MISFIRE DETERMINATION DEVICE AND MISFIRE DETERMINATION METHOD FOR INTERNAL COMBUSTION ENGINE
First Claim
1. A misfire determination device for an internal combustion engine that is coupled to a transmission via a hydraulic power transmission equipped with a lock-up clutch, wherein the misfire determination device determines that there is a possibility that a misfire has occurred when a rotation fluctuation amount of the internal combustion engine exceeds a predetermined threshold, and makes a misfire determination by determining whether a rotation fluctuation pattern of the internal combustion engine is a pattern specific to occurrence of a misfire, the misfire determination device comprising:
- a first misfire determination unit that makes a first misfire determination in which a misfire determination is made on the basis of whether, when the lock-up clutch is in a non-lock-up state, the rotation fluctuation pattern of the internal combustion engine substantially coincides with a first rotation fluctuation pattern specific to occurrence of a misfire in the non-lock-up state; and
a second misfire determination unit that makes a second misfire determination in which occurrence of a misfire is determined on the basis of whether, when the lock-up clutch is in a lock-up state, the rotation fluctuation pattern of the internal combustion engine substantially coincides with a second rotation fluctuation pattern specific to occurrence of a misfire in the lock-up state.
1 Assignment
0 Petitions
Accused Products
Abstract
When a rotation fluctuation amount of an engine exceeds a predetermined threshold, it is determined that there is a possibility that a misfire has occurred. Then, when a rotation fluctuation pattern of the engine coincides with a first rotation fluctuation pattern, it is determined that a misfire has occurred; whereas, when the rotation fluctuation pattern does not coincide with the first rotation fluctuation pattern, it is determined whether the rotation fluctuation pattern coincides with a specific rotation fluctuation pattern in consideration of a lock-up state of a lock-up clutch or whether an engine rotational speed is lower than a threshold. When the determination is affirmative, occurrence of a misfire is determined on the basis of whether the rotation fluctuation pattern of the engine coincides with a second misfire determination pattern that is defined to be smaller in variation of a rotation fluctuation amount than the first rotation fluctuation pattern.
18 Citations
25 Claims
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1. A misfire determination device for an internal combustion engine that is coupled to a transmission via a hydraulic power transmission equipped with a lock-up clutch, wherein the misfire determination device determines that there is a possibility that a misfire has occurred when a rotation fluctuation amount of the internal combustion engine exceeds a predetermined threshold, and makes a misfire determination by determining whether a rotation fluctuation pattern of the internal combustion engine is a pattern specific to occurrence of a misfire, the misfire determination device comprising:
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a first misfire determination unit that makes a first misfire determination in which a misfire determination is made on the basis of whether, when the lock-up clutch is in a non-lock-up state, the rotation fluctuation pattern of the internal combustion engine substantially coincides with a first rotation fluctuation pattern specific to occurrence of a misfire in the non-lock-up state; and a second misfire determination unit that makes a second misfire determination in which occurrence of a misfire is determined on the basis of whether, when the lock-up clutch is in a lock-up state, the rotation fluctuation pattern of the internal combustion engine substantially coincides with a second rotation fluctuation pattern specific to occurrence of a misfire in the lock-up state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A misfire determination device for an internal combustion engine that is coupled to a transmission via a hydraulic power transmission equipped with a lock-up clutch, wherein the misfire determination device determines that there is a possibility that a misfire has occurred when a rotation fluctuation amount of the internal combustion engine exceeds a predetermined threshold, and makes a misfire determination by determining whether a rotation fluctuation pattern of the internal combustion engine is a pattern specific to occurrence of a misfire, the misfire determination device comprising:
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a first misfire determination unit that calculates a rotation fluctuation amount from a difference between an engine rotational speed in an expansion stroke of a misfire determination target cylinder for which it is determined that there is a possibility that the misfire has occurred and an engine rotational speed in an expansion stroke of another cylinder, and then makes a first misfire determination in which occurrence of a misfire is determined on the basis of whether a variation pattern of the rotation fluctuation amount substantially coincides with a predetermined misfire determination pattern; an engine rotational speed determination unit that, when it is not determined that a misfire has occurred in the first misfire determination made by the first misfire determination unit, makes an engine rotational speed determination in which it is determined whether an engine rotational speed in the expansion stroke of the misfire determination target cylinder when the lock-up clutch is in the lock-up state is lower than a predetermined threshold; and a second misfire determination unit that, when it is determined in the engine rotational speed determination made by the engine rotational speed determination unit that the engine rotational speed in the expansion stroke of the misfire determination target cylinder is lower than the predetermined threshold, makes a second misfire determination in which it is determined whether a misfire has occurred on the basis of the difference between the engine rotational speed in the expansion stroke of the misfire determination target cylinder and the engine rotational speed in the expansion stroke of the another cylinder. - View Dependent Claims (17, 18, 19, 20, 21)
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22. A misfire determination method for an internal combustion engine that is coupled to a transmission via a hydraulic power transmission equipped with a lock-up clutch, wherein the misfire determination method determines that there is a possibility that a misfire has occurred when a rotation fluctuation amount of the internal combustion engine exceeds a predetermined threshold, and makes a misfire determination by determining whether a rotation fluctuation pattern of the internal combustion engine is a pattern specific to occurrence of a misfire, the misfire determination method comprising:
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making a first misfire determination in which a misfire determination is made on the basis of whether, when the lock-up clutch is in a non-lock-up state, the rotation fluctuation pattern of the internal combustion engine substantially coincides with a first rotation fluctuation pattern specific to occurrence of a misfire in the non-lock-up state; and making a second misfire determination in which a misfire determination is made on the basis of whether, when the lock-up clutch is in a lock-up state, the rotation fluctuation pattern of the internal combustion engine substantially coincides with a second rotation fluctuation pattern specific to occurrence of a misfire in the lock-up state. - View Dependent Claims (23, 24)
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25. A misfire determination method for an internal combustion engine that is coupled to a transmission via a hydraulic power transmission equipped with a lock-up clutch, wherein the misfire determination method determines that there is a possibility that a misfire has occurred when a rotation fluctuation amount of the internal combustion engine exceeds a predetermined threshold, and makes a misfire determination by determining whether a rotation fluctuation pattern of the internal combustion engine is a pattern specific to occurrence of a misfire, the misfire determination method comprising:
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calculating a rotation fluctuation amount from a difference between an engine rotational speed in an expansion stroke of a misfire determination target cylinder for which it is determined that there is a possibility that the misfire has occurred and an engine rotational speed in an expansion stroke of another cylinder, and then making a first misfire determination in which occurrence of a misfire is determined on the basis of whether a variation pattern of the rotation fluctuation amount substantially coincides with a predetermined misfire determination pattern; when it is not determined that a misfire has occurred in the first misfire determination, making an engine rotational speed determination in which it is determined whether an engine rotational speed in the expansion stroke of the misfire determination target cylinder when the lock-up clutch is in the lock-up state is lower than a predetermined threshold; and when it is determined in the engine rotational speed determination that the engine rotational speed in the expansion stroke of the misfire determination target cylinder is lower than the predetermined threshold, making a second misfire determination in which it is determined whether a misfire has occurred on the basis of the difference between the engine rotational speed in the expansion stroke of the misfire determination target cylinder and the engine rotational speed in the expansion stroke of the another cylinder.
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Specification