JPH04297330A - Series-parallel complex hybrid car system - Google Patents

Abstract

PURPOSE:To provide such a series-parallel complex hybrid car system that is solving any regenerative braking torque shortage at the high speed side of a motor at time of regenerative braking, and capable of securing an almost constant regenerative braking torque ranging from low to high speed rotation. CONSTITUTION:The system is provided with an engine 1, a generator 3, a traveling motor 9 and a battery 17, while it installs a continuously variable transmission 5 in space between the engine 1 and the motor 9, and simultaneously there is provided a control means 18 which controls the continuously variable transmission 5 so as to make up for a regenerative braking torque insufficient portion at the high speed side of the motor 9 with the resultant torque of friction torque of the engine 1 and regenerative braking torque of the generator 3.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is applicable to series and parallel hybrid car systems driven by an engine and motor, and especially to series and parallel hybrid car systems that can compensate for the lack of torque on the high rotation side of the motor with the torque of the engine. It's about systems.

0002

BACKGROUND OF THE INVENTION In recent years, social demands for saving resources and preventing air pollution and noise have been increasing. In response to these demands, hybrid car systems, or hybrid electric vehicles, are attracting attention, which include an engine, a generator driven by the engine, a motor for driving, and a battery that supplies power to the motor. ing. Conventionally, as such a hybrid car system, there are
02, and Utility Model Application Publication No. 53-55105, etc., devices have been developed. In each of the above publications,
All of these documents describe the configuration of an electric vehicle in which a driving motor and an engine are connected via a clutch to a rotating shaft.

That is, FIG. 1 of Japanese Utility Model Application Publication No. 51-103220 shows a generator in which a motor and an engine are connected via a rotating shaft and a clutch, and which is driven by the engine via a speed increasing mechanism. A composite electric vehicle is described which is equipped with a storage battery which is charged by the generator and which supplies electric power to the motor to drive it. This device is equipped with a clutch, so when the clutch is disengaged, it is in series driving mode. In other words, the electric power generated by the generator driven by the engine is temporarily stored in the storage battery, and the electric power supplied from the storage battery is used to power the driving motor. It will take a driving mode that rotates. Furthermore, when the clutch is engaged, a parallel running mode, that is, a running mode in which the vehicle is driven by both the engine and the motor and the generator also generates electricity, can be adopted.

0004

[Problems to be Solved by the Invention] Conventional Problems The conventional device described above has a configuration that allows switching between parallel running and series running at any time by switching the clutch. No device was installed to change the coupling state according to the load and control the engine torque according to the motor torque to keep the engine load range constant.

It is true that in the parallel running mode, the engine output and the motor output can be used at the same time, which is advantageous when a large torque is required such as when accelerating or climbing a hill, but in general, the The maximum efficiency points of engines and motors with respect to number (rotational speed) are not equal; motors exhibit high efficiency at relatively high rotational speeds, whereas engines have high efficiency at relatively low rotational speeds. Therefore, when the motor and engine are connected at a fixed gear ratio, the load range of the engine is not always in the best condition, which is not preferable in terms of improving fuel efficiency.

Furthermore, in the series driving mode, since the engine is used only for power generation, the engine load range can be set to a fuel-efficient range, but on the other hand, only the output of the driving motor can be used to drive the vehicle. , there was a problem that acceleration performance deteriorated.

Furthermore, when braking is applied while the motor is rotating at a relatively high speed, as shown in FIG. 3(a),
The problem is that the regenerative braking torque a from the driving motor decreases significantly at high rotation speeds, resulting in a torque shortage by the shaded torque c in the figure with respect to the ideal torque line b, resulting in poor brake effectiveness. There was a point. Therefore, there is a problem that the above problems must be solved.

Purpose of the Invention The present invention has been made to solve the above-mentioned problems, and eliminates the lack of regenerative braking torque on the high rotation side of the motor during regenerative braking, and achieves almost constant regeneration from low speed rotation to high speed rotation. The purpose is to provide a series and parallel composite hybrid car system that can obtain braking torque.

[0009]

[Means for solving the problem] A series according to the present invention,
A parallel composite hybrid car system includes an engine, a generator driven by the engine, a motor for driving, a battery that transfers power between the generator and the motor, and a link between the engine and the motor. Torque transmission means for mutually transmitting torque between a clutch provided in the engine, the generator, the clutch, and the motor;
and torque transmission means for transmitting the rotational torque of the motor to the wheels. Further, a continuously variable transmission is provided between the engine and the motor, and the lack of regenerative braking torque on the high rotation side of the motor is compensated for by a composite torque of the engine's friction torque and the generator's regenerative braking torque. The invention further includes a control means for controlling the continuously variable transmission.

0010

[Operation] Next, the operation of the present invention will be explained. A series of parallel composite hybrid car systems according to the present invention include:
First, electricity is generated by a generator driven by the engine,
The obtained electric power is temporarily stored in a battery, and then the electric power stored in the battery is supplied to a driving motor to drive the vehicle, thereby causing the vehicle to travel. The battery transfers power between the generator and the motor. When the clutch provided between the engine and the motor is connected, the engine,
Torque is transmitted between the generator, the clutch, and the motor, and the rotational torque of the motor is transmitted to the wheels, so that the vehicle is driven by the driving torque of both the engine and the motor. Further, a continuously variable transmission is provided between the engine and the motor, and the continuously variable transmission is used to convert the insufficient regenerative braking torque on the high rotation side of the motor into the friction torque of the engine and the generator. By controlling the control means to compensate for the regenerative braking torque with a composite torque of the regenerative braking torque and keeping the regenerative braking torque constant, it is possible to eliminate the shortage of regenerative braking torque on the high rotation side of the motor during regenerative braking.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the basic concept of an embodiment of a series/parallel composite hybrid car system according to the present invention.

In the figure, reference numeral 1 denotes an engine, which is connected to a generator 3 via an output shaft 2, and further has output shafts 4 and 6.
, 8, etc. via a torque transmission means such as a continuously variable transmission (
A CVT (CVT) 5, a clutch 7, and a driving motor 9 are connected in sequence and configured to transmit torque to each other. Furthermore, the rotational torque of the motor 9 is determined by the transmission 10 and the output shaft 1.
1, the torque is transmitted to the wheels 14 via a torque transmission means consisting of a differential gear device 12 and an accelerator shaft 13.

The continuously variable transmission 5 is a CVT (Continuous Variable Transmission) that allows the ratio of the rotational speeds of the output shafts 4 and 6 to be appropriately and continuously changed by a control means to be described later.
transmission). Further, a clutch 7 provided between the output shafts 6 and 8 serves to connect and disconnect the output shafts 6 and 8. Furthermore, the motor 9 is installed together with a transmission 10 between the output shafts 8 and 11, and drives the wheels 14 as an electric device for traveling.

The generator 3 is connected to the battery 17 via the power converter 15, converts the rotational energy of the engine 1 and the braking energy transmitted from the wheels 14 via the torque transmission means into electrical energy, Store at 17. The motor 9 receives power from the battery 17 via the power converter 16 during running, and regenerates braking energy to the battery 17 via the power converter 16 during regenerative braking. 18 is an electronic control unit (ECU) that controls the continuously variable transmission 5 and the power converters 15 and 16.

As shown in FIG. 2, an engine 1 and a motor 9
The best efficiency range is different from that for parallel running, and if engine 1 and motor 9 are connected directly or with a fixed gear ratio, it is not necessarily possible to operate engine 1 in the best fuel efficiency range. Can not. Therefore, in this invention, the gear ratio of the continuously variable transmission 5 is optimally controlled by the electronic control unit 18 so that the load range of the engine 1 is in the best fuel efficiency range, and even when driving with the engine 1 as a power source, It has a configuration that allows it to run with the best fuel efficiency.

That is, at the operating point A in FIG. 2(b), the motor 9
When the engine 1 is being driven and power is required for climbing a hill or sudden acceleration, the conventional technology would simply drive the engine 1 at the operating point A in Figure 2(a), resulting in lower fuel efficiency. It had to get worse. However, according to the above embodiment of the present invention, the operating point of the engine 1 can be shifted to point B in FIG. 2(a) by appropriately controlling the gear ratio of the continuously variable transmission 5 by the electronic control device 18. This makes it possible to achieve the best fuel efficiency.

Therefore, when using the above-mentioned device, a series running mode is normally used in which running is performed using only the motor 9, and also during steady running when the engine 1 is relatively efficient, or during acceleration when the motor 9 alone does not have enough power. By engaging the clutch 7 to set the parallel running mode when driving and climbing hills, and by appropriately controlling the gear ratio of the continuously variable transmission 5, driving force can be efficiently supplied from the engine 1.

On the other hand, the torque characteristic of the motor 9 during regenerative braking is as shown in the solid line section a in FIG. As shown in b, the braking force is ultimately insufficient on the high-speed rotation side of the motor 9 by the torque shortage c shown by diagonal lines in the figure. Therefore, in the above embodiment, the friction torque d of the engine 1 and the regeneration torque e of the generator 3 shown in FIG.
The gear ratio of the continuously variable transmission 5 is optimally controlled by the electronic control device 18 so that a large torque is obtained on the high rotation side from the resultant torque f of the motor 9, thereby compensating for the lack of braking force on the high rotation side of the motor 9. be able to.

Next, the control operation of the continuously variable transmission 5 by the electronic control unit 18 will be explained with reference to FIGS. 4 and 5.

First, in step 101, the accelerator signal is set to O.
When it becomes FF, it is determined in step 102 whether the rotational speed of the motor 9 corresponding to the current vehicle speed is greater than the rated rotational speed Vn, and if YES, the process immediately proceeds to step 10.
Proceed to step 3 and turn on clutch 7. In the subsequent step 104, the gear ratio of the continuously variable transmission 5 is set with a slight delay from the clutch ON operation in step 103, and then the brake signal is turned ON in step 105 to generate braking torque (step 106). On the other hand, if the rotational speed of the motor 9 is smaller than the rated rotational speed Vn in step 102, the process immediately jumps to step 105 and turns on the brake signal to generate braking torque.

On the other hand, when the accelerator signal is turned ON, the clutch 7 and brake signal are turned OFF, and the motor 9 is turned OFF.
The generation of braking torque is also stopped.

As explained above, the above embodiment eliminates the shortage of regenerative braking torque on the high rotation side of the motor during regenerative braking, and can obtain substantially constant regenerative braking torque from low speed rotation to high speed rotation.

In addition, in the case of parallel running, both the engine 1 and the motor 9 can be operated in the best efficiency range, and by disengaging the clutch 7 during low speed and steady running and running in series, regenerative braking can be applied. It is possible to increase the amount of energy recovered by the amount of engine friction.

Furthermore, since the battery can be kept charged at all times except during acceleration, deep discharges are reduced and the life of the battery can be improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, the generator 3 may not be installed on the same axis as the engine 1 and the motor 9, but may be installed as appropriate. It goes without saying that the invention can be implemented in various ways without departing from the spirit of the invention, such as arranging it in parallel to the output shaft 2 via a speed-increasing gear device.

[0026]

[Effects of the Invention] As explained above, the series/parallel composite hybrid car system according to the present invention is provided with a continuously variable transmission between the engine and the motor, and the regenerative braking torque deficiency on the high rotation side of the motor is eliminated. The configuration includes a control means for controlling the continuously variable transmission so as to compensate for the engine's friction torque with a composite torque of the engine's friction torque and the generator's regenerative braking torque. This has the effect of eliminating regenerative braking torque that is almost constant from low speed rotation to high speed rotation.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing the basic concept of an embodiment of a series parallel composite hybrid car system of the present invention.

FIG. 2(a) is a characteristic diagram showing the relationship between engine rotation speed, torque, and constant fuel consumption rate, and FIG. 2(b) is a characteristic diagram showing the relationship between motor rotation speed, torque, and efficiency.

[Figure 3] (a) is a diagram showing the relationship between motor rotation speed and regenerative braking torque, (b) is a diagram showing the relationship between engine rotation speed, friction torque, generator regeneration torque, and their combined torque FIG.

FIG. 4 is a flowchart showing the operation of the system according to the invention.

FIG. 5 is a time chart showing the operation timing of the system according to the present invention.

[Explanation of symbols]

1 Engine 2, 4, 6, 8, 11 Output shaft 3 Generator 5 Continuously variable transmission (CVT) 7 Clutch 9 Motor 10 Transmission 14 Wheels 15, 16 Power converter 17 Battery 18 Electronic control unit (ECU)

Claims (1)

[Claims] Claim 1: An engine, a generator driven by the engine, a motor for driving, a battery for transmitting and receiving electric power between the generator and the motor, and a battery provided between the engine and the motor. A series, parallel composite hybrid comprising: a clutch that is connected to the engine, a torque transmission means that transmits torque to each other between the engine, the generator, the clutch, and the motor; and a torque transmission means that transmits the rotational torque of the motor to the wheels. In the car system, a continuously variable transmission is provided between the engine and the motor, and the lack of regenerative braking torque on the high rotation side of the motor is replaced by a composite torque of the friction torque of the engine and the regenerative braking torque of the generator. A series of parallel composite hybrid car systems characterized by comprising a control means for controlling the continuously variable transmission in a supplementary manner.