CN104859424A - Hydraulic auxiliary drive system by adopting wheel hub motors - Google Patents

Abstract

In order to solve the problem that traditional rear-drive vehicles cannot meet the power requirements on low adhesion coefficient roads and large slope roads, and the existing wheel hub motor hydraulic drive system cannot meet the large flow requirements of wheel hub motors, the invention proposes a hydraulic wheel hub motor auxiliary drive System, including hydraulic pump assembly, control valve group, controller, power take-off device, power take-off device output shaft, left front wheel, left wheel hub motor, right wheel hub motor, right front wheel, fuel tank, each reversing in the control valve group The valves are connected by pipelines, and each reversing valve in the control valve group is connected with the controller circuit. The power take-off device of the present invention drives the hydraulic pump, and the controller switches the working position of the control valve group to form multiple working modes. The electromagnetic reversing valve The control oil of the hydraulic reversing valve is controlled to control the working state of the hub motor. The control valve group of the present invention can ensure the reliable operation of the system to meet the large flow requirement of the hub motor.

Description

Hydraulic hub motor auxiliary drive system

technical field

The invention relates to a hydraulic auxiliary driving system, more precisely, the invention relates to a hydraulic system which adopts a hydraulic wheel hub motor for front wheel auxiliary driving.

Background technique

Heavy-duty trucks and engineering vehicles often operate on sandy, muddy, ice-snow and other low-adhesion roads, which require high power performance. In order to improve the dynamic performance of vehicles, traditional heavy vehicles often adopt all-wheel drive, but the system structure is complex and the mass is large. At present, there are proposals for all-wheel drive based on the power system structure of hybrid electric vehicles. For example, the Chinese patent publication number is CN101096180A, and the announcement date is 2008-01-02, which discloses a four-wheel drive hybrid power system, which uses a power distribution system, a front drive axle, a rear drive axle, a generator and an electric motor to realize four-wheel drive Technology. However, the shortcomings of current batteries such as low power density and short life make them unsuitable for heavy-duty truck implementation.

In the United States, Japan, France and other countries, a hydraulic auxiliary drive system was proposed as early as the 70th century, using a hydraulic pump to obtain power from the engine to drive a hydraulic motor to assist in driving the vehicle. The system has obvious advantages such as simple structure, high specific power, and low modification cost. It is suitable for commercial heavy-duty vehicles and has been successfully applied to many vehicles. For example, the French Poclain Co., Ltd. has successively proposed the wheel hub hydraulic auxiliary front axle drive system and the wheel hub hydraulic auxiliary rear axle drive system, and they have been applied on dump trucks and tractors. Bosch has also successfully developed a hydraulic traction auxiliary system. Although the technologies adopted by the above-mentioned systems are different, the working principles are similar. The systems all include structures such as hydraulic pumps, hydraulic motors, controllers, and hydraulic control valve groups. The most critical component is the hydraulic control valve group. The system needs to realize different working modes under the switching of the valve group, such as free wheel mode, auxiliary drive mode and bypass mode. At present, the research on hydraulic auxiliary drive system has been gradually carried out in China. For example, the Chinese patent publication number is CN102358163A, and the publication date is 2012-02-22, which discloses a hub motor hydraulic drive system, that is, a technology for converting a rear-wheel drive vehicle into a four-wheel drive configuration through a hydraulic auxiliary drive system. However, the patent does not introduce the structure of the valve group in detail. The Chinese patent publication number is CN103790876A, and the publication date is 2114-05-14, which discloses a closed hydraulic transmission system, which uses a group of hydraulic valves to realize different working modes of the system. In this patent, the working mode of the hub motor is controlled by a solenoid valve. However, the flow rate of the solenoid valve is generally small, which cannot meet the actual flow requirements.

Contents of the invention

The invention proposes a hydraulic wheel hub motor to solve the problem that the traditional rear-drive vehicle cannot meet the power requirements on the low adhesion coefficient road surface and the steep slope road surface, and the existing wheel hub motor hydraulic drive system cannot meet the large flow requirement of the wheel hub motor Auxiliary drive system, the present invention adopts following technical solution to realize:

Hydraulic hub motor auxiliary drive system, including hydraulic pump assembly, control valve group, controller, power take-off device, output shaft of power take-off device, left front wheel, left hub motor, right hub motor, right front wheel, fuel tank, power take-off device The output shaft and the input shaft of the hydraulic pump assembly in the hydraulic pump assembly are connected by spline pairs or universal joints. The external ports T1, T2, and T3 of the control valve group are connected to the oil tank through pipelines. Ports L1, L2, and L3 are all connected to the oil tank through pipelines, the external port M1 of the hydraulic pump assembly is connected to the external port G of the control valve group through pipelines, and the external port M2 of the hydraulic pump assembly is connected to the external port A of the control valve group. The external port M3 of the hydraulic pump assembly is connected to the external port B of the control valve group, and the external port D1 of the control valve group is connected to the casing oil discharge port of the left wheel hub motor and the casing oil discharge port of the right wheel hub motor. The external port D2 of the control valve group is connected to one oil port of the left hub motor, the external port D3 of the control valve group is connected to the other oil port of the left hub motor, and the external port D4 of the control valve group is connected to One oil port of the right hub motor is connected to the pipeline, and the external port D5 of the control valve group is connected to the other oil port of the right hub motor. The rotor shaft of the left hub motor and the drive shaft of the left front wheel are connected by a spline pair connection or both are the same shaft, the rotor shaft of the right hub motor and the transmission shaft of the right front wheel are connected by a spline pair or both are the same shaft, the controller and the hydraulic pump assembly are connected by a signal line, the controller It is connected with the circuit of the control valve group, and the controller is connected with the circuit of the hydraulic pump assembly, and it is characterized in that:

The control valve group includes: No. 4 overflow valve, No. 3 3-position 3-way directional valve, No. 1 2-position 4-way directional valve, No. 1 2-position 3-way directional valve, No. 2 2-position 3-way directional valve , No. 2, 2-position, 4-way reversing valve, No. 1, 2-position, 4-way hydraulic pilot reversing valve, No. 2, 2-position, 4-way hydraulic pilot reversing valve and No. 5 relief valve, among which, No. 3, 3-position, 3-way reversing valve The directional valve, No. 1 2-position 4-way directional valve, No. 1 2-position 3-way directional valve and No. 2 2-position 4-way directional valve are electromagnetic directional valves, and No. 4 relief valve and No. 5 relief valve It is a direct-acting relief valve, No. 2 2-position 3-way directional control valve, No. 1 2-position 4-way hydraulic pilot directional control valve and No. 2 2-position 4-way hydraulic pilot directional control valve are all hydraulic pilot directional control valves;

The T port of the three-position three-way reversing valve No. The P port of the three-way reversing valve is connected to the external port A of the control valve group, the P port of the No. External port B, T port of the No. 2 2-position 3-way reversing valve, P port of the 1st 2-position 4-way hydraulic pilot reversing valve, and T port of the No. 2 2-position 4-way hydraulic pilot reversing valve. The B port of the No. 2 2-position 3-way directional valve is connected to the T port of the 1st 2-position 4-way hydraulic pilot directional valve and the P port of the 2nd 2-position 4-way hydraulic pilot directional valve. The P port of the four-way directional valve is connected to the external port G of the control valve group, the P port of the No. 1 two-position three-way directional valve, and the P port of the No. 2 two-position four-way directional valve. The T port of the four-way reversing valve is connected with the A port of the No. 1 two-position three-way reversing valve, the T port of the No. two two-position four-way reversing valve, and the external port T2 of the control valve group. Port A of the four-way reversing valve is connected to the control port X of the No. 2 two-position four-way hydraulic pilot reversing valve, the oil inlet port of the No. 5 relief valve, and the external port D1 of the control valve group. The B port of the four-way reversing valve is connected to the Y pipeline of the control port of the No. 2 two-position four-way hydraulic pilot reversing valve, and the T port of the No. The control port of the No. 2 2-position 4-way reversing valve is connected with the pipeline. The A port of the No. 2 2-position 4-way directional valve is connected with the control port X of the No. The port is connected to the control port Y pipeline of the No. 1 two-position four-way hydraulic pilot reversing valve, the B port of the No. 1 two-position four-way hydraulic pilot reversing valve is connected to the external port D5 of the control valve group, The A port of the four-position hydraulic pilot directional valve is connected to the external port D4 of the control valve group, and the A port of the No. 2 two-position four-way hydraulic pilot directional valve is connected to the external port D2 of the control valve group. The port B of the No. 2-position four-way hydraulic pilot reversing valve is connected to the external port D3 of the control valve group, and the oil outlet of the No. 5 relief valve is connected to the external port T3 of the control valve group.

Further technical solutions include:

The circuit connection between the controller and the control valve group refers to:

The input ends of the electromagnetic coils at both ends of the No. 3 three-position three-way reversing valve in the control valve group are respectively connected to the port LA05 of the controller and the port LA06 of the controller through wires;

The input end of the electromagnetic coil of the No. 1 two-position four-way reversing valve in the control valve group is connected to the port LA07 of the controller through a wire;

The input end of the electromagnetic coil of the No. 1 two-position three-way reversing valve in the control valve group is connected to the port LA24 of the controller through a wire;

The input end of the electromagnetic coil of the No. 2 two-position four-way reversing valve in the control valve group is connected to the port LA25 of the controller through a wire.

The circuit connection between the controller and the hydraulic pump assembly refers to:

The No. 1 three-position three-way reversing valve in the hydraulic pump assembly is an electromagnetic reversing valve, and the input ends of the electromagnetic coils in the electromagnets at both ends are respectively connected to the port LA00 of the controller and the port LA01 of the controller through wires;

The No. 2 three-position three-way reversing valve in the hydraulic pump assembly is an electromagnetic reversing valve, and the input ends of the electromagnetic coils in the electromagnets at both ends are respectively connected to the port LA02 of the controller and the port LA03 of the controller through wires;

A displacement sensor is installed at the end of the hydraulic cylinder in the hydraulic pump assembly away from the hydraulic pump, and the output signal of the displacement sensor is connected to the port EAD00 of the controller through the signal line;

The two-position two-way reversing valve in the hydraulic pump assembly is an electromagnetic reversing valve, and the input end of the electromagnetic coil in the electromagnet is connected to the port LA04 of the controller through a wire.

The hydraulic hub motor auxiliary drive system obtains power from the engine through the power take-off device to drive the hydraulic pump, and switches the working position of the control valve group through the controller to form a variety of working modes, such as free wheel mode, auxiliary drive mode and bypass mode. The electromagnetic reversing valve controls the control oil of the hydraulic reversing valve, thereby controlling the working state of the hub motor, which can meet the large flow requirements of the hub motor.

Compared with prior art, the beneficial effect of the present invention is:

1. The hydraulic hub motor auxiliary drive system proposed by the present invention can change the front wheels of the vehicle from non-drive wheels to drive wheels, which is conducive to improving the power of the vehicle.

2. The hydraulic pump assembly in the hydraulic hub motor auxiliary drive system proposed by the present invention integrates the main pump, the servo control mechanism for adjusting its displacement, the oil supply system and the overflow valve, and the hydraulic motor adopts a radial plunger motor. And it is integrated in the hub of the front wheel, the whole system has a small structure size, takes up little space, and is simple and convenient to arrange and install;

3. The control valve group in the hydraulic hub motor auxiliary drive system proposed by the present invention can meet the large flow requirements of the hub motor in actual engineering, and can realize the switching of the hub motor in different states, and has better adaptability to working conditions;

4. In the hydraulic wheel hub motor auxiliary drive system proposed by the present invention, when the wheel hub motor is in the free wheel state, the hydraulic control valve group can keep a certain pressure in the motor housing, so that the motor plunger is completely separated from the motor housing, ensuring No additional load is applied to the front wheels when the motor is not working;

5. In the hydraulic hub motor auxiliary drive system proposed by the present invention, when the vehicle is shifting gears, the hub motor is bypassed through the control valve group, and the driving state is quickly restored after the gear shift is completed, which reduces the time for the hydraulic motor to switch states in a short time. The pressure change of the main oil circuit of the motor reduces the pressure shock of the motor casing and improves the working life of the hydraulic motor;

6. In the hydraulic hub motor auxiliary drive system of the present invention, the hydraulic components in the control valve group are integrated to reduce the volume occupied by the hydraulic system.

Description of drawings

Below in conjunction with accompanying drawing, the present invention will be further described:

Fig. 1 is a structural principle diagram of a hydraulic hub motor auxiliary drive system according to the present invention;

Fig. 2 is a structural diagram of the control valve group of the hydraulic hub motor auxiliary drive system according to the present invention;

Fig. 3 is a schematic diagram of the working position of each reversing valve in the free wheel mode of the hydraulic hub motor auxiliary drive system according to the present invention;

Fig. 4 is a schematic diagram of the working position of each reversing valve in the auxiliary drive mode of the hydraulic hub motor auxiliary drive system according to the present invention;

Fig. 5 is a schematic diagram of the working positions of the reversing valves in the bypass mode of the hydraulic hub motor auxiliary drive system according to the present invention;

Fig. 6 is a diagram of the increase ratio of the hydraulic hub motor auxiliary drive system according to the present invention to the improvement of traction force and gradeability of the whole vehicle obtained through simulation verification.

In the figure: 1. Power take-off device, 2. Output shaft of power take-off device, 3. Input shaft of hydraulic pump assembly, 4. No. 1 three-position three-way reversing valve, 5. No. 2 three-position three-way reversing valve, 6 .Hydraulic cylinder, 7. Hydraulic pump, 8. Charging pump, 9. No. 1 relief valve, 10. 2-position 2-way reversing valve, 11. No. 1 one-way valve, 12. No. 2 relief valve, 13. No. 2 one-way valve, 14. No. 3 overflow valve, 15. No. 3 one-way valve, 16. No. 4 overflow valve, 17. No. 3 three-position three-way reversing valve, 18. No. 1 two-position four-way Reversing valve, 19. No.1 two-position three-way reversing valve, 20. No. two two-position three-way reversing valve, 21. No. two two-position four-way reversing valve, 22. No.1 two-position four-way hydraulic pilot Reversing valve, 23. No. 2, 2-position, 4-way hydraulic pilot reversing valve, 24. No. 5 relief valve, 25. Left front wheel, 26. Left hub motor, 27. Right hub motor, 28. Right front wheel, 29. Fuel tank, 30. Controller, S. Displacement sensor, Ⅰ. Hydraulic pump assembly, Ⅱ. Control valve group.

M1, M2, M3, L1, L2, L3 are external ports of hydraulic pump assembly Ⅰ, G, A, B, T1, T2, T3, D1, D2, D3, D4, D5 are external ports of control valve group II.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to accompanying drawing 1, the hydraulic hub motor auxiliary drive system proposed by the present invention includes a hydraulic pump assembly I, a control valve group II, a controller 30, a power take-off device 1, a power take-off device output shaft 2, a left front wheel 25, and a left hub motor 26, right hub motor 27, right front wheel 28, oil tank 29.

Referring to the accompanying drawing 1, the power take-off device 1 and the output shaft 2 of the power take-off device provide power for the hydraulic pump assembly I, and the output shaft 2 of the power take-off device and the input shaft 3 of the hydraulic pump assembly are mechanically connected, and the connection method can be an ordinary key Either a spline pair or a universal joint connection, the function of the power take-off device 1 and the output shaft 2 of the power take-off device is to transmit power to the hydraulic pump assembly I, so that the hydraulic pump assembly I outputs smooth oil.

Referring to attached drawing 1, the hydraulic pump assembly I includes: hydraulic pump assembly input shaft 3, No. 1 three-position three-way reversing valve 4, No. 2 three-position three-way reversing valve 5, hydraulic cylinder 6, hydraulic pump 7, oil charge pump 8. No. 1 relief valve 9, 2-position 2-way reversing valve 10, No. 1 check valve 11, No. 2 overflow valve 12, No. 2 check valve 13, No. 3 overflow valve 14, No. 3 one-way valve valve 15. Among them, the hydraulic cylinder 6 is a double-piston rod hydraulic cylinder; the hydraulic pump 7 is an axial plunger type two-way variable hydraulic pump; the charge pump 8 is a one-way quantitative gear pump; The position three-way reversing valve 5 is an electromagnetic reversing valve; No. 1 relief valve 9, No. 2 relief valve 12 and No. 3 relief valve 14 are all direct-acting relief valves; No. 1 one-way valve 11, The No. 2 check valve 13 and the No. 3 check valve 15 are direct acting check valves.

Referring to attached drawing 1, the input shaft 3 of the hydraulic pump assembly is the same shaft as the rotor shaft of the hydraulic pump 7 and the charge pump 8; the T port of the No. The T port of 5, the external port L1 of the hydraulic pump component I are connected with the pipeline, the P port of the No. 1 three-position three-way reversing valve 4 is connected with the P port of the No. The A port of the No. 1 three-position three-way reversing valve 4 is connected to one oil port of the hydraulic cylinder 6, and the other oil port of the hydraulic cylinder 6 is connected to the No. 2 three-position three-way reversing valve 5. Port A is connected to the pipeline, one end of the piston rod of the hydraulic cylinder 6 is connected to the swash plate of the hydraulic pump 7 by a ball joint, the oil outlet of the charge pump 8 is connected to the oil inlet of the first relief valve 9, and the two-position two-way reversing The P port of the valve 10 is connected with the pipeline, and the A port of the two-position two-way reversing valve 10 is connected to the oil inlet of the No. 1 check valve 11, the oil outlet of the No. 2 relief valve 12, and the oil inlet of the No. 2 check valve 13. , No. 3 overflow valve 14 oil outlet, No. 3 check valve 15 oil inlet pipeline connection, No. 3 check valve 15 oil outlet is connected with the external port M1 pipeline of hydraulic pump component Ⅰ, hydraulic pump 7 One oil port is connected with the oil outlet of No. 1 check valve 11, the oil inlet of No. 2 relief valve 12, and the external port M2 of hydraulic pump assembly I, and the other oil port of hydraulic pump 7 is connected with No. 2 check valve 13 The oil outlet, No. 3 relief valve 14 The oil inlet is connected with the external port M3 of the hydraulic pump assembly I, the oil inlet of the charge pump 8 is connected with the external port L2 of the hydraulic pump assembly I, and the No. 1 overflow The oil outlet of the flow valve 9 is connected with the external port L3 of the hydraulic pump assembly I.

Referring to accompanying drawing 2, control valve group II includes: No. 4 overflow valve 16, No. 3 three-position three-way reversing valve 17, No. 1 two-position four-way reversing valve 18, No. 1 two-position three-way reversing valve 19 , No. 2 two-position three-way directional control valve 20, No. 2 two-position four-way directional control valve 21, No. 1 two-position four-way hydraulic pilot directional control valve 22, No. 2 two-position four-way hydraulic pilot directional control valve 23, five No. relief valve 24. Among them, No. 3 three-position three-way reversing valve 17, No. one two-position four-way reversing valve 18, No. one two-position three-way reversing valve 19 and No. two two-position four-way reversing valve 21 are all electromagnetic reversing valves. valve; No. 4 relief valve 16 and No. 5 relief valve 24 are direct-acting relief valves; No. 2 two-position three-way reversing valve 20, No. The four-way hydraulic pilot reversing valve 23 is a hydraulic pilot reversing valve.

Referring to attached drawing 2, the T port of the No. 3 three-position three-way reversing valve 17 is connected to the oil inlet pipeline of the No. 4 relief valve 16, and the oil outlet of the No. 4 relief valve 16 is connected to the external port T1 of the control valve group II Pipeline connection, the P port of No. 3 three-position three-way reversing valve 17 is connected with the external port A of control valve group II, and the P port of No. two two-position three-way reversing valve 20. The B port of the reversing valve 17 and the external port B of the control valve group II, the T port of the No. 2 two-position three-way reversing valve 20, the P port of the No. The T port of the one-position four-way hydraulic pilot reversing valve 23 is connected with the pipeline, the B port of the No. 2 two-position three-way reversing valve 20 is connected with the T port of the No. The P port of the four-way hydraulic pilot reversing valve 23 is connected with the pipeline, the P port of the No. 1 two-position four-way reversing valve 18 is connected to the external port G of the control valve group II, and the P port of the No. port, the P port of the No. The T port of the one-position four-way reversing valve 21 is connected with the external port T2 of the control valve group II, and the A port of the No. The control port X, No. 5 relief valve 24 oil inlet, and the external port D1 of the control valve group II are connected to the pipeline, and the B port of the No. 1 2-position 4-way reversing valve 18 is connected to the No. 2 2-position 4-way hydraulic pilot reversing valve. The control port Y of the valve 23 is connected with the pipeline, the T port of the No. 1 two-position three-way reversing valve 19 is connected with the control port of the No. Port A of 21 is connected to the control port X pipeline of No. 1 two-position four-way hydraulic pilot control valve 22, and B port of No. two two-position four-way control valve 21 is connected to No. The control port Y of No. 22 is connected to the Y pipeline, and the B port of the No. 1 two-position four-way hydraulic pilot reversing valve 22 is connected to the external port D5 of the control valve group II. Port A is connected to the external port D4 of the control valve group II, the A port of the No. Port B of the pilot reversing valve 23 is connected to the external port D3 of the control valve group II, and the oil outlet of No. 5 relief valve 24 is connected to the external port T3 of the control valve group II.

Referring to accompanying drawing 3, controller 30 already has products, and concrete selection can be decided according to actual situation, and the controller model used here is HY-TTC200-CD-538K-2.4M-WD00-000. The controller 30 is used to receive the output signal of the displacement sensor s, and simultaneously control No. 1 three-position three-way reversing valve 4, No. two three-position three-way reversing valve 5, two-position two-way reversing valve 10, and No. 3 three-position The working positions of the three-way reversing valve 17, the No. 1 two-position four-way reversing valve 18, the No. 1 two-position three-way reversing valve 19, and the second two-position four-way reversing valve 21.

Referring to accompanying drawing 3, the No. 1 three-position three-way reversing valve 4 is an electromagnetic reversing valve, operated by an electromagnet, and reset by a spring, and the input ends of the electromagnetic coils in the electromagnets at both ends are respectively connected to the ports of the controller 30 by wires LA00 and the port LA01 of the controller 30; No. two three-position three-way reversing valve 5 is an electromagnetic reversing valve, and the input ends of the electromagnetic coils in the electromagnets at both ends are respectively connected to the port LA02 and the control of the controller 30 by wires. The port LA03 of the device 30; the other end of the hydraulic cylinder 6 away from the hydraulic pump 7 is installed with a displacement sensor s, the cylinder body of the hydraulic cylinder is mechanically fixed on the housing of the hydraulic pump assembly I, and the output signal of the displacement sensor s is passed through the wire Connected to the port EAD00 of the controller 30; the two-position two-way reversing valve 10 is an electromagnetic reversing valve, and the input end of the electromagnetic coil in the electromagnet is connected to the port LA04 of the controller 30 through a wire; three three-position three-way Reversing valve 17, No. 1 2-position 4-way reversing valve 18, No. 1 2-position 3-way reversing valve 19 and No. 2 2-position 4-way reversing valve 21 are all electromagnetic reversing valves; No. 3 3-position 3-way The input ends of the electromagnetic coils at both ends of the reversing valve 17 are respectively connected to the port LA05 of the controller 30 and the port LA06 of the controller 30 by electric wires; The port LA07 of controller 30; the input end of the electromagnetic coil of No. 1 two-position three-way reversing valve 19 is connected to the port LA24 of controller 30 by electric wire; The input end of the electromagnetic coil of No. two two-position four-way reversing valve 21 It is connected to the port LA25 of the controller 30 by a wire.

Referring to accompanying drawing 3, the external ports T1, T2, T3 of the control valve group II are all connected to the oil tank 29 through pipelines; the external ports L1, L2, L3 of the hydraulic pump assembly I are all connected to the oil tank 29 through pipelines; the hydraulic pump assembly The external port M1 of I is connected to the external port G of the control valve group II by the pipeline, the external port M2 of the hydraulic pump component I is connected to the external port A of the control valve group II by the pipeline, and the external port M3 of the hydraulic pump component I is connected to the control valve The external port B of group II is connected to the pipeline.

Referring to accompanying drawing 3, the external port D1 of the control valve group II is connected to the casing oil discharge port of the left wheel hub motor 26 and the casing oil discharge port of the right wheel hub motor 27; the external connection port D2 of the control valve group II is connected to the left hub motor One oil port of the motor 26 is connected to the pipeline; the external port D3 of the control valve group II is connected to the other oil port of the left hub motor 26; the external port D4 of the control valve group II is connected to an oil port of the right hub motor 27 The external port D5 of the control valve group II is connected with another oil port of the right wheel hub motor 27; Adopt spline pair connection between them or both are the same axle; for the same axis;

Referring to Figure 3, the power take-off device 1 and the output shaft 2 of the power take-off device provide the motive force for the hydraulic auxiliary drive system, and drive the hydraulic pump 7 and the charge pump 8 to rotate; the hydraulic pump 7 is a two-way variable hydraulic pump, and its two oil ports can be It is an oil inlet or an oil outlet, but there is only one oil outlet and one oil inlet when working. The displacement of the hydraulic pump 7 is adjusted by the piston rod of the hydraulic cylinder 6 driving the opening of the swash plate; The shell of the cylinder 6 is fixed mechanically, the displacement sensor s transmits the displacement of the piston rod to the controller 30, and the controller 30 obtains the feedback displacement of the hydraulic pump 7 through the signal value of the displacement sensor s, thereby forming a closed-loop control; 8 is a one-way quantitative hydraulic pump, its function is to supply oil to the system circuit, and at the same time provide control oil for the control valve group II; No. 1 check valve 11, No. 2 overflow valve 12, No. 2 check valve 13 and No. 3 No. overflow valve 14 is used to only allow oil to flow from the A port of the two-position two-way reversing valve 10 to the main oil circuit, while ensuring the safety of the main oil circuit; when the two-position two-way reversing valve 10 is switched to the lower position , the output oil of the charge pump 8 flows through the P port of the two-position two-way reversing valve 10 to the oil inlet port of the No. 3 check valve 15, and then outputs from the external port M1 of the hydraulic pump component I after passing through the No. , so as to provide control oil for No. 1 2-position 4-way hydraulic pilot directional valve 22 and No. 2 2-position 4-way hydraulic pilot directional valve 23, and provide control oil for No. The control oil is provided by the reversing valve 20 (at this time, the No. 1 two-position three-way reversing valve 19 is switched to the right position). The first relief valve 9 is arranged between the oil outlet of the charge pump 8 and the oil tank 29 to limit the pressure of the oil outlet of the charge pump 8 so as to protect the charge pump 8 .

Referring to accompanying drawing 3, the piston movement of hydraulic cylinder 6 is controlled by controlling the working positions of No. 1 three-position three-way reversing valve 4 and No. two three-position three-way reversing valve 5, thereby changing the opening degree of the swash plate of hydraulic pump 7 In order to achieve the purpose of changing the displacement, the input oil of No. 1 three-position three-way reversing valve 4 and No. two three-position three-way reversing valve 5 is provided by charge pump 8 . When the controller 30 outputs a control command to switch the No. 1 three-position three-way reversing valve 4 to the lower position, and simultaneously switch the No. two three-position three-way reversing valve 5 to the lower position, the hydraulic cylinder 6 is disconnected at this time. The oil circuit between the oil pumps 8 and both ends of the hydraulic cylinder 6 are in communication with the oil tank 29, and the displacement of the hydraulic pump 7 is 0 at this moment. When using the controller 30 to switch the No. 1 three-position three-way reversing valve 4 and the No. two three-position three-way reversing valve 5 to the neutral position, the hydraulic pressure at both ends of the piston of the hydraulic cylinder 6 is maintained at this time, which means Keep the displacement of the hydraulic pump 7 stable. If the No. 1 three-position three-way reversing valve 4 is switched to the upper position, and the No. 2 three-position three-way reversing valve 5 is switched to the lower position, the piston of the hydraulic cylinder 6 moves down, and the displacement signal value of the hydraulic pump 7 at this time It gradually increases in the range of 0 to +1. If the No. 1 three-position three-way reversing valve 4 is switched to the lower position, and the No. 2 three-position three-way reversing valve 5 is switched to the upper position, at this time, the piston of the hydraulic cylinder 6 moves up, and the displacement signal value of the hydraulic pump 7 Gradually increase in the range of -1 to 0 (absolute value increases). The controller 30 obtains the displacement of the piston rod of the hydraulic cylinder 6 through the displacement sensor s installed on the piston rod of the hydraulic cylinder 6, and compares it with a target value to form a closed-loop control.

Referring to accompanying drawing 3, when the temperature of the oil in the system rises to a certain threshold, the controller 30 outputs a control command to switch the working position of the three-position three-way reversing valve 17 of No. Add oil to the main oil circuit to achieve the purpose of cooling. Specifically: when the vehicle is running forward, the No. 3 three-position three-way reversing valve 17 is switched to the upper position, and when the vehicle is reversed, the No. three three-position three-way reversing valve 17 is switched to the lower position.

The control signal is output by the controller 30, so that No. 1 three-position three-way reversing valve 4, No. two three-position three-way reversing valve 5, two-position two-way reversing valve 10, and No. three three-position three-way reversing valve 17 , No. 1, 2-position, 4-way reversing valve 18, No. 1, 2-position, 3-way reversing valve 19, and No. 2, 2-position, 4-way reversing valve 21 are in different working positions, enabling the system to realize three different operating modes, That is, freewheel mode, auxiliary drive mode and bypass mode, which are described in detail below.

Free wheel mode:

Referring to accompanying drawing 3, the auxiliary drive system of the hydraulic hub motor is working in the free wheel mode at this moment.

The controller 30 outputs control commands to switch No. 1 three-position three-way reversing valve 4 to the lower position, No. two three-position three-way reversing valve 5 to the lower position, and two-position two-way reversing valve 10 to the lower position. No. 3-position 3-way reversing valve 17 is switched to the middle position, No. 1 2-position 4-way directional valve 18 is switched to the upper position, No. 1 2-position 3-way directional valve 19 is switched to the left position, and No. Direction valve 21 is switched to the down position. The charge pump 8 draws oil from the fuel tank 29 through the external port L2 of the hydraulic pump component I, and passes through the two-position two-way reversing valve 10, the third check valve 15, the external port M1 of the hydraulic pump component I and the control valve group II. The external port G passes through the No. 1 two-position four-way reversing valve 18 and the No. two two-position four-way reversing valve 21 respectively, and then acts on the X end of the No. 2 two-position four-way hydraulic pilot reversing valve 23 and the No. 1 two-position At the Y end of the four-way hydraulic pilot reversing valve 22, switch the No. 1 two-position four-way hydraulic pilot reversing valve 22 to the lower position, and switch the No. 2 two-position four-way hydraulic pilot reversing valve 23 to the upper position, resulting in the left wheel hub motor 26 and the right hub motor 27 are disconnected from the main oil circuit; at the same time, the A port of the No. 1 two-position four-way reversing valve 18 is sent to the shells of the left hub motor 26 and the right hub motor 27 through the external port D1 of the control valve group II body, so that the plungers of the left hub motor 26 and the right hub motor 27 are retracted and separated from the housing, and the No. 5 overflow valve 24 is used to limit the pressure within an appropriate range to ensure safety; at this time, the hydraulic cylinder 6. Both ends of the piston are in communication with the oil tank 29, and the displacement of the hydraulic pump 7 is 0.

Secondary drive mode:

Referring to accompanying drawing 4, at this moment the auxiliary drive system of the hydraulic hub motor works in the auxiliary drive mode.

The control command is output by the controller 30 to switch the two-position two-way reversing valve 10 to the lower position, and the working position of the three-position three-way reversing valve 17 of No. The first two-position four-way reversing valve 18 is switched to the lower position, the first two-position three-way reversing valve 19 is switched to the left position, and the second two-position four-way reversing valve 21 is switched to the upper position; at this time , the No. 2 two-position three-way reversing valve 20 works in the upper position; under the action of the control oil, the No. 1 two-position four-way hydraulic pilot reversing valve 22 switches to the upper position, and the No. The valve 23 is switched to the lower position, and at this moment, the left hub motor 26 and the right hub motor 27 are connected with the main oil circuit. The hydraulic pump 7, the No. 2 two-position three-way reversing valve 20, the No. two two-position four-way hydraulic pilot reversing valve 23 and the left wheel hub motor 26 form a closed-loop circuit to drive the left wheel hub motor 26 to rotate, thereby driving the left front wheel 25 running; in like manner, hydraulic pump 7, No. 2 two-position three-way reversing valve 20, No. one two-position four-way hydraulic pilot reversing valve 22 and right hub motor 27 form a circuit, thereby driving right front wheel 28 to travel. The controller 30 controls the displacement of the piston of the hydraulic cylinder 6 by switching the working positions of the No. 1 three-position three-way reversing valve 4 and the No. 2 three-position three-way reversing valve 5, so as to achieve the purpose of adjusting the displacement of the hydraulic pump 7. Specifically It is: if the first three-position three-way reversing valve 4 is switched to the upper position, and the second three-position three-way reversing valve 5 is switched to the lower position, then the hydraulic pump 7 drives the left hub motor 26 and the right hub motor 27 to run forward , at this time the vehicle is running forward; if the No. 1 three-position three-way reversing valve 4 is switched to the lower position, and the No. 2 three-position three-way reversing valve 5 is switched to the upper position, the hydraulic pump 7 drives the left wheel hub motor 26 and the right The wheel hub motor 27 runs in the opposite direction, and the vehicle runs backwards at this moment. The working positions of No. 1 three-position three-way reversing valve 4 and No. two three-position three-way reversing valve 5 are determined by the required displacement of hydraulic pump 7 .

Bypass mode:

Referring to accompanying drawing 5, the hydraulic hub motor auxiliary drive system works in bypass mode at this moment.

When the system works in the auxiliary drive mode, when the vehicle is shifting gears, the hydraulic hub motor auxiliary drive system is switched to the bypass mode. At this time, only the output signal of the controller 30 needs to be changed to the first two-position three-way reversing valve 19 The working position of other parts (such as reversing valves, hydraulic pumps, motors, etc.) remains unchanged. Since the vehicle has only one reverse gear, there is no gear shifting process when the vehicle is running in reverse. In the process of switching from reverse gear to forward gear, it needs to be switched when the vehicle speed is zero. Therefore, when the vehicle is running in reverse, the hydraulic hub motor assists the drive. The system does not have a bypass mode. When the vehicle shifts gears while moving forward, the No. 1 two-position three-way reversing valve 19 is switched to the right position. No. 2-position 3-way reversing valve 20 is switched to the lower position, at this time, the high-pressure oil delivered to the left hub motor 26 and the right hub motor 27 is cut off, and the hydraulic hub motor auxiliary drive system works in bypass mode. The positions of the No. 1 three-position three-way reversing valve 4 and the No. two three-position three-way reversing valve 5 at the moment before switching to the bypass mode remain unchanged.

All the components used in the present invention have existing products, and the specific selection needs to be determined in conjunction with vehicle parameters and design requirements. Table 1 is the vehicle basic parameters and design requirements of a certain heavy vehicle, and Table 2 is the parameters of the selected main hydraulic components.

Table 1 Basic parameters and design requirements of the vehicle

Table 2 Parameters of main hydraulic components

In order to verify the feasibility of the hydraulic hub motor auxiliary drive system of the present invention, the contribution of the present invention to improving vehicle dynamics is tested through simulation.

Referring to accompanying drawing 6, the figure shows the increase ratio of vehicle dynamics when the hydraulic hub motor auxiliary drive system according to the present invention is adopted. In the figure, the solid line represents the change curve of the traction force increase ratio with the road surface adhesion coefficient, and the dotted line represents the change curve of the vehicle maximum gradeability increase ratio with the road surface adhesion coefficient. It can be seen that when the hydraulic wheel hub motor auxiliary drive system of the present invention is adopted, the maximum gradeability and traction of the vehicle are significantly improved, and the effect is more obvious on roads with low adhesion coefficient.

The hydraulic hub motor auxiliary drive system of the present invention can realize the free wheel mode, the auxiliary drive mode and the bypass mode, and the working positions of the reversing valve in the control valve group II in each working mode are shown in Table 3 below:

Table 3 Working position of reversing valve in each working mode

The principle and characteristics of the hydraulic hub motor auxiliary drive system:

1. The controller 30 determines the working mode of the system according to the vehicle speed and the position signal of the accelerator pedal, and realizes different working modes by switching the working positions of the reversing valves in the control valve group II. The working positions of the valve 4 and the No. 2 three-position three-way reversing valve 5 are used to adjust the displacement of the hydraulic pump 7 to meet the driving demand.

2. When the vehicle is driving on a road with a low adhesion coefficient or climbing a slope, the controller 30 switches the working positions of the reversing valves in the control valve group II to make the system work in the auxiliary driving mode. At this time, the front wheels of the vehicle become driving wheels , increasing the driving force of the vehicle.

3. When the vehicle is driving on a good road, the hydraulic hub motor auxiliary drive system works in freewheel mode, and the front wheels are driven wheels at this time, which helps to improve the traction efficiency of the vehicle.

4. When the vehicle shifts gears, the hydraulic hub motor auxiliary drive system works in bypass mode, thus ensuring smooth gear shifting.

5. The hydraulic hub motor auxiliary drive system of the present invention will inevitably generate a certain amount of heat during operation. In order to ensure the reliable operation of the system, the purpose of cooling can be achieved by switching the working position of the No. 3, 3-position, 3-way reversing valve 17.

According to the above principles and characteristics, it can be seen that on the basis of the traditional rear wheel drive vehicle, the present invention converts the vehicle into a four-wheel drive system by adding a set of hydraulic hub motor auxiliary drive system, which helps to improve the power performance of the vehicle. At the same time, the control valve group II structure of the present invention can meet the actual engineering requirements, can effectively control the work of the large-displacement hydraulic wheel hub motor, and make it output drive torque smoothly, and has good adaptability to working conditions.

Claims (3)

1. Hydraulic hub motor auxiliary drive system, including hydraulic pump assembly (I), control valve group (II), controller (30), power take-off device (1), power take-off device output shaft (2), left front wheel ( 25), left wheel hub motor (26), right wheel hub motor (27), right front wheel (28), oil tank (29), power take-off device output shaft (2) and hydraulic pump assembly input in hydraulic pump assembly (Ⅰ) The shafts (3) are connected by spline pairs or universal joints, the external ports T1, T2, and T3 of the control valve group (II) are all connected to the oil tank (29) through pipelines, and the external ports of the hydraulic pump assembly (I) Ports L1, L2, and L3 are all connected to the fuel tank (29) through pipelines, the external port M1 of the hydraulic pump assembly (I) and the external port G of the control valve group (II) are connected through pipelines, and the external connection port G of the hydraulic pump assembly (I) The external port M2 is connected to the external port A of the control valve group (II), the external port M3 of the hydraulic pump assembly (I) is connected to the external port B of the control valve group (II), and the external port B of the control valve group (II) The external port D1 is connected with the casing oil discharge port of the left hub motor (26) and the casing oil discharge port of the right hub motor (27), and the external port D2 of the control valve group (II) is connected with the left hub motor (26) One oil port of the control valve group (II) is connected with the external port D3 of the left hub motor (26), and the external port D4 of the control valve group (II) is connected with the right hub motor (27 ), the external port D5 of the control valve group (II) is connected to the other oil port of the right hub motor (27), and the rotor shaft of the left hub motor (26) is connected to the left front wheel (25 ) transmission shafts are connected by a spline pair or both are the same shaft, and the rotor shaft of the right hub motor (27) and the transmission shaft of the right front wheel (28) are connected by a spline pair or both are the same root shaft, the controller (30) is connected to the hydraulic pump assembly (I) through a signal line, the controller (30) is connected to the control valve group (II) circuit, and the controller (30) is connected to the hydraulic pump assembly (I) circuit, It is characterized by: The control valve group (II) includes: No. 4 overflow valve (16), No. 3 three-position three-way reversing valve (17), No. 1 two-position four-way reversing valve (18), No. 1 two-position three-way reversing valve Directional valve (19), No. 2 2-position 3-way directional valve (20), No. 2 2-position 4-way directional valve (21), No. 1 2-position 4-way hydraulic pilot directional valve (22), No. 2 4-position hydraulic pilot directional control valve (23) and No. 5 relief valve (24), of which, No. 3 3-position 3-way directional valve (17), No. 1 2-position 4-way directional valve (18), and No. 1 No. 2-position 3-way directional valve (19) and No. 2 2-position 4-way directional valve (21) are electromagnetic directional valves, and No. 4 overflow valve (16) and No. 5 overflow valve (24) are direct Dynamic relief valve, No. 2 two-position three-way reversing valve (20), No. one two-position four-way hydraulic pilot reversing valve (22) and No. two two-position four-way hydraulic pilot reversing valve (23) are all Hydraulic pilot reversing valve; The T port of the No. 3 three-position three-way reversing valve (17) is connected to the oil inlet pipeline of the No. 4 relief valve (16), and the oil outlet of the No. 4 relief valve (16) is connected to the control valve group (II) The external port T1 of the external port T1 is connected with the pipeline, the P port of the third three-position three-way reversing valve (17) is connected to the external port A of the control valve group (II), and the P port of the second two-position three-way reversing valve (20) Pipeline connection, port B of No. 3 three-position three-way reversing valve (17) and external port B of control valve group (II), T port of No. two two-position three-way reversing valve (20), No. The P port of the four-position hydraulic pilot control valve (22), the T port of the No. 2 two-position four-way hydraulic pilot control valve (23), the B The port is connected to the T port of No. 1 two-position four-way hydraulic pilot control valve (22) and the P port of No. two two-position four-way hydraulic pilot control valve (23). The P port of (18) is connected to the external port G of the control valve group (II), the P port of the No. 1 two-position three-way reversing valve (19), and the P port of the No. The T port of No. 1 2-position 4-way reversing valve (18) is connected with the A port of No. 1 2-position 3-way reversing valve (19), and the T port of No. 2 2-position 4-way reversing valve (21). , The external port T2 of the control valve group (II) is connected with the pipeline, and the A port of the No. 1 two-position four-way reversing valve (18) is connected to the control port X of the No. two two-position four-way hydraulic pilot reversing valve (23). The oil inlet port of No. 5 relief valve (24) is connected with the external port D1 of the control valve group (II), and the B port of No. 1 2-position 4-way reversing valve (18) is connected with No. 2 2-position 4-way hydraulic pressure port. The control port Y of the pilot reversing valve (23) is connected with the pipeline, and the T port of the No. 1 two-position three-way reversing valve (19) is connected with the control port of the No. two two-position three-way reversing valve (20). Port A of the No. 2 2-position 4-way directional control valve (21) is connected to the control port X pipeline of the No. 1 2-position 4-way directional control valve (22), and the No. 2 2-position 4-way directional control valve (21) The B port of the No. 1 two-position four-way hydraulic pilot control valve (22) is connected to the Y pipeline of the control port, and the B port of the No. 1 two-position four-way hydraulic pilot control valve (22) is connected to the control valve group (Ⅱ) The external port D5 of the No. 1 two-position four-way hydraulic pilot reversing valve (22) is connected to the external port D4 of the control valve group (II), and the second two-position four-way hydraulic pilot reversing valve Port A of the valve (23) is connected to the external port D2 of the control valve group (II), and port B of the No. 2 two-position four-way hydraulic pilot control valve (23) is connected to the external port D3 of the control valve group (II). Pipeline connection, the oil outlet of No. 5 overflow valve (24) is connected with the external port T3 pipeline of the control valve group (II). 2. The hydraulic wheel hub motor auxiliary drive system according to claim 1, characterized in that the circuit connection between the controller (30) and the control valve group (II) refers to: The input ends of the electromagnetic coils at both ends of the No. 3 three-position three-way reversing valve (17) in the control valve group (II) are respectively connected to the port LA05 of the controller (30) and the port LA06 of the controller (30) through wires; The input end of the electromagnetic coil of the No. 1 two-position four-way reversing valve (18) in the control valve group (II) is connected to the port LA07 of the controller (30) through a wire; The input end of the electromagnetic coil of the No. 1 two-position three-way reversing valve (19) in the control valve group (II) is connected to the port LA24 of the controller (30) through a wire; The input end of the electromagnetic coil of the second two-position four-way reversing valve (21) in the control valve group (II) is connected to the port LA25 of the controller (30) through a wire. 3. The hydraulic hub motor auxiliary drive system according to claim 1, characterized in that the circuit connection between the controller (30) and the hydraulic pump assembly (I) refers to: The No. 1 three-position three-way reversing valve (4) in the hydraulic pump assembly (I) is an electromagnetic reversing valve, and the input ends of the electromagnetic coils in the electromagnets at both ends are respectively connected to the ports of the controller (30) through wires LA00 and the port LA01 of the controller (30); The No. 2 three-position three-way reversing valve (5) in the hydraulic pump assembly (I) is an electromagnetic reversing valve, and the input ends of the electromagnetic coils in the electromagnets at both ends are respectively connected to the ports of the controller (30) through wires Port LA03 of LA02 and controller (30); The end of the hydraulic cylinder (6) in the hydraulic pump assembly (I) away from the hydraulic pump (7) is equipped with a displacement sensor (s), and the output signal of the displacement sensor (s) is connected to the port of the controller (30) through a signal line EAD00; The two-position two-way reversing valve (10) in the hydraulic pump assembly (I) is an electromagnetic reversing valve, and the input end of the electromagnetic coil in its electromagnet is connected to the port LA04 of the controller (30) by electric wires.