PROBLEM TO BE SOLVED: To provide a straw cutting blade with excellent cutting performance and durability.SOLUTION: A straw cutting blade is constituted as follows: blade plate parts 4 are projected in parallel at the right and left of a mounting plate part 3 which mounts a plate 2 bent in U-shaped to a threshing part. At an edge part of the blade plate part 4, an uneven blade edge 7, with which a sharp top part 5 and a sharp valley part 6 are continuously formed from a base end part to a projection tip part of the blade plate part 4, is formed. A blade height dimension H of the uneven blade edge 7 on a projection tip side of the blade plate part 4 is formed so as to be higher than a blade height dimension H of the uneven blade edge 7 on a base end side of the blade plate part 4. An adjacent pitch P of the sharp top part 5 on the projection tip side of the blade plate part 4 is set so as to be wider than an adjacent pitch P of the sharp tip part 5 on the base end side of the blade plate part 4.COPYRIGHT: (C)2015,JPO&INPIT【課題】切断性・耐久性に優れたわら切刃を提供すること。【解決手段】板材2をコ字状に折曲形成して前記脱穀部に取付する取付板部3の左右に刃板部4を並設状態に突設した構成とし、この刃板部4の縁部に、刃板部4の基端部から突出先端部にかけて先鋭頂部5と先鋭谷部6とが連続した凹凸刃縁7を形成し、この凹凸刃縁7は、前記刃板部4の突出先端側に存する凹凸刃縁7の刃高寸法Hを、刃板部4の基端側に存する凹凸刃縁7の刃高寸法Hより高くなる形状に形成すると共に、刃板部4の突出先端側に存する先鋭頂部5の隣接ピッチPを、刃板部4の基端側に存する前記先鋭頂部5の隣接ピッチPより広く設定する。【選択図】図4
