To enable an exchange of cutting blades with little manpower in the combine which has a waste straw shredding machine for performing shredding processing on threshed waste straws that includes a driving blade body that has a plurality of cutting blades supported by a driving shaft, a receiving blade body that has a plurality of receiving blades supported by a cutting shaft, and the case for storing the driving blade body and the receiving blade body.SOLUTION: A driving blade body 34 is configured to be switchable between a usage state where both end parts of a driving shaft are supported by left and right lateral walls of a case 31 and an overhang state where one end part of the driving shaft protrudes outside the case 31 while the other end part of the driving shaft is supported by the left lateral wall.SELECTED DRAWING: Figure 2【課題】脱穀処理後の排ワラを切断処理する排ワラ切断装置に、駆動軸に支持された複数の切断刃を有する駆動刃体と、切断軸に支持される複数の受刃を有する受刃体と、駆動刃体及び受刃体を収容するケースと、が備えられているコンバインにおいて、切断刃の交換を少ない人手で迅速にできるようにする。【解決手段】駆動刃体３４は、駆動軸の両端部がケース３１の左右の側壁に支持された使用状態と、駆動軸の一端部が左の側壁に支持されつつ、駆動軸の他端部がケース３１の外部に突出する張出状態と、に状態変更可能に構成されている。【選択図】図２
