Cooling system for engine

A cooling system for an engine, comprising:

• coolant flow paths including a first flow path and a second flow path where coolant circulates, the first flow path passing through a cylinder head of the engine, the second flow path branching from the first flow path and passing through an auxiliary machinery of the engine;
• a coolant pump for circulating the coolant within the coolant flow paths;
• a flow rate control valve for adjusting a flow rate of the coolant through the second flow path;
• a temperature detector for detecting a temperature of the coolant within the first flow path;
• a valve controller for adjusting an opening of the flow rate control valve based on the temperature detected by the temperature detector;
• and an output level determiner for determining an output level of the engine based on at least one of a fuel injection amount for the engine and an engine speed, wherein the valve controller fully closes the flow rate control valve in a case where the detected temperature is below a predetermined temperature threshold and the determined output level is one of a reference output level and a value therebelow, and the valve controller opens the flow rate control valve in one of a case where the detected temperature is below the predetermined temperature threshold and the determined output level exceeds the reference output level, and a case where the detected temperature is one of the predetermined temperature threshold and a value thereabove, wherein the valve controller fully opens the flow rate control valve in the case where the detected temperature is below the predetermined temperature threshold and the determined output level exceeds the reference output level, and wherein the output level determiner has an output level map in which ranges of the output level are defined based on parameters, and the output level determiner determines the output level by referring to the output level map, the parameters being the fuel injection amount for the engine and the engine speed.

A cooling system for an engine, comprising:

• coolant flow paths including a first flow path and a second flow path where coolant circulates, the first flow path passing through a cylinder head of the engine, the second flow path branching from the first flow path and passing through an auxiliary machinery of the engine;
• a coolant pump for circulating the coolant within the coolant flow paths;
• a flow rate control valve for adjusting a flow rate of the coolant through the second flow path;
• a temperature detector for detecting a temperature of the coolant within the first flow path;
• a valve controller for adjusting an opening of the flow rate control valve based on the temperature detected by the temperature detector;
• and an output level determiner for determining an output level of the engine based on at least one of a fuel injection amount for the engine and an engine speed, wherein the valve controller fully closes the flow rate control valve in a case where the detected temperature is below a predetermined temperature threshold and the determined output level is one of a reference output level and a value therebelow, and the valve controller opens the flow rate control valve in one of a case where the detected temperature is below the predetermined temperature threshold and the determined output level exceeds the reference output level, and a case where the detected temperature is one of the predetermined temperature threshold and a value thereabove, wherein the coolant flow paths also include a third flow path passing through a cylinder block of the engine, wherein the flow rate control valve adjusts the flow rate of the coolant through the second and third flow paths, and wherein the valve controller fully closes the flow rate control valve to the third flow path in one of the case where the detected temperature is below the predetermined temperature threshold and the determined output level is one of the reference output level and the value therebelow, and a case where the detected temperature is below the predetermined temperature threshold and the determined output level is within a range exceeding the reference output level and below a predetermined output level that is above the reference output level, and the valve controller opens the flow rate control valve to the third flow path in one of a case where the detected temperature is below the predetermined temperature threshold and the determined output level is one of the predetermined output level and a value thereabove, and the case where the detected temperature is one of the predetermined temperature threshold and the value thereabove.