JP2009190694A - Drive unit of hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive unit of hybrid vehicle capable of increasing a direct torque while preventing a deterioration of fuel consumption at the time of light load, decreasing a torque of a rotary motor and assuring a sufficient reversing drive power. <P>SOLUTION: This drive unit 2 comprises a transmission mechanism 8 for changing a velocity of rotation of an internal combustion engine 3 and transmitting it to a drive power distribution mechanism 7, a first transmission shaft 10 for transmitting a drive power from the internal combustion engine 3 to the transmission mechanism 8 and a second transmission shaft 11 for transmitting a drive power outputted from the transmission mechanism 8 to the drive power distribution mechanism 7. The transmission mechanism 8 has a differential mechanism 23 having two sets of planetary gear mechanisms 21, 22 coupled to each other, a first brake B1 capable of stopping a rotation of a ring gear R1 of the differential mechanism 23, a second brake B2 capable of stopping a rotation of a ring gear R2 and a clutch C for connecting or disconnecting a drive power transmittance from a first transmission shaft 10 to the ring gear R1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hybrid vehicle drive device in which a speed change mechanism is interposed between an internal combustion engine and a power distribution mechanism.

  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. Patent Document 1 exists as a prior art document related to the present invention.

JP 2000-219055 A

  In a drive device applied to a hybrid vehicle, when the torque directly transmitted from the internal combustion engine to the power distribution mechanism (hereinafter referred to as direct torque) is increased in order to reduce the output of the rotating electric machine for driving, the rotation at light load is achieved. Fuel consumption is worsened because the number of electrical paths between electric machines increases. Further, the backward driving force for moving the vehicle backward is also reduced.

  Therefore, the present invention provides a drive device for a hybrid vehicle that can reduce the torque of a rotating electrical machine by increasing the direct torque while preventing deterioration of fuel consumption at light loads and ensuring sufficient reverse drive force. The purpose is to provide.

  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 power distribution mechanism that is interposed between the internal combustion engine and the power distribution mechanism to change the rotation of the internal combustion engine. A first transmission member that transmits power output from the internal combustion engine to the transmission mechanism, a second transmission member that transmits power output from the transmission mechanism to the power distribution mechanism, The transmission mechanism includes: a first brake; a second brake; a clutch for intermittently transmitting power from the first transmission member; a first rotating element coupled to the first transmission member; Connected to transmission member A second rotation element connected to the first transmission member via the clutch, and a third rotation element that can be stopped by the first brake, and a fourth rotation that can be stopped by the second brake. The first rotating element is positioned between the third rotating element and the fourth rotating element and the second rotating element is the fourth rotating element when the rotating elements are arranged on a collinear diagram. The above-described problem is solved by including a differential mechanism in which the respective rotary elements are combined so as to be differentially rotatable with each other so as to be adjacent to the rotary element.

  According to this drive device, when the rotating elements of the speed change mechanism are arranged on the collinear diagram, the first rotating element is located between the third rotating element and the fourth rotating element, and the second rotating element is Adjacent to the fourth rotating element. For this reason, the rotation speed of the second transmission member is stopped by releasing the clutch and stopping the rotation of the third rotation element by the first brake while interrupting the power transmission from the first transmission member to which the internal combustion engine is connected. The power of the internal combustion engine can be transmitted to the power distribution mechanism in a state in which is set higher than the rotational speed of the first transmission member. That is, it is possible to create an overdrive state in which the power of the internal combustion engine is transmitted to the power distribution mechanism with the rotational speed increased. Further, by engaging the clutch and releasing the first brake while the first transmission member and the third rotating element rotate together, the power of the internal combustion engine is transmitted to the power distribution mechanism without changing the rotational speed. be able to. As a result, even if the distribution ratio of the power distribution mechanism is set so that the direct torque increases so as to decrease the torque of the second rotating electrical machine at the time of medium load or high load, the clutch and the first brake are operated to operate the overdrive state. By switching to, fuel consumption deterioration at light load can be prevented. Therefore, it is possible to increase the direct torque while reducing the torque of the rotating electrical machine while preventing deterioration of fuel consumption at light loads.

  Further, the second transmission member can be reversely rotated by stopping the rotation of the fourth rotating element by the second brake while the clutch and the first brake are released. That is, it is possible to perform reverse running by reversing the input from the internal combustion engine side to the power distribution mechanism. In that case, the driving force at the time of reverse can be sufficiently secured by the power of the internal combustion engine and the second rotating electrical machine.

  Further, when the internal combustion engine is started, the clutch is disengaged and the power transmission from the first transmission member to which the internal combustion engine is connected is interrupted, and the rotation of the third rotating element is stopped by the first brake, so that the overdrive state is established. By doing so, it is possible to amplify the torque of the first rotating electrical machine by the speed ratio of the speed change mechanism and crank the internal combustion engine.

  The differential mechanism of the speed change mechanism may be realized with an appropriate configuration. For example, in the differential mechanism, two of the three elements of the two sets of planetary gear mechanisms including the three elements of the sun gear, the ring gear, and the carrier are connected to each other, whereby each of the rotating elements is configured. (Claim 2). As a result, four rotating elements that are differentially rotated with each other are realized. Which of these rotating elements functions as the first to fourth rotating elements is arbitrary.

  For example, two sets of planetary gear mechanisms are provided as two sets of planetary gear mechanisms, one carrier and the other sun gear rotate together, and one sun gear and the other ring gear rotate together. They may be connected to each other (claim 3). In this case, an element in which one carrier and the other sun gear are connected to the first rotating element, an element in which one sun gear and the other ring gear are connected to the second rotating element, and one ring gear. Corresponds to the third rotating element, and the other carrier corresponds to the fourth rotating element. In addition, a single-pinion type planetary gear mechanism and a double-pinion type planetary gear mechanism are provided as two sets of planetary gear mechanisms, and the carriers of these planetary gear mechanisms and the sun gears mutually rotate so as to rotate together. It may be connected (Claim 4). In this case, the element where the carriers are connected is the first rotating element, the element where the sun gears are connected is the second rotating element, one ring gear is the third rotating element, and the other ring gear is the first rotating element. Each corresponds to four rotation elements. According to these aspects, it is possible to realize a differential mechanism having a large setting range of the gear ratio (gear ratio) and high reliability without complicating the configuration.

  As described above, according to the present invention, even if the distribution ratio of the power distribution mechanism is set so that the direct torque increases so as to decrease the torque of the second rotating electrical machine at medium load or high load, By operating the brake and switching to the overdrive state, it is possible to prevent deterioration in fuel consumption at light loads. Therefore, it is possible to increase the direct torque while reducing the torque of the rotating electrical machine while preventing deterioration of fuel consumption at light loads.

(First form)
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 20 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 power distribution mechanism that is interposed between the internal combustion engine 3 and the power distribution mechanism 7 to change the rotation of the internal combustion engine 3. 7, a transmission mechanism 10 that transmits power output from the internal combustion engine 3 to the transmission mechanism 8, and a power transmission mechanism 7 that transmits power output from the transmission mechanism 8. And a second transmission shaft 11 as a second transmission member.

  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 20. 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 S that is an external gear, a ring gear R that is an internal gear disposed coaxially with the sun gear S, and a pinion 15 that meshes with these gears S and R. And a carrier Cr that is freely held. The sun gear S is connected to the first motor / generator 4. The ring gear R is connected to the output shaft 6 so as to be integrally rotatable. The carrier Cr is connected to the second transmission shaft 11.

  The transmission mechanism 8 includes a differential mechanism 23 in which two sets of single pinion planetary gear mechanisms 21 and 22 are combined. 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 arranged coaxially with the sun gear S1, and a pinion 24 that meshes with these gears S1 and R1. And a carrier Cr1 that is held to revolve freely. On the other hand, the second planetary gear mechanism 22 includes a sun gear S2 that is an external gear, a ring gear R2 that is an internal gear disposed coaxially with the sun gear S2, and a pinion 25 that meshes with these gears S2 and R2. And a carrier Cr2 that rotatably supports and revolves. The carrier Cr1 of the first planetary gear mechanism 21 and the sun gear S2 of the second planetary gear mechanism 22 are connected to each other so as to rotate together, and the sun gear S1 of the first planetary gear mechanism 21 and the second planetary gear mechanism 22 are connected. Are connected to each other.

  The speed change mechanism 8 further includes a clutch C that cuts off power transmission from the first transmission shaft 10 and two brakes B1 and B2 for switching modes. The clutch C operates between an engaged state in which the first transmission shaft 10 and the ring gear R21 are connected and a released state in which the connection is released. The clutch C is configured as a friction clutch, and the clutch C is provided with a hydraulic actuator (not shown) for operating the clutch C. The transmission mechanism 8 is provided with a control device for controlling the supply of hydraulic pressure to the actuator, but the illustration thereof is omitted. The type of the clutch C is arbitrary, and for example, it can be configured as a meshing clutch. The first brake B1 can stop the rotation of the ring gear R1 of the first planetary gear mechanism 21. The second brake B2 can stop the rotation of the carrier Cr2 of the second planetary gear mechanism 22.

  In the configuration of the differential mechanism 23 described above, the element in which the carrier Cr1 and the sun gear S2 are connected is the first rotating element according to the present invention, and the element in which the sun gear S1 and the ring gear R2 are connected is the first in accordance with the present invention. For the two rotation elements, the ring gear R1 corresponds to the third rotation element according to the present invention, and the carrier Cr2 corresponds to the fourth rotation element according to the present invention.

  Next, the mode switching performed by the speed change mechanism 8 will be described with reference to FIGS. The drive device 2 is used at an under drive mode (UD mode) used at a medium load and a high load, and at a light load by changing a pattern of operating states of the brakes B1, B2 and the clutch C of the transmission mechanism 8. The overdrive mode (OD mode) and the reverse mode used when the vehicle 1 is reverse are selectively implemented. FIG. 2 shows an engagement table in which each mode is associated with the operating states of the brakes B1 and B2 and the clutch C. In this figure, ◯ indicates the engaged state, and-indicates the released state. As shown in the figure, in the UD mode, the clutch C is held in the engaged state, and the brakes B1 and B2 are held in the released state. In the OD mode, the clutch C is held in the released state, the first brake B1 is held in the engaged state, and the second brake B2 is held in the released state. Further, in the reverse mode, the clutch C is held in the released state, the first brake B1 is held in the released state, and the second brake B2 is held in the engaged state. Note that, when switching between these modes, rotation synchronization control between elements connected by the clutch C is performed after the mode switching, but details thereof are omitted.

  3 to 5 show collinear diagrams for each mode of the speed change mechanism 8. FIG. 3 is a collinear diagram for the UD mode, FIG. 4 is a collinear diagram for the OD mode, and FIG. 5 is a collinear diagram for the reverse mode. Each figure is shown. 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. In these drawings, “IN” means the first transmission shaft 10 and “OUT” means the second transmission shaft 11. In order to facilitate understanding of the functions of the clutch C and the brakes B1 and B2, these elements are schematically shown in the collinear diagrams.

  As shown in FIG. 3, in the UD mode, the clutch C is engaged and the first transmission shaft 10 and the ring gear R1 are connected, so that each rotating element of the differential mechanism 23 rotates integrally. . Therefore, the power from the internal combustion engine 3 is transmitted to the power distribution mechanism 7 via the second transmission shaft 11 without being shifted. Thereby, the direct torque according to the distribution ratio of the power distribution mechanism 7 is set. For this reason, it becomes possible to improve the transmission efficiency at the time of medium load and high load.

  As shown in FIG. 4, in the OD mode, the ring gear R1 is stopped by the first brake B1. Therefore, the power of the internal combustion engine 3 is transmitted to the power distribution mechanism 7 via the second transmission shaft 11 in a state where the rotation of the internal combustion engine 3 is increased by the speed change mechanism 8. Thereby, the torque of the second motor / generator 5 can be reduced. The drive device 2 according to the present embodiment is also configured to function as a start device for the internal combustion engine 3, and at the time of start, the first motor / generator 4 is operated in the OD mode so that the internal combustion engine 3 is operated. Ranking. Since cranking is performed in the OD mode, the torque of the first motor / generator 4 is amplified by the gear ratio of the differential mechanism 23, so that the internal combustion engine 3 can be started with low power consumption.

  As shown in FIG. 5, in the reverse mode, the carrier Cr2 is stopped by the second brake B2. Therefore, the power of the internal combustion engine 3 can be input to the power distribution mechanism 7 by reversing the second transmission shaft 11. As a result, the vehicle 1 can travel backward using the power of the internal combustion engine 3 and the second motor / generator 5. That is, it is possible to secure a sufficient torque at the time of reverse.

  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 speed change mechanism 8 described above is merely an example, and it is possible to change them to other forms that are mechanically equivalent. FIG. 6 shows a modification of the driving device 2. In this modification, the same reference numerals are assigned to configurations common to those described above, and description thereof is omitted.

  FIG. 6 shows an example in which the second planetary gear mechanism 22 is changed to a double pinion type planetary gear mechanism. That is, the transmission mechanism 80 includes a differential mechanism 33 in which a single pinion type first planetary gear mechanism 31 and a double pinion type second planetary gear mechanism 32 are combined. The first planetary gear mechanism 31 rotates a sun gear S31, which is an external gear, a ring gear R31, which is an internal gear disposed coaxially with the sun gear S31, and a pinion 34 that meshes with these gears S31, R31. And a carrier Cr31 that is held to revolve freely. On the other hand, the second planetary gear mechanism 32 includes a sun gear S32 that is an external gear, a ring gear R32 that is an internal gear disposed coaxially with the sun gear S32, a first pinion 35 and a gear that mesh with the gear S32. A carrier Cr32 that holds the pinions 35 and 36 so as to rotate and revolve in a state where the second pinions 36 that engage with R32 are engaged with each other. The carriers of the planetary gear mechanisms 31 and 32 and the sun gears are connected to each other so as to rotate together. In the form of FIG. 6, the element in which the carriers are connected to each other is the first rotating element according to the present invention, the element in which the sun gears are connected to each other is the second rotating element according to the present invention, and the ring gear R31 is in the present invention. The ring gear R32 corresponds to the third rotating element, and the ring gear R32 corresponds to the fourth rotating element. Also in this form, the same effect as the form of FIG. 1 can be exhibited.

  The transmission mechanism and power distribution mechanism shown in FIGS. 1 and 6 are configured as a planetary gear mechanism. By configuring these as planetary gear mechanisms, a highly reliable mechanism with a large transmission ratio (gear ratio) setting range can be obtained without complicating the configuration. There is no limit. 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 mode and the operation state of the clutch and each brake were matched. The figure which showed the alignment chart in UD mode. The figure which showed the alignment chart in OD mode. The figure which showed the alignment chart in reverse mode. The figure which showed the example which changed one planetary gear mechanism of the differential 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 Transmission mechanism 10 First transmission shaft (first transmission member)
11 Second transmission shaft (second transmission member)
20 Drive wheels 21, 31 First planetary gear mechanism 22, 32 Second planetary gear mechanism 23, 33 Differential mechanism

Claims (4)

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 capable of outputting power to a member side; a speed change mechanism interposed between the internal combustion engine and the power distribution mechanism for shifting the rotation of the internal combustion engine and transmitting it to the power distribution mechanism; and the internal combustion engine A first transmission member that transmits the power output from the transmission mechanism to the transmission mechanism, and a second transmission member that transmits the power output from the transmission mechanism to the power distribution mechanism,
The transmission mechanism includes a first brake, a second brake, a clutch for intermittently transmitting power from the first transmission member, a first rotating element coupled to the first transmission member, and a second transmission member. Second rotation element connected, third rotation element connected to the first transmission member via the clutch and capable of stopping rotation by the first brake, and second rotation element capable of stopping rotation by the second brake Including four rotating elements, and when the rotating elements are arranged on a collinear diagram, the first rotating element is located between the third rotating element and the fourth rotating element, and the second rotating element is A drive mechanism for a hybrid vehicle, comprising: a differential mechanism in which the respective rotary elements are combined so as to be differentially rotatable with each other so as to be adjacent to the fourth rotary element.   In the differential mechanism, two of the three elements of the two sets of planetary gear mechanisms including the three elements of the sun gear, the ring gear, and the carrier are connected to each other, whereby each rotating element is configured. The drive device according to claim 1.   As the two sets of planetary gear mechanisms, two sets of single pinion type planetary gear mechanisms are provided, and one carrier and the other sun gear rotate together, and one sun gear and the other ring gear rotate together. The drive device according to claim 2, which are connected to each other.   As the two sets of planetary gear mechanisms, a single-pinion type planetary gear mechanism and a double-pinion type planetary gear mechanism are provided, and the carriers of these planetary gear mechanisms and the sun gears mutually rotate so as to rotate together. The drive device according to claim 2 connected.

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