| 摘要 |
PROBLEM TO BE SOLVED: To suppress interference sound and exfoliation sound, and hence lower a noise level as the whole of an outoor machine by constructing a grill using a wire formed into a zigzag form by folding it in the diredction of an air stream at a specific angle or larger. SOLUTION: A center member 1a is disposed at a portion corresponding to the center of a propeller fan, around which member 1a a wire 1c folded concentrically in a zigzag manner is disposed, and a wire 1b is disposed radially from the center member 1a, and further the wires 1b and 1c are fixed to each other for united construction of the whole grill. A grid shaped grill is constructed using the wire 1c a folded angleθof which is 15 degree or more, and is assembled such that an axis core of the wire 1c is inclined by 15 degree or more with respect to the direction of an air stream from a cross section intersecting the direction of a main air stream colliding the wire 1c. Hereby, an interference sound and an exfoliation sound are eliminated, and a noise level as the whole of the outdoor machine is lowered. |
