JPH08111145A - Safety switch with key - Google Patents

Abstract

PURPOSE: To provide a safety switch having a key by which double safety is expected and constitution of the whole safety device is simplified by integrally forming a key lock part operated by an operator in a room or will of the manager in the cutout switch interlocking with opening and closing of a door of the room in which a machine is arranged. CONSTITUTION: A key lock part 113 is added to the upper vicinity of a driving cam 1 to rotate by insertion of an actuator. The key lock part 113 has a lock, a rotary cam 20 added to the tip of its lock, a lock cam 16 to be displaced in the vertical direction by engaging with its cam 20 and a lock part 18 which is arranged on the lower end of its lock cam 16 and enters a notch part 1d of the driving cam 1, and when a door is locked by a key in a door closed condition, the door cannot be opened as long as it is not unlocked by key operation, and the connecting relationship of a contact point part 112 is not switched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mounted on a wall such as a doorway of a room where an industrial machine is installed, and when the door of the doorway is opened, the power supply to the industrial machine is stopped and the room is It relates to a safety switch that puts the inside into a safe state.

[0002]

2. Description of the Related Art In a danger zone of a room or a factory in which an industrial machine is installed or an industrial machine itself, there is a need to prevent the occurrence of troubles such as an operator being caught in the machine and being injured. When the doors to the doorway are not completely closed, it is required to have a system to lock the drive of the machine. 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. With the switch having a structure in which the movable contact of the contact portion is switched, the main circuit (power supply circuit to the industrial machine) is switched by such a switching operation, and the machine in the room becomes operable.

However, since the conventional safety switch does not control the opening and closing of the door itself, anyone can open and close the door. Therefore, the door is suddenly opened during the operation of the machine and the power supply of the machine is turned off. On the contrary, it was dangerous because someone could turn on the power when the door was opened and the door was opened for maintenance work. On the other hand, conventionally, a limit switch for detecting opening / closing of a door is provided on a wall surface of a room or the like, and the state of this switch is used as an on / off condition of a main circuit of mechanical equipment for the safety of workers.

[0005]

Therefore, the present invention does not require a door opening / closing sensor such as a limit switch separately from a safety switch, and integrates a locking device operated by an operator or the manager's will with the safety switch. The key issue is to provide a safety switch with a key that ensures the safety of workers and the maintenance of work.

[0006]

A safety switch with a key according to the present invention includes a drive cam which rotates in response to the entry of an actuator to be attached to a door of an entrance / exit and has a recess formed on the outer peripheral surface for engaging with the actuator. In a safety switch in which an operating rod that reciprocates according to the rotation of the drive cam and a contact portion whose connection is switched by the operating rod are housed in a single housing, the vicinity of the drive cam of the housing is expanded. When the lock lock is operated by a key in the bulged housing, the cam is provided at the tip of the lock and rotates according to the key operation, and the cam engages with the cam to reciprocate in a predetermined direction. It is characterized in that it is provided on a lock cam having a lock portion that penetrates into the cutout portion of the drive cam.

In the keyed safety switch of the present invention, a micro switch which is turned on / off according to the reciprocating motion of the lock cam can be added in the housing. In the keyed safety switch of the present invention, a pillar-shaped portion is integrally formed on the lock cam, the pillar-shaped portion is fitted into a through hole formed in the housing, and the pillar-shaped portion emerges from the outer surface of the housing according to a key operation. Can be configured.

[0008]

When the door is open, the contact for the main circuit is off and the machine cannot move. In the case of the micro switch built-in type, the switch is also off.

In the state where the door is closed but the key is not locked yet, the actuator engages with the safety switch body to rotate the drive cam, and as a result, the main circuit contact is switched on. The door can be opened and if the door is opened the drive cam will return to the return state and the main circuit contacts will turn off. However, if the micro switch is built-in and the on state of the micro switch is the condition to turn on the main circuit, the micro switch is off because it is not key-locked, and the machine still does not operate. It is ready.

In the state where the door is closed and the key is locked, the lock portion of the lock cam prevents the drive cam from returning by entering into the notch portion of the drive cam. I can't open the door when I try to open it. In the case of the micro switch built-in type, when the micro switch is turned on by the key lock, and the on state of the micro switch is a condition for turning on the main circuit, the machine becomes operable. This state is maintained until the key lock is artificially released by the key operation.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an outline of a safety switch will be described with reference to FIG. The safety switch of this example is a switch that is electrically connected to an industrial machine installed in a room, and mainly includes a switch body 101 and an actuator 102. The switch body 101 is fixed to a wall surface 104 around the entrance of the room. Further, the actuator 102 is fixed to the door 103, and when the door 103 is closed, the insertion hole 1 formed in the operation portion 111 of the switch body 101.
01a is inserted.

When the actuator 102 enters, the drive cam of the operation unit 111 rotates, the contacts of the contact unit 112 are switched, and the machine in the room becomes drivable. On the other hand, when the door 103 is opened, the actuator 102
When is removed from the operation unit 111, the power supply to the machine is turned off. A key lock unit 113 is provided near the operation unit 111.
And a key hole 114 is provided.

FIG. 2 shows a front view of the embodiment of the present invention. The entire safety switch body is housed in a housing, and the internal mechanism thereof is roughly divided into an operation section 111, a contact section 112, and a key lock section 113. The key lock part 113 is housed in a housing in which the upper part of the operation part 111 is bulged in a kamaboko shape, a key hole 114 is provided in the front thereof, and an indicator 115 for displaying a key lock state is provided on the top part of the kamaboko housing. It is provided.

FIG. 3 shows a plan view of the operating portion and the contact portion,
FIG. 4 shows the vertical cross-sectional view (cross section AB). Operation unit 11
1 is provided with a drive cam 1 located at the center and a pair of left and right drive cams 2 and 3 arranged on both sides of the drive cam 1. Each of these drive cams 1, 2, 3 has a camshaft 4
Are rotatably supported independently of each other.

Both ends of the camshaft 4 are respectively provided with the support frame 1.
It is supported by 1, 11. Further, return cam springs 5 and 5 are mounted on the cam shaft 4 between the support frame 11 and the plate cams 1 to 3.

Of the above three cams 1, 2, 3, the central drive cam 1 is a cam corresponding to the pressing surface of the central recessed portion of the actuator 102 shown in FIG. The pair of integrated drive cams 2 and 3 are cams corresponding to the pressing surfaces of the left and right convex portions of the actuator 102, respectively. The three cams 1, 2, 3 have the same shape,
As the actuator 102 enters, it rotates integrally. The reason why the drive cam is divided into three is to enhance safety so that the drive cam does not operate even if a metal piece other than the actuator, for example, a piece of plate is inserted.

On the outer peripheral surfaces of the drive cams 1, 2, 3 are formed rectangular recesses 1a, 1b corresponding to the actuator insertion holes 101a, 101b, respectively.
A groove cam 1c having a shape extending to a position at an angle of about 90 ° on the opposite side of the recesses with respect to the camshaft 4.
Are formed.

A cam follower pin 6 is inserted in the groove cam 1c. Both ends of this pin 6 are respectively attached to the support frame 1
It penetrates through the guide grooves provided in Nos. 1 and 11. The guide groove is a groove for restricting the moving direction of the cam follower pin 6, and is formed along a plane parallel to the longitudinal direction of the switch body 101. Also, on the cam follower pin 6,
The ends of the operating rod 7 are connected, and the operating rod 7 moves forward / backward as the pin 6 moves, and the contact portion 11
Switch the 2 movable contacts. A return spring 8 is provided between the operation rod 7 and the contact part partition plate. The drive cams 1, 2, 3 are provided with notches 1d in addition to the above-mentioned recesses. The cutout portion 1d is a lock portion 1 described later.
Engage with 8.

The contact portion 112 has two left and right normally closed contacts,
Two left and right normally open contacts and two movable contacts that move between the two contacts are built in, and external terminals of each contact are arranged on the upper surface. That is, the terminals 9-1 and 9-2 connected to the two normally-closed contacts that are in conduction with each other by the movable contact in the return state (door open state), and the terminals with the movable contact in the locked state are electrically connected to each other. Terminals 9-3 and 9-4 connected to two normally open contacts are provided. The external terminal 9-5 is to be connected to a micro switch described later, and is connected to the lead wire 1 from the terminals 9-4 and 9-5.
0 and 10 are connected and led to the micro switch in the key lock unit 113.

Next, the key lock portion 113 which is a characteristic part of the present invention will be described in detail. As shown in FIG. 4, a lock cam 16 that engages with the rotational movement of the cam 20 and moves in the up-down direction is provided in the housing 13 that bulges in a semi-circular shape. The lock cam 16 is slidably supported in the vertical direction by a through hole 14 provided at the top of the housing 13 and guide portions 15, 15 on the inner wall surface of the housing. A column-shaped portion 17 is integrally formed on the top of the lock cam 16, and when the lock cam 16 falls, the column-shaped portion 1 is formed.
The whole 7 is depressed inside the housing, but when it rises, it projects outside the housing. If the optical characteristics of the side surfaces of the housing 13 and the pillar portion 17 are different, for example, if the housing 13 is colored black, the top surface of the pillar portion 17 is colored black, and the side surfaces are colored white, Sometimes easy to see. This is the indicator 115. A lock portion 18 is integrally formed at the lower end of the lock cam 16, and in the closed state, the lock portion 18 falls into the cutout portion 1d of the drive cams 1, 2 and 3 to prevent the drive cam from returning.

FIG. 5 shows a view of the key lock portion 113 seen from the inside (from below). A lock 21 that can be operated from the front is provided on the front side of the housing 13, and a cam 20 is added to the tip thereof. The cam 20 is rotated by 90 ° in response to a key operation, and an operating portion 24 at the tip thereof is inserted into and engaged with an opening 19 formed in the lock cam 16. Therefore, the lock cam 16 is vertically displaced by the key operation. A micro switch 23 is provided on the inner surface of the top of the housing 13 on the back side, and the lead wires 10 and 10 are connected to the contact terminals to connect the external terminals 9-4 and 9-5 in FIG.
Have been led to. This micro switch 23 is a cam 20
It is turned on and off by the operation unit 24.

Next, the operation will be described with reference to FIGS. 4, 6, 7, 8, and 9. When the door shown in FIG. 7 is open, the internal mechanism is in the return position with the operating rod 7 in the return position, the normally closed contact is on, the normally open contact is off, and the lock cam 16 is in the raised position as shown in FIG. 6 (A). Indicator 1
15 is displayed. At this time, the outer peripheral surface of the drive cam 1 prevents the lock portion 18 from descending even if the key is operated to lock it.

FIG. 8 shows a state in which the door is closed but the key is not locked yet. The internal mechanism at this time is, as shown in FIG. 6B, the drive cam 1 is rotated by 90 ° by the insertion of the actuator 102, the operating rod 7 is advanced to the right in the figure, the normally closed contact is turned off, and the normally opened contact is opened. It was switched on, but the door can be opened by hand,
The lock cam 16 is still in the raised position and the indicator 1
15 is displayed and the contact of the micro switch is off. Therefore, if the contact and the microswitch are connected in series to form a safety circuit, the machine cannot operate.

FIG. 9 shows a state in which the door is closed and key-locked. The internal mechanism at this time is shown in FIG.
As shown in FIG.
The drive cam 1 cannot be restored because 8 has entered the notch 1d of the drive cam 1. Further, the indicator 115 disappears and the micro switch is turned on. Therefore, the door cannot be opened manually, and the normally closed contact is kept off and the normally opened contact is kept on. As a result, the machine is ready for operation if the series connection of contacts and microswitches constitutes a safety circuit.

[0025]

According to the present invention, not only is the door opening / closing and the power control of the machine in the room interlocked as in the conventional case, but a key lock portion operated by an operator or the manager's will is also provided. By operating the provided keys, work safety is further enhanced without being affected by the opening and closing of the door by others.

In the case where a micro switch is built-in, by adding these to the conditions of the safety circuit of the main circuit, even if a trouble such as fusion of the movable contact to the fixed contact occurs, it may occur. , The safety circuit is fully functioning and double safety is ensured. Moreover, since the micro switch is incorporated in the housing of the safety switch, it is not necessary to separately provide a limit switch, and it is possible to save space and cost.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a safety switch according to the present invention.

FIG. 2 is a front view of an embodiment of the present invention.

FIG. 3 is an operation unit 111 and a contact unit 11 according to an embodiment of the present invention.
It is a top view of FIG.

4 is a vertical sectional view of the embodiment shown in FIG.

5 is a view of the key lock portion of the embodiment shown in FIG. 4 as viewed from the inside.

FIG. 6 is an explanatory view of the operation of the internal mechanism of the embodiment of the present invention.

FIG. 7 is an explanatory view of the operation of the embodiment of the present invention.

FIG. 8 is an explanatory view of the operation of the embodiment of the present invention.

FIG. 9 is an explanatory view of the operation of the embodiment of the present invention.

[Explanation of symbols]

 1, 2, 3 ... drive cam 1d ... notch of drive cam 4 ... cam shaft 7 ... operation rod 9-1, 9-2 ... normally closed contact terminal 9-3, 9-4 ... Normally open contact terminal 9-5 Micro switch terminal 10 Micro switch lead wire 13 Swelling housing 16 Lock cam 17 Pillar part 18 Lock part 19 Opening 20・ ・ ・ Cam 21 ・ ・ ・ Lock 23 ・ ・ ・ Micro switch 101 ・ ・ ・ Safety switch main body 102 ・ ・ ・ Actuator 111 ・ ・ ・ Operating section 112 ‥‥ Contact point 113 ‥ Key lock section 114 ‥ Key hole 115 ‥ Indicator

Claims (3)

[Claims] 1. A drive cam that rotates in response to the entry of an actuator to be attached to a door of an entrance / exit and has a recess formed on the outer peripheral surface to engage with the actuator, and an operation that reciprocates in response to the rotation of the drive cam. In a safety switch in which a rod and a contact portion whose connection is switched by the operating rod are housed in a single housing, the vicinity of the drive cam of the housing is swollen, and a key is placed in the swollen housing by a key. A lock cam that has an operated lock lock, a cam that is provided at the tip of the lock lock and that rotates according to a key operation, and a lock portion that engages with the cam and reciprocates in a predetermined direction to enter the cutout portion of the drive cam. A safety switch with a key that is equipped with a key. 2. The safety switch with a key according to claim 1, further comprising a micro switch which is turned on / off according to the reciprocating movement of the lock cam. 3. A pillar-shaped portion is integrally formed with the lock cam, the pillar-shaped portion is fitted in a through hole formed in the housing, and the pillar-shaped portion is projected and retracted from the outer surface of the housing according to a key operation. The safety switch with key according to claim 1.