阅读说明：本技术 双行整杆甘蔗收获机电液比例液压系统 (Electro-hydraulic proportional hydraulic system of double-row whole-stalk sugarcane harvester ) 是由 郑海燕 倪伟 李志敏 郝宁 辛晓敏 蒯小耿 于 2021-08-16 设计创作，主要内容包括：本发明涉及电液比例控制系统设计技术领域,具体为一种双行整杆甘蔗收获机电液比例液压系统,该液压系统包括双联变量柱塞泵液压系统、三联齿轮泵液压系统、单联变量柱塞泵液压系统；双联变量柱塞泵液压系统包括两个回路；三联齿轮泵液压系统由三个子回路组成。所述电液比例甘蔗收获机液压系统,利用电控变量柱塞泵、负载反馈比例换向阀的模块化控制技术,具有卓越操作的比例性和微动性,实现与输出流量无关的更低压损,均可以得到与负载无关的流量控制,使得各执行机构的速度均可稳定调节,具有良好的调速特性,且系统集成度高、具有电动和手动双重控制,操作方便,发热少、冲击小可有效提高整机性能并降低冷却需求和燃油消耗。(The invention relates to the technical field of electro-hydraulic proportional control system design, in particular to an electro-hydraulic proportional hydraulic system of a double-row whole-stalk sugarcane harvester, which comprises a double-linkage variable plunger pump hydraulic system, a triple gear pump hydraulic system and a single-linkage variable plunger pump hydraulic system; the duplex variable plunger pump hydraulic system comprises two loops; the hydraulic system of the triple gear pump consists of three sub-circuits. The hydraulic system of the electro-hydraulic proportional sugarcane harvester utilizes a modular control technology of an electric control variable plunger pump and a load feedback proportional reversing valve, has excellent proportionality and micromobility in operation, realizes lower pressure loss irrelevant to output flow, can obtain flow control irrelevant to load, ensures that the speed of each actuating mechanism can be stably adjusted, has good speed regulation characteristic, has high system integration level, has electric and manual dual control, is convenient to operate, generates less heat and has small impact, and the performance of the whole machine can be effectively improved and the cooling demand and the fuel consumption can be reduced.)

1. An electro-hydraulic proportional hydraulic system of a double-row whole-stalk sugarcane harvester is characterized by comprising a duplex variable plunger pump hydraulic system, a triple gear pump hydraulic system and a single-link variable plunger pump hydraulic system;

the hydraulic system of the double-linked variable plunger pump comprises two closed loops, wherein the first closed loop consists of a first single-linked electrically controlled variable plunger pump (1-1), a first flushing valve (2), a diverter valve (4) and two cutter motors (5), a working oil port A of the first single-linked electrically controlled variable plunger pump (1-1) is connected with an oil inlet of the diverter valve (4), two oil outlets of the diverter valve (4) are respectively connected with oil inlets of the two cutter motors (5), the first flushing valve (2) is connected between working oil ports A, B of the first single-linked electrically controlled variable plunger pump (1-1) in parallel, and oil outlets of the two cutter motors (5) are connected with a working oil port B of the first single-linked electrically controlled variable plunger pump (1-1);

the second closed loop consists of a second single-connection electric control variable plunger pump (1-2), a second flushing valve (3) and a second front channel motor (6); a working oil port A of the second single-connection electric control variable plunger pump (1-2) is connected with an oil inlet of the second front channel motor (6), and the second flushing valve (3) is connected in parallel between the working oil ports A, B of the second single-connection electric control variable plunger pump (1-2);

the hydraulic system of the single-connection variable plunger pump is a closed system consisting of a third single-connection electric control variable plunger pump (7) and a walking motor (8), and an oil inlet and an oil outlet A, B of the walking motor (8) are respectively connected with a working oil port A, B of the third single-connection electric control variable plunger pump (7);

the hydraulic system of the triple gear pump consists of three sub-circuits, wherein the first sub-circuit comprises a first gear pump (9-1), a second PVG32-1 one-connection load feedback proportional reversing valve (19-2) connected with the first gear pump (9-1), a first rear channel motor (24) and a second rear channel motor (25) which are sequentially connected to an oil outlet of the second PVG32-1 one-connection load feedback proportional reversing valve (19-2), and a first speed regulating valve (28) is connected in parallel between the first rear channel motor (24) and the second rear channel motor (25) to form a secondary speed regulating circuit;

the second sub-loop is characterized in that a tip cutting motor (21), a pressing down motor (22), a second speed regulating valve (29) and five sugarcane supporting motors (23) are controlled by a second gear pump (9-2) and a first PVG32-1 combined load feedback proportional reversing valve (19-1), wherein the tip cutting motor (21) is connected with the pressing down motor (22) in parallel and then connected with the five sugarcane supporting motors (23) in series, and the pressing down motor (22) is connected with the second speed regulating valve (29) in series, so that secondary speed regulation of the pressing down motor (22) is realized;

the third sub-loop is characterized in that a priority valve (10) and an ECO80-5 quintuplet load sensitive valve group (12) are controlled by a third gear pump (9-3), wherein the ECO80-5 quintuplet load sensitive valve group (12) respectively controls a first front channel motor (20), a sugarcane bin oil cylinder (13), a header oil cylinder (14), a tip cutting oil cylinder (15) and a sugarcane supporting oil cylinder (16); the priority valve (10) is connected with a load-sensitive steering gear (11) and a steering oil cylinder (27).

2. The electro-hydraulic proportional hydraulic system of a double-row whole-stalk sugarcane harvester according to claim 1, characterized in that the hydraulic system is connected with pressure sensors (26) at an A.B oil outlet, an oil supplementing pressure port, a first PVG 32-1-linked load feedback proportional reversing valve (19-1), a second PVG 32-1-linked load feedback proportional reversing valve (19-2) and a pressure port of an ECO 80-5-linked load sensitive valve group (12) of each electrically controlled variable plunger pump, and signals of the pressure sensors (26) are introduced into a control screen in a cab.

3. The electro-hydraulic proportional hydraulic system of a double-row whole-stalk sugarcane harvester as claimed in claim 1, characterized in that an electric control handle for controlling a third single-linkage electric control variable plunger pump (7) is arranged in the cab; and meanwhile, an electric foot brake for controlling the power supply of the third single-connection electric control variable plunger pump (7) is arranged in the cab.

4. The electro-hydraulic proportional hydraulic system of a double row whole cane harvester according to claim 1, characterized in that the first front channel motor (20) is controlled electrically and manually: the control of a control valve working module corresponding to a first front channel motor (20) in an ECO80-5 five-way load sensitive valve group (12) is realized through a control screen in a cab; and manual control is realized through a flow adjusting screw on a control valve working module corresponding to the first front channel motor (20) in the ECO80-5 five-way load sensitive valve group.

5. The electro-hydraulic proportional hydraulic system of the double-row whole-stalk sugarcane harvester according to claim 1, characterized in that a first one-way balance valve (17-1), a second one-way balance valve (17-2) and a third one-way balance valve (17-3) are respectively connected in series on control oil paths of a five-way load-sensitive valve bank (12) of the ECO80-5 corresponding to a header oil cylinder (14), a tip cutting oil cylinder (15) and a sugarcane supporting oil cylinder (16).

6. The electro-hydraulic proportional hydraulic system of a double-row whole-stalk sugarcane harvester according to claim 1 or 5, characterized in that a control oil path of a corresponding sugarcane bin oil cylinder (13) in the ECO80-5 five-path load-sensitive valve group (12) is connected in series with a one-way hydraulic lock (18).

7. The electro-hydraulic proportional hydraulic system of the double-row whole-stalk sugarcane harvester according to claim 1 or 5, characterized in that four working modules in the ECO80-5 five-way load-sensitive valve bank (12) for controlling the sugarcane bin cylinder (13), the header cylinder (14), the tip cutting cylinder (15) and the sugarcane supporting cylinder (16) adopt two modes of electric control and manual control, and the electric control is realized on the corresponding working modules of the cylinder control valves in the ECO80-5 five-way load-sensitive valve bank (12) through a control screen in a cab; and manual control is realized through flow adjusting screws on working modules of corresponding oil cylinder control valves in the ECO80-5 five-way load sensitive valve bank.

Technical Field

The invention relates to the technical field of design of electro-hydraulic proportional control systems, in particular to an electro-hydraulic proportional hydraulic system of a double-row whole-stalk sugarcane harvester.

Background

In recent years, agricultural mechanization in China is rapidly developed, sugarcane harvesters are developed for many years, some unit batches are produced on an initial scale, but single-row cutting-off harvesting modes are more in terms of harvesting modes, and the double-row whole-stalk sugarcane harvester is still in a development stage due to complex structure, so that the harvester is suitable for different harvesting environments, the harvesting quality and efficiency are ensured, and a plurality of motors, oil cylinders and other execution elements such as a sugarcane supporting, tip cutting, tip pressing, cutting, leaf peeling, conveying, sugarcane bin and the like are required to be capable of conveniently adjusting the speed and are not influenced by each other. That is to say, the quality of the speed control design in the hydraulic system is the key to ensure the coordinated action of each component, and is one of the key technologies developed at present.

At present, in order to reduce the manufacturing cost, a plurality of paths of manual control valves and a constant delivery pump speed regulating system or a variable delivery pump are adopted in a hydraulic system of the sugarcane machine, and the system has the following defects: (1) the reversing impact causes large system pressure impact, and the service life of a hydraulic element is seriously influenced; (2) the manual control valve is arranged in the cab, and certain potential safety hazards exist although the operation is convenient; (3) the speed regulation of the execution element is inconvenient and unstable, the flow regulation effect is achieved through oil inlet throttling or oil return throttling, but the redundant flow of the throttling speed regulation loop flows back to the oil tank through the overflow valve, so that the system is seriously heated, the flow can change along with the change of the load, the speed regulation is unstable, and the product reliability is not high on the whole.

In conclusion, with the continuous development of future intelligent high-end agricultural equipment, the application of the electro-hydraulic control technology in the hydraulic system of the sugarcane harvester tends to be researched and developed actively.

Disclosure of Invention

The invention provides an electro-hydraulic proportional hydraulic system of a double-row whole-stalk sugarcane harvester, which aims to solve the technical problems of large reversing pressure impact, inconvenient speed regulation, instability and the like of the hydraulic control system of the conventional double-row sugarcane harvester.

The invention is realized by adopting the following technical scheme: an electro-hydraulic proportional hydraulic system of a double-row whole-stalk sugarcane harvester comprises a duplex variable plunger pump hydraulic system, a triple gear pump hydraulic system and a single-duplex variable plunger pump hydraulic system;

the hydraulic system of the double-linkage variable plunger pump comprises two closed loops, wherein the first closed loop consists of a first single-linkage electric control variable plunger pump, a first flushing valve, a flow divider valve and two cutting knife motors, a working oil port A of the first single-linkage electric control variable plunger pump is connected with an oil inlet of the flow divider valve, two oil outlets of the flow divider valve are respectively connected with oil inlets of the two cutting knife motors, the first flushing valve is connected between working oil ports A, B of the first single-linkage electric control variable plunger pump in parallel, and oil outlets of the two cutting knife motors are connected with a working oil port B of the first single-linkage electric control variable plunger pump;

the second closed loop consists of a second single-connection electric control variable plunger pump, a second flushing valve and a second front channel motor; the working oil port A of the second single-connection electric control variable plunger pump is connected with the oil inlet of the second front channel motor, and the second flushing valve is connected between the working oil ports A, B of the second single-connection electric control variable plunger pump in parallel;

the hydraulic system of the single-connection variable plunger pump is a closed system consisting of a third single-connection electric control variable plunger pump and a walking motor, and an oil inlet and an oil outlet A, B of the walking motor are respectively connected with a working oil port A, B of the third single-connection electric control variable plunger pump;

the hydraulic system of the triple gear pump consists of three sub-circuits, wherein the first sub-circuit comprises a first gear pump, a second PVG32-1 one-connection load feedback proportional reversing valve connected with the first gear pump, and a first rear channel motor and a second rear channel motor which are sequentially connected to the oil outlet of the second PVG32-1 one-connection load feedback proportional reversing valve, and a first speed regulating valve is connected in parallel between the first rear channel motor and the second rear channel motor to form a secondary speed regulating circuit;

the second sub-loop is controlled by a second gear pump and a first PVG32-1 load feedback proportion reversing valve to control a tip cutting motor, a pressing motor, a second speed regulating valve and five sugarcane supporting motors, wherein the tip cutting motor and the pressing motor are connected in parallel and then connected in series with the five sugarcane supporting motors, and the pressing motor is connected in series with the second speed regulating valve to realize secondary speed regulation of the pressing motor;

the third sub-loop is controlled by a third gear pump to control a priority valve and an ECO80-5 quintuplet load sensitive valve bank, wherein the ECO80-5 quintuplet load sensitive valve bank respectively controls a first front channel motor, a sugarcane bin oil cylinder, a header oil cylinder, a tip cutting oil cylinder and a sugarcane supporting oil cylinder; the priority valve is connected with a load sensitive steering gear and a steering oil cylinder.

The defects of the prior art are as follows: at present, the hydraulic system suitable for the double-row whole-stalk sugarcane harvester in China is not designed completely, the hydraulic system is bloated, a hydraulic element cannot regulate speed or cannot regulate speed unstably, the control precision is low, the operation is inconvenient, the adaptability is poor, various control valves are arranged in a cab, certain potential safety hazards exist, and the like, and the harvesting quality, the harvesting efficiency and the reliability of the sugarcane harvester are influenced to a great extent.

The invention aims to solve the technical problems and designs an electro-hydraulic proportional hydraulic system of a double-row whole-stalk sugarcane harvester, which utilizes an electric control variable plunger pump and a load feedback proportional reversing valve, adopts modular control, has an electric control and manual dual control mode, and provides the maximum flexibility for system design and construction. The speed regulation of each motor and each oil cylinder can be easily realized on a central control screen in a cab, the speed regulation device has good speed regulation characteristic, the speed of each execution element is not influenced mutually, the device can be well adapted to various harvesting environments of a sugarcane field, the system integration level is high, the heating is less, the impact is small, the performance of the whole machine can be effectively improved, the cooling requirement and the fuel consumption are reduced, and the effects of energy conservation and noise reduction are achieved. Greatly improves the automatic harvesting level of the sugarcane harvester and the reliability of products.

1) The electro-hydraulic proportional control system utilizes an electric control variable plunger pump and a load feedback proportional reversing valve, adopts modular control, has an electric control and manual dual control mode, and provides the greatest flexibility for system design and construction. The speed regulation of each motor and each oil cylinder can be easily realized on a central control screen in a cab, the speed regulation device has good speed regulation characteristic, the speed of each execution element is not influenced mutually, and the speed regulation device can be well suitable for various harvesting environments of sugarcane fields.

2) The walking speed regulation braking system consists of an electric control variable plunger pump and a walking motor, the walking motor can rotate in two directions, the sugarcane harvester can move forwards and backwards, meanwhile, the speed of the walking motor can be regulated by regulating an electric control handle of the electric control variable plunger pump in a cab, and the movement speed regulation of the sugarcane harvester is realized. Meanwhile, an electric foot brake is arranged in the cab, so that the power supply of the single-connection electric control variable plunger pump can be cut off instantly, the emergency brake of the sugarcane harvester is realized, and the brake time can be controlled in a delayed manner.

3) A composite speed regulation system is controlled by a load feedback proportional reversing valve and a speed regulation valve, a first rear channel motor and a second rear access motor are connected in parallel between the two rear channel motors, after the speed regulation is carried out by utilizing a PVG32-1 load feedback proportional reversing valve, the two rear channel motors have different selected discharge capacities and different speeds, on the basis, if the speed regulation is further carried out on the second rear channel motor, the first speed regulation valve is adjusted, and the secondary speed regulation can be carried out on the second rear channel motor under the condition that the rotating speed of the first rear channel motor is not changed. The tip cutting motor and the pressing motor are connected in parallel and then connected in series with the five sugarcane supporting motors, the speed regulating valve is connected in series behind the pressing motor, the second speed regulating valve can be used for realizing secondary speed regulation of the pressing motor after the speed regulation is carried out by using the PVG32-1 load feedback proportional reversing valve, the speed and the pressure of the tip cutting motor and the five sugarcane supporting motors are not influenced, and the sugarcane harvesting requirement is met.

4) The load sensitive steering system which consists of the load sensitive steering gear, the priority valve and the like can preferentially distribute flow to the load sensitive steering system according to the requirement of a steering oil way, and the sufficient oil supply can be ensured no matter the load pressure is large or small, and the rotating speed of a steering wheel is high or low, so that the steering action is stable and reliable, and the steering efficiency is improved.

Drawings

Fig. 1 is a schematic structural diagram of a hydraulic system of a duplex variable plunger pump.

Fig. 2 is a schematic structural diagram of a hydraulic system of a triple gear pump.

FIG. 3 is a schematic diagram of a hydraulic system of a single-link variable displacement plunger pump.

1-1, a first single-connection electric control variable plunger pump, 1-2, a second single-connection electric control variable plunger pump, 2, a first flushing valve, 3, a second flushing valve, 4, a flow divider, 5, a cutter motor, 6, a second front channel motor, 7, a third single-connection electric control variable plunger pump, 8, a walking motor, 9-1 a first gear pump, 9-2 a second gear pump, 9-3 a third gear pump, 10, a priority valve, 11, a load sensitive steering gear, 12, an ECO80-5 quintuplet load sensitive valve group, 13, a sugarcane bin oil cylinder, 14, a header oil cylinder, 15, a tip cutting oil cylinder, 16, a sugarcane supporting oil cylinder, 17-1, a first one-way balance valve, 17-2, a second one-way balance valve, 17-3, a third one-way balance valve, 18, a one-way hydraulic lock, 19-1, a first PVG32-1 one-connection load feedback proportional reversing valve, 19-1, a second PVG32-1, a load feedback proportional reversing valve, 20, a first front channel motor, 21, a tip cutting motor, 22, a pressure down motor, 23, a sugarcane supporting motor, 24, a first rear channel motor, 25, a second rear channel motor, 26, a pressure sensor, 27, a steering oil cylinder, 28, a first speed regulating valve and 29, a second speed regulating valve.

Detailed Description

As shown in fig. 1, 2, and 3: the sugarcane harvester electrohydraulic control system comprises a duplex variable plunger pump hydraulic system, a triple gear pump hydraulic system and a single-link variable plunger pump hydraulic system, wherein a closed loop of the duplex variable plunger pump hydraulic system comprises a first single-link electrically controlled variable plunger pump 1-1, a first flushing valve 2, a flow dividing valve 4 and two cutting knife motors 5, the cutting knife of the sugarcane harvester is controlled to rotate, the two cutting knife motors 5 can be electrically controlled to regulate speed in a cab, the flow dividing valve 4 can ensure synchronous operation of the two cutting knives, and the first flushing valve 2 can open oil drainage when the pressure difference of two working oil ports of a hydraulic pump is too high, so that the hydraulic pump is protected from overheating and high pressure. Oil outlets of the two cutting knife motors 5 are connected with a working oil port B of the first single-connection electric control variable plunger pump 1-1, and an oil drainage port L2 and an oil supplementing port S on the first single-connection electric control variable plunger pump 1-1 are respectively connected with an oil inlet and an oil outlet of an oil tank.

The other closed loop consists of a second single-connection electric control variable plunger pump 1-2, a second flushing valve 3 and a second front channel motor 6, and an oil outlet of the second front channel motor 6 is connected with a working oil port B of the second single-connection electric control variable plunger pump 1-2; the second front passage motor 6 can be subjected to electric control speed regulation in the cab, and the second flushing valve 3 can be opened for oil drainage when the pressure difference of the two working ports of the hydraulic pump is too high, so that the hydraulic pump is protected from overheating and high pressure. An oil drain port L2 and an oil supplement port S on the second single-unit electrically controlled variable plunger pump 1-2 are respectively connected with an oil inlet and an oil outlet of the oil tank.

The hydraulic system of the single-connection variable plunger pump is a closed system consisting of a third single-connection electric control variable plunger pump 7 and a traveling motor 8. The working oil port A of the third single-connection electric control variable plunger pump 7 is connected with the oil inlet of the walking motor 8, and the oil outlet of the walking motor 8 is connected with the working oil port B of the third single-connection electric control variable plunger pump 7. An oil drain port L2 and an oil supplement port S on the third single-unit electrically controlled variable plunger pump 7 are respectively connected with an oil inlet and an oil outlet of the oil tank. Meanwhile, the electric control speed regulation can be carried out on the walking motor 8 in the cab, so that the advancing and retreating and the speed regulation of the sugarcane are realized.

The hydraulic system of the triple gear pump consists of three sub-circuits, wherein the first sub-circuit controls the first rear channel motor 24 and the second rear channel motor 25 by a first gear pump 9-1 and a second PVG32-1 one-connection load feedback proportional reversing valve 19-2, and a first speed regulating valve 28 is connected in parallel between the first rear channel motor 24 and the second rear channel motor 25 to form a secondary speed regulating circuit.

The second sub-loop controls the tip cutting motor 21, the pressing down motor 22, the second speed regulating valve 29 and the five sugarcane supporting motors 23 through the second gear pump 9-2 and the first PVG32-1 one-linkage load feedback proportional reversing valve 19-1, in order to ensure the pressure and speed requirements of each motor, the tip cutting motor 21 and the pressing down motor 22 are connected in parallel and then connected in series with the five sugarcane supporting motors 23, and the second speed regulating valve 29 is connected in series behind the pressing down motor 22, so that the secondary speed regulation of the pressing down motor 22 is realized, the speed and the pressure of the tip cutting motor 21 and the five sugarcane supporting motors 23 are not influenced, and the sugarcane harvesting requirements are met. The loop can obtain flow control irrelevant to load by utilizing modular control, has two flow regulation modes of electric control and manual control, and has good speed regulation characteristic.

The third sub-loop is formed by controlling a priority valve 10 and an ECO80-5 quintuplet load sensitive valve group 12 through a third gear pump 9-3, wherein the ECO80-5 quintuplet load sensitive valve group 12 respectively controls a first front channel motor 20, a sugarcane bin oil cylinder 13, a header oil cylinder 14, a tip cutting oil cylinder 15 and a sugarcane supporting oil cylinder 16, and three one-way balance valves and one-way hydraulic locks 18 can realize a balance loop of the header oil cylinder 14, the tip cutting oil cylinder 15, the sugarcane supporting oil cylinder 16 and a locking loop of the sugarcane bin oil cylinder 13. The priority valve 10 controls the load sensitive steering 11 and the steering cylinder 27.

The hydraulic system is connected with pressure sensors 26 at an A.B working oil port and an oil supplementing port of the electric control variable plunger pump and pressure ports of the first connection valve and the fifth connection valve, and simultaneously, signals are introduced into a control screen in a cab, so that various pressure values can be monitored at any time, normal operation of the system is ensured, and fault judgment is facilitated.

The cutting knife motor, the walking motor, the front channel motor, the tip cutting motor, the pressing motor, the sugarcane supporting motor and the rear channel motor are all hydraulic motors; the hydraulic motors are reasonably arranged according to the specific structure and the actual harvesting condition of the actual sugarcane harvester so as to meet the actual harvesting environment requirement.

The working principle is as follows:

the hydraulic system of the single-unit variable plunger pump is a walking speed regulation braking system of the sugarcane harvester, and consists of a third single-unit electric control variable plunger pump 7 and a walking motor 8, wherein the walking motor 8 can rotate in two directions, so that the sugarcane harvester can move forwards and backwards, and meanwhile, the speed of the walking motor 8 can be adjusted by adjusting an electric control handle of the third single-unit electric control variable plunger pump 7 in a cab, so that the movement speed of the sugarcane harvester can be adjusted. Meanwhile, an electric foot brake is arranged in the cab, so that the power supply of the third single-unit electric control variable plunger pump 7 can be cut off instantly, the emergency brake of the sugarcane harvester is realized, and the brake time can be controlled in a delayed manner.

A duplex variable plunger pump hydraulic system comprises a loop, wherein the loop comprises a first simplex electric control variable plunger pump 1-1, a first flushing valve 2, a flow divider valve 4 and two cutting knife motors 5, the cutting knife of a sugarcane machine is controlled to rotate, the flow divider valve 4 can ensure that the two cutting knives run synchronously, the first flushing valve 2 can open for oil drainage when the pressure difference of two working ports of a hydraulic pump is too high, and the hydraulic pump is protected from overheating and high pressure.

The other loop consists of a second single-connection electric control variable plunger pump 1-2, a second flushing valve 3 and a second front channel motor 6, the second front channel motor 6 can be subjected to electric control speed regulation, the second flushing valve 3 can open oil drainage when the pressure difference of two working ports of the hydraulic pump is too high, and the hydraulic pump is protected from overheating and high pressure.

A first sub-loop in the hydraulic system of the triple gear pump is a secondary speed regulating loop, a first rear channel motor 24 and a second rear channel motor 25 are controlled by a first gear pump 9-1 and a second PVG32-1 one-connection load feedback proportional reversing valve 19-2, and a first speed regulating valve 28 is connected in parallel between the first rear channel motor 24 and the second rear channel motor 25 to form the secondary speed regulating loop. When the loop is used for regulating the speed, after the speed is regulated by using the second PVG32-1 series load feedback proportional directional valve 19-2, the displacement of the first rear channel motor 24 and the displacement of the second rear channel motor 25 are different, so that the speeds are different, on the basis, if the speed of the second rear channel motor 25 needs to be further regulated, the first speed regulating valve 28 is regulated, and the second rear channel motor 25 can be regulated for the second time under the condition that the rotating speed of the first rear channel motor 24 is not changed.

The second sub-loop controls the tip cutting motor 21, the overwhelming motor 22, the speed regulating valve 28 and the five sugarcane supporting motors 23 through a second gear pump 9-2 and a first PVG32-1 combined load feedback proportional reversing valve 19-1, in order to ensure the pressure and speed requirements of each motor, the tip cutting motor 21 and the overwhelming motor 22 are connected in parallel and then connected in series with the five sugarcane supporting motors 23, and the second speed regulating valve 29 is connected in series behind the overwhelming motor 22, so that the secondary speed regulation of the overwhelming motor 22 is realized, the speed and the pressure of the tip cutting motor 21 and the five sugarcane supporting motors 23 are not influenced, and the sugarcane harvesting requirement is met. The flow control irrelevant to the load can be obtained by utilizing the modularized control, the electric control is realized through the screen control regulation in the cab, and the manual control is realized only by regulating the flow regulating screw of the working module. The loop has good speed regulation characteristic and energy-saving effect.

A third sub-loop in the hydraulic system of the triple gear pump controls a priority valve 10 and an ECO80-5 quintuplet load sensitive valve group 12 through a third gear pump 9-3, wherein the ECO80-5 quintuplet load sensitive valve group 12 respectively controls a first front channel motor 20, a sugarcane bin oil cylinder 13, a header oil cylinder 14, a tip cutting oil cylinder 15, a sugarcane supporting oil cylinder 16, a third one-way balance valve 17-3, a second one-way balance valve 17-2, a first one-way balance valve 17-1 and a one-way hydraulic lock 18 to realize a balance loop of the header oil cylinder 14, the tip cutting oil cylinder 15, the sugarcane supporting oil cylinder 16 and a locking loop of the sugarcane bin oil cylinder 13.

The priority valve 10 controls the load-sensitive steering device 11 and the steering oil cylinder 27 to form a load-sensitive steering loop, the loop can preferentially distribute flow to the load-sensitive steering device according to the requirement of a steering oil circuit by using the priority valve 10, and the sufficient oil supply can be ensured no matter the load pressure and the rotating speed of a steering wheel, so the steering action is stable and reliable. The steering load compensation circuit has good pressure compensation on the change of the steering load, the steering loop is not affected by other working loops, the main flow preferentially ensures the steering loop, and the load sensitive steering device 11 only has little flow to pass through the steering when in a middle position, so the steering load compensation circuit saves energy and is reliable in steering.

The multi-way valve adopts an ECO80-5 five-way load sensitive valve group 12, one group of the multi-way valve is used for controlling a first front channel motor 20, the first front channel motor 20 needs to carry out multiple speed regulation according to load, so an electric control mode and a manual control mode are adopted, the other four groups of the multi-way valve respectively control the sugarcane bin oil cylinder 13, the header oil cylinder 14, the tip cutting oil cylinder 15 and the sugarcane supporting oil cylinder 16, the speed of each oil cylinder does not need to be frequently regulated, in order to reduce cost, the design only adopts manual control (but keeps an electric control function), and the flow is manually regulated only by regulating a flow regulating screw on a working module of the control valve. Meanwhile, the cutting table oil cylinder 14, the tip cutting oil cylinder 15 and the sugarcane supporting oil cylinder 16 are all provided with one-way balance valves, so that the impact of the oil cylinders during movement can be eliminated, and the movement is stable and reliable. The loop of the sugarcane bin oil cylinder 13 is provided with the one-way hydraulic lock 18, so that the sugarcane bin oil cylinder 13 can be positioned when being lifted, the shaking of the sugarcane bin during sugarcane unloading is eliminated, and the working reliability is improved. In a word, the ECO80-5 five-way load sensitive valve group 12 can obtain flow control independent of load by utilizing modular control, and has good speed regulation characteristic, so that each actuating mechanism can move stably without reversing impact.

The hydraulic system of the electro-hydraulic proportional sugarcane harvester mainly utilizes a modular control technology of an electric control variable plunger pump and a load feedback proportional reversing valve, has excellent proportionality and micromobility in operation, realizes lower pressure loss irrelevant to output flow, can obtain flow control irrelevant to load, ensures that the speed of each actuating mechanism can be stably adjusted, has good speed regulation characteristic, has high system integration level, electric and manual dual control, is convenient to operate, generates less heat and has small impact, the performance of the whole machine can be effectively improved, the cooling requirement and the fuel consumption are reduced, and the effects of saving energy and reducing noise are achieved.