JPS59668Y2 - small switch - Google Patents

Description

[Detailed description of the invention] This invention relates to a small switch that operates a movable iron piece by pressing a push button to open a magnetic circuit of a permanent magnet, and the leaked magnetic flux opens and closes a reed switch. It is.

Conventionally, this type of small switch has a permanent magnet 2 and a fixed iron piece 3 inserted into a recess 1a of a case 1, as shown in FIG.
A leaf spring 5 is fixed to the upper surface of the case 1, and the lower end of the push button 6 is engaged with the leaf spring 5, and terminals 7a, 7b and a reed switch 8 are provided on the front side of the case 1 in the first drawing. A case 9 (see FIG. 2) is fitted into the case 9 (see FIG. 2).

Then, by pressing the push button 6, the movable iron piece 4 is rotated in the circular direction in FIG. 1 and separated from the permanent magnet 2 (indicated by the dashed line in FIG. The reed switch 8 is opened and closed by this.

However, in the small switch with the above configuration, since the movable iron piece 4 is hinged to the corner 2a of the permanent magnet 2, the permanent magnet 2
There was a fear that the permanent magnet 2 would be damaged, especially when a strong operating force was applied to the push button 6.

This also applies to permanent magnets 2 whose attracting surfaces are coated with a thin resin.

The present invention was made in view of the above problems, and an object of the present invention is to provide a small switch whose permanent magnet is not damaged.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings showing embodiments thereof.

FIG. 3 shows the first embodiment, where 10 is a synthetic resin case;
15 is a permanent magnet inserted into the recess 11 of the case 10;
16 is a fixed iron piece.

17 is a movable iron piece whose base end 18 loosely fits into the recess 12 of the case 10, and the lower surface of the base end 18 is hinged to a convex curved surface 10a continuous with the recess 12.

The surface of the movable iron piece 17 facing the permanent magnet 15 and the base end portion 1
A coil spring 21 fixed to the lower end of the push button 20 is in contact with the lower end of the push button 20 .

Further, the upper surface of the tip end 19 of the movable iron piece 17 abuts against the stepped portion 13 of the case 10, so that the impact force of the movable iron piece 17 at the time of return is not directly transmitted to the permanent magnet 15.

A thin coating 14 is provided on the lower surface of the permanent magnet 15 in the case 10.
The permanent magnet 15 is provided integrally with the movable iron piece 17, and the attraction force with the movable iron piece 17 prevents the permanent magnet 15 from coming out downward in the figure.

It should be noted that another case equipped with a reed switch and a terminal is fitted onto the front side of the case 10 in the third drawing, as in FIG. 2.

In normal conditions, the movable iron piece 17 is attracted upward in FIG. 3 by the magnetic flux of the permanent magnet 15, and the permanent magnet 15, fixed iron piece 16, and movable iron piece 17 form a magnetic circuit, and there is almost no leakage magnetic flux, and the lead The switch is in the off state.

Here, when the push button 20 is pressed down, a moment 1~ in the counterclockwise direction in FIG. When the moment becomes larger than the moment, the movable iron piece 17 rotates in the counterclockwise direction in FIG. 3 by one arm around the base end 18.

At this time, since the base end portion 18 rolls into contact with the convex curved surface 10a, there is no fear that the convex curved surface 10a will blow out or be damaged.

The rotation of the movable iron piece 17 opens the magnetic circuit of the permanent magnet 15, and the leakage magnetic flux acts on the reed switch to turn it on.

Then, when the pressing force on the push button 20 is released, the movable iron piece 17 returns upward due to the magnetic flux of the permanent magnet 15.
As the magnetic circuit closes, leakage magnetic flux disappears, and the reed switch is turned off again.

FIG. 4 shows a second embodiment, in which a push button 23 is integrally provided with a protruding piece 24 that protrudes laterally, and a coil spring 25 whose upper end is fixed to this protruding piece 24 is attached to a fixed iron piece 26.
and the holes 26 a and 27 a of the permanent magnet 27 and the lower end of the coil spring 25 is brought into contact with the upper surface of the movable iron piece 28 . By pressing down the push button 23 , the movable iron piece 28 is pushed down and rotated in the counterclockwise direction in FIG. 4 using the convex curved surface continuous with the concave portion 30 of the case 29 as a fulcrum.

Then, by releasing the pressing blade on the push button 23, the movable iron piece 28 is attracted to the permanent magnet 27 and returns to its original position.

In this embodiment, since the point at which the movable iron piece 28 is pressed is located away from the recess 30 of the case 29, which is the fulcrum, the operating force (pushing force) of the push button 23 can be small due to the lever principle.

FIG. 5 shows a third embodiment, in which, like the second embodiment, in order to reduce the operating force of the push button 23, the permanent magnet is divided into two parts, and the notch 33 of the fixed iron piece 32 and both permanent magnets 34.3
5, the coil spring 25 is inserted between the recesses 30 of the case 29, and the point at which the movable iron piece 28 is pressed is the fulcrum.
It is set so that it is located far away from the

In addition, in the third embodiment, the same parts as in the second embodiment are given the same numbers and their explanations are omitted.

As is clear from the above explanation, according to the present invention, the end of the movable iron piece is hinged with the case, so there is no force applied to the corner of the permanent magnet as in the conventional case, and there is no risk of damage to the permanent magnet. There is no.

Moreover, since the operating force of the push button acts in a direction to separate the movable iron piece from the permanent magnet, there is no fear that the permanent magnet will chip even if a strong operating force is applied to the push button.

In particular, as the movable iron piece moves, the bottom surface of the proximal end of the movable iron piece rolls against the convex curved surface of the case, so that the load is not concentrated at only one point and the case is not damaged or chipped.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of one case of a conventional small switch, Fig. 2 is a side view of the other case, Fig. 3 and the following show the small switch according to the present invention, and Figs. , and FIG. 5 are cross-sectional views of the first embodiment, the second embodiment, and the third embodiment, respectively. 10.29... Case, 10a... Convex curved surface, 13... Step part, 15, 27, 34.35
...Permanent magnet, 16,26.32...
Fixed iron piece, 17.28... Movable iron piece, 18...
...Proximal end, 19...Distal end, 20.23
...Push button, 21.25 ...Coil spring.

Claims (3)

[Scope of utility model registration request] (1) By pressing the push button, the movable iron piece is rotated and a magnetic circuit consisting of this movable iron piece, a permanent magnet attached to the case, and a fixed iron piece is opened, and the leakage magnetic flux is In a small switch for opening and closing a reed switch, the proximal end of the movable iron piece is hinged so that its lower surface uses a convex curved surface provided on the case as a fulcrum, and the case allows the upward movement of the movable iron piece. A stepped portion is provided to prevent the upper surface of the movable iron piece from coming into contact with the permanent magnet by protruding downward from the permanent magnet, and a coil spring is interposed between the push button and the movable iron piece. Features a small switch. (2) The small switch according to claim 1, which is a registered utility model, characterized in that the permanent magnet has a through hole in its center, and the coil spring passes through the through hole. (3) A small switch according to claim 1, which is a registered utility model, characterized in that the permanent magnet has a two-part structure, and the coil spring is inserted between both permanent magnets.