JP2023080705A - Vehicular driving device - Google Patents

Abstract

To provide a vehicular driving device which can reduce differential rotation of a pair of engagement elements in an engagement device for connecting and disconnecting power transmission between an input member drive-connected to an internal combustion engine and a differential gear mechanism when starting the internal combustion engine in a configuration provided with the differential gear mechanism having three rotation elements.SOLUTION: A control device can execute first transfer control when transferring from a first mode to a second mode. The first transfer control includes: first control in which a second engagement device for connecting and disconnecting power transmission between two rotation elements of three rotation elements in a differential gear mechanism is changed from a direct coupling engagement state to a slip engagement state while maintaining a transmission mechanism in a state for performing power transmission; second control in which a first engagement device is changed from a release state to a slip engagement state after the first control; and third control in which an internal combustion engine is started by torque transmitted to the internal combustion engine from the differential gear mechanism side through the first engagement device in the slip engagement state while maintaining the second engagement device in the slip engagement state after the second control.SELECTED DRAWING: Figure 6

Description

The present invention relates to a vehicular drive system that performs control for starting an internal combustion engine by torque transmitted from a rotating electrical machine to the internal combustion engine while keeping a friction engagement device in a slipping engagement state.

Patent Document 1 below discloses a rotary electric machine (MG) having a rotor, an input member (I) connected to rotate integrally with the rotor, and an output member ( O), a transmission (TM) that changes the speed of the rotation of the input member (I) and transmits it to the output member (O), and between the output shaft (Eo) of the internal combustion engine (ENG) and the input member (I) and a disconnecting engagement device (CL1) for connecting and disconnecting power transmission (see FIG. 1 of Patent Document 1). The transmission (TM) includes a shift engagement device (CL2) that forms a gear stage according to the state of engagement. Each of the engagement device for disconnection (CL1) and the engagement device for speed change (CL2) is a friction engagement device. Reference numerals shown in parentheses in the description of the background art are those of Patent Document 1.

In the above-described vehicle drive system (1), torque transmitted from the rotary electric machine (MG) to the internal combustion engine (ENG) through the disengagement engagement device (CL1) in the slip engagement state causes the internal combustion engine (ENG) to ) is executed. In this control, by changing the engagement device for gear shift (CL2) from the direct engagement state to the slip engagement state, transmission of torque fluctuation accompanying the start of the internal combustion engine (ENG) to the output member (O) is controlled. avoiding.

WO2016/084474

In the vehicle drive system (1) of Patent Document 1, when the control for starting the internal combustion engine (ENG) as described above is executed, the shift engagement device (CL2) shifts from the direct engagement state to the slip engagement state. Since the rotation speed of the input member (I) increases with the change, the differential rotation between the pair of engagement elements of the disconnecting engagement device (CL1) in the slip engagement state tends to increase. As a result, the amount of heat generated by the disconnecting engagement device (CL1) tends to increase. In addition, it tends to take a long time for the rotational speed of the internal combustion engine (ENG) to reach a rotational speed at which the disconnecting engagement device (CL1) can be directly engaged.

By the way, in addition to the vehicle drive device of Patent Document 1, 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 that includes a rotor, a first rotating element, a second rotating and a third rotating element, wherein the first rotating element is drivingly connected to the input member and the third rotating element is drivingly connected to the rotor; between the input member and the first rotating element; A first engagement device for connecting and disconnecting power transmission, and a second engagement for connecting and disconnecting power transmission between two selected from the three rotating elements of the first rotating element, the second rotating element, and the third rotating element. a coupling device, and a third engagement device for connecting and disconnecting power transmission between the second rotating element and the output member, and a transmission mechanism for performing power transmission between at least the second rotating element and the output member. Other vehicle drives are also known.

When the control for starting the internal combustion engine in Patent Document 1 is applied to such a vehicle drive system, the third engagement device as the friction engagement device provided in the transmission mechanism is changed from the direct engagement state to the slip engagement state. state, the first engagement device as a friction engagement device is changed from the released state to the slip engagement state, and torque transmitted from the rotary electric machine to the internal combustion engine via the first engagement device causes the It is conceivable to execute control for starting the internal combustion engine. In this case, as with the vehicle drive system of Patent Document 1, a problem arises in that the differential rotation between the pair of engagement elements of the first engagement device in the slip engagement state tends to increase.

Therefore, in a configuration provided with a differential gear mechanism having three rotating elements, when starting the internal combustion engine, a connection for connecting and disconnecting power transmission between an input member drivingly connected to the internal combustion engine and the differential gear mechanism is provided. It is desired to realize a vehicle drive system capable of suppressing a differential rotation between a pair of engaging elements of a coupling device.

In view of the above, the characteristic configuration of the vehicle drive system is as follows.
an input member drivingly connected to an internal combustion engine;
an output member drivingly connected to the wheel;
a rotating electric machine having a rotor;
a differential gear mechanism comprising a first rotating element, a second rotating element, and a third rotating element, wherein the first rotating element is drivingly connected to the input member and the third rotating element is drivingly connected to the rotor; ,
a first engaging device for connecting and disconnecting power transmission between the input member and the first rotating element;
a second engaging device for connecting and disconnecting power transmission between two selected from three rotating elements of the first rotating element, the second rotating element, and the third rotating element;
a transmission mechanism that includes a third engagement device that connects and disconnects power transmission between the second rotating element and the output member, and that performs power transmission between at least the second rotating element and the output member;
A vehicle drive device comprising: a control device that controls the internal combustion engine, the rotating electric machine, the first engagement device, the second engagement device, and the third engagement device,
each of the first engagement device, the second engagement device, and the third engagement device is a frictional engagement device;
A first mode and a second mode are provided as operation modes,
A state in which the pair of engaging elements of the friction engagement device are engaged without differential rotation is referred to as a direct engagement state, and a state in which the pair of engaging elements are engaged with differential rotation is referred to as a slip engagement state. A engaged state is defined as a state in which the pair of engaging elements are not engaged is defined as a released state,
In the first mode, the first engagement device is in the released state, the second engagement device is in the direct engagement state, and the transmission mechanism is in a state of transmitting power, and the internal combustion engine does not output torque. a stopped state, the torque of the rotating electrical machine is transmitted to the output member,
In the second mode, the first engagement device is in the directly engaged state, the second engagement device is in the released state or the directly engaged state, the transmission mechanism is in a state of transmitting power, and the internal combustion engine Torque of the engine and the rotating electric machine is transmitted to the output member,
The control device is capable of executing first transition control when transitioning from the first mode to the second mode,
The first transition control is
a first control for changing the second engagement device from the direct engagement state to the slip engagement state while maintaining the power transmission state of the transmission mechanism;
a second control for changing the first engagement device from the released state to the slip engagement state after the first control;
After the second control, while maintaining the second engagement device in the slip engagement state, the internal combustion engine is operated from the differential gear mechanism side via the first engagement device in the slip engagement state. and a third control for starting the internal combustion engine by the torque transmitted to.

According to this characteristic configuration, by changing the second engagement device from the direct engagement state to the slip engagement state in the first control, the rotational speed of the first rotary element driven and connected to the input member is reduced to the second speed. It is lower than the rotational speed of the rotating element and the third rotating element. As a result, the internal combustion engine can be started more efficiently than when control is executed to change the third engagement device from the direct engagement state to the slip engagement state while maintaining the second engagement device in the direct engagement state. Therefore, the differential rotation between the pair of engaging elements of the first engaging device that are in the slip engaged state can be suppressed. As a result, the amount of heat generated by the first engaging device can be kept small. Further, it is possible to shorten the time required for the rotation speed of the internal combustion engine to reach the rotation speed at which the first engagement device can be directly engaged.
Further, according to this characteristic configuration, by changing the second engagement device from the direct engagement state to the slip engagement state in the first control, after the internal combustion engine has been started in the third control, the differential gear The torque of the internal combustion engine and the torque of the rotating electrical machine, which are transmitted to the differential gear mechanism, can be combined and transmitted to the output member in a state where the three rotating elements of the mechanism have differential rotations. As a result, torque can be transmitted to the output member immediately after the start of the internal combustion engine is completed.
Further, according to this characteristic configuration, in order to start the internal combustion engine while maintaining the second engagement device in the slip engagement state in the third control, a change in rotation of the input member accompanying the start of the internal combustion engine is transmitted to the output member. can be avoided.

A skeleton diagram of a first drive unit of the vehicle drive system according to the embodiment. A skeleton diagram of a second drive unit of the vehicle drive system according to the embodiment. 1 is a control block diagram of a vehicle drive system according to an embodiment; FIG. 4 is a diagram showing the state of each engagement device in each operation mode of the vehicle drive system according to the embodiment; A flow chart showing an example of control processing of the control device when the operation mode of the vehicle drive system according to the embodiment is shifted from the first mode to the second mode. Flowchart showing an example of first transition control according to the embodiment Flowchart showing an example of second transition control according to the embodiment Time chart showing an example of first transition control according to the embodiment Time chart showing an example of second transition control according to the embodiment A skeleton diagram of a first drive unit of a vehicle drive system according to another embodiment.

A vehicle drive system 100 according to an embodiment will be described below with reference to the drawings. As shown in FIGS. 1 and 2, in the present embodiment, the vehicle drive system 100 includes a first drive unit DU1 that drives a pair of first wheels W1 and a second drive unit DU1 that drives a pair of second wheels W2. and a unit DU2. In this embodiment, the first wheel W1 is the front wheel of the vehicle and the second wheel W2 is the rear wheel of the vehicle.

As shown in FIG. 1, 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 distribution differential gear mechanism SP, a first engagement device CL1, a second engagement device CL2, and a transmission mechanism T are provided. In this embodiment, the first drive unit DU1 further includes a first output differential gear mechanism DF1, a first gear 21, a second gear 22, a third gear 23, and a fourth gear 24. ing.

Here, in the present application, the term “driving connection” refers to a state in which two rotating elements are connected so as to be able to transmit a driving force, and the two rotating elements are connected so as to rotate integrally. It includes a state in which two rotating elements are connected so as to be able to transmit driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at different speeds, such as shafts, gear mechanisms, belts, and chains. The transmission member may include an engagement device for selectively transmitting rotation and driving force, such as a friction engagement device and a mesh type engagement device. However, when each rotating element of the differential gear mechanism is referred to as "driving connection", it refers to a state in which a plurality of rotating elements in the differential gear mechanism are connected to each other without interposing other rotating elements. .

In this embodiment, the input member I, the first engagement device CL1, and the first gear 21 are arranged on the first axis X1 as the rotational axis of the output shaft ES of the internal combustion engine EG. The distributing differential gear mechanism SP, the transmission mechanism T, the second engagement device CL2, the second gear 22, the third gear 23, and the fourth gear 24 are arranged on the second axis X2 different from the first axis X1. are placed in Furthermore, the first rotary electric machine MG1, the first output member O1, and the first output differential gear mechanism DF1 are arranged on a third axis X3 different from the first axis X1 and the second axis X2.

As shown in FIG. 2, in the present embodiment, the second drive unit DU2 includes a second rotating electrical machine MG2, a second output member O2 drivingly connected to the second wheel W2, a counter gear mechanism CG, and a second and an output differential gear mechanism DF2.

In this embodiment, the second rotating electric machine MG2 is arranged on the fourth axis X4 different from the first axis X1 to the third axis X3. The counter gear mechanism CG is arranged on the fifth axis X5 different from the first axis X1 to the fourth axis X4. Further, the second output member O2 and the second output differential gear mechanism DF2 are arranged on a sixth axis X6 different from the first axis X1 to the fifth axis X5.

In this example, the axes X1 to X6 are arranged parallel to each other. In the following description, the direction parallel to the axes X1 to X6 is defined as the "axial direction L" of the vehicle drive device 100. As shown in FIG. One side in the axial direction L is referred to as "first axial side L1", and the other side in the axial direction L is referred to as "second axial side L2". In this embodiment, in the axial direction L, the side on which the input member I is arranged with respect to the internal combustion engine EG is defined as the first axial side L1, and the opposite side is defined as the second axial side L2. Further, a direction orthogonal to each of the axes X1 to X6 is defined as a "radial direction R" with respect to each axis. When there is no need to distinguish which axis should be used as a reference, or when it is clear which axis should be used as a reference, the term "radial direction R" may simply be used.

As shown in FIG. 1, in this embodiment, the input member I is an input shaft 1 extending along the axial direction L. As shown in FIG. The input shaft 1 is drivingly connected to the output shaft ES of the internal combustion engine EG via a damper device DP that damps fluctuations in transmitted torque. The internal combustion engine EG is a prime mover (gasoline engine, diesel engine, etc.) that is driven by combustion of fuel to take out power. 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 wheels W1. The first rotary electric machine MG1 has a function as a motor (electric motor) that receives power supply and generates power, and a function as a generator (generator) that receives power supply and generates power. . Specifically, the first rotating electric machine MG1 is electrically connected to the power storage device BT (see FIG. 3) such as a battery or a capacitor so as to transfer electric power to and from the power storage device BT. Then, the first rotating electrical machine MG1 is powered by the electric power stored in the power storage device BT to generate driving force. In addition, the first rotary electric machine MG1 generates 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 power 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 (for example, a case that houses the first rotating electric machine MG1 and the like). The first rotor RT1 is rotatably supported with respect to the first stator ST1. In this embodiment, the first rotor RT1 is arranged inside in the radial direction R with respect to the first stator ST1.

In this embodiment, a first rotor gear RG1 is coupled to the first rotor RT1 via a first rotor shaft RS1 extending along the axial direction L so as to rotate integrally therewith. there is In this embodiment, the first rotor gear RG1 is arranged on the third axis X3. In the example shown in FIG. 1, the first rotor gear RG1 is arranged on the first axial side L1 of the first rotor RT1.

The distribution differential gear mechanism SP is a "differential gear mechanism" including a first rotary element E1, a second rotary element E2, and a third rotary element E3. The first rotating element E1 is drivingly connected to the input member I. As shown in FIG. The third rotating element E3 is drivingly connected to rotate in conjunction with the first rotor RT1. In this embodiment, the second rotating element E2 is drivingly connected via the transmission mechanism T to the first output member O1.

In this embodiment, the order of rotation speed of the rotating elements of the distribution differential gear mechanism SP is the order of the first rotating element E1, the second rotating element E2, and the third rotating element E3. Here, "the order of rotational speed" means the order of rotational speed in the rotating state of each rotating element. The rotation speed of each rotating element changes depending on the rotation state of the differential gear mechanism (here, the planetary gear mechanism), but the order of high and low rotation speeds of each rotating element is determined by the structure of the differential gear mechanism. is constant because

Further, in this embodiment, the distribution differential gear mechanism SP is a planetary gear mechanism including a first sun gear S1, a first carrier C1, and a first ring gear R1. In this embodiment, the first rotating element E1 is the first ring gear R1. And the second rotating element E2 is the first carrier C1. Also, the third rotating element E3 is the first sun gear S1. In this example, the distributing differential gear mechanism SP includes a first carrier C1 that supports the first pinion gear P1, a first sun gear S1 that meshes with the first pinion gear P1, and a radial direction R with respect to the first sun gear S1. It is a single pinion type planetary gear mechanism including a first ring gear R1 that is arranged outside and meshes with the first pinion gear P1.

In this embodiment, the first ring gear R1 is connected to the second gear 22 so as to rotate integrally therewith. In this embodiment, the second gear 22 is arranged outside in the radial direction R with respect to the first ring gear R1. The second gear 22 is drivingly connected to the first gear 21 via a first idler gear 31 arranged on a different axis from the first to third axes X1 to X3. That is, in the present embodiment, the first gear 21 and the second gear 22 mesh with the first idler gear 31 at different positions in the circumferential direction of the first idler gear 31 . Thus, the first gear 21 and the second gear 22 are connected through the first idler gear 31 so as to rotate in conjunction with each other. In FIG. 1, dashed-dotted lines connecting gears indicate that the gears are in mesh with each other.

Further, in this embodiment, the first sun gear S1 is connected to the third gear 23 so as to rotate integrally therewith. In this embodiment, the third gear 23 meshes with the first rotor gear RG1. The third gear 23 is arranged on the first side L1 in the axial direction with respect to the distribution differential gear mechanism SP.

The first engagement device CL1 is configured to connect and disconnect power transmission between the input member I and the first rotating element E1. In this embodiment, the first engagement device CL1 connects and disconnects power transmission between the input member I and the first gear 21 . Further, in the present embodiment, the first engagement device CL1 is arranged adjacent to the first gear 21 on the second side L2 in the axial direction.

The second engaging device CL2 is configured to connect and disconnect power transmission between two selected from three rotating elements of the first rotating element E1, the second rotating element E2, and the third rotating element E3. ing. In this embodiment, the second engagement device CL2 connects and disconnects power transmission between the first ring gear R1 as the first rotating element E1 and the first carrier C1 as the second rotating element E2. Further, in the present embodiment, the second engaging device CL2 is arranged adjacent to the second axial side L2 with respect to the distributing differential gear mechanism SP. The second engagement device CL2 is arranged adjacent to the transmission mechanism T on the first side L1 in the axial direction.

Each of the first engagement device CL1 and the second engagement device CL2 is a friction engagement device. Therefore, each of the first engagement device CL1 and the second engagement device CL2 includes a pair of engagement elements that selectively engage with each other, and the engagement pressure of the pair of engagement elements increases. state is controlled. The engagement state of the friction engagement device includes a direct engagement state, a slip engagement state, and a released state. The direct engagement state is a state in which a pair of engagement elements of the friction engagement device are engaged without differential rotation. The slip engagement state is a state in which a pair of engagement elements of the friction engagement device are engaged with differential rotation. The released state is a state in which the pair of engaging elements of the friction engagement device are not engaged.

The transmission mechanism T is configured to perform power transmission between at least the second rotating element E2 and the first output member O1. The transmission mechanism T includes a third engagement device CL3. In this embodiment, the transmission mechanism T functions as a transmission capable of selectively forming a plurality of gear stages with different gear ratios according to the engagement state of the third engagement device CL3. Therefore, in the present embodiment, the transmission mechanism T shifts the rotation transmitted from the second rotating element E2 at a gear ratio corresponding to the gear stage formed among the plurality of gear stages to shift the rotation to the first output member O1. to the side of

In this embodiment, the transmission mechanism T is a planetary gear transmission including a planetary gear mechanism PG. The planetary gear mechanism PG includes a second sun gear S2, a second carrier C2, and a second ring gear R2. In this embodiment, the planetary gear mechanism PG includes a second carrier C2 that supports the second pinion gear P2, a second sun gear S2 that meshes with the second pinion gear P2, and a It is a single pinion type planetary gear mechanism provided with a second ring gear R2 that is arranged and meshes with the second pinion gear P2.

In this embodiment, the second ring gear R2 is connected to rotate integrally with the first carrier C1. Also, the second carrier C2 is connected to the fourth gear 24 so as to rotate integrally therewith.

The third engagement device CL3 is configured to connect and disconnect power transmission between the second rotating element E2 (here, the first carrier C1) and the first output member O1. The third engagement device CL3 is a friction engagement device. In this embodiment, the third engagement device CL3 includes a shift clutch Ct and a shift brake Bt. Each of the shift clutch Ct and the shift brake Bt is a friction engagement device.

The transmission clutch Ct is configured to connect and disconnect power transmission between the second ring gear R2 and the second carrier C2. In this embodiment, the transmission clutch Ct is arranged adjacent to the planetary gear mechanism PG on the axial second side L2. The transmission clutch Ct is arranged adjacent to the fourth gear 24 on the axial first side L1.

The shift brake Bt is configured to selectively fix the second sun gear S2 to a non-rotating member (for example, a case accommodating the transmission mechanism T and the like). Further, in the present embodiment, the shift brake Bt is arranged adjacent to the fourth gear 24 on the second side L2 in the axial direction.

In the present embodiment, when the shift clutch Ct is in the released state and the shift brake Bt is in the directly engaged state, the first shift stage (low speed stage) with a relatively large gear ratio is established. Further, when the shift clutch Ct is in the directly engaged state and the shift brake Bt is in the released state, the second shift stage (high speed stage) with a relatively small gear ratio is established. Note that when both the gear shift clutch Ct and the gear shift brake Bt are in the released state, none of the gear stages are formed. That is, in this embodiment, the transmission mechanism T is configured to be switchable to a neutral state in which power is not transmitted between the distribution differential gear mechanism SP and the first output differential gear mechanism DF1.

The first output differential gear mechanism DF1 is configured to distribute the rotation of the first output member O1 to the pair of wheels W. As shown in FIG. In this embodiment, the first output member O1 is the first differential input gear 4 that is the input element of the first output differential gear mechanism DF1. In this embodiment, the first differential input gear 4 is drivingly connected to the fourth gear 24 via a second idler gear 32 arranged on a separate axis from the first to third axes X1 to X3. . That is, in the present embodiment, the first differential input gear 4 and the fourth gear 24 mesh with the second idler gear 32 at different positions in the circumferential direction of the second idler gear 32 . In this way, the first differential input gear 4 and the fourth gear 24 are connected through the second idler gear 32 so as to rotate in conjunction with each other.

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 differential case, a pinion shaft supported to rotate integrally with the differential case, and a pinion shaft rotatable with respect to the pinion shaft. and a pair of side gears meshing with the pair of differential pinion gears and functioning as distribution output elements. The differential case accommodates a pinion shaft, a pair of differential pinion gears, and a pair of side gears.

In this embodiment, the first differential input gear 4 as the first output member O1 is connected to the differential case so as to protrude outward in the radial direction R from the differential case. A first drive shaft DS1 drivingly connected to the first wheel W1 is rotatably connected to each of the pair of side gears. Thus, in the present embodiment, the first output differential gear mechanism DF1 rotates the first differential input gear 4 as the first output member O1 via the pair of first drive shafts DS1. Distribute to wheel W1. In the example shown in FIG. 1, the first output differential gear mechanism DF1 is arranged on the second side L2 in the axial direction with respect to the first rotary electric machine MG1. A drive shaft DS on the first side L1 in the axial direction is arranged so as to pass inside in the radial direction R with respect to a first rotor shaft RS1 formed in a cylindrical shape having an axis along the axial direction L. .

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

The second rotating electrical machine MG2 includes a second stator ST2 and a second rotor RT2. The second stator ST2 is fixed to a non-rotating member (for example, a case that houses the second rotating electric machine MG2 and the like). The second rotor RT2 is rotatably supported with respect to the second stator ST2. In this embodiment, the second rotor RT2 is arranged inside in the radial direction R with respect to the second stator ST2.

In this embodiment, a second rotor gear RG2 is coupled to the second rotor RT2 via a second rotor shaft RS2 formed to extend along the axial direction L so as to rotate integrally with the second rotor RT2. there is In this embodiment, the second rotor gear RG2 is arranged on the fourth axis X4. In the example shown in FIG. 2, the second rotor gear RG2 is arranged on the axial first side L1 relative to 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 connecting these gears 61 and 62 so as to rotate integrally.

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 the output element of the counter gear mechanism CG. In the example shown in FIG. 2 , the counter output gear 62 is arranged on the second axial side L2 relative to the counter input gear 61 . Also, the counter output gear 62 is formed to have 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 the pair of second wheels W2. In this embodiment, the second output member O2 is the 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, and the second pinion shaft. A pair of second pinion gears rotatably supported on a two-pinion shaft, and a pair of second side gears meshing with the pair of second pinion gears and functioning as distribution output elements are provided. The second differential case houses a second pinion shaft, a pair of second pinion gears, and a pair of second side gears.

In this embodiment, the second differential input gear 7 as the second output member O2 is connected to the second differential case so as to protrude outward in the radial direction R from the second differential case. . A second drive shaft DS2 drivingly connected to the second wheel W2 is rotatably connected to each of the pair of second side gears. Thus, in this embodiment, the second output differential gear mechanism DF2 rotates the second differential input gear 7 as the second output member O2 via the pair of second drive shafts DS2. Distribute to wheel W2.

As shown in FIG. 3, the vehicle drive system 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 second engagement device CL2. 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 A second rotary electric machine control unit 14 that controls the MG2, and an engagement control unit 15 that controls the states of engagement of the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3. I have.

The main control unit 11 controls the internal combustion engine control unit 12, the first rotating electrical machine control unit 13, the second rotating electrical machine control unit 14, and the engagement control unit 15, respectively. Output commands. The internal combustion engine control unit 12 controls the internal combustion engine EG so that the internal combustion engine EG outputs the command torque commanded from the main control unit 11 or reaches the command rotation speed commanded from the main control unit 11. do. The first rotary electric machine control unit 13 causes the first rotary electric machine MG1 to output the command torque commanded from the main control unit 11 or achieve the command rotation speed commanded from the main control unit 11. It controls the single-rotation electric machine MG1. The second rotating electrical machine control unit 14 controls the second rotating electrical machine MG2 to output the command torque commanded from the main control unit 11 or to achieve the command rotation speed commanded from the main control unit 11. It controls the two-rotating electric machine MG2. The engagement control unit 15 controls the first engagement device CL<b>1 , the second engagement device CL<b>2 , and the third engagement device CL<b>3 to be in the engagement state instructed by the main control unit 11 . Actuators (not shown) for operating the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3 are controlled.

Further, the main control unit 11 is configured to be able to acquire information from sensors provided in each part of the vehicle in order to acquire information of each part of the vehicle in which the vehicle drive device 100 is mounted. In this embodiment, the main control unit 11 can acquire information from the SOC sensor Se1, the input rotation speed sensor Se2, the output rotation speed sensor Se3, the accelerator operation amount sensor Se4, the brake operation amount sensor Se5, and the shift position sensor Se6. is configured to

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

The input rotation speed sensor Se2 is a sensor for detecting an input rotation speed Ni, which is the rotation speed of the input member I. As shown in FIG. The main control section 11 calculates the input rotation speed Ni based on the detection signal of the input rotation speed sensor Se2.

The output rotation speed sensor Se3 is a sensor for detecting the output rotation speed, which is the rotation speed of the first output member O1. The main control section 11 calculates the output rotation speed based on the detection signal of the output rotation speed sensor Se3. Here, the output rotation speed is proportional to the running speed (vehicle speed) of the vehicle in which the vehicle drive system 100 is mounted. Therefore, the main control section 11 can calculate the vehicle speed based on the detection signal of the output rotation speed sensor Se3.

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

Brake operation amount sensor Se5 is a sensor for detecting the amount of operation by the driver of a brake pedal provided in the vehicle in which vehicle drive system 100 is mounted. The main control unit 11 calculates the amount of operation of the brake pedal by the driver based on the detection signal of the brake operation amount sensor Se5.

Shift position sensor Se6 is a sensor for detecting a selected position (shift position) of a shift lever operated by the driver of the vehicle in which vehicle drive system 100 is mounted. The main control section 11 calculates the shift position based on the detection signal of the shift position sensor Se6. The shift lever is configured to select a parking range (P range), a reverse travel range (R range), a neutral range (N range), a forward travel range (D range), and the like.

The main control unit 11 selects an operation mode, which will be described later, based on the information from the sensors Se1 to Se6. The main control unit 11 controls, via the engagement control unit 15, the state of engagement according to the operation mode in which each of the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3 is selected. , the operation mode of the vehicle drive system 100 is shifted to the selected operation mode. Furthermore, the main control unit 11 controls 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. By cooperatively controlling the operating states of the two, it is possible to drive the vehicle appropriately according to the selected operating mode.

As shown in FIG. 4, in the present embodiment, the vehicle drive system 100 has three operation modes: eTC mode, first EV mode, second EV mode, first parallel mode, second parallel mode, and charging mode. mode and.

FIG. 4 shows the states of the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3 (shift clutch Ct and shift brake Bt) in each operation mode of the present embodiment. In addition, in each column of "CL1", "CL2", "Ct", and "Bt" indicating the symbols of the respective engaging devices in FIG. "-" indicates that the target engaging device is in the released 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 rotary electric machine MG1 as a reaction force and transmits the torque to the first output member O1, thereby causing the vehicle to run. . The eTC mode is called an electric torque converter mode because the torque of the internal combustion engine EG can be amplified and transmitted to the first output member O1.

As shown in FIG. 4, in the eTC mode, the first engagement device CL1 is in a direct engagement state, the second engagement device CL2 is in a disengagement state, and the transmission mechanism T is in a state of transmitting power. Then, the torque of the internal combustion engine EG and the first rotating electric machine MG1 is transmitted to the first output member O1. In the present embodiment, the third engagement device CL3 is in the state of forming the first shift stage (low speed stage). In other words, the shift clutch Ct is released and the shift brake Bt is directly engaged. In this embodiment, the eTC mode corresponds to the "second mode".

In the eTC mode of the present embodiment, the distribution differential gear mechanism SP combines the torque of the first rotary electric machine MG1 and the torque of the internal combustion engine EG, and outputs torque greater than the torque of the internal combustion engine EG from the first carrier C1. Output. Then, the rotation of the second ring gear R2, which rotates integrally with the first carrier C1, is changed at a gear ratio corresponding to the first gear stage (low speed stage) in the transmission mechanism T, and is transferred to the first output member O1 side. transmitted. Therefore, the eTC mode is preferably selected when relatively large torque needs to be transmitted to the first wheel W1, when the rotation speed of the internal combustion engine EG is low, and the like.

The first parallel mode and the second parallel mode are modes in which the vehicle is driven by at least the torque of the internal combustion engine EG, out of the internal combustion engine EG and the first rotating electric machine MG1. In the first parallel mode and the second parallel mode, the first engagement device CL1 is in a direct engagement state, the second engagement device CL2 is in a direct engagement state, and the transmission mechanism T is in a state of transmitting power. At least the torque of the internal combustion engine EG is transmitted to the first output member O1. In the first parallel mode of the present embodiment, the third engagement device CL3 is set to the first gear stage (low speed stage). In other words, the shift clutch Ct is released and the shift brake Bt is directly engaged. In addition, in the second parallel mode of the present embodiment, the third engagement device CL3 is set to the second speed stage (high speed stage). That is, the shift clutch Ct is directly engaged, and the shift brake Bt is released. As described above, in the present embodiment, the "second mode" is the eTC mode, but the "second mode" can also be the first parallel mode.

In the first parallel mode and the second parallel mode, the internal combustion engine EG is connected to the distribution differential gear mechanism SP by bringing the first engagement device CL1 into the direct engagement state. By bringing the second engagement device CL2 into the direct engagement state, the three rotary elements E1 to E3 of the distributing differential gear mechanism SP are brought into a state of integral rotation. As a result, the rotation input to the distribution differential gear mechanism SP from the internal combustion engine EG side and the first rotating electric machine MG1 side is transmitted to the transmission mechanism T as it is. In the first parallel mode, the rotation input to the transmission mechanism T is the gear ratio of the first gear stage (low speed stage), and in the second parallel mode, the gear ratio of the gear ratio of the first gear stage (low speed stage) according to the engagement state of the third engagement device CL3. The gear is shifted at the gear ratio of the second gear (high gear) and transmitted to the side of the first output member O1.

The first EV mode and the second EV mode are modes in which the vehicle is driven by the torque of only the first rotating electrical machine MG1 of the internal combustion engine EG and the first rotating electrical machine MG1. In the first EV mode and the second EV mode, the first engagement device CL1 is in the released state, the second engagement device CL2 is in the direct engagement state, and the transmission mechanism T is in the state of transmitting power. Then, the internal combustion engine EG is brought into a stopped state in which it does not output torque, and the torque of the first rotary electric machine MG1 is transmitted to the first output member O1. In the first EV mode of the present embodiment, the third engagement device CL3 is set to the first shift stage (low speed stage). In other words, the shift clutch Ct is released and the shift brake Bt is directly engaged. Further, in the second EV mode of the present embodiment, the third engagement device CL3 is set to the second speed stage (high speed stage). That is, the shift clutch Ct is directly engaged, and the shift brake Bt is released. In this embodiment, the first EV mode corresponds to the "first mode".

In the first EV mode and the second EV mode, the internal combustion engine EG is separated from the distribution differential gear mechanism SP by disengaging the first engagement device CL1, and the internal combustion engine EG and the first output member O1 are separated. Power transmission between is interrupted. By bringing the second engagement device CL2 into the direct engagement state, the three rotary elements E1 to E3 of the distributing differential gear mechanism SP rotate integrally with each other. As a result, the rotation input from the first rotary electric machine MG1 side to the distribution differential gear mechanism SP is transmitted to the transmission mechanism T as it is. In the first EV mode, the rotation transmitted to the transmission mechanism T is shifted to the gear ratio of the first shift stage (low speed stage) in accordance with the engagement state of the third engagement device CL3, and to the second gear shift in the second EV mode. The speed is changed at the gear ratio of the stage (high speed stage) and transmitted to the first output member O1 side.

The charge mode is a mode in which the power storage device BT is charged by causing the first rotary electric machine MG1 to generate power using the torque of the internal combustion engine EG. In the charging mode, the first engagement device CL1 is in a direct engagement state, the second engagement device CL2 is in a direct engagement state, and the transmission mechanism T is in a state in which power is not transmitted. Then, the internal combustion engine EG outputs torque, and the first rotary electric machine MG1 is controlled to output torque in a direction opposite to the rotation direction of the first rotor RT1 rotated by the torque of the internal combustion engine EG, thereby generating power. . In this embodiment, the third engagement device CL3 is in a released state (here, in a neutral state). That is, both the shift clutch Ct and the shift brake Bt are released. In the charge mode, the vehicle may be stopped, or the power generated by the first rotary electric machine MG1 may be used to drive the second rotary electric machine MG2, thereby transmitting the torque of the second rotary electric machine MG2 to the second wheels W2. By doing so, the vehicle may be driven. A mode in which the vehicle is driven by the torque of the second rotary electric machine MG2 while being in the charging mode is called a so-called series hybrid mode.

The control device 10 can execute the first transition control when transitioning from the first mode (here, the first EV mode) to the second mode (here, the eTC mode). The first transition control includes first control, second control, and third control. The control device 10 executes the first control, the second control, and the third control in the described order.

In the first control, the control device 10 changes the second engagement device CL2 from the direct engagement state to the slip engagement state while maintaining the state where the transmission mechanism T transmits power. In this embodiment, the engagement control unit 15 shifts the second engagement device CL2 from the direct engagement state to the slip engagement state while maintaining the disengaged state of the shift clutch Ct and the direct engagement state of the shift brake Bt. change to As a result, the three rotary elements E1 to E3 of the distributing differential gear mechanism SP become relatively rotatable.

In the second control, the control device 10 (here, the engagement control section 15) changes the first engagement device CL1 from the disengaged state to the slip engaged state.

In the third control, while maintaining the second engagement device CL2 in the slip engagement state, the control device 10 controls the distribution differential gear mechanism SP through the first engagement device CL1 in the slip engagement state. The internal combustion engine EG is started by the torque transmitted to the internal combustion engine EG. In the third control of the present embodiment, while the engagement control unit 15 maintains the second engagement device CL2 in the slip engagement state, the torque of the first rotary electric machine MG1 is reduced to the slip engagement state of the first engagement device CL1. The first rotating electrical machine control unit 13 controls the first rotating electrical machine MG1 so that the power is transmitted to the internal combustion engine EG via the . Accordingly, the input rotation speed Ni, which is the rotation speed of the input member I drivingly connected to the internal combustion engine EG, increases. After the input rotation speed Ni reaches the startable rotation speed Nf, which is the rotation speed necessary for starting the internal combustion engine EG, the main control unit 11 starts the internal combustion engine EG. In addition to the torque of the first rotary electric machine MG1, the "torque transmitted from the differential gear mechanism SP for distribution to the internal combustion engine EG via the first engagement device CL1 in the slip-engaged state" It may include torque transmitted from the side of one output member O1.

As described above, the vehicle drive system 100
an input member I drivingly connected to the internal combustion engine EG;
a first output member O1 drivingly connected to the first wheel W1;
a first rotating electric machine MG1 having a first rotor RT1;
A first rotating element E1, a second rotating element E2, and a third rotating element E3 are provided, the first rotating element E1 is drivingly connected to the input member I, and the third rotating element E3 is drivingly connected to the first rotor RT1. a distribution differential gear mechanism SP;
a first engagement device CL1 for connecting and disconnecting power transmission between the input member I and the first rotating element E1;
a second engaging device CL2 for connecting and disconnecting power transmission between two selected from three rotating elements of the first rotating element E1, the second rotating element E2, and the third rotating element E3;
A transmission for transmitting power between at least the second rotating element E2 and the first output member O1, which includes a third engaging device CL3 for connecting and disconnecting power transmission between the second rotating element E2 and the first output member O1. a mechanism T;
A vehicle drive device comprising: a control device 10 that controls an internal combustion engine EG, a first rotating electrical machine MG1, a first engagement device CL1, a second engagement device CL2, and a third engagement device CL3,
Each of the first engagement device CL1, the second engagement device CL2, and the third engagement device CL3 is a friction engagement device,
A first mode and a second mode are provided as operation modes,
A direct engagement state is defined as a state in which a pair of engagement elements of the friction engagement device are engaged without differential rotation, and a slip engagement state is defined as a state in which the pair of engagement elements are engaged with differential rotation. and a state in which the pair of engaging elements are not engaged is defined as a released state,
In the first mode, the first engagement device CL1 is in a disengaged state, the second engagement device CL2 is in a direct engagement state, the transmission mechanism T is in a state in which power is transmitted, and the internal combustion engine EG is in a stop state in which no torque is output. and the torque of the first rotating electric machine MG1 is transmitted to the first output member O1,
In the second mode, the first engagement device CL1 is in a direct engagement state, the second engagement device CL2 is in a released state or a direct engagement state, and the transmission mechanism T is in a state of transmitting power. Torque of the rotary electric machine MG1 is transmitted to the first output member O1,
The control device 10 can execute the first transition control when transitioning from the first mode to the second mode,
The first transition control is
a first control for changing the second engagement device CL2 from the direct engagement state to the slip engagement state while maintaining the power transmission state of the transmission mechanism T;
After the first control, a second control for changing the first engagement device CL1 from the disengaged state to the slip engaged state;
After the second control, while maintaining the second engagement device CL2 in the slip-engagement state, from the distribution differential gear mechanism SP side to the internal combustion engine EG via the first engagement device CL1 in the slip-engagement state. and a third control for starting the internal combustion engine EG by the transmitted torque.

According to this configuration, by changing the second engagement device CL2 from the direct engagement state to the slip engagement state in the first control, the rotational speed of the first rotary element E1 drivingly connected to the input member I is increased to It is lower than the rotational speeds of the second rotating element E2 and the third rotating element E3. As a result, compared to the case where the control for changing the third engagement device CL3 from the direct engagement state to the slip engagement state is executed while maintaining the second engagement device CL2 in the direct engagement state, the internal combustion engine EG The differential rotation between the pair of engaging elements of the first engaging device CL1, which is in the slip engaging state for starting the engine, can be kept small. As a result, the amount of heat generated by the first engagement device CL1 can be kept small. In addition, it is possible to shorten the time required for the rotation speed of the internal combustion engine EG to reach the rotation speed at which the first engagement device CL1 can be directly engaged.
Further, according to this configuration, by changing the second engagement device CL2 from the direct engagement state to the slip engagement state in the first control, after the start of the internal combustion engine EG is completed in the third control, the distributing The torque of the internal combustion engine EG transmitted to the differential gear mechanism SP for distribution and the torque of the first rotating electrical machine MG1 are combined in a state where the three rotating elements E1 to E3 of the differential gear mechanism SP have differential rotations. can be transmitted to the first output member O1. As a result, the torque can be transmitted to the first output member O1 immediately after the start of the internal combustion engine EG is completed.
Further, according to this configuration, the internal combustion engine EG is started while the second engagement device CL2 is maintained in the slip engagement state in the third control. It is possible to avoid transmitting to one output member O1.

In the present embodiment, the control device 10 selects the first transition control and the second transition control when shifting from the first mode (here, the first EV mode) to the second mode (here, the eTC mode). practically feasible. The second transition control includes fourth control, fifth control, and sixth control. The control device 10 executes the fourth control, fifth control, and sixth control in the described order.

In the fourth control, the control device 10 changes the third engagement device CL3 from the direct engagement state to the slip engagement state. In the fourth control of the present embodiment, the engagement control unit 15 changes the shift brake Bt from the direct engagement state to the slip engagement state while maintaining the shift clutch Ct in the released state.

In the fifth control, the control device 10 (here, the engagement control section 15) changes the first engagement device CL1 from the disengaged state to the slip engaged state.

In the sixth control, while maintaining the third engagement device CL3 in the slip engagement state, the control device 10 controls the distribution differential gear mechanism SP through the first engagement device CL1 in the slip engagement state. The internal combustion engine EG is started by the torque transmitted to the internal combustion engine EG. In the sixth control of the present embodiment, while the engagement control unit 15 maintains the disengaged state of the shift clutch Ct and the slip engaged state of the shift brake Bt, the torque of the first rotary electric machine MG1 is kept in the slip engaged state. The first rotating electrical machine control unit 13 controls the first rotating electrical machine MG1 so that the power is transmitted to the internal combustion engine EG via the first engagement device CL1. Accordingly, the input rotation speed Ni, which is the rotation speed of the input member I drivingly connected to the internal combustion engine EG, increases. After the input rotation speed Ni reaches the startable rotation speed Nf, which is the rotation speed necessary for starting the internal combustion engine EG, the main control unit 11 starts the internal combustion engine EG.

Thus, in the present embodiment, the control device 10 can selectively execute the first transition control and the second transition control when shifting from the first mode to the second mode.
The second transition control is
fourth control for changing the third engagement device CL3 from the direct engagement state to the slip engagement state;
After the fourth control, a fifth control for changing the first engagement device CL1 from the disengaged state to the slip engaged state;
After the fifth control, while maintaining the third engagement device CL3 in the slip engagement state, the internal combustion engine EG from the distribution differential gear mechanism SP side through the first engagement device CL1 in the slip engagement state. and a sixth control for starting the internal combustion engine EG by the transmitted torque.

According to this configuration, in the second transition control, the internal combustion engine EG is started while the third engagement device CL3 is maintained in the slip engagement state in the sixth control. It is possible to avoid transmission of rotation change to the first output member O1.
Further, according to this configuration, in the second transition control, by changing the third engagement device CL3 from the direct engagement state to the slip engagement state in the fourth control, the rotation speed of the input member I is reduced to the third transition control. It is higher than the rotation speed of the input member I corresponding to the rotation speed of the first output member O1 when the engagement device CL3 is in the direct engagement state. As a result, the internal combustion engine EG can be appropriately started even when the rotation speed of the first output member O1 is low, that is, when the vehicle travels at a low speed.

In this embodiment, the control device 10 executes the first transition control when the assumed input rotation speed Nis is equal to or higher than the startable rotation speed Nf. On the other hand, when the assumed input rotational speed Nis is less than the startable rotational speed Nf, the control device 10 executes the second transition control. Here, the assumed input rotation speed Nis is the input rotation speed Ni ( is the rotational speed of the input member I).

Thus, in the present embodiment, in a configuration in which the control device 10 can selectively execute the first transition control and the second transition control,
The control device 10
The assumed input rotation speed Nis, which is the input rotation speed Ni corresponding to the output rotation speed when it is assumed that the first transition control is executed, becomes equal to or higher than the startable rotation speed Nf, which is the rotation speed necessary for starting the internal combustion engine EG. In the case, execute the first transition control,
The assumed input rotation speed Nis, which is the input rotation speed Ni corresponding to the output rotation speed when it is assumed that the first transition control is executed, becomes less than the startable rotation speed Nf, which is the rotation speed necessary for starting the internal combustion engine EG. In that case, the second transition control is executed.

According to this configuration, the internal combustion engine EG can be appropriately started according to the traveling speed of the vehicle.

In addition, in the present embodiment, the control device 10, during execution of the first transition control, distributes the torque according to the accelerator opening of the vehicle from the first rotary electric machine MG1 side to the first rotary electric machine MG1 via the distribution differential gear mechanism SP. The engagement pressure of the second engagement device CL2 is controlled so as to be transmitted to the output member O1 side.

According to this configuration, even during the execution of the first transition control, the torque fluctuation accompanying the start of the internal combustion engine EG is prevented from being transmitted to the first output member O1, and the torque required for the first output member O1 is prevented. torque can be transmitted.

Further, in the present embodiment, the control device 10 controls the torque transmitted to the first output member O1 according to the accelerator opening of the vehicle and the first engagement device in the slip engagement state during execution of the first transition control. The first rotating electric machine MG1 is controlled so that the first rotating electric machine MG1 outputs a torque corresponding to both the torque transmitted to the internal combustion engine EG via CL1.

According to this configuration, it is possible to properly start the internal combustion engine EG while transmitting the required torque to the first output member O1.

Control processing of the control device 10 when the operation mode of the vehicle drive device 100 is shifted from the first mode to the second mode will be described below with reference to FIGS. 5 to 7. FIG.

FIG. 5 shows an example of control processing of the control device 10 when the operation mode of the vehicle drive device 100 is shifted from the first mode (here, the first EV mode) to the second mode (here, the eTC mode). It is a flow chart. In this example, when the control process of the control device 10 is started, the first engagement device CL1 is in the disengaged state, and the second engagement device CL2 and the third engagement device CL3 (here, shift brakes) are in the disengaged state. Bt) are in the direct engagement state.

As shown in FIG. 5, first, the control device 10 determines whether or not the current operation mode of the vehicle drive device 100 is the first mode (here, the first EV mode) (step #1). In this example, the main control unit 11 determines via the internal combustion engine control unit 12 whether the internal combustion engine EG is in a stopped state, and via the first rotating electrical machine control unit 13 determines whether the first rotating electrical machine MG1 is in a power running state. By determining whether the first engagement device CL1 is in the released state and the second engagement device CL2 and the third engagement device CL3 are in the direct engagement state via the engagement control unit 15, Make the decision above.

When the control device 10 determines that the current operation mode of the vehicle drive device 100 is not the first mode (here, the first EV mode) (step #1: No), the control ends. On the other hand, when the control device 10 determines that the current operation mode of the vehicle drive device 100 is the first mode (here, the first EV mode) (step #1: Yes), the second mode (here, eTC mode) is determined (step #2). In this example, the main control unit 11 calculates the charge amount of the power storage device BT based on the detection signal of the SOC sensor Se1, and the input rotation speed Ni (input member I) calculated based on the detection signal of the input rotation speed sensor Se2. rotational speed), output rotational speed (rotational speed of the first output member O1) calculated based on the detection signal of the output rotational speed sensor Se3, accelerator opening calculated based on the detection signal of the accelerator operation amount sensor Se4, brake operation The above determination is made based on the operation amount of the brake pedal calculated based on the detection signal of the amount sensor Se5 and the shift position calculated based on the detection signal of the shift position sensor Se6.

If there is no request to shift to the second mode (here, the eTC mode) (step #2: No), the control device 10 ends the control. When there is a request to shift to the second mode (here, the eTC mode) (step #2: Yes), the control device 10 determines whether or not the assumed input rotation speed Nis is equal to or higher than the startable rotation speed Nf. (step #3). In this example, the main control unit 11 calculates the input rotation speed Ni (rotation speed of the input member I) based on the detection signal of the input rotation speed sensor Se2 and the detection signal of the output rotation speed sensor Se3. Based on the output rotation speed (the rotation speed of the first output member O1), etc., it is assumed that the input rotation speed Ni corresponds to the output rotation speed when it is assumed that the first transition control is executed in the current running state of the vehicle. The above determination is made by calculating the input rotation speed Nis and comparing it with the startable rotation speed Nf.

When the control device 10 determines that the assumed input rotation speed Nis is equal to or higher than the startable rotation speed Nf (step #3: Yes), the control device 10 executes the first transition control (step #10). On the other hand, when the control device 10 determines that the assumed input rotational speed Nis is less than the startable rotational speed Nf (step #3: No), it executes the second transition control (step #20).

FIG. 6 is a flowchart showing an example of first transition control. As shown in FIG. 6, in the first transition control, the control device 10 first changes the second engagement device CL2 from the direct engagement state to the slip engagement state (step #11). This step #11 corresponds to "first control" for changing the second engagement device CL2 from the direct engagement state to the slip engagement state while maintaining the state where the transmission mechanism T transmits power.

Next, the control device 10 changes the first engagement device CL1 from the disengaged state to the slip engaged state (step #12). This step #12 corresponds to "second control" for changing the first engagement device CL1 from the disengaged state to the slip engaged state after the first control. Note that step #12 can be started immediately after the differential rotation of the pair of engaging elements of the second engaging device CL2 begins to occur in step #11.

Subsequently, the control device 10 controls the first rotary electric machine MG1 so as to transmit torque from the first rotary electric machine MG1 to the internal combustion engine EG via the first engagement device CL1 in the slip engagement state (step # 13).

Then, the control device 10 determines whether or not the input rotation speed Ni is equal to or higher than the startable rotation speed Nf (step #14). While determining that the input rotation speed Ni is less than the startable rotation speed Nf (step #14: No), the control device 10 continues to execute step #13. When the control device 10 determines that the input rotation speed Ni is equal to or higher than the startable rotation speed Nf (step #14: Yes), it starts the internal combustion engine EG (step #15). Specifically, the internal combustion engine EG is started by, for example, starting fuel supply to the internal combustion engine EG and ignition.

In steps #13 to #15, after the second control, while maintaining the second engagement device CL2 in the slip engagement state, the distribution control is performed via the first engagement device CL1 in the slip engagement state. This corresponds to "third control" in which the internal combustion engine EG is started by torque transmitted from the differential gear mechanism SP to the internal combustion engine EG.

After starting the internal combustion engine EG, the control device 10 changes the first engagement device CL1 from the slip engagement state to the direct engagement state, and changes the second engagement device CL2 from the slip engagement state to the release state ( step #16). As a result, the operation mode of the vehicle drive system 100 shifts to the eTC mode as the second mode. If the second mode is not the eTC mode but the first parallel mode, the control device 10 changes the second engagement device CL2 from the slip engagement state to the direct engagement state.

FIG. 7 is a flow chart showing an example of the second transition control. As shown in FIG. 7, in the second transition control, first, the control device 10 changes the third engagement device CL3 (here, the shift brake Bt) from the direct engagement state to the slip engagement state (step #21). This step #21 corresponds to "fourth control" for changing the third engagement device CL3 (here, the shift brake Bt) from the direct engagement state to the slip engagement state.

Next, the control device 10 changes the first engagement device CL1 from the disengaged state to the slip engaged state (step #22). This step #22 corresponds to "fifth control" for changing the first engagement device CL1 from the disengaged state to the slip engaged state after the fourth control. Note that step #22 can be started immediately after differential rotation of the pair of engaging elements of the third engaging device CL3 begins in step #21.

Subsequently, the control device 10 controls the first rotary electric machine MG1 so as to transmit torque from the first rotary electric machine MG1 to the internal combustion engine EG via the first engagement device CL1 in the slip engagement state (step # 23).

Then, the control device 10 determines whether or not the input rotation speed Ni is equal to or higher than the startable rotation speed Nf (step #24). While determining that the input rotation speed Ni is less than the startable rotation speed Nf (step #24: No), the control device 10 continues to execute step #23. When the control device 10 determines that the input rotation speed Ni is equal to or higher than the startable rotation speed Nf (step #24: Yes), it starts the internal combustion engine EG (step #25).

In steps #23 to #25 described above, after the fifth control, the third engagement device CL3 (here, the shift brake Bt) is maintained in the slip engagement state while the first clutch in the slip engagement state is maintained. This corresponds to "sixth control" in which the internal combustion engine EG is started by torque transmitted from the distributing differential gear mechanism SP to the internal combustion engine EG via the engagement device CL1.

After starting the internal combustion engine EG, the control device 10 changes the first engagement device CL1 from the slip engagement state to the direct engagement state, changes the second engagement device CL2 from the direct engagement state to the release state, The third engagement device CL3 (here, the shift brake Bt) is changed from the slip engagement state to the direct engagement state (step #26). As a result, the operation mode of the vehicle drive system 100 shifts to the eTC mode as the second mode. If the second mode is the first parallel mode instead of the eTC mode, the control device 10 maintains the second engagement device CL2 in the direct engagement state.

FIG. 8 is a time chart showing an example of the first transition control. In the "rotation speed" chart of FIG. 8, "N1" represents the first rotation speed, which is the rotation speed of the first rotation element E1 (here, the first ring gear R1), and "N2" represents the second rotation element E2. (Here, the first carrier C1) represents the second rotation speed, and "N3" represents the third rotation speed, which is the rotation speed of the third rotation element E3 (here, the first sun gear S1). ing. "Ni" represents the input rotational speed converted into the rotational speed of the first rotational element E1. Further, "S" is the second rotational element E2 (here, the first carrier) that is determined according to the output rotational speed when the third engagement device CL3 (here, the shift brake Bt) is directly engaged. C1) represents the rotational speed (synchronization line). Further, in the "torque" chart of FIG. 8, "Tm" represents the first output torque that is the output torque of the first rotary electric machine MG1, and "Tmd" represents the first output torque that drives the first wheel W1. It represents the first driving torque, which is the torque that acts as a force. Further, "Te" represents the second output torque that is the output torque of the internal combustion engine EG, and "Ted" represents the second drive torque that is the torque that drives the first wheel W1 among the second output torques. ing. Note that the reference numerals in the time chart of FIG. 8 are the same in FIG. 9 as well.

As shown in FIG. 8, in this example, when the control process of the control device 10 is started, the operation mode of the vehicle drive device 100 is the first EV mode as the first mode. In this state, the control device 10 first controls the target engagement pressure (engagement pressure command) of the second engagement device CL2 so that the second engagement device CL2 changes from the direct engagement state to the slip engagement state. is gradually lowered from time t11 to time t12. As the second engagement device CL2 enters the slip engagement state, the three rotary elements E1 to E3 of the distribution differential gear mechanism SP become relatively rotatable. Therefore, in this example, from time t11 to time t12, the first rotation speed N1 gradually decreases relative to the second rotation speed N2, and the third rotation speed N3 gradually increases relative to the second rotation speed N2.

Next, the control device 10 increases the target engagement pressure (engagement pressure command) of the first engagement device CL1 at time t12 so that the first engagement device CL1 changes from the released state to the slip engagement state. Let Then, the control device 10 controls the first rotary electric machine MG1 so as to increase the first output torque Tm, so that the input member is output from the first rotary electric machine MG1 via the first engagement device CL1 in the slip engagement state. The torque transmitted to I increases the input rotation speed Ni so as to approach the first rotation speed N1 from time t12 to time t13. After the input rotation speed Ni reaches the startable rotation speed Nf, the control device 10 starts the internal combustion engine EG.

Subsequently, the control device 10 sets the target engagement pressure (engagement pressure command) of the first engagement device CL1 at time t13 so that the first engagement device CL1 changes from the slip engagement state to the direct engagement state. gradually increase from As the first engagement device CL1 enters the direct engagement state, the input member I and the output shaft ES of the internal combustion engine EG rotate integrally. As a result, the second drive torque Ted increases to approach the second output torque Te. At this time, the torque of the internal combustion engine EG transmitted to the differential gear mechanism SP for distribution and the torque of the first rotary electric machine MG1 are transmitted to the differential gear mechanism SP for distribution while the three rotating elements E1 to E3 of the differential gear mechanism SP for distribution have differential rotations. are added together and transmitted to the first output member O1.

Thereafter, the control device 10 gradually lowers the target engagement pressure (engagement pressure command) of the second engagement device CL2 from time t14 so that the second engagement device CL2 changes from the slip engagement state to the release state. Let As the second engagement device CL2 is released, the operation mode of the vehicle drive system 100 shifts to the eTC mode as the second mode.

FIG. 9 is a time chart showing an example of the second transition control. As shown in FIG. 9, in this example, the operation mode of the vehicle drive device 100 is the first EV mode as the first mode when the control process of the control device 10 is started. In this state, the control device 10 first sets the target value of the third engagement device CL3 so that the third engagement device CL3 (here, the shift brake Bt) changes from the direct engagement state to the slip engagement state. The engagement pressure (engagement pressure command) is gradually lowered from time t21 to time t22. As the third engagement device CL3 enters the slip engagement state, the first rotational speed N1, the second rotational speed N2, and the third rotational speed N3 are reduced with respect to the synchronization line S from time t21 to time t22. Gradually increase.

Next, the control device 10 increases the target engagement pressure (engagement pressure command) of the first engagement device CL1 at time t22 so that the first engagement device CL1 changes from the released state to the slip engagement state. Let Then, the control device 10 controls the first rotary electric machine MG1 so as to increase the first output torque Tm, so that the input member is output from the first rotary electric machine MG1 via the first engagement device CL1 in the slip engagement state. The torque transmitted to I increases the input rotation speed Ni so as to approach the first rotation speed N1 from time t22 to time t23. After the input rotation speed Ni reaches the startable rotation speed Nf, the control device 10 starts the internal combustion engine EG.

Subsequently, the control device 10 sets the target engagement pressure (engagement pressure command) of the first engagement device CL1 at time t23 so that the first engagement device CL1 changes from the slip engagement state to the direct engagement state. gradually increase from As the first engagement device CL1 enters the direct engagement state, the input member I and the output shaft ES of the internal combustion engine EG rotate integrally. As a result, the second drive torque Ted increases to approach the second output torque Te.

After that, the control device 10 controls the target engagement pressure ( engagement pressure command) is gradually increased from time t24 to time t25. Accordingly, the first rotation speed N1, the second rotation speed N2, and the third rotation speed N3 gradually decrease so as to approach the synchronization line S from time t24 to time t25.

Then, the control device 10 gradually lowers the target engagement pressure (engagement pressure command) of the second engagement device CL2 from time t26 so that the second engagement device CL2 changes from the directly engaged state to the released state. Let With the disengagement of the second engagement device CL2, the three rotary elements E1 to E3 of the distributing differential gear mechanism SP become relatively rotatable. Thus, the operation mode of the vehicle drive system 100 shifts to the eTC mode as the second mode.

As shown in FIGS. 8 and 9, the differential rotation of the pair of engagement elements of the first engagement device CL1 in the slip engagement state in the first transition control (input rotation speed Ni at time t12 in FIG. 8 and time t13 ) is the differential rotation of the pair of engagement elements of the first engagement device CL1 in the slip engagement state in the second transition control (input rotation speed Ni at time t22 in FIG. 9 and the input rotation speed Ni at time t23). If the synchronization line S in the first transition control and the synchronization line S in the second transition control are assumed to be the same, the magnitude relationship of the differential rotation is as described above.

Further, the time from the start of the first transition control until the second drive torque Ted starts to rise (see the period from time t11 to time t13 in FIG. 8) is It is shorter than the time until it starts to rise (see the period from time t21 to time t23 in FIG. 9). Note that the increase rate per unit time of the input rotation speed Ni from time t12 to time t13 in the first transition control and the increase rate per unit time of the input rotation speed Ni from time t22 to time t23 in the second transition control. are the same, the length of time is such a relation.

[Other embodiments]
(1) In the above embodiment, the configuration in which the vehicle drive system 100 includes the first drive unit DU1 and the second drive unit DU2 has been described as an example. However, the configuration is not limited to such a configuration, and a configuration in which the vehicle drive device 100 includes the first drive unit DU1 and does not include the second drive unit DU2 is also possible. In this case, as shown in FIG. 10, the first drive unit DU1 may include the second rotating electric machine MG2. In the example shown in FIG. 10, the second rotor gear RG2 rotating integrally with the second rotor RT2 of the second rotary electric machine MG2 is the second idler gear in the circumferential direction of the first differential input gear 4 as the first output member O1. It meshes with the first differential input gear 4 at a position different from 32 . In this configuration, the second rotary electric machine MG2 is positioned closer to the first output member than the third engagement device CL3 in the power transmission path between the second rotary element E2 of the distributing differential gear mechanism SP and the first output member O1. On the O1 side it is drivingly connected to the first output member O1. Note that the vehicle drive device 100 may be configured without the second rotating electric machine MG2.

(2) In the above embodiment, the second mode as the operation mode of the vehicle drive system 100 is the eTC mode or the first parallel mode. However, the configuration is not limited to such a configuration. For example, the second mode may be a so-called split hybrid mode. Here, the split hybrid mode means that the torque of the internal combustion engine EG is distributed between the first rotary electric machine MG1 side and the first output member O1 side (transmission mechanism T side), and the torque of the first rotary electric machine MG1 is In this mode, as a reaction force, torque attenuated with respect to the torque of the internal combustion engine EG is transmitted to the first output member O1. In this case, the order of rotation speed of each rotary element of the differential gear mechanism SP for distribution should be the order of the second rotary element E2, the first rotary element E1, and the third rotary element E3. For example, when the distributing differential gear mechanism SP is configured by a single-pinion planetary gear mechanism, the sun gear is drivingly connected to the first rotor RT1 as the third rotating element E3, and the carrier is the first rotating element E1 as the input member I. , and the ring gear can be used as the output element of the distribution differential gear mechanism SP as the second rotating element E2. In this mode, the first rotating electrical machine MG1 rotates forward and outputs negative torque to generate power, and the differential gear mechanism SP for distribution uses the torque of the first rotating electrical machine MG1 as a reaction force to generate the torque of the internal combustion engine EG. is output from the second rotating element E2. The rotation of the second rotating element E2 is transmitted via the transmission mechanism T to the first output member O1.

(3) In the above embodiment, the distributing differential gear mechanism SP is a single pinion type planetary gear mechanism, the first rotating element E1 is the first ring gear R1, and the second rotating element E2 is the first carrier C1. , and the configuration in which the third rotating element E3 is the first sun gear S1 has been described as an example. However, without being limited to such a configuration, the first rotating element E1 is the first sun gear S1, the second rotating element E2 is the first carrier C1, and the third rotating element E3 is the first ring gear R1. A certain configuration may be used. Alternatively, the distribution differential gear mechanism SP may be a double pinion type planetary gear mechanism. In this case, the first rotating element E1 is preferably the sun gear or the carrier, the second rotating element E2 is the ring gear, and the third rotating element E3 is the other of the sun gear or the carrier.

(4) In the above embodiment, the configuration in which the transmission mechanism T is a transmission capable of forming either one of the first gear stage (low speed stage) and the second gear stage (high speed stage) is taken as an example. explained. However, without being limited to such a configuration, the transmission mechanism T may be a transmission capable of forming any one of three or more gear stages. Alternatively, the transmission mechanism T is a fixed speed ratio transmission (reducer or speed increaser) that shifts the rotation transmitted from the second rotary element E2 of the distribution differential gear mechanism SP at a constant speed ratio. Also good.

(5) In the above embodiment, the configuration in which the transmission mechanism T is a planetary gear type transmission has been described as an example. However, without being limited to such a configuration, the transmission mechanism T may be configured as a parallel shaft gear type transmission.

(6) In the above embodiment, the direct engagement state of the third engagement device CL3 corresponds to the disengaged state of the shift clutch Ct and the direct engagement state of the shift brake Bt. The slip engagement state of CL3 corresponds to the disengaged state of the shift clutch Ct and the slip engaged state of the shift brake Bt, and the disengaged state of the third engagement device CL3 corresponds to the shift clutch Ct and the shift brake. Although the configuration in which both Bt correspond to the released state has been described as an example, it is not limited to such a configuration. For example, the third engagement device CL3 may be composed of one frictional engagement device, and the engagement state of this frictional engagement device may correspond to the engagement state of the third engagement device CL3.

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

INDUSTRIAL APPLICABILITY The technology according to the present disclosure can be used in a vehicle drive device that performs control for starting an internal combustion engine by torque transmitted from a rotating electric machine to the internal combustion engine while keeping a friction engagement device in a slip engagement state.

100: vehicle driving device, 10: control device, I: input member, O1: first output member (output member), MG1: first rotating electric machine (rotating electric machine), RT1: first rotor (rotor), SP: Distributing differential gear mechanism (differential gear mechanism), E1: first rotary element, E2: second rotary element, E3: third rotary element, CL1: first engagement device, CL2: second engagement device, CL3: third engagement device, T: transmission mechanism, EG: internal combustion engine, W1: first wheel (wheel)

Claims (5)

an input member drivingly connected to an internal combustion engine;
an output member drivingly connected to the wheel;
a rotating electric machine having a rotor;
a differential gear mechanism comprising a first rotating element, a second rotating element, and a third rotating element, wherein the first rotating element is drivingly connected to the input member and the third rotating element is drivingly connected to the rotor; ,
a first engaging device for connecting and disconnecting power transmission between the input member and the first rotating element;
a second engaging device for connecting and disconnecting power transmission between two selected from three rotating elements of the first rotating element, the second rotating element, and the third rotating element;
a transmission mechanism that includes a third engagement device that connects and disconnects power transmission between the second rotating element and the output member, and that performs power transmission between at least the second rotating element and the output member;
A vehicle drive device comprising: a control device that controls the internal combustion engine, the rotating electric machine, the first engagement device, the second engagement device, and the third engagement device,
each of the first engagement device, the second engagement device, and the third engagement device is a frictional engagement device;
A first mode and a second mode are provided as operation modes,
A state in which the pair of engaging elements of the friction engagement device are engaged without differential rotation is referred to as a direct engagement state, and a state in which the pair of engaging elements are engaged with differential rotation is referred to as a slip engagement state. A engaged state is defined as a state in which the pair of engaging elements are not engaged is defined as a released state,
In the first mode, the first engagement device is in the released state, the second engagement device is in the direct engagement state, and the transmission mechanism is in a state of transmitting power, and the internal combustion engine does not output torque. a stopped state, the torque of the rotating electrical machine is transmitted to the output member,
In the second mode, the first engagement device is in the directly engaged state, the second engagement device is in the released state or the directly engaged state, the transmission mechanism is in a state of transmitting power, and the internal combustion engine Torque of the engine and the rotating electric machine is transmitted to the output member,
The control device is capable of executing first transition control when transitioning from the first mode to the second mode,
The first transition control is
a first control for changing the second engagement device from the direct engagement state to the slip engagement state while maintaining the power transmission state of the transmission mechanism;
a second control for changing the first engagement device from the released state to the slip engagement state after the first control;
After the second control, while maintaining the second engagement device in the slip engagement state, the internal combustion engine is operated from the differential gear mechanism side via the first engagement device in the slip engagement state. and a third control for starting the internal combustion engine by the torque transmitted to the vehicle. The control device is capable of selectively executing the first transition control and the second transition control when shifting from the first mode to the second mode,
The second transition control is
fourth control for changing the third engagement device from the direct engagement state to the slip engagement state;
a fifth control for changing the first engagement device from the released state to the slip engagement state after the fourth control;
After the fifth control, while maintaining the third engagement device in the slip engagement state, the internal combustion engine is operated from the differential gear mechanism side via the first engagement device in the slip engagement state. 2. The vehicle drive system according to claim 1, further comprising a sixth control for starting said internal combustion engine by torque transmitted to said internal combustion engine. Let the rotation speed of the input member be the input rotation speed, and let the rotation speed of the output member be the output rotation speed,
The control device is
When the input rotation speed corresponding to the output rotation speed when the first transition control is executed is equal to or higher than the rotation speed necessary for starting the internal combustion engine, the first transition control is executed. ,
If the input rotation speed corresponding to the output rotation speed when the first transition control is executed is less than the rotation speed necessary for starting the internal combustion engine, the second transition control is executed. 3. The vehicle drive system according to claim 2. During execution of the first transition control, the control device transmits torque corresponding to the accelerator opening of the vehicle from the rotating electrical machine side to the output member side via the differential gear mechanism. 4. The vehicle drive system according to any one of claims 1 to 3, wherein the engagement pressure of said second engagement device is controlled. During execution of the first transition control, the control device controls torque transmitted to the output member in accordance with the accelerator opening of the vehicle and the internal combustion engine via the first engagement device in the slip engagement state. 5. The vehicle driving device according to any one of claims 1 to 4, wherein said rotating electrical machine is controlled such that said rotating electrical machine outputs a torque corresponding to both of a torque transmitted to said rotating electrical machine and a torque corresponding to both of said rotating electrical machine.

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