JP2010048141A - Misfire determination device and misfire determination method for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately determine the misfire of a multiple cylinder internal combustion engine of which output shaft is connected to a rear stage shaft in a rear stage through a torsional element. <P>SOLUTION: A misfire determination device calculates an influence component Nde(CA) (S210-S240) by using damper rear stage rotation speed Nd(CA) at a rear stage of a damper calculated from motor rotation speeds Nm1(CA), Nm2(CA), and engine rotation speed Ne(CA), sets engine rotation speed Ne as execution rotation speed Nj(CA) (S270) if engine rotation speed Ne is less than a prescribed rotation speed Nref and fuel injection to an engine is not executed, and sets a rotation speed obtained by subtracting the influence component Nde from engine rotation speed Ne as an execution rotation speed Nj(CA) if the engine rotation speed Ne is not less than the prescribed rotation speed Nref or fuel injection to the engine is executed. Then the misfire of the engine is determined by using the execution rotation speed Nj(CA). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an internal combustion engine misfire determination device and a misfire determination method thereof, and more particularly, to an internal combustion engine misfire that determines the misfire of a multi-cylinder internal combustion engine having an output shaft connected to a subsequent stage shaft via a torsion element. The present invention relates to a determination device and a misfire determination method for an internal combustion engine that determines the misfire of the internal combustion engine.

Conventionally, this type of internal combustion engine misfire determination device is an output from a motor to cancel engine torque fluctuation in a vehicle that performs vibration suppression control to cancel engine torque fluctuation by a motor connected to the crankshaft of the engine. There has been proposed a method for calculating a torque correction amount to be detected and detecting an engine misfire state based on the calculated torque correction amount (see, for example, Patent Document 1). With this technology, even when vibration suppression control is not being performed or when vibration suppression control is being performed, misfires can be caused based on crankshaft rotation fluctuations when the engine is operating at a high load and high rotation. When the engine is operated at a low load or at a low speed, misfire is detected based on the torque correction amount output from the motor for the calculated vibration suppression control.
JP 2001-65402 A

  By the way, in the misfire determination device that determines misfire of the internal combustion engine in which the output shaft is connected to the subsequent stage shaft via a torsion element such as a damper, the torque fluctuation of the output shaft due to the explosion combustion of the internal combustion engine is caused by the twist of the torsion element Since the induced torsion of the torsional element further causes the rotational fluctuation of the internal combustion engine, misfire of the internal combustion engine cannot be accurately detected based on the rotational fluctuation of the internal combustion engine. In particular, when starting or stopping the internal combustion engine, the effect of the twist of the torsion element on the rotation fluctuation of the internal combustion engine as a result of inducing the resonance of the torsion element when the rotational speed of the internal combustion engine passes through the resonance frequency region of the torsion element. It is necessary to respond appropriately in such cases.

  The misfire determination device for an internal combustion engine and the misfire determination method according to the present invention are mainly intended to more accurately determine the misfire of a multi-cylinder internal combustion engine whose output shaft is connected to the rear shaft of the rear stage via a torsion element. To do.

  The misfire determination device and the misfire determination method of the internal combustion engine 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 misfire determination device for an internal combustion engine that determines misfire of an internal combustion engine having a plurality of cylinders, the output shaft of which is connected to the rear shaft of the rear stage via a torsion element,
Output shaft rotational speed detection means for detecting an output shaft rotational speed that is the rotational speed of the output shaft;
A rear shaft rotational speed detection means for detecting a rear shaft rotational speed which is the rotational speed of the rear shaft;
Based on the difference between the detected output shaft rotational speed and the detected subsequent shaft rotational speed, the torsion angle of the torsion element is calculated, and the calculated torsion angle, the spring constant of the torsion element, and the torsion element An influence component calculating means for calculating an influence component that the torsion of the torsion element affects the rotation speed of the output shaft based on the inertia moment on the internal combustion engine side;
While the internal combustion engine is being started or while the operation of the internal combustion engine is being stopped, when the detected output shaft rotational speed is less than a predetermined rotational speed and fuel is injected into the internal combustion engine. When the predetermined fuel cut is not occurring, the detected output shaft rotational speed is set as the execution rotational speed, and when not during the predetermined fuel cut, the calculated influence component is calculated from the detected output shaft rotational speed. An execution speed setting means for setting the rotation speed obtained by subtraction as an execution speed;
Misfire determination means for determining misfire of the internal combustion engine based on the set fluctuation component of the engine speed for execution;
It is a summary to provide.

  In the misfire determination apparatus for an internal combustion engine according to the present invention, when the output shaft rotational speed is less than a predetermined rotational speed while the internal combustion engine is being started or while the operation of the internal combustion engine is being stopped, The detected output shaft rotational speed is set as the execution rotational speed at the time of predetermined fuel cut when fuel injection is not performed. Further, when it is not at the time of the predetermined fuel cut, the rotation speed obtained by subtracting the influence component that the twist of the torsion element affects the rotation speed of the output shaft from the detected output shaft rotation speed is set as the execution rotation speed. Then, the misfire of the internal combustion engine is determined based on the fluctuation component of the execution rotational speed set in this way. As described above, since the output shaft rotational speed is set as the execution rotational speed as it is when the predetermined fuel is cut, it is possible to suppress the influence of the twisting of the torsion element at the time of the predetermined fuel cut from acting after the end of the predetermined fuel cut. be able to. That is, it is possible to eliminate the influence of resonance caused by a relatively low rotation at the time of starting or stopping the operation of the internal combustion engine or the influence based on unstable rotation from the subsequent misfire determination. As a result, misfire of the internal combustion engine can be determined with higher accuracy.

  In such a misfire determination apparatus for an internal combustion engine of the present invention, the influence component calculation means calculates the twist angle based on an integral calculation of a value obtained by subtracting the detected subsequent shaft rotational speed from the detected output shaft rotational speed. The influence component may be calculated based on an integral calculation obtained by multiplying a constant relation value that is a relation between the spring constant and the moment of inertia by the torsion angle.

  Further, in the misfire determination device for an internal combustion engine of the present invention, the influence component calculation means does not attenuate the resonance frequency on the rear stage side including the torsion element in the calculated influence component, and other than the resonance frequency. The band may be a means for performing a filter process to attenuate and calculating the influence component. In this way, it is possible to attenuate the band other than the resonance frequency having a large influence from the influence component in which the twist of the torsion element affects the rotation speed of the output shaft. Therefore, misfire of the internal combustion engine can be determined with higher accuracy. Here, the filtering process may use a high-pass filter.

The misfire determination method of the internal combustion engine of the present invention,
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,
Based on the torsion angle of the torsion element, the spring constant of the torsion element, and the moment of inertia on the internal combustion engine side from the torsion element, an influential component that affects the rotation speed of the output shaft is calculated. The fuel injection to the internal combustion engine is performed when the detected output shaft rotational speed is less than a predetermined rotational speed while starting the internal combustion engine or while the operation of the internal combustion engine is stopped. The detected output shaft rotational speed is set as the execution rotational speed when the predetermined fuel cut is not being performed, and when it is not the predetermined fuel cut, the calculated influence component is calculated from the detected output shaft rotational speed. Is set as the engine speed for execution, and misfiring of the internal combustion engine is determined based on the fluctuation component of the engine speed for execution set. And

  In the misfire determination method for an internal combustion engine of the present invention, when the output shaft rotational speed is less than a predetermined rotational speed while the internal combustion engine is being started or while the operation of the internal combustion engine is being stopped, The detected output shaft rotational speed is set as the execution rotational speed at the time of predetermined fuel cut when fuel injection is not performed. Further, when it is not at the time of the predetermined fuel cut, the rotation speed obtained by subtracting the influence component that the twist of the torsion element affects the rotation speed of the output shaft from the detected output shaft rotation speed is set as the execution rotation speed. Then, the misfire of the internal combustion engine is determined based on the fluctuation component of the execution rotational speed set in this way. As described above, since the output shaft rotational speed is set as the execution rotational speed as it is when the predetermined fuel is cut, it is possible to suppress the influence of the twisting of the torsion element at the time of the predetermined fuel cut from acting after the end of the predetermined fuel cut. be able to. That is, it is possible to eliminate the influence of resonance caused by a relatively low rotation at the time of starting or stopping the operation of the internal combustion engine or the influence based on unstable rotation from the subsequent misfire determination. As a result, 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. 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. A motor MG1 capable of generating electricity connected to the power distribution and integration mechanism 30, a reduction gear 35 attached to the ring gear shaft 32a connected to the power distribution and integration mechanism 30, and a motor MG2 connected to the reduction gear 35; And a hybrid electronic control unit 70 for controlling the entire vehicle. Here, the misfire determination device for the internal combustion engine of the embodiment mainly corresponds to an engine electronic control unit 24, a crank position sensor 140, a motor electronic control unit 40, rotational position detection sensors 43 and 44, which will be described later.

  The engine 22 is configured as an eight-cylinder internal combustion engine that can output power by using a hydrocarbon fuel such as gasoline or light oil. As shown in FIG. 2, 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 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 receives signals from various sensors that detect the state of the engine 22, the crank position (crank angle CA) from the crank position sensor 140 that detects the rotational position (crank angle CA) of the crankshaft 26, and the engine 22. Cooling water temperature from a water temperature sensor 142 that detects the temperature of the cooling water, intake valve 128 that performs intake and exhaust to the combustion chamber, cam position from the cam position sensor 144 that detects the rotational position of the camshaft that opens and closes the exhaust valve, and throttle valve The throttle position from the throttle valve position sensor 146 for detecting the position 124, the air flow meter signal AF from the air flow meter 148 attached to the intake pipe, the intake air temperature from the temperature sensor 149 also attached to the intake pipe, and the air-fuel ratio Air-fuel ratio AF from capacitors 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. Further, 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 above-described crank position sensor 140 is mounted so as to rotate in synchronization with the crankshaft 26, and teeth are formed every 10 degrees and two missing teeth are formed for detecting the reference position. It is configured as an electromagnetic pickup sensor having a rotor, and generates a shaped wave every time the crankshaft 26 rotates 10 degrees. The engine ECU 24 calculates the number of revolutions of the engine 22 as the number of revolutions Ne of the engine 22 based on the shaped wave from the crank position sensor 140 every time the crankshaft 26 rotates 30 degrees.

  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 carrier shaft 34 a connected to the carrier 34 is decelerated via the damper 28, the crankshaft 26 of the engine 22, the sun gear 31 is motor MG 1, and the ring gear 32 is decelerated via the ring gear shaft 32 a. When gears 35 are connected and motor MG1 functions as a generator, power from engine 22 input from carrier 34 is distributed to sun gear 31 side and ring gear 32 side according to the gear ratio, and motor MG1 When functioning as an electric motor, the power from 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 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 rotational position detection sensors 43 and 44 are configured by a resolver, and the motor ECU 40 motors MG1 and MG2 at predetermined time intervals (for example, every 50 μsec or every 100 μsec) based on signals from the rotational position detection sensors 43 and 44. The rotation speeds Nm1 and Nm2 are calculated.

  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 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, 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 a required torque to be output to the ring gear shaft 32a based on the accelerator opening Acc and the vehicle speed V corresponding to the amount of depression of the accelerator pedal 83 by the driver. The operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the 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 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 and 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, 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 misfire determination process executed by the engine ECU 24. This routine is repeatedly executed every predetermined time.

  When the misfire determination process is executed, the CPU 24a of the engine ECU 24 first inputs the execution speed Nj (CA) (step S100), and uses the input execution speed Nj (CA) to input the crankshaft. A 30-degree rotation required time T30 (CA) required for 26 to rotate 30 degrees is calculated by the following equation (1) (step S110). The execution rotational speed Nj (CA) is a rotational speed set based on the rotational speed Ne of the engine 22 and the influence component Nde based on the torsion of the damper 28. The execution rotational speed calculation process illustrated in FIG. Calculated. For ease of explanation, the calculation process of the execution rotational speed Nj (CA) will be described later.

  T30 (CA) = (30/360) / Nj (CA) (1)

  Subsequently, the difference between the required rotation times T30 (ATDC30) and T30 (ATDC90) 30 degrees after the top dead center of the compression stroke of the cylinder subject to misfire determination (ATDC30) and 90 degrees (ATDC90) [T30 (ATDC30) −T30 (ATDC90)] is calculated as the required time difference TD30 (step S120), and the difference from the value calculated as the required time difference TD30 360 degrees before the calculated required time difference TD30 (the required time difference TD30). 360 degrees difference) [TD30−TD30 (360 degrees before)] is calculated as a determination value J30 (step S130), and the calculated determination value J30 is compared with a threshold value Jref (step S140). When it is larger than the threshold value Jref, it is determined that the target cylinder has misfired (step S150), and misfire determination is performed. Exit sense, the cylinders of the subject when determining value J30 is equal to or smaller than the threshold Jref ends the determined misfire determination process that no misfire. Here, the required time difference TD30 is negative if the cylinder is normally combusted (exploded) from the degree of acceleration of the piston 132 due to combustion (explosion) of the engine 22 when considered from the angle from the compression top dead center. If the cylinder is misfired, it becomes a positive value. Therefore, the determination value J30 is a value near 0 if the target cylinder is normally burned (exploded), and the required time difference of the cylinder that is normally burning if the target cylinder is misfired. It becomes a positive value larger than the absolute value of TD30. Therefore, by setting the threshold value Jref as a value close to the absolute value of the required time difference TD30 of a normally burning cylinder, misfiring of the target cylinder can be accurately determined.

  Next, the calculation process of the execution rotation speed Nj (CA) will be described. In the calculation process of the execution speed Nj (CA), as shown in the execution speed calculation process of FIG. 4, the CPU 24a of the engine ECU 24 first sets the crank angle CA and the engine 22 rotation speed every 30 degrees of the crank angle. Ne (CA), the rotational speeds Nm1 (CA) and Nm2 (CA) of the motors MG1 and MG2, and the fuel injection flag F are input (step S200). Here, the fuel injection flag F is set to a value of 1 when fuel injection to the engine 22 is performed by a fuel injection control routine (not shown) executed by the engine ECU 24, and fuel injection to the engine 22 is performed. When there is no value, the value 0 is set and the value written at a predetermined address in the RAM 24c is read and input. Next, the input rotation speeds Nm1 (CA) and Nm2 (CA) of the motors MG1 and MG2, the gear ratio ρ of the power distribution and integration mechanism 30 (the number of teeth of the sun gear / the number of teeth of the ring gear), and the gear ratio Gr of the reduction gear 35 Is used to calculate the rotation speed Nd (CA) of the damper 28 on the side of the power distribution and integration mechanism 30 side, that is, the rotation speed of the carrier shaft 34a according to the following equation (2) (step S210). Here, regarding the rotational speed Ne (CA) of the engine 22, the crank angle CA of the rotational speed Ne of the engine 22 calculated each time the crankshaft 26 rotates 30 degrees based on the shaped wave from the crank position sensor 140. The rotation speeds Nm1 (CA) and Nm2 (CA) of the motors MG1 and MG2 are input based on signals from the rotation position detection sensors 43 and 44, and the crank angle CA is calculated. Those corresponding to the above are input from the motor ECU 40.

  Nd (CA) = [Nm2 (CA) / Gr + ρ ・ Nm1 (CA)] / (1 + ρ) (2)

  Subsequently, the torsion angle θd (CA) of the damper 28 is calculated by the following equation (3) using the rotation speed Ne (CA) of the engine 22 and the calculated rear-stage rotation speed Nd (CA) of the damper (step S220). Using the constant relationship value (K / J), which is the ratio between the spring constant K of the damper 28 and the moment of inertia J on the engine 22 side from the damper 28, and the calculated twist angle θd (CA), the torsion of the damper 28 is A noise-containing influence component Nden (CA) including low-frequency noise is calculated by the expression (4) as an influence on the rotation speed of the (step S230).

θd (CA) = ∫ [Ne (CA) -Nd (CA)] dt (3)
Nden (CA) = (K / J) ・ ∫θd (CA) dt (4)

  Then, in order to remove the low-frequency noise of the noise-containing influence component Nden (CA), a high-pass filter is applied to the noise-containing influence component Nden (CA) to calculate the influence component Nde (CA) (step S240). Here, for the high-pass filter, the cut-off frequency may be set so as not to attenuate the resonance frequency band of the damper 28 but to attenuate the lower frequency band. By applying such a high-pass filter, it is possible to remove the low-frequency component accumulated by the integral calculation according to the above-described equations (3) and (4).

  Next, it is determined whether or not the rotational speed Ne of the engine 22 is equal to or higher than the predetermined rotational speed Nref (step S250). When the rotational speed Ne of the engine 22 is less than the predetermined rotational speed Nref, the fuel injection flag F is further set. It is determined whether or not the value is 0 (step S260). Here, the predetermined rotation speed Nref can be set as a value higher than the resonance frequency region of the damper 28 (for example, a value such as 600 rpm or 700 rpm). When the rotational speed Ne of the engine 22 is less than the predetermined rotational speed Nref and the fuel injection flag F is 0 (that is, when fuel injection to the engine 22 is not performed), the rotational speed Ne of the engine 22 is executed. The rotational speed Nj (CA) is set (step S270), and this routine is terminated. On the other hand, when the rotational speed Ne of the engine 22 is equal to or higher than the predetermined rotational speed Nref, or when the fuel injection flag F is 1 even when the rotational speed Ne of the engine 22 is less than the predetermined rotational speed Nref (that is, fuel to the engine 22). When injection is being performed), a value obtained by subtracting the influence component Nde from the rotational speed Ne of the engine 22 is set to the execution rotational speed Nj (CA) (step S280), and this routine is terminated. As described above, when the rotational speed Ne of the engine 22 is less than the predetermined rotational speed Nref and fuel is being injected into the engine 22, the rotational speed Ne of the engine 22 is set as the execution rotational speed Nj (CA) as it is. To do. When starting the engine 22 or stopping operation, when the rotational speed Ne of the engine 22 is relatively low, especially when passing through the resonance frequency region of the damper 28, the damper 28 is induced to resonate. The value of the influence component Nde (CA) in which the twist of 28 affects the rotational speed Ne of the engine 22 may also increase. Therefore, the value obtained by subtracting the influence component Nde (CA) from the rotational speed Ne of the engine 22 is also obtained when the rotational speed Ne of the engine 22 is less than the predetermined rotational speed Nref and fuel is being injected into the engine 22. When the engine speed Nj (CA) for execution is set, the influence component Nd (CA) calculated when the engine 22 is started or when the operation is stopped is not changed until the fuel is injected into the engine 22. Since the rotational speed Ne of the engine 22 becomes equal to or higher than the predetermined rotational speed Nref, the engine speed 22 may affect the execution speed Nj (CA) and the misfire of the engine 22 may not be accurately determined. On the other hand, in the embodiment, when the rotational speed Ne of the engine 22 is less than the predetermined rotational speed Nref and when fuel injection to the engine 22 is performed, the rotational speed Ne of the engine 22 is used as it is for the execution rotational speed Nj. Since (CA) is set, the influence component Nde (CA) when the rotational speed Ne of the engine 22 is less than the predetermined rotational speed Nref and the fuel injection to the engine 22 is performed is the fuel injection to the engine 22. It is possible to prevent the engine 22 from acting on the engine speed Nj (CA) after the engine speed Ne reaches the predetermined engine speed Nref or more. As a result, misfire of the engine 22 can be determined with higher accuracy.

  According to the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment described above, when the rotational speed Ne of the engine 22 is less than the predetermined rotational speed Nref and fuel injection to the engine 22 is not performed, the engine 22 Is set as the execution speed Nj (CA). When the engine speed Ne is equal to or higher than the predetermined engine speed Nref or when fuel is being injected into the engine 22, the engine speed Ne. Is set as the execution speed Nj (CA), and the rotation speed obtained by subtracting the influence component Nde that the twist of the damper 28 affects the rotation speed of the engine 22 is set, and the execution speed Nj (CA) thus set is set. Since the misfire of the engine 22 is determined based on the determination value J30 as the fluctuation component, the rotational speed Ne of the engine 22 is equal to the predetermined rotational speed Nr. When the rotational speed Ne of the engine 22 becomes equal to or higher than the predetermined rotational speed Nref due to the influence of the twist of the damper 28 when the fuel injection to the engine 22 is not performed when it is less than f, the rotational speed Ne of the engine 22 is predetermined. Even if the rotational speed is less than Nref, it is possible to prevent the fuel from being injected into the engine 22 from affecting the execution rotational speed Nj (CA). That is, the influence of resonance of the damper 28 that occurs at a relatively low speed when the engine 22 is started or stopped and the influence based on unstable rotation can be excluded from the subsequent misfire determination. As a result, the misfire of the engine 22 can be determined with higher accuracy regardless of the influence of resonance of the damper 28 or the influence based on unstable rotation when the engine 22 is started or stopped.

  Further, according to the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment, the calculation is performed when the influence component Nde (CA) in which the twist of the damper 28 affects the rotational speed Ne of the engine 22 is calculated. Since the high-pass filter for attenuating a band other than the resonance frequency of the damper 28 is applied to the noise-containing influence component Nden (CA), the influence component due to the resonance of the damper 28 is excluded from the rotational speed Ne of the engine 22 to improve the engine accuracy. 22 misfires can be determined.

  According to the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment, when the rotational speed Ne of the engine 22 is equal to or higher than the predetermined rotational speed Nref or when fuel is being injected into the engine 22, The torsion angle θd (CA) of the damper 28 is calculated from the rotation speed Ne (CA) and the damper rear rotation speed Nd (CA) on the rear stage side of the damper 28, and the spring constant K of the damper 28 and the constant relation value (K / J). ) And the torsion angle θd (CA), the noise-containing influence component Nden (CA) is calculated, and the influence component Nde (CA) is calculated by performing high-pass filter processing on the noise-containing influence component Nden (CA). The torsion angle θd of the damper 28 is calculated based on the difference between (CA) and the post-damper rotational speed Nd (CA), and the calculated torsion angle θd and the spring constant of the damper 28 are calculated. Any calculation method can be used as long as the influence component Nde (CA) in which the torsion of the damper 28 affects the rotational speed Ne of the engine 22 is calculated based on the inertia moment J on the engine 22 side from the damper 28. But you can. Further, the noise-containing influence component Nden (CA) may be subjected to high-pass filter processing and the influence component Nde (CA) may not be calculated.

  According to the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment, the damper 28 can be operated even when the rotational speed Ne of the engine 22 is less than the predetermined rotational speed Nref and fuel is not injected into the engine 22. The torsion angle θd, the noise-containing influence component Nden (CA), and the influence component Nde (CA) are calculated. However, such values may not be calculated.

  According to the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment, the damper subsequent stage rotational speed Nd is calculated from the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2, but the rotational speed sensor is applied to the carrier shaft 34a. And the rotation speed of the carrier shaft 34a may be directly detected to obtain the post-damper rotation speed Nd.

  According to the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment, the 30-degree rotation time T30 (CA) is obtained from the execution speed Nj (CA), and the top dead center of the compression stroke of the target cylinder. The required time difference TD30 is calculated as the difference between the required rotation times T30 (ATDC30) and T30 (ATDC90) 30 degrees after 30 degrees (ATDC30) and 90 degrees (ATDC90). Although the determination value J30 is calculated to determine the misfire of the engine 22, the misfire of the engine 22 is determined by any calculation method as long as the misfire of the engine 22 is determined using the execution speed Nj (CA). It does n’t matter what you do.

  According to the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment, the misfire of any cylinder of the 8-cylinder engine 22 is determined, but the misfire of any cylinder of the 6-cylinder engine is determined. Any number of cylinders can be used as long as it can determine the misfire of any cylinder of a multi-cylinder engine. I do not care.

  According to the misfire determination device for an internal combustion engine mounted on the hybrid vehicle 20 of the embodiment, it is connected to the crankshaft 26 of the engine 22 via the damper 28 as a torsion element and to the rotating shaft of the motor MG1 and the ring gear shaft 32a. It is assumed that the misfire of the engine 22 in the vehicle including the power distribution and integration mechanism 30 and the motor MG2 connected to the ring gear shaft 32a via the reduction gear 35 is determined, but the engine crankshaft is a damper as a torsion element. Therefore, as illustrated in the hybrid vehicle 120 of the modified example of FIG. 5, the power of the motor MG2 is driven by the axle (drive wheels 63a, 63b) to which the ring gear shaft 32a is connected. Connected to the wheels 64a and 64b in FIG. May alternatively determine the misfire of the engine 22 used to connect to the axle) was. 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.

  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 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”, and each time the crankshaft 26 rotates 30 degrees based on a crank position sensor 140 that detects the rotational position of the crankshaft 26 and a shaped wave from the crank position sensor 140. The engine ECU 24 that calculates the rotational speed of the engine 22 as the rotational speed Ne (CA) of the engine 22 corresponds to “output shaft rotational speed detection means”, and rotational position detection sensors 43 and 44 that detect the rotational position of the rotors of the motors MG1 and MG2. The motor ECU 40 that calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the signals from the rotational position detection sensors 43 and 44, and the carrier downstream of the damper 28 based on the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2. Damper post-rotation speed Nd (C The engine ECU 24 that executes the process of step S210 of FIG. 3 corresponds to the “rear shaft rotational speed detecting means”, and calculates the rotational speed Ne (CA) of the engine 22 and the rear rotational speed Nd (CA) of the damper. Is used to calculate the torsion angle θd of the damper 28 and the constant relation value (K / J), which is the ratio between the spring constant K of the damper 28 and the moment of inertia J on the engine 22 side from the damper 28, and the torsion angle θd. A noise-containing influence component Nden (CA) including low-frequency noise is calculated as an effect on the rotational speed of the engine 22 due to the twist of the damper 28, and further, the low-frequency noise is removed by a high-pass filter to calculate the influence component Nde (CA). The engine ECU 24 that executes the processing of steps S220 to S240 in FIG. 4 corresponds to “influence component calculation means”, and the engine 22 rotates. When Ne is less than the predetermined rotation speed Nref and fuel is not injected into the engine 22, the rotation speed Ne (CA) of the engine 22 is set as the execution rotation speed Nj (CA), and the rotation speed Ne ( When CA) is equal to or higher than the predetermined rotational speed Nref or when fuel is being injected into the engine 22, the influence component Nde that the twist of the damper 28 affects the rotational speed of the engine 22 is reduced from the rotational speed Ne of the engine 22. The engine ECU 24 that executes the processing of steps S250 to S280 of FIG. 4 for setting the obtained rotation speed as the execution rotation speed Nj (CA) corresponds to the “execution rotation speed setting means”, and the execution rotation speed Nj (CA ) Is used to calculate the 30-degree rotation required time T30 (CA) required for the crankshaft 26 to rotate 30 degrees and is subject to misfire. The difference between the required time T30 (ATDC30) and T30 (ATDC90) 30 degrees after the top dead center of the cylinder compression stroke (ATDC30) and 90 degrees (ATDC90) [T30 (ATDC30)-T30 (ATDC90)] Is calculated as the required time difference TD30, and the difference from the value calculated as the required time difference TD30 360 degrees before the calculated required time difference TD30 (360 degree difference of the required time difference TD30) [TD30−TD30 (360 degrees before) )] As a determination value J30 and the misfire determination process of FIG. 3 for determining misfire corresponds to the “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 “output shaft rotational speed detection means” is limited to the one that calculates the rotational speed every time the crankshaft 26 rotates 30 degrees based on the shaped wave from the crank position sensor 140 as the rotational speed Ne (CA) of the engine 22. However, any method may be used as long as it detects the output shaft rotation speed, which is the rotation speed of the output shaft. As the “rear shaft rotational speed detection means”, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are calculated based on signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2. Based on the calculated rotation speeds Nm1 and Nm2 of the motors MG1 and MG2, it is limited to the one that calculates the damper rear-stage rotation speed Nd (CA) as the rotation speed of the rear-stage carrier shaft 34a (corresponding to the rear-stage shaft) of the damper 28. Instead of detecting the rotation speed of the rear shaft, which is the rotation speed of the rear shaft, such as a rotation speed sensor mounted on the carrier shaft 34a and directly detecting the rotation speed of the carrier shaft 34a to obtain the rear rotation speed Nd of the damper. Anything can be used. As the “influence component calculating means”, the torsion angle θd of the damper 28 is calculated using the rotational speed Ne (CA) of the engine 22 and the post-damper rotational speed Nd (CA), and the spring constant K of the damper 28 and the damper 28 are calculated. Using a constant relation value (K / J) that is a ratio to the moment of inertia J on the engine 22 side and the torsion angle θd, noise including low-frequency noise is included as an effect on the rotational speed of the engine 22 due to the twist of the damper 28 It is not limited to the calculation of the influence component Nden (CA) and further the calculation of the influence component Nde (CA) by removing the low-frequency noise by the high-pass filter, and the detected output shaft rotation speed is detected. The torsion angle of the torsion element is calculated based on the difference from the rotational speed of the rear shaft, and the calculated torsion angle, the spring constant of the torsion element, and the torsion element Any component may be used as long as it calculates an influence component that the torsion of the torsion element affects the rotation speed of the output shaft based on the inertia moment on the internal combustion engine side. As the “execution speed setting means”, when the engine speed Ne is less than the predetermined engine speed Nref and fuel is not being injected into the engine 22, the engine speed Ne (CA) is executed. The number Nj (CA) is set, and when the rotational speed Ne (CA) of the engine 22 is equal to or higher than the predetermined rotational speed Nref or when fuel is injected into the engine 22, the twist of the damper 28 is determined from the rotational speed Ne of the engine 22. Is not limited to setting the rotation speed obtained by subtracting the influence component Nde that affects the rotation speed of the engine 22 as the execution rotation speed Nj (CA), but during starting the internal combustion engine Alternatively, when the output shaft rotational speed detected while the operation of the internal combustion engine is stopped is less than a predetermined rotational speed, and fuel is injected into the internal combustion engine. When the predetermined fuel cut is not occurring, the detected output shaft rotational speed is set as the execution rotational speed, and when it is not the predetermined fuel cut, the calculated influence component is subtracted from the detected output shaft rotational speed. As long as the rotation speed obtained is set as the rotation speed for execution, any value may be used. As the “misfire determination means”, the required rotation speed Nj (CA) is used to calculate the time required for 30-degree rotation T30 (CA) required for the crankshaft 26 to rotate 30 degrees, and for the cylinder subject to misfire. The difference [T30 (ATDC30) −T30 (ATDC90)] between the required rotation times T30 (ATDC30) and T30 (ATDC90) 30 degrees after the top dead center of the compression stroke (ATDC30) and 90 degrees (ATDC90) is required. Calculated as the time difference TD30, and the difference from the value calculated as the required time difference TD30 360 degrees before the calculated required time difference TD30 (360 degree difference of the required time difference TD30) [TD30-TD30 (360 degrees before)] Is determined as a determination value J30 and misfire is not determined, but the top dead center (TDC) of the compression stroke of each cylinder. And the difference [T30 (TDC) −T30 (ATDC60)] between the required time T30 (TDC) and T30 (ATDC60) of 30 ° rotation 60 degrees after the top dead center (ATDC60) and calculated as the required time difference TD30. The difference from the value calculated as the required time difference TD30 360 degrees before the required time difference TD30 (360 degree difference of the required time difference TD30) [TD30−TD30 (360 degrees before)] is calculated as the determination value J30. Any method can be used as long as the misfire of the internal combustion engine is determined based on the set fluctuation component of the rotational speed for execution, such as determining misfire. 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.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a misfire determination device for an internal combustion engine and a vehicle manufacturing industry including the same.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 equipped with an internal combustion engine combustion state determination apparatus according to an embodiment of the present invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. It is a flowchart which shows an example of a misfire determination process. It is a flowchart which shows an example of the rotational speed calculation process for execution. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification.

Explanation of symbols

  20,120 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 24a CPU, 24b ROM, 24c RAM, 26 crankshaft, 28 damper, 30 power distribution integrated mechanism, 31 sun gear, 32 ring gear, 32a ring gear Shaft, 33 Pinion gear, 34 Carrier, 34a Carrier shaft, 35 Reduction gear, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 battery, 51 Temperature sensor, 52 For 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 CP U, 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, 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, MG1, MG2 motor.

Claims (5)

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,
Output shaft rotational speed detection means for detecting an output shaft rotational speed that is the rotational speed of the output shaft;
A rear shaft rotational speed detection means for detecting a rear shaft rotational speed which is the rotational speed of the rear shaft;
Based on the difference between the detected output shaft rotational speed and the detected subsequent shaft rotational speed, the torsion angle of the torsion element is calculated, and the calculated torsion angle, the spring constant of the torsion element, and the torsion element are calculated. An influence component calculating means for calculating an influence component that the torsion of the torsion element affects the rotation speed of the output shaft based on the inertia moment on the internal combustion engine side;
While the internal combustion engine is being started or while the operation of the internal combustion engine is being stopped, when the detected output shaft rotational speed is less than a predetermined rotational speed and fuel is injected into the internal combustion engine. When the predetermined fuel cut is not occurring, the detected output shaft rotational speed is set as the execution rotational speed, and when not during the predetermined fuel cut, the calculated influence component is calculated from the detected output shaft rotational speed. An execution speed setting means for setting the rotation speed obtained by subtraction as an execution speed;
Misfire determination means for determining misfire of the internal combustion engine based on the set fluctuation component of the engine speed for execution;
A misfire determination apparatus for an internal combustion engine.   The influence component calculating means calculates the torsion angle based on an integral calculation of a value obtained by subtracting the detected rear shaft rotational speed from the detected output shaft rotational speed, and calculates the spring constant and the moment of inertia. 2. The misfire determination apparatus for an internal combustion engine according to claim 1, which is means for calculating the influence component based on an integral calculation of a constant relation value which is a relation multiplied by the twist angle.   The influence component calculating means performs a filtering process for attenuating a band other than the resonance frequency without attenuating the calculated resonance component including the torsional element, and attenuating a band other than the resonance frequency. The misfire determination apparatus for an internal combustion engine according to claim 1 or 2, which is means for calculating   The internal combustion engine misfire determination apparatus according to claim 3, wherein the filter process is a process using a high-pass filter. 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,
Based on the torsion angle of the torsion element, the spring constant of the torsion element, and the moment of inertia on the internal combustion engine side from the torsion element, an influential component that affects the rotation speed of the output shaft is calculated. The fuel injection to the internal combustion engine is performed when the detected output shaft rotational speed is less than a predetermined rotational speed while starting the internal combustion engine or while the operation of the internal combustion engine is stopped. When the predetermined fuel cut is not occurring, the detected output shaft rotational speed is set as the execution rotational speed, and when it is not the predetermined fuel cut, the calculated influence component is calculated from the detected output shaft rotational speed. Is set as the engine speed for execution, and misfiring of the internal combustion engine is determined based on the fluctuation component of the engine speed for execution set. A misfire determination method for an internal combustion engine.

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