| 摘要 |
PURPOSE:To reduce the deformation of both a duct and a resonator so as to obtain the duct durable and withstanding even under long-term use and dispense with the connecting work of the duct and resonator prior to use by eliminating a joint between the duct and the resonator, and connecting the duct and the resonator integrally in the state of making up each other. CONSTITUTION:A curved blow-molded duct 10 is formed of a soft part and a hard part. A part of the soft part 10b is formed into a bellows part 14. At least one resonator 11 is integrally formed along the outside of the partial side face fo the hard part 10a by a single parison made of thermoplastic synthetic resin. The duct 10 and the resonator 11 are communicated with each other in the ventilated state by a partial communicating part 12. As a result, the duct 10 and the resonator 11 are integrally connected in the state of making up each other so as to reduce the deformation of both, thereby obtaining the duct 10 durable and withstanding even under long-term use and dispensing with the connecting work of the duct 10 and resonator 11 heretofore necessary prior to use. |
