Patent ID: 7968818

Claim:
An apparatus for welding strap connections between inner grid straps of a spacer grid using a laser tool, in which the strap connections between the inner grid straps ( 4 a and 4 b ) and between the inner and outer grid straps in the spacer grid ( 3 ) for a nuclear fuel bundle are welded, the apparatus comprising: the laser tool ( 10 ) including a pair of laser tools ( 10 a and 10 b ) that have a cylindrical shape and are spaced apart from each other by a predetermined interval, a plate-like connecting piece ( 11 ) that is interposed between the laser tools ( 10 a and 10 b ) in order to connect the laser tools ( 10 a and 10 b ), and optical fibers ( 12 ) that are inserted into and connected to upper ends of the laser tools ( 10 a and 10 b ) by optical fiber connectors ( 12 a ) and transmit laser beams; and a controller ( 30 ) including a plate-like supporting piece ( 31 ) that is connected to a center of the plate-like connecting piece ( 11 ) of the laser tool ( 10 ), a movable piece ( 33 ) that is connected to the plate-like supporting piece ( 31 ), and a linear driver ( 35 ) that is connected to the movable piece ( 33 ), wherein each of the laser tools ( 10 a and 10 b ) includes an alignment lens ( 15 ) provided on an upper inner side thereof in order to align the transmitted laser beam, a focusing lens ( 16 ) provided on a lower side thereof in order to focus the laser beam passing through the alignment lens ( 15 ), and a prism ( 17 ) provided below the focusing lens ( 16 ) in order to transmit the laser beam focused by the focusing lens ( 16 ) in a predetermined direction, wherein each of the laser tools ( 10 a and 10 b ) includes a through-hole ( 19 ) formed at a suitable position in a lower outer circumference thereof so as to pass the laser beam transmitted through each prism ( 17 ), wherein each of the laser tools ( 10 a and 10 b ) includes an alignment lens ( 15 ) provided on an upper inner side thereof in order to align the transmitted laser beam, a focusing lens ( 16 ) provided on a lower side thereof in order to focus the laser beam passing through the alignment lens ( 15 ), and a concave copper mirror provided below the focusing lens ( 16 ) in order to transmit the laser beam focused by the focusing lens ( 16 ) in a predetermined direction, further comprising a spacer grid jig ( 50 ) that has fixing holes ( 51 ) in a grid arrangement in order to fix the spacer grid ( 3 ), and a laser tool jig ( 70 ) that has a plurality of guide holes ( 71 ) in order to vertically fix the laser tools ( 10 a and 10 b ) of the laser tool ( 10 ).