Patent ID: 7775268
Filing Date: 2010-08-17
Classification: B60H

Abstract:
1. A vehicle cooling system comprising: a vehicle unit having a coolant outlet and a coolant inlet with a coolant route therebetween; a heat exchanger configured and arranged in the coolant route to selectively receive a coolant from the coolant outlet of the vehicle unit; a cooling fan configured and arranged to blow cooling air to the heat exchanger; a coolant pump configured and arranged to circulate the coolant through the coolant route; a three-way valve configured and arranged to switch the coolant route between a heat exchanger route that passes through the heat exchanger and a bypass route that bypasses the heat exchanger; and a control unit that controls operation of the three-way valve based on a temperature of the coolant at the heat exchanger and a temperature of the coolant at the coolant outlet of the vehicle unit, the control unit electrically controlling an opening speed of the three-way valve with which the coolant route is switched from the bypass route to the heat exchanger route upon detection of the temperature of the coolant at the heat exchanger and the temperature of the coolant at the coolant outlet by the control unit, the control unit controlling the opening speed to switch the coolant route from the bypass route to the heat exchanger route such that as a difference between the temperature of the coolant at the coolant outlet of the vehicle unit and the temperature of the coolant at the heat exchanger becomes larger, the opening speed of the three-way valve becomes slower, with the opening speed being a percentage of the three-way valve that is opened per unit time.