JP2009190693A - Drive unit of hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive unit of a hybrid vehicle capable of freely setting a torque required by a rotary motor at the time of starting an operation of an internal combustion engine irrespective of a distribution ratio of a drive power distributing mechanism. <P>SOLUTION: This drive unit 2 has a starting differential mechanism 8 for use in starting an operation of an internal combustion engine 3 and a drive power distributing mechanism 7 for distributing a drive power of the internal combustion engine 3 and a first motor generator 4 is connected to these mechanisms through clutches C1, C2. The starting differential mechanism 8 is connected to the internal combustion engine 3 under a state in which a carrier Cr2 has a one-way clutch 22 therein, a sun-gear S2 is connected to the first motor generator 4 under a state in which a second clutch C2 is present thereat and at the same time a gear ratio between the rotary elements is set in such a way that the rotary speed of the first motor generator 4 is decelerated and transmitted to the internal combustion engine 3 when the internal combustion engine 3 is started to operate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hybrid vehicle drive device capable of switching a mode between a start mode for starting an internal combustion engine and a normal mode performed during normal travel.

  As is well known, a hybrid vehicle is a vehicle that includes an internal combustion engine as a driving force source for traveling, and a rotating electrical machine such as an electric motor or a motor / generator as another driving force source for traveling. The hybrid vehicle operates the internal combustion engine in as efficient a manner as possible while compensating for excess or deficiency of the driving force or engine braking force with another driving force source and regenerating energy when the vehicle decelerates or the like. Thus, it is configured to prevent the deterioration of the emission of the internal combustion engine and improve the fuel efficiency.

  In a drive device applied to such a hybrid vehicle, a rotating electrical machine mounted as a travel drive source is used to start the internal combustion engine, and the power of the rotating electrical machine is transmitted to the internal combustion engine via a power distribution mechanism. It is common to crank. For a hybrid vehicle drive device in which the internal combustion engine and the drive motor for driving are directly connected, the rotation of the starting motor different from the drive motor is reduced by the planetary gear mechanism and transmitted to the internal combustion engine. Some have an electric motor unit for starting (cranking) an internal combustion engine (Patent Document 1).

JP-A-2005-299406

  By the way, in the hybrid vehicle drive device that distributes the power of the internal combustion engine to the output member and the rotating electrical machine by the power distribution mechanism, the distribution ratio of the power distribution mechanism is set in view of the efficiency during normal travel. Yes. Therefore, when a rotating electrical machine is used for starting an internal combustion engine, the torque required for cranking is determined by the distribution ratio of the power distribution mechanism, and the torque required for cranking can be set freely. Can not. For these reasons, excessive torque may be generated in the rotating electrical machine when the internal combustion engine is started.

  Accordingly, an object of the present invention is to provide a hybrid vehicle drive device that can freely set the torque required by the rotating electrical machine when starting the internal combustion engine regardless of the distribution ratio of the power distribution mechanism. .

  A drive device for a hybrid vehicle of the present invention includes an internal combustion engine, a first rotating electrical machine, an output member for outputting power to driving wheels of the vehicle, and the power of the internal combustion engine for the first rotating electrical machine and the output member. A power distribution mechanism that can distribute power to the output member, a second rotating electrical machine that can output power to the output member side, and a first clutch that can interrupt power transmission between the first rotating electrical machine and the power distribution mechanism. A starting differential mechanism for cranking the internal combustion engine by transmitting a power of the first rotary electric machine to the internal combustion engine; A second clutch capable of intermittently transmitting and receiving power to and from the starting differential mechanism; and permitting power transmission between the power distributing mechanism and the first rotating electrical machine; and the first rotating electrical machine and the starting difference. Power transmission to the dynamic mechanism is prohibited A normal mode in which the first clutch and the second clutch are operated, power transmission between the power distribution mechanism and the first rotating electrical machine is prohibited, and the first rotating electrical machine and the starting differential mechanism are prohibited. Mode switching means for switching a mode between a start mode in which the first clutch and the second clutch are operated so as to allow power transmission between the start differential mechanism and the start differential mechanism. Any one of the rotating elements is connected to the internal combustion engine with a one-way clutch interposed to prevent power transmission from the internal combustion engine side, and the other rotating element of any of the plurality of rotating elements Is coupled to the first rotating electrical machine with the second clutch interposed, and the rotational speed of the first rotating electrical machine is reduced when the engine is switched to the start mode, so that the internal combustion engine is By the speed ratio between the plurality of rotational elements is set to be transferred to, to solve the problems described above (Claim 1).

  According to this drive device, when the mode switching means switches to the start mode, power transmission between the power distribution mechanism and the first rotating electrical machine is prohibited, and the first rotating electrical machine and the starting differential mechanism are prohibited. Power transmission to and from is allowed. For this reason, the torque required when cranking the internal combustion engine with the first rotating electrical machine does not depend on the distribution ratio of the power distribution mechanism. Therefore, by appropriately setting the speed ratio between the rotating elements of the starting differential mechanism, the torque required at the time of starting the internal combustion engine can be freely set regardless of the distribution ratio of the power distribution mechanism. Thereby, the torque which a 1st rotary electric machine requires at the time of starting can be reduced as much as possible. Further, after the internal combustion engine is started, the optimum operating state can be realized by switching from the start mode to the normal mode. In addition, since any one of the rotating elements of the starting differential mechanism is connected to the internal combustion engine with a one-way clutch that prevents transmission of power from the internal combustion engine side, the starting differential mechanism is in the normal mode. There will be no hindrance.

  There is no particular limitation on the configuration of the starting differential mechanism. For example, the starting differential mechanism includes three rotating elements as the plurality of rotating elements, and any two of the three rotating elements. The rotating element is connected to the internal combustion engine or the first rotating electrical machine, and the remaining one rotating element is fixed with another one-way clutch that allows rotation in only one direction with respect to a predetermined fixing element. It may be connected to the element (Claim 2). Due to the presence of the other one-way clutch, it becomes unnecessary to cancel the reaction force generated in the starting differential mechanism by the cranking of the internal combustion engine by the first rotating electrical machine by operating the second rotating electrical machine.

  In one aspect of the driving apparatus of the present invention, the driving device further includes a tamper that is interposed between the internal combustion engine and the power distribution mechanism and attenuates vibrations that may be generated between the internal combustion engine and the power distribution mechanism. The damper may be bypassed and connected to the internal combustion engine (claim 3). According to this aspect, it is possible to suppress the occurrence of vibration accompanying the torque fluctuation of the internal combustion engine by the damper provided between the internal combustion engine and the power distribution mechanism. Since the starting differential mechanism bypasses the damper and is connected to the internal combustion engine, vibration generated during cranking by the first rotating electrical machine is reduced as compared with a mode in which the damper is interposed therebetween. be able to.

  As described above, according to the present invention, when the mode switching means switches to the start mode, power transmission between the power distribution mechanism and the first rotating electrical machine is prohibited, and the first rotating electrical machine and Since power transmission with the starting differential mechanism is allowed, the torque required for cranking the internal combustion engine with the first rotating electrical machine does not depend on the distribution ratio of the power distribution mechanism. Therefore, by appropriately setting the speed ratio between the rotating elements of the starting differential mechanism, the torque required at the time of starting the internal combustion engine can be freely set regardless of the distribution ratio of the power distribution mechanism. Thereby, the torque which a 1st rotary electric machine requires at the time of starting can be reduced as much as possible.

  FIG. 1 shows an outline of a vehicle to which a drive device according to an embodiment of the present invention is applied. As shown in this figure, the vehicle 1 is configured as a so-called hybrid vehicle. The vehicle 1 is provided with a driving device 2 for traveling. The drive device 2 outputs power to the internal combustion engine 3, the first motor / generator 4 as the first rotating electrical machine, the second motor / generator 5 as the second rotating electrical machine, and the drive wheels 10 of the vehicle 1. An output shaft 6 as an output member of the engine, a power distribution mechanism 7 to which these elements are connected, and a starter for cranking the internal combustion engine 3 by transmitting the power of the first motor / generator 4 to the internal combustion engine 3 A differential mechanism 8 and a mode switching mechanism 9 as a mode switching means for changing the power transmission of the first motor / generator 5 to the power distribution mechanism 7 and the starting differential mechanism 8 are provided.

  The internal combustion engine 3 is configured as a spark ignition type multi-cylinder internal combustion engine. The first motor / generator 4 is configured to generate a function as an electric motor and a function as a generator. A battery (not shown) is electrically connected to the first motor / generator 4 via an inverter (not shown), and the output torque or regenerative torque of the first motor / generator 4 is appropriately set by controlling the inverter. It is supposed to be. The first motor / generator 4 includes a stator 4a and a rotor 4b that are coaxial with each other, and the stator 4a is fixed to a casing 12 that is a fixed element so as not to rotate. Similarly to the first motor / generator 4, the second motor / generator 5 has a stator 5a and a rotor 5b that are coaxial with each other, and the stator 5a is fixed to the casing 12 so as not to rotate. The output shaft 6 is connected to a differential device 13 that allows differential rotation of the left and right drive wheels 10. A rotor 5b of the second motor / generator 5 is mounted on the output shaft 6 so as to be integrally rotatable.

  The power distribution mechanism 7 is configured as a single pinion type planetary gear mechanism. The power distribution mechanism 7 rotates and revolves a sun gear S1 that is an external gear, a ring gear R1 that is an internal gear arranged coaxially with the sun gear S1, and a pinion 15 that meshes with these gears S1 and R1. And a carrier Cr1 that is freely held. The sun gear S <b> 1 is connected to the first motor / generator 4 via the mode switching mechanism 9. The ring gear R1 is connected to the output shaft 6 so as to be integrally rotatable. The carrier Cr1 is connected to the internal combustion engine 3 via a damper 16 that attenuates vibration generated between the internal combustion engine 3 and the power distribution mechanism 7.

  The starting differential mechanism 8 is configured as a single pinion type planetary gear mechanism. The starting differential mechanism 8 includes a sun gear S2 that is an external gear as a plurality of rotational elements that can rotate differentially with each other, a ring gear R2 that is an internal gear coaxially disposed with respect to the sun gear S2, And a carrier Cr2 that holds the pinion 17 meshing with the gears S2 and R2 so as to rotate and revolve. The sun gear S <b> 2 is connected to the first motor / generator 4 via the mode switching mechanism 9. The ring gear R2 is connected to the casing 12 via a one-way clutch 21. The one-way clutch 21 is mounted so as to allow only rotation in one direction of the ring gear R2 and prohibit rotation in the reverse direction. The carrier Cr2 is connected to the internal combustion engine 3 via the one-way clutch 22. The one-way clutch 22 is attached so as to prevent power transmission from the internal combustion engine 3 side. The carrier Cr2 is connected to the internal combustion engine 3 so as to bypass the damper 16.

  The mode switching mechanism 9 has two clutches C1 and C2. Each of the clutches C1 and C2 is configured as a friction clutch. Each of the clutches C1 and C2 is provided with a hydraulic actuator (not shown) so that it can be operated independently. The mode switching mechanism 9 is provided with a control device for controlling the supply of hydraulic pressure to each actuator, but the illustration is omitted. The types of the clutches C1 and C2 are arbitrary. For example, they can be configured as meshing clutches.

  The first clutch C <b> 1 interrupts power transmission between the first motor / generator 4 and the sun gear S <b> 1 of the power distribution mechanism 7. That is, the first clutch C1 operates between an engaged state in which the first motor / generator 4 and the sun gear S1 are connected and a released state in which the connection is released. The second clutch C <b> 2 interrupts power transmission between the first motor / generator 4 and the sun gear S <b> 2 of the starting differential mechanism 8. That is, the second clutch C2 operates between an engaged state in which the first motor / generator 4 and the sun gear S2 are connected and a released state in which the connection is released.

  Next, operation mode switching performed by the mode switching mechanism 9 will be described with reference to FIGS. The drive device 2 changes the operation state pattern of each of the clutches C1 and C2 of the mode switching mechanism 9 to change between a normal mode used during normal traveling and a start mode used when starting the internal combustion engine 3. Run selectively. FIG. 2 shows an engagement table in which each operation mode is associated with the operation state of each clutch C1, C2. In this figure, ◯ indicates the engaged state, and-indicates the released state. As shown in the drawing, in the normal mode, the first clutch C1 is held in the engaged state, and the second clutch C2 is held in the released state. On the other hand, in the start mode, the first clutch C1 is held in the released state and the second clutch C2 is held in the engaged state. Note that when switching between these modes, rotation synchronization control between elements connected by the clutch is performed after the mode switching, but the details are omitted.

  FIG. 3 shows an alignment chart in the start mode, and FIG. 4 shows an alignment chart in the normal mode. As is well known, the collinear chart can represent the rotational speed of each rotating element as a straight line when the rotating elements of a differential mechanism such as a planetary gear mechanism are arranged at intervals based on the gear ratio (speed ratio). is there. These drawings show the collinear charts of the power distribution mechanism 7 and the starting differential mechanism 8 superimposed on each other. In these drawings, “ENG” indicates the internal combustion engine 3, “MG1” indicates the first motor / generator 4, “MG2” indicates the second motor / generator 5, and “OUT” indicates the output shaft 6. Means each.

  As shown in FIG. 3, in the start mode, the first clutch C1 is held in the disengaged state and the second clutch C2 is held in the engaged state, so that the power of the first motor / generator 4 is supplied to the starting differential mechanism 8. Is transmitted to the internal combustion engine 3 via the engine and cranked. In that case, the ring gear R <b> 2 is stationary with respect to the casing 12 by the action of the one-way clutch 21. In the starting differential mechanism 8, the gear ratio between the rotating elements is set so that the rotational speed at the time of cranking of the internal combustion engine 3 is slower than the rotational speed of the first motor / generator 4. As a result, the torque of the first motor / generator 4 is amplified by the starting differential mechanism 8, so that the torque required when starting the internal combustion engine 3 can be reduced. As is apparent from FIG. 3, this figure shows a situation where the vehicle 1 starts the internal combustion engine 3 while traveling by the power of the second motor / generator 5. Since the first clutch C1 is in the disengaged state, the sun gear S1 of the power distribution mechanism 2 rotates at a speed corresponding to the rotational speeds of the internal combustion engine 3 and the output shaft 6.

  On the other hand, as shown in FIG. 4, in the normal mode, the first clutch C <b> 1 is held in the engaged state and the second clutch C <b> 2 is held in the disengaged state. The vehicle 1 travels while being distributed according to the distribution ratio. In the normal mode of FIG. 4, power transmission from the internal combustion engine 3 to the starting differential mechanism 8 is interrupted by the one-way clutch 22, so that it does not interfere with the normal mode such as rotating the starting differential mechanism 8. .

  According to the drive device 2 described above, the torque required when the internal combustion engine 3 is cranked by the first motor / generator 4 in the start mode does not depend on the distribution ratio of the power distribution mechanism 7. Therefore, by appropriately setting the gear ratio between the rotating elements of the starting differential mechanism 8, the torque required at the time of starting the internal combustion engine 3 can be freely set regardless of the distribution ratio of the power distribution mechanism 7. Become. Thereby, the torque which the 1st motor generator 4 requires in start mode can be reduced as much as possible.

  Further, as shown in FIG. 1, the driving device 2 includes a tamper 16 interposed between the internal combustion engine 3 and the power distribution mechanism 7, but the carrier Cr <b> 2 of the starting differential mechanism 8 bypasses the damper 16. The internal combustion engine 3 is connected. For this reason, the drive device 2 can reduce vibrations generated during cranking of the internal combustion engine 3 as compared with a mode in which the damper 16 is interposed between the carrier Cr2 and the internal combustion engine 3.

  This invention is not restrict | limited to the above form, In the range of the summary of this invention, it can implement with a various form. Each structure of the power distribution mechanism 7 and the starting differential mechanism 8 described above is merely an example, and it is possible to change these to other forms that are mechanically equivalent. 5 and 6 show modifications of the driving device 2, respectively. In these modified examples, the same reference numerals are assigned to configurations common to the above-described embodiments, and description thereof is omitted.

  FIG. 5 shows an example in which the starting differential mechanism is changed to a double pinion planetary gear mechanism. The starting differential mechanism 80 includes a sun gear S21 that is an external gear as a plurality of rotational elements that can be differentially rotated with each other, and a ring gear R21 that is an internal gear disposed coaxially with the sun gear S21. And a carrier Cr21 that holds the pinions 31 and 32 so as to rotate and revolve in a state where the first pinion 31 meshing with the gear S21 and the second pinion 32 meshing with the gear R21 are meshed with each other. The sun gear S <b> 21 is connected to the first motor / generator 4 via the mode switching mechanism 9. Ring gear R21 is connected to internal combustion engine 3 via one-way clutch 22. The ring gear R21 is connected to the internal combustion engine 3 so as to bypass the damper 16. The carrier Cr21 is connected to the casing 12 via the one-way clutch 21. Even when the mechanism is changed as shown in FIG. 5, the same effect as that of the embodiment shown in FIG. 1 can be exhibited.

  FIG. 6 shows an example in which the power distribution mechanism is changed to a planetary gear mechanism on the double pinion side. The power distribution mechanism 70 meshes with a sun gear S11 that is an external gear, a ring gear R11 that is an internal gear disposed coaxially with the sun gear S11, a first pinion 41 that meshes with the gear S11, and a gear R11. A carrier Cr11 that holds the pinions 41 and 42 so as to rotate and revolve in a state where the second pinions 42 are engaged with each other. The sun gear S <b> 11 is connected to the first motor / generator 4 via the mode switching mechanism 9. The ring gear R11 is connected to the internal combustion engine 3 via a damper 16. The carrier Cr11 is coupled to an output gear 60 as an output member so as to be integrally rotatable. A power transmission path including a gear train (not shown) or the like may be provided between the output gear 60 and the differential device 13. In that case, the second motor / generator 5 may be provided between the output gear 60 and the differential device 13. Even when the mechanism is changed as shown in FIG. 6, the same effect as that of the embodiment shown in FIG. 1 can be exhibited. Moreover, since the form of FIG. 6 is an arrangement that is advantageous for shortening the dimension in the axial direction, there is an advantage that mounting feasibility for the FF vehicle is high. In FIG. 6, the starting differential mechanism 8 can be replaced with the starting differential mechanism 80 shown in FIG.

  1, 5, and 6 are configured as planetary gear mechanisms, the realization of the starting differential mechanism and the power distribution mechanism according to the present invention as planetary gear mechanisms is merely an example. Absent. For example, all or part of the planetary gear mechanism of each embodiment described above can be replaced with a planetary roller mechanism having a friction wheel (roller) that is not a gear as a rotating element.

The figure which showed the outline of the vehicle to which the drive device which concerns on one form of this invention was applied. The figure which showed the engagement table | surface with which each operation mode and the operation state of each clutch were matched. The figure which showed the alignment chart in starting mode. The figure which showed the alignment chart in normal mode. The figure which showed the example which changed the starting differential mechanism into the double pinion type planetary gear mechanism. The figure which showed the example which changed the power distribution mechanism into the planetary gear mechanism of the double pinion side.

Explanation of symbols

2 Drive unit 3 Internal combustion engine 4 First motor / generator (first rotating electrical machine)
5 Second motor / generator (second rotating electrical machine)
6 Output shaft (output member)
7 Power distribution mechanism 8 Differential mechanism for starting 9 Mode switching mechanism (mode switching means)
12 Casing (fixing element)
16 Damper 21 One-way clutch (other one-way clutch)
22 One-way clutch C1 First clutch C2 Second clutch

Claims (3)

An internal combustion engine, a first rotating electrical machine, an output member for outputting power to driving wheels of a vehicle, a power distribution mechanism capable of distributing the power of the internal combustion engine to the first rotating electrical machine and the output member, and the output A second rotating electrical machine that can output power to the member side; a first clutch that can intermittently transmit power between the first rotating electrical machine and the power distribution mechanism; and a plurality of rotating elements that are capable of differentially rotating with each other. And a starting differential mechanism for transmitting the power of the first rotating electrical machine to the internal combustion engine to crank the internal combustion engine, and a power between the first rotating electrical machine and the starting differential mechanism. Allowing power transmission between the second clutch capable of intermittent transmission and transmission, the power distribution mechanism and the first rotating electrical machine, and prohibiting power transmission between the first rotating electrical machine and the starting differential mechanism The first clutch and the second clutch A normal mode in which the power is operated, power transmission between the power distribution mechanism and the first rotating electrical machine is prohibited, and power transmission between the first rotating electrical machine and the starting differential mechanism is allowed. Mode switching means for switching the mode between a start mode for operating the first clutch and the second clutch as described above,
The starting differential mechanism is connected to the internal combustion engine in a state in which any one of the plurality of rotating elements interposes a one-way clutch that prevents power transmission from the internal combustion engine side, and Any other rotating element of the rotating element is connected to the first rotating electric machine with the second clutch interposed, and the rotation speed of the first rotating electric machine is changed to the start mode. A drive device for a hybrid vehicle, wherein a speed ratio between the plurality of rotating elements is set so as to be decelerated and transmitted to the internal combustion engine.   The starting differential mechanism has three rotating elements as the plurality of rotating elements, and any two of the three rotating elements are connected to the internal combustion engine or the first rotating electric machine, and the rest 2. The drive device for a hybrid vehicle according to claim 1, wherein one of the rotating elements is connected to the fixed element in a state of interposing another one-way clutch that allows rotation in only one direction relative to the predetermined fixed element. . A tamper that is interposed between the internal combustion engine and the power distribution mechanism and damps vibrations that may occur between the engine and the power distribution mechanism;
The hybrid vehicle drive device according to claim 1, wherein the starting differential mechanism is connected to the internal combustion engine so as to bypass the damper.

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