PROBLEM TO BE SOLVED: To provide an endoscope capable of reducing discomfort upon insertion caused by meandering of a coil spring.SOLUTION: A soft part of an endoscope includes a hardness variable portion 35 for varying flexural rigidity. The hardness variable portion 35 has a wire 31 and a coil spring 33 which relatively move in accordance with the operation of a hardness adjustment knob, and varies the flexural rigidity by compressing the coil spring 33. The increase of compression strength generates a meandering of the coil spring 33. The meandering of the coil spring 33 varies radial flexural rigidity of the soft part at a plurality of positions in the circumferential direction of an axis at a certain axial position. Then, the difference value between the maximum value and the minimum value of the flexural rigidity of the hardness variable portion 35 is set to be 0.2 or less of the flexural rigidity of the soft part including all built-in objects except the hardness variable portion 35.COPYRIGHT: (C)2015,JPO&INPIT【課題】コイルバネの蛇行に起因する挿入時の違和感を解消する内視鏡を提供する。【解決手段】内視鏡の軟性部は、曲げ硬さを変えるための硬度可変部材35を内蔵する。硬度可変部材35は、硬度調整ノブの操作に応じて相対的に移動するワイヤ31とコイルバネ33を有し、コイルバネ33に圧縮力を加えて曲げ硬さを変える。圧縮力を高めるとコイルバネ33に蛇行が生じる。コイルバネ33が蛇行すると、軟性部は、軸方向の同じ位置において軸周り方向の複数位置での半径方向の曲げ硬さが変化する。この時の硬度可変部材35の曲げ硬さの最大値及び最小値の差を、硬度可変部材35を除いた内蔵物を含む軟性部の曲げ硬さの0.2倍以下になるように構成する。【選択図】図8
