| 摘要 |
<p>A radiator (12a) and an oil cooler (12b) are disposed separately from an engine (11) of a construction machine and cooled by a cooling fan (15). The oil cooler (12b) is located downstream from the radiator (12a) with respect to the air flow generated when the cooling fan (15) is driven in reverse. A hydraulic motor (32) is adapted to be controlled by a directional control solenoid valve (34) of a fan driving circuit (31) so that the cooling fan (15) may be stopped, rotated forward or rotated in reverse accordingly. The directional control solenoid valve (34) is adapted to be automatically switched by a control device (41) having temperature sensors (44),(45),(46). The control device (41) is adapted to rotate the cooling fan (15) in reverse in cases where the temperature of the cooling water is not lower than a given temperature while the temperature of the hydraulic oil is lower than a given temperature, thereby causing the warm air which has passed the radiator (12a) to warm the hydraulic oil in the oil cooler (12b) and also causing back flow of the air to discharge debris lodged in the radiator (12a) and other components. <IMAGE></p> |
