| 摘要 |
Disclosed is an engine cooling system which comprises: a head-side circulation pathway through which coolant from a water pump is circulated via a water jacket of a cylinder head and an EGR cooler; a block-side circulation pathway through which the coolant from the water pump is circulated via a water jacket of a cylinder block; and a switching valve unit operable, during cold operation of the engine, to pass the coolant from the water pump, along the head-side circulation pathway, and, when a temperature of the engine is raised up to a predetermined value, to pass the coolant from the water pump, along not only the head-side circulation pathway but also the block-side circulation pathway. |
| 主权项 |
1. A system for cooling an engine, the engine comprising a cylinder block, a cylinder head, an intake passage, an exhaust passage, an EGR passage connecting the exhaust passage to the intake passage to recirculate a part of exhaust gas to the intake passage therethrough, an EGR cooler for performing heat exchange between exhaust gas in the EGR passage and coolant, and a radiator for cooling the coolant, each of the cylinder block and the cylinder head being provided with a water jacket through which the coolant flows, the system comprising:
a water pump for discharging the coolant; a head-side circulation pathway through which the coolant from the water pump is circulated via the water jacket of the cylinder head and the EGR cooler while bypassing the radiator; a block-side circulation pathway through which the coolant from the water pump is circulated via the water jacket of the cylinder block while bypassing the radiator; and a switching valve unit operable, when a temperature of the engine is lower than a predetermined value which is lower than a warm-up completion temperature, to pass the coolant from the water pump, along the head-side circulation pathway, and, when the temperature of the engine is equal to or higher than the predetermined value and lower than the warm-up completion temperature, to pass the coolant from the water pump, along not only the head-side circulation pathway but also the block-side circulation pathway. |
