PROBLEM TO BE SOLVED: To provide an endoscope tube channel switching device in which a check valve has improved durability by preventing the turning-up from spreading to a wide range even if a part of the check valve is turned up when the check valve repeatedly slides on the inner circumferential surface of a cylinder.SOLUTION: A check valve unit 160 includes low-strength sections 165 and high-strength sections 167 which are disposed at a distal portion side of the moving check valve unit 160 and have mutually different strengths. The low-strength sections 165 and the high-strength sections 167 are disposed in alternation in the peripheral direction of the check valve unit 160.COPYRIGHT: (C)2014,JPO&INPIT【課題】 逆止弁がシリンダ内周面を繰り返し摺動する際、逆止弁の一部がめくられても、めくれが広い範囲に波及することを防止し、逆止弁の耐久性が向上された内視鏡管路切換装置を提供すること。【解決手段】 逆止弁ユニット160は、移動する逆止弁ユニット160の先頭部分側に配設され、互いに強度が異なる低強度部165と高強度部167とを有する。低強度部165と高強度部167とは、逆止弁ユニット160の周方向において交互に配設されている。【選択図】 図2D
