JP2018001869A - Hybrid vehicle - Google Patents

Abstract

In a hybrid vehicle configured to be able to select one of a series mode and a series parallel mode, an efficient mode is selected by simple arithmetic processing. A hybrid vehicle includes an engine, a first rotating electrical machine (first MG), an output shaft connected to a drive wheel, a second rotating electrical machine (second MG) connected to the output shaft, an engine, and a first vehicle. A planetary gear mechanism that mechanically connects the 1MG and the output shaft, and a control device configured to be able to select one of the travel modes of the series mode and the series parallel mode. The control device selects the series mode when the engine torque (a parameter correlated with the engine thermal efficiency) when the rotational speed of the first MG is 0 in the series parallel mode is less than the threshold value, and otherwise. Select series parallel mode. [Selection] Figure 15

Description

  The present invention relates to a hybrid vehicle configured to be able to select one of a traveling mode of a series mode and a series parallel mode.

  The hybrid vehicle includes an engine and a motor as driving force sources. Conventionally, series running and series parallel running are known as methods of running using the power of both the engine and the motor.

  The series running is a system in which an engine is connected to a generator, the engine power is transmitted to the generator, temporarily converted into electric power, and the motor is driven by the electric power. That is, in series running, engine power is transmitted to the generator and converted into electric power.

  The series parallel running is a system in which an engine is connected to a generator and driving wheels via a power split mechanism (such as a planetary gear mechanism), and the power of the engine is split and transmitted to the generator and driving wheels. That is, in series parallel travel, part of the engine power is transmitted to the generator and converted into electric power, and the rest is mechanically transmitted to the drive wheels.

  A hybrid vehicle configured to be able to switch between the two traveling methods (series traveling and series parallel traveling) is disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-86725 (Patent Document 1).

JP2012-86725A

  However, Patent Document 1 does not describe the switching condition between the two traveling methods. In addition, it is ideal to calculate the efficiency in each driving method and select the more efficient one, but the efficiency to be considered is the engine thermal efficiency, power transmission efficiency (engine and motor power is transmitted to the drive wheels) (Including the power conversion efficiency of the motor and generator), and calculating all of these multiple efficiency according to the vehicle speed and the required driving force that change every moment There is a concern that it will become excessive and difficult in practice.

  The present disclosure has been made in order to solve the above-described problem, and an object of the present disclosure is to perform simple arithmetic processing in a hybrid vehicle configured to be able to select either the series mode or the series parallel mode. Is to select an efficient mode.

  The hybrid vehicle according to the present disclosure includes an engine, a first rotating electrical machine, an output shaft connected to the drive wheels, a second rotating electrical machine connected to the output shaft, and a first element connected to the first rotating electrical machine. A planetary gear mechanism having a second element and a third element connected to the output shaft, and a switching device configured to be able to switch the connection state between the engine and the planetary gear mechanism to the first state or the second state. Is provided. The first state is a state where the engine is connected to the first element, or a state where the output shaft is disconnected from the third element while the engine is connected to the second element. The second state is a state where the engine is connected to the second element. The hybrid vehicle further includes a control device configured to be able to select either the series mode or the series parallel mode. The series mode is a mode in which the switching device is set to the first state, and engine power is transmitted to the first rotating electrical machine to be converted into electric power. In the series parallel mode, the switching device is set to the second state, and a part of the engine power is mechanically transmitted to the output shaft using the torque of the first rotating electrical machine, while the rest of the engine power is transferred to the first rotating electrical machine or In this mode, the electric power is transmitted to the second rotating electrical machine and converted into electric power. The control device determines which travel mode to select between the series mode and the series parallel mode by executing one of the first control, the second control, and the third control. In the first control, the series mode is selected when the thermal efficiency of the engine is less than the threshold value when the rotation speed of the first rotating electrical machine is assumed to be 0 in the series parallel mode, and the thermal efficiency is greater than the threshold value. In this case, the series parallel mode is selected. The second control selects the series mode when the fuel consumption rate of the engine when the rotational speed of the first rotating electrical machine becomes 0 in the series parallel mode is greater than the second threshold value, and the fuel consumption rate is the second. In this control, the series parallel mode is selected when it is less than the threshold value. The third control selects the series mode when the torque of the engine when the rotational speed of the first rotating electrical machine becomes 0 in the series parallel mode is less than the third threshold value, and the torque exceeds the third threshold value. This is control for selecting the series parallel mode when the value is larger.

  The hybrid vehicle is configured to be able to switch the traveling mode to either the series mode or the series parallel mode by switching the state of the switching device. The two travel modes are common in that the engine is operated to travel, but there is a difference in efficiency as described below.

  In the series mode, the mechanical power transmission between the engine and the output shaft is interrupted by setting the switching device to the first state, so the engine speed is adjusted to the optimum value without being restricted by the vehicle speed. it can. On the other hand, in the series mode, since it is assumed that the second rotating electrical machine is driven by the electric power generated by the first rotating electrical machine, a power conversion loss occurs at a certain rate in each rotating electrical machine. Therefore, in the series mode, the engine thermal efficiency can be optimized, while the power transmission efficiency can be reduced by the amount of power conversion loss compared to the series parallel mode.

  In the series parallel mode, when the rotation speed of the first rotating electrical machine becomes 0, the power conversion loss of the first rotating electrical machine is minimized, and the power transmission efficiency including the power conversion efficiency is maximized. On the other hand, in the series parallel mode, the engine is connected to the second element of the planetary gear mechanism by setting the switching device to the second state, so that the rotational speed of the first rotating electrical machine is set to 0 (maximum power transmission efficiency). And the rotation speed of the engine (rotation speed of the second element) is constrained by the vehicle speed (rotation speed of the output shaft) due to the relationship in the nomograph, and the engine thermal efficiency may not be optimized.

  In view of the difference in efficiency as described above, the control device according to the present disclosure executes any one of the first control, the second control, and the third control, so that one of the travel modes of the series mode and the series parallel mode is performed. Select.

  The first control is a control for selecting the travel mode using the thermal efficiency of the engine when the rotational speed of the first rotating electrical machine becomes 0 in the series parallel mode as a parameter. In the first control, if the thermal efficiency of the engine when the rotational speed of the first rotating electrical machine becomes 0 in the series parallel mode is less than the first threshold value, the rotation of the first rotating electrical machine is temporarily performed in the series parallel mode. The series mode is selected in view of the fact that when the engine is operated so that the speed becomes zero (that is, the power transmission efficiency is maximized), the thermal efficiency of the engine is considerably lower than the optimum thermal efficiency. On the other hand, if the thermal efficiency of the engine when the rotational speed of the first rotating electrical machine is 0 in the series parallel mode is greater than the first threshold value, the rotational speed of the first rotating electrical machine is 0 in the series parallel mode. The series-parallel mode is selected in view of operating the engine so that the power transmission efficiency is maximized (ie, the engine thermal efficiency is at a high level close to the optimum thermal efficiency).

  The second control is a control for selecting the travel mode using the fuel consumption rate of the engine when the rotation speed of the first rotating electrical machine becomes 0 in the series parallel mode as a parameter. The fuel consumption rate of the engine is a fuel consumption amount per unit work, and is inversely related to the thermal efficiency of the engine. Therefore, in the second control, the series mode is selected when the fuel consumption rate of the engine when the rotational speed of the first rotating electrical machine becomes 0 in the series parallel mode is larger than the second threshold value, and otherwise. Series parallel mode is selected.

  The third control is a control for selecting the travel mode using the engine torque when the rotational speed of the first rotating electrical machine becomes 0 in the series parallel mode as a parameter. The engine torque does not have a perfect one-to-one relationship with the thermal efficiency in all operating areas, but in the normal operating area where actual control is performed, the higher the engine torque, the better the thermal efficiency. is there. Therefore, in the third control, the series mode is selected when the engine torque when the rotational speed of the first rotating electrical machine is 0 in the series parallel mode is less than the third threshold value, and otherwise the series parallel is selected. A mode is selected.

  As described above, the control device according to the present disclosure does not sequentially calculate all of the plurality of efficiencies such as the engine thermal efficiency and the power conversion efficiency, but instead of the engine when the rotation speed of the first rotating electrical machine becomes 0 in the series parallel mode. The thermal efficiency or a parameter correlated with the thermal efficiency (fuel consumption rate or engine torque) is calculated, and the traveling mode is selected using the calculation result. For this reason, it is possible to select an efficient mode with a simple calculation process, compared to the case of sequentially calculating all of the plurality of efficiencies.

  According to the present invention, in a hybrid vehicle configured to be able to select either the series mode or the series parallel mode, an efficient mode can be selected with a simple arithmetic process.

It is a figure showing typically an example of the whole composition of vehicles. It is a figure which shows an example of the input / output information of a control apparatus. It is an engagement table | surface which shows the control state in each driving mode. It is an alignment chart in MG2 single drive mode. It is an alignment chart in both drive modes. It is a collinear diagram in the series mode (part 1). It is a collinear diagram in the series parallel mode (part 1). It is an alignment chart at the time of 1st speed formation in parallel mode. It is a nomograph at the time of 2nd speed formation in parallel mode. It is an alignment chart at the time of 3rd speed formation in parallel mode. It is a collinear diagram at the time of 4th speed formation in parallel mode. It is a collinear diagram when the first MG rotation speed Nm1 becomes 0 during traveling in the series parallel mode. It is an alignment chart in case 1st MG will be in a negative rotation state during driving | running | working in series parallel mode. It is a figure which shows an example of the engine operating line (transmission efficiency maximum operating line) K1 in case a power transmission efficiency becomes the maximum in series parallel mode. It is a flowchart which shows the process sequence of a control apparatus. FIG. 3 is a first diagram schematically illustrating a configuration of a driving device. It is a collinear diagram in the series mode (part 2). FIG. 3 is a diagram (part 2) schematically illustrating a configuration of a driving device. It is a collinear diagram in the series mode (part 3). FIG. 12 is a collinear diagram (part 2) in the series parallel mode.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Overall configuration of vehicle>
FIG. 1 is a diagram schematically showing an example of the overall configuration of a vehicle 1 according to the present embodiment. Vehicle 1 includes drive device 2, drive wheels 90, control device 100, and hydraulic circuit 500. The drive device 2 includes an engine 10, a first motor generator (first MG) 20, a second motor generator (second MG) 30, a first planetary gear device (power split device) 40, and a second planetary gear device 50. A clutch C1, a clutch C2, and a brake B1. The second planetary gear device 50, the clutches C1 and C2, the brake B1, and the hydraulic circuit 500 function as a switching device that switches the connection state between the engine 10 and the first planetary gear device 40, as will be described later.

  The vehicle 1 is a hybrid vehicle that travels by using at least one of the power of the engine 10, the first MG 20, and the second MG 30. The engine 10 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine. The first MG 20 and the second MG 30 are rotating electric machines (for example, permanent magnet type three-phase AC rotating electric machines) that function both as a motor and a generator. First MG 20 and second MG 30 are electrically connected to a driving battery (not shown). First MG 20 is driven by at least one of the electric power generated by second MG 30 and the electric power supplied from the driving battery. Second MG 30 is driven by at least one of the electric power generated by first MG 20 and the electric power supplied from the driving battery.

  The rotation shaft 22 is fixed to the rotor of the first MG 20, and the rotation shaft 31 is fixed to the rotor of the second MG 30. The rotating shaft 22 is disposed on the first shaft 12, and the rotating shaft 31 is disposed on the second shaft 14 parallel to the first shaft 12.

  On the first shaft 12, the first MG 20, the second planetary gear device 50, the first planetary gear device 40, the clutch C2, the clutch C1, and the engine 10 are sequentially arranged.

  Second planetary gear device 50 includes a sun gear S2, a plurality of pinion gears P2, a carrier CA2 that connects each pinion gear P2, and a ring gear R2. The second planetary gear device 50 is a single planetary gear.

  The sun gear S2 is fixed to the rotating shaft 22. The ring gear R <b> 2 is provided on the outer peripheral side of the sun gear S <b> 2 and is arranged so that the center of rotation is coaxial with the first shaft 12. The carrier CA2 is provided to be rotatable about the first shaft 12, and supports each pinion gear P2 to be rotatable. Each pinion gear P2 is disposed between the sun gear S2 and the ring gear R2, and the pinion gear P2 can revolve around the sun gear S2 and can rotate about the central axis of the pinion gear P2.

  The rotational speed of the sun gear S2, the rotational speed of the carrier CA2, and the rotational speed of the ring gear R2, as described later, are connected by a straight line on the nomograph (if any two rotational speeds are determined, the remaining rotation There is also a relationship that determines the speed).

  The first planetary gear device 40 includes a sun gear S1, a plurality of pinion gears P1, a carrier CA1 that connects each pinion gear P1, and a ring gear R1. The first planetary gear device 40 is a single planetary gear.

  The sun gear S <b> 1 is fixed to the rotation shaft 22 and is provided so as to be rotatable about the first shaft 12. For this reason, the rotating shaft 22, the sun gear S1, and the sun gear S2 rotate integrally.

  The ring gear R1 is disposed on the outer peripheral side of the sun gear S1, and is provided so as to be rotatable about the first shaft 12. A carrier CA2 is connected to the ring gear R1, and the ring gear R1 and the carrier CA2 rotate integrally.

  Each pinion gear P1 is disposed between the sun gear S1 and the ring gear R1, and meshes with the sun gear S1 and the ring gear R1. The pinion gear P1 is provided so as to be able to revolve around the sun gear S1 and is capable of rotating about the rotation center of the pinion gear P1. The carrier CA1 rotatably supports each pinion gear P1 and is rotatable about the first shaft 12.

  The rotational speed of the sun gear S1, the rotational speed of the carrier CA1, and the rotational speed of the ring gear R1, as will be described later, are related by a straight line on the nomograph (if any two rotational speeds are determined, the remaining The rotational speed is also determined).

  The brake B1 is provided on the case 25 of the driving device 2 on the outer peripheral side of the ring gear R2. The brake B1 is a hydraulic friction engagement element that can regulate the rotation of the ring gear R2. When the brake B1 is engaged, the ring gear R2 is fixed to the case 25, and the rotation of the ring gear R2 is restricted. When the brake B1 is released, the ring gear R2 is allowed to rotate.

  The clutch C2 is a hydraulic friction engagement element capable of connecting the crankshaft 21 of the engine 10 and the carrier CA1. When the clutch C2 is engaged, the crankshaft 21 and the carrier CA1 are connected and rotate integrally with each other. When the clutch C2 is released, the carrier CA1 is disconnected from the crankshaft 21.

  The clutch C1 is a hydraulic friction engagement element that can connect the rotating shaft 22 (sun gear S1 and sun gear S2) and the crankshaft 21. When the clutch C1 is engaged, the rotary shaft 22 and the crankshaft 21 are connected, and the power of the engine 10 can be directly transmitted to the first MG 20. On the other hand, when the clutch C1 is released, the crankshaft 21 of the engine 10 is disconnected from the rotating shaft 22.

  Outer peripheral teeth that mesh with the driven gear 71 are formed on the outer peripheral surface of the ring gear R1. The driven gear 71 is fixed to one end side of a counter shaft (hereinafter also referred to as “output shaft”) 70. Power from engine 10 and first MG 20 is transmitted to output shaft 70 through ring gear R1 and driven gear 71.

  A reduction gear 32 is fixed to the rotation shaft 31 of the second MG 30. The reduction gear 32 is in mesh with the driven gear 71. For this reason, the power from the second MG 30 is transmitted to the output shaft 70 through the reduction gear 32 and the driven gear 71.

  The output shaft 70 is disposed so as to be parallel to the first shaft 12 and the second shaft 14. A drive gear 72 is provided on the other end side of the output shaft 70. The drive gear 72 meshes with the diff ring gear 81 of the differential gear 80. Drive wheels 90 are connected to the differential gear 80 via a drive shaft 82. Therefore, the rotation of the output shaft 70 is transmitted to the drive wheels 90 through the differential gear 80.

  The control device 100 includes a CPU (Central Processing Unit) and a memory (not shown), and executes predetermined arithmetic processing based on information stored in the memory and information from each sensor.

<Control device input / output information>
FIG. 2 is a diagram illustrating an example of input / output information of the control device 100 illustrated in FIG. 1. The control device 100 includes a vehicle speed sensor, an accelerator opening sensor, an engine rotational speed sensor, an MG1 rotational speed sensor, an MG2 rotational speed sensor, an output shaft rotational speed sensor, a gradient sensor, a battery monitoring unit, and the like that are necessary for controlling the vehicle 1. Multiple sensors are connected. With these sensors, the control device 100 causes the speed of the vehicle 1 (hereinafter also referred to as “vehicle speed V”), the accelerator opening, the rotational speed of the engine 10 (hereinafter also referred to as “engine rotational speed Ne”), and the rotational speed of the first MG 20. (Hereinafter also referred to as “first MG rotational speed Nm1”), rotational speed of the second MG 30, rotational speed of the output shaft 70 (hereinafter also referred to as “output shaft rotational speed Nout”), road surface gradient, state of a driving battery (not shown), etc. Get information.

  The control device 100 calculates a required driving force for the vehicle 1 based on information acquired from each sensor. The control device 100 calculates output command values for the first MG 20, the second MG 30, and the engine 10 from the required driving force, and outputs the first MG 20 (current supplied to the first MG 20) so as to satisfy each output command value. The output of the second MG 30 (current supplied to the second MG 30) and the output of the engine 10 (such as the opening of the electronic throttle valve, the ignition timing, and the fuel injection amount) are controlled.

  Further, the control device 100 calculates hydraulic pressure command values PbC1, PbC2, and PbB1 for the clutches C1 and C2 and the brake B1 based on information acquired from each sensor, and outputs them to the hydraulic circuit 500 of FIG. The hydraulic circuit 500 supplies hydraulic pressures corresponding to the command values PbC1, PbC2, PbB1 to the clutches C1, C2 and the brake B1, respectively. Thereby, the state (engagement / release) of clutch C1, C2 and brake B1 is switched.

<Driving mode of vehicle 1>
The travel modes of the vehicle 1 include a motor travel mode (hereinafter referred to as “EV travel mode”) and a hybrid travel (hereinafter referred to as “HV travel”) mode.

  The EV travel mode is a mode in which the engine 10 is stopped and the vehicle 1 is traveled by at least one power of the first MG 20 and the second MG 30. In the present embodiment, the EV traveling mode includes “MG2 single drive mode” that uses the power of the second MG 30 alone and “both drive modes” that uses the power of both the first MG 20 and the second MG 30.

  The HV travel mode is a mode in which the engine 10 is operated and the vehicle 1 travels with the power of the engine 10 and at least one power of the first MG 20 and the second MG 30. In the present embodiment, the HV travel mode includes a series travel mode (hereinafter simply referred to as “series mode”), a series parallel travel mode (hereinafter also simply referred to as “series parallel mode”), and a parallel travel mode (hereinafter referred to as “series mode”). Simply referred to as “parallel mode”).

  In the series mode, all the power of the engine 10 is transmitted to the first MG 20 and converted into electric power, and the second MG 30 is driven by the electric power.

  In the series parallel mode, a part of the power of the engine 10 is mechanically transmitted to the output shaft 70, and the remaining power is transmitted to the first MG 20 and converted into electric power, and the second MG 30 is driven by the electric power.

  In the parallel mode, the power of the engine 10 is mechanically transmitted to the output shaft 70, and at least one of the first MG 20 and the second MG 30 is transmitted to the output shaft 70 as necessary.

  Note that, in any of the series mode, the series parallel mode, and the parallel mode, it is possible to generate power and / or charge the driving battery by at least one of the first MG 20 and the second MG 30 as necessary.

<< Control state during each driving mode (engagement table) >>
The control device 100 controls the control states (engagement / release) of the frictional engagement elements of the clutches C1 and C2 and the brake B1 and the driving of the engine 10, the first MG20, and the second MG30, thereby controlling the plurality of travels. Select one of the modes.

  FIG. 3 is an engagement table showing a control state of each friction engagement element in each travel mode. In FIG. 3, “C1”, “C2”, “B1”, “MG1”, and “MG2” indicate the clutch C1, the clutch C2, the brake B1, the first MG20, and the second MG30, respectively. A circle (◯) in each column of C1, C2, and B1 indicates “engagement”, and no mark indicates “release”.

  In the MG2 single drive mode, the clutch C1 is engaged and the other friction engagement elements are released. During both drive modes, the brake B1 is engaged and the other frictional engagement elements are released. During the series mode, the clutch C1 is engaged and the other friction engagement elements are released. During the series parallel mode, the clutch C2 is engaged and the other friction engagement elements are released.

  During the parallel mode, one of the first to fourth gears with different reduction ratios γ (ratio of engine rotation speed Ne to output shaft rotation speed Nout) depending on the combination of control states of the friction engagement elements. Is formed. At the time of first speed formation, the clutch C1 and the brake B1 are engaged, and the clutch C2 is released. At the time of second speed formation, the clutch C2 and the brake B1 are engaged, and the clutch C1 is released. When the third speed is established, the clutch C1 and the clutch C2 are engaged, and the brake B1 is released.

  At the time of the fourth speed formation, the clutch C2 is engaged and the other friction engagement elements are released. Further, at the time of forming the fourth speed, the current of the first MG 20 is feedback controlled so that the first MG rotation speed Nm1 is fixed to zero (hereinafter, this control is also referred to as “electric lock”).

<< Control state during each driving mode (collinear diagram) >>
FIGS. 4-11 is a figure which shows an example of the control state in each driving mode on a nomograph. 4 to 11, “Sun1” indicates the sun gear S1, “Sun2” indicates the sun gear S2, “Car1” indicates the carrier CA1, “Car2” indicates the carrier CA2, and “Ring1” indicates the ring gear R1. "Ring2" indicates the ring gear R2. “B1” indicates the brake B1, “C1” indicates the clutch C1, and “C2” indicates the clutch C2. A black circle (●) indicates “engagement” of each friction engagement element (C1, C2, B1). “ENG” indicates the engine 10, “MG1” indicates the first MG 20, “MG2” indicates the second MG 30, and “OUT” indicates the output shaft 70. “Te” represents the torque of the engine 10 (hereinafter referred to as “engine torque”), “Tm1” represents the torque of the first MG 20 (hereinafter referred to as “first MG torque”), and “Tm2” represents the torque of the second MG 30 (hereinafter referred to as “ 2nd MG torque ").

  The collinear charts shown in FIGS. 4 to 11 show the rotational speeds of the rotating elements (sun gears S1, S2, carriers CA1, CA2, ring gears R1, R2) of the first planetary gear device 40 and the second planetary gear device 50 as vertical lines. These intervals are the intervals corresponding to the gear ratios of the first planetary gear device 40 and the second planetary gear device 50, and the vertical direction of each vertical line is the rotational direction (the upper direction is the positive direction, the lower direction) Is the negative direction), and the position in the vertical direction is the rotational speed.

  FIG. 4 is an alignment chart during the MG2 single drive mode. As described above, first MG 20 is coupled to sun gears S1 and S2, and second MG 30 and output shaft 70 are coupled to ring gear R1 and carrier CA2.

  Since the clutch C1 is engaged during the MG2 single drive mode, the engine 10 is connected to the first MG 20. Further, during the MG2 single drive mode, the clutch C2 and the brake B1 are released, so that the rotation of the ring gear R2 is not restricted, and the output shaft 70 can freely rotate without being restricted by the engine rotational speed Ne. . In this state, control device 100 stops engine 10 and operates second MG 30 as a motor. Thereby, the sun gears S1 and S2 connected to the engine 10 do not rotate, while the output shaft 70 rotates according to the second MG torque Tm2.

  FIG. 5 is a collinear diagram in both drive modes. During both drive modes, the brake B1 is engaged and the clutches C1, C2 are released. In this state, control device 100 stops engine 10 and operates first MG 20 and second MG 30 as motors. Since the brake B1 is engaged and the rotation of the ring gear R2 is restricted, the first MG torque Tm1 is transmitted to the output shaft 70 with the ring gear R2 as a fulcrum. Further, the second MG torque Tm2 is also transmitted to the output shaft 70. Since the clutches C1 and C2 are released, the engine 10 is disconnected from the first planetary gear unit 40.

  FIG. 6 is a collinear diagram in the series mode. Since the clutch C1 is engaged during the series mode, the engine 10 is connected to the first MG 20. Further, since the clutch C2 and the brake B1 are released during the series mode, the rotation of the ring gear R2 is not restricted, and the engine 10 can freely rotate without being restricted by the vehicle speed V (output shaft rotational speed Nout). It becomes. In this state, control device 100 operates engine 10, operates first MG 20 as a generator, and operates second MG 30 as a motor. Thereby, the motive power of engine 10 is transmitted to first MG 20 and once converted into electric power, and second MG 30 is driven by the electric power.

  FIG. 7 is a collinear diagram in the series parallel mode. During the series parallel mode, the clutch C1 and the brake B1 are released, and the clutch C2 is engaged to connect the engine 10 to the carrier CA1. Therefore, engine 10 is connected to first MG 20 (sun gear S1) and output shaft 70 (ring gear R1) via first planetary gear unit 40. Therefore, the engine rotational speed Ne can be adjusted to an optimum value without being constrained by the vehicle speed V by appropriately adjusting the first MG rotational speed Nm1 according to the vehicle speed V (output shaft rotational speed Nout). In this state, control device 100 operates engine 10 and operates second MG 30 as a motor. At this time, control device 100 operates first MG 20 so that first MG torque Tm1 acts in the negative direction. As shown in FIG. 7, during the positive rotation of first MG 20, control device 100 causes first MG torque Tm1 to act in the negative direction by operating first MG 20 as a generator. Thus, engine torque Te is transmitted to ring gear R1 (output shaft 70) using first MG torque Tm1 as a reaction force. Therefore, in the series parallel mode, a part of the power of the engine 10 is transmitted to the first MG 20 and converted into electric power, and the rest is mechanically transmitted to the output shaft 70 using the first MG torque Tm1.

  FIG. 8 is a collinear diagram at the time of the first speed formation in the parallel mode. When the first speed is established, the clutch C1 and the brake B1 are engaged, and the clutch C2 is released. Therefore, engine 10 is connected to sun gear S1, and rotation of ring gear R2 is restricted.

  FIG. 9 is a collinear diagram when the second speed is formed in the parallel mode. When the second speed is established, the clutch C1 is released and the clutch C2 is engaged, so that the connection destination of the engine 10 is switched from the sun gear S1 to the carrier CA2 as compared with the first speed. Since the brake B1 is engaged in the same manner as in the first speed formation, the rotation of the ring gear R2 is restricted.

  FIG. 10 is a collinear diagram when the third speed is formed in the parallel mode. When the third speed is established, the clutch C1 and the clutch C2 are engaged and the engine 10 is connected to the sun gears S1 and S2 and the carrier CA1, and the brake B1 is released so that the ring gear R2 can freely rotate. Thereby, the sun gear S1, the carrier CA1, the ring gear R1, the sun gear S2, the carrier CA2, and the ring gear R2 are in a state of rotating integrally at the same rotational speed.

  FIG. 11 is a collinear diagram when the fourth speed is formed in the parallel mode. When the fourth speed is established, the clutch C2 is engaged, and the clutch C1 and the brake B1 are released. Also, the first MG 20 is electrically locked. Therefore, engine 10 is connected to carrier CA1, and the rotational speed of sun gear S1 is controlled to zero by electric lock.

  Thus, in the parallel mode, one of the first to fourth gears is formed. As a result, the reduction ratio γ is mechanically fixed to a predetermined value corresponding to each gear position. In this state, the control device 100 operates the engine 10. Therefore, the power of the engine 10 is mechanically transmitted to the output shaft 70 efficiently. In addition, as necessary, control device 100 causes at least one of first MG 20 and second MG 30 to operate as a motor with the power of the driving battery. Thereby, in addition to the power of engine 10, the power of first MG 20 and second MG 30 is mechanically transmitted to output shaft 70. In the parallel mode, at least one of the first MG 20 and the second MG 30 can be operated as a generator.

<Select driving mode>
As described above, the vehicle 1 can be switched between the EV traveling mode in which the engine 10 is stopped and the HV traveling mode in which the engine 10 is operated and the HV traveling mode is operated. For example, control device 100 is a region where the thermal efficiency of engine 10 (hereinafter also referred to as “engine thermal efficiency” or simply “thermal efficiency”) is low in a low load region where the required driving force for vehicle 1 is less than first level L1. Then, the EV traveling mode in which the engine 10 is stopped and the vehicle travels is selected. On the other hand, in the region where the required driving force is greater than the first level L1, the HV traveling mode in which the engine 10 is operated to travel is selected.

  In addition, the vehicle 1 can be switched between a series mode, a series parallel mode, and a parallel mode in the HV traveling mode. The control device 100 according to the present embodiment selects a parallel mode that excels in power performance in a high load region where the required driving force for the vehicle 1 exceeds a second level L2 that is greater than the first level L1.

  On the other hand, in the medium load region where the required driving force for vehicle 1 is included between first level L1 and second level L2, control device 100 selects either the series mode or the series parallel mode.

<Selection between series mode and series parallel mode>
As described above, control device 100 according to the present embodiment selects either the series mode or the series parallel mode in the medium load region. At this time, it is ideal to calculate all the efficiencies in the respective modes and select the more efficient one. However, as efficiency to be considered, there are a plurality of efficiency such as thermal efficiency, power transmission efficiency (the efficiency at which the power of the engine 10 and each MG 20, 30 is transmitted to the output shaft 70, including the power conversion efficiency of each MG 20, 30). Therefore, it is feared that it is practically difficult to calculate every one of the plurality of efficiencies according to the vehicle speed V and the required driving force that change every moment because the calculation load of the control device 100 becomes excessive. Is done.

  Therefore, the control device 100 according to the present embodiment does not sequentially calculate all of the plurality of efficiencies such as the thermal efficiency and the power conversion efficiency, but the thermal efficiency or the thermal efficiency when the first MG rotation speed Nm1 is 0 in the series parallel mode. The correlated parameters are calculated, and either the series mode or the series parallel mode is selected using the calculation result. For this reason, it is possible to select an efficient mode with a simple calculation process, compared to the case of sequentially calculating all of the plurality of efficiencies. Hereinafter, this point will be described in detail.

  The series mode and the series parallel mode are common in that the engine 10 is operated to run, but there is a difference in efficiency as described below.

  In the series mode, the clutch C1 is engaged and the engine 10 is connected to the first MG 20, and the clutch C2 and the brake B1 are released, so that the rotational speed of the engine 10 is adjusted to the optimum value without being restricted by the vehicle speed V. it can. Therefore, in the series mode, the engine thermal efficiency can be set to an optimum value. However, in the series mode, it is assumed that the second MG 30 is driven by the electric power generated by the first MG 20, so that a constant rate of power conversion loss occurs in each MG 20, 30. Therefore, in the series mode, the engine thermal efficiency can be optimized, while the power transmission efficiency can be reduced by the amount of power conversion loss compared to the series parallel mode.

  On the other hand, in the series parallel mode, when the first MG rotation speed Nm1 is 0, the power conversion loss of the first MG 20 is minimized, and the power transmission efficiency including the power conversion efficiency is maximized.

  FIG. 12 shows an alignment chart when the first MG rotation speed Nm1 becomes 0 during traveling in the series parallel mode. In such a state, since the power conversion loss of the first MG 20 is minimized, the power transmission efficiency is maximized.

  However, in the series-parallel mode, since the engine 10 is connected to the carrier CA1 of the first planetary gear device 40, it is difficult to optimize the thermal efficiency while maximizing the power transmission efficiency.

  Specifically, when the first MG rotation speed Nm1 (rotation speed of the sun gear S1) is set to 0 in order to maximize the power transmission efficiency, the engine rotation speed Ne (rotation speed of the carrier CA1) is set to the vehicle speed according to the nomogram. Since it is constrained by V (the rotational speed of the ring gear R1), there is a possibility that the thermal efficiency cannot be optimized.

  On the contrary, when the engine 10 is operated on the thermal efficiency optimum operation line (see FIG. 14 described later) in order to optimize the thermal efficiency, the first MG 20 becomes a negative rotation state (Nm1 <0) due to the collinear relationship, and the power transmission There is a concern that efficiency will decrease.

  FIG. 13 is a collinear diagram when the first MG 20 is in a negative rotation state during traveling in the series parallel mode. In order to transmit the power of the engine 10 to the output shaft 70 in the series parallel mode, it is necessary to apply the first MG torque Tm1 in the negative direction. However, the first MG torque Tm1 when the first MG 20 is in the negative rotation (Nm1 <0). In order to act in the negative direction, it is necessary to supply power to the first MG 20 to drive the first MG 20. Further, when the power transmitted from the engine 10 to the output shaft 70 is excessive, the second MG 30 needs to generate power in order to cause the second MG torque Tm2 to act in the negative direction. Therefore, the motive power of the engine 10 transmitted to the output shaft 70 using the first MG torque Tm1 obtained by driving the first MG 20 as a reaction force is converted into electric power by the second MG 30, and the electric power is returned to the first MG 20 to be returned to the first MG 20 Phenomenon (hereinafter referred to as “power circulation”) may occur. Since a large loss occurs due to this power circulation, the power transmission efficiency is lowered.

  In view of the difference in efficiency as described above, the control device 100 according to the present embodiment determines the engine thermal efficiency or the engine thermal efficiency when the first MG rotation speed Nm1 is 0 (the power transmission efficiency is maximized) in the series parallel mode. The correlated parameters are calculated, and either the series mode or the series parallel mode is selected using the calculation result.

  The control device 100 can calculate the engine thermal efficiency from the engine speed, the estimated engine torque value, and the fuel consumption. In order to calculate more simply, the control device 100 may store a map that defines engine thermal efficiency in advance using the engine torque and the engine speed as parameters, and calculate the engine thermal efficiency with reference to the map. it can.

  An example of a parameter having a correlation with the engine thermal efficiency is the fuel consumption rate of the engine 10. The fuel consumption rate is a fuel consumption amount per unit work, and has a reciprocal relationship with the engine thermal efficiency.

  Another example of a parameter correlated with engine thermal efficiency is engine torque. The engine torque is not completely in a one-to-one relationship with the engine thermal efficiency in all operating regions, but in the normal use region where actual control is performed, the higher the engine torque, the better the thermal efficiency. .

  Therefore, control device 100 calculates one of engine thermal efficiency, engine fuel consumption, and engine torque when first MG rotation speed Nm1 is 0 in series parallel mode, and uses the calculation results to perform series mode and series parallel. Either of the modes can be selected.

  Hereinafter, a case will be described as an example where the engine torque is calculated as a parameter having a correlation with the engine thermal efficiency, and either the series mode or the series parallel mode is selected using the calculated engine torque.

  FIG. 14 is a diagram illustrating an example of an engine operating line (hereinafter also referred to as “maximum transmission efficiency operating line”) K1 when the power transmission efficiency is maximum in the series parallel mode (that is, the first MG rotation speed Nm1 is 0). It is. Note that the maximum transmission efficiency operating line K1 rises and falls depending on the accelerator opening (user requested torque), the road surface gradient, etc., but FIG. 14 shows a flatness when the accelerator opening is constant at a predetermined opening as an example. A transmission efficiency maximum operation line K1A on the road and a transmission efficiency maximum operation line K1B on the climbing road are shown.

  In FIG. 14, the horizontal axis indicates the vehicle speed V and the engine rotation speed Ne in parallel, and the vertical axis indicates the engine torque Te. The engine torque Te on the vertical axis is a parameter having a correlation with the engine thermal efficiency.

  The maximum transmission efficiency operation line K1 is an engine operation line in which the first MG rotation speed Nm1 is 0 in the series parallel mode (see FIG. 12). The region on the low rotation high torque side (upper left) from the transmission efficiency maximum operating line K1 is an engine operation region in which the first MG rotational speed Nm1 becomes a negative value in the series parallel mode and power circulation can occur (see FIG. 13). ).

  FIG. 14 schematically shows a thermal efficiency optimum operation line K2 in addition to the maximum transmission efficiency operation line K1. The thermal efficiency optimum operating line K2 is an engine operating line that is determined in advance by the designer with reference to a line connecting operating points at which the engine thermal efficiency is maximum with respect to the engine rotational speed Ne. Therefore, when the engine 10 is operated on the thermal efficiency optimum operation line K2, the engine thermal efficiency is good. The thermal efficiency optimum operation line K2 does not change depending on the accelerator opening and the road surface gradient.

  For example, when the transmission efficiency maximum operation line K1A and the thermal efficiency optimal operation line K2 on a flat road are compared, in the region where the vehicle speed V is less than the predetermined vehicle speed V3, the thermal efficiency optimal operation line K2 rotates at a lower speed than the transmission efficiency maximum operation line K1. It exists in the region on the high torque side (upper left side), and there is a gap between them. The difference between the two decreases as the vehicle speed V increases, and the two intersect when the vehicle speed V is the predetermined vehicle speed V3. Note that the predetermined vehicle speed V3 at which both intersect on a flat road is a relatively high value (for example, a vehicle speed exceeding the time of 100 km).

  As understood from the relationship between the maximum transmission efficiency operation line K1 and the optimum thermal efficiency operation line K2 shown in FIG. 14, when the engine 10 is operated on the maximum transmission efficiency operation line K1 during the series parallel mode, the first MG rotation speed Nm1 is While the power transmission efficiency is 0 and the power transmission efficiency is maximized, the engine 10 may be operated in a region lower than the thermal efficiency optimum operation line K2, and the thermal efficiency may be lower than the optimum thermal efficiency. On the other hand, when the engine 10 is operated on the thermal efficiency optimum operating line K2 in the series parallel mode, the thermal efficiency is optimized, while the engine 10 is operated in the region of lower rotation and higher torque (upper left) than the transmission efficiency maximum operating line K1. There is a case where the vehicle is driven, and power transmission efficiency may be reduced due to power circulation.

  Therefore, control apparatus 100 according to the present embodiment has first MG rotation speed Nm1 of 0 in series parallel mode in an intermediate load region (hereinafter also referred to as “selection region”) in which one of series mode and series parallel mode should be selected. The engine torque Tec is calculated when (the power transmission efficiency is maximized).

  The control device 100 calculates the engine torque Tec as follows. First, control device 100 calculates engine rotation speed Nec from first vehicle speed V when first MG rotation speed Nm1 is 0 in the series parallel mode. When the first MG rotational speed Nm1 is 0 in the series parallel mode, the engine rotational speed Ne is determined according to the vehicle speed V as shown in the following equation (1) from the relationship of the nomograph. Therefore, the control device 100 calculates the engine rotation speed Nec corresponding to the current vehicle speed V using the following equation (1). In the equation (1), “ρ” is the gear ratio ρ of the first planetary gear device 40 (= the number of teeth of the sun gear S1 / the number of teeth of the ring gear R1). “Γ” in equation (1) is a coefficient for converting the vehicle speed V to the rotational speed of the ring gear R1, and is a value determined from the tire diameter, differential ratio, and the like.

Ne = {1 / (1 + ρ)} · V · Γ (1)
Next, the control device 100 calculates an engine torque Tec corresponding to the engine rotation speed Nec with reference to the transmission efficiency maximum operation line K1 shown in FIG. Note that, as described above, the maximum transmission efficiency operation line K1 is specified using the accelerator opening and the road surface gradient as parameters.

  Then, control device 100 determines whether or not calculated engine torque Tec is greater than threshold value Tth. Control device 100 selects the series mode when engine torque Tec is less than threshold value Tth, and selects the series parallel mode when engine torque Tec is greater than threshold value Tth.

  Here, as shown in FIG. 14, the threshold value Tth is set to a value on the low torque side by a predetermined value ΔT from the thermal efficiency optimum operation line K2. This is because the power conversion loss in the series mode is relatively large, and if the loss ratio due to the power circulation in the series parallel mode is small, it is advantageous over the power conversion loss in the series mode. That is, even if the engine torque Tec is less than the thermal efficiency optimum operating line K2 and is larger than the threshold value Tth, even if the engine 10 is operated on the thermal efficiency optimum operating line K2 in the series parallel mode, the loss due to power circulation is considerably small. Since it is less than the power conversion loss in the series mode, the total efficiency is higher when the series parallel mode is selected. Considering this point, the threshold value Tth is set to a value on the low torque side by a predetermined value ΔT from the optimum thermal efficiency operating line K2.

  FIG. 14 exemplarily shows a case where the threshold value Tth is a constant value, but the threshold value Tth is not limited to a constant value. That is, when the optimum thermal efficiency operating line K2 changes according to the engine speed Ne, it is desirable to change the threshold value Tth according to the engine speed Nec. In this case, control device 100 stores in advance a map that defines the correspondence relationship between engine speed Ne and threshold value Tth, and refers to this map to threshold value Tth corresponding to engine speed Nec. Can be calculated.

  For example, assuming that the transmission efficiency maximum operation line K1A on the flat road shown in FIG. 14 is adopted as the transmission efficiency maximum operation line K1, the control device 100 refers to the transmission efficiency maximum operation line K1A and refers to the current vehicle speed V1. An engine torque Tec corresponding to is calculated. As shown in FIG. 14, when the current vehicle speed V is the predetermined vehicle speed V1, the engine torque Tec1 corresponding to the predetermined vehicle speed V1 is less than the threshold value Tth. Select a mode. On the other hand, as shown in FIG. 14, when the current vehicle speed V is the predetermined vehicle speed V2, the engine torque Tec2 corresponding to the predetermined vehicle speed V2 is larger than the threshold value Tth, so that the control device 100 is more efficient. Choose a good series parallel mode.

  FIG. 15 is a flowchart illustrating a processing procedure when the control device 100 selects either the series mode or the series parallel mode. This flowchart is repeatedly executed at a predetermined cycle.

  In step (hereinafter, step is abbreviated as “S”) 10, control device 100 determines whether or not it is the above-mentioned selection region (medium load region in which one of series mode and series parallel mode should be selected). To do. If it is not the selected region (NO in S10), control device 100 ends the process.

  If the selected region is selected (YES in S10), control device 100 calculates engine torque Tec when first MG rotation speed Nm1 is 0 (maximum power transmission efficiency) in series parallel mode in S11. To do. Since the calculation method of engine torque Tec has already been described, detailed description will not be repeated here.

  In S12, control device 100 determines whether engine torque Tec is greater than threshold value Tth described above. Note that the threshold value Tth is a value on the lower torque side by a predetermined value ΔT than the thermal efficiency optimum operation line K2, as shown in FIG.

  If engine torque Tec is greater than threshold value Tth (YES in S12), control device 100 selects the series / parallel mode in S13.

  On the other hand, when engine torque Tec is less than threshold value Tth (NO in S12), control device 100 selects a series mode in S14.

  As described above, control device 100 according to the present embodiment does not sequentially calculate a plurality of efficiencies such as thermal efficiency and power conversion efficiency, but instead performs engine in the case where first MG rotation speed Nm1 is 0 in series parallel mode. Torque Tec (a parameter correlated with thermal efficiency) is calculated, and either the series mode or the series parallel mode is selected using the engine torque Tec as a parameter. For this reason, it is possible to select an efficient mode with a simple calculation process, compared to the case of sequentially calculating all of the plurality of efficiencies.

  As described above, the fuel consumption rate of the engine 10 may be calculated instead of the engine torque as a parameter having a correlation with the thermal efficiency. The fuel consumption rate is inversely related to the engine thermal efficiency. Therefore, the control device 100 calculates the fuel consumption rate of the engine 10 when the first MG rotation speed Nm1 is 0 in the series parallel mode, and switches the series mode when the obtained fuel consumption rate is larger than the threshold value. Select, otherwise you can select the Series Parallel mode.

  Further, as described above, the engine thermal efficiency itself may be calculated by referring to a map using the engine torque and the engine rotation speed as parameters, instead of calculating a parameter having a correlation with the engine thermal efficiency. That is, the controller 100 calculates the engine thermal efficiency when the first MG rotation speed Nm1 is 0 in the series parallel mode, selects the series mode when the obtained engine thermal efficiency is less than the threshold value, and does not You can select the series parallel mode.

Furthermore, the above-mentioned embodiment can be changed as follows, for example.
[Modification 1]
You may make it deform | transform the structure of the drive device 2 by the above-mentioned embodiment. For example, a clutch C3 capable of switching the connection state between the output shaft 70 and the first planetary gear device 40 may be added to the drive device 2 according to the above-described embodiment.

  FIG. 16 is a diagram schematically showing the configuration of the drive device 2A according to the first modification. Drive device 2A is obtained by providing driven gears 71A and 71B on output shaft 70 instead of driven gear 71 and adding clutch C3 to drive device 2 shown in FIG. Since other structures, functions, and processes are the same as those of drive device 2 shown in FIG. 1, detailed description thereof will not be repeated here.

  The driven gear 71A meshes with outer peripheral teeth formed on the outer peripheral surface of the ring gear R1. The driven gear 71A is provided with a clutch C3. The clutch C3 is configured to be switchable between a state where the driven gear 71A and the counter shaft 70 are connected and a state where the driven gear 71A and the counter shaft 70 are not connected. For example, a dog clutch can be employed as the clutch C3. When the clutch C3 is engaged, the ring gear R1 and the output shaft 70 are connected. On the other hand, when the clutch C3 is released, the output shaft 70 is disconnected from the ring gear R1.

  The driven gear 71B is fixed to the output shaft 70 and meshes with the reduction gear 32. Therefore, the power from the second MG 30 is transmitted to the output shaft 70 through the reduction gear 32 and the driven gear 71B.

  FIG. 17 is a collinear diagram in the series mode according to the first modification. During the series mode according to the first modification, the control device 100 engages the clutch C2 and the brake B1, and releases the clutch C1. Therefore, engine 10 is connected to carrier CA1 and rotation of ring gear R2 is restricted. Furthermore, control device 100 disconnects output shaft 70 and second MG 30 from ring gear R1 by releasing clutch C3.

  In this state, control device 100 operates engine 10, operates first MG 20 as a generator, and operates second MG 30 as a motor. Thereby, as is apparent from FIG. 17, the first MG rotational speed Nm1 can be made larger (increased) than the rotational speed of the engine 10. Thereby, compared with the case where 1st MG rotational speed Nm1 and the rotational speed of engine 10 correspond (refer FIG. 6), the electric power generation of 1st MG20 can be raised. Further, since the output shaft 70 and the second MG 30 are disconnected from the ring gear R1, the rotational speed of the engine 10 can be set to an optimum value without being restricted by the vehicle speed V.

[Modification 2]
In the vehicle 1 according to the above-described embodiment and modification example 1, in the HV traveling mode, it is possible to select three traveling modes of the series mode, the series parallel mode, and the parallel mode.

  However, the present disclosure is applicable to a hybrid vehicle capable of selecting two travel modes, a series mode and a series parallel mode, in the HV travel mode. Therefore, the driving device 2 according to the above-described embodiment or the driving device 2A according to Modification 1 may be simplified by removing the configuration for switching to the parallel mode.

  FIG. 18 is a diagram schematically illustrating a configuration of a drive device 2B according to the second modification. The drive device 2B is different from the drive device 2A shown in FIG. 16 in that the second planetary gear device 50 is removed and the brake B1 is disposed so as to restrict the rotation of the ring gear R1 of the first planetary gear device 40, and the clutch C1, C2 is removed and the crankshaft 21 of the engine 10 is connected to the carrier CA1 of the first planetary gear unit 40. In the drive device 2B, the series mode and the series parallel mode can be switched by switching the control state (engagement / release) of the brake B1 and the clutch C3.

  FIG. 19 is a collinear diagram in the series mode according to the second modification. In the series mode according to the second modification, the brake B1 of the drive device 2B shown in FIG. 18 is engaged, and the clutch C3 is released. Since the rotation of the ring gear R1 is restricted by the engagement of the brake B1, the power of the engine 10 is transmitted to the first MG 20 with the ring gear R2 as a fulcrum and converted into electric power. Since the output shaft 70 and the second MG 30 are disconnected from the ring gear R1 by releasing the clutch C3, the engine rotation speed Ne can be set to an optimum value without being restricted by the vehicle speed V.

  FIG. 20 is an alignment chart in the series parallel mode according to the second modification. During the series-parallel mode according to the second modification, the clutch C3 of the drive device 2B shown in FIG. 18 is engaged and the brake B1 is released. The output shaft 70 and the second MG 30 are connected to the ring gear R1 by the engagement of the clutch C3, and the rotation of the ring gear R1 is allowed by the release of the brake B1. Therefore, the connection relationship is the same as in FIG. 7 described above, and a part of the power of the engine 10 is transmitted to the first MG 20 and converted into electric power, and the rest is mechanically transmitted to the output shaft 70 using the first MG torque Tm1. The

[Modification 3]
In the above-described embodiment, hysteresis may be provided for the threshold value Tth compared with the engine torque Tec. Thereby, it is possible to prevent the traveling mode from frequently switching between the series mode and the series parallel mode with a slight change in the engine torque Tec.

  In addition, the above-described embodiments and modifications thereof may be combined as appropriate within a range where no technical contradiction occurs.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Vehicle, 2, 2A, 2B Drive apparatus, 10 Engine, 12 1st axis | shaft, 14 2nd axis | shaft, 20 1st MG, 21 Crankshaft, 22, 31 Rotating shaft, 25 Case, 30 2nd MG, 32 Reduction gear, 40 1st planetary gear unit, 50 2nd planetary gear unit, 70 output shaft, 71, 71A, 71B driven gear, 72 drive gear, 80 differential gear, 81 diff ring gear, 82 drive shaft, 90 drive wheel, 100 controller, 500 hydraulic pressure Circuit, B1 brake, C1, C2, C3 clutch, CA1, CA2 carrier, P1, P2 pinion gear, R1, R2 ring gear, S1, S2 sun gear.

Claims (1)

A hybrid vehicle,
Engine,
A first rotating electrical machine;
An output shaft connected to the drive wheel;
A second rotating electrical machine connected to the output shaft;
A planetary gear mechanism having a first element connected to the first rotating electrical machine, a second element, and a third element connected to the output shaft;
A switching device configured to be able to switch the connection state between the engine and the planetary gear mechanism to the first state or the second state;
The first state is a state in which the engine is connected to the first element, or a state in which the output shaft is disconnected from the third element while the engine is connected to the second element.
The second state is a state in which the engine is connected to the second element,
The hybrid vehicle further includes a control device configured to be able to select a travel mode of either the series mode or the series parallel mode,
The series mode is a mode in which the switching device is set to the first state, the power of the engine is transmitted to the first rotating electrical machine and converted into electric power,
In the series parallel mode, the switching device is set to the second state, and a part of the engine power is mechanically transmitted to the output shaft using the torque of the first rotating electrical machine, and the power of the engine is The remaining portion is transmitted to the first rotating electric machine or the second rotating electric machine and converted into electric power.
The control device determines which travel mode to select between the series mode and the series parallel mode by executing one of the first control, the second control, and the third control,
The first control selects the series mode when the thermal efficiency of the engine when the rotational speed of the first rotating electrical machine becomes 0 in the series parallel mode is less than a first threshold value, Control for selecting the series parallel mode when thermal efficiency is greater than the first threshold;
The second control selects the series mode when the fuel consumption rate of the engine when the rotational speed of the first rotating electrical machine is 0 in the series parallel mode is greater than a second threshold value, Control for selecting the series parallel mode when the fuel consumption rate of the engine is less than the second threshold;
The third control selects the series mode when the engine torque when the rotational speed of the first rotating electrical machine becomes 0 in the series parallel mode is less than a third threshold value, A hybrid vehicle, which is control for selecting the series parallel mode when a torque is larger than the third threshold value.

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