JP7424735B2 - Power transmission device for hybrid vehicles - Google Patents

Description

The present invention relates to a power transmission device for a hybrid vehicle that uses both an engine and a motor as a driving source.

Hybrid vehicles equipped with an engine and a motor as driving sources are widely known. The power transmission device of this hybrid vehicle is based on the power transmission device of an engine-driven vehicle, and the power of the engine and the power of the motor are selectively input to a continuously variable transmission (CVT).

However, since the continuously variable transmission is a belt type and causes power transmission loss, in a configuration where the power of the motor is transmitted to the output shaft via the continuously variable transmission, the running drive efficiency (power running) by the motor Another problem is that the regeneration efficiency during deceleration decreases due to the influence of transmission loss of the continuously variable transmission mechanism.

Regarding this point, the applicant of the present invention has proposed in Patent Document 1 a bypass that directly transmits the power of the motor to the output shaft so that the power of the motor is transmitted to the output shaft without passing through the continuously variable transmission. It is disclosed that a means of communication is provided. In Patent Document 1, as a bypass transmission means, a spur gear is provided on the input shaft via a clutch, and the spur gear on the input shaft side is connected to the spur gear provided on the carrier of the planetary gear mechanism provided on the output shaft. It meshes with the

Unexamined Japanese Patent Publication No. 2018-172095

In the configuration of Patent Document 1, since the power of the motor is directly transmitted to the output shaft, there is an advantage that the drive efficiency when driving the motor can be improved, and the regeneration efficiency during deceleration can be improved.

The present invention is a development of the idea of Patent Document 1, and aims to improve the controllability and running stability during motor running and expand the variation of running modes.

The present invention is
"An engine and a motor as a power source, an input shaft that transmits power to a continuously variable transmission, an output shaft that transmits power from the continuously variable transmission, and a connection and disconnection of power transmission from the engine to the input shaft. and a bypass transmission means for directly transmitting the power of the motor to the output shaft ,
The bypass transmission means includes a driving planetary gear mechanism having a driving sun gear concentric with the input shaft, and a driven planetary gear mechanism having a driven sun gear concentric with the output shaft. It is transmitted to the driven carrier of the driven planetary gear mechanism via the driven carrier of the driven planetary gear mechanism.
This is the basic configuration.

In the present invention , the first clutch may be of the friction plate type or gear type, or the torque converter may also be used as the clutch.

In the above basic configuration , the present invention has the following features:
" The main drive carrier of the main drive planetary gear mechanism is formed in a hollow shape, and a second clutch is disposed inside the drive carrier for connecting and disconnecting power transmission between the main drive carrier and the input shaft, and The driven carrier is also formed in a hollow shape, and a third clutch that can connect and disconnect power transmission between the driven carrier and the output shaft is disposed inside the driven carrier.
The structure is as follows.

According to the present invention, since the power of the motor can be directly transmitted to the output shaft, the drive efficiency and regeneration efficiency of the motor can be improved.

Now, motors have a rotation range in which they are efficient, but generally it is difficult to maintain stable rotation in a low speed rotation range below a certain level. In this regard, in the present invention, the rotation of the motor can be transmitted to the driven planetary gear mechanism of the output shaft while being decelerated by the driving planetary gear mechanism, so the output shaft can be rotated while the motor is rotating in a stable rotation range. Can be rotated at low speed.

Therefore, when starting a car in motor drive mode or driving at low speed in traffic jams, it is possible to improve transmission efficiency and regeneration efficiency, secure the necessary torque, and realize stable driving.

Furthermore, in the present invention , not only can the first clutch be switched to switch between the engine driving mode and the motor driving mode, but also the continuously variable transmission can be switched in the motor driving mode by combining the engagement and disconnection of the first to third clutches. The rotation speed is changed to a rotation speed that is a combination of the transmission via a continuously variable transmission and the transmission via a bypass transmission means, or the rotation speed is a combination of a continuously variable transmission and a bypass transmission in engine drive mode. It is possible to realize a variety of driving modes, such as multiple speed changes, transmitting engine power to a continuously variable transmission, and assisting the rotation of the output shaft with the motor.

Therefore, by utilizing the characteristics of engine running and motor running, it is possible to realize detailed running modes depending on speed and load. As a result, the functionality of the hybrid vehicle can be improved.

FIG. 2 is a schematic diagram showing a neutral state of the embodiment. FIG. 3 is a schematic diagram showing a motor running mode of the embodiment. FIG. 3 is a schematic diagram showing an engine running mode of the embodiment. FIG. 3 is a schematic diagram showing a hybrid driving mode in which engine driving is assisted by a motor.

Next, embodiments of the present invention will be described in detail based on the accompanying drawings.

(1).Structure of the power transmission device The power transmission device is housed in a mission case 2 (see Figure 1) fixed to the rear of the main body of the engine 1 (cylinder block and oil pan). 3 is attached to the mission case 2 with its rotation axis parallel to the crankshaft 4. Note that although the mission case 2 and the motor 3 partially overlap in FIG. 1, they are offset in a direction perpendicular to the plane of the paper. Although it goes without saying, power is supplied to the motor 3 from the battery via the inverter.

A rotary damper 5 having a starter gear is fixed to the crankshaft 4, and an engine output relay shaft 6 is fixed to the rotary damper 5. The transmission case 2 rotatably holds an input shaft 7 that is concentric with the engine output relay shaft 6. The input shaft 7 is provided with a main drive planetary gear mechanism 8 and a first spur gear 9 located downstream thereof. The first spur gear 9 meshes with a second spur gear 12 fixed to a primary shaft (input shaft) 11 of a continuously variable transmission (CVT) 10. Although the first spur gear 9 and the second spur gear 12 have the same number of teeth, they may have different numbers of teeth.

The continuously variable transmission 10 has a secondary shaft (output shaft) 13 that is parallel to the primary shaft 11, and a main variable pulley 14 provided on the primary shaft 11 and a variable driven pulley 15 provided on the secondary shaft 13. A belt 16 having a trapezoidal cross section is wound around it.

An output shaft 18 concentric with the secondary shaft 13 is rotatably held in the mission case 2, and a driven planetary gear mechanism 19 is disposed astride the secondary shaft 13 and the output shaft 18. There is. Furthermore, a differential shaft 20 parallel to the output shaft 18 is rotatably arranged in the mission case 2, and the rotation of the output shaft 18 is controlled via a third spur gear 21 and a fourth spur gear 22. Power is transmitted to the differential shaft 20. The third spur gear 21 has a much smaller diameter than the fourth spur gear 22, and the rotation of the output shaft 18 is transmitted to the differential shaft 20 at a reduced speed.

An axle shaft 24 is connected to the differential shaft 20 via a differential gear 23. The automobile of the embodiment is a front wheel drive system, but in the case of a rear wheel drive system, power is transmitted from the output shaft 18 to the drive shaft via a bevel gear mechanism, and from the drive shaft to the differential shaft via the bevel gear mechanism. Power is transmitted to.

Power transmission between the engine output relay shaft 6 and the output shaft 18 is performed via the first clutch 25. The first clutch 25 is of a friction plate type, and is composed of a movable clutch body 25a spline-fitted to the engine output relay shaft 6, and a fixed clutch body 25b fixed to the output shaft 18. is slid by a shifter (not shown), thereby connecting and disconnecting power transmission from the engine output relay shaft 6 to the output shaft 18.

Further, the first clutch 25 is of a single-plate or multi-plate friction plate type, and can adjust the rotation ratio between the engine output relay shaft 6 and the output shaft 18 by utilizing slippage. Therefore, the first clutch can also be used as a torque converter. It is also possible to use the torque converter as the first clutch.

The main drive planetary gear mechanism 8 includes a main drive sun gear 27 provided on a cylindrical body 26 relatively rotatably held on the output shaft 18, and a plurality of drive sun gears (4 gears) meshed with the drive sun gear 27 and a drive internal gear (ring gear) 28. It has a main drive carrier 30 in which a group of main drive planet gears 29 is rotatably held, and the main drive carrier 30 is held in a relatively rotatable manner to the output shaft 18. has been done. The driving internal gear 28 is fixed to the transmission case 2. The main drive planetary gear 29 is provided on a support shaft 29a that projects from the main drive carrier 30.

The driving carrier 30 has a hollow structure with an inner ring 36 , and a fifth spur gear 31 is provided on the outer periphery. The fifth spur gear 31 meshes with a sixth spur gear 33 provided on the driven carrier 32 of the driven planetary gear mechanism 19 . Further, a seventh spur gear 26a is provided on the cylinder 26 constituting the driven planetary gear mechanism 19, and an eighth spur gear 3a provided on the motor 3 is meshed with the seventh spur gear 26a. Therefore, the power of the motor 3 is transmitted to the sun gear 27 of the main drive planetary gear mechanism 8.

The rotation of the main drive carrier 30 in the main drive planetary gear mechanism 8 can be transmitted to the input shaft 7 via the second clutch 35 disposed therein . The second clutch 35 is composed of a second movable clutch body 35 a slidably attached to the output shaft 18 by spline fitting, and a movable fixed clutch body 35 b provided on the inner ring 36 of the motive carrier 30 . There is. The second clutch 35 may be of a mesh type or a friction plate type.

The second movable clutch body 35a is slid by an annular shifter exposed on the outer periphery of the main drive carrier 30 .

The driven planetary gear mechanism 19 also has a hollow driven carrier 32, and one end of the driven carrier 32 is provided with a cylindrical body 32a, and a sixth spur gear 33 is provided on this cylindrical body 32a. The sixth spur gear 33 meshes with the fifth spur gear 31, but the sixth spur gear 33 has an outer diameter that is a fraction of that of the fifth spur gear 31. Therefore, the rotation of the driving carrier 30 is increased several times in speed and is transmitted to the driven carrier 32.

A driven sun gear 37 is fixed to a portion of the secondary shaft 13 surrounded by the driven planetary gear mechanism 19, and a plurality of (three or four) driven planetary gears 38 mesh with the driven sun gear 37. Each driven planetary gear 38 is rotatably provided on a support shaft 38a that projects inward from the inner surface of a side plate 37 of the driven carrier 32 facing the driven variable pulley 15. Each driven planetary gear 38 meshes with a driven internal gear 39. The driven internal gear 39 is held on the inner peripheral surface of the driven carrier 32 so as to be relatively rotatable. Therefore, the driven internal gear 39 is arranged inside the driven carrier 32.

Power transmission from the driven internal gear 39 to the output shaft 18 is connected/disconnected by a third clutch 40 disposed inside the driven carrier 32 . The third clutch 40 is a mesh type or a friction type, and includes a third movable clutch body 40a slidably attached to the output shaft 18 by spline fitting, and a third movable clutch body 40a provided in a cylindrical body 39a having a driven internal gear 39. 3 fixed clutch body 40b. The third movable clutch body 40a is slid by a shifter exposed outside the driven carrier 32.

Further, the power transmission device includes a brake 41 that stops rotation of the driven carrier 32. The brake 41 may be a mesh type or a friction type.

(2).Description of operation Next, the operation of the power transmission device will be explained. In the following, for each clutch 25, 35, 40, the engaged state in which power is transmitted is assumed to be ON, the disengaged state in which power transmission is interrupted is assumed to be OFF, and for the brake 41, the driven carrier 32 is locked in a non-rotatable manner. The state in which this is done is considered to be ON, and the state in which the driven carrier 32 is rotatably held is considered to be OFF.

FIG. 1 shows a neutral state, in which the clutches 25, 35, and 40 are disengaged and OFF, and the brake 41 is also OFF (in the neutral state, the brake 41 is ON and the driven (The rotation of the carrier 32 may be stopped.)

FIG. 2 shows a motor direct driving mode, and in this mode, the first clutch 25 and the second clutch 35 are OFF, and the third clutch 40 is ON. Further, the brake 41 is turned off.

In this mode, the power transmission of the engine 1 to the input shaft 7 is cut off, and the power of the motor 3 is transmitted to the main drive sun gear 27, the main drive planet gear 29, the main drive carrier 30, the driven carrier 32, the driven planet gear 38, and the driven internal gear. 39, third clutch 40, and output shaft 18 in this order. In this case, the driven planet gear 38 is meshed with the driven sun gear 37, but since the driven carrier 32 is in a idle state with respect to the secondary shaft 13, the driven planet gear 38 is rotated with respect to the driven sun gear 37. As a result, no rotational force acts on the driven sun gear 37. Therefore, the rotation of the motor 3 will not flow back to the secondary shaft 13.

Since the driven internal gear 39 is integrated with the output shaft 18 via the third clutch 40, the driven carrier 32 and the output shaft 18 do not rotate relative to each other, and as a result, the output shaft 18 rotates at the same rotation speed as the driven carrier 32.

The rotation speed of the output shaft 18 is controlled by controlling the rotation speed of the motor 3. However, since the power of the motor 3 is directly transmitted to the output shaft 18 without passing through the continuously variable transmission 10, power loss is reduced. Without this, it can contribute to improving fuel efficiency and regeneration efficiency.

Further, the ratio of the rotation speed of the motor 3 to the rotation speed of the main drive carrier 32 is determined by the ratio of the number of teeth of the main drive planetary gear 29 and the number of teeth of the main drive internal gear 28, while the ratio of the number of rotations of the main drive carrier 30 and the driven carrier 32 The ratio of the rotational speed of is determined by the ratio of the number of teeth of the fifth spur gear 31 and the number of teeth of the sixth spur gear 33, so by setting these numbers of teeth appropriately, the motor 3 can be rotated efficiently. , an appropriate torque can be transmitted to the output shaft 18.

FIG. 3 shows an engine running mode using the continuously variable transmission 10. In this mode, the first clutch 25 and the third clutch 40 are ON, and the second clutch 35 is OFF. Since the motor 3 is not driven, the brake 41 is ON (locked). Therefore, the carriers 32, 30 of the planetary gear mechanisms 8, 19 do not rotate.

In this mode, the power of the engine 1 is transmitted through the first clutch 25, input shaft 7, primary shaft 11, continuously variable transmission 10, secondary shaft 13, driven sun gear 37, driven planetary gear 38, third clutch 40, and output shaft. Power is transmitted in the order of 18. Since the driven carrier 32 does not rotate, the rotation of the secondary shaft 13 is transmitted to the output shaft 18 at a reduced speed according to the ratio of the number of teeth of the driven planetary gear 38 and the number of teeth of the driven internal gear 39.

When a car starts in engine running mode, a large load is applied to the engine 1 at the time of starting, but in this case, by keeping the rotation speed (torque) of the engine 1 at a certain level and letting the first clutch 25 slip, The rotation speed of the input shaft 7 may be gradually increased. If a torque converter is provided, such control is not necessary. Note that even when a torque converter is provided, it is preferable to provide the first clutch 25.

FIG. 4 shows a hybrid driving mode in which the driving force of the engine 1 is assisted by the rotation of the motor 3. In this mode, the first to third clutches 25, 35, and 40 are ON, and the brake 41 is OFF.

In this mode, the power of the engine 1 is transmitted to the output shaft 18 via the continuously variable transmission 10, but the power is also transmitted to the driven carrier 32 of the driven planetary gear mechanism 19 via the main drive planetary gear mechanism 8. Therefore, compared to the engine running mode, the rotation speed (or torque) of the output shaft 18 increases by the rotation of the driven carrier 32. Therefore, it is useful when accelerating or starting on a slope.

Although not shown, this embodiment also executes a motor running split mode in which the rotation of the motor 3 is branched and transmitted from both planetary gear mechanisms 8 and 19 to both the continuously variable transmission 10 and the driven planetary gear mechanism 19. can. In this mode, the first clutch 25 is OFF, the second clutch 35 and the third clutch 40 are ON, and the brake 41 is OFF.

In this mode, part of the power of the motor 3 is transmitted to the second clutch 35, the input shaft 7, the primary shaft 11, the continuously variable transmission 10, the secondary shaft 13, the driven sun gear 37, the driven planetary gear 38, and the driven internal gear 39. , third clutch 40, and output shaft 18 in this order.

Further, the other part of the power of the motor 3 is transmitted to the main drive sun gear 27, the main drive planet gear 29, the main drive carrier 32, the driven carrier 32, the driven planet gear 38, the driven internal gear 39, the 3 clutch 40 to the output shaft 18.

In this motor running split mode, the secondary shaft 13 and the driven sun gear 37 rotate, so the rotational speed of the output shaft 18 (driven The rotation speed of the internal gear 39 is determined.

In this motor drive split mode, the ratio between the rotation speed of the input shaft 7 and the rotation speed of the secondary shaft 13 can be changed by the continuously variable transmission 10, so that the rotation control by the motor 3 and the rotation control by the continuously variable transmission 10 are performed. In combination with this, it is possible to maintain the output of the motor 3 at the minimum necessary level while achieving fine rotation control according to the traveling speed and load. Therefore, the motor 3 can be used efficiently.

Furthermore, in this embodiment, an engine running split mode in which the power of the engine 1 is divided and transmitted to the continuously variable transmission 10 and the driven planetary gear mechanism 19 can also be executed. In this mode, the first clutch 25 and the second clutch 35 are ON, the third clutch 40 is OFF, and the brake 41 is OFF.

Part of the engine power is transmitted to the driven sun gear 37, driven planetary gear 38, and driven internal gear 39 via the continuously variable transmission 10, and the other part of the engine power is transmitted to the driven sun gear 27, the driven carrier 32, the driven carrier 32, the driven planetary gear 38, and the driven internal gear 39 in this order. Then, as in the case of the motor running split mode, the number of rotations of the output shaft 18 (the number of rotations of the driven internal gear 39) is determined based on the ratio of the number of teeth of the driven sun gear 37 and the number of teeth of the driven internal gear. It is decided.

Therefore, by executing this mode, for example, when the running load is low, power loss caused by the continuously variable transmission 10 can be suppressed and fuel efficiency can be improved. Note that in the engine running split mode, the main drive carrier 30 and the main drive planet gear 29 are rotating, but the main drive planet gear 29 revolves around the main drive sun gear 27 in an idle state, so the power of the engine 1 is transmitted to the motor 3. Never.

As explained above, in this embodiment, since the output shaft 18 can be directly driven by the motor 3, it is possible to suppress power loss of the motor 3 and improve regeneration efficiency, but the clutches 25, 35, 40 and the brake 41, various driving modes can be realized and the engine and motor 3 can be used efficiently. This makes it possible to improve fuel efficiency while ensuring running stability.

The present invention can be embodied in various other ways. For example, it is also possible to provide a clutch in the path that transmits the rotation of the motor to the active sun gear. When the engine rotation is transmitted to the main drive sun gear 27 in the engine running mode, it is best to turn off the motor circuit and let the motor run idly.If you want the motor to regenerate during deceleration in the engine running mode, the motor All you have to do is close the circuit and make it function as a generator.

The present invention can be embodied in a power transmission device for a hybrid vehicle. Therefore, it can be used industrially.

1 Engine 2 Mission case 3 Motor 4 Crankshaft 6 Engine output relay shaft 7 Input shaft 8 Main driven planetary gear mechanism 10 Continuously variable transmission 11 Primary shaft 13 Secondary shaft 18 Output shaft 19 Driven planetary gear mechanism 20 Differential shaft (differential shaft)
25 First clutch 27 Driven sun gear 28 Driven internal gear 29 Driven planetary gear 30 Driven carrier 32 Driven carrier 35 Second clutch 37 Driven sun gear 38 Driven planetary gear 39 Driven internal gear 40 Third clutch 41 Brake (lock clutch)

Claims (1)

An engine and a motor as a power source, an input shaft that transmits power to a continuously variable transmission, an output shaft that transmits power from the continuously variable transmission, and a connection/disconnection of power transmission from the engine to the input shaft. comprising a first clutch and a bypass transmission means for directly transmitting the power of the motor to the output shaft,
The bypass transmission means includes a driving planetary gear mechanism having a driving sun gear concentric with the input shaft, and a driven planetary gear mechanism having a driven sun gear concentric with the output shaft. A power transmission device for a hybrid vehicle in which power is transmitted to a driven carrier of a driven planetary gear mechanism via a driving carrier of a driven planetary gear mechanism,
The main drive carrier of the main drive planetary gear mechanism is formed in a hollow shape, and a second clutch is disposed therein to connect and disconnect power transmission between the main drive carrier and the input shaft. The driven carrier is also formed in a hollow shape, and a third clutch that can connect and disconnect power transmission between the driven carrier and the output shaft is disposed inside the driven carrier.
Power transmission device for hybrid vehicles.

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