JPH02297823A - Limit switch - Google Patents

Abstract

PURPOSE:To make it possible to continuously use a switch by thinning it and increase a set rotary stroke width of an operating lever by providing a second plunger to pushingly drive a push button portion of a basic switch and an auxiliary coil spring to absorb the shaft driving of a first plunger from the time when the push button portion is pushed in. CONSTITUTION:When a detected hits against a roller 15 and an operating lever 14 rotates clockwise or counterclockwise, the second plunger 18 responds thereto with the result that a push button portion 5a of a basic switch 5 is pushed in and the basic switch 5 is turned on. When the operating lever 14 further rotates, an auxiliary coil spring 21 is further compressedly deformed, and the second plunger 18 and a holding plate 20 are relatively displaced so that the shaft drive of the first plunger 8 is absorbed. As the operating lever 14 is arrangedly installed within the thickness W of a switch case 1, if is possible to continuously connect a plurality of switches as thin ones. Thereby, it is possible to use continuously connected switches by thinning them so that the rotary stroke of the operating lever can be widened; in other words, it is possible to certainly detect a detected with a large movement.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a limit switch that detects an object to be detected, such as a workpiece, using an operating lever.

<Prior art and issues> Generally, in control devices incorporating limit switches, multiple limit switches may be connected in the thickness direction, and in this case, in order to save space, etc. It is desirable to have a thin shape.For this reason, conventionally,
The thickness of the switch case has been reduced to make it thinner, while the operating lever is placed in a position where it does not protrude from both sides of the switch case in the thickness direction, that is, the operating lever is located within the thickness of the switch case. has been proposed.

By the way, in a conventional limit switch, when an object to be detected hits an operating lever supported on a rotating shaft and the operating lever is rotated by a predetermined angle, a cam or the like fixed to the rotating shaft drives the operating plunger. The push button of the basic switch is pushed in, and there is a limit to increasing the amount of rotational stroke of the operating lever, which has the disadvantage that it is difficult to detect objects with large movements, for example.

<Purpose of the Invention> The present invention has been made in order to solve the problems of the above-mentioned conventional devices, and provides a limit switch that can be used in conjunction due to its thinness and can also set a large rotational stroke amount of the operating plunger. It is intended to.

<Configuration and Effects of the Invention> The limit switch according to the present invention includes a switch case incorporating a basic switch, and a switch case that is pivotally supported by the head portion of the switch case within the thickness of the switch case, and is pivoted in a direction orthogonal to the thickness direction. a hollow first plunger that is rotatably supported within the switch case and driven by a cam portion provided on a rotating shaft of the operating lever; a return coil spring disposed within the switch case to apply a return force to the first plunger; and a push button portion of the basic switch which is held in an axially movable manner by the first plunger and is actuated by the axial displacement of the plunger. A second plunger that pushes and drives the push button, and an auxiliary coil spring that is disposed within the first plunger and absorbs the axial movement of the first plunger from the time the push button is pushed.

According to this invention, since the operating lever is pivoted on the head within the thickness of the switch case, it is possible to use multiple devices connected in the thickness direction, and in addition, the push button of the basic switch can be pushed in. Since the axial movement of the first plunger is absorbed by the auxiliary coil spring, the rotation stroke of the operating lever can be increased, and in other words, objects with large movements can be reliably detected.

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

1 and 2 are a front sectional view and a side sectional view, respectively, showing an example of a limit switch according to the present invention.

In the figure, reference numeral 1 denotes a thin box-shaped switch case made of synthetic resin or the like, which consists of a case body 2 and a head part 3 fixed to the upper end side of the case body 2. 4 has a built-in basic switch 5 such as a micro switch. 6 is a screw body for fixing the head portion 3.

A first plunger 8 having a hollow portion 8a is fitted into the upper space 7 of the case body 2 so as to be able to pivot. A restoring force is applied to the first plunger 8 between the seat body 9 fixed to the lower part of the cavity 7 and the step lO formed in the hollow part 8a of the first plunger 8. A return coil spring 11 is hung. Reference numeral 12 denotes an elastic sealing member for liquid-tightly sealing the opening 4a of the lower space 4.

Reference numeral 13 indicates a rotating shaft disposed in the head portion 3 along the front-back direction (thickness direction) of the switch case 1, and 14 indicates a rotating shaft disposed on the rotating shaft 13 within the thickness W of the switch case 1
4a is a fixed operating lever, and its tip 14b
A roller 15 that comes into contact with the object to be detected is attached via a support shaft 16 .

A cam portion 17 is formed on the rotating shaft 13 and causes the first plunger 8 to move axially when the operating lever 14 is rotated. 18 is a hollow portion 8a of the first plunger 8;
The holding plate 2 is a rod-shaped second plunger that is disposed so as to be axially movable inside the holding plate 2 that is disposed on the second step 19 of the hollow portion 8a.
0 and is held slidably so as to push the push button portion 5a of the basic switch 5 when the first plunger 8 is axially moved by a predetermined amount due to rotation of the operating lever 14. ing. Reference numeral 21 denotes an auxiliary coil spring provided between the holding plate 20 and the spring seat body 9, which controls the axial movement of the first plunger 8 when the push button portion 5 is pushed in by the second plunger 18. It is meant to be absorbed.

22 is a lid body that closes the lower end opening of the case body 2;
3 is an external lead-out cable connected to the switch 5, and 24 is a sealing resin filled in the cavity 4.

Next, the operation of the above configuration will be explained.

When the object to be detected hits the roller 15 and the operating lever 14 rotates from the free position in either the left or right direction (in the directions of arrows a and b), the cam portion 17 rotates as the rotating shaft 13 rotates, as shown in FIG. The first plunger 8 is driven, and the plunger 8 is displaced downward against the spring force of the return coil spring 11. Therefore, the second plunger 18 also pushes the push button portion 5a of the basic switch 5 in response to this, and the basic switch 5 is turned on when the operating lever 14 is in the operating position.

When the operating lever 14 further rotates, the auxiliary coil spring 21 is further compressed and deformed as shown in FIG. axial motion is absorbed. When the detected object leaves the roller 15, the first and '! The plungers 8 and 18 of J2 are returned by the spring force of the return coil spring 11 and the auxiliary coil spring 21, respectively, and the operating lever 14 is also returned to the free position.

Here, since the operating lever 14 is disposed within the thickness W of the switch case 1, it is thin and a plurality of levers can be used in conjunction.

In particular, in order to have the auxiliary coil spring 21 absorb the downward movement of the first plunger 8 from the position where the second plunger 18 pushes the push button portion 5a of the basic switch 5, the operating lever 1
In other words, the object to be detected can be detected reliably even when the movement of the object to be detected is large, and the push button part 5 of the basic switch 5 can be prevented from being damaged by excessive pushing. You can also prevent it from happening.

[Brief explanation of drawings]

FIGS. 1 and 2 are front sectional views and side sectional views showing an example of a limit switch according to the present invention, respectively, and FIGS. 3 and 4 are explanatory views of the operation of the same limit switch, respectively. 1...Switch case, 3...Head part, 5...
Basic switch, 8--First plunger, 11...
Return coil spring, 13... Rotating shaft, 14... Operating lever, 17... Cam portion, 1B... Second plunger, 21... Auxiliary coil spring. Figure 1 Figure 2 Figure 3 Figure 9J4

Claims (1)

[Claims] (1) A switch case with a built-in basic switch; and an operating lever that is rotatably supported by the head of the switch case within the thickness of the switch case and is rotatable in a direction orthogonal to the thickness direction. , a hollow first plunger that is held movably in the switch case and driven by a cam provided on the rotating shaft of the operating lever; a return coil spring that applies a return force to the plunger; a second plunger that is axially movably held by the first plunger and that pushes and drives the push button of the basic switch by the axial displacement of the plunger; 1. A limit switch comprising: an auxiliary coil spring disposed within the first plunger to absorb the axial movement of the first plunger from the time the push button section is pressed.