Method and code for controlling temperature of engine component associated with deactivatable cylinder
First Claim
1. A method of controlling a temperature of a component of an internal combustion engine associated with a deactivatable cylinder after the engine is switched from a first operating mode characterized by an activation of the cylinder to a second operating mode characterized by a deactivation of the cylinder, the method comprising:
- determining, during the second operating mode, a first measure representative of a component heat loss by determining a first value representing a first engine operating parameter, and accumulating in the first values when operating the engine in the second operating mode; and
switching from the second operating mode back to the first operating mode by reactivating the cylinder when the first measure exceeds a first threshold value.
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Accused Products
Abstract
A method for controlling the operation of a deactivatable valve lifter of an internal combustion engine includes determining a first measure of heat loss from one or more components associated with a given deactivated cylinder based, for example, on the number of engine cycles that have occurred since cylinder deactivation. The given cylinder is reactivated when the component heat loss measure reaches a threshold level, as by comparing the first measure to a first predetermined threshold value. After cylinder reactivation, the given cylinder can thereafter be deactivated only after the temperature of the components has been restored to a nominal operating temperature, for example, as inferred from a second measure, representing the heat generated within the given cylinder subsequent to cylinder reactivation, determined based upon engine mass air flow or fuel flow. In this manner, the respective temperatures of such engine components are maintained above a desired minimum temperature.
63 Citations
19 Claims
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1. A method of controlling a temperature of a component of an internal combustion engine associated with a deactivatable cylinder after the engine is switched from a first operating mode characterized by an activation of the cylinder to a second operating mode characterized by a deactivation of the cylinder, the method comprising:
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determining, during the second operating mode, a first measure representative of a component heat loss by determining a first value representing a first engine operating parameter, and accumulating in the first values when operating the engine in the second operating mode; and switching from the second operating mode back to the first operating mode by reactivating the cylinder when the first measure exceeds a first threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of controlling an internal combustion engine adapted to operate in a cylinder-deactivation mode, the cylinder-deactivation mode being characterized in that each intake and exhaust valve associated with a given deactivated cylinder is maintained in a respective closed position, the method comprising:
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determining, while operating the engine in the cylinder-deactivation mode, a first measure representative of a heat loss within the given cylinder since a deactivation of the given cylinder; and discontinuing the cylinder-deactivation mode when the first measure exceeds a first threshold value based on at least one of the group consisting of an engine speed, an engine load indicator, an intake manifold pressure, an air-fuel charge temperature, an ambient air temperature, and an engine coolant temperature. - View Dependent Claims (11, 12, 13, 14)
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15. A computer-readable storage medium including computer executable code for controlling an internal combustion engine adapted to operate in a cylinder-deactivation mode, the cylinder-deactivation mode being characterized in that each intake and exhaust valve associated with a given deactivated cylinder is maintained in a respective closed position, the storage medium including:
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code for determining a first measure representative of a heat loss within the given cylinder while operating the engine in the cylinder-deactivation mode; code for discontinuing the cylinder-deactivation mode when the first measure exceeds a first threshold value; and code for determining the first threshold value based on at least one of the group consisting of one of the group consisting of an engine speed, an engine load indicator, an intake manifold pressure, an air-fuel charge temperature, an ambient air temperature, and an engine coolant temperature. - View Dependent Claims (16, 17, 18, 19)
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Specification