| 摘要 |
PROBLEM TO BE SOLVED: To suppress a local noise to be generated in a bend part even in the case where a nozzle is sharply curved at the outlet part with respect to a high speed air flow noise flowing in the duct having a small diameter by providing an opening part at the front side of a speaker. SOLUTION: In a bend 9 connected to change the direction of an exhaust at the outlet part 2b of a duct 2, when the wind-speed of air flowing in the duct 2 is fast. the unevenness of speeds of air flow is generated and an opening 10 is provided at the upper part of a speaker 7 to prevent the local noise from being generated by the aireddy generated as a result-That is. the opening part 10 is provided as another discharge port at the terminal part of the straight part 2a of the duct 2 confronted to the speaker 7. It is preferred that the size of the opening part 10 is ranging from the center position of the speaker 7 to the outlet part 2b. Then, the wind amount flowing in a bend 9 is reduced by the existence of the opening part 10 and the effect preventing the local noise from being generated is obtained as a result. Moreover, the structure of the opening part 10 is made only by making a window in the duct 2. |
