JP2010126064A - Misfire determination device for internal combustion engine and misfire determination method for internal combustion engine - Google Patents

Abstract

Even when a pressing torque is output, misfire of an internal combustion engine mounted on a hybrid vehicle in which the internal combustion engine is connected to an axle via a gear mechanism is more accurately determined.
When a braking force of a predetermined braking force or more is applied and the vehicle is stopped, when a pressing torque is not output from a motor MG2, a comparison is made between the input required 30 degree rotation time T30 and a threshold value Tref1. The misfire of the target cylinder is determined (S120, S130), and when the pressing torque is output from the motor MG2, the misfire of the target cylinder is compared by comparing the input required 30 degree rotation time T30 and the threshold value Tref2 smaller than the threshold value Tref1. Is determined (S140, S130). Thereby, even when the pressing torque is output from the motor MG2, misfire of the target cylinder can be determined with higher accuracy.
[Selection] Figure 3

Description

  The present invention relates to an internal combustion engine misfire determination apparatus and an internal combustion engine misfire determination method.

  Conventionally, as this kind of misfire determination device for an internal combustion engine, a device that stops misfire detection processing when there is a possibility of misdetecting misfire based on the driving state of the vehicle has been proposed (for example, see Patent Document 1). . In this apparatus, when there is a possibility of misdetecting misfire based on the driving state of the vehicle, misfire detection is suppressed by stopping misfire detection processing.

Further, in a hybrid vehicle in which an engine is connected to an axle via a gear mechanism, a motor that outputs a pressing torque from the motor to one side of the gear mesh of the gear mechanism at the time of starting has been proposed (for example, Patent Documents). 2). Thus, by outputting the pressing torque, it is possible to suppress the generation of abnormal noise from the gear mechanism or the like when the engine is started.
JP2007-55460 JP 2001-317402 A

  However, when the processing of the misfire determination device for an internal combustion engine described above is applied at the time of starting the hybrid vehicle described above, it is determined that misfire detection may be erroneously detected by the output of the pressing torque, and the misfire detection processing is stopped when the misfire detection processing is stopped. Sometimes it is not possible to make a misfire determination. In this case, emission is deteriorated.

  An internal combustion engine misfire determination apparatus and an internal combustion engine misfire determination method according to the present invention include an internal combustion engine mounted on a hybrid vehicle in which the internal combustion engine is connected to an axle via a gear mechanism even when a pressing torque is output. The main purpose is to more accurately determine misfires.

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

An internal combustion engine misfire determination device of the present invention,
A first rotating element of three rotating elements is connected to a multi-cylinder internal combustion engine and a connecting shaft connected to an output shaft of the internal combustion engine via a torsion element, and connected to an axle via a gear mechanism. A planetary gear mechanism in which a second rotating element is connected to the driven drive shaft, a generator connected to the third rotating element of the planetary gear mechanism, and mechanically so as to input and output power to the drive shaft. A misfire determination device for an internal combustion engine that determines a misfire of the internal combustion engine in a hybrid vehicle comprising: a connected motor; and a power storage means capable of exchanging electric power with the generator and the motor,
Rotational position detecting means for detecting the rotational position of the output shaft;
Rotation fluctuation calculating means for calculating the rotation fluctuation of the output shaft for each predetermined rotation angle based on the detected rotation position;
A predetermined pressing torque for suppressing generation of abnormal noise due to pulsation of torque output from the internal combustion engine when a braking force greater than a predetermined braking force is applied and the vehicle stops is transmitted from the electric motor to the gear mechanism. When the output is not output to one side of the gear meshing, a misfire of the internal combustion engine is determined by comparing the calculated rotational fluctuation with a first threshold, and the predetermined pressing torque is transmitted from the electric motor to the gear mechanism. Misfire determination means for determining misfire of the internal combustion engine by comparing the calculated rotational fluctuation with a second threshold value smaller than the first threshold value when being output to one side of the gear meshing of
It is a summary to provide.

  The misfire determination apparatus for an internal combustion engine according to the present invention suppresses the generation of abnormal noise due to the pulsation of torque output from the internal combustion engine when a braking force greater than a predetermined braking force is applied to stop the vehicle. When the predetermined pressing torque is not output from the electric motor to one side of the gear meshing of the gear mechanism, the misfire of the internal combustion engine is determined by comparing the rotation fluctuation of the output shaft of the internal combustion engine with the first threshold value. When the pressing torque is output from the electric motor to one side of the gear meshing of the gear mechanism, the misfire of the internal combustion engine is determined by comparing the rotation fluctuation of the output shaft of the internal combustion engine with a second threshold value smaller than the first threshold value. To do. Here, when the misfire of the internal combustion engine is determined by comparing the rotation fluctuation of the output shaft of the internal combustion engine and the first threshold value regardless of whether or not the predetermined pressing torque is output, the predetermined pressing torque is When output from the electric motor to one side of the gear meshing of the gear mechanism, the rotational fluctuation of the output shaft of the internal combustion engine can be suppressed to be relatively small, and therefore misfire of the internal combustion engine cannot be accurately determined. On the other hand, in the misfire determination device for an internal combustion engine of the present invention, when the predetermined pressing torque is output, the rotation variation of the output shaft of the internal combustion engine and the first pressing torque used when the predetermined pressing torque is not output. Since misfire of the internal combustion engine is determined by comparison with a second threshold value smaller than the threshold value of 1, even when a predetermined pressing torque is output, misfire of the internal combustion engine can be determined with higher accuracy.

  In the misfire determination apparatus for an internal combustion engine of the present invention, the second threshold value may be set so as to decrease as the predetermined pressing torque increases. Thereby, misfire of the internal combustion engine can be determined with higher accuracy even when a predetermined pressing torque is output.

The misfire determination method of the internal combustion engine of the present invention,
A first rotating element of three rotating elements is connected to a multi-cylinder internal combustion engine and a connecting shaft connected to an output shaft of the internal combustion engine via a torsion element, and connected to an axle via a gear mechanism. A planetary gear mechanism in which a second rotating element is connected to the driven drive shaft, a generator connected to the third rotating element of the planetary gear mechanism, and mechanically so as to input and output power to the drive shaft. An internal combustion engine misfire determination method for determining misfire of the internal combustion engine in a hybrid vehicle comprising a connected electric motor, and a power storage means capable of exchanging electric power with the generator and the electric motor,
Detecting the rotational position of the output shaft and calculating the rotational fluctuation of the output shaft for each predetermined rotational angle based on the detected rotational position;
When a braking force greater than a predetermined braking force is applied and the vehicle is stopped, a predetermined pressing torque for suppressing the generation of abnormal noise due to the pulsation of the torque output from the internal combustion engine has a gear of the gear mechanism. Determining that the internal combustion engine has misfired by comparing the rotation variation of the output shaft calculated based on the rotational position of the output shaft and a first threshold when the electric motor is not outputting to one side of the meshing, When a predetermined pressing torque is output from the electric motor to one side of the gear meshing of the gear mechanism, the internal combustion engine is compared by comparing the rotation fluctuation of the output shaft with a second threshold value smaller than the first threshold value. To determine the misfire of
It is characterized by that.

  The misfire determination method for an internal combustion engine according to the present invention is for suppressing the generation of noise due to the pulsation of torque output from an internal combustion engine when a braking force exceeding a predetermined braking force is applied and the vehicle is stopped. When the predetermined pressing torque is not output from the electric motor to one side of the gear meshing of the gear mechanism, the misfire of the internal combustion engine is determined by comparing the rotation fluctuation of the output shaft of the internal combustion engine with the first threshold value. When the pressing torque is output from the electric motor to one side of the gear meshing of the gear mechanism, the misfire of the internal combustion engine is determined by comparing the rotation fluctuation of the output shaft of the internal combustion engine with a second threshold value smaller than the first threshold value. To do. Here, when the misfire of the internal combustion engine is determined by comparing the rotation fluctuation of the output shaft of the internal combustion engine and the first threshold value regardless of whether or not the predetermined pressing torque is output, the predetermined pressing torque is When output from the electric motor to one side of the gear meshing of the gear mechanism, the rotational fluctuation of the output shaft of the internal combustion engine can be suppressed to be relatively small, and therefore misfire of the internal combustion engine cannot be accurately determined. On the other hand, in the misfire determination device for an internal combustion engine of the present invention, when the predetermined pressing torque is output, the rotation variation of the output shaft of the internal combustion engine and the first pressing torque used when the predetermined pressing torque is not output. Since misfire of the internal combustion engine is determined by comparison with a second threshold value smaller than the threshold value of 1, even when a predetermined pressing torque is output, misfire of the internal combustion engine can be determined with higher accuracy.

  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 a configuration of a hybrid vehicle 20 equipped with an internal combustion engine misfire determination apparatus according to an embodiment of the present invention. The hybrid vehicle 20 according to the embodiment is connected to the engine 22, a planetary gear mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and the planetary gear mechanism 30. A power generation motor MG1, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the planetary gear mechanism 30, a motor MG2 connected to the reduction gear 35, and a hybrid for controlling the entire vehicle And an electronic control unit 70.

  The engine 22 is configured as a four-cylinder internal combustion engine capable of outputting 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, and the intake air and the gasoline are mixed. The mixture is sucked into the fuel chamber through the intake valve 128, and is generated by an electric spark by the spark plug 130. Explosive combustion is performed, and the reciprocating motion of the piston 132 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 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 cooling water temperature from the combustion chamber, the in-cylinder pressure Pin from the pressure sensor 143 installed in the combustion chamber, the intake valve 128 that performs intake and exhaust to the combustion chamber, and the cam position sensor 144 that detects the rotational position of the camshaft that opens and closes the exhaust valve Cam position, throttle position from throttle valve position sensor 146 for detecting the position of throttle valve 124, air flow meter signal AF from air flow meter 148 attached to the intake pipe, and temperature sensor also attached to the intake pipe Intake air temperature from 49, the air-fuel ratio AF from an air-fuel ratio sensor 135a, such as oxygen signal from an oxygen sensor 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 engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on the crank position from the crank position sensor 140.

  The planetary gear 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, And a carrier 34 that holds the pinion gear 33 so as to rotate and revolve, and the sun gear 31, the ring gear 32, and the carrier 34 are used as rotating elements to perform differential action. In the planetary gear 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, and the motor MG1 generates power. When the motor MG1 functions as a motor, the 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 22 input from the carrier 34. 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 gear mechanism 60 is provided with a parking lock mechanism 56 comprising a parking gear 57 attached to the final gear 60a, and a parking lock pole 58 that engages with the parking gear 57 and locks it in a state where its rotational drive is stopped. . The parking lock pole 58 is provided with an actuator (not shown) by the hybrid electronic control unit 70 to which an operation signal from another position of the shift lever 81 to the parking position (P position) or an operation signal from the parking position to another position is input. It operates by being driven and controlled, and engages with the parking gear 57 and releases the parking lock and releases it. Since the final gear 60a is mechanically connected to the drive wheels 63a and 63b, the parking lock mechanism 56 indirectly locks the drive wheels 63a and 63b.

  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 applied to the motors MG1 and MG2 to be applied 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 motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  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.

  The brake actuator 92 has a braking force corresponding to the share of the brake in the braking force applied to the vehicle by the pressure (brake pressure) of the brake master cylinder 90 and the vehicle speed V generated in response to the depression of the brake pedal 85. The brake wheel cylinders 96a to 96d are adjusted so as to act on the driven wheels 63b and the driven wheels (not shown), and the braking wheels act on the driving wheels 63a, 63b and the driven wheels regardless of the depression of the brake pedal 85. The hydraulic pressures of 96a to 96d can be adjusted. The brake actuator 92 is controlled by a brake electronic control unit (hereinafter referred to as a brake ECU) 94. The brake ECU 94 inputs signals such as a wheel speed from a wheel speed sensor (not shown) attached to the driving wheels 63a and 63b and the driven wheel and a steering angle from a steering angle sensor (not shown) by a signal line (not shown). When the driver depresses the brake pedal 85, an anti-lock brake system function (ABS) that prevents any of the driving wheels 63a, 63b and the driven wheels from slipping due to the lock or when the driver depresses the accelerator pedal 83 Traction control (TRC) for preventing any one of the drive wheels 63a and 63b from slipping due to idling, posture holding control (VSC) for holding the posture while the vehicle is turning, and the like are also performed. The brake ECU 94 communicates with the hybrid electronic control unit 70, and controls the drive of the brake actuator 92 by a control signal from the hybrid electronic control unit 70, and the data regarding the state of the brake actuator 92 is used for the hybrid as necessary. Output to the electronic control unit 70.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. 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 pedal 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, the battery ECU 52, and the brake ECU 94 via a communication port, and the engine ECU 24, the motor ECU 40, the battery ECU 52, the brake ECU 94, and various control signals. And exchanging data. In the hybrid vehicle 20 of the embodiment, as the shift position SP of the shift lever 81, the parking position (P position) used during parking, the reverse position (R position) for reverse travel, the neutral position (N position), the forward position A normal driving position (D position) for traveling is prepared.

  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 power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear mechanism 30. Torque conversion is performed by the motor MG1 and the motor MG2, and the torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so as to be output to the ring gear shaft 32a and the power required for charging and discharging the battery 50 are met. Operation of the engine 22 is controlled so that power is output from the engine 22, and all or part of the power output from the engine 22 with charge / discharge of the battery 50 is transmitted to the planetary gear mechanism 30, the motor MG1, and the motor MG2. The required power is output to the ring gear shaft 32a with torque conversion by A charge / discharge operation mode for driving and controlling the motor MG1 and the motor MG2 and a motor operation mode for controlling the operation so that the operation of the engine 22 is stopped and power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. .

  Further, in the hybrid vehicle 20 of the embodiment, when the engine 22 is autonomously operated when a braking force greater than a predetermined braking force is applied and the vehicle is stopped, it is executed by the hybrid electronic control unit 70 (not shown). The planetary gear mechanism 30 and the reduction gear 35 are associated with the torque pulsation of the engine 22 except when the motor MG2 cannot be driven and controlled, such as when the SOC of the battery 50 is small and sufficient power cannot be supplied to the motor MG2 by the pressing control routine. In order to prevent gear rattling noise from being generated in the gear mechanism 60, torque that is pressed against one side of the gear meshing of the gear mechanism 60 (hereinafter referred to as pressing torque) is output from the motor MG2. Here, as the pressing torque, a torque slightly larger than the amplitude of the torque pulsation generated based on the combustion cycle of the engine 22 acting on the ring gear shaft 32a as the drive shaft is output to the ring gear shaft 32a. The predetermined braking force is a minimum braking force that can maintain a stopped state even when the above-described pressing torque is output from the motor MG2. For example, the brake pedal 85 is depressed relatively large to drive the wheels 63a. , 63b and the driven wheel, the driving wheels 63a, 63b are locked by the parking lock mechanism 56 when the shift position SP is in the P position even when the braking force is applied to the driven wheel or the brake pedal 85 is not depressed. When the vehicle is on, the vehicle can be stopped by applying a braking force greater than the predetermined braking force described above.

  Next, an operation for determining whether any cylinder of the engine 22 mounted in the hybrid vehicle 20 of the embodiment configured as described above has misfired will be described. FIG. 3 is a flowchart showing an example of a stop misfire determination process executed by the engine ECU 24. This routine is repeatedly executed at predetermined time intervals when the engine 22 is autonomously operated while the vehicle is stopped due to a braking force that is greater than or equal to the predetermined braking force described above.

  When the stop 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. A process of inputting a 30-degree rotation required time T30, which is a time required for the operation, and a pressing execution flag F indicating whether or not the pressing torque is output from the motor MG2 is executed (step S100). Here, as the time required for 30-degree rotation T30, the value calculated by the T30 calculation process illustrated in FIG. 4 is input. In the T30 calculation process of FIG. 4, every time the crank angle CA rotates 30 degrees based on the crank angle CA from the crank position sensor 140, the current time is input (step S200), and the current time and the previous crank angle CA are input. Is calculated by calculating the difference from the time input when the motor rotates 30 degrees (step S210), and the T30 calculation process is terminated. The 30 degree rotation required time T30 is obtained by multiplying the rotation speed Ne of the engine 22 by (360/30) when the reciprocal is taken, and thus represents the degree of change in the rotation speed Ne of the engine 22. . The pressing execution flag F is set to a value of 1 when the pressing torque is output from the motor MG2 by the above-described pressing control routine executed by the hybrid electronic control unit 70, and the pressing torque from the motor MG2 is set. When the value is not output, the value set to 0 is input by communication.

  When the data is input in this way, it is determined whether or not the input pressing execution flag F is 0 (step S110). When the pressing execution flag F is 0, that is, when the pressing torque is not output from the motor MG2, the input 30 degree rotation required time T30 is compared with the threshold value Tref1 (step S120). Here, the threshold value Tref1 is set as a value slightly smaller than the time required for the crankshaft 26 to rotate 30 degrees when the engine 22 misfires when no pressing torque is output from the motor MG2. Therefore, when the input 30-degree rotation required time T30 is greater than the threshold value Tref1, it is determined that the target cylinder has misfired (step S130), the stop-time misfire determination process is terminated, and the input 30-degree rotation required time T30 is When it is equal to or lower than the threshold value Tref1, it is determined that the target cylinder has not misfired, and the misfire determination process at the time of stopping is terminated. An example of the time change of the required rotation time T30 of the engine 22 and the crank angle CA when one cylinder of the engine 22 is misfiring when the vehicle MG2 is stopped in a state where no pressing torque is output from the motor MG2. Is shown in FIG. As shown in the figure, the required rotation time T30 for the crank angle CA is once every 720 degrees and exceeds the threshold value Tref1.

  When the pressing execution flag F is 1 (step S110), that is, when the pressing torque is output from the motor MG2, the input 30 ° rotation required time T30 is compared with the threshold value Tref2 (step S140). Here, the threshold value Tref2 is smaller than the threshold value Tref1 that is used when the pressing torque is not output from the motor MG2, and the crankshaft 26 is activated when the engine 22 misfires when the pressing torque is output from the motor MG2. It is set as a value slightly smaller than the time required to rotate 30 degrees. Therefore, when the input 30-degree rotation required time T30 is greater than the threshold value Tref2, it is determined that the target cylinder has misfired (step S130), the stop-time misfire determination process is terminated, and the input 30-degree rotation required time T30 is When the threshold value Tref2 or less, it is determined that the target cylinder has not misfired, and the misfire determination process at the time of stop is terminated. The threshold value Tref2 used when the pressing torque is output from the motor MG2 is smaller than the threshold value Tref1 used when the pressing torque is not output. This is because the pressing torque from the motor MG2 is equal to the ring gear shaft 32a. Not only does it affect the crankshaft 26 but also the amount of variation in the required rotation time T30 when the pressing torque is output from the motor MG2 is smaller than when the pressing torque is not output. Based on the experimental results. An example of the time change between the time T30 required for 30-degree rotation of the engine 22 and the crank angle CA when one cylinder of the engine 22 is misfiring when the vehicle MG2 is stopped with the pressing torque being output from the motor MG2. Is shown in FIG. As shown in the figure, when the pressing torque is output from the motor MG2, the required rotation time T30 does not exceed the threshold Tref1, although the crank angle CA exceeds the threshold Tref2 at a rate of once every 720 degrees. . Therefore, even if the threshold value Tref1 used when the motor MG2 outputs the pressing torque and the 30-degree rotation required time T30 are compared, the misfire of the target cylinder cannot be determined. However, in the embodiment, since the threshold value Tref2 smaller than the threshold value Tref1 is compared with the time required for 30-degree rotation T30, misfire of the target cylinder can be determined. As a result, misfire of the engine 22 can be determined with higher accuracy even when the pressing torque is output from the motor MG2.

  According to the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment described above, when the pressing torque is not output from the motor MG2, the target is obtained by comparing the time required for 30 ° rotation T30 and the threshold value Tref1. When the misfire of the cylinder is determined, and the motor MG2 outputs a pressing torque, the misfire of the target cylinder is determined by comparing the required rotation time T30 of 30 degrees with the threshold Tref2 smaller than the threshold Tref1. Even when the pressing torque is being output from, misfire of the target cylinder can be determined more accurately.

  In the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment, the threshold value Tref2 used when the pressing torque is output from the motor MG2 is a fixed value, but is output from the motor MG2. It is good also as what is fluctuate | varied in the tendency to become small, so that the pressing torque which is being applied is large.

  In the internal combustion engine misfire determination apparatus mounted on the hybrid vehicle 20 of the embodiment, the misfire of any cylinder of the 4-cylinder engine 22 is determined. However, the misfire of any cylinder of the 6-cylinder engine is determined. Any number of cylinders may be used as long as it determines the misfire of any cylinder of the multi-cylinder engine, such as to determine the misfire of any cylinder of the 8-cylinder engine. Absent.

  Although the embodiment has been described as the misfire determination device for the internal combustion engine mounted on the hybrid vehicle 20, the misfire determination method for the internal combustion engine may be used.

  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 an “internal combustion engine”, the planetary gear mechanism 30 corresponds to a “planetary gear mechanism”, the motor MG1 corresponds to a “generator”, the motor MG2 corresponds to a “motor”, The battery 50 corresponds to “power storage means”, the crank position sensor 140 corresponds to “rotation position detection means”, and the crankshaft 26 rotates 30 degrees based on the crank angle CA from the crank position sensor 140 at that time. 4 is executed, and the T30 calculation process of FIG. 4 is performed to calculate the time required for 30-degree rotation T30 by calculating the difference between the current time and the time input when the previous crank angle CA is rotated 30 degrees. The engine ECU 24 corresponds to “rotational fluctuation calculation means” and is input when the pressing torque is not output from the motor MG2 when the vehicle is stopped. A comparison between the 30-degree required rotation time T30 and the threshold value Tref1 determines misfire of the target cylinder. When the pressing torque is output from the motor MG2, the input 30-degree rotation required time T30 and the threshold value Tref2 smaller than the threshold value Tref1 The engine ECU 24 that executes the stop-time misfire determination process of FIG. 3 for determining misfire of the target cylinder by comparing the above corresponds to “misfire determination means”. Here, the “internal combustion engine” is not limited to an internal combustion engine that outputs power using a hydrocarbon fuel such as gasoline or light oil, and may be any type of internal combustion engine such as a hydrogen engine. . The “planetary gear mechanism” is not limited to the planetary gear mechanism 30 described above, but includes three connecting shafts connected to the output shaft of the internal combustion engine via a torsion element, such as a double pinion type planetary gear mechanism. Any one of the rotating elements may be used as long as the first rotating element is connected and the second rotating element is connected to the drive shaft connected to the axle via a gear mechanism. The “generator” is not limited to the motor MG1 configured as a synchronous generator motor, and may be any one as long as it is connected to the third rotating element of the planetary gear mechanism, such as an induction motor. Absent. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any motor as long as it is mechanically connected to input / output power to the drive shaft. The “storage means” is not limited to the battery 50 as a secondary battery, and may be anything as long as it can exchange electric power with a generator or an electric motor such as a capacitor. The “rotational position detecting means” is not limited to the crank position sensor 140, and any other means such as a cam position sensor 144 may be used as long as it detects the rotational position of the output shaft of the internal combustion engine. It doesn't matter what. As the “rotational fluctuation calculating means”, the time at that time is input every time the crankshaft 26 rotates 30 degrees based on the crank angle CA from the crank position sensor 140, and the current time and the previous crank angle CA are 30 degrees. It is not limited to the calculation of the time required for 30-degree rotation T30 by calculating the difference from the time input when the engine is rotated, but the output of the internal combustion engine at every predetermined rotation angle based on the detected rotation position. Any method can be used as long as it can calculate the rotational fluctuation of the shaft. As the “misfire determination means”, when a braking force greater than a predetermined braking force is applied and the vehicle is stopped, when the pressing torque is not output from the motor MG2, a 30-degree rotation required time T30 and a threshold Tref1 are set. The misfire of the target cylinder is determined by comparison, and when the pressing torque is output from the motor MG2, the misfire of the target cylinder is determined by comparing the input required 30 degree rotation time T30 and the threshold value Tref2 smaller than the threshold value Tref1. The present invention is not limited to the above, and a predetermined push for suppressing the generation of noise due to the pulsation of torque output from the internal combustion engine when the vehicle is stopped due to a braking force greater than the predetermined braking force. When the contact torque is not output from the electric motor to one side of the gear meshing of the gear mechanism, the calculated rotation fluctuation is compared with the first threshold value to determine the internal combustion engine. When a predetermined pressing torque is output from the electric motor to one side of the gear meshing of the gear mechanism, a comparison is made between the calculated rotational fluctuation and a second threshold value smaller than the first threshold value. Any method can be used as long as it determines the misfire of the internal combustion engine.

  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 problem is the same as that of the embodiment described in the column of means for solving the problem. 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 problem. That is, the interpretation of the invention described in the column of means for solving the problems 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 problems. It is only a specific example.

  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 can be used in the manufacturing industry of hybrid vehicles.

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 the configuration of an engine 22. FIG. 5 is a flowchart illustrating an example of a stop misfire determination process executed by an engine ECU 24. It is a flowchart which shows an example of the calculation process of 30 degree | times rotation required time T30. An example of the time change of the required rotation time T30 of the engine 22 and the crank angle CA when one cylinder of the engine 22 is misfiring when the vehicle MG2 is stopped in a state where no pressing torque is output from the motor MG2. It is explanatory drawing which shows. An example of the time change between the time T30 required for 30-degree rotation of the engine 22 and the crank angle CA when one cylinder of the engine 22 is misfiring when the vehicle MG2 is stopped with the pressing torque being output from the motor MG2. It is explanatory drawing which shows.

Explanation of symbols

  20 hybrid vehicle, 22 engine, 24 electronic control unit (engine ECU) for engine, 24a CPU, 24b ROM, 24c RAM, 26 crankshaft, 28 damper, 30 planetary gear 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 Electric power line, 56 Parking lock mechanism, 57 Parking gear, 58 Parking lock pole, 60 Gear mechanism, 60a Final gear, 62 Differential gear, 63a, 63b Drive wheel 64a, 64b driven wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 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, 90 Brake master cylinder, 92 Brake actuator, 94 Brake electronic control unit (brake ECU), 96a to 96d Brake wheel cylinder, 122 Air cleaner, 124 Throttle valve, 126 Fuel injection valve, 128 Intake valve, 130 Spark plug, 131 Exhaust valve, 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, 143 pressure sensor, 144 cam position sensor, 146 throttle valve position sensor, 148 air flow meter, 149 temperature sensor, 150 variable valve timing mechanism, MG1 , MG2 motor.

Claims (3)

A first rotating element of three rotating elements is connected to a multi-cylinder internal combustion engine and a connecting shaft connected to an output shaft of the internal combustion engine via a torsion element, and connected to an axle via a gear mechanism. A planetary gear mechanism in which a second rotating element is connected to the driven drive shaft, a generator connected to the third rotating element of the planetary gear mechanism, and mechanically so as to input and output power to the drive shaft. A misfire determination device for an internal combustion engine that determines a misfire of the internal combustion engine in a hybrid vehicle comprising: a connected motor; and a power storage means capable of exchanging electric power with the generator and the motor,
Rotational position detecting means for detecting the rotational position of the output shaft;
Rotation fluctuation calculating means for calculating the rotation fluctuation of the output shaft for each predetermined rotation angle based on the detected rotation position;
A predetermined pressing torque for suppressing the generation of abnormal noise due to the pulsation of the torque output from the internal combustion engine is applied from the motor to the gear when the vehicle is stopped due to a braking force greater than a predetermined braking force. When it is not output to one side of the meshing of the gear of the mechanism, a misfire of the internal combustion engine is determined by comparing the calculated rotational fluctuation with a first threshold, and the predetermined pressing torque is transmitted from the electric motor to the gear. Misfire determination means for determining misfire of the internal combustion engine by comparing the calculated rotational fluctuation with a second threshold value smaller than the first threshold value when being output to one side of the gear meshing of the mechanism;
A misfire determination apparatus for an internal combustion engine.   2. The misfire determination device for an internal combustion engine according to claim 1, wherein the second threshold value is set so as to decrease as the predetermined pressing torque increases. A first rotating element of three rotating elements is connected to a multi-cylinder internal combustion engine and a connecting shaft connected to an output shaft of the internal combustion engine via a torsion element, and connected to an axle via a gear mechanism. A planetary gear mechanism in which a second rotating element is connected to the driven drive shaft, a generator connected to the third rotating element of the planetary gear mechanism, and mechanically so as to input and output power to the drive shaft. An internal combustion engine misfire determination method for determining misfire of the internal combustion engine in a hybrid vehicle comprising a connected electric motor, and a power storage means capable of exchanging electric power with the generator and the electric motor,
Detecting the rotational position of the output shaft and calculating the rotational fluctuation of the output shaft for each predetermined rotational angle based on the detected rotational position;
When a braking force greater than a predetermined braking force is applied and the vehicle is stopped, a predetermined pressing torque for suppressing the generation of abnormal noise due to the pulsation of torque output from the internal combustion engine is a gear of the gear mechanism. Determining whether the internal combustion engine has misfired by comparing the rotation variation of the output shaft calculated based on the rotational position of the output shaft and a first threshold value when the electric motor is not outputting to one side of When the predetermined pressing torque is output from the electric motor to one side of the meshing of the gear mechanism, the internal combustion engine is compared by comparing the rotation fluctuation of the output shaft with a second threshold value smaller than the first threshold value. An engine misfire determination method for an internal combustion engine, characterized by determining engine misfire.

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