Casing forming apparatus of the centrifugal blower

PROBLEM TO BE SOLVED: To provide a device moldable without causing thermal deformation on partial manufacture in a side plate and a back board even if a casing of a centrifugal blower is enlarged, and also moldable by substantially continuing a process of forming a seaming groove in the back board and a process of meshing and joining the side plate on one device. SOLUTION: This casing molding device includes a molding roll 7 for molding the seaming groove 6 forming a cross-sectional U shape required as the back board 3 on both side edges of a belt-like plate 20 and sending out a work, and a seam roller 8 for fixing the side edge of the back board 3 to the peripheral edge of the side plate 2 by deforming the seaming groove 6 fitted with an edge part of the side plate 2 by pressing from the side. The casing 4 of the centrifugal blower for forming a spiral chamber 5 for an impeller is molded by fixing the back board 3 to the opposed two side plates 2 having the peripheral edge of continuing a spiral edge part 2A and a straight line-shaped edge part 2B so as to surround the peripheral edge (see, Fig.5 and also Fig.20). COPYRIGHT: (C)2011,JPO&INPIT