JP2013141959A - Driving device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving device for vehicle capable of suppressing input of excessive torque for a one-way clutch.SOLUTION: The driving device for vehicle includes: a rotating electric machine; a first rotating element connected to the rotating electric machine; a second rotating element connected to an engine; a differential mechanism having a third rotating element connected to driving wheels; and a one-way clutch for restricting rotation of the second rotating element in the negative direction with the rotating direction during operation of the engine as the positive direction. In this case, when torque in the direction of rotation for engaging with the one-way clutch is inputted (S3-Y), rotating electric machine is controlled so that the second rotating element is rotated positively (S5, S7).

Description

  The present invention relates to a vehicle drive device.

  Conventionally, a vehicle drive device including a one-way clutch is known. For example, Patent Document 1 discloses a technique of a hybrid vehicle in which a clutch is disposed between an internal combustion engine and an output shaft, and a one-way clutch as a braking unit is disposed between the output shaft and a casing. ing.

JP-A-8-295140

  In a vehicle drive device provided with a one-way clutch, it is desirable that an excessive torque input to the one-way clutch can be suppressed.

  The objective of this invention is providing the drive device for vehicles which can suppress the input of the excessive torque with respect to a one-way clutch.

  The vehicle drive device of the present invention includes a rotating electrical machine, a first rotating element connected to the rotating electrical machine, a second rotating element connected to the engine, and a third rotating element connected to a drive wheel. A torque in the rotational direction that includes a differential mechanism and a one-way clutch that restricts the rotation of the second rotating element in the negative direction with the rotational direction during operation of the engine as a positive direction, and is engaged with the one-way clutch. The rotary electric machine is controlled so as to cause the second rotating element to rotate in the forward direction.

  The vehicle drive device further includes a clutch disposed between the engine and the one-way clutch, and the clutch is opened when the rotating electrical machine is controlled to rotate the second rotating element forward. A first control for rotating the second rotating element forward by the torque of the rotating electrical machine while the engine is stopped, and a positive direction with respect to the second rotating element by the rotating electrical machine with the clutch engaged. It is preferable that the second control for loading the torque can be executed.

  In the vehicle drive device, when the engine rotates together with the second rotation element in the second control, it is preferable to control the rotating electrical machine so that the lower limit of the engine speed is larger than zero.

  A vehicle drive device according to the present invention includes a rotating electrical machine, a first rotating element connected to the rotating electrical machine, a second rotating element connected to the engine, and a third rotating element connected to a drive wheel. A differential mechanism and a one-way clutch that restricts the rotation of the second rotation element in the negative direction with the rotation direction during engine operation as the positive direction are provided, and torque in the rotation direction to be engaged with the one-way clutch is input. When rotating, the rotating electrical machine is controlled to rotate the second rotating element in the forward direction. According to the vehicle drive device of the present invention, there is an effect that input of excessive torque to the one-way clutch can be suppressed.

FIG. 1 is a flowchart illustrating a control operation according to the embodiment. FIG. 2 is a skeleton diagram of the vehicle according to the embodiment. FIG. 3 is an alignment chart of the MG2 single drive EV mode. FIG. 4 is a collinear diagram for both drive EV modes. FIG. 5 is an alignment chart according to the first control. FIG. 6 is an alignment chart according to the second control.

  Hereinafter, a vehicle drive device according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[Embodiment]
The embodiment will be described with reference to FIGS. 1 to 6. The present embodiment relates to a vehicle drive device. FIG. 1 is a flowchart showing a control operation according to the embodiment of the present invention, and FIG. 2 is a skeleton diagram of the vehicle according to the embodiment.

  As shown in FIG. 2, the vehicle 100 includes an engine 1, a clutch 3, a one-way clutch 5, a planetary gear mechanism 10, a first rotating electrical machine MG1, a second rotating electrical machine MG2, and an ECU 50. Further, the vehicle drive device 1-1 according to the present embodiment includes the first rotating electrical machine MG1, the planetary gear mechanism 10, the clutch 3, the one-way clutch 5, and the ECU 50. The vehicle drive device 1-1 may further include the engine 1.

  The engine 1 converts the combustion energy of the fuel into a rotary motion of the rotary shaft 1a and outputs it. The engine 1 is provided with a starter 2. The starter 2 is, for example, a starter motor, and is a starting device that starts the engine 1 by rotationally driving the engine 1. The rotating shaft 1a of the engine 1 is connected to the input shaft 4 of the power transmission device via the clutch 3. The power transmission device of the present embodiment includes a one-way clutch 5, a planetary gear mechanism 10, a speed reduction mechanism having gears 15, 16, and 18, which will be described later, a differential mechanism 20, and the like.

  The clutch 3 is, for example, a friction engagement type clutch device. The clutch 3 is driven by a hydraulic actuator or the like, and can be switched between a fully engaged state, a semi-engaged state, and an opened (released) state. In the fully engaged clutch 3, the rotation speed of the input-side engagement member and the rotation speed of the output-side engagement member are synchronized, and both rotate integrally. In the clutch 3 in the half-engaged state, the input side engaging member and the output side engaging member rotate relative to each other while rotating relative to each other. In the clutch 3 of this embodiment, the slip ratio and the slip amount in the half-engaged state can be controlled. In the opened clutch 3, power transmission between the input side engaging member and the output side engaging member is interrupted. The clutch 3 of the present embodiment is controlled to a fully engaged state, a semi-engaged state, or a released state by adjusting the clutch torque capacity by the supplied hydraulic pressure.

  The input shaft 4 is connected to the carrier 14 of the planetary gear mechanism 10. The planetary gear mechanism 10 is a differential mechanism having three rotating elements. The planetary gear mechanism 10 includes a sun gear 11, a pinion gear 12, a ring gear 13, and a carrier 14. The sun gear 11 is disposed on the radially outer side of the input shaft 4. The sun gear 11 is rotatably arranged on the same axis as the input shaft 4. The ring gear 13 is rotatably arranged outside the sun gear 11 in the radial direction and coaxially with the sun gear 11. The pinion gear 12 is disposed between the sun gear 11 and the ring gear 13 and meshes with the sun gear 11 and the ring gear 13, respectively.

  The carrier 14 is arranged coaxially with the input shaft 4 and is connected to the input shaft 4, and rotates integrally with the input shaft 4. The carrier 14 is a second rotating element corresponding to the engine 1, and is connected to the engine 1 via the input shaft 4. The planetary gear mechanism 10 has a function as a power split mechanism that splits the power from the engine 1 into the output side and the first rotating electrical machine MG1, and the carrier 14 is an engine input element in the planetary gear mechanism 10. . The pinion gear 12 is rotatably supported by the carrier 14. Therefore, the pinion gear 12 can rotate (spin) around the center axis of the pinion gear 12 and rotate (revolve) around the center axis of the input shaft 4 together with the carrier 14. .

  The sun gear 11 is connected to the first rotating electrical machine MG1. The sun gear 11 is a first rotating element corresponding to the first rotating electrical machine MG1. The first rotating electrical machine MG1 includes a rotating shaft 30, a stator 31, and a rotor 32. The rotating shaft 30 of the first rotating electrical machine MG1 is disposed coaxially with the input shaft 4 and is connected to the sun gear 11. Therefore, the rotor 32 of the first rotating electrical machine MG1 rotates integrally with the sun gear 11. The first rotating electrical machine MG1 is opposed to the engine 1 in the axial direction with the planetary gear mechanism 10, the one-way clutch 5 and the clutch 3 interposed therebetween.

  In this specification, unless otherwise specified, “axial direction” indicates the direction of the central axis of the input shaft 4, “radial direction” indicates the radial direction centered on the central axis of the input shaft 4, The “circumferential direction” indicates a rotation direction around the center axis of the input shaft 4 as a rotation center.

  The ring gear 13 is connected to a counter drive gear 15 as an output gear and is a third rotating element corresponding to the drive wheel 23. The counter drive gear 15 is disposed on the engine side in the axial direction with respect to the ring gear 13, and is disposed on the radially outer side of the one-way clutch 5. The counter drive gear 15 meshes with the counter driven gear 16. Further, the counter driven gear 16 meshes with the reduction gear 21 of the second rotating electrical machine MG2. The second rotating electrical machine MG2 includes a rotating shaft 33, a stator 34, and a rotor 35. The reduction gear 21 is disposed on the rotation shaft 33 of the second rotating electrical machine MG2 and rotates integrally with the rotation shaft 33. Torque output from the second rotating electrical machine MG <b> 2 is transmitted to the counter driven gear 16 via the reduction gear 21.

  The first rotating electrical machine MG1 and the second rotating electrical machine MG2 are connected to a battery via an inverter. The first rotating electrical machine MG1 and the second rotating electrical machine MG2 can convert the electric power supplied from the battery into mechanical power and output it, and are driven by the input power to convert the mechanical power into electric power. Can be converted. The electric power generated by the first rotating electrical machine MG1 and the second rotating electrical machine MG2 can be stored in the battery. As the first rotating electrical machine MG1 and the second rotating electrical machine MG2, for example, an AC synchronous motor generator can be used.

  A drive pinion gear 18 is connected to the counter driven gear 16 via a counter shaft 17. The drive pinion gear 18 is arranged coaxially with the counter driven gear 16 and rotates integrally with the counter driven gear 16. The drive pinion gear 18 meshes with the diffring gear 19 of the differential mechanism 20. The differential mechanism 20 is connected to drive wheels 23 via left and right drive shafts 22. Accordingly, the counter drive gear 15 is connected to the drive wheel 23 via the counter driven gear 16, the drive pinion gear 18, the differential mechanism 20 and the drive shaft 22. The second rotating electrical machine MG2 is disposed closer to the drive wheel 23 than the counter drive gear 15 and is connected to the power transmission path closer to the drive wheel 23 than the counter drive gear 15 so that torque can be output.

  The ECU 50 is an electronic control unit having a computer. The ECU 50 has a function as a control device that controls each part of the vehicle 100. For example, the ECU 50 is communicably connected to the engine 1, the clutch 3, the first rotating electrical machine MG1, and the second rotating electrical machine MG2, and the engine 1, the clutch 3, the first rotating electrical machine MG1, and the second rotating electrical machine MG2 are connected. Can be controlled.

  The one-way clutch 5 is provided on the input shaft 4. Therefore, the clutch 3 is disposed between the engine 1 and the one-way clutch 5. The one-way clutch 5 restricts the rotation of the input shaft 4 and the carrier 14 in the negative direction. Here, in the rotational direction of the input shaft 4 and the carrier 14, the positive direction is the rotational direction of the input shaft 4 and the carrier 14 when the engine 1 is operating. In other words, the rotation direction of the ring gear 13 when the vehicle 100 travels forward is the positive direction. The one-way clutch 5 allows the input shaft 4 and the carrier 14 to rotate in the positive direction and restricts the rotation in the negative direction. The one-way clutch 5 can be a sprag type in which a sprag is disposed between an inner ring and an outer ring, for example. The one-way clutch 5 has an inner ring connected to the input shaft 4 and an outer ring connected to the vehicle body, for example, a case of a power transmission device.

  In this specification, the state where the one-way clutch 5 restricts the rotation of the input shaft 4 in the negative direction is described as the engagement state of the one-way clutch 5, and the one-way clutch 5 allows the input shaft 4 to rotate in the positive direction. The state in which the one-way clutch 5 is released is described.

  The vehicle 100 is a hybrid vehicle and can selectively execute EV traveling or HV traveling. The EV travel is a travel mode in which the vehicle 100 travels using at least one of the first rotating electrical machine MG1 and the second rotating electrical machine MG2 as a power source regardless of the power of the engine 1. The vehicle 100 according to the present embodiment can not only use the second rotating electrical machine MG2 as a power source during EV traveling but also use the first rotating electrical machine MG1 as a power source. The EV traveling mode in which the second rotating electrical machine MG2 travels using a single power source is referred to as an “MG2 single drive EV mode”, and the EV traveling mode in which the first rotating electrical machine MG1 and the second rotating electrical machine MG2 are used as a power source is referred to as “MG1 & MG2. This is referred to as “both drive EV mode” or simply “both drive EV mode”.

  FIG. 3 is an alignment chart of the MG2 single drive EV mode, and FIG. 4 is an alignment chart of the both drive EV mode. In each collinear diagram, the left axis is the rotation of the sun gear 11 and the first rotary electric machine MG1, the central axis is the rotation of the carrier 14 and the engine 1, and the right axis is the rotation of the ring gear 13 and the second rotary electric machine MG2. Each is shown.

  In the MG2 single drive EV mode shown in FIG. 3, the vehicle 100 is caused to travel by the driving force generated by the second rotating electrical machine MG2, and the first rotating electrical machine MG1 is in an idling state, for example. During EV travel, the clutch 3 is released, but EV travel is possible even when the clutch 3 is engaged. In the case of EV traveling with the clutch 3 in the disengaged state, the drag loss of the first rotating electrical machine MG1 is controlled by controlling the rotational speed of the first rotating electrical machine MG1 to a low speed (for example, rotational speed 0) in the MG2 single drive EV mode. It is possible to reduce. Further, when the clutch 3 is disengaged during EV traveling, there is an advantage that torque fluctuations when starting the engine 1 are not transmitted to the drive system.

  In the double drive EV mode shown in FIG. 4, vehicle 100 is caused to travel by the driving force generated by first rotating electrical machine MG1 and second rotating electrical machine MG2. In this case, the first rotating electrical machine MG1 can output a driving force in the forward direction to the driving wheels 23 by negatively rotating and generating negative torque. Negative torque is input to the carrier 14 by the negative torque of the first rotating electrical machine MG1. The one-way clutch 5 enters an engaged state with respect to the input negative torque and restricts negative rotation of the input shaft 4 and the carrier 14. In other words, the one-way clutch 5 receives a reaction force against the negative torque of the first rotating electrical machine MG1, and causes the ring gear 13 to output a positive torque. As a result, the driving force by the first rotating electrical machine MG <b> 1 is output from the ring gear 13 toward the driving wheels 23.

  As described above, the vehicle 100 is mounted with the input split type HV system having the EV traveling mode in which the one-way clutch 5 is locked (engaged) and both are driven by the two rotating electric machines MG1 and MG2. The double drive EV mode increases the driving force during EV travel and improves the performance compared to the MG2 single drive EV mode. On the other hand, securing the strength of the one-way clutch 5 that fixes the carrier 14 as an engine input element becomes a problem. For example, an excessive torque may be input to the one-way clutch 5 due to torque fluctuation during sudden braking.

  In the vehicle drive device 1-1 of the present embodiment, excessive input suppression control that suppresses excessive input to the one-way clutch 5 is performed. Specifically, when the input to the one-way clutch 5 becomes excessive, the first rotating electrical machine MG1 is controlled so as to rotate the carrier 14 forward. In the present embodiment, for example, excessive input suppression control is performed in a situation where there is a possibility that the input to the one-way clutch 5 may be excessive. In the present embodiment, a situation where the input to the one-way clutch 5 may be excessive is a situation where torque in the rotational direction for engaging the one-way clutch 5 with the one-way clutch 5 is input. The torque in the rotational direction for engaging the one-way clutch 5 is the torque in the rotational direction for negatively rotating the carrier 14.

  When the magnitude of torque input to the one-way clutch 5 can be predicted or estimated, excessive input suppression control is performed when it is predicted that excessive torque will be input to the one-way clutch 5 based on the predicted torque or estimated torque. You may do it. In this case, for example, the excessive input suppression control may be executed when the magnitude of the torque in the engagement direction input to the one-way clutch 5 is a predetermined value or more.

  In the excessive input suppression control, the ECU 50 causes the first rotating electrical machine MG1 to generate a positive torque and loads the carrier 14 with the positive torque. This positive torque is a torque in the rotational direction for releasing the one-way clutch 5. Thereby, it is suppressed that an excessive negative torque is applied to the one-way clutch 5.

  When the vehicle drive device 1-1 controls the first rotating electrical machine MG1 so as to rotate the carrier 14 in the forward direction, the clutch 14 is released and the carrier 14 is driven by the torque of the first rotating electrical machine MG1 while the engine 1 is stopped. And the second control for applying a positive torque to the carrier 14 by the first rotating electrical machine MG1 while the clutch 3 is engaged. Thereby, when an excessive torque input to the one-way clutch 5 is predicted, the excessive input can be suppressed regardless of whether the clutch 3 is in the engaged state or the released state.

  Note that controlling the first rotating electrical machine MG1 so as to rotate the carrier 14 forward indicates that the first rotating electrical machine MG1 outputs torque in the direction in which the carrier 14 is normally rotated. At this time, the magnitude of the torque of the first rotating electrical machine MG1 (for example, the command value of the output torque) is preferably a magnitude that can actually rotate the carrier 14 forward, but the carrier 14 is rotated forward. It does not have to be small enough. Even if the torque is less than the magnitude that allows the carrier 14 to rotate forward, at least the torque in the engagement direction input to the one-way clutch 5 can be reduced. The excessive input suppression control will be described with reference to FIG.

  In step S1, the ECU 50 determines whether the engine is stopped and the one-way clutch 5 is engaged. The ECU 50 can make the determination in step S1 based on, for example, the engine speed and the rotational speed of the input shaft 4. As a result of the determination in step S1, if it is determined that the engine is stopped and the one-way clutch 5 is engaged (step S1-Y), the process proceeds to step S2, and if not (step S1-N) This control flow ends.

  In step S2, the ECU 50 predicts data acquisition and excessive torque input of the one-way clutch 5. The ECU 50 acquires data that can predict the input of excessive torque to the one-way clutch 5. ECU50 acquires the brake signal and vehicle speed of a wheel, for example. The ECU 50 predicts an input of excessive torque due to sudden braking based on the brake signal and the vehicle speed. Specifically, it can be predicted that an excessive torque is input to the one-way clutch 5 when a wheel brake ON signal is detected and the absolute value of the vehicle speed is greater than a predetermined vehicle speed. Here, the predetermined vehicle speed can be a low vehicle speed other than 0, for example. The predetermined vehicle speed may be, for example, a vehicle speed on the order of slow speed. If a wheel brake ON signal is detected during traveling at a vehicle speed above a certain level, sudden braking may be performed. In this case, the one-way clutch 5 can be protected by reducing the magnitude of the input torque to the one-way clutch 5 in advance by the first rotating electrical machine MG1.

  It should be noted that the wheel brake ON state is a situation where the driver desires braking of the vehicle 100, and there is no need to drive both the first rotating electrical machine MG1 and the second rotating electrical machine MG2. That is, the first rotating electrical machine MG1 can perform control to reduce the transmission torque of the one-way clutch 5 instead of functioning as a drive source of the vehicle 100. When step S2 is executed, the process proceeds to step S3.

  In step S3, the ECU 50 determines whether or not there is a possibility of excessive torque input. The ECU 50 can make an affirmative determination in step S3 when a wheel brake ON signal is detected and the absolute value of the vehicle speed is greater than a predetermined vehicle speed. As a result of the determination in step S3, if it is determined that there is a possibility of excessive torque input (step S3-Y), the process proceeds to step S4, and if not (step S3-N), the control flow ends.

  In step S4, the ECU 50 determines whether or not the engine disconnecting clutch 3 is being released. The ECU 50 can make the determination in step S4 based on, for example, the hydraulic pressure command value for the clutch 3 or the difference in rotational speed before and after the clutch 3, in other words, the rotational speed difference between the input side and the output side. As a result of the determination in step S4, if it is determined that the engine disconnecting clutch 3 is disengaged (step S4-Y), the process proceeds to step S5, and if not (step S4-N), the process proceeds to step S7.

  In step S5, the ECU 50 applies a positive torque to the carrier 14 by the first rotating electrical machine MG1. In step S5, the first control of excessive input suppression control is performed. The first rotating electrical machine MG1 outputs a positive torque and loads the carrier 14 with the positive torque.

  In step S6, the rotation speed of the carrier 14 as an engine input element increases. FIG. 5 is an alignment chart according to the first control. Since the clutch 3 is being disengaged, when a positive torque is output from the first rotating electrical machine MG1 in step S5, the carrier 14 rotates forward. That is, the one-way clutch 5 is released by the positive torque of the first rotating electrical machine MG1. The ECU 50 controls the first rotating electrical machine MG1 so as to increase the rotational speed of the carrier 14 to the target rotational speed. This target rotational speed is determined so that the one-way clutch 5 is not engaged even if torque fluctuation occurs due to sudden braking or the like. In the first control, since the clutch 3 is released and the engine 1 is disconnected, the first rotating electrical machine MG1 can increase the rotational speed of the carrier 14 with a small torque. Therefore, the power of the first rotating electrical machine MG1 can be reduced, and fuel consumption / electricity cost can be improved. Further, since the inertia of the carrier 14 is disconnected, amplification of the vibration torque is suppressed.

  Since the one-way clutch 5 is opened, even if torque fluctuation due to sudden braking or the like is input, the load on the one-way clutch 5 due to the torque fluctuation is reduced. For example, even if torque fluctuation is input, the one-way clutch 5 is suppressed from being engaged. Therefore, an excessive negative torque in the engaging direction is suppressed from acting in a state where the one-way clutch 5 is engaged. When step S6 is executed, the control flow ends.

  When a negative determination is made in step S4 and the process proceeds to step S7, in step S7, the ECU 50 reduces the clutch torque capacity and applies a positive torque load by the first rotating electrical machine MG1. In step S7, the second control of the excessive input suppression control is performed. The ECU 50 reduces the clutch torque capacity of the clutch 3. Specifically, the ECU 50 reduces the hydraulic pressure supplied to the clutch 3 and reduces the pressing force in the direction in which the clutch 3 is engaged. In the present embodiment, the ECU 50 reduces the clutch torque capacity of the clutch 3 by a command to release the clutch 3. In this case, for example, the supply hydraulic pressure may be reduced at the maximum speed.

  The ECU 50 reduces the clutch torque capacity of the clutch 3 and causes the first rotating electrical machine MG1 to output a positive torque. The positive torque of the first rotating electrical machine MG1 acts as torque in a direction in which the one-way clutch 5 is released and the carrier 14 is rotated. When step S7 is executed, the process proceeds to step S8.

  In step S <b> 8, any one of (1) input element stop, (2) input element rotation, and (3) input element rotates together with the engine 1 is set. FIG. 6 is an alignment chart according to the second control. The input element stop (1) indicates a state in which the rotation of the carrier 14 and the engine 1 is stopped as shown in FIG. The input element rotation (2) indicates a state where the carrier 14 is rotating and the engine 1 is stopped. The rotation of the input element (3) together with the engine 1 indicates a state in which the carrier 14 and the engine 1 rotate. In the case of (3), not only the state where the carrier 14 and the engine 1 rotate at the same rotation speed but also the state where the carrier 14 and the engine 1 rotate relative to each other are included. In other words, in the state of (3), the carrier 14 and the engine 1 are rotated with the clutch 3 fully engaged, and the carrier 14 and the engine 1 are rotated with the clutch 3 partially engaged. Is included.

  Which of these states (1) to (3) is reached is based on, for example, the clutch torque capacity of the clutch 3 and the magnitude of the positive torque of the first rotating electrical machine MG1. When the positive torque of the first rotating electrical machine MG1 is small and the clutch torque capacity of the clutch 3 is large, (1) the input element is stopped. In the state (1), although the one-way clutch 5 is engaged, the torque load (transmission torque) of the one-way clutch 5 is reduced by inputting the positive torque of the first rotating electrical machine MG1. For this reason, even if torque fluctuation due to sudden braking or the like occurs, the torque load on the one-way clutch 5 due to the torque fluctuation is reduced.

  When the clutch torque capacity of the clutch 3 is small, (2) the input element rotates. When the clutch torque capacity is small, the carrier 14 and the engine 1 can rotate relative to each other. Here, the state (2) includes a state where the clutch 3 is half-engaged and a state where the clutch 3 is released. When the clutch 3 is half-engaged, (2) the input element is rotated when the clutch torque capacity is smaller than the torque capable of rotating the engine 1. (2) In the input element rotation state, the carrier 14 rotates and the one-way clutch 5 is released. For this reason, even if torque fluctuation due to sudden braking or the like occurs, the engagement of the one-way clutch 5 is suppressed, and the torque load of the one-way clutch 5 is reduced.

  When the clutch torque capacity of the clutch 3 is large and the positive torque of the first rotating electrical machine MG1 is large, (3) the input element is rotated together with the engine 1. The engine 1 is rotated by the positive torque transmitted from the carrier 14 side to the engine 1 side via the clutch 3. That is, the clutch torque capacity in the state of (3) is a magnitude that can transmit the torque that rotates the engine 1, and the positive torque of the first rotating electrical machine MG1 is a magnitude that can rotate the carrier 14 and the engine 1. That's it. (3) When the input element rotates together with the engine 1, the one-way clutch 5 is released. For this reason, even if torque fluctuation due to sudden braking or the like occurs, the engagement of the one-way clutch 5 is suppressed, and the torque load of the one-way clutch 5 is reduced. When step S8 is executed, the control flow ends.

  Further, the ECU 50 of the present embodiment controls the engine speed when the state (3) is reached. Specifically, the target value of the engine speed is set such that the lower limit is a value that does not result in zero rotation due to rotational fluctuations, and the upper limit is a value that is equal to or less than the resonance speed of the torsional resonance of the drive system. When the engine 1 is rotated by the positive torque of the first rotating electrical machine MG1, the engine speed may vary. The ECU 50 controls the engine speed by the first rotating electrical machine MG1 so that the engine speed becomes a value larger than 0 even if the rotational fluctuation occurs. As a result, the engagement of the one-way clutch 5 is suppressed and the released state is maintained, whereby the input of excessive torque to the one-way clutch 5 is suppressed.

  Further, the ECU 50 controls the engine rotational speed by the first rotating electrical machine MG1 so that the engine rotational speed is equal to or lower than the resonant rotational speed of torsional resonance of the drive system even if rotational fluctuation occurs. Here, the drive system includes, for example, the engine 1, the first rotating electrical machine MG1, and a damper disposed between the engine 1 and the first rotating electrical machine MG1, and the resonance rotational speed is determined by the engine 1-damper. -It can be set as the resonant rotation speed of the first rotating electrical machine MG1 system. By setting the upper limit rotational speed of the rotational fluctuation to be equal to or lower than the resonant rotational speed of the drive system, it is advantageous in terms of suppressing noise and vibration due to resonance and ensuring strength.

  As described above, the vehicle drive device 1-1 of the present embodiment sets the first rotating electrical machine MG <b> 1 so that the rotational speed of the carrier 14 becomes positive when an excessive torque input to the one-way clutch 5 is predicted. Control or load the torque of the first rotating electrical machine MG1 in the direction in which the rotational speed of the carrier 14 becomes positive. Thereby, an excessive input to the one-way clutch 5 is suppressed. The vehicle drive device 1-1 may include a torque limiter mechanism or a friction clutch / brake having a torque limiter mechanism instead of the clutch 3. Even in such a vehicle drive device 1-1, when the excessive torque input to the one-way clutch 5 is predicted, the one-way clutch is controlled by controlling the first rotating electric machine MG1 so that the rotation speed of the carrier 14 becomes positive. An excessive input to 5 can be suppressed.

  Note that the friction clutch / brake having the torque limiter mechanism and the torque limiter mechanism is not limited to the position of the clutch 3 and may be connected to another rotating element of the planetary gear mechanism 10. Even if the torque limiter mechanism is provided, the torque limiter mechanism does not work when the one-way clutch 5 is locked, and an excessive torque may be input to the one-way clutch 5. There is a method to cope with this by increasing the capacity of the one-way clutch 5, but this causes an increase in cost. On the other hand, according to the vehicle drive device 1-1 of the present embodiment, excessive torque input to the one-way clutch 5 can be suppressed even when the torque limiter mechanism does not work. Since the existing first rotating electrical machine MG1 is used and handled by control without changing the hardware configuration, an increase in T / A size can be avoided.

  In the present embodiment, the first rotating element connected to the first rotating electrical machine MG1 is the sun gear 11, the second rotating element connected to the engine 1 is the carrier 14, and the third rotating element connected to the drive wheel 23 is the ring gear. Although it was 13, it is not limited to this. Corresponding relationships among the first rotating element, the second rotating element, and the third rotating element, and the sun gear 11, the carrier 14, and the ring gear 13 can be arbitrarily determined.

  In the present embodiment, the differential mechanism having the first rotating element, the second rotating element, and the third rotating element is a planetary gear mechanism. However, the present invention is not limited thereto, and other differential mechanisms may be used. Good.

[First Modification of Embodiment]
A first modification of the embodiment will be described. In the above embodiment, an excessive input to the one-way clutch 5 is predicted based on the wheel brake ON signal and the vehicle speed, but instead, an excessive input may be predicted based on the brake operation amount and the vehicle speed. The brake operation amount can be, for example, a brake stroke, a master cylinder pressure, or a rate of change thereof. For example, when a brake operation is detected based on the brake operation amount and the absolute value of the vehicle speed is greater than a predetermined vehicle speed, it can be determined that there is a possibility of excessive input.

  Alternatively, when the brake operation amount is equal to or greater than a predetermined value and the absolute value of the vehicle speed is greater than the predetermined vehicle speed, it can be determined that there is a possibility of excessive input. In this way, it is possible to detect only sudden braking and execute the first control or the second control only in the case of sudden braking. By preventing the first control and the second control from being executed except during sudden braking, deterioration of fuel consumption can be suppressed.

  An excessive input may be predicted based on the shift position and the vehicle speed. For example, based on the detection result of the shift position sensor, when a P range signal or an N range signal is detected and the absolute value of the vehicle speed is greater than a predetermined vehicle speed, it can be determined that there is a possibility of excessive input. . If the parking gear is engaged by shifting to the P range during traveling, excessive torque may be input to the one-way clutch 5. By executing the first control or the second control based on the detection of the P range signal or the N range signal, excessive input suppression can be executed at an early stage.

  Excessive input may be predicted based on wheel speed fluctuations or rotation fluctuations of the rotating electrical machines MG1, MG2. As a result, it is possible to suppress excessive input by detecting fluctuations in the wavy road and the road surface μ. When the wheel speed or the rotational speed of the rotating electrical machines MG1 and MG2 varies due to the fluctuation of the wavy road or the road surface μ, the first control or the second control is executed to suppress excessive input due to the subsequent fluctuation of the rotational speed. be able to. For example, it is determined that there is a possibility of excessive input when the absolute value of the fluctuation amount of the wheel speed and the absolute value of the fluctuation rate, and the fluctuation amount of the rotational speed of the rotating electrical machines MG1 and MG2 and the absolute value of the fluctuation rate are equal to or greater than a predetermined value. it can.

  An excessive input may be predicted based on the shift position and the vehicle front-rear direction inclination. For example, if the parking lock mechanism is released on a slope with a large forward / backward inclination, torque fluctuation may occur when the parking gear is released, and an excessive torque may be input to the one-way clutch 5. For example, it may be determined that there is a possibility of excessive input when the P range signal is OFF and the magnitude of the vehicle front-rear direction inclination is larger than a predetermined value. By executing the first control or the second control based on the P range signal, it is possible to execute excessive input suppression at an early stage. In particular, when combined with shift-by-wire, it is effective if the excessive input suppression control and the parking cancellation are sequentially performed. For example, if the parking lock mechanism is released after the one-way clutch 5 is released by the first control or the second control, it is possible to more reliably suppress excessive input.

[Second Modification of Embodiment]
In the above embodiment, the positive torque is applied to the carrier 14 by the first rotating electrical machine MG1 in the excessive input suppression control, but instead, the positive torque is output to the carrier 14 by the second rotating electrical machine MG2. Also good. Arrangement | positioning of 2nd rotary electric machine MG2 is not limited to what was illustrated. For example, the second rotary electric machine MG2 may be arranged to output torque to the ring gear 13. As an example, the second rotating electrical machine MG2 may be arranged so that the reduction gear 21 meshes with the counter drive gear 15.

[Third Modification of Embodiment]
In the second control of the above embodiment, a positive torque may be applied to the carrier 14 by the starter 2. For example, when the second control is executed by the excessive input suppression control, the first rotating electrical machine MG1 may output a positive torque and the starter 2 may output a positive torque. In this way, the release timing of the one-way clutch 5 can be advanced. Alternatively, after the start of the second control, (1) While the input element is stopped, in other words, while the one-way clutch 5 is engaged, the starter 2 may output a positive torque.

  The contents disclosed in the above embodiments and modifications can be executed in appropriate combination.

1-1 Vehicle Drive Device 1 Engine 3 Clutch 5 One-way Clutch 10 Planetary Gear Mechanism 11 Sun Gear 12 Pinion Gear 13 Ring Gear 14 Carrier 23 Drive Wheel 50 ECU
MG1 First rotating electrical machine (Rotating electrical machine)
MG2 Second rotating electrical machine

Claims (3)

Rotating electrical machinery,
A differential mechanism having a first rotating element connected to the rotating electrical machine, a second rotating element connected to the engine, and a third rotating element connected to drive wheels;
A rotation direction during operation of the engine as a positive direction, and a one-way clutch that restricts rotation in the negative direction of the second rotation element, and when torque in the rotation direction to be engaged with the one-way clutch is input In addition, the rotating electrical machine is controlled so as to rotate the second rotating element in the forward direction. Furthermore, a clutch disposed between the engine and the one-way clutch is provided,
When controlling the rotating electrical machine so as to rotate the second rotating element in the forward direction, the first control is performed such that the clutch is released and the second rotating element is rotated forward by the torque of the rotating electrical machine while the engine is stopped. 2. The vehicle drive device according to claim 1, wherein second control for applying a positive torque to the second rotating element by the rotating electrical machine in a state where the clutch is engaged can be executed. 3. The vehicle drive device according to claim 2, wherein when the engine rotates together with the second rotation element in the second control, the rotating electrical machine is controlled so that a lower limit of the engine speed is larger than zero.

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