JPH0635329Y2 - Limit switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of the Invention> The present invention relates to a limit switch used for various production facilities, industrial robots and the like.

<Prior art and its problems> Generally, a limit switch has a switch case with a built-in contact mechanism, a head mounted with a cam for converting a rotary motion into a linear motion, and a head mounted on the switch case. It is roughly divided into an operation lever that is pivotally connected as much as possible. This is because when the operation lever is rotationally displaced to the operating position on an object to be detected such as a work, the cam converts the displacement of the rotary shaft of the operation lever into a linear motion and the main body built in the switch case or the head. The plunger is driven and the contact mechanism is turned on by an auxiliary plunger that responds to this. That is, when the operating lever is rotationally displaced from the free position to the operating position, it turns ON.
In this state, the range of turning of the operation lever from the operation position to the operation limit position where the operation lever reaches the operation lever stop is the ON state range.

By the way, in the operating position and the operating limit position of the operating lever, the ON state is also unstable. Therefore, in general, a predetermined rotational angle range from the rotational position where the operating lever sufficiently exceeds the operating position is defined as the proper stroke range. It is a specification to do.

Conventionally, as shown in FIG. 7, the outer peripheral surface of the bearing portion 101a formed on the head 101 corresponds to a position where the operation lever 102 is sufficiently beyond the operating position and a position separated from this position by a predetermined angle. Then, the first and second protrusions 103, 10
The mark 105 formed on the base end portion of the operation lever 102
It is possible to grasp the proper stroke range of the operation lever by visually observing whether the position is between the position of the first protrusion 103 and the position of the second protrusion 104 by the rotation of the operation lever 102. It was

However, in the above configuration, since the display means including the mark 105 and the first and second protrusions 103 and 104 is exposed near the operation lever 102, it is easy to get dirty and there is a possibility that a detected object such as a work may hit and be deformed. However, in a darker usage environment, it is not easy to visually check the mark 105 and the like, and there is a drawback that it is difficult to use.

Conventionally, as a means for improving this, there has been known one in which an operation range between an operation position and an operation limit position shown in FIG. 4 is displayed by lighting a light emitting element (for example, Japanese Patent Laid-Open No. 54-1).
8078 and JP-A-56-52822).

By the way, in order to obtain the proper stroke range of the limit switch, it is important to make the proper stroke range of the operating lever and the proper stroke range of the built-in switch having the contact mechanism substantially coincide with each other. In order to obtain the above, it must be done visually, and the adjustment work is extremely difficult.

In other words, the built-in switch housed in the switch case is
It has its own proper stroke range, and when various built-in switches are incorporated in the switch case to manufacture a limit switch, it is necessary to make adjustments within the proper stroke range of the operating lever, which makes adjustment work extremely difficult. It was.

<Purpose of Invention> This invention was made to improve the above problems.
It is an object of the present invention to provide a limit switch having a simple configuration, in which the work of adjusting the proper stroke range is extremely easy and the display of the proper stroke range is highly reliable.

<Structure and effect of device> The limit switch according to the present invention includes a display window formed on the outer wall of the switch case, a light emitting element disposed in the switch case facing the display window, and a display element and the light emitting element. The shutter includes a shutter member disposed between the window and connected to the plunger, and a slit formed in the shutter member. The slit has a size for determining an appropriate stroke range of the operating lever. The range in which the slit and the display window are opposed to each other is the proper stroke range of the operation lever, and substantially matches the proper stroke range of the built-in switch, and the range from the light emitting element is Light is emitted to the display window through the slit, and the proper stroke range of the operation lever is visually confirmed by the illumination of the display window. It is characterized by being configured as follows.

According to the above configuration, the proper stroke range of the operating lever is determined by the size of the slit formed on the shutter member, and the facing range between the slit and the display window is set to the proper stroke range of the operating lever. Therefore, by adjusting the size of the slit, the appropriate stroke of the operation lever and the appropriate stroke of the built-in switch can be made to substantially match, and the appropriate stroke of any limit switch can be obtained. The stroke adjustment work is extremely easy and the configuration is simple. Moreover, the light from the light emitting element is directly cut by the shutter member, cut or passed, and the proper stroke range of the operation lever is visually recognized by the illumination of the display window. Therefore, the reliability of the display of the proper stroke range of the above-mentioned operation lever, in other words, , It is possible to improve the reliability of Rimitsutosuitsuchi.

<Description of Embodiments> Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 show an example of the limit switch according to the present invention.

In the figure, reference numeral 1 denotes a switch case, which comprises a case body 3 having a basic switch housing recess 2 and a cover 5 for opening and closing the recess opening 4. As a basic switch, a built-in switch having a built-in switch mechanism (not shown), for example, a micro switch 6 is housed in the recess 2 and is fixed to the case body 3 with screws 7, 7.

A head 9 holding a rotating shaft 8 is attached to one end of the switch case 1. Reference numeral 10 denotes an operation lever, and a roller 12 for detecting an object to be detected such as a work is rotatably attached to a shaft body 11 provided at the tip portion 10a,
The base end portion 10b side is divided into two and is fixedly fastened to the tip end portion 8a of the rotary shaft 8. As a result, the operating lever 10 is rotatably supported by the head 9. 13
Is a fastening member for the base end portion 10b of the operation lever 10.

Reference numeral 14 is a cam which is built in the head 9 and converts the rotational movement of the rotary shaft 8 into a linear movement, and 15 is a return spring which gives a return force to the operating lever 10 via the cam 14 and the rotary shaft 8. 16
Is a hollow main plunger which is held by the head 9 or the switch case 1 so as to be axially movable and driven by the cam 14 as in this example. The hollow portion of the main plunger 16 is
An auxiliary plunger 18 is retained on the shaft 17 so as to be axially movable. The auxiliary plunger 18 responds to the main plunger 16 to drive the operating rod 19 of the micro switch 6 to turn on the switch mechanism when the operation lever 10 is rotated to the operating position. Reference numeral 20 is a spring which is set in the hollow portion 17 of the main plunger 16 and absorbs the impact force of the main plunger 16 on the auxiliary plunger 18.

In the recess 2 of the case body 3, a printed wiring board 23 having a green light emitting diode 21 for displaying an appropriate stroke range of the operating lever 10 and a red light emitting diode 22 for displaying an excessive stroke is housed. Is held. Reference numerals 24 and 25 denote first and second display windows formed in the cover 5 corresponding to the light emitting diodes 21 and 22, respectively, and these display windows 24 and 25 are translucent mounted on the outer surface of the cover 5. Covered with a sex nameplate 26.

On the optical path from the light emitting diodes 21, 22 to the display windows 24, 25, a substantially fan-shaped plate-shaped shutter member 27 made of a non-translucent synthetic resin or the like is arranged so as to traverse it. It is rotatably supported by a pin 28 on the case body 3 side. Reference numeral 29 is an L-shaped connecting member, one end 29a of which is connected to the pressing body-cum-bolt 30 on the tip side of the auxiliary plunger 18, and the other end 29b is pivotally attached to the shutter member 27 through a shaft 31. Therefore, the shutter member 27 is rotationally displaced according to the stroke of the operation plunger 10, in other words, the operation stroke of the auxiliary plunger 18. As shown in FIG. 3, the shutter member 27 is provided with a first optical path control region, for example, a first slit 32 having a long hole shape. This slit 32 is provided when the operating lever 10 passes through the operating position and is rotated within the proper stroke range.
Only within this range, the light of the light emitting diode 21 is transmitted and directed toward the first display window 24. Further, the shutter member 27 is provided with a second optical path control region, for example, a second slit 33, as shown in FIG.
The slit 33 allows the light of the red light emitting diode 22 to pass therethrough toward the second display window 25 when the operating lever 10 is rotated to a position beyond the proper stroke range. In addition, 34 is a conductive spring body for wiring between the micro switch 6 side and the printed wiring board 23, 35 and 36 are screw bodies for mounting the cover 5, and 37 is a connecting member provided in the case body 3. 29 guide bodies.

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

When the operating lever 10 is in the free position shown by the solid line in FIG. 4, the light from the green light emitting diode 21 is also the red light emitting diode 22.
Since the light from is also blocked by the shutter member 27, the display through the display windows 24 and 25 is not performed.

When an object to be detected such as a work hits the roller 12 of the operating lever 10, the operating lever 10 rotates about the rotary shaft 8 in the clockwise direction from the free position shown by the solid line in FIG. By this rotational displacement of the operating lever 10, the cam 14 rotates via the rotary shaft 8 against the spring force of the return spring 15 to displace the main plunger 16 downward. When the main plunger 16 is displaced, the auxiliary plunger 18 is also displaced via the spring 20 and is displaced downward. When the operating lever 10 is further rotationally displaced and reaches the operating position shown by the alternate long and short dash line in FIG. 4, the operating rod 19 of the micro switch 6 is pushed by the auxiliary plunger 18 to be in the ON state. Even in this state, the light from the green light emitting diode 21 and the red light emitting diode 22 is in a disconnected state by the shutter member 27, and this display is not performed through the respective display portions 24 and 25.

When the operating lever 10 is further rotationally displaced from the operating position and reaches the position shown by the chain double-dashed line in FIG. 4, the main plunger is moved.
Since 16 also displaces further downward against the spring force of the spring 20, the shutter member 27 further pivotally displaces, and the first slit 32 begins to face the first display window 24. Therefore, the light from the green light emitting diode 21 is emitted by the above-mentioned slit 32.
And is displayed on the first display window 24. The light from the green light emitting diode 21 passes through the slit 32 within the proper stroke range of the operation lever 10 from the position shown by the two-dot chain line in FIG. 4 to the position shown by the three-dot chain line in the same figure. This is displayed on the display window 24. At this time, the light from the red light emitting diode 22 is blocked by the shutter member 27.

When the operating lever 10 goes beyond the proper stroke range, the light of the green light emitting diode 21 does not enter the range of the first slit 32. Therefore, the above-mentioned light is emitted from the operation lever 10 at the fourth position.
The shutter member 27 is pushed and cut to the operation limit position shown by the dotted line in the figure. At this time, since the second slit 33 faces the second display window 25, the light of the red light emitting diode 22 can pass through the second slit 33 and can be visually recognized in the second display window 25. . That is, this red light emitting diode 22
It is possible to know that the stroke of the operating lever 10 has passed the proper stroke range by visually recognizing the light.

FIG. 5 shows the relationship between the amount of displacement of the auxiliary plunger 18 and the turning angle of the operating lever 10. Further, FIG. 6 shows a relative positional relationship between the light emitting diodes 21 and 22 and the shutter member 27 at each rotational stroke position of the operation lever 10.

As is clear from these figures, if the light of the green light emitting diode 21 can be visually recognized on the display window 24, it can be confirmed that the operation lever 10 is within the proper stroke range. Moreover, in this example, if the light of the red light emitting diode 22 can be visually recognized through the display window 25, it can be understood that the operation lever 10 exceeds the proper stroke range.

Here, since the light emitting diodes 21 and 22 are inside the case body 3, there is no possibility that they will be damaged by a work or the like, and since the light from the light emitting diodes 21 and 22 indicates the turning position of the operation lever 10, The above display state can be easily visually recognized even in a dark environment.

As is clear from the above, the size of the slit 32 formed in the shutter member 27 determines the proper stroke range of the operating lever 10, and the facing range between the slit 32 and the display window 24 is set to the operating lever. By setting the stroke range to 10 and adjusting the size of the slit 10, the proper stroke of the operation lever 10 and the proper stroke of the built-in switch 6 can be substantially matched.

Therefore, even if the type of the built-in switch 6 accommodated in the switch case 1 is changed, by changing the size of the above-mentioned slit 10, a limit switch suitable for the built-in switch having its own proper stroke range can be obtained. It can be manufactured easily and easily. Moreover, since the light from the light emitting element 21 is directly cut, cut or passed by the shutter member 27, the proper stroke range of the operation lever 10 is visually recognized by the illumination of the display window 24. The reliability of the display of the appropriate stroke range can be improved.

That is, for converting the proper stroke range of the operation lever 10 into an electric signal by another switch mechanism as proposed in, for example, Japanese Patent Application No. 62-56295, and then causing the light emitting element to emit light, Due to poor contact of the switch mechanism,
The light emitting element may not emit light, and the reliability of the display of the proper stroke range of the operation lever 10 may be impaired.

However, the light from the light-emitting element 21 is transmitted to the shutter member.
In the case of directly turning on / off or passing at 27, the means for converting the proper stroke range of the operation lever 10 into an electric signal is unnecessary, and the reliability of the display of the proper stroke range of the operation lever 10 is improved, and the limit switch itself. The reliability of can be increased.

[Brief description of drawings]

FIGS. 1 and 2 are a sectional view and a front view showing an example of a limit switch according to the present invention, FIG. 3 is a perspective view showing a configuration of a main part of the limit switch, and FIG. 4 is a view showing an operating lever of the limit switch. Explanatory diagram of rotational displacement,
FIG. 5 is a diagram showing the relationship between the rotation angle of the operating lever of the limit switch and the displacement of the auxiliary plunger, and FIG. 6 is a list showing the relative positional relationship between each light emitting diode and the shutter member at each position of the operating plunger. FIG. 7 and FIG. 7 are explanatory views of the proper stroke display means in the conventional limit switch. 1 ... Switch case, 8 ... Rotating shaft, 9 ... Head,
10 …… Operating lever, 14 …… Cam, 15 …… Return spring, 16…
… Main plunger, 18 …… Auxiliary plunger, 21 …… Light emitting element, 24 …… Display window, 27 …… Shutter member, 32 …… Slit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobuhiko Sahara 1 Toyota-cho, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Sadao Kondo 3-20 Kinugahara, Toyota City, Aichi Shinmei Industrial Co., Ltd. Incorporated (72) Inventor Masanori Ishii 10 Tatedocho, Hanazono-cho, Ukyo-ku, Kyoto Prefecture Tateishi Electric Co., Ltd. References JP-A-54-18078 (JP, A) JP-A-56-52822 (JP, A) JP-A-63-224122 (JP, A) Actual development Sho-53-24474 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A built-in switch housed in a switch case and having a built-in switch mechanism; an operating lever pivotally supported by a head mounted on the switch case; and an operating lever responsive to the rotation of the operating lever. A plunger that turns on the built-in switch, a return spring that constantly gives a return force to the operation lever, a display window formed on the outer wall of the switch case, and a display window that is opposed to the display window and is arranged in the switch case. The light emitting element is provided, a shutter member disposed between the light emitting element and the display window and connected to the plunger, and a slit formed on the shutter member, the slit being provided on the operating lever. An opening is formed to have a size for determining an appropriate stroke range, and the range in which the slit and the display window face each other is set to the above-mentioned operation range. The proper stroke range of the lever is approximately the same as the proper stroke range of the built-in switch, and the light from the light-emitting element passes through the slit to illuminate the display window to set the proper stroke range of the operation lever to the above range. A limit switch, which is configured to be visually recognized by illumination of a display window.