| 摘要 |
<p>The invention provides a pipe wherein operability is enhanced. A pipe body (11) possesses an internal layer (14) restricating an integral inner circuference, an external layer (15) restricating an intergral outer circuference, and an interlayer (16) holding by the internal layer (14) and the external layer (15). The internal layer (14) and the interlayer (16) are prepared from the same material along the axis direction. The external layer (15) is formed with different hardness at the axis direction. At the three-layer structure zone of the pipe body (11), an inside and outside cone area (33) with internal and external diameters reduced toward the exterior. Accordingly, at the far end portion of the inside and outside cone area (33), no boundary of different hardness of material at the external layer (15) exists.</p> |
