CN111485590A

CN111485590A - Hydraulic control system, excavator and excavator control method

Info

Publication number: CN111485590A
Application number: CN202010466058.0A
Authority: CN
Inventors: 辛剑波; 王守伏; 尹满义
Original assignee: Sany Heavy Machinery Ltd
Current assignee: Sany Heavy Machinery Ltd
Priority date: 2020-05-28
Filing date: 2020-05-28
Publication date: 2020-08-04

Abstract

The invention provides a hydraulic control system, an excavator and an excavator control method, relates to the technical field of excavators, and aims to optimize a hydraulic control loop of the excavator to a certain extent and improve the stability of the hydraulic control system. The invention provides a hydraulic control system, which comprises an engine, a transfer case, a variable pump, a control valve, a walking power device, a rotary power device and a plurality of oil cylinders, wherein the transfer case is arranged on the engine; the variable pumps are connected with the engine through transfer cases respectively; one variable pump of the variable pumps is connected with the walking power device, one variable pump is connected with the rotation power device, the other variable pumps are connected with the oil cylinders in a one-to-one correspondence mode, and the control valves are connected with the variable pumps and used for controlling the work of each variable pump.

Description

Hydraulic control system, excavator and excavator control method

Technical Field

The invention relates to the technical field of excavators, in particular to a hydraulic control system, an excavator and an excavator control method.

Background

The work of the excavator is mainly performed by a combined operation of a traveling system, a swing system, a boom, an arm, and a bucket, and each structure of the excavator is often controlled by a hydraulic system.

Because the action has priority in the compound operation at the present stage, in order to ensure that the action of each structure in the compound operation can be realized, a throttle valve and other structures are usually adopted to carry out complicated throttling measures, so that the manufacturing cost of the excavator is increased, certain power is consumed in throttling, and the stability of a hydraulic system is reduced to a certain extent.

Therefore, it is urgently needed to provide a hydraulic control system, an excavator and an excavator control method to solve the problems in the prior art to a certain extent.

Disclosure of Invention

The invention aims to provide a hydraulic control system, an excavator and an excavator control method, so that a hydraulic control loop of the excavator is optimized to a certain extent, and the stability of the hydraulic control system is improved.

The invention provides a hydraulic control system, which comprises an engine, a transfer case, a variable pump, a control valve, a walking power device, a rotary power device and a plurality of oil cylinders, wherein the transfer case is arranged on the engine; the variable pumps are connected with the engine through the transfer case respectively; one variable pump of the variable pumps is connected with the walking power device, one variable pump is connected with the rotation power device, the other variable pumps are connected with the oil cylinders in a one-to-one correspondence mode, and the control valve is connected with the variable pumps and used for controlling the variable pumps to work.

The control valve comprises a walking control valve, a rotary control valve and a plurality of oil cylinder control valves; the rotary control valve is correspondingly communicated with the rotary power device, the walking control valve is correspondingly communicated with the walking power device, and the plurality of oil cylinders are correspondingly communicated with the plurality of oil cylinder control valves one by one.

Specifically, the oil cylinder comprises a first oil cylinder, a second oil cylinder and a third oil cylinder; the first oil cylinder, the second oil cylinder and the third oil cylinder are all connected with the oil cylinder control valve and are respectively arranged in one-to-one correspondence with the oil cylinder control valves; the first oil cylinder, the second oil cylinder and the third oil cylinder are respectively communicated with the independent variable pumps through the oil cylinder control valves.

Furthermore, a first oil path and a second oil path are communicated between the oil cylinder control valve and the oil cylinder, the first oil path is communicated with a rod chamber of the oil cylinder, and the second oil path is communicated with a rodless chamber of the oil cylinder; the first oil path and the second oil path are arranged in one-to-one correspondence with the oil cylinders.

The hydraulic control system further comprises a first oil tank and a third oil line, wherein the third oil line and the variable pumps are arranged in a one-to-one correspondence mode, the variable pumps are communicated with the first oil tank, and the first oil tank is used for supplying oil to the variable pumps.

Specifically, the hydraulic control system provided by the invention further comprises a fourth oil path, wherein the fourth oil path is arranged in one-to-one correspondence with the variable pumps and the control valves and is used for communicating the variable pumps and the control valves.

Further, the hydraulic control system provided by the invention further comprises a second oil tank and a fifth oil path, the control valve is communicated with the second oil tank through the fifth oil path, and the second oil tank is used for oil return of the control valve.

The traveling power device is a traveling hydraulic motor, and the traveling hydraulic motor is communicated with the control valve through a sixth oil path and a seventh oil path; the rotary power device is a rotary hydraulic motor, and the rotary hydraulic motor is communicated with the control valve through an eighth oil way and a ninth oil way.

Compared with the prior art, the hydraulic control system provided by the invention has the following advantages:

the invention provides a hydraulic control system, which comprises an engine, a transfer case, a variable pump, a control valve, a walking power device, a rotary power device and a plurality of oil cylinders, wherein the transfer case is arranged on the engine; the variable pumps are connected with the engine through transfer cases respectively; one variable pump of the variable pumps is connected with the walking power device, one variable pump is connected with the rotation power device, the other variable pumps are connected with the oil cylinders in a one-to-one correspondence mode, and the control valves are connected with the variable pumps and used for controlling the work of each variable pump.

From the analysis, it can be known that independent variable pumps are communicated with the walking power device, the rotation power device and the oil cylinders through control valves, so that independent hydraulic circuits are formed. When in use, each part can be independently controlled through an independent loop, so that throttling measures and unnecessary throttling power are greatly reduced.

Because the different structures are controlled by the independent hydraulic circuits, the balance of the hydraulic system is ensured without throttling measures through a multi-union valve during compound action, and the integral manufacturing cost is reduced to a certain extent.

In addition, the invention also provides an excavator, which comprises the hydraulic control system.

The invention also provides an excavator control method, which comprises the following steps: s1, acquiring excavator operation signals, wherein the operation signals comprise walking and rotating, and the actions and the maintenance of a movable arm, an arm and an excavator bucket; and S2, starting the corresponding variable pump through the transfer case according to the acquired operation action signal, and supplying oil into the corresponding control valve through the variable pump to finish the corresponding operation action.

In the technical scheme, the walking power device, the rotation power device and each oil cylinder in the hydraulic control system are communicated with the independent variable pump and the control valve, so that an independent hydraulic control loop is formed, independent control of each mechanism is realized, throttling measures can be reduced to a certain extent, throttling power is reduced, and stability of the hydraulic control system is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic overall structural diagram of a hydraulic control system according to an embodiment of the present invention;

fig. 2 is a schematic overall structural diagram of an excavator according to an embodiment of the present invention;

fig. 3 is a flowchart of an excavator control method according to an embodiment of the present invention.

In the figure: 1-an engine; 2-a variable displacement pump; 201-a third oil path; 3-a walking control valve; 301-fifth oil path; 4-a walking power device; 401-sixth oil path; 402-seventh oil passage; 5-a rotary power unit; 501-an eighth oil way; 502-ninth oil passage; 6-oil cylinder; 601-a first cylinder; 602-a second cylinder; 603-a third oil cylinder; 7-a first oil path; 8-a second oil path; 9-a first tank; 10-a second tank; 11-a fourth oil path; 12-a rotary control valve; and 13-oil cylinder control valve.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present application without making any creative effort, shall fall within the protection scope of the present application.

In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the present invention are usually placed in when used, and are only used for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements indicated must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are required to be absolutely horizontal or pendant, but rather may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the embodiments of the present application, it should also be noted that, unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As used herein, the term "and/or" includes any one of the associated listed items and any combination of any two or more of the items.

For ease of description, spatial relationship terms such as "above … …," "upper," "below … …," and "lower" may be used herein to describe one element's relationship to another element as illustrated in the figures. Such spatial relationship terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The singular forms also are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, quantities, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and/or combinations thereof.

Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, may be expected. Thus, the examples described herein are not limited to the particular shapes shown in the drawings, but include changes in shape that occur during manufacturing.

The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. Further, while the examples described herein have a variety of configurations, other configurations are possible, as will be apparent after understanding the disclosure of the present application. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present application.

Fig. 1 is a schematic diagram of an overall structure of a hydraulic control system according to an embodiment of the present invention; fig. 2 is a schematic overall structural diagram of an excavator according to an embodiment of the present invention.

As shown in fig. 1 and fig. 2, the present invention provides a hydraulic control system, which includes an engine 1, a transfer case, a variable displacement pump 2, a control valve, a traveling power device 4, a slewing power device 5, and a plurality of cylinders 6; the variable pump 2 is provided with a plurality of variable pumps 2, and the variable pumps 2 are respectively connected with the engine 1 through transfer cases; one variable pump 2 of the variable pumps 2 is connected with a walking power device 4, one variable pump 2 is connected with a rotary power device 5, the other variable pumps 2 are correspondingly connected with the oil cylinders 6 one by one, and the control valve is connected with the variable pumps 2 and used for controlling the work of each variable pump 2.

the hydraulic control system provided by the invention forms an independent hydraulic circuit by communicating the independent variable pump 2 with the walking power device 4, the rotary power device 5 and the oil cylinders 6 through control valves. When in use, each part can be independently controlled through an independent loop, so that throttling measures and unnecessary throttling power are greatly reduced.

The transfer case is used for connecting the variable pumps 2 with the engine 1, so that the variable pumps 2 are all in independent hydraulic circuits, and the problem of mutual interference is avoided.

As shown in fig. 1, the control valve includes a walking control valve 3, a rotation control valve 12, and a plurality of cylinder control valves 13; the rotary control valve 12 is correspondingly communicated with the rotary power device 5, the walking control valve 3 is correspondingly communicated with the walking power device 4, and the oil cylinders 6 are correspondingly communicated with the oil cylinder control valves 13 one by one.

The walking control valve 3 and the rotation control valve 12 comprise reversing valves and unloading valves, the excavator can be controlled to move forwards or backwards and to rotate forwards and reversely through the reversing valves, and the stability of the whole hydraulic system is guaranteed through the unloading valves.

The cylinder control valves 13 are arranged corresponding to the cylinders 6, and the cylinders 6 in the application are respectively an arm cylinder, a boom cylinder and a bucket cylinder, so that the cylinder control valves 13 corresponding to the boom and the arm in the application comprise a holding valve and a reversing valve, the boom and the arm of the excavator can be kept stable through the holding valve, and the extension and recovery of the cylinders 6 can be realized through the reversing valve. The cylinder control valve 13 corresponding to the bucket includes a change valve and an unloading valve for ensuring stability of the bucket hydraulic circuit.

When the rotary power device needs to be driven, the variable displacement pump 2 corresponding to the rotary power device 5 pumps hydraulic oil into the control valve, and the hydraulic oil enters the rotary power device 5 through the rotary control valve 12, so that the rotary power device 5 is driven. When the walking power device needs to be driven, the variable pump 2 corresponding to the walking power device 4 pumps hydraulic oil into the walking control valve 3, and the hydraulic oil enters the walking power device 4 through the walking control valve 3, so that the walking power device 4 is driven. When the oil cylinder 6 needs to be driven to stretch, the variable pump 2 corresponding to the oil cylinder 6 pumps hydraulic oil into the oil cylinder control valve 13, and the hydraulic oil enters the oil cylinder 6 through the oil cylinder control valve 13, so that the oil cylinder is driven to stretch.

It should be noted that, in the present application, the plurality of control valves may further include structures such as an overflow valve, a logic valve, a check valve, and a shut-off valve, the overflow valve ensures that the pressure of the entire hydraulic oil path is stable, the shut-off valve ensures the safety of the entire hydraulic oil path, the logic valve controls the flow rate of the excavator arm, the bucket, the boom, the swing and travel hydraulic oil paths, and the check valve prevents the hydraulic oil from flowing back.

Specifically, as shown in fig. 1 in conjunction with fig. 2, the cylinder 6 includes a first cylinder 601, a second cylinder 602, and a third cylinder 603; the first cylinder 601, the second cylinder 602, and the third cylinder 603 are connected to the cylinder control valve 13 and the variable displacement pump 2, respectively.

The first oil cylinder 601, the second oil cylinder 602 and the third oil cylinder 603 respectively correspond to a boom, a bucket and an arm of an excavator, and the first oil cylinder 601, the second oil cylinder 602 and the third oil cylinder 603 are respectively connected with the independent oil cylinder control valve 13 and the independent variable displacement pump 2, so that the operation actions of the boom, the bucket and the arm can be completely independent, and the problem of mutual interference is avoided.

It should be noted that the arrangement of the first cylinder 601, the second cylinder 602, and the third cylinder 603 shown in fig. 1 in the present application is only one of the modes for realizing the excavation work, and is also a mode that can be clearly shown graphically. Therefore, it is not limited to this arrangement that the single cylinder 6 is connected to the independent cylinder control valve 13 and the variable displacement pump 2 to form an independent hydraulic circuit.

In addition, the oil cylinder 6 in the present application includes the first oil cylinder 601, the second oil cylinder 602, and the third oil cylinder 603 only in a manner of satisfying a conventional operation mode of the excavator, and when there is another need to add the oil cylinder 6 to meet an operation requirement, the number of the oil cylinder 6, the oil cylinder control valve 13, and the variable displacement pump 2 may be automatically added in the manner described above.

Further, as shown in fig. 1 and fig. 2, a first oil path 7 and a second oil path 8 are communicated between the cylinder control valve 13 and the cylinder 6, the first oil path 7 is communicated with a rod chamber of the cylinder 6, and the second oil path 8 is communicated with a rodless chamber of the cylinder 6; the first oil passages 7 and the second oil passages 8 are arranged in one-to-one correspondence with the oil cylinders 6.

The first oil passage 7 and the second oil passage 8 can drive the cylinder 6 to extend and retract. When the first oil path 7 is used for oil inlet and the second oil path 8 is used for oil return, the oil cylinder 6 is used for recovery. When the first oil path 7 is used for returning oil and the second oil path 8 is used for feeding oil, the oil cylinder 6 is used for stretching.

Because the control valve in this application includes the switching-over valve, therefore, when the hydro-cylinder 6 in this application produces the action and changes, can realize the extension and the recovery of hydro-cylinder 6 through the switching-over valve.

As shown in fig. 1 and fig. 2, the hydraulic control system further includes a first oil tank 9 and a third oil path 201, the third oil path 201 is disposed in one-to-one correspondence with the variable pumps 2, the variable pumps 2 are all communicated with the first oil tank 9, and the first oil tank 9 is configured to supply oil to the variable pumps 2.

A plurality of variable pump 2 in this application all with be connected with first oil tank 9 through third oil circuit 201, after engine 1 starts, first oil tank 9 supplies oil to variable pump 2 through third oil circuit 201, and makes third oil circuit 201 and the setting of variable pump 2 one-to-one, also can make a plurality of variable pump 2's fuel feeding process mutual noninterference to whole hydraulic system's stability has been improved to a certain extent.

As shown in fig. 1 and fig. 2, the hydraulic control system further includes a fourth oil path 11, where the fourth oil path 11 is provided in one-to-one correspondence with the variable displacement pump 2, and is used to communicate the control valve with the variable displacement pump 2.

The traveling control valve 3, the rotation control valve 12 and the plurality of cylinder control valves 13 are all communicated with the second oil tank 10 through a fifth oil path 301, and the second oil tank 10 is used for oil return of the control valves.

Independent connection between the variable displacement pumps 2 and the control valves can be achieved through the fourth oil passage 11, oil return of the control valves can be achieved through the fifth oil passage 301, and therefore stability of the whole hydraulic circuit is improved.

Further, as shown in fig. 1 and fig. 2, the traveling power unit 4 is a traveling hydraulic motor, and the traveling hydraulic motor is communicated with the control valve through a sixth oil passage 401 and a seventh oil passage 402. The rotary power unit 5 is a rotary hydraulic motor, and the traveling hydraulic motor is communicated with the control valve through an eighth oil passage 501 and a ninth oil passage 502.

Through the sixth oil passage 401 and the seventh oil passage 402, an independent hydraulic circuit is formed between the traveling power unit 4 and the corresponding traveling control valve 3 and variable displacement pump 2; the eighth oil passage 501 and the ninth oil passage 502 form an independent hydraulic circuit between the slewing power device 5 and the corresponding slewing control valve 12 and variable displacement pump 2.

In the present application, as shown in fig. 1, the hydraulic circuits in which the traveling power unit 4 and the turning power unit 5 are located on both sides of the hydraulic circuit of the cylinder 6 only for one of the modes of achieving the excavation work, and are also clearly shown graphically. Therefore, the arrangement among the traveling power unit 4, the slewing power unit 5, and the plurality of cylinders 6 is not limited to such an arrangement, and the independent cylinder control valve 13 and the independent variable displacement pump 2 may be connected to each of the traveling power unit 4, the slewing power unit 5, and the plurality of cylinders 6 to form an independent hydraulic circuit.

In addition, as shown in fig. 1 and fig. 2, the invention also provides an excavator, which comprises the hydraulic control system.

In the working process of the excavator, the rotation and the boom are performed, and the combined actions of the arm and the bucket are very much, so that the rotation, the boom, the arm, the bucket and the walking are formed into different and independent hydraulic oil paths, and the walking hydraulic motor, the boom oil cylinder 6, the bucket oil cylinder 6, the arm oil cylinder 6 and the rotation hydraulic motor are driven by the independent variable displacement pump 2, and an independent hydraulic circuit is formed, so that the actions of the rotation, the boom, the arm, the bucket and the walking can be completely independent, thereby reducing throttling measures to a certain extent, needing no expensive multi-connected valve and further reducing unnecessary throttling power.

As shown in fig. 3, the present invention further provides an excavator control method, including the steps of: s1, acquiring excavator operation signals, wherein the operation signals comprise walking and rotating, and the actions and the maintenance of a movable arm, an arm and an excavator bucket; and S2, starting the corresponding variable pump through the transfer case according to the acquired operation action signal, and supplying oil into the corresponding control valve through the variable pump to finish the corresponding operation action.

In the application, the excavator operation action signal is sent out through a control system in the existing excavator, the control system comprises a controller for realizing instruction sending, and the controller can be a P L C or a single chip microcomputer and the like.

When the excavator needs to walk, the controller sends a walking action signal to enable the transfer case to start the variable pump 2 corresponding to the walking control valve 3, and the variable pump 2 supplies oil to the walking control valve 3, so that the walking power device 4 is driven to move, and the walking operation of the excavator is realized.

In this application, the single operation action of gyration, swing arm, dipper and scraper bowl all realizes through transfer case start-up corresponding variable pump 2, and it is no longer repeated here.

Because the excavator needs to realize the joint action of the movable arm, the arm and the bucket in the excavating operation, when the excavator needs to carry out compound operation action, the controller sends out operation action signals, the transfer case starts the corresponding variable pumps 2, the variable pumps 2 supply oil to the corresponding oil cylinder control valves 13, and the oil cylinder control valves 13 realize the action or the holding of the movable arm, the arm and the bucket according to different working conditions.

It should be noted that, since the boom, the arm, and the bucket may need to be rotated to transfer the excavation material during excavation, the transfer case can activate the variable pump 2 corresponding to the rotation power unit 5 to perform the excavation work and the function of transferring the excavation material during the excavation work.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A hydraulic control system is characterized by comprising an engine, a transfer case, a variable pump, a control valve, a walking power device, a rotary power device and a plurality of oil cylinders;

the variable pumps are connected with the engine through the transfer case respectively;

one variable pump of the variable pumps is connected with the walking power device, one variable pump is connected with the rotation power device, the other variable pumps are connected with the oil cylinders in a one-to-one correspondence mode, and the control valve is connected with the variable pumps and used for controlling the variable pumps to work.

2. The hydraulic control system of claim 1, wherein the control valves include a travel control valve, a swing control valve, and a plurality of cylinder control valves;

the rotary control valve is correspondingly communicated with the rotary power device, the walking control valve is correspondingly communicated with the walking power device, and the plurality of oil cylinders are correspondingly communicated with the plurality of oil cylinder control valves one by one.

3. The hydraulic control system of claim 2, wherein the rams comprise a first ram, a second ram, and a third ram;

the first oil cylinder, the second oil cylinder and the third oil cylinder are all connected with the oil cylinder control valve and are respectively arranged in one-to-one correspondence with the oil cylinder control valves;

the first oil cylinder, the second oil cylinder and the third oil cylinder are respectively communicated with the independent variable pumps through the oil cylinder control valves.

4. The hydraulic control system according to claim 3, wherein a first oil passage and a second oil passage are communicated between the cylinder control valve and the cylinder, the first oil passage is communicated with a rod chamber of the cylinder, and the second oil passage is communicated with a rodless chamber of the cylinder;

the first oil path and the second oil path are arranged in one-to-one correspondence with the oil cylinders.

5. The hydraulic control system according to claim 1, further comprising a first oil tank and a third oil line, wherein the third oil line and the variable pumps are arranged in a one-to-one correspondence, and the plurality of variable pumps are all communicated with the first oil tank, and the first oil tank is configured to supply oil to the variable pumps.

6. The hydraulic control system according to claim 1, further comprising fourth oil passages provided in one-to-one correspondence with the variable pumps for communicating the plurality of variable pumps with the control valves.

7. The hydraulic control system according to claim 1, further comprising a second oil tank through which the control valve communicates with the second oil tank, and a fifth oil passage for returning oil to the control valve.

8. The hydraulic control system according to any one of claims 1 to 7, wherein the traveling power unit is a traveling hydraulic motor that communicates with the control valve through a sixth oil passage and a seventh oil passage;

the rotary power device is a rotary hydraulic motor, and the rotary hydraulic motor is communicated with the control valve through an eighth oil way and a ninth oil way.

9. An excavator comprising the hydraulic control system of any one of claims 1 to 8.

10. An excavator control method is characterized by comprising the following steps:

s1, acquiring excavator operation signals, wherein the operation signals comprise walking and rotating, and the actions and the maintenance of a movable arm, an arm and an excavator bucket;

and S2, starting the corresponding variable pump through the transfer case according to the acquired operation action signal, and supplying oil into the corresponding control valve through the variable pump to finish the corresponding operation action.