CN201002506Y - Power couplings for hybrid vehicles - Google Patents

Abstract

The utility model discloses a power coupling device for a hybrid electric vehicle. The device adopts a traditional differential gear, and its left half-shaft gear (1) and right half-shaft gear (2) are respectively connected to a generator (7) and a motor ( 8), the driving gear (6) of the final drive is fixed on the output shaft of the engine (9), the driven gear (3) of the final drive is meshed with the driving gear (6) of the final drive, and the cross shaft (5) Drive the planetary gear (4), and the motor (8) is connected to the drive axle (11) to drive the wheels (12) to travel. Engine controller (17) and generator controller (14), motor controller (13) of the switch of control power source, rotating speed and torque are respectively installed on engine (9) and automobile chassis, and these controllers are all controlled by The vehicle controller (16) coordinates and controls in a unified manner. The utility model simplifies trial production, eliminates mechanisms such as transmissions and clutches, and can realize stepless automatic transmission.

Description

Power couplings for hybrid vehicles

technical field

The utility model relates to a device for realizing power distribution and control between power sources in a drive system of a hybrid electric vehicle, in particular to a power coupling device for a hybrid electric vehicle.

Background technique

Energy saving and environmental protection are the two major themes of automobile development in the 21st century. Electric vehicles are ideal substitutes for traditional fuel internal combustion engine vehicles. However, due to the limitation of battery energy and the high cost of fuel cells, hybrid vehicles can be regarded as a comprehensive solution to the above feasible solution to the problem. A hybrid vehicle is powered by two or more power sources. The current common solution is to combine an engine with an electric motor and a generator. How to realize the power distribution between the engine, motor and generator of hybrid electric vehicles is one of the key problems that must be solved in the development of hybrid electric vehicles.

Hybrid electric vehicles have a variety of power sources, such as energy storage components and engines, so their driving methods are also relatively diverse. According to the combination of power sources, it can be divided into series hybrid vehicle (SHV), parallel hybrid vehicle (PHV) and series parallel hybrid vehicle (SPHV).

In a parallel hybrid vehicle (PHV), the engine and the drive wheels are mechanically connected, but a generator and an electric motor are added between the engine and the drive wheels. Generators and motors can both generate electricity and drive electricity. In a PHV, the engine outputs most of the power to drive the car, and the generator and electric motor act as auxiliary power sources for the engine when the required torque changes rapidly, such as acceleration and deceleration. Since the mechanical energy of the engine can be directly output to the drive axle of the car, there is no energy conversion in the middle, the system efficiency is high, and the fuel consumption is also low. A series hybrid vehicle (SHV) has a secondary power source (which can be an engine-driven generator, a solar cell that converts solar energy into electricity, or a fuel cell that converts the chemical energy of the oxide system directly into electricity). Its drive motor is the same as that of a pure electric vehicle (PEV). Since there is no direct mechanical connection between the engine and the drive wheels of the SHV, it is relatively easy to optimally control the power source. As a result, the engine can be stabilized in a high-efficiency zone or a low-emission zone work nearby. Therefore, the emission of SHV is better than that of conventional vehicles and PHV, and the frequency of external charging is further reduced compared with PEV.

Series-parallel hybrid electric vehicles (SPHV) can be further divided into: switch-type SPHV and continuous-type SPHV, which can be switched to parallel or series according to control requirements, both of which combine the advantages of series and parallel solutions. Therefore, Has the best overall performance.

At present, most of the power coupling devices for series and parallel use are complex planetary gear mechanisms, or some need to install transmissions, clutches and other devices, so that the structure of the entire transmission system is not compact. These mechanisms generally require a large modification or redesign, which requires high production technology and a long trial-manufacturing cycle; in addition, the control of the planetary gear mechanism is relatively complicated and difficult to realize in engineering.

Contents of the invention

The technical problem to be solved by the utility model is to overcome the existing problems in the prior art, and provide a power coupling device using a traditional differential for a vehicle as a hybrid vehicle.

In order to solve the above-mentioned technical problems, the utility model adopts the following technical solutions to realize. The power coupling device adopts a traditional differential, the left side gear and the right side gear of the differential are respectively connected to the generator and the motor through the left and right side shafts, and the driving gear of the final drive is fixedly connected to the On the output shaft of the engine, the driving gear of the main reducer and the driven gear of the main reducer are meshed in a state where the rotation axes of the two are coplanar and perpendicular to each other. The driven gear of the main reducer is the same as the left side shaft gear. The axis of rotation, the driven gear of the main reducer drives the planetary gear meshed with the left side gear and the right side gear through the cross shaft to rotate around the axis of the left side gear and the right side gear, and the output shaft of the motor passes through the drive shaft Connect the drive axle to drive the wheels. The engine, generator and electric motor are installed on the chassis of the car respectively.

On the input shaft on the left side of the electric motor described in the technical solution, an electronically controlled clutch and an electronically controlled brake are installed sequentially from right to left; The chassis of the car is equipped with a generator controller and a motor controller that control the switch of the generator and the motor, the speed and the load torque; the engine and the engine controller are connected by signal lines, and the generator and the generator controller are installed on the chassis of the car The storage battery, motor controller and motor on the vehicle are connected with cables in turn; a vehicle controller that coordinates and controls the engine controller, generator controller and motor controller is installed on the vehicle, and the vehicle controller is connected with the engine control system respectively. The generator, generator controller and motor controller are connected with signal lines. On the chassis of the car, a starter that controls the engine to start is installed. The vehicle controller is equipped with a self-compiled computer program device for unified coordination and control of the engine controller, generator controller and motor controller. The gearbox enables the engine, generator and electric motor to realize the following work flow:

1. The vehicle controller checks the cycle speed of the last time step;

2. The vehicle controller checks the cycle speed of the current time step;

3. The vehicle controller receives the status signals of each assembly of the current drive system;

4. The vehicle controller calculates the road load torque (or power) demand and rotational speed demand according to the current cycle speed and current acceleration;

5. Calculate the motor speed according to the road load speed demand;

6. According to the assembly state signals such as road load power demand and battery power state, calculate the engine optimal operating point speed and torque, and the vehicle controller outputs state instructions to the engine controller;

7. According to the relationship between differential speed and torque:

2ω _e =ω _g +ω _m

$T_g=\frac{T_e}{2}$ (Formula I)

${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="T\; e"\; filenames="Y20072009326000121.png"\; state="\{\{state\}\}">T</figure-callout></span><figure-callout\; id="2"\; label="T\; e"\; filenames="Y20072009326000121.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}$

In the formula: ω _e , ω _g , ω _m --- respectively engine speed, generator speed and motor speed;

T _e , T _g , T _m , T _L -- respectively, the output torque of the engine, the generating torque of the generator, the electric torque of the motor and the load torque;

Since the engine (9) optimal operating point speed and torque are calculated and determined in step 6, the speed and torque of the generator can be calculated, and the vehicle controller outputs a state command to the generator controller;

8. Calculate the motor torque according to the road load torque requirement and the above formula I, and connect the motor speed determined in step 5, and the vehicle controller outputs a state command to the motor controller;

9. Determine whether the cycle is over, if not, repeat the above steps.

The beneficial effects of the utility model are:

1. Use the traditional differential as the power coupling device for hybrid electric vehicles to realize the continuous series-parallel drive form of hybrid electric vehicles. The utility model is based on the principle of rotational speed difference and torque average distribution of the traditional symmetrical differential used in automobiles, so that the input shaft is connected to the engine, and the two output shafts are respectively connected to the motor and the generator, so that half of the torque output by the engine power can be achieved. The output is sent to the generator to generate electricity, and the other half of the torque drives the wheels to realize the continuous series-parallel drive form of the hybrid electric vehicle. Therefore, the differential can be used as a power coupling device of a hybrid electric vehicle, thereby greatly simplifying the new design and trial production of the power coupling device of a hybrid electric vehicle, saving time and cost.

2. The electric continuously variable transmission (ECVT) function can be realized by using the power coupling device for hybrid electric vehicles, and the transmission can be eliminated to simplify the whole system. The device makes use of the relationship between differential speed, torque transmission and distribution, and adjusts the speed and torque of the generator to make the engine work at the best efficiency point, which completely solves the working point efficiency of the traditional engine due to the mechanical connection with the wheels. Low problem, so as to realize the ECVT function. And the motor with high torque characteristics can be used to realize the torque increasing function of the traditional transmission, so that the transmission and other mechanisms can be eliminated.

3. By using the power coupling device for the hybrid electric vehicle and reasonably controlling the output power of the generator, the function of adjusting the battery SOC (state of charge) in real time during driving can be realized.

4. Referring to Fig. 6, what Fig. 6 shows is the derivation device of another kind of technical scheme of the power coupling device that the hybrid electric vehicle is used, promptly in the power coupling device that the hybrid electric vehicle is used as shown in Fig. 1, the input on the left side of the electric motor An electronically controlled clutch and an electronically controlled brake are sequentially installed on the shaft from right to left. When the engine stops working, the clutch is disengaged, and the whole vehicle can be driven by the electric motor, which can realize the function of pure electric driving. Pure electric driving can save fuel consumption to a greater extent and further improve the efficiency of the whole vehicle. This kind of power coupling device for hybrid electric vehicles can also realize series drive, that is, when the battery SOC is low, the electronically controlled clutch is disengaged, the electronically controlled brake is engaged, and the engine only charges the generator, so that the battery SOC can be quickly maintained to a reasonable level. range, which can reduce the deep discharge of the battery and improve the service life of the battery.

Description of drawings

Fig. 1 is a structural schematic diagram of a power coupling device using a conventional differential as a hybrid vehicle;

Fig. 2 is the working flow chart that adopts traditional differential gear as the power coupling device that hybrid electric vehicle is used;

Fig. 3 is a curve showing the periodical change law of each shaft speed in a typical driving mode of a power coupling device using a traditional differential as a hybrid vehicle;

Fig. 4 has provided the torque variation law curve of the power source (generator, electric motor, engine) output that adopts traditional differential as the power coupling device that each axle of hybrid electric vehicle is connected;

Figure 5 is a comparison curve of the relationship between the rotational speeds of each shaft in a typical driving mode of a power coupling device using a traditional differential as a hybrid vehicle;

Fig. 6 is a schematic structural diagram of a derivative device that uses a traditional differential as a power coupling device for a hybrid electric vehicle that can realize another technical solution for pure electric driving;

Fig. 7 is a work flow chart showing the derivative device of the conventional differential shown in Fig. 6 as the power coupling device for hybrid electric vehicles for hybrid drive

Fig. 8 is a curve showing the periodical change law of each shaft speed in another typical driving mode of the derivative device adopting the traditional differential as the power coupling device for the hybrid vehicle;

Fig. 9 is to have provided the torque change rule curve that the power source (generator, electric motor, engine) output that adopts traditional differential as the derivative device of the power coupling device that hybrid electric vehicle is connected to each shaft;

In the figure: 1. Left half shaft gear, 2. Right half shaft gear, 3. Driven gear of final reducer, 4. Planetary gear, 5. Cross shaft, 6. Driving gear of final reducer, 7. Generator , 8. Electric motor, 9. Engine, 10. Battery, 11. Drive axle, 12. Wheel, 13. Motor controller, 14. Generator controller, 15. Starter, 16. Vehicle controller (ECU), 17. Engine controller, 18. Motor speed (curve), 19. Engine speed (curve), 20. Generator speed (curve), 21. Motor operating torque (curve), 22. Engine operating torque (curve) , 23. Generator operating torque (curve), 24. The sum of generator speed and motor speed (curve), 25. Twice the engine speed (curve), 26. Electronically controlled brake, 27. Electronically controlled clutch.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail:

Referring to Fig. 1, the described power coupling device of hybrid electric vehicle is to adopt traditional differential gear, realizes the power distribution between power sources (generator 7, electric motor 8, engine 9) in hybrid electric vehicle driving system with work. The left side gear 1 and the right side gear 2 of the differential are respectively connected to the generator 7 and the motor 8 through the left and right side shafts, the driving gear 6 of the final drive is fixedly connected to the output shaft of the engine 9, and the final drive The driving gear 6 of the main reducer and the driven gear 3 of the main reducer are meshed in the state that the two rotation axes are coplanar and perpendicular to each other. The driven gear 3 of the final reducer and the left side shaft gear 1 are on the same rotation axis, The rotation axis of the side gear 1 is in line with the rotation axis of the right side gear 2, and the driven gear 3 of the final reducer drives the planetary gear 4 meshing with the left side gear 1 and the right side gear 2 through the cross shaft 5 Rotating around the axis of rotation of the left side gear 1 and the right side gear 2, the output shaft of the motor 8 is connected to the drive axle 11 through the transmission shaft, thereby driving the wheels 12 to travel. The engine 9, the generator 7 and the electric motor 8 are respectively installed on the chassis of the automobile.

The engine controller 17 that controls the switch of the engine 9, the load torque and the rotating speed is installed on the engine 9, and the generator controller 17 that controls the switch, the rotating speed and the load torque of the generator 7 and the motor 8 is installed on the chassis of the automobile. 14 and the motor controller 13; the engine 9 is connected with the engine controller 17 with a signal line, and the generator 7, the generator controller 14, the storage battery 10 installed on the chassis of the automobile, the motor controller 13 and the motor 8 are connected with the cable successively In addition, the whole vehicle controller (ECU) 16 of unified coordination and control engine controller 17, generator controller 14 and motor controller 13 is also installed on the car, and the whole vehicle controller 16 accepts the key switch signal, and the accelerator pedal, Brake pedal, gear position, vehicle speed, SOC and other vehicle signals comprehensively control the engine controller 17, generator controller 14 and motor controller 13, and then determine the working status of the three major power sources so as to meet the road load requirements of the vehicle. While meeting the power requirements, keep the battery SOC balanced and keep the system working in the high-efficiency zone. The vehicle controller 16 is respectively connected with the engine controller 17, the generator controller 14 and the motor controller 13 with signal lines. The starter 15 that controls engine to open is installed on the chassis of automobile. Referring to Fig. 2, the computer program device of the unified coordination and control engine controller 17, generator controller 14 and motor controller 13 of self-editing is housed on the vehicle controller 16, under the control of the vehicle controller 16, as The traditional differential of the power coupling device of hybrid electric vehicles enables the engine, generator and electric motor to realize the following workflow:

1. The vehicle controller 16 checks the cycle speed of the last time step;

2. The vehicle controller 16 checks the cycle speed of the current time step;

3. The vehicle controller 16 receives the status signals of each assembly of the current drive system;

4. The vehicle controller 16 calculates the road load torque (or power) demand and rotational speed demand according to the current cycle speed and the current acceleration;

5. Calculate the motor speed according to the road load speed demand;

6. According to the assembly state signals such as the road load power demand and the power state of the battery 10, calculate the optimal operating point speed and torque of the engine 9, and the vehicle controller 16 outputs a state command to the engine controller 17;

7. According to the relationship between differential speed and torque:

2ω _e =ω _g +ω _m

$T_g=\frac{T_e}{2}$ (Formula I)

${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="T\; e"\; filenames="Y20072009326000121.png"\; state="\{\{state\}\}">T</figure-callout></span><figure-callout\; id="2"\; label="T\; e"\; filenames="Y20072009326000121.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}$

In the formula: ω _e , ω _g , ω _m --- respectively engine speed, generator speed and motor speed;

T _e , T _g , T _m , T _L -- respectively, the output torque of the engine, the generating torque of the generator, the electric torque of the motor and the load torque;

Since the engine (9) optimal operating point speed and torque are calculated and determined by the 6th step, the speed and torque of the generator 7 can be calculated, and the vehicle controller 16 outputs a state command to the generator controller 14;

8. Calculate the motor torque according to the road load torque requirement and the above formula 1, and connect the motor speed determined in step 5, and the vehicle controller 16 outputs a state command to the motor controller 13;

9. Determine whether the cycle is over, if not, repeat the above steps.

Referring to Fig. 6, it is a derivative device of the power coupling device for hybrid electric vehicles shown in Fig. 1, that is, on the basis of the power coupling device for hybrid electric vehicles shown in Fig. On the input shaft, an electronically controlled clutch 27 and an electronically controlled brake 26 are installed sequentially from right to left. When the electrically controlled brake 26 was separated and the clutch 27 was engaged, the power coupling device for this hybrid vehicle was identical to the above-mentioned differential device. But by engaging the brake 26, when the clutch 27 is separated and controlled, and when the engine is turned off, the electric energy in the storage battery 10 is utilized to drive the whole vehicle with the electric motor 8 to realize pure electric running; The SOC drop is low. When the SOC of the battery 10 is low, the engine 9 can participate in the work to charge the generator 7, and the SOC of the battery 10 can be maintained within a reasonable range to maintain the balance of the SOC of the battery 10 and maintain the system at high efficiency. district work. Referring to Fig. 7, under the control of the vehicle controller 16, the power coupling device of the derivative device enables the engine 9, the generator 7 and the motor 8 to realize the following work flow:

1. The vehicle controller 16 checks the cycle speed of the last time step;

2. The vehicle controller 16 checks the cycle speed of the current time step;

3. The vehicle controller 16 receives the status signals of each assembly of the current drive system;

4. The vehicle controller 16 calculates the road load torque (or power) demand and rotational speed demand according to the current cycle speed and the current acceleration;

5. The vehicle controller 16 judges whether to run purely electric according to the vehicle speed, road load power demand and assembly status signal;

6. If it is purely electric, then disengage the clutch 27, and turn off the engine 9 and the generator 7, and output state instructions to the motor controller 13;

7. If it is not purely electric, calculate the optimal operating point speed and torque of the engine 9, and the vehicle controller 16 outputs a state command to the engine electronic controller 17;

8. Calculate the rotational speed of the electric motor 9 according to the rotational speed of the complete vehicle, and calculate the rotational speed and torque of the generator 7 by using the differential rotational speed and torque relational formula 1, and the complete vehicle controller 16 outputs a state command to the generator controller 14;

9. Calculate the speed and torque of the motor 8 according to the speed of the vehicle, and the vehicle controller 16 outputs a state command to the motor controller 13;

10. Determine whether the cycle is over, if not, repeat the above steps.

The working principle of the utility model is:

Referring to Fig. 1, the engine 9 is used as the main power source of the hybrid electric vehicle. When the car is running, the engine 9 drives the driving gear 6 of the final drive to rotate, and the driving gear 6 of the final drive drives the driven gear 3 of the final drive to rotate. The driven gear 3 of the main reducer drives the generator 7 and the motor 8 to rotate through the cross shaft 5, the planetary gear 4, the left side shaft gear 1, the right side shaft gear 2 and the left and right side shafts. The power required when the car is running is mainly output by the engine 9, and the power output by the engine 9 is input to the two output ends of the differential through the differential in two parts, and a part of the power is passed through the generator 7 connected to the left end of the differential. Generate electricity to charge the battery 10; another part of the power is output to the drive axle 11 through the rotor of the motor 8 and the transmission shaft, and then drives the wheels to travel. When this part of the power of the engine 9 cannot meet the driving demand (such as rapid acceleration), the electric motor 8 is controlled by the vehicle controller (ECU) 16 to meet the driving demand by supplementing the insufficient power. At this time, the generator 7 stores The electric energy stored in the storage battery 10 is output through the electric state of the motor 8 , that is to realize the joint driving of the engine 9 and the motor 8 . When braking and decelerating, the electric motor 8 can also act as a power generator, converting the kinetic energy of the vehicle into electric energy and storing it in the storage battery 10 . And when required power is relatively small (as running at a constant speed with a small load), the engine 9 is also regulated by the vehicle controller (ECU) 16 to find its best efficiency point work on the low power curve. The three power sources (engine 9, generator 7 and electric motor 8) that this power coupling device is connected all participate in the work during automobile running, and the power output of engine 9 is all controlled by vehicle controller (ECU) 16, makes It keeps operating at the best efficiency point on the power curve for different class sizes.

Referring to Fig. 6, the derivative device is designed to meet the needs of the vehicle running at a constant speed with a small load (required driving power is very small), and when the electric energy stored in the battery 10 is relatively sufficient, the vehicle controller 16 controls the electric control The clutch 27 is separated, the electronically controlled brake 26 is engaged, and the engine 9 and the generator 7 are controlled to be closed at the same time. The electric energy stored in the battery 10 is used to drive the motor 8 to rotate, thereby achieving pure electric driving of the vehicle. The vehicle controller 16 can control the motor 8 Outputting the power demand required by the vehicle. In other cases, the vehicle controller 16 controls the electronically controlled brake 26 to disengage and the electronically controlled clutch 27 to engage, and its working principle is exactly the same as that discussed above. The technical solution shown in Fig. 6 can realize the function of pure electric driving, and has better vehicle performance.

Test analysis:

Referring to Fig. 3, Fig. 4 and Fig. 5, what is shown in Fig. 3 and Fig. 4 is the rotational speed of each power source, the change rule of torque during a whole test process that adopts traditional differential as the power coupling device of hybrid electric vehicle to carry out Test data curve. During the test process, it includes the acceleration, average speed, and deceleration process of the low-speed section in the first half, and the acceleration, average speed, and deceleration process of the high-speed section in the second half. No matter in which part, the motor speed 18 follows the change law of the vehicle speed, and the engine is involved in the work, and the engine speed 19 and the engine operating torque 22 are adjusted to work at the best efficiency point by the vehicle controller 16 . Judging from the speed variation curve (refer to Fig. 3), the acceleration, constant speed and deceleration process of the engine speed 19 in the low speed section, and most of the acceleration process, uniform speed process and deceleration process in the high speed section are all controlled at the best stable The speed point works, that is, it is isolated from the vehicle speed change, and the motor speed 18 is made to follow the vehicle speed change by controlling the generator speed 20 . In the second half of the acceleration process in the high-speed section, due to the increase in the required load power, the vehicle controller 16 adjusts the optimum efficiency point of the engine to increase to a higher power, that is, the engine speed 19 increases correspondingly to adapt to the road load power. Require. Since the engine speed 19 is controlled to work at the best efficiency point, its speed is isolated from the vehicle speed, which automatically realizes a function similar to the traditional continuously variable transmission, so that the engine works stably at the best efficiency point, and the fuel consumption and emissions can be significantly reduced. In addition, judging from the torque change curves of each power source (refer to Fig. 4), during the acceleration process (whether it is a low-speed section or a high-speed section), the engine operating torque 22 gradually increases (its speed is adjusted to a stable point) to To adapt to the road load power requirements, at this time, because a part of the power output by the engine operating torque 22 is charged to the generator 7, as shown in the curve of the generator operating torque 23, when the engine operating torque 22 cannot meet the required road load power requirements At this time, it is supplemented by the motor output motor operating torque 21. During the braking deceleration process, the electric motor 8 can also act as a power generator to regenerate the kinetic energy of the whole vehicle by braking energy.

Referring to Fig. 5, Fig. 5 shows the comparison curves of the relationship between the rotation speeds of each shaft during the above-mentioned whole test process using the traditional differential as the power coupling device of the hybrid electric vehicle. During the whole process, the three-terminal rotational speed of the traditional differential coupling device satisfies the following relationship, twice 25 of the engine rotational speed is just the sum 24 of the rotational speed of the generator and the rotational speed of the electric motor. It is just this relationship of the traditional differential that the motor speed 18 changes with the vehicle speed, while the engine 9 is controlled to work at the optimum speed point, all adjusted by the speed of the generator 7 .

Derivative device test analysis:

Referring to Fig. 8 and Fig. 9, Fig. 8 and Fig. 9 show the test data curves of the rotational speed and torque variation law of each power source during another test using the derivative device as the hybrid electric vehicle power coupling device. In this test process, it also includes the acceleration, average speed, and deceleration process of the low speed section in the first half, and the acceleration, average speed, and deceleration process of the high speed section in the second half. In the acceleration process of the low-speed section, before accelerating to a certain vehicle speed, the vehicle controller 16 first judges that it is purely electric driving, controls the electronically controlled clutch 27 to disengage, and the electronically controlled brake 26 is engaged, and simultaneously shuts down the engine 9 and the generator 7 (at this time SOC is higher); when accelerating to a certain vehicle speed, the vehicle controller 16 requires the engine 9 to participate in work. At this time, the electronically controlled brake 26 is separated, the electronically controlled clutch 27 is engaged, and the engine speed 19 and the generator speed 20 increase thereupon; And in the high-speed section of second half, engine 9 works all the time. Due to the addition of pure electric driving functions, this control method can significantly reduce the fuel consumption and emissions of the vehicle.

In addition, it can also be seen from the curve in Fig. 9 that when the engine 9 is working, the output of the engine operating torque 22 and the generator operating torque 23 satisfy the following relationship: half of the engine operating torque 22 is output to the generator 7 to generate electricity, and the other half The torque is output to the motor 8 to drive the whole vehicle. This also uses the power transmission characteristics of the traditional differential to carry out automatic distribution. If half of the torque of the engine 9 can meet the torque requirements of the drive system, the motor 8 does not participate in work, and the generator 7 generates electricity and stores electric energy in the battery 10; If the driving torque requirement cannot be met, the electric motor 8 participates in the driving, releases the electric energy stored in the storage battery 10 by the generator 7, and jointly drives the whole vehicle to accelerate. When braking occurs, the electric motor 8 also has the function of generating electricity to recover braking energy. This driving characteristic realizes the series-parallel mode of a typical hybrid electric vehicle. Through a reasonable control strategy, the generator 7 converts half of the power output of the engine 9 into electric energy and stores it. In addition, the regenerative braking energy recovered by the electric motor 8 during the braking process, the two parts of energy can be provided for the next acceleration process of the electric motor 8. The energy involved in electric motoring can realize the balance of the SOC of the storage battery 10 .

The above analysis shows that using the differential as the power coupling device of the hybrid electric vehicle can realize the pure electric power of the hybrid electric vehicle, the engine 9 is working and charging, the engine 9 and the electric motor 8 are jointly driven, and the braking energy is recovered, etc. Typical hybrid electric vehicle driving model. And by adjusting the rotation speed of the generator 7, the motor 8 can keep the engine 9 working at the optimum rotation speed and torque point while the vehicle speed is maintained, thereby greatly improving the economic performance of the vehicle.

Claims (4)

1. A power coupling device for a hybrid vehicle, characterized in that the power coupling device adopts a traditional differential, and the left side gear (1) and the right side gear (2) of the differential ) are respectively connected to the generator (7) and the motor (8) through the left and right half shafts, the driving gear (6) of the main reducer is fixedly connected to the output shaft of the engine (9), and the driving gear (6) of the main reducer It meshes with the driven gear (3) of the main reducer in a state where the rotation axes of the two are coplanar and perpendicular to each other. The driven gear (3) of the final reducer and the left side shaft gear (1) are on the same rotation axis. The driven gear (3) of the main reducer drives the planetary gear (4) meshed with the left side gear (1) and the right side gear (2) around the left side gear (1) and the right side gear (2) through the cross shaft (5). The axis of the right side gear (2) rotates, the output shaft of the motor (8) is connected to the drive axle (11) through the transmission shaft, and drives the wheels (12) to travel; the engine (9), the generator (7) and the motor (8) respectively installed on the chassis of the car. 2. According to the power coupling device for hybrid electric vehicle according to claim 1, it is characterized in that, on the input shaft on the left side of the motor (8), an electronically controlled clutch (27) and an electronically controlled brake are sequentially installed from right to left (26), they are respectively connected with the vehicle controller (16) with signal lines. 3. according to claim 1 or 2 described power coupling devices for hybrid electric vehicles, it is characterized in that, the switch of control engine (9), the engine controller ( 17), the generator controller (14) and the motor controller (13) that control the switch, rotating speed and load torque of the generator (7) and the motor (8) are installed on the chassis of the automobile; The engine controller (17) is connected with a signal line, and the generator (7), generator controller (14), storage battery (10) installed on the chassis of the vehicle, the motor controller (13) and the motor (8) are connected with cables in turn. line connection; the vehicle controller (16) with unified coordination and control engine controller (17), generator controller (14) and motor controller (13) is installed on the vehicle, and the vehicle controller (16) is respectively Connect with engine controller (17), generator controller (14) and motor controller (13) with signal line, the starter (15) that control engine (9) is opened is installed on the chassis of automobile. 4. according to the power coupling device that hybrid electric vehicle is used according to claim 3, it is characterized in that, on the vehicle controller (16), the unified coordination and control engine controller (17), generator controller of self-editing are housed (14) and the computer program device of the motor controller (13), under the control of the vehicle controller (16), as the traditional differential of the power coupling device of the hybrid electric vehicle, the engine (9), the generator (7) The following work flow has been realized with the electric motor (8): 1) The vehicle controller (16) checks the cycle speed of the last time step; 2) The vehicle controller (16) checks the current time step cycle speed; 3) The vehicle controller (16) receives the state signals of each assembly of the current drive system; 4) The vehicle controller (16) calculates road load torque requirements and rotational speed requirements according to the current cycle speed and current acceleration; 5) Calculate the motor speed according to the road load speed demand; 6) According to the assembly state signals such as road load power demand and battery (10) power state, calculate the engine (9) optimal operating point speed and torque, and the vehicle controller (16) outputs the state to the engine controller (17) instruction; 7) According to the relational formula of differential speed and torque: 2ω _e =ω _g +ω _m ${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}$ ${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}$ In the formula: ω _e , ω _g , ω _m --- respectively engine speed, generator speed and motor speed; T _e , T _g , T _m , T _L -- respectively, the output torque of the engine, the generating torque of the generator, the electric torque of the motor and the load torque; Since the engine (9) optimal operating point speed and torque are calculated and determined in step 6), the speed and torque of the generator can be calculated, and the vehicle controller (16) outputs a state command to the generator controller (14); 8) Calculate the motor torque according to the road load torque requirement and the above formula, and connect the motor speed determined in step 5), and the vehicle controller (16) outputs a state command to the motor controller (13); 9) Determine whether the loop is over, if the loop is not over, repeat the above steps.

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