JPH11198670A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure driving power, improve recovery efficiency of power energy with two motors of relatively low output, and optimize engine and motor control according to running conditions. SOLUTION: The ring gear 3c of a planetary gear unit 3 is connected to an engine 1 through a motor 2, a carrier 3b is connected to the input shaft 5a of a belt-type continuously variable transmission(CVT) 5 with a motor 4 linked with a sun gear 3a, and the sun gear 3a and the carrier 3b are linked by a clutch 6 so as to be combined freely. A dirigible road wheel 10 is formed continuously at the output shaft 5c of the CVT 5 through a reduction gear train 7, a differential mechanism 8, and a driving shaft 9. It is thus possible to ensure driving power by the two small type motors 2, 4 of relatively low output, improve the recovery efficiency of power energy, attain optimum control according to running conditions by fixing differential of the planetary gear unit 3 under a condition of high speed running or the like by the clutch 6, and control of the engine 1 and the motors 2, 4 in an optimum condition by controlling the change gear ratio of the CVT 5 properly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle using both an engine and a motor, and more particularly, to a hybrid vehicle using two relatively low-output motors to secure a driving force and improve the efficiency of power energy recovery. About the car.

[0002]

2. Description of the Related Art In recent years, hybrid vehicles that use both an engine and a motor have been developed for vehicles such as automobiles from the viewpoint of low pollution and resource saving. 2. Description of the Related Art There are many techniques for mounting two motors to improve the efficiency of recovering motive energy and secure traveling performance.

For example, Japanese Patent Application Laid-Open No. 9-46821 discloses that the power of an engine is distributed to a generator and a motor (drive motor) by using a power distribution mechanism based on a differential distribution mechanism such as a differential gear. A hybrid vehicle that runs by driving a motor while generating power with a part of the power is disclosed. Japanese Patent Application Laid-Open No. 9-100853 discloses that a motive power of an engine is generated by a planetary gear and a generator (motor). And a hybrid vehicle that distributes the vehicle to the public.

[0004]

However, in each of the above-mentioned prior arts, most of the driving force at low speed depends on the driving motor, so that a large-capacity large motor is required for driving. However, since the amplifying function for the torque required by the drive wheels depends on the electric power, a generator having a power generation capacity capable of maintaining a constant running performance even when the battery capacity is not sufficient is required. It becomes a factor of cost increase.

[0005] Further, in a vehicle, the output shaft rotation speed is changed so as to exceed the rotation control range of the motor (generator). Therefore, merely distributing the engine output to the generator and the driving motor causes a problem from the driving wheels. It is not always possible to sufficiently optimize the control of the engine and the motor for the required driving force.

[0006] In a hybrid vehicle, the smaller the shared torque of each motor, the less the effect of the required conversion efficiency between torque and electric power can be reduced, and it is better to minimize the conversion between torque and electric power. This is preferable in improving the energy efficiency of the entire vehicle.

[0007] Further, the manner of controlling the two mounted motors differs depending on the use form of the vehicle and the running conditions of the vehicle, and it is desirable that this control be as simple as possible.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and uses two motors having excellent energy efficiency and relatively low output to secure a driving force and improve the efficiency of recovering motive energy, and to improve the driving wheels. Engine and motor control can be optimized for the required driving force from
It is an object of the present invention to provide a hybrid vehicle capable of simply controlling two motors.

[0009]

According to the first aspect of the present invention,
In a hybrid vehicle that uses both the output of an engine and the output of a motor as a traveling drive source, a planetary gear having a sun gear, a carrier that rotatably supports a pinion that meshes with the sun gear, and a ring gear that meshes with the pinion. A first motor connected between the output shaft of the engine and the ring gear of the planetary gear and used for switching as a drive source or a generator; and a first motor connected to a sun gear of the planetary gear and used for switching as a drive source or a generator. A possible second motor, a coupling mechanism that can couple any two of the sun gear, carrier and ring gear of the planetary gear, and a gear ratio that is coupled to the carrier of the planetary gear and can be switched in a plurality of stages or steplessly. Speed and torque between the planetary gears and drive wheels Characterized by comprising a power conversion mechanism for width.

According to a second aspect of the present invention, in the first aspect of the invention, the power conversion mechanism is provided between a primary pulley supported on an input shaft and a secondary pulley supported on an output shaft. And a belt type continuously variable transmission.

That is, according to the first aspect of the invention, the first motor is connected between the output shaft of the engine and the ring gear of the planetary gear, the second motor is connected to the sun gear of the planetary gear, and the sun gear of the planetary gear is further connected. Between the planetary gear and the drive wheels by connecting a power conversion mechanism capable of changing the speed ratio in a plurality of steps or steplessly to the carrier of the planetary gear so that any two of the gear and the carrier and the ring gear can be freely coupled by a coupling mechanism such as a clutch. To perform speed change and torque amplification.

[0012] The first and second motors are driven depending on running conditions.
At the same time, it is used as a drive source or a generator, or one is used as a drive source and the other is used as a generator, or a clutch is fixed (coupled) and one is used as a drive source or a generator and the other is used without control. be able to.

For example, when the clutch is released under running conditions, the driving force is supplied from both the engine and the first motor to the ring gear of the planetary gear, or the first driving force is generated by a part of the driving force of the engine. When the driving force is supplied from the second motor to the sun gear of the planetary gear by operating the motor as a generator and supplying the remaining driving force to the ring gear of the planetary gear, the respective driving forces are combined by the planetary gear, and The output is transmitted to the drive wheels via the power conversion mechanism. Also, at the time of deceleration or braking, the driving force returned from the driving wheel side to the planetary gear carrier via the power conversion mechanism is connected to the first motor and the engine side connected to the ring gear and to the sun gear. To the second motor side,
The motor can be used as a generator to recover motive energy, or the second motor can be used as a generator to supply electric power to the first motor to generate driving force with the engine and the first motor.

Further, under running conditions such as high-speed running, the drive shaft from the engine in which two motors are arranged between the engine and the power conversion mechanism can be formed by fixing the differential of the planetary gear by the clutch. Both of the second motors are operated as a drive source or a generator, or one is a drive source or a generator and the other is in a state without control.

Here, as the power conversion mechanism, a drive belt is wound between a primary pulley supported on the input shaft and a secondary pulley supported on the output shaft. It is desirable to perform speed change and torque amplification by using a belt-type continuously variable transmission and changing the speed ratio steplessly.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 relate to an embodiment of the present invention, FIG. 1 is an explanatory diagram showing a basic configuration of a drive system, and FIG. 2 is a diagram showing a case where the vehicle is driven by an engine and first and second motors in a clutch released state. FIG. 3 is an explanatory diagram showing the flow of torque and electricity, FIG. 3 is an explanatory diagram showing the flow of torque and electricity when the first motor is used as a generator in a clutch released state, and FIG. FIG. 5 is an explanatory view showing the torque and the flow of electricity when the second motor is used as a generator, and FIG. 5 shows the case where the second motor is used as a generator in a clutch disengaged state and the first motor generates driving force. FIG. 6 is an explanatory diagram showing the flow of torque and electricity, FIG. 6 is an explanatory diagram showing the flow of torque and electricity when the vehicle is driven by the engine and the first and second motors in a clutch fixed state,
FIG. 7 is an explanatory diagram showing a torque and an electric flow when the first and second motors are used as a generator in a clutch fixed state, and FIG. 8 shows a torque and an electric flow when the vehicle moves backward in a clutch disengaged state. FIG.

The hybrid vehicle according to the present invention is a parallel hybrid vehicle that uses both an engine and a motor. As shown in FIG. 1, a first vehicle that is responsible for starting up the engine 1 and for generating and power assisting the engine 1 is provided. A motor 2 (hereinafter simply referred to as a motor 2) and an output shaft 1a of the engine 1
And a function of the planetary gear unit 3 connected via the motor 2 to the
A second motor 4 (hereinafter, simply referred to as a motor 4) that serves as a driving force source for starting and reversing and that collects deceleration energy, and a power conversion that performs a power conversion function during traveling by performing gear shifting and torque amplification. A drive system having the mechanism 5 as a basic configuration is provided.

The planetary gear unit 3 is a single pinion type planetary gear having a sun gear 3a, a carrier 3b rotatably supporting a pinion meshing with the sun gear 3a, and a ring gear 3c meshing with the pinion.

Further, the planetary gear unit 3 includes:
In the embodiment of the present invention, among the sun gear 3a, the carrier 3b, and the ring gear 3c, in the embodiment of the present invention, the sun gear 3a and the carrier 3b are formed to be freely connectable by a clutch 6 as a coupling mechanism.

As the power conversion mechanism 5, it is possible to use a transmission combining a gear train, a transmission using a fluid torque converter, or the like. The primary pulley 5b supported by the input shaft 5a and the output It is desirable to employ a belt-type continuously variable transmission (CVT) in which a driving belt 5e is wound around a secondary pulley 5d supported by a shaft 5c. In the present embodiment, the power conversion mechanism will be described below. 5
Will be described as CVT5.

That is, in the drive system of the hybrid vehicle in the present embodiment, the planetary gear unit 3 is disposed between the output shaft 1a of the engine 1 and the input shaft 5a of the CVT 5, and the ring gear 3 of the planetary gear unit 3
c is coupled to the output shaft 1a of the engine 1 via one motor 2, the carrier 3b is coupled to the input shaft 5a of the CVT 5, the other motor 4 is coupled to the sun gear 3a, and the planetary gear unit 3 Sun gear 3
a and the carrier 3b can be freely connected by the clutch 6. A differential mechanism 8 is connected to an output shaft 5c of the CVT 5 via a reduction gear train 7, and a drive wheel 10 for a front wheel or a rear wheel is connected to the differential mechanism 8 via a drive shaft 9.

The engine 1, the two motors 2,
4, CVT 5, clutch 6, monitoring and control system 11
Centrally controlled by This monitoring and control system 11
Includes a driver's will determination system 12, which detects a depression operation of an accelerator pedal or a brake pedal, a steering angle of a steering, and the like to determine a driver's driving operation status, a brake operation state, an engine 1, an ABS (anti-skid brake system), and the like. The vehicle control status determination system 13 determines the control status of the vehicle from various control amounts for the vehicle, the operating status of auxiliary equipment such as lights and air conditioners, and the current vehicle running status such as vehicle speed, uphill and downhill, and road surface conditions. Is connected, and monitors the operating state of the engine 1, the two motors 2, 4, the CVT 5, the clutch 6, and the state of the battery 15, and based on information from each system, Control of the engine 1, the inverter 16,
17, the drive of the motors 2 and 4 and the charge control of the battery, the control of the gear ratio and supply hydraulic pressure of the CVT 5, the clutch 6
Release, fixed control, etc.

In the drive system having the above configuration, as described above, the engine 1 and the motor 2 are connected to the ring gear 3c of the planetary gear unit 3 and the sun gear 3a
The motor 4 is connected to the motor 3 so as to obtain an output from the carrier 3b. Further, the output from the carrier 3b is transmitted to the drive wheels 10 by shifting and amplifying the torque by the CVT 5 and transmitted to the driving wheels 10. Can be used for both power generation and driving force supply, and a relatively low-power motor can be used.

That is, when the clutch 6 is released,
When the ring gear 3c is driven by one or both of the engine 1 and the motor 2, for example, when the ring gear 3c is driven by the engine 1 and the motor 2 as shown in FIG. Electric energy is supplied to the motors 2 and 4 via the motors 16 and 17, is converted into driving force by the motor 2, is added to the driving force from the engine 1, becomes an input torque Tr to the ring gear 3 c, and is driven by the motor 4. Is converted into the input torque Ts to the sun gear 3a. From the input / output characteristics of the planetary gear, the input torque Ts to the sun gear 3a, the input torque Tr to the ring gear 3c, and the output torque Tc of the carrier 3b are as follows. (1) is obtained. Tc = Ts + Tr (1)

Therefore, the input torque Ts to the sun gear 3a and the input torque Tr to the ring gear 3c are combined by the planetary gear unit 3 and output from the carrier 3b.
Even when the output torque of each of the engine 1 and the motors 2 and 4 is small, a large torque can be obtained from the carrier 3b and transmitted to the drive wheels 10 via the CVT 5 to obtain a large vehicle driving force. . In FIG. 2 and FIGS. 3 to 8 described below, the two-dot chain line schematically shows the flow of electricity, and the one-dot chain line schematically shows the flow of torque transmission.

In this case, the input torque Ts of the sun gear 3a
The input torque Tr of the ring gear 3c and the input torque Tr of the ring gear 3c must receive a reaction force from each other in order to be combined and become the output torque Tc of the carrier 3b.
The relationship between Tr and the number of teeth Zs of the sun gear 3a, the ring gear 3
gear ratio i (i = Zs / Z) represented by the number of teeth Zr
From the relationship shown in the following equations (2) and (3) expressed using r), the following equation (4) must be satisfied. Tc · i / (1 + i) = Ts (2) Tc · 1 / (1 + i) = Tr (3) Ts = i · Tr (4)

Generally, because of the structure of the planetary gear, Zs
<Zr, the gear ratio i is i <1.
As is clear from the equation, the input torque T to the sun gear 3a
s is i times the input torque Tr to the ring gear 3c.

That is, since the engine 1 and the motor 2 are connected to the ring gear 3c and the motor 4 is connected to the sun gear 3a, the input torque Ts to the sun gear 3a can be achieved with a small value (i · Tr). Has become.

However, since the input torque Ts to the sun gear 3a is obtained only by the motor 4, the battery 1
If power is required to be supplied from the motor 5 to the motor 4 and a shortage of charge of the battery 15 is predicted during a long running, the motor 2 is used as a generator.

As described above, by driving the motor 2 as a generator with a part of the driving force of the engine 1 and suppressing the remaining driving force as the input torque to the ring gear 3c, the input torque to the ring gear 3c is reduced. As shown in FIG. 3, the power required for the motor 4 can be reduced, and the motor 4 can be driven without using the electricity charged in the battery 15 with the power obtained by the power generation of the motor 2. In this case, the motor 4 is mainly used for sharing the reaction force of the sun gear 3a, and the vehicle can travel only by the driving force of the engine 1.

Here, since the engine 1 and the motor 2 are connected to the ring gear 3c and the motor 4 is connected to the sun gear 3a, the input torque Ts to the sun gear 3a can be suppressed to a small value. Since the required driving force is relatively small, only a small amount of electric energy is required to obtain the driving force, so that it is possible to reduce the effects of the torque and power conversion efficiency of the motor 4 and the control efficiency of the inverter. is there.

In such a situation, when the battery 15 needs to be charged, control is performed so that the amount of power generated by the motor 2 becomes larger than the required power of the motor 4. Also, while traveling mainly with the driving force of the engine 1, the load on the output of the engine 1 increases due to climbing a hill, sudden acceleration, and the like,
When it is necessary to increase the assisting force of the motor 4, the amount of power generated by the motor 2 is suppressed to increase the input torque from the engine 1 to the ring gear 3 c, and at the same time, the battery is driven so that the driving force of the motor 4 increases. By supplying power from the power supply 15, a necessary driving force can be secured.

When the clutch 6 is released during deceleration or braking, the torque Tc transmitted from the drive wheels 10 to the carrier 3b of the planetary gear unit 3 via the CVT 5 as shown in FIG. 2, the torque Tr from the ring gear 3c to the motor 4, and the sun gear 3 to the motor 4.
The electric power is distributed to the torque Ts from a and is converted into electric energy by the motors 2 and 4 to charge the battery 15. For this reason, in a situation in which braking is performed by the power generation of the motors 2 and 4, the load on each motor 2 and 4 is reduced while the load on each motor 2 and 4 is reduced despite the amount of power generation per motor and the resulting braking force. As a whole, a large amount of power generation and braking force can be obtained, and the efficiency of power energy recovery can be greatly improved.

Also in this case, when the battery 15 is sufficiently charged and the battery 15 does not need to be charged, as shown in FIG. By causing the motor 4 to generate electric power for this purpose, a sufficient engine braking force can be obtained without charging the battery 15. Further, when the battery 15 needs to be charged, the battery 4 is controlled so as to reduce the power supplied to the motor 2 while keeping the power generation amount of the motor 4 as it is, so that the battery 15 can be charged without lowering the engine braking performance. 15 can be charged.

Under the condition that the engine 1 runs at the maximum output and the vehicle runs only by the driving force of the engine 1, it is necessary to control the rotation speed and the torque of the motor 2 and the motor 4 as well. FIG. 3 or FIG.
As described in, if one of the two motors 2 and 4 is used for power generation and the other is used for driving force, one motor converts torque to electric power, and the other motor converts electric power to torque. To obtain the required torque or electric power, which is greatly affected by these conversion efficiencies and the like, resulting in a large decrease in the overall energy efficiency. Also,
To control the two motors 2 and 4 separately, complicated control specifications are required.

For this reason, in the present embodiment, the clutch 6 is controlled from the disengaged state to the fixed state according to the running conditions as described above, and the sun gear 3a of the planetary gear unit 3 and the carrier 3b are connected by the clutch 6, and the two A drive shaft directly connected to the engine from the engine 1 to the CVT 5 in which the two motors 2 and 4 are arranged can be formed.

That is, when the driving force is to be obtained with the clutch 6 fixed, the relationship between the output torques of the engine 1, motor 2 or motor 4 is controlled as described with reference to FIGS. 6, it is possible to arbitrarily generate a necessary driving torque on the driving wheel 10 side of the engine 1, the motor 2 or the motor 4 as shown in FIG. In comparison with the case where two motors 2 and 4 must be controlled so that only one of the motors 2 and 4 generates a driving force, the electric power passing through the motors 2 and 4 and the inverters 16 and 17 and the power line is reduced. Minimizing allows for efficient use of charged electrical energy. When the driving force is generated by the engine 1, the motor 2, and the motor 4, the driving torque of each of the motor 2 and the motor 4 is combined by the fixed planetary gear unit 3. Is the same as Motor 2,
If no driving force is generated in the vehicle 4, a driving system similar to that of a normal vehicle with only an engine is obtained. Thereby, it is possible to prevent a loss in energy conversion due to the power generation and driving of each of the motors 2 and 4 in the case of FIG. 3 and an increase in the required driving force of the engine 1 to compensate for the loss.

Similarly, when the clutch 6 is fixed and the input torque from the carrier 3b of the planetary gear unit 3 is braked by the power generation of the motors 2 and 4 and the engine brake, the same applies to FIGS. As described, without controlling the relationship between the respective braking torques of the engine 1, the motor 2 or the motor 4, as shown in FIG.
It is possible to arbitrarily control the brake control by the power generation of each of the motor 2 and the motor 4 as necessary,
Simplification of the control specifications and, for example, generation of power by only one of the motors 2 and 4, compared to the case where the two motors 2 and 4 must be controlled to generate power,
4. By minimizing the power passing through the inverters 16 and 17 and the power line, it becomes possible to use electric energy at the time of power generation. Since the braking torque of each of the motor 2 and the motor 4 is divided by the fixed planetary gear unit 3, the maximum braking torque is the same as that in FIG. If no braking force is generated on the motors 2 and 4,
The drive system is the same as that of a normal engine-only vehicle.

As described above, according to the running conditions, the clutch 6
By controlling the sun gear 3a and the carrier 3b of the planetary gear unit 3 by the
It is possible to perform a control for arbitrarily generating a necessary driving torque or braking torque without controlling the relationship between the output torque or the braking torque of each of the two motors 2 and 4,
This makes it possible to simplify control specifications and effectively use electric energy.

Further, when the vehicle is moving backward, the engine generally rotates in the same direction as when the vehicle is moving forward, so that the motor 2 directly connected to the engine 1 is rotated so that the engine 1 does not rotate in the reverse direction. The direction is controlled, and the driving force of the motor 4 is output to the carrier 3b to move backward. In this case, as shown in FIG.
It is possible to reverse while traveling without charging the battery 15 and charging the battery 15 by power generation of the motor 2.

That is, when the charge amount of the battery 15 is sufficient, the output of the engine 1 is absorbed to operate the motor 2 as a generator, and the generated power is transferred to the motor 4.
Control to supply to On the other hand, when the charged amount of the battery 15 is insufficient, the output of the engine 1 is increased to control the amount of power generated by the motor 2 to be larger than the required power of the motor 4, and the generated power is used to control the battery 15. Charge.

When the charge amount of the battery 15 is sufficient, power is supplied to the motors 2 and 4 while the engine is stopped.
By fixing the ring gear 3c by the motor 2 and supplying a driving force from the motor 4 to the carrier 3b, the vehicle can be moved backward.

The rotation of the engine 1 and the motors 2 and 4 via the planetary gear unit 3 is appropriately controlled by using the CVT 5, and the rotation of the engine 1 and the motors 2 and 4 is controlled.
4 can be optimized and the driving force required by the drive shaft can be secured.

That is, when the clutch 6 is released, in the planetary gear, the rotational speed of the sun gear 3a is set to N.
s, the rotation speed of the ring gear 3c is Nr, and the rotation speed of the carrier 3b is Nc, the respective rotation speeds have a relationship expressed by the following equation (5), and the rotation speed Ns of the sun gear 3a and the rotation speed Nr of the ring gear 3c are By controlling, the rotation speed Nc of the carrier 3b can be set freely. In addition, Ns =
In the case of Nr, Nc = Nr = Ns, and all input / output rotational speeds match. (1 + i) · Nc = Nr + i · Ns (5)

Therefore, as described above, the relationship between the input and output torques of the planetary gears is determined by the gear ratio i. Therefore, even when the clutch 6 is released, the relationship between the torques of the respective gears is maintained and the rotation of the motors 2 and 4 is maintained. By controlling the number of rotations, it is possible to control the output rotation speed. However, if one of the motors 2 and 4 is kept at a fixed rotation speed and the output rotation speed is to be increased, the rotation speed of one motor will be reduced. It must be higher than the required output speed.

For example, when the rotation speed of the sun gear 3a driven by the motor 4 is fixed and the rotation speeds of the ring gear 3c and the carrier 3b with respect to the sun gear 3a are considered, this case is the same as the case where the sun gear 3a is fixed. Since Ns = 0 can be set in the above equation (5), the rotation speed of the ring gear 3c driven by the motor 2 (difference in rotation speed with respect to the sun gear 3a) is equal to the rotation speed of the carrier 3b (similarly, with respect to the sun gear 3a). (Rotational speed difference) (1 + i) times.

Further, when the rotation speed of the ring gear 3c driven by the motor 2 is fixed and the rotation speeds of the sun gear 3a and the carrier 3b with respect to the ring gear 3c are considered, it is the same as the case where the ring gear 3c is fixed. In the above equation (5), Nr = 0 can be set, and the rotation speed of the sun gear 3a driven by the motor 4 (the rotation speed difference with respect to the ring gear 3c) is equal to the rotation speed of the carrier 3b (similarly, the rotation speed difference with respect to the ring gear 3c). ) (1 + i) / i times.

In any case, in either case, if one of the motor 4 for driving the sun gear 3a and the motor 2 for driving the ring gear 3c is kept at a constant rotational speed and the output rotational speed (carrier rotational speed) is to be increased, One of the motors 2 and 4 becomes higher than the output rotation speed (carrier rotation speed).

Since an increase in the number of rotations of the motor leads to a decrease in efficiency and reliability, it is usually necessary to use the planetary gears in such a manner that the difference in rotation between the gears in the planetary gears is reduced and to reduce the number of rotations of the motor. However, when the vehicle speed is low, the sun gear 3a or the ring gear 3c
By relatively increasing the rotation speed of either of the above, it is possible to stop the rotation of the other, or to reverse the output shaft rotation speed while the engine is running, but reverse When this happens, the output shaft speed will increase,
Even if an attempt is made to reduce the rotation speed difference between the two motors 2 and 4, the rotation speeds of the engine 1 and the motors 2 and 4 will eventually increase. For this reason, under such running conditions, the differential in the planetary gear is fixed by the clutch 6 and the rotational speeds of the two motors 2 and 4 are kept low.

Originally, it is desirable that the engine be used in a rotational speed range where combustion efficiency is high and exhaust gas purification can be expected. On the other hand, in a vehicle, the output shaft rotation exceeding the rotation control range of the motor is required. There are number changes. Therefore,
By appropriately controlling the speed ratio of the CVT 5 disposed on the output shaft of the planetary gear unit 3 with respect to the required driving force from the driving wheels 10, the input torque to the planetary gear unit 3 can be suppressed low. Can be appropriately controlled.

In other words, the CVT 5 is used to optimize the engine performance by limiting the use conditions of the engine 1 and the motors 2 and 4 to the optimum range with respect to the required change in the number of rotations of the drive shaft and the driving force of the vehicle. The frequency of using the engine 1 in a region where the exhaust gas emission is high and the exhaust gas emission is low can be greatly increased, and the fuel consumption can be improved and the pollution can be reduced while securing the traveling performance.

[0052]

As described above, according to the first aspect of the present invention, the first motor which can be switched and used as a drive source or a generator is connected between the output shaft of the engine and the ring gear of the planetary gear. At the same time, the sun gear of the planetary gear is connected to a second motor that can be switched and used as a drive source or a generator, and further, the sun gear of the planetary gear and any two of the carrier and the ring gear are freely connectable by a connection mechanism. When the coupling mechanism is released to connect the power conversion mechanism that can change the gear ratio steplessly or steplessly and perform gear shifting and torque amplification between the planetary gears and the drive wheels,
A driving force supplied from one or both of the engine and the first motor and a driving force supplied from the second motor are combined and output by a planetary gear, and the driving force is supplied from a driving wheel side via a power conversion mechanism. The driving force transmitted in reverse is distributed to the first motor and the second motor by the planetary gear, and the first and second motors convert the power energy into electric energy and recover the electric power, or the second motor , And power is supplied to the first motor to generate a braking force by the engine and the first motor. Therefore, a small, relatively low-power 2
With two motors, it is possible to secure the driving force and improve the efficiency of recovering the motive energy, so that the system cost can be reduced, and the size and weight can be reduced. Further, since the engine and the first motor are connected to the ring gear of the planetary gear, and the second motor is connected to the sun gear of the planetary gear, the shared torque of the second motor can be reduced. It is possible to reduce the influence of the conversion efficiency and the like required between the electric powers and improve the energy efficiency of the entire vehicle. Furthermore, the first motor or the second motor
Under running conditions such as an increase in the number of revolutions of the motor, the drive shaft from the engine in which the two motors are arranged between the engine and the power conversion mechanism by fixing the planetary gear differential by the coupling mechanism can be formed. The first and second motors are both operated as a drive source or a generator, or one is a drive source or a generator, and the other is in a state without control, so that the control specifications can be simplified. The difference between the rotation speeds of the connected first and second motors is prevented from increasing, and the reliability is excellent, and the conversion between torque and power is minimized, and the energy efficiency can be greatly improved. In addition, by appropriately controlling the speed ratio of the power conversion mechanism disposed on the output shaft of the planetary gear, it becomes possible to optimally control the engine and the first and second motors.

According to the second aspect of the present invention, the first aspect is provided.
In order to perform speed change and torque amplification by changing the gear ratio steplessly with the power conversion mechanism described as a belt type continuously variable transmission, the input / output torque to the planetary gear and the rotational speed for the required driving force from the drive wheels are adjusted. Control can be performed freely, and control of the engine and the first and second motors can be further optimized.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a basic configuration of a drive system.

FIG. 2 is an explanatory diagram showing the flow of torque and electricity when the vehicle is driven by an engine and first and second motors in a clutch disengaged state.

FIG. 3 is an explanatory diagram showing a flow of torque and electricity when the first motor is used as a generator in a clutch disengaged state.

FIG. 4 is an explanatory diagram showing the flow of torque and electricity when the first and second motors are used as generators in a clutch disengaged state.

FIG. 5 is an explanatory diagram showing a flow of torque and electricity when a second motor is used as a generator in a clutch disengaged state and a driving force is generated by the first motor.

FIG. 6 is an explanatory diagram showing a flow of torque and electricity when the vehicle is driven by an engine and first and second motors in a clutch fixed state.

FIG. 7 is an explanatory diagram showing the flow of torque and electricity when the first and second motors are used as generators in a clutch fixed state.

FIG. 8 is an explanatory diagram showing the flow of torque and electricity when the vehicle moves backward in the clutch disengaged state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... 1st motor 3 ... Planetary gear unit 3a ... Sun gear 3b ... Carrier 3c ... Ring gear 4 ... 2nd motor 5 ... Belt type continuously variable transmission (power conversion mechanism) 6 ... Clutch (coupling mechanism)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16H 3/44 F16H 3/44 Z

Claims (2)

[Claims] 1. A hybrid vehicle that uses an output of an engine and an output of a motor in combination as a traveling drive source, a sun gear, a carrier that rotatably supports a pinion that meshes with the sun gear, and a ring gear that meshes with the pinion. A first motor that is connected between the output shaft of the engine and the ring gear of the planetary gear and that can be switched as a drive source or a generator, and that is connected to a sun gear of the planetary gear; A second motor that can be switched as a generator, a coupling mechanism that can couple any two of a sun gear, a carrier, and a ring gear of the planetary gear; a coupling mechanism that is coupled to the carrier of the planetary gear and can be switched in a plurality of stages or steplessly Between the planetary gears and drive wheels according to the Hybrid vehicle, characterized in that a power conversion mechanism for performing shift and torque amplification. 2. The power conversion mechanism is a belt-type continuously variable transmission in which a drive belt is wound between a primary pulley supported on an input shaft and a secondary pulley supported on an output shaft. The hybrid vehicle according to claim 1, wherein: