JP2020190328A - Safety switch - Google Patents

Abstract

To perform release management of a stop state of a machine with high accuracy.SOLUTION: A safety switch 41 is used to release a stop state of a machine 4 installed in a restricted area 14. A reader of the safety switch 41 reads identification information of each operator from an RF tag for an operator and acquires the identification information as read ID information by confirmation operation of each operator. An ID information registration part registers the identification information of each operator as registration ID information in a list in the case that entrance/exit information acquired on the basis of the confirmation operation of each operator shows entry. An ID information deletion part deletes registration ID information corresponding to the read ID information of each operator from the list in the case that the entrance/exit information shows exit. A release permission part permits the release of a stop state of the machine 4 in the case that any registration ID information is not included in the list. Thus, release management of the stop state of the machine 4 arranged in the restricted area 14 can be performed with high accuracy.SELECTED DRAWING: Figure 1

Description

The present invention relates to a safety switch.

Conventionally, a safety switch is provided at the entrance / exit of a room where machines such as industrial machines are installed. When the door of the doorway is opened, the safety switch makes it impossible to supply power to the machine, and the machine is stopped. In the case of machine maintenance, etc., when an operator works in the above room, it is necessary to surely maintain the stopped state of the machine.

Therefore, Patent Document 1 discloses a safety holder (also referred to as a lock hasp) that blocks the actuator insertion port of the safety switch to prevent the internal drive cam from rotating. A plurality of holes are provided in the safety holder, and a plurality of workers individually lock the holes with a padlock before the start of the work, and each worker unlocks the padlock after the work is completed. As a result, the safety holder is kept attached to the safety switch until the last padlock is released, and the safety of the operator is ensured. A method in which each worker secures his / her own safety by using a padlock or the like as in Patent Document 1 is also called hostage control.

On the other hand, Patent Document 2 relates to a safety control system for safely operating a robot or the like by using a portable operation terminal such as a pendant or a grip switch. In the safety control system, the ID number of the pendant located in the operable area of the robot is transmitted to the robot via RFIC, and only the pendant with the ID number registered in the registration list is enabled to operate the robot. To.

JP-A-2007-73229 Japanese Unexamined Patent Publication No. 2009-301271

By the way, in the method of Patent Document 1, it is necessary to prepare a padlock and a key for each worker, and the management of the padlock and the key becomes complicated. In addition, there is a risk that the stopped state of the machine will be released by the key duplicated without permission, and in this case, the safety of the operator will be threatened. Further, when a lock hasp is attached to the safety switch and a plurality of padlocks are applied to the lock hasp, there is a problem that a large load is applied to the switch.

The present invention has been made in view of the above problems, and a main object of the present invention is to perform highly accurate release management of a stopped state of a machine.

The invention according to claim 1 is provided outside or inside a restricted area surrounded by a fence or a wall and restricted from entering, except for an entrance / exit provided with a door, and a machine installed in the restricted area is stopped. It is a safety switch used to release the state, and by the confirmation operation of each worker before entering the restricted area and after leaving the restricted area, the RF tag possessed by each worker can be used for each worker. An ID information acquisition unit that reads identification information and acquires it as read ID information, and indicates that each worker enters or exits the restricted area, which is acquired based on the confirmation operation of each worker. When the entry / exit information indicates entry, the ID information registration unit that registers the identification information of each worker in the list as the registration ID information based on the read ID information of each worker, and the ID information registration unit of each worker. When the entry / exit information acquired based on the confirmation operation indicates exit, the ID information deletion unit that deletes the registration ID information corresponding to the read ID information of each worker from the list, or the list. When the registration ID information of the above is not included, the release permission unit for permitting the release of the stopped state of the machine is provided.

The invention according to claim 2 is the safety switch according to claim 1, which detects an open / closed state of the door based on information read from an RF tag for a door provided on the door. It also has a part.

The invention according to claim 3 is the safety switch according to claim 2, and the reading of information from the door RF tag is performed by the ID information acquisition unit.

The invention according to claim 4 is the safety switch according to any one of claims 1 to 3, further comprising an engaging portion capable of locking the door.

The invention according to claim 5 is the safety switch according to claim 4, wherein the door is unlocked and the list does not include any registration ID information. The joint is further provided with a lock control unit that allows the door to be locked.

The invention according to claim 6 is the safety switch according to claim 4 or 5, which is acquired based on the confirmation operation of one operator in a state where the door is locked by the engaging portion. When the entry / exit information indicates entry, the presence / absence of the entry authority of the worker to the restricted area is confirmed based on the reading ID information of the worker, and when the entry authority is given, the door of the door A lock control unit that releases the lock and maintains the lock of the door when the worker does not have the access authority is further provided, and the ID information registration unit provides identification information of the worker when the worker has the access authority. Is registered in the list, and the identification information of the worker is not registered in the list when the person does not have the access authority.

The invention according to claim 7 is the safety switch according to any one of claims 1 to 6, and when a release of the stopped state of the machine is requested, one operator confirms the operation. Then, the release permission unit confirms the presence or absence of the stop release authority of the worker based on the read ID information of the worker, the worker has the stop release authority, and any of the above lists When the registration ID information of the above is not included, the release of the stopped state of the machine is permitted.

The invention according to claim 8 is the safety switch according to any one of claims 1 to 7, wherein the number of registered ID information included in the list or the worker indicated by the registered ID information is defined. A notification unit for notifying the information to be specified is further provided.

In the present invention, it is possible to perform highly accurate release management of the stopped state of the machine.

It is a top view of the restriction area where a safety switch is provided. It is a top view which shows the safety switch. It is a block diagram which shows the functional structure of a safety switch. It is a figure which shows the flow of the process which concerns on the entry and exit of the restricted area of a worker, and the release of a stopped state of a machine. It is a figure which shows the flow of the worker authentication process.

FIG. 1 is a plan view of a restricted area 14 provided with a safety switch 41 according to an embodiment of the present invention. The restricted area 14 is, for example, a part of the factory area. The restricted area 14 is an area that is partitioned from the surroundings by a fence or wall (hereinafter, also referred to as “partition 140”) shown by a thick solid line in FIG. 1, and human entry is restricted. An industrial machine 4 is installed in the restricted area 14, and an operator enters during maintenance of the machine 4.

A doorway 141 is provided in the partition 140 surrounding the restricted area 14. The doorway 141 is provided with a door 142 that opens and closes the doorway 141. In other words, the restricted area 14 is surrounded by a partition 140, except for the doorway 141 provided with the door 142. A safety switch 41 located outside the restricted area 14 is provided in the vicinity of the doorway 141. The safety switch 41 is used to shift the machine 4 to a stopped state (that is, a state in which it cannot be driven) and to release the stopped state. The safety switch 41 may be provided inside the restricted area 14.

FIG. 2 is a plan view showing the safety switch 41. FIG. 2 also shows configurations other than the safety switch 41. Further, in FIG. 2, a state in which the door 142 is slightly opened is shown by a solid line, and a state in which the door 142 is closed is shown by a two-dot chain line. As shown in FIGS. 1 and 2, the safety switch 41 includes a switch body 411, an actuator 412, and a touch panel 417. The switch body 411 is fixed to a portion of the partition 140 near the side edge of the entrance / exit 141, for example, outside the restricted area 14. The actuator 412 is fixed to, for example, a portion near the side edge of the door 142. The touch panel 417 is connected to the switch body 411 via, for example, USB or the like. The touch panel 417 may be fixed to a portion of the partition 140 near the entrance / exit 141.

When the door 142 of the doorway 141 is closed, the actuator 412 is inserted into the opening 413 (that is, the actuator insertion slot) of the switch body 411, as shown by the alternate long and short dash line in FIG. 2, and the machine 4 (see FIG. 1). ) Can be supplied with power. Further, by inserting the actuator 412 into the opening 413, the locking member 414 provided inside the switch body 411 engages with a part of the actuator 412. As a result, the actuator 412 cannot be pulled out, and the door 142 is locked by the safety switch 41. That is, in the safety switch 41, the locking member 414 and the actuator 412 are engaging portions 419 that can lock the door 142. The locking mechanism of the safety switch 41 may have various structures. For example, the lock mechanism of the safety switch 41 may be a spring lock type or a solenoid lock type.

In the safety switch 41, the locking member 414 of the switch body 411 can be separated from the actuator 412 by inputting the unlocking signal described later, and the door 142 is unlocked. Further, at the same time when the door 142 is unlocked, the electric power cannot be supplied to the machine 4, and the machine 4 is stopped. Then, when the door 142 is opened with the door 142 unlocked, the actuator 412 is pulled out from the opening 413 of the switch body 411.

The switch body 411 of the safety switch 41 includes a reader 415 and a control unit 416. The reader 415 and the control unit 416 are housed inside the housing of the switch body 411, for example.

The reader 415 is an RF reader / writer device that reads information from an RF tag (that is, Radio Frequency Tag) by wireless communication in a non-contact state or a contact state. An RF tag is a small electronic component that combines an IC chip (that is, an integrated circuit) and an antenna. In the RF tag, for example, the IC chip and the antenna are built in the resin outer body. The shape of the exterior body can be changed in various ways such as a button type or a card type. The RF tag is also called an IC tag or an IC card. The RF tag stores identification information and the like for distinguishing from other RF tags.

The control unit 416 processes the information read from the RF tag by the reader 415. Each function described later of the control unit 416 is realized by, for example, an electric circuit. The touch panel 417 is a notification unit that displays the result of information processing by the control unit 416 and notifies the operator. The touch panel 417 is also an input unit that receives input from an operator. Information processing by the control unit 416 and the display contents of the touch panel 417 will be described later. Each function of the control unit 416 may be realized by a configuration other than an electric circuit (for example, a normal computer system).

The actuator 412 of the safety switch 41 is provided with an RF tag 418 for detecting the opening and closing of the door 142. In the following description, the RF tag 418 is also referred to as a "door RF tag 418". The door RF tag 418 is, for example, a button-type RF tag, and is fixed to the actuator 412 so as to face the switch body 411 when the door 142 is closed. The door RF tag 418 is indirectly attached to the door 142 via the actuator 412, but may be directly attached to the door 142 without the actuator 412. That is, the door RF tag 418 may be provided on the door 142.

The door RF tag 418 stores, for example, identification information indicating that the RF tag is provided on the door 142. When the door 142 is closed and the actuator 412 is inserted into the opening 413 of the switch body 411, the identification information stored in the door RF tag 418 becomes readable by the reader 415. On the other hand, when the door 142 is opened and the actuator 412 is separated from the switch body 411, the distance between the door RF tag 418 and the reader 415 is larger than the readable distance of the reader 415. The identification information of the RF tag 418 becomes unreadable. The readable distance of the reader 415 is, for example, about 5 cm or less. The readable distance may be changed in various ways. The door RF tag 418 may store information other than the identification information of the door 142.

The reader 415 can also read information stored in RF tags (for example, an ID card having an IC chip and an antenna built-in) held by a plurality of workers. The RF tag (hereinafter, also referred to as “worker RF tag”) stores the identification information (that is, ID information) of the worker who is the owner in advance. The identification information is, for example, an identification number such as an employee number of each worker. When entering or exiting the restricted area 14, the operator performs a confirmation operation of bringing his / her own RF tag for the operator into contact with the switch body 411. The outer surface of the switch body 411 may be provided with a mark such as a character or a figure indicating a position where the RF tag for an operator is brought into contact with the switch body 411. When the above-mentioned confirmation operation is performed, the reader 415, which is the ID information acquisition unit, reads the worker's identification information from the worker's RF tag for the worker and transmits the identification information to the control unit 416.

FIG. 3 is a block diagram showing a functional configuration realized by the control unit 416 of the safety switch 41. FIG. 3 also shows configurations other than the control unit 416. The control unit 416 includes an access control unit 461, a release permission unit 464, an open / close state detection unit 465, a lock control unit 466, and a display control unit 468. The access control unit 461 includes an ID information registration unit 462 and an ID information deletion unit 463. The control unit 416 can communicate with the authentication device 6 arranged outside the switch main body 411 via the communication unit 61.

In the restricted area 14 shown in FIG. 1, predetermined work is performed by a plurality of workers during maintenance of the machine 4. When the worker enters the restricted area 14, the machine 4 installed in the restricted area 14 is stopped. It is necessary to maintain the stopped state of the machine 4 while the worker remains in the restricted area 14 in order to ensure the safety of the worker. In other words, when the stopped state of the machine 4 is released and the machine 4 is restarted, it is required that no worker remains in the restricted area 14.

Next, the process of entering and exiting the restricted area 14 of the operator and stopping the machine 4 will be described with reference to FIGS. 4 and 5. In the restricted area 14 shown in FIG. 1, the door 142 of the doorway 141 is locked by the safety switch 41. When the operator enters the restricted area 14 from the outside (FIG. 4: step S11), the operator operates the touch panel 417 or the like of the safety switch 41 to input an input indicating entry into the restricted area 14. The input is, for example, a tap of a button displayed on the touch panel 417 or an operation of a changeover switch provided on the switch body 411, and is included in a confirmation operation associated with entering and exiting the restricted area 14. As a result, the control unit 416 shown in FIG. 3 starts acquiring entry / exit information indicating entry of the worker into the restricted area 14. Subsequently, the worker authentication process is performed using the above-mentioned RF tag for the worker (step S12).

In the worker authentication process, the reader 415 reads the worker's identification information and acquires the identification information as the read ID information by touching or bringing the worker's RF tag held by the worker into contact with or close to the switch body 411 (. FIG. 5: Step S121). The read ID information acquired by the reader 415 is input to the control unit 416 and transmitted to the authentication device 6 via the communication unit 61. At this time, the identification information of the restricted area 14 is also transmitted to the authentication device 6.

The authentication device 6 has a database in which identification information of a large number of workers is registered. In the database, the identification information of each worker is associated with the authority information indicating the presence or absence of various authorities in the worker. The authority information includes, for example, the presence / absence of access authority to the restricted area 14, the presence / absence of access authority to other restricted areas, and the like. The authentication device 6 collates the read ID information transmitted from the control unit 416 with the identification information of a large number of workers registered in the database. In other words, the authentication device 6 authenticates the read ID information (step S122).

When the identification information that matches the read ID information is specified in the database and the authentication is successful, the authentication information including the worker's authority information associated with the conformity ID information is used as the conformity ID information, and the safety switch 41 Is transmitted to the control unit 416 of the above (step S123). Further, in the database, the identification information of the restricted area 14 is associated with the conformity ID information. As a result, the identification information collated with the read ID information in the database at the time of the worker authentication process at the time of exiting from the restricted area 14 described later is limited to the one associated with the identification information of the restricted area 14. As a result, the read ID information can be authenticated in a short time. If the conforming ID information is already associated with identification information such as another restricted area (that is, when it is determined that the worker has entered another restricted area or the like), authentication fails. Then, the authentication failure signal described later is transmitted to the control unit 416.

Upon receiving the authentication information from the authentication device 6, the control unit 416 causes the touch panel 417 to display a display indicating that the authentication is successful (for example, a green "OK" character or the like). As a result, the success of the authentication is notified to the worker (step S124). Note that the notification of successful authentication to the worker may be performed by various other methods such as a beep sound and lighting of a lamp.

When the authentication information received by the control unit 416 includes information indicating that the user has the authority to enter the restricted area 14 (hereinafter, also referred to as “access permission information”), the lock control unit 466 to the engaging unit 419 An unlock signal is sent to. Then, by driving the engaging portion 419, the lock of the door 142 is released, and the operator can enter the restricted area 14. On the other hand, when the authentication information received by the control unit 416 does not include the entry permission information, the locked state of the door 142 does not change and the lock is maintained. In this case, the touch panel 417 displays a display indicating that unlocking is not permitted (for example, yellow "NG" characters, etc.).

Further, in the authentication by the authentication device 6, if the identification information matching the read ID information does not exist in the database, the authentication failure signal indicating the authentication failure is transmitted to the control unit 416 of the safety switch 41 (step). S123). When the control unit 416 receives the authentication failure signal from the authentication device 6, the touch panel 417 displays a display indicating the authentication failure (for example, red "ERROR" characters or the like). As a result, the failure of authentication is notified to the worker (step S125). It should be noted that the notification of the authentication failure to the worker may be performed by various other methods such as a beep sound and lighting of a lamp. Even if the worker authentication fails, the locked state of the door 142 does not change and the lock is maintained.

In this way, in the control unit 416, the lock control unit 466 confirms whether or not the worker has the authority to enter the restricted area 14 based on the read ID information of the worker. Then, if the worker has access authority, the door 142 is unlocked. On the other hand, if the worker does not have access authority (including the case where the worker is not registered in the database), the lock of the door 142 is maintained.

In the worker authentication process in step S12, when the worker is successfully authenticated and the access permission information is included in the authentication information, the work included in the authentication information is performed by the ID information registration unit 462 of the access control unit 461. The identification information of the person is registered in the list 467 as the registration ID information (FIG. 4: step S13). In step S13, the entry / exit information is acquired based on the confirmation operation of the worker (that is, the reading of the RF tag for the worker), and it is also confirmed that the entry / exit information indicates entry. The above-mentioned list 467 is, for example, a storage area provided in the control unit 416. The ID information registration unit 462 may register the read ID information acquired by the reader 415 in the list 467 as the registration ID information. In other words, in step S13, when the worker has the authority to enter the restricted area 14, the identification information of the worker is registered in the list 467 as the registration ID information based on the read ID information of the worker.

On the other hand, when the worker does not have the access authority to the restricted area 14 (that is, when the authentication information does not include the access permission information or when the worker authentication fails), the ID information registration unit 462 Does not register the worker's identification information in Listing 467. In FIG. 4, the illustration of the process when the worker does not have the authority to enter the restricted area 14 is omitted.

In the present embodiment, the processes of steps S11 to S13 are performed for all the workers who enter the restricted area 14. Then, the identification information of all the workers who enter the restricted area 14 is registered in the list 467 as the registration ID information. When the worker has finished entering the restricted area 14, for example, the door 142 of the doorway 141 is closed (that is, the actuator 412 is inserted into the opening 413 of the switch body 411) and the door 142 is automatically locked. The door. As a result, it is possible to prevent an unauthorized worker or the like from entering the restricted area 14. On the other hand, from the viewpoint of preventing the operator from being confined in the restricted area 14, the door 142 is left open or the door 142 is not locked while the operator is entering the restricted area 14. May be good.

When the operator exits the restricted area 14 (step S14), the door 142 is unlocked by a release switch or the like (not shown) provided in the vicinity of the doorway 141 in the restricted area 14, and the operator exits the restricted area 14. To do. If the door 142 remains open or is not locked, it is not necessary to release the lock. Subsequently, outside the restricted area 14, the operator operates the touch panel 417 of the safety switch 41, the changeover switch, or the like to perform an input indicating exit from the restricted area 14. As a result, the control unit 416 starts acquiring entry / exit information indicating exit from the restricted area 14 of the worker. Subsequently, the worker authentication process of FIG. 5 is performed (step S15). The content of the worker authentication process is the same as in step S12 described above, and when the authentication device 6 succeeds in authentication, the authentication information is transmitted to the control unit 416 of the safety switch 41.

The ID information deletion unit 463 of the access control unit 461 acquires entry / exit information based on the worker's confirmation operation (that is, reading the RF tag for the worker), and confirms that the entry / exit information indicates exit. , The registration ID information that matches the worker's identification information included in the authentication information is deleted from the list 467 (step S16). The ID information deletion unit 463 may delete the registered ID information that matches the read ID information acquired by the reader 415 from the list 467.

When the authentication device 6 fails to authenticate the read ID information, the ID information deletion unit 463 does not perform the process of deleting the registered ID information from the list 467. As described above, in FIG. 4, the illustration of the process when the authentication in the worker authentication process fails is omitted. When each worker exits the restricted area 14, the processes of steps S14 to S16 are performed. Therefore, at each time point, the only worker who has entered the restricted area 14 is the worker indicated by the registration ID information included in the list 467.

In the safety switch 41, the display control unit 468 displays the worker information indicated by the registered ID information included in the list 467 on the touch panel 417. The displayed worker information is information that identifies the worker, such as the worker's name and employee number. For example, on the touch panel 417, all the workers who may perform maintenance of the machine 4 and the like are displayed, and among all the workers, only the workers included in the list 467 are displayed in a different color from the other workers. May be done. Alternatively, the touch panel 417 may display only the number of registered ID information included in the list 467. In other words, the touch panel 417 is a notification unit that notifies the surroundings of the number of registered ID information included in the list 467 or the worker information indicated by the registered ID information.

The safety switch 41 may be provided with another notification unit instead of the touch panel 417. For example, a plurality of lamps may be provided as a notification unit, and the number of registered ID information included in the list 467 may be notified to the surroundings depending on the number of lamps that are lit. Alternatively, a speaker may be provided as a notification unit, and the number of registered ID information included in the list 467 or the information indicating the worker indicated by the registered ID information may be notified to the surroundings by voice.

When the operator exits the restricted area 14, the door 142 is closed and the actuator 412 is inserted into the opening 413 of the switch body 411. Further, the reader 415 of the switch body 411 reads the identification information indicating the door 142 from the door RF tag 418 provided on the actuator 412 and sends it to the control unit 416. In the control unit 416, the open / close state detection unit 465 that detects the open / closed state of the door 142 determines that the door 142 is closed.

Subsequently, when the lock control unit 466 confirms the list 467 and the list 467 does not include any registration ID information, the lock control unit 466 transmits a lock permission signal permitting the lock of the door 142 to the engaging unit 419. Will be done. Then, the door 142 is locked by the engaging portion 419, and the operator cannot enter the restricted area 14. On the other hand, when one or more registered ID information is included in the list 467 confirmed by the lock control unit 466, the lock permission signal is not transmitted from the lock control unit 466 and the door 142 is not locked. This prevents the operator from being trapped in the restricted area 14.

When all the workers leave the restricted area 14 and the door 142 is closed and locked as described above, the stopped state of the machine 4 in the restricted area 14 is released and the machine 4 is restarted. When releasing the stopped state of the machine 4 (step S17), for example, the operator requests the release of the stopped state of the machine 4 by operating the touch panel 417 of the safety switch 41 (that is, the machine 4). (Instructing restart) Input is performed. Subsequently, the cancellation permission unit 464 confirms the presence or absence of the registration ID information in the current list 467. Then, when none of the registration ID information is included in the list 467 (step S18), a permission signal for permitting the release of the stopped state of the machine 4 is output to the control device (not shown) of the machine 4 (step). S19).

In the control device, it has been confirmed that an input requesting the release of the stopped state of the machine 4 is performed, the above permission signal is input, and the door 142 is closed by reading the door RF tag 418. If so, the operation of the machine 4 is started. The operation of the machine 4 cannot be started only by closing the door 142 and inserting the actuator 412 into the opening 413. A permission signal from the release permission unit 464 is required to start the operation of the machine 4. Further, in the above control device, in addition to inputting the permission signal and confirming the closing of the door 142, after confirming that the door 142 is locked by the engaging portion 419, the operation of the machine 4 is restarted. May be good.

In the release permission unit 464, in addition to the absence of the registration ID information in the list 467, when it is confirmed by reading the door RF tag 418 that the door 142 is closed, a permission signal is sent to the control device. It may be output. Further, the release permission unit 464 outputs a permission signal to the control device when the registration ID information in the list 467 is absent, the door 142 is closed, and the door 142 is locked. May be good. When the release permission unit 464 confirms that the registration ID information in the list 467 does not exist and the door 142 is closed without input requesting the release of the stopped state of the machine 4. The permission signal may be output at all times. In this case, the operation of the machine 4 is started by inputting an operator instructing the restart of the machine 4 while the permission signal is being output.

On the other hand, when any of the registration ID information is included in the list 467 (step S18), the release permission unit 464 does not permit the release of the stopped state of the machine 4, and the permission signal is not output (step S20). Therefore, the stopped state of the machine 4 is maintained. That is, when the operator remains in the restricted area 14, the stopped state of the machine 4 is prevented from being released. At this time, the display control unit 468 displays on the touch panel 417 that the operator remains in the restricted area 14. When all the workers remaining in the restricted area 14 leave the restricted area 14 and the processes of steps S14 to S16 are performed, the list 467 does not include any registered ID information, and the machine 4 is stopped. The state can be released (steps S17 to S19).

In step S17, when the operator makes an input requesting the release of the stopped state of the machine 4, a confirmation operation for causing the reader 415 to read the operator's RF tag may be requested. In this case, the above-mentioned worker authentication process (steps S121 to S125) is performed based on the read ID information read by the reader 415, and the authentication information including the worker identification information and the authority information is transmitted to the control unit 416. Is sent. In the control unit 416, the presence or absence of the worker's suspension release authority is confirmed by the release permission unit 464 based on the authentication information. Then, when the worker has the authority to release the stop state of the machine 4 and the list 467 does not include any registration ID information as described above (step S18), the permission to permit the release of the stopped state of the machine 4 is permitted. A signal is output from the release permission unit 464 to the control device of the machine 4 (step S19). On the other hand, if the operator does not have the authority to release the stop of the machine 4, the permission signal is not output.

As described above, the safety switch 41 is provided outside or inside the restricted area 14 surrounded by a fence or wall (ie, partition 140) and restricted access, except for the doorway 141 provided with the door 142. Be done. The safety switch 41 is used to release the stopped state of the machine 4 installed in the restricted area 14. The safety switch 41 includes an ID information acquisition unit (that is, a reader 415), an ID information registration unit 462, an ID information deletion unit 463, and a release permission unit 464. The reader 415 identifies each worker from the RF tag (that is, the RF tag for the worker) possessed by each worker by the confirmation operation of each worker before entering the restricted area 14 and after leaving the restricted area 14. The information is read and acquired as read ID information. The ID information registration unit 462 registers identification information of each worker based on the read ID information of each worker when the entry / exit information acquired based on the confirmation operation of each worker indicates entry. Is registered in the list 467. The entry / exit information is information indicating that each worker enters or exits the restricted area 14. The ID information deletion unit 463 deletes the registered ID information corresponding to the read ID information of each worker from the list 467 when the entry / exit information acquired based on the confirmation operation of each worker indicates exit. The release permission unit 464 permits the release of the stopped state of the machine 4 when the list 467 does not include any of the registered ID information.

As a result, it is possible to perform highly accurate release management of the stopped state of the machine 4 arranged in the restricted area 14. Specifically, it is possible to prevent the machine 4 from being stopped in a state where an operator is present in the restricted area 14 with high accuracy. As a result, the safety in the restricted area 14 can be improved. Further, unlike the case where a lock hasp or a padlock is attached to the safety switch 41, it is possible to prevent a large load from being applied to the safety switch 41.

As described above, it is preferable that the safety switch 41 further includes an open / closed state detection unit 465 that detects the open / closed state of the door 142 based on the information read from the door RF tag 418 provided on the door 142. As a result, the open / closed state of the door 142 can be detected with high accuracy. Further, when the release permission unit 464 determines whether or not the stopped state of the machine 4 can be released, the open / closed state of the door 142 detected by the open / closed state detection unit 465 is taken into consideration, so that the stopped state of the machine 4 is released. Management can be performed with higher accuracy.

Further, the safety switch 41 mechanically detects that the actuator 412 has been inserted into the opening 413 of the switch body 411 by reading the identification information indicating the door 142 to detect the open / closed state, and opens / closes the door 142. Compared with the mechanism for detecting the state, the opening / closing management of the door 142 can be performed with high accuracy. Specifically, even if a member having the same shape as the actuator 412 is inserted into the opening 413, it is possible to prevent the closing of the door 142 from being erroneously detected. Further, since there is no concern about the above-mentioned erroneous detection due to imitation of the shape of the actuator 412, the shape of the actuator 412 can be simplified. As a result, the strength of the actuator 412 can be easily increased, and the manufacturing cost of the safety switch 41 can be reduced.

As described above, reading the information from the door RF tag 418 is preferably performed by the reader 415. In this way, the structure of the safety switch 41 is simplified by making the information stored in the RF tag for workers and the information stored in the RF tag 418 for doors readable by the same reader 415. Can be transformed into.

As described above, the safety switch 41 preferably further includes an engaging portion 419 that can lock the door 142. In this way, by making the lock mechanism of the door 142 also serve as the safety switch 41, it is possible to simplify the structure related to the access restriction of the restricted area 14. Further, the safety in the restricted area 14 can be further improved as compared with the case where the door 142 is not provided with the lock mechanism.

As described above, the safety switch 41 preferably further includes a lock control unit 466. The lock control unit 466 allows the engaging unit 419 to lock the door 142 when the door 142 is unlocked and the list 467 does not include any registration ID information. As a result, it is possible to prevent the operator from being confined in the restricted area 14.

As described above, the lock control unit 466 works when the door 142 is locked by the engaging unit 419 and the entry / exit information acquired based on the confirmation operation of one operator indicates entry. It is also preferable to confirm whether or not the operator has the right to enter the restricted area based on the person's read ID information. In this case, the lock control unit 466 unlocks the door 142 when the operator has the access authority, and maintains the lock of the door 142 when the operator does not have the access authority. As a result, it is possible to prevent an operator who does not have the access authority from entering the restricted area 14, and to manage the access to the restricted area 14 with high accuracy. Further, when a plurality of restricted areas 14 exist, by individually registering the access authority to each restricted area 14 for each worker in a database or the like, a plurality of restricted areas 14 can be used with one RF tag for one worker. Access to the database can be managed individually.

As described above, when the release of the stopped state of the machine 4 is requested, the confirmation operation of one worker is performed, and the release permission unit 464 performs the operation based on the read ID information of the worker. It is preferable to confirm whether or not the person has the authority to release the suspension. In this case, the release permission unit 464 permits the release of the stopped state of the machine 4 when the worker has the authority to release the stop and the list 467 does not include any of the registered ID information. As a result, it is possible to prevent an operator who does not have the authority to release the stop from releasing the stopped state of the machine 4, and to manage the release of the stopped state of the machine 4 with higher accuracy.

As described above, the safety switch 41 may further include a notification unit (for example, touch panel 417) that notifies the number of registered ID information included in the list 467 or the information that identifies the worker indicated by the registered ID information. preferable. As a result, the presence or absence of the worker in the restricted area 14 can be easily confirmed.

In the above example, the authentication device 6 is provided outside the switch body 411, receives read ID information from the readers 415 of the plurality of safety switches 41 provided in the plurality of restricted areas 14, and performs the worker authentication process. I do. The database in which the identification information of a large number of workers is registered is centrally stored only in the authentication device 6, and is not stored in each safety switch 41. As a result, it is possible to prevent the database from leaking to the outside. The safety switch 41 does not have to store the read ID information.

The database may be stored in the control unit 416 of the safety switch 41. In this case, the authentication device 6 may be omitted. Alternatively, worker identification information, authority information, and the like may be recorded on the worker RF tag of each worker. As a result, the database registration in the safety switch 41 and the authentication device 6 can be omitted, so that the degree of freedom of the operator's authority management can be improved.

The safety switch 41 described above can be changed in various ways.

For example, in step S11, a confirmation operation may be required to cause the reader 415 to read the worker RF tag of the worker when the input indicating entry into the restricted area 14 is performed. In this case, the above-mentioned worker authentication process (steps S121 to S125) is performed based on the read ID information read by the reader 415, and the authentication information including the worker identification information and the authority information is transmitted to the control unit 416. Is sent. The control unit 416 confirms whether or not there is an authority to start inputting the entry / exit information of the worker based on the authentication information. Then, when the worker has the authority to start inputting the entry / exit information, the reader 415 or the like can acquire the entry / exit information. On the other hand, if the worker does not have the authority to start inputting the entry / exit information, the entry / exit information cannot be acquired. The same applies to the case where the input indicating exit from the restricted area 14 is performed in step S14.

In the safety switch 41, the reading of the information from the door RF tag 418 may be performed by a reader different from the reader 415 used for reading the information from the worker RF tag.

The open / closed state of the door 142 does not necessarily have to be detected by using the door RF tag 418. For example, the door is mechanically detected that the actuator 412 has been inserted into the opening 413 of the switch body 411. It may be detected that 142 has been closed. In this case, the door RF tag 418 may be omitted from the door 142.

In the above example, it is confirmed whether or not the worker has the access authority to the restricted area 14 based on the read ID information read from the worker RF tag. For example, only the worker who has the access authority works. If the person has an RF tag, the confirmation of the presence / absence of the entry authority by the lock control unit 466 may be omitted.

The lock mechanism of the door 142 described above may be provided separately from the safety switch 41. Alternatively, the locking mechanism of the door 142 may be omitted.

The touch panel 417 may be provided, for example, on the outer surface of the housing of the switch body 411 (for example, the side surface opposite to the side surface facing the restricted area 14). In the safety switch 41, the notification unit such as the touch panel 417 may be omitted.

The above-described embodiments and configurations in the respective modifications may be appropriately combined as long as they do not conflict with each other.

4 Machine 14 Restricted area 41 Safety switch 140 Partition 141 Doorway 142 Door 415 Reader 417 Touch panel 418 Door RF tag 419 Engagement part 462 ID information registration part 463 ID information deletion part 464 Release permission part 465 Open / close state detection part 466 Lock control part 467 List S11-S20, S121-S125 Steps

Claims (8)

A safety switch that is provided outside or inside a restricted area surrounded by fences or walls except for doorways and is used to release the stopped state of machines installed in the restricted area. There,
An ID that reads the identification information of each worker from the RF tag possessed by each worker and acquires it as read ID information by the confirmation operation of each worker before entering the restricted area and after leaving the restricted area. Information acquisition department and
The reading of each worker when the entry / exit information indicating entry into or exit from the restricted area of each worker, which is acquired based on the confirmation operation of each worker, indicates entry. An ID information registration unit that registers the identification information of each worker in a list as registration ID information based on the ID information.
When the entry / exit information acquired based on the confirmation operation of each worker indicates exit, an ID information deletion unit that deletes the registered ID information corresponding to the read ID information of each worker from the list. ,
When the list does not include any of the registered ID information, the release permission unit that permits the release of the stopped state of the machine and the release permission unit.
A safety switch characterized by being equipped with. The safety switch according to claim 1.
A safety switch further comprising an open / closed state detection unit that detects an open / closed state of the door based on information read from an RF tag for the door provided on the door. The safety switch according to claim 2.
A safety switch characterized in that the reading of information from the door RF tag is performed by the ID information acquisition unit. The safety switch according to any one of claims 1 to 3.
A safety switch further comprising an engaging portion that can lock the door. The safety switch according to claim 4.
When the door is unlocked and the list does not include any of the registered ID information, the engaging portion is further provided with a lock control unit that allows the door to be locked. Safety switch. The safety switch according to claim 4 or 5.
When the entrance / exit information acquired based on the confirmation operation of one worker indicates entry while the door is locked by the engaging portion, based on the reading ID information of the worker. A lock control unit that confirms the presence or absence of the worker's access authority to the restricted area, unlocks the door when the operator has the access authority, and maintains the lock of the door when the worker does not have the access authority. Further prepare
The ID information registration unit registers the identification information of the worker in the list when the worker has the entry authority, and does not register the identification information of the worker in the list when the worker does not have the entry authority. A safety switch that features that. The safety switch according to any one of claims 1 to 6.
When the release of the stopped state of the machine is requested, a confirmation operation of one worker is performed, and the release permission unit has the authority to release the stop of the worker based on the read ID information of the worker. A safety switch characterized by confirming the presence or absence and permitting the release of the stopped state of the machine when the worker has the authority to release the stop and the list does not include any registered ID information. .. The safety switch according to any one of claims 1 to 7.
A safety switch further comprising a notification unit that notifies the number of registered ID information included in the list or information that identifies an operator indicated by the registered ID information.

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