CN114823186A

CN114823186A - Safety switch

Info

Publication number: CN114823186A
Application number: CN202210058479.9A
Authority: CN
Inventors: 釜谷拓次; 山野雅丈; 藤谷繁年; 出头学; 福井孝男
Original assignee: Idec Corp
Current assignee: Idec Corp
Priority date: 2021-01-22
Filing date: 2022-01-19
Publication date: 2022-07-29
Also published as: DE102022100787A1; JP2022113021A

Abstract

The invention provides a safety switch, which not only can simplify the structure and restrain the increase of power consumption, but also can reliably lock an actuator to improve the reliability. A safety switch (1) for switching the output state of the switch by the cooperative action of an actuator (2) and a switch main body (3) is constructed. In this case, the actuator (2) has a locking bolt (21), and the locking bolt (21) has a tip portion (22) that can be inserted into the switch body (3). The switch main body (3) has: a rod (30) capable of reciprocating; and a lock lever (31) which is provided at the tip of the lever (30) so as to be capable of swinging and which is capable of locking the tip (22) of a lock bolt (21) inserted into the switch body (3).

Description

Safety switch

Technical Field

The present invention relates to a safety switch that switches an output state of a switch by an actuator cooperating with a switch main body.

Background

A safety switch that is turned on/off according to the open/close state of a door is provided at an entrance/exit of a dangerous area provided in an industrial machine such as a machine tool or an industrial robot.

Safety switches generally have: an actuator disposed on the door side; and a switch body disposed on the wall side, the switch body having a cam rotated by insertion of the actuator and an operating lever moved in accordance with an operation of the cam. If the actuator on the door side is inserted into the switch body on the wall side when the door is closed, the actuator is locked by the cam and the operating lever, whereby the door is locked, and the operating lever inside the switch body is moved so that the contacts are switched (see fig. 1 and the like of japanese patent laid-open No. 2005-294047).

In such a safety switch, a special-shaped actuator and a cam having a complicated shape corresponding to the special-shaped actuator are used, and thus, the door is not locked improperly. In addition, if a safety switch without using a cam is constructed, it is not necessary to manufacture a cam having a complicated shape, and the structure can be simplified.

Therefore, it is also conceivable to lock the actuator directly by the operating lever, but in this case, it is conceivable that an excessive force is directly applied from the actuator to the operating lever as the door is opened and closed. Therefore, it is also a solution to increase the rigidity of the operation lever by increasing the axial diameter of the operation lever, but in this case, the operation lever becomes large in size and increases in weight, and large power consumption is required to operate the operation lever.

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-294047 (see FIG. 1)

Disclosure of Invention

The present invention has been made in view of the above-described conventional circumstances, and an object of the present invention is to provide a safety switch that can be simplified in structure and can suppress an increase in power consumption. Further, the present invention is to provide an actuator capable of reliably locking the actuator and improving reliability. In addition, the invention is to reliably prevent improper locking for such a safety switch.

The safety switch according to the present invention switches an output state of the switch by a cooperative operation of an actuator and a switch main body, the actuator having a locking bolt having a tip portion insertable into the switch main body, the switch main body having: a rod capable of reciprocating; and a lock lever provided at a tip end of the lever so as to be capable of swinging, and capable of locking a tip end portion of a lock bolt inserted into the switch main body.

In the present invention, if the tip end portion of the locking bolt of the actuator is inserted into the bolt insertion hole of the switch body, the tip end portion of the locking bolt is locked by the swingable locking lever of the switch body.

As described above, according to the present invention, a cam having a complicated shape is not required to lock the actuator, and thus the structure can be simplified. Further, since the actuator is not directly locked by the lever, the lever is not increased in size, and an increase in power consumption can be suppressed. Further, according to the present invention, since the lock lever provided at the tip of the lever locks the actuator, the actuator can be reliably locked, and the reliability as a safety switch can be improved.

In the present invention, the locking bolt has a shaft portion and a distal end portion arranged at a distal end of the shaft portion and having a larger diameter than the shaft portion, and the locking lever is provided so as to be lockable to a step between the distal end portion and the shaft portion.

In the present invention, the front end face of the front end portion of the locking bolt has a convex arc face or a tapered face.

In the present invention, a lock lever includes: a shaft supporting part axially supported on the switch main body; and a locking convex part which can make the front end part of the locking bolt locked in a manner of engaging and disengaging, wherein the front end part of the locking bolt is engaged with the front end of the rod in a manner of swinging at the middle position between the shaft supporting part and the locking convex part.

In the present invention, the locking lever swings as the lever moves, and thereby can be set to a locking position for locking the tip end portion of the locking bolt and an unlocking position for releasing the locked state of the tip end portion.

In the present invention, when the tip of the locking bolt is not inserted into the switch main body, the locking lever swings to an override position that overrides the locking position.

The present invention further includes an approach detection means for detecting an approach state between the actuator and the switch main body.

In the present invention, the proximity detection means has ID information. This can reliably prevent improper locking of the actuator.

The present invention further includes a position detection mechanism for detecting the swing position of the lock lever.

The present invention further comprises: an approach detection means for detecting an approach state between the actuator and the switch main body; and a position detection mechanism for detecting the swing position of the locking lever, and outputting a safety signal or an error signal based on the detection results of the proximity detection mechanism and the position detection mechanism.

In the present invention, when the approach detection means detects the approach of the actuator to the switch main body and the position detection means detects the swing position at the time of locking the lock lever, a safety signal is output.

Effects of the invention

As described above, according to the safety switch of the present invention, the structure can be simplified and an increase in power consumption can be suppressed. Further, according to the present invention, the actuator can be reliably locked, and reliability can be improved.

Drawings

Fig. 1 is a schematic diagram of a safety switch according to embodiment 1 of the present invention, which is a longitudinal sectional configuration for explaining a change in timing of the safety switch from a state in which a lever inside a switch main body is retracted downward to a state in which an actuator is inserted into the switch main body, and shows a state before the actuator is inserted into the switch main body.

Fig. 1A is a diagrammatic sectional view along line IA-IA of fig. 1, showing a cross-section of the safety switch (fig. 1).

Fig. 2 shows the state of the safety switch (fig. 1) immediately after the actuator is inserted into the switch body.

Fig. 2A is a diagrammatic sectional IIA-IIA line view of fig. 2, showing a cross-section of the safety switch (fig. 2).

Fig. 3 shows a state in which the actuator of the safety switch (fig. 1) is locked after being inserted into the switch body.

Fig. 3A is a diagrammatic cross-sectional view taken along line IIIA-IIIA of fig. 3, showing a cross-section of the safety switch (fig. 3).

Fig. 4 is a schematic block diagram of the control unit of the safety switch (fig. 1).

Fig. 5 is a flowchart showing a control flow of the safety switch (fig. 1) corresponding to fig. 1 to 3.

Fig. 5A is a list showing details of a normal operation and an abnormal operation of the safety switch (fig. 1).

Fig. 6 is a schematic diagram of a safety switch according to embodiment 2 of the present invention, which is a longitudinal sectional configuration for explaining a change in timing of the safety switch from a state in which a lever inside a switch main body is retracted downward to a state in which an actuator is inserted into the switch main body, and shows a state before the actuator is inserted into the switch main body.

Fig. 7 shows a state in which the actuator of the safety switch (fig. 6) is inserted into the switch body to lock the actuator.

Fig. 8 is a schematic diagram of a safety switch according to embodiment 3 of the present invention, which is a longitudinal sectional configuration for explaining a change in timing of the safety switch from a state in which a lever inside a switch main body is excessively raised to a state in which an actuator is input to the switch main body, and shows a state before the actuator is inserted into the switch main body.

Fig. 9 shows a state immediately after the tip of the locking bolt of the actuator of the safety switch (fig. 8) is inserted into the switch body.

Fig. 10 shows a state in which the tip end of the locking bolt of the actuator of the safety switch (fig. 8) is inserted into the switch body and locked.

Fig. 11 is a flowchart showing a control flow of the safety switch (fig. 8) corresponding to fig. 8 to 10.

Fig. 11A is a list showing details of a normal operation and an abnormal operation of the safety switch (fig. 8).

Description of the reference numerals

1: safety switch, 2: actuator, 21: locking bolt, 21A: shaft portion, 22: front end portion, 22a convex arc-shaped surface (front end surface), 22 b: flat surface, 3: switch main body, 30: rod, 30 a: front end, 31: locking lever, 31A: shaft support portion, 31B: locking projection, 6, 7: proximity detection mechanism, 6: RF tag, 7: RFID readers, 102a to 102 d: photoelectric sensor (position detection mechanism) 103: safety signal output unit, 104: error signal output unit

Detailed Description

Hereinafter, embodiments of the present invention will be described based on the drawings.

< example 1 >

Fig. 1 to 5A are diagrams for explaining a safety switch according to embodiment 1 of the present invention, fig. 1, 2, and 3 are schematic diagrams of a longitudinal sectional structure of the safety switch showing operations of respective members when an actuator is inserted into a switch body in time series, fig. 1A, 2A, and 3A are schematic diagrams of a transverse sectional structure of the safety switch corresponding to fig. 1, 2, and 3, respectively, fig. 4 is a schematic block diagram of a control unit of the safety switch, fig. 5 is a flowchart of the control unit, and fig. 5A is a list diagram showing details of a normal operation and an abnormal operation of the safety switch. In the following description, the vertical direction in fig. 1, 2, and 3 is referred to as the vertical direction.

As shown in fig. 1 and 1A, the safety switch 1 according to the present embodiment includes: an actuator 2 disposed in, for example, a sliding type movable door (not shown); and a switch main body 3 disposed on, for example, a wall or a fixed door (not shown), wherein the actuator 2 moves in the horizontal direction of the drawing to be inserted into and removed from the switch main body 3 in accordance with the opening and closing of the movable door, and thereby the actuator 2 and the switch main body 3 cooperate with each other to switch the output state of a switch (not shown) inside the switch main body 3. Fig. 1 shows a state in which the movable door is closed halfway, the movable door is slightly opened, and the actuator 2 moving together with the movable door is in a state before being inserted into the switch main body 3.

The actuator 2 includes a base 20 attached to the movable door and a locking bolt 21 protruding from the base 20. The locking bolt 21 includes: a shaft portion 21A extending in the axial direction, for example, in a cylindrical shape; and a distal end portion 22 disposed at the distal end of the shaft portion 21A and insertable into the switch body 3. The tip portion 22 is a hemispherical projection, for example, and is a member having a diameter larger than the shaft portion 21A, and includes: a convex arc-shaped surface (or tapered surface) 22a as a front end surface disposed on the front end side; and a flat surface 22b disposed on the rear end side and extending in a direction orthogonal to the axial direction. The tip of the shaft portion 21A is integrally and continuously provided on the flat surface 22 b. The flat surface 22b is formed with a step with respect to the front end of the shaft portion 21A. A substantially cylindrical flange portion 23 protruding outward in the radial direction is provided at a substantially central portion of the shaft portion 21A. The flange portion 23 has a cylindrical outer peripheral surface 23 a. The outer peripheral surface 23a preferably has an outer diameter substantially the same as the inner diameter of the actuator insertion hole 3a (or the outer diameter of the distal end portion 22) described later. Further, an RF tag 6 is attached (or embedded) on a surface 20A of the base portion 20 of the actuator 2 facing the switch main body 3.

As shown in fig. 1 and 1A, the switch main body 3 has an actuator insertion hole 3a into which the tip portion 22 of the actuator 2 is inserted. The actuator insertion hole 3a is a hole, for example, circular in cross section, which opens at one end of the switch body 3, extends in the axial direction of the locking bolt 21 of the actuator 2, and has a tapered surface 3b at its open end, the diameter of which becomes smaller as it goes toward the inside of the switch body 3. The tapered surface 3b functions as a guide surface when the distal end portion 22 of the actuator 2 is inserted into the actuator insertion hole 3 a.

The switch main body 3 has: a rod 30 provided so as to be capable of reciprocating in the up-down direction; and a lock lever 31 provided at the tip 30a of the lever 30 so as to be swingable in the vertical direction. The lock lever 31 is a substantially belt-shaped member in plan view (see fig. 1A), and has a shaft support portion 31A (fig. 1A) pivotally supported on the switch body 3 so as to be rotatable in the vertical direction on a base end side (right side in the figure), and has a locking projection 31B as a locking portion capable of locking the distal end portion 22 of the locking bolt 21 on a distal end side (left side in the figure). The locking convex portion 31B is provided as a step that can be locked to the flat surface 22B of the distal end portion 22 of the locking bolt 21 so as to be able to engage and disengage. A rectangular through hole 31c that vertically penetrates the lock lever 31 is formed at an intermediate position between the shaft support portion 31A and the locking projection 31B of the lock lever 31, and a two-leg engaging portion 31d that extends from the shaft support portion 31A side is provided in the through hole 31 c. An engaging recess (in this example, a circumferential groove) 30b is formed at a position below the tip 30a of the lever 30, and the engaging portion 31d of the lock lever 31 engages with the engaging recess 30b of the lever 30, whereby the lock lever 31 swings in the vertical direction about the axial center O (fig. 1) of the shaft support portion 31A as the lever 30 reciprocates in the vertical direction.

The lock lever 31 can be set to a lock position (described later in fig. 3) in which it swings upward to lock the distal end portion 22 of the lock bolt 21, and an unlock position (fig. 1) in which it swings downward to release the locked state of the distal end portion 22 of the lock bolt 21.

Although not shown, a position detection mechanism for detecting the swing position of the lock lever 31 is provided. The position detection mechanism is constituted by, for example, a photoelectric sensor (transmission type or reflection type) in which a light projection unit having a light source and projecting light and a light receiving unit having a light receiving element for receiving the projecting light from the light projection unit are arranged to face each other. The light projecting part and the light receiving part of the photoelectric sensor are arranged at the following positions: for example, when the lock lever 31 is moved to the lock position, the locking projection 31B (or a portion near the shaft support portion 31A) of the lock lever 31 that swings upward and moves to the lock position blocks light from the light projecting portion of the photoelectric sensor. That is, the light projecting section and the light receiving section are disposed on both sides of the locking projection 31B (or the portion near the shaft supporting section 31A) with the locking projection 31B (or the portion near the shaft supporting section 31A) of the locking lever 31 at the locking position interposed therebetween. At this time, if the light from the light-projecting section is blocked, the lock lever 31 is in the lock position, and if the light receiving section receives the light from the light-projecting section, the lock lever 31 is in a position other than the lock position (for example, the unlock position).

Further, since the lock lever 31 is coupled to the tip 30a of the lever 30 so as to be able to swing, a swing position, that is, a swing angle of the lock lever 31 has a correlation with a movement amount of the lever 30. Therefore, the position detection means such as a photoelectric sensor may be disposed at a position (for example, a position of a detected portion (not shown) provided in the lever 30) at which the movement of the lever 30 in the vertical direction can be detected, and at this time, the swing position of the lock lever 31 is indirectly detected by detecting the position of the lever 30.

An electromagnetic solenoid 4 is provided at a lower portion of the rod 30. The electromagnetic solenoid 4 has a solenoid body 40 constituted by a coil disposed around the rod 30, and is configured such that: when a current is supplied to the solenoid body 40, the rod 30 is pulled downward by the electromagnetic force generated in the solenoid body 40. Note that, in fig. 1 (fig. 2 and the later-described embodiment 2), the solenoid body 40 is indicated by a thick line to clearly show that current is being supplied to the solenoid body 40. A compression spring 5 is disposed at the lower end of the lever 30, and the compression spring 5 constantly biases the lever 30 upward.

In addition, an rfid (radio frequency identifier) reader 7 is attached (or embedded) to a surface 3A of the switch main body 3 facing the actuator 2. The RFID reader 7 is disposed at a position facing the RF tag 6 of the actuator 2, and reads ID information stored in the RF tag 6. The RFID constituted by the RF tag 6 and the RFID reader 7 constitutes an approach detection mechanism for detecting an approach state between the actuator 2 and the switch main body 3.

The safety switch 1 has a control unit 100 shown in fig. 4. The control unit 100 includes a microcomputer 101. The microcomputer 101 includes a CPU and a memory (ROM, RAM, etc.). The RFID reader 7 and the photosensor 102 are connected to an input side of the microcomputer 101. The output side of the microcomputer 101 is connected to an electromagnetic solenoid 4, a safety signal output unit 103, an error signal output unit 104, and an error display unit 105.

Next, an example of a control flow of the control unit 100 will be described with reference to fig. 5 with reference to fig. 1 to 4.

In addition, fig. 5 shows a flow of the movable door transitioning from the open state to the closed state (open → closed), and omits a case where the movable door transitions from the closed state to the open state (closed → open).

If the routine is started, the solenoid is turned on in step S1 of fig. 5. That is, the current is supplied to the solenoid body 40 of the electromagnetic solenoid 4. Then, the rod 30 is pulled and moved downward against the elastic reaction force of the compression spring 5 by the electromagnetic force generated in the solenoid body 40 (see fig. 1). At this time, the lock lever 31 provided at the distal end 30a of the lever 30 so as to be swingable in the vertical direction swings downward about the axial center O of the shaft support portion 31A, and the locking protrusion 31B at the distal end moves to the unlock position (fig. 1) which is a position to sink downward from the inner peripheral surface of the actuator insertion hole 3 a. The unlock position is detected by the photoelectric sensor 102 (fig. 4).

Next, in step S2, detection of the RF tag 6 is waited for. When the movable door is moved from the state shown in fig. 1 to the closing direction (right side in the figure), the actuator 2 approaches the switch body 3, and as shown in fig. 2 and 2A, the locking bolt 21 of the actuator 2 is inserted into the actuator insertion hole 3a of the switch body 3. At this time, the tip portion 22 of the locking bolt 21 is positioned above the locking lever 31 inside the switch body 3.

When the locking bolt 21 is inserted into the actuator insertion hole 3a, not only the distal end portion 22 of the locking bolt 21 but also the flange portion 23a are inserted into the actuator insertion hole 3a, and the outer peripheral surface of the flange portion 23a comes into contact with the inner peripheral surface of the actuator insertion hole 3 a. Thereby, the locking bolt 21 is centered (positioned) with respect to the actuator insertion hole 3a such that the center axis of the locking bolt 21 coincides with the center axis of the actuator insertion hole 3 a. When the locking bolt 21 is inserted into the actuator insertion hole 3a, the RF tag 6 of the actuator 2 approaches the RFID reader 7 of the switch body 3 and the two are disposed close to each other (see fig. 2). When the RFID reader 7 detects the RF tag 6, the process proceeds to step S3.

In step S3, the RFID reader 7 reads the ID information stored in the RF tag 6, and if the read ID information matches the normal/proper information, "Yes" is determined in step S3, and the process proceeds to step S4.

In step S4, the solenoid is turned off. That is, the supply of the current to the solenoid body 40 of the electromagnetic solenoid 4 is stopped. Then, the electromagnetic force generated in the solenoid body 40 disappears, and therefore the rod 30 moves upward by the elastic reaction force of the compression spring 5 acting on the lower end of the rod 30. At this time, the lock lever 31 provided at the distal end 30a of the lever 30 so as to be swingable in the vertical direction swings upward around the axial center O of the shaft support portion 31A, and the locking protrusion 31B at the distal end protrudes upward from the inner peripheral surface of the actuator insertion hole 3 a. Then, as shown in fig. 3, the locking surface 31B of the locking projection 31B of the locking lever 31 is locked from below to the flat surface 22B of the distal end portion 22 of the locking bolt 21, whereby the locking bolt 21 is locked by the distal end portion 22. At this time, the lock lever 31 is disposed at the lock position (fig. 3). The locked position is detected by the photosensor 102 (fig. 4).

Next, in step S5, it is determined whether the lock lever 31 is in the lock position. As described above, if the photosensor 102 detects that the lock lever 31 has moved to the lock position, "Yes" is determined in step S5 and the process proceeds to step S6.

In step S6, the safety signal output unit 103 (fig. 4) outputs a safety signal (operation permission signal). The output safety signal is input to a controller (not shown) of a machine such as a robot provided inside the door, and the machine can be driven based on the safety signal.

In addition, if it is determined in step S3 that the read ID information does not match the normal/proper information, "No" is determined in step S3, and the process proceeds to step S7. In step S7, an error signal is output from the error signal output unit 104 (fig. 4). Next, in step S8, an error display (for example, display of ID mismatch) is performed in the error display unit 105 (fig. 4) based on the error signal output in step S7.

In addition, in step S5, if it is determined that the lock lever 31 is not in the lock position, "No" is determined in step S5 and the process proceeds to step S9. In addition, when the lock lever 31 is not disposed at the lock position, it is considered that the following may occur: the locking bolt 21 is not inserted into the actuator insertion hole 3a, and only the RF tag is brought close to the RFID reader 7. At this time, the lock lever 31 is raised, but the lock bolt 21 is not inserted, and therefore, the lock lever 31 is further raised (i.e., excessively raised) beyond the lock position until it moves to the over position. At this time, the photoelectric sensor 102 does not detect the lock position of the lock lever 31. In step S9, an error signal is output from the error signal output unit 104 (fig. 4). Next, in step S10, an error display (for example, display of no locking bolt) is performed on the error display unit 105 (fig. 4) based on the error signal output in step S9.

Next, in step S11, the solenoid is turned on. That is, when current is supplied to the solenoid body 40 of the electromagnetic solenoid 4 and the rod 30 moves downward, the lock lever 31 swings downward and moves to the unlock position (fig. 1). After the process of step S11, the process returns to step S2, and the processes of steps S2 to S5 are repeatedly executed. In a case where only the RF tag is brought close to the RFID reader 7 without inserting the locking bolt 21 into the actuator insertion hole 3a, the process of step S2 → S3 → S4 → S5 → S9 → S10 → S11 is repeatedly performed. At this time, if the RF tag is moved away from the RFID reader 7, the position at step S2 becomes a standby state.

As described above, according to the present embodiment, a cam having a complicated shape is not required to lock the actuator 2, and therefore, the structure can be simplified. Further, since the actuator 2 is not directly locked by the lever 30, the lever 30 is not increased in size, and an increase in power consumption can be suppressed. Further, according to the present embodiment, since the lock lever 31 provided at the distal end 30a of the lever 30 locks the actuator 2, the actuator 2 can be reliably locked, and the reliability as the safety switch 1 can be improved. Further, according to the present embodiment, since the RF tag 6 stores the ID information, improper locking of the actuator 2 can be reliably prevented.

In the present embodiment, as shown in the flow from step S2 to step S11, a safety signal or an error signal is output based on the detection results of the proximity detection means for RFID including the RF tag 6 and the RFID reader 7 and the position detection means including the photoelectric sensor 102. As shown in the flow from step S2 to step S6, the proximity detection means is configured to: since the safety signal is output when the approaching state of the actuator 2 and the switch body 3 is detected and the position detection means detects the swing position, that is, the lock position when the lock lever 31 is locked, the reliability as the safety switch 1 can be further improved.

Fig. 5A shows details of the normal operation and the abnormal operation of the safety switch 1.

Nos. 1-a, 1-B in fig. 5A show the normal operation of the safety switch 1. In the OPEN door (OPEN) state shown in No.1-a, the locking bolt 21 is not inserted into the switch main body 3, detection by RFID is not performed, the solenoid main body 40 is excited, the locking lever 31 is at the unlock position, and the operation of the machine inside the door is stopped (see step S1 in fig. 1 and 5). At this time, the door is in an unlocked state, and neither an error signal nor a safety signal is output. In the door CLOSED (CLOSED) state shown in No.1-B, the locking bolt 21 is inserted into the switch main body 3, detection by RFID is performed, the solenoid main body 40 is not excited, the locking lever 31 is in the locking position, the door is locked, and a safety signal is output without outputting an error signal (see step S2 → S3 → S4 → S5 → S6 in fig. 3 and 5). Thereby, the machinery inside the door operates.

Nos. 2-a to 3-B in fig. 5A show abnormal actions of the safety switch 1. In the OPEN (OPEN) state shown in No.2-a, the locking bolt 21 is not inserted into the switch body 3, and detection by RFID is performed only by approaching the RF tag (see page 8, line 26 to page 9, line 3), the solenoid body 40 is not excited, the lock lever 31 is at the passing position after the excessive rise, the door is not locked, and an error signal is output without outputting a safety signal (see step S5 → S9 in fig. 5). This stops the operation of the machine inside the door. In the CLOSED door (CLOSED) state shown in No.2-B, the locking bolt 21 is inserted into the switch main body 3, and the RF tag does not approach, so that the detection by the RFID is not performed, the solenoid main body 40 is excited, the locking lever 31 is in the unlocked position, the door is not locked, and neither an error signal nor a safety signal is output. At this time, the routine is in a standby state in step S2 of fig. 5, and the machine inside the door is stopped.

In the CLOSED door (CLOSED) state shown in No.2-C, the locking bolt 21 is inserted into the switch main body 3, and the RF tag approaches, and therefore, detection by the RFID is performed, but the ID does not match and the solenoid main body 40 remains excited because of the difference in the RF tag. The locking lever 31 is in the unlocked position and the door is unlocked and neither an error signal nor a security signal is output. At this time, the routine is in a standby state in step S2 of fig. 5, and the machine inside the door is stopped.

In the OPEN (OPEN) state shown in No.3-a, the power supply of the control circuit is turned off, and therefore, the solenoid main body 40 is not excited, and the locking bolt 21 is not inserted into the switch main body 3, and therefore, the locking lever 31 is at the override position after being excessively raised, and detection by RFID is not performed. At this time, the door is in an unlocked state and in a state where neither an error signal nor a safety signal can be output. The CLOSED door (CLOSED) state shown in No.3-B corresponds to a state after the door is CLOSED from the OPEN door (OPEN) state shown in No.3-a, and when the locking bolt 21 is inserted into the switch body 3, the tip portion 22 of the locking bolt 21 gradually presses the locking lever 31 beyond the position downward, so that the locking lever 31 is shifted to the locking position, and the locking bolt 21 is locked to lock the door. At this time, since the safety signal cannot be output, the operation of the machine inside the door is stopped.

After the operation of the machine inside the door is stopped, the current is supplied to the electromagnetic solenoid 4 upon receiving the unlock signal from the machine side, and the rod 30 is moved downward, thereby releasing the locked state of the locking bolt 21 by the locking lever 31. This allows the door to be opened by turning the door to the unlocked state.

< example 2 >

Fig. 6 and 7 are schematic diagrams illustrating a longitudinal sectional structure of the safety switch according to embodiment 2 of the present invention, and show the operation of each member in time series when the actuator is inserted into the switch main body. The vertical direction and the horizontal direction in each drawing are referred to as vertical direction and horizontal direction, respectively. In these figures, the same reference numerals as those of the embodiment 1 denote the same or equivalent parts, fig. 6 corresponds to fig. 1 of the embodiment 1, and fig. 7 corresponds to fig. 3 of the embodiment 1.

In the 1 st embodiment, a position detection mechanism for detecting the swing position of the lock lever 31 is not shown, but in the 2 nd embodiment, a position detection mechanism is shown. As shown in fig. 6, the lower end of the rod 30 is bifurcated into two strands, each extending downward, and having a 1 st lower end 30C and a 2 nd lower end 30D. The 2 nd lower end 30D extends below the 1 st lower end 30C, and has a through hole 30D formed in the left-right direction at the lower end thereof. For example, photoelectric sensors (transmissive type (or reflective type)) having a light projecting portion 102a that has a light source and projects light and a light receiving portion 102b that has a light receiving element that receives the projected light from the light projecting portion 102a are disposed to face each other as position detecting means on both left and right sides with the 1 st lower end portion 30C interposed therebetween. Similarly, for example, photoelectric sensors (transmissive type (or reflective type)) having a light projecting portion 102c that has a light source and projects light and a light receiving portion 102D that has a light receiving element that receives light projected from the light projecting portion 102c are provided as position detecting means on both the left and right sides with the second lower end portion 30D interposed therebetween.

Therefore, in embodiment 2, the position detection mechanism directly detects the vertical position of the lever 30 and indirectly detects the swing position, i.e., the swing angle, of the lock lever 31 in conjunction with the vertical movement of the lever 30.

The safety switch 1 according to embodiment 2 also includes a control unit 100 (fig. 4) similar to that of the first embodiment, and the control unit 100 performs processing according to the same flowchart as that of the first embodiment.

That is, if the routine is started, the solenoid is turned on in step S1 of fig. 5. That is, a current is supplied to the solenoid body 40 of the electromagnetic solenoid 4 (see fig. 6). Then, the rod 30 is pulled and moved downward against the elastic reaction force of the compression spring 5 by the electromagnetic force generated in the solenoid body 40 (see fig. 6). At this time, the lock lever 31 provided at the distal end 30a of the lever 30 so as to be swingable in the vertical direction swings downward about the axial center O of the shaft support portion 31A, and the locking protrusion 31B at the distal end moves to the unlock position (fig. 6) which is a position to sink downward from the inner peripheral surface of the actuator insertion hole 3 a.

When the lock lever 31 is at the unlock position, as shown in fig. 6, the 1 st lower end portion 30C of the lever 30 blocks the light projected from the light projecting portion 102a of the photosensor to the light receiving portion 102b, and the photosensor is turned off, and similarly, the 2 nd lower end portion 30D of the lever 30 blocks the light projected from the light projecting portion 102C of the photosensor to the light receiving portion 102D, and the photosensor is also turned off. Thereby, the unlock position of the lock lever 31 is detected based on the off signal from each photosensor.

Next, in step S2, detection of the RF tag 6 is waited for. When the movable door is moved in the closing direction (right side in the figure) from the state shown in fig. 6, the actuator 2 approaches the switch body 3, and the locking bolt 21 of the actuator 2 is inserted into the actuator insertion hole 3a of the switch body 3. At this time, although not shown, the distal end portion 22 of the locking bolt 21 is positioned above the locking lever 31 inside the switch main body 3, and the RF tag 6 of the actuator 2 is disposed close to the RFID reader 7 of the switch main body 3. If the RFID reader 7 detects the RF tag 6, the process proceeds to step S3.

In step S3, the RFID reader 7 reads the ID information stored in the RF tag 6, and if the read ID information matches the normal/proper information, "Yes" is determined in step S3 and the process proceeds to step S4.

In step S4, the solenoid is turned off. That is, the supply of the current to the solenoid body 40 of the electromagnetic solenoid 4 is stopped. Then, the electromagnetic force generated in the solenoid body 40 disappears, and therefore, the rod 30 moves upward by the elastic reaction force of the compression spring 5 acting on the lower end of the rod 30. At this time, the lock lever 31 provided at the tip 30a of the lever 30 so as to be swingable in the vertical direction swings upward around the axial center O of the shaft support portion 31A, and the locking protrusion 31B at the tip protrudes upward from the inner peripheral surface of the actuator insertion hole 3 a. Then, as shown in fig. 7, the locking surface 31B of the locking projection 31B of the locking lever 31 is locked from below to the flat surface 22B of the distal end portion 22 of the locking bolt 21, whereby the locking bolt 21 is locked by the distal end portion 22. At this time, the lock lever 31 is disposed at the lock position (fig. 7).

When the lock lever 31 is in the lock position, as shown in fig. 7, the 1 st lower end portion 30C of the lever 30 does not block the light projected from the light projecting portion 102a to the light receiving portion 102b of the photosensor, and the photosensor is turned on. On the other hand, the 2 nd lower end portion 30D of the lever 30 is disposed at a position where the through hole 30D faces the light projecting portion 102c and the light receiving portion 102D of the photosensor, and the photosensor is also turned on when the light projected from the light projecting portion 102c passes through the through hole 30D and is received by the light receiving portion 102D. In this way, the lock position of the lock lever 31 is detected based on the on signal from each photosensor.

Next, in step S5, it is determined whether the lock lever 31 is in the lock position. As described above, if the photoelectric sensor 102 detects that the lock lever 31 has shifted to the lock position. It is judged as "Yes" in step S5 and it proceeds to step S6.

On the other hand, in step S3, if the read ID information does not match the normal/proper information, "No" is determined in step S3 and the process proceeds to step S7. In step S7, an error signal is output from the error signal output unit 104 (fig. 4). Next, in step S8, an error display (for example, display ID mismatch or the like) is performed in the error display unit 105 (fig. 4) based on the error signal output in step S7.

In addition, in step S5, if it is determined that the lock lever 31 is not in the lock position, "No" is determined in step S5 and the process proceeds to step S9. Further, as a case where the lock lever 31 is not disposed at the lock position, it is considered that there are cases such as: the locking bolt 21 is not inserted into the actuator insertion hole 3a, and only the RF tag approaches the RFID reader 7 (No. 2-a in fig. 5A). At this time, the lock lever 31 rises, but the lock bolt 21 is not inserted, and therefore, the lock lever 31 further rises (i.e., excessively rises) beyond the lock position until it moves to the over position. At this time, the photoelectric sensor 102 does not detect the lock position of the lock lever 31. The crossing position of the lock lever 31 can be detected by the photoelectric sensor 102 (see fig. 8 and page 14, lines 26 to 32 described later). In step S9, an error signal is output from the error signal output unit 104 (fig. 4). In step S10, an error display (for example, display of no locking bolt) is performed in the error display unit 105 (fig. 4) based on the error signal output in step S9.

Next, in step S11, the solenoid is turned on. That is, by supplying current to the solenoid body 40 of the electromagnetic solenoid 4 and moving the rod 30 downward, the lock lever 31 is swung downward and moved to the unlock position (fig. 6). After the process of step S11, the process returns to step S2, and the processes of steps S2 to S5 are repeatedly executed. In a case where only the RF tag is brought close to the RFID reader 7 without inserting the locking bolt 21 into the actuator insertion hole 3a, the process of step S2 → S3 → S4 → S5 → S9 → S10 → S11 is repeatedly performed. At this time, if the RF tag is moved away from the RFID reader 7, the position at step S2 becomes a standby state.

As described above, according to the present embodiment, a cam having a complicated shape is not required for locking the actuator 2, and therefore, the structure can be simplified. Further, since the actuator 2 is not directly locked by the lever 30, the lever 30 is not increased in size, and an increase in power consumption can be suppressed. Further, according to the present embodiment, since the lock lever 31 provided at the distal end 30a of the lever 30 locks the actuator 2, the actuator 2 can be reliably locked, and the reliability as the safety switch 1 can be improved. Further, according to the present embodiment, the RF tag 6 stores the ID information, so improper locking of the actuator 2 can be reliably prevented.

In the present embodiment, as shown in the flow from step S2 to step S11, a safety signal or an error signal is output based on the detection results of the proximity detection means for RFID including the RF tag 6 and the RFID reader 7 and the position detection means including the photosensor 102. As shown in the flow from step S2 to step S6, the present invention is configured such that: when the proximity detection means detects the proximity of the actuator 2 and the switch body 3 and the position detection means detects the swing position at the time of locking the lock lever 31, that is, the lock position, the safety signal is output, so that the reliability as the safety switch l can be further improved.

< example 3 >

Fig. 8 to 11A are views for explaining a safety switch according to embodiment 3 of the present invention. Fig. 8 to 10 are schematic longitudinal sectional views of the safety switch, showing the operation of each component in time series when the actuator is inserted into the switch main body, fig. 11 is a flowchart of the control unit, and fig. 11A is a list showing details of a normal operation and an abnormal operation of the safety switch. The vertical direction and the horizontal direction in fig. 8 to 10 are referred to as vertical direction and horizontal direction, respectively. In these drawings, the same reference numerals as those in the above-described 1 st and 2 nd embodiments denote the same or equivalent parts.

The safety switch l of embodiment 3 has the same structure (mechanical structure) as the safety switch 1 of embodiment 2, but the control method is different from that of embodiment 2 in embodiment 3. Fig. 11 shows the state until the movable door transitions from the open state to the closed state (open → closed), and the state where the movable door transitions from the closed state to the open state (closed → open) is omitted.

If the routine is started, it is determined in step Tl of fig. 11 whether the lock lever 31 is at the override position beyond the lock position. When the program is started, the solenoid is in the off state, and therefore, no current is supplied to the solenoid body 40 of the electromagnetic solenoid 4, or the supply of current to the solenoid body 40 is stopped (see fig. 8). At this time, since no electromagnetic force is generated in the solenoid body 40, the lever 30 moves upward by the elastic reaction force of the compression spring 5, and the lock lever 31 swings upward about the axial center O of the shaft support portion 31A. At this time, the locking bolt 21 is not inserted into the actuator insertion hole 3a, and therefore the locking lever 31 moves further upward (i.e., excessively rises) beyond the locking position and moves to the override position (see fig. 8). At this time, the locking projection 31B at the distal end of the lock lever 31 projects upward from the inner peripheral surface of the actuator insertion hole 3a (see fig. 8).

When the lock lever 31 is at the over position, as shown in fig. 8, the 1 st lower end portion 30C of the lever 30 does not block the light projected from the light projecting portion 102a to the light receiving portion 102b of the photosensor, and the photosensor is turned on. On the other hand, the 2 nd lower end 30D of the lever 30 is disposed at a position where the lowermost end faces the light projecting portion 102c and the light receiving portion 102D of the photosensor, and the photosensor is turned off when the light projected from the light projecting portion 102c is blocked by the lowermost end. In this way, the crossing position of the lock lever 31 is detected based on the on signal and the off signal from each photosensor. Accordingly, the process proceeds to step T2 after determining "Yes" in step Tl.

When the locking bolt 21 of the actuator 2 is inserted into the actuator insertion hole 3a from the state shown in fig. 8 where the locking lever 31 is located at the over position, the convex arc-shaped surface 22a of the distal end portion 22 of the locking bolt 21 abuts against the locking convex portion 31B of the locking lever 31 as shown in fig. 9. When the locking bolt 21 is further inserted into the actuator insertion hole 3a from this state, the convex arc-shaped surface 22a of the distal end portion 22 of the locking bolt 21 swings the lock lever 31 downward, and the lever 30 moves downward via the lock lever 31. At this time, the lever 30 moves downward against the elastic reaction force of the compression spring 5, and the lever 30 is always urged upward by the elastic reaction force of the compression spring 5 while the lever 30 moves downward. Then, at the moment when the flat surface 22B of the distal end portion 22 of the locking bolt 21 passes over the locking surface 31B of the locking projection 31B of the locking lever 31, the locking lever 31 swings upward, and the locking surface 31B of the locking projection 31B of the locking lever 31 is locked to the flat surface 22B of the distal end portion 22 of the locking bolt 21 from below (see fig. 9). Thereby, the locking bolt 21 is locked, and at this time, the locking lever 31 is disposed at the locking position (fig. 10).

When the lock lever 31 is in the lock position, as shown in fig. 10, the 1 st lower end portion 30C of the lever 30 does not block the light projected from the light projecting portion 102a to the light receiving portion 102b of the photosensor, and the photosensor is turned on. On the other hand, the 2 nd lower end portion 30D of the lever 30 is disposed at a position where the through hole 30D faces the light projecting portion 102c and the light receiving portion 102D of the photosensor, and light projected from the light projecting portion 102c passes through the through hole 30D and is received by the light receiving portion 102D. Thereby, the photosensor is also turned on. In this way, the lock position of the lock lever 31 is detected based on the on signal from each photosensor.

On the other hand, in step T2, it is waited for the lock lever 31 to move to the lock position, and if the lock lever 31 moves to the lock position, "Yes" is determined in step T2 and the process proceeds to step T3. In step T3, the RFID is enabled. That is, the RF tag 6 is in a detectable state. Next, at step T4, it is determined whether or not the RF tag 6 is detected.

When the insertion of the locking bolt 21 into the actuator insertion hole 3a is completed, the RFID reader 7 on the switch main body 3 side detects the RF tag 6 on the actuator 2 side. Accordingly, the determination in step T4 is "Yes" and the process proceeds to step T5.

In step T5, the ID information stored in the RF tag 6 is read by the RFID reader 7. And judges whether the read ID information coincides with the normal/proper information. If the ID information is identical, the process proceeds to step T6.

In step T6, the safety signal output unit 103 (fig. 4) outputs a safety signal (operation permission signal). The output safety signal is input to a controller (not shown) of a machine such as a robot provided inside the door, and the machine can be driven based on the safety signal.

On the other hand, in step T4, if it is determined that RF tag 6 is not detected, it is determined as "No" in step T4 and the process proceeds to step T7. Although the RFID is detected in step T4 and the process proceeds to step T5, the process also proceeds to step T7 when the IDs do not match in step T5. In step T7, an error signal is output from the error signal output unit 104 (fig. 4). In step T8, an error display (for example, display of no (normal) RF tag or the like) is performed in the error display unit 105 (fig. 4) based on the error signal output in step T7.

Next, in step T9, the solenoid is turned on. That is, the current is supplied to the solenoid body 40 of the electromagnetic solenoid 4 to move the rod 30 downward, whereby the lock lever 31 is swung downward to move to the unlock position. The photoelectric sensors detect that the door has moved to the unlock position (see page 11, line 22 to page 12, line 1).

As described above, according to the present embodiment, a cam having a complicated shape is not required to lock the actuator 2, and therefore, the structure can be simplified. Further, since the actuator 2 is not directly locked by the lever 30, the lever 30 is not increased in size, and an increase in power consumption can be suppressed. Further, according to the present embodiment, since the lock lever 31 provided at the distal end 30a of the lever 30 locks the actuator 2, the actuator 2 can be reliably locked, and the reliability as the safety switch 1 can be improved. Further, according to the present embodiment, the RF tag 6 stores the ID information, and therefore, improper locking of the actuator 2 can be reliably prevented.

In the present embodiment, as shown in the flow of steps T1 to T9, a safety signal or an error signal is output based on the detection results of the position detection means including the photosensor 102 and the proximity detection means for RFID including the RF tag 6 and the RFID reader 7. As shown in the flow from step T1 to step T6, the present invention is configured such that: when the position detection means detects the swing position at the time of locking the lock lever 31, that is, the locking position, and the proximity detection means detects the proximity of the actuator 2 and the switch main body 3, the safety signal is output, and therefore, the reliability as the safety switch 1 can be further improved.

In the above-described embodiment 1, it is necessary to continuously supply current to the electromagnetic solenoid 4 during the door opening period, but this is not necessary in the embodiment 3, and current may be supplied to the electromagnetic solenoid 4 only when the locked state is released after an error occurs, and therefore, power can be saved.

Here, fig. 11A shows details of the normal operation and the abnormal operation of the safety switch 1.

No.1 to 3 in FIG. 11A show the normal operation of the safety switch 1. No.1 shows that before the locking bolt 21 is inserted into the switch main body 3 in the OPEN (OPEN) state, the solenoid main body 40 is not excited, the locking lever 31 is disposed at the override position beyond the locking position, the RFID is deactivated, the detection by the RFID is not performed, the door is in the unlocked state, and neither an error signal nor a safety signal is output (see step T1 in fig. 8 and 11). At this time, the machine inside the door stops operating. No.2 is a state in which the operation of the machine inside the door is stopped because the detection by the RFID is not performed because the solenoid main body 40 is not excited and the locking lever 31 is moved to the locking position by being pressed down by the locking bolt 21 while the door is transitioning from the OPEN (OPEN) state to the CLOSED (CLOSED) state of No.1 and while the locking bolt 21 is being inserted into the switch main body 3 (see step T2 in fig. 9 and 11). No.3 ends the insertion of the locking bolt 21 into the switch main body 3 in the door CLOSED (CLOSED) state shifted from No.2, the solenoid main body 40 is not excited, the locking lever 31 is placed in the locking position, and the RFID is activated as a trigger condition, whereby the detection is performed by the RFID, and at this time, the door is in the locking state, and a safety signal is output without outputting an error signal (refer to steps T3 to T6 in fig. 10 and 11), and the machine inside the door operates.

Nos. 4a, 4b, 5 of fig. 11A show abnormal actions of the safety switch 1. In the operation mode shown in No.4a, in the CLOSED door (CLOSED) state, the locking bolt 21 is inserted into the switch body 3 from the state where the solenoid body 40 is not excited and the locking lever 31 is disposed at the override position, and the locking bolt 21 is temporarily locked by the locking lever 31 (see steps T1 to T2 in fig. 8 to 10 and 11), and since the detection of the RF tag by the RFID in the active state is not performed, the solenoid body 40 is excited and the locking lever 31 is lowered (step T3 → T4 → T7 → T8 → T9 in fig. 11). At this time, an error signal that the RFID does not detect is output, and a safety signal is not output, so that the door is in an unlocked state and the machine inside the door stops operating. The operation form of No.4a is an example in which RFID is not detected, but the operation form shown in No.4b is an example in which RFID is different from ID, and the other conditions are the same as those of No. 4a. At this time, as in the case of No.4a, after the locking bolt 21 inserted into the switch main body 3 is temporarily locked by the locking lever 31 (see steps Tl to T2 in fig. 8 to 10 and 11), detection of a legitimate RF tag by the RFID in an active state is not performed, and therefore, the solenoid main body 40 is excited to lower the locking lever 31, the door is placed in an unlocked state, and an error signal having a different ID is output (see step T4 → T5 → T7 → T8 → T9 in fig. 11). The operation mode shown in No.5 is an example in which, in the CLOSED door (CLOSED) state, only the RF tag is brought close to the RFID reader without inserting the locking bolt 21 into the switch body 3 from the state in which the solenoid body 40 is not excited and the locking lever 31 is disposed at the override position (see step Tl in fig. 8 and 11), and at this time, the locking lever 31 is not moved to the locking position, and therefore, the program is stopped at step T2. At this time, the door is in an unlocked state, and neither an error signal nor a safety signal is output.

After the operation of the machine inside the door is stopped, an unlock button (not shown) can be operated, and if the unlock button is operated by an operator, current is supplied to the electromagnetic solenoid 4 to move the rod 30 downward, whereby the locked state of the lock rod 31 with respect to the locking bolt 21 is released. Thus, the door becomes unlocked and can be opened.

< example 4 >

In the above-described embodiments 1 to 3, an example in which an RFID is used as the approach detection means for detecting the approach state of the actuator 2 and the switch main body 3 is shown, but the application of the present invention is not limited to this. Other sensors (e.g., non-contact type ID sensors, etc.) may also be employed.

[ other modifications ]

All aspects of the embodiments and the modifications described above should be considered as mere examples of the present invention, and do not limit the present invention. It will be apparent to those skilled in the art to which the present invention relates that various modifications and other embodiments incorporating the principles of the invention can be constructed without departing from the spirit and essential characteristics of the invention in consideration of the above teachings, even if not explicitly described in the specification.

Industrial applicability

The present invention is useful for a safety switch in which the output state of the switch is switched by the cooperative operation of an actuator and a switch main body.

Claims

1. A safety switch for switching an output state of a switch by a cooperative operation of an actuator and a switch main body,

the actuator includes a locking bolt having a tip end portion insertable into the switch main body,

the switch main body has: a rod capable of reciprocating; and a lock lever provided at a distal end of the lever so as to be capable of swinging, and capable of locking the distal end portion of the locking bolt inserted into the switch main body.

2. The safety switch according to claim 1,

the locking bolt comprises: a shaft portion; and a lock lever disposed at a front end of the shaft portion and having a diameter larger than that of the front end portion of the shaft portion, the lock lever being configured to be lockable to a step between the front end portion and the shaft portion.

3. Safety switch according to claim 1 or 2,

the front end face of the front end portion of the locking bolt has a convex arc face or a tapered face.

4. A safety switch according to any one of claims 1 to 3,

the locking lever has: a shaft support part axially supported on the switch main body; and a locking projection capable of locking the distal end portion of the locking bolt in an engageable and disengageable manner, and is swingably engaged with the distal end of the lever at an intermediate position between the shaft support portion and the locking projection.

5. The safety switch according to any one of claims 1 to 4,

the locking lever is configured to be capable of being brought into a locking position for locking the distal end portion of the locking bolt and an unlocking position for releasing the locked state of the distal end portion by swinging in accordance with movement of the lever.

6. The safety switch according to claim 5,

when the tip end portion of the locking bolt is not inserted into the switch main body, the locking lever swings to an override position that overrides the locking position.

7. The safety switch according to claim 1,

the switch further includes a proximity detection mechanism that detects a proximity state of the actuator to the switch main body.

8. The safety switch according to claim 7,

the proximity detection mechanism has ID information.

9. The safety switch according to claim 1,

the position detecting mechanism detects the swing position of the locking lever.

10. The safety switch according to claim 1,

further comprising: an approach detection means for detecting an approach state of the actuator to the switch main body; and a position detection mechanism that detects a swing position of the lock lever,

and a safety signal or an error signal is output based on the detection results of the proximity detection means and the position detection means.

11. The safety switch according to claim 10,

when the approach detection means detects that the actuator approaches the switch body and the position detection means detects the swing position at the time of locking the lock lever, a safety signal is output.