Safety devices

Abstract

This safety device provides a mechanism that avoids false detection of light other than the light emitted from the floodlight, enabling accurate safety management of the processing machine. [Solution] The safety device 50 comprises a light emitter 60 that emits detection light LB at predetermined time intervals, a light receiver 70 that outputs a determination signal Sd2 indicating whether or not the light receiving element 80 is detecting light, and a safety control unit 102. The safety control unit 102 periodically determines whether or not the light receiving element 80 is detecting light based on the determination signal Sd2 output from the light receiver 70 during periods when the light emitter 60 is not emitting detection light LB. If it determines that the light receiving element 80 is detecting light, it stops the operation of the processing machine and stops the emission of detection light LB from the light emitter 60. Subsequently, if it determines that the light receiving element 80 is not detecting light, it resumes the emission of detection light LB from the light emitter 60 and restores the processing machine to an operational state.

Claims

1. A safety device for managing the safety of a processing machine performing prescribed operations, A floodlight that emits light rays at predetermined time intervals, A photodetector that includes a light-receiving element for detecting light and outputs a determination signal indicating whether or not the light-receiving element is detecting light, A safety device comprising: a safety control unit that periodically determines whether the light-receiving element is detecting light based on a determination signal output from the light receiver during periods when no light rays are emitted from the light emitter, and if it is determined that the light-receiving element is detecting light, it stops the operation of the processing machine and stops the emission of light rays from the light emitter, and if it is determined that the light-receiving element is not detecting light based on a determination signal output from the light receiver after the emission of light rays has been stopped, it restarts the emission of light rays from the light emitter and restores the processing machine to an operational state.

2. The safety device according to claim 1, wherein the safety control unit, after stopping the emission of the light ray, determines that the light receiving element has detected light based on the determination signal output from the light receiver, and outputs an abnormality signal.

3. The safety control unit periodically monitors the determination signal output from the light receiver during periods when no light beam is emitted from the light emitter, and when it recognizes that the light receiving element has detected light for a predetermined number of consecutive times, it determines that the light receiving element has detected light, as described in claim 1.

4. The aforementioned processing machine is a bending machine, The safety device according to claim 1, wherein the safety control unit stops the operation of the bending machine by deactivating the processing operation instruction to the bending machine when the emission of light rays from the floodlight is stopped, and restores the bending machine to an operational state by reactivating the processing operation instruction to the bending machine when the emission of light rays from the floodlight is restarted.

5. The safety control unit consists of two systems, a first control unit and a second control unit, and the determination signals sequentially output from the light receiver are acquired alternately by the first control unit and the second control unit. When the first control unit or the second control unit acquires a determination signal indicating that the light-receiving element has detected light a predetermined number of times consecutively, In the first control unit and the second control unit, when the cumulative number of times a determination signal indicating that the light receiving element has detected light is obtained exceeds a predetermined value, The safety device according to claim 1, which stops the emission of light rays from the floodlight and stops the operation of the processing machine.

6. The safety device according to claim 5, wherein the safety control unit, when the first control unit and the second control unit acquire a determination signal indicating that the light receiving element is not detecting light for a predetermined number of consecutive times, restarts the emission of light rays from the light emitter and restores the processing machine to an operational state.

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