PROBLEM TO BE SOLVED: To improve the work efficiency of a working vehicle by preventing the overheat of an engine, and enhancing an engine output.SOLUTION: A cooling fan (20) and a dust discharge fan (30) whose blade angles are set reverse with respect to each other are concentrically arranged between an engine (E) and a radiator (50) so as to be turnable, there are arranged a cooling clutch (C1) for connecting and blocking the transmission of a drive force to the cooling fan (20) from the engine (E), a dust discharge clutch (C2) for connecting and blocking the transmission of a drive force to the dust discharge fan (30) from the engine (E), and drive state changeover means (45) for operating the connection and block of the cooling clutch (C1) and the dust discharge clutch (C2), and also there is arranged a control device (U) which automatically operates the drive state changeover means (45) at a start of the engine (E), connects the cooling clutch (C1), and blocks the dust discharge clutch (C2).SELECTED DRAWING: Figure 10COPYRIGHT: (C)2016,JPO&INPIT【課題】エンジンのオーバーヒートを防止し、エンジン出力を高めて作業車輌の作業能率を向上させる。【解決手段】エンジン(E)とラジエータ(50)の間に、互いの翼角度を逆に設定した冷却ファン(20)と排塵ファン(30)を同一軸心上に回転自在に設け、エンジン(E)から冷却ファン(20)への駆動力の伝達を接続および遮断する冷却クラッチ(C1)と、エンジン(E)から排塵ファン(30)への駆動力の伝達を接続および遮断する排塵クラッチ(C2)と、冷却クラッチ(C1)及び排塵クラッチ(C2)を接続及び遮断操作する駆動状態切換手段(45)を設け、エンジン(E)の始動時に、駆動状態切換手段(45)を自動的に作動させ、冷却クラッチ(C1)を接続すると共に排塵クラッチ(C2)を遮断する制御装置(U)を備える。【選択図】図10
