Hybrid vehicle drive system

Abstract

To provide a hybrid vehicle drive device capable of reducing the necessary capacity of a motor generator and downsizing the whole device.SOLUTION: A hybrid vehicle drive device is equipped with an engine, a first motor generator, a second motor generator that is coupled to a wheel so as to transmit power, and a power distribution device that is provided in a power transmission path between the engine and the wheel, and has a first rotary element, a second rotary element, a third rotary element and a fourth rotary element that can differentially rotate each other. The first motor generator and the first rotary element are coupled, the engine and the second rotary element are coupled, and the wheel and the third rotary element are coupled. The fourth rotary element is fixed by the fixing element so that the rotation speed thereof becomes 0, and a fixed gear stage is formed so that the second rotary element has lower rotation speed lower than that of the third rotary element without giving / receiving electric power between the first motor generator and the second motor generator.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a drive system for a hybrid vehicle. [Background technology]

[0002] Patent document 1 discloses a drive device in which a rotational driving force is input to a first rotating element of a power distributor's three rotating elements (ring gear, sun gear, carrier), the second rotating element is connected to the drive wheels of a vehicle, torque is applied from a first electric motor to a third rotating element, and torque is applied from the second electric motor to an engine output shaft or a power output shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 07-135701 Summary of the Invention [Problem to be solved by the invention]

[0004] There was a demand for technology that could reduce the required capacity of the motor generator and make the entire device more compact.

[0005] The present disclosure has been made in consideration of the above, and aims to provide a drive device for a hybrid vehicle that can reduce the required capacity of the motor generator and make the entire device smaller. [Means for solving the problem]

[0006] The drive device for a hybrid vehicle according to the present disclosure includes an engine, a first motor generator, a second motor generator connected to wheels so as to be able to transmit power, and a power distribution device provided in a power transmission path between the engine and the wheels, and having a first rotating element, a second rotating element, a third rotating element and a fourth rotating element which are capable of differential rotation relative to each other. In the drive device for a hybrid vehicle in which the first motor generator is connected to the first rotating element, the engine is connected to the second rotating element, and the wheels are connected to the third rotating element, the rotation speed of the fourth rotating element is fixed to 0 by a fixed element, and a fixed gear stage is formed so that the third rotating element rotates slower than the second rotating element without the exchange of power between the first motor generator and the second motor generator. Effect of the Invention

[0007] According to the present disclosure, the required capacity of the motor generator can be reduced, and the overall device can be made smaller. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a skeleton diagram that shows a schematic configuration of a hybrid vehicle equipped with a drive device according to an embodiment. [Diagram 2] FIG. 2 is a collinear diagram showing the state of a continuously variable transmission in the drive device of the hybrid vehicle according to the embodiment. [Diagram 3] FIG. 3 is a collinear diagram showing a fixed gear state in the drive device of the hybrid vehicle according to the embodiment. [Figure 4] FIG. 4 is a flowchart showing the operation of the drive device of the hybrid vehicle according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A drive device for a hybrid vehicle according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the components in the following embodiments include those that are easily replaceable by a person skilled in the art, or those that are substantially the same.

[0010] (Device configuration) 1 is a skeleton diagram showing a schematic configuration of a hybrid vehicle 1 equipped with a drive unit according to an embodiment of the present invention. As shown in the figure, the hybrid vehicle 1 includes an engine 10, an output shaft 11, a power distribution mechanism 20, a first motor generator (MG1) 30, a rotating shaft (MG1 shaft) 31, a second motor generator (MG2) 40, a rotating shaft (MG2 shaft) 41, a counter driven gear 42, a counter shaft 43, a counter drive gear 44, a differential 45, and an axle 46 to which wheels are connected.

[0011] In FIG. 1, only the components of the hybrid vehicle 1 that are necessary to realize the present invention are shown, and other components (such as an ECU (Electronic Control Unit), a battery, an inverter, wheels, etc.) are not shown.

[0012] The engine 10 converts the combustion energy of fuel into the rotational motion of the output shaft 11 and outputs the rotational motion. The output shaft 11 is connected to a first carrier 22 of the power distribution mechanism 20, and transmits the rotational motion to the power distribution mechanism 20.

[0013] The power distribution mechanism 20 is disposed between the engine 10 and the axle 46 (wheels), and distributes the power of the engine 10 to the first motor generator 30 and the axle 46 side (output side). The power distribution mechanism 20 has two single-pinion type planetary gear mechanisms. The power distribution mechanism 20 also includes a first rotating element, a second rotating element, a third rotating element, and a fourth rotating element that are capable of differential rotation relative to one another.

[0014] Specifically, the power distribution mechanism 20 includes a first sun gear 21, a first carrier 22, a first ring gear 23, a first pinion gear 24, a second sun gear 25, a second carrier 26, a second ring gear 27, a second pinion gear 28, and a fixed element 29. Among the components of the power distribution mechanism 20, the first sun gear 21, the first carrier 22, the first ring gear 23, and the first pinion gear 24 configure a first planetary gear mechanism. Also, among the components of the power distribution mechanism 20, the second sun gear 25, the second carrier 26, the second ring gear 27, and the second pinion gear 28 configure a second planetary gear mechanism.

[0015] The first sun gear 21 and the second sun gear 25 are connected to the first motor generator 30 via a rotating shaft 31. The first sun gear 21 and the second sun gear 25 function as a “first rotating element” of the power distribution mechanism 20. The first carrier 22 is connected to the engine 10 via an output shaft 11. The first carrier 22 functions as a “second rotating element” of the power distribution mechanism 20.

[0016] The first ring gear 23 is connected to the second carrier 26. The first pinion gear 24 is rotatably supported by the first carrier 22, and meshes with the first sun gear 21 and the first ring gear 23, respectively.

[0017] The second carrier 26 is connected to the first ring gear 23. In addition, the second carrier 26 is connected to an axle 46 (wheels) via the first ring gear 23, a counter driven gear 42, a counter shaft 43, a counter drive gear 44, and a differential 45. This second carrier 26 functions as a “third rotating element” of the power distribution mechanism 20.

[0018] Second ring gear 27 is fixably connected by a fixed element 29. This second ring gear 27 functions as a "fourth rotating element" of power distribution mechanism 20. Second pinion gear 28 is rotatably supported by second carrier 26, and is in mesh with second sun gear 25 and second ring gear 27, respectively.

[0019] The first motor generator 30 and the second motor generator 40 are connected to a battery (not shown) via an inverter (not shown). The inverter is configured with an electric circuit that enables the exchange of electric power between the two motor generators. The second motor generator 40 is also connected to an axle 46 (wheels) so as to be capable of transmitting power.

[0020] The counter driven gear 42 is connected to a counter drive gear 44 via a counter shaft 43. The counter driven gear 42 is also connected to the second motor generator 40 via a rotating shaft 41. The counter drive gear 44 meshes with a differential ring gear 45a of a differential 45. Wheels (drive wheels) (not shown) are connected to the differential 45 via left and right axles 46.

[0021] In the hybrid vehicle 1 equipped with the drive device as described above, the state of the hybrid vehicle 1 can be controlled to a continuously variable transmission state and a fixed gear state.

[0022] 2 is a collinear diagram showing a continuously variable transmission state. As shown in the figure, in this continuously variable transmission state, it is possible to continuously control the gear ratio between the second rotating element (first carrier 22) and the third rotating element (second carrier 26) in the power distribution mechanism 20.

[0023] 3 is a collinear diagram showing the fixed gear state. In this fixed gear state, as shown in the figure, the rotation speed of the fourth rotating element (second ring gear 27) is fixed by the fixed element 29 so as to be zero. Then, without the exchange of electric power between the first motor generator 30 and the second motor generator 40, the fixed gear state is formed so that the third rotating element (second carrier 26) rotates slower than the second rotating element (first carrier 22).

[0024] In addition, in Figures 2 and 3, "S1" indicates the first sun gear 21, "C1" indicates the first carrier 22, "R1" indicates the first ring gear 23, "S2" indicates the second sun gear 25, "C2" indicates the second carrier 26, and "R2" indicates the second ring gear 27.

[0025] (operation) The operation of the drive device of the hybrid vehicle according to the embodiment will be described with reference to Fig. 4. Specifically, the operation described in the figure is mainly performed by the ECU of the hybrid vehicle 1.

[0026] Also, in Figure 3, "Te" is the engine torque, "Tg_max" is the upper limit torque of the first motor generator 30, "ρ1" is the gear ratio of the first planetary gear mechanism that constitutes the power distribution mechanism 20 (specifically, the value obtained by dividing the number of teeth of the first sun gear 21 by the number of teeth of the first ring gear 23), "ρ" is the gear ratio of the power distribution mechanism 20, and "Ne" is the engine speed.

[0027] First, it is determined whether or not "lock lower limit vehicle speed<vehicle speed<lock upper limit vehicle speed" (step S1). The lock lower limit vehicle speed and the lock upper limit vehicle speed are values ​​that are set in advance.

[0028] In step S1, if it is determined that "lock lower limit vehicle speed<vehicle speed<lock upper limit vehicle speed" (Yes in step S1), it is determined whether or not "request Te>Tg_max / (ρ1 / (ρ+1))" (step S2).

[0029] In step S2, if it is determined that "request Te>Tg_max / (ρ1 / (ρ+1))" (Yes in step S2), the engine speed Ne is controlled to a preset lock speed (step S3). Then, it is determined whether the engine speed Ne is equal to the lock speed (step S4).

[0030] In step S4, when it is determined that the engine speed Ne is equal to the lock speed (Yes in step S4), locking is performed (step S5). Specifically, in step S5, the rotation speed of the second ring gear 27 is fixed by the fixing element 29 so as to be 0, and a fixed gear stage is formed so that the second carrier 26 rotates slower than the first carrier 22 without the exchange of electric power between the first motor generator 30 and the second motor generator 40.

[0031] Next, the engine 10 is controlled so that the actual Te (actual engine torque) becomes equal to the required Te (required engine torque) (step S6), and this process is completed.

[0032] If it is determined in step S1 that "lock lower limit vehicle speed < vehicle speed < lock upper limit vehicle speed" is not true (No in step S1), or if it is determined in step S2 that "request Te>Tg_max / (ρ1 / (ρ+1))" is not true (No in step S2), this process is completed. Also, if it is determined in step S4 that the engine speed Ne is not equal to the lock speed (No in step S4), the process returns to step S3.

[0033] In the drive device for the hybrid vehicle according to the embodiment described above, by controlling the first motor generator 30 to a fixed gear stage state (see FIG. 3), the first motor generator 30 receives the torque reaction force of the engine 10 without regenerating. Then, the output of the first motor generator 30 is set to 0 (it only rotates with the engine) and all of the output power of the engine 10 is transmitted to the output side via the power distribution mechanism 20, thereby reducing electrical energy loss. Therefore, the required capacity of the first motor generator 30 and the second motor generator 40 can be reduced, and the overall device can be made more compact.

[0034] Furthermore, when the vehicle is traveling in a fixed gear state (see FIG. 3), there is no exchange of electric power between the first motor generator 30 and the second motor generator 40, and the output power of the engine 10 can be transmitted entirely to the output side via the power distribution mechanism 20. This reduces electrical energy loss and allows the output power of the engine 10 to be transmitted efficiently to the output side.

[0035] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0036] 1 Hybrid vehicles 10 Engine 11 Output shaft 20 Power distribution mechanism 21 First sun gear 22 First Career 23 First ring gear 24 First pinion gear 25 Second sun gear 26 Second Career 27 Second ring gear 28 Second pinion gear 29 Fixed elements 30 First motor generator 31 Rotation axis 40 Second motor generator 41 Rotation axis 42 Counter driven gear 43 Countershaft 44 Counter drive gear 45 Differential 45a Differential ring gear 46 Axles

Claims

[Claim 1] a power distribution device provided in a power transmission path between the engine and the wheels, the power distribution device having a first rotation element, a second rotation element, a third rotation element and a fourth rotation element capable of differentially rotating relative to one another; the first motor generator and the first rotating element are connected to each other; The engine and the second rotating element are connected to each other, In a drive device for a hybrid vehicle in which the wheel and the third rotating element are connected to each other, If "lock lower limit vehicle speed < vehicle speed < lock upper limit vehicle speed" and "required torque > upper limit torque of the first motor generator / (speed ratio of the first planetary gear mechanism constituting the power distribution device / (speed ratio of the power distribution device + 1))", the engine speed is controlled to a preset lock speed, When "engine speed = lock speed", the rotation speed of the fourth rotating element is fixed to 0 by a fixed element, and a fixed gear stage is formed so that the third rotating element rotates slower than the second rotating element without exchange of electric power between the first motor generator and the second motor generator. Hybrid vehicle drive unit.

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