JP6900860B2 - Vehicle control device - Google Patents

Description

The present invention includes a first differential mechanism in which an engine is connected so as to be able to transmit power, a second differential mechanism in which the differential state is controlled by controlling the operating state of the first rotating machine, and a drive wheel. The present invention relates to a vehicle control device including a second rotating machine connected to an output rotating member to be connected so as to be able to transmit power.

According to Patent Document 1, if the tire is locked by the brake when the tire slips, and then the brake is released and then gripped, the wheel speed may suddenly increase and the input shaft rotation speed may become excessive depending on the gear ratio. In that case, a technique for preventing over-rotation of the input shaft rotation speed by allowing shifting to a high-speed stage when gripped is described.

Japanese Unexamined Patent Publication No. 2017-48883 International Publication No. 2013/11594

By the way, Patent Document 2 describes a first differential mechanism having a first rotating element, a second rotating element, and a third rotating element, in which an engine is connected so as to be able to transmit power, and a fourth rotating element and a fifth. Power is supplied to the second differential mechanism, which has a rotating element and a sixth rotating element and whose differential state is controlled by controlling the operating state of the first rotating machine, and the output rotating member connected to the drive wheels. Vehicles with a second rotating machine connected so as to be transmissible are described. Here, in the vehicle described in Patent Document 2, by further adding an engaging device for changing the connection state between the first differential mechanism and the second differential mechanism, the power of the second differential mechanism alone can be obtained. It is conceivable to form a traveling mode that achieves a power division ratio different from the division ratio. In such a vehicle, depending on the traveling mode, there is also a traveling mode in which the rotation speed change of the first rotating machine is large with respect to the change in the wheel speed, and when slip occurs during traveling in such a traveling mode, the first rotating machine May become over-rotated. Therefore, there is room for consideration regarding mode selection when slip occurs.

The present invention has been made against the background of the above circumstances, and an object of the present invention is to control the operating state of the first differential mechanism and the first rotating machine in which the engines are connected so as to be able to transmit power. In a vehicle equipped with a second differential mechanism whose differential state is controlled by this and a second rotary machine which is connected to an output rotating member connected to a drive wheel so as to be able to transmit power, a grip after the vehicle slips. An object of the present invention is to provide a control device for suppressing over-rotation of the first rotating machine at times.

The gist of the first invention is (a) a first differential mechanism having a first rotating element, a second rotating element, and a third rotating element, in which an engine is connected so as to be able to transmit power, and a fourth. A second differential mechanism having a rotating element, a fifth rotating element, and a sixth rotating element and whose differential state is controlled by controlling the operating state of the first rotating machine is connected to the drive wheels. It is a control device of a vehicle provided with a second rotating machine connected to an output rotating member so as to be able to transmit power. (B) The first rotating element is connected to the engine so as to be able to transmit power. (C) The third rotating element is connected to the sixth rotating element, (d) the fourth rotating element is connected so that the first rotating machine can transmit power, and (e) the above. The fifth rotating element is connected to the output rotating member, and (f) the vehicle is a rotating element of any two of the first rotating element, the second rotating element, and the third rotating element. A first engaging device for connecting the second rotating element, and a second engaging device for connecting the second rotating element with any one of the fourth rotating element and the fifth rotating element. (G) The differential state of the second differential mechanism is controlled in a state where one of the first engaging device and the second engaging device is engaged. The first traveling mode in which the torque of the engine is mechanically transmitted to the fifth rotating element and the engagement device different from the one engagement device of the first engagement device and the second engagement device. A second traveling mode in which the differential state of the second differential mechanism is controlled in a state where the devices are engaged and the torque of the engine is mechanically transmitted to the fifth rotating element, and the first engaging device. And by engaging the second engaging device, each rotating element of the first differential mechanism and the second differential mechanism is integrally rotated, and the torque of the engine is transferred to the fifth rotating element. a third drive mode that is mechanically transmitted, the, (h) during running in the first running mode or the second running mode, the slip of the driving wheels is predicted, or, the drive wheel When it is determined that the slip has occurred, the control unit is provided for switching to the third traveling mode in which the change in the rotational speed of the first rotating machine with respect to the rotational speed of the drive wheels is small.

According to the vehicle control device of the first invention, when the driving wheels are predicted to slip or the driving wheels are determined to slip while traveling in the first traveling mode or the second traveling mode, the vehicle is driven. Since the mode can be switched to the third traveling mode in which the change in the rotation speed of the first rotating machine with respect to the rotation speed of the wheels is small, it is possible to suppress the over-rotation of the first rotating machine after the grip of the drive wheels.

It is a figure explaining the schematic structure of each part which concerns on the traveling of the vehicle to which this invention is applied, and is the figure explaining the main part of the control system for controlling each part. It is a figure which shows an example of the hydraulic control circuit which controls the operating state of an engaging device. It is a figure which shows each operating state of each engaging device in each traveling mode. It is a collinear diagram in the single drive EV mode. It is a collinear diagram in the dual drive EV mode. It is a collinear diagram in the standby mode in the U / D input split. It is a collinear diagram in the standby mode in the O / D input split. It is a collinear diagram in the emblem combined mode in the U / D input split. It is a collinear diagram in the emblem combined mode in the O / D input split. It is a collinear diagram in the forward running in the U / DHV mode of the HV running mode. It is a collinear diagram in the forward running in the O / DHV mode of the HV running mode. It is a collinear diagram in the reverse running in the U / DHV mode of the HV running mode, and is the case of the engine reverse input. It is a collinear diagram in the reverse running in the U / DHV mode of the HV running mode, and is the case of the engine forward rotation input. It is a collinear diagram in the reverse running in the O / DHV mode of the HV running mode, and is the case of the engine forward rotation input. It is a collinear diagram in the fixed stage mode of the HV driving mode, and is a case of direct connection. It is a collinear diagram in the fixed stage mode of the HV driving mode, and is the case of the fixed output shaft. It is a figure which shows an example of the running mode switching map used for the switching control of engine running and motor running, and is the case of running in the state which holds the battery capacity. It is a figure which shows an example of the running mode switching map used for the switching control of engine running and motor running, and is the case of running while consuming the battery capacity. It is a collinear diagram which shows the rotation state immediately after the drive wheel slips while traveling in the O / DHV mode. It is a collinear diagram which shows the rotation state when a predetermined time elapses from the occurrence of slip. It is a collinear diagram which shows the rotation state after gripping of a drive wheel when the O / DHV mode is maintained. It is a collinear diagram which shows the rotation state at the time of switching from O / DHV mode to U / DHV mode. FIG. 5 is a collinear diagram showing a rotational state when the drive wheels are gripped from the rotational state shown in the collinear diagram of FIG. 22. It is a flowchart for demonstrating the main part of the control operation of the electronic control device of FIG. 1, that is, the control operation which suppresses the over-rotation of the MG1 rotation speed when the drive wheel slips while traveling in the O / DHV mode. It is a time chart which shows the control state at the time of switching to a U / DHV mode when a drive wheel slips while traveling in an O / DHV mode. It is a time chart which shows the control state at the time of switching to a direct connection fixed stage mode when a drive wheel slips while traveling in an O / DHV mode.

Hereinafter, examples of the present invention will be described in detail with reference to the drawings. In the following examples, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of each part are not necessarily drawn accurately.

FIG. 1 is a diagram for explaining a schematic configuration of each part related to traveling of the vehicle 10 to which the present invention is applied, and is a diagram for explaining a main part of a control system for controlling each part. In FIG. 1, the vehicle 10 is a hybrid vehicle including an engine 12, a first rotary machine MG1, a second rotary machine MG2, a power transmission device 14, and a drive wheel 16 which can be a power source for traveling. The engine 12 corresponds to the engine of the present invention.

The engine 12 is a known internal combustion engine such as a gasoline engine or a diesel engine that burns a predetermined fuel to output power. The engine torque Te of the engine 12 is controlled by controlling the throttle opening or the operating state such as the intake air amount, the fuel supply amount, and the ignition timing by the electronic control device 90 described later.

The first rotary machine MG1 and the second rotary machine MG2 are so-called motor generators having a function as an electric motor (motor) for generating drive torque and a function as a generator (generator). The first rotating machine MG1 and the second rotating machine MG2 are provided in the vehicle 10 as a power storage device that receives and receives electric power via a power control unit 50 provided in the vehicle 10 having an inverter unit, a smoothing capacitor, and the like. The output torque (power running torque or regenerative torque) of each of the first rotary machine MG1 and the second rotary machine MG2 is connected to the battery unit 52 and is controlled by the electronic control device 90 described later to control the power control unit 50. MG1 torque Tg and MG2 torque Tm are controlled.

The power transmission device 14 is provided in a power transmission path between the engine 12 and the drive wheels 16. The power transmission device 14 includes a first rotary machine MG1, a second rotary machine MG2, a first power transmission unit 20, a second power transmission unit 22, and the like in a case 18 which is a non-rotating member attached to a vehicle body. .. Further, the power transmission device 14 is a drive pinion via a propeller shaft 26 connected to an output shaft 24 which is an output rotating member of the first power transmission unit 20, a drive pinion 28 connected to the propeller shaft 26, and a differential ring gear 30. It includes a differential gear 32 that meshes with 28, a drive shaft 34 connected to the differential gear 32, and the like.

The first power transmission unit 20 is arranged coaxially with the input shaft 36 which is an input rotation member of the first power transmission unit 20 connected to the crankshaft of the engine 12, and the first differential mechanism 38, the first differential mechanism 38, is arranged. The two differential mechanism 40, the first rotary machine MG1, the clutch CL1, the brake BR1, the clutch CLc and the like are provided.

The first differential mechanism 38 supports the first sun gear S1, a plurality of pairs of first pinion gears P1a and P1b that mesh with each other, and the first pinion gears P1a and P1b so as to rotate and revolve. It is a known double pinion type planetary gear mechanism having a first ring gear R1 that meshes with the first sun gear S1 via the above, and functions as a differential mechanism that produces a differential action. The first differential mechanism 38 employs a double pinion type planetary gear mechanism in consideration of making the gear ratio ρ1 (the gear ratio ρ will be described later) appropriate, for example. Further, the second differential mechanism 40 meshes with the second sun gear S2 via the second carrier C2 and the second pinion gear P2 that support the second sun gear S2, the second pinion gear P2, and the second pinion gear P2 so as to rotate and revolve. It is a known single pinion type planetary gear mechanism having a second ring gear R2, and functions as a differential mechanism that produces a differential action.

In the first differential mechanism 38, the first carrier C1 is the first rotating element RE1 integrally connected to the input shaft 36 and the engine 12 is power-transmittedly connected via the input shaft 36. 1 Functions as an input rotating member of the differential mechanism 38. The first ring gear R1 is a second rotating element RE2 that is selectively connected to the case 18 via the brake BR1. The first sun gear S1 is a third rotating element RE3 connected to an input rotating member of the second differential mechanism 40 (that is, the second ring gear R2 of the second differential mechanism 40), and is an output of the first differential mechanism 38. Functions as a rotating member.

In the second differential mechanism 40, the second sun gear S2 is integrally connected to the rotor shaft 42 of the first rotating machine MG1, and serves as a reaction force element to which the first rotating machine MG1 is connected so as to be able to transmit power. This is the fourth rotating element RE4. The second carrier C2 is a fifth rotating element RE5 as an output element connected to the output shaft 24 (that is, provided so as to rotate integrally with the output shaft 24) and connected to the drive wheel 16. It functions as an output rotating member of the second differential mechanism 40. The second ring gear R2 is a sixth rotating element RE6 as an input element connected to an output rotating member of the first differential mechanism 38 (that is, the first sun gear S1 of the first differential mechanism 38), and is a second differential. It functions as an input rotating member of the mechanism 40.

The first carrier C1 and the first ring gear R1 are selectively connected via the clutch CL1. Further, the first ring gear R1 and the second carrier C2 are selectively connected via the clutch CLc. Therefore, the clutch CL1 is a first engaging device that selectively connects the first rotating element RE1 and the second rotating element RE2. Further, the clutch CLc is a second engaging device that selectively connects the second rotating element RE2 and the fifth rotating element RE5. Further, the brake BR1 is a third engaging device that selectively connects the second rotating element RE2 to the case 18. The clutch CL1, the brake BR1, and the clutch CLc are preferably wet friction engagement devices, and are multi-plate type hydraulic friction engagement devices whose engagement is controlled by a hydraulic actuator.

FIG. 2 shows an example of a main part of the hydraulic control circuit 60 provided in the vehicle 10 that controls the operating state (state of engagement, disengagement, etc.) of each engaging device (clutch CL1, brake BR1, clutch CLc). It is a figure which shows. In FIG. 2, the hydraulic control circuit 60 includes a primary regulator valve 62, linear solenoid valves SL1, SL2, SL3, and the like. The primary regulator valve 62 uses the oil pressure generated by the mechanical oil pump 64 (also referred to as MOP64) provided in the vehicle 10 as the main pressure, or the electric oil pump 66 (also referred to as EOP66) provided in the vehicle 10. ) Is used as the original pressure to regulate the line hydraulic pressure PL. The MOP 64 is connected to, for example, any rotating member of the power transmission device 14 (which also agrees with the rotating element) that rotates with the rotation of the engine 12, and supplies hydraulic pressure by being rotationally driven by the engine 12. The EOP66 is driven to rotate by a dedicated motor (not shown) controlled by an electronic control device 90, which will be described later, when the rotation of the engine 12 is stopped (for example, when the motor is running when the operation of the engine 12 is stopped). Supply. The linear solenoid valve SL1 regulates the engagement hydraulic pressure (also referred to as CL1 hydraulic pressure Pcl1) supplied to the clutch CL1 using the line hydraulic pressure PL as the original pressure. The linear solenoid valve SL2 regulates the engagement hydraulic pressure (also referred to as BR1 hydraulic pressure Pbr1) supplied to the brake BR1 using the line hydraulic pressure PL as the original pressure. The linear solenoid valve SL3 regulates the engagement hydraulic pressure (also referred to as CLc hydraulic pressure Pclc) supplied to the clutch CLc using the line hydraulic pressure PL as the original pressure. The linear solenoid valves SL1, SL2, and SL3 have basically the same configuration, and the electronic control device 90 independently excites, de-excites, and controls the current, and makes each of the hydraulic Pcl1, Pbr1, and Pclc independent. Adjust the pressure. The operating state of each engaging device (clutch CL1, brake BR1, clutch CLc) is switched according to the respective hydraulic pressures Pcl1, Pbr1, and Pclc supplied from the hydraulic control circuit 60.

Returning to FIG. 1, the first differential mechanism 38 is in a direct connection state, a reverse rotation speed change state of the engine 12, a neutral state (neutral state), and an internal lock state by switching each operating state of the clutch CL1 and the brake BR1. It is possible to form four states. Specifically, the first differential mechanism 38 is in a directly connected state in which each rotating element of the first differential mechanism 38 is integrally rotated in the engaged state of the clutch CL1. Further, in the first differential mechanism 38, when the brake BR1 is engaged, the rotation of the first ring gear R1 is set to zero [rpm], and the first sun gear S1 (first difference) with respect to the normal rotation of the engine rotation speed Ne. The output rotating member of the moving mechanism 38) is in a reverse rotation speed change state of the engine 12 in which the rotation is negative. Further, the first differential mechanism 38 is in a neutral state in which the differential of the first differential mechanism 38 is allowed in the released state of the clutch CL1 and the released state of the brake BR1. Further, the first differential mechanism 38 is in an internal lock state in which each rotating element of the first differential mechanism 38 stops rotating when the clutch CL1 is engaged and the brake BR1 is engaged.

The second differential mechanism 40 divides the power of the engine 12 input to the second ring gear R2 into the first rotary machine MG1 and the second carrier C2 (the distribution also agrees) in a state where the differential is allowed. It can function as a mechanism. Therefore, in the vehicle 10, the direct torque (also referred to as the engine direct torque) that is mechanically transmitted to the second carrier C2 by taking the reaction force of the engine torque Te input to the second ring gear R2 by the first rotary machine MG1. It is possible to run the engine with MG2 torque Tm by the second rotary machine MG2 driven by the generated power of the first rotary machine MG1 by the power divided into the first rotary machine MG1. As a result, the second differential mechanism 40 is known to control the gear ratio (gear ratio) by controlling the power control unit 50 by the electronic control device 90 described later and controlling the operating state of the first rotary machine MG1. Functions as an electric differential unit (electric continuously variable transmission). That is, the second differential mechanism 40 is an electric transmission mechanism in which the differential state is controlled by controlling the operating state of the first rotating machine MG1.

The first power transmission unit 20 can form an electric continuously variable transmission that operates at a power division ratio different from the power division ratio in the second differential mechanism 40. That is, in the first power transmission unit 20, in addition to the first sun gear S1 (third rotating element RE3) and the second ring gear R2 (sixth rotating element RE6) being connected, the clutch CLc is engaged. By connecting the first ring gear R1 (second rotating element RE2) and the second carrier C2 (fifth rotating element RE5), the first differential mechanism 38 and the second differential mechanism 40 become 1 An electric type that constitutes two differential mechanisms and operates the entire first differential mechanism 38 and the second differential mechanism 40 at a power division ratio different from the power division ratio of the second differential mechanism 40 alone. It can function as a continuously variable transmission.

In the first power transmission unit 20, the first differential mechanism 38 in which the above-mentioned four states are formed and the second differential mechanism 40 are connected, and the vehicle 10 switches the operating state of the clutch CLc. In addition, it is possible to realize a plurality of driving modes described later.

In the first power transmission unit 20 configured in this way, the power of the engine 12 and the power of the first rotary machine MG1 are transmitted to the output shaft 24. Therefore, the engine 12 and the first rotary machine MG1 are connected to the drive wheels 16 via the first power transmission unit 20 so as to be able to transmit power.

The second power transmission unit 22 is arranged coaxially with the input shaft 36 (or the output shaft 24), and includes a second rotary machine MG2 and a reduction mechanism 44 connected to the output shaft 24. The reduction mechanism 44 uses a third ring gear R3 that meshes with the third sun gear S3 via a third carrier C3 and a third pinion gear P3 that support the third sun gear S3, the third pinion gear P3, and the third pinion gear P3 so as to rotate and revolve. It is a known single pinion type planetary gear mechanism having. The third sun gear S3 is an input element connected to the rotor shaft 46 of the second rotary machine MG2. The third ring gear R3 is a reaction force element connected to the case 18. The third carrier C3 is an output element connected to the output shaft 24. The reduction mechanism 44 configured in this way decelerates the MG2 rotation speed Nm and transmits it to the output shaft 24. As a result, in the second power transmission unit 22, the power of the second rotary machine MG2 is transmitted to the output shaft 24 without passing through the first power transmission unit 20. Therefore, the second rotary machine MG2 is connected to the drive wheels 16 so as to be able to transmit power without going through the first power transmission unit 20. That is, the second rotary machine MG2 is a rotary machine that is connected to the drive shaft 34, which is an output rotating member of the power transmission device 14, so that power can be transmitted without going through the first power transmission unit 20. The output rotating member of the power transmission device 14 is an output rotating member connected to the drive wheels 16, and in addition to the drive shaft 34, the output shaft 24, the propeller shaft 26, and the like are also agreed.

The power transmission device 14 configured in this way is suitably used for FR (front engine / rear drive) type vehicles. Further, in the power transmission device 14, the power of the engine 12, the power of the first rotary machine MG1 and the power of the second rotary machine MG2 are transmitted to the output shaft 24, and the differential gear 32 and the drive shaft 34 are transmitted from the output shaft 24. Etc. are sequentially transmitted to the drive wheels 16.

The vehicle 10 includes an electronic control device 90 as a controller including a control device of the vehicle 10 related to control of the engine 12, the power transmission device 14, and the like. The electronic control device 90 is configured to include, for example, a so-called microcomputer provided with a CPU, a RAM, a ROM, an input / output interface, etc. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control device 90 is designed to execute output control of the engine 12, the first rotary machine MG1, and the second rotary machine MG2, switching control of the traveling mode described later, and the like, and the engine is required. It is divided into control, rotary machine control, hydraulic control, etc.

The electronic control device 90 includes various sensors provided in the vehicle 10 (for example, an engine rotation speed sensor 70, an output rotation speed sensor 72, an MG1 rotation speed sensor 74 such as a resolver, an MG2 rotation speed sensor 76 such as a resolver, and an accelerator open. Various signals based on the values detected by the degree sensor 78, shift position sensor 80, battery sensor 82, wheel speed sensor 84, etc. (for example, engine rotation speed Ne, output rotation speed which is the rotation speed of the output shaft 24 corresponding to vehicle speed V) No, MG1 rotation speed Ng, MG2 rotation speed Nm, accelerator opening θacc, "P", "R", "N", "D", etc. Shift lever operation position (shift position) POSsh, battery of battery unit 52 Temperature THbat, battery charge / discharge current Ibat, battery voltage Vbat, wheel speed Nr of each wheel (including drive wheel 16), etc.) are supplied. Further, from the electronic control device 90, various devices provided in the vehicle 10 (for example, an engine control device 54 such as a throttle actuator, a fuel injection device, and an ignition device, a power control unit 50, a hydraulic control circuit 60, an EOP 66, etc.) Command signals (for example, engine control command signal Se for controlling the engine 12, rotary machine control command signal Smg for controlling the first rotary machine MG1 and the second rotary machine MG2, each engaging device (clutch CL1, brake). The hydraulic control command signal Sp for controlling the operating state of the BR1 and the clutch CLc), the pump drive control command signal Sop for driving the EOP66, etc.) are output, respectively. The electronic control device 90 calculates the charge capacity SOC (also referred to as battery capacity SOC) of the battery unit 52 as a value indicating the charge state of the battery unit 52 based on, for example, the battery charge / discharge current Ibat and the battery voltage Vbat. ..

The electronic control device 90 includes a hybrid control means, that is, a hybrid control unit 92, and a power transmission switching means, that is, a power transmission switching unit 94, in order to realize control functions for various controls in the vehicle 10. The power transmission switching unit 94 corresponds to the control unit of the present invention.

The hybrid control unit 92 controls the opening and closing of the electronic throttle valve, controls the fuel injection amount and the injection timing, outputs the engine control command signal Se that controls the ignition timing, and obtains the target engine torque Te * of the engine 12. The output control of the engine 12 is executed as described above. Further, the hybrid control unit 92 outputs a rotary machine control command signal Smg for controlling the operation of the first rotary machine MG1 and the second rotary machine MG2 to the power control unit 50, and outputs the target torque of MG1 torque Tg and MG2 torque Tm. The output control of the first rotating machine MG1 and the second rotating machine MG2 is executed so that

The hybrid control unit 92 calculates the required drive torque based on the accelerator opening θacc and the vehicle speed V, and takes into consideration the required charging value (charging required power) and the like so that the engine operates with low fuel consumption and a small amount of exhaust gas. 12. The required drive torque is generated from at least one of the first rotary machine MG1 and the second rotary machine MG2.

The hybrid control unit 92 selectively establishes a motor running (EV running) mode and a hybrid running (HV running) mode (also referred to as an engine running mode) as running modes according to the running state. The EV traveling mode is a control that enables motor traveling in which at least one of the first rotating machine MG1 and the second rotating machine MG2 is used as a power source for running while the operation of the engine 12 is stopped. It is a style. The HV traveling mode is a control mode that enables HV traveling (engine traveling) in which at least the engine 12 is used as a power source for traveling (that is, the power of the engine 12 is transmitted to the drive wheels 16 to travel). Even in a mode that does not assume the running of the vehicle 10, such as a mode in which the power of the engine 12 is converted into electric power by the power generation of the first rotary machine MG1 and the electric power is exclusively charged to the battery unit 52, the engine Since 12 is in the driving state, it is included in the HV driving mode.

The power transmission switching unit 94 controls the operating states of the clutch CL1, the brake BR1, and the clutch CLc based on the traveling mode established by the hybrid control unit 92. The power transmission switching unit 94 engages and / or disengages the clutch CL1, the brake BR1, and the clutch CLc, respectively, so that the power transmission for traveling in the traveling mode established by the hybrid control unit 92 is possible. The hydraulic control command signal Sp to be operated is output to the hydraulic control circuit 60.

Here, the traveling modes that can be executed by the vehicle 10 will be described with reference to FIGS. 3 and 4 to 16. FIG. 3 is a chart showing each operating state of the clutch CL1, the brake BR1, and the clutch CLc in each traveling mode. In the chart of FIG. 3, ○ indicates the engagement of the engaging devices (clutch CL1, brake BR1, clutch CLc), blank indicates release, and Δ indicates the engine in which the engine 12 in the stopped operation state is rotated. It indicates that when a brake (also called an engine brake) is used in combination, either one may be engaged or both may be engaged depending on the situation. Further, "G" indicates that the rotating machine (MG1, MG2) mainly functions as a generator, and "M" mainly causes the rotating machine (MG1, MG2) to function as a motor when driving, and mainly as a generator during regeneration. It is shown to function as. As shown in FIG. 3, the vehicle 10 can selectively realize the EV traveling mode and the HV traveling mode as the traveling modes. The EV drive mode includes a single drive EV mode, which is a control mode in which a motor can run with the second rotary machine MG2 as a single power source, and a motor run with the first rotary machine and the second rotary machine MG2 as a power source. It has two modes, a dual drive EV mode, which is a possible control mode. The HV driving modes are an overdrive (O / D) input split mode (hereinafter referred to as O / DHV mode), an underdrive (U / D) input split mode (hereinafter referred to as U / DHV mode), and a fixed stage mode. It has three modes:

FIG. 4-FIG. 16 is a collinear diagram capable of relatively representing the rotation speeds of the rotating elements RE1-RE6 in each of the first differential mechanism 38 and the second differential mechanism 40. In this co-line diagram, the vertical lines Y1-Y4 representing the rotation speed of each rotating element are in order from the left toward the paper surface, and the vertical line Y1 is the second sun gear which is the fourth rotating element RE4 to which the first rotating machine MG1 is connected. The rotation speed of S2, the vertical line Y2 is the rotation speed of the first carrier C1 which is the first rotation element RE1 to which the engine 12 (see "ENG" in the figure) is connected, and the vertical line Y3 is via the brake BR1. The rotational speed of the first ring gear R1 which is the second rotating element RE2 selectively connected to the case 18, and the second rotating element RE5 which is the fifth rotating element RE5 connected to the output shaft 24 (see "OUT" in the figure). The rotation speed of the carrier C2 is indicated by vertical lines Y4, respectively, indicating the rotation speeds of the first sun gear S1 which is the third rotation element RE3 and the second ring gear R2 which is the sixth rotation element RE6. The second rotary machine MG2 is connected to the output shaft 24 via a reduction mechanism 44. The arrows in the white squares (□) indicate MG1 torque Tg, the arrows in white circles (◯) indicate engine torque Te, and the arrows in black circles (●) indicate MG2 torque Tm. Further, the clutch CL1 that selectively connects the first carrier C1 and the first ring gear R1 is shown in white, the clutch CL1 is in the released state, and the clutch CL1 is shown in hatching (diagonal line). The engaged state of CL1 is shown respectively. Further, the white diamond mark (◇) in the brake BR1 that selectively connects the first ring gear R1 to the case 18 indicates the released state of the brake BR1, and the black diamond mark (◆) indicates the engaged state of the brake BR1. .. Further, the white diamond mark (◇) in the clutch CLc that selectively connects the first ring gear R1 and the second carrier C2 indicates the released state of the clutch CLc, and the black diamond mark (◆) indicates the engaged state of the clutch CLc. Shown. Further, the straight line representing the rotational speed relative to the first differential mechanism 38 is shown by a broken line, and the straight line representing the rotational speed relative to the second differential mechanism 40 is shown by a solid line. The arrow in the black circle (●) is driven by the power generated by the first rotary machine MG1 by the power of the engine 12 divided into the first rotary machine MG1 and / or the power supplied from the battery unit 52. It is the MG2 torque Tm by the second rotary machine MG2, and does not include the direct torque of the engine. Further, the black diamond mark (◆) in the clutch CLc overlaps with the black circle mark (●), so that it is not shown in the figure. The distance between the vertical lines Y1, Y2, Y3, and Y4 is determined according to the gear ratios ρ1 and ρ2 of the differential mechanisms 38 and 40. 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 collinear diagram, the gear ratio ρ (= number of teeth of the sun gear / ring gear) of the planetary gear mechanism is between the carrier and the ring gear. The interval corresponds to the number of teeth).

FIG. 4 is a collinear diagram in the single drive EV mode. The independent drive EV mode is realized in a state where the clutch CL1, the brake BR1, and the clutch CLc are all released, as shown in the “normal” of FIG. In the single drive EV mode, the clutch CL1 and the brake BR1 are released, the differential of the first differential mechanism 38 is allowed, and the first differential mechanism 38 is set to the neutral state. The hybrid control unit 92 stops the operation of the engine 12 and outputs the MG2 torque Tm for traveling from the second rotary machine MG2. FIG. 4 shows a case where the second rotary machine MG2 is rotating forward (that is, the rotation direction of the second carrier C2 when the vehicle 10 is moving forward) and is outputting a positive torque. When moving backward, the second rotary machine MG2 is rotated in the reverse direction with respect to the time when moving forward. While the vehicle is running, the second carrier C2 connected to the output shaft 24 is rotated in conjunction with the rotation of the second rotary machine MG2 (here, the rotation of the drive wheels 16 is also agreed). In the single drive EV mode, since the clutch CLc is further released, the engine 12 and the first rotary machine MG1 are not rotated, respectively, and the engine rotation speed Ne and the MG1 rotation speed Ng can be set to zero. As a result, it is possible to reduce the drag loss of each of the engine 12 and the first rotary machine MG1 and improve the power consumption (that is, suppress the power consumption). The hybrid control unit 92 maintains the MG1 rotation speed Ng at zero by feedback control. Alternatively, the hybrid control unit 92 executes control (d-axis lock control) to pass a current through the first rotary machine MG1 so that the rotation of the first rotary machine MG1 is fixed, and maintains the MG1 rotation speed Ng at zero. To do. Alternatively, even if the MG1 torque Tg is set to zero, it is not necessary to add the MG1 torque Tg when the MG1 rotation speed Ng can be maintained at zero by the cogging torque of the first rotating machine MG1. The independent drive EV mode is a traveling mode in which the motor can be driven by using only the second rotary machine MG2 as a power source with the clutch CL1 and the clutch CLc released. Even if the control for maintaining the MG1 rotation speed Ng at zero is performed, the first power transmission unit 20 is in a neutral state in which the reaction force of the MG1 torque Tg cannot be taken, so that the drive torque is not affected. Alternatively, in the single drive EV mode, the first rotary machine MG1 may be idled with no load.

FIG. 5 is a collinear diagram in the dual drive EV mode. The dual drive EV mode is realized in a state where the clutch CL1 and the brake BR1 are engaged and the clutch CLc is released, as shown in "both drives" in FIG. In the dual drive EV mode, the clutch CL1 and the brake BR1 are engaged, the differential of the first differential mechanism 38 is regulated, and the rotation of the first ring gear R1 is stopped. Therefore, the rotation of any rotating element of the first differential mechanism 38 is stopped, and the first differential mechanism 38 is set to the internal locked state. As a result, the engine 12 is stopped at zero rotation, and the second ring gear R2 connected to the first sun gear S1 is also fixed at zero rotation. When the second ring gear R2 is fixed so as not to rotate, the reaction torque of MG1 torque Tg can be obtained by the second ring gear R2, so that the torque based on MG1 torque Tg is mechanically output from the second carrier C2 to drive the drive wheels. It can be transmitted to 16. The hybrid control unit 92 stops the operation of the engine 12 and outputs MG1 torque Tg and MG2 torque Tm for traveling from the first rotating machine MG1 and the second rotating machine MG2, respectively. FIG. 5 shows a case in which the first rotary machine MG1 and the second rotary machine MG2 are both in the forward rotation and output positive torque in the forward rotation. When moving backward, the first rotating machine MG1 and the second rotating machine MG2 are rotated in the reverse direction with respect to the time when moving forward.

As shown in the description using FIGS. 4 and 5, the single drive EV mode drives the vehicle 10 only by the second rotary machine MG2, and the double drive EV mode drives the first rotary machine MG1 and the second rotary machine MG2. It is possible to drive the vehicle 10. Therefore, in the case of motor traveling, when the load is low, the independent drive EV mode is established and the second rotary machine MG2 is used for independent travel, and when the load is high, the double drive EV mode is established and the first rotary machine Both are driven by MG1 and the second rotary machine MG2. Regeneration during vehicle deceleration, including engine running, is mainly executed by the second rotary machine MG2.

When regenerative control is performed by the second rotary machine MG2 while traveling in the single drive EV mode, the engine 12 whose operation has been stopped is not rotated and is stopped at zero rotation, so a large amount of regeneration should be taken. Can be done. On the other hand, if the battery unit 52 is in a fully charged state during traveling in the independent drive EV mode, regenerative energy cannot be obtained, so that braking torque cannot be obtained by the regenerative brake. When running in the stand-alone drive EV mode, if the battery unit 52 is fully charged and regenerative energy cannot be obtained, braking torque is obtained with the engine brake, or if the battery unit 52 is nearly fully charged, the engine brake is used together. It is conceivable to do. From another point of view, if the battery capacity SOC decreases during traveling in the single drive EV mode and it becomes difficult to secure the electric power to be supplied to the second rotary machine MG2, the second rotary machine MG2 cannot be driven. If the battery capacity SOC drops during driving in the single drive EV mode, it is conceivable to switch to engine driving. From the above, the EV driving mode has a standby mode in which the engine brake is applied promptly or a preparation for promptly switching to the engine driving is provided, and an emblem combined mode in which the engine brake is used in combination. ..

6 and 7 are collinear diagrams in the standby mode in the EV traveling mode, respectively. This standby mode is realized in a state where the clutch CL1 or the clutch CLc is engaged, as shown in the “standby mode” of FIG. When the clutch CL1 or the clutch CLc is engaged, the engine 12 can be put into a rotating state, but in this standby mode, the first rotary machine MG1 is idled with no load, so that the engine 12 in the stopped operation is zero. It is stopped by rotation. Therefore, in this standby mode, the motor running or regeneration control can be performed by the second rotary machine MG2 without applying the engine brake. From the standby mode, the engine rotation speed Ne is raised by the first rotary machine MG1 and the reaction force of the engine torque Te (negative value) is taken by the first rotary machine MG1. The brake can be applied. Further, from the state of the standby mode, the engine rotation speed Ne can be increased and ignited by the first rotary machine MG1, so that the engine running can be started.

The operating state of each engaging device (clutch CL1, brake BR1, clutch CLc) in the standby mode in which the clutch CL1 is engaged as shown in FIG. 6 is the forward traveling in the U / DHV mode of the HV traveling mode described later. It is the same as the operating state of each engaging device. Although the engine 12 is not operated in the standby mode, for convenience, the standby mode in which the clutch CL1 is engaged is referred to as a standby mode in the U / D input split.

The operating state of each engaging device in the standby mode in which the clutch CLc is engaged as shown in FIG. 7 is the same as the operating state of each engaging device in the forward traveling in the O / DHV mode of the HV traveling mode described later. Is. For convenience, the standby mode in which the clutch CLc is engaged is referred to as a standby mode in the O / D input split.

8 and 9 are collinear diagrams in the EV traveling mode and the engine braking combined mode, respectively. This engine braking combined mode is realized in a state where the clutch CL1 or the clutch CLc is engaged, as shown in the "engine braking combined use" of FIG. When the clutch CL1 or the clutch CLc is engaged, the engine 12 is brought into a rotating state. Therefore, in this emblem combined mode, the engine torque Te (negative value) is controlled by the first rotary machine MG1 while controlling the engine rotation speed Ne. By taking the reaction force of, the engine brake can be applied according to the engine rotation speed Ne. Therefore, in this emblem combined mode, the engine brake can be applied in addition to or in place of the regenerative brake by the second rotary machine MG2. The engine brake can also be applied by engaging the clutch CL1 and the clutch CLc. In this case, it is not necessary to take the reaction force of the engine torque Te (negative value) in the first rotary machine MG1. The operating state of each engaging device (clutch CL1, brake BR1, clutch CLc) in the emblem combined mode in which the clutch CL1 and the clutch CLc are engaged is described in the direct connection fixed stage mode of the HV traveling mode described later. It is in the same state as the operating state.

The operating state of each engaging device (clutch CL1, brake BR1, clutch CLc) in the emblem combined mode in which the clutch CL1 is engaged as shown in FIG. It is the same state as the operating state of each engaging device in. Although the engine 12 is not operated in the emblem combined mode, the emblem combined mode in which the clutch CL1 is engaged is referred to as an emblem combined mode in the U / D input split for convenience.

The operating state of each engaging device in the emblem combined mode in which the clutch CLc is engaged as shown in FIG. 9 is the same as the operating state of each engaging device in the forward traveling in the O / DHV mode of the HV traveling mode described later. It is in a state. For convenience, the emblem combined mode in which the clutch CLc is engaged is referred to as an emblem combined mode in the O / D input split.

FIG. 10 is a collinear diagram in forward traveling in the U / DHV mode of the HV traveling mode. In the forward running in the U / DHV mode (hereinafter referred to as the U / DHV mode (forward)), as shown in the "forward" of the "U / D input split" in FIG. 3, the clutch CL1 is engaged and the brake is applied. It is realized in the state where BR1 and the clutch CLc are released. In the U / DHV mode (forward), the clutch CL1 is engaged and the brake BR1 is released, and the first differential mechanism 38 is in a directly connected state. Therefore, the power of the engine 12 input to the first carrier C1 is input. Is directly transmitted to the second ring gear R2 connected to the first sun gear S1. In addition, in the U / DHV mode (forward), the clutch CLc is released, and the second differential mechanism 40 alone constitutes an electric continuously variable transmission. As a result, the first power transmission unit 20 can divide the power of the engine 12 input to the second ring gear R2 into the second sun gear S2 and the second carrier C2. That is, in the first power transmission unit 20, the direct torque of the engine is mechanically transmitted to the second carrier C2 by taking the reaction force of the engine torque Te input to the second ring gear R2 by the first rotary machine MG1. At the same time, the power generated by the first rotating machine MG1 by the power of the engine 12 divided into the first rotating machine MG1 is transmitted to the second rotating machine MG2 via a predetermined electric path. The hybrid control unit 92 operates (operates) the engine 12 and outputs MG1 torque Tg, which is a reaction torque with respect to the engine torque Te, by the power generation of the first rotary machine MG1. The MG2 torque Tm is output from the two-turn machine MG2. The hybrid control unit 92 can also drive the second rotary machine MG2 by adding the power supplied from the battery unit 52 to the generated power of the first rotary machine MG1. FIG. 10 shows a case where the second rotary machine MG2 is traveling forward by outputting a positive torque in the forward rotation.

FIG. 11 is a collinear diagram in forward traveling in the O / DHV mode of the HV traveling mode. The forward running in the O / DHV mode (hereinafter referred to as the O / DHV mode (forward)) is a state in which the clutch CL1 and the brake BR1 are released, as shown in the “forward” of the “O / D input split” in FIG. Moreover, it is realized in a state where the clutch CLc is engaged. In the O / DHV mode (forward), the clutch CLc is engaged, and the first differential mechanism 38 and the second differential mechanism 40 form one differential mechanism. In addition, in the O / DHV mode (forward), the clutch CL1 and the brake BR1 are released, and the first differential mechanism 38 and the second differential mechanism 40 as a whole are combined with the second differential mechanism 40 alone. An electric continuously variable transmission that operates at a power division ratio different from that of the above is configured. As a result, the first power transmission unit 20 can divide the power of the engine 12 input to the first carrier C1 into the second sun gear S2 and the second carrier C2. That is, in the first power transmission unit 20, the direct torque of the engine is mechanically transmitted to the second carrier C2 by taking the reaction force of the engine torque Te input to the first carrier C1 by the first rotary machine MG1. At the same time, the power generated by the first rotating machine MG1 by the power of the engine 12 divided into the first rotating machine MG1 is transmitted to the second rotating machine MG2 via a predetermined electric path. The hybrid control unit 92 operates (operates) the engine 12 and outputs MG1 torque Tg, which is a reaction torque with respect to the engine torque Te, by the power generation of the first rotary machine MG1. The MG2 torque Tm is output from the two-turn machine MG2. FIG. 11 shows a case where the second rotary machine MG2 is moving forward while outputting a positive torque in the forward rotation.

FIG. 12 is a collinear diagram of the reverse running in the U / DHV mode of the HV running mode, and the rotation and torque of the engine 12 with respect to the configuration achieving the function as an electric continuously variable transmission. Is input in reverse to a negative value, which is the case of engine reverse input. The reverse running with the U / DHV mode engine reverse input (hereinafter referred to as U / DHV mode reverse input (reverse)) is shown in the "engine reverse input" of the "reverse" of the "U / D input split" of FIG. As described above, the brake BR1 is engaged and the clutch CL1 and the clutch CLc are released. At the U / DHV mode reverse input (reverse), the clutch CL1 is released and the brake BR1 is engaged, and the first differential mechanism 38 is in the reverse rotation speed change state of the engine 12, so that the first carrier C1 is engaged. The input power of the engine 12 is transmitted to the second ring gear R2 connected to the first sun gear S1 by negative rotation and negative torque. In addition, at the U / DHV mode reverse input (reverse), the clutch CLc is released, and the second differential mechanism 40 alone constitutes an electric continuously variable transmission. As a result, the first power transmission unit 20 can divide the power of the engine 12 input to the second ring gear R2 in reverse to the second sun gear S2 and the second carrier C2. The hybrid control unit 92 operates (operates) the engine 12, outputs MG1 torque Tg which is a reaction torque with respect to the engine torque Te by the power running of the first rotary machine MG1, and uses the power supplied from the battery unit 52 to output the MG1 torque Tg. The MG2 torque Tm is output from the two-turn machine MG2. FIG. 12 shows a case where the second rotary machine MG2 outputs a negative torque in a negative rotation and travels backward. Further, in the U / DHV mode reverse input (reverse), the power of the engine 12 is transmitted to the second ring gear R2 by negative rotation and negative torque, so that the drive torque for reverse travel is output together with the MG2 torque Tm. Can be done. The second rotary machine MG2 may output a positive torque in a negative rotation in order to generate electric power used for power running of the first rotary machine MG1. Even in this case, the engine direct torque which is a negative torque is higher. Since the absolute value is larger than the MG2 torque Tm, reverse running is possible.

FIG. 13 is a collinear diagram in the reverse travel in the U / DHV mode of the HV travel mode, and is the case of the engine forward rotation input. The reverse running with the U / DHV mode engine forward rotation input (hereinafter referred to as the U / DHV mode normal rotation input (reverse)) is the "engine forward rotation input" of the "backward" of the "U / D input split" in FIG. As shown in the above, the clutch CL1 is engaged and the brake BR1 and the clutch CLc are released. In the U / DHV mode forward rotation input (reverse), the clutch CL1 is engaged and the brake BR1 is released, and the first differential mechanism 38 is in a directly connected state. Therefore, the engine input to the first carrier C1 The power of 12 is directly transmitted to the second ring gear R2 connected to the first sun gear S1. In addition, in the U / DHV mode forward rotation input (reverse), the clutch CLc is released, and the second differential mechanism 40 alone constitutes an electric continuously variable transmission. As a result, the first power transmission unit 20 can divide the power of the engine 12 input to the second ring gear R2 into the second sun gear S2 and the second carrier C2. The hybrid control unit 92 operates (operates) the engine 12 and outputs MG1 torque Tg, which is a reaction torque with respect to the engine torque Te, by the power generation of the first rotary machine MG1. The MG2 torque Tm is output from the two-turn machine MG2. FIG. 13 shows a case where the second rotary machine MG2 outputs a negative torque in a negative rotation and travels backward. Although the direct torque of the engine is positive torque, it is driven by the generated power of the first rotating machine MG1 (or is driven by adding the power supplied from the battery unit 52 to the generated power of the first rotating machine MG1. Since the output torque (negative value) of the second rotary machine MG2 has an absolute value larger than the engine direct torque, it is possible to drive in reverse.

FIG. 14 is a collinear diagram in the reverse traveling in the O / DHV mode of the HV traveling mode, and is the case of the engine forward rotation input. The reverse running with the engine forward rotation input in the O / DHV mode (hereinafter referred to as the O / DHV mode forward rotation input (reverse)) is the "engine forward rotation input" of the "reverse" of the "O / D input split" in FIG. As shown in the above, the clutch CL1 and the brake BR1 are released, and the clutch CLc is engaged. In the O / DHV mode forward rotation input (reverse), the clutch CLc is engaged, and the first differential mechanism 38 and the second differential mechanism 40 form one differential mechanism. In addition, in the O / DHV mode forward rotation input (reverse), the clutch CL1 and the brake BR1 are released, and the first differential mechanism 38 and the second differential mechanism 40 as a whole are combined with the second differential mechanism. An electric continuously variable transmission that operates at a power division ratio different from the power division ratio of the 40 alone is configured. As a result, the first power transmission unit 20 can divide the power of the engine 12 input to the first carrier C1 into the second sun gear S2 and the second carrier C2. The hybrid control unit 92 operates (operates) the engine 12 and outputs MG1 torque Tg, which is a reaction torque with respect to the engine torque Te, by the power generation of the first rotary machine MG1. The MG2 torque Tm is output from the two-turn machine MG2. FIG. 14 shows a case where the second rotary machine MG2 outputs a negative torque in a negative rotation and travels backward. Although the direct torque of the engine is a positive torque, it is possible to drive in the reverse direction as in the case of the U / DHV mode forward rotation input (reverse).

As shown in the description using FIGS. 10-14, in the U / DHV mode and the O / DHV mode, the power of the engine 12 is relative to the configuration that achieves the function as an electric continuously variable transmission. The rotating elements to which are input are different, and the power division ratio when the first power transmission unit 20 functions as an electric continuously variable transmission is different. That is, the ratio of each output torque and each rotation speed of the rotary machines MG1 and MG2 to the engine 12 can be changed between the O / DHV mode and the U / DHV mode. The operating state of the clutch CLc is switched in order to change the ratio of each output torque and each rotation speed of the rotating machines MG1 and MG2 to the engine 12 while the engine is running.

The MG1 rotation speed Ng is set to zero, and the power of the engine 12 is all machine without passing through an electric path (an electric power transmission path which is an electric path related to power transfer of the first rotating machine MG1 and the second rotating machine MG2). In the U / DHV mode, there is a case where the rotation of the engine 12 is decelerated and the underdrive state is output from the second carrier C2 in the state of the so-called mechanical point where the electric power is transmitted to the second carrier C2. The O / DHV mode is a case where the rotation speed of the engine 12 is accelerated and an overdrive state is output from the second carrier C2. The engine direct torque in the U / DHV mode is increased with respect to the engine torque Te. On the other hand, the direct engine torque in the O / DHV mode is reduced with respect to the engine torque Te.

The U / DHV mode (forward), the U / DHV mode forward rotation input (reverse), and the emblem combined mode in the U / D input split are clutches that are engaging devices of either clutch CL1 or clutch CLc. The differential state of the second differential mechanism 40 is controlled by controlling the operating state of the first rotary machine MG1 in the state where the CL1 is engaged (that is, the state where the clutch CL1 is engaged and the clutch CLc is released). In this mode (that is, when an electric continuously variable transmission is configured), a torque larger than the engine torque Te is mechanically transmitted to the second carrier C2. On the other hand, the O / DHV mode (forward), the O / DHV mode forward rotation input (reverse), and the emblem combined mode in the O / D input split are the engaging devices of one of the clutch CL1 and the clutch CLc. Is the second differential by controlling the operating state of the first rotary machine MG1 in the state where the clutch CLc, which is another engaging device, is engaged (that is, the clutch CL1 is released and the clutch CLc is engaged). When the differential state of the mechanism 40 is controlled, the second traveling mode is in which the torque reduced from the engine torque Te is mechanically transmitted to the second carrier C2.

FIG. 15 is a collinear diagram in the fixed stage mode of the HV traveling mode, and is a case of direct connection in which the rotating elements of the first differential mechanism 38 and the second differential mechanism 40 are integrally rotated. The direct connection of the fixed stage mode (hereinafter referred to as the direct connection fixed stage mode) is a state in which the clutch CL1 and the clutch CLc are engaged and the brake BR1 is as shown in "Direct connection" of "Advance" of "Fixed stage" in FIG. Is realized in the released state. In the direct connection fixed stage mode, the clutch CL1 is engaged and the brake BR1 is released, and the first differential mechanism 38 is in the direct connection state. In addition, in the direct connection fixed stage mode, the clutch CLc is engaged, and each rotating element of the first differential mechanism 38 and the second differential mechanism 40 is integrally rotated. As a result, the first power transmission unit 20 can directly output from the second carrier C2 without increasing or decreasing the torque of the engine 12. In this direct connection fixed stage mode, when the clutch CL1 and the clutch CLc are engaged, each rotating element of the first differential mechanism 38 and the second differential mechanism 40 is integrally rotated, and the torque of the engine 12 is increased or decreased. This is the third traveling mode, which is mechanically transmitted to the second carrier C2 without any trouble. The hybrid control unit 92 outputs the running engine torque Te from the engine 12. In this direct connection fixed stage mode, the power of the first rotating machine MG1 can be driven by the electric power from the battery unit 52, and the power of the first rotating machine MG1 can be directly output from the second carrier C2. Further, in this direct connection fixed stage mode, the second rotary machine MG2 can be driven by the electric power from the battery unit 52, and the power of the second rotary machine MG2 can be transmitted to the drive wheels 16. Therefore, in addition to outputting the engine torque Te, the hybrid control unit 92 may output the running torque from at least one of the first rotating machine MG1 and the second rotating machine MG2. That is, in the direct connection fixed stage mode, the vehicle 10 may be driven only by the engine 12, or torque assist may be performed by the first rotary machine MG1 and / or the second rotary machine MG2.

FIG. 16 is a collinear diagram in the fixed stage mode of the HV traveling mode, and is a case where the second carrier C2 is fixed so as not to rotate, and the output shaft is fixed. The fixed output shaft mode (hereinafter referred to as the fixed output shaft mode) engages the brake BR1 and the clutch CLc as shown in "Fixed output shaft" of "Advance" of "Fixed stage" in FIG. It is realized in a state and a state in which the clutch CL1 is released. In the output shaft fixed stage mode, the clutch CLc is engaged, and the first differential mechanism 38 and the second differential mechanism 40 form one differential mechanism. In addition, in the output shaft fixed stage mode, the brake BR1 is engaged and the clutch CL1 is released, so that the second carrier C2 is fixed so as not to rotate. As a result, in the first power transmission unit 20, the reaction force of the power of the engine 12 input to the first carrier C1 can be taken by the first rotary machine MG1. Therefore, in the output shaft fixed stage mode, the battery unit 52 can be charged with the power generated by the first rotary machine MG1 powered by the engine 12. The hybrid control unit 92 operates (operates) the engine 12, takes a reaction force against the power of the engine 12 by the power generation of the first rotary machine MG1, and transmits the generated power of the first rotary machine MG1 via the power control unit 50. The battery unit 52 is charged. In this output shaft fixed stage mode, since the second carrier C2 is fixed so as not to rotate, the battery unit 52 is exclusively charged when the vehicle 10 is stopped. As shown in the description using FIGS. 15 and 16, the clutch CLc is engaged in the direct connection fixed stage mode and the output shaft fixed stage mode of the HV traveling mode.

In the region where the reduction ratio I (= Ne / No) of the first power transmission unit 20 is relatively large, the output ratio of MG1 power Pg to engine power Pe (Pg / Pe) and the output ratio of MG2 power Pm to engine power Pe. Each absolute value of (Pm / Pe) is made smaller in the U / DHV mode than in the O / DHV mode. Therefore, in the region where the reduction ratio I is relatively large, the increase in MG1 power Pg and the increase in MG2 power Pm can be suppressed by establishing the U / DHV mode. On the other hand, in a relatively small region where the reduction ratio I is smaller than "1", the output ratio (Pm / Pe) becomes a negative value (that is, the output ratio (Pg / Pe) becomes a positive value), and the output ratio ( The absolute values of Pg / Pe) and output ratio (Pm / Pe) are made larger in the U / DHV mode than in the O / DHV mode. In the state where the output ratio (Pm / Pe) is a negative value (that is, the state where the output ratio (Pg / Pe) is a positive value), the second rotary machine MG2 generates power, and the generated power is transferred to the first rotary machine MG1. It is a power circulation state to be supplied. It is desirable to avoid or suppress this power circulation state as much as possible. Therefore, in the region where the reduction ratio I is relatively small, the power circulation power can be reduced by establishing the O / DHV mode. By switching between the U / DHV mode and the O / DHV mode according to the reduction ratio I, the engine power can be transmitted by the rotary machines MG1 and MG2 having lower output (low power).

That is, the U / DHV mode is established when the load of the engine 12 using the relatively large reduction ratio I is high, and the O / DHV mode is established when the load of the engine 12 using the relatively small reduction ratio I is low or the vehicle speed is high. In addition, by properly using the U / DHV mode and the O / DHV mode, an increase in each torque and each rotation speed of the rotary machines MG1 and MG2 is prevented or suppressed, and the power circulation power is reduced at a high vehicle speed. This reduces the energy conversion loss in the electric path and leads to improvement in fuel efficiency. Alternatively, it leads to miniaturization of the rotating machines MG1 and MG2.

17 and 18 are diagrams showing an example of a traveling mode switching map used for switching control between engine traveling and motor traveling, respectively. Each of these travel mode switching maps is a preliminary experiment having a boundary line between the engine travel region and the motor travel region with the vehicle speed V and the travel load of the vehicle 10 (hereinafter referred to as vehicle load) (for example, required drive torque) as variables. It is a relationship that is sought and stored (that is, predetermined) in terms of design or design.

FIG. 17 shows a state transition (that is, switching of the traveling mode of the vehicle 10) of the power transmission device 14 in CS (Charge Sustain) traveling while maintaining the battery capacity SOC. FIG. 17 is used when the vehicle 10 is, for example, a hybrid vehicle in which the battery capacity SOC is originally set to be relatively small. Alternatively, FIG. 17 is used when the mode in which the vehicle 10 holds the battery capacity SOC is established in, for example, a plug-in hybrid vehicle, a range extended vehicle, or the like in which a relatively large battery capacity SOC is originally set. On the other hand, FIG. 18 shows a state transition (that is, switching of a traveling mode of the vehicle 10) of the power transmission device 14 in a CD (Charge Depleting) traveling traveling while consuming the battery capacity SOC. FIG. 18 is used when the vehicle 10 is in a mode of consuming the battery capacity SOC in, for example, a plug-in hybrid vehicle or a range extended vehicle in which a relatively large battery capacity SOC is originally set. When the vehicle 10 is, for example, a hybrid vehicle in which the battery capacity SOC is originally set to be relatively small, it is preferable not to use FIG.

In FIG. 17, the region of each traveling mode according to the traveling state such as the vehicle speed V and the vehicle load so that the U / DHV mode is easily established when the load is high and the O / DHV mode is easily established when the load is low or the vehicle speed is high. Is set. Further, when the power of the battery unit 52 can be taken out (or when the warm-up of each device by the warm-up of the engine 12 or the operation of the engine 12 is completed), in the region where the operating efficiency of the engine 12 deteriorates. Power running of the second rotating machine MG2 is performed in the motor running. Therefore, the region of the independent drive EV mode is set in the region where the vehicle speed is low and the load is low as shown by the broken line. When the vehicle load is negative, deceleration running is performed in the U / DHV mode or the O / DHV mode by applying the engine brake using the negative torque of the engine 12. When the power of the battery unit 52 can be received, the regenerative control is performed by the second rotating machine MG2 in the motor running. Therefore, the region of the independent drive EV mode is set in the region where the vehicle load is negative as shown by the alternate long and short dash line. In the traveling mode switching map in CS traveling set in this way, for example, when starting, the U / DHV mode is established for both forward and backward traveling. As a result, the engine power Pe can be used more effectively, and the starting acceleration performance is improved. As the vehicle speed V increases in the forward traveling, the reduction ratio I of the first power transmission unit 20 becomes close to "1". In this state, the mode may be shifted to the direct connection fixed stage mode. In low vehicle speed running, the engine rotation speed Ne becomes extremely low, so the U / DHV mode is directly shifted to the O / DHV mode. In the direct connection fixed stage mode, since there is no power transmission via the rotary machines MG1 and MG2, the heat loss due to the conversion between the mechanical energy and the electric energy is eliminated. Therefore, it is advantageous for improving fuel efficiency and avoiding heat generation. Therefore, when the load is high such as towing or the vehicle speed is high, the direct connection fixed stage mode may be positively shifted. When the switch for selecting the motor running is operated by the driver and the motor running is selected, the independent drive EV mode is established in the region shown by the broken line.

In FIG. 18, each driving mode according to the traveling state such as vehicle speed V and vehicle load is established so that the single drive EV mode is established in the region where the vehicle load is low and the dual drive EV mode is established in the region where the vehicle load is high. Area is set. In the dual drive EV mode, based on the operating efficiency of the first rotating machine MG1 and the second rotating machine MG2 (for example, for the purpose of improving the electric cost, lowering the temperature of the rotating machines MG1 and MG2, lowering the temperature of the power control unit 50, etc.). The power sharing ratio between the first rotating machine MG1 and the second rotating machine MG2 is determined. Further, depending on the maximum output of the battery unit 52, the maximum output of the rotary machines MG1 and MG2, or the increase in the rotational speed of any of the rotating elements of the power transmission device 14 due to the increase in the vehicle speed V when the motor is running, the engine 12 is affected. When it is alleviated by driving, as shown in FIG. 18, the HV driving mode region is set in the high load region and the high vehicle speed region, and the engine 12 is used as the power source for traveling. You may move to. Further, in the region where the vehicle load is negative, the region of the independent drive EV mode is set so that the regeneration control by the second rotary machine MG2 is performed in the motor running. In the driving mode switching map in CD driving set in this way, for example, when the vehicle speed V rises, the rotation speed of each element such as the rotating machines MG1 and MG2 and the differential mechanisms 38 and 40 increases, so that in CS driving. The rotation speed of each element is controlled to be within the limit by shifting to the HV driving mode as set in the traveling mode switching map of. In the independent drive EV mode, the first rotary machine MG1 and the engine 12 are separated (that is, the power transmission between the first rotary machine MG1 and the engine 12 is cut off), so that the single drive EV mode is high. The area on the vehicle speed side may be expanded to the higher vehicle speed side than the dual drive EV mode. The regenerative control in the region where the vehicle load is negative may be changed to the dual drive EV mode instead of the single drive EV mode. Further, the drive torque and the vehicle speed V may be set to an upper limit so that the engine 12 does not start and fuel is not consumed.

By applying the vehicle speed V and the vehicle load (for example, the required drive torque) to the travel mode switching map as shown in FIG. 17 or 18, the hybrid control unit 92 determines which travel mode is established. to decide. The hybrid control unit 92 establishes the current driving mode as it is when the determined driving mode is the current driving mode, and when the determined driving mode is different from the current driving mode, the current driving mode is present. Instead of the driving mode, the determined driving mode is established.

When the independently driven EV mode is established, the hybrid control unit 92 enables motor traveling using only the second rotary machine MG2 as a power source for traveling. When the dual drive EV mode is established, the hybrid control unit 92 enables motor traveling using both the first rotating machine MG1 and the second rotating machine MG2 as power sources for traveling.

When the U / DHV mode or the O / DHV mode is established, the hybrid control unit 92 takes charge of the reaction force with respect to the power of the engine 12 by the power generation of the first rotary machine MG1, so that the engine direct torque reaches the second carrier C2. By driving the second rotary machine MG2 with the generated power of the first rotary machine MG1, torque is transmitted to the drive wheels 16 to enable the engine to run. In the U / DHV mode or the O / DHV mode, the hybrid control unit 92 has an engine operating point (that is, an engine operating point represented by an engine rotation speed Ne and an engine torque Te) in consideration of the known optimum fuel efficiency line of the engine 12. The engine 12 is operated at. In this U / DHV mode or O / DHV mode, it is also possible to drive the second rotary machine MG2 by adding the power from the battery unit 52 to the generated power of the first rotary machine MG1.

When the direct connection fixed stage mode is established, the hybrid control unit 92 enables the engine to run by directly outputting the power of the engine 12 from the second carrier C2. In the direct connection fixed stage mode, the hybrid control unit 92 drives the first rotary machine MG1 with the electric power from the battery unit 52 in addition to the power of the engine 12, and directly transfers the power of the first rotary machine MG1. It is also possible to output from the two carrier C2 or drive the second rotary machine MG2 with the electric power from the battery unit 52 and transmit the power of the second rotary machine MG2 to the drive wheels 16 to travel.

When the vehicle is stopped, the hybrid control unit 92 establishes the output shaft fixed stage mode when the battery capacity SOC is equal to or less than a predetermined predetermined capacity at which it is determined that the battery unit 52 needs to be charged. When the output shaft fixed stage mode is established, the hybrid control unit 92 takes charge of the reaction force with respect to the power of the engine 12 by the power generation of the first rotary machine MG1, and the power control unit 50 receives the generated power of the first rotary machine MG1. The battery unit 52 is charged via the above.

In both the U / DHV mode and the O / DHV mode, the first power transmission unit 20 is made to function as an electric continuously variable transmission. Further, the state in which the reduction ratio I of the first power transmission unit 20 is "1" is the same as the state in the direct connection fixed stage mode in which the clutch CL1 and the clutch CLc are both engaged (see FIG. 15). Therefore, the power transmission switching unit 94 switches between the U / DHV mode in which the clutch CL1 is engaged and the O / DHV mode in which the clutch CLc is engaged when the reduction ratio I is "1" in a synchronized state. It is executed by switching each operating state of the clutch CL1 and the clutch CLc (via a state equivalent to the direct connection fixed stage mode). Alternatively, the power transmission switching unit 94 switches between the U / DHV mode in which the clutch CL1 is engaged and the O / DHV mode in which the clutch CLc is engaged, with the clutch CL1 and the clutch CLc. It may be executed by so-called clutch-to-clutch shift control.

In the single drive EV mode, the engine 12 is brought into a rotating state by engaging the clutch CL1 or the clutch CLc. Therefore, when the engine 12 is started while the motor is running in the single drive EV mode, the hybrid control unit 92 engages the clutch CL1 or the clutch CLc, raises the engine rotation speed Ne, and ignites the engine 12. At this time, the hybrid control unit 92 may increase the engine rotation speed Ne by the first rotary machine MG1 if necessary.

Alternatively, when the engine 12 is started while the motor is running in the single drive EV mode, the hybrid control unit 92 engages the clutch CL1 or the clutch CLc with the engine rotation speed Ne at zero [rpm]. After synchronously controlling the rotation speed of each element of the differential mechanisms 38 and 40 with the first rotary machine MG1 so as to be in the same state, the clutch CL1 is engaged or the clutch CL1 is engaged or in the same state as the clutch CL1 is engaged. In the same state as when the clutch CLc is engaged, the clutch CLc is engaged, and the first rotary machine MG1 raises the engine rotation speed Ne and ignites the engine. That is, when the hybrid control unit 92 starts the engine 12 while the motor is running in the independent drive EV mode, the engaging device (clutch CL1 or clutch CLc) for establishing the standby mode is still released. Is synchronously controlled by the first rotary machine MG1 so that the rotation speed of each element of the differential mechanisms 38 and 40 is in the same state as the standby mode, and then the engaging device for establishing the standby mode is engaged. Then, the standby mode is once established, and from the state of the standby mode, the engine rotation speed Ne is raised by the first rotary machine MG1 and ignited. In this way, when the engine 12 is started while the motor is running in the single drive EV mode, the engine running may be started via the standby mode. In this case, it suffices if the standby mode (U / D input split or O / D input split) to be passed through is established in accordance with the running mode (U / DHV mode or O / DHV mode) when the engine is running.

When the engine 12 is started, the second carrier C2 connected to the drive wheels 16 receives the negative force of the engine 12 due to the increase in the rotation of the engine 12 during stoppage as a reaction force for increasing the engine rotation speed Ne. Since the torque (also called the engine pull-in torque) is transmitted, the drive torque drops. When the hybrid control unit 92 starts the engine 12 while the motor is running in the single drive EV mode, the hybrid control unit 92 compensates for a drop in the drive torque (also referred to as a reaction force cancel torque) in order to suppress a shock at the time of starting the engine. Is additionally output by the second rotary machine MG2.

In the dual drive EV mode in which the clutch CL1 and the brake BR1 are engaged, the engine 12 is brought into a rotating state by releasing the brake BR1. Therefore, when the engine 12 is started while the motor is running in the dual drive EV mode, the hybrid control unit 92 engages the clutch CLc after releasing the brake BR1 to raise the engine rotation speed Ne and ignite. At this time, the hybrid control unit 92 may increase the engine rotation speed Ne by the first rotary machine MG1 if necessary. Alternatively, when the engine 12 is started while the motor is running in the dual drive EV mode, the hybrid control unit 92 releases the brake BR1 and raises the engine rotation speed Ne by the first rotary machine MG1 to ignite. Alternatively, in the dual drive EV mode, the clutch CL1 and the brake BR1 are released to achieve the same state as the independent drive EV mode. Therefore, the clutch CL1 and the brake BR1 are released to release the engine in the single drive EV mode described above. It is also possible to start. When the engine 12 is started while the motor is running in the dual drive EV mode, the hybrid control unit 92 additionally outputs the reaction force canceling torque by the second rotary machine MG2.

By the way, in the vehicle 10 of the present embodiment, in the O / DHV mode, the change in the MG1 rotation speed Ng of the first rotary machine MG1 with respect to the change in the rotation speed of the drive wheels 16 is larger than in the U / DHV mode and the direct connection fixed stage mode. .. Therefore, when the drive wheels 16 slip (idle) and then grip (ground) while traveling in the O / DHV mode, the rotation speed of the drive wheels 16 (hereinafter, tire rotation speed Nr) decreases. At that time, there is a risk that the first rotating machine MG1 will over-rotate. Strictly speaking, the over-rotation of the first rotary machine MG1 corresponds to the fact that the MG1 rotation speed Ng enters a predetermined over-rotation region as the MG1 rotation speed Ng increases.

The mechanism by which the first rotary machine MG1 over-rotates when the drive wheels 16 are gripped after slipping while traveling in the O / DHV mode will be described with reference to the collinear diagrams of FIGS. 19 to 21. FIG. 19 is a collinear diagram showing a rotational state immediately after the drive wheels 16 have slipped while traveling in the O / DHV mode. When the drive wheels 16 slip, the load applied to the drive wheels 16 is eliminated, so that the tire rotation speed Nr increases. At this time, as shown in FIG. 19, the output rotation speed No of the output shaft 24 mechanically connected to the drive wheel 16 increases. Here, since the inertia of the engine 12 is larger than the inertia of the first rotary machine MG1, the engine rotation speed Ne hardly changes immediately after slipping, and the MG1 rotation speed Ng of the first rotary machine MG1 is the output rotation. It changes to the negative side greatly as the speed No increases.

FIG. 20 is a collinear diagram showing a rotational state when a predetermined time has elapsed since the slip occurred as shown in FIG. As shown in FIG. 20, since the load applied to the engine 12 becomes smaller, the engine rotation speed Ne increases, and the MG1 rotation speed Ng increases accordingly. In this way, the engine rotation speed Ne, the output rotation speed No, and the MG1 rotation speed Ng become high rotation speeds.

FIG. 21 is a collinear diagram showing a rotational state immediately after the grip of the drive wheels 16 (immediately after the drive wheels 16 touch the ground) from the rotational state shown in FIG. The alternate long and short dash line shown in FIG. 21 indicates the rotational state immediately before the grip. As shown in FIG. 21, when the drive wheel 16 grips, the output rotation speed No decreases with respect to the rotation state immediately before the grip indicated by the alternate long and short dash line, and the MG1 rotation speed Ng of the first rotary machine MG1 increases significantly due to the differential action. It rises to and enters the over-rotation area.

On the other hand, in the electronic control device 90, when the slip of the drive wheels 16 is predicted or the occurrence of the slip is determined while traveling in the O / DHV mode, the MG1 with respect to the change of the output rotation speed No The change in the rotation speed Ng is smaller than that in the O / DHV mode, and the mode is switched to the U / DHV mode or the direct connection fixed stage mode. In this way, when the slip of the drive wheel 16 is predicted or the occurrence of the slip is determined, the O / DHV mode or the direct connection fixed stage mode can be switched to prevent the drive wheel 16 from slipping. Over-rotation of the first rotating machine MG1 after gripping is suppressed. Hereinafter, control by the electronic control device 90 when slip occurs during traveling in the O / DHV mode will be mainly described.

The electronic control device 90 includes a traveling state determining means for determining whether the vehicle is traveling in the O / DHV mode, that is, a traveling state determining unit 96, and a road surface for determining whether the vehicle is traveling on a slippery road surface (low μ road). A determination means, that is, a road surface determination unit 98, and a slip determination means, that is, a slip determination unit 100 that determines whether or not the drive wheel 16 (tire) has slipped are further functionally provided.

The traveling state determination unit 96 determines whether the current traveling mode is the O / DHV mode. The running state determination unit 96 determines whether or not the vehicle is running in the O / DHV mode based on, for example, the engine start command signal Se or the hydraulic control command signal Sp.

The road surface determination unit 98 determines whether or not the vehicle is traveling on a slippery road surface (hereinafter referred to as a low μ road). The road surface determination unit 98 determines whether the road is a low μ road based on, for example, road surface information from a car navigation system (hereinafter, car navigation). Specifically, the road surface determination unit 98 determines that the road surface is low μ when there is road surface freezing information or snow cover information from the car navigation system with respect to the traveling road surface. There is a high possibility that the drive wheels 16 will slip while traveling on a low μ road. Therefore, the road surface determination unit 98 functions as a means for predicting the occurrence of slip of the drive wheels 16.

The slip determination unit 100 determines whether the drive wheels 16 have slipped while traveling in the O / DHV mode. The slip determination unit 100 calculates the rate of change ΔNr of the wheel speed Nr from the wheel speed Nr (tire rotation speed) of the drive wheels 16 detected by the wheel speed sensor 84, and the rate of change ΔNr is a predetermined value set in advance. Determine if it is greater than N1. Here, the predetermined value N1 is obtained experimentally or designatively in advance, and is set to a value at which it is determined that the drive wheels 16 have slipped. Therefore, when the rate of change ΔNr of the wheel speed Nr is larger than the predetermined value N1, the slip determination unit 100 determines that the drive wheels 16 have slipped.

When it is determined that the road surface during traveling is a low μ road or the rate of change ΔNr is larger than the predetermined value N1, the power transmission switching unit 94 changes the traveling mode from O / DHV mode to U / DHV mode or is directly connected. Switch to fixed stage mode. When switching to the U / DHV mode, for example, the power transmission switching unit 94 releases the clutch CLc and engages the clutch CL1. Further, when switching to the direct connection fixed stage mode, for example, the power transmission switching unit 94 engages the clutch CL1 while maintaining the engagement of the clutch CLc. Which of the U / DHV mode and the direct connection fixed stage mode is selected is appropriately selected in consideration of, for example, fuel consumption after switching and switching responsiveness.

FIG. 22 is a collinear diagram showing the rotation state when the rotation state of the O / DHV mode shown in FIG. 20 is switched to the U / DHV mode. If the drive wheels 16 slip while traveling in the O / DHV mode, the rotational state is transiently changed to the rotational state shown in FIG. When the U / DHV mode is switched from this state, the rotation state shown in FIG. 22 is obtained. Specifically, by switching to the U / DHV mode, the MG1 rotation speed Ng is lower than the MG1 rotation speed Ng in FIG. 20. Further, when the drive wheel 16 grips from the rotational state shown in FIG. 22, the rotational state shown in FIG. 23 is obtained. As shown in FIG. 23, the grip of the drive wheels 16 lowers the output rotation speed No, and at this time, the MG1 rotation speed Ng decreases. Therefore, it is suppressed that the MG1 rotation speed Ng enters the over-rotation region.

Further, even when the O / DHV mode is switched to the direct connection fixed stage mode, each rotating element of the first differential mechanism 38 and the second differential mechanism 40 is integrally rotated, and the drive wheel 16 is in this state. When gripped, the MG1 rotation speed Ng becomes the same rotation speed as the output rotation speed No as the output rotation speed No decreases. Therefore, it is suppressed that the MG1 rotation speed Ng enters the over-rotation region.

FIG. 24 is a flowchart for explaining the main part of the control operation of the electronic control device 90, that is, the control operation for suppressing the over-rotation of the MG1 rotation speed Ng when the drive wheel 16 slips while traveling in the O / DHV mode. is there. This flowchart is repeatedly executed while the vehicle is running.

First, in step S10 (hereinafter, the step is omitted) corresponding to the control function of the traveling state determination unit 96, it is determined whether or not the vehicle is traveling in the O / DHV mode (O / D input split mode). If S10 is denied, this routine is terminated. When S10 is affirmed, it is determined whether or not the vehicle is traveling on a low μ road in S20 corresponding to the control function of the road surface determination unit 98. If S20 is denied, the process proceeds to S30. On the other hand, if S20 is affirmed, it is determined that slip of the drive wheels 16 is predicted, and the process proceeds to S50.

In S30 corresponding to the control function of the slip determination unit 100, it is determined whether the rate of change ΔNr of the wheel speed Nr (tire rotation speed) is larger than the predetermined value N1. That is, in S30, it is determined whether the drive wheels 16 have actually slipped. If S30 is denied, the O / DHV mode is continuously used in S40 corresponding to the control function of the power transmission switching unit 94. On the other hand, if S30 is affirmed, the process proceeds to S50.

In S50 corresponding to the control function of the power transmission switching unit 94, the O / DHV mode can be switched to the U / DHV mode (U / D input split mode) or the direct connection fixed stage mode. In this way, by switching to the traveling mode in which the change in the MG1 rotation speed Ng with respect to the change in the rotation speed of the drive wheels 16 is small, the MG1 rotation speed Ng enters the over-rotation region when the drive wheels 16 slip and then grip. Is suppressed.

FIG. 25 is a time chart showing a control state when the drive wheels 16 are switched to the U / DHV mode when the drive wheels 16 slip while traveling in the O / DHV mode.

At the time t1 shown in FIG. 25, the tire rotation speed Nr increases as the drive wheels 16 begin to slip, and the MG2 rotation speed Nm increases accordingly, while MG1 is caused by the differential action of the second differential mechanism 40. The rotation speed Ng decreases. At the time of t2, the occurrence of slip of the drive wheels 16 is determined (tire slip determination) as the rotation of the tire rotation speed Nr increases. At the time of t3, it is determined to switch from the O / DHV mode to the U / DHV mode. Along with this, the pressure drop (drain) of the CLc oil pressure Pclc of the clutch CLc is started at the time of t3, and the pressure increase (apply) of the CL1 oil pressure Pcl1 of the clutch CL1 is started immediately before the time of t4. At the time of t4 to t5, the inertia phase is started, and at the time of t5, the switching to the U / DHV mode is completed. After switching to this U / DHV mode, the tire rotation speed Nr decreases when the drive wheels 16 grip (not shown in FIG. 25), but by switching to the U / DHV mode, the MG1 rotation speed Ng decreases. Therefore, it is suppressed that the MG1 rotation speed Ng enters the over-rotation region.

FIG. 26 is a time chart showing a control state when the drive wheels 16 are switched to the direct connection fixed stage mode when the drive wheels 16 slip while traveling in the O / DHV mode.

At the time t1 shown in FIG. 26, the tire rotation speed Nr increases as the drive wheels 16 start to slip, and the MG2 rotation speed Nm increases accordingly, while the MG1 is caused by the differential action of the second differential mechanism 40. The rotation speed Ng decreases. At the time of t2, it is determined that the drive wheels 16 slip as the tire rotation speed Nr increases. At the time of t3, it is determined to switch to the direct connection fixed stage mode. Along with this, rotation synchronization control is performed by the first rotary machine MG1, and the CL1 hydraulic Pcl1 of the clutch CL1 is increased in pressure (applied) to switch to the direct connection fixed stage mode. After switching to the direct connection fixed stage mode, the tire rotation speed Nr decreases when the drive wheel 16 grips (not shown in FIG. 26), but by switching to the direct connection fixed stage mode, the MG1 rotation speed Ng is output rotation. Since it becomes the same as the speed No, it is suppressed that the MG1 rotation speed Ng enters the over-rotation region.

As described above, according to the present embodiment, when the slip of the drive wheels 16 is predicted or the occurrence of the slip of the drive wheels 16 is determined during traveling in the O / DHV mode, the drive wheels 16 Since the change to the U / DHV mode or the direct connection fixed stage mode in which the change in the MG1 rotation speed Ng of the first rotary machine MG1 with respect to the change in the rotation speed is small is small, the over-rotation of the first rotary machine MG1 can be suppressed.

Although the examples of the present invention have been described in detail with reference to the drawings, the present invention also applies to other aspects.

For example, the vehicle 10 of the above-described embodiment has a U / DHV mode, an O / DHV mode, and a directly connected fixed stage mode, but it is not always necessary to have all of them. For example, in the above-described embodiment, it may have either a U / DHV mode or a direct connection fixed stage mode. In short, the present invention can be applied as long as it has at least two traveling modes of U / DHV mode, O / DHV mode, and direct connection fixed stage mode.

Further, in the above-described embodiment, when the slip of the drive wheels 16 is predicted or the occurrence of the slip 16 of the drive wheels is determined while traveling in the O / DHV mode, the U / DHV mode or the direct connection is performed. It was possible to switch to the fixed stage mode, but it is not necessarily limited to this. In short, when the slip of the drive wheels 16 is predicted or the occurrence of the slip 16 of the drive wheels is determined, the change in the MG1 rotation speed Ng of the first rotary machine MG1 with respect to the rotation speed of the drive wheels 16 is small. It does not matter as long as it switches to the mode. For example, when the traveling mode in which the change in the MG1 rotation speed Ng of the first rotary machine MG1 with respect to the rotation speed of the drive wheels 16 is small is the O / DHV mode, slip of the drive wheels 16 is predicted or the drive wheels are slipped. When it is determined that the slip 16 is generated, the mode is switched to the O / DHV mode. It should be noted that which of the traveling modes in which the MG1 rotation speed Ng of the first rotary machine MG1 is smaller than the rotation speed of the drive wheels 16 is determined by the connection configuration of each gear train and the gear ratios of the first differential mechanism and the second differential mechanism. Etc. to be determined in advance.

Further, in the above-described embodiment, the occurrence of slip is predicted based on whether the road surface during traveling is a low μ road, but this step is not always necessary and may be omitted.

Further, in the above-described embodiment, the clutch CL1 that selectively connects the first rotating element RE1 and the second rotating element RE2 is exemplified as the first engaging device, but the present invention is not limited to this embodiment. For example, the first engaging device may be a clutch that selectively connects the second rotating element RE2 and the third rotating element RE3, or may selectively connect the first rotating element RE1 and the third rotating element RE3. It may be a clutch. In short, the first engaging device may be a clutch that connects any two rotating elements of the first rotating element RE1, the second rotating element RE2, and the third rotating element RE3.

Further, in the above-described embodiment, a co-line diagram (FIGS. 4-FIG. 16) capable of relatively representing the rotation speeds of the rotating elements RE1-RE6 in each of the first differential mechanism 38 and the second differential mechanism 40. (See), the vertical line Y1 is the rotation speed of the fourth rotating element RE4 to which the first rotating machine MG1 is connected, and the vertical line Y2 is the rotating speed of the first rotating element RE1 to which the engine 12 is connected. Is the rotation speed of the second rotating element RE2 selectively connected to the case 18 via the brake BR1 and the rotation speed of the fifth rotating element RE5 connected to the output shaft 24, and the vertical lines Y4 are connected to each other. The rotation speeds of the third rotating element RE3 and the sixth rotating element RE6 are shown, respectively, but the present invention is not limited to this mode. For example, the vertical line Y1 vertically indicates the rotation speed of the second rotating element RE2 selectively connected to the case 18 via the brake BR1 and the rotation speed of the fourth rotating element RE4 to which the first rotating machine MG1 is connected. The line Y2 is the rotation speed of the first rotating element RE1 to which the engine 12 is connected, the vertical line Y3 is the rotation speed of the fifth rotating element RE5 connected to the output shaft 24, and the vertical line Y4 is connected to each other. The first differential mechanism and the second difference so that the rotation speeds of the rotation elements RE1-RE6 are relatively represented in the co-figure showing the rotation speeds of the third rotation element RE3 and the sixth rotation element RE6, respectively. A dynamic mechanism may be configured. In this case, the clutch CLc is a second engaging device that selectively connects the second rotating element RE2 and the fourth rotating element RE4. In this case, the U / DHV mode reverse input (reverse), which is realized with the brake BR1 engaged, cannot be established. In the U / DHV mode (forward), it is realized in the state where the clutch CL1 is engaged, in the case of low input in which the engine rotation speed Ne is input at a constant speed, and in the case where the brake BR1 is engaged. It is possible to establish the case of high input in which the engine speed Ne is increased and input.

Further, in the above-described embodiment, the engine braking is used in combination with the first traveling mode (U / DHV mode (forward), U / DHV mode forward rotation input (reverse), and U / D input split) with the clutch CL1 engaged. Mode) is established, and the engine braking in the second driving mode (O / DHV mode (forward), O / DHV mode forward input (reverse), and O / D input split) with the clutch CLc engaged. The combined mode) was established, but the present invention is not limited to this mode. For example, the first differential mechanism and the second differential are established so that the first traveling mode is established with the clutch CLc engaged and the second traveling mode is established with the clutch CL1 engaged. The mechanism may be configured.

In this case, in the co-line diagram capable of relatively representing the rotation speeds of the rotating elements RE1-RE6 in each of the first differential mechanism and the second differential mechanism, the vertical line Y1 is the first rotating machine MG1. The rotation speed of the 4th rotation element RE4 connected to each other, the vertical line Y2 is the rotation speed of the 3rd rotation element RE3 and the 6th rotation element RE6 connected to each other, and the vertical line Y3 is the case via the brake BR1. The rotation speed of the second rotation element RE2 selectively connected to 18 and the rotation speed of the fifth rotation element RE5 connected to the output shaft 24 are shown. The vertical line Y4 is the rotation speed of the first rotation element RE1 to which the engine 12 is connected. The rotation speed of each is shown. In this configuration, the clutch CLc is a second engaging device that selectively connects the second rotating element RE2 and the fifth rotating element RE5.

Alternatively, in a co-line diagram capable of relatively representing the rotation speeds of the rotating elements RE1-RE6 in each of the first differential mechanism and the second differential mechanism, the vertical line Y1 is connected to the case 18 via the brake BR1. The vertical line Y2 is the rotation speed of the second rotation element RE2 selectively connected and the rotation speed of the fourth rotation element RE4 to which the first rotation machine MG1 is connected, and the vertical line Y2 is connected to each other. And the rotation speed of the sixth rotation element RE6, the vertical line Y3 is the rotation speed of the fifth rotation element RE5 connected to the output shaft 24, and the vertical line Y4 is the rotation speed of the first rotation element RE1 to which the engine 12 is connected. Are shown respectively. In this configuration, the clutch CLc is a second engaging device that selectively connects the second rotating element RE2 and the fourth rotating element RE4.

Further, in the above-described embodiment, the first differential mechanism 38 is a double pinion type planetary gear mechanism, and the second differential mechanism 40 is a single pinion type planetary gear mechanism, but the present invention is not limited to this mode. For example, the first differential mechanism may be configured by a single pinion type planetary gear mechanism. Alternatively, the second differential mechanism may be configured by a double pinion type planetary gear mechanism. Therefore, the correspondence between the first sun gear S1, the first carrier C1, and the first ring gear R1 in the first differential mechanism and the first rotating element RE1, the second rotating element RE2, and the third rotating element RE3, and The correspondence between the second sun gear S2, the second carrier C2, and the second ring gear R2 in the second differential mechanism and the fourth rotating element RE4, the fifth rotating element RE5, and the sixth rotating element RE6 is described above. Needless to say, the correspondence is not limited to the correspondence shown by the first differential mechanism 38 and the second differential mechanism 40 in the example.

Further, in the above-described embodiment, the vehicle 10 is provided with the brake BR1, but the brake BR1 does not necessarily have to be provided. Even in the vehicle 10 not provided with the brake BR1, the independent drive EV mode, the HV driving mode, and the standby mode can be established, and the U / DHV mode and the O / DHV mode can be switched in the HV driving mode. Can be done. Further, the vehicle 10 is a gear train having a connection relationship in which the second power transmission unit 22 is arranged coaxially with the input shaft 36. For example, the second power transmission unit 22 is the axis of the input shaft 36. It may be a gear train having a connection relationship such that it is arranged on another axis. Further, although the invention has been described using the power transmission device 14 preferably used for the FR type vehicle 10, the present invention is appropriately used for the power transmission device used for vehicles of other types such as the FF type and the RR type. Can be applied.

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

10: Vehicle 12: Engine (engine)
16: Drive wheel 24: Output shaft (output rotating member)
38: First differential mechanism C1: First carrier (first rotating element)
R1: 1st ring gear (2nd rotating element)
S1: 1st sun gear (3rd rotating element)
40: 2nd differential mechanism S2: 2nd sun gear (4th rotating element)
C2: 2nd carrier (5th rotating element)
R2: 2nd ring gear (6th rotating element)
90: Electronic control device (control device)
92: Hybrid control unit CL1: Clutch (first engaging device)
CLc: Clutch (second engaging device)
MG1: 1st rotating machine MG2: 2nd rotating machine

Claims (1)

A first differential mechanism having a first rotating element, a second rotating element, and a third rotating element and connected so that an engine can transmit power, a fourth rotating element, a fifth rotating element, and a sixth rotating element. A second differential mechanism whose differential state is controlled by controlling the operating state of the first rotating machine, and a second mechanism which is connected to an output rotating member connected to a drive wheel so as to be able to transmit power. A control device for a vehicle equipped with a rotating machine.
The first rotating element is connected so that the engine can transmit power.
The third rotating element is connected to the sixth rotating element, and is connected to the sixth rotating element.
The fourth rotating element is connected to the first rotating machine so as to be able to transmit power.
The fifth rotating element is connected to the output rotating member, and is connected to the output rotating member.
The vehicle includes a first engaging device that connects any two of the first rotating element, the second rotating element, and the third rotating element, the second rotating element, and the fourth. It further includes a second engaging device for connecting the rotating element and any one of the fifth rotating elements.
The differential state of the second differential mechanism is controlled in a state where one of the first engaging device and the second engaging device is engaged, and the torque of the engine is reduced to the first. 5 A state in which the first traveling mode mechanically transmitted to the rotating element and an engaging device different from the one engaging device of the first engaging device and the second engaging device are engaged. In a second traveling mode in which the differential state of the second differential mechanism is controlled and the torque of the engine is mechanically transmitted to the fifth rotating element, the first engaging device and the second engaging device. By engaging the device, each rotating element of the first differential mechanism and the second differential mechanism is integrally rotated, and the torque of the engine is mechanically transmitted to the fifth rotating element. a third drive mode, and
When the slip of the drive wheels is predicted or the occurrence of slip of the drive wheels is determined during the travel in the first travel mode or the second travel mode, the first driving wheel with respect to the rotational speed is determined. (1) A vehicle control device including a control unit for switching to the third traveling mode in which a change in the rotation speed of the rotating machine is small.

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