JP3972905B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle control apparatus, and more particularly, to a hybrid vehicle capable of reducing fuel consumption by extending a fuel cut time during deceleration of a hybrid vehicle that performs an assist operation by a motor generator connected to an engine. The present invention relates to a control device.

  Recently, a hybrid vehicle including an engine and a motor generator capable of driving and assisting the engine has been proposed for the purpose of improving fuel efficiency. In the hybrid vehicle, the drive and assist of the motor generator are controlled by the control device.

  The control device of the hybrid vehicle operates to regenerate power by operating the motor generator as a generator at the time of deceleration, and controls to recover the kinetic energy as electric energy, and assists the driving force of the engine by the motor generator at the time of acceleration. Is controlling. In addition, the hybrid vehicle control device controls the engine to stop in the idling state without operating the ignition key, and rotates the crankshaft with a motor generator when engine power is required. Drive and control to restart the engine. Further, the control device for the hybrid vehicle controls to regenerate the motor generator while stopping the fuel supply at the time of deceleration and cutting the fuel, and resumes the fuel supply when the engine rotational speed falls below the set rotational speed. There is something to control.

Such a hybrid vehicle control device prohibits automatic engine stop until the vehicle speed reaches a predetermined vehicle speed after the vehicle starts, and after reaching the predetermined vehicle speed, the shift position is in a non-traveling range (P or N range). Or when the brake pedal is depressed in the travel range (D range), by prohibiting the restart of fuel supply following the fuel cut, There is one that saves fuel by extending the engine stop time as much as possible.
Japanese Patent Laid-Open No. 11-257121

Further, as a control device for a hybrid vehicle, a fuel cut is performed at the time of deceleration, and after the fuel cut starts, the motor generator is operated in a power generation mode until the engine rotation speed decreases to a rotation speed near the target idle rotation speed, and the engine When the rotational speed drops to a rotational speed close to the target idle rotational speed, the motor generator is switched to the electric mode to prevent engine stall and expand the fuel cut region, after which the engine rotational speed converges to the idle rotational speed. In some cases, fuel supply is started at a stable point and the output torque of the motor generator is reduced to shift to normal idle rotation speed control, and fuel cut is continued for a long time without stopping the engine.
JP-A-6-26372

Furthermore, the hybrid vehicle control device detects that the reduction ratio of the automatic transmission becomes the startable reduction ratio when the fuel cut is performed at the time of deceleration, and permits the engine to stop based on this detection result. By doing this, there is one that prevents the engine from stopping before the reduction ratio of the automatic transmission reaches the startable reduction ratio.
JP 2001-39184 A

  By the way, in the control device described in Patent Document 1, once the predetermined vehicle speed is exceeded, the shift position is in the non-traveling range (P or N range), or the brake pedal is depressed in the traveling range (D range). In this case, the fuel supply restart following the fuel cut is prohibited, so the following problems occur when applying to a hybrid vehicle equipped with a stepped automatic transmission having a torque converter. To do.

  A control device for a hybrid vehicle including a stepped automatic transmission having a torque converter is configured to engage or slip-engage a lockup mechanism that directly connects the torque converter even during deceleration in order to continue fuel cut for a long time. Is controlling.

  However, in the hybrid vehicle control device, when the vehicle speed decreases, the engine rotation speed also decreases. Therefore, in order to continue the fuel cut, it is necessary to perform control so that the engine rotation speed is kept high by performing a downshift. However, in this hybrid vehicle control device, since the downshift with the lockup mechanism engaged involves a shift shock, lockup at the time of deceleration is performed only in the high speed range (for example, 3rd speed or 4th speed), Control is performed so that lockup is not performed at a low speed (for example, second gear or first gear).

  Therefore, in the vehicle speed range (for example, 35 km / h or less) lower than the speed at which the lockup can be performed in the high speed range, the engine is stopped when the resumption of fuel supply is prohibited. Therefore, this hybrid vehicle control device has a problem that the frequency of stopping the engine increases in a vehicle speed range lower than the speed at which the lockup is possible, which is troublesome for the driver.

  On the other hand, there is one described in Patent Document 2 as a fuel cut that continues for a long time without stopping the engine.

  However, the hybrid vehicle control device described in Patent Document 2 is for the purpose of preventing engine stall due to the expansion of the fuel cut region, and finally starts the fuel supply to perform idle operation. In the state, it cannot be applied to a hybrid vehicle that stops the engine. Therefore, the hybrid vehicle control device described in Patent Document 2 solves the above problems when applied to a hybrid vehicle including a stepped automatic transmission with a torque converter described in Patent Document 1. There are inconveniences that cannot be made.

  The present invention provides a control device for a hybrid vehicle comprising an engine, a motor generator capable of driving and assisting the engine, and an automatic transmission with a torque converter, wherein the brake pedal is depressed when the hybrid vehicle is decelerated. When the fuel cut is being performed, when the deceleration of the hybrid vehicle is larger than a set value, a control means for assisting the engine with the motor generator is provided.

  In the control apparatus for a hybrid vehicle according to the present invention, when fuel cut is performed with the brake pedal depressed during deceleration, if the deceleration is larger than a set value, the motor generator generates electric power even if the engine is likely to stall. By performing the assist control by the machine, the engine rotation speed can be maintained near the idle rotation speed, so the fuel cut time can be made longer, and the fuel consumption is reduced while the number of engine stops is reduced. Can be made.

In the control apparatus for a hybrid vehicle according to the present invention, when fuel cut is performed with the brake pedal depressed during deceleration, if the deceleration is larger than a set value, the motor generator generates electric power even if the engine is likely to stall. By performing the assist control by the machine, the fuel consumption can be reduced while further extending the fuel cut time and reducing the number of engine stops.
Embodiments of the present invention will be described below with reference to the drawings.

  1 to 9 show an embodiment of the present invention. In FIG. 9, 2 is a hybrid vehicle, 4 is an engine, 6 is a motor generator, and 8 is an automatic transmission. The hybrid vehicle 2 includes an engine 4, a motor generator 6 connected to a crankshaft (not shown) of the engine 4, and a stepped automatic transmission 8 connected to the motor generator 6. . The hybrid vehicle 2 travels by transmitting the driving force generated by the engine 4 and / or the motor generator 6 from the automatic transmission 8 to the wheel 14 via the differential 10 through the axle 12.

  The engine 4 has a fuel injection valve 16. A battery 20 is connected to the motor generator 6 connected to the engine 4 via an inverter 18. The motor generator 6 is driven by the electric power of the battery 20 to generate torque, and has a motor function capable of driving and assisting the engine 4, and is driven by driving force from the engine 4 side or the wheel 14 side to generate regenerative power. The battery 20 has a power generation function for charging the battery 20 via the inverter 18.

  The automatic transmission 8 includes a fluid type torque converter 22 and a gear type transmission unit 24. The torque converter 22 includes a pump impeller (not shown), a turbine runner, and a stator, and increases torque from the pump impeller on the input side to the turbine runner on the output side by the stator to transmit the torque.

  As shown in FIG. 7, the torque converter 22 engages / releases the pump impeller and the turbine runner in the lock-up region, the slip region, and the other unlock-up regions set by the throttle opening and the vehicle speed. A clutch-type lockup mechanism 26 is provided. The lockup mechanism 26 engages the pump impeller and the turbine runner by a lockup operation to prevent relative rotation, partially restricts the relative rotation between the pump impeller and the turbine runner by a slip operation, and performs an unlockup operation. Allow relative rotation between the pump impeller and the turbine runner. The transmission unit 24 includes a planetary gear (not shown) and the like, and includes a friction engagement element 28 including a clutch, a brake, and the like that switch a power transmission path. The friction engagement element 28 switches the gear position of the gear type transmission unit 24.

  The motor generator 6 and the fuel injection valve 16 are provided so as to be connected to the control means 32 constituting the control device 30 of the hybrid vehicle 2. The control means 32 includes a vehicle speed sensor 34 that detects the vehicle speed, an engine rotation sensor 36 that detects the engine rotation speed, a turbine rotation sensor 38 that detects the turbine rotation speed of the turbine runner of the torque converter 22, and a throttle of the engine 4. A throttle sensor 40 for detecting a throttle opening of a valve (not shown), a brake switch 42 for detecting a depression / release state of a brake pedal (not shown) of the hybrid vehicle 2, and a shift lever device of the automatic transmission 8 A shift position switch 44 for detecting the shift lever position (not shown) is connected.

  Further, the control means 32 includes a lock-up solenoid 46 that operates the lock-up mechanism 26 provided in the torque converter 22, a shift solenoid 48 that operates the friction engagement element 28 provided in the transmission unit 24, and an idle operation. An idle speed control valve 50 for controlling the amount of bypass air at the time is connected and provided.

  The control means 32 includes a regenerative power generation control unit 52 that controls the amount of regenerative power generated by the motor generator 6 and a lockup control that locks up the lockup mechanism 26 in a set operation region (see FIG. 7). Part 54 and a slip control part 56 for controlling the lockup mechanism 26 to slip in the set operation region (see FIG. 7).

  The control means 32 inputs various signals from the vehicle speed sensor 34 to the shift position switch 44, supplies power from the battery 20 to the motor generator 6 via the inverter 18, and controls the engine 4 to drive and assist. The motor generator 6 is driven by the driving force from the engine 4 side or the wheel 14 side to generate regenerative power, and the battery 20 is charged via the inverter 18.

  Further, the control means 32 inputs various signals from the vehicle speed sensor 34 to the shift position switch 44, and when the automatic stop condition is satisfied during the operation of the engine 4, the fuel supply by the fuel injection valve 16 is stopped and the engine 4 is stopped. When the engine 4 is controlled to be automatically stopped and the automatic start condition is satisfied while the engine 4 is automatically stopped, the fuel is supplied by the fuel injection valve 16 while the engine 4 is driven by the motor generator 6 (or a starter motor (not shown)). The engine 4 is controlled so as to start automatically, and the engine 4 can be automatically stopped or started without operating an ignition key (not shown).

  Further, the control means 32 inputs various signals from the vehicle speed sensor 34 to the shift position switch 44, and when the hybrid vehicle 2 decelerates, the fuel supply by the fuel injection valve 16 is stopped and the motor generator 6 is regenerated while the fuel is cut. When the engine rotational speed falls below a set rotational speed set on the high side near the idle rotational speed, the fuel supply is controlled to resume.

  As shown in FIG. 8, the control device 30 of the hybrid vehicle 2 includes a control unit 32 that includes a turbine rotation correction torque calculation unit 58 that calculates a turbine rotation correction torque from the turbine rotation speed detected by the turbine rotation sensor 38, and an engine rotation. A rotation feedback correction torque calculator 60 that calculates a rotation feedback correction torque from the engine rotation speed detected by the sensor 36, and a deceleration (vehicle speed decrease per unit time) of the hybrid vehicle 2 from the vehicle speed detected by the vehicle speed sensor 34. The fuel is calculated based on the deceleration calculation unit 62, the throttle opening detected by the throttle sensor 40, the depression state of the brake pedal by the brake switch 42, the vehicle speed detected by the vehicle speed sensor 34, and the deceleration output by the deceleration calculation unit 62. Fuel cut joint for determining whether to perform continuous cut assist control Fuel cut continuation assist torque is calculated from the output of the assist control execution determination unit 64, the output of the turbine rotation correction torque calculation unit 58, the output of the rotation feedback correction torque calculation unit 60, and the output of the fuel cut continuation assist control execution determination unit 64. And a fuel cut continuation assist torque calculating unit 66 that outputs a torque command value to the inverter 18.

  Thereby, the control device 30 of the hybrid vehicle 2 sets the deceleration of the hybrid vehicle 2 when the control means 32 performs the fuel cut of the engine 4 while the brake pedal is depressed when the hybrid vehicle 2 is decelerated. When the value is larger than the value, the engine 4 is assisted and controlled by the motor generator 6.

  The control means 32 ends the assist control of the engine 4 by the motor generator 6 when the vehicle speed decreases to the set vehicle speed, and the assist control amount by the motor generator 6 increases as the vehicle speed or the turbine rotational speed of the torque converter 22 decreases. To control.

  The automatic transmission 6 includes a lockup mechanism 26 in the torque converter 22, and the control means 32 includes a regenerative power generation control unit 52 that controls a regenerative power generation amount regenerated by the motor generator 6, and a set operation region. 2 includes a lock-up control unit 54 that locks up the lock-up mechanism 26 and a slip control unit 56 that performs slip control of the lock-up mechanism 26 in a set operation region. The slip control unit 56 includes a motor generator. The slip control of the lockup mechanism 26 is performed in a region where the engine speed is higher than the assist control region according to 6.

  That is, in the control device 30 of the hybrid vehicle 2 including the engine 4, the motor generator 6 capable of driving and assisting the engine 4, and the automatic transmission 8 with the torque converter 22, the engine is cut in a state where fuel cut is continued during deceleration. When the brake pedal is depressed in a vehicle state where the vehicle 4 stops, the engine speed is maintained in the vicinity of the idle speed while continuing the fuel cut by assisting the motor generator 6 to the drive side. When the vehicle speed drops to a set vehicle speed (for example, 15 km / h), the assist control of the motor generator 6 is terminated while the fuel cut is continued, and the engine 4 is stopped. Yes.

  Further, when the motor generator 6 is assisted and controlled so as to maintain the engine rotation speed near the idle rotation speed, the motor torque is feedback-controlled using the vicinity of the idle rotation speed as the target rotation speed, and the vehicle speed or the torque converter 22 In accordance with the turbine rotation speed, the assist control amount of the motor generator 6 is corrected so that the motor torque increases as the vehicle speed or the turbine rotation speed of the lux converter 22 decreases. Furthermore, when the deceleration is small, the motor generator 6 is configured not to perform control to continue the fuel cut by assist control.

  Next, the operation of the embodiment will be described.

  The control device 30 of the hybrid vehicle 2 is applied to an automatic transmission 8 with a torque converter 22 provided with a lockup mechanism 26. In the case of the automatic transmission 8 with the torque converter 22 provided with the lock-up mechanism 26, the shock at the time of acceleration shift can be reduced if the lock-up mechanism 26 is released during deceleration, but the fuel cut is reduced. In order to increase the amount of regenerative power generation by extending the time, lock-up control (including slip lock-up) is performed even during deceleration as shown in the lock-up diagram shown in FIG.

  As shown in FIG. 2, when the program starts (102), the control device 30 of the hybrid vehicle 2 takes in various signals from various sensors such as the vehicle speed sensor 34 and a switch group (104), and the throttle opening is a fuel cut determination threshold value. It is judged whether it is less than (106).

  If this determination (106) is YES, it is determined whether or not the engine speed exceeds the fuel cut determination threshold (108).

  If this determination (108) is YES, the fuel cut at the time of deceleration is performed (110), and the deceleration basic regenerative torque at the time of fuel cut is calculated from the data at the time of fuel cut in the basic regenerative torque calculation table at the time of deceleration shown in FIG. (112) Then, the regenerative torque generated by the motor generator 6 is used as the deceleration basic regenerative torque at the time of fuel cut (114), regenerative power is generated, and the process returns (116).

  On the other hand, if the determination (106) and determination (108) are NO, the fuel supply is performed (118), and the fuel supply data is determined from the data at the time of fuel supply in the deceleration basic regenerative torque calculation table shown in FIG. The basic regenerative torque is calculated (120), and it is determined whether or not the fuel cut return transition time is reached (122).

  When this determination (122) is YES, the regenerative torque by the motor generator 6 is gradually increased to the basic regenerative torque at the time of fuel supply (124), regenerative power generation is performed, and the process returns (116). If this determination (122) is NO, the regenerative torque generated by the motor generator 6 is used as the basic regenerative torque at the time of fuel supply (126), and the power is returned (116).

  The deceleration-time basic regenerative torque calculation table shown in FIG. 6 is set based on the engine rotation speed, and is set so that the regenerative torque decreases as the rotation decreases on the low engine rotation speed side. The regenerative torque is set to change depending on the presence or absence.

  Thus, the control device 30 of the hybrid vehicle 2 controls the regenerative torque of the motor generator 6 at the time of fuel cut and fuel supply.

  The control device 30 of the hybrid vehicle 2 assists the engine 4 with the motor generator 6 when the deceleration is larger than the set value in order to continue the fuel cut during deceleration.

  As shown in FIG. 1, when the program starts (202), the control device 30 of the hybrid vehicle 2 takes in various signals (204) from various sensors such as the vehicle speed sensor 34 and a switch group, and opens the throttle detected by the throttle sensor 40. It is determined whether the degree is fully closed, the brake pedal 42 is depressed by turning on the brake switch 42, and the deceleration of the hybrid vehicle 2 calculated from the vehicle speed exceeds the set value dVs (206).

  When this determination (206) is YES, it is a case where the fuel pedal of the engine 4 is being cut with the brake pedal depressed when the hybrid vehicle 2 is decelerated, and it is determined whether or not the vehicle speed exceeds the set vehicle speed Vsl. (208).

  When the determination (208) is YES, the rotation feedback correction torque calculation unit 60 calculates the rotation feedback correction torque (Tfb) according to the engine rotation speed from the rotation feedback correction torque calculation table shown in FIG. 4 (210), The turbine rotation correction torque calculation unit 58 calculates the turbine rotation correction torque (Tnt) from the turbine rotation correction torque calculation table shown in FIG. 5 according to the turbine rotation speed (212), and from the rotation feedback correction torque and the turbine rotation correction torque, The motor torque is calculated (Tfb + Tnt) (214), the motor generator 6 is driven by this motor torque to perform fuel cut while assisting the engine 4 (216), and the process returns (218).

  The rotation feedback correction torque calculation table shown in FIG. 4 sets the rotation feedback correction torque so that the assist torque decreases as the engine speed increases. The turbine rotation correction torque calculation table shown in FIG. 5 sets the turbine rotation correction torque so that the assist torque decreases as the turbine rotation speed increases.

  On the other hand, if the determination (206) is NO, the hybrid vehicle 2 is not decelerating and returns (218). If the determination (208) is NO, the vehicle speed has decreased to the set vehicle speed Vsl. Therefore, the motor torque is set to “0” (220), the assist control by the motor generator 6 is terminated, and the fuel is discharged. Cut is performed (216), and the process returns (218).

  As described above, the control device 30 of the hybrid vehicle 2 locks up the lockup mechanism 26 as the vehicle speed decreases from the state in which regenerative power generation is performed at the time of deceleration with the accelerator pedal in the return state and the brake pedal depressed. The motor torque of the motor generator 6 is controlled until the vehicle speed is lowered and the engine is stopped.

  As shown in FIG. 3, the control device 30 of the hybrid vehicle 2 controls the engine speed by slip-controlling the lockup mechanism 26 until time t1 when the fuel is being cut while the brake pedal is depressed during deceleration. Is kept high, and regenerative control is performed during fuel cut and deceleration. In the regenerative control, torque based on the flowchart shown in FIG. 2 and the table data shown in FIG. 6 is controlled as regenerative torque.

  At time t1, since the vehicle moves out of the lockup region as the vehicle speed decreases, the lockup control of the lockup mechanism 26 is released. FIG. 7 shows an example of the lockup control area. As a result of releasing the lock-up control, the engine speed decreases. However, the fuel-cut continuation assist control assists the motor generator 6 so that the engine speed becomes a set speed near the idle speed. The engine rotation speed can be maintained in the vicinity of the idle rotation speed while the operation is continued. The motor torque of the assist control at this time is calculated as the sum of the rotation feedback correction torque (see FIG. 4) based on the engine rotation speed and the turbine rotation correction torque (see FIG. 5) based on the turbine rotation speed.

  The control device 30 of the hybrid vehicle 2 performs correction by the turbine rotation correction torque based on the turbine rotation speed, whereby the pump torque of the torque converter 22 determined by the characteristics of the torque converter 22, the turbine rotation speed and the engine rotation speed, that is, the engine 4 Since the amount of torque output from the output shaft can be determined without feedback control, even if the turbine rotational speed changes due to the deceleration of the hybrid vehicle 2, the motor required to maintain the engine rotational speed at the idle rotational speed Torque can be calculated appropriately and fluctuations in engine speed can be suppressed.

  The control device 30 of the hybrid vehicle 2 ends the assist control of the engine 4 by the motor generator 6 in a state where the fuel cut is continued to stop the engine at time t2 when the vehicle speed is reduced to the set vehicle speed.

  As described above, the control device 30 of the hybrid vehicle 2 includes the engine 4, the motor generator 6 that can drive and assist the engine 4, and the automatic transmission 8 with the torque converter 22. When the brake pedal is depressed in a vehicle state where the engine 4 stops while the fuel cut is continued, the motor speed is controlled while the fuel cut is continued by controlling the motor generator 6 to drive. Control is performed so that the engine speed is maintained at a set rotational speed in the vicinity (between times t1 and t2), and when the vehicle speed decreases to the set vehicle speed, the assist control of the motor generator 6 is performed while the fuel cut is continued. At the end (time t2), the engine 4 is stopped.

  Thus, when the brake pedal is depressed to decelerate, the fuel cut can be continued, and the engine 4 is stopped after the vehicle speed has decreased, so the frequency at which the engine is stopped in a region where the vehicle speed is relatively high. This reduces the troublesomeness to the driver, and assist control by the motor generator 6 is performed even when the engine 4 is likely to stall in a state where fuel cut is performed at the time of deceleration. As a result, the engine rotation speed can be maintained in the vicinity of the idle rotation speed, so that the fuel cut time can be made longer, and the fuel consumption can be reduced while reducing the number of engine stops.

  In addition, the control device 30 of the hybrid vehicle 2 assists the motor generator 6 with the target rotational speed when the motor generator 6 is assisted and controlled so as to maintain the engine rotational speed at the set rotational speed near the idle rotational speed. In addition to feedback control of the assist control motor torque as the speed, correction control is performed so that the motor torque of the assist control increases as the vehicle speed or the turbine rotation speed of the torque converter 22 decreases according to the vehicle speed or the turbine rotation speed of the torque converter 22. Is going.

  Thereby, the control device 30 of the hybrid vehicle 2 feedback-controls the pump torque of the torque converter 22 determined by the characteristics of the torque converter 22, the turbine rotation speed and the engine rotation speed, that is, the torque output from the output shaft of the engine 4. Therefore, even if the turbine rotational speed changes due to the deceleration of the hybrid vehicle 2, the motor torque necessary to maintain the engine rotational speed at the idle rotational speed can be appropriately calculated, and fluctuations in the engine rotational speed can be calculated. Can be suppressed.

  Furthermore, the control device 30 of the hybrid vehicle 2 is configured not to perform control to continue the fuel cut by assisting control of the motor generator 6 when the deceleration is small. When the vehicle is traveling at a constant vehicle speed, the assist control by the motor generator 6 can be prevented from being performed, and excessive power consumption can be prevented.

  Further, the control device 30 of the hybrid vehicle 2 ends the assist control of the engine 4 by the motor generator 6 for continuing the fuel cut when the vehicle speed decreases to the set vehicle speed, so that the hybrid vehicle 2 is surely stopped. The assist control can be performed until the vehicle speed decreases to a stable state, and the fuel cut state of the engine 4 can be continued for a long time.

  Furthermore, the control device 30 of the hybrid vehicle 2 performs control so that the assist control amount by the motor generator 6 increases as the vehicle speed or the turbine rotation speed of the torque converter 22 decreases, so that the engine rotation speed during deceleration is reduced. It is possible to lengthen the time until the vehicle stops, and to increase the fuel cut time. Even if the turbine rotational speed changes due to the deceleration of the hybrid vehicle 2, the engine rotational speed is idle. Since the assist amount necessary for maintaining the rotational speed can be calculated appropriately, fluctuations in the engine rotational speed can be suppressed.

  Furthermore, in the control device 30 of the hybrid vehicle 2, the automatic transmission 8 includes the lockup mechanism 22 in the torque converter 22, and the control means 32 controls the regenerative power generation control that controls the amount of regenerative power generated by the motor generator 6. Section 52, a lockup control unit 54 that locks up the lockup mechanism 26 in the set operation region, and a slip control unit 56 that performs slip control of the lockup mechanism 26 in the set operation region. The control unit 56 performs the slip control of the lockup mechanism 26 by performing the slip control of the lockup mechanism 26 in the region where the engine speed is higher than the assist control region by the motor generator 6 for continuing the fuel cut. Implement sufficient regenerative power generation control, engine speed Because There further can be carried assist control after reduction, it is possible to achieve both the different two control, it is possible to reduce fuel consumption.

  The present invention is not limited to the above-described embodiments, and various application modifications can be made.

  For example, in the above-described embodiment, the assist torque is corrected based on the turbine rotation speed. However, if the speed is the same, the turbine rotation speed is proportional to the vehicle speed. Therefore, the assist torque is corrected based on the vehicle speed. May be.

  Moreover, the energy consumption by the motor generator 6 can be suppressed by changing the assist torque by the motor generator 6 according to the deceleration. Further, when the fuel is cut, the engine load by the air conditioner compressor or the like is stopped, or the automatic transmission 8 is shifted to a low speed gear stage to suppress the decrease in engine rotation speed, thereby reducing the assist torque by the motor generator 6. The energy consumption by the motor generator 6 can be suppressed.

  In the control apparatus for a hybrid vehicle according to the present invention, when fuel cut is performed with the brake pedal depressed during deceleration, if the deceleration is larger than a set value, the motor generator generates electric power even if the engine is likely to stall. By performing the assist control by the machine, the fuel consumption can be reduced while extending the fuel cut time and reducing the number of engine stops.

It is a flowchart of the fuel cut continuation of the control apparatus of the hybrid vehicle which shows an Example. It is a flowchart of the fuel cut of the control apparatus of a hybrid vehicle. It is a timing chart of the fuel cut continuation of the control apparatus of a hybrid vehicle. It is a figure which shows the rotation feedback correction torque calculation table based on an engine speed. It is a figure which shows the turbine rotation correction torque calculation table based on a turbine rotational speed. It is a figure which shows the basic regeneration torque calculation table at the time of deceleration based on an engine speed. It is a figure which shows the lockup area | region by throttle opening and a vehicle speed. It is a system block diagram of the control apparatus of a hybrid vehicle. It is a control block diagram of the control apparatus of a hybrid vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Hybrid vehicle 4 Engine 6 Motor generator 8 Automatic transmission 16 Fuel injection valve 18 Inverter 20 Battery 22 Torque converter 24 Shift part 26 Lockup mechanism 30 Control apparatus 32 Control means 34 Vehicle speed sensor 36 Engine rotation sensor 38 Turbine rotation sensor 40 Throttle Sensor 42 Brake switch 44 Shift position switch 46 Lockup solenoid 48 Shift solenoid 50 Idle speed control valve 52 Regenerative power generation control unit 54 Lockup control unit 56 Slip control unit 58 Turbine rotation correction torque calculation unit 60 Rotation feedback correction torque calculation unit 62 Decrease Speed calculation unit 64 Fuel cut continuation assist control execution determination unit 66 Fuel cut continuation assist torque calculation unit

Claims (4)

  In a hybrid vehicle control device comprising an engine, a motor generator capable of driving and assisting the engine, and an automatic transmission with a torque converter, the fuel cut of the engine is performed with the brake pedal depressed when the hybrid vehicle is decelerated. When the deceleration of the hybrid vehicle is greater than a set value, a control device for controlling the engine with the motor generator is provided.   2. The hybrid vehicle control device according to claim 1, wherein the control means ends the assist control of the engine by the motor generator when the vehicle speed decreases to a set vehicle speed. 3.   3. The hybrid vehicle according to claim 1, wherein the control unit performs control such that the assist control amount by the motor generator increases as the vehicle speed or the turbine rotation speed of the torque converter decreases. 4. Control device.   The automatic transmission includes a lockup mechanism in a torque converter, the control means includes a regenerative power generation control unit that controls a regenerative power generation amount regenerated by the motor generator, and the lockup mechanism in a set operation region. A lockup control unit for performing a lockup operation, and a slip control unit for performing slip control of the lockup mechanism in a set operation range, wherein the slip control unit has a higher engine rotation speed than the assist control region by the motor generator. The hybrid vehicle control device according to claim 1, wherein slip control of the lockup mechanism is performed in a region.

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