Safety pin locking device for workpiece turnover and workpiece turnover system

A safety pin locking device for workpiece turnover, comprising:

• a safety pin configured to be inserted into a base and an overturnable workpiece to lock an angle of the overturnable workpiece relative to the base;
• a triangular lock plate with a first corner end connected to an axial surface of the safety pin by a fastener, wherein the triangular lock plate is rotatable around the fastener;
• an elastic positioning pin mounted at a second corner end of the triangular lock plate and configured to be inserted into positioning counterbores at two different positions on the axial surface of the safety pin to limit a position of the triangular lock plate, so as to pull out the safety pin from the overturnable workpiece or prevent the safety pin from being pulled out;
• and
• a lockset mounted at a third corner end of the triangular lock plate and configured to limit rotation of the triangular lock plate, wherein the triangular lock plate is rotated by unlocking the lockset and pulling out the elastic positioning pin, wherein:
• the safety pin comprises a pin shaft, wherein an axial surface of the pin shaft is provided with three holes that respectively are a threaded fixing hole, a positioning counterbore I, and a positioning counterbore II, lines connecting centers of the three holes form a regular triangle, and a center of the regular triangle coincides with an axis of the pin shaft;
• the triangular lock plate has a regular triangular flat plate structure, the three corner ends are provided with a hinged through hole, an internal threaded mounting hole and a lock hole, respectively, and lines connecting centers of the hinged through hole, the internal threaded mounting hole and the lock hole form a regular triangle, with a hole spacing consistent with a hole spacing of the three holes in the safety pin;
• when the elastic positioning pin is mounted in the internal threaded mounting hole and then inserted into the positioning counterbore I, a geometric shape of the triangular lock plate is all within a diameter range of the safety pin, so as not to prevent the safety pin from being pulled out of or inserted into the overturnable workpiece;
• when the elastic positioning pin is mounted in the internal threaded mounting hole and then inserted into the positioning counterbore II, a corner of the triangular lock plate deviates from the diameter range of the safety pin, such that the safety pin is not allowed to be pulled out from the overturnable workpiece;
• and
• the lockset is mounted in the lock hole in the corner end deviated from the diameter range of the safety pin.