CN102815198B - Mixed power automobile driving system based on variable transmission - Google Patents

Abstract

The present invention provides a hybrid electric vehicle drive system based on continuously variable transmission, including an internal combustion engine, a dual-mass flywheel, a planetary gear mechanism, a forward clutch, a reverse brake, a drive motor, a motor controller, a battery, a continuously variable transmission mechanism, Reducer mechanism and differential assembly. The continuously variable transmission mechanism includes a driving pulley, a driven pulley, a metal belt, and an electric oil pump, and is integrated with a driving motor, a planetary gear mechanism, a forward clutch, a reverse brake, a speed reducer mechanism and a differential assembly as a hybrid special CVT. The continuously variable transmission mechanism cancels the hydraulic torque converter, and the power of the internal combustion engine is transmitted to the continuously variable transmission mechanism through the dual-mass flywheel; the drive pulley shaft is integrated with a drive motor, and an electric oil pump is used to provide hydraulic system pressure. Its low-speed pure electric, cancellation of idling, reduction of engine displacement, motor assist, engine steady-state operation, braking energy recovery and other key energy-saving technologies of hybrid electric vehicles can be well realized.

Description

Driving system of hybrid electric vehicle based on continuously variable transmission

technical field

The invention belongs to the field of hybrid electric vehicles, and relates to a driving system of a hybrid electric vehicle using fuel oil and electric energy as power sources, in particular to a driving system of a hybrid electric vehicle based on continuously variable transmission with pure electric starting and running functions.

Background technique

The development of energy-saving and new energy vehicles has become an inevitable choice for my country's energy strategy. The current focus is to promote the industrialization of pure electric vehicles and plug-in hybrid vehicles, popularize non-plug-in hybrid vehicles and energy-saving internal combustion engine vehicles, and upgrade my country's automobile industry. overall technical level.

The speed ratio of the continuously variable transmission can be changed continuously within a certain range. If it is used in the transmission of hybrid electric vehicles, the operating point of the engine can be flexibly adjusted according to the state of the vehicle, so that the engine can work in a region with high fuel efficiency, thereby improving the efficiency of the vehicle. Fuel economy and lower emissions. Currently, continuously variable transmissions have become the most widely used transmission scheme for mass-produced hybrid electric vehicles. Judging from the current status of foreign application development, the automatic transmission of hybrid electric vehicles has the characteristics of power transmission integration, that is, the motor and gearbox are integrated together, the system structure is more compact, the power transmission is more stable, and the control performance is better. It has been applied to most mass-produced hybrid vehicles.

The most successful hybrid car on the market is the Toyota Prius. Its THS hybrid system adopts a dual-motor structure, and the engine uses the Atkinson cycle with high fuel efficiency. The engine is always working at a high efficiency point through the control of the motor, and The hybrid system also features pure electric driving. However, its powertrain has complex structure, large volume and high cost. Another successful hybrid model on the market is Honda Insight/Civic. Its IMA system has a simple structure, the engine and the motor are coaxially connected in parallel, and the motor assists to ensure the power performance during acceleration; the use of a smaller displacement engine improves the load rate and fuel consumption. Efficiency; the use of ISG motors realizes the idle stop function and reduces fuel consumption. However, since the motor rotor and the engine crankshaft are fixedly connected together, the engine is dragged and rotated during pure electric driving, causing unnecessary losses, and does not have the function of long-term, high-efficiency pure electric driving.

For example, patent document CN101152837A discloses a hybrid driving device.

The hybrid driving device includes an engine, a starter generator, a clutch, a transmission mechanism, a motor generator and an energy storage system. The rotor of the starter generator is connected to the output shaft of the engine, the clutch is connected between the rotor shaft of the starter generator and the input shaft of the speed change mechanism, the rotor shaft of the motor generator is connected to the output shaft of the speed change mechanism, and the output shaft of the speed change mechanism transmitted to the wheels through the transmission mechanism. Since the power distributing mechanism with a complex structure is eliminated, the hybrid driving device of the present invention has a simple and compact structure and relatively flexible arrangement. In addition, since there is no complicated energy conversion, the energy utilization efficiency is high, and it has better comprehensive performance, including vehicle dynamics, fuel economy and emission characteristics, etc. are all improved.

When the hybrid driving device is driven by the engine alone, the power of the engine is directly transmitted to the wheels through the starter generator, clutch, transmission mechanism and transmission mechanism; when the motor generator is driven alone, the power of the motor generator passes through the output shaft of the transmission mechanism And the transmission mechanism is transmitted to the wheels; when the engine and the motor generator are jointly driven, the power of the two is combined on the output shaft of the transmission mechanism and transmitted to the wheels through the transmission mechanism; when the car is decelerating or braking, the motor generator acts as a power generator The engine performs regenerative regenerative braking to convert the inertial energy of the vehicle into electrical energy.

The hybrid driving device can realize many functions of hybrid electric vehicles, especially the high-efficiency pure electric driving function, but the output torque of the motor does not pass through the speed change mechanism during pure electric driving, and the output torque is limited. The moment is too small. In order to realize the functions of idling stop and automatic restart of the engine, the drive device adds a starter generator between the engine and the clutch, which complicates the structure.

In summary, the shortcomings of the hybrid drive device mainly include the following two points: first, the torque of the motor generator has not been decelerated and increased by the transmission mechanism, so it is not suitable for pure electric starting; second, it uses two motor generators and starter generators A motor with a complex structure.

The market is in urgent need of a drive system for a hybrid electric vehicle that has a simple structure and can realize high-efficiency pure electric starting and running functions.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a simple and efficient driving system for hybrid electric vehicles, so as to realize high-efficiency pure electric starting and driving functions.

In order to solve the above technical problems, the technical solution adopted by the present invention is: provide a hybrid electric vehicle drive system based on continuously variable transmission, including an internal combustion engine, a drive motor, a battery, a reduction mechanism, a differential assembly, a continuously variable transmission The transmission mechanism and the reversing mechanism are characterized in that,

The reversing mechanism includes a planetary gear mechanism, a forward gear clutch, and a reverse gear brake. The reversing mechanism is used to connect the internal combustion engine and the drive motor, and can disconnect the internal combustion engine and the drive motor during pure electric driving, so as to achieve Efficient driving functions;

The internal combustion engine is connected to the planetary carrier of the planetary gear mechanism, and the forward and reverse functions in the engine mode can be realized by controlling the disconnection and engagement of the forward clutch and the reverse brake;

One end of the drive motor is connected to the sun gear of the planetary gear mechanism, the other end is connected to the driving pulley of the continuously variable transmission mechanism, and is connected to the battery through a motor controller to provide power. When the power is low, the motor is used to drive the vehicle for pure electric driving, and the reversing function with low power demand is directly realized through the reverse rotation of the motor.

It is also characterized in that the continuously variable transmission mechanism uses an electric oil pump to provide oil pressure to the electro-hydraulic servo system, so that during low-speed pure electric driving, the electric oil pump can directly increase the speed of the driving motor from zero without the assistance of the internal combustion engine. By providing pressure to the hydraulic system, the driving torque can be smoothly transmitted from the driving pulley to the driven pulley, and then drive the vehicle.

In order to realize the pure electric reversing function, the drive motor is a disc permanent magnet motor with two-way rotation function, the rated power of the drive motor is 10-15 kW, and the battery uses a lithium battery with a capacity of 5-10 kWh. ion battery.

In order to reduce vibration and facilitate the operation of the engine, a set of double-mass flywheels is also included, and the internal combustion engine is connected with the planet carrier in the planetary gear mechanism through the double-mass flywheels.

The technical scheme adopted in the present invention is further described below: the hybrid electric vehicle drive system based on continuously variable transmission, including an internal combustion engine, a dual-mass flywheel, a planetary gear mechanism, a forward gear clutch, a reverse gear brake, a drive motor, a motor controller, Battery, continuously variable transmission mechanism, reducer mechanism and differential assembly. The continuously variable transmission mechanism includes a driving pulley, a driven pulley, a metal belt, and an electric oil pump, which are integrated with a driving motor, a planetary gear mechanism, a forward clutch, a reverse brake, a speed reducer mechanism, and a differential assembly. Hybrid-specific CVT.

The internal combustion engine is connected with the planetary carrier of the planetary gear mechanism in the special hybrid continuously variable transmission through a set of dual-mass flywheels, and the forward and reverse functions in the engine mode are realized through the control of the brake and the clutch. The drive motor adopts a disc permanent magnet motor, one end of which is connected to the sun gear of the planetary gear mechanism, and the other end is connected to the driving pulley of the continuously variable transmission mechanism. Electric driving. The reversing function with low power requirements is realized directly through the reverse rotation of the motor. When the required power of the whole vehicle is moderate, it is driven by a pure internal combustion engine. If the battery power is low, the motor can work in the power generation state to charge the battery. If the required power of the whole vehicle is large, the electric motor provides auxiliary power while the internal combustion engine is working.

Compared with the traditional continuously variable transmission vehicle, this system only needs to add a motor and a set of batteries, and after canceling the hydraulic torque converter of the traditional continuously variable transmission, the structure of the powertrain is simple and compact, and the operation reliability is high . The system has a variety of operating modes, which can realize pure electric drive, engine and electric motor parallel drive, engine charging mode, regenerative braking mode, engine independent drive mode, etc.

This system absorbs the advantages of simple structure of the single-shaft parallel hybrid power system, and can easily realize the motor assist function. Even if a small-displacement engine is used, the power performance of the vehicle can still be improved; The lack of hybrid power, especially the planetary gear mechanism placed between the engine and the motor, the flexible connection between the engine and the motor can be realized by controlling the clutch and brake, which is convenient for realizing high-efficiency pure electric starting and driving functions, which can be used for hybrid electric vehicles Significantly improve fuel economy and vehicle dynamic performance.

Description of drawings

FIG. 1 is a schematic diagram of the system structure of an embodiment of the present invention.

In the above attached drawings:

1-internal combustion engine; 2-dual-mass flywheel; 3-planetary gear mechanism; 4-forward clutch; 5-reverse brake; 6-drive motor; 7-motor controller; 8-battery; 9-electric oil pump; 10- Drive pulley; 11-metal belt; 12-driven pulley; 13-reduction mechanism; 14-differential assembly; 15-hybrid special continuously variable transmission.

detailed description

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

With reference to shown in accompanying drawing 1, a kind of hybrid electric vehicle drive system based on continuously variable transmission described in the present invention comprises internal combustion engine 1, dual-mass flywheel 2, planetary gear mechanism 3, forward gear clutch 4, reverse gear brake 5, driving Motor 6, motor controller 7, battery 8, electric oil pump 9, driving pulley 10, metal belt 11, driven pulley 12, reduction mechanism 13, differential gear assembly 14. Wherein the components except the internal combustion engine 1, the dual-mass flywheel 2, the motor controller 7 and the battery 8 are integrated together to form a continuously variable transmission 15 for hybrid power.

The internal combustion engine 1 is connected to the planetary carrier of the planetary gear mechanism 3 in the special hybrid continuously variable transmission 14 through a group of dual mass flywheels 2, and one end of the drive motor 6 is connected to the sun gear of the planetary gear mechanism 3, and the other end is connected to the sun gear of the planetary gear mechanism 3. The driving pulley 10 of the continuously variable speed transmission mechanism is connected to each other, and is connected to the battery 8 through a motor controller 7 to provide power. The driving pulley 10 drives the driven pulley 12 through the metal belt 11, and passes through the reduction mechanism 13, The differential gear assembly 14 outputs power to the wheels to drive the vehicle.

The internal combustion engine 1 can be a gasoline engine or a diesel engine. If a gasoline engine is selected, it is recommended to use a gasoline engine whose working cycle is an Atkinson cycle or a turbocharged gasoline engine.

The planetary gear mechanism 3 together with the forward clutch 4 and the reverse brake 5 form a reversing mechanism. During pure electric driving, the forward gear clutch 4 and the reverse gear brake 5 are all in the disconnected state, the planetary carrier is in a free state, and the engine will not be dragged to rotate, thereby realizing high-efficiency pure electric driving.

The continuously variable transmission mechanism uses an electric oil pump 9 to provide oil pressure to the electro-hydraulic servo system. Therefore, when the motor controller 7 controls the speed of the drive motor 6 to gradually increase from zero during low-speed pure electric driving, since the electric oil pump 9 can provide pressure to the hydraulic system, the drive torque can be smoothly transmitted from the driving pulley 10 to the driven pulley. The pulley 12 then drives the vehicle to travel.

The drive motor 6 adopts a disc-type permanent magnet motor (brushless DC motor or permanent magnet synchronous motor), which has the function of bidirectional rotation, and the reversing function during pure electric driving can be realized directly through the reverse rotation of the motor. Pure electric driving will be used when the power demand of the whole vehicle is low. Compared with the pure electric vehicle, the motor power and the battery capacity of the hybrid vehicle of the present invention can be correspondingly reduced. For the characteristics of the hybrid vehicle, the rated power of the motor is generally selected at 10-15 kilowatts. 5-10kw.h lithium-ion battery.

The internal combustion engine 1 is connected to a planetary gear 3 via a dual-mass flywheel 2 . The dual-mass flywheel can play the role of damping, which is beneficial to the work of the engine. When the driving power demand of the whole vehicle is moderate, the working mode of the internal combustion engine will be adopted. At this time, the forward gear clutch 4 is controlled to engage, and the power of the internal combustion engine passes through the dual-mass flywheel to the planetary gear mechanism and then to the driving pulley 10, and drives the vehicle after being torque-changed by the continuously variable transmission mechanism. drive. Under the internal combustion engine working mode, if it is necessary to perform reverse, the forward gear clutch 4 is controlled to be disconnected, the reverse brake 5 is engaged, the large ring gear is fixed, the torque is transmitted from the planetary carrier to the sun gear, and the steering is changed at the same time, thereby realizing the reverse function.

When the driving system of the hybrid electric vehicle of the present invention requires a large amount of driving power, the motor controller 7 controls the driving motor 6 to work in an electric state while the engine drives the vehicle, and the two jointly drive the vehicle.

In the internal combustion engine working mode, when the power of the battery 8 is lower than a certain lower limit, the motor controller 7 controls the driving motor 6 to work in a power generation state, and part of the power provided by the internal combustion engine 1 will be used to charge the battery 8 .

When the vehicle decelerates or brakes, the motor controller 7 controls the driving motor 6 to work in the power generation state, charges the battery 8, converts mechanical energy into electrical energy, and realizes braking energy recovery.

The driving system of the hybrid electric vehicle of the present invention improves the fuel economy when driving at low speed (low power demand) through the high-efficiency pure electric driving of the driving motor 6 . The working mode of the internal combustion engine is adopted for medium power demand, and at the same time, the speed ratio of the continuously variable transmission is matched according to the best economic law, so that the fuel efficiency of the internal combustion engine 1 is always relatively high when it is working. When the internal combustion engine 1 is working, if the power of the battery 8 is lower than a certain lower limit, then consider making the motor 6 work in the power generation state to increase the load rate of the internal combustion engine while maintaining the relative balance of the battery power, so that the overall efficiency of the vehicle power system can be optimized. When high power is required, the motor 6 provides auxiliary power while the internal combustion engine 1 is working, which better meets the power performance requirements of the vehicle.

In general, the drive system of the hybrid electric vehicle of the present invention is simple in structure, can realize various functions of the hybrid electric vehicle, and can better meet the requirements of the hybrid electric vehicle on fuel economy and power performance, and is especially suitable for plug-in type hybrid vehicles.

Claims (3)

1. a kind of mixed power automobile driving system based on variable transmission, including internal combustion engine (1), motor (6), electricity Pond (8), reducing gear (13), differential assembly (14), infinitely variable speed gearing and changement, it is characterised in that

The changement includes planetary gears (3), forward gear clutch (4), reverse gear brake (5)；

The internal combustion engine (1) is connected with the planet carrier of the planetary gears (3), and can be by the drive shift clutch The function of the advance and reversing under engine mode is realized in the disconnection of device (4) and reverse gear brake (5), Engagement Control；

Described motor (6) one end is connected with the sun gear of planetary gears (3), the other end and the variable transmission The driving pulley (10) of mechanism is connected, and is connected by an electric machine controller (7) with the battery (8) to provide power, when whole When car traveling demand power is small, pure motor driving is carried out using motor-driven vehicle, the car-backing function of low-power requirements is straight Connected motor reversal realization；

The changement, motor (6), infinitely variable speed gearing, reducing gear (13), differential assembly (14) are integrated The special ST of hybrid power (15) is formed together；The infinitely variable speed gearing uses electric oil pump (9) Oil pressure is provided to electrohydraulic servo system；

When vehicle deceleration or braking, electric machine controller (7) control motor (6) is operated in generating state, is filled to battery (8) Electricity, mechanical energy is converted into electric energy, realizes Brake energy recovery.

2. the mixed power automobile driving system according to claim 1 based on variable transmission, it is characterised in that institute It is the disc-type permanent magnet motor with Double-directional rotary function to state motor (6), the rated power of the motor (6) for 10~ 15 kilowatts, the battery (8) uses lithium ion battery of the capacity for 5~10 kilowatt hours.

3. the mixed power automobile driving system based on variable transmission according to any one in claim 1~2, Characterized in that, also including one group of double mass flywheel (2), the internal combustion engine (1) passes through the double mass flywheel (2) and planet tooth Planet carrier in wheel mechanism (3) is connected.