Controller for engine cooling system

Abstract

An internal combustion engine has a cylinder-head-passage through which an engine coolant flows toward a water jacket when a water pump is operated. The water pump is an electric water pump utilizing the electric power charged in the battery. A radiator is provided in the cylinder-head-passage. Even after the engine is shut off, the water pump is kept driven.

1 . A controller for an engine cooling system in which an electric pump is controlled in such a manner as to circulate a coolant so that a cylinder head of an internal combustion engine is cooled, comprising:
 a temperature obtaining means for obtaining a temperature of the coolant;   a temperature determination means for determining a target temperature of the coolant at which an anti-knocking ability of the internal combustion engine is improved; and   a cooling control means for driving the electric pump to cool the cylinder head even after the internal combustion engine is shut off in a case that the temperature of the coolant obtained by the temperature obtaining means exceeds the target temperature determined by the temperature determination means.   
     
     
         2 . A controller for an engine cooling system according to  claim 1 , wherein
 the temperature determination means continues to execute a target temperature determination processing even after the internal combustion engine is shut off.   
     
     
         3 . A controller for an engine cooling system according to  claim 1 , wherein
 the engine cooling system is applied to an engine cooling system of a hybrid vehicle equipped with both an internal combustion engine and an electric motor,   the cooling control means continues to drive the electric pump even when the temperature of the coolant becomes less than the target temperature of the coolant in a case that the internal combustion engine is shut off and a vehicle speed is greater than or equal to a specified value.   
     
     
         4 . A controller for an engine cooling system according to  claim 1 , wherein
 the cooling control means includes:   a first cooling control means for increasing a coolant flow rate in such a manner that the coolant flow rate becomes greater than an reference flow rate in a case that the temperature of the coolant obtained by the temperature obtaining means is greater than the target temperature of the coolant; and   a second cooling control means for decreasing the coolant flow rate in such a manner that the coolant flow rate becomes less that the reference flow rate in a case that a difference between the temperature of the coolant obtained by the temperature obtaining means and the target temperature of the coolant is within a specified range.   
     
     
         5 . A controller for an engine cooling system according to  claims 1 , wherein
 the engine cooling system includes a radiator which cools the coolant by heat-exchanging with ambient air, and   the temperature determination means obtains an ambient air temperature and determines the target temperature in such a manner as to be greater than the ambient air temperature.   
     
     
         6 . A controller for an engine cooling system according to  claim 5 , wherein
 the radiator is arranged downstream of a refrigerant condenser of an air conditioner, and   the temperature determination means determines the target temperature of the coolant so that the target temperature is greater than a specified temperature which is obtained by adding an addition temperature to the ambient air temperature, wherein the addition temperature corresponds to a heat radiation quantity of the refrigerant condenser.   
     
     
         7 . A controller for an engine cooling system according to  claim 1 , wherein
 the engine cooling system includes a radiator and an electric cooling fan, the radiator cooling the coolant by heat-exchanging with ambient air, the electric cooling fan introducing the ambient air toward the radiator, further comprising:   a cooling fan control means for driving the electric cooling fan even after the internal combustion engine is shut off in a case that the temperature of the coolant exceeds the target temperature of the coolant, wherein   in a case that the internal combustion engine is started while the electric pump is stopped, the cooling control means starts driving the electric pump even though the temperature of the coolant does not exceeds the target temperature of the coolant,   in a case that the temperature of the coolant does not exceeds the target temperature of the coolant, the cooling fan control means does not starts the electric cooling fan even though the internal combustion engine is started while the electric cooling fan is stopped, and in a case that the temperature of the coolant exceeds the target temperature of the coolant, the cooling fan control means starts the electric cooling fan.   
     
     
         8 . A controller for an engine cooling system according to  claim 5 , wherein
 the temperature obtaining means obtains a temperature of the coolant in the radiator, a water jacket of the cylinder head, an outlet of the water jacket, or an inlet of the water jacket.   
     
     
         9 . A controller for an engine cooling system according to  claim 8 , wherein
 the temperature obtaining means obtains a temperature of the coolant in the water jacket of the cylinder head or the outlet of the water jacket.   
     
     
         10 . An air-conditioning system for an automobile, comprising a heat-exchanger for heating an air with a coolant of an internal combustion engine, wherein
 the internal combustion engine includes a first coolant outlet through which the coolant passed through a cylinder head flows out, and a second coolant outlet through which the coolant passed through a cylinder block flows out,   the heat-exchanger is comprised of a first exchanging portion and a second exchanging portion,   the first exchanging portion receives the coolant from at least the first coolant outlet, and   the second exchanging portion receives the coolant from the second coolant outlet of which temperature is higher than that of the coolant flowing into the first exchanging portion.   
     
     
         11 . An air-conditioning system according to  claim 10 , wherein
 the second exchanging portion is arranged downstream of the first exchanging portion.   
     
     
         12 . An air-conditioning system according to  claim 10 , wherein
 the first exchanging portion receives the coolant of which flow rate is greater than that of the coolant which the second exchanging portion receives.