JP2002339774A - Control device for hybrid vehicle - Google Patents

Abstract

(57) [Summary] In a control device for a hybrid vehicle, drivability is improved by suppressing a shock during acceleration during deceleration. SOLUTION: When a fuel cut condition for the engine 11 is satisfied at the time of deceleration of the vehicle and the regeneration by the electric motor 29 is performed, the amount of intake air to the engine 11 is increased, and when a return condition from the fuel cut is satisfied. In addition, while controlling the intake air amount to be the target intake air amount, supplying fuel to the engine 11 and controlling the fuel injection amount so as to reach the target air-fuel ratio, only for a predetermined number of strokes after returning from the fuel cut. changes the target air-fuel ratio to the lean side with torque reduction coefficient K _T.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a control device for a hybrid vehicle having an engine and a motor.

[0002]

2. Description of the Related Art In recent years, hybrid vehicles using an engine and a motor as drive sources, which suppress generation of exhaust gas due to global environmental problems, have been put to practical use. In such a hybrid vehicle, the driving wheels are driven only by driving the motor, or the driving wheels are driven by driving both the motor and the engine, depending on the driving state. The motor can be driven by the electric power stored in the battery. When the energy of the battery decreases, the engine is driven to charge the battery.

[0003] Such a hybrid vehicle has a system for regenerating energy during traveling. This regenerative system stops the engine when the vehicle decelerates, regulates the power supply to the motor, and controls the power supply to the motor. Is switched to a power generation state. A load is applied to the driving wheel to brake the same, and the rotational energy of the driving wheel is recovered as electric energy. In this case, while the fuel supply to the engine is cut off, the throttle is fully opened to increase the amount of intake air, thereby reducing the pump loss, thereby improving the regenerative efficiency.

[0004]

However, in such a conventional hybrid vehicle control device, when the vehicle decelerates and the motor is under regenerative control, the driver tries to accelerate by pressing the accelerator pedal. Then, the throttle in the fully opened state is closed to a predetermined opening degree. In this case, since the residual air is present due to the volume of the intake pipe, the intake air amount becomes more than necessary due to the response delay of the air. Also,
To properly manage the fuel injection amount and improve exhaust gas performance, fuel efficiency, and combustion stability, rather than directly determine the fuel injection amount from the operating state, calculate the target air-fuel ratio once from the operating state and set the target air-fuel ratio. It is better to determine the fuel injection amount from the air-fuel ratio and the intake air amount. In other words, if the fuel injection amount is directly determined from the operating state, the air-fuel ratio changes greatly depending on the amount of intake air, and the out-of-combustibility range and the exhaust gas performance deteriorate. However, when the target air-fuel ratio is determined from the operating state, the fuel injection amount is determined so as to be the target air-fuel ratio according to the intake air amount, so that the above-described problem can be prevented. On the other hand, since the engine torque is determined by the fuel injection amount set in accordance with the intake air amount, the fuel injection amount increases in accordance with the increase in the intake air amount. Occurs,
There is a problem that drivability is deteriorated by the acceleration shock.

FIG. 7 is a graph showing a change in the operating state of the engine during acceleration during deceleration by the conventional hybrid vehicle control device. It is to be noted that the dotted line in FIG. 6 is a case where the throttle is not fully opened at the time of fuel cut. As can be seen from the graph of FIG. 7, when the deceleration operation of the hybrid vehicle is confirmed by, for example, turning off the accelerator pedal (accelerator opening APS = 0), the control device performs fuel cut (fuel injection pulse width Pw = 0). And the throttle is fully opened to increase the volumetric efficiency Ev,
Regeneration efficiency is improved by reducing pump loss. When the driver depresses the accelerator pedal from this state, the accelerator opening APS increases, while the throttle is closed and the volume efficiency Ev is immediately reduced to a predetermined value, but the volume efficiency is reduced due to the residual air due to the intake pipe volume. The reduction of Ev to a predetermined value is delayed, the pulse width Pw of fuel injection sharply increases, and an excessive wheel torque is generated to cause an acceleration shock.

Japanese Patent Application Laid-Open No. H11-182276 discloses a technique in which fuel injection is delayed when the hybrid vehicle returns from a fuel cut in a decelerating state. Insufficient torque may occur in the initial stage of vehicle acceleration and drivability may deteriorate. Japanese Patent Application Laid-Open No. 2000-186589 discloses a hybrid vehicle that switches to a compression lean mode in which the hybrid vehicle is operated at a lean air-fuel ratio when the engine is started. When used for the control at the time of returning from the fuel cut in the vehicle, there is a possibility that the output may become insufficient when the operating state at the time of the return, particularly when the degree of acceleration request is large.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a control device for a hybrid vehicle which improves drivability by suppressing a shock during acceleration during deceleration.

[0008]

According to a first aspect of the present invention, there is provided a control apparatus for a hybrid vehicle, wherein a fuel cut condition for the engine is satisfied at the time of deceleration and the engine is regenerated when the motor is regenerated. Intake air amount control means for controlling the amount of intake air to be increased in such a manner that the amount of intake air becomes a target intake air amount set in accordance with the operating state when a condition for returning from the fuel cut is satisfied. A fuel injection amount control means for supplying fuel to the engine and controlling the fuel injection amount so as to attain a target air-fuel ratio set according to the operating state; and a target air-fuel ratio when a condition for returning from the fuel cut is satisfied. Target air-fuel ratio changing means for changing the fuel ratio to the lean side is provided.

Therefore, when the fuel is cut and the motor is regenerated when the vehicle is decelerated, the amount of intake air is increased, so that the pump loss is reduced and the regenerative efficiency is improved. On the other hand, when the vehicle accelerates from the deceleration state and returns from the fuel cut, the fuel injection amount is controlled so as to be the target intake air amount and the target air-fuel ratio, but by changing the target air-fuel ratio to the lean side, Since the amount of fuel decreases while supplying fuel promptly, the engine does not generate excessive torque due to a delay in air response. No, drivability is improved.

In the control apparatus for a hybrid vehicle according to the second aspect of the present invention, when a driver's acceleration request is detected,
The condition for returning from the fuel cut is satisfied.
Therefore, when the driver is requesting acceleration, it is possible to quickly shift to the acceleration state and reduce the acceleration shock.

In the control apparatus for a hybrid vehicle according to a third aspect of the present invention, the target air-fuel ratio changing means includes a request torque calculated based on a driver's acceleration request and an estimated torque calculated from an operating state of the engine. The target air-fuel ratio is calculated based on the target air-fuel ratio, and the target air-fuel ratio is made leaner as the estimated torque is larger than the required torque. Therefore, it is possible to finely control the torque when returning from the fuel cut, and it is possible to prevent an excessive or insufficient torque suppression amount.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic configuration of a hybrid vehicle according to an embodiment of the present invention, FIG. 2 is a control block of a control device of the hybrid vehicle of the embodiment, and FIG. 3 is a torque by the control device of the hybrid vehicle of the embodiment. A flowchart of the suppression determination control, FIG. 4 is a flowchart of the torque suppression control by the hybrid vehicle control device of the present embodiment, FIG. 5 is a map for obtaining the torque suppression coefficient, and FIG. 5 is a graph showing a change in the operating state of the engine at the time of acceleration in FIG.

In the hybrid vehicle according to the present embodiment,
As shown in FIG. 1, the mounted engine 11 is, for example, an in-cylinder injection engine that directly injects fuel into a combustion chamber, and includes a stoichiometric mode, an intake lean mode, a compression lean mode, an open loop mode, The mode can be switched to the cut mode.

In the engine 11, a spark plug 12 and an injector 13 are attached to a cylinder head for each cylinder, an injection port of the injector 13 is opened in a combustion chamber 15 formed above a piston 14, and fuel is supplied to the combustion chamber. 1
5 is directly injected. An intake port 16 and an exhaust port 17 facing the combustion chamber 15 are formed in the cylinder head. The intake port 16 is opened and closed by an intake valve 18, and the exhaust port 17 is opened and closed by an exhaust valve 19. The engine 11 is provided with a crank angle sensor 20 that outputs a crank angle signal at a predetermined crank position of each cylinder. The crank angle sensor 20 can detect the engine speed. Furthermore, the intake port 16
An air cleaner 22 is attached to the air intake, and an electronic control throttle valve 23 and a throttle position sensor 2 are connected to the intake pipe 21.
4 is mounted, and an air flow sensor 25 is mounted upstream of the throttle valve 23. On the other hand, an exhaust pipe 26 is connected to the exhaust port 17.

The crankshaft 27 of the engine 11 thus configured is connected to an electric motor 29 via a transmission clutch 28.
The transmission clutch 28 can be driven by an actuator 31 operated by a hydraulic drive device (not shown). The electric motor 29 is drivable by receiving power supply from the battery 32, and is capable of charging the battery 32 by generating power by receiving driving force from the engine 11.

The output shaft 30 of the electric motor 29 is CVT
33. In the CVT 33, an endless steel belt is wound around a pair of variable V-shaped pulleys (not shown), the rotation shaft of one variable V-type pulley is connected to the input shaft 30 on the input side, and the other variable V-type pulley is connected. Is connected to an output shaft 34 on the output side, and the width of each variable V-shaped pulley is changed by supply and discharge of hydraulic pressure to change the pulley ratio, so that the engine 11 and the electric motor 29 The transmitted torque can be continuously adjusted through a pair of variable V-shaped pulleys and a steel belt and transmitted to the output shaft 34. The output shaft 34 of the CVT 33 is connected to a differential gear 36 via a start clutch 35. The start clutch 35 can be driven by an actuator 36 operated by a hydraulic drive device (not shown). The amount of torque transmitted to the left and right drive wheels 38 can be adjusted.

The vehicle is provided with an electronic control unit (ECU) 39 for controlling the engine 11, the electric motor 29, the CVT 33 and the like. The ECU 39 stores input / output devices, control programs and control maps. , A central processing unit, a timer and counters, and the ECU 39 controls the in-cylinder injection engine 11 comprehensively. That is, the crank angle sensor 20 and the throttle position sensor 2
4. In addition to the air flow sensor 25, detection information of various sensors such as a position sensor 40 of an accelerator pedal depressed by a driver, a signal of an ignition key switch 42 is input to the ECU 39, and the ECU 39 performs detection based on the detection information of the various sensors. Fuel injection mode, fuel injection amount,
The ignition timing and the like are determined, and the ignition plug 12, the injector 1
8 and the drive motor of the throttle valve 23 and the like.

A charge capacity of the battery 32 detected by a battery capacity sensor (not shown) is input to the ECU 39, and the electric motor 2 is controlled according to the charge capacity of the battery 32.
9 is controlled. Further, as described above, the CVT 33 has a hydraulic drive circuit for changing the width of the pair of variable V-type pulleys, and the ECU 39 controls the hydraulic drive circuit to change the pulley ratio and change the gear ratio. To change the settings. The control of the actuators 31 and 37 of the transmission clutch 28 and the starting clutch 35 is also performed by the ECU.
39 is to do.

In the control device for a hybrid vehicle constructed as described above, the position sensor 40 of the accelerator pedal is used.
Torque RT required by the vehicle based on the accelerator opening APS detected by the vehicle and the vehicle speed V detected by the vehicle speed sensor 41
Q is set, and the target motor torque MTQ is set based on the required torque RTQ and the state of charge SOC of the battery 32, while the target engine torque ETQ is set by subtracting the target motor torque MTQ from the required torque RTQ. . Further, the rotation speed at which the engine has the best fuel efficiency is set from the target engine torque ETQ and the engine rotation speed Ne, and is output as the target primary rotation speed Np of the CVT 33. The ECU 39 then sets the engine 11 and the electric motor 2 based on the set target motor torque MTQ, target engine torque ETQ, and target primary rotational speed Np.
By controlling the CVT 9 and the CVT 33, the hybrid vehicle runs as required by the driver.

The control device for a hybrid vehicle according to the present embodiment has a system for regenerating energy during traveling, and stops the engine 11 when the vehicle decelerates and regulates power supply to the electric motor 30. The electric motor 30 is switched to a power generation state, a load is applied to the drive wheel 38 to brake the same, and the rotational energy is recovered as electric energy and stored in the battery 32. In this case, while the fuel supply to the engine 11 is cut off, the throttle valve 23 is fully opened to increase the amount of intake air, and the pump loss is reduced, thereby improving the regenerative efficiency. However, when the driver depresses the accelerator pedal to accelerate while the vehicle is decelerating and the electric motor 30 is regenerating, the throttle valve 23 in the fully open state is closed to reduce the intake air amount. The target intake air amount cannot be immediately set due to the response delay, and the intake air amount is large, so that the fuel injection amount increases, causing an excessive torque in the engine and an acceleration shock.

Therefore, in the control device for a hybrid vehicle according to the present embodiment, the ECU 39 determines that the fuel cut condition for the engine 11 is satisfied when the vehicle decelerates and the electric motor 29
When the regenerative braking is performed, the intake air amount to the engine 11 is controlled to increase, and when the condition for returning from the fuel cut is satisfied, the intake air amount is set according to the operating state. (Intake air amount control means), while supplying fuel to the engine 11 and controlling the fuel injection amount so as to attain a target air-fuel ratio set in accordance with the operation state (fuel injection amount control means). However, when the condition for returning from the fuel cut is satisfied, the target air-fuel ratio is changed to a lean side (target air-fuel ratio changing means).

Hereinafter, in the engine control of the ECU 39 in the control device for a hybrid vehicle according to the present embodiment described above, a method for setting a fuel injection amount based on detection information of various sensors and a method for changing when returning from a fuel cut will be described. This will be described in detail using two control blocks.

As shown in FIG. 2, the above-mentioned target engine torque ETQ is converted into a unit of a net average effective pressure Pe (required torque), and the friction Pf is added to obtain the indicated average effective pressure Pi. On the other hand, the volume efficiency Ev is obtained by dividing the intake air amount AFS detected by the air flow sensor 25 by the engine speed Ne detected by the crank angle sensor 20. If the operating state of the engine 11 is the compression lean mode, the engine speed Ne and the indicated mean effective pressure Pi are displayed.
The target air-fuel ratio (A / F) coefficient K _{A / F} is obtained from the map of the following equation. In the open loop (O / L) mode, the target air-fuel ratio coefficient K _A is obtained from the map of the volumetric efficiency Ev and the indicated mean effective pressure Pi. _{Find A / F.} Thereafter, the value obtained by mass-converting the volume efficiency Ev is multiplied by the obtained target air-fuel ratio coefficient K _{A / F} to obtain SB1
The block multiplies various coefficients and injector gains and adds a dead time to obtain a reference fuel injection pulse width Pw1.
Is calculated.

Further, based on the engine speed Ne and the reference fuel injection pulse width Pw1, the estimated net average effective pressure Pe1 is calculated.
(Estimated torque). Here, in the in-cylinder injection type engine, all the fuel injected from the injector contributes to the combustion by the above-described configuration, so that the transfer delay of the fuel generated in the normal intake pipe injection type engine and the fuel adhesion to the port are caused. Can be eliminated. Therefore, in the direct injection engine, it is easy to obtain the estimated torque from the reference fuel injection pulse width.

On the other hand, based on the brake mean effective pressure Pe as the required torque and the estimated brake mean effective pressure Pe1 as estimated torque obtaining a torque reduction coefficient K _T. This torque suppression coefficient K _T is set from a map set based on the relationship between the required torque (net average effective pressure Pe) and the estimated torque (estimated net average effective pressure Pe1) as shown in FIG. That is, if the required torque ≧ the estimated torque, the torque suppression coefficient K _T = 1.0, and if the estimated torque is larger than the required torque, the torque suppression coefficient K _T = 0.7, 0.5,.
3 are set to be small.

Then, the target air-fuel ratio coefficient K _{A / F} is multiplied by the torque suppression coefficient K _T to obtain a correction coefficient K. After clipping the lower limit set for each of the intake injection and the compression injection, the volume efficiency Ev is calculated by the mass. The converted value is multiplied by a correction coefficient K, and SB
In the two blocks, various coefficients and injector gains are multiplied and the dead time is added, and the corrected fuel injection pulse width P
Calculate w2. Then, an estimated net average effective pressure Pe2 is obtained based on the engine speed Ne and the corrected fuel injection pulse width Pw2. The reference fuel injection pulse width Pw1 and the estimated net average effective pressure Pe2 are used for the gear ratio control of the CVT 33 by the ECU 39.

The reference fuel injection pulse width Pw1 and the corrected fuel injection pulse width Pw2 thus determined are switched according to the operating state of the engine 11 (Pw1 ≧ Pw2). That is,
In normal operation, the switch 18a of the injector 18 is switched to the reference fuel injection pulse width Pw1, and the injector 18 injects fuel based on the reference fuel injection pulse width Pw1. On the other hand, the switch 18a of the injector 18 sets the corrected fuel injection pulse width Pw2 only during a predetermined number of strokes after returning from the fuel cut due to the deceleration of the vehicle to the fuel cut due to the acceleration.
And the injector 18 injects fuel based on the corrected fuel injection pulse width Pw2. That is, the fuel injection amount is reduced for a predetermined number of strokes after returning from the fuel cut to the normal operation, and the target air-fuel ratio is changed to a lean side.

Next, a method of suppressing the engine torque by the ECU 39 in the control device for a hybrid vehicle according to the present embodiment will be described with reference to the flowcharts of FIGS.

In the engine torque suppression determination control, as shown in FIG. 3, it is determined in step S11 whether or not a fuel cut due to deceleration of the vehicle is being executed. = 0,
Even during the fuel cut, if the throttle valve 23 is not open in step S13, FLAG = 0 is set. On the other hand, if the fuel is being cut in step S11 and the throttle valve 23 is open in step S13, FLAG = 1 is set in step S14.

In the engine torque suppression control, as shown in FIG. 4, first, in step S21, a net average effective pressure Pe (target engine torque ETQ) as an engine required torque is determined based on the vehicle speed V and the accelerator opening APS. decide. Next, in step S22, the intake air amount AFS
The reference fuel injection pulse width Pw1 is determined based on the target air-fuel ratio coefficient KA _{/ F.} In step S23, an estimated net average effective pressure Pe1 as an estimated torque is obtained from the reference fuel injection pulse width Pw1.

In step S24, it is determined whether or not FLAG = 1, that is, the throttle valve 2 is in the fuel cut state.
It is determined whether or not 3 is open. This step S2
If FLAG is not 1 in step 4, it is determined that the throttle valve 23 is not open even during the fuel cut and during the fuel cut. In step S25, the fuel injection pulse width Pw by the injector 18 is set to the reference fuel injection pulse width Pw1. age,
After setting FLAG = 0 in step S26, step S2
At 7, the injector 18 sets the reference fuel injection pulse width Pw1
Inject fuel based on

On the other hand, if FLAG = 1 in step S24, it is determined that the throttle valve 23 is open during fuel cut, and in step S28, it is determined whether or not return from the fuel cut is within a predetermined number of strokes. . In this case, if the vehicle is decelerating and the fuel is cut off, the process proceeds to step S25 and the same processing as described above is performed. On the other hand, in step S28, if the vehicle returns from the fuel cut state to the normal operation due to the driver's acceleration request during the deceleration of the vehicle and is within the predetermined number of strokes,
Move to step S29.

In step S29, a torque suppression coefficient K _T is obtained based on the required torque (net average effective pressure Pe) and the estimated torque (estimated net average effective pressure Pe1). In step S30, the reference fuel injection pulse width Pw1 is corrected based on the torque suppression coefficient K _T to correct the corrected fuel injection pulse width Pw1.
Determine w2. Then, in step S31, the fuel injection pulse width Pw by the injector 18 is set to the corrected fuel injection pulse width Pw2, and in step S27, the injector 1
Numeral 8 injects fuel based on the corrected fuel injection pulse width Pw2.

After that, after the injector 18 injects the fuel based on the corrected fuel injection pulse width Pw2, a predetermined time elapses, and in step S28, when returning from the fuel cut and exceeding a predetermined number of strokes, the flow proceeds to step S25. Then, the fuel injection pulse width Pw of the injector 18 is returned to the reference fuel injection pulse width Pw1, and after setting FLAG = 0 in step S26, the injector 18 injects fuel based on the reference fuel injection pulse width Pw1 in step S27.

As described above, in the control device for a hybrid vehicle according to the present embodiment, when the fuel cut condition for the engine 11 is satisfied at the time of deceleration of the vehicle and the regeneration by the electric motor 29 is performed, the amount of intake air to the engine 11 is increased. On the other hand, when the condition for returning from the fuel cut is satisfied, the intake air amount is controlled to be the target intake air amount, the fuel is supplied to the engine 11, and the fuel injection amount is adjusted to the target air-fuel ratio. control to, but only between a predetermined stroke number after the fuel cut operation changes the target air-fuel ratio to the lean side with torque reduction coefficient K _T.

Therefore, when the vehicle is decelerated and the fuel is cut to perform regeneration by the electric motor 29, the amount of intake air increases, so that pump loss is reduced and regeneration efficiency is improved. On the other hand, when the vehicle accelerates from the deceleration state and returns from the fuel cut, the target air-fuel ratio is changed to the lean side, so that the engine 11 does not generate excessive torque.
While suppressing the acceleration shock of the vehicle, the shortage of torque at the initial stage of acceleration can be eliminated.

That is, as can be seen from the graph of FIG.
When the deceleration operation of the hybrid vehicle is confirmed by turning off the accelerator pedal (accelerator opening APS = 0), etc.
CU39 is fuel cut (pulse width of fuel injection Pw = 0)
At the same time, the throttle valve 23 is fully opened to increase the volumetric efficiency Ev, reduce the pump loss and improve the regenerative efficiency. When the driver depresses the accelerator pedal from this state, the accelerator opening APS increases, while the throttle is closed and the volume efficiency Ev is immediately reduced to a predetermined value, but the volume efficiency is reduced due to the residual air due to the intake pipe volume. It is delayed that Ev decreases to the predetermined value. However, within a predetermined number of strokes after returning from the fuel cut, the target air-fuel ratio is corrected to the lean side, so that the pulse width Pw of the fuel injection increases smoothly, no excessive wheel torque is generated, and acceleration shock is suppressed. Is done.

It should be noted, in the embodiment described above, ECU 39 has been determined torque reduction coefficient K _T based on the estimated net mean effective pressure Pe1 as estimated torque and brake mean effective pressure Pe as the required torque, the engine 11 Required torque ETQ
The torque suppression coefficient K _T may be calculated based on the estimated torque and the estimated torque. The indicated average effective pressure P as the required torque
The torque suppression coefficient K _T may be obtained based on i and the estimated indicated mean effective pressure Pi1 as the estimated torque.

[0040]

As described in detail in the above embodiment, according to the control apparatus for a hybrid vehicle of the first aspect, the target air-fuel ratio is changed to the lean side when the condition for returning from the fuel cut is satisfied. Since the target air-fuel ratio changing means is provided, when the motor is regenerated as a fuel cut when the vehicle is decelerated, the amount of intake air increases, so that the pump loss can be reduced and the regeneration efficiency can be improved. When the vehicle is accelerated from the deceleration state and returns from the fuel cut, the target intake air amount and the target air-fuel ratio are changed to a lean side, so that the fuel amount decreases while supplying the fuel promptly. The engine does not generate excessive torque due to the delay and suppresses the acceleration shock of the vehicle. Utility can be improved.

According to the control apparatus for a hybrid vehicle of the second aspect of the present invention, the condition for returning from the fuel cut is satisfied when the driver's request for acceleration is detected. In this case, the vehicle can be quickly shifted to the acceleration state, and the acceleration shock can be reduced.

According to the control device for a hybrid vehicle of the third aspect, the target air-fuel ratio changing means calculates the required torque calculated based on the driver's acceleration request and the estimated torque calculated from the operating state of the engine. The target air-fuel ratio is calculated based on the target air-fuel ratio, and the target air-fuel ratio is made leaner as the estimated torque is larger than the required torque, so that the torque when returning from the fuel cut is finely controlled. It is possible to prevent an excessive or insufficient torque suppression amount.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present invention.

FIG. 2 is a control block diagram of a control device for a hybrid vehicle according to the present embodiment.

FIG. 3 is a flowchart of torque suppression determination control by the hybrid vehicle control device according to the embodiment;

FIG. 4 is a flowchart of torque suppression control performed by the hybrid vehicle control device according to the embodiment.

FIG. 5 is a map for obtaining a torque suppression coefficient.

FIG. 6 is a graph showing a change in an operating state of an engine during acceleration during deceleration by the control device for a hybrid vehicle according to the present embodiment.

FIG. 7 is a graph showing a change in an operating state of an engine during acceleration during deceleration by a conventional hybrid vehicle control device.

[Explanation of symbols]

Reference Signs List 11 engine 13 injector 20 crank angle sensor 23 electronic control throttle valve 24 throttle position sensor 25 air flow sensor 29 electric motor 33 CVT 39 electronic control unit, ECU (intake air amount control means, fuel injection amount control means, target air-fuel ratio changing means) 40 Accelerator position sensor 41 Vehicle speed sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B60L 11/14 F02D 41/10 305 F02D 41/10 305 310 310 310 330J 330 41/12 310 41/12 310 330J 330 45/00 364A 45/00 364 B60K 9/00 E (72) Inventor Takashi Kawabe 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation F-term (reference) 3G084 BA05 BA09 BA13 CA04 CA06 DA11 FA05 FA10 FA38 3G093 AA06 AA07 BA02 CA05 CB06 DA06 DA09 DB05 EA04 EA05 EA06 EA09 FA11 FA12 FB02 3G301 HA01 JA04 KA15 LA03 LB01 MA01 MA11 MA25 NE15 PA01Z PA11Z PF01Z PF03Z 5H115 PA01 PG04 PU01 PU02 PO17 TE04 TE06

Claims (3)

[Claims] In a hybrid vehicle having an engine and a motor, when a fuel cut condition for the engine is satisfied at the time of deceleration and a regeneration is performed by the motor, control is performed in a direction to increase an intake air amount to the engine. And intake air amount control means for controlling the intake air amount to a target intake air amount set in accordance with an operation state when a condition for returning from the fuel cut is satisfied, and supplying fuel to the engine. A fuel injection amount control means for controlling a fuel injection amount so as to attain a target air-fuel ratio set according to an operation state, and changing the target air-fuel ratio to a lean side when a condition for returning from the fuel cut is satisfied. And a target air-fuel ratio changing means. 2. The hybrid vehicle control device according to claim 1, wherein the condition for returning from the fuel cut is satisfied when a driver's acceleration request is detected. 3. The hybrid vehicle control device according to claim 1, wherein the target air-fuel ratio changing unit calculates a required torque calculated based on a driver's acceleration request and an estimated torque calculated from an operating state of the engine. And calculating the degree of change of the target air-fuel ratio based on the target air-fuel ratio, wherein the target air-fuel ratio is made leaner as the estimated torque is larger than the required torque.