| CPC B21D 5/0209 (2013.01) [B21D 55/00 (2013.01); G01V 8/12 (2013.01)] | 8 Claims |
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1. An optical safety device for monitoring entry of foreign matter between an upper tool and a lower tool of a press brake, the optical safety device comprising:
a beam projector provided on one side in a length direction of an upper table of the press brake and configured to project a monitoring beam passing through an area and surroundings immediately below the upper tool toward another side in the length direction of the upper table;
a beam receiver provided on the other side in the length direction of the upper table and configured to receive the monitoring beam; and
a monitoring controller comprising:
a received beam amount acquisition section configured to acquire a received beam amount of the beam receiver at certain sampling time intervals; and
a beam shielding detection section configured to detect presence or absence of beam shielding of the monitoring beam by determining whether or not the acquired received beam amount of the beam receiver is lower than a determination threshold for detecting the presence of beam shielding of the monitoring beam,
wherein a detection sensitivity of the beam shielding detection section is configured to be switched from a normal sensitivity mode to a high sensitivity mode when:
a bending process by use of the press brake is an initial process based on a predetermined processing program, and
a height position of the beam receiver is lower than a predetermined height position that is a position immediately above a height position of an upper surface of a workpiece set in the predetermined processing program.
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