Cooling device for vehicle
First Claim
1. A cooling apparatus for a vehicle, the cooling apparatus including a first coolant circuit in which coolant circulates through an engine and a second coolant circuit in which coolant circulates without passing through the engine, the cooling apparatus comprising:
- a valve that, when closed, decreases or zeroes out the flow rate of the coolant in the first coolant circuit that passes through the engine, and, when open, the valve mixes the coolant in the first coolant circuit and the coolant in the second coolant circuit;
a valve control section for closing the valve when the temperature of the coolant in the first coolant circuit is less than a half-warm-up determination value set to a value lower than a determination value for warm-up completion of the engine, the valve control section opening the valve when the temperature of the coolant in the first coolant circuit increases to the half-warm-up determination value or higher; and
a determining section, wherein, when the temperature of the coolant in the first coolant circuit is greater than or equal to the half-warm-up determination value, the determining section determines that a closed valve failure has occurred in the valve if the difference between the temperature of the coolant in the first coolant circuit and the temperature of the coolant in the second coolant circuit is greater than a failure determination value.
1 Assignment
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Accused Products
Abstract
When the temperature of coolant in an engine is greater than or equal to a half-warm-up determination value, an engine cooling control section opens a valve to mix the coolant in two coolant circuits. Accordingly, even if the temperature of the coolant in the engine fluctuates due to mixing coolants at different temperatures, such fluctuation occurs in a temperature range lower than the determination value for the warm-up completion of the engine. This prevents a control procedure for the time before the warm-up completion and a control procedure for the time after such completion from being performed in a repeating, alternating manner. As a result, when the coolant circulating in the first coolant circuit and the coolant circulating in the second coolant circuit are mixed together, control that should be performed based on the coolant temperature in the engine is carried out without hindrance.
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Citations
10 Claims
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1. A cooling apparatus for a vehicle, the cooling apparatus including a first coolant circuit in which coolant circulates through an engine and a second coolant circuit in which coolant circulates without passing through the engine, the cooling apparatus comprising:
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a valve that, when closed, decreases or zeroes out the flow rate of the coolant in the first coolant circuit that passes through the engine, and, when open, the valve mixes the coolant in the first coolant circuit and the coolant in the second coolant circuit; a valve control section for closing the valve when the temperature of the coolant in the first coolant circuit is less than a half-warm-up determination value set to a value lower than a determination value for warm-up completion of the engine, the valve control section opening the valve when the temperature of the coolant in the first coolant circuit increases to the half-warm-up determination value or higher; and a determining section, wherein, when the temperature of the coolant in the first coolant circuit is greater than or equal to the half-warm-up determination value, the determining section determines that a closed valve failure has occurred in the valve if the difference between the temperature of the coolant in the first coolant circuit and the temperature of the coolant in the second coolant circuit is greater than a failure determination value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A cooling apparatus for a vehicle, the cooling apparatus including a first coolant circuit in which coolant circulates through an engine and a second coolant circuit in which coolant circulates without passing through the engine, the cooling apparatus comprising:
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a valve that, when closed, decreases or zeroes out the flow rate of the coolant in the first coolant circuit that passes through the engine, and, when open, the valve mixes the coolant in the first coolant circuit and the coolant in the second coolant circuit; a first coolant temperature sensor for detecting the temperature of the coolant in the first coolant circuit; a second coolant temperature sensor for detecting the temperature of the coolant in the second coolant circuit; and a valve control section for closing the valve when the temperature of the coolant in the first coolant circuit is less than a half-warm-up determination value set to a value lower than a determination value for warm-up completion of the engine, the valve control section opening the valve when the temperature of the coolant in the first coolant circuit increases to the half-warm-up determination value or higher, wherein, if a failure has occurred in one of the first coolant temperature sensor and the second coolant temperature sensor, the valve control section opens the valve to mix the coolant in the first coolant circuit with the coolant in the second coolant circuit.
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10. A cooling apparatus for a vehicle, the cooling apparatus including a first coolant circuit in which coolant circulates through an engine and a second coolant circuit in which coolant circulates without passing through the engine, the cooling apparatus comprising:
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a valve that, when closed, decreases or zeroes out the flow rate of the coolant in the first coolant circuit that passes through the engine, and, when open, the valve mixes the coolant in the first coolant circuit and the coolant in the second coolant circuit; a coolant temperature sensor for detecting the temperature of the coolant in one of the first coolant circuit and the second coolant circuit; a coolant temperature estimating section for estimating the temperature of the coolant in the other one of the first coolant circuit and the second coolant circuit; and a valve control section for closing the valve when the temperature of the coolant in the first coolant circuit is less than a half-warm-up determination value set to a value lower than a determination value for warm-up completion of the engine, the valve control section opening the valve when the temperature of the coolant in the first coolant circuit increases to the half-warm-up determination value or higher, wherein, if a failure has occurred in the coolant temperature sensor, the valve control section opens the valve to mix the coolant in the first coolant circuit and the coolant in the second coolant circuit.
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Specification