JPH07122152A - Safety switch - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a safety switch having a mechanism capable of visually confirming that the actuator is locked, that is, the door is securely locked. [Structure] The surface of the cover 11 of the operation section, which is displaced in accordance with the movement of the lock piece 51, which is a component of the mechanical lock mechanism provided in the operation section 111, and which corresponds to the unlocked / locked state. On the other hand, the display rod 8 having the upper surface 8a protruding is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety switch which is mounted on a wall surface such as an entrance / exit of a room in which an industrial machine is installed and locks the drive of the industrial machine when the door of the entrance / exit is opened.

[0002]

2. Description of the Related Art In a danger zone of a room where an industrial machine is installed, a factory, or the industrial machine itself, in order to prevent a trouble such as a worker being caught in the machine and being injured, the entrance of the room or the danger zone is prevented. It is required to provide a system to lock the drive of the machine when the door is not completely closed.

Therefore, in the safety switch, when the switch body is mounted on the wall surface around the doorway of the room and the door of the doorway is closed, the actuator fixed to this door enters the operation portion of the switch body. However, this is a switch having a structure in which the movable contact (movable piece) of the contact block is switched.

Further, this safety switch employs a lock system in which the movement of the actuator that has entered the operation portion is fixed by a mechanical lock mechanism, thereby prohibiting the opening of the door.

[0005]

By the way, according to the above-mentioned safety switch, the structure is not such that it can be confirmed whether or not the lock is surely engaged when the door is closed, and therefore the door is closed. Workers may feel anxiety when they do, and it is desired to eliminate this.

Therefore, it is an object of the present invention to provide a safety switch having a mechanism capable of visually confirming that the actuator is locked, that is, the door is locked.

[0007]

A structure for achieving the above object will be described with reference to FIGS. 1, 2 and 5 corresponding to an embodiment.
In the safety switch having a structure in which the connection contact is switched when 2 enters into the operation portion 111 of the switch body 101, the actuator 102 has a support piece whose insertion portion into the operation portion 111 supports the pressing piece 121 at the tip and both ends thereof. 122, 123, the operation portion 111 rotates in response to the entry of the actuator 102, and has stepped portions 1c, 3c and recesses 1a, 3a in which the pressing pieces 121 of the actuator are fitted on the outer peripheral surface. Plate cam 1 ... 3
And a lock piece 51 that comes into contact with the outer peripheral surfaces of the plate cams 1 ... 3 while being pressed, and when the tip of the actuator 102 reaches a predetermined position in the operation unit 111, The lock piece 51 is hooked on the step portions 1c and 3c, and the pressing piece 121 of the actuator 102 is configured to be locked by the recesses 1a and 3a of the plate cam. A display rod 8 is provided which moves in a direction intersecting with the surface of the cover 11 of the operation portion with the movement of 51, and the upper surface 8a of the display rod 8 is located at a position protruding from the surface of the cover 11 and at a position protruding from the surface. It is characterized by being configured so as to be displaceable into two positions, a non-operating position and a non-operating position.

[0008]

When the actuator 102 enters the operation portion 111, the plate cams 1 and 3 are rotated, and the rotation causes the lock pieces 51 to be positioned at the step portions 1c and 3c on the outer peripheral surface of the cam and to fall into the step portions. Therefore, the actuator 102 is locked, but when locked, the lock piece 51 moves (moves up and down) by a distance corresponding to the step between the step portions 1c and 3c. Therefore, in the present invention, the lock piece 5
Using the movement of 1, the display rod 8 is moved to a position where it is projected or a position where it is not projected with respect to the cover 11 of the operation portion 111.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, the schematic structure of the safety switch will be described with reference to FIG.

The safety switch of this example is a switch electrically connected to an industrial machine installed in a room, and is mainly composed of a switch body 101 and an actuator 102. The switch body 101 is fixed to the wall surface at the periphery of the doorway of the room. Although the actuator 102 is fixed to the door 104, the position thereof is a position facing the insertion hole 101a of the switch body, and enters the operation portion 111 of the switch body 101 when the door 104 is closed.

When the actuator 102 enters, the connection contact of the contact block (see FIG. 1 etc.) built in the switch unit 112 is switched (B contact → A contact), and the machine in the room becomes drivable. . On the other hand, when the actuator 102 is removed from the operation unit 111 by opening the door 104, the B contact is restored and the power supply to the machine is turned off.

The unit 103 mounted on the side of the switch body 101 is a solenoid unit for releasing a mechanical lock mechanism (described later) provided on the operation unit 111. In addition, the actuator 102 is
The insertion portion into the operation portion 111 is composed of a pressing piece 121 at the tip and a pair of support pieces 122 and 123 that support both ends thereof, and the tip end surface of the pressing piece 121 has a convex portion and a concave portion formed by a step portion. Pressed surfaces (for actuation) 121a, 121
It is b.

In addition to the insertion hole 101a, the switch body 101 also has an insertion hole 101b on the upper surface side of the body.
Is provided, and either the insertion hole 101a or 101b can be selected according to the situation of the installation place.

Next, the mechanism of the operating portion of the embodiment of the present invention will be described below with reference to FIGS. 1 to 3. 1 is a plan view with the cover removed, and FIG. 2 is a central longitudinal sectional view. FIG. 3 is a side view showing a state in which the cover is removed. Further, FIG. 4 is a configuration diagram of a main part of the embodiment of the present invention.

First, the operation section 111 is provided with a plate cam 1 located at the center and a pair of left and right plate cams 2 and 3 arranged on both sides of the plate cam 1. Each of these plate cams 1,
Numerals 2 and 3 are rotatably supported by a camshaft 4 independently of each other. Of these cams, the central plate cam 1 is a cam corresponding to the pressing surface 121a of the recessed portion of the actuator 102 shown in FIG. 5, and the pair of left and right integrated plate cams 2 and 3 are the actuator 10 respectively.
It is a cam corresponding to the pressing surface 121b of the convex portion 2 of FIG.
Since the plate cams 2 and 3 have the same shape, the reference numerals of the respective parts of the plate cam 2 are omitted below.

On the outer peripheral surfaces of the plate cams 1, 2, 3 are inserted holes (for actuators) 101a and 10a, respectively.
1b, corresponding to the rectangular recesses 1a, 3a and 1b,
3b is formed, and lock step portions 1c, 3c are formed at positions on the opposite side of the recesses with respect to the cam shaft 4. The cam shape of the outer peripheral surface between the step portions 1c and 3c and the recesses 1b and 3b is an arc shape with the cam shaft 4 as the center.

Further, each of the plate cams 1, 2 and 3 is formed with grooved cams 1d and 3d having a shape extending from a position corresponding to the lock step portions 1c and 3c to a position at an angle of about 90 °. A cam follower pin 12a provided at the rear end of the operation rod 12 is inserted into the groove cams 1d and 3d. In addition, the operating rod 12 is a switch portion 11.
It is a rod for switching the connection contact 2 (see FIG. 5).

On the other hand, a lock member 5 is arranged above the plate cams 1, 2 and 3. This lock member 5
Lock piece 51 and arms 52a, 52 supporting both ends thereof
b and lever pieces 53a for supporting their arm ends,
53b is an integrally formed member, and the lock pieces 51 are pressed against the outer peripheral surfaces of the plate cams 1, 2 and 3 by the elastic force of the compression coil springs 6 and 7 respectively arranged at the two left and right positions. It is configured to contact in a state.

The display rod 8 is mounted in the center of the lock piece 51, and this structure is the point to be noticed in the embodiment of the present invention. The display rod 8 is a cover 1
1 is slidably inserted into a through hole 11a bored in 1 and the lower end portion of a column 9 that supports this rod 8 is
It is inserted with a predetermined clearance into a through hole 51a formed in the lock piece 51, and the lower end of the column 9 is provided with a locking member 9a such as a stop nut.
The escape from a is restricted. Further, a compression coil spring 10 is arranged around the column 9, and with these configurations, the display rod 8 can be tilted in an arbitrary direction with respect to the lock piece 51 within a certain range, and can be compressed. The elastic force of the coil spring 10 maintains the state in which the coil spring 10 is pressed in a direction away from the lock piece 51.

In this embodiment, three plate cams 1 ... 3 are provided because the plate cams 1 ... 3 are pressed by the concave and convex pressing surfaces 121a and 121b of the actuator 102, respectively. Only when the cam follower pins 12a rotate in synchronization with each other.
It is configured such that it can move along d, and actuating plates other than the dedicated actuator 102 are inserted into the insertion holes 101a, 101b.
This is a configuration for preventing the operation unit 111 from operating even when it is inserted into.

Next, the operation of the embodiment of the present invention will be described with reference to FIGS.
Will be described with reference to. First, when the actuator 102 enters the inside of the operation portion 111 through the insertion hole 101a and the pressing surfaces 121a and 121b at the tips thereof contact the respective plate cams 1 and 3, as shown in FIGS. In addition, the lock piece 51 of the lock member 5 is in contact with the outer peripheral surfaces of the arc portions of the plate cams 1 and 3, and in this state,
The upper surface 8a of the display rod 8 projects from the upper surface of the cover 11 of the operation unit.

Then, when the actuator 102 further enters, the plate cams 1 and 3 rotate in response to this, and the rotation causes the cam follower pin 12a to be pushed forward by the grooves 1d and 3d. 12 moves forward. The rotation of the plate cams 1 and 3 causes the lock piece 51 to reach the lock stepped portions 1c and 3c and fall into the stepped portions [FIG. 2 (b), FIG. 3], after which the connection contact of the switch portion 112 is cut off. Replace At this time, the display rod 8 descends along with the displacement (falling) of the lock piece 51, and the upper surface 8a thereof is at the same level as the upper surface of the cover 11,
Or it will be in a sunk state.

On the other hand, when the solenoid unit 103 is actuated in response to the lock release signal, the lock piece 51 is lifted by the release mechanism (not shown) of this unit and disengages from the lock step portions 1c and 3c. Rod 8
When the actuator 102 is pulled out after that, the upper surface 8a of the plate 8a protrudes from the cover 11, and the operating rod 12 retracts, and the plate cams 1 and 3 rotate in the opposite directions to the tips.
2 (a) and FIG. 4 are restored.

In the above embodiment, if the display rod 8 is colored so that the upper surface 8a is the same color as the cover 11 and the side surface of the rod is different from the cover 11, the display rod 8 is in a protruding / immersed state. That is, it becomes easier to confirm whether or not the door 104 is locked, and the usability is further improved.

Here, in the above embodiment, since the lock piece 51 moves in a substantially arc shape in the process of being locked,
The inclination with respect to the cover 11 changes in the movement process,
In this example, since the display rod 8 has a degree of freedom with respect to the lock piece 51, the change in the inclination of the lock piece 51 is absorbed. Therefore, the display rod 8 operates smoothly without being caught in the through hole 11a of the cover 11 during movement.

The mounting of the display rod 8 on the lock piece 51 is not limited to the structure shown in FIG. 4, and the display rod 8 can be supported on the lock piece 51 with a certain degree of freedom. If so, it can be replaced with other common equivalent alternatives.

Further, the position where the display rod 8 is provided is not limited to the upper portion of the lock piece 51, and it can be installed at an arbitrary position of the cover 11 by using a lever or a link mechanism.

[0028]

As described above, according to the safety switch of the present invention, the safety switch is displaced with the movement of the lock piece which is a component of the mechanical lock mechanism provided in the operating portion, and is unlocked. A display rod is provided that protrudes from the cover surface of the relevant operating part according to the locked state, so the operation of the display rod allows you to visually confirm whether or not the lock was locked when the door was closed. can do. Moreover, since such a lock display system is composed of only a simple mechanical mechanism, there is no fear of malfunction, and a few
Since it can be implemented by adding about several parts, it is inexpensive at the time of practical application.

[Brief description of drawings]

FIG. 1 is a plan view showing the structure of an embodiment of the present invention.

FIG. 2 is a central longitudinal sectional view of the embodiment.

FIG. 3 is a side view of the embodiment.

FIG. 4 is a diagram showing a configuration of essential parts of an embodiment of the present invention.

FIG. 5 is a perspective view showing an example of a usage state of a safety switch.

[Explanation of symbols]

 1, 2 and 3 Plate cams 1a and 3a Recesses 1c and 3c Lock step portions 1d and 3d Groove cams 4 Cam follower pins 5 Lock members 51 Lock pieces 8 Display rods 8a Upper surface 11 Covers (Operating parts) 11a Through holes 101 Switch body 111 Operation Part 112 Switch part 102 Actuator 104 Door

Front Page Continuation (72) Inventor Masanori Nakayasu 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd.

Claims (1)

[Claims] 1. A switch main body is mounted around an entrance / exit of a room or the like in which an industrial machine is installed, and an actuator fixed to a door of the entrance / exit enters into an operation part of the switch main body when the door is closed to thereby connect a contact. In the safety switch having a switchable structure, the actuator is configured such that an insertion portion into the operation portion is composed of a pressing piece at a tip portion and supporting pieces supporting both ends thereof, and the operation portion is rotated in response to the entry of the actuator. And a plate cam having a stepped portion on the outer peripheral surface and a concave portion into which the pressing piece of the actuator is fitted, and a lock piece that comes into contact with the outer peripheral surface of the cam in a pressed state. At a time point when it has reached a predetermined position in the operation portion, the lock piece is caught on the stepped portion of the plate cam, and The pressing piece is configured to be locked in the concave portion of the cam, and the operation portion has a display that moves in a direction intersecting with the surface of the cover of the operation portion as the lock piece moves. A rod is provided, and an upper surface of the display rod is configured to be displaceable into two positions, a position protruding outside and a position not protruding through a through hole provided in the cover. Safety switch to do.