JP3373778B2 - Hybrid drive system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a hybrid drive system for vehicles.

[0002]

2. Description of the Related Art In order to improve exhaust emission of a vehicle, a hybrid drive system combining an engine and an electric motor, in which only the generator is driven by the engine,
It is known that the generated electric power is used to charge a battery and drive an electric motor, and the driving force of a vehicle depends only on the output of the electric motor.

[0003]

In such a hybrid drive system, since the range of rotational speed at which the electric motor can be operated at a constant output is limited, the maximum driving force and the maximum speed required for the vehicle can be obtained without using the transmission. There was a problem that it was difficult to make them compatible. JP-A-9-154204 discloses that a generator is driven when the output of the electric motor is insufficient with respect to the required driving force of the vehicle even when the charging rate of the battery is sufficiently high. However, even if the electric power from the generator is added to the electric power from the battery to the electric motor, a driving force exceeding the output performance (maximum torque) of the electric motor cannot be obtained.

The present invention has been made in view of these problems, and it is possible to secure the maximum speed and maximum driving force required for a vehicle without changing the output characteristics of the electric motor and without using a transmission. The purpose is to provide a hybrid drive system.

[0005]

According to a first aspect of the invention, an engine for driving a generator, a battery charged by the generator through a converter, and a battery and a generator driven by an inverter via an inverter. The electric motor for the vehicle and the output of the electric motor are reduced by a reducer, a propeller shaft, a differential, and an
In a vehicle including a drive system device that transmits to a wheel via a axle, an input shaft on an engine side and an output shaft on a generator side
A gearbox with a gear that meshes with the gear at a specified ratio
Is installed as an auxiliary power transmission mechanism.
Connect one end of the gear to the input shaft on the engine side of the speed increaser to
Input the other end of the auxiliary propeller shaft to the drive system gear reducer.
Before sandwiching the bevel gear connected to the shaft and the gear of the input shaft of the gearbox
A clutch to be installed later, a means for detecting the vehicle speed, a means for detecting the required driving force of the vehicle, and a predetermined value at which the vehicle speed shifts to the constant output region of the electric motor based on these detection signals. an input shaft of the generator converter and the speed increaser to actuate the generator as a motor when the required driving force of the vehicle in the low speed range is greater than or equal to the maximum torque of the electric motor
And means for controlling the front and rear clutches that sandwich the gear .

According to the second aspect of the invention, an engine for driving the generator, a battery charged by the generator through the converter, and an electric motor for driving the vehicle driven by the battery and the generator via the inverter. A drive system device for transmitting the output of the electric motor to the wheels; and, in a vehicle, an auxiliary power transmission mechanism for selectively connecting the engine to the generator and the drive system device for the vehicle, and means for detecting the vehicle speed, A means for detecting the required driving force of the vehicle and an engine when the required driving force of the vehicle is equal to or higher than the maximum torque of the electric motor in a low speed region below a predetermined value at which the vehicle speed shifts to the constant output region of the electric motor based on these detection signals. Means for controlling the transmission mechanism of the auxiliary power so as to transmit the output of the above to the drive system device of the vehicle.

In the third invention, the auxiliary power transmission mechanism in the first invention or the second invention is provided with a reverse rotation mechanism.

In the fourth invention, the auxiliary power transmission mechanism in the first invention or the second invention comprises a continuously variable transmission.

[0009]

According to the first aspect of the invention, the output of the electric motor is transmitted to the wheels (driving wheels) via the drive system device (which constitutes the power transmission path). In the low speed region where the vehicle speed is equal to or lower than a predetermined value, when the required driving force of the vehicle exceeds the maximum torque of the electric motor, the converter and the auxiliary power transmission mechanism are controlled so that the generator operates as the electric motor. As a result, the output of the generator is transmitted to the drive system device and added to the output of the electric motor as the driving force of the vehicle, so that a driving force exceeding the maximum torque of the electric motor can be obtained. As a result, the total reduction ratio of the drive system device is set so that the maximum speed required for the vehicle can be obtained as before, while the output characteristic of the electric motor is changed by operating the generator as the electric motor as described above. In addition, the required maximum driving force can be secured without using a transmission.

In the second aspect of the invention, the output of the electric motor is transmitted to the wheels (driving wheels) via the drive system device (which constitutes the power transmission path). In the low speed region where the vehicle speed is equal to or lower than the predetermined value, when the required driving force of the vehicle exceeds the maximum torque of the electric motor, the auxiliary power transmission mechanism is controlled so as to transmit the output of the engine to the drive system device. As a result, the output of the engine is added to the output of the electric motor as the driving force of the vehicle, so that the driving force exceeding the maximum torque of the electric motor can be obtained.
As a result, the total reduction ratio of the drive system device is set so that the maximum speed required for the vehicle can be obtained as before, while the output characteristic of the electric motor is changed by operating the generator as the electric motor as described above. In addition, the required maximum driving force can be secured without using a transmission.

According to the third aspect of the invention, the driving force exceeding the maximum torque of the electric motor can be obtained not only when the vehicle is moving forward but also when the vehicle is moving backward.

In the fourth aspect of the invention, it becomes possible to operate the generator or the engine near the best point of energy efficiency via the continuously variable transmission during transmission of the auxiliary power.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 is an engine for power generation, the output shaft of which is connected to a drive shaft of a generator 3 via a speed increaser 2. The AC power generated by the generator 3 is converted into DC power via the converter 4, and the battery 2
It is supplied to charge 1 (battery) and drive the electric motors 5 and 6.

Reference numeral 7 denotes an axle of the drive wheel 8,
The differential 9 is interposed in the middle part. Propeller shaft 1 on the drive pinion of differential 9
The output shaft of the speed reducer 11 is connected via 0.

The speed reducer 11 is provided with two input shafts sandwiching one output shaft, and electric motors 5 and 6 are connected to each of them. Further, gears 11a and 11b that are engaged with each other at the same gear ratio are provided between each input shaft and the output shaft.

The electric motors 5 and 6 are driven when AC power is received from the inverter 12. The output is transmitted to the wheels 8 via the reduction gear 11, the propeller shaft 10, the differential 9, and the axle 7. That is, the drive system device 13 in which the speed reducer 11, the propeller shaft 10, the differential 9, and the axle 7 transmit the outputs of the electric motors 5 and 6 to the wheels 8.
(Power transmission mechanism).

The gearbox 2 is a gear 2 that meshes between an input shaft on the engine 1 side and an output shaft on the generator 3 side with a predetermined gear ratio.
a and 2b are interposed, and one end of the auxiliary propeller shaft 14 is connected to the input shaft thereof as a component of the auxiliary power transmission mechanism 23. Also, the input shaft gear 2a
Clutches 15 and 16 are provided in front of and behind the pinion, and the other end of the auxiliary propeller shaft 14 is connected to one input shaft of the speed reducer 11 via bevel gears 17a and 17b.

A controller 18 for controlling the clutches 15 and 16 and the converter 4 of the generator 3 together with the inverters 12 of the electric motors 5 and 6 is provided, a vehicle speed sensor 19 for detecting the traveling speed (vehicle speed) of the vehicle, and an accelerator pedal depression. Accelerator opening sensor 20 for detecting the amount, and battery 2
And a means (not shown) for detecting the state of charge of the battery 1.

The converter 4 receives the signal from the controller 18 and converts the AC power generated by the generator 3 into the battery 2
1 and the power generation mode for converting the DC power to the inverter 12 and the electric mode for converting the DC power of the battery 21 to the AC power for the generator 3.

In response to a signal from the controller 18, the clutches 15 and 16 do not transmit the output of the engine 1 to the auxiliary propeller shaft 14 in the power generation mode of the converter 4 and input it to the generator 3 via the speed increaser 2, while Converter 4
In the electric mode of, disconnect the generator 3 from the engine 1,
The output of the generator 3 that operates as an electric motor is controlled to be transmitted to the auxiliary propeller shaft 14.

In FIG. 2, A is the maximum output line that can be given by the battery 21, B is the maximum output line of the electric motors 5, 6, and the electric motors 5, 6 have a predetermined vehicle speed in relation to their capacity (maximum torque). In the low speed region below the value P, the constant torque operation is controlled. Further, in the constant output region of the electric motors 5 and 6 (medium / high speed region where the vehicle speed exceeds a predetermined value), when only the battery 21 is driven as a power source, a driving force along the maximum output line A of the battery 21 is generated, When the battery 21 and the generator 3 are driven by the power source, the driving force is set to be increased by the amount of increase in the electric power of the generator 3 (hatched region C rising to the right).

FIG. 3 is a flow chart for explaining the control contents of the controller 18, which is started by turning on the key switch. In step 1, the operating regions of the electric motors 5 and 6 are determined based on the detection signal of the vehicle speed sensor 19. In the constant output region, the process jumps to step 6 to turn on (connect) the clutch 15 and turn off (disengage) the clutch 16 while switching the converter 4 to the power generation mode.

The output of the engine 1 is input to the generator 3 via the clutch 15 and the gearbox 2 and is not transmitted to the auxiliary propeller shaft 14. The AC power generated by the generator 3 is converted into DC power via the converter 4.

In step 7, based on the detection signal of the vehicle speed sensor 19 and the detection signal of the accelerator opening sensor 20,
The required electric power of the electric motors 5 and 6 (obtained by the product of the vehicle speed and the accelerator opening) is calculated, and when the calculated value is less than the maximum output line A of the battery 21 (see FIG. 2), step 8
In step 9, the engine 1 drives the generator 3 in accordance with the state of charge of the battery 21, while in step 9, the inverter 12 is controlled so that the battery 21 alone drives the electric motors 5, 6. The battery 21 is charged with the generated electric energy.

When the required power of the electric motors 5 and 6 exceeds the maximum output line A of the battery 21, the process jumps from step 7 to step 10 to drive the generator 3 with the insufficient electric power by the engine 1 and the electric motor 5 in step 11. , 6 are operated so that the maximum output line B (see FIG. 2) is not exceeded.

When the electric motors 5 and 6 are in the constant torque region, the process proceeds from step 1 to step 2 and only the battery 21 is used as a power source. Then, in step 3, the required driving force (accelerator opening) is detected from the detection signal of the accelerator opening sensor 20.
Determine the size of.

When the required driving force is less than or equal to the maximum torque of the electric motors 5 and 6, the routine jumps from step 3 to step 8 and the generator 1 is driven by the engine 1 in accordance with the charging state of the battery 21, while the battery is step 9 21 only electric motor 5,
Inverter 12 is controlled to drive 6.

When the required driving force exceeds the maximum torque of the electric motors 5 and 6, the clutch 15 is turned off and the clutch 16 is turned on in step 4, while the converter 4 is operated so that the generator 3 is operated as an electric motor in step 5. Switch to electric mode. The generator 3 is driven by the battery 21 as a power source, and its output is the gears 2a, 2b, the clutch 16,
It is transmitted to the speed reducer 11 of the drive system device 13 via the auxiliary propeller shaft 14 and the bevel gears 17a and 17b.

With such a structure, in the low speed region where the vehicle speed is equal to or lower than the predetermined value, the required driving force of the vehicle is the electric motors 5, 5.
When the maximum torque of 6 is exceeded, the generator 3 operates as an electric motor and its output is added to the outputs of the electric motors 5 and 6, so that a driving force that exceeds the maximum torque of the electric motors 5 and 6 is obtained.

A hatched area D in the lower right of FIG. 2 represents an increase in the driving force by the auxiliary power of the generator 3. Since the generator 3 is driven by the electric power of the battery 21, the maximum driving force does not exceed the maximum output line A of the battery 21.

The total reduction ratio of the drive system device 13 is set so that the maximum speed required for the vehicle can be obtained as before.
If the auxiliary power from the generator 3 to the drive system device 13 is obtained as described above, the required maximum driving force can be easily achieved without changing the output characteristics of the electric motors 5 and 6 and without using the transmission. Can be secured.

In the embodiment of FIG. 4, the auxiliary power transmission mechanism 23 is provided so that the auxiliary power of the generator 3 can provide a driving force exceeding the maximum torque of the electric motors 5 and 6 not only when the vehicle is moving forward but also when the vehicle is moving backward. A reversing mechanism 25 is provided (in this case, between the auxiliary propeller shaft 14 and the speed increasing gear 11).

As the reversing mechanism 25, the same mechanism as a known mechanism for switching to reverse of a transmission is adopted. Although detailed description is omitted, by selectively displacing the sliding gear with the dog clutch by the actuator, not only the input rotation can be transmitted as it is but also the reverse rotation can be transmitted.

Although not shown, if a continuously variable transmission (for example, a CVT or a torque converter) is provided in series with the reverse rotation mechanism, the generator 3 can be operated as an electric motor near the best point of energy efficiency. The same parts as those in FIG. 1 are designated by the same reference numerals.

In FIG. 1, when operating the generator 3 as an electric motor, the engine 1 is operated to operate both clutches 1.
When the valves 5 and 16 are turned on, the output of the engine 1 can also be transmitted to the drive system device 13 as auxiliary power. Further, when a clutch for connecting and disconnecting the generator 3 and the speed increaser 2 is added, the case of transmitting only the output of the generator 3, the case of transmitting only the output of the engine 1, and the output of the generator 3 It is also possible to control the auxiliary power in three stages, that is, when both the output of the engine 1 is transmitted.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram similarly illustrating control contents.

FIG. 3 is a flow chart for explaining control contents in the same manner.

FIG. 4 is a main part configuration diagram showing another embodiment.

[Explanation of symbols]

1 engine 3 generator 4 converter 5,6 electric motor 12 inverter 13 Drive system device (power transmission mechanism) 14 Auxiliary propeller shaft 15,16 clutch 17a, 17b Bevel gear 18 Controller 19 vehicle speed sensor 20 Accelerator position sensor 21 battery 23 Auxiliary power transmission mechanism 25 Reverse mechanism

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI B60K 6/04 551 B60K 6/04 551 B60L 11/12 B60L 11/12 F02D 29/02 F02D 29/02 D F16H 9/00 F16H 9/00 A 61/02 61/02 // F16H 59:18 59:18 59:44 59:44 (58) Fields investigated (Int.Cl. ⁷ , DB name) B60L 11/14 B60K 6/04 F02D 29/02 F16H 9/00 F16H 61/02 B60L 11/12

Claims (4)

(57) [Claims] 1. An engine for driving a generator, a battery charged by the generator through a converter, an electric motor for a vehicle driven by an inverter using the battery and the generator as power sources, and an output of the electric motor. Reducer, propeller shaft, de
In a vehicle including a drive system device that transmits to a wheel via a differential and an axle, an input shaft on an engine side
Teeth that mesh with the output shaft on the generator side at a specified tooth ratio.
A speed increaser for the vehicle is installed to provide an auxiliary power transmission mechanism.
The end of the auxiliary propeller shaft to the engine side of the gearbox.
Drive the other end of the auxiliary propeller shaft by connecting to the input shaft of
Of the bevel gear connected to the input shaft of the speed reducer
It is equipped with a clutch that is inserted between the front and rear of the input shaft gear.
On the other hand , the means for detecting the vehicle speed, the means for detecting the required driving force of the vehicle, and the required driving force for the vehicle in a low speed region below a predetermined value at which the vehicle speed shifts to the constant output region of the electric motor based on these detection signals. Is a maximum torque of the electric motor or more, the converter of the generator and a means for controlling the clutch before and after sandwiching the gear of the input shaft of the speed increaser so as to operate the generator as the electric motor, are provided. Hybrid drive system. 2. An engine for driving a generator, a battery charged by the generator via a converter, an electric motor for vehicle running driven by an inverter using the battery and the generator as power sources, and an output of the electric motor. In a vehicle including a drive system device that transmits power to a wheel, an auxiliary power transmission mechanism that selectively connects an engine to a generator and a drive system device of the vehicle, a means for detecting a vehicle speed, and a required drive device for the vehicle. A means for detecting the force, and based on these detection signals, when the vehicle drive speed is in a low speed region below a predetermined value at which the vehicle speed shifts to the constant output region of the electric motor, when the required driving force of the vehicle is equal to or higher than the maximum torque of the electric motor, the output of the engine And a means for controlling the transmission mechanism of the auxiliary power so as to transmit it to the drive system device. 3. The hybrid drive system according to claim 1, wherein the auxiliary power transmission mechanism includes a reverse rotation mechanism. 4. The hybrid drive system according to claim 1, wherein the auxiliary power transmission mechanism includes a continuously variable transmission.