JPS58172832A - Vibration detecting switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration detection switch suitable for use in intrusion detectors and the like.

Vibration detection switches used in intrusion detectors, etc. generally have a movable plate with a weight attached to the tip and a fixed plate that forms the switch between this movable plate. The structure is such that the switch is turned off or on by the relative vibration of the movable plate caused by the inertial force of the weight when vibration is transmitted. In order to change and adjust this detection sensitivity, an adjustment screw is provided that contacts a part of the movable plate and can change the contact force, and this adjustment screw changes the contact pressure of each contact point between the movable plate and the fixed plate. The sensitivity is adjusted accordingly.

For this reason, in conventional switches of this type, even if the movable plate and fixed plate are sealed inside the case, the adjusting screw, which is partially exposed outside the case, always comes into direct contact with the movable plate. As a result, dust and moisture can enter the area around the movable plate through the gaps between the threads of the adjustment screws, and further reach the contacts, causing poor contact or corrosion, reducing reliability. There is a problem of lowering

Further, there is a problem in that it is difficult to determine the current adjustment state (sensitivity) when adjusting using an adjustment screw.

The present invention has been made in view of the above, and has a configuration in which the movable plate is made into a magnetic structure and is housed in a sealed state, while the magnet can be moved along the movable plate from outside the sealed cover and its position can be changed. By adjusting the position of the magnet outside the sealing cover, the contact pressure at the contact points can be changed and the detection sensitivity can be adjusted. This maintains a good sealing condition, prevents the intrusion of dust and moisture, and improves the reliability of the switch. The purpose of the present invention is to provide a vibration detection switch that can increase the

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

FIG. 1 is a partially exploded perspective view of the impact detection switch of the present invention;
FIG. 2 is a cutaway plan view, and FIGS. 3 and 4 are cross-sectional views, in which each switch 1 has a resin-molded circular base 1.
2, an inner cover 3 that fits on the base 2, and an outer cover 4 that fits on top of it constitute a casing, and in particular, the internal space defined by the base 2 and the inner cover 3 is sealed. It is configured to be in a state close to .

The base 2 has a bearing 5 for an adjustment plate 19, which will be described later, in the center thereof.
is fixedly installed, and fixed boss parts 6 and 7 are respectively provided on both sides, one fixed boss part 6 supports the base end of the movable plate 8 with screws 9, and the other fixed boss part 7 supports the base end of the movable plate 8 with screws 9. A fixed plate 10 is supported by screws 11. The movable plate 8 is formed entirely into a semicircular shape using a plate spring material, and a weight 12 is integrally fixed to the tip thereof, and a movable contact 13 is provided on the upper surface of the weight. Moreover, a metal plate attracted by a magnet, that is, a magnetic plate 14 is provided integrally with the movable plate 8 between approximately half the length from the tip side of the movable plate 8, thereby giving the movable plate a magnetic structure. . Note that a terminal 15 is provided at the base end of the movable plate 8.
has been established. On the other hand, a part of the fixed plate 1o protrudes to a position above the tip of the movable plate 8, and a fixed contact 16 is provided on the lower surface of this protruding part, and a switch is provided between it and the front rotating contact 13. I'm trying to make it work. Further, a terminal 17 is provided on a part of the fixed contact 16, and a lead wire (not shown) is connected to the terminal 15 and a required electric circuit.

The inner cover 3 can be fitted onto the base 2 so as to cover the movable plate 8 and the fixed plate 10, and when fitted, the inner cover 3 can be fitted onto the base 2 so as to cover the movable plate 8 and the fixed plate 10.
and the fixing plate lO is isolated from the outside (there is a gap for drawing out the lead wires).

This inner cover 3 has a through hole 18 in the center, and when fitted, the bearing 5 is exposed and the adjustment plate 19 is rotatably supported. That is, the adjustment plate 19 has a support shaft 20 integrally formed on the lower surface of its base, and a magnet (permanent magnet) 21 is integrally held at the tip thereof. horizontally (middle cover 3
The magnet 21 can be rotated in the direction along the surface of the movable plate 8, and the magnet 21 can be moved in an arc along the middle cover 3 above the movable plate 8. The rotation angle of the adjustment plate 19 is limited by the recess 22#l formed on the upper surface of the string cover 3.

Further, the base end of the adjustment plate 19 is formed into a tapered shape so that the indicator part 2
3, and a scale 2 written on the top surface of the inner cover 3.
4 so that the rotational position of the adjustment plate 19 can be easily determined. The outer cover 4 is fitted onto the base 2 so as to cover the inner cover 3 and the adjusting plate 19, and in this case as well, the sealing performance between the outer cover 4 and the inner cover 3 is relatively good. In this case, it is preferable that the outer cover 4 be made to be easily removable so that sensitivity adjustment work, which will be described later, can be easily performed.

When the vibration detection switch 1 configured in this manner is used as a vibration detection object, for example, an intrusion detector, the base 2 is attached to a window glass by an attachment means not shown.

Next, the operation of the switch of the present invention having the above structure will be explained.

In a normal state, the movable plate 8 is in a stationary state, and the movable contact 13 formed at its tip contacts the fixed contact 16 from below, and both contacts 13 and 16 are turned on, and the detection signal supplied from the electric circuit The current is passed through the terminal 15 - movable plate 8 - movable contact 13 - fixed contact 16 - fixed plate 1G - terminal 17.

When vibration is transmitted to the base 2 in this state, the movable plate 8 is vibrated relative to the base 2 due to the inertia of the weight 12 provided at the tip, and when the tip is displaced downward, the movable contact 13 is fixed. Even if both contacts are turned off by being separated from the contact 16, the detection current is instantaneously cut off, thereby allowing vibration to be detected. Therefore, by attaching the vibration detection switch 1 to a window glass, it is possible to detect an abnormality such as an intruder breaking through the window glass.

When changing and adjusting the detection sensitivity of this vibration detection switch 1, remove the outer cover 4 and rotate the adjustment plate 19 as shown in FIGS. The position of the magnet 21 is changed. That is, when the magnet 21 is changed between the illustrated solid line position and the imaginary line position, the magnetic plate that the magnet 21 attracts through the inner cover 3, in other words, the attraction position of the movable plate 8 changes accordingly. This also allows the contact pressure between the contacts 13 and 16 to be changed. That is, when the magnet 21 is located at the tip side of the movable plate 8 as shown by the solid line in the figure and restrains the vibration of this part, the contact pressure of both contacts is increased to make the movable plate difficult to vibrate and reduce its sensitivity. Furthermore, when the magnet 21 is on the proximal end side as shown by the imaginary line, the vibration restraint at the tip is weakened, the contact pressure is reduced, the movable plate is made easier to vibrate, and its sensitivity is improved. This makes it possible to adjust switch sensitivity while maintaining the sealed state of the movable plate 8 and fixed plate 10 without removing the inner cover 3, so that dust and moisture can be prevented from entering the gap between the adjustment screws, etc. as in the conventional case. It does not penetrate into the area around the contacts, and the contact points 13.16
To prevent the occurrence of contact failure by preventing dust from entering the parts, or to prevent corrosion of contacts 13, 16, etc. and the accompanying decrease in reliability by maintaining internal moisture resistance.

Can be done.

Note that the adjustment rotation position of the adjustment plate 19 is determined by the indicator 23 and the scale 2.
4, it can be visually checked and the adjustment state can be immediately determined. Further, a click mechanism or the like may be added to stabilize the rotational position.

Here, in the above embodiment, the movable plate is formed in an arc shape, but the present invention can be similarly applied to a movable plate having a straight shape. In this case, the magnet may be configured to be able to move linearly back and forth along the movable plate.

As described above, according to the vibration detection switch of the present invention, a movable plate having a magnetic structure is held in a sealed state, and a magnet is moved along the movable plate from outside the sealed cover to increase the contact pressure between both contacts. Since we are trying to change the
It is possible to prevent dust and moisture from entering the mechanism such as the movable plate and contacts, thereby preventing poor contact and corrosion of the contacts, improving the reliability of the switch, and making it possible to immediately determine the adjustment status. It has the effect of being able to do it.

[Brief Description of the Drawings] Fig. 1 is a partially exploded perspective view of the vibration detection switch of the present invention;
FIG. 2 is a broken plan view, FIGS. 3 and 4 are cross-sectional views taken along line II and Nfl/ in FIG. 2, respectively, and FIGS. 5 and 6 are schematic plan views for explaining the action and a side view. 1... Vibration detection switch, 2... Base, 3...
Inner cover, 4... Outer cover, 8... Movable plate, 10.
...Fixed plate, 12... Weight, 13... Movable contact, 1
4... Magnetic plate, 16-... Fixed contact, 19... Adjustment plate, 21... Magnet, 23... Indicator, 24...
··scale. Figure 5

Claims (1)

[Claims] (1) A vibration detection switch comprising a movable plate supported at one end and having a weight and a movable contact at its tip, and a fixed plate having a fixed contact that forms a switch with the movable contact, in which the movable plate and the fixed The plate is sealed in a casing, and the movable plate is formed into a magnetic structure, and an adjustment plate having a magnet whose position can be changed along the movable plate is provided on the outside of the casing, and the adjustment plate A vibration detection switch 0 characterized in that the contact pressure between the two contacts can be changed by adjusting the position of the magnet and changing the position of the magnet.