| 摘要 |
An engine cooling system and a control method thereof are provided to improve fuel efficiency and reduce noise of a cooling fan by varying the rotation of the fan in accordance with the temperature of coolant. A bypass line(BL) interconnects a coolant supply line(L1) and a coolant discharge line(L2), and a valve plate(13) is arranged at one side of the bypass line such that the valve plate is operated by a first actuator(11) and opens/shuts the coolant discharge line or the bypass line. A coolant temperature sensor(15) is arranged at one side of the coolant discharge line. A cooling fan(7) has a rotating shaft(9) which is rotatably supported by a fixing element(17) through a bearing(19). The rotating shaft has a front end equipped with a variable pulley(21) connected to a crank shaft pulley(23) of an engine through a belt(25). A fixed idle pulley is rotatably mounted at one side of a cylinder block(1) in correspondence to the right side of the variable pulley, and connected to the belt. An adjustment bar has one end hinge-coupled to the other side of the cylinder block in correspondence to the left side of the variable pulley. The adjustment bar has a front end equipped with an adjustment idle pulley(45). A second actuator(47) is hinge-coupled to the let side of the center of the cylinder block. The second actuator has an operating rod(49) connected to one side of the adjustment bar. A controller(60) receives signals from an engine RPM sensor(50) and the coolant temperature sensor, and operates the first and second actuators. |
