PROBLEM TO BE SOLVED: To provide a drain tube in which rigidity of a connection pipe part is sufficiently secured, and a flow channel is hardly clogged as a whole.SOLUTION: A drain tube 10 having flexibility is integrally provided with: a suction tube part 20 having a partition part 22 for partitioning the inside into a plurality of flow channels in an axial direction, and an opening 26 extending along the axial direction X to each of exterior walls 25 of the plurality of flow channels 21 partitioned by the partition part 22； an outflow tube part 40 having a single flow channel 41； and a connection pipe part 30 for connecting the suction tube part 20 and the outflow tube part 40. The drain tube is such that: the connection pipe part 30 has a plurality of belt-like projections 34 projecting inward from an inner wall 33 and extending along the axial direction X； and the plurality of belt-like projections 34 have a projection length L2 which becomes gradually shorter from the suction tube part 20 to the outflow tube part 40.SELECTED DRAWING: Figure 8COPYRIGHT: (C)2020,JPO&INPIT【課題】連結管部の剛性が充分に確保され、かつ全体として流路が詰まりにくいドレーンチューブを提供する。【解決手段】内部を軸方向に複数の流路に分割する仕切り部２２と、仕切り部２２で仕切られた複数の流路２１のそれぞれの外壁２５に軸方向Ｘに沿って延びる開口２６とを有する吸引管部２０、単一の流路４１を有する流出管部４０、及び吸引管部２０と流出管部４０とを連結する連結管部３０を、一体的に備え、可撓性を有するドレーンチューブ１０であって、連結管部３０が、内壁３３から内方に向かって突出した軸方向Ｘに沿って延びる複数の帯状突起部３４を有し、複数の帯状突起部３４が、吸引管部２０から流出管部４０に向かって徐々に突出長さＬ２が短くなるドレーンチューブとする。【選択図】図８
