JP2003130202A - Method for operating hybrid vehicle driving structure with transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To renew a switching mode of a gear shift stage so that a characteristic of a hybrid vehicle driving structure is made the most of, when incorporating a transmission in mid-way of a wheel drive shaft to obtain a required speed to axle torque characteristic by keeping fuel economy of an internal combustion engine in an excellent state without increasing a second motor-generator in scale, in the hybrid vehicle driving structure connecting an output shaft of the internal combustion engine to a first motor-generator and the wheel drive shaft via a power distribution mechanism and connecting the second motor- generator to the wheel drive shaft. SOLUTION: A region corresponding to each gear shift stage is partitioned not according to a speed but according to the magnitude of axle torque from the viewpoint of a coordinate system of the speed to axle torque showing axle torque sharing by the internal combustion engine and the second motor- generator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a drive structure of a hybrid vehicle in which wheels are driven by a combination of an internal combustion engine and an electric motor.

[0002]

2. Description of the Related Art In recent years, hybrid vehicles in which wheels are driven by a combination of an internal combustion engine and an electric motor have been in the limelight in recognition of the increasing importance of environmental protection and fuel resource saving. . When driving the wheels of an automobile, which require various combinations of rotational speed and driving torque, by an internal combustion engine and an electric motor, various driving modes may be possible. Originally, it was driven exclusively by an internal combustion engine, and hybrid vehicles in the field of automobiles started by replacing some conventional internal combustion engine-only drive with electric drive as far as the situation allows. Therefore, it is considered natural that even a hybrid vehicle can be driven only by the internal combustion engine. JP-A-11-
In 198669, a first motor / generator is connected in series to a crankshaft of an internal combustion engine to form a power shaft driven by either or both of the internal combustion engine and the electric motor. A hybrid vehicle drive structure is shown in which an output shaft of a generator is connected to and combined with a ring gear and a sun gear of a planetary gear mechanism, and a carrier of the planetary gear mechanism is used as an output shaft and a transmission is connected to the carrier. . According to such a hybrid vehicle drive structure, even if only the internal combustion engine is used as a prime mover, the shift function of the transmission is obtained, and it is possible to cope with various operating modes required for a vehicle, like a conventional internal combustion engine vehicle. This seems to be one of the typical examples reflecting the origin of the hybrid vehicle as described above.

On the other hand, however, on the occasion of combining an internal combustion engine and an electric motor as a prime mover of an automobile, the internal combustion engine is caused by the difference between the rotational speed required for the wheels and the driving torque and the rotational speed obtained from the internal combustion engine versus the driving torque. By the same person as the applicant of the present application, it is possible to differentially absorb the difference in rotation speed between the output shaft and the axle by the electric motor and eliminate the transmission that has been conventionally required between the internal combustion engine output shaft and the axle. was suggested. FIG. 1 attached herewith is a schematic view showing a drive structure of such a hybrid vehicle.

In FIG. 1, reference numeral 1 denotes an internal combustion engine, which is mounted on a vehicle body (not shown). Reference numeral 2 is its output shaft (crank shaft). 3 is a planetary gear device, 4 is its sun gear, 5 is a ring gear, 6 is a planetary pinion, and 7 is a carrier. The crankshaft 2 is connected to the carrier 7. 8 is the first motor generator (MG
1), which has the coil 9 and the rotor 10, and the rotor 10
Is connected to the sun gear 4. The coil 9 is supported by the vehicle body. One end of a propeller shaft 11 is connected to the ring gear 5. Thus, the planetary gear device 3 constitutes a power distribution mechanism that distributes the output of the internal combustion engine, which appears on the output shaft 2 of the internal combustion engine, to the first motor generator 3 and the propeller shaft 11 that serves as a wheel drive shaft. A second motor generator (MG2) 12 is connected in the middle of the propeller shaft 11.
The second motor generator 12 has a coil 13 and a rotor 14, and the coil 13 is supported by the vehicle body. The connection of the rotor 14 to the propeller shaft 11 may have any structure, but in the illustrated example, the structure is such that the gear 15 provided on the propeller shaft 11 meshes with the rotating gear 16 supported by the rotor 14. ing. The other end of the propeller shaft 11 is connected to a pair of axles 18 via a differential device 17. Wheels 19 are attached to each of the axles 18.

In the illustrated drive structure, the rotation of the crankshaft 2 and the rotation of the carrier 7 are the same, and this rotation speed is now represented by Nc. Further, the rotation of the first motor generator 8 and the rotation of the sun gear 4 are the same, and this rotation speed is now represented by Ns. On the other hand, the rotation of the ring gear 5, the rotation of the second motor generator 12, and the rotation of the wheels 19 correspond to each other and finally correspond to the vehicle speed, but the respective rotation speeds are those of the gears 15 and 16. It depends on the ratio of the number of teeth between them, the speed reduction ratio in the differential device 17, and the tire diameter. However, here, for the sake of convenience, the rotational speed of these portions is represented by the rotational speed of the ring gear 5, and is represented by Nr. Then, between the internal combustion engine and the two motor generators MG1, MG2 in the hybrid vehicle drive structure in which the internal combustion engine and the two motor generators are combined by a planetary gear device as shown in the drawing, between the rotational speeds Nc, Ns, Nr. The relationship is expressed by the diagram shown in FIG. 2 based on the principle of the planetary gear device. In the figure, ρ is the number of teeth of the sun gear with respect to the number of teeth of the ring gear (ρ <1). Since Nc is determined by the engine speed and Nr is determined by the vehicle speed, Ns is determined as Ns = (1 + 1 / ρ) Nc− (1 / ρ) Nr depending on the engine speed and the vehicle speed.

On the other hand, if the torques of the carrier, sun gear, and ring gear are Tc, Ts, and Tr, these are Ts: Tc: Tr = ρ / (1 + ρ): 1: 1 / (1+
When a ratio of ρ) balances each other, and thus any of these three elements produces or absorbs torque, torque is exchanged between them until the above balance is established.

In the hybrid vehicle having the above-described drive structure, the internal combustion engines, MG1 and MG2 are operated by a vehicle operation control device (not shown) from the driver and operation of the vehicle. It is controlled based on the state and.
That is, the vehicle operation control device includes a microcomputer, calculates the target vehicle speed and the target wheel drive torque based on the operation command of the driver and the operation state of the vehicle detected by various sensors, and charges the power storage device. Based on the state, calculate the current output allowed for the power storage device or the amount of power generation required for charging the power storage device, and based on these calculation results, what operating state should the internal combustion engine operate in, including stoppage, In addition, calculate what kind of electric or electric power generation state MG1 and MG2 should be operated in,
The operation of the internal combustion engine, MG1 and MG2 is controlled based on the calculation result.

[0008]

As described above, the output shaft of the internal combustion engine is connected to the first motor / generator and the wheel drive shaft through the power distribution mechanism, and the second shaft is connected to the wheel drive shaft. According to the hybrid vehicle drive structure in which the motor generator is connected, as understood from FIG. 2, the respective values of the rotation speed Nc of the internal combustion engine output shaft and the rotation speed Nr corresponding to the vehicle speed, and the relative relationship between them are as follows. Since the change can be drastically changed by absorbing the change in the number of revolutions Ns of the first motor-generator, a transmission has not been required in the hybrid vehicle drive structure. That is, the relationship between Nc and Nr can be freely changed depending on the adjustment of the power distribution mechanism, and the engine is operated (Nc> 0) even when the vehicle is stopped (Nr = 0). Moving forward (Nr>
Even if it is 0), the engine can be stopped (Nc = 0), or the engine can be moved backward (Nr <0) regardless of whether the engine is running or stopped (Nc ≧ 0).

However, the number of revolutions of MG2 depends on the vehicle speed, and the degree of charge of the power storage device is irrelevant to the vehicle speed. Therefore, MG2 has a large limitation in operating as a generator for charging the power storage device. There is. Therefore, charging of the power storage device depends exclusively on MG1, and conversely, electric drive of the wheels depends exclusively on MG2. Therefore, in the hybrid vehicle drive structure as described above, which is not provided with a transmission, in order to secure the vehicle driving performance capable of obtaining a high wheel drive torque as necessary even in the low vehicle speed range, the quality MG2 Is inevitably larger.

If this is shown by the coordinate system of the vehicle speed versus the axle torque in which the magnitude of the required value of the axle torque is compared with the vehicle speed,
It is as shown in FIG. That is, now, the internal combustion engine of the vehicle should be operated with high fuel efficiency over a wide range of vehicle speeds, and the vehicle should have the performance shown by line A as the limit performance desired as the vehicle speed vs. axle torque performance. Then, since the vehicle speed versus axle torque performance of the internal combustion engine that obtains high fuel consumption becomes almost flat as in region B, the rest must be compensated exclusively with MG2, and the vehicle velocity versus axle torque performance covers region C. Must be something. Therefore, the MG2 must be large enough to generate high torque at a low rotation speed.

However, when examining FIG. 3, it is doubted that the depth of the region C is a little too deep as compared with the depth of the region B. From a different point of view, this is a problem of the relative balance between the sizes of the internal combustion engine and the three prime movers, that is, the first and second motor-generators, and particularly the size balance between the internal combustion engine and the second motor-generator. Is. In order to further improve the hybrid vehicle drive structure as described above in view of this point, the same person as the applicant of the present invention has disclosed in Japanese Patent Application No. 2001-323578 relating to another application that the output shaft of the internal combustion engine is In a hybrid vehicle drive structure in which a first motor generator and a wheel drive shaft are connected via a power distribution mechanism, and a second motor generator is connected to the wheel drive shaft, in the middle of the wheel drive shaft or A hybrid vehicle drive structure characterized in that a transmission is provided at least on one side of the connection of the second motor generator to the wheel drive shaft.

The hybrid vehicle drive structure with a transmission according to the above-mentioned another Japanese Patent Application No. 2001-323578 is the same as in a conventional internal combustion engine drive vehicle with a transmission even when a transmission is provided in the middle of a wheel drive shaft. In addition, in a low vehicle speed range, the transmission may be switched to a low speed stage having a large reduction ratio, and in a high vehicle speed range, the transmission may be switched to a high speed stage having a small reduction ratio.

Problem to be Solved by the Invention In the above Japanese Patent Application No. 2001-323578, the output shaft of the internal combustion engine is connected to the first motor generator and the wheel drive shaft via the power distribution mechanism, and the wheel drive shaft is The reason why the transmission is incorporated into the hybrid vehicle drive structure in which the second motor generator is connected is to reduce the required capacity of the second motor generator, especially when high axle torque is required. . However, in the operation of an automobile on a general flat land, a very high axle torque is not required even when the vehicle is started.

Therefore, the present invention is based on the above recognition.
An output shaft of an internal combustion engine is connected to a first motor generator and a wheel drive shaft via a power distribution mechanism, a second motor generator is connected to the wheel drive shaft, and a transmission is provided in the middle of the wheel drive shaft. It is an object of the present invention to provide a method for driving a hybrid vehicle drive structure provided with the above with special consideration given to transmission switching control.

[0015]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an output shaft of an internal combustion engine, which is connected to a first motor / generator and a wheel drive shaft through a power distribution mechanism to drive the wheel. A second motor / generator is connected to the shaft, and a method of operating a hybrid vehicle drive structure is provided in which a transmission is provided in the middle of the wheel drive shaft, the transmission is set to a predetermined high speed stage, and the internal combustion engine The present invention proposes a hybrid vehicle drive structure operating method characterized in that the vehicle is driven with high fuel consumption and the axle torque demand value can be met, and the vehicle is operated while maintaining the high speed stage regardless of changes in vehicle speed.

The term "motor generator" refers to means having both functions of an electric motor and a generator. In the present invention, however, the output shaft of the internal combustion engine goes through the power distribution mechanism to drive the first motor generator and the wheels. The present invention relates to a short-term vehicle drive performance of a hybrid vehicle drive structure in which a second motor / generator is connected to a shaft and the wheel drive shaft is connected, in other words, to an internal combustion engine drive in a hybrid drive of the vehicle. , Electric drive,
As far as the operation and effect of the present invention are concerned, both the first and second motor-generators are mere electric motors because they are not related to the long-term vehicle driving performance in which the mutual relationship of the self-charging action on the power storage device is involved. It's good. Certainly, as a vehicle drive device that actually works, as already mentioned, the second motor generator has to operate exclusively as an electric motor (but it can also operate as a generator),
Therefore, in order to construct a vehicle drive device that can operate for a long period of time, the first motor generator must have a power generation function, but this need is not related to the technical idea of the present invention. That is. Therefore, in the configuration of the present invention, the means described as a motor generator includes a motor having no power generation function as its equivalent.

Although the hybrid vehicle drive structure operating method as described above cannot meet the required axle torque value when the transmission is set to the high speed, the transmission can be set to the next lower speed after the high speed. For example, as long as it is possible to meet the required axle torque value, it may be added that the transmission is operated while being held at a gear next to the high speed regardless of changes in the vehicle speed.

In the hybrid vehicle drive structure operating method as described above, the axle torque demand value cannot be met in a state in which the transmission is set to the gear next to the high-speed stage, but the transmission is set to the lower gear next to the high-speed stage. As long as it is possible to meet the axle torque demand value by setting the gear next to the gear next to, the transmission is held at the gear next to the gear next to the high gear regardless of changes in the vehicle speed. Driving may be added.

Furthermore, in the hybrid vehicle drive structure operating method as described above, when the speed stage of the transmission is switched, the switching of the next speed stage may be prohibited until a predetermined time elapses.

Furthermore, in the hybrid vehicle drive structure operating method as described above, when it is necessary to change the shift speed in order to correspond to the required value of the axle torque, the shift speed is changed within a predetermined time instead of the change of the shift speed. It may be made to respond by changing the output of at least one of the first and second motor generators.

Furthermore, in the hybrid vehicle drive structure driving method as described above, the driving method is switched between the normal driving mode and the sports driving mode, and when the sports driving mode is switched, the transmission is changed to change the vehicle speed. Regardless, holding at the high speed stage may be released.

[0022]

The output shaft of the internal combustion engine is connected to the first motor generator and the wheel drive shaft via the power distribution mechanism,
In the hybrid vehicle drive structure in which the second motor generator is connected to the wheel drive shaft, each of the axle speed and the internal combustion engine speed due to the change in the vehicle speed and the change in the operating state of the internal combustion engine over the entire vehicle speed range, and between them Since the change in the relative relationship is absorbed by the adjustment of the first motor / generator rotation speed, even if a transmission is provided in the middle of the wheel drive shaft, when operating such a hybrid vehicle drive structure, As long as the transmission is set to a predetermined high speed and the internal combustion engine can be operated at high fuel efficiency to meet the axle torque required value, the high speed can be maintained and operated regardless of changes in the vehicle speed. When a vehicle does not require a large amount of axle torque, such as when driving a car on a level ground, even if a gearbox is installed, keep it at a predetermined high speed and keep it in the entire vehicle speed range. garden Without requiring the transmission switching control I, by operating an internal combustion engine at a high fuel efficiency as required,
It is possible to drive a hybrid vehicle without a shift shock or a shift delay.

Further, although it is impossible to meet the required axle torque value when the transmission is set to the high speed stage, as long as the transmission can be set to the next lower speed stage after the high speed stage, the required axle shaft torque value can be met. Despite the change in the vehicle speed, the vehicle is operated by holding the transmission at the lower gear next to the higher gear, and similarly, when the gear is set at the lower gear next to the high gear, the axle is set. Although it cannot respond to the torque request value, if the transmission is set to the gear next to the gear next to the high speed, the gear can be set to the high speed regardless of the change in the vehicle speed as long as the axle torque requirement can be met. By operating the vehicle while maintaining the gear next to the gear next to the next gear, the number of gear shifts can be reduced and the hybrid vehicle can be driven without gear shock or gear delay.

Further, in this type of hybrid vehicle drive structure, changes in the axle rotational speed, the internal combustion engine rotational speed, and the relative relationship therebetween are absorbed by adjusting the first motor / generator rotational speed over the entire vehicle speed range. Since the transmission is provided for responding to a particularly large axle torque demand value, the change of the speed stage with respect to the change of the axle torque demand value can be achieved by simply changing the transmission to the conventional internal combustion engine. Not as strict as in a combined vehicle drive structure. Therefore, when the speed stage of the transmission is changed, an appropriate predetermined time is set, and the shift to the next speed stage is prohibited until such a predetermined time elapses, thereby impairing the transmission function of the transmission. Therefore, it is possible to prevent the operation of the transmission from becoming unstable due to the required axle torque value fluctuating in the vicinity of the boundary of the gear shift. Further, by providing such a switching prohibition time, shift hunting occurs without dividing the shift boundary lines into those for upshifting and those for downshifting, and separating both boundary lines from each other to provide hysteresis therebetween. You can avoid that.

Further, in this type of hybrid vehicle drive structure, changes in the axle rotational speed, the internal combustion engine rotational speed, and the relative relationship therebetween are absorbed by adjusting the first motor generator rotational speed over the entire vehicle speed range. If the first or second motor generator can be operated beyond its rated output for a short period of time, there is no problem, so it is necessary to change the gear to meet the required axle torque value. It is possible to respond by changing the output of at least one of the first and second motor-generators instead of changing the gear stage only within a predetermined time, and the frequency of gear changeovers can also be reduced by this procedure. Moreover, it is possible to avoid the occurrence of gear shift hunting.

Further, the driving method can be switched between a normal driving mode and a sports driving mode, and when the driving mode is switched to the sports driving mode, the transmission is held at the high speed stage regardless of the change of the vehicle speed. If it is released, the transmission can be operated in the conventional operating mode without restraining the operation of the transmission provided according to the driver's preference and the undulating state of the driving area. The driving characteristics of can be expanded.

[0027]

4 and 5, the output shaft of an internal combustion engine is connected to a first motor generator and a wheel drive shaft via a power distribution mechanism as shown in FIG. Two embodiments in which a hybrid vehicle drive structure in which a second motor generator is coupled with a transmission according to the above-mentioned Japanese Patent Application No. 2001-323578 to constitute a hybrid vehicle drive structure which is a target of the driving method according to the present invention 2 is a schematic view similar to FIG. 4 and 5, parts corresponding to those shown in FIG. 1 are designated by corresponding reference numerals.

In the first hybrid vehicle drive structure shown in FIG. 4, the transmission 100 is provided in the middle of the wheel drive shaft and closer to the internal combustion engine than the connecting portion of the second motor generator MG2. In terms of the description of FIG. 1, a part of the propeller shaft 11 forming a part of the wheel drive shaft, which is M
It is provided closer to the internal combustion engine than the gear 15 forming the connecting portion of G2. The transmission 100 may have two or three gears, and may further include a reverse gear. Although such a transmission can be obtained in various modes by a known technique, an example of a transmission having three forward gears and a reverse gear is schematically shown in FIG.

In FIG. 6, reference numerals 20, 22, 24 and 26 designate a sun gear, a ring gear and a planetary gear mechanism, respectively.
Planetary pinion, carrier, also 21, 2
3, 25 and 27 are sun gears, ring gears, planetary pinions and carriers that constitute another planetary gear mechanism, and 28 (C1) and 29 (C2) are clutches,
30 (B1) and 31 (B2) are brakes, 32
(F1) is a one-way clutch. These rotary elements have 33 as an input shaft and 34 as an output shaft,
In the meantime, if it is combined as shown, the clutch C
The first speed stage having the largest reduction ratio is achieved by engaging 1 and the second speed stage having an intermediate reduction ratio is achieved by engaging the clutch C1 and the brake B1. And C2 are engaged, the third speed ratio having the smallest reduction ratio (reduction ratio = 1) is achieved, and the clutch C
The reverse gear is achieved by the engagement of 2 and the brake B2.

In the hybrid vehicle drive structure of FIG. 4,
Assuming that the transmission 100 is configured to provide three speeds, the torque sharing seen in the vehicle speed versus axle torque coordinate system is:
According to the conventional concept of gear shift, in which the transmission is switched so as to obtain a harmony between the internal combustion engine speed and the axle speed, as compared with FIG. May be changed as follows. In this diagram, regions B1, B2, and B3 represent torques that can cover the axle torque in the internal combustion engine by setting the transmission to the first speed, the second speed, and the third speed, respectively. Shows the size,
The MG 2 only needs to be able to cover the remaining area C. (FIG. 7 is not a so-called shift diagram, and therefore, for example, the fact that the vehicle speed and the axle torque demand value are values along the coordinates within the region B1 indicates that the gear stage is set to the first speed stage. It does not mean.)

In the hybrid vehicle drive structure shown in FIG. 5, the transmission 101 is provided in the middle of the wheel drive shaft and on the side remote from the internal combustion engine with respect to the connecting portion of the second motor generator MG2. In terms of the description of FIG. 1,
It is a part of a propeller shaft 11 forming a part of a wheel drive shaft, and is provided on a side farther from an internal combustion engine than a gear 15 forming a connecting portion of MG2. The transmission 101 may also have two or three gears, may further include a reverse gear, and may be as shown in FIG.

In the hybrid vehicle drive structure of FIG.
Assuming that the transmission 101 is configured to provide three speeds, the torque sharing region corresponding to the speed in the vehicle speed versus axle torque coordinate system is also the same as in the conventional concept of speed change. As compared with FIG. 3 in the case where there is no such transmission, for example, it may be changed as shown in FIG. In this diagram, regions B1, B2, and B3 represent the magnitudes of torques provided by the internal combustion engine by setting the transmission to the first speed, the second speed, and the third speed, respectively. Area C1, C
Reference numerals 2 and C3 represent the magnitudes of the torques covered by the MG2 by setting the transmission to the first speed, the second speed, and the third speed, respectively. Also in this case, as can be seen from FIG. 8, the maximum torque required for the MG2 is significantly reduced as compared with the case of FIG.

However, according to the present invention, the hybrid vehicle drive structure as shown in FIGS. 4 and 5 is viewed in the coordinate system of the vehicle speed versus the axle torque indicating the axle torque demand corresponding to the vehicle speed, and FIGS. As shown in FIG. 10, it is proposed to drive the vehicles in proportion to the shift speed. That is, in any case, when viewed in the coordinate system of the vehicle speed versus the axle torque, the inside of the drivable area bordered by the line A is defined by the boundary line parallel to the vehicle speed axis according to the magnitude of the axle torque required value. It is a partition. This is because, in the case of FIG. 9, when the transmission is switched to the third speed, it is possible to cover the axle torque of a size obtained by adding the region B3 and the region C corresponding to the vehicle speed. When the gearbox is switched to the second gear, it is possible to further cover the axle torque having a magnitude added with the region B2 corresponding to the vehicle speed, and when the transmission is switched to the first gear, Further, it means that it is possible to cover the axle torque having a magnitude obtained by adding the region B1 corresponding to the vehicle speed.

Further, in the case of FIG. 10, when the transmission is switched to the third speed, the range B corresponding to the vehicle speed is obtained.
It is possible to cover the axle torque of a size obtained by adding 3 and the region C3, and when the transmission is switched to the second speed stage, a size obtained by adding the region B2 and the region C2 corresponding to the vehicle speed. Of the vehicle, and when the transmission is switched to the first gear, it is possible to further cover the axle torque of a size obtained by adding the region B1 and the region C1 corresponding to the vehicle speed. Means By doing so, unless the required drive torque of the axle is high, adjustment of the difference between the internal combustion engine speed and the vehicle speed is performed by the power distribution mechanism without depending on the gear shift of the transmission,
Only when the required drive torque of the axle becomes high can this be dealt with with the help of the torque increasing function of the transmission.

However, the hybrid vehicle drive structure as shown in FIGS. 4 and 5 may be operated in a speed change section as shown in FIGS. 7 and 8, respectively.
Therefore, it is possible to switch between different driving modes such as a normal driving mode and a sports driving mode, and operate by switching the driving mode according to the driver's preference and the undulation state of the road surface in the area where the vehicle is driven. The hybrid vehicle drive structure may be operated according to FIG. 9 or 10 in the normal operation mode, and may be operated according to, for example, FIG. 7 or 8 in the sports operation mode.

Control for switching the transmission as shown in FIG. 6 between the first speed change step, the second speed change step, and the third speed change step by controlling the engagement or disengagement of the clutches C1, C2 and the brakes B1, B2 is performed. Although not shown in the figure, any known vehicle driving control that includes a microcomputer and controls the driving of the vehicle based on signals from various commands that detect a driving command from the driver and the operating state of the vehicle 7 or 8 and 9 or 1
Given an axle torque sharing map by shifting vehicle speed versus axle torque such as 0, it is easy for those skilled in the art to operate the transmission in accordance with this map.

Further, in the operation according to the axle torque sharing map shown in FIG. 9 or FIG. 10 of the hybrid vehicle drive structure shown in FIG. It will be obvious to a person skilled in the art to prohibit switching to the next speed stage until the time elapses, without needing to specifically illustrate the embodiment.

Further, as understood from the illustrated hybrid vehicle drive structure in which the internal combustion engine and MG1 and MG2 are combined by the planetary gear mechanism, the internal combustion engine is operated at a certain output state and the axle torque When the required value suddenly rises, the axle torque can be increased by increasing the output of at least one of MG1 and MG2 without increasing the output torque to the wheel drive shaft by switching the shift stage of the transmission to the low speed side. It is possible to cope with an increase in the required value. However, in that case, the increase in the axle torque demand value is from region B3 to region B2 or from region B2 to region B.
It is preferable for operating MG1 and MG2 within the rated load that such an increase in axle torque is dealt with by shifting the transmission when the transition to 1 is promoted. Therefore, in such a case, MG1 or MG
The problem was dealt with by increasing the output of 2 is MG1 or MG
2 may operate above the rated output. However, even if the MG1 or MG2 is loaded with a load equal to or higher than the rated output, it is considered to be allowed as long as it is within a predetermined time.

Therefore, when the required value of the axle torque increases so as to promote the transition from the region B3 to the region B2, the axle torque is increased by at least one of MG1 and MG2 instead of switching the shift speed until a predetermined time elapses. By doing so, it is possible to prevent the transmission from being frequently switched with respect to a very temporary increase in the axle torque demand value,
The operation of the hybrid vehicle drive structure can be made smoother and quieter. According to the above description of FIG. 1 and the operation thereof, the operation control of such a hybrid vehicle drive structure is also a known vehicle operation control in the field of the present technology, even if the control sequence is not shown in the flowchart or the like and described. It will be apparent to those skilled in the art that this can be easily done with the device.

Although the present invention has been described in detail with reference to some embodiments in the above, the present invention is not limited to these embodiments, and various other implementations are possible within the scope of the present invention. It will be apparent to those skilled in the art that examples are possible.

[Brief description of drawings]

FIG. 1 is a schematic view showing a prototype of a hybrid vehicle drive structure which is a target of a driving method according to the present invention.

2 is a rotational speed N of an internal combustion engine and two motor generators MG1 and MG2 in the hybrid vehicle drive structure shown in FIG.
A diagram showing the relationship between c, Ns, and Nr.

3 is a diagram showing the magnitude of axle torque to be shared by an internal combustion engine and a motor generator MG2 in the hybrid vehicle drive structure shown in FIG. 1 with respect to vehicle speed.

FIG. 4 is a schematic diagram showing a first embodiment of an improvement which is a target of a driving method according to the present invention with respect to the hybrid vehicle drive structure shown in FIG.

5 is a schematic view showing a second embodiment of the improvement targeted by the driving method according to the present invention with respect to the hybrid vehicle drive structure shown in FIG. 1. FIG.

FIG. 6 is a schematic diagram showing an example of a transmission that provides three shift speeds and a reverse speed.

FIG. 7 is a block diagram of the hybrid vehicle drive structure shown in FIG.
FIG. 9 is a diagram showing the magnitude of axle torque to be shared by each of the internal combustion engine and the motor generator MG2 with respect to the vehicle speed when the transmission is operated in the conventional shift mode.

FIG. 8 is a view showing the hybrid vehicle drive structure shown in FIG.
FIG. 9 is a diagram showing the magnitude of axle torque to be shared by each of the internal combustion engine and the motor generator MG2 with respect to the vehicle speed when the transmission is operated in the conventional shift mode.

9 is a view showing the hybrid vehicle drive structure shown in FIG.
FIG. 6 is a diagram showing the magnitude of axle torque to be shared by each of the internal combustion engine and the motor generator MG2 with respect to the vehicle speed when the transmission is operated in the shift mode of the present invention.

FIG. 10 is a magnitude of axle torque to be shared by each of the internal combustion engine and the motor generator MG2 when the transmission is operated in the speed change mode of the present invention in the hybrid vehicle drive structure shown in FIG. FIG.

[Explanation of symbols]

1 ... Internal combustion engine 2 ... Output shaft of internal combustion engine 3 ... Planetary gear device 4 ... Sun gear 5 ... Ring gear 6 ... Planetary pinion 7 ... Career 8 ... First motor generator (MG1) 9 ... Coil 10 ... rotor 11 ... Propeller shaft 12 ... Second motor generator (MG2) 13 ... Coil 14 ... rotor 15, 16 ... Gears 17 ... Differential device 18 ... Axle 19 ... Wheels 20 ... Sun gear 22 ... Ring gear 24 ... Planetary Pinionya 26 ... Career 21 ... Sun gear 23 ... Ring gear 25 ... Planetary pinion 27 ... Career 28, 29 ... Clutch 28, 29 ... Brakes 32 ... One-way clutch 100, 101 ... Transmission

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Claims (6)

[Claims] 1. An output shaft of an internal combustion engine is connected to a first motor generator and a wheel drive shaft via a power distribution mechanism, a second motor generator is connected to the wheel drive shaft, and the wheel drive shaft is connected. As long as it is possible to meet the axle torque required value by setting the transmission to a predetermined high-speed stage and operating the internal combustion engine with high fuel efficiency, a method of operating a hybrid vehicle drive structure in which a transmission is provided in the middle of A method for operating a hybrid vehicle drive structure, characterized in that the vehicle is operated while holding the high speed stage regardless of changes in the vehicle speed. 2. The axle torque request value cannot be met when the transmission is set to the high speed stage, but the axle torque demand value can be met if the transmission is set to the next lower speed stage after the high speed stage. As long as possible, the hybrid vehicle drive structure operating method according to claim 1, wherein the transmission is operated while being held at a gear next to the high speed regardless of changes in the vehicle speed. 3. When the transmission is set to a gear next to the high speed, it cannot meet the required axle torque value, but the gear is shifted to the next lower speed after the high speed. If it is set to a gear, as long as it is possible to meet the axle torque demand value, the transmission is held at the gear next to the gear next to the high gear regardless of the change in the vehicle speed, and is operated. The hybrid vehicle drive structure operating method according to claim 2. 4. The hybrid vehicle according to claim 1, wherein when the speed stage of the transmission is switched, the switching of the next speed stage is prohibited until a predetermined time elapses. Drive structure operating method. 5. When it is necessary to change the shift speed in order to correspond to the required value of the axle torque, at least one of the first and second motor generators is replaced with the change of the shift speed only within a predetermined time. The hybrid vehicle drive structure operating method according to any one of claims 1 to 4, characterized in that the output is changed. 6. Switching between a normal driving mode and a sports driving mode, and when the sports driving mode is switched, releasing the transmission from holding the high speed stage regardless of changes in the vehicle speed. The hybrid vehicle drive structure operating method according to any one of claims 1 to 5.