| 摘要 |
PROBLEM TO BE SOLVED: To prevent increase of the operation load of an operation knob in closing a ventilation flue with an upstream side fin while suppressing pressure loss and noise generation.SOLUTION: One of a plurality of upstream side fins 41 to 45 is configured as a specified upstream side fin 41 having a transmission shaft part 62 extending in parallel with an upstream side fin shaft 47. An operation knob 70 is arranged so as to be slidable in the axial direction of a downstream side fin shaft 33, with respect to a downstream fin 32. The operation knob 70 has a pair of fork parts 71 sandwiching the transmission shaft part 62 and transmits, in the fork parts 71, a slide operation to the specified upstream side fin 41 through the transmission shaft part 62. The specified upstream side fin 41 is divided into a fin body 54 having an upstream side fin shaft 47 and a transmission body 60 having the transmission shaft part 62 and connected to the fin body 54. The transmission body 60 is supported on a case 10 with a support shaft 63 in a tiltable way, in a part of the fin body 54 deviated to the upstream side relative to the upstream side fin shaft 47. |
