摘要 |
In injection-molding first and second blade bodies (2, 3), convex parts (23, 32) are formed on the surfaces of the first and second blade bodies (2, 3), respectively. Then, a horn (16) of an ultrasonic welding device is placed at a position of crossing both the convex parts (23, 32) to come into contact with the top surfaces of the convex parts (23, 32) while pressing them at the same time, and in this state, the ultrasonic welding device is operated. Contact surfaces of the first and second blade bodies (2, 3) are welded at their portions corresponding to a pressing direction of the horn (16) and concurrently, both the convex parts (23, 32) are deformed by melting under pressure through the horn (16) to trickle melting resin of both the convex parts (23, 32) into a clearance (10) between the first and second blade bodies (2, 3), so that both the blade bodies (2, 3) are joined to each other. <IMAGE> |