Cooling apparatus for liquid-cooled internal combustion engine
AssigneeDenso Corporation
InventorsKazutaka Suzuki, Eizou Takahashi
Life of this patent
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Abstract
A flow rate ratio of a radiator flow rate to a bypass flow rate is determined from pump water temperature, bypass water temperature and radiator water temperature. The relation between the flow rate ratio and a valve opening degree of a flow control valve is predetermined as a map. The valve opening degree is determined from the flow rate ratio and the map. Accordingly, the cooling water temperature at an inlet of a pump is accurately controlled without detecting the flow rate of the cooling water.
Claims10
A cooling apparatus for a liquid-cooled internal combustion engine using a coolant, comprising:
- a radiator for cooling the coolant circulating between the liquid-cooled internal combustion engine and said radiator;
- a bypass passage for introducing the flowing from the liquid-cooled internal combustion engine to an outlet side of said radiator directly to bypass said radiator;
- a flow control valve having a bypass side inlet through which the coolant having passed through said bypass passage flows in, and a radiator side inlet through which the coolant having passed through said radiator flows in, and an outlet for discharging the coolant to the engine, for controlling a flow rate of the coolant passing through said bypass passage and the coolant passing through said radiator by changing an opening degree of said flow control valve;
- and
- control means for controlling the opening degree of said flow control valve, wherein
- said control means calculates an actual flow rate based on a first temperature of the coolant flowing out of said flow control valve, a second temperature of the coolant flowing through said bypass passage, and a third temperature of the coolant flowing out of said radiator;
- said control means calculates a target flow rate based on a target coolant temperature, the second temperature of the coolant flowing through said bypass passage, and the third temperature of the coolant flowing out of said radiator;
- and
- said control means controls the opening degree of said flow control valve based on the actual flow rate and the target flow rate.
A cooling apparatus for a liquid-cooled internal combustion engine using a coolant, comprising:
- a radiator for cooling the coolant circulating between the liquid-cooled internal combustion engine and said radiator;
- a bypass passage for introducing the flowing from the liquid-cooled internal combustion engine to an outlet side of said radiator directly to bypass said radiator;
- a flow control valve for controlling a flow rate of the coolant passing through said bypass passage and the coolant passing through said radiator by changing an opening degree of said flow control valve;
- and
- control means for controlling the opening degree of said flow control valve;
- wherein:
- said control means calculates an actual flow rate based on a first temperature of the coolant flowing out of said flow control valve, a second temperature of the coolant flowing flowing through said bypass passage, and a third temperature of the coolant flowing out of said radiator;
- the first temperature is determined by the mixture of the coolant flowing through said bypass passage and the coolant flowing through said radiator;
- said control means calculates a target flow rate based on a target coolant temperature, the second temperature of the coolant flowing through said bypass passage, and the third temperature of the coolant flowing out of said radiator;
- and
- said control means controls the opening degreee of said flow control valve based on the actual flow rate and the target flow rate.
Dependencies are inferred from the claim text.