JP6638566B2 - Vehicle control device - Google Patents

Description

  The present invention is directed to a differential unit that is connected to an engine via a transmission unit to control an operation state of a first rotating machine to control a differential state, and a differential unit that is connected to drive wheels to be able to transmit power. The present invention relates to a control device for a vehicle including a two-turn machine.

  A transmission unit connected to the input rotary member so that the engine can transmit power, a first rotary element connected to the output rotary member of the transmission unit, and a second rotary element connected to the first rotary machine so as to transmit power; A differential unit including a differential mechanism having a third rotating element coupled to a drive wheel, wherein a differential state of the differential mechanism is controlled by controlling an operation state of the first rotating machine; 2. Description of the Related Art A vehicle including a second rotating machine connected to the driving wheels so as to transmit power is well known. For example, this is the vehicle described in Patent Document 1. According to Patent Document 1, a transmission unit that transmits the power of an engine to a differential unit includes a planetary gear mechanism and two friction engagement devices whose engagement and release are controlled by hydraulic pressure. It is disclosed that the transmission section is switched between high and low by controlling the operation states (engagement and release states) of those friction engagement devices.

International Publication No. WO 2013/114594

  By the way, the vehicle further includes an engagement device for connecting the engine and the first rotating machine in order to improve fuel efficiency. For example, the transmission unit is set to a neutral state (neutral state) and the engagement device is set to the engagement state. By doing so, it is conceivable that the first rotating machine generates electric power by the power of the engine, and the second rotating machine is driven by using the generated electric power to enable series traveling. In the vehicle configured as described above, for example, by setting the transmission portion to a state in which one of the gear positions is formed and setting the engagement device that connects the engine to the first rotating machine to the engagement state, Parallel traveling, in which a two-rotating machine is driven to travel, is also possible. On the other hand, in the vehicle, in addition to the engine running in which the engine is driven by running the engine such as the parallel running, it is also possible to perform the engine stopped running in which the engine is stopped in running. In such an engine stop traveling, for example, the motor is driven by driving the second rotating machine with the engaging devices for connecting the engine and the first rotating machine in the disengaged state and with the engaging devices of the transmission section all in the disengaged state. It is possible to drive the vehicle with any of the engagement devices of the transmission portion in an engaged state (that is, with the transmission portion in a state where any of the gears is formed) so that the engine brake can be quickly applied. It is also possible to do. On the other hand, in switching from engine running to engine stopped running, the operation of the engine is stopped. In particular, when switching from the parallel traveling to the engine stop traveling in which the gear of the transmission unit is formed, when the gear stage of the transmission unit is switched, in addition to stopping the engine, the transmission unit may be shifted. It is necessary to switch the engagement device that connects the engine and the first rotating machine to the released state. In such a case, the switching control from the parallel traveling to the engine stopped traveling becomes complicated, so that the stop of the engine is delayed, and the fuel efficiency may be deteriorated.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide one of the first engagement device and the second engagement device in the transmission unit. One of the engagement devices is released from the engine traveling in which the engagement state is established, the other engagement device is released, and the third engagement device connecting the engine and the first rotating machine is engaged. When the vehicle is switched to the stopped state in which the vehicle is in the state and the other engagement device is in the engaged state and the third engagement device is in the released state, the engine can be stopped quickly, and the fuel consumption can be reduced. It is an object of the present invention to provide a vehicle control device that can be improved.

The gist of the first invention is as follows: (a) a speed change portion connected to an input rotation member so that the engine can transmit power; a first rotation element connected to an output rotation member of the speed change portion; A differential mechanism having a second rotary element connected to the power transmission-capable machine and a third rotary element connected to drive wheels, and controlling the operating state of the first rotary machine to control the differential. A control device for a vehicle comprising: a differential section for controlling a differential state of a mechanism; and a second rotary machine communicably connected to the driving wheels, wherein (b) the vehicle includes: A first engagement device that forms a first gear position of the transmission portion by combination, a second engagement device that forms a second gear position of the transmission portion by engagement, the engine and the first rotation. (C) the first engagement device and the third engagement device. While the engine is running, the engine is driven in an engaged state of any one of the engaging devices, in a disengaged state of the other engaging device, and in an engaged state of the third engaging device. In the disengaged state of the one engagement device, the engagement state of the other engagement device, and the disengaged state of the third engagement device, switching to the engine stop traveling is performed in which the operation of the engine is stopped and the vehicle travels. And a switching determination unit that determines whether there is a fuel efficiency priority request that prioritizes fuel efficiency reduction, and (d) when it is determined to perform switching to the engine stop running, When it is determined that there is a fuel efficiency priority request , after the operation of the engine is stopped, the operating state of each of the first engagement device, the second engagement device, and the third engagement device is determined. while performing the switching, the fuel consumption priority main It is when it is determined not to, after switching the third engaging device to a released state, a running state switching control unit for stopping the operation of said engine is to contain.

According to the first aspect, one of the first engagement device and the second engagement device is in the engaged state, the other is in the released state, and the third engagement device is in the released state. From the engine running in which the engagement devices are engaged, one engagement device is released, the other engagement device is engaged, and the third engagement device is released. If there is a fuel efficiency priority request when switching to the engine stop running, after stopping the operation of the engine, the operating state of each of the first engagement device, the second engagement device, and the third engagement device Is executed, the engine can be stopped immediately when switching from the engine running to the engine stopped running, and the fuel efficiency can be improved. On the other hand, if there is no fuel efficiency priority request, the operation of the engine is stopped after the third engagement device is switched to the released state. With this configuration, the shock (for example, the magnitude of the change (decrease) in the engine torque exerted on the output torque) caused by stopping the operation of the engine is caused by the state where the entire gear ratio of the transmission unit and the differential unit is fixed. Than the engagement state of any one of the first engagement device and the second engagement device, the release state of the other engagement device, and the engagement state of the third engagement device. It is considered that the engagement state of one of the first engagement device and the second engagement device, the release state of the other engagement device, and the release state of the third engagement device are smaller. On the other hand, only when there is a priority request for fuel efficiency, the control for stopping the operation of the engine is executed with priority, so that the ride comfort (shock suppression) according to the driver's request and the improvement in fuel efficiency are both achieved. Can be.

FIG. 1 is a diagram illustrating a schematic configuration of each unit related to traveling of a vehicle to which the present invention is applied, and is a diagram illustrating a main part of a control system for controlling each unit. FIG. 4 is a diagram illustrating an example of a driving force source switching map used for switching control between engine traveling and motor traveling. It is a chart which shows each operation state of each engagement device in each run mode. FIG. 7 is an alignment chart in a single drive EV mode. FIG. 7 is a nomographic chart in a double drive EV mode. FIG. 4 is an alignment chart in a series parallel low mode of an HV traveling mode. FIG. 4 is a nomographic chart in a series parallel high mode of the HV running mode. FIG. 4 is an alignment chart in a series mode of an HV traveling mode. FIG. 4 is an alignment chart in a parallel low mode of the HV traveling mode. FIG. 4 is a collinear chart in a parallel high mode of the HV traveling mode. 5 is a flowchart illustrating a main part of the control operation of the electronic control device, that is, a control operation for improving fuel efficiency by enabling the engine to be stopped promptly when switching from the parallel traveling to the single drive EV emblem combined traveling. FIG. 12 is a time chart when the control operation shown in the flowchart of FIG. 11 is executed, and there is no fuel efficiency priority request when a switch to single drive EV traveling (B1 engagement) occurs, and there is a possibility of an engine restart request. FIG. 9 is a diagram illustrating an example of a case where is high. FIG. 12 is a time chart when the control operation shown in the flowchart of FIG. 11 is executed, showing an example of a case where there is a fuel efficiency priority request when switching to single drive EV traveling (B1 engagement) occurs.

  Preferably, in the control device for a vehicle according to the first aspect, the switching determination unit determines whether there is a high possibility of a request for restarting the engine, and the driving state switching control The unit determines that there is a high possibility of the restart request when stopping the operation of the engine after switching the third engagement device to the disengaged state due to the determination that there is no fuel efficiency priority request. In this case, it is determined that the possibility of the restart request is low while the operation of the engine is stopped after the operation states of the first engagement device and the second engagement device are switched. In this case, after the operation of the engine is stopped, the operation state of each of the first engagement device and the second engagement device is switched. With this configuration, when the operation states of the first engagement device and the second engagement device are switched while the engine is operating, the command of the torque capacity of the engagement device at the time of the switching is performed. Regarding the possibility that the load on the engine fluctuates due to variation in the value and the engine rotational speed fluctuates and a shock occurs, priority is given to either the stop control of the engine or the switching control of the operating state of the engagement device. Is switched according to whether the possibility of the restart request is high or low, so that it is possible to both suppress the shock more and avoid restarting the engine as much as possible. Specifically, since the operation of the engine is stopped after switching the third engagement device to the disengaged state, the shock accompanying the stop of the operation of the engine is originally suppressed. In addition, when the operation states of the first engagement device and the second engagement device are switched after the operation of the engine is stopped, the shock is suppressed and the riding comfort is improved as compared with the case where the switching is performed during the operation of the engine. If the possibility of the restart request is low, the operation of the engine is stopped first. On the other hand, the more the engine stoppage is delayed, the easier it is to avoid a situation in which the engine must be started immediately after the engine stoppage. The switching of the operation state of each of the device and the second engagement device is performed, and the stop of the operation of the engine is delayed. This makes it possible to achieve both riding comfort and avoidance of stopping and starting the engine in a short period of time, depending on whether the possibility of the restart request is high or low.

  Preferably, in the control device for a vehicle according to the first invention, the switching determination unit determines that a charging capacity of a power storage device that exchanges power with each of the first rotating machine and the second rotating machine is a predetermined capacity. It is determined whether or not the possibility of the engine restart request is high based on whether or not the engine restart request is lower. Alternatively, the switching determination unit determines whether the possibility of the engine restart request is high based on whether the absolute value of the speed of decreasing the accelerator opening is lower than a predetermined speed. With this configuration, it is appropriately determined whether the possibility of the engine restart request is high or low.

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

  FIG. 1 is a diagram illustrating a schematic configuration of each unit related to traveling of a vehicle 10 to which the present invention is applied, and a diagram illustrating a main part of a control system for controlling each unit. In FIG. 1, a vehicle 10 is a hybrid vehicle including an engine 12, a first rotating machine MG1, a second rotating machine MG2, a power transmission device 14, and a driving wheel 16, which can be a driving force source for traveling. .

  The engine 12 is a known internal combustion engine that outputs power by burning a predetermined fuel, such as a gasoline engine or a diesel engine. The engine torque Te of the engine 12 is controlled by controlling an operating state such as a throttle opening degree, an intake air amount, a fuel supply amount, an ignition timing, and the like by an electronic control device 80 described later.

  The first rotating machine MG1 and the second rotating machine MG2 are so-called motor generators having a function as an electric motor (motor) for generating drive torque and a function as a generator (generator). The first rotary machine MG1 and the second rotary machine MG2 are connected to a battery unit 20 as a power storage device for transmitting and receiving power via a power control unit 18 having an inverter unit, a smoothing capacitor, and the like. By controlling the power control unit 18 by the control device 80, the MG1 torque Tmg1 and the MG2 torque Tmg2, which are the output torques (powering torque or regenerative torque) of the first rotating machine MG1 and the second rotating machine MG2, respectively, are controlled. You.

  The power transmission device 14 is provided in a power transmission path between the engine 12 and the drive wheels 16, and includes a first rotating machine MG1 and a second rotating machine MG2 in a case 22, which is a non-rotating member attached to the vehicle body. It is housed with. The power transmission device 14 has a first power transmission unit 24, a second power transmission unit 26, a driven gear 30 meshing with a drive gear 28, which is an output rotating member of the first power transmission unit 24, and a driven gear 30 fixedly fixed to the relative rotation. The driven shaft 32, a final gear 34 fixed to the driven shaft 32 so as to be relatively non-rotatable (final gear 34 having a smaller diameter than the driven gear 30), a differential gear 38 meshing with the final gear 34 via a differential ring gear 36, and the like are provided in the case 22. In preparation. In addition, the power transmission device 14 includes an axle 40 and the like connected to a differential gear 38.

  The first power transmission unit 24 is arranged coaxially with an input shaft 42 that is an input rotating member of the first power transmission unit 24, and includes a transmission unit 44 and a differential unit 46. The transmission unit 44 includes a first planetary gear mechanism 48, a clutch C1, and a brake B1. The differential unit 46 includes a second planetary gear mechanism 50 and a clutch CS.

  The first planetary gear mechanism 48 includes a first sun gear S1, a first pinion gear P1, a first carrier CA1 that supports the first pinion gear P1 so as to be able to rotate and revolve, and a first gear that meshes with the first sun gear S1 via the first pinion gear P1. This is a known single-pinion type planetary gear mechanism having a ring gear R1 and functions as a differential mechanism that generates a differential action. The first planetary gear mechanism 48 is an input-side differential mechanism arranged closer to the engine 12 than the second planetary gear mechanism 50 is. The first carrier CA1 is a rotating element (for example, a first rotating element RE1) that is integrally connected to the input shaft 42 and is connected to the engine 12 via the input shaft 42 so that power can be transmitted. Functions as an input rotating member. The first sun gear S1 is a rotating element (for example, a second rotating element RE2) that is selectively connected to the case 22 via the brake B1. The first ring gear R1 is a rotating element (for example, a third rotating element RE3) connected to the input rotating member of the differential section 46 (ie, the second carrier CA2 of the second planetary gear mechanism 50), and the output of the transmission section 44. Functions as a rotating member. Further, the first carrier CA1 and the first sun gear S1 are selectively connected via a clutch C1.

  Each of the clutch C1 and the brake B1 is preferably a wet frictional engagement device, and is a multi-plate hydraulic frictional engagement device, the engagement of which is controlled by a hydraulic actuator. The clutch C <b> 1 and the brake B <b> 1 are controlled by a hydraulic control circuit 52 provided in the vehicle 10 by an electronic control device 80, which will be described later, so that hydraulic pressures supplied from the hydraulic control circuit 52 (for example, C1 hydraulic pressures Pc1 and B1) are provided. An operation state (a state such as engagement or disengagement) is controlled according to the hydraulic pressure Pb1).

  When both the clutch C1 and the brake B1 are released, the differential of the first planetary gear mechanism 48 is allowed. Therefore, in this state, since the reaction torque of the engine torque Te cannot be obtained in the first sun gear S1, the transmission portion 44 is in a neutral state (neutral state) where mechanical power transmission is not possible. In a state where the clutch C1 is engaged and the brake B1 is released, the rotating elements of the first planetary gear mechanism 48 are integrally rotated. Therefore, in this state, the rotation of the engine 12 is transmitted from the first ring gear R1 to the second carrier CA2 at a constant speed. On the other hand, in a state where the clutch C1 is released and the brake B1 is engaged, the rotation of the first sun gear S1 is stopped in the first planetary gear mechanism 48, and the rotation of the first ring gear R1 is changed to the rotation of the first carrier CA1. It is increased more than speed. Therefore, in this state, the rotation of the engine 12 is accelerated and output from the first ring gear R1. As described above, the transmission 44 is a two-stage stepped transmission that can be switched between a low gear in a directly connected state (gear ratio = 1.0) and a high gear in an overdrive state (gear ratio = 0.7). Function as The clutch C1 is a first engagement device that forms a low gear as a first gear of the transmission 44 by engagement, and the brake B1 engages a high gear as a second gear of the transmission 44 by engagement. It is a second engagement device to be formed. Therefore, in a state in which one of the clutch C1 and the brake B1 is engaged, the transmission unit 44 is configured to perform the non-mechanical power transmission in which one of the first and second gears is formed. Neutral state. When the clutch C1 and the brake B1 are both engaged, the rotation of each rotating element of the first planetary gear mechanism 48 is stopped. Therefore, in this state, the rotation of the first ring gear R1, which is the output rotating member of the transmission unit 44, is stopped, and the rotation of the second carrier CA2, which is the input rotating member of the differential unit 46, is stopped.

  The second planetary gear mechanism 50 is configured to mesh with the second sun gear S2 via the second sun gear S2, the second pinion gear P2, the second carrier CA2 that supports the second pinion gear P2 to be able to rotate and revolve, and the second pinion gear P2. It is a known single pinion type planetary gear mechanism having a ring gear R2, and functions as a differential mechanism that generates a differential action. The second planetary gear mechanism 50 is an output-side differential mechanism arranged closer to the driving wheel 16 than the first planetary gear mechanism 48 is. The second carrier CA2 is a rotary element (for example, a first rotary element RE1) as an input element connected to an output rotary member of the transmission unit 44 (that is, the first ring gear R1 of the first planetary gear mechanism 48). It functions as an input rotating member of the unit 46. The second sun gear S2 is integrally connected to a rotor shaft 54 of the first rotating machine MG1, and a rotating element (for example, a second rotating element) as a reaction element to which the first rotating machine MG1 is connected so as to transmit power. RE2). The second ring gear R <b> 2 is integrally connected to the drive gear 28, is a rotating element (for example, a third rotating element RE <b> 3) as an output element connected to the driving wheel 16, and is an output rotating member of the differential unit 46. Function as The second sun gear S2 is selectively connected to the first carrier CA1 via the clutch CS. Therefore, the clutch CS is a third engagement device that selectively connects the engine 12 connected to the first carrier CA1 and the first rotating machine MG1 connected to the second sun gear S2.

  The clutch CS is preferably a wet-type frictional engagement device, and is a multi-plate type hydraulic frictional engagement device, the engagement of which is controlled by a hydraulic actuator. When the hydraulic control circuit 52 is controlled by an electronic control device 80 described later, the clutch CS operates according to a hydraulic pressure (for example, CS hydraulic pressure Pcs) supplied from the hydraulic control circuit 52 (such as engagement or disengagement). Is controlled.

  In a state where the clutch CS is released, the differential of the second planetary gear mechanism 50 is allowed. Therefore, in this state, the second planetary gear mechanism 50 can function as a power distribution mechanism that distributes the power input to the second carrier CA2 to the first rotating machine MG1 and the second ring gear R2. That is, in the differential section 46, in addition to the mechanical power transmission distributed to the second ring gear R2, the first rotary machine MG1 is generated by the power distributed to the first rotary machine MG1, and the generated power is The second rotating machine MG2 is stored or driven by the electric power. Thus, the differential unit 46 controls the power control unit 18 by an electronic control unit 80 described later to control the operating state of the first rotating machine MG1, thereby controlling a gear ratio (speed ratio). It functions as a differential unit (electrical continuously variable transmission). That is, the differential portion 46 includes a second planetary gear mechanism 50 as a differential mechanism connected to the engine 12 so as to transmit power, and a differential rotating machine connected to the second planetary gear mechanism 50 so as to transmit power. And a first rotary machine MG1 serving as a control unit, and the differential state of the second planetary gear mechanism 50 is controlled by controlling the operation state of the first rotary machine MG1. When the clutch CS is engaged, the engine 12 and the first rotating machine MG1 are connected to each other, so that the first rotating machine MG1 generates power by the power of the engine 12, and the generated power is stored. It is possible to drive the second rotating machine MG2 with the electric power.

  In the first power transmission unit 24 thus configured, the power of the engine 12 and the power of the first rotating machine MG1 are transmitted from the drive gear 28 to the driven gear 30. Therefore, the engine 12 and the first rotating machine MG <b> 1 are connected to the driving wheels 16 via the first power transmission unit 24 so that power can be transmitted. In addition, since the transmission unit 44 is overdriven, the increase in the torque of the first rotating machine MG1 is suppressed.

  The second power transmission unit 26 is separate from the input shaft 42 and arranged in parallel with the input shaft 42. The second power transmission unit 26 meshes with the rotor shaft 56 of the second rotating machine MG <b> 2 and the driven gear 30, and the reduction connected to the rotor shaft 56. The gear 58 (a reduction gear 58 having a smaller diameter than the driven gear 30) is provided. Thereby, in the second power transmission unit 26, the power of the second rotary machine MG2 is transmitted to the driven gear 30 without passing through the first power transmission unit 24. Therefore, the second rotary machine MG2 is connected to the drive wheels 16 so as to transmit power without passing through the first power transmission unit 24. That is, the second rotating machine MG2 is a rotating machine that is connected to the axle 40 that is the output rotating member of the power transmission device 14 without power via the first power transmission unit 24 so as to be able to transmit power. In addition to the axle 40, the final gear 34 and the differential ring gear 36 are the same as the output rotary member of the power transmission device 14.

  The power transmission device 14 configured as described above is suitably used for an FF (front engine / front drive) type vehicle. Further, in the power transmission device 14, the power of the engine 12, the power of the first rotary machine MG1, and the power of the second rotary machine MG2 are transmitted to the driven gear 30, from which the final gear 34, the differential gear 38, the axle The power is transmitted to the drive wheels 16 through the wheels 40 and the like. Further, in the power transmission device 14, the engine 12, the first power transmission unit 24, and the first rotary machine MG1 and the second rotary machine MG2 are arranged on different axes, so that the shaft length is reduced. ing. Further, it is possible to increase the reduction ratio of the second rotating machine MG2.

  The vehicle 10 includes an electronic control unit 80 including a control unit that controls each unit related to traveling. The electronic control unit 80 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and operates according to a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 80 executes output control of the engine 12, the first rotating machine MG1, and the second rotating machine MG2, switching control of a driving mode described later, and the like. It is configured separately for control, rotating machine control, hydraulic control, etc.

  The electronic control unit 80 includes various sensors provided in the vehicle 10 (for example, an engine rotation speed sensor 60, an output rotation speed sensor 62, an MG1 rotation speed sensor 64 such as a resolver, an MG2 rotation speed sensor 66 such as a resolver, an accelerator opening). Various signals (for example, output rotation speeds Nout and MG1 that are rotation speeds of the driven gear 30 corresponding to the engine rotation speed Ne and the vehicle speed V) based on detection values obtained by the degree sensor 68, the shift position sensor 70, the comfort switch 72, the battery sensor 74, and the like. Rotation speed Nmg1, MG2 rotation speed Nmg2, accelerator opening θacc, shift lever operating position Psh, ride comfort is prioritized by the comfort switch 72 operated when the driver intends to prioritize ride comfort over fuel economy performance. Comfort switch indicating the selected (requested) status A signal of the Zion CFon, a battery temperature THbat of the battery unit 20, a battery charge / discharge current Ibat, a battery voltage Vbat, and the like are supplied. The electronic control unit 80 sends various command signals (for example, an engine control command signal Se and a rotating machine control command signal) to each device (for example, the engine 12, the power control unit 18, the hydraulic control circuit 52, etc.) provided in the vehicle 10. Sm, hydraulic control command signal Sp, etc.). The electronic control unit 80 calculates the state of charge (charge capacity) SOC of the battery unit 20 based on, for example, the battery charge / discharge current Ibat and the battery voltage Vbat.

  The electronic control unit 80 includes a hybrid control unit, that is, a hybrid control unit 82, and a power transmission switching unit, that is, a power transmission switching unit 84, in order to realize control functions for various controls in the vehicle 10.

  The hybrid controller 82 controls the opening and closing of the electronic throttle valve, controls the fuel injection amount and the injection timing, and outputs an engine control command signal Se for controlling the ignition timing so that the target torque of the engine torque Te is obtained. The output control of the engine 12 is executed. Further, the hybrid control unit 82 outputs a rotating machine control command signal Sm for controlling the operation of the first rotating machine MG1 and the second rotating machine MG2 to the power control unit 18 so that the target torque of the MG1 torque Tmg1 and the MG2 torque Tmg2 is controlled. The output control of the first rotary machine MG1 and the second rotary machine MG2 is executed so as to obtain.

  The hybrid control unit 82 calculates a drive torque (requested drive torque) required at the vehicle speed V at that time from the accelerator opening θacc, and considers a required charging value (required charging power) and the like to achieve low fuel consumption and low exhaust gas amount. The required drive torque is generated from at least one of the engine 12, the first rotating machine MG1, and the second rotating machine MG2 such that the operation is reduced.

  The hybrid control unit 82 selectively establishes a motor traveling mode (EV traveling mode) or a hybrid traveling mode (HV traveling mode) as the traveling mode according to the traveling state. In the EV traveling mode, while the operation of the engine 12 is stopped, a motor traveling (EV traveling) in which at least one of the first rotating machine MG1 and the second rotating machine MG2 is used as a driving power source for traveling. This is a control mode that can be used. The HV running mode is a control mode that enables the engine to run at least using the engine 12 as a driving power source for running (that is, to run by transmitting the power of the engine 12 to the driving wheels 16). Even if the power of the engine 12 is not mechanically transmitted to the drive wheels 16, for example, the power of the engine 12 is converted into electric power by the power generation of the first rotary machine MG1, and the second rotary machine MG2 is driven by the electric power. If the vehicle travels in the HV traveling mode, it is included in the HV traveling mode. In other words, in such a case, the engine torque Te is not mechanically transmitted to the drive wheels 16, but since the power source that drives the second rotary machine MG2 is the engine 12, this traveling (that is, a series traveling described later) is performed. Is also included in the engine running.

  The hybrid control unit 82 has a boundary between the engine running area and the motor running area (single drive area, both drive areas) previously determined experimentally or designed and stored using the vehicle speed V and the required drive torque as variables. By applying the vehicle speed V and the required driving torque to the relationship (driving power source switching map) as shown in FIG. 2 (that is, predetermined), the traveling state can be set to any of the motor traveling region and the engine traveling region. Determine if there is. When it is determined that the vehicle is in the motor travel region, the hybrid control unit 82 establishes the EV travel mode. On the other hand, when it determines that the vehicle is in the engine travel region, the hybrid control unit 82 establishes the HV travel mode. It should be noted that even when the traveling state is in the motor traveling region, the hybrid control unit 82 determines that the power that can be output from the battery unit 20 is limited due to the low battery temperature THbat or the low charging capacity SOC. When the engine 12 needs to be warmed up, the HV running mode is established so that the engine 12 is operated. As shown in FIG. 2, the motor driving region (single driving region, both driving regions) is in a low vehicle speed region of the vehicle speed V or a low torque region of the required driving torque as compared with the engine driving region.

  When the hybrid drive unit 82 establishes the EV drive mode, the hybrid control unit 82 further applies the vehicle speed V and the required drive torque to a drive power source switching map as shown in FIG. It is determined which is located. For example, the hybrid control unit 82 establishes the single-drive EV mode when only the second rotating machine MG2 can cover the required driving torque, and when the required driving torque cannot be covered only by the second rotating machine MG2. Establishes both drive EV modes. When the single drive EV mode is established, the hybrid control unit 82 enables the EV traveling using only the second rotary machine MG2 as the driving power source for traveling, and establishes the dual drive EV mode. In this case, EV traveling using both the first rotating machine MG1 and the second rotating machine MG2 as a driving power source for traveling is enabled. The hybrid control unit 82 sets the operating point of the second rotating machine MG2 represented by the MG2 rotating speed Nmg2 and the MG2 torque Tmg2 to the operating point of the second rotating machine MG2 even when the required driving torque can be covered only by the second rotating machine MG2. If the operating point falls within a predetermined area as an operating point that degrades the efficiency of the motor (in other words, if it is more efficient to use the first rotary machine MG1 and the second rotary machine MG2 together), the two drive EVs The mode is established. When the dual drive EV mode is established, the hybrid control unit 82 requests the first rotary machine MG1 and the second rotary machine MG2 based on the operating efficiency of the first rotary machine MG1 and the second rotary machine MG2. Share drive torque.

  The hybrid control unit 82 establishes, for example, a series-parallel mode when the HV traveling mode is established because the traveling state is in the engine traveling region. When the series-parallel mode is established, the hybrid control unit 82 transmits the engine direct torque to the drive gear 28 and performs the first rotation by receiving the reaction force to the power of the engine 12 by the power generation of the first rotating machine MG1. The second rotating machine MG2 is driven by the electric power generated by the machine MG1 to transmit torque to the drive wheels 16 and enable the engine to run. That is, when the series-parallel mode is established, the hybrid control unit 82 controls the operating state of the first rotary machine MG1 to transmit the power of the engine 12 to the drive wheels 16 and perform the series-parallel traveling. Make it possible. In this series parallel mode, the hybrid control unit 82 controls the engine 12 at an engine operating point (that is, an engine operating point represented by the engine rotation speed Ne and the engine torque Te) in consideration of a known optimal fuel consumption line of the engine 12. Activate. In this series parallel mode, it is also possible to drive the second rotating machine MG2 by adding the power from the battery unit 20 to the power generated by the first rotating machine MG1.

  The hybrid control unit 82 determines whether the power that can be output from the battery unit 20 is limited or the engine 12 needs to be warmed up when the traveling state is in the motor traveling region (single driving region, both driving regions). For example, the HV driving mode is established. The hybrid control unit 82 establishes the series-parallel mode, for example, when the HV traveling mode is established when the traveling state is in both driving regions, and establishes the HV traveling mode when the traveling state is in the single driving region. If so, the series mode is established. When the series mode is established, the hybrid control unit 82 operates the engine 12 to cause the first rotating machine MG1 to generate power, and drives the second rotating machine MG2 with the generated power of the first rotating machine MG1. A series running in which the MG2 torque Tmg2 is transmitted to the drive wheels 16 to run the vehicle is possible. Note that this series mode can be executed even when the power that can be output from the battery unit 20 is not limited, and in such a case, it can be seen that the single drive region is further expanded.

  When the HV running mode is established, the hybrid control unit 82 can also establish the parallel mode. When the parallel mode is established, the hybrid control unit 82 transmits the power of the first rotary machine MG1 and / or the power of the second rotary machine MG2 to the drive wheels 16 in addition to the power of the engine 12 to travel. Parallel running. This parallel mode is useful in a running state where the required driving torque is large or the vehicle speed V is high.

  The power transmission switching unit 84 controls each engagement operation (operation state) of the clutch C1, the brake B1, and the clutch CS based on the traveling mode established by the hybrid control unit 82. The power transmission switching unit 84 engages and / or disengages the clutch C1, the brake B1, and the clutch CS, respectively, so that power can be transmitted for traveling in the traveling mode established by the hybrid control unit 82. A hydraulic control command signal Sp to be output is output to the hydraulic control circuit 52.

  Here, a traveling mode that can be executed in the vehicle 10 will be described with reference to FIGS. 3 and 4 to 10. FIG. 3 is a table showing the operating states of the clutch C1, the brake B1, and the clutch CS in each traveling mode. In the chart of FIG. 3, the circles indicate the engagement of the engagement devices (C1, B1, CS), the blanks indicate the release, and the triangles indicate the engine brakes (engine (Also referred to as). "G" indicates that the rotating machine (MG1, MG2) mainly functions as a generator, and "M" indicates that the rotating machine (MG1, MG2) mainly functions as a motor when driven, and the generator mainly during regeneration. Function. As shown in FIG. 3, the vehicle 10 can selectively realize an EV traveling mode and an HV traveling mode as traveling modes. The EV traveling mode has two modes, a single drive EV mode and a dual drive EV mode. The HV running mode has three modes: a series parallel mode, a parallel mode, and a series mode.

  FIGS. 4 to 10 are collinear charts that can relatively represent the rotational speeds of the three rotating elements RE1, RE2, and RE3 in each of the first planetary gear mechanism 48 and the second planetary gear mechanism 50. In the alignment chart, vertical lines Y1-Y3 representing the rotational speeds of the rotary elements in the first planetary gear mechanism 48 are sequentially connected to the case 22 via the brake B1, and the vertical line Y1 is selectively connected to the case 22 from the left as viewed in the drawing. The vertical line Y2 indicates the rotational speed of the first carrier CA1 which is the first rotary element RE1 connected to the engine 12, and the vertical line Y3 indicates the rotational speed of the first sun gear S1 which is the second rotary element RE2. The rotation speed of the first ring gear R1, which is the third rotation element RE3 connected to the carrier CA2, is shown. The vertical lines Y4-Y6 representing the rotational speeds of the respective rotary elements in the second planetary gear mechanism 50 are the second rotary element RE2 connected to the first rotary machine MG1 in the order from the left as viewed on the page. The rotation speed of the second sun gear S2, the rotation speed of the second carrier CA2 which is the first rotation element RE1 whose vertical line Y5 is connected to the first ring gear R1, and the third rotation speed of the second carrier CA2 whose vertical line Y6 is connected to the drive gear 28. The rotation speed of the second ring gear R2, which is the rotation element RE3, is shown.

  FIG. 4 is an alignment chart in the single drive EV mode. The single drive EV mode is realized in a state where all of the clutch C1, the brake B1, and the clutch CS are released, as shown in FIG. In the single drive EV mode, as shown in FIG. 4, when the clutch C1 and the brake B1 are released, the differential of the first planetary gear mechanism 48 is allowed, and the transmission section 44 is set in the neutral state. When the speed change portion 44 is set to the neutral state, the differential portion 46 is set to the neutral state because the reaction torque of the MG1 torque Tmg1 cannot be obtained by the second carrier CA2 connected to the first ring gear R1. The transmission unit 24 is also in the neutral state. In this state, the hybrid control unit 82 stops the operation of the engine 12 and causes the second rotating machine MG2 to output the MG2 torque Tmg2 for traveling. When the vehicle is moving backward, the second rotating machine MG2 is rotated reversely with respect to the time when the vehicle is moving forward. While the vehicle is running, the second ring gear R2 connected to the drive gear 28 is rotated in conjunction with the rotation of the second rotary machine MG2 (here, the rotation of the drive wheel 16 is also agreed). In the single drive EV mode, the first rotating machine MG1 may be idled with no load. However, in order to reduce drag loss or the like in the first rotating machine MG1, the hybrid control unit 82 sets the MG1 rotation speed Nmg1 to zero. maintain. For example, the hybrid control unit 82 causes the first rotating machine MG1 to function as a generator, and maintains the MG1 rotation speed Nmg1 at zero by feedback control. Alternatively, the hybrid control unit 82 executes control (d-axis lock control) for flowing a current to the first rotating machine MG1 so that the rotation of the first rotating machine MG1 is fixed, and maintains the MG1 rotation speed Nmg1 at zero. I do. Alternatively, even if the MG1 torque Tmg1 is set to zero, the MG1 torque Tmg1 does not need to be added when the MG1 rotation speed Nmg1 can be maintained at zero by the cogging torque of the first rotating machine MG1. In addition, even if the control for maintaining the MG1 rotation speed Nmg1 at zero is performed, the drive torque is not affected because the first power transmission unit 24 is in the neutral state.

  In the single drive EV mode, the first ring gear R1 is rotated by the second carrier CA2, but since the transmission 44 is in the neutral state, the stopped engine 12 is not rotated and stopped at zero rotation. Is done. Therefore, when the regenerative control is performed by the second rotating machine MG2 during traveling in the single drive EV mode, a large regenerative amount can be obtained. When the battery unit 20 is fully charged and regenerative energy cannot be obtained during traveling in the single drive EV mode, it is conceivable to use an engine brake together. When using the engine brake together, as shown in FIG. 3, the brake B1 or the clutch C1 is engaged (refer to the combined use of the single drive EV mode in FIG. 3). When the brake B1 or the clutch C1 is engaged, the engine 12 is brought into the entrained state, and the engine brake is applied. By increasing the MG1 rotational speed Nmg1, the engine rotational speed Ne in the entrained state of the engine 12 can be increased.

  As described above, the engine rotation speed Ne can be increased by engaging the brake B1 or the clutch C1. Therefore, when starting the engine 12 from the EV running mode, it is assumed that the brake B1 or the clutch C1 is in the engaged state. If necessary, the first rotating machine MG1 raises the engine rotation speed Ne to ignite. At this time, the second rotating machine MG2 additionally outputs a reaction force canceling torque. When the engine 12 is started when the vehicle is stopped, the engine rotation speed Ne may be increased by increasing the rotation of the second carrier CA2 by the first rotating machine MG1 with the brake B1 or the clutch C1 engaged. Alternatively, the engine rotation speed Ne may be increased by engaging the brake B1 or the clutch C1 after raising the rotation of the second carrier CA2 by the first rotating machine MG1.

  FIG. 5 is a collinear chart in the both-drive EV mode. The two-drive EV mode (“Ne = 0”) is realized in a state where the clutch C1 and the brake B1 are engaged and the clutch CS is released, as shown in FIG. In the two-drive EV mode, as shown in FIG. 5, by engaging the clutch C1 and the brake B1, the differential of the first planetary gear mechanism 48 is regulated, and the rotation of the first sun gear S1 is stopped. . Therefore, the first planetary gear mechanism 48 stops rotation of any rotating elements. Thus, the engine 12 is stopped at zero rotation, and the rotation of the second carrier CA2 connected to the first ring gear R1 is also stopped. When the rotation of the second carrier CA2 is stopped, the reaction torque of the MG1 torque Tmg1 can be obtained at the second carrier CA2. Therefore, the MG1 torque Tmg1 is mechanically output from the second ring gear R2 and transmitted to the drive wheels 16. be able to. The hybrid control unit 82 stops the operation of the engine 12, and outputs the MG1 torque Tmg1 and the MG2 torque Tmg2 for traveling from the first rotating machine MG1 and the second rotating machine MG2, respectively. In the two-drive EV mode, it is also possible to reversely drive both the first rotating machine MG1 and the second rotating machine MG2 with respect to the forward traveling, and to travel backward.

  FIG. 6 is an alignment chart in a series parallel mode (hereinafter, referred to as a series parallel low mode) in a low state of the HV traveling mode. The series parallel low mode is realized in a state in which the clutch C1 is engaged and a state in which the brake B1 and the clutch CS are released, as shown in FIG. In the series parallel low mode, as shown in FIG. 6, by engaging the clutch C1, the differential of the first planetary gear mechanism 48 is regulated, and the rotating elements of the first planetary gear mechanism 48 are integrally rotated. . Therefore, the rotation of the engine 12 is transmitted from the first ring gear R1 to the second carrier CA2 at a constant speed.

  FIG. 7 is an alignment chart in a series-parallel mode (hereinafter, referred to as a series-parallel high mode) in a high state of the HV traveling mode. The series parallel high mode is realized with the brake B1 engaged and the clutch C1 and the clutch CS released, as shown in FIG. In the series parallel high mode, as shown in FIG. 7, the rotation of the first sun gear S1 is stopped by engaging the brake B1. Therefore, the rotation of the engine 12 is accelerated and transmitted from the first ring gear R1 to the second carrier CA2.

  In the series parallel mode, the transmission portion 44 is set to the non-neutral state by engaging the clutch C1 or the brake B1, and the first rotating machine MG1 receives a reaction force to the power of the engine 12 transmitted to the second carrier CA2. Thus, a part of the engine torque Te (the engine direct torque) can be mechanically output from the second ring gear R2 and transmitted to the drive wheels 16. The power transmission switching unit 84 switches the transmission unit 44 to the low gear by engaging the clutch C1, and switches the transmission unit 44 to the high gear by engaging the brake B1. The hybrid control unit 82 operates (operates) the engine 12, outputs the MG1 torque Tmg1, which is a reaction torque to the engine torque Te, by the power generation of the first rotating machine MG1, and outputs the MG1 torque Tmg1 by the power generated by the first rotating machine MG1. The second rotary machine MG2 outputs MG2 torque Tmg2. In the series parallel mode, it is also possible to reversely rotate the second rotating machine MG2 with respect to the time of forward traveling and travel backward.

  The hybrid control unit 82 establishes the series parallel high mode when the vehicle speed V is equal to or higher than the predetermined threshold, and sets the series parallel low mode when the vehicle speed V is lower than the predetermined threshold. It is established. Here, the MG1 rotation speed Nmg1 is set to zero, and the power of the engine 12 passes through an electric path (an electric power transmission path that is an electric path related to power transfer between the first rotating machine MG1 and the second rotating machine MG2). At the so-called mechanical point where all the power is mechanically transmitted to the drive gear 28, the theoretical value (theoretical transmission efficiency) of the power transmission efficiency (output power / input power) of the differential section 46 is the largest. It becomes "1". This mechanical point is such that the MG1 rotational speed Nmg1 is zero (ie, the rotational speed of the second sun gear S2 is zero) in the differential portion 46 (see the vertical lines Y4-Y6) in the alignment charts of FIGS. State). In the series parallel mode, the transmission section 44 is switched between a high state (high gear) and a low state (low gear) to reduce the number of mechanical points to two. By having the series parallel mode in the high state, the mechanical points are shifted to the high vehicle speed side. And fuel economy at high speed is improved.

  In the first power transmission unit 24, the transmission unit 44 and the differential unit 46 are connected in series. If the speed of the transmission unit 44 is changed, the gear ratio of the first power transmission unit 24 can also be changed. Therefore, the hybrid control unit 82 adjusts the differential according to the shift of the transmission unit 44 by the power transmission switching unit 84 so that the change in the gear ratio of the first power transmission unit 24 is suppressed, for example, when the transmission unit 44 shifts. The shift of the section 46 is executed. For example, when the transmission unit 44 is upshifted from the low gear to the high gear, the hybrid control unit 82 simultaneously downshifts the differential unit 46. Thus, the first power transmission unit 24 functions as a so-called electric continuously variable transmission. Also, the first power transmission unit 24 in which the transmission unit 44 and the differential unit 46 are connected in series has a wide gear ratio width, so that the gear ratio in the power transmission path from the differential unit 46 to the drive wheels 16 is reduced. Can be relatively large.

  In the series parallel high mode, the rotation speed of the second carrier CA2 is increased with respect to the same engine rotation speed Ne as in the series parallel low mode. Therefore, in the engine running in the series parallel mode, the first rotating machine MG1 is negative at a high vehicle speed. The power running state of the rotating and negative torque and the power circulating state in which electric power is supplied to the first rotating machine MG1 are suppressed.

  FIG. 8 is an alignment chart in the HV running mode in the series mode. The series mode is realized in a state where both the clutch C1 and the brake B1 are released and a state where the clutch CS is engaged, as shown in FIG. In the series mode, as shown in FIG. 8, when the clutch C1 and the brake B1 are released, the differential of the first planetary gear mechanism 48 is allowed, and the transmission unit 44 is set in the neutral state. Therefore, the differential unit 46 is in the neutral state, and the first power transmission unit 24 is also in the neutral state. In addition, in the series mode, when the clutch CS is engaged, the engine 12 and the first rotating machine MG1 are connected. Therefore, by operating the engine 12, the first rotating machine MG1 is rotationally driven to generate power. At this time, since the first power transmission unit 24 is in the neutral state, the engine torque Te is not mechanically transmitted to the drive wheels 16. The hybrid control unit 92 operates the engine 12, causes the first rotating machine MG1 to generate power by the power of the engine 12, and drives the second rotating machine MG2 by the generated power of the first rotating machine MG1 to generate a signal from the second rotating machine MG2. The running MG2 torque Tmg2 is output. In the series mode, it is also possible to reversely rotate the second rotating machine MG2 with respect to the time of forward traveling to travel backward. During traveling of the vehicle, the second ring gear R2 connected to the drive gear 28 is rotated in conjunction with the rotation of the drive wheel 16. Further, the second sun gear S2 is rotated in conjunction with the engine rotation speed Ne. In the differential section 46, the rotation of the second carrier CA2 is determined by the rotation speed of the second ring gear R2 and the rotation speed of the second sun gear S2 thus rotated.

  FIG. 9 is an alignment chart in a parallel mode (hereinafter, referred to as a parallel low mode) in a low state of the HV traveling mode. The parallel low mode is realized in a state in which the clutch C1 and the clutch CS are engaged and a state in which the brake B1 is released, as shown in FIG. In the parallel low mode, as shown in FIG. 9, when the clutch C1 is engaged, the differential of the first planetary gear mechanism 48 is regulated, and the rotating elements of the first planetary gear mechanism 48 are integrally rotated. Therefore, the rotation of the engine 12 is transmitted from the first ring gear R1 to the second carrier CA2 at a constant speed. In addition, in the parallel low mode, the engine 12 and the first rotating machine MG1 are connected by engaging the clutch CS.

  FIG. 10 is an alignment chart in a parallel mode (hereinafter, referred to as a parallel high mode) in a high state of the HV traveling mode. The parallel high mode is realized in a state where the brake B1 and the clutch CS are engaged and a state where the clutch C1 is released, as shown in FIG. In the parallel high mode, the rotation of the first sun gear S1 is stopped by engaging the brake B1, as shown in FIG. Therefore, the rotation of the engine 12 is accelerated and transmitted from the first ring gear R1 to the second carrier CA2. In addition, in the parallel high mode, the engine 12 and the first rotating machine MG1 are connected by engaging the clutch CS.

  In the parallel mode, the gear ratio of the transmission unit 44 is fixed by engaging the clutch C1 or the brake B1 in addition to connecting the engine 12 and the first rotary machine MG1 by engaging the clutch CS. The gear ratio of one power transmission unit 24 (that is, the overall gear ratio of the transmission unit 44 and the differential unit 46) is fixed (hereinafter, the parallel mode may be referred to as the parallel stepped mode). In the parallel traveling, a stepped traveling state is set in which the engine speed Ne is uniquely determined with respect to the vehicle speed V (output rotational speed Nout) (hereinafter, parallel traveling may be referred to as parallel stepped traveling). In the parallel mode, it is possible to mechanically transmit the power of any of the engine 12, the first rotating machine MG1, and the second rotating machine MG2 to the drive wheels 16. For example, at the time of single drive in the parallel mode, the vehicle travels by transmitting the power of the second rotating machine MG2 to the drive wheels 16 in addition to the power of the engine 12. At the time of both driving in the parallel mode, the vehicle travels by transmitting the power of the first rotary machine MG1 and the power of the second rotary machine MG2 to the drive wheels 16 in addition to the power of the engine 12. The hybrid control unit 82 operates the engine 12 and causes the first rotating machine MG1 to output the MG1 torque Tmg1 and the second rotating machine MG2 to output the MG2 torque Tmg2. In the parallel mode, the hybrid control unit 82 outputs a command to the power transmission switching unit 84 so that the transmission unit 44 is in the non-neutral state and the clutch CS is in the engaged state, so that the engine 12 is driven to travel. Execute the run. The power transmission switching unit 84 brings the transmission unit 44 into a non-neutral state by engaging the clutch C1 or the brake B1.

  The operating state of each engagement device (C1, B1, CS) in the parallel mode is the same as in the dual drive EV mode (“Ne free”) shown in FIG. In other words, the alignment charts of FIGS. 9 and 10 are alignment charts of the two-drive EV mode (“Ne-free”) when the operation of the engine 12 is stopped. In the both-drive EV mode (“Ne-free”), the power of the first rotating machine MG1 and the power of the second rotating machine MG2 are transmitted to the drive wheels 16 as in the both-drive EV mode (“Ne = 0”). It is possible to travel. However, in the dual drive EV mode (“Ne free”), the engine rotation speed Ne cannot be set to zero because the engine rotation speed Ne is uniquely determined according to the vehicle speed V during traveling. This is different from the EV mode (“Ne = 0”).

  In the power transmission device 14, a mechanical oil pump (see FIG. 8) for switching the operating states of the clutch C1, the brake B1, and the clutch CS, and supplying hydraulic oil (oil) used for lubricating each part and cooling each part. Is connected to the second carrier CA2, and is driven by the rotation of the second carrier CA2. Therefore, during the series running in the HV running mode, oil necessary for lubrication and the like can be supplied from the oil pump. When the rotation of the second carrier CA2 is stopped as in the case of the two-drive EV mode, oil is supplied by an electric oil pump (not shown).

  By the way, there is a case where the mode is switched from the parallel mode to the single drive EV mode combined with emblem (hereinafter, referred to as single drive EV combined use mode) due to a decrease in the required drive torque during the parallel traveling. In this case, in addition to stopping the operation of the engine 12, it is necessary to switch the operating state of the clutch CS from the engaged state to the released state. Further, when the gear position of the transmission unit 44 in the parallel mode is different from the gear position of the transmission unit 44 in the single drive EV emblem combination mode, when switching from the parallel mode to the single drive EV emblem combination mode. Further, it is necessary to switch the operation state of each of the clutch C1 and the brake B1 (that is, to shift the transmission unit 44). Then, the control when switching from the parallel mode to the single drive EV emblem combined mode becomes complicated, so that the stop of the engine 12 is delayed, and there is a possibility that the fuel efficiency is deteriorated (that is, the fuel efficiency performance is reduced).

  Therefore, the electronic control unit 80 operates the engine 12 in the engaged state of one of the clutches C1 and the brake B1, the released state of the other engaging apparatus, and the engaged state of the clutch CS. An engine stop running in which the operation of the engine 12 is stopped in a disengaged state of the one engagement device, an engaged state of the other engagement device, and a disengaged state of the clutch CS from the parallel traveling as the traveling engine traveling. When switching to traveling in the single-drive EV emblem combined mode (hereinafter also referred to as single-drive EV emblem combined traveling), the operation of the engine 12 is stopped, and then the clutch C1, the brake B1, and the clutch CS are switched off. The switching of each operation state is executed.

  The electronic control unit 80 includes a switching determination unit, that is, a switching determination unit 86, and a traveling state switching control unit in order to realize control when switching from the parallel traveling to the single drive EV emblem combined traveling accompanied by the shift of the transmission unit 44. That is, the driving state switching control unit 88 is further provided.

  The switch determination unit 86 determines whether or not to switch to the single drive EV emblem combined travel accompanied by the shift of the transmission unit 44 during the parallel travel. Specifically, the switching determination unit 86 determines whether or not the vehicle is traveling in parallel. If it is determined that the vehicle is traveling in parallel, the switching determination unit 86 switches to the single-drive EV emblem-combined traveling accompanied by the speed change of the transmission unit 44. It is determined whether or not the switching should be executed (ie, whether or not the switching to the single drive EV emblem combined traveling accompanied by the shifting of the transmission unit 44 has occurred). In the single-drive EV emblem-combined traveling involving the shifting of the transmission unit 44, when the parallel traveling is traveling in the parallel low mode (hereinafter, also referred to as parallel low traveling), the brake B1 is engaged. In this case, the vehicle travels in the single-drive EV emblem combination mode (hereinafter, also referred to as single-drive EV (B1 engagement) mode) (hereinafter, also referred to as single-drive EV travel (B1 engagement)). In the single-drive EV emblem-combined traveling that involves shifting of the transmission unit 44, when the parallel traveling is traveling in the parallel high mode (hereinafter, also referred to as parallel high traveling), the clutch C1 is engaged. This is traveling in the single-drive EV emblem combination mode (hereinafter, also referred to as single-drive EV (C1 engagement) mode) (hereinafter, also referred to as single-drive EV traveling (C1 engagement)).

  The traveling state switching control unit 88 switches to the single drive EV emblem combined with traveling with the shift of the transmission unit 44 during the parallel traveling by the switching determination unit 86 (that is, the single driving EV emblem combined with the shift of the transmission unit 44). When it is determined that the driving has been switched, the command to stop the operation of the engine 12 is output to the hybrid control unit 82, and after the operation of the engine 12 is stopped, the clutch C1, the brake B1, and the A command to switch the operating state of each clutch CS is output to power transmission switching section 84. In such switching control of the running state, the state in which the operation of the engine 12 is only stopped is still the state of engagement of one of the clutches C1 and B1 and the release of the other. In this state, the clutch CS is in the engaged state, and the entire gear ratio of the transmission unit 44 and the differential unit 46 is fixed. Shock caused by the shift of the transmission unit 44 is easily suppressed (absorbed) by the differential unit 46 that has been brought into the differential state by releasing the clutch CS. Is considered to be smaller in the released state. Therefore, after stopping the operation of the engine 12, the traveling state switching control unit 88 first executes the switching to the disengaged state of the clutch CS, and then switches the operating state of each of the clutch C1 and the brake B1. It is preferred to do so.

  Stopping the operation of the engine 12 first when switching from parallel traveling to single-drive EV emblem combined travel involving shifting of the transmission unit 44 suppresses fuel consumption (that is, improves fuel efficiency). The shock (for example, the magnitude of the change (decrease) in the engine torque Te exerted on the output torque) caused by stopping the operation of the engine 12 is larger than the state in which the entire gear ratio of the transmission unit 44 and the differential unit 46 is fixed. It is considered that the clutch CS becomes smaller when the clutch CS is in the released state. Therefore, it can be said that the control for first stopping the operation of the engine 12 is a control that prioritizes the improvement of fuel efficiency over the suppression of shock (ride comfort). On the other hand, when the driver wants to prioritize the riding comfort over the fuel efficiency, it is not preferable to perform the control that prioritizes the improvement of the fuel efficiency. Therefore, when the driver desires to give priority to ride comfort when switching from the parallel traveling to the single drive EV emblem combined with the shifting of the transmission unit 44, the clutch CS is released before the operation of the engine 12 is stopped. Switching to is preferred.

  Specifically, the switching determination unit 86 determines whether there is a fuel efficiency priority request that prioritizes fuel efficiency reduction. The switching determination unit 86 determines whether there is a fuel efficiency priority request (or whether the fuel efficiency priority request is small) based on whether the comfort switch ON CFon signal accompanying the operation of the comfort switch 72 is output. judge. That is, the switching determination unit 86 determines that there is no fuel efficiency priority request when the signal of the comfort switch on CFon is output, whereas the switching determination unit 86 determines that the fuel efficiency priority request is not output when the signal of the comfort switch on CFon is not output. It is determined that there is.

  When switching from the parallel traveling to the single-drive EV emblem combined traveling accompanied by the shift of the transmission 44, the traveling state switching control unit 88 determines whether or not the switching determination unit 86 determines that there is a fuel efficiency priority request. After the operation is stopped, the operation state of each of the clutch C1, the brake B1, and the clutch CS is switched. On the other hand, when the traveling state switching control unit 88 switches from the parallel traveling to the single drive EV emblem combined traveling accompanied by the shift of the transmission unit 44, if the switching determination unit 86 determines that there is no fuel consumption priority request, After switching the clutch CS to the released state, the operation of the engine 12 is stopped. Thus, only when there is a fuel efficiency priority request, the control for stopping the operation of the engine 12 is executed with priority, so that it is possible to achieve both riding comfort (shock suppression) and fuel efficiency improvement in accordance with the driver's request. it can.

  In the embodiment in which the operation of the engine 12 is stopped after the clutch CS is switched to the disengaged state, the operation of the engine 12 is stopped before the shift of the transmission unit 44, and This is also an embodiment to be executed later. When the shift of the transmission unit 44 is executed in a state where the engine 12 is operated, the load on the engine 12 is reduced due to the fact that the actual values of the respective torque capacities of the clutch C1 and the brake B1 vary with the command value during the shift. There is a possibility that the engine speed Ne fluctuates due to fluctuation and a shock occurs. Since the operation of the engine 12 is stopped after the clutch CS is switched to the disengaged state, the shock accompanying the stop of the operation of the engine 12 is the first to occur in a state where the overall gear ratio of the transmission unit 44 and the differential unit 46 is fixed. As compared with the case where the operation of the engine 12 is stopped in the first place, the operation is originally suppressed. In addition, it is considered that when the shift of the transmission unit 44 is performed after the operation of the engine 12 is stopped, the shock is suppressed and the riding comfort is more easily improved than when the shift is performed during the operation of the engine 12. On the other hand, the later the operation stop of the engine 12 is delayed, the easier it is to avoid the situation where the engine 12 must be started immediately after the stop of the engine 12. Therefore, the electronic control unit 80 switches between giving priority to the operation stop control of the engine 12 and the shift control of the transmission unit 44 depending on whether the possibility of the restart request to the engine 12 is high or low. That is, the electronic control unit 80 stops the operation of the engine 12 first when the possibility of the request for restarting the engine 12 is low when the possibility of the request for restarting the engine 12 is high. First, the shift of the transmission unit 44 is executed, and the stop of the operation of the engine 12 is delayed. This makes it possible to both suppress the shock more and avoid restarting the engine 12 as much as possible.

  More specifically, the switching determination unit 86 determines whether there is a high possibility of a request to restart the engine 12. For example, the switching determination unit 86 determines whether the possibility of a request for restarting the engine 12 is high based on whether the charge capacity SOC of the battery unit 20 is lower than a predetermined capacity. It is considered that the lower the charging capacity SOC of the battery unit 20 is, the higher the demand for the first rotating machine MG1 to generate power by the power of the engine 12 to charge the battery unit 20 is. Therefore, when the charging capacity SOC of the battery unit 20 is lower than the predetermined capacity, it is determined that there is a high possibility that the request for restarting the engine 12 is made. The predetermined capacity is, for example, a predetermined determination threshold value for determining that the charging capacity SOC is low enough to require charging of the battery unit 20. Alternatively, the switching determination unit 86 has a high possibility of a request to restart the engine 12 based on whether or not the absolute value of the accelerator pedal return speed (that is, the speed of decreasing the accelerator opening θacc) is lower than a predetermined speed. It is determined whether or not. It is considered that the lower the absolute value of the decreasing speed of the accelerator opening θacc, the higher the possibility that the deceleration request for the vehicle 12 is switched to the acceleration request. Therefore, when the absolute value of the decreasing speed of the accelerator opening θacc is lower than the predetermined speed, it is determined that there is a high possibility that the restart request of the engine 12 is required. The predetermined speed is, for example, a predetermined determination threshold value for determining that the absolute value of the decreasing speed of the accelerator opening θacc is low enough that the deceleration request may be switched to the acceleration request. In this way, it is appropriately determined whether the possibility of the request for restarting the engine 12 is high or low.

  The running state switching control unit 88 uses the switching determination unit 86 to stop the operation of the engine 12 when the switching determination unit 86 determines that there is no fuel efficiency priority request and switches the clutch CS to the released state. When it is determined that the possibility of the restart request is high, the operation of the engine 12 is stopped after the switching of the operation state of each of the clutch C1 and the brake B1 (that is, the shift of the transmission unit 44) is executed. On the other hand, when the switching determination unit 86 determines that the possibility of the request for restarting the engine 12 is low, the traveling state switching control unit 88 stops the operation of the engine 12 and then shifts the speed of the transmission unit 44. Execute This makes it possible to achieve both riding comfort and avoidance of stopping and starting the engine 12 in a short period of time, depending on whether the possibility of the request for restarting the engine 12 is high or low.

  FIG. 11 illustrates a main part of the control operation of the electronic control unit 80, that is, a control operation for improving the fuel efficiency by enabling the engine 12 to be stopped promptly when switching from the parallel traveling to the single drive EV emblem combined traveling. It is a flowchart, for example, is repeatedly performed during running. In FIG. 11, the control operation of this embodiment will be described by exemplifying a parallel low traveling as the parallel traveling. 12 and 13 are diagrams each showing an example of a time chart when the control operation shown in the flowchart of FIG. 11 is executed. FIG. 12 is a diagram illustrating an example of a case where there is no fuel efficiency priority request when switching to single drive EV traveling (B1 engagement) occurs and there is a high possibility of a request for restarting the engine 12. FIG. 13 is a diagram illustrating an example of a case where there is a fuel efficiency priority request when a switch to single drive EV traveling (B1 engagement) occurs.

  In FIG. 11, first, in a step (hereinafter, step is omitted) S10 corresponding to the function of the switching determination unit 86, it is determined whether or not the vehicle is traveling in the parallel stepped mode (that is, during the parallel stepped traveling). Is done. Here, for example, it is determined whether or not the vehicle is traveling in parallel low. If the determination in S10 is negative, this routine ends. If the determination in S10 is affirmative, in S20 corresponding to the function of the switching determination unit 86, switching to traveling in the single drive EV (B1 engagement) mode (ie, single drive EV traveling (B1 engagement)) is performed. It is determined whether or not to execute (that is, whether or not switching to single-drive EV traveling (B1 engagement) has occurred). If the determination in S20 is negative, this routine is ended. When the determination in S20 is affirmative, in S30 corresponding to the function of the switching determination unit 86, it is determined whether or not the signal of the comfort switch on CFon associated with the operation of the comfort switch 72 is output (that is, fuel efficiency priority). It is determined whether there is a request). If the determination in S30 is affirmative, in S40 corresponding to the function of the traveling state switching control unit 88, the clutch CS is first switched to the released state. Next, in S50 corresponding to the function of the switching determination unit 86, it is determined whether there is a high possibility of a request to restart the engine 12. If the determination in S50 is affirmative, in S60 corresponding to the function of the traveling state switching control unit 88, the operating states of the clutch C1 and the brake B1 are switched (that is, the brake B1 is engaged while the clutch C1 is released). The shift of the transmission unit 44 is performed, and finally, the operation of the engine 12 is stopped (see FIG. 12). Since the engine 12 is self-sustaining during this shift, the shock (shift shock) is reduced as compared with the shock (engine stop shock) caused by stopping the engine 12 first in S80 described later. On the other hand, if the determination in S50 is negative, in S70 corresponding to the function of the traveling state switching control unit 88, after the operation of the engine 12 is stopped, the operating states of the clutch C1 and the brake B1 are switched. Then, the speed change of the speed change section 44 is executed. Since the engine 12 is stopped at the time of this shift, the shock (shift shock) is smaller than the shock in S80 described later and the shock in S60. On the other hand, if the determination in S30 is negative, in S80 corresponding to the function of the traveling state switching control unit 88, the operation of the engine 12 is stopped first. Therefore, fuel consumption is suppressed. Thereafter, the clutch CS is switched to the disengaged state, and the operating states of the clutch C1 and the brake B1 are switched, and the shift of the transmission unit 44 is executed (see FIG. 13).

  FIG. 12 shows a case where switching to single drive EV traveling (B1 engagement) occurs during parallel low traveling (that is, a case where switching from parallel low mode to single driving EV (B1 engagement) mode occurs). Thus, the case where the signal of the comfort switch on CFon accompanying the operation of the comfort switch 72 is output (that is, the case where there is a request to give priority to the riding comfort) is shown. Therefore, in FIG. 12, the clutch CS is released first. Specifically, since the accelerator opening θacc has decreased during the parallel low traveling, the engine torque Te is reduced (see the time point t1 to the time point t3). If it is determined during this time that the accelerator is returned (i.e., it is determined that the mode is switched to the single drive EV traveling (B1 engagement)) (see time t2), the clutch CS is released first (time t3-time t4). reference). In this embodiment, since there is a high possibility of a request for restarting the engine 12, after the clutch CS is released, the clutch C1 is released (refer to time t4 to time t5) before the operation of the engine 12 is stopped. ), The brake B1 is engaged (see time point t5-time point t6), and the shift of the transmission unit 44 is executed. After the shift is completed, the ignition of the engine 12 is stopped (see time t7), and the operation of the engine 12 is stopped. Thereby, the mode is switched to the single drive EV (B1 engagement) mode.

  FIG. 13 shows a case where switching to single drive EV traveling (B1 engagement) occurs during parallel low traveling, and a signal of comfort switch-on CFon is not output (that is, a case where there is a fuel efficiency priority request). Is shown. Therefore, in FIG. 13, the operation of the engine 12 is stopped first. Specifically, since the accelerator opening θacc has decreased during the parallel low traveling, the engine torque Te is reduced (see the time point t1 to the time point t3). During this period, if it is determined that the accelerator is to be returned (that is, if the switching to the single drive EV traveling (B1 engagement) is determined) (see time t2), the ignition of the engine 12 is stopped first (see time t3). ), The operation of the engine 12 is stopped. Thereafter, the clutch CS is disengaged (see time point t3-time point t4). After the clutch CS is released, the clutch B1 is engaged (see time t5-time t6) while the clutch C1 is released (time t4-time t6), and the speed change of the transmission 44 is performed. Thereby, the mode is switched to the single drive EV (B1 engagement) mode.

  As described above, according to this embodiment, one of the clutch C1 and the brake B1 is engaged, the other is disengaged, and the clutch CS is engaged. From the engine running (parallel running) in the state, the engine stop running (simple running) in which one engaging device is in the released state, the other engaging device is in the engaged state, and the clutch CS is in the released state. At the time of switching to the driving EV emblem, the operation of the engine 12 is stopped, and then the operating states of the clutch C1, the brake B1, and the clutch CS are switched. When switching to combined driving, the engine 12 can be stopped immediately, and fuel efficiency can be improved.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is applicable to other aspects.

  For example, in the flowchart of FIG. 11 in the above-described embodiment, the embodiment of the embodiment has been described by exemplifying the parallel low traveling as the parallel traveling. As described above, this parallel traveling includes, for example, parallel high traveling. Therefore, S10, S20, S60-S80, and the like in the flowchart of FIG. 11 may be appropriately changed according to which parallel traveling is being performed. For example, when it is determined in S10 of FIG. 11 whether or not the vehicle is running in the parallel high mode, in S20 of FIG. 11, the vehicle travels in the single drive EV (C1 engagement) mode (that is, the single drive EV travel (C1 engagement). )) Is determined (ie, whether switching to single-drive EV traveling (C1 engagement) has occurred) or not. In S60-S80 of FIG. Is disengaged and the clutch C1 is engaged, whereby the speed change of the transmission unit 44 is performed. Further, in the flowchart of FIG. 11, if the determination in S20 is affirmative, S80 may be executed. In this case, S30 to S70 are not provided. As described above, each step of the flowchart in FIG. 11 can be appropriately changed.

  In the above-described embodiment, the vehicle 10 is a gear train having a connection relationship in which the second rotating machine MG2 is disposed on a different axis from the axis of the first power transmission unit 24. A gear train or the like having a connection relationship in which the second rotating machine MG2 is disposed on the same axis as the axis of the first power transmission unit 24 may be used. In the first place, the present invention can be applied to a vehicle including the engine 12, the transmission unit 44, the differential unit 46, and the second rotary machine MG2 that is connected to the drive wheels 16 so as to be able to transmit power. . Although the present invention has been described using the power transmission device 14 suitably used for the FF type vehicle 10, the present invention is also applicable to a power transmission device used for other types of vehicles such as the RR type. Can be.

  It should be noted that the above is merely an embodiment, and that the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art.

10: Vehicle 12: Engine 16: Drive wheel 44: Transmission section CA1: First carrier (input rotary member of transmission section)
R1: 1st ring gear (output rotating member of transmission section)
46: Differential part 50: Second planetary gear mechanism (differential mechanism)
CA2: second carrier (first rotating element of differential mechanism)
S2: Second sun gear (second rotating element of the differential mechanism)
R2: second ring gear (third rotating element of differential mechanism)
80: Electronic control unit (control unit)
86: switching determination unit 88: traveling state switching control unit C1: clutch (first engagement device)
B1: Brake (second engagement device)
CS: clutch (third engagement device)
MG1: first rotating machine MG2: second rotating machine

Claims (1)

A transmission unit connected to the input rotary member so that the engine can transmit power, a first rotary element connected to the output rotary member of the transmission unit, and a second rotary element connected to the first rotary machine so as to transmit power; A differential unit including a differential mechanism having a third rotating element coupled to a drive wheel, wherein a differential state of the differential mechanism is controlled by controlling an operation state of the first rotating machine; A control device for a vehicle including a second rotating machine coupled to the drive wheels so as to be capable of transmitting power,
The vehicle includes a first engagement device that forms a first gear position of the transmission portion by engagement, a second engagement device that forms a second gear position of the transmission portion by engagement, and the engine And a third engagement device for connecting the first rotating machine to the first rotating machine.
The engine in an engaged state of one of the first engaging device and the second engaging device, in a released state of the other engaging device, and in an engaged state of the third engaging device; While the engine is running, the operation of the engine is stopped in the released state of the one engagement device, the engaged state of the other engagement device, and the released state of the third engagement device. A switching determination unit that determines whether to perform switching to running engine stop traveling and determines whether there is a fuel efficiency priority request that prioritizes fuel efficiency reduction ;
When it is determined that the switching to the engine stop running is to be performed, and when it is determined that the fuel efficiency priority request is present, after stopping the operation of the engine, the first engagement device and the second While performing the switching of the operating state of each of the engagement device and the third engagement device, when it is determined that there is no fuel efficiency priority request, the third engagement device is switched to the released state. And a running state switching control unit that stops the operation of the engine .

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