JP2009190575A - Hybrid vehicle drive system - Google Patents

Abstract

A drive device for a hybrid vehicle is provided that can prevent reversal of torque when the operation mode is switched.
A drive device 2 includes a differential mechanism 7 in which two sets of planetary gear mechanisms 21 and 22 are combined. The differential mechanism 7 has five rotating elements of a sun gear S1, a ring gear R2, a carrier Cr, a ring gear R1, and a sun gear S2 that can rotate differentially with each other. The internal combustion engine 3 is connected to the sun gear S1, the output shaft 6 is connected to the sun gear S2, the first motor / generator 4 is connected to the ring gear R1 or the ring gear R2, and the second motor / generator 5 is connected to the carrier Cr or the sun gear S2. The mode switching mechanism 8 switches the operation mode by changing the connection relation of the motor / generators 4 and 5 to the differential mechanism 7.
[Selection] Figure 1

Description

  The present invention relates to a drive device for a hybrid vehicle that can be switched to a plurality of operation modes.

  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.

  As a drive device applied to such a hybrid vehicle, a power transmission path to a drive wheel of the vehicle is appropriately switched so that a driving mode suitable for a driving state can be selected from a plurality of driving modes. A so-called multi-mode type drive mechanism in which a reduction in power transmission efficiency is suppressed by reducing a load on an electric machine is well known. For example, such a multi-mode type driving device includes a differential mechanism configured as a Ravigneaux type planetary gear mechanism, an internal combustion engine serving as a ring gear of the differential mechanism, and a first motor / generator serving as a first gear. A sun gear is known in which an output shaft is selectively connected to a second sun gear or a carrier via a coupling mechanism, and the torque of the second motor / generator is input to the output shaft ( Patent Document 1). This drive device realizes a plurality of operation modes by operating the coupling mechanism to change the connection of the output shaft.

JP-A-2005-155891

  The drive device of Patent Document 1 is arranged in the order of the first sun gear, the carrier, the ring gear, and the second sun gear when the rotating elements of the differential device are arranged in a collinear diagram. That is, since the first sun gear and the second sun gear are arranged in a manner sandwiching the ring gear as an input element to which the internal combustion engine is connected, the torque of the first motor generator is reversed when the operation mode is switched. When such torque reversal occurs, there is a risk of drivability deterioration such as gear rattling noise.

  Therefore, an object of the present invention is to provide a hybrid vehicle drive device that can prevent reversal of torque when the operation mode is switched.

  The drive device for a hybrid vehicle of the present invention has five rotating elements that can rotate differentially with each other, and when the five rotating elements are arranged on a collinear diagram, the first rotating element, the second rotating element, A differential mechanism configured to be arranged in the order of a third rotating element, a fourth rotating element, and a fifth rotating element, an internal combustion engine connected to the first rotating element, and connected to the fifth rotating element An output member; a first rotating electrical machine selectively connected to the second rotating element or the fourth rotating element; a second rotating electrical machine connected to the third rotating element or the fifth rotating element; The above-described problem is solved by providing switching means for switching the operation mode by changing the connection relationship between the first rotating electric machine and the second rotating electric machine with respect to the differential mechanism (Claim 1).

  According to this drive device, the five rotating elements of the differential mechanism are arranged in the order of the first rotating element, the second rotating element, the third rotating element, the fourth rotating element, and the fifth rotating element on the collinear diagram, An internal combustion engine is connected to the first rotating element located at one end thereof. Therefore, since the first rotating element is not sandwiched between the two rotating elements, it is possible to prevent the torque from being reversed when the operation mode is switched by the switching unit.

  In one aspect of the present invention, the first rotating electrical machine and the second rotating electrical machine may be arranged next to the differential mechanism in a state of being adjacent to each other in the axial direction (Claim 2). In order to obtain the required output torque, the radial dimensions of the two rotating electric machines may have to be larger than the dimensions of the differential mechanism. According to this aspect, even in such a case, since the two rotating electrical machines are disposed adjacent to each other, the large diameter portion is only biased to one side. Therefore, it is possible to appropriately mount the FR rotating electric machine in a state in which the two rotating electric machines are directed to the front side of the FR vehicle in which the mounting space of the driving device is narrowed toward the rear of the vehicle.

  The differential mechanism can be configured using various mechanisms. For example, the differential mechanism includes two sets of planetary gear mechanisms including three rotating elements of a sun gear, a ring gear, and a carrier. The five rotating elements may be configured by being connected to each other so as to rotate integrally (claim 3). In this case, the two gears of the planetary gear mechanism are connected to each other so that the sun gear and the ring gear of one planetary gear mechanism, the sun gear and the ring gear of the other planetary gear mechanism, and the mutually connected The carrier is configured as five rotating elements. These planetary gear mechanisms may be single pinion type planetary gear mechanisms in which one pinion is interposed between the sun gear and the ring gear, or double pinion types in which two pinions that mesh with each other are interposed between the sun gear and the ring gear. The planetary gear mechanism may be used.

  In this aspect, the differential mechanism includes a sun gear of one planetary gear mechanism as the first rotating element, a sun gear of the other planetary gear mechanism as the fifth rotating element, and a ring gear of one planetary gear mechanism. As the second rotating element, the ring gear of the other planetary gear mechanism may be configured as the fourth rotating element, and the mutually connected carriers may be configured as the third rotating element.

  Although there is no particular limitation on the configuration of the switching means, for example, the switching means includes a first clutch for intermittently transmitting power between the second rotating electrical machine and the fifth rotating element, and the first rotating electrical machine. A second clutch that interrupts power transmission between the second rotating electrical machine and the fourth rotating element, a third clutch that interrupts power transmission between the second rotating electrical machine and the third rotating element, and the first rotating electrical machine And a fourth clutch for intermittently transmitting power between the second rotating element and the second rotating electrical machine and the fifth rotating element are connected via the first clutch and the first rotation. A first operation mode in which the electric machine and the fourth rotating element are connected via the second clutch; the first rotating electric machine and the fourth rotating element are connected via the second clutch; and A two-rotating electric machine and the third rotating element connect the third clutch. The second rotating electrical machine and the third rotating element are connected via the third clutch, and the first rotating electrical machine and the second rotating element are connected to the fourth operating mode. You may switch an operation mode between the 3rd operation modes connected via the clutch (Claim 5). Thereby, at least three operation modes can be selectively implemented by the switching means changing the intermittent state of each clutch. These clutches may be realized by various clutches such as a meshing clutch and a friction clutch.

  As described above, according to the present invention, the five rotating elements of the differential mechanism are arranged on the nomographic chart as the first rotating element, the second rotating element, the third rotating element, the fourth rotating element, and the fifth rotating element. Since the internal combustion engine is not connected to the first rotating element located at one end thereof and the first rotating element is sandwiched between the two rotating elements, the torque is reversed when the operation mode is switched. Can be prevented.

  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 motor, a differential mechanism 7 having five rotating elements to which these elements are connected, and connection of the first motor generator 4 and the second motor generator 5 to the differential mechanism 7 And a mode switching mechanism 8 as switching means for changing the relationship.

  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 has a stator 4a and a rotor 4b that are coaxial with each other, and the stator 4a is fixed to the casing 12 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.

  The differential mechanism 7 is configured by combining two sets of single pinion type planetary gear mechanisms 21 and 22. The first planetary gear mechanism 21 rotates a sun gear S1 that is an external gear, a ring gear R1 that is an internal gear disposed coaxially with the sun gear S1, and a pinion 25 that meshes with these gears S1 and R1. And a carrier Cr that is held to revolve freely. On the other hand, the second planetary gear mechanism 22 meshes with the sun gear S2 that is an external gear, the ring gear R2 that is an internal gear disposed coaxially with the sun gear S2, and the gears S2 and R2. It has the carrier Cr which supports the pinion 26 coaxially integrated with the pinion 25 of the 1 planetary gear mechanism 21 so that rotation and revolution are possible. That is, the carrier Cr that holds the two integrated pinions 25 and 26 is shared between the first planetary gear mechanism 21 and the second planetary gear mechanism 22. In other words, the differential mechanism 7 is connected to each other so that the respective carriers Cr of the first planetary gear mechanism 21 and the second planetary gear mechanism 22 rotate integrally. One pinion 25 held by the carrier Cr has fewer teeth than the other pinion 26. That is, the pinion 25 has a smaller reference circle diameter than the pinion 26. The planetary gear mechanism including the pinions 25 and 26 having different diameters integrated as described above may be called a stepped pinion type planetary gear mechanism.

  FIG. 2 shows an alignment chart of the differential mechanism 7. As is well known, the collinear diagram is a well-known that the rotational speed of each rotating element can be represented by 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. In the following description, “ENG” in the figure represents the internal combustion engine 3, “MG1” represents the first motor / generator 4, “MG2” represents the second motor / generator 5, and “OUT” represents the output shaft 6. means. As shown in FIG. 2, when the five rotating elements of the differential mechanism 7 are arranged on the collinear chart, these elements are arranged in the order of the sun gear S1, the ring gear R2, the carrier Cr, the ring gear R1, and the sun gear S2. It is done. 1 and 2, the internal combustion engine 3 is connected to the sun gear S1, and the output shaft 6 is connected to the sun gear S2. The first motor / generator 4 is selectively connected to the ring gear R1 or the ring gear R2 via the mode switching mechanism 8, and the second motor / generator 5 is connected to the carrier Cr or the sun gear S2 via the mode switching mechanism 8. Connected selectively. Therefore, the sun gear S1 is related to the first rotating element according to the present invention, the ring gear R2 is related to the second rotating element according to the present invention, the carrier Cr is related to the third rotating element according to the present invention, and the ring gear R1 is related to the present invention. The sun gear S2 corresponds to the fourth rotating element and corresponds to the fifth rotating element according to the present invention.

  The mode switching mechanism 8 has four clutches C1 to C4. Each of the clutches C1 to C4 is configured as a friction clutch. Each of the clutches C1 to C4 is provided with a hydraulic actuator (not shown) so that it can be operated independently. The mode switching mechanism 8 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 to C4 are arbitrary. For example, they can be configured as a meshing clutch.

  The first clutch C1 interrupts power transmission between the second motor / generator 5 and the sun gear S2. That is, the first clutch C1 operates between an engaged state in which the second motor / generator 5 and the sun gear S2 are connected and a released state in which the connection is released. The second clutch C2 interrupts power transmission between the first motor / generator 4 and the ring gear R1. That is, the second clutch C2 operates between an engaged state in which the first motor / generator 4 and the ring gear R1 are connected and a released state in which the connection is released. The third clutch C3 interrupts power transmission between the second motor / generator 5 and the carrier Cr. That is, the third clutch C3 operates between an engaged state in which the second motor / generator 5 and the carrier Cr are connected and a released state in which the connection is released. The fourth clutch C4 interrupts power transmission between the first motor / generator 4 and the ring gear R2. That is, the fourth clutch C4 operates between an engaged state in which the first motor / generator 4 and the ring gear R2 are connected and a released state in which the connection is released.

  Next, operation mode switching performed by the mode switching mechanism 8 will be described with reference to FIGS. The driving device 2 selectively executes a low geared low mode, a high geared high mode, and an intermediate mid mode between them by setting a combination of operating states of the clutches C1 to C4 of the mode switching mechanism 8 to a predetermined pattern. To do. The Low mode corresponds to the first operation mode according to the present invention, the High mode corresponds to the third operation mode according to the present invention, and the Mid mode corresponds to the second operation mode according to the present invention.

  FIG. 3 shows an engagement table in which each operation mode is associated with the operation state of each of the clutches C1 to C4. In this figure, ◯ indicates an engaged state, − indicates a released state, and Δ indicates a transient state when changing from an engaged state to a released state or from a released state to an engaged state. As shown in the figure, in the low mode, the first clutch C1 and the second clutch C2 are each held in an engaged state, and the remaining clutches C3 and C4 are each held in a released state. In the Mid mode, the second clutch C2 and the third clutch C3 are each held in an engaged state, and the remaining clutches C1 and C4 are each held in a released state. In the high mode, the third clutch C3 and the fourth clutch C4 are each held in an engaged state, and the remaining clutches C1 and C2 are each held in a released state. When switching between these modes, synchronization control between elements connected by the clutch is performed after the mode switching (Low-Mid synchronization mode, Mid-High synchronization mode).

  4 to 8 show collinear diagrams in each mode. The solid arrows in these figures indicate the torque acting on the rotating element. Hereinafter, the contents of each mode and the switching of those modes will be described with reference to these drawings in order.

  As shown in FIG. 4, in the low mode, the first clutch C1 and the second clutch C2 are held in the engaged state, and the remaining clutches C3 and C4 are held in the released state. The torque of the first motor / generator 4 acts on the ring gear R1 and the torque of the second motor / generator 5 acts on the output shaft 6 so as to oppose the torque acting on the sun gears S1, S2.

  As shown in FIG. 5, when switching from the Low mode to the Mid mode, the first clutch C1 is changed from the engaged state to the released state while the second clutch C2 is held in the engaged state. This frees the second motor / generator 5. By controlling the torque of the first motor / generator 4 with the second motor / generator 5 free and maintaining the sign of the torque acting on the ring gear R1, the second clutch C3 is scheduled to be connected. The rotational speeds of the motor / generator 5 and the carrier Cr are synchronized. After the synchronization is completed, the third clutch C3 is changed from the released state to the engaged state. Thereby, the connection target of the second motor / generator 5 is shifted from the sun gear S2 to the carrier Cr, and the operation mode is switched to the Mid mode shown in FIG.

  As shown in FIG. 6, in the Mid mode, the second clutch C2 and the third clutch C3 are held in the engaged state, and the remaining clutches C1 and C4 are held in the released state. The torque of the first motor / generator 4 acts on the ring gear R1 and the torque of the second motor / generator 5 acts on the carrier Cr in a manner that counteracts the torque acting on the sun gears S1, S2.

  As shown in FIG. 7, when switching from the Mid mode to the High mode, the second clutch C2 is changed from the engaged state to the released state while the third clutch C3 is held in the engaged state. This frees the first motor / generator 4. By controlling the torque of the first motor / generator 4 with the first motor / generator 4 free and maintaining the sign of the torque acting on the ring gear R1, the first clutch scheduled to be connected by the fourth clutch C4. The rotational speeds of the motor / generator 4 and the ring gear R2 are synchronized. After the synchronization is completed, the fourth clutch C4 is changed from the released state to the engaged state. As a result, the connection object of the first motor / generator 4 is shifted from the ring gear R1 to the ring gear R2, and the operation mode is switched to the High mode shown in FIG.

  As shown in FIG. 8, in the high mode, the third clutch C3 and the fourth clutch C4 are held in the engaged state, and the remaining clutches C1 and C2 are held in the released state. The torque of the first motor / generator 4 acts on the ring gear R2 and the torque of the second motor / generator 5 acts on the carrier Cr in a manner that counteracts the torque acting on the sun gears S1 and S2.

  Thus, since each operation mode is switched, torque inversion does not occur when the operation mode is switched, as is apparent with reference to FIGS. On the contrary, when switching the operation mode from the high mode to the mid mode or from the mid mode to the low mode, the operation procedure of the clutch is only opposite to the above. Inversion of does not occur.

  FIG. 9 is a diagram showing the transmission efficiency in each operation mode with respect to the total gear ratio. In this figure, the transmission efficiency of the comparative example in which the operation mode is fixed for comparison with the present embodiment is indicated by a two-dot chain line. As shown in the figure, the transmission efficiency of each operation mode changes with respect to the total gear ratio, and the tendency of the change differs for each operation mode. For example, when divided into three regions A to C, the transmission efficiency in the low mode is the highest in region A, the transmission efficiency in the mid mode is highest in region B, and the transmission efficiency in the high mode is highest in region C. Therefore, by setting the boundary P1 and P2 of each region as the switching point of the operation mode, selecting the Low mode in the region A, the Mid mode in the region B, and the High mode in the region C, the transmission efficiency can be reduced widely. Can be suppressed. Furthermore, the overall transmission efficiency can be maintained higher than in the comparative example in which the operation mode is fixed.

  Next, the arrangement of the driving device 2 will be described. As shown in FIG. 1, in the case of an FR vehicle such as the vehicle 1, the mounting space for the drive device 2 is narrowed toward the rear of the vehicle. The drive device 2 is arranged next to the differential mechanism 7 in a state where the first motor / generator 4 and the second motor / generator 5 are adjacent to each other in the axial direction, and the motor / generators 4 and 5 are arranged in front of the vehicle (see FIG. (To the left of 1) Therefore, even when the outer diameters of the motor generators 4 and 5 are increased, the large diameter portion is only biased forward, so that the mounting space of the vehicle can be used effectively, and the drive device 2 is appropriately applied to the vehicle 1. Can be installed.

In general, the torque of the motor / generator can be expressed as D ² × L or D ³ × L, where D is the outer diameter of the rotor and stator, and L is the thickness of the rotor and stator in the axial direction. it can. Therefore, in order to increase the torque of the motor / generator, it is more advantageous to increase the outer diameter D than to increase the thickness L. Since the drive device 2 has a margin for increasing the outer diameter, it is easy to increase the torque of the motor / generator while suppressing an increase in dimension in the axial direction. Therefore, it is possible to improve the mountability of the vehicle.

  The present invention is not limited to the above form, and the above-described differential mechanism is only an example, and these can be changed to another form that is mechanically equivalent. Realizing the differential mechanism by combining a plurality of planetary gear mechanisms is merely an example. 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. FIG. 2 is a collinear diagram of the differential device shown in FIG. 1. The figure which showed the engagement table | surface with which each operation mode and the operation state of each clutch were matched. The alignment chart in Low mode. The collinear diagram in Low-Mid synchronous mode. The collinear diagram in the Mid mode. The collinear diagram in a Mid-High synchronous mode. The alignment chart in the High mode. The figure which showed the transmission efficiency of each operation mode regarding the total gear ratio.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Drive apparatus 3 Internal combustion engine 4 1st motor generator (1st rotary electric machine)
5 Second motor / generator (second rotating electrical machine)
6 Output shaft (output member)
7 Differential mechanism 8 Mode switching mechanism (switching means)
21, 22 Planetary gear mechanisms S1, S2 Sun gear R1, R2 Ring gear Cr Carrier C1 First clutch C2 Second clutch C3 Third clutch C4 Fourth clutch

Claims (5)

  Having five rotating elements capable of differentially rotating with respect to each other, and arranging the five rotating elements on a collinear diagram, a first rotating element, a second rotating element, a third rotating element, a fourth rotating element, A differential mechanism configured to be arranged in the order of the fifth rotating element; an internal combustion engine connected to the first rotating element; an output member connected to the fifth rotating element; and the second rotating element or A first rotating electrical machine selectively connected to the fourth rotating element; a second rotating electrical machine connected to the third rotating element or the fifth rotating element; the first rotating electrical machine for the differential mechanism; A hybrid vehicle drive device comprising: switching means for switching an operation mode by changing a connection relation of the second rotating electrical machine.   2. The drive device according to claim 1, wherein the first rotating electric machine and the second rotating electric machine are arranged next to the differential mechanism in a state of being adjacent to each other in the axial direction.   The differential mechanism is connected to each other so that the carriers of the two planetary gear mechanisms including the three rotating elements of the sun gear, the ring gear, and the carrier rotate together, whereby the five rotating elements are configured. The drive device according to claim 1 or 2, wherein   The differential mechanism includes a sun gear of one planetary gear mechanism as the first rotating element, a sun gear of the other planetary gear mechanism as the fifth rotating element, and a ring gear of one planetary gear mechanism as the second rotating element. 4. The driving device according to claim 3, wherein the ring gear of the other planetary gear mechanism is configured as the fourth rotating element, and the interconnected carriers are configured as the third rotating element.   The switching means interrupts power transmission between the first rotating electric machine and the fourth rotating element, and a first clutch that interrupts power transmission between the second rotating electric machine and the fifth rotating element. A second clutch, a third clutch that interrupts power transmission between the second rotating electrical machine and the third rotating element, and a power transmission between the first rotating electrical machine and the second rotating element are interrupted. A fourth clutch, wherein the second rotating electrical machine and the fifth rotating element are connected via the first clutch, and the first rotating electrical machine and the fourth rotating element are connected via the second clutch. The first operating mode connected to each other, the first rotating electrical machine and the fourth rotating element connected via the second clutch, and the second rotating electrical machine and the third rotating element connected to the third clutch. The second operation mode connected through the second rotation mode and the second rotation Between the third operating mode in which the machine and the third rotating element are connected via the third clutch, and the first rotating electrical machine and the second rotating element are connected via the fourth clutch. The drive apparatus as described in any one of Claims 1-4 which switches an operation mode.

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