Patent ID: 6857398
Filing Date: 2005-02-22
Classification: F01P

Abstract:
1. A cooling system for an internal combustion engine, including a radiator provided in a coolant circulation path of the internal combustion engine, and an actuator that controls a flow rate of a coolant that passes through the radiator, wherein the actuator is controlled so that a coolant temperature of the internal combustion engine becomes substantially equal to a target coolant temperature, comprising: a calculating unit that calculates a cooling loss as a quantity of heat removed from the internal combustion engine and received by the coolant, based on an operating state of the internal combustion engine, and calculates a required radiator flow rate, based on the cooling loss, the target coolant temperature, and a temperature of the coolant that has passed through the radiator, the required radiator flow rate representing a quantity of the coolant required to pass through the radiator so as to make the coolant temperature substantially equal to the target coolant temperature; and a control unit that controls the actuator based on the required radiator flow rate obtained by the calculating unit, wherein the calculating unit further calculates a received/radiated heat quantity of at least one heat receiving/radiating circuit that is provided in the coolant circulation path and bypasses the radiator, and calculates the required radiator flow rate based on the received/radiated heat quantity, the cooling loss, the target coolant temperature and the temperature of the coolant that has passed through the radiator; and wherein the at least one heat receiving/radiating circuit comprises a plurality of heat receiving/radiating circuits, and wherein the calculating unit calculates the received/radiated heat quantity of the heat receiving/radiating circuits based on a junction flow rate measured at a meeting portion of the heat receiving/radiating circuits, a junction coolant temperature measured at the meeting portion, and the coolant temperature of the internal combustion engine.