JPH1069831A - Safety switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small safety switch with high precision in safety. SOLUTION: A safety switch is miniaturized with one plate cam 1 which is rotated with the entry of an actuator into an operation part 111 to move the operating rod 6 of a switch part. Locking plates 2, 3 are arranged at the side of the plate cam 1 to form a locking mechanism which restricts the rotation of the plate cam 1. Only when the actuator is entered therein, the plate cam 1 is unlocked from the locking plates 2, 3 and then rotated so that the operation part can be prevented from being actuated by others than the specified actuator.

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 such as an entrance of a room where an industrial machine is installed, and for stopping power supply to the industrial machine when the door of the entrance is opened. About.

[0002]

2. Description of the Related Art In a danger zone of a room in which an industrial machine is installed, a factory, or an industrial machine itself, in order to prevent a trouble such as an operator being caught in the machine and being injured, the room or the danger zone is set. When the doorway is not completely closed, it is required to provide a system for locking the drive of the machine.

[0003] As such a lock system, conventionally,
A method has been adopted in which a limit switch is provided in a sliding portion of a door, and power is supplied to industrial machines in a room only when the closed state of the door is detected by the limit switch.

However, according to such a system, by operating the actuator (intercept) of the limit switch without closing the door, it becomes possible to operate the machine in the room. I can't say.

Therefore, the present applicant has already proposed a safety switch having a structure in which such a malfunction is prevented (Japanese Patent Laid-Open No. 6-76674). In this proposed safety switch, the switch body is mounted on the wall around the doorway of the room, and when the door of the doorway is closed, a dedicated actuator fixed to the door enters the operating section of the switch body, thereby contacting A switch with a structure in which the movable contact (movable piece) of the block switches. 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 can be operated. It becomes a state.

[0006]

By the way, Japanese Patent Application Laid-Open No.
Current products such as the safety switch described in No. 76674 have no particular problem in terms of functionality and safety. However, recently, the use of this type of safety switch has been diversified, and accordingly the installation space has been increased. It is also desired to provide a small and small safety switch.

Accordingly, an object of the present invention is to provide a small-sized safety switch having the same level of functionality and safety as conventional products.

[0008]

In order to achieve the above object, a safety switch according to the present invention, as shown in FIG. 1 to FIG. Switch unit 112 according to
Is a switch having a structure in which the operation rod 6 moves to switch the connection contact.
The insertion part to be inserted into the pressing piece 121 at the tip and the pressing piece 1
21 are formed by supporting pieces 122 and 123 whose front ends protrude forward from the pressing piece 121.

Further, the operation unit 11 of the safety switch of the present invention.
Reference numeral 1 denotes a cam that rotates in response to the entry of the actuator 102 and displaces the operation rod 6. The concave portions 1 a and 1 b and the lock groove 1 on which the pressing piece 121 of the actuator fits on the outer peripheral surface.
c and 1d, and a camshaft 4
A support frame 11 supporting both ends of the plate cam 1 and a member that is rotatable about an axis orthogonal to the insertion direction of the actuator 102 and that is inclined with respect to the insertion direction of the actuator. 2b, 3b and lock plates 2, 3 formed with locking claws 2c, 3c to be fitted into lock grooves 1c, 1d of the plate cam 1, and a spring 5 fitted between the lock plates 2, 3 and the support frame 11. The operation unit 11
In a state where the actuator 102 is not inserted in the lock plate 1, the lock plates 2 and 3 are held in the lock position by the spring 5,
The locking claws 2c, 3c are fitted into the lock grooves 1c, 1d of the plate cam 1 to regulate the rotation of the plate cam 1, and when the actuator 102 enters the operation unit 111, FIGS.
As illustrated in FIG. 8, the support piece 12 of the actuator
2, 123 are the inclined surfaces 2 of the lock plates 2, 3.
a, 3a (or 2b, 3b), and the lock plates 2, 3 open outwardly around the shaft and engage with the locking claws 2c,
The lock of the plate cam 1 by 3c is released, the plate cam 1 is rotated by the pressing piece 121 of the actuator 102, and the pressing piece 121 is fitted into the concave portion 1a (or 1b) of the outer peripheral surface of the cam. It is characterized by being. When the actuator 102 is pulled out, the lock plates 2 and 3 are returned to their original positions (lock positions).
Is provided by the spring 5.

With the above configuration, even if an operation plate other than the dedicated actuator 102 is inserted into the insertion hole, the operation of the operation unit 111 can be prevented.
That is, in the structure of the present invention, the plate cam 1 can be rotated only when the lock plates 2 and 3 are opened outward and the lock is released. Even if it is attempted to rotate the plate cam 1 by inserting it into the portion 111, the locking claws 2c, 3c of the lock plates 2, 3 are caught by the lock grooves 1c, 1d of the plate cam, and the rotation of the plate cam 1 is prevented.

Further, in the structure of the present invention, since the number of the plate cams is one, the size can be reduced as compared with the related art. That is,
The conventional product (such as the safety switch disclosed in Japanese Patent Laid-Open No. 6-76674) has three plate cams, and all of the plate cams are rotated by the pressing pieces of the actuator. However, according to the present invention, the length of the pressing piece of the actuator can be reduced by using a single plate cam. Only small size can be measured.

In the present invention, the intended purpose can be achieved by providing the lock plate on one of the left and right sides of the plate cam. However, it is better to provide the lock plate on the left and right sides of the plate cam. This is preferable in that a double lock is applied to ensure higher safety.

In the present invention, if the lock plate has a structure rotatable about two axes orthogonal to each other, as shown in FIGS.
02 can be inserted in two directions, and the degree of freedom in mounting is expanded. In this case, as shown in FIG. 1B, if the insertion hole 101a of the actuator 102 is provided on the front side of the switch main body 101, the insertion direction of the actuator and the drawing direction of the wiring are made to be on the same straight line. It can help save space.

[0014]

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 embodiment 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 peripheral wall of the entrance of the room, and the actuator 102 is a door 103
To be fixed. The position of the actuator 102 is the position facing the insertion hole 101a of the switch body, and the door 103
When the switch is closed, the operation unit 1 of the switch body 101 is closed.
Enter into 11.

Then, when the actuator 102 enters, the connection contacts of the contact block (see FIG. 9) built in the switch section 112 are switched, and the machine in the room can be driven. On the other hand, when the actuator 102 comes out of the operation unit 111 due to the opening of the door 103, the power supply contact switches and the power supply to the machine is turned off.

The actuator 102 is shown in FIG.
As shown in FIG. 7, the insertion part into the operation part 111 has a pressing piece 121 at the tip and a pair of supporting pieces 122, 1 supporting both ends thereof.
23. The pair of support pieces 12
The distal end portions 2 and 123 project forward from the pressing piece 121, and the pressing surface of the actuator 102 is formed with two pressing surfaces 121 a and 121 b of a concave portion and a convex portion.

In addition to the front insertion hole 101a, the switch body 101 has an insertion hole 1 on the lower surface of the body.
01b is provided, and any one of the insertion holes 101a or 101b can be selected according to the situation of the installation location.

Next, the mechanism of the operation unit of this embodiment is as follows.
Hereinafter, description will be made with reference to FIGS. Note that FIG.
(A) is a longitudinal sectional view at the center of the operation unit 111, and (B) is a front view showing a cutaway cover. 3 and 4 are a sectional view taken along line XX and a view taken in the direction of arrow Y in FIG. 2, respectively.

First, the operation unit 111 is provided with the plate cam 1. This plate cam 1 is provided with a switch unit 11 shown in FIG.
This is for giving displacement to the operation rod 6 of the second contact block, and is rotatably supported by the support frame 11 via the camshaft 4.

On the outer peripheral surface of the plate cam 1, rectangular recesses 1a and 1b are formed corresponding to the insertion holes 101a and 101b of the actuator.
Lock grooves 1c and 1d are formed between a and 1b.

On the other hand, lock plates 2 and 3 are disposed on both left and right sides of the plate cam 1, respectively. The pair of lock plates 2 and 3 have insertion holes 101a and 101b, respectively.
Slant surfaces 2a, 3a and 2b, 3b are formed at positions opposed to the front end, and locking claws 2c, 3c that fit into the lock grooves 1c, 1d of the plate cam 1 are formed at the front end on the front side.

The inclined surfaces 2a, 3 of the lock plates 2, 3
a and 2b, 3b are surfaces inclined by 45 ° with respect to the insertion direction of the actuator.
It is processed into a shape that spreads outward as it approaches 1b. In addition, each inclined surface 2a, 3a and 2b, 3b
Is a pressing surface 121b of a convex portion of the actuator 102.
Is formed at a position corresponding to.

Each of the lock plates 2 and 3 is
1 is rotatably supported on the support frame 11 via spherical fulcrums 2d, 3d integrally formed at the lower end on the rear side (switch 112 side), and further fitted between the support frame 11 and the support frame 11. The postures as shown in FIGS. 2 and 3 are maintained by the compression coil springs 5, 5, and with the support by these members, the lock plates 2, 3 pass through the centers of the fulcrums 2d, 3d, respectively. Rotation is possible about two axes orthogonal to the rotation center of the plate cam 1, that is, two axes parallel to the insertion direction of the actuator.

Next, the operation of the embodiment of the present invention will be described with reference to FIGS. 5 and 6 show a case where the actuator 102 is inserted into the insertion hole 101a located on the front side of the two insertion holes provided in the operation unit 111. FIG. 6 (A) shows a view taken in the direction of the arrow Y in FIG. 2, similarly to FIG. 4, and FIG. 6 (B) shows a view from the insertion direction of the actuator (front view). This shows the inserted state.

When the actuator 102 enters the inside of the operation section 111 through the insertion hole 101a, first, the pressing surface 121b of the protruding portion at the tip thereof is fixed to each of the lock plates 2,3.
(FIG. 6 (A)). At this time, the pressing surface 121a of the concave portion of the actuator is not in contact with the plate cam 1.

When the actuator 102 enters from this state, the slopes 2 of the lock plates 2 and 3 are correspondingly adjusted.
a and 3a are pushed, and the lock plates 2 and 3 are fulcrums 2d and 3d.
Is opened for a moment in a U-shape around the center (the axis perpendicular to the actuator insertion direction), and is held in a parallel posture by the elastic force of the compression coil springs 5, 5. As shown in 6 (B),
Each of the lock plates 2 and 3 opens outward around an axis passing through the centers of the fulcrums 2d and 3d and parallel to the actuator insertion direction, whereby the locking claws 2c and 3c respectively lock the plate cam 1 with the lock grooves. 1c and 1d, the plate cam 1 is unlocked, and the pressing surface 121a of the concave portion of the actuator 102 comes into contact with the plate cam 1 as shown in FIG.

The switch unit 1 according to the rotation of the plate cam 1
When the operating rod 6 moves forward and the actuator 102 advances to the insertion end, the connection contact is switched, and the pressing piece 121 of the actuator 102 fits into the recess 1a of the plate cam 1 as shown in FIG. Put in.

In the above operation, each lock plate 2,
When the opening 3 is opened outward, the compression coil springs 5 are in a state of being compressed between the lock plates 2 and 3 and the support frame 11. When the actuator 102 is removed from the state shown in FIGS. 5B and 6B, the plate cam 1 rotates in the opposite direction due to the retraction of the actuator 102, and the operating rod 6 is accordingly moved. As the connection contacts are switched back, the lock grooves 1c and 1d of the plate cam 1 return to their original positions, that is, the positions shown in FIGS. 5 (A) and 6 (A). It returns to the original position (lock position) by the elastic force of the spring 5, and the locking claws 2c,
The plate cam 1 is inserted into the lock grooves 1c and 1d of the plate cam 1c.
Rotation is regulated.

FIGS. 7 and 8 are explanatory diagrams of the operation when the actuator 102 is inserted into the other insertion hole 101b. 8 (A) corresponds to the front view of FIG. 2 (B), and FIG. 8 (B) is a view from the insertion direction of the actuator (bottom view) in which the actuator is inserted to the insertion end. Indicates the status.

In this case as well, the actuator 1
When 02 enters the inside of the operation unit 111 through the insertion hole 101b, first, the tip of the actuator 102 hits the inclined surfaces 2b and 3b of the lock plates 2 and 3 (FIG. 8A).
Next, the lock plates 2 and 3 are opened outwardly about the fulcrums 2d and 3d (the axes parallel to the actuator insertion direction) (FIG. 8B), and the locking claws 2c and 3c are respectively engaged with the lock grooves of the plate cam 1. 1c and 1d, the lock of the plate cam 1 is released.

In accordance with this, as shown in FIG. 7A, the pressing surface 121a of the concave portion of the actuator 102 comes into contact with the plate cam 1, and the plate cam 1 rotates. When the operating rod 6 of the actuator 112 advances, the connection contact is switched, and the pressing piece 121 of the actuator 102 is moved to the concave portion 1b of the plate cam 1 as shown in FIG.
Fit in.

The operation when the actuator 102 is removed is the same as that described above, and the description is omitted. Here, in the above embodiment, each lock plate 2, 3
Is rotatable about two axes orthogonal to each other, so that the insertion direction of the actuator 102 can be changed by appropriately changing the positions and the number of the recesses and lock grooves formed on the outer peripheral surface of the plate cam 1. For example, as shown in FIG. 10, actuator insertion holes 201 a and 201
1b can also be provided.

[0034]

As described above, according to the safety switch of the present invention, the plate cam that rotates in response to the entry of the actuator into the operation section and moves the operation rod of the switch section is made into one sheet, and The lock mechanism for the plate cam is configured by arranging the lock plate on the side, and the operation unit does not operate except for the dedicated actuator. Miniaturization can be achieved.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of the present invention, wherein (A) is an external perspective view and (B) is a view showing a use state;

FIG. 2 is a configuration diagram of an operation unit 111 according to the embodiment;
(A) is a vertical sectional view at the center, and (B) is a front view with the cover cut away.

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is a view taken in the direction of the arrow Y in FIG. 2;

FIG. 5 is a diagram illustrating the operation of the embodiment of the present invention.

FIG. 6 is an explanatory view of the operation.

FIG. 7 is an explanatory diagram of the same operation.

FIG. 8 is an explanatory diagram of the same operation.

FIG. 9 is a diagram schematically showing a configuration example of a contact block of a switch unit 112;

FIG. 10 is an external perspective view of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate cam 1a, 1b Depression 1c, 1d Lock groove 2, 3 Lock plate 2a, 3a Inclined surface 2b, 3b Inclined surface 2c, 3c Locking claw 2d, 3d Support point 4 Cam shaft 5 Compression coil spring 6 Operation rod 11 Support frame DESCRIPTION OF SYMBOLS 101 Switch main body 111 Operation part 112 Switch part 102 Actuator 121 Pressing piece 122, 123 Supporting piece 121a, 121b Pressing surface 103 Door

Claims (3)

[Claims] 1. A safety switch having a structure in which when an actuator enters an operation section of a switch body, an operation rod of the switch section moves in accordance with the movement and a connection contact is switched. However, the operating portion is constituted by a supporting piece that supports the both ends of the pressing piece and the pressing piece at the distal end and protrudes forward from the pressing piece, and the operating portion rotates in accordance with the entry of the actuator to the operating rod. A plate cam having a concave portion and a lock groove formed on the outer peripheral surface of the cam that gives a displacement and into which the pressing piece of the actuator fits, a support frame for supporting both ends of the cam shaft, and an insertion direction of the actuator located on the side of the plate cam. A member that is rotatable about an axis perpendicular to the axis and has an inclined surface that is inclined with respect to the insertion direction of the actuator and a locking claw that fits into the lock groove of the plate cam. A lock plate has been made, a spring fitted between the locking plate and the support frame, in a state that does not insert the actuator to the operating unit,
The lock plate is held at the lock position by the spring, and the locking claw is fitted into the lock groove of the plate cam to restrict the rotation of the plate cam. When the actuator enters, the projecting end of the support piece is locked by the lock plate. When the lock plate is opened outward about the shaft, the lock of the plate cam by the locking claw is released, and the plate cam is rotated by the pressing piece of the actuator, and the outer peripheral surface of the plate cam is rotated. A safety switch characterized in that a pressing piece is fitted into a recess. 2. The safety switch according to claim 1, wherein the lock plates are provided on both sides of the plate cam. 3. The lock plate is configured to be rotatable about two axes orthogonal to each other, and the operation unit is provided with two actuator insertion holes in which actuator insertion directions are orthogonal to each other. 2. The device according to claim 1, wherein the actuator is inserted into one of the two insertion holes to release the rotation of the plate cam by the locking claw of the lock plate. 3. The safety switch according to 2.