a plurality of arms 15 are formed in the peripheral portion of the contact plate 13 along a circumferential direction to form a central portion of the contact plate 13. A central movable portion 16 supported over the free ends of the arms 15 is formed on the central movable portion 16, and the central movable portion 16 is configured to be able to be displaced in the plate surface direction by being pressed by the plunger 3 at a plurality of locations. 16 is provided with an elongated tongue-shaped contact 17, and the movable contact 1 opposed to the fixed contact 19.
8 is provided at the free end of the contact 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact structure which is opened / closed by a displacement of an operating body, and a seismic device using the contact structure.

[0002]

2. Description of the Related Art FIG. 7 is a cross-sectional view of a conventional seismic device having a contact structure, and this seismic device is used as an operating body by the weight of a steel ball 31 rollably housed in a case 30. The plunger 32 is pushed in and displaced.
The movable piece 34 of the switch 33 is pressed and displaced at the lower end of
The movable contact 34a provided on the movable piece 34 is configured to contact the fixed contact 35 on the case side. When the steel ball 31 is stable at a predetermined position, the plunger is pushed and displaced by the weight of the steel ball 31. When the contact is closed by 32 and the steel ball 31 rolls under a vibration and moves out of a predetermined position, the movable piece 34 released from being pushed by the plunger 32 is elastically displaced and the contact is opened. I have.

[0003]

In the contact structure used in the above-mentioned seismic sensor, the lever ratio of the movable piece 34 is set so that the contact pressure between the contacts 34a and 35 becomes a predetermined value. However, when the size of the contact structure is reduced, the movable piece 34 itself becomes smaller, and it becomes difficult to secure a desired lever ratio, and the load for operating the movable piece 34, that is, the plunger operation load is reduced. There was a problem that it became large.

The present invention has been made in view of such a point, and provides a contact structure capable of ensuring a contact pressure between contacts and operating with a low load while reducing the size. A second object is to provide a small and highly sensitive seismic device using this contact structure.

[0005]

In order to achieve the above-mentioned object, the present invention is configured as follows.

That is, in the contact structure according to the first aspect of the present invention, a plurality of arms along the circumferential direction are cut and formed in a peripheral portion of a contact plate having a spring property, and the arm group is formed at a central portion of the contact plate. Forming a central movable portion supported over the free end of the movable member, the central movable portion being configured to be displaceable by a pressing operation of an operating body, and a contact facing a fixed contact being formed in the central movable portion. It is characterized by.

According to a second aspect of the present invention, in the contact structure according to the first aspect, the contact is formed in a tongue shape.

According to a third aspect of the present invention, in the invention according to the second aspect, a movable contact with respect to the fixed contact is provided at a free end of the contact.

According to a fourth aspect of the present invention, in the contact structure according to the second or third aspect, the operating body presses the central movable portion at a plurality of locations around the contact. .

According to a fifth aspect of the present invention, there is provided a seismic sensor comprising the contact structure according to any one of the first to fourth aspects, wherein the pressing member is pressed by the operating body in accordance with the rolling of the steel ball stored in the case. The operation or the pressing operation is released.

According to the first aspect of the present invention, since the plurality of arms provided on the peripheral portion of the contact plate are formed along the circumferential direction, the arm length can be made sufficiently large with respect to the size of the contact plate. This makes it possible to perform a displacement operation of the central movable portion which is continuously supported on the free end of the arm with a relatively small load. That is, even if the contact plate becomes smaller, the operating load of the operating body for displacing the central movable portion can be reduced.

According to the second aspect of the present invention, since the contact provided on the center movable portion is in the shape of a tongue, the contact can be easily elastically deformed and can contact the fixed contact without difficulty. .

In particular, according to the configuration of the third aspect, the movable contact is provided at the free end of the tongue-shaped contact, the contact pressure between the movable contact and the fixed contact can be set to a small value.

Further, according to the structure of the fourth aspect, the operation of the operating body is reliably transmitted to the central movable portion, and the central movable portion is displaced in a stable posture without being twisted. The contact provided on the central movable portion always acts on the fixed contact in a predetermined posture.

According to the seismic sensor having the structure according to the fifth aspect, since the plunger can be operated with a low load, it can be sensitively operated with a small and lightweight steel ball.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a seismic sensor will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional front view of a seismic sensor according to the present invention, and FIG.
1 is a sectional view taken along line aa of FIG. 1, FIG. 3 is a longitudinal sectional side view of the seismic sensor of FIG. 1, FIG. 4 is a sectional view taken along line bb of FIG. 1, and FIG.

This seismic device converts the rolling of a steel ball 2 housed in a resin case 1 into a vertical displacement of a resin plunger 3 as an operating body, and operates a built-in switch 4. Have been.

The case 1 is formed in a cylindrical shape, and an inclined guide portion 7 for stably dropping and mounting the steel ball 2 is formed in the center of the bottom wall 6 of the steel ball accommodating chamber 5 formed therein. The upper end of the steel ball accommodating chamber 5 is closed by a lid cover 8, and further, a pair of mounting portions 9 are protruded from a lower portion of the outer periphery of the case.

A switch case 10 having the switch 4 is fitted and fixed to a cylindrical boss 1a formed at a lower portion of the case 1, and a plunger 3 is provided with a steel ball at the center of the inclined guide portion 7. It projects through to the accommodation room 5 side.

The switch 4 is composed of a pair of terminal plates 11 and 12 inserted into a switch case 10 and a contact plate 13 having resiliency. Lead terminals (not shown) extend from both terminal plates 11 and 12. Have been.

The contact plate 13 is formed in a disk shape, and its entire outer peripheral portion is sandwiched between the fitting portions of the boss portion 1a of the case 1 and the switch case 10, and the one terminal plate 12 Contact connected. A slit 14 is formed in the outer peripheral portion of the contact plate 13, and four partially arcuate arms 15 are cut in a cantilever shape, and a circular central movable portion is formed over the free end of each arm 15. 16 are formed. The central movable portion 16 has a contact 17 in the form of an elongated tongue along its diameter, and a movable contact 18 provided on the lower surface of its free end.

The other terminal plate 11 is provided with a fixed contact 19 facing the movable contact 18,
When the movable contact 18 comes into contact with and separates from the fixed contact 19 due to the vertical displacement of the switch, a switch operation is performed.

At the lower end of the plunger 3, a rectangular operating portion 3a is continuously provided, and four small projections 3b are formed on the lower surface of the operating portion 3a. It is configured to contact the central movable part at four places s on both sides of the child 17. In addition, plunger 3
The operation portion 3a is guided so as to be vertically displaceable only by contact with a rib 1b formed on the case 1 side.

The seismic device according to the present invention is configured as described above. When the case 1 is stable in a horizontal posture, the plunger is normally used by the weight of the steel ball 2 stably held by the inclined guide portion 7. 3 is pushed in, the central movable part 16 of the contact plate 13 is pressed at four places s and is pushed down and displaced in parallel, and accordingly, the movable contact 18 of the contact 17 is brought into contact with the fixed contact 19 to be turned on. . In this case, the cantilever contact 17 whose free end is prevented from being further displaced downward by the contact with the fixed contact 19 is relatively bent upward and deformed by the elastic restoring force of the contact 17. Is pressed against the fixed contact 19 with an appropriate contact pressure (about 5 gf).

When vibration or impact acts on the case 1 in the above-mentioned stable state, the steel ball 2 rolls and deviates from the inclined guide portion 7 as shown in FIG. The movable portion 16 is displaced upward by the elastic restoring force of the arm 15 group, and the contact 17 is also restored horizontally,
The movable terminal 18 separates from the fixed contact 19 and is turned off.

In the above embodiment, the plunger 3
The seismic sensor that operates the steel ball 2 with the plunger 3
Can be used for various switches such as a displacement detection switch operated by an externally operated actuator and a limit switch.

[0028]

As is apparent from the above description, the following effects can be expected according to the present invention.

According to the first aspect of the present invention, even if the contact plate is made small for miniaturization, a large length of the arm formed by cutting the periphery of the contact plate can be ensured, and the arm can be secured. It is possible to operate the central movable portion continuously provided at the free end with a small load, and it is easy to configure a contact structure that can be operated with a low load while reducing the size of the whole.

According to the second aspect of the present invention, the tongue-shaped contact provided on the central movable portion can be easily elastically deformed, so that it can be operated with a low load while reducing the overall size as described above. At the same time, it can be set without making the contact pressure between the contacts excessive.

According to the third aspect of the present invention, since the movable contact is provided at the free end of the tongue-shaped contact, the operation can be performed with a low load while securing a desired low contact pressure, and the operation sensitivity is high. In addition, a stable switching operation can be performed.

According to the fourth aspect of the present invention, the central movable portion can be displaced in a stable posture by pressing the central movable portion at a plurality of points, whereby a more stable switching operation can be performed.

According to the fifth aspect of the present invention, a desired contact pressure can be ensured while miniaturization is achieved, and it is easy to construct a seismic sensor having high sensitivity.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of a seismic device using a contact structure according to the present invention.

FIG. 2 is a sectional view taken along line aa in FIG.

FIG. 3 is a vertical sectional side view of the seismic sensor.

FIG. 4 is a sectional view taken along line bb in FIG. 1;

FIG. 5 is a vertical sectional front view of the vibration sensor which has been operated to detect vibration.

FIG. 6 is an exploded perspective view of a main part.

FIG. 7 is a sectional view of a conventional example.

[Description of Signs] 1 case 2 steel ball 3 plunger 13 contact plate 15 arm 16 central movable part 17 contactor 18 movable contact 19 fixed contact

Claims (5)

[Claims] A plurality of arms extending in a circumferential direction are cut in a peripheral portion of a contact plate having a spring property, and a central movable portion supported at a central portion of the contact plate over a free end of the arm group. A contact structure wherein the central movable portion is configured to be displaceable by a pressing operation of an operating body, and a contact facing a fixed contact is formed in the central movable portion. 2. The contact structure according to claim 1, wherein the contact is formed in a tongue shape. 3. The contact structure according to claim 2, wherein a movable contact for said fixed contact is provided at a free end of said contact. 4. The contact structure according to claim 2, wherein the operating body presses the central movable portion at a plurality of locations around the contact. 5. A contact structure according to any one of claims 1 to 4, wherein:
A seismic device, wherein a pressing operation by the operating body or a release of the pressing operation is performed.