阅读说明：本技术 混合动力车辆的驱动装置 (Drive device for hybrid vehicle ) 是由 笠原崇宏 于 2021-02-22 设计创作，主要内容包括：本发明提供一种混合动力车辆的驱动装置,其可将由在控制参数的指令值有大变动时执行降档引起的异常事态的产生防患于未然。控制部(4)输出降档指令以及各种控制参数的指令值,并判定相对于所述指令值的各种参数是否处于目标行动范围内,在各种参数处于目标行动范围内时,执行降档,在各种参数不处于目标行动范围内时,执行行动修正,并判定通过行动修正而各种参数是否恢复至目标行动范围内,在各种参数恢复至目标行动范围内时,执行降档,在未恢复至目标行动范围内时,以使行动修正后的各种参数包含于目标行动范围内的方式扩大所述目标行动范围来执行降档。(The invention provides a drive device for a hybrid vehicle, which can prevent the occurrence of abnormal situations caused by executing downshift when the command value of a control parameter has large variation. A control unit (4) outputs a downshift command and command values of various control parameters, determines whether or not various parameters corresponding to the command values are within a target action range, executes the downshift when the various parameters are within the target action range, executes action correction when the various parameters are not within the target action range, determines whether or not the various parameters are restored within the target action range by the action correction, executes the downshift when the various parameters are restored within the target action range, and executes the downshift so as to expand the target action range so that the various parameters after the action correction are included within the target action range when the various parameters are not restored within the target action range.)

1. A drive device of a hybrid vehicle, comprising: an engine; a first motor generator driven by the engine; a power split mechanism for splitting and transmitting power of the engine to the first motor generator and a rotating body; a transmission mechanism including a first engagement mechanism and a second engagement mechanism that can be selectively engaged and released, the transmission mechanism selectively shifting rotation of the rotating body to output power from a transmission output shaft; a power transmission path that transmits power output from the transmission output shaft to an axle; a second motor generator having a motor output shaft connected to the power transmission path; a one-way clutch interposed between the transmission output shaft and the motor output shaft, allowing relative rotation in one direction of the motor output shaft and prohibiting relative rotation in the other direction with respect to the transmission output shaft; and a control unit that controls the transmission mechanism; and the drive device of the hybrid vehicle is characterized in that,

the control unit outputs a downshift command and command values of various control parameters, determines whether or not the various parameters with respect to the command values are within a target action range, executes downshift when the various parameters are within the target action range, and executes first action correction when the various parameters are not within the target action range, and also executes the first action correction

Whether or not the various parameters are restored within the target action range by the first action correction is determined, and when the various parameters are restored within the target action range, a downshift is performed, and when the various parameters are not restored within the target action range, a second action correction is performed, and the target action range is expanded so that the various parameters after the second action correction are included within the target action range, and the downshift is performed.

2. The drive device of a hybrid vehicle according to claim 1, characterized in that the first behavior modification is performed by controlling the drive force of the transmission output shaft by rotational speed control of the first motor generator,

the controller determines whether or not the driving force of the transmission output shaft is within a target driving force range, executes downshift when the driving force is within the target driving force range, and lowers the target driving force by the second action correction when the driving force is not within the target driving force range.

3. The drive device of the hybrid vehicle according to claim 1 or 2, characterized in that the first behavior modification performs behavior modification based on the second motor generator in addition to rotation speed control based on the first motor generator.

4. The drive device of a hybrid vehicle according to claim 3, characterized in that the output restriction of the battery is released when the behavior modification by the second motor generator is executed.

5. The drive apparatus of a hybrid vehicle according to any one of claims 2 to 4, characterized in that, when a downshift is performed by reducing a target drive force by the second action correction, a command value of a control parameter output at the time of the next downshift is corrected.

Technical Field

The present invention relates to a drive device for a hybrid vehicle including one engine (engine) and two motor generators (motor generators).

Background

As a drive device of a hybrid vehicle, there is known a device including: a power distribution mechanism that distributes power output from an engine as a main drive source to the first motor generator and the transmission member; a second motor generator connected to the transmission member; and a transmission mechanism provided between the transmission member and the drive wheel (see, for example, patent document 1).

In the drive device, it is provided that: the transmission mechanism has a pair of friction engagement mechanisms such as a brake mechanism and a clutch mechanism, and is switched to a high speed stage or a low speed stage by switching engagement and release of one of the friction engagement mechanisms.

However, for example, when a downshift (downshifting) is performed to switch the transmission mechanism from a high gear to a low gear, a command value of a control parameter such as engine torque is output, and based on the command value, the control is performed so that the parameter such as engine speed becomes a target value.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open No. 2012-240551

[ patent document 2] International publication No. 2019/159604

Disclosure of Invention

[ problems to be solved by the invention ]

However, if the downshift is performed in a state where the command value of the control parameter is greatly deviated from the predetermined value due to the influence of external disturbance or the like, there is a possibility that, for example, the engine speed abnormally increases. In particular, when the inter-gear ratio (difference in gear ratio between gear positions) of the clutch mechanism included in the transmission mechanism is wide, such a problem occurs remarkably.

Therefore, an object of the present invention is to provide a drive device for a hybrid vehicle, which can prevent occurrence of an abnormal situation caused by execution of a downshift when a command value of a control parameter greatly fluctuates due to an external disturbance or the like.

[ means for solving problems ]

To achieve the above object, the present invention provides a drive device 100 for a hybrid vehicle, including: an engine 1; a first motor generator 2 driven by the engine 1; a power split mechanism 10 for splitting and transmitting the power of the engine 1 to the first motor generator 2 and the rotary body 14; a transmission mechanism 70 including a first engagement mechanism 30 and a second engagement mechanism 40 that can be selectively engaged and released, for selectively shifting the rotation of the rotary body 14 to output power from a transmission output shaft 27; a power transmission path 71 for transmitting the power output from the transmission output shaft 27 to the axle 57; a second motor generator 3 having a motor output shaft 3a connected to the power transmission path 71; a one-way clutch (50) interposed between the transmission output shaft 27 and the motor output shaft 3a, and permitting relative rotation in one direction of the motor output shaft 3a and inhibiting relative rotation in the other direction with respect to the transmission output shaft 27; and a control unit 4 for controlling the transmission mechanism 70; the control unit 4 outputs a downshift command and command values of various control parameters, determines whether or not the various parameters with respect to the command values are within a target action range, executes a downshift when the various parameters are within the target action range, executes a first action correction when the various parameters are not within the target action range, determines whether or not the various parameters are returned within the target action range by the first action correction, executes a downshift when the various parameters are returned within the target action range, executes a second action correction when the various parameters are not returned within the target action range, and executes a downshift by expanding the target action range so that the various parameters after the second action correction are included within the target action range.

According to the present invention, when various parameters deviate from a target action range due to a large variation in command values of control parameters output from a control unit at the time of downshift, a first action correction is executed, and when various parameters are not included in the target action range by the first action correction, the first action correction is performed by: the downshift is executed by expanding the target action range so that various parameters corrected by the second action correction are included in the target action range, and therefore occurrence of an abnormal situation after the downshift is executed can be prevented.

Here, it is also possible to: the first action correction is performed by controlling the driving force of the transmission output shaft 27 by the rotation speed control of the first motor/generator 2, and the controller 4 determines whether or not the driving force of the transmission output shaft 27 is within a target driving force range, performs a downshift when the driving force is within the target driving force range, and reduces the target driving force by the second action correction when the driving force is not within the target driving force range.

Further, it is also possible to: the first behavior correction is performed by the second motor generator 3 in addition to the rotation speed control by the first motor generator 2.

Further, it is also possible to provide: when the action correction by the second motor generator 3 is executed, the output restriction of the battery 6 is released.

Further, it is also possible to: when a downshift is performed by reducing the target driving force by the second action correction, the command value of the control parameter output at the next downshift is corrected.

[ Effect of the invention ]

According to the present invention, the following effects can be obtained: it is possible to prevent the occurrence of an abnormal situation caused by executing a downshift when there is a large variation in the command value of the control parameter due to an external disturbance or the like.

Drawings

Fig. 1 is a skeleton diagram showing a basic configuration of a drive device for a hybrid vehicle according to the present invention.

Fig. 2 is a block diagram showing a connection state of main parts constituting a drive device of a hybrid vehicle of the present invention.

Fig. 3 is a diagram showing the operating states of the brake mechanism, the clutch mechanism, the one-way clutch, and the engine in the traveling mode of the vehicle that can be realized by the drive device for a hybrid vehicle according to the present invention.

Fig. 4 is a skeleton diagram showing a torque transmission path in the HV low mode of the drive device of the hybrid vehicle according to the present invention.

Fig. 5 is a skeleton diagram showing a torque transmission path in the HV high mode of the drive device of the hybrid vehicle according to the present invention.

Fig. 6 (a) is a collinear chart showing an example of operation in the HV high mode, and fig. 6 (b) is a collinear chart showing an example of operation in the HV low mode.

Fig. 7 is a diagram showing a shift map of the HV low mode and the HV high mode.

Fig. 8 is a timing chart showing command values of various control parameters and temporal changes of various parameters at the time of downshift.

Fig. 9 is a flowchart showing a processing routine before executing the downshift.

Fig. 10 is a timing chart showing command values of various control parameters and temporal changes of the various control parameters when the first behavior correction is executed.

Fig. 11 is a timing chart showing command values of various control parameters and temporal changes of the various control parameters when the second action correction is executed.

Fig. 12 is a skeleton diagram showing another embodiment of the drive device for a hybrid vehicle according to the present invention.

[ description of symbols ]

1: engine (ENG)

2: first motor generator (MG1)

3: second motor generator (MG2)

3 a: rotating shaft of second motor generator (motor output shaft)

4: controller (control part)

5: power control unit

6: battery with a battery cell

8: hydraulic control device

10: first planetary gear mechanism (Power distribution mechanism)

11: first sun gear

12: first inner gear ring

13: first pinion gear

14: first planet carrier (rotating body)

20: second planetary gear mechanism

21: second sun gear (rotating element)

22: second inner gear ring (rotating element)

23: second pinion gear

24: second planet carrier

27: output shaft

30: brake mechanism (first engagement mechanism)

36: vehicle speed sensor (vehicle speed detecting component)

40: clutch mechanism (second jointing mechanism)

50: one-way clutch (OWY)

57: axle shaft

70: speed change mechanism

71: power transmission path

100: drive device

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[ basic Structure of drive device for hybrid vehicle ]

Fig. 1 is a skeleton diagram showing a basic configuration of a drive device of a hybrid vehicle according to the present embodiment, the hybrid vehicle according to the present embodiment is a front-wheel drive (FF) vehicle with a front engine, and a drive device 100 includes two motor generators, i.e., one Engine (ENG)1, a first motor generator (MG1)2, and a second motor generator (MG2)3, as drive sources, a first planetary gear mechanism 10 for power distribution, and a second planetary gear mechanism 20 for gear change.

The engine 1 converts thermal energy generated by combustion of an air-fuel mixture in which intake air measured by a throttle valve (throttle valve) and fuel injected from an injector are mixed at an appropriate ratio into kinetic energy, and the rotational power of the engine 1 is output to an output shaft 1a arranged along an axis line CL1 to rotationally drive the output shaft 1a at a predetermined speed. The opening degree of a throttle valve (throttle) in the engine 1, the fuel injection amount (injection timing and injection timing) by an injector, the ignition timing, and the like are controlled by a controller (ECU)4 constituting a control unit.

The first motor generator 2 and the second motor generator 3 are disposed at positions separated by a predetermined distance in the axial direction on the same axis, and these are housed in a case 7. Here, each of the first motor generator 2 and the second motor generator 3 includes a rotor rotatable about the axis line CL1 of the output shaft 1a of the engine 1 and a cylindrical stator fixed to the periphery of each rotor, and functions as a motor or a generator.

That is, when electric power is supplied from the Battery (BAT)6 to the coils of the stators via the Power Control Unit (PCU)5, the rotating shafts 2a and 3a of the rotors are rotationally driven, and therefore the first motor generator 2 and the second motor generator 3 function as motors (motors).

On the other hand, when the rotary shafts 2a and 3a of the first motor generator 2 and the second motor generator 3 are respectively rotationally driven by external force, the rotors rotate and the first motor generator 2 and the second motor generator 3 function as generators (generators), and electric power generated by the first motor generator 2 and the second motor generator 3 is stored in the battery 6 via the electric power control unit 5. During normal running of the hybrid vehicle, for example, during low-speed running or acceleration running, the first motor generator 2 mainly functions as a generator (generator), and the second motor generator 3 mainly functions as a motor (motor). The power control unit 5 includes an inverter (inverter), not shown, and controls the output torque or the regenerative torque of the first motor generator 2 and the second motor generator 3, respectively, by the inverter being controlled by a command from the controller 4.

Further, in the axial space between the first motor generator 2 and the second motor generator 3 in the housing 7, the first planetary gear mechanism 10 and the second planetary gear mechanism 20 are arranged in an axially aligned state. Specifically, the first planetary gear mechanism 10 is disposed on the first motor generator 2 side, and the second planetary gear mechanism 20 is disposed on the second motor generator 3 side.

Here, the first planetary gear mechanism 10 includes: a first sun gear (sun gear)11 rotatable about an axis line CL1, a first ring gear (ring gear)12 rotatably disposed around the first sun gear 11, a plurality of (only one shown in fig. 1) first pinion gears (planetary gears) 13 meshing with the first sun gear 11 and the first ring gear 12 and rotatable about the first sun gear 11 while rotating on its own axis, and a first carrier (carrier)14 rotatably supporting the first pinion gears 13.

In addition, the second planetary gear mechanism 20 also includes, similarly to the first planetary gear mechanism 10: a second sun gear 21 rotatable about an axis line CL1, a second ring gear 22 rotatably disposed around the second sun gear 21, a plurality of (only one in fig. 1) second pinion gears (planetary gears) 23 meshed with the second sun gear 21 and the second ring gear 22 and capable of revolving around the second sun gear 21 while rotating on its own axis, and a second carrier 24 rotatably supporting the second pinion gears 23.

However, the output shaft 1a of the engine 1 is coupled to the first carrier 14 of the first planetary gear mechanism 10, and the driving force of the engine 1 is input from the output shaft 1a to the first planetary gear mechanism 10 via the first carrier 14. Further, at the start of the engine 1, the driving force of the first motor generator 2 is input to the engine 1 via the first planetary gear mechanism 10, thereby starting (cranking) the engine 1.

The first carrier 14 of the first planetary gear mechanism 10 is coupled to a one-way clutch 15 provided on the inner circumferential surface of the circumferential wall of the housing 7. Here, the one-way clutch 15 functions as follows: the rotation of the first carrier 14 in the forward direction (the rotation direction of the output shaft 1a of the engine 1) is permitted, and the rotation of the first carrier 14 in the reverse direction is prohibited. By providing the one-way clutch 15, reverse torque is not applied to the engine 1 via the first carrier 14, and reverse rotation of the engine 1 can be prevented.

The first sun gear 11 of the first planetary gear mechanism 10 is coupled to the rotating shaft 2a of the rotor of the first motor/generator 2, and the first sun gear 11 rotates integrally with the rotor of the first motor/generator 2. The first ring gear 12 of the first planetary gear mechanism 10 is coupled to the second carrier 24 of the second planetary gear mechanism 20, and the first ring gear 12 and the second carrier 24 rotate integrally. Therefore, the first planetary gear mechanism 10 can output the driving force input from the engine 1 via the first carrier 14 to the first motor generator 2 via the first sun gear 11 and to the second carrier 24 via the first ring gear 12. That is, the first planetary gear mechanism 10 can distribute the driving force from the engine 1 and output the distributed driving force to the first motor generator 2 and the second planetary gear mechanism 20.

However, a cylindrical outer drum 25 centered on the axis CL1 is provided radially outward of the second ring gear 22 of the second planetary gear mechanism 20, and the second ring gear 22 of the second planetary gear mechanism 20 is coupled to the outer drum 25. Therefore, the second ring gear 22 rotates integrally with the outer drum 25.

Further, a brake mechanism (BR)30 is provided radially outside the outer drum 25. The brake mechanism 30 is configured as a wet multi-plate brake, and is configured by alternately arranging a plurality of annular plate-shaped brake plates (only one is shown in fig. 1) 31 and a plurality of identical annular plate-shaped disc plates (only one is shown in fig. 1) 32 in the axial direction. Here, the outer peripheral end of each stopper plate 31 is engaged with the inner peripheral surface of the peripheral wall of the housing 7 so as to be movable in the axial direction. The inner peripheral end of each disk plate 32 is joined to the outer peripheral surface of the outer drum 25 so as to be movable in the axial direction, and rotates integrally with the outer drum 25. A noncontact rotation speed sensor 35 that detects the rotation speed of the outer drum 25 is provided near the brake mechanism 30 on the inner circumferential surface of the circumferential wall of the housing 7.

A return spring (not shown) that biases the brake plate 31 in a direction to separate the disc plate 32 (brake release (OFF) direction) is provided in the brake mechanism 30; and a piston (not shown) that presses the brake plate 31 and the disc plate 32 in a direction (brake engagement (ON) direction) in which they are engaged with each other against the urging force of the return spring. Here, the piston is driven by the pressure (oil pressure) of oil supplied via the oil pressure control device 8.

In the brake mechanism 30, the brake plate 31 and the disc plate 32 are separated from each other in a state where the oil pressure does not act on the piston, and the brake mechanism 30 is in a released state (brake OFF state) in which the rotation of the second ring gear 22 is permitted.

ON the other hand, when the oil pressure acts ON the piston, the brake plate 31 and the disc plate 32 are engaged with each other, and the brake mechanism 30 is in an engaged state (brake ON state) in which the rotation of the second ring gear 22 is prevented.

Further, a cylindrical inner drum 26 centered on the axis CL1 is provided radially inward of the outer drum 25 so as to face the outer drum 25. Here, the second sun gear 21 of the second planetary gear mechanism 20 is coupled to the output shaft 27 of the second planetary gear mechanism 20 extending along the axis CL1 and is coupled to the inner drum 26, and therefore, the second sun gear 21, the output shaft 27, and the inner drum 26 rotate integrally. Further, a clutch mechanism (CL)40 is provided between the outer drum 25 and the inner drum 26.

The clutch mechanism 40 is configured as a wet multiple plate clutch, and is configured by alternately arranging a plurality of annular plate-shaped clutch plates (only one is shown in fig. 1) 41 and a plurality of identical annular plate-shaped disc plates (only one is shown in fig. 1) 42 in the axial direction. Here, the outer peripheral end of each clutch plate 41 is engaged with the inner peripheral surface of the outer drum 25 so as to be movable in the axial direction, and rotates integrally with the outer drum 25. Further, the inner peripheral end of each disc 42 is joined to the outer peripheral surface of the inner drum 26 so as to be movable in the axial direction, and rotates integrally with the inner drum 26.

A return spring (not shown) that biases the clutch plate 41 and the disc plate 42 in a direction of separating them (clutch OFF direction) is provided in the clutch mechanism 40; and a piston (not shown) that presses the clutch plate 41 and the disc plate 42 in a direction (clutch ON direction) to engage with each other against the biasing force of the return spring. Here, the piston is driven by the pressure (oil pressure) of oil supplied via the oil pressure control device 8.

In the clutch mechanism 40, the clutch plates 41 and the disc plates 42 are separated from each other in a state where the hydraulic pressure does not act on the piston, and the clutch mechanism 40 is in a released state (clutch OFF state) in which the relative rotation of the second sun gear 21 with respect to the second ring gear 22 is enabled. At this time, when the brake mechanism 30 is in the engaged state (brake ON state) to stop the rotation of the second ring gear 22, the rotation of the output shaft 27 relative to the second carrier 24 is increased. The state corresponds to a state in which the shift speed is switched to the high speed (high).

ON the other hand, when hydraulic pressure acts ON the piston, the clutch plate 41 and the disc plate 42 are engaged with each other, and the clutch mechanism 40 is brought into an engaged state (clutch ON state) in which the second sun gear 21 and the second ring gear 22 are integrally coupled. At this time, when the brake mechanism 30 is in the released state (brake OFF state) and rotation of the second ring gear 22 is permitted, the output shaft 27 is integrated with the second carrier 24 and rotates at the same speed as the second carrier 24. The state corresponds to a state in which the shift speed is switched to a low speed (low).

Here, the second planetary gear mechanism 20, the brake mechanism 30, and the clutch mechanism 40 constitute a speed change mechanism that changes the rotation of the second carrier 24 to two stages of low and high and outputs the changed rotation from the output shaft 27.

Further, a one-way clutch (OWY)50 is interposed between the output shaft 27 and the rotary shaft 3a of the second motor generator 3, and the output shaft 27 is coupled to an output gear 51 centered on the axis CL1 via the one-way clutch 50. Here, the one-way clutch 50 permits rotation of the output gear 51 in the forward direction with respect to the output shaft 27, that is, relative rotation corresponding to the forward direction of the vehicle, and prohibits relative rotation corresponding to the reverse direction. That is, when the rotation speed of the output shaft 27 corresponding to the vehicle forward direction is faster than the rotation speed of the output gear 51, the one-way clutch 50 is locked and the output shaft 27 rotates integrally with the output gear 51. On the other hand, when the rotational speed of the output gear 51 corresponding to the vehicle forward direction is faster than the rotational speed of the output shaft 27, the one-way clutch 50 is released (unlocked), and the output gear 51 is free to rotate relative to the output shaft 27 without introducing torque.

The rotary shaft 3a of the rotor of the second motor generator 3 is connected to the output gear 51, and the output gear 51 rotates integrally with the second motor generator 3 (rotary shaft 3 a). Here, since the one-way clutch 50 is interposed between the output shaft 27 and the rotary shaft 3a, relative rotation of the rotary shaft 3a in the positive direction with respect to the output shaft 27 is permitted. That is, when the rotation speed of the second motor generator 3 is faster than the rotation speed of the output shaft 27, the second motor generator 3 can be rotated efficiently without introducing the torque of the output shaft 27 (second planetary gear mechanism 20). Here, since the one-way clutch 50 is disposed radially inward of the rotary shaft 3a, the axial length of the drive device 100 can be suppressed, and the drive device 100 can be downsized.

However, an oil pump (MOP)60 is disposed radially inward of the second motor generator 3, and the oil pump 60 is coupled to the output shaft 1a of the engine 1 and rotationally driven by the engine 1. When oil supply is required while the engine 1 is stopped, the electric power is supplied from the battery 6 to drive the electric pump (EOP)61, and the required oil is supplied from the electric pump 61.

Further, a large-diameter gear 53 attached to the counter shaft 52 arranged in parallel with the axis line CL1 meshes with the output gear 51, and torque is transmitted to the counter shaft 52 via the large-diameter gear 53. Then, the torque transmitted to the counter shaft 52 is transmitted to the ring gear 56 of the differential device 55 via the small-diameter gear 54, distributed by the differential device 55, and transmitted to the left and right axles 57. Therefore, the vehicle travels by rotationally driving left and right front wheels (only one is shown in fig. 1) 101 attached to the left and right axles 57. Here, the rotary shaft 3a, the output gear 51, the large diameter gear 53, the small diameter gear 54, the differential gear 55, and the like constitute a power transmission path 71 from the output shaft 27 to the axle 57.

However, the hydraulic control device 8 includes control valves such as solenoid valves and electromagnetic proportional valves, not shown, which are operated by electric signals, and these control valves are operated by commands from the controller 4 to control the flow of hydraulic oil to the brake mechanism 30, the clutch mechanism 40, and the like. Thereby, ON/OFF of the brake mechanism 30 or the clutch mechanism 40 can be switched.

The controller (ECU)4 includes an arithmetic Processing device including a Central Processing Unit (CPU), a Read Only Memory (ROM), a Random Access Memory (RAM), other peripheral circuits, and the like, and includes an engine control ECU 4a, a transmission mechanism control ECU 4b, and a motor/generator control ECU 4 c.

Signals from a rotational speed sensor 35 that detects the rotational speed of the outer drum 25, a vehicle speed sensor 36 that detects the vehicle speed, an accelerator opening sensor 37 that detects the accelerator opening, a rotational speed sensor 38 that detects the rotational speed of the engine 1, and the like are input to the controller 4. Then, the controller 4 determines the running mode based on the input signal and a driving force map indicating driving force characteristics defined based on a predetermined vehicle speed, an accelerator opening degree, and the like. The controller 4 outputs control signals to the throttle opening adjustment actuator, the fuel injection injector, the electric power control unit 5, the hydraulic control device 8, and the like, and controls the operations of the engine 1, the first motor generator 2 and the second motor generator 3, and the brake mechanism 30 and the clutch mechanism 40 so that the vehicle travels in accordance with the traveling mode.

Here, fig. 2 shows a connection state of main parts constituting the driving device 100.

As shown in fig. 2, a first planetary gear mechanism 10 for power split is connected to an Engine (ENG)1, and a first motor generator (MG1)2 and a second planetary gear mechanism 20 for speed change are connected to the first planetary gear mechanism 10. A second motor generator (MG2)3 is connected to the second planetary gear mechanism 20 via a one-way clutch (OWY)50, and a front wheel 101 as a drive wheel is connected to the second motor generator (MG2) 3.

[ traveling mode of vehicle ]

Fig. 3 shows, in a table format, an example of the traveling mode of the vehicle that can be realized by drive device 100, and the operating states of brake mechanism (BR)30, clutch mechanism (CL)40, one-way clutch (OWY)50, and Engine (ENG)1 corresponding to the traveling mode.

Fig. 3 shows an EV mode, a W motor mode, a series mode, and an HV mode as representative traveling modes. Here, the HV modes are classified into a low mode (HV low mode) and a high mode (HV high mode). In fig. 3, ON (engagement) of brake mechanism (BR)30, ON (engagement) of clutch mechanism (CL)40, lock of one-way clutch (OWY)50, and operation of Engine (ENG)1 are indicated by o marks, and OFF (release) of brake mechanism (BR)30, OFF (release) of clutch mechanism (CL)40, unlock (release) of one-way clutch (OWY)50, and stop of Engine (ENG)1 are indicated by x marks, respectively.

Here, only the HV mode among the various traveling modes will be described.

The HV mode is a mode in which the vehicle travels by both the driving force of the engine 1 and the driving force of the second motor generator 3, and includes an HV low mode and an HV high mode. Here, the HV low mode is a mode corresponding to full-open acceleration running from low speed, and the HV high mode is a mode corresponding to normal driving after EV running.

(HV Low mode)

As shown in fig. 3, in the HV low mode, the brake mechanism 30 is released (OFF) and the clutch mechanism 40 is engaged (ON) according to a command from the controller 4, and in the HV high mode, conversely, the brake mechanism 30 is engaged (ON) and the clutch mechanism 40 is released (OFF), at which time the engine 1 is driven and the one-way clutch 50 is in a locked state (engaged state).

Here, the torque transmission path in the HV low mode is shown in the skeleton diagram of fig. 4.

As shown in fig. 4, in the HV low mode, a part of the torque output from the engine 1 is transmitted to the first motor generator 2 via the first sun gear 11, and the first motor generator 2 generates electric power. Then, the electric power generated by the first motor generator 2 is charged in the battery 6, and the driving electric power is supplied from the battery 6 to the second motor generator 3.

In the HV low mode, the remaining part of the torque output from the engine 1 is transmitted to the output shaft 27 via the first ring gear 12 and the second carrier (the second carrier that rotates integrally with the second sun gear 21 and the second ring gear 22) 24, and the rotational speed of the output shaft 27 at this time is equal to the rotational speed of the second carrier 24. The torque transmitted to the output shaft 27 is transmitted to the output gear 51 via the one-way clutch 50 in the locked state, and is transmitted from the output gear 51 to the left and right axles 57 via the counter shaft 52, the small-diameter gear 54, the ring gear 56, and the differential device 55, and the axles 57 and the front wheels 101 are rotationally driven to run the vehicle. Therefore, in the HV low mode, the vehicle can be run at a high torque by the torque from the engine 1 and the second motor generator 3 while maintaining a sufficient remaining amount (SOC) in the battery 6 by utilizing the power generation of the first motor generator 2.

(HV high mode)

Then, the torque transmission path in the HV high mode is shown in the skeleton diagram of fig. 5.

As shown in fig. 5, in the HV high mode, a part of the torque output from the engine 1 is transmitted to the first motor generator 2 via the first sun gear 11, as in the HV low mode. The remaining part of the torque output from the engine 1 is transmitted to the output shaft 27 via the first ring gear 12, the second carrier 24, and the second sun gear 21, and the rotation speed of the output shaft 27 at this time is greater than the rotation speed of the second carrier 24. That is, the rotation of the second carrier 24 is increased in speed and transmitted to the second sun gear 21 and the output shaft 27.

Then, the torque transmitted to the output shaft 27 is transmitted to the output gear 51 via the one-way clutch 50 in the locked state, and is transmitted from the output gear 51 to the left and right axles 57 via the counter shaft 52, the small-diameter gear 54, the ring gear 56, and the differential device 55 together with the torque output from the second motor generator 3, and the axles 57 and the front wheels 101 are rotationally driven to run the vehicle. Therefore, in the HV high mode, it is possible to keep a sufficient remaining amount (SOC) in the battery 6 and run the vehicle with a torque lower than the HV low mode but higher than the EV mode by the torques from the engine 1 and the second motor generator 3. Here, in the HV high mode, the speed is increased by the second planetary gear mechanism 20, and therefore the vehicle can be driven while suppressing the rotation speed of the engine 1 as compared with the HV low mode.

However, although the shift operation (downshift) from the HV high mode to the HV low mode and the opposite shift operation (upshift) from the HV low mode to the HV high mode are performed in accordance with a command from the controller 4, the drive device 100 of the present embodiment is characterized by the shift operation (downshift) from the HV high mode to the HV low mode, and therefore, the following description will be given.

[ control during downshift ]

Fig. 6 (a) and 6 (b) show examples of collinear diagrams of the HV high mode and the HV low mode, where the first sun gear 11, the first carrier 14, and the first ring gear 12 are indicated by "1S", "1C", and "1R", respectively, and the second sun gear 21, the second carrier 24, and the second ring gear 22 are indicated by "2S", "2C", and "2R", respectively. Further, the rotational direction of the first ring gear 12 and the second carrier 24 when the vehicle is moving forward is defined as a positive direction and is denoted by + and torque acting in the positive direction is denoted by an upward arrow.

As shown in fig. 6 (a), in the HV high mode, the hydraulic control device 8 controls the brake mechanism 30 and the clutch mechanism 40 in accordance with a command from the controller 4, whereby the brake mechanism (BR)30 is engaged (ON) and the clutch mechanism (CL)40 is released (OFF). In this state, the engine 1 rotates the first carrier (1C)14 in the forward direction, the first motor generator (MG1)2 is rotationally driven to generate electric power, and the first ring gear (1R)12 is rotated in the forward direction. At this time, since the rotation of the second ring gear (2R)22 is prevented by the brake mechanism (BR)30, the second sun gear (2S)21 rotates at a higher speed than the second carrier (2C) 24. Therefore, the vehicle runs by the rotational torque of the second sun gear (2S)21 and the torque of the second motor generator (MS2) 3.

When the required driving force increases as the vehicle speed increases, the controller 4 switches the running mode from, for example, the HV high mode to the HV low mode (downshift), but as shown in fig. 6 (b), in the HV low mode, the brake mechanism (BR)30 is released (OFF) and the clutch mechanism (CL)40 is engaged (ON) by the hydraulic control device 8 that is operated in accordance with a command from the controller 4. In this state, the engine 1 rotates the first carrier (1C)14 in the forward direction, the first motor generator (MG1)2 is rotationally driven to generate electric power, and the first ring gear (1R)12 is rotated in the forward direction. At this time, since the second carrier (2C)24, the second sun gear (2S)21, and the second ring gear (2R)22 are integrated, the second sun gear (2S)21 rotates at the same speed as the second carrier (2C)24, and the vehicle travels by the rotational torque of the second sun gear (2S)21 and the torque of the second motor generator (MS2) 3.

Here, although the shift maps of the HV low mode and the HV high mode are shown in fig. 7, the HV low mode and the HV high mode are set based on the vehicle speed detected by the vehicle speed sensor 36 (see fig. 1) and the accelerator opening (AP) detected by the accelerator opening sensor 37 (see fig. 1) as described below.

That is, in the vehicle speed region of 50km/h or less, the travel mode is set to the HV low mode in the region larger than the accelerator opening (AP) defined as 4/8, and the travel mode is set to the HV high mode in the region smaller than the accelerator opening. In addition, in the region where the vehicle speed exceeds 50km/h, the travel mode is set to the HV low mode in the region larger than the accelerator opening (AP) defined as 5/8, and the travel mode is set to the HV high mode in the region smaller than the accelerator opening. The shift map shown in fig. 7 is an example, and is not necessarily limited thereto.

Here, the time chart of fig. 8 shows the command value of the control parameter and the time change of various control parameters at the time of downshift, and this indicates a state where the command value of the control parameter is not affected by disturbance and downshift is normally performed. Further, as the control parameters, an engine torque, a torque of the first motor generator 2 (indicated as "MG 1 torque"), a brake torque (indicated as "BR torque"), and a clutch torque (indicated as "CL torque") are used. The rotational speed of the second sun gear 21 and the rotational speed of the second ring gear 22, the rotational speed of the engine 1 (indicated as "Ne rotational speed") and the rotational speed of the first motor generator 2 (indicated as "MG 1 rotational speed"), and the absolute G of the driving force (acceleration/deceleration) are used as various parameters.

When a downshift from the HV high mode to the HV low mode is performed, as shown in fig. 8, command values that change with time as shown in the drawing are output from the controller 4 with respect to the engine torque and the MG1 torque, and the BR torque and the CL torque. Specifically, the hydraulic pressure is rapidly removed from the brake mechanism 30 in the ON (engaged) state until time t1 to rapidly decrease the BR torque, and then the hydraulic pressure is slowly supplied to the brake mechanism 30 to gradually increase the BR torque. At this time, the CL torque is maintained at 0, and the engine torque is gradually decreased. Various parameters (second sun gear rotation speed, second ring gear rotation speed, engine rotation speed Ne, and MG1 rotation speed) are changed as shown in the drawing with respect to the command values of such control parameters (engine torque, MG1 torque, BR torque, and CL torque).

That is, the second ring gear 22 of the second planetary gear mechanism 20, which stops rotating in the HV high mode, starts rotating, and its rotation speed slowly increases. Then, when the rotation speed of the second ring gear 22 reaches the rotation speed of the second sun gear 21 (time t2), the hydraulic pressure starts to be supplied to the clutch mechanism 40, the CL torque is increased at a burst to turn ON (engage) the clutch mechanism 40, and the hydraulic pressure stops being supplied to the brake mechanism 30 to turn 0 the BR torque, thereby turning OFF (release) the brake mechanism 30. As a result, the downshift is completed at time t2, and the vehicle travels in the HV low mode. Then, until time t2 when the downshift is completed, the engine rotation speed Ne gradually increases, and the rotation speed of the first motor/generator 2 (MG1 rotation speed) rotates at a predetermined speed in the direction opposite to the engine 1.

Further, the feeling of deceleration (indicated as "driving force absolute G") felt by the occupant of the vehicle slightly varies around time t2 when the downshift is completed by switching ON/OFF of the brake mechanism 30 and the clutch mechanism 40.

However, although the above description has been given of the example in the case where the command values of the control parameters (the engine torque, the MG1 torque, the BR torque, and the CL torque) are normally output without being affected by external disturbances or the like, the present invention is characterized in that: the processing before the downshift is executed when the command values of these control parameters are greatly deviated from the desired values due to the influence of external disturbance or the like. The processing procedure is described below based on the flowchart shown in fig. 9.

When a downshift is performed and a downshift command is output from the controller 4 (step S1), the shift process is performed by map control, and command values of the engine torque, MG1 torque, BR torque, and CL torque are obtained as control parameters (step S2). Then, various control parameters (the rotation speed of the second sun gear 21, the rotation speed of the second ring gear 22, the engine rotation speed Ne, the MG1 rotation speed, and the like) are detected with respect to the command values of the control parameters thus obtained (step S3), and it is determined whether or not these are within the target action range (step S4). As a result of the determination, when various control parameters are within the target action range (YES at step S4), a downshift is performed in accordance with the intention (step S5).

On the other hand, when the various control parameters are not within the target action range (NO in step S4), the first action correction is executed (step S6). The first behavior correction is performed by controlling the driving force of the output shaft 27 by controlling the rotation speed of the first motor/generator 2. Then, it is determined whether or not the various control parameters can be recovered (recovery) within the target action range by the first action correction, specifically, whether or not the driving force of the output shaft 27 controlled by the rotation control of the first motor generator 2 is within the range of the target driving force (step S7).

Here, the drive torques T in the respective sections shown in fig. 8, that is, in the HV high mode section a, the inertia phase b, the inertia phase c, the torque phase d, and the HV low mode section e_COEach is calculated by the following formula. In the following formula, T_inFor input torque, T_mg2At MG2 torque, T_bAs brake torque, T_cFor the clutch to rotateMoment, i_LAt a low mechanical ratio, i_HAt a high mechanical ratio, i_mg2The ratio was MG 2. In addition, brake torque T_bAnd clutch torque T_cThe values are experimentally calculated in advance for the hydraulic pressure command.

1) HV high mode interval a:

T_CO＝T_in·i_H+C

2) an inertial phase b:

T_CO＝T_b·i_H+T_mg2·i_mg2

3) an inertial phase c:

T_CO＝T_b·i_H+T_mg2·i_mg2

4) torque phase d:

T_CO＝T_in·i_L+T_b·(i_L-i_H)

5) HV low mode interval e:

T_CO＝T_in·i_L+T_mg2·i_mg2

here, returning to fig. 9, if the various control parameters are included in the target action range (the various control parameters can be returned to normal values) by the second action correction (Yes in step S7), as a result of the determination in step S7, the action correction by the second motor generator 3 is added to the action correction by the first motor generator 2, the output limit of the battery 6 is released (step S8), and the downshift is executed (step S5). In this case, the second motor generator 3 is operated by the electric power supplied from the battery 6 to assist the driving of the first motor generator 2, and therefore, even when the remaining amount (SOC) of the battery 6 is reduced, the output limit of the battery 6 is released.

On the other hand, when the various control parameters are not included in the target action range (the various control parameters cannot be restored to normal values) by the first action correction (step S7: No), the second action correction is executed (step S9). In the second behavior modification, the target behavior range is expanded, specifically, the target driving force is reduced. That is, the target driving force is reduced so that the driving force of the output shaft 27 after the first motion correction is included in the range of the target driving force. In this case, the target engine torque and the target brake torque (BR torque) in the control parameters are set to values corrected since the next downshift. By doing so, the occurrence of an abnormal situation can be suppressed as much as possible since the next downshift.

Then, the process proceeds to step S8, the action correction by the second motor generator 3 is added to the action correction by the first motor generator 2, the output restriction of the battery 6 is released, and the downshift is performed (step S5).

Here, fig. 10 and 11 show, in a timing chart, command values of various control parameters and temporal changes of various control parameters when the first behavior modification is executed and when the second behavior modification is executed. In these figures, the values indicated by the dotted lines are values before the action correction is performed, and the values indicated by the solid lines are values after the action correction is performed. According to the first behavior correction, the driving force is reduced but the target value is maintained (see fig. 10), and in the second behavior correction, as shown in fig. 11, the reduction in the driving force is significant and the target value cannot be maintained.

As described above, in the present invention, it is assumed that: when various control parameters deviate from a target action range due to a large variation in command values of the control parameters output from the control unit at the time of downshift, the first action correction is executed, and when various control parameters are not included in the target action range by the first action correction, the downshift is executed by expanding the target action range so that various control parameters corrected by the second action correction are included in the target action range, so that occurrence of an abnormal situation after execution of the downshift can be prevented.

Fig. 12 shows another aspect of the hybrid vehicle according to the present invention.

That is, fig. 12 is a skeleton diagram showing the configuration of a drive device for a hybrid vehicle according to another embodiment of the present invention, and in this figure, the same elements as those shown in fig. 1 are denoted by the same reference numerals, and the re-description thereof will be omitted below.

In the drive device shown in fig. 12, a normally closed brake mechanism 80 is used instead of the brake mechanism 30 and the clutch mechanism 40 shown in fig. 1, and the present invention can be similarly applied to such a drive device.

The application of the present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible within the scope of the technical idea described in the claims, the description, and the drawings.