Engine cooling system
First Claim
1. An engine cooling system, comprising:
- a coolant circuit extending through an engine, wherein coolant flows through the coolant circuit;
a radiator provided in the coolant circuit, wherein the radiator cools coolant passing through the coolant circuit;
a flow control valve, which regulates the flow rate of coolant flowing through the radiator; and
a controller, wherein the controller controls the opening size of the flow control valve only during feedback control such that an engine coolant temperature, which is the temperature of coolant passing through the engine, seeks a predetermined target value, wherein, during feedback control, the controller controls the flow control valve such that the opening size of the flow control valve remains above a predetermined lowest value.
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Accused Products
Abstract
An engine cooling system includes a flow control valve and an electronic control unit (ECU) for controlling the flow control valve. The flow control valve regulates the flow rate of coolant flowing through a radiator in a coolant circuit. The ECU feedback controls the opening size of the flow control valve such that the temperature of coolant at an engine outlet seeks a predetermined target value. During the feedback control, the ECU controls the flow control valve such that the opening size of the flow control valve remains above a predetermined lowest value. As a result, the flow control valve is prevented from falling in a small opening size range in which in which it is difficult to cause the engine outlet coolant temperature to seek the target value, and the engine outlet coolant temperature is favorably adjusted.
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Citations
19 Claims
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1. An engine cooling system, comprising:
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a coolant circuit extending through an engine, wherein coolant flows through the coolant circuit;
a radiator provided in the coolant circuit, wherein the radiator cools coolant passing through the coolant circuit;
a flow control valve, which regulates the flow rate of coolant flowing through the radiator; and
a controller, wherein the controller controls the opening size of the flow control valve only during feedback control such that an engine coolant temperature, which is the temperature of coolant passing through the engine, seeks a predetermined target value, wherein, during feedback control, the controller controls the flow control valve such that the opening size of the flow control valve remains above a predetermined lowest value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An engine cooling system, comprising:
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a coolant circuit extending through an engine, wherein coolant flows through the coolant circuit;
a radiator provided in the coolant circuit, wherein the radiator cools coolant passing through the coolant circuit;
a flow control valve, which regulates the flow rate of coolant flowing through the radiator; and
a controller, wherein the controller controls the opening size of the flow control valve only during feedback control such that an engine coolant temperature, which is the temperature of coolant passing through the engine, seeks a predetermined target value, wherein the flow control valve has a specific small opening size range in which it is difficult to cause the engine coolant temperature to seek the target value during feedback control, and wherein, during feedback control, the controller limits the moving range of the flow control valve to prevent the flow control valve from falling in the small opening size range.
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13. An engine cooling system, comprising:
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a coolant circuit extending through an engine, wherein coolant flows through the coolant circuit;
a radiator provided in the coolant circuit, wherein the radiator cools coolant passing through the coolant circuit;
a flow control valve, which regulates the flow rate of coolant flowing through the radiator; and
a controller, wherein feedback from the controller controls the opening size of the flow control valve such that an engine coolant temperature, which is the temperature of coolant passing through the engine, seeks a predetermined target value, wherein, when the engine coolant temperature shifts from increasing to decreasing during feedback control, the controller decreases the opening size of the flow control valve by a predetermined amount from the current opening size, and wherein, when the engine coolant temperature shifts from decreasing to increasing during feedback control, the controller increases the opening size of the flow control valve by a predetermined amount from the current opening size. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification