JP2013071467A - Drive control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive control device for vehicle can appropriately conduct electrical charge and discharge of a power storage device while suppressing deterioration of fuel consumption of a hybrid vehicle.SOLUTION: When an electrical charge/discharge necessity determining means 82 determines that electrical charge of the power storage device 57 is required, more specifically, when charging is conducted while maintaining the driving force of a vehicle 8, an electronic control device 58 sets an engine operating point so that the engine operating point when charging falls within an LTc standard range. Also in the case the electrical charge/discharge necessity determining means 82 determines that electrical discharge of the power storage device 57 is required, more specifically, when discharging the vehicle 8 while maintaining the driving force of the vehicle 8, the electronic control device 58 sets the engine operating point so that the engine operating point at the discharging falls within an LTd standard range. Therefore, appropriate electrical charge and discharge of the power storage device 57 can be conducted while suppressing the deterioration of fuel consumption since the electrical charge or discharge of the power storage device 57 can be conducted while suppressing the deterioration of engine heat efficiency to a certain extent.

Description

  The present invention relates to travel control when charging or discharging a power storage device in a hybrid vehicle.

  A hybrid vehicle including a stepped automatic transmission has been conventionally known. For example, Patent Document 1 discloses a vehicle drive control device that controls the hybrid vehicle. When the vehicle drive control device of Patent Document 1 determines that there is a need for shifting of the automatic transmission (stepped transmission), it calculates the amount of increase / decrease in the charge amount prior to the shifting, The engine operating point is changed based on the amount of increase / decrease in the charge amount.

Japanese Patent Laid-Open No. 2005-096574 JP 2010-275955 A JP 2006-090154 A JP-A-6-048222

  When the automatic transmission is shifted, the input rotational speed of the automatic transmission changes before and after the shift. In the vehicle drive control device of Patent Document 1, it is possible to control the engine operating point not to be constrained by the input rotational speed of the automatic transmission by controlling the power distribution device. However, in a hybrid vehicle that does not include the power distribution device. The engine operating point is restricted by the input rotational speed of the automatic transmission. In that case, it is assumed that the engine operating point is changed by the shift of the automatic transmission so that the fuel consumption is deteriorated as compared with that before the shift. For example, when the engine operating point is changed in order to increase or decrease the charge amount of the power storage device of the hybrid vehicle, the shift of the automatic transmission is changed rather than the engine operating point being changed with the shift of the automatic transmission. It was assumed that the fuel efficiency could be better if the engine operating point was changed while maintaining the current stage. Such a problem is not yet known.

  The present invention has been made in the background of the above circumstances, and the object of the present invention is to drive a vehicle capable of appropriately charging and discharging a power storage device while suppressing deterioration of fuel consumption of the vehicle in a hybrid vehicle. It is to provide a control device.

  The subject matter of the first invention for achieving the above object is: (a) a stepped automatic transmission that constitutes a part of a power transmission path from the engine to the drive wheels; When charging the power storage device, the vehicle is provided with an electric motor and a power storage device electrically connected to the motor, while regenerating part of the engine power to the motor, A vehicle drive control device that consumes power by driving the electric motor when discharging, and (b) when charging or discharging the power storage device while maintaining the driving force of the vehicle, The engine operating point is determined so that the engine operating point falls within a predetermined target engine operating range based on a maximum thermal efficiency line of the engine.

  In this way, the power storage device can be charged or discharged while suppressing the deterioration of the thermal efficiency of the engine to some extent, so that the power storage device can be appropriately charged / discharged while suppressing the deterioration of the fuel consumption of the vehicle. The fuel efficiency is, for example, a travel distance per unit fuel consumption, and the improvement in fuel efficiency is an increase in the travel distance per unit fuel consumption, or a fuel consumption rate (= fuel consumption). / Drive wheel output) is reduced. Conversely, the reduction (deterioration) in fuel consumption means that the travel distance per unit fuel consumption is shortened or the fuel consumption rate is increased.

  The gist of the second invention is the vehicle drive control device according to the first invention, in which the power storage device is charged or discharged while maintaining the driving force of the vehicle. When the operating point of the engine determined from the charging power or the discharging power is out of the target engine operating range at the current shift stage of the automatic transmission, the operating point of the engine is changed by shifting the automatic transmission. Is within the target engine operating range, while the engine operating point is within the target engine operating range at the current shift speed of the automatic transmission, the current shift speed of the automatic transmission is It is characterized by holding. In this way, the automatic transmission is not shifted so as to deteriorate the thermal efficiency of the engine as the power storage device is charged or discharged. This can avoid the situation where fuel consumption deteriorates. That is, it is possible to appropriately charge and discharge the power storage device while suppressing deterioration in fuel consumption.

  The gist of the third invention is the vehicle drive control device of the second invention, wherein (a) a shift diagram for performing a shift of the automatic transmission is predetermined, b) Required for the vehicle when the engine operating point determined from the running power and the charging power or discharging power is out of the target engine operating range at the current gear position of the automatic transmission. Whether or not to shift the automatic transmission from the shift diagram based on a total load amount obtained by adding a load amount corresponding to the charging power or discharging power as a positive direction to the vehicle required load amount. It is characterized by judging. In this way, whether or not the power storage device is charged or discharged, the automatic transmission can be shifted using the common shift diagram, and the control load can be reduced. It is.

  The gist of the fourth invention is the vehicle drive control device of the third invention, wherein (a) the shift diagram is composed of two-dimensional coordinates of a vehicle speed and an accelerator opening. (B) The vehicle required load amount is represented by an actual accelerator opening, and (c) the load amount corresponding to the charging power or discharging power is a virtual accelerator opening corresponding to the charging power or discharging power. It is expressed in degrees. In this way, it is possible to determine whether or not to shift the automatic transmission based on the vehicle speed and the accelerator opening, and both the vehicle speed and the accelerator opening are easily detected by a sensor or the like. It is possible to easily determine whether or not to perform the shift.

  The gist of a fifth invention is the vehicle drive control device according to any one of the second invention to the fourth invention, wherein (a) the battery control device is executed when the power storage device is charged. The shift of the automatic transmission is a down shift, and the shift of the automatic transmission executed when discharging the power storage device is an up shift. In this way, when the power storage device is charged, the operating state of the engine can be changed in a direction suitable for charging the power storage device by downshifting the automatic transmission. Further, when discharging the power storage device, the operating state of the engine can be changed in a direction suitable for discharging the power storage device by upshifting the automatic transmission.

  Here, preferably, (a) the target engine operating range is predetermined for each of a case where the power storage device is charged and a case where the power storage device is discharged, and (b) the The target engine operating range when charging the power storage device is compared with the operating point of the engine after the downshift when assuming that the automatic transmission is downshifted while maintaining the engine power. The engine operating point before the downshift where the thermal efficiency of the engine is equal to or higher is present, and (c) the target engine operating range in the case of discharging the power storage device, while maintaining engine power Compared to the operating point of the engine after the upshift when it is assumed that the automatic transmission has been upshifted, the above-mentioned up change where the thermal efficiency of the engine is equal to or higher than that. It is a range in which the operating point of the front of the engine is present. It should be noted that the fact that the engine power is maintained in the downshift or the upshift of the automatic transmission is such that the engine power is the same before and after the shift, or the engine power is the same before and after the shift. The engine power fluctuates within the range.

  Preferably, the case where the power storage device is charged or discharged is a case where the power storage device is forcibly charged or discharged due to a preset charge / discharge restriction.

It is a figure which shows notionally the structure of the drive system which concerns on the hybrid vehicle which is one Example of this invention. FIG. 2 is a diagram for explaining a relationship between engine thermal efficiency and downshift of an automatic transmission in the hybrid vehicle of FIG. 1. FIG. 2 is a diagram for explaining a relationship between engine thermal efficiency and an upshift of an automatic transmission in the hybrid vehicle of FIG. 1. It is a functional block diagram for demonstrating the principal part of the control function with which the electronic control apparatus of FIG. 1 was equipped. FIG. 2 is a diagram showing an example in which an assumed engine operating point at the time of charging is within an LTc reference range at the current shift stage of the automatic transmission included in the hybrid vehicle of FIG. 1. FIG. 2 is a diagram showing an example in which an assumed engine operating point at the time of charging is out of an LTc reference range at the current gear position of the automatic transmission included in the hybrid vehicle of FIG. 1. FIG. 2 is a diagram illustrating an example in which an assumed engine operating point during discharge is within an LTd reference range at the current shift stage of the automatic transmission included in the hybrid vehicle of FIG. 1. FIG. 2 is a diagram showing an example in which an assumed engine operating point at the time of discharge is out of an LTd reference range at the current gear position of the automatic transmission included in the hybrid vehicle of FIG. 1. FIG. 2 is a diagram extracted from a shift diagram for a down shift line for determining that the automatic transmission included in the hybrid vehicle of FIG. FIG. 2 is an excerpt from an upshift line for determining that the automatic transmission of the hybrid vehicle of FIG. 1 has an upshift from the current shift stage to the first stage high speed side. The main part of the control operation of the electronic control device of FIG. 1, that is, the control operation for judging the shift of the automatic transmission so as not to decrease the engine thermal efficiency when charging and discharging the power storage device while maintaining the driving force of the hybrid vehicle. It is a flowchart for demonstrating.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram conceptually showing the structure of a drive system relating to a hybrid vehicle 8 (hereinafter also simply referred to as “vehicle 8”) according to an embodiment of the present invention. A hybrid vehicle 8 shown in FIG. 1 includes a vehicle drive device 10 (hereinafter referred to as “drive device 10”), a differential gear device 21, a pair of left and right axles 22, a pair of left and right drive wheels 24, and a hydraulic control circuit. 34, an inverter 56, and an electronic control unit 58. The drive device 10 functions as a driving power source for driving and is an engine 12 such as a known gasoline engine or diesel engine, and engine output control for performing engine output control such as starting or stopping of the engine 12 or throttle control. The apparatus 14 includes an electric motor MG that is an electric motor for driving that functions as a driving power source for driving, an engine intermittent clutch K0, a torque converter 16, and an automatic transmission 18. As shown in FIG. 1, the vehicle 8 has a power generated by one or both of the engine 12 and the electric motor MG, the torque converter 16, the automatic transmission 18, the differential gear device 21, and a pair of left and right axles. 22 is configured to be transmitted to a pair of left and right drive wheels 24 via each. Therefore, the vehicle 8 can selectively travel between the engine travel that travels with the power of the engine 12 and the EV travel (motor travel) that stops the engine 12 and travels exclusively with the power of the electric motor MG. it can. In the engine running, the electric motor MG may generate assist torque depending on the running state.

  The electric motor MG is connected to a power transmission path from the engine 12 or the torque converter 16 to the drive wheels 24. Specifically, the rotor 30 of the electric motor MG is connected to a pump impeller 16p, which is an input member of the torque converter 16, so as not to be relatively rotatable. The electric motor MG is, for example, a three-phase synchronous motor, and is a motor generator having a function as a motor (motor) that generates power and a function as a generator (generator) that generates reaction force. For example, the electric motor MG generates a vehicle braking force by regenerative operation. Further, the electric motor MG is electrically connected to the power storage device 57 via the inverter 56, and the electric motor MG and the power storage device 57 are configured to be able to exchange power with each other. The power storage device 57 is, for example, a battery (secondary battery) such as a lead storage battery or a capacitor.

  The power transmission path between the engine 12 and the electric motor MG is provided with an engine intermittent clutch K0 which is a generally known wet multi-plate hydraulic friction engagement device. The engine interrupting clutch K0 functions as a power interrupting device that operates with the hydraulic pressure supplied from the hydraulic control circuit 34 and selectively interrupts power transmission between the engine 12 and the drive wheels 24. Specifically, an engine output shaft 26 (for example, a crankshaft), which is an output member of the engine 12, is connected to the rotor 30 of the electric motor MG so as not to rotate relative to the engine 30 by engaging the engine intermittent clutch K0. The clutch K0 is disengaged from the rotor 30 of the electric motor MG. In short, the engine output shaft 26 is selectively connected to the rotor 30 of the electric motor MG via the engine intermittent clutch K0. Therefore, the engine intermittent clutch K0 is engaged during the engine travel and is released during the motor travel.

  The automatic transmission 18 constitutes a part of a power transmission path from the engine 12 or the torque converter 16 to the drive wheels 24, and transmits the power of the engine 12 or the electric motor MG to the drive wheels 24. The automatic transmission 18 is a stepped automatic transmission that shifts according to a preset relationship (shift diagram). In other words, the automatic transmission 18 is an automatic transmission mechanism in which any one of a plurality of predetermined shift speeds (speed ratios) is alternatively established, and in order to perform such a shift, A planetary gear unit and a plurality of clutches or brakes operated by hydraulic pressure from the hydraulic control circuit 34 are provided.

  The torque converter 16 is a fluid transmission device interposed between the electric motor MG and the automatic transmission 18. The torque converter 16 includes a pump impeller 16p that is an input side rotating element, a turbine impeller 16t that is an output side rotating element, and a stator impeller 16s. The torque converter 16 transmits the power input to the pump impeller 16p to the turbine impeller 16t via a fluid (hydraulic oil). The stator impeller 16s is connected to a transmission case 36, which is a non-rotating member, via a one-way clutch. The torque converter 16 includes a lock-up clutch LU that selectively connects the pump impeller 16p and the turbine impeller 16t directly to each other between the pump impeller 16p and the turbine impeller 16t. The lockup clutch LU is controlled by the hydraulic pressure from the hydraulic control circuit 34.

  In the vehicle 8, for example, when shifting from the motor travel to the engine travel, the engine speed Ne is increased by the engagement of the engine intermittent clutch K <b> 0 and the engine 12 is started.

  Further, the electronic control unit 58 manages the remaining charge SOC of the power storage device 57 that has been experimentally determined in advance so as not to limit the operation of the electric motor MG as much as possible while maintaining the durability of the power storage device 57. Adjust to fit within the width. That is, the remaining charge management width functions as a charge / discharge limit that is set in advance for power storage device 57. For example, when the electronic control unit 58 charges the power storage device 57 so that the remaining charge SOC of the power storage device 57 is within the charge remaining amount management range during the engine running, A part of Pe is regenerated in the electric motor MG. Conversely, when discharging power storage device 57, electric motor MG is driven to consume power from power storage device 57. Thus, when the power storage device 57 is charged or discharged while the engine is running, the driving power of the vehicle 8 does not change from the case where the charging or discharging is not performed by adjusting the engine power Pe. Maintained.

  The vehicle 8 includes a control system as exemplified in FIG. The electronic control device 58 shown in FIG. 1 includes a function as a vehicle drive control device that controls the drive of the engine 12 and the electric motor MG, and includes a so-called microcomputer. As shown in FIG. 1, the electronic control unit 58 is supplied with various input signals detected by each sensor provided in the hybrid vehicle 8. For example, a signal indicating the accelerator opening degree Acc, which is the depression amount of the accelerator pedal 71 detected by the accelerator opening sensor 60, and a rotation speed (motor rotation speed) Nmg of the motor MG detected by the motor rotation speed sensor 62 are represented. Signal, a signal representing the rotational speed (engine rotational speed) Ne of the engine 12 detected by the engine rotational speed sensor 64, a rotational speed of the turbine impeller 16t of the torque converter 16 detected by the turbine rotational speed sensor 66 (turbine Rotational speed) A signal representing Nt, a signal representing the vehicle speed V detected by the vehicle speed sensor 68, a signal representing the throttle opening θth of the engine 12 detected by the throttle opening sensor 70, and the power storage device obtained from the power storage device 57 A signal indicating the remaining charge (charge state) SOC of 57 and the acceleration sensor 72 A signal representing the vehicle acceleration in the front-rear direction of the vehicle 8 detected by the electronic control unit 58 is input to the electronic control unit 58. Here, the motor rotation speed Nmg detected by the motor rotation speed sensor 62 is the input rotation speed of the torque converter 16, and corresponds to the rotation speed (pump rotation speed) Np of the pump impeller 16p in the torque converter 16. . The turbine rotational speed Nt detected by the turbine rotational speed sensor 66 is the output rotational speed of the torque converter 16, and the rotational speed Natin of the transmission input shaft 19 in the automatic transmission 18, that is, the transmission input rotational speed. Corresponds to Natin. The rotational speed Natout of the output shaft 20 (hereinafter referred to as the transmission output shaft 20) of the automatic transmission 18, that is, the transmission output rotational speed Natout corresponds to the vehicle speed V.

  Various output signals are supplied from the electronic control device 58 to each device provided in the vehicle 8.

  FIG. 2 is a diagram for explaining the relationship between the thermal efficiency of the engine 12 (hereinafter referred to as engine thermal efficiency) and the downshift of the automatic transmission 18. FIG. 2 is composed of two-dimensional coordinates with the engine rotational speed Ne as the horizontal axis and the engine torque Te as the vertical axis. In this embodiment, the engine thermal efficiency is preliminarily determined using the engine rotational speed Ne and the engine torque Te as parameters. It is obtained experimentally and stored in the electronic control unit 58. Further, the engine operating point at which the engine thermal efficiency becomes the highest on the equipower curve, which is a series of engine operating points having the same engine power Pe (unit: kW, for example) as indicated by broken lines L01 and L02 shown in FIG. The maximum thermal efficiency line Litef, which is changed and connected, is stored in advance in the electronic control unit 58. 2 is also stored in advance in the electronic control unit 58. This solid line LTc indicates that the engine thermal efficiency after the equal power down shift is assumed when the equal power down shift in which the automatic transmission 18 is shifted down while the engine power Pe is maintained is performed toward the first-stage low speed side. Is a curve obtained by connecting the engine operating points before the equal power down shift, which is equal to or close to the above value. Therefore, it can be said that the solid line LTc determined from the engine thermal efficiency distribution in the coordinate system of FIG. 2 is determined based on the maximum thermal efficiency line Litef representing the engine thermal efficiency distribution, and the solid line LTc is the maximum thermal efficiency. It is a curve predetermined based on the line Ltef. The solid line LTc is set differently for each gear position of the automatic transmission 18. For example, assuming that the solid line LTc in FIG. 2 is adopted when the automatic transmission 18 is at the third speed, the engine operating point before the equal power down shift, that is, the engine operation at the third speed will be described. If the point is the point PT01b on the solid line LTc and the engine operating point after the equal power down shift, that is, the engine operating point at the second speed is the point PT01a, the engine thermal efficiency indicated by the engine operating point PT01b is The engine thermal efficiency indicated by the engine operating point PT01a is equal to or close to the engine thermal efficiency. For this reason, the range from the solid line LTc to the maximum thermal efficiency line Litef side (hereinafter referred to as the LTc reference range) including the solid line LTc is the same power down shift to the low speed side by the automatic transmission 18. It can be said that the engine operating point before the downshift where the engine thermal efficiency is equal to or higher than that of the engine operating point after the downshift is assumed. The engine thermal efficiency is, for example, the ratio of the amount of heat changed to work of the engine 12 to the total amount of heat obtained from the fuel supplied to the engine 12.

  FIG. 3 is a diagram for explaining the relationship between the engine thermal efficiency and the upshift of the automatic transmission 18. As shown in FIG. 2, FIG. 3 includes two-dimensional coordinates having the engine rotational speed Ne as the horizontal axis and the engine torque Te as the vertical axis. The broken lines L03 and L04 in FIG. 3 are both equal power curves, and the broken line L04 is an equal power curve representing the engine power Pe larger than the broken line L03. Moreover, the maximum thermal efficiency line Ltef shown in FIG. 3 is the same as that of FIG. As described above, the electronic control unit 58 stores the maximum thermal efficiency line Ltef and the solid line LTc (see FIG. 2) in advance, and further stores the solid line LTd shown in FIG. 3 in advance. This solid line LTd indicates that the engine thermal efficiency after the equal power-up shift is assumed when an equal power-up shift in which the automatic transmission 18 is shifted up while the engine power Pe is maintained is executed toward the first stage high speed side. Is a curve obtained by connecting the engine operating points before the above equal power-up shift, which is equal to or close to the above value. Therefore, similarly to the solid line LTc, the solid line LTd can be said to be a predetermined curve based on the maximum thermal efficiency line Litef, and is set differently for each shift stage of the automatic transmission 18. For example, assuming that the solid line LTd in FIG. 3 is adopted when the automatic transmission 18 is at the third speed, the engine operating point before the equal power-up shift, that is, the engine operation at the third speed will be described. If the point is the point PT03b on the solid line LTd and the engine operating point after the equal power-up shift, that is, the engine operating point at the fourth speed is the point PT03a, the engine thermal efficiency indicated by the engine operating point PT03b is The engine thermal efficiency indicated by the engine operating point PT03a is equal to or close to the engine thermal efficiency. For this reason, the range including the solid line LTd and from the solid line LTd to the maximum thermal efficiency line LTef side (hereinafter referred to as the LTd reference range) is the same power-up shift to the first high speed side by the automatic transmission 18. It can be said that the engine operating point before the upshift where the engine thermal efficiency is equal to or higher than that of the engine operating point after the upshift is assumed.

  FIG. 4 is a functional block diagram for explaining the main part of the control function provided in the electronic control unit 58. As shown in FIG. 4, the electronic control unit 58 includes an engine travel determination unit 80 as an engine travel determination unit, a charge / discharge necessity determination unit 82 as a charge / discharge necessity determination unit, and an engine operating point determination unit. Engine operating point determination means 84, stepped shift control means 86 as a stepped shift control section, and drive control means 88 as a drive control section are provided.

  The engine travel determination means 80 determines whether or not the vehicle 8 is traveling on the engine. For example, when the engine 12 is operating and the engine intermittent clutch K0 is engaged and the vehicle 8 is traveling, it is determined that the vehicle 8 is traveling.

  The charging / discharging necessity determining unit 82 determines whether or not the power storage device 57 needs to be charged or discharged when the engine traveling determining unit 80 determines that the vehicle 8 is running the engine. Specifically, it is determined whether or not it is necessary to perform the above charging or discharging in order to keep the remaining charge SOC of the power storage device 57 within the remaining charge management width. For example, the charge / discharge necessity determination unit 82 determines that the power storage device 57 needs to be discharged when the remaining charge SOC is within a predetermined range near the upper limit of the remaining charge management width. On the other hand, when the remaining charge SOC is within a predetermined range near the lower limit of the remaining charge management width, it is determined that the power storage device 57 needs to be charged.

  The engine operating point determination means 84 maintains the current gear position of the automatic transmission 18 and charges it when the charge / discharge necessity determination means 82 determines that the power storage device 57 needs to be charged or discharged. Alternatively, the relationship between the engine operating point when discharging is performed and the solid line LTc (see FIG. 2) or the solid line LTd (see FIG. 3), in other words, the relationship between the engine operating point and the maximum thermal efficiency line Litef is determined. This determination is made before actually starting the charge or discharge. First, the case where it is determined that the power storage device 57 needs to be charged will be described. Specifically, when it is determined that the power storage device 57 needs to be charged, the engine operating point determination means 84 detects the engine rotation speed Ne, maintains the engine rotation speed Ne, and performs the above charging. An engine operating point (hereinafter referred to as an assumed engine operating point at the time of charging) when it has been performed is obtained. That is, at the current gear position of the automatic transmission 18, an assumed engine operating point at the time of charging, which is an engine operating point determined from the traveling power provided for vehicle traveling and the charging power provided for the charging, is obtained. The magnitude of the charging power may be set to a predetermined value in advance, or may be changed according to the remaining charge SOC of power storage device 57. The magnitude of the traveling power can be obtained based on the accelerator opening Acc and the vehicle speed V. Then, the engine operating point determination means 84 determines whether or not the obtained assumed engine operating point at the time of charging is located on the solid line LTc or on the side of the maximum thermal efficiency line Litef from the solid line LTc, that is, the assumed engine at the time of charging. It is determined whether the operating point falls within the LTc reference range. Thus, the engine operating point determination means 84 determines whether the assumed engine operating point at the time of charging falls within the LTc reference range, so that the power storage device 57 can be charged from the viewpoint of improving the engine thermal efficiency. In addition, it is determined whether it is better to maintain the current shift speed without performing the downshift of the automatic transmission 18. The LTc reference range corresponds to the target engine operation range of the present invention when the power storage device 57 is charged. And since the said solid line LTc (refer FIG. 2) is set for every gear stage of the automatic transmission 18, the LTc reference | standard range which is the target engine operating range is also set for every said gear stage. The case where it is determined that the power storage device 57 needs to be charged will be described more specifically with reference to FIGS. 5 and 6.

FIGS. 5 and 6 show different driving states of the vehicle 8, and FIG. 5 shows an example in which the assumed engine operating point at the time of charging is within the LTc reference range at the current gear position of the automatic transmission 18. FIG. 6 shows an example in which the assumed engine operating point at the time of charging is out of the LTc reference range. 5 and 6, the maximum thermal efficiency line Litef and the solid line LTc are the same as those in FIG. 2, and the two-dot chain line is an isothermal efficiency line in which the engine thermal efficiency is equal. In addition, since a part of the engine power Pe is used for charging the power storage device 57 when the power storage device 57 is charged, the engine power Pe when the power storage device 57 is charged while the engine is running is calculated based on the travel power and the charge. It is the sum of power. That is, the engine power Pe is composed of the travel power that is the travel power and the charge power that is the charge power. The broken line L05 in FIG. 5 and the broken line L07 in FIG. 6 are different equal power curves representing the above-mentioned traveling power, and the broken line L06 in FIG. 5 and the broken line L08 in FIG. It is a different equal power curve to represent. 5 and 6, the magnitude of the charging power may be set to a predetermined value in advance, or may be changed according to the remaining charge SOC of the power storage device 57. The magnitude of the traveling power can be obtained based on the accelerator opening Acc and the vehicle speed V. 5 and 6, N1e means the current engine speed Ne, Tc means the engine torque Te indicated by the engine operating point when the engine speed Ne is N1e on the solid line LTc, and Tθ ₀ means the engine torque Te corresponding to the travel power when the engine speed Ne is N1e, and TΔθpc means the engine torque Te corresponding to the charge power when the engine speed Ne is N1e. Tθ ₀ + TΔθpc is the sum of Tθ ₀ and TΔθpc which are engine torque Te, that is, engine torque Te corresponding to engine power Pe when engine speed Ne is N1e and power storage device 57 is charged. Means. These N1e, Tc, Tθ ₀ , TΔθpc, and Td, TΔθpd described later have the same meanings in FIGS. 5 to 8, but the values are not the same.

For example, in FIG. 5 and FIG. 6, the engine operating point determination means 84 detects the current engine speed Ne (= N1e) and responds to the travel power based on the engine speed Ne (= N1e). The engine torque Te (= Tθ ₀ ), the engine torque Te (= TΔθpc) corresponding to the charged power, and the engine torque Te (= Tc) indicated by the engine operating point on the solid line LTc are obtained. Further, Tθ ₀ and TΔθpc are summed up, and the engine torque Te (= Tθ ₀ + TΔθpc) corresponding to the engine power Pe when the power storage device 57 is charged, that is, the assumed engine operating point during charging ( An engine torque Te indicated by a point PTch in FIGS. 5 and 6 is calculated. Then, the engine operating point determination means 84 calculates the engine torque Te (= Tc) indicated by the engine operating point on the solid line LTc and the engine torque Te (= Tθ ₀ + TΔθpc) indicated by the assumed engine operating point during charging. In comparison, if “Tc ≧ Tθ ₀ + TΔθpc” as shown in FIG. 5, it is determined that the assumed engine operating point at the time of charging falls within the LTc reference range. On the other hand, as shown in FIG. 6, if “Tc <Tθ ₀ + TΔθpc”, it is determined that the assumed engine operating point during charging is out of the LTc reference range.

  Next, the case where it is determined that the power storage device 57 needs to be discharged will be described. Specifically, when it is determined that the power storage device 57 needs to be discharged, the engine operating point determination unit 84 detects the engine rotation speed Ne, maintains the engine rotation speed Ne, and discharges the discharge. An engine operating point (hereinafter referred to as an assumed engine operating point at the time of discharge) when it is performed is obtained. That is, at the current gear position of the automatic transmission 18, an assumed engine operating point during discharge, which is an engine operating point determined from the traveling power and the discharge power output by the discharge, is obtained. The magnitude of the discharge power may be set to a predetermined value in advance, or may be changed according to the remaining charge SOC of power storage device 57. Then, the engine operating point determination means 84 determines whether or not the determined engine operating point at the time of discharge is located on the solid line LTd (see FIG. 3) or on the maximum thermal efficiency line Litef side from the solid line LTd, that is, It is determined whether or not the engine operating point at the time of discharge falls within the LTd reference range. Thus, the engine operating point determination means 84 determines whether the estimated engine operating point at the time of discharging falls within the LTd reference range, so that the power storage device 57 is discharged from the viewpoint of improving the engine thermal efficiency. Whether or not it is better to keep the current gear position without performing the upshift of the automatic transmission 18 is determined. The LTd reference range corresponds to the target engine operating range of the present invention when discharging the power storage device 57. That is, the target engine operating range of the present invention is predetermined for each of the case where the power storage device 57 is charged and the case where the power storage device 57 is discharged. And since the said solid line LTd (refer FIG. 3) is set for every gear stage of the automatic transmission 18, the LTd reference | standard range which is the target engine operating range is also set for every said gear stage. 7 and 8, the case where it is determined that the power storage device 57 needs to be discharged will be described more specifically.

FIGS. 7 and 8 show the running states of the vehicles 8 different from each other. FIG. 7 shows an example in which the engine operating point during discharge is within the LTd reference range at the current gear position of the automatic transmission 18. FIG. 8 shows an example in which the assumed engine operating point at the time of discharge is out of the LTd reference range. 7 and 8, the maximum thermal efficiency line Litef and the solid line LTd are the same as those in FIG. 3, and the two-dot chain line is an isothermal efficiency line in which the engine thermal efficiency is equal. Further, when the power storage device 57 is discharged, the engine power Pe added with the discharge power output from the electric motor MG becomes the running power. Therefore, the engine power Pe when the power storage device 57 is discharged while the engine is running is This is the driving power minus the discharge power. That is, the travel power (travel power) is composed of the engine power Pe and the discharge power that is the discharge power. The broken line L09 in FIG. 7 and the broken line L11 in FIG. 8 are different equal power curves representing the engine power Pe when the discharge is performed, and the broken line L10 in FIG. 7 and the broken line L12 in FIG. It is a different equal power curve to represent. 7 and 8, the magnitude of the discharge power may be set to a predetermined value in advance, or may be changed according to the remaining charge SOC of the power storage device 57. 7 and 8, N1e and Tθ ₀ have the same meaning as that shown in FIG. 5 or FIG. 6, and Td is the engine indicated by the engine operating point when the engine speed Ne is N1e on the solid line LTd. It means torque Te, Tiderutashitapd means engine torque Te corresponding to the discharge amount power when the engine rotational speed Ne is N1e, Tθ ₀ -TΔθpd was subtracted Tiderutashitapd from T.theta ₀ is an engine torque Te The difference, that is, the engine torque Te corresponding to the engine power Pe when the engine speed Ne is N1e and the power storage device 57 is discharged.

For example, in FIG. 7 and FIG. 8, the engine operating point determination means 84 detects the current engine speed Ne (= N1e) and responds to the travel power based on the engine speed Ne (= N1e). The engine torque Te (= Tθ ₀ ), the engine torque Te (= TΔθpd) corresponding to the discharge power, and the engine torque Te (= Td) indicated by the engine operating point on the solid line LTd are obtained. Furthermore, by subtracting the TΔθpd from the T.theta _0, the engine torque Te corresponding to the engine power Pe when the were subjected discharge of the power storage device 57 (= Tθ ₀ -TΔθpd), i.e., the discharge time of assuming the engine operating point (Fig. 7 and point PTdc in FIG. 8) is calculated. Then, the engine operating point determination means 84 includes an engine torque Te (= Td) indicated by the engine operating point on the solid line LTd, and an engine torque Te (= Tθ ₀ −TΔθpd) indicated by the assumed engine operating point during discharge. As shown in FIG. 7, if “Td ≦ Tθ ₀ −TΔθpd”, it is determined that the engine operating point during discharge is within the LTd reference range. On the other hand, as shown in FIG. 8, if “Td> Tθ ₀ −TΔθpd”, it is determined that the engine operating point at the time of discharge is out of the LTd reference range.

  The stepped shift control means 86 determines whether or not to shift the automatic transmission 18 in accordance with a predetermined shift diagram for shifting the automatic transmission 18 and shifts the automatic transmission 18. Execute. When the engine operating point determining unit 84 determines that the assumed engine operating point at the time of charging is out of the LTc reference range, or the stepped engine control point 86 is set to the LTd. If it is determined that the vehicle is out of the reference range, the total load amount is obtained by adding the load amount corresponding to the charge power or the discharge power to the vehicle required load amount required for the vehicle 8 as a positive direction when charging. Based on the shift diagram, it is determined whether or not the automatic transmission 18 is to be shifted. The load amount such as the vehicle required load amount may be specifically expressed by a throttle opening θth, an intake air amount of the engine 12, or a fuel injection amount, etc. It is composed of two-dimensional coordinates of the vehicle speed V and the accelerator opening Acc, the vehicle required load amount is represented by the actual accelerator opening Acc, and the load amount corresponding to the charging power or discharging power is the charging power. Alternatively, it is represented by a virtual accelerator opening Acc corresponding to the discharge power. The accelerator opening Acc corresponding to the charging power or discharging power is the magnitude of the accelerator opening Acc necessary for obtaining the engine power Pe having the same magnitude as the charging power or discharging power.

Specifically, a case where the engine operating point determination unit 84 determines that the assumed engine operating point during charging is out of the LTc reference range will be described with reference to FIG. FIG. 9 is an excerpt of the downshift line for determining that the automatic transmission 18 is to shift down from the current gear position to the low speed side by one gear. In FIG. 9, V1 indicates the current vehicle speed V detected by the vehicle speed sensor 68, and θ ₀ indicates the actual accelerator opening Acc detected by the accelerator opening sensor 60. Accordingly, the remains of the vehicle state (point PT0c) indicating and its V1 and theta ₀ in the shift diagram of FIG. 9, the current gear position is held. When the engine operating point determining unit 84 determines that the assumed engine operating point during charging is out of the LTc reference range, the stepped shift control unit 86 sets the actual accelerator opening Acc (= θ ₀ ) to A value obtained by adding a virtual accelerator opening Acc (= Δθpc) corresponding to the charging power (= θ ₀ + Δθpc) is determined as the accelerator opening Acc on the vertical axis in FIG. . That is, the shift of the automatic transmission 18 is determined assuming that Δθc in FIG. 9 is Δθpc. Then, the point PT0c representing the vehicle state changes to the point PT1c on the shift diagram in FIG. 9 and crosses the down shift line, so that the stepped shift control means 86 executes the down shift of the automatic transmission 18. Then, as shown in FIG. 6, the engine operating point after the start of charging of the power storage device 57 becomes point PTch when the downshift is not executed, but becomes point PT1ch when the downshift is executed. Compared to the case where the engine is not executed, the engine operating point approaches the maximum thermal efficiency line Litef and falls within the LTc reference range.

On the other hand, when the engine operating point determining unit 84 determines that the assumed engine operating point at the time of charging falls within the LTc reference range, the stepped shift control unit 86 determines the actual accelerator opening Acc (= the theta _0), without adding a virtual accelerator opening Acc corresponding to the charging power (= Δθpc), the shift of the automatic transmission 18 based on the actual accelerator opening Acc (= θ ₀₎ to decide. That is, the shift of the automatic transmission 18 is determined on the assumption that Δθc in FIG. 9 is zero. Then, the vehicle state remains at the point PT0c on the shift diagram of FIG. 9, so the stepped shift control means 86 holds the current shift stage of the automatic transmission 18. As shown in FIG. 5, the engine operating point becomes point PTch after the start of charging of power storage device 57, and falls within the LTc reference range. In this case, the fact that the engine operating point after the start of charging is separated from the maximum thermal efficiency line Litef due to the downshift of the automatic transmission 18 is avoided by not performing the downshift.

Next, a case where the engine operating point determination unit 84 determines that the assumed engine operating point during discharge is out of the LTd reference range will be described with reference to FIG. FIG. 10 is an excerpt of the upshift line for determining that the automatic transmission 18 is to be shifted up from the current gear position to the high speed side by one speed. V1 in Fig. 10, theta ₀ is V1 in FIG. 9, respectively, it does not mean that the size of the theta ₀ and values are the same, V1 of Fig. 10 shows the current vehicle speed V detected by the vehicle speed sensor 68, θ ₀ indicates the actual accelerator opening Acc detected by the accelerator opening sensor 60. Accordingly, the remains of the vehicle state (point PT0d) indicating and its V1 and theta ₀ in the shift diagram of FIG. 10, the current speed stage is maintained. When the engine operating point determining unit 84 determines that the assumed engine operating point during discharge is out of the LTd reference range, the stepped shift control unit 86 determines from the actual accelerator opening Acc (= θ ₀ ) The value (= θ ₀ −Δθpd) obtained by subtracting the virtual accelerator opening Acc (= Δθpd) corresponding to the discharge power is used as the accelerator opening Acc on the vertical axis in FIG. 10 to determine the shift of the automatic transmission 18. To do. That is, the shift of the automatic transmission 18 is determined assuming that Δθd in FIG. 10 is Δθpd. Then, the point PT0d representing the vehicle state changes to the point PT1d on the shift diagram of FIG. 10 and crosses the upshift line, so that the stepped shift control means 86 executes the upshift of the automatic transmission 18. As shown in FIG. 8, the engine operating point after the start of discharging of the power storage device 57 is the point PTdc when the upshift is not executed, but becomes the point PT1dc when the upshift is executed. Compared with the case where the engine is not executed, the engine operating point approaches the maximum thermal efficiency line Litef and falls within the LTd reference range.

On the other hand, when the engine operating point determining unit 84 determines that the assumed engine operating point at the time of discharging is within the LTd reference range, the stepped shift control unit 86 determines the actual accelerator opening Acc (= from theta _0), virtual accelerator opening Acc corresponding to the discharge power (= Δθpd) without subtracting the shift of the automatic transmission 18 based on the actual accelerator opening Acc (= θ ₀₎ to decide. That is, the shift of the automatic transmission 18 is determined on the assumption that Δθd in FIG. 10 is zero. Then, since the vehicle state remains at point PT0d on the shift diagram of FIG. 10, the stepped shift control means 86 holds the current shift stage of the automatic transmission 18. As shown in FIG. 7, the engine operating point becomes point PTdc after the start of discharging of power storage device 57, and falls within the LTd reference range. In this case, it is avoided that the engine operating point after the start of discharge is separated from the maximum thermal efficiency line Litef by the upshift of the automatic transmission 18 because the upshift is not performed.

  The drive control means 88 performs drive control of the engine 12 and the electric motor MG while the vehicle is traveling. Further, when charging or discharging the power storage device 57 in order to keep the remaining charge SOC of the power storage device 57 within the charge remaining amount management range, the driving force of the vehicle 8 does not give the driver a sense of incongruity. The battery is charged or discharged while maintaining Specifically, when the engine is traveling, the drive control unit 88 adds the charging power to the traveling power when the charging / discharging necessity determining unit 82 determines that the power storage device 57 needs to be charged. Engine power Pe having the added magnitude is generated in engine 12, charging power that is part of engine power Pe is regenerated in electric motor MG, and power storage device 57 is charged with the charging power. On the other hand, when it is determined by the charge / discharge necessity determining unit 82 that the power storage device 57 needs to be discharged, the drive control unit 88 is an engine having a size obtained by subtracting the discharge power from the traveling power. The power Pe is generated in the engine 12, the discharge power is generated in the electric motor MG, and the power storage device 57 is discharged by the electric power consumption of the electric motor MG generating the discharge power. Such output control of the engine 12 and the electric motor MG for charging or discharging the power storage device 57 may involve shifting of the automatic transmission 18 by the stepped shift control means 86, and in that case, charging or discharging thereof is performed. For example, the output control of the engine 12 and the electric motor MG may be started before the shift, after the shift, or may be started during the shift.

  FIG. 11 shows the main part of the control operation of the electronic control unit 58, that is, the automatic transmission 18 is shifted so as not to reduce the engine thermal efficiency when charging and discharging the power storage device 57 while maintaining the driving force of the vehicle 8. It is a flowchart for demonstrating the control action | operation to judge, for example, is repeatedly performed by the very short cycle time of about several msec thru | or several tens msec. The control operation shown in FIG. 11 is executed when the vehicle 8 is running on the engine. The control operation shown in FIG. 11 is executed alone or in parallel with other control operations.

  First, in step (hereinafter, “step” is omitted) SA1 in FIG. 11, it is determined whether or not the power storage device 57 needs to be charged. Specifically, it is determined whether or not it is necessary to forcibly charge the power storage device 57 based on the charge / discharge restriction set in advance for the power storage device 57. When the determination of SA1 is affirmed, that is, when it is necessary to forcibly charge the power storage device 57, the process proceeds to SA2. On the other hand, if the determination at SA1 is negative, the operation goes to SA5. SA1 corresponds to the charge / discharge necessity determining means 82.

In SA2 corresponding to the engine operating point determination means 84, it is determined whether or not the assumed engine operating point during charging falls within the LTc reference range. Specifically, “Tc− (Tθ ₀ + TΔθpc)” is calculated from the Tc, Tθ ₀ , and TΔθpc shown in FIG. 5 or FIG. 6, and when the calculated value is zero or more, It is determined that the assumed engine operating point falls within the LTc reference range. If the determination of SA2 is affirmative, that is, if the assumed engine operating point during charging falls within the LTc reference range, the process proceeds to SA3. On the other hand, if the determination at SA2 is negative, the operation goes to SA4.

In SA3, the accelerator opening Acc on the vertical axis in FIG. 9, that is, the accelerator opening Acc used for shift determination in the shift diagram is set as the actual accelerator opening Acc (= θ ₀ ). A shift is determined. Therefore, the automatic transmission 18 is not shifted due to the charging of the power storage device 57 by the charge / discharge restriction.

In SA4, the accelerator opening Acc used for shift determination in the shift map is set to a virtual accelerator opening Acc (= Δθpc) corresponding to the charging power to the actual accelerator opening Acc (= θ ₀ ). In addition, the obtained value (= θ ₀ + Δθpc) is used to determine the shift of the automatic transmission 18. Accordingly, as shown in FIG. 9, the point PT0c representing the vehicle state changes to the point PT1c on the shift diagram and crosses the down shift line, so that the downshift of the automatic transmission 18 is executed. SA3 and SA4 correspond to the stepped shift control means 86.

  In SA5 corresponding to the charge / discharge necessity determining means 82, it is determined whether or not the power storage device 57 needs to be discharged. Specifically, it is determined whether or not it is necessary to forcibly discharge the power storage device 57 based on the charge / discharge restriction set in advance for the power storage device 57. If the determination of SA5 is affirmative, that is, if it is necessary to forcibly discharge the power storage device 57, the process proceeds to SA6. On the other hand, if the determination at SA5 is negative, the operation proceeds to SA9.

In SA6 corresponding to the engine operating point determination means 84, it is determined whether or not the assumed engine operating point at the time of discharge falls within the LTd reference range. Specifically, “Td− (Tθ ₀ −TΔθpd)” is calculated from the Td, Tθ ₀ , and TΔθpd shown in FIG. 7 or FIG. 8, and when the calculated value is less than or equal to zero, the discharge It is determined that the assumed engine operating point falls within the LTd reference range. If the determination at SA6 is affirmative, that is, if the assumed engine operating point during discharge falls within the LTd reference range, the process proceeds to SA7. On the other hand, if the determination at SA6 is negative, the operation goes to SA8.

In SA7, the accelerator opening Acc on the vertical axis in FIG. 10, that is, the accelerator opening Acc used for shift determination in the shift diagram is set as the actual accelerator opening Acc (= θ ₀ ). A shift is determined. Therefore, the automatic transmission 18 is not shifted due to the discharge of the power storage device 57 due to the charge / discharge restriction.

In SA8, the accelerator opening Acc used for shift determination in the shift diagram is a virtual accelerator opening Acc (= Δθpd) corresponding to the discharge power from the actual accelerator opening Acc (= θ ₀ ). The value obtained by subtraction (= θ ₀ −Δθpd) is used to determine the shift of the automatic transmission 18. Therefore, as shown in FIG. 10, the point PT0d representing the vehicle state changes to the point PT1d on the shift diagram and crosses the up shift line, so that the upshift of the automatic transmission 18 is executed.

In SA9, the accelerator opening Acc used for shift determination in the shift diagram is set to the actual accelerator opening Acc (= θ ₀ ), and the shift of the automatic transmission 18 is determined. SA7, SA8, and SA9 correspond to the stepped shift control means 86.

  According to the above-described embodiment, when it is determined by the charge / discharge necessity determination means 82 that it is necessary to charge the power storage device 57, that is, the power storage device 57 is charged while maintaining the driving force of the vehicle 8. When performing, as shown in FIGS. 5 and 6, the electronic control unit 58 determines the engine operating point so that the engine operating point at the time of charging falls within the LTc reference range. Further, when it is determined by the charge / discharge necessity determining means 82 that it is necessary to discharge the power storage device 57, that is, when the power storage device 57 is discharged while maintaining the driving force of the vehicle 8, FIG. As shown in FIG. 8, the electronic control unit 58 determines the engine operating point so that the engine operating point during discharge falls within the LTd reference range. The LTc reference range corresponds to the target engine operating range that is predetermined based on the maximum thermal efficiency line Litef when the power storage device 57 is charged, and the LTd reference range is the discharge of the power storage device 57. This corresponds to the target engine operating range in the case of performing. In short, when the electronic control unit 58 charges or discharges the power storage device 57 while maintaining the driving force of the vehicle 8, the target engine operation in which the engine operating point is predetermined based on the maximum thermal efficiency line Litef. The engine operating point is determined to be within the range. Therefore, since the power storage device 57 can be charged or discharged while suppressing the deterioration of engine thermal efficiency to some extent, the power storage device 57 can be appropriately charged / discharged while suppressing the deterioration of the fuel consumption of the vehicle 8.

  Further, according to this embodiment, the electronic control device 58 charges the power storage device 57 while maintaining the driving force of the vehicle 8, and the engine operating point (assumed engine at the time of charging) determined from the running power and the charging power. If the operating point is out of the LTc reference range at the current gear position of the automatic transmission 18, the engine operating point is shifted to the LTc reference range by downshifting the automatic transmission 18, as shown in FIG. Put in. On the other hand, when the assumed engine operating point at the time of charging falls within the LTc reference range at the current shift stage of the automatic transmission 18, the current shift stage of the automatic transmission 18 is maintained. In addition, when the electronic control unit 58 discharges the power storage device 57 while maintaining the driving force of the vehicle 8, the engine operating point (the engine operating point at the time of discharging) determined from the traveling power and the discharging power is automatically changed. If the current gear position of the machine 18 is out of the LTd reference range, as shown in FIG. 8, the automatic transmission 18 is shifted up to bring the engine operating point into the LTd reference range. On the other hand, when the assumed engine operating point at the time of discharge falls within the LTd reference range at the current shift stage of the automatic transmission 18, the current shift stage of the automatic transmission 18 is maintained. Therefore, since the automatic transmission 18 is not shifted so as to deteriorate the engine thermal efficiency as the power storage device 57 is charged or discharged, the fuel consumption is reduced due to the shift of the automatic transmission 18. The situation of getting worse can be avoided. That is, it is possible to appropriately charge and discharge the power storage device 57 while suppressing deterioration in fuel consumption. Further, the gear position of the automatic transmission 18 is appropriately selected from the viewpoint of suppressing deterioration in fuel consumption with respect to the engine power Pe determined according to the state of charge of the power storage device 57.

  Further, according to the present embodiment, when the assumed engine operating point at the time of charging deviates from the LTc reference range at the current gear position of the automatic transmission 18, or when the assumed engine operating point at the time of discharging is the automatic transmission 18 When the current shift stage is out of the LTd reference range, as shown in FIGS. 9 and 10, the electronic control unit 58 adds the charging power or the vehicle required load amount required for the vehicle 8 to the vehicle required load amount. Whether or not to shift the automatic transmission 18 is determined from the shift diagram based on the total load amount obtained by adding the load amount corresponding to the discharge power in the positive direction when charging. Therefore, whether or not the power storage device 57 is charged or discharged, the automatic transmission 18 can be shifted using the common shift diagram, and the control load can be reduced.

Further, according to this embodiment, as shown in FIGS. 9 and 10, the shift diagram is composed of two-dimensional coordinates of the vehicle speed V and the accelerator opening degree Acc, and the vehicle required load amount is actually represented by the accelerator opening Acc (= θ _0), the load amount corresponding to the charging power is represented by a virtual accelerator opening Acc corresponding to the charging power (= Δθpc), corresponding to the discharge power The amount of load to be expressed is represented by a virtual accelerator opening Acc (= Δθpd) corresponding to the discharge power. Therefore, it is possible to determine whether or not the automatic transmission 18 is to be shifted based on the vehicle speed V and the accelerator opening Acc, and both the vehicle speed V and the accelerator opening Acc can be easily detected by the sensors 68, 60, and the like. Therefore, it is possible to easily determine whether or not to shift the automatic transmission 18 when charging or discharging the power storage device 57 while maintaining the driving force of the vehicle 8.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

  For example, in the above-described embodiment, the automatic transmission 18 is a stepped automatic transmission. However, the automatic transmission 18 may be an automatic transmission that performs clutch-to-clutch shifting by changing the engagement element. There is no problem even if the CVT is an equation or the like, and the gear ratio of the CVT is changed stepwise.

  In FIG. 1 of the above-described embodiment, the electric motor MG is connected to the pump impeller 16p of the torque converter 16. However, the electric motor MG may be connected to the transmission output shaft 20 instead of the pump impeller 16p. There is no problem.

  In the above-described embodiment, the torque converter 16 includes the lockup clutch LU. However, the torque converter 16 may not include the lockup clutch LU. Further, the torque converter 16 is not essential.

  In the above-described embodiment, since the vehicle drive device 10 includes the engine intermittent clutch K0, the vehicle 8 can perform the motor travel, but it is not essential that the motor travel can be performed. The engine intermittent clutch K0 is not provided, and the engine output shaft 26 may be always connected to the rotor 30 of the electric motor MG so as not to be relatively rotatable.

  In the above-described embodiment, the charging power or discharging power for charging or discharging the power storage device 57 while maintaining the driving force of the vehicle 8 is the driving force of the vehicle 8 regardless of whether the charging or discharging is performed. Is preferably determined in consideration of the power loss of each element such as the electric motor MG.

  In the above-described embodiment, the downshift of the automatic transmission 18 executed when the power storage device 57 is charged while maintaining the driving force of the vehicle 8 is such that the engine operating point at the time of charging is the highest thermal efficiency of the engine 12. It can be executed multiple times until it approaches the line Ltef. The same applies to the upshift of the automatic transmission 18 that is executed when the power storage device 57 is discharged while maintaining the driving force of the vehicle 8.

8: Hybrid vehicle (vehicle)
12: Engine 18: Automatic transmission 24: Drive wheel 57: Power storage device 58: Electronic control device (vehicle drive control device)
MG: Electric motor

Claims (5)

A vehicle including a stepped automatic transmission that constitutes a part of a power transmission path from an engine to a drive wheel, an electric motor coupled to the power transmission path, and a power storage device electrically connected to the electric motor In this case, when charging the power storage device, a part of the engine power is regenerated in the electric motor, and when discharging the power storage device, the vehicle drive control for driving the motor to consume power A device,
When charging or discharging the power storage device while maintaining the driving force of the vehicle, the operating point of the engine is within a predetermined target engine operating range based on the maximum thermal efficiency line of the engine. A drive control device for a vehicle, characterized in that an operating point of the engine is determined. When charging or discharging the power storage device while maintaining the driving force of the vehicle, the operating point of the engine determined from running power and charging power or discharging power is the current shift stage of the automatic transmission. When out of the target engine operating range, shifting the automatic transmission causes the engine operating point to fall within the target engine operating range while the engine operating point is within the current transmission of the automatic transmission. 2. The vehicle drive control device according to claim 1, wherein a current shift speed of the automatic transmission is maintained when the shift speed falls within the target engine operation range. 3. A shift diagram for performing a shift of the automatic transmission is predetermined,
The vehicle request required for the vehicle when the operating point of the engine determined from the running power and the charging power or discharging power is out of the target engine operating range at the current gear position of the automatic transmission. Based on a total load amount obtained by adding a load amount corresponding to the charging power or discharging power as a positive direction to the load amount, it is determined whether or not to shift the automatic transmission from the shift diagram. The vehicle drive control device according to claim 2. The shift diagram is composed of two-dimensional coordinates of the vehicle speed and the accelerator opening,
The vehicle required load amount is represented by an actual accelerator opening,
The vehicle drive control device according to claim 3, wherein the load amount corresponding to the charging power or discharging power is represented by a virtual accelerator opening corresponding to the charging power or discharging power. The shift of the automatic transmission that is performed when charging the power storage device is a down shift, and the shift of the automatic transmission that is performed when discharging the power storage device is an up shift. The vehicle drive control device according to any one of claims 2 to 4.

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