JP7764786B2 - Hybrid vehicle control device - Google Patents

Description

The present invention relates to a control device for a hybrid vehicle.

Hybrid vehicles equipped with dual-clutch transmissions having two clutches have been known for some time (see Patent Document 1).

This dual-clutch transmission comprises an input system including a first input shaft connected to the internal combustion engine via a first clutch and a second input shaft connected to the internal combustion engine via a second clutch; an output system connected to the drive wheels so as to transmit driving force; and multiple gear trains, some of which are interposed between the first input shaft and the output system and the rest of which are interposed between the second input shaft and the output system, and which have different gear ratios.

The dual-clutch transmission also includes a first motor generator connected to the first input shaft so as to be able to transmit driving force, and a second motor generator connected to the second input shaft so as to be able to transmit driving force, and operates in two modes: an engine driving mode in which either the first clutch or the second clutch is switched into an engaged state to drive the drive wheels with the internal combustion engine, and a motor driving mode in which the internal combustion engine is stopped and the drive wheels are driven by either the first motor generator or the second motor generator.

Japanese Patent Application Laid-Open No. 2014-201126

However, conventional dual-clutch transmissions require two sets of clutches, a first clutch and a second clutch, which increases the size of the transmission and increases the manufacturing costs of the transmission.

The present invention was developed in response to the above-mentioned circumstances, and aims to provide a control device for a hybrid vehicle that can smoothly start an internal combustion engine without using multiple clutches, can reduce the size of the transmission, and can reduce the manufacturing costs of the transmission.

The present invention has a transmission that changes the speed of a driving force of an internal combustion engine and transmits it to drive wheels, and the transmission includes an input shaft to which the driving force of the internal combustion engine is transmitted, an odd-numbered stage intermediate shaft that is provided coaxially with the input shaft and rotatable relative to the input shaft, an even-numbered stage intermediate shaft that is positioned outside the input shaft and coaxially with the input shaft and opposed to the odd-numbered stage intermediate shaft in the axial direction of the input shaft and rotatable relative to the input shaft, and an even-numbered stage intermediate shaft that is parallel to the odd-numbered stage intermediate shaft and the even-numbered stage intermediate shaft. an odd-numbered stage rotating electric machine connected to the odd-numbered stage intermediate shaft so as to be able to transmit driving force; an even-numbered stage rotating electric machine connected to the even-numbered stage intermediate shaft so as to be able to transmit driving force; a plurality of odd-numbered stage gear pairs connecting the odd-numbered stage intermediate shaft and the output shaft so as to be able to transmit driving force, thereby constituting odd-numbered stage gears with different gear ratios; and a gear pair connecting the even-numbered stage intermediate shaft and the output shaft so as to be able to transmit driving force, thereby constituting even-numbered stage gears with different gear ratios. A control device for a hybrid vehicle having a plurality of even-numbered gear pairs, wherein the odd-numbered gear pairs have a plurality of odd-numbered intermediate shaft side gears provided to be rotatable integrally with the odd-numbered intermediate shaft, and a plurality of odd-numbered output shaft side gears provided to be rotatable relative to the output shaft and meshing with the plurality of odd-numbered intermediate shaft side gears, and the even-numbered gear pairs have a plurality of even-numbered intermediate shaft side gears provided to be rotatable integrally with the even-numbered intermediate shaft, and a plurality of odd-numbered output shaft side gears provided to be rotatable relative to the output shaft, and a plurality of even-numbered stage output shaft side gears meshing with the plurality of even-numbered stage intermediate shaft side gears, respectively, and the transmission includes a first switching member that is switchable between a neutral position, an odd-numbered stage position that connects the input shaft and the odd-numbered stage intermediate shaft, and an even-numbered stage position that connects the input shaft and the even-numbered stage intermediate shaft; and a second switching member that establishes odd-numbered stage gears by connecting any one of the plurality of odd-numbered stage output shaft side gears to the output shaft and rotating it integrally with the output shaft. a third switching member that establishes an even-numbered gear by connecting any one of the plurality of even-numbered gears to the output shaft and rotating integrally with the output shaft; and a control unit that switches a traveling mode of the vehicle between an EV mode in which the internal combustion engine is stopped and the vehicle is traveling using at least one of the odd-numbered gear rotating electric machine and the even-numbered gear rotating electric machine, and an HEV mode in which the vehicle is traveling using at least one of the odd-numbered gear rotating electric machine and the even-numbered gear rotating electric machine and the internal combustion engine, wherein when the traveling mode is shifted from the EV mode to the HEV mode, the control unit starts the internal combustion engine using one of the odd-numbered gear rotating electric machine and the even-numbered gear rotating electric machine, and controls the driving force of one of the odd-numbered gear rotating electric machine and the even-numbered gear rotating electric machine to control the driving force of the internal combustion engine and the driving force of the odd-numbered gear rotating electric machine and the even-numbered gear rotating electric machine until a gear to which driving force is transmitted from the internal combustion engine is established. The vehicle is driven by the other driving force , and when an odd-numbered gear is established during a transition from the EV mode to the HEV mode, the second switching member is controlled to be switched to a neutral position when the driving force of the odd-numbered gear rotating electric machine reaches a predetermined value, and then the driving force of the odd-numbered gear rotating electric machine is controlled so that the rotation speed of the odd-numbered gear intermediate shaft becomes a predetermined value, thereby engaging the first switching member with the odd-numbered gear intermediate shaft, thereby starting the internal combustion engine by the odd-numbered gear rotating electric machine. When an even-numbered gear is established during a transition from the EV mode to the HEV mode, the third switching member is controlled to be switched to a neutral position when the driving force of the even-numbered gear rotating electric machine reaches a predetermined value, and then the driving force of the even-numbered gear rotating electric machine is controlled so that the rotation speed of the even-numbered gear intermediate shaft becomes a predetermined value, thereby engaging the first switching member with the even-numbered gear intermediate shaft, thereby starting the internal combustion engine by the even-numbered gear rotating electric machine .

As described above, the present invention allows for smooth starting of the internal combustion engine without using multiple clutches, making it possible to reduce the size of the transmission and its manufacturing costs.

FIG. 1 is a diagram showing the configuration of a hybrid vehicle according to an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of a transmission for a hybrid vehicle according to one embodiment of the present invention. FIG. 3 is a diagram showing driving modes of a hybrid vehicle according to an embodiment of the present invention. FIG. 4 is a timing chart of the driving mode transition control executed by the control device for a hybrid vehicle according to one embodiment of the present invention. FIG. 5 is a timing chart of another driving mode transition control executed by the control device for a hybrid vehicle according to one embodiment of the present invention. FIG. 6 is a timing chart of another driving mode transition control executed by the control device for a hybrid vehicle according to one embodiment of the present invention.

A control device for a hybrid vehicle according to one embodiment of the present invention has a transmission that changes the speed of the driving force of an internal combustion engine and transmits it to the drive wheels. The transmission includes an input shaft to which the driving force of the internal combustion engine is transmitted, an odd-numbered intermediate shaft that is arranged coaxially with the input shaft and rotatable relative to the input shaft, an even-numbered intermediate shaft that is positioned outside the input shaft, coaxially with the input shaft, and opposed to the odd-numbered intermediate shaft in the axial direction of the input shaft, and rotatable relative to the input shaft, an output shaft that is arranged parallel to the odd-numbered intermediate shaft and the even-numbered intermediate shaft and transmits the driving force to the drive wheels, an odd-numbered rotating electric machine connected to the odd-numbered intermediate shaft so as to be able to transmit driving force, an even-numbered rotating electric machine connected to the even-numbered intermediate shaft so as to be able to transmit driving force, a plurality of odd-numbered gear pairs that connect the odd-numbered intermediate shaft to the output shaft so as to be able to transmit driving force and that constitute odd-numbered gear stages with different gear ratios, and a pair of odd-numbered intermediate shafts that connect the even-numbered intermediate shaft to the output shaft so as to be able to transmit driving force. A control device for a hybrid vehicle having a plurality of even-numbered gear pairs that constitute even-numbered gear stages with different gear ratios, and a control unit that switches the vehicle's driving mode between an EV mode in which the internal combustion engine is stopped and the vehicle is driven by at least one of the odd-numbered gear and the even-numbered gear rotating electric machine, and an HEV mode in which the vehicle is driven by at least one of the odd-numbered gear and the even-numbered gear rotating electric machine and the internal combustion engine. When switching the driving mode from EV mode to HEV mode, the control unit starts the internal combustion engine using either the odd-numbered gear and the even-numbered gear rotating electric machine, and controls the driving force of either the odd-numbered gear and the even-numbered gear rotating electric machine and the driving force of the internal combustion engine to drive the vehicle using the driving force of the other of the odd-numbered gear and the even-numbered gear rotating electric machine until a gear stage to which driving force is transmitted from the internal combustion engine is established.

As a result, the control device for a hybrid vehicle according to one embodiment of the present invention can smoothly start the internal combustion engine without using multiple clutches, allowing for a smaller transmission and reducing the manufacturing costs of the transmission.

The following describes a hybrid vehicle control device according to one embodiment of the present invention, using the drawings. Figures 1 to 6 show a hybrid vehicle control device according to one embodiment of the present invention.

First, the configuration will be described.
As shown in FIG. 1 , a hybrid vehicle 1 (hereinafter referred to as vehicle 1) includes an engine 2 as an internal combustion engine, a transmission 3, drive wheels 4L, 4R, an HCU (Hybrid Control Unit) 10 that comprehensively controls the vehicle 1, an ECU (Engine Control Unit) 11 that controls the engine 2, a TCU (Transmission Control Unit) 12 that controls the transmission 3, a BMS (Battery Management System) 13, an odd-stage inverter 14, an even-stage inverter 15, and a battery 16.

Engine 2 has multiple cylinders. In this embodiment, engine 2 is configured to perform a series of four strokes for each cylinder: an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke.

The transmission 3 changes the driving force (rotational speed) output from the engine 2 and transmits it to the left and right drive wheels 4L, 4R via the left and right drive shafts 31L, 31R, thereby driving the drive wheels 4L, 4R.

The transmission 3 includes a transmission mechanism 21, a differential device 22, an odd-numbered gear motor-generator 23, an even-numbered gear motor-generator 24, and an actuator 25.

The transmission 3 is configured as a so-called AMT (Automated Manual Transmission), and gear shifting is performed by an actuator 25 controlled by the TCU 12.

The differential device 22 transmits the driving force output by the transmission mechanism 21 to the drive wheels 4L, 4R via drive shafts 31L, 31R.

As shown in FIG. 2, the transmission mechanism 21 includes an input shaft 41, a cylindrical odd-numbered intermediate shaft 42, a cylindrical even-numbered intermediate shaft 43, and an output shaft 44. The input shaft 41, the odd-numbered intermediate shaft 42, the even-numbered intermediate shaft 43, and the output shaft 44 extend in the width direction of the vehicle 1 (hereinafter referred to as the vehicle width direction). The traveling direction of the vehicle 1 is the fore-and-aft direction, and the vehicle width direction is the left-and-right direction.

The input shaft 41 is connected to the crankshaft 2S of the engine 2 via the friction clutch 33, and the driving force (engine torque) of the engine 2 is transmitted to the input shaft 41 via the friction clutch 33.

When engaged, the friction clutch 33 mechanically connects the crankshaft 2S and the input shaft 41 to enable the transmission of driving force, and when disengaged, it mechanically separates the crankshaft 2S and the input shaft 41, preventing the transmission of driving force from the crankshaft 2S to the input shaft 41.

The odd-numbered stage intermediate shaft 42 is located outside the input shaft 41, is coaxial with the input shaft 41, and is rotatable relative to the input shaft 41. In other words, the input shaft 41 is inserted inside the cylindrical odd-numbered stage intermediate shaft 42, and the odd-numbered stage intermediate shaft 42 is supported by the input shaft 41 so as to be rotatable relative to the input shaft 41.

The even-stage intermediate shaft 43 is located outside the input shaft 41, is coaxial with the input shaft 41, and is rotatable relative to the input shaft 41. In other words, the input shaft 41 is inserted inside the cylindrical even-stage intermediate shaft 43, and the even-stage intermediate shaft 43 is supported by the input shaft 41 so as to be rotatable relative to the input shaft 41.

The even-numbered stage intermediate shaft 43 faces the odd-numbered stage intermediate shaft 42 in the axial direction of the input shaft 41 and is installed on the opposite side of the odd-numbered stage intermediate shaft 42 from the engine 2. In other words, from the left side of the input shaft 41 in the axial direction, the engine 2, odd-numbered stage intermediate shaft 42, and even-numbered stage intermediate shaft 43 are arranged in this order.

The input shaft 41, odd-numbered intermediate shaft 42, and even-numbered intermediate shaft 43 are installed coaxially and parallel to each other, and the input shaft 41, odd-numbered intermediate shaft 42, and even-numbered intermediate shaft 43 share the same central axis of rotation.

The output shaft 44 is installed parallel to the odd-numbered intermediate shaft 42 and the even-numbered intermediate shaft 43, extending leftward beyond the left end of the odd-numbered intermediate shaft 42 and rightward beyond the right end of the even-numbered intermediate shaft 43.

The odd-numbered intermediate shaft 42 and the output shaft 44 are configured to be able to transmit driving force via the first-speed gear pair 45 and the third-speed gear pair 47. In other words, the first-speed gear pair 45 and the third-speed gear pair 47 are configured to be able to connect the odd-numbered intermediate shaft 42 and the output shaft 44 so as to transmit driving force from the odd-numbered intermediate shaft 42 to the output shaft 44 and from the output shaft 44 to the odd-numbered intermediate shaft 42, thereby forming an odd-numbered gear pair having odd-numbered gears with different gear ratios.

The first-speed gear pair 45 has a first-speed input gear 45A and a third-speed input gear 47A that are rotatable integrally with the odd-speed intermediate shaft 42, and a first-speed output gear 45B and a third-speed output gear 47B that are rotatable relative to the output shaft 44 and mesh with the first-speed input gear 45A and the third-speed input gear 47A, respectively.

An odd-numbered-stage motor driven gear 50B is provided on the odd-numbered-stage intermediate shaft 42. The odd-numbered-stage motor driven gear 50B has a larger diameter than the third-speed input gear 47A, which in turn has a larger diameter than the first-speed input gear 45A.

An odd-numbered stage motor drive gear 50A is attached to the output shaft 23A of the odd-numbered stage motor generator 23, and the odd-numbered stage motor drive gear 50A meshes with the odd-numbered stage motor driven gear 50B.

The driving force of the odd-numbered stage motor generator 23 is transmitted from the odd-numbered stage motor drive gear 50A via the odd-numbered stage motor driven gear 50B to the odd-numbered stage intermediate shaft 42. In the axial direction of the input shaft 41, the odd-numbered stage motor generator 23 is disposed to the left of the odd-numbered stage motor drive gear 50A. In other words, in the axial position of the input shaft 41, the odd-numbered stage motor generator 23 is disposed in the same position as the first-speed input gear 45A or the third-speed input gear 47A.

The odd-numbered stage motor drive gear 50A has a smaller diameter than the odd-numbered stage motor driven gear 50B, and the rotational speed of the driving force transmitted from the odd-numbered stage motor generator 23 to the odd-numbered stage intermediate shaft 42 is reduced by the odd-numbered stage motor drive gear 50A and the odd-numbered stage motor driven gear 50B.

The first-speed output gear 45B has a larger diameter than the first-speed input gear 45A, and the third-speed output gear 47B has a smaller diameter than the third-speed input gear 47A.

The even-numbered intermediate shaft 43 and the output shaft 44 are configured to be able to transmit driving force via the second-speed gear pair 46 and the fourth-speed gear pair 48. In other words, the second-speed gear pair 46 and the fourth-speed gear pair 48 are configured to be able to connect the even-numbered intermediate shaft 43 and the output shaft 44 so as to transmit driving force from the even-numbered intermediate shaft 43 to the output shaft 44 and from the output shaft 44 to the even-numbered intermediate shaft 43, thereby forming an even-numbered gear pair having even-numbered gears with different gear ratios.

The second-speed gear pair 46 has a second-speed input gear 46A and a fourth-speed input gear 48A that are rotatable integrally with the even-speed intermediate shaft 43, and a second-speed output gear 46B and a fourth-speed output gear 48B that are rotatable relative to the output shaft 44 and mesh with the second-speed input gear 46A and the fourth-speed input gear 48A, respectively.

An even-speed motor driven gear 51B is provided on the even-speed intermediate shaft 43. The even-speed motor driven gear 51B has a larger diameter than the fourth-speed input gear 48A, which in turn has a larger diameter than the second-speed input gear 46A.

An even-stage motor drive gear 51A is attached to the output shaft 24A of the even-stage motor generator 24, and the even-stage motor drive gear 51A meshes with the even-stage motor driven gear 51B.

In the axial direction of the input shaft 41, the even-numbered motor-generator 24 is located to the right of the even-numbered motor drive gear 51A. In other words, in the axial position of the input shaft 41, the even-numbered motor-generator 24 is located in the same position as the fourth-speed input gear 48A or the second-speed input gear 46A.

The even-stage motor drive gear 51A has a smaller diameter than the even-stage motor driven gear 51B, and the rotational speed of the driving force transmitted from the even-stage motor generator 24 to the even-stage intermediate shaft 43 is reduced by the even-stage motor drive gear 51A and the even-stage motor driven gear 51B.

The second-speed output gear 46B has a larger diameter than the second-speed input gear 46A, and the fourth-speed output gear 48B has a smaller diameter than the fourth-speed input gear 48A.

The diameters of the input gears increase in the order of first-speed input gear 45A, second-speed input gear 46A, third-speed input gear 47A, and fourth-speed input gear 48A, while the diameters of the output gears decrease in the order of first-speed output gear 45B, second-speed output gear 46B, third-speed output gear 47B, and fourth-speed output gear 48B.

As a result, the gear ratio for first gear is the largest, followed by first, second, third, and fourth gears, which have decreasing gear ratios in that order. While the transmission 3 in this embodiment is configured with four forward gears, the total number of gears is not limited to four.

The first-speed input gear 45A and the third-speed input gear 47A form the odd-speed intermediate shaft side gears, and the first-speed output gear 45B and the third-speed output gear 47B form the odd-speed output shaft side gears. The second-speed input gear 46A and the fourth-speed input gear 48A form the even-speed intermediate shaft side gears, and the second-speed output gear 46B and the fourth-speed output gear 48B form the even-speed output shaft side gears.

A ring-shaped first dog clutch 52 is provided on the input shaft 41. The first dog clutch 52 is installed between the odd-numbered stage intermediate shaft 42 and the even-numbered stage intermediate shaft 43 in the axial direction of the input shaft 41, and is movable in the axial direction of the input shaft 41 and rotatable integrally with the input shaft 41.

The first dog clutch 52 has multiple dog teeth 52A on the left end and multiple dog teeth 52B on the right end.

A plurality of dog teeth 42A are formed on the right end (the end facing the first dog clutch 52) of the odd-numbered intermediate shaft 42, and a plurality of dog teeth 43A are formed on the left end (the end facing the first dog clutch 52) of the even-numbered intermediate shaft 43.

The first dog clutch 52 is moved axially of the input shaft 41 by the actuator 25.

When the actuator 25 moves the first dog clutch 52 from the neutral position toward the odd-numbered stage intermediate shaft 42 and switches it to the odd-numbered stage position where the dog teeth 52A mesh with the dog teeth 42A of the odd-numbered stage intermediate shaft 42, the input shaft 41 is connected to the odd-numbered stage intermediate shaft 42 via the first dog clutch 52.

As a result, the input shaft 41 and the odd-numbered intermediate shaft 42 rotate together, and the driving force of the engine 2 is transmitted from the input shaft 41 to the odd-numbered intermediate shaft 42.

When the actuator 25 moves the first dog clutch 52 from the neutral position toward the even-stage intermediate shaft 43 and switches it to the even-stage position where the dog teeth 52B mesh with the dog teeth 43A of the even-stage intermediate shaft 43, the input shaft 41 is connected to the even-stage intermediate shaft 43 via the first dog clutch 52.

As a result, the input shaft 41 and the even-numbered intermediate shaft 43 rotate together, and the driving force of the engine 2 is transmitted from the input shaft 41 to the even-numbered intermediate shaft 43.

When the first dog clutch 52 is in a neutral position where it is not connected to the odd-numbered stage intermediate shaft 42 or the even-numbered stage intermediate shaft 43, the input shaft 41 and the odd-numbered stage intermediate shaft 42 and the even-numbered stage intermediate shaft 43 rotate relative to each other, and the driving force of the engine 2 is not transmitted to the odd-numbered stage intermediate shaft 42 and the even-numbered stage intermediate shaft 43.

The odd-numbered stage motor driven gear 50B is located closest to the first dog clutch 52 in the axial direction of the odd-numbered stage intermediate shaft 42, and the first-speed input gear 45A and third-speed input gear 47A are located on the opposite side of the odd-numbered stage motor driven gear 50B from the first dog clutch 52.

In this embodiment, the odd-numbered motor driven gear 50B, first-speed input gear 45A, and third-speed input gear 47A are arranged so that their diameters gradually decrease as they move away from the first dog clutch 52 in the axial direction of the odd-numbered intermediate shaft 42.

The even-stage motor driven gear 51B is located closest to the first dog clutch 52 in the axial direction of the even-stage intermediate shaft 43, and the second-speed input gear 46A and fourth-speed input gear 48A are located on the opposite side of the even-stage motor driven gear 51B from the first dog clutch 52.

In this embodiment, the even-speed motor driven gear 51B, second-speed input gear 46A, and fourth-speed input gear 48A are arranged so that their diameters gradually decrease as they move away from the first dog clutch 52 in the axial direction of the even-speed intermediate shaft 43.

A ring-shaped second dog clutch 53 and a third dog clutch 54 are provided on the output shaft 44.

The second dog clutch 53 is installed between the first-speed output gear 45B and the third-speed output gear 47B in the axial direction of the output shaft 44, and is movable in the axial direction of the output shaft 44 and rotatable integrally with the output shaft 44.

The second dog clutch 53 has multiple dog teeth 53A on the left end and multiple dog teeth 53B on the right end.

Multiple dog teeth 45G are formed on the right end of the first-speed output gear 45B, and multiple dog teeth 47G are formed on the left end of the third-speed output gear 47B.

The second dog clutch 53 is moved axially of the output shaft 44 by the actuator 25.

When the actuator 25 moves the second dog clutch 53 from the neutral position toward the first-speed output gear 45B and the dog teeth 53A mesh with the dog teeth 45G of the first-speed output gear 45B, the first-speed output gear 45B is connected to the output shaft 44 via the second dog clutch 53.

As a result, the first-speed output gear 45B rotates integrally with the output shaft 44, enabling driving force to be transmitted between the odd-numbered intermediate shaft 42 and the output shaft 44 via the first-speed gear pair 45.

When the actuator 25 moves the second dog clutch 53 from the neutral position toward the third-speed output gear 47B and the dog teeth 53B mesh with the dog teeth 47G of the third-speed output gear 47B, the third-speed output gear 47B is connected to the output shaft 44 via the second dog clutch 53.

As a result, the third-speed output gear 47B rotates integrally with the output shaft 44, enabling driving force to be transmitted between the odd-numbered intermediate shaft 42 and the output shaft 44 via the third-speed gear pair 47.

The third dog clutch 54 is installed between the second-speed output gear 46B and the fourth-speed output gear 48B in the axial direction of the output shaft 44, and is movable in the axial direction of the output shaft 44 and rotatable integrally with the output shaft 44.

The third dog clutch 54 has multiple dog teeth 54A on the right end and multiple dog teeth 54B on the left end.

Multiple dog teeth 46G are formed on the left end of the second-speed output gear 46B, and multiple dog teeth 48G are formed on the right end of the fourth-speed output gear 48B.

The third dog clutch 54 is moved axially of the output shaft 44 by the actuator 25.

When the actuator 25 moves the third dog clutch 54 from the neutral position toward the second-speed output gear 46B and the dog teeth 54A mesh with the dog teeth 46G of the second-speed output gear 46B, the second-speed output gear 46B is connected to the output shaft 44 via the third dog clutch 54.

This causes the second-speed output gear 46B to rotate integrally with the output shaft 44, enabling driving force to be transmitted between the even-numbered intermediate shaft 43 and the output shaft 44 via the second-speed gear pair 46.

When the actuator 25 moves the third dog clutch 54 from the neutral position toward the fourth-speed output gear 48B and the dog teeth 54B mesh with the dog teeth 48G of the fourth-speed output gear 48B, the fourth-speed output gear 48B is connected to the output shaft 44 via the third dog clutch 54.

This causes the fourth-speed output gear 48B to rotate integrally with the output shaft 44, enabling driving force to be transmitted between the even-numbered intermediate shaft 43 and the output shaft 44 via the fourth-speed gear pair 48.

In other words, the transmission 3 of this embodiment can select either first or third gear between the odd-numbered intermediate shaft 42 and the output shaft 44, thereby establishing either first or third gear, and can select either second or fourth gear between the even-numbered intermediate shaft 43 and the output shaft 44, thereby establishing either second or fourth gear.

In the transmission 3 of this embodiment, when the gear is in first or third gear, the transmission path for the driving force of the engine 2 is a transmission path that transmits the force from the crankshaft 2S of the engine 2 to the output shaft 44 via the input shaft 41, the odd-numbered intermediate shaft 42, and the first-speed gear pair 45 or the third-speed gear pair 47.

When the gear is in second or fourth gear, the transmission path for the driving force of the engine 2 is from the crankshaft 2S of the engine 2 to the output shaft 44 via the input shaft 41, the even-numbered intermediate shaft 43, the second-speed gear pair 46 or the fourth-speed gear pair 48.

When the gear is in first or third gear, the transmission path for the driving force of the odd-numbered motor-generator 23 is from the odd-numbered motor-generator 23 to the output shaft 44 via the odd-numbered motor drive gear 50A, the odd-numbered motor driven gear 50B, the odd-numbered intermediate shaft 42, and the first-speed gear pair 45 or the third-speed gear pair 47.

When the gear is in second or fourth gear, the transmission path for the driving force of the even-numbered motor-generator 24 is from the even-numbered motor-generator 24 to the output shaft 44 via the even-numbered motor drive gear 51A, the even-numbered motor driven gear 51B, the even-numbered intermediate shaft 43, and the second-speed gear pair 46 or the fourth-speed gear pair 48.

In this embodiment, the first dog clutch 52 constitutes the first switching member, the second dog clutch 53 constitutes the second switching member, and the third dog clutch 54 constitutes the third switching member.

As explained above, by controlling the switching state of the second dog clutch 53 and the third dog clutch 54 and the driving force of the odd-numbered motor-generator 23 and the even-numbered motor-generator 24, it is possible to drive the vehicle 1 using each gear pair (45, 46, 47, 48). For ease of explanation, unless otherwise specified, "gear stage" refers to the gear stage of the transmission path that transmits the driving force of the engine 2, and "shifting" refers to a change in the transmission path that transmits the driving force of the engine 2.

A final drive gear 55 is provided at the left end of the output shaft 44. The differential device 22 has a final driven gear 22A that meshes with the final drive gear 55, and a differential mechanism 22B attached to the final driven gear 22A.

Drive shafts 31L and 31R are connected to the differential mechanism 22B. The differential device 22 distributes the driving force of the engine 2 to the drive shafts 31L and 31R via the differential mechanism 22B and transmits it to the drive wheels 4L and 4R.

The HCU 10, ECU 11, TCU 12, and BMS 13 are each composed of a computer unit equipped with a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), flash memory for storing backup data, and input and output ports.

The ROM of these computer units stores various constants, maps, etc., as well as programs that enable the computer units to function as the HCU 10, ECU 11, TCU 12, and BMS 13, respectively.

In other words, the CPU executes programs stored in the ROM using the RAM as a work area, causing these computer units to function as the HCU 10, ECU 11, TCU 12, and BMS 13 in this embodiment, respectively.

The ECU 11 controls the engine 2's intake air volume, fuel injection volume, injection timing, ignition timing, etc., to achieve the engine torque based on commands from the HCU 10.

The TCU 12 controls the actuator 25 based on commands from the HCU 10, moving the first dog clutch 52, the second dog clutch 53, and the third dog clutch 54 to the neutral position, a shift position where an odd-numbered gear is established, and a shift position where an even-numbered gear is established.

The BMS 13 monitors the status of the battery 16 and transmits information such as the remaining capacity of the battery 16 (SOC: State of Charge) to the HCU 10.

In response to commands from the HCU 10, the odd-numbered stage inverter 14 and the even-numbered stage inverter 15 convert the DC power supplied from the battery 16 into three-phase AC power and supply it to the even-numbered stage motor generator 24 and the odd-numbered stage motor generator 23 so as to generate the motor torque according to the commands from the HCU 10, or convert the three-phase AC power generated by the odd-numbered stage motor generator 23 and the even-numbered stage motor generator 24 into DC power to charge the battery 16.

The odd-numbered stage inverter 14 and the even-numbered stage inverter 15 transmit information on the rotational speeds (rotational speeds) of the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 to the HCU 10. The battery 16 is composed of a secondary battery, such as a lithium-ion battery.

The odd-numbered stage motor generators 23 and even-numbered stage motor generators 24 function as electric motors that generate driving force for the vehicle 1 using power supplied from the battery 16 via the odd-numbered stage inverter 14 and even-numbered stage inverter 15, and as generators that generate regenerative power using the rotational force (reverse driving force) input from the drive wheels 4L, 4R via the differential device 22.

In this embodiment, the odd-numbered stage motor-generator 23 constitutes an odd-numbered stage rotating electric machine, and the even-numbered stage motor-generator 24 constitutes an even-numbered stage rotating electric machine.

As shown in Figure 1, the HCU 10 is connected to a shift position sensor 56, an accelerator opening sensor 57, and a vehicle speed sensor 58. The shift position sensor 56 detects the shift position selected by the driver's operation of the shift lever 59.

The shift position can be selected from, for example, P range (parking position), N range (neutral position), R range (reverse driving position), D range (forward driving position), or B range (engine braking position). B range is a shift position that generates greater engine braking than D range.

The shift position sensor 56 sends a signal to the HCU 10 corresponding to the shift position selected by the driver.

The accelerator position sensor 57 detects the position of the accelerator pedal 60 operated by the driver (accelerator operation amount) and sends a signal corresponding to the accelerator position to the HCU 10. The vehicle speed sensor 58 detects the speed of the vehicle 1 (vehicle speed) and sends a signal corresponding to the vehicle speed to the HCU 10.

The HCU 10 calculates the driving force required by the driver (driver requested torque) based on the position of the shift lever 59 transmitted from the shift position sensor 56, the accelerator pedal position transmitted from the accelerator pedal position sensor 57, and the vehicle speed transmitted from the vehicle speed sensor 58, determines whether the vehicle is in EV mode or HEV mode, and switches the driving mode of the vehicle 1 to either EV mode or HEV mode.

EV mode is a mode in which the vehicle travels using the odd-numbered motor-generator 23 or the even-numbered motor-generator 24 without using the driving force of the engine 2. HEV mode is a mode in which the engine 2 is in an operating state and the driving force of the engine 2 can be transmitted to the drive wheels (4L, 4R).

The HCU 10 issues commands to the ECU 11, TCU 12, odd-stage inverter 14, and even-stage inverter 15 so that the remaining capacity of the battery 16 matches the driver-requested torque within a predetermined range in EV mode or HEV mode.

The odd-stage inverter 14 and the even-stage inverter 15 control the driving force (motor torque) of the odd-stage motor-generator 23 and the even-stage motor-generator 24 based on commands from the HCU 10, and the ECU 11 controls the engine torque based on commands from the HCU 10.

The TCU 12 controls the actuator 25 based on commands from the HCU 10 to switch between the first dog clutch 52, the second dog clutch 53, and the third dog clutch 54, thereby performing gear changes.

EV mode is a driving mode in which the engine 2 is stopped and the vehicle 1 is driven by satisfying the driver's requested torque using at least one of the odd-numbered motor-generator 23 and the even-numbered motor-generator 24.

In EV mode, engine 2 is not operating, so engine speed is maintained at zero.

HEV mode is a driving mode in which the engine 2 is operated and the driver's requested torque is satisfied by at least the engine torque out of the engine torque and the motor torque of the odd-numbered motor-generator 23 and the even-numbered motor-generator 24, causing the vehicle 1 to travel.

In HEV mode, the vehicle runs using only engine torque, or runs using engine torque and at least one motor torque from the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 (so-called motor assist).

When the driving mode is changed from EV mode to HEV mode, the HCU 10 controls the TCU 12 to operate the actuator 25, thereby switching the first dog clutch 52 from the neutral position to the odd-numbered stage intermediate shaft 42 or the even-numbered stage intermediate shaft 43, and starting the engine 2 using either the odd-numbered stage motor-generator 23 or the even-numbered stage motor-generator 24.

The HCU 10 controls either the odd-numbered stage motor-generator 23 or the even-numbered stage motor-generator 24 and the ECU 11, and drives the vehicle 1 using the driving force of the other of the odd-numbered stage motor-generator 23 or the even-numbered stage motor-generator 24 until the gear to which driving force is transmitted from the engine 2 is established.

In addition, when the driving mode is switched from EV mode to HEV mode, the HCU 10 controls the second dog clutch 53 or the third dog clutch 54 to switch to the neutral position when the driving force of the odd-numbered stage motor-generator 23 or the driving force of the even-numbered stage motor-generator 24 reaches a predetermined value of zero.

Then, the HCU 10 controls the driving force of the odd-numbered stage motor-generator 23 or the even-numbered stage motor-generator 24 so that the rotation speed of the odd-numbered stage motor-generator 23 or the even-numbered stage motor-generator 24 becomes a predetermined value, zero, and engages the first dog clutch 52 with the odd-numbered stage intermediate shaft 42 or the even-numbered stage intermediate shaft 43, thereby starting the engine 2 with the odd-numbered stage motor-generator 23 or the even-numbered stage motor-generator 24.

In addition, when establishing an odd gear after starting the engine 2, the HCU 10 controls the driving force of the engine 2 or the driving force of the odd-speed motor-generator 23 when connecting the first-speed output gear 45B or the third-speed output gear 47B to the output shaft 44 using the second dog clutch 53, thereby performing synchronization control to synchronize the rotation speed of the first-speed output gear 45B or the third-speed output gear 47B with the rotation speed of the output shaft 44, and once the rotation speed of the first-speed output gear 45B or the third-speed output gear 47B and the rotation speed of the output shaft 44 are synchronized, the second dog clutch 53 connects the first-speed output gear 45B or the third-speed output gear 47B to the output shaft 44.

On the other hand, when establishing an even gear after starting the engine 2, when the second-speed output gear 46B or fourth-speed output gear 48B is connected to the output shaft 44 by the third dog clutch 54, synchronization control is performed to control the driving force of the engine 2 or the driving force of the even-speed motor-generator 24 to synchronize the rotation speed of the second-speed output gear 46B or fourth-speed output gear 48B with the rotation speed of the output shaft 44, and once the rotation speed of the second-speed output gear 46B or fourth-speed output gear 48B and the rotation speed of the output shaft 44 are synchronized, the second-speed output gear 46B or fourth-speed output gear 48B is connected to the output shaft 44 by the third dog clutch 54.

In this embodiment, the HCU 10, ECU 11, TCU 12, odd-stage inverter 14, and even-stage inverter 15 constitute the control unit 30.

Based on the driving modes shown in Figure 3, the switching control of the first dog clutch 52, second dog clutch 53, and third dog clutch 54 in EV mode and HEV mode will be explained.

1) EV Neutral Mode This is the EV mode, and is the mode when the shift position of the shift lever 59 is in the N range or the P range. The first dog clutch 52, the second dog clutch 53, and the third dog clutch 54 are in the neutral position.

As a result, the engine 2, odd-numbered stage motor generators 23, and even-numbered stage motor generators 24 are disconnected from the drive wheels 4L, 4R, and engine torque and motor torque are not transmitted from the engine 2, odd-numbered stage motor generators 23, and even-numbered stage motor generators 24 to the drive wheels 4L, 4R.

In EV neutral mode, the second dog clutch 53 and the third dog clutch 54 are in the neutral position, but if the motor torque of the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 is controlled to zero, the second dog clutch 53 and the third dog clutch 54 do not need to be in the neutral position.

2) EV1-EV2 Mode This is the EV mode, and is the mode when the shift position of the shift lever 59 is in the D range or the R range.

The first dog clutch 52 is in the neutral position, the second dog clutch 53 is in a position that establishes first gear, and the third dog clutch 54 is in a position that establishes second gear.

In EV1-EV2 mode, when the vehicle 1 is traveling forward, the motor torque of the odd-numbered motor-generator 23 is transmitted from the odd-numbered intermediate shaft 42 to the output shaft 44 via the first-speed gear pair 45, and the motor torque of the even-numbered motor-generator 24 is transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the second-speed gear pair 46, and the motor torque of the motor-generators 23, 24 is transmitted to the drive wheels 4L, 4R.

On the other hand, when the vehicle 1 is traveling in reverse, the odd-numbered motor-generators 23 and even-numbered motor-generators 24 rotate in the opposite direction to when the vehicle is traveling forward, and the motor torque of the odd-numbered motor-generators 23 and even-numbered motor-generators 24 is transmitted to the drive wheels 4L, 4R via the same drive force transmission path as when the vehicle is traveling forward.

When the vehicle 1 decelerates, the rotational force of the drive wheels 4L, 4R is transmitted from the differential device 22 to the output shaft 44.

The rotational force transmitted to the output shaft 44 is transmitted from the first-speed gear pair 45 via the odd-speed intermediate shaft 42 to the odd-speed motor-generator 23, and from the second-speed gear pair 46 via the even-speed intermediate shaft 43 to the even-speed motor-generator 24, thereby generating regenerative power in the motor-generators 23 and 24.

3) EV2 Mode This is the EV mode, which is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 and the second dog clutch 53 are switched to their neutral positions, and the third dog clutch 54 is switched to a position that establishes second gear.

In EV2 mode, when the vehicle 1 is traveling forward, the motor torque of the even-numbered motor-generator 24 is transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the second-speed gear pair 46, and the motor torque of the even-numbered motor-generator 24 is transmitted to the drive wheels 4L and 4R.

EV2 mode is temporarily implemented when switching from EV1-EV2 mode to EV2-EV3 mode, and the drive wheels 4L and 4R are driven by the motor torque of the even-numbered motor generator 24 while the gear shift is being switched from 1st to 3rd gear.

4) EV2-EV3 Mode This is the EV mode, and is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 is in the neutral position, the second dog clutch 53 is in a position that establishes third gear, and the third dog clutch 54 is in a position that establishes second gear.

In EV2-EV3 mode, when the vehicle 1 is traveling forward, the motor torque of the odd-numbered motor-generator 23 is transmitted from the odd-numbered intermediate shaft 42 to the output shaft 44 via the third-speed gear pair 47, and the motor torque of the even-numbered motor-generator 24 is transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the second-speed gear pair 46, and the motor torque of the motor-generators 23, 24 is transmitted to the drive wheels 4L, 4R.

When the vehicle 1 decelerates, the rotational force of the drive wheels 4L, 4R is transmitted from the differential device 22 to the output shaft 44.

The rotational force transmitted to the output shaft 44 is transmitted from the third-speed gear pair 47 to the odd-speed motor-generator 23 via the odd-speed intermediate shaft 42, and from the second-speed gear pair 46 to the even-speed motor-generator 24 via the even-speed intermediate shaft 43, thereby generating regenerative power in the motor-generators 23 and 24.

EV2-EV3 mode is not implemented in R range because there is no need to increase vehicle speed when vehicle 1 is traveling in reverse.

5) EV3 Mode This is the EV mode, which is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 and the third dog clutch 54 are switched to their neutral positions, and the second dog clutch 53 is switched to a position that establishes third gear.

In EV3 mode, when the vehicle 1 is traveling forward, the motor torque of the odd-numbered motor-generator 23 is transmitted to the output shaft 44 via the third-speed gear pair 47, and the motor torque of the odd-numbered motor-generator 23 is transmitted to the drive wheels 4L and 4R.

EV3 mode is temporarily implemented when switching from EV2-EV3 mode to EV3-EV4 mode, and the drive wheels 4L and 4R are driven by the motor torque of the odd-numbered stage motor generator 23 while the gear shift is being switched from second to fourth gear.

6) EV3-EV4 Mode This is the EV mode, and is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 is in the neutral position, the second dog clutch 53 is in a position that establishes third gear, and the third dog clutch 54 is in a position that establishes fourth gear.

In EV3-EV4 mode, when the vehicle 1 is traveling forward, the motor torque of the odd-numbered motor-generator 23 is transmitted from the odd-numbered intermediate shaft 42 to the output shaft 44 via the third-speed gear pair 47, and the motor torque of the even-numbered motor-generator 24 is transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the fourth-speed gear pair 48, and the motor torque of the motor-generators 23, 24 is transmitted to the drive wheels 4L, 4R.

When the vehicle 1 decelerates, the rotational force of the drive wheels 4L, 4R is transmitted from the differential device 22 to the output shaft 44.

The rotational force transmitted to the output shaft 44 is transmitted from the third-speed gear pair 47 to the odd-speed motor-generator 23 via the odd-speed intermediate shaft 42, and from the fourth-speed gear pair 48 to the even-speed motor-generator 24 via the even-speed intermediate shaft 43, thereby generating regenerative power in the motor-generators 23 and 24.

EV3-EV4 mode is not implemented in R range because there is no need to increase vehicle speed when vehicle 1 is traveling in reverse.

7) HEV Neutral Mode This is the HEV mode, and is the mode when the shift position of the shift lever 59 is in the N range or P range.

The first dog clutch 52, the second dog clutch 53, and the third dog clutch 54 are in the neutral position.

As a result, the engine 2, odd-numbered stage motor generators 23, and even-numbered stage motor generators 24 are disconnected from the drive wheels 4L, 4R, and engine torque and motor torque are not transmitted from the engine 2, odd-numbered stage motor generators 23, and even-numbered stage motor generators 24 to the drive wheels 4L, 4R.

In HEV neutral mode, the second dog clutch 53 and the third dog clutch 54 are in the neutral position, but if the motor torque of the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 is controlled to zero, the second dog clutch 53 and the third dog clutch 54 do not need to be in the neutral position.

8) HEV Neutral Power Generation Mode This is the HEV mode, the shift position of the shift lever 59 is in the N range or P range, and the motor is generating power.

The first dog clutch 52 is in the even-numbered gear position, and the second dog clutch 53 and the third dog clutch 54 are in the neutral position.

In HEV neutral power generation mode, the input shaft 41 is connected to the even-numbered intermediate shaft 43 by the first dog clutch 52, and engine torque is transmitted from the input shaft 41 via the even-numbered intermediate shaft 43 to the even-numbered motor-generator 24, causing the even-numbered motor-generator 24 to generate power.

In the HEV neutral power generation mode, the second dog clutch 53 and the third dog clutch 54 are in the neutral position, but if the motor torque of the odd-numbered stage motor generator 23 is controlled to zero, the second dog clutch 53 does not need to be in the neutral position.

9) HEV1-EV1-EV2 Mode This is the HEV mode, and is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 is switched to an odd-numbered gear position, the second dog clutch 53 is switched to a position that establishes first gear, and the third dog clutch 54 is switched to a position that establishes second gear.

In HEV1-EV1-EV2 mode, when the vehicle 1 is traveling forward, the input shaft 41 is connected to the odd-numbered intermediate shaft 42.

As a result, engine torque and motor torque of the odd-numbered stage motor-generator 23 are transmitted from the odd-numbered stage intermediate shaft 42 to the output shaft 44 via the first-speed gear pair 45, and motor torque of the even-numbered stage motor-generator 24 is transmitted from the even-numbered stage intermediate shaft 43 to the output shaft 44 via the second-speed gear pair 46.

As a result, the drive wheels 4L, 4R are driven by at least the engine 2 and the odd-numbered stage motor-generator 23. Furthermore, when assisting the engine 2, both the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 are driven.

When the odd-numbered stage motor-generator 23 generates electricity using the engine torque available during driving, the engine torque is transmitted from the odd-numbered stage intermediate shaft 42 to the odd-numbered stage motor-generator 23. Also, when the even-numbered stage motor-generator 24 generates electricity using the engine torque available during driving, the engine torque is transmitted from the odd-numbered stage intermediate shaft 42 to the output shaft 44 via the first-speed gear pair 45, and then to the even-numbered stage motor-generator 24 via the second-speed gear pair 46 and the even-numbered stage intermediate shaft 43.

When the odd-numbered stage motor-generators 23 and even-numbered stage motor-generators 24 are generating electricity regeneratively, power is transmitted from the output shaft 44 via the first-speed gear pair 45 to the odd-numbered stage intermediate shaft 42 to the odd-numbered stage motor-generator 23, and from the output shaft 44 via the second-speed gear pair 46 and the even-numbered stage intermediate shaft 43 to the even-numbered stage motor-generator 24.

10) HEV2-EV1-EV2 Mode This is the HEV mode, and is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 is switched to an even-numbered gear position, the second dog clutch 53 is switched to a position that establishes first gear, and the third dog clutch 54 is switched to a position that establishes second gear.

In HEV2-EV1-EV2 mode, when the vehicle 1 is traveling forward, the input shaft 41 is connected to the even-numbered intermediate shaft 43.

As a result, engine torque and motor torque of the even-numbered motor-generator 24 are transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the second-speed gear pair 46, and motor torque of the odd-numbered motor-generator 23 is transmitted from the odd-numbered intermediate shaft 42 to the output shaft 44 via the first-speed gear pair 45.

As a result, the drive wheels 4L, 4R are driven by at least the engine 2 and the even-numbered motor-generator 24. Furthermore, when assisting the engine 2, both the odd-numbered motor-generator 23 and the even-numbered motor-generator 24 are driven.

When the even-numbered motor-generator 24 generates electricity using the engine torque available during driving, the engine torque is transmitted from the even-numbered intermediate shaft 43 to the even-numbered motor-generator 24. When the odd-numbered motor-generator 23 generates electricity using the engine torque available during driving, the engine torque is transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the second-speed gear pair 46, and then from the output shaft 44 to the odd-numbered motor-generator 23 via the first-speed gear pair 45 and the odd-numbered intermediate shaft 42.

Note that regenerative power generation by the odd-numbered motor-generator 23 and even-numbered motor-generator 24 is the same as in HEV1-EV1-EV2 mode.

11) HEV2-EV3-EV2 Mode This is the HEV mode, and is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 is switched to an even-numbered gear position, the second dog clutch 53 is switched to a position that establishes third gear, and the third dog clutch 54 is switched to a position that establishes second gear.

In HEV2-EV3-EV2 mode, when the vehicle 1 is traveling forward, the input shaft 41 is connected to the even-numbered intermediate shaft 43.

As a result, engine torque and motor torque of the even-numbered motor-generator 24 are transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the second-speed gear pair 46, and motor torque of the odd-numbered motor-generator 23 is transmitted from the odd-numbered intermediate shaft 42 to the output shaft 44 via the third-speed gear pair 47.

When assisting the engine 2, both the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 are driven.

Power generation using a portion of the engine torque is performed by only the even-numbered stage motor-generator 24, or by both the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24.

12) HEV3-EV3-EV2 Mode This is the HEV mode, and is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 is switched to an odd-numbered gear position, the second dog clutch 53 is switched to a position that establishes third gear, and the third dog clutch 54 is switched to a position that establishes second gear.

In HEV3-EV3-EV2 mode, when the vehicle 1 is traveling forward, the input shaft 41 is connected to the odd-numbered stage intermediate shaft 42.

As a result, engine torque and motor torque of the odd-numbered stage motor-generator 23 are transmitted from the odd-numbered stage intermediate shaft 42 to the output shaft 44 via the third-speed gear pair 47, and motor torque of the even-numbered stage motor-generator 24 is transmitted from the even-numbered stage intermediate shaft 43 to the output shaft 44 via the second-speed gear pair 46.

When assisting the engine 2, both the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 are driven.

Power generation using a portion of the engine torque is performed by only the odd-numbered stage motor-generator 23, or by both the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24.

13) HEV3-EV3-EV4 Mode This is the HEV mode, and is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 is switched to an odd-numbered gear position, the second dog clutch 53 is switched to a position that establishes third gear, and the third dog clutch 54 is switched to a position that establishes fourth gear.

In HEV3-EV3-EV4 mode, when the vehicle 1 is traveling forward, the input shaft 41 is connected to the odd-numbered stage intermediate shaft 42.

As a result, engine torque and motor torque of the odd-numbered stage motor-generator 23 are transmitted from the odd-numbered stage intermediate shaft 42 to the output shaft 44 via the third-speed gear pair 47, and motor torque of the even-numbered stage motor-generator 24 is transmitted from the even-numbered stage intermediate shaft 43 to the output shaft 44 via the fourth-speed gear pair 47.

When assisting the engine 2, both the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 are driven.

Power generation using a portion of the engine torque is performed by only the odd-numbered stage motor-generator 23, or by both the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24.

14) HEV4-EV3-EV4 Mode This is the HEV mode, and is the mode when the shift position of the shift lever 59 is in the D range.

The first dog clutch 52 is switched to an even-numbered gear position, the second dog clutch 53 is switched to a position that establishes third gear, and the third dog clutch 54 is switched to a position that establishes fourth gear.

In HEV4-EV3-EV4 mode, when the vehicle 1 is traveling forward, the input shaft 41 is connected to the even-numbered intermediate shaft 43.

As a result, engine torque and motor torque of the even-numbered motor-generator 24 are transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the fourth-speed gear pair 47, and motor torque of the odd-numbered motor-generator 23 is transmitted from the odd-numbered intermediate shaft 42 to the output shaft 44 via the third-speed gear pair 47.

When assisting the engine 2, both the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 are driven.

Power generation using a portion of the engine torque is performed by only the even-numbered stage motor-generator 24, or by both the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24.

15) EV1 series mode This is the HEV mode, and is the mode when the shift position of the shift lever 59 is in the D range or the R range. In this mode, the motor torque of the odd-numbered motor-generator 23 is transmitted to the output shaft 44 via the first gear pair 45, causing the vehicle 1 to travel. The engine torque is transmitted to the even-numbered motor-generator 24 via the even-numbered intermediate shaft 43, causing the even-numbered motor-generator 24 to generate electricity.

The first dog clutch 52 is in the even-numbered gear position, the second dog clutch 53 is in the position that establishes first gear, and the third dog clutch 54 is in the neutral position.

In EV1 series mode, when the vehicle 1 is traveling forward, the motor torque of the odd-numbered motor generator 23 is transmitted from the odd-numbered intermediate shaft 42 to the output shaft 44 via the first-speed gear pair 45.

On the other hand, when the vehicle 1 is traveling in reverse, the odd-numbered motor-generator 23 rotates in the opposite direction to when the vehicle 1 is traveling forward, and the motor torque of the odd-numbered motor-generator 23 is transmitted to the output shaft 44 via the first-speed gear pair 45.

When the vehicle 1 decelerates, the rotational force of the drive wheels 4L, 4R is transmitted from the differential device 22 to the odd-numbered stage motor-generator 23 via the output shaft 44, first-speed gear pair 45, and odd-numbered stage intermediate shaft 42, causing the odd-numbered stage motor-generator 23 to generate regenerative power.

When the even-numbered stage motor-generator 24 is generating power, engine torque is transmitted from the input shaft 41 to the even-numbered stage motor-generator 24 via the even-numbered stage intermediate shaft 43.

EV1 Series mode is primarily used when starting in D range in HEV mode, or when reversing in R range in HEV mode.

The EV1 series mode is also used as a temporary mode to start engine 2 when transitioning from the EV1-EV2 mode in the EV mode to the HEV2-EV1-EV2 mode in the HEV mode.

16) EV2 series mode This is an HEV mode, and is the mode when the shift lever 59 is in the D range. In this mode, the vehicle 1 runs using the even-numbered motor-generators 24, and the odd-numbered motor-generators 23 generate electricity using engine torque.

The first dog clutch 52 is switched to an odd-numbered gear position, the second dog clutch 53 is switched to a neutral position, and the third dog clutch 54 is switched to a position that establishes second gear.

In EV2 series mode, when the vehicle 1 is traveling forward, the motor torque of the even-numbered motor generator 24 is transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the second-speed gear pair 46.

When the vehicle 1 decelerates, the rotational force of the drive wheels 4L, 4R is transmitted from the differential device 22 to the even-numbered motor-generator 24 via the output shaft 44, second-speed gear pair 46, and even-numbered intermediate shaft 43, causing the even-numbered motor-generator 24 to generate regenerative power.

When the odd-numbered stage motor-generator 23 is generating power, engine torque is transmitted from the input shaft 41 to the odd-numbered stage motor-generator 23 via the odd-numbered stage intermediate shaft 42.

The EV2 series mode is also used as a temporary mode to start engine 2 when transitioning from the EV1-EV2 mode in the EV mode to the HEV1-EV1-EV2 mode in the HEV mode or the HEV3-EV3-EV2 mode in the HEV mode.

17) EV3 Series Mode This is an HEV mode, and is the mode when the shift lever 59 is in the D range. In this mode, the vehicle 1 runs using the odd-numbered motor-generators 23, and the even-numbered motor-generators 24 generate electricity using engine torque.

The first dog clutch 52 is in the even-numbered gear position, the second dog clutch 53 is in the position that establishes third gear, and the third dog clutch 54 is in the neutral position.

In EV3 series mode, when the vehicle 1 is traveling forward, the motor torque of the odd-numbered motor generator 23 is transmitted from the odd-numbered intermediate shaft 42 to the output shaft 44 via the third-speed gear pair 47.

When the vehicle 1 decelerates, the rotational force of the drive wheels 4L, 4R is transmitted from the differential device 22 to the odd-numbered stage motor-generator 23 via the output shaft 44, the third-speed gear pair 47, and the odd-numbered stage intermediate shaft 42, causing the odd-numbered stage motor-generator 23 to generate regenerative power.

When the even-numbered stage motor-generator 24 is generating power, engine torque is transmitted from the input shaft 41 to the even-numbered stage motor-generator 24 via the even-numbered stage intermediate shaft 43.

The EV3 series mode is also used as a temporary mode to start engine 2 when transitioning from the EV2-EV3 mode in the EV mode to the HEV2-EV3-EV2 mode in the HEV mode or the HEV4-EV3-EV4 mode in the HEV mode.

18) EV4 series mode This is an HEV mode, and is the mode when the shift lever 59 is in the D range. In this mode, the vehicle 1 runs using the even-numbered motor-generators 24, and the odd-numbered motor-generators 23 generate electricity using engine torque.

The first dog clutch 52 is switched to an odd-numbered gear position, the second dog clutch 53 is switched to a neutral position, and the third dog clutch 54 is switched to a position that establishes fourth gear.

In EV4 series mode, when the vehicle 1 is traveling forward, the motor torque of the even-numbered motor-generator 24 is transmitted from the even-numbered intermediate shaft 43 to the output shaft 44 via the fourth-speed gear pair 48.

When the vehicle 1 decelerates, the rotational force of the drive wheels 4L, 4R is transmitted from the differential device 22 to the even-numbered motor-generator 24 via the output shaft 44, the fourth-speed gear pair 48, and the even-numbered intermediate shaft 43, causing the even-numbered motor-generator 24 to generate regenerative power.

When the odd-numbered stage motor-generator 23 is generating power, engine torque is transmitted from the input shaft 41 to the odd-numbered stage motor-generator 23 via the odd-numbered stage intermediate shaft 42.

EV4 series mode is also used as a temporary mode to start engine 2 when transitioning from EV3-EV4 mode in EV mode to HEV3-EV3-EV4 mode in HEV mode.

The driving mode transition control executed by the control unit 30 of the engine 2 and transmission 3 configured as described above will be explained based on the timing charts in Figures 4 to 6. Driving mode transition refers to a transition from EV mode to HEV mode.

The timing charts in Figures 4 to 6 show, from top to bottom, the rotation speeds (rotation speeds of the engine 2, odd-numbered motor generator 23 (designated MG1), and even-numbered motor generator 24 (designated MG2)), vehicle speed, torque (driver requested torque, engine torque, motor torque), the switching position of the first dog clutch 52, the switching position of the second dog clutch 53, and the switching position of the third dog clutch 54, and the horizontal axis represents the passage of time.

Note that the rotation speed indicates the state of change, not a specific value.

In the timing charts of Figures 4 to 6, vehicle speed and driver requested torque are shown by solid lines, and engine speed and engine torque are shown by dashed lines. Also, in the timing charts of Figures 4 to 6, the rotation speed and motor torque of the odd-numbered stage motor-generator 23 are shown by dashed lines, and the rotation speed and motor torque of the even-numbered stage motor-generator 24 are shown by dashed lines.

First, the driving mode transition control will be explained based on the timing chart in Figure 4. The timing chart in Figure 4 shows an example in which, when the driving mode is transitioned from EV mode to HEV mode, the engine 2 is started by the odd-numbered stage motor generator 23, and after engine 2 has started, the engine 2 is driven by the odd-numbered stage.

When traveling in EV mode, the friction clutch 33 is disengaged, and the crankshaft 2S and input shaft 41 are mechanically separated.

At time t0 in Figure 4, the vehicle 1 is stopped in D range. At this time, the first dog clutch 52 is in the neutral position, the second dog clutch 53 is switched to first gear, and the third dog clutch 54 is switched to second gear, and the driving mode is EV1-EV2 mode.

When the driver depresses the accelerator pedal 60 at time t1, the HCU 10 issues a command to the ECU 11, causing the odd-numbered stage inverter 14 and the even-numbered stage inverter 15 to generate motor torque from the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24. This causes the vehicle 1 to begin accelerating.

When the motor torque of the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 increases, the HCU 10 begins transitioning to the EV2 series at time t2.

At time t2, the HCU 10 reduces the motor torque of the odd-numbered stage motor-generators 23 toward zero and increases the motor torque of the even-numbered stage motor-generators 24 using the even-numbered stage inverter 15, compensating for the decrease in motor torque of the odd-numbered stage motor-generators 23. In other words, the motor torque of the even-numbered stage motor-generators 24 is increased by the amount of the decrease in motor torque of the odd-numbered stage motor-generators 23.

From then on, the vehicle 1 will be driven by the even-numbered motor-generator 24 until the engine 2 switches to HEV mode.

When the motor torque of the odd-numbered stage motor-generator 23 becomes zero (time t3), the HCU 10 controls the TCU 12 to switch the second dog clutch 53 to the neutral position, and controls the motor torque of the odd-numbered stage motor-generator 23 using the odd-numbered stage inverter 14 so that the rotation speed of the odd-numbered stage motor-generator 23 becomes zero.

In other words, the HCU 10 reduces the rotation speed of the odd-numbered stage intermediate shaft 42. In the example of FIG. 4, the HCU 10 applies back torque to the odd-numbered stage motor-generator 23 to reduce the rotation speed of the odd-numbered stage motor-generator 23.

When the rotation speed of the odd-numbered stage motor-generator 23 reaches zero (time t4), the HCU 10 controls the TCU 12 to switch the first dog clutch 52 from the neutral position to the odd-numbered stage position, and then engages the friction clutch 33 to mechanically connect the crankshaft 2S and the input shaft 41.

At this time, driving force is transmitted from the odd-numbered motor generator 23 to the input shaft 41 via the odd-numbered motor drive gear 50A, the odd-numbered motor driven gear 50B, and the odd-numbered intermediate shaft 42. As a result, the motor torque of the odd-numbered motor generator 23 is transmitted from the input shaft 41 to the crankshaft 2S via the friction clutch 33, and the engine 2 is started.

At t5, the engine 2 has finished starting, and the driving force of the engine 2 is transmitted to the odd-numbered stage motor generator 23 via the input shaft 41, odd-numbered stage intermediate shaft 42, odd-numbered stage motor driven gear 50B, and odd-numbered stage motor drive gear 50A, and the odd-numbered stage motor generator 23 begins generating electricity.

At time t6, to transition to HEV3-EV3-EV2 mode, the HCU 10 controls the engine torque and the motor torque of the odd-numbered motor-generator 23 so that the rotation speed of the output shaft 44 and the rotation speed of the third-speed output gear 47B match, thereby performing synchronization control of the output shaft 44 and the third-speed output gear 47B.

In the example shown in Figure 4, the HCU 10 controls the ECU 11 to increase engine torque, and the odd-numbered motor generator 23, which is generating electricity, reduces the torque for generating electricity.

When the rotation speed of the output shaft 44 and the rotation speed of the third-speed output gear 47B match (time t7), the HCU 10 controls the TCU 12 to switch the second dog clutch 53 from the neutral position to a position that establishes third gear.

Here, the rotation speed of the output shaft 44 is controlled by the motor torque of the even-numbered motor-generator 24. The rotation speed of the third-speed output gear 47B is controlled by the engine torque and the motor torque of the odd-numbered motor-generator 23.

The HCU 10 calculates the rotation speed of the output shaft 44 from the rotation speed of the even-numbered motor generator 24, the reduction ratio of the even-numbered motor drive gear 51A and the even-numbered motor driven gear 51B, and the gear ratio (gear ratio) of the second-speed gear pair 46 and the fourth-speed gear pair 48.

The HCU 10 also calculates the rotation speed of the third-speed output gear 47B based on the rotation speed of the odd-speed motor generator 23, the reduction ratio of the odd-speed motor drive gear 50A and the odd-speed motor driven gear 50B, and the gear ratio (gear ratio) of the third-speed output gear pair 47.

After switching the second dog clutch 53 from the neutral position to a position that establishes third gear, the HCU 10 controls the even-stage inverter 15 to reduce the motor torque of the even-stage motor generator 24 and increase the engine torque to match the driver-requested torque, in order to switch from vehicle 1 running using the even-stage motor generator 24 to vehicle 1 running using the engine 2.

At time t8, the transition from EV mode to HEV mode is completed. Note that the predetermined values for the motor torque (driving force) and rotation speed of the odd-numbered stage motor generator 23 are zero, but these predetermined values are not limited to zero and may be values approximating zero.

Note that while the example in Figure 4 shows a case where the gear is switched to third gear, similar control is performed when switching from an odd-numbered gear to an even-numbered gear.

For example, we will explain the case where the vehicle temporarily passes through the EV3 series mode when transitioning from the EV2-EV3 mode in the EV mode to the HEV2-EV3-EV2 mode in the HEV mode or the HEV4-EV3-EV4 mode in the HEV mode.

In EV2-EV3 mode, the first dog clutch 52 is switched to the neutral position, the second dog clutch 53 is switched to a position that establishes third gear, and the third dog clutch 54 is switched to a position that establishes second gear.

In EV2-EV3 mode, when the motor torque of the odd-numbered motor-generator 23 and the even-numbered motor-generator 24 increases, the HCU 10 initiates a transition to the EV3 series.

The HCU 10 reduces the motor torque of the even-numbered stage motor-generators 24 toward zero and increases the motor torque of the odd-numbered stage motor-generators 23 using the odd-numbered stage inverter 14, compensating for the decrease in motor torque of the even-numbered stage motor-generators 24. In other words, the motor torque of the odd-numbered stage motor-generators 23 is increased by the amount of the decrease in motor torque of the even-numbered stage motor-generators 24.

After this, the vehicle 1 will be driven by the odd-numbered motor-generator 23 until the engine 2 switches to HEV mode.

When the motor torque of the even-numbered stage motor-generator 24 becomes zero, the HCU 10 controls the TCU 12 to switch the third dog clutch 54 to the neutral position, and controls the motor torque of the even-numbered stage motor-generator 24 using the even-numbered stage inverter 15 so that the rotation speed of the even-numbered stage motor-generator 24 becomes zero.

When the rotation speed of the even-numbered motor-generator 24 reaches zero, the HCU 10 controls the TCU 12 to switch the first dog clutch 52 from the neutral position to the even-numbered position, and then engages the friction clutch 33 to mechanically connect the crankshaft 2S and the input shaft 41.

At this time, driving force is transmitted from the even-numbered motor generator 24 to the input shaft 41 via the even-numbered motor drive gear 51A, the even-numbered motor driven gear 51B, and the even-numbered intermediate shaft 43. As a result, the motor torque of the even-numbered motor generator 24 is transmitted from the input shaft 41 to the crankshaft 2S via the friction clutch 33, and the engine 2 is started.

After engine 2 has started, the driving force of engine 2 is transmitted to the even-numbered motor-generator 24 via the input shaft 41, even-numbered intermediate shaft 43, even-numbered motor driven gear 51B, and even-numbered motor drive gear 51A, and the even-numbered motor-generator 24 begins generating electricity.

Next, to transition to HEV2-EV3-EV2 mode, the HCU 10 controls the engine torque and the motor torque of the even-numbered motor generator 24 so that the rotation speed of the output shaft 44 and the rotation speed of the second-speed output gear 46B match, thereby performing synchronization control of the output shaft 44 and the second-speed output gear 46B.

When the rotation speed of the output shaft 44 and the rotation speed of the second-speed output gear 46B match, the HCU 10 controls the TCU 12 to switch the third dog clutch 54 from the neutral position to a position that establishes second gear.

Then, in order to switch vehicle 1 from running using odd-numbered stage motor generator 23 to running vehicle 1 using engine 2, HCU 10 controls odd-numbered stage inverter 14 to reduce the motor torque of odd-numbered stage motor generator 23 and increase engine torque to match the driver-requested torque, completing the switch from EV mode to HEV mode.

Next, the running mode transition control will be described with reference to the timing chart of FIG.
The timing chart of FIG. 5 shows an example in which, when the driving mode is shifted from the EV mode to the HEV mode, the engine 2 is started by the even-numbered stage motor generator 24 and, after the engine 2 has started, the engine 2 is driven by the odd-numbered stage.

When traveling in EV mode, the friction clutch 33 is disengaged, and the crankshaft 2S and input shaft 41 are mechanically separated.

At time t0 in Figure 5, the vehicle 1 is stopped in D range. At this time, the first dog clutch 52 is in the neutral position, the second dog clutch 53 is switched to first gear, and the third dog clutch 54 is switched to second gear, and the driving mode is EV1-EV2 mode.

When the driver depresses the accelerator pedal 60 at time t1, the HCU 10 issues a command to the ECU 11, causing the odd-numbered stage inverter 14 and the even-numbered stage inverter 15 to generate motor torque from the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24. This causes the vehicle 1 to begin accelerating.

When the motor torque of the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 increases, the HCU 10 starts the transition from HEV1 to EV1 to EV2 at time t2.

At time t2, the HCU 10 reduces the motor torque of the even-numbered stage motor-generators 24 toward zero and increases the motor torque of the odd-numbered stage motor-generators 23 using the odd-numbered stage inverter 14, compensating for the decrease in motor torque of the even-numbered stage motor-generators 24. In other words, the motor torque of the odd-numbered stage motor-generators 23 is increased by the amount of the decrease in motor torque of the even-numbered stage motor-generators 24.

After this, the vehicle 1 will be driven by the odd-numbered motor-generator 23 until the engine 2 switches to HEV mode.

When the motor torque of the even-numbered stage motor-generator 24 becomes zero (time t3), the HCU 10 controls the TCU 12 to switch the third dog clutch 54 to the neutral position, and then controls the motor torque of the even-numbered stage motor-generator 24 using the even-numbered stage inverter 15 so that the rotation speed of the even-numbered stage motor-generator 24 becomes zero.

In other words, the HCU 10 reduces the rotation speed of the even-numbered stage intermediate shaft 43. In the example of FIG. 5, the HCU 10 applies back torque to the even-numbered stage motor-generator 24 to reduce the rotation speed of the even-numbered stage motor-generator 24.

When the rotation speed of the even-numbered stage motor-generator 24 reaches zero (time t4), the HCU 10 controls the TCU 12 to switch the first dog clutch 52 from the neutral position to the even-numbered stage position, and then engages the friction clutch 33 to mechanically connect the crankshaft 2S and the input shaft 41.

At this time, driving force is transmitted from the even-numbered motor generator 24 to the input shaft 41 via the even-numbered motor drive gear 51A, the even-numbered motor driven gear 51B, and the even-numbered intermediate shaft 43. As a result, the motor torque of the even-numbered motor generator 24 is transmitted from the input shaft 41 to the crankshaft 2S via the friction clutch 33, and the engine 2 is started.

Next, when the motor torque of the even-numbered stage motor-generator 24 becomes zero (time t6), the HCU 10 controls the TCU 12 to switch the first dog clutch 52 from the even-numbered stage position to the neutral position, and then controls the engine torque so that the rotation speed of the input shaft 41 and the rotation speed of the odd-numbered stage intermediate shaft 42 match, thereby performing synchronization control of the input shaft 41 and the odd-numbered stage intermediate shaft 42.

In the example shown in Figure 5, the HCU 10 controls the ECU 11 to increase the engine torque so as to increase the rotation speed of the engine 2 in a short period of time, and then decreases the engine torque as the rotation speed of the input shaft 41 and the rotation speed of the odd-stage intermediate shaft 42 are synchronized.

The rotation speed of the input shaft 41 is detected based on detection information from the input shaft rotation speed sensor 61 (see Figure 1), which detects the rotation speed of the input shaft 41.

The rotation speed of the odd-numbered stage intermediate shaft 42 can be calculated from the rotation speed of the odd-numbered stage motor generator 23. Specifically, the driving force of the odd-numbered stage motor generator 23 is reduced by the odd-numbered stage motor drive gear 50A and the odd-numbered stage motor driven gear 50B and then transmitted to the odd-numbered stage intermediate shaft 42.

As a result, the rotation speed of the odd-numbered stage intermediate shaft 42 can be calculated from the rotation speed of the odd-numbered stage motor generator 23 and the reduction ratio (gear ratio) of the odd-numbered stage motor drive gear 50A and the odd-numbered stage motor driven gear 50B.

Meanwhile, the HCU 10 controls the engine torque and simultaneously controls the motor torque of the even-numbered motor generator 24 so that the rotation speed of the output shaft 44 matches the rotation speed of the second-speed output gear 46B.

When the rotation speed of the output shaft 44 and the rotation speed of the second-speed output gear 46B match (t7), the HCU 10 controls the TCU 12 to switch the third dog clutch 54 from the neutral position to a position that establishes second gear.

Here, the rotation speed of the output shaft 44 is controlled by the motor torque of the odd-numbered motor-generator 23. And the rotation speed of the second-speed output gear 45B is controlled by the motor torque of the even-numbered motor-generator 24.

The HCU 10 calculates the rotation speed of the output shaft 44 from the rotation speed of the odd-numbered stage motor generator 23, the reduction ratio of the odd-numbered stage motor drive gear 50A and the odd-numbered stage motor driven gear 50B, and the gear ratio (gear ratio) of the first-speed gear pair 45 and the third-speed gear pair 47.

The HCU 10 also calculates the rotation speed of the second-speed output gear 46B based on the rotation speed of the even-speed motor generator 24, the reduction ratio of the even-speed motor drive gear 51A and the even-speed motor driven gear 51B, and the gear ratio (gear ratio) of the second-speed gear pair 46.

When the rotation speed of the input shaft 41 and the rotation speed of the odd-numbered stage intermediate shaft 42 match (t8), the HCU 10 switches the first dog clutch 52 to the odd-numbered stage position.

To switch vehicle 1 from running using even-numbered stage motor generator 24 to running vehicle 1 using engine 2, HCU 10 controls odd-numbered stage inverter 14 and even-numbered stage inverter 15 to reduce the motor torque of odd-numbered stage motor generator 23 and even-numbered stage motor generator 24, and increase engine torque to match the driver-requested torque. At time t9, the transition from EV mode to HEV mode is completed.

Next, the running mode transition control will be described with reference to the timing chart of FIG.
The timing chart of FIG. 6 shows an example of transitioning the driving mode from the EV mode to the EV1 series mode.

When traveling in EV mode, the friction clutch 33 is disengaged, and the crankshaft 2S and input shaft 41 are mechanically separated.

At time t0 in Figure 6, the vehicle 1 is stopped in D range. At this time, the first dog clutch 52 is in the neutral position, the second dog clutch 53 is switched to first gear, and the third dog clutch 54 is switched to second gear, and the driving mode is EV1-EV2 mode.

When the driver depresses the accelerator pedal 60 at time t1, the HCU 10 issues a command to the ECU 11, causing the odd-numbered stage inverter 14 and the even-numbered stage inverter 15 to generate motor torque from the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24. This causes the vehicle 1 to begin accelerating.

When the motor torque of the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24 increases, the HCU 10 begins transitioning to the EV1 series at time t2.

At time t2, the HCU 10 reduces the motor torque of the even-numbered stage motor-generators 24 toward zero and increases the motor torque of the odd-numbered stage motor-generators 23 using the odd-numbered stage inverter 14, compensating for the decrease in motor torque of the even-numbered stage motor-generators 24. In other words, the motor torque of the odd-numbered stage motor-generators 23 is increased by the amount of the decrease in motor torque of the even-numbered stage motor-generators 24.

After this, the vehicle 1 will be driven by the odd-numbered motor-generator 23 until the engine 2 switches to HEV mode.

When the motor torque of the even-numbered stage motor-generator 24 becomes zero (time t3), the HCU 10 controls the TCU 12 to switch the third dog clutch 54 to the neutral position, and then controls the motor torque of the even-numbered stage motor-generator 24 using the even-numbered stage inverter 15 so that the rotation speed of the even-numbered stage motor-generator 24 becomes zero.

In other words, the HCU 10 reduces the rotation speed of the even-numbered stage intermediate shaft 43. In the example of FIG. 6, the HCU 10 applies back torque to the even-numbered stage motor-generator 24 to reduce the rotation speed of the even-numbered stage motor-generator 24.

When the rotation speed of the even-numbered stage motor-generator 24 reaches zero (time t4), the HCU 10 controls the TCU 12 to switch the first dog clutch 52 from the neutral position to the even-numbered stage position, and then engages the friction clutch 33 to mechanically connect the crankshaft 2S and the input shaft 41.

At this time, driving force is transmitted from the even-numbered motor generator 24 to the input shaft 41 via the even-numbered motor drive gear 51A, the even-numbered motor driven gear 51B, and the even-numbered intermediate shaft 43. As a result, the motor torque of the even-numbered motor generator 24 is transmitted from the input shaft 41 to the crankshaft 2S via the friction clutch 33, and the engine 2 is started.

At time t5, starting of engine 2 is completed, and the driving force of engine 2 is transmitted to even-numbered motor generator 24 via input shaft 41, even-numbered intermediate shaft 43, even-numbered motor driven gear 51B, and even-numbered motor drive gear 51A, causing even-numbered motor generator 24 to start generating electricity. At time t6, the transition from EV mode to HEV mode (EV2 series mode) is completed.

As described above, the transmission 3 of the vehicle 1 in this embodiment comprises an input shaft 41 to which the driving force of the engine 2 is transmitted, an odd-numbered intermediate shaft 42 that is arranged coaxially with the input shaft 41 and rotatable relative to the input shaft 41, an even-numbered intermediate shaft 43 that is positioned outward of the input shaft 41, coaxially with the input shaft 41, and opposed to the odd-numbered intermediate shaft 42 in the axial direction of the input shaft, and rotatable relative to the input shaft 41, and an output shaft 44 that is arranged parallel to the odd-numbered intermediate shaft 42 and the even-numbered intermediate shaft 43 and transmits the driving force to the drive wheels 32L, 32R.

The transmission 3 also includes an odd-numbered stage motor-generator 23 connected to the odd-numbered stage intermediate shaft 42 so as to transmit driving force, and an even-numbered stage motor-generator 24 connected to the even-numbered stage intermediate shaft 43 so as to transmit driving force.

Furthermore, the transmission 3 is provided with a first gear pair 45 and a third gear pair 47 that connect the odd-numbered intermediate shaft 42 and the output shaft 44 so as to be able to transmit driving force and have different gear ratios, and a second gear pair 46 and a fourth gear pair 48 that connect the even-numbered intermediate shaft 43 and the output shaft 44 so as to be able to transmit driving force and have different gear ratios.

In addition, the control unit 30 of this embodiment switches the driving mode of the vehicle 1 between an EV mode in which the engine 2 is stopped and the vehicle 1 is driven by at least one of the odd-numbered stage motor-generators 23 and the even-numbered stage motor-generators 24, and an HEV mode in which the vehicle is driven by at least one of the odd-numbered stage motor-generators 23 and the even-numbered stage motor-generators 24 and the engine 2.

When the driving mode is shifted from EV mode to HEV mode, the control unit 30 starts the engine 2 using either the odd-numbered stage motor generator 23 or the even-numbered stage motor generator 24, and controls the motor torque and engine torque of either the odd-numbered stage motor generator 23 or the even-numbered stage motor generator 24 to drive the vehicle 1 using the driving force of the other odd-numbered stage motor generator 23 or the even-numbered stage motor generator 24 until the gear to which driving force is transmitted from the engine 2 is established.

Here, in the example of Figure 4, the gear to which driving force is transmitted from the engine 2 is established when, at time t7, the rotation speed of the output shaft 44 and the rotation speed of the third-speed output gear 47B match and the second dog clutch 53 is switched from the neutral position to a position that establishes third gear.

In the example of Figure 5, at time t8, the rotation speed of the input shaft 41 and the rotation speed of the odd-numbered stage intermediate shaft 42 match, and the first dog clutch 52 is switched to the odd-numbered stage position.

This allows the engine 2 to be started smoothly without using multiple clutches as in a dual-clutch system, and it also allows the transmission 3 to be made smaller and reduces the manufacturing costs of the transmission 3.

Furthermore, when transitioning from EV mode to HEV mode, the vehicle 1 is driven using one of the odd-numbered stage motor generators 23 and the even-numbered stage motor generators 24, and the engine 2 is started and the gear stage after the engine 2 is started can be established using the other of the odd-numbered stage motor generators 23 and the even-numbered stage motor generators 24.
Furthermore, when transitioning from EV mode to HEV mode, the vehicle 1 can be run using either the odd-numbered stage motor generator 23 or the even-numbered stage motor generator 24, and a gear shift can be established after starting the engine 2, and the engine 2 can be started using the other of the odd-numbered stage motor generator 23 and the even-numbered stage motor generator 24.

This prevents torque loss during mode transitions, preventing a decline in the acceleration performance of vehicle 1 and a decline in the drivability of vehicle 1.

In addition, the first-speed gear pair 45 and the third-speed gear pair 47 in this embodiment have a first-speed input gear 45A and a third-speed input gear 47A that are rotatable integrally with the odd-numbered intermediate shaft 42, and a first-speed output gear 45B and a third-speed output gear 47B that are rotatable relative to the output shaft 44 and mesh with the first-speed input gear 45A and the third-speed input gear 47A.

In addition, the second-speed gear pair 46 and the fourth-speed gear pair 48 in this embodiment have a second-speed input gear 46A and a fourth-speed input gear 48A that are rotatable integrally with the even-speed intermediate shaft 43, and a second-speed output gear 46B and a fourth-speed output gear 48B that are rotatable relative to the output shaft 44 and mesh with the second-speed input gear 46A and the fourth-speed input gear 48A, respectively.

The transmission 3 of this embodiment also includes a first dog clutch 52 that can be switched between a neutral position, an odd-numbered gear position that connects the input shaft 41 and the odd-numbered gear intermediate shaft 42, and an even-numbered gear position that connects the input shaft 41 and the even-numbered gear intermediate shaft 43.

The transmission 3 of this embodiment also has a second dog clutch 53 that connects the first-speed output gear 45B or the third-speed output gear 47B to the output shaft 44 and rotates integrally with the output shaft 44, thereby establishing odd-numbered gear stages.

In addition, the transmission 3 of this embodiment has a third dog clutch 54 that connects the second-speed output gear 46B or the fourth-speed output gear 48B to the output shaft 44 and rotates integrally with the output shaft 44, thereby establishing even-numbered gear stages.

In addition, when establishing odd-numbered gears during a transition from EV mode to HEV mode, the control unit 30 of this embodiment controls the second dog clutch 53 to switch to the neutral position when the motor torque of the odd-numbered gear motor-generator 23 becomes zero, and then controls the driving force of the odd-numbered gear motor-generator 23 so that the rotation speed of the odd-numbered gear intermediate shaft 42 becomes a predetermined value, thereby engaging the first dog clutch 52 with the odd-numbered gear intermediate shaft 42, thereby starting the engine 2 using the odd-numbered gear motor-generator 23.

In addition, when establishing the even gears during a transition from EV mode to HEV mode, the control unit 30 controls the third dog clutch 54 to switch to the neutral position when the driving force of the even gear motor-generator 24 reaches a predetermined value, and then controls the driving force of the even gear motor-generator 24 so that the rotation speed of the even gear intermediate shaft 43 reaches a predetermined value, thereby engaging the first dog clutch 52 with the even gear intermediate shaft 43, thereby starting the engine 2 using the even gear motor-generator 24.

As a result, by controlling the motor torque of the odd-numbered stage motor-generator 23 and the even-numbered stage motor-generator 24, the first dog clutch 52, the second dog clutch 53, and the third dog clutch 54 can be smoothly switched without using a synchronizing device such as a synchro mechanism.

In addition, the engine 2 can be started using the odd-numbered motor-generator 23 and even-numbered motor-generator 24 provided in the transmission 3, eliminating the need for a starter motor or other device to start the engine 2. This further reduces the number of parts in the transmission 3, further reducing the manufacturing cost of the transmission 3.

In addition, in this embodiment, when connecting the first-speed output gear 45B or the third-speed output gear 47B to the output shaft 44 using the second dog clutch 53 to establish an odd gear after the engine 2 is started, the control unit 30 controls the engine torque or the motor torque of the odd-speed motor-generator 23 to perform synchronization control to synchronize the rotational speed of the first-speed output gear 45B or the third-speed output gear 47B with the rotational speed of the output shaft 44, and once the rotational speed of the first-speed output gear 45B or the third-speed output gear 47B and the rotational speed of the output shaft 44 are synchronized, the first-speed output gear 45B or the third-speed output gear 47B is connected to the output shaft 44 using the second dog clutch 53.

In addition, when connecting the second-speed output gear 46B or fourth-speed output gear 48B to the output shaft 44 using the third dog clutch 54 to establish an even gear after the engine 2 has started, the control unit 30 controls the engine torque or the motor torque of the even-speed motor-generator 24 to perform synchronization control to synchronize the rotational speed of the second-speed output gear 46B or fourth-speed output gear 48B with the rotational speed of the output shaft 44, and once the rotational speed of the second-speed output gear 46B or fourth-speed output gear 48B and the rotational speed of the output shaft 44 are synchronized, the third dog clutch 54 connects the second-speed output gear 46B or fourth-speed output gear 48B to the output shaft 44.

This prevents the acceleration of vehicle 1 from being impaired and the drivability of vehicle 1 from being deteriorated.

In this embodiment, the control unit 30 controls the engine torque or the motor torque of the odd-numbered motor-generator 23, for example, to perform synchronization control to synchronize the rotation speed of the first-speed output gear 45B with the rotation speed of the output shaft 44. Once the rotation speed of the first-speed output gear 45B and the rotation speed of the output shaft 44 are synchronized, the second dog clutch 53 connects the first-speed output gear 45B to the output shaft 44, thereby preventing loss of acceleration of the vehicle 1 and preventing a deterioration in the drivability of the vehicle 1.

In addition, the transmission 3 of this embodiment has a first dog clutch 52, a second dog clutch 53, and a third dog clutch 54, eliminating the need for complex synchronizing devices such as synchro mechanisms, and allowing gear changes to be performed using the first dog clutch 52, the second dog clutch 53, and the third dog clutch 54, which have a simpler configuration than synchro mechanisms.

This allows the transmission 3 to be more effectively simplified and the manufacturing costs of the transmission 3 to be more effectively reduced.

Furthermore, the first dog clutch 52 can quickly and smoothly connect the rotation speed of the input shaft 41 and the odd-numbered intermediate shaft 42, for example, when the rotation speeds of the input shaft 41 and the odd-numbered intermediate shaft 42 are synchronized.

In addition, the first dog clutch 52, second dog clutch 53, and third dog clutch 54 have a simple configuration, which improves durability and allows for long-term use.

In the transmission 3 of this embodiment, the crankshaft 2S and input shaft 41 can be connected by a friction clutch 33, but a coupling consisting of a damper may be provided instead of the friction clutch 33. This damper constantly connects the crankshaft 2S and input shaft 41 so that driving force can be transmitted between them.

While embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be encompassed by the following claims.

1...Hybrid vehicle, 2...Engine (internal combustion engine), 3...Transmission, 10...HCU (control unit), 11...ECU (control unit), 12...TCU (control unit), 14...Odd-numbered stage inverter (control unit), 15...Even-numbered stage inverter (control unit), 23...Odd-numbered stage motor generator (odd-numbered stage rotating electric machine), 24...Even-numbered stage motor generator (even-numbered stage rotating electric machine), 30...Control unit, 41...Input shaft, 42...Odd-numbered stage intermediate shaft, 43...Even-numbered stage intermediate shaft, 44...Output shaft, 45...1st gear pair (odd-numbered stage gear pair), 45A...1st speed input gear (odd-numbered stage intermediate shaft side gear), 45B...1st speed output gear (odd-numbered stage Output shaft gear), 46...2nd gear pair (even-numbered gear pair), 46A...2nd gear input gear (even-numbered intermediate shaft gear), 46B...2nd gear output gear (even-numbered output shaft gear), 47...3rd gear pair (odd-numbered gear pair), 47A...3rd gear input gear (odd-numbered intermediate shaft gear), 47B...3rd gear output gear (odd-numbered output shaft gear), 48...4th gear pair (even-numbered gear pair), 48A...4th gear input gear (even-numbered intermediate shaft gear), 48B...4th gear output gear (even-numbered output shaft gear), 52...1st dog clutch (first switching member), 53...2nd dog clutch (second switching member), 54...3rd dog clutch (third switching member)

Claims (3)

A transmission is provided to change the speed of the driving force of the internal combustion engine and transmit it to the driving wheels.
The transmission is
an input shaft to which the driving force of the internal combustion engine is transmitted;
an odd-numbered stage intermediate shaft that is provided coaxially with the input shaft and is rotatable relative to the input shaft;
an even-numbered stage intermediate shaft located outside the input shaft, coaxial with the input shaft, and facing the odd-numbered stage intermediate shaft in the axial direction of the input shaft, the even-numbered stage intermediate shaft being rotatable relative to the input shaft;
an output shaft that is disposed in parallel with the odd-numbered stage intermediate shafts and the even-numbered stage intermediate shafts and transmits driving force to the driving wheels;
an odd-numbered stage rotating electric machine connected to the odd-numbered stage intermediate shaft so as to be able to transmit driving force;
an even-numbered stage rotating electric machine connected to the even-numbered stage intermediate shaft so as to be able to transmit driving force;
a plurality of odd-numbered gear pairs that connect the odd-numbered intermediate shaft and the output shaft so as to be able to transmit a driving force and that constitute odd-numbered gears having different gear ratios;
A control device for a hybrid vehicle including a plurality of even-numbered gear pairs that connect the even-numbered intermediate shaft and the output shaft so as to be able to transmit driving force and that configure even-numbered gears with different gear ratios,
the odd-numbered-stage gear pair includes a plurality of odd-numbered-stage intermediate shaft side gears provided so as to be integrally rotatable with the odd-numbered-stage intermediate shaft, and a plurality of odd-numbered-stage output shaft side gears provided so as to be relatively rotatable with the output shaft and meshing with the plurality of odd-numbered-stage intermediate shaft side gears, respectively;
the even-numbered gear pair includes a plurality of even-numbered intermediate shaft side gears provided so as to be integrally rotatable with the even-numbered intermediate shaft, and a plurality of even-numbered output shaft side gears provided so as to be relatively rotatable with the output shaft and meshing with the plurality of even-numbered intermediate shaft side gears, respectively;
The transmission is
a first switching member that is switchable between a neutral position, an odd-numbered stage position where the input shaft and the odd-numbered stage intermediate shaft are connected, and an even-numbered stage position where the input shaft and the even-numbered stage intermediate shaft are connected;
a second switching member that connects any one of the plurality of odd-numbered stage output shaft gears to the output shaft and rotates integrally with the output shaft to establish an odd-numbered stage; and
a third switching member that connects any one of the plurality of even-numbered stage output shaft side gears to the output shaft and rotates integrally with the output shaft to establish an even-numbered stage; and
a control unit that switches a driving mode of the vehicle between an EV mode in which the internal combustion engine is stopped and the vehicle is driven by at least one of the odd-numbered stage rotating electric machine and the even-numbered stage rotating electric machine, and an HEV mode in which the vehicle is driven by at least one of the odd-numbered stage rotating electric machine and the even-numbered stage rotating electric machine and the internal combustion engine,
The control unit
when the traveling mode is shifted from the EV mode to the HEV mode, the internal combustion engine is started by one of the odd-numbered stage rotating electric machine and the even-numbered stage rotating electric machine;
a driving force of one of the odd-numbered stage rotating electric machine and the even-numbered stage rotating electric machine and a driving force of the internal combustion engine are controlled to allow the vehicle to travel by the driving force of the other of the odd-numbered stage rotating electric machine and the even-numbered stage rotating electric machine until a gear stage to which driving force is transmitted from the internal combustion engine is established ;
When an odd-numbered stage is established during a transition from the EV mode to the HEV mode, when the driving force of the odd-numbered stage rotating electric machine reaches a predetermined value, the second switching member is controlled to be switched to a neutral position, and then the driving force of the odd-numbered stage rotating electric machine is controlled so that the rotation speed of the odd-numbered stage intermediate shaft reaches a predetermined value, thereby fitting the first switching member to the odd-numbered stage intermediate shaft, thereby starting the internal combustion engine with the odd-numbered stage rotating electric machine;
a control device for a hybrid vehicle, characterized in that, when an even-numbered gear is established during a transition from the EV mode to the HEV mode, the third switching member is controlled to be switched to a neutral position when the driving force of the even-numbered gear rotating electric machine reaches a predetermined value, and then the driving force of the even-numbered gear rotating electric machine is controlled so that the rotation speed of the even-numbered gear intermediate shaft reaches a predetermined value, thereby engaging the first switching member with the even-numbered gear intermediate shaft, thereby starting the internal combustion engine with the even-numbered gear rotating electric machine . The control unit
In order to establish an odd-numbered stage after the start of the internal combustion engine, when the odd-numbered stage output shaft side gear is connected to the output shaft by the second switching member, a synchronization control is performed in which the rotation speed of the odd-numbered stage output shaft side gear is synchronized with the rotation speed of the output shaft by controlling the driving force of the internal combustion engine or the driving force of the odd-numbered stage rotating electric machine, and when the rotation speed of the odd-numbered stage output shaft side gear and the rotation speed of the output shaft are synchronized, the odd-numbered stage output shaft side gear is connected to the output shaft by the second switching member,
2. The control device for a hybrid vehicle according to claim 1, wherein, in order to establish an even gear after starting the internal combustion engine, when the even-stage output shaft side gear is connected to the output shaft by the third switching member, synchronization control is performed to control the driving force of the internal combustion engine or the driving force of the even-stage rotating electric machine to synchronize the rotation speed of the even-stage output shaft side gear with the rotation speed of the output shaft, and when the rotation speed of the even-stage output shaft side gear and the rotation speed of the output shaft are synchronized, the even-stage output shaft side gear is connected to the output shaft by the third switching member . 3. The control device for a hybrid vehicle according to claim 1, wherein the first switching member, the second switching member, and the third switching member are configured as dog clutches .