JP3593992B2 - Drive unit for hybrid vehicle - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a drive device for a hybrid vehicle that can be switched between a parallel hybrid and a series hybrid.
[0002]
[Prior art]
As a conventional device of this type, for example, a device described in JP-A-2000-209706 is known.
[0003]
In the above source, the engine is connected to the carrier of the planetary gear unit, the electric motor (generator) is connected to the sun gear, the electric motor and the axle are connected to the ring gear, and a clutch is provided between the planetary gear unit and the electric motor to enable disconnection and connection of both. . Further, a brake for fixing the ring gear when the clutch is disengaged is provided. The configuration of the parallel hybrid vehicle is realized by engaging the clutch and releasing the brake, and the series hybrid vehicle is realized by releasing the clutch and fixing the ring gear with the brake.
[0004]
[Problems to be solved by the invention]
However, the above-described conventional hybrid vehicle drive device includes a clutch provided between the planetary gear device and the electric motor, a brake for fixing the ring gear, and disconnection and connection of the two clutches and the brake by hydraulic pressure to form a parallel hybrid. Since the structure is such that the series hybrid is switched, the size of the device is increased because two hydraulic clutches and a brake are arranged.
[0005]
Also, if the clutch and brake are coupled together during driving, the device locks up.To prevent this, if the hydraulic circuit has a fail-safe function or if complicated control is performed, No.
[0006]
Furthermore, the motor connected to the sun gear mainly acts as a generator, and can only operate as a motor during high-speed operation.Therefore, when starting, it must be performed only with the motor connected to the axle. There is a problem that a large-capacity electric motor is required to obtain an appropriate driving force.
[0007]
An object of the present invention has been made in view of the above technical problems of the related art, and has as its object to provide a drive device for a hybrid vehicle having both a parallel type and a series type with a relatively simple structure. .
[0008]
[Means for solving the problem]
The first invention has an engine, a generator, and a motor for driving driving wheels, and outputs a part of the output of the engine to the generator and the rest to the driving wheels via a planetary gear device and an output gear. In the hybrid vehicle drive device, a carrier of the planetary gear device is connected to an output shaft of the engine, a sun gear of the planetary gear device is connected to a rotation shaft of the generator, and a ring gear of the planetary gear device is connected to the ring gear. A brake means for transmitting rotation to the output gear from the output gear through a one-way clutch that does not transmit rotation in the opposite direction to the output gear, and enabling the rotation of the ring gear to be connected to and disconnected from the case. It is characterized by having.
[0009]
According to a second invention, in the first invention, the brake means is constituted by a hydraulic brake.
[0010]
According to a third aspect, in the first aspect, the brake means is constituted by an electromagnetic brake.
[0011]
A fourth invention is characterized in that in the first invention, the brake means is constituted by a clutch having a function of idling rotation of the ring gear and a function of preventing rotation of the ring gear with respect to the case. is there.
[0012]
According to a fifth aspect, in the first to fourth aspects, a reverse rotation preventing mechanism is provided on an output shaft of the engine.
[0013]
In a sixth aspect based on the first to fifth aspects, an oil pump is provided on a rotation shaft of the output gear via a reverse rotation preventing mechanism.
[0014]
In a seventh aspect based on the first to fifth aspects, an oil pump is provided on the rotating shaft of the generator via a first reverse rotation preventing mechanism, and a second reverse rotation preventing mechanism is further provided on the rotating shaft of the output gear. An oil pump is provided via the oil pump.
[0015]
[Action and effect]
In the hybrid vehicle provided with the drive device according to the present invention, the vehicle starts when the engine is stopped by the forward or reverse rotation of the electric motor. At this time, the generator does not operate and is in a stopped state.
[0016]
When the engine is started, brake means (friction brake or the like) for connecting and disconnecting the rotation of the ring gear of the planetary gear device to and from the case is engaged, and the generator is operated as a starter. The driving force of the generator (starter) is transmitted to the engine via the planetary gear device, and the engine is started. A one-way clutch that transmits rotation from the ring gear to the output gear but does not transmit rotation in the opposite direction is arranged between the output gear and the ring gear, so the rotation of the ring gear is braked while the vehicle is running with the electric motor. Locking does not occur even if the means is fixed by fastening, and rotation of the output gear is not affected.
[0017]
After the engine is started, if the brake means is kept in the engaged state, the generator can be driven by the driving force of the engine to generate electric power, and the series running of driving the electric motor with the obtained electric power can be performed. Become. The capacity of the generator and the motor are set to the same level, the engine is operated in the optimum efficiency state to generate power, and the obtained electric power is supplied directly to the motor without passing through the battery, so that the capacity and size of the battery can be reduced. . In addition, since the vehicle runs only with the electric motor without assisting the vehicle driving force from the engine, the electric motor can be operated under a high load state, and the electric motor can be operated in an efficient state.
[0018]
When the driving force required for traveling cannot be obtained with the electric motor alone, the brake means is released, and the output of the engine, the rotation of the generator and the absorption torque are controlled in accordance with the traveling state, and the By operating the planetary gear device as a continuously variable transmission, parallel running in which the remaining output of the engine output used for power generation is transmitted to driving wheels as vehicle driving force becomes possible. Since the driving force can be generated by both the electric motor output and the engine output, the size of the electric motor can be reduced compared to a drive device for a hybrid vehicle that only runs in series.
[0019]
Also, in both the series and parallel running, at the time of deceleration, the battery can be charged as regenerative electric power by operating the motor as a generator during deceleration.
[0020]
As described above, according to the present invention, it is possible to switch between series running and parallel running by connecting and disconnecting only the above-mentioned brake means, and a drive device for a hybrid vehicle utilizing both the series type and the parallel type is complicated. It can be realized with a relatively simple structure without requiring control and without increasing the size of the device.
[0021]
The brake means can be constituted by a hydraulic brake (second invention). In this case, the hydraulic brake is engaged and released by the hydraulic pressure generated by an oil pump. Further, the brake means may be constituted by an electromagnetic brake (third invention). In this case, engagement and release of the brake are performed by controlling electric power supplied to the electromagnetic brake. Therefore, there is an advantage that a high-pressure hydraulic pump is not required.
[0022]
Further, the brake means may be constituted by a bidirectional clutch (fourth invention). In this case, the rotation restriction direction at the time of starting the engine, the rotation restriction direction during the series operation, and the neutral (open) state during the parallel operation are switched by the electric actuator. Therefore, not only does a high-pressure hydraulic pump not be required, but also the rotation is mechanically performed, so that even when the rotation is restricted, there is an advantage that power is not required and power consumption is suppressed.
[0023]
According to the fifth aspect of the present invention, a reverse rotation preventing mechanism (for example, a one-way clutch for preventing reverse rotation) is inserted between the output shaft of the engine and the case, so that the generator can be rotated without rotating the engine reversely when the engine is stopped. The motor can be operated as an electric motor, and the driving force can be obtained from the two electric motors, so that the traveling performance of the electric vehicle can be improved.
[0024]
According to the sixth aspect, when the brake means is a hydraulic brake for lubricating each rotating element, an oil pump for operating the hydraulic brake can be further provided on the rotating shaft of the output gear. Thus, the oil pump can be driven by the electric motor when the engine is stopped and by the engine when the engine is running, and a new oil pump drive source is not required. Further, since a reverse rotation preventing mechanism (for example, a one-way reverse rotation preventing clutch) is interposed between the output gear shaft and the oil pump, it is possible to prevent the oil pump from being driven in the reverse direction when the oil pump reverses. .
[0025]
According to the seventh invention, when the brake means is a hydraulic brake, an oil pump for operating the hydraulic brake via a reverse rotation preventing mechanism such as a reverse rotation preventing one-way clutch on a rotating shaft of a generator. And an oil pump for lubricating each rotating element can be provided on the rotating shaft of the output gear via a reverse rotation preventing mechanism. Accordingly, when the engine is started by the electric motor during traveling, the oil pump can be driven by using the generator as the electric motor, so that the driving force of the electric motor does not decrease. Further, since the oil pump for lubrication is arranged on the rotation shaft of the output gear, the oil pump is also driven as the vehicle travels, so that lubricating oil can be sent to each rotating element (lubricating portion).
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0027]
FIG. 1 shows an example in which a drive device according to the present invention is applied to a front-wheel drive hybrid vehicle. In FIG. 1, 1 is an engine, 2 is a planetary gear device, 3 is a generator, 4 is a drive or regeneration motor, and 8R. , 8L are drive wheels (front wheels).
[0028]
The output shaft 1a of the engine 1 is connected to a carrier 2C supporting a planetary gear 2P of the planetary gear device 2, and a generator 3 is connected to a sun gear 2S of the planetary gear device 2. The ring gear 2R of the planetary gear device 2 is provided with a brake 10 as a brake means for connecting and disconnecting the rotation of the ring gear 2R to and from the case 9. When the brake 10 is engaged, the relative rotation between the ring gear 2R and the case 9 is reduced. Can be regulated.
[0029]
Further, the ring gear 2R is connected to the output gear 5a via a one-way clutch 11 as a rotation transmission direction regulating means. By interposing the one-way clutch 11, the rotation is transmitted from the ring gear 2R to the output gear 5a, but the rotation is not transmitted in the opposite direction.
[0030]
The driving force from engine 1 transmitted to output gear 5a is transmitted to driving wheels 8R and 8L via idler gear 5b, final pinion 6a, final ring gear 6b, and drive shafts 7R and 7L. Further, the driving force from the electric motor 4 is also transmitted from the electric motor output gear 5c to the idler gear 5b, and then transmitted to the driving wheels 8R and 8L through the same path.
[0031]
The generator 3 and the electric motor 4 are controlled by a controller (not shown) via each driver circuit. The controller receives a vehicle speed signal, an engine speed signal, a throttle opening signal, a battery SOC (charge state) signal, a brake signal, a shift lever position signal, a backlight signal, and the like.
[0032]
Next, the specific control content and its operation will be described.
[0033]
At the time of starting, it is determined whether the vehicle moves forward or backward based on the shift lever position signal and the backlight signal, and the electric motor 4 is operated in a desired direction. The driving force of the electric motor 4 is transmitted to the left and right driving wheels 8R, 8L through the electric motor output gear 5c, the idler gear 5b, the final pinion 6a, the final ring gear 6b, and the drive shafts 7R, 7L. At this time, the generator 3 is stopped without operating.
[0034]
The engine 1 is started by operating the generator 3 as a starter. When the brake 10 is engaged and the generator 3 is operated as an electric motor, the driving force due to this is reduced by the planetary gear device 2 and transmitted to the engine 1 via the carrier 2C and the engine output shaft 1a, and the engine 1 is started. Is done. The engine 1 can be started by the same operation when the vehicle is stopped or when the electric motor 4 is running.
[0035]
After the engine is started, while the vehicle can run with the driving force of the electric motor 4 alone, the engagement of the brake 10 is maintained, and the engine 1 is optimized based on the vehicle speed signal, the output of the electric motor 4, the throttle opening signal, and the battery SOC signal. The operation is performed in an efficient state, and power is generated by the generator 3 with the driving force. The obtained electric power is directly supplied to the electric motor 4 without passing through a battery (not shown). At this time, the excess power is controlled to be stored in the battery.
[0036]
On the other hand, when the electric motor 4 alone cannot provide the driving force necessary for traveling, the brake 10 is released, and the judgment is made based on the vehicle speed signal, the output of the electric motor 4, the throttle opening signal, the engine speed signal, and the battery SOC signal. In addition, while the engine 1 is operated in the optimum efficiency state, the generator 3 generates electric power with a part of the driving force. At this time, the remaining driving force is transmitted from the ring gear 2R of the planetary gear device 2 to the output gear 5a, and transmitted to the driving wheels 8R, 8L via the idler gear 5b, the final pinion 6a, the final ring gear 6b, and the drive shafts 7R, 7L. Is done. The driving force of the electric motor 4 is also transmitted from the electric motor output gear 5c to the drive wheels 8R and 8L via the idler gear 5b, the final pinion 6a, the final ring gear 6b, and the drive shafts 7R and 7L. Therefore, the drive wheels 8R and 8L are driven by both the engine 1 and the electric motor 4, and a large driving force required for running the vehicle can be obtained.
[0037]
In any of the running states, the motor 4 acts as a generator during deceleration to regenerate deceleration energy and charge the battery with the electric power.
[0038]
As described above, in the hybrid vehicle drive device according to the present invention, the hybrid vehicle drive device capable of both the series and parallel traveling modes does not require complicated control and has a relatively simple structure. And a fail-safe function for preventing the vehicle from locking, which is required in the related art, is not required. Also, since the generator is not entrained during the EV mode running, there is an advantage that power loss due to the generator does not occur.
[0039]
Further, by switching between the series and parallel traveling modes according to the traveling state, the engine and the electric motor can be operated efficiently, and the fuel efficiency can be improved. Further, since the characteristics of both the series system and the parallel system can be utilized, there is an advantage that the capacity or size of the electric motor or the battery can be reduced.
[0040]
The brake 10 can be constituted by a hydraulic brake. In this case, the application and release of the brake 10 are performed by the hydraulic pressure generated by an oil pump. Further, the brake 10 can be constituted by an electromagnetic brake. In this case, the engagement and release of the brake 10 are performed by controlling the electric power supplied to the brake 10. If the brake 10 is constituted by an electromagnetic brake instead of a hydraulic brake, there is an advantage that a high-pressure hydraulic pump becomes unnecessary.
[0041]
Further, as shown in FIG. 2, instead of the brake 10, a clutch 16 having a function of idling the rotation of the ring gear and a function of preventing the rotation of the ring gear with respect to the case may be provided. Hereinafter, a case where a two-way clutch such as an electromagnetic mechanical clutch described in Japanese Patent Application Laid-Open No. 11-159544 will be described.
[0042]
As shown in FIG. 3, the two-way clutch has a roller 50, a retainer 51, a connecting member 57, an outer race 91, and an inner race 92, and the outer race 91 and the inner race 92 are fastened by excitation of an electromagnetic coil. , Select the released state. In this structure, the outer race 91 is fixed to the case 9, and the inner race 92 is connected to the ring gear 2 </ b> R of the planetary gear device 2.
[0043]
When the electromagnetic coil is not excited, the connecting member 57 is located in the middle of the notches 51A, 51A of the holder 51 as shown in FIG. At this intermediate position, the roller 50 is not in contact with the outer race 91, the outer race 91 and the inner race 92 can rotate relative to each other, and the ring gear 2R of the planetary gear device 2 is released from the case 9.
[0044]
On the other hand, when the electromagnetic coil is excited, as shown in FIG. 3, when the inner race 92 is rotating clockwise in the figure, the coupling member 57 is rotated counterclockwise by the excitation of the electromagnetic coil, As shown in FIG. 3B, the protrusion 57A presses the notch 51A of the retainer 51 counterclockwise.
[0045]
By rotating the retainer 51 counterclockwise, the roller 50 rotates on a plane around the inner race 92 toward a plane deviated in the counterclockwise direction from the central portion, as shown in FIG. 3B. When the roller 50 moves and comes into contact with the outer race 91, the roller 50 is sandwiched between the inner race 92 and the outer race 91 by the rotation of the inner race 92, and the inner race 92 and the outer race 91 (case 9) are in a fastening state. Thus, the ring gear 2R of the planetary gear device 2 is in a state of being braked.
[0046]
That is, the rotation restriction direction at the time of engine start, the rotation restriction direction at the time of series operation, and the neutral (open) state at the time of parallel operation are switched by the excitation state (electric actuator) of the electromagnetic coil. This eliminates the need for a high-pressure hydraulic pump and mechanically restricts rotation, so that there is an advantage that power is not required even during rotation restriction.
[0047]
Subsequently, a second embodiment of the present invention will be described.
[0048]
FIG. 4 shows a second embodiment of the present invention, in which a reverse rotation preventing one-way clutch 12 (which allows only rotation of the engine output shaft 1a in the engine rotation direction) is provided between the engine output shaft 1a and the case 9. The second embodiment differs from the first embodiment in that a reverse rotation prevention mechanism is interposed. Other configurations are substantially the same as those of the first embodiment, and the same configurations are denoted by the same reference numerals.
[0049]
By providing such a reverse rotation preventing one-way clutch 12, when the generator 3 is reversely rotated as an electric motor when the engine is stopped, the carrier 2C and the engine output shaft 1a do not rotate with respect to the case 9, and the engine 1 The driving torque of the electric motor 3 is transmitted to the output gear 5a via the sun gear 2S, the planetary gear 2P, and the ring gear 2R without being rotated, and is driven via the idler gear 5b, the final pinion 6a, the final ring gear 6b, and the drive shafts 7R, 7L. 8R and 8L.
[0050]
The driving force of the electric motor 4 is also transmitted from the electric motor output gear 5c to the drive wheels 8R and 8L via the idler gear 5b, the final pinion 6a, the final ring gear 6b, and the drive shafts 7R and 7L.
[0051]
As described above, in the present embodiment, the driving forces of the two electric motors can be simultaneously transmitted to the driving wheels, and in addition to the effects of the previous embodiment, there is an effect that the power performance of the electric vehicle can be improved.
[0052]
Subsequently, a third embodiment of the present invention will be described.
[0053]
FIG. 5 shows a third embodiment of the present invention. An oil pump 13 used to supply lubricating oil to each rotating element or to supply hydraulic pressure required to operate the brake 10 when the brake 10 is a hydraulic brake is a rotary shaft 14 of the output gear 5a. The third embodiment is different from the first embodiment in that the first embodiment is provided via a reverse rotation preventing one-way clutch 13a (reverse rotation preventing mechanism). Other configurations are substantially the same as those of the first embodiment, and the same configurations are denoted by the same reference numerals.
[0054]
The oil pump 13 is driven by the electric motor 4 when the engine 1 is stopped and the electric motor 4 runs, and is driven by the engine 1 when the engine 1 runs.
[0055]
Therefore, in this embodiment, in addition to the effects of the above embodiment, there is an advantage that it is not necessary to separately provide a drive source for the oil pump. Further, since the one-way clutch 13a for preventing reverse rotation is provided between the output gear shaft 14 and the oil pump 13, the oil pump 13 can be prevented from being reversely rotated when the vehicle moves backward.
[0056]
Subsequently, a fourth embodiment of the present invention will be described.
[0057]
FIG. 6 shows a fourth embodiment of the present invention. The brake 10 is constituted by a hydraulic brake, and a high-pressure oil pump 15 for operating the brake 10 via a reverse rotation prevention one-way clutch 15a (reverse rotation prevention mechanism) is provided on a rotating shaft 3a of the generator 3; The first embodiment differs from the first embodiment in that a low-pressure oil pump 13 for lubricating each rotary element is provided on a shaft 14 via a reverse rotation preventing one-way clutch 13a as a reverse rotation preventing mechanism. Other configurations are substantially the same as those of the first embodiment, and the same configurations are denoted by the same reference numerals.
[0058]
In this embodiment, when starting the engine 1 at the time of traveling with the electric motor 4, the oil pump 15 is driven with the generator 3 as the electric motor, and the hydraulic brake 10 is engaged with the hydraulic pressure generated thereby. On the other hand, the lubricating oil pump 13 installed on the rotating shaft 14 of the output gear 5a is driven as the vehicle travels, and lubricating oil is sent to each rotating element.
[0059]
Therefore, in this embodiment, the oil pump 15 can be driven by using the generator 3 as an electric motor when the engine 1 is started when the electric motor 4 is running, and the engine 1 is started while the electric motor 4 is running. However, there is an effect that the traveling driving force by the electric motor 4 is not reduced.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a drive device for a front-wheel drive hybrid vehicle according to the present invention (first embodiment).
FIG. 2 is a diagram showing a modification (an example using a bidirectional clutch) of the first embodiment.
FIG. 3 is a diagram for explaining the operation of a bidirectional clutch.
FIG. 4 is a diagram showing a second embodiment of the present invention.
FIG. 5 is a diagram showing a third embodiment of the present invention.
FIG. 6 shows a fourth embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 1 engine 1a engine output shaft 2 planetary gear device 2S sun gear 2P planetary gear 2C carrier 2R ring gear 3 generator 3a generator rotation shaft 4 motor 5a output gear 5b idler gear 5c motor output gear 6 final gear 6a final pinion 6b final ring gear 7L 7R Front wheel left and right drive shaft 8L, 8R Front wheel left and right wheel 9 Case 10 Brake (hydraulic brake or electromagnetic brake)
DESCRIPTION OF SYMBOLS 11 One-way clutch 12 Engine one-way prevention one-way clutch 13 Oil pump 13a Oil pump reverse-direction prevention one-way clutch 14 Output gear shaft 15 Oil pump 15a Oil pump reverse-direction prevention one-way clutch 16 Two-way clutch 50 Roller 51 Holder 57 Connecting member 91 Outer race 92 Inner race

Claims (7)

An engine, a generator, and a driving device for a hybrid vehicle that includes a motor for driving a driving wheel, and outputs a part of the output of the engine to the generator and the remainder to the driving wheels through a planetary gear device and an output gear. ,
Connecting the carrier of the planetary gear device to the output shaft of the engine,
A sun gear of the planetary gear device is connected to a rotating shaft of the generator,
The ring gear of the planetary gear device is connected to the output gear via a one-way clutch that transmits rotation from the ring gear to the output gear but does not transmit rotation in the opposite direction,
Brake means enabling the rotation of the ring gear to be connected to and disconnected from the case,
A drive device for a hybrid vehicle, comprising: The drive device for a hybrid vehicle according to claim 1, wherein the brake means is constituted by a hydraulic brake. The drive device for a hybrid vehicle according to claim 1, wherein the brake means is configured by an electromagnetic brake. 2. The drive device for a hybrid vehicle according to claim 1, wherein the brake means is constituted by a clutch having a function of idling the rotation of the ring gear and a function of preventing the ring gear from rotating with respect to the case. The drive device for a hybrid vehicle according to any one of claims 1 to 4, wherein a reverse rotation prevention mechanism is provided on an output shaft of the engine. The hybrid vehicle drive device according to any one of claims 1 to 5, wherein an oil pump is provided on a rotation shaft of the output gear via a reverse rotation prevention mechanism. An oil pump is provided on a rotating shaft of the generator via a first reverse rotation preventing mechanism, and an oil pump is provided on a rotating shaft of the output gear via a second reverse rotation preventing mechanism. A drive device for a hybrid vehicle according to any one of claims 1 to 5.

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