JP2008047349A - Cam mechanism for switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cam mechanism for a switch with which a movable part of a switch is in stable contact, with derailment of the movable part prevented, and with reliability of the switch improved. <P>SOLUTION: A first rotating cam plate 21 with a first notched groove 22 at an outer periphery part, and a second rotating cam plate 26 with a second notched groove 27 at an outer periphery part with a long hole 26b penetrated, are fixed by a setscrew 17 inserted into the long hole 26b at a position where the first notched groove 22 and the second notched groove 27 are overlapped. A width W3 of the outer periphery part of the first and the second cam plates 21, 26 except the first and the second notched grooves 22, 27 is to be formed the same as or more than a width W1 of a roller 7 of the microswitch 1. With this, the roller 7 is set in stable contact with the outer peripheries of the first and the second rotating cam plates 21, 26 to improve reliability of ON/OFF control of the microswitch 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a switch cam mechanism in which a movable portion of a switch is brought into contact with an outer peripheral portion of a rotary cam plate to control ON / OFF of the switch.

  Conventionally, in the microswitch 1 shown in FIGS. 5 to 7, a plurality of terminals 3 for signal extraction protrude from the upper part of the switch body 2, and the fixed contacts 4 are provided at the lower part. The base end of the movable lever 5 is supported at the lower corner of the switch body 2 so as to be rotatable around the shaft portion 6, and the movable lever 5 is in contact with and away from the fixed contact 4. A roller 7 is rotatably supported at the tip of the movable lever 5, and the roller 7 is urged toward the cam mechanism 10 by a return spring (not shown) provided on the shaft portion 6 of the movable lever 5. .

The cam mechanism 10 includes a first rotating cam plate 11, a second rotating cam plate 15 that is coaxially stacked on the first rotating cam plate 11, and rotates together with the first rotating cam plate 11. It is composed of
An arc-shaped first notch groove 12 is formed in the outer peripheral portion of the first rotating cam plate 11, and a circular cylindrical body 13 is formed in the central portion of the first rotating cam plate 11 in the second rotation. It protrudes coaxially on the cam plate 15 side. A metal shaft (not shown) is fitted into and fixed to the center hole 14 of the circular cylinder 13 so that the first rotating cam plate 11 is rotatable.

In the first rotating cam plate 11, a pair of receiving holes 11 a into which a set screw (described later) is screwed are formed at positions facing each other across the center hole 14.
A central hole 15a is formed at the center of the second rotating cam plate 15, and the circular cylinder 13 is fitted and inserted into the central hole 15a. A pair of elongated holes 15b extending in the rotation direction of the second rotating cam plate 15 is formed.

An arc-shaped second notch groove 16 is formed in the outer peripheral portion of the second rotating cam plate 15, and the first rotating cam plate 11 and the second rotating cam plate 15 are separated from each other by the first notch. The groove 12 and the second notch groove 16 are assembled and fixed by a set screw 17 inserted through the elongated hole 15a so that the groove 12 and the second notch groove 16 overlap each other.
The roller 7 of the micro switch 1 travels on the outer periphery of the first and second rotating cam plates 11 and 15 including the first and second cutout grooves 12 and 16, and the movable lever 5 is connected to the fixed contact 4. By making contact and separation, ON / OFF control of the microswitch 1 is performed.

In the cam mechanism 10 having such a configuration, the assembly position of the second rotary cam plate 15 with respect to the first rotary cam plate 11 is appropriately changed in the rotation direction by using the long hole 15b, and the first notch groove The overlapping position of 12 and the second notch groove 16 is adjusted. As a result, the cam shape is changed, and the ON / OFF switching timing of the microswitch 1 can be appropriately changed according to the purpose of use. In addition, the thing similar to such a prior art is disclosed by the patent document 1 shown below.
Japanese Patent Laid-Open No. 2000-133308

  However, as shown in FIG. 8, the cam mechanism 10 is configured by superimposing two first and second rotating cam plates 11 and 15, and therefore the first notch groove 12 and the second rotation At the position where the cam plate 15 overlaps and the position where the second notch groove 16 and the first rotating cam plate 11 overlap, the roller 7 is one of the first and second rotating cam plates 11 and 15. It will run in contact with the outer periphery. In this case, since the width W2 of the first and second rotating cam plates 11 and 15 is set to substantially half of the width W1 of the roller 7, the running of the roller 7 becomes unstable.

  Accordingly, when the micro switch 1 is used repeatedly, the rigidity of the shaft portion 6 and the movable lever 5 is reduced, or when the vibration or external force is applied, the roller 7 is tilted or travels in the worst case. There is a risk of so-called wheel disengagement from the rotating cam plates 11 and 15. As a result, the certainty of contact between the fixed contact 4 and the movable lever 5 is impaired, so that the ON / OFF control of the microswitch 1 is deteriorated and the reliability thereof is lowered.

  The technical problem of the present invention has been made in view of the circumstances as described above, and the object thereof is to stably contact the movable part of the switch and prevent the movable part from being removed. It is an object of the present invention to provide a cam mechanism for a switch that can improve reliability.

  In order to achieve the above object, the invention according to claim 1 is characterized in that a first rotating cam plate having a first notch groove on the outer peripheral portion and a long hole penetrating the plate thickness are extended in the rotation direction. And a second rotating cam plate having a second notch groove having the same radius of curvature as the first notch groove on the outer peripheral portion, are arranged coaxially, and the first rotating cam plate and the second notch The rotating cam plate is fixed by a set screw inserted into the elongated hole at a position where the first notch groove and the second notch groove overlap, and the movable part of the switch is the first and the second notches. In the switch cam mechanism that is brought into contact with the outer peripheral portion of the second rotating cam plate and performs ON / OFF control of the switch, the first and second notches of the first and second rotating cam plates The width of the outer periphery excluding the groove is equal to or wider than the width of the movable part of the switch. Characterized in that made the.

According to a second aspect of the present invention, in the first aspect of the invention, a circle directed to the second rotating cam plate side is provided on an outer peripheral portion of the first rotating cam plate excluding the first notch groove. An arc-shaped projecting portion was formed, and an arc-shaped projecting portion toward the first rotating cam plate was formed on the outer peripheral portion of the second rotating cam plate excluding the second notch groove. It is characterized by.
According to a third aspect of the present invention, in the first or second aspect of the invention, the pair of elongated holes are respectively disposed at positions facing each other across the rotation center of the second rotating cam plate. Features.
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the movable portion of the switch is a roller that is rotatably supported by a tip portion of a movable lever of the microswitch. Features.

  According to the present invention, the outer peripheral portion excluding the first and second notched grooves of the first and second rotating cam plates is formed to be wider than the width of the movable portion of the switch. The movable portion of the switch can stably come into contact with the outer peripheral portions of the first and second rotating cam plates to avoid wheel removal. Therefore, the reliability of the switch ON / OFF control can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, with the same reference numerals given to the same components as those of the conventional example.
FIG. 1 is a front view showing an embodiment of a switch cam mechanism of the present invention, and FIG. 2 is a perspective view of the switch cam mechanism. FIG. 3 is an exploded perspective view of the cam mechanism.

  Here, the microswitch 1 shown in FIGS. 1 and 2 is the same as the conventional example shown in FIGS. That is, the microswitch 1 has a plurality of terminals 3 for signal extraction projecting from the upper part of the switch body 2, a fixed contact 4 provided at the lower part, and a movable lever 5 at the lower corner of the switch body 2. The base end of the movable lever 5 is supported so as to be rotatable about the shaft portion 6, and the movable lever 5 contacts and separates from the fixed contact 4. A roller 7 is rotatably supported at the tip of the movable lever 5, and the roller 7 is biased toward the cam mechanism 20 by a return spring (not shown) provided on the shaft 6 of the movable lever 5. ing.

1 to 3, the cam mechanism 20 includes a first rotating cam plate 21 and a second rotating cam plate 26 having the same diameter as the first rotating cam plate 21. The rotary cam plate 21 and the second rotary cam plate 26 are arranged on the same axis and are rotated together.
A first notch groove 22 is formed in an arc shape in a predetermined portion of the outer peripheral portion of the first rotating cam plate 21, and the first notched groove 22 of the outer peripheral portion of the first rotating cam plate 21 is formed. An arc-shaped projecting portion 25 directed toward the second rotating cam plate 26 side is formed in a wider portion so as to have the same width as the roller 7 of the microswitch 1 in the removed portion.

  Further, a cylindrical body 23 having a flat surface on both sides of the outer wall is provided on the central portion of the first rotating cam plate 21 so as to protrude coaxially on the second rotating cam plate 26 side. The metal shaft (not shown) is fitted and fixed to make the first rotating cam plate 21 rotatable.

A central hole 26a passes through the central portion of the second rotating cam plate 26, and a cylindrical body 23 is fitted into the central hole 26a. The second rotating cam plate 26 is formed with a pair of elongated holes 26b penetrating the plate thickness at positions facing each other across the center hole 26a. The elongated holes 26b are formed in the second rotating cam plate 26. It extends in the direction of rotation.
A set screw 17 is individually inserted into the pair of long holes 26b via a washer 29, and a pair of receiving holes 21a into which the set screw 17 is screwed are formed in the first rotating cam plate 21. 23 are formed at positions facing each other across 23.

  A second notch groove 27 having the same radius of curvature as the first notch groove 22 is formed in an arc shape in a predetermined portion on the outer periphery of the second rotating cam plate 26. An arc-shaped projecting portion 28 directed to the first rotating cam plate 21 side is provided at a portion of the outer peripheral portion of the second rotating cam plate 26 excluding the second notch groove 27. It is formed wide so as to have the same width as the roller 7. Such overhang portions 28 are formed with the same radius of curvature as the overhang portions 25, and the overhang portions 28 and the overhang portions 25 are alternately arranged in the circumferential direction of the cam mechanism 20.

The first rotating cam plate 21 and the second rotating cam plate 26 are assembled at a position where the first notch groove 22 and the second notch groove 27 overlap with each other, and a set screw for inserting the elongated hole 26b. 17 is fastened and fixed.
In this case, the assembly position of the second rotating cam plate 26 can be changed in the rotational direction by using the long hole 26b. That is, the overlapping position of the first notch groove 12 and the second notch groove 16 can be adjusted, and a desired cam shape can be obtained. Thereby, the ON / OFF switching timing of the microswitch 1 is appropriately changed according to the purpose of use.
Further, since the long holes 26b are formed in a pair and are arranged at positions facing each other across the center hole 26a of the second rotating cam plate 26, the second rotating cam plate 26 is formed of the first rotating cam plate 26. It is firmly fixed to the plate 21 and reliably prevents the second rotating cam plate 26 from being displaced in the rotational direction.

  In the cam mechanism 20 having such a configuration, first, the second rotating cam plate 26 is moved in the rotational direction using the long hole 26b, and the first notch groove 22 and the second notch groove 27 overlap. The position is adjusted. Thereafter, the roller 7 of the micro switch 1 is brought into contact with the outer peripheral portions of the first and second rotating cam plates 21 and 26.

  When the first and second rotating cam plates 21 and 26 rotate in this state, the roller 7 travels on the first and second rotating cam plates 21 and 26. In this case, since the widths of the overhang portions 25 and 28 are formed to be the same width as the roller 7, the roller 7 stably travels on the outer peripheral portions of the first and second rotating cam plates 21 and 26. . Accordingly, since the movable lever 5 is reliably brought into and out of contact with the fixed contact 4, the accuracy of the ON / OFF control of the microswitch 1 is improved, and the reliability of the switch function is improved.

  Thus, in this embodiment, as shown in FIG. 4, the overhang portions 25 and 28 are formed on the outer peripheral portions of the first and second rotating cam plates 21 and 26, and the width W 3 is set to the microswitch 1. By making the same size as the width W1 of the roller 7, the roller 7 comes into stable contact with the outer peripheral portions of the first and second rotating cam plates 21 and 26. As a result, the roller 7 can stably travel on the outer peripheral portions of the first and second rotating cam plates 21 and 26 without removing the wheel, thereby improving the reliability of the ON / OFF control of the microswitch 1. be able to.

  The embodiment of the present invention has been described in detail above, but the present invention is not limited to the above-described embodiment, and the scope does not depart from the spirit of the invention described in the claims of the present invention. Thus, various changes can be made.

For example, in the present embodiment, the outer peripheral portions of the first and second rotating cam plates 21 and 26 are formed to have the same width as the width W1 of the roller 7 of the microswitch 1 by forming the overhang portions 25 and 28. However, if the overhang portions 25 and 28 are formed wider than the width W1 of the roller 7, the roller 7 travels in a more stable state, and the ON / OFF control reliability of the microswitch 1 is further improved.
Further, the rotary cam plates are not limited to the first and second rotary cam plates 21 and 26, and other rotary cam plates having different shapes can be selectively recombined, whereby cam mechanisms having various cam shapes can be obtained. Easy to get.

It is a front view of the cam mechanism for switches concerning one embodiment of the present invention. It is a perspective view of the cam mechanism for switches of FIG. FIG. 3 is an exploded perspective view of the cam mechanism shown in FIG. 2. It is a figure explaining the relationship between the width | variety of the rotating cam board (overhang | projection part) shown in FIG. 2, and the width | variety of a roller. It is a front view of the conventional switch cam mechanism. FIG. 6 is a perspective view of the switch cam mechanism of FIG. 5. FIG. 7 is an exploded perspective view of the cam mechanism shown in FIG. 6. It is a figure explaining the relationship between the width | variety of the rotating cam board shown in FIG. 6, and the width | variety of a roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Micro switch 4 Fixed contact 5 Movable lever 7 Roller 17 Set screw 20 Cam mechanism 21 1st rotation cam board 22 1st notch groove 23 Cylindrical body 24, 26a Center hole 25, 28 Overhang part 26 2nd rotation cam Plate 26b slot 27 second notch

Claims (4)

A first rotating cam plate having a first notch groove on the outer peripheral portion and a long hole penetrating the plate thickness are extended in the rotation direction, and the same radius of curvature as the first notch groove is provided on the outer peripheral portion. A second rotating cam plate having a second notch groove is coaxially arranged, and the first rotating cam plate and the second rotating cam plate are arranged in the first notch groove. At the position where the second notch groove overlaps, it is fixed by a set screw inserted through the elongated hole, and the movable part of the switch contacts the outer peripheral part of the first and second rotating cam plates so as to be able to return. In the switch cam mechanism that performs ON / OFF control of the switch,
The width of the outer peripheral portion excluding the first and second cutout grooves of the first and second rotating cam plates is formed wider than the width of the movable portion of the switch. The cam mechanism for the switch.   An arc-shaped projecting portion toward the second rotating cam plate is formed on an outer peripheral portion of the first rotating cam plate excluding the first notch groove, and the second rotating cam plate 2. The switch cam mechanism according to claim 1, wherein an arc-shaped projecting portion directed toward the first rotating cam plate is formed on an outer peripheral portion excluding the second notch groove.   3. The switch cam mechanism according to claim 1, wherein the pair of elongated holes are respectively disposed at positions facing each other across the rotation center of the second rotating cam plate.   The switch cam mechanism according to any one of claims 1 to 3, wherein the movable portion of the switch is a roller rotatably supported by a tip portion of a movable lever of the microswitch.

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