JP2008191823A - Safety management method, safety management system, and safety control device - Google Patents

Abstract

The present invention secures safety in a hazardous area where a work space of a machine such as a robot and a human work space overlap without reducing productivity.
The first and second light curtains 8 and 9 monitor whether the robot 1 enters the danger area 7 or the worker 6 enters, and only one of the robot 1 or the worker 6 is in danger. When entering the area 7, the safety input from the one light curtain that has detected it is invalidated, and the operation of the robot 1 is continued and the productivity is maintained based on the valid safety input from the other light curtain. On the other hand, when the other of the robot 1 or the worker 6 also enters the dangerous area 7, the driving of the robot 1 is stopped based on the safety input from the other effective light curtain to ensure safety.
[Selection] Figure 1

Description

  The present invention relates to a safety management method, a safety management system, and a safety control device used therefor in a production site where workers and various machines such as machine tools and industrial robots coexist.

Conventionally, various safety systems have been proposed at production sites in order to ensure safety when an operator enters the work area of a machine such as a machine tool or industrial robot. The work area is divided by surrounding a robot or other machine with a safety guard such as a safety fence, and a safety switch is provided at the door of the work area to detect the opening of the door and stop the machine ( For example, refer to Patent Document 1), a sensor that detects that an object has entered the work area and stops the machine.
JP 2004-353849 A

  As described above, every time a worker enters the work area, the safety is ensured by stopping the machine, but the productivity is lowered although safety is ensured.

  For example, as shown in FIG. 9, the work robot 1 performs a required work on the work 2 on the work table 3 installed in the work area surrounded by the safety fence 5, and the work table 3. It is not practical for the worker 6 to stop the robot 1 each time the work 2 is carried in or out of the work table 3 when another work is performed in other work areas.

  The present invention has been made in view of the above-described points, and is a safety management method and safety management in which safety is ensured without compromising productivity and both productivity and safety are achieved. The object is to provide a system and safety control equipment.

 (1) A safety management method according to the present invention is a method for managing safety in a danger area where a work space where a machine works and a work space where a person works overlaps, and monitors at least two operations of the machine or a person. The first and second monitoring boundaries are provided, and the separated safety guard and the first monitoring boundary surround the work space where only the machine operates, while the separated safety guard and the both monitoring boundaries define the dangerous area. The first monitoring boundary is provided between a work space in which only the machine operates and the dangerous area, and one of the monitoring boundaries is set as the monitoring result, and the monitoring result is transmitted to the machine. An invalid monitoring boundary that is not used for controlling the operation of the vehicle, the invalid monitoring boundary can be switched between the first and second monitoring boundaries, and based on the monitoring result of the other valid monitoring boundary, And it controls the operation of 械.

  A machine means various machines, such as a machine tool, a transport machine, a robot, and a construction machine.

  Hazardous area is a dangerous area where machine work and human work may overlap, and a machine disaster may occur. A machine disaster may occur due to machine malfunction or human carelessness. A region is preferred.

  The separation safety guard means a safety guard having a separation function, for example, a fence, a fence, a door, a cover, or the like. This separated safety guard surrounds the working space or dangerous area where only the machine works together with the monitoring boundary, and this separated safety guard may surround the entire circumference of the working space or dangerous area together with the monitoring boundary. However, at least a part of it may be enclosed.

  The monitoring boundary for monitoring the operation refers to a boundary used for monitoring the operation. For example, the boundary used for monitoring various operations such as an operation on the boundary, an operation that crosses the boundary, or an operation that crosses the boundary. Say.

  The first and second monitoring boundaries together with the separation safety guard surround the danger area, and the first monitoring boundary together with the separation safety guard surrounds a working space where only the machine works, It is provided between the work space where only the machine works and the dangerous area, and the operation of the machine is monitored by the first monitoring boundary, and the human operation is monitored by the second monitoring boundary. it can.

  Each monitoring boundary gives, for example, a safe monitoring result that allows the machine to operate when the machine or person is not entering the hazardous area, and the machine or person enters the hazardous area beyond the monitoring boundary. In such a case, it is preferable to give a monitoring result on the dangerous side prohibiting the operation of the machine.

  The number of monitoring boundaries is not limited to two, but three or more may be provided to monitor the operation of a machine or a person.

  Control of machine operation refers to control of start / stop of a machine, control of operation speed, and the like, for example, control of supply / cut-off of power of a machine.

  According to the safety management method of the present invention, the dangerous area is surrounded by the first and second monitoring boundaries and the separated safety guard, and the first monitoring boundary includes the work space in which only a machine works and the dangerous area. So that the machine or person entering the hazardous area can be monitored, and either the machine or the person, for example, a person, crosses the second monitoring boundary, which is one monitoring boundary. Even if a dangerous area is entered, the safety of the first monitoring boundary which is the other effective monitoring boundary can be obtained without stopping the operation of the machine by invalidating the monitoring result on the dangerous side of the second monitoring boundary. On the basis of the monitoring result on the side, the operation of the machine can be continued to continue the work by the machine, and in this state, the machine further exceeds the first monitoring boundary which is the other effective monitoring boundary and is in a dangerous area. Enter the first valid Visual boundary monitoring results, since changes from the safe side in dangerous, on the basis of this change, it is possible such immediately stops the operation of the machine.

  In this way, when either a machine or a person enters the danger area, the monitoring result of one of the monitoring boundaries that detects the entry is invalidated and the operation of the machine is allowed to continue the operation. Furthermore, when the other of the machine or the person enters the dangerous area, the operation of the machine can be stopped and the safety can be ensured based on the monitoring result of the other monitoring boundary that detects the other approach.

  As a result, it is possible to minimize the stoppage of machine operation while ensuring safety in the hazardous area where the work space of the machine and the human work space overlap, and to achieve both safety and productivity. Can do.

  (2) In one embodiment of the safety management method of the present invention, the invalid monitoring boundary may be switched between the first and second monitoring boundaries by a setting operation.

  The setting operation may be an operation of a setting switch or the like, or may be a setting operation by communication.

  According to this embodiment, the first and second monitoring boundaries are the boundaries of the dangerous area. Therefore, when the frequency of manual work in the dangerous area by humans is low, the setting operation may The monitoring boundary to be disabled can be switched between manual operations.

  For example, during normal work, the first monitoring boundary, which is one monitoring boundary for monitoring the operation of the machine, is invalidated by setting operation, and the second monitoring boundary, which is the other effective monitoring boundary for monitoring human motion, is set. Since the operation of the machine can be controlled based on the monitoring result of the above, the operation of the machine can be continued while allowing the machine to operate as long as the person does not enter the danger area beyond the other effective second monitoring boundary. In this state, when a person further enters the dangerous area beyond the effective second monitoring boundary, the monitoring result of the effective second monitoring boundary changes from the safe side to the dangerous side. Based on the change, the operation of the machine can be stopped immediately.

  Further, during manual work, the second monitoring boundary, which is one monitoring boundary for monitoring human movement, is invalidated by setting operation, and the first monitoring boundary, which is the other effective monitoring boundary for monitoring machine operation, is set. The machine operation can be controlled on the basis of the monitoring result of the operator, so that the worker in the dangerous area continues to operate the machine as long as the machine does not enter the dangerous area beyond the other effective first monitoring boundary. However, if the machine enters the danger area beyond the effective first monitoring boundary, the monitoring result of the effective first monitoring boundary changes from the safe side to the dangerous side. Based on this change, the operation of the machine can be stopped immediately.

  (3) In another embodiment of the safety management method of the present invention, the at least two first and second monitoring boundaries monitor the operation of the machine or human and allow the operation of the machine. Alternatively, the monitoring result of the dangerous side prohibiting the operation of the machine is respectively given, and based on the monitoring result of the both monitoring boundaries, either one of the monitoring boundaries is set to the dangerous side. The monitoring result is an invalid monitoring boundary that is not used for controlling the operation of the machine, and the invalid monitoring boundary can be switched between the first and second monitoring boundaries according to the monitoring result of the both monitoring boundaries. The operation of the machine is allowed or prohibited based on the monitoring result of the other valid monitoring boundary and the monitoring result on the safe side of the invalid monitoring boundary.

  According to this embodiment, the first and second monitoring boundaries and the separated safety guard surround the danger area, and the first monitoring boundary is defined between the work space where only the machine works and the danger area. As a result, it is possible to monitor the entry of a machine or person into the hazardous area, and either the machine or person, for example, a person, enters the hazardous area beyond the second monitoring boundary, which is one of the monitoring boundaries. Even if the vehicle enters, the machine does not stop the operation of the machine by invalidating the monitoring result on the dangerous side of the second monitoring boundary, and based on the monitoring result of the first monitoring boundary that is the other effective monitoring boundary. In this state, if the machine attempts to enter the hazardous area beyond the first monitoring boundary, which is the other effective monitoring boundary, the effective first The monitoring result at the monitoring boundary is safe. Changes to dangerous from the basis of this change, it is possible such immediately stops the operation of the machine.

  (4) In the embodiment of the above (3), in the state where the monitoring results of both the monitoring boundaries are on the safe side, the monitoring boundary in which the monitoring result has been changed to the dangerous side first is used as the invalid monitoring boundary. Good.

  According to this embodiment, in a state where the monitoring results of both the first and second monitoring boundaries are both safe, for example, in a state where neither the machine nor the person has entered the hazardous area, the machine or the person For example, when the monitoring result of the second monitoring boundary, which is one of the monitoring boundaries that first enter the dangerous area and monitors it, changes to the dangerous side, the danger of the monitoring boundary If the first monitoring boundary, which is the other effective monitoring boundary, detects that the machine has entered the hazardous area, the effective first monitoring is performed. Depending on the result of the boundary monitoring, the operation of the machine can be stopped immediately.

  (5) In one embodiment of the safety management method of the present invention, the first monitoring boundary monitors an approach operation of the machine to the dangerous area, and prohibits the operation of the machine when there is an entry operation. When there is no approaching operation, a monitoring result on the safe side that allows the operation of the machine is given, and the second monitoring boundary monitors the approaching operation of the human to the dangerous area. When there is an approaching operation, the monitoring result on the dangerous side prohibiting the operation of the machine may be given, and when there is no approaching operation, the monitoring result on the safe side allowing the operation of the machine may be given.

  According to this embodiment, a human enters a dangerous area beyond one of the first and second monitoring boundaries, for example, the second monitoring boundary, and the monitoring result is Even if the monitoring result of the dangerous side prohibiting operation is invalidated, the monitoring result can be invalidated and the operation of the machine can be continued.On the other hand, if the machine enters the danger area beyond the effective first monitoring boundary, The operation of the machine can be immediately stopped based on the monitoring result on the dangerous side of one monitoring boundary.

 (6) A safety management system according to the present invention is a system for managing safety in a danger area where a work space where a machine works and a work space where a person works are overlapped, wherein at least part of the machine and the danger area An operation of the machine based on a safety input provided by the surrounding safety guard, at least two first and second safety devices for monitoring the operation of the machine or human, and the first and second safety devices. The separated safety guard surrounds a work space in which only the machine works, together with a monitoring boundary monitored by the first safety device, while the safety devices that control the two safety devices. The first safety device surrounds the dangerous area together with a monitoring boundary, and the first safety device is located between the working space where only the machine works and the dangerous area. The safety control device is ineffective so that any one of the first and second safety devices is not used for controlling the operation of the machine using the safety input from the safety device. In addition to the safety device, the invalid safety device can be switched between the first and second safety devices.

  The safety device is a device used for monitoring the operation of a machine or a human being, for example, a light curtain, a door switch, a limit switch, a mat switch, or the like. The safety device is preferably capable of monitoring the operation using the monitoring boundary. For example, the operation on the monitoring boundary, the operation exceeding the monitoring boundary, the operation crossing the monitoring boundary, or the monitoring boundary It may be used for monitoring various operations such as crossing operations.

  The first and second safety devices surround the dangerous area by both monitoring boundaries and separate safety guards monitored by the first and second safety devices, respectively, and the first monitoring boundary includes the monitoring boundary and the separated safety guard. , While surrounding the work space in which only the machine works, the monitoring boundary is provided between the work space in which only the machine works and the dangerous area, so the operation of the machine is monitored by the first safety device. However, the human operation can be monitored by the second safety device.

  The safety control device refers to a device that controls start / stop of a machine and control of an operation speed, for example, supply / cut-off of power of the machine, based on a safety input given from the safety device.

  According to the safety management system of the present invention, the first or second safety device monitors the entry of a machine or a person into the danger area, and either a machine or a person, for example, a person enters the danger area. However, the safety input from the second monitoring boundary, which is one safety device that monitors human movement, is invalidated and the operation from the first safety device, which is the other effective safety device, is stopped without stopping the operation of the machine. Based on the safety input, the operation of the machine can be continued by allowing the machine to operate, and in this state, when the machine enters the hazardous area, based on the safety input from the first local safety device that is valid. It becomes possible to immediately stop the operation of the machine.

  As a result, it is possible to minimize the stoppage of machine operation while ensuring safety in the hazardous area where the work space of the machine and the human work space overlap, and to achieve both safety and productivity. Can do.

  (7) In one embodiment of the safety management system of the present invention, the safety control device switches the invalid safety device between the first and second safety devices according to a switching setting.

  According to this embodiment, the first or second safety device monitors the entry of a machine or a person into the dangerous area, and when the frequency of manual work in the dangerous area by a human is low, The safety device that disables the safety input can be switched by the switching setting during manual operation.

  During normal operation, the switching setting disables the safety input from the first safety device that is one safety device that monitors the operation of the machine, and the second effective safety device that monitors the human operation is the second safety device. Since the machine operation can be controlled based on the safety input from the safety device, the machine can continue to operate while allowing the machine to operate as long as the person does not enter the danger area, while the person enters the danger area. Then, the operation of the machine can be immediately stopped based on the safety input from the second safety device that is the other effective safety device.

  Also, during manual work, the switching setting makes the safety input from the second safety device, which is one safety device that monitors human movement, invalid, and the second safety device that is the other effective safety device that monitors the machine operation. Since the operation of the machine can be controlled based on the safety input from the safety device 1, the operator can manually operate in the dangerous area while continuing to operate the machine unless the machine enters the dangerous area. On the other hand, when the machine enters the danger area, the operation of the machine can be immediately stopped based on the safety input from the first safety device that is the other effective safety device.

  (8) In another embodiment of the safety management system of the present invention, the safety control device controls the permission or prohibition of the operation of the machine based on safety inputs given from the first and second safety devices. The safety input is a safety side safety input that permits operation of the machine or a danger side that prohibits operation of the machine, and the safety control device includes the first and second safety devices. Based on the safety input from the one of the two safety devices, the dangerous safety input from the safety device is an invalid safety device that does not use to control the operation of the machine, In accordance with the safety input of both safety devices, the safety device to be invalidated is switched between the safety devices.

  According to this embodiment, the first or second safety device monitors the entry of a machine or a person into the danger area, and even if either a machine or a person, for example, a person enters the danger area, Safety input from the first safety device, which is the other effective safety device, without stopping the operation of the machine by disabling the safety input from the second safety device, which is one safety device that monitors human movements In this state, when the machine enters the hazardous area, the safety input from the first safety device, which is an effective other safety device, is allowed. Based on this, it becomes possible to immediately stop the operation of the machine.

  (9) In the embodiment of the above (8), the safety control device is configured such that the safety input is first on the dangerous side in a state where both the safety inputs from the first and second safety devices are on the safe side. The changed safety device may be the invalid safety device.

  According to this embodiment, in a state where safety inputs from both the first and second safety devices are both safe, for example, in a state where neither a machine nor a person has entered the danger area, When the safety input of the second safety device, which is one of the safety devices that one of the humans first enters the dangerous area and monitors it, changes to the dangerous side, the safety device's The dangerous safety input is disabled and the machine continues to operate. When the safety input from the first safety device, which is the other active safety device, is detected, the other side of the machine is detected. The operation of the machine can be immediately stopped by a safety input from the first safety device which is a safety device.

  (10) In one embodiment of the safety management system of the present invention, the first safety device monitors an approach operation of the machine to the dangerous area, and when the approach operation is detected, When the approaching operation is not detected, a safety-side safety input that permits the operation of the machine is given to the safety control device, and the second safety device When the approaching operation to the dangerous area is monitored and the approaching operation is detected, a safety input on the dangerous side for prohibiting the operation of the machine is provided. When the approaching operation is not detected, the safety input allowing the operation of the machine is performed. Side safety inputs may be provided to the safety control devices.

  According to this embodiment, one of the first safety device and the second safety device, for example, a person enters the danger area, and the safety input from the second safety device prohibits the operation of the machine. Even if the safety input becomes dangerous, the safety input can be disabled and the operation of the machine can be continued. On the other hand, when the machine enters the danger area, the machine is operated based on the safety input from the valid first safety device. Can be stopped immediately.

  (11) The safety control device of the present invention is a safety control device that controls the operation of a machine based on a safety input given from the safety device, and is at least two first, first, monitors the operation of the machine or a human being. A safety input from a second safety device is provided, and the two safety devices have a working space in which the machine works and a working space in which the human works by a monitoring boundary and a separate safety guard that are monitored by each safety device. The first safety device surrounds a working space in which only the machine works by the monitoring boundary and the separation safety guard, and the monitoring boundary is It is arranged so as to be located between the work space where only the machine works and the dangerous area, and either one of the first and second safety devices is connected to the safety device. With the invalid safety devices without using the safety input from the device to the control of operation of the machine, the invalid safety devices, the first, is switchable second safety device.

  The first and second safety devices surround the dangerous area by both monitoring boundaries and separate safety guards monitored by the first and second safety devices, respectively, and the first monitoring boundary includes the monitoring boundary and the separated safety guard. , While surrounding the work space in which only the machine works, the monitoring boundary is provided between the work space in which only the machine works and the dangerous area, so the operation of the machine is monitored by the first safety device. However, the human operation can be monitored by the second safety device.

  According to the safety control device of the present invention, the first or second safety device monitors the entry of a machine or a person into the danger area, and either a machine or a person, for example, a person enters the danger area. However, the safety input from the second safety device, which is one safety device that monitors human movement, is invalidated and the operation from the first safety device, which is the other valid safety device, is stopped without stopping the operation of the machine. Based on the safety input, the operation of the machine can be continued by allowing the machine to operate, and in this state, when the machine enters the hazardous area, the safety from the first safety device which is an effective local safety device is obtained. Based on the input, it becomes possible to immediately stop the operation of the machine.

 (12) In one embodiment of the safety control device of the present invention, the invalid safety device is switched between the first and second safety devices according to the switching setting.

  According to this embodiment, the first or second safety device monitors the entry of a machine or a person into the dangerous area, and when the frequency of manual work in the dangerous area by a human is low, The safety device that disables the safety input can be switched by the switching setting during manual operation.

  Therefore, during normal work, the switching setting disables the safety input from the first safety device that is one safety device that monitors the operation of the machine, and the other effective safety device that monitors the human operation. Since the operation of the machine can be controlled based on the safety input from the safety device 2, the machine can be allowed to continue to operate as long as the person does not enter the danger area. Upon entering, the operation of the machine can be immediately stopped based on the safety input from the second safety device which is the other effective safety device.

  Also, during manual work, the switching setting makes the safety input from the second safety device, which is one safety device that monitors human movement, invalid, and the second safety device that is the other effective safety device that monitors the machine operation. Since the operation of the machine can be controlled based on the safety input from the safety device 1, the operator can manually operate in the dangerous area while continuing to operate the machine unless the machine enters the dangerous area. On the other hand, when the machine enters the danger area, the operation of the machine can be immediately stopped based on the safety input from the first safety device that is the other effective safety device.

 (13) In another embodiment of the safety control device according to the present invention, the permission or prohibition of the operation of the machine is controlled based on safety inputs from the at least two first and second safety devices. The safety input is a safety input that permits the operation of the machine or a danger that prohibits the operation of the machine. Both safety inputs are based on the safety inputs of the first and second safety devices. Either one of the safety devices is an invalid safety device that does not use the dangerous-side safety input from the safety device to control the operation of the machine, and the safety input according to both safety devices. The safety device to be invalidated is switched between the safety devices.

  According to this embodiment, the first or second safety device monitors the entry of a machine or a person into the danger area, and even if either a machine or a person, for example, a person enters the danger area, Safety input from the first safety device, which is the other effective safety device, without stopping the operation of the machine by disabling the safety input from the second safety device, which is one safety device that monitors human movements In this state, when the machine enters the hazardous area, the safety input from the first safety device, which is an effective other safety device, is allowed. Based on this, it becomes possible to immediately stop the operation of the machine.

  (14) In the embodiment of (13) above, in a state where the safety inputs from the first and second safety devices are both on the safe side, the safety device whose safety input has been changed to the dangerous side first is The invalid safety device may be used.

  According to this embodiment, in a state where safety inputs from both the first and second safety devices are both safe, for example, in a state where neither a machine nor a person has entered the danger area, When the safety input of the second safety device, which is one of the safety devices that one of the humans first enters the dangerous area and monitors it, changes to the dangerous side, the safety device's The dangerous safety input is disabled and the machine continues to operate. When the safety input from the first safety device, which is the other active safety device, is detected, the other side of the machine is detected. The operation of the machine can be immediately stopped by a safety input from the first safety device which is a safety device.

  (15) In one embodiment of the safety control device of the present invention, the first safety device monitors an approach operation to a dangerous area where a work space of the machine and a human work space overlap, Is detected, a dangerous safety input for prohibiting the operation of the machine is provided, and a safety input for permitting the operation of the machine is provided when no approaching operation is detected. Monitors the human approaching action to the dangerous area, and when the approaching action is detected, the safety input on the dangerous side prohibiting the operation of the machine, and when the approaching action is not detected, the machine operation It is also possible to give a safety input on the safe side that allows

  According to this embodiment, one of the first safety device and the second safety device, for example, a person enters the danger area, and the safety input from the second safety device prohibits the operation of the machine. Even if the safety input becomes dangerous, the safety input can be invalidated and the operation of the machine can be continued. On the other hand, if the machine tries to enter the dangerous area, the safety input based on the valid first safety device is used. The machine operation can be stopped immediately.

  (16) In another embodiment of the safety control device of the present invention, a safety output is given to a safety output control object according to a program based on a safety input from the safety device, and the operation of the machine is controlled. Then, a semiconductor output may be given as the safety output.

  The safety output control target refers to a target controlled by a safety output that is an output of the safety control device, for example, a magnet contactor, a motor controller, a variable motor, a PLC, or the like.

  According to this embodiment, since a safety output that is a semiconductor output is given to a safety output control object according to a program based on a safety input from a safety device, a safety circuit is provided by a relay sequence like a relay unit incorporating an electromagnetic relay. It is possible to reduce the number of wires and to easily cope with the change of the software on the maker side according to the user's request by changing the software. Become.

  (17) In the embodiment of the above (16), an input for logical connection is given from another safety control device, and a logical operation is performed between the input for logical connection and the safety input, and the safety output control target is set as the target. A safety output may be given.

  The logical connection input refers to an input given from another safety control device in order to connect the safety control device to another safety control device in association with a logic such as logical product or logical sum.

  According to this embodiment, the safety control device and other safety control devices can be associated by logic such as logical product or logical sum.

  According to the present invention, while ensuring safety in a dangerous area where a work space where a machine works and a work space where a human works overlaps, the stoppage of operation of the machine is reduced as much as possible, and safety and productivity are improved. Can be made compatible.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing an overview of the arrangement of a safety management system according to an embodiment of the present invention.
In this system, the work robot 1 and the work table 3 on which the work 2 is placed are surrounded by a safety fence 5 which is a separation safety guard except for an opening 4 for loading and unloading the work 2. ing.

  The worker 6 loads and places the work 2 on the work table 3 from the opening 4, the robot 1 performs a required work on the work 2, and the work 2 that has finished the work 2 is opened by the worker 6. Then, the work 2 is replaced with the next work 2 and the work 2 is sequentially performed.

  The robot 1 performs work using the surrounding space and the space on the work table 3, and the worker 6 carries the work 2 into or out of the work table 3 with the upper body from the opening 4. The surrounding space including the work table 3 is a dangerous area 7 where the work space where the robot 1 works and the work space where the worker 6 works overlap.

  In this embodiment, in order to ensure the safety of the worker 6, first and second light curtains 8 and 9 composed of photoelectric sensors as safety equipment and an emergency stop switch 10 as safety equipment are provided. .

  The first and second light curtains 8 and 9 are arranged so as to sandwich the work table 3 arranged in the dangerous area 7, and the first light curtain 8 performs an approach operation of the robot 1 to the dangerous area 7. The second light curtain 9 monitors the approaching action of the worker 6 to the dangerous area 7.

  Each of the light curtains 8 and 9 is provided with projectors 8a and 9a in which a plurality of light projecting elements are arranged in the vertical direction on one side, and a plurality of light receiving elements on the opposite side so as to correspond to the light projecting elements. The arranged light receivers 8b and 9b are arranged, the first light curtain 8 detects the approaching operation of the arm 1a of the robot 1 to the dangerous area 7, and the second light curtain 9 An approaching action to the dangerous area 7 of the upper body of the worker 6 is detected.

  The danger area 7 is surrounded by the monitoring fence where both the light curtains 8 and 9 monitor the approaching operation and the safety fence 5. In addition, the work space where only the robot works is surrounded by the monitoring boundary where the first light curtain 8 monitors the approaching operation and the safety fence 5 around the robot 1.

  FIG. 2 is a schematic diagram showing the overall configuration of the system of FIG. 1, and parts corresponding to those in FIG.

  In this embodiment, the first safety unit 11 as a safety control device to which the emergency stop switch 10 is connected and the first safety unit 11 are connected, and the first and second light curtains 8 and 9 are connected. Is connected to the second safety unit 12 as a safety control device.

  The emergency stop switch 10 gives a dangerous safety input for prohibiting the driving of the robot 1 to the first safety unit 11 by the operation of the operator 6 in an emergency. Gives a safe side safety input that is allowed to drive.

  When the light between the light projecting and receiving devices 8a and 8b; 9a and 9b is blocked by the robot 1 or the operator 6 entering the danger area 7 shown in FIG. 12 is given a danger-side safety input prohibiting the driving of the robot 1, and the robot 1 or the operator 6 has not entered the dangerous area 7, and the light between the light emitters / receivers 8a, 8b; 9a, 9b Is not shielded from light, a safety-side safety input that allows driving of the robot 1 is given.

  Each safety unit 11, 12 is equipped with a microcomputer, and based on safety inputs from safety devices such as emergency stop switches, light curtains, door switches, etc., the safety of magnet contactors, motor controllers, variable motors, etc. according to programs A safety output, which is a semiconductor output (transistor output), is given to an output target to control the operation of a machine such as a robot.

  Each safety unit 11, 12 can provide a semiconductor output in the same output state as the safety output as a logical connection input to the subsequent safety unit.

  The logical connection input is an input for associating a subsequent-stage safety unit to which the logical connection input is provided with a previous-stage safety unit to which the logical connection input is provided by logic such as logical product.

  In this embodiment, the first safety unit 11 provides a logical connection input to the second safety unit 12 at the subsequent stage based on the safety input from the emergency stop switch 10. When a safety-side safety input that allows driving of the robot 1 is given from the emergency stop switch 10, the first safety unit 11 also gives a safety-side logical connection input to the second safety unit 12. When the emergency stop switch 10 is operated and a dangerous side safety input for prohibiting the driving of the robot 1 is given from the emergency stop switch 10, the dangerous side logical connection input is also given to the second safety unit 12. .

  The second safety unit 12 is given a safety input from the first and second light curtains 8 and 9 and a logical connection input from the first safety unit 11, while being supplied to the motor 13 that drives the robot 1. A safety output for the first and second magnet contactors 14 and 15 for supplying / cutting off electric power and an operation command for the motor controller 16 are output to control the operation of the robot 1.

  Here, the characteristic operation of the second safety unit 12 will be described. In order to facilitate understanding, the emergency stop switch 10 is operated normally, that is, from the first safety unit 11 to the safety side. It is assumed that the input for logical connection is given.

  In this embodiment, the second safety unit 12 has one of the light curtains based on safety inputs from the first and second light curtains 8 and 9 in order to achieve both productivity and safety. The safety input from the dangerous side is invalidated, and safety is ensured based on the safety input from the other valid light curtain and the safety input from the invalid light curtain.

  The light curtain to be invalidated is a state where the robot 1 and the worker 6 have not entered the dangerous area 7, that is, the dangerous area 7 of the robot 1 or the worker 6 by the first and second light curtains 8 and 9. No entry has been detected, and in either case the safety input is given to the safe side (ON), the entry to the dangerous area 7 was detected first and the safety input changed to the dangerous side (OFF). It is a light curtain.

  In FIG. 1, when neither the robot 1 nor the worker 6 has entered the dangerous area 7, both the first and second light curtains 8 and 9 detect the entering operation of the dangerous area 7. In both cases, the safety input of the safety side (ON) is given to the second safety unit 12, and the operation of the robot 1 is allowed.

  In this state, for example, when the robot 1 first enters the dangerous area 7 and is detected by the first light curtain 8, the safety input from the first light curtain 8 on the dangerous side (OFF) is given. Although given, the dangerous side (OFF) safety input is invalidated, and the second safety unit 12 continues to output the safety side (ON) safety output that allows the robot 1 to be driven.

  When only the robot 1 is entering the dangerous area 7, the safety input from the second light curtain 9 is effective. Therefore, in this state, the operator 6 enters the dangerous area 7 for the second time. When the safety input of the dangerous side (OFF) detected by the light curtain 9 is given to the second safety unit 12, the second safety unit 12 moves to the dangerous side (OFF) that prohibits the driving of the robot 1. While outputting the safety output, the output of the operation command is stopped, whereby the contact of the first and second magnet contactors 14 and 15 is turned off to cut off the power supply to the motor 13 that drives the robot 1. Then, the robot 1 is stopped and the safety of the worker 6 is ensured.

  Similarly, in a state where neither the robot 1 nor the worker 6 has entered the dangerous area 7, the worker 6 first enters the dangerous area 7 and is detected by the second light curtain 9. The safety input on the dangerous side (OFF) from the second light curtain 9 is invalidated, and the second safety unit 12 outputs a safety side (ON) safety output that allows the robot 1 to be driven. to continue.

  In a state where only the worker 6 has entered the dangerous area 7, the safety input from the first light curtain 8 is effective. Therefore, in this state, the robot 1 has entered the dangerous area 7 for the first time. When the safety input of the dangerous side (OFF) detected by the light curtain 8 is given to the second safety unit 12, the second safety unit 12 is on the dangerous side (OFF) that prohibits the driving of the robot 1. While outputting the safety output, the output of the operation command is stopped, whereby the contact of the first and second magnet contactors 14 and 15 is turned off to cut off the power supply to the motor 13 that drives the robot 1. Then, the robot 1 is stopped and the safety of the worker 6 is ensured.

  In this embodiment, when one light curtain is invalidated, a display output for turning on an unillustrated indicator lamp is provided so that the operator 6 can recognize the invalid light curtain. Yes.

  The above is a normal operation in which the emergency stop switch 10 is not operated. In an emergency, when the emergency stop switch 10 is operated and a dangerous side (OFF) safety input is given to the first safety unit 11. The logical connection input to the second safety unit 12 is in a dangerous side (OFF) state for prohibiting the driving of the robot, and the second safety unit 12 is connected to this dangerous side (OFF) logical connection input; The logical product with its own safety output is obtained, a safety output on the dangerous side (OFF) is output, the contacts of the first and second magnet contactors 14 and 15 are turned off, and the motor 13 that drives the robot 1 is supplied. The robot 1 is stopped by shutting off the power supply, thereby ensuring the safety of the worker 6 in an emergency.

  In this way, when only one of the robot 1 or the worker 6 has entered the danger area 7, the safety-side safety input from one light curtain that detects the entry is invalidated, and the robot 1 While the operation by the robot 1 is continued while allowing the operation, if the other of the robot 1 or the worker 6 enters the dangerous area from this state, the dangerous side from the other effective light curtain for detecting the entry On the basis of the safety input, the operation of the robot 1 is stopped to ensure safety.

  As a result, it is possible to minimize the stoppage of the operation of the robot 1 while ensuring the safety in the danger area 7 where the work space of the robot 1 and the work space of the worker 6 overlap each other. And both.

  FIG. 3 is a logic circuit diagram for explaining the operation of the second safety unit 12 described above, and Table 1 is a truth table.

表１では、第１のセーフティユニット１１からの論理接続用入力が安全側（ＯＮ）である場合を示している。

Table 1 shows a case where the logical connection input from the first safety unit 11 is on the safe side (ON).

  As shown in FIG. 3, the first and second safety inputs from the first and second light curtains 8 and 9 are input to the OR circuit 17 and the first and second ANDs for each display output. The signals are input to the circuits 18 and 19, respectively. Each of the AND circuits 18 and 19 receives a logical connection input from the first safety unit 11.

  The logical connection input from the first safety unit 11 and the output of the OR circuit 17 are input to the third AND circuit 20, and the output of the third AND circuit 20 is the safety of the second safety unit 12. Output and output for logical connection to the safety unit in the subsequent stage.

  As shown in Table 1, neither the robot 1 nor the worker 6 has entered the dangerous area 7, and the first and second safety inputs from the first and second light curtains 8 and 9 are both When it is on the safe side (ON), the safety output of the second safety unit 12 is on the safe side (ON), and the drive of the robot 1 is allowed.

  In this state, when the operator 6 first enters the danger area 7, the second safety input from the second light curtain 9 becomes the danger side (OFF), and the danger side of the second light curtain 9. Since the safety input of (OFF) is invalidated, the safety output of the second safety unit 12 remains on the safe side (ON), and the driving of the robot 1 is continued.

  In a state where the second light curtain 9 is invalidated, only the second display output corresponding to the second light curtain 9 is turned on and the second indicator lamp is lit, and the worker 6 It can be recognized that the light curtain 9 is disabled.

  If only the robot 1 enters the danger area 7 and the operator 6 tries to enter the danger area 7, the first safety input from the first light curtain 8 is the danger side (OFF Since the safety input of the first light curtain 8 is valid, the safety output of the second safety unit 12 is on the danger side (OFF), and the driving of the robot 1 is stopped to ensure safety. Will be.

  Similarly, when neither the robot 1 nor the worker 6 has entered the dangerous area 7 and the worker 6 enters first, the first safety input from the first light curtain 8 is the dangerous side ( Since the safety input on the danger side (OFF) of the first light curtain 8 is invalidated, the safety output of the second safety unit 12 remains on the safety side (ON), and the robot The driving of 1 is continued.

  In a state where the first light curtain 8 is invalidated, only the first display output corresponding to the first light curtain 8 is turned on and the first indicator lamp is turned on. It can be recognized that the light curtain 8 is disabled.

  When only the operator 6 enters the danger area 7 and the robot 1 enters the danger area 7, the second safety input from the second light curtain 9 becomes the danger side (OFF). Since the safety input of the second light curtain 9 is valid, the safety output of the second safety unit 12 is on the danger side (OFF), and the driving of the robot 1 is stopped to ensure safety. become.

  FIG. 4 is a diagram for explaining a connection state of the second safety unit 12.

  In this embodiment, the light receiving devices 8b and 9b of the light curtains 8 and 9 are connected to the safety input terminals T11 and T22 and the terminals T62 and T72 of the second safety unit 12, respectively, and the terminals for instantaneous safety output. The above-described first and second magnet contactors 14, 15 and the like are connected to S14, S24 and off-delay safety output terminals S44, S54, and the light curtain disabled to display output terminals UA, UB. Are connected to the first and second indicator lamps 23 and 24.

  The second safety unit 12 includes a logical connection input terminal T41 and an output terminal L1, and also includes an auto / manual reset terminal.

  Further, the second safety unit 12 is provided with a dip switch 21 for enabling or disabling the logical connection, and also provided with a dip switch 22 for mode switching of the second embodiment to be described later.

(Embodiment 2)
FIG. 5 is a diagram showing an outline of the arrangement of a safety management system according to another embodiment of the present invention, and FIG. 6 is a schematic diagram showing the overall configuration of the system of FIG. Corresponding parts bear the same reference symbols.

  The above-described embodiment is suitable for the worker 6 to frequently enter the dangerous area 7 and perform the work of exchanging the workpiece 2 or the like. On the other hand, this embodiment is suitable when the frequency of the operator entering the dangerous area 7 is relatively low.

  In this embodiment, a door 25 and a door switch 26 are installed in place of the second light curtain 9 of the above-described embodiment in order to monitor the approaching action of the worker 6 to the dangerous area 7. In the state where the door 25 is closed, the switch 26 gives a safety-side (ON) safety input that allows the robot to be driven to the second safety unit 12, while the door 25 is opened and the operator 6 When entering the dangerous area 7, a safety input on the dangerous side (OFF) that prohibits the driving of the robot 1 is given to the second safety unit 12.

  In the above-described embodiment, the second safety unit 12 invalidates the safety input from one of the light curtains based on the safety input from both the light curtains 8 and 9. A changeover switch 27 is provided, and when the normal operation mode is selected by switching operation of the mode changeover switch 27, the safety input from the light curtain 8 that monitors the robot 1 entering the dangerous area 7 is invalidated, and the operator 6 However, when the manual operation mode for entering the dangerous area 7 and performing maintenance or the like is selected, the safety input from the door switch 26 is invalidated.

  When the operator 6 operates the mode changeover switch 27 to select the normal work mode, the safety input from the light curtain 8 is invalidated, so that the robot 1 enters the danger area 7 and the safety from the light curtain 8. Even if the input becomes a safety input on the dangerous side (OFF), the second safety unit 12 ignores the safety input on the dangerous side and allows the robot 1 to be driven.

  In this normal work mode, the safety input from the door switch 26 is valid. Therefore, for example, when the robot 1 is operating, the worker 6 opens the door 25 and enters the danger area 7. Then, the opening of the door 25 is detected by the door switch 26, and a safety input on the dangerous side (OFF) is given to the second safety unit 12, whereby the second safety unit 12 1 outputs a safety output on the danger side (OFF) prohibiting the driving of 1 and stops the output of the operation command, thereby turning off the contacts of the first and second magnetic contactors 14 and 15 to The supply of power to the motor 13 to be driven is cut off, the robot 1 is stopped, and the safety of the worker 6 is ensured.

  Further, when the operator 6 switches the mode changeover switch 27 and selects the manual operation mode, the safety input from the door switch 26 is invalidated. Even if a safety input on the danger side (OFF) is given from the door switch 26, the second safety unit 12 ignores the safety input on the danger side, and unless the robot 1 is in the danger area 7, The driving of the robot 1 is allowed.

  In this manual operation mode, the safety input from the light curtain 8 is valid. Therefore, for example, when the operator 6 enters the danger area 7, the robot 1 enters the danger area 7. Then, the light curtain 8 detects the approach of the robot 1 and the safety input on the dangerous side (OFF) is given to the second safety controller 12, and the second safety unit 12 prohibits the driving of the robot 1. The safety output of the dangerous side (OFF) to be output is output, and the output of the operation command is stopped, whereby the contact of the first and second magnet contactors 14 and 15 is turned off to the motor 13 that drives the robot 1. The robot 1 is stopped by shutting off the supply of power to ensure the safety of the worker 6.

  Also in this embodiment, when the light curtain 8 or the door switch 26 is disabled, the corresponding indicator lamp is turned on so that the operator can recognize the disabled light curtain 8 or the door switch 26. Display output is given.

  The above is a normal operation in which the emergency stop switch 10 is not operated. In an emergency, when the emergency stop switch 10 is operated and a dangerous side (OFF) safety input is given to the first safety unit 11. The logical connection input to the second safety unit 12 is in a dangerous side (OFF) state for prohibiting the driving of the robot, and the second safety unit 12 is connected to this dangerous side (OFF) logical connection input; The logical product with its own safety output is obtained, a safety output on the dangerous side (OFF) is output, the contacts of the first and second magnet contactors 14 and 15 are turned off, and the motor 13 that drives the robot 1 is supplied. The robot 1 is stopped by shutting off the power supply, thereby ensuring the safety of the worker 6 in an emergency.

  FIG. 7 is a logic circuit diagram for explaining the operation of the second safety unit 12, and Tables 2 and 3 are truth tables of the normal work mode and the manual work mode.

表２，表３では、第１のセーフティユニット１１からの論理接続用出力（論理入力）が安全側（ＯＮ）である場合を示している。

Tables 2 and 3 show the case where the logical connection output (logical input) from the first safety unit 11 is on the safe side (ON).

  As shown in FIG. 7, the first safety input from the light curtain 8 and the second safety input from the door switch 26 are input to the first and second AND circuits 28 and 29, respectively, and the first AND The output of the mode switch 27 is input to the circuit 28, and the output of the mode switch 27 is input to the second AND circuit 29 via the inverter 30.

  The outputs of the first and second AND circuits 28 and 29 are input to the OR circuit 31 and also input to the third and fourth AND circuits 32 and 33 for display output. The third and fourth AND circuits 32 and 33 receive the logical connection output (logic input) from the first safety unit 11, respectively.

  Further, the logical connection input from the first safety unit 11 and the output of the OR circuit 31 are input to the fifth AND circuit 34, and the output of the fifth AND circuit 34 is input to the second safety unit 12. This is a safety connection output and a logical connection output to the safety unit in the subsequent stage.

  When the normal operation mode is selected by the mode changeover switch 27, the first safety input from the light curtain 8 is invalidated and, as shown in Table 2, the safety side (ON) from the door switch 26 or In response to the second safety input on the dangerous side (OFF), the safety output of the second safety unit 12 becomes the safe side (ON) or the dangerous side (OFF). Further, only the first display output corresponding to the disabled light curtain 8 is turned ON and only the first indicator lamp is lit, so that the operator knows that the light curtain 8 is disabled. be able to.

  When the manual operation mode is selected by the mode switch 27, the second safety input from the door switch 26 is invalidated, and as shown in Table 3, the safety side (ON) from the light curtain 8 or In response to the first safety input on the dangerous side (OFF), the safety output of the second safety unit 12 becomes the safe side (ON) or the dangerous side (OFF). Further, only the second display output corresponding to the disabled door switch 26 is turned ON and the second indicator lamp is lit, and the operator 6 grasps that the door switch 26 is disabled. be able to.

  FIG. 8 is a diagram for explaining the connection state of the second safety unit 12 of this embodiment, and parts corresponding to the above-described embodiment are denoted by the same reference numerals.

  In this embodiment, a door switch 26 is connected to the safety input terminals T61, T62; T71, T72 of the second safety unit 12 instead of the light curtain 9, and further to the terminals M1, M2. Is connected to the mode switch 27.

(Other embodiments)
In each of the embodiments described above, a machine or human approaching operation to a dangerous area is monitored. However, the present invention is not limited to such an operation, and for example, a high-speed transfer operation in a dangerous area by a transfer machine such as a conveyor can be performed. It can also be applied to applications such as monitoring and ensuring safety by slowing down or stopping the transport operation when a person enters the danger zone during a high-speed transport operation.

  In each of the above-described embodiments, the entry into the dangerous area is monitored by the light curtain or the door switch. However, the mat switch may be installed in the dangerous area including the monitoring boundary to monitor the entry into the dangerous area. .

  In each of the above-described embodiments, even if a safety unit equipped with a microcomputer that provides a semiconductor output is used as a safety control device, as another embodiment of the present invention, a relay unit including an electromagnetic relay is used to perform a relay sequence. A safety circuit may be configured.

  The present invention is useful for safety management at a production site where machines and workers coexist.

It is a figure which shows the outline | summary of arrangement | positioning of the safety management system which concerns on embodiment of this invention. It is the schematic which shows the whole structure of the system of FIG. It is a logic circuit diagram with which it uses for description of operation | movement of the 2nd safety unit of FIG. It is a figure which shows the connection state of the 2nd safety unit of FIG. It is a figure corresponding to FIG. 1 of other embodiment of this invention. It is the schematic which shows the whole structure of the system of FIG. FIG. 7 is a logic circuit diagram for explaining the operation of the second safety unit in FIG. 6. It is a figure which shows the connection state of the 2nd safety unit of FIG. It is a figure for demonstrating the conventional subject.

Explanation of symbols

1 Robot (machine)
5 Safety fence 7 Hazardous area 8, 9 1st and 2nd light curtain (safety equipment)
10 Emergency stop switch 11, 12 First and second safety unit (safety control equipment)
14, 15 First and second magnet contactors 26 Door switch (safety device)
27 Mode selector switch

Claims (17)

A method for managing safety in a hazardous area where a work space where machines work and a work space where humans work overlaps,
Providing at least two first and second monitoring boundaries for monitoring the operation of the machine or human;
A separation safety guard and the first monitoring boundary surround the work space where only the machine works, while a separation safety guard and the both monitoring boundaries surround the danger area,
The first monitoring boundary is provided between a work space in which only the machine works and the dangerous area;
Any one of the two monitoring boundaries is set as an invalid monitoring boundary whose monitoring result is not used for controlling the operation of the machine,
The invalid monitoring boundary can be switched between the first and second monitoring boundaries,
A safety management method, comprising: controlling operation of the machine based on a monitoring result of another effective monitoring boundary.   The safety management method according to claim 1, wherein the invalid monitoring boundary is switched between the first and second monitoring boundaries by a setting operation. The at least two first and second monitoring boundaries monitor the operation of the machine or a human to give a monitoring result of a safe side that allows the operation of the machine or a dangerous side that prohibits the operation of the machine, respectively. Is,
Based on the monitoring results of the two monitoring boundaries, the monitoring boundary of either one of the two monitoring boundaries is set as an invalid monitoring boundary that does not use the monitoring result on the dangerous side for controlling the operation of the machine,
The invalid monitoring boundary can be switched between the first and second monitoring boundaries according to the monitoring results of the both monitoring boundaries,
The safety management method according to claim 1, wherein operation of the machine is permitted or prohibited based on a monitoring result of the other valid monitoring boundary and a monitoring result on the safety side of the invalid monitoring boundary.   The safety management method according to claim 3, wherein in a state where the monitoring results of both the monitoring boundaries are on the safe side, a monitoring boundary in which the monitoring result has changed to the dangerous side first is set as the invalid monitoring boundary. The first monitoring boundary monitors the approaching operation of the machine to the dangerous area. When there is an approaching operation, the monitoring result of the dangerous side prohibiting the operation of the machine is obtained. Give the monitoring results on the safe side that allow operation,
The second monitoring boundary monitors a person's entry operation into the dangerous area. When there is an entry operation, the monitoring result on the dangerous side prohibiting the operation of the machine is displayed. When there is no entry operation, the operation of the machine is performed. The safety management method according to any one of claims 1 to 4, wherein a safety-side monitoring result that permits the control is provided. A system for managing safety in a hazardous area where a work space where machines work and a work space where humans work overlap,
A separate safety guard surrounding at least a portion of the machine and the hazardous area;
At least two first and second safety devices for monitoring the operation of the machine or human;
A safety control device for controlling the operation of the machine based on safety inputs given from the first and second safety devices;
The separated safety guard surrounds a work space where only the machine works together with a monitoring boundary monitored by the first safety device, and surrounds the dangerous area together with both monitoring boundaries monitored by the safety devices. And
The first safety device is arranged such that a monitoring boundary thereof is located between a work space where only the machine works and the dangerous area,
In the safety control device, any one of the first and second safety devices is an invalid safety device that does not use a safety input from the safety device for controlling the operation of the machine. The ineffective safety device can be switched between the first and second safety devices.   The safety management system according to claim 6, wherein the safety control device switches the invalid safety device between the first and second safety devices in accordance with a switching setting. The safety control device controls permission or prohibition of operation of the machine based on safety inputs given from the first and second safety devices,
The safety input is a safety input that allows the operation of the machine or a danger input that prohibits the operation of the machine,
Based on the safety inputs from the first and second safety devices, the safety control device sends one of the safety devices to the safety device and sends the safety-side safety input from the safety device to the machine. The safety management system according to claim 6, wherein the safety device is an invalid safety device that is not used for controlling the operation of the safety device, and the safety device to be disabled is switched between the safety devices according to the safety input of the safety devices.   In the state where the safety inputs from the first and second safety devices are both on the safe side, the safety control device refers to a safety device whose safety input has previously changed to the dangerous side as the invalid safety device. The safety management system according to claim 8. The first safety device monitors the approaching operation of the machine to the dangerous area, and when the approaching operation is detected, the approaching operation is detected as a safety-side safety input prohibiting the operation of the machine. If not, give each safety control device a safety input on the safe side that allows operation of the machine,
The second safety device monitors a human's entry operation into the dangerous area, and when the entry operation is detected, the safety operation on the dangerous side prohibiting the operation of the machine is detected as the entry operation. The safety management system according to any one of claims 6 to 9, wherein when there is not, a safety-side safety input that permits operation of the machine is provided to each of the safety control devices. A safety control device that controls the operation of the machine based on a safety input given by the safety device,
Safety inputs from at least two first and second safety devices that monitor the machine or human movement are provided;
The two safety devices are arranged so as to surround a dangerous area where the working space where the machine works and the working space where the human works are overlapped by both monitoring boundaries and separate safety guards that are monitored by each safety device. ,
The first safety device surrounds a work space in which only the machine works by the monitoring boundary and the separation safety guard, and the monitoring boundary is between the work space in which only the machine works and the dangerous area. It is arranged to be located in
Any one of the first and second safety devices is an invalid safety device that does not use a safety input from the safety device for controlling operation of the machine, and the invalid safety device. Can be switched by the first and second safety devices.   The safety control device according to claim 11, wherein the invalid safety device is switched between the first and second safety devices according to a switching setting. Based on the safety input from the at least two first and second safety devices, control whether to allow or prohibit the operation of the machine,
The safety input is a safety input that allows the operation of the machine or a danger input that prohibits the operation of the machine,
Based on the safety inputs of the first and second safety devices, any one of the safety devices is not used for the control of the operation of the machine using the safety input on the dangerous side from the safety device. The safety control device according to claim 11, wherein the safety device is an invalid safety device, and the safety device to be invalidated is switched between the safety devices according to the safety input of the both safety devices.   The safety device whose safety input has been changed to a dangerous side in the state where safety inputs from the first and second safety devices are both on the safe side is the invalid safety device. Safety control equipment. The first safety device monitors an approaching operation to a dangerous area where the working space of the machine and a human working space overlap, and when an approaching operation is detected, the first safety device prohibits the operation of the machine. When safety input is not detected, the safety side safety input that allows the machine to operate is given.
The second safety device monitors a human's entry operation into the dangerous area, and when the entry operation is detected, the safety operation on the dangerous side prohibiting the operation of the machine is detected as the entry operation. The safety control device according to any one of claims 11 to 14, wherein when there is not, a safety-side safety input that permits operation of the machine is provided.   16. A safety output is given to a safety output control target according to a program based on a safety input from the safety device to control the operation of the machine, and a semiconductor output is given as the safety output. The safety control device according to any one of the above.   17. The safety control according to claim 16, wherein an input for logical connection is given from another safety control device, and a logical operation of the logical connection input and the safety input is performed to give the safety output to the safety output control target. machine.

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