JP2004161053A - Drive mechanism for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive mechanism for a hybrid vehicle capable of avoiding shocks at gear shifting while keeping the capacity of a motor generator small. <P>SOLUTION: The drive mechanism comprises a first shaft connected to an output shaft of an engine 11, a second shaft connected to a vehicle drive shaft 13, a gear train 27 for transmitting the rotation torque of the motor generator 12 to the second shaft at a given gear ratio, a planet gear 18 having a sun gear, a carrier and a ring gear, with the carrier being linked with the first shaft and the ring gear connected to the second shaft, and a dog-clutch 33 capable of switching between a first switching position that connects the motor generator 12 to the sun gear and puts the gear train 27 into a state of cutting off transmission of rotation torque and a second switching position that removes the motor generator 12 from the sun gear and puts the gear train 27 into a state of being able to transmit the rotation torque. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention belongs to the technical field of a drive device for a hybrid vehicle including an engine, a motor generator, a differential mechanism, and a transmission mechanism including a gear train.
[0002]
[Prior art]
In recent years, hybrid vehicles (HEV) equipped with a combination of an engine and a motor generator have been put into practical use due to demands for low pollution, cruising distance, and energy supply infrastructure.
Among the HEV system configurations, an HEV system based on an automatic MT that automates a shift operation of an existing manual transmission (hereinafter, MT) has been considered. However, a problem of the automatic MT is a shift shock caused by a torque interruption during a shift. Therefore, there is a system that reduces a shift shock by using a motor generator that realizes the HEV function.
For example, it is possible to reduce a shift shock by incorporating a motor generator into the automatic MT and assisting the motor generator when the driving force of the engine is interrupted during a gear shift (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-10-217779 (page 1, FIG. 1).
[0004]
[Problems to be solved by the invention]
However, in the conventional hybrid vehicle drive device, when the capacity of the motor generator that assists at the time of shifting when the driving force of the engine is interrupted is small, sufficient assist cannot be performed, and shift shock cannot be sufficiently reduced.
Further, since the maximum assist amount is defined by the motor generator power, there is a difference in the shifting performance between the 1-2 shifting with a large torque step and the 5-6 shifting with a small torque step during shifting.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a drive device for a hybrid vehicle that can avoid a shift shock while suppressing the capacity of a motor generator.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, according to the present invention, a first shaft connected to an output shaft of an engine, a second shaft connected to a vehicle drive shaft, and a rotational torque of a motor generator are fixed to the second shaft at a constant speed ratio. A rotary torque transmission mechanism for transmitting power to a shaft, a three-rotation element, a first rotation element connected to the first shaft, and a second rotation element connected to the second shaft. A moving mechanism, a first switching position for connecting the motor generator to a third rotating element of the differential mechanism and interrupting transmission of the rotating torque by the rotating torque transmitting mechanism, and moving the motor generator from the third rotating element. And a switching mechanism that can be switched to a second switching position that allows the transmission of the rotational torque by the rotational torque transmitting mechanism while being separated.
[0007]
Here, the “differential mechanism” is a mechanism that allows a differential while maintaining a predetermined relationship even when three input / output rotations are different, and for example, a planetary gear having a sun gear, a carrier, and a ring gear as rotating elements. Say.
[0008]
The “motor-generator rotating torque transmission mechanism” refers to, for example, a gear train having a constant gear ratio, which is provided between the output shaft of the motor generator and the second shaft.
[0009]
The “switching mechanism” is a mechanism that switches the driving force transmission path by external switching control, and is, for example, a dog clutch.
[0010]
【The invention's effect】
Therefore, in the drive device for a hybrid vehicle of the present invention, the rotational torque of the motor generator can be used for controlling the vehicle driving force in two different forms.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment for realizing a drive device for a hybrid vehicle according to the present invention will be described below with reference to the drawings.
[0012]
(First embodiment)
First, the configuration will be described.
FIG. 1 is an overall system diagram showing a drive device for a hybrid vehicle according to a first embodiment. The engine 11 is a prime mover such as an internal combustion engine, and generates a driving force.
The motor generator 12 is both a motor and a generator, and is capable of generating and powering. The motor generator control device 36 is an inverter or the like, includes an energy storage device 37, and supplies power to the motor generator 12, receives charging, and the like. The energy storage device 37 is generally a battery or a capacitor.
[0013]
The vehicle drive shaft 13 is a shaft that transmits driving force to the differential gear 14, and the driving force that has passed through the differential gear 14 is transmitted to driving wheels 15, and the vehicle travels.
[0014]
The clutch 16 is a device that transmits or interrupts the driving force of the engine 11 by frictional force, and can change the transmission rate by sliding. The control is performed by the clutch actuator 45.
[0015]
The automatic MT 17 has a parallel two-axis configuration. One axis is connected to the engine 11 via the clutch 16, and the other axis is connected to the vehicle drive shaft 13. The automatic MT 17 has a plurality of gear stages (rotary torque transmission mechanisms) 21, 22, 23, 24, and 25 having different gear ratios. Here, the speed stages 21, 22, 23, and 24 are forward speed stages, and the speed stage 25 is a reverse speed stage.
The automatic MT 17 has dog clutches 30, 31, and 32 as fastening devices, and transmits the driving force of the engine 11 to the vehicle drive shaft 13 by fastening the dog clutches 30, 31, and 32 to adjacent gears. can do. Here, the dog clutch 30 switches directly to the gear stage 24 (rotational torque transmission mechanism with gear ratio 1), the dog clutch 31 switches between the gear stage 22 and the gear stage 23, and the dog clutch 32 switches between the gear stage 21 and the gear stage 25. Is switched.
[0016]
The dog clutches 30, 31, 32 are controlled to a neutral position, a first engagement position, and a second engagement position by dog clutch actuators 40, 41, 42, respectively. For example, taking the dog clutch 32 as an example, the neutral position shown in FIG. 2A, the first engagement position to the gear 25 shown in FIG. 2B, and the gear 21 shown in FIG. Is controlled by the dog clutch actuator 42.
[0017]
The one-way clutch 19 is a device that restricts rotation of the shaft of the automatic MT 17 connected to the engine 11 in a direction opposite to the rotation direction of the engine 11. When the one-way clutch 19 is operated when only the motor generator 12 travels, the planetary gear 18 becomes a fixed gear by generating a reaction force on the carrier shaft of the planetary gear 18, and the driving force of the motor generator 12 is amplified to increase the vehicle power. Transmission to the drive shaft 13 becomes possible.
[0018]
The planetary gear 18 includes three shafts, each of which is called a sun gear shaft, a carrier shaft, and a ring gear shaft from the center. In this configuration, the sun gear shaft is connected to the motor generator 12, the carrier shaft is connected to the engine 11, and the ring gear shaft is connected to the vehicle drive shaft 13 via a gear train 26.
[0019]
On a sun gear shaft (on an output shaft) connected to the motor generator 12, a dog clutch 33 (switching mechanism) and a gear train (rotary torque transmitting mechanism for motor generator) 27 are present. The dog clutch 33 is controlled to switch between the following three positions by a dog clutch actuator 43.
(1) When the dog clutch 33 is at the first switching position, which is the neutral position, the motor generator 12 is connected to the sun gear of the planetary gear 18.
(2) When the dog clutch 33 is in the second switching position where it is connected to the gear train 27, the motor generator 12 is disconnected from the sun gear of the planetary gear 18 and connected to the vehicle drive shaft 13 via the gear train 27. At this time, the planetary gear 18 enters a free-run state because no torque is generated on the sun gear shaft.
(3) When the dog clutch 33 is in the third switching position where it is connected to the ring gear shaft, the rotation speeds of the respective shafts of the planetary gear 18 match, and the driving force of the engine 11 and the motor generator 12 is combined by the planetary gear 18. , To the vehicle drive shaft 13 via the gear train 26. That is, when the dog clutch 33 is connected to the gear train 26, the planetary gear 18 and the gear train 26 form one shift speed.
[0020]
The engine input shaft speed detector 34 and the vehicle drive shaft speed detector 35 detect the speed of the input / output shaft of the automatic MT 17.
[0021]
The vehicle control device 38 issues an engine output command, a motor generator power generation / assist / regenerative command, a gear shift command, and the like based on the driver's intention and the vehicle speed.
[0022]
Although not shown, the engine 11 has a starter motor. It is also possible to push the motor generator 12 while the vehicle is running, but at that time, it is very difficult to keep the driving force constant. If the motor running by the motor generator 12 is abandoned, the engine 11 is started by the motor generator 12 and can be started by the cooperative control of the engine 11 and the motor generator 12.
[0023]
Further, the dog clutch 33 is set to the first switching position which is the neutral position, and the driving force of the engine 11 is transmitted to the vehicle drive shaft 13 via the planetary gear 18. At this time, by controlling the torque of the engine 11 and controlling the number of revolutions of the motor generator 12, the number of revolutions of the gear train 26, which is the output stage, can be continuously controlled from zero to a certain low speed.
[0024]
Next, the operation will be described.
[0025]
[Driving force transmission path switching action]
In the configuration of the first embodiment of the present invention, the transmission path of the driving force between the engine 11 and the motor generator 12 is switched by changing the switching position of the dog clutch 33. The four main functions ((1) motor running function, (2) power generation / assist function, (3) regenerative braking function, and (4) shift shock reduction function) will be described below.
[0026]
(1) First, motor running is possible.
The dog clutch 33 is set to the first switching position, the one-way clutch 19 is operated, the planetary gear 18 is fixed, and the driving force of the motor generator 12 is transmitted to the vehicle drive shaft 13 via the gear train 26.
In this case, the gear ratio of the gear train 26 is R ₂₆ If the ratio of the number of teeth of the sun gear of the planetary gear 18 to the number of teeth of the ring gear is K,
The relationship between the rotational speed and torque of each element (ring gear, sun gear, carrier) of the planetary gear is
N _Career = (1-K) × N _Sun + K × N _ring . . . (1)
T _Career = T _Sun / (1-K) = T _ring / K. . . (2)
Therefore, the torque T of the motor generator 12 _MG12 And the torque T to the vehicle drive shaft 13 _out The relationship with
T _out = ｛(K × R ₂₆ ) / (1-K)｝ · T _MG12 . . . (3)
It becomes. Since the condition for establishing the planetary gear 18 is about K <0.7, the denominator of the equation (3) is 1 or less, and R ₂₆ This results in a larger gear ratio.
[0027]
In other motor generator driving modes, when the dog clutch 33 is set to the first switching position, the clutch 16 is released, and the gear 25 of the automatic MT 17 is selected, the driving force of the motor generator 12 is doubled with a very large gear ratio. It is possible to communicate.
Here, the rotation speed N of the motor generator 12 _MG12 And torque T _MG12 And the input rotation speed N to the vehicle drive shaft 13 _out And torque T _out Is determined by setting the gear ratio of the shift stage 25 to R ₂₅ , The gear ratio of the gear train 26 is R ₂₆ If the ratio of the number of teeth of the sun gear of the planetary gear 18 to the number of teeth of the ring gear is K,
N _MG12 =-｛(R ₂₅ + K × R ₂₆ ) / (1-K)｝ · N _out . . . (4)
T _out = ｛(R ₂₅ + K × R ₂₆ ) / (1-K)｝ · T _MG12 . . . (5)
It becomes.
Although a gear other than the gear 25 can be selected, the transmission efficiency is not very good because of a power circulation state peculiar to the planetary gear.
[0028]
In the case of a general planetary gear having one input and two outputs, there are a power circulation state in which one output flows backward from one output and a power split state in which the input is branched into two and synthesized. In the case of the power circulation state, a mechanical loss is added to the flowing power, so that the larger the circulation amount, the lower the transmission efficiency. Therefore, if used for a long time, the energy is not negligible. On the other hand, in the power split state, only the output is combined, so that the gear loss is added only once.
In the case of the configuration of this study, when the engine 11 is a carrier input and the sun gear, carrier and ring gear are all rotating in the same direction, or when the motor generator 12 is a sun gear input and any of the sun gear, carrier and ring gear is used. When one of them is rotating in the opposite direction, a power split state is established.
[0029]
In the second switching position where the dog clutch 33 is connected to the gear train 27, there is a motor traveling mode in which the driving force of the motor generator 12 is transmitted to the vehicle drive shaft 13 via the gear train 27. In this case, the gear ratio up to the vehicle drive shaft 13 is reduced, so that the motor generator 12 can travel up to a high vehicle speed.
[0030]
(2) Second, power generation and assist are free.
Consider a case where the dog clutch 33 is set to the first switching position and the motor generator 12 generates and assists the power via the planetary gear 18.
The gear ratio selected from among the gear positions 21, 22, 23, 24 and the directly connected state of the automatic MT 17 is represented by R _n , The rotational speed N of the engine 11 _ENG11 And torque T _ENG11 , The relationship between the rotational speed and the torque is
N _MG12 = ｛(R _n −K × R ₂₆ ) / (1-K)｝ · N _out . . . (6)
N _ENG11 = R _n × N _out . . . (7)
T _out = R _n × T _ENG11 + ｛(K × R ₂₆ -R _n ) / (1-K)｝ · T _MG12 . . . (8)
It becomes.
At this time, since the planetary gear 18 is in the power split state, power generation and assist can be performed efficiently.
[0031]
In addition, even at the second switching position where the dog clutch 33 is connected to the gear train 27, power generation and assist can be performed via the gear train 27. When the vehicle speed is high, the number of revolutions of the motor generator 12 is also high and the motor generator 12 is in a high efficiency region, so that power generation and assist can be performed efficiently.
[0032]
(3) Third, regenerative braking is possible.
When the dog clutch 33 is set to the first switching position and the motor generator 12 regenerates via the planetary gear 18, the braking force input from the carrier is in a power circulation state peculiar to the planetary gear circulating via the ring gear. Although regenerative braking is possible, the transmission efficiency is not very good.
Therefore, at the time of high-speed running where large regenerative energy can be expected, the dog clutch 33 is set to the second switching position where it is connected to the gear train 27, and the motor generator 12 and the vehicle drive shaft 13 are directly connected to improve the transmission efficiency.
When the vehicle speed is high, the number of revolutions of the motor generator 12 also increases, so that regeneration of the motor generator 12 in a high efficiency region is possible.
[0033]
(4) Fourth, it is possible to reduce shift shock.
The shift shock reduction control of the present system includes two main types. Between low-speed gears with a large shift step, the planetary gears 18 are used to control the motor generator 12 to perform torque shock control by torque bypass control to bypass the torque of the engine 11, and between high-speed gears with a small shift step, the motor generator 12 is controlled. The shift shock reduction control is performed by the direct assist control. By changing the shift shock reduction control according to the selected shift speed and vehicle speed, the shift performance with less discomfort to the driver can be realized by the motor generator 12 having a small output. Hereinafter, a shift control example 1, a shift control example 2, and a shift control example 3 will be described.
[0034]
[Shift control example 1]
FIG. 3 is a flowchart illustrating a shift control example 1 (a case where a shift is made from the shift stage 21 to the shift stage 22) when the maximum output of the motor generator 12 is sufficiently larger than the current engine output. explain.
[0035]
In response to the shift start command in step 201, the torque of the motor generator 12 is increased in step 202. In step 203, the torque of the motor generator 12 is controlled so that the input torque of the dog clutch 32 becomes zero.
The target torque of the motor generator 12 is
tT _MG12 = (1-K) × T _ENG11 . . . (9)
It is added in consideration of inertia.
At this time, the torque of the engine 11 is input to the carrier of the planetary gear 18, transmitted to the vehicle drive shaft 13 via the ring gear via the ring gear 26, and thus the vehicle driving force T _out Is
T _out = K × R ₂₆ × T _ENG11 . . . (10)
It is added in consideration of inertia.
Vehicle driving force T _out Becomes (Equation 10) (the torque of the motor generator 12 reaches the target torque), the torque of the engine 11 input to the dog clutch 32 becomes approximately zero, so the process proceeds to step 204 to release the dog clutch 32. (First torque bypass control means).
[0036]
After the dog clutch 32 is released, the routine proceeds to step 205, where the rotation speed of the motor generator 12 is controlled. Since the dog clutch cannot be engaged unless the rotation speeds match, the rotation speed of the engine 11 is changed so that the rotation speed of the shift stage 22 and the rotation speed of the dog clutch 31 match (second torque bypass control means). At this time, the variation of the driving force can be reduced by shifting the operating point of the engine 11 by the motor generator 12 instead of controlling the engine 11.
The target value of the motor generator 12 at this time is
tN _MG12 = ｛(R ₂₂ −K × R ₂₆ ) / (1-K)｝ · N _out . . . (11)
It is. When the rotational speed of the gear 22 matches the rotational speed of the dog clutch 31 as in step 206, the dog clutch 31 is engaged with the gear 22 in step 207.
[0037]
Thereafter, when the torque of the motor generator 12 is reduced in step 208, the torque of the engine 11 is gradually transmitted to the vehicle drive shaft 13 via the shift speed 22 (third torque bypass control means). When the torque of the motor generator 12 becomes zero, the shift in step 209 ends.
[0038]
This control method is a form in which the torque of the engine 11 is branched and transmitted to the planetary gears 18, and is therefore referred to as torque bypass control.
[0039]
[Shift control example 2]
FIG. 4 is a flowchart showing a second example of the shift control when the maximum output of the motor generator 12 is relatively smaller than the current engine output (a case where the gear is shifted from the gear 21 to the gear 22). explain.
[0040]
In response to the shift start command in step 211, the torque of the motor generator 12 is increased in step 212, and the torque of the engine 11 is decreased. By reducing the torque of the engine 11, even a motor generator with a small torque can maintain the torque balance of the planetary gears, and the torque bypass control is established.
[0041]
In step 213, the torque of motor generator 12 and engine 11 is controlled so that the input torque of dog clutch 32 becomes zero. When the input torque of the dog clutch 32 is about zero, the routine proceeds to step 214, where the dog clutch 32 is released.
[0042]
After releasing the dog clutch 32, the process proceeds to step 215 to control the rotation speed of the motor generator 12. Since the dog clutch cannot be engaged unless the rotation speeds match, the rotation speed of the engine 11 is changed so that the rotation speed of the gear stage 22 and the rotation speed of the dog clutch 31 match. At this time, by cooperatively controlling the engine 11 and the motor generator 12, the speed can be changed without interrupting the driving force.
When the rotational speed of the gear 22 matches the rotational speed of the dog clutch 31 as in step 216, the dog clutch 31 is engaged with the gear 22 in step 217.
[0043]
Thereafter, when the torque of the engine 11 is increased and the torque of the motor generator 12 is decreased in step 218, the torque of the engine 11 is gradually transmitted to the vehicle drive shaft 13 via the shift speed 22. When the torque of the motor generator 12 becomes zero, the shift in step 219 ends.
[0044]
[Shift control example 3]
FIG. 5 is a flowchart showing a shift control example 3 (shifting from the direct connection state to the shift step 24) executed in a shift between high-speed gears with a small shift step. Each step will be described below.
[0045]
In the configuration of the present invention, since the planetary gear 18 is designed mainly to reduce the shift shock between the low-speed gears having a large shift step, in order to reduce the shift shock between the high-speed gears, the output of the motor generator 12 must be very low. Need to be bigger. Therefore, the dog clutch 33 is set to the second switching position to be engaged with the gear train 27, and the motor generator 12 is directly connected to the vehicle drive shaft 13 to perform shift control for assisting (shift torque assist control means).
[0046]
In response to the shift start command in step 221, the torque of the engine 11 is reduced in step 222, and the dog clutch 30 is released in step 223. Then, in step 224, the torque of motor generator 12 is increased. By the motor generator assist in step 224, the shock at the time of shifting is reduced. Although the output of the motor generator 12 is smaller than that of the engine 11, the assist force is small. However, between high-speed gears with a small shift step, the shift shock can be suppressed to such an extent that the driver does not feel uncomfortable.
[0047]
At step 225, the rotation speed of the engine 11 is controlled. At step 226, it is determined whether or not the rotation speed of the engine 11 matches the rotation speed of the shift stage 24. If the rotational speeds match, the process proceeds to step 227, in which the torque of the motor generator 12 is reduced. In step 228, the dog clutch 30 is engaged with the shift speed 24. At this time, there is a slight difference between the rotation speed of the engine 11 and the rotation speed of the shift stage 24, and this difference causes a shift shock. Therefore, when the dog clutch 30 is engaged, the engagement pressure of the clutch 16 is reduced, and the motor generator The shock is absorbed by controlling the speed of the motor 12 or the like. After the dog clutch 30 is engaged, the torque of the engine 11 is increased in step 229, and the shift operation ends in step 230.
[0048]
FIG. 6 is a diagram showing the relationship between the rotation speed of the motor generator 12 and the vehicle speed of the hybrid vehicle according to the first embodiment of the present invention, and the operating point of the motor generator 12 is in the high efficiency region of FIG. The dog clutch 33 is switched according to the selected shift speed and vehicle speed.
[0049]
Next, effects will be described.
In the hybrid vehicle drive device of the first embodiment, the following effects can be obtained.
[0050]
A first shaft connected to the output shaft of the engine 11, a second shaft connected to the vehicle drive shaft 13, and a gear train 27 for transmitting the rotational torque of the motor generator 12 to the second shaft at a constant gear ratio. And a planetary gear 18 having a sun gear, a carrier, and a ring gear, wherein the carrier is connected to the first shaft, and the ring gear is connected to the second shaft, and the gear train 27 connects the motor generator 12 to the sun gear. A dog clutch 33 that can be switched between a first switching position for turning off the rotational torque transmission state and a second switching position for disconnecting the motor generator 12 from the sun gear and putting the gear train 27 into a state where the rotational torque can be transmitted; The rotational torque of motor generator 12 can be used for controlling the vehicle driving force in two different forms.
[0051]
Note that such a driving device includes a plurality of gears (gears 21, 22, 23, 24, 25 and a direct connection) for transmitting the rotation torque of the first shaft to the second shaft at a unique gear ratio. It can be combined with the automatic MT 17 including the dog clutches 30, 31, and 32 that make only one of the plurality of gears transmit the rotational torque.
[0052]
As a usage form of the rotation torque of the motor generator 12, when the dog clutch 33 is at the first switching position, the rotation torque of the motor generator 12 is controlled to reduce the rotation torque of the first shaft (that is, the rotation torque of the engine 11). Torque bypass control for transmitting to the second shaft via the planetary gear 18 and torque assist control for transmitting the rotational torque of the motor generator 12 to the second shaft via the gear train 27 when the dog clutch 33 is at the second switching position. And can be implemented. According to the form of the torque bypass control, it is possible to transmit a relatively large rotational torque to the vehicle drive shaft 13 via the planetary gears 18 while keeping the capacity of the motor generator 12 small, and according to the form of the torque assist control. In addition, it becomes easy to transmit the rotation torque of the motor generator 12 to the vehicle drive shaft 13 during high-speed driving of the vehicle in which the rotation speed of the vehicle drive shaft 13 is high.
[0053]
At the time of gear shifting in which the gear of the automatic MT17 is changed, transmission of rotational torque via the automatic MT17 is temporarily interrupted. By performing either one of the torque bypass control and the torque assist control during this gearshift, In addition, it is possible to suppress the shock generated by the interruption of the torque.
[0054]
At this time, by selecting either the torque bypass control or the torque assist control depending on whether the change is between low-speed gears or high-speed gears, the characteristic of the torque step generated at the time of shifting is adapted. Shock suppression control can be performed.
[0055]
Specifically, the torque bypass control is selected when shifting between low-speed gears, and the torque assist control is selected when shifting between high-speed gears. At the time of shifting between low-speed gears, a relatively large rotational torque is required, so torque bypass control is advantageous. At the time of shifting between high-speed gears, the rotational speed of the vehicle drive shaft 13 is high, so that torque assist control is advantageous. . By appropriately selecting the shock suppression control, both the shift shock suppression between the low-speed gears and the shift shock suppression between the high-speed gears can be favorably performed by the motor generator 12 having a small capacity.
[0056]
The switching of the dog clutches 31 and 32 can be easily performed by starting the torque bypass control when the original gear is transmitting the rotational torque and ending it after the original gear is transmitting the rotational torque. It is possible to do it.
[0057]
Further, since the torque assist control is performed when neither the change source gear nor the change destination gear transmits the rotational torque, the rotational torque of the engine 11 and the rotational torque of the motor generator 12 via the automatic MT 17 are simultaneously adjusted. It is not transmitted to the vehicle drive shaft 13, and it is possible to prevent the vehicle driving force from temporarily increasing during shifting.
[0058]
The dog clutch 33 connects the motor generator 12 to the sun gear, switches the gear train 27 to the rotational torque transmission interrupted state, and can switch to the third switching position where the three rotating elements of the planetary gear 18 are prohibited from rotating relative to each other. It is. When the dog clutch 33 is at the third switching position, both the rotational torque of the engine 11 and the rotational torque of the motor generator 12 can be transmitted to the vehicle drive shaft 13 via the gear train 26.
[0059]
Since the carrier is connected to the first shaft among the sun gear, the carrier, and the ring gear constituting the planetary gear, the power circulation state unique to the planetary gear does not occur when the engine 11 generates the rotational torque. .
[0060]
A first shaft connected to the output shaft of the engine 11, a second shaft connected to the vehicle drive shaft 13, and a gear (transmission) for transmitting the rotational torque of the first shaft to the second shaft at a fixed gear ratio. Stage 21), a sun gear, a carrier, and a ring gear, the carrier is connected to the first shaft, the ring gear is connected to the second shaft via a gear train 26, and the sun gear is connected to the motor generator 12. And the planetary gear 18 which transmits the rotational torque of the engine 11 to the vehicle drive shaft 13 via a gear, the planetary gear 18, or the rotational torque via the gear and the planetary gear 18. It is possible to transmit the rotation torque separately.
[0061]
Further, the dog clutches 30, 31, 32 are further provided which are switchable between an engagement position where the gears can transmit the rotational torque and a neutral position where the gears can transmit the rotational torque. , 32 are in the neutral position, it is possible for the planetary gear 18 to function as a continuously variable transmission.
[0062]
The automatic MT 17 according to the present embodiment includes six gears (gears 21, 22, 23, 24, 25 and a direct connection) having different gear ratios, and the dog clutches 30, 31, and 32 have one of the six gears. It is possible to switch between six fastening positions in which only one of the gears can transmit the rotational torque and a neutral position in which all the gears are in the rotational torque transmission interrupted state.
[0063]
When the engagement positions of the dog clutches 31 and 32 are changed, torque bypass control for controlling the rotation torque of the motor generator 12 and transmitting the rotation torque of the first shaft to the second shaft via the planetary gear 18 is performed. Shock generated by torque interruption can be suppressed. According to the form of the torque bypass control, it is possible to transmit a relatively large rotational torque to the vehicle drive shaft 13 via the planetary gear 18 while keeping the capacity of the motor generator 12 small.
FIG. 7 is a schematic diagram showing a change in vehicle acceleration according to a shift control example 2 (FIG. 4) in which the torque bypass control is performed. Shock caused by a change in acceleration during shifting can be reduced as compared with the existing automatic MT.
[0064]
The torque bypass control is started when the dog clutches 31 and 32 are at the original engagement positions and is ended after the dog clutches 31 and 32 are at the new engagement positions, thereby switching the dog clutches 31 and 32. Can be easily performed
[0065]
When the dog clutches 31 and 32 are at the original engagement positions, the first torque bypass control for increasing the rotational torque of the motor generator 12 to increase the amount of rotational torque transmitted via the planetary gears 18 is performed.
[0066]
The position of the dog clutches 31, 32 is switched to the neutral position when the rotation torque transmission amount via the gear of the original gear is reduced to substantially zero by the execution of the first torque bypass control, so that the switching of the dog clutches 31, 32 is facilitated. Can be done.
[0067]
Further, when the dog clutches 31 and 32 are in the neutral position, the rotation speed of the motor generator 12 is controlled, and the second torque bypass control that brings the rotation speeds of the dog clutches 31 and 32 closer to the rotation speed of the gear to be changed is performed. .
[0068]
When the rotation speed of the gear to be changed and the rotation speed of the dog clutches 31 and 32 substantially coincide with each other by performing the second torque bypass control, the positions of the dog clutches 31 and 32 are switched to the engagement positions of the change destination. Switching of the clutches 31 and 32 can be easily performed.
[0069]
Further, when the dog clutches 31 and 32 are at the changed engagement positions, a third torque bypass control for reducing the rotational torque of the motor generator 12 to reduce the amount of rotational torque transmitted via the planetary gear 18 is performed.
[0070]
(Second embodiment)
The second embodiment is an example in which a system suitable for an FF vehicle (front engine / front drive vehicle) equipped with a horizontal engine is provided.
[0071]
That is, as shown in FIG. 8, a configuration from the planetary gears 318 to the motor generator 312 is a parallel three-axis configuration in which the shaft from the engine 311 is arranged in parallel. 8, 311 is an engine, 312 is a motor generator, 313 is a vehicle drive shaft, 314 is a differential gear, 315 is a drive wheel, 316 is a clutch, 317 is an automatic MT, 318 is a planetary gear, 319 is a one-way clutch, 321 322, 323, 324, and 325 are forward gears, 326 is a reverse gear, 327 and 328 are gears, and 330, 331, 332, and 333 are dog clutches. Note that the description of each configuration is the same as that of the first embodiment, and will not be repeated.
[0072]
Next, the operation will be described.
The planetary gear 318 has a carrier shaft connected to the engine 311, a sun gear shaft connected to the motor generator 312, and a ring gear shaft connected to the vehicle drive shaft 313 from the gear 327 via the shift stage 322, so that the first embodiment is performed. Torque bypass control is possible as in the example.
The motor generator 312 can be directly connected to the vehicle drive shaft 313 from the gear 328 via the gear 323, and the gear shift shock can be directly reduced by the motor generator 312. The switching can be performed by the dog clutch 333. In this embodiment, the gear 328 and the shift speed 323 constitute a rotating torque transmission mechanism for a motor generator.
[0073]
Next, effects will be described.
In the drive device of the hybrid vehicle according to the second embodiment, since a parallel three-axis configuration is adopted, a system can be configured without extending the axial direction of the automatic MT 317 as a base, and a system suitable for an FF vehicle can be provided. .
[0074]
(Third embodiment)
The third embodiment is an example in which a system suitable for an FF vehicle equipped with a horizontal engine and a system in which a more efficient area can be selected according to the vehicle state is provided.
[0075]
That is, as shown in FIG. 9, a parallel three-axis configuration in which the configuration from the gear 69 to the motor generator 52 is arranged in parallel with the axis from the engine 51 is adopted. 9, 51 is an engine, 52 is a motor generator, 53 is a vehicle drive shaft, 54 is a differential gear, 55 is a drive wheel, 56 is a clutch, 57 is an automatic MT, 58 is a planetary gear, 59 is a one-way clutch, 61 and 62, 63, 64 and 65 are forward gears, 66 is a reverse gear, 66, 67, 68 and 69 are gears, and 70, 71, 72, 73 and 74 are dog clutches. Note that the description of each configuration is the same as that of the first embodiment, and will not be repeated.
[0076]
Next, the operation will be described.
When the dog clutch 73 is in the neutral state and the dog clutch 74 is engaged with the sun gear shaft of the planetary gear 58, the planet gear 58 has the carrier shaft connected to the engine 51, the sun gear shaft connected to the motor generator 52, Since the ring gear shaft is connected to the vehicle drive shaft 53 from the gear 67 via the gear stage 62, torque bypass control is possible.
When the dog clutch 73 is in the neutral state and the dog clutch 74 is engaged with the gear 69, the motor generator 52 can be directly connected to the output shaft of the engine 51 of the automatic MT 57. The rotation speed is twice as high as the gear ratio.
Since the shift stages 61, 62, 63, 64, and 65 are provided for the vehicle drive shaft 53, the range of selection of the operation region can be widened according to the driving situation.
When the dog clutch 73 and the dog clutch 74 are in the neutral state, the motor generator 52 is in a state of being disconnected from the automatic MT 57, so that the accompanying loss can be reduced.
When the dog clutch 73 is engaged with the gear 67 and the dog clutch 74 is in the neutral state or in the engaged state with the planetary gear 58, the planetary gear 58 is in one shift speed, and the torque of the engine 51 is transmitted from the gear 67 to the planetary gear 62 via the shift speed 62. Can be transmitted to the vehicle drive shaft 53.
When the dog clutch 73 is engaged with the gear 68 and the dog clutch 74 is in the neutral state, the motor generator 52 is directly connected to the vehicle drive shaft 53 from the gear 68 via the shift speed 63, so that regeneration and assist can be efficiently performed. It becomes. The shift shock reduction control shown in FIG. 5 is also possible.
[0077]
Next, effects will be described.
In the drive device for a hybrid vehicle according to the third embodiment, since the above-described configuration is employed, the system can be configured without extending the axial direction of the automatic MT 57 serving as a base. Since there are a number of connection methods 52, a system can be provided in which a more efficient area can be selected according to the state of the vehicle.
[0078]
As mentioned above, the drive device of the hybrid vehicle according to the present invention has been described based on the first to third embodiments. However, the specific configuration is not limited to these embodiments. Changes and additions to the design are permitted without departing from the gist of the claimed invention.
[Brief description of the drawings]
FIG. 1 is an overall system diagram showing a drive device for a hybrid vehicle according to a first embodiment.
FIG. 2 is an explanatory diagram of an operation of a dog clutch used in the first embodiment device.
FIG. 3 is a flowchart showing a shift control example 1 when the maximum output of the motor generator in the device of the first embodiment is sufficiently large.
FIG. 4 is a flowchart illustrating a second example of shift control when the motor generator in the first embodiment is relatively small.
FIG. 5 is a flowchart illustrating a third example of shift control executed in shifting between high-speed gears with a small shift step in the device of the first embodiment.
FIG. 6 is a diagram showing a relationship between the rotation speed of a motor generator and a vehicle speed of a hybrid vehicle equipped with the first embodiment device.
FIG. 7 is a schematic diagram showing changes in vehicle acceleration due to shift control in a hybrid vehicle equipped with the first embodiment device.
FIG. 8 is an overall system diagram showing a drive device for a hybrid vehicle according to a second embodiment.
FIG. 9 is an overall system diagram showing a drive device for a hybrid vehicle according to a third embodiment.
[Explanation of symbols]
11 Engine
12 Motor generator
13 Vehicle drive shaft
14 Differential gear
15 Drive wheels
16 clutch
17 Automatic MT
18 planetary gear (differential mechanism)
19 One-way clutch
21, 22, 23, 24 forward gear
25 Reverse gear
26, 27 gear train
30, 31, 32 Dog clutch (fastening device)
33 dog clutch (switching mechanism)

Claims (20)

A first shaft connected to the output shaft of the engine;
A second shaft connected to the vehicle drive shaft;
A motor generator rotation torque transmission mechanism for transmitting the rotation torque of the motor generator to the second shaft at a constant speed ratio;
A differential mechanism having three rotating elements, a first rotating element connected to the first axis, and a second rotating element connected to the second axis;
Connecting the motor generator to the third rotating element of the differential mechanism and disconnecting the motor generator from the third rotating element; A switching mechanism capable of switching to a second switching position for bringing the motor generator rotation torque transmission mechanism into a state in which rotation torque can be transmitted;
A drive device for a hybrid vehicle comprising: A plurality of rotation torque transmission mechanisms for transmitting the rotation torque of the first shaft to the second shaft at respective unique speed ratios;
A fastening device for setting only one of the plurality of rotation torque transmission mechanisms to a state capable of transmitting rotation torque;
The drive device for a hybrid vehicle according to claim 1, further comprising: When the switching mechanism is in the first switching position, a torque bypass control for controlling the rotation torque of the motor generator to transmit the rotation torque of the first shaft to the second shaft via the differential mechanism is performed. And
When the switching mechanism is at the second switching position, torque assist control for transmitting the rotation torque of the motor generator to the second shaft via the motor generator rotation torque transmission mechanism is performed. Item 3. A drive device for a hybrid vehicle according to item 2. 4. The hybrid vehicle drive device according to claim 3, wherein one of the torque bypass control and the torque assist control is performed when changing a rotation torque transmission mechanism that changes a rotation torque transmission enabled state. . The method according to claim 1, wherein at least one of the torque bypass control and the torque assist control is selected in accordance with at least one of a source rotational torque transmission mechanism, a destination rotational torque transmission mechanism, and a vehicle speed at the time of the change. Item 5. A drive device for a hybrid vehicle according to item 4. The torque bypass control is selected when the source or destination rotary torque transmission mechanism is a low-speed rotary torque transmission mechanism, and when the source or destination rotary torque transmission mechanism is a high-speed rotary torque transmission mechanism. The drive device for a hybrid vehicle according to claim 5, wherein the torque assist control is selected. The torque bypass control is started when the rotation torque transmission mechanism of the change source is transmitting the rotation torque, and is ended after the rotation torque transmission mechanism of the change destination starts to transmit the rotation torque. Item 7. A drive device for a hybrid vehicle according to any one of Items 4 to 6. The hybrid vehicle according to any one of claims 4 to 7, wherein the torque assist control is performed when both the change source and change destination torque transmission mechanisms are not transmitting the torque. Drive. The switching means connects the motor generator to a third rotating element of the differential mechanism, sets the rotating torque transmission mechanism for the motor generator to a rotational torque transmission interrupted state, and controls the three rotating elements of the differential mechanism to rotate relative to each other. The drive device for a hybrid vehicle according to any one of claims 1 to 8, wherein the drive device can be switched to a third switching position in which the switching is prohibited. The said differential mechanism is a planetary gear provided with a sun gear, a carrier, and a ring gear as three rotating elements, The said carrier is connected to the said 1st axis | shaft, The Claim 1 characterized by the above-mentioned. A drive device for a hybrid vehicle according to any one of the preceding claims. A first shaft connected to the output shaft of the engine;
A second shaft connected to the vehicle drive shaft;
A rotation torque transmission mechanism for transmitting the rotation torque of the first shaft to the second shaft at a constant speed ratio;
A differential mechanism having three rotating elements, a first rotating element connected to the first shaft, a second rotating element connected to the second shaft, and a third rotating element connected to the motor generator; ,
A drive device for a hybrid vehicle comprising: 12. The apparatus according to claim 11, further comprising a fastening device that can be switched between a fastening position that sets the rotation torque transmission mechanism to a state where the rotation torque can be transmitted and a neutral position that sets the rotation torque transmission mechanism to a state where the rotation torque transmission is interrupted. A drive device for a hybrid vehicle according to claim 1. Equipped with multiple rotational torque transmission mechanisms with different speed ratios,
The fastening means is switchable between a plurality of fastening positions for setting only one of the plurality of rotating torque transmitting mechanisms to a state capable of transmitting the rotating torque, and a neutral position for setting all the rotating torque transmitting mechanisms to a cutoff state for the rotating torque transmission. The drive device for a hybrid vehicle according to claim 12, wherein: When changing the fastening position of the fastening device, performing torque bypass control for controlling the rotation torque of the motor generator and transmitting the rotation torque of the first shaft to the second shaft via the differential mechanism. The drive device for a hybrid vehicle according to claim 13, wherein: 15. The hybrid vehicle according to claim 14, wherein the torque bypass control is started when the fastening device is at the original fastening position, and is terminated after the fastening device is at the new fastening position. Drive. When the fastening device is at the original fastening position, a first torque bypass control for increasing a rotation torque of the motor generator to increase a rotation torque transmission amount via the differential mechanism is performed. Item 16. The drive device for a hybrid vehicle according to item 14 or 15. 17. The device according to claim 16, wherein the position of the fastening device is switched to a neutral position when the rotation torque transmission amount via the rotation torque transmission mechanism of the change source is reduced to substantially zero by performing the first torque bypass control. For hybrid vehicles. When the fastening device is at the neutral position, the rotation speed of the motor generator is controlled, and a second torque bypass control that brings the rotation speed of the fastening device closer to the rotation speed of the rotation torque transmission mechanism to be changed is performed. The drive device for a hybrid vehicle according to any one of claims 14 to 17, wherein When the rotation speed of the rotation torque transmission mechanism to be changed substantially matches the rotation speed of the fastening device by performing the second torque bypass control, the position of the fastening device is switched to the fastening position to be changed. The drive device for a hybrid vehicle according to claim 18. When the fastening device is at the changed fastening position, a third torque bypass control for reducing a rotation torque of the motor generator to reduce an amount of rotation torque transmitted through the differential mechanism is performed. Item 20. The drive device for a hybrid vehicle according to any one of Items 14 to 19.

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