Electro-hydrostatic actuator system applied to excavator and control method of electro-hydrostatic actuator system

Abstract

The invention discloses an electro-hydrostatic actuator system applied to an excavator and a control method of the electro-hydrostatic actuator system. The electro-hydrostatic actuator system comprises a movable arm electro-hydrostatic actuator system, a bucket rod electro-hydrostatic actuator system and a bucket electro-hydrostatic actuator system. Each set of electro-hydrostatic actuator system comprises a driver, a servo motor, a high-pressure plunger pump, a valve block, an energy accumulator, a hydraulic cylinder, various valves and a hydraulic pipeline; the servo motor drives the high-pressure plunger pump, and the energy accumulator is used for supplementing oil and reducing system pressure fluctuation. A system formed by the three sets of electro-hydrostatic actuators has a flow dividing and converging function, can respectively drive a movable arm, a bucket rod and a bucket actuator of the excavator, and also can jointly drive the movable arm, the bucket rod and the bucket actuator. The high-pressure plunger pump can work under the four-quadrant working condition, the gravitational potential energy generated when the movable arm of the excavator works is recycled, the energy efficiency of the whole machine is improved, and balance of the dynamic characteristic and the energy efficiency ratio of the excavator is achieved.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic control, and in particular to an electrostatic hydraulic actuator system applied to an excavator and a control method thereof. Background Art

[0002] Electro-Hydrostatic Actuator (EHA) is a new type of closed hydraulic system. It is an integrated hydraulic system that highly integrates discrete components such as motors, pumps, valves, hydraulic cylinders, etc. It has the advantages of small size, high integration, high reliability, high efficiency, high power-to-weight ratio, and easy installation and maintenance.

[0003] The existing hydraulic system of the excavator is a valve-controlled open hydraulic system, which has throttling losses and generally has low efficiency. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention proposes an electrostatic hydraulic actuator system and a control method thereof applied to an excavator to improve the energy efficiency of the excavator, thereby achieving a balance between better dynamic performance and higher energy efficiency of the excavator.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] An electrostatic hydraulic actuator system applied to an excavator includes three sets of boom electrostatic hydraulic actuator system, dipper rod electrostatic hydraulic actuator system, and bucket electrostatic hydraulic actuator system; the electrostatic hydraulic actuator system applied to the excavator specifically includes: a boom hydraulic cylinder, a dipper rod hydraulic cylinder, a bucket hydraulic cylinder, a first electromagnetic switch valve, a second electromagnetic switch valve, a third electromagnetic switch valve, a fourth electromagnetic switch valve, a fifth electromagnetic switch valve, a sixth electromagnetic switch valve, a seventh electromagnetic switch valve, an eighth electromagnetic switch valve, a ninth electromagnetic switch valve, a tenth electromagnetic switch valve, an eleventh electromagnetic switch valve, a twelfth solenoid switch valve, a first hydraulically controlled one-way valve, a second hydraulically controlled one-way valve, a third hydraulically controlled one-way valve, a fourth hydraulically controlled one-way valve, a fifth hydraulically controlled one-way valve, a sixth hydraulically controlled one-way valve, a first overflow valve, a second overflow valve, a third overflow valve, a fourth overflow valve, a fifth overflow valve, a sixth overflow valve, a first accumulator, a second accumulator, a third accumulator, a first high-pressure plunger pump, a second high-pressure plunger pump, a third high-pressure plunger pump, a first servo motor, a second servo motor, a third servo motor, a first servo driver, a second servo driver, a third servo driver, an inverter and a battery;

[0007] Wherein, the first servo driver of the boom electric hydrostatic actuator system controls the movement of the first servo motor, and the first servo motor controls the rotation of the first high-pressure plunger pump; the two ends of the first high-pressure plunger pump are respectively connected with the rodless chamber and the rod chamber of the boom hydraulic cylinder through oil circuits, wherein the first electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the first high-pressure plunger pump with the rodless chamber of the boom hydraulic cylinder, and the second electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the first high-pressure plunger pump with the rod chamber of the boom hydraulic cylinder; the first high The two ends of the hydraulic plunger pump are also connected to the first accumulator through the first hydraulically controlled one-way valve, the second hydraulically controlled one-way valve, the first overflow valve, and the second overflow valve, respectively, wherein the oil inlet of the first hydraulically controlled one-way valve, the oil inlet of the second hydraulically controlled one-way valve, the oil inlet of the first overflow valve, and the oil inlet of the second overflow valve are all connected to the first accumulator, the oil outlet of the first hydraulically controlled one-way valve and the oil outlet of the first overflow valve are both connected to the rodless chamber oil circuit of the boom hydraulic cylinder, and the oil outlet of the second hydraulically controlled one-way valve and the oil outlet of the second overflow valve are both connected to the rod chamber oil circuit of the boom hydraulic cylinder;

[0008] The second servo driver of the boom electric hydrostatic actuator system controls the movement of the second servo motor, and the second servo motor controls the rotation of the second high-pressure plunger pump; the two ends of the second high-pressure plunger pump are respectively connected to the rodless chamber and the rod chamber of the boom hydraulic cylinder through oil circuits, wherein the third electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the second high-pressure plunger pump with the rodless chamber of the boom hydraulic cylinder, and the fourth electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the second high-pressure plunger pump with the rod chamber of the boom hydraulic cylinder; the second high-pressure plunger The two ends of the pump are connected to the second accumulator through the third hydraulically controlled one-way valve, the fourth hydraulically controlled one-way valve, the third overflow valve and the fourth overflow valve respectively; wherein the oil inlet of the third hydraulically controlled one-way valve, the oil inlet of the fourth hydraulically controlled one-way valve, the oil inlet of the third overflow valve and the oil inlet of the fourth overflow valve are all connected to the second accumulator, the oil outlet of the third hydraulically controlled one-way valve and the oil outlet of the third overflow valve are both connected to the rodless chamber oil circuit of the boom hydraulic cylinder, and the oil outlet of the fourth hydraulically controlled one-way valve and the oil outlet of the fourth overflow valve are both connected to the rod chamber oil circuit of the boom hydraulic cylinder;

[0009] The third servo driver of the bucket electric hydrostatic actuator system controls the movement of the third servo motor, and the third servo motor controls the rotation of the third high-pressure plunger pump; the two ends of the third high-pressure plunger pump are respectively connected with the rodless chamber and the rod chamber of the bucket hydraulic cylinder through oil circuits, wherein the fifth electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the third high-pressure plunger pump with the rodless chamber of the bucket hydraulic cylinder, and the sixth electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the third high-pressure plunger pump with the rod chamber of the bucket hydraulic cylinder; the third high-pressure plunger pump is connected with the rod chamber of the bucket hydraulic cylinder through oil circuits. The two ends of the hydraulic plunger pump are connected to the third accumulator through the fifth hydraulically controlled one-way valve, the sixth hydraulically controlled one-way valve, the fifth overflow valve and the sixth overflow valve respectively; the oil inlet of the fifth hydraulically controlled one-way valve, the oil inlet of the sixth hydraulically controlled one-way valve, the oil inlet of the fifth overflow valve and the oil inlet of the sixth overflow valve are all connected to the third accumulator, the oil outlet of the fifth hydraulically controlled one-way valve and the oil outlet of the fifth overflow valve are all connected to the rodless chamber oil circuit of the bucket hydraulic cylinder, and the oil outlet of the sixth hydraulically controlled one-way valve and the oil outlet of the sixth overflow valve are all connected to the rod chamber oil circuit of the bucket hydraulic cylinder;

[0010] The first high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rodless chamber of the boom hydraulic cylinder and the second high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rodless chamber of the boom hydraulic cylinder and is connected to the seventh electromagnetic switch valve which is electrically connected; the first high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rod chamber of the boom hydraulic cylinder and the second high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rod chamber of the boom hydraulic cylinder and is connected to the eighth electromagnetic switch valve which is electrically connected; the second high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rodless chamber of the boom hydraulic cylinder and the third high-pressure plunger pump in the bucket electric hydrostatic actuator system is connected to the oil circuit of the rodless chamber of the bucket hydraulic cylinder and is connected to the ninth electromagnetic switch valve which is electrically connected; The oil circuit of the rod chamber of the boom hydraulic cylinder connected to the second high-pressure plunger pump in the boom electro-hydraulic actuator system is connected to the oil circuit of the rod chamber of the boom hydraulic cylinder and the oil circuit of the rod chamber of the bucket hydraulic cylinder connected to the third high-pressure plunger pump in the bucket electro-hydraulic actuator system is connected to the tenth electromagnetic switch valve which is electrically connected; the oil circuit of the rodless chamber of the boom hydraulic cylinder connected to the third high-pressure plunger pump in the bucket electro-hydraulic actuator system is connected to the oil circuit of the rodless chamber of the bucket hydraulic cylinder and the eleventh electromagnetic switch valve which is electrically connected; the oil circuit of the rod chamber of the boom hydraulic cylinder connected to the first high-pressure plunger pump in the boom electro-hydraulic actuator system is connected to the oil circuit of the rod chamber of the boom hydraulic cylinder and the twelfth electromagnetic switch valve which is electrically connected;

[0011] The battery supplies power to the first servo drive, the second servo drive and the third servo drive respectively through the inverter; when the boom of the excavator descends, the gravitational potential energy of the external load feeds energy to the boom electric hydrostatic actuator system of the excavator, and the first servo motor becomes a generator at this time, converting the gravitational potential energy into electrical energy and storing it in the battery.

[0012] Furthermore, the control operation for the individual action of the boom hydraulic cylinder is as follows:

[0013] When the boom hydraulic cylinder is extended at full speed, the first electromagnetic switch valve, the second electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise;

[0014] When the boom hydraulic cylinder is retracted at full speed, the first electromagnetic switch valve, the second electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise;

[0015] The control operation for the individual action of the boom hydraulic cylinder is as follows:

[0016] When the boom hydraulic cylinder is extended at full speed, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise;

[0017] When the boom hydraulic cylinder is extended at full speed, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise;

[0018] The control operation for the individual action of the bucket hydraulic cylinder is as follows:

[0019] When the bucket hydraulic cylinder is extended at full speed, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, and the eighth electromagnetic switch valve lose power, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise;

[0020] When the bucket hydraulic cylinder is extended at full speed, the fifth solenoid switch valve, the sixth solenoid switch valve, the seventh solenoid switch valve, and the eighth solenoid switch valve lose power, and the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise.

[0021] Furthermore, the combined action control operation of the boom hydraulic cylinder and the arm hydraulic cylinder is as follows:

[0022] When the boom hydraulic cylinder and the dipper arm hydraulic cylinder are extended, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, and the eighth electromagnetic switch valve lose power, and the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise;

[0023] When the boom hydraulic cylinder extends and the dipper arm hydraulic cylinder retracts, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, and the eighth electromagnetic switch valve lose power, and the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, the first servo motor and the third servo motor rotate clockwise, and the second servo motor rotates counterclockwise;

[0024] When the boom hydraulic cylinder retracts and the arm hydraulic cylinder extends, the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the seventh solenoid switch valve, and the eighth solenoid switch valve lose power, and the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, the first servo motor and the third servo motor rotate counterclockwise, and the second servo motor rotates clockwise.

[0025] When the boom hydraulic cylinder and the dipper arm hydraulic cylinder retract, the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the seventh solenoid switch valve, and the eighth solenoid switch valve lose power, and the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise.

[0026] Furthermore, the combined action control operation of the boom hydraulic cylinder and the bucket hydraulic cylinder is as follows:

[0027] When the boom hydraulic cylinder and the bucket hydraulic cylinder are extended, the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise;

[0028] When the boom hydraulic cylinder extends and the bucket hydraulic cylinder retracts, the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, the first servo motor and the second servo motor rotate clockwise, and the third servo motor rotates counterclockwise;

[0029] When the boom hydraulic cylinder retracts and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, the first servo motor and the second servo motor rotate counterclockwise, and the third servo motor rotates clockwise;

[0030] When the boom hydraulic cylinder and the bucket hydraulic cylinder retract, the first solenoid switch valve, the second solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve lose power, and the third solenoid switch valve, the fourth solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the ninth solenoid switch valve, and the tenth solenoid switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise.

[0031] Furthermore, the combined action control operation of the boom hydraulic cylinder and the bucket hydraulic cylinder is as follows:

[0032] When the boom hydraulic cylinder and the bucket hydraulic cylinder extend, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve lose power, and the first electromagnetic switch valve, the second electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise;

[0033] When the boom hydraulic cylinder extends and the bucket hydraulic cylinder retracts, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve, and the tenth solenoid switch valve lose power, and the first solenoid switch valve, the second solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, and the first servo motor and the second servo motor rotate clockwise, and the third servo motor rotates counterclockwise.

[0034] When the boom hydraulic cylinder retracts and the bucket hydraulic cylinder extends, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve, and the tenth solenoid switch valve lose power, and the first solenoid switch valve, the second solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, and the first servo motor and the second servo motor rotate counterclockwise, and the third servo motor rotates clockwise;

[0035] When the boom hydraulic cylinder and the bucket hydraulic cylinder retract, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve and the tenth solenoid switch valve lose power, and the first solenoid switch valve, the second solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the eleventh solenoid switch valve and the twelfth solenoid switch valve gain power, and the first servo motor, the second servo motor and the third servo motor rotate counterclockwise.

[0036] Furthermore, the combined action control operation of the boom hydraulic cylinder, the dipper arm hydraulic cylinder, and the bucket hydraulic cylinder is as follows:

[0037] When the boom hydraulic cylinder extends, the dipper arm hydraulic cylinder extends, and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise;

[0038] When the boom hydraulic cylinder extends, the dipper arm hydraulic cylinder extends, and the bucket hydraulic cylinder retracts, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, the first servo motor and the second servo motor rotate clockwise, and the third servo motor rotates counterclockwise;

[0039] When the boom hydraulic cylinder extends, the dipper arm hydraulic cylinder retracts, and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the first servo motor and the third servo motor rotate clockwise, and the second servo motor rotates counterclockwise;

[0040] When the boom hydraulic cylinder extends, the dipper arm hydraulic cylinder retracts, and the bucket hydraulic cylinder retracts, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, the first servo motor rotates clockwise, and the second servo motor and the third servo motor rotate counterclockwise;

[0041] When the boom hydraulic cylinder retracts, the dipper arm hydraulic cylinder extends, and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, the first servo motor rotates counterclockwise, and the second servo motor and the third servo motor rotate clockwise;

[0042] When the boom hydraulic cylinder retracts, the arm hydraulic cylinder extends, and the bucket hydraulic cylinder retracts, the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve lose power, the first servo motor and the third servo motor rotate counterclockwise, and the second servo motor rotates clockwise.

[0043] When the boom hydraulic cylinder retracts, the dipper arm hydraulic cylinder retracts, and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, the first servo motor and the second servo motor rotate counterclockwise, and the third servo motor rotates clockwise;

[0044] When the boom hydraulic cylinder, the dipper arm hydraulic cylinder and the bucket hydraulic cylinder are retracted, the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve and the twelfth solenoid switch valve lose power, and the first servo motor, the second servo motor and the third servo motor rotate counterclockwise.

[0045] The beneficial effects of the present invention are as follows:

[0046] (1) The present invention can realize the individual and combined actions of the boom, arm, and bucket of the excavator actuator.

[0047] (2) The present invention can more accurately control the displacement of the boom, dipper arm, and bucket hydraulic cylinder, has a simple structure, a small installation volume, and is convenient and flexible.

[0048] (3) The present invention can recover the gravitational potential energy when the boom of the excavator is lowered, thereby increasing the working time of the entire excavator.

[0049] (4) The present invention can improve the energy efficiency of the excavator, better balance the energy distribution and dynamic performance of the excavator, and achieve energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Schematic diagram of an electrostatic hydraulic actuator system applied to an excavator according to an embodiment of the present invention.

[0051] In the figure: boom hydraulic cylinder 1, arm hydraulic cylinder 2, bucket hydraulic cylinder 3, first solenoid switch valve 4, second solenoid switch valve 5, third solenoid switch valve 6, fourth solenoid switch valve 7, fifth solenoid switch valve 8, sixth solenoid switch valve 9, seventh solenoid switch valve 10, eighth solenoid switch valve 11, ninth solenoid switch valve 12, tenth solenoid switch valve 13, eleventh solenoid switch valve 14, twelfth solenoid switch valve 15, first hydraulically controlled one-way valve 16, second hydraulically controlled one-way valve 17, third hydraulically controlled one-way valve 18, fourth hydraulically controlled one-way valve 19, fifth hydraulically controlled one-way valve The first hydraulic control non-return valve 20, the sixth hydraulically controlled non-return valve 21, the first overflow valve 22, the second overflow valve 23, the third overflow valve 24, the fourth overflow valve 25, the fifth overflow valve 26, the sixth overflow valve 27, the first accumulator 28, the second accumulator 29, the third accumulator 30, the first high-pressure plunger pump 31, the second high-pressure plunger pump 32, the third high-pressure plunger pump 33, the first servo motor 34, the second servo motor 35, the third servo motor 36, the first servo driver 37, the second servo driver 38, the third servo driver 39, the inverter 40, and the battery 41. DETAILED DESCRIPTION

[0052] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments, and the purpose and effects of the present invention will become more clear. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0053] like Figure 1 As shown, the electrostatic hydraulic actuator system for an excavator provided by the embodiment of the present invention includes: a boom hydraulic cylinder 1, a dipper arm hydraulic cylinder 2, a bucket hydraulic cylinder 3, a first solenoid switch valve 4, a second solenoid switch valve 5, a third solenoid switch valve 6, a fourth solenoid switch valve 7, a fifth solenoid switch valve 8, a sixth solenoid switch valve 9, a seventh solenoid switch valve 10, an eighth solenoid switch valve 11, a ninth solenoid switch valve 12, a tenth solenoid switch valve 13, an eleventh solenoid switch valve 14, a twelfth solenoid switch valve 15, a first hydraulically controlled one-way valve 16, a second hydraulically controlled one-way valve 17, a third hydraulically controlled one-way valve 18 ... Four hydraulically controlled one-way valves 19, a fifth hydraulically controlled one-way valve 20, a sixth hydraulically controlled one-way valve 21, a first overflow valve 22, a second overflow valve 23, a third overflow valve 24, a fourth overflow valve 25, a fifth overflow valve 26, a sixth overflow valve 27, a first accumulator 28, a second accumulator 29, a third accumulator 30, a first high-pressure plunger pump 31, a second high-pressure plunger pump 32, a third high-pressure plunger pump 33, a first servo motor 34, a second servo motor 35, a third servo motor 36, a first servo driver 37, a second servo driver 38, a third servo driver 39, an inverter 40, and a battery 41.

[0054] The three sets of electric hydrostatic actuator systems are respectively called the boom electric hydrostatic actuator system, the arm electric hydrostatic actuator system, and the bucket electric hydrostatic actuator system.

[0055] The first servo driver 37 of the boom electric hydrostatic actuator system controls the movement of the first servo motor 34, and the first servo motor 34 controls the rotation of the first high-pressure plunger pump 31; the two ends of the first high-pressure plunger pump 31 are connected to the rodless chamber and the rod chamber of the boom hydraulic cylinder 1 through oil circuits, wherein the first electromagnetic switch valve 4 with power-off connection is arranged on the oil circuit connecting the first high-pressure plunger pump 31 with the rodless chamber of the boom hydraulic cylinder 1, and the second electromagnetic switch valve 5 with power-off connection is arranged on the oil circuit connecting the first high-pressure plunger pump 31 with the rod chamber of the boom hydraulic cylinder 1; the two ends of the first high-pressure plunger pump 31 are also connected through the first A hydraulically controlled one-way valve 16, a second hydraulically controlled one-way valve 17, a first overflow valve 22, and a second overflow valve 23 are connected to the first accumulator 28, specifically: the oil inlet of the first hydraulically controlled one-way valve 16, the oil inlet of the second hydraulically controlled one-way valve 17, the oil inlet of the first overflow valve 22, and the oil inlet of the second overflow valve 23 are all connected to the first accumulator 28, the oil outlet of the first hydraulically controlled one-way valve 16 and the oil outlet of the first overflow valve 22 are all connected to the rodless chamber oil circuit of the boom hydraulic cylinder 1, and the oil outlet of the second hydraulically controlled one-way valve 17 and the oil outlet of the second overflow valve 23 are all connected to the rod chamber oil circuit of the boom hydraulic cylinder 1.

[0056] The second servo driver 38 of the boom electric hydrostatic actuator system controls the movement of the second servo motor 35, and the second servo motor 35 controls the rotation of the second high-pressure plunger pump 32; the two ends of the second high-pressure plunger pump 32 are connected to the rodless chamber and the rod chamber of the boom hydraulic cylinder 2 through oil circuits, wherein the oil circuit connecting the second high-pressure plunger pump 32 with the rodless chamber of the boom hydraulic cylinder 2 is provided with a third electromagnetic switch valve 6 with power failure connection, and the oil circuit connecting the second high-pressure plunger pump 32 with the rod chamber of the boom hydraulic cylinder 2 is provided with a fourth electromagnetic switch valve 7 with power failure connection; the two ends of the second high-pressure plunger pump 32 are connected to the rodless chamber and the rod chamber of the boom hydraulic cylinder 2 It is connected to the second accumulator 29 through the third hydraulically controlled one-way valve 18, the fourth hydraulically controlled one-way valve 19, the third relief valve 24 and the fourth relief valve 25; the oil inlet of the third hydraulically controlled one-way valve 18, the oil inlet of the fourth hydraulically controlled one-way valve 19, the oil inlet of the third relief valve 24 and the oil inlet of the fourth relief valve 25 are all connected to the second accumulator 29, the oil outlet of the third hydraulically controlled one-way valve 18 and the oil outlet of the third relief valve 24 are all connected to the rodless chamber oil circuit of the boom hydraulic cylinder 2, and the oil outlet of the fourth hydraulically controlled one-way valve 19 and the oil outlet of the fourth relief valve 25 are all connected to the rod chamber oil circuit of the boom hydraulic cylinder 2.

[0057] The third servo driver 39 of the bucket electric hydrostatic actuator system controls the movement of the third servo motor 36, and the third servo motor 36 controls the rotation of the third high-pressure plunger pump 33; the two ends of the third high-pressure plunger pump 33 are connected to the rodless chamber and the rod chamber of the bucket hydraulic cylinder 3 through oil circuits, wherein the oil circuit connecting the third high-pressure plunger pump 33 with the rodless chamber of the bucket hydraulic cylinder 3 is provided with a fifth electromagnetic switch valve 8 with power failure connection, and the oil circuit connecting the third high-pressure plunger pump 33 with the rod chamber of the bucket hydraulic cylinder 3 is provided with a sixth electromagnetic switch valve 9 with power failure connection; the two ends of the third high-pressure plunger pump 33 are connected to the rodless chamber of the bucket hydraulic cylinder 3 It is connected to the third accumulator 30 through the fifth hydraulically controlled one-way valve 20, the sixth hydraulically controlled one-way valve 21, the fifth overflow valve 26 and the sixth overflow valve 27; the oil inlet of the fifth hydraulically controlled one-way valve 20, the oil inlet of the sixth hydraulically controlled one-way valve 21, the oil inlet of the fifth overflow valve 26 and the oil inlet of the sixth overflow valve 27 are all connected to the third accumulator 30, the oil outlet of the fifth hydraulically controlled one-way valve 20 and the oil outlet of the fifth overflow valve 26 are all connected to the rodless chamber oil circuit of the bucket hydraulic cylinder 3, and the oil outlet of the sixth hydraulically controlled one-way valve 21 and the oil outlet of the sixth overflow valve 27 are all connected to the rod chamber oil circuit of the bucket hydraulic cylinder 3.

[0058] The first high-pressure plunger pump 31 in the boom electric hydrostatic actuator system connects the oil circuit of the rodless chamber of the boom hydraulic cylinder 1 and the second high-pressure plunger pump 32 in the boom electric hydrostatic actuator system connects the oil circuit of the rodless chamber of the boom hydraulic cylinder 2 and is connected to the seventh electromagnetic switch valve 10 which is electrically connected; the first high-pressure plunger pump 31 in the boom electric hydrostatic actuator system connects the oil circuit of the rod chamber of the boom hydraulic cylinder 1 and the second high-pressure plunger pump 32 in the boom electric hydrostatic actuator system connects the oil circuit of the rod chamber of the boom hydraulic cylinder 2 and is connected to the eighth electromagnetic switch valve 11 which is electrically connected; the second high-pressure plunger pump 32 in the boom electric hydrostatic actuator system connects the oil circuit of the rodless chamber of the boom hydraulic cylinder 2 and the third high-pressure plunger pump 33 in the bucket electric hydrostatic actuator system connects the oil circuit of the rodless chamber of the bucket hydraulic cylinder 3 and is connected to the ninth electromagnetic switch valve 12 which is electrically connected; The second high-pressure plunger pump 32 in the rod electric hydrostatic actuator system connects the oil circuit of the rod chamber of the boom hydraulic cylinder 2 and the third high-pressure plunger pump 33 in the bucket electric hydrostatic actuator system connects the oil circuit of the rod chamber of the bucket hydraulic cylinder 3 and is connected to the tenth electromagnetic switch valve 13 which is electrically connected; the first high-pressure plunger pump 31 in the boom electric hydrostatic actuator system connects the oil circuit of the rodless chamber of the boom hydraulic cylinder 1 and is connected to the eleventh electromagnetic switch valve 14 which is electrically connected in the third high-pressure plunger pump 33 in the bucket electric hydrostatic actuator system connects the oil circuit of the rodless chamber of the bucket hydraulic cylinder 3; the first high-pressure plunger pump 31 in the boom electric hydrostatic actuator system connects the oil circuit of the rod chamber of the boom hydraulic cylinder 1 and is connected to the twelfth electromagnetic switch valve 15 which is electrically connected in the third high-pressure plunger pump 33 in the bucket electric hydrostatic actuator system connects the oil circuit of the rod chamber of the bucket hydraulic cylinder 3.

[0059] The battery 41 supplies power to the first servo driver 37 , the second servo driver 38 , and the third servo driver 39 through the inverter 40 .

[0060] In the embodiment of the present invention, the energy recovery of the electric hydrostatic actuator system is specifically implemented as follows:

[0061] When it is necessary to drive the excavator boom to rise, the battery 41 supplies power to the first servo motor 34 through the inverter 40 and the first servo driver 37; when the excavator boom is lowered, the gravitational potential energy of the external load feeds energy to the excavator's boom electric hydrostatic actuator system, and the first servo motor 34 becomes a generator at this time, converting the gravitational potential energy into electrical energy and storing it in the battery 41.

[0062] In the embodiment of the present invention, the control of the electric hydrostatic actuator system is specifically implemented as follows:

[0063] For the independent motion control of boom hydraulic cylinder 1, the specific operations are as follows:

[0064] When the boom hydraulic cylinder 1 is extended at full speed, the first solenoid switch valve 4, the second solenoid switch valve 5, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 lose power, and the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 are energized, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate clockwise.

[0065] When the boom hydraulic cylinder 1 retracts at full speed, the first solenoid switch valve 4, the second solenoid switch valve 5, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 lose power, and the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 are energized, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate counterclockwise.

[0066] For the independent motion control of the boom hydraulic cylinder 2, the specific operations are as follows:

[0067] When the boom hydraulic cylinder 2 is extended at full speed, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, and the first solenoid switch valve 4, the second solenoid switch valve 5, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 are energized, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate clockwise.

[0068] When the boom hydraulic cylinder 2 is extended at full speed, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, and the first solenoid switch valve 4, the second solenoid switch valve 5, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 are energized, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate counterclockwise.

[0069] For the separate action control of bucket hydraulic cylinder 3, the specific operations are as follows:

[0070] When the bucket hydraulic cylinder 3 is extended at full speed, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, and the eighth solenoid switch valve 11 lose power, and the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 are energized, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate clockwise.

[0071] When the bucket hydraulic cylinder 3 is extended at full speed, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, and the eighth solenoid switch valve 11 lose power, and the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 are energized, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate counterclockwise.

[0072] For the joint action control of boom hydraulic cylinder 1 and arm hydraulic cylinder 2, the specific operations are as follows:

[0073] When the boom hydraulic cylinder 1 and the arm hydraulic cylinder 2 are extended, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the seventh solenoid switch valve 10, and the eighth solenoid switch valve 11 lose power, and the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 gain power, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate clockwise.

[0074] When the boom hydraulic cylinder 1 extends and the arm hydraulic cylinder 2 retracts, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the seventh solenoid switch valve 10, and the eighth solenoid switch valve 11 lose power, and the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 gain power, and the first servo motor 34 and the third servo motor 36 rotate clockwise, and the second servo motor 35 rotates counterclockwise.

[0075] When the boom hydraulic cylinder 1 retracts and the arm hydraulic cylinder 2 extends, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the seventh solenoid switch valve 10, and the eighth solenoid switch valve 11 lose power, and the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 gain power, and the first servo motor 34 and the third servo motor 36 rotate counterclockwise, and the second servo motor 35 rotates clockwise.

[0076] When the boom hydraulic cylinder 1 and the arm hydraulic cylinder 2 are retracted, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the seventh solenoid switch valve 10, and the eighth solenoid switch valve 11 lose power, and the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 gain power, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate counterclockwise.

[0077] For the joint action control of boom hydraulic cylinder 1 and bucket hydraulic cylinder 3, the specific operations are as follows:

[0078] When the boom hydraulic cylinder 1 and the bucket hydraulic cylinder 3 are extended, the first solenoid switch valve 4, the second solenoid switch valve 5, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, and the third solenoid switch valve 6, the fourth solenoid switch valve 7, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 are energized, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate clockwise.

[0079] When the boom hydraulic cylinder 1 extends and the bucket hydraulic cylinder 3 retracts, the first solenoid switch valve 4, the second solenoid switch valve 5, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, and the third solenoid switch valve 6, the fourth solenoid switch valve 7, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 gain power, and the first servo motor 34 and the second servo motor 35 rotate clockwise, and the third servo motor 36 rotates counterclockwise.

[0080] When the boom hydraulic cylinder 1 retracts and the bucket hydraulic cylinder 3 extends, the first solenoid switch valve 4, the second solenoid switch valve 5, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, and the third solenoid switch valve 6, the fourth solenoid switch valve 7, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 gain power, and the first servo motor 34 and the second servo motor 35 rotate counterclockwise, and the third servo motor 36 rotates clockwise.

[0081] When the boom hydraulic cylinder 1 and the bucket hydraulic cylinder 3 retract, the first solenoid switch valve 4, the second solenoid switch valve 5, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, and the third solenoid switch valve 6, the fourth solenoid switch valve 7, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 gain power, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate counterclockwise.

[0082] For the joint action control of the boom hydraulic cylinder 2 and the bucket hydraulic cylinder 3, the specific operations are as follows:

[0083] When the boom hydraulic cylinder 2 and the bucket hydraulic cylinder 3 are extended, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 lose power, and the first solenoid switch valve 4, the second solenoid switch valve 5, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 gain power, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate clockwise.

[0084] When the boom hydraulic cylinder 2 extends and the bucket hydraulic cylinder 3 retracts, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 lose power, and the first solenoid switch valve 4, the second solenoid switch valve 5, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 gain power, and the first servo motor 34 and the second servo motor 35 rotate clockwise, and the third servo motor 36 rotates counterclockwise.

[0085] When the boom hydraulic cylinder 2 retracts and the bucket hydraulic cylinder 3 extends, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 lose power, and the first solenoid switch valve 4, the second solenoid switch valve 5, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 gain power, and the first servo motor 34 and the second servo motor 35 rotate counterclockwise, and the third servo motor 36 rotates clockwise.

[0086] When the boom hydraulic cylinder 2 and the bucket hydraulic cylinder 3 are retracted, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the ninth solenoid switch valve 12, and the tenth solenoid switch valve 13 lose power, and the first solenoid switch valve 4, the second solenoid switch valve 5, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 gain power, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate counterclockwise.

[0087] For the joint action control of boom hydraulic cylinder 1, arm hydraulic cylinder 2, and bucket hydraulic cylinder 3, the specific operations are as follows:

[0088] When the boom hydraulic cylinder 1 extends, the arm hydraulic cylinder 2 extends, and the bucket hydraulic cylinder 3 extends, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate clockwise.

[0089] When the boom hydraulic cylinder 1 extends, the arm hydraulic cylinder 2 extends, and the bucket hydraulic cylinder 3 retracts, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, the first servo motor 34 and the second servo motor 35 rotate clockwise, and the third servo motor 36 rotates counterclockwise.

[0090] When the boom hydraulic cylinder 1 extends, the arm hydraulic cylinder 2 retracts, and the bucket hydraulic cylinder 3 extends, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, the first servo motor 34 and the third servo motor 36 rotate clockwise, and the second servo motor 35 rotates counterclockwise.

[0091] When the boom hydraulic cylinder 1 extends, the arm hydraulic cylinder 2 retracts, and the bucket hydraulic cylinder 3 retracts, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, the first servo motor 34 rotates clockwise, and the second servo motor 35 and the third servo motor 36 rotate counterclockwise.

[0092] When the boom hydraulic cylinder 1 retracts, the arm hydraulic cylinder 2 extends, and the bucket hydraulic cylinder 3 extends, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, the first servo motor 34 rotates counterclockwise, and the second servo motor 35 and the third servo motor 36 rotate clockwise.

[0093] When the boom hydraulic cylinder 1 retracts, the arm hydraulic cylinder 2 extends, and the bucket hydraulic cylinder 3 retracts, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, the first servo motor 34 and the third servo motor 36 rotate counterclockwise, and the second servo motor 35 rotates clockwise.

[0094] When the boom hydraulic cylinder 1 retracts, the arm hydraulic cylinder 2 retracts, and the bucket hydraulic cylinder 3 extends, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, the first servo motor 34 and the second servo motor 35 rotate counterclockwise, and the third servo motor 36 rotates clockwise.

[0095] When the boom hydraulic cylinder 1 retracts, the arm hydraulic cylinder 2 retracts, and the bucket hydraulic cylinder 3 retracts, the first solenoid switch valve 4, the second solenoid switch valve 5, the third solenoid switch valve 6, the fourth solenoid switch valve 7, the fifth solenoid switch valve 8, the sixth solenoid switch valve 9, the seventh solenoid switch valve 10, the eighth solenoid switch valve 11, the ninth solenoid switch valve 12, the tenth solenoid switch valve 13, the eleventh solenoid switch valve 14, and the twelfth solenoid switch valve 15 lose power, and the first servo motor 34, the second servo motor 35, and the third servo motor 36 rotate counterclockwise.

[0096] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. An electrostatic hydraulic actuator system for an excavator, characterized in that: It includes three sets of boom electric hydrostatic actuator system, dipper arm electric hydrostatic actuator system and bucket electric hydrostatic actuator system; the electric hydrostatic actuator system used in the excavator specifically includes: boom hydraulic cylinder, dipper arm hydraulic cylinder, bucket hydraulic cylinder, first solenoid switch valve, second solenoid switch valve, third solenoid switch valve, fourth solenoid switch valve, fifth solenoid switch valve, sixth solenoid switch valve, seventh solenoid switch valve, eighth solenoid switch valve, ninth solenoid switch valve, tenth solenoid switch valve, eleventh solenoid switch valve, twelfth solenoid switch valve, A first hydraulically controlled one-way valve, a second hydraulically controlled one-way valve, a third hydraulically controlled one-way valve, a fourth hydraulically controlled one-way valve, a fifth hydraulically controlled one-way valve, a sixth hydraulically controlled one-way valve, a first overflow valve, a second overflow valve, a third overflow valve, a fourth overflow valve, a fifth overflow valve, a sixth overflow valve, a first accumulator, a second accumulator, a third accumulator, a first high-pressure plunger pump, a second high-pressure plunger pump, a third high-pressure plunger pump, a first servo motor, a second servo motor, a third servo motor, a first servo drive, a second servo drive, a third servo drive, an inverter and a battery; Wherein, the first servo driver of the boom electric hydrostatic actuator system controls the movement of the first servo motor, and the first servo motor controls the rotation of the first high-pressure plunger pump; the two ends of the first high-pressure plunger pump are respectively connected with the rodless chamber and the rod chamber of the boom hydraulic cylinder through oil circuits, wherein the first electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the first high-pressure plunger pump with the rodless chamber of the boom hydraulic cylinder, and the second electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the first high-pressure plunger pump with the rod chamber of the boom hydraulic cylinder; the first high The two ends of the hydraulic plunger pump are also connected to the first accumulator through the first hydraulically controlled one-way valve, the second hydraulically controlled one-way valve, the first overflow valve, and the second overflow valve, respectively, wherein the oil inlet of the first hydraulically controlled one-way valve, the oil inlet of the second hydraulically controlled one-way valve, the oil inlet of the first overflow valve, and the oil inlet of the second overflow valve are all connected to the first accumulator, the oil outlet of the first hydraulically controlled one-way valve and the oil outlet of the first overflow valve are both connected to the rodless chamber oil circuit of the boom hydraulic cylinder, and the oil outlet of the second hydraulically controlled one-way valve and the oil outlet of the second overflow valve are both connected to the rod chamber oil circuit of the boom hydraulic cylinder; The second servo driver of the boom electric hydrostatic actuator system controls the movement of the second servo motor, and the second servo motor controls the rotation of the second high-pressure plunger pump; the two ends of the second high-pressure plunger pump are respectively connected to the rodless chamber and the rod chamber of the boom hydraulic cylinder through oil circuits, wherein the third electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the second high-pressure plunger pump with the rodless chamber of the boom hydraulic cylinder, and the fourth electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the second high-pressure plunger pump with the rod chamber of the boom hydraulic cylinder; the second high-pressure plunger The two ends of the pump are connected to the second accumulator through the third hydraulically controlled one-way valve, the fourth hydraulically controlled one-way valve, the third overflow valve and the fourth overflow valve respectively; wherein the oil inlet of the third hydraulically controlled one-way valve, the oil inlet of the fourth hydraulically controlled one-way valve, the oil inlet of the third overflow valve and the oil inlet of the fourth overflow valve are all connected to the second accumulator, the oil outlet of the third hydraulically controlled one-way valve and the oil outlet of the third overflow valve are both connected to the rodless chamber oil circuit of the boom hydraulic cylinder, and the oil outlet of the fourth hydraulically controlled one-way valve and the oil outlet of the fourth overflow valve are both connected to the rod chamber oil circuit of the boom hydraulic cylinder; The third servo driver of the bucket electric hydrostatic actuator system controls the movement of the third servo motor, and the third servo motor controls the rotation of the third high-pressure plunger pump; the two ends of the third high-pressure plunger pump are respectively connected with the rodless chamber and the rod chamber of the bucket hydraulic cylinder through oil circuits, wherein the fifth electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the third high-pressure plunger pump with the rodless chamber of the bucket hydraulic cylinder, and the sixth electromagnetic switch valve with power-off connection is arranged on the oil circuit connecting the third high-pressure plunger pump with the rod chamber of the bucket hydraulic cylinder; the third high-pressure plunger pump is connected with the rod chamber of the bucket hydraulic cylinder through oil circuits. The two ends of the hydraulic plunger pump are connected to the third accumulator through the fifth hydraulically controlled one-way valve, the sixth hydraulically controlled one-way valve, the fifth overflow valve and the sixth overflow valve respectively; the oil inlet of the fifth hydraulically controlled one-way valve, the oil inlet of the sixth hydraulically controlled one-way valve, the oil inlet of the fifth overflow valve and the oil inlet of the sixth overflow valve are all connected to the third accumulator, the oil outlet of the fifth hydraulically controlled one-way valve and the oil outlet of the fifth overflow valve are all connected to the rodless chamber oil circuit of the bucket hydraulic cylinder, and the oil outlet of the sixth hydraulically controlled one-way valve and the oil outlet of the sixth overflow valve are all connected to the rod chamber oil circuit of the bucket hydraulic cylinder; The first high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rodless chamber of the boom hydraulic cylinder and the second high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rodless chamber of the boom hydraulic cylinder and is connected to the seventh electromagnetic switch valve which is electrically connected; the first high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rod chamber of the boom hydraulic cylinder and the second high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rod chamber of the boom hydraulic cylinder and is connected to the eighth electromagnetic switch valve which is electrically connected; the second high-pressure plunger pump in the boom electric hydrostatic actuator system is connected to the oil circuit of the rodless chamber of the boom hydraulic cylinder and the third high-pressure plunger pump in the bucket electric hydrostatic actuator system is connected to the oil circuit of the rodless chamber of the bucket hydraulic cylinder and is connected to the ninth electromagnetic switch valve which is electrically connected; The oil circuit of the rod chamber of the boom hydraulic cylinder connected to the second high-pressure plunger pump in the boom electro-hydraulic actuator system is connected to the oil circuit of the rod chamber of the boom hydraulic cylinder and the oil circuit of the rod chamber of the bucket hydraulic cylinder connected to the third high-pressure plunger pump in the bucket electro-hydraulic actuator system is connected to the tenth electromagnetic switch valve which is electrically connected; the oil circuit of the rodless chamber of the boom hydraulic cylinder connected to the third high-pressure plunger pump in the bucket electro-hydraulic actuator system is connected to the oil circuit of the rodless chamber of the bucket hydraulic cylinder and the eleventh electromagnetic switch valve which is electrically connected; the oil circuit of the rod chamber of the boom hydraulic cylinder connected to the first high-pressure plunger pump in the boom electro-hydraulic actuator system is connected to the oil circuit of the rod chamber of the boom hydraulic cylinder and the twelfth electromagnetic switch valve which is electrically connected; The battery supplies power to the first servo drive, the second servo drive and the third servo drive respectively through the inverter; when the boom of the excavator descends, the gravitational potential energy of the external load feeds energy to the boom electric hydrostatic actuator system of the excavator, and the first servo motor becomes a generator at this time, converting the gravitational potential energy into electrical energy and storing it in the battery.

2. A control method for an electrostatic hydraulic actuator system applied to an excavator as claimed in claim 1, characterized in that: The control operation for the individual action of the boom hydraulic cylinder is as follows: When the boom hydraulic cylinder is extended at full speed, the first electromagnetic switch valve, the second electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise; When the boom hydraulic cylinder is retracted at full speed, the first electromagnetic switch valve, the second electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise; The control operation for the individual action of the boom hydraulic cylinder is as follows: When the boom hydraulic cylinder is extended at full speed, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise; When the boom hydraulic cylinder is extended at full speed, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise; The control operation for the individual action of the bucket hydraulic cylinder is as follows: When the bucket hydraulic cylinder is extended at full speed, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, and the eighth electromagnetic switch valve lose power, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise; When the bucket hydraulic cylinder is extended at full speed, the fifth solenoid switch valve, the sixth solenoid switch valve, the seventh solenoid switch valve, and the eighth solenoid switch valve lose power, and the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise.

3. The control method according to claim 2, characterized in that: The combined action control operation of the boom hydraulic cylinder and the dipper arm hydraulic cylinder is as follows: When the boom hydraulic cylinder and the dipper arm hydraulic cylinder are extended, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, and the eighth electromagnetic switch valve lose power, and the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise; When the boom hydraulic cylinder extends and the dipper arm hydraulic cylinder retracts, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, and the eighth electromagnetic switch valve lose power, and the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, the first servo motor and the third servo motor rotate clockwise, and the second servo motor rotates counterclockwise; When the boom hydraulic cylinder retracts and the arm hydraulic cylinder extends, the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the seventh solenoid switch valve, and the eighth solenoid switch valve lose power, and the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, the first servo motor and the third servo motor rotate counterclockwise, and the second servo motor rotates clockwise. When the boom hydraulic cylinder and the dipper arm hydraulic cylinder retract, the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the seventh solenoid switch valve, and the eighth solenoid switch valve lose power, and the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise.

4. The control method according to claim 2, characterized in that: The combined action control operation of the boom hydraulic cylinder and bucket hydraulic cylinder is as follows: When the boom hydraulic cylinder and the bucket hydraulic cylinder are extended, the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise; When the boom hydraulic cylinder extends and the bucket hydraulic cylinder retracts, the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, the first servo motor and the second servo motor rotate clockwise, and the third servo motor rotates counterclockwise; When the boom hydraulic cylinder retracts and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the third electromagnetic switch valve, the fourth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve are energized, the first servo motor and the second servo motor rotate counterclockwise, and the third servo motor rotates clockwise; When the boom hydraulic cylinder and the bucket hydraulic cylinder retract, the first solenoid switch valve, the second solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve lose power, and the third solenoid switch valve, the fourth solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the ninth solenoid switch valve, and the tenth solenoid switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate counterclockwise.

5. The control method according to claim 2, characterized in that: The combined action control operation of the boom hydraulic cylinder and bucket hydraulic cylinder is as follows: When the boom hydraulic cylinder and the bucket hydraulic cylinder extend, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the ninth electromagnetic switch valve, and the tenth electromagnetic switch valve lose power, and the first electromagnetic switch valve, the second electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve are energized, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise; When the boom hydraulic cylinder extends and the bucket hydraulic cylinder retracts, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve, and the tenth solenoid switch valve lose power, and the first solenoid switch valve, the second solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, and the first servo motor and the second servo motor rotate clockwise, and the third servo motor rotates counterclockwise. When the boom hydraulic cylinder retracts and the bucket hydraulic cylinder extends, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve, and the tenth solenoid switch valve lose power, and the first solenoid switch valve, the second solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve are energized, and the first servo motor and the second servo motor rotate counterclockwise, and the third servo motor rotates clockwise; When the boom hydraulic cylinder and the bucket hydraulic cylinder retract, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the ninth solenoid switch valve and the tenth solenoid switch valve lose power, and the first solenoid switch valve, the second solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the eleventh solenoid switch valve and the twelfth solenoid switch valve gain power, and the first servo motor, the second servo motor and the third servo motor rotate counterclockwise.

6. The control method according to claim 2, characterized in that: The combined action control operation of the boom hydraulic cylinder, the dipper arm hydraulic cylinder, and the bucket hydraulic cylinder is as follows: When the boom hydraulic cylinder extends, the dipper arm hydraulic cylinder extends, and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the first servo motor, the second servo motor, and the third servo motor rotate clockwise; When the boom hydraulic cylinder extends, the dipper arm hydraulic cylinder extends, and the bucket hydraulic cylinder retracts, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, the first servo motor and the second servo motor rotate clockwise, and the third servo motor rotates counterclockwise; When the boom hydraulic cylinder extends, the dipper arm hydraulic cylinder retracts, and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, and the first servo motor and the third servo motor rotate clockwise, and the second servo motor rotates counterclockwise; When the boom hydraulic cylinder extends, the dipper arm hydraulic cylinder retracts, and the bucket hydraulic cylinder retracts, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, the first servo motor rotates clockwise, and the second servo motor and the third servo motor rotate counterclockwise; When the boom hydraulic cylinder retracts, the dipper arm hydraulic cylinder extends, and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, the first servo motor rotates counterclockwise, and the second servo motor and the third servo motor rotate clockwise; When the boom hydraulic cylinder retracts, the arm hydraulic cylinder extends, and the bucket hydraulic cylinder retracts, the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve, and the twelfth solenoid switch valve lose power, the first servo motor and the third servo motor rotate counterclockwise, and the second servo motor rotates clockwise. When the boom hydraulic cylinder retracts, the dipper arm hydraulic cylinder retracts, and the bucket hydraulic cylinder extends, the first electromagnetic switch valve, the second electromagnetic switch valve, the third electromagnetic switch valve, the fourth electromagnetic switch valve, the fifth electromagnetic switch valve, the sixth electromagnetic switch valve, the seventh electromagnetic switch valve, the eighth electromagnetic switch valve, the ninth electromagnetic switch valve, the tenth electromagnetic switch valve, the eleventh electromagnetic switch valve, and the twelfth electromagnetic switch valve lose power, the first servo motor and the second servo motor rotate counterclockwise, and the third servo motor rotates clockwise; When the boom hydraulic cylinder, the dipper arm hydraulic cylinder and the bucket hydraulic cylinder are retracted, the first solenoid switch valve, the second solenoid switch valve, the third solenoid switch valve, the fourth solenoid switch valve, the fifth solenoid switch valve, the sixth solenoid switch valve, the seventh solenoid switch valve, the eighth solenoid switch valve, the ninth solenoid switch valve, the tenth solenoid switch valve, the eleventh solenoid switch valve and the twelfth solenoid switch valve lose power, and the first servo motor, the second servo motor and the third servo motor rotate counterclockwise.

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