JP7314753B2 - Vehicle drive system - Google Patents

Description

The present invention relates to a series-parallel hybrid vehicle drive system.

An example of such a vehicle drive system is disclosed in Patent Document 1 below. In the following description of this background art, reference numerals in Patent Document 1 are quoted in parentheses.

The vehicle drive system of Patent Document 1 includes an input member (31) drivingly connected to an internal combustion engine (22), output members (63a, 63b) drivingly connected to wheels, a first rotating electric machine (MG1) and a second rotating electric machine (MG2), a power storage device (50) electrically connected to these rotating electric machines, a first transmission system (34) drivingly connecting the input member (31) and the first rotating electric machine (MG1), an input member ( a second transmission system (33, 32, 62) drivingly connecting the output members (63a, 63b) to the output members (63a, 63b); a third transmission system (36, 32, 62) drivingly connecting the second rotating electric machine (MG2) and the output members (63a, 63b); ), and a second engagement device (CL2) for connecting and disconnecting power transmission between.

The vehicle drive device of Patent Document 1 is a drive device for a so-called series-parallel hybrid vehicle. In the vehicle drive system of Patent Document 1, one of the five running modes is selected by controlling the states of engagement of the first engagement device (CL1) and the second engagement device (CL2) based on the required torque and the like, and by controlling the operations of the first rotating electrical machine (MG1), the second rotating electrical machine (MG2), and the internal combustion engine (22).

JP 2016-88385 A

In the vehicle drive system of Patent Document 1, as shown in FIG. 3 of Patent Document 1, the two-motor EV mode is selected only when the vehicle runs at low speed and high torque. The 2-motor EV mode is a mode in which the driving force of both the first rotating electric machine (MG1) and the second rotating electric machine (MG2) is transmitted to the output members (63a, 63b), and the first rotating electric machine (MG1) is in the power running state in addition to the second rotating electric machine (MG2).

On the other hand, in running modes other than the two-motor EV mode, the first rotating electric machine (MG1) does not enter the power running state. That is, in running modes other than the two-motor EV mode, the first rotating electric machine (MG1) is in the power generation state or the idling state (the state in which it does not output driving force), and the driving forces of the internal combustion engine (22) and the second rotating electric machine (MG2) are used for running the vehicle. In such a vehicle drive system, it is necessary to ensure a sufficient output of the second rotating electric machine (MG2) in order to ensure wheel driving force especially in a high speed range. Therefore, there is a problem that the size of the second rotary electric machine (MG2) tends to increase, which in turn tends to increase the size of the vehicle drive device.

Therefore, it is desirable to suppress the increase in size of such a series-parallel type hybrid vehicle drive device.

In view of the above, the characteristic configuration of the vehicle drive system is as follows.
an input member drivingly connected to an internal combustion engine;
an output member drivingly connected to the wheel;
a first rotating electrical machine and a second rotating electrical machine;
a power storage device electrically connected to the first rotating electrical machine and the second rotating electrical machine and configured to be charged from outside the vehicle;
a first transmission system drivingly connecting the input member and the first rotating electrical machine;
a second transmission system drivingly connecting the first rotating electric machine and the output member;
a third transmission system drivingly connecting the second rotating electric machine and the output member;
a first engagement device for connecting and disconnecting power transmission in the first transmission system;
a second engagement device that connects and disconnects power transmission in the second transmission system,
The point is that the sum of the output capability of the first rotating electrical machine and the output capability of the second rotating electrical machine is equal to or less than the output of the power storage device.

According to this characteristic configuration, electric power can be simultaneously supplied from the power storage device to both the first rotating electric machine and the second rotating electric machine, and both of them can be simultaneously powered with an output corresponding to their output capability. As a result, both the first rotating electric machine and the second rotating electric machine can be powered in various vehicle speed ranges, and the driving force thereof can be used for running the vehicle. Therefore, it is possible to reduce the need to ensure a large output of the second rotating electric machine, and to suppress the enlargement of the second rotating electric machine. As a result, it is possible to suppress an increase in the size of the drive device for a series-parallel type hybrid vehicle.

1 is a skeleton diagram of a vehicle drive system according to an embodiment; 1 is a control block diagram of a vehicle drive system according to an embodiment; FIG. 4 is a diagram showing an example of performance of an internal combustion engine, a first rotating electrical machine, a second rotating electrical machine, and a power storage device; A diagram showing an example of a control map for determining the driving mode A diagram showing operating states of the first engagement device, the second engagement device, the first rotating electrical machine, the second rotating electrical machine, and the internal combustion engine in each driving mode.

A vehicle drive system 100 according to an embodiment will be described below with reference to the drawings. As shown in FIG. 1, the vehicle drive device 100 is a device for driving a series-parallel type plug-in hybrid vehicle that uses an internal combustion engine EG, a first rotating electrical machine MG1 and a second rotating electrical machine MG2 as driving force sources for wheels W. The vehicle drive device 100 includes an input member 1, an output member 2, a first rotating electrical machine MG1, a second rotating electrical machine MG2, a first engagement device CL1, and a second engagement device CL2. In this embodiment, the vehicle drive device 100 further includes a counter gear mechanism 3, a differential gear mechanism 4, a first gear G1, a second gear G2, a third gear G3, a fourth gear G4, and a fifth gear G.

In this embodiment, the input member 1, the first gear G1, and the fourth gear G4 are each arranged on the first axis X1 as the rotation axis. Each of the first rotary electric machine MG1, the second gear G2, and the third gear G3 is arranged on the second axis X2 as the rotation axis. Further, the counter gear mechanism 3 is arranged on the third axis X3 as its rotation axis. Each of the second rotating electric machine MG2 and the fifth gear G is arranged on the fourth axis X4 as the rotation axis. Also, the output member 2 and the differential gear mechanism 4 are arranged on the fifth axis X5 as their rotation axis. The first axis X1 to the fifth axis X5 are virtual axes different from each other, and are arranged in parallel with each other.

In the following description, the direction parallel to the axes X1 to X5 is defined as the "axial direction L" of the vehicle drive device 100. As shown in FIG. In the axial direction L, the side on which the first rotary electric machine MG1 is arranged with respect to the input member 1 is defined as "axial first side L1", and the opposite side is defined as "axial second side L2". A direction perpendicular to each of the axes X1 to X5 is defined as a "radial direction R" with respect to each axis. In addition, when it is not necessary to distinguish which axis should be used as a reference, or when it is clear which axis should be used as a reference, it may simply be described as “radial direction R”.

The input member 1 is drivingly connected to the internal combustion engine EG. In this embodiment, the input member 1 is drivingly connected to an output shaft (such as a crankshaft) of the internal combustion engine EG via the damper device DP. The internal combustion engine EG is a prime mover (gasoline engine, diesel engine, etc.) that is driven by combustion of fuel to take out power. The damper device DP is a device that dampens fluctuations in transmitted torque. In this embodiment, the damper device DP is provided with a torque limiter that limits transmission of driving force to the internal combustion engine EG when excessive torque is input from the output side.

Here, in the present application, "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit driving force, and includes a state in which the two rotating elements are connected so as to rotate integrally, or a state in which the two rotating elements are connected so as to be able to transmit driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at different speeds, such as shafts, gear mechanisms, belts, and chains. The transmission member may include an engagement device for selectively transmitting rotation and driving force, such as a friction engagement device and a mesh type engagement device.

The output member 2 is drivingly connected to the wheels W. As shown in FIG. In this embodiment, the output member 2 has a pair of output shafts 21 . Each of the pair of output shafts 21 is drivingly connected to the wheels W. As shown in FIG.

The first rotating electrical machine MG1 includes a first stator St1 fixed to a non-rotating member (for example, a case housing the first rotating electrical machine MG1 and the second rotating electrical machine MG2, etc.), and a first rotor Ro1 rotatably supported with respect to the first stator St1. In this embodiment, the first rotor Ro1 is arranged inside in the radial direction R with respect to the first stator St1. A first rotor shaft Ros1 extending along the axial direction L is coupled to the first rotor Ro1 so as to rotate integrally therewith.

The first gear G1 and the second gear G2 are in mesh with each other. In this embodiment, the first gear G1 is connected to the input member 1 via the first engagement device CL1. Further, in this embodiment, the second gear G2 is coupled to rotate integrally with the first rotor shaft Ros1. Thus, in the present embodiment, the first gear G1 and the second gear G2 constitute a "first transmission system T1" that drives and connects the input member 1 and the first rotary electric machine MG1.

The first engagement device CL1 is an engagement device that connects and disconnects power transmission in the first transmission system T1. In this embodiment, the first engagement device CL1 connects and disconnects power transmission between the input member 1 and the first gear G1. Further, in the present embodiment, the first engagement device CL1 is a mesh engagement device (dog clutch) configured to be switchable between an engaged state and a released state by an actuator such as a solenoid or an electric motor. When the first engagement device CL1 is in the engaged state, power is transmitted between the input member 1 and the first gear G1. On the other hand, when the first engagement device CL1 is in the released state, power transmission between the input member 1 and the first gear G1 is interrupted.

The third gear G3 and the fourth gear G4 are in mesh with each other. In this embodiment, the third gear G3 is coupled to the first rotor shaft Ros1 via the second engagement device CL2. Further, in this embodiment, the fourth gear G4 is supported so as to be relatively rotatable with respect to the input member 1. As shown in FIG.

The counter gear mechanism 3 has a counter input gear 31 and a counter output gear 32 .

A counter input gear 31 is an input element of the counter gear mechanism 3 . The counter input gear 31 meshes with the fourth gear G4. A counter output gear 32 is an output element of the counter gear mechanism 3 . The counter output gear 32 is connected to rotate integrally with the counter input gear 31 . In this embodiment, the counter output gear 32 is connected to the counter input gear 31 via a counter shaft 33 extending along the axial direction L. As shown in FIG. In the illustrated example, the counter output gear 32 is arranged on the first side L1 in the axial direction from the counter input gear 31 . Further, in the illustrated example, the counter output gear 32 is formed to have a smaller diameter than the counter input gear 31 .

The differential gear mechanism 4 has a differential input gear 41 . A differential input gear 41 is an input element of the differential gear mechanism 4 . The differential input gear 41 meshes with the counter output gear 32 of the counter gear mechanism 3 . In FIG. 1, the dashed line connecting the differential input gear 41 and the counter output gear 32 indicates that those gears are in mesh with each other.

In this embodiment, the differential gear mechanism 4 is a bevel gear type differential gear mechanism. Specifically, the differential gear mechanism 4 includes a hollow differential case, a pinion shaft supported to rotate integrally with the differential case, a pair of pinion gears rotatably supported with respect to the pinion shaft, and a pair of side gears meshing with the pair of pinion gears and functioning as distribution output elements. The differential case accommodates a pinion shaft, a pair of pinion gears, and a pair of side gears. In this embodiment, the differential input gear 41 is connected to the differential case so as to protrude outward in the radial direction R of the differential case. An output shaft 21 of the output member 2 is connected to each of the pair of side gears so as to be integrally rotatable. Thus, the differential gear mechanism 4 distributes the rotation of the differential input gear 41 to the pair of output shafts 21 .

In this embodiment, the third gear G3, the fourth gear G4, the counter gear mechanism 3, and the differential gear mechanism 4 constitute a “second transmission system T2” that drives and connects the first rotary electric machine MG1 and the output member 2.

The second engagement device CL2 is an engagement device that connects and disconnects power transmission in the second transmission system T2. In this embodiment, the second engagement device CL2 connects and disconnects power transmission between the first rotor shaft Ros1 and the third gear G3. Further, in the present embodiment, the second engagement device CL2 is a meshing engagement device (dog clutch) configured to be switchable between an engaged state and a released state by an actuator such as a solenoid or an electric motor. When the second engagement device CL2 is in the engaged state, power is transmitted between the first rotor shaft Ros1 and the third gear G3. On the other hand, when the second engagement device CL2 is in the released state, power transmission between the first rotor shaft Ros1 and the third gear G3 is cut off.

The second rotating electrical machine MG2 includes a second stator St2 fixed to a non-rotating member (for example, a case housing the first rotating electrical machine MG1 and the second rotating electrical machine MG2, etc.), and a second rotor Ro2 rotatably supported with respect to the second stator St2. In this embodiment, the second rotor Ro2 is arranged inside in the radial direction R with respect to the second stator St2. A second rotor shaft Ros2 extending along the axial direction L is coupled to the second rotor Ro2 so as to rotate integrally therewith.

The fifth gear G5 is connected to rotate integrally with the second rotor shaft Ros2. The fifth gear G5 meshes with the counter input gear 31 of the counter gear mechanism 3 at a different position in the circumferential direction of the counter input gear 31 from the fourth gear G4.

In this embodiment, the fifth gear G5, the counter gear mechanism 3, and the differential gear mechanism 4 constitute a “third transmission system T3” that drives and connects the second rotating electric machine MG2 and the output member 2. In this embodiment, the counter gear mechanism 3 and the differential gear mechanism 4 are shared by the second transmission system T2 and the third transmission system T3.

In the present embodiment, the power transmission path from the internal combustion engine EG to the output member 2 includes the power transmission path from the first rotary electric machine MG1 to the output member 2 . Therefore, a “rotating member” that rotates integrally with the rotor (first rotor Ro1) of the first rotating electric machine MG1 is arranged in the power transmission path from the internal combustion engine EG to the output member 2 . In this embodiment, this "rotating member" is the first rotor shaft Ros1 and the second gear G2.

As shown in FIG. 2, the vehicle drive device 100 includes a power storage device ST electrically connected to the first rotating electric machine MG1 and the second rotating electric machine MG2. The power storage device ST is a device such as a battery or a capacitor that can store electric power, and is configured to be chargeable from outside the vehicle via an external charging mechanism EC provided in the vehicle. In this example, the power storage device ST is electrically connected to the first rotating electrical machine MG1 and the second rotating electrical machine MG2 via inverters INV1 and INV2 that perform DC/AC conversion.

Each of the first rotating electrical machine MG1 and the second rotating electrical machine MG2 has a function as a motor (electric motor) that receives power supply and generates power, and a function as a generator (generator) that receives power supply and generates power. In other words, the first rotary electric machine MG1 is configured to be powered by being supplied with power from the power storage device ST via the first inverter INV1, or to store electric power generated by the driving force of the internal combustion engine EG, the inertial force of the vehicle, or the like in the power storage device ST via the first inverter INV1. Further, the second rotating electric machine MG2 is configured such that it can be powered by being supplied with electric power from the power storage device ST via the second inverter INV2, or can store electric power generated by the driving force of the internal combustion engine EG, the inertial force of the vehicle, or the like in the power storage device ST via the second inverter INV2.

FIG. 3 shows an example of output values of the first rotating electrical machine MG1, the second rotating electrical machine MG2, and the power storage device ST. As shown in FIG. 3, the sum of the output capability of the first rotating electrical machine MG1 and the output capability of the second rotating electrical machine MG2 is equal to or less than the output of the power storage device ST. In this example, the "output capacity" of the first rotating electric machine MG1 and the second rotating electric machine MG2 is designed as their "maximum output". Therefore, in FIG. 3, the "outputs" of the internal combustion engine EG, the first rotating electrical machine MG1, and the second rotating electrical machine MG2 refer to their "maximum outputs." Here, the “maximum output” of the rotating electric machine is the maximum value of the output that the rotating electric machine can output at least temporarily.

In this embodiment, the sum of the output capability of the first rotating electrical machine MG1 and the output capability of the second rotating electrical machine MG2 is equivalent to the output of the power storage device ST. In the illustrated example, the maximum output of the first rotating electrical machine MG1 and the maximum output of the second rotating electrical machine MG2 are both 50 kW, and the output of the power storage device ST is 100 kW. Therefore, in the illustrated example, the total of the maximum output of the first rotating electrical machine MG1 and the maximum output of the second rotating electrical machine MG2 is the same as the output of the power storage device ST. Here, with respect to two numerical values, "equivalent" means that these numerical values are completely the same, and the range in which these numerical values can be regarded as identical is a concept that includes a range (for example, a range within ±10% of the reference value) set in advance according to the characteristics of each numerical value. Therefore, for example, even if there is a difference within the error range of each numerical value caused by the manufacturing error of the first rotating electric machine MG1, the second rotating electric machine MG2, and the power storage device ST, it can be regarded as "equivalent".

Further, the rated rotation speed of the first rotary electric machine MG1 is equal to or higher than a value calculated by multiplying the rotation speed of the output member 2 at the maximum vehicle speed Vm (see FIG. 4) by the gear ratio of the second transmission system T2. Here, the “rated rotation speed” is the upper limit of the rotation speed at which the target rotary electric machine (here, the first rotary electric machine MG1) can be stably and continuously driven for a specified time (for example, 1 hour). Therefore, the first rotary electric machine MG1 can stably and continuously drive even when the vehicle in which the vehicle drive device 100 is mounted runs at the maximum vehicle speed Vm for a specified time. Therefore, in the entire vehicle speed range, the first rotating electric machine MG1 can be powered and the driving force thereof can be used for running the vehicle. Similarly, the second rotating electric machine MG2 is also configured to be stably continuously driven even when the vehicle runs at the maximum vehicle speed Vm for a specified time. In other words, the rated rotation speed of the second rotating electrical machine MG2 is equal to or higher than the value calculated by multiplying the rotation speed of the output member 2 at the maximum vehicle speed Vm by the gear ratio of the third transmission system T3. In the example shown in FIG. 3, both the maximum rotation speed (maximum rotation speed) of the first rotary electric machine MG1 and the maximum rotation speed (maximum rotation speed) of the second rotary electric machine MG2 are 17000 rpm. Naturally, the rated rotation speed of the first rotating electrical machine MG1 and the rated rotating speed of the second rotating electrical machine MG2 are each set to a smaller value.

As shown in FIG. 3, in the present embodiment, the output capability of the first rotary electric machine MG1 and the output capability of the internal combustion engine EG are equivalent. In the illustrated example, the maximum output of the first rotary electric machine MG1 is 50 kW, and the maximum output of the internal combustion engine EG is also 50 kW. Therefore, in the illustrated example, the maximum output of the first rotary electric machine MG1 and the maximum output of the internal combustion engine EG are the same.

Further, in the present embodiment, the output capability of the first rotating electrical machine MG1 and the output capability of the second rotating electrical machine MG2 are equivalent. In the illustrated example, the maximum output of the first rotating electrical machine MG1 is 50 kW, and the maximum output of the second rotating electrical machine MG2 is also 50 kW. Therefore, in the illustrated example, the maximum output of the first rotating electrical machine MG1 and the maximum output of the second rotating electrical machine MG2 are the same.

Further, in the present embodiment, the maximum torque of the first rotating electrical machine MG1 is smaller than the maximum torque of the second rotating electrical machine MG2. The maximum torque of the internal combustion engine EG is greater than the maximum torque of the first rotating electrical machine MG1 and smaller than the maximum torque of the second rotating electrical machine MG2. In the example shown in FIG. 3, the maximum torque of the internal combustion engine EG is 100 Nm, the maximum torque of the first rotating electrical machine MG1 is 50 Nm, and the maximum torque of the second rotating electrical machine MG2 is 200 Nm.

As shown in FIG. 2, the vehicle drive system 100 includes a control device 10 for controlling each part of the vehicle in which the vehicle drive system 100 is mounted. In the present embodiment, the control device 10 includes a main control section 11, an internal combustion engine control section 12 that controls the internal combustion engine EG, a first rotating electrical machine control section 13 that controls the first rotating electrical machine MG1, a second rotating electrical machine control section 14 that controls the second rotating electrical machine MG2, and an engagement control section 15 that controls the state of engagement of the first engagement device CL1 and the second engagement device CL2.

Each of the control units 11 to 15 of the control device 10 includes an arithmetic processing unit such as a CPU as a core member, and has a storage device such as a RAM (random access memory) capable of reading and writing data from the arithmetic processing unit, and a ROM (read only memory) capable of reading data from the arithmetic processing unit. Further, each of the control units 11 to 15 has software (program) stored in a storage device, hardware such as an arithmetic circuit provided separately, or both. The control units 11 to 15 are configured to communicate with each other, share various information such as sensor detection information and control parameters, and perform cooperative control.

The main control unit 11 outputs commands to the internal combustion engine control unit 12, the first rotating electric machine control unit 13, the second rotating electric machine control unit 14, and the engagement control unit 15, respectively, to control the devices that each control unit is in charge of. The internal combustion engine control unit 12 controls the internal combustion engine EG so that the internal combustion engine EG outputs the target torque commanded by the main control unit 11 or achieves the target rotational speed commanded by the main control unit 11. The first rotating electrical machine control unit 13 controls the first inverter INV1 connected to the first rotating electrical machine MG1 so that the first rotating electrical machine MG1 outputs the target torque commanded by the main control unit 11 or achieves the target rotation speed commanded by the main control unit 11. The second rotating electrical machine control unit 14 controls the second inverter INV2 connected to the second rotating electrical machine MG2 so that the second rotating electrical machine MG2 outputs the target torque commanded by the main control unit 11 or achieves the target rotational speed commanded by the main control unit 11. The engagement control unit 15 controls actuators (not shown) for operating the first engagement device CL1 and the second engagement device CL2 so that the first engagement device CL1 and the second engagement device CL2 are in the engaged state instructed by the main control unit 11.

Further, the main control unit 11 is configured to be able to acquire information from sensors provided in each part of the vehicle in order to acquire information of each part of the vehicle in which the vehicle drive device 100 is mounted. In this embodiment, the main control unit 11 is configured to be able to acquire information from the SOC sensor Se1, the vehicle speed sensor Se2, the accelerator operation amount sensor Se3, the brake operation amount sensor Se4, and the shift position sensor Se5.

SOC sensor Se1 is a sensor for detecting the state of power storage device ST. The SOC sensor Se1 is composed of, for example, a voltage sensor, a current sensor, or the like. The main control unit 11 calculates the state of charge (SOC) of the power storage device ST based on information such as the voltage value and the current value output from the SOC sensor Se1.

Vehicle speed sensor Se2 is a sensor for detecting the traveling speed (vehicle speed) of the vehicle in which vehicle drive device 100 is mounted. In this embodiment, the vehicle speed sensor Se<b>2 is a sensor for detecting the rotation speed of the output member 2 . The main control unit 11 calculates the rotation speed (angular velocity) of the output member 2 based on the rotation speed information output from the vehicle speed sensor Se2. Since the rotation speed of the output member 2 is proportional to the vehicle speed, the main control section 11 calculates the vehicle speed based on the detection signal of the vehicle speed sensor Se2.

Accelerator operation amount sensor Se3 is a sensor for detecting the amount of operation by the driver of an accelerator pedal provided in the vehicle in which vehicle drive system 100 is mounted. The main control unit 11 calculates the amount of operation of the accelerator pedal by the driver based on the detection signal of the accelerator operation amount sensor Se3.

Brake operation amount sensor Se4 is a sensor for detecting the amount of operation by the driver of a brake pedal provided in the vehicle in which vehicle drive system 100 is mounted. The main control unit 11 calculates the amount of operation of the brake pedal by the driver based on the detection signal of the brake operation amount sensor Se4.

Shift position sensor Se5 is a sensor for detecting a selected position (shift position) of a shift lever operated by the driver of the vehicle in which vehicle drive system 100 is mounted. The main control section 11 calculates the shift position based on the detection signal of the shift position sensor Se5. The shift lever is configured to select a parking range (P range), a reverse travel range (R range), a neutral range (N range), a forward travel range (D range), and the like.

The main control unit 11 selects a plurality of driving modes, which will be described later, based on the information from the sensors Se1 to Se5. Then, the main control unit 11 controls the engagement state of the first engagement device CL1 and the second engagement device CL2 according to the selected travel mode via the engagement control unit 15, thereby switching to the selected travel mode. Furthermore, the main control unit 11 cooperatively controls the operating states of the internal combustion engine EG, the first rotating electric machine MG1, and the second rotating electric machine MG2 via the internal combustion engine control unit 12, the first rotating electric machine control unit 13, and the second rotating electric machine control unit 14, thereby enabling the vehicle to run appropriately according to the selected running mode.

The main control unit 11 stores a control map that is referenced to determine the driving mode according to the vehicle speed and required driving force. An example of this control map is shown in FIG. As shown in FIG. 4, the running modes include a 1-motor EV mode, a 2-motor EV mode, a parallel mode, and a series mode. In FIG. 4, the horizontal axis is the vehicle speed [km/h], and the vertical axis is the required driving force [N]. Here, the required driving force is a value representing the driving force required of the vehicle by the driver, and is calculated by the main control unit 11 based on information from the accelerator operation amount sensor Se3 and the brake operation amount sensor Se4. Then, the main control unit 11 controls the operating states of the internal combustion engine EG, the first rotating electric machine MG1, and the second rotating electric machine MG2 via the internal combustion engine control unit 12, the first rotating electric machine control unit 13, and the second rotating electric machine control unit 14 so that the driving force (torque) corresponding to the required driving force is transmitted to the wheels W.

As shown in FIG. 4, the 1-motor EV mode, the series mode, and the 2-motor EV mode are set to handle the entire vehicle speed range, and the parallel mode is set to handle the vehicle speed range from the specified vehicle speed to the maximum vehicle speed Vm. In addition, the 2-motor EV mode is set so as to handle a region of higher required driving force than those in the 1-motor EV mode and the series mode at the same vehicle speed. The parallel mode is set so as to handle a region of higher required driving force than in the two-motor EV mode at the same vehicle speed as in the two-motor EV mode. Here, the 1-motor EV mode and the 2-motor EV mode are modes that are selected only when the state of charge (SOC) of the power storage device ST is equal to or higher than a specified value. Therefore, even if the vehicle speed and the required driving force are the same, the series mode or parallel mode is selected when the state of charge (SOC) of power storage device ST is less than the specified value. Note that the prescribed value of the charge amount may be a fixed value, or may be a variable value that changes according to the temperature of the power storage device ST or the like. In any case, the specified value of the charge amount is set in advance according to vehicle characteristics, usage conditions, and the like.

FIG. 5 shows operating states of the first engagement device CL1, the second engagement device CL2, the first rotary electric machine MG1, the second rotary electric machine MG2, and the internal combustion engine EG in each running mode. FIG. 5 shows the operating state of each part when the vehicle is in an acceleration state and a constant speed cruising state while the vehicle is traveling forward. In the columns of the first engaging device CL1 and the second engaging device CL2 in FIG. 5, "○" indicates that the target engaging device is in the engaged state, "Δ" indicates that the target engaging device is in either the engaged state or the released state, and blank indicates that the target engaging device is in the released state.

As shown in FIG. 5, the 1-motor EV mode is realized by controlling at least the second engagement device CL2 out of the first engagement device CL1 and the second engagement device CL2 to be in the released state. Therefore, in the 1-motor EV mode, transmission of driving force between the internal combustion engine EG and the output member 2 is blocked, and transmission of driving force between the first rotating electric machine MG1 and the output member 2 is blocked. Since no engagement device is provided in the power transmission path between the second rotating electric machine MG2 and the output member 2, transmission of driving force between them is always allowed regardless of the running mode. In the 1-motor EV mode, both the first rotating electrical machine MG1 and the internal combustion engine EG are controlled to be in a stopped state, and the second rotating electrical machine MG2 is controlled to be in a power running state upon receiving power supply from the power storage device ST. In this manner, the 1-motor EV mode is a driving mode in which the vehicle travels by transmitting only the driving force of the second rotating electric machine MG2 out of the first rotating electric machine MG1, the second rotating electric machine MG2, and the internal combustion engine EG to the output member 2. In the one-motor EV mode, it is preferable that the first engagement device CL1 is in the engaged state. This is because when shifting from the 1-motor EV mode to a mode in which the internal combustion engine EG is driven (parallel mode, series mode), the engagement operation of the first engagement device CL1 becomes unnecessary, and responsiveness can be improved.

The two-motor EV mode is realized by controlling the first engagement device CL1 to be in the released state and controlling the second engagement device CL2 to be in the engaged state. Therefore, in the two-motor EV mode, transmission of driving force between the internal combustion engine EG and the output member 2 is cut off. On the other hand, transmission of driving force between the first rotating electric machine MG1 and the output member 2 is allowed. In the 2-motor EV mode, the internal combustion engine EG is controlled to be in a stopped state, and both the first rotating electric machine MG1 and the second rotating electric machine MG2 are controlled to be in a power running state by receiving electric power supply from the power storage device ST. Thus, the 2-motor EV mode is a driving mode in which the driving force of the two rotating electric machines MG1 and MG2 out of the first rotating electric machine MG1, the second rotating electric machine MG2, and the internal combustion engine EG is transmitted to the output member 2 to drive the vehicle.

The parallel mode is realized by controlling both the first engagement device CL1 and the second engagement device CL2 to be in the engaged state. Therefore, in the parallel mode, transmission of driving force between the internal combustion engine EG and the output member 2 is allowed, and transmission of driving force between the first rotating electric machine MG1 and the output member 2 is allowed. In the parallel mode, the internal combustion engine EG is controlled to be driven. Further, each of the first rotary electric machine MG1 and the second rotary electric machine MG2 is controlled to either the power running state or the power generation state according to the amount of operation of the accelerator pedal and the brake pedal by the driver and the amount of charge of the power storage device ST. In this way, in the parallel mode, the vehicle is driven by transmitting all of the driving force of the first rotating electrical machine MG1, the second rotating electrical machine MG2, and the internal combustion engine EG to the output member 2, and the vehicle is driven by transmitting the driving force of the internal combustion engine EG to the output member 2, and at least one of the first rotating electrical machine MG1 and the second rotating electrical machine MG2 generates power using a part of the driving force of the internal combustion engine EG or the inertial force of the vehicle to charge the power storage device ST. It is running mode. In the constant-speed cruising state in the parallel mode, the first rotating electric machine MG1 and the second rotating electric machine MG2 may be in an idle state in which neither power running nor power generation is performed.

The series mode is realized by controlling the first engagement device CL1 to be in the engaged state and controlling the second engagement device CL2 to be in the released state. Therefore, in the series mode, transmission of driving force between the internal combustion engine EG and the first rotary electric machine MG1 is allowed. On the other hand, transmission of driving force between the internal combustion engine EG and the first rotating electric machine MG1 and the output member 2 is cut off. In the series mode, the internal combustion engine EG is controlled to be driven. Further, the first rotating electrical machine MG1 is controlled to generate power by the driving force of the internal combustion engine EG and to enter a power generation state in which power is supplied to at least one of the second rotating electrical machine MG2 and the power storage device ST. Then, the second rotating electrical machine MG2 is controlled to the power running state by receiving power supply from at least one of the first rotating electrical machine MG1 in the power generating state and the power storage device ST. In this manner, the series mode is a running mode in which the vehicle travels by transmitting the driving force of the second rotating electric machine MG2 to the output member 2 while causing the first rotating electric machine MG1 to generate power using the driving force of the internal combustion engine EG.

[Other embodiments]
(1) In the above example, the case where the "output capacity" of the first rotating electric machine MG1 and the second rotating electric machine MG2 is designed as their "maximum output" has been described. However, without being limited to this, the "output capacity" of the first rotating electrical machine MG1 and the second rotating electrical machine MG2 may be designed as their "rated output". Here, the "rated output" of the rotating electrical machine is the upper limit of the output at which the rotating electrical machine can be stably and continuously driven for a specified period of time (for example, one hour).

(2) In the above-described embodiment, an example is described in which the total output capability of the first rotating electrical machine MG1 and the output capability of the second rotating electrical machine MG2 is equal to the output of the power storage device ST. However, without being limited to such a configuration, a configuration may be adopted in which the total of the output capability of the first rotating electrical machine MG1 and the output capability of the second rotating electrical machine MG2 is smaller than the output of the power storage device ST. In this case, a configuration in which the sum of the input capability of the first rotating electrical machine MG1 and the input capability of the second rotating electrical machine MG2 is equivalent to the output of the power storage device ST is also suitable. Here, the "input capacity" of the rotating electrical machine may be, for example, the "maximum input" of the rotating electrical machine, or the "rated input" of the rotating electrical machine. The “maximum input” of a rotating electrical machine is the electric power input to the rotating electrical machine in a state where the output of the rotating electrical machine is the maximum output. The "rated input" of a rotating electrical machine is the power input to the rotating electrical machine when the output of the rotating electrical machine is the rated output. In general, the output of a rotating electric machine is smaller than the input power. Therefore, with this configuration, the total of the output capability of the first rotating electrical machine MG1 and the output capability of the second rotating electrical machine MG2 becomes smaller than the output of the power storage device ST.

(3) In the above embodiment, the configuration in which the output capability of the first rotary electric machine MG1 and the output capability of the internal combustion engine EG are the same has been described as an example. However, without being limited to such a configuration, for example, a configuration in which the output capability of the first rotary electric machine MG1 is smaller than the output capability of the internal combustion engine EG may be employed.

(4) In the above embodiment, the configuration in which the output capability of the first rotating electrical machine MG1 and the output capability of the second rotating electrical machine MG2 are equivalent has been described as an example. However, without being limited to such a configuration, the output capability of the first rotating electrical machine MG1 may be smaller or larger than the output capability of the second rotating electrical machine MG2.

(5) In the above-described embodiment, the configuration in which the rotating member (the first rotor shaft Ros1 and the second gear G2) that rotates integrally with the rotor (the first rotor Ro1) of the first rotating electric machine MG1 is arranged in the power transmission path from the internal combustion engine EG to the output member 2 has been described as an example. However, without being limited to such a configuration, for example, a configuration in which the input member 1 is arranged in the power transmission path from the first rotary electric machine MG1 to the output member 2 may be employed.

(6) In the above embodiment, the configuration in which each of the first engagement device CL1 and the second engagement device CL2 is a meshing engagement device has been described as an example. However, without being limited to such a configuration, at least one of the first engagement device CL1 and the second engagement device CL2 may be, for example, a hydraulic friction engagement device in which the state of engagement between the friction members is controlled by hydraulic pressure.

(7) It should be noted that the configurations disclosed in the respective embodiments described above can be applied in combination with configurations disclosed in other embodiments as long as there is no contradiction. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate without departing from the scope of the present disclosure.

[Overview of the above embodiment]
Below, the outline|summary of the vehicle drive device (100) demonstrated above is demonstrated.

The vehicle drive device (100) includes:
an input member (1) drivingly connected to an internal combustion engine (EG);
an output member (2) drivingly connected to the wheel (W);
a first rotating electrical machine (MG1) and a second rotating electrical machine (MG2);
a power storage device (ST) electrically connected to the first rotating electrical machine (MG1) and the second rotating electrical machine (MG2) and configured to be chargeable from outside the vehicle;
a first transmission system (T1) drivingly connecting the input member (1) and the first rotating electric machine (MG1);
a second transmission system (T2) drivingly connecting the first rotating electrical machine (MG1) and the output member (2);
a third transmission system (T3) drivingly connecting the second rotating electric machine (MG2) and the output member (2);
a first engagement device (CL1) for connecting and disconnecting power transmission in the first transmission system (T1);
a second engagement device (CL2) for connecting and disconnecting power transmission in the second transmission system (T2);
The sum of the output capability of the first rotating electrical machine (MG1) and the output capability of the second rotating electrical machine (MG2) is equal to or less than the output of the power storage device (ST).

According to this configuration, electric power can be simultaneously supplied from the power storage device (ST) to both the first rotating electric machine (MG1) and the second rotating electric machine (MG2), and both of them can be simultaneously powered with an output corresponding to the output capability. As a result, both the first rotating electric machine (MG1) and the second rotating electric machine (MG2) can be powered in various vehicle speed ranges, and the driving force thereof can be used for running the vehicle. Therefore, it is possible to reduce the need to ensure a large output of the second rotating electrical machine (MG2), and to suppress the enlargement of the second rotating electrical machine (MG2). As a result, it is possible to suppress an increase in the size of the drive device (100) for a series-parallel hybrid vehicle.

Here, it is preferable that the rated rotational speed of the first rotary electric machine (MG1) is equal to or higher than a value calculated by multiplying the rotational speed of the output member (2) at the maximum vehicle speed (Vm) by the gear ratio of the second transmission system (T2).

According to this configuration, the first rotating electrical machine (MG1) can be power-running in all vehicle speed ranges, and the driving force thereof can be used for running the vehicle. Therefore, it is possible to further reduce the need to ensure a large output of the second rotating electrical machine (MG2), and to further suppress an increase in the size of the second rotating electrical machine (MG2).

Further, it is preferable that the sum of the output capability of the first rotating electrical machine (MG1) and the output capability of the second rotating electrical machine (MG2) is equal to the output of the power storage device (ST).

According to this configuration, it is possible to prevent the output of the power storage device (ST) from becoming excessively large compared to the sum of the output capability of the first rotating electric machine (MG1) and the output capability of the second rotating electric machine (MG2), while ensuring the supply of electric power for powering both the first rotating electric machine (MG1) and the second rotating electric machine (MG2) at the same time. Therefore, the size of the power storage device (ST) can be optimized.

Moreover, it is preferable that the output capability of the first rotary electric machine (MG1) and the output capability of the internal combustion engine (EG) are equivalent.

According to this configuration, in the series mode, the first rotating electric machine (MG1) can efficiently generate power using the driving force of the internal combustion engine (EG).

Further, it is preferable that the output capability of the first rotating electrical machine (MG1) and the output capability of the second rotating electrical machine (MG2) are equivalent.

According to this configuration, in the series mode, the power generated by the first rotating electrical machine (MG1) and supplied to the power storage device (ST) and the power supplied from the power storage device (ST) to the second rotating electrical machine (MG2) are easily balanced. Thereby, the load on the power storage device (ST) can be reduced. As a result, it becomes easier to ensure a long life of the power storage device (ST).

Further, it is preferable that a rotating member (Ros1, second gear G2) that rotates integrally with the rotor (Ro1) of the first rotating electric machine (MG1) is arranged in the power transmission path from the internal combustion engine (EG) to the output member (2).

In general, the transmission gear ratio of the power transmission path from the internal combustion engine (EG) to the output member (2) is set relatively small so as to easily utilize the high-efficiency rotational speed of the internal combustion engine (EG). Therefore, according to this configuration, the gear ratio of the power transmission path from the first rotating electric machine (MG1) to the output member (2) is also relatively small. As a result, even when the vehicle is driven at high speed, the rotational speed of the first rotating electric machine (MG1) does not become too high, and it becomes easy to drive the first rotating electric machine (MG1) at an efficient rotational speed.

The technology according to the present disclosure can be used in a series-parallel hybrid vehicle drive system.

100: Vehicle drive device 1: Input member 2: Output member MG1: First rotating electrical machine MG2: Second rotating electrical machine ST: Power storage device T1: First transmission system T2: Second transmission system T3: Third transmission system CL1: First engagement device CL2: Second engagement device EG: Internal combustion engine W: Wheel

Claims (5)

an input member drivingly connected to an internal combustion engine;
an output member drivingly connected to the wheel;
a first rotating electrical machine and a second rotating electrical machine;
a power storage device electrically connected to the first rotating electrical machine and the second rotating electrical machine and configured to be charged from outside the vehicle;
a first transmission system drivingly connecting the input member and the first rotating electrical machine;
a second transmission system drivingly connecting the first rotating electric machine and the output member;
a third transmission system drivingly connecting the second rotating electric machine and the output member;
a first engagement device for connecting and disconnecting power transmission in the first transmission system;
a second engagement device that connects and disconnects power transmission in the second transmission system,
the sum of the output capability of the first rotating electrical machine and the output capability of the second rotating electrical machine is equal to or less than the output of the power storage device ;
The vehicle driving device, wherein the rated rotational speed of the first rotating electric machine is equal to or higher than a value calculated by multiplying the rotational speed of the output member at the maximum vehicle speed by the gear ratio of the second transmission system. an input member drivingly connected to an internal combustion engine;
an output member drivingly connected to the wheel;
a first rotating electrical machine and a second rotating electrical machine;
a power storage device electrically connected to the first rotating electrical machine and the second rotating electrical machine and configured to be charged from outside the vehicle;
a first transmission system drivingly connecting the input member and the first rotating electrical machine;
a second transmission system drivingly connecting the first rotating electric machine and the output member;
a third transmission system drivingly connecting the second rotating electric machine and the output member;
a first engagement device for connecting and disconnecting power transmission in the first transmission system;
a second engagement device that connects and disconnects power transmission in the second transmission system,
the sum of the output capability of the first rotating electrical machine and the output capability of the second rotating electrical machine is equal to or less than the output of the power storage device;
A vehicle driving device , wherein the output capability of the first rotating electrical machine is equal to the output capability of the second rotating electrical machine . 3. The vehicle drive device according to claim 1, wherein a sum of the output capability of said first rotating electric machine and the output capability of said second rotating electric machine is equivalent to the output of said power storage device. 4. The vehicle drive system according to any one of claims 1 to 3, wherein the output capability of said first rotating electrical machine and the output capability of said internal combustion engine are equivalent. 5. The vehicle drive device according to claim 1, wherein a rotating member that rotates integrally with a rotor of said first rotating electric machine is arranged in a power transmission path from said internal combustion engine to said output member.

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