JPH07105778A - Safety switch contact mechanism - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a contact mechanism of a safety switch having a structure in which a contact (A contact) on a side that enables mechanical drive is turned on only when an actuator is locked by a switch body. . [Structure] The movable piece for contact connection and the stopper of the front and rear two pieces move along with the operation rod which advances when the actuator enters. Among them, the movable piece on the front side (for A contact) is moved by the stopper and the contact member. The movement is once stopped, and after that, the actuator is locked, then the stop is released and the elastic force of the intermediate spring moves forward to contact the fixed contact (A contact side), which turns on the A contact. It is configured to be

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 such as an entrance / exit of a room where an industrial machine is installed and locks the drive of the industrial machine when the door of the entrance / exit is opened. In particular, it relates to the mechanism of the contact portion of the switch.

[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, the switch body is mounted on the wall surface around the entrance of the room, and when the door of the entrance is closed, the actuator fixed to the door enters the operation portion of the switch body. This is a change-over switch having a structure in which the connection by the movable contact (movable piece) of the contact block moves from the B contact on the machine lock side to the A contact on the machine drivable side.

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 movable contact comes into contact with the A contact side before the time when the actuator entering the operation portion is locked. For this reason, the machine inside may be in a drivable state even though the door is not completely closed.

When the machine starts to be driven in such an unlocked state, when the door opens even a little due to the vibration of the machine, the machine immediately stops at that point, which is a safety aspect. Although there is no problem, stopping the machine during operation in this way is a major problem in terms of operating efficiency. Particularly, when the industrial machine is automatically controlled in a predetermined sequence, the problem is remarkable.

The present invention has been made to improve such a point, and the machine can be driven only when the door is completely closed, that is, when the actuator is locked by the switch body. Contact on the side to be in a state (A contact)
The intended purpose is to provide a contact mechanism for a safety switch that is turned on.

[0008]

A structure for achieving the above object will be described with reference to FIGS. 1, 2 and 6 corresponding to an embodiment. A contact mechanism of a safety switch according to the present invention will be described below. An operating rod 1 that moves forward in response to the entry of the actuator 102, a return spring 11 that presses the operating rod 1 toward the backward direction, and two contact connection side-by-side contacts that are aligned in the moving direction of the operating rod 1. Movable pieces 5 and 4 and the intermediate spring 12 sandwiched between the two movable pieces 5 and 4.
And the front and rear fixed contact pairs 3, 3 and 2, 2 respectively located in front of and behind the front and rear movable pieces 5, 4 and the operating rod 1, and the rod is located at the starting point of forward movement. Sometimes it comes into contact with the front surface of the front movable piece 5 and then the movable piece 4
Is connected to the fixed contact 2 on the rear side, and the rear pressing surface 1b provided on the operation rod 1 and coming into contact with the rear surface of the rear movable piece 4 during the movement of the operating rod 1 during its movement.
c, a stopper 6 that moves along with the front movable piece 5 that advances due to the contact of the rear pressing surface 1c, and two positions of a position where the advance of the stopper 6 is stopped, and a stop regulation position and a position where this is released. The movable contact member 7 and the front end portion of the contact member 7 and the operating rod 1 so as to correspond to each other, and the contact member 7 is moved from the above-mentioned restricted position to its release position as the operating rod advances. Cam 1 moving to
e and its follower 7a. The stopper 6 is stopped before the actuator is locked, and
The time at which the restriction is released is characterized by being set after the actuator is locked.

In the present invention, after the actuator is locked, the lock mechanism used in the safety switch to which the present invention is applied is locked by, for example, catching the locking claw in the groove of the plate cam. Due to the structure, the position of the insertion end of the actuator is usually set to a position slightly deeper than the lock position due to the hooking of the locking claw, and the tip of the actuator reaches the margin of insertion. It refers to the time when you did.

[0010]

The two movable pieces and the stopper are moved along with the operation rod 1 which is moved forward by the entry of the actuator, and thereafter the contact of the movable piece 4 with the fixed contact 2 is cut off. Next, in the middle of the movement, the stopper 6 is restricted from moving by the abutting member 7, and only the front movable piece 5 is temporarily stopped. After that, the intermediate spring 12 is compressed by the movement of the rear movable piece 4, and the elastic force causes the front spring 12 to move forward. The movable piece 5 is in a state of being pressed forward. At this point, the actuator is unlocked.

Next, the operating rod 1 is further advanced and the actuator is locked. In the process of moving the operating rod 1, the abutment member 7 is moved toward the side where the cam mechanism releases the restriction of movement of the stopper 6. After moving and locking the actuator, the restriction of the stopper 6 is completely released, and at this time point, the front movable piece 5 moves forward by the elastic force of the intermediate spring 12 to move to the fixed contact (A contact side). Touch 3.

[0012]

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 section 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 section 111 by opening the door 104, the B contact is restored and the drive of the machine is locked.

In this safety switch, the operation unit 111 is
A mechanical lock mechanism (not shown) that combines a plate cam, a locking claw, a spring, etc. is provided, and this lock mechanism prevents movement of the actuator that has entered the operation unit 111 (movement to the removal side). The lock system is adopted to prohibit the opening of the door.

The unit 103 mounted on the side of the switch body 101 is a solenoid unit for releasing the lock mechanism. Next, the mechanism of the contact block according to the embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

First, the contact mechanism of this example is basically
When the actuator 102 enters the switch body 101, the operation rod 1 moves forward in association with the connecting operation rod 113 of the operation unit 111, and the actuator 1
Connection is made by moving the two movable pieces 5 and 4 between the fixed contact pairs 2, 2 and 3, with the forward and backward movements such as the operation rod 1 returning to the original position by the removal of 02. The contacts are switched.

A return spring 11 is attached to the operating rod 1, and the operating rod 1 is always given a pressing force toward the starting point (returning position) of forward movement by the elastic force of the spring 11. ing.

Now, the operation rod 1 is provided with an opening 1a for holding the two movable pieces 5, 4.
Front and rear inner surfaces of the opening 1a are pressing surfaces 1b and 1c for pressing the front and rear movable pieces 5 and 4, respectively.

The two movable pieces 5 and 4 are made of a conductive material, and movable contacts 5a, 5a and 4a, 4a for contacting the front and rear fixed contacts 2 and 3 are fixed to both ends. In addition, holding members 50 and 40 made of an insulating material are integrally provided on the back surfaces of the movable pieces 5 and 4, respectively. Further, the intermediate spring 12 is sandwiched between the holding members 50 and 40.

Further, the operation rod 1 is provided with a groove 1d extending in the vertical direction from the center position of the opening 1a to the tip thereof, and the movement stopper 6 is slidably arranged in the groove 1d. . The movement stopper 6 is a member for moving along with the forward movement of the front movable piece 5 and for stopping the forward movement of the front movable piece 5 by contact with the contact member 7. A member 1f for retracting the movement stopper 6 at the time of returning is provided at the center of the tip of the groove 1d of the operation rod 1.

The contact member 7 is a lever piece whose one end is rotatably supported on an axis orthogonal to the moving direction of the operating rod 1. Rotation of the contact member 7 in the upward direction is restricted by a stop member 8 provided in the casing of the contact block, and is elastically pressed toward the stop member 8 by a torsion coil spring 13. Then, at the regulation position, the contact member 7 is disposed at a position where the regulation surface 7a at the end portion faces the regulation surface 6a of the previous movement stopper 6, and the movement of the stopper 6 causes the regulation surfaces 6a and 7a of both members to move to each other. It is configured to contact. Further, the abutting member 7 can be moved downward to a position where the tip end portion thereof does not interfere with the restriction surface 6a of the movement stopper 6. The movement is given by a cam mechanism described below.

That is, the tip end portion of the operating rod 1 is provided with cams 1e, 1e having a shape inclined (for example, about 45 degrees) with respect to the forward direction of the rod on the lower surface side, and the abutment member 7 is provided. Is provided with a cam follower 7b at a position corresponding to each cam 1e, and the forward movement of the operating rod 1 causes the cam 1e and the cam follower 7b to come into contact with each other, and the cam follower 7b moves along the cam surface,
As a result, the contact member 7 moves against the elastic force of the spring 13.

The restricting surface 6a of the movement stopper 6 and the restricting surface 7a of the abutting member 7 are centered around the rotation axis of the abutting member 7 for the purpose of smoothing the rotational movement of the abutting member 7. It is processed into a cylindrical surface.

Here, in the above structure, at the time when the front movable piece 5 that moves with the advancement of the operating rod 1 is stopped, the actuator 102 that has entered the switch body 111 is at a position where it is locked by the lock mechanism. Also, the position where the contact member 7 moves to a position where it does not interfere with the movement stopper 6, that is, the position where the stop of the movement of the front movable piece 5 is released, is slightly smaller than the position where the actuator 102 is locked. 1 is set to the advanced position.

Next, the operation of the embodiment of the present invention will be described with reference to FIGS. In addition, the vertical cross-sectional view (a) of FIG.
(c) and (a) to (c) of the horizontal cross-sectional view of FIG. 5 respectively show operation states corresponding to each other.

First, in the state shown in FIGS. 1 and 2, the operating rod 1 is located at the starting point of forward movement, and in this state, the front pressing surface 1b of the rod makes the front movable piece 5 contact the front surface. Then, the rear movable piece 4 is in contact with the fixed contact 2 on the rear side (B contact side) via the movable contact 4a by the elastic force of the intermediate spring 12.

Next, when the operating rod 1 advances due to the entry of the actuator, the rear pressing surface 1c of the rod first comes into contact with the rear surface of the rear movable piece 4, and then the movable piece 4 advances, and with this, the intermediate spring. 12 and the front movable piece 5 move forward, and the movement stopper 6 further moves forward, but the movement of the front movable piece 5 is stopped when the stopper 6 hits the contact member 7 [FIG. 4 (a), FIG. a)]. At this point, the actuator is not locked.

After this, when the operating rod 1 further advances,
The rear pressing surface 1c presses the rear movable piece 4 forward, whereby the intermediate spring 12 is compressed. At this time, the contact member 7 rotates downward as the operation rod 1 advances, and after the actuator is locked, that is, the contact between the restriction surface 7a of the contact member 7 and the restriction surface 6a of the movement stopper 6 is cut off. As shown in FIGS. 4 and 5 (b) → (c), the front movable piece 5 pops out forward by the elastic force of the intermediate spring 12, and its both ends move forward through the movable contacts 5a. The fixed contact 3 on the side is contacted, and the A contact side is turned on.

On the other hand, in the state of (c) of FIGS. 4 and 5, when the lock of the actuator is released and the actuator is pulled out from the switch main body, the operating rod 1 is retracted as the actuator is retracted. The front movable piece 5 is retracted and the contact with the fixed contact 3 is cut off. At the same time, the front movable piece 4 is retracted, the movement stopper 6 is further retracted, and the contact member 7 is returned to the original position. And
When the operation rod 1 returns to the forward starting point, the respective components return to the positions shown in FIGS. 1 and 2, and the B contact is restored by the contact of the rear movable piece 4 with the fixed contact 2 on the rear side.

In the above-described embodiment of the present invention, the movement stopper 6 is a single piece, but the present invention is not limited to this, and the present invention can be implemented even if the movement stopper is provided integrally with the front movable piece 5. Is.

Further, the moving cam of the contact member 7 and its cam follower may be arranged opposite to the positional relationship shown in FIG. 2, that is, a cam may be provided on the contact member 7 side and a cam follower on the operation rod 1 side.

Further, in the embodiment of the present invention, the contact member 7 is a rotatable lever piece. However, in addition to this, for example, a pin-shaped member which moves up and down is regulated by the spring and the cam mechanism to the regulating position of the movement stopper 6 and its position. A mechanism of moving to a position for releasing may be adopted.

[0034]

As described above, according to the contact mechanism of the safety switch of the present invention, the movable piece for contact connection and the stopper of the front and rear two sheets move in accordance with the operation rod that advances when the actuator enters. , The front movable piece (for A contact) is temporarily stopped by the stopper and the contact member, and after the actuator is locked, the front movable piece moves forward by the elastic force of the intermediate spring to move to the fixed contact (A contact side). ), The A contact is turned on only when the actuator is locked to the switch body. As a result, it is possible to solve the problem that the internal machine can be driven even though the door is not completely closed.

[Brief description of drawings]

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

[Fig. 2] Similarly, a vertical sectional view

FIG. 3 is an exploded perspective view showing an operating rod 1, a movement stopper 6 and a contact member 7 of the embodiment in an extracted manner.

FIG. 4 is an explanatory view of the operation of the embodiment of the present invention.

FIG. 5 is an explanatory view of the same operation

FIG. 6 is a perspective view showing an example of a usage state of a safety switch.

[Explanation of symbols]

 1 Operation Rod 1b, 1c Pressing Surface 1d Groove 1e Cam 2,3 Fixed Contact 4 Rear Movable Piece 5 Front Movable Piece 4a, 5a Movable Contact 6 Moving Stopper 6a Restricting Surface 7 Abutting Member 7a Restricting Surface 7b Cam Follower 11 Return Spring 12 Intermediate Spring 13 torsion coil spring 101 switch body 111 operation unit 112 switch unit 102 actuator 104 door

Claims (1)

[Claims] 1. A switch main body is mounted in the vicinity of 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 switches the connection contact by entering the switch main body by closing the door. ,
A contact mechanism of a safety switch having a lock mechanism for the actuator that has entered, an operating rod that moves forward in response to the entry of the actuator, a return spring that presses the operating rod in a backward direction, and the operation described above. Two movable pieces for contact connection arranged in the front-rear direction along the moving direction of the rod, an intermediate spring sandwiched between the movable pieces, and fixed contact pairs located in front of and in the rear of the front and rear movable pieces, respectively. A front pressing surface that is provided on the operation rod and contacts the front surface of the front movable piece to connect the rear movable piece to the fixed contact on the rear side when the rod is located at the start point of the forward movement. And a rear pressing surface that is provided on the operation rod and comes into contact with the rear surface of the rear movable piece in the middle of its movement when the rod advances, and moves with the front movable piece that advances due to the contact. Stopper, a stopper member that stops the forward movement of the stopper, and is movable to two positions, that is, a stop restriction position and a position where the stopper is released, and the stopper member and the front end portion of the operation rod, respectively. The actuator is provided with a cam and a follower for moving the contact member from the regulation position to the release position as the operation rod advances, and the actuator is locked when the stopper is stopped. A contact mechanism for a safety switch, which is set before and at the time of releasing the restriction after the actuator is locked.