JP7582022B2 - Vehicle drive device - Google Patents

Description

The present invention relates to a vehicle drive device that includes an input member that is drivingly connected to an internal combustion engine, an output member that is drivingly connected to a wheel, a rotating electric machine with a rotor, a rotor transmission member that rotates in response to the rotation of the rotor, a disconnecting engagement device that connects and disconnects the power transmission between the input member and the rotor transmission member, and a transmission provided in the power transmission path between the rotor transmission member and the output member.

An example of such a vehicle drive device is disclosed in the following Patent Document 1. In the following explanations of the "Background Art" and "Problems to be Solved by the Invention", the reference symbols in Patent Document 1 are quoted in parentheses.

In the vehicle drive device of Patent Document 1, when the disengagement engagement device (2) is engaged and the transmission (4) changes gears, shift control is executed. In this shift control, first, while maintaining the disengagement engagement device (2) in an engaged state, the transmission (4) is switched to a neutral state in a state in which the driving force input to the transmission (4) is temporarily reduced by, for example, reducing the driving force of the internal combustion engine (1) and the rotating electric machine (3). Next, by controlling the rotating electric machine (3), the rotation speed of the internal combustion engine (1) is brought closer to a target rotation speed determined according to the rotation of the output member after the gear shift via the engaged disengagement engagement device (2). Finally, the transmission (4) is caused to form the target gear.

In this way, the vehicle drive device of Patent Document 1 aims to reduce the time required for gear shift control by maintaining the engagement state of the disengagement engagement device (2) without disengaging it during gear shift control.

JP 2004-150450 A

In the above-mentioned speed change control, the rotating electric machine (3) is controlled to bring the rotation speed of the internal combustion engine (1) closer to the target rotation speed via the disengagement engagement device (2) in an engaged state. Here, the internal combustion engine (1) has a large inertia, and it is difficult to change the rotation speed. Therefore, in the above-mentioned speed change control, it takes a relatively long time for the rotation speed of the internal combustion engine (1) to approach the target rotation speed. Therefore, it has been difficult to shorten the time required for the speed change control.

Therefore, it is desirable to realize a vehicle drive device that can reduce the time required for gear shift control when the transmission changes gears while the disengagement engagement device is engaged.

In view of the above, the characteristic configuration of the vehicle drive device is as follows:
an input member drivingly connected to the internal combustion engine;
a first output member drivingly connected to the first wheel;
a first rotating electric machine including a rotor;
a rotor transmission member that rotates in response to rotation of the rotor;
a disconnection engagement device that connects and disconnects power transmission between the input member and the rotor transmission member;
a transmission provided in a power transmission path between the rotor transmission member and the first output member;
a control device that controls the internal combustion engine, the first rotating electric machine, the disengagement engagement device, and the transmission,
The transmission is configured to be selectively switched between a state in which any one of a plurality of gear stages including a first gear stage and a second gear stage having a gear ratio different from that of the first gear stage is formed, or a neutral state in which none of the gear stages is formed,
The control device executes a gear shift control when the disengagement engagement device is in an engaged state and the transmission switches from a state in which the first gear stage is formed to a state in which the second gear stage is formed,
When the transmission is in the second gear position, the rotational speeds of the input member and the rotor transmission member, which are determined in accordance with the rotation of the first output member, are defined as post-gear-shift synchronous rotational speeds,
In the gear shift control,
performing a disengagement control for changing the disengagement engagement device from an engaged state to a released state, and a driving force reduction control for reducing the driving force of the first rotating electric machine to near zero;
starting an internal combustion engine synchronization control for controlling the internal combustion engine so as to bring the rotational speed of the input member closer to the post-shift synchronous rotational speed based on the completion of the disengagement control;
starting a neutral control for placing the transmission in the neutral state based on completion of both the driving force reduction control and the disengagement control;
starting a rotating electric machine synchronous control for controlling the first rotating electric machine so as to bring the rotational speed of the rotor transmission member closer to the post-shift synchronous rotational speed based on completion of the neutral control after the start of the internal combustion engine synchronous control;
After both the internal combustion engine synchronous control and the rotating electric machine synchronous control are started,
changing the disconnecting engagement device from a released state to an engaged state after a first condition is satisfied in which a difference between a rotational speed of the input member and a rotational speed of the rotor transmission member is equal to or smaller than a specified first threshold value;
The second gear stage is formed in the transmission after a second condition is satisfied, that is, the difference between the rotational speed of the input member and the synchronous rotational speed after the shift is equal to or less than a specified second threshold value, and the difference between the rotational speed of the rotor transmission member and the synchronous rotational speed after the shift is equal to or less than the second threshold value.

According to this characteristic configuration, based on the completion of the disengagement control that changes the disengagement engagement device from an engaged state to a released state, the internal combustion engine synchronous control is started to control the internal combustion engine so that the rotation speed of the input member approaches the post-shift synchronous rotation speed. Therefore, the internal combustion engine synchronous control can be started based on the completion of the disengagement control without waiting for the completion of the neutral control that places the transmission in a neutral state. Also, according to this characteristic configuration, the internal combustion engine synchronous control is started before the start of the rotating electric machine synchronous control. Therefore, the internal combustion engine synchronous control can be started relatively early. Here, the internal combustion engine has a large inertia and it is difficult to change the rotation speed. However, as described above, according to this characteristic configuration, the internal combustion engine synchronous control can be started relatively early, so that it is easy to avoid a delay in the completion of the internal combustion engine synchronous control.
According to this characteristic configuration, when the disconnection engagement device is in the disengaged state, a rotating electric machine synchronous control is started to control the first rotating electric machine so as to bring the rotation speed of the rotor transmission member closer to the synchronous rotation speed after the shift. This allows the rotating electric machine synchronous control to be executed in a state in which the internal combustion engine is disconnected, so that the rotation speed of the rotor transmission member can be brought closer to the synchronous rotation speed after the shift without being affected by the inertia of the internal combustion engine. This makes it possible to shorten the time required for the rotating electric machine synchronous control.
As described above, according to this characteristic configuration, it is possible to shorten the time required for the gear shift control to be executed when the transmission changes gear positions while the disengagement engagement device is in an engaged state.

FIG. 1 is a skeleton diagram of a first drive unit of a vehicle drive device according to an embodiment; FIG. 1 is a skeleton diagram of a second drive unit of a vehicle drive device according to an embodiment; Control block diagram of a vehicle drive device according to an embodiment FIG. 4 is a diagram showing a state of an engagement device in each operation mode of the vehicle drive device according to the embodiment; 1 is a flowchart showing an example of a shift control when the transmission performs an upshift while the disengagement engagement device is engaged. FIG. 1 is a time chart showing an example of shift control when the transmission performs an upshift while the disengagement engagement device is engaged. FIG. 13 is a skeleton diagram of a first drive unit of a vehicle drive device according to another embodiment.

The vehicle drive device 100 according to the embodiment will be described below with reference to the drawings. As shown in FIG. 1, in this embodiment, the vehicle drive device 100 includes a first drive unit DU1 that drives a pair of first wheels W1, and a second drive unit DU2 that drives a pair of second wheels W2. In this embodiment, the first wheels W1 are the front wheels of the vehicle, and the second wheels W2 are the rear wheels of the vehicle.

The first drive unit DU1 includes an input member I that is drivingly connected to the internal combustion engine EG, a first output member O1 that is drivingly connected to the first wheel W1, a first rotating electric machine MG1, a rotor transmission member T, a first engagement device CL1, and a transmission TM. In this embodiment, the first drive unit DU1 further includes a distribution differential gear mechanism SP, a second engagement device CL2, and a first output differential gear mechanism DF1. In addition, in this embodiment, the transmission TM includes a third engagement device CL3.

In this application, "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit a 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 a driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed, such as shafts, gear mechanisms, belts, chains, etc. In addition, transmission members may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices. However, when referring to each rotating element of a planetary gear mechanism, the term "driving connection" refers to a state in which multiple rotating elements in the planetary gear mechanism are connected to each other without going through other rotating elements.

In this embodiment, the input member I, rotor transmission member T, first engagement device CL1, and second engagement device CL2 are arranged on the first axis X1, which serves as their rotational axis. The first rotating electric machine MG1 is arranged on the second axis X2, which serves as its rotational axis. Furthermore, the third engagement device CL3 of the transmission TM is arranged on the third axis X3, which serves as its rotational axis. The first output member O1 and the first output differential gear mechanism DF1 are arranged on the fourth axis X4, which serves as their rotational axis.

In this embodiment, the second drive unit DU2 includes a second output member O2 that is drivingly connected to the second wheel W2, a second rotating electric machine MG2, a counter gear mechanism CG, and a second output differential gear mechanism DF2.

In this embodiment, the second rotating electric machine MG2 is disposed on the fifth axis X5, which serves as its rotation axis. The counter gear mechanism CG is disposed on the sixth axis X6, which serves as its rotation axis. The second output member O2 and the second output differential gear mechanism DF2 are disposed on the seventh axis X7, which serves as their rotation axis.

In this example, the above-mentioned axes X1 to X7 are arranged parallel to each other. In the following description, the direction parallel to the above-mentioned axes X1 to X7 is referred to as the "axial direction L" of the vehicle drive device 100. One side of the axial direction L is referred to as the "axial first side L1", and the other side of the axial direction L is referred to as the "axial second side L2". In this embodiment, in the axial direction L, the side where the input member I is arranged relative to the internal combustion engine EG is referred to as the axial first side L1, and the opposite side is referred to as the axial second side L2. In addition, the direction perpendicular to each of the above-mentioned axes X1 to X7 is referred to as the "radial direction R" based on each axis. Note that when it is not necessary to distinguish which axis is used as the reference or when it is clear which axis is used as the reference, it may be simply referred to as the "radial direction R".

In this embodiment, the input member I is an input shaft 1 extending along the axial direction L. The input shaft 1 is drivingly connected to an output shaft ES of the internal combustion engine EG via a damper device DP that dampens fluctuations in the transmitted torque. The internal combustion engine EG is a prime mover (gasoline engine, diesel engine, etc.) that is driven by the combustion of fuel to extract power. In this embodiment, the internal combustion engine EG functions as a driving force source for the first wheel W1.

The first rotating electric machine MG1 functions as a driving force source for the first wheel W1. The first rotating electric machine MG1 has a function as a motor (electric motor) that receives a supply of electric power to generate power, and a function as a generator (electric generator) that receives a supply of power to generate electric power. Specifically, the first rotating electric machine MG1 is electrically connected to an electric storage device BT (see FIG. 3) such as a battery or a capacitor so as to exchange electric power with the electric storage device BT. The first rotating electric machine MG1 generates driving force by running using the electric power stored in the electric storage device BT. The first rotating electric machine MG1 also generates electric power using the driving force of the internal combustion engine EG or the driving force transmitted from the first output member O1 to charge the electric storage device BT.

The first rotating electric machine MG1 includes a first stator ST1 and a first rotor RT1. The first stator ST1 is fixed to a non-rotating member (e.g., a case that houses the first rotating electric machine MG1, etc.). The first rotor RT1 is supported rotatably relative to the first stator ST1. In this embodiment, the first rotor RT1 is disposed radially inward relative to the first stator ST1.

In this embodiment, the first rotor gear RG1 is connected to the first rotor RT1 so as to rotate integrally with the first rotor RT1 via a first rotor shaft RS1 formed to extend along the axial direction L. In this embodiment, the first rotor gear RG1 is disposed on the second axis X2. In the example shown in FIG. 1, the first rotor gear RG1 is disposed on the second axial side L2 of the first rotor RT1.

The distribution differential gear mechanism SP includes a first rotating element E1, a second rotating element E2, and a third rotating element E3. The first rotating element E1 is drivingly connected to the input member I. The third rotating element E3 is drivingly connected to the first rotor RT1. In this embodiment, each of the second rotating element E2 and the third rotating element E3 is drivingly connected to the first output member O1.

In this embodiment, the distribution differential gear mechanism SP is a planetary gear mechanism that includes a sun gear S1, a carrier C1, and a ring gear R1. In this example, the distribution differential gear mechanism SP is a single-pinion type planetary gear mechanism that includes a carrier C1 that supports a pinion gear P1, a sun gear S1 that meshes with the pinion gear P1, and a ring gear R1 that is disposed radially outward of the sun gear S1 in the R direction and meshes with the pinion gear P1.

In this embodiment, the order of rotational speeds of the rotating elements of the distribution differential gear mechanism SP is the first rotating element E1, the second rotating element E2, and the third rotating element E3. Therefore, in this embodiment, the first rotating element E1 is the sun gear S1. The second rotating element E2 is the carrier C1. The third rotating element E3 is the ring gear R1. Here, the "order of rotational speeds" refers to the order of the rotational speeds of each rotating element in its rotational state. The rotational speeds of each rotating element change depending on the rotational state of the planetary gear mechanism, but the order of high and low rotational speeds of each rotating element is fixed because it is determined by the structure of the planetary gear mechanism.

The first engagement device CL1 is a "disengagement engagement device" that connects and disconnects the power transmission between the input member I and the rotor transmission member T. In this embodiment, the first engagement device CL1 connects and disconnects the power transmission between the input member I and the sun gear S1 as the first rotating element E1 of the distribution differential gear mechanism SP. In the example shown in FIG. 1, the first engagement device CL1 is disposed on the second axial side L2 with respect to the distribution differential gear mechanism SP. In this example, the first engagement device CL1 is a friction engagement device that includes an input element that is a rotating element on the input member I side, and an output element that is a rotating element on the distribution differential gear mechanism SP side, and the state of engagement (engaged state/disengaged state) is controlled according to the engagement pressure between these elements.

The second engagement device CL2 is an engagement device that connects and disconnects the power transmission between two selected from the three rotating elements of the first rotating element E1, the second rotating element E2, and the third rotating element E3 in the distribution differential gear mechanism SP. In this embodiment, the second engagement device CL2 is configured to connect and disconnect the power transmission between the carrier C1 as the second rotating element E2 and the ring gear R1 as the third rotating element E3. When the second engagement device CL2 is in a released state, the three rotating elements E1 to E3 of the distribution differential gear mechanism SP are in a state in which they can rotate relative to each other. On the other hand, when the second engagement device CL2 is in an engaged state, the three rotating elements E1 to E3 of the distribution differential gear mechanism SP are in a state in which they rotate integrally with each other. In the example shown in FIG. 1, the second engagement device CL2 is disposed between the first engagement device CL1 and the distribution differential gear mechanism SP in the axial direction L. In this example, the second engagement device CL2 is a meshing type engagement device (dog clutch) that can be switched between an engaged state and a released state by an actuator such as a solenoid, an electric motor, or a hydraulic cylinder.

In this embodiment, when performing the "speed change control" described later, the second engagement device CL2 is engaged, and the three rotating elements E1 to E3 of the distribution differential gear mechanism SP rotate together. In this state, the entire distribution differential gear mechanism SP (i.e., all three rotating elements E1 to E3) rotates in response to the rotation of the first rotor RT1. Therefore, in this embodiment, the distribution differential gear mechanism SP functions as a "rotor transmission member T" that rotates in response to the rotation of the first rotor RT1. Note that, when the second engagement device CL2 is in a disengaged state, the ring gear R1, which is the third rotating element E3 among the three rotating elements E1 to E3 of the distribution differential gear mechanism SP, functions as the "rotor transmission member T". In addition, in this embodiment, the first rotor gear RG1 and the idler gear IG also rotate in response to the rotation of the first rotor RT1, and therefore also function as the "rotor transmission member T".

The transmission TM is provided in the power transmission path between the rotor transmission member T and the first output member O1. The transmission TM is configured to be able to selectively form one of a plurality of gears, including a first gear and a second gear having a different gear ratio from the first gear. The transmission TM changes the speed of the rotation transmitted from the rotor transmission member T at a gear ratio corresponding to the formed gear and transmits it to the first output member O1. When the gear ratio corresponding to the formed gear is 1, the transmission TM transmits the rotation transmitted from the rotor transmission member T as is to the first output member O1. In this embodiment, the transmission TM selectively forms one of two gears, the first gear and the second gear having a smaller gear ratio than the first gear, depending on the state of the third engagement device CL3.

The transmission TM is also configured to be switchable to a neutral state in which no gear is formed. When the transmission TM is in a neutral state, the transmission TM is in a state in which it does not transmit the rotation transmitted from the rotor transmission member T to the first output member O1, that is, the driving force of neither the internal combustion engine EG nor the first rotating electric machine MG1 is transmitted to the first wheel W1. In this way, the transmission TM is configured to be selectively switchable between a state in which any of a plurality of gears is formed, including the first gear and a second gear having a different gear ratio from the first gear, or a neutral state in which no gear is formed.

In this embodiment, the transmission TM includes a first gear G1, a second gear G2, a third gear G3, a fourth gear G4, and a transmission output gear 3. In this embodiment, the first gear G1 and the second gear G2 are arranged on the first axis X1. The third gear G3, the fourth gear G4, and the transmission output gear 3 are arranged on the third axis X3.

The first gear G1 is connected to the second rotating element E2 (here, the carrier C1) of the distribution differential gear mechanism SP so as to rotate integrally with it. In this embodiment, the first gear G1 is disposed on the first axial side L1 relative to the distribution differential gear mechanism SP.

The second gear G2 is connected to the third rotating element E3 (here, the ring gear R1) of the distribution differential gear mechanism SP so as to rotate integrally. In this embodiment, a cylindrical gear forming member 2 is provided with the first axis X1 as its axis. The second gear G2 is formed on the outer peripheral surface of the gear forming member 2, and the ring gear R1 is formed on the inner peripheral surface of the gear forming member 2. In this embodiment, the second gear G2 is disposed on the outer side of the ring gear R1 in the radial direction R, and is disposed at a position overlapping with the distribution differential gear mechanism SP when viewed in the radial direction along the radial direction R. Here, with regard to the arrangement of the two elements, "overlapping when viewed in a specific direction" refers to the existence of at least a portion of an area where a virtual line parallel to the line of sight intersects with both of the two elements when the virtual line is moved in each direction perpendicular to the virtual line.

In addition, in this embodiment, the second gear G2 is drivingly connected to the first rotor gear RG1 via an idler gear IG that is arranged on a different axis from the first axis X1 to the fourth axis X4. In other words, in this embodiment, the second gear G2 and the first rotor gear RG1 mesh with the idler gear IG at different positions in the circumferential direction of the idler gear IG. As a result, the second gear G2 and the first rotor gear RG1 are connected to rotate in conjunction with each other via the idler gear IG.

The third gear G3 and the fourth gear G4 are supported so as to be rotatable relative to each other. The third gear G3 meshes with the first gear G1. The fourth gear G4 meshes with the second gear G2. In this embodiment, the fourth gear G4 meshes with the second gear G2 at a position different from the idler gear IG in the circumferential direction of the second gear G2. The transmission output gear 3 is supported so as to be rotatable relative to the third gear G3 and the fourth gear G4.

The number of teeth of the first gear G1 and the number of teeth of the second gear G2 are different from each other. That is, the outer diameter of the first gear G1 and the outer diameter of the second gear G2 are different. And, as described above, the first gear G1 and the second gear G2 are arranged on the same axis, and the third gear G3 meshing with the first gear G1 and the fourth gear G4 meshing with the second gear G2 are arranged on the same axis. Therefore, when the outer diameter of the first gear G1 is smaller than the outer diameter of the second gear G2, the outer diameter of the third gear G3 is larger than the outer diameter of the fourth gear G4. On the other hand, when the outer diameter of the first gear G1 is larger than the outer diameter of the second gear G2, the outer diameter of the third gear G3 is smaller than the outer diameter of the fourth gear G4. Therefore, the gear ratio of the third gear G3 to the first gear G1 and the gear ratio of the fourth gear G4 to the second gear G2 are different. In this embodiment, the outer diameter of the first gear G1 is smaller than the outer diameter of the second gear G2, and the number of teeth of the first gear G1 is smaller than the number of teeth of the second gear G2. Therefore, in this embodiment, the outer diameter of the third gear G3 is larger than the outer diameter of the fourth gear G4, and the number of teeth of the third gear G3 is larger than the number of teeth of the fourth gear G4. Therefore, in this embodiment, the gear ratio of the third gear G3 to the first gear G1 is larger than the gear ratio of the fourth gear G4 to the second gear G2.

The third engagement device CL3 is an engagement device that switches the state of power transmission between the rotor transmission member T and the first output member O1. In this embodiment, the third engagement device CL3 is configured to selectively connect either the third gear G3 or the fourth gear G4 to the transmission output gear 3. In this example, the third engagement device CL3 is a meshing type engagement device (dog clutch) that is configured to be able to switch between an engaged state and a released state by an actuator such as a solenoid, an electric motor, or a hydraulic cylinder.

In this embodiment, when the third engagement device CL3 connects the third gear G3 to the transmission output gear 3, power is transmitted between the carrier C1 as the second rotating element E2 of the distribution differential gear mechanism SP and the first output member O1. On the other hand, when the third engagement device CL3 connects the fourth gear G4 to the transmission output gear 3, power is transmitted between the ring gear R1 as the third rotating element E3 of the distribution differential gear mechanism SP and the first output member O1.

As described above, in this embodiment, the gear ratio of the third gear G3 to the first gear G1 is greater than the gear ratio of the fourth gear G4 to the second gear G2. Therefore, when the third engagement device CL3 connects the third gear G3 to the transmission output gear 3, a first gear stage (low gear stage) with a relatively large gear ratio is formed. On the other hand, when the third engagement device CL3 connects the fourth gear G4 to the transmission output gear 3, a second gear stage (high gear stage) with a relatively small gear ratio is formed. Note that the state of the third engagement device CL3 when the transmission TM forms any gear stage corresponds to the engaged state of the third engagement device CL3. On the other hand, the state of the third engagement device CL3 when the transmission TM is in a neutral state corresponds to the released state of the third engagement device CL3.

In this manner, in this embodiment, the transmission TM is configured as a parallel shaft gear type transmission including a first gear G1 and a second gear G2 arranged coaxially with each other, and a third gear G3 and a fourth gear G4 that mesh with the first gear G1 and the second gear G2, respectively, and are arranged coaxially with each other.

The first output differential gear mechanism DF1 is configured to distribute the rotation of the first output member O1 to a pair of first wheels W1. In this embodiment, the first output member O1 is a first differential input gear 4 that meshes with the transmission output gear 3.

In this embodiment, the first output differential gear mechanism DF1 is a bevel gear type differential gear mechanism. Specifically, the first output differential gear mechanism DF1 includes a hollow first differential case, a first pinion shaft supported so as to rotate integrally with the first differential case, a pair of first pinion gears supported rotatably relative to the first pinion shaft, and a pair of first side gears meshing with the pair of first pinion gears to function as distribution output elements. The first differential case houses the first pinion shaft, the pair of first pinion gears, and the pair of first side gears.

In this embodiment, a first differential input gear 4 serving as a first output member O1 is connected to the first differential case so as to protrude outward from the first differential case in the radial direction R. A first drive shaft DS1 drivingly connected to the first wheels W1 is connected to each of the pair of first side gears so as to rotate integrally with the first side gears. Thus, in this embodiment, the first output differential gear mechanism DF1 distributes the rotation of the first differential input gear 4 serving as the first output member O1 to the pair of first wheels W1 via the pair of first drive shafts DS1.

As shown in FIG. 2, the second rotating electric machine MG2 functions as a driving force source for the second wheel W2. The second rotating electric machine MG2 has a function as a motor (electric motor) that receives a supply of electric power to generate power, and a function as a generator (electric generator) that receives a supply of power to generate power. Specifically, the second rotating electric machine MG2 is electrically connected to the above-mentioned power storage device BT (see FIG. 3) so as to exchange electric power with the power storage device BT. The second rotating electric machine MG2 generates driving force by running using the electric power stored in the power storage device BT. During regeneration, the second rotating electric machine MG2 generates power using the driving force transmitted from the second output member O2 to charge the power storage device BT.

The second rotating electric machine MG2 includes a second stator ST2 and a second rotor RT2. The second stator ST2 is fixed to a non-rotating member (e.g., a case that houses the second rotating electric machine MG2, etc.). The second rotor RT2 is supported rotatably relative to the second stator ST2. In this embodiment, the second rotor RT2 is disposed radially inward relative to the second stator ST2.

In this embodiment, the second rotor gear RG2 is connected to the second rotor RT2 so as to rotate integrally with the second rotor RT2 via a second rotor shaft RS2 formed to extend along the axial direction L. In this embodiment, the second rotor gear RG2 is disposed on the fifth axis X5. In the example shown in FIG. 2, the second rotor gear RG2 is disposed on the first axial side L1 of the second rotor RT2.

The counter gear mechanism CG includes a counter input gear 61, a counter output gear 62, and a counter shaft 63 that connects these gears 61, 62 so that they rotate together.

The counter input gear 61 is an input element of the counter gear mechanism CG. In this embodiment, the counter input gear 61 meshes with the second rotor gear RG2. The counter output gear 62 is an output element of the counter gear mechanism CG. In the example shown in FIG. 2, the counter output gear 62 is disposed on the second axial side L2 from the counter input gear 61. In addition, the counter output gear 62 is formed with a smaller diameter than the counter input gear 61.

The second output differential gear mechanism DF2 is configured to distribute the rotation of the second output member O2 to a pair of second wheels W2. In this embodiment, the second output member O2 is a second differential input gear 7 that meshes with the counter output gear 62 of the counter gear mechanism CG.

In this embodiment, the second output differential gear mechanism DF2 is a bevel gear type differential gear mechanism. Specifically, the second output differential gear mechanism DF2 includes a hollow second differential case, a second pinion shaft supported so as to rotate integrally with the second differential case, a pair of second pinion gears supported rotatably relative to the second pinion shaft, and a pair of second side gears that mesh with the pair of second pinion gears and function as distribution output elements. The second differential case houses the second pinion shaft, the pair of second pinion gears, and the pair of second side gears.

In this embodiment, a second differential input gear 7 as a second output member O2 is connected to the second differential case so as to protrude outward from the second differential case in the radial direction R. A second drive shaft DS2 drivingly connected to the second wheels W2 is connected to each of the pair of second side gears so as to rotate integrally with the second side gears. Thus, in this embodiment, the second output differential gear mechanism DF2 distributes the rotation of the second output member O2 (here, the second differential input gear 7) to the pair of second wheels W2 via the pair of second drive shafts DS2.

As shown in FIG. 3, the vehicle drive device 100 includes a control device 10 that controls the internal combustion engine EG, the first rotating electric machine MG1, the first engagement device CL1, and the transmission TM. In this embodiment, the control device 10 includes a main control unit 11, an internal combustion engine control unit 12 that controls the internal combustion engine EG, a first rotating electric machine control unit 13 that controls the first rotating electric machine MG1, a second rotating electric machine control unit 14 that controls the second rotating electric machine MG2, and an engagement control unit 15 that controls the engagement state of the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3.

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 to control the devices handled by each control unit. The internal combustion engine control unit 12 controls the internal combustion engine EG so that the internal combustion engine EG outputs the commanded driving force commanded by the main control unit 11, or so that the internal combustion engine EG rotates at the commanded rotation speed commanded by the main control unit 11. The first rotating electric machine control unit 13 controls the first rotating electric machine MG1 so that the first rotating electric machine MG1 outputs the commanded driving force commanded by the main control unit 11, or so that the first rotating electric machine MG1 rotates at the commanded rotation speed commanded by the main control unit 11. The second rotating electric machine control unit 14 controls the second rotating electric machine MG2 so that the second rotating electric machine MG2 outputs the commanded driving force commanded by the main control unit 11, or so that the second rotating electric machine MG2 rotates at the commanded rotation speed commanded by the main control unit 11. The engagement control unit 15 controls actuators (not shown) for operating the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3 so that each of the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3 is in the engagement state commanded by the main control unit 11.

The main control unit 11 is also configured to be able to acquire information from sensors provided in various parts of the vehicle in order to acquire information on 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.

The SOC sensor Se1 is a sensor for detecting the state of the power storage device BT electrically connected to the first rotating electric machine MG1 and the second rotating electric machine MG2. The SOC sensor Se1 is composed of, for example, a voltage sensor and a current sensor. The main control unit 11 calculates the charge amount (SOC: State of Charge) of the power storage device BT based on information such as the voltage value and current value output from the SOC sensor Se1.

The vehicle speed sensor Se2 is a sensor for detecting the traveling speed (vehicle speed) of the vehicle on which the vehicle drive device 100 is mounted. In this embodiment, the vehicle speed sensor Se2 is a sensor for detecting the rotational speed of the first output member O1. The main control unit 11 calculates the rotational speed (angular velocity) of the first output member O1 based on the detection signal of the vehicle speed sensor Se2. Since the rotational speed of the first output member O1 is proportional to the vehicle speed, the main control unit 11 can calculate the vehicle speed based on the detection signal of the vehicle speed sensor Se2.

The accelerator operation amount sensor Se3 is a sensor for detecting the amount of operation (accelerator opening) of the accelerator pedal provided on the vehicle in which the vehicle drive device 100 is installed, by the driver. The main control unit 11 calculates the accelerator opening based on the detection signal of the accelerator operation amount sensor Se3.

The brake operation amount sensor Se4 is a sensor for detecting the amount of operation of the brake pedal by the driver, which is provided on the vehicle in which the vehicle drive device 100 is installed. 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.

The shift position sensor Se5 is a sensor for detecting the selected position (shift position) of the shift lever operated by the driver of the vehicle in which the vehicle drive device 100 is installed. The main control unit 11 calculates the shift position based on the detection signal of the shift position sensor Se5. The shift lever is configured to be able to select a parking range (P range), a reverse driving range (R range), a neutral range (N range), a forward driving range (D range), etc.

Based on information from the above sensors Se1 to Se5, the main control unit 11 selects from a number of operating modes for the first drive unit DU1, which will be described later. The main control unit 11 transitions to the selected operating mode by controlling the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3 via the engagement control unit 15 to an engagement state that corresponds to the selected operating mode. Furthermore, the main control unit 11 enables the vehicle to travel appropriately according to the selected operating mode by cooperatively controlling 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.

As shown in FIG. 4, in this embodiment, the vehicle drive device 100 has the following operating modes: an electric torque converter mode (hereinafter referred to as "eTC mode"), a first EV mode, a second EV mode, a first HV mode, a second HV mode, and a charging mode.

Figure 4 shows the states of the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3 in each operation mode of this embodiment. In the columns of the first engagement device CL1 and the second engagement device CL2 in Figure 4, "◯" indicates that the target engagement device is in an engaged state, and "×" indicates that the target engagement device is in a disengaged state. In the column of the third engagement device CL3 in Figure 4, "Lo" indicates the state of the third engagement device CL3 when the transmission TM forms the first gear stage (low gear stage), that is, the state in which the third engagement device CL3 connects the third gear G3 to the transmission output gear 3. And "Hi" indicates the state of the third engagement device CL3 when the transmission TM forms the second gear stage (high gear stage), that is, the state in which the third engagement device CL3 connects the fourth gear G4 to the transmission output gear 3. Additionally, "N" indicates the state of the third engagement device CL3 when the transmission TM is in neutral, that is, the third engagement device CL3 is in a disengaged state.

The eTC mode is a mode in which the distribution differential gear mechanism SP amplifies the torque of the internal combustion engine EG using the torque of the first rotating electric machine MG1 as a reaction force and transmits it to the first output member O1, thereby propelling the vehicle. The eTC mode is known as an electric torque converter mode, since it can amplify the torque of the internal combustion engine EG and transmit it to the first output member O1.

As shown in FIG. 4, in the eTC mode, the first engagement device CL1 is engaged, the second engagement device CL2 is disengaged, and the third engagement device CL3 is engaged. The driving force of the internal combustion engine EG and the first rotating electric machine MG1 is transmitted to the first output member O1. In the eTC mode of this embodiment, the first engagement device CL1 is controlled to be in an engaged state, the second engagement device CL2 is disengaged, and the third engagement device CL3 is controlled to be in a state forming the first gear stage (low gear stage).

In the eTC mode of this embodiment, the first rotating electric machine MG1 generates electricity by outputting positive torque while rotating in the negative direction, and the distribution differential gear mechanism SP combines the driving force of the first rotating electric machine MG1 with the driving force of the internal combustion engine EG to output a driving force greater than the driving force of the internal combustion engine EG from the second rotating element E2 (here, the carrier C1). The rotation of the second rotating element E2 is then shifted in the transmission TM at a gear ratio corresponding to the first gear (low gear) and transmitted to the first output member O1. Therefore, the eTC mode can be selected even when the charge level of the power storage device BT is relatively low.

The first EV mode is a mode in which the vehicle runs at a relatively low speed using the driving force of only the first rotating electric machine MG1 out of the internal combustion engine EG and the first rotating electric machine MG1. The second EV mode is a mode in which the vehicle runs at a relatively high speed using the driving force of only the first rotating electric machine MG1 out of the internal combustion engine EG and the first rotating electric machine MG1.

As shown in FIG. 4, in the first EV mode and the second EV mode, the first engagement device CL1 is in a disengaged state, the second engagement device CL2 is in an engaged state, and the third engagement device CL3 is in an engaged state. The internal combustion engine EG is then in a stopped state in which it does not output driving force, and the driving force of the first rotating electric machine MG1 is transmitted to the first output member O1. In the first EV mode of this embodiment, the first engagement device CL1 is controlled to be in a disengaged state, the second engagement device CL2 is controlled to be in an engaged state, and the third engagement device CL3 is controlled to be in a state in which the first gear stage (low gear stage) is formed. On the other hand, in the second EV mode of this embodiment, the first engagement device CL1 is controlled to be in a disengaged state, the second engagement device CL2 is controlled to be in an engaged state, and the third engagement device CL3 is controlled to be in a state in which the second gear stage (high gear stage) is formed.

In the first EV mode and the second EV mode of this embodiment, the first engagement device CL1 is disengaged, and the internal combustion engine EG is separated from the distribution differential gear mechanism SP, and power transmission between the internal combustion engine EG and the first output member O1 is interrupted. Then, the second engagement device CL2 is engaged, and the three rotating elements E1 to E3 of the distribution differential gear mechanism SP rotate integrally with each other. As a result, the rotation input to the distribution differential gear mechanism SP from the first rotating electric machine MG1 is transmitted as is to the transmission TM. Then, the rotation transmitted to the transmission TM is shifted to the gear ratio of the first gear stage (low gear stage) in the first EV mode and the gear ratio of the second gear stage (high gear stage) in the second EV mode according to the state of the third engagement device CL3, and transmitted to the first output member O1.

The first HV mode is a mode in which the vehicle runs at a relatively low speed using at least the driving force of the internal combustion engine EG out of the internal combustion engine EG and the first rotating electric machine MG1. The second HV mode is a mode in which the vehicle runs at a relatively high speed using at least the driving force of the internal combustion engine EG out of the internal combustion engine EG and the first rotating electric machine MG1.

As shown in FIG. 4, in the first HV mode of this embodiment, the first engagement device CL1 and the second engagement device CL2 are both engaged, and the third engagement device CL3 is controlled to be in a state in which it forms the first gear stage (low gear stage). On the other hand, in the second HV mode of this embodiment, the first engagement device CL1 and the second engagement device CL2 are both engaged, and the third engagement device CL3 is controlled to be in a state in which it forms the second gear stage (high gear stage).

In the first HV mode and the second HV mode of this embodiment, the first engagement device CL1 is engaged, so that the internal combustion engine EG is connected to the distribution differential gear mechanism SP. Then, the second engagement device CL2 is engaged, so that the three rotating elements E1 to E3 of the distribution differential gear mechanism SP rotate integrally with each other. As a result, the rotation input to the distribution differential gear mechanism SP from the internal combustion engine EG and the first rotating electric machine MG1 is transmitted directly to the transmission TM. Then, the rotation transmitted to the transmission TM is shifted to the gear ratio of the first gear stage (low gear stage) in the first HV mode and the gear ratio of the second gear stage (high gear stage) in the second HV mode according to the state of the third engagement device CL3, and transmitted to the first output member O1.

The charging mode is a mode in which the first rotating electric machine MG1 generates electricity using the driving force of the internal combustion engine EG to charge the power storage device BT. As shown in FIG. 4, in the charging mode, the first engagement device CL1 is controlled to be in an engaged state, the second engagement device CL2 is controlled to be in an engaged state, and the third engagement device CL3 is controlled to be in a disengaged state. The internal combustion engine EG outputs a driving force, and the first rotating electric machine MG1 is controlled to generate electricity by outputting a driving force in the opposite direction to the rotation direction of the first rotor RT1 rotated by the driving force of the internal combustion engine EG. In the charging mode, the vehicle may be stopped, or the second rotating electric machine MG2 may be powered by the electric power generated by the first rotating electric machine MG1, and the driving force of the second rotating electric machine MG2 may be transmitted to the second wheel W2 to run the vehicle. This mode in which the vehicle runs using the driving force of the second rotating electric machine MG2 while in charging mode is called a series hybrid mode.

The control device 10 executes gear shift control when the first engagement device CL1 is engaged and the transmission TM switches from a state in which the first gear stage is formed to a state in which the second gear stage is formed. As described above, in this embodiment, the second gear stage has a smaller gear ratio than the first gear stage. Therefore, in this embodiment, the control device 10 executes gear shift control when the first engagement device CL1 is engaged and the transmission TM performs an upshift. As described above, in this embodiment, the gear shift control is executed when there is a mode transition between the first EV mode and the second EV mode, or between the first HV mode and the second HV mode. In either case, the second engagement device CL2 is maintained in an engaged state, and the three rotating elements E1 to E3 of the distribution differential gear mechanism SP as the rotor transmission member T rotate integrally with each other.

In the shift control, the control device 10 performs disengagement control to change the first engagement device CL1 from an engaged state to a released state, and driving force reduction control to bring the driving force of the first rotating electric machine MG1 closer to zero. In the disengagement control of this embodiment, the engagement control unit 15 changes the first engagement device CL1 from an engaged state to a released state. In the driving force reduction control of this embodiment, the first rotating electric machine control unit 13 controls the first rotating electric machine MG1 so that the driving force of the first rotating electric machine MG1 becomes zero.

Based on the completion of the above-mentioned disconnection control, the control device 10 starts internal combustion engine synchronous control to control the internal combustion engine EG so that the input rotation speed Ni, which is the rotation speed of the input member I, approaches the post-shift synchronous rotation speed Ns2. In the internal combustion engine synchronous control of this embodiment, the internal combustion engine control unit 12 controls the internal combustion engine EG so that the input rotation speed Ni becomes the post-shift synchronous rotation speed Ns2. Here, the post-shift synchronous rotation speed Ns2 is the rotation speed of the input member I and the rotor transmission member T that is determined according to the rotation of the first output member O1 when the transmission TM forms the second gear stage. Note that, with respect to multiple controls with different start times, "starting the second control based on the completion of the first control" means starting the second control on the condition that the first control is completed, and includes starting the second control immediately after the first control is completed and starting the second control after a specified time has elapsed since the first control is completed.

The control device 10 starts neutral control to place the transmission TM in a neutral state based on the completion of both the driving force reduction control and the disengagement control. In the neutral control of this embodiment, the engagement control unit 15 disengages the third engagement device CL3 so that the transmission TM goes from the first gear (low gear) to the neutral state.

After the internal combustion engine synchronous control is started, the control device 10 starts the rotating electric machine synchronous control, which controls the first rotating electric machine MG1 so that the rotor transmission rotation speed Nt, which is the rotation speed of the rotor transmission member T, approaches the synchronous rotation speed Ns2 after the shift, based on the completion of the neutral control. In the rotating electric machine synchronous control of this embodiment, the first rotating electric machine control unit 13 controls the first rotating electric machine MG1 so that the rotor transmission rotation speed Nt becomes the synchronous rotation speed Ns2 after the shift.

After both the internal combustion engine synchronous control and the rotating electric machine synchronous control are started, the control device 10 changes the first engagement device CL1 from a disengaged state to an engaged state after satisfying a first condition (|Ni-Nt|≦TH1) in which the difference between the input rotation speed Ni and the rotor transmission rotation speed Nt is equal to or less than a specified first threshold value TH1. Note that it is preferable to set the first threshold value TH1 to a value that does not change so that either the input rotation speed Ni or the rotor transmission rotation speed Nt moves away from the post-shift synchronous rotation speed Ns2.

Furthermore, after both the internal combustion engine synchronous control and the rotating electric machine synchronous control are started, the control device 10 causes the transmission TM to form the second gear stage after the difference between the input rotation speed Ni and the post-shift synchronous rotation speed Ns2 is equal to or less than a specified second threshold value TH2, and after the difference between the rotor transmission rotation speed Nt and the post-shift synchronous rotation speed Ns2 is equal to or less than the second threshold value TH2 (|Ni-Ns2|≦TH2 and |Nt-Ns2|≦TH2). Note that, for example, when the third engagement device CL3 is a meshing engagement device (dog clutch), the second threshold value TH2 is preferably set to a value that allows the third engagement device CL3 to be appropriately engaged.

As described above, the vehicle drive device 100 has
An input member I drivingly connected to an internal combustion engine EG;
a first output member O1 drivingly connected to the first wheel W1;
a first rotating electric machine MG1 including a first rotor RT1;
A rotor transmission member T that rotates in response to the rotation of the first rotor RT1;
a first engagement device CL1 that connects and disconnects power transmission between the input member I and the rotor transmission member T;
a transmission TM provided in a power transmission path between the rotor transmission member T and the first output member O1;
a control device 10 that controls the internal combustion engine EG, the first rotating electric machine MG1, the first engagement device CL1, and the transmission TM,
The transmission TM is configured to be selectively switchable between a state in which any of a plurality of gear stages including a first gear stage and a second gear stage having a gear ratio different from that of the first gear stage is formed, or a neutral state in which no gear stage is formed;
The control device 10 executes gear shift control when the first engagement device CL1 is in an engaged state and the transmission TM is switched from a state in which the first gear stage is formed to a state in which the second gear stage is formed,
When the transmission TM is in the second gear position, the rotational speed of the input member I and the rotor transmission member T, which is determined according to the rotation of the first output member O1, is defined as a post-shift synchronous rotational speed Ns2.
In gear shift control,
performing a disengagement control for changing the first engagement device CL1 from an engaged state to a released state and a driving force reduction control for bringing the driving force of the first rotating electric machine MG1 closer to zero;
Based on the completion of the disengagement control, an internal combustion engine synchronous control is started to control the internal combustion engine EG so that the input rotation speed Ni, which is the rotation speed of the input member I, approaches the post-shift synchronous rotation speed Ns2.
Based on the completion of both the driving force reduction control and the disengagement control, a neutral control is started to place the transmission TM in a neutral state;
After the internal combustion engine synchronous control is started, a rotating electric machine synchronous control is started in which the first rotating electric machine MG1 is controlled so that the rotor transmission rotation speed Nt, which is the rotation speed of the rotor transmission member T, approaches the post-shift synchronous rotation speed Ns2 based on the completion of the neutral control.
After both the internal combustion engine synchronous control and the rotating electric machine synchronous control are started,
After a first condition is satisfied, that is, the difference between the input rotational speed Ni and the rotor transmission rotational speed Nt is equal to or smaller than a specified first threshold value TH1, the first engagement device CL1 is changed from a disengaged state to an engaged state,
After the second condition is satisfied, that is, the difference between the input rotational speed Ni and the synchronous rotational speed Ns2 after the shift is equal to or less than a specified second threshold value TH2, and the difference between the rotor transmission rotational speed Nt and the synchronous rotational speed Ns2 after the shift is equal to or less than the second threshold value TH2, the transmission TM is caused to form a second gear stage.

According to this configuration, based on the completion of the disengagement control that changes the first engagement device CL1 from an engaged state to a released state, the internal combustion engine synchronous control is started to control the internal combustion engine EG so as to bring the input rotation speed Ni closer to the post-shift synchronous rotation speed Ns2. Therefore, the internal combustion engine synchronous control can be started based on the completion of the disengagement control without waiting for the completion of the neutral control that places the transmission TM in a neutral state. Also, according to this configuration, the internal combustion engine synchronous control is started before the start of the rotating electric machine synchronous control. Therefore, the internal combustion engine synchronous control can be started relatively early. Here, the internal combustion engine EG has a large inertia and it is difficult to change the rotation speed. However, as described above, according to this configuration, the internal combustion engine synchronous control can be started relatively early, so that it is easy to avoid a delay in the completion of the internal combustion engine synchronous control.
Furthermore, according to this configuration, when the first engagement device CL1 is in the disengaged state, rotating electric machine synchronous control is started to control the first rotating electric machine MG1 so as to bring the rotor transmission rotation speed Nt closer to the post-shift synchronous rotation speed Ns2. This allows the rotating electric machine synchronous control to be executed in a state in which the internal combustion engine EG is disconnected, so that the rotor transmission rotation speed Nt can be brought closer to the post-shift synchronous rotation speed Ns2 without being affected by the inertia of the internal combustion engine EG. This makes it possible to shorten the time required for the rotating electric machine synchronous control.
As described above, according to this configuration, it is possible to shorten the time required for the gear shift control to be executed when the transmission TM changes gear positions with the first engagement device CL1 in an engaged state.

In this embodiment, if the first condition (|Ni-Nt|≦TH1) is satisfied before the second condition (|Ni-Ns2|≦TH2 and |Nt-Ns2|≦TH2) is satisfied, the control device 10 changes the first engagement device CL1 from a disengaged state to an engaged state before causing the transmission TM to establish the second gear.

With this configuration, even if the change in rotation speed of the internal combustion engine EG in the internal combustion engine synchronous control is delayed relative to the change in rotation speed of the first rotating electric machine MG1 in the rotating electric machine synchronous control, the change in rotation speed of the internal combustion engine EG can be promoted by the driving force transmitted from the first rotating electric machine MG1 to the internal combustion engine EG via the first engagement device CL1 in the engaged state. This makes it easier to avoid delays in the completion of the internal combustion engine synchronous control. Therefore, the time required for the gear shift control can be kept short.

Furthermore, in the above configuration, the second gear ratio is a gear ratio smaller than that of the first gear ratio,
It is preferable that the control device 10 changes the first engagement device CL1 from a disengaged state to an engaged state when the rotor transmission rotational speed Nt is higher than the input rotational speed Ni and the above-mentioned first condition (|Ni-Nt|≦TH1) is satisfied.

With this configuration, the driving force transmitted from the internal combustion engine EG to the first rotating electric machine MG1 via the engaged first engagement device CL1 can promote changes in the rotational speed of the first rotating electric machine MG1. This makes it easier to avoid delays in the completion of the rotating electric machine synchronous control. Therefore, the time required for the gear shift control can be kept short.

In this embodiment, the disengagement control includes an internal combustion engine driving force control for causing the driving force of the internal combustion engine EG to approach a target driving force Te of the internal combustion engine synchronization control,
The execution period of the internal combustion engine driving force control and the execution period of the driving force reduction control are made to overlap.
In this embodiment, the target driving force Te is a value close to zero, and is a value that can bring the input rotation speed Ni close to the post-shift synchronous rotation speed Ns2 in the internal combustion engine synchronization control.

According to this configuration, in the disengagement control, the first engagement device CL1 is changed from an engaged state to a released state, and the driving force of the internal combustion engine EG is made to approach the target driving force Te of the internal combustion engine synchronous control, thereby making it possible to prevent the rotation speed of the internal combustion engine EG from excessively increasing after the disengagement control is completed.
Furthermore, according to this configuration, the disengagement control including the internal combustion engine driving force control and the driving force reduction control can be executed in parallel. This makes it possible to advance the start timing of the neutral control based on the completion of the disengagement control and the driving force reduction control. As a result, the time required for the gear shift control can be shortened.

In addition, in this embodiment, the control device 10 starts the internal combustion engine synchronization control after the completion of the disengagement control and before the start of the neutral control.

With this configuration, the internal combustion engine synchronous control can be started before the neutral control, which is the condition for starting the rotating electric machine synchronous control, starts, making it easier to avoid delays in the completion of the internal combustion engine synchronous control. Therefore, the time required for the gear shift control can be kept short.

Below, the shift control by the control device 10 will be explained with reference to Figures 5 and 6.

Figure 5 is a flowchart showing an example of gear shift control when the first engagement device CL1 is engaged and the transmission TM performs an upshift.

As shown in FIG. 5, first, the control device 10 determines whether the current operating mode of the vehicle drive device 100 is the first HV mode (step #1). In this example, the main control unit 11 makes the above determination by determining whether the internal combustion engine EG is in a driving state via the internal combustion engine control unit 12, whether the first rotating electric machine MG1 is in a powering state via the first rotating electric machine control unit 13, and whether the first engagement device CL1 and the second engagement device CL2 are in an engaged state and the third engagement device CL3 forms the first gear stage (low gear stage) via the engagement control unit 15.

When the control device 10 determines that the current operating mode of the vehicle drive device 100 is not the first HV mode (step #1: No), the control device 10 ends the control. On the other hand, when the control device 10 determines that the current operating mode of the vehicle drive device 100 is the first HV mode (step #1: Yes), the control device 10 determines whether there is a request to switch to the second HV mode (step #2). In this example, the main control unit 11 makes the above determination based on the charge amount of the storage device BT calculated based on the detection signal of the SOC sensor Se1, the vehicle speed calculated based on the detection signal of the vehicle speed sensor Se2, the accelerator opening calculated based on the detection signal of the accelerator operation amount sensor Se3, the brake pedal operation amount calculated based on the detection signal of the brake operation amount sensor Se4, and the shift position calculated based on the detection signal of the shift position sensor Se5.

When there is a request to transition to the second HV mode (step #2: Yes), the control device 10 starts control to reduce the driving force of the driving force source of the first wheel W1 (step #3). This control includes driving force reduction control to bring the driving force of the first rotating electric machine MG1 closer to zero, and internal combustion engine driving force control to bring the driving force of the internal combustion engine EG closer to the target driving force Te. Note that the driving force reduction control and the internal combustion engine driving force control do not need to be started at the same time, and may be started at different times. In this example, the driving force reduction control is executed after the internal combustion engine driving force control is completed.

Then, the control device 10 executes disengagement control to change the first engagement device CL1 from an engaged state to a disengaged state (step #4). In this example, the control device 10 executes the above-mentioned internal combustion engine driving force control in synchronization with this disengagement control.

Based on the completion of the decoupling control, the control device 10 starts internal combustion engine synchronous control to control the internal combustion engine EG so as to bring the input rotation speed Ni closer to the post-shift synchronous rotation speed Ns2 (step #5).

Then, the control device 10 judges whether the control to reduce the driving force of the driving force source of the first wheel W1, which was started in step #3, has been completed (step #6). In this example, the main control unit 11 makes the above judgment by judging whether the driving force of the internal combustion engine EG has become the target driving force Te and the driving force of the first rotating electric machine MG1 has become zero.

When the control device 10 determines that the control for reducing the driving force of the driving force source of the first wheel W1 has been completed (step #6: Yes), it executes neutral control to place the transmission TM in a neutral state (step #7). In this example, the engagement control unit 15 controls the third engagement device CL3 so that the transmission TM switches from a state in which the transmission TM is in the first gear to a neutral state.

Based on the completion of neutral control, the control device 10 starts rotating electric machine synchronous control, which controls the first rotating electric machine MG1 so as to bring the rotor transmission rotation speed Nt closer to the post-shift synchronous rotation speed Ns2 (step #8).

Then, the control device 10 determines whether the difference between the input rotation speed Ni and the rotor transmission rotation speed Nt is equal to or less than a specified first threshold value TH1 (|Ni-Nt|≦TH1) (step #9).

When the control device 10 determines that the above first condition (|Ni-Nt|≦TH1) is satisfied (step #9: Yes), it changes the first engagement device CL1 from a disengaged state to an engaged state (step #10).

Then, the control device 10 determines whether the difference between the input rotation speed Ni and the post-shift synchronous rotation speed Ns2 is equal to or less than a specified second threshold value TH2, and whether the difference between the rotor transmission rotation speed Nt and the post-shift synchronous rotation speed Ns2 is equal to or less than the second threshold value TH2 (|Ni-Ns2|≦TH2 and |Nt-Ns2|≦TH2) is satisfied (step #11).

When the control device 10 determines that the above second condition (|Ni-Ns2|≦TH2 and |Nt-Ns2|≦TH2) is satisfied (step #11: Yes), it causes the transmission TM to establish the second gear (step #12). In this example, the engagement control unit 15 controls the third engagement device CL3 so that the transmission TM switches from a neutral state to a state in which the second gear is established. Then, the control device 10 ends the gear shift control.

Figure 6 is a time chart showing an example of gear shift control when the transmission TM performs an upshift while the first engagement device CL1 is engaged.

As shown in FIG. 6, first, the main control unit 11 issues a command to the engagement control unit 15 to gradually reduce the target engagement pressure (engagement pressure command) of the first engagement device CL1 from time t1 until it becomes zero at time t2 (disengagement control). As a result, the first engagement device CL1 changes from an engaged state to a released state.

In parallel with this, the internal combustion engine control unit 12 controls the internal combustion engine EG so that the driving force of the internal combustion engine EG gradually decreases from time t1 to reach the target driving force Te at time t2 (internal combustion engine driving force control). Here, the target driving force Te is set to a negative value.

Then, the internal combustion engine control unit 12 controls the internal combustion engine EG so that the input rotation speed Ni gradually decreases from time t2 and approaches the post-shift synchronous rotation speed Ns2 (internal combustion engine synchronous control). As a result, the input rotation speed Ni, which was equal to the pre-shift synchronous rotation speed Ns1, starts decreasing from time t2 so as to move away from the pre-shift synchronous rotation speed Ns1. At this time, since the first engagement device CL1 is in the disengaged state, the input rotation speed Ni decreases so as to move away from the pre-shift synchronous rotation speed Ns1, while the rotor transmission rotation speed Nt maintains the pre-shift synchronous rotation speed Ns1. Here, the pre-shift synchronous rotation speed Ns1 is the rotation speed of the input member I and the rotor transmission member T that is determined according to the rotation of the first output member O1 when the transmission TM forms the first gear stage.

The first rotating electric machine control unit 13 controls the first rotating electric machine MG1 so that the driving force of the first rotating electric machine MG1 gradually decreases from time t2 to zero at time t3 (driving force reduction control).

Between time t1 and time t3, the driving force of the first rotating electric machine MG1 becomes zero, and the target engagement pressure (engagement pressure command) of the first engagement device CL1 becomes zero, so that the driving force T1 of the first drive unit DU1 gradually decreases from time t1 and becomes zero at time t3.

After the driving force T1 of the first drive unit DU1 becomes zero, the engagement control unit 15 controls the third engagement device CL3 (neutral control) between time t3 and time t4 so that the transmission TM goes from the first gear stage (low gear stage) to a neutral state.

After the transmission TM is in the neutral state, the first rotating electric machine control unit 13 controls the first rotating electric machine MG1 so that the rotor transmission rotation speed Nt gradually decreases from time t4 and approaches the synchronous rotation speed Ns2 after the shift (rotating electric machine synchronous control). As a result, the rotor transmission rotation speed Nt, which had the same value as the synchronous rotation speed Ns1 before the shift, begins to decrease from time t4 so as to move away from the synchronous rotation speed Ns1 before the shift.

After that, the rotor transmission rotation speed Nt approaches the input rotation speed Ni, and at time t5, the difference between the input rotation speed Ni and the rotor transmission rotation speed Nt becomes equal to or less than the first threshold value TH1 (|Ni-Nt|≦TH1). In this embodiment, based on this, the main control unit 11 issues a command to the engagement control unit 15 to gradually increase the target engagement pressure (engagement pressure command) of the first engagement device CL1 from time t5 so that the first engagement device CL1 changes from a released state to an engaged state.

As the first engagement device CL1 enters an engaged state, the input rotation speed Ni and the rotor transmission rotation speed Nt decrease together, and at time t6, the difference between the input rotation speed Ni and the post-shift synchronous rotation speed Ns2 becomes equal to or less than the second threshold value TH2, and the difference between the rotor transmission rotation speed Nt and the post-shift synchronous rotation speed Ns2 becomes equal to or less than the second threshold value TH2 (|Ni-Ns2|≦TH2, and |Nt-Ns2|≦TH2).Then, from time t6 to time t7, the engagement control unit 15 controls the third engagement device CL3 so that the transmission TM shifts from the neutral state to the second gear (high speed).

After the transmission TM has established the second gear (high speed), the internal combustion engine control unit 12 controls the internal combustion engine EG so that the driving force of the internal combustion engine EG gradually increases from time t7 to reach a specified target driving force at time t8. Furthermore, the first rotating electric machine control unit 13 controls the first rotating electric machine MG1 so that the driving force of the first rotating electric machine MG1 gradually increases from time t7 to reach a specified target driving force at time t8. Thus, in this example, after the control device 10 has the transmission TM established the second gear, it performs driving force return control to bring the driving forces of the internal combustion engine EG and the first rotating electric machine MG1 closer to their respective target driving forces.

As the driving forces of the internal combustion engine EG and the first rotating electric machine MG1 gradually increase from zero from time t7 to time t8, the driving force T1 of the first drive unit DU1 also gradually increases from zero from time t7 to time t8.

In this embodiment, the control device 10 executes driving force assist control to cause the second rotating electric machine MG2 to output a driving force so as to compensate for fluctuations in the driving force from the first rotating electric machine MG1 and the internal combustion engine EG transmitted to the first output member O1 via the transmission TM during execution of the gear shift control. In the example shown in FIG. 6, during execution of the gear shift control, the second rotating electric machine MG2 is controlled so that the sum (T3) of the driving force T1 of the first drive unit DU1 and the driving force T2 of the second drive unit DU2 is constant.

As described above, in this embodiment, the second rotating electric machine MG2 is drivingly connected to the second output member O2, which is drivingly connected to a second wheel W2 different from the first wheel W1, without going through the first output member O1. However, the second rotating electric machine MG2 may be arranged in the power transmission path between the transmission TM and the first output member O1 and drivingly connected to the first output member O1 (see FIG. 7), as will be described in detail later.

In this manner, in this embodiment, the vehicle further includes a second rotating electric machine MG2 that is drivingly connected to the second output member O2, which is drivingly connected to the second wheel W2 different from the first wheel W1, without passing through the first output member O1, or that is disposed in a power transmission path between the transmission TM and the first output member O1 and drivingly connected to the first output member O1,
While the control device 10 is executing the gear shift control, it executes driving force assist control to cause the second rotating electric machine MG2 to output a driving force so as to compensate for fluctuations in the driving force from the first rotating electric machine MG1 and the internal combustion engine EG transmitted to the first output member O1 via the transmission TM.

This configuration allows the fluctuations in driving force throughout the vehicle to be kept small while shift control is being performed.

Other embodiments
(1) In the above embodiment, the vehicle drive device 100 is described as having the first drive unit DU1 and the second drive unit DU2. However, the present invention is not limited to such a configuration, and the vehicle drive device 100 may be configured to have the first drive unit DU1 and not have the second drive unit DU2. In this case, as shown in FIG. 7, the first drive unit DU1 may be configured to have the second rotating electric machine MG2. In the example shown in FIG. 7, the second rotor gear RG2 that rotates integrally with the second rotor RT2 of the second rotating electric machine MG2 meshes with the first differential input gear 4 at a position different from the transmission output gear 3 in the circumferential direction of the first differential input gear 4 as the first output member O1. Although not shown, the second rotor gear RG2 may be configured to mesh with the transmission output gear 3. In these configurations, the second rotating electric machine MG2 is disposed in a power transmission path between the transmission TM and the first output member O1 and is drivingly connected to the first output member O1. The vehicle drive device 100 may be configured not to include the second rotating electric machine MG2.

(2) In the above embodiment, an example has been described in which the transmission TM is capable of forming one of two gear stages, a first gear stage (low gear stage) and a second gear stage (high gear stage). However, the present invention is not limited to such a configuration, and the transmission TM may be capable of forming one of three or more gear stages.

(3) In the above embodiment, the transmission TM is a parallel shaft gear type transmission. However, the present invention is not limited to such a configuration, and the transmission TM may be configured as a planetary gear type transmission.

(4) In the above embodiment, a configuration in which the first engagement device CL1 is a friction engagement device 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, for example, the first engagement device CL1 may be a meshing engagement device and the second engagement device CL2 may be a friction engagement device. Also, in the above embodiment, a configuration in which the third engagement device CL3 is a meshing engagement device has been described as an example. However, without being limited to such a configuration, the third engagement device CL3 may be a friction engagement device.

(5) In the above embodiment, the entire distribution differential gear mechanism SP, or the ring gear R1 as the third rotating element E3 of the distribution differential gear mechanism SP, is described as an example of a configuration that functions as a rotor transmission member T that rotates in response to the rotation of the first rotor RT1, but is not limited to such a configuration. For example, if the vehicle drive device 100 is configured to have a transmission gear mechanism instead of the distribution differential gear mechanism SP, the transmission gear mechanism may function as the rotor transmission member T. Even in this case, if other members that rotate in response to the rotation of the first rotor RT1, such as the first rotor gear RG1 and the idler gear IG in the above embodiment, are provided, they also function as the rotor transmission member T. In addition, the first rotor shaft RS1 of the first rotating electric machine MG1 may function as the rotor transmission member T. Also, for example, the first rotating electric machine MG1 may be disposed on the first axis X1, and the vehicle drive device 100 may be configured without including an idler gear IG, a distribution differential gear mechanism SP, a transmission gear mechanism, etc.

(6) In the above embodiment, the control device 10 has been described as being configured to change the first engagement device CL1 from a disengaged state to an engaged state before the transmission TM establishes the second gear when the first condition (|Ni-Ns2|≦TH2 and |Nt-Ns2|≦TH2) is satisfied. However, the present invention is not limited to such a configuration, and the first engagement device CL1 may be configured to change from a disengaged state to an engaged state after the transmission TM establishes the second gear.

(7) In the above embodiment, a configuration in which the second gear is a gear with a smaller gear ratio than the first gear, that is, a configuration in which gear shift control is executed when the transmission TM performs an upshift, has been described as an example. However, the present invention is not limited to such a configuration, and the second gear may be a gear with a larger gear ratio than the first gear, that is, a configuration in which gear shift control is executed when the transmission TM performs a downshift.

(8) In the above embodiment, an example has been described in which the execution period of the internal combustion engine driving force control, which brings the driving force of the internal combustion engine EG closer to the target driving force Te of the internal combustion engine synchronous control, overlaps with the execution period of the driving force reduction control, which brings the driving force of the first rotating electric machine MG1 closer to zero. However, the present invention is not limited to such a configuration, and the execution period of the internal combustion engine driving force control and the execution period of the driving force reduction control do not have to overlap. Also, a configuration in which the internal combustion engine driving force control is not executed may be used.

(9) In the above embodiment, a configuration has been described as an example in which driving force assist control is performed to cause the second rotating electric machine MG2 to output a driving force so as to compensate for fluctuations in the driving force from the first rotating electric machine MG1 and the internal combustion engine EG transmitted to the first output member O1 via the transmission TM during execution of the shift control. However, the present invention is not limited to such a configuration, and may be configured not to execute driving force assist control. Furthermore, even when driving force assist control is executed, it is not limited to compensating for all of the fluctuations in the driving force from the first rotating electric machine MG1 and the internal combustion engine EG during execution of the shift control by the driving force of the second rotating electric machine MG2, and it may be possible to compensate for only a portion of the fluctuations by the driving force of the second rotating electric machine MG2.

(10) The configurations disclosed in each of the above-described embodiments may be combined with configurations disclosed in other embodiments, provided no contradictions arise. With respect to other configurations, the embodiments disclosed in this specification are merely illustrative in all respects. Therefore, various modifications may be made as appropriate within the scope of the spirit of this disclosure.

The technology disclosed herein can be used in a vehicle drive device that includes an input member that is drivingly connected to an internal combustion engine, an output member that is drivingly connected to wheels, a rotating electric machine with a rotor, a rotor transmission member that rotates in response to the rotation of the rotor, a disconnecting engagement device that connects and disconnects the power transmission between the input member and the rotor transmission member, and a transmission provided in the power transmission path between the rotor transmission member and the output member.

100: Vehicle drive device, 10: Control device, I: Input member, O1: First output member, MG1: First rotating electric machine, RT1: First rotor (rotor), T: Rotor transmission member, CL1: First engagement device (disengagement engagement device), TM: Transmission, EG: Internal combustion engine, W1: First wheel

Claims (5)

an input member drivingly connected to the internal combustion engine;
a first output member drivingly connected to the first wheel;
a first rotating electric machine including a rotor;
a rotor transmission member that rotates in response to rotation of the rotor;
a disconnection engagement device that connects and disconnects power transmission between the input member and the rotor transmission member;
a transmission provided in a power transmission path between the rotor transmission member and the first output member;
a control device that controls the internal combustion engine, the first rotating electric machine, the disengagement engagement device, and the transmission,
The transmission is configured to be selectively switched between a state in which any one of a plurality of gear stages including a first gear stage and a second gear stage having a gear ratio different from that of the first gear stage is formed, or a neutral state in which none of the gear stages is formed,
The control device executes a gear shift control when the disengagement engagement device is in an engaged state and the transmission switches from a state in which the first gear stage is formed to a state in which the second gear stage is formed,
When the transmission is in the second gear position, the rotational speeds of the input member and the rotor transmission member, which are determined in accordance with the rotation of the first output member, are defined as post-gear-shift synchronous rotational speeds,
In the gear shift control,
performing a disengagement control for changing the disengagement engagement device from an engaged state to a released state, and a driving force reduction control for reducing the driving force of the first rotating electric machine to near zero;
starting an internal combustion engine synchronization control for controlling the internal combustion engine so as to bring the rotational speed of the input member closer to the post-shift synchronous rotational speed based on the completion of the disengagement control;
starting a neutral control for placing the transmission in the neutral state based on completion of both the driving force reduction control and the disengagement control;
starting a rotating electric machine synchronous control for controlling the first rotating electric machine so as to bring the rotational speed of the rotor transmission member closer to the post-shift synchronous rotational speed based on completion of the neutral control after the start of the internal combustion engine synchronous control;
After both the internal combustion engine synchronous control and the rotating electric machine synchronous control are started,
changing the disconnecting engagement device from a released state to an engaged state after a first condition is satisfied in which a difference between a rotational speed of the input member and a rotational speed of the rotor transmission member is equal to or smaller than a specified first threshold value;
a vehicle drive device that causes the transmission to form the second gear stage after a second condition is satisfied in which a difference between the rotational speed of the input member and the post-shift synchronous rotational speed is equal to or less than a specified second threshold value, and a difference between the rotational speed of the rotor transmission member and the post-shift synchronous rotational speed is equal to or less than the second threshold value. The vehicle drive device according to claim 1, wherein the control device changes the disengagement engagement device from a disengaged state to an engaged state before the transmission is caused to establish the second gear stage when the first condition is satisfied before the second condition is satisfied. The second gear ratio is a gear ratio that is smaller than that of the first gear ratio,
3. The vehicle drive device according to claim 2, wherein the control device changes the disengagement engagement device from a released state to an engaged state when the first condition is satisfied in a state in which the rotational speed of the rotor transmission member is higher than the rotational speed of the input member. the disconnection control includes an internal combustion engine driving force control for approximating a driving force of the internal combustion engine to a target driving force of the internal combustion engine synchronization control,
The vehicle drive system according to claim 1 , wherein an execution period of the internal combustion engine driving force control and an execution period of the driving force reduction control are made to overlap with each other. a second rotating electric machine that is drivingly connected to a second output member that is drivingly connected to a second wheel different from the first wheel without passing through the first output member, or that is disposed in a power transmission path between the transmission and the first output member and drivingly connected to the first output member,
5. The vehicle drive device according to claim 1, wherein the control device executes driving force assist control to cause the second rotating electric machine to output a driving force so as to compensate for fluctuations in the driving force from the first rotating electric machine and the internal combustion engine transmitted to the first output member via the transmission during execution of the gear shift control.

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