Start up fuel control device for an engine
First Claim
1. A start up fuel control device, for an internal combustion engine having cylinders, comprising:
- start up determining means for determining whether the engine has started;
residual fuel amount calculating means for calculating a residual fuel amount parameter relating to the amount of fuel remaining in the cylinders of the engine during a start up operation of the engine;
memory means for memorizing the latest value of said residual fuel amount parameter from the beginning of the start up operation of the engine until the start up determining means determines that the engine has started, regardless of whether a main switch of the engine is turned on or turned off;
scavenging means for initiating a scavenging operation of the engine in which a fuel supply amount to the engine is reduced when the value of said residual fuel amount parameter memorized in the memory means becomes larger than a predetermined first value;
a scavenged fuel amount calculating means for calculating a scavenged fuel amount parameter relating to the amount of fuel expelled from the cylinders since the scavenging operation of the engine started; and
restoring means for increasing the fuel supply amount to the engine when the value of said scavenged fuel amount parameter becomes larger than a predetermined second value until the fuel supply amount reaches a fuel supply amount before the scavenging operation started.
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Accused Products
Abstract
The start up fuel control device according to the present invention controls the fuel supply amount to an engine during the cranking operation. After the cranking operation starts, the device measures the time lapsed since the cranking operation started. Further, the measured time is stored in a backup RAM which can preserve the content of its memory even if a main switch of the engine is turned off. Since the time lapsed from the beginning of the cranking operation (cranking time) can be considered as a parameter representing the amount of unburnt fuel remaining in the cylinder, the device performs the following operation based on the cranking time to prevent the air-fuel ratio of the air-fuel mixture in the cylinders becomes too low (rich) for firing to occur. When the cranking time exceeds a predetermined period, the device starts a scavenging operation in which the fuel supplied to the engine is reduced in order to expel the fuel remaining in the cylinders by the cranking operation. After performing the scavenging operation for a predetermined period, the device increases the fuel supplied to the engine until it reverts to the value before the scavenging operation started.
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Citations
15 Claims
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1. A start up fuel control device, for an internal combustion engine having cylinders, comprising:
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start up determining means for determining whether the engine has started; residual fuel amount calculating means for calculating a residual fuel amount parameter relating to the amount of fuel remaining in the cylinders of the engine during a start up operation of the engine; memory means for memorizing the latest value of said residual fuel amount parameter from the beginning of the start up operation of the engine until the start up determining means determines that the engine has started, regardless of whether a main switch of the engine is turned on or turned off; scavenging means for initiating a scavenging operation of the engine in which a fuel supply amount to the engine is reduced when the value of said residual fuel amount parameter memorized in the memory means becomes larger than a predetermined first value; a scavenged fuel amount calculating means for calculating a scavenged fuel amount parameter relating to the amount of fuel expelled from the cylinders since the scavenging operation of the engine started; and restoring means for increasing the fuel supply amount to the engine when the value of said scavenged fuel amount parameter becomes larger than a predetermined second value until the fuel supply amount reaches a fuel supply amount before the scavenging operation started. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification