Patent ID: 8489222

Claim:
A machine for grinding a spacer grid of a nuclear fuel assembly, comprising: a spacer grid holding unit directly holding a spacer grid on grinding operation and including: a holding jig on which the spacer grid is seated and held; a rotary index table being coupled to a lower end of the holding jig and rotating the holding jig; a first holder installed beside the holding jig, operated by a first air cylinder and holding the spacer grid from a side of the spacer grid; and a second holder operated by a second air cylinder and holding the spacer grid from a to of the spacer grid; a first rectangular coordinates robot for grinding a lateral side of the spacer grid on the spacer grid holding unit, the first rectangular coordinates robot positioned beside the spacer grid holding unit and including: a moving unit moving in three-axial directions; a rotary motor installed on the moving unit; a rotary plate supported by the moving unit and coupled on a shaft of the rotary motor; and a grinding wheel provided on the rotary plate; a second rectangular coordinates robot for grinding a corner of the spacer grid on the spacer grid holding unit, the second rectangular coordinates robot positioned beside the spacer grid holding unit and including: a guide rail unit movable towards or away from the holding jig in horizontal direction; a lift block movable in vertical direction on the guide rail unit; a second robot body coupled to the lift block; a grinding tool coupled to the second robot body; and a grinding tip removably coupled to a front end of the grinding tool; and a control unit controlling the machine to conduct an operation for grinding the spacer grid.