Fan rotational frequency control method

• Main Authors: OKAMOTO KAZUNARI, ADACHI SATOYUKI, FURUTA HIDETO
• Format: Patent
• Language: Chinese; English
• Published: 12.03.2008
• Subjects: BLASTING; COOLING OF INTERNAL-COMBUSTION ENGINES; COOLING OF MACHINES OR ENGINES IN GENERAL; DREDGING; ENGINE PLANTS IN GENERAL; FIXED CONSTRUCTIONS; FOUNDATIONS; HEATING; HYDRAULIC ENGINEERING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; NON-POSITIVE DISPLACEMENT PUMPS; POSITIVE DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS; SOIL SHIFTING; STEAM ENGINES; WEAPONS

Temperature of each cooling target fluid is detected. When the flow rate of a cooling target fluid passing through a cooling means (30) is high, such as when either one or both of the levers are being operated, the fan revolution speed of a cooling fan (17) of the cooling means (30) is controlled to achieve a target fan revolution speed (Ntf) so that the detected temperature of the cooling target fluid reaches a preset target temperature. In cases where the engine is in either AEC state or one-touch low idling state with the levers at the neutral position, the flow rate of each cooling target fluid passing through the cooling means (30) is reduced. Therefore, the fan revolution speed of the cooling fan (17) is controlled to achieve a new target fan revolution speed (Ntfnew) that is lower than the target fan revolution speed (Ntf). At that time, a new target fan revolution speed (Ntfnew) for the period during which the levers are at the neutral position is calculated by multiplying the fan revolution speed (Nt