| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a resonator attached to an intake pipe for an automobile is indispensable attenuate sound energy by making engine suction noises of the automobile resonate in the resonance box of the resonator attached to the intake pipe for an automobile formed by blow molding of a thermoplastic resin.SOLUTION: The manufacturing method of a vent tube comprises as follows. A sound absorbing material is put on a bag rubber object which is fitted and locked beforehand to a slide core set in a split mold so as to independently operate with the split mold and in which the shape is conserved by pressurization, subsequently a parison is made to sag so as to include the bag rubber object with the sound absorbing material and the slide core, and the split mold is clamped, subsequently compressed air is blown into the parison and the bag rubber object simultaneously to be shaped, thereafter an inner pressure of insides of the parison and the bag rubber object is released, the bag rubber object and the slide core are taken out from the parison and the sound absorbing material, the split mold is opened, and the parison is released. |
