JPH0151006B2 - - Google Patents

Description

[Detailed Description of the Invention] Switches that operate using a spring-biased snap action have a fast opening/closing speed and have a very large rated current capacity, making them ideal for use in power plants, large machine tools, etc.
They are often used as limit switches in various valves, etc., but if they malfunction, it may lead to a major accident, so they are required to operate reliably.

The present invention relates to a snap-action switch that has a more reliable snap-action than conventional switches of the same type, and will be specifically described below with reference to the accompanying drawings.

FIGS. 1 and 2 show an example of a snap-action switch according to the present invention.
The front snap action part shown in FIG. 1 and the second
They are separated by the switch section on the rear side shown in the figure, and both are
They are connected by a drive shaft 3 passing through the center of the substrate 2 so that they can operate simultaneously. 4 is a side plate of the box body 1.

First, the snap action part, that is, the board 2
The front part will be explained.

In FIG. 1, in the lower part of the box body 1 in FIG. A swinging arm 6 in the shape of a rectangular tube with a bottom is fitted therein.

Upward U-shaped grooves 7 (the rear U-shaped grooves are not shown) are cut in the upper portions of both the front and rear surfaces of the swinging arm 6, and a bearing 8 can freely slide up and down in both U-shaped grooves 7. is mated to.

A center shaft 10 of a roller 9 facing in the front-rear direction is pivotally supported on the upper part of the bearing 8, and the bearing 8 and the roller 9 are urged upward by a compression spring 11 installed inside the swing arm 6. ing.

The central upper part of a substantially horizontal rocker 12 is fitted into the front part of the drive shaft 3. An arcuate surface 13 concentric with the swing shaft 5 is formed at the center of the lower surface of the rocker 12, and both ends thereof protrude slightly downward in an arc shape 13a, and then have a generally horizontal surface 13b.
It is connected to. The roller 9 has this arcuate surface 1
It is in pressure contact with 3.

Upper ends of a pair of left and right latches 14a and 14b facing each other with the rocker 12 in between are pivotally attached to the base plate 2 above the left and right sides of the drive shaft 3 with pins 15, 15, and the side plates 4 of the box body 1 It is biased inward by left and right compression springs 16a and 16b provided between.

On the opposing surfaces of both latches 14a, 14b, from above, first step portions 17a, 17b, second step portions 18a, 18b, and inwardly bent portions 19a, 19b.
is provided.

FIG. 1 shows a state in which the swinging arm 6 swings to the left by operating a lever 20 detachably attached to the swinging shaft 5. Press the part 19a to release the latch 14a.
It is swung to the left against a spring 16a and is brought into pressure contact with a left stopper 21a provided inwardly projecting from the side plate 4 of the box body 1.

At this time, the roller 9 rides on the protrusion continuing to the left of the arcuate surface 13 of the rocker 12 and tilts the rocker 12 toward the upper left.
The left and right corner portions 12a and 12b of the upper surface engage with a first step 17a of the left latch 14a and a second step 18b of the right latch 14b, respectively.

FIG. 2 shows the switch part when the snap action part is in the above-mentioned state, and 22 is
An electrically insulating substrate fixed to the rear surface of the substrate 2, 2
Reference numeral 3 designates an operating arm made of an electrically insulating material, which faces substantially in the vertical direction, and whose center is fitted onto the drive shaft 3 so as to swing together with the rocker 12.

Support metal fittings 2 fixed to both upper and lower ends of the operating arm 23
A pair of left and right support plates 26, 26 facing in the front-rear direction, parallel to each other, and biased in a direction away from each other by a compression spring 25 are attached to the support plate 4 so as to be slidable left and right. There is. A movable contact 27 (the rear movable contact is not shown) is attached to the front and rear ends of the outer surface of each support plate 26, respectively.

A fixed contact 28 is provided on the insulating substrate 22 at a location facing each of the movable contacts 27, and a mounting bracket 29 is provided.
The mounting bracket 29 is fixed via the connecting screw 3.
0.

FIG. 2 shows a state in which the actuating arm 23 is tilted toward the upper left in the figure, and the upper left contacts 27 and 28 and the lower right contacts 27 and 28 are in pressure contact.

In this state, by operating the lever 20,
When the swinging arm 6 is swung to the right in FIG. 1, the left latch 14a is swung slightly to the right by the bias of the left spring 16a, as shown in FIG. , is pressed against the left side of the rocker 12, and the roller 9
The spring 11 rolls toward the neutral point A, which is the center of the arcuate surface 13, while slightly elongating the spring 11.
While compressing the rocker 12, the rocker 12 rolls toward the protrusion 13a following the right end of the arcuate surface 13, applying a counterclockwise rotational force to the rocker 12.

At this time, the upper right side of the swinging arm 6 comes into contact with the bent portion 19b of the right latch 14b and presses it to the right, so that the latch 14b gradually moves against the right spring 16b. Swinging to the right, Rocker 1
2 right corner 12b and the second step 18 of the latch 14b
Gradually reduce the engagement of b.

Next, the swinging arm 6 further swings the right latch 14b to the right to bring it into pressure contact with the right stopper 21b of the box body 1, and also releases the engagement between the latch 14b and the locker 12. Although not shown in the drawings, the rocker 12 rapidly rotates counterclockwise around the drive shaft 3, and the left and right corners 12a, 12b of the rocker 12 respectively lock the left latch 1.
4a and the first step 17b of the right latch 14b.

Therefore, the actuating arm 23 of the switch part that is integrally connected to the rocker 12 swings in the direction of the arrow (clockwise in FIG. 2), and the upper right contacts 27 and 28 and the lower left contacts 27 and 28 are in pressure contact. do.

In the snap action section of a similar conventional switch, as shown by the imaginary line 13' in Fig. 3,
The rolling surface of the rocker that the roller 9' comes into contact with was a flat surface, but in the present invention it is an arcuate surface 13, so the dead center on the rolling surface 13' is the same as the dead center A of the arcuate surface 13. However, compared to when the roller 9' rolled sideways on the flat rolling surface 13',
When the roller 9 rolls on the arcuate surface 13 to the protrusion A, the spring 11 is compressed more strongly.

Therefore, when the same spring 11 is used, the switch of the present invention can apply a large rotational force to the rocker 12, so the switch can be opened and closed quickly and reliably, and the rated current capacity is also increased. do.

[Brief explanation of drawings]

FIG. 1 is a front view of an embodiment of the switch of the present invention with the cover removed, FIG. 2 is a rear view of the switch, and FIG. 3 is a front view showing the snap action of the switch of the present invention. It is an enlarged view of the part. 1... Box body, 2... Board, 3... Drive shaft, 4...
... Side plate, 5 ... Swing shaft, 6 ... Swing arm, 7 ... U
Groove, 8... Bearing, 9... Roller, 10... Center shaft, 11... Compression spring, 12... Rocker, 13
...Arc-shaped surface, 13a...Protrusion (part), 14...Latch, 15...Pin, 16...Compression spring, 17...
...First step part, 18... Second step part, 19... Inward bending part, 20... Lever, 21... Stopper, 22
... Insulating board, 23 ... Operating arm, 24 ... Supporting metal fittings, 25 ... Compression spring, 26 ... Support plate, 27 ...
Movable contact, 28... fixed contact, 29... mounting bracket, 30... connection screw.

Claims (1)

[Scope of Claims] 1. A rocking arm whose lower end is pivotally connected to a substrate and is rocked by operating a lever, and whose upper end is fitted with a roller with elastic force applied in a radial direction by a spring; The center part is fixed to a drive shaft which is oriented generally horizontally and is pivoted above the swinging arm on the base plate, and has an arcuate surface indented in the center of the lower surface and an arcuate downward protrusion continuing at both ends of the drive shaft. and a rocker to which a rotational force about a drive shaft is applied by the rollers being in rollable pressure contact with the lower surface, and an upper end of the rocker is pivotally connected to a substrate so as to be left and right opposite to each other with the rocker in between, The first step section and the second step section are biased inwardly by a spring and are provided on opposing surfaces in order from above. A pair of left and right latches engage with both ends of the rocker, and both bending parts are located on both left and right sides of the upper part of the swinging arm, and a switch part that is opened and closed by the rotation of the drive shaft. Snap action switch.