| 摘要 |
PURPOSE:To avoid the direct contact of an inner wall with a nozzle by providing a moving mechanism moving the nozzle so as to approach and separate with respect to the inner wall surface of a cylindrical body, an energizing mechanism energizing the nozzle toward the inner wall surface and a spaced-apart distance limiting mechanism limiting the approaching distance between the inner wall surface and the nozzle to the min. value. CONSTITUTION:A nozzle mechanism 2 is mounted to a driving rotary shaft 2a and each nozzle 2b is formed by connecting the fixed nozzle 2b' mounted to the driving rotary shaft 2a so as to extend and contract in the diameter direction of a cylindrical body 10 and the movable nozzle 2b' freely slidable with respect to said nozzle 2b' through the spring 3a energizing the nozzle 2b outwardly in the diameter direction of the rotary shaft 2a. A pair of rollers 3c are mounted to the movable nozzle 2b'' through a support metal fitting 3b and, as the roller 3c comes into contact with the inner wall surface 11 of the cylindrical body 10, the movable nozzle 2b'' is inwardly altered in its position in the diameter direction of the driving rotary shaft 2a against the energizing of the spring 3a. The min. value of the approaching distance between the inner wall surface 11 and the nozzle 2b is prescribed by a support jig 3b and the roller 3c and the contact of the inner wall surface 11 with the nozzle 2b is prevented. |
