JP6547700B2 - Vehicle control device - Google Patents

Description

  According to the present invention, a differential unit is connected to the engine via the transmission unit to control the operating state of the first motor, and the second unit is connected to the drive wheels so that power can be transmitted. The present invention relates to a control device of a vehicle provided with an electric motor.

  A differential mechanism having a first rotating element connected to a first motor, a second rotating element, and a third rotating element connected to a second motor and a drive wheel, a fourth rotating element, an engine A power transmission mechanism having a fifth rotating element connected and a sixth rotating element connected to the second rotating element, and the fourth rotating element, the fifth rotating element, the sixth rotating element A vehicle provided with a switching device for shifting the power transmission mechanism, comprising a first engagement portion provided between any two of the two and a second engagement portion for fixing the fourth rotation element Are known. For example, the vehicle described in Patent Document 1 is that. In this patent document 1, the switching device for transmitting the power of the engine to the differential mechanism and changing the speed of the power transmission mechanism is a planetary gear mechanism and two frictions whose engagement and release are controlled by hydraulic pressure. The transmission including the power transmission mechanism and the switching device includes the engagement portion, and the transmission portion is controlled by controlling the operating state (the state such as engagement or release) of the frictional engagement portion. It is disclosed that switching between high and low is made.

International Publication No. 2013/114594

  By the way, in the vehicle, a third engaging portion, which is an engaging portion for connecting the fifth rotating element to which the engine is connected, and the first rotating element to which the first electric motor is connected, in order to improve fuel consumption. Further, for example, by setting the power transmission mechanism in the neutral state (neutral state) and engaging the engagement portion thereof, power is generated by the first electric motor by the power of the engine, and the generated power is used. It is conceivable to enable series travel by driving the second electric motor. In the vehicle configured as described above, the third engaging portion for connecting either the first engaging portion or the second engaging portion to an engaged state and connecting the engine and the first electric motor is provided. By being in the engaged state, it is also possible to perform parallel step travel by driving the engine and the second electric motor.

  In the vehicle configured in this manner, for example, the engine is driven from the single drive EV mode in which all the engagement portions are released to drive the engagement portions with the first engagement portion or the second engagement portion. When switching to a parallel multi-step mode in which any one of the first engaging portion and the third engaging portion is engaged, the first engaging portion and the second engaging portion are If the engine is started with the third engaging portion engaged while the released state is established, there is a possibility that a delay in torque transmission from the engine may occur, and, for example, the first engaging portion or the first engaging portion If the engine is started with one of the two engaging portions engaged and the third engaging portion kept released, vibration or shock may occur when the engine is started.

  The present invention has been made against the background described above, and an object of the present invention is to provide a control method for the engine in the case where a request for switching to a parallel stepped mode occurs during traveling in the single drive EV mode. It is an object of the present invention to provide a control device of a vehicle capable of preventing any occurrence of vibration or shock at the time of start-up, or occurrence of a delay in torque transmission from the engine.

  According to a first aspect of the present invention, there is provided: (a) a differential having a first rotating element connected to a first electric motor, a second rotating element connected to a first electric motor, and a third rotating element connected to a second electric motor and a drive wheel Power transmission mechanism having a mechanism, a fourth rotation element, a fifth rotation element connected to the engine, and a sixth rotation element connected to the second rotation element, the fourth rotation element, the fifth rotation element And a first engagement portion provided between any two of the sixth rotation elements, and a second engagement portion for fixing the fourth rotation element, (b) the vehicle Further includes a third engagement portion provided between the first rotation element and the fifth rotation element, the first engagement portion, the second engagement portion, and the third engagement portion The single drive EV mode, in which the vehicle travels with the drive power of the second electric motor By bringing either the first engaging portion or the second engaging portion into engagement with the third engaging portion, the driving force between the engine and the second electric motor or the engine and the second A control device for a vehicle having a parallel stepped mode traveling with a driving force of an electric motor and a first electric motor, wherein (c) switching is performed to determine a request for switching from the single drive EV mode to the parallel stepped mode A determination unit, an acceleration request determination unit determining whether the acceleration request to the vehicle is equal to or more than a predetermined value, and a request to switch to the parallel stepped mode are determined, and the acceleration request to the vehicle is the When it is equal to or more than a predetermined value, either the first engaging portion or the second engaging portion is engaged, and the engine is started with the third engaging portion kept released. And the point of switching to the parallel multistage mode Is determined, and the acceleration request to the vehicle is less than the predetermined value, the third engaging portion is engaged while the first engaging portion and the second engaging portion are in the released state. And an engine start control unit configured to execute the start of the engine as a state.

  According to the first aspect of the invention, when a request to switch to the parallel multistage mode is generated during traveling in the single drive EV mode, whether the driver's acceleration request to the vehicle is equal to or more than a predetermined value If the value is equal to or greater than a predetermined value, either the first engaging portion or the second engaging portion is engaged, and the engine is started with the third engaging portion kept released. The execution suppresses the delay in torque transmission from the engine. When the driver's acceleration request to the vehicle is large, even if a shock occurs at the time of starting the engine, the driver is less likely to feel discomfort, and the driver's acceleration request is satisfied more It becomes. In addition, it is determined whether the driver's acceleration request to the vehicle is equal to or more than a predetermined value, and when it is less than the predetermined value, the first engagement portion and the second engagement portion remain in the released state. Vibration and shock at the time of starting the engine can be suppressed by executing the start of the engine with the third engagement portion in the engaged state.

While demonstrating the schematic structure of each part in connection with driving | running | working of the vehicle to which this invention is applied, it is a figure explaining the principal part of the control system for controlling each part. It is a figure which shows an example of the driving power source switching map used for the switching control of engine driving | running | working and motor driving | running | working. It is a chart showing each operation state of each engaging part in each run mode. It is an alignment chart at the time of single drive EV mode. It is an alignment chart at the time of both drive EV mode. It is an alignment chart at the time of series parallel low mode of HV driving mode. It is an alignment chart at the time of series parallel high mode of HV driving mode. It is a collinear diagram at the time of series mode of HV driving mode. It is an alignment chart at the time of parallel low mode of HV driving mode. It is an alignment chart at the time of parallel high mode of HV driving mode. The main part of the control operation of the electronic control unit, that is, when switching to the parallel stepped mode occurs during traveling in the EV single drive mode, engagement of the engagement portion and engine start are made based on the magnitude of acceleration request. It is a flowchart explaining the control action to implement. FIG. 12 is a diagram showing an example of a time chart in the case where the acceleration request is equal to or more than a predetermined value in the control operation shown in the flowchart of FIG. 11. FIG. 12 is a diagram showing an example of a time chart when an acceleration request is less than a predetermined value in the control operation shown in the flowchart of FIG. 11.

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

  FIG. 1 is a view for explaining a schematic configuration of each part related to traveling of a vehicle 10 to which the present invention is applied, and a view for explaining a main part of a control system for controlling each part. In FIG. 1, a vehicle 10 can be a driving power source for traveling, an engine 12, a first electric motor MG1, and a second electric motor MG2, a power transmission device 14 corresponding to the power transmission mechanism of the present invention, and driving wheels 16 And a hybrid vehicle.

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

  The first electric motor MG1 and the second electric motor MG2 are so-called motor generators having a function as an electric motor (motor) for generating a driving torque and a function as a generator (generator). The first motor MG1 and the second motor MG2 are connected to the battery unit 20 via a power control unit 18 having an inverter unit, a smoothing capacitor, etc., and the power control unit 18 is controlled by an electronic control unit 80 described later. As a result, the MG1 torque Tmg1 and the MG2 torque Tmg2 that are the output torques (powering torque or regenerative torque) of the first motor MG1 and the second motor MG2 are controlled.

  The power transmission device 14 is provided on a power transmission path between the engine 12 and the drive wheel 16, and is housed together with the first electric motor MG1 and the second electric motor MG2 in the case 22 which is a non-rotational member attached to the vehicle body. It is done. The power transmission device 14 fixes the driven gear 30 and the driven gear 30 engaged with the first power transmission unit 24, the second power transmission unit 26, and the drive gear 28 which is an output rotating member of the first power transmission unit 24 relatively non-rotatably. The final gear 34 (final gear 34 having a diameter smaller than that of the driven gear 30) fixed non-rotatably to the driven shaft 32 and the driven shaft 32, the differential gear 38 meshing with the final gear 34 via the differential ring gear 36 Prepare for The power transmission device 14 also includes an axle 40 and the like connected to the differential gear 38.

  The first power transmission unit 24 is coaxially disposed with the input shaft 42, which is an input rotation 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 functioning as a differential mechanism, a clutch C1 functioning as a first engagement portion, and a brake B1 functioning as a second engagement portion. The differential portion 46 includes a second planetary gear mechanism 50 that functions as a power transmission mechanism and a clutch CS that functions as a third engagement portion.

  The first planetary gear mechanism 48 meshes with the first sun gear S1 via the first sun gear S1, the first pinion gear P1, the first carrier CA1 supporting the first pinion gear P1 rotatably and revolvably, and the first pinion gear P1. It is a known single pinion type planetary gear mechanism having a ring gear R1 and functions as a differential mechanism that produces a differential action. The first planetary gear mechanism 48 is an input-side differential mechanism disposed closer to the engine 12 than the second planetary gear mechanism 50. The first carrier CA1 is a rotating element (for example, the fifth rotating element RE5) to which the engine 12 is connected so as to be able to transmit power via the input shaft 42. It functions as an input rotary member. The first sun gear S1 is a rotating element (for example, a fourth rotating element RE4) selectively coupled to the case 22 via the brake B1. The first ring gear R1 is a rotating element (for example, the sixth rotating element RE6) connected to the input rotating member of the differential unit 46 (ie, the second carrier CA2 of the second planetary gear mechanism 50). It functions as a rotating member. Further, the first carrier CA1 and the first sun gear S1 are selectively connected via the clutch C1.

  The clutch C1 and the brake B1 are preferably wet friction engagement portions, and are multi-plate hydraulic friction engagement portions engaged and controlled by a hydraulic actuator. The clutch C1 and the brake B1 are operated according to the hydraulic pressure supplied from the hydraulic control circuit 52 by the hydraulic control circuit 52 provided in the vehicle 10 being controlled by the electronic control unit 80 described later. Conditions such as release and release) are controlled.

  When the clutch C1 and the brake B1 are both 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 can not be obtained by the first sun gear S1, the transmission unit 44 is brought into a neutral state (neutral state) in which mechanical power transmission can not be performed. Further, in the state in which the clutch C1 is engaged and the brake B1 is released, the first planetary gear mechanism 48 integrally rotates the respective rotating elements. Therefore, in this state, the rotation of the engine 12 is transmitted at the same speed from the first ring gear R1 to the second carrier CA2. On the other hand, in the state where the clutch C1 is released and the brake B1 is engaged, the rotation of the first sun gear S1 is stopped and the rotation of the first ring gear R1 is rotated of the first carrier CA1. It is accelerated more than. Therefore, in this state, the rotation of the engine 12 is accelerated and output from the first ring gear R1. In this manner, the transmission unit 44 is a two-stage stepped transmission that can be switched between a low gear in a direct connection state (gear ratio = 1.0) and a high gear in an overdrive state (for example, gear ratio = 0.7). Act as. The clutch C1 is a first engagement portion that forms a low gear as a first gear of the transmission 44 by engagement, and the brake B1 is engaged with a high gear as a second gear of the transmission 44 by engagement. It is a 2nd engaging part to form. Therefore, when one of the clutch C1 and the brake B1 is engaged, the transmission unit 44 is formed with either the first or second gear and is not capable of mechanical power transmission. It is considered neutral. In addition, in the state where the clutch C1 and the brake B1 are engaged together, the rotation of each rotating element of the first planetary gear mechanism 48 is stopped. Therefore, in this state, by stopping the rotation of the first ring gear R1 which is the output rotary member of the transmission unit 44, the rotation of the second carrier CA2 which is the input rotary member of the differential unit 46 is stopped.

  The second planetary gear mechanism 50 meshes with the second sun gear S2 via the second sun gear S2, the second pinion gear P2, and the second carrier CA2 that supports the second pinion gear P2 rotatably and revolvably, 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 produces a differential action. The second planetary gear mechanism 50 is an output-side differential mechanism disposed closer to the drive wheel 16 than the first planetary gear mechanism 48. The second carrier CA2 is a rotating element (eg, the second rotating element RE2) as an input element connected to the output rotating member of the transmission unit 44 (ie, the first ring gear R1 of the first planetary gear mechanism 48). It functions as an input rotary member of the part 46. The second sun gear S2 is integrally connected to the rotor shaft 54 of the first electric motor MG1, and is a rotating element (eg, the first rotating element RE1) as a reaction force element connected to the first electric motor MG1 so as to transmit power. It is. The second ring gear R2 is integrally connected to the drive gear 28 and is a rotating element (for example, the third rotating element RE3) as an output element connected to the drive wheel 16, and an output rotating member of the differential unit 46 Act as. The second sun gear S2 is selectively coupled to the first carrier CA1 via the clutch CS. Therefore, the clutch CS is a third engagement portion that selectively connects the engine 12 connected to the first carrier CA1 and the first electric motor MG1 connected to the second sun gear S2.

  The clutch CS is preferably a wet friction engagement portion, and is a multi-plate hydraulic friction engagement portion engaged and controlled by a hydraulic actuator. The clutch CS is actuated (engaged or released) according to the hydraulic pressure (for example, CS hydraulic pressure Pcs) supplied from the hydraulic control circuit 52 by the hydraulic control circuit 52 being controlled by the electronic control unit 80 described later. State is controlled.

  When 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 electric motor MG1 and the second ring gear R2. That is, in addition to the mechanical power transmission distributed to the second ring gear R2 in the differential section 46, the first electric motor MG1 is generated by the power distributed to the first electric motor MG1, and the generated electric power is stored. The second electric motor MG2 is driven by the electric power. Thereby, the electric power control unit 18 is controlled by the electronic control unit 80 described later to control the operating state of the first electric motor MG1 and thereby the differential portion 46 controls the gear ratio (gear ratio) by a known electric type. It functions as a differential unit (electric continuously variable transmission). That is, the differential unit 46 is a differential motor coupled to the second planetary gear mechanism 50 as a second planetary gear mechanism 50 as a differential mechanism coupled to the engine 12 so as to be able to transmit power. The first electric motor MG1 is an electric transmission mechanism in which the differential state of the second planetary gear mechanism 50 is controlled by controlling the operating state of the first electric motor MG1. Further, in the state where the clutch CS is engaged, the engine 12 and the first electric motor MG1 are connected, so the first electric motor MG1 generates electric power by the power of the engine 12 and stores the generated electric power. The electric power can drive the second electric motor MG2.

  In the first power transmission unit 24 configured as described above, the power of the engine 12 and the power of the first electric motor MG1 are transmitted from the drive gear 28 to the driven gear 30. Therefore, the engine 12 and the first electric motor MG1 are coupled to the drive wheel 16 so as to be able to transmit power via the first power transmission unit 24. In addition, since the transmission unit 44 is overdrive, the increase in torque of the first electric motor MG1 is suppressed.

  The second power transmission unit 26 meshes with the rotor shaft 56 of the second motor MG2 and the driven gear 30, which are disposed in parallel to the input shaft 42 separately from the input shaft 42, and a reduction gear connected to the rotor shaft 56 58 (reduction gear 58 smaller in diameter than driven gear 30) is provided. Thereby, in the second power transmission unit 26, the power of the second electric motor MG2 is transmitted to the driven gear 30 without passing through the first power transmission unit 24. Accordingly, the second electric motor MG2 is coupled to the drive wheel 16 so as to be able to transmit power without passing through the first power transmission unit 24. That is, the second electric motor MG2 is an electric motor connected to the axle 40, which is an output rotating member of the power transmission device 14, so as to be capable of transmitting power without the intervention of the first power transmission portion 24. In addition to the axle shaft 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 14 configured in this way is suitably used for a 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 motor MG1 and the power of the second motor MG2 are transmitted to the driven gear 30, and from the driven gear 30, the final gear 34, the differential gear 38, the axle 40, etc. Are sequentially transmitted to the drive wheel 16. Further, in the power transmission device 14, the axial length is shortened by arranging the engine 12, the first power transmission portion 24, the first electric motor MG1, and the second electric motor MG2 on different axial centers. . Also, the reduction ratio of the second electric motor MG2 can be made large.

  The vehicle 10 is provided with an electronic control device 80 including a control device that controls each part involved in traveling. The electronic control unit 80 is configured to include, for example, a so-called microcomputer provided with a CPU, a RAM, a ROM, an input / output interface and the like, and the CPU follows a program stored in advance in the ROM using a temporary storage function of the RAM. By performing signal processing, various controls of the vehicle 10 are executed. For example, the electronic control unit 80 executes output control of each of the engine 12, the first electric motor MG1, and the second electric motor MG2, switching control of a traveling mode to be described later, and the like. , For motor control, oil pressure control, etc.

  The electronic control unit 80 includes various sensors (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, etc. An output rotational speed Nout (rpm) which is the rotational speed of the driven gear 30 corresponding to the vehicle speed V and various signals (for example, engine rotational speed Ne (rpm)) based on detected values by the degree sensor 68, shift position sensor 70, battery sensor 72 etc. , MG1 rotational speed Nmg1 (rpm), MG2 rotational speed Nmg2 (rpm), accelerator opening θacc (%), shift lever operation position Psh, battery temperature of battery unit 20 THbat (° C.), battery charge / discharge current Ibat (A And battery voltage Vbat (V) etc.). Further, from the electronic control unit 80, various command signals (for example, an engine control command signal Se, a motor control command signal Sm, and the like to each device (for example, the engine 12, the power control unit 18, the hydraulic control circuit 52) provided in the vehicle 10 , 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 hybrid control means, that is, a hybrid control unit 82, and engagement operation control means, that is, an engagement operation control unit 84, in order to realize control functions for various controls in the vehicle 10.

  The hybrid control unit 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 can be obtained. The output control of the engine 12 is executed. In addition, the hybrid control unit 82 outputs the motor control command signal Sm for controlling the operation of the first motor MG1 and the second motor MG2 to the power control unit 18, and the target torque of the MG1 torque Tmg1 and the MG2 torque Tmg2 can be obtained. Thus, the output control of the first motor MG1 and the second motor MG2 is executed.

  The hybrid control unit 82 calculates the driving torque (required driving torque) required at the vehicle speed V at that time from the accelerator opening degree θacc, and takes into consideration the required charging value (required charging power) etc. The required driving torque is generated from at least one of the engine 12, the first electric motor MG1, and the second electric motor MG2 so as to achieve an operation with a small amount of driving.

  Hybrid control unit 82 selectively establishes a motor travel mode (EV travel mode) or a hybrid travel mode (HV travel mode) as the travel mode according to the travel state. The EV travel mode enables motor travel (EV travel) in which the operation of the engine 12 is stopped and at least one of the first electric motor MG1 and the second electric motor MG2 is used as a driving power source for traveling. It is a control style. The HV travel mode is a control mode that enables engine travel that travels at least the engine 12 as a drive power source for travel (that is, travels by transmitting the power of the engine 12 to the drive 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 electric motor MG1, and the electric power drives the second electric motor MG2 to drive If it is, it is included in the HV driving mode. That is, in such a case, the engine torque Te is not mechanically transmitted to the drive wheels 16, but since the power source based on which the second electric motor MG2 is driven is the engine 12, this traveling (that is, series traveling described later) is also Included in engine driving.

  The hybrid control unit 82 further includes switching determination means, that is, a switching level reduction unit 86, and the switching determination unit 86 uses the vehicle speed V and the required drive torque as variables to drive the engine travel area and the motor travel area (single drive area, both The vehicle speed V and the demand drive are in the relationship (driving power source switching map) as shown in FIG. 2 which is determined and stored in advance (designally determined) experimentally or designly having a boundary with the driving region By applying the torque, it is determined whether the traveling state is in the motor traveling region or the engine traveling region. If the hybrid control unit 82 determines that the switching determination unit 86 is in the motor travel region, the hybrid control unit 82 establishes the EV travel mode while establishing the HV travel mode if it is determined in the engine travel region. . In addition, even when the traveling state is in the motor traveling region, the switching judgment break 86 is that when the battery temperature THbat is low or the charge capacity SOC is low and the power that can be output from the battery unit 20 is limited. If the engine 12 needs to be warmed up, it is determined that the HV travel mode is established so as to operate the engine 12. As shown in FIG. 2, the motor travel area (single drive area, both drive areas) is in a low vehicle speed area of the vehicle speed V or a low torque area of the required drive torque as compared with the engine travel area.

  When hybrid control unit 82 establishes the EV travel mode, switching determination unit 86 further applies the vehicle speed V and the required driving torque to the driving power source switching map as shown in FIG. It is determined which of the two drive areas is in. For example, in the case where the request driving torque is exceeded by only the second motor MG2, the switching determination unit 86 determines that the single drive EV mode is established while the request driving torque can not be exceeded by the second motor MG2. Determines the establishment of the both drive EV mode. When hybrid control unit 82 establishes the single drive EV mode, switching determination unit 86 enables EV travel using only second electric motor MG2 as a drive power source for travel, while both drive EV mode In the case where the above condition is established, it is possible to perform EV travel with both the first electric motor MG1 and the second electric motor MG2 as a driving power source for traveling. Even when the requested drive torque is exceeded by the second motor MG2 alone, the switching determination unit 86 sets the efficiency of the second motor MG2 to the operating point of the second motor MG2 represented by the MG2 rotation speed Nmg2 and the MG2 torque Tmg2. If the operating point to be deteriorated is within a predetermined area (in other words, if it is more efficient to use the first motor MG1 and the second motor MG2 in combination), it is determined to select the both drive EV mode Do. When both drive EV modes are established, the hybrid control unit 82 causes the first motor MG1 and the second motor MG2 to share the required drive torque based on the operating efficiencies of the first motor MG1 and the second motor MG2. .

  When the traveling state is in the engine traveling region and the hybrid control unit 82 establishes the HV traveling mode, the switching determination unit 86 determines, for example, the establishment of the series parallel mode. When the series parallel mode is established, the hybrid control unit 82 transmits the direct engine torque to the drive gear 28 by receiving the reaction force against the power of the engine 12 by the power generation of the first electric motor MG1, and transmits the first electric motor MG1. The second electric motor MG2 is driven by the generated electric power to transmit torque to the drive wheels 16 to enable engine travel. That is, when the series parallel mode is established, the hybrid control unit 82 can perform series parallel traveling in which the power of the engine 12 is transmitted to the driving wheels 16 to control by controlling the operating state of the first electric motor MG1. I assume. In the series parallel mode, hybrid control unit 82 operates engine 12 at an engine operating point (that is, an engine operating point represented by engine rotational speed Ne and engine torque Te) in consideration of the optimum fuel consumption line of known engine 12. Activate. In the series parallel mode, it is also possible to drive the second motor MG2 by adding the power from the battery unit 20 to the power generated by the first motor MG1.

  When the traveling state is in the motor travel region (single drive region, both drive regions), the switching determination unit 86 is configured to limit the power that can be output from the battery unit 20 or when the engine 12 needs to be warmed up. For example, it is determined that the HV travel mode is established. For example, in the case where the HV traveling mode is established when the traveling state is in both drive regions, the switching determination unit 86 establishes the HV traveling mode when the traveling state is in the single drive region while establishing the series parallel mode. If it is determined that the series mode has been established. When the series mode is established, the hybrid control unit 82 operates the engine 12 to generate the first electric motor MG1, and drives the second electric motor MG2 by the generated electric power of the first electric motor MG1, thereby driving the driving wheel 16 The MG2 torque Tmg2 is transmitted to enable series traveling. Note that this series mode can be performed even when the power that can be output from the battery unit 20 is not limited, and in such a case, it can be viewed that the single drive region can be further expanded.

  When the hybrid control unit 82 causes the HV travel mode to be established, the switching determination unit 86 can also determine that the parallel stepped mode is established. When the hybrid control unit 82 establishes the parallel stepped mode, in addition to the power of the engine 12, the power of the first electric motor MG1 and / or the power of the second electric motor MG2 is transmitted to the drive wheel 16 to travel It is also possible to judge the establishment of parallel stepped travel. This parallel stepped mode is useful in a traveling state in which the required driving torque is large or the vehicle speed V is high.

  The engagement operation control unit 84 controls the 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 engagement operation control unit 84 engages and / or respectively engages the clutch C1, the brake B1, and the clutch CS such that power transmission for traveling in the traveling mode established by the hybrid control unit 82 becomes possible. A hydraulic pressure control command signal Sp to be released is output to the hydraulic pressure control circuit 52.

  Here, travel modes that can be executed by the vehicle 10 will be described with reference to FIGS. 3 and 4 to 10. FIG. 3 is a chart showing operating states of the clutch C1, the brake B1 and the clutch CS in each traveling mode. Circles in the chart of FIG. 3 indicate engagement of the engaging portions (C1, B1 and CS), blanks indicate release, and triangles indicate that the engine brake in which the engine 12 in the stop state is brought into co-op It also indicates engaging one or the other at the same time. Also, "G" indicates that the motor (MG1, MG2) mainly functions as a generator, and "M" mainly functions the motor (MG1, MG2) as a motor during driving, and functions as a generator mainly during regeneration. It indicates that As shown in FIG. 3, the vehicle 10 can selectively realize an EV travel mode and an HV travel mode as travel modes. The EV travel mode has two modes of a single drive EV mode and a both drive EV mode. The HV traveling mode has three modes of series parallel mode, parallel stepped mode and series mode.

  FIGS. 4 to 10 can relatively represent the rotational speeds of the six rotating elements RE1, RE2, RE3, RE4, RE5, RE6 in each of the first planetary gear mechanism 48 and the second planetary gear mechanism 50. FIG. FIG. 4 is an alignment chart in the single drive EV mode. The single drive EV mode is realized in a state where the clutch C1, the brake B1 and the clutch CS are all released as shown in FIG. In the single drive EV mode, as shown in FIG. 4, by disengaging the clutch C1 and the brake B1, the differential of the first planetary gear mechanism 48 is permitted, and the transmission portion 44 is brought into the neutral state. When the transmission unit 44 is brought into the neutral state, the reaction force torque of the MG1 torque Tmg1 can not be obtained by the second carrier CA2 connected to the first ring gear R1, and hence the differential unit 46 is brought into the neutral state. The transmission unit 24 is also in a neutral state. In this state, the hybrid control unit 82 causes the second electric motor MG2 to output the traveling MG2 torque Tmg2 while stopping the operation of the engine 12.

  FIG. 5 is an alignment chart in the both drive EV mode. Both drive EV modes (“Ne = 0”) are realized in a state in which the clutch C1 and the brake B1 are engaged and in a state in which the clutch CS is released, as shown in FIG. In this both drive EV mode, as shown in FIG. 5, the clutch C1 and the brake B1 are engaged, whereby the differential of the first planetary gear mechanism 48 is restricted, and the rotation of the first sun gear S1 is stopped. . Therefore, the rotation of the first planetary gear mechanism 48 is stopped for any of the rotating elements. As a result, 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 by the second carrier CA2, so the MG1 torque Tmg1 is mechanically output from the second ring gear R2 and transmitted to the drive wheel 16 be able to.

  FIG. 6 is an alignment chart in series parallel mode (hereinafter referred to as series parallel low mode) in the 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 in 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, the differential of the first planetary gear mechanism 48 is restricted by engaging the clutch C1, 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 the series parallel mode (hereinafter referred to as series parallel high mode) in the high state of the HV traveling mode. The series parallel high mode is realized in a state in which the brake B1 is engaged and in a state in which the clutch C1 and the clutch CS are 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.

  FIG. 8 is an alignment chart in the series mode of the HV traveling mode. The series mode is realized with the clutch C1 and the brake B1 both released and the clutch CS engaged as shown in FIG. In the series mode, as shown in FIG. 8, as the clutch C1 and the brake B1 are released, the differential of the first planetary gear mechanism 48 is allowed, and the transmission portion 44 is brought into the neutral state.

  FIG. 9 is an alignment chart in a parallel stepped mode (hereinafter referred to as parallel low mode) in the 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 in a state in which the brake B1 is released, as shown in FIG. In the parallel low mode, as shown in FIG. 9, as the clutch C1 is engaged, the differential of the first planetary gear mechanism 48 is restricted, and the rotary 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 clutch CS is engaged to connect the engine 12 and the first electric motor MG1.

  FIG. 10 is an alignment chart in the parallel stepped mode (hereinafter referred to as “parallel high mode”) in the high state of the HV traveling mode. The parallel high mode is realized in a state in which the brake B1 and the clutch CS are engaged and in a state in which the clutch C1 is released, as shown in FIG. In the parallel high mode, as shown in FIG. 10, 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 addition, in the parallel high mode, the clutch CS is engaged to connect the engine 12 and the first electric motor MG1.

  In the parallel stepped mode, in addition to the connection between the engine 12 and the first electric motor MG1 by the engagement of the clutch CS, the gear ratio of the transmission portion 44 is fixed by the engagement of the clutch C1 or the brake B1. The gear ratio of the first power transmission unit 24 (i.e., the overall gear ratio of the transmission unit 44 and the differential unit 46) is fixed. In parallel stepped travel, the engine travel speed Ne is uniquely determined with respect to the vehicle speed V (output rotational speed Nout), and thus, a stepped travel state is set.

  The operating state of each engaging portion (C1, B1, CS) in the parallel stepped mode is the same as in the both drive EV mode ("Ne free") shown in FIG. That is, the alignment charts of FIG. 9 and FIG. 10 are alignment charts of both drive EV modes (“Ne free”) when the operation of the engine 12 is stopped. In this both drive EV mode ("Ne free"), the drive power of the first electric motor MG1 and the power of the second electric motor MG2 are transmitted to the drive wheels 16 as in both drive EV modes ("Ne = 0") It is possible. However, in the both drive EV mode (“Ne free”), the engine rotational speed Ne is uniquely determined according to the vehicle speed V during traveling, and therefore the engine rotational speed Ne can not be made zero. It differs from the EV mode ("Ne = 0").

  When the switching from the single drive EV mode to the parallel stepped mode occurs, the electronic control unit 80 determines the timing of engagement of the clutch C1, the brake B1 and the clutch CS depending on whether the required drive torque is equal to or greater than a predetermined value. In order to realize the control to rearrange the speed, an acceleration request determination means, that is, an acceleration request determination unit 88, and an engine start control means, that is, an engine start control unit 90 are further provided.

  The switching determination unit 86 calculates the driving torque required from the accelerator opening θacc and the vehicle speed V at that time, and takes the charging request value (charging request power) and the like into consideration from the single drive EV mode to the parallel stepped mode. It is determined whether it is necessary to switch. When switching determination unit 86 determines switching from the single drive EV mode to the parallel stepped mode, acceleration request determination unit 88 determines whether accelerator depression speed Δθ is greater than or equal to predetermined value A by accelerator opening sensor 68, for example. Determine the size of the acceleration request. If the acceleration request determination unit 88 determines that the depression speed Δθ of the accelerator is equal to or greater than the predetermined value A, the engagement operation control unit 84 places the brake B1 or the clutch C1 in the engaged state based on the determination of the acceleration request determination unit 88. With the clutch CS kept in the released state, the engine start control unit 90 controls the start of the engine 12 and starts the engine 12 after the engagement described above. By this, when the driver's acceleration request is large, that is, when the depression speed Δθ of the accelerator is a predetermined value A or more, either the clutch C1 or the brake B1 is engaged and the clutch CS is kept released. As the engine 12 is started, a delay in torque transmission from the engine 12 is suppressed. If the acceleration request determination unit 88 determines that the depression speed Δθ of the accelerator falls below the predetermined value A, the engagement operation control unit 84 places the clutch CS in the engagement state based on the determination of the acceleration request determination unit 88. By starting the engine 12 with the brake B1 and the clutch C1 kept in the released state, the vibration and shock at the start of the engine 12 are suppressed.

  FIG. 11 is a main part of the control operation of the electronic control unit 80, that is, when switching from the single drive EV mode to the parallel stepped mode occurs, the clutch C1, the brake B1 and the clutch are By rearranging the order of CS and the start of the engine 12, the delay in torque transmission from the engine 12 is suppressed when the accelerator depression speed Δθ is large, and the accelerator depression speed Δθ is small. 4 is a flowchart illustrating control operation for suppressing vibration and shock at the start of the engine 12, and is repeatedly executed.

  In FIG. 11, in step (hereinafter, step will be omitted) S10 corresponding to the function of the switching determination unit 86, it is determined whether or not the single drive EV mode, that is, single drive EV traveling. If the S10 determination is negative, this routine is ended. If the determination in S10 is affirmative, it is determined in S20 corresponding to the function of the switching determination unit 86 whether switching from the single drive EV mode to the parallel stepped mode has occurred. If the determination in S20 is negative, this routine is ended. If the determination in S20 is affirmative, it is determined in S30 corresponding to the function of the acceleration request determination unit 88 whether the acceleration request, that is, the depression speed Δθ of the accelerator is a predetermined value A or more. If the determination is affirmative, in S40 where the functions of the engagement operation control unit 84 and the engine start control unit 90 correspond, the engagement of the brake B1 or the clutch C1, the start of the engine 12, the engagement of the clutch CS Control is performed in order. Specifically, when the switching determination unit 86 determines switching to the high mode in the parallel stepped mode, ie, the parallel high mode, the brake B1 is engaged before the engine 12 is started. When the switching determination unit 86 determines switching to the low mode in the parallel stepped mode, that is, the parallel low mode, the clutch C1 is engaged before the engine 12 is started. If the determination in S30 is negative, in S50 where the functions of the engagement operation control unit 84 and the engine start control unit 90 correspond, the engagement of the clutch CS, the start of the engine 12, the engagement of the brake B1 or the clutch C1 Control is performed in the order of Specifically, when the switching determination unit 86 determines switching to the parallel high mode, the brake B1 is engaged after the engine 12 is started. When the switching determination unit 86 determines switching to the parallel low mode, the brake C1 is engaged after the engine 12 is started.

  In switching from the single drive EV mode to the parallel stepped mode, the hybrid control unit 82 operates the first electric motor MG1 at the start of the engine 12 after the engagement operation of any one of the brake B1, the clutch C1 and the clutch CS. A so-called cranking is performed to assist driving and start-up rotation of the engine 12. When the switching determination unit 86 determines both driving, the hybrid control unit 82 determines the outputs of the first motor MG1, the second motor MG2, and the engine 12 and continues the output from the first motor MG1. When the switching determination unit determines single drive, the hybrid control unit 82 switches between the second electric motor MG2 and the engine 12, and the output from the first electric motor MG1 is stopped.

  FIG. 12 shows an example in which switching from the single drive EV mode to the parallel stepped mode occurs and the acceleration request, that is, the depression speed Δθ of the accelerator is equal to or more than a predetermined value A. This example shows the switching from the single drive EV mode to the parallel low drive, that is, to the travel mode in which the first electric motor MG1 and the second electric motor MG2 are used for driving together with the engine 12 in parallel low. The increase of the accelerator opening θacc starts at time t1, and at time t2, the stepping speed Δθ of the accelerator is equal to or greater than the predetermined value A, and the parallel low is selected. A control action is selected which leaves CS in the released state. The rotational speed Nmg1 of the first electric motor MG1 rises from time t2 and shows approximately zero at time t3. From time t3, the hydraulic pressure command value of the clutch C1 is increased, and the clutch C1 is engaged. From time t4, the rotational speed Nmg1 of the first electric motor MG1 increases, and at time t5, the engine 12 is ignited, ie, started. At time t6, the hydraulic pressure command value of the clutch CS rises, and when engagement of the clutch CS is completed at time t7, the rotational speed Ne of the engine 12, the rotational speed Nmg1 of the first electric motor MG1 and the rotation of the second electric motor MG2 The speed Nmg2 is set as the rotational speed determined by the hybrid control unit 82, and switching to the parallel low drive mode is performed.

  FIG. 13 shows an example in which switching from the single drive EV mode to the parallel stepped mode occurs and the acceleration request, that is, the stepping speed Δθ of the accelerator falls below a predetermined value A. This example shows switching from the single drive EV mode to parallel low drive. The increase of the accelerator opening degree θacc is started at time t1, and when it is determined that the depression speed Δθ of the accelerator falls below the predetermined value A at time t2, a control operation for engaging the clutch CS is selected. The rotational speed Nmg1 of the first electric motor MG1 rises from time t2 and shows substantially zero at time t3. From time t3, the hydraulic pressure command value of the clutch CS rises, and the clutch CS is engaged. From time t4, the rotational speed Nmg1 of the first electric motor MG1 increases, and at time t5, the engine 12 is ignited, ie, started. At time t6, the hydraulic pressure command value of the clutch C1 rises, and when engagement of the clutch C1 is completed at time t7, the rotational speed Ne of the engine 12, the rotational speed Nmg1 of the first electric motor MG1, the second electric motor MG2 The rotation speed Nmg2 of the motor is determined as the rotation speed determined by the hybrid control unit 82, and switching to the parallel low drive mode is performed.

  In the power transmission device 14 of the present embodiment, the first carrier CA1 and the first sun gear S1 are selectively coupled via the clutch C1, and the first sun gear S1 is selectively coupled to the brake B1. Further, the engine 12 and the first electric motor MG1 are selectively connected via a clutch CS. In such a power transmission device 14, when a request to switch to the parallel stepped mode is generated during traveling in the single drive EV mode, for example, the clutch C1 and the brake B1 are kept in the released state and the clutch CS is engaged. When the engine 12 is started and the clutch CS is engaged after the start of the engine 12, a delay in torque transmission may occur. Further, for example, when either the clutch C1 or the brake B1 is engaged and the clutch CS is engaged after the start of the engine 12, there is a possibility that vibration or shock may occur at the start of the engine. As described above, according to this embodiment, when a request to switch to the parallel stepped mode is generated during traveling in the single drive EV mode, the acceleration request from the driver is large, that is, the accelerator depression speed Δθ. Is greater than the predetermined value A, the torque transmission delay from the engine 12 is suppressed by starting the engine 12 with the clutch C1 or the brake B1 engaged and the clutch CS kept released. Be done. As described above, when the driver's acceleration request to the vehicle is large, the possibility of giving a sense of discomfort to the driver is low even if the vibration or shock at the time of starting the engine 12 occurs. Meet the people's acceleration requirements more. On the other hand, when the driver's request for acceleration to the vehicle 10 is low, that is, when the stepping speed Δθ of the accelerator does not exceed the predetermined value, the clutch C1 and the brake B1 are kept released and the clutch CS is engaged. As the engine 12 is started, it is possible to suppress vibration and shock at the start of the engine 12.

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

  In the above embodiment, when the magnitude of the acceleration request is determined by the depression speed Δθ of the accelerator and the depression speed Δθ of the accelerator is equal to or more than the predetermined value A, an engagement that can suppress the delay in torque transmission, ie, The brake B1 or the clutch C1 is engaged, the clutch CS is kept released, the engine 12 is started, and after starting the engine 12, the clutch CS is engaged. However, the invention is not limited thereto. Sport mode or power mode that realizes a shift mode that enables traveling at a lower speed, that is, high torque compared to a normal shift mode, or a manual mode that enables any shift stage based on the driver's operation At the time of acceleration in the case of the above case, the acceleration request determination unit 88 determines that the acceleration request is large, and the engagement operation control unit 84 selects the above-mentioned engagement. It may be.

  Further, in the above-described embodiment, the vehicle 10 is a gear train of a connection relationship such that the second electric motor MG2 is disposed on an axis different from the axis of the first power transmission unit 24. The gear train or the like may be a connection relationship in which the two electric motors MG2 are disposed on the same axial center as the axial center of the first power transmission unit 24. The present invention can be applied to any vehicle as long as the vehicle includes the engine 12, the transmission unit 44, the differential unit 46, and the second electric motor MG2 coupled to the drive wheels 16 so as to be able to transmit power. In addition, although the invention has been described using the power transmission device 14 suitably used for the FF system vehicle 10, the present invention is suitably applied to a power transmission device used for another system vehicle such as the RR system, for example. Can.

  The above description is merely an embodiment, and the present invention can be implemented in variously modified and / or improved modes based on the knowledge of those skilled in the art.

10: Vehicle 12: Engine 14: Power transmission device (power transmission mechanism)
80: Electronic control unit (control unit)
86: switching determination unit 88: acceleration request determination unit MG1: first electric motor MG2: second electric motor S2: first rotating element, second sun gear CA2: second rotating element, second carrier R2: third rotating element, second Ring gear S1: fourth rotating element, first sun gear CA1: fifth rotating element, first carrier R1: sixth rotating element, first ring gear C1: clutch (first engaging portion)
B1: Brake (second engagement part)
CS: clutch (third engagement part)

Claims (1)

A differential mechanism having a first rotating element connected to the first motor, a second rotating element, and a third rotating element connected to the second motor and the drive wheel;
A power transmission mechanism having a fourth rotating element, a fifth rotating element connected to the engine, and a sixth rotating element connected to the second rotating element;
A first engagement portion provided between any two of the fourth rotation element, the fifth rotation element, and the sixth rotation element;
And a second engaging portion for fixing the fourth rotating element.
The vehicle further includes a third engagement portion provided between the first rotation element and the fifth rotation element.
By setting all of the first engaging portion, the second engaging portion, and the third engaging portion in the released state, a single drive EV mode is established in which the vehicle travels with the driving force of the second electric motor. The driving force of the engine and the second electric motor or the engine and the second electric motor by bringing either the first engaging part or the second engaging part into engagement with the third engaging part A control device of a vehicle having a parallel multi-step mode that travels with a driving force with a first motor,
A switching determination unit that determines a request for switching from the single drive EV mode to the parallel multistage mode;
An acceleration request determination unit that determines whether the acceleration request to the vehicle is equal to or greater than a predetermined value;
If a request for switching to the parallel stepped mode is determined and the acceleration request to the vehicle is equal to or greater than the predetermined value, either the first engagement portion or the second engagement portion is engaged. Start the engine while leaving the third engagement portion in the released state,
When the request for switching to the parallel stepped mode is determined and the acceleration request to the vehicle is less than the predetermined value, the first engagement portion and the second engagement portion are kept in the released state. An engine start control unit configured to start the engine with the third engaging portion in an engaged state;
A control device for a vehicle, comprising:

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