JP2009281186A - Device for determining misfire of internal combustion engine, vehicle, and method for determining misfire of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine misfire of one cylinder with one cylinder of a plurality of cylinders of an internal combustion engine continuously misfiring even if resonance caused by torsion of a torsion element occurs, and to suppress erroneous specifying a non-misfiring cylinder as a misfiring cylinder when the misfire of the one cylinder is determined. <P>SOLUTION: In this device for determining misfire, when the misfire of the one cylinder is determined, if the operation point of the engine does not belong to a resonance area on a rear stage including a damper (S150), the misfiring cylinder is specified by a crank angle CA when determining the misfire of the one cylinder and saved, and also a one cylinder misfire determination flag F is set to a value 1 (S160 to S180). When the misfire of the one cylinder is determined, if the operation point of the engine belongs to the resonance area (S150) and the one cylinder misfire determination flag F is the value 1 (S190), the saved cylinder is specified as the misfiring cylinder (S200). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a misfire determination device for an internal combustion engine, a vehicle, and a misfire determination method for an internal combustion engine, and more particularly, determines misfire of a multi-cylinder internal combustion engine in which an output shaft is connected to a subsequent shaft through a torsion element. The present invention relates to a misfire determination device for an internal combustion engine, a vehicle including the internal combustion engine and a misfire determination device for the internal combustion engine, and a misfire determination method for the internal combustion engine.

Conventionally, as a misfire determination device for this type of internal combustion engine, an engine, a planetary gear mechanism connected to the output shaft of the engine via a torsional element such as a damper and connected to a drive shaft, and a planetary gear mechanism are connected. It is mounted on a vehicle including a motor MG1 and a motor MG2 connected to a drive shaft, and has been proposed to determine engine misfire based on rotational fluctuation at the crank angle position of the engine (for example, a patent) Reference 1).
JP 2007-170248 A

  In a vehicle of the type described above, when a misfire occurs in the engine, resonance occurs based on the twist of the twist element depending on the operating point. When resonance occurs, engine rotation fluctuations may appear small in a misfired cylinder and appear large in a non-misfired cylinder, in which case it is determined that a misfire has occurred in any cylinder of the engine. Although it is possible, it is difficult to identify which cylinder has misfired.

  According to the misfire determination device for an internal combustion engine, the vehicle, and the misfire determination method for the internal combustion engine of the present invention, even when resonance based on torsion of a torsion element is occurring, one cylinder among the plurality of cylinders of the internal combustion engine is continuously provided. The main purpose is to determine misfiring one-cylinder misfire and to prevent a cylinder that has not misfired from being misidentified as a misfiring cylinder when one-cylinder misfire is determined.

  The misfire determination device for an internal combustion engine, the vehicle, and the misfire determination method for the internal combustion engine of the present invention employ the following means in order to achieve the main object described above.

A misfire determination device for an internal combustion engine of the present invention,
A misfire determination device for an internal combustion engine that determines misfire of a multi-cylinder internal combustion engine in which an output shaft is connected to a rear shaft of a rear stage through a torsion element,
Rotational position detecting means for detecting the rotational position of the output shaft of the internal combustion engine;
Rotation fluctuation calculating means for calculating the rotation fluctuation of the internal combustion engine based on the detected rotation position of the output shaft;
One-cylinder misfire determination means for determining one-cylinder misfire in which one cylinder among the plurality of cylinders of the internal combustion engine continuously misfires based on the calculated rotation fluctuation;
Storage means for storing data;
When the internal combustion engine is not operated at an operating point in a resonance generating region where resonance based on torsion of the torsion element is generated, when the one cylinder misfire determination means determines that one cylinder misfire has occurred, it is determined that the one cylinder misfire has occurred. The cylinder corresponding to the rotational position of the output shaft used at the time is specified as a misfiring cylinder and stored in the storage means, and when the internal combustion engine is operated at an operating point in the resonance generating region, Misfire cylinder specifying means for specifying the same cylinder as the stored cylinder as the misfire cylinder when the cylinder misfire determination means determines that one cylinder is misfired;
It is a summary to provide.

  In the misfire determination device for an internal combustion engine of the present invention, the rotational fluctuation of the internal combustion engine is calculated based on the rotational position of the output shaft of the internal combustion engine to which the rear stage shaft is connected via the torsion element, and the calculated rotational fluctuation 1 cylinder misfiring in which one cylinder among the plurality of cylinders of the internal combustion engine continuously misfires is determined, and the internal combustion engine is not operated at an operating point in a resonance generating region where resonance based on torsion of a torsion element occurs When it is determined that one cylinder is misfiring, the cylinder corresponding to the rotational position of the output shaft used when it is determined that one cylinder is misfiring is specified and stored as a misfiring cylinder, and the internal combustion engine is operated at an operating point in the resonance generating region. When it is determined that one cylinder has misfired during operation, the same cylinder as the stored cylinder is identified as the misfire cylinder. Thereby, even when resonance based on torsion of the torsion element is occurring, when one cylinder misfire in which one cylinder among the plurality of cylinders of the internal combustion engine continuously misfires is determined and one cylinder misfire is determined It is possible to prevent the cylinder that has not misfired from being erroneously specified as the misfired cylinder.

The vehicle of the present invention
A multi-cylinder internal combustion engine whose output shaft is connected to the rear shaft of the rear stage via a torsion element;
The misfire determination apparatus for an internal combustion engine of the present invention for determining misfire of the internal combustion engine, that is, the misfire determination apparatus for an internal combustion engine of the present invention basically has an output shaft connected to a subsequent stage shaft via a twist element. A misfire determination apparatus for an internal combustion engine that determines misfire of an internal combustion engine having a plurality of cylinders, wherein the rotational position detection means detects the rotational position of the output shaft of the internal combustion engine, and the detected rotational position of the output shaft. A rotation fluctuation calculating means for calculating a rotation fluctuation of the internal combustion engine based on the one-cylinder misfiring in which one cylinder among the plurality of cylinders of the internal combustion engine continuously misfires based on the calculated rotation fluctuation; Misfire determination means, storage means for storing data, and the one-cylinder misfire determination means when the internal combustion engine is not operated at an operating point in a resonance generating region where resonance based on torsion of the torsion element occurs If one cylinder misfire is determined, the cylinder corresponding to the rotational position of the output shaft used when the one cylinder misfire is determined is specified as the misfire cylinder and stored in the storage means. Misfire cylinder specifying means for specifying the same cylinder as the stored cylinder as the misfire cylinder when the one cylinder misfire determination means determines that one cylinder has misfired when operating at an operation point within the generation region. A misfire determination device for an internal combustion engine,
It is a summary to provide.

  Since the vehicle according to the present invention includes the misfire determination device for an internal combustion engine according to the present invention described above, the internal combustion engine is effective even if there is an effect produced by the misfire determination device for the internal combustion engine according to the present invention, for example, the resonance based on the twist of the twist element. It is possible to determine that one cylinder among a plurality of cylinders of the engine continuously misfires and to prevent a cylinder that has not misfired from being misidentified as a misfiring cylinder when one cylinder misfire is determined. The same effects as those that can be achieved can be achieved.

  In such a vehicle of the present invention, the generator is connected to three axes of the generator capable of inputting / outputting power, the rear shaft, the rotating shaft of the generator, and the rotating shaft on the axle side, and enters any two of the three shafts. A three-shaft power input / output means for inputting / outputting power to / from the remaining one shaft based on the output power and an electric motor capable of inputting / outputting power to the rotating shaft on the axle side may be provided. . The “three-axis power input / output means” includes a planetary gear mechanism and a differential gear.

The misfire determination method for an internal combustion engine of the present invention includes:
A misfire determination method for an internal combustion engine for determining misfire of a multi-cylinder internal combustion engine in which an output shaft is connected to a rear stage shaft through a torsion element,
(A) calculating the rotational fluctuation of the internal combustion engine based on the rotational position of the output shaft;
(B) determining one cylinder misfire in which one cylinder among the plurality of cylinders of the internal combustion engine continuously misfires based on the calculated rotation fluctuation;
(C) When the internal combustion engine is not operated at an operating point in a resonance generating region where resonance based on torsion of the torsion element is generated, and when it is determined that one cylinder misfire occurs in the step (b), the one cylinder misfire The cylinder corresponding to the rotational position of the output shaft used at the time of determination is specified and stored as a misfire cylinder, and the step (b) is performed when the internal combustion engine is operated at an operating point in the resonance generating region. The main point is to specify the same cylinder as the stored cylinder as the misfiring cylinder when it is determined that one cylinder misfires.

  According to the misfire determination method for an internal combustion engine of the present invention, the rotational fluctuation of the internal combustion engine is calculated based on the rotational position of the output shaft of the internal combustion engine to which the rear stage shaft is connected via the torsion element. One cylinder misfire in which one cylinder among the plurality of cylinders of the internal combustion engine continuously misfires is determined based on the rotational fluctuation, and the internal combustion engine is operated at an operation point in a resonance generating region where resonance based on torsion of a torsion element occurs. When it is determined that one cylinder misfire has occurred, the cylinder corresponding to the rotational position of the output shaft used when the one cylinder misfire is determined is specified and stored as the misfire cylinder, and the internal combustion engine is operated within the resonance generation region. When it is determined that one cylinder is misfired while operating at a point, the same cylinder as the stored cylinder is specified as the misfire cylinder. Thereby, even when resonance based on torsion of the torsion element is occurring, when one cylinder misfire in which one cylinder among the plurality of cylinders of the internal combustion engine continuously misfires is determined and one cylinder misfire is determined It is possible to prevent the cylinder that has not misfired from being erroneously specified as the misfired cylinder.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present invention. As shown in the drawing, the hybrid vehicle 20 of the embodiment includes an engine 22 and a three-shaft power distribution and integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28 as a torsion element. The motor MG1 capable of generating electricity connected to the power distribution and integration mechanism 30; the reduction gear 35 attached to the ring gear shaft 32a as the drive shaft connected to the power distribution and integration mechanism 30; and the reduction gear 35 A motor MG2 and a hybrid electronic control unit 70 for controlling the entire vehicle are provided.

  The engine 22 is configured as a 6-cylinder internal combustion engine that can output power using a hydrocarbon-based fuel such as gasoline or light oil. For example, as shown in FIG. The fuel is injected from the fuel injection valve 126 provided for each cylinder, and the intake air and the gasoline are mixed. The mixture is sucked into the fuel chamber through the intake valve 128 and ignited. The reciprocating motion of the piston 132 that is explosively burned by the electric spark generated by the plug 130 and pushed down by the energy is converted into the rotational motion of the crankshaft 26. Exhaust gas from the engine 22 is discharged to the outside air through a purification device (three-way catalyst) 134 that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

  The engine 22 is controlled by an engine electronic control unit (hereinafter referred to as an engine ECU) 24. The engine ECU 24 is configured as a microprocessor centered on the CPU 24a, and includes a ROM 24b that stores a processing program, a RAM 24c that temporarily stores data, an input / output port and a communication port (not shown), in addition to the CPU 24a. . The engine ECU 24 includes signals from various sensors that detect the state of the engine 22, a crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 26, and a water temperature sensor 142 that detects the temperature of cooling water in the engine 22. From the cam position sensor 144 that detects the temperature of the cooling water from the engine, the intake valve 128 that performs intake and exhaust to the combustion chamber, and the rotational position of the camshaft that opens and closes the exhaust valve, and the throttle valve position sensor that detects the position of the throttle valve 124 146, air flow meter signal AF from air flow meter 148 attached to the intake pipe, intake air temperature from temperature sensor 149 also attached to the intake pipe, air-fuel ratio AF from air-fuel ratio sensor 135a, oxygen Such as oxygen signal from capacitors 135b is input via the input port. The engine ECU 24 also integrates various control signals for driving the engine 22, such as a drive signal to the fuel injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, and an igniter. The control signal to the ignition coil 138 and the control signal to the variable valve timing mechanism 150 that can change the opening / closing timing of the intake valve 128 are output via the output port. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and outputs data related to the operation state of the engine 22 as necessary. .

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current to be applied to the motors MG1 and MG2 is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50. Further, the battery ECU 52 calculates the remaining capacity (SOC) based on the integrated value of the charging / discharging current detected by the current sensor in order to manage the battery 50, and calculates the remaining capacity (SOC) and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the above.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 that stores processing programs, a RAM 76 that temporarily stores data, an input / output port and communication (not shown), and the like. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled so as to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly when one cylinder misfire in which only one cylinder among the six cylinders of the engine 22 is continuously misfired is determined and one cylinder misfire is determined. Next, an operation for identifying a cylinder that misfires will be described. FIG. 3 is a flowchart showing an example of a misfire determination process executed by the engine ECU 24. This process is repeatedly executed every predetermined time.

  When the misfire determination process is executed, the CPU 24a of the engine ECU 24 first rotates the crank angle CA detected by the crank position sensor 140 and the crankshaft 26 calculated by the T30 calculation process illustrated in FIG. 4 by 30 degrees. The process for inputting the required 30-degree rotation time T30 (CA), which is the time required for the operation, is executed (step S100). Here, the time required for 30-degree rotation T30 (CA) is input every time the crank angle CA rotates 30 degrees based on the crank angle CA from the crank position sensor 140, as shown in the T30 calculation process. (Step S300), and the time required for 30 degrees T30 is calculated by calculating the difference between the input current time and the time input when the previous crank angle CA is rotated 30 degrees (Step S310). be able to. Here, the 30-degree required time T30 (CA) is the number of rotations of the engine 22 every time the crankshaft 26 rotates 30 degrees (hereinafter referred to as 30-degree rotation speed N30 (CA)). The degree of change in the rotational speed N30 (CA), that is, the rotational fluctuation is expressed using a unit of time.

  Subsequently, the input required 30-degree rotation time T30 is compared with the threshold value Trer (step S110). Here, the threshold value Tref is greater than the required 30-degree rotation time T30 when the cylinder that is in the combustion stroke is not misfiring at the crank angle CA that is the reference of the required 30-degree rotation time T30, and the cylinder is misfired. Is set as a value smaller than the required 30-degree rotation time T30, and can be obtained by experiments or the like. When the time required for 30-degree rotation T30 is equal to or less than the threshold value Tref, it is determined that the engine 22 has not misfired, a value of 0 is set in the one-cylinder misfire determination flag F (step S120), and the misfire determination process is terminated.

  When the time required for 30-degree rotation T30 is greater than the threshold value Tref, it is determined that any cylinder of the engine 22 has misfired, and only one of the six cylinders continuously misfires, that is, 720 degrees. It is determined whether or not a one-cylinder misfire has occurred in which the 30-degree rotation required time T30 corresponding to each crank angle CA is greater than the threshold value Tref (step S130). When it is determined that the one-cylinder misfire has not occurred, a value of 0 is set in the one-cylinder misfire determination flag F (step S120), and the misfire determination process is terminated.

  On the other hand, if it is determined that one cylinder is misfiring, next, the engine speed Ne and torque Te of the engine 22 are input (step S140), and the operating point of the engine 22 is determined based on the input engine speed Ne and torque Te. It is determined whether or not it is in the resonance region of the subsequent stage (such as the power distribution and integration mechanism 30) including the damper 28 (step S150). Here, in the embodiment, the rotation speed Ne of the engine 22 is input by calculation based on the crank angle CA from the crank position sensor 140, and the torque Te is calculated from the torque of the motor MG1. It was assumed that the calculated value was entered. As to whether or not the operating point of the engine 22 is in the subsequent resonance region including the damper 28, the rotational speed Ne and the torque Te of the engine 22 that become the resonance region are obtained in advance through experiments or the like and stored in the ROM 24b as the resonance operation range. In addition, the determination is made based on whether or not the input rotation speed Ne and torque Te of the engine 22 belong to the stored resonance operation range. Note that the resonance operation range can be obtained by experiments based on the characteristics of the engine 22 and the characteristics of the stage behind the damper 28 (power distribution and integration mechanism 30).

  If it is determined that the operation point of the engine 22 is not in the resonance region, the misfire cylinder is specified by the crank angle CA (step S160), and the specified misfire cylinder is stored in a predetermined region of the RAM 24c (step S170). A value 1 is set in the misfire determination flag F (step S180), and the misfire determination process is terminated. On the other hand, if it is determined that the operating point of the engine 22 is in the resonance region, it is determined whether or not the one-cylinder misfire determination flag F is a value 1 (step S190). It is determined that one cylinder misfire continues and the misfire cylinder can be regarded as the cylinder specified by the crank angle CA when the operating point of the engine 22 is not in the resonance region, and the same cylinder as the cylinder stored in the RAM 24c Is determined as a misfire cylinder (step S200), the misfire determination process is terminated, and when the one-cylinder misfire determination flag F is 0, it is determined that the cylinder that has misfired cannot be specified, and the misfire cylinder is specified. The misfire determination process is terminated without performing it.

  FIG. 5 shows an example of the time change of the 30 ° rotation required time T30 and the crank angle CA when one cylinder misfire occurs in the engine 22. FIG. 5 (a) shows the time change of the 30 degree rotation required time T30 and the crank angle CA when one cylinder misfire occurs when the operating point of the engine 22 is not in the resonance region. The time change of 30 degree | times rotation required time T30 and the crank angle CA when 1 cylinder misfire has arisen when a point belongs to a resonance area | region is shown. When the operating point of the engine 22 is not in the resonance region, as shown in FIG. 5 (a), the crank angle CA is required to rotate 30 degrees at a rate of once every 720 degrees, and the required time T30 exceeds the threshold value Tref. It can be determined that a misfire has occurred, and the misfired cylinder can be identified based on the corresponding crank angle CA. On the other hand, when the operating point of the engine 22 is in the resonance region, as shown in FIG. 5B, rotation by 30 degrees with respect to the crank angle CA corresponding to the misfired cylinder due to the effect of the subsequent resonance including the damper 28. The required time T30 appears as a small value that is less than or equal to the threshold Tref, and the required time T30 for 30 ° rotation with respect to the crank angle CA corresponding to the cylinder that has not misfired appears as a large value that exceeds the threshold Tref. The method described above cannot identify which cylinder is misfiring. In the embodiment, the misfire cylinder specified when one cylinder misfire occurs in the engine 22 in a state where the operation point of the engine 22 does not belong to the resonance region is stored, and the engine 22 is kept in a state where the one cylinder misfire continues. When this operating point belongs to the resonance region, the misfiring cylinder is identified by regarding that the same cylinder as the stored cylinder is misfiring.

  According to the hybrid vehicle 20 of the embodiment described above, the crank when the one-cylinder misfire is determined when the operation point of the engine 22 does not belong to the subsequent resonance region including the damper 28 when the one-cylinder misfire is determined. The misfiring cylinder is specified by the angle CA and stored in the RAM 24a. When one cylinder misfiring is continuously determined after the next time and the operating point of the engine 22 belongs to the resonance region, the cylinder stored in the RAM 24c is specified as the misfiring cylinder. Therefore, even if the operating point of the engine 22 belongs to the subsequent resonance region including the damper 28, it is possible to prevent the cylinder that has not misfired from being erroneously specified as the misfired cylinder.

  In the hybrid vehicle 20 according to the embodiment, the misfire of the engine 22 is determined based on the time T30 required as the time required for the crankshaft 26 to rotate 30 degrees, but the crankshaft 26 rotates 5 degrees. The misfire of the engine 22 may be determined using various required times such as the required time of 5 degrees T5 as the time required for the rotation and the required time of 10 degrees as the time required for the rotation of 10 degrees. Further, misfiring of the engine 22 is caused by using various rotation speeds such as 5 degrees rotation speed N5 which is the rotation speed of the crankshaft 26 every 5 degrees and 10 degrees rotation speed N10 which is the rotation speed of the crankshaft 26 every 10 degrees. It does not matter as a judgment.

  In the hybrid vehicle 20 of the embodiment, the misfire of the 6-cylinder engine 22 has been described. However, the misfire of the 4-cylinder engine may be determined, or the misfire of the 8-cylinder engine may be determined. As long as there are a plurality of cylinders, any engine misfire may be determined.

  In the hybrid vehicle 20 of the embodiment, when the operation point of the engine 22 is in the resonance region when the one-cylinder misfire is determined, or when the one-cylinder misfire is determined when the operation point of the engine 22 is not in the resonance region. Although the same cylinder as the misfire cylinder specified by the crank angle CA and stored in the RAM 24c is specified as the misfire cylinder, the misfire cylinder is specified by the crank angle CA even when the operating point of the engine 22 is in the resonance region. In addition, it is also possible to confirm whether or not the specified misfire cylinder matches the misfire cylinder specified by the crank angle CA when the operating point of the engine 22 is not in the resonance region.

  In the hybrid vehicle 20 of the embodiment, the power distribution and integration mechanism 30 is connected to the crankshaft 26 of the engine 22 via a damper 28 as a torsion element and is connected to the rotation shaft of the motor MG1 and the ring gear shaft 32a as a drive shaft. And the motor MG2 connected to the ring gear shaft 32a via the reduction gear 35, the engine 22 misfire determination device is used, but the crankshaft of the engine is connected to the subsequent stage via a damper as a torsion element. 6, the power of the motor MG2 is different from the axle to which the ring gear shaft 32a is connected (the axle to which the drive wheels 63a and 63b are connected) as illustrated in the hybrid vehicle 120 of the modification of FIG. It shall be connected to the axle (the axle connected to the wheels 64a and 64b in FIG. 6). Alternatively, as illustrated in the hybrid vehicle 220 of the modification of FIG. 7, the axle side that outputs power to the inner rotor 232 and the drive wheels 63a and 63b connected to the crankshaft 26 of the engine 22 via the damper 28. An outer rotor 234 connected to the motor, and includes a counter-rotor motor 230 that transmits a part of the power of the engine 22 to the axle side and converts the remaining power into electric power, and determines the misfire of the engine 22 Also good. In this case, the motor MG2 may be connected to the axle side via the reduction gear 35 or the transmission, or may be connected to the axle side without passing through the reduction gear 35 or the transmission.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the “internal combustion engine”, the crank position sensor 140 corresponds to the “rotational position detection means”, and the crank angle CA rotates 30 degrees based on the crank angle CA from the crank position sensor 140. The engine ECU 24 that executes the T30 calculation process for calculating the required time T30 by calculating the difference between the current time and the previous time every time corresponds to the “rotational fluctuation calculation means”, and every 720 degrees. In addition, the engine ECU 24 that executes the processes of steps S110 and S130 of the misfire determination process for determining whether or not the required 30-degree rotation time T30 corresponding to the crank angle CA is greater than the threshold value Tref corresponds to “one-cylinder misfire determination means”. The RAM 24c corresponds to “storage means”, and when the one-cylinder misfire is determined, the operation point of the engine 22 is reduced. When it does not belong to the subsequent resonance region including 28, it is specified as a misfiring cylinder by the crank angle CA when one cylinder misfire is determined, and is stored in the RAM 24a, and the one cylinder misfire determination flag F is set to a value of 1, When the misfire is determined, if the operating point of the engine 22 belongs to the resonance region and the one-cylinder misfire determination flag F is 1, the misfire determination process of steps S140 to S200 for identifying the cylinder stored in the RAM 24c as the misfire cylinder. The engine ECU 24 that executes the process corresponds to “misfire cylinder specifying means”. Further, the motor MG1 corresponds to a “generator”, the power distribution and integration mechanism 30 corresponds to a “triaxial power input / output unit”, and the motor MG2 corresponds to a “motor”.

  Here, the “internal combustion engine” is not limited to an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, but a hydrogen engine or the like and a subsequent stage through a torsion element such as a damper. Any type of internal combustion engine may be used as long as it has a plurality of cylinders connected to the shaft. The “rotational position detecting means” is not limited to the crank position sensor 140, and any other device such as a cam position sensor 144 may be used as long as the rotational position of the internal combustion engine can be detected. As the “rotational fluctuation calculating means”, every time the crank angle CA rotates 30 degrees based on the crank angle CA from the crank position sensor 140, the difference between the current time and the previous time is calculated by 30. It is not limited to the one that calculates the required time T30, and any other method may be used as long as it calculates the rotational fluctuation based on the rotational position of the internal combustion engine. The “one-cylinder misfire determination means” is not limited to one that determines whether or not the required 30-degree rotation time T30 corresponding to the crank angle CA is greater than the threshold value Tref every 720 degrees. Any other method may be used as long as it can determine misfire of the internal combustion engine based on the fluctuation. The “storage means” is not limited to the RAM 24c, and any storage means such as a flash memory can be used. As the “misfire cylinder specifying means”, when one cylinder misfire is determined, when the operating point of the engine 22 does not belong to the subsequent resonance region including the damper 28, misfire is caused by the crank angle CA when the one cylinder misfire is determined. The cylinder is specified and stored in the RAM 24a, and the one-cylinder misfire determination flag F is set to a value 1. When one-cylinder misfire is determined, the operating point of the engine 22 belongs to the resonance region and the one-cylinder misfire determination flag F is set. When the value is 1, it is not limited to specifying the cylinder stored in the RAM 24c as a misfiring cylinder, and the internal combustion engine is not operated at an operating point in a resonance generating region where resonance based on torsion of a torsion element occurs. Sometimes when the one-cylinder misfire determination means determines that one-cylinder misfire has occurred, the rotational position of the output shaft used when the one-cylinder misfire is determined. The corresponding cylinder is specified as a misfiring cylinder and stored in the storage means. When the internal combustion engine is operated at the operating point in the resonance generating region, the stored cylinder is stored when the one-cylinder misfiring determining means determines that one cylinder is misfiring. As long as the same cylinder is specified as the misfiring cylinder, any cylinder may be used. The “generator” is not limited to the motor MG1 configured as a synchronous generator motor, and may be any type of generator such as an induction motor that can input and output power. The “three-axis power input / output means” is not limited to the power distribution / integration mechanism 30 described above, but includes four or more shafts using a double pinion type planetary gear mechanism or a combination of a plurality of planetary gear mechanisms. Power is input / output to the remaining one axis based on the power input / output to any two of the three axes, such as those connected to the motor or those having a differential action different from the planetary gear such as a differential gear. Anything can be used. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor as long as it can input and output power to the drive shaft, such as an induction motor. . The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems is the same as that of the embodiment described in the column of means for solving the problems. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problems. In other words, the interpretation of the invention described in the column of means for solving the problem should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problem. It is only a specific example.

  Although the embodiment has been described as the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20, the present invention may be applied to a misfire determination device for an internal combustion engine mounted on a vehicle that does not include a motor or generator for traveling. Good. Further, the present invention may be applied to a misfire determination device for an internal combustion engine mounted on a moving body such as a vehicle other than an automobile, a ship, or an aircraft, or may be applied to a misfire determination device for an internal combustion engine incorporated in a facility that does not move. It doesn't matter. Moreover, it is good also as a form of the misfire determination method of an internal combustion engine instead of the form of the misfire determination apparatus of an internal combustion engine or the vehicle which mounts this.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention is applicable to the automobile industry and the like.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. 2 is a configuration diagram showing an outline of a configuration of an engine 22. FIG. 5 is a flowchart showing an example of misfire determination processing executed by an engine ECU 24. It is a flowchart which shows an example of T30 arithmetic processing. It is explanatory drawing which shows an example of the time change of 30 degree | times rotation required time T30 and crank angle CA when 1 cylinder misfire has arisen in the engine 22. FIG. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example.

Explanation of symbols

20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 24a CPU, 24b ROM, 24c RAM, 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35 reduction gear, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control Unit (battery ECU), 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b driving wheel, 64a, 64b wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 0 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 122 Air cleaner, 124 Throttle valve, 126 Fuel injection valve, 128 Intake valve, 130 Spark plug, 132
Piston, 134 Purification device, 135a Air-fuel ratio sensor, 135b Oxygen sensor, 136, Throttle motor, 138 Ignition coil, 140 Crank position sensor, 142 Water temperature sensor, 144 Cam position sensor, 146 Throttle valve position sensor, 148 Air flow meter, 149 Temperature Sensor, 150 variable valve timing mechanism, 230 rotor motor, 232 inner rotor, 234 outer rotor, MG1, MG2 motor.

Claims (4)

A misfire determination device for an internal combustion engine that determines misfire of a multi-cylinder internal combustion engine in which an output shaft is connected to a rear shaft of a rear stage through a torsion element,
Rotational position detecting means for detecting the rotational position of the output shaft of the internal combustion engine;
Rotation fluctuation calculating means for calculating the rotation fluctuation of the internal combustion engine based on the detected rotation position of the output shaft;
One-cylinder misfire determination means for determining one-cylinder misfire in which one cylinder among the plurality of cylinders of the internal combustion engine continuously misfires based on the calculated rotation fluctuation;
Storage means for storing data;
When the internal combustion engine is not operated at an operating point in a resonance generating region where resonance based on torsion of the torsion element is generated, when the one cylinder misfire determination means determines that one cylinder misfire has occurred, it is determined that the one cylinder misfire has occurred. The cylinder corresponding to the rotational position of the output shaft used at the time is specified as a misfiring cylinder and stored in the storage means, and when the internal combustion engine is operated at an operating point in the resonance generating region, Misfire cylinder specifying means for specifying the same cylinder as the stored cylinder as the misfire cylinder when the cylinder misfire determination means determines that one cylinder is misfired;
A misfire determination apparatus for an internal combustion engine. A multi-cylinder internal combustion engine whose output shaft is connected to the rear shaft of the rear stage via a torsion element;
The misfire determination device for an internal combustion engine according to claim 1, wherein the misfire determination of the internal combustion engine is determined.
A vehicle comprising: The vehicle according to claim 2,
A generator capable of inputting and outputting power;
Connected to three shafts of the rear shaft, the generator rotating shaft and the axle shaft rotating shaft, and power is input / output to the remaining one shaft based on power input / output to any two of the three shafts. Three-axis power input / output means for
An electric motor capable of inputting and outputting power to the rotating shaft on the axle side;
A vehicle comprising: A misfire determination method for an internal combustion engine for determining misfire of a multi-cylinder internal combustion engine in which an output shaft is connected to a rear stage shaft through a torsion element,
(A) calculating the rotational fluctuation of the internal combustion engine based on the rotational position of the output shaft;
(B) determining one cylinder misfire in which one cylinder among the plurality of cylinders of the internal combustion engine continuously misfires based on the calculated rotation fluctuation;
(C) When the internal combustion engine is not operated at an operating point in a resonance generating region where resonance based on torsion of the torsion element is generated, and when it is determined that one cylinder misfire occurs in the step (b), the one cylinder misfire The cylinder corresponding to the rotational position of the output shaft used at the time of determination is specified and stored as a misfire cylinder, and the step (b) is performed when the internal combustion engine is operated at an operating point in the resonance generating region. ), The same cylinder as the stored cylinder is specified as the misfire cylinder when the misfire is determined as one cylinder misfire.

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