PROBLEM TO BE SOLVED: To improve an efficiency of field working by reducing a frequency of dust removing by suppressing a dust attach to a dust proof screen and a radiator core.SOLUTION: A dust proof screen (29) having an area ranging over a whole surface of an intake side core (21a) of a radiator (21) of an engine (E) is removably provided along a guide arranged to a radiator (21) side frame part, and the dust proof screen (29) is configured in a fine mesh texture. A vertically long shielding plate (30) is left-and-right slidably supported in a hanged position so as to cover a part of the dust proof screen (29), so that the vertically long shielding plate (30) and is configured to be reciprocated by a left-and-right drive mechanism (Y) at an arbitrary timing or a suitably set timing.COPYRIGHT: (C)2012,JPO&INPIT【課題】 防塵スクリーンあるいはラジエータコアへの塵埃付着を抑制して除塵作業の頻度を少なくし、圃場作業効率の向上を図る。【解決手段】エンジン(E)のラジエータ(21)の吸気側コア(21a)全面に亘る面積の防塵スクリーン(29)をラジエータ(21)側枠部に設けたガイドに沿わせて抜き差し自在に設け、該防塵スクリーン(29)は細かい目合の網膜状に構成し、この防塵スクリーン(29)の一部を覆うように縦長の遮蔽板(30)を左右摺動自在に吊持姿勢に支持し、前記遮蔽板(30)を左右駆動機構(Y)によって任意のタイミングで、又は適宜設定されたタイミングで往復移動すべく構成する。【選択図】 図5
