Engine Misfire Detection Apparatus, Hybrid Vehicle Equipped With the Same, and Engine Misfire Detection Method

• US 20100071448A1
• Filed: 11/24/2006
• Published: 03/25/2010
• Est. Priority Date: 01/27/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Akimoto, Hikokazu, Nishigaki, Takahiro
• Granted Patent: US 7,937,992 B2
• Time in Patent Office: Days
• US Class Current: 73/114.40
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/44 related to combustion engines
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2240/507 Operating parameters
• CPC Class Codes: B60L 3/0023 Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2510/06 Combustion engines, Gas turbines
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/06 Combustion engines, Gas turbines
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 41/0225 in relation with the gear ratio or shift lever position
• CPC Class Codes: F02D 41/1498 measuring engine roughness
• CPC Class Codes: F16H 2037/0873 with switching, e.g. to change ranges
• CPC Class Codes: G01M 15/11 by detecting misfire
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

At a Lo gear position of a transmission, the engine misfire detection process of the invention sets a first threshold value A1 and second threshold values to be referred to for detection of an engine misfire (steps S220 and S280) and detects an engine misfire based on the settings of the first threshold value A1 and the second threshold values and 360-degree differences Δ360 computed from 30-degree rotation times T30 given as a time required for rotation of a crankshaft by every 30 degrees (steps S230 and S290). At a Hi gear position of the transmission, the engine misfire detection process of the invention sets a first threshold value A2, which is to be smaller than the first threshold value A1, and second threshold values (step S330 and S390) and detects an engine misfire based on the settings of the first threshold value A2 and the second threshold values and the 360-degree differences Δ360 (step S340 and S400). The engine misfire detection process of the invention detects the occurrence of an engine misfire at each gear position of the transmission by taking into account the varying effects of the operating conditions of a motor MG2, the transmission, and a planetary gear mechanism on the crankshaft of the engine.

Claims

1. An engine misfire detection apparatus for detection of a misfire in a multi-cylinder internal combustion engine included in a power output apparatus, where the power output apparatus includes the multi-cylinder internal combustion engine having a crankshaft mechanically linked with a driveshaft, a motor that outputs power to the driveshaft, and a transmission mechanism that transmits power between a rotating shaft of the motor and the driveshaft with a change in gear position,

the engine misfire detection apparatus comprising:

a rotational position detection unit that detects a rotational position of the crankshaft of the internal combustion engine;

a unit angle rotation time computation module that computes a unit angle rotation time required for rotation of an output shaft of the internal combustion engine by every predetermined unit rotation angle according to the detected rotational position;

a threshold value setting module that sets a first threshold value and a second threshold value to be used for detection of an engine misfire according to a gear position of the transmission mechanism; and

an engine misfire detection module that performs an engine misfire detection, the engine misfire detection making a tentative decision on an engine misfire when any of the computed unit angle rotation times is greater than the first threshold value,

after the tentative decision on the engine misfire, the engine misfire detection specifying an object unit angle rotation time that is greater than the first threshold value among the computed unit angle rotation times and making a final decision on the engine misfire when a ratio of a unit angle rotation time of a different cylinder, which is different from a target cylinder corresponding to the specified object unit angle rotation time, to the specified object unit angle rotation time is in a range defined by the second threshold value.

2. The engine misfire detection apparatus in accordance with claim 1, wherein the threshold value setting module sets a smaller value to the specific threshold value at a higher gear position of the transmission mechanism.

3. The engine misfire detection apparatus in accordance with claim 1, wherein the threshold value setting module sets the specific threshold value to decrease with an increase in rotation speed of the internal combustion engine.

5. The engine misfire detection apparatus in accordance with claim 1, wherein when a rotation speed of the internal combustion engine is out of a predetermined range, the threshold value setting module sets an identical value to the first threshold value used for detection of an engine misfire in a preset first misfire pattern and to the first threshold value used for detection of an engine misfire in a preset second misfire pattern, and

when the rotation speed of the internal combustion engine is within the predetermined range, the threshold value setting module sets different values to the first threshold value used for detection of the engine misfire in the preset first misfire pattern and to the first threshold value used for detection of the engine misfire in the preset second misfire pattern, and

the engine misfire detection module detects the engine misfire in the preset first misfire pattern based on the computed unit angle rotation times and the set first threshold value used for detection of the engine misfire in the preset first misfire pattern, while detecting the engine misfire in the preset second misfire pattern based on the computed unit angle rotation times and the set first threshold value used for detection of the engine misfire in the preset second misfire pattern.

6. The engine misfire detection apparatus in accordance with claim 1, wherein the threshold value setting module sets a first threshold value for a single misfire used for detection of an engine misfire in a single misfire pattern where only one cylinder among the multiple cylinders is misfired as the first threshold value used for detection of the engine misfire in the preset first misfire pattern, and

the threshold value setting module sets a first threshold value for consecutive misfires used for detection of an engine misfire in a consecutive misfire pattern where two consecutive cylinders among the multiple cylinders are misfired as the first threshold value used for detection of the engine misfire in the preset second misfire pattern.

7. The engine misfire detection apparatus in accordance with claim 1, wherein the power output apparatus further includes:

a three shaft-type power input output mechanism that is linked to three shafts, an output shaft of the internal combustion engine, the driveshaft, and a third shaft, and inputs and outputs power from and to a residual one shaft based on powers input from and output to any two shafts among the three shafts; and

a generator that inputs and outputs power from and to the third shaft.

8. A hybrid vehicle equipped with a power output apparatus and with an engine misfire detection apparatus in accordance with claim 1 for detection of a misfire in a multi-cylinder internal combustion engine included in the power output apparatus, where the power output apparatus includes:

the multi-cylinder internal combustion engine having a crankshaft mechanically linked with a driveshaft;

a motor that outputs power to the driveshaft; and

a transmission mechanism that transmits power between a rotating shaft of the motor and the driveshaft with a change in gear position.

4. (canceled)

9. An engine misfire detection method for detecting a misfire in a multi-cylinder internal combustion engine included in a power output apparatus, where the power output apparatus includes the multi-cylinder internal combustion engine having a crankshaft mechanically linked with a driveshaft, a motor that outputs power to the driveshaft, and a transmission mechanism that transmits power between a rotating shaft of the motor and the driveshaft with a change in gear position,

the engine misfire detection method comprising:

detecting a rotational position of the crankshaft of the internal combustion engine;

computing a unit angle rotation time required for rotation of an output shaft of the internal combustion engine by every predetermined unit rotation angle according to the detected rotational position;

setting a first threshold value and a second threshold value to be used for detection of an engine misfire according to a gear position of the transmission mechanism; and

performing an engine misfire detection, where the engine misfire detection makes a tentative decision on an engine misfire when any of the computed unit angle rotation times is greater than the first threshold value,

after the tentative decision on the engine misfire, the engine misfire detection specifies an object unit angle rotation time that is greater than the first threshold value among the computed unit angle rotation times and makes a final decision on the engine misfire when a ratio of a unit angle rotation time of a different cylinder, which is different from a target cylinder corresponding to the specified object unit angle rotation time, to the specified object unit angle rotation time is in a range defined by the second threshold value.