JP5257118B2 - Drive device for hybrid vehicle - Google Patents

Description

  The present invention relates to a drive device for a hybrid vehicle.

  Patent Document 1 discloses a drive device for a hybrid vehicle in which two motor generators and a planetary gear mechanism are arranged on the same axis of an engine.

JP 2002-225578 A

However, in the above prior art, when the engine torque is increased, the size of the motor generator is also increased, so that there is a problem that the axial length (axial dimension) of the drive device is increased.
An object of the present invention is to provide a drive device for a hybrid vehicle that can keep the shaft length short.

In the present invention, the power distribution device is configured by one planetary gear mechanism, and the second motor generator is arranged on a separate shaft with respect to the engine, the first motor generator, and the power distribution device. Furthermore, the shaft connected to the drive wheel is a first shaft, the shaft connected to the second motor generator is the second shaft, and a transmission is provided that changes the rotation of the second shaft and outputs it to the first shaft. This transmission has first and second clutches for switching gear positions, the first clutch is disposed on the first shaft, and the second clutch is disposed on the second shaft.

  Therefore, in the present invention, the second motor generator is disposed on a separate shaft with respect to the engine, the first motor generator, and the power distribution device, so that the shaft length is reduced compared to the case where the second motor generator is disposed coaxially. be able to. Further, the first and second clutches of the transmission are arranged on the first shaft and the second shaft, respectively, so that the first clutch and the second clutch are arranged on a single shaft. The axial length can be kept short compared with the case where a clutch is arranged.

1 is a drive device for a hybrid vehicle according to a first embodiment. 2 is a drive device for a hybrid vehicle according to a second embodiment.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the drive device of the hybrid vehicle of this invention is demonstrated based on the Example shown on drawing.

FIG. 1 illustrates a hybrid vehicle drive apparatus according to a first embodiment.
The vehicle of the first embodiment is a hybrid vehicle having an engine 1 that is an internal combustion engine and two motor generators MG1 and MG2. The output shaft 4 of the engine 1 is connected to the pinion carrier PC of the power distribution device 2 composed of a planetary gear mechanism. The output shaft 5 of the power generation motor generator MG1 is connected to the sun gear SG of the power distribution device 2. The ring gear RG of the power distribution device 2 is connected to the first shaft 6. Engine 1, power distribution device 2, and motor generator MG1 for power generation are arranged on the same axis. The power generation motor generator MG1 is mainly used as a generator, but may be used as a drive motor depending on the traveling state.

  The output shaft of drive motor generator MG2 is integral with second shaft 7 arranged in parallel with first shaft 6. The second shaft 7 is connected to the first shaft 6 via the transmission 3. The first shaft 6 is connected to the drive wheel 10 via a reduction gear 8 and a differential gear 9.

  The transmission 3 is a constantly meshing transmission that transmits power by one of two gear pairs having different transmission ratios. In the first embodiment, a high gear (high speed stage) with a small reduction ratio and a low with a large reduction ratio. A two-speed shift having a gear (low speed) is assumed. The High gear consists of gears 3a1 and 3a2, and the Low gear consists of gears 3b1 and 3b2.

  In the first embodiment, as a clutch for switching the gear ratio, a hydraulic friction clutch (second clutch) 3a is provided between the gear 3a1 and the gear 3a2, and an engagement clutch is provided between the gear 3b1 and the gear 3b2. (First clutch) 3b was provided. The friction clutch 3a rotates integrally with the second shaft 7, connects the second shaft 7 and the gear 3a1 when turned on, and releases the connection between the second shaft 7 and the gear 3a1 when turned off. The engagement clutch 3b connects the gear 3b2 and the first shaft 6 when turned on, and releases the connection between the gear 3b2 and the first shaft 6 when turned off.

  Which gear is selected is controlled by the engagement clutch 3b and the friction clutch 3a. When both the engagement clutch 3b and the friction clutch 3a are off, the clutch is in a released state (neutral state). When the engagement clutch 3b is off, the low gear is selected and when the friction clutch 3a is off, the engagement clutch 3b is off. When the friction clutch 3a is on, the high gear is selected.

  This switching is executed by a shift actuator (not shown). When the high gear is selected, the rotation of the driving motor generator MG2 is transmitted to the first shaft 6 through the high gear pair 3a1, 3a2 without being decelerated so much. On the other hand, when the low gear is selected, the rotation of the driving motor generator MG2 is greatly decelerated through the low gear pair 3b1 and 3b2 and transmitted to the first shaft 6.

  For example, when a shift request from the high gear to the low gear is output, the high gear friction clutch 3a is turned off, and once in the neutral state, the low gear engagement clutch 3b is turned on. When a shift request from the low gear to the high gear is output, the low gear engagement clutch 3b is turned off, and once in the neutral state, the high gear friction clutch 3a is turned on.

Next, the operation will be described.
In the first embodiment, the engine 1, the power distribution device 2, and the power generation motor generator MG1 are arranged on the same axis, and the drive motor generator MG2 is arranged on another axis (second axis 7).
Normally, the size (capacity) of the generator and drive motor is determined by the engine output performance (engine torque). Therefore, when an engine with high output performance is used, the generator and drive motor increase in size as the engine torque increases. Necessary.

  For this reason, for example, when the drive motor generator MG2 is arranged coaxially with the power generation motor generator MG1, the shaft length (axial dimension) becomes longer, so the drive device is placed horizontally (the engine output shaft in the vehicle width direction). In the FF vehicle to be placed in), the in-vehicle property is deteriorated. Therefore, in the first embodiment, the drive motor generator MG2 is arranged on a separate shaft, so that the shaft length of the drive device can be kept short even when the motor generator is increased in size with an increase in engine output. it can.

  Further, in the first embodiment, as a transmission of the driving motor generator MG2, the high gear by the gear 3a1 of the second shaft 7 and the gear 3a2 of the first shaft 6, the gear 3b1 of the second shaft 7, and the first shaft 6 are used. A continuously meshing transmission 3 having a low gear by the gear 3b2 is provided. For example, when a simple planetary gear mechanism is used as a transmission, a large gear ratio cannot be set, so that it cannot contribute to size reduction of drive motor generator MG2. In addition, since the number of parts is large, there is a problem in terms of cost. On the other hand, by using the Ravigneaux type planetary gear mechanism, the degree of freedom in design can be ensured, but the structure becomes complicated and the cost is increased as compared with the simple planetary gear mechanism.

  Therefore, in the first embodiment, by using the constantly meshing transmission 3, the structure can be simplified and the cost can be reduced as compared with the case where the planetary gear mechanism is used. Further, since the gear ratio can be set freely, the size of drive motor generator MG2 can be reduced. Furthermore, the degree of freedom in layout is high.

  Further, in the first embodiment, the clutch 3b that is engaged when the low gear is selected and the friction clutch 3a that is engaged when the high gear is selected are provided as clutches for switching the transmission ratio of the transmission 3.

In the driving apparatus of the first embodiment, when the engine 1 is being driven, the power generation motor generator MG1 performs regenerative operation (power generation), and the drive motor generator MG2 performs power running operation (drive), thereby improving fuel efficiency. . For this reason, as the vehicle speed and the driving torque change, the workload of the engine 1 and the driving motor generator MG2 changes, and the burden on the driving motor generator MG2 increases.
At this time, by switching between the low gear and the high gear, the optimum driving force can be transmitted to the driving wheel 10, and the fuel consumption can be further improved.

  Further, since the friction clutch 3a is provided on the second shaft 7 and the engagement clutch 3b is provided on the first shaft 6, the axial length of the entire drive device is compared with the case where both clutches 3a and 3b are provided on one shaft. Can be shortened.

  Further, the engagement clutch 3b is fastened in the low gear, and the friction clutch 3a is fastened in the high gear. That is, reliable torque transmission can be achieved by the engagement clutch 3b during low-speed traveling, and smooth torque transmission can be achieved by slip engagement of the friction clutch 3a during high-speed traveling.

Next, the effect will be described.
The hybrid vehicle drive device according to the first embodiment has the following effects.
(1) Engine 1, first motor generator MG1, power distribution device 2 connecting engine 1, first motor generator MG1, and drive wheel 10, first shaft 6 connecting to drive wheel 10, and second A motor generator MG2, a second shaft 7 connected to the second motor generator MG2, and a transmission 3 that changes the rotation of the second shaft 7 and outputs it to the first shaft 6 are provided. Thereby, axial length can be suppressed short and deterioration of in-vehicle property can be prevented.

  (2) Always-mesh transmission that transmits power to the transmission 3 by one of a plurality of gear pairs (3a1, 3a2 and 3b1, 3b2) provided on the first shaft 6 and the second shaft 7 and having different gear ratios. Therefore, it is possible to reduce the size of the drive motor generator MG2 and to increase the degree of freedom of layout.

  (3) The transmission 3 has two shift stages, a low gear and a high gear, and the clutch has an engagement clutch 3b that is engaged when the low gear is selected and a friction clutch 3a that is engaged when the high gear is selected. For this reason, both reliable torque transmission during low speed traveling and smooth torque transmission during high speed traveling can be achieved.

  FIG. 2 shows a hybrid vehicle drive device according to the second embodiment. In the second embodiment, the configuration of the transmission is different from that of the first embodiment. In addition, about the part which is common in Example 1, it represents with the same name and the same code | symbol, and abbreviate | omits description.

  The transmission 11 according to the second embodiment includes a high gear that includes a gear 11a1 that is coupled to the second shaft 7 and a gear 11a2 that is coupled to the first shaft 6, and a low gear that is coupled to the second shaft 7. 11b1 and a gear 11b2 connected to the first shaft 6 were configured.

  In the second embodiment, the dog clutch 11c is provided on the second shaft 7 as a clutch for switching the gear ratio. The dog clutch 11c includes a synchro mechanism, a position where the second shaft 7 and the gear 11a1 are connected, a position where the second shaft 7 and the gear 11b1 are connected, and the second shaft 7 with respect to both the gears 11a1 and 11b1. Move to the relative rotation position. When the second shaft 7 and the gear 11a1 are connected, the low gear is selected, and when the second shaft 7 and the gear 11b1 are connected, the high gear is selected.

  When the high gear is selected, the rotation of the driving motor generator MG2 is transmitted to the first shaft 6 through the high gear pair 11b1 and 11b2 without being decelerated so much. On the other hand, when the low gear is selected, the rotation of the driving motor generator MG2 is greatly decelerated through the low gear pair 11a1 and 11a2 and transmitted to the first shaft 6.

Next, the operation will be described.
In the second embodiment, the dog clutch 11 c that switches the transmission ratio of the transmission 11 is disposed on the second shaft 7. For this reason, the shaft length of the first shaft 6 can be shortened compared with the first embodiment in which the engagement clutch 3b is disposed on the first shaft 6 and the friction clutch 3a is disposed on the second shaft 7. The degree of freedom of layout of the gear 8 can be increased.

Next, the effect will be described.
In addition to the effects (1) to (3) of the first embodiment, the hybrid vehicle drive device of the second embodiment has the following effects.

  (4) The transmission 11 includes the dog clutch 11c that switches the gear position. Since the dog clutch 11c is disposed on the second shaft 7, the shaft length of the first shaft 6 can be shortened, and the gear 11 is disposed on the first shaft 6. The degree of freedom in layout of the reduction gear 8 can be increased.

(Other examples)
The best mode for carrying out the present invention has been described above based on the embodiments. However, the specific configuration of the present invention is not limited to the embodiments and is within the scope of the invention. Any design changes are included in the present invention.

For example, in the first embodiment, the friction clutch 3a is disposed on the second shaft 7 and the engagement clutch 3b is disposed on the first shaft 6. However, both the friction clutch 3a and the engagement clutch 3b are disposed on the second shaft 7. By arranging in 7, it is possible to obtain the same effects as in the second embodiment.
In the first and second embodiments, the transmission is a two-speed shift between High and Low, but more shift stages may be set.

MG1 Motor generator for power generation
MG2 Motor generator 1 for driving 1 Engine 2 Power distribution device 3 Transmission 3a Friction clutch (second clutch)
3b engagement clutch (first clutch)
6 First shaft 7 Second shaft 10 Drive wheel 11 Transmission 11c Dog clutch (clutch)

Claims (3)

Engine,
A first motor generator;
A power distribution device including one planetary gear mechanism having a first rotation element connected to the engine, a second rotation element connected to the first motor generator, and a third rotation element connected to a drive wheel;
A first shaft connected to the drive wheel;
A second motor generator;
A second shaft connected to the second motor generator;
A transmission for changing the rotation of the second shaft and outputting it to the first shaft;
With
The transmission has first and second clutches for switching gears,
The hybrid vehicle drive device characterized in that the first clutch is disposed on the first shaft and the second clutch is disposed on the second shaft. The drive device for a hybrid vehicle according to claim 1,
The hybrid vehicle drive device characterized in that the transmission is a constant-mesh transmission that transmits power by any of a plurality of gear pairs with different transmission ratios provided on the first shaft and the second shaft. . The drive device for a hybrid vehicle according to claim 1,
The transmission has two speed stages, a low speed stage and a high speed stage,
The first clutch is an engagement clutch that is engaged when a low speed stage is selected,
2. The hybrid vehicle drive device according to claim 1, wherein the second clutch is a friction clutch that is engaged when the high speed stage is selected.

Images