JP2001041097A - Trouble shooting device for hybrid vehicle and control device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge a misfire of a hybrid vehicle properly. SOLUTION: This trouble shooting device for a hybrid vehicle is provided with a motor and an engine connected thereto. The misfire judging means for judging the misfire of the engine based on the change state (ΔT, ΔNE) of the torque or number of rotation of an engine output shaft changes the accidental fire judging state (judging value, engine control content, etc.), after the restart of the engine based on the change state of the torque or number of rotation after engine start when the combustion operation of the engine is cariied out previously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle failure diagnosis apparatus and a hybrid vehicle control apparatus for determining misfire of an engine.

[0002]

2. Description of the Related Art At present, various hybrid vehicles have been developed. A hybrid vehicle uses an engine and an electric motor as a driving source for driving. For example, the following are known. Japanese Patent Application Laid-Open No. Hei 9-117012 discloses that in such a hybrid vehicle, a generator is connected to an engine, and the generator is operated as an electric motor to increase the engine rotation from a stopped state to a predetermined idling speed. It describes that fuel is supplied to the engine and an ignition operation is started after the engine rotation reaches the idling rotation speed, thereby reducing the occurrence of rattling noise and vibration at the time of starting the engine. Japanese Patent Application Laid-Open No. H09-109694 discloses that in a hybrid vehicle, when the engine is started from an engine stopped state while the vehicle is running, a torque transmitted to a fluctuating output shaft is calculated, and this fluctuation is calculated by an electric motor. Is corrected so as to reduce the fluctuation of the torque finally transmitted to the drive wheels, thereby suppressing the fluctuation of the running interval.

[0003]

In such a hybrid vehicle as well, like a general vehicle, in order to prevent the emission from deteriorating, if an abnormality (including misfire, failure, deterioration, etc.) occurs in the engine, It is anticipated that it will be necessary to inform the occupant of this abnormality promptly so that appropriate action can be taken. On the other hand, in recent years, it has been demanded that the misfire determination of the engine be performed throughout the running of the vehicle. In this case, since the cold start is performed, the fuel vapor (bubbles) in the injector is generated.
It was possible to accurately determine the misfire without being affected by the misfire. However, during a warm start, fuel vapor (bubbles) is stored in the injector and fuel supply pipe.
Is generated, and the output of the engine fluctuates due to the vapor, and a misfire may be erroneously determined to be a misfire due to the vapor. In the case of hybrid vehicles, unlike ordinary vehicles, the frequency of warm starts is high,
It is necessary to prevent erroneous misfire determination caused by this vapor. SUMMARY OF THE INVENTION The present invention has been made in order to respond to a conventional demand, and provides a failure diagnosis apparatus for a hybrid vehicle and a control apparatus for a hybrid vehicle that can appropriately determine a misfire while suppressing the influence of vapor. It is intended to be. Another object of the present invention is to provide a control device for a hybrid vehicle in which the startability is improved without deteriorating fuel efficiency or starting emission.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a failure diagnosis apparatus for a hybrid vehicle including an electric motor and an engine connected to the electric motor, comprising: Or a misfire determination means for performing a misfire determination of the engine based on the fluctuation state of the rotation speed, wherein the misfire determination means determines the torque or the rotation speed after starting the engine when the combustion operation of the engine has been executed previously. The misfire determination state is changed after the engine is restarted based on the fluctuation state.
In the present invention having the above-described configuration, when the misfire determination unit determines the misfire of the engine based on the fluctuation state of the torque or the rotation speed of the engine output shaft, when the combustion operation of the engine has previously been performed. Since the misfire determination status is changed after the engine is restarted based on the fluctuation state of the torque or the number of revolutions after the engine is started, it is possible to perform the misfire determination appropriately by suppressing the influence of the vapor. it can.

In the present invention, the misfire determination status is a misfire determination value, and the misfire determination means sets the determination value larger than the previous determination value when the fluctuation state after the previous engine start is greater than a predetermined value. It is preferable to change the value. The failure diagnosis apparatus for a hybrid vehicle according to the present invention further includes an engine control means, and the misfire determination status is a control content of the engine control means. When the value is larger than the value, it is preferable to change the control content so as to suppress engine misfire more than before. In the present invention, the engine control means is a fuel injection amount control means,
When the fluctuation state after the previous engine start is greater than a predetermined value, it is preferable that the fuel injection amount control means corrects the fuel injection amount at the time of restarting the engine to a larger amount than before.

In the present invention, the engine control means is an ignition timing control means. When the fluctuation state after the previous engine start is greater than a predetermined value, the ignition timing control means controls the ignition timing after the engine is restarted. Is preferably advanced from before. In the present invention, the engine control means is a fuel injection pressure control means. When the fluctuation state after the previous engine start is greater than a predetermined value, the fuel injection pressure control means controls the fuel injection pressure after the engine is restarted. Is preferably compensated for more than before. In the present invention, it is preferable that the misfire determination means changes the misfire determination status when a difference between the related value indicating the engine operating state at restart and the related value indicating the previous engine operating state is within a predetermined range. . In the present invention, it is preferable that the misfire determination means changes the misfire determination status when a time interval from when the engine is stopped to when it is restarted after the previous combustion operation of the engine is within a predetermined range.

In the present invention, the misfire determination means determines that the misfire determination result is normal when the misfire determination result obtained when the misfire determination status is changed is normal even if the misfire determination result is abnormal in the previous start. Is preferred. Further, the present invention is a control device for a hybrid vehicle including an electric motor, an engine connected to the electric motor, and control means for the engine, wherein the control means for the engine has previously performed the combustion operation of the engine. It is characterized in that the control of the engine is changed so as to suppress the misfire based on the fluctuation state of the torque or the number of revolutions after the engine is started. In the present invention configured as described above, the engine control means causes the control of the engine to misfire based on the fluctuation state of the torque or the number of revolutions after the start of the engine when the combustion operation of the engine was previously executed. Since the control is changed so as to suppress the fuel consumption, the startability can be improved without deteriorating the fuel efficiency or the emission at the time of starting.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, a hybrid vehicle to which an embodiment of the present invention is applied will be described with reference to FIGS. FIG. 1 is an overall configuration diagram showing a basic configuration of a hybrid vehicle to which the present embodiment is applied. As shown in FIG. 1, reference numeral 1 denotes a hybrid vehicle. The hybrid vehicle 1 includes a motor 4 driven by electric power supplied from a battery 2 and a liquid fuel such as gasoline as a power unit for generating driving force. The vehicle travels with the engine 6 driven by the explosive force of the vehicle, and travels only with the motor 4, travels only with the engine 6, or travels with the motor 4 and the engine 6 according to the traveling state of the vehicle described later.
Is realized. The engine 6 transmits a driving force to the automatic transmission 12 by engaging the clutch 10 via the torque converter 8. The automatic transmission 12 converts the driving force input from the engine 6 into a predetermined torque and rotation speed in accordance with a traveling state (or by a driver's operation), and converts the driving force through a gear train 14 and a differential mechanism 16. The power is transmitted to the drive wheels 18 and 20. Further, the engine 6 drives the generator / motor 22 as a generator to charge the battery 2. Further, the generator / motor 22 operates as a motor and also operates as a starter of the engine 6. In the present specification, the generator / motor 22 is simply referred to as the motor 22.

The motor 4 is driven by electric power supplied from the battery 2, and is driven by a driving wheel 1 via a gear train 14.
The driving force is transmitted to 8, 20. The engine 6 is mounted, for example, of a type that delays the closing timing of a fuel-efficient valve, the motor 4 is, for example, an IPM synchronous motor, and the battery 2 is mounted, for example, with a nickel hydride battery or a power capacitor. EC, an electronic control unit
The U30 includes a CPU, a ROM, a RAM, an inverter, and controls the ignition timing of the engine 6, the fuel injection amount, and the like, and also controls the output torque and the rotation speed of the motor 4. The ECU 30 generates the electric power generated by the electric motor 22 operating as a generator when the engine 6 operates,
Converter / inverter 24 operating as converter
To the motor 4 or to charge the battery 2. Further, the ECU 30 stores the battery 2
After the electric power collected from the motor 4 and the electric power collected from the motor 4 are adjusted to a predetermined voltage (for example, 100 V) by the inverter 26, the electric power is supplied to the auxiliary equipment motor 28, and the auxiliary equipment 32 is driven.

Next, referring to FIGS. 2 to 7, a description will be given of a driving force transmission mode according to the running state of the hybrid vehicle in the present embodiment. [Starting and Running at Low Speed] As shown in FIG. 2, at the time of starting and running at low speed, the ECU 30 drives only the motor 4,
The driving force of the motor 4 is transmitted to driving wheels 18 and 20 via a gear train 14. In addition, the traveling by the motor 4 is also performed during the low-speed traveling after the start. [Acceleration] As shown in FIG.
Drives both the engine 6 and the motor 4 and transmits the driving force of the engine 6 and the motor 4 to the drive wheels 18 and 20 together. [During steady running] As shown in FIG.
U <b> 30 drives only the engine 6 and transmits driving force from the engine 6 to the drive wheels 18 and 20 via the gear train 14. During steady running, the engine speed is 2000
The vehicle travels in a region with the highest fuel efficiency of about 3000 rpm (see FIG. 17). [During deceleration] As shown in FIG.
Is released, the driving force of the drive wheels 18 and 20 is regenerated to the motor 4 via the gear train 14, the motor 4 serves as a driving source to charge the battery 2, and regenerate to the auxiliary motor 28. The supplied power is supplied.

[During Steady Running and Charging] As shown in FIG. 6, during steady running and charging, the clutch 10 is engaged and the drive wheels 1 are driven from the engine 6 via the gear train 14.
The driving force is transmitted to the motors 8 and 20, the engine 6 drives the electric motor 22 as a generator to charge the battery 2, and the surplus electric power is supplied to the auxiliary motor 28. [At the time of charging] As shown in FIG.
Is released to prevent the driving force from being transmitted from the engine 6 to the automatic transmission 12, and the engine 6 drives the electric motor 22 as a generator to charge the battery 2.

Next, the overall structure of the engine will be described with reference to FIG. As shown in FIG. 8, reference numeral 40 denotes an engine body having a cylinder. An intake port 44 opened and closed by an intake valve and an exhaust port 46 opened and closed by an exhaust valve are opened in a combustion chamber 42 of the cylinder. . An intake passage 48 is connected to the intake port 44, and an exhaust port 46
Is connected to an exhaust passage 64. In the intake passage 48, an air cleaner 50, an air flow sensor 52, a throttle valve 54, and a surge tank 56 are provided in this order from the upstream side, and an injector 58 for injecting fuel is provided near the intake port 44. Further, an IS that bypasses the throttle valve 54 is provided in the intake passage 48.
A C passage 60 is provided, and the ISC passage 60 is provided with an ISC valve 12 that adjusts an air flow rate to execute idle speed control. On the other hand, O
_Two sensors 66 and a catalyst device 68 are provided.

A fuel system for supplying fuel to the injector 58 includes a fuel tank 60, a fuel pump 62, a fuel supply passage 64, and a return passage 66.
Thereby, fuel is sent from the fuel tank 60 to the injector 58 through the fuel supply passage 64. A fuel filter 68 is provided in the fuel supply passage 64. Further, the return passage 66 is provided with a pressure regulator 70 for adjusting the fuel pressure according to the supply pressure. Normally, the pressure regulator 70 maintains a constant pressure difference between the negative pressure introduced into the negative pressure chamber from the downstream portion of the throttle valve 54 in the intake passage 48 and the injection pressure of the fuel injected from the injector 58. With
When a vapor described later is generated, the negative pressure introduced into the negative pressure chamber is shut off by the negative pressure cut valve 72, and the atmospheric pressure is introduced into the negative pressure chamber, thereby increasing the fuel injection pressure. It is configured. That is, the pressure regulator 70 and the negative pressure cut valve 72 constitute an injection state control unit that controls the injection state of the fuel injected from the injector 58.

The engine body 40 is provided with a crank angle sensor 74 for detecting the rotation speed of the crankshaft and a water temperature sensor 76 for detecting the temperature of the cooling water of the engine.
In the air cleaner 50, there is provided intake air temperature detecting means including an intake air temperature sensor 78 for detecting an intake air temperature. The operation state of the injector 58 and the pressure regulator 70 is controlled in accordance with a control signal output from a control unit 80 of the engine. The control unit 80 controls the amount of fuel injected from the injector 58 in accordance with the operating state of the engine, and is connected to the ECU 30 described above.

The ECU 30 includes an injector 58.
There is provided a vapor determining means 82 for determining whether or not the fuel is in a state in which vapor (bubbles) is easily generated. The vapor determination means 82 determines whether at least one of the engine coolant temperature and the intake air temperature detected by the water temperature sensor 76 and the intake air temperature sensor 78 is higher than a predetermined reference temperature, and It is determined that there is a possibility that vapor is generated in a state where vapor is easily generated in the fuel.

Next, referring to FIG. 9, an outline of the failure diagnosis apparatus for a hybrid vehicle according to the present embodiment will be described. FIG. 9 shows the rotation speeds of the engine and the electric motor, the operation of the engine, the misfire monitoring period, and the change period.
First, at the start time t ₁ of the engine 6, the electric motor 22
Operate as an electric motor, that is, a starter, and the rotation speeds of the engine 6 and the electric motor 22 increase from the value at A to the value at B. At this time, at t ₂ , as shown by C, an initial explosion by fuel injection is performed and the engine is started. The timing of starting the engine by this fuel injection is, for example, 10
It is when it becomes 00 rpm or more.

Thereafter, it has been empirically found that the period T ₀ (for example, 5 seconds) from t ₂ to t ₃ is a region where the fluctuation of the engine rotation is large.
No misfire determination is made. Thereafter, misfire determination is performed between t ₃ and t ₄ indicated by D. This period is the misfire monitoring period. Also, after the engine fuel injection starts,
Ie, from t _2, the predetermined period T1 (e.g., 30 seconds), the possibility of vapor generation is a major state. Also, E
At t ₄ when indicated by, the misfire monitoring period ends with the engine operation is completed. Furthermore, t ₃ or later, the next engine operation start, the same operation is repeated.
At this time, the t ₇ shown in F, the predetermined time period, as described later, the misfire determination conditions (the determination value, the engine control content, etc.)
Is changed.

Next, basic control contents of the hybrid vehicle according to the present embodiment will be described with reference to a flowchart shown in FIG. The process shown in this flowchart starts every predetermined period. First, after the start, step S1
, The engine speed _Ne , the accelerator opening, and the vehicle speed V
And other data. Next, in step S2,
Based on the input data, the required torque T for the vehicle
Set _r . Specifically, the required torque _Tr is _{calculated according} to FIG.
1 is set by a map set by the vehicle speed V and the accelerator opening shown in FIG. Next, in step S3, based on the magnitude of the required torque _Tr and the running state of the vehicle,
Set the basic mode shown in. In FIG. 12, when the required torque _Tr (large) is satisfied, the clutch 10 is engaged to operate the engine 6, and when the required torque _Tr cannot be satisfied only by the engine torque, the motor 4 is operated and the electric motor 22 is operated. Operate as an electric motor. When the required torque is _Tr (small), the clutch 10 is released and the motor 4
Only operate. At the time of deceleration, the clutch 10 is released, and the driving force from the driving wheels 18 and 20 is regenerated to the motor 4, and the motor 4 serves as a driving source to charge the battery 2.
When the required torque _Tr = 0 (including a state in which the electric motor 22 is not operating as a generator) and the charge amount of the battery 2 is equal to or less than a predetermined value, in a state where the clutch 10 is released,
The engine 6 drives the electric motor 22 as a generator to charge the battery 2.

After the basic mode is set, step S4
In, target torque amounts (E _Tb , M _Tb , G _Tb ) of the engine 6, the motor 4, and the electric motor 22 are set. In this setting, the required torque T is determined only by the target torque amount E _Tb of the engine.
_{When r} cannot be met, the motor (Tr-E _Tb )
M _Tb is set so as to be satisfied, and if that still cannot be achieved, G _Tb is set so that the motor 22 covers (Tr−E _Tb −M _Tb ). Next, the routine proceeds to step S5, where it is determined whether or not the target torque amount E _Tb of the engine is larger than 0, that is, whether or not it is necessary to start the engine. In the case of YES, the process proceeds to step S6, and it is determined whether or not the flag F ₁ = 0, that is, whether or not the engine is burning. Here, F ₁ = 0 indicates a state in which combustion of the engine is not performed. If F ₁ = 0, that is, if the engine is not burning, the process proceeds to step S7, and the flag F ₂ is set to 1. F ₂ = 1 indicates a state in which the starter control by the electric motor 22 is being performed and the engine is not operating (a period from A to B and C in FIG. 9). Then, the process proceeds to step S8, in order to use the electric motor 22 as a starter, and sets the control quantity G _T value G _S, starts cranking. As shown in FIG. 13, this value G _S gradually increases and is set to a constant value after the engine has completely exploded. At this time, since the engine output cannot be obtained in the clutch released state, step S
Proceeds to 9, configured to bear (E _Tb + G _Tb) partial motor side torque amount M _C of.

Next, if F ₁ = 0 is not satisfied in step S6, that is, if the engine is burning, the flag F ₂ is set to 0 in step S10, and the starter control is stopped. Further, the process proceeds to step S11, the engine rotational speed N _E (= rotational speed N _G of the motor) may determine whether or not a predetermined rotational speed N ₀ than it can engage the clutch, the predetermined rotational speed N ₀
Continuing the starter control returns to step S8 in the following cases, if more than a predetermined rotational speed N _0, the process proceeds to step S12, to set the clutch ON current, to engage the clutch. At this time, the automatic (AT) control amount is changed as shown in FIG.
4 is set. FIG. 14 is a shift map for setting a shift speed based on the target torque amount _Tr and the vehicle speed V.

Next, the routine proceeds to step S13, where the target torque amount E _Tb of the engine is replaced with the final torque amount E _T.
Then, the process proceeds to step S14, and sets the torque fluctuation suppression control amount G _C for performing torque fluctuation suppression control, at step S15, replacing amount of torque of the electric motor (G _Tb + G _C) to the final amount of torque G _T. Here, the torque fluctuation suppression control is performed based on the torque fluctuation of the engine obtained from the signal from the crank angle sensor, as shown in FIG.
The frequency is controlled by the current control of the inverter to cancel the torque fluctuation and reduce the engine torque fluctuation. Next, in step S5, when it is not necessary to start the engine, that is, when only the motor is driven, in steps S16 and S17, the flag F1 and a flag F3 described later are set to 0, and in step S18, the timer T Reset. Next, in Step S19, Step S
Replacing the total amount of torque M _C and the target torque amount M _Tb to bear on the motor side set in 9 to a final torque amount M _T of the motor. Thereafter, the process proceeds to step S20, in which the engine, the motor, the electric motor, and the clutch are driven.

Next, the contents of the engine control according to this embodiment will be described with reference to FIG. The process shown in this flowchart starts at every predetermined crank angle. First, after the start, in step S30, water temperature, O ₂ sensor output O _X , intake air amount Q and the like are input. Next, in step S31, the engine torque amount E _T is not zero, i.e., the necessary starting of the engine. If the engine start is not required, in steps S32 and S33, and resets the flag F ₃ and timer T respectively.

If the engine needs to be started, the process proceeds to step S34, where it is determined whether or not combustion has started. If not started burning, the process proceeds to step S36, the throttle opening degree T _VT, fuel injection amount P _eT, the ignition timing theta _T, respectively, set to a predetermined value for cranking. Step S
If it is determined in step 34 that combustion has started, the process proceeds to step S37, and F ₁ = 1 is set. Next, after step S37, the timer T is counted in step S38. Next, in step S39, the timer T
Is more than a predetermined value T ₀ , specifically, whether a predetermined time (for example, 5 seconds, a period from C to D in FIG. 9) has elapsed. If this predetermined time has not elapsed, a flag F ₃ to 0 and set in step S40, the process proceeds to step S42. If the predetermined time has elapsed, the process proceeds to step S41, and sets 1 and the flag F _3. Next, in step S42, so that the high load as shown in FIG. 17 (high efficiency), set Suruttoru opening T _Vb, the fuel injection amount P _eb, the ignition timing theta _b. Then, the process proceeds to a step S43, wherein the O ₂ sensor output O _X becomes λ = 1.
It is determined whether or not it is equal to or more than the reference value _OX0 . If the determination is NO, the process proceeds to step S44, and the correction amount P _ec = + x of the fuel injection amount is set. If the determination is YES, the process proceeds to step S4.
5, the correction amount P _ec = −x of the fuel injection amount is set, and λ
Feedback control is performed so as to converge to = 1. Next, the process proceeds to step S46, and it is determined whether or not F ₄ = 1. Here, the flag F ₄ is the last (or previous) state vapor by vapor determining means 82 is determined to be likely to have occurred at the time of engine operation, i.e., a possibility is high state of misfire due to vapor generation Is shown. If the possibility of a misfire due to vapor generation is determined to be larger, the process proceeds to step S47, (the water temperature at the time of the previous engine start) temperature T _wsn is T _{w sp} during this engine start ± T _wA
It is determined whether it is within the range of (predetermined value). Further, it is determined whether or not the difference between the time when the engine was stopped before the previous engine start and the time when the engine was stopped before the current engine start is within a predetermined time. This makes it possible to determine whether or not the state of vapor generation is similar between the previous engine start state and the current engine start state. If it is within the range or within a predetermined time, there is a large possibility of misfire due to vapor generation at the current engine start as in the previous case, so that misfire determination is erroneously made by this vapor generation. there is a possibility. Therefore, the process proceeds to step S48, and it is determined whether or not the timer T has passed a predetermined period T ₁ (see FIG. 9). The predetermined period T _1, the possibility of vapor generation is a major period. In step S47, it is determined whether or not the current water temperature is within a predetermined range of the previous water temperature. Instead, the period from the previous stop of the engine to the current start of the engine is within the predetermined period. It may be determined whether or not this is the case.

When the timer T reaches the predetermined period T₁Within
There is a possibility of misjudgment of misfire due to vapor. for that reason,
Proceed to steps S49, S50 and S51 to increase the amount of fuel.
(P _em← α) and increase the fuel pressure (fuel pressure ← A + A)₀),
Further, the ignition timing is advanced (θ_m← −θ_α), To vapor
It is intended to prevent misjudgment of misfire due to this. What
In the present embodiment, steps S49, S50, S51
It is not necessary to execute all the processes of
One of the steps may be performed. Also step
In S46, it is determined that there is no possibility of misfire due to vapor generation
Erroneous determination of misfire by vapor
Proceed to steps S52, S53 and S54.
Only, the fuel injection amount increment (P_em← 0) is set to zero and the fuel pressure
(Fuel pressure ← A) and ignition timing (θ_mThrough each of ← 0)
Set to the usual value. Thus, in step S55
Advance, the final value P of the fuel injection amount_eT , Set, step
In S56, the final value θ of the ignition timing_TSet. Next,
Throttle opening T in step S57_VDrives the throttle valve with
Then, in step S58, control of the fuel pressure is executed, and
In step S59, the fuel injection amount P_eTExecute fuel injection with
Ignition timing θ in step S60_TPerform ignition with.

FIG. 18 is a flowchart showing a process for performing engine control by learning control so as to suppress misfire due to the occurrence of vapor. The flowchart shown in FIG. 18 corresponds to steps S49 to S5 in FIG.
1 to Steps S71 to S77 and Step S71 in FIG.
Steps S78 to S80 are replaced with steps S78 to S80, and steps S81 and S82 are newly inserted between steps S56 and S57 in FIG. Description of the same steps as in FIG. 16 will be omitted, and only different steps will be described. First, step S48 in the previous, if it is determined not to be the determined and the predetermined time period T ₁ has elapsed and there was a possibility that a large state of the misfire from the previous vapor generation, the step S71, step S74, the
In step S77, the fuel injection amount increment (P _em ) is set to a predetermined value (α), and the fuel pressure (F _p ) is increased to a predetermined value (A ₀ ).
The ignition timing (θ _m ) is advanced by a predetermined value (θ _α ), and step S
At 72, the fuel injection amount increment (P _em ) reaches the maximum value (P
When became _EmMAX) above, the fuel injection amount increment (P _em) is be replaced by the maximum value (P _emMAX) at step S73. Further, when the fuel pressure (F _p ) increased in step S75 is equal to or higher than the maximum value (F _pMAX ), the fuel pressure (F _p ) is replaced with the maximum value (F _pMAX ) in step S76. ing.

If there is no possibility of misfiring due to vapor generation, steps S56 to S78, S7
The routine proceeds to 9 and S80, where the fuel injection amount increment (P _em ) is set to 0, and the fuel pressure (F _p ) and the ignition timing (θ _m ) are respectively maintained at the previous values. Further, when the final ignition timing (theta _T) reaches the maximum value (theta _TMAX) or in step S81, the final ignition timing in step S82 (θ _T)
Is replaced with the maximum value (θ _TMAX ). In this manner, the fuel injection amount, the fuel pressure, and the ignition timing are corrected in a stepwise manner, and when each of them is equal to or greater than the maximum value, the fuel injection amount, the fuel pressure, Since engine control is performed by changing the ignition timing to suppress misfire, that is, learning control is performed, the occurrence of misfire due to vapor can be suppressed.

Next, the processing content for the misfire determination will be described with reference to the flowchart shown in FIG. The process shown in this flowchart is performed once in a predetermined time (a period longer than one rotation of the engine). First, in step S100, data required for misfire determination is input. This data is the torque fluctuation (ΔT) of the engine output shaft and the rotation speed fluctuation (ΔN _E ) of the engine, and is detected by the output current of the torque sensor provided on the engine output shaft or the electric motor directly connected to the engine output shaft. You. Next, step S1
At 01, it is determined whether or not F ₁ = 1 (in engine fuel), and at step S102, it is determined whether or not F ₃ = 1 (the period T ₀ (5 seconds) shown in FIG. 9 has elapsed). To do. This is because when the engine is in fuel and the period T ₀ has not elapsed, the misfire determination cannot be performed during this period because the torque fluctuation or the rotation speed fluctuation is large and an accurate misfire determination cannot be performed. It is.
Next, the routine proceeds to step S103, where it is determined whether or not the engine speed fluctuation (ΔN _E ) is smaller than a predetermined value (ΔN _E1 ). Thereby, it is determined whether the vehicle is in a steady running state or another running state such as during acceleration. In the case of acceleration or the like, an accurate misfire determination cannot be made, and a misfire determination can be made only in a steady running state. Therefore, the process proceeds to the next step S104 only in a steady running state. In step S104, a torque variation (ΔT) (that is, a variation in the engine speed (ΔN _E ), more specifically, a variation in the rotational angular speed of the engine) is detected.

Next, the process proceeds to step S105, where F ₄ = 1.
It is determined whether or not (the state where the possibility of misfire was determined to be large due to the previous vapor generation) is present. If YES, the process proceeds to step S106, the timer T judges whether a predetermined time period T ₁ (see FIG. 9) or more. If the predetermined time period T ₁ is elapsed, since there is no possibility of a misfire due to vapor generation, the process proceeds to step S107, sets the threshold value of the torque variation for misfire determining ([Delta] T ₀₎ and the reference value [Delta] T _b. On the other hand, if it is within the predetermined period T ₁ , the possibility of generation of vapor is still large, so the process proceeds to step S108, and this step S108
In, the water temperature T _wsn is T _wsp (water temperature at the time of the previous engine start) at the current engine start is determined whether the range of ± T _wA (predetermined value). If it is within the range, there is a high possibility that misfire will occur due to vapor generation at the present engine start as in the previous case. Therefore, misfire determination may be erroneously made due to this vapor generation. Therefore, the process proceeds to step S109, in which the torque fluctuation threshold (ΔT ₀ ) for misfire determination is increased by ΔT _A to prevent erroneous misfire determination due to vapor generation.

Next, the routine proceeds to step S110, where it is determined whether or not the torque fluctuation (ΔT) is larger than a threshold value (ΔT ₀ ). In step S110, it is determined whether or not the number of times that the torque fluctuation (ΔT) is equal to or larger than the threshold value (ΔT ₀ ) is equal to or greater than a predetermined number. . If it is determined in step S110 that the torque fluctuation (ΔT) is larger than the threshold value (ΔT ₀ ), the process proceeds to step S111, where it is determined that a misfire has occurred, and a misfire abnormality is stored in the memory. Next, step S1
12, when the timer T is determined not to be a predetermined time period T ₁ has elapsed, the process proceeds to step S113, the flag F ₄
Is set to 1. Accordingly, even when the engine is stopped, the flag F ₄ is not reset to zero. On the other hand, if it is determined in step S110 that the torque fluctuation (ΔT) is smaller than the threshold value (ΔT ₀ ), no misfire has occurred, so that it is determined in step S114 that the torque is normal. Then, in step S115, determines whether F ₄ = 1, in the case of YES, the process proceeds to step S116, the water temperature T _wsn is T _wsp (water temperature at the time of the previous engine start during this engine start ) It is determined whether it is within the range of ± T _wA (predetermined value). If it is within the range, there is a high possibility of misfiring due to vapor generation at the current engine start as in the previous case, and thus misfiring determination may be made erroneously due to this vapor generation. Therefore, the process proceeds to step S117, and it is determined whether or not the timer T is equal to or longer than a predetermined period T ₁ (see FIG. 9). If within the predetermined time period T _1, since there is a possibility of misfire due to vapor generation, the process proceeds to step S118, the override and normal misfire abnormality of the previous engine start is (overwriting). Step S115
In the case of YES, the process proceeds to step S119, the F ₄ to 0 and set.

By the processing shown in this flowchart, it is possible to reliably prevent a misfire due to the occurrence of vapor from being erroneously determined to be a misfire. When the engine control shown in FIG. 18 is executed, since the engine control is performed so as to suppress misfire, it is not necessary to perform the processing of steps S111 and S114 in the flowchart shown in FIG. Further, FIG.
In the flowchart shown in ( ₁ ), if the torque fluctuation (ΔT) is equal to or larger than the threshold value (ΔT ₀ ) in step S110, it is determined that a misfire has occurred. In the present embodiment, the misfire is determined to be (large), (medium), or (small) according to the degree of misfire in the misfire due to the generation of vapor, and when the degree of misfire by this vapor is (large), fuel injection is performed. Α ₁
Set to, set the fuel injection amount increasing partial alpha ₂ and in the case of (middle), may be set as the alpha ₃ of the fuel injection amount increment in the case of (small). However, there is a relationship of α ₁ > α ₂ > α ₃ . Similarly, when the degree of misfire due to vapor is (large), the increase in fuel pressure is set to A _01, and when it is (medium), the increase in fuel pressure is set to A _02. However, in the case of (small), the increase in the fuel pressure may be set to A ₀₃ . However, there is a relationship of A ₀₁ > A ₀₂ > A ₀₃ . Furthermore, also the ignition timing, and set the advance angle when the degree of misfire due to vapor (large) - [theta] _{alpha 1} and,
The advance in the case of (middle) set to - [theta] _{alpha 2,} may be set to - [theta] _{alpha 3} the advance in the case of (small). Dadashi, a relationship of _{-θ α 1> -θ α 2>} -θ α 3.

In this way, the operating state of the engine may be changed according to the degree of misfire. Accordingly, it is possible to appropriately change the operating state of the engine this time (that is, remove the influence of the vapor) according to the torque fluctuation (or the rotation speed fluctuation) estimated to be the misfire due to the vapor generation, and determine the misfire. Therefore, the accuracy of misfire determination and the learning accuracy can be improved. Further, in the above embodiment, when the engine is controlled so as to suppress the misfire of the engine, the fuel injection amount is increased, the fuel pressure is increased, and the ignition timing is advanced, but the invention is not limited to this. Alternatively, the swirl may be changed and controlled so as to suppress misfire of the engine, or the injection timing may be changed and controlled when the engine is in direct injection.

[0032]

As described above, according to the failure diagnosis apparatus for a hybrid vehicle and the control apparatus for a hybrid vehicle of the present invention, the misfire determination can be appropriately performed while suppressing the influence of the vapor. Further, according to the hybrid vehicle control device of the present invention, according to the characteristics and deterioration of the engine,
The startability is improved without deteriorating the fuel efficiency or the emission at the start.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a basic configuration of a hybrid vehicle to which an embodiment of the present invention is applied.

FIG. 2 is a configuration diagram showing a driving force transmission mode when the hybrid vehicle starts and runs at a low speed in the embodiment.

FIG. 3 is a configuration diagram showing a transmission form of a driving force during acceleration of the hybrid vehicle according to the embodiment.

FIG. 4 is a configuration diagram illustrating a transmission form of driving force during steady running of the hybrid vehicle according to the present embodiment.

FIG. 5 is a configuration diagram showing a transmission form of a driving force during deceleration of the hybrid vehicle according to the embodiment.

FIG. 6 is a configuration diagram showing a transmission form of driving force during steady running and charging of the hybrid vehicle according to the embodiment.

FIG. 7 is a configuration diagram illustrating a driving force transmission mode during charging of the hybrid vehicle according to the present embodiment.

FIG. 8 is an overall configuration diagram showing the overall structure of the engine of the hybrid vehicle according to the embodiment.

FIG. 9 is a time chart illustrating an outline of a failure diagnosis device for a hybrid vehicle according to the present embodiment.

FIG. 10 is a flowchart showing basic control contents of the hybrid vehicle of the embodiment.

FIG. 11 is a map showing a required torque set based on a vehicle speed and an accelerator opening.

FIG. 12 is a table showing basic modes of a hybrid vehicle.

FIG. 13 is a diagram showing a control amount of a starter when the engine is started.

FIG. 14 is a diagram showing a shift map.

FIG. 15 is a diagram showing torque fluctuation suppression control.

FIG. 16 is a flowchart illustrating engine control according to the present embodiment.

FIG. 17 is a diagram showing a region where a high load (high efficiency) is obtained.

FIG. 18 is a flowchart illustrating another example of engine control according to the present embodiment.

FIG. 19 is a flowchart illustrating processing for misfire determination of the hybrid vehicle according to the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 2 Battery 4 Motor 6 Engine 10 Clutch 22 Electric motor 24 Converter / inverter 30 ECU

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 41/22 301 F02D 41/22 330Z 330 43/00 301A 43/00 301 301H B60K 9/00 E (72 ) Inventor Kenji Morimoto 3-1, Fuchu-machi, Shinchi, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Akihiro Kobayashi 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda F-term (reference) 3G084 AA00 BA13 BA14 BA17 CA01 DA27 DA28 EA07 EA11 EB06 EB08 EB12 EB22 EC01 EC03 FA24 FA32. PI11 PI16 PI22 PI29 PI30 PO02 PO06 PO17 PU10 PU22 PU24 PU25 PV09 QE01 QE02 QE08 QE10 QE12 QH01 QI04 QN03 QN06 QN09 QN12 RB08 RE02 RE03 RE05 RE06 RE07 RE13 SE04 SE05 SE08 TB01 TE02 TE03 TE05 TE06 TE08 TO04 TO12 TO22 TO30 TU20

Claims (10)

[Claims] 1. A failure diagnosis device for a hybrid vehicle including an electric motor and an engine connected to the electric motor, wherein a misfire determination of the engine is performed based on a fluctuation state of torque or rotation speed of an engine output shaft. The engine has a misfire judging means. The misfire judging means has a misfire judging condition after the engine is restarted, based on a fluctuation state of the torque or the number of revolutions after the engine was started when the combustion operation of the engine was previously executed. A failure diagnosis device for a hybrid vehicle, wherein 2. The misfire determination status is a misfire determination value, and the misfire determination means sets the determination value larger than the previous determination value when the fluctuation state after the previous engine start is greater than a predetermined value. The failure diagnosis device for a hybrid vehicle according to claim 1, wherein the failure diagnosis device changes the value to a value. 3. The engine control means according to claim 1, wherein said misfire determination status is a control content of said engine control means, and said engine control means is provided when the fluctuation state after the previous engine start is larger than a predetermined value. The failure diagnosis device for a hybrid vehicle according to claim 1, wherein the control content is changed so as to suppress engine misfire more than before. 4. The engine control means is a fuel injection amount control means, and when the fluctuation state after the previous engine start is greater than a predetermined value, the fuel injection amount control means is provided for restarting the engine. 4. The failure diagnosis device for a hybrid vehicle according to claim 3, wherein the fuel injection amount of the hybrid vehicle is increased and corrected. 5. The engine control means is an ignition timing control means, and the ignition timing control means, when the fluctuation state after the previous engine start is larger than a predetermined value,
4. The failure diagnosis apparatus for a hybrid vehicle according to claim 3, wherein the ignition timing after the restart of the engine is advanced from before. 6. The engine control means is a fuel injection pressure control means. When the fluctuation state after the previous engine start is greater than a predetermined value, the fuel injection pressure control means is provided after the engine is restarted. 4. The failure diagnosis apparatus for a hybrid vehicle according to claim 3, wherein the fuel injection pressure of the hybrid vehicle is increased and corrected. 7. The misfire determination means determines the misfire determination status when a difference between a related value indicating the engine operating state at the restart and the related value indicating the previous engine operating state is within a predetermined range. The failure diagnosis device for a hybrid vehicle according to claim 1, wherein the failure diagnosis device is changed. 8. The hybrid according to claim 1, wherein said misfire determination means changes said misfire determination status when a time interval from when the engine is stopped to when it is restarted after a previous engine combustion operation is within a predetermined range. Vehicle failure diagnosis device. 9. When the misfire determination result obtained when the misfire determination status is changed is normal, the misfire determination means determines that the misfire determination result is normal even if the misfire determination result is abnormal in the previous start. The failure diagnosis device for a hybrid vehicle according to claim 1, wherein the determination is performed. 10. A control device for a hybrid vehicle, comprising: an electric motor, an engine connected to the electric motor, and control means for the engine, wherein the control means for the engine executes the combustion operation of the engine before. A control device for a hybrid vehicle, wherein the control of the engine is changed so as to suppress a misfire based on a fluctuation state of the torque or the rotation speed after the engine is started.