JPH09117010A - Hybrid vehicle - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To improve power efficiency of a hybrid vehicle and drive efficiency of an engine. An engine 11, a generator 16, and an output shaft 1
4 is connected via the planetary gear unit 13 and the torque of the electric motor 25 is output to the output shaft 14, the engine rotation speed control means controls the rotation speed so that the engine 11 is driven in the maximum efficiency region. The generator control means adjusts the charge amount of the battery by driving the generator 16 as a generator to store electric power or by driving it as a motor to consume electric power according to the traveling state. As a result, the engine 11 can be driven in a high efficiency region, and the power efficiency is improved without causing the battery to be overcharged or insufficiently charged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle having an output shaft to which an electric motor is connected and a drive system in which an engine and a generator are connected via a differential gear device. The present invention relates to a hybrid vehicle whose rotation speed can be controlled even when the motor is a motor.

[0002]

2. Description of the Related Art Conventionally, a hybrid vehicle having a drive device using both an engine and a motor has been provided in order to achieve low pollution and low fuel consumption. Various hybrid vehicles of this type are provided, for example, the rotation generated by driving an engine is transmitted to a generator to drive the generator, and the electric power obtained by the generator is sent to a battery. Series (series) type hybrid vehicle in which the drive motor is driven by the electric power of the battery, and the drive power of the engine and the drive motor is transmitted to the output shaft to drive the vehicle to drive the drive motor. There is a parallel type hybrid vehicle that controls the output of to accelerate and decelerate.

In the above-mentioned parallel type hybrid vehicle, a hybrid vehicle having a structure in which an engine, a generator and a drive output shaft are connected through a differential gear unit and a drive motor is connected to the drive output shaft is proposed. (US Pat. No. 3,566,717). A part of the engine output drives the generator, and the regenerated electric power is supplied to the battery.

[0004]

On the other hand, in the parallel type hybrid vehicle having the differential gear device,
There are the following problems. The battery is charged by the power generated from the generator and the regenerative power from the drive motor during braking, but the battery has an allowable charge amount.
If the allowable charge amount of the battery is exceeded, overcharge may occur and sufficient regenerative braking may not be possible.

Further, when the accelerator pedal is turned off or the vehicle is in a braking state, control is performed to stop the engine to give priority to regeneration by the electric motor. In this vehicle, since the generator is connected to the output shaft via the differential gear device, the number of revolutions of the generator may exceed the maximum allowable number of revolutions at high speed, which may cause the generator to become uncontrollable. There is.

Further, in a high speed running state, it is necessary to raise the engine speed to some extent, and in order to obtain a sufficient engine torque for high speed running, the maximum efficiency region (a) as shown in FIG. ), The engine must be driven in an area outside the range, and it becomes difficult to achieve low fuel consumption.

An object of the present invention is to provide a hybrid vehicle having improved regeneration efficiency and improved engine driving efficiency.

[0008]

Such objects are achieved by the following inventions.

(1) An internal combustion engine, a generator whose rotation speed is controllable, a first gear element connected to the generator, a second gear element connected to an output shaft, and the internal combustion engine A differential gear device including a connected third gear element; an electric motor that rotates integrally with the output shaft;
Engine speed control means for controlling the speed of the internal combustion engine within a predetermined range, and generator control for controlling the speed of the generator according to the speed controlled by the engine speed control means. And a hybrid vehicle.

(2) The engine speed control means is
The hybrid vehicle according to (1) above, wherein the engine speed is controlled based on at least one of the remaining battery amount, the accelerator opening, and the vehicle speed.

(3) The hybrid vehicle according to (1) or (2), wherein the generator control means includes a brake that stops the rotation of the generator.

(4) The engine speed control means is
The hybrid vehicle according to (3) above, further including engagement-time rotation speed calculation means for calculating an engine rotation speed when the brake is engaged from a vehicle speed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of a hybrid vehicle of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a conceptual diagram showing a drive device for a hybrid vehicle according to a first embodiment of the present invention. In the figure, the first
On the axis, an engine 11, an engine output shaft 12 that outputs the rotation generated by driving the engine 11, and a differential gear device that shifts the rotation input through the engine output shaft 12 A planetary gear unit 13, a unit output shaft 14 that outputs rotation after shifting in the planetary gear unit 13, a first counter drive gear 15 fixed to the unit output shaft 14, and a generator mainly in a normal running state. A generator 16 that acts as the above and a transmission shaft 17 that connects the generator 16 and the planetary gear unit 13 are arranged. The unit output shaft 14 has a sleeve shape and is disposed so as to surround the engine output shaft 12. Also, the first
The counter drive gear 15 is arranged closer to the engine 11 than the planetary gear unit 13.

The planetary gear unit 13 includes a sun gear S which is a first gear element, a pinion P which meshes with the sun gear S, a ring gear R which is a second gear element which meshes with the pinion P, and a pinion P which are rotatable. And a carrier CR that is a third gear element that is supported by the carrier CR. The sun gear S is connected to the generator 16 via the transmission shaft 17,
The ring gear R is connected to the first counter drive gear 15 via the unit output shaft 14, and the carrier CR is connected to the engine 11 via the engine output shaft 12.

Further, the generator 16 is fixed to the transmission shaft 17, and is rotatably arranged on the rotor 21, and the rotor 21.
And a coil 23 wound around the stator 22. The generator 16 is
Electric power is generated by the rotation transmitted via the transmission shaft 17. The coil 23 is connected to a battery 19 which is a power storage unit shown in FIG. 2 and supplies electric power to the battery 19 to charge the battery 19.

The generator 16 has the other end of the transmission shaft 17,
A brake 28 is connected, and by bringing this brake 28 into an engaged state, the rotor 21 is fixed and the generator 1
The rotation of 6 and the rotation of the sun gear S are stopped.

An electric motor 25, a motor output shaft 26 for outputting the rotation of the electric motor 25, and a second counter drive gear 27 fixed to the motor output shaft 26 are arranged on a second axis parallel to the first axis. And are arranged.

The electric motor 25 is fixed to the motor output shaft 26 and is rotatably arranged on the rotor 37, the stator 38 arranged around the rotor 37, and the stator 3.
And a coil 39 wound around 8. The electric motor 25 generates torque by the current supplied to the coil 39. Therefore, the coil 39 is provided in the battery 1
9 and is configured to be supplied with current from the battery 19. When the hybrid vehicle of the present invention is in a decelerating state, the electric motor 25 receives rotation from drive wheels (not shown) to generate regenerative electric power, and supplies the regenerative electric power to the battery 19 for charging.

In order to rotate a drive wheel (not shown) in the same direction as the rotation of the engine 11, a counter shaft 31 is arranged as a drive output shaft on a third axis parallel to the first axis and the second axis. It is set up. A counter driven gear 32 is fixed to the counter shaft 31. Further, the counter driven gear 32 and the first counter drive gear 15, and the counter driven gear 3
2 and the second counter drive gear 27 are meshed,
The rotation of the first counter drive gear 15 and the rotation of the second counter drive gear 27 are reversed and transmitted to the counter driven gear 32.

Further, a diff pinion gear 33 having a smaller number of teeth than the counter driven gear 32 is fixed to the counter shaft 31. A differential ring gear 35 is provided on a fourth axis parallel to the first axis, the second axis, and the third axis, and the differential ring gear 35 and the differential pinion gear 33 are meshed. The differential ring gear 3
5, a differential device 36 is fixed, and the rotation transmitted to the differential ring gear 35 is made differential by the differential device 36 and transmitted to drive wheels.
In the above configuration, the drive output system includes the planetary gear unit 13, the generator 16, the first counter drive gear 15, the counter driven gear 32, the second counter drive gear 27, the counter shaft 31, the differential pinion gear 33, It is composed of a differential ring gear 35 and a differential device 36.

Thus, not only the rotation generated by the engine 11 can be transmitted to the counter driven gear 32, but also the rotation generated by the electric motor 25 can be transmitted to the counter driven gear 32. The hybrid vehicle can be run in an engine drive mode that drives only 11, a motor drive mode that drives only the electric motor 25, and an engine-motor drive mode that drives the engine 11 and the electric motor 25. Further, by controlling the electric power generated in the generator 16, the rotation speed of the transmission shaft 17 can be controlled. Further, the engine 11 can be started by the generator 16. When the rotation of the generator is stopped, the brake 28 can be engaged to fix the rotor 21 of the generator 16.

Next, the control system of the hybrid vehicle of the present invention will be described in detail with reference to the block diagram of FIG. The control system of this embodiment includes a vehicle control device 41, an engine control device 42, a motor control device 43, and a generator control device 44. These control devices 41, 4
Reference numerals 2, 43, and 44 denote, for example, a CPU (central processing unit), a ROM (read-on-memory) storing various programs and data, and an RA used as a working area.
It can be constituted by a microcomputer having M (random access memory) and the like. And
The engine speed control means is constituted by the vehicle control device 41 and the engine control device 42, the generator control means is constituted by the vehicle control device 41, the generator control device 44, and the brake 28. Each is configured by the vehicle control device 41.

Further, this control system includes an accelerator sensor 45 for detecting an accelerator opening α, a vehicle speed sensor 46 for detecting a vehicle speed V, a brake sensor 47 as a deceleration operation detecting means for detecting a brake depression amount β, and A battery sensor 48 which is a charge capacity detecting means for detecting the remaining charge SOC of the battery 19 is provided. Each sensor 45,
The detection values detected by 46, 47 and 48 are the vehicle control device 4
1 is supplied. The vehicle speed sensor 46 actually detects the rotation speed of the axle and supplies the detected rotation speed to the vehicle control device 41. The vehicle control device 41 calculates the vehicle speed V based on the number of revolutions supplied from the vehicle speed sensor 46.

The vehicle control device 41 controls the entire hybrid vehicle, determines the accelerator opening α from the accelerator sensor 45 and the torque TM ^* according to the vehicle speed V from the vehicle speed sensor 46, and determines this. Supply to the motor control device 43.

Further, the vehicle control device 41 supplies an engine ON / OFF signal to the engine control device 42. Specifically, for example, when the brake is depressed and the brake depression amount β is supplied from the brake sensor 47, the engine 11 is brought into a non-driving state and the engine is turned off.
A signal is supplied, and when the brake is released, an engine ON signal that drives the engine 11 is supplied. The engine ON / OFF signal may be switched according to ON / OFF of the accelerator.

The engine controller 42 is the vehicle controller 4
Based on the ON / OFF signal input from 1, the engine 11 is driven to output engine torque (O
N state) and a non-driving state (OFF state) in which engine torque is not generated, and controlling the throttle opening θ of the engine 11 according to the engine speed NE input from the engine speed sensor. Thus, the output of the engine 11 is controlled. Also,
The engine 11 is controlled by the engine control device 42 so that the engine 11 is always operated in the maximum efficiency region.

Further, the vehicle control device 41 turns on the solenoid to the electromagnetic valve 54 for operating the generator brake 28.
/ OFF signal is supplied. In the electromagnetic valve 54, a solenoid built in the electromagnetic valve 54 operates based on the supplied ON / OFF signal. For example, in the case of an ON signal, the solenoid operates to open the valve, and the When pressure oil is supplied to the generator brake 28 to bring the generator brake 28 into the engaged state and the OFF signal is given,
The valve is closed to disengage the generator brake 28.

The generator control device 44 controls the rotation speed NG of the generator 16 and controls the current (torque) IG so that the target rotation speed NG ^* supplied from the vehicle control device 41 is reached. The generator control device 44 can also drive the generator 16 as a motor by the current (torque) IG.

The motor control device 43 controls the electric current (torque) IM of the electric motor 25 so that the supplied torque TM ^* is output from the electric motor 25.

Next, the operation of the hybrid vehicle having the above structure will be described. FIG. 3A is a conceptual diagram of the planetary gear unit 13 (FIG. 1) according to the first embodiment of the present invention, and FIG. 3B is a speed of the planetary gear unit 13 according to the first embodiment of the present invention during normal traveling. It is a diagram.

In this embodiment, as shown in FIG. 3A, the number of teeth of the ring gear R of the planetary gear unit 13 is twice the number of teeth of the sun gear S.
Therefore, the unit output shaft 14 connected to the ring gear R
NR is the number of rotations of the
Let NE be the rotational speed of the engine output shaft 12 connected to the carrier CR (hereinafter referred to as "engine rotational speed"), and NE be the rotational speed of the transmission shaft 17 connected to the sun gear S (hereinafter referred to as "generator rotational speed"). .) Is NG, NR, N
The relationship between E and NG is as shown in FIG.

NG = 3.NE-2.NR.

During normal traveling of the hybrid vehicle, the ring gear R, the carrier CR and the sun gear S are all rotated in the positive direction, and as shown in FIG. The rotational speed NE and the generator rotational speed NG both take positive values.

Next, the control operation of the vehicle control device 41 will be described in detail based on the flowcharts of FIGS. 4, 9, 10 and 12 and the maps of FIGS. 5, 6, 7, 8 and 11. To do. The accelerator opening α is input to the vehicle control device 41 from the accelerator sensor 45 (step S10).
1), the brake pedal amount β is input from the brake sensor 47 (step S102), and the vehicle speed V is input from the vehicle speed sensor 46.
Is input (step S103), and the remaining battery level SOC is input from the battery sensor 48 (step S103).
104).

The input accelerator opening α, vehicle speed V,
From the battery remaining amount SOC, the engine speed-up rotation speed ΔNei is calculated based on the maps shown in FIGS. 5 to 7 (step S105). This map is stored in advance in the vehicle control device 41, and a map in a low speed range where the vehicle speed is 30 km / h or less (FIG. 5) and 30 to 60 km / h.
Map in the medium speed range, which is the range of h (Fig. 6), and 60 km
/ H or more in the high speed range map (Fig. 7).

In each map, the larger the accelerator opening α,
The engine acceleration speed ΔNei is set to increase as the engine acceleration speed ΔNei increases and the battery remaining amount SOC decreases. First, one of the three maps is selected according to the vehicle speed V, and thereafter, the engine speed increasing speed ΔNei on the vertical axis is determined from the accelerator opening α and the battery remaining amount SOC. In each map, acceleration / deceleration is 500r to save power.
The engine speed-up rotation speed ΔNei is obtained in the range of pm or more and 1500 rpm or less.

Next, based on the map shown in FIG. 8, the engine deceleration speed ΔNed is calculated from the brake depression amount β.
Is calculated (step S106). As shown in the flow chart of FIG. 9, the engine speed increasing speed ΔNei
Then, an engine speed increment ΔNe is obtained from the engine deceleration speed ΔNed (ΔNe = ΔNei−ΔNed) (step S107).

It is judged whether or not the obtained value of the engine speed increment ΔNe is in the range of -500 to 500 rpm (step S108). If it is within this range, the value of the engine speed increment ΔNe is set to 0 (step S109). If it is out of this range, the next step is executed.

The value of the engine speed increment ΔNe is 150
It is determined whether or not it is greater than 0 rpm (step S11).
0). If it is larger, the value of the engine speed increment ΔNe is set to 1500 (step S111). If so, perform the next step.

As shown in the flow chart of FIG. 10, the value of the engine speed increment ΔNe is -1500r.
It is determined whether it is smaller than pm (step S11).
2). If it is smaller, the value of the engine speed increment ΔNe is set to -1500 (step S113). If so, perform the next step. As described above, the value of the engine speed increment ΔNe is set to −1500 to 1500 rpm.
The reason why the range is limited to is because the maximum output of the generator 16 is taken into consideration.

Based on the map shown in FIG. 11, the engine speed (brake-on engine speed) Ne when the generator brake 28 is engaged and the generator 16 is fixed is Ne.
b is calculated (step S114). The brake-on engine rotation speed Neb is obtained by obtaining the engine rotation speed on the vertical axis from the vehicle speed on the horizontal axis by the straight line c in the map of FIG. The minimum required engine speed is 1000 to ensure engine idling.
It is set to rpm.

Next, the brake-on engine speed Neb
Then, the engine speed command value Nec is obtained from the engine speed increment ΔNe (Nec = Neb + ΔNe) (step S115). The rotation speed command value Nec is supplied from the vehicle control device 41 to the engine control device 42. As shown in FIG. 12, the engine speed command value Nec is 1
It is determined whether or not it is greater than 000 rpm (step S
116). If it is smaller, the generator 16 is run idle (step S117) to ensure idling of the engine 11.

When it is large, the engine speed increment ΔN
It is determined whether or not e is 0 (step S118), and 0
If so, an ON signal for engaging the generator brake 28 is output to the electromagnetic valve 54 (step S11).
9). By engaging the brake 28, it is possible to save electric power energy for keeping the generator stopped.

When the engine speed increment ΔNe is not 0, a value three times the engine speed increment ΔNe is set as the generator speed command value (step S120), and the command value is output to the generator 16. Here, the engine speed increment ΔNe
Is positive, the generator 16 generates electricity. Further, when the engine speed increment ΔNe has a negative value, the generator 16 is driven as a motor and discharged.

In the control operation described above, in the maps (FIGS. 5 to 7) for determining the engine speed increasing speed ΔNei, the engine speed increasing speed ΔNe increases as the battery remaining amount SOC increases.
Since the value of i is set small, the engine speed increment Δ
The value of Ne also decreases as the remaining battery charge SOC increases,
As a result, if the engine speed increment ΔNe becomes a negative value, the generator 16 is controlled to drive as a motor and consume the charge amount. Therefore, regenerative braking can be efficiently performed when the brake pedal is depressed.

The same applies to the case of a high vehicle speed, and as shown in FIG. 7, the larger the battery level is, the more negative the engine speed-up speed ΔNei becomes, and as a result, the engine speed is increased. The number increment ΔNe becomes a negative value, and the generator 16 is driven as a motor. Explaining with the engine best fuel consumption curve diagram of FIG. 13, the line a in the figure is the best fuel consumption curve, and the line b is the equal fuel consumption rate curve. Engine 1
1 is controlled by the engine control device 42 so as to drive along the best fuel consumption curve, and particularly during normal traveling,
It is controlled so as to drive within the region (a) where the fuel consumption is the highest in the constant fuel consumption rate curve.

When the vehicle speed becomes high, it is necessary to increase the engine speed. However, in the present invention, by driving the generator as a motor as described above, the generator can bear the increased speed. Therefore, the engine 11 can be driven in the best fuel economy region (a).

[0048]

As described above, according to the first aspect of the present invention, the engine speed is driven in the optimum efficiency region, and the insufficient output that occurs at that time is controlled by the generator speed. Therefore, it is possible to maintain high fuel consumption efficiency, and when the generator is driven as a motor, the amount of electricity stored in the electricity storage means can be arbitrarily reduced. It becomes possible to control the amount of.

According to a second aspect of the present invention, the battery remaining amount,
By controlling the engine speed based on the accelerator opening degree and the vehicle speed, the engine speed control and the generator control can be performed according to the running state, and a more efficient hybrid vehicle can be obtained.

According to the third aspect of the present invention, the rotation of the generator is reduced to 0 by providing the brake for stopping the rotation of the generator.
It is not necessary to consume the power for performing the control so that the power efficiency can be further improved.

According to a fourth aspect of the present invention, control of the generator rotational speed is performed according to the rotational speed controlled by the engine rotational speed control means by calculating the engine rotational speed when the brake is engaged. Will be easier.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a drive device for a hybrid vehicle according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control system according to the embodiment of the present invention.

FIG. 3 is a conceptual diagram and a velocity diagram of the planetary gear unit according to the embodiment.

FIG. 4 is a flow chart showing a control operation of the vehicle control device.

FIG. 5 is a map for determining one engine speed-up speed.

FIG. 6 is a map for determining an engine speed increasing speed.

FIG. 7 is a map for determining an engine speed increasing speed.

FIG. 8 is a map for determining an engine deceleration rotation speed.

FIG. 9 is a flow chart showing a control operation of the vehicle control device.

FIG. 10 is a flow chart showing the control operation of the vehicle control device.
It is.

FIG. 11 is a map for determining a brake-on engine speed.

FIG. 12 is a flow chart showing the control operation of the vehicle control device.
It is.

FIG. 13 is a best fuel consumption curve diagram of the engine.

[Explanation of symbols]

 11 engine 13 planetary gear unit 15 first counter drive gear 16 generator 18 rotor shaft 19 battery 25 electric motor 28 generator brake 41 vehicle control device 42 engine control device 43 motor control device 44 generator control device 45 accelerator sensor 46 vehicle speed sensor 47 Brake sensor 54 Electromagnetic valve

Claims (4)

[Claims] 1. An internal combustion engine, a generator whose rotation speed is controllable, a first gear element connected to the generator, a second gear element connected to an output shaft, and the internal combustion engine. Differential gear device having the above described third gear element, an electric motor rotating integrally with the output shaft, and an engine speed control for controlling the speed of the internal combustion engine within a predetermined range. A hybrid vehicle comprising: means and a generator control means for controlling the rotation speed of the generator according to the rotation speed controlled by the engine rotation speed control means. 2. The hybrid vehicle according to claim 1, wherein the engine speed control means controls the engine speed based on at least one of a battery remaining amount, an accelerator opening, and a vehicle speed. 3. The hybrid vehicle according to claim 1, wherein the generator control means includes a brake that stops rotation of the generator. 4. The hybrid vehicle according to claim 3, wherein the engine rotation speed control means includes an engagement-time rotation speed calculation means for calculating an engine rotation speed when the brake is engaged from a vehicle speed.