JP7350516B2 - Safety switches and controls - Google Patents

Description

The present invention relates to safety switches and control devices .

Conventionally, safety switches are provided at the entrances and exits of rooms where machines such as industrial machines are installed. When the entrance/exit door is opened, a safety switch disables power supply to the machine and the machine is stopped. In the case of machine maintenance, etc., when a worker works in the room, it is necessary to reliably maintain the stopped state of the machine.

Therefore, Patent Document 1 discloses a safety retainer (also called a lock hasp) that blocks the actuator insertion port of the safety switch to prevent rotation of the internal drive cam. The safety retainer has a plurality of holes, and a plurality of workers individually lock the holes with padlocks before starting work, and each worker releases the padlocks after the work is completed. As a result, the safety retainer remains attached to the safety switch until the last padlock is released, ensuring the safety of the worker. As in Patent Document 1, a method in which each worker uses a padlock or the like to ensure his/her own safety 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 using a portable operating terminal such as a pendant or a grip switch. In this safety control system, the ID numbers of pendants located in the operable area of the robot are transmitted to the robot via RFIC, and only pendants with ID numbers registered in the registration list are enabled to operate the robot. Ru.

Japanese Patent Application Publication No. 2007-73229 Japanese Patent Application 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, which makes management of the padlock and keys complicated. Additionally, there is a risk that the machine may be brought out of a stopped state by a key that has been copied without permission, and in this case, the safety of the worker is endangered. Furthermore, when a lock hasp is attached to a safety switch and a plurality of padlocks are attached to the lock hasp, there is a problem in that a large load is applied to the switch.

The present invention has been made in view of the above-mentioned problems, and its main purpose is to manage the release of a stopped state of a machine with high precision.

The invention according to claim 1 is provided outside or inside a restricted area where access is restricted by being surrounded by a fence or wall except for an entrance provided with a door, and the stoppage of a machine installed in the restricted area is provided. The safety switch is used to release the state, and each worker's confirmation operation before entering the restricted area and after exiting the restricted area allows each worker's information to be detected from the RF tag held by each worker. an ID information acquisition unit that reads identification information and acquires it as read ID information; and an ID information acquisition unit that indicates each worker's entry into or exit from the restricted area, which is acquired based on the confirmation operation of each worker. an ID information registration unit that registers identification information of each worker in a list as registered ID information based on the read ID information of each worker when the entry/exit information indicates entry; an ID information deletion unit that deletes registered ID information corresponding to the read ID information of each worker from the list when the entry/exit information obtained based on the confirmation operation indicates exit; If registered ID information of the machine is not included, the opening/closing state of the door is determined based on the information read from the door RF tag provided on the door and the release permission section that permits the cancellation of the stopped state of the machine. An open/closed state detection section for detecting the open/closed state is provided.

The invention according to claim 2 is the safety switch according to claim 1 , in which the information from the door RF tag is read by the ID information acquisition section.

The invention according to claim 3 is the safety switch according to claim 1 or 2 , further comprising an engaging part capable of locking the door.

The invention according to claim 4 is the safety switch according to claim 3 , in which when the door is unlocked and the list does not include any registered ID information, The apparatus further includes a lock control section that allows the door to be locked at the joint.

The invention according to claim 5 is the safety switch according to claim 3 or 4 , wherein the safety switch is obtained based on a confirmation operation of one worker while the door is locked by the engaging portion. If the entry/exit information indicates entry, it is confirmed whether or not the worker has the authority to enter the restricted area based on the read ID information of the worker, and if the worker has the authority to enter, the door is closed. further comprising a lock control unit that releases the lock and maintains the lock of the door when the door does not have the entry authority; is registered in the list, and identification information of the worker is not registered in the list if he does not have the access authority.
The invention according to claim 6 is a control device for controlling the operation of a machine, wherein the release permission section of the safety switch according to any one of claims 1 to 5 cancels the stopped state of the machine. The operation of the machine is started in response to a permission signal for permission and a detection result that the door is in a closed state by the opening/closing state detection section.

The invention according to claim 7 is provided outside or inside a restricted area where entry is restricted by being surrounded by a fence or wall except for an entrance/exit provided with a door, and the stoppage of a machine installed in the restricted area is provided. The safety switch is used to release the state, and each worker's confirmation operation before entering the restricted area and after exiting the restricted area allows each worker's information to be detected from the RF tag held by each worker. an ID information acquisition unit that reads identification information and acquires it as read ID information; and an ID information acquisition unit that indicates each worker's entry into or exit from the restricted area, which is acquired based on the confirmation operation of each worker. an ID information registration unit that registers identification information of each worker in a list as registered ID information based on the read ID information of each worker when the entry/exit information indicates entry; an ID information deletion unit that deletes registered ID information corresponding to the read ID information of each worker from the list when the entry/exit information obtained based on the confirmation operation indicates exit; a cancellation permission unit that permits cancellation of the stopped state of the machine when the registered ID information of the machine is not included; is performed, and the cancellation permission unit checks whether or not the worker has suspension cancellation authority based on the read ID information of the worker, and determines whether the worker has suspension cancellation authority and is included in the list. If no registered ID information is included, the machine is permitted to be released from the stopped state.

The invention according to claim 8 is the safety switch according to any one of claims 1 to 5 and claim 7, in which the number of registered ID information included in the list or the registered ID information is The apparatus further includes a notification section configured to notify information for specifying the worker who is assigned to the job.

According to the present invention, it is possible to manage the release of a stopped state of a machine with high precision.

FIG. 3 is a plan view of a restricted area in which a safety switch is provided; FIG. 3 is a plan view showing the safety switch. FIG. 2 is a block diagram showing the functional configuration of a safety switch. FIG. 2 is a diagram showing the flow of processing related to entry and exit of a worker into a restricted area and cancellation of a stopped state of a machine. FIG. 3 is a diagram showing the flow of worker authentication processing.

FIG. 1 is a plan view of a restricted area 14 in which a safety switch 41 according to one embodiment of the present invention is provided. The restricted area 14 is, for example, a part of a factory. The restricted area 14 is an area that is partitioned off from the surrounding area by a fence or wall (hereinafter also referred to as "partition 140") indicated by a thick solid line in FIG. 1, and is an area where human access is restricted. In the restricted area 14, an industrial machine 4 is installed, and a worker enters the machine 4 for maintenance or the like.

An entrance/exit 141 is provided in a partition 140 surrounding the restricted area 14 . The entrance/exit 141 is provided with a door 142 for opening/closing the entrance/exit 141 . In other words, the restricted area 14 is surrounded by the partition 140 except for the entrance/exit 141 where the door 142 is provided. A safety switch 41 located outside the restricted area 14 is provided near the entrance/exit 141 . The safety switch 41 is used to shift the machine 4 to a stopped state (that is, to a non-driveable state) and to cancel the stopped state. Note that the safety switch 41 may be provided inside the restricted area 14.

FIG. 2 is a plan view showing the safety switch 41. In FIG. 2, configurations other than the safety switch 41 are also shown. Further, in FIG. 2, a solid line indicates a state in which the door 142 is slightly opened, and a two-dot chain line indicates a state in which the door 142 is closed. 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, for example, to a portion of the partition 140 near the side edge of the entrance/exit 141 outside the restricted area 14 . The actuator 412 is fixed to a portion near the side edge of the door 142, for example. The touch panel 417 is connected to the switch body 411 via a USB or the like, for example. 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 entrance/exit 141 is closed, the actuator 412 is inserted into the opening 413 (i.e., actuator insertion port) of the switch body 411, as shown by the two-dot chain line in FIG. ). Further, by inserting the actuator 412 into the opening 413, a locking member 414 provided inside the switch body 411 engages with a portion of the actuator 412. This makes it impossible to remove the actuator 412, and the safety switch 41 locks the door 142. That is, in the safety switch 41, the locking member 414 and the actuator 412 are an engaging portion 419 that can lock the door 142. The locking mechanism of 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 a lock release signal, which will be described later, and the door 142 is unlocked. Furthermore, at the same time as the door 142 is unlocked, power cannot be supplied to the machine 4, and the machine 4 becomes stopped. When the door 142 is opened with the door 142 unlocked, the actuator 412 is removed 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 section 416. The reader 415 and the control unit 416 are housed inside the casing of the switch body 411, for example.

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

The control unit 416 processes the information read from the RF tag by the reader 415. Each function of the control unit 416, which will be described later, is realized by, for example, an electric circuit. The touch panel 417 is a notification unit that displays the results of information processing by the control unit 416 and notifies the operator. Furthermore, the touch panel 417 is also an input unit that receives input from the operator. Information processing by the control unit 416, display contents of the touch panel 417, etc. will be described later. Note that 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 opening/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-shaped RF tag, and is fixed to the actuator 412 so as to face the switch body 411 when the door 142 is closed. Although the door RF tag 418 is indirectly attached to the door 142 via the actuator 412, it may be attached directly to the door 142 without using the actuator 412. That is, the door RF tag 418 only needs to be provided on the door 142.

The door RF tag 418 stores, for example, identification information indicating that it is an RF tag 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 can be read by the reader 415. On the other hand, when the door 142 is opened and the actuator 412 is away from the switch body 411, the distance between the door RF tag 418 and the reader 415 becomes larger than the readable distance of the reader 415, so the door 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. Note that 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, ID cards with built-in IC chips and antennas) held by multiple workers. The RF tag (hereinafter also referred to as "worker RF tag") stores in advance identification information (i.e., ID information) of the worker who is the owner. 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, each worker performs a confirmation operation by touching the switch body 411 with his or her own worker RF tag. The outer surface of the switch body 411 may be provided with a mark such as a letter or a figure indicating a position to be contacted with the worker's RF tag. When the above-described confirmation operation is performed, the reader 415, which is an ID information acquisition unit, reads the identification information of the worker from the worker's RF tag and transmits it to the control unit 416.

FIG. 3 is a block diagram showing a functional configuration realized by the control section 416 of the safety switch 41. As shown in FIG. FIG. 3 also shows configurations other than the control unit 416. The control unit 416 includes an access management 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 entry management section 461 includes an ID information registration section 462 and an ID information deletion section 463. The control unit 416 can communicate with the authentication device 6 disposed outside the switch 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 and the like. When a worker enters the restricted area 14, the machine 4 installed in the restricted area 14 is stopped. Maintaining the machine 4 in a stopped state while the worker remains in the restricted area 14 is necessary 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 within the restricted area 14.

Next, processing related to entry and exit of the worker into the restricted area 14 and stopping of the machine 4 will be explained with reference to FIGS. 4 and 5. In the restricted area 14 shown in FIG. 1, a door 142 of an entrance/exit 141 is locked by a safety switch 41. When a worker 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 to the restricted area 14. The input is, for example, a tap on a button displayed on the touch panel 417 or an operation on a changeover switch provided on the switch body 411, and is included in the 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 the worker's entry into the restricted area 14. Next, a worker authentication process is performed using the above-mentioned worker RF tag (step S12).

In the worker authentication process, the reader 415 reads the worker's identification information by bringing the worker's RF tag into contact with or near the switch body 411, and acquires the identification information as read ID information ( 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 this database, each worker's identification information is associated with authority information indicating whether or not the worker has various authorities. The authority information includes, for example, the presence or absence of the authority to enter the restricted area 14 and the presence or absence of the authority to enter other restricted areas. The authentication device 6 compares 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 identification information that matches the read ID information is identified in the database and authentication is successful, the identification information is used as compatible ID information, and the authentication information including the operator's authority information associated with the compatible ID information is transferred to the safety switch 41. is transmitted to the control unit 416 (step S123). Further, in the database, the identification information of the restricted area 14 is associated with the matching ID information. As a result, the identification information that is checked against the read ID information in the database during worker authentication processing upon exiting the restricted area 14, which will be described later, is limited to that associated with the identification information of the restricted area 14. As a result, authentication of the read ID information can be performed in a short time. In addition, if the identification information of another restricted area, etc. is already associated with the conforming ID information (i.e., if it is determined that the worker is entering another restricted area, etc.), authentication will fail. Then, an authentication failure signal, which will be described later, is transmitted to the control unit 416.

When the control unit 416 receives the authentication information from the authentication device 6, the control unit 416 causes the touch panel 417 to display a display indicating successful authentication (for example, a green character "OK", etc.). Thereby, the success of 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 or lighting of a lamp.

If the authentication information received by the control unit 416 includes information indicating that you have the authority to enter the restricted area 14 (hereinafter also referred to as “access permission information”), the lock control unit 466 sends the information to the engagement unit 419. An unlock signal is sent to Then, by driving the engaging portion 419, the door 142 is unlocked, allowing the operator to enter the restricted area 14. On the other hand, if the authentication information received by the control unit 416 does not include entry permission information, the locked state of the door 142 does not change and remains locked. In this case, a display indicating that unlocking is not permitted (for example, yellow "NG" characters, etc.) is displayed on the touch panel 417.

Further, in the authentication by the authentication device 6, if identification information matching the read ID information does not exist in the database, an 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, it causes the touch panel 417 to display a display indicating the authentication failure (for example, the words "ERROR" in red, etc.). As a result, the worker is notified of the authentication failure (step S125). Note that the notification of the authentication failure to the operator may be performed by various other methods such as a beep sound or lighting of a lamp. Even if the operator's authentication fails, the locked state of the door 142 does not change and remains locked.

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 door 142 is kept locked.

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

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

In this embodiment, the processes of steps S11 to S13 described above are performed for all workers entering the restricted area 14. The identification information of all workers who enter the restricted area 14 is then registered in the list 467 as registered ID information. When the operator finishes entering the restricted area 14, for example, the door 142 of the entrance/exit 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. Ru. Thereby, it is possible to prevent workers and the like who are not authorized to enter the restricted area 14. On the other hand, from the perspective of preventing the worker from being trapped inside the restricted area 14, the door 142 may remain open or remain unlocked while the operator is inside the restricted area 14. Good too.

When the worker leaves the restricted area 14 (step S14), the worker unlocks the door 142 using a release switch or the like (not shown) provided near the entrance 141 in the restricted area 14, and exits the restricted area 14. do. Note that if the door 142 remains open or is not locked, the above-mentioned unlocking is not necessary. Next, outside the restricted area 14, the operator operates the touch panel 417 of the safety switch 41 or the changeover switch, etc., thereby inputting an input indicating exit from the restricted area 14. As a result, the control unit 416 starts acquiring entry/exit information indicating the exit of the worker from the restricted area 14 . Subsequently, the worker authentication process shown in FIG. 5 is performed (step S15). The contents of the worker authentication process are the same as those in step S12 described above, and when authentication is successful in the authentication device 6, authentication information is transmitted to the control unit 416 of the safety switch 41.

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

If the authentication device 6 fails to authenticate the read ID information, the ID information deletion unit 463 does not delete the registered ID information from the list 467. As described above, FIG. 4 omits illustration of the process to be performed when authentication in the worker authentication process fails. When each worker exits the restricted area 14, the processes of steps S14 to S16 described above are performed. Therefore, at each point in time, the only workers entering the restricted area 14 are those indicated by the registered ID information included in the list 467.

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

The safety switch 41 may be provided with another notification section instead of the touch panel 417. For example, a plurality of lamps may be provided as the notification unit, and the number of pieces of registered ID information included in the list 467 may be notified to the surroundings by the number of lamps that are turned on. Alternatively, a speaker may be provided as the notification unit, and the number of pieces of registered ID information included in the list 467 or the information specifying 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 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, an open/close state detection unit 465 that detects the open/close state of the door 142 determines that the door 142 is closed.

Next, the lock control unit 466 checks the list 467, and if the list 467 does not include any registered ID information, the lock control unit 466 transmits a lock permission signal to the engagement unit 419 to permit locking of the door 142. be done. Then, the door 142 is locked by the engaging portion 419, making it impossible for the operator to enter the restricted area 14. On the other hand, if the list 467 confirmed by the lock control unit 466 includes one or more pieces of registered ID information, the lock control unit 466 does not transmit a lock permission signal and the door 142 is not locked. This prevents the worker 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 canceling the stopped state of the machine 4 (step S17), for example, the operator requests cancellation of the stopped state of the machine 4 by operating the touch panel 417 of the safety switch 41, etc. input (instructing restart) is made. Subsequently, the cancellation permitting unit 464 checks whether the current list 467 includes registration ID information. Then, if the list 467 does not include any registered ID information (step S18), a permission signal for permitting release of the stopped state of the machine 4 is output to the control device (not shown) of the machine 4 (step S18). S19).

In the control device, an input is made to request release of the stopped state of the machine 4, the permission signal is input, and it is confirmed by reading the door RF tag 418 that the door 142 is closed. If so, operation of the machine 4 is started. Note that operation of the machine 4 is not started simply by closing the door 142 and inserting the actuator 412 into the opening 413. To start operating the machine 4, a permission signal from the release permission section 464 is required. Further, in the above control device, in addition to inputting a permission signal and confirming that the door 142 is closed, the operation of the machine 4 is restarted after confirming that the door 142 is locked by the engaging portion 419. Good too.

The release permission unit 464 sends a permission signal to the control device when it is confirmed that the door 142 is closed by reading the door RF tag 418 in addition to the absence of registered ID information in the list 467. May be output. In addition, the release permission unit 464 outputs a permission signal to the control device when the lock of the door 142 is confirmed in addition to the absence of registered ID information in the list 467 and the closing of the door 142. Good too. Note that in the cancellation permission section 464, when the absence of registered ID information in the list 467 and the closing of the door 142 are confirmed without any input requesting cancellation of the stopped state of the machine 4, The permission signal may be output all the time. In this case, operation of the machine 4 is started when the operator inputs an instruction to restart the machine 4 while the permission signal is being output.

On the other hand, if any registered ID information is included in the list 467 (step S18), the release permission unit 464 does not permit release of the stopped state of the machine 4, and no permission signal is output (step S20). Therefore, the stopped state of the machine 4 is maintained. That is, when the worker remains within the restricted area 14, the machine 4 is prevented from being released from its stopped state. At this time, the display control unit 468 displays on the touch panel 417 that the worker remains in the restricted area 14. All the workers remaining in the restricted area 14 leave the restricted area 14 and the processes of steps S14 to S16 are performed, so that the list 467 no longer includes any registered ID information and the machine 4 is stopped. The state can be canceled (steps S17 to S19).

In step S17, when the worker inputs a request to release the stopped state of the machine 4, a confirmation work may be required to cause the reader 415 to read the worker's RF tag. In this case, the above-described 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's identification information and authority information is sent to the control unit 416. is sent. In the control unit 416, the cancellation permission unit 464 confirms whether the worker has authority to cancel the suspension based on the authentication information. Then, if the worker has the authority to release the stoppage of the machine 4 and the list 467 does not include any registered ID information as described above (step S18), permission is granted to release the stoppage of the machine 4. A signal is output from the release permission section 464 to the control device of the machine 4 (step S19). On the other hand, if the operator does not have the authority to cancel the stoppage of the machine 4, the permission signal is not output.

As explained above, the safety switch 41 is installed outside or inside the restricted area 14 that is surrounded by a fence or wall (i.e., the partition 140) and whose entry is restricted except for the entrance 141 where the door 142 is provided. It will be done. The safety switch 41 is used to release the machine 4 installed in the restricted area 14 from a stopped state. The safety switch 41 includes an ID information acquisition section (ie, reader 415), an ID information registration section 462, an ID information deletion section 463, and a release permission section 464. The reader 415 identifies each worker from the RF tag (i.e., worker RF tag) possessed by each worker by each worker's confirmation operation 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 the identification information of each worker based on the read ID information of each worker when the entry/exit information obtained based on the confirmation operation of each worker indicates trespassing. It is registered in the list 467 as . The entry/exit information is information indicating each worker's entry into the restricted area 14 or exit from 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 allows the machine 4 to be released from the stopped state when the list 467 does not include any registered ID information.

Thereby, release management of the stopped state of the machine 4 placed in the restricted area 14 can be performed with high precision. Specifically, it is possible to prevent the machine 4 from being stopped with high accuracy when a worker is present in the restricted area 14. As a result, 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/close state detection section 465 that detects the open/close state of the door 142 based on information read from the door RF tag 418 provided on the door 142. Thereby, the open/closed state of the door 142 can be detected with high accuracy. Furthermore, when the release permitting 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 account, so that the stopped state of the machine 4 can be released. Management can be performed with even higher precision.

Furthermore, the safety switch 41 reads the identification information indicating the door 142 and detects the open/close state, and mechanically detects that the actuator 412 is inserted into the opening 413 of the switch body 411 to open/close the door 142. Compared to a mechanism that detects the state, opening and closing of the door 142 can be managed with high precision. 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 closure 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. Thereby, the strength of the actuator 412 can be easily increased, and the manufacturing cost of the safety switch 41 can also be reduced.

As mentioned above, reading of 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 worker RF tag and the information stored in the door RF tag 418 readable by the same reader 415. can be converted into

As described above, it is preferable that the safety switch 41 further includes an engaging portion 419 that can lock the door 142. In this way, by making the safety switch 41 also serve as the locking mechanism for the door 142, the structure related to restricting entry to the restricted area 14 can be simplified. Furthermore, safety in the restricted area 14 can be further improved compared to the case where the door 142 is not provided with a locking mechanism.

As mentioned above, the safety switch 41 preferably further includes a lock control section 466. The lock control unit 466 allows the engaging unit 419 to lock the door 142 when the list 467 does not include any registered ID information while the door 142 is unlocked. Thereby, it is possible to prevent the operator from being trapped within the restricted area 14.

As described above, when the door 142 is locked by the engaging portion 419 and the entry/exit information acquired based on the confirmation operation of one worker indicates entry, the lock control section 466 controls the operation It is also preferable to check whether the worker has permission to enter the restricted area based on the read ID information of the worker. In this case, the lock control unit 466 unlocks the door 142 when the operator has access authority, and maintains the lock on the door 142 when the operator does not have access authority. Thereby, it is possible to prevent workers who do not have access authority from entering the restricted area 14, and to manage access to the restricted area 14 with high precision. In addition, if there are multiple restricted areas 14, by individually registering the authority to enter each restricted area 14 for each worker in a database etc., one worker RF tag can be used to access multiple restricted areas 14. access can be controlled individually.

As described above, when a request is made to release the stopped state of the machine 4, one worker performs a confirmation operation, and the release permission unit 464 determines whether the machine 4 is to be released from the stopped state based on the read ID information of the worker. It is preferable to check whether the person has the authority to cancel the suspension. In this case, the cancellation permission unit 464 permits cancellation of the stopped state of the machine 4 if the worker has the authority to cancel the stoppage and the list 467 does not include any registered ID information. Thereby, it is possible to prevent the machine 4 from being released from the stopped state by an operator who does not have the authority to release the stoppage, and to manage the release of the stopped state of the machine 4 with higher precision.

As described above, the safety switch 41 may further include a notification unit (for example, the touch panel 417) that reports the number of pieces of registered ID information included in the list 467 or information specifying the worker indicated by the registered ID information. preferable. Thereby, the presence or absence of a worker within 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 worker authentication processing. I do. A database in which 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. This makes it possible to prevent the database from leaking to the outside. The safety switch 41 does not need to store read ID information either.

Note that 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, the worker's identification information, authority information, etc. may be recorded on the worker RF tag of each worker. As a result, database registration in the safety switch 41 and the authentication device 6 can be omitted, so that the degree of freedom in the operator's authority management can be improved.

Various modifications can be made to the safety switch 41 described above.

For example, in step S11, when an input indicating entry to the restricted area 14 is made, a confirmation work may be required to cause the reader 415 to read the worker's RF tag. In this case, the above-described 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's identification information and authority information is sent to the control unit 416. is sent. Based on the authentication information, the control unit 416 confirms whether the worker has the authority to start inputting entry/exit information. If the worker has the authority to start inputting 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 entry/exit information, the operator will not be able to acquire entry/exit information. The same holds true when an input indicating exit from the restricted area 14 is made in step S14.

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

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

In the above example, it is confirmed whether the worker has permission to enter the restricted area 14 based on the read ID information read from the worker RF tag. If the facility has an RF tag for personal use, the confirmation by the lock control unit 466 of whether or not there is access authority may be omitted.

The locking mechanism for 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, on the side surface opposite to the side surface facing the restricted area 14). In the safety switch 41, the notification section such as the touch panel 417 may be omitted.

The configurations of the above embodiment and each modification may be combined as appropriate unless mutually contradictory.

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

Claims (8)

A safety switch that is installed outside or inside a restricted area that is surrounded by a fence or wall and whose entry is restricted except for entrances and exits equipped with doors, and is used to release the stopped state of machines installed in the restricted area. There it is,
An ID that is obtained as read ID information by reading identification information of each worker from an RF tag owned by each worker by a confirmation operation of each worker before entering the restricted area and after leaving the restricted area. Information acquisition department;
If the entry/exit information indicating entry or exit from the restricted area by each worker obtained based on the confirmation operation of each worker indicates entry, the reading of each worker an ID information registration unit that registers the identification information of each worker in a list as registered ID information based on the ID information;
an ID information deletion unit that deletes registered ID information corresponding to the read ID information of each worker from the list when the entry/exit information acquired based on the confirmation operation of each worker indicates exit; ,
a cancellation permission unit that permits cancellation of the stopped state of the machine when the list does not include any registered ID information;
an open/close state detection unit that detects the open/close state of the door based on information read from a door RF tag provided on the door;
A safety switch characterized by comprising: The safety switch according to claim 1,
A safety switch characterized in that reading of information from the door RF tag is performed by the ID information acquisition section. The safety switch according to claim 1 or 2,
A safety switch further comprising an engaging portion capable of locking the door. 4. The safety switch according to claim 3,
The device may further include a lock control unit that allows the engaging unit to lock the door when the list does not include any registered ID information while the door is unlocked. safety switch. The safety switch according to claim 3 or 4,
When the door is locked by the engaging part and the entry/exit information acquired based on the confirmation operation of one worker indicates entry, A lock control unit that checks whether the worker has permission to enter the restricted area, unlocks the door if the worker has permission to enter, and keeps the door locked if the worker does not have permission to enter. More prepared,
The ID information registration unit registers the identification information of the worker in the list when the worker has the access authority, and does not register the identification information of the worker in the list when the worker does not have the access authority. A safety switch characterized by: A control device that controls the operation of a machine,
The safety switch according to any one of claims 1 to 5 includes a permission signal that allows the release permission section to release the stopped state of the machine, and a signal that the opening/closing state detection section indicates that the door is in the closed state. A control device that starts operation of the machine according to a detection result. A safety switch that is installed outside or inside a restricted area that is surrounded by a fence or wall and whose entry is restricted except for entrances and exits equipped with doors, and is used to release the stopped state of machines installed in the restricted area. There it is,
An ID that is obtained as read ID information by reading identification information of each worker from an RF tag owned by each worker by a confirmation operation of each worker before entering the restricted area and after leaving the restricted area. Information acquisition department;
If the entry/exit information indicating entry or exit from the restricted area by each worker obtained based on the confirmation operation of each worker indicates entry, the reading of each worker an ID information registration unit that registers the identification information of each worker in a list as registered ID information based on the ID information;
an ID information deletion unit that deletes registered ID information corresponding to the read ID information of each worker from the list when the entry/exit information acquired based on the confirmation operation of each worker indicates exit; ,
a cancellation permission unit that permits cancellation of the stopped state of the machine when the list does not include any registered ID information;
Equipped with
When a request is made to release the stopped state of the machine, a confirmation operation is performed by one worker, and the release permission section determines the worker's stop release authority based on the read ID information of the worker. A safety switch that allows the machine to be released from a stopped state if the operator has the authority to release the stoppage and the list does not include any registered ID information. . A safety switch according to any one of claims 1 to 5 and claim 7,
A safety switch further comprising: a notification unit configured to notify the number of pieces of registered ID information included in the list or information specifying a worker indicated by the registered ID information.

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