COOLING DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

High temperature (HT) and low temperature (LT) cooling water, the LT cooling water being at a lower temperature than the HT cooling water, circulate in HT and LT cooling water flows in respective channels. A controller controls to set the temperature of the LT cooling water lower in a case where an operating point of an engine lies in a particular region in an operational region of the engine, the particular region including a region in which the load is high and the engine speed is low, than in a case where the operating point lies in an operational region other than the particular region. Furthermore, the controller narrows the particular region in a direction toward higher loads in a case where the temperature of the HT cooling water is lower than a predetermined temperature.

主权项

1. A cooling device for an internal combustion engine, comprising:
a first cooling water flow channel formed in a main unit of the internal combustion engine; an intake air cooling device of a water cooling type that cools an intake air; a first cooling water circulating system to make a first cooling water circulate in the first cooling water flow channel; a second cooling water circulating system that is separate from the first cooling water circulating system and is to make a second cooling water at a lower temperature than the first cooling water circulate through the intake air cooling device; and a controller that is configured to control operation of the second cooling water circulating system in accordance with a load and an engine speed of the internal combustion engine and a temperature of the first cooling water, wherein the controller is configured to control operation of the second cooling water circulating system so as to set the temperature of the second cooling water lower in a case where an operating point of the internal combustion engine, that is defined by the load and the engine speed, lies in a particular region in an operational region of the internal combustion engine, the particular region including a region in which the load is high and the engine speed is low, than in a case where the operating point lies outside of the particular region, and narrow the particular region in a direction toward higher loads in a case where the temperature of the first cooling water is lower than a predetermined temperature compared with a case where the temperature of the first cooling water is higher than the predetermined temperature.