CN104816621A - Hydraulic hybrid power vehicle and hydraulic hybrid power system thereof - Google Patents

Abstract

The invention discloses a hydraulic hybrid vehicle and its hydraulic hybrid system. In the hydraulic hybrid system, the output shaft of the engine is directly connected to the input shaft of the first transmission gear set, and the first output shaft of the first transmission gear set passes through a clutch. Connect/disconnect the first input shaft of the second transmission gear set; the second output shaft of the first transmission gear set connects the drive shaft of the hydraulic pump, and the hydraulic oil outlet of the hydraulic pump connects/disconnects the hydraulic pump/motor through the direction control valve , the output shaft of the hydraulic pump/motor is connected to the second input shaft of the second transmission gear set; the output shaft of the second transmission gear set is connected to the drive axle of the hydraulic hybrid vehicle; the main oil circuit at the outlet of the hydraulic pump can pass through the directional control valve It is connected/disconnected with the oil inlet and outlet of the hydraulic pump/motor; the working oil port of the high-pressure accumulator can be connected/disconnected with the main oil circuit through the switch valve, so that the hydraulic oil in the main oil circuit can flow into the high-pressure accumulator The hydraulic oil in the device or high-pressure accumulator flows into the main oil circuit; the power system has relatively high reliability, and the energy recovery rate is relatively high.

Description

Hydraulic hybrid vehicle and its hydraulic hybrid system

technical field

The invention relates to the technical field of vehicle hydraulic control, in particular to a hydraulic hybrid vehicle and a hydraulic hybrid system thereof.

Background technique

A hydraulic hybrid vehicle is a vehicle that is driven by hydraulic and mechanical configurations. It has been widely used in daily life, such as hydraulic hybrid drive loaders, bulldozers and other construction machinery vehicles.

Please refer to FIG. 1 , which is a schematic structural diagram of a hydraulic hybrid power system of a hydraulic hybrid power vehicle in the prior art.

The hydraulic hybrid power system in the prior art includes a hydraulic variable pump 1', a one-way valve 2', a central controller 3', a two-position two-way reversing valve 4', a high-pressure hydraulic accumulator 5', a brake 7', a planetary Gear train 8', transmission 9', engine 10', clutch 11', low-pressure hydraulic accumulator 12', hydraulic pump/motor 14', drive axle 15', transmission shaft 16'.

The engine 10' is sequentially connected with the clutch 11' and the transmission 9', the input shaft of the planetary gear train 8' is connected with the output shaft of the transmission 9', and the first output shaft 17' of the planetary gear train 8' is connected with one end of the transmission shaft 16' , the other end of the drive shaft 16' is connected to the input end of the transaxle 15', the second output shaft 13' of the planetary gear train 8' is connected to the hydraulic pump/motor 14', and the third output shaft 6 of the planetary gear train 8' ' is connected with the hydraulic variable pump 1', the oil inlet port of the hydraulic pump/motor 14' is connected with the oil inlet port of the two-position two-way reversing valve 4', and the oil outlet port of the one-way valve 2', and the two-position two-way reversing valve The oil outlet of the directional valve 4' is connected with the oil port of the high-pressure hydraulic accumulator 5', the oil inlet port of the check valve 2' is connected with the oil outlet port of the hydraulic variable pump 1', and the outlet port of the hydraulic pump/motor 14' The oil port, the oil inlet port of the hydraulic variable pump 1' is connected with the oil port of the low-pressure hydraulic accumulator 12', the control input port of the two-position two-way reversing valve 4' is connected with the first control output port of the central controller 3' end connection.

When the vehicle starts or runs at a low speed, the central controller controls the work of the hydraulic pump/motor and the working condition of the motor, and at the same time controls the opening of the two-position two-way reversing valve. The high-pressure hydraulic accumulator provides a high-pressure oil source for the hydraulic pump/motor. At this time, the engine is in a stopped state; when the pressure in the high-pressure hydraulic accumulator is close to the minimum working pressure, the engine 1' starts, and the hydraulic pump/motor does not work.

When the vehicle speed exceeds the critical speed, the combined hydraulic and mechanical drive is adopted, and the engine and hydraulic pump/motor jointly drive the vehicle. The central controller controls the clutch combination, and the mechanical energy of the engine drives the vehicle through the clutch, transmission shaft, and drive axle; the central controller controls the opening of the two-position two-way reversing valve, and the energy of the hydraulic accumulator drives the hydraulic pump/motor, star gear train , transmission shaft, and drive axle to drive the vehicle to achieve hybrid drive.

When the vehicle is in braking condition, the central controller sends a control signal to the hydraulic pump/motor, so that the hydraulic pump/motor works in the pump working condition, and at the same time opens the two-position two-way reversing valve to feed back energy to the high-pressure accumulator.

It can be seen from the above description that when there is no pressure in the high-pressure accumulator, the pure hydraulic starting function at low speed will not be realized, seriously affecting the normal operation of the vehicle. Moreover, the system can only recover the mechanical energy of the wheel's rotational inertia.

In addition, the braking energy recovered in the system can only be applied to the low-speed pure hydraulic starting function of the vehicle. When the recovered braking energy reaches the maximum capacity of the high-pressure accumulator, the excess energy cannot be applied to the working device of the construction machinery.

Therefore, how to improve the hydraulic hybrid power system in the prior art, which has relatively high reliability and relatively high energy recovery rate, is a technical problem to be solved urgently by those skilled in the art.

Contents of the invention

The object of the present invention is to provide a hydraulic hybrid vehicle and its hydraulic hybrid system, the power system has relatively high reliability, and the energy recovery rate is relatively high.

In order to solve the above technical problems, the present invention provides a hydraulic hybrid power system, including an engine, a hydraulic pump/motor, a hydraulic pump, and a high-pressure accumulator, and a directional control valve is arranged between the hydraulic pump and the hydraulic pump/motor , including transfer case and power coupling mechanism,

The output shaft of the engine is directly connected to the input shaft of the transfer case, and the first output shaft of the transfer case is connected/disconnected with the first input shaft of the power coupling mechanism through a clutch;

The second output shaft of the transfer case is connected to the drive shaft of the hydraulic pump, the hydraulic oil outlet of the hydraulic pump is connected/disconnected with the hydraulic pump/motor through the directional control valve, and the output of the hydraulic pump/motor a shaft connected to the second input shaft of the power coupling mechanism;

The output shaft of the power coupling mechanism is connected to the drive axle of the hydraulic hybrid vehicle;

The outlet main oil circuit of the hydraulic pump can be connected/disconnected with the oil inlet and the oil outlet of the hydraulic pump/motor through the directional control valve;

The working oil port of the high-pressure accumulator can connect/disconnect the main oil circuit through the switch valve, so that the hydraulic oil in the main oil circuit flows into the high-pressure accumulator or the hydraulic oil in the high-pressure accumulator flows into the main oil circuit .

Preferably, it also includes a multi-way valve group, the main oil circuit connects/disconnects the steering cylinder or/and working cylinder of the hydraulic hybrid vehicle through the multi-way valve group;

When the hybrid vehicle is in the braking state, the outlet of the hydraulic pump/motor can be connected to the steering cylinder or/and working cylinder of the hydraulic hybrid vehicle through the main oil circuit through the multi-way valve group. Working oil chamber to realize vehicle steering or work;

The steering oil cylinder is used for wheel steering; the working oil cylinder is used for driving the working device of the hydraulic hybrid vehicle.

Preferably, the outlet of the hydraulic pump can communicate with the steering oil cylinder or/and the working oil chamber of the working oil cylinder via the main oil circuit through the multi-way valve group, so as to realize vehicle steering or working.

Preferably, the working oil chamber of the steering oil cylinder or/and working oil cylinder is further connected/disconnected with the working oil port of the high-pressure accumulator through the multi-way valve group;

When the steering oil cylinder or/and the working oil chamber of the working oil cylinder returns oil, the steering oil cylinder or/and the working oil chamber of the working oil cylinder communicate with the working oil port of the high-pressure accumulator.

Preferably, the pipeline connecting the main oil circuit and the working oil port of the high-pressure accumulator includes a first pipeline and a second pipeline, and the switch valve includes a first switch valve and a second switch valve; A switch valve is set in the first pipeline, and the second switch is set in the second pipeline;

Hydraulic oil flows out of and into the interior of the high-pressure accumulator through the first line and the second line, respectively.

Preferably, a first one-way valve and a second one-way valve are respectively arranged on the first pipeline and the second pipeline.

Preferably, a gearbox is also included, and the gearbox is arranged between the clutch and the power coupling mechanism.

Preferably, the hydraulic pump is a variable hydraulic pump, and the hydraulic pump/motor is a variable hydraulic pump/motor.

Preferably, the directional control valve is a three-position four-way reversing valve. When the three-position four-way reversing valve is in the first working position, the high-pressure accumulator and the hydraulic pump can pass through the three-position four-way reversing valve. The one-position four-way reversing valve communicates with the oil inlet of the hydraulic pump/motor, and the oil outlet of the hydraulic pump/motor communicates with the oil return circuit through the three-position four-way reversing valve; when the three-position When the four-way reversing valve is in the second working position, the oil inlet port of the hydraulic pump/motor is connected to the oil return circuit, and the oil outlet is connected to the high pressure through the three-position four-way reversing valve. Accumulator; when the three-position four-way reversing valve is in the neutral position, the oil outlet and the oil inlet of the hydraulic pump/motor are connected.

In the hydraulic hybrid system of the present invention, the engine can transmit power to the drive axle through the transfer case, clutch, and power coupling mechanism to drive the wheels to move forward or backward; the engine can also pass through the transfer case, hydraulic pump, etc. . The power coupling mechanism converts the power into hydraulic energy first, and the hydraulic pump drives the hydraulic pump/motor to rotate through the main oil circuit, and the hydraulic pump/motor converts the hydraulic energy into mechanical energy and transmits it to the drive axle to drive the wheels to complete the forward movement of the vehicle Or retreat; Of course, the power of the engine can also be transmitted to the wheels through the above two ways simultaneously.

When braking the moving wheels, the clutch is disconnected, and the kinetic energy of the wheels is transmitted to the hydraulic pump/motor through the power coupling mechanism. At this time, the hydraulic pump/motor works as a pump and can brake the whole machine. Function; at the same time, the outlet of the hydraulic pump/motor is connected to the main oil circuit, which can enter the high-pressure accumulator through the main oil circuit, that is, the hydraulic pump/motor pumps the hydraulic oil from the low-pressure return oil circuit to the high-pressure accumulator, and the Energy is stored.

When the power system detects that the energy in the high-pressure accumulator cannot drive the hydraulic pump/motor at the initial stage of vehicle startup, the engine can drive the hydraulic pump to supply oil to the hydraulic pump/motor, increasing the reliability of the system.

Of course, check valves, reversing valves, and other components can be added to the hydraulic conduction oil circuit in the power system to increase the reliability of the system, and the specific setting methods will not be described in detail in this article.

In a specific implementation, the main oil circuit connects/disconnects the steering cylinder or/and working cylinder of the hydraulic hybrid vehicle through the multi-way valve group; when the hybrid vehicle is in a braking state, The main oil circuit can communicate with the steering oil cylinder or/and the working oil chamber of the working oil cylinder of the hydraulic hybrid vehicle through the multi-way valve group;

The steering oil cylinder is used for wheel steering; the working oil cylinder is used to drive the working device of the hydraulic hybrid vehicle. Taking a loader as an example, the working device of the loader is a bucket, and the working oil cylinder is a bucket connected to the bucket. Push the cylinder.

In this embodiment, the energy recovered when the vehicle brakes can be directly used to control the steering cylinder or the working cylinder to realize the steering of the vehicle or the action of the working device, without being recovered to the accumulator for storage and reuse, so that the energy recovered by braking The utilization efficiency is higher. Moreover, the energy recovered by braking can not only be stored in the high-pressure accumulator to drive the vehicle, but also can control the action or steering of the working device, so that the recovered energy can be used in a wider range.

In addition, the hydraulic pump in the above-mentioned power system can be used to supply oil to the working cylinder and the steering cylinder to meet the working requirements of the working cylinder and the steering cylinder, and the original independent steering pump and working cylinder in the prior art can be eliminated. Install the pump to reduce the cost of using the vehicle.

On the basis of the above-mentioned hydraulic hybrid power system, the present invention also provides a hydraulic hybrid power vehicle, including wheels and a hydraulic hybrid power system for controlling the wheels. Hybrid power system.

Since the hydraulic hybrid vehicle in the present invention has the above-mentioned hydraulic hybrid system, the hydraulic hybrid vehicle also has the above-mentioned technical effects of the hydraulic hybrid system.

Description of drawings

FIG. 1 is a schematic structural diagram of a hydraulic hybrid system of a hydraulic hybrid vehicle in the prior art;

Fig. 2 is a schematic structural diagram of a hydraulic hybrid power system in a specific embodiment of the present invention.

Wherein, the one-to-one correspondence between the reference numerals and component names in Figure 1 is as follows:

Hydraulic variable pump 1', one-way valve 2', central controller 3', two-position two-way reversing valve 4', high-pressure hydraulic accumulator 5', brake 7', planetary gear train 8', transmission 9', Engine 10', clutch 11', low pressure hydraulic accumulator 12', hydraulic pump/motor 14', transaxle 15', transmission shaft 16', first output shaft 17'.

Wherein, the one-to-one correspondence between the component names and the reference numerals in Fig. 2 is as follows:

Engine 1, multi-way valve group 2, transfer case 3, hydraulic pump 4, one-way valve 5, first switch valve 6, first one-way valve 7, second one-way valve 24, powertrain controller 8, High-pressure accumulator 9, overflow valve 10, hydraulic pump/motor 11, steering cylinder 12, clutch 13, gearbox 14, low-pressure fuel tank 15, power coupling mechanism 16, drive axle 17, three-position four-way reversing valve 18, Main shaft 20, main oil circuit 21, working oil cylinder 22, second on-off valve 23.

Detailed ways

The core of the present invention is to provide a hydraulic hybrid vehicle and its hydraulic hybrid system, the power system has relatively high reliability and relatively high energy recovery rate.

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Please refer to FIG. 2 , which is a schematic structural diagram of a hydraulic hybrid power system in a specific embodiment of the present invention.

The present invention provides a hydraulic hybrid power system, which includes an engine 1, a hydraulic pump/motor 11, a hydraulic pump 4, and a high-pressure accumulator 9. The hydraulic pump/motor 11 is a pump that can be used as a The power of mechanical rotation is converted into hydraulic pressure, and it can also be used as a motor to convert hydraulic energy into power of mechanical rotation.

A directional control valve is also arranged between the hydraulic pump 4 and the hydraulic pump/motor 11 in the present invention, and the directional control valve can control the flow of hydraulic oil between the hydraulic pump 4 and the hydraulic pressure/motor according to the needs of use. The present invention also includes transfer case 3 and power coupling mechanism 16, the output shaft of engine 1 directly connects the input shaft of transfer case 3, and the first output shaft of transfer case 3 connects/disconnects the power coupling mechanism 16 through clutch 13 The first input shaft; the second output shaft of the transfer case 3 is connected to the drive shaft of the hydraulic pump 4, the hydraulic oil outlet of the hydraulic pump 4 is connected/disconnected with the hydraulic pump/motor 11 through the direction control valve, and the output of the hydraulic pump/motor 11 The shaft is connected to the second input shaft of the power coupling mechanism 16; the output shaft of the power coupling mechanism 16 is connected to the drive axle 17 of the hydraulic hybrid vehicle, and the drive axle 17 drives the main shaft 20 to move.

The outlet main oil circuit 21 of the hydraulic pump 4 among the present invention can be connected/disconnected with the oil inlet and the oil outlet of the hydraulic pump/motor 11 through the directional control valve; Connect/disconnect the main oil circuit 21.

A specific directional control valve is shown in Fig. 2, the directional control valve is a three-position four-way reversing valve 18, when the three-position four-way reversing valve 18 is in the first working position, the main oil circuit 21 can be The oil inlet port of the hydraulic pump/motor 11 is connected through the three-position four-way reversing valve 18, and the oil outlet of the hydraulic pump/motor 11 is connected with the oil return circuit through the three-position four-way reversing valve 18; when the three-position four-way When the reversing valve 18 is in the second working position, the oil inlet of the hydraulic pump/motor 11 is connected to the oil return circuit, and the oil outlet is connected to the main oil circuit 21 through the three-position four-way reversing valve 18; when the three-position four-way When the reversing valve 18 is in the neutral position, the oil outlet of the hydraulic pump/motor 11 communicates with the oil inlet.

In the hydraulic hybrid system of the present invention, the engine 1 can transmit power to the drive axle 17 through the transfer case 3, the clutch 13, and the power coupling mechanism 16 to drive the wheels to move forward or backward of the whole vehicle; The transfer case 3 and the hydraulic pump 4 power coupling mechanism 16 first convert the power into hydraulic energy, the hydraulic pump 4 stores energy in the high-pressure accumulator through the main oil circuit, and the high-pressure accumulator supplies the hydraulic pump/motor through the main oil circuit Action, the hydraulic energy is converted into mechanical energy and transmitted to the drive axle 17 to drive the wheels to move forward or backward; of course, the power of the engine 1 can also be transmitted to the wheels through the above two ways at the same time.

When the wheels in motion are braked, the clutch 13 is disconnected, and the kinetic energy of the wheels is transmitted to the hydraulic pump/motor 11 through the power coupling mechanism 16. At this time, the hydraulic pump/motor 11 works as a pump, which can control the entire machine. It acts as a brake; at the same time, the hydraulic pump/motor 11 pumps the hydraulic oil from the low-pressure oil return circuit to the high-pressure accumulator 9 to store energy.

On the other hand, under the action of the rotational inertia, the engine 1 can still drive the hydraulic pump 4 to rotate, so that the hydraulic pump 4 can pump the hydraulic oil into the high-pressure accumulator 9, and store this part of energy, which further improves energy recovery. Rate.

When the power system detects that the energy in the high-pressure accumulator 9 cannot drive the hydraulic pump/motor 11 at the initial stage of vehicle startup, the engine 1 can drive the hydraulic pump 4 to supply oil to the hydraulic pump/motor 11, increasing the reliability of the system. .

Of course, check valves, reversing valves, and other components can be added to the hydraulic conduction oil circuit in the power system to increase the reliability of the system, and the specific setting methods will not be described in detail in this article.

In a specific embodiment, the main oil circuit 21 connects/disconnects the steering cylinder 12 or/and the working oil cylinder 22 of the hydraulic hybrid vehicle through the multi-way valve group 2; when the hybrid vehicle is in a braking state, the main oil The road 21 can communicate with the steering cylinder 12 or/and the working oil chamber of the working cylinder 22 of the hydraulic hybrid vehicle through the multi-way valve group 2;

The steering cylinder 12 is used for wheel steering; the working cylinder 22 is used to drive the working device of the hydraulic hybrid vehicle. Taking a loader as an example, the working device of the loader is a bucket, and the working cylinder 22 is a pushing cylinder connected with the bucket.

In this embodiment, the energy recovered when the vehicle brakes can be directly used to control the steering cylinder 12 or the working cylinder 22, so as to realize the steering of the vehicle or the action of the working device, and it does not need to be recovered to the accumulator for storage and reuse. The recovered energy is used more efficiently. Moreover, the regenerative braking energy can not only be stored in the high-pressure accumulator 9 to drive the vehicle, but also can control the action or steering of the working device, so that the regenerative energy can be used in a wider range.

In addition, the hydraulic pump 4 in the above-mentioned power system can be used to supply oil to the working cylinder 22 and the steering cylinder 12 to meet the working requirements of the working cylinder 22 and the steering cylinder 12. Advanced steering pumps and working device pumps reduce vehicle use costs.

In a specific embodiment, the working oil chamber of the steering oil cylinder 12 or/and the working oil cylinder 22 can further connect/disconnect the working oil port of the high-pressure accumulator 9 through the multi-way valve group 2; when the steering oil cylinder 12 or/and When the working oil chamber of the working oil cylinder 22 returns oil, the steering oil cylinder 12 or/and the working oil chamber of the working oil cylinder 22 communicate with the working oil port of the high-pressure accumulator 9 .

In this way, the hydraulic oil in the working oil chamber of the steering oil cylinder 12 or/and the working oil cylinder 22 can flow into the high-pressure accumulator 9, that is to say, the high-pressure accumulator 9 in the power system can recover the energy of the vehicle service brake. On the basis of this, it can also recover the braking energy of steering and the working braking energy of the working device, and the braking energy recovery area is wider.

The pipeline connecting the main oil circuit 21 and the working oil port of the high-pressure accumulator 9 includes a first pipeline and a second pipeline, and the switch valve includes a first switch valve 6 and a second switch valve 23; the first switch valve 6 is provided In the first pipeline, the second switch is set in the second pipeline.

The hydraulic oil flows out and flows into the high-pressure accumulator 9 through the first pipeline and the second pipeline respectively; in this way, the hydraulic oil flows into and flows out of the high-pressure accumulator 9 through different channels, which can improve the reliability of the system operation.

In addition, on-off valves can be provided on both the first pipeline and the second pipeline, and the on-off valves are defined as the first one-way valve 7 and the second one-way valve 24, and the one-way valve 5 is set on the main oil circuit at the outlet of the hydraulic pump. , to ensure that the hydraulic oil is opened in one direction.

The hydraulic hybrid power system in each of the above embodiments may further include a gearbox 14 , and the gearbox 14 is arranged between the clutch 13 and the power coupling mechanism 16 .

The hydraulic pump 4 in the above embodiments can be a variable hydraulic pump 4 , and the hydraulic pump/motor 11 is a variable hydraulic pump/motor 11 .

The transfer case 3 and the power coupling mechanism 16 in the above-mentioned embodiments can be multi-stage transmission gear sets, which are set according to the specific use environment.

In addition, the main oil circuit 21 in the above-mentioned embodiments may also be provided with a relief valve 10, and the main oil circuit 21 communicates with the low-pressure oil tank 15 through the relief valve 10, thereby further ensuring the reliability of the system operation.

In the above-mentioned embodiments, the structure of the multi-way valve group 2 can be in various forms, as long as the above-mentioned technical effects can be achieved.

The control of the actions of the above components can be controlled by the powertrain controller 8 .

On the basis of the above-mentioned hydraulic hybrid power system, the present invention also provides a hydraulic hybrid power vehicle, including wheels and a hydraulic hybrid power system for controlling the wheels, and the hydraulic hybrid power system is any one of the above-mentioned hydraulic hybrid power systems.

For other parts of the hydraulic hybrid vehicle, please refer to the prior art, and details will not be repeated here.

Since the hydraulic hybrid vehicle in the present invention has the above-mentioned hydraulic hybrid system, the hydraulic hybrid vehicle also has the above-mentioned technical effects of the hydraulic hybrid system.

The hydraulic hybrid vehicle and its hydraulic hybrid system provided by the present invention have been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention, and the descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (9)

1. a hydraulic hybrid power system, comprise driving engine (1), hydraulic pump/motor (11), Hydraulic Pump (4), high pressure accumulator (9), it is characterized in that, directional control valve is provided with between described Hydraulic Pump and described hydraulic pump/motor, also comprise auxiliary gear box (3) and power coupling mechanism (16)

The output shaft of described driving engine (1) directly connects the input shaft of described auxiliary gear box (3), and the first output shaft of described auxiliary gear box (3) is connected by power-transfer clutch (13)/disconnected the first input shaft of described power coupling mechanism (16);

The axle drive shaft of the second output shaft connecting fluid press pump of described auxiliary gear box (3), the hydraulic oil outlet of described Hydraulic Pump is communicated with/disconnects described hydraulic pump/motor by described directional control valve, and the output shaft of described hydraulic pump/motor connects the second input shaft of described power coupling mechanism (16);

The output shaft of described power coupling mechanism (16) connects the drive axle (17) of hydraulic hybrid power vehicles;

Described hydraulic pressure delivery side of pump working connection (21) all by directional control valve can be communicated with oil outlet with the oil inlet of described hydraulic pump/motor/disconnect;

The actuator port of described high pressure accumulator (9) can be communicated with/disconnect described working connection (21) by switch valve,, so that the hydraulic oil that the hydraulic oil in working connection (21) flows in described high pressure accumulator (9) or described high pressure accumulator (9) flows into described working connection (21).

2. hydraulic hybrid power system as claimed in claim 1, it is characterized in that, also comprise multiway valve group (2), described working connection (21) is communicated with/disconnects the steering cylinder (12) of described hydraulic hybrid power vehicles or/and operating cylinder (22) by described multiway valve group (2);

When described motor vehicle driven by mixed power is in braking mode, the outlet of described hydraulic pump/motor is communicated with described steering cylinder (12) or/and the working oil chamber of described operating cylinder (22), to realize Vehicular turn or work operations through described working connection (21) by described multiway valve group (2);

Described steering cylinder (12) is for wheel steering; Described operating cylinder (22) is for driving the equipment action of described hydraulic hybrid power vehicles.

3. hydraulic hybrid power system as claimed in claim 2, it is characterized in that, described hydraulic pressure delivery side of pump is communicated with described steering cylinder (12) or/and the working oil chamber of described operating cylinder (22), to realize Vehicular turn or work operations through described working connection by described multiway valve group (2).

4. hydraulic hybrid power system as claimed in claim 2, it is characterized in that, described steering cylinder (12) is or/and the working oil chamber of described operating cylinder (22) is communicated with further by described multiway valve group (2)/disconnects the actuator port of described high pressure accumulator (9);

When described steering cylinder (12) or/and the working oil chamber oil return of described operating cylinder (22) time, described steering cylinder (12) is or/and the working oil chamber of operating cylinder (22) is communicated with the actuator port of described high pressure accumulator (9).

5. the hydraulic hybrid power system as described in any one of Claims 1-4, it is characterized in that, be communicated with described working connection (21) and comprise the first pipeline being provided with on-off valve and the second pipeline being provided with on-off valve with the pipeline of the actuator port of described high pressure accumulator (9), switch valve comprises the first switch valve (6) and second switch valve (23); Described first switch valve (6) is located at described first pipeline, and described second switch valve (23) is located at described second pipeline;

Hydraulic oil flows out respectively by described first pipeline and described second pipeline and flows into the inside of described high pressure accumulator (9).

6. hydraulic hybrid power system as claimed in claim 1, it is characterized in that, also comprise change speed gear box (14), described change speed gear box (14) is located between described power-transfer clutch (13) and described power coupling mechanism (16).

7. hydraulic hybrid power system as claimed in claim 1, it is characterized in that, described Hydraulic Pump is volume adjustable hydraulic pump, and described hydraulic pump/motor is variable delivery hydraulic pump/motor.

8. the hydraulic hybrid power system as described in any one of claim 1 to 7, it is characterized in that, described directional control valve is three position four-way directional control valve (18), when described three position four-way directional control valve (18) is positioned at the first control position, described high pressure accumulator (9), described Hydraulic Pump are communicated with the oil inlet of described hydraulic pump/motor by described three position four-way directional control valve (18), and the oil outlet of described hydraulic pump/motor is communicated with oil return circuit by described three position four-way directional control valve (18); When described three position four-way directional control valve (18) is positioned at the second control position, the oil inlet of described hydraulic pump/motor is communicated with described oil return circuit, and described oil outlet is communicated with described high pressure accumulator (9) by described three position four-way directional control valve (18); When described three position four-way directional control valve (18) is in meta, the oil outlet of described hydraulic pump/motor is communicated with oil inlet.

9. a hydraulic hybrid power vehicles, comprises wheel and controls the hydraulic hybrid power system of described wheel, it is characterized in that, described hydraulic hybrid power system is the hydraulic hybrid power system described in any one of claim 1 to 8.