Patent ID: 9470138
Filing Date: 2016-10-18
CPC Classification: F01P

Claim Text:
1. A coolant circulation system for an engine that includes a cylinder block portion and a cylinder head portion, the coolant circulation system comprising: a cylinder block passage provided in the cylinder block portion to serve as a passage through which a coolant flows to cool the cylinder block portion, a cylinder head passage provided in the cylinder head portion to serve as a passage through which the coolant flows to cool the cylinder head portion, wherein the cylinder block passage and the cylinder head passage are connected in parallel to each other; a first heat exchanger connected to an outlet of the cylinder block passage without being connected to an outlet of the cylinder head passage; a second heat exchanger connected to the outlet of the cylinder head passage without being connected to the outlet of the cylinder block passage; a radiator connected to both the outlet of the cylinder block passage and the outlet of the cylinder head passage, such that coolant from the outlet of the cylinder block passage and the outlet of the cylinder head passage flows through the radiator before returning to the cylinder block passage or the cylinder head passage; a control valve unit including a first control valve that controls a flow rate of the coolant flowing through the cylinder block passage, and a second control valve that controls a flow rate of the coolant flowing through the cylinder head passage, the control valve unit being capable of controlling the flow rate of the coolant flowing through the cylinder block passage and the flow rate of the coolant flowing through the cylinder head passage respectively, wherein the radiator is configured to be connected to both the outlet of the cylinder block passage and the outlet of the cylinder head passage when the first heat exchanger is connected to the outlet of the cylinder block passage without being connected to the outlet of the cylinder head passage and when the second heat exchanger is connected to the outlet of the cylinder head passage without being connected to the outlet of the cylinder block passage.