JP3486819B2 - Safety switch - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[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. For this reason, safety switches are provided at the entrances and exits of dangerous zones and the like.

In such a safety switch, the switch body is mounted on the wall surface around the doorway of the room, and when the door of the doorway is closed, the actuator fixed to the door enters the operation portion of the switch body. A switch with a structure in which the movable contact (movable piece) of the contact block is switched. With this switching operation, the circuit connection switches to the main circuit (power supply circuit for industrial machinery) side and the machine in the room operates. It becomes possible.

[0004]

By the way, according to the above-mentioned safety switch, when a door is unknowingly closed by a third person when the door is opened for maintenance and inspection of the internal industrial machine, There is a risk that the maintenance worker may be in danger because the connection circuit is switched and the industrial machine becomes operable. For this reason, workers entering the room are currently performing maintenance and inspection work while paying attention to the door, and improvement thereof is desired.

Therefore, the present invention provides a safety protection function for maintaining the operation of the internal industrial machine stopped even when the door of the room is closed when workers are in the room such as the danger zone. The intended purpose is to provide an additional safety switch.

[0006]

The present invention provides an industrial machine.
The switch body is installed around the doorway of the room where it is placed.
The actuator fixed to the door of the door is
To enter the operation part of the switch body when the
The connection circuit switches from the auxiliary circuit to the main circuit side.
With the built-in safety switch, the actuator
A lock mechanism is provided on the operation section to prevent the chute from coming off.
The unit on the switch body side (for example,
(Renoid unit), a pair of terminals with an insertion receiving structure
However, it is arranged with each of the outlets exposed to the outside.
And these terminals are connected to the main circuit
The circuit ends that are disconnected from each other are connected and
A pair of insert fittings that go through are installed corresponding to the above-mentioned pair of terminals.
Equipped with a stripped connector (plug)
Corresponds to the arrangement position of the pair of terminals of the unit.
It can be detachably attached to the unit outside.
It is configured as described above.
When mounted on the unit on the main unit side and rotated,
Make sure that the lock mechanism of the operating unit is locked.
Characterized by being made. In the present invention
And the unit on the switch body side is the lock mechanism.
It is a solenoid unit for unlocking the
Only when the solenoid of theoid unit is on
Rotation / removal of the connector attached to the unit
May be possible.

[0007]

According to the present invention, the main circuit of the industrial machine is the connector.
Since it is connected through a pair of metal fittings, this connection tool
The main circuit is reliably disconnected when removed from the container. Obey
If the connection tool is removed by using the
Indoor industrial machines are never operational. Furthermore
Then, attach the connector to the unit on the switch body side and rotate it.
When the lock mechanism of the operation unit is locked,
Since it is configured to
If so, even if the door is closed, the actuator will be locked.
Without this, if the worker is locked in the room
There is no danger of inviting itself. Further, in the present invention, the operation
Solenoid unit for unlocking the lock mechanism
The solenoid unit is equipped with a
If you want to use it to lock and unlock the lock mechanism
If the solenoid of the solenoid unit is on,
The rotation of the connector attached to the unit
If it is configured to be removable, the solenoid
It is impossible to rotate / remove the connector unless it is turned on.
Therefore, for example, if the operator mistakes the procedure, the solenoid
If you handle the connector before the
To be done. Also, while operating the industrial equipment,
Then the connection tool is disconnected and the power supply to the machine is stopped.
There is no fear of causing unexpected accidents.

[0008]

First, a schematic structure of a safety switch to which the present invention is applied will be described with reference to a perspective view shown in FIG.

This safety switch is mainly composed of a switch body 1
01 and the actuator 102,
The switch body 101 is fixed to the wall surface at the periphery of the doorway of the room. Further, the actuator 102 is fixed to the door 104, but its position is the insertion hole 101 of the switch body.
When the door 104 is closed at a position facing a, the switch body 101 enters the operation portion 111 of the switch body 101.

When the actuator 102 enters, the connection contact of the contact block built in the switch unit 112 is switched (B contact → A contact), and the machine in the room becomes operable. 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.

In this safety switch, a mechanical lock mechanism (not shown) is provided in the operation section 111, and this lock mechanism prevents movement of the actuator entering the operation section 111 (movement to the removal side). A lock system has been adopted that prevents the doors from being opened. A solenoid unit 103 is attached to the side of the switch body 101 as a device for releasing the lock mechanism.

Next, the characteristic part of the embodiment of the present invention will be described below.
It will be described with reference to the drawings. 1 is an external perspective view of an embodiment of the present invention, FIGS. 2A and 2B are views showing a main structure of the embodiment, FIG. 1A is a longitudinal sectional view, and FIG. 2B is a plan view. Further, FIG. 3 is a longitudinal sectional view showing the structure of the main part of the same. Further, FIG. 4 is a sectional view taken along line XX of FIG. 2 (b), and FIGS. 5, 6 and 7 are sectional views taken along lines AA, BB and CC of FIG. 1, respectively.

The structure to be noted in this example is, as shown in FIG. 2 (a), the top cover 13 of the solenoid unit 103.
1, a cylindrical receiving seat 132 is integrally provided, and the plug receiver 1 is inserted and arranged in the receiving seat 132.

As shown in FIG. 2B, the plug receiver 1 is provided with a pair of pin insertion holes 11 for inserting the connection pins 31 of the insertion plug 3 which will be described later, at positions facing each other with the center therebetween. In addition, a pair of plate insertion holes 12 for inserting the plate 32 of the plug 3 is provided.

The plug receiver 1 is rotatably arranged in the receiving seat 132 about its cylindrical axis, and has a flange 1a integrally formed on the peripheral edge of its upper end and a bottom screwed to the lower end. The lid 2 restricts the vertical movement of the plug receiver 1 with respect to the seat 132. Further, the rotation of the plug receiver 1 is restricted within a certain angle range.

That is, as shown in the sectional view of FIG. 5, the plug receiver 1 has a shape in which the insertion portion into the receiving seat 132 has a shape in which a pair of protrusions 13 are provided on the outer periphery of a cylinder so as to face each other. On the inner surface of the receiving seat 132, protrusions 133 are integrally formed at positions facing each other.
When each projection 13 of the plug receiver 1 hits 33,
The rotation of the plug receiver 1 is restricted. The angular range is about 9
It is 0 degrees.

Each protrusion 133 of the receiving seat 132 is provided with a lock pin 4 which can be displaced in the vertical direction, and a part of the upper end surface of the lock pin 4 is located above the pin 4 to receive the plug receiver 1. When it is located in the plate insertion hole 12 of the above, it is exposed to the outside through this insertion hole 12.

As shown in FIG. 2, each lock pin 4 is restricted from being displaced upward by a stopper 1b provided on the plug receiver 1, and is pressed toward the stopper 1b by the elastic force of the compression coil spring 4a. ing. In this state, as shown in the sectional view of FIG. 6 (a), the lock pin 4 fits into the arcuate cutout 1c provided at the lower end of each plate insertion hole 12 of the plug receiver 1, and accordingly, the lock pin 4 Four
When the plug contacts the stopper 1b, the plug receiver 1 cannot rotate.

Further, as shown in FIG. 3, the lock pin 4
Is pushed down to a position where the upper end thereof reaches the level of the lower end of the plate insertion hole 12, the lock pin 4 is disengaged from the notch 1c of the plug receiver 1, and the plug receiver 1 becomes rotatable at this point.

In the plug receiver 1, as shown in FIG. 4, the terminals 10 having the insertion receiving structure are arranged inside the respective pin insertion holes 11. This pair of terminals 10
Is connected in series between the microswitch MS1 of the main circuit CM and the connection port P4 of the main circuit CM as shown in the electric circuit of FIG. That is, in this example, the main circuit CM
The wiring L4 from the connection port P4 of the above is connected to one of the pair of terminals 10, and the other terminal 10 is connected to the terminal of the microswitch MS1 through the wiring L3.

On the other hand, as shown in FIG. 4, the plug 3 comprises a plug frame 30, a plate 32 and a pair of connecting pins 31 which are integrally provided on the plug frame 30. The plug frame 30 has a protrusion 132 provided on the receiving seat 132.
a and a groove 30a that fits into the groove 30a, so-called bayonet joint structure, which is detachable from the receiving seat 132,
It is installed by inserting it into the receiving seat 132 and rotating it,
Further, it can be removed from the receiving seat 132 in the reverse order. A handle 30b is attached to the plug frame 30. The pair of connecting pins 31 are formed by utilizing the tip portions of metal wire rods bent into a U shape, and the distance between the pair of connecting pins 31 corresponds to the arrangement relationship of the pair of terminals 10 described above.

As shown in FIG. 3, the plate 32 is used to push the lock pin 4 of the receiving seat 132 against the elastic force of the compression coil spring 4a, and to completely insert the plug frame 30 into the receiving seat 132. In this state, the lower end surface of the plate 32 is at the same level as the lower end of the plate insertion hole 12,
Or located slightly below.

Next, the internal structure of the solenoid unit 103 will be described with reference to FIGS. 2 and 7. First, at the end of this unit, the operation unit 1 of the switch body
A mechanism for mechanically releasing the lock mechanism of 11 (not shown)
Is incorporated, and the tip of the operating rod 6 of the release mechanism faces the position below the plug receiver 1. Further, the tip of a drive rod 7 of a solenoid (not shown) incorporated in this unit faces the position facing the operation rod 6, and the plate cam 5 is interposed between the two rods 6 and 7. It is arranged.

The plate cam 5 is rotatably supported by a shaft 50 whose center coincides with that of the plug receiver 1. As shown in FIG. 7, the plate cam 5 is formed with a groove cam 5a extending in an arc shape around a position different from the shaft 50. The tip end of the operating rod 6 of the release mechanism is formed in the groove cam 5a. The cam follower pin 6a provided in the section is inserted.

Further, in the plate cam 5, the cam shape of the outer peripheral surface 5b of the portion facing the groove cam 5a is an arc shape centered on the shaft 50, and the concave portion 5c is formed at the peripheral end of this portion. There is.

The plate cam 5 rotates as the plug receiver 1 rotates. That is, the bottom lid 2 of the plug receiver 1
The lower surface of the plate cam 5 is provided with protrusions 21 arranged in a V shape, and the upper surface of the plate cam 5 is provided with a protrusion 51 having a shape fitted between the protrusions 21 arranged in a H shape.
The plate cam 5 and the bottom cover 2, that is, the plug receiver 1 are interconnected by 1 and 21. In addition, such a protrusion 5
1 and 21 are provided at two locations facing each other across the center of rotation.

On the other hand, the drive rod 7 of the solenoid is retracted when the solenoid is in the excited state, and the contact pin 7a provided at the tip end thereof hits the actuators MA1 and MA2 of the microswitches MS1 and MS2, respectively. The switch switches between on and off. This operation will be described with the electric circuit shown in FIG. 8. When the solenoid S is turned on, the micro switch MS1 (B contact) of the main circuit CM.
Is turned off, and the micro switch MA2 of the auxiliary circuit CS
(A contact) turns off.

Next, the operation of the embodiment of the present invention will be described together with the operation of each part. In the description of this operation, the front refers to the leftward direction in each of FIGS. 2 to 7. First, when the insertion plug 3 is removed from the solenoid unit 103, the position of the plug receiver 1 in the rotation direction is as shown in FIGS.
It is in the state shown in (a). The position of the plate cam 5 in the rotational direction is as shown in FIG. 7A, and the outer peripheral surface 5b of the plate cam 5 is contacted by the tip of the drive rod 7 of the solenoid. It should be noted that FIG. 7A shows the state in which the solenoid is off.

Now, when the insertion plug 3 is inserted according to the receiving seat 132 in the above state, as shown in FIGS.
0, and at the same time, the lock pin 4 is pushed in by the plate 32 so that the plug receiver 1 can be rotated. After that, when the inserted plug 3 is rotated in the clockwise direction, the plug receiver 1 is rotated. Along with plate cam 5
And rotate, and the position becomes the state shown in Fig. 7 (b).

That is, as the cam plate 5 rotates, the cam follower pin 6a is pushed forward by the grooved cam 5a, the operation rod 6 advances accordingly, and the lock mechanism of the operation portion 111 of the switch body can be operated. It becomes a state.
Further, the rotation of the cam plate 5 causes the recess 5c to move to a position facing the tip of the drive rod 7 of the solenoid, whereby the regulation of the drive rod 7 is released, and the tip of the recess 5c is removed.
invade c. Therefore, in this state, the rotation of the plate cam 5, that is, the rotation of the plug receiver 1 and the insertion plug 3 is restricted, and the plug 3 cannot be removed.

Next, the door 104 is closed with the insertion plug 3 attached, and along with this, the actuator 102 is closed.
When the switch enters the operation unit 111 of the switch body, the actuator 102 is locked and
The contacts of the contact block of the switch unit 112 are switched,
As shown in the electric circuit diagram of FIG. 8, the auxiliary circuit CS is cut off and the main circuit CM is connected.

Thereafter, when the solenoid S is excited in response to the lock release signal, the drive rod 7 retracts, whereby the micro switches MS1 and MS2 are turned on / off and the main circuit CM is cut off. , The auxiliary circuit CS is ready for connection. Further, as the drive rod 7 retracts, the tip of this rod 7 comes out of the recess 5c of the plate cam 5, and the plate cam 5 becomes rotatable. Then, when the insertion plug 3 is turned in the opposite direction to the withdrawal from the receiving seat 132, the rotational position of the plate cam 5 returns to the previous state of FIG. 7 (a), whereby the lock mechanism of the operation portion 111 is released. Is released,
At this point, the actuator 102 can be removed, that is, the door can be opened.

As described above, in this embodiment, the operation unit 1
To unlock the lock mechanism of 11 and return it,
Since the movement of the drive rod 7 of the solenoid is not relevant, the operation unit 111 can be operated even when the solenoid is turned off due to some cause such as an electrical failure or a power failure in the state where the insertion plug 3 is pulled out (the state shown in FIG. 7A). The lock mechanism of does not become lockable. Therefore, as long as the insertion plug 3 is pulled out, even if an abnormality such as a power failure occurs, the worker is not locked in the room by closing the door. Moreover, even if the solenoid is turned off due to such an abnormality, the forward movement of the drive rod 7 is restricted by the outer peripheral surface of the plate cam 5, so that the micro switch MS1 of the main circuit CM.
Is never turned on, and thus the structure of this embodiment is a very safe switch having a double protection function.

Furthermore, according to this embodiment, the plug 3 mounted on the solenoid unit 103 has a structure in which it cannot be rotated or pulled out unless the solenoid is turned on. Even if the plug 3 is accidentally handled before the solenoid is turned on, its removal is prevented. In addition, there is no fear that the plug 3 will come off and the power supply to the machine will be stopped due to some cause during the operation of the industrial equipment.

Next, an example in which the present invention is applied to the case where the switch body 101 is used alone will be described. FIG. 10 is a diagram showing a configuration of the embodiment, and (a) and (b) are an external perspective view and an electric circuit diagram, respectively.

In this example, the plug portion 203 of the switch body 101 has the same plug plug 203 as in the previous embodiment.
Is detachably attached, and by removing this plug 203, as shown in the electric circuit diagram of (b), the main circuit CM
Can be shut off. Although the specific structure of the contact 210 corresponding to the insertion plug 203 is not shown, a structure similar to the structure of FIG. 4 described in the previous embodiment is adopted. However, in the case of this example, since it suffices to simply connect / disconnect the main circuit CM regardless of the lock mechanism, the configuration of the plate cam or the like as in the previous embodiment is unnecessary.

Further, in this example, since it is not necessary to particularly rotate the insertion plug 203, the structure of the plug is, for example, as shown in the bottom view of FIG. 331 ... 331 are arranged,
A structure in which two of the pin groups are short-circuited can also be adopted. In this case, by changing the combination of pins to be short-circuited, it is possible to manufacture a plurality of types of plugs having the same outer shape and different adaptive devices, that is, to number the plugs.

[0038]

As described above, according to the safety switch of the present invention, the circuit connector (plug) is detachably attached to the unit on the switch body side, and the main circuit (industrial machinery The power supply circuit to the etc.) is configured to be cut off, so even if the connecting tool is removed, even if the door is closed, the industrial machine in the room will not be in an operable state. The operator does not have to pay attention to the state of the door during maintenance and inspection in the room, and can always work in a safe state. In addition, since the connector itself forms a part of the electric path of the main circuit, the operator can visually confirm whether or not the main circuit is reliably shut off by checking whether or not the connector is attached, so that reliability is improved. high.

[Brief description of drawings]

FIG. 1 is an external perspective view showing the configuration of an embodiment of the present invention.

2A and 2B are diagrams showing the main configuration of the embodiment, in which FIG. 2A is a central longitudinal sectional view and FIG. 2B is a plan view.

FIG. 3 is a longitudinal sectional view showing the structure of the main part of the embodiment of the present invention.

FIG. 4 is a sectional view taken along line XX of FIG.

FIG. 5 is a sectional view taken along the line AA of FIG.

FIG. 6 is a sectional view taken along line BB in FIG.

FIG. 7 is a sectional view taken along line CC of FIG.

FIG. 8 is an electric circuit diagram of an embodiment of the present invention.

FIG. 9 is an external perspective view showing a schematic configuration of a safety switch to which the present invention is applied.

FIG. 10 is a diagram showing the configuration of another embodiment of the present invention, (a)
Is an external perspective view, (b) is an electrical circuit diagram

FIG. 11 is a bottom view showing the configuration of a modified example of the insertion plug of the embodiment.

[Explanation of symbols]

1 plug receiver 10 terminals (plug-in receiving structure) 11 pin insertion hole 3 plug 31 connection pin 101 Switch body 111 Operation unit 112 Switch part 103 solenoid unit 131 Top cover 132 pedestal

Continuation of the front page (56) Reference JP-A-5-217470 (JP, A) JP-A-60-44926 (JP, A) Actually opened 62-99136 (JP, U) Actually opened 62-76447 (JP , U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01H 3/16 F16P 3/10

Claims (2)

(57) [Claims] 1. A connection circuit is formed by mounting a switch main body around an entrance / exit of a room or the like where an industrial machine is installed, and an actuator fixed to a door of the entrance / exit enters the operation unit of the switch main body when the door is closed. In a safety switch with a structure that switches from the auxiliary circuit to the main circuit side,
Prevent the actuator from coming off the operation part
A lock mechanism is provided in the operation part, and a pair of terminals of the insertion receiving structure are arranged in the unit on the switch main body side with each insertion opening exposed to the outside, and each of these terminals Are connected to the circuit ends obtained by cutting the main circuit, respectively, and are electrically connected to each other.
A pair of fittings are provided corresponding to the pair of terminals.
A connecting device, which is the one of the above units.
On the outside of the unit corresponding to the position of the paired terminals,
It is also configured to be detachably attached to
Then, attach this connector to the unit on the switch body side.
The lock mechanism of the operating section is locked when it is rotated.
A safety switch characterized by being configured so that it can be locked. 2. The safety switch according to claim 1, wherein
The unit on the switch body side is the lock mechanism lock unit.
It is a solenoid unit for releasing the
Only when the unit solenoid is on
It is possible to rotate and remove the connector attached to the knit
Safety switch characterized by being.