JP2014069667A - Driving device of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent driving force from becoming insufficient during reverse traveling.SOLUTION: A driving device 10 comprises a clutch (CL1) capable of switching between a connection state in which driving wheels 42f, 42r and a power division mechanism 12 are connected and a disconnection state in which the driving wheels and the power division mechanism are disconnected. The driving device further comprises a clutch (CL3) capable of switching between an engaging state in which a plurality of rotary elements constituting the power division mechanism are integrally rotated and a disengaging state in which the plurality of rotary elements are individually rotated. A vehicle control unit includes as traveling modes: an EV mode in which the clutch (CL1) is released and the clutch (CL3) is released; a series mode in which the clutch (CL1) is released and the clutch (CL3) is engaged; and a power division mode in which the clutch (CL1) is engaged and the clutch (CL3) is released. The vehicle control unit sets one of the EV mode and the series mode during reverse traveling.

Description

  The present invention relates to a drive device for a hybrid vehicle including a power split mechanism.

  A hybrid vehicle having a power split mechanism composed of a planetary gear train or the like has been developed (see Patent Document 1). An engine, a motor generator, and driving wheels are connected to each rotating element of such a power split mechanism. In addition, a clutch or a brake for controlling the operating state of the power split mechanism is connected to each rotating element of the power split mechanism. The driving mode of the hybrid vehicle can be switched by controlling the clutch and brake of the power split mechanism. For example, it is possible to output the engine power continuously variable by controlling the number of revolutions of the motor generator under the condition that the clutch and the brake are released and the constraint between the rotating elements is released. . In addition, it is possible to output the engine power at a constant speed or increase / decrease speed by fastening the clutch and rotating each rotating element integrally, or by fastening the brake and fixing a specific rotating element. Become.

JP 2005-313757 A

  By the way, when the constraint of each rotating element of the power split mechanism is released, the engine power can be continuously variable, but the engine power is divided into the drive wheels and the motor generator. That is, releasing the restraint of each rotating element of the power split mechanism is a factor for reducing the driving force of the hybrid vehicle. In particular, since the rotational direction of the engine is determined, it is difficult to obtain a driving force necessary for reverse travel when the gear ratio of the power split mechanism is set in accordance with forward travel.

  An object of the present invention is to prevent driving force from being insufficient during reverse running.

  A hybrid vehicle drive device of the present invention includes a first motor generator coupled to drive wheels, a motor power system for transmitting motor power from the first motor generator to the drive wheels, an engine, a second motor generator, An engine power system that includes a power split mechanism coupled to the drive wheels and that transmits engine power from the engine to the drive wheels via the power split mechanism; and provided between the drive wheels and the power split mechanism Provided in the power split mechanism, a first clutch mechanism that is switched between a fastening state for connecting the drive wheel and the power split mechanism and a release state for disconnecting the drive wheel and the power split mechanism, A fastening state in which a plurality of rotating elements constituting the power split mechanism are rotated together and a released state in which the plurality of rotating elements are individually rotated. A second clutch mechanism that is switched, and a travel mode control unit that controls the first clutch mechanism and the second clutch mechanism, wherein the travel mode control unit sets the first clutch mechanism as a travel mode. A first mode for releasing and releasing the second clutch mechanism; a second mode for releasing the first clutch mechanism and fastening the second clutch mechanism; and a second mode for fastening the first clutch mechanism and the second mode. A third mode for releasing the clutch mechanism, wherein the travel mode control unit sets one of the first mode and the second mode during reverse travel.

  According to the present invention, since one of the first mode and the second mode is set at the time of reverse travel, setting of the third mode at the time of reverse travel can be avoided, and driving force is insufficient at the time of reverse travel. It becomes possible to prevent.

It is the schematic which shows the drive device of the hybrid vehicle which is one embodiment of this invention. It is a block diagram which shows the control system of a drive device. It is explanatory drawing which shows the operating state of the clutch in each driving mode, a motor generator, and an engine. It is explanatory drawing which shows the switching order of each driving mode. (a) And (b) is the schematic and collinear diagram which show the operating state of the drive device in series mode. (a) And (b) is the schematic and collinear diagram which show the operating state of the drive device in EV mode. (a) And (b) is the schematic and collinear diagram which show the operating state of the drive device in PS1 mode. (a) And (b) is the schematic and collinear diagram which show the operating state of the drive device in PS2 mode. (a) And (b) is the schematic and collinear diagram which show the operating state of the drive device in OD1 mode. (a) And (b) is the schematic and collinear diagram which show the operating state of the drive device in OD2 mode. (a) And (b) is the schematic and collinear diagram which show the operating state of the drive device in direct connection mode. It is a flowchart which shows an example of the setting procedure of the running mode at the time of reverse running. It is explanatory drawing which shows the reverse running condition of a hybrid vehicle. (a)-(c) is explanatory drawing which shows the setting condition of the driving mode in reverse driving | running | working. It is a mode map which shows an example of the setting area | region of each driving mode. It is explanatory drawing which shows the driving | running | working condition of the hybrid vehicle which starts a forward drive from reverse drive.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a hybrid vehicle drive apparatus 10 according to an embodiment of the present invention. As shown in FIG. 1, a drive device 10 mounted on a hybrid vehicle includes an engine 11 that is an internal combustion engine as a power source. In addition, the drive device 10 includes a first motor generator M1 and a second motor generator M2 as power sources.

  A power split mechanism 12 constituted by a planetary gear train is provided between the engine 11 and the second motor generator M2. The power split mechanism 12 includes a carrier 15 connected to the crankshaft 13 of the engine 11 via a damper mechanism 14 and a pinion gear 16 that is rotatably supported by the carrier 15. The pinion gear 16 is formed with a first gear portion 16a and a second gear portion 16b, and the first gear portion 16a and the second gear portion 16b are arranged coaxially. The first sun gear 17 is engaged with the first gear portion 16a, and the second sun gear 18 is engaged with the second gear portion 16b. A rotor 20 a of a motor generator M 2 is connected to the first sun gear 17 via a motor output shaft 19, and a synchro hub 22 is fixed to the second sun gear 18 via a hollow shaft 21. A ring gear 23 is engaged with the first gear portion 16 a of the pinion gear 16, and spline teeth 25 are fixed to the ring gear 23 via a hollow shaft 24. Further, spline teeth 27 are fixed to the case 26 of the driving device 10. As described above, the power split mechanism 12 includes the carrier 15, the pinion gear 16, the first sun gear 17, the second sun gear 18, and the ring gear 23 as rotating elements.

  As shown in FIG. 1, a synchro sleeve 30 is engaged with the outer peripheral portion of the synchro hub 22 so as to be movable in the axial direction. A fork member 31 is attached to the sync sleeve 30, and the fork member 31 is connected to an extendable rod 32 a of the actuator 32. The sync sleeve 30 can be engaged with the spline teeth 25 by moving the sync sleeve 30 in the direction of arrow a. As a result, the second sun gear 18 and the ring gear 23 can be fastened via the sync sleeve 30. On the other hand, the synchro sleeve 30 can be engaged with the spline teeth 27 by moving the synchro sleeve 30 in the direction of arrow b. As a result, the second sun gear 18 and the case 26 can be fastened via the sync sleeve 30. Further, by moving the sync sleeve 30 to the neutral position shown in FIG. 1, the sync sleeve 30 is engaged with only the sync hub 22.

  A clutch (second clutch mechanism) CL3 that is switched between a fastening state in which the second sun gear 18 and the ring gear 23 are fastened and a release state in which the fastening is released is constituted by the synchro hub 22, the spline teeth 25, and the synchro sleeve 30. Has been. By fastening the clutch CL3, the second sun gear 18 and the ring gear 23 can be fastened, and a plurality of rotating elements constituting the power split mechanism 12 can be rotated integrally. On the other hand, by releasing the clutch CL3, the second sun gear 18 and the ring gear 23 can be released, and a plurality of rotating elements constituting the power split mechanism 12 can be individually rotated. Further, the synchro hub 22, the spline teeth 27, and the synchro sleeve 30 constitute a clutch CL4 that is switched between a fastening state in which the second sun gear 18 and the case 26 are fastened and a released state in which the fastening is released. The clutch CL4 functions as a brake mechanism that fixes the sun gear 18 to the case 26.

  These clutches CL3 and CL4 have one sync sleeve 30 shared. By sliding the synchro sleeve 30 by the actuator 32, the operating states of both clutches CL3 and CL4 can be switched. That is, by moving the synchro sleeve 30 in the arrow a direction, the clutch CL3 can be switched to the engaged state, and the clutch CL4 can be switched to the released state. Further, by moving the synchro sleeve 30 to the neutral position shown in FIG. 1, both the clutches CL3 and CL4 can be switched to the released state. Further, by moving the sync sleeve 30 in the direction of the arrow b, the clutch CL4 can be switched to the engaged state, and the clutch CL3 can be switched to the released state.

  As shown in FIG. 1, a drive gear 33 is fixed to the hollow shaft 24 that connects the ring gear 23 and the spline teeth 25, and a driven gear 34 that meshes with the drive gear 33 is parallel to the hollow shaft 24. The shaft 35 is rotatably supported. Spline teeth 36 are fixed to the driven gear 34, and a synchro hub 37 adjacent to the spline teeth 36 is fixed to the front wheel output shaft 35. A synchro sleeve 38 is engaged with the outer peripheral portion of the synchro hub 37 so as to be movable in the axial direction. A fork member 39 is attached to the synchro sleeve 38, and the fork member 39 is connected to the telescopic rod 40 a of the actuator 40. By moving the synchro sleeve 38 in the direction of arrow a by the actuator 40, the synchro sleeve 38 can be engaged with the spline teeth 36. As a result, the ring gear 23 and the front wheel output shaft 35 can be connected via the synchro sleeve 38. On the other hand, by moving the synchro sleeve 38 to the neutral position shown in FIG. 1, the synchro sleeve 38 can be engaged with only the synchro hub 37, and the ring gear 23 can be disconnected from the front wheel output shaft 35. In this manner, the clutch (first clutch mechanism) CL1 including the synchro hub 37, the spline teeth 36, and the synchro sleeve 38 is provided between the front wheel output shaft 35 and the driven gear 34. A differential mechanism 41 is connected to one end of the front wheel output shaft 35, and the front wheel output shaft 35 is connected to a front wheel 42 f as a drive wheel via the differential mechanism 41.

  A driven gear 43 is fixed to the other end of the front wheel output shaft 35, and a drive gear 44 that meshes with the driven gear 43 is fixed to a hollow shaft 45 that is parallel to the front wheel output shaft 35. A synchro hub 46 is fixed to the hollow shaft 45, and spline teeth 47 adjacent to the synchro hub 46 are fixed to the motor output shaft 48 of the motor generator M1. A synchro sleeve 49 meshes with the outer peripheral portion of the synchro hub 46 so as to be movable in the axial direction. A fork member 50 is attached to the sync sleeve 49, and the fork member 50 is connected to the telescopic rod 51 a of the actuator 51. The sync sleeve 49 can be engaged with the spline teeth 47 by moving the sync sleeve 49 in the arrow a direction by the actuator 51. Thereby, the rotor 52a of the motor generator M1 can be connected to the front wheel output shaft 35 via the sync sleeve 49. On the other hand, by moving the synchro sleeve 49 to the neutral position shown in FIG. 1, the synchro sleeve 49 can be engaged with only the synchro hub 46, and the motor generator M <b> 1 can be disconnected from the front wheel output shaft 35. As described above, the clutch CL 2 including the sync hub 46, the spline teeth 47, and the sync sleeve 49 is provided between the motor generator M 1 and the drive gear 44. A drive gear 60 is fixed to one end of the front wheel output shaft 35, and a driven gear 61 that meshes with the drive gear 60 is fixed to a rear wheel output shaft 62 that is parallel to the front wheel output shaft 35. A rear wheel output shaft 62 that passes through the center of the motor generator M1 and extends rearward is connected to a rear wheel 42r as a drive wheel via a transfer clutch 63 and the like.

  As described above, the drive device 10 is provided with the motor generator M1 coupled to the drive wheels 42f and 42r. The motor generator M1, the clutch CL2, the front wheel output shaft 35, the rear wheel output shaft 62, and the like constitute a motor power system Xm that transmits motor power to the drive wheels 42f and 42r. The drive device 10 is provided with a power split mechanism 12 connected to the engine 11, the second motor generator M2, and the drive wheels 42f and 42r. An engine power system that transmits engine power to the drive wheels 42f and 42r by the engine 11, the second motor generator M2, the power split mechanism 12, the clutches CL1, CL3, and CL4, the front wheel output shaft 35, the rear wheel output shaft 62, and the like. Xe is configured.

  Next, FIG. 2 is a block diagram showing a control system of the driving apparatus 10. As shown in FIG. 2, an inverter 64 is connected to the stator 52b of the motor generator M1, and an inverter 65 is connected to the stator 20b of the motor generator M2. Further, a battery 68 is connected to both the inverters 64 and 65 via energization lines 66 and 67. The hybrid vehicle is provided with a motor control unit 70 that controls the torque and rotation speed (rotation speed) of the motor generators M1 and M2 that function as an electric motor and a generator. The motor control unit 70 sets a control signal based on a motor power request value from a vehicle control unit 73 described later, and outputs a control signal to the inverters 64 and 65 so as to obtain this motor power request value. Further, the hybrid vehicle is provided with a battery control unit 71 that monitors the state of charge SOC, current, voltage, temperature, and the like of the battery 68. Further, the hybrid vehicle is provided with an engine control unit 72 that controls the torque and the rotational speed (rotational speed) of the engine 11. The engine control unit 72 sets a control signal based on the engine power request value from the vehicle control unit 73, and outputs the control signal to a throttle valve, an injector, etc. (not shown) so as to obtain this engine power request value.

  The hybrid vehicle is provided with a vehicle control unit (running mode control unit) 73 for overall control of the control units 70 to 72 and for controlling the actuators 32, 40, 51, the transfer clutch 63, and the like. Yes. The vehicle control unit 73 includes an inhibitor switch 74 for detecting the operation state of the select lever, an accelerator pedal sensor 75 for detecting the operation state of the accelerator pedal by the occupant, a brake pedal sensor 76 for detecting the operation state of the brake pedal by the occupant, and the vehicle speed. A vehicle speed sensor 77 or the like for detecting is connected. The vehicle control unit 73 determines a vehicle state (required driving force, vehicle speed, etc.) based on information from the various sensors 74 to 77, and sets a traveling mode according to the vehicle state based on a predetermined mode map, a control program, and the like. To do. The vehicle control unit 73 sets engine power and motor power according to the vehicle state and the travel mode, and outputs control signals to the control units 70 to 72, the actuators 32, 40, 51, and the like. The control units 70 to 73 are connected to each other via a communication network 78. Each control unit 70 to 73 is configured by a CPU, a ROM, a RAM, and the like.

  The required driving force used to determine the driving mode, that is, the driving force required by the occupant for the vehicle, is based on the accelerator pedal depression amount, the accelerator pedal depression speed, the throttle valve opening, the intake pipe negative pressure, etc. Calculated. For example, when the amount of depression of the accelerator pedal is large, the required driving force is calculated to be large, while when the amount of depression of the accelerator pedal is small, the required driving force is calculated to be small. Further, when the accelerator pedal depressing speed is high, the required driving force is calculated to be large, while when the accelerator pedal depressing speed is low, the required driving force is calculated to be small. When the throttle valve opening is large, the required driving force is calculated to be large, while when the throttle valve opening is small, the required driving force is calculated to be small. When the intake pipe negative pressure is large (when the intake pipe pressure is low), the required driving force is calculated to be large, while when the intake pipe negative pressure is small (when the intake pipe pressure is high), the required drive force is calculated. Calculated smaller. When calculating the required driving force, it is calculated based on one or more pieces of information such as the accelerator pedal depression amount, the accelerator pedal depression speed, the throttle valve opening, and the intake pipe negative pressure. Is possible.

Next, each travel mode set according to the vehicle state will be described. FIG. 3 is an explanatory diagram showing operating states of the clutches CL1 to CL4, the motor generators M1 and M2, and the engine 11 in each travel mode. FIG. 4 is an explanatory diagram showing the switching order of each travel mode. FIGS. 5A and 5B are a schematic diagram and a collinear diagram showing the operating state of the driving apparatus 10 in the series mode. FIGS. 6A and 6B are a schematic diagram and a collinear diagram showing the operating state of the driving apparatus 10 in the EV mode. FIGS. 7A and 7B are a schematic diagram and a collinear diagram showing the operating state of the driving apparatus 10 in the PS1 mode. FIGS. 8A and 8B are a schematic diagram and a collinear diagram showing the operating state of the driving apparatus 10 in the PS2 mode. FIGS. 9A and 9B are a schematic diagram and a collinear diagram showing an operating state of the driving apparatus 10 in the OD1 mode. FIGS. 10A and 10B are a schematic diagram and a collinear diagram showing an operating state of the driving apparatus 10 in the OD2 mode. FIGS. 11A and 11B are a schematic diagram and a collinear diagram showing the operating state of the drive device 10 in the direct connection mode. In the schematic diagrams of FIGS. 5A to 11A, the damper mechanism 14, the rear wheel output shaft 62, and the transfer clutch 63 are omitted. Further, in the diagram of FIG 5 (b) ~ FIG 11 (b), reference numeral S _alpha denotes a first sun gear 17, reference numeral S _beta denotes the second sun gear 18, reference numeral C denotes the carrier 15, the reference numeral R indicates the ring gear 23.

  As shown in FIGS. 3 and 4, in the illustrated hybrid vehicle, as a travel mode, series mode (second mode), EV mode (first mode), PS1 mode (third mode, power split mode), PS2 Seven driving modes are set: a mode, an OD1 mode, an OD2 mode, and a direct connection mode.

  As shown in FIGS. 3 and 5, in the series mode, the clutches CL2 and CL3 are engaged and the clutches CL1 and CL4 are released. That is, in the series mode that is the second mode, the clutch CL1 as the first clutch mechanism is released, and the clutch CL3 as the second clutch mechanism is engaged. Thus, by controlling the clutches CL <b> 1 to CL <b> 4, the motor generator M <b> 1 is connected to the front wheel output shaft 35, while the power split mechanism 12 is disconnected from the front wheel output shaft 35. In addition, since second sun gear 18 and ring gear 23 are fastened, engine 11 and motor generator M2 are directly connected via power split mechanism 12. This series mode is, for example, a travel mode that is set when the vehicle speed is low and the required driving force is large. By setting the series mode, it is possible to run using the motor power of the motor generator M1 while generating the motor generator M2 with the engine power. Thereby, a large amount of electric power can be supplied to motor generator M1, and a large motor torque can be obtained. In the series mode, the power split mechanism 12 is disconnected from the front wheel output shaft 35, so that the motor generator M2 can generate power even when the vehicle is stopped.

  When the required driving force decreases during traveling in the series mode, the mode is switched to the EV mode in which the power generation of the motor generator M2 is stopped. As shown in FIGS. 3 and 6, in the EV mode, the clutch CL2 is engaged and the clutches CL1, CL3, and CL4 are released. That is, in the EV mode that is the first mode, the clutch CL1 as the first clutch mechanism is released, and the clutch CL3 as the second clutch mechanism is released. By setting this EV mode, the engine 11 can be stopped as the required driving force decreases, and the fuel efficiency of the hybrid vehicle can be improved.

  As shown in FIGS. 3 and 7, in the PS1 mode, also called the power split mode, the clutches CL1 and CL2 are engaged and the clutches CL3 and CL4 are released. That is, in the PS1 mode that is the third mode, the clutch CL1 as the first clutch mechanism is engaged, and the clutch CL3 as the second clutch mechanism is released. Thus, by controlling the clutches CL <b> 1 to CL <b> 4, the motor generator M <b> 1 is connected to the front wheel output shaft 35 and the power split mechanism 12 is connected to the front wheel output shaft 35. Further, since the constraints on the second sun gear 18 and the ring gear 23 are released, the engine power is distributed to the ring gear 23 and the motor generator M2 via the power split mechanism 12, and the ring gear 23 is controlled by controlling the rotational speed of the motor generator M2. Continuously variable transmission becomes possible. The PS1 mode is a travel mode that is set when, for example, the vehicle speed range is low and the required driving force is large. By setting the PS1 mode, it is possible to drive the hybrid vehicle while transmitting the engine power to the front wheel output shaft 35 while continuously shifting the engine power and transmitting the motor power of the motor generator M1 to the front wheel output shaft 35. Become.

  When the vehicle travels in the PS1 mode and reaches the high vehicle speed range, the mode is switched to the PS2 mode in which the motor generator M1 is separated from the front wheel output shaft 35 and travels. As shown in FIGS. 3 and 8, when switching from the PS1 mode to the PS2 mode, the clutch CL2 is released from the state of the PS1 mode and the motor generator M1 is stopped. By setting the PS2 mode, the motor generator M1 can be disconnected from the drive wheels 42f and 42r in the high vehicle speed region. Thereby, the drag loss of motor generator M1 can be eliminated, and the fuel efficiency of the hybrid vehicle can be improved.

  As shown in FIGS. 3 and 9, in the OD1 mode, which is also called the overdrive mode, the clutches CL1, CL2, CL4 are engaged and the clutch CL3 is released. Thus, motor generator M1 is connected to front wheel output shaft 35, and power split mechanism 12 is connected to front wheel output shaft 35. Further, since the second sun gear 18 is fixed to the case 26, the engine power can be increased at a fixed gear ratio and transmitted to the ring gear 23. This OD1 mode is, for example, a travel mode that is set when the medium vehicle speed region and the required driving force are small. By setting the OD1 mode, it is possible to drive the hybrid vehicle while transmitting the engine power to the front wheel output shaft 35 while increasing the engine power and transmitting the motor power of the motor generator M1 to the front wheel output shaft 35. .

  When the vehicle travels in the OD1 mode and reaches a high vehicle speed range, the mode is switched to the OD2 mode in which the motor generator M1 is disconnected from the front wheel output shaft 35 for traveling. As shown in FIGS. 3 and 10, when switching from the OD1 mode to the OD2 mode, the clutch CL2 is released from the state of the OD1 mode and the motor generator M1 is stopped. By setting the OD2 mode, the motor generator M1 can be disconnected from the drive wheels 42f and 42r in the high vehicle speed region. Thereby, the drag loss of motor generator M1 can be eliminated, and the fuel efficiency of the hybrid vehicle can be improved.

  As shown in FIGS. 3 and 11, in the direct connection mode, the clutches CL1 and CL3 are engaged and the clutches CL2 and CL4 are released. As a result, the power split mechanism 12 is connected to the front wheel output shaft 35. Further, since second sun gear 18 and ring gear 23 are fastened, engine 11 and motor generator M2 are directly connected via power split mechanism 12. This direct connection mode is, for example, a travel mode that is set when the vehicle speed is high and the required driving force is large. By setting the direct connection mode, it is possible to increase, that is, downshift, the gear ratio as compared with the above-described OD1 mode and OD2 mode. That is, in the direct connection mode, the engine power can be transmitted to the front wheel output shaft 35 at a constant speed, so that the hybrid vehicle can be driven with a large driving force. In the direct connection mode executed in the high vehicle speed region, the motor generator M1 is disconnected from the drive wheels 42f and 42r, as in the PS2 mode and the OD2 mode described above.

  Next, the switching control of the traveling mode during the backward traveling by the vehicle control unit 73 will be described. FIG. 12 is a flowchart showing an example of the procedure for setting the travel mode during reverse travel. In FIG. 12, the state in which the depression of the brake pedal (brake operation) is released is shown as brake OFF. Further, whether or not the occupant has operated the brake is determined based on the amount of depression of the brake pedal detected by the brake pedal sensor 76. In this case, it may be determined that the brake operation is performed when the amount of depression of the brake pedal exceeds zero, and the brake operation is performed when the amount of depression of the brake pedal exceeds a predetermined value other than zero. You may judge.

  As shown in FIG. 12, in step S10, it is determined whether or not the select lever is operated in the R range (reverse range). If it is determined in step S10 that the R range is selected, the process proceeds to step S11, and it is determined whether or not the state of charge SOC of the battery 68 is below a predetermined value A. If it is determined in step S11 that the state of charge SOC is lower than the predetermined value A, that is, if it is determined that the battery 68 is not sufficiently charged, the process proceeds to step S12, and the travel mode is set to the series mode. The As described above, when the amount of power stored in the battery 68 is small, the travel mode is set to the series mode, and the reverse traveling by the motor power of the motor generator M1 is performed while the motor generator M2 is generated by the engine power.

  If it is determined in step S11 that the state of charge SOC is equal to or greater than the predetermined value A, that is, if it is determined that the battery 68 is sufficiently charged, the process proceeds to step S13, and the required driving force is determined to be the predetermined value B. It is determined whether or not this is the case. If it is determined in step S13 that the required driving force is less than the predetermined value B, the process proceeds to step S14, and the traveling mode is set to the EV mode. If it is determined in step S13 that the required driving force is equal to or greater than the predetermined value B, the process proceeds to step S15 to execute the timer T count process, and then proceeds to step S16 to determine whether the brake operation has been released. It is determined whether or not. If it is determined in step S16 that the brake operation is being performed, the process proceeds to step S14, and the traveling mode is set to the EV mode. As described above, when the required driving force is small or the brake operation is performed, the traveling mode is set to the EV mode, and the motor 11 is moved backward by the motor power while the engine 11 and the motor generator M2 are stopped. Driving is carried out.

  On the other hand, if it is determined in step S16 that the brake operation has been released, the process proceeds to step S17, where it is determined whether or not the timer T exceeds a predetermined determination time α. If it is determined in step S17 that the timer T exceeds the determination time α, that is, if the required driving force equal to or greater than the predetermined value B is continued over the determination time α, the process proceeds to step S18 and the timer T The reset process is executed, and the process proceeds to step S12 where the traveling mode is set to the series mode. If it is determined in step S17 that the timer T is equal to or shorter than the determination time α, the process proceeds to step S19, where it is determined whether or not the state of charge SOC falls below a predetermined value A. If it is determined in step S19 that the state of charge SOC is lower than the predetermined value A, the process proceeds to step S12, and the travel mode is set to the series mode. On the other hand, if it is determined in step S19 that the state of charge SOC is equal to or greater than the predetermined value A, the process returns to step S13 again, and various conditions such as required driving force, brake operation, timer T, state of charge SOC, and the like are determined. The As described above, when the state in which the required driving force is large and the brake operation is released continues for the determination time α, the traveling mode is set to the series mode. As a result, since the motor generator M2 can generate electric power, a large amount of electric power can be supplied to the motor generator M1 to increase the output torque, and the hybrid vehicle can be driven backward by a sufficient driving force.

  As described so far, in reverse running, the EV mode is set when the required driving force falls below a predetermined value, and the series mode is set when the required driving force exceeds a predetermined value. Here, FIG. 13 is an explanatory view showing a reverse traveling state of the hybrid vehicle. As shown in FIG. 13, when the amount of depression of the accelerator pedal is small and the required driving force is set to be small, the hybrid vehicle is driven backward by the EV mode, while the amount of depression of the accelerator pedal is large and the required driving force is When is set to be large, the hybrid vehicle travels backward in the series mode. Thus, in reverse running, since either EV mode or series mode is set, it is possible to avoid a running mode in which engine power is divided as in the PS1 mode or PS2 mode, and reverse running It becomes possible to prevent insufficient driving force at the time. Since the rotation direction of the engine 11 is determined in one direction, when the gear ratio of the power split mechanism 12 is set in accordance with the PS1 mode or PS2 mode during forward traveling, the ring gear 23 needs to be reversed. It becomes difficult to ensure a sufficient driving force during reverse running. By avoiding such PS1 mode and PS2 mode, insufficient driving force during reverse running is prevented.

  Further, as shown in the flowchart of FIG. 12, in reverse running, the condition for switching from the EV mode to the series mode is that the required driving force exceeds the predetermined value B over the determination time α. Furthermore, in reverse running, the condition for switching from the EV mode to the series mode is that the brake operation is not performed over the determination time α. Here, FIGS. 14A to 14C are explanatory views showing the setting state of the travel mode in the reverse travel. As shown in FIG. 14A, when the required driving force exceeding the predetermined value B is continued over the determination time α, the traveling mode is switched from the EV mode to the series mode. On the other hand, when the required driving force falls below the predetermined value B within the determination time α as shown in FIG. 14B, or when the brake operation is performed within the determination time α as shown in FIG. 14C. In this case, the traveling mode is maintained in the EV mode.

  As described above, even when the required driving force is increased during reverse traveling, the traveling mode is not immediately switched to the series mode, and the EV mode is maintained until a predetermined switching condition is satisfied. . Here, FIG. 15 is a mode map showing an example of a setting area for each travel mode. As indicated by an arrow a in FIG. 15, even when the vehicle state (required driving force, vehicle speed) during reverse traveling temporarily enters the series mode region from the EV mode region, a predetermined switching condition is satisfied. Until this is done, switching to the series mode is avoided by maintaining the EV mode. That is, the situation where the required driving force decreases at the determination time α and the situation where the brake operation is performed at the determination time α are situations where the vehicle is supposed to stop from reverse travel as indicated by an arrow b in FIG. Furthermore, as shown by an arrow c in FIG. 15, the vehicle is assumed to travel forward after stopping. As described above, in a situation where switching from the backward traveling to the forward traveling is assumed, the switching from the EV mode to the series mode is stopped in preparation for the switching from the backward traveling to the forward traveling.

  For example, if the travel mode is switched from the EV mode to the series mode when temporarily entering the series mode region in the reverse travel, then when switching from the reverse travel to the forward travel, the series mode is changed to the PS1 mode. It is necessary to switch the driving mode. On the other hand, even when temporarily entering the series mode region, if the traveling mode is maintained in the EV mode, the vehicle travels from the EV mode to the PS1 mode when switching from backward traveling to forward traveling thereafter. It is possible to switch modes. Here, when switching from the series mode to the PS1 mode, it is necessary to switch the clutch CL3 from the engaged state to the released state, whereas when switching from the EV mode to the PS1 mode, the clutch CL3 is in the released state. It can be held as it is. That is, when switching from the series mode to the PS1 mode, the switching operation of the clutch CL3 is required, whereas when switching from the EV mode to the PS1 mode, the switching operation of the clutch CL3 is not necessary. In this way, by avoiding unnecessary switching to the series mode in reverse travel, it becomes possible to quickly switch to the PS1 mode by reducing the switching operation of the clutch CL3, and to improve responsiveness when moving from reverse travel to forward travel. It is possible to improve.

  It should be noted that the predetermined value compared with the required driving force when switching the traveling mode (EV mode, series mode) in reverse traveling is a value set using a predetermined control program, map data, or the like. As shown by the characteristic line L1 in FIG. 15, this predetermined value is a value that changes according to the vehicle speed. However, the predetermined value is not limited to this, and a fixed value is adopted as the predetermined value to be compared with the required driving force. May be. Further, a predetermined value compared with the required driving force when switching from the EV mode to the series mode and a predetermined value compared with the required driving force when switching from the series mode to the EV mode may be set separately. Similarly, the predetermined value compared with the required driving force when the traveling mode (EV mode, PS1 mode) is switched in forward traveling is a value set using a predetermined control program, map data, or the like. As shown by the characteristic line L2 in FIG. 15, this predetermined value is a value that changes according to the vehicle speed, but is not limited to this, and a fixed value is adopted as the predetermined value to be compared with the required driving force. May be. Further, a predetermined value compared with the required driving force when switching from the EV mode to the PS1 mode and a predetermined value compared with the required driving force when switching from the PS1 mode to the EV mode may be set separately.

  Next, the traveling state of the hybrid vehicle that starts the forward traveling from the backward traveling will be described again with reference to the drawings. Here, FIG. 16 is an explanatory diagram illustrating a traveling state of a hybrid vehicle that starts traveling forward from backward traveling. As shown in FIG. 16, when the accelerator pedal is depressed during reverse travel in the EV mode and the required driving force is raised to a predetermined value B or more (reference a), the required driving force over a predetermined determination time α. Is determined by the vehicle control unit 73. When the required driving force falls below the predetermined value B within the determination time α, or when the brake pedal is depressed as shown in the figure (reference symbol b, brake ON), switching to the series mode is stopped. Thus, the traveling mode is maintained in the EV mode. Subsequently, when the select lever is operated to the D range (forward range) and the accelerator pedal is depressed after the vehicle stops, the hybrid vehicle starts to travel forward in the EV mode. When the required driving force exceeds a predetermined value, the traveling mode is switched from the EV mode to the PS1 mode, and when the required driving force falls below the predetermined value, the traveling mode is switched from the PS1 mode to the EV mode.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. In the above description, the PS1 mode is cited as the power split mode (third mode), but the present invention is not limited to this, and the PS2 mode may be used as the power split mode (third mode). In the above description, the travel mode includes the series mode, EV mode, PS1 mode, PS2 mode, OD1 mode, OD2 mode, and direct connection mode, but is not limited thereto. For example, three driving modes including a series mode, an EV mode, and a PS1 mode may be set, or three driving modes including a series mode, an EV mode, and a PS2 mode may be set. Moreover, when reducing driving | running | working modes, you may reduce clutch CL2 and clutch CL4 collectively.

  In the EV mode, which is the first mode, the clutch CL1 is released and the clutch CL3 is released. However, the clutch CL3 may be released after the clutch CL1 is released. CL1 may be released. Similarly, in the series mode that is the second mode, the clutch CL1 is released and the clutch CL3 is engaged. However, the clutch CL3 may be engaged after the clutch CL1 is released, or after the clutch CL3 is engaged. The clutch CL1 may be released. Similarly, in the PS1 mode that is the third mode, the clutch CL1 is engaged and the clutch CL3 is released. However, the clutch CL3 may be released after the clutch CL1 is engaged, or after the clutch CL3 is released. The clutch CL1 may be engaged.

  In the above description, one vehicle control unit 73 is caused to function as a travel mode control unit. In the above description, the compound planetary gear type power dividing mechanism 12 is provided. However, the planetary gear train constituting the power dividing mechanism 12 is not limited to the compound planetary gear train and is a single planetary gear train. It may be. For example, in the case shown in the figure, two sun gears 17 and 18 are incorporated in the power split mechanism 12, but the present invention is not limited to this, and the power split mechanism 12 may be configured using one sun gear. In the above description, the drive wheels 42f and 42r are connected to the ring gear 23, and the motor generator M2 is connected to the first sun gear 17. However, the present invention is not limited to this, and the motor generator M2 is connected to the ring gear 23. The driving wheels 42f and 42r may be coupled to the first sun gear 17.

  In the above description, the clutch CL1 is provided between the front wheel output shaft 35 and the driven gear 34. However, the clutch CL1 is not limited to this, and any other device may be used as long as it is between the drive wheels 42f and 42r and the power split mechanism 12. The clutch CL1 may be provided at the position. In the above description, the second sun gear 18 and the ring gear 23 are fastened by using the clutch CL3. However, the present invention is not limited to this, and other rotating elements that constitute the power split mechanism 12 are moved by the clutch CL3. It may be concluded. Further, although the clutches CL1 to CL4 are configured by the synchromesh having the rotation synchronization function, the clutches CL1 to CL4 may be configured by a dog clutch that is a meshing clutch without being limited thereto. Furthermore, the clutches CL1 to CL4 are not limited to meshing clutches, and the clutches CL1 to CL4 may be configured by friction clutches. The illustrated driving device 10 is a driving device for four-wheel driving, but is not limited thereto, and the present invention may be applied to a driving device for driving front wheels or driving rear wheels. .

DESCRIPTION OF SYMBOLS 10 Drive apparatus 11 Engine 12 Power split mechanism 15 Carrier (rotating element)
16 Pinion gear (rotating element)
17 1st sun gear (rotating element)
18 Second sun gear (rotating element)
23 Ring gear (rotating element)
42f, 42r Drive wheel 73 Vehicle control unit (travel mode control unit)
CL1 clutch (first clutch mechanism)
CL3 clutch (second clutch mechanism)
M1 First motor generator M2 Second motor generator Xe Engine power system Xm Motor power system

Claims (6)

A motor power system comprising a first motor generator coupled to drive wheels, and transmitting motor power from the first motor generator to the drive wheels;
An engine power system that includes an engine, a second motor generator, and a power split mechanism coupled to the drive wheels, and transmits engine power from the engine to the drive wheels via the power split mechanism;
A first state is provided between the drive wheel and the power split mechanism, and is switched between a fastening state for connecting the drive wheel and the power split mechanism and a release state for disconnecting the drive wheel and the power split mechanism. A clutch mechanism;
A second clutch mechanism provided in the power split mechanism and switched between a fastening state in which a plurality of rotating elements constituting the power split mechanism are integrally rotated and a released state in which the plurality of rotating elements are individually rotated;
A travel mode control unit that controls the first clutch mechanism and the second clutch mechanism;
The travel mode control unit, as a travel mode, releases the first clutch mechanism and releases the second clutch mechanism, and releases the first clutch mechanism and fastens the second clutch mechanism. A second mode, and a third mode for fastening the first clutch mechanism and releasing the second clutch mechanism,
The travel mode control unit sets one of the first mode and the second mode during reverse travel, and is a hybrid vehicle drive device. In the hybrid vehicle drive device according to claim 1,
The first mode is an EV mode in which motor power is transmitted from the first motor generator to the drive wheels while stopping the engine and the second motor generator.
The second mode is a series mode in which the motor power is transmitted from the first motor generator to the drive wheels while the second motor generator is generated by engine power.
The third mode is a power split mode in which engine power split via the power split mechanism is transmitted to the drive wheels. In the hybrid vehicle drive device according to claim 1 or 2,
The traveling mode control unit sets the first mode when the required driving force during reverse traveling is less than a predetermined value, and sets the second mode when the required driving force during reverse traveling exceeds a predetermined value. A drive device for a hybrid vehicle. The drive device for a hybrid vehicle according to claim 3,
The traveling mode control unit starts from the first mode when the requested driving force exceeding a predetermined value is continued over a determination time under a state in which the first mode is set during backward traveling. A hybrid vehicle drive device characterized by switching to two modes. The drive device for a hybrid vehicle according to claim 4,
The driving mode control unit maintains the setting of the first mode when an occupant's brake operation is performed within the determination time. In the drive device of the hybrid vehicle according to any one of claims 1 to 5,
The traveling mode control unit sets the first mode when the required driving force during forward traveling is less than a predetermined value, and sets the third mode when the required driving force during forward traveling exceeds a predetermined value. A drive device for a hybrid vehicle.

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