JP2010195102A - Driving device of hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device of a hybrid vehicle which is valid for miniaturization by directly connecting the output shaft of an internal combustion engine with the output shaft of a revolving armature. <P>SOLUTION: The driving device 1A of the hybrid vehicle includes: an internal combustion engine 2; a first MG 3; an output gear 6 for outputting a power to a driving wheel 12 of the vehicle; and a planetary gear mechanism 20. In the driving device 1A, an output shaft 2a of the internal combustion engine 2 is connected to a carrier C of the planetary gear mechanism 20 through a damper 13, an output shaft 3a of the first MG 3 is connected to a sun gear S of the planetary gear mechanism 20, and an output gear 6 is connected to a ring gear R of the planetary gear mechanism 20. The driving device 1A includes: a second MG 4; and a connection switching device 21 for selectively connecting the output shaft 4a of the second MG 4 to either the output shaft 2a of the internal combustion engine 2 or the ring gear R. In the driving device 1A, the connection switching device 21 connects the output shaft 4a of the second MG 4 to the output shaft 2a of the internal combustion engine 2 so that the output shaft 4a of the second MG 4 can be directly connected to the output shaft 2a of the internal combustion engine 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive device for a hybrid vehicle in which an output shaft of an internal combustion engine is connected to a rotating element of a differential mechanism via a damper.

  A hybrid comprising an internal combustion engine, a plurality of rotating electric machines, and a differential mechanism having a plurality of rotating elements that can be differentially connected to each other, wherein the output shaft of the internal combustion engine and the output shafts of the rotating electric machines are connected to different rotating elements. Vehicle drive devices are known. In such a drive device, the output shaft of the internal combustion engine is connected to the rotating element of the differential mechanism via a damper for absorbing torque fluctuations of the internal combustion engine. Therefore, when the rotation of the rotating electrical machine is transmitted from the differential mechanism to the internal combustion engine, the rotation is transmitted via the damper. On the other hand, when the output shaft of the internal combustion engine is driven to rotate by the rotating electrical machine, it is desirable that the output shaft of the internal combustion engine is directly connected to the output shaft of the rotating electrical machine in consideration of the accuracy of the rotational speed control. Therefore, as a drive device mounted on the hybrid vehicle, the output shaft of the internal combustion engine is connected to the first rotating element via a damper, the first rotating electrical machine is connected to the second rotating element, and the third rotating element is connected. A differential mechanism having a drive shaft connected to an element, a second rotating electrical machine connected to the driving shaft, and a third rotating electrical machine connected to the output shaft of the internal combustion engine without a damper. It is known (see Patent Document 1). In addition, there are Patent Documents 2 and 3 as prior art documents related to the present invention.

JP 2004-336983 A JP 2002-135910 A JP-A-11-205907

  In the apparatus of Patent Document 1, since a third rotating electric machine is required in addition to the first and second rotating electric machines connected to the differential mechanism and the drive shaft, the apparatus may be increased in size.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a drive device for a hybrid vehicle that can directly connect an output shaft of an internal combustion engine to an output shaft of a rotating electrical machine and is advantageous for downsizing.

  A drive device for a hybrid vehicle of the present invention includes a differential mechanism having an internal combustion engine, a first rotating electrical machine, an output member for outputting power to the drive wheels of the vehicle, and three rotational elements that can be differentiated from each other. The output shaft of the internal combustion engine is connected to the first rotating element of the differential mechanism via a damper, and the output shaft of the first rotating electrical machine is connected to the second rotating element of the differential mechanism. In the hybrid vehicle drive device in which the output member is connected to the third rotating element of the differential mechanism, the second rotating electrical machine and the output shaft of the second rotating electrical machine are the output shaft of the internal combustion engine or the second rotating electrical machine. Connection switching means for switching the connection destination of the output shaft of the second rotating electrical machine so as to be selectively connected to any one of the three rotating elements, and the connection switching means outputs the output of the second rotating electrical machine The shaft and the output shaft of the internal combustion engine are directly By connecting the output shaft of the second rotary electric machine so as to continue the output shaft of the internal combustion engine, to solve the problems described above (claim 1).

  According to the drive device of the present invention, the output switching shaft of the internal combustion engine and the output shaft of the second rotating electrical machine can be directly connected by the connection switching means. Therefore, when the internal combustion engine is rotationally driven by the second rotating electrical machine, the control accuracy of the rotational speed of the internal combustion engine can be improved. Further, since the output shaft of the internal combustion engine is connected to the first rotating element via the damper, the torque fluctuation of the internal combustion engine can be absorbed by the damper when the power of the internal combustion engine is transmitted to the differential mechanism. In the drive device of the present invention, since the second rotating electrical machine is connected to the output shaft of the internal combustion engine, it is not necessary to provide a rotating electrical machine in addition to the first rotating electrical machine and the second rotating electrical machine. Therefore, the apparatus can be reduced in size.

  In one form of the hybrid vehicle drive device of the present invention, the second rotating electrical machine has a larger output than the first rotating electrical machine, and the first rotating electrical machine and the second rotating electrical machine are connected to the output shaft of the internal combustion engine. The second rotating electrical machine may be disposed on the side of the internal combustion engine with respect to the first rotating electrical machine. By disposing the second rotating electrical machine having a large output close to the internal combustion engine in this way, the distance of the power transmission path when connecting the output shaft of the second rotating electrical machine and the output shaft of the internal combustion engine can be shortened. . Therefore, when the rotational speed of the internal combustion engine is controlled by the second rotating electrical machine, the control accuracy of the rotational speed control can be improved.

  In one form of the hybrid vehicle drive device of the present invention, the internal combustion engine is a fuel cut in which fuel supply is stopped when the speed of the vehicle is equal to or higher than a predetermined determination speed and the accelerator pedal is not depressed. When the fuel cut control is being executed for the internal combustion engine, the connection switching means is connected so that the output shaft of the second rotating electrical machine is connected to the output shaft of the internal combustion engine. The second rotating electrical machine controls the operation, and the output shaft of the internal combustion engine is rotationally driven at a predetermined rotational speed, and fluctuations in the rotational speed of the output shaft of the internal combustion engine that occur during the rotational drive are offset. Control means for controlling the operation may be further provided (claim 3). When the supply of fuel to the internal combustion engine is stopped and the internal combustion engine is rotationally driven by the rotating electric machine in this state, the rotational speed fluctuation due to the pumping loss occurs. And this rotational speed fluctuation | variation tends to become large when the internal combustion engine is rotationally driven at a low speed. Therefore, when the internal combustion engine is rotationally driven by the rotating electrical machine in this way, the rotating electrical machine is controlled so as to cancel out the rotational speed fluctuation generated at that time. Accordingly, the internal combustion engine can be driven to rotate at a low speed while suppressing the vibration of the vehicle. Moreover, since the rotational speed of the internal combustion engine can be kept low, the energy consumed by the second rotating electrical machine for rotationally driving the internal combustion engine can be reduced.

  As described above, according to the hybrid vehicle drive device of the present invention, the output shaft of the internal combustion engine connected via the rotary element of the differential mechanism and the damper is connected to the output of the second rotating electrical machine by the connection switching means. Can be connected directly to the shaft. Further, since the second rotating electrical machine is connected to the output shaft of the internal combustion engine, the apparatus can be reduced in size.

The figure which shows the outline of the drive device which concerns on the 1st form of this invention. The flowchart which shows the switching control routine which MGCU of FIG. 1 performs. The figure which shows the outline of the drive device which concerns on the 2nd form of this invention.

(First form)
FIG. 1 shows a schematic diagram of a driving apparatus according to the first embodiment of the present invention. This drive device 1A is mounted on a hybrid vehicle, and is an internal combustion engine (hereinafter sometimes referred to as an engine) 2 and a first motor generator (hereinafter simply referred to as a first MG) as a first rotating electrical machine. 3) and a second motor generator (hereinafter sometimes abbreviated as second MG) 4 as a second rotating electrical machine. As shown in this figure, the first MG 3 and the second MG 4 are provided coaxially with the output shaft 2 a of the engine 2. The first MG3 and the second MG4 function as an electric motor and a generator, and may be the same as well-known ones mounted on a hybrid vehicle, and thus detailed description thereof is omitted. The second MG4 has a larger output and a larger physique than the first MG3. Since the engine 2 may be the same as a known one mounted on a hybrid vehicle, detailed description thereof is omitted. The engine 2, the first MG 3, and the second MG 4 are connected to the power distribution mechanism 5. The power distribution mechanism 5 switches the connection state of the engine 2, the first MG3, and the second MG4, and switches the transmission destination of the power output from the engine 2, the first MG3, and the second MG4. An output gear 6 as an output member for outputting power to the drive wheels 12 is connected to the power distribution mechanism 5. In a power transmission path from the power distribution mechanism 5 to the drive wheel 12, a counter shaft 9 provided so that the counter gear 7 and the drive gear 8 rotate integrally, and a differential mechanism 10 to which the rotation of the drive gear 8 is transmitted. And a drive shaft 11 are provided. The counter shaft 9 is provided so that the counter gear 7 meshes with the output gear 6. Therefore, the power output from the power distribution mechanism 5 is transmitted to the differential mechanism 10 via the output gear 6, the counter gear, the counter shaft 9, and the drive gear 8. The power transmitted to the differential mechanism 10 is then transmitted to the drive wheels 12 via the drive shaft 11.

  The power distribution mechanism 5 includes a planetary gear mechanism 20 as a differential mechanism and a connection switching device 21 as a connection switching means for switching the connection destination of the output shaft 4a of the second MG4. The planetary gear mechanism 20 includes a sun gear S that can rotate about an axis CL, a plurality of planetary gears (planetary gears) P that revolve around the sun gear S and mesh with the sun gear S, and are arranged coaxially with the sun gear S. A ring gear R that meshes with each other and a carrier C that rotatably supports each planetary gear P around the axis CL of the sun gear S are provided. As shown in FIG. 1, the output shaft 3a of the first MG 3 is connected to the sun gear S so as to rotate integrally. The output shaft 2 a of the engine 2 is connected to the carrier C via a damper 13. Since the damper 13 may be a known one for absorbing torque fluctuations of the engine 2, a detailed description thereof will be omitted. Since the planetary gear mechanism 20 is connected to the output shaft 2a of the engine 2 and the output shaft 3a of the first MG 3 in this way, the sun gear S corresponds to the second rotating element of the present invention, and the carrier C corresponds to the first rotation of the present invention. Corresponds to the element.

  The output gear 6 is connected to the ring gear R so as to rotate integrally. Therefore, the ring gear R corresponds to the third rotating element of the present invention. Further, the output shaft 4 a of the second MG 4 is connected to the ring gear R via the connection switching device 21. The connection switching device 21 includes a first engagement disk 22, a second engagement disk 23, an operation disk 24, and an actuator 25 that drives the operation disk 24. The operation disk 24 is configured to be able to engage with the first engagement disk 22 and the second engagement disk 23. The engagement between the disks may be performed by a well-known mechanism that is generally used in clutches.For example, a dry or wet engagement mechanism, or each disk is provided with dog teeth, and the dog teeth are engaged with each other. A dog mechanism to be engaged may be applied.

  The first engagement disk 22 is connected to the ring gear R so as to rotate integrally with the ring gear R. The second engagement disk 23 is provided so as to rotate integrally with the output shaft 2 a of the engine 2. As shown in this figure, the output shaft 2 a of the engine 2 is provided with an extension shaft 2 b that passes through the centers of the first MG 3, the planetary gear mechanism 20, and the second MG 4 and extends to the connection switching device 21. The extension shaft 2b is provided so as to rotate integrally with the output shaft 2a. The second engagement disk 23 is provided so as to rotate integrally with the extension shaft 2b. The operation disk 24 is provided so as to rotate integrally with the output shaft 4a of the second MG 4. Further, the operation disk 24 is movable in the direction of the axis CL between a first engagement position that engages with the first engagement disk 22 and a second engagement position that engages with the second engagement disk 23. Are provided on the output shaft 4a. That is, the operation disk 24 is provided on the output shaft 4a so as to be movable in the direction of the axis CL and to rotate integrally with the output shaft 4a. Thus, in order to make the operation disk 24 movable in the direction of the axis CL, the output shaft 4a and the operation disk 24 are connected via a spline mechanism (not shown). The actuator 25 drives the operation disk 24 between the first engagement position and the second engagement position.

  The operation of the actuator 25 is controlled by a motor generator control unit (MGCU) 30. The MGCU 30 is configured as a computer including a microprocessor and peripheral devices such as RAM and ROM necessary for its operation. For example, the MGCU 30 includes a driving force required for a vehicle and a battery (not shown) connected to the first MG 3 and the second MG 4. Based on the state of charge or the like, the operation is switched so that the first MG 3 and the second MG 4 function as an electric motor or a generator. The MGCU 30 controls the rotational speeds of the MGs 3 and 4 in accordance with the traveling state of the vehicle, etc., but these control methods may be the same as well-known control methods and will not be described in detail. The MGCU 30 is connected to an accelerator opening sensor 31 that outputs a signal corresponding to the opening of the accelerator pedal.

  The operation of the engine 2 is controlled by an engine control unit (ECU) 40. The ECU 40 is configured as a well-known computer unit including a microprocessor and peripheral devices such as RAM and ROM necessary for its operation, and determines the operating state of the engine 2 based on output signals of various sensors provided in the engine 2. It is a well-known thing to control. For example, the ECU 40 executes fuel cut control for stopping the fuel supply to the engine 2 when the vehicle speed is equal to or higher than a predetermined determination speed and the accelerator opening is 0%, that is, the accelerator pedal is not depressed. To do. That is, the engine 2 is an application target of fuel cut control. The ECU 40 is connected to a crank angle sensor 41 that outputs a signal corresponding to the rotational speed (number of rotations) of the crankshaft of the engine 2 and a vehicle speed sensor 42 that outputs a signal corresponding to the speed of the vehicle. In addition to this, various sensors are connected to the ECU 40, but their illustration is omitted. As shown in FIG. 1, the MGCU 30 and the ECU 40 are connected so as to be able to share each other's information.

  FIG. 2 shows a switching control routine that the MGCU 30 executes to control the operation of the actuator 25. This switching control routine is repeatedly executed at a predetermined cycle while the vehicle is traveling. By executing this switching control routine, the MGCU 30 functions as the control means of the present invention. In the control routine of FIG. 2, the MGCU 30 first acquires the traveling state of the vehicle and the operating state of the engine 2 in step S11. As the running state of the vehicle, for example, the speed of the vehicle is acquired. As the operating state of the engine 2, for example, the rotational speed of the engine 2 and the accelerator opening are acquired. In the next step S12, the MGCU 30 determines whether or not the fuel cut control is being executed for the engine 2. Whether or not the fuel cut control is being executed may be determined based on the vehicle speed and the accelerator opening. When it is determined that the fuel cut control is not executed, the process proceeds to step S13, and the MGCU 30 controls the actuator 25 so that the operation disk 24 moves to the first engagement position. As a result, the second MG 4 and the ring gear R of the planetary gear mechanism 20 are directly connected. If the operation disk 24 has already been moved to the first engagement position, that state is maintained. In subsequent step S14, the MGCU 30 switches the control for the second MG 4 to the normal control for controlling the rotation direction and the rotation speed of the second MG 4 in accordance with the traveling state of the vehicle. By controlling the second MG 4 in this way, the power output to the drive wheels 12 by the second MG 4 can be controlled. If the control for the second MG 4 has already been normal control, that state is maintained. Thereafter, the current control routine is terminated.

  On the other hand, if it is determined that the fuel cut control is being executed, the process proceeds to step S15, and the MGCU 30 controls the actuator 25 so that the operation disk 24 moves to the second engagement position. Thereby, the output shaft 2a of the engine 2 and the second MG 4 are directly connected. If the operation disk 24 has already been moved to the second engagement position, that state is maintained. In subsequent step S16, the MGCU 30 switches the control for the second MG 4 to the motoring control. In this motoring control, the engine 2 is rotationally driven by the second MG 4 at a predetermined rotational speed (for example, 500 rpm). At this time, the operation of the second MG 4 is controlled so that the rotational speed fluctuation of the engine 2 caused by the pumping loss or the like is offset. That is, in the motoring control, the second MG 4 is controlled so that the engine 2 is rotationally driven at a predetermined rotational speed, and the rotational speed fluctuation generated at that time is offset. If the control for the second MG 4 is already motoring control, that state is maintained. Thereafter, the current control routine is terminated.

  In the drive device 1A of the first embodiment, the output shaft 2a of the engine 2 and the output shaft 4a of the second MG 4 can be directly connected by moving the operation disk 24 to the second engagement position. Therefore, the control accuracy of the rotational speed control when the engine 2 is rotationally driven by the second MG 4 can be improved. As a result, the engine 2 can be stably driven to rotate at a low speed by the second MG 4. Further, since the second MG 4 can cancel out the rotational speed fluctuation generated in the engine 2 at this time, the vibration of the vehicle can be suppressed. Furthermore, since the energy consumed by the second MG 4 can be reduced by rotating the engine 2 at a low rotational speed in this way, the energy efficiency of the vehicle can be improved.

  Further, the output shaft 2 a of the engine 2 is connected to the carrier C of the planetary gear mechanism 20 via the damper 13. Therefore, when the engine 2 is operated and the power of the engine 2 is transmitted to the planetary gear mechanism 20, the torque fluctuation of the engine 2 can be sucked by the damper 13. According to this drive device 1A, the connection switching device 21 switches the connection destination of the output shaft 4a of the second MG 4 so that the output shaft 2a of the engine 2 and the output shaft 4a of the second MG 4 can be directly connected. Therefore, it is not necessary to provide another drive source for driving the output shaft 2a of the engine 2. Therefore, the apparatus can be reduced in size.

(Second form)
FIG. 3 shows an outline of a driving apparatus 1B according to the second embodiment of the present invention. In FIG. 3, the same parts as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. In this embodiment, as shown in FIG. 3, the connection switching device 21, the second MG 4, the planetary gear mechanism 20, the first MG 3, and the damper 13 are arranged in this order along the axis CL direction from the side closer to the engine 2. That is, the second MG 4 is disposed on the engine 2 side than the first MG 3, and the connection switching device 21 is disposed between the engine 2 and the second MG 4. Since the second MG 4 is thus arranged near the engine 2, the carrier C of the planetary gear mechanism 20 is connected to the output shaft 2 a of the engine 2 via the extension shaft 2 b and the damper 13. A second engagement disk 23 of the connection switching device 21 is provided on the output shaft 2 a of the engine 2.

  According to the drive device 1B according to the second embodiment, since the second MG 4 is disposed near the engine 2, the power transmission path when the output shaft 4a of the second MG 4 and the output shaft 2a of the engine 2 are directly connected is shortened. it can. Therefore, for example, the torsional rigidity in the power transmission path can be improved, and the control accuracy of the rotational speed control of the engine 2 by the second MG 4 can be further improved. Therefore, the rotation speed when the engine 2 is rotationally driven by the second MG 4 can be further reduced. Thereby, the energy efficiency of the vehicle can be further improved.

  This invention is not limited to each form mentioned above, It can implement with a various form. For example, the operation disk may be moved to the second engagement position at a time other than when the fuel cut control is executed. For example, the operation disk may be moved to the second engagement position when the engine is started. In this case, since the engine can be started with the second MG having a higher output than the first MG, the engine can be started quickly. The engine and each MG may not be arranged coaxially. For example, the first MG and the second MG may be arranged in an offset state with respect to the rotation axis. Further, the planetary gear mechanism provided in the power distribution mechanism is not limited to one, and may include a plurality of planetary gear mechanisms. The differential mechanism provided in the power distribution mechanism is not limited to the planetary gear mechanism, and may be a planetary roller mechanism.

1A, 1B Driving device 2 Internal combustion engine 2a Output shaft 3 First motor generator (first rotating electrical machine)
3a Output shaft 4 Second motor generator (second rotating electrical machine)
4a Output shaft 6 Output gear (output member)
12 Drive Wheel 13 Damper 20 Planetary Gear Mechanism (Differential Mechanism)
21 Connection switching device (connection switching means)
30 Motor generator control unit (control means)
S Sun gear (second rotating element)
R ring gear (third rotating element)
C carrier (first rotating element)

Claims (3)

An internal combustion engine, a first rotating electrical machine, an output member for outputting power to drive wheels of the vehicle, and a differential mechanism having three rotational elements that can be differentially differentiated from each other, the output of the internal combustion engine The shaft is connected to the first rotating element of the differential mechanism via a damper, the output shaft of the first rotating electrical machine is connected to the second rotating element of the differential mechanism, and the output member is connected to the differential mechanism. In the hybrid vehicle drive device connected to the third rotating element,
Connection between the second rotating electrical machine and the output shaft of the second rotating electrical machine so that the output shaft of the second rotating electrical machine is selectively connected to either the output shaft of the internal combustion engine or the third rotating element. A connection switching means for switching the destination,
The connection switching means connects the output shaft of the second rotating electrical machine and the output shaft of the internal combustion engine so that the output shaft of the second rotating electrical machine and the output shaft of the internal combustion engine are directly connected. A hybrid vehicle drive device. The second rotating electrical machine has a larger output than the first rotating electrical machine,
The first rotating electrical machine and the second rotating electrical machine are disposed coaxially with an output shaft of the internal combustion engine, and the second rotating electrical machine is disposed closer to the internal combustion engine than the first rotating electrical machine. 2. A drive device for a hybrid vehicle according to 1. The internal combustion engine is an application target of fuel cut control in which the fuel supply is stopped when the speed of the vehicle is equal to or higher than a predetermined determination speed and the accelerator pedal is not depressed,
When the fuel cut control is being performed on the internal combustion engine, the operation of the connection switching unit is controlled so that the output shaft of the second rotating electrical machine is connected to the output shaft of the internal combustion engine, and Control means for controlling the operation of the second rotating electrical machine so that the output shaft of the internal combustion engine is rotationally driven at a predetermined rotational speed, and fluctuations in the rotational speed of the output shaft of the internal combustion engine that occur during the rotational drive are offset. The drive device for a hybrid vehicle according to claim 1, further comprising:

Images