CN113212141B - Electro-hydraulic hybrid drive system for extended-range vehicles - Google Patents

Abstract

The present invention provides an electro-hydraulic hybrid drive system for a range-extended vehicle and a control method thereof, comprising: an engine, an engine brake, an engine clutch, a first generator, a first brake, a planetary gear mechanism, a second generator, and a second brake , The second clutch, the second hydraulic oil pump, the drive motor, the transmission input shaft coupling gear, the transmission, the transmission output shaft coupling gear, the transmission output shaft hydraulic drive gear, the fourth clutch, the third clutch, the transmission input shaft Hydraulic drive gear, drive hydraulic motor, working hydraulic motor, solenoid valve, second relief valve, second check valve, first relief valve, first check valve, first hydraulic oil pump, first clutch, range extender Drive control unit, hydraulic oil tank assembly, accumulator. Using the mechanical coupling relationship of the planetary gear train and the principle of power splitting, the planetary gear train and two sets of generators are used to dynamically adjust the working states of the engine and the two sets of generators.

Description

Electro-hydraulic hybrid drive system for extended-range vehicles

technical field

The invention relates to the field of hydraulic systems for extended-range vehicles, in particular to an electro-hydraulic hybrid drive system for extended-range vehicles.

Background technique

In the occasions of frequent heavy-load starting, heavy-load climbing, frequent heavy-load start-stop, non-road heavy-load low-speed driving conditions, or vehicles with hydraulic operation equipment on the vehicle and often low-speed high-power operations, these are suitable and equipped with Vehicles with extended-range architecture often have the following problems in the above working scenarios: 1. Insufficient starting power. In order to start normally, they are usually equipped with larger drive motors or gearboxes with more gears; 2. When shifting gears during heavy load climbing Power interruption is prone to the risk of slippage; 3. When the driving hydraulic system is working, an additional motor is required to drive the hydraulic pump, and the system is complex and costly; 4. It is necessary to pay attention to the energy efficiency optimization and Coordination, that is, the range-extending system needs an optimal combination of driving efficiency, operation-driving efficiency, and range-extending power generation system efficiency. However, the traditional range-extending vehicle has a decentralized and distributed design, which is difficult to achieve. Realize the comprehensive optimization function of extended range performance. Typical range-extending vehicles include: mining/site heavy-duty dump trucks, high-power sanitation vehicles (sweeping, watering, high-pressure cleaning, fog cannon dust removal), concrete mixer trucks, construction machinery (excavators, forklifts), fire truck etc. To sum up, the characteristics of the extended-range architecture requirements for these vehicles or scenarios are:

1. The high-efficiency area of the power generation system should be wide, which can meet a wide range of high-efficiency output requirements

2. There is a need for hydraulic operation, and a hydraulic system is required to participate in power distribution

3. Low-speed operation mode, low speed, frequent start and stop

4. When starting with great resistance or starting from a slope, peak driving torque compensation is required, and the motor or gearbox cannot be increased indefinitely.

5. The power is not interrupted or less interrupted to prevent drive failure

6. The power generation is not interrupted, and the power generation function must coexist with driving and operation, but it needs to adopt a subtractive integrated design

7. The original functions of the extended-range vehicle should be maintained, such as motor braking to recover energy, no idling start, smooth start with little impact of power interruption, extended-range power generation to meet normal driving needs, pure electric driving and work, etc.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above shortcomings of the prior art, and to provide a range-extended vehicle electro-hydraulic hybrid drive system that satisfies the requirements of low drive failure risk, high energy conversion rate, and high energy utilization efficiency.

In order to achieve the above purpose, the range-extended vehicle electro-hydraulic hybrid drive system of the present invention is as follows:

The main feature of the range-extended vehicle electro-hydraulic hybrid drive system is that the system includes an engine, an engine brake, an engine clutch, a first generator, a first brake, a planetary gear mechanism, a second generator, a second brake, Second clutch, second hydraulic oil pump, drive motor, gearbox input shaft coupling gear, gearbox, gearbox output shaft coupling gear, gearbox output shaft hydraulic drive gear, fourth clutch, third clutch, gearbox input shaft hydraulic pressure Drive gear, drive hydraulic motor, working hydraulic motor, solenoid valve, second relief valve, second check valve, first relief valve, first check valve, first hydraulic oil pump, first clutch, range extender drive The control unit, hydraulic oil tank assembly, accumulator, and the double-generator coupled double-hydraulic oil pump based on the principle of planetary gear train coupling, optimize and match the working state of the two sets of generators. The coupling system and the dual-clutch driving coupling system constitute an electro-hydraulic hybrid driving relationship between the range-extending system and the driving system of the range-extending vehicle, which includes both power transmission coupling and hydraulic torque coupling.

Preferably, when the moving parts in the planetary gear train are connected to the generator and the hydraulic oil pump at the same time, the torque acting on the gear train parts is positively coupled by the generator torque and the hydraulic oil pump torque. The generator and the hydraulic oil pump synchronously participate in the torque/speed coupling and power split mechanism of the planetary gear train. When the load of the hydraulic oil pump changes, the generator performs the load change balance compensation.

Preferably, in the described system, the ring gear of the first generator planetary gear mechanism is connected, the second generator is connected with the sun gear, the planet carrier is connected with the engine through the engine clutch, and the first hydraulic oil pump is connected with the first hydraulic oil pump through the first clutch. The generator forms a transmission connection relationship, and the second hydraulic oil pump is connected with the second generator through the second clutch.

Preferably, according to the state control of the third clutch and the fourth clutch, the system realizes the coupling of the power of the hydraulic motor from the transmission input shaft or the transmission output shaft through two sets of coupling gears, respectively. , the two sets of clutches cannot be combined at the same time.

Preferably, the oil input ports of the two groups of hydraulic oil pumps in the system are connected to the hydraulic oil tank. The accumulator at the output port of the valve is connected in parallel with the input port of the solenoid valve No. 4, the output port of the first one-way valve is directly connected to the input port of the solenoid valve No. 3, and the three-position four-way solenoid valve has two confluence functions and one diversion function. It realizes the functions of simultaneously driving the hydraulic driving motor and the working driving motor, interrupting the hydraulic power of the motor of one circuit, and the dual pumps jointly driving the same hydraulic motor. Among them, the accumulator can buffer the pressure pulsation shock in the hydraulic circuit, and can form a gradually controllable and stable hydraulic power output together with the hydraulic oil pump.

Preferably, the system is implemented by the extended-range drive control unit to realize the control functions of the generator, clutch, brake and solenoid valve, and at the same time cooperate with the engine, drive motor system, gearbox system or other systems of the vehicle to complete the logic control of the power system. Function.

Preferably, the system has three power generation modes. According to the working principle of the planetary gear train mechanism, through the strategic control of the range-extending drive control unit, the high-efficiency power working area expansion of the power generation system is realized, that is, two single-motor power generation modes and 1 dual-motor generating mode.

Preferably, the system has three starting modes. By controlling the brakes and clutches, cooperating with the vehicle energy storage system, and through the strategic control of the extended-range power control unit, two single-motor starting modes and one dual-motor starting mode are formed. .

Preferably, the system has four hydraulic oil pump drive modes, and by controlling the speed of brakes, clutches, generators, and engines, four hydraulic oil pump drive modes are formed, namely, single-motor drive mode, dual-motor joint drive mode, and dual-motor drive mode. Motor independent drive mode and dual motor coordinated drive mode.

Preferably, the system has three hydraulic coupling modes, and three hydraulic coupling modes are formed by controlling the hydraulic oil pump and the solenoid valve, namely, independent hydraulic mode, combined hydraulic mode and exchange hydraulic mode.

Preferably, the system has eight modes in which hydraulic power participates in driving, and through the state control and operating conditions of the dual clutch, 8 modes in which hydraulic power participates in driving are formed, namely, the front-end motor linkage mode, the rear-end output Linkage Mode, Launch Assist Mode, Shift Assist Mode, Slope Prevention Assist Mode, Park Mode, Limp Mode and Isolation Mode.

The range-extended vehicle electro-hydraulic hybrid drive system of the present invention is adopted to expand the range and distribution of the high-efficiency working area of the multi-cylinder engine power generation system, so as to improve the coverage of the dynamic and economical working conditions of the power generation system, especially to solve the problem that the high-power engine power generation system is continuously small Economic issues in the state of power generation demand. The invention improves the starting or passing ability of the vehicle under severe working conditions, and utilizes an integrated hydraulic unit for hydraulic power coupling to compensate for the peak demand of driving force. Through the power coupling of the hydraulic drive unit, the invention realizes a stable start at a low speed, and at the same time, it can compensate for the interruption of shifting power and optimize the impact feeling of shifting. The present invention reduces the risk of driving failure by increasing the hydraulic drive unit to increase the hydraulic starting and anti-slope functions and the gear shifting and anti-slope functions. The invention integrates the hydraulic drive unit, one machine has multiple functions, that is, it can also drive the bodywork equipment to work while generating electricity, which improves the system integration degree and improves the energy conversion efficiency because the design of the hydraulic motor driven by a separate motor is reduced. The invention improves the energy efficiency coordination capability of the range extension system, that is, through the coupling principle of the double generator and the planetary mechanism, power generation and operation can be efficiently coupled, and the energy utilization efficiency can be improved.

Description of drawings

FIG. 1 is a schematic diagram of an electro-hydraulic hybrid drive system for an extended-range vehicle of the present invention.

Reference number:

1 engine;

2 engine brakes;

3 engine clutch;

4 the first generator;

5 the first brake;

6 planetary gear mechanism;

7 the second generator;

8 Second brake;

9 second clutch;

10 The second hydraulic oil pump;

11 drive motor;

12 Gearbox input shaft coupling gear;

13 gearbox;

14 Gearbox output shaft coupling gear;

15 Gearbox output shaft hydraulic drive gear;

16 Fourth clutch;

17 The third clutch;

18 Gearbox input shaft hydraulic drive gear;

19 Drive the hydraulic motor;

20 working hydraulic motor;

21 Solenoid valve;

22 The second relief valve;

23 The second check valve;

24 The first relief valve;

25 The first one-way valve;

26 The first hydraulic oil pump;

27 The first clutch;

28 Extended range drive control unit;

29 hydraulic oil tank assembly;

30 accumulators.

Detailed ways

In order to describe the technical content of the present invention more clearly, further description will be given below with reference to specific embodiments.

The range-extended vehicle electro-hydraulic hybrid drive system of the present invention includes an engine, an engine brake, an engine clutch, a first generator, a first brake, a planetary gear mechanism, a second generator, a second brake, a second clutch, a first Two hydraulic oil pump, drive motor, gearbox input shaft coupling gear, gearbox, gearbox output shaft coupling gear, gearbox output shaft hydraulic drive gear, fourth clutch, third clutch, gearbox input shaft hydraulic drive gear, drive hydraulic Motor, working hydraulic motor, solenoid valve, second relief valve, second check valve, first relief valve, first check valve, first hydraulic oil pump, first clutch, range extension drive control unit, hydraulic oil tank The assembly, the accumulator, the double generator coupled with the double hydraulic oil pump based on the planetary gear coupling principle, optimizes and matches the working state of the two sets of generators. At the same time, through the double hydraulic source coupling system and double clutch The drive coupling system constructs an electro-hydraulic hybrid drive relationship between the range-extending system and the drive system of the range-extending vehicle, in which both power transmission coupling and hydraulic torque coupling are coupled.

As a preferred embodiment of the present invention, when the moving parts in the planetary gear train are connected to the generator and the hydraulic oil pump at the same time, the torque acting on the gear train parts is driven by the torque of the generator and the rotation of the hydraulic oil pump. The generator and the hydraulic oil pump synchronously participate in the torque/speed coupling and power shunt mechanism of the planetary gear train. When the load of the hydraulic oil pump changes, the generator performs the load change balance compensation.

As a preferred embodiment of the present invention, in the system, the ring gear of the first generator planetary gear mechanism is connected, the second generator is connected to the sun gear, the planet carrier is connected to the engine through the engine clutch, and the first hydraulic oil pump is connected to the engine through the first hydraulic oil pump. The clutch forms a transmission connection relationship with the first generator, and the second hydraulic oil pump is connected with the second generator through the second clutch.

As a preferred embodiment of the present invention, the system is controlled according to the state of the third clutch and the fourth clutch, and through two sets of coupling gears, the power of the hydraulic motor is coupled from the transmission input shaft or the transmission output shaft respectively. , During the driving process, the two sets of clutches cannot be combined at the same time.

As a preferred embodiment of the present invention, the oil input ports of the two groups of hydraulic oil pumps in the system are connected to the hydraulic oil tank, and the output ports of the two groups of hydraulic oil pumps are respectively provided with the input end of the relief valve and the input end of the check valve in parallel , the accumulator at the output port of the second check valve is connected in parallel with the input port No. 4 of the solenoid valve, the output port of the first check valve is directly connected to the input port No. 3 of the solenoid valve, and the three-position four-way solenoid valve is connected through two confluence functions and One diversion function realizes the functions of driving the hydraulic drive motor and the operation drive motor at the same time, interrupting the hydraulic power of the motor in one circuit, and the dual pumps jointly driving the same hydraulic motor. Among them, the accumulator can buffer the pressure pulsation shock in the hydraulic circuit, and can form a gradually controllable and stable hydraulic power output together with the hydraulic oil pump.

As a preferred embodiment of the present invention, the system realizes the control functions of the generator, clutch, brake and solenoid valve by the range extension drive control unit, and at the same time cooperates with the engine, drive motor system, gearbox system or other systems of the vehicle to complete the power The logic control function of the system.

As a preferred embodiment of the present invention, the system has three power generation modes. According to the working principle of the planetary gear train mechanism, through the strategic control of the range-extending drive control unit, the efficient power working area expansion of the power generation system is realized, that is, two single power generation modes are formed. Motor power generation mode and 1 dual motor power generation mode.

As a preferred embodiment of the present invention, the system has three starting modes. By controlling the brakes and clutches, cooperating with the vehicle energy storage system, and through the strategic control of the extended-range power control unit, two single-motor starting modes and one starting mode are formed. Dual motor starting mode.

As a preferred embodiment of the present invention, the system has four hydraulic oil pump drive modes. By controlling the speed of brakes, clutches, generators, and engines, four hydraulic oil pump drive modes are formed, that is, a single motor drive mode, a dual motor drive mode, and a dual motor drive mode. Drive mode, dual-motor independent drive mode and dual-motor coordinated drive mode.

As a preferred embodiment of the present invention, the system has three hydraulic coupling modes. By controlling the hydraulic oil pump and the solenoid valve, three hydraulic coupling modes are formed, namely independent hydraulic mode, combined hydraulic mode and exchange hydraulic mode.

As a preferred embodiment of the present invention, the system has eight modes in which hydraulic power participates in vehicle driving. Through the state control and operating conditions of the dual clutch, 8 modes in which hydraulic power participates in vehicle driving are formed, that is, the front-end motor linkage mode , Rear output linkage mode, start assist mode, shift assist mode, anti-slope assist mode, parking mode, limp mode and isolation mode.

In a specific embodiment of the present invention, the present invention provides a range-extended vehicle electro-hydraulic hybrid drive system and a control method thereof, comprising: an engine, an engine brake, an engine clutch, a first generator, a first brake, a planetary gear mechanism, Second generator, second brake, second clutch, second hydraulic oil pump, drive motor, gearbox input shaft coupling gear, gearbox, gearbox output shaft coupling gear, gearbox output shaft hydraulic drive gear, fourth clutch, Third clutch, gearbox input shaft hydraulic drive gear, drive hydraulic motor, working hydraulic motor, solenoid valve, second relief valve, second check valve, first relief valve, first check valve, first hydraulic pressure Oil pump, first clutch, range extender drive control unit, hydraulic oil tank assembly, accumulator.

The engine may be referred to as ICE hereinafter, and the output shaft of the engine is connected to the planet carrier of the planetary gear mechanism through the engine brake and the engine clutch to transmit torque.

The engine brake may be referred to as B0 hereinafter, and the unlocking and locking functions can be realized by the control unit, so as to realize the free rotation and stop braking of the engine output shaft.

The engine clutch may be abbreviated as C0 hereinafter, which can realize the function of combining or separating through the control unit, so as to realize the power transmission after the engine output shaft and the planet carrier of the planetary gear mechanism are connected or disconnected after separation.

The first generator, hereinafter referred to as ISG1, has two functions of a generator and a motor, and its rotor part is connected to the ring gear of the planetary gear mechanism.

The first brake may be referred to as B1 hereinafter, and the unlocking and locking functions can be realized by the control unit, so as to realize the free rotation and stop braking of the ring gear of the planetary gear mechanism. The standard planetary gear transmission mechanism of the planetary gear mechanism includes a sun gear, a planetary gear, a ring gear and a planet carrier.

The second generator, hereinafter referred to as ISG2, has two functions of generator and motor, and the rotor part of which is connected to the sun gear of the planetary gear mechanism. The second brake may be referred to as B2 hereinafter, and the unlocking and locking functions can be realized by the control unit, so as to realize the free rotation and stop braking of the sun gear of the planetary gear mechanism. The second clutch may be referred to as C2 hereinafter, and can realize the function of combining or separating through the control unit, so that the ISG2 motor can obtain hydraulic power after being connected with the second hydraulic oil pump, or disconnect the power after separation.

The hydraulic power source of the second hydraulic oil pump vehicle is used to provide smooth hydraulic power. The input port comes from the hydraulic tank. The driving motor, the electric driving power source of the vehicle, provides the driving power of the vehicle. The transmission input shaft is coupled to a gear for coupling power from a driving hydraulic motor. The gearbox, the variable speed transmission mechanism of the vehicle, can provide power transmission or neutral power interruption function.

The transmission output shaft is coupled to a gear for coupling power from a driving hydraulic motor. The transmission output shaft hydraulically drives the gear for transmitting the power from the driving hydraulic motor. The fourth clutch may be referred to as C4 hereinafter. The combination or separation function can be realized through the control unit, so that the hydraulic drive motor can be connected with the hydraulic drive gear of the gearbox output shaft to obtain the hydraulic drive power or disconnect the power after separation.

The third clutch may hereinafter be referred to as C3. The combination or separation function can be realized through the control unit, so that the hydraulic drive motor can be connected with the hydraulic drive gear of the gearbox input shaft to obtain the hydraulic drive power or disconnect the power after separation.

The gearbox input shaft hydraulically drives the gear. Used to transmit power from the drive hydraulic motor. The driving hydraulic motor, the hydraulic power output, drives the load. The hydraulic input pipeline of the motor is connected to the No. 1 output port of the solenoid valve, and the hydraulic output pipeline of the motor is connected to the oil tank.

The working hydraulic motor, hydraulic power take-off, drives the load. The hydraulic input pipeline of the motor is connected to the No. 2 output port of the solenoid valve, and the hydraulic output pipeline of the motor is connected to the oil tank.

The solenoid valve, a three-position four-way valve, can realize combined driving or independent driving of dual input hydraulic power. Ports 1 and 2 of the solenoid valve are used as hydraulic power output ports, and ports 3 and 4 are used as hydraulic power input ports. The solenoid valve has three connection states: 3 and 4 input ports are connected to No. 1 output port, and No. 2 port is closed; 3, 4 input ports are connected to No. 2 output port, and No. 1 port is closed; No. 3 input port is connected to No. 2 At the same time, the No. 4 input port is connected to the No. 1 output port. The hydraulic power of the No. 4 input port comes from the second hydraulic oil pump through the one-way valve, and the hydraulic power of the No. 3 input port comes from the first hydraulic oil pump through the one-way valve.

The second relief valve, the pipeline pressure protection or limit maintenance valve, releases pressure and returns to the oil tank after the hydraulic oil exceeds the pressure limit. The relief valve is connected in parallel with the output port of the second hydraulic oil pump, and the other end is connected to the oil tank.

The second one-way valve prevents the reverse flow of hydraulic oil or reverse pressure transmission. The inlet is connected to the second hydraulic oil pump, and the liquid flow direction is opposite to the outlet of the second hydraulic oil pump.

The first relief valve is a pipeline pressure protection or limit maintenance valve, and the hydraulic oil is released and returned to the oil tank after the hydraulic oil exceeds the pressure limit. The relief valve is connected in parallel with the output port of the first hydraulic oil pump, and the other end is connected to the oil tank. The first one-way valve prevents the reverse flow of hydraulic oil or reverse pressure transmission. The inlet is connected to the first hydraulic oil pump, and the liquid flow direction is opposite to the outlet of the first hydraulic oil pump.

The first hydraulic oil pump. The hydraulic power source of the vehicle, used to provide smooth hydraulic power. The input port comes from the hydraulic tank. the first clutch. Hereinafter, it may be referred to as C1. The combination or separation function can be realized through the control unit, so that the hydraulic power can be obtained after the ISG1 motor is connected with the first hydraulic oil pump, or the power will be disconnected after separation.

The Range Extended Drive Control Unit (RDCU). Hereinafter, it may be referred to as RDCU for short. The total control system of the extended-range drive system can control the generator set, brake set, clutch set and solenoid valve, and has the function of communication and coordinated control with the engine system, drive motor system, transmission system and other vehicle control systems. It can be a single functional integrated assembly, or it can be decomposed into sub-control units of each component, and the functions are decomposed. The RDCU has an electrical connection and control relationship with the engine, each generator, each brake, each clutch, solenoid valve, drive motor, and gearbox, that is, the function of electrical signal or power current intercommunication.

The hydraulic oil tank assembly. It includes functions such as heat dissipation, filtration, liquid storage, and liquid replenishment. It provides hydraulic oil for the hydraulic oil pump and a return channel for the hydraulic motor and relief valve. the accumulator. The main role is to buffer and absorb pressure pulsations. It is connected before the No. 4 input port of the solenoid valve and is located after the second one-way valve, and provides a voltage stabilization function for the pipeline communicated with the No. 4 input port of the solenoid valve.

Using the mechanical coupling relationship of the planetary gear train and the principle of power splitting, the planetary gear train and two sets of generators are used to dynamically adjust the working states of the engine and the two sets of generators to achieve a high-efficiency working area under different power requirements of the power generation system. Extended effect. At the same time, according to the torque coupling relationship between the generator and the connected hydraulic oil pump, the torque balance principle of the planetary gear train is borrowed, and the torque balance compensation principle of the generator is used to realize the power generation and drive the hydraulic oil pump to work at the same time.

Furthermore, through the hydraulic coupling circuit, the power is directly transmitted to the drive system, which realizes the function of power superposition, greatly improves the backup power, and can also provide continuous hydraulic power output for the operating system.

Finally, the extended-range drive control unit is used to logically control the engine, generator, brake, clutch and solenoid valve to achieve the control and coordination of system components and the realization of the performance of the entire system.

Broaden the working condition coverage of the high-efficiency power of the power generation system, thereby improving the comprehensive economic performance of the power generation system; through the hydraulic power coupling, the starting or passing ability of the vehicle is improved, the smooth starting ability of the vehicle is improved, and the shift power interruption is compensated. The gear shifting experience is optimized and the hydraulic anti-slope ability is increased; after the electro-hydraulic power is mixed, the capacity of the motor or transmission can be appropriately reduced, reducing the size and cost of the electric power system; the composition of two sets of generators has a certain amount of power generation. Or drive function compensation, reducing the risk of complete failure of power generation or hydraulic drive; integrated design and control of the vehicle hydraulic system, one machine for multiple purposes, optimizes the power generation system and improves system integration and hydraulic transmission efficiency; use generators and hydraulic oil pumps The principle of torque coupling compensation improves the energy conversion efficiency of the range extension system.

The three components of the electro-hydraulic hybrid drive system are:

The extended-range hydraulic power system is composed of an extended-range engine, a generator set, a planetary gear mechanism, a clutch group, a brake group and a hydraulic oil pump group, and is responsible for providing the extended-range power generation and hydraulic power functions.

The electro-hydraulic hybrid drive system consists of a drive motor, a drive hydraulic motor, a work hydraulic motor, a gearbox, a coupling gear set and a clutch set, which are responsible for providing vehicle drive and work drive functions.

The hydraulic drive coupling system is composed of hydraulic oil tank assembly, accumulator, relief valve group and solenoid valve, and is responsible for providing the functions of hydraulic reversing and hydraulic coupling.

As shown in FIG. 1 , a range-extended vehicle electro-hydraulic hybrid drive system and a control method thereof according to an embodiment of the present invention are described.

Using the speed constraint relationship and torque constraint relationship of the planetary gear train, through the control of the extended-range power control unit, three power generation modes can be formed:

1. Power generation mode 1: single motor power generation mode - the engine brake is unlocked, the engine clutch is engaged, the first brake is locked, and the second brake is unlocked; - the motion and torque between the engine and the ISG2 motor form a coupling relationship, and the ISG2 motor can execute Starting and generating functions;

Control idea: adjust the engine speed to the economic speed range, and adjust the speed ratio of the planetary mechanism, the ISG2 motor works in an efficient and economical area of load and speed, and this speed range needs to match the working speed range of the connected hydraulic oil pump;

Scenarios of use: high-efficiency power generation with medium/small power, and also drive the hydraulic oil pump to work.

Power generation: P1＝－P3＝T1·n1＝T1·(1+k)·n3＝－T3/(1+k)·n1＝－T3·n3,

Speed relation: n1=(1+k)·n3, torque relation: T1//T3=1/-(1+K).

Note: T1 here is the coupling torque between the generator and the hydraulic oil pump. When the hydraulic oil pump is not connected or has no load, T1 is equal to the torque of the generator itself.

Power generation control method: one of the engine and the second generator selects the torque control mode, and the other selects the rotational speed control mode.

2. Power generation mode 2: single motor power generation mode - the engine brake is unlocked, the engine clutch is engaged, the first brake is unlocked, and the second brake is locked; - the motion and torque between the engine and the ISG1 motor form a coupling relationship, and the ISG1 motor can execute Starting and generating functions;

Control idea: adjust the engine speed to the economic speed range, and adjust the speed ratio of the planetary mechanism. The ISG1 motor works in an efficient and economical area of load and speed. This speed range needs to match the working speed range of the connected hydraulic oil pump; use scenario: medium / The low-power and high-efficiency power generation also drives the hydraulic oil pump to work.

Power generation: P2＝－P3＝T2·n2＝T2·(1+k)/k·n3＝－T3·k/(1+k)·n2＝－T3·n3,

Speed relationship: n2=(1+k)/k·n3,

Torque relation: T2/T3=K/－(1+K). Note: T2 here is the coupling torque between the generator and the hydraulic oil pump. When the hydraulic oil pump is not connected or has no load, T2 is equal to the torque of the generator itself.

Power generation control method: one of the engine and the first generator selects the torque control mode, and the other selects the rotational speed control mode.

3. Power generation mode 3: Dual motor power generation mode - engine brake is unlocked, engine clutch is engaged, the first brake is unlocked, and the second brake is unlocked; - a power coupling relationship is formed between the engine and the ISG1 and ISG2 motors, which can perform starting and power generation Function;

Control method: adjust the engine speed to the economic speed range, distribute the power generated by the speed/torque coupling relationship between the ISG1 and ISG2 motors and the principle of power splitting, so that the two sets of motors work in the efficient and economical area of load and speed at the same time , the speed range of the ISG1 and ISG2 motors needs to match the working speed range of the connected hydraulic oil pump;

Applicable scenarios: medium/high power and high-efficiency power generation, and also drive the hydraulic oil pump to work.

Generating power:

P1+P2＝－P3＝T1·n1+T2·n2＝T1·n1+T1·K·n2＝T2/K·n1+T2·n2＝－T3/(1+k)·n1－T3·k/ (1+k)·n2＝－T3·n3,

Speed relationship: n1+k·n2=(1+k)·n3,

Torque relationship: T1/T2/T3=1/K/－(1+K).

Note: T1 and T2 here are the coupling torque between the generator and the hydraulic oil pump. When the hydraulic oil pump is not connected or has no load, T1 and T2 are equal to the torque of the generator itself.

Power generation control method: Among the three components of the engine and the generator, only one component can select the torque control mode, and the other two select the speed control mode.

Using the speed constraint relationship and torque constraint relationship of the planetary gear train, through the control of the range extension control unit, four hydraulic oil pump driving modes can be formed:

1. Mode 1: Single-motor drive mode - the engine brake is locked, the engine clutch is engaged, the first brake is unlocked, and the second brake is unlocked; - the motion and torque between the ISG1 and ISG2 motors form a coupling relationship, either of the two sets of motors. Provided power can drive two sets of hydraulic oil pumps to work at the same time, and the other set of motors can follow. This mode is suitable for situations where the total power of the hydraulic oil pump does not exceed the driving capability of a single motor.

2. Mode 2: Dual-motor common driving mode - the engine brake is locked, the engine clutch is engaged, the first brake is unlocked, and the second brake is unlocked; - the motion and torque between the ISG1 and ISG2 motors form a coupling relationship, and the two sets of motors are simultaneously Provide power to drive the hydraulic oil pump to work. Here, it is necessary to coordinate the driving torques of the two groups of motors for forward coupling and jointly output power. This mode is suitable for situations where the total power of the hydraulic oil pump exceeds the driving capability of a single motor.

3. Mode 3: Dual-motor independent drive mode - the engine clutch is disengaged, the first brake is unlocked, and the second brake is unlocked; - there is no torque and motion coupling relationship between the ISG1 and ISG2 motors, and the motion can be freely controlled respectively. The two sets of motors respectively drive the hydraulic oil pumps connected to them to work. This mode is suitable for the situation where the working range of different hydraulic oil pumps has a large deviation, and the motion constraint relationship between the ring gear and the planet carrier cannot be used after the sun gear is fixed.

4. Mode 4: Dual-motor coordinated drive mode—the engine brake is unlocked, the engine clutch is engaged, the first brake is unlocked, and the second brake is unlocked;—the power to drive the hydraulic oil pump comes from the planet carrier input of the planetary gear mechanism, among which the engine, The motion and torque between the ISG1 and ISG2 motors form a coupling relationship. The direct or indirect speed coordination control of the ISG1 and ISG2 motors is used to drive the hydraulic oil pump to work. The torque fluctuations of the ISG1 and ISG2 motors need to be dynamically adjusted according to the change of the connected equipment load. Balance compensation can form the state of driving the hydraulic oil pump while generating electricity. This mode is suitable when the engine is involved in work.

By controlling the control position of the solenoid valve, 3 hydraulic coupling modes can be realized:

1. Mode 1: Independent hydraulic mode - the solenoid valve is controlled in the neutral position, the first hydraulic oil pump provides hydraulic power for the working hydraulic motor, the second hydraulic oil pump provides hydraulic power for the driving hydraulic motor, and the two hydraulic power lines have no hydraulic power. Flow coupling, independent of each other without interfering with each other.

2. Mode 2: Combined hydraulic mode - the solenoid valve is controlled at the side position, the first hydraulic oil pump and the second hydraulic oil pump can provide hydraulic power for one of the driving hydraulic motor or the working hydraulic motor together, and the liquid flows in the solenoid valve. Forming a coupling, it can provide high-power hydraulic power for the hydraulic motor.

3. Mode 3: Exchange hydraulic mode - control the solenoid valve in the side position, only open the non-corresponding hydraulic oil pump, which can form a unilateral exclusive hydraulic drive. That is, when the solenoid valve is in the left position, only the first hydraulic oil pump is turned on, which provides hydraulic power for driving the hydraulic motor; when the solenoid valve is in the right position, only the second hydraulic oil pump is turned on, which provides hydraulic power for the working hydraulic motor.

According to the state of the two sets of clutches and the use of the vehicle, 8 modes of hydraulic power participating in the driving of the vehicle can be formed:

1. Mode 1: Front-end motor linkage mode—the third clutch is engaged, and the fourth clutch is disengaged;—the driving hydraulic motor and the driving motor form torque coupling, which together form the vehicle driving torque through the gearbox to drive the vehicle. Here, The driving hydraulic motor mainly plays the role of the low-speed backup power of the vehicle, and also plays the role of restraining and compensating the torque peak value of the driving motor.

2. Mode 2: rear-end output linkage mode—the third clutch is disengaged, and the fourth clutch is engaged;—the drive hydraulic motor forms torque coupling with the gearbox output shaft, that is, the torque coupling with the motor after passing through the gearbox, To drive the vehicle together, the driving hydraulic motor mainly plays the role of the medium/high-speed backup power of the vehicle.

3. Mode 3: Start assist mode - By controlling the speed of the hydraulic oil pump, a very stable and smooth hydraulic driving force is formed at the driving hydraulic motor, and the vehicle starts smoothly and comfortably. At the same time, it can start in conjunction with the drive motor to form a strong static starting torque to complete the starting assist role in extreme road conditions, and the driving hydraulic motor is not afraid of stalling.

4. Mode 4: Shift assist mode - single-motor AMT transmission will cause power interruption when shifting, and the drive shaft will appear in a process state of complete unloading. Actions such as tether elasticity, sudden change in power loading and unloading, and synchronisation will cause a larger shift shock to the transmission system. The hydraulic motor is used to drive the rear end coupling gear of the gearbox to work, and it participates in the torque interruption compensation during the shifting process, which can reduce the impact strength of the shifting and optimize the shifting feeling.

5. Mode 5: Anti-slope assist mode - divided into two situations: starting to prevent slipping and shifting to prevent slipping. When starting statically, the large static starting torque of the driving hydraulic motor and the characteristics of not being afraid of stalling can better realize the function of starting slope prevention together with the motor. When a heavy-duty vehicle is climbing a slope at a low speed, the power interruption is very dangerous. At this time, the power of the driving hydraulic motor can directly act on the coupling gear at the rear end of the gearbox, making up for the power output to a large extent and forming the function of shifting and anti-slope.

6. Mode 6: Parking mode - the third clutch and the fourth clutch are combined at the same time, which can form the transmission system movement interference through the gearbox, so as to achieve the effect of the transmission system parking.

7. Mode 7: limp mode - when the vehicle drive system fails, the power to drive the hydraulic motor can be connected to the transmission system through the clutch to realize low-speed drive creep.

8. Mode 8: Isolation mode - the third clutch and the fourth clutch are disengaged at the same time, and the driving hydraulic motor is isolated from the transmission system, and no longer participates in the transmission of speed and torque.

The range-extended vehicle electro-hydraulic hybrid drive system of the present invention is adopted to expand the scope and distribution of the high-efficiency working area of the multi-cylinder engine power generation system, so as to improve the coverage of the dynamic and economical working conditions of the power generation system, especially to solve the problem that the high-power engine power generation system is continuously small Economic issues in the state of power generation demand. The invention improves the starting or passing ability of the vehicle under severe working conditions, and utilizes an integrated hydraulic unit for hydraulic power coupling to compensate for the peak demand of driving force. Through the power coupling of the hydraulic drive unit, the invention realizes a stable start at a low speed, and at the same time, it can compensate for the interruption of shifting power and optimize the impact feeling of shifting. The present invention reduces the risk of driving failure by increasing the hydraulic drive unit, increasing the hydraulic starting and anti-slope functions and the gear shifting and anti-slope functions. The invention integrates the hydraulic drive unit, one machine has multiple functions, that is, it can also drive the bodywork equipment to work while generating electricity, which improves the system integration degree and improves the energy conversion efficiency because the design of the hydraulic motor driven by a separate motor is reduced. The invention improves the energy efficiency coordination capability of the range extension system, that is, through the coupling principle of the double generator and the planetary mechanism, power generation and operation can be efficiently coupled, and the energy utilization efficiency can be improved.

In this specification, the invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and changes can still be made without departing from the spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

Claims (9)

1. An electro-hydraulic hybrid driving system of a range-extended vehicle is characterized by comprising an engine, an engine brake, an engine clutch, a first generator, a first brake, a planetary gear mechanism, a second generator, a second brake, a second clutch, a second hydraulic oil pump, a driving motor, a coupling gear of a transmission input shaft, a transmission, a coupling gear of a transmission output shaft, a hydraulic driving gear of a transmission output shaft, a fourth clutch, a third clutch, a hydraulic driving gear of a transmission input shaft, a driving hydraulic motor, a working hydraulic motor, an electromagnetic valve, a second overflow valve, a second one-way valve, a first overflow valve, a first one-way valve, a first hydraulic oil pump, a first clutch, a range-extended driving control unit, a hydraulic oil tank assembly and an energy accumulator, wherein the first generator is connected with a gear ring of the planetary gear mechanism, the second generator is connected with the sun gear, the planet carrier is connected with the engine through an engine clutch, the first hydraulic oil pump and the first generator form a transmission connection relationship through the first clutch, and the second hydraulic oil pump is connected with the second generator through the second clutch; the system is controlled according to the states of the third clutch and the fourth clutch, the power of the hydraulic motor is respectively coupled from the input shaft of the gearbox or the output shaft of the gearbox through two groups of coupling gears, and the third clutch and the fourth clutch cannot be combined simultaneously in the driving process; the output end of the first hydraulic oil pump and the output end of the second hydraulic oil pump are connected with the electromagnetic valve, and the output end of the electromagnetic valve is respectively connected with the driving hydraulic motor and the operation hydraulic motor.

2. The extended range vehicle electro-hydraulic hybrid driving system of claim 1, wherein when a moving component in the planetary gear train is simultaneously connected with the first generator, the second generator, the first hydraulic oil pump and the second hydraulic oil pump, the torque acting on the gear train component is formed by forward coupling of the generator torque and the hydraulic oil pump torque, the generator and the hydraulic oil pump synchronously participate in the torque/rotation speed coupling and power splitting mechanism of the planetary gear train, and when the load of the hydraulic oil pump changes, the generator performs load change balance compensation.

3. The range-extended vehicle electro-hydraulic hybrid driving system according to claim 1, wherein oil inlets of a first hydraulic oil pump and a second hydraulic oil pump in the system are connected to a hydraulic oil tank, overflow valves are respectively arranged at outputs of the first hydraulic oil pump and the second hydraulic oil pump, the inputs of the overflow valves are connected in parallel with an input of a one-way valve, an energy accumulator at an output of the second one-way valve is connected in parallel with an input of a No. 4 electromagnetic valve, an output of the first one-way valve is directly connected with an input of a No. 3 electromagnetic valve, and the three-position four-way electromagnetic valve realizes the functions of simultaneously driving a hydraulic driving motor and a working driving motor, interrupting the hydraulic power of a motor of one loop and jointly driving the same hydraulic motor by the two pumps through 2 converging functions and 1 diverging function; the accumulator can buffer pressure pulsation impact in the hydraulic circuit and can form gradual change controllable and stable hydraulic power output together with the hydraulic oil pump.

4. The electro-hydraulic hybrid driving system for the extended range vehicle of claim 1, wherein the extended range driving control unit realizes the control function of a generator, a clutch, a brake and an electromagnetic valve, and simultaneously cooperates with an engine, a driving motor system, a gearbox system or other systems of the vehicle to realize the logic control function of a power system.

5. The electric-hydraulic hybrid driving system for the extended range vehicle according to claim 1, characterized in that the system has three power generation modes, and the extension of the high-efficiency power working area of the power generation system is realized by the strategy control of the extended range drive control unit according to the working principle of a planetary gear train mechanism, namely 2 single-motor power generation modes and 1 double-motor power generation mode are formed.

6. The range-extended vehicle electro-hydraulic hybrid driving system according to claim 1, characterized in that the system has three starting modes, wherein 2 single-motor starting modes and 1 double-motor starting mode are formed by controlling an engine brake, a first brake, a second brake and an engine clutch and matching with a vehicle energy storage system through strategy control of a range-extended power control unit.

7. The electric-hydraulic hybrid driving system for the extended range vehicle according to claim 1, characterized in that the system has four hydraulic oil pump driving modes, namely a single-motor driving mode, a double-motor common driving mode, a double-motor independent driving mode and a double-motor coordination driving mode, by controlling the rotation speeds of a brake, a clutch, a generator and an engine.

8. The electric-hydraulic hybrid driving system for the range-extended vehicle according to claim 1, wherein the system has three hydraulic coupling modes, that is, an independent hydraulic mode, a combined hydraulic mode and an alternate hydraulic mode, by controlling the first hydraulic oil pump and the second hydraulic oil pump and the solenoid valve.

9. The electro-hydraulic hybrid driving system for the range-extended vehicle of claim 1, wherein the system has eight modes of hydraulic power participating in driving, and 8 modes of hydraulic power participating in driving, namely a front-end motor linkage mode, a rear-end output linkage mode, a starting auxiliary mode, a gear shifting auxiliary mode, an anti-slope-slipping auxiliary mode, a parking mode, a limp mode and an isolation mode, are formed through state control and working conditions of a third clutch and a fourth clutch.

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