| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-cost propeller fan with a high air blowing performance and a manufacturing method therefor. SOLUTION: In the propeller fan 1 molded by an injection molding process, a blade 3 is of a good blade surface shape free from a sink mark and as such, exhibits a high air blowing performance by setting an injection position for a molten resin on the blade surface 3b. In addition, when the propeller fan 1 is injection-molded, a gate 29 is set at a position corresponding to the blade surface 3b of the blade 3 of the propeller fan 1. Consequently, the molten resin injected into a cavity 27 from the gate 29 flows toward a region side corresponding to the tip part of the blade 3 inside the cavity 27 and is packed there. In this case, as the gate 29 is set at a position, of the cavity 27, corresponding to the blade surface 3b of the blade 3, the flowing distance of the molten resin is short and the flow resistance is minimized. Thus the blade 3 with a sink mark-free good blade surface 3b is formed and the propeller fan 1 with a high air blowing performance is obtained. |
