JP2021187347A - Four-wheel drive vehicle - Google Patents

Abstract

To provide a four-wheel drive vehicle which can appropriately improve energy efficiency when executing regenerative control through a rotary machine during the deceleration of the vehicle.SOLUTION: In a four-wheel drive state, regenerative control through a second rotary machine MG2 is executed so that demand braking force Bdem is partially or completely achieved during the deceleration of a four-wheel drive vehicle 10. In a case where an energy balance InEx is equal to or less than zero when the regenerative control through the second rotary machine MG2 is executed, the regenerative control is executed in a two-wheel drive state in a disconnection state instead of the four-wheel drive state. Thus, the regenerative control is not only executed in the four-wheel drive state, but also executed in the two-wheel drive state in consideration of energy loss in the four-wheel drive state. As a result, when the regenerative control through the second rotary machine MG2 is executed during the deceleration of the vehicle, energy efficiency can be appropriately improved.SELECTED DRAWING: Figure 7

Description

The present invention includes two clutches provided on the drive force source side and the auxiliary drive wheel side of a transmission member that transmits a part of the drive force from the drive force source to the auxiliary drive wheels during four-wheel drive travel. It is about a wheel drive vehicle.

The driving force source, the main driving wheel to which the driving force from the driving force source is transmitted, the sub-driving wheel to which a part of the driving force is distributed during the four-wheel drive driving, and the sub-driving wheel to which the driving force is distributed during the four-wheel drive driving. A transmission member that transmits a part of the driving force to the auxiliary drive wheel, a first clutch capable of connecting and disconnecting power transmission between the driving force source and the transmission member, and the transmission member and the auxiliary drive. A four-wheel drive vehicle including a second clutch capable of connecting and disconnecting power transmission to and from the wheels and a control device for controlling the first clutch and the second clutch is well known. For example, the standby four-wheel drive vehicle described in Patent Document 1 is that. In Patent Document 1, a regenerative brake is provided on the axle of the auxiliary drive wheel, and a transmission member that rotates due to inertia when both the first clutch and the second clutch are released when the vehicle is braked. When the actual rotation speed is larger than the value obtained by converting the rotation speed of the axle of the auxiliary drive wheel into the rotation speed equivalent to that of the transmission member, only the second clutch is engaged and the inertial energy of the transmission member is converted into electric energy. It is disclosed that it will be collected.

Japanese Unexamined Patent Publication No. 2012-228917

By the way, in the four-wheel drive vehicle as described above, in the case of an electric vehicle such as a hybrid vehicle or an electric vehicle having at least a rotating machine as a driving force source, the regeneration control by the rotating machine is executed at the time of vehicle deceleration, that is, The energy efficiency of a vehicle can be improved by converting the inertial energy of the vehicle into electrical energy and recovering it, but there is room for improvement in improving the energy efficiency. Specifically, in a four-wheel drive vehicle, when performing regenerative control so as to realize a part or all of the required braking force during vehicle deceleration, for example, wheels by regenerative control in consideration of suppression or avoidance of tire slip. Since the braking force of the tire is limited, the energy obtained by the regenerative control by the rotating machine is more likely to be larger in the four-wheel drive state than in the two-wheel drive state. However, in the four-wheel drive state, unlike the two-wheel drive state in which both the first clutch and the second clutch are disengaged, the transmission member is rotated, so that energy loss occurs. Such energy loss is caused by, for example, energy loss due to a stirring loss of the differential gear of the differential gear device on the auxiliary drive wheel side as a transmission member, and rotation of the propeller shaft on the auxiliary drive wheel side as a transmission member. Energy loss due to this. Therefore, there is room for improvement in improving energy efficiency by simply executing regenerative control by a rotating machine in a four-wheel drive state when the vehicle is decelerating.

The present invention has been made in the background of the above circumstances, and an object thereof is a four-wheel drive capable of appropriately improving energy efficiency when performing regenerative control by a rotating machine during vehicle deceleration. To provide a vehicle.

The gist of the first invention is (a) a driving force source including at least a rotating machine, a main driving wheel to which the driving force from the driving force source is transmitted, and the driving force during four-wheel drive traveling. An auxiliary drive wheel to which a part is distributed, a transmission member for transmitting a part of the driving force distributed during the four-wheel drive traveling to the auxiliary drive wheel, and a driving force source and the transmission member. A first clutch capable of connecting and disconnecting power transmission, a second clutch capable of connecting and disconnecting power transmission between the transmission member and the auxiliary drive wheel, the rotary machine, the first clutch, and the first. A four-wheel drive vehicle comprising a control device for controlling two clutches, (b) the control device engaging the four-wheel drive vehicle with the first clutch and the second clutch together. The four-wheel drive state is set, and both the first clutch and the second clutch are released to enter the two-wheel drive state in the disconnect state. (C) The control device is used when the four-wheel drive vehicle is decelerated. While the regenerative control by the rotary machine is executed in the four-wheel drive state so as to realize a part or all of the required braking force for the four-wheel drive vehicle, in the four-wheel drive state when the regenerative control is executed. The energy balance obtained by subtracting the energy loss amount due to the rotation of the transmission member in the four-wheel drive state from the energy acquisition amount due to the regeneration control, which is increased as compared with the two-wheel drive state in the disconnect state. When the value is equal to or less than zero and is equal to or less than a predetermined threshold value, the regeneration control is executed in the two-wheel drive state in the disconnect state instead of the four-wheel drive state.

The second invention is the four-wheel drive vehicle according to the first invention, in which the control device is in the disconnected state when the regenerative control is not executed when the four-wheel drive vehicle is decelerated. It is to be in a two-wheel drive state.

Further, the third invention is the four-wheel drive vehicle according to the first invention or the second invention, wherein the control device has a driving performance in which the operating state of the four-wheel drive vehicle is higher than the improvement of energy efficiency. When the vehicle is in a predetermined operating state in which improvement is emphasized, the threshold value is set to a smaller value than when the operating state of the four-wheel drive vehicle is not in the predetermined operating state.

Further, the fourth invention is the four-wheel drive vehicle according to the third invention, in which the predetermined driving state is a driving state in which the four-wheel drive vehicle is turning.

Further, the fifth invention is the four-wheel drive vehicle according to the third invention or the fourth invention, wherein the predetermined driving state is a driving state in which the traveling mode of the four-wheel drive vehicle is an output-oriented mode. Is.

Further, the sixth invention is the four-wheel drive vehicle according to any one of the third to fifth inventions, wherein the traveling mode of the four-wheel drive vehicle is a manual mode in the predetermined operating state. It is in the operating state.

Further, the seventh invention is the four-wheel drive vehicle according to any one of the third to sixth inventions, wherein the required braking force is equal to or more than the predetermined braking force in the predetermined driving state. It is in the operating state.

Further, the eighth invention is the four-wheel drive vehicle according to any one of the third to seventh inventions, wherein the braking operation amount is equal to or more than the predetermined braking operation amount in the predetermined operating state. It is in the operating state.

Further, the ninth invention is the four-wheel drive vehicle according to any one of the third to eighth inventions, wherein the predetermined driving state is a driving state in which the vehicle speed is equal to or higher than the predetermined vehicle speed. ..

Further, the tenth invention is the four-wheel drive vehicle according to any one of the third to ninth inventions, wherein the predetermined operating state is an operating state in which the outside air temperature is lower than the predetermined temperature. be.

According to the first invention, the regenerative control is executed by the rotating machine in the four-wheel drive state so as to realize a part or all of the required braking force at the time of deceleration of the four-wheel drive vehicle, while the regenerative control is executed. At that time, the energy obtained by subtracting the energy loss amount due to the rotation of the transmission member in the four-wheel drive state from the energy acquisition amount by the regeneration control, which is increased in the four-wheel drive state as compared with the two-wheel drive state in the disconnect state. When the balance is less than or equal to a predetermined threshold value of zero or less, the regeneration control is executed in the two-wheel drive state in the disconnected state instead of the four-wheel drive state, so that simply in the four-wheel drive state. Not only the regenerative control is executed, but also the regenerative control is executed in the two-wheel drive state in consideration of the energy loss in the four-wheel drive state. Therefore, the energy efficiency can be appropriately improved when the regenerative control by the rotating machine is executed when the vehicle is decelerated.

Further, according to the second invention, when the regenerative control is not executed when the four-wheel drive vehicle is decelerated, the vehicle is decelerated in the two-wheel drive state in the disconnected state, so that the deceleration running in the four-wheel drive state is performed. Compared to this, the decelerating distance is longer. As a result, energy efficiency can be improved even when the regenerative control is not executed when the four-wheel drive vehicle is decelerated.

Further, according to the third invention, when the operating state of the four-wheel drive vehicle is in a predetermined operating state in which the improvement of the driving performance is more important than the improvement of the energy efficiency, the operating state of the four-wheel drive vehicle is satisfied. Is set to a value smaller than that in the case where is not in the predetermined operating state, so that in a situation where improvement in driving performance is important, deceleration running is easily performed in the four-wheel drive state. As a result, it is possible to achieve both improvement in energy efficiency and improvement in operating performance.

Further, according to the fourth invention, since the predetermined driving state is a driving state in which the four-wheel drive vehicle is in a turning state, the deterioration of the driving performance during the deceleration running in the turning state is suppressed. Energy efficiency can be improved.

Further, according to the fifth aspect of the invention, since the predetermined driving state is a driving state in which the traveling mode of the four-wheel drive vehicle is the output-oriented mode, the driving performance is deteriorated during the deceleration traveling in the output-oriented mode. Energy efficiency can be improved while suppressing.

Further, according to the sixth invention, since the predetermined driving state is the driving state in which the running mode of the four-wheel drive vehicle is the manual mode, the deterioration of the driving performance during the deceleration running in the manual mode is suppressed. At the same time, energy efficiency can be improved.

Further, according to the seventh invention, since the predetermined driving state is an operating state in which the required braking force is equal to or higher than the predetermined braking force, a situation in which a large braking force is required for the four-wheel drive vehicle. It is possible to improve energy efficiency while suppressing deterioration of driving performance during deceleration running in.

Further, according to the eighth invention, since the predetermined operating state is an operating state in which the braking operation amount is equal to or larger than the predetermined braking operation amount, the vehicle is in a decelerated running state in which a sudden braking operation is performed. Energy efficiency can be improved while suppressing deterioration of driving performance.

Further, according to the ninth invention, since the predetermined driving state is a driving state in which the vehicle speed is equal to or higher than the predetermined vehicle speed, energy efficiency is improved while suppressing deterioration of driving performance during deceleration running at a high vehicle speed. Can be improved.

Further, according to the tenth invention, since the predetermined operating state is an operating state in which the outside air temperature is lower than the predetermined temperature, the driving performance during deceleration running in a situation where there is a high possibility of road surface freezing. Energy efficiency can be improved while suppressing deterioration.

It is a figure explaining the schematic structure of the four-wheel drive vehicle to which this invention is applied, and is also a figure explaining the main part of the control function and the control system for various control in a four-wheel drive vehicle. It is a figure explaining the schematic structure of the automatic transmission of FIG. FIG. 3 is an operation chart illustrating the relationship between the shift operation of the mechanical stepped speed change unit of FIG. 2 and the operation of the engagement device used thereof. It is a collinear diagram which shows the relative relationship of the rotation speed of each rotating element in the electric type continuously variable transmission part and the mechanical stepped speed change part of FIG. It is a skeleton diagram explaining the structure of the transfer of FIG. It is a figure which shows an example of the AT gear step shift map used for the shift control of a step change part, and the run mode switching map used for the change control of a run mode, and is also the figure which shows the relationship between them. It is a flowchart explaining the main part of the control operation of an electronic control device, and is a control for realizing a four-wheel drive vehicle that can appropriately improve energy efficiency when performing regenerative control by a second rotating machine at the time of vehicle deceleration. It is a flowchart explaining operation. It is a flowchart explaining the main part of the control operation of an electronic control device, and is a control for realizing a four-wheel drive vehicle that can appropriately improve energy efficiency when performing regenerative control by a second rotating machine at the time of vehicle deceleration. It is a flowchart explaining operation, and is a different embodiment from FIG. It is a flowchart explaining the main part of the control operation of an electronic control device, and is a control for realizing a four-wheel drive vehicle that can appropriately improve energy efficiency when performing regenerative control by a second rotating machine at the time of vehicle deceleration. It is a flowchart explaining the operation, and is an embodiment different from FIGS. 7 and 8.

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

FIG. 1 is a diagram for explaining a schematic configuration of a four-wheel drive vehicle 10 to which the present invention is applied, and is a diagram for explaining a main part of a control system for various controls in the four-wheel drive vehicle 10. In FIG. 1, the four-wheel drive vehicle 10 is a hybrid vehicle including an engine 12 (see “ENG” in the figure), a first rotary machine MG1 and a second rotary machine MG2 as driving force sources. Further, the four-wheel drive vehicle 10 transmits the driving force from the pair of left and right front wheels 14L and 14R, the pair of left and right rear wheels 16L and 16R, and the engine 12 and the like to the front wheels 14L and 14R and the rear wheels 16L and 16R, respectively. It is provided with a power transmission device 18. The four-wheel drive vehicle 10 is a four-wheel drive vehicle based on an FR (front engine / rear drive) type vehicle. In this embodiment, unless otherwise specified, the front wheels 14L and 14R are referred to as front wheels 14, and the rear wheels 16L and 16R are referred to as rear wheels 16. Further, the engine 12, the first rotary machine MG1, and the second rotary machine MG2 are simply referred to as a driving force source PU unless otherwise specified.

The engine 12 is a driving force source for traveling of the four-wheel drive vehicle 10, and is a known internal combustion engine such as a gasoline engine or a diesel engine. The engine 12 is the output torque of the engine 12 by controlling the engine control device 20 including the throttle actuator, the fuel injection device, the ignition device, etc. provided in the four-wheel drive vehicle 10 by the electronic control device 130 described later. The engine torque Te is controlled.

The first rotary machine MG1 and the second rotary machine MG2 are rotary electric machines having a function as an electric motor (motor) and a function as a generator (generator), and are so-called motor generators. The first rotary machine MG1 and the second rotary machine MG2 are rotary machines that can be a driving force source for traveling of the four-wheel drive vehicle 10. The first rotary machine MG1 and the second rotary machine MG2 are each connected to the battery 24 provided in the four-wheel drive vehicle 10 via the inverter 22 provided in the four-wheel drive vehicle 10. In the first rotary machine MG1 and the second rotary machine MG2, the MG1 torque Tg and the second rotary machine MG2, which are the output torques of the first rotary machine MG1, are controlled by the electronic control device 130 described later, respectively. MG2 torque Tm, which is the output torque of, is controlled. For example, in the case of forward rotation, the output torque of the rotating machine is power running torque at the positive torque on the acceleration side and regenerative torque at the negative torque on the deceleration side. The battery 24 is a power storage device that transfers and receives electric power to each of the first rotating machine MG1 and the second rotating machine MG2. The first rotary machine MG1 and the second rotary machine MG2 are provided in a case 26 which is a non-rotating member attached to a vehicle body.

The power transmission device 18 includes an automatic transmission 28 (see “T / M for HV” in the figure), a transfer 30 (see “T / F” in the figure), and a front propeller shaft 32, which are transmissions for hybrids. , The rear propeller shaft 34, the front wheel side differential gear device 36 (see "FDiff" in the figure), the rear wheel side differential gear device 38 (see "RDiff" in the figure), and a pair of left and right front wheel axles. It is equipped with 40L, 40R and a pair of left and right rear wheel axles 42L, 42R. The power transmission device 18 further includes a disconnect clutch 43 between the front wheel side differential gear device 36 and the front wheel axle 40R. The disconnect clutch 43 is a meshing type clutch, which is a disconnection / disconnection mechanism for connecting / disconnecting power transmission between the front wheel side differential gear device 36 and the front wheel axle 40R, and is a front wheel side differential gear device 36. It functions as a so-called ADD (Automatic Disconnecting Differential) mechanism for switching between a locked state and a free state. In the power transmission device 18, the driving force transmitted from the driving force source PU transmitted via the automatic transmission 28 is transmitted from the transfer 30 to the rear propeller shaft 34, the rear wheel side differential gear device 38, the rear wheel axles 42L, 42R. Etc. are sequentially transmitted to the rear wheels 16L and 16R. Further, in the power transmission device 18, when a part of the driving force transmitted from the driving force source PU transmitted to the transfer 30 is distributed to the front wheels 14L and 14R, the distributed driving force is applied to the front propeller shaft 32. It is transmitted to the front wheels 14L and 14R in sequence via the front wheel side differential gear device 36, front wheel axles 40L, 40R and the like.

The rear wheel 16 is a main drive wheel that serves as a drive wheel during both two-wheel drive and four-wheel drive. That is, the rear wheel 16 is a main driving wheel to which the driving force from the driving force source PU is transmitted. Further, the front wheels 14 are auxiliary drive wheels that become driven wheels during two-wheel drive traveling and become driving wheels during four-wheel drive traveling. That is, the front wheels 14 are auxiliary drive wheels to which a part of the driving force source PU is distributed during four-wheel drive traveling. Further, the front propeller shaft 32, the front wheel side differential gear device 36, and the like are front wheel transmission members PT as transmission members that transmit a part of the driving force from the driving force source PU distributed during four-wheel drive traveling to the front wheels 14. Is. The two-wheel drive running is a running in a two-wheel drive state in which the driving force from the driving force source PU is transmitted only to the rear wheels 16. The four-wheel drive running is a running in a four-wheel drive state in which the driving force from the driving force source PU is transmitted to the rear wheels 16 and the front wheels 14.

FIG. 2 is a diagram illustrating a schematic configuration of the automatic transmission 28. In FIG. 2, the automatic transmission 28 includes an electric continuously variable transmission unit 44, a mechanical stepped transmission unit 46, and the like, which are arranged in series on the common rotation axis CL1 in the case 26. The electric continuously variable transmission 44 is directly or indirectly connected to the engine 12 via a damper or the like (not shown). The mechanical stepped speed change unit 46 is connected to the output side of the electric type stepless speed change unit 44. A transfer 30 is connected to the output side of the mechanical stepped speed change unit 46. In the automatic transmission 28, the power output from the driving force source PU is transmitted to the mechanical stepped speed change unit 46, and is transmitted from the mechanical stepped speed change unit 46 to the transfer 30. Hereinafter, the electric continuously variable transmission unit 44 is referred to as a continuously variable transmission unit 44, and the mechanical continuously variable transmission unit 46 is referred to as a continuously variable transmission unit 46. Further, as for power, torque and force are also agreed unless otherwise specified. Further, the stepless speed change unit 44 and the stepped speed change unit 46 are configured substantially symmetrically with respect to the rotation axis CL1, and in FIG. 2, the lower half is omitted with respect to the rotation axis CL1. The rotary axis CL1 is the axis of the crank shaft of the engine 12, the connecting shaft 48 which is an input rotating member of the automatic transmission 28 connected to the crank shaft, and the output shaft 50 which is an output rotating member of the automatic transmission 28. be. The connecting shaft 48 is also an input rotating member of the stepless speed change unit 44, and the output shaft 50 is also an output rotating member of the stepped speed change unit 46.

The continuously variable transmission 44 is a power splitting mechanism that mechanically divides the power of the first rotary machine MG1 and the engine 12 into the first rotary machine MG1 and the intermediate transmission member 52 which is an output rotating member of the continuously variable transmission unit 44. The differential mechanism 54 of the above is provided. The second rotary machine MG2 is connected to the intermediate transmission member 52 so as to be able to transmit power. The continuously variable transmission 44 is an electric continuously variable transmission in which the differential state of the differential mechanism 54 is controlled by controlling the operating state of the first rotary machine MG1. The continuously variable transmission 44 is operated as an electric continuously variable transmission in which the gear ratio (also referred to as a gear ratio) γ0 (= engine rotation speed Ne / MG2 rotation speed Nm) can be changed. The engine rotation speed Ne is the rotation speed of the engine 12, and is equal to the input rotation speed of the stepless speed change unit 44, that is, the rotation speed of the connecting shaft 48. The engine rotation speed Ne is also the input rotation speed of the entire automatic transmission 28 including the continuously variable transmission unit 44 and the stepped speed change unit 46. The MG2 rotation speed Nm is the rotation speed of the second rotary machine MG2, and is equal to the output rotation speed of the continuously variable transmission 44, that is, the rotation speed of the intermediate transmission member 52. The first rotary machine MG1 is a rotary machine capable of controlling the engine rotation speed Ne. It should be noted that controlling the operating state of the first rotating machine MG1 is to control the operation of the first rotating machine MG1.

The differential mechanism 54 is composed of a single pinion type planetary gear device, and includes a sun gear S0, a carrier CA0, and a ring gear R0. The engine 12 is connected to the carrier CA0 so as to be able to transmit power via the connecting shaft 48, the first rotating machine MG1 is connected to the sun gear S0 so that power can be transmitted, and the second rotating machine MG2 can be transmitted to the ring gear R0. Is linked to. In the differential mechanism 54, the carrier CA0 functions as an input element, the sun gear S0 functions as a reaction force element, and the ring gear R0 functions as an output element.

The stepped transmission unit 46 is a stepped transmission that constitutes a power transmission path between the intermediate transmission member 52 and the transfer 30. The intermediate transmission member 52 also functions as an input rotation member of the stepped speed change unit 46. The second rotary machine MG2 is connected to the intermediate transmission member 52 so as to rotate integrally. The stepped transmission unit 46 is an automatic transmission that constitutes a part of a power transmission path between the driving force source PU for traveling and the driving wheels (front wheels 14, rear wheels 16). The stepped speed change unit 46 includes, for example, a plurality of sets of planetary gear devices of the first planetary gear device 56 and the second planetary gear device 58, and a plurality of clutches C1, clutches C2, brakes B1 and brakes B2 including a one-way clutch F1. A known planetary gear type automatic transmission equipped with an engaging device. Hereinafter, the clutch C1, the clutch C2, the brake B1, and the brake B2 are simply referred to as an engaging device CB unless otherwise specified.

The engagement device CB is a hydraulic friction engagement device composed of a multi-plate or single-plate clutch or brake pressed by a hydraulic actuator, a band brake tightened by the hydraulic actuator, or the like. The engaging device CB is in a state of being engaged or disengaged by each hydraulic pressure of the pressure-adjusted engaging device CB output from the hydraulic control circuit 60 (see FIG. 1) provided in the four-wheel drive vehicle 10. The operating state is switched.

In the stepped transmission unit 46, the rotating elements of the first planetary gear device 56 and the second planetary gear device 58 are partially connected to each other directly or indirectly via the engaging device CB or the one-way clutch F1. It is connected to the intermediate transmission member 52, the case 26, or the output shaft 50. Each rotating element of the first planetary gear device 56 is a sun gear S1, a carrier CA1, and a ring gear R1, and each rotating element of the second planetary gear device 58 is a sun gear S2, a carrier CA2, and a ring gear R2.

The stepped transmission unit 46 has a gear ratio γat (= AT input rotation speed Ni / output rotation speed No) due to engagement of, for example, a predetermined engagement device, which is one of a plurality of engagement devices. It is a stepped transmission in which any one of a plurality of gear stages (also referred to as gear gears) having different speeds is formed. That is, in the stepped speed change unit 46, the gear stage is switched, that is, the speed change is executed by engaging any one of the plurality of engaging devices. The stepped transmission unit 46 is a stepped automatic transmission in which each of a plurality of gear stages is formed. In this embodiment, the gear stage formed by the stepped transmission unit 46 is referred to as an AT gear stage. The AT input rotation speed Ni is the input rotation speed of the stepped speed change unit 46, which is the rotation speed of the input rotation member of the stepped speed change unit 46, which is the same value as the rotation speed of the intermediate transmission member 52, and MG2 rotation. It is the same value as the speed Nm. The AT input rotation speed Ni can be expressed by the MG2 rotation speed Nm. The output rotation speed No is the rotation speed of the output shaft 50, which is the output rotation speed of the stepped speed change unit 46, and is also the output rotation speed of the automatic transmission 28.

As shown in the engagement operation table of FIG. 3, for example, the stepped transmission unit 46 has AT 1st gear (“1st” in the figure) -AT 4th gear (“4th” in the figure) as a plurality of AT gears. ”) 4 stages of forward AT gear stages are formed. The gear ratio γat of the AT 1st gear is the largest, and the gear ratio γat becomes smaller as the AT gear on the higher side. Further, the reverse AT gear stage (“Rev” in the figure) is formed, for example, by engaging the clutch C1 and engaging the brake B2. That is, when traveling in reverse, for example, an AT 1st gear stage is formed. The engagement operation table of FIG. 3 summarizes the relationship between each AT gear stage and each operation state of the plurality of engagement devices. That is, the engagement operation table of FIG. 3 summarizes the relationship between each AT gear stage and a predetermined engagement device which is an engagement device that is engaged with each AT gear stage. In FIG. 3, “◯” indicates engagement, “Δ” indicates engagement during engine braking or coast downshift of the stepped transmission unit 46, and blank indicates release.

In the stepped transmission unit 46, the AT gear stages formed according to the accelerator operation of the driver (that is, the driver), the vehicle speed Vv, etc. are switched by the electronic control device 130 described later, that is, a plurality of AT gear stages are selectively selected. Is formed in. For example, in the shift control of the stepped speed change unit 46, the shift is executed by gripping any one of the engaging devices CB, that is, the shifting is executed by switching between the engagement and the disengagement of the engagement device CB. So-called clutch-to-clutch shifting is performed.

The four-wheel drive vehicle 10 further includes a one-way clutch F0, a mechanical oil pump MOP62, an electric oil pump (not shown), and the like.

The one-way clutch F0 is a locking mechanism capable of fixing the carrier CA0 so as not to rotate. That is, the one-way clutch F0 is a lock mechanism capable of fixing the connecting shaft 48, which is connected to the crank shaft of the engine 12 and rotates integrally with the carrier CA0, to the case 26. In the one-way clutch F0, one member of the two relative rotatable members is integrally connected to the connecting shaft 48, and the other member is integrally connected to the case 26. The one-way clutch F0 idles in the forward rotation direction, which is the rotation direction of the engine 12 during operation, and mechanically automatically engages with the rotation direction opposite to that during operation of the engine 12. Therefore, when the one-way clutch F0 idles, the engine 12 is in a state of being able to rotate relative to the case 26. On the other hand, when the one-way clutch F0 is engaged, the engine 12 is in a state where it cannot rotate relative to the case 26. That is, the engine 12 is fixed to the case 26 by engaging the one-way clutch F0. As described above, the one-way clutch F0 allows the carrier CA0 to rotate in the positive rotation direction, which is the rotation direction during operation of the engine 12, and prevents the carrier CA0 from rotating in the negative rotation direction. That is, the one-way clutch F0 is a locking mechanism capable of allowing the engine 12 to rotate in the positive rotation direction and preventing the engine 12 from rotating in the negative rotation direction.

The MOP 62 is connected to the connecting shaft 48 and is rotated with the rotation of the engine 12 to discharge the hydraulic oil OIL used in the power transmission device 18. Further, the electric oil pump (not shown) is driven, for example, when the engine 12 is stopped, that is, when the MOP 62 is not driven. The hydraulic oil OIL discharged by the MOP 62 or an electric oil pump (not shown) is supplied to the hydraulic control circuit 60. The hydraulic oil OIL is adjusted to each hydraulic pressure of the engaging device CB by the hydraulic pressure control circuit 60 and supplied to the power transmission device 18 (see FIG. 1).

FIG. 4 is a collinear diagram showing the relative relationship between the rotation speeds of the rotating elements in the stepless speed change unit 44 and the stepped speed change unit 46. In FIG. 4, the three vertical lines Y1, Y2, and Y3 corresponding to the three rotating elements of the differential mechanism 54 constituting the stepless speed change unit 44 are the sun gear S0 corresponding to the second rotating element RE2 in order from the left side. The g-axis representing the rotation speed, the e-axis representing the rotation speed of the carrier CA0 corresponding to the first rotation element RE1, and the rotation speed of the ring gear R0 corresponding to the third rotation element RE3 (that is, the stepped speed change unit 46). It is an m-axis representing an input rotation speed). Further, the four vertical lines Y4, Y5, Y6, and Y7 of the stepped speed change unit 46 correspond to the rotation speed of the sun gear S2 corresponding to the fourth rotation element RE4 and the rotation speed of the sun gear S2 corresponding to the fifth rotation element RE5 in order from the left. Corresponds to the rotational speed of the connected ring gear R1 and carrier CA2 (that is, the rotational speed of the output shaft 50), the rotational speed of the interconnected carrier CA1 and ring gear R2 corresponding to the sixth rotational element RE6, and the seventh rotational element RE7. It is a shaft which represents the rotation speed of the sun gear S1 to be carried. The distance between the vertical lines Y1, Y2, and Y3 is determined according to the gear ratio ρ0 of the differential mechanism 54. Further, the distance between the vertical lines Y4, Y5, Y6, and Y7 is determined according to the gear ratios ρ1 and ρ2 of the first and second planetary gear devices 56 and 58. When the distance between the sun gear and the carrier is set to correspond to "1" in the relationship between the vertical axes of the co-line diagram, the gear ratio ρ (= number of teeth of the sun gear / ring gear) of the planetary gear device is between the carrier and the ring gear. The interval corresponds to the number of teeth).

Expressed using the co-line diagram of FIG. 4, in the differential mechanism 54 of the continuously variable transmission unit 44, the engine 12 (see “ENG” in the figure) is connected to the first rotation element RE1 and the second rotation element is connected. The first rotary machine MG1 (see "MG1" in the figure) is connected to RE2, and the second rotary machine MG2 (see "MG2" in the figure) is connected to the third rotary element RE3 that rotates integrally with the intermediate transmission member 52. The rotation of the engine 12 is transmitted to the stepped speed change unit 46 via the intermediate transmission member 52. In the continuously variable transmission unit 44, the relationship between the rotation speed of the sun gear S0 and the rotation speed of the ring gear R0 is shown by the straight lines L0e, L0m, and L0R that cross the vertical line Y2.

Further, in the stepped speed change unit 46, the fourth rotation element RE4 is selectively connected to the intermediate transmission member 52 via the clutch C1, the fifth rotation element RE5 is connected to the output shaft 50, and the sixth rotation element RE6 is It is selectively coupled to the intermediate transmission member 52 via the clutch C2 and selectively coupled to the case 26 via the brake B2, and the seventh rotating element RE7 is selectively coupled to the case 26 via the brake B1. To. In the stepped speed change unit 46, “1st”, “2nd”, “3rd” on the output shaft 50 are formed by the straight lines L1, L2, L3, L4, and LR crossing the vertical line Y5 by the engagement release control of the engagement device CB. , "4th", and "Rev" rotation speeds are shown.

The straight lines L0e and the straight lines L1, L2, L3, and L4 shown by the solid lines in FIG. 4 are each in forward running in the HV running mode capable of hybrid running (= HV running) in which the engine 12 is used as a driving force source. It shows the relative velocity of the rotating element. In this HV traveling mode, in the differential mechanism 54, MG1 torque Tg, which is a reaction force torque of negative torque by the first rotary machine MG1, is input to the sun gear S0 with respect to the positive torque engine torque Te input to the carrier CA0. Then, the engine direct torque Td (= Te / (1 + ρ0) = − (1 / ρ0) × Tg) which becomes a positive torque in the forward rotation appears in the ring gear R0. Then, according to the required driving force, the total torque of the engine direct torque Td and the MG2 torque Tm is one of the AT 1st gear stage and the AT 4th gear stage as the driving torque in the forward direction of the four-wheel drive vehicle 10. It is transmitted to the transfer 30 via the stepped speed change unit 46 in which the AT gear stage is formed. The first rotary machine MG1 functions as a generator when a negative torque is generated in the forward rotation. The generated power Wg of the first rotating machine MG1 is charged in the battery 24 or consumed by the second rotating machine MG2. The second rotary machine MG2 outputs MG2 torque Tm by using all or a part of the generated power Wg, or by using the power from the battery 24 in addition to the generated power Wg.

The straight line L0m shown by the alternate long and short dash line in FIG. 4 and the straight lines L1, L2, L3, and L4 shown by the solid line in FIG. 4 are among the first rotary machine MG1 and the second rotary machine MG2 with the operation of the engine 12 stopped. It shows the relative speed of each rotating element in the forward running in the EV running mode capable of motor running (= EV running) running by using at least one of the rotating machines as a driving force source. As EV running in the forward running in the EV running mode, for example, a single drive EV running using only the second rotating machine MG2 as a driving force source and a single drive EV running using only the second rotating machine MG1 and the second rotating machine MG2 as the driving force sources. There is a double-drive EV running that runs. In single-drive EV traveling, the carrier CA0 is set to zero rotation, and MG2 torque Tm, which is a positive torque in normal rotation, is input to the ring gear R0. At this time, the first rotary machine MG1 connected to the sun gear S0 is put into a no-load state and is idled by negative rotation. In the single drive EV traveling, the one-way clutch F0 is released, and the connecting shaft 48 is not fixed to the case 26.

In both drive EV running, if MG1 torque Tg, which becomes a negative torque due to negative rotation, is input to the sun gear S0 while the carrier CA0 is set to zero rotation, the rotation of the carrier CA0 in the negative rotation direction is prevented. The one-way clutch F0 is automatically engaged as described above. In a state where the carrier CA0 is fixed so as not to rotate by the engagement of the one-way clutch F0, the reaction force torque due to the MG1 torque Tg is input to the ring gear R0. In addition, in the double-drive EV running, the MG2 torque Tm is input to the ring gear R0 as in the single-drive EV running. When MG1 torque Tg, which becomes negative torque due to negative rotation, is input to the sun gear S0 with carrier CA0 set to zero rotation, if MG2 torque Tm is not input, single drive EV running with MG1 torque Tg is also possible. It is possible. In forward driving in the EV driving mode, the engine 12 is not driven, the engine rotation speed Ne is set to zero, and at least one of the MG1 torque Tg and the MG2 torque Tm drives the four-wheel drive vehicle 10 in the forward direction. The torque is transmitted to the transfer 30 via the stepped speed change unit 46 in which any one of the AT 1st gear stage and the AT 4th gear stage is formed. In the forward running in the EV running mode, the MG1 torque Tg is the power running torque of negative rotation and negative torque, and the MG2 torque Tm is the power running torque of positive rotation and positive torque.

The straight line L0R and the straight line LR shown by the broken line in FIG. 4 indicate the relative speed of each rotating element in the reverse running in the EV running mode. In reverse travel in this EV drive mode, MG2 torque Tm, which becomes a negative torque due to negative rotation, is input to the ring gear R0, and the MG2 torque Tm is used as the drive torque in the reverse direction of the four-wheel drive vehicle 10 to be the AT 1st gear. It is transmitted to the transfer 30 via the stepped speed change unit 46 in which a step is formed. In the four-wheel drive vehicle 10, the electronic control device 130 described later forms an AT gear stage on the low side for forward movement among a plurality of AT gear stages, for example, an AT 1st gear stage, and the vehicle is traveling forward. The reverse MG2 torque Tm, whose positive and negative directions are opposite to those of the forward MG2 torque Tm, is output from the second rotary machine MG2, so that the reverse traveling can be performed. In the reverse running in the EV running mode, the MG2 torque Tm is a power running torque of negative rotation and negative torque. Even in the HV traveling mode, since the second rotary machine MG2 can be negatively rotated as in the straight line L0R, it is possible to perform reverse traveling in the same manner as in the EV traveling mode.

FIG. 5 is an outline diagram illustrating the structure of the transfer 30. The transfer 30 includes a transfer case 64 as a non-rotating member. The transfer 30 includes a rear wheel side output shaft 66, a front wheel drive drive gear 68, and a front wheel drive clutch 70 in the transfer case 64 around a common rotation axis CL1. Further, the transfer 30 includes a front wheel side output shaft 72 and a front wheel drive driven gear 74 in the transfer case 64 centering on a common rotation axis CL2. Further, the transfer 30 includes a front wheel drive idler gear 76. The rotation axis CL2 is the axis of the front propeller shaft 32, the front wheel side output shaft 72, and the like.

The rear wheel side output shaft 66 is connected to the output shaft 50 so as to be able to transmit power, and is also connected to the rear propeller shaft 34 so as to be able to transmit power. The rear wheel side output shaft 66 outputs the driving force transmitted from the driving force source PU to the output shaft 50 via the automatic transmission 28 to the rear wheels 16. The output shaft 50 transmits the driving force from the driving force source PU to the input rotating member of the transfer 30 that inputs the driving force from the driving force source PU to the rear wheel side output shaft 66 of the transfer 30. It also functions as a driving force transmission shaft. The automatic transmission 28 is an automatic transmission that transmits the driving force from the driving force source PU to the output shaft 50.

The front wheel drive drive gear 68 is provided so as to be rotatable relative to the rear wheel side output shaft 66. The front wheel drive clutch 70 is a multi-plate wet clutch, and adjusts the transmission torque transmitted from the rear wheel side output shaft 66 to the front wheel drive drive gear 68. That is, the front wheel drive clutch 70 adjusts the transmission torque transmitted from the rear wheel side output shaft 66 to the front wheel side output shaft 72.

The front wheel drive driven gear 74 is integrally provided on the front wheel side output shaft 72, and is connected to the front wheel side output shaft 72 so as to be able to transmit power. The front wheel drive idler gear 76 is meshed with the front wheel drive drive gear 68 and the front wheel drive driven gear 74, respectively, and is connected between the front wheel drive drive gear 68 and the front wheel drive driven gear 74 so as to be able to transmit power.

The front wheel side output shaft 72 is connected to the front wheel drive drive gear 68 via a front wheel drive idler gear 76 and a front wheel drive driven gear 74 so as to be able to transmit power, and is also connected to the front propeller shaft 32 so as to be able to transmit power. There is. The front wheel side output shaft 72 outputs a part of the driving force from the driving force source PU transmitted to the front wheel driving drive gear 68 via the front wheel driving clutch 70 to the front wheels 14. The front wheel drive drive gear 68, the front wheel side output shaft 72, the front wheel drive driven gear 74, the front wheel drive idler gear 76, and the like are front wheel transmission members PT.

The front wheel drive clutch 70 includes a clutch hub 78, a clutch drum 80, a friction engagement element 82, and a piston 84. The clutch hub 78 is connected to the rear wheel side output shaft 66 so as to be able to transmit power. The clutch drum 80 is connected to the front wheel drive drive gear 68 so as to be able to transmit power. The friction engaging element 82 is provided with respect to a plurality of first friction plates 82a provided so as to be relatively movable in the direction of the rotation axis CL1 with respect to the clutch hub 78 and not to be relatively rotatable with respect to the clutch hub 78, and the clutch drum 80. It has a plurality of second friction plates 82b provided so as to be relatively movable in the direction of the rotation axis CL1 and not to be relatively rotatable with respect to the clutch drum 80. The first friction plate 82a and the second friction plate 82b are arranged so as to alternately overlap each other in the direction of the rotation axis CL1. The piston 84 is provided so as to be movable in the direction of the rotation axis CL1 and abuts on the friction engaging element 82 to press the first friction plate 82a and the second friction plate 82b to press the torque capacity of the front wheel drive clutch 70. Is adjusted. If the piston 84 does not press the friction engagement element 82, the torque capacity of the front wheel drive clutch 70 becomes zero, and the front wheel drive clutch 70 is released.

By adjusting the torque capacity of the front wheel drive clutch 70, the transfer 30 transfers the drive force of the drive force source PU transmitted via the automatic transmission 28 to the rear wheel side output shaft 66 and the front wheel side output shaft 72. Allocate. When the front wheel drive clutch 70 is released, the transfer 30 automatically disconnects the power transmission path between the rear wheel side output shaft 66 and the front wheel drive drive gear 68 from the drive force source PU. The driving force transmitted to the transfer 30 via the transmission 28 is transmitted to the rear wheels 16 via the rear propeller shaft 34 and the like. Further, in the transfer 30, when the front wheel drive clutch 70 is in the slip engaged state or the fully engaged state, the power transmission path between the rear wheel side output shaft 66 and the front wheel drive drive gear 68 is connected. Therefore, a part of the driving force transmitted from the driving force source PU via the transfer 30 is transmitted to the front wheels 14 via the front propeller shaft 32 and the like, and the rest of the driving force is transmitted to the front wheels 14 via the rear propeller shaft 34 and the like. It is transmitted to the rear wheel 16. The front wheel drive clutch 70 is a drive force distribution clutch that distributes the drive force from the drive force source PU to the front wheels 14 and the rear wheels 16. The transfer 30 is a driving force distribution device capable of transmitting the driving force from the driving force source PU to the front wheels 14 and the rear wheels 16.

The transfer 30 includes an electric motor 86, a worm gear 88, and a cam mechanism 90 as a device for operating the front wheel drive clutch 70.

The worm gear 88 is a gear pair including a worm 92 integrally formed on the motor shaft of the electric motor 86 and a worm wheel 94 formed with teeth that mesh with the worm 92. The worm wheel 94 is rotatably provided about the rotation axis CL1. When the electric motor 86 is rotated, the worm wheel 94 is rotated about the rotation axis CL1.

The cam mechanism 90 is provided between the worm wheel 94 and the piston 84 of the front wheel drive clutch 70. The cam mechanism 90 is interposed between the first member 96 connected to the worm wheel 94, the second member 98 connected to the piston 84, and the first member 96 and the second member 98. It is provided with a plurality of balls 99, and is a mechanism for converting the rotational motion of the electric motor 86 into a straight motion.

The plurality of balls 99 are arranged at equal angular intervals in the rotation direction about the rotation axis CL1. A cam groove is formed on each of the surfaces of the first member 96 and the second member 98 in contact with the ball 99. Each cam groove is formed so that the first member 96 and the second member 98 are separated from each other in the rotation axis CL1 direction when the first member 96 rotates relative to the second member 98. Therefore, when the first member 96 rotates relative to the second member 98, the first member 96 and the second member 98 are separated from each other, and the second member 98 is moved in the rotation axis CL1 direction, and the second member The piston 84 connected to 98 presses the friction engagement element 82. When the worm wheel 94 is rotated by the electric motor 86, the rotational motion of the worm wheel 94 is converted into a linear motion in the direction of the rotation axis CL1 via the cam mechanism 90 and transmitted to the piston 84, and the piston 84 engages in friction. Press the element 82. The torque capacity of the front wheel drive clutch 70 is adjusted by adjusting the pressing force on which the piston 84 presses the friction engaging element 82. The transfer 30 adjusts the driving force distribution ratio Rx, which is the ratio of the driving force from the driving force source PU distributed to the front wheels 14 and the rear wheels 16, by adjusting the torque capacity of the front wheel drive clutch 70. Can be done.

The driving force distribution ratio Rx is, for example, the ratio of the driving force transmitted to the rear wheels 16 to the total driving force transmitted from the driving force source PU to the rear wheels 16 and the front wheels 14, that is, the rear wheel side distribution ratio Xr. Alternatively, the driving force distribution ratio Rx is, for example, the ratio of the driving force transmitted to the front wheels 14 to the total driving force transmitted from the driving force source PU to the rear wheels 16 and the front wheels 14, that is, the front wheel side distribution ratio Xf (= 1-). Xr). In this embodiment, since the rear wheels 16 are the main driving wheels, the rear wheel side distribution ratio Xr, which is the main side distribution ratio, is used as the driving force distribution ratio Rx.

When the piston 84 does not press the friction engagement element 82, the torque capacity of the front wheel drive clutch 70 becomes zero. At this time, the front wheel drive clutch 70 is released, and the rear wheel side distribution ratio Xr becomes 1.0. In other words, the distribution of the driving force to the front wheels 14 and the rear wheels 16, that is, the distribution of the driving force of the front and rear wheels is expressed by "driving force of the front wheels 14: driving force of the rear wheels 16" with the total driving force as 100. The driving force distribution of the front and rear wheels is 0: 100. On the other hand, when the piston 84 presses the friction engagement element 82, the torque capacity of the front wheel drive clutch 70 becomes larger than zero, and the torque capacity of the front wheel drive clutch 70 increases, the rear wheel side distribution increases. The rate Xr decreases. When the torque capacity at which the front wheel drive clutch 70 is completely engaged is reached, the rear wheel side distribution ratio Xr becomes 0.5. In other words, the driving force distribution of the front and rear wheels is in equilibrium at 50:50. In this way, the transfer 30 adjusts the torque capacity of the front wheel drive clutch 70 so that the rear wheel side distribution ratio Xr is between 1.0 and 0.5, that is, the front and rear wheel drive force distribution is 0 :. It can be adjusted between 100 and 50:50. That is, the transfer 30 can switch the four-wheel drive vehicle 10 between the two-wheel drive state and the four-wheel drive state.

Returning to FIG. 1, the four-wheel drive vehicle 10 includes a wheel brake device 100. The wheel brake device 100 includes a wheel brake 101, a brake master cylinder (not shown), and the like, and applies braking force by the wheel brake 101 to each of the wheels 14 and 16 of the front wheels 14 and the rear wheels 16. The wheel brake 101 is a front brake 101FL, 101FR provided on each of the front wheels 14L, 14R, and a rear brake 101RL, 101RR provided on each of the rear wheels 16L, 16R. The wheel brake device 100 supplies brake hydraulic pressure to wheel cylinders (not shown) provided on the wheel brake 101 in response to, for example, a driver stepping on the brake pedal. In the wheel brake device 100, a master cylinder hydraulic pressure having a magnitude corresponding to the braking operation amount Bra, which is normally generated from the brake master cylinder, is supplied to the wheel cylinder as the brake hydraulic pressure. On the other hand, in the wheel brake device 100, for example, when the ABS function is activated, when the braking force distribution is controlled, when the brake assist function is activated, when the TRC function is activated, when the skid suppression control called VSC is performed, when the vehicle speed is controlled, and when the automatic brake function is activated. At times, the brake hydraulic force of a magnitude corresponding to the braking force required for each control is supplied to the wheel cylinder due to the generation of the braking force by the wheel brake 101. The braking operation amount Bra is a signal indicating the magnitude of the brake pedal depression operation by the driver, that is, the magnitude of the braking operation, corresponding to the pedaling force of the brake pedal. In this way, the wheel brake device 100 can adjust the braking force applied to each of the wheels 14 and 16 by the wheel brake 101.

Further, the four-wheel drive vehicle 10 is provided with an electric actuator 102 for switching the operating state of the disconnection clutch 43. The operation state of the disconnect clutch 43 is switched by controlling the electric actuator 102 by the electronic control device 130 described later. The disconnect clutch 43 cuts off the power transmission path between the front wheel side differential gear device 36 and the front wheel 14R when released, while the disconnect clutch 43 and the front wheel side differential gear device 36 are engaged. Connect the power transmission path to the front wheel 14R. In this way, the disconnect clutch 43 selectively switches between disconnection and connection of power transmission between the front wheel side differential gear device 36 and the front wheel 14R.

When the front wheel drive clutch 70 is slip-engaged or fully engaged, that is, when the front wheel drive clutch 70 is engaged and the disconnect clutch 43 is engaged, the transfer 30 distributes the clutch 70. A part of the driving force from the driving force source PU is transmitted to the front wheel side differential gear device 36 via the front propeller shaft 32, and is transmitted to the front wheels 14L and 14R via the front wheel axles 40L and 40R. The four-wheel drive vehicle 10 is in a four-wheel drive state.

On the other hand, in the state where the front wheel drive clutch 70 is released, the drive force from the drive force source PU is transmitted only to the rear wheels 16, so that the four-wheel drive vehicle 10 is in the two-wheel drive state. At this time, when the disconnect clutch 43 is engaged, the front wheel transmission member PT is rotated by the front wheel 14. Alternatively, even when the disconnect clutch 43 is released, the four-wheel drive vehicle 10 is in a two-wheel drive state, but when the front wheel drive clutch 70 is engaged, the rear wheel side output shaft 66 causes the four-wheel drive vehicle 10 to be in a two-wheel drive state. The front wheel transmission member PT is taken around. Then, in the four-wheel drive vehicle 10, energy loss occurs due to the rotation of the front wheel transmission member PT, and the energy efficiency is lowered. In response to such a decrease in energy efficiency, in the four-wheel drive vehicle 10, when the front-wheel drive clutch 70 and the disconnect clutch 43 are both released when the two-wheel drive state is set, the disconnect state is set. The front wheel transmission member PT is not rotated around, and energy loss can be suppressed. The front wheel drive clutch 70 is a first clutch capable of connecting and disconnecting power transmission between the drive force source PU and the front wheel transmission member PT. The disconnect clutch 43 is a second clutch capable of connecting and disconnecting power transmission between the front wheel transmission member PT and the front wheel 14.

Further, the four-wheel drive vehicle 10 includes an electronic control device 130 as a controller including a control device for the four-wheel drive vehicle 10 that controls a driving force source PU, a front wheel drive clutch 70, a disconnection clutch 43, and the like. There is. FIG. 1 is a diagram showing an input / output system of the electronic control device 130, and is a functional block diagram illustrating a main part of a control function by the electronic control device 130. The electronic control device 130 includes, for example, a so-called microcomputer provided with a CPU, RAM, ROM, an input / output interface, etc., and the CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Various controls of the four-wheel drive vehicle 10 are executed by performing signal processing. The electronic control device 130 includes computers for engine control, shift control, and the like, if necessary.

The electronic control device 130 includes various sensors provided in the four-wheel drive vehicle 10 (for example, engine rotation speed sensor 103, output rotation speed sensor 104, MG1 rotation speed sensor 106, MG2 rotation speed sensor 108, wheels 14, 16 respectively. Wheel speed sensor 110, accelerator opening sensor 112, throttle valve opening sensor 114, brake pedal sensor 116, G sensor 118, shift position sensor 120, yaw rate sensor 122, steering sensor 124, traveling mode selection switch 125, which are provided for each. , Battery sensor 126, oil temperature sensor 127, outside temperature sensor 128, etc.) Various signals based on the detected values (for example, engine rotation speed Ne, output rotation speed No corresponding to vehicle speed Vv, rotation speed of the first rotary machine MG1) A certain MG1 rotation speed Ng, MG2 rotation speed Nm which is the same value as AT input rotation speed Ni, wheel speed Nr which is the rotation speed of each wheel 14 and 16, and the accelerator operation amount of the driver indicating the magnitude of the driver's acceleration operation. The accelerator opening θacc, the throttle valve opening θth, which is the opening of the electronic throttle valve, and the brake on signal Bon, which is a signal indicating that the brake pedal for operating the wheel brake 101 is being operated by the driver. Braking operation amount Bra, front-rear acceleration Gx and left-right acceleration Gy of the four-wheel drive vehicle 10, operation position POSsh of the shift lever 129 provided in the four-wheel drive vehicle 10, a vehicle around the vertical axis passing through the center of gravity of the four-wheel drive vehicle 10. The yaw angle speed Vyaw, which is the speed of change of the rotation angle, the steering angle θsw and steering direction Dsw of the steering wheel provided in the four-wheel drive vehicle 10, and the eco mode on, which is a signal indicating that the eco mode is selected by the driver. Signal ECOon, power mode on signal PWRon which is a signal indicating that the power mode is selected by the driver, battery temperature THbat of the battery 24, battery charge / discharge current Ibat, battery voltage Vbat, operation which is the temperature of the hydraulic oil OIL. The oil temperature THoil, the outside temperature THair around the four-wheel drive vehicle 10, etc.) are supplied respectively.

The accelerator operation amount of the driver is an acceleration operation amount which is an operation amount of an accelerator operation member such as an accelerator pedal, and is an output request amount of the driver for the four-wheel drive vehicle 10. As the output request amount of the driver, a throttle valve opening degree θth or the like can be used in addition to the accelerator opening degree θacc.

The shift lever 129 is a shift operation member operated by the driver to any operation position among the plurality of operation positions POSsh. The operation position POSsh is an operation position of the shift lever 129, and includes, for example, P, R, N, D, and M operation positions.

The P operation position is a parking operation position for selecting the parking position (= P position) of the automatic transmission 28. The P position of the automatic transmission 28 is a shift position of the automatic transmission 28 in which the automatic transmission 28 is in the neutral state and the rotation of the output shaft 50 is mechanically blocked. The neutral state of the automatic transmission 28 is a state in which the continuously variable transmission 44 cannot transmit the engine torque Te because, for example, the first rotary machine MG1 is idled in a no-load state and does not take a reaction torque with respect to the engine torque Te. It is realized by the fact that the second rotary machine MG2 is idled in a no-load state and the power transmission in the automatic transmission 28 is cut off. The state in which the rotation of the output shaft 50 is mechanically blocked is a state in which the output shaft 50 is non-rotatably fixed by a known parking lock mechanism provided in the four-wheel drive vehicle 10. The R operation position is a reverse travel operation position for selecting the reverse travel position (= R position) of the automatic transmission 28. The R position of the automatic transmission 28 is a shift position of the automatic transmission 28 that enables the four-wheel drive vehicle 10 to travel backward. The N operation position is a neutral position (= N position) of the automatic transmission 28, that is, a neutral operation position for selecting a neutral position. The N position of the automatic transmission 28 is the shift position of the automatic transmission 28 in which the automatic transmission 28 is in the neutral state. The D operation position is a forward travel operation position for selecting the forward travel position (= D position) of the automatic transmission 28. The D position of the automatic transmission 28 is a shift position of the automatic transmission 28 that executes automatic shift control of the automatic transmission 28 to enable the four-wheel drive vehicle 10 to travel forward. The M operation position is a manual shift operation position that selects a manual mode as the traveling mode of the four-wheel drive vehicle 10. The manual mode is a predetermined traveling mode that enables manual shifting of the automatic transmission 28 by a shift operation by the driver. The shift operation by the driver is, for example, a shift operation for operating the shift lever 129 to either the "+" position or the "-" position provided so as to sandwich the M operation position. The shift operation to the "+" position is an upshift operation that requires an upshift of the automatic transmission 28. The shift operation to the "-" position is a downshift operation that requires a downshift of the automatic transmission 28. The four-wheel drive vehicle 10 may include, for example, a paddle switch (not shown) having an upshift switch “+” and a downshift switch “−” provided on the steering wheel. In such a case, the shift operation by the driver is a shift operation by operating such a paddle switch. When the four-wheel drive vehicle 10 is provided with the paddle switch, the automatic transmission 28 can be manually changed by operating the paddle switch even when the operation position POSsh is in the D operation position. .. In the D operation position of the operation position POSsh, for example, the automatic transmission mode is established as the driving mode of the four-wheel drive vehicle 10, but the manual mode is temporarily established for a certain period from the time when the paddle switch is operated. May be.

The travel mode selection switch 125 is an operation member that enables the driver to select the travel mode of the four-wheel drive vehicle 10 desired by the driver. The driving modes that can be selected by the traveling mode selection switch 125 are, for example, a normal mode, an eco mode, and a power mode. When neither the eco mode nor the power mode is selected in the traveling mode selection switch 125, the normal mode is selected. The normal mode is, for example, a predetermined normal driving mode for driving so as to be able to operate in an energy-efficient state while drawing out power performance. The eco mode is a predetermined driving mode for driving so that the vehicle can be driven in a state where the improvement of energy efficiency is prioritized over the improvement of power performance as compared with the normal mode, for example. The power mode is a predetermined driving mode for driving so as to be able to operate in a state where improvement of power performance is prioritized over improvement of energy efficiency as compared with, for example, a normal mode. That is, the power mode is an output-oriented mode that emphasizes improving power performance rather than improving energy efficiency, for example.

From the electronic control device 130, various commands are given to each device (for example, engine control device 20, inverter 22, hydraulic control circuit 60, electric motor 86, wheel brake device 100, electric actuator 102, etc.) provided in the four-wheel drive vehicle 10. Signals (for example, an engine control command signal Se for controlling the engine 12, a rotary machine control command signal Smg for controlling the first rotary machine MG1 and the second rotary machine MG2, and an operating state of the engagement device CB are controlled. Hydraulic control command signal Sat for, electric motor control command signal Sw for adjusting driving force distribution ratio Rx, brake control command signal Sb for controlling braking force by wheel brake 101, operating state of disconnect clutch 43 (Electric actuator control command signal Sadd, etc.) for controlling the above is output.

In order to realize various controls in the four-wheel drive vehicle 10, the electronic control device 130 includes an AT shift control means, that is, an AT shift control unit 132, a hybrid control means, that is, a hybrid control unit 134, and a four-wheel drive control means, that is, a four-wheel drive control. A unit 136 and a braking force control means, that is, a braking force control unit 138 are provided.

The AT shift control unit 132 is a stepped transmission unit 46 using an AT gear shift map as shown in FIG. 6, for example, which is a relationship that is experimentally or designedly obtained and stored in advance, that is, a predetermined relationship. The hydraulic pressure control command signal Sat for executing the shift control of the stepped transmission unit 46 is output to the hydraulic pressure control circuit 60. The AT gear shift map has, for example, a predetermined relationship having a shift line for determining the shift of the stepped shift unit 46 on two-dimensional coordinates with the vehicle speed Vv and the required driving force Frid as variables. Here, the output rotation speed No or the like may be used instead of the vehicle speed Vv. Further, instead of the required driving force Frdem, the required driving torque Trdem, the accelerator opening degree θacc, the throttle valve opening degree θth, or the like may be used. Each shift line in the AT gear shift map is an upshift line for determining an upshift as shown by a solid line and a downshift line for determining a downshift as shown by a broken line.

The hybrid control unit 134 functions as an engine control means for controlling the operation of the engine 12, that is, an engine control unit 134a, and a rotary machine control for controlling the operation of the first rotary machine MG1 and the second rotary machine MG2 via the inverter 22. The means, that is, the function as the rotary machine control unit 134b, is included, and the hybrid drive control by the engine 12, the first rotary machine MG1, and the second rotary machine MG2 is executed by those control functions.

The hybrid control unit 134 calculates the required driving force Frdem as the driving required amount by applying the accelerator opening degree θacc and the vehicle speed Vv to, for example, the driving required amount map having a predetermined relationship. The required driving amount includes, in addition to the required driving force Frdem [N], the required driving torque Trdem [Nm] for each drive wheel (front wheel 14, rear wheel 16), the required drive power Prdem [W] for each drive wheel, and the required drive power Prdem [W]. The required AT output torque or the like on the output shaft 50 can also be used. The hybrid control unit 134 is a command to control the engine 12 so as to realize the required drive power Prdem based on the required drive torque Trdem and the vehicle speed Vv in consideration of the rechargeable power Win and the dischargeable power Wout of the battery 24. The engine control command signal Se, which is a signal, and the rotary machine control command signal Smg, which is a command signal for controlling the first rotary machine MG1 and the second rotary machine MG2, are output. The engine control command signal Se is, for example, a command value of the engine power Pe, which is the power of the engine 12 that outputs the engine torque Te at the engine rotation speed Ne at that time. The rotary machine control command signal Smg is, for example, a command value of the generated power Wg of the first rotary machine MG1 that outputs the MG1 torque Tg at the MG1 rotation speed Ng at the time of command output as the reaction torque of the engine torque Te. It is a command value of the power consumption Wm of the second rotary machine MG2 that outputs the MG2 torque Tm at the MG2 rotation speed Nm at the time of command output.

The rechargeable power Win of the battery 24 is the maximum input power that defines the limit of the input power of the battery 24, and indicates the input limit of the battery 24. The dischargeable power Wout of the battery 24 is the maximum power that can be output that defines the limit of the output power of the battery 24, and indicates the output limit of the battery 24. The rechargeable power Win and the dischargeable power Wout of the battery 24 are calculated by the electronic control device 130 based on, for example, the battery temperature THbat and the charge state value SOC [%] of the battery 24. The charge state value SOC of the battery 24 is a value indicating a charge state corresponding to the charge amount of the battery 24, and is calculated by the electronic control device 130 based on, for example, the battery charge / discharge current Ibat and the battery voltage Vbat.

When the hybrid control unit 134 operates the continuously variable transmission 44 as a continuously variable transmission and operates the automatic transmission 28 as a whole as a continuously variable transmission, the required drive power Prdem takes into consideration the optimum engine operating point and the like. By controlling the engine 12 and controlling the generated power Wg of the first continuously variable transmission MG1 so that the engine rotation speed Ne and the engine torque Te are such that the engine power Pe that realizes the above can be obtained, there is no stepless transmission 44. The step shift control is executed to change the shift ratio γ0 of the continuously variable transmission unit 44. As a result of this control, the gear ratio γt (= γ0 × γat = Ne / No) of the automatic transmission 28 when operated as a continuously variable transmission is controlled. The optimum engine operating point is, for example, an engine operating point that gives the best total fuel efficiency in a four-wheel drive vehicle 10 in consideration of the fuel efficiency of the engine 12 alone and the charge / discharge efficiency of the battery 24 when the required engine power Pedem is realized. It has been decided. This engine operating point is the operating point of the engine 12 represented by the engine rotation speed Ne and the engine torque Te. The engine rotation speed Ne at the optimum engine operating point is the optimum engine rotation speed Ne that has the best energy efficiency in the four-wheel drive vehicle 10.

The hybrid control unit 134 has a predetermined relationship, for example, when the stepless transmission unit 44 is changed like a stepped transmission and the automatic transmission 28 as a whole is changed like a stepped transmission. The shift judgment of the automatic transmission 28 is performed using the shift map, and a plurality of gear stages having different gear ratios γt are selectively selected in cooperation with the shift control of the AT gear stage of the stepped shift unit 46 by the AT shift control unit 132. The speed change control of the stepless speed change unit 44 is executed so as to be established in. The plurality of gear stages can be established by controlling the engine rotation speed Ne by the first rotary machine MG1 according to the output rotation speed No so that the respective gear ratios γt can be maintained.

The hybrid control unit 134 selectively establishes the EV traveling mode or the HV traveling mode as the traveling mode according to the traveling state. For example, the hybrid control unit 134 establishes the EV travel mode when the required drive power Prdem is in the EV travel region smaller than the predetermined travel region switching threshold value, while the required drive power Prdem is the travel region. When the vehicle is in the HV traveling region that is equal to or greater than the switching threshold value, the HV traveling mode is established. The alternate long and short dash line A in FIG. 6 is a boundary line between the HV traveling region and the EV traveling region for switching between the HV traveling mode and the EV traveling mode. The predetermined relationship having a boundary line as shown by the alternate long and short dash line A in FIG. 6 is an example of a traveling mode switching map composed of two-dimensional coordinates with the vehicle speed Vv and the required driving force Frdem as variables. In FIG. 6, for convenience, this travel mode switching map is shown together with the AT gear shift map.

When the EV drive mode is established, the hybrid control unit 134 is a four-wheel drive vehicle in a single drive EV drive by the second rotary machine MG2 if the required drive power Prdem can be realized only by the second rotary machine MG2. Run 10 On the other hand, when the EV drive mode is established, the hybrid control unit 134 travels the four-wheel drive vehicle 10 in the two-drive EV drive if the required drive power Prdem cannot be realized only by the second rotary machine MG2. Let me. Even when the required drive power Prdem can be realized only by the second rotary machine MG2, the hybrid control unit 134 uses the first rotary machine MG1 and the second rotary machine MG2 together rather than using only the second rotary machine MG2. If it is more efficient, the four-wheel drive vehicle 10 may be driven by the double-drive EV running.

The hybrid control unit 134 needs to warm up the engine 12 or when the charge state value SOC of the battery 24 is less than a predetermined engine start threshold value even when the required drive power Prdem is in the EV traveling region. In some cases, the HV driving mode is established. The engine start threshold value is a predetermined start determination value for determining that the charge state value SOC needs to automatically start the engine 12 to charge the battery 24.

The hybrid control unit 134 functionally includes a start control means, that is, a start control unit 134c, which performs engine start control to start the engine 12 when a predetermined start condition RMst is satisfied. The predetermined start condition RMst is that, for example, when the HV driving mode is established when the operation of the engine 12 is stopped, the four-wheel drive vehicle 10 is stopped while the engine 12 is operating in the HV driving mode. This is the case when the engine 12 is temporarily stopped by the known idling stop control. When the engine start control unit 134c performs engine start control, for example, when the engine rotation speed Ne becomes equal to or higher than a predetermined ignitable rotation speed that can be ignited while increasing the engine rotation speed Ne by the first rotary machine MG1. The engine 12 is started by supplying fuel to the engine 12 and igniting the engine 12. That is, the start control unit 134c starts the engine 12 by cranking the engine 12 by the first rotary machine MG1.

The hybrid control unit 134 functionally includes a stop control means, that is, a stop control unit 134d, which controls the engine to stop the engine 12 when the predetermined stop condition RMsp is satisfied. The predetermined stop condition RMsp is, for example, when the EV driving mode is established while the engine 12 is being driven, the four-wheel drive vehicle 10 is stopped when the engine 12 is being driven in the HV driving mode, so that the vehicle is idling. For example, when performing stop control. The stop control unit 134d stops the fuel supply to the engine 12 when the engine stop control is performed. At this time, the stop control unit 134d controls the MG1 torque Tg so as to apply a torque for reducing the engine rotation speed Ne to the engine 12, for example, in order to quickly reduce the engine rotation speed Ne and stop the rotation of the engine 12. You may.

The four-wheel drive control unit 136 performs a drive force distribution control CTx that adjusts the rear wheel side distribution rate Xr. The four-wheel drive control unit 136 sets a target value of the rear wheel side distribution ratio Xr according to the running state of the four-wheel drive vehicle 10 determined from the output rotation speed sensor 104, the G sensor 118, and the like, and sets the front wheel drive clutch. The electric motor control command signal Sw for controlling the electric motor 86 is output so as to adjust the rear wheel side distribution rate Xr to the target value by adjusting the torque capacity of 70.

For example, when traveling straight, the four-wheel drive control unit 136 controls the rear wheel side distribution ratio Xr to 1.0 (that is, the front and rear wheel drive force distribution is 0: 100) by releasing the front wheel drive clutch 70. do. Further, the four-wheel drive control unit 136 calculates the target yaw angular velocity Vyawtgt based on the steering angle θsw during turning and the vehicle speed Vv, etc., and the yaw angular velocity Vyaw detected at any time by the yaw rate sensor 122 becomes the target yaw angular velocity Vyawtgt. The rear wheel side distribution rate Xr is adjusted so as to follow.

When the four-wheel drive vehicle 10 is put into the four-wheel drive state, the four-wheel drive control unit 136 outputs an electric motor control command signal Sw for controlling the electric motor 86 so as to engage the front wheel drive clutch 70. At the same time, an electric actuator control command signal Sadd for controlling the electric actuator 102 so as to engage the disconnection clutch 43 is output. Further, when the four-wheel drive vehicle 10 is put into the two-wheel drive state, the four-wheel drive control unit 136 outputs an electric motor control command signal Sw for controlling the electric motor 86 so as to release the front wheel drive clutch 70, for example. At the same time, an electric actuator control command signal Sadd for controlling the electric actuator 102 so as to release the disconnection clutch 43 is output. In this way, the four-wheel drive control unit 136 engages the front-wheel drive clutch 70 and the disconnect clutch 43 together to put the four-wheel drive vehicle 10 into the four-wheel drive state. Further, the four-wheel drive control unit 136 releases both the front-wheel drive clutch 70 and the disconnect clutch 43 to put the four-wheel drive vehicle 10 into the two-wheel drive state in the disconnected state. Engaging the front wheel drive clutch 70 is slip engaging or fully engaging the front wheel drive clutch 70. As described above, the four-wheel drive vehicle 10 is a part-time four-wheel drive vehicle in which the two-wheel drive state and the four-wheel drive state can be switched according to the traveling state. For example, during the transition in which the four-wheel drive vehicle 10 is switched between the four-wheel drive state and the two-wheel drive state in the disconnect state, the state of waiting for the switch to the four-wheel drive state and the state of switching to the four-wheel drive state can be performed. When predicted, the four-wheel drive vehicle 10 is in a two-wheel drive state in which the disconnection clutch 43 is engaged.

The braking force control unit 138 calculates the target deceleration based on, for example, the vehicle speed Vv, the slope of the downhill road, the braking operation by the driver (for example, the braking operation amount Bra, the increasing speed of the braking operation amount Bra), and is predetermined. The required braking force Bdem for the four-wheel drive vehicle 10 for achieving the target deceleration is set by using the above relationship. The braking force control unit 138 generates the braking force of the four-wheel drive vehicle 10 so that the required braking force Bdem can be obtained during the deceleration traveling of the four-wheel drive vehicle 10.

The braking force of the four-wheel drive vehicle 10 is generated by, for example, a braking force by regenerative control by the second rotary machine MG2, that is, a regenerative braking force, a braking force by the wheel brake 101, or the like. The braking force of the four-wheel drive vehicle 10 is preferentially generated by the regenerative braking force, for example, from the viewpoint of improving energy efficiency. The braking force control unit 138 outputs a command to execute the regenerative control by the second rotary machine MG2 to the hybrid control unit 134 so that the regenerative torque required for the regenerative braking force can be obtained. In the regenerative control by the second rotary machine MG2, the second rotary machine MG2 is rotationally driven by the driven torque input from the wheels 14 and 16 to operate as a generator, and the generated power is transferred to the battery 24 via the inverter 22. It is a control to charge. As described above, the four-wheel drive vehicle 10 is a vehicle having a driving force source including at least a second rotating machine MG2 which is a rotating machine capable of performing regenerative control.

For example, when the required braking force Bdem is relatively small, the braking force control unit 138 realizes the required braking force Bdem exclusively by the regenerative braking force. For example, when the required braking force Bdem is relatively large, the braking force control unit 138 realizes the required braking force Bdem by adding the braking force of the wheel brake 101 to the regenerative braking force. For example, immediately before the four-wheel drive vehicle 10 stops, the braking force control unit 138 replaces the regenerative braking force with the braking force of the wheel brake 101 to realize the required braking force Bdem. The braking force control unit 138 outputs a brake control command signal Sb for obtaining the braking force by the wheel brake 101 required to realize the required braking force Bdem to the wheel brake device 100.

Further, the braking force control unit 138 determines the running stability of the four-wheel drive vehicle 10 in addition to the normal braking force control that realizes the braking force of the four-wheel drive vehicle 10 in response to the braking operation by the driver as described above. The braking force control for attitude control that realizes the braking force of the four-wheel drive vehicle 10 for executing the secured vehicle attitude control is performed. The vehicle attitude control is a known control for stabilizing the four-wheel drive vehicle 10, for example, a control for operating the ABS function, a braking force distribution control, a control for operating the brake assist function, a control for operating the TRC function, and a skid suppression. Control, control to activate the automatic braking function, etc. The braking force control unit 138 outputs a brake control command signal Sb for obtaining the braking force by the wheel brake 101 required for realizing the vehicle attitude control to the wheel brake device 100.

Here, when the four-wheel drive vehicle 10 is decelerated, the braking force associated with the regenerative control of the wheels 14 and 16 is limited so that the wheels 14 and 16 do not slip due to the regenerative control by the second rotary machine MG2. .. Therefore, when the four-wheel drive vehicle 10 is decelerated, the braking force that can be realized by the regenerative control by the second rotating machine MG2 of the required braking force Bdem is four that the wheels 14 and 16 can handle the braking force. The wheel drive state is more likely to be larger than the two-wheel drive state. Therefore, when the four-wheel drive vehicle 10 is decelerated, the energy obtained by the regenerative control by the second rotary machine MG2 is more likely to be larger in the four-wheel drive state than in the two-wheel drive state. Therefore, the braking force control unit 138 regenerates control by the second rotary machine MG2 in the four-wheel drive state so as to realize a part or all of the required braking force Bdem for the four-wheel drive vehicle 10 when the four-wheel drive vehicle 10 is decelerated. To execute.

By the way, in the four-wheel drive vehicle 10, in the four-wheel drive state, unlike the two-wheel drive state in the disconnect state, energy loss occurs due to the rotation of the front wheel transmission member PT. Therefore, when the four-wheel drive vehicle 10 is decelerated, there is room for improvement in improving energy efficiency by simply executing the regenerative control by the second rotary machine MG2 in the four-wheel drive state.

Therefore, when the braking force control unit 138 executes the regenerative control by the second rotary machine MG2, the amount of energy recovered in the four-wheel drive state is larger than that in the two-wheel drive state even when the energy loss is taken into consideration. The regeneration control is executed in the four-wheel drive state. On the other hand, the braking force control unit 138 disconnects when the energy recovery amount is not larger in the four-wheel drive state than in the two-wheel drive state when the regenerative control by the second rotary machine MG2 is executed, considering the energy loss. Regenerative control is executed in the two-wheel drive state of the state.

The electronic control device 130 further provides a state determination means, that is, a state determination, in order to realize a four-wheel drive vehicle 10 capable of appropriately improving energy efficiency when executing regenerative control by the second rotary machine MG2 during vehicle deceleration. The unit 140 is provided.

The state determination unit 140 determines whether or not the regenerative control by the second rotary machine MG2 is executed by the braking force control unit 138 when the four-wheel drive vehicle 10 is decelerated. For example, the state determination unit 140 has a charge state value SOC of the battery 24 in a situation where the required braking force Bdem is zero or substantially zero, and in a situation where the regenerative braking force is replaced by the braking force by the wheel brake 101. Is more than a predetermined charge-free state value that does not require charging, and the braking force control unit 138 determines that the regenerative control by the second rotary machine MG2 is not executed when the four-wheel drive vehicle 10 is decelerated. do.

When the state determination unit 140 determines that the regenerative control by the second rotary machine MG2 is executed by the braking force control unit 138, the state determination unit 140 determines whether or not the energy balance InEx is a plus exceeding zero. That is, when the state determination unit 140 determines that the regenerative control by the second rotary machine MG2 is executed by the braking force control unit 138, the energy balance InEx is set to a predetermined threshold value TS (= 0). Determine if it is greater than. The energy balance InEx is increased in the four-wheel drive state as compared to the two-wheel drive state in the disconnect state. It is a value obtained by subtracting the amount of energy loss caused by being forced to lose. The state determination unit 140 calculates the energy acquisition amount Acqu based on, for example, the required braking force Bdem, the braking force associated with the predetermined regenerative control for preventing the wheels 14 and 16 from slipping according to the wheel speed Nr, and the like. do. Further, the state determination unit 140 calculates the energy loss amount Loss based on the wheel speed Nr or the like by using, for example, a predetermined map or a calculation formula. The state determination unit 140 calculates the energy balance InEx (= Acqu-Loss) using the calculated energy acquisition amount Acqu and energy loss amount Loss.

The braking force control unit 138 is second when it is determined by the state determination unit 140 that the regenerative control by the second rotating machine MG2 is executed when the four-wheel drive vehicle 10 is decelerated, that is, when the four-wheel drive vehicle 10 is decelerated. When the state determination unit 140 determines that the energy balance InEx is positive when the regenerative control is executed by the rotary machine MG2, the regenerative control is executed in the four-wheel drive state. When the four-wheel drive vehicle 10 is currently in the two-wheel drive state, the braking force control unit 138 outputs a command to switch the four-wheel drive vehicle 10 to the four-wheel drive state to the four-wheel drive control unit 136. Executing the regenerative control in the four-wheel drive state means that the regenerative control is also executed by the driven torque input from the front wheels 14 as the connected state in which the front wheel drive clutch 70 and the disconnect clutch 43 are engaged together. That's what it means.

On the other hand, when the braking force control unit 138 determines that the energy balance InEx is zero or less by the state determination unit 140 when the regenerative control by the second rotating machine MG2 is executed when the four-wheel drive vehicle 10 is decelerated. , The regenerative control is executed in the two-wheel drive state in the disconnect state instead of the four-wheel drive state. When the four-wheel drive vehicle 10 is currently in a four-wheel drive state or a two-wheel drive state that is not in the disconnect state, the braking force control unit 138 issues a command to switch the four-wheel drive vehicle 10 to the two-wheel drive state in the disconnect state. It is output to the four-wheel drive control unit 136. Executing the regenerative control in the two-wheel drive state in the disconnected state means that the regenerative control is not executed depending on the driven torque input from the front wheel 14 as the disconnected state.

FIG. 7 is a flowchart illustrating a main part of the control operation of the electronic control device 130, and is a four-wheel drive capable of appropriately improving energy efficiency when performing regenerative control by the second rotary machine MG2 during vehicle deceleration. It is a flowchart explaining the control operation for realizing a vehicle 10, and is executed repeatedly, for example.

In FIG. 7, first, in step S10 corresponding to the function of the state determination unit 140 (hereinafter, step is omitted), whether or not regenerative control by the second rotary machine MG2 is executed when the four-wheel drive vehicle 10 is decelerated. Is determined. If the judgment of S10 is denied, this routine is terminated. If the determination in S10 is affirmed, it is determined in S20 corresponding to the function of the state determination unit 140 whether or not the energy balance InEx is positive. If the determination of S20 is affirmed, the regenerative control by the second rotary machine MG2 is executed in the four-wheel drive state in S30 corresponding to the function of the braking force control unit 138. On the other hand, if the determination in S20 is denied, the regenerative control by the second rotary machine MG2 is executed in the two-wheel drive state in the disconnected state in S40 corresponding to the function of the braking force control unit 138.

As described above, according to the present embodiment, the regenerative control by the second rotary machine MG2 is executed in the four-wheel drive state so as to realize a part or all of the required braking force Bdem when the four-wheel drive vehicle 10 is decelerated. To. On the other hand, when the energy balance InEx is zero or less when the regenerative control is executed by the second rotary machine MG2, the regenerative control is executed in the two-wheel drive state in the disconnected state instead of the four-wheel drive state. As a result, not only the regenerative control is executed in the four-wheel drive state, but also the regenerative control is executed in the two-wheel drive state in consideration of the energy loss in the four-wheel drive state. Therefore, the energy efficiency can be appropriately improved when the regenerative control by the second rotary machine MG2 is executed when the vehicle is decelerated.

Next, another embodiment of the present invention will be described. In the following description, the same reference numerals are given to the parts common to each other in the examples, and the description thereof will be omitted.

In the above-described first embodiment, when the regenerative control by the second rotary machine MG2 is not executed when the four-wheel drive vehicle 10 is decelerated, for example, if the four-wheel drive vehicle 10 is currently in the two-wheel drive state, the two-wheel drive state is changed. It is maintained, and if it is a four-wheel drive state, the four-wheel drive state is maintained. On the other hand, for example, from the viewpoint of improving energy efficiency, it is better to increase the mileage of the four-wheel drive vehicle 10 during deceleration. As described above, in the four-wheel drive vehicle 10, the energy loss amount Loss is larger in the four-wheel drive state than in the two-wheel drive state in the disconnect state.

Therefore, when the state determination unit 140 determines that the regenerative control by the second rotary machine MG2 is not executed when the four-wheel drive vehicle 10 is decelerated, the four-wheel drive control unit 136 drives the four-wheel drive vehicle 10 to four wheels. In the case of a two-wheel drive state that is not in the disconnected state or in the disconnected state, the four-wheel drive vehicle 10 is switched to the two-wheel drive state in the disconnected state. As described above, when the electronic control device 130 does not execute the regenerative control by the second rotating machine MG2 when the four-wheel drive vehicle 10 is decelerated, the electronic control device 130 decelerates and travels in the two-wheel drive state in the disconnected state. Such an embodiment is particularly useful when the regenerative control by the second rotary machine MG2 is not executed because the required braking force Bdem is zero or substantially zero.

FIG. 8 is a flowchart illustrating a main part of the control operation of the electronic control device 130, and is a four-wheel drive capable of appropriately improving energy efficiency when performing regenerative control by the second rotary machine MG2 during vehicle deceleration. It is a flowchart explaining the control operation for realizing a vehicle 10, and is executed repeatedly, for example. FIG. 8 is an example different from FIG. 7 of the above-mentioned Example 1. The parts of FIG. 8 that differ from FIG. 7 will be described below.

In FIG. 8, when the determination in S10 is denied, the four-wheel drive vehicle 10 is in a two-wheel drive state in a disconnected state in S50 corresponding to the function of the four-wheel drive control unit 136.

As described above, according to this embodiment, the same effect as that of the above-mentioned Example 1 can be obtained.

Further, according to the present embodiment, when the regenerative control by the second rotary machine MG2 is not executed when the four-wheel drive vehicle 10 is decelerated, the vehicle is decelerated and traveled in the two-wheel drive state in the disconnected state, so that the four-wheel drive state is achieved. The distance of deceleration running is longer than that of deceleration running in. As a result, energy efficiency can be improved even when the regeneration control by the second rotating machine MG2 is not executed when the four-wheel drive vehicle 10 is decelerated.

In the first embodiment described above, when the energy balance InEx exceeds zero when the regenerative control is executed by the second rotary machine MG2 when the four-wheel drive vehicle 10 is decelerated, the regenerative control is executed in the four-wheel drive state. did. When the operating state DCv of the four-wheel drive vehicle 10 is in the predetermined operating state DCvf in which the improvement of driving performance is more important than the improvement of energy efficiency, the driving force distribution control is performed even if the energy balance InEx is negative to some extent. It is better to execute the regenerative control in the four-wheel drive state of the four-wheel drive vehicle 10 in which the vehicle controllability is easily ensured by CTx.

Therefore, in the electronic control device 130, when the regenerative control by the second rotary machine MG2 is executed when the four-wheel drive vehicle 10 is decelerated, the energy balance InEx exceeds a predetermined threshold TS (≦ 0) to a value of zero or less. In that case, the regenerative control is executed in the four-wheel drive state, while when the energy balance InEx is equal to or less than the threshold TS, the regenerative control is executed in the two-wheel drive state in the disconnected state instead of the four-wheel drive state. .. In the first embodiment described above, it can be seen that the threshold value TS is set to zero regardless of whether or not the operating state DCv of the four-wheel drive vehicle 10 is in the predetermined operating state DCvf.

When the state determination unit 140 determines that the regenerative control by the second rotary machine MG2 is executed by the braking force control unit 138, the state determination unit 140 sets the threshold value TS according to the operating state DCv of the four-wheel drive vehicle 10. For example, when the operating state DCv of the four-wheel drive vehicle 10 is in the predetermined operating state DCvf, the state determination unit 140 has a threshold TS as compared with the case where the operating state DCv of the four-wheel drive vehicle 10 is not in the predetermined operating state DCvf. To a small value. The threshold value TS set when the vehicle is not in the predetermined operating state DCvf is, for example, a predetermined value for appropriately improving energy efficiency when performing regenerative control by the second rotary machine MG2 during vehicle deceleration, for example, zero. Or it is a negative value near zero. The threshold value TS set when the predetermined operating state DCvf is set is predetermined in order to achieve both improvement of energy efficiency and improvement of driving performance when performing regenerative control by the second rotary machine MG2, for example, when the vehicle is decelerating. It is a negative value that is somewhat smaller than zero, for example.

The predetermined operating state DCvf is, for example, an operating state DCv in which the driving performance is more likely to deteriorate in the two-wheel drive state than in the four-wheel drive state, and it is necessary to secure the vehicle controllability by the driving force distribution control CTx. That is, the operating state DCv in which it is necessary to suppress the change in vehicle attitude by the driving force distribution control CTx. Specifically, the predetermined driving state DCvf is the driving state DCv in which the four-wheel drive vehicle 10 is turning, and / or the driving state DCv in which the driving mode of the four-wheel drive vehicle 10 is the power mode. / Or, the driving state DCv in which the traveling mode of the four-wheel drive vehicle 10 is set to the manual mode, and / or the required braking force Bdem is set to a predetermined braking force Bdemf or more such that the required braking amount for the four-wheel drive vehicle 10 is large. The operating state DCv and / or the operating state DCv and / or the vehicle speed Vv in which the braking operation amount Bra is equal to or greater than the predetermined braking operation amount Braf such that the driver's braking operation is large such as a sudden braking operation. In the driving state DCv where the vehicle speed is Vvf or higher so that the vehicle decelerates at a high vehicle speed, and / or in the driving state DCv where the outside temperature THair is lower than the predetermined temperature THairf where there is a high possibility of road surface freezing. be. During the turning running of the four-wheel drive vehicle 10 described above, the turning running may be performed in order to distinguish between the turning running and the straight running, or the yaw angular velocity Vyaw is a predetermined angular velocity Vyawf such that the driver's steering operation is large. It may be limited to the above-mentioned turning running, or may be limited to the turning running in which the steering angle θsw is equal to or larger than the predetermined angle θswf such that the driver's steering operation is large. The predetermined braking force Bdemf, the predetermined braking operation amount Braf, the predetermined vehicle speed Vvf, the predetermined temperature THairf, the predetermined angular velocity Vyawf, and the predetermined angle θswf are each predetermined operating states for determining that they are the predetermined operating states DCvf. It is a judgment value.

When the state determination unit 140 determines that the regenerative control by the second rotary machine MG2 is executed by the braking force control unit 138, the state determination unit 140 determines whether or not the energy balance InEx is larger than the threshold value TS set.

When the state determination unit 140 determines that the energy balance InEx is larger than the threshold value TS when the second rotating machine MG2 executes the regenerative control when the four-wheel drive vehicle 10 is decelerated, the braking force control unit 138 is set to four. Regenerative control is executed in the wheel drive state. On the other hand, when the braking force control unit 138 determines that the energy balance InEx is equal to or less than the threshold TS when the state determination unit 140 executes the regenerative control by the second rotating machine MG2 when the four-wheel drive vehicle 10 is decelerated. Performs regenerative control in the two-wheel drive state in the disconnect state instead of the four-wheel drive state.

FIG. 9 is a flowchart illustrating a main part of the control operation of the electronic control device 130, and is a four-wheel drive capable of appropriately improving energy efficiency when performing regenerative control by the second rotary machine MG2 during vehicle deceleration. It is a flowchart explaining the control operation for realizing a vehicle 10, and is executed repeatedly, for example. FIG. 9 is an example different from FIG. 7 of the above-mentioned Example 1. The parts of FIG. 9 that differ from FIG. 7 will be described below.

In FIG. 9, when the determination in S10 is affirmed, the threshold value TS (≦ 0) corresponding to the driving state DCv of the four-wheel drive vehicle 10 is set in S15 corresponding to the function of the state determination unit 140. For example, when the operating state DCv of the four-wheel drive vehicle 10 is in the predetermined operating state DCvf, the threshold value TS is set to a smaller value than when it is not in the predetermined operating state DCvf. Next, in S25 corresponding to the function of the state determination unit 140, it is determined whether or not the energy balance InEx is larger than the threshold value TS. If the determination of S25 is affirmed, the S30 is executed, while if the determination of S25 is denied, the S40 is executed.

As described above, according to this embodiment, the same effect as that of the above-mentioned Example 1 can be obtained.

Further, according to the present embodiment, when the operating state DCv of the four-wheel drive vehicle 10 is in the predetermined operating state DCvf, the threshold value is compared with the case where the operating state DCv of the four-wheel drive vehicle 10 is not in the predetermined operating state DCvf. Since the TS is set to a small value, it is easy to decelerate the vehicle in a four-wheel drive state in a situation where improvement in driving performance is important. As a result, it is possible to achieve both improvement in energy efficiency and improvement in operating performance.

Further, according to the present embodiment, the predetermined driving state DCvf is the driving state DCv in which the four-wheel drive vehicle 10 is turning, and the driving state DCv in which the driving mode of the four-wheel drive vehicle 10 is the power mode. The driving state DCv in which the traveling mode of the wheel drive vehicle 10 is set to the manual mode, the driving state DCv in which the required braking force Bdem is set to the predetermined braking force Bdemf or more, and the driving state in which the braking operation amount Bra is set to the predetermined braking operation amount Braf or more. Since the DCv, the operating state DCv in which the vehicle speed Vv is equal to or higher than the predetermined vehicle speed Vvf, and / or the operating state DCv in which the outside temperature THair is less than the predetermined temperature THairf, the manual mode in the power mode in the turning state. Possibility of high vehicle speed and / or road surface freezing in a situation where a large braking force is required for a four-wheel drive vehicle, in a situation where a sudden braking operation is performed. It is possible to improve the energy efficiency while suppressing the deterioration of the driving performance during deceleration running in the situation where the speed is high.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is also applicable to other aspects.

For example, in the above-described embodiment, if the determination of S10 is denied in the flowchart of FIG. 9, the S50 of FIG. 8 may be executed, and the flowcharts of FIGS. 7, 8 and 9 are appropriately modified. be able to.

Further, in the above-described embodiment, the four-wheel drive vehicle 10 is a four-wheel drive vehicle based on an FR type vehicle, and also drives the engine 12, the first rotary machine MG1, and the second rotary machine MG2. It is a hybrid vehicle as a source, and is a four-wheel drive vehicle provided with an automatic transmission 28 having a continuously variable transmission unit 44 and a stepped speed change unit 46 in series, but the present invention is not limited to this embodiment. For example, a four-wheel drive vehicle based on an FF (front engine / front drive) type vehicle, or a parallel hybrid vehicle in which the driving force from the engine and the rotating machine is transmitted to the drive wheels, or engine power. A series of hybrid vehicles in which the power generated by the generator driven by the vehicle and / or the driving force from the rotating machine driven by the battery power is transmitted to the drive wheels, or electricity using only the rotating machine as the driving force source. The present invention can be applied even to an automobile or the like. Alternatively, as the automatic transmission, a known planetary gear type automatic transmission, a synchronous meshing parallel two-axis automatic transmission including a known DCT (Dual Clutch Transmission), a known belt type continuously variable transmission, or a known electric The present invention can be applied even to a four-wheel drive vehicle equipped with a continuously variable transmission or the like. Alternatively, the series hybrid vehicle as described above may not be equipped with, for example, an automatic transmission.

In the case of a four-wheel drive vehicle based on an FF type vehicle, the front wheels are the main drive wheels, the rear wheels are the auxiliary drive wheels, and the front wheel side distribution ratio Xf is the main side distribution ratio. In the series hybrid vehicle as described above, the engine is used as a driving force source that indirectly outputs the driving force through the conversion between power and electric power. However, in a series hybrid vehicle, if a clutch that mechanically connects the engine to the drive wheels so that power can be transmitted is provided, the engine is used as a drive force source that directly outputs the drive force. Is possible. In short, the main drive wheel that transmits the drive force from at least the drive force source including the rotary machine, the transmission member that transmits a part of the drive force distributed during the four-wheel drive drive to the sub drive wheel, and the drive force. A first clutch capable of connecting and disconnecting power transmission between a source and a transmission member, a second clutch capable of connecting and disconnecting power transmission between a transmission member and an auxiliary drive wheel, and a control device are provided. The present invention can be applied to any four-wheel drive vehicle.

Further, in the above-described embodiment, the piston 84 of the front wheel drive clutch 70 constituting the transfer 30 is moved to the friction engagement element 82 side via the cam mechanism 90 when the electric motor 86 rotates, and is frictionally engaged. It was configured to press the element 82, but is not limited to this aspect. For example, when the electric motor 86 rotates, the piston 84 may be configured to press the friction engagement element 82 via a ball screw or the like that converts the rotational motion into a linear motion. Alternatively, the piston 84 may be driven by a hydraulic actuator.

Further, in the above-described embodiment, the front wheel drive clutch 70 is a multi-plate wet clutch, and the disconnect clutch 43 is a meshing type clutch, but the present invention is not limited to this mode. For example, the front wheel drive clutch 70 may be a meshing type clutch or the like, and the disconnect clutch 43 may be a friction clutch or a known electronically controlled coupling. In short, the present invention is a four-wheel drive vehicle provided with two clutches capable of preventing a transmission member such as a front wheel transmission member PT from rotating in a two-wheel drive state of a four-wheel drive vehicle. Can be applied.

It should be noted that the above is only one embodiment, and the present invention can be carried out in a mode in which various changes and improvements are made based on the knowledge of those skilled in the art.

10: Four-wheel drive vehicle 14 (14L, 14R): Front wheels (secondary drive wheels)
16 (16L, 16R): Rear wheels (main drive wheels)
43: Disconnect clutch (second clutch)
70: Front wheel drive clutch (first clutch)
130: Electronic control device (control device)
MG2: 2nd rotating machine (driving force source, rotating machine)
PT: Front wheel transmission member (transmission member)

Claims (10)

A driving force source including at least a rotating machine, a main driving wheel to which the driving force from the driving force source is transmitted, an auxiliary driving wheel to which a part of the driving force is distributed during four-wheel drive traveling, and the four wheels. A transmission member that transmits a part of the driving force distributed during driving to the sub-driving wheel, a first clutch capable of connecting and disconnecting power transmission between the driving force source and the transmission member, and the above. A four-wheeled vehicle including a second clutch capable of connecting and disconnecting power transmission between a transmission member and the auxiliary drive wheel, and a control device for controlling the rotary machine, the first clutch, and the second clutch. It ’s a driving vehicle,
The control device engages the first clutch and the second clutch together to bring the four-wheel drive vehicle into a four-wheel drive state, and releases both the first clutch and the second clutch to disconnect. It is a two-wheel drive state, which is a state.
While the control device executes regenerative control by the rotating machine in the four-wheel drive state so as to realize a part or all of the required braking force for the four-wheel drive vehicle when the four-wheel drive vehicle decelerates. When the regenerative control is executed, the transmission member is rotated in the four-wheel drive state from the amount of energy acquired by the regenerative control, which is increased in the four-wheel drive state as compared with the two-wheel drive state in the disconnect state. When the energy balance obtained by subtracting the amount of energy loss due to the above is less than or equal to a predetermined threshold value of zero or less, the regeneration control is performed in the two-wheel drive state of the disconnect state instead of the four-wheel drive state. A four-wheel drive vehicle characterized by running. The four-wheel drive vehicle according to claim 1, wherein the control device is in a two-wheel drive state in the disconnected state when the regenerative control is not executed when the four-wheel drive vehicle is decelerated. In the control device, when the operating state of the four-wheel drive vehicle is in a predetermined operating state in which the improvement of driving performance is more important than the improvement of energy efficiency, the operating state of the four-wheel drive vehicle is the predetermined operation. The four-wheel drive vehicle according to claim 1 or 2, wherein the threshold value is set to a smaller value than in the case where the state is not present. The four-wheel drive vehicle according to claim 3, wherein the predetermined driving state is a driving state in which the four-wheel drive vehicle is in a turning state. The four-wheel drive vehicle according to claim 3 or 4, wherein the predetermined driving state is a driving state in which the traveling mode of the four-wheel drive vehicle is set to an output-oriented mode. The four-wheel drive vehicle according to any one of claims 3 to 5, wherein the predetermined driving state is a driving state in which the traveling mode of the four-wheel drive vehicle is set to the manual mode. The four-wheel drive vehicle according to any one of claims 3 to 6, wherein the predetermined operating state is an operating state in which the required braking force is equal to or higher than the predetermined braking force. The four-wheel drive vehicle according to any one of claims 3 to 7, wherein the predetermined operating state is an operating state in which the braking operation amount is equal to or greater than the predetermined braking operation amount. The four-wheel drive vehicle according to any one of claims 3 to 8, wherein the predetermined driving state is a driving state in which the vehicle speed is set to a predetermined vehicle speed or higher. The four-wheel drive vehicle according to any one of claims 3 to 9, wherein the predetermined operating state is an operating state in which the outside air temperature is lower than the predetermined temperature.

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