JPH09287490A - Hybrid vehicle - Google Patents

Abstract

(57) A hybrid vehicle capable of preventing the deterioration of exhaust emission by maintaining a constant rotation speed and torque of an internal combustion engine with a simple mechanism. A drive wheel 10 is connected to an electric motor 5 via a differential gear 8 and a drive shaft 7, and between the electric motor 5 and the internal combustion engine 1 is dependent on the rotation speed of an output shaft 6 on the electric motor 5 side. A continuously variable transmission 3 that automatically changes the gear ratio is provided so that the rotation speed of the output shaft 2 of the internal combustion engine 1 is controlled to be constant. Further, when the output torque of the internal combustion engine 1 is constant, the drive wheels 10 necessary for traveling are
The difference between the drive torque of
Is controlled to be generated or absorbed by the electric motor 5, it is possible to output the required drive torque while maintaining the generated torque of the internal combustion engine 1 constant.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat engine, for example,
The present invention relates to a hybrid vehicle that uses an internal combustion engine and an electric motor in combination as a power source.

[0002]

2. Description of the Related Art Generally, a hybrid vehicle includes a type (SHV) in which a generator is driven by using an internal combustion engine and an electric motor is driven by using generated electric power to drive the vehicle (SHV). Both an electric motor and an electric motor are connected to the drive shaft, and there are two types, that is, a type (PHV) in which traveling is performed using both or one of them. Since the internal combustion engine and the drive shaft are not connected in the SHV, there is a problem that fuel consumption deteriorates due to power generation loss, battery charge / discharge loss, and the like.
In the HV, there is a problem that the exhaust emission is deteriorated because the generated torque and the rotational speed of the internal combustion engine vary depending on the running state.

Therefore, in order to solve these problems, a differential gear or a planetary gear is used,
A configuration has been proposed in which the output shafts of an internal combustion engine and an electric motor are connected (see, for example, Japanese Patent Laid-Open No. 7-15805). This technology prevents deterioration of fuel consumption by mechanically connecting the output shafts of the internal combustion engine and the electric motor, and controls the rotation speed of the electric motor to keep the rotation speed of the internal combustion engine at a predetermined value. , To prevent the deterioration of emissions.

However, in this configuration, the generated torque of the internal combustion engine fluctuates depending on the running load torque, so that the effect of preventing deterioration of emission is insufficient. On the other hand, a technique in which an electric motor is separately provided on the drive shaft and the torque generated by the internal combustion engine is set to a predetermined value is disclosed in, for example, JP-A-50-30.
No. 223 is disclosed. However, since the technique disclosed in this publication uses a plurality of planetary gear mechanisms, it has another problem that the configuration becomes complicated.

[0005]

SUMMARY OF THE INVENTION The present invention addresses the above-mentioned problems in the prior art and makes the rotational speed and torque generated by an internal combustion engine constant without complicating the structure. An object of the present invention is to provide an improved hybrid vehicle that can improve fuel efficiency and reduce exhaust emission.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the means described in claim 1 can be adopted. According to this means, even if the rotation speed of the drive shaft connected to the drive wheels fluctuates, the rotation speed of the heat engine is kept constant by the action of the transmission, so that the structure of the drive system is not complicated. It is possible to prevent deterioration of exhaust emission. Also,
By adopting the means described in claim 2, the required drive torque can be generated (including output and absorption) by the electric motor while the generated torque of the heat engine is kept constant. Exhaust emission deterioration due to fluctuations in the torque generated by the heat engine can be prevented without complicating.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION First and second embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a basic configuration of a hybrid vehicle common to these embodiments. In FIG. 1, a heat engine that converts thermal energy into driving force, for example, an output shaft 2 of an internal combustion engine 1 is connected to an input shaft of a transmission 3, and an output shaft of the transmission 3 converts electric energy into driving force. It is connected to a device, for example, the output shaft 6 of the electric motor 5. The other end of the output shaft 6 is connected to a drive wheel 10 through a drive shaft 7 and a differential gear 8, and the torque generated by the internal combustion engine 1 and the electric motor 5 is transmitted to the drive wheel 10.

The electric motor 5 is connected to the battery 12 through an inverter 11, and the inverter 11 is provided with a controller such as an electronic control unit (not shown) for controlling the electric motor 5. When the electric motor 5 generates a torque, the battery 12 is discharged, and when the electric motor 5 absorbs the torque, it works as a generator to operate as a battery.
Charged to 2.

The transmission 3 has an output shaft 6 on the electric motor 5 side.
The gear ratio can be automatically changed according to the number of revolutions of the internal combustion engine 1 by the transmission 3.
The rotation speed of the output shaft 12 is controlled to be constant. Further, the torque generated by the internal combustion engine 1 is set so as to be always constant, and the difference between the torque of the drive wheels necessary for traveling and the torque of the output shaft of the transmission 3 (which changes depending on the gear ratio) is: A controller (not shown) controls the inverter 11 so that the electric motor 5 is generated (including output and absorption).

Next, a specific internal structure of the transmission 3 used in the first embodiment of the present invention will be described with reference to FIGS. 2 to 4. The output shaft 2 of the internal combustion engine 1 is fixed to a bevel gear 13, and the bevel gear 13 meshes with another bevel gear 16 provided on a planet cone 15. The planet cone 15 is rotatably supported by a carrier 17, and the carrier 17 is fixed to a common output shaft 6 of the electric motor 5 and the transmission 3. The output shaft on the opposite side of the electric motor 5 (not shown) is connected to the drive shaft 7. A cone portion 18 is provided at the tip of the planetary cone 15, and the outer peripheral surface of the cone portion 18 makes frictional contact with an annular protrusion 21 formed on the inner surface of a slide ring 20 slidable in the axial direction. are doing.

A plurality of holes are formed in the side surface of the slide ring 20 on the electric motor 5 side, and one end of a rotation stop pin 22 of the slide ring 20 is fixed to these holes. These detent pins 22 are attached to the housing 23
Is slidably inserted in a hole 25 formed in the side wall of the electric motor 5 side. A spring 26 is provided on the outer periphery of the rotation stopping pin 22. The spring 26 normally presses the slide ring 20 toward the internal combustion engine 1 (left side in the drawing). Further, as shown in FIG. 3, a plurality of, for example, four radial grooves 27 are formed on the side surface of the carrier 17 on the electric motor 5 side.
A ball 30 is rotatably held between the inside and the inner end surface 28 of the slide ring 20. And the groove 2
The depth of 7 is deeper as it is closer to the output shaft 6, and is formed so as to be shallower as it goes away from the output shaft 6.

Therefore, when the electric motor 5 is stopped or is rotating at a low speed, the balls 30 do not receive the centrifugal force, or even if they receive the centrifugal force, the influence thereof is small.
0 is near the output shaft 6, and the slide ring 20 does not move. As a result, in the state shown in FIG. 2, the torque of the output shaft 6 of the electric motor 5 is transmitted to the bevel gear 16 of the planetary cone 15 via the carrier 17. Therefore, if there is a difference between the rotation speed of the output shaft 6 of the electric motor 5 and the rotation speed of the output shaft 2 of the internal combustion engine 1, the planet cone 15 revolves while revolving. In this way, the output shaft 2 of the internal combustion engine 1
And the output shaft 6 of the electric motor 5 transmits torque. At this time, since the protrusion 21 in the slide ring 20 is in contact with the smallest effective radius portion of the cone portion 18, the gear ratio of the transmission 3, that is, the speed reduction ratio is the largest.

On the contrary, when the rotation speed of the electric motor 5 rises and reaches the maximum, the rotation speed of the carrier 17 also rises to the maximum and a large centrifugal force acts on the ball 30.
0 moves to the radially outermost side as shown in FIG. Therefore, the slide ring 20 moves to the electric motor 5 side (the right side in the drawing) against the biasing force of the spring 26, and the protrusion 21 inside the slide ring 20 has the maximum effectiveness of the cone portion 18 of the planetary cone. Since it comes into contact with the portion having the radius, the reduction ratio of the transmission 3 becomes the smallest. In this way, the rotation speed of the output shaft 2 of the internal combustion engine 1 is always controlled to be constant.

Next, the operation when the continuously variable transmission 3 used in the first embodiment of the present invention is installed in a hybrid vehicle as shown in FIG. 1 will be described. First, when the vehicle speed of the hybrid vehicle increases, the rotation speed of the drive shaft 7 increases, and the rotation speed of the output shaft 6 of the electric motor 5 increases. As a result, the number of rotations of the carrier 17 also rises, so that the balls 30 rotate around the output shaft 6 together with the carrier 17 and receive the centrifugal force. When the ball 30 moves radially outward along the groove 27 due to the centrifugal force, the slide ring 20 moves to the electric motor 5 side (right side in FIG. 2) against the biasing force of the spring 26. Therefore, as described above, the contact point between the cone portion 18 and the annular protrusion 21 inside the slide ring 20 moves to the right side in FIG. 2, and the effective radius of the cone portion 18 increases as shown in FIG. Therefore, the speed reduction ratio of the transmission 3 becomes smaller. That is, when the rotation speed of the output shaft side (electric motor side) of the transmission 3 increases, the reduction ratio of the transmission 3 decreases, so that the rotation speed of the output shaft 2 of the internal combustion engine 1 can always be kept constant. it can.

On the contrary, when the vehicle speed of the hybrid vehicle decreases, the rotation speed of the drive shaft 7 decreases and the electric motor 5
The rotation speed of the output shaft 6 also decreases. As a result, the number of rotations of the carrier 17 is also reduced, so that the centrifugal force acting on the ball 30 is also reduced, and the ball 30 is centripetally moved along the groove 27 toward the output shaft 6 side. As a result, since the slide ring 20 moves to the internal combustion engine 1 side (left side in FIG. 2) by the action of the spring 26, the contact point between the cone portion 18 and the protrusion 21 inside the slide ring 20 is shown in the figure. The gear 3 moves to the left and the effective radius of the cone portion 18 becomes smaller, so that the reduction ratio of the transmission 3 becomes larger. That is, the transmission 3
When the number of rotations on the output shaft side (the side of the electric motor 5) decreases, the reduction ratio of the transmission 3 increases, so that the number of rotations on the input shaft side of the transmission 3, that is, the output shaft of the internal combustion engine 1 becomes constant. Can be kept at

As described above, the transmission 3 can automatically change the gear ratio in accordance with the change in the rotational speed of the output shaft connected to the electric motor 5, and therefore the rotational speed of the output shaft of the internal combustion engine. Can be controlled to be constant. Regarding the torque, a controller (not shown) controls the inverter 11 to determine the difference between the torque obtained by multiplying the torque generated by the internal combustion engine (constant value) by the reduction ratio of the transmission 3 and the torque required for traveling. And generated by the electric motor 5.

As described above, according to the first embodiment of the present invention, in the drive system including the internal combustion engine, the continuously variable transmission using the planetary cone friction wheel, and the electric motor, the internal combustion engine It is possible to keep the generated torque and the number of revolutions of the constant. Moreover, a hybrid vehicle with low fuel consumption and low emissions can be manufactured with a simple configuration in which the internal combustion engine and the drive shaft are mechanically connected.

In the first embodiment, the internal combustion engine 1
The generated torque of the
It may be variable depending on the charging state of the battery. The point is that the torque of the internal combustion engine 1 does not follow the running state of the hybrid vehicle in real time, but may be controlled so as to reach a predetermined value set in advance depending on the conditions.

Next, the structure of the transmission used in the second embodiment of the present invention will be described with reference to FIGS. In the first embodiment, the transmission 3 that uses a continuously variable transmission that uses a planetary conical friction wheel is used, but in the second embodiment, a transmission 31 that applies a continuously variable transmission that uses a so-called variable pitch pulley. Is used. In the second embodiment, the output shaft 2 of the internal combustion engine 1 shown in FIG.
Is connected to an input shaft 36 which is arranged in the housing 32 of the transmission 31 and is integrated with the one cone portion 33 and the cup portion 35. An input shaft 36 penetrates the center of a piston 38 that is integral with the other cone portion 37 that faces one cone portion 33, and the piston 38 is slidable in the axial direction within a cylindrical cup portion 35. In addition, the key 40, which is inserted in a liquid-tight manner and is installed on the input shaft 36, rotates integrally with the input shaft 36 in the rotation direction. An input side oil chamber 34 is formed between the piston 38 and the cup portion 35 and is filled with oil.
In this way, the cone portion 33 on one side and the cone portion 37 on the other side constitute the variable pitch pulley 48 on the input side.

The output shaft 6 of the electric motor 5 (see FIG. 1) is connected to the output shaft 43 arranged in the housing 32 of the transmission 31. One cone portion 41 and the cup portion 42 are integrated with the output shaft 43, and the piston 46 and the flange 47 are integrated with the other cone portion 45 facing the one cone portion 41. The output shaft 43 passes through the center of the piston 46 and the flange 47. The piston 46 is slidably inserted in the cup portion 42 in the axial direction, and the key 44 is installed on the output shaft 43.
Thus, the output shaft 43 rotates integrally with the output shaft 43 in the rotating direction. A partition plate 50 is provided in the cup portion 42, and an output side oil chamber 49 is formed between the piston 46 and the partition plate 50 to fill with oil. Also,
A spring 51 is arranged between the bottom surface of the cup portion 42 and the flange 47, and the flange 47 and the piston 46 are connected to each other as shown in FIG.
Is pressed to the left at.

As shown in FIG. 6, a plurality of, for example, four radial grooves 52 are formed on the left side surface of the flange 47 in FIG. 5 or 7, and the inside of the groove 52 and the partition plate 50 are separated from each other. A ball 53 is held between them. And the groove 52
The depth in the axial direction is deeper as it approaches the central output shaft 43, and is formed so as to be shallower as it goes away from the output shaft 43 in the radial direction. An oil passage 55 is formed at the center of the output shaft 43, and the output side oil chamber 49
Is communicated with an oil passage 57 in a part 56 attached to the side surface of the housing 32 via an oil passage 55.

On the other hand, an oil passage 58 is similarly formed in the center of the input shaft 36, and the input side oil chamber 34 communicates with the oil passage 57 in the part 56 via the oil passage 58. The one cone portion 41 and the other cone portion 45 constitute an output side variable pitch pulley 65, and a belt 60 is wound between the input side variable pitch pulley 48 and the output side variable pitch pulley 65. Has been. 5 shows the output shaft 6 of the electric motor (see FIG. 1).
7 shows a state in which the output shaft 6 is not rotating, or the output shaft 6 is not rotating. FIG. The figure shows a state of moving outward in the direction.

Next, the transmission 31 of the second embodiment of the present invention is the transmission 30 of the hybrid vehicle shown in FIG.
The operation when it is used instead of is explained. As shown in FIG. 5, when the rotation speed of the output shaft 43 of the transmission 31 connected to the output shaft 6 of the electric motor is low, the ball 5
Since the centrifugal force acting on 3 is small, the ball 53 is in the vicinity of the output shaft 43, and the piston 46 is the spring 5
It is pressed by 1 and moves to the left side in FIG. As a result, a part of the oil in the input side oil chamber 34 moves to the enlarged output side oil chamber 49 via the oil passage 58, the oil passage 57, and the oil passage 55, so that the piston 38 on the input shaft 36 side is 5 Move to the right side. Therefore, one cone portion 33 that constitutes the variable pitch pulley 48 on the input side
While the distance between the other cone portion 37 and the other cone portion 37 is widened, the distance between the one cone portion 41 and the other cone portion 45 which configure the variable pitch pulley 65 on the output side is narrowed. As a result, the effective radius of the variable pitch pulley 48 on the input side, around which the belt 60 is wound, becomes smaller, and the effective radius of the variable pitch pulley 65 on the output side becomes larger.
The reduction ratio of is increased.

On the contrary, when the rotation speed of the output shaft 6 of the electric motor, and thus the output shaft 43 of the transmission 31, increases, the balls 60 are subjected to a large centrifugal force to form the inclined grooves 52, as shown in FIG. Move radially outward along. As a result, the piston 46 on the output shaft 43 side moves to the right side in FIG.
Contrary to the case where the rotation speed is low, the effective radius of the variable pitch pulley 65 on the output side on which the belt 60 is wound becomes smaller and the effective radius of the variable pitch pulley 48 on the input side becomes larger. The ratio (reduction ratio) becomes smaller.

As described above, the transmission 31 of the second embodiment
, The output shaft 6 of the electric motor 5 (that is, the output shaft 4
When the rotation speed of 3) is low, the reduction ratio is large, and conversely, when the rotation speed of the output shaft 6 is high, the reduction ratio is small. Therefore, the rotation speed of the input shaft 36 to which the internal combustion engine is connected is controlled to be constant. can do.

That is, since the transmission 31 can automatically change the gear ratio in accordance with the change in the rotational speed of the output shaft 6 of the electric motor and the output shaft 43 connected thereto, the internal combustion engine 1 is connected. The rotational speed of the input shaft 36 can be controlled to be constant.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an overall configuration of a first embodiment and a second embodiment of the present invention.

FIG. 2 is a sectional view showing a state in which the rotation speed of the output shaft of the transmission used in the first embodiment of the present invention is low.

3 is a side view of a main part of the transmission shown in FIG.

FIG. 4 is a cross-sectional view showing a state where the output shaft of the transmission used in the first embodiment has a high rotation speed.

FIG. 5 is a cross-sectional view showing a state in which the rotation speed of the output shaft of the transmission used in the second embodiment of the present invention is low.

6 is a side view of a portion of the transmission shown in FIG.

FIG. 7 is a cross-sectional view showing a state where the output shaft of the transmission used in the second embodiment has a high rotation speed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Heat engine (internal combustion engine) 3 ... Transmission (1st Embodiment) 5 ... Electric motor 6 ... Output shaft 7 ... Drive shaft 10 ... Drive wheel 11 ... Inverter 12 ... Battery 13 ... Bevel gear 15 ... Planetary cone 16 ... Another bevel gear 17 ... Carrier 18 ... Cone 20 ... Slide ring 21 ... Annular protrusion 22 ... Rotation stop pin 27 ... Groove 30 ... Ball 31 ... Transmission (second embodiment) 33, 41 ... One Cone part 34 ... Input shaft side oil chamber 35, 42 ... Cup part 36 ... Input shaft 37, 45 ... Other cone part 38, 46 ... Piston 43 ... Output shaft 47 ... Flange 48 ... Input shaft side variable pitch pulley 49 ... Oil chamber 50 on output shaft side ... Partition plate 51 ... Spring 52 ... Inclined groove 53 ... Ball 60 ... Belt 65 ... Variable pitch pulley on output shaft side

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B60L 15/20 B60K 9/00 Z F16H 15/52

Claims (5)

[Claims] 1. A drive shaft having a heat engine for converting heat energy into a driving force and an electric motor for converting electric energy into a driving force, the drive shaft connecting an output shaft of the heat engine and driving wheels of a vehicle. In a hybrid vehicle in which the electric motor is arranged in the middle part and drive wheels are driven using the heat engine and the electric motor, between the output shaft of the heat engine and the output shaft of the electric motor, A transmission that automatically changes the gear ratio according to the number of revolutions of the output shaft of the electric motor, and the transmission controls the number of revolutions of the output shaft of the heat engine to be constant. Hybrid vehicle characterized by. 2. The output torque of the heat engine is kept constant, and it corresponds to the difference between the output torque of the transmission that changes depending on the gear ratio of the transmission and the drive torque of the drive shaft connected to the drive wheels. The hybrid vehicle according to claim 1, further comprising a control unit that causes the electric motor to generate an amount of torque to be controlled. 3. The hybrid vehicle according to claim 1, wherein the gear ratio of the transmission is automatically controlled according to the centrifugal force generated by the rotation of the output shaft of the transmission. 4. The transmission comprises a continuously variable transmission using a planetary cone friction wheel, and a slide ring for shifting is slid on a cone member in accordance with a centrifugal force generated on an output shaft of the transmission. The hybrid vehicle according to claim 3, further comprising a mechanism. 5. The transmission is provided with variable pitch pulleys on an input shaft and an output shaft, a transmission in which a belt is wound between the variable pitch pulleys, and a centrifugal force generated on an output shaft of the transmission. 4. A mechanism for changing the pitch of the pulleys according to the force is added.
The described hybrid vehicle.